[PATCH 1/6] cciss: make rebuild_lun_table behave better

Mike Miller
2008-07-30T21:07:06Z

Patch 1 of 6

This patch makes the rebuild_lun_table smart enough to not rip a logical
volume out from under the OS. Without this fix if a customer is running
hpacucli to monitor their storage the driver will blindly remove and re-add
the disks whenever the utility calls the CCISS_REGNEWD ioctl. Unfortunately,
both hpacucli and ACUXE call the ioctl repeatedly. Customers have reported
IO coming to a standstill. Calling the ioctl is the problem, this patch is
the fix.
Please consider this patch for inclusion.

Thanks,
mikem

Signed-off-by: Stephen M. Cameron <scameron@beardog.cca.cpqcorp.net>
Signed-off-by: Mike Miller <mike.miller@hp.com>

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index d81632c..9b0dc00 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -1332,13 +1332,46 @@ static void cciss_softirq_done(struct request *rq)
spin_unlock_irqrestore(&h->lock, flags);
}

+/* This function gets the serial number of a logical drive via
+ * inquiry page 0x83. Serial no. is 16 bytes. If the serial
+ * number cannot be had, for whatever reason, 16 bytes of 0xff
+ * are returned instead.
+ */
+static void cciss_get_serial_no(int ctlr, int logvol, int withirq,
+ unsigned char *serial_no, int buflen)
+{
+#define PAGE_83_INQ_BYTES 64
+ int rc;
+ unsigned char *buf;
+
+ if (buflen > 16)
+ buflen = 16;
+ memset(serial_no, 0xff, buflen);
+ buf = kzalloc(PAGE_83_INQ_BYTES, GFP_KERNEL);
+ if (!buf)
+ return;
+ memset(serial_no, 0, buflen);
+ if (withirq)
+ rc = sendcmd_withirq(CISS_INQUIRY, ctlr, buf,
+ PAGE_83_INQ_BYTES, 1, logvol, 0x83, TYPE_CMD);
+ else
+ rc = sendcmd(CISS_INQUIRY, ctlr, buf,
+ PAGE_83_INQ_BYTES, 1, logvol, 0x83, NULL, TYPE_CMD);
+ if (rc == IO_OK)
+ memcpy(serial_no, &buf[8], buflen);
+ kfree(buf);
+ return;
+}
+
/* This function will check the usage_count of the drive to be updated/added.
- * If the usage_count is zero then the drive information will be updated and
- * the disk will be re-registered with the kernel. If not then it will be
- * left alone for the next reboot. The exception to this is disk 0 which
- * will always be left registered with the kernel since it is also the
- * controller node. Any changes to disk 0 will show up on the next
- * reboot.
+ * If the usage_count is zero and it is a heretofore unknown drive, or,
+ * the drive's capacity, geometry, or serial number has changed,
+ * then the drive information will be updated and the disk will be
+ * re-registered with the kernel. If these conditions don't hold,
+ * then it will be left alone for the next reboot. The exception to this
+ * is disk 0 which will always be left registered with the kernel since it
+ * is also the controller node. Any changes to disk 0 will show up on
+ * the next reboot.
*/
static void cciss_update_drive_info(int ctlr, int drv_index)
{
@@ -1349,9 +1382,65 @@ static void cciss_update_drive_info(int ctlr, int drv_index)
sector_t total_size;
unsigned long flags = 0;
int ret = 0;
+ drive_info_struct *drvinfo;
+
+ /* Get information about the disk and modify the driver structure */
+ inq_buff = kmalloc(sizeof(InquiryData_struct), GFP_KERNEL);
+ drvinfo = kmalloc(sizeof(*drvinfo), GFP_KERNEL);
+ if (inq_buff == NULL || drvinfo == NULL)
+ goto mem_msg;
+
+ /* testing to see if 16-byte CDBs are already being used */
+ if (h->cciss_read == CCISS_READ_16) {
+ cciss_read_capacity_16(h->ctlr, drv_index, 1,
+ &total_size, &block_size);
+
+ } else {
+ cciss_read_capacity(ctlr, drv_index, 1,
+ &total_size, &block_size);
+
+ /* if read_capacity returns all F's this volume is >2TB */
+ /* in size so we switch to 16-byte CDB's for all */
+ /* read/write ops */
+ if (total_size == 0xFFFFFFFFULL) {
+ cciss_read_capacity_16(ctlr, drv_index, 1,
+ &total_size, &block_size);
+ h->cciss_read = CCISS_READ_16;
+ h->cciss_write = CCISS_WRITE_16;
+ } else {
+ h->cciss_read = CCISS_READ_10;
+ h->cciss_write = CCISS_WRITE_10;
+ }
+ }
+
+ cciss_geometry_inquiry(ctlr, drv_index, 1, total_size, block_size,
+ inq_buff, drvinfo);
+ drvinfo->block_size = block_size;
+ drvinfo->nr_blocks = total_size + 1;
+
+ cciss_get_serial_no(ctlr, drv_index, 1, drvinfo->serial_no,
+ sizeof(drvinfo->serial_no));
+
+ /* Is it the same disk we already know, and nothing's changed? */
+ if (h->drv[drv_index].raid_level != -1 &&
+ ((memcmp(drvinfo->serial_no,
+ h->drv[drv_index].serial_no, 16) == 0) &&
+ drvinfo->block_size == h->drv[drv_index].block_size &&
+ drvinfo->nr_blocks == h->drv[drv_index].nr_blocks &&
+ drvinfo->heads == h->drv[drv_index].heads &&
+ drvinfo->sectors == h->drv[drv_index].sectors &&
+ drvinfo->cylinders == h->drv[drv_index].cylinders)) {
+ /* The disk is unchanged, nothing to update */
+ goto freeret;
+ }
+
+ /* Not the same disk, or something's changed, so we need to */
+ /* deregister it, and re-register it, if it's not in use. */

