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[SCSI] libsas: prevent double completion of scmds from eh

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We invoke task->task_done() to free the task in the eh case, but at this
point we are prepared for scsi_eh_flush_done_q() to finish off the scmd.

Introduce sas_end_task() to capture the final response status from the
lldd and free the task.

Also take the opportunity to kill this warning.
drivers/scsi/libsas/sas_scsi_host.c: In function ‘sas_end_task’:
drivers/scsi/libsas/sas_scsi_host.c:102:3: warning: case value ‘2’ not in enumerated type ‘enum exec_status’ [-Wswitch]

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
This commit is contained in:
Dan Williams 2011-12-06 23:24:42 -08:00 committed by James Bottomley
parent 3dff5721e4
commit a3a142524a
2 changed files with 37 additions and 29 deletions
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61
drivers/scsi/libsas/sas_scsi_host.c
View File

@ -49,27 +49,12 @@
#include <linux/scatterlist.h>
#include <linux/libata.h>
/* ---------- SCSI Host glue ---------- */
static void sas_scsi_task_done(struct sas_task *task)
/* record final status and free the task */
static void sas_end_task(struct scsi_cmnd *sc, struct sas_task *task)
{
struct task_status_struct *ts = &task->task_status;
struct scsi_cmnd *sc = task->uldd_task;
int hs = 0, stat = 0;
if (unlikely(task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
/* Aborted tasks will be completed by the error handler */
SAS_DPRINTK("task done but aborted\n");
return;
}
if (unlikely(!sc)) {
SAS_DPRINTK("task_done called with non existing SCSI cmnd!\n");
list_del_init(&task->list);
sas_free_task(task);
return;
}
if (ts->resp == SAS_TASK_UNDELIVERED) {
/* transport error */
hs = DID_NO_CONNECT;
@ -124,10 +109,32 @@ static void sas_scsi_task_done(struct sas_task *task)
break;
}
}
ASSIGN_SAS_TASK(sc, NULL);
sc->result = (hs << 16) | stat;
ASSIGN_SAS_TASK(sc, NULL);
list_del_init(&task->list);
sas_free_task(task);
}
static void sas_scsi_task_done(struct sas_task *task)
{
struct scsi_cmnd *sc = task->uldd_task;
if (unlikely(task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
/* Aborted tasks will be completed by the error handler */
SAS_DPRINTK("task done but aborted\n");
return;
}
if (unlikely(!sc)) {
SAS_DPRINTK("task_done called with non existing SCSI cmnd!\n");
list_del_init(&task->list);
sas_free_task(task);
return;
}
ASSIGN_SAS_TASK(sc, NULL);
sas_end_task(sc, task);
sc->scsi_done(sc);
}
@ -236,18 +243,16 @@ static void sas_eh_finish_cmd(struct scsi_cmnd *cmd)
struct sas_task *task = TO_SAS_TASK(cmd);
struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(cmd->device->host);
/* remove the aborted task flag to allow the task to be
* completed now. At this point, we only get called following
* an actual abort of the task, so we should be guaranteed not
* to be racing with any completions from the LLD (hence we
* don't need the task state lock to clear the flag) */
task->task_state_flags &= ~SAS_TASK_STATE_ABORTED;
/* Now call task_done. However, task will be free'd after
* this */
task->task_done(task);
/* At this point, we only get called following an actual abort
* of the task, so we should be guaranteed not to be racing with
* any completions from the LLD. Task is freed after this.
*/
sas_end_task(cmd, task);
/* now finish the command and move it on to the error
* handler done list, this also takes it off the
* error handler pending list */
* error handler pending list.
*/
scsi_eh_finish_cmd(cmd, &sas_ha->eh_done_q);
}

5
include/scsi/libsas.h
View File

@ -452,7 +452,10 @@ enum service_response {
};
enum exec_status {
/* The SAM_STAT_.. codes fit in the lower 6 bits */
/* The SAM_STAT_.. codes fit in the lower 6 bits, alias some of
* them here to silence 'case value not in enumerated type' warnings
*/
__SAM_STAT_CHECK_CONDITION = SAM_STAT_CHECK_CONDITION,
SAS_DEV_NO_RESPONSE = 0x80,
SAS_DATA_UNDERRUN,