From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: Re: [PATCH v4 2/5] scsi_dh: add scsi_dh_attached_handler_name Date: Thu, 17 May 2012 17:23:34 -0400 Message-ID: <20120517212333.GA5312@redhat.com> References: <1336612366-30794-1-git-send-email-snitzer@redhat.com> <20120510213112.GA7374@redhat.com> <1337289153.2825.9.camel@chandra-lucid.austin.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mx1.redhat.com ([209.132.183.28]:20543 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760151Ab2EQVXp (ORCPT ); Thu, 17 May 2012 17:23:45 -0400 Content-Disposition: inline In-Reply-To: <1337289153.2825.9.camel@chandra-lucid.austin.ibm.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Chandra Seetharaman Cc: linux-scsi@vger.kernel.org, agk@redhat.com, hare@suse.de, babu.moger@netapp.com, dm-devel@redhat.com On Thu, May 17 2012 at 5:12pm -0400, Chandra Seetharaman wrote: > > +/* > > + * scsi_dh_attached_handler_name - Get attached device handler's name > > + * @q - Request queue that is associated with the scsi_device > > + * that may have a device handler attached > > + * @gfp - the GFP mask used in the kmalloc() call when allocating memory > > + * > > + * Returns name of attached handler, NULL if no handler is attached. > > + * Caller must take care to free the returned string. > > + */ > > +const char *scsi_dh_attached_handler_name(struct request_queue *q, gfp_t gfp) > > +{ > > + unsigned long flags; > > + struct scsi_device *sdev; > > + const char *handler_name = NULL; > > + > > + 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); > > + > > + if (!sdev) > > put_device() missing here. Not that I can see. If sdev is NULL then get_device never succeeded. (same pattern is used in scsi_dh_detach) > > + return NULL; > > + > > + if (sdev->scsi_dh_data) > > + handler_name = kstrdup(sdev->scsi_dh_data->scsi_dh->name, gfp); > > + > > + put_device(&sdev->sdev_gendev); > > + return handler_name; > > +} > > +EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name); > > + > > static struct notifier_block scsi_dh_nb = { > > .notifier_call = scsi_dh_notifier > > }; > > Index: linux-2.6/include/scsi/scsi_dh.h > > =================================================================== > > --- linux-2.6.orig/include/scsi/scsi_dh.h > > +++ linux-2.6/include/scsi/scsi_dh.h > > @@ -60,6 +60,7 @@ extern int scsi_dh_activate(struct reque > > extern int scsi_dh_handler_exist(const char *); > > extern int scsi_dh_attach(struct request_queue *, const char *); > > extern void scsi_dh_detach(struct request_queue *); > > +extern const char *scsi_dh_attached_handler_name(struct request_queue *, gfp_t); > > extern int scsi_dh_set_params(struct request_queue *, const char *); > > #else > > static inline int scsi_dh_activate(struct request_queue *req, > > @@ -80,6 +81,11 @@ static inline void scsi_dh_detach(struct > > { > > return; > > } > > +static inline const char *scsi_dh_attached_handler_name(struct request_queue *q, > > + gfp_t gfp) > > +{ > > + return NULL; > > +} > > static inline int scsi_dh_set_params(struct request_queue *req, const char *params) > > { > > return -SCSI_DH_NOSYS; > > > >