bcachefs: Use bch2_trans_begin() more consistently

Upcoming patch will require that a transaction restart is always
immediately followed by bch2_trans_begin().
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

fs/bcachefs/btree_update.h

@@ -114,7 +114,7 @@ static inline int bch2_trans_commit(struct btree_trans *trans,
 		_ret = (_do);						\
 		if (_ret != -EINTR)					\
 			break;						\
-		bch2_trans_reset(_trans, 0);				\
+		bch2_trans_begin(_trans);				\
 	}								\
 									\
 	_ret;								\

fs/bcachefs/fs-io.c

@@ -784,6 +784,8 @@ static void bchfs_read(struct btree_trans *trans, struct btree_iter *iter,
 
 	bch2_bkey_buf_init(&sk);
 retry:
+	bch2_trans_begin(trans);
+
 	while (1) {
 		struct bkey_s_c k;
 		unsigned bytes, sectors, offset_into_extent;
@@ -2541,6 +2543,8 @@ static long bchfs_fcollapse_finsert(struct bch_inode_info *inode,
 		struct bpos atomic_end;
 		unsigned trigger_flags = 0;
 
+		bch2_trans_begin(&trans);
+
 		k = insert
 			? bch2_btree_iter_peek_prev(src)
 			: bch2_btree_iter_peek(src);

fs/bcachefs/fs.c

@@ -911,6 +911,8 @@ static int bch2_fiemap(struct inode *vinode, struct fiemap_extent_info *info,
 	iter = bch2_trans_get_iter(&trans, BTREE_ID_extents,
 				   POS(ei->v.i_ino, start >> 9), 0);
 retry:
+	bch2_trans_begin(&trans);
+
 	while ((k = bch2_btree_iter_peek(iter)).k &&
 	       !(ret = bkey_err(k)) &&
 	       bkey_cmp(iter->pos, end) < 0) {

fs/bcachefs/io.c

@@ -376,14 +376,13 @@ int bch2_fpunch_at(struct btree_trans *trans, struct btree_iter *iter,
 	struct bkey_s_c k;
 	int ret = 0, ret2 = 0;
 
-	while ((k = bch2_btree_iter_peek(iter)).k &&
+	while ((bch2_trans_begin(trans),
+		(k = bch2_btree_iter_peek(iter)).k) &&
 	       bkey_cmp(iter->pos, end) < 0) {
 		struct disk_reservation disk_res =
 			bch2_disk_reservation_init(c, 0);
 		struct bkey_i delete;
 
-		bch2_trans_begin(trans);
-
 		ret = bkey_err(k);
 		if (ret)
 			goto btree_err;
@@ -2278,12 +2277,13 @@ void __bch2_read(struct bch_fs *c, struct bch_read_bio *rbio,
 
 	bch2_bkey_buf_init(&sk);
 	bch2_trans_init(&trans, c, 0, 0);
-retry:
-	bch2_trans_begin(&trans);
 
 	iter = bch2_trans_get_iter(&trans, BTREE_ID_extents,
 				   POS(inode, bvec_iter.bi_sector),
 				   BTREE_ITER_SLOTS);
+retry:
+	bch2_trans_begin(&trans);
+
 	while (1) {
 		unsigned bytes, sectors, offset_into_extent;
 		enum btree_id data_btree = BTREE_ID_extents;
@@ -2339,19 +2339,20 @@ void __bch2_read(struct bch_fs *c, struct bch_read_bio *rbio,
 		swap(bvec_iter.bi_size, bytes);
 		bio_advance_iter(&rbio->bio, &bvec_iter, bytes);
 	}
-	bch2_trans_iter_put(&trans, iter);
 
 	if (ret == -EINTR || ret == READ_RETRY || ret == READ_RETRY_AVOID)
 		goto retry;
 
+	bch2_trans_iter_put(&trans, iter);
+	bch2_trans_exit(&trans);
+	bch2_bkey_buf_exit(&sk, c);
+
 	if (ret) {
 		bch_err_inum_ratelimited(c, inode,
 					 "read error %i from btree lookup", ret);
 		rbio->bio.bi_status = BLK_STS_IOERR;
 		bch2_rbio_done(rbio);
 	}
-	bch2_trans_exit(&trans);
-	bch2_bkey_buf_exit(&sk, c);
 }
 
 void bch2_fs_io_exit(struct bch_fs *c)

fs/bcachefs/move.c

@@ -83,7 +83,7 @@ int bch2_migrate_index_update(struct bch_write_op *op)
 		bool extending = false, should_check_enospc;
 		s64 i_sectors_delta = 0, disk_sectors_delta = 0;
 
-		bch2_trans_reset(&trans, 0);
+		bch2_trans_begin(&trans);
 
 		k = bch2_btree_iter_peek_slot(iter);
 		ret = bkey_err(k);
@@ -597,6 +597,8 @@ static int __bch2_move_data(struct bch_fs *c,
 			}
 		} while (delay);
 
+		bch2_trans_begin(&trans);
+
 		k = bch2_btree_iter_peek(iter);
 
 		stats->pos = iter->pos;
@@ -652,8 +654,7 @@ static int __bch2_move_data(struct bch_fs *c,
 					data_cmd, data_opts);
 		if (ret2) {
 			if (ret2 == -EINTR) {
-				bch2_trans_reset(&trans, 0);
-				bch2_trans_cond_resched(&trans);
+				bch2_trans_begin(&trans);
 				continue;
 			}
 

fs/bcachefs/reflink.c

@@ -305,12 +305,12 @@ s64 bch2_remap_range(struct bch_fs *c,
 	dst_done = dst_iter->pos.offset - dst_start.offset;
 	new_i_size = min(dst_iter->pos.offset << 9, new_i_size);
 
-	bch2_trans_begin(&trans);
-
 	do {
 		struct bch_inode_unpacked inode_u;
 		struct btree_iter *inode_iter;
 
+		bch2_trans_begin(&trans);
+
 		inode_iter = bch2_inode_peek(&trans, &inode_u,
 				dst_start.inode, BTREE_ITER_INTENT);
 		ret2 = PTR_ERR_OR_ZERO(inode_iter);