RE: Transport affected timeouts...

RE: Transport affected timeouts...

[Smart, James]

> I know the way solaris does this is to have a global variable that
> allows you to raise the timeout.  If we simply exposed 
> Brian's proposed
> parameter in sysfs, so you could change it from user space, would that
> be sufficient?


Yes.

-- James S

Re: Transport affected timeouts...

[Brian King]

Smart, James wrote:
> 
>>I know the way solaris does this is to have a global variable that
>>allows you to raise the timeout.  If we simply exposed 
>>Brian's proposed
>>parameter in sysfs, so you could change it from user space, would that
>>be sufficient?
> 
> 
> 
> Yes.

I'll respin the patch.


-- 
Brian King
eServer Storage I/O
IBM Linux Technology Center

[PATCH] scsi_timeout_mod

[Brian King]

[-- Attachment #1: Type: text/plain, Size: 207 bytes --]

The following patch replaces the sd_timeout_mod patch I submitted earlier.
I renamed the field to simply "timeout" and exposed in in sysfs.




-- 
Brian King
eServer Storage I/O
IBM Linux Technology Center

[-- Attachment #2: scsi_timeout_mod.patch --]
[-- Type: text/plain, Size: 2715 bytes --]


This patch allows LLDs to override the default timeout used for scsi devices
and exposes it in sysfs. The default timeout value used is too short for
many RAID array devices, such as those created by the ipr driver.


---


diff -puN include/scsi/scsi_device.h~scsi_timeout_mod include/scsi/scsi_device.h
--- linux-2.6.6-rc3/include/scsi/scsi_device.h~scsi_timeout_mod	Fri Apr 30 09:51:49 2004
+++ linux-2.6.6-rc3-bjking1/include/scsi/scsi_device.h	Fri Apr 30 09:52:16 2004
@@ -111,6 +111,8 @@ struct scsi_device {
 	unsigned int max_device_blocked; /* what device_blocked counts down from  */
 #define SCSI_DEFAULT_DEVICE_BLOCKED	3
 
+	int timeout;
+
 	struct device		sdev_gendev;
 	struct class_device	sdev_classdev;
 
diff -puN drivers/scsi/scsi_sysfs.c~scsi_timeout_mod drivers/scsi/scsi_sysfs.c
--- linux-2.6.6-rc3/drivers/scsi/scsi_sysfs.c~scsi_timeout_mod	Fri Apr 30 09:52:43 2004
+++ linux-2.6.6-rc3-bjking1/drivers/scsi/scsi_sysfs.c	Fri Apr 30 09:53:56 2004
@@ -302,6 +302,26 @@ sdev_rd_attr (model, "%.16s\n");
 sdev_rd_attr (rev, "%.4s\n");
 
 static ssize_t
+sdev_show_timeout (struct device *dev, char *buf)
+{
+	struct scsi_device *sdev;
+	sdev = to_scsi_device(dev);
+	return snprintf (buf, 20, "%d\n", sdev->timeout / HZ);
+}
+
+static ssize_t
+sdev_store_timeout (struct device *dev, const char *buf, size_t count)
+{
+	struct scsi_device *sdev;
+	int timeout;
+	sdev = to_scsi_device(dev);
+	sscanf (buf, "%d\n", &timeout);
+	sdev->timeout = timeout * HZ;
+	return count;
+}
+static DEVICE_ATTR(timeout, S_IRUGO | S_IWUSR, sdev_show_timeout, sdev_store_timeout)
+
+static ssize_t
 store_rescan_field (struct device *dev, const char *buf, size_t count) 
 {
 	scsi_rescan_device(dev);
@@ -367,6 +387,7 @@ static struct device_attribute *scsi_sys
 	&dev_attr_rescan,
 	&dev_attr_delete,
 	&dev_attr_state,
+	&dev_attr_timeout,
 	NULL
 };
 
diff -puN drivers/scsi/sd.c~scsi_timeout_mod drivers/scsi/sd.c
--- linux-2.6.6-rc3/drivers/scsi/sd.c~scsi_timeout_mod	Fri Apr 30 09:54:04 2004
+++ linux-2.6.6-rc3-bjking1/drivers/scsi/sd.c	Fri Apr 30 09:55:42 2004
@@ -207,9 +207,7 @@ static int sd_init_command(struct scsi_c
 	sector_t block;
 	struct scsi_device *sdp = SCpnt->device;
 
