Re: Oops in scsi_send_eh_cmnd 2.6.21-rc5-git6,7,10,13

From: Andrew Burgess
Date: Fri Apr 06 2007 - 11:17:52 EST

James Bottomley said:

> On Thu, 2007-04-05 at 19:21 -0700, Andrew Burgess wrote:
> > 2.6.20.4 with your patch dies in the memcpy (as does 21-gitN)
> >
> > 2.6.20.4 without your patch dies in the subsequent __free_page
> > with a null pointer ref at 000...008
> >
> > James should I try your posted patch? On which kernel?
>
> Well, mine will work, but will also cover up the problem. It looks like
> the scatterlist is getting corrupted by the HBA driver somehow ... we
> really need to root cause this, otherwise other things will go wrong in
> strange ways.
>
> Just to confirm, the HBA with the problem is 3w-xxxx?

Yes. The 3w-xxxx.c driver changed between 2.6.18 and 2.6.20 but
nothing jumps out to my untrained eyes. Here's the diff:
Also, I should mention that the working kernel is a fedora
rpm (2.6.18-1.2798.fc6) so I don't know what patches are in it.
The vmlinuz is dated Oct 6 2006.

--------------------------------------------------------------------

root@athlon:kernel # diff -u linux-2.6.20-rt5/drivers/scsi/3w-xxxx.c linux-2.6.18.6/drivers/scsi/3w-xxxx.c
--- linux-2.6.20-rt5/drivers/scsi/3w-xxxx.c 2007-02-04 10:44:54.000000000 -0800
+++ linux-2.6.18.6/drivers/scsi/3w-xxxx.c 2006-12-16 16:21:00.000000000 -0800
@@ -6,7 +6,7 @@
Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxx>
Brad Strand <linux@xxxxxxxxx>

- Copyright (C) 1999-2007 3ware Inc.
+ Copyright (C) 1999-2005 3ware Inc.

Kernel compatiblity By: Andre Hedrick <andre@xxxxxxxx>
Non-Copyright (C) 2000 Andre Hedrick <andre@xxxxxxxx>
@@ -191,9 +191,6 @@
before shutting down card.
Change to new 'change_queue_depth' api.
Fix 'handled=1' ISR usage, remove bogus IRQ check.
- 1.26.02.002 - Free irq handler in __tw_shutdown().
- Turn on RCD bit for caching mode page.
- Serialize reset code.
*/

#include <linux/module.h>
@@ -217,7 +214,7 @@
#include "3w-xxxx.h"

/* Globals */
-#define TW_DRIVER_VERSION "1.26.02.002"
+#define TW_DRIVER_VERSION "1.26.02.001"
static TW_Device_Extension *tw_device_extension_list[TW_MAX_SLOT];
static int tw_device_extension_count = 0;
static int twe_major = -1;
@@ -229,7 +226,7 @@
MODULE_VERSION(TW_DRIVER_VERSION);

/* Function prototypes */
-static int tw_reset_device_extension(TW_Device_Extension *tw_dev);
+static int tw_reset_device_extension(TW_Device_Extension *tw_dev, int ioctl_reset);

/* Functions */

@@ -987,12 +984,24 @@
/* Now wait for the command to complete */
timeout = wait_event_timeout(tw_dev->ioctl_wqueue,
tw_dev->chrdev_request_id == TW_IOCTL_CHRDEV_FREE, timeout);

+ /* See if we reset while waiting for the ioctl to complete */
+ if (test_bit(TW_IN_RESET, &tw_dev->flags)) {
+ clear_bit(TW_IN_RESET, &tw_dev->flags);
+ retval = -ERESTARTSYS;
+ goto out2;
+ }
+
/* We timed out, and didn't get an interrupt */
if (tw_dev->chrdev_request_id != TW_IOCTL_CHRDEV_FREE) {
/* Now we need to reset the board */
printk(KERN_WARNING "3w-xxxx: scsi%d: Character ioctl (0x%x) timed
out, resetting card.\n", tw_dev->host->host_no, cmd);
retval = -EIO;
- if (tw_reset_device_extension(tw_dev)) {
+ spin_lock_irqsave(tw_dev->host->host_lock, flags);
+ tw_dev->state[request_id] = TW_S_COMPLETED;
+ tw_state_request_finish(tw_dev, request_id);
+ tw_dev->posted_request_count--;
+ spin_unlock_irqrestore(tw_dev->host->host_lock, flags);
+ if (tw_reset_device_extension(tw_dev, 1)) {
printk(KERN_WARNING "3w-xxxx: tw_chrdev_ioctl(): Reset
failed for card %d.\n", tw_dev->host->host_no);
}
goto out2;
@@ -1327,7 +1336,7 @@
} /* End tw_unmap_scsi_data() */

