From patchwork Thu Jul 28 22:18:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bart Van Assche X-Patchwork-Id: 594305 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AC352C04A68 for ; Thu, 28 Jul 2022 22:19:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231925AbiG1WTa (ORCPT ); Thu, 28 Jul 2022 18:19:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56122 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232478AbiG1WTM (ORCPT ); Thu, 28 Jul 2022 18:19:12 -0400 Received: from mail-pj1-f46.google.com (mail-pj1-f46.google.com [209.85.216.46]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 737887969C for ; Thu, 28 Jul 2022 15:19:08 -0700 (PDT) Received: by mail-pj1-f46.google.com with SMTP id d65-20020a17090a6f4700b001f303a97b14so3547203pjk.1 for ; Thu, 28 Jul 2022 15:19:08 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=PK7GhXluDeO7vB7OgT+f4kVleUWpGV4FgrTIBb4orbk=; b=M8EiWhNvRjoSy50/4sZtukSWyjnldfsIl1Pm9foTdFyAyiivI9Syr3Z2yTzmiSxOCj C13cO7ALWMbaykzkNDI0drE5VFde0L4PSSLlW0fFqcHhOn+8d/YCOD4hlJyy6yDqSwxC dQWD8APH6c9KZxv+EEQfpCYjWmV5TO6XCFgSuWmLHV5sVgGKkN/R+IP2ZF4c8FLotmh/ teDzDSvjq6sB6dsUhzoJmasyiASyM0BLWS1DpB6l23aTeITKvDYSYrFiAK7yfQ6Rvgmx ti4k+NWC84JOWQt1GrMMzdLeN5PI+usLt/S9Q8+ZY6icFBF2+J3KqpF69NWjLNVbJXMP IIlg== X-Gm-Message-State: ACgBeo2M6rCEurZC/+DZZgN17LkESBkJdwDxEUL7tsBnVmVArXuFrwgx i+x6KAbaqQEhKqvQqUvQmPo= X-Google-Smtp-Source: AA6agR58mpL41mCLsbAQnLzAhqaKW+kMOnUE0nd2Rrnf9jCoTK+YrEv14D2+ezHdmMtCd9/4X6or9A== X-Received: by 2002:a17:902:8f92:b0:16c:e485:7cd2 with SMTP id z18-20020a1709028f9200b0016ce4857cd2mr930299plo.50.1659046747894; Thu, 28 Jul 2022 15:19:07 -0700 (PDT) Received: from bvanassche-linux.mtv.corp.google.com ([2620:15c:211:201:9520:2952:8318:8e3e]) by smtp.gmail.com with ESMTPSA id k11-20020a170902c40b00b0016dc8932725sm1556709plk.285.2022.07.28.15.19.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 Jul 2022 15:19:07 -0700 (PDT) From: Bart Van Assche To: "Martin K . Petersen" Cc: Jaegeuk Kim , linux-scsi@vger.kernel.org, Adrian Hunter , Bart Van Assche , Ming Lei , Christoph Hellwig , Mike Christie , Hannes Reinecke , John Garry , "James E.J. Bottomley" Subject: [PATCH v5 3/4] scsi: core: Simplify LLD module reference counting Date: Thu, 28 Jul 2022 15:18:50 -0700 Message-Id: <20220728221851.1822295-4-bvanassche@acm.org> X-Mailer: git-send-email 2.37.1.455.g008518b4e5-goog In-Reply-To: <20220728221851.1822295-1-bvanassche@acm.org> References: <20220728221851.1822295-1-bvanassche@acm.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: Ming Lei Swap two statements in scsi_device_put() now that it is guaranteed that SCSI hosts outlive SCSI devices. Remove the reference counting code from scsi_sysfs.c that became superfluous because SCSI hosts now outlive SCSI devices. Cc: Christoph Hellwig Cc: Ming Lei Cc: Mike Christie Cc: Hannes Reinecke Cc: John Garry Signed-off-by: Ming Lei Signed-off-by: Bart Van Assche [ bvanassche: Extracted this patch from a larger patch ] --- drivers/scsi/scsi.c | 9 ++++++--- drivers/scsi/scsi_sysfs.c | 9 --------- 2 files changed, 6 insertions(+), 12 deletions(-) diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index c59eac7a32f2..086ec5b5862d 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -586,10 +586,13 @@ EXPORT_SYMBOL(scsi_device_get); */ void scsi_device_put(struct scsi_device *sdev) { - struct module *mod = sdev->host->hostt->module; - + /* + * Decreasing the module reference count before the device reference + * count is safe since scsi_remove_host() only returns after all + * devices have been removed. + */ + module_put(sdev->host->hostt->module); put_device(&sdev->sdev_gendev); - module_put(mod); } EXPORT_SYMBOL(scsi_device_put); diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 1bc9c26fe1d4..213ebc88f76a 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -452,9 +452,6 @@ static void scsi_device_dev_release_usercontext(struct work_struct *work) struct scsi_vpd *vpd_pg0 = NULL, *vpd_pg89 = NULL; struct scsi_vpd *vpd_pgb0 = NULL, *vpd_pgb1 = NULL, *vpd_pgb2 = NULL; unsigned long flags; - struct module *mod; - - mod = sdev->host->hostt->module; scsi_dh_release_device(sdev); @@ -521,17 +518,11 @@ static void scsi_device_dev_release_usercontext(struct work_struct *work) if (parent) put_device(parent); - module_put(mod); } static void scsi_device_dev_release(struct device *dev) { struct scsi_device *sdp = to_scsi_device(dev); - - /* Set module pointer as NULL in case of module unloading */ - if (!try_module_get(sdp->host->hostt->module)) - sdp->host->hostt->module = NULL; - execute_in_process_context(scsi_device_dev_release_usercontext, &sdp->ew); }