path: root/include
diff options
authorAlan Stern <stern@rowland.harvard.edu>2012-03-02 10:51:00 +0100
committerJens Axboe <axboe@kernel.dk>2012-03-02 10:51:00 +0100
commit62d3c5439c534b0e6c653fc63e6d8c67be3a57b1 (patch)
treed335d0e449ef2d61d52921e3f210cdd403bb025a /include
parentcecd353a02fb1405c8a72a324b26b5acf97e7411 (diff)
Block: use a freezable workqueue for disk-event polling
This patch (as1519) fixes a bug in the block layer's disk-events polling. The polling is done by a work routine queued on the system_nrt_wq workqueue. Since that workqueue isn't freezable, the polling continues even in the middle of a system sleep transition. Obviously, polling a suspended drive for media changes and such isn't a good thing to do; in the case of USB mass-storage devices it can lead to real problems requiring device resets and even re-enumeration. The patch fixes things by creating a new system-wide, non-reentrant, freezable workqueue and using it for disk-events polling. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: <stable@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include')
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index eb8b9f15f2e0..af155450cabb 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -289,12 +289,16 @@ enum {
* system_freezable_wq is equivalent to system_wq except that it's
* freezable.
+ *
+ * system_nrt_freezable_wq is equivalent to system_nrt_wq except that
+ * it's freezable.
extern struct workqueue_struct *system_wq;
extern struct workqueue_struct *system_long_wq;
extern struct workqueue_struct *system_nrt_wq;
extern struct workqueue_struct *system_unbound_wq;
extern struct workqueue_struct *system_freezable_wq;
+extern struct workqueue_struct *system_nrt_freezable_wq;
extern struct workqueue_struct *
__alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active,