From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 2A7A82034C087 for ; Thu, 19 Oct 2017 19:42:43 -0700 (PDT) Subject: [PATCH v3 11/13] fs: use smp_load_acquire in break_{layout,lease} From: Dan Williams Date: Thu, 19 Oct 2017 19:39:57 -0700 Message-ID: <150846719726.24336.3564801642993121646.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <150846713528.24336.4459262264611579791.stgit@dwillia2-desk3.amr.corp.intel.com> References: <150846713528.24336.4459262264611579791.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: akpm@linux-foundation.org Cc: "J. Bruce Fields" , linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, Alexander Viro , linux-fsdevel@vger.kernel.org, Jeff Layton , hch@lst.de List-ID: Commit 128a37852234 "fs: fix data races on inode->i_flctx" converted checks of inode->i_flctx to use smp_load_acquire(), but it did not convert break_layout(). smp_load_acquire() includes a READ_ONCE(). There should be no functional difference since __break_lease repeats the sequence, but this is a clean up to unify all ->i_flctx lookups on a common pattern. Cc: Christoph Hellwig Cc: Alexander Viro Cc: Ross Zwisler Cc: Jeff Layton Cc: "J. Bruce Fields" Signed-off-by: Dan Williams --- include/linux/fs.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index 13dab191a23e..eace2c5396a7 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2281,8 +2281,9 @@ static inline int break_lease(struct inode *inode, unsigned int mode) * could end up racing with tasks trying to set a new lease on this * file. */ - smp_mb(); - if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease)) + struct file_lock_context *ctx = smp_load_acquire(&inode->i_flctx); + + if (ctx && !list_empty_careful(&ctx->flc_lease)) return __break_lease(inode, mode, FL_LEASE); return 0; } @@ -2325,8 +2326,9 @@ static inline int break_deleg_wait(struct inode **delegated_inode) static inline int break_layout(struct inode *inode, bool wait) { - smp_mb(); - if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease)) + struct file_lock_context *ctx = smp_load_acquire(&inode->i_flctx); + + if (ctx && !list_empty_careful(&ctx->flc_lease)) return __break_lease(inode, wait ? O_WRONLY : O_WRONLY | O_NONBLOCK, FL_LAYOUT); _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752612AbdJTCq0 (ORCPT ); Thu, 19 Oct 2017 22:46:26 -0400 Received: from mga04.intel.com ([192.55.52.120]:60434 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750964AbdJTCqW (ORCPT ); Thu, 19 Oct 2017 22:46:22 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.43,404,1503385200"; d="scan'208";a="1027184015" Subject: [PATCH v3 11/13] fs: use smp_load_acquire in break_{layout,lease} From: Dan Williams To: akpm@linux-foundation.org Cc: linux-xfs@vger.kernel.org, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, hch@lst.de, "J. Bruce Fields" , linux-mm@kvack.org, Alexander Viro , linux-fsdevel@vger.kernel.org, Jeff Layton , Ross Zwisler Date: Thu, 19 Oct 2017 19:39:57 -0700 Message-ID: <150846719726.24336.3564801642993121646.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <150846713528.24336.4459262264611579791.stgit@dwillia2-desk3.amr.corp.intel.com> References: <150846713528.24336.4459262264611579791.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.17.1-9-g687f MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit 128a37852234 "fs: fix data races on inode->i_flctx" converted checks of inode->i_flctx to use smp_load_acquire(), but it did not convert break_layout(). smp_load_acquire() includes a READ_ONCE(). There should be no functional difference since __break_lease repeats the sequence, but this is a clean up to unify all ->i_flctx lookups on a common pattern. Cc: Christoph Hellwig Cc: Alexander Viro Cc: Ross Zwisler Cc: Jeff Layton Cc: "J. Bruce Fields" Signed-off-by: Dan Williams --- include/linux/fs.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index 13dab191a23e..eace2c5396a7 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2281,8 +2281,9 @@ static inline int break_lease(struct inode *inode, unsigned int mode) * could end up racing with tasks trying to set a new lease on this * file. */ - smp_mb(); - if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease)) + struct file_lock_context *ctx = smp_load_acquire(&inode->i_flctx); + + if (ctx && !list_empty_careful(&ctx->flc_lease)) return __break_lease(inode, mode, FL_LEASE); return 0; } @@ -2325,8 +2326,9 @@ static inline int break_deleg_wait(struct inode **delegated_inode) static inline int break_layout(struct inode *inode, bool wait) { - smp_mb(); - if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease)) + struct file_lock_context *ctx = smp_load_acquire(&inode->i_flctx); + + if (ctx && !list_empty_careful(&ctx->flc_lease)) return __break_lease(inode, wait ? O_WRONLY : O_WRONLY | O_NONBLOCK, FL_LAYOUT); From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: [PATCH v3 11/13] fs: use smp_load_acquire in break_{layout,lease} From: Dan Williams To: akpm@linux-foundation.org Cc: linux-xfs@vger.kernel.org, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, hch@lst.de, "J. Bruce Fields" , linux-mm@kvack.org, Alexander Viro , linux-fsdevel@vger.kernel.org, Jeff Layton , Ross Zwisler Date: Thu, 19 Oct 2017 19:39:57 -0700 Message-ID: <150846719726.24336.3564801642993121646.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <150846713528.24336.4459262264611579791.stgit@dwillia2-desk3.amr.corp.intel.com> References: <150846713528.24336.4459262264611579791.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: Commit 128a37852234 "fs: fix data races on inode->i_flctx" converted checks of inode->i_flctx to use smp_load_acquire(), but it did not convert break_layout(). smp_load_acquire() includes a READ_ONCE(). There should be no functional difference since __break_lease repeats the sequence, but this is a clean up to unify all ->i_flctx lookups on a common pattern. Cc: Christoph Hellwig Cc: Alexander Viro Cc: Ross Zwisler Cc: Jeff Layton Cc: "J. Bruce Fields" Signed-off-by: Dan Williams --- include/linux/fs.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index 13dab191a23e..eace2c5396a7 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2281,8 +2281,9 @@ static inline int break_lease(struct inode *inode, unsigned int mode) * could end up racing with tasks trying to set a new lease on this * file. */ - smp_mb(); - if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease)) + struct file_lock_context *ctx = smp_load_acquire(&inode->i_flctx); + + if (ctx && !list_empty_careful(&ctx->flc_lease)) return __break_lease(inode, mode, FL_LEASE); return 0; } @@ -2325,8 +2326,9 @@ static inline int break_deleg_wait(struct inode **delegated_inode) static inline int break_layout(struct inode *inode, bool wait) { - smp_mb(); - if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease)) + struct file_lock_context *ctx = smp_load_acquire(&inode->i_flctx); + + if (ctx && !list_empty_careful(&ctx->flc_lease)) return __break_lease(inode, wait ? O_WRONLY : O_WRONLY | O_NONBLOCK, FL_LAYOUT); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org