forked from Minki/linux
fdaf9a5840
- Appoint myself page cache maintainer - Fix how scsicam uses the page cache - Use the memalloc_nofs_save() API to replace AOP_FLAG_NOFS - Remove the AOP flags entirely - Remove pagecache_write_begin() and pagecache_write_end() - Documentation updates - Convert several address_space operations to use folios: - is_dirty_writeback - readpage becomes read_folio - releasepage becomes release_folio - freepage becomes free_folio - Change filler_t to require a struct file pointer be the first argument like ->read_folio -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEejHryeLBw/spnjHrDpNsjXcpgj4FAmKNMDUACgkQDpNsjXcp gj4/mwf/bpHhXH4ZoNIvtUpTF6rZbqeffmc0VrbxCZDZ6igRnRPglxZ9H9v6L53O 7B0FBQIfxgNKHZpdqGdOkv8cjg/GMe/HJUbEy5wOakYPo4L9fZpHbDZ9HM2Eankj xBqLIBgBJ7doKr+Y62DAN19TVD8jfRfVtli5mqXJoNKf65J7BkxljoTH1L3EXD9d nhLAgyQjR67JQrT/39KMW+17GqLhGefLQ4YnAMONtB6TVwX/lZmigKpzVaCi4r26 bnk5vaR/3PdjtNxIoYvxdc71y2Eg05n2jEq9Wcy1AaDv/5vbyZUlZ2aBSaIVbtKX WfrhN9O3L0bU5qS7p9PoyfLc9wpq8A== =djLv -----END PGP SIGNATURE----- Merge tag 'folio-5.19' of git://git.infradead.org/users/willy/pagecache Pull page cache updates from Matthew Wilcox: - Appoint myself page cache maintainer - Fix how scsicam uses the page cache - Use the memalloc_nofs_save() API to replace AOP_FLAG_NOFS - Remove the AOP flags entirely - Remove pagecache_write_begin() and pagecache_write_end() - Documentation updates - Convert several address_space operations to use folios: - is_dirty_writeback - readpage becomes read_folio - releasepage becomes release_folio - freepage becomes free_folio - Change filler_t to require a struct file pointer be the first argument like ->read_folio * tag 'folio-5.19' of git://git.infradead.org/users/willy/pagecache: (107 commits) nilfs2: Fix some kernel-doc comments Appoint myself page cache maintainer fs: Remove aops->freepage secretmem: Convert to free_folio nfs: Convert to free_folio orangefs: Convert to free_folio fs: Add free_folio address space operation fs: Convert drop_buffers() to use a folio fs: Change try_to_free_buffers() to take a folio jbd2: Convert release_buffer_page() to use a folio jbd2: Convert jbd2_journal_try_to_free_buffers to take a folio reiserfs: Convert release_buffer_page() to use a folio fs: Remove last vestiges of releasepage ubifs: Convert to release_folio reiserfs: Convert to release_folio orangefs: Convert to release_folio ocfs2: Convert to release_folio nilfs2: Remove comment about releasepage nfs: Convert to release_folio jfs: Convert to release_folio ...
7760 lines
194 KiB
C
7760 lines
194 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2012 Alexander Block. All rights reserved.
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*/
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#include <linux/bsearch.h>
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#include <linux/fs.h>
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#include <linux/file.h>
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#include <linux/sort.h>
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#include <linux/mount.h>
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#include <linux/xattr.h>
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#include <linux/posix_acl_xattr.h>
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#include <linux/vmalloc.h>
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#include <linux/string.h>
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#include <linux/compat.h>
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#include <linux/crc32c.h>
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#include "send.h"
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#include "backref.h"
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#include "locking.h"
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#include "disk-io.h"
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#include "btrfs_inode.h"
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#include "transaction.h"
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#include "compression.h"
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#include "xattr.h"
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#include "print-tree.h"
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/*
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* Maximum number of references an extent can have in order for us to attempt to
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* issue clone operations instead of write operations. This currently exists to
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* avoid hitting limitations of the backreference walking code (taking a lot of
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* time and using too much memory for extents with large number of references).
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*/
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#define SEND_MAX_EXTENT_REFS 64
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/*
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* A fs_path is a helper to dynamically build path names with unknown size.
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* It reallocates the internal buffer on demand.
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* It allows fast adding of path elements on the right side (normal path) and
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* fast adding to the left side (reversed path). A reversed path can also be
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* unreversed if needed.
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*/
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struct fs_path {
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union {
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struct {
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char *start;
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char *end;
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char *buf;
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unsigned short buf_len:15;
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unsigned short reversed:1;
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char inline_buf[];
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};
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/*
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* Average path length does not exceed 200 bytes, we'll have
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* better packing in the slab and higher chance to satisfy
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* a allocation later during send.
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*/
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char pad[256];
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};
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};
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#define FS_PATH_INLINE_SIZE \
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(sizeof(struct fs_path) - offsetof(struct fs_path, inline_buf))
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/* reused for each extent */
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struct clone_root {
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struct btrfs_root *root;
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u64 ino;
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u64 offset;
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u64 found_refs;
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};
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#define SEND_CTX_MAX_NAME_CACHE_SIZE 128
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#define SEND_CTX_NAME_CACHE_CLEAN_SIZE (SEND_CTX_MAX_NAME_CACHE_SIZE * 2)
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struct send_ctx {
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struct file *send_filp;
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loff_t send_off;
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char *send_buf;
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u32 send_size;
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u32 send_max_size;
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u64 total_send_size;
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u64 cmd_send_size[BTRFS_SEND_C_MAX + 1];
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u64 flags; /* 'flags' member of btrfs_ioctl_send_args is u64 */
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/* Protocol version compatibility requested */
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u32 proto;
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struct btrfs_root *send_root;
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struct btrfs_root *parent_root;
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struct clone_root *clone_roots;
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int clone_roots_cnt;
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/* current state of the compare_tree call */
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struct btrfs_path *left_path;
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struct btrfs_path *right_path;
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struct btrfs_key *cmp_key;
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/*
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* Keep track of the generation of the last transaction that was used
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* for relocating a block group. This is periodically checked in order
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* to detect if a relocation happened since the last check, so that we
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* don't operate on stale extent buffers for nodes (level >= 1) or on
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* stale disk_bytenr values of file extent items.
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*/
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u64 last_reloc_trans;
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/*
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* infos of the currently processed inode. In case of deleted inodes,
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* these are the values from the deleted inode.
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*/
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u64 cur_ino;
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u64 cur_inode_gen;
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int cur_inode_new;
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int cur_inode_new_gen;
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int cur_inode_deleted;
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u64 cur_inode_size;
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u64 cur_inode_mode;
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u64 cur_inode_rdev;
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u64 cur_inode_last_extent;
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u64 cur_inode_next_write_offset;
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bool ignore_cur_inode;
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u64 send_progress;
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struct list_head new_refs;
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struct list_head deleted_refs;
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struct xarray name_cache;
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struct list_head name_cache_list;
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int name_cache_size;
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/*
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* The inode we are currently processing. It's not NULL only when we
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* need to issue write commands for data extents from this inode.
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*/
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struct inode *cur_inode;
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struct file_ra_state ra;
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u64 page_cache_clear_start;
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bool clean_page_cache;
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/*
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* We process inodes by their increasing order, so if before an
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* incremental send we reverse the parent/child relationship of
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* directories such that a directory with a lower inode number was
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* the parent of a directory with a higher inode number, and the one
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* becoming the new parent got renamed too, we can't rename/move the
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* directory with lower inode number when we finish processing it - we
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* must process the directory with higher inode number first, then
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* rename/move it and then rename/move the directory with lower inode
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* number. Example follows.
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*
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* Tree state when the first send was performed:
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*
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* .
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* |-- a (ino 257)
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* |-- b (ino 258)
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* |
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* |
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* |-- c (ino 259)
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* | |-- d (ino 260)
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* |
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* |-- c2 (ino 261)
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*
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* Tree state when the second (incremental) send is performed:
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*
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* .
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* |-- a (ino 257)
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* |-- b (ino 258)
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* |-- c2 (ino 261)
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* |-- d2 (ino 260)
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* |-- cc (ino 259)
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*
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* The sequence of steps that lead to the second state was:
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*
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* mv /a/b/c/d /a/b/c2/d2
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* mv /a/b/c /a/b/c2/d2/cc
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*
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* "c" has lower inode number, but we can't move it (2nd mv operation)
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* before we move "d", which has higher inode number.
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*
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* So we just memorize which move/rename operations must be performed
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* later when their respective parent is processed and moved/renamed.
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*/
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/* Indexed by parent directory inode number. */
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struct rb_root pending_dir_moves;
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/*
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* Reverse index, indexed by the inode number of a directory that
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* is waiting for the move/rename of its immediate parent before its
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* own move/rename can be performed.
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*/
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struct rb_root waiting_dir_moves;
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/*
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* A directory that is going to be rm'ed might have a child directory
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* which is in the pending directory moves index above. In this case,
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* the directory can only be removed after the move/rename of its child
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* is performed. Example:
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*
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* Parent snapshot:
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*
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* . (ino 256)
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* |-- a/ (ino 257)
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* |-- b/ (ino 258)
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* |-- c/ (ino 259)
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* | |-- x/ (ino 260)
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* |
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* |-- y/ (ino 261)
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*
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* Send snapshot:
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*
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* . (ino 256)
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* |-- a/ (ino 257)
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* |-- b/ (ino 258)
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* |-- YY/ (ino 261)
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* |-- x/ (ino 260)
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*
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* Sequence of steps that lead to the send snapshot:
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* rm -f /a/b/c/foo.txt
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* mv /a/b/y /a/b/YY
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* mv /a/b/c/x /a/b/YY
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* rmdir /a/b/c
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*
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* When the child is processed, its move/rename is delayed until its
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* parent is processed (as explained above), but all other operations
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* like update utimes, chown, chgrp, etc, are performed and the paths
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* that it uses for those operations must use the orphanized name of
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* its parent (the directory we're going to rm later), so we need to
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* memorize that name.
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*
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* Indexed by the inode number of the directory to be deleted.
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*/
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struct rb_root orphan_dirs;
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};
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struct pending_dir_move {
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struct rb_node node;
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struct list_head list;
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u64 parent_ino;
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u64 ino;
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u64 gen;
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struct list_head update_refs;
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};
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struct waiting_dir_move {
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struct rb_node node;
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u64 ino;
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/*
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* There might be some directory that could not be removed because it
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* was waiting for this directory inode to be moved first. Therefore
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* after this directory is moved, we can try to rmdir the ino rmdir_ino.
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*/
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u64 rmdir_ino;
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u64 rmdir_gen;
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bool orphanized;
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};
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struct orphan_dir_info {
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struct rb_node node;
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u64 ino;
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u64 gen;
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u64 last_dir_index_offset;
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};
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struct name_cache_entry {
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struct list_head list;
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/*
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* On 32bit kernels, xarray has only 32bit indices, but we need to
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* handle 64bit inums. We use the lower 32bit of the 64bit inum to store
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* it in the tree. If more than one inum would fall into the same entry,
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* we use inum_aliases to store the additional entries. inum_aliases is
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* also used to store entries with the same inum but different generations.
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*/
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struct list_head inum_aliases;
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u64 ino;
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u64 gen;
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u64 parent_ino;
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u64 parent_gen;
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int ret;
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int need_later_update;
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int name_len;
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char name[];
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};
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#define ADVANCE 1
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#define ADVANCE_ONLY_NEXT -1
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enum btrfs_compare_tree_result {
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BTRFS_COMPARE_TREE_NEW,
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BTRFS_COMPARE_TREE_DELETED,
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BTRFS_COMPARE_TREE_CHANGED,
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BTRFS_COMPARE_TREE_SAME,
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};
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__cold
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static void inconsistent_snapshot_error(struct send_ctx *sctx,
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enum btrfs_compare_tree_result result,
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const char *what)
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{
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const char *result_string;
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switch (result) {
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case BTRFS_COMPARE_TREE_NEW:
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result_string = "new";
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break;
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case BTRFS_COMPARE_TREE_DELETED:
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result_string = "deleted";
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break;
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case BTRFS_COMPARE_TREE_CHANGED:
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result_string = "updated";
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break;
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case BTRFS_COMPARE_TREE_SAME:
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ASSERT(0);
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result_string = "unchanged";
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break;
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default:
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ASSERT(0);
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result_string = "unexpected";
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}
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btrfs_err(sctx->send_root->fs_info,
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"Send: inconsistent snapshot, found %s %s for inode %llu without updated inode item, send root is %llu, parent root is %llu",
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result_string, what, sctx->cmp_key->objectid,
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sctx->send_root->root_key.objectid,
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(sctx->parent_root ?
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sctx->parent_root->root_key.objectid : 0));
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}
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__maybe_unused
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static bool proto_cmd_ok(const struct send_ctx *sctx, int cmd)
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|
{
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switch (sctx->proto) {
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case 1: return cmd < __BTRFS_SEND_C_MAX_V1;
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case 2: return cmd < __BTRFS_SEND_C_MAX_V2;
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default: return false;
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}
|
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}
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static int is_waiting_for_move(struct send_ctx *sctx, u64 ino);
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static struct waiting_dir_move *
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get_waiting_dir_move(struct send_ctx *sctx, u64 ino);
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|
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static int is_waiting_for_rm(struct send_ctx *sctx, u64 dir_ino, u64 gen);
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|
|
static int need_send_hole(struct send_ctx *sctx)
|
|
{
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|
return (sctx->parent_root && !sctx->cur_inode_new &&
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!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted &&
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S_ISREG(sctx->cur_inode_mode));
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}
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|
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static void fs_path_reset(struct fs_path *p)
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{
|
|
if (p->reversed) {
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p->start = p->buf + p->buf_len - 1;
|
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p->end = p->start;
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*p->start = 0;
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} else {
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p->start = p->buf;
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p->end = p->start;
|
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*p->start = 0;
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}
|
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}
|
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|
|
static struct fs_path *fs_path_alloc(void)
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|
{
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|
struct fs_path *p;
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|
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p = kmalloc(sizeof(*p), GFP_KERNEL);
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if (!p)
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return NULL;
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p->reversed = 0;
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p->buf = p->inline_buf;
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p->buf_len = FS_PATH_INLINE_SIZE;
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fs_path_reset(p);
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return p;
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}
|
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|
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static struct fs_path *fs_path_alloc_reversed(void)
|
|
{
|
|
struct fs_path *p;
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|
|
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p = fs_path_alloc();
|
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if (!p)
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return NULL;
|
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p->reversed = 1;
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fs_path_reset(p);
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return p;
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}
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|
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static void fs_path_free(struct fs_path *p)
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{
|
|
if (!p)
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return;
|
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if (p->buf != p->inline_buf)
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kfree(p->buf);
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kfree(p);
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}
|
|
|
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static int fs_path_len(struct fs_path *p)
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|
{
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|
return p->end - p->start;
|
|
}
|
|
|
|
static int fs_path_ensure_buf(struct fs_path *p, int len)
|
|
{
|
|
char *tmp_buf;
|
|
int path_len;
|
|
int old_buf_len;
|
|
|
|
len++;
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|
|
if (p->buf_len >= len)
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return 0;
|
|
|
|
if (len > PATH_MAX) {
|
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WARN_ON(1);
|
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return -ENOMEM;
|
|
}
|
|
|
|
path_len = p->end - p->start;
|
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old_buf_len = p->buf_len;
|
|
|
|
/*
|
|
* First time the inline_buf does not suffice
|
|
*/
|
|
if (p->buf == p->inline_buf) {
|
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tmp_buf = kmalloc(len, GFP_KERNEL);
|
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if (tmp_buf)
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memcpy(tmp_buf, p->buf, old_buf_len);
|
|
} else {
|
|
tmp_buf = krealloc(p->buf, len, GFP_KERNEL);
|
|
}
|
|
if (!tmp_buf)
|
|
return -ENOMEM;
|
|
p->buf = tmp_buf;
|
|
/*
|
|
* The real size of the buffer is bigger, this will let the fast path
|
|
* happen most of the time
|
|
*/
|
|
p->buf_len = ksize(p->buf);
|
|
|
|
if (p->reversed) {
|
|
tmp_buf = p->buf + old_buf_len - path_len - 1;
|
|
p->end = p->buf + p->buf_len - 1;
|
|
p->start = p->end - path_len;
|
|
memmove(p->start, tmp_buf, path_len + 1);
|
|
} else {
|
|
p->start = p->buf;
|
|
p->end = p->start + path_len;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int fs_path_prepare_for_add(struct fs_path *p, int name_len,
|
|
char **prepared)
|
|
{
|
|
int ret;
|
|
int new_len;
|
|
|
|
new_len = p->end - p->start + name_len;
|
|
if (p->start != p->end)
|
|
new_len++;
|
|
ret = fs_path_ensure_buf(p, new_len);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
if (p->reversed) {
|
|
if (p->start != p->end)
|
|
*--p->start = '/';
|
|
p->start -= name_len;
|
|
*prepared = p->start;
|
|
} else {
|
|
if (p->start != p->end)
|
|
*p->end++ = '/';
|
|
*prepared = p->end;
|
|
p->end += name_len;
|
|
*p->end = 0;
|
|
}
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int fs_path_add(struct fs_path *p, const char *name, int name_len)
|
|
{
|
|
int ret;
|
|
char *prepared;
|
|
|
|
ret = fs_path_prepare_for_add(p, name_len, &prepared);
|
|
if (ret < 0)
|
|
goto out;
|
|
memcpy(prepared, name, name_len);
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int fs_path_add_path(struct fs_path *p, struct fs_path *p2)
|
|
{
|
|
int ret;
|
|
char *prepared;
|
|
|
|
ret = fs_path_prepare_for_add(p, p2->end - p2->start, &prepared);
|
|
if (ret < 0)
|
|
goto out;
|
|
memcpy(prepared, p2->start, p2->end - p2->start);
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int fs_path_add_from_extent_buffer(struct fs_path *p,
|
|
struct extent_buffer *eb,
|
|
unsigned long off, int len)
|
|
{
|
|
int ret;
|
|
char *prepared;
|
|
|
|
ret = fs_path_prepare_for_add(p, len, &prepared);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
read_extent_buffer(eb, prepared, off, len);
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int fs_path_copy(struct fs_path *p, struct fs_path *from)
|
|
{
|
|
p->reversed = from->reversed;
|
|
fs_path_reset(p);
|
|
|
|
return fs_path_add_path(p, from);
|
|
}
|
|
|
|
static void fs_path_unreverse(struct fs_path *p)
|
|
{
|
|
char *tmp;
|
|
int len;
|
|
|
|
if (!p->reversed)
|
|
return;
|
|
|
|
tmp = p->start;
|
|
len = p->end - p->start;
|
|
p->start = p->buf;
|
|
p->end = p->start + len;
|
|
memmove(p->start, tmp, len + 1);
|
|
p->reversed = 0;
|
|
}
|
|
|
|
static struct btrfs_path *alloc_path_for_send(void)
|
|
{
|
|
struct btrfs_path *path;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path)
|
|
return NULL;
|
|
path->search_commit_root = 1;
|
|
path->skip_locking = 1;
|
|
path->need_commit_sem = 1;
|
|
return path;
|
|
}
|
|
|
|
static int write_buf(struct file *filp, const void *buf, u32 len, loff_t *off)
|
|
{
|
|
int ret;
|
|
u32 pos = 0;
|
|
|
|
while (pos < len) {
|
|
ret = kernel_write(filp, buf + pos, len - pos, off);
|
|
/* TODO handle that correctly */
|
|
/*if (ret == -ERESTARTSYS) {
|
|
continue;
|
|
}*/
|
|
if (ret < 0)
|
|
return ret;
|
|
if (ret == 0) {
|
|
return -EIO;
|
|
}
|
|
pos += ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int tlv_put(struct send_ctx *sctx, u16 attr, const void *data, int len)
|
|
{
|
|
struct btrfs_tlv_header *hdr;
|
|
int total_len = sizeof(*hdr) + len;
|
|
int left = sctx->send_max_size - sctx->send_size;
|
|
|
|
if (unlikely(left < total_len))
|
|
return -EOVERFLOW;
|
|
|
|
hdr = (struct btrfs_tlv_header *) (sctx->send_buf + sctx->send_size);
|
|
put_unaligned_le16(attr, &hdr->tlv_type);
|
|
put_unaligned_le16(len, &hdr->tlv_len);
|
|
memcpy(hdr + 1, data, len);
|
|
sctx->send_size += total_len;
|
|
|
|
return 0;
|
|
}
|
|
|
|
#define TLV_PUT_DEFINE_INT(bits) \
|
|
static int tlv_put_u##bits(struct send_ctx *sctx, \
|
|
u##bits attr, u##bits value) \
|
|
{ \
|
|
__le##bits __tmp = cpu_to_le##bits(value); \
|
|
return tlv_put(sctx, attr, &__tmp, sizeof(__tmp)); \
|
|
}
|
|
|
|
TLV_PUT_DEFINE_INT(64)
|
|
|
|
static int tlv_put_string(struct send_ctx *sctx, u16 attr,
|
|
const char *str, int len)
|
|
{
|
|
if (len == -1)
|
|
len = strlen(str);
|
|
return tlv_put(sctx, attr, str, len);
|
|
}
|
|
|
|
static int tlv_put_uuid(struct send_ctx *sctx, u16 attr,
|
|
const u8 *uuid)
|
|
{
|
|
return tlv_put(sctx, attr, uuid, BTRFS_UUID_SIZE);
|
|
}
|
|
|
|
static int tlv_put_btrfs_timespec(struct send_ctx *sctx, u16 attr,
|
|
struct extent_buffer *eb,
|
|
struct btrfs_timespec *ts)
|
|
{
|
|
struct btrfs_timespec bts;
|
|
read_extent_buffer(eb, &bts, (unsigned long)ts, sizeof(bts));
|
|
return tlv_put(sctx, attr, &bts, sizeof(bts));
|
|
}
|
|
|
|
|
|
#define TLV_PUT(sctx, attrtype, data, attrlen) \
|
|
do { \
|
|
ret = tlv_put(sctx, attrtype, data, attrlen); \
|
|
if (ret < 0) \
|
|
goto tlv_put_failure; \
|
|
} while (0)
|
|
|
|
#define TLV_PUT_INT(sctx, attrtype, bits, value) \
|
|
do { \
|
|
ret = tlv_put_u##bits(sctx, attrtype, value); \
|
|
if (ret < 0) \
|
|
goto tlv_put_failure; \
|
|
} while (0)
|
|
|
|
#define TLV_PUT_U8(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 8, data)
|
|
#define TLV_PUT_U16(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 16, data)
|
|
#define TLV_PUT_U32(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 32, data)
|
|
#define TLV_PUT_U64(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 64, data)
|
|
#define TLV_PUT_STRING(sctx, attrtype, str, len) \
|
|
do { \
|
|
ret = tlv_put_string(sctx, attrtype, str, len); \
|
|
if (ret < 0) \
|
|
goto tlv_put_failure; \
|
|
} while (0)
|
|
#define TLV_PUT_PATH(sctx, attrtype, p) \
|
|
do { \
|
|
ret = tlv_put_string(sctx, attrtype, p->start, \
|
|
p->end - p->start); \
|
|
if (ret < 0) \
|
|
goto tlv_put_failure; \
|
|
} while(0)
|
|
#define TLV_PUT_UUID(sctx, attrtype, uuid) \
|
|
do { \
|
|
ret = tlv_put_uuid(sctx, attrtype, uuid); \
|
|
if (ret < 0) \
|
|
goto tlv_put_failure; \
|
|
} while (0)
|
|
#define TLV_PUT_BTRFS_TIMESPEC(sctx, attrtype, eb, ts) \
|
|
do { \
|
|
ret = tlv_put_btrfs_timespec(sctx, attrtype, eb, ts); \
|
|
if (ret < 0) \
|
|
goto tlv_put_failure; \
|
|
} while (0)
|
|
|
|
static int send_header(struct send_ctx *sctx)
|
|
{
|
|
struct btrfs_stream_header hdr;
|
|
|
|
strcpy(hdr.magic, BTRFS_SEND_STREAM_MAGIC);
|
|
hdr.version = cpu_to_le32(BTRFS_SEND_STREAM_VERSION);
|
|
|
|
return write_buf(sctx->send_filp, &hdr, sizeof(hdr),
|
|
&sctx->send_off);
|
|
}
|
|
|
|
/*
|
|
* For each command/item we want to send to userspace, we call this function.
|
|
*/
|
|
static int begin_cmd(struct send_ctx *sctx, int cmd)
|
|
{
|
|
struct btrfs_cmd_header *hdr;
|
|
|
|
if (WARN_ON(!sctx->send_buf))
|
|
return -EINVAL;
|
|
|
|
BUG_ON(sctx->send_size);
|
|
|
|
sctx->send_size += sizeof(*hdr);
|
|
hdr = (struct btrfs_cmd_header *)sctx->send_buf;
|
|
put_unaligned_le16(cmd, &hdr->cmd);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int send_cmd(struct send_ctx *sctx)
|
|
{
|
|
int ret;
|
|
struct btrfs_cmd_header *hdr;
|
|
u32 crc;
|
|
|
|
hdr = (struct btrfs_cmd_header *)sctx->send_buf;
|
|
put_unaligned_le32(sctx->send_size - sizeof(*hdr), &hdr->len);
|
|
put_unaligned_le32(0, &hdr->crc);
|
|
|
|
crc = btrfs_crc32c(0, (unsigned char *)sctx->send_buf, sctx->send_size);
|
|
put_unaligned_le32(crc, &hdr->crc);
|
|
|
|
ret = write_buf(sctx->send_filp, sctx->send_buf, sctx->send_size,
|
|
&sctx->send_off);
|
|
|
|
sctx->total_send_size += sctx->send_size;
|
|
sctx->cmd_send_size[get_unaligned_le16(&hdr->cmd)] += sctx->send_size;
|
|
sctx->send_size = 0;
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Sends a move instruction to user space
|
|
*/
|
|
static int send_rename(struct send_ctx *sctx,
|
|
struct fs_path *from, struct fs_path *to)
|
|
{
|
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
|
|
int ret;
|
|
|
|
btrfs_debug(fs_info, "send_rename %s -> %s", from->start, to->start);
|
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_RENAME);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, from);
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_TO, to);
|
|
|
|
ret = send_cmd(sctx);
|
|
|
|
tlv_put_failure:
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Sends a link instruction to user space
|
|
*/
|
|
static int send_link(struct send_ctx *sctx,
|
|
struct fs_path *path, struct fs_path *lnk)
|
|
{
|
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
|
|
int ret;
|
|
|
|
btrfs_debug(fs_info, "send_link %s -> %s", path->start, lnk->start);
|
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_LINK);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, lnk);
|
|
|
|
ret = send_cmd(sctx);
|
|
|
|
tlv_put_failure:
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Sends an unlink instruction to user space
|
|
*/
|
|
static int send_unlink(struct send_ctx *sctx, struct fs_path *path)
|
|
{
|
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
|
|
int ret;
|
|
|
|
btrfs_debug(fs_info, "send_unlink %s", path->start);
|
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_UNLINK);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
|
|
|
|
ret = send_cmd(sctx);
|
|
|
|
tlv_put_failure:
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Sends a rmdir instruction to user space
|
|
*/
|
|
static int send_rmdir(struct send_ctx *sctx, struct fs_path *path)
|
|
{
|
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
|
|
int ret;
|
|
|
|
btrfs_debug(fs_info, "send_rmdir %s", path->start);
|
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_RMDIR);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
|
|
|
|
ret = send_cmd(sctx);
|
|
|
|
tlv_put_failure:
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Helper function to retrieve some fields from an inode item.
|
|
*/
|
|
static int __get_inode_info(struct btrfs_root *root, struct btrfs_path *path,
|
|
u64 ino, u64 *size, u64 *gen, u64 *mode, u64 *uid,
|
|
u64 *gid, u64 *rdev)
|
|
{
|
|
int ret;
|
|
struct btrfs_inode_item *ii;
|
|
struct btrfs_key key;
|
|
|
|
key.objectid = ino;
|
|
key.type = BTRFS_INODE_ITEM_KEY;
|
|
key.offset = 0;
|
|
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
|
|
if (ret) {
|
|
if (ret > 0)
|
|
ret = -ENOENT;
|
|
return ret;
|
|
}
|
|
|
|
ii = btrfs_item_ptr(path->nodes[0], path->slots[0],
|
|
struct btrfs_inode_item);
|
|
if (size)
|
|
*size = btrfs_inode_size(path->nodes[0], ii);
|
|
if (gen)
|
|
*gen = btrfs_inode_generation(path->nodes[0], ii);
|
|
if (mode)
|
|
*mode = btrfs_inode_mode(path->nodes[0], ii);
|
|
if (uid)
|
|
*uid = btrfs_inode_uid(path->nodes[0], ii);
|
|
if (gid)
|
|
*gid = btrfs_inode_gid(path->nodes[0], ii);
|
|
if (rdev)
|
|
*rdev = btrfs_inode_rdev(path->nodes[0], ii);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int get_inode_info(struct btrfs_root *root,
|
|
u64 ino, u64 *size, u64 *gen,
|
|
u64 *mode, u64 *uid, u64 *gid,
|
|
u64 *rdev)
|
|
{
|
|
struct btrfs_path *path;
|
|
int ret;
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
ret = __get_inode_info(root, path, ino, size, gen, mode, uid, gid,
|
|
rdev);
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
typedef int (*iterate_inode_ref_t)(int num, u64 dir, int index,
|
|
struct fs_path *p,
|
|
void *ctx);
|
|
|
|
/*
|
|
* Helper function to iterate the entries in ONE btrfs_inode_ref or
|
|
* btrfs_inode_extref.
|
|
* The iterate callback may return a non zero value to stop iteration. This can
|
|
* be a negative value for error codes or 1 to simply stop it.
|
|
*
|
|
* path must point to the INODE_REF or INODE_EXTREF when called.
