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| author | Christoph Hellwig <hch@lst.de> | 2023-10-16 17:28:52 +0200 |
|---|---|---|
| committer | Chandan Babu R <chandanbabu@kernel.org> | 2023-11-13 09:09:19 +0530 |
| commit | 55f669f34184ecb25b8353f29c7f6f1ae5b313d1 (patch) | |
| tree | 42ffb5cf13f1efa650d67815efd1aa0fede59a39 /fs | |
| parent | 00080503612f61d1ad67be641ed9cb4f9f6ba40e (diff) | |
| download | linux-55f669f34184ecb25b8353f29c7f6f1ae5b313d1.tar.gz | |
xfs: only remap the written blocks in xfs_reflink_end_cow_extent
xfs_reflink_end_cow_extent looks up the COW extent and the data fork
extent at offset_fsb, and then proceeds to remap the common subset
between the two.
It does however not limit the remapped extent to the passed in
[*offset_fsbm end_fsb] range and thus potentially remaps more blocks than
the one handled by the current I/O completion. This means that with
sufficiently large data and COW extents we could be remapping COW fork
mappings that have not been written to, leading to a stale data exposure
on a powerfail event.
We use to have a xfs_trim_range to make the remap fit the I/O completion
range, but that got (apparently accidentally) removed in commit
df2fd88f8ac7 ("xfs: rewrite xfs_reflink_end_cow to use intents").
Note that I've only found this by code inspection, and a test case would
probably require very specific delay and error injection.
Fixes: df2fd88f8ac7 ("xfs: rewrite xfs_reflink_end_cow to use intents")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/xfs/xfs_reflink.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 658edee8381dcd..e5b62dc2846644 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -784,6 +784,7 @@ xfs_reflink_end_cow_extent( } } del = got; + xfs_trim_extent(&del, *offset_fsb, end_fsb - *offset_fsb); /* Grab the corresponding mapping in the data fork. */ nmaps = 1; |