Re: [PATCH v2 15/17] ibmvfc: send Cancel MAD down each hw scsi channel
From: Brian King <hidden>
Date: 2020-12-02 18:28:43
Also in:
linux-scsi, lkml
On 12/1/20 6:53 PM, Tyrel Datwyler wrote:
quoted hunk ↗ jump to hunk
In general the client needs to send Cancel MADs and task management commands down the same channel as the command(s) intended to cancel or abort. The client assigns cancel keys per LUN and thus must send a Cancel down each channel commands were submitted for that LUN. Further, the client then must wait for those cancel completions prior to submitting a LUN RESET or ABORT TASK SET. Allocate event pointers for each possible scsi channel and assign an event for each channel that requires a cancel. Wait for completion each submitted cancel. Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com> --- drivers/scsi/ibmvscsi/ibmvfc.c | 106 +++++++++++++++++++++------------ 1 file changed, 68 insertions(+), 38 deletions(-)diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c index 0b6284020f06..97e8eed04b01 100644 --- a/drivers/scsi/ibmvscsi/ibmvfc.c +++ b/drivers/scsi/ibmvscsi/ibmvfc.c@@ -2339,32 +2339,52 @@ static int ibmvfc_cancel_all(struct scsi_device *sdev, int type) { struct ibmvfc_host *vhost = shost_priv(sdev->host); struct ibmvfc_event *evt, *found_evt; - union ibmvfc_iu rsp; - int rsp_rc = -EBUSY; + struct ibmvfc_event **evt_list; + union ibmvfc_iu *rsp; + int rsp_rc = 0; unsigned long flags; u16 status; + int num_hwq = 1; + int i; + int ret = 0; ENTER; spin_lock_irqsave(vhost->host->host_lock, flags); - found_evt = NULL; - list_for_each_entry(evt, &vhost->sent, queue) { - if (evt->cmnd && evt->cmnd->device == sdev) { - found_evt = evt; - break; + if (vhost->using_channels && vhost->scsi_scrqs.active_queues) + num_hwq = vhost->scsi_scrqs.active_queues; + + evt_list = kcalloc(num_hwq, sizeof(*evt_list), GFP_KERNE> + rsp = kcalloc(num_hwq, sizeof(*rsp), GFP_KERNEL);
Can't this just go on the stack? We don't want to be allocating memory during error recovery. Or, alternatively, you could put this in the vhost structure and protect it with a mutex. We only have enough events to single thread these anyway.
+
+ for (i = 0; i < num_hwq; i++) {
+ sdev_printk(KERN_INFO, sdev, "Cancelling outstanding commands on queue %d.\n", i);Prior to this patch, if there was nothing outstanding to the device and cancel_all was called, no messages would get printed. This is changing that behavior. Is that intentional? Additionally, it looks like this will get a lot more vebose, logging a message for each hw queue, regardless of whether there was anything outstanding. Perhaps you want to move this down to after the check for !found_evt?
+
+ found_evt = NULL;
+ list_for_each_entry(evt, &vhost->sent, queue) {
+ if (evt->cmnd && evt->cmnd->device == sdev && evt->hwq == i) {
+ found_evt = evt;
+ break;
+ }
}
- }
-- Brian King Power Linux I/O IBM Linux Technology Center