/* This function will reset a device extension */
-static int tw_reset_device_extension(TW_Device_Extension *tw_dev)
+static int tw_reset_device_extension(TW_Device_Extension *tw_dev, int ioctl_reset)
{
int i = 0;
struct scsi_cmnd *srb;
@@ -1373,10 +1382,15 @@
printk(KERN_WARNING "3w-xxxx: scsi%d: Reset sequence failed.\n",
tw_dev->host->host_no);
return 1;
}
-
TW_ENABLE_AND_CLEAR_INTERRUPTS(tw_dev);
- clear_bit(TW_IN_RESET, &tw_dev->flags);
- tw_dev->chrdev_request_id = TW_IOCTL_CHRDEV_FREE;
+
+ /* Wake up any ioctl that was pending before the reset */
+ if ((tw_dev->chrdev_request_id == TW_IOCTL_CHRDEV_FREE) || (ioctl_reset)) {
+ clear_bit(TW_IN_RESET, &tw_dev->flags);
+ } else {
+ tw_dev->chrdev_request_id = TW_IOCTL_CHRDEV_FREE;
+ wake_up(&tw_dev->ioctl_wqueue);
+ }

return 0;
} /* End tw_reset_device_extension() */
@@ -1423,18 +1437,14 @@
"WARNING: Command (0x%x) timed out, resetting card.\n",
SCpnt->cmnd[0]);

- /* Make sure we are not issuing an ioctl or resetting from ioctl */
- mutex_lock(&tw_dev->ioctl_lock);
-
/* Now reset the card and some of the device extension data */
- if (tw_reset_device_extension(tw_dev)) {
+ if (tw_reset_device_extension(tw_dev, 0)) {
printk(KERN_WARNING "3w-xxxx: scsi%d: Reset failed.\n", tw_dev->host->host_no);
goto out;
}

retval = SUCCESS;
out:
- mutex_unlock(&tw_dev->ioctl_lock);
return retval;
} /* End tw_scsi_eh_reset() */

@@ -1650,9 +1660,9 @@
request_buffer[4] = 0x8; /* caching page */
request_buffer[5] = 0xa; /* page length */
if (*flags & 0x1)
- request_buffer[6] = 0x5; /* WCE on, RCD on */
+ request_buffer[6] = 0x4; /* WCE on */
else
- request_buffer[6] = 0x1; /* WCE off, RCD on */
+ request_buffer[6] = 0x0; /* WCE off */
tw_transfer_internal(tw_dev, request_id, request_buffer,
sizeof(request_buffer));

@@ -2002,10 +2012,6 @@
int retval = 1;
TW_Device_Extension *tw_dev = (TW_Device_Extension *)SCpnt->device->host->hostdata;

- /* If we are resetting due to timed out ioctl, report as busy */
- if (test_bit(TW_IN_RESET, &tw_dev->flags))
- return SCSI_MLQUEUE_HOST_BUSY;
-
/* Save done function into Scsi_Cmnd struct */
SCpnt->scsi_done = done;

@@ -2072,7 +2078,8 @@
} /* End tw_scsi_queue() */

/* This function is the interrupt service routine */
-static irqreturn_t tw_interrupt(int irq, void *dev_instance)
+static irqreturn_t tw_interrupt(int irq, void *dev_instance,
+ struct pt_regs *regs)
{
int request_id;
u32 status_reg_value;
@@ -2094,10 +2101,6 @@

handled = 1;

- /* If we are resetting, bail */
- if (test_bit(TW_IN_RESET, &tw_dev->flags))
- goto tw_interrupt_bail;
-
/* Check controller for errors */
if (tw_check_bits(status_reg_value)) {
dprintk(KERN_WARNING "3w-xxxx: tw_interrupt(): Unexpected bits.\n");
@@ -2274,9 +2277,6 @@
/* Disable interrupts */
TW_DISABLE_INTERRUPTS(tw_dev);

- /* Free up the IRQ */
- free_irq(tw_dev->tw_pci_dev->irq, tw_dev);
-
printk(KERN_WARNING "3w-xxxx: Shutting down host %d.\n", tw_dev->host->host_no);

/* Tell the card we are shutting down */
@@ -2445,6 +2445,9 @@
twe_major = -1;
}

+ /* Free up the IRQ */
+ free_irq(tw_dev->tw_pci_dev->irq, tw_dev);
+
/* Shutdown the card */
__tw_shutdown(tw_dev);

@@ -2483,7 +2486,7 @@
{
printk(KERN_WARNING "3ware Storage Controller device driver for Linux v%s.\n",
TW_DRIVER_VERSION);

- return pci_register_driver(&tw_driver);
+ return pci_module_init(&tw_driver);
} /* End tw_init() */

/* This function is called on driver exit */


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