bcachefs: bch2_ec_read_extent() now takes btree_trans

We're not supposed to have more than one btree_trans at a time in a
given thread - that causes recursive locking deadlocks.

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

Author: Kent Overstreet

fs/bcachefs/ec.c

@@ -476,14 +476,10 @@ static int get_stripe_key_trans(struct btree_trans *trans, u64 idx,
 	return ret;
 }
 
-static int get_stripe_key(struct bch_fs *c, u64 idx, struct ec_stripe_buf *stripe)
-{
-	return bch2_trans_run(c, get_stripe_key_trans(trans, idx, stripe));
-}
-
 /* recovery read path: */
-int bch2_ec_read_extent(struct bch_fs *c, struct bch_read_bio *rbio)
+int bch2_ec_read_extent(struct btree_trans *trans, struct bch_read_bio *rbio)
 {
+	struct bch_fs *c = trans->c;
 	struct ec_stripe_buf *buf;
 	struct closure cl;
 	struct bch_stripe *v;
@@ -498,7 +494,7 @@ int bch2_ec_read_extent(struct bch_fs *c, struct bch_read_bio *rbio)
 	if (!buf)
 		return -BCH_ERR_ENOMEM_ec_read_extent;
 
-	ret = get_stripe_key(c, rbio->pick.ec.idx, buf);
+	ret = lockrestart_do(trans, get_stripe_key_trans(trans, rbio->pick.ec.idx, buf));
 	if (ret) {
 		bch_err_ratelimited(c,
 			"error doing reconstruct read: error %i looking up stripe", ret);

fs/bcachefs/ec.h

@@ -199,7 +199,7 @@ struct ec_stripe_head {
 	struct ec_stripe_new	*s;
 };
 
-int bch2_ec_read_extent(struct bch_fs *, struct bch_read_bio *);
+int bch2_ec_read_extent(struct btree_trans *, struct bch_read_bio *);
 
 void *bch2_writepoint_ec_buf(struct bch_fs *, struct write_point *);
 

fs/bcachefs/io_read.c

@@ -1025,7 +1025,7 @@ int __bch2_read_extent(struct btree_trans *trans, struct bch_read_bio *orig,
 		trans->notrace_relock_fail = true;
 	} else {
 		/* Attempting reconstruct read: */
-		if (bch2_ec_read_extent(c, rbio)) {
+		if (bch2_ec_read_extent(trans, rbio)) {
 			bch2_rbio_error(rbio, READ_RETRY_AVOID, BLK_STS_IOERR);
 			goto out;
 		}