diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2012-03-02 10:51:00 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-03-19 08:57:59 -0700 |
| commit | 25705e3a3e9f91280b51124a28e74418aff00c7d (patch) | |
| tree | 4ae031ef034ef5fba5866821e08204a3826644d6 /block | |
| parent | aaa136d348dc723f45667aa8b39eb58c7e7c4383 (diff) | |
Block: use a freezable workqueue for disk-event polling
commit 62d3c5439c534b0e6c653fc63e6d8c67be3a57b1 upstream.
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>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'block')
| -rw-r--r-- | block/genhd.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/block/genhd.c b/block/genhd.c index 091429d2c7c9..f6ecddb79952 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1487,9 +1487,9 @@ static void __disk_unblock_events(struct gendisk *disk, bool check_now) intv = disk_events_poll_jiffies(disk); set_timer_slack(&ev->dwork.timer, intv / 4); if (check_now) - queue_delayed_work(system_nrt_wq, &ev->dwork, 0); + queue_delayed_work(system_nrt_freezable_wq, &ev->dwork, 0); else if (intv) - queue_delayed_work(system_nrt_wq, &ev->dwork, intv); + queue_delayed_work(system_nrt_freezable_wq, &ev->dwork, intv); out_unlock: spin_unlock_irqrestore(&ev->lock, flags); } @@ -1530,7 +1530,7 @@ void disk_check_events(struct gendisk *disk) spin_lock_irqsave(&ev->lock, flags); if (!ev->block) { cancel_delayed_work(&ev->dwork); - queue_delayed_work(system_nrt_wq, &ev->dwork, 0); + queue_delayed_work(system_nrt_freezable_wq, &ev->dwork, 0); } spin_unlock_irqrestore(&ev->lock, flags); } @@ -1568,7 +1568,7 @@ unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask) /* uncondtionally schedule event check and wait for it to finish */ disk_block_events(disk); - queue_delayed_work(system_nrt_wq, &ev->dwork, 0); + queue_delayed_work(system_nrt_freezable_wq, &ev->dwork, 0); flush_delayed_work(&ev->dwork); __disk_unblock_events(disk, false); @@ -1605,7 +1605,7 @@ static void disk_events_workfn(struct work_struct *work) intv = disk_events_poll_jiffies(disk); if (!ev->block && intv) - queue_delayed_work(system_nrt_wq, &ev->dwork, intv); + queue_delayed_work(system_nrt_freezable_wq, &ev->dwork, intv); spin_unlock_irq(&ev->lock); |