bcachefs: bch2_inode_find_snapshot_root()

Factor out a small common helper.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

4 files changed, 34 insertions, 51 deletions

diff --git a/fs/bcachefs/fsck.c b/fs/bcachefs/fsck.c
index 4258c91e6df3..e7cac5a69154 100644
--- a/fs/bcachefs/fsck.c
+++ b/fs/bcachefs/fsck.c
@@ -1115,32 +1115,6 @@ fsck_err:
 	return ret;
 }
 
-static int get_snapshot_root_inode(struct btree_trans *trans,
-				   struct bch_inode_unpacked *root,
-				   u64 inum)
-{
-	struct btree_iter iter;
-	struct bkey_s_c k;
-	int ret = 0;
-
-	for_each_btree_key_reverse_norestart(trans, iter, BTREE_ID_inodes,
-					     SPOS(0, inum, U32_MAX),
-					     BTREE_ITER_all_snapshots, k, ret) {
-		if (k.k->p.offset != inum)
-			break;
-		if (bkey_is_inode(k.k))
-			goto found_root;
-	}
-	if (ret)
-		goto err;
-	BUG();
-found_root:
-	ret = bch2_inode_unpack(k, root);
-err:
-	bch2_trans_iter_exit(trans, &iter);
-	return ret;
-}
-
 static int check_inode(struct btree_trans *trans,
 		       struct btree_iter *iter,
 		       struct bkey_s_c k,
@@ -1171,7 +1145,7 @@ static int check_inode(struct btree_trans *trans,
 		goto err;
 
 	if (snapshot_root->bi_inum != u.bi_inum) {
-		ret = get_snapshot_root_inode(trans, snapshot_root, u.bi_inum);
+		ret = bch2_inode_find_snapshot_root(trans, u.bi_inum, snapshot_root);
 		if (ret)
 			goto err;
 	}
diff --git a/fs/bcachefs/inode.c b/fs/bcachefs/inode.c
index 96d4ab0148bf..a17a952ea161 100644
--- a/fs/bcachefs/inode.c
+++ b/fs/bcachefs/inode.c
@@ -1131,6 +1131,30 @@ int bch2_inode_find_by_inum(struct bch_fs *c, subvol_inum inum,
 	return bch2_trans_do(c, bch2_inode_find_by_inum_trans(trans, inum, inode));
 }
 
+int bch2_inode_find_snapshot_root(struct btree_trans *trans, u64 inum,
+				  struct bch_inode_unpacked *root)
+{
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	int ret = 0;
+
+	for_each_btree_key_reverse_norestart(trans, iter, BTREE_ID_inodes,
+					     SPOS(0, inum, U32_MAX),
+					     BTREE_ITER_all_snapshots, k, ret) {
+		if (k.k->p.offset != inum)
+			break;
+		if (bkey_is_inode(k.k)) {
+			ret = bch2_inode_unpack(k, root);
+			goto out;
+		}
+	}
+	/* We're only called when we know we have an inode for @inum */
+	BUG_ON(!ret);
+out:
+	bch2_trans_iter_exit(trans, &iter);
+	return ret;
+}
+
 int bch2_inode_nlink_inc(struct bch_inode_unpacked *bi)
 {
 	if (bi->bi_flags & BCH_INODE_unlinked)
diff --git a/fs/bcachefs/inode.h b/fs/bcachefs/inode.h
index 5cfba9e98966..bb81b7c269bb 100644
--- a/fs/bcachefs/inode.h
+++ b/fs/bcachefs/inode.h
@@ -173,6 +173,9 @@ int bch2_inode_find_by_inum_trans(struct btree_trans *, subvol_inum,
 int bch2_inode_find_by_inum(struct bch_fs *, subvol_inum,
 			    struct bch_inode_unpacked *);
 
+int bch2_inode_find_snapshot_root(struct btree_trans *trans, u64 inum,
+				  struct bch_inode_unpacked *root);
+
 #define inode_opt_get(_c, _inode, _name)			\
 	((_inode)->bi_##_name ? (_inode)->bi_##_name - 1 : (_c)->opts._name)
 
diff --git a/fs/bcachefs/str_hash.c b/fs/bcachefs/str_hash.c
index 55a3a116b5a8..2d6379473ad4 100644
--- a/fs/bcachefs/str_hash.c
+++ b/fs/bcachefs/str_hash.c
@@ -146,34 +146,17 @@ static noinline int check_inode_hash_info_matches_root(struct btree_trans *trans
 						       struct bch_hash_info *hash_info)
 {
 	struct bch_fs *c = trans->c;
-	struct btree_iter iter;
-	struct bkey_s_c k;
-	int ret = 0;
-
-	for_each_btree_key_reverse_norestart(trans, iter, BTREE_ID_inodes, SPOS(0, inum, U32_MAX),
-					     BTREE_ITER_all_snapshots, k, ret) {
-		if (k.k->p.offset != inum)
-			break;
-		if (bkey_is_inode(k.k))
-			goto found;
-	}
-
-	/* This would've been caught by check_key_has_inode() */
-	bch_err(c, "%s(): inum %llu not found", __func__, inum);
-	ret = -BCH_ERR_fsck_repair_unimplemented;
-	goto err;
-found:;
-	struct bch_inode_unpacked inode;
-	ret = bch2_inode_unpack(k, &inode);
+	struct bch_inode_unpacked snapshot_root;
+	int ret = bch2_inode_find_snapshot_root(trans, inum, &snapshot_root);
 	if (ret)
-		goto err;
+		return ret;
 
-	struct bch_hash_info hash_root = bch2_hash_info_init(c, &inode);
+	struct bch_hash_info hash_root = bch2_hash_info_init(c, &snapshot_root);
 	if (hash_info->type != hash_root.type ||
 	    memcmp(&hash_info->siphash_key,
 		   &hash_root.siphash_key,
 		   sizeof(hash_root.siphash_key))) {
-		ret = repair_inode_hash_info(trans, &inode);
+		ret = repair_inode_hash_info(trans, &snapshot_root);
 		if (!ret) {
 			struct printbuf buf = PRINTBUF;
 			prt_printf(&buf, "inode %llu hash info mismatch with root, but mismatch not found\n", inum);
@@ -190,8 +173,7 @@ found:;
 			ret = -BCH_ERR_fsck_repair_unimplemented;
 		}
 	}
-err:
-	bch2_trans_iter_exit(trans, &iter);
+
 	return ret;
 }