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| author | Guoju Fang <fangguoju@gmail.com> | 2019-11-13 16:03:16 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-10-01 11:11:51 +0200 |
| commit | 20b4b82b02a427b598492de2fcf366d30c9933fc (patch) | |
| tree | d2b1d9eed87ff887f7a57f1423f4b921c206dbd4 /kernel/sys.c | |
| parent | f8e23211976f2ecaf4ab86052ec98b88e2cac5eb (diff) | |
bcache: fix a lost wake-up problem caused by mca_cannibalize_lock
[ Upstream commit 34cf78bf34d48dddddfeeadb44f9841d7864997a ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel/sys.c')
0 files changed, 0 insertions, 0 deletions