xfs: fix partially uninitialized structure in xfs_reflink_remap_extent

BugLink: https://bugs.launchpad.net/bugs/1876765
[ Upstream commit c142932c29e533ee892f87b44d8abc5719edceec ]

In the reflink extent remap function, it turns out that uirec (the block
mapping corresponding only to the part of the passed-in mapping that got
unmapped) was not fully initialized.  Specifically, br_state was not
being copied from the passed-in struct to the uirec.  This could lead to
unpredictable results such as the reflinked mapping being marked
unwritten in the destination file.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 0f08153b4994190fcd21d8b4fd9f6914ae908cb4..6a4fd1738b08692b4c45015c0b60382b7c3f2f8f 100644 (file)
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1053,6 +1053,7 @@ xfs_reflink_remap_extent(
                uirec.br_startblock = irec->br_startblock + rlen;
                uirec.br_startoff = irec->br_startoff + rlen;
                uirec.br_blockcount = unmap_len - rlen;
+               uirec.br_state = irec->br_state;
                unmap_len = rlen;
 
                /* If this isn't a real mapping, we're done. */