diff options
author | Chandan Babu R <chandanrlinux@gmail.com> | 2021-01-22 16:48:14 -0800 |
---|---|---|
committer | Darrick J. Wong <djwong@kernel.org> | 2021-01-22 16:54:48 -0800 |
commit | 5f1d5bbfb2e674052a9fe542f53678978af20770 (patch) | |
tree | 3dd04de39ef9bed596a3a78bd4c098692b1476a6 | |
parent | c442f3086d5a108b7ff086c8ade1923a8f389db5 (diff) | |
download | linux-5f1d5bbfb2e674052a9fe542f53678978af20770.tar.bz2 |
xfs: Check for extent overflow when moving extent from cow to data fork
Moving an extent to data fork can cause a sub-interval of an existing
extent to be unmapped. This will increase extent count by 1. Mapping in
the new extent can increase the extent count by 1 again i.e.
| Old extent | New extent | Old extent |
Hence number of extents increases by 2.
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
-rw-r--r-- | fs/xfs/libxfs/xfs_inode_fork.h | 9 | ||||
-rw-r--r-- | fs/xfs/xfs_reflink.c | 5 |
2 files changed, 14 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h index 917e289ad962..c8f279edc5c1 100644 --- a/fs/xfs/libxfs/xfs_inode_fork.h +++ b/fs/xfs/libxfs/xfs_inode_fork.h @@ -80,6 +80,15 @@ struct xfs_ifork { /* + * Moving an extent to data fork can cause a sub-interval of an existing extent + * to be unmapped. This will increase extent count by 1. Mapping in the new + * extent can increase the extent count by 1 again i.e. + * | Old extent | New extent | Old extent | + * Hence number of extents increases by 2. + */ +#define XFS_IEXT_REFLINK_END_COW_CNT (2) + +/* * Fork handling. */ diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 6fa05fb78189..ca0ac1426d74 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -628,6 +628,11 @@ xfs_reflink_end_cow_extent( xfs_ilock(ip, XFS_ILOCK_EXCL); xfs_trans_ijoin(tp, ip, 0); + error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK, + XFS_IEXT_REFLINK_END_COW_CNT); + if (error) + goto out_cancel; + /* * In case of racing, overlapping AIO writes no COW extents might be * left by the time I/O completes for the loser of the race. In that |