diff options
| author |   Dennis Zhou <dennis@kernel.org> | 2018-10-20 14:56:12 -0400 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2018-10-20 15:39:55 -0600 |
| commit | d459d853c2edc793135e4bfa4e345c758f1cc859 (patch) | |
| tree | bef29425e5ddb78a788cca764e926b4f5601f473 /block/bio.c | |
| parent | blkcg: fix edge case for blk_get_rl() under memory pressure (diff) | |
| download | linux-dev-d459d853c2edc793135e4bfa4e345c758f1cc859.tar.xz linux-dev-d459d853c2edc793135e4bfa4e345c758f1cc859.zip | |
blkcg: reassociate bios when make_request() is called recursively
When submitting a bio, multiple recursive calls to make_request() may
occur. This causes the initial associate done in blkcg_bio_issue_check()
to be incorrect and reference the prior request_queue. This introduces
a helper to do reassociation when make_request() is recursively called.
Fixes: a7b39b4e961c ("blkcg: always associate a bio with a blkg")
Reported-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/bio.c')
| -rw-r--r-- | block/bio.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/block/bio.c b/block/bio.c index 17a8b0aa7050..bbfeb4ee2892 100644 --- a/block/bio.c +++ b/block/bio.c @@ -2084,6 +2084,26 @@ int bio_associate_create_blkg(struct request_queue *q, struct bio *bio) } /** + * bio_reassociate_blkg - reassociate a bio with a blkg from q + * @q: request_queue where bio is going + * @bio: target bio + * + * When submitting a bio, multiple recursive calls to make_request() may occur. + * This causes the initial associate done in blkcg_bio_issue_check() to be + * incorrect and reference the prior request_queue. This performs reassociation + * when this situation happens. + */ +int bio_reassociate_blkg(struct request_queue *q, struct bio *bio) +{ + if (bio->bi_blkg) { + blkg_put(bio->bi_blkg); + bio->bi_blkg = NULL; + } + + return bio_associate_create_blkg(q, bio); +} + +/** * bio_disassociate_task - undo bio_associate_current() * @bio: target bio */ |