/* if the disk already exists then deregister it before proceeding */
- if (h->drv[drv_index].raid_level != -1) {
+ /* (unless it's the first disk (for the controller node). */
+ if (h->drv[drv_index].raid_level != -1 && drv_index != 0) {
+ printk(KERN_WARNING "disk %d has changed.\n", drv_index);
spin_lock_irqsave(CCISS_LOCK(h->ctlr), flags);
h->drv[drv_index].busy_configuring = 1;
spin_unlock_irqrestore(CCISS_LOCK(h->ctlr), flags);
@@ -1366,43 +1455,23 @@ static void cciss_update_drive_info(int ctlr, int drv_index)

/* If the disk is in use return */
if (ret)
- return;
-
- /* Get information about the disk and modify the driver structure */
- inq_buff = kmalloc(sizeof(InquiryData_struct), GFP_KERNEL);
- if (inq_buff == NULL)
- goto mem_msg;
-
- /* testing to see if 16-byte CDBs are already being used */
- if (h->cciss_read == CCISS_READ_16) {
- cciss_read_capacity_16(h->ctlr, drv_index, 1,
- &total_size, &block_size);
- goto geo_inq;
- }
-
- cciss_read_capacity(ctlr, drv_index, 1,
- &total_size, &block_size);
-
- /* if read_capacity returns all F's this volume is >2TB in size */
- /* so we switch to 16-byte CDB's for all read/write ops */
- if (total_size == 0xFFFFFFFFULL) {
- cciss_read_capacity_16(ctlr, drv_index, 1,
- &total_size, &block_size);
- h->cciss_read = CCISS_READ_16;
- h->cciss_write = CCISS_WRITE_16;
- } else {
- h->cciss_read = CCISS_READ_10;
- h->cciss_write = CCISS_WRITE_10;
- }
-geo_inq:
- cciss_geometry_inquiry(ctlr, drv_index, 1, total_size, block_size,
- inq_buff, &h->drv[drv_index]);
+ goto freeret;
+
+ /* Save the new information from cciss_geometry_inquiry */
+ /* and serial number inquiry. */
+ h->drv[drv_index].block_size = drvinfo->block_size;
+ h->drv[drv_index].nr_blocks = drvinfo->nr_blocks;
+ h->drv[drv_index].heads = drvinfo->heads;
+ h->drv[drv_index].sectors = drvinfo->sectors;
+ h->drv[drv_index].cylinders = drvinfo->cylinders;
+ h->drv[drv_index].raid_level = drvinfo->raid_level;
+ memcpy(h->drv[drv_index].serial_no, drvinfo->serial_no, 16);

