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authorJens Axboe <axboe@kernel.dk>2017-12-18 15:40:44 +0800
committerJens Axboe <axboe@kernel.dk>2017-12-18 13:55:43 -0700
commit0abc2a10389f0c9070f76ca906c7382788036b93 (patch)
tree9d1f1b48a3acbff7ed8b1549ebb1cffe3b407b81 /block
parent14cb0dc6479dc5ebc63b3a459a5d89a2f1b39fed (diff)
downloadlinux-0abc2a10389f0c9070f76ca906c7382788036b93.tar.bz2
block: fix blk_rq_append_bio
Commit caa4b02476e3(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: caa4b02476e3 ("blk-map: call blk_queue_bounce from blk_rq_append_bio") Cc: Christoph Hellwig <hch@lst.de> Reported-by: Michele 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: Michele Ballabio <barra_cuda@katamail.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-map.c38
1 files changed, 22 insertions, 16 deletions
diff --git a/block/blk-map.c b/block/blk-map.c
index b21f8e86f120..d3a94719f03f 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -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;
}