From: "Darrick J. Wong" djwong@kernel.org
commit de55149b6639e903c4d06eb0474ab2c05060e61d upstream.
While refactoring code, I noticed that when xfs_iroot_realloc tries to shrink a bmbt root block, it allocates a smaller new block and then copies "records" and pointers to the new block. However, bmbt root blocks cannot ever be leaves, which means that it's not technically correct to copy records. We /should/ be copying keys.
Note that this has never resulted in actual memory corruption because sizeof(bmbt_rec) == (sizeof(bmbt_key) + sizeof(bmbt_ptr)). However, this will no longer be true when we start adding realtime rmap stuff, so fix this now.
Signed-off-by: Darrick J. Wong djwong@kernel.org Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Catherine Hoang catherine.hoang@oracle.com Acked-by: Darrick J. Wong djwong@kernel.org --- fs/xfs/libxfs/xfs_inode_fork.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c index 5a2e7ddfa76d..25b86ffc2ce3 100644 --- a/fs/xfs/libxfs/xfs_inode_fork.c +++ b/fs/xfs/libxfs/xfs_inode_fork.c @@ -449,15 +449,15 @@ xfs_iroot_realloc( }
/* - * Only copy the records and pointers if there are any. + * Only copy the keys and pointers if there are any. */ if (new_max > 0) { /* - * First copy the records. + * First copy the keys. */ - op = (char *)XFS_BMBT_REC_ADDR(mp, ifp->if_broot, 1); - np = (char *)XFS_BMBT_REC_ADDR(mp, new_broot, 1); - memcpy(np, op, new_max * (uint)sizeof(xfs_bmbt_rec_t)); + op = (char *)XFS_BMBT_KEY_ADDR(mp, ifp->if_broot, 1); + np = (char *)XFS_BMBT_KEY_ADDR(mp, new_broot, 1); + memcpy(np, op, new_max * (uint)sizeof(xfs_bmbt_key_t));
/* * Then copy the pointers.