1 files changed, 137 insertions, 111 deletions

diff --git a/libbcachefs/fsck.c b/libbcachefs/fsck.c
index 7e82c7bc..e4a8a14c 100644
--- a/libbcachefs/fsck.c
+++ b/libbcachefs/fsck.c
@@ -5,7 +5,6 @@
 #include "btree_cache.h"
 #include "btree_update.h"
 #include "buckets.h"
-#include "darray.h"
 #include "dirent.h"
 #include "error.h"
 #include "fs-common.h"
@@ -18,6 +17,7 @@
 #include "xattr.h"
 
 #include <linux/bsearch.h>
+#include <linux/darray.h>
 #include <linux/dcache.h> /* struct qstr */
 
 /*
@@ -100,8 +100,8 @@ err:
 }
 
 static int lookup_inode(struct btree_trans *trans, u64 inode_nr,
-			  struct bch_inode_unpacked *inode,
-			  u32 *snapshot)
+			struct bch_inode_unpacked *inode,
+			u32 *snapshot)
 {
 	struct btree_iter iter;
 	struct bkey_s_c k;
@@ -123,17 +123,15 @@ err:
 	return ret;
 }
 
-static int __lookup_dirent(struct btree_trans *trans,
+static int lookup_dirent_in_snapshot(struct btree_trans *trans,
 			   struct bch_hash_info hash_info,
 			   subvol_inum dir, struct qstr *name,
-			   u64 *target, unsigned *type)
+			   u64 *target, unsigned *type, u32 snapshot)
 {
 	struct btree_iter iter;
 	struct bkey_s_c_dirent d;
-	int ret;
-
-	ret = bch2_hash_lookup(trans, &iter, bch2_dirent_hash_desc,
-			       &hash_info, dir, name, 0);
+	int ret = bch2_hash_lookup_in_snapshot(trans, &iter, bch2_dirent_hash_desc,
+			       &hash_info, dir, name, 0, snapshot);
 	if (ret)
 		return ret;
 
@@ -144,34 +142,6 @@ static int __lookup_dirent(struct btree_trans *trans,
 	return 0;
 }
 
-static int __write_inode(struct btree_trans *trans,
-			 struct bch_inode_unpacked *inode,
-			 u32 snapshot)
-{
-	struct bkey_inode_buf *inode_p =
-		bch2_trans_kmalloc(trans, sizeof(*inode_p));
-
-	if (IS_ERR(inode_p))
-		return PTR_ERR(inode_p);
-
-	bch2_inode_pack(inode_p, inode);
-	inode_p->inode.k.p.snapshot = snapshot;
-
-	return bch2_btree_insert_nonextent(trans, BTREE_ID_inodes,
-				&inode_p->inode.k_i,
-				BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
-}
-
-static int fsck_write_inode(struct btree_trans *trans,
-			    struct bch_inode_unpacked *inode,
-			    u32 snapshot)
-{
-	int ret = commit_do(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
-			    __write_inode(trans, inode, snapshot));
-	bch_err_fn(trans->c, ret);
-	return ret;
-}
-
 static int __remove_dirent(struct btree_trans *trans, struct bpos pos)
 {
 	struct bch_fs *c = trans->c;
@@ -224,15 +194,16 @@ static int lookup_lostfound(struct btree_trans *trans, u32 snapshot,
 
 	struct bch_inode_unpacked root_inode;
 	struct bch_hash_info root_hash_info;
-	ret = lookup_inode(trans, root_inum.inum, &root_inode, &snapshot);
+	u32 root_inode_snapshot = snapshot;
+	ret = lookup_inode(trans, root_inum.inum, &root_inode, &root_inode_snapshot);
 	bch_err_msg(c, ret, "looking up root inode");
 	if (ret)
 		return ret;
 
 	root_hash_info = bch2_hash_info_init(c, &root_inode);
 
-	ret = __lookup_dirent(trans, root_hash_info, root_inum,
-			      &lostfound_str, &inum, &d_type);
+	ret = lookup_dirent_in_snapshot(trans, root_hash_info, root_inum,
+			      &lostfound_str, &inum, &d_type, snapshot);
 	if (bch2_err_matches(ret, ENOENT))
 		goto create_lostfound;
 
@@ -250,7 +221,8 @@ static int lookup_lostfound(struct btree_trans *trans, u32 snapshot,
 	 * shouldn't exist here:
 	 */
 	ret = lookup_inode(trans, inum, lostfound, &snapshot);
-	bch_err_msg(c, ret, "looking up lost+found");
+	bch_err_msg(c, ret, "looking up lost+found %llu:%u in (root inode %llu, snapshot root %u)",
+		    inum, snapshot, root_inum.inum, bch2_snapshot_root(c, snapshot));
 	return ret;
 
 create_lostfound:
@@ -312,7 +284,7 @@ static int reattach_inode(struct btree_trans *trans,
 	if (S_ISDIR(inode->bi_mode)) {
 		lostfound.bi_nlink++;
 
