Commit 0abc2a10 authored by Jens Axboe's avatar Jens Axboe
Browse files

block: fix blk_rq_append_bio 



Commit caa4b024(blk-map: call blk_queue_bounce from blk_rq_append_bio)
moves blk_queue_bounce() into blk_rq_append_bio(), but don't consider
the fact that the bounced bio becomes invisible to caller since the
parameter type is 'struct bio *'. Make it a pointer to a pointer to
a bio, so the caller sees the right bio also after a bounce.

Fixes: caa4b024 ("blk-map: call blk_queue_bounce from blk_rq_append_bio")
Cc: Christoph Hellwig <hch@lst.de>
Reported-by: default avatarMichele Ballabio <barra_cuda@katamail.com>
(handling failure of blk_rq_append_bio(), only call bio_get() after
blk_rq_append_bio() returns OK)
Tested-by: default avatarMichele Ballabio <barra_cuda@katamail.com>
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 14cb0dc6

block/blk-map.c

+22 −16
Original line number Diff line number Diff line
@@ -12,22 +12,29 @@ 
#include "blk.h"



/*

 * Append a bio to a passthrough request.  Only works can be merged into

 * the request based on the driver constraints.

 * Append a bio to a passthrough request.  Only works if the bio can be merged

 * into the request based on the driver constraints.

 */

int blk_rq_append_bio(struct request *rq, struct bio *bio)

int blk_rq_append_bio(struct request *rq, struct bio **bio)

{

	blk_queue_bounce(rq->q, &bio);

	struct bio *orig_bio = *bio;



	blk_queue_bounce(rq->q, bio);



	if (!rq->bio) {

		blk_rq_bio_prep(rq->q, rq, bio);

		blk_rq_bio_prep(rq->q, rq, *bio);

	} else {

		if (!ll_back_merge_fn(rq->q, rq, bio))

		if (!ll_back_merge_fn(rq->q, rq, *bio)) {

			if (orig_bio != *bio) {

				bio_put(*bio);

				*bio = orig_bio;

			}

			return -EINVAL;

		}



		rq->biotail->bi_next = bio;

		rq->biotail = bio;

		rq->__data_len += bio->bi_iter.bi_size;

		rq->biotail->bi_next = *bio;

		rq->biotail = *bio;

		rq->__data_len += (*bio)->bi_iter.bi_size;

	}



	return 0;
@@ -73,14 +80,12 @@ static int __blk_rq_map_user_iov(struct request *rq, 
	 * We link the bounce buffer in and could have to traverse it

	 * later so we have to get a ref to prevent it from being freed

	 */

	ret = blk_rq_append_bio(rq, bio);

	bio_get(bio);

	ret = blk_rq_append_bio(rq, &bio);

	if (ret) {

		bio_endio(bio);

		__blk_rq_unmap_user(orig_bio);

		bio_put(bio);

		return ret;

	}

	bio_get(bio);



	return 0;

}
@@ -213,7 +218,7 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf, 
	int reading = rq_data_dir(rq) == READ;

	unsigned long addr = (unsigned long) kbuf;

	int do_copy = 0;

	struct bio *bio;

	struct bio *bio, *orig_bio;

	int ret;



	if (len > (queue_max_hw_sectors(q) << 9))
@@ -236,10 +241,11 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf, 
	if (do_copy)

		rq->rq_flags |= RQF_COPY_USER;



	ret = blk_rq_append_bio(rq, bio);

	orig_bio = bio;

	ret = blk_rq_append_bio(rq, &bio);

	if (unlikely(ret)) {

		/* request is too big */

		bio_put(bio);

		bio_put(orig_bio);

		return ret;

	}

drivers/scsi/osd/osd_initiator.c

+3 −1
Original line number Diff line number Diff line
@@ -1576,7 +1576,9 @@ static struct request *_make_request(struct request_queue *q, bool has_write, 
		return req;



	for_each_bio(bio) {

		ret = blk_rq_append_bio(req, bio);

		struct bio *bounce_bio = bio;



		ret = blk_rq_append_bio(req, &bounce_bio);

		if (ret)

			return ERR_PTR(ret);

	}

drivers/target/target_core_pscsi.c

+2 −2
Original line number Diff line number Diff line
@@ -920,7 +920,7 @@ pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, 
					" %d i: %d bio: %p, allocating another"

					" bio\n", bio->bi_vcnt, i, bio);



				rc = blk_rq_append_bio(req, bio);

				rc = blk_rq_append_bio(req, &bio);

				if (rc) {

					pr_err("pSCSI: failed to append bio\n");

					goto fail;
@@ -938,7 +938,7 @@ pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, 
	}



	if (bio) {

		rc = blk_rq_append_bio(req, bio);

		rc = blk_rq_append_bio(req, &bio);

		if (rc) {

			pr_err("pSCSI: failed to append bio\n");

			goto fail;

include/linux/blkdev.h

+1 −1
Original line number Diff line number Diff line
@@ -965,7 +965,7 @@ extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src, 
extern void blk_rq_unprep_clone(struct request *rq);

extern blk_status_t blk_insert_cloned_request(struct request_queue *q,

				     struct request *rq);

extern int blk_rq_append_bio(struct request *rq, struct bio *bio);

extern int blk_rq_append_bio(struct request *rq, struct bio **bio);

extern void blk_delay_queue(struct request_queue *, unsigned long);

extern void blk_queue_split(struct request_queue *, struct bio **);

extern void blk_recount_segments(struct request_queue *, struct bio *);

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