-	timeout = SD_TIMEOUT;
-	if (SCpnt->device->type != TYPE_DISK)
-		timeout = SD_MOD_TIMEOUT;
+	timeout = sdp->timeout;
 
 	/*
 	 * these are already setup, just copy cdb basically
@@ -1382,6 +1380,13 @@ static int sd_probe(struct device *dev)
 	sdkp->index = index;
 	sdkp->openers = 0;
 
+	if (!sdp->timeout) {
+		if (sdp->type == TYPE_DISK)
+			sdp->timeout = SD_TIMEOUT;
+		else
+			sdp->timeout = SD_MOD_TIMEOUT;
+	}
+
 	devno = make_sd_dev(index, 0);
 	gd->major = MAJOR(devno);
 	gd->first_minor = MINOR(devno);

_

Re: Transport affected timeouts...

[Brian King]

[-- Attachment #1: Type: text/plain, Size: 201 bytes --]

The following patch makes st use the timeout field in the scsi_device struct.
It requires the scsi_timeout_mod patch I just submitted.



-- 
Brian King
eServer Storage I/O
IBM Linux Technology Center

[-- Attachment #2: st_timeout_mod.patch --]
[-- Type: text/plain, Size: 7146 bytes --]


This patch changes st to use the timeout field in the scsi_device struct
for the short timeout. This patch depends on scsi_timeout_mod patch.


---


diff -puN drivers/scsi/st.h~st_timeout_mod drivers/scsi/st.h
--- linux-2.6.6-rc3/drivers/scsi/st.h~st_timeout_mod	Fri Apr 30 09:56:04 2004
+++ linux-2.6.6-rc3-bjking1/drivers/scsi/st.h	Fri Apr 30 09:56:15 2004
@@ -100,7 +100,6 @@ typedef struct {
 	unsigned char c_algo;			/* compression algorithm */
 	unsigned char pos_unknown;			/* after reset position unknown */
 	int tape_type;
-	int timeout;		/* timeout for normal commands */
 	int long_timeout;	/* timeout for commands known to take long time */
 
 	unsigned long max_pfn;	/* the maximum page number reachable by the HBA */
diff -puN drivers/scsi/st.c~st_timeout_mod drivers/scsi/st.c
--- linux-2.6.6-rc3/drivers/scsi/st.c~st_timeout_mod	Fri Apr 30 09:56:19 2004
+++ linux-2.6.6-rc3-bjking1/drivers/scsi/st.c	Fri Apr 30 10:15:03 2004
@@ -486,7 +486,7 @@ static int cross_eof(Scsi_Tape * STp, in
 		   tape_name(STp), forward ? "forward" : "backward"));
 
 	SRpnt = st_do_scsi(NULL, STp, cmd, 0, SCSI_DATA_NONE,
-			   STp->timeout, MAX_RETRIES, TRUE);
+			   STp->device->timeout, MAX_RETRIES, TRUE);
 	if (!SRpnt)
 		return (STp->buffer)->syscall_result;
 
@@ -544,7 +544,7 @@ static int flush_write_buffer(Scsi_Tape 
 		cmd[4] = blks;
 
 		SRpnt = st_do_scsi(NULL, STp, cmd, transfer, SCSI_DATA_WRITE,
-				   STp->timeout, MAX_WRITE_RETRIES, TRUE);
+				   STp->device->timeout, MAX_WRITE_RETRIES, TRUE);
 		if (!SRpnt)
 			return (STp->buffer)->syscall_result;
 
@@ -867,7 +867,7 @@ static int check_tape(Scsi_Tape *STp, st
 		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
 		cmd[0] = READ_BLOCK_LIMITS;
 
-		SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, SCSI_DATA_READ, STp->timeout,
+		SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, SCSI_DATA_READ, STp->device->timeout,
 				   MAX_READY_RETRIES, TRUE);
 		if (!SRpnt) {
 			retval = (STp->buffer)->syscall_result;
@@ -894,7 +894,7 @@ static int check_tape(Scsi_Tape *STp, st
 	cmd[0] = MODE_SENSE;
 	cmd[4] = 12;
 