|
|
*/
|
|
static int iterate_inode_ref(struct btrfs_root *root, struct btrfs_path *path,
|
|
struct btrfs_key *found_key, int resolve,
|
|
iterate_inode_ref_t iterate, void *ctx)
|
|
{
|
|
struct extent_buffer *eb = path->nodes[0];
|
|
struct btrfs_inode_ref *iref;
|
|
struct btrfs_inode_extref *extref;
|
|
struct btrfs_path *tmp_path;
|
|
struct fs_path *p;
|
|
u32 cur = 0;
|
|
u32 total;
|
|
int slot = path->slots[0];
|
|
u32 name_len;
|
|
char *start;
|
|
int ret = 0;
|
|
int num = 0;
|
|
int index;
|
|
u64 dir;
|
|
unsigned long name_off;
|
|
unsigned long elem_size;
|
|
unsigned long ptr;
|
|
|
|
p = fs_path_alloc_reversed();
|
|
if (!p)
|
|
return -ENOMEM;
|
|
|
|
tmp_path = alloc_path_for_send();
|
|
if (!tmp_path) {
|
|
fs_path_free(p);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
|
|
if (found_key->type == BTRFS_INODE_REF_KEY) {
|
|
ptr = (unsigned long)btrfs_item_ptr(eb, slot,
|
|
struct btrfs_inode_ref);
|
|
total = btrfs_item_size(eb, slot);
|
|
elem_size = sizeof(*iref);
|
|
} else {
|
|
ptr = btrfs_item_ptr_offset(eb, slot);
|
|
total = btrfs_item_size(eb, slot);
|
|
elem_size = sizeof(*extref);
|
|
}
|
|
|
|
while (cur < total) {
|
|
fs_path_reset(p);
|
|
|
|
if (found_key->type == BTRFS_INODE_REF_KEY) {
|
|
iref = (struct btrfs_inode_ref *)(ptr + cur);
|
|
name_len = btrfs_inode_ref_name_len(eb, iref);
|
|
name_off = (unsigned long)(iref + 1);
|
|
index = btrfs_inode_ref_index(eb, iref);
|
|
dir = found_key->offset;
|
|
} else {
|
|
extref = (struct btrfs_inode_extref *)(ptr + cur);
|
|
name_len = btrfs_inode_extref_name_len(eb, extref);
|
|
name_off = (unsigned long)&extref->name;
|
|
index = btrfs_inode_extref_index(eb, extref);
|
|
dir = btrfs_inode_extref_parent(eb, extref);
|
|
}
|
|
|
|
if (resolve) {
|
|
start = btrfs_ref_to_path(root, tmp_path, name_len,
|
|
name_off, eb, dir,
|
|
p->buf, p->buf_len);
|
|
if (IS_ERR(start)) {
|
|
ret = PTR_ERR(start);
|
|
goto out;
|
|
}
|
|
if (start < p->buf) {
|
|
/* overflow , try again with larger buffer */
|
|
ret = fs_path_ensure_buf(p,
|
|
p->buf_len + p->buf - start);
|
|
if (ret < 0)
|
|
goto out;
|
|
start = btrfs_ref_to_path(root, tmp_path,
|
|
name_len, name_off,
|
|
eb, dir,
|
|
p->buf, p->buf_len);
|
|
if (IS_ERR(start)) {
|
|
ret = PTR_ERR(start);
|
|
goto out;
|
|
}
|
|
BUG_ON(start < p->buf);
|
|
}
|
|
p->start = start;
|
|
} else {
|
|
ret = fs_path_add_from_extent_buffer(p, eb, name_off,
|
|
name_len);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
|
|
cur += elem_size + name_len;
|
|
ret = iterate(num, dir, index, p, ctx);
|
|
if (ret)
|
|
goto out;
|
|
num++;
|
|
}
|
|
|
|
out:
|
|
btrfs_free_path(tmp_path);
|
|
fs_path_free(p);
|
|
return ret;
|
|
}
|
|
|
|
typedef int (*iterate_dir_item_t)(int num, struct btrfs_key *di_key,
|
|
const char *name, int name_len,
|
|
const char *data, int data_len,
|
|
void *ctx);
|
|
|
|
/*
|
|
* Helper function to iterate the entries in ONE btrfs_dir_item.
|
|
* The iterate callback may return a non zero value to stop iteration. This can
|
|
* be a negative value for error codes or 1 to simply stop it.
|
|
*
|
|
* path must point to the dir item when called.
|
|
*/
|
|
static int iterate_dir_item(struct btrfs_root *root, struct btrfs_path *path,
|
|
iterate_dir_item_t iterate, void *ctx)
|
|
{
|
|
int ret = 0;
|
|
struct extent_buffer *eb;
|
|
struct btrfs_dir_item *di;
|
|
struct btrfs_key di_key;
|
|
char *buf = NULL;
|
|
int buf_len;
|
|
u32 name_len;
|
|
u32 data_len;
|
|
u32 cur;
|
|
u32 len;
|
|
u32 total;
|
|
int slot;
|
|
int num;
|
|
|
|
/*
|
|
* Start with a small buffer (1 page). If later we end up needing more
|
|
* space, which can happen for xattrs on a fs with a leaf size greater
|
|
* then the page size, attempt to increase the buffer. Typically xattr
|
|
* values are small.
|
|
*/
|
|
buf_len = PATH_MAX;
|
|
buf = kmalloc(buf_len, GFP_KERNEL);
|
|
if (!buf) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
eb = path->nodes[0];
|
|
slot = path->slots[0];
|
|
di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
|
|
cur = 0;
|
|
len = 0;
|
|
total = btrfs_item_size(eb, slot);
|
|
|
|
num = 0;
|
|
while (cur < total) {
|
|
name_len = btrfs_dir_name_len(eb, di);
|
|
data_len = btrfs_dir_data_len(eb, di);
|
|
btrfs_dir_item_key_to_cpu(eb, di, &di_key);
|
|
|
|
if (btrfs_dir_type(eb, di) == BTRFS_FT_XATTR) {
|
|
if (name_len > XATTR_NAME_MAX) {
|
|
ret = -ENAMETOOLONG;
|
|
goto out;
|
|
}
|
|
if (name_len + data_len >
|
|
BTRFS_MAX_XATTR_SIZE(root->fs_info)) {
|
|
ret = -E2BIG;
|
|
goto out;
|
|
}
|
|
} else {
|
|
/*
|
|
* Path too long
|
|
*/
|
|
if (name_len + data_len > PATH_MAX) {
|
|
ret = -ENAMETOOLONG;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (name_len + data_len > buf_len) {
|
|
buf_len = name_len + data_len;
|
|
if (is_vmalloc_addr(buf)) {
|
|
vfree(buf);
|
|
buf = NULL;
|
|
} else {
|
|
char *tmp = krealloc(buf, buf_len,
|
|
GFP_KERNEL | __GFP_NOWARN);
|
|
|
|
if (!tmp)
|
|
kfree(buf);
|
|
buf = tmp;
|
|
}
|
|
if (!buf) {
|
|
buf = kvmalloc(buf_len, GFP_KERNEL);
|
|
if (!buf) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
}
|
|
}
|
|
|
|
read_extent_buffer(eb, buf, (unsigned long)(di + 1),
|
|
name_len + data_len);
|
|
|
|
len = sizeof(*di) + name_len + data_len;
|
|
di = (struct btrfs_dir_item *)((char *)di + len);
|
|
cur += len;
|
|
|
|
ret = iterate(num, &di_key, buf, name_len, buf + name_len,
|
|
data_len, ctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
num++;
|
|
}
|
|
|
|
out:
|
|
kvfree(buf);
|
|
return ret;
|
|
}
|
|
|
|
static int __copy_first_ref(int num, u64 dir, int index,
|
|
struct fs_path *p, void *ctx)
|
|
{
|
|
int ret;
|
|
struct fs_path *pt = ctx;
|
|
|
|
ret = fs_path_copy(pt, p);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
/* we want the first only */
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Retrieve the first path of an inode. If an inode has more then one
|
|
* ref/hardlink, this is ignored.
|
|
*/
|
|
static int get_inode_path(struct btrfs_root *root,
|
|
u64 ino, struct fs_path *path)
|
|
{
|
|
int ret;
|
|
struct btrfs_key key, found_key;
|
|
struct btrfs_path *p;
|
|
|
|
p = alloc_path_for_send();
|
|
if (!p)
|
|
return -ENOMEM;
|
|
|
|
fs_path_reset(path);
|
|
|
|
key.objectid = ino;
|
|
key.type = BTRFS_INODE_REF_KEY;
|
|
key.offset = 0;
|
|
|
|
ret = btrfs_search_slot_for_read(root, &key, p, 1, 0);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret) {
|
|
ret = 1;
|
|
goto out;
|
|
}
|
|
btrfs_item_key_to_cpu(p->nodes[0], &found_key, p->slots[0]);
|
|
if (found_key.objectid != ino ||
|
|
(found_key.type != BTRFS_INODE_REF_KEY &&
|
|
found_key.type != BTRFS_INODE_EXTREF_KEY)) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
|
|
ret = iterate_inode_ref(root, p, &found_key, 1,
|
|
__copy_first_ref, path);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = 0;
|
|
|
|
out:
|
|
btrfs_free_path(p);
|
|
return ret;
|
|
}
|
|
|
|
struct backref_ctx {
|
|
struct send_ctx *sctx;
|
|
|
|
/* number of total found references */
|
|
u64 found;
|
|
|
|
/*
|
|
* used for clones found in send_root. clones found behind cur_objectid
|
|
* and cur_offset are not considered as allowed clones.
|
|
*/
|
|
u64 cur_objectid;
|
|
u64 cur_offset;
|
|
|
|
/* may be truncated in case it's the last extent in a file */
|
|
u64 extent_len;
|
|
|
|
/* Just to check for bugs in backref resolving */
|
|
int found_itself;
|
|
};
|
|
|
|
static int __clone_root_cmp_bsearch(const void *key, const void *elt)
|
|
{
|
|
u64 root = (u64)(uintptr_t)key;
|
|
const struct clone_root *cr = elt;
|
|
|
|
if (root < cr->root->root_key.objectid)
|
|
return -1;
|
|
if (root > cr->root->root_key.objectid)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static int __clone_root_cmp_sort(const void *e1, const void *e2)
|
|
{
|
|
const struct clone_root *cr1 = e1;
|
|
const struct clone_root *cr2 = e2;
|
|
|
|
if (cr1->root->root_key.objectid < cr2->root->root_key.objectid)
|
|
return -1;
|
|
if (cr1->root->root_key.objectid > cr2->root->root_key.objectid)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Called for every backref that is found for the current extent.
|
|
* Results are collected in sctx->clone_roots->ino/offset/found_refs
|
|
*/
|
|
static int __iterate_backrefs(u64 ino, u64 offset, u64 root, void *ctx_)
|
|
{
|
|
struct backref_ctx *bctx = ctx_;
|
|
struct clone_root *found;
|
|
|
|
/* First check if the root is in the list of accepted clone sources */
|
|
found = bsearch((void *)(uintptr_t)root, bctx->sctx->clone_roots,
|
|
bctx->sctx->clone_roots_cnt,
|
|
sizeof(struct clone_root),
|
|
__clone_root_cmp_bsearch);
|
|
if (!found)
|
|
return 0;
|
|
|
|
if (found->root == bctx->sctx->send_root &&
|
|
ino == bctx->cur_objectid &&
|
|
offset == bctx->cur_offset) {
|
|
bctx->found_itself = 1;
|
|
}
|
|
|
|
/*
|
|
* Make sure we don't consider clones from send_root that are
|
|
* behind the current inode/offset.
|
|
*/
|
|
if (found->root == bctx->sctx->send_root) {
|
|
/*
|
|
* If the source inode was not yet processed we can't issue a
|
|
* clone operation, as the source extent does not exist yet at
|
|
* the destination of the stream.
|
|
*/
|
|
if (ino > bctx->cur_objectid)
|
|
return 0;
|
|
/*
|
|
* We clone from the inode currently being sent as long as the
|
|
* source extent is already processed, otherwise we could try
|
|
* to clone from an extent that does not exist yet at the
|
|
* destination of the stream.
|
|
*/
|
|
if (ino == bctx->cur_objectid &&
|
|
offset + bctx->extent_len >
|
|
bctx->sctx->cur_inode_next_write_offset)
|
|
return 0;
|
|
}
|
|
|
|
bctx->found++;
|
|
found->found_refs++;
|
|
if (ino < found->ino) {
|
|
found->ino = ino;
|
|
found->offset = offset;
|
|
} else if (found->ino == ino) {
|
|
/*
|
|
* same extent found more then once in the same file.
|
|
*/
|
|
if (found->offset > offset + bctx->extent_len)
|
|
found->offset = offset;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Given an inode, offset and extent item, it finds a good clone for a clone
|
|
* instruction. Returns -ENOENT when none could be found. The function makes
|
|
* sure that the returned clone is usable at the point where sending is at the
|
|
* moment. This means, that no clones are accepted which lie behind the current
|
|
* inode+offset.
|
|
*
|
|
* path must point to the extent item when called.
|
|
*/
|
|
static int find_extent_clone(struct send_ctx *sctx,
|
|
struct btrfs_path *path,
|
|
u64 ino, u64 data_offset,
|
|
u64 ino_size,
|
|
struct clone_root **found)
|
|
{
|
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
|
|
int ret;
|
|
int extent_type;
|
|
u64 logical;
|
|
u64 disk_byte;
|
|
u64 num_bytes;
|
|
u64 extent_item_pos;
|
|
u64 flags = 0;
|
|
struct btrfs_file_extent_item *fi;
|
|
struct extent_buffer *eb = path->nodes[0];
|
|
struct backref_ctx backref_ctx = {0};
|
|
struct clone_root *cur_clone_root;
|
|
struct btrfs_key found_key;
|
|
struct btrfs_path *tmp_path;
|
|
struct btrfs_extent_item *ei;
|
|
int compressed;
|
|
u32 i;
|
|
|
|
tmp_path = alloc_path_for_send();
|
|
if (!tmp_path)
|
|
return -ENOMEM;
|
|
|
|
/* We only use this path under the commit sem */
|
|
tmp_path->need_commit_sem = 0;
|
|
|
|
if (data_offset >= ino_size) {
|
|
/*
|
|
* There may be extents that lie behind the file's size.
|
|
* I at least had this in combination with snapshotting while
|
|
* writing large files.
|
|
*/
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
fi = btrfs_item_ptr(eb, path->slots[0],
|
|
struct btrfs_file_extent_item);
|
|
extent_type = btrfs_file_extent_type(eb, fi);
|
|
if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
compressed = btrfs_file_extent_compression(eb, fi);
|
|
|
|
num_bytes = btrfs_file_extent_num_bytes(eb, fi);
|
|
disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);
|
|
if (disk_byte == 0) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
logical = disk_byte + btrfs_file_extent_offset(eb, fi);
|
|
|
|
down_read(&fs_info->commit_root_sem);
|
|
ret = extent_from_logical(fs_info, disk_byte, tmp_path,
|
|
&found_key, &flags);
|
|
up_read(&fs_info->commit_root_sem);
|
|
|
|
if (ret < 0)
|
|
goto out;
|
|
if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
|
|
ret = -EIO;
|
|
goto out;
|
|
}
|
|
|
|
ei = btrfs_item_ptr(tmp_path->nodes[0], tmp_path->slots[0],
|
|
struct btrfs_extent_item);
|
|
/*
|
|
* Backreference walking (iterate_extent_inodes() below) is currently
|
|
* too expensive when an extent has a large number of references, both
|
|
* in time spent and used memory. So for now just fallback to write
|
|
* operations instead of clone operations when an extent has more than
|
|
* a certain amount of references.
|
|
*/
|
|
if (btrfs_extent_refs(tmp_path->nodes[0], ei) > SEND_MAX_EXTENT_REFS) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
btrfs_release_path(tmp_path);
|
|
|
|
/*
|
|
* Setup the clone roots.
|
|
*/
|
|
for (i = 0; i < sctx->clone_roots_cnt; i++) {
|
|
cur_clone_root = sctx->clone_roots + i;
|
|
cur_clone_root->ino = (u64)-1;
|
|
cur_clone_root->offset = 0;
|
|
cur_clone_root->found_refs = 0;
|
|
}
|
|
|
|
backref_ctx.sctx = sctx;
|
|
backref_ctx.found = 0;
|
|
backref_ctx.cur_objectid = ino;
|
|
backref_ctx.cur_offset = data_offset;
|
|
backref_ctx.found_itself = 0;
|
|
backref_ctx.extent_len = num_bytes;
|
|
|
|
/*
|
|
* The last extent of a file may be too large due to page alignment.
|
|
* We need to adjust extent_len in this case so that the checks in
|
|
* __iterate_backrefs work.
|
|
*/
|
|
if (data_offset + num_bytes >= ino_size)
|
|
backref_ctx.extent_len = ino_size - data_offset;
|
|
|
|
/*
|
|
* Now collect all backrefs.
|
|
*/
|
|
if (compressed == BTRFS_COMPRESS_NONE)
|
|
extent_item_pos = logical - found_key.objectid;
|
|
else
|
|
extent_item_pos = 0;
|
|
ret = iterate_extent_inodes(fs_info, found_key.objectid,
|
|
extent_item_pos, 1, __iterate_backrefs,
|
|
&backref_ctx, false);
|
|
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
down_read(&fs_info->commit_root_sem);
|
|
if (fs_info->last_reloc_trans > sctx->last_reloc_trans) {
|
|
/*
|
|
* A transaction commit for a transaction in which block group
|
|
* relocation was done just happened.
|
|
* The disk_bytenr of the file extent item we processed is
|
|
* possibly stale, referring to the extent's location before
|
|
* relocation. So act as if we haven't found any clone sources
|
|
* and fallback to write commands, which will read the correct
|
|
* data from the new extent location. Otherwise we will fail
|
|
* below because we haven't found our own back reference or we
|
|
* could be getting incorrect sources in case the old extent
|
|
* was already reallocated after the relocation.
|
|
*/
|
|
up_read(&fs_info->commit_root_sem);
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
up_read(&fs_info->commit_root_sem);
|
|
|
|
if (!backref_ctx.found_itself) {
|
|
/* found a bug in backref code? */
|
|
ret = -EIO;
|
|
btrfs_err(fs_info,
|
|
"did not find backref in send_root. inode=%llu, offset=%llu, disk_byte=%llu found extent=%llu",
|
|
ino, data_offset, disk_byte, found_key.objectid);
|
|
goto out;
|
|
}
|
|
|
|
btrfs_debug(fs_info,
|
|
"find_extent_clone: data_offset=%llu, ino=%llu, num_bytes=%llu, logical=%llu",
|
|
data_offset, ino, num_bytes, logical);
|
|
|
|
if (!backref_ctx.found)
|
|
btrfs_debug(fs_info, "no clones found");
|
|
|
|
cur_clone_root = NULL;
|
|
for (i = 0; i < sctx->clone_roots_cnt; i++) {
|
|
if (sctx->clone_roots[i].found_refs) {
|
|
if (!cur_clone_root)
|
|
cur_clone_root = sctx->clone_roots + i;
|
|
else if (sctx->clone_roots[i].root == sctx->send_root)
|
|
/* prefer clones from send_root over others */
|
|
cur_clone_root = sctx->clone_roots + i;
|
|
}
|
|
|
|
}
|
|
|
|
if (cur_clone_root) {
|
|
*found = cur_clone_root;
|
|
ret = 0;
|
|
} else {
|
|
ret = -ENOENT;
|
|
}
|
|
|
|
out:
|
|
btrfs_free_path(tmp_path);
|
|
return ret;
|
|
}
|
|
|
|
static int read_symlink(struct btrfs_root *root,
|
|
u64 ino,
|
|
struct fs_path *dest)
|
|
{
|
|
int ret;
|
|
struct btrfs_path *path;
|
|
struct btrfs_key key;
|
|
struct btrfs_file_extent_item *ei;
|
|
u8 type;
|
|
u8 compression;
|
|
unsigned long off;
|
|
int len;
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
key.objectid = ino;
|
|
key.type = BTRFS_EXTENT_DATA_KEY;
|
|
key.offset = 0;
|
|
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret) {
|
|
/*
|
|
* An empty symlink inode. Can happen in rare error paths when
|
|
* creating a symlink (transaction committed before the inode
|
|
* eviction handler removed the symlink inode items and a crash
|
|
* happened in between or the subvol was snapshoted in between).
|
|
* Print an informative message to dmesg/syslog so that the user
|
|
* can delete the symlink.
|
|
*/
|
|
btrfs_err(root->fs_info,
|
|
"Found empty symlink inode %llu at root %llu",
|
|
ino, root->root_key.objectid);
|
|
ret = -EIO;
|
|
goto out;
|
|
}
|
|
|
|
ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
|
|
struct btrfs_file_extent_item);
|
|
type = btrfs_file_extent_type(path->nodes[0], ei);
|
|
compression = btrfs_file_extent_compression(path->nodes[0], ei);
|
|
BUG_ON(type != BTRFS_FILE_EXTENT_INLINE);
|
|
BUG_ON(compression);
|
|
|
|
off = btrfs_file_extent_inline_start(ei);
|
|
len = btrfs_file_extent_ram_bytes(path->nodes[0], ei);
|
|
|
|
ret = fs_path_add_from_extent_buffer(dest, path->nodes[0], off, len);
|
|
|
|
out:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Helper function to generate a file name that is unique in the root of
|
|
* send_root and parent_root. This is used to generate names for orphan inodes.
|
|
*/
|
|
static int gen_unique_name(struct send_ctx *sctx,
|
|
u64 ino, u64 gen,
|
|
struct fs_path *dest)
|
|
{
|
|
int ret = 0;
|
|
struct btrfs_path *path;
|
|
struct btrfs_dir_item *di;
|
|
char tmp[64];
|
|
int len;
|
|
u64 idx = 0;
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
while (1) {
|
|
len = snprintf(tmp, sizeof(tmp), "o%llu-%llu-%llu",
|
|
ino, gen, idx);
|
|
ASSERT(len < sizeof(tmp));
|
|
|
|
di = btrfs_lookup_dir_item(NULL, sctx->send_root,
|
|
path, BTRFS_FIRST_FREE_OBJECTID,
|
|
tmp, strlen(tmp), 0);
|
|
btrfs_release_path(path);
|
|
if (IS_ERR(di)) {
|
|
ret = PTR_ERR(di);
|
|
goto out;
|
|
}
|
|
if (di) {
|
|
/* not unique, try again */
|
|
idx++;
|
|
continue;
|
|
}
|
|
|
|
if (!sctx->parent_root) {
|
|
/* unique */
|
|
ret = 0;
|
|
break;
|
|
}
|
|
|
|
di = btrfs_lookup_dir_item(NULL, sctx->parent_root,
|
|
path, BTRFS_FIRST_FREE_OBJECTID,
|
|
tmp, strlen(tmp), 0);
|
|
btrfs_release_path(path);
|
|
if (IS_ERR(di)) {
|
|
ret = PTR_ERR(di);
|
|
goto out;
|
|
}
|
|
if (di) {
|
|
/* not unique, try again */
|
|
idx++;
|
|
continue;
|
|
}
|
|
/* unique */
|
|
break;
|
|
}
|
|
|
|
ret = fs_path_add(dest, tmp, strlen(tmp));
|
|
|
|
out:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
enum inode_state {
|
|
inode_state_no_change,
|
|
inode_state_will_create,
|
|
inode_state_did_create,
|
|
inode_state_will_delete,
|
|
inode_state_did_delete,
|
|
};
|
|
|
|
static int get_cur_inode_state(struct send_ctx *sctx, u64 ino, u64 gen)
|
|
{
|
|
int ret;
|
|
int left_ret;
|
|
int right_ret;
|
|
u64 left_gen;
|
|
u64 right_gen;
|
|
|
|
ret = get_inode_info(sctx->send_root, ino, NULL, &left_gen, NULL, NULL,
|
|
NULL, NULL);
|
|
if (ret < 0 && ret != -ENOENT)
|
|
goto out;
|
|
left_ret = ret;
|
|
|
|
if (!sctx->parent_root) {
|
|
right_ret = -ENOENT;
|
|
} else {
|
|
ret = get_inode_info(sctx->parent_root, ino, NULL, &right_gen,
|
|
NULL, NULL, NULL, NULL);
|
|
if (ret < 0 && ret != -ENOENT)
|
|
goto out;
|
|
right_ret = ret;
|
|
}
|
|
|
|
if (!left_ret && !right_ret) {
|
|
if (left_gen == gen && right_gen == gen) {
|
|
ret = inode_state_no_change;
|
|
} else if (left_gen == gen) {
|
|
if (ino < sctx->send_progress)
|
|
ret = inode_state_did_create;
|
|
else
|
|
ret = inode_state_will_create;
|
|
} else if (right_gen == gen) {
|
|
if (ino < sctx->send_progress)
|
|
ret = inode_state_did_delete;
|
|
else
|
|
ret = inode_state_will_delete;
|
|
} else {
|
|
ret = -ENOENT;
|
|
}
|
|
} else if (!left_ret) {
|
|
if (left_gen == gen) {
|
|
if (ino < sctx->send_progress)
|
|
ret = inode_state_did_create;
|
|
else
|
|
ret = inode_state_will_create;
|
|
} else {
|
|
ret = -ENOENT;
|
|
}
|
|
} else if (!right_ret) {
|
|
if (right_gen == gen) {
|
|
if (ino < sctx->send_progress)
|
|
ret = inode_state_did_delete;
|
|
else
|
|
ret = inode_state_will_delete;
|
|
} else {
|
|
ret = -ENOENT;
|
|
}
|
|
} else {
|
|
ret = -ENOENT;
|
|
}
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int is_inode_existent(struct send_ctx *sctx, u64 ino, u64 gen)
|
|
{
|
|
int ret;
|
|
|
|
if (ino == BTRFS_FIRST_FREE_OBJECTID)
|
|
return 1;
|
|
|
|
ret = get_cur_inode_state(sctx, ino, gen);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
if (ret == inode_state_no_change ||
|
|
ret == inode_state_did_create ||
|
|
ret == inode_state_will_delete)
|
|
ret = 1;
|
|
else
|
|
ret = 0;
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Helper function to lookup a dir item in a dir.
|
|
*/
|
|
static int lookup_dir_item_inode(struct btrfs_root *root,
|
|
u64 dir, const char *name, int name_len,
|
|
u64 *found_inode)
|
|
{
|
|
int ret = 0;
|
|
struct btrfs_dir_item *di;
|
|
struct btrfs_key key;
|
|
struct btrfs_path *path;
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
di = btrfs_lookup_dir_item(NULL, root, path,
|
|
dir, name, name_len, 0);
|
|
if (IS_ERR_OR_NULL(di)) {
|
|
ret = di ? PTR_ERR(di) : -ENOENT;
|
|
goto out;
|
|
}
|
|
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
|
|
if (key.type == BTRFS_ROOT_ITEM_KEY) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
*found_inode = key.objectid;
|
|
|
|
out:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Looks up the first btrfs_inode_ref of a given ino. It returns the parent dir,
|
|
* generation of the parent dir and the name of the dir entry.
|
|
*/
|
|
static int get_first_ref(struct btrfs_root *root, u64 ino,
|
|
u64 *dir, u64 *dir_gen, struct fs_path *name)
|
|
{
|
|
int ret;
|
|
struct btrfs_key key;
|
|
struct btrfs_key found_key;
|
|
struct btrfs_path *path;
|
|
int len;
|
|
u64 parent_dir;
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
key.objectid = ino;
|
|
key.type = BTRFS_INODE_REF_KEY;
|
|
key.offset = 0;
|
|
|
|
ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (!ret)
|
|
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
|
|
path->slots[0]);
|
|
if (ret || found_key.objectid != ino ||
|
|
(found_key.type != BTRFS_INODE_REF_KEY &&
|
|
found_key.type != BTRFS_INODE_EXTREF_KEY)) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
|
|
if (found_key.type == BTRFS_INODE_REF_KEY) {
|
|
struct btrfs_inode_ref *iref;
|
|
iref = btrfs_item_ptr(path->nodes[0], path->slots[0],
|
|
struct btrfs_inode_ref);
|
|
len = btrfs_inode_ref_name_len(path->nodes[0], iref);
|
|
ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
|
|
(unsigned long)(iref + 1),
|
|
len);
|
|
parent_dir = found_key.offset;
|
|
} else {
|
|
struct btrfs_inode_extref *extref;
|
|
extref = btrfs_item_ptr(path->nodes[0], path->slots[0],
|
|
struct btrfs_inode_extref);
|
|
len = btrfs_inode_extref_name_len(path->nodes[0], extref);
|
|
ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
|
|
(unsigned long)&extref->name, len);
|
|
parent_dir = btrfs_inode_extref_parent(path->nodes[0], extref);
|
|
}
|
|
if (ret < 0)
|
|
goto out;
|
|
btrfs_release_path(path);
|
|
|
|
if (dir_gen) {
|
|
ret = get_inode_info(root, parent_dir, NULL, dir_gen, NULL,
|
|
NULL, NULL, NULL);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
|
|
*dir = parent_dir;
|
|
|
|
out:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
static int is_first_ref(struct btrfs_root *root,
|
|
u64 ino, u64 dir,
|
|
const char *name, int name_len)
|
|
{
|
|
int ret;
|
|
struct fs_path *tmp_name;
|
|
u64 tmp_dir;
|
|
|
|
tmp_name = fs_path_alloc();
|
|
if (!tmp_name)
|
|
return -ENOMEM;
|
|
|
|
ret = get_first_ref(root, ino, &tmp_dir, NULL, tmp_name);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
if (dir != tmp_dir || name_len != fs_path_len(tmp_name)) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
ret = !memcmp(tmp_name->start, name, name_len);
|
|
|
|
out:
|
|
fs_path_free(tmp_name);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Used by process_recorded_refs to determine if a new ref would overwrite an
|
|
* already existing ref. In case it detects an overwrite, it returns the
|
|
* inode/gen in who_ino/who_gen.
|
|
* When an overwrite is detected, process_recorded_refs does proper orphanizing
|
|
* to make sure later references to the overwritten inode are possible.
|
|
* Orphanizing is however only required for the first ref of an inode.
|
|
* process_recorded_refs does an additional is_first_ref check to see if
|
|
* orphanizing is really required.
|
|
*/
|
|
static int will_overwrite_ref(struct send_ctx *sctx, u64 dir, u64 dir_gen,
|
|
const char *name, int name_len,
|
|
u64 *who_ino, u64 *who_gen, u64 *who_mode)
|
|
{
|
|
int ret = 0;
|
|
u64 gen;
|
|
u64 other_inode = 0;
|
|
|
|
if (!sctx->parent_root)
|
|
goto out;
|
|
|
|
ret = is_inode_existent(sctx, dir, dir_gen);
|
|
if (ret <= 0)
|
|
goto out;
|
|
|
|
/*
|
|
* If we have a parent root we need to verify that the parent dir was
|
|
* not deleted and then re-created, if it was then we have no overwrite
|
|
* and we can just unlink this entry.
|
|
*/
|
|
if (sctx->parent_root && dir != BTRFS_FIRST_FREE_OBJECTID) {
|
|
ret = get_inode_info(sctx->parent_root, dir, NULL, &gen, NULL,
|
|
NULL, NULL, NULL);
|
|
if (ret < 0 && ret != -ENOENT)
|
|
goto out;
|
|
if (ret) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
if (gen != dir_gen)
|
|
goto out;
|
|
}
|
|
|
|
ret = lookup_dir_item_inode(sctx->parent_root, dir, name, name_len,
|
|
&other_inode);
|
|
if (ret < 0 && ret != -ENOENT)
|
|
goto out;
|
|
if (ret) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Check if the overwritten ref was already processed. If yes, the ref
|
|
* was already unlinked/moved, so we can safely assume that we will not
|
|
* overwrite anything at this point in time.
|
|
*/
|
|
if (other_inode > sctx->send_progress ||
|
|
is_waiting_for_move(sctx, other_inode)) {
|
|
ret = get_inode_info(sctx->parent_root, other_inode, NULL,
|
|
who_gen, who_mode, NULL, NULL, NULL);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = 1;
|
|
*who_ino = other_inode;
|
|
} else {
|
|
ret = 0;
|
|
}
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Checks if the ref was overwritten by an already processed inode. This is
|
|
* used by __get_cur_name_and_parent to find out if the ref was orphanized and
|
|
* thus the orphan name needs be used.
|
|
* process_recorded_refs also uses it to avoid unlinking of refs that were
|
|
* overwritten.
|
|
*/
|
|
static int did_overwrite_ref(struct send_ctx *sctx,
|
|
u64 dir, u64 dir_gen,
|
|
u64 ino, u64 ino_gen,
|
|
const char *name, int name_len)
|
|
{
|
|
int ret = 0;
|
|
u64 gen;
|
|
u64 ow_inode;
|
|
|
|
if (!sctx->parent_root)
|
|
goto out;
|
|
|
|
ret = is_inode_existent(sctx, dir, dir_gen);
|
|
if (ret <= 0)
|
|
goto out;
|
|
|
|
if (dir != BTRFS_FIRST_FREE_OBJECTID) {
|
|
ret = get_inode_info(sctx->send_root, dir, NULL, &gen, NULL,
|
|
NULL, NULL, NULL);
|
|
if (ret < 0 && ret != -ENOENT)
|
|
goto out;
|
|
if (ret) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
if (gen != dir_gen)
|
|
goto out;
|
|
}
|
|
|
|
/* check if the ref was overwritten by another ref */
|
|
ret = lookup_dir_item_inode(sctx->send_root, dir, name, name_len,
|
|
&ow_inode);
|
|
if (ret < 0 && ret != -ENOENT)
|
|
goto out;
|
|
if (ret) {
|
|
/* was never and will never be overwritten */
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
ret = get_inode_info(sctx->send_root, ow_inode, NULL, &gen, NULL, NULL,
|
|
NULL, NULL);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
if (ow_inode == ino && gen == ino_gen) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* We know that it is or will be overwritten. Check this now.
