On Tue, Mar 10, 2009 at 10:17:38AM -0500, Mike Miller (OS Dev) wrote:
> Patch 1 of 1
>
> This is yet another go at the patch to detect changes on the MSA2012.
> I hope I've addressed all concerns. This patch rearranges some of the code
> so we also have coverage in the sg and the ioctl paths as well as the main
> data path.
>
> The MSA2012 cannot inform the driver of configuration changes since all
> management is out of band. This is a departure from any storage we have
> supported in the past. We need some way to detect changes on the topology so
> we implement this kernel thread. In some instances there's nothing we can do
> from the driver (like LUN failure) so just print out a message. In the case
> where logical volumes are added or deleted we call rebuild_lun_table to
> refresh the driver's view of the world.
>
> Changelog:
> 1. Do the completion(hba[i]->rescan_wait) before calling kthread_stop,
> this resolves the issue of waiting for the timeout on rmmod
> 2. Added a new function called check_ioctl_unit_attention to cover UA's
> from the ioctl patch
> 3. I preserved the wait_for_completion_timeout to avoid call traces
> caused by /proc/sys/kernel/hung_task_timeout_secs expiring
> 4. Moved the call to check_for_unit_attention to evaluate_target_status
> since it's already called from complete_command
> 5. Add retry_cmd as an argument to evaluate_target_status
> 6. Added *rescan_wait to the controller info struct
> 7. Changed wait_for_completion_timeout to wait_for_completion_interruptible.
> This will allow kthread_should_stop to stop the thread immediately with no race.
>
Andrew,
Did you have a comment? I don't see any, unless I've missed them.
-- mikem
> Please consider this for inclusion.
>
> Signed-off-by: Mike Miller <mike.miller@xxxxxx>
>
> diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
> index d2cb67b..35d7ad7 100644
> --- a/drivers/block/cciss.c
> +++ b/drivers/block/cciss.c
> @@ -51,6 +51,7 @@
> #include <scsi/scsi_ioctl.h>
> #include <linux/cdrom.h>
> #include <linux/scatterlist.h>
> +#include <linux/kthread.h>
>
> #define CCISS_DRIVER_VERSION(maj,min,submin) ((maj<<16)|(min<<8)|(submin))
> #define DRIVER_NAME "HP CISS Driver (v 3.6.20)"
> @@ -186,6 +187,8 @@ static int sendcmd_withirq(__u8 cmd, int ctlr, void *buff, size_t size,
> __u8 page_code, int cmd_type);
>
> static void fail_all_cmds(unsigned long ctlr);
> +static int scan_thread(ctlr_info_t *h);
> +static int check_for_unit_attention(ctlr_info_t *h, CommandList_struct *c);
>
> #ifdef CONFIG_PROC_FS
> static void cciss_procinit(int i);
> @@ -735,6 +738,12 @@ static int cciss_getgeo(struct block_device *bdev, struct hd_geometry *geo)
> return 0;
> }
>
> +static void check_ioctl_unit_attention(ctlr_info_t *host, CommandList_struct *c)
> +{
> + if (c->err_info->CommandStatus == CMD_TARGET_STATUS &&
> + c->err_info->ScsiStatus != SAM_STAT_CHECK_CONDITION)
> + (void)check_for_unit_attention(host, c);
> +}
> /*
> * ioctl
> */
> @@ -1029,6 +1038,8 @@ static int cciss_ioctl(struct block_device *bdev, fmode_t mode,
> iocommand.buf_size,
> PCI_DMA_BIDIRECTIONAL);
>
> + check_ioctl_unit_attention(host, c);
> +
> /* Copy the error information out */
> iocommand.error_info = *(c->err_info);
> if (copy_to_user
