Commit d2fda304 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: __lookup_dirent() works in snapshot, not subvol 



Add a new helper, bch2_hash_lookup_in_snapshot(), for when we're not
operating in a subvolume and already have a snapshot ID, and then use it
in lookup_lostfound() -> __lookup_dirent().

This is a bugfix - lookup_lostfound() doesn't take a subvolume ID, we
were passing a nonsense subvolume ID before, and don't have one to pass
since we may be operating in an interior snapshot node that doesn't have
a subvolume ID.

Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 096386a5

fs/bcachefs/fsck.c

+12 −11
Original line number Diff line number Diff line
@@ -119,22 +119,19 @@ static int lookup_inode(struct btree_trans *trans, u64 inode_nr, 
	if (!ret)

		*snapshot = iter.pos.snapshot;

err:

	bch_err_msg(trans->c, ret, "fetching inode %llu:%u", inode_nr, *snapshot);

	bch2_trans_iter_exit(trans, &iter);

	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;
@@ -225,15 +222,16 @@ 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 +248,10 @@ static int lookup_lostfound(struct btree_trans *trans, u32 snapshot, 
	 * The bch2_check_dirents pass has already run, dangling dirents

	 * shouldn't exist here:

	 */

	return lookup_inode(trans, inum, lostfound, &snapshot);

	ret = lookup_inode(trans, inum, lostfound, &snapshot);

	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:

	/*

fs/bcachefs/str_hash.h

+15 −7
Original line number Diff line number Diff line
@@ -160,21 +160,16 @@ static inline bool is_visible_key(struct bch_hash_desc desc, subvol_inum inum, s 
}



static __always_inline int

bch2_hash_lookup(struct btree_trans *trans,

bch2_hash_lookup_in_snapshot(struct btree_trans *trans,

		 struct btree_iter *iter,

		 const struct bch_hash_desc desc,

		 const struct bch_hash_info *info,

		 subvol_inum inum, const void *key,

		 unsigned flags)

		 unsigned flags, u32 snapshot)

{

	struct bkey_s_c k;

	u32 snapshot;

	int ret;



	ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);

	if (ret)

		return ret;



	for_each_btree_key_upto_norestart(trans, *iter, desc.btree_id,

			   SPOS(inum.inum, desc.hash_key(info, key), snapshot),

			   POS(inum.inum, U64_MAX),
@@ -194,6 +189,19 @@ bch2_hash_lookup(struct btree_trans *trans, 
	return ret ?: -BCH_ERR_ENOENT_str_hash_lookup;

}



static __always_inline int

bch2_hash_lookup(struct btree_trans *trans,

		 struct btree_iter *iter,

		 const struct bch_hash_desc desc,

		 const struct bch_hash_info *info,

		 subvol_inum inum, const void *key,

		 unsigned flags)

{

	u32 snapshot;

	return  bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot) ?:

		bch2_hash_lookup_in_snapshot(trans, iter, desc, info, inum, key, flags, snapshot);

}



static __always_inline int

bch2_hash_hole(struct btree_trans *trans,

	       struct btree_iter *iter,