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authorChristoph Hellwig <hch@lst.de>2023-10-16 17:28:52 +0200
committerChandan Babu R <chandanbabu@kernel.org>2023-11-13 04:39:19 +0100
commit55f669f34184ecb25b8353f29c7f6f1ae5b313d1 (patch)
tree42ffb5cf13f1efa650d67815efd1aa0fede59a39
parentXFS: Update MAINTAINERS to catch all XFS documentation (diff)
downloadlinux-55f669f34184ecb25b8353f29c7f6f1ae5b313d1.tar.xz
linux-55f669f34184ecb25b8353f29c7f6f1ae5b313d1.zip
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>
-rw-r--r--fs/xfs/xfs_reflink.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 658edee8381d..e5b62dc28466 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;