|
|
* The current inode being processed might have been the one that caused
|
|
* inode 'ino' to be orphanized, therefore check if ow_inode matches
|
|
* the current inode being processed.
|
|
*/
|
|
if ((ow_inode < sctx->send_progress) ||
|
|
(ino != sctx->cur_ino && ow_inode == sctx->cur_ino &&
|
|
gen == sctx->cur_inode_gen))
|
|
ret = 1;
|
|
else
|
|
ret = 0;
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Same as did_overwrite_ref, but also checks if it is the first ref of an inode
|
|
* that got overwritten. This is used by process_recorded_refs to determine
|
|
* if it has to use the path as returned by get_cur_path or the orphan name.
|
|
*/
|
|
static int did_overwrite_first_ref(struct send_ctx *sctx, u64 ino, u64 gen)
|
|
{
|
|
int ret = 0;
|
|
struct fs_path *name = NULL;
|
|
u64 dir;
|
|
u64 dir_gen;
|
|
|
|
if (!sctx->parent_root)
|
|
goto out;
|
|
|
|
name = fs_path_alloc();
|
|
if (!name)
|
|
return -ENOMEM;
|
|
|
|
ret = get_first_ref(sctx->parent_root, ino, &dir, &dir_gen, name);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = did_overwrite_ref(sctx, dir, dir_gen, ino, gen,
|
|
name->start, fs_path_len(name));
|
|
|
|
out:
|
|
fs_path_free(name);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Insert a name cache entry. On 32bit kernels the xarray index is 32bit,
|
|
* so we need to do some special handling in case we have clashes. This function
|
|
* takes care of this with the help of name_cache_entry::inum_aliases.
|
|
* In case of error, nce is kfreed.
|
|
*/
|
|
static int name_cache_insert(struct send_ctx *sctx,
|
|
struct name_cache_entry *nce)
|
|
{
|
|
int ret = 0;
|
|
struct list_head *nce_head;
|
|
|
|
nce_head = xa_load(&sctx->name_cache, (unsigned long)nce->ino);
|
|
if (!nce_head) {
|
|
nce_head = kmalloc(sizeof(*nce_head), GFP_KERNEL);
|
|
if (!nce_head) {
|
|
kfree(nce);
|
|
return -ENOMEM;
|
|
}
|
|
INIT_LIST_HEAD(nce_head);
|
|
|
|
ret = xa_insert(&sctx->name_cache, nce->ino, nce_head, GFP_KERNEL);
|
|
if (ret < 0) {
|
|
kfree(nce_head);
|
|
kfree(nce);
|
|
return ret;
|
|
}
|
|
}
|
|
list_add_tail(&nce->inum_aliases, nce_head);
|
|
list_add_tail(&nce->list, &sctx->name_cache_list);
|
|
sctx->name_cache_size++;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void name_cache_delete(struct send_ctx *sctx,
|
|
struct name_cache_entry *nce)
|
|
{
|
|
struct list_head *nce_head;
|
|
|
|
nce_head = xa_load(&sctx->name_cache, (unsigned long)nce->ino);
|
|
if (!nce_head) {
|
|
btrfs_err(sctx->send_root->fs_info,
|
|
"name_cache_delete lookup failed ino %llu cache size %d, leaking memory",
|
|
nce->ino, sctx->name_cache_size);
|
|
}
|
|
|
|
list_del(&nce->inum_aliases);
|
|
list_del(&nce->list);
|
|
sctx->name_cache_size--;
|
|
|
|
/*
|
|
* We may not get to the final release of nce_head if the lookup fails
|
|
*/
|
|
if (nce_head && list_empty(nce_head)) {
|
|
xa_erase(&sctx->name_cache, (unsigned long)nce->ino);
|
|
kfree(nce_head);
|
|
}
|
|
}
|
|
|
|
static struct name_cache_entry *name_cache_search(struct send_ctx *sctx,
|
|
u64 ino, u64 gen)
|
|
{
|
|
struct list_head *nce_head;
|
|
struct name_cache_entry *cur;
|
|
|
|
nce_head = xa_load(&sctx->name_cache, (unsigned long)ino);
|
|
if (!nce_head)
|
|
return NULL;
|
|
|
|
list_for_each_entry(cur, nce_head, inum_aliases) {
|
|
if (cur->ino == ino && cur->gen == gen)
|
|
return cur;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Remove some entries from the beginning of name_cache_list.
|
|
*/
|
|
static void name_cache_clean_unused(struct send_ctx *sctx)
|
|
{
|
|
struct name_cache_entry *nce;
|
|
|
|
if (sctx->name_cache_size < SEND_CTX_NAME_CACHE_CLEAN_SIZE)
|
|
return;
|
|
|
|
while (sctx->name_cache_size > SEND_CTX_MAX_NAME_CACHE_SIZE) {
|
|
nce = list_entry(sctx->name_cache_list.next,
|
|
struct name_cache_entry, list);
|
|
name_cache_delete(sctx, nce);
|
|
kfree(nce);
|
|
}
|
|
}
|
|
|
|
static void name_cache_free(struct send_ctx *sctx)
|
|
{
|
|
struct name_cache_entry *nce;
|
|
|
|
while (!list_empty(&sctx->name_cache_list)) {
|
|
nce = list_entry(sctx->name_cache_list.next,
|
|
struct name_cache_entry, list);
|
|
name_cache_delete(sctx, nce);
|
|
kfree(nce);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Used by get_cur_path for each ref up to the root.
|
|
* Returns 0 if it succeeded.
|
|
* Returns 1 if the inode is not existent or got overwritten. In that case, the
|
|
* name is an orphan name. This instructs get_cur_path to stop iterating. If 1
|
|
* is returned, parent_ino/parent_gen are not guaranteed to be valid.
|
|
* Returns <0 in case of error.
|
|
*/
|
|
static int __get_cur_name_and_parent(struct send_ctx *sctx,
|
|
u64 ino, u64 gen,
|
|
u64 *parent_ino,
|
|
u64 *parent_gen,
|
|
struct fs_path *dest)
|
|
{
|
|
int ret;
|
|
int nce_ret;
|
|
struct name_cache_entry *nce = NULL;
|
|
|
|
/*
|
|
* First check if we already did a call to this function with the same
|
|
* ino/gen. If yes, check if the cache entry is still up-to-date. If yes
|
|
* return the cached result.
|
|
*/
|
|
nce = name_cache_search(sctx, ino, gen);
|
|
if (nce) {
|
|
if (ino < sctx->send_progress && nce->need_later_update) {
|
|
name_cache_delete(sctx, nce);
|
|
kfree(nce);
|
|
nce = NULL;
|
|
} else {
|
|
/*
|
|
* Removes the entry from the list and adds it back to
|
|
* the end. This marks the entry as recently used so
|
|
* that name_cache_clean_unused does not remove it.
|
|
*/
|
|
list_move_tail(&nce->list, &sctx->name_cache_list);
|
|
|
|
*parent_ino = nce->parent_ino;
|
|
*parent_gen = nce->parent_gen;
|
|
ret = fs_path_add(dest, nce->name, nce->name_len);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = nce->ret;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If the inode is not existent yet, add the orphan name and return 1.
|
|
* This should only happen for the parent dir that we determine in
|
|
* __record_new_ref
|
|
*/
|
|
ret = is_inode_existent(sctx, ino, gen);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
if (!ret) {
|
|
ret = gen_unique_name(sctx, ino, gen, dest);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = 1;
|
|
goto out_cache;
|
|
}
|
|
|
|
/*
|
|
* Depending on whether the inode was already processed or not, use
|
|
* send_root or parent_root for ref lookup.
|
|
*/
|
|
if (ino < sctx->send_progress)
|
|
ret = get_first_ref(sctx->send_root, ino,
|
|
parent_ino, parent_gen, dest);
|
|
else
|
|
ret = get_first_ref(sctx->parent_root, ino,
|
|
parent_ino, parent_gen, dest);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
/*
|
|
* Check if the ref was overwritten by an inode's ref that was processed
|
|
* earlier. If yes, treat as orphan and return 1.
|
|
*/
|
|
ret = did_overwrite_ref(sctx, *parent_ino, *parent_gen, ino, gen,
|
|
dest->start, dest->end - dest->start);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret) {
|
|
fs_path_reset(dest);
|
|
ret = gen_unique_name(sctx, ino, gen, dest);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = 1;
|
|
}
|
|
|
|
out_cache:
|
|
/*
|
|
* Store the result of the lookup in the name cache.
|
|
*/
|
|
nce = kmalloc(sizeof(*nce) + fs_path_len(dest) + 1, GFP_KERNEL);
|
|
if (!nce) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
nce->ino = ino;
|
|
nce->gen = gen;
|
|
nce->parent_ino = *parent_ino;
|
|
nce->parent_gen = *parent_gen;
|
|
nce->name_len = fs_path_len(dest);
|
|
nce->ret = ret;
|
|
strcpy(nce->name, dest->start);
|
|
|
|
if (ino < sctx->send_progress)
|
|
nce->need_later_update = 0;
|
|
else
|
|
nce->need_later_update = 1;
|
|
|
|
nce_ret = name_cache_insert(sctx, nce);
|
|
if (nce_ret < 0)
|
|
ret = nce_ret;
|
|
name_cache_clean_unused(sctx);
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Magic happens here. This function returns the first ref to an inode as it
|
|
* would look like while receiving the stream at this point in time.
|
|
* We walk the path up to the root. For every inode in between, we check if it
|
|
* was already processed/sent. If yes, we continue with the parent as found
|
|
* in send_root. If not, we continue with the parent as found in parent_root.
|
|
* If we encounter an inode that was deleted at this point in time, we use the
|
|
* inodes "orphan" name instead of the real name and stop. Same with new inodes
|
|
* that were not created yet and overwritten inodes/refs.
|
|
*
|
|
* When do we have orphan inodes:
|
|
* 1. When an inode is freshly created and thus no valid refs are available yet
|
|
* 2. When a directory lost all it's refs (deleted) but still has dir items
|
|
* inside which were not processed yet (pending for move/delete). If anyone
|
|
* tried to get the path to the dir items, it would get a path inside that
|
|
* orphan directory.
|
|
* 3. When an inode is moved around or gets new links, it may overwrite the ref
|
|
* of an unprocessed inode. If in that case the first ref would be
|
|
* overwritten, the overwritten inode gets "orphanized". Later when we
|
|
* process this overwritten inode, it is restored at a new place by moving
|
|
* the orphan inode.
|
|
*
|
|
* sctx->send_progress tells this function at which point in time receiving
|
|
* would be.
|
|
*/
|
|
static int get_cur_path(struct send_ctx *sctx, u64 ino, u64 gen,
|
|
struct fs_path *dest)
|
|
{
|
|
int ret = 0;
|
|
struct fs_path *name = NULL;
|
|
u64 parent_inode = 0;
|
|
u64 parent_gen = 0;
|
|
int stop = 0;
|
|
|
|
name = fs_path_alloc();
|
|
if (!name) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
dest->reversed = 1;
|
|
fs_path_reset(dest);
|
|
|
|
while (!stop && ino != BTRFS_FIRST_FREE_OBJECTID) {
|
|
struct waiting_dir_move *wdm;
|
|
|
|
fs_path_reset(name);
|
|
|
|
if (is_waiting_for_rm(sctx, ino, gen)) {
|
|
ret = gen_unique_name(sctx, ino, gen, name);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = fs_path_add_path(dest, name);
|
|
break;
|
|
}
|
|
|
|
wdm = get_waiting_dir_move(sctx, ino);
|
|
if (wdm && wdm->orphanized) {
|
|
ret = gen_unique_name(sctx, ino, gen, name);
|
|
stop = 1;
|
|
} else if (wdm) {
|
|
ret = get_first_ref(sctx->parent_root, ino,
|
|
&parent_inode, &parent_gen, name);
|
|
} else {
|
|
ret = __get_cur_name_and_parent(sctx, ino, gen,
|
|
&parent_inode,
|
|
&parent_gen, name);
|
|
if (ret)
|
|
stop = 1;
|
|
}
|
|
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = fs_path_add_path(dest, name);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ino = parent_inode;
|
|
gen = parent_gen;
|
|
}
|
|
|
|
out:
|
|
fs_path_free(name);
|
|
if (!ret)
|
|
fs_path_unreverse(dest);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Sends a BTRFS_SEND_C_SUBVOL command/item to userspace
|
|
*/
|
|
static int send_subvol_begin(struct send_ctx *sctx)
|
|
{
|
|
int ret;
|
|
struct btrfs_root *send_root = sctx->send_root;
|
|
struct btrfs_root *parent_root = sctx->parent_root;
|
|
struct btrfs_path *path;
|
|
struct btrfs_key key;
|
|
struct btrfs_root_ref *ref;
|
|
struct extent_buffer *leaf;
|
|
char *name = NULL;
|
|
int namelen;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
name = kmalloc(BTRFS_PATH_NAME_MAX, GFP_KERNEL);
|
|
if (!name) {
|
|
btrfs_free_path(path);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
key.objectid = send_root->root_key.objectid;
|
|
key.type = BTRFS_ROOT_BACKREF_KEY;
|
|
key.offset = 0;
|
|
|
|
ret = btrfs_search_slot_for_read(send_root->fs_info->tree_root,
|
|
&key, path, 1, 0);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
|
|
leaf = path->nodes[0];
|
|
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
|
|
if (key.type != BTRFS_ROOT_BACKREF_KEY ||
|
|
key.objectid != send_root->root_key.objectid) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
|
|
namelen = btrfs_root_ref_name_len(leaf, ref);
|
|
read_extent_buffer(leaf, name, (unsigned long)(ref + 1), namelen);
|
|
btrfs_release_path(path);
|
|
|
|
if (parent_root) {
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_SNAPSHOT);
|
|
if (ret < 0)
|
|
goto out;
|
|
} else {
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_SUBVOL);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
|
|
TLV_PUT_STRING(sctx, BTRFS_SEND_A_PATH, name, namelen);
|
|
|
|
if (!btrfs_is_empty_uuid(sctx->send_root->root_item.received_uuid))
|
|
TLV_PUT_UUID(sctx, BTRFS_SEND_A_UUID,
|
|
sctx->send_root->root_item.received_uuid);
|
|
else
|
|
TLV_PUT_UUID(sctx, BTRFS_SEND_A_UUID,
|
|
sctx->send_root->root_item.uuid);
|
|
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_CTRANSID,
|
|
btrfs_root_ctransid(&sctx->send_root->root_item));
|
|
if (parent_root) {
|
|
if (!btrfs_is_empty_uuid(parent_root->root_item.received_uuid))
|
|
TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
|
|
parent_root->root_item.received_uuid);
|
|
else
|
|
TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
|
|
parent_root->root_item.uuid);
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
|
|
btrfs_root_ctransid(&sctx->parent_root->root_item));
|
|
}
|
|
|
|
ret = send_cmd(sctx);
|
|
|
|
tlv_put_failure:
|
|
out:
|
|
btrfs_free_path(path);
|
|
kfree(name);
|
|
return ret;
|
|
}
|
|
|
|
static int send_truncate(struct send_ctx *sctx, u64 ino, u64 gen, u64 size)
|
|
{
|
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
|
|
int ret = 0;
|
|
struct fs_path *p;
|
|
|
|
btrfs_debug(fs_info, "send_truncate %llu size=%llu", ino, size);
|
|
|
|
p = fs_path_alloc();
|
|
if (!p)
|
|
return -ENOMEM;
|
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_TRUNCATE);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = get_cur_path(sctx, ino, gen, p);
|
|
if (ret < 0)
|
|
goto out;
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, size);
|
|
|
|
ret = send_cmd(sctx);
|
|
|
|
tlv_put_failure:
|
|
out:
|
|
fs_path_free(p);
|
|
return ret;
|
|
}
|
|
|
|
static int send_chmod(struct send_ctx *sctx, u64 ino, u64 gen, u64 mode)
|
|
{
|
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
|
|
int ret = 0;
|
|
struct fs_path *p;
|
|
|
|
btrfs_debug(fs_info, "send_chmod %llu mode=%llu", ino, mode);
|
|
|
|
p = fs_path_alloc();
|
|
if (!p)
|
|
return -ENOMEM;
|
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_CHMOD);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = get_cur_path(sctx, ino, gen, p);
|
|
if (ret < 0)
|
|
goto out;
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode & 07777);
|
|
|
|
ret = send_cmd(sctx);
|
|
|
|
tlv_put_failure:
|
|
out:
|
|
fs_path_free(p);
|
|
return ret;
|
|
}
|
|
|
|
static int send_chown(struct send_ctx *sctx, u64 ino, u64 gen, u64 uid, u64 gid)
|
|
{
|
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
|
|
int ret = 0;
|
|
struct fs_path *p;
|
|
|
|
btrfs_debug(fs_info, "send_chown %llu uid=%llu, gid=%llu",
|
|
ino, uid, gid);
|
|
|
|
p = fs_path_alloc();
|
|
if (!p)
|
|
return -ENOMEM;
|
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_CHOWN);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = get_cur_path(sctx, ino, gen, p);
|
|
if (ret < 0)
|
|
goto out;
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_UID, uid);
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_GID, gid);
|
|
|
|
ret = send_cmd(sctx);
|
|
|
|
tlv_put_failure:
|
|
out:
|
|
fs_path_free(p);
|
|
return ret;
|
|
}
|
|
|
|
static int send_utimes(struct send_ctx *sctx, u64 ino, u64 gen)
|
|
{
|
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
|
|
int ret = 0;
|
|
struct fs_path *p = NULL;
|
|
struct btrfs_inode_item *ii;
|
|
struct btrfs_path *path = NULL;
|
|
struct extent_buffer *eb;
|
|
struct btrfs_key key;
|
|
int slot;
|
|
|
|
btrfs_debug(fs_info, "send_utimes %llu", ino);
|
|
|
|
p = fs_path_alloc();
|
|
if (!p)
|
|
return -ENOMEM;
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
key.objectid = ino;
|
|
key.type = BTRFS_INODE_ITEM_KEY;
|
|
key.offset = 0;
|
|
ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0);
|
|
if (ret > 0)
|
|
ret = -ENOENT;
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
eb = path->nodes[0];
|
|
slot = path->slots[0];
|
|
ii = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
|
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_UTIMES);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = get_cur_path(sctx, ino, gen, p);
|
|
if (ret < 0)
|
|
goto out;
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
|
|
TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_ATIME, eb, &ii->atime);
|
|
TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_MTIME, eb, &ii->mtime);
|
|
TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_CTIME, eb, &ii->ctime);
|
|
/* TODO Add otime support when the otime patches get into upstream */
|
|
|
|
ret = send_cmd(sctx);
|
|
|
|
tlv_put_failure:
|
|
out:
|
|
fs_path_free(p);
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Sends a BTRFS_SEND_C_MKXXX or SYMLINK command to user space. We don't have
|
|
* a valid path yet because we did not process the refs yet. So, the inode
|
|
* is created as orphan.
|
|
*/
|
|
static int send_create_inode(struct send_ctx *sctx, u64 ino)
|
|
{
|
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
|
|
int ret = 0;
|
|
struct fs_path *p;
|
|
int cmd;
|
|
u64 gen;
|
|
u64 mode;
|
|
u64 rdev;
|
|
|
|
btrfs_debug(fs_info, "send_create_inode %llu", ino);
|
|
|
|
p = fs_path_alloc();
|
|
if (!p)
|
|
return -ENOMEM;
|
|
|
|
if (ino != sctx->cur_ino) {
|
|
ret = get_inode_info(sctx->send_root, ino, NULL, &gen, &mode,
|
|
NULL, NULL, &rdev);
|
|
if (ret < 0)
|
|
goto out;
|
|
} else {
|
|
gen = sctx->cur_inode_gen;
|
|
mode = sctx->cur_inode_mode;
|
|
rdev = sctx->cur_inode_rdev;
|
|
}
|
|
|
|
if (S_ISREG(mode)) {
|
|
cmd = BTRFS_SEND_C_MKFILE;
|
|
} else if (S_ISDIR(mode)) {
|
|
cmd = BTRFS_SEND_C_MKDIR;
|
|
} else if (S_ISLNK(mode)) {
|
|
cmd = BTRFS_SEND_C_SYMLINK;
|
|
} else if (S_ISCHR(mode) || S_ISBLK(mode)) {
|
|
cmd = BTRFS_SEND_C_MKNOD;
|
|
} else if (S_ISFIFO(mode)) {
|
|
cmd = BTRFS_SEND_C_MKFIFO;
|
|
} else if (S_ISSOCK(mode)) {
|
|
cmd = BTRFS_SEND_C_MKSOCK;
|
|
} else {
|
|
btrfs_warn(sctx->send_root->fs_info, "unexpected inode type %o",
|
|
(int)(mode & S_IFMT));
|
|
ret = -EOPNOTSUPP;
|
|
goto out;
|
|
}
|
|
|
|
ret = begin_cmd(sctx, cmd);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = gen_unique_name(sctx, ino, gen, p);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_INO, ino);
|
|
|
|
if (S_ISLNK(mode)) {
|
|
fs_path_reset(p);
|
|
ret = read_symlink(sctx->send_root, ino, p);
|
|
if (ret < 0)
|
|
goto out;
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, p);
|
|
} else if (S_ISCHR(mode) || S_ISBLK(mode) ||
|
|
S_ISFIFO(mode) || S_ISSOCK(mode)) {
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_RDEV, new_encode_dev(rdev));
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode);
|
|
}
|
|
|
|
ret = send_cmd(sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
|
|
tlv_put_failure:
|
|
out:
|
|
fs_path_free(p);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* We need some special handling for inodes that get processed before the parent
|
|
* directory got created. See process_recorded_refs for details.
|
|
* This function does the check if we already created the dir out of order.
|
|
*/
|
|
static int did_create_dir(struct send_ctx *sctx, u64 dir)
|
|
{
|
|
int ret = 0;
|
|
int iter_ret = 0;
|
|
struct btrfs_path *path = NULL;
|
|
struct btrfs_key key;
|
|
struct btrfs_key found_key;
|
|
struct btrfs_key di_key;
|
|
struct btrfs_dir_item *di;
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
key.objectid = dir;
|
|
key.type = BTRFS_DIR_INDEX_KEY;
|
|
key.offset = 0;
|
|
|
|
btrfs_for_each_slot(sctx->send_root, &key, &found_key, path, iter_ret) {
|
|
struct extent_buffer *eb = path->nodes[0];
|
|
|
|
if (found_key.objectid != key.objectid ||
|
|
found_key.type != key.type) {
|
|
ret = 0;
|
|
break;
|
|
}
|
|
|
|
di = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dir_item);
|
|
btrfs_dir_item_key_to_cpu(eb, di, &di_key);
|
|
|
|
if (di_key.type != BTRFS_ROOT_ITEM_KEY &&
|
|
di_key.objectid < sctx->send_progress) {
|
|
ret = 1;
|
|
break;
|
|
}
|
|
}
|
|
/* Catch error found during iteration */
|
|
if (iter_ret < 0)
|
|
ret = iter_ret;
|
|
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Only creates the inode if it is:
|
|
* 1. Not a directory
|
|
* 2. Or a directory which was not created already due to out of order
|
|
* directories. See did_create_dir and process_recorded_refs for details.
|
|
*/
|
|
static int send_create_inode_if_needed(struct send_ctx *sctx)
|
|
{
|
|
int ret;
|
|
|
|
if (S_ISDIR(sctx->cur_inode_mode)) {
|
|
ret = did_create_dir(sctx, sctx->cur_ino);
|
|
if (ret < 0)
|
|
return ret;
|
|
else if (ret > 0)
|
|
return 0;
|
|
}
|
|
|
|
return send_create_inode(sctx, sctx->cur_ino);
|
|
}
|
|
|
|
struct recorded_ref {
|
|
struct list_head list;
|
|
char *name;
|
|
struct fs_path *full_path;
|
|
u64 dir;
|
|
u64 dir_gen;
|
|
int name_len;
|
|
};
|
|
|
|
static void set_ref_path(struct recorded_ref *ref, struct fs_path *path)
|
|
{
|
|
ref->full_path = path;
|
|
ref->name = (char *)kbasename(ref->full_path->start);
|
|
ref->name_len = ref->full_path->end - ref->name;
|
|
}
|
|
|
|
/*
|
|
* We need to process new refs before deleted refs, but compare_tree gives us
|
|
* everything mixed. So we first record all refs and later process them.
|
|
* This function is a helper to record one ref.
|
|
*/
|
|
static int __record_ref(struct list_head *head, u64 dir,
|
|
u64 dir_gen, struct fs_path *path)
|
|
{
|
|
struct recorded_ref *ref;
|
|
|
|
ref = kmalloc(sizeof(*ref), GFP_KERNEL);
|
|
if (!ref)
|
|
return -ENOMEM;
|
|
|
|
ref->dir = dir;
|
|
ref->dir_gen = dir_gen;
|
|
set_ref_path(ref, path);
|
|
list_add_tail(&ref->list, head);
|
|
return 0;
|
|
}
|
|
|
|
static int dup_ref(struct recorded_ref *ref, struct list_head *list)
|
|
{
|
|
struct recorded_ref *new;
|
|
|
|
new = kmalloc(sizeof(*ref), GFP_KERNEL);
|
|
if (!new)
|
|
return -ENOMEM;
|
|
|
|
new->dir = ref->dir;
|
|
new->dir_gen = ref->dir_gen;
|
|
new->full_path = NULL;
|
|
INIT_LIST_HEAD(&new->list);
|
|
list_add_tail(&new->list, list);
|
|
return 0;
|
|
}
|
|
|
|
static void __free_recorded_refs(struct list_head *head)
|
|
{
|
|
struct recorded_ref *cur;
|
|
|
|
while (!list_empty(head)) {
|
|
cur = list_entry(head->next, struct recorded_ref, list);
|
|
fs_path_free(cur->full_path);
|
|
list_del(&cur->list);
|
|
kfree(cur);
|
|
}
|
|
}
|
|
|
|
static void free_recorded_refs(struct send_ctx *sctx)
|
|
{
|
|
__free_recorded_refs(&sctx->new_refs);
|
|
__free_recorded_refs(&sctx->deleted_refs);
|
|
}
|
|
|
|
/*
|
|
* Renames/moves a file/dir to its orphan name. Used when the first
|
|
* ref of an unprocessed inode gets overwritten and for all non empty
|
|
* directories.
|
|
*/
|
|
static int orphanize_inode(struct send_ctx *sctx, u64 ino, u64 gen,
|
|
struct fs_path *path)
|
|
{
|
|
int ret;
|
|
struct fs_path *orphan;
|
|
|
|
orphan = fs_path_alloc();
|
|
if (!orphan)
|
|
return -ENOMEM;
|
|
|
|
ret = gen_unique_name(sctx, ino, gen, orphan);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = send_rename(sctx, path, orphan);
|
|
|
|
out:
|
|
fs_path_free(orphan);
|
|
return ret;
|
|
}
|
|
|
|
static struct orphan_dir_info *add_orphan_dir_info(struct send_ctx *sctx,
|
|
u64 dir_ino, u64 dir_gen)
|
|
{
|
|
struct rb_node **p = &sctx->orphan_dirs.rb_node;
|
|
struct rb_node *parent = NULL;
|
|
struct orphan_dir_info *entry, *odi;
|
|
|
|
while (*p) {
|
|
parent = *p;
|
|
entry = rb_entry(parent, struct orphan_dir_info, node);
|
|
if (dir_ino < entry->ino)
|
|
p = &(*p)->rb_left;
|
|
else if (dir_ino > entry->ino)
|
|
p = &(*p)->rb_right;
|
|
else if (dir_gen < entry->gen)
|
|
p = &(*p)->rb_left;
|
|
else if (dir_gen > entry->gen)
|
|
p = &(*p)->rb_right;
|
|
else
|
|
return entry;
|
|
}
|
|
|
|
odi = kmalloc(sizeof(*odi), GFP_KERNEL);
|
|
if (!odi)
|
|
return ERR_PTR(-ENOMEM);
|
|
odi->ino = dir_ino;
|
|
odi->gen = dir_gen;
|
|
odi->last_dir_index_offset = 0;
|
|
|
|
rb_link_node(&odi->node, parent, p);
|
|
rb_insert_color(&odi->node, &sctx->orphan_dirs);
|
|
return odi;
|
|
}
|
|
|
|
static struct orphan_dir_info *get_orphan_dir_info(struct send_ctx *sctx,
|
|
u64 dir_ino, u64 gen)
|
|
{
|
|
struct rb_node *n = sctx->orphan_dirs.rb_node;
|
|
struct orphan_dir_info *entry;
|
|
|
|
while (n) {
|
|
entry = rb_entry(n, struct orphan_dir_info, node);
|
|
if (dir_ino < entry->ino)
|
|
n = n->rb_left;
|
|
else if (dir_ino > entry->ino)
|
|
n = n->rb_right;
|
|
else if (gen < entry->gen)
|
|
n = n->rb_left;
|
|
else if (gen > entry->gen)
|
|
n = n->rb_right;
|
|
else
|
|
return entry;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static int is_waiting_for_rm(struct send_ctx *sctx, u64 dir_ino, u64 gen)
|
|
{
|
|
struct orphan_dir_info *odi = get_orphan_dir_info(sctx, dir_ino, gen);
|
|
|
|
return odi != NULL;
|
|
}
|
|
|
|
static void free_orphan_dir_info(struct send_ctx *sctx,
|
|
struct orphan_dir_info *odi)
|
|
{
|
|
if (!odi)
|
|
return;
|
|
rb_erase(&odi->node, &sctx->orphan_dirs);
|
|
kfree(odi);
|
|
}
|
|
|
|
/*
|
|
* Returns 1 if a directory can be removed at this point in time.
|
|
* We check this by iterating all dir items and checking if the inode behind
|
|
* the dir item was already processed.
|
|
*/
|
|
static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 dir_gen,
|
|
u64 send_progress)
|
|
{
|
|
int ret = 0;
|
|
int iter_ret = 0;
|
|
struct btrfs_root *root = sctx->parent_root;
|
|
struct btrfs_path *path;
|
|
struct btrfs_key key;
|
|
struct btrfs_key found_key;
|
|
struct btrfs_key loc;
|
|
struct btrfs_dir_item *di;
|
|
struct orphan_dir_info *odi = NULL;
|
|
|
|
/*
|
|
* Don't try to rmdir the top/root subvolume dir.
