[7/9] xfs: scrub big block inode btrees correctly

Commit Message

Darrick J. Wong Nov. 15, 2018, 6:05 a.m. UTC

From: Darrick J. Wong <[e-mail]>

Teach scrub how to handle the case that there are one or more inobt
records covering a given inode cluster.  This fixes the operation on big
block filesystems (e.g. 64k blocks, 512 byte inodes).

Signed-off-by: Darrick J. Wong <[e-mail]>
---
 fs/xfs/scrub/ialloc.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

Patch

diff --git a/fs/xfs/scrub/ialloc.c b/fs/xfs/scrub/ialloc.c
index 1d79f12dfce5..26bcf359b326 100644
--- a/fs/xfs/scrub/ialloc.c
+++ b/fs/xfs/scrub/ialloc.c
@@ -162,6 +162,7 @@  xchk_iallocbt_check_cluster_ifree(
 	xfs_ino_t			fsino;
 	xfs_agino_t			agino;
 	unsigned int			offset;
+	unsigned int			cluster_buf_base;
 	bool				irec_free;
 	bool				ino_inuse;
 	bool				freemask_ok;
@@ -174,11 +175,14 @@  xchk_iallocbt_check_cluster_ifree(
 	 * Given an inobt record, an offset of a cluster within the record,
 	 * and an offset of an inode within a cluster, compute which fs inode
 	 * we're talking about and the offset of the inode record within the
-	 * inode buffer.
+	 * inode buffer, being careful about inobt records that don't align
+	 * with the start of the inode buffer when block sizes are large.
 	 */
 	agino = irec->ir_startino + cluster_base + cluster_index;
 	fsino = XFS_AGINO_TO_INO(mp, bs->cur->bc_private.a.agno, agino);
-	offset = cluster_index * mp->m_sb.sb_inodesize;
+	cluster_buf_base = XFS_INO_TO_OFFSET(mp, irec->ir_startino +
+					     cluster_base);
+	offset = (cluster_buf_base + cluster_index) * mp->m_sb.sb_inodesize;
 	if (offset >= BBTOB(cluster_bp->b_length)) {
 		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
 		goto out;