diff options
| author |   Mike Snitzer <snitzer@redhat.com> | 2016-07-25 21:08:51 -0400 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2016-08-02 16:21:34 -0400 |
| commit | 1814f2e3fb95b58490e56a38fefe462ffe8fb9ad (patch) | |
| tree | bc878dcc44bb1e04a0ceb44bf4bcbcf8d82e98b3 /drivers/md/dm-mpath.c | |
| parent | dm flakey: error READ bios during the down_interval (diff) | |
| download | linux-dev-1814f2e3fb95b58490e56a38fefe462ffe8fb9ad.tar.xz linux-dev-1814f2e3fb95b58490e56a38fefe462ffe8fb9ad.zip | |
dm mpath: add locking to multipath_resume and must_push_back
Multiple flags were being tested without locking. Protect against
non-atomic bit changes in m->flags by holding m->lock (while testing or
setting the queue_if_no_path related flags).
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-mpath.c')
| -rw-r--r-- | drivers/md/dm-mpath.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 7eac080fcb18..d7107d23b897 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -507,13 +507,27 @@ static bool __must_push_back(struct multipath *m) static bool must_push_back_rq(struct multipath *m) { - return (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) || - __must_push_back(m)); + bool r; + unsigned long flags; + + spin_lock_irqsave(&m->lock, flags); + r = (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) || + __must_push_back(m)); + spin_unlock_irqrestore(&m->lock, flags); + + return r; } static bool must_push_back_bio(struct multipath *m) { - return __must_push_back(m); + bool r; + unsigned long flags; + + spin_lock_irqsave(&m->lock, flags); + r = __must_push_back(m); + spin_unlock_irqrestore(&m->lock, flags); + + return r; } /* @@ -1680,12 +1694,14 @@ static void multipath_postsuspend(struct dm_target *ti) static void multipath_resume(struct dm_target *ti) { struct multipath *m = ti->private; + unsigned long flags; + spin_lock_irqsave(&m->lock, flags); if (test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags)) set_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags); else clear_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags); - smp_mb__after_atomic(); + spin_unlock_irqrestore(&m->lock, flags); } /* |