The device handler needs to check if a given queue belongs to
a scsi device; only then does it make sense to attach a device
handler.
Signed-off-by: Hannes Reinecke <h...@suse.com>
---
drivers/scsi/scsi_dh.c | 22 ++++------------------
drivers/scsi/scsi_lib.c | 24 ++++++++++++++++++++++++
include/scsi/scsi_device.h | 1 +
3 files changed, 29 insertions(+), 18 deletions(-)
diff --git a/drivers/scsi/scsi_dh.c b/drivers/scsi/scsi_dh.c
index b8d3b97..84addee 100644
--- a/drivers/scsi/scsi_dh.c
+++ b/drivers/scsi/scsi_dh.c
@@ -219,20 +219,6 @@ int scsi_unregister_device_handler(struct
scsi_device_handler *scsi_dh)
}
EXPORT_SYMBOL_GPL(scsi_unregister_device_handler);
-static struct scsi_device *get_sdev_from_queue(struct request_queue *q)
-{
- struct scsi_device *sdev;
- unsigned long flags;
-
- spin_lock_irqsave(q->queue_lock, flags);
- sdev = q->queuedata;
- if (!sdev || !get_device(&sdev->sdev_gendev))
- sdev = NULL;
- spin_unlock_irqrestore(q->queue_lock, flags);
-
- return sdev;
-}
-
/*
* scsi_dh_activate - activate the path associated with the scsi_device
* corresponding to the given request queue.
@@ -251,7 +237,7 @@ int scsi_dh_activate(struct request_queue *q,
activate_complete fn, void *data)
struct scsi_device *sdev;
int err = SCSI_DH_NOSYS;
- sdev = get_sdev_from_queue(q);
+ sdev = scsi_device_from_queue(q);
if (!sdev) {
if (fn)
fn(data, err);
@@ -298,7 +284,7 @@ int scsi_dh_set_params(struct request_queue *q, const char
*params)
struct scsi_device *sdev;
int err = -SCSI_DH_NOSYS;
- sdev = get_sdev_from_queue(q);
+ sdev = scsi_device_from_queue(q);
if (!sdev)
return err;
@@ -321,7 +307,7 @@ int scsi_dh_attach(struct request_queue *q, const char
*name)
struct scsi_device_handler *scsi_dh;
int err = 0;
- sdev = get_sdev_from_queue(q);
+ sdev = scsi_device_from_queue(q);
if (!sdev)
return -ENODEV;
@@ -359,7 +345,7 @@ const char *scsi_dh_attached_handler_name(struct
request_queue *q, gfp_t gfp)
struct scsi_device *sdev;
const char *handler_name = NULL;
- sdev = get_sdev_from_queue(q);
+ sdev = scsi_device_from_queue(q);
if (!sdev)
return NULL;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 9d6aed5..9c732d3 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2145,6 +2145,30 @@ void scsi_mq_destroy_tags(struct Scsi_Host *shost)
blk_mq_free_tag_set(&shost->tag_set);
}
+/**
+ * scsi_device_from_queue - return sdev associated with a request_queue
+ * @q: The request queue to return the sdev from
+ *
+ * Return the sdev associated with a request queue or NULL if the
+ * request_queue does not reference a SCSI device.
+ */
+struct scsi_device *scsi_device_from_queue(struct request_queue *q)
+{
+ struct scsi_device *sdev = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ if (q->mq_ops) {
+ if (q->mq_ops == &scsi_mq_ops)
+ sdev = q->queuedata;
+ } else if (q->request_fn == scsi_request_fn)
+ sdev = q->queuedata;
+ spin_unlock_irqrestore(q->queue_lock, flags);
+
+ return sdev;
+}
+EXPORT_SYMBOL_GPL(scsi_device_from_queue);
+
/*
* Function: scsi_block_requests()
*
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 8990e58..be41c76 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -315,6 +315,7 @@ extern int scsi_add_device(struct Scsi_Host *host, uint
channel,
extern int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh);
void scsi_attach_vpd(struct scsi_device *sdev);
+extern struct scsi_device *scsi_device_from_queue(struct request_queue *q);
extern int scsi_device_get(struct scsi_device *);
extern void scsi_device_put(struct scsi_device *);
extern struct scsi_device *scsi_device_lookup(struct Scsi_Host *,
--
1.8.5.6