> @@ -1180,6 +1191,7 @@ static int cciss_ioctl(struct block_device *bdev, fmode_t mode,
> (dma_addr_t) temp64.val, buff_size[i],
> PCI_DMA_BIDIRECTIONAL);
> }
> + check_ioctl_unit_attention(host, c);
> /* Copy the error information out */
> ioc->error_info = *(c->err_info);
> if (copy_to_user(argp, ioc, sizeof(*ioc))) {
> @@ -2585,12 +2597,14 @@ static inline unsigned int make_status_bytes(unsigned int scsi_status_byte,
> ((driver_byte & 0xff) << 24);
> }
>
> -static inline int evaluate_target_status(CommandList_struct *cmd)
> +static inline int evaluate_target_status(ctlr_info_t *h,
> + CommandList_struct *cmd, int *retry_cmd)
> {
> unsigned char sense_key;
> unsigned char status_byte, msg_byte, host_byte, driver_byte;
> int error_value;
>
> + *retry_cmd = 0;
> /* If we get in here, it means we got "target status", that is, scsi status */
> status_byte = cmd->err_info->ScsiStatus;
> driver_byte = DRIVER_OK;
> @@ -2618,6 +2632,11 @@ static inline int evaluate_target_status(CommandList_struct *cmd)
> if (((sense_key == 0x0) || (sense_key == 0x1)) && !blk_pc_request(cmd->rq))
> error_value = 0;
>
> + if (check_for_unit_attention(h, cmd)) {
> + *retry_cmd = !blk_pc_request(cmd->rq);
> + return 0;
> + }
> +
> if (!blk_pc_request(cmd->rq)) { /* Not SG_IO or similar? */
> if (error_value != 0)
> printk(KERN_WARNING "cciss: cmd %p has CHECK CONDITION"
> @@ -2657,7 +2676,7 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
>
> switch (cmd->err_info->CommandStatus) {
> case CMD_TARGET_STATUS:
> - rq->errors = evaluate_target_status(cmd);
> + rq->errors = evaluate_target_status(h, cmd, &retry_cmd);
> break;
> case CMD_DATA_UNDERRUN:
> if (blk_fs_request(cmd->rq)) {
> @@ -3008,6 +3027,62 @@ static irqreturn_t do_cciss_intr(int irq, void *dev_id)
> return IRQ_HANDLED;
> }
>
> +static int scan_thread(ctlr_info_t *h)
> +{
> + int rc;
> + DECLARE_COMPLETION_ONSTACK(wait);
> + h->rescan_wait = &wait;
> +
> + while (!kthread_should_stop()) {
> + rc = wait_for_completion_interruptible(&wait);
> + if (!rc)
> + continue;
> + else
> + rebuild_lun_table(h, 0);
> + }
> + return 0;
> +}
> +
> +static int check_for_unit_attention(ctlr_info_t *h, CommandList_struct *c)
> +{
> + if (c->err_info->SenseInfo[2] != UNIT_ATTENTION)
> + return 0;
> +
> + switch (c->err_info->SenseInfo[12]) {
> + case STATE_CHANGED:
> + printk(KERN_WARNING "cciss%d: a state change "
> + "detected, command retried\n", h->ctlr);
> + return 1;
> + break;
> + case LUN_FAILED:
> + printk(KERN_WARNING "cciss%d: LUN failure "
> + "detected, action required\n", h->ctlr);
> + return 1;
> + break;
> + case REPORT_LUNS_CHANGED:
> + printk(KERN_WARNING "cciss%d: report LUN data "
> + "changed\n", h->ctlr);
> + if (h->rescan_wait)
> + complete(h->rescan_wait);
> + return 1;
> + break;
> + case POWER_OR_RESET:
> + printk(KERN_WARNING "cciss%d: a power on "
> + "or device reset detected\n", h->ctlr);
> + return 1;
> + break;
> + case UNIT_ATTENTION_CLEARED:
> + printk(KERN_WARNING "cciss%d: unit attention "
> + "cleared by another initiator\n", h->ctlr);
> + return 1;
> + break;
> + default:
> + printk(KERN_WARNING "cciss%d: unknown "
> + "unit attention detected\n", h->ctlr);
> + return 1;
> + }
> +}
> +
> /*
> * We cannot read the structure directly, for portability we must use
> * the io functions.
