From 0a87b25ff2eb6169403c88b0d5f3c97bdaa3c930 Mon Sep 17 00:00:00 2001 From: "Ahmed S. Darwish" Date: Mon, 20 Jul 2020 17:55:25 +0200 Subject: raid5: Use sequence counter with associated spinlock A sequence counter write side critical section must be protected by some form of locking to serialize writers. A plain seqcount_t does not contain the information of which lock must be held when entering a write side critical section. Use the new seqcount_spinlock_t data type, which allows to associate a spinlock with the sequence counter. This enables lockdep to verify that the spinlock used for writer serialization is held when the write side critical section is entered. If lockdep is disabled this lock association is compiled out and has neither storage size nor runtime overhead. Signed-off-by: Ahmed S. Darwish Signed-off-by: Peter Zijlstra (Intel) Acked-by: Song Liu Link: https://lkml.kernel.org/r/20200720155530.1173732-20-a.darwish@linutronix.de --- drivers/md/raid5.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/md/raid5.h') diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index f90e0704bed9..a2c9e9e9f5ac 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -589,7 +589,7 @@ struct r5conf { int prev_chunk_sectors; int prev_algo; short generation; /* increments with every reshape */ - seqcount_t gen_lock; /* lock against generation changes */ + seqcount_spinlock_t gen_lock; /* lock against generation changes */ unsigned long reshape_checkpoint; /* Time we last updated * metadata */ long long min_offset_diff; /* minimum difference between -- cgit v1.2.3-58-ga151