forked from Minki/linux
1dc51b8288
Pull more vfs updates from Al Viro: "Assorted VFS fixes and related cleanups (IMO the most interesting in that part are f_path-related things and Eric's descriptor-related stuff). UFS regression fixes (it got broken last cycle). 9P fixes. fs-cache series, DAX patches, Jan's file_remove_suid() work" [ I'd say this is much more than "fixes and related cleanups". The file_table locking rule change by Eric Dumazet is a rather big and fundamental update even if the patch isn't huge. - Linus ] * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits) 9p: cope with bogus responses from server in p9_client_{read,write} p9_client_write(): avoid double p9_free_req() 9p: forgetting to cancel request on interrupted zero-copy RPC dax: bdev_direct_access() may sleep block: Add support for DAX reads/writes to block devices dax: Use copy_from_iter_nocache dax: Add block size note to documentation fs/file.c: __fget() and dup2() atomicity rules fs/file.c: don't acquire files->file_lock in fd_install() fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation vfs: avoid creation of inode number 0 in get_next_ino namei: make set_root_rcu() return void make simple_positive() public ufs: use dir_pages instead of ufs_dir_pages() pagemap.h: move dir_pages() over there remove the pointless include of lglock.h fs: cleanup slight list_entry abuse xfs: Correctly lock inode when removing suid and file capabilities fs: Call security_ops->inode_killpriv on truncate fs: Provide function telling whether file_remove_privs() will do anything ...
1579 lines
41 KiB
C
1579 lines
41 KiB
C
/*
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* Copyright (c) 2000-2005 Silicon Graphics, Inc.
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* All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it would be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "xfs.h"
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#include "xfs_fs.h"
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#include "xfs_shared.h"
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#include "xfs_format.h"
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#include "xfs_log_format.h"
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#include "xfs_trans_resv.h"
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#include "xfs_mount.h"
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#include "xfs_da_format.h"
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#include "xfs_da_btree.h"
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#include "xfs_inode.h"
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#include "xfs_trans.h"
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#include "xfs_inode_item.h"
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#include "xfs_bmap.h"
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#include "xfs_bmap_util.h"
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#include "xfs_error.h"
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#include "xfs_dir2.h"
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#include "xfs_dir2_priv.h"
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#include "xfs_ioctl.h"
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#include "xfs_trace.h"
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#include "xfs_log.h"
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#include "xfs_icache.h"
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#include "xfs_pnfs.h"
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#include <linux/dcache.h>
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#include <linux/falloc.h>
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#include <linux/pagevec.h>
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#include <linux/backing-dev.h>
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static const struct vm_operations_struct xfs_file_vm_ops;
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/*
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* Locking primitives for read and write IO paths to ensure we consistently use
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* and order the inode->i_mutex, ip->i_lock and ip->i_iolock.
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*/
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static inline void
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xfs_rw_ilock(
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struct xfs_inode *ip,
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int type)
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{
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if (type & XFS_IOLOCK_EXCL)
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mutex_lock(&VFS_I(ip)->i_mutex);
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xfs_ilock(ip, type);
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}
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static inline void
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xfs_rw_iunlock(
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struct xfs_inode *ip,
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int type)
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{
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xfs_iunlock(ip, type);
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if (type & XFS_IOLOCK_EXCL)
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mutex_unlock(&VFS_I(ip)->i_mutex);
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}
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static inline void
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xfs_rw_ilock_demote(
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struct xfs_inode *ip,
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int type)
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{
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xfs_ilock_demote(ip, type);
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if (type & XFS_IOLOCK_EXCL)
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mutex_unlock(&VFS_I(ip)->i_mutex);
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}
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/*
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* xfs_iozero clears the specified range supplied via the page cache (except in
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* the DAX case). Writes through the page cache will allocate blocks over holes,
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* though the callers usually map the holes first and avoid them. If a block is
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* not completely zeroed, then it will be read from disk before being partially
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* zeroed.
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*
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* In the DAX case, we can just directly write to the underlying pages. This
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* will not allocate blocks, but will avoid holes and unwritten extents and so
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* not do unnecessary work.
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*/
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int
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xfs_iozero(
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struct xfs_inode *ip, /* inode */
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loff_t pos, /* offset in file */
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size_t count) /* size of data to zero */
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{
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struct page *page;
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struct address_space *mapping;
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int status = 0;
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mapping = VFS_I(ip)->i_mapping;
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do {
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unsigned offset, bytes;
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void *fsdata;
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offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
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bytes = PAGE_CACHE_SIZE - offset;
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if (bytes > count)
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bytes = count;
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if (IS_DAX(VFS_I(ip))) {
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status = dax_zero_page_range(VFS_I(ip), pos, bytes,
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xfs_get_blocks_direct);
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if (status)
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break;
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} else {
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status = pagecache_write_begin(NULL, mapping, pos, bytes,
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AOP_FLAG_UNINTERRUPTIBLE,
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&page, &fsdata);
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if (status)
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break;
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zero_user(page, offset, bytes);
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status = pagecache_write_end(NULL, mapping, pos, bytes,
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bytes, page, fsdata);
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WARN_ON(status <= 0); /* can't return less than zero! */
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status = 0;
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}
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pos += bytes;
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count -= bytes;
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} while (count);
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return status;
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}
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int
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xfs_update_prealloc_flags(
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struct xfs_inode *ip,
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enum xfs_prealloc_flags flags)
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{
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struct xfs_trans *tp;
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int error;
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tp = xfs_trans_alloc(ip->i_mount, XFS_TRANS_WRITEID);
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error = xfs_trans_reserve(tp, &M_RES(ip->i_mount)->tr_writeid, 0, 0);
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if (error) {
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xfs_trans_cancel(tp);
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return error;
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}
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xfs_ilock(ip, XFS_ILOCK_EXCL);
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xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
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if (!(flags & XFS_PREALLOC_INVISIBLE)) {
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ip->i_d.di_mode &= ~S_ISUID;
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if (ip->i_d.di_mode & S_IXGRP)
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ip->i_d.di_mode &= ~S_ISGID;
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xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
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}
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if (flags & XFS_PREALLOC_SET)
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ip->i_d.di_flags |= XFS_DIFLAG_PREALLOC;
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if (flags & XFS_PREALLOC_CLEAR)
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ip->i_d.di_flags &= ~XFS_DIFLAG_PREALLOC;
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xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
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if (flags & XFS_PREALLOC_SYNC)
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xfs_trans_set_sync(tp);
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return xfs_trans_commit(tp);
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}
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/*
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* Fsync operations on directories are much simpler than on regular files,
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* as there is no file data to flush, and thus also no need for explicit
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* cache flush operations, and there are no non-transaction metadata updates
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* on directories either.
