From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Duncan Subject: Re: [PATCH] Update scsi host to use ida for host number Date: Tue, 1 Sep 2015 10:26:32 -0700 Message-ID: <55E5DFC8.2060300@suse.com> References: <1441052890-3600-1-git-send-email-leeman.duncan@gmail.com> <55E56068.2090605@dev.mellanox.co.il> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: Received: from victor.provo.novell.com ([137.65.250.26]:52868 "EHLO prv3-mh.provo.novell.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751901AbbIAR0l (ORCPT ); Tue, 1 Sep 2015 13:26:41 -0400 In-Reply-To: <55E56068.2090605@dev.mellanox.co.il> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Sagi Grimberg , linux-scsi@vger.kernel.org Cc: hare@suse.com, JBottomley@Parallels.com, Johannes Thumshirn On 09/01/2015 01:23 AM, Sagi Grimberg wrote: > On 8/31/2015 11:28 PM, leeman.duncan@gmail.com wrote: >> From: Lee Duncan >> >> Each Scsi_host instance gets a host number starting >> at 0, but this is implemented with an atomic integer, >> and rollover doesn't seem to have been considered. >> Another side-effect of this design is that scsi host >> numbers used by iscsi are never reused, thereby making >> rollover more likely. This patch converts Scsi_host >> instances to use ida to manage their instance >> numbers. >> >> This also means that host instance numbers will be >> reused, when available. >> >> Signed-off-by: Lee Duncan >> --- >> drivers/scsi/hosts.c | 43 +++++++++++++++++++++++++++++++++++-------- >> 1 file changed, 35 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c >> index 8bb173e01084..dade75478541 100644 >> --- a/drivers/scsi/hosts.c >> +++ b/drivers/scsi/hosts.c >> @@ -33,7 +33,7 @@ >> #include >> #include >> #include >> - >> +#include >> #include >> #include >> #include >> @@ -42,7 +42,8 @@ >> #include "scsi_logging.h" >> >> >> -static atomic_t scsi_host_next_hn = ATOMIC_INIT(0); /* host_no for >> next new host */ >> +static DEFINE_SPINLOCK(host_index_lock); >> +static DEFINE_IDA(host_index_ida); >> >> >> static void scsi_host_cls_release(struct device *dev) >> @@ -337,6 +338,10 @@ static void scsi_host_dev_release(struct device >> *dev) >> >> kfree(shost->shost_data); >> >> + spin_lock(&host_index_lock); >> + ida_remove(&host_index_ida, shost->host_no); >> + spin_unlock(&host_index_lock); > > Why not get it in a symmetrical host_put_index() Seems like a reasonable suggestion. Since it's only 3 statements, I'll make it an inline. I will resubmit the patch, adding the two reviewed-by lines from Hannes and Johannes, since the code will essentially be the same. -- Lee Duncan SUSE Labs