-		ret = __write_inode(trans, &lostfound, U32_MAX);
+		ret = __bch2_fsck_write_inode(trans, &lostfound, U32_MAX);
 		if (ret)
 			return ret;
 	}
@@ -334,7 +306,7 @@ static int reattach_inode(struct btree_trans *trans,
 	inode->bi_dir		= lostfound.bi_inum;
 	inode->bi_dir_offset	= dir_offset;
 
-	return __write_inode(trans, inode, inode_snapshot);
+	return __bch2_fsck_write_inode(trans, inode, inode_snapshot);
 }
 
 static int remove_backpointer(struct btree_trans *trans,
@@ -722,7 +694,7 @@ static int hash_redo_key(struct btree_trans *trans,
 	delete->k.p = k_iter->pos;
 	return  bch2_btree_iter_traverse(k_iter) ?:
 		bch2_trans_update(trans, k_iter, delete, 0) ?:
-		bch2_hash_set_snapshot(trans, desc, hash_info,
+		bch2_hash_set_in_snapshot(trans, desc, hash_info,
 				       (subvol_inum) { 0, k.k->p.inode },
 				       k.k->p.snapshot, tmp,
 				       BCH_HASH_SET_MUST_CREATE,
@@ -861,7 +833,8 @@ static int check_inode(struct btree_trans *trans,
 
 		u.bi_flags &= ~BCH_INODE_i_size_dirty|BCH_INODE_unlinked;
 
-		ret = __write_inode(trans, &u, iter->pos.snapshot);
+		ret = __bch2_fsck_write_inode(trans, &u, iter->pos.snapshot);
+
 		bch_err_msg(c, ret, "in fsck updating inode");
 		if (ret)
 			return ret;
@@ -950,8 +923,33 @@ static int check_inode(struct btree_trans *trans,
 		do_update = true;
 	}
 
+	if (u.bi_subvol) {
+		struct bch_subvolume s;
+
+		ret = bch2_subvolume_get(trans, u.bi_subvol, false, 0, &s);
+		if (ret && !bch2_err_matches(ret, ENOENT))
+			goto err;
+
+		if (fsck_err_on(ret,
+				c, inode_bi_subvol_missing,
+				"inode %llu:%u bi_subvol points to missing subvolume %u",
+				u.bi_inum, k.k->p.snapshot, u.bi_subvol) ||
+		    fsck_err_on(le64_to_cpu(s.inode) != u.bi_inum ||
+				!bch2_snapshot_is_ancestor(c, le32_to_cpu(s.snapshot),
+							   k.k->p.snapshot),
+				c, inode_bi_subvol_wrong,
+				"inode %llu:%u points to subvol %u, but subvol points to %llu:%u",
+				u.bi_inum, k.k->p.snapshot, u.bi_subvol,
+				le64_to_cpu(s.inode),
+				le32_to_cpu(s.snapshot))) {
+			u.bi_subvol = 0;
+			u.bi_parent_subvol = 0;
+			do_update = true;
+		}
+	}
+
 	if (do_update) {
-		ret = __write_inode(trans, &u, iter->pos.snapshot);
+		ret = __bch2_fsck_write_inode(trans, &u, iter->pos.snapshot);
 		bch_err_msg(c, ret, "in fsck updating inode");
 		if (ret)
 			return ret;
@@ -1032,7 +1030,7 @@ static int check_i_sectors(struct btree_trans *trans, struct inode_walker *w)
 				w->last_pos.inode, i->snapshot,
 				i->inode.bi_sectors, i->count)) {
 			i->inode.bi_sectors = i->count;
-			ret = fsck_write_inode(trans, &i->inode, i->snapshot);
+			ret = bch2_fsck_write_inode(trans, &i->inode, i->snapshot);
 			if (ret)
 				break;
 		}
@@ -1481,7 +1479,7 @@ static int check_subdir_count(struct btree_trans *trans, struct inode_walker *w)
 				"directory %llu:%u with wrong i_nlink: got %u, should be %llu",
 				w->last_pos.inode, i->snapshot, i->inode.bi_nlink, i->count)) {
 			i->inode.bi_nlink = i->count;
-			ret = fsck_write_inode(trans, &i->inode, i->snapshot);
+			ret = bch2_fsck_write_inode(trans, &i->inode, i->snapshot);
 			if (ret)
 				break;
 		}
@@ -1491,16 +1489,15 @@ fsck_err:
 	return ret ?: trans_was_restarted(trans, restart_count);
 }
 
