lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Btrfs: fix a bug in checking whether a inode is already in log

Browse Source 
This is based on Josef's "Btrfs: turbo charge fsync".

The current btrfs checks if an inode is in log by comparing
root's last_log_commit to inode's last_sub_trans[2].

But the problem is that this root->last_log_commit is shared among
inodes.

Say we have N inodes to be logged, after the first inode,
root's last_log_commit is updated and the N-1 remained files will
be skipped.

This fixes the bug by keeping a local copy of root's last_log_commit
inside each inode and this local copy will be maintained itself.

[1]: we regard each log transaction as a subset of btrfs's transaction,
i.e. sub_trans

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
This commit is contained in:
Liu Bo
2012-08-29 01:07:55 -06:00
committed by Chris Mason
parent 321f0e7022
commit 46d8bc3424
4 changed files with 10 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
fs/btrfs/inode.c
View File

@@ -6774,6 +6774,7 @@ again:
BTRFS_I(inode)->last_trans = root->fs_info->generation;
BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
@@ -7018,6 +7019,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
ei->csum_bytes = 0;
ei->index_cnt = (u64)-1;
ei->last_unlink_trans = 0;
ei->last_log_commit = 0;
spin_lock_init(&ei->lock);
ei->outstanding_extents = 0;