++h->num_luns;
disk = h->gendisk[drv_index];
set_capacity(disk, h->drv[drv_index].nr_blocks);

- /* if it's the controller it's already added */
+ /* if it's the controller (if drv_index == 0) it's already added */
if (drv_index) {
disk->queue = blk_init_queue(do_cciss_request, &h->lock);
sprintf(disk->disk_name, "cciss/c%dd%d", ctlr, drv_index);
@@ -1439,6 +1508,7 @@ geo_inq:

freeret:
kfree(inq_buff);
+ kfree(drvinfo);
return;
mem_msg:
printk(KERN_ERR "cciss: out of memory\n");
@@ -1480,7 +1550,6 @@ static int rebuild_lun_table(ctlr_info_t *h, struct gendisk *del_disk)
int ctlr = h->ctlr;
int num_luns;
ReportLunData_struct *ld_buff = NULL;
- drive_info_struct *drv = NULL;
int return_code;
int listlength = 0;
int i;
@@ -1496,98 +1565,117 @@ static int rebuild_lun_table(ctlr_info_t *h, struct gendisk *del_disk)
return -EBUSY;
}
h->busy_configuring = 1;
+ spin_unlock_irqrestore(CCISS_LOCK(h->ctlr), flags);

- /* if del_disk is NULL then we are being called to add a new disk
- * and update the logical drive table. If it is not NULL then
- * we will check if the disk is in use or not.
- */
- if (del_disk != NULL) {
- drv = get_drv(del_disk);
- drv->busy_configuring = 1;
- spin_unlock_irqrestore(CCISS_LOCK(h->ctlr), flags);
- return_code = deregister_disk(del_disk, drv, 1);
- drv->busy_configuring = 0;
- h->busy_configuring = 0;
- return return_code;
- } else {
- spin_unlock_irqrestore(CCISS_LOCK(h->ctlr), flags);
- if (!capable(CAP_SYS_RAWIO))
- return -EPERM;
+ if (!capable(CAP_SYS_RAWIO))
+ return -EPERM;

- ld_buff = kzalloc(sizeof(ReportLunData_struct), GFP_KERNEL);
- if (ld_buff == NULL)
- goto mem_msg;
-
- return_code = sendcmd_withirq(CISS_REPORT_LOG, ctlr, ld_buff,
- sizeof(ReportLunData_struct), 0,
- 0, 0, TYPE_CMD);
-
- if (return_code == IO_OK) {
- listlength =
- be32_to_cpu(*(__be32 *) ld_buff->LUNListLength);
- } else { /* reading number of logical volumes failed */
- printk(KERN_WARNING "cciss: report logical volume"
- " command failed\n");
- listlength = 0;
- goto freeret;
- }
+ ld_buff = kzalloc(sizeof(ReportLunData_struct), GFP_KERNEL);
+ if (ld_buff == NULL)
+ goto mem_msg;
+
+ return_code = sendcmd_withirq(CISS_REPORT_LOG, ctlr, ld_buff,
+ sizeof(ReportLunData_struct), 0,
+ 0, 0, TYPE_CMD);

