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[SCSI] scsi_error: add target reset handler 

The problem is that serveral drivers are sending a target reset from the
device reset handler, and if we have multiple devices a target reset gets
sent for each device when only one would be sufficient. And if we do a target
reset it affects all the commands on the target so the device reset handler
code only cleaning up one devices's commands makes programming the driver a
little more difficult than it should be.

This patch adds a target reset handler, which drivers can use to send
a target reset. If successful it cleans up the commands for a devices
accessed through that starget.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
hifive-unleashed-5.1
Mike Christie 2008-02-29 18:25:19 -06:00 committed by James Bottomley
parent f7441a791a
commit 30bd7df8ce
3 changed files with 106 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

122
drivers/scsi/scsi_error.c
View File

@ -524,6 +524,41 @@ static int scsi_try_bus_reset(struct scsi_cmnd *scmd)
return rtn;
}
static void __scsi_report_device_reset(struct scsi_device *sdev, void *data)
{
sdev->was_reset = 1;
sdev->expecting_cc_ua = 1;
}
/**
* scsi_try_target_reset - Ask host to perform a target reset
* @scmd: SCSI cmd used to send a target reset
*
* Notes:
* There is no timeout for this operation. if this operation is
* unreliable for a given host, then the host itself needs to put a
* timer on it, and set the host back to a consistent state prior to
* returning.
*/
static int scsi_try_target_reset(struct scsi_cmnd *scmd)
{
unsigned long flags;
int rtn;
if (!scmd->device->host->hostt->eh_target_reset_handler)
return FAILED;
rtn = scmd->device->host->hostt->eh_target_reset_handler(scmd);
if (rtn == SUCCESS) {
spin_lock_irqsave(scmd->device->host->host_lock, flags);
__starget_for_each_device(scsi_target(scmd->device), NULL,
__scsi_report_device_reset);
spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
}
return rtn;
}
/**
* scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
* @scmd: SCSI cmd used to send BDR
@ -542,11 +577,8 @@ static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd)
return FAILED;
rtn = scmd->device->host->hostt->eh_device_reset_handler(scmd);
if (rtn == SUCCESS) {
scmd->device->was_reset = 1;
scmd->device->expecting_cc_ua = 1;
}
if (rtn == SUCCESS)
__scsi_report_device_reset(scmd->device, NULL);
return rtn;
}
@ -584,8 +616,9 @@ static void scsi_abort_eh_cmnd(struct scsi_cmnd *scmd)
{
if (__scsi_try_to_abort_cmd(scmd) != SUCCESS)
if (scsi_try_bus_device_reset(scmd) != SUCCESS)
if (scsi_try_bus_reset(scmd) != SUCCESS)
scsi_try_host_reset(scmd);
if (scsi_try_target_reset(scmd) != SUCCESS)
if (scsi_try_bus_reset(scmd) != SUCCESS)
scsi_try_host_reset(scmd);
}
/**
@ -1059,6 +1092,56 @@ static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
return list_empty(work_q);
}
/**
* scsi_eh_target_reset - send target reset if needed
* @shost: scsi host being recovered.
* @work_q: &list_head for pending commands.
* @done_q: &list_head for processed commands.
*
* Notes:
* Try a target reset.
*/
static int scsi_eh_target_reset(struct Scsi_Host *shost,
struct list_head *work_q,
struct list_head *done_q)
{
struct scsi_cmnd *scmd, *tgtr_scmd, *next;
unsigned int id;
int rtn;
for (id = 0; id <= shost->max_id; id++) {
tgtr_scmd = NULL;
list_for_each_entry(scmd, work_q, eh_entry) {
if (id == scmd_id(scmd)) {
tgtr_scmd = scmd;
break;
}
}
if (!tgtr_scmd)
continue;
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending target reset "
"to target %d\n",
current->comm, id));
rtn = scsi_try_target_reset(tgtr_scmd);
if (rtn == SUCCESS) {
list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
if (id == scmd_id(scmd))
if (!scsi_device_online(scmd->device) ||
!scsi_eh_tur(tgtr_scmd))
scsi_eh_finish_cmd(scmd,
done_q);
}
} else
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Target reset"
" failed target: "
"%d\n",
current->comm, id));
}
return list_empty(work_q);
}
/**
* scsi_eh_bus_reset - send a bus reset
* @shost: &scsi host being recovered.
@ -1447,9 +1530,11 @@ void scsi_eh_ready_devs(struct Scsi_Host *shost,
{
if (!scsi_eh_stu(shost, work_q, done_q))
if (!scsi_eh_bus_device_reset(shost, work_q, done_q))
if (!scsi_eh_bus_reset(shost, work_q, done_q))
if (!scsi_eh_host_reset(work_q, done_q))
scsi_eh_offline_sdevs(work_q, done_q);
if (!scsi_eh_target_reset(shost, work_q, done_q))
if (!scsi_eh_bus_reset(shost, work_q, done_q))
if (!scsi_eh_host_reset(work_q, done_q))
scsi_eh_offline_sdevs(work_q,
done_q);
}
EXPORT_SYMBOL_GPL(scsi_eh_ready_devs);
@ -1619,10 +1704,8 @@ void scsi_report_bus_reset(struct Scsi_Host *shost, int channel)
struct scsi_device *sdev;
__shost_for_each_device(sdev, shost) {
if (channel == sdev_channel(sdev)) {
sdev->was_reset = 1;
sdev->expecting_cc_ua = 1;
}
if (channel == sdev_channel(sdev))
__scsi_report_device_reset(sdev, NULL);
}
}
EXPORT_SYMBOL(scsi_report_bus_reset);
@ -1655,10 +1738,8 @@ void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
__shost_for_each_device(sdev, shost) {
if (channel == sdev_channel(sdev) &&
target == sdev_id(sdev)) {
sdev->was_reset = 1;
sdev->expecting_cc_ua = 1;
}
target == sdev_id(sdev))
__scsi_report_device_reset(sdev, NULL);
}
}
EXPORT_SYMBOL(scsi_report_device_reset);
@ -1714,6 +1795,11 @@ scsi_reset_provider(struct scsi_device *dev, int flag)
if (rtn == SUCCESS)
break;
/* FALLTHROUGH */
case SCSI_TRY_RESET_TARGET:
rtn = scsi_try_target_reset(scmd);
if (rtn == SUCCESS)
break;
/* FALLTHROUGH */
case SCSI_TRY_RESET_BUS:
rtn = scsi_try_bus_reset(scmd);
if (rtn == SUCCESS)

1
include/scsi/scsi_eh.h
View File

@ -64,6 +64,7 @@ extern int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len,
#define SCSI_TRY_RESET_DEVICE 1
#define SCSI_TRY_RESET_BUS 2
#define SCSI_TRY_RESET_HOST 3
#define SCSI_TRY_RESET_TARGET 4
extern int scsi_reset_provider(struct scsi_device *, int);

1
include/scsi/scsi_host.h
View File

@ -172,6 +172,7 @@ struct scsi_host_template {
*/
int (* eh_abort_handler)(struct scsi_cmnd *);
int (* eh_device_reset_handler)(struct scsi_cmnd *);
int (* eh_target_reset_handler)(struct scsi_cmnd *);
int (* eh_bus_reset_handler)(struct scsi_cmnd *);
int (* eh_host_reset_handler)(struct scsi_cmnd *);