From bcc561f21f115437a010307420fc43d91be91c66 Mon Sep 17 00:00:00 2001 From: Chandan Babu R Date: Fri, 22 Jan 2021 16:48:15 -0800 Subject: 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: Darrick J. Wong Reviewed-by: Allison Henderson Signed-off-by: Chandan Babu R Signed-off-by: Darrick J. Wong --- 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); -- cgit v1.2.3