xfs: refactor btree node scrubbing

Break up xchk_da_btree_entry and handle looking up leaf node entries
in the attr / dir callbacks, so that only the generic node handling
is left in the common core code.  Note that the checks for the crc
enabled blocks are removed, as the scrubbing code already remaps the
magic numbers earlier.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

fs/xfs/scrub/attr.c

@@ -398,15 +398,14 @@ xchk_xattr_block(
 STATIC int
 xchk_xattr_rec(
 	struct xchk_da_btree		*ds,
-	int				level,
-	void				*rec)
+	int				level)
 {
 	struct xfs_mount		*mp = ds->state->mp;
-	struct xfs_attr_leaf_entry	*ent = rec;
-	struct xfs_da_state_blk		*blk;
+	struct xfs_da_state_blk		*blk = &ds->state->path.blk[level];
 	struct xfs_attr_leaf_name_local	*lentry;
 	struct xfs_attr_leaf_name_remote	*rentry;
 	struct xfs_buf			*bp;
+	struct xfs_attr_leaf_entry	*ent;
 	xfs_dahash_t			calc_hash;
 	xfs_dahash_t			hash;
 	int				nameidx;
@@ -414,7 +413,9 @@ xchk_xattr_rec(
 	unsigned int			badflags;
 	int				error;
 
-	blk = &ds->state->path.blk[level];
+	ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
+
+	ent = xfs_attr3_leaf_entryp(blk->bp->b_addr) + blk->index;
 
 	/* Check the whole block, if necessary. */
 	error = xchk_xattr_block(ds, level);

fs/xfs/scrub/dabtree.c

@@ -77,40 +77,17 @@ xchk_da_set_corrupt(
 			__return_address);
 }
 
-/* Find an entry at a certain level in a da btree. */
-STATIC void *
-xchk_da_btree_entry(
-	struct xchk_da_btree	*ds,
-	int			level,
-	int			rec)
+static struct xfs_da_node_entry *
+xchk_da_btree_node_entry(
+	struct xchk_da_btree		*ds,
+	int				level)
 {
-	char			*ents;
-	struct xfs_da_state_blk	*blk;
-	void			*baddr;
+	struct xfs_da_state_blk		*blk = &ds->state->path.blk[level];
 
-	/* Dispatch the entry finding function. */
-	blk = &ds->state->path.blk[level];
-	baddr = blk->bp->b_addr;
-	switch (blk->magic) {
-	case XFS_ATTR_LEAF_MAGIC:
-	case XFS_ATTR3_LEAF_MAGIC:
-		ents = (char *)xfs_attr3_leaf_entryp(baddr);
-		return ents + (rec * sizeof(struct xfs_attr_leaf_entry));
-	case XFS_DIR2_LEAFN_MAGIC:
-	case XFS_DIR3_LEAFN_MAGIC:
-		ents = (char *)ds->dargs.dp->d_ops->leaf_ents_p(baddr);
-		return ents + (rec * sizeof(struct xfs_dir2_leaf_entry));
-	case XFS_DIR2_LEAF1_MAGIC:
-	case XFS_DIR3_LEAF1_MAGIC:
-		ents = (char *)ds->dargs.dp->d_ops->leaf_ents_p(baddr);
-		return ents + (rec * sizeof(struct xfs_dir2_leaf_entry));
-	case XFS_DA_NODE_MAGIC:
-	case XFS_DA3_NODE_MAGIC:
-		ents = (char *)ds->dargs.dp->d_ops->node_tree_p(baddr);
-		return ents + (rec * sizeof(struct xfs_da_node_entry));
-	}
+	ASSERT(blk->magic == XFS_DA_NODE_MAGIC);
 
-	return NULL;
+	return (void *)ds->dargs.dp->d_ops->node_tree_p(blk->bp->b_addr) +
+		(blk->index * sizeof(struct xfs_da_node_entry));
 }
 
