Commit bcc561f2 authored by Chandan Babu R's avatar Chandan Babu R Committed by Darrick J. Wong
Browse files

xfs: Check for extent overflow when swapping extents 



Removing an initial range of source/donor file's extent and adding a new
extent (from donor/source file) in its place will cause extent count to
increase by 1.

Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarAllison Henderson <allison.henderson@oracle.com>
Signed-off-by: default avatarChandan Babu R <chandanrlinux@gmail.com>
Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
parent ee898d78

fs/xfs/libxfs/xfs_inode_fork.h

+7 −0
Original line number Diff line number Diff line
@@ -88,6 +88,13 @@ struct xfs_ifork { 
 */

#define XFS_IEXT_REFLINK_END_COW_CNT	(2)



/*

 * Removing an initial range of source/donor file's extent and adding a new

 * extent (from donor/source file) in its place will cause extent count to

 * increase by 1.

 */

#define XFS_IEXT_SWAP_RMAP_CNT		(1)



/*

 * Fork handling.

 */

fs/xfs/xfs_bmap_util.c

+16 −0
Original line number Diff line number Diff line
@@ -1399,6 +1399,22 @@ xfs_swap_extent_rmap( 
					irec.br_blockcount);

			trace_xfs_swap_extent_rmap_remap_piece(tip, &uirec);



			if (xfs_bmap_is_real_extent(&uirec)) {

				error = xfs_iext_count_may_overflow(ip,

						XFS_DATA_FORK,

						XFS_IEXT_SWAP_RMAP_CNT);

				if (error)

					goto out;

			}



			if (xfs_bmap_is_real_extent(&irec)) {

				error = xfs_iext_count_may_overflow(tip,

						XFS_DATA_FORK,

						XFS_IEXT_SWAP_RMAP_CNT);

				if (error)

					goto out;

			}



			/* Remove the mapping from the donor file. */

			xfs_bmap_unmap_extent(tp, tip, &uirec);