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*/
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STATIC int
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xfs_dir_fsync(
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struct file *file,
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loff_t start,
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loff_t end,
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int datasync)
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{
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struct xfs_inode *ip = XFS_I(file->f_mapping->host);
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struct xfs_mount *mp = ip->i_mount;
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xfs_lsn_t lsn = 0;
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trace_xfs_dir_fsync(ip);
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xfs_ilock(ip, XFS_ILOCK_SHARED);
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if (xfs_ipincount(ip))
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lsn = ip->i_itemp->ili_last_lsn;
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xfs_iunlock(ip, XFS_ILOCK_SHARED);
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if (!lsn)
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return 0;
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return _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL);
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}
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STATIC int
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xfs_file_fsync(
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struct file *file,
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loff_t start,
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loff_t end,
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int datasync)
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{
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struct inode *inode = file->f_mapping->host;
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struct xfs_inode *ip = XFS_I(inode);
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struct xfs_mount *mp = ip->i_mount;
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int error = 0;
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int log_flushed = 0;
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xfs_lsn_t lsn = 0;
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trace_xfs_file_fsync(ip);
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error = filemap_write_and_wait_range(inode->i_mapping, start, end);
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if (error)
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return error;
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if (XFS_FORCED_SHUTDOWN(mp))
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return -EIO;
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xfs_iflags_clear(ip, XFS_ITRUNCATED);
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if (mp->m_flags & XFS_MOUNT_BARRIER) {
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/*
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* If we have an RT and/or log subvolume we need to make sure
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* to flush the write cache the device used for file data
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* first. This is to ensure newly written file data make
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* it to disk before logging the new inode size in case of
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* an extending write.
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*/
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if (XFS_IS_REALTIME_INODE(ip))
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xfs_blkdev_issue_flush(mp->m_rtdev_targp);
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else if (mp->m_logdev_targp != mp->m_ddev_targp)
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xfs_blkdev_issue_flush(mp->m_ddev_targp);
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}
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/*
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* All metadata updates are logged, which means that we just have
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* to flush the log up to the latest LSN that touched the inode.
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*/
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xfs_ilock(ip, XFS_ILOCK_SHARED);
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if (xfs_ipincount(ip)) {
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if (!datasync ||
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(ip->i_itemp->ili_fields & ~XFS_ILOG_TIMESTAMP))
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lsn = ip->i_itemp->ili_last_lsn;
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}
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xfs_iunlock(ip, XFS_ILOCK_SHARED);
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if (lsn)
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error = _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, &log_flushed);
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/*
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* If we only have a single device, and the log force about was
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* a no-op we might have to flush the data device cache here.
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* This can only happen for fdatasync/O_DSYNC if we were overwriting
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* an already allocated file and thus do not have any metadata to
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* commit.
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*/
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if ((mp->m_flags & XFS_MOUNT_BARRIER) &&
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mp->m_logdev_targp == mp->m_ddev_targp &&
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!XFS_IS_REALTIME_INODE(ip) &&
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!log_flushed)
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xfs_blkdev_issue_flush(mp->m_ddev_targp);
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return error;
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}
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STATIC ssize_t
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xfs_file_read_iter(
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struct kiocb *iocb,
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struct iov_iter *to)
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{
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struct file *file = iocb->ki_filp;
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struct inode *inode = file->f_mapping->host;
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struct xfs_inode *ip = XFS_I(inode);
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struct xfs_mount *mp = ip->i_mount;
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size_t size = iov_iter_count(to);
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ssize_t ret = 0;
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int ioflags = 0;
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xfs_fsize_t n;
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loff_t pos = iocb->ki_pos;
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XFS_STATS_INC(xs_read_calls);
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if (unlikely(iocb->ki_flags & IOCB_DIRECT))
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ioflags |= XFS_IO_ISDIRECT;
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if (file->f_mode & FMODE_NOCMTIME)
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ioflags |= XFS_IO_INVIS;
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if ((ioflags & XFS_IO_ISDIRECT) && !IS_DAX(inode)) {
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xfs_buftarg_t *target =
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XFS_IS_REALTIME_INODE(ip) ?
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mp->m_rtdev_targp : mp->m_ddev_targp;
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/* DIO must be aligned to device logical sector size */
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if ((pos | size) & target->bt_logical_sectormask) {
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if (pos == i_size_read(inode))
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return 0;
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return -EINVAL;
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}
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}
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n = mp->m_super->s_maxbytes - pos;
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if (n <= 0 || size == 0)
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return 0;
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if (n < size)
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size = n;
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if (XFS_FORCED_SHUTDOWN(mp))
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return -EIO;
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/*
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* Locking is a bit tricky here. If we take an exclusive lock
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* for direct IO, we effectively serialise all new concurrent
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* read IO to this file and block it behind IO that is currently in
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* progress because IO in progress holds the IO lock shared. We only
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* need to hold the lock exclusive to blow away the page cache, so
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* only take lock exclusively if the page cache needs invalidation.
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* This allows the normal direct IO case of no page cache pages to
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* proceeed concurrently without serialisation.
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*/
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xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
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if ((ioflags & XFS_IO_ISDIRECT) && inode->i_mapping->nrpages) {
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xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
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xfs_rw_ilock(ip, XFS_IOLOCK_EXCL);
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if (inode->i_mapping->nrpages) {
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ret = filemap_write_and_wait_range(
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VFS_I(ip)->i_mapping,
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pos, pos + size - 1);
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if (ret) {
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xfs_rw_iunlock(ip, XFS_IOLOCK_EXCL);
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return ret;
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}
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/*
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* Invalidate whole pages. This can return an error if
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* we fail to invalidate a page, but this should never
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* happen on XFS. Warn if it does fail.
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*/
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ret = invalidate_inode_pages2_range(VFS_I(ip)->i_mapping,
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pos >> PAGE_CACHE_SHIFT,
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(pos + size - 1) >> PAGE_CACHE_SHIFT);
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WARN_ON_ONCE(ret);
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ret = 0;
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}
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xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
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}
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trace_xfs_file_read(ip, size, pos, ioflags);
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ret = generic_file_read_iter(iocb, to);
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if (ret > 0)
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XFS_STATS_ADD(xs_read_bytes, ret);
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xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
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return ret;
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}
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STATIC ssize_t
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xfs_file_splice_read(
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struct file *infilp,
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loff_t *ppos,
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struct pipe_inode_info *pipe,
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size_t count,
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unsigned int flags)
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{
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struct xfs_inode *ip = XFS_I(infilp->f_mapping->host);
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int ioflags = 0;
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ssize_t ret;
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XFS_STATS_INC(xs_read_calls);
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if (infilp->f_mode & FMODE_NOCMTIME)
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ioflags |= XFS_IO_INVIS;
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|
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if (XFS_FORCED_SHUTDOWN(ip->i_mount))
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return -EIO;
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xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
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trace_xfs_file_splice_read(ip, count, *ppos, ioflags);
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|
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/* for dax, we need to avoid the page cache */
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if (IS_DAX(VFS_I(ip)))
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ret = default_file_splice_read(infilp, ppos, pipe, count, flags);
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else
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ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
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if (ret > 0)
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XFS_STATS_ADD(xs_read_bytes, ret);
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|
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xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
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return ret;
|
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}
|
|
|
|
/*
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* This routine is called to handle zeroing any space in the last block of the
|
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* file that is beyond the EOF. We do this since the size is being increased
|
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* without writing anything to that block and we don't want to read the
|
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* garbage on the disk.
