block: loop: fix problems for backward compatibility with Linux 4.19.y

The changes replace macros or symbols that are only available first in
Linux kernel 4.20.y or later.

Signed-off-by: Manuel Bentele <development@manuel-bentele.de>

2 files changed, 14 insertions, 33 deletions

diff --git a/drivers/block/loop/loop_file_fmt_qcow_main.c b/drivers/block/loop/loop_file_fmt_qcow_main.c
index 4a1fb5bf346d..d3e456f80803 100644
--- a/drivers/block/loop/loop_file_fmt_qcow_main.c
+++ b/drivers/block/loop/loop_file_fmt_qcow_main.c
@@ -133,16 +133,6 @@ static inline loff_t __qcow_file_fmt_rq_get_pos(struct loop_file_fmt *lo_fmt,
 	return ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset;
 }
 
-static inline void __qcow_file_fmt_iov_iter_bvec(struct iov_iter *i,
-						 unsigned int direction,
-						 const struct bio_vec *bvec,
-						 unsigned long nr_segs,
-						 size_t count)
-{
-	iov_iter_bvec(i, direction, bvec, nr_segs, count);
-	i->type |= ITER_BVEC_FLAG_NO_REF;
-}
-
 static int __qcow_file_fmt_compression_init(struct loop_file_fmt *lo_fmt)
 {
 	struct loop_file_fmt_qcow_data *qcow_data = lo_fmt->private_data;
diff --git a/drivers/block/loop/loop_file_fmt_raw.c b/drivers/block/loop/loop_file_fmt_raw.c
index d3c8743de5d2..1920dcf675fd 100644
--- a/drivers/block/loop/loop_file_fmt_raw.c
+++ b/drivers/block/loop/loop_file_fmt_raw.c
@@ -29,16 +29,6 @@ static inline loff_t __raw_file_fmt_rq_get_pos(struct loop_file_fmt *lo_fmt,
 	return ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset;
 }
 
-static inline void __raw_file_fmt_iov_iter_bvec(struct iov_iter *i,
-						unsigned int direction,
-						const struct bio_vec *bvec,
-						unsigned long nr_segs,
-						size_t count)
-{
-	iov_iter_bvec(i, direction, bvec, nr_segs, count);
-	i->type |= ITER_BVEC_FLAG_NO_REF;
-}
-
 /* transfer function for DEPRECATED cryptoloop support */
 static inline int __raw_file_fmt_do_transfer(struct loop_file_fmt *lo_fmt,
 					     int cmd,
@@ -88,7 +78,7 @@ static int raw_file_fmt_read_transfer(struct loop_file_fmt *lo_fmt,
 		b.bv_offset = 0;
 		b.bv_len = bvec.bv_len;
 
-		__raw_file_fmt_iov_iter_bvec(&i, READ, &b, 1, b.bv_len);
+		iov_iter_bvec(&i, ITER_BVEC, &b, 1, b.bv_len);
 		len = vfs_iter_read(lo->lo_backing_file, &i, &pos, 0);
 		if (len < 0) {
 			ret = len;
@@ -135,7 +125,7 @@ static int raw_file_fmt_read(struct loop_file_fmt *lo_fmt,
 	pos = __raw_file_fmt_rq_get_pos(lo_fmt, rq);
 
 	rq_for_each_segment(bvec, rq, iter) {
-		__raw_file_fmt_iov_iter_bvec(&i, READ, &bvec, 1, bvec.bv_len);
+		iov_iter_bvec(&i, ITER_BVEC, &bvec, 1, bvec.bv_len);
 		len = vfs_iter_read(lo->lo_backing_file, &i, &pos, 0);
 		if (len < 0)
 			return len;
@@ -181,15 +171,13 @@ static int __raw_file_fmt_rw_aio(struct loop_file_fmt *lo_fmt,
 				 bool rw)
 {
 	struct iov_iter iter;
-	struct req_iterator rq_iter;
 	struct bio_vec *bvec;
 	struct bio *bio = rq->bio;
 	struct file *file;
-	struct bio_vec tmp;
 	struct loop_device *lo;
 	struct loop_cmd *cmd;
 	unsigned int offset;
-	int nr_bvec = 0;
+	int segments = 0;
 	int ret;
 	loff_t pos;
 
@@ -198,12 +186,13 @@ static int __raw_file_fmt_rw_aio(struct loop_file_fmt *lo_fmt,
 	cmd = blk_mq_rq_to_pdu(rq);
 	pos = __raw_file_fmt_rq_get_pos(lo_fmt, rq);
 
-	rq_for_each_bvec(tmp, rq, rq_iter)
-		nr_bvec++;
-
 	if (rq->bio != rq->biotail) {
+		struct req_iterator iter;
+		struct bio_vec tmp;
 
-		bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec),
+		__rq_for_each_bio(bio, rq)
+			segments += bio_segments(bio);
+		bvec = kmalloc_array(segments, sizeof(struct bio_vec),
 				     GFP_NOIO);
 		if (!bvec)
 			return -EIO;
@@ -212,10 +201,10 @@ static int __raw_file_fmt_rw_aio(struct loop_file_fmt *lo_fmt,
 		/*
 		 * The bios of the request may be started from the middle of
 		 * the 'bvec' because of bio splitting, so we can't directly
-		 * copy bio->bi_iov_vec to new bvec. The rq_for_each_bvec
+		 * copy bio->bi_iov_vec to new bvec. The rq_for_each_segment
 		 * API will take care of all details for us.
 		 */
-		rq_for_each_bvec(tmp, rq, rq_iter) {
+		rq_for_each_segment(tmp, rq, iter) {
 			*bvec = tmp;
 			bvec++;
 		}
@@ -229,10 +218,12 @@ static int __raw_file_fmt_rw_aio(struct loop_file_fmt *lo_fmt,
 		 */
 		offset = bio->bi_iter.bi_bvec_done;
 		bvec = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter);
+		segments = bio_segments(bio);
 	}
 	atomic_set(&cmd->ref, 2);
 
-	__raw_file_fmt_iov_iter_bvec(&iter, rw, bvec, nr_bvec, blk_rq_bytes(rq));
+	iov_iter_bvec(&iter, ITER_BVEC | rw, bvec, 
+		      segments, blk_rq_bytes(rq));
 	iter.iov_offset = offset;
 
 	cmd->iocb.ki_pos = pos;
@@ -269,7 +260,7 @@ static int __raw_file_fmt_write_bvec(struct file *file,
 	struct iov_iter i;
 	ssize_t bw;
 
-	__raw_file_fmt_iov_iter_bvec(&i, WRITE, bvec, 1, bvec->bv_len);
+	iov_iter_bvec(&i, ITER_BVEC | WRITE, bvec, 1, bvec->bv_len);
 
 	file_start_write(file);
 	bw = vfs_iter_write(file, &i, ppos, 0);