Commit 81ed9ce3 authored by Kent Overstreet's avatar Kent Overstreet Committed by Kent Overstreet
Browse files

bcachefs: Per subvolume lost+found 



On existing filesystems, we have a single global lost+found. Introducing
subvolumes means we need to introduce per subvolume lost+found
directories, because inodes are added to lost+found by their inode
number, and inode numbers are now only unique within a subvolume.

This patch adds support to fsck for per subvolume lost+found.

Signed-off-by: default avatarKent Overstreet <kent.overstreet@gmail.com>
parent b9e1adf5

fs/bcachefs/fsck.c

+84 −10
Original line number Diff line number Diff line
@@ -39,6 +39,71 @@ static s64 bch2_count_inode_sectors(struct btree_trans *trans, u64 inum) 
	return ret ?: sectors;

}



static int __snapshot_lookup_subvol(struct btree_trans *trans, u32 snapshot,

				    u32 *subvol)

{

	struct btree_iter iter;

	struct bkey_s_c k;

	int ret;



	bch2_trans_iter_init(trans, &iter, BTREE_ID_snapshots,

			     POS(0, snapshot), 0);

	k = bch2_btree_iter_peek_slot(&iter);

	ret = bkey_err(k);

	if (ret)

		goto err;



	if (k.k->type != KEY_TYPE_snapshot) {

		bch_err(trans->c, "snapshot %u not fonud", snapshot);

		ret = -ENOENT;

		goto err;

	}



	*subvol = le32_to_cpu(bkey_s_c_to_snapshot(k).v->subvol);

err:

	bch2_trans_iter_exit(trans, &iter);

	return ret;



}



static int snapshot_lookup_subvol(struct btree_trans *trans, u32 snapshot,

				  u32 *subvol)

{

	return lockrestart_do(trans, __snapshot_lookup_subvol(trans, snapshot, subvol));

}



static int __subvol_lookup_root(struct btree_trans *trans, u32 subvol,

				u64 *inum)

{

	struct btree_iter iter;

	struct bkey_s_c k;

	int ret;



	bch2_trans_iter_init(trans, &iter, BTREE_ID_subvolumes,

			     POS(0, subvol), 0);

	k = bch2_btree_iter_peek_slot(&iter);

	ret = bkey_err(k);

	if (ret)

		goto err;



	if (k.k->type != KEY_TYPE_subvolume) {

		bch_err(trans->c, "subvolume %u not fonud", subvol);

		ret = -ENOENT;

		goto err;

	}



	*inum = le64_to_cpu(bkey_s_c_to_subvolume(k).v->inode);

err:

	bch2_trans_iter_exit(trans, &iter);

	return ret;



}



static int subvol_lookup_root(struct btree_trans *trans, u32 subvol, u64 *inum)

{

	return lockrestart_do(trans, __subvol_lookup_root(trans, subvol, inum));

}



static int __lookup_inode(struct btree_trans *trans, u64 inode_nr,

			  struct bch_inode_unpacked *inode,

			  u32 *snapshot)
@@ -136,6 +201,7 @@ static int remove_dirent(struct btree_trans *trans, struct bpos pos) 


/* Get lost+found, create if it doesn't exist: */

static int lookup_lostfound(struct btree_trans *trans,

			    u32 subvol,

			    struct bch_inode_unpacked *lostfound)

{

	struct bch_fs *c = trans->c;
@@ -146,12 +212,14 @@ static int lookup_lostfound(struct btree_trans *trans, 
	u32 snapshot;

	int ret;



	ret = lookup_inode(trans, BCACHEFS_ROOT_INO, &root, &snapshot);

	ret = subvol_lookup_root(trans, subvol, &inum);



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

	if (ret && ret != -ENOENT)

		return ret;



	root_hash_info = bch2_hash_info_init(c, &root);

	inum = bch2_dirent_lookup(c, BCACHEFS_ROOT_INO, &root_hash_info,

	inum = bch2_dirent_lookup(c, root.bi_inum, &root_hash_info,

				  &lostfound_str);

	if (!inum) {

		bch_notice(c, "creating lost+found");
@@ -188,16 +256,22 @@ static int lookup_lostfound(struct btree_trans *trans, 
}



static int reattach_inode(struct btree_trans *trans,

			  struct bch_inode_unpacked *inode)

			  struct bch_inode_unpacked *inode,

			  u32 snapshot)

{

	struct bch_hash_info dir_hash;

	struct bch_inode_unpacked lostfound;

	char name_buf[20];

	struct qstr name;

	u64 dir_offset = 0;

	u32 subvol;

	int ret;



	ret = lookup_lostfound(trans, &lostfound);

	ret = snapshot_lookup_subvol(trans, snapshot, &subvol);

	if (ret)

		return ret;



	ret = lookup_lostfound(trans, subvol, &lostfound);

	if (ret)

		return ret;
@@ -1063,10 +1137,10 @@ static int path_down(struct pathbuf *p, u64 inum) 


static int check_path(struct btree_trans *trans,

		      struct pathbuf *p,

		      struct bch_inode_unpacked *inode)

		      struct bch_inode_unpacked *inode,

		      u32 snapshot)

{

	struct bch_fs *c = trans->c;

	u32 snapshot;

	size_t i;

	int ret = 0;
@@ -1085,7 +1159,7 @@ static int check_path(struct btree_trans *trans, 
				     inode->bi_nlink,

				     inode->bi_dir,

				     inode->bi_dir_offset))

				ret = reattach_inode(trans, inode);

				ret = reattach_inode(trans, inode, snapshot);

			break;

		}

		ret = 0;
@@ -1114,7 +1188,7 @@ static int check_path(struct btree_trans *trans, 
				break;

			}



			ret = reattach_inode(trans, inode);

			ret = reattach_inode(trans, inode, snapshot);

			break;

		}
@@ -1160,7 +1234,7 @@ static int check_directory_structure(struct bch_fs *c) 
			break;

		}



		ret = check_path(&trans, &path, &u);

		ret = check_path(&trans, &path, &u, iter.pos.snapshot);

		if (ret)

			break;

	}