diff options
| author |   Ming Lei <ming.lei@redhat.com> | 2019-01-15 11:59:52 +0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2019-01-15 16:29:57 +1200 |
| commit | fe76fc6aaf538df27708ffa3e5d549a6c8e16142 (patch) | |
| tree | 4fda8ebbcb82694899a476026684951e25d9b853 /lib/sbitmap.c | |
| parent | sbitmap: Protect swap_lock from softirqs (diff) | |
| download | linux-dev-fe76fc6aaf538df27708ffa3e5d549a6c8e16142.tar.xz linux-dev-fe76fc6aaf538df27708ffa3e5d549a6c8e16142.zip | |
sbitmap: Protect swap_lock from hardirq
Because we may call blk_mq_get_driver_tag() directly from
blk_mq_dispatch_rq_list() without holding any lock, then HARDIRQ may
come and the above DEADLOCK is triggered.
Commit ab53dcfb3e7b ("sbitmap: Protect swap_lock from hardirq") tries to
fix this issue by using 'spin_lock_bh', which isn't enough because we
complete request from hardirq context direclty in case of multiqueue.
Cc: Clark Williams <williams@redhat.com>
Fixes: ab53dcfb3e7b ("sbitmap: Protect swap_lock from hardirq")
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/sbitmap.c')
| -rw-r--r-- | lib/sbitmap.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/lib/sbitmap.c b/lib/sbitmap.c index 864354000e04..5b382c1244ed 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -27,8 +27,9 @@ static inline bool sbitmap_deferred_clear(struct sbitmap *sb, int index) { unsigned long mask, val; bool ret = false; + unsigned long flags; - spin_lock_bh(&sb->map[index].swap_lock); + spin_lock_irqsave(&sb->map[index].swap_lock, flags); if (!sb->map[index].cleared) goto out_unlock; @@ -49,7 +50,7 @@ static inline bool sbitmap_deferred_clear(struct sbitmap *sb, int index) ret = true; out_unlock: - spin_unlock_bh(&sb->map[index].swap_lock); + spin_unlock_irqrestore(&sb->map[index].swap_lock, flags); return ret; } |