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*/
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STATIC int /* error (positive) */
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xfs_zero_last_block(
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struct xfs_inode *ip,
|
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xfs_fsize_t offset,
|
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xfs_fsize_t isize,
|
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bool *did_zeroing)
|
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{
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struct xfs_mount *mp = ip->i_mount;
|
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xfs_fileoff_t last_fsb = XFS_B_TO_FSBT(mp, isize);
|
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int zero_offset = XFS_B_FSB_OFFSET(mp, isize);
|
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int zero_len;
|
|
int nimaps = 1;
|
|
int error = 0;
|
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struct xfs_bmbt_irec imap;
|
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|
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xfs_ilock(ip, XFS_ILOCK_EXCL);
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error = xfs_bmapi_read(ip, last_fsb, 1, &imap, &nimaps, 0);
|
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xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
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if (error)
|
|
return error;
|
|
|
|
ASSERT(nimaps > 0);
|
|
|
|
/*
|
|
* If the block underlying isize is just a hole, then there
|
|
* is nothing to zero.
|
|
*/
|
|
if (imap.br_startblock == HOLESTARTBLOCK)
|
|
return 0;
|
|
|
|
zero_len = mp->m_sb.sb_blocksize - zero_offset;
|
|
if (isize + zero_len > offset)
|
|
zero_len = offset - isize;
|
|
*did_zeroing = true;
|
|
return xfs_iozero(ip, isize, zero_len);
|
|
}
|
|
|
|
/*
|
|
* Zero any on disk space between the current EOF and the new, larger EOF.
|
|
*
|
|
* This handles the normal case of zeroing the remainder of the last block in
|
|
* the file and the unusual case of zeroing blocks out beyond the size of the
|
|
* file. This second case only happens with fixed size extents and when the
|
|
* system crashes before the inode size was updated but after blocks were
|
|
* allocated.
|
|
*
|
|
* Expects the iolock to be held exclusive, and will take the ilock internally.
|
|
*/
|
|
int /* error (positive) */
|
|
xfs_zero_eof(
|
|
struct xfs_inode *ip,
|
|
xfs_off_t offset, /* starting I/O offset */
|
|
xfs_fsize_t isize, /* current inode size */
|
|
bool *did_zeroing)
|
|
{
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
xfs_fileoff_t start_zero_fsb;
|
|
xfs_fileoff_t end_zero_fsb;
|
|
xfs_fileoff_t zero_count_fsb;
|
|
xfs_fileoff_t last_fsb;
|
|
xfs_fileoff_t zero_off;
|
|
xfs_fsize_t zero_len;
|
|
int nimaps;
|
|
int error = 0;
|
|
struct xfs_bmbt_irec imap;
|
|
|
|
ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
|
|
ASSERT(offset > isize);
|
|
|
|
/*
|
|
* First handle zeroing the block on which isize resides.
|
|
*
|
|
* We only zero a part of that block so it is handled specially.
|
|
*/
|
|
if (XFS_B_FSB_OFFSET(mp, isize) != 0) {
|
|
error = xfs_zero_last_block(ip, offset, isize, did_zeroing);
|
|
if (error)
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Calculate the range between the new size and the old where blocks
|
|
* needing to be zeroed may exist.
|
|
*
|
|
* To get the block where the last byte in the file currently resides,
|
|
* we need to subtract one from the size and truncate back to a block
|
|
* boundary. We subtract 1 in case the size is exactly on a block
|
|
* boundary.
|
|
*/
|
|
last_fsb = isize ? XFS_B_TO_FSBT(mp, isize - 1) : (xfs_fileoff_t)-1;
|
|
start_zero_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize);
|
|
end_zero_fsb = XFS_B_TO_FSBT(mp, offset - 1);
|
|
ASSERT((xfs_sfiloff_t)last_fsb < (xfs_sfiloff_t)start_zero_fsb);
|
|
if (last_fsb == end_zero_fsb) {
|
|
/*
|
|
* The size was only incremented on its last block.
|
|
* We took care of that above, so just return.
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
ASSERT(start_zero_fsb <= end_zero_fsb);
|
|
while (start_zero_fsb <= end_zero_fsb) {
|
|
nimaps = 1;
|
|
zero_count_fsb = end_zero_fsb - start_zero_fsb + 1;
|
|
|
|
xfs_ilock(ip, XFS_ILOCK_EXCL);
|
|
error = xfs_bmapi_read(ip, start_zero_fsb, zero_count_fsb,
|
|
&imap, &nimaps, 0);
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
|
if (error)
|
|
return error;
|
|
|
|
ASSERT(nimaps > 0);
|
|
|
|
if (imap.br_state == XFS_EXT_UNWRITTEN ||
|
|
imap.br_startblock == HOLESTARTBLOCK) {
|
|
start_zero_fsb = imap.br_startoff + imap.br_blockcount;
|
|
ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* There are blocks we need to zero.
|
|
*/
|
|
zero_off = XFS_FSB_TO_B(mp, start_zero_fsb);
|
|
zero_len = XFS_FSB_TO_B(mp, imap.br_blockcount);
|
|
|
|
if ((zero_off + zero_len) > offset)
|
|
zero_len = offset - zero_off;
|
|
|
|
error = xfs_iozero(ip, zero_off, zero_len);
|
|
if (error)
|
|
return error;
|
|
|
|
*did_zeroing = true;
|
|
start_zero_fsb = imap.br_startoff + imap.br_blockcount;
|
|
ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Common pre-write limit and setup checks.
|
|
*
|
|
* Called with the iolocked held either shared and exclusive according to
|
|
* @iolock, and returns with it held. Might upgrade the iolock to exclusive
|
|
* if called for a direct write beyond i_size.
|
|
*/
|
|
STATIC ssize_t
|
|
xfs_file_aio_write_checks(
|
|
struct kiocb *iocb,
|
|
struct iov_iter *from,
|
|
int *iolock)
|
|
{
|
|
struct file *file = iocb->ki_filp;
|
|
struct inode *inode = file->f_mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
ssize_t error = 0;
|
|
size_t count = iov_iter_count(from);
|
|
|
|
restart:
|
|
error = generic_write_checks(iocb, from);
|
|
if (error <= 0)
|
|
return error;
|
|
|
|
error = xfs_break_layouts(inode, iolock, true);
|
|
if (error)
|
|
return error;
|
|
|
|
/* For changing security info in file_remove_privs() we need i_mutex */
|
|
if (*iolock == XFS_IOLOCK_SHARED && !IS_NOSEC(inode)) {
|
|
xfs_rw_iunlock(ip, *iolock);
|
|
*iolock = XFS_IOLOCK_EXCL;
|
|
xfs_rw_ilock(ip, *iolock);
|
|
goto restart;
|
|
}
|
|
/*
|
|
* If the offset is beyond the size of the file, we need to zero any
|
|
* blocks that fall between the existing EOF and the start of this
|
|
* write. If zeroing is needed and we are currently holding the
|
|
* iolock shared, we need to update it to exclusive which implies
|
|
* having to redo all checks before.
