diff options
| author | Guoju Fang <fangguoju@gmail.com> | 2019-11-13 16:03:16 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-11-13 15:42:50 -0700 |
| commit | 34cf78bf34d48dddddfeeadb44f9841d7864997a (patch) | |
| tree | d6010b3ea9defa5300f679f4fe8bd55d85ebd2bd /drivers/md/bcache/bcache.h | |
| parent | c0e0954e909c17b43d176ab219fc598964616ae6 (diff) | |
bcache: fix a lost wake-up problem caused by mca_cannibalize_lock
This patch fix a lost wake-up problem caused by the race between
mca_cannibalize_lock and bch_cannibalize_unlock.
Consider two processes, A and B. Process A is executing
mca_cannibalize_lock, while process B takes c->btree_cache_alloc_lock
and is executing bch_cannibalize_unlock. The problem happens that after
process A executes cmpxchg and will execute prepare_to_wait. In this
timeslice process B executes wake_up, but after that process A executes
prepare_to_wait and set the state to TASK_INTERRUPTIBLE. Then process A
goes to sleep but no one will wake up it. This problem may cause bcache
device to dead.
Signed-off-by: Guoju Fang <fangguoju@gmail.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 | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h index 013e35a9e317..3653faf3bf48 100644 --- a/drivers/md/bcache/bcache.h +++ b/drivers/md/bcache/bcache.h @@ -582,6 +582,7 @@ struct cache_set { */ wait_queue_head_t btree_cache_wait; struct task_struct *btree_cache_alloc_lock; + spinlock_t btree_cannibalize_lock; /* * When we free a btree node, we increment the gen of the bucket the |