Merge: xfs: fix sparse inode limits on runt AG

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/5846

JIRA: https://issues.redhat.com/browse/RHEL-68541

Upstream Status: https://git.kernel.org/pub/scm/fs/xfs/xfs-linux.git for-next

Conflicts: changed context due to unbackported upstream commit
    6abd82a xfs: add a xfs_agino_to_ino helper
    e9c4d8b xfs: factor out a generic xfs_group structure

    The runt AG at the end of a filesystem is almost always smaller than
    the mp->m_sb.sb_agblocks. Unfortunately, when setting the max_agbno
    limit for the inode chunk allocation, we do not take this into
    account. This means we can allocate a sparse inode chunk that
    overlaps beyond the end of an AG. When we go to allocate an inode
    from that sparse chunk, the irec fails validation because the
    agbno of the start of the irec is beyond valid limits for the runt
    AG.

    Prevent this from happening by taking into account the size of the
    runt AG when allocating inode chunks. Also convert the various
    checks for valid inode chunk agbnos to use xfs_ag_block_count()
    so that they will also catch such issues in the future.

    Fixes: 56d1115 ("xfs: allocate sparse inode chunks on full chunk allocation failure")
    Signed-off-by: Dave Chinner <dchinner@redhat.com>

Signed-off-by: Pavel Reichl <preichl@redhat.com>

Approved-by: Carlos Maiolino <cmaiolino@redhat.com>
Approved-by: Bill O'Donnell <bodonnel@redhat.com>
Approved-by: Ian Kent <ikent@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Rado Vrbovsky <rvrbovsk@redhat.com>

Author: emmil

fs/xfs/libxfs/xfs_ialloc.c

@@ -796,7 +796,8 @@ xfs_ialloc_ag_alloc(
 		 * the end of the AG.
 		 */
 		args.min_agbno = args.mp->m_sb.sb_inoalignmt;
-		args.max_agbno = round_down(args.mp->m_sb.sb_agblocks,
+		args.max_agbno = round_down(xfs_ag_block_count(args.mp,
+							pag->pag_agno),
 					    args.mp->m_sb.sb_inoalignmt) -
 				 igeo->ialloc_blks;
 
@@ -2190,9 +2191,9 @@ xfs_difree(
 		return -EINVAL;
 	}
 	agbno = XFS_AGINO_TO_AGBNO(mp, agino);
-	if (agbno >= mp->m_sb.sb_agblocks)  {
-		xfs_warn(mp, "%s: agbno >= mp->m_sb.sb_agblocks (%d >= %d).",
-			__func__, agbno, mp->m_sb.sb_agblocks);
+	if (agbno >= xfs_ag_block_count(mp, pag->pag_agno)) {
+		xfs_warn(mp, "%s: agbno >= xfs_ag_block_count (%d >= %d).",
+			__func__, agbno, xfs_ag_block_count(mp, pag->pag_agno));
 		ASSERT(0);
 		return -EINVAL;
 	}
@@ -2315,7 +2316,7 @@ xfs_imap(
 	 */
 	agino = XFS_INO_TO_AGINO(mp, ino);
 	agbno = XFS_AGINO_TO_AGBNO(mp, agino);
-	if (agbno >= mp->m_sb.sb_agblocks ||
+	if (agbno >= xfs_ag_block_count(mp, pag->pag_agno) ||
 	    ino != XFS_AGINO_TO_INO(mp, pag->pag_agno, agino)) {
 		error = -EINVAL;
 #ifdef DEBUG
@@ -2325,11 +2326,12 @@ xfs_imap(
 		 */
 		if (flags & XFS_IGET_UNTRUSTED)
 			return error;
-		if (agbno >= mp->m_sb.sb_agblocks) {
+		if (agbno >= xfs_ag_block_count(mp, pag->pag_agno)) {
 			xfs_alert(mp,
 		"%s: agbno (0x%llx) >= mp->m_sb.sb_agblocks (0x%lx)",
 				__func__, (unsigned long long)agbno,
-				(unsigned long)mp->m_sb.sb_agblocks);
+				(unsigned long)xfs_ag_block_count(mp,
+							pag->pag_agno));
 		}
 		if (ino != XFS_AGINO_TO_INO(mp, pag->pag_agno, agino)) {
 			xfs_alert(mp,