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

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
......@@ -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;
}
......
......@@ -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);
}
......
......@@ -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;
......
......@@ -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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