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| author | Tejun Heo <tj@kernel.org> | 2014-09-24 13:00:21 -0400 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2014-09-24 13:00:21 -0400 |
| commit | d06efebf0c37d438fcf07057be00dd40fcfce08d (patch) | |
| tree | 31a0786d132aadf4cbb9725f3f444ef6e1052128 /lib/percpu-refcount.c | |
| parent | bb2e226b3bef596dd56be97df655d857b4603923 (diff) | |
| parent | 0a30288da1aec914e158c2d7a3482a85f632750f (diff) | |
| download | lwn-d06efebf0c37d438fcf07057be00dd40fcfce08d.tar.gz lwn-d06efebf0c37d438fcf07057be00dd40fcfce08d.zip | |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block into for-3.18
This is to receive 0a30288da1ae ("blk-mq, percpu_ref: implement a
kludge for SCSI blk-mq stall during probe") which implements
__percpu_ref_kill_expedited() to work around SCSI blk-mq stall. The
commit reverted and patches to implement proper fix will be added.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'lib/percpu-refcount.c')
| -rw-r--r-- | lib/percpu-refcount.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c index 559ee0b20318..c6c31e2829b1 100644 --- a/lib/percpu-refcount.c +++ b/lib/percpu-refcount.c @@ -189,3 +189,19 @@ void percpu_ref_kill_and_confirm(struct percpu_ref *ref, call_rcu_sched(&ref->rcu, percpu_ref_kill_rcu); } EXPORT_SYMBOL_GPL(percpu_ref_kill_and_confirm); + +/* + * XXX: Temporary kludge to work around SCSI blk-mq stall. Used only by + * block/blk-mq.c::blk_mq_freeze_queue(). Will be removed during v3.18 + * devel cycle. Do not use anywhere else. + */ +void __percpu_ref_kill_expedited(struct percpu_ref *ref) +{ + WARN_ONCE(ref->pcpu_count_ptr & PCPU_REF_DEAD, + "percpu_ref_kill() called more than once on %pf!", + ref->release); + + ref->pcpu_count_ptr |= PCPU_REF_DEAD; + synchronize_sched_expedited(); + percpu_ref_kill_rcu(&ref->rcu); +} |