From: Mike Christie <michaelc@xxxxxxxxxxx>
This patch adds a scsi handler for REQ_LB_OP_TRANSITION commands.
Signed-off-by: Mike Christie <michaelc@xxxxxxxxxxx>
---
drivers/scsi/Kconfig | 5 ++
drivers/scsi/scsi_error.c | 10 ++++
drivers/scsi/scsi_lib.c | 113 +++++++++++++++++++++++++++++++++++++++++++-
include/scsi/scsi_cmnd.h | 1
include/scsi/scsi_device.h | 14 +++++
5 files changed, 141 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index aac9cd9..e4372da 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -285,6 +285,11 @@ source "drivers/scsi/libsas/Kconfig"
endmenu
+menu "SCSI Device Info Drivers"
+ depends on SCSI
+
+endmenu
+
menu "SCSI low-level drivers"
depends on SCSI!=n
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 9adb64a..99e526d 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -297,6 +297,7 @@ #endif
**/
static int scsi_check_sense(struct scsi_cmnd *scmd)
{
+ struct scsi_device *sdev = scmd->device;
struct scsi_sense_hdr sshdr;
if (! scsi_command_normalize_sense(scmd, &sshdr))
@@ -305,6 +306,15 @@ static int scsi_check_sense(struct scsi_
if (scsi_sense_is_deferred(&sshdr))
return NEEDS_RETRY;
+ if (sdev->sdevt && sdev->sdevt->check_sense) {
+ int rc;
+
+ rc = sdev->sdevt->check_sense(&sshdr);
+ if (rc)
+ return rc;
+ /* hw module does not care. Drop down to default handling */
+ }
+
/*
* Previous logic looked for FILEMARK, EOM or ILI which are
* mainly associated with tapes and returned SUCCESS.
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 70454b4..e96a9a0 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1075,6 +1075,37 @@ static struct scsi_cmnd *scsi_get_cmd_fr
return cmd;
}
+static int scsi_setup_blk_linux_cmnd(struct scsi_device *sdev,
+ struct request *rq)
+{
+ if (!get_device(&sdev->sdev_gendev)) {
+ rq->errors = BLKERR_DEV_OFFLINED;
+ goto kill;
+ }
+
+ switch (rq->cmd[0]) {
+ case REQ_LB_OP_TRANSITION:
+ if (!sdev->sdevt || !sdev->sdevt->transition) {
+ /* set REQ_LB_OP_TRANSITION specific error */
+ rq->errors = BLKERR_NOSYS;
+ goto kill;
+ }
+ if (!try_module_get(sdev->sdevt->module)) {
+ rq->errors = BLKERR_DEV_OFFLINED;
+ goto kill;
+ }
+
+ break;
+ default:
+ rq->errors = BLKERR_INVALID_IO;
+ goto kill;
+ }
+ return BLKPREP_OK;
+
+kill:
+ return BLKPREP_KILL;
+}
+
static void scsi_blk_pc_done(struct scsi_cmnd *cmd)
{
BUG_ON(!blk_pc_request(cmd->request));
@@ -1233,6 +1264,8 @@ static int scsi_prep_fn(struct request_q
case REQ_TYPE_FS:
ret = scsi_setup_fs_cmnd(sdev, req);
break;
+ case REQ_TYPE_LINUX_BLOCK:
+ return scsi_setup_blk_linux_cmnd(sdev, req);
default:
/*
* All other command types are not supported.
@@ -1376,9 +1409,24 @@ static void scsi_kill_request(struct req
static void scsi_softirq_done(struct request *rq)
{
struct scsi_cmnd *cmd = rq->completion_data;
- unsigned long wait_for = (cmd->allowed + 1) * cmd->timeout_per_command;
+ struct request_queue *q;
+ unsigned long wait_for, flags;
int disposition;
+ if (blk_linux_request(rq)) {
+ q = rq->q;
+ spin_lock_irqsave(q->queue_lock, flags);
+ /*
+ * we always return 1 and the caller should
+ * check rq->errors for the complete status
+ */
+ end_that_request_last(rq, 1);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+ return;
+ }
+
+
+ wait_for = (cmd->allowed + 1) * cmd->timeout_per_command;
INIT_LIST_HEAD(&cmd->eh_entry);
disposition = scsi_decide_disposition(cmd);
@@ -1408,6 +1456,51 @@ static void scsi_softirq_done(struct req
}
}
+/**
+ * scsi_blk_linux_cmd_done - Complete a REQ_TYPE_LINUX_BLOCK request.
