diff options
| author | Christoph Hellwig <hch@lst.de> | 2022-03-30 08:29:17 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-04-18 15:54:10 +0300 |
| commit | d292dc80686aeafc418d809b4f9598578a7f294f (patch) | |
| tree | 7dd4a6f78e7f19aadc633d080df68f2069526d96 /drivers/block | |
| parent | a0e286b6a5b61d4da01bdf865071c4da417046d6 (diff) | |
| download | linux-d292dc80686aeafc418d809b4f9598578a7f294f.tar.xz | |
loop: don't destroy lo->workqueue in __loop_clr_fd
There is no need to destroy the workqueue when clearing unbinding
a loop device from a backing file. Not doing so on the other hand
avoid creating a complex lock dependency chain involving the global
system_transition_mutex.
Based on a patch from Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>.
Reported-by: syzbot+6479585dfd4dedd3f7e1@syzkaller.appspotmail.com
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Tested-by: syzbot+6479585dfd4dedd3f7e1@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20220330052917.2566582-16-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/loop.c | 26 |
1 files changed, 13 insertions, 13 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 204558d7a81d..0c7f0367200c 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -812,7 +812,6 @@ struct loop_worker { }; static void loop_workfn(struct work_struct *work); -static void loop_rootcg_workfn(struct work_struct *work); #ifdef CONFIG_BLK_CGROUP static inline int queue_on_root_worker(struct cgroup_subsys_state *css) @@ -1050,20 +1049,19 @@ static int loop_configure(struct loop_device *lo, fmode_t mode, !file->f_op->write_iter) lo->lo_flags |= LO_FLAGS_READ_ONLY; - lo->workqueue = alloc_workqueue("loop%d", - WQ_UNBOUND | WQ_FREEZABLE, - 0, - lo->lo_number); if (!lo->workqueue) { - error = -ENOMEM; - goto out_unlock; + lo->workqueue = alloc_workqueue("loop%d", + WQ_UNBOUND | WQ_FREEZABLE, + 0, lo->lo_number); + if (!lo->workqueue) { + error = -ENOMEM; + goto out_unlock; + } } disk_force_media_change(lo->lo_disk, DISK_EVENT_MEDIA_CHANGE); set_disk_ro(lo->lo_disk, (lo->lo_flags & LO_FLAGS_READ_ONLY) != 0); - INIT_WORK(&lo->rootcg_work, loop_rootcg_workfn); - INIT_LIST_HEAD(&lo->rootcg_cmd_list); lo->use_dio = lo->lo_flags & LO_FLAGS_DIRECT_IO; lo->lo_device = bdev; lo->lo_backing_file = file; @@ -1143,10 +1141,6 @@ static void __loop_clr_fd(struct loop_device *lo, bool release) if (!release) blk_mq_freeze_queue(lo->lo_queue); - destroy_workqueue(lo->workqueue); - loop_free_idle_workers(lo, true); - del_timer_sync(&lo->timer); - spin_lock_irq(&lo->lo_lock); filp = lo->lo_backing_file; lo->lo_backing_file = NULL; @@ -1750,6 +1744,10 @@ static void lo_free_disk(struct gendisk *disk) { struct loop_device *lo = disk->private_data; + if (lo->workqueue) + destroy_workqueue(lo->workqueue); + loop_free_idle_workers(lo, true); + del_timer_sync(&lo->timer); mutex_destroy(&lo->lo_mutex); kfree(lo); } @@ -2013,6 +2011,8 @@ static int loop_add(int i) lo->lo_number = i; spin_lock_init(&lo->lo_lock); spin_lock_init(&lo->lo_work_lock); + INIT_WORK(&lo->rootcg_work, loop_rootcg_workfn); + INIT_LIST_HEAD(&lo->rootcg_cmd_list); disk->major = LOOP_MAJOR; disk->first_minor = i << part_shift; disk->minors = 1 << part_shift; |