|
|
*
|
|
* We need to serialise against EOF updates that occur in IO
|
|
* completions here. We want to make sure that nobody is changing the
|
|
* size while we do this check until we have placed an IO barrier (i.e.
|
|
* hold the XFS_IOLOCK_EXCL) that prevents new IO from being dispatched.
|
|
* The spinlock effectively forms a memory barrier once we have the
|
|
* XFS_IOLOCK_EXCL so we are guaranteed to see the latest EOF value
|
|
* and hence be able to correctly determine if we need to run zeroing.
|
|
*/
|
|
spin_lock(&ip->i_flags_lock);
|
|
if (iocb->ki_pos > i_size_read(inode)) {
|
|
bool zero = false;
|
|
|
|
spin_unlock(&ip->i_flags_lock);
|
|
if (*iolock == XFS_IOLOCK_SHARED) {
|
|
xfs_rw_iunlock(ip, *iolock);
|
|
*iolock = XFS_IOLOCK_EXCL;
|
|
xfs_rw_ilock(ip, *iolock);
|
|
iov_iter_reexpand(from, count);
|
|
|
|
/*
|
|
* We now have an IO submission barrier in place, but
|
|
* AIO can do EOF updates during IO completion and hence
|
|
* we now need to wait for all of them to drain. Non-AIO
|
|
* DIO will have drained before we are given the
|
|
* XFS_IOLOCK_EXCL, and so for most cases this wait is a
|
|
* no-op.
|
|
*/
|
|
inode_dio_wait(inode);
|
|
goto restart;
|
|
}
|
|
error = xfs_zero_eof(ip, iocb->ki_pos, i_size_read(inode), &zero);
|
|
if (error)
|
|
return error;
|
|
} else
|
|
spin_unlock(&ip->i_flags_lock);
|
|
|
|
/*
|
|
* Updating the timestamps will grab the ilock again from
|
|
* xfs_fs_dirty_inode, so we have to call it after dropping the
|
|
* lock above. Eventually we should look into a way to avoid
|
|
* the pointless lock roundtrip.
|
|
*/
|
|
if (likely(!(file->f_mode & FMODE_NOCMTIME))) {
|
|
error = file_update_time(file);
|
|
if (error)
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* If we're writing the file then make sure to clear the setuid and
|
|
* setgid bits if the process is not being run by root. This keeps
|
|
* people from modifying setuid and setgid binaries.
|
|
*/
|
|
if (!IS_NOSEC(inode))
|
|
return file_remove_privs(file);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* xfs_file_dio_aio_write - handle direct IO writes
|
|
*
|
|
* Lock the inode appropriately to prepare for and issue a direct IO write.
|
|
* By separating it from the buffered write path we remove all the tricky to
|
|
* follow locking changes and looping.
|
|
*
|
|
* If there are cached pages or we're extending the file, we need IOLOCK_EXCL
|
|
* until we're sure the bytes at the new EOF have been zeroed and/or the cached
|
|
* pages are flushed out.
|
|
*
|
|
* In most cases the direct IO writes will be done holding IOLOCK_SHARED
|
|
* allowing them to be done in parallel with reads and other direct IO writes.
|
|
* However, if the IO is not aligned to filesystem blocks, the direct IO layer
|
|
* needs to do sub-block zeroing and that requires serialisation against other
|
|
* direct IOs to the same block. In this case we need to serialise the
|
|
* submission of the unaligned IOs so that we don't get racing block zeroing in
|
|
* the dio layer. To avoid the problem with aio, we also need to wait for
|
|
* outstanding IOs to complete so that unwritten extent conversion is completed
|
|
* before we try to map the overlapping block. This is currently implemented by
|
|
* hitting it with a big hammer (i.e. inode_dio_wait()).
|
|
*
|
|
* Returns with locks held indicated by @iolock and errors indicated by
|
|
* negative return values.
|
|
*/
|
|
STATIC ssize_t
|
|
xfs_file_dio_aio_write(
|
|
struct kiocb *iocb,
|
|
struct iov_iter *from)
|
|
{
|
|
struct file *file = iocb->ki_filp;
|
|
struct address_space *mapping = file->f_mapping;
|
|
struct inode *inode = mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
ssize_t ret = 0;
|
|
int unaligned_io = 0;
|
|
int iolock;
|
|
size_t count = iov_iter_count(from);
|
|
loff_t pos = iocb->ki_pos;
|
|
loff_t end;
|
|
struct iov_iter data;
|
|
struct xfs_buftarg *target = XFS_IS_REALTIME_INODE(ip) ?
|
|
mp->m_rtdev_targp : mp->m_ddev_targp;
|
|
|
|
/* DIO must be aligned to device logical sector size */
|
|
if (!IS_DAX(inode) && ((pos | count) & target->bt_logical_sectormask))
|
|
return -EINVAL;
|
|
|
|
/* "unaligned" here means not aligned to a filesystem block */
|
|
if ((pos & mp->m_blockmask) || ((pos + count) & mp->m_blockmask))
|
|
unaligned_io = 1;
|
|
|
|
/*
|
|
* We don't need to take an exclusive lock unless there page cache needs
|
|
* to be invalidated or unaligned IO is being executed. We don't need to
|
|
* consider the EOF extension case here because
|
|
* xfs_file_aio_write_checks() will relock the inode as necessary for
|
|
* EOF zeroing cases and fill out the new inode size as appropriate.
|
|
*/
|
|
if (unaligned_io || mapping->nrpages)
|
|
iolock = XFS_IOLOCK_EXCL;
|
|
else
|
|
iolock = XFS_IOLOCK_SHARED;
|
|
xfs_rw_ilock(ip, iolock);
|
|
|
|
/*
|
|
* Recheck if there are cached pages that need invalidate after we got
|
|
* the iolock to protect against other threads adding new pages while
|
|
* we were waiting for the iolock.
|
|
*/
|
|
if (mapping->nrpages && iolock == XFS_IOLOCK_SHARED) {
|
|
xfs_rw_iunlock(ip, iolock);
|
|
iolock = XFS_IOLOCK_EXCL;
|
|
xfs_rw_ilock(ip, iolock);
|
|
}
|
|
|
|
ret = xfs_file_aio_write_checks(iocb, from, &iolock);
|
|
if (ret)
|
|
goto out;
|
|
count = iov_iter_count(from);
|
|
pos = iocb->ki_pos;
|
|
end = pos + count - 1;
|
|
|
|
if (mapping->nrpages) {
|
|
ret = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
|
|
pos, end);
|
|
if (ret)
|
|
goto out;
|
|
/*
|
|
* Invalidate whole pages. This can return an error if
|
|
* we fail to invalidate a page, but this should never
|
|
* happen on XFS. Warn if it does fail.
