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authorColy Li <colyli@suse.de>2018-08-11 08:20:00 +0300
committerJens Axboe <axboe@kernel.dk>2018-08-12 00:46:42 +0300
commiteb2b3d034511f7f5f5fa781b9354ea4d5dbd4fc5 (patch)
treead0d16a069090d085913618d74c928ef828417bc
parentd0c1b89a409fb8f55783e95effeb60d703f81061 (diff)
downloadlinux-eb2b3d034511f7f5f5fa781b9354ea4d5dbd4fc5.tar.xz
bcache: add the missing comments for smp_mb()/smp_wmb()
Checkpatch.pl warns there are 2 locations of smp_mb() and smp_wmb() without code comment. This patch adds the missing code comments for these memory barrier calls. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--drivers/md/bcache/closure.h4
-rw-r--r--drivers/md/bcache/super.c2
2 files changed, 4 insertions, 2 deletions
diff --git a/drivers/md/bcache/closure.h b/drivers/md/bcache/closure.h
index 7f3594c0be14..eca0d496b686 100644
--- a/drivers/md/bcache/closure.h
+++ b/drivers/md/bcache/closure.h
@@ -289,10 +289,12 @@ static inline void closure_init_stack(struct closure *cl)
}
/**
- * closure_wake_up - wake up all closures on a wait list.
+ * closure_wake_up - wake up all closures on a wait list,
+ * with memory barrier
*/
static inline void closure_wake_up(struct closure_waitlist *list)
{
+ /* Memory barrier for the wait list */
smp_mb();
__closure_wake_up(list);
}
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index e637d74e2908..94c756c66bd7 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1136,11 +1136,11 @@ int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c,
list_move(&dc->list, &c->cached_devs);
calc_cached_dev_sectors(c);
- smp_wmb();
/*
* dc->c must be set before dc->count != 0 - paired with the mb in
* cached_dev_get()
*/
+ smp_wmb();
refcount_set(&dc->count, 1);
/* Block writeback thread, but spawn it */