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| author | Andrea Righi <andrea.righi@canonical.com> | 2019-11-13 11:03:21 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-12-31 18:45:30 +0300 |
| commit | 47a417e7cf63ecc8f6b9e851bd49e9cd295285d2 (patch) | |
| tree | dcf95e805eb0060ac55a16c4a72eb73a58f3abee /drivers/md/bcache/bcache.h | |
| parent | 4ff039ca442d1df960ff8894275af1df96bb800a (diff) | |
| download | linux-47a417e7cf63ecc8f6b9e851bd49e9cd295285d2.tar.xz | |
bcache: fix deadlock in bcache_allocator
[ Upstream commit 84c529aea182939e68f618ed9813740c9165c7eb ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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 013e35a9e317..deb924e1d790 100644 --- a/drivers/md/bcache/bcache.h +++ b/drivers/md/bcache/bcache.h @@ -977,7 +977,7 @@ 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; |