|
|
*/
|
|
if (dir == BTRFS_FIRST_FREE_OBJECTID)
|
|
return 0;
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
key.objectid = dir;
|
|
key.type = BTRFS_DIR_INDEX_KEY;
|
|
key.offset = 0;
|
|
|
|
odi = get_orphan_dir_info(sctx, dir, dir_gen);
|
|
if (odi)
|
|
key.offset = odi->last_dir_index_offset;
|
|
|
|
btrfs_for_each_slot(root, &key, &found_key, path, iter_ret) {
|
|
struct waiting_dir_move *dm;
|
|
|
|
if (found_key.objectid != key.objectid ||
|
|
found_key.type != key.type)
|
|
break;
|
|
|
|
di = btrfs_item_ptr(path->nodes[0], path->slots[0],
|
|
struct btrfs_dir_item);
|
|
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &loc);
|
|
|
|
dm = get_waiting_dir_move(sctx, loc.objectid);
|
|
if (dm) {
|
|
odi = add_orphan_dir_info(sctx, dir, dir_gen);
|
|
if (IS_ERR(odi)) {
|
|
ret = PTR_ERR(odi);
|
|
goto out;
|
|
}
|
|
odi->gen = dir_gen;
|
|
odi->last_dir_index_offset = found_key.offset;
|
|
dm->rmdir_ino = dir;
|
|
dm->rmdir_gen = dir_gen;
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
if (loc.objectid > send_progress) {
|
|
odi = add_orphan_dir_info(sctx, dir, dir_gen);
|
|
if (IS_ERR(odi)) {
|
|
ret = PTR_ERR(odi);
|
|
goto out;
|
|
}
|
|
odi->gen = dir_gen;
|
|
odi->last_dir_index_offset = found_key.offset;
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
}
|
|
if (iter_ret < 0) {
|
|
ret = iter_ret;
|
|
goto out;
|
|
}
|
|
free_orphan_dir_info(sctx, odi);
|
|
|
|
ret = 1;
|
|
|
|
out:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
static int is_waiting_for_move(struct send_ctx *sctx, u64 ino)
|
|
{
|
|
struct waiting_dir_move *entry = get_waiting_dir_move(sctx, ino);
|
|
|
|
return entry != NULL;
|
|
}
|
|
|
|
static int add_waiting_dir_move(struct send_ctx *sctx, u64 ino, bool orphanized)
|
|
{
|
|
struct rb_node **p = &sctx->waiting_dir_moves.rb_node;
|
|
struct rb_node *parent = NULL;
|
|
struct waiting_dir_move *entry, *dm;
|
|
|
|
dm = kmalloc(sizeof(*dm), GFP_KERNEL);
|
|
if (!dm)
|
|
return -ENOMEM;
|
|
dm->ino = ino;
|
|
dm->rmdir_ino = 0;
|
|
dm->rmdir_gen = 0;
|
|
dm->orphanized = orphanized;
|
|
|
|
while (*p) {
|
|
parent = *p;
|
|
entry = rb_entry(parent, struct waiting_dir_move, node);
|
|
if (ino < entry->ino) {
|
|
p = &(*p)->rb_left;
|
|
} else if (ino > entry->ino) {
|
|
p = &(*p)->rb_right;
|
|
} else {
|
|
kfree(dm);
|
|
return -EEXIST;
|
|
}
|
|
}
|
|
|
|
rb_link_node(&dm->node, parent, p);
|
|
rb_insert_color(&dm->node, &sctx->waiting_dir_moves);
|
|
return 0;
|
|
}
|
|
|
|
static struct waiting_dir_move *
|
|
get_waiting_dir_move(struct send_ctx *sctx, u64 ino)
|
|
{
|
|
struct rb_node *n = sctx->waiting_dir_moves.rb_node;
|
|
struct waiting_dir_move *entry;
|
|
|
|
while (n) {
|
|
entry = rb_entry(n, struct waiting_dir_move, node);
|
|
if (ino < entry->ino)
|
|
n = n->rb_left;
|
|
else if (ino > entry->ino)
|
|
n = n->rb_right;
|
|
else
|
|
return entry;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static void free_waiting_dir_move(struct send_ctx *sctx,
|
|
struct waiting_dir_move *dm)
|
|
{
|
|
if (!dm)
|
|
return;
|
|
rb_erase(&dm->node, &sctx->waiting_dir_moves);
|
|
kfree(dm);
|
|
}
|
|
|
|
static int add_pending_dir_move(struct send_ctx *sctx,
|
|
u64 ino,
|
|
u64 ino_gen,
|
|
u64 parent_ino,
|
|
struct list_head *new_refs,
|
|
struct list_head *deleted_refs,
|
|
const bool is_orphan)
|
|
{
|
|
struct rb_node **p = &sctx->pending_dir_moves.rb_node;
|
|
struct rb_node *parent = NULL;
|
|
struct pending_dir_move *entry = NULL, *pm;
|
|
struct recorded_ref *cur;
|
|
int exists = 0;
|
|
int ret;
|
|
|
|
pm = kmalloc(sizeof(*pm), GFP_KERNEL);
|
|
if (!pm)
|
|
return -ENOMEM;
|
|
pm->parent_ino = parent_ino;
|
|
pm->ino = ino;
|
|
pm->gen = ino_gen;
|
|
INIT_LIST_HEAD(&pm->list);
|
|
INIT_LIST_HEAD(&pm->update_refs);
|
|
RB_CLEAR_NODE(&pm->node);
|
|
|
|
while (*p) {
|
|
parent = *p;
|
|
entry = rb_entry(parent, struct pending_dir_move, node);
|
|
if (parent_ino < entry->parent_ino) {
|
|
p = &(*p)->rb_left;
|
|
} else if (parent_ino > entry->parent_ino) {
|
|
p = &(*p)->rb_right;
|
|
} else {
|
|
exists = 1;
|
|
break;
|
|
}
|
|
}
|
|
|
|
list_for_each_entry(cur, deleted_refs, list) {
|
|
ret = dup_ref(cur, &pm->update_refs);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
list_for_each_entry(cur, new_refs, list) {
|
|
ret = dup_ref(cur, &pm->update_refs);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
|
|
ret = add_waiting_dir_move(sctx, pm->ino, is_orphan);
|
|
if (ret)
|
|
goto out;
|
|
|
|
if (exists) {
|
|
list_add_tail(&pm->list, &entry->list);
|
|
} else {
|
|
rb_link_node(&pm->node, parent, p);
|
|
rb_insert_color(&pm->node, &sctx->pending_dir_moves);
|
|
}
|
|
ret = 0;
|
|
out:
|
|
if (ret) {
|
|
__free_recorded_refs(&pm->update_refs);
|
|
kfree(pm);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static struct pending_dir_move *get_pending_dir_moves(struct send_ctx *sctx,
|
|
u64 parent_ino)
|
|
{
|
|
struct rb_node *n = sctx->pending_dir_moves.rb_node;
|
|
struct pending_dir_move *entry;
|
|
|
|
while (n) {
|
|
entry = rb_entry(n, struct pending_dir_move, node);
|
|
if (parent_ino < entry->parent_ino)
|
|
n = n->rb_left;
|
|
else if (parent_ino > entry->parent_ino)
|
|
n = n->rb_right;
|
|
else
|
|
return entry;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static int path_loop(struct send_ctx *sctx, struct fs_path *name,
|
|
u64 ino, u64 gen, u64 *ancestor_ino)
|
|
{
|
|
int ret = 0;
|
|
u64 parent_inode = 0;
|
|
u64 parent_gen = 0;
|
|
u64 start_ino = ino;
|
|
|
|
*ancestor_ino = 0;
|
|
while (ino != BTRFS_FIRST_FREE_OBJECTID) {
|
|
fs_path_reset(name);
|
|
|
|
if (is_waiting_for_rm(sctx, ino, gen))
|
|
break;
|
|
if (is_waiting_for_move(sctx, ino)) {
|
|
if (*ancestor_ino == 0)
|
|
*ancestor_ino = ino;
|
|
ret = get_first_ref(sctx->parent_root, ino,
|
|
&parent_inode, &parent_gen, name);
|
|
} else {
|
|
ret = __get_cur_name_and_parent(sctx, ino, gen,
|
|
&parent_inode,
|
|
&parent_gen, name);
|
|
if (ret > 0) {
|
|
ret = 0;
|
|
break;
|
|
}
|
|
}
|
|
if (ret < 0)
|
|
break;
|
|
if (parent_inode == start_ino) {
|
|
ret = 1;
|
|
if (*ancestor_ino == 0)
|
|
*ancestor_ino = ino;
|
|
break;
|
|
}
|
|
ino = parent_inode;
|
|
gen = parent_gen;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
|
|
{
|
|
struct fs_path *from_path = NULL;
|
|
struct fs_path *to_path = NULL;
|
|
struct fs_path *name = NULL;
|
|
u64 orig_progress = sctx->send_progress;
|
|
struct recorded_ref *cur;
|
|
u64 parent_ino, parent_gen;
|
|
struct waiting_dir_move *dm = NULL;
|
|
u64 rmdir_ino = 0;
|
|
u64 rmdir_gen;
|
|
u64 ancestor;
|
|
bool is_orphan;
|
|
int ret;
|
|
|
|
name = fs_path_alloc();
|
|
from_path = fs_path_alloc();
|
|
if (!name || !from_path) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
dm = get_waiting_dir_move(sctx, pm->ino);
|
|
ASSERT(dm);
|
|
rmdir_ino = dm->rmdir_ino;
|
|
rmdir_gen = dm->rmdir_gen;
|
|
is_orphan = dm->orphanized;
|
|
free_waiting_dir_move(sctx, dm);
|
|
|
|
if (is_orphan) {
|
|
ret = gen_unique_name(sctx, pm->ino,
|
|
pm->gen, from_path);
|
|
} else {
|
|
ret = get_first_ref(sctx->parent_root, pm->ino,
|
|
&parent_ino, &parent_gen, name);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = get_cur_path(sctx, parent_ino, parent_gen,
|
|
from_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = fs_path_add_path(from_path, name);
|
|
}
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
sctx->send_progress = sctx->cur_ino + 1;
|
|
ret = path_loop(sctx, name, pm->ino, pm->gen, &ancestor);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret) {
|
|
LIST_HEAD(deleted_refs);
|
|
ASSERT(ancestor > BTRFS_FIRST_FREE_OBJECTID);
|
|
ret = add_pending_dir_move(sctx, pm->ino, pm->gen, ancestor,
|
|
&pm->update_refs, &deleted_refs,
|
|
is_orphan);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (rmdir_ino) {
|
|
dm = get_waiting_dir_move(sctx, pm->ino);
|
|
ASSERT(dm);
|
|
dm->rmdir_ino = rmdir_ino;
|
|
dm->rmdir_gen = rmdir_gen;
|
|
}
|
|
goto out;
|
|
}
|
|
fs_path_reset(name);
|
|
to_path = name;
|
|
name = NULL;
|
|
ret = get_cur_path(sctx, pm->ino, pm->gen, to_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = send_rename(sctx, from_path, to_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
if (rmdir_ino) {
|
|
struct orphan_dir_info *odi;
|
|
u64 gen;
|
|
|
|
odi = get_orphan_dir_info(sctx, rmdir_ino, rmdir_gen);
|
|
if (!odi) {
|
|
/* already deleted */
|
|
goto finish;
|
|
}
|
|
gen = odi->gen;
|
|
|
|
ret = can_rmdir(sctx, rmdir_ino, gen, sctx->cur_ino);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (!ret)
|
|
goto finish;
|
|
|
|
name = fs_path_alloc();
|
|
if (!name) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
ret = get_cur_path(sctx, rmdir_ino, gen, name);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = send_rmdir(sctx, name);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
|
|
finish:
|
|
ret = send_utimes(sctx, pm->ino, pm->gen);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
/*
|
|
* After rename/move, need to update the utimes of both new parent(s)
|
|
* and old parent(s).
|
|
*/
|
|
list_for_each_entry(cur, &pm->update_refs, list) {
|
|
/*
|
|
* The parent inode might have been deleted in the send snapshot
|
|
*/
|
|
ret = get_inode_info(sctx->send_root, cur->dir, NULL,
|
|
NULL, NULL, NULL, NULL, NULL);
|
|
if (ret == -ENOENT) {
|
|
ret = 0;
|
|
continue;
|
|
}
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = send_utimes(sctx, cur->dir, cur->dir_gen);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
|
|
out:
|
|
fs_path_free(name);
|
|
fs_path_free(from_path);
|
|
fs_path_free(to_path);
|
|
sctx->send_progress = orig_progress;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void free_pending_move(struct send_ctx *sctx, struct pending_dir_move *m)
|
|
{
|
|
if (!list_empty(&m->list))
|
|
list_del(&m->list);
|
|
if (!RB_EMPTY_NODE(&m->node))
|
|
rb_erase(&m->node, &sctx->pending_dir_moves);
|
|
__free_recorded_refs(&m->update_refs);
|
|
kfree(m);
|
|
}
|
|
|
|
static void tail_append_pending_moves(struct send_ctx *sctx,
|
|
struct pending_dir_move *moves,
|
|
struct list_head *stack)
|
|
{
|
|
if (list_empty(&moves->list)) {
|
|
list_add_tail(&moves->list, stack);
|
|
} else {
|
|
LIST_HEAD(list);
|
|
list_splice_init(&moves->list, &list);
|
|
list_add_tail(&moves->list, stack);
|
|
list_splice_tail(&list, stack);
|
|
}
|
|
if (!RB_EMPTY_NODE(&moves->node)) {
|
|
rb_erase(&moves->node, &sctx->pending_dir_moves);
|
|
RB_CLEAR_NODE(&moves->node);
|
|
}
|
|
}
|
|
|
|
static int apply_children_dir_moves(struct send_ctx *sctx)
|
|
{
|
|
struct pending_dir_move *pm;
|
|
struct list_head stack;
|
|
u64 parent_ino = sctx->cur_ino;
|
|
int ret = 0;
|
|
|
|
pm = get_pending_dir_moves(sctx, parent_ino);
|
|
if (!pm)
|
|
return 0;
|
|
|
|
INIT_LIST_HEAD(&stack);
|
|
tail_append_pending_moves(sctx, pm, &stack);
|
|
|
|
while (!list_empty(&stack)) {
|
|
pm = list_first_entry(&stack, struct pending_dir_move, list);
|
|
parent_ino = pm->ino;
|
|
ret = apply_dir_move(sctx, pm);
|
|
free_pending_move(sctx, pm);
|
|
if (ret)
|
|
goto out;
|
|
pm = get_pending_dir_moves(sctx, parent_ino);
|
|
if (pm)
|
|
tail_append_pending_moves(sctx, pm, &stack);
|
|
}
|
|
return 0;
|
|
|
|
out:
|
|
while (!list_empty(&stack)) {
|
|
pm = list_first_entry(&stack, struct pending_dir_move, list);
|
|
free_pending_move(sctx, pm);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* We might need to delay a directory rename even when no ancestor directory
|
|
* (in the send root) with a higher inode number than ours (sctx->cur_ino) was
|
|
* renamed. This happens when we rename a directory to the old name (the name
|
|
* in the parent root) of some other unrelated directory that got its rename
|
|
* delayed due to some ancestor with higher number that got renamed.
|
|
*
|
|
* Example:
|
|
*
|
|
* Parent snapshot:
|
|
* . (ino 256)
|
|
* |---- a/ (ino 257)
|
|
* | |---- file (ino 260)
|
|
* |
|
|
* |---- b/ (ino 258)
|
|
* |---- c/ (ino 259)
|
|
*
|
|
* Send snapshot:
|
|
* . (ino 256)
|
|
* |---- a/ (ino 258)
|
|
* |---- x/ (ino 259)
|
|
* |---- y/ (ino 257)
|
|
* |----- file (ino 260)
|
|
*
|
|
* Here we can not rename 258 from 'b' to 'a' without the rename of inode 257
|
|
* from 'a' to 'x/y' happening first, which in turn depends on the rename of
|
|
* inode 259 from 'c' to 'x'. So the order of rename commands the send stream
|
|
* must issue is:
|
|
*
|
|
* 1 - rename 259 from 'c' to 'x'
|
|
* 2 - rename 257 from 'a' to 'x/y'
|
|
* 3 - rename 258 from 'b' to 'a'
|
|
*
|
|
* Returns 1 if the rename of sctx->cur_ino needs to be delayed, 0 if it can
|
|
* be done right away and < 0 on error.
|
|
*/
|
|
static int wait_for_dest_dir_move(struct send_ctx *sctx,
|
|
struct recorded_ref *parent_ref,
|
|
const bool is_orphan)
|
|
{
|
|
struct btrfs_fs_info *fs_info = sctx->parent_root->fs_info;
|
|
struct btrfs_path *path;
|
|
struct btrfs_key key;
|
|
struct btrfs_key di_key;
|
|
struct btrfs_dir_item *di;
|
|
u64 left_gen;
|
|
u64 right_gen;
|
|
int ret = 0;
|
|
struct waiting_dir_move *wdm;
|
|
|
|
if (RB_EMPTY_ROOT(&sctx->waiting_dir_moves))
|
|
return 0;
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
key.objectid = parent_ref->dir;
|
|
key.type = BTRFS_DIR_ITEM_KEY;
|
|
key.offset = btrfs_name_hash(parent_ref->name, parent_ref->name_len);
|
|
|
|
ret = btrfs_search_slot(NULL, sctx->parent_root, &key, path, 0, 0);
|
|
if (ret < 0) {
|
|
goto out;
|
|
} else if (ret > 0) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
di = btrfs_match_dir_item_name(fs_info, path, parent_ref->name,
|
|
parent_ref->name_len);
|
|
if (!di) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
/*
|
|
* di_key.objectid has the number of the inode that has a dentry in the
|
|
* parent directory with the same name that sctx->cur_ino is being
|
|
* renamed to. We need to check if that inode is in the send root as
|
|
* well and if it is currently marked as an inode with a pending rename,
|
|
* if it is, we need to delay the rename of sctx->cur_ino as well, so
|
|
* that it happens after that other inode is renamed.
|
|
*/
|
|
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &di_key);
|
|
if (di_key.type != BTRFS_INODE_ITEM_KEY) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
ret = get_inode_info(sctx->parent_root, di_key.objectid, NULL,
|
|
&left_gen, NULL, NULL, NULL, NULL);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = get_inode_info(sctx->send_root, di_key.objectid, NULL,
|
|
&right_gen, NULL, NULL, NULL, NULL);
|
|
if (ret < 0) {
|
|
if (ret == -ENOENT)
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
/* Different inode, no need to delay the rename of sctx->cur_ino */
|
|
if (right_gen != left_gen) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
wdm = get_waiting_dir_move(sctx, di_key.objectid);
|
|
if (wdm && !wdm->orphanized) {
|
|
ret = add_pending_dir_move(sctx,
|
|
sctx->cur_ino,
|
|
sctx->cur_inode_gen,
|
|
di_key.objectid,
|
|
&sctx->new_refs,
|
|
&sctx->deleted_refs,
|
|
is_orphan);
|
|
if (!ret)
|
|
ret = 1;
|
|
}
|
|
out:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Check if inode ino2, or any of its ancestors, is inode ino1.
|
|
* Return 1 if true, 0 if false and < 0 on error.
|
|
*/
|
|
static int check_ino_in_path(struct btrfs_root *root,
|
|
const u64 ino1,
|
|
const u64 ino1_gen,
|
|
const u64 ino2,
|
|
const u64 ino2_gen,
|
|
struct fs_path *fs_path)
|
|
{
|
|
u64 ino = ino2;
|
|
|
|
if (ino1 == ino2)
|
|
return ino1_gen == ino2_gen;
|
|
|
|
while (ino > BTRFS_FIRST_FREE_OBJECTID) {
|
|
u64 parent;
|
|
u64 parent_gen;
|
|
int ret;
|
|
|
|
fs_path_reset(fs_path);
|
|
ret = get_first_ref(root, ino, &parent, &parent_gen, fs_path);
|
|
if (ret < 0)
|
|
return ret;
|
|
if (parent == ino1)
|
|
return parent_gen == ino1_gen;
|
|
ino = parent;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Check if inode ino1 is an ancestor of inode ino2 in the given root for any
|
|
* possible path (in case ino2 is not a directory and has multiple hard links).
|
|
* Return 1 if true, 0 if false and < 0 on error.
|
|
*/
|
|
static int is_ancestor(struct btrfs_root *root,
|
|
const u64 ino1,
|
|
const u64 ino1_gen,
|
|
const u64 ino2,
|
|
struct fs_path *fs_path)
|
|
{
|
|
bool free_fs_path = false;
|
|
int ret = 0;
|
|
int iter_ret = 0;
|
|
struct btrfs_path *path = NULL;
|
|
struct btrfs_key key;
|
|
|
|
if (!fs_path) {
|
|
fs_path = fs_path_alloc();
|
|
if (!fs_path)
|
|
return -ENOMEM;
|
|
free_fs_path = true;
|
|
}
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
key.objectid = ino2;
|
|
key.type = BTRFS_INODE_REF_KEY;
|
|
key.offset = 0;
|
|
|
|
btrfs_for_each_slot(root, &key, &key, path, iter_ret) {
|
|
struct extent_buffer *leaf = path->nodes[0];
|
|
int slot = path->slots[0];
|
|
u32 cur_offset = 0;
|
|
u32 item_size;
|
|
|
|
if (key.objectid != ino2)
|
|
break;
|
|
if (key.type != BTRFS_INODE_REF_KEY &&
|
|
key.type != BTRFS_INODE_EXTREF_KEY)
|
|
break;
|
|
|
|
item_size = btrfs_item_size(leaf, slot);
|
|
while (cur_offset < item_size) {
|
|
u64 parent;
|
|
u64 parent_gen;
|
|
|
|
if (key.type == BTRFS_INODE_EXTREF_KEY) {
|
|
unsigned long ptr;
|
|
struct btrfs_inode_extref *extref;
|
|
|
|
ptr = btrfs_item_ptr_offset(leaf, slot);
|
|
extref = (struct btrfs_inode_extref *)
|
|
(ptr + cur_offset);
|
|
parent = btrfs_inode_extref_parent(leaf,
|
|
extref);
|
|
cur_offset += sizeof(*extref);
|
|
cur_offset += btrfs_inode_extref_name_len(leaf,
|
|
extref);
|
|
} else {
|
|
parent = key.offset;
|
|
cur_offset = item_size;
|
|
}
|
|
|
|
ret = get_inode_info(root, parent, NULL, &parent_gen,
|
|
NULL, NULL, NULL, NULL);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = check_ino_in_path(root, ino1, ino1_gen,
|
|
parent, parent_gen, fs_path);
|
|
if (ret)
|
|
goto out;
|
|
}
|
|
}
|
|
ret = 0;
|
|
if (iter_ret < 0)
|
|
ret = iter_ret;
|
|
|
|
out:
|
|
btrfs_free_path(path);
|
|
if (free_fs_path)
|
|
fs_path_free(fs_path);
|
|
return ret;
|
|
}
|
|
|
|
static int wait_for_parent_move(struct send_ctx *sctx,
|
|
struct recorded_ref *parent_ref,
|
|
const bool is_orphan)
|
|
{
|
|
int ret = 0;
|
|
u64 ino = parent_ref->dir;
|
|
u64 ino_gen = parent_ref->dir_gen;
|
|
u64 parent_ino_before, parent_ino_after;
|
|
struct fs_path *path_before = NULL;
|
|
struct fs_path *path_after = NULL;
|
|
int len1, len2;
|
|
|
|
path_after = fs_path_alloc();
|
|
path_before = fs_path_alloc();
|
|
if (!path_after || !path_before) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Our current directory inode may not yet be renamed/moved because some
|
|
* ancestor (immediate or not) has to be renamed/moved first. So find if
|
|
* such ancestor exists and make sure our own rename/move happens after
|
|
* that ancestor is processed to avoid path build infinite loops (done
|
|
* at get_cur_path()).
|
|
*/
|
|
while (ino > BTRFS_FIRST_FREE_OBJECTID) {
|
|
u64 parent_ino_after_gen;
|
|
|
|
if (is_waiting_for_move(sctx, ino)) {
|
|
/*
|
|
* If the current inode is an ancestor of ino in the
|
|
* parent root, we need to delay the rename of the
|
|
* current inode, otherwise don't delayed the rename
|
|
* because we can end up with a circular dependency
|
|
* of renames, resulting in some directories never
|
|
* getting the respective rename operations issued in
|
|
* the send stream or getting into infinite path build
|
|
* loops.
|
|
*/
|
|
ret = is_ancestor(sctx->parent_root,
|
|
sctx->cur_ino, sctx->cur_inode_gen,
|
|
ino, path_before);
|
|
if (ret)
|
|
break;
|
|
}
|
|
|
|
fs_path_reset(path_before);
|
|
fs_path_reset(path_after);
|
|
|
|
ret = get_first_ref(sctx->send_root, ino, &parent_ino_after,
|
|
&parent_ino_after_gen, path_after);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = get_first_ref(sctx->parent_root, ino, &parent_ino_before,
|
|
NULL, path_before);
|
|
if (ret < 0 && ret != -ENOENT) {
|
|
goto out;
|
|
} else if (ret == -ENOENT) {
|
|
ret = 0;
|
|
break;
|
|
}
|
|
|
|
len1 = fs_path_len(path_before);
|
|
len2 = fs_path_len(path_after);
|
|
if (ino > sctx->cur_ino &&
|
|
(parent_ino_before != parent_ino_after || len1 != len2 ||
|
|
memcmp(path_before->start, path_after->start, len1))) {
|
|
u64 parent_ino_gen;
|
|
|
|
ret = get_inode_info(sctx->parent_root, ino, NULL,
|
|
&parent_ino_gen, NULL, NULL, NULL,
|
|
NULL);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ino_gen == parent_ino_gen) {
|
|
ret = 1;
|
|
break;
|
|
}
|
|
}
|
|
ino = parent_ino_after;
|
|
ino_gen = parent_ino_after_gen;
|
|
}
|
|
|
|
out:
|
|
fs_path_free(path_before);
|
|
fs_path_free(path_after);
|
|
|
|
if (ret == 1) {
|
|
ret = add_pending_dir_move(sctx,
|
|
sctx->cur_ino,
|
|
sctx->cur_inode_gen,
|
|
ino,
|
|
&sctx->new_refs,
|
|
&sctx->deleted_refs,
|
|
is_orphan);
|
|
if (!ret)
|
|
ret = 1;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int update_ref_path(struct send_ctx *sctx, struct recorded_ref *ref)
|
|
{
|
|
int ret;
|
|
struct fs_path *new_path;
|
|
|
|
/*
|
|
* Our reference's name member points to its full_path member string, so
|
|
* we use here a new path.
|
|
*/
|
|
new_path = fs_path_alloc();
|
|
if (!new_path)
|
|
return -ENOMEM;
|
|
|
|
ret = get_cur_path(sctx, ref->dir, ref->dir_gen, new_path);
|
|
if (ret < 0) {
|
|
fs_path_free(new_path);
|
|
return ret;
|
|
}
|
|
ret = fs_path_add(new_path, ref->name, ref->name_len);
|
|
if (ret < 0) {
|
|
fs_path_free(new_path);
|
|
return ret;
|
|
}
|
|
|
|
fs_path_free(ref->full_path);
|
|
set_ref_path(ref, new_path);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* When processing the new references for an inode we may orphanize an existing
|
|
* directory inode because its old name conflicts with one of the new references
|
|
* of the current inode. Later, when processing another new reference of our
|
|
* inode, we might need to orphanize another inode, but the path we have in the
|
|
* reference reflects the pre-orphanization name of the directory we previously
|
|
* orphanized. For example:
|
|
*
|
|
* parent snapshot looks like:
|
|
*
|
|
* . (ino 256)
|
|
* |----- f1 (ino 257)
|
|
* |----- f2 (ino 258)
|
|
* |----- d1/ (ino 259)
|
|
* |----- d2/ (ino 260)
|
|
*
|
|
* send snapshot looks like:
|
|
*
|
|
* . (ino 256)
|
|
* |----- d1 (ino 258)
|
|
* |----- f2/ (ino 259)
|
|
* |----- f2_link/ (ino 260)
|
|
* | |----- f1 (ino 257)
|
|
* |
|
|
* |----- d2 (ino 258)
|
|
*
|
|
* When processing inode 257 we compute the name for inode 259 as "d1", and we
|
|
* cache it in the name cache. Later when we start processing inode 258, when
|
|
* collecting all its new references we set a full path of "d1/d2" for its new
|
|
* reference with name "d2". When we start processing the new references we
|
|
* start by processing the new reference with name "d1", and this results in
|
|
* orphanizing inode 259, since its old reference causes a conflict. Then we
|
|
* move on the next new reference, with name "d2", and we find out we must
|
|
* orphanize inode 260, as its old reference conflicts with ours - but for the
|
|
* orphanization we use a source path corresponding to the path we stored in the
|
|
* new reference, which is "d1/d2" and not "o259-6-0/d2" - this makes the
|
|
* receiver fail since the path component "d1/" no longer exists, it was renamed
|
|
* to "o259-6-0/" when processing the previous new reference. So in this case we
|
|
* must recompute the path in the new reference and use it for the new
|
|
* orphanization operation.
|
|
*/
|
|
static int refresh_ref_path(struct send_ctx *sctx, struct recorded_ref *ref)
|
|
{
|
|
char *name;
|
|
int ret;
|
|
|
|
name = kmemdup(ref->name, ref->name_len, GFP_KERNEL);
|
|
if (!name)
|
|
return -ENOMEM;
|
|
|
|
fs_path_reset(ref->full_path);
|
|
ret = get_cur_path(sctx, ref->dir, ref->dir_gen, ref->full_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = fs_path_add(ref->full_path, name, ref->name_len);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
/* Update the reference's base name pointer. */
|
|
set_ref_path(ref, ref->full_path);
|
|
out:
|
|
kfree(name);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* This does all the move/link/unlink/rmdir magic.
|
|
*/
|
|
static int process_recorded_refs(struct send_ctx *sctx, int *pending_move)
|
|
{
|
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
|
|
int ret = 0;
|
|
struct recorded_ref *cur;
|
|
struct recorded_ref *cur2;
|
|
struct list_head check_dirs;
|
|
struct fs_path *valid_path = NULL;
|
|
u64 ow_inode = 0;
|
|
u64 ow_gen;
|
|
u64 ow_mode;
|
|
int did_overwrite = 0;
|
|
int is_orphan = 0;
|
|
u64 last_dir_ino_rm = 0;
|
|
bool can_rename = true;
|
|
bool orphanized_dir = false;
|
|
bool orphanized_ancestor = false;
|
|
|
|
btrfs_debug(fs_info, "process_recorded_refs %llu", sctx->cur_ino);
|
|
|
|
/*
|
|
* This should never happen as the root dir always has the same ref
|
|
* which is always '..'
|
|
*/
|
|
BUG_ON(sctx->cur_ino <= BTRFS_FIRST_FREE_OBJECTID);
|
|
INIT_LIST_HEAD(&check_dirs);
|
|
|
|
valid_path = fs_path_alloc();
|
|
if (!valid_path) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* First, check if the first ref of the current inode was overwritten
|
|
* before. If yes, we know that the current inode was already orphanized
|
|
* and thus use the orphan name. If not, we can use get_cur_path to
|
|
* get the path of the first ref as it would like while receiving at
|
|
* this point in time.
|
|
* New inodes are always orphan at the beginning, so force to use the
|
|
* orphan name in this case.
|
|
* The first ref is stored in valid_path and will be updated if it
|
|
* gets moved around.
|
|
*/
|
|
if (!sctx->cur_inode_new) {
|
|
ret = did_overwrite_first_ref(sctx, sctx->cur_ino,
|
|
sctx->cur_inode_gen);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret)
|
|
did_overwrite = 1;
|
|
}
|
|
if (sctx->cur_inode_new || did_overwrite) {
|
|
ret = gen_unique_name(sctx, sctx->cur_ino,
|
|
sctx->cur_inode_gen, valid_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
is_orphan = 1;
|
|
} else {
|
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen,
|
|
valid_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Before doing any rename and link operations, do a first pass on the
|
|
* new references to orphanize any unprocessed inodes that may have a
|
|
* reference that conflicts with one of the new references of the current
|
|
* inode. This needs to happen first because a new reference may conflict
|
|
* with the old reference of a parent directory, so we must make sure
|
|
* that the path used for link and rename commands don't use an
|
|
* orphanized name when an ancestor was not yet orphanized.
|
|
*
|
|
* Example:
|
|
*
|
|
* Parent snapshot:
|
|
*
|
|
* . (ino 256)
|
|
* |----- testdir/ (ino 259)
|
|
* | |----- a (ino 257)
|
|
* |
|
|
* |----- b (ino 258)
|
|
*
|
|
* Send snapshot:
|
|
*
|
|
* . (ino 256)
|
|
* |----- testdir_2/ (ino 259)
|
|
* | |----- a (ino 260)
|
|
* |
|
|
* |----- testdir (ino 257)
|
|
* |----- b (ino 257)
|
|
* |----- b2 (ino 258)
|
|
*
|
|
* Processing the new reference for inode 257 with name "b" may happen
|
|
* before processing the new reference with name "testdir". If so, we
|
|
* must make sure that by the time we send a link command to create the
|
|
* hard link "b", inode 259 was already orphanized, since the generated
|
|
* path in "valid_path" already contains the orphanized name for 259.
