From patchwork Fri Feb 16 15:09:31 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Ogness X-Patchwork-Id: 10224889 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 90795603EE for ; Fri, 16 Feb 2018 15:11:06 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 82B35294C9 for ; Fri, 16 Feb 2018 15:11:06 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 777E5294E5; Fri, 16 Feb 2018 15:11:06 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 028BF294C9 for ; Fri, 16 Feb 2018 15:11:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966818AbeBPPKw (ORCPT ); Fri, 16 Feb 2018 10:10:52 -0500 Received: from Galois.linutronix.de ([146.0.238.70]:56542 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966522AbeBPPKK (ORCPT ); Fri, 16 Feb 2018 10:10:10 -0500 Received: from hsi-kbw-5-158-153-53.hsi19.kabel-badenwuerttemberg.de ([5.158.153.53] helo=linux.lab.linutronix.de.) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.80) (envelope-from ) id 1emhat-0003qW-Bb; Fri, 16 Feb 2018 16:06:35 +0100 From: John Ogness To: linux-fsdevel@vger.kernel.org Cc: Al Viro , Linus Torvalds , Christoph Hellwig , Thomas Gleixner , Peter Zijlstra , Sebastian Andrzej Siewior , linux-kernel@vger.kernel.org Subject: [PATCH 2/4] fs/dcache: Move dentry_kill() below lock_parent() Date: Fri, 16 Feb 2018 16:09:31 +0100 Message-Id: <20180216150933.971-3-john.ogness@linutronix.de> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20180216150933.971-1-john.ogness@linutronix.de> References: <20180216150933.971-1-john.ogness@linutronix.de> X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1, SHORTCIRCUIT=-0.0001 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP A subsequent patch will modify dentry_kill() to call lock_parent(). Move the dentry_kill() implementation "as is" below lock_parent() first. This will help simplify the review of the subsequent patch with dentry_kill() changes. Signed-off-by: John Ogness --- fs/dcache.c | 62 ++++++++++++++++++++++++++++++------------------------------- 1 file changed, 31 insertions(+), 31 deletions(-) diff --git a/fs/dcache.c b/fs/dcache.c index 3c7e0148b453..9fed398687c9 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -589,37 +589,6 @@ static void __dentry_kill(struct dentry *dentry) dentry_free(dentry); } -/* - * Finish off a dentry we've decided to kill. - * dentry->d_lock must be held, returns with it unlocked. - * Returns dentry requiring refcount drop, or NULL if we're done. - */ -static struct dentry *dentry_kill(struct dentry *dentry) - __releases(dentry->d_lock) -{ - struct inode *inode = dentry->d_inode; - struct dentry *parent = NULL; - - if (inode && unlikely(!spin_trylock(&inode->i_lock))) - goto failed; - - if (!IS_ROOT(dentry)) { - parent = dentry->d_parent; - if (unlikely(!spin_trylock(&parent->d_lock))) { - if (inode) - spin_unlock(&inode->i_lock); - goto failed; - } - } - - __dentry_kill(dentry); - return parent; - -failed: - spin_unlock(&dentry->d_lock); - return dentry; /* try again with same dentry */ -} - static inline struct dentry *lock_parent(struct dentry *dentry) { struct dentry *parent = dentry->d_parent; @@ -655,6 +624,37 @@ static inline struct dentry *lock_parent(struct dentry *dentry) } /* + * Finish off a dentry we've decided to kill. + * dentry->d_lock must be held, returns with it unlocked. + * Returns dentry requiring refcount drop, or NULL if we're done. + */ +static struct dentry *dentry_kill(struct dentry *dentry) + __releases(dentry->d_lock) +{ + struct inode *inode = dentry->d_inode; + struct dentry *parent = NULL; + + if (inode && unlikely(!spin_trylock(&inode->i_lock))) + goto failed; + + if (!IS_ROOT(dentry)) { + parent = dentry->d_parent; + if (unlikely(!spin_trylock(&parent->d_lock))) { + if (inode) + spin_unlock(&inode->i_lock); + goto failed; + } + } + + __dentry_kill(dentry); + return parent; + +failed: + spin_unlock(&dentry->d_lock); + return dentry; /* try again with same dentry */ +} + +/* * Try to do a lockless dput(), and return whether that was successful. * * If unsuccessful, we return false, having already taken the dentry lock.