|
|
*/
|
|
ret = invalidate_inode_pages2_range(VFS_I(ip)->i_mapping,
|
|
pos >> PAGE_CACHE_SHIFT,
|
|
end >> PAGE_CACHE_SHIFT);
|
|
WARN_ON_ONCE(ret);
|
|
ret = 0;
|
|
}
|
|
|
|
/*
|
|
* If we are doing unaligned IO, wait for all other IO to drain,
|
|
* otherwise demote the lock if we had to flush cached pages
|
|
*/
|
|
if (unaligned_io)
|
|
inode_dio_wait(inode);
|
|
else if (iolock == XFS_IOLOCK_EXCL) {
|
|
xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
|
|
iolock = XFS_IOLOCK_SHARED;
|
|
}
|
|
|
|
trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0);
|
|
|
|
data = *from;
|
|
ret = mapping->a_ops->direct_IO(iocb, &data, pos);
|
|
|
|
/* see generic_file_direct_write() for why this is necessary */
|
|
if (mapping->nrpages) {
|
|
invalidate_inode_pages2_range(mapping,
|
|
pos >> PAGE_CACHE_SHIFT,
|
|
end >> PAGE_CACHE_SHIFT);
|
|
}
|
|
|
|
if (ret > 0) {
|
|
pos += ret;
|
|
iov_iter_advance(from, ret);
|
|
iocb->ki_pos = pos;
|
|
}
|
|
out:
|
|
xfs_rw_iunlock(ip, iolock);
|
|
|
|
/*
|
|
* No fallback to buffered IO on errors for XFS. DAX can result in
|
|
* partial writes, but direct IO will either complete fully or fail.
|
|
*/
|
|
ASSERT(ret < 0 || ret == count || IS_DAX(VFS_I(ip)));
|
|
return ret;
|
|
}
|
|
|
|
STATIC ssize_t
|
|
xfs_file_buffered_aio_write(
|
|
struct kiocb *iocb,
|
|
struct iov_iter *from)
|
|
{
|
|
struct file *file = iocb->ki_filp;
|
|
struct address_space *mapping = file->f_mapping;
|
|
struct inode *inode = mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
ssize_t ret;
|
|
int enospc = 0;
|
|
int iolock = XFS_IOLOCK_EXCL;
|
|
|
|
xfs_rw_ilock(ip, iolock);
|
|
|
|
ret = xfs_file_aio_write_checks(iocb, from, &iolock);
|
|
if (ret)
|
|
goto out;
|
|
|
|
/* We can write back this queue in page reclaim */
|
|
current->backing_dev_info = inode_to_bdi(inode);
|
|
|
|
write_retry:
|
|
trace_xfs_file_buffered_write(ip, iov_iter_count(from),
|
|
iocb->ki_pos, 0);
|
|
ret = generic_perform_write(file, from, iocb->ki_pos);
|
|
if (likely(ret >= 0))
|
|
iocb->ki_pos += ret;
|
|
|
|
/*
|
|
* If we hit a space limit, try to free up some lingering preallocated
|
|
* space before returning an error. In the case of ENOSPC, first try to
|
|
* write back all dirty inodes to free up some of the excess reserved
|
|
* metadata space. This reduces the chances that the eofblocks scan
|
|
* waits on dirty mappings. Since xfs_flush_inodes() is serialized, this
|
|
* also behaves as a filter to prevent too many eofblocks scans from
|
|
* running at the same time.
|
|
*/
|
|
if (ret == -EDQUOT && !enospc) {
|
|
enospc = xfs_inode_free_quota_eofblocks(ip);
|
|
if (enospc)
|
|
goto write_retry;
|
|
} else if (ret == -ENOSPC && !enospc) {
|
|
struct xfs_eofblocks eofb = {0};
|
|
|
|
enospc = 1;
|
|
xfs_flush_inodes(ip->i_mount);
|
|
eofb.eof_scan_owner = ip->i_ino; /* for locking */
|
|
eofb.eof_flags = XFS_EOF_FLAGS_SYNC;
|
|
xfs_icache_free_eofblocks(ip->i_mount, &eofb);
|
|
goto write_retry;
|
|
}
|
|
|
|
current->backing_dev_info = NULL;
|
|
out:
|
|
xfs_rw_iunlock(ip, iolock);
|
|
return ret;
|
|
}
|
|
|
|
STATIC ssize_t
|
|
xfs_file_write_iter(
|
|
struct kiocb *iocb,
|
|
struct iov_iter *from)
|
|
{
|
|
struct file *file = iocb->ki_filp;
|
|
struct address_space *mapping = file->f_mapping;
|
|
struct inode *inode = mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
ssize_t ret;
|
|
size_t ocount = iov_iter_count(from);
|
|
|
|
XFS_STATS_INC(xs_write_calls);
|
|
|
|
if (ocount == 0)
|
|
return 0;
|
|
|
|
if (XFS_FORCED_SHUTDOWN(ip->i_mount))
|
|
return -EIO;
|
|
|
|
if ((iocb->ki_flags & IOCB_DIRECT) || IS_DAX(inode))
|
|
ret = xfs_file_dio_aio_write(iocb, from);
|
|
else
|
|
ret = xfs_file_buffered_aio_write(iocb, from);
|
|
|
|
if (ret > 0) {
|
|
ssize_t err;
|
|
|
|
XFS_STATS_ADD(xs_write_bytes, ret);
|
|
|
|
/* Handle various SYNC-type writes */
|
|
err = generic_write_sync(file, iocb->ki_pos - ret, ret);
|
|
if (err < 0)
|
|
ret = err;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
#define XFS_FALLOC_FL_SUPPORTED \
|
|
(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \
|
|
FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | \
|
|
FALLOC_FL_INSERT_RANGE)
|
|
|
|
STATIC long
|
|
xfs_file_fallocate(
|
|
struct file *file,
|
|
int mode,
|
|
loff_t offset,
|
|
loff_t len)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
long error;
|
|
enum xfs_prealloc_flags flags = 0;
|
|
uint iolock = XFS_IOLOCK_EXCL;
|
|
loff_t new_size = 0;
|
|
bool do_file_insert = 0;
|
|
|
|
if (!S_ISREG(inode->i_mode))
|
|
return -EINVAL;
|
|
if (mode & ~XFS_FALLOC_FL_SUPPORTED)
|
|
return -EOPNOTSUPP;
|
|
|
|
xfs_ilock(ip, iolock);
|
|
error = xfs_break_layouts(inode, &iolock, false);
|
|
if (error)
|
|
goto out_unlock;
|
|
|
|
xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
|
|
iolock |= XFS_MMAPLOCK_EXCL;
|
|
|
|
if (mode & FALLOC_FL_PUNCH_HOLE) {
|
|
error = xfs_free_file_space(ip, offset, len);
|
|
if (error)
|
|
goto out_unlock;
|
|
} else if (mode & FALLOC_FL_COLLAPSE_RANGE) {
|
|
unsigned blksize_mask = (1 << inode->i_blkbits) - 1;
|
|
|
|
if (offset & blksize_mask || len & blksize_mask) {
|
|
error = -EINVAL;
|
|
goto out_unlock;
|
|
}
|
|
|
|
/*
|
|
* There is no need to overlap collapse range with EOF,
|
|
* in which case it is effectively a truncate operation
|
|
*/
|
|
if (offset + len >= i_size_read(inode)) {
|
|
error = -EINVAL;
|
|
goto out_unlock;
|
|
}
|
|
|
|
new_size = i_size_read(inode) - len;
|
|
|
|
error = xfs_collapse_file_space(ip, offset, len);
|
|
if (error)
|
|