|
|
* We are processing inode 257, so only later when processing 259 we do
|
|
* the rename operation to change its temporary (orphanized) name to
|
|
* "testdir_2".
|
|
*/
|
|
list_for_each_entry(cur, &sctx->new_refs, list) {
|
|
ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret == inode_state_will_create)
|
|
continue;
|
|
|
|
/*
|
|
* Check if this new ref would overwrite the first ref of another
|
|
* unprocessed inode. If yes, orphanize the overwritten inode.
|
|
* If we find an overwritten ref that is not the first ref,
|
|
* simply unlink it.
|
|
*/
|
|
ret = will_overwrite_ref(sctx, cur->dir, cur->dir_gen,
|
|
cur->name, cur->name_len,
|
|
&ow_inode, &ow_gen, &ow_mode);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret) {
|
|
ret = is_first_ref(sctx->parent_root,
|
|
ow_inode, cur->dir, cur->name,
|
|
cur->name_len);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret) {
|
|
struct name_cache_entry *nce;
|
|
struct waiting_dir_move *wdm;
|
|
|
|
if (orphanized_dir) {
|
|
ret = refresh_ref_path(sctx, cur);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
|
|
ret = orphanize_inode(sctx, ow_inode, ow_gen,
|
|
cur->full_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (S_ISDIR(ow_mode))
|
|
orphanized_dir = true;
|
|
|
|
/*
|
|
* If ow_inode has its rename operation delayed
|
|
* make sure that its orphanized name is used in
|
|
* the source path when performing its rename
|
|
* operation.
|
|
*/
|
|
if (is_waiting_for_move(sctx, ow_inode)) {
|
|
wdm = get_waiting_dir_move(sctx,
|
|
ow_inode);
|
|
ASSERT(wdm);
|
|
wdm->orphanized = true;
|
|
}
|
|
|
|
/*
|
|
* Make sure we clear our orphanized inode's
|
|
* name from the name cache. This is because the
|
|
* inode ow_inode might be an ancestor of some
|
|
* other inode that will be orphanized as well
|
|
* later and has an inode number greater than
|
|
* sctx->send_progress. We need to prevent
|
|
* future name lookups from using the old name
|
|
* and get instead the orphan name.
|
|
*/
|
|
nce = name_cache_search(sctx, ow_inode, ow_gen);
|
|
if (nce) {
|
|
name_cache_delete(sctx, nce);
|
|
kfree(nce);
|
|
}
|
|
|
|
/*
|
|
* ow_inode might currently be an ancestor of
|
|
* cur_ino, therefore compute valid_path (the
|
|
* current path of cur_ino) again because it
|
|
* might contain the pre-orphanization name of
|
|
* ow_inode, which is no longer valid.
|
|
*/
|
|
ret = is_ancestor(sctx->parent_root,
|
|
ow_inode, ow_gen,
|
|
sctx->cur_ino, NULL);
|
|
if (ret > 0) {
|
|
orphanized_ancestor = true;
|
|
fs_path_reset(valid_path);
|
|
ret = get_cur_path(sctx, sctx->cur_ino,
|
|
sctx->cur_inode_gen,
|
|
valid_path);
|
|
}
|
|
if (ret < 0)
|
|
goto out;
|
|
} else {
|
|
/*
|
|
* If we previously orphanized a directory that
|
|
* collided with a new reference that we already
|
|
* processed, recompute the current path because
|
|
* that directory may be part of the path.
|
|
*/
|
|
if (orphanized_dir) {
|
|
ret = refresh_ref_path(sctx, cur);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
ret = send_unlink(sctx, cur->full_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
list_for_each_entry(cur, &sctx->new_refs, list) {
|
|
/*
|
|
* We may have refs where the parent directory does not exist
|
|
* yet. This happens if the parent directories inum is higher
|
|
* than the current inum. To handle this case, we create the
|
|
* parent directory out of order. But we need to check if this
|
|
* did already happen before due to other refs in the same dir.
|
|
*/
|
|
ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret == inode_state_will_create) {
|
|
ret = 0;
|
|
/*
|
|
* First check if any of the current inodes refs did
|
|
* already create the dir.
|
|
*/
|
|
list_for_each_entry(cur2, &sctx->new_refs, list) {
|
|
if (cur == cur2)
|
|
break;
|
|
if (cur2->dir == cur->dir) {
|
|
ret = 1;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If that did not happen, check if a previous inode
|
|
* did already create the dir.
|
|
*/
|
|
if (!ret)
|
|
ret = did_create_dir(sctx, cur->dir);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (!ret) {
|
|
ret = send_create_inode(sctx, cur->dir);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (S_ISDIR(sctx->cur_inode_mode) && sctx->parent_root) {
|
|
ret = wait_for_dest_dir_move(sctx, cur, is_orphan);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret == 1) {
|
|
can_rename = false;
|
|
*pending_move = 1;
|
|
}
|
|
}
|
|
|
|
if (S_ISDIR(sctx->cur_inode_mode) && sctx->parent_root &&
|
|
can_rename) {
|
|
ret = wait_for_parent_move(sctx, cur, is_orphan);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret == 1) {
|
|
can_rename = false;
|
|
*pending_move = 1;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* link/move the ref to the new place. If we have an orphan
|
|
* inode, move it and update valid_path. If not, link or move
|
|
* it depending on the inode mode.
|
|
*/
|
|
if (is_orphan && can_rename) {
|
|
ret = send_rename(sctx, valid_path, cur->full_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
is_orphan = 0;
|
|
ret = fs_path_copy(valid_path, cur->full_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
} else if (can_rename) {
|
|
if (S_ISDIR(sctx->cur_inode_mode)) {
|
|
/*
|
|
* Dirs can't be linked, so move it. For moved
|
|
* dirs, we always have one new and one deleted
|
|
* ref. The deleted ref is ignored later.
|
|
*/
|
|
ret = send_rename(sctx, valid_path,
|
|
cur->full_path);
|
|
if (!ret)
|
|
ret = fs_path_copy(valid_path,
|
|
cur->full_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
} else {
|
|
/*
|
|
* We might have previously orphanized an inode
|
|
* which is an ancestor of our current inode,
|
|
* so our reference's full path, which was
|
|
* computed before any such orphanizations, must
|
|
* be updated.
|
|
*/
|
|
if (orphanized_dir) {
|
|
ret = update_ref_path(sctx, cur);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
ret = send_link(sctx, cur->full_path,
|
|
valid_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
}
|
|
ret = dup_ref(cur, &check_dirs);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
|
|
if (S_ISDIR(sctx->cur_inode_mode) && sctx->cur_inode_deleted) {
|
|
/*
|
|
* Check if we can already rmdir the directory. If not,
|
|
* orphanize it. For every dir item inside that gets deleted
|
|
* later, we do this check again and rmdir it then if possible.
|
|
* See the use of check_dirs for more details.
|
|
*/
|
|
ret = can_rmdir(sctx, sctx->cur_ino, sctx->cur_inode_gen,
|
|
sctx->cur_ino);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret) {
|
|
ret = send_rmdir(sctx, valid_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
} else if (!is_orphan) {
|
|
ret = orphanize_inode(sctx, sctx->cur_ino,
|
|
sctx->cur_inode_gen, valid_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
is_orphan = 1;
|
|
}
|
|
|
|
list_for_each_entry(cur, &sctx->deleted_refs, list) {
|
|
ret = dup_ref(cur, &check_dirs);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
} else if (S_ISDIR(sctx->cur_inode_mode) &&
|
|
!list_empty(&sctx->deleted_refs)) {
|
|
/*
|
|
* We have a moved dir. Add the old parent to check_dirs
|
|
*/
|
|
cur = list_entry(sctx->deleted_refs.next, struct recorded_ref,
|
|
list);
|
|
ret = dup_ref(cur, &check_dirs);
|
|
if (ret < 0)
|
|
goto out;
|
|
} else if (!S_ISDIR(sctx->cur_inode_mode)) {
|
|
/*
|
|
* We have a non dir inode. Go through all deleted refs and
|
|
* unlink them if they were not already overwritten by other
|
|
* inodes.
|
|
*/
|
|
list_for_each_entry(cur, &sctx->deleted_refs, list) {
|
|
ret = did_overwrite_ref(sctx, cur->dir, cur->dir_gen,
|
|
sctx->cur_ino, sctx->cur_inode_gen,
|
|
cur->name, cur->name_len);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (!ret) {
|
|
/*
|
|
* If we orphanized any ancestor before, we need
|
|
* to recompute the full path for deleted names,
|
|
* since any such path was computed before we
|
|
* processed any references and orphanized any
|
|
* ancestor inode.
|
|
*/
|
|
if (orphanized_ancestor) {
|
|
ret = update_ref_path(sctx, cur);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
ret = send_unlink(sctx, cur->full_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
ret = dup_ref(cur, &check_dirs);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
/*
|
|
* If the inode is still orphan, unlink the orphan. This may
|
|
* happen when a previous inode did overwrite the first ref
|
|
* of this inode and no new refs were added for the current
|
|
* inode. Unlinking does not mean that the inode is deleted in
|
|
* all cases. There may still be links to this inode in other
|
|
* places.
|
|
*/
|
|
if (is_orphan) {
|
|
ret = send_unlink(sctx, valid_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We did collect all parent dirs where cur_inode was once located. We
|
|
* now go through all these dirs and check if they are pending for
|
|
* deletion and if it's finally possible to perform the rmdir now.
|
|
* We also update the inode stats of the parent dirs here.
|
|
*/
|
|
list_for_each_entry(cur, &check_dirs, list) {
|
|
/*
|
|
* In case we had refs into dirs that were not processed yet,
|
|
* we don't need to do the utime and rmdir logic for these dirs.
|
|
* The dir will be processed later.
|
|
*/
|
|
if (cur->dir > sctx->cur_ino)
|
|
continue;
|
|
|
|
ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
if (ret == inode_state_did_create ||
|
|
ret == inode_state_no_change) {
|
|
/* TODO delayed utimes */
|
|
ret = send_utimes(sctx, cur->dir, cur->dir_gen);
|
|
if (ret < 0)
|
|
goto out;
|
|
} else if (ret == inode_state_did_delete &&
|
|
cur->dir != last_dir_ino_rm) {
|
|
ret = can_rmdir(sctx, cur->dir, cur->dir_gen,
|
|
sctx->cur_ino);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret) {
|
|
ret = get_cur_path(sctx, cur->dir,
|
|
cur->dir_gen, valid_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = send_rmdir(sctx, valid_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
last_dir_ino_rm = cur->dir;
|
|
}
|
|
}
|
|
}
|
|
|
|
ret = 0;
|
|
|
|
out:
|
|
__free_recorded_refs(&check_dirs);
|
|
free_recorded_refs(sctx);
|
|
fs_path_free(valid_path);
|
|
return ret;
|
|
}
|
|
|
|
static int record_ref(struct btrfs_root *root, u64 dir, struct fs_path *name,
|
|
void *ctx, struct list_head *refs)
|
|
{
|
|
int ret = 0;
|
|
struct send_ctx *sctx = ctx;
|
|
struct fs_path *p;
|
|
u64 gen;
|
|
|
|
p = fs_path_alloc();
|
|
if (!p)
|
|
return -ENOMEM;
|
|
|
|
ret = get_inode_info(root, dir, NULL, &gen, NULL, NULL,
|
|
NULL, NULL);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = get_cur_path(sctx, dir, gen, p);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = fs_path_add_path(p, name);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = __record_ref(refs, dir, gen, p);
|
|
|
|
out:
|
|
if (ret)
|
|
fs_path_free(p);
|
|
return ret;
|
|
}
|
|
|
|
static int __record_new_ref(int num, u64 dir, int index,
|
|
struct fs_path *name,
|
|
void *ctx)
|
|
{
|
|
struct send_ctx *sctx = ctx;
|
|
return record_ref(sctx->send_root, dir, name, ctx, &sctx->new_refs);
|
|
}
|
|
|
|
|
|
static int __record_deleted_ref(int num, u64 dir, int index,
|
|
struct fs_path *name,
|
|
void *ctx)
|
|
{
|
|
struct send_ctx *sctx = ctx;
|
|
return record_ref(sctx->parent_root, dir, name, ctx,
|
|
&sctx->deleted_refs);
|
|
}
|
|
|
|
static int record_new_ref(struct send_ctx *sctx)
|
|
{
|
|
int ret;
|
|
|
|
ret = iterate_inode_ref(sctx->send_root, sctx->left_path,
|
|
sctx->cmp_key, 0, __record_new_ref, sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = 0;
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int record_deleted_ref(struct send_ctx *sctx)
|
|
{
|
|
int ret;
|
|
|
|
ret = iterate_inode_ref(sctx->parent_root, sctx->right_path,
|
|
sctx->cmp_key, 0, __record_deleted_ref, sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = 0;
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
struct find_ref_ctx {
|
|
u64 dir;
|
|
u64 dir_gen;
|
|
struct btrfs_root *root;
|
|
struct fs_path *name;
|
|
int found_idx;
|
|
};
|
|
|
|
static int __find_iref(int num, u64 dir, int index,
|
|
struct fs_path *name,
|
|
void *ctx_)
|
|
{
|
|
struct find_ref_ctx *ctx = ctx_;
|
|
u64 dir_gen;
|
|
int ret;
|
|
|
|
if (dir == ctx->dir && fs_path_len(name) == fs_path_len(ctx->name) &&
|
|
strncmp(name->start, ctx->name->start, fs_path_len(name)) == 0) {
|
|
/*
|
|
* To avoid doing extra lookups we'll only do this if everything
|
|
* else matches.
|
|
*/
|
|
ret = get_inode_info(ctx->root, dir, NULL, &dir_gen, NULL,
|
|
NULL, NULL, NULL);
|
|
if (ret)
|
|
return ret;
|
|
if (dir_gen != ctx->dir_gen)
|
|
return 0;
|
|
ctx->found_idx = num;
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int find_iref(struct btrfs_root *root,
|
|
struct btrfs_path *path,
|
|
struct btrfs_key *key,
|
|
u64 dir, u64 dir_gen, struct fs_path *name)
|
|
{
|
|
int ret;
|
|
struct find_ref_ctx ctx;
|
|
|
|
ctx.dir = dir;
|
|
ctx.name = name;
|
|
ctx.dir_gen = dir_gen;
|
|
ctx.found_idx = -1;
|
|
ctx.root = root;
|
|
|
|
ret = iterate_inode_ref(root, path, key, 0, __find_iref, &ctx);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (ctx.found_idx == -1)
|
|
return -ENOENT;
|
|
|
|
return ctx.found_idx;
|
|
}
|
|
|
|
static int __record_changed_new_ref(int num, u64 dir, int index,
|
|
struct fs_path *name,
|
|
void *ctx)
|
|
{
|
|
u64 dir_gen;
|
|
int ret;
|
|
struct send_ctx *sctx = ctx;
|
|
|
|
ret = get_inode_info(sctx->send_root, dir, NULL, &dir_gen, NULL,
|
|
NULL, NULL, NULL);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = find_iref(sctx->parent_root, sctx->right_path,
|
|
sctx->cmp_key, dir, dir_gen, name);
|
|
if (ret == -ENOENT)
|
|
ret = __record_new_ref(num, dir, index, name, sctx);
|
|
else if (ret > 0)
|
|
ret = 0;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int __record_changed_deleted_ref(int num, u64 dir, int index,
|
|
struct fs_path *name,
|
|
void *ctx)
|
|
{
|
|
u64 dir_gen;
|
|
int ret;
|
|
struct send_ctx *sctx = ctx;
|
|
|
|
ret = get_inode_info(sctx->parent_root, dir, NULL, &dir_gen, NULL,
|
|
NULL, NULL, NULL);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = find_iref(sctx->send_root, sctx->left_path, sctx->cmp_key,
|
|
dir, dir_gen, name);
|
|
if (ret == -ENOENT)
|
|
ret = __record_deleted_ref(num, dir, index, name, sctx);
|
|
else if (ret > 0)
|
|
ret = 0;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int record_changed_ref(struct send_ctx *sctx)
|
|
{
|
|
int ret = 0;
|
|
|
|
ret = iterate_inode_ref(sctx->send_root, sctx->left_path,
|
|
sctx->cmp_key, 0, __record_changed_new_ref, sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = iterate_inode_ref(sctx->parent_root, sctx->right_path,
|
|
sctx->cmp_key, 0, __record_changed_deleted_ref, sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = 0;
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Record and process all refs at once. Needed when an inode changes the
|
|
* generation number, which means that it was deleted and recreated.
|
|
*/
|
|
static int process_all_refs(struct send_ctx *sctx,
|
|
enum btrfs_compare_tree_result cmd)
|
|
{
|
|
int ret = 0;
|
|
int iter_ret = 0;
|
|
struct btrfs_root *root;
|
|
struct btrfs_path *path;
|
|
struct btrfs_key key;
|
|
struct btrfs_key found_key;
|
|
iterate_inode_ref_t cb;
|
|
int pending_move = 0;
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
if (cmd == BTRFS_COMPARE_TREE_NEW) {
|
|
root = sctx->send_root;
|
|
cb = __record_new_ref;
|
|
} else if (cmd == BTRFS_COMPARE_TREE_DELETED) {
|
|
root = sctx->parent_root;
|
|
cb = __record_deleted_ref;
|
|
} else {
|
|
btrfs_err(sctx->send_root->fs_info,
|
|
"Wrong command %d in process_all_refs", cmd);
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
key.objectid = sctx->cmp_key->objectid;
|
|
key.type = BTRFS_INODE_REF_KEY;
|
|
key.offset = 0;
|
|
btrfs_for_each_slot(root, &key, &found_key, path, iter_ret) {
|
|
if (found_key.objectid != key.objectid ||
|
|
(found_key.type != BTRFS_INODE_REF_KEY &&
|
|
found_key.type != BTRFS_INODE_EXTREF_KEY))
|
|
break;
|
|
|
|
ret = iterate_inode_ref(root, path, &found_key, 0, cb, sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
/* Catch error found during iteration */
|
|
if (iter_ret < 0) {
|
|
ret = iter_ret;
|
|
goto out;
|
|
}
|
|
btrfs_release_path(path);
|
|
|
|
/*
|
|
* We don't actually care about pending_move as we are simply
|
|
* re-creating this inode and will be rename'ing it into place once we
|
|
* rename the parent directory.
|
|
*/
|
|
ret = process_recorded_refs(sctx, &pending_move);
|
|
out:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
static int send_set_xattr(struct send_ctx *sctx,
|
|
struct fs_path *path,
|
|
const char *name, int name_len,
|
|
const char *data, int data_len)
|
|
{
|
|
int ret = 0;
|
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_SET_XATTR);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
|
|
TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len);
|
|
TLV_PUT(sctx, BTRFS_SEND_A_XATTR_DATA, data, data_len);
|
|
|
|
ret = send_cmd(sctx);
|
|
|
|
tlv_put_failure:
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int send_remove_xattr(struct send_ctx *sctx,
|
|
struct fs_path *path,
|
|
const char *name, int name_len)
|
|
{
|
|
int ret = 0;
|
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_REMOVE_XATTR);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
|
|
TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len);
|
|
|
|
ret = send_cmd(sctx);
|
|
|
|
tlv_put_failure:
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int __process_new_xattr(int num, struct btrfs_key *di_key,
|
|
const char *name, int name_len, const char *data,
|
|
int data_len, void *ctx)
|
|
{
|
|
int ret;
|
|
struct send_ctx *sctx = ctx;
|
|
struct fs_path *p;
|
|
struct posix_acl_xattr_header dummy_acl;
|
|
|
|
/* Capabilities are emitted by finish_inode_if_needed */
|
|
if (!strncmp(name, XATTR_NAME_CAPS, name_len))
|
|
return 0;
|
|
|
|
p = fs_path_alloc();
|
|
if (!p)
|
|
return -ENOMEM;
|
|
|
|
/*
|
|
* This hack is needed because empty acls are stored as zero byte
|
|
* data in xattrs. Problem with that is, that receiving these zero byte
|
|
* acls will fail later. To fix this, we send a dummy acl list that
|
|
* only contains the version number and no entries.
|
|
*/
|
|
if (!strncmp(name, XATTR_NAME_POSIX_ACL_ACCESS, name_len) ||
|
|
!strncmp(name, XATTR_NAME_POSIX_ACL_DEFAULT, name_len)) {
|
|
if (data_len == 0) {
|
|
dummy_acl.a_version =
|
|
cpu_to_le32(POSIX_ACL_XATTR_VERSION);
|
|
data = (char *)&dummy_acl;
|
|
data_len = sizeof(dummy_acl);
|
|
}
|
|
}
|
|
|
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = send_set_xattr(sctx, p, name, name_len, data, data_len);
|
|
|
|
out:
|
|
fs_path_free(p);
|
|
return ret;
|
|
}
|
|
|
|
static int __process_deleted_xattr(int num, struct btrfs_key *di_key,
|
|
const char *name, int name_len,
|
|
const char *data, int data_len, void *ctx)
|
|
{
|
|
int ret;
|
|
struct send_ctx *sctx = ctx;
|
|
struct fs_path *p;
|
|
|
|
p = fs_path_alloc();
|
|
if (!p)
|
|
return -ENOMEM;
|
|
|
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = send_remove_xattr(sctx, p, name, name_len);
|
|
|
|
out:
|
|
fs_path_free(p);
|
|
return ret;
|
|
}
|
|
|
|
static int process_new_xattr(struct send_ctx *sctx)
|
|
{
|
|
int ret = 0;
|
|
|
|
ret = iterate_dir_item(sctx->send_root, sctx->left_path,
|
|
__process_new_xattr, sctx);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int process_deleted_xattr(struct send_ctx *sctx)
|
|
{
|
|
return iterate_dir_item(sctx->parent_root, sctx->right_path,
|
|
__process_deleted_xattr, sctx);
|
|
}
|
|
|
|
struct find_xattr_ctx {
|
|
const char *name;
|
|
int name_len;
|
|
int found_idx;
|
|
char *found_data;
|
|
int found_data_len;
|
|
};
|
|
|
|
static int __find_xattr(int num, struct btrfs_key *di_key, const char *name,
|
|
int name_len, const char *data, int data_len, void *vctx)
|
|
{
|
|
struct find_xattr_ctx *ctx = vctx;
|
|
|
|
if (name_len == ctx->name_len &&
|
|
strncmp(name, ctx->name, name_len) == 0) {
|
|
ctx->found_idx = num;
|
|
ctx->found_data_len = data_len;
|
|
ctx->found_data = kmemdup(data, data_len, GFP_KERNEL);
|
|
if (!ctx->found_data)
|
|
return -ENOMEM;
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int find_xattr(struct btrfs_root *root,
|
|
struct btrfs_path *path,
|
|
struct btrfs_key *key,
|
|
const char *name, int name_len,
|
|
char **data, int *data_len)
|
|
{
|
|
int ret;
|
|
struct find_xattr_ctx ctx;
|
|
|
|
ctx.name = name;
|
|
ctx.name_len = name_len;
|
|
ctx.found_idx = -1;
|
|
ctx.found_data = NULL;
|
|
ctx.found_data_len = 0;
|
|
|
|
ret = iterate_dir_item(root, path, __find_xattr, &ctx);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (ctx.found_idx == -1)
|
|
return -ENOENT;
|
|
if (data) {
|
|
*data = ctx.found_data;
|
|
*data_len = ctx.found_data_len;
|
|
} else {
|
|
kfree(ctx.found_data);
|
|
}
|
|
return ctx.found_idx;
|
|
}
|
|
|
|
|
|
static int __process_changed_new_xattr(int num, struct btrfs_key *di_key,
|
|
const char *name, int name_len,
|
|
const char *data, int data_len,
|
|
void *ctx)
|
|
{
|
|
int ret;
|
|
struct send_ctx *sctx = ctx;
|
|
char *found_data = NULL;
|
|
int found_data_len = 0;
|
|
|
|
ret = find_xattr(sctx->parent_root, sctx->right_path,
|
|
sctx->cmp_key, name, name_len, &found_data,
|
|
&found_data_len);
|
|
if (ret == -ENOENT) {
|
|
ret = __process_new_xattr(num, di_key, name, name_len, data,
|
|
data_len, ctx);
|
|
} else if (ret >= 0) {
|
|
if (data_len != found_data_len ||
|
|
memcmp(data, found_data, data_len)) {
|
|
ret = __process_new_xattr(num, di_key, name, name_len,
|
|
data, data_len, ctx);
|
|
} else {
|
|
ret = 0;
|
|
}
|
|
}
|
|
|
|
kfree(found_data);
|
|
return ret;
|
|
}
|
|
|
|
static int __process_changed_deleted_xattr(int num, struct btrfs_key *di_key,
|
|
const char *name, int name_len,
|
|
const char *data, int data_len,
|
|
void *ctx)
|
|
{
|
|
int ret;
|
|
struct send_ctx *sctx = ctx;
|
|
|
|
ret = find_xattr(sctx->send_root, sctx->left_path, sctx->cmp_key,
|
|
name, name_len, NULL, NULL);
|
|
if (ret == -ENOENT)
|
|
ret = __process_deleted_xattr(num, di_key, name, name_len, data,
|
|
data_len, ctx);
|
|
else if (ret >= 0)
|
|
ret = 0;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int process_changed_xattr(struct send_ctx *sctx)
|
|
{
|
|
int ret = 0;
|
|
|
|
ret = iterate_dir_item(sctx->send_root, sctx->left_path,
|
|
__process_changed_new_xattr, sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = iterate_dir_item(sctx->parent_root, sctx->right_path,
|
|
__process_changed_deleted_xattr, sctx);
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int process_all_new_xattrs(struct send_ctx *sctx)
|
|
{
|
|
int ret = 0;
|
|
int iter_ret = 0;
|
|
struct btrfs_root *root;
|
|
struct btrfs_path *path;
|
|
struct btrfs_key key;
|
|
struct btrfs_key found_key;
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
root = sctx->send_root;
|
|
|
|
key.objectid = sctx->cmp_key->objectid;
|
|
key.type = BTRFS_XATTR_ITEM_KEY;
|
|
key.offset = 0;
|
|
btrfs_for_each_slot(root, &key, &found_key, path, iter_ret) {
|
|
if (found_key.objectid != key.objectid ||
|
|
found_key.type != key.type) {
|
|
ret = 0;
|
|
break;
|
|
}
|
|
|
|
ret = iterate_dir_item(root, path, __process_new_xattr, sctx);
|
|
if (ret < 0)
|
|
break;
|
|
}
|
|
/* Catch error found during iteration */
|
|
if (iter_ret < 0)
|
|
ret = iter_ret;
|
|
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
static inline u64 max_send_read_size(const struct send_ctx *sctx)
|
|
{
|
|
return sctx->send_max_size - SZ_16K;
|
|
}
|
|
|
|
static int put_data_header(struct send_ctx *sctx, u32 len)
|
|
{
|
|
struct btrfs_tlv_header *hdr;
|
|
|
|
if (sctx->send_max_size - sctx->send_size < sizeof(*hdr) + len)
|
|
return -EOVERFLOW;
|
|
hdr = (struct btrfs_tlv_header *)(sctx->send_buf + sctx->send_size);
|
|
put_unaligned_le16(BTRFS_SEND_A_DATA, &hdr->tlv_type);
|
|
put_unaligned_le16(len, &hdr->tlv_len);
|
|
sctx->send_size += sizeof(*hdr);
|
|
return 0;
|
|
}
|
|
|
|
static int put_file_data(struct send_ctx *sctx, u64 offset, u32 len)
|
|
{
|
|
struct btrfs_root *root = sctx->send_root;
|
|
struct btrfs_fs_info *fs_info = root->fs_info;
|
|
struct page *page;
|
|
pgoff_t index = offset >> PAGE_SHIFT;
|
|
pgoff_t last_index;
|
|
unsigned pg_offset = offset_in_page(offset);
|
|
int ret;
|
|
|
|
ret = put_data_header(sctx, len);
|
|
if (ret)
|
|
return ret;
|
|
|
|
last_index = (offset + len - 1) >> PAGE_SHIFT;
|
|
|
|
while (index <= last_index) {
|
|
unsigned cur_len = min_t(unsigned, len,
|
|
PAGE_SIZE - pg_offset);
|
|
|
|
page = find_lock_page(sctx->cur_inode->i_mapping, index);
|
|
if (!page) {
|
|
page_cache_sync_readahead(sctx->cur_inode->i_mapping,
|
|
&sctx->ra, NULL, index,
|
|
last_index + 1 - index);
|
|
|
|
page = find_or_create_page(sctx->cur_inode->i_mapping,
|
|
index, GFP_KERNEL);
|
|
if (!page) {
|
|
ret = -ENOMEM;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (PageReadahead(page))
|
|
page_cache_async_readahead(sctx->cur_inode->i_mapping,
|
|
&sctx->ra, NULL, page_folio(page),
|
|
index, last_index + 1 - index);
|
|
|
|
if (!PageUptodate(page)) {
|
|
btrfs_read_folio(NULL, page_folio(page));
|
|
lock_page(page);
|
|
if (!PageUptodate(page)) {
|
|
unlock_page(page);
|
|
btrfs_err(fs_info,
|
|
"send: IO error at offset %llu for inode %llu root %llu",
|
|
page_offset(page), sctx->cur_ino,
|
|
sctx->send_root->root_key.objectid);
|
|
put_page(page);
|
|
ret = -EIO;
|
|
break;
|
|
}
|
|
}
|
|
|
|
memcpy_from_page(sctx->send_buf + sctx->send_size, page,
|
|
pg_offset, cur_len);
|
|
unlock_page(page);
|
|
put_page(page);
|
|
index++;
|
|
pg_offset = 0;
|
|
len -= cur_len;
|
|
sctx->send_size += cur_len;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Read some bytes from the current inode/file and send a write command to
|
|
* user space.
|
|
*/
|
|
static int send_write(struct send_ctx *sctx, u64 offset, u32 len)
|
|
{
|
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
|
|
int ret = 0;
|
|
struct fs_path *p;
|
|
|
|
p = fs_path_alloc();
|
|
if (!p)
|
|
return -ENOMEM;
|
|
|
|
btrfs_debug(fs_info, "send_write offset=%llu, len=%d", offset, len);
|
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
|
|
ret = put_file_data(sctx, offset, len);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = send_cmd(sctx);
|
|
|
|
tlv_put_failure:
|
|
out:
|
|
fs_path_free(p);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Send a clone command to user space.
|
|
*/
|
|
static int send_clone(struct send_ctx *sctx,
|
|
u64 offset, u32 len,
|
|
struct clone_root *clone_root)
|
|
{
|
|
int ret = 0;
|
|
struct fs_path *p;
|
|
u64 gen;
|
|
|
|
btrfs_debug(sctx->send_root->fs_info,
|
|
"send_clone offset=%llu, len=%d, clone_root=%llu, clone_inode=%llu, clone_offset=%llu",
|
|
offset, len, clone_root->root->root_key.objectid,
|
|
clone_root->ino, clone_root->offset);
|
|
|
|
p = fs_path_alloc();
|
|
if (!p)
|
|
return -ENOMEM;
|
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_CLONE);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_LEN, len);
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
|
|
|
|
if (clone_root->root == sctx->send_root) {
|
|
ret = get_inode_info(sctx->send_root, clone_root->ino, NULL,
|
|
&gen, NULL, NULL, NULL, NULL);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = get_cur_path(sctx, clone_root->ino, gen, p);
|
|
} else {
|
|
ret = get_inode_path(clone_root->root, clone_root->ino, p);
|
|
}
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
/*
|
|
* If the parent we're using has a received_uuid set then use that as
|
|
* our clone source as that is what we will look for when doing a
|
|
* receive.
|
|
*
|
|
* This covers the case that we create a snapshot off of a received
|
|
* subvolume and then use that as the parent and try to receive on a
|
|
* different host.