+ * @req: REQ_TYPE_LINUX_BLOCK request being processed
+ * @err: return value
+ *
+ * This function should be called by the REQ_TYPE_LINUX_BLOCK handler
+ * to return the request to its caller. This function queues the
+ * the completion to the blk softirq so the queue lock does not have
+ * to be held here.
+ */
+void scsi_blk_linux_cmd_done(struct request *rq, int err)
+{
+ struct scsi_device *sdev = rq->q->queuedata;
+
+ switch (rq->cmd[0]) {
+ case REQ_LB_OP_TRANSITION:
+ module_put(sdev->sdevt->module);
+ break;
+ }
+
+ put_device(&sdev->sdev_gendev);
+ rq->errors = err;
+ rq->completion_data = NULL;
+ blk_complete_request(rq);
+}
+EXPORT_SYMBOL_GPL(scsi_blk_linux_cmd_done);
+
+static void scsi_execute_blk_linux_cmd(struct request *rq)
+{
+ struct request_queue *q = rq->q;
+ struct scsi_device *sdev = q->queuedata;
+
+ switch (rq->cmd[0]) {
+ case REQ_LB_OP_TRANSITION:
+ spin_unlock_irq(q->queue_lock);
+ sdev->sdevt->transition(rq);
+ spin_lock_irq(q->queue_lock);
+ break;
+ default:
+ /* should have checked in scsi_prep_fn already */
+ BUG();
+ }
+}
+
+
/*
* Function: scsi_request_fn()
*
@@ -1450,7 +1543,23 @@ static void scsi_request_fn(struct reque
* accept it.
*/
req = elv_next_request(q);
- if (!req || !scsi_dev_queue_ready(q, sdev))
+ if (!req)
+ break;
+
+ /*
+ * We do not account for linux blk req in the device
+ * or host busy accounting because it is not necessarily
+ * a scsi command that is sent to some object. The lower
+ * level can translate it into a request/scsi_cmnd, if
+ * necessary, and then queue that up using REQ_TYPE_BLOCK_PC.
+ */
+ if (blk_linux_request(req)) {
+ blkdev_dequeue_request(req);
+ scsi_execute_blk_linux_cmd(req);
+ continue;
+ }
+
+ if (!scsi_dev_queue_ready(q, sdev))
break;
if (unlikely(!scsi_device_online(sdev))) {
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 53e1705..5344b44 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -127,6 +127,7 @@ extern void __scsi_put_command(struct Sc
extern void scsi_io_completion(struct scsi_cmnd *, unsigned int);
extern void scsi_finish_command(struct scsi_cmnd *cmd);
extern void scsi_req_abort_cmd(struct scsi_cmnd *cmd);
+extern void scsi_blk_linux_cmd_done(struct request *req, int err);
extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
size_t *offset, size_t *len);
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 2f3c5b8..1db6808 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -9,6 +9,7 @@ #include <linux/blkdev.h>
#include <asm/atomic.h>
struct request_queue;
+struct request;
struct scsi_cmnd;
struct scsi_lun;
struct scsi_sense_hdr;
@@ -143,9 +144,22 @@ #define SCSI_DEFAULT_DEVICE_BLOCKED 3
struct execute_work ew; /* used to get process context on put */
+ struct scsi_device_template *sdevt;
+ void *sdevt_data;
enum scsi_device_state sdev_state;
unsigned long sdev_data[0];
} __attribute__((aligned(sizeof(unsigned long))));
+
+#define SCSI_MAX_SDEV_TEMPLATE_NAME 16
+
+struct scsi_device_template {
+ struct module *module;
+ const char *name;
+
+ int (* check_sense)(struct scsi_sense_hdr *);
+ void (* transition)(struct request *);
+};
+
#define to_scsi_device(d) \
container_of(d, struct scsi_device, sdev_gendev)
#define class_to_sdev(d) \
--
1.4.1.1
--
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