goto out_unlock;
|
|
} else if (mode & FALLOC_FL_INSERT_RANGE) {
|
|
unsigned blksize_mask = (1 << inode->i_blkbits) - 1;
|
|
|
|
new_size = i_size_read(inode) + len;
|
|
if (offset & blksize_mask || len & blksize_mask) {
|
|
error = -EINVAL;
|
|
goto out_unlock;
|
|
}
|
|
|
|
/* check the new inode size does not wrap through zero */
|
|
if (new_size > inode->i_sb->s_maxbytes) {
|
|
error = -EFBIG;
|
|
goto out_unlock;
|
|
}
|
|
|
|
/* Offset should be less than i_size */
|
|
if (offset >= i_size_read(inode)) {
|
|
error = -EINVAL;
|
|
goto out_unlock;
|
|
}
|
|
do_file_insert = 1;
|
|
} else {
|
|
flags |= XFS_PREALLOC_SET;
|
|
|
|
if (!(mode & FALLOC_FL_KEEP_SIZE) &&
|
|
offset + len > i_size_read(inode)) {
|
|
new_size = offset + len;
|
|
error = inode_newsize_ok(inode, new_size);
|
|
if (error)
|
|
goto out_unlock;
|
|
}
|
|
|
|
if (mode & FALLOC_FL_ZERO_RANGE)
|
|
error = xfs_zero_file_space(ip, offset, len);
|
|
else
|
|
error = xfs_alloc_file_space(ip, offset, len,
|
|
XFS_BMAPI_PREALLOC);
|
|
if (error)
|
|
goto out_unlock;
|
|
}
|
|
|
|
if (file->f_flags & O_DSYNC)
|
|
flags |= XFS_PREALLOC_SYNC;
|
|
|
|
error = xfs_update_prealloc_flags(ip, flags);
|
|
if (error)
|
|
goto out_unlock;
|
|
|
|
/* Change file size if needed */
|
|
if (new_size) {
|
|
struct iattr iattr;
|
|
|
|
iattr.ia_valid = ATTR_SIZE;
|
|
iattr.ia_size = new_size;
|
|
error = xfs_setattr_size(ip, &iattr);
|
|
if (error)
|
|
goto out_unlock;
|
|
}
|
|
|
|
/*
|
|
* Perform hole insertion now that the file size has been
|
|
* updated so that if we crash during the operation we don't
|
|
* leave shifted extents past EOF and hence losing access to
|
|
* the data that is contained within them.
|
|
*/
|
|
if (do_file_insert)
|
|
error = xfs_insert_file_space(ip, offset, len);
|
|
|
|
out_unlock:
|
|
xfs_iunlock(ip, iolock);
|
|
return error;
|
|
}
|
|
|
|
|
|
STATIC int
|
|
xfs_file_open(
|
|
struct inode *inode,
|
|
struct file *file)
|
|
{
|
|
if (!(file->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
|
|
return -EFBIG;
|
|
if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb)))
|
|
return -EIO;
|
|
return 0;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_dir_open(
|
|
struct inode *inode,
|
|
struct file *file)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
int mode;
|
|
int error;
|
|
|
|
error = xfs_file_open(inode, file);
|
|
if (error)
|
|
return error;
|
|
|
|
/*
|
|
* If there are any blocks, read-ahead block 0 as we're almost
|
|
* certain to have the next operation be a read there.
|
|
*/
|
|
mode = xfs_ilock_data_map_shared(ip);
|
|
if (ip->i_d.di_nextents > 0)
|
|
xfs_dir3_data_readahead(ip, 0, -1);
|
|
xfs_iunlock(ip, mode);
|
|
return 0;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_file_release(
|
|
struct inode *inode,
|
|
struct file *filp)
|
|
{
|
|
return xfs_release(XFS_I(inode));
|
|
}
|
|
|
|
STATIC int
|
|
xfs_file_readdir(
|
|
struct file *file,
|
|
struct dir_context *ctx)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
xfs_inode_t *ip = XFS_I(inode);
|
|
size_t bufsize;
|
|
|
|
/*
|
|
* The Linux API doesn't pass down the total size of the buffer
|
|
* we read into down to the filesystem. With the filldir concept
|
|
* it's not needed for correct information, but the XFS dir2 leaf
|
|
* code wants an estimate of the buffer size to calculate it's
|
|
* readahead window and size the buffers used for mapping to
|
|
* physical blocks.
|
|
*
|
|
* Try to give it an estimate that's good enough, maybe at some
|
|
* point we can change the ->readdir prototype to include the
|
|
* buffer size. For now we use the current glibc buffer size.
|
|
*/
|
|
bufsize = (size_t)min_t(loff_t, 32768, ip->i_d.di_size);
|
|
|
|
return xfs_readdir(ip, ctx, bufsize);
|
|
}
|
|
|
|
/*
|
|
* This type is designed to indicate the type of offset we would like
|
|
* to search from page cache for xfs_seek_hole_data().
|
|
*/
|
|
enum {
|
|
HOLE_OFF = 0,
|
|
DATA_OFF,
|
|
};
|
|
|
|
/*
|
|
* Lookup the desired type of offset from the given page.
|
|
*
|
|
* On success, return true and the offset argument will point to the
|
|
* start of the region that was found. Otherwise this function will
|
|
* return false and keep the offset argument unchanged.
|
|
*/
|
|
STATIC bool
|
|
xfs_lookup_buffer_offset(
|
|
struct page *page,
|
|
loff_t *offset,
|
|
unsigned int type)
|
|
{
|
|
loff_t lastoff = page_offset(page);
|
|
bool found = false;
|
|
struct buffer_head *bh, *head;
|
|
|
|
bh = head = page_buffers(page);
|
|
do {
|
|
/*
|
|
* Unwritten extents that have data in the page
|
|
* cache covering them can be identified by the
|
|
* BH_Unwritten state flag. Pages with multiple
|
|
* buffers might have a mix of holes, data and
|
|
* unwritten extents - any buffer with valid
|
|
* data in it should have BH_Uptodate flag set
|
|
* on it.
|
|
*/
|
|
if (buffer_unwritten(bh) ||
|
|
buffer_uptodate(bh)) {
|
|
if (type == DATA_OFF)
|
|
found = true;
|
|
} else {
|
|
if (type == HOLE_OFF)
|
|
found = true;
|
|
}
|
|
|
|
if (found) {
|
|
*offset = lastoff;
|
|
break;
|
|
}
|
|
lastoff += bh->b_size;
|
|
} while ((bh = bh->b_this_page) != head);
|
|
|
|
return found;
|
|
}
|
|
|
|
/*
|
|
* This routine is called to find out and return a data or hole offset
|
|
* from the page cache for unwritten extents according to the desired
|
|
* type for xfs_seek_hole_data().
|
|
*
|
|
* The argument offset is used to tell where we start to search from the
|
|
* page cache. Map is used to figure out the end points of the range to
|
|
* lookup pages.