|
|
*/
|
|
if (!btrfs_is_empty_uuid(clone_root->root->root_item.received_uuid))
|
|
TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
|
|
clone_root->root->root_item.received_uuid);
|
|
else
|
|
TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
|
|
clone_root->root->root_item.uuid);
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
|
|
btrfs_root_ctransid(&clone_root->root->root_item));
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_CLONE_PATH, p);
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_OFFSET,
|
|
clone_root->offset);
|
|
|
|
ret = send_cmd(sctx);
|
|
|
|
tlv_put_failure:
|
|
out:
|
|
fs_path_free(p);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Send an update extent command to user space.
|
|
*/
|
|
static int send_update_extent(struct send_ctx *sctx,
|
|
u64 offset, u32 len)
|
|
{
|
|
int ret = 0;
|
|
struct fs_path *p;
|
|
|
|
p = fs_path_alloc();
|
|
if (!p)
|
|
return -ENOMEM;
|
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_UPDATE_EXTENT);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, len);
|
|
|
|
ret = send_cmd(sctx);
|
|
|
|
tlv_put_failure:
|
|
out:
|
|
fs_path_free(p);
|
|
return ret;
|
|
}
|
|
|
|
static int send_hole(struct send_ctx *sctx, u64 end)
|
|
{
|
|
struct fs_path *p = NULL;
|
|
u64 read_size = max_send_read_size(sctx);
|
|
u64 offset = sctx->cur_inode_last_extent;
|
|
int ret = 0;
|
|
|
|
/*
|
|
* A hole that starts at EOF or beyond it. Since we do not yet support
|
|
* fallocate (for extent preallocation and hole punching), sending a
|
|
* write of zeroes starting at EOF or beyond would later require issuing
|
|
* a truncate operation which would undo the write and achieve nothing.
|
|
*/
|
|
if (offset >= sctx->cur_inode_size)
|
|
return 0;
|
|
|
|
/*
|
|
* Don't go beyond the inode's i_size due to prealloc extents that start
|
|
* after the i_size.
|
|
*/
|
|
end = min_t(u64, end, sctx->cur_inode_size);
|
|
|
|
if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA)
|
|
return send_update_extent(sctx, offset, end - offset);
|
|
|
|
p = fs_path_alloc();
|
|
if (!p)
|
|
return -ENOMEM;
|
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
|
|
if (ret < 0)
|
|
goto tlv_put_failure;
|
|
while (offset < end) {
|
|
u64 len = min(end - offset, read_size);
|
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE);
|
|
if (ret < 0)
|
|
break;
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
|
|
ret = put_data_header(sctx, len);
|
|
if (ret < 0)
|
|
break;
|
|
memset(sctx->send_buf + sctx->send_size, 0, len);
|
|
sctx->send_size += len;
|
|
ret = send_cmd(sctx);
|
|
if (ret < 0)
|
|
break;
|
|
offset += len;
|
|
}
|
|
sctx->cur_inode_next_write_offset = offset;
|
|
tlv_put_failure:
|
|
fs_path_free(p);
|
|
return ret;
|
|
}
|
|
|
|
static int send_extent_data(struct send_ctx *sctx,
|
|
const u64 offset,
|
|
const u64 len)
|
|
{
|
|
const u64 end = offset + len;
|
|
u64 read_size = max_send_read_size(sctx);
|
|
u64 sent = 0;
|
|
|
|
if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA)
|
|
return send_update_extent(sctx, offset, len);
|
|
|
|
if (sctx->cur_inode == NULL) {
|
|
struct btrfs_root *root = sctx->send_root;
|
|
|
|
sctx->cur_inode = btrfs_iget(root->fs_info->sb, sctx->cur_ino, root);
|
|
if (IS_ERR(sctx->cur_inode)) {
|
|
int err = PTR_ERR(sctx->cur_inode);
|
|
|
|
sctx->cur_inode = NULL;
|
|
return err;
|
|
}
|
|
memset(&sctx->ra, 0, sizeof(struct file_ra_state));
|
|
file_ra_state_init(&sctx->ra, sctx->cur_inode->i_mapping);
|
|
|
|
/*
|
|
* It's very likely there are no pages from this inode in the page
|
|
* cache, so after reading extents and sending their data, we clean
|
|
* the page cache to avoid trashing the page cache (adding pressure
|
|
* to the page cache and forcing eviction of other data more useful
|
|
* for applications).
|
|
*
|
|
* We decide if we should clean the page cache simply by checking
|
|
* if the inode's mapping nrpages is 0 when we first open it, and
|
|
* not by using something like filemap_range_has_page() before
|
|
* reading an extent because when we ask the readahead code to
|
|
* read a given file range, it may (and almost always does) read
|
|
* pages from beyond that range (see the documentation for
|
|
* page_cache_sync_readahead()), so it would not be reliable,
|
|
* because after reading the first extent future calls to
|
|
* filemap_range_has_page() would return true because the readahead
|
|
* on the previous extent resulted in reading pages of the current
|
|
* extent as well.
|
|
*/
|
|
sctx->clean_page_cache = (sctx->cur_inode->i_mapping->nrpages == 0);
|
|
sctx->page_cache_clear_start = round_down(offset, PAGE_SIZE);
|
|
}
|
|
|
|
while (sent < len) {
|
|
u64 size = min(len - sent, read_size);
|
|
int ret;
|
|
|
|
ret = send_write(sctx, offset + sent, size);
|
|
if (ret < 0)
|
|
return ret;
|
|
sent += size;
|
|
}
|
|
|
|
if (sctx->clean_page_cache && IS_ALIGNED(end, PAGE_SIZE)) {
|
|
/*
|
|
* Always operate only on ranges that are a multiple of the page
|
|
* size. This is not only to prevent zeroing parts of a page in
|
|
* the case of subpage sector size, but also to guarantee we evict
|
|
* pages, as passing a range that is smaller than page size does
|
|
* not evict the respective page (only zeroes part of its content).
|
|
*
|
|
* Always start from the end offset of the last range cleared.
|
|
* This is because the readahead code may (and very often does)
|
|
* reads pages beyond the range we request for readahead. So if
|
|
* we have an extent layout like this:
|
|
*
|
|
* [ extent A ] [ extent B ] [ extent C ]
|
|
*
|
|
* When we ask page_cache_sync_readahead() to read extent A, it
|
|
* may also trigger reads for pages of extent B. If we are doing
|
|
* an incremental send and extent B has not changed between the
|
|
* parent and send snapshots, some or all of its pages may end
|
|
* up being read and placed in the page cache. So when truncating
|
|
* the page cache we always start from the end offset of the
|
|
* previously processed extent up to the end of the current
|
|
* extent.
|
|
*/
|
|
truncate_inode_pages_range(&sctx->cur_inode->i_data,
|
|
sctx->page_cache_clear_start,
|
|
end - 1);
|
|
sctx->page_cache_clear_start = end;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Search for a capability xattr related to sctx->cur_ino. If the capability is
|
|
* found, call send_set_xattr function to emit it.
|
|
*
|
|
* Return 0 if there isn't a capability, or when the capability was emitted
|
|
* successfully, or < 0 if an error occurred.
|
|
*/
|
|
static int send_capabilities(struct send_ctx *sctx)
|
|
{
|
|
struct fs_path *fspath = NULL;
|
|
struct btrfs_path *path;
|
|
struct btrfs_dir_item *di;
|
|
struct extent_buffer *leaf;
|
|
unsigned long data_ptr;
|
|
char *buf = NULL;
|
|
int buf_len;
|
|
int ret = 0;
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
di = btrfs_lookup_xattr(NULL, sctx->send_root, path, sctx->cur_ino,
|
|
XATTR_NAME_CAPS, strlen(XATTR_NAME_CAPS), 0);
|
|
if (!di) {
|
|
/* There is no xattr for this inode */
|
|
goto out;
|
|
} else if (IS_ERR(di)) {
|
|
ret = PTR_ERR(di);
|
|
goto out;
|
|
}
|
|
|
|
leaf = path->nodes[0];
|
|
buf_len = btrfs_dir_data_len(leaf, di);
|
|
|
|
fspath = fs_path_alloc();
|
|
buf = kmalloc(buf_len, GFP_KERNEL);
|
|
if (!fspath || !buf) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, fspath);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
data_ptr = (unsigned long)(di + 1) + btrfs_dir_name_len(leaf, di);
|
|
read_extent_buffer(leaf, buf, data_ptr, buf_len);
|
|
|
|
ret = send_set_xattr(sctx, fspath, XATTR_NAME_CAPS,
|
|
strlen(XATTR_NAME_CAPS), buf, buf_len);
|
|
out:
|
|
kfree(buf);
|
|
fs_path_free(fspath);
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
static int clone_range(struct send_ctx *sctx,
|
|
struct clone_root *clone_root,
|
|
const u64 disk_byte,
|
|
u64 data_offset,
|
|
u64 offset,
|
|
u64 len)
|
|
{
|
|
struct btrfs_path *path;
|
|
struct btrfs_key key;
|
|
int ret;
|
|
u64 clone_src_i_size = 0;
|
|
|
|
/*
|
|
* Prevent cloning from a zero offset with a length matching the sector
|
|
* size because in some scenarios this will make the receiver fail.
|
|
*
|
|
* For example, if in the source filesystem the extent at offset 0
|
|
* has a length of sectorsize and it was written using direct IO, then
|
|
* it can never be an inline extent (even if compression is enabled).
|
|
* Then this extent can be cloned in the original filesystem to a non
|
|
* zero file offset, but it may not be possible to clone in the
|
|
* destination filesystem because it can be inlined due to compression
|
|
* on the destination filesystem (as the receiver's write operations are
|
|
* always done using buffered IO). The same happens when the original
|
|
* filesystem does not have compression enabled but the destination
|
|
* filesystem has.
|
|
*/
|
|
if (clone_root->offset == 0 &&
|
|
len == sctx->send_root->fs_info->sectorsize)
|
|
return send_extent_data(sctx, offset, len);
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
/*
|
|
* There are inodes that have extents that lie behind its i_size. Don't
|
|
* accept clones from these extents.
|
|
*/
|
|
ret = __get_inode_info(clone_root->root, path, clone_root->ino,
|
|
&clone_src_i_size, NULL, NULL, NULL, NULL, NULL);
|
|
btrfs_release_path(path);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
/*
|
|
* We can't send a clone operation for the entire range if we find
|
|
* extent items in the respective range in the source file that
|
|
* refer to different extents or if we find holes.
|
|
* So check for that and do a mix of clone and regular write/copy
|
|
* operations if needed.
|
|
*
|
|
* Example:
|
|
*
|
|
* mkfs.btrfs -f /dev/sda
|
|
* mount /dev/sda /mnt
|
|
* xfs_io -f -c "pwrite -S 0xaa 0K 100K" /mnt/foo
|
|
* cp --reflink=always /mnt/foo /mnt/bar
|
|
* xfs_io -c "pwrite -S 0xbb 50K 50K" /mnt/foo
|
|
* btrfs subvolume snapshot -r /mnt /mnt/snap
|
|
*
|
|
* If when we send the snapshot and we are processing file bar (which
|
|
* has a higher inode number than foo) we blindly send a clone operation
|
|
* for the [0, 100K[ range from foo to bar, the receiver ends up getting
|
|
* a file bar that matches the content of file foo - iow, doesn't match
|
|
* the content from bar in the original filesystem.
|
|
*/
|
|
key.objectid = clone_root->ino;
|
|
key.type = BTRFS_EXTENT_DATA_KEY;
|
|
key.offset = clone_root->offset;
|
|
ret = btrfs_search_slot(NULL, clone_root->root, &key, path, 0, 0);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret > 0 && path->slots[0] > 0) {
|
|
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0] - 1);
|
|
if (key.objectid == clone_root->ino &&
|
|
key.type == BTRFS_EXTENT_DATA_KEY)
|
|
path->slots[0]--;
|
|
}
|
|
|
|
while (true) {
|
|
struct extent_buffer *leaf = path->nodes[0];
|
|
int slot = path->slots[0];
|
|
struct btrfs_file_extent_item *ei;
|
|
u8 type;
|
|
u64 ext_len;
|
|
u64 clone_len;
|
|
u64 clone_data_offset;
|
|
|
|
if (slot >= btrfs_header_nritems(leaf)) {
|
|
ret = btrfs_next_leaf(clone_root->root, path);
|
|
if (ret < 0)
|
|
goto out;
|
|
else if (ret > 0)
|
|
break;
|
|
continue;
|
|
}
|
|
|
|
btrfs_item_key_to_cpu(leaf, &key, slot);
|
|
|
|
/*
|
|
* We might have an implicit trailing hole (NO_HOLES feature
|
|
* enabled). We deal with it after leaving this loop.
|
|
*/
|
|
if (key.objectid != clone_root->ino ||
|
|
key.type != BTRFS_EXTENT_DATA_KEY)
|
|
break;
|
|
|
|
ei = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
|
|
type = btrfs_file_extent_type(leaf, ei);
|
|
if (type == BTRFS_FILE_EXTENT_INLINE) {
|
|
ext_len = btrfs_file_extent_ram_bytes(leaf, ei);
|
|
ext_len = PAGE_ALIGN(ext_len);
|
|
} else {
|
|
ext_len = btrfs_file_extent_num_bytes(leaf, ei);
|
|
}
|
|
|
|
if (key.offset + ext_len <= clone_root->offset)
|
|
goto next;
|
|
|
|
if (key.offset > clone_root->offset) {
|
|
/* Implicit hole, NO_HOLES feature enabled. */
|
|
u64 hole_len = key.offset - clone_root->offset;
|
|
|
|
if (hole_len > len)
|
|
hole_len = len;
|
|
ret = send_extent_data(sctx, offset, hole_len);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
len -= hole_len;
|
|
if (len == 0)
|
|
break;
|
|
offset += hole_len;
|
|
clone_root->offset += hole_len;
|
|
data_offset += hole_len;
|
|
}
|
|
|
|
if (key.offset >= clone_root->offset + len)
|
|
break;
|
|
|
|
if (key.offset >= clone_src_i_size)
|
|
break;
|
|
|
|
if (key.offset + ext_len > clone_src_i_size)
|
|
ext_len = clone_src_i_size - key.offset;
|
|
|
|
clone_data_offset = btrfs_file_extent_offset(leaf, ei);
|
|
if (btrfs_file_extent_disk_bytenr(leaf, ei) == disk_byte) {
|
|
clone_root->offset = key.offset;
|
|
if (clone_data_offset < data_offset &&
|
|
clone_data_offset + ext_len > data_offset) {
|
|
u64 extent_offset;
|
|
|
|
extent_offset = data_offset - clone_data_offset;
|
|
ext_len -= extent_offset;
|
|
clone_data_offset += extent_offset;
|
|
clone_root->offset += extent_offset;
|
|
}
|
|
}
|
|
|
|
clone_len = min_t(u64, ext_len, len);
|
|
|
|
if (btrfs_file_extent_disk_bytenr(leaf, ei) == disk_byte &&
|
|
clone_data_offset == data_offset) {
|
|
const u64 src_end = clone_root->offset + clone_len;
|
|
const u64 sectorsize = SZ_64K;
|
|
|
|
/*
|
|
* We can't clone the last block, when its size is not
|
|
* sector size aligned, into the middle of a file. If we
|
|
* do so, the receiver will get a failure (-EINVAL) when
|
|
* trying to clone or will silently corrupt the data in
|
|
* the destination file if it's on a kernel without the
|
|
* fix introduced by commit ac765f83f1397646
|
|
* ("Btrfs: fix data corruption due to cloning of eof
|
|
* block).
|
|
*
|
|
* So issue a clone of the aligned down range plus a
|
|
* regular write for the eof block, if we hit that case.
|
|
*
|
|
* Also, we use the maximum possible sector size, 64K,
|
|
* because we don't know what's the sector size of the
|
|
* filesystem that receives the stream, so we have to
|
|
* assume the largest possible sector size.
|
|
*/
|
|
if (src_end == clone_src_i_size &&
|
|
!IS_ALIGNED(src_end, sectorsize) &&
|
|
offset + clone_len < sctx->cur_inode_size) {
|
|
u64 slen;
|
|
|
|
slen = ALIGN_DOWN(src_end - clone_root->offset,
|
|
sectorsize);
|
|
if (slen > 0) {
|
|
ret = send_clone(sctx, offset, slen,
|
|
clone_root);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
ret = send_extent_data(sctx, offset + slen,
|
|
clone_len - slen);
|
|
} else {
|
|
ret = send_clone(sctx, offset, clone_len,
|
|
clone_root);
|
|
}
|
|
} else {
|
|
ret = send_extent_data(sctx, offset, clone_len);
|
|
}
|
|
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
len -= clone_len;
|
|
if (len == 0)
|
|
break;
|
|
offset += clone_len;
|
|
clone_root->offset += clone_len;
|
|
|
|
/*
|
|
* If we are cloning from the file we are currently processing,
|
|
* and using the send root as the clone root, we must stop once
|
|
* the current clone offset reaches the current eof of the file
|
|
* at the receiver, otherwise we would issue an invalid clone
|
|
* operation (source range going beyond eof) and cause the
|
|
* receiver to fail. So if we reach the current eof, bail out
|
|
* and fallback to a regular write.
|
|
*/
|
|
if (clone_root->root == sctx->send_root &&
|
|
clone_root->ino == sctx->cur_ino &&
|
|
clone_root->offset >= sctx->cur_inode_next_write_offset)
|
|
break;
|
|
|
|
data_offset += clone_len;
|
|
next:
|
|
path->slots[0]++;
|
|
}
|
|
|
|
if (len > 0)
|
|
ret = send_extent_data(sctx, offset, len);
|
|
else
|
|
ret = 0;
|
|
out:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
static int send_write_or_clone(struct send_ctx *sctx,
|
|
struct btrfs_path *path,
|
|
struct btrfs_key *key,
|
|
struct clone_root *clone_root)
|
|
{
|
|
int ret = 0;
|
|
u64 offset = key->offset;
|
|
u64 end;
|
|
u64 bs = sctx->send_root->fs_info->sb->s_blocksize;
|
|
|
|
end = min_t(u64, btrfs_file_extent_end(path), sctx->cur_inode_size);
|
|
if (offset >= end)
|
|
return 0;
|
|
|
|
if (clone_root && IS_ALIGNED(end, bs)) {
|
|
struct btrfs_file_extent_item *ei;
|
|
u64 disk_byte;
|
|
u64 data_offset;
|
|
|
|
ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
|
|
struct btrfs_file_extent_item);
|
|
disk_byte = btrfs_file_extent_disk_bytenr(path->nodes[0], ei);
|
|
data_offset = btrfs_file_extent_offset(path->nodes[0], ei);
|
|
ret = clone_range(sctx, clone_root, disk_byte, data_offset,
|
|
offset, end - offset);
|
|
} else {
|
|
ret = send_extent_data(sctx, offset, end - offset);
|
|
}
|
|
sctx->cur_inode_next_write_offset = end;
|
|
return ret;
|
|
}
|
|
|
|
static int is_extent_unchanged(struct send_ctx *sctx,
|
|
struct btrfs_path *left_path,
|
|
struct btrfs_key *ekey)
|
|
{
|
|
int ret = 0;
|
|
struct btrfs_key key;
|
|
struct btrfs_path *path = NULL;
|
|
struct extent_buffer *eb;
|
|
int slot;
|
|
struct btrfs_key found_key;
|
|
struct btrfs_file_extent_item *ei;
|
|
u64 left_disknr;
|
|
u64 right_disknr;
|
|
u64 left_offset;
|
|
u64 right_offset;
|
|
u64 left_offset_fixed;
|
|
u64 left_len;
|
|
u64 right_len;
|
|
u64 left_gen;
|
|
u64 right_gen;
|
|
u8 left_type;
|
|
u8 right_type;
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
eb = left_path->nodes[0];
|
|
slot = left_path->slots[0];
|
|
ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
|
|
left_type = btrfs_file_extent_type(eb, ei);
|
|
|
|
if (left_type != BTRFS_FILE_EXTENT_REG) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
left_disknr = btrfs_file_extent_disk_bytenr(eb, ei);
|
|
left_len = btrfs_file_extent_num_bytes(eb, ei);
|
|
left_offset = btrfs_file_extent_offset(eb, ei);
|
|
left_gen = btrfs_file_extent_generation(eb, ei);
|
|
|
|
/*
|
|
* Following comments will refer to these graphics. L is the left
|
|
* extents which we are checking at the moment. 1-8 are the right
|
|
* extents that we iterate.
|
|
*
|
|
* |-----L-----|
|
|
* |-1-|-2a-|-3-|-4-|-5-|-6-|
|
|
*
|
|
* |-----L-----|
|
|
* |--1--|-2b-|...(same as above)
|
|
*
|
|
* Alternative situation. Happens on files where extents got split.
|
|
* |-----L-----|
|
|
* |-----------7-----------|-6-|
|
|
*
|
|
* Alternative situation. Happens on files which got larger.
|
|
* |-----L-----|
|
|
* |-8-|
|
|
* Nothing follows after 8.
|
|
*/
|
|
|
|
key.objectid = ekey->objectid;
|
|
key.type = BTRFS_EXTENT_DATA_KEY;
|
|
key.offset = ekey->offset;
|
|
ret = btrfs_search_slot_for_read(sctx->parent_root, &key, path, 0, 0);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Handle special case where the right side has no extents at all.
|
|
*/
|
|
eb = path->nodes[0];
|
|
slot = path->slots[0];
|
|
btrfs_item_key_to_cpu(eb, &found_key, slot);
|
|
if (found_key.objectid != key.objectid ||
|
|
found_key.type != key.type) {
|
|
/* If we're a hole then just pretend nothing changed */
|
|
ret = (left_disknr) ? 0 : 1;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* We're now on 2a, 2b or 7.
|
|
*/
|
|
key = found_key;
|
|
while (key.offset < ekey->offset + left_len) {
|
|
ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
|
|
right_type = btrfs_file_extent_type(eb, ei);
|
|
if (right_type != BTRFS_FILE_EXTENT_REG &&
|
|
right_type != BTRFS_FILE_EXTENT_INLINE) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
if (right_type == BTRFS_FILE_EXTENT_INLINE) {
|
|
right_len = btrfs_file_extent_ram_bytes(eb, ei);
|
|
right_len = PAGE_ALIGN(right_len);
|
|
} else {
|
|
right_len = btrfs_file_extent_num_bytes(eb, ei);
|
|
}
|
|
|
|
/*
|
|
* Are we at extent 8? If yes, we know the extent is changed.
|
|
* This may only happen on the first iteration.
|
|
*/
|
|
if (found_key.offset + right_len <= ekey->offset) {
|
|
/* If we're a hole just pretend nothing changed */
|
|
ret = (left_disknr) ? 0 : 1;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* We just wanted to see if when we have an inline extent, what
|
|
* follows it is a regular extent (wanted to check the above
|
|
* condition for inline extents too). This should normally not
|
|
* happen but it's possible for example when we have an inline
|
|
* compressed extent representing data with a size matching
|
|
* the page size (currently the same as sector size).
|
|
*/
|
|
if (right_type == BTRFS_FILE_EXTENT_INLINE) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
right_disknr = btrfs_file_extent_disk_bytenr(eb, ei);
|
|
right_offset = btrfs_file_extent_offset(eb, ei);
|
|
right_gen = btrfs_file_extent_generation(eb, ei);
|
|
|
|
left_offset_fixed = left_offset;
|
|
if (key.offset < ekey->offset) {
|
|
/* Fix the right offset for 2a and 7. */
|
|
right_offset += ekey->offset - key.offset;
|
|
} else {
|
|
/* Fix the left offset for all behind 2a and 2b */
|
|
left_offset_fixed += key.offset - ekey->offset;
|
|
}
|
|
|
|
/*
|
|
* Check if we have the same extent.
|
|
*/
|
|
if (left_disknr != right_disknr ||
|
|
left_offset_fixed != right_offset ||
|
|
left_gen != right_gen) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Go to the next extent.
|
|
*/
|
|
ret = btrfs_next_item(sctx->parent_root, path);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (!ret) {
|
|
eb = path->nodes[0];
|
|
slot = path->slots[0];
|
|
btrfs_item_key_to_cpu(eb, &found_key, slot);
|
|
}
|
|
if (ret || found_key.objectid != key.objectid ||
|
|
found_key.type != key.type) {
|
|
key.offset += right_len;
|
|
break;
|
|
}
|
|
if (found_key.offset != key.offset + right_len) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
key = found_key;
|
|
}
|
|
|
|
/*
|
|
* We're now behind the left extent (treat as unchanged) or at the end
|
|
* of the right side (treat as changed).
|
|
*/
|
|
if (key.offset >= ekey->offset + left_len)
|
|
ret = 1;
|
|
else
|
|
ret = 0;
|
|
|
|
|
|
out:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
static int get_last_extent(struct send_ctx *sctx, u64 offset)
|
|
{
|
|
struct btrfs_path *path;
|
|
struct btrfs_root *root = sctx->send_root;
|
|
struct btrfs_key key;
|
|
int ret;
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
sctx->cur_inode_last_extent = 0;
|
|
|
|
key.objectid = sctx->cur_ino;
|
|
key.type = BTRFS_EXTENT_DATA_KEY;
|
|
key.offset = offset;
|
|
ret = btrfs_search_slot_for_read(root, &key, path, 0, 1);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = 0;
|
|
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
|
|
if (key.objectid != sctx->cur_ino || key.type != BTRFS_EXTENT_DATA_KEY)
|
|
goto out;
|
|
|
|
sctx->cur_inode_last_extent = btrfs_file_extent_end(path);
|
|
out:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
static int range_is_hole_in_parent(struct send_ctx *sctx,
|
|
const u64 start,
|
|
const u64 end)
|
|
{
|
|
struct btrfs_path *path;
|
|
struct btrfs_key key;
|
|
struct btrfs_root *root = sctx->parent_root;
|
|
u64 search_start = start;
|
|
int ret;
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
key.objectid = sctx->cur_ino;
|
|
key.type = BTRFS_EXTENT_DATA_KEY;
|
|
key.offset = search_start;
|
|
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret > 0 && path->slots[0] > 0)
|
|
path->slots[0]--;
|
|
|
|
while (search_start < end) {
|
|
struct extent_buffer *leaf = path->nodes[0];
|
|
int slot = path->slots[0];
|
|
struct btrfs_file_extent_item *fi;
|
|
u64 extent_end;
|
|
|
|
if (slot >= btrfs_header_nritems(leaf)) {
|
|
ret = btrfs_next_leaf(root, path);
|
|
if (ret < 0)
|
|
goto out;
|
|
else if (ret > 0)
|
|
break;
|
|
continue;
|
|
}
|
|
|
|
btrfs_item_key_to_cpu(leaf, &key, slot);
|
|
if (key.objectid < sctx->cur_ino ||
|
|
key.type < BTRFS_EXTENT_DATA_KEY)
|
|
goto next;
|
|
if (key.objectid > sctx->cur_ino ||
|
|
key.type > BTRFS_EXTENT_DATA_KEY ||
|
|
key.offset >= end)
|
|
break;
|
|
|
|
fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
|
|
extent_end = btrfs_file_extent_end(path);
|
|
if (extent_end <= start)
|
|
goto next;
|
|
if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0) {
|
|
search_start = extent_end;
|
|
goto next;
|
|
}
|
|
ret = 0;
|
|
goto out;
|
|
next:
|
|
path->slots[0]++;
|
|
}
|
|
ret = 1;
|
|
out:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
static int maybe_send_hole(struct send_ctx *sctx, struct btrfs_path *path,
|
|
struct btrfs_key *key)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (sctx->cur_ino != key->objectid || !need_send_hole(sctx))
|
|
return 0;
|
|
|
|
if (sctx->cur_inode_last_extent == (u64)-1) {
|
|
ret = get_last_extent(sctx, key->offset - 1);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
if (path->slots[0] == 0 &&
|
|
sctx->cur_inode_last_extent < key->offset) {
|
|
/*
|
|
* We might have skipped entire leafs that contained only
|
|
* file extent items for our current inode. These leafs have
|
|
* a generation number smaller (older) than the one in the
|
|
* current leaf and the leaf our last extent came from, and
|
|
* are located between these 2 leafs.
|
|
*/
|
|
ret = get_last_extent(sctx, key->offset - 1);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
if (sctx->cur_inode_last_extent < key->offset) {
|
|
ret = range_is_hole_in_parent(sctx,
|
|
sctx->cur_inode_last_extent,
|
|
key->offset);
|
|
if (ret < 0)
|
|
return ret;
|
|
else if (ret == 0)
|
|
ret = send_hole(sctx, key->offset);
|
|
else
|
|
ret = 0;
|
|
}
|
|
sctx->cur_inode_last_extent = btrfs_file_extent_end(path);
|
|
return ret;
|
|
}
|
|
|
|
static int process_extent(struct send_ctx *sctx,
|
|
struct btrfs_path *path,
|
|
struct btrfs_key *key)
|
|
{
|
|
struct clone_root *found_clone = NULL;
|
|
int ret = 0;
|
|
|
|
if (S_ISLNK(sctx->cur_inode_mode))
|
|
return 0;
|
|
|
|
if (sctx->parent_root && !sctx->cur_inode_new) {
|
|
ret = is_extent_unchanged(sctx, path, key);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret) {
|
|
ret = 0;
|
|
goto out_hole;
|
|
}
|
|
} else {
|
|
struct btrfs_file_extent_item *ei;
|
|
u8 type;
|
|
|
|
ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
|
|
struct btrfs_file_extent_item);
|
|
type = btrfs_file_extent_type(path->nodes[0], ei);
|
|
if (type == BTRFS_FILE_EXTENT_PREALLOC ||
|
|
type == BTRFS_FILE_EXTENT_REG) {
|
|
/*
|
|
* The send spec does not have a prealloc command yet,
|
|
* so just leave a hole for prealloc'ed extents until
|
|
* we have enough commands queued up to justify rev'ing
|
|
* the send spec.
|
|
*/
|
|
if (type == BTRFS_FILE_EXTENT_PREALLOC) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
/* Have a hole, just skip it. */
|
|
if (btrfs_file_extent_disk_bytenr(path->nodes[0], ei) == 0) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
}
|
|
}
|
|
|
|
ret = find_extent_clone(sctx, path, key->objectid, key->offset,
|
|
sctx->cur_inode_size, &found_clone);
|
|
if (ret != -ENOENT && ret < 0)
|
|
goto out;
|
|
|
|
ret = send_write_or_clone(sctx, path, key, found_clone);
|
|
if (ret)
|
|
goto out;
|
|
out_hole:
|
|
ret = maybe_send_hole(sctx, path, key);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int process_all_extents(struct send_ctx *sctx)
|
|
{
|
|
int ret = 0;
|
|
int iter_ret = 0;
|
|
struct btrfs_root *root;
|
|
struct btrfs_path *path;
|
|
struct btrfs_key key;
|
|
struct btrfs_key found_key;
|
|
|
|
root = sctx->send_root;
|
|
path = alloc_path_for_send();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
key.objectid = sctx->cmp_key->objectid;
|
|
key.type = BTRFS_EXTENT_DATA_KEY;
|
|
key.offset = 0;
|
|
btrfs_for_each_slot(root, &key, &found_key, path, iter_ret) {
|
|
if (found_key.objectid != key.objectid ||
|
|
found_key.type != key.type) {
|
|
ret = 0;
|
|
break;
|
|
}
|
|
|
|
ret = process_extent(sctx, path, &found_key);
|
|
if (ret < 0)
|
|
break;
|
|
}
|
|
/* Catch error found during iteration */
|
|
if (iter_ret < 0)
|
|
ret = iter_ret;
|
|
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
static int process_recorded_refs_if_needed(struct send_ctx *sctx, int at_end,
|
|
int *pending_move,
|
|
int *refs_processed)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (sctx->cur_ino == 0)
|
|
goto out;
|
|
if (!at_end && sctx->cur_ino == sctx->cmp_key->objectid &&
|
|
sctx->cmp_key->type <= BTRFS_INODE_EXTREF_KEY)
|
|
goto out;
|
|
if (list_empty(&sctx->new_refs) && list_empty(&sctx->deleted_refs))
|
|
goto out;
|
|
|
|
ret = process_recorded_refs(sctx, pending_move);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
*refs_processed = 1;
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int finish_inode_if_needed(struct send_ctx *sctx, int at_end)
|
|
{
|
|
int ret = 0;
|
|
u64 left_mode;
|
|
u64 left_uid;
|
|
u64 left_gid;
|
|
u64 right_mode;
|
|
u64 right_uid;
|
|
u64 right_gid;
|
|
int need_chmod = 0;
|
|
int need_chown = 0;
|
|
int need_truncate = 1;
|
|
int pending_move = 0;
|
|
int refs_processed = 0;
|
|
|
|
if (sctx->ignore_cur_inode)
|
|
return 0;
|
|
|
|
ret = process_recorded_refs_if_needed(sctx, at_end, &pending_move,
|
|
&refs_processed);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
/*
|
|
* We have processed the refs and thus need to advance send_progress.
