bcachefs: Rework logged op error handling

Initially it was thought that we just wanted to ignore errors from
logged op replay, but it turns out we do need to catch -EROFS, or we'll
go into an infinite loop.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Author: Kent Overstreet

fs/bcachefs/io_misc.c

@@ -224,13 +224,14 @@ void bch2_logged_op_truncate_to_text(struct printbuf *out, struct bch_fs *c, str
 
 static int truncate_set_isize(struct btree_trans *trans,
 			      subvol_inum inum,
-			      u64 new_i_size)
+			      u64 new_i_size,
+			      bool warn)
 {
 	struct btree_iter iter = { NULL };
 	struct bch_inode_unpacked inode_u;
 	int ret;
 
-	ret   = bch2_inode_peek(trans, &iter, &inode_u, inum, BTREE_ITER_intent) ?:
+	ret   = __bch2_inode_peek(trans, &iter, &inode_u, inum, BTREE_ITER_intent, warn) ?:
 		(inode_u.bi_size = new_i_size, 0) ?:
 		bch2_inode_write(trans, &iter, &inode_u);
 
@@ -247,10 +248,11 @@ static int __bch2_resume_logged_op_truncate(struct btree_trans *trans,
 	struct bkey_i_logged_op_truncate *op = bkey_i_to_logged_op_truncate(op_k);
 	subvol_inum inum = { le32_to_cpu(op->v.subvol), le64_to_cpu(op->v.inum) };
 	u64 new_i_size = le64_to_cpu(op->v.new_i_size);
+	bool warn_errors = i_sectors_delta != NULL;
 	int ret;
 
 	ret = commit_do(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
-			truncate_set_isize(trans, inum, new_i_size));
+			truncate_set_isize(trans, inum, new_i_size, i_sectors_delta != NULL));
 	if (ret)
 		goto err;
 
@@ -263,8 +265,8 @@ static int __bch2_resume_logged_op_truncate(struct btree_trans *trans,
 	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
 		ret = 0;
 err:
-	bch2_logged_op_finish(trans, op_k);
-	bch_err_fn(c, ret);
+	if (warn_errors)
+		bch_err_fn(c, ret);
 	return ret;
 }
 
@@ -288,9 +290,14 @@ int bch2_truncate(struct bch_fs *c, subvol_inum inum, u64 new_i_size, u64 *i_sec
 	 * resume only proceeding in one of the snapshots
 	 */
 	down_read(&c->snapshot_create_lock);
-	int ret = bch2_trans_run(c,
-		bch2_logged_op_start(trans, &op.k_i) ?:
-		__bch2_resume_logged_op_truncate(trans, &op.k_i, i_sectors_delta));
+	struct btree_trans *trans = bch2_trans_get(c);
+	int ret = bch2_logged_op_start(trans, &op.k_i);
+	if (ret)
+		goto out;
+	ret = __bch2_resume_logged_op_truncate(trans, &op.k_i, i_sectors_delta);
+	ret = bch2_logged_op_finish(trans, &op.k_i) ?: ret;
+out:
+	bch2_trans_put(trans);
 	up_read(&c->snapshot_create_lock);
 
 	return ret;
@@ -308,7 +315,8 @@ void bch2_logged_op_finsert_to_text(struct printbuf *out, struct bch_fs *c, stru
 	prt_printf(out, " src_offset=%llu",	le64_to_cpu(op.v->src_offset));
 }
 
-static int adjust_i_size(struct btree_trans *trans, subvol_inum inum, u64 offset, s64 len)
+static int adjust_i_size(struct btree_trans *trans, subvol_inum inum,
+			 u64 offset, s64 len, bool warn)
 {
 	struct btree_iter iter;
 	struct bch_inode_unpacked inode_u;
@@ -317,7 +325,7 @@ static int adjust_i_size(struct btree_trans *trans, subvol_inum inum, u64 offset
 	offset	<<= 9;
 	len	<<= 9;
 
-	ret = bch2_inode_peek(trans, &iter, &inode_u, inum, BTREE_ITER_intent);
+	ret = __bch2_inode_peek(trans, &iter, &inode_u, inum, BTREE_ITER_intent, warn);
 	if (ret)
 		return ret;
 
@@ -357,12 +365,22 @@ static int __bch2_resume_logged_op_finsert(struct btree_trans *trans,
 	u64 len = abs(shift);
 	u64 pos = le64_to_cpu(op->v.pos);
 	bool insert = shift > 0;
+	u32 snapshot;
+	bool warn_errors = i_sectors_delta != NULL;
 	int ret = 0;
 
 	ret = bch2_inum_opts_get(trans, inum, &opts);
 	if (ret)
 		return ret;
 
+	/*
+	 * check for missing subvolume before fpunch, as in resume we don't want
+	 * it to be a fatal error
+	 */
+	ret = __bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot, warn_errors);
+	if (ret)
+		return ret;
+
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
 			     POS(inum.inum, 0),
 			     BTREE_ITER_intent);
@@ -373,7 +391,7 @@ case LOGGED_OP_FINSERT_start:
 
 	if (insert) {
 		ret = commit_do(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
-				adjust_i_size(trans, inum, src_offset, len) ?:
+				adjust_i_size(trans, inum, src_offset, len, warn_errors) ?:
 				bch2_logged_op_update(trans, &op->k_i));
 		if (ret)
 			goto err;
@@ -396,11 +414,11 @@ case LOGGED_OP_FINSERT_shift_extents:
 		struct bkey_i delete, *copy;
 		struct bkey_s_c k;
 		struct bpos src_pos = POS(inum.inum, src_offset);
-		u32 snapshot;
 
 		bch2_trans_begin(trans);
 