-static int check_dirent_target(struct btree_trans *trans,
-			       struct btree_iter *iter,
-			       struct bkey_s_c_dirent d,
-			       struct bch_inode_unpacked *target,
-			       u32 target_snapshot)
+static int check_inode_backpointer(struct btree_trans *trans,
+				   struct btree_iter *iter,
+				   struct bkey_s_c_dirent d,
+				   struct bch_inode_unpacked *target,
+				   u32 target_snapshot)
 {
 	struct bch_fs *c = trans->c;
-	struct bkey_i_dirent *n;
-	struct printbuf buf = PRINTBUF;
 	struct btree_iter bp_iter = { NULL };
+	struct printbuf buf = PRINTBUF;
 	int ret = 0;
 
 	if (!target->bi_dir &&
@@ -1508,7 +1505,7 @@ static int check_dirent_target(struct btree_trans *trans,
 		target->bi_dir		= d.k->p.inode;
 		target->bi_dir_offset	= d.k->p.offset;
 
-		ret = __write_inode(trans, target, target_snapshot);
+		ret = __bch2_fsck_write_inode(trans, target, target_snapshot);
 		if (ret)
 			goto err;
 	}
@@ -1548,7 +1545,7 @@ static int check_dirent_target(struct btree_trans *trans,
 			target->bi_nlink++;
 			target->bi_flags &= ~BCH_INODE_unlinked;
 
-			ret = __write_inode(trans, target, target_snapshot);
+			ret = __bch2_fsck_write_inode(trans, target, target_snapshot);
 			if (ret)
 				goto err;
 		}
@@ -1566,11 +1563,34 @@ static int check_dirent_target(struct btree_trans *trans,
 			target->bi_dir		= d.k->p.inode;
 			target->bi_dir_offset	= d.k->p.offset;
 
-			ret = __write_inode(trans, target, target_snapshot);
+			ret = __bch2_fsck_write_inode(trans, target, target_snapshot);
 			if (ret)
 				goto err;
 		}
 	}
+out:
+err:
+fsck_err:
+	bch2_trans_iter_exit(trans, &bp_iter);
+	printbuf_exit(&buf);
+	bch_err_fn(c, ret);
+	return ret;
+}
+
+static int check_dirent_target(struct btree_trans *trans,
+			       struct btree_iter *iter,
+			       struct bkey_s_c_dirent d,
+			       struct bch_inode_unpacked *target,
+			       u32 target_snapshot)
+{
+	struct bch_fs *c = trans->c;
+	struct bkey_i_dirent *n;
+	struct printbuf buf = PRINTBUF;
+	int ret = 0;
+
+	ret = check_inode_backpointer(trans, iter, d, target, target_snapshot);
+	if (ret)
+		goto err;
 
 	if (fsck_err_on(d.v->d_type != inode_d_type(target),
 			c, dirent_d_type_wrong,
@@ -1614,15 +1634,65 @@ static int check_dirent_target(struct btree_trans *trans,
 
 		d = dirent_i_to_s_c(n);
 	}
-out:
 err:
 fsck_err:
-	bch2_trans_iter_exit(trans, &bp_iter);
 	printbuf_exit(&buf);
 	bch_err_fn(c, ret);
 	return ret;
 }
 