|
|
*
|
|
* Return true if the desired type of offset was found, and the argument
|
|
* offset is filled with that address. Otherwise, return false and keep
|
|
* offset unchanged.
|
|
*/
|
|
STATIC bool
|
|
xfs_find_get_desired_pgoff(
|
|
struct inode *inode,
|
|
struct xfs_bmbt_irec *map,
|
|
unsigned int type,
|
|
loff_t *offset)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
struct pagevec pvec;
|
|
pgoff_t index;
|
|
pgoff_t end;
|
|
loff_t endoff;
|
|
loff_t startoff = *offset;
|
|
loff_t lastoff = startoff;
|
|
bool found = false;
|
|
|
|
pagevec_init(&pvec, 0);
|
|
|
|
index = startoff >> PAGE_CACHE_SHIFT;
|
|
endoff = XFS_FSB_TO_B(mp, map->br_startoff + map->br_blockcount);
|
|
end = endoff >> PAGE_CACHE_SHIFT;
|
|
do {
|
|
int want;
|
|
unsigned nr_pages;
|
|
unsigned int i;
|
|
|
|
want = min_t(pgoff_t, end - index, PAGEVEC_SIZE);
|
|
nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index,
|
|
want);
|
|
/*
|
|
* No page mapped into given range. If we are searching holes
|
|
* and if this is the first time we got into the loop, it means
|
|
* that the given offset is landed in a hole, return it.
|
|
*
|
|
* If we have already stepped through some block buffers to find
|
|
* holes but they all contains data. In this case, the last
|
|
* offset is already updated and pointed to the end of the last
|
|
* mapped page, if it does not reach the endpoint to search,
|
|
* that means there should be a hole between them.
|
|
*/
|
|
if (nr_pages == 0) {
|
|
/* Data search found nothing */
|
|
if (type == DATA_OFF)
|
|
break;
|
|
|
|
ASSERT(type == HOLE_OFF);
|
|
if (lastoff == startoff || lastoff < endoff) {
|
|
found = true;
|
|
*offset = lastoff;
|
|
}
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* At lease we found one page. If this is the first time we
|
|
* step into the loop, and if the first page index offset is
|
|
* greater than the given search offset, a hole was found.
|
|
*/
|
|
if (type == HOLE_OFF && lastoff == startoff &&
|
|
lastoff < page_offset(pvec.pages[0])) {
|
|
found = true;
|
|
break;
|
|
}
|
|
|
|
for (i = 0; i < nr_pages; i++) {
|
|
struct page *page = pvec.pages[i];
|
|
loff_t b_offset;
|
|
|
|
/*
|
|
* At this point, the page may be truncated or
|
|
* invalidated (changing page->mapping to NULL),
|
|
* or even swizzled back from swapper_space to tmpfs
|
|
* file mapping. However, page->index will not change
|
|
* because we have a reference on the page.
|
|
*
|
|
* Searching done if the page index is out of range.
|
|
* If the current offset is not reaches the end of
|
|
* the specified search range, there should be a hole
|
|
* between them.
|
|
*/
|
|
if (page->index > end) {
|
|
if (type == HOLE_OFF && lastoff < endoff) {
|
|
*offset = lastoff;
|
|
found = true;
|
|
}
|
|
goto out;
|
|
}
|
|
|
|
lock_page(page);
|
|
/*
|
|
* Page truncated or invalidated(page->mapping == NULL).
|
|
* We can freely skip it and proceed to check the next
|
|
* page.
|
|
*/
|
|
if (unlikely(page->mapping != inode->i_mapping)) {
|
|
unlock_page(page);
|
|
continue;
|
|
}
|
|
|
|
if (!page_has_buffers(page)) {
|
|
unlock_page(page);
|
|
continue;
|
|
}
|
|
|
|
found = xfs_lookup_buffer_offset(page, &b_offset, type);
|
|
if (found) {
|
|
/*
|
|
* The found offset may be less than the start
|
|
* point to search if this is the first time to
|
|
* come here.
|
|
*/
|
|
*offset = max_t(loff_t, startoff, b_offset);
|
|
unlock_page(page);
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* We either searching data but nothing was found, or
|
|
* searching hole but found a data buffer. In either
|
|
* case, probably the next page contains the desired
|
|
* things, update the last offset to it so.
|
|
*/
|
|
lastoff = page_offset(page) + PAGE_SIZE;
|
|
unlock_page(page);
|
|
}
|
|
|
|
/*
|
|
* The number of returned pages less than our desired, search
|
|
* done. In this case, nothing was found for searching data,
|
|
* but we found a hole behind the last offset.
|
|
*/
|
|
if (nr_pages < want) {
|
|
if (type == HOLE_OFF) {
|
|
*offset = lastoff;
|
|
found = true;
|
|
}
|
|
break;
|
|
}
|
|
|
|
index = pvec.pages[i - 1]->index + 1;
|
|
pagevec_release(&pvec);
|
|
} while (index <= end);
|
|
|
|
out:
|
|
pagevec_release(&pvec);
|
|
return found;
|
|
}
|
|
|
|
STATIC loff_t
|
|
xfs_seek_hole_data(
|
|
struct file *file,
|
|
loff_t start,
|
|
int whence)
|
|
{
|
|
struct inode *inode = file->f_mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
loff_t uninitialized_var(offset);
|
|
xfs_fsize_t isize;
|
|
xfs_fileoff_t fsbno;
|
|
xfs_filblks_t end;
|
|
uint lock;
|
|
int error;
|
|
|
|
if (XFS_FORCED_SHUTDOWN(mp))
|
|
return -EIO;
|
|
|
|
lock = xfs_ilock_data_map_shared(ip);
|
|
|
|
isize = i_size_read(inode);
|
|
if (start >= isize) {
|
|
error = -ENXIO;
|
|
goto out_unlock;
|
|
}
|
|
|
|
/*
|
|
* Try to read extents from the first block indicated
|
|
* by fsbno to the end block of the file.
|
|
*/
|
|
fsbno = XFS_B_TO_FSBT(mp, start);
|
|
end = XFS_B_TO_FSB(mp, isize);
|
|
|
|
for (;;) {
|
|
struct xfs_bmbt_irec map[2];
|
|
int nmap = 2;
|
|
unsigned int i;
|
|
|
|
error = xfs_bmapi_read(ip, fsbno, end - fsbno, map, &nmap,
|
|
XFS_BMAPI_ENTIRE);
|
|
if (error)
|
|
goto out_unlock;
|
|
|
|
/* No extents at given offset, must be beyond EOF */
|
|
if (nmap == 0) {
|
|
error = -ENXIO;
|
|
goto out_unlock;
|
|
}
|
|
|
|
for (i = 0; i < nmap; i++) {
|
|
offset = max_t(loff_t, start,
|
|
XFS_FSB_TO_B(mp, map[i].br_startoff));
|
|
|
|
/* Landed in the hole we wanted? */
|
|
if (whence == SEEK_HOLE &&
|
|
map[i].br_startblock == HOLESTARTBLOCK)
|
|
goto out;
|
|
|
|
/* Landed in the data extent we wanted? */
|
|
if (whence == SEEK_DATA &&
|
|
(map[i].br_startblock == DELAYSTARTBLOCK ||
|
|
(map[i].br_state == XFS_EXT_NORM &&
|
|
!isnullstartblock(map[i].br_startblock))))
|
|
goto out;
|
|
|
|
/*
|
|
* Landed in an unwritten extent, try to search
|
|
* for hole or data from page cache.
