From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753278AbbJNMWs (ORCPT ); Wed, 14 Oct 2015 08:22:48 -0400 Received: from mx2.suse.de ([195.135.220.15]:46843 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751919AbbJNMWp (ORCPT ); Wed, 14 Oct 2015 08:22:45 -0400 Message-ID: <1444825362.19542.3.camel@suse.de> Subject: Re: [PATCHv4 1/1] SCSI: hosts: update to use ida_simple for host_no management From: Johannes Thumshirn To: Lee Duncan , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Cc: James Bottomley , Tejun Heo , Hannes Reinecke , Christoph Hellwig Date: Wed, 14 Oct 2015 14:22:42 +0200 In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.16.5 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2015-10-07 at 16:51 -0700, Lee Duncan wrote: > Update the SCSI hosts module to use the ida_simple*() routines > to manage its host_no index instead of an ATOMIC integer. This > means that the SCSI host number will now be reclaimable. > > Signed-off-by: Lee Duncan > --- > drivers/scsi/hosts.c | 22 ++++++++++++++-------- > 1 file changed, 14 insertions(+), 8 deletions(-) > > diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c > index 8bb173e01084..b6a5ffa886b7 100644 > --- a/drivers/scsi/hosts.c > +++ b/drivers/scsi/hosts.c > @@ -33,7 +33,7 @@ > #include > #include > #include > - > +#include > #include > #include > #include > @@ -42,7 +42,7 @@ > #include "scsi_logging.h" > > > -static atomic_t scsi_host_next_hn = ATOMIC_INIT(0); /* > host_no for next new host */ > +static DEFINE_IDA(host_index_ida); > > > static void scsi_host_cls_release(struct device *dev) > @@ -337,6 +337,8 @@ static void scsi_host_dev_release(struct device > *dev) > > kfree(shost->shost_data); > > + ida_simple_remove(&host_index_ida, shost->host_no); > + > if (parent) > put_device(parent); > kfree(shost); > @@ -370,6 +372,7 @@ struct Scsi_Host *scsi_host_alloc(struct > scsi_host_template *sht, int privsize) > { > struct Scsi_Host *shost; > gfp_t gfp_mask = GFP_KERNEL; > + int index; > > if (sht->unchecked_isa_dma && privsize) > gfp_mask |= __GFP_DMA; > @@ -388,11 +391,11 @@ struct Scsi_Host *scsi_host_alloc(struct > scsi_host_template *sht, int privsize) > init_waitqueue_head(&shost->host_wait); > mutex_init(&shost->scan_mutex); > > - /* > - * subtract one because we increment first then return, but > we need to > - * know what the next host number was before increment > - */ > - shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1; > + index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL); > + if (index < 0) > + goto fail_kfree; > + shost->host_no = index; > + > shost->dma_channel = 0xff; > > /* These three are default values which can be overridden */ > @@ -477,7 +480,7 @@ struct Scsi_Host *scsi_host_alloc(struct > scsi_host_template *sht, int privsize) > shost_printk(KERN_WARNING, shost, > "error handler thread failed to spawn, error > = %ld\n", > PTR_ERR(shost->ehandler)); > - goto fail_kfree; > + goto fail_index_remove; > } > > shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d", > @@ -493,6 +496,8 @@ struct Scsi_Host *scsi_host_alloc(struct > scsi_host_template *sht, int privsize) > > fail_kthread: > kthread_stop(shost->ehandler); > + fail_index_remove: > + ida_simple_remove(&host_index_ida, shost->host_no); > fail_kfree: > kfree(shost); > return NULL; > @@ -588,6 +593,7 @@ int scsi_init_hosts(void) > void scsi_exit_hosts(void) > { > class_unregister(&shost_class); > + ida_destroy(&host_index_ida); > } > > int scsi_is_host_device(const struct device *dev) Reviewed-by: Johannes Thumshirn