+static int check_subvol_dirent(struct btree_trans *trans, struct btree_iter *iter,
+			       struct bkey_s_c_dirent d)
+{
+	struct bch_fs *c = trans->c;
+	struct bch_inode_unpacked subvol_root;
+	u32 target_subvol = le32_to_cpu(d.v->d_child_subvol);
+	u32 target_snapshot;
+	u64 target_inum;
+	int ret = 0;
+
+	ret = subvol_lookup(trans, target_subvol,
+			      &target_snapshot, &target_inum);
+	if (ret && !bch2_err_matches(ret, ENOENT))
+		return ret;
+
+	if (fsck_err_on(ret, c, dirent_to_missing_subvol,
+			"dirent points to missing subvolume %u",
+			le32_to_cpu(d.v->d_child_subvol)))
+		return __remove_dirent(trans, d.k->p);
+
+	ret = lookup_inode(trans, target_inum,
+			   &subvol_root, &target_snapshot);
+	if (ret && !bch2_err_matches(ret, ENOENT))
+		return ret;
+
+	if (fsck_err_on(ret, c, subvol_to_missing_root,
+			"subvolume %u points to missing subvolume root %llu",
+			target_subvol,
+			target_inum)) {
+		bch_err(c, "repair not implemented yet");
+		return -EINVAL;
+	}
+
+	if (fsck_err_on(subvol_root.bi_subvol != target_subvol,
+			c, subvol_root_wrong_bi_subvol,
+			"subvol root %llu has wrong bi_subvol field: got %u, should be %u",
+			target_inum,
+			subvol_root.bi_subvol, target_subvol)) {
+		subvol_root.bi_subvol = target_subvol;
+		ret = __bch2_fsck_write_inode(trans, &subvol_root, target_snapshot);
+		if (ret)
+			return ret;
+	}
+
+	ret = check_dirent_target(trans, iter, d, &subvol_root,
+				  target_snapshot);
+	if (ret)
+		return ret;
+fsck_err:
+	return ret;
+}
+
 static int check_dirent(struct btree_trans *trans, struct btree_iter *iter,
 			struct bkey_s_c k,
 			struct bch_hash_info *hash_info,
@@ -1707,50 +1777,7 @@ static int check_dirent(struct btree_trans *trans, struct btree_iter *iter,
 	d = bkey_s_c_to_dirent(k);
 
 	if (d.v->d_type == DT_SUBVOL) {
-		struct bch_inode_unpacked subvol_root;
-		u32 target_subvol = le32_to_cpu(d.v->d_child_subvol);
-		u32 target_snapshot;
-		u64 target_inum;
-
-		ret = subvol_lookup(trans, target_subvol,
-				      &target_snapshot, &target_inum);
-		if (ret && !bch2_err_matches(ret, ENOENT))
-			goto err;
-
-		if (fsck_err_on(ret, c, dirent_to_missing_subvol,
-				"dirent points to missing subvolume %u",
-				le32_to_cpu(d.v->d_child_subvol))) {
-			ret = __remove_dirent(trans, d.k->p);
-			goto err;
-		}
-
-		ret = lookup_inode(trans, target_inum,
-				   &subvol_root, &target_snapshot);
-		if (ret && !bch2_err_matches(ret, ENOENT))
-			goto err;
-
-		if (fsck_err_on(ret, c, subvol_to_missing_root,
-				"subvolume %u points to missing subvolume root %llu",
-				target_subvol,
-				target_inum)) {
-			bch_err(c, "repair not implemented yet");
-			ret = -EINVAL;
-			goto err;
-		}
-
-		if (fsck_err_on(subvol_root.bi_subvol != target_subvol,
-				c, subvol_root_wrong_bi_subvol,
-				"subvol root %llu has wrong bi_subvol field: got %u, should be %u",
-				target_inum,
-				subvol_root.bi_subvol, target_subvol)) {
-			subvol_root.bi_subvol = target_subvol;
-			ret = __write_inode(trans, &subvol_root, target_snapshot);
-			if (ret)
-				goto err;
-		}
-
-		ret = check_dirent_target(trans, iter, d, &subvol_root,
-					  target_snapshot);
+		ret = check_subvol_dirent(trans, iter, d);
 		if (ret)
 			goto err;
 	} else {
@@ -1776,12 +1803,11 @@ static int check_dirent(struct btree_trans *trans, struct btree_iter *iter,
 			if (ret)
 				goto err;
 		}
-	}
-
-	if (d.v->d_type == DT_DIR)
-		for_each_visible_inode(c, s, dir, equiv.snapshot, i)
-			i->count++;
 
+		if (d.v->d_type == DT_DIR)
+			for_each_visible_inode(c, s, dir, equiv.snapshot, i)
+				i->count++;
+	}
 out:
 err:
 fsck_err:
@@ -1919,7 +1945,7 @@ static int check_root_trans(struct btree_trans *trans)
 				0, NULL);
 		root_inode.bi_inum = inum;
 
-		ret = __write_inode(trans, &root_inode, snapshot);
+		ret = __bch2_fsck_write_inode(trans, &root_inode, snapshot);
 		bch_err_msg(c, ret, "writing root inode");
 	}
 err:
@@ -2291,7 +2317,7 @@ static int check_nlinks_update_inode(struct btree_trans *trans, struct btree_ite
 			u.bi_inum, bch2_d_types[mode_to_type(u.bi_mode)],
 			bch2_inode_nlink_get(&u), link->count)) {
 		bch2_inode_nlink_set(&u, link->count);
-		ret = __write_inode(trans, &u, k.k->p.snapshot);
+		ret = __bch2_fsck_write_inode(trans, &u, k.k->p.snapshot);
 	}
 fsck_err:
 	return ret;