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authorHannes Reinecke <hare@suse.de>2017-02-17 09:02:45 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-03-12 06:37:26 +0100
commit33950b56d2c20d10e85a0ab339e5368e8d029a2b (patch)
tree13d3011e452a4e5cdaeb749a9109352937ce38d0
parent2dc9a859eb8918ff86efdd0f2a570bcb3d9d6973 (diff)
downloadlinux-linaro-stable-33950b56d2c20d10e85a0ab339e5368e8d029a2b.tar.gz
scsi: use 'scsi_device_from_queue()' for scsi_dh
commit 857de6e00778738dc3d61f75acbac35bdc48e533 upstream. 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. [mkp: dropped flags] Signed-off-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/scsi/scsi_dh.c22
-rw-r--r--drivers/scsi/scsi_lib.c23
-rw-r--r--include/scsi/scsi_device.h1
3 files changed, 28 insertions, 18 deletions
diff --git a/drivers/scsi/scsi_dh.c b/drivers/scsi/scsi_dh.c
index e7649ed3f667..4d655b568269 100644
--- a/drivers/scsi/scsi_dh.c
+++ b/drivers/scsi/scsi_dh.c
@@ -289,20 +289,6 @@ 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.
@@ -321,7 +307,7 @@ 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);
@@ -368,7 +354,7 @@ 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;
@@ -391,7 +377,7 @@ 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;
@@ -429,7 +415,7 @@ 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 8558e3886960..887045ae5d10 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2215,6 +2215,29 @@ 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;
+
+ 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;
+ if (!sdev || !get_device(&sdev->sdev_gendev))
+ sdev = NULL;
+
+ 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 4f6ba34cdee6..293b9a7f53bc 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -307,6 +307,7 @@ extern void scsi_remove_device(struct scsi_device *);
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 *,