[PATCH V14 11/16] xfs: Check for extent overflow when swapping extents
From: Chandan Babu R <hidden>
Date: 2021-01-10 16:11:14
Subsystem:
filesystems (vfs and infrastructure), the rest, xfs filesystem · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds, Carlos Maiolino
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: Darrick J. Wong <redacted> Reviewed-by: Allison Henderson <redacted> Signed-off-by: Chandan Babu R <redacted> --- fs/xfs/libxfs/xfs_inode_fork.h | 7 +++++++ fs/xfs/xfs_bmap_util.c | 16 ++++++++++++++++ 2 files changed, 23 insertions(+)
diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h
index c8f279edc5c1..9e2137cd7372 100644
--- a/fs/xfs/libxfs/xfs_inode_fork.h
+++ b/fs/xfs/libxfs/xfs_inode_fork.h@@ -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. */
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 6ac7a6ac2658..f3f8c48ff5bf 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c@@ -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);
--
2.29.2