From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: [PATCHv2] scsi: use 'scsi_device_from_queue()' for scsi_dh Date: Thu, 16 Feb 2017 16:12:23 +0100 Message-ID: <1487257943-72264-1-git-send-email-hare@suse.de> Return-path: Received: from mx2.suse.de ([195.135.220.15]:37693 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932218AbdBPPM2 (ORCPT ); Thu, 16 Feb 2017 10:12:28 -0500 Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: "Martin K. Petersen" Cc: Christoph Hellwig , Keith Busch , linux-scsi@vger.kernel.org, Bart van Assche , Hannes Reinecke , Hannes Reinecke 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 --- drivers/scsi/scsi_dh.c | 22 ++++------------------ drivers/scsi/scsi_lib.c | 26 ++++++++++++++++++++++++++ include/scsi/scsi_device.h | 1 + 3 files changed, 31 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..1a81ef9 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -2145,6 +2145,32 @@ 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; + if (!sdev || !get_device(&sdev->sdev_gendev)) + sdev = NULL; + 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