[PATCH v3 4/6] scsi_error: fix invalid setting of host byte

From: Paolo Bonzini
Date: Wed Jun 04 2014 - 07:42:11 EST


From: Ulrich Obergfell <uobergfe@xxxxxxxxxx>

After scsi_try_to_abort_cmd returns, the eh_abort_handler may have
already found that the command has completed in the device, causing
the host_byte to be nonzero (e.g. it could be DID_ABORT). When
this happens, ORing DID_TIME_OUT into the host byte will corrupt
the result field and initiate an unwanted command retry.

Fix this by using set_host_byte instead, following the model of
commit 2082ebc45af9c9c648383b8cde0dc1948eadbf31.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Ulrich Obergfell <uobergfe@xxxxxxxxxx>
[Fix all instances according to review comments. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
v1->v2: fix all occurrences [Bart] except one
v2->v3: really fix all occurrences [Bart]

drivers/scsi/scsi_error.c | 6 +++---
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index f17aa7aa7879..8e7a0f8d4f52 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -131,7 +131,7 @@ scmd_eh_abort_handler(struct work_struct *work)
"aborting command %p\n", scmd));
rtn = scsi_try_to_abort_cmd(sdev->host->hostt, scmd);
if (rtn == SUCCESS) {
- scmd->result |= DID_TIME_OUT << 16;
+ set_host_byte(scmd, DID_TIME_OUT);
if (scsi_host_eh_past_deadline(sdev->host)) {
SCSI_LOG_ERROR_RECOVERY(3,
scmd_printk(KERN_INFO, scmd,
@@ -167,7 +167,7 @@ scmd_eh_abort_handler(struct work_struct *work)
scmd_printk(KERN_WARNING, scmd,
"scmd %p terminate "
"aborted command\n", scmd));
- scmd->result |= DID_TIME_OUT << 16;
+ set_host_byte(scmd, DID_TIME_OUT);
scsi_finish_command(scmd);
}
}
@@ -291,7 +291,7 @@ enum blk_eh_timer_return scsi_times_out(struct request *req)
if (scsi_abort_command(scmd) == SUCCESS)
return BLK_EH_NOT_HANDLED;

- scmd->result |= DID_TIME_OUT << 16;
+ set_host_byte(scmd, DID_TIME_OUT);

if (unlikely(rtn == BLK_EH_NOT_HANDLED &&
!scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD)))
@@ -1776,7 +1776,7 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
break;
case DID_ABORT:
if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) {
- scmd->result |= DID_TIME_OUT << 16;
+ set_host_byte(scmd, DID_TIME_OUT);
return SUCCESS;
}
case DID_NO_CONNECT:
--
1.8.3.1


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