|
|
*/
|
|
if (map[i].br_state == XFS_EXT_UNWRITTEN) {
|
|
if (xfs_find_get_desired_pgoff(inode, &map[i],
|
|
whence == SEEK_HOLE ? HOLE_OFF : DATA_OFF,
|
|
&offset))
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We only received one extent out of the two requested. This
|
|
* means we've hit EOF and didn't find what we are looking for.
|
|
*/
|
|
if (nmap == 1) {
|
|
/*
|
|
* If we were looking for a hole, set offset to
|
|
* the end of the file (i.e., there is an implicit
|
|
* hole at the end of any file).
|
|
*/
|
|
if (whence == SEEK_HOLE) {
|
|
offset = isize;
|
|
break;
|
|
}
|
|
/*
|
|
* If we were looking for data, it's nowhere to be found
|
|
*/
|
|
ASSERT(whence == SEEK_DATA);
|
|
error = -ENXIO;
|
|
goto out_unlock;
|
|
}
|
|
|
|
ASSERT(i > 1);
|
|
|
|
/*
|
|
* Nothing was found, proceed to the next round of search
|
|
* if the next reading offset is not at or beyond EOF.
|
|
*/
|
|
fsbno = map[i - 1].br_startoff + map[i - 1].br_blockcount;
|
|
start = XFS_FSB_TO_B(mp, fsbno);
|
|
if (start >= isize) {
|
|
if (whence == SEEK_HOLE) {
|
|
offset = isize;
|
|
break;
|
|
}
|
|
ASSERT(whence == SEEK_DATA);
|
|
error = -ENXIO;
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
|
|
out:
|
|
/*
|
|
* If at this point we have found the hole we wanted, the returned
|
|
* offset may be bigger than the file size as it may be aligned to
|
|
* page boundary for unwritten extents. We need to deal with this
|
|
* situation in particular.
|
|
*/
|
|
if (whence == SEEK_HOLE)
|
|
offset = min_t(loff_t, offset, isize);
|
|
offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
|
|
|
|
out_unlock:
|
|
xfs_iunlock(ip, lock);
|
|
|
|
if (error)
|
|
return error;
|
|
return offset;
|
|
}
|
|
|
|
STATIC loff_t
|
|
xfs_file_llseek(
|
|
struct file *file,
|
|
loff_t offset,
|
|
int whence)
|
|
{
|
|
switch (whence) {
|
|
case SEEK_END:
|
|
case SEEK_CUR:
|
|
case SEEK_SET:
|
|
return generic_file_llseek(file, offset, whence);
|
|
case SEEK_HOLE:
|
|
case SEEK_DATA:
|
|
return xfs_seek_hole_data(file, offset, whence);
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Locking for serialisation of IO during page faults. This results in a lock
|
|
* ordering of:
|
|
*
|
|
* mmap_sem (MM)
|
|
* sb_start_pagefault(vfs, freeze)
|
|
* i_mmap_lock (XFS - truncate serialisation)
|
|
* page_lock (MM)
|
|
* i_lock (XFS - extent map serialisation)
|
|
*/
|
|
|
|
/*
|
|
* mmap()d file has taken write protection fault and is being made writable. We
|
|
* can set the page state up correctly for a writable page, which means we can
|
|
* do correct delalloc accounting (ENOSPC checking!) and unwritten extent
|
|
* mapping.
|
|
*/
|
|
STATIC int
|
|
xfs_filemap_page_mkwrite(
|
|
struct vm_area_struct *vma,
|
|
struct vm_fault *vmf)
|
|
{
|
|
struct inode *inode = file_inode(vma->vm_file);
|
|
int ret;
|
|
|
|
trace_xfs_filemap_page_mkwrite(XFS_I(inode));
|
|
|
|
sb_start_pagefault(inode->i_sb);
|
|
file_update_time(vma->vm_file);
|
|
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
|
|
|
|
if (IS_DAX(inode)) {
|
|
ret = __dax_mkwrite(vma, vmf, xfs_get_blocks_direct,
|
|
xfs_end_io_dax_write);
|
|
} else {
|
|
ret = __block_page_mkwrite(vma, vmf, xfs_get_blocks);
|
|
ret = block_page_mkwrite_return(ret);
|
|
}
|
|
|
|
xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
|
|
sb_end_pagefault(inode->i_sb);
|
|
|
|
return ret;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_filemap_fault(
|
|
struct vm_area_struct *vma,
|
|
struct vm_fault *vmf)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(file_inode(vma->vm_file));
|
|
int ret;
|
|
|
|
trace_xfs_filemap_fault(ip);
|
|
|
|
/* DAX can shortcut the normal fault path on write faults! */
|
|
if ((vmf->flags & FAULT_FLAG_WRITE) && IS_DAX(VFS_I(ip)))
|
|
return xfs_filemap_page_mkwrite(vma, vmf);
|
|
|
|
xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
|
|
ret = filemap_fault(vma, vmf);
|
|
xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static const struct vm_operations_struct xfs_file_vm_ops = {
|
|
.fault = xfs_filemap_fault,
|
|
.map_pages = filemap_map_pages,
|
|
.page_mkwrite = xfs_filemap_page_mkwrite,
|
|
};
|
|
|
|
STATIC int
|
|
xfs_file_mmap(
|
|
struct file *filp,
|
|
struct vm_area_struct *vma)
|
|
{
|
|
file_accessed(filp);
|
|
vma->vm_ops = &xfs_file_vm_ops;
|
|
if (IS_DAX(file_inode(filp)))
|
|
vma->vm_flags |= VM_MIXEDMAP;
|
|
return 0;
|
|
}
|
|
|
|
const struct file_operations xfs_file_operations = {
|
|
.llseek = xfs_file_llseek,
|
|
.read_iter = xfs_file_read_iter,
|
|
.write_iter = xfs_file_write_iter,
|
|
.splice_read = xfs_file_splice_read,
|
|
.splice_write = iter_file_splice_write,
|
|
.unlocked_ioctl = xfs_file_ioctl,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = xfs_file_compat_ioctl,
|
|
#endif
|
|
.mmap = xfs_file_mmap,
|
|
.open = xfs_file_open,
|
|
.release = xfs_file_release,
|
|
.fsync = xfs_file_fsync,
|
|
.fallocate = xfs_file_fallocate,
|
|
};
|
|
|
|
const struct file_operations xfs_dir_file_operations = {
|
|
.open = xfs_dir_open,
|
|
.read = generic_read_dir,
|
|
.iterate = xfs_file_readdir,
|
|
.llseek = generic_file_llseek,
|
|
.unlocked_ioctl = xfs_file_ioctl,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = xfs_file_compat_ioctl,
|
|
#endif
|
|
.fsync = xfs_dir_fsync,
|
|
};
|