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authorChristoph Hellwig <hch@lst.de>2021-09-29 09:12:39 +0200
committerJens Axboe <axboe@kernel.dk>2021-10-15 21:02:47 -0600
commita6741536f44ae65491cfde6870ae518aabe1ca36 (patch)
tree5cf8803796ba5519add7a1ce416c415dedc16cad /block
parent1f14a0989073459c2be6b5c7b3fb7f9f3d7fa2af (diff)
downloadlinux-a6741536f44ae65491cfde6870ae518aabe1ca36.tar.bz2
block: split bio_queue_enter from blk_queue_enter
To prepare for fixing a gendisk shutdown race, open code the blk_queue_enter logic in bio_queue_enter. This also removes the pointless flags translation. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20210929071241.934472-4-hch@lst.de Tested-by: Yi Zhang <yi.zhang@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-core.c33
1 files changed, 25 insertions, 8 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index 7e9eadacf2de..43f5da707d8e 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -475,18 +475,35 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags)
static inline int bio_queue_enter(struct bio *bio)
{
struct request_queue *q = bio->bi_bdev->bd_disk->queue;
- bool nowait = bio->bi_opf & REQ_NOWAIT;
- int ret;
- ret = blk_queue_enter(q, nowait ? BLK_MQ_REQ_NOWAIT : 0);
- if (unlikely(ret)) {
- if (nowait && !blk_queue_dying(q))
+ while (!blk_try_enter_queue(q, false)) {
+ if (bio->bi_opf & REQ_NOWAIT) {
+ if (blk_queue_dying(q))
+ goto dead;
bio_wouldblock_error(bio);
- else
- bio_io_error(bio);
+ return -EBUSY;
+ }
+
+ /*
+ * read pair of barrier in blk_freeze_queue_start(), we need to
+ * order reading __PERCPU_REF_DEAD flag of .q_usage_counter and
+ * reading .mq_freeze_depth or queue dying flag, otherwise the
+ * following wait may never return if the two reads are
+ * reordered.
+ */
+ smp_rmb();
+ wait_event(q->mq_freeze_wq,
+ (!q->mq_freeze_depth &&
+ blk_pm_resume_queue(false, q)) ||
+ blk_queue_dying(q));
+ if (blk_queue_dying(q))
+ goto dead;
}
- return ret;
+ return 0;
+dead:
+ bio_io_error(bio);
+ return -ENODEV;
}
void blk_queue_exit(struct request_queue *q)