> @@ -3600,6 +3675,7 @@ static int __devinit cciss_init_one(struct pci_dev *pdev,
> int rc;
> int dac, return_code;
> InquiryData_struct *inq_buff = NULL;
> + char cciss_scan[14];
>
> if (reset_devices) {
> /* Reset the controller with a PCI power-cycle */
> @@ -3751,6 +3827,12 @@ static int __devinit cciss_init_one(struct pci_dev *pdev,
> hba[i]->busy_initializing = 0;
>
> rebuild_lun_table(hba[i], 1);
> + snprintf(cciss_scan, 14, "cciss_scan%02d", i);
> + hba[i]->cciss_scan_thread = kthread_run((void *)scan_thread, hba[i],
> + cciss_scan);
> + if (IS_ERR(hba[i]->cciss_scan_thread))
> + return PTR_ERR(hba[i]->cciss_scan_thread);
> +
> return 1;
>
> clean4:
> @@ -3826,6 +3908,7 @@ static void __devexit cciss_remove_one(struct pci_dev *pdev)
> printk(KERN_ERR "cciss: Unable to remove device \n");
> return;
> }
> +
> tmp_ptr = pci_get_drvdata(pdev);
> i = tmp_ptr->ctlr;
> if (hba[i] == NULL) {
> @@ -3834,6 +3917,9 @@ static void __devexit cciss_remove_one(struct pci_dev *pdev)
> return;
> }
>
> + kthread_stop(hba[i]->cciss_scan_thread);
> + complete(hba[i]->rescan_wait);
> +
> remove_proc_entry(hba[i]->devname, proc_cciss);
> unregister_blkdev(hba[i]->major, hba[i]->devname);
>
> diff --git a/drivers/block/cciss.h b/drivers/block/cciss.h
> index 15e2b84..703e080 100644
> --- a/drivers/block/cciss.h
> +++ b/drivers/block/cciss.h
> @@ -121,6 +121,8 @@ struct ctlr_info
> struct sendcmd_reject_list scsi_rejects;
> #endif
> unsigned char alive;
> + struct completion *rescan_wait;
> + struct task_struct *cciss_scan_thread;
> };
>
> /* Defining the diffent access_menthods */
> diff --git a/drivers/block/cciss_cmd.h b/drivers/block/cciss_cmd.h
> index 24e22de..40b1b92 100644
> --- a/drivers/block/cciss_cmd.h
> +++ b/drivers/block/cciss_cmd.h
> @@ -25,6 +25,29 @@
> #define CMD_TIMEOUT 0x000B
> #define CMD_UNABORTABLE 0x000C
>
> +/* Unit Attentions ASC's as defined for the MSA2012sa */
> +#define POWER_OR_RESET 0x29
> +#define STATE_CHANGED 0x2a
> +#define UNIT_ATTENTION_CLEARED 0x2f
> +#define LUN_FAILED 0x3e
> +#define REPORT_LUNS_CHANGED 0x3f
> +
> +/* Unit Attentions ASCQ's as defined for the MSA2012sa */
> +
> + /* These ASCQ's defined for ASC = POWER_OR_RESET */
> +#define POWER_ON_RESET 0x00
> +#define POWER_ON_REBOOT 0x01
> +#define SCSI_BUS_RESET 0x02
> +#define MSA_TARGET_RESET 0x03
> +#define CONTROLLER_FAILOVER 0x04
> +#define TRANSCEIVER_SE 0x05
> +#define TRANSCEIVER_LVD 0x06
> +
> + /* These ASCQ's defined for ASC = STATE_CHANGED */
> +#define RESERVATION_PREEMPTED 0x03
> +#define ASYM_ACCESS_CHANGED 0x06
> +#define LUN_CAPACITY_CHANGED 0x09
> +
> //transfer direction
> #define XFER_NONE 0x00
> #define XFER_WRITE 0x01
--
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