| Message ID | 1594275791-20662-1-git-send-email-sh425.lee@samsung.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [RFC,v1] sd: drain a request queue during sd_shutdown() | expand |
On 2020-07-08 23:23, Lee Sang Hyun wrote: > Need to set a request queue like below in sd_shutdown() > to prevent pending IOs before UFS shutdown. > > Change-Id: I2818cf95944d85baa50b626fcf538f19d06d6d54 > Signed-off-by: Lee Sang Hyun <sh425.lee@samsung.com> > --- > drivers/scsi/sd.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c > index d90feff..7418d27 100644 > --- a/drivers/scsi/sd.c > +++ b/drivers/scsi/sd.c > @@ -3564,6 +3564,8 @@ static int sd_start_stop_device(struct scsi_disk *sdkp, int start) > static void sd_shutdown(struct device *dev) > { > struct scsi_disk *sdkp = dev_get_drvdata(dev); > + struct request_queue *q = sdp->request_queue; > + unsigned long flags; > > if (!sdkp) > return; /* this can happen */ > @@ -3580,6 +3582,12 @@ static void sd_shutdown(struct device *dev) > sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n"); > sd_start_stop_device(sdkp, 0); > } > + > + spin_lock_irqsave(q->queue_lock, flags); > + queue_flag_set(QUEUE_FLAG_DYING, q); > + __blk_drain_queue(q, true); > + queue_flag_set(QUEUE_FLAG_DEAD, q); > + spin_unlock_irqrestore(q->queue_lock, flags); > } This patch is unacceptable because: (a) It introduces a layering violation. The code added in sd_shutdown() belongs in the block layer instead of the sd driver. (b) A description of which problem has been observed and why the sd driver is being modified is missing. (c) An explanation is missing why the blk_cleanup_queue() call in __scsi_remove_device() is not sufficient. As you may know blk_cleanup_queue() already drains the request queue. (d) The above patch breaks the kernel build. __blk_drain_queue() was removed from the kernel almost two years ago. See also commit a1ce35fa4985 ("block: remove dead elevator code") # v5.0. Bart.
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index d90feff..7418d27 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -3564,6 +3564,8 @@ static int sd_start_stop_device(struct scsi_disk *sdkp, int start) static void sd_shutdown(struct device *dev) { struct scsi_disk *sdkp = dev_get_drvdata(dev); + struct request_queue *q = sdp->request_queue; + unsigned long flags; if (!sdkp) return; /* this can happen */ @@ -3580,6 +3582,12 @@ static void sd_shutdown(struct device *dev) sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n"); sd_start_stop_device(sdkp, 0); } + + spin_lock_irqsave(q->queue_lock, flags); + queue_flag_set(QUEUE_FLAG_DYING, q); + __blk_drain_queue(q, true); + queue_flag_set(QUEUE_FLAG_DEAD, q); + spin_unlock_irqrestore(q->queue_lock, flags); } static int sd_suspend_common(struct device *dev, bool ignore_stop_errors)
Need to set a request queue like below in sd_shutdown() to prevent pending IOs before UFS shutdown. Change-Id: I2818cf95944d85baa50b626fcf538f19d06d6d54 Signed-off-by: Lee Sang Hyun <sh425.lee@samsung.com> --- drivers/scsi/sd.c | 8 ++++++++ 1 file changed, 8 insertions(+)