diff options
| author |   Andrea Righi <andrea.righi@canonical.com> | 2019-11-13 16:03:21 +0800 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2019-11-13 15:42:50 -0700 |
| commit | 84c529aea182939e68f618ed9813740c9165c7eb (patch) | |
| tree | c78c0dac4b48524af17fae7db7ec90cdcad5645c /drivers/md/bcache/bcache.h | |
| parent | bcache: add code comment bch_keylist_pop() and bch_keylist_pop_front() (diff) | |
| download | linux-dev-84c529aea182939e68f618ed9813740c9165c7eb.tar.xz linux-dev-84c529aea182939e68f618ed9813740c9165c7eb.zip | |
bcache: fix deadlock in bcache_allocator
bcache_allocator can call the following:
bch_allocator_thread()
-> bch_prio_write()
-> bch_bucket_alloc()
-> wait on &ca->set->bucket_wait
But the wake up event on bucket_wait is supposed to come from
bch_allocator_thread() itself => deadlock:
[ 1158.490744] INFO: task bcache_allocato:15861 blocked for more than 10 seconds.
[ 1158.495929] Not tainted 5.3.0-050300rc3-generic #201908042232
[ 1158.500653] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1158.504413] bcache_allocato D 0 15861 2 0x80004000
[ 1158.504419] Call Trace:
[ 1158.504429] __schedule+0x2a8/0x670
[ 1158.504432] schedule+0x2d/0x90
[ 1158.504448] bch_bucket_alloc+0xe5/0x370 [bcache]
[ 1158.504453] ? wait_woken+0x80/0x80
[ 1158.504466] bch_prio_write+0x1dc/0x390 [bcache]
[ 1158.504476] bch_allocator_thread+0x233/0x490 [bcache]
[ 1158.504491] kthread+0x121/0x140
[ 1158.504503] ? invalidate_buckets+0x890/0x890 [bcache]
[ 1158.504506] ? kthread_park+0xb0/0xb0
[ 1158.504510] ret_from_fork+0x35/0x40
Fix by making the call to bch_prio_write() non-blocking, so that
bch_allocator_thread() never waits on itself.
Moreover, make sure to wake up the garbage collector thread when
bch_prio_write() is failing to allocate buckets.
BugLink: https://bugs.launchpad.net/bugs/1784665
BugLink: https://bugs.launchpad.net/bugs/1796292
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/md/bcache/bcache.h')
| -rw-r--r-- | drivers/md/bcache/bcache.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h index 3653faf3bf48..50241e045c70 100644 --- a/drivers/md/bcache/bcache.h +++ b/drivers/md/bcache/bcache.h @@ -978,7 +978,7 @@ bool bch_cached_dev_error(struct cached_dev *dc); __printf(2, 3) bool bch_cache_set_error(struct cache_set *c, const char *fmt, ...); -void bch_prio_write(struct cache *ca); +int bch_prio_write(struct cache *ca, bool wait); void bch_write_bdev_super(struct cached_dev *dc, struct closure *parent); extern struct workqueue_struct *bcache_wq; |