From patchwork Wed Oct 14 13:50:06 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Thumshirn X-Patchwork-Id: 7395701 Return-Path: X-Original-To: patchwork-linux-scsi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id A8C97BEEA4 for ; Wed, 14 Oct 2015 13:50:24 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 92C6E206B0 for ; Wed, 14 Oct 2015 13:50:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C110207F6 for ; Wed, 14 Oct 2015 13:50:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753772AbbJNNuT (ORCPT ); Wed, 14 Oct 2015 09:50:19 -0400 Received: from mx2.suse.de ([195.135.220.15]:55372 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753715AbbJNNuP (ORCPT ); Wed, 14 Oct 2015 09:50:15 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 94BFEAD52; Wed, 14 Oct 2015 13:50:12 +0000 (UTC) From: Johannes Thumshirn To: "James E.J. Bottomley" , Christoph Hellwig , Hannes Reinecke Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, Johannes Thumshirn Subject: [PATCH 1/3] SCSI: Introduce device_lock and target_lock in Scsi_Host Date: Wed, 14 Oct 2015 15:50:06 +0200 Message-Id: X-Mailer: git-send-email 1.8.5.6 In-Reply-To: References: In-Reply-To: References: Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Introduce target_lock and device_lock to untangle the __devices and __targets lists from the host_lock. Signed-off-by: Johannes Thumshirn --- drivers/scsi/53c700.c | 3 +++ drivers/scsi/hosts.c | 2 ++ drivers/scsi/scsi.c | 8 ++++---- drivers/scsi/scsi_scan.c | 10 +++++----- drivers/scsi/scsi_sysfs.c | 18 ++++++++---------- include/scsi/scsi_host.h | 2 ++ 6 files changed, 24 insertions(+), 19 deletions(-) diff --git a/drivers/scsi/53c700.c b/drivers/scsi/53c700.c index a209c34..e2b4d04 100644 --- a/drivers/scsi/53c700.c +++ b/drivers/scsi/53c700.c @@ -1093,6 +1093,7 @@ process_script_interrupt(__u32 dsps, __u32 dsp, struct scsi_cmnd *SCp, struct NCR_700_command_slot *slot; __u8 reselection_id = hostdata->reselection_id; struct scsi_device *SDp; + unsigned long flags; lun = hostdata->msgin[0] & 0x1f; @@ -1100,7 +1101,9 @@ process_script_interrupt(__u32 dsps, __u32 dsp, struct scsi_cmnd *SCp, DEBUG(("scsi%d: (%d:%d) RESELECTED!\n", host->host_no, reselection_id, lun)); /* clear the reselection indicator */ + spin_lock_irqsave(host->device_lock, flags); SDp = __scsi_device_lookup(host, 0, reselection_id, lun); + spin_unlock_irqrestore(host->device_lock, flags); if(unlikely(SDp == NULL)) { printk(KERN_ERR "scsi%d: (%d:%d) HAS NO device\n", host->host_no, reselection_id, lun); diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 8bb173e..6855434 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -380,6 +380,8 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) shost->host_lock = &shost->default_lock; spin_lock_init(shost->host_lock); + spin_lock_init(&shost->device_lock); + spin_lock_init(&shost->target_lock); shost->shost_state = SHOST_CREATED; INIT_LIST_HEAD(&shost->__devices); INIT_LIST_HEAD(&shost->__targets); diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index 207d6a7..0e1046a 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -970,7 +970,7 @@ struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost, struct scsi_device *next = NULL; unsigned long flags; - spin_lock_irqsave(shost->host_lock, flags); + spin_lock_irqsave(&shost->device_lock, flags); while (list->next != &shost->__devices) { next = list_entry(list->next, struct scsi_device, siblings); /* skip devices that we can't get a reference to */ @@ -979,7 +979,7 @@ struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost, next = NULL; list = list->next; } - spin_unlock_irqrestore(shost->host_lock, flags); + spin_unlock_irqrestore(&shost->device_lock, flags); if (prev) scsi_device_put(prev); @@ -1144,11 +1144,11 @@ struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost, struct scsi_device *sdev; unsigned long flags; - spin_lock_irqsave(shost->host_lock, flags); + spin_lock_irqsave(&shost->device_lock, flags); sdev = __scsi_device_lookup(shost, channel, id, lun); if (sdev && scsi_device_get(sdev)) sdev = NULL; - spin_unlock_irqrestore(shost->host_lock, flags); + spin_unlock_irqrestore(&shost->device_lock, flags); return sdev; } diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index f9f3f82..ac68531 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -441,14 +441,14 @@ static struct scsi_target *scsi_alloc_target(struct device *parent, starget->scsi_level = SCSI_2; starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED; retry: - spin_lock_irqsave(shost->host_lock, flags); + spin_lock_irqsave(&shost->target_lock, flags); found_target = __scsi_find_target(parent, channel, id); if (found_target) goto found; list_add_tail(&starget->siblings, &shost->__targets); - spin_unlock_irqrestore(shost->host_lock, flags); + spin_unlock_irqrestore(&shost->target_lock, flags); /* allocate and add */ transport_setup_device(dev); if (shost->hostt->target_alloc) { @@ -1854,15 +1854,15 @@ void scsi_forget_host(struct Scsi_Host *shost) unsigned long flags; restart: - spin_lock_irqsave(shost->host_lock, flags); + spin_lock_irqsave(&shost->device_lock, flags); list_for_each_entry(sdev, &shost->__devices, siblings) { if (sdev->sdev_state == SDEV_DEL) continue; - spin_unlock_irqrestore(shost->host_lock, flags); + spin_unlock_irqrestore(&shost->device_lock, flags); __scsi_remove_device(sdev); goto restart; } - spin_unlock_irqrestore(shost->host_lock, flags); + spin_unlock_irqrestore(&shost->device_lock, flags); } /** diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index b333389..d7afea9 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -1131,20 +1131,18 @@ static void __scsi_remove_target(struct scsi_target *starget) unsigned long flags; struct scsi_device *sdev; - spin_lock_irqsave(shost->host_lock, flags); + spin_lock_irqsave(&shost->device_lock, flags); restart: list_for_each_entry(sdev, &shost->__devices, siblings) { if (sdev->channel != starget->channel || sdev->id != starget->id || scsi_device_get(sdev)) continue; - spin_unlock_irqrestore(shost->host_lock, flags); scsi_remove_device(sdev); scsi_device_put(sdev); - spin_lock_irqsave(shost->host_lock, flags); goto restart; } - spin_unlock_irqrestore(shost->host_lock, flags); + spin_unlock_irqrestore(&shost->device_lock, flags); } /** @@ -1164,22 +1162,22 @@ void scsi_remove_target(struct device *dev) /* remove targets being careful to lookup next entry before * deleting the last */ - spin_lock_irqsave(shost->host_lock, flags); + spin_lock_irqsave(&shost->target_lock, flags); list_for_each_entry(starget, &shost->__targets, siblings) { if (starget->state == STARGET_DEL) continue; if (starget->dev.parent == dev || &starget->dev == dev) { /* assuming new targets arrive at the end */ kref_get(&starget->reap_ref); - spin_unlock_irqrestore(shost->host_lock, flags); + spin_unlock_irqrestore(&shost->target_lock, flags); if (last) scsi_target_reap(last); last = starget; __scsi_remove_target(starget); - spin_lock_irqsave(shost->host_lock, flags); + spin_lock_irqsave(&shost->target_lock, flags); } } - spin_unlock_irqrestore(shost->host_lock, flags); + spin_unlock_irqrestore(&shost->target_lock, flags); if (last) scsi_target_reap(last); @@ -1262,10 +1260,10 @@ void scsi_sysfs_device_initialize(struct scsi_device *sdev) sdev->lun_in_cdb = 1; transport_setup_device(&sdev->sdev_gendev); - spin_lock_irqsave(shost->host_lock, flags); + spin_lock_irqsave(&shost->device_lock, flags); list_add_tail(&sdev->same_target_siblings, &starget->devices); list_add_tail(&sdev->siblings, &shost->__devices); - spin_unlock_irqrestore(shost->host_lock, flags); + spin_unlock_irqrestore(&shost->device_lock, flags); /* * device can now only be removed via __scsi_remove_device() so hold * the target. Target will be held in CREATED state until something diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index e113c75..764020a 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -558,6 +558,8 @@ struct Scsi_Host { spinlock_t default_lock; spinlock_t *host_lock; + spinlock_t device_lock; /* protects the __devices list */ + spinlock_t target_lock; /* protects the __targets list */ struct mutex scan_mutex;/* serialize scanning activity */