-	SRpnt = st_do_scsi(SRpnt, STp, cmd, 12, SCSI_DATA_READ, STp->timeout,
+	SRpnt = st_do_scsi(SRpnt, STp, cmd, 12, SCSI_DATA_READ, STp->device->timeout,
 			   MAX_READY_RETRIES, TRUE);
 	if (!SRpnt) {
 		retval = (STp->buffer)->syscall_result;
@@ -1115,7 +1115,7 @@ static int st_flush(struct file *filp)
 		cmd[4] = 1 + STp->two_fm;
 
 		SRpnt = st_do_scsi(NULL, STp, cmd, 0, SCSI_DATA_NONE,
-				   STp->timeout, MAX_WRITE_RETRIES, TRUE);
+				   STp->device->timeout, MAX_WRITE_RETRIES, TRUE);
 		if (!SRpnt) {
 			result = (STp->buffer)->syscall_result;
 			goto out;
@@ -1506,7 +1506,7 @@ static ssize_t
 		cmd[4] = blks;
 
 		SRpnt = st_do_scsi(SRpnt, STp, cmd, transfer, SCSI_DATA_WRITE,
-				   STp->timeout, MAX_WRITE_RETRIES, !async_write);
+				   STp->device->timeout, MAX_WRITE_RETRIES, !async_write);
 		if (!SRpnt) {
 			retval = STbp->syscall_result;
 			goto out;
@@ -1676,7 +1676,7 @@ static long read_tape(Scsi_Tape *STp, lo
 
 	SRpnt = *aSRpnt;
 	SRpnt = st_do_scsi(SRpnt, STp, cmd, bytes, SCSI_DATA_READ,
-			   STp->timeout, MAX_RETRIES, TRUE);
+			   STp->device->timeout, MAX_RETRIES, TRUE);
 	release_buffering(STp);
 	*aSRpnt = SRpnt;
 	if (!SRpnt)
@@ -2075,7 +2075,7 @@ static int st_set_options(Scsi_Tape *STp
 			printk(KERN_INFO "%s: Long timeout set to %d seconds.\n", name,
 			       (value & ~MT_ST_SET_LONG_TIMEOUT));
 		} else {
-			STp->timeout = value * HZ;
+			STp->device->timeout = value * HZ;
 			printk(KERN_INFO "%s: Normal timeout set to %d seconds.\n",
                                name, value);
 		}
@@ -2183,7 +2183,7 @@ static int read_mode_page(Scsi_Tape *STp
 	cmd[4] = 255;
 
 	SRpnt = st_do_scsi(SRpnt, STp, cmd, cmd[4], SCSI_DATA_READ,
-			   STp->timeout, 0, TRUE);
+			   STp->device->timeout, 0, TRUE);
 	if (SRpnt == NULL)
 		return (STp->buffer)->syscall_result;
 
@@ -2214,7 +2214,7 @@ static int write_mode_page(Scsi_Tape *ST
 	(STp->buffer)->b_data[pgo + MP_OFF_PAGE_NBR] &= MP_MSK_PAGE_NBR;
 
 	SRpnt = st_do_scsi(SRpnt, STp, cmd, cmd[4], SCSI_DATA_WRITE,
-			   (slow ? STp->long_timeout : STp->timeout), 0, TRUE);
+			   (slow ? STp->long_timeout : STp->device->timeout), 0, TRUE);
 	if (SRpnt == NULL)
 		return (STp->buffer)->syscall_result;
 