- num_luns = listlength / 8; /* 8 bytes per entry */
- if (num_luns > CISS_MAX_LUN) {
- num_luns = CISS_MAX_LUN;
- printk(KERN_WARNING "cciss: more luns configured"
- " on controller than can be handled by"
- " this driver.\n");
+ if (return_code == IO_OK)
+ listlength = be32_to_cpu(*(__be32 *) ld_buff->LUNListLength);
+ else { /* reading number of logical volumes failed */
+ printk(KERN_WARNING "cciss: report logical volume"
+ " command failed\n");
+ listlength = 0;
+ goto freeret;
+ }
+
+ num_luns = listlength / 8; /* 8 bytes per entry */
+ if (num_luns > CISS_MAX_LUN) {
+ num_luns = CISS_MAX_LUN;
+ printk(KERN_WARNING "cciss: more luns configured"
+ " on controller than can be handled by"
+ " this driver.\n");
+ }
+
+ /* Compare controller drive array to driver's drive array */
+ /* to see if any drives are missing on the controller due */
+ /* to action of Array Config Utility (user deletes drive) */
+ /* and deregister logical drives which have disappeared. */
+ for (i = 0; i <= h->highest_lun; i++) {
+ int j;
+ drv_found = 0;
+ for (j = 0; j < num_luns; j++) {
+ memcpy(&lunid, &ld_buff->LUN[j][0], 4);
+ lunid = le32_to_cpu(lunid);
+ if (h->drv[i].LunID == lunid) {
+ drv_found = 1;
+ break;
+ }
+ }
+ if (!drv_found) {
+ /* Deregister it from the OS, it's gone. */
+ spin_lock_irqsave(CCISS_LOCK(h->ctlr), flags);
+ h->drv[i].busy_configuring = 1;
+ spin_unlock_irqrestore(CCISS_LOCK(h->ctlr), flags);
+ return_code = deregister_disk(h->gendisk[i],
+ &h->drv[i], 1);
+ h->drv[i].busy_configuring = 0;
}
+ }

- /* Compare controller drive array to drivers drive array.
- * Check for updates in the drive information and any new drives
- * on the controller.
- */
- for (i = 0; i < num_luns; i++) {
- int j;
+ /* Compare controller drive array to driver's drive array.
+ * Check for updates in the drive information and any new drives
+ * on the controller due to ACU adding logical drives, or changing
+ * a logical drive's size, etc. Reregister any new/changed drives
+ */
+ for (i = 0; i < num_luns; i++) {
+ int j;

- drv_found = 0;
+ drv_found = 0;

- lunid = (0xff &
- (unsigned int)(ld_buff->LUN[i][3])) << 24;
- lunid |= (0xff &
- (unsigned int)(ld_buff->LUN[i][2])) << 16;
- lunid |= (0xff &
- (unsigned int)(ld_buff->LUN[i][1])) << 8;
- lunid |= 0xff & (unsigned int)(ld_buff->LUN[i][0]);
+ memcpy(&lunid, &ld_buff->LUN[i][0], 4);
+ lunid = le32_to_cpu(lunid);

- /* Find if the LUN is already in the drive array
- * of the controller. If so then update its info
- * if not is use. If it does not exist then find
- * the first free index and add it.
- */
- for (j = 0; j <= h->highest_lun; j++) {
- if (h->drv[j].LunID == lunid) {
- drv_index = j;
- drv_found = 1;
- }
+ /* Find if the LUN is already in the drive array
+ * of the driver. If so then update its info
+ * if not in use. If it does not exist then find
+ * the first free index and add it.
+ */
+ for (j = 0; j <= h->highest_lun; j++) {
+ if (h->drv[j].raid_level != -1 &&
+ h->drv[j].LunID == lunid) {
+ drv_index = j;
+ drv_found = 1;
+ break;
}
+ }

