| Message ID | 20181116081006.5083-6-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/6] block: remove the rq_alloc_data request_queue field | expand |
On Fri, Nov 16, 2018 at 09:10:05AM +0100, Christoph Hellwig wrote: > blk_mq_stop_hw_queues doesn't need any locking, and the ide > dev_flags field isn't protected by it either. Is it a bug that dev_flags is no longer protected by queue_lock after the mq conversion? > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > drivers/ide/ide-pm.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/drivers/ide/ide-pm.c b/drivers/ide/ide-pm.c > index 56690f523100..192e6c65d34e 100644 > --- a/drivers/ide/ide-pm.c > +++ b/drivers/ide/ide-pm.c > @@ -201,7 +201,6 @@ void ide_complete_pm_rq(ide_drive_t *drive, struct request *rq) > { > struct request_queue *q = drive->queue; > struct ide_pm_state *pm = ide_req(rq)->special; > - unsigned long flags; > > ide_complete_power_step(drive, rq); > if (pm->pm_step != IDE_PM_COMPLETED) > @@ -211,12 +210,10 @@ void ide_complete_pm_rq(ide_drive_t *drive, struct request *rq) > printk("%s: completing PM request, %s\n", drive->name, > (ide_req(rq)->type == ATA_PRIV_PM_SUSPEND) ? "suspend" : "resume"); > #endif > - spin_lock_irqsave(&q->queue_lock, flags); > if (ide_req(rq)->type == ATA_PRIV_PM_SUSPEND) > blk_mq_stop_hw_queues(q); > else > drive->dev_flags &= ~IDE_DFLAG_BLOCKED; > - spin_unlock_irqrestore(&q->queue_lock, flags); > > drive->hwif->rq = NULL; > > -- > 2.19.1 >
On Fri, Nov 16, 2018 at 12:37:32AM -0800, Omar Sandoval wrote: > On Fri, Nov 16, 2018 at 09:10:05AM +0100, Christoph Hellwig wrote: > > blk_mq_stop_hw_queues doesn't need any locking, and the ide > > dev_flags field isn't protected by it either. > > Is it a bug that dev_flags is no longer protected by queue_lock after > the mq conversion? Most if not all users weren't under queue_lock before. As far as I can tell it generally is set in the probe path, and without any obvious locking.
On Fri, Nov 16, 2018 at 09:40:04AM +0100, Christoph Hellwig wrote: > On Fri, Nov 16, 2018 at 12:37:32AM -0800, Omar Sandoval wrote: > > On Fri, Nov 16, 2018 at 09:10:05AM +0100, Christoph Hellwig wrote: > > > blk_mq_stop_hw_queues doesn't need any locking, and the ide > > > dev_flags field isn't protected by it either. > > > > Is it a bug that dev_flags is no longer protected by queue_lock after > > the mq conversion? > > Most if not all users weren't under queue_lock before. As far as I can > tell it generally is set in the probe path, and without any obvious > locking. Good enough for me, you can add Reviewed-by: Omar Sandoval <osandov@fb.com>
diff --git a/drivers/ide/ide-pm.c b/drivers/ide/ide-pm.c index 56690f523100..192e6c65d34e 100644 --- a/drivers/ide/ide-pm.c +++ b/drivers/ide/ide-pm.c @@ -201,7 +201,6 @@ void ide_complete_pm_rq(ide_drive_t *drive, struct request *rq) { struct request_queue *q = drive->queue; struct ide_pm_state *pm = ide_req(rq)->special; - unsigned long flags; ide_complete_power_step(drive, rq); if (pm->pm_step != IDE_PM_COMPLETED) @@ -211,12 +210,10 @@ void ide_complete_pm_rq(ide_drive_t *drive, struct request *rq) printk("%s: completing PM request, %s\n", drive->name, (ide_req(rq)->type == ATA_PRIV_PM_SUSPEND) ? "suspend" : "resume"); #endif - spin_lock_irqsave(&q->queue_lock, flags); if (ide_req(rq)->type == ATA_PRIV_PM_SUSPEND) blk_mq_stop_hw_queues(q); else drive->dev_flags &= ~IDE_DFLAG_BLOCKED; - spin_unlock_irqrestore(&q->queue_lock, flags); drive->hwif->rq = NULL;
blk_mq_stop_hw_queues doesn't need any locking, and the ide dev_flags field isn't protected by it either. Signed-off-by: Christoph Hellwig <hch@lst.de> --- drivers/ide/ide-pm.c | 3 --- 1 file changed, 3 deletions(-)