 /* Scrub a da btree hash (key). */
@@ -120,7 +97,6 @@ xchk_da_btree_hash(
 	int				level,
 	__be32				*hashp)
 {
-	struct xfs_da_state_blk		*blks;
 	struct xfs_da_node_entry	*entry;
 	xfs_dahash_t			hash;
 	xfs_dahash_t			parent_hash;
@@ -135,8 +111,7 @@ xchk_da_btree_hash(
 		return 0;
 
 	/* Is this hash no larger than the parent hash? */
-	blks = ds->state->path.blk;
-	entry = xchk_da_btree_entry(ds, level - 1, blks[level - 1].index);
+	entry = xchk_da_btree_node_entry(ds, level - 1);
 	parent_hash = be32_to_cpu(entry->hashval);
 	if (parent_hash < hash)
 		xchk_da_set_corrupt(ds, level);
@@ -479,7 +454,6 @@ xchk_da_btree(
 	struct xfs_mount		*mp = sc->mp;
 	struct xfs_da_state_blk		*blks;
 	struct xfs_da_node_entry	*key;
-	void				*rec;
 	xfs_dablk_t			blkno;
 	int				level;
 	int				error;
@@ -537,9 +511,7 @@ xchk_da_btree(
 			}
 
 			/* Dispatch record scrubbing. */
-			rec = xchk_da_btree_entry(&ds, level,
-					blks[level].index);
-			error = scrub_fn(&ds, level, rec);
+			error = scrub_fn(&ds, level);
 			if (error)
 				break;
 			if (xchk_should_terminate(sc, &error) ||
@@ -561,7 +533,7 @@ xchk_da_btree(
 		}
 
 		/* Hashes in order for scrub? */
-		key = xchk_da_btree_entry(&ds, level, blks[level].index);
+		key = xchk_da_btree_node_entry(&ds, level);
 		error = xchk_da_btree_hash(&ds, level, &key->hashval);
 		if (error)
 			goto out;

fs/xfs/scrub/dabtree.h

@@ -28,8 +28,7 @@ struct xchk_da_btree {
 	int			tree_level;
 };
 
-typedef int (*xchk_da_btree_rec_fn)(struct xchk_da_btree *ds,
-		int level, void *rec);
+typedef int (*xchk_da_btree_rec_fn)(struct xchk_da_btree *ds, int level);
 
 /* Check for da btree operation errors. */
 bool xchk_da_process_error(struct xchk_da_btree *ds, int level, int *error);

fs/xfs/scrub/dir.c

@@ -182,14 +182,14 @@ xchk_dir_actor(
 STATIC int
 xchk_dir_rec(
 	struct xchk_da_btree		*ds,
-	int				level,
-	void				*rec)
+	int				level)
 {
+	struct xfs_da_state_blk		*blk = &ds->state->path.blk[level];
 	struct xfs_mount		*mp = ds->state->mp;
-	struct xfs_dir2_leaf_entry	*ent = rec;
 	struct xfs_inode		*dp = ds->dargs.dp;
 	struct xfs_dir2_data_entry	*dent;
 	struct xfs_buf			*bp;
+	struct xfs_dir2_leaf_entry	*ent;
 	char				*p, *endp;
 	xfs_ino_t			ino;
 	xfs_dablk_t			rec_bno;
@@ -201,6 +201,12 @@ xchk_dir_rec(
 	unsigned int			tag;
 	int				error;
 
+	ASSERT(blk->magic == XFS_DIR2_LEAF1_MAGIC ||
+	       blk->magic == XFS_DIR2_LEAFN_MAGIC);
+
+	ent = (void *)ds->dargs.dp->d_ops->leaf_ents_p(blk->bp->b_addr) +
+		(blk->index * sizeof(struct xfs_dir2_leaf_entry));
+
 	/* Check the hash of the entry. */
 	error = xchk_da_btree_hash(ds, level, &ent->hashval);
 	if (error)