From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 862E9CA9EAF for ; Sun, 27 Oct 2019 22:03:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5D6E52064A for ; Sun, 27 Oct 2019 22:03:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728035AbfJ0WDN (ORCPT ); Sun, 27 Oct 2019 18:03:13 -0400 Received: from mx2.suse.de ([195.135.220.15]:48398 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726881AbfJ0WDN (ORCPT ); Sun, 27 Oct 2019 18:03:13 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id DE7E7AD78; Sun, 27 Oct 2019 22:03:11 +0000 (UTC) From: Davidlohr Bueso To: dsterba@suse.com Cc: dave@stgolabs.net, linux-kernel@vger.kernel.org, Davidlohr Bueso Subject: [PATCH] fs/affs: Replace binary semaphores with mutexes Date: Sun, 27 Oct 2019 15:01:43 -0700 Message-Id: <20191027220143.10756-1-dave@stgolabs.net> X-Mailer: git-send-email 2.16.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org At a slight footprint cost (24 vs 32 bytes), mutexes are more optimal than semaphores; it's also a nicer interface for mutual exclusion, which is why they are encouraged over binary semaphores, when possible. For both i_link_lock and i_ext_lock (and hence i_hash_lock which I annotated for the hash lock mapping hackery for lockdep), their semantics imply traditional lock ownership; that is, the lock owner is the same for both lock/unlock operations and does not run in irq context. Therefore it is safe to convert. Signed-off-by: Davidlohr Bueso --- Compile tested only. fs/affs/affs.h | 16 ++++++++-------- fs/affs/super.c | 4 ++-- 2 files changed, 10 insertions(+), 10 deletions(-) diff --git a/fs/affs/affs.h b/fs/affs/affs.h index a92eb6ae2ae2..a755bef7c4c7 100644 --- a/fs/affs/affs.h +++ b/fs/affs/affs.h @@ -43,8 +43,8 @@ struct affs_ext_key { */ struct affs_inode_info { atomic_t i_opencnt; - struct semaphore i_link_lock; /* Protects internal inode access. */ - struct semaphore i_ext_lock; /* Protects internal inode access. */ + struct mutex i_link_lock; /* Protects internal inode access. */ + struct mutex i_ext_lock; /* Protects internal inode access. */ #define i_hash_lock i_ext_lock u32 i_blkcnt; /* block count */ u32 i_extcnt; /* extended block count */ @@ -293,30 +293,30 @@ affs_adjust_bitmapchecksum(struct buffer_head *bh, u32 val) static inline void affs_lock_link(struct inode *inode) { - down(&AFFS_I(inode)->i_link_lock); + mutex_lock(&AFFS_I(inode)->i_link_lock); } static inline void affs_unlock_link(struct inode *inode) { - up(&AFFS_I(inode)->i_link_lock); + mutex_unlock(&AFFS_I(inode)->i_link_lock); } static inline void affs_lock_dir(struct inode *inode) { - down(&AFFS_I(inode)->i_hash_lock); + mutex_lock_nested(&AFFS_I(inode)->i_hash_lock, SINGLE_DEPTH_NESTING); } static inline void affs_unlock_dir(struct inode *inode) { - up(&AFFS_I(inode)->i_hash_lock); + mutex_unlock(&AFFS_I(inode)->i_hash_lock); } static inline void affs_lock_ext(struct inode *inode) { - down(&AFFS_I(inode)->i_ext_lock); + mutex_lock(&AFFS_I(inode)->i_ext_lock); } static inline void affs_unlock_ext(struct inode *inode) { - up(&AFFS_I(inode)->i_ext_lock); + mutex_unlock(&AFFS_I(inode)->i_ext_lock); } diff --git a/fs/affs/super.c b/fs/affs/super.c index cc463ae47c12..9fcff55c65af 100644 --- a/fs/affs/super.c +++ b/fs/affs/super.c @@ -121,8 +121,8 @@ static void init_once(void *foo) { struct affs_inode_info *ei = (struct affs_inode_info *) foo; - sema_init(&ei->i_link_lock, 1); - sema_init(&ei->i_ext_lock, 1); + mutex_init(&ei->i_link_lock); + mutex_init(&ei->i_ext_lock); inode_init_once(&ei->vfs_inode); } -- 2.16.4