|
|
* Now, calls to get_cur_xxx will take the updated refs of the current
|
|
* inode into account.
|
|
*
|
|
* On the other hand, if our current inode is a directory and couldn't
|
|
* be moved/renamed because its parent was renamed/moved too and it has
|
|
* a higher inode number, we can only move/rename our current inode
|
|
* after we moved/renamed its parent. Therefore in this case operate on
|
|
* the old path (pre move/rename) of our current inode, and the
|
|
* move/rename will be performed later.
|
|
*/
|
|
if (refs_processed && !pending_move)
|
|
sctx->send_progress = sctx->cur_ino + 1;
|
|
|
|
if (sctx->cur_ino == 0 || sctx->cur_inode_deleted)
|
|
goto out;
|
|
if (!at_end && sctx->cmp_key->objectid == sctx->cur_ino)
|
|
goto out;
|
|
|
|
ret = get_inode_info(sctx->send_root, sctx->cur_ino, NULL, NULL,
|
|
&left_mode, &left_uid, &left_gid, NULL);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
if (!sctx->parent_root || sctx->cur_inode_new) {
|
|
need_chown = 1;
|
|
if (!S_ISLNK(sctx->cur_inode_mode))
|
|
need_chmod = 1;
|
|
if (sctx->cur_inode_next_write_offset == sctx->cur_inode_size)
|
|
need_truncate = 0;
|
|
} else {
|
|
u64 old_size;
|
|
|
|
ret = get_inode_info(sctx->parent_root, sctx->cur_ino,
|
|
&old_size, NULL, &right_mode, &right_uid,
|
|
&right_gid, NULL);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
if (left_uid != right_uid || left_gid != right_gid)
|
|
need_chown = 1;
|
|
if (!S_ISLNK(sctx->cur_inode_mode) && left_mode != right_mode)
|
|
need_chmod = 1;
|
|
if ((old_size == sctx->cur_inode_size) ||
|
|
(sctx->cur_inode_size > old_size &&
|
|
sctx->cur_inode_next_write_offset == sctx->cur_inode_size))
|
|
need_truncate = 0;
|
|
}
|
|
|
|
if (S_ISREG(sctx->cur_inode_mode)) {
|
|
if (need_send_hole(sctx)) {
|
|
if (sctx->cur_inode_last_extent == (u64)-1 ||
|
|
sctx->cur_inode_last_extent <
|
|
sctx->cur_inode_size) {
|
|
ret = get_last_extent(sctx, (u64)-1);
|
|
if (ret)
|
|
goto out;
|
|
}
|
|
if (sctx->cur_inode_last_extent <
|
|
sctx->cur_inode_size) {
|
|
ret = send_hole(sctx, sctx->cur_inode_size);
|
|
if (ret)
|
|
goto out;
|
|
}
|
|
}
|
|
if (need_truncate) {
|
|
ret = send_truncate(sctx, sctx->cur_ino,
|
|
sctx->cur_inode_gen,
|
|
sctx->cur_inode_size);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (need_chown) {
|
|
ret = send_chown(sctx, sctx->cur_ino, sctx->cur_inode_gen,
|
|
left_uid, left_gid);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
if (need_chmod) {
|
|
ret = send_chmod(sctx, sctx->cur_ino, sctx->cur_inode_gen,
|
|
left_mode);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
|
|
ret = send_capabilities(sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
/*
|
|
* If other directory inodes depended on our current directory
|
|
* inode's move/rename, now do their move/rename operations.
|
|
*/
|
|
if (!is_waiting_for_move(sctx, sctx->cur_ino)) {
|
|
ret = apply_children_dir_moves(sctx);
|
|
if (ret)
|
|
goto out;
|
|
/*
|
|
* Need to send that every time, no matter if it actually
|
|
* changed between the two trees as we have done changes to
|
|
* the inode before. If our inode is a directory and it's
|
|
* waiting to be moved/renamed, we will send its utimes when
|
|
* it's moved/renamed, therefore we don't need to do it here.
|
|
*/
|
|
sctx->send_progress = sctx->cur_ino + 1;
|
|
ret = send_utimes(sctx, sctx->cur_ino, sctx->cur_inode_gen);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
struct parent_paths_ctx {
|
|
struct list_head *refs;
|
|
struct send_ctx *sctx;
|
|
};
|
|
|
|
static int record_parent_ref(int num, u64 dir, int index, struct fs_path *name,
|
|
void *ctx)
|
|
{
|
|
struct parent_paths_ctx *ppctx = ctx;
|
|
|
|
return record_ref(ppctx->sctx->parent_root, dir, name, ppctx->sctx,
|
|
ppctx->refs);
|
|
}
|
|
|
|
/*
|
|
* Issue unlink operations for all paths of the current inode found in the
|
|
* parent snapshot.
|
|
*/
|
|
static int btrfs_unlink_all_paths(struct send_ctx *sctx)
|
|
{
|
|
LIST_HEAD(deleted_refs);
|
|
struct btrfs_path *path;
|
|
struct btrfs_root *root = sctx->parent_root;
|
|
struct btrfs_key key;
|
|
struct btrfs_key found_key;
|
|
struct parent_paths_ctx ctx;
|
|
int iter_ret = 0;
|
|
int ret;
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
key.objectid = sctx->cur_ino;
|
|
key.type = BTRFS_INODE_REF_KEY;
|
|
key.offset = 0;
|
|
|
|
ctx.refs = &deleted_refs;
|
|
ctx.sctx = sctx;
|
|
|
|
btrfs_for_each_slot(root, &key, &found_key, path, iter_ret) {
|
|
if (found_key.objectid != key.objectid)
|
|
break;
|
|
if (found_key.type != key.type &&
|
|
found_key.type != BTRFS_INODE_EXTREF_KEY)
|
|
break;
|
|
|
|
ret = iterate_inode_ref(root, path, &found_key, 1,
|
|
record_parent_ref, &ctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
/* Catch error found during iteration */
|
|
if (iter_ret < 0) {
|
|
ret = iter_ret;
|
|
goto out;
|
|
}
|
|
|
|
while (!list_empty(&deleted_refs)) {
|
|
struct recorded_ref *ref;
|
|
|
|
ref = list_first_entry(&deleted_refs, struct recorded_ref, list);
|
|
ret = send_unlink(sctx, ref->full_path);
|
|
if (ret < 0)
|
|
goto out;
|
|
fs_path_free(ref->full_path);
|
|
list_del(&ref->list);
|
|
kfree(ref);
|
|
}
|
|
ret = 0;
|
|
out:
|
|
btrfs_free_path(path);
|
|
if (ret)
|
|
__free_recorded_refs(&deleted_refs);
|
|
return ret;
|
|
}
|
|
|
|
static void close_current_inode(struct send_ctx *sctx)
|
|
{
|
|
u64 i_size;
|
|
|
|
if (sctx->cur_inode == NULL)
|
|
return;
|
|
|
|
i_size = i_size_read(sctx->cur_inode);
|
|
|
|
/*
|
|
* If we are doing an incremental send, we may have extents between the
|
|
* last processed extent and the i_size that have not been processed
|
|
* because they haven't changed but we may have read some of their pages
|
|
* through readahead, see the comments at send_extent_data().
|
|
*/
|
|
if (sctx->clean_page_cache && sctx->page_cache_clear_start < i_size)
|
|
truncate_inode_pages_range(&sctx->cur_inode->i_data,
|
|
sctx->page_cache_clear_start,
|
|
round_up(i_size, PAGE_SIZE) - 1);
|
|
|
|
iput(sctx->cur_inode);
|
|
sctx->cur_inode = NULL;
|
|
}
|
|
|
|
static int changed_inode(struct send_ctx *sctx,
|
|
enum btrfs_compare_tree_result result)
|
|
{
|
|
int ret = 0;
|
|
struct btrfs_key *key = sctx->cmp_key;
|
|
struct btrfs_inode_item *left_ii = NULL;
|
|
struct btrfs_inode_item *right_ii = NULL;
|
|
u64 left_gen = 0;
|
|
u64 right_gen = 0;
|
|
|
|
close_current_inode(sctx);
|
|
|
|
sctx->cur_ino = key->objectid;
|
|
sctx->cur_inode_new_gen = 0;
|
|
sctx->cur_inode_last_extent = (u64)-1;
|
|
sctx->cur_inode_next_write_offset = 0;
|
|
sctx->ignore_cur_inode = false;
|
|
|
|
/*
|
|
* Set send_progress to current inode. This will tell all get_cur_xxx
|
|
* functions that the current inode's refs are not updated yet. Later,
|
|
* when process_recorded_refs is finished, it is set to cur_ino + 1.
|
|
*/
|
|
sctx->send_progress = sctx->cur_ino;
|
|
|
|
if (result == BTRFS_COMPARE_TREE_NEW ||
|
|
result == BTRFS_COMPARE_TREE_CHANGED) {
|
|
left_ii = btrfs_item_ptr(sctx->left_path->nodes[0],
|
|
sctx->left_path->slots[0],
|
|
struct btrfs_inode_item);
|
|
left_gen = btrfs_inode_generation(sctx->left_path->nodes[0],
|
|
left_ii);
|
|
} else {
|
|
right_ii = btrfs_item_ptr(sctx->right_path->nodes[0],
|
|
sctx->right_path->slots[0],
|
|
struct btrfs_inode_item);
|
|
right_gen = btrfs_inode_generation(sctx->right_path->nodes[0],
|
|
right_ii);
|
|
}
|
|
if (result == BTRFS_COMPARE_TREE_CHANGED) {
|
|
right_ii = btrfs_item_ptr(sctx->right_path->nodes[0],
|
|
sctx->right_path->slots[0],
|
|
struct btrfs_inode_item);
|
|
|
|
right_gen = btrfs_inode_generation(sctx->right_path->nodes[0],
|
|
right_ii);
|
|
|
|
/*
|
|
* The cur_ino = root dir case is special here. We can't treat
|
|
* the inode as deleted+reused because it would generate a
|
|
* stream that tries to delete/mkdir the root dir.
|
|
*/
|
|
if (left_gen != right_gen &&
|
|
sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
|
|
sctx->cur_inode_new_gen = 1;
|
|
}
|
|
|
|
/*
|
|
* Normally we do not find inodes with a link count of zero (orphans)
|
|
* because the most common case is to create a snapshot and use it
|
|
* for a send operation. However other less common use cases involve
|
|
* using a subvolume and send it after turning it to RO mode just
|
|
* after deleting all hard links of a file while holding an open
|
|
* file descriptor against it or turning a RO snapshot into RW mode,
|
|
* keep an open file descriptor against a file, delete it and then
|
|
* turn the snapshot back to RO mode before using it for a send
|
|
* operation. So if we find such cases, ignore the inode and all its
|
|
* items completely if it's a new inode, or if it's a changed inode
|
|
* make sure all its previous paths (from the parent snapshot) are all
|
|
* unlinked and all other the inode items are ignored.
|
|
*/
|
|
if (result == BTRFS_COMPARE_TREE_NEW ||
|
|
result == BTRFS_COMPARE_TREE_CHANGED) {
|
|
u32 nlinks;
|
|
|
|
nlinks = btrfs_inode_nlink(sctx->left_path->nodes[0], left_ii);
|
|
if (nlinks == 0) {
|
|
sctx->ignore_cur_inode = true;
|
|
if (result == BTRFS_COMPARE_TREE_CHANGED)
|
|
ret = btrfs_unlink_all_paths(sctx);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (result == BTRFS_COMPARE_TREE_NEW) {
|
|
sctx->cur_inode_gen = left_gen;
|
|
sctx->cur_inode_new = 1;
|
|
sctx->cur_inode_deleted = 0;
|
|
sctx->cur_inode_size = btrfs_inode_size(
|
|
sctx->left_path->nodes[0], left_ii);
|
|
sctx->cur_inode_mode = btrfs_inode_mode(
|
|
sctx->left_path->nodes[0], left_ii);
|
|
sctx->cur_inode_rdev = btrfs_inode_rdev(
|
|
sctx->left_path->nodes[0], left_ii);
|
|
if (sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
|
|
ret = send_create_inode_if_needed(sctx);
|
|
} else if (result == BTRFS_COMPARE_TREE_DELETED) {
|
|
sctx->cur_inode_gen = right_gen;
|
|
sctx->cur_inode_new = 0;
|
|
sctx->cur_inode_deleted = 1;
|
|
sctx->cur_inode_size = btrfs_inode_size(
|
|
sctx->right_path->nodes[0], right_ii);
|
|
sctx->cur_inode_mode = btrfs_inode_mode(
|
|
sctx->right_path->nodes[0], right_ii);
|
|
} else if (result == BTRFS_COMPARE_TREE_CHANGED) {
|
|
/*
|
|
* We need to do some special handling in case the inode was
|
|
* reported as changed with a changed generation number. This
|
|
* means that the original inode was deleted and new inode
|
|
* reused the same inum. So we have to treat the old inode as
|
|
* deleted and the new one as new.
|
|
*/
|
|
if (sctx->cur_inode_new_gen) {
|
|
/*
|
|
* First, process the inode as if it was deleted.
|
|
*/
|
|
sctx->cur_inode_gen = right_gen;
|
|
sctx->cur_inode_new = 0;
|
|
sctx->cur_inode_deleted = 1;
|
|
sctx->cur_inode_size = btrfs_inode_size(
|
|
sctx->right_path->nodes[0], right_ii);
|
|
sctx->cur_inode_mode = btrfs_inode_mode(
|
|
sctx->right_path->nodes[0], right_ii);
|
|
ret = process_all_refs(sctx,
|
|
BTRFS_COMPARE_TREE_DELETED);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
/*
|
|
* Now process the inode as if it was new.
|
|
*/
|
|
sctx->cur_inode_gen = left_gen;
|
|
sctx->cur_inode_new = 1;
|
|
sctx->cur_inode_deleted = 0;
|
|
sctx->cur_inode_size = btrfs_inode_size(
|
|
sctx->left_path->nodes[0], left_ii);
|
|
sctx->cur_inode_mode = btrfs_inode_mode(
|
|
sctx->left_path->nodes[0], left_ii);
|
|
sctx->cur_inode_rdev = btrfs_inode_rdev(
|
|
sctx->left_path->nodes[0], left_ii);
|
|
ret = send_create_inode_if_needed(sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = process_all_refs(sctx, BTRFS_COMPARE_TREE_NEW);
|
|
if (ret < 0)
|
|
goto out;
|
|
/*
|
|
* Advance send_progress now as we did not get into
|
|
* process_recorded_refs_if_needed in the new_gen case.
|
|
*/
|
|
sctx->send_progress = sctx->cur_ino + 1;
|
|
|
|
/*
|
|
* Now process all extents and xattrs of the inode as if
|
|
* they were all new.
|
|
*/
|
|
ret = process_all_extents(sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = process_all_new_xattrs(sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
} else {
|
|
sctx->cur_inode_gen = left_gen;
|
|
sctx->cur_inode_new = 0;
|
|
sctx->cur_inode_new_gen = 0;
|
|
sctx->cur_inode_deleted = 0;
|
|
sctx->cur_inode_size = btrfs_inode_size(
|
|
sctx->left_path->nodes[0], left_ii);
|
|
sctx->cur_inode_mode = btrfs_inode_mode(
|
|
sctx->left_path->nodes[0], left_ii);
|
|
}
|
|
}
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* We have to process new refs before deleted refs, but compare_trees gives us
|
|
* the new and deleted refs mixed. To fix this, we record the new/deleted refs
|
|
* first and later process them in process_recorded_refs.
|
|
* For the cur_inode_new_gen case, we skip recording completely because
|
|
* changed_inode did already initiate processing of refs. The reason for this is
|
|
* that in this case, compare_tree actually compares the refs of 2 different
|
|
* inodes. To fix this, process_all_refs is used in changed_inode to handle all
|
|
* refs of the right tree as deleted and all refs of the left tree as new.
|
|
*/
|
|
static int changed_ref(struct send_ctx *sctx,
|
|
enum btrfs_compare_tree_result result)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (sctx->cur_ino != sctx->cmp_key->objectid) {
|
|
inconsistent_snapshot_error(sctx, result, "reference");
|
|
return -EIO;
|
|
}
|
|
|
|
if (!sctx->cur_inode_new_gen &&
|
|
sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID) {
|
|
if (result == BTRFS_COMPARE_TREE_NEW)
|
|
ret = record_new_ref(sctx);
|
|
else if (result == BTRFS_COMPARE_TREE_DELETED)
|
|
ret = record_deleted_ref(sctx);
|
|
else if (result == BTRFS_COMPARE_TREE_CHANGED)
|
|
ret = record_changed_ref(sctx);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Process new/deleted/changed xattrs. We skip processing in the
|
|
* cur_inode_new_gen case because changed_inode did already initiate processing
|
|
* of xattrs. The reason is the same as in changed_ref
|
|
*/
|
|
static int changed_xattr(struct send_ctx *sctx,
|
|
enum btrfs_compare_tree_result result)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (sctx->cur_ino != sctx->cmp_key->objectid) {
|
|
inconsistent_snapshot_error(sctx, result, "xattr");
|
|
return -EIO;
|
|
}
|
|
|
|
if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
|
|
if (result == BTRFS_COMPARE_TREE_NEW)
|
|
ret = process_new_xattr(sctx);
|
|
else if (result == BTRFS_COMPARE_TREE_DELETED)
|
|
ret = process_deleted_xattr(sctx);
|
|
else if (result == BTRFS_COMPARE_TREE_CHANGED)
|
|
ret = process_changed_xattr(sctx);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Process new/deleted/changed extents. We skip processing in the
|
|
* cur_inode_new_gen case because changed_inode did already initiate processing
|
|
* of extents. The reason is the same as in changed_ref
|
|
*/
|
|
static int changed_extent(struct send_ctx *sctx,
|
|
enum btrfs_compare_tree_result result)
|
|
{
|
|
int ret = 0;
|
|
|
|
/*
|
|
* We have found an extent item that changed without the inode item
|
|
* having changed. This can happen either after relocation (where the
|
|
* disk_bytenr of an extent item is replaced at
|
|
* relocation.c:replace_file_extents()) or after deduplication into a
|
|
* file in both the parent and send snapshots (where an extent item can
|
|
* get modified or replaced with a new one). Note that deduplication
|
|
* updates the inode item, but it only changes the iversion (sequence
|
|
* field in the inode item) of the inode, so if a file is deduplicated
|
|
* the same amount of times in both the parent and send snapshots, its
|
|
* iversion becomes the same in both snapshots, whence the inode item is
|
|
* the same on both snapshots.
|
|
*/
|
|
if (sctx->cur_ino != sctx->cmp_key->objectid)
|
|
return 0;
|
|
|
|
if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
|
|
if (result != BTRFS_COMPARE_TREE_DELETED)
|
|
ret = process_extent(sctx, sctx->left_path,
|
|
sctx->cmp_key);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int dir_changed(struct send_ctx *sctx, u64 dir)
|
|
{
|
|
u64 orig_gen, new_gen;
|
|
int ret;
|
|
|
|
ret = get_inode_info(sctx->send_root, dir, NULL, &new_gen, NULL, NULL,
|
|
NULL, NULL);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = get_inode_info(sctx->parent_root, dir, NULL, &orig_gen, NULL,
|
|
NULL, NULL, NULL);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return (orig_gen != new_gen) ? 1 : 0;
|
|
}
|
|
|
|
static int compare_refs(struct send_ctx *sctx, struct btrfs_path *path,
|
|
struct btrfs_key *key)
|
|
{
|
|
struct btrfs_inode_extref *extref;
|
|
struct extent_buffer *leaf;
|
|
u64 dirid = 0, last_dirid = 0;
|
|
unsigned long ptr;
|
|
u32 item_size;
|
|
u32 cur_offset = 0;
|
|
int ref_name_len;
|
|
int ret = 0;
|
|
|
|
/* Easy case, just check this one dirid */
|
|
if (key->type == BTRFS_INODE_REF_KEY) {
|
|
dirid = key->offset;
|
|
|
|
ret = dir_changed(sctx, dirid);
|
|
goto out;
|
|
}
|
|
|
|
leaf = path->nodes[0];
|
|
item_size = btrfs_item_size(leaf, path->slots[0]);
|
|
ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
|
|
while (cur_offset < item_size) {
|
|
extref = (struct btrfs_inode_extref *)(ptr +
|
|
cur_offset);
|
|
dirid = btrfs_inode_extref_parent(leaf, extref);
|
|
ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
|
|
cur_offset += ref_name_len + sizeof(*extref);
|
|
if (dirid == last_dirid)
|
|
continue;
|
|
ret = dir_changed(sctx, dirid);
|
|
if (ret)
|
|
break;
|
|
last_dirid = dirid;
|
|
}
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Updates compare related fields in sctx and simply forwards to the actual
|
|
* changed_xxx functions.
|
|
*/
|
|
static int changed_cb(struct btrfs_path *left_path,
|
|
struct btrfs_path *right_path,
|
|
struct btrfs_key *key,
|
|
enum btrfs_compare_tree_result result,
|
|
struct send_ctx *sctx)
|
|
{
|
|
int ret = 0;
|
|
|
|
/*
|
|
* We can not hold the commit root semaphore here. This is because in
|
|
* the case of sending and receiving to the same filesystem, using a
|
|
* pipe, could result in a deadlock:
|
|
*
|
|
* 1) The task running send blocks on the pipe because it's full;
|
|
*
|
|
* 2) The task running receive, which is the only consumer of the pipe,
|
|
* is waiting for a transaction commit (for example due to a space
|
|
* reservation when doing a write or triggering a transaction commit
|
|
* when creating a subvolume);
|
|
*
|
|
* 3) The transaction is waiting to write lock the commit root semaphore,
|
|
* but can not acquire it since it's being held at 1).
|
|
*
|
|
* Down this call chain we write to the pipe through kernel_write().
|
|
* The same type of problem can also happen when sending to a file that
|
|
* is stored in the same filesystem - when reserving space for a write
|
|
* into the file, we can trigger a transaction commit.
|
|
*
|
|
* Our caller has supplied us with clones of leaves from the send and
|
|
* parent roots, so we're safe here from a concurrent relocation and
|
|
* further reallocation of metadata extents while we are here. Below we
|
|
* also assert that the leaves are clones.
|
|
*/
|
|
lockdep_assert_not_held(&sctx->send_root->fs_info->commit_root_sem);
|
|
|
|
/*
|
|
* We always have a send root, so left_path is never NULL. We will not
|
|
* have a leaf when we have reached the end of the send root but have
|
|
* not yet reached the end of the parent root.
|
|
*/
|
|
if (left_path->nodes[0])
|
|
ASSERT(test_bit(EXTENT_BUFFER_UNMAPPED,
|
|
&left_path->nodes[0]->bflags));
|
|
/*
|
|
* When doing a full send we don't have a parent root, so right_path is
|
|
* NULL. When doing an incremental send, we may have reached the end of
|
|
* the parent root already, so we don't have a leaf at right_path.
|
|
*/
|
|
if (right_path && right_path->nodes[0])
|
|
ASSERT(test_bit(EXTENT_BUFFER_UNMAPPED,
|
|
&right_path->nodes[0]->bflags));
|
|
|
|
if (result == BTRFS_COMPARE_TREE_SAME) {
|
|
if (key->type == BTRFS_INODE_REF_KEY ||
|
|
key->type == BTRFS_INODE_EXTREF_KEY) {
|
|
ret = compare_refs(sctx, left_path, key);
|
|
if (!ret)
|
|
return 0;
|
|
if (ret < 0)
|
|
return ret;
|
|
} else if (key->type == BTRFS_EXTENT_DATA_KEY) {
|
|
return maybe_send_hole(sctx, left_path, key);
|
|
} else {
|
|
return 0;
|
|
}
|
|
result = BTRFS_COMPARE_TREE_CHANGED;
|
|
ret = 0;
|
|
}
|
|
|
|
sctx->left_path = left_path;
|
|
sctx->right_path = right_path;
|
|
sctx->cmp_key = key;
|
|
|
|
ret = finish_inode_if_needed(sctx, 0);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
/* Ignore non-FS objects */
|
|
if (key->objectid == BTRFS_FREE_INO_OBJECTID ||
|
|
key->objectid == BTRFS_FREE_SPACE_OBJECTID)
|
|
goto out;
|
|
|
|
if (key->type == BTRFS_INODE_ITEM_KEY) {
|
|
ret = changed_inode(sctx, result);
|
|
} else if (!sctx->ignore_cur_inode) {
|
|
if (key->type == BTRFS_INODE_REF_KEY ||
|
|
key->type == BTRFS_INODE_EXTREF_KEY)
|
|
ret = changed_ref(sctx, result);
|
|
else if (key->type == BTRFS_XATTR_ITEM_KEY)
|
|
ret = changed_xattr(sctx, result);
|
|
else if (key->type == BTRFS_EXTENT_DATA_KEY)
|
|
ret = changed_extent(sctx, result);
|
|
}
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int search_key_again(const struct send_ctx *sctx,
|
|
struct btrfs_root *root,
|
|
struct btrfs_path *path,
|
|
const struct btrfs_key *key)
|
|
{
|
|
int ret;
|
|
|
|
if (!path->need_commit_sem)
|
|
lockdep_assert_held_read(&root->fs_info->commit_root_sem);
|
|
|
|
/*
|
|
* Roots used for send operations are readonly and no one can add,
|
|
* update or remove keys from them, so we should be able to find our
|
|
* key again. The only exception is deduplication, which can operate on
|
|
* readonly roots and add, update or remove keys to/from them - but at
|
|
* the moment we don't allow it to run in parallel with send.
|
|
*/
|
|
ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
|
|
ASSERT(ret <= 0);
|
|
if (ret > 0) {
|
|
btrfs_print_tree(path->nodes[path->lowest_level], false);
|
|
btrfs_err(root->fs_info,
|
|
"send: key (%llu %u %llu) not found in %s root %llu, lowest_level %d, slot %d",
|
|
key->objectid, key->type, key->offset,
|
|
(root == sctx->parent_root ? "parent" : "send"),
|
|
root->root_key.objectid, path->lowest_level,
|
|
path->slots[path->lowest_level]);
|
|
return -EUCLEAN;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int full_send_tree(struct send_ctx *sctx)
|
|
{
|
|
int ret;
|
|
struct btrfs_root *send_root = sctx->send_root;
|
|
struct btrfs_key key;
|
|
struct btrfs_fs_info *fs_info = send_root->fs_info;
|
|
struct btrfs_path *path;
|
|
|
|
path = alloc_path_for_send();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
path->reada = READA_FORWARD_ALWAYS;
|
|
|
|
key.objectid = BTRFS_FIRST_FREE_OBJECTID;
|
|
key.type = BTRFS_INODE_ITEM_KEY;
|
|
key.offset = 0;
|
|
|
|
down_read(&fs_info->commit_root_sem);
|
|
sctx->last_reloc_trans = fs_info->last_reloc_trans;
|
|
up_read(&fs_info->commit_root_sem);
|
|
|
|
ret = btrfs_search_slot_for_read(send_root, &key, path, 1, 0);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret)
|
|
goto out_finish;
|
|
|
|
while (1) {
|
|
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
|
|
|
|
ret = changed_cb(path, NULL, &key,
|
|
BTRFS_COMPARE_TREE_NEW, sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
down_read(&fs_info->commit_root_sem);
|
|
if (fs_info->last_reloc_trans > sctx->last_reloc_trans) {
|
|
sctx->last_reloc_trans = fs_info->last_reloc_trans;
|
|
up_read(&fs_info->commit_root_sem);
|
|
/*
|
|
* A transaction used for relocating a block group was
|
|
* committed or is about to finish its commit. Release
|
|
* our path (leaf) and restart the search, so that we
|
|
* avoid operating on any file extent items that are
|
|
* stale, with a disk_bytenr that reflects a pre
|
|
* relocation value. This way we avoid as much as
|
|
* possible to fallback to regular writes when checking
|
|
* if we can clone file ranges.
|
|
*/
|
|
btrfs_release_path(path);
|
|
ret = search_key_again(sctx, send_root, path, &key);
|
|
if (ret < 0)
|
|
goto out;
|
|
} else {
|
|
up_read(&fs_info->commit_root_sem);
|
|
}
|
|
|
|
ret = btrfs_next_item(send_root, path);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret) {
|
|
ret = 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
out_finish:
|
|
ret = finish_inode_if_needed(sctx, 1);
|
|
|
|
out:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
static int replace_node_with_clone(struct btrfs_path *path, int level)
|
|
{
|
|
struct extent_buffer *clone;
|
|
|
|
clone = btrfs_clone_extent_buffer(path->nodes[level]);
|
|
if (!clone)
|
|
return -ENOMEM;
|
|
|
|
free_extent_buffer(path->nodes[level]);
|
|
path->nodes[level] = clone;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int tree_move_down(struct btrfs_path *path, int *level, u64 reada_min_gen)
|
|
{
|
|
struct extent_buffer *eb;
|
|
struct extent_buffer *parent = path->nodes[*level];
|
|
int slot = path->slots[*level];
|
|
const int nritems = btrfs_header_nritems(parent);
|
|
u64 reada_max;
|
|
u64 reada_done = 0;
|
|
|
|
lockdep_assert_held_read(&parent->fs_info->commit_root_sem);
|
|
|
|
BUG_ON(*level == 0);
|
|
eb = btrfs_read_node_slot(parent, slot);
|
|
if (IS_ERR(eb))
|
|
return PTR_ERR(eb);
|
|
|
|
/*
|
|
* Trigger readahead for the next leaves we will process, so that it is
|
|
* very likely that when we need them they are already in memory and we
|
|
* will not block on disk IO. For nodes we only do readahead for one,
|
|
* since the time window between processing nodes is typically larger.
|
|
*/
|
|
reada_max = (*level == 1 ? SZ_128K : eb->fs_info->nodesize);
|
|
|
|
for (slot++; slot < nritems && reada_done < reada_max; slot++) {
|
|
if (btrfs_node_ptr_generation(parent, slot) > reada_min_gen) {
|
|
btrfs_readahead_node_child(parent, slot);
|
|
reada_done += eb->fs_info->nodesize;
|
|
}
|
|
}
|
|
|
|
path->nodes[*level - 1] = eb;
|
|
path->slots[*level - 1] = 0;
|
|
(*level)--;
|
|
|
|
if (*level == 0)
|
|
return replace_node_with_clone(path, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int tree_move_next_or_upnext(struct btrfs_path *path,
|
|
int *level, int root_level)
|
|
{
|
|
int ret = 0;
|
|
int nritems;
|
|
nritems = btrfs_header_nritems(path->nodes[*level]);
|
|
|
|
path->slots[*level]++;
|
|
|
|
while (path->slots[*level] >= nritems) {
|
|
if (*level == root_level) {
|
|
path->slots[*level] = nritems - 1;
|
|
return -1;
|
|
}
|
|
|
|
/* move upnext */
|
|
path->slots[*level] = 0;
|
|
free_extent_buffer(path->nodes[*level]);
|
|
path->nodes[*level] = NULL;
|
|
(*level)++;
|
|
path->slots[*level]++;
|
|
|
|
nritems = btrfs_header_nritems(path->nodes[*level]);
|
|
ret = 1;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Returns 1 if it had to move up and next. 0 is returned if it moved only next
|
|
* or down.