- /* check if the drive was found already in the array */
- if (!drv_found) {
- drv_index = cciss_find_free_drive_index(ctlr);
- if (drv_index == -1)
- goto freeret;
-
- /*Check if the gendisk needs to be allocated */
+ /* check if the drive was found already in the array */
+ if (!drv_found) {
+ drv_index = cciss_find_free_drive_index(ctlr);
+ if (drv_index == -1)
+ goto freeret;
+ /*Check if the gendisk needs to be allocated */
+ if (!h->gendisk[drv_index]) {
+ h->gendisk[drv_index] =
+ alloc_disk(1 << NWD_SHIFT);
if (!h->gendisk[drv_index]){
- h->gendisk[drv_index] = alloc_disk(1 << NWD_SHIFT);
- if (!h->gendisk[drv_index]){
- printk(KERN_ERR "cciss: could not allocate new disk %d\n", drv_index);
- goto mem_msg;
- }
+ printk(KERN_ERR "cciss: could not "
+ "allocate new disk %d\n",
+ drv_index);
+ goto mem_msg;
}
}
h->drv[drv_index].LunID = lunid;
- cciss_update_drive_info(ctlr, drv_index);
- } /* end for */
- } /* end else */
+
+ /* Don't need to mark this busy because nobody
+ * else knows about this disk yet to contend
+ * for access to it.
+ */
+ h->drv[drv_index].busy_configuring = 0;
+ wmb();
+
+ }
+ cciss_update_drive_info(ctlr, drv_index);
+ } /* end for */

freeret:
kfree(ld_buff);
@@ -1599,6 +1687,7 @@ static int rebuild_lun_table(ctlr_info_t *h, struct gendisk *del_disk)
return -1;
mem_msg:
printk(KERN_ERR "cciss: out of memory\n");
+ h->busy_configuring = 0;
goto freeret;
}

@@ -1654,15 +1743,15 @@ static int deregister_disk(struct gendisk *disk, drive_info_struct *drv,
* other than disk 0 we will call put_disk. We do not
* do this for disk 0 as we need it to be able to
* configure the controller.
- */
+ */
if (clear_all){
/* This isn't pretty, but we need to find the
* disk in our array and NULL our the pointer.
* This is so that we will call alloc_disk if
* this index is used again later.
- */
+ */
for (i=0; i < CISS_MAX_LUN; i++){
- if(h->gendisk[i] == disk){
+ if (h->gendisk[i] == disk) {
h->gendisk[i] = NULL;
break;
}
@@ -1690,7 +1779,7 @@ static int deregister_disk(struct gendisk *disk, drive_info_struct *drv,
if (drv == h->drv + h->highest_lun) {
/* if so, find the new hightest lun */
int i, newhighest = -1;
- for (i = 0; i < h->highest_lun; i++) {
+ for (i = 0; i <= h->highest_lun; i++) {
/* if the disk has size > 0, it is available */
if (h->drv[i].heads)
newhighest = i;
@@ -3320,6 +3409,9 @@ geo_inq:
cciss_geometry_inquiry(cntl_num, i, 0, total_size,
block_size, inq_buff,
&hba[cntl_num]->drv[i]);
+ cciss_get_serial_no(cntl_num, i, 0,
+ hba[cntl_num]->drv[i].serial_no,
+ sizeof(hba[cntl_num]->drv[i].serial_no));
} else {
/* initialize raid_level to indicate a free space */
hba[cntl_num]->drv[i].raid_level = -1;
diff --git a/drivers/block/cciss.h b/drivers/block/cciss.h
index b70988d..24a7efa 100644
--- a/drivers/block/cciss.h
+++ b/drivers/block/cciss.h
@@ -39,6 +39,8 @@ typedef struct _drive_info_struct
*to prevent it from being opened or it's queue
*from being started.
*/
+ __u8 serial_no[16]; /* from inquiry page 0x83, */
+ /* not necc. null terminated. */
} drive_info_struct;

#ifdef CONFIG_CISS_SCSI_TAPE