forked from Minki/linux
3edf7d33f4
Data checksumming is done right before the bio is sent down the IO stack, which means a single bio might span more than one ordered extent. In this case, the checksumming data is split between two ordered extents. Signed-off-by: Chris Mason <chris.mason@oracle.com>
136 lines
4.0 KiB
C
136 lines
4.0 KiB
C
/*
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* Copyright (C) 2007 Oracle. 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
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will 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 GNU
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* 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
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#ifndef __BTRFS_ORDERED_DATA__
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#define __BTRFS_ORDERED_DATA__
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/* one of these per inode */
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struct btrfs_ordered_inode_tree {
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struct mutex mutex;
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struct rb_root tree;
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struct rb_node *last;
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};
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/*
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* these are used to collect checksums done just before bios submission.
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* They are attached via a list into the ordered extent, and
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* checksum items are inserted into the tree after all the blocks in
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* the ordered extent are on disk
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*/
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struct btrfs_sector_sum {
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u64 offset;
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u32 sum;
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};
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struct btrfs_ordered_sum {
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u64 file_offset;
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/*
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* this is the length in bytes covered by the sums array below.
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* But, the sums array may not be contiguous in the file.
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*/
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unsigned long len;
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struct list_head list;
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/* last field is a variable length array of btrfs_sector_sums */
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struct btrfs_sector_sum sums;
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};
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/*
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* bits for the flags field:
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*
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* BTRFS_ORDERED_IO_DONE is set when all of the blocks are written.
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* It is used to make sure metadata is inserted into the tree only once
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* per extent.
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*
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* BTRFS_ORDERED_COMPLETE is set when the extent is removed from the
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* rbtree, just before waking any waiters. It is used to indicate the
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* IO is done and any metadata is inserted into the tree.
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*/
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#define BTRFS_ORDERED_IO_DONE 0 /* set when all the pages are written */
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#define BTRFS_ORDERED_COMPLETE 1 /* set when removed from the tree */
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struct btrfs_ordered_extent {
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/* logical offset in the file */
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u64 file_offset;
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/* disk byte number */
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u64 start;
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/* length of the extent in bytes */
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u64 len;
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/* flags (described above) */
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unsigned long flags;
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/* reference count */
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atomic_t refs;
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/* list of checksums for insertion when the extent io is done */
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struct list_head list;
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/* used to wait for the BTRFS_ORDERED_COMPLETE bit */
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wait_queue_head_t wait;
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/* our friendly rbtree entry */
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struct rb_node rb_node;
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};
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/*
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* calculates the total size you need to allocate for an ordered sum
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* structure spanning 'bytes' in the file
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*/
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static inline int btrfs_ordered_sum_size(struct btrfs_root *root, u64 bytes)
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{
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unsigned long num_sectors = (bytes + root->sectorsize - 1) /
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root->sectorsize;
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num_sectors++;
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return sizeof(struct btrfs_ordered_sum) +
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num_sectors * sizeof(struct btrfs_sector_sum);
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}
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static inline void
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btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
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{
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mutex_init(&t->mutex);
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t->tree.rb_node = NULL;
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t->last = NULL;
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}
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int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
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int btrfs_remove_ordered_extent(struct inode *inode,
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struct btrfs_ordered_extent *entry);
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int btrfs_dec_test_ordered_pending(struct inode *inode,
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u64 file_offset, u64 io_size);
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int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
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u64 start, u64 len);
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int btrfs_add_ordered_sum(struct inode *inode,
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struct btrfs_ordered_extent *entry,
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struct btrfs_ordered_sum *sum);
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struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
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u64 file_offset);
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void btrfs_start_ordered_extent(struct inode *inode,
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struct btrfs_ordered_extent *entry, int wait);
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void btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
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struct btrfs_ordered_extent *
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btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
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int btrfs_ordered_update_i_size(struct inode *inode,
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struct btrfs_ordered_extent *ordered);
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int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u32 *sum);
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#endif
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