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| author | Jens Axboe <axboe@fb.com> | 2016-08-02 08:45:44 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2016-08-04 14:19:16 -0600 |
| commit | c0f3fd2b387448d67ae83c4ce1cc69da375b9186 (patch) | |
| tree | 30fa18a04776d8735fd75d7c7adf9c4eb36d24bf /block/blk-mq-sysfs.c | |
| parent | 6d25ec147e3a71858bed5439c92accd7f739a0a3 (diff) | |
| download | linux-0-day-c0f3fd2b387448d67ae83c4ce1cc69da375b9186.tar.gz linux-0-day-c0f3fd2b387448d67ae83c4ce1cc69da375b9186.tar.xz | |
blk-mq: fix deadlock in blk_mq_register_disk() error path
If we fail registering any of the hardware queues, we call
into blk_mq_unregister_disk() with the hotplug mutex already
held. Since blk_mq_unregister_disk() attempts to acquire the
same mutex, we end up in a less than happy place.
Reported-by: Jinpu Wang <jinpu.wang@profitbricks.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-mq-sysfs.c')
| -rw-r--r-- | block/blk-mq-sysfs.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index 4ea4dd8a1eed5..fe822aa5b8e4a 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -380,15 +380,13 @@ static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx) return ret; } -void blk_mq_unregister_disk(struct gendisk *disk) +static void __blk_mq_unregister_disk(struct gendisk *disk) { struct request_queue *q = disk->queue; struct blk_mq_hw_ctx *hctx; struct blk_mq_ctx *ctx; int i, j; - blk_mq_disable_hotplug(); - queue_for_each_hw_ctx(q, hctx, i) { blk_mq_unregister_hctx(hctx); @@ -405,6 +403,12 @@ void blk_mq_unregister_disk(struct gendisk *disk) kobject_put(&disk_to_dev(disk)->kobj); q->mq_sysfs_init_done = false; +} + +void blk_mq_unregister_disk(struct gendisk *disk) +{ + blk_mq_disable_hotplug(); + __blk_mq_unregister_disk(disk); blk_mq_enable_hotplug(); } @@ -450,7 +454,7 @@ int blk_mq_register_disk(struct gendisk *disk) } if (ret) - blk_mq_unregister_disk(disk); + __blk_mq_unregister_disk(disk); else q->mq_sysfs_init_done = true; out: |