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| author | Liu Bo <bo.li.liu@oracle.com> | 2018-01-31 17:09:13 -0700 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2018-03-26 15:09:39 +0200 |
| commit | 5811375325420052fcadd944792a416a43072b7f (patch) | |
| tree | 67017d6e8f050378c5de9612d51c6ffe65d74d1a /fs | |
| parent | 9678c54388b6a6b309ff7ee5c8d23fa9eba7c06f (diff) | |
| download | lwn-5811375325420052fcadd944792a416a43072b7f.tar.gz lwn-5811375325420052fcadd944792a416a43072b7f.zip | |
Btrfs: fix unexpected cow in run_delalloc_nocow
Fstests generic/475 provides a way to fail metadata reads while
checking if checksum exists for the inode inside run_delalloc_nocow(),
and csum_exist_in_range() interprets error (-EIO) as inode having
checksum and makes its caller enter the cow path.
In case of free space inode, this ends up with a warning in
cow_file_range().
The same problem applies to btrfs_cross_ref_exist() since it may also
read metadata in between.
With this, run_delalloc_nocow() bails out when errors occur at the two
places.
cc: <stable@vger.kernel.org> v2.6.28+
Fixes: 17d217fe970d ("Btrfs: fix nodatasum handling in balancing code")
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/inode.c | 37 |
1 files changed, 32 insertions, 5 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 6504e63b2317..491a7397f6fa 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1256,6 +1256,8 @@ static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info, list_del(&sums->list); kfree(sums); } + if (ret < 0) + return ret; return 1; } @@ -1388,10 +1390,23 @@ next_slot: goto out_check; if (btrfs_extent_readonly(fs_info, disk_bytenr)) goto out_check; - if (btrfs_cross_ref_exist(root, ino, - found_key.offset - - extent_offset, disk_bytenr)) + ret = btrfs_cross_ref_exist(root, ino, + found_key.offset - + extent_offset, disk_bytenr); + if (ret) { + /* + * ret could be -EIO if the above fails to read + * metadata. + */ + if (ret < 0) { + if (cow_start != (u64)-1) + cur_offset = cow_start; + goto error; + } + + WARN_ON_ONCE(nolock); goto out_check; + } disk_bytenr += extent_offset; disk_bytenr += cur_offset - found_key.offset; num_bytes = min(end + 1, extent_end) - cur_offset; @@ -1409,10 +1424,22 @@ next_slot: * this ensure that csum for a given extent are * either valid or do not exist. */ - if (csum_exist_in_range(fs_info, disk_bytenr, - num_bytes)) { + ret = csum_exist_in_range(fs_info, disk_bytenr, + num_bytes); + if (ret) { if (!nolock) btrfs_end_write_no_snapshotting(root); + + /* + * ret could be -EIO if the above fails to read + * metadata. + */ + if (ret < 0) { + if (cow_start != (u64)-1) + cur_offset = cow_start; + goto error; + } + WARN_ON_ONCE(nolock); goto out_check; } if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr)) { |