xfs: repair inode btrees

Use the rmapbt to find inode chunks, query the chunks to compute hole
and free masks, and with that information rebuild the inobt and finobt.
Refer to the case study in
Documentation/filesystems/xfs-online-fsck-design.rst for more details.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 18 insertions, 13 deletions

diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c
index d61d03e5b853..2361a22035b0 100644
--- a/fs/xfs/libxfs/xfs_ialloc.c
+++ b/fs/xfs/libxfs/xfs_ialloc.c
@@ -95,18 +95,28 @@ xfs_inobt_btrec_to_irec(
 	irec->ir_free = be64_to_cpu(rec->inobt.ir_free);
 }
 
+/* Compute the freecount of an incore inode record. */
+uint8_t
+xfs_inobt_rec_freecount(
+	const struct xfs_inobt_rec_incore	*irec)
+{
+	uint64_t				realfree = irec->ir_free;
+
+	if (xfs_inobt_issparse(irec->ir_holemask))
+		realfree &= xfs_inobt_irec_to_allocmask(irec);
+	return hweight64(realfree);
+}
+
 /* Simple checks for inode records. */
 xfs_failaddr_t
 xfs_inobt_check_irec(
-	struct xfs_btree_cur			*cur,
+	struct xfs_perag			*pag,
 	const struct xfs_inobt_rec_incore	*irec)
 {
-	uint64_t			realfree;
-
 	/* Record has to be properly aligned within the AG. */
-	if (!xfs_verify_agino(cur->bc_ag.pag, irec->ir_startino))
+	if (!xfs_verify_agino(pag, irec->ir_startino))
 		return __this_address;
-	if (!xfs_verify_agino(cur->bc_ag.pag,
+	if (!xfs_verify_agino(pag,
 				irec->ir_startino + XFS_INODES_PER_CHUNK - 1))
 		return __this_address;
 	if (irec->ir_count < XFS_INODES_PER_HOLEMASK_BIT ||
@@ -115,12 +125,7 @@ xfs_inobt_check_irec(
 	if (irec->ir_freecount > XFS_INODES_PER_CHUNK)
 		return __this_address;
 
-	/* if there are no holes, return the first available offset */
-	if (!xfs_inobt_issparse(irec->ir_holemask))
-		realfree = irec->ir_free;
-	else
-		realfree = irec->ir_free & xfs_inobt_irec_to_allocmask(irec);
-	if (hweight64(realfree) != irec->ir_freecount)
+	if (xfs_inobt_rec_freecount(irec) != irec->ir_freecount)
 		return __this_address;
 
 	return NULL;
@@ -164,7 +169,7 @@ xfs_inobt_get_rec(
 		return error;
 
 	xfs_inobt_btrec_to_irec(mp, rec, irec);
-	fa = xfs_inobt_check_irec(cur, irec);
+	fa = xfs_inobt_check_irec(cur->bc_ag.pag, irec);
 	if (fa)
 		return xfs_inobt_complain_bad_rec(cur, fa, irec);
 
@@ -2740,7 +2745,7 @@ xfs_ialloc_count_inodes_rec(
 	xfs_failaddr_t			fa;
 
 	xfs_inobt_btrec_to_irec(cur->bc_mp, rec, &irec);
-	fa = xfs_inobt_check_irec(cur, &irec);
+	fa = xfs_inobt_check_irec(cur->bc_ag.pag, &irec);
 	if (fa)
 		return xfs_inobt_complain_bad_rec(cur, fa, &irec);