On 2019/11/17 11:32 上午, Eric Wheeler wrote: > On Wed, 13 Nov 2019, Coly Li wrote: > >> From: Guoju Fang <fangguoju@xxxxxxxxx> >> >> 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@xxxxxxxxx> >> Signed-off-by: Coly Li <colyli@xxxxxxx> > > Add cc stable? > Yes, I agree. Now these patches are applied by Jens, how about explicitly send these patches to linux-stable after they go upstream ? Thanks. Coly Li > -Eric > > >> --- >> drivers/md/bcache/bcache.h | 1 + >> drivers/md/bcache/btree.c | 12 ++++++++---- >> drivers/md/bcache/super.c | 1 + >> 3 files changed, 10 insertions(+), 4 deletions(-) >> [snip] -- Coly Li
