Commit bade9711 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: Split out check_unreachable_inodes() pass 



With inode backpointers, we can write a very simple
check_unreachable_inodes() pass that only looks for non-unlinked inodes
that are missing backpointers, and reattaches them.

This simplifies check_directory_structure() so that it's now only
checking for directory structure loops,

Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent bf4baaa0

fs/bcachefs/fsck.c

+65 −35
Original line number Diff line number Diff line
@@ -1292,6 +1292,58 @@ int bch2_check_inodes(struct bch_fs *c) 
	return ret;

}



static int check_unreachable_inode(struct btree_trans *trans,

				   struct btree_iter *iter,

				   struct bkey_s_c k)

{

	struct bch_fs *c = trans->c;

	struct printbuf buf = PRINTBUF;

	int ret = 0;



	if (!bkey_is_inode(k.k))

		return 0;



	struct bch_inode_unpacked inode;

	BUG_ON(bch2_inode_unpack(k, &inode));



	if (inode.bi_subvol)

		return 0;



	if (inode.bi_flags & BCH_INODE_unlinked)

		return 0;



	if (fsck_err_on(!inode.bi_dir,

			trans, inode_unreachable,

			"unreachable inode:\n%s",

			(printbuf_reset(&buf),

			 bch2_bkey_val_to_text(&buf, c, k),

			 buf.buf)))

		ret = reattach_inode(trans, &inode);

fsck_err:

	printbuf_exit(&buf);

	return ret;

}



/*

 * Reattach unreachable (but not unlinked) inodes

 *

 * Run after check_inodes() and check_dirents(), so we node that inode

 * backpointer fields point to valid dirents, and every inode that has a dirent

 * that points to it has its backpointer field set - so we're just looking for

 * non-unlinked inodes without backpointers:

 */

int bch2_check_unreachable_inodes(struct bch_fs *c)

{

	int ret = bch2_trans_run(c,

		for_each_btree_key_commit(trans, iter, BTREE_ID_inodes,

				POS_MIN,

				BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k,

				NULL, NULL, BCH_TRANS_COMMIT_no_enospc,

			check_unreachable_inode(trans, &iter, k)));

	bch_err_fn(c, ret);

	return ret;

}



static inline bool btree_matches_i_mode(enum btree_id btree, unsigned mode)

{

	switch (btree) {
@@ -2450,22 +2502,6 @@ static int check_subvol_path(struct btree_trans *trans, struct btree_iter *iter, 
		if (ret)

			break;



		/*

		 * We've checked that inode backpointers point to valid dirents;

		 * here, it's sufficient to check that the subvolume root has a

		 * dirent:

		 */

		if (fsck_err_on(!subvol_root.bi_dir,

				trans, subvol_unreachable,

				"unreachable subvolume %s",

				(bch2_bkey_val_to_text(&buf, c, s.s_c),

				 prt_newline(&buf),

				 bch2_inode_unpacked_to_text(&buf, &subvol_root),

				 buf.buf))) {

			ret = reattach_subvol(trans, s);

			break;

		}



		u32 parent = le32_to_cpu(s.v->fs_path_parent);



		if (darray_u32_has(&subvol_path, parent)) {
@@ -2526,12 +2562,6 @@ static bool path_is_dup(pathbuf *p, u64 inum, u32 snapshot) 
	return false;

}



/*

 * Check that a given inode is reachable from its subvolume root - we already

 * verified subvolume connectivity:

 *

 * XXX: we should also be verifying that inodes are in the right subvolumes

 */

static int check_path(struct btree_trans *trans, pathbuf *p, struct bkey_s_c inode_k)

{

	struct bch_fs *c = trans->c;
@@ -2545,6 +2575,9 @@ static int check_path(struct btree_trans *trans, pathbuf *p, struct bkey_s_c ino 


	BUG_ON(bch2_inode_unpack(inode_k, &inode));



	if (!S_ISDIR(inode.bi_mode))

		return 0;



	while (!inode.bi_subvol) {

		struct btree_iter dirent_iter;

		struct bkey_s_c_dirent d;
@@ -2559,21 +2592,15 @@ static int check_path(struct btree_trans *trans, pathbuf *p, struct bkey_s_c ino 
			bch2_trans_iter_exit(trans, &dirent_iter);



		if (bch2_err_matches(ret, ENOENT)) {

			ret = 0;

			if (fsck_err(trans, inode_unreachable,

				     "unreachable inode\n%s",

				     (printbuf_reset(&buf),

				      bch2_bkey_val_to_text(&buf, c, inode_k),

				      buf.buf)))

				ret = reattach_inode(trans, &inode);

			printbuf_reset(&buf);

			bch2_bkey_val_to_text(&buf, c, inode_k);

			bch_err(c, "unreachable inode in check_directory_structure: %s\n%s",

				bch2_err_str(ret), buf.buf);

			goto out;

		}



		bch2_trans_iter_exit(trans, &dirent_iter);



		if (!S_ISDIR(inode.bi_mode))

			break;



		ret = darray_push(p, ((struct pathbuf_entry) {

			.inum		= inode.bi_inum,

			.snapshot	= snapshot,
@@ -2626,9 +2653,8 @@ static int check_path(struct btree_trans *trans, pathbuf *p, struct bkey_s_c ino 
}



/*

 * Check for unreachable inodes, as well as loops in the directory structure:

 * After bch2_check_dirents(), if an inode backpointer doesn't exist that means it's

 * unreachable:

 * Check for loops in the directory structure: all other connectivity issues

 * have been fixed by prior passes

 */

int bch2_check_directory_structure(struct bch_fs *c)

{
@@ -2756,6 +2782,10 @@ static int check_nlinks_find_hardlinks(struct bch_fs *c, 
			if (S_ISDIR(u.bi_mode))

				continue;



			/*

			 * Previous passes ensured that bi_nlink is nonzero if

			 * it had multiple hardlinks:

			 */

			if (!u.bi_nlink)

				continue;

fs/bcachefs/fsck.h

+1 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ int bch2_check_dirents(struct bch_fs *); 
int bch2_check_xattrs(struct bch_fs *);

int bch2_check_root(struct bch_fs *);

int bch2_check_subvolume_structure(struct bch_fs *);

int bch2_check_unreachable_inodes(struct bch_fs *);

int bch2_check_directory_structure(struct bch_fs *);

int bch2_check_nlinks(struct bch_fs *);

int bch2_fix_reflink_p(struct bch_fs *);

fs/bcachefs/recovery_passes_types.h

+1 −0
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ 
	x(check_dirents,			27, PASS_FSCK)			\

	x(check_xattrs,				28, PASS_FSCK)			\

	x(check_root,				29, PASS_ONLINE|PASS_FSCK)	\

	x(check_unreachable_inodes,		40, PASS_ONLINE|PASS_FSCK)	\

	x(check_subvolume_structure,		36, PASS_ONLINE|PASS_FSCK)	\

	x(check_directory_structure,		30, PASS_ONLINE|PASS_FSCK)	\

	x(check_nlinks,				31, PASS_FSCK)			\