[patch 06/19] [PATCH] dpt_i2o fix for deadlock condition

Greg Kroah-Hartman
2005-12-23T22:51:15Z

[-- Attachment #1: dpt_i2o-fix-for-deadlock-condition.patch --]
[-- Type: text/plain, Size: 3051 bytes --]

-stable review patch. If anyone has any objections, please let us know.

------------------
From: "Salyzyn, Mark" <mark_salyzyn@adaptec.com>

Miquel van Smoorenburg <miquels@cistron.nl> forwarded me this fix to
resolve a deadlock condition that occurs due to the API change in 2.6.13+
kernels dropping the host locking when entering the error handling. They
all end up calling adpt_i2o_post_wait(), which if you call it unlocked,
might return with host_lock locked anyway and that causes a deadlock.

Signed-off-by: Mark Salyzyn <aacraid@adaptec.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Chris Wright <chrisw@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/scsi/dpt_i2o.c | 25 ++++++++++++++++++++-----
1 file changed, 20 insertions(+), 5 deletions(-)

--- linux-2.6.14.4.orig/drivers/scsi/dpt_i2o.c
+++ linux-2.6.14.4/drivers/scsi/dpt_i2o.c
@@ -660,7 +660,12 @@ static int adpt_abort(struct scsi_cmnd *
msg[2] = 0;
msg[3]= 0;
msg[4] = (u32)cmd;
- if( (rcode = adpt_i2o_post_wait(pHba, msg, sizeof(msg), FOREVER)) != 0){
+ if (pHba->host)
+ spin_lock_irq(pHba->host->host_lock);
+ rcode = adpt_i2o_post_wait(pHba, msg, sizeof(msg), FOREVER);
+ if (pHba->host)
+ spin_unlock_irq(pHba->host->host_lock);
+ if (rcode != 0) {
if(rcode == -EOPNOTSUPP ){
printk(KERN_INFO"%s: Abort cmd not supported\n",pHba->name);
return FAILED;
@@ -697,10 +702,15 @@ static int adpt_device_reset(struct scsi
msg[2] = 0;
msg[3] = 0;

+ if (pHba->host)
+ spin_lock_irq(pHba->host->host_lock);
old_state = d->state;
d->state |= DPTI_DEV_RESET;
- if( (rcode = adpt_i2o_post_wait(pHba, msg,sizeof(msg), FOREVER)) ){
- d->state = old_state;
+ rcode = adpt_i2o_post_wait(pHba, msg,sizeof(msg), FOREVER);
+ d->state = old_state;
+ if (pHba->host)
+ spin_unlock_irq(pHba->host->host_lock);
+ if (rcode != 0) {
if(rcode == -EOPNOTSUPP ){
printk(KERN_INFO"%s: Device reset not supported\n",pHba->name);
return FAILED;
@@ -708,7 +718,6 @@ static int adpt_device_reset(struct scsi
printk(KERN_INFO"%s: Device reset failed\n",pHba->name);
return FAILED;
} else {
- d->state = old_state;
printk(KERN_INFO"%s: Device reset successful\n",pHba->name);
return SUCCESS;
}
@@ -721,6 +730,7 @@ static int adpt_bus_reset(struct scsi_cm
{
adpt_hba* pHba;
u32 msg[4];
+ u32 rcode;

pHba = (adpt_hba*)cmd->device->host->hostdata[0];
memset(msg, 0, sizeof(msg));
@@ -729,7 +739,12 @@ static int adpt_bus_reset(struct scsi_cm
msg[1] = (I2O_HBA_BUS_RESET<<24|HOST_TID<<12|pHba->channel[cmd->device->channel].tid);
msg[2] = 0;
msg[3] = 0;
- if(adpt_i2o_post_wait(pHba, msg,sizeof(msg), FOREVER) ){
+ if (pHba->host)
+ spin_lock_irq(pHba->host->host_lock);
+ rcode = adpt_i2o_post_wait(pHba, msg,sizeof(msg), FOREVER);
+ if (pHba->host)
+ spin_unlock_irq(pHba->host->host_lock);
+ if (rcode != 0) {
printk(KERN_WARNING"%s: Bus reset failed.\n",pHba->name);
return FAILED;
} else {

--