From: Mike Christie <michaelc@xxxxxxxxxxx>
Drivers like qla4xxx and bnx2i (and it looks like some fcp drivers too),
want to be able to send a lun reset in the eh device handler and then a
target reset in some other handler. The old linux-iscsi driver, which did
the host per session like open-iscsi did the target reset in the host reset,
because the scsi command accounting that scsi_error.c does worked out
nicely for software iscsi, but does not work for hardware iscsi well.
This patch adds a eh_target_reset_handler any driver can use to send
a target reset.
The next patch will hook qla4xxx into it, and patches for iscsi_tcp/iser
and bnx2i will follow later when bnx2i is closer to getting merged.
Signed-off-by: Mike Christie <michaelc@xxxxxxxxxxx>
---
drivers/scsi/scsi_error.c | 121 ++++++++++++++++++++++++++++++++++++++-------
include/scsi/scsi_eh.h | 1 +
include/scsi/scsi_host.h | 1 +
3 files changed, 105 insertions(+), 18 deletions(-)
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 169bc59..fb1f5bc 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -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);
}
/**
@@ -1064,6 +1097,56 @@ static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
}
/**
+ * 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.
* @work_q: &list_head for pending commands.
@@ -1451,9 +1534,11 @@ 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);
@@ -1623,10 +1708,8 @@ 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);
@@ -1659,10 +1742,8 @@ 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);
@@ -1724,6 +1805,10 @@ 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;
case SCSI_TRY_RESET_HOST:
rtn = scsi_try_host_reset(scmd);
break;
diff --git a/include/scsi/scsi_eh.h b/include/scsi/scsi_eh.h
index d21b891..8bfdee8 100644
--- a/include/scsi/scsi_eh.h
+++ b/include/scsi/scsi_eh.h
@@ -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);
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 0fd4746..8bb0644 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -171,6 +171,7 @@ 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 *);
--
1.5.1.2
-
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