-		ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
+		ret = __bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot,
+						    warn_errors);
 		if (ret)
 			goto btree_err;
 
@@ -463,12 +481,12 @@ case LOGGED_OP_FINSERT_shift_extents:
 
 	if (!insert) {
 		ret = commit_do(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
-				adjust_i_size(trans, inum, src_offset, shift) ?:
+				adjust_i_size(trans, inum, src_offset, shift, warn_errors) ?:
 				bch2_logged_op_update(trans, &op->k_i));
 	} else {
 		/* We need an inode update to update bi_journal_seq for fsync: */
 		ret = commit_do(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
-				adjust_i_size(trans, inum, 0, 0) ?:
+				adjust_i_size(trans, inum, 0, 0, warn_errors) ?:
 				bch2_logged_op_update(trans, &op->k_i));
 	}
 
@@ -477,9 +495,9 @@ case LOGGED_OP_FINSERT_finish:
 	break;
 	}
 err:
-	bch_err_fn(c, ret);
-	bch2_logged_op_finish(trans, op_k);
 	bch2_trans_iter_exit(trans, &iter);
+	if (warn_errors)
+		bch_err_fn(c, ret);
 	return ret;
 }
 
@@ -508,9 +526,14 @@ int bch2_fcollapse_finsert(struct bch_fs *c, subvol_inum inum,
 	 * resume only proceeding in one of the snapshots
 	 */
 	down_read(&c->snapshot_create_lock);
-	int ret = bch2_trans_run(c,
-		bch2_logged_op_start(trans, &op.k_i) ?:
-		__bch2_resume_logged_op_finsert(trans, &op.k_i, i_sectors_delta));
+	struct btree_trans *trans = bch2_trans_get(c);
+	int ret = bch2_logged_op_start(trans, &op.k_i);
+	if (ret)
+		goto out;
+	ret = __bch2_resume_logged_op_finsert(trans, &op.k_i, i_sectors_delta);
+	ret = bch2_logged_op_finish(trans, &op.k_i) ?: ret;
+out:
+	bch2_trans_put(trans);
 	up_read(&c->snapshot_create_lock);
 
 	return ret;

fs/bcachefs/logged_ops.c

@@ -34,8 +34,6 @@ static int resume_logged_op(struct btree_trans *trans, struct btree_iter *iter,
 			    struct bkey_s_c k)
 {
 	struct bch_fs *c = trans->c;
-	const struct bch_logged_op_fn *fn = logged_op_fn(k.k->type);
-	struct bkey_buf sk;
 	u32 restart_count = trans->restart_count;
 	struct printbuf buf = PRINTBUF;
 	int ret = 0;
@@ -46,13 +44,15 @@ static int resume_logged_op(struct btree_trans *trans, struct btree_iter *iter,
 		    (bch2_bkey_val_to_text(&buf, c, k),
 		     buf.buf));
 
-	if (!fn)
-		return 0;
-
+	struct bkey_buf sk;
 	bch2_bkey_buf_init(&sk);
 	bch2_bkey_buf_reassemble(&sk, c, k);
 
-	fn->resume(trans, sk.k);
+	const struct bch_logged_op_fn *fn = logged_op_fn(sk.k->k.type);
+	if (fn)
+		fn->resume(trans, sk.k);
+
+	ret = bch2_logged_op_finish(trans, sk.k);
 
 	bch2_bkey_buf_exit(&sk, c);
 fsck_err:
@@ -93,7 +93,7 @@ int bch2_logged_op_start(struct btree_trans *trans, struct bkey_i *k)
 			 __bch2_logged_op_start(trans, k));
 }
 
-void bch2_logged_op_finish(struct btree_trans *trans, struct bkey_i *k)
+int bch2_logged_op_finish(struct btree_trans *trans, struct bkey_i *k)
 {
 	int ret = commit_do(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 			    bch2_btree_delete(trans, BTREE_ID_logged_ops, k->k.p, 0));
@@ -113,4 +113,6 @@ void bch2_logged_op_finish(struct btree_trans *trans, struct bkey_i *k)
 				    buf.buf, bch2_err_str(ret));
 		printbuf_exit(&buf);
 	}
+
+	return ret;
 }

fs/bcachefs/logged_ops.h

@@ -15,6 +15,6 @@ static inline int bch2_logged_op_update(struct btree_trans *trans, struct bkey_i
 
 int bch2_resume_logged_ops(struct bch_fs *);
 int bch2_logged_op_start(struct btree_trans *, struct bkey_i *);
-void bch2_logged_op_finish(struct btree_trans *, struct bkey_i *);
+int bch2_logged_op_finish(struct btree_trans *, struct bkey_i *);
 
 #endif /* _BCACHEFS_LOGGED_OPS_H */