xfs: refactor file range validation

Refactor all the open-coded validation of file block ranges into a
single helper, and teach the bmap scrubber to check the ranges.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 25 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_types.c b/fs/xfs/libxfs/xfs_types.c
index 7b310eb296b7..b254fbeaaa50 100644
--- a/fs/xfs/libxfs/xfs_types.c
+++ b/fs/xfs/libxfs/xfs_types.c
@@ -258,3 +258,28 @@ xfs_verify_dablk(
 
 	return dabno <= max_dablk;
 }
+
+/* Check that a file block offset does not exceed the maximum. */
+bool
+xfs_verify_fileoff(
+	struct xfs_mount	*mp,
+	xfs_fileoff_t		off)
+{
+	return off <= XFS_MAX_FILEOFF;
+}
+
+/* Check that a range of file block offsets do not exceed the maximum. */
+bool
+xfs_verify_fileext(
+	struct xfs_mount	*mp,
+	xfs_fileoff_t		off,
+	xfs_fileoff_t		len)
+{
+	if (off + len <= off)
+		return false;
+
+	if (!xfs_verify_fileoff(mp, off))
+		return false;
+
+	return xfs_verify_fileoff(mp, off + len - 1);
+}