linux

iv/linux

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Guoju Fang fa12d56b8d 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>

2020-10-01 20:40:03 +02:00

alloc.c

bcache: avoid clang -Wunintialized warning

2019-05-31 06:48:16 -07:00

bcache.h

bcache: fix a lost wake-up problem caused by mca_cannibalize_lock

2020-10-01 20:40:03 +02:00

bset.c

bcache: allocate meta data pages as compound pages

2020-08-21 11:02:08 +02:00

bset.h

bcache: explicity type cast in bset_bkey_last()