@@ -2326,7 +2326,7 @@ static int do_load_unload(Scsi_Tape *STp
 	}
 	if (STp->immediate) {
 		cmd[1] = 1;	/* Don't wait for completion */
-		timeout = STp->timeout;
+		timeout = STp->device->timeout;
 	}
 	else
 		timeout = STp->long_timeout;
@@ -2506,7 +2506,7 @@ static int st_int_ioctl(Scsi_Tape *STp, 
 		cmd[2] = (arg >> 16);
 		cmd[3] = (arg >> 8);
 		cmd[4] = arg;
-		timeout = STp->timeout;
+		timeout = STp->device->timeout;
                 DEBC(
                      if (cmd_in == MTWEOF)
                                printk(ST_DEB_MSG "%s: Writing %d filemarks.\n", name,
@@ -2524,7 +2524,7 @@ static int st_int_ioctl(Scsi_Tape *STp, 
 		cmd[0] = REZERO_UNIT;
 		if (STp->immediate) {
 			cmd[1] = 1;	/* Don't wait for completion */
-			timeout = STp->timeout;
+			timeout = STp->device->timeout;
 		}
                 DEBC(printk(ST_DEB_MSG "%s: Rewinding tape.\n", name));
 		fileno = blkno = at_sm = 0;
@@ -2537,7 +2537,7 @@ static int st_int_ioctl(Scsi_Tape *STp, 
 		cmd[0] = START_STOP;
 		if (STp->immediate) {
 			cmd[1] = 1;	/* Don't wait for completion */
-			timeout = STp->timeout;
+			timeout = STp->device->timeout;
 		}
 		cmd[4] = 3;
                 DEBC(printk(ST_DEB_MSG "%s: Retensioning tape.\n", name));
@@ -2570,7 +2570,7 @@ static int st_int_ioctl(Scsi_Tape *STp, 
 		cmd[1] = (arg ? 1 : 0);	/* Long erase with non-zero argument */
 		if (STp->immediate) {
 			cmd[1] |= 2;	/* Don't wait for completion */
-			timeout = STp->timeout;
+			timeout = STp->device->timeout;
 		}
 		else
 			timeout = STp->long_timeout * 8;
@@ -2622,7 +2622,7 @@ static int st_int_ioctl(Scsi_Tape *STp, 
 		(STp->buffer)->b_data[9] = (ltmp >> 16);
 		(STp->buffer)->b_data[10] = (ltmp >> 8);
 		(STp->buffer)->b_data[11] = ltmp;
-		timeout = STp->timeout;
+		timeout = STp->device->timeout;
                 DEBC(
 			if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK)
 				printk(ST_DEB_MSG
@@ -2803,7 +2803,7 @@ static int get_location(Scsi_Tape *STp, 
 		if (!logical && !STp->scsi2_logical)
 			scmd[1] = 1;
 	}
-	SRpnt = st_do_scsi(NULL, STp, scmd, 20, SCSI_DATA_READ, STp->timeout,
+	SRpnt = st_do_scsi(NULL, STp, scmd, 20, SCSI_DATA_READ, STp->device->timeout,
 			   MAX_READY_RETRIES, TRUE);
 	if (!SRpnt)
 		return (STp->buffer)->syscall_result;
@@ -2905,7 +2905,7 @@ static int set_location(Scsi_Tape *STp, 
 	}
 	if (STp->immediate) {
 		scmd[1] |= 1;		/* Don't wait for completion */
-		timeout = STp->timeout;
+		timeout = STp->device->timeout;
 	}
 
 	SRpnt = st_do_scsi(NULL, STp, scmd, 0, SCSI_DATA_NONE,
@@ -3844,7 +3844,7 @@ static int st_probe(struct device *dev)
 	tpnt->partition = 0;
 	tpnt->new_partition = 0;
 	tpnt->nbr_partitions = 0;
-	tpnt->timeout = ST_TIMEOUT;
+	tpnt->device->timeout = ST_TIMEOUT;
 	tpnt->long_timeout = ST_LONG_TIMEOUT;
 	tpnt->try_dio = try_direct_io && !SDp->host->unchecked_isa_dma;
 

_

Re: [PATCH] scsi_timeout_mod

[Masao Fukuchi]

Hi Brian,

I had a chance to use pseudo-I/O system, I tested your patch and
it worked fine.
First, I set the value of timeout to 10 seconds.
Then I accessed the device which doesn't respond to the command.
10 seconds later, scsi midlayer detected timeout and issued abort
task message.

Since we consider the early change of broken device/path, this patch
is very useful.

Thanks,
Masao Fukuchi

Brian King wrote:
>The following patch replaces the sd_timeout_mod patch I submitted earlier.
>I renamed the field to simply "timeout" and exposed in in sysfs.
>
>
>
>
>-- 
>Brian King
>eServer Storage I/O
>IBM Linux Technology Center