bcachefs: Don't delete unlinked inodes before logged op resume

Previously, check_inode() would delete unlinked inodes if they weren't
on the deleted list - this code dating from before there was a deleted
list.

But, if we crash during a logged op (truncate or finsert/fcollapse) of
an unlinked file, logged op resume will get confused if the inode has
already been deleted - instead, just add it to the deleted list if it
needs to be there; delete_dead_inodes runs after logged op resume.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/fsck.c

@@ -1049,26 +1049,39 @@ static int check_inode(struct btree_trans *trans,
 	}
 
 	if (u.bi_flags & BCH_INODE_unlinked) {
-		ret = check_inode_deleted_list(trans, k.k->p);
-		if (ret < 0)
-			return ret;
+		if (!test_bit(BCH_FS_started, &c->flags)) {
+			/*
+			 * If we're not in online fsck, don't delete unlinked
+			 * inodes, just make sure they're on the deleted list.
+			 *
+			 * They might be referred to by a logged operation -
+			 * i.e. we might have crashed in the middle of a
+			 * truncate on an unlinked but open file - so we want to
+			 * let the delete_dead_inodes kill it after resuming
+			 * logged ops.
+			 */
+			ret = check_inode_deleted_list(trans, k.k->p);
+			if (ret < 0)
+				return ret;
 
-		fsck_err_on(!ret,
-			    trans, unlinked_inode_not_on_deleted_list,
-			    "inode %llu:%u unlinked, but not on deleted list",
-			    u.bi_inum, k.k->p.snapshot);
-		ret = 0;
-	}
+			fsck_err_on(!ret,
+				    trans, unlinked_inode_not_on_deleted_list,
+				    "inode %llu:%u unlinked, but not on deleted list",
+				    u.bi_inum, k.k->p.snapshot);
 
-	if (u.bi_flags & BCH_INODE_unlinked &&
-	    !bch2_inode_is_open(c, k.k->p) &&
-	    (!c->sb.clean ||
-	     fsck_err(trans, inode_unlinked_but_clean,
-		      "filesystem marked clean, but inode %llu unlinked",
-		      u.bi_inum))) {
-		ret = bch2_inode_rm_snapshot(trans, u.bi_inum, iter->pos.snapshot);
-		bch_err_msg(c, ret, "in fsck deleting inode");
-		return ret;
+			ret = bch2_btree_bit_mod_buffered(trans, BTREE_ID_deleted_inodes, k.k->p, 1);
+			if (ret)
+				goto err;
+		} else {
+			if (fsck_err_on(bch2_inode_is_open(c, k.k->p),
+					trans, inode_unlinked_and_not_open,
+				      "inode %llu%u unlinked and not open",
+				      u.bi_inum, u.bi_snapshot)) {
+				ret = bch2_inode_rm_snapshot(trans, u.bi_inum, iter->pos.snapshot);
+				bch_err_msg(c, ret, "in fsck deleting inode");
+				return ret;
+			}
+		}
 	}
 
 	if (u.bi_flags & BCH_INODE_i_size_dirty &&

fs/bcachefs/recovery_passes_types.h

@@ -50,7 +50,7 @@
 	x(check_directory_structure,		30, PASS_ONLINE|PASS_FSCK)	\
 	x(check_nlinks,				31, PASS_FSCK)			\
 	x(resume_logged_ops,			23, PASS_ALWAYS)		\
-	x(delete_dead_inodes,			32, PASS_FSCK|PASS_UNCLEAN)	\
+	x(delete_dead_inodes,			32, PASS_ALWAYS)		\
 	x(fix_reflink_p,			33, 0)				\
 	x(set_fs_needs_rebalance,		34, 0)				\
 

fs/bcachefs/sb-errors_format.h

@@ -210,6 +210,7 @@ enum bch_fsck_flags {
 	x(inode_snapshot_mismatch,				196,	0)		\
 	x(inode_unlinked_but_clean,				197,	0)		\
 	x(inode_unlinked_but_nlink_nonzero,			198,	0)		\
+	x(inode_unlinked_and_not_open,				281,	0)		\
 	x(inode_checksum_type_invalid,				199,	0)		\
 	x(inode_compression_type_invalid,			200,	0)		\
 	x(inode_subvol_root_but_not_dir,			201,	0)		\
@@ -292,7 +293,7 @@ enum bch_fsck_flags {
 	x(accounting_key_replicas_nr_devs_0,			278,	FSCK_AUTOFIX)	\
 	x(accounting_key_replicas_nr_required_bad,		279,	FSCK_AUTOFIX)	\
 	x(accounting_key_replicas_devs_unsorted,		280,	FSCK_AUTOFIX)	\
-	x(MAX,							281,	0)
+	x(MAX,							282,	0)
 
 enum bch_sb_error_id {
 #define x(t, n, ...) BCH_FSCK_ERR_##t = n,

fs/bcachefs/super-io.c

@@ -1190,7 +1190,8 @@ static void bch2_sb_ext_to_text(struct printbuf *out, struct bch_sb *sb,
 		le_bitvector_to_cpu(errors_silent, (void *) e->errors_silent, sizeof(e->errors_silent) * 8);
 
 		prt_printf(out, "Errors to silently fix:\t");
-		prt_bitflags_vector(out, bch2_sb_error_strs, errors_silent, sizeof(e->errors_silent) * 8);
+		prt_bitflags_vector(out, bch2_sb_error_strs, errors_silent,
+				    min(BCH_FSCK_ERR_MAX, sizeof(e->errors_silent) * 8));
 		prt_newline(out);
 
 		kfree(errors_silent);