[PATCH 4/5] xfs_db: don't error out when blocksize > 64 * inodesize

["Darrick J. Wong" <darrick.wong@xxxxxxxxxx>]

When the block size is large enough that multiple inode chunks can fit
in a single block (e.g. 64k blocks, 512 byte inodes) we must calculate
the per-chunk block size and the buffer offset correctly so that check
actually examines the correct metadata.

Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
 db/check.c |   13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)


diff --git a/db/check.c b/db/check.c
index 838db53..4e2768e 100644
--- a/db/check.c
+++ b/db/check.c
@@ -4386,6 +4386,7 @@ scanfunc_ino(
        __u16                   holemask;
        xfs_agino_t             rino;
        xfs_extlen_t            cblocks;
+       int                     bufoff;
 
        if (be32_to_cpu(block->bb_magic) != XFS_IBT_MAGIC &&
            be32_to_cpu(block->bb_magic) != XFS_IBT_CRC_MAGIC) {
@@ -4455,6 +4456,8 @@ scanfunc_ino(
                                rino = agino + startidx;
                                cblocks = (endidx - startidx) >>
                                                mp->m_sb.sb_inopblog;
+                               if (cblocks == 0)
+                                       cblocks = 1;
 
                                /* Check the sparse chunk alignment */
                                if (sparse &&
@@ -4468,8 +4471,9 @@ scanfunc_ino(
                                }
 
                                /* Check the block map */
-                               set_dbmap(seqno, XFS_AGINO_TO_AGBNO(mp, rino),
-                                       cblocks, DBM_INODE, seqno, bno);
+                               if (XFS_AGINO_TO_OFFSET(mp, rino) == 0)
+                                       set_dbmap(seqno, XFS_AGINO_TO_AGBNO(mp, 
rino),
+                                               cblocks, DBM_INODE, seqno, bno);
 
                                push_cur();
                                set_cur(&typtab[TYP_INODE],
@@ -4489,14 +4493,15 @@ scanfunc_ino(
                                }
 
                                /* Examine each inode in this chunk */
-                               for (j = startidx; j < endidx; j++) {
+                               bufoff = ((XFS_AGINO_TO_OFFSET(mp, rino) - 
startidx) << mp->m_sb.sb_inodelog);
+                               for (j = startidx; j < endidx; j++, bufoff += 
(1 << mp->m_sb.sb_inodelog)) {
                                        if (ino_issparse(&rp[i], j))
                                                continue;
                                        isfree = XFS_INOBT_IS_FREE_DISK(&rp[i], 
j);
                                        if (isfree)
                                                nfree++;
                                        process_inode(agf, agino + j,
-                                               (xfs_dinode_t *)((char 
*)iocur_top->data + ((j - startidx) << mp->m_sb.sb_inodelog)),
+                                               (xfs_dinode_t *)((char 
*)iocur_top->data + bufoff),
                                                        isfree);
                                }
                                pop_cur();