|
|
*/
|
|
static int tree_advance(struct btrfs_path *path,
|
|
int *level, int root_level,
|
|
int allow_down,
|
|
struct btrfs_key *key,
|
|
u64 reada_min_gen)
|
|
{
|
|
int ret;
|
|
|
|
if (*level == 0 || !allow_down) {
|
|
ret = tree_move_next_or_upnext(path, level, root_level);
|
|
} else {
|
|
ret = tree_move_down(path, level, reada_min_gen);
|
|
}
|
|
|
|
/*
|
|
* Even if we have reached the end of a tree, ret is -1, update the key
|
|
* anyway, so that in case we need to restart due to a block group
|
|
* relocation, we can assert that the last key of the root node still
|
|
* exists in the tree.
|
|
*/
|
|
if (*level == 0)
|
|
btrfs_item_key_to_cpu(path->nodes[*level], key,
|
|
path->slots[*level]);
|
|
else
|
|
btrfs_node_key_to_cpu(path->nodes[*level], key,
|
|
path->slots[*level]);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int tree_compare_item(struct btrfs_path *left_path,
|
|
struct btrfs_path *right_path,
|
|
char *tmp_buf)
|
|
{
|
|
int cmp;
|
|
int len1, len2;
|
|
unsigned long off1, off2;
|
|
|
|
len1 = btrfs_item_size(left_path->nodes[0], left_path->slots[0]);
|
|
len2 = btrfs_item_size(right_path->nodes[0], right_path->slots[0]);
|
|
if (len1 != len2)
|
|
return 1;
|
|
|
|
off1 = btrfs_item_ptr_offset(left_path->nodes[0], left_path->slots[0]);
|
|
off2 = btrfs_item_ptr_offset(right_path->nodes[0],
|
|
right_path->slots[0]);
|
|
|
|
read_extent_buffer(left_path->nodes[0], tmp_buf, off1, len1);
|
|
|
|
cmp = memcmp_extent_buffer(right_path->nodes[0], tmp_buf, off2, len1);
|
|
if (cmp)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* A transaction used for relocating a block group was committed or is about to
|
|
* finish its commit. Release our paths and restart the search, so that we are
|
|
* not using stale extent buffers:
|
|
*
|
|
* 1) For levels > 0, we are only holding references of extent buffers, without
|
|
* any locks on them, which does not prevent them from having been relocated
|
|
* and reallocated after the last time we released the commit root semaphore.
|
|
* The exception are the root nodes, for which we always have a clone, see
|
|
* the comment at btrfs_compare_trees();
|
|
*
|
|
* 2) For leaves, level 0, we are holding copies (clones) of extent buffers, so
|
|
* we are safe from the concurrent relocation and reallocation. However they
|
|
* can have file extent items with a pre relocation disk_bytenr value, so we
|
|
* restart the start from the current commit roots and clone the new leaves so
|
|
* that we get the post relocation disk_bytenr values. Not doing so, could
|
|
* make us clone the wrong data in case there are new extents using the old
|
|
* disk_bytenr that happen to be shared.
|
|
*/
|
|
static int restart_after_relocation(struct btrfs_path *left_path,
|
|
struct btrfs_path *right_path,
|
|
const struct btrfs_key *left_key,
|
|
const struct btrfs_key *right_key,
|
|
int left_level,
|
|
int right_level,
|
|
const struct send_ctx *sctx)
|
|
{
|
|
int root_level;
|
|
int ret;
|
|
|
|
lockdep_assert_held_read(&sctx->send_root->fs_info->commit_root_sem);
|
|
|
|
btrfs_release_path(left_path);
|
|
btrfs_release_path(right_path);
|
|
|
|
/*
|
|
* Since keys can not be added or removed to/from our roots because they
|
|
* are readonly and we do not allow deduplication to run in parallel
|
|
* (which can add, remove or change keys), the layout of the trees should
|
|
* not change.
|
|
*/
|
|
left_path->lowest_level = left_level;
|
|
ret = search_key_again(sctx, sctx->send_root, left_path, left_key);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
right_path->lowest_level = right_level;
|
|
ret = search_key_again(sctx, sctx->parent_root, right_path, right_key);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
/*
|
|
* If the lowest level nodes are leaves, clone them so that they can be
|
|
* safely used by changed_cb() while not under the protection of the
|
|
* commit root semaphore, even if relocation and reallocation happens in
|
|
* parallel.
|
|
*/
|
|
if (left_level == 0) {
|
|
ret = replace_node_with_clone(left_path, 0);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
if (right_level == 0) {
|
|
ret = replace_node_with_clone(right_path, 0);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Now clone the root nodes (unless they happen to be the leaves we have
|
|
* already cloned). This is to protect against concurrent snapshotting of
|
|
* the send and parent roots (see the comment at btrfs_compare_trees()).
|
|
*/
|
|
root_level = btrfs_header_level(sctx->send_root->commit_root);
|
|
if (root_level > 0) {
|
|
ret = replace_node_with_clone(left_path, root_level);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
root_level = btrfs_header_level(sctx->parent_root->commit_root);
|
|
if (root_level > 0) {
|
|
ret = replace_node_with_clone(right_path, root_level);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* This function compares two trees and calls the provided callback for
|
|
* every changed/new/deleted item it finds.
|
|
* If shared tree blocks are encountered, whole subtrees are skipped, making
|
|
* the compare pretty fast on snapshotted subvolumes.
|
|
*
|
|
* This currently works on commit roots only. As commit roots are read only,
|
|
* we don't do any locking. The commit roots are protected with transactions.
|
|
* Transactions are ended and rejoined when a commit is tried in between.
|
|
*
|
|
* This function checks for modifications done to the trees while comparing.
|
|
* If it detects a change, it aborts immediately.
|
|
*/
|
|
static int btrfs_compare_trees(struct btrfs_root *left_root,
|
|
struct btrfs_root *right_root, struct send_ctx *sctx)
|
|
{
|
|
struct btrfs_fs_info *fs_info = left_root->fs_info;
|
|
int ret;
|
|
int cmp;
|
|
struct btrfs_path *left_path = NULL;
|
|
struct btrfs_path *right_path = NULL;
|
|
struct btrfs_key left_key;
|
|
struct btrfs_key right_key;
|
|
char *tmp_buf = NULL;
|
|
int left_root_level;
|
|
int right_root_level;
|
|
int left_level;
|
|
int right_level;
|
|
int left_end_reached = 0;
|
|
int right_end_reached = 0;
|
|
int advance_left = 0;
|
|
int advance_right = 0;
|
|
u64 left_blockptr;
|
|
u64 right_blockptr;
|
|
u64 left_gen;
|
|
u64 right_gen;
|
|
u64 reada_min_gen;
|
|
|
|
left_path = btrfs_alloc_path();
|
|
if (!left_path) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
right_path = btrfs_alloc_path();
|
|
if (!right_path) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
tmp_buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
|
|
if (!tmp_buf) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
left_path->search_commit_root = 1;
|
|
left_path->skip_locking = 1;
|
|
right_path->search_commit_root = 1;
|
|
right_path->skip_locking = 1;
|
|
|
|
/*
|
|
* Strategy: Go to the first items of both trees. Then do
|
|
*
|
|
* If both trees are at level 0
|
|
* Compare keys of current items
|
|
* If left < right treat left item as new, advance left tree
|
|
* and repeat
|
|
* If left > right treat right item as deleted, advance right tree
|
|
* and repeat
|
|
* If left == right do deep compare of items, treat as changed if
|
|
* needed, advance both trees and repeat
|
|
* If both trees are at the same level but not at level 0
|
|
* Compare keys of current nodes/leafs
|
|
* If left < right advance left tree and repeat
|
|
* If left > right advance right tree and repeat
|
|
* If left == right compare blockptrs of the next nodes/leafs
|
|
* If they match advance both trees but stay at the same level
|
|
* and repeat
|
|
* If they don't match advance both trees while allowing to go
|
|
* deeper and repeat
|
|
* If tree levels are different
|
|
* Advance the tree that needs it and repeat
|
|
*
|
|
* Advancing a tree means:
|
|
* If we are at level 0, try to go to the next slot. If that's not
|
|
* possible, go one level up and repeat. Stop when we found a level
|
|
* where we could go to the next slot. We may at this point be on a
|
|
* node or a leaf.
|
|
*
|
|
* If we are not at level 0 and not on shared tree blocks, go one
|
|
* level deeper.
|
|
*
|
|
* If we are not at level 0 and on shared tree blocks, go one slot to
|
|
* the right if possible or go up and right.
|
|
*/
|
|
|
|
down_read(&fs_info->commit_root_sem);
|
|
left_level = btrfs_header_level(left_root->commit_root);
|
|
left_root_level = left_level;
|
|
/*
|
|
* We clone the root node of the send and parent roots to prevent races
|
|
* with snapshot creation of these roots. Snapshot creation COWs the
|
|
* root node of a tree, so after the transaction is committed the old
|
|
* extent can be reallocated while this send operation is still ongoing.
|
|
* So we clone them, under the commit root semaphore, to be race free.
|
|
*/
|
|
left_path->nodes[left_level] =
|
|
btrfs_clone_extent_buffer(left_root->commit_root);
|
|
if (!left_path->nodes[left_level]) {
|
|
ret = -ENOMEM;
|
|
goto out_unlock;
|
|
}
|
|
|
|
right_level = btrfs_header_level(right_root->commit_root);
|
|
right_root_level = right_level;
|
|
right_path->nodes[right_level] =
|
|
btrfs_clone_extent_buffer(right_root->commit_root);
|
|
if (!right_path->nodes[right_level]) {
|
|
ret = -ENOMEM;
|
|
goto out_unlock;
|
|
}
|
|
/*
|
|
* Our right root is the parent root, while the left root is the "send"
|
|
* root. We know that all new nodes/leaves in the left root must have
|
|
* a generation greater than the right root's generation, so we trigger
|
|
* readahead for those nodes and leaves of the left root, as we know we
|
|
* will need to read them at some point.
|
|
*/
|
|
reada_min_gen = btrfs_header_generation(right_root->commit_root);
|
|
|
|
if (left_level == 0)
|
|
btrfs_item_key_to_cpu(left_path->nodes[left_level],
|
|
&left_key, left_path->slots[left_level]);
|
|
else
|
|
btrfs_node_key_to_cpu(left_path->nodes[left_level],
|
|
&left_key, left_path->slots[left_level]);
|
|
if (right_level == 0)
|
|
btrfs_item_key_to_cpu(right_path->nodes[right_level],
|
|
&right_key, right_path->slots[right_level]);
|
|
else
|
|
btrfs_node_key_to_cpu(right_path->nodes[right_level],
|
|
&right_key, right_path->slots[right_level]);
|
|
|
|
sctx->last_reloc_trans = fs_info->last_reloc_trans;
|
|
|
|
while (1) {
|
|
if (need_resched() ||
|
|
rwsem_is_contended(&fs_info->commit_root_sem)) {
|
|
up_read(&fs_info->commit_root_sem);
|
|
cond_resched();
|
|
down_read(&fs_info->commit_root_sem);
|
|
}
|
|
|
|
if (fs_info->last_reloc_trans > sctx->last_reloc_trans) {
|
|
ret = restart_after_relocation(left_path, right_path,
|
|
&left_key, &right_key,
|
|
left_level, right_level,
|
|
sctx);
|
|
if (ret < 0)
|
|
goto out_unlock;
|
|
sctx->last_reloc_trans = fs_info->last_reloc_trans;
|
|
}
|
|
|
|
if (advance_left && !left_end_reached) {
|
|
ret = tree_advance(left_path, &left_level,
|
|
left_root_level,
|
|
advance_left != ADVANCE_ONLY_NEXT,
|
|
&left_key, reada_min_gen);
|
|
if (ret == -1)
|
|
left_end_reached = ADVANCE;
|
|
else if (ret < 0)
|
|
goto out_unlock;
|
|
advance_left = 0;
|
|
}
|
|
if (advance_right && !right_end_reached) {
|
|
ret = tree_advance(right_path, &right_level,
|
|
right_root_level,
|
|
advance_right != ADVANCE_ONLY_NEXT,
|
|
&right_key, reada_min_gen);
|
|
if (ret == -1)
|
|
right_end_reached = ADVANCE;
|
|
else if (ret < 0)
|
|
goto out_unlock;
|
|
advance_right = 0;
|
|
}
|
|
|
|
if (left_end_reached && right_end_reached) {
|
|
ret = 0;
|
|
goto out_unlock;
|
|
} else if (left_end_reached) {
|
|
if (right_level == 0) {
|
|
up_read(&fs_info->commit_root_sem);
|
|
ret = changed_cb(left_path, right_path,
|
|
&right_key,
|
|
BTRFS_COMPARE_TREE_DELETED,
|
|
sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
down_read(&fs_info->commit_root_sem);
|
|
}
|
|
advance_right = ADVANCE;
|
|
continue;
|
|
} else if (right_end_reached) {
|
|
if (left_level == 0) {
|
|
up_read(&fs_info->commit_root_sem);
|
|
ret = changed_cb(left_path, right_path,
|
|
&left_key,
|
|
BTRFS_COMPARE_TREE_NEW,
|
|
sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
down_read(&fs_info->commit_root_sem);
|
|
}
|
|
advance_left = ADVANCE;
|
|
continue;
|
|
}
|
|
|
|
if (left_level == 0 && right_level == 0) {
|
|
up_read(&fs_info->commit_root_sem);
|
|
cmp = btrfs_comp_cpu_keys(&left_key, &right_key);
|
|
if (cmp < 0) {
|
|
ret = changed_cb(left_path, right_path,
|
|
&left_key,
|
|
BTRFS_COMPARE_TREE_NEW,
|
|
sctx);
|
|
advance_left = ADVANCE;
|
|
} else if (cmp > 0) {
|
|
ret = changed_cb(left_path, right_path,
|
|
&right_key,
|
|
BTRFS_COMPARE_TREE_DELETED,
|
|
sctx);
|
|
advance_right = ADVANCE;
|
|
} else {
|
|
enum btrfs_compare_tree_result result;
|
|
|
|
WARN_ON(!extent_buffer_uptodate(left_path->nodes[0]));
|
|
ret = tree_compare_item(left_path, right_path,
|
|
tmp_buf);
|
|
if (ret)
|
|
result = BTRFS_COMPARE_TREE_CHANGED;
|
|
else
|
|
result = BTRFS_COMPARE_TREE_SAME;
|
|
ret = changed_cb(left_path, right_path,
|
|
&left_key, result, sctx);
|
|
advance_left = ADVANCE;
|
|
advance_right = ADVANCE;
|
|
}
|
|
|
|
if (ret < 0)
|
|
goto out;
|
|
down_read(&fs_info->commit_root_sem);
|
|
} else if (left_level == right_level) {
|
|
cmp = btrfs_comp_cpu_keys(&left_key, &right_key);
|
|
if (cmp < 0) {
|
|
advance_left = ADVANCE;
|
|
} else if (cmp > 0) {
|
|
advance_right = ADVANCE;
|
|
} else {
|
|
left_blockptr = btrfs_node_blockptr(
|
|
left_path->nodes[left_level],
|
|
left_path->slots[left_level]);
|
|
right_blockptr = btrfs_node_blockptr(
|
|
right_path->nodes[right_level],
|
|
right_path->slots[right_level]);
|
|
left_gen = btrfs_node_ptr_generation(
|
|
left_path->nodes[left_level],
|
|
left_path->slots[left_level]);
|
|
right_gen = btrfs_node_ptr_generation(
|
|
right_path->nodes[right_level],
|
|
right_path->slots[right_level]);
|
|
if (left_blockptr == right_blockptr &&
|
|
left_gen == right_gen) {
|
|
/*
|
|
* As we're on a shared block, don't
|
|
* allow to go deeper.
|
|
*/
|
|
advance_left = ADVANCE_ONLY_NEXT;
|
|
advance_right = ADVANCE_ONLY_NEXT;
|
|
} else {
|
|
advance_left = ADVANCE;
|
|
advance_right = ADVANCE;
|
|
}
|
|
}
|
|
} else if (left_level < right_level) {
|
|
advance_right = ADVANCE;
|
|
} else {
|
|
advance_left = ADVANCE;
|
|
}
|
|
}
|
|
|
|
out_unlock:
|
|
up_read(&fs_info->commit_root_sem);
|
|
out:
|
|
btrfs_free_path(left_path);
|
|
btrfs_free_path(right_path);
|
|
kvfree(tmp_buf);
|
|
return ret;
|
|
}
|
|
|
|
static int send_subvol(struct send_ctx *sctx)
|
|
{
|
|
int ret;
|
|
|
|
if (!(sctx->flags & BTRFS_SEND_FLAG_OMIT_STREAM_HEADER)) {
|
|
ret = send_header(sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
|
|
ret = send_subvol_begin(sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
if (sctx->parent_root) {
|
|
ret = btrfs_compare_trees(sctx->send_root, sctx->parent_root, sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = finish_inode_if_needed(sctx, 1);
|
|
if (ret < 0)
|
|
goto out;
|
|
} else {
|
|
ret = full_send_tree(sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
|
|
out:
|
|
free_recorded_refs(sctx);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* If orphan cleanup did remove any orphans from a root, it means the tree
|
|
* was modified and therefore the commit root is not the same as the current
|
|
* root anymore. This is a problem, because send uses the commit root and
|
|
* therefore can see inode items that don't exist in the current root anymore,
|
|
* and for example make calls to btrfs_iget, which will do tree lookups based
|
|
* on the current root and not on the commit root. Those lookups will fail,
|
|
* returning a -ESTALE error, and making send fail with that error. So make
|
|
* sure a send does not see any orphans we have just removed, and that it will
|
|
* see the same inodes regardless of whether a transaction commit happened
|
|
* before it started (meaning that the commit root will be the same as the
|
|
* current root) or not.
|
|
*/
|
|
static int ensure_commit_roots_uptodate(struct send_ctx *sctx)
|
|
{
|
|
int i;
|
|
struct btrfs_trans_handle *trans = NULL;
|
|
|
|
again:
|
|
if (sctx->parent_root &&
|
|
sctx->parent_root->node != sctx->parent_root->commit_root)
|
|
goto commit_trans;
|
|
|
|
for (i = 0; i < sctx->clone_roots_cnt; i++)
|
|
if (sctx->clone_roots[i].root->node !=
|
|
sctx->clone_roots[i].root->commit_root)
|
|
goto commit_trans;
|
|
|
|
if (trans)
|
|
return btrfs_end_transaction(trans);
|
|
|
|
return 0;
|
|
|
|
commit_trans:
|
|
/* Use any root, all fs roots will get their commit roots updated. */
|
|
if (!trans) {
|
|
trans = btrfs_join_transaction(sctx->send_root);
|
|
if (IS_ERR(trans))
|
|
return PTR_ERR(trans);
|
|
goto again;
|
|
}
|
|
|
|
return btrfs_commit_transaction(trans);
|
|
}
|
|
|
|
/*
|
|
* Make sure any existing dellaloc is flushed for any root used by a send
|
|
* operation so that we do not miss any data and we do not race with writeback
|
|
* finishing and changing a tree while send is using the tree. This could
|
|
* happen if a subvolume is in RW mode, has delalloc, is turned to RO mode and
|
|
* a send operation then uses the subvolume.
|
|
* After flushing delalloc ensure_commit_roots_uptodate() must be called.
|
|
*/
|
|
static int flush_delalloc_roots(struct send_ctx *sctx)
|
|
{
|
|
struct btrfs_root *root = sctx->parent_root;
|
|
int ret;
|
|
int i;
|
|
|
|
if (root) {
|
|
ret = btrfs_start_delalloc_snapshot(root, false);
|
|
if (ret)
|
|
return ret;
|
|
btrfs_wait_ordered_extents(root, U64_MAX, 0, U64_MAX);
|
|
}
|
|
|
|
for (i = 0; i < sctx->clone_roots_cnt; i++) {
|
|
root = sctx->clone_roots[i].root;
|
|
ret = btrfs_start_delalloc_snapshot(root, false);
|
|
if (ret)
|
|
return ret;
|
|
btrfs_wait_ordered_extents(root, U64_MAX, 0, U64_MAX);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void btrfs_root_dec_send_in_progress(struct btrfs_root* root)
|
|
{
|
|
spin_lock(&root->root_item_lock);
|
|
root->send_in_progress--;
|
|
/*
|
|
* Not much left to do, we don't know why it's unbalanced and
|
|
* can't blindly reset it to 0.
|
|
*/
|
|
if (root->send_in_progress < 0)
|
|
btrfs_err(root->fs_info,
|
|
"send_in_progress unbalanced %d root %llu",
|
|
root->send_in_progress, root->root_key.objectid);
|
|
spin_unlock(&root->root_item_lock);
|
|
}
|
|
|
|
static void dedupe_in_progress_warn(const struct btrfs_root *root)
|
|
{
|
|
btrfs_warn_rl(root->fs_info,
|
|
"cannot use root %llu for send while deduplications on it are in progress (%d in progress)",
|
|
root->root_key.objectid, root->dedupe_in_progress);
|
|
}
|
|
|
|
long btrfs_ioctl_send(struct inode *inode, struct btrfs_ioctl_send_args *arg)
|
|
{
|
|
int ret = 0;
|
|
struct btrfs_root *send_root = BTRFS_I(inode)->root;
|
|
struct btrfs_fs_info *fs_info = send_root->fs_info;
|
|
struct btrfs_root *clone_root;
|
|
struct send_ctx *sctx = NULL;
|
|
u32 i;
|
|
u64 *clone_sources_tmp = NULL;
|
|
int clone_sources_to_rollback = 0;
|
|
size_t alloc_size;
|
|
int sort_clone_roots = 0;
|
|
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
|
|
/*
|
|
* The subvolume must remain read-only during send, protect against
|
|
* making it RW. This also protects against deletion.
|
|
*/
|
|
spin_lock(&send_root->root_item_lock);
|
|
if (btrfs_root_readonly(send_root) && send_root->dedupe_in_progress) {
|
|
dedupe_in_progress_warn(send_root);
|
|
spin_unlock(&send_root->root_item_lock);
|
|
return -EAGAIN;
|
|
}
|
|
send_root->send_in_progress++;
|
|
spin_unlock(&send_root->root_item_lock);
|
|
|
|
/*
|
|
* Userspace tools do the checks and warn the user if it's
|
|
* not RO.
|
|
*/
|
|
if (!btrfs_root_readonly(send_root)) {
|
|
ret = -EPERM;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Check that we don't overflow at later allocations, we request
|
|
* clone_sources_count + 1 items, and compare to unsigned long inside
|
|
* access_ok.
|
|
*/
|
|
if (arg->clone_sources_count >
|
|
ULONG_MAX / sizeof(struct clone_root) - 1) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (arg->flags & ~BTRFS_SEND_FLAG_MASK) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
sctx = kzalloc(sizeof(struct send_ctx), GFP_KERNEL);
|
|
if (!sctx) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
INIT_LIST_HEAD(&sctx->new_refs);
|
|
INIT_LIST_HEAD(&sctx->deleted_refs);
|
|
xa_init_flags(&sctx->name_cache, GFP_KERNEL);
|
|
INIT_LIST_HEAD(&sctx->name_cache_list);
|
|
|
|
sctx->flags = arg->flags;
|
|
|
|
if (arg->flags & BTRFS_SEND_FLAG_VERSION) {
|
|
if (arg->version > BTRFS_SEND_STREAM_VERSION) {
|
|
ret = -EPROTO;
|
|
goto out;
|
|
}
|
|
/* Zero means "use the highest version" */
|
|
sctx->proto = arg->version ?: BTRFS_SEND_STREAM_VERSION;
|
|
} else {
|
|
sctx->proto = 1;
|
|
}
|
|
|
|
sctx->send_filp = fget(arg->send_fd);
|
|
if (!sctx->send_filp) {
|
|
ret = -EBADF;
|
|
goto out;
|
|
}
|
|
|
|
sctx->send_root = send_root;
|
|
/*
|
|
* Unlikely but possible, if the subvolume is marked for deletion but
|
|
* is slow to remove the directory entry, send can still be started
|
|
*/
|
|
if (btrfs_root_dead(sctx->send_root)) {
|
|
ret = -EPERM;
|
|
goto out;
|
|
}
|
|
|
|
sctx->clone_roots_cnt = arg->clone_sources_count;
|
|
|
|
sctx->send_max_size = BTRFS_SEND_BUF_SIZE;
|
|
sctx->send_buf = kvmalloc(sctx->send_max_size, GFP_KERNEL);
|
|
if (!sctx->send_buf) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
sctx->pending_dir_moves = RB_ROOT;
|
|
sctx->waiting_dir_moves = RB_ROOT;
|
|
sctx->orphan_dirs = RB_ROOT;
|
|
|
|
sctx->clone_roots = kvcalloc(sizeof(*sctx->clone_roots),
|
|
arg->clone_sources_count + 1,
|
|
GFP_KERNEL);
|
|
if (!sctx->clone_roots) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
alloc_size = array_size(sizeof(*arg->clone_sources),
|
|
arg->clone_sources_count);
|
|
|
|
if (arg->clone_sources_count) {
|
|
clone_sources_tmp = kvmalloc(alloc_size, GFP_KERNEL);
|
|
if (!clone_sources_tmp) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
ret = copy_from_user(clone_sources_tmp, arg->clone_sources,
|
|
alloc_size);
|
|
if (ret) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
|
|
for (i = 0; i < arg->clone_sources_count; i++) {
|
|
clone_root = btrfs_get_fs_root(fs_info,
|
|
clone_sources_tmp[i], true);
|
|
if (IS_ERR(clone_root)) {
|
|
ret = PTR_ERR(clone_root);
|
|
goto out;
|
|
}
|
|
spin_lock(&clone_root->root_item_lock);
|
|
if (!btrfs_root_readonly(clone_root) ||
|
|
btrfs_root_dead(clone_root)) {
|
|
spin_unlock(&clone_root->root_item_lock);
|
|
btrfs_put_root(clone_root);
|
|
ret = -EPERM;
|
|
goto out;
|
|
}
|
|
if (clone_root->dedupe_in_progress) {
|
|
dedupe_in_progress_warn(clone_root);
|
|
spin_unlock(&clone_root->root_item_lock);
|
|
btrfs_put_root(clone_root);
|
|
ret = -EAGAIN;
|
|
goto out;
|
|
}
|
|
clone_root->send_in_progress++;
|
|
spin_unlock(&clone_root->root_item_lock);
|
|
|
|
sctx->clone_roots[i].root = clone_root;
|
|
clone_sources_to_rollback = i + 1;
|
|
}
|
|
kvfree(clone_sources_tmp);
|
|
clone_sources_tmp = NULL;
|
|
}
|
|
|
|
if (arg->parent_root) {
|
|
sctx->parent_root = btrfs_get_fs_root(fs_info, arg->parent_root,
|
|
true);
|
|
if (IS_ERR(sctx->parent_root)) {
|
|
ret = PTR_ERR(sctx->parent_root);
|
|
goto out;
|
|
}
|
|
|
|
spin_lock(&sctx->parent_root->root_item_lock);
|
|
sctx->parent_root->send_in_progress++;
|
|
if (!btrfs_root_readonly(sctx->parent_root) ||
|
|
btrfs_root_dead(sctx->parent_root)) {
|
|
spin_unlock(&sctx->parent_root->root_item_lock);
|
|
ret = -EPERM;
|
|
goto out;
|
|
}
|
|
if (sctx->parent_root->dedupe_in_progress) {
|
|
dedupe_in_progress_warn(sctx->parent_root);
|
|
spin_unlock(&sctx->parent_root->root_item_lock);
|
|
ret = -EAGAIN;
|
|
goto out;
|
|
}
|
|
spin_unlock(&sctx->parent_root->root_item_lock);
|
|
}
|
|
|
|
/*
|
|
* Clones from send_root are allowed, but only if the clone source
|
|
* is behind the current send position. This is checked while searching
|
|
* for possible clone sources.
|
|
*/
|
|
sctx->clone_roots[sctx->clone_roots_cnt++].root =
|
|
btrfs_grab_root(sctx->send_root);
|
|
|
|
/* We do a bsearch later */
|
|
sort(sctx->clone_roots, sctx->clone_roots_cnt,
|
|
sizeof(*sctx->clone_roots), __clone_root_cmp_sort,
|
|
NULL);
|
|
sort_clone_roots = 1;
|
|
|
|
ret = flush_delalloc_roots(sctx);
|
|
if (ret)
|
|
goto out;
|
|
|
|
ret = ensure_commit_roots_uptodate(sctx);
|
|
if (ret)
|
|
goto out;
|
|
|
|
ret = send_subvol(sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
if (!(sctx->flags & BTRFS_SEND_FLAG_OMIT_END_CMD)) {
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_END);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = send_cmd(sctx);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
|
|
out:
|
|
WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->pending_dir_moves));
|
|
while (sctx && !RB_EMPTY_ROOT(&sctx->pending_dir_moves)) {
|
|
struct rb_node *n;
|
|
struct pending_dir_move *pm;
|
|
|
|
n = rb_first(&sctx->pending_dir_moves);
|
|
pm = rb_entry(n, struct pending_dir_move, node);
|
|
while (!list_empty(&pm->list)) {
|
|
struct pending_dir_move *pm2;
|
|
|
|
pm2 = list_first_entry(&pm->list,
|
|
struct pending_dir_move, list);
|
|
free_pending_move(sctx, pm2);
|
|
}
|
|
free_pending_move(sctx, pm);
|
|
}
|
|
|
|
WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->waiting_dir_moves));
|
|
while (sctx && !RB_EMPTY_ROOT(&sctx->waiting_dir_moves)) {
|
|
struct rb_node *n;
|
|
struct waiting_dir_move *dm;
|
|
|
|
n = rb_first(&sctx->waiting_dir_moves);
|
|
dm = rb_entry(n, struct waiting_dir_move, node);
|
|
rb_erase(&dm->node, &sctx->waiting_dir_moves);
|
|
kfree(dm);
|
|
}
|
|
|
|
WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->orphan_dirs));
|
|
while (sctx && !RB_EMPTY_ROOT(&sctx->orphan_dirs)) {
|
|
struct rb_node *n;
|
|
struct orphan_dir_info *odi;
|
|
|
|
n = rb_first(&sctx->orphan_dirs);
|
|
odi = rb_entry(n, struct orphan_dir_info, node);
|
|
free_orphan_dir_info(sctx, odi);
|
|
}
|
|
|
|
if (sort_clone_roots) {
|
|
for (i = 0; i < sctx->clone_roots_cnt; i++) {
|
|
btrfs_root_dec_send_in_progress(
|
|
sctx->clone_roots[i].root);
|
|
btrfs_put_root(sctx->clone_roots[i].root);
|
|
}
|
|
} else {
|
|
for (i = 0; sctx && i < clone_sources_to_rollback; i++) {
|
|
btrfs_root_dec_send_in_progress(
|
|
sctx->clone_roots[i].root);
|
|
btrfs_put_root(sctx->clone_roots[i].root);
|
|
}
|
|
|
|
btrfs_root_dec_send_in_progress(send_root);
|
|
}
|
|
if (sctx && !IS_ERR_OR_NULL(sctx->parent_root)) {
|
|
btrfs_root_dec_send_in_progress(sctx->parent_root);
|
|
btrfs_put_root(sctx->parent_root);
|
|
}
|
|
|
|
kvfree(clone_sources_tmp);
|
|
|
|
if (sctx) {
|
|
if (sctx->send_filp)
|
|
fput(sctx->send_filp);
|
|
|
|
kvfree(sctx->clone_roots);
|
|
kvfree(sctx->send_buf);
|
|
|
|
name_cache_free(sctx);
|
|
|
|
close_current_inode(sctx);
|
|
|
|
kfree(sctx);
|
|
}
|
|
|
|
return ret;
|
|
}
|