Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932759AbbHNRzw (ORCPT ); Fri, 14 Aug 2015 13:55:52 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:51852 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932071AbbHNRxZ (ORCPT ); Fri, 14 Aug 2015 13:53:25 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Miklos Szeredi , Al Viro , "Nicholas A. Bellinger" Subject: [PATCH 3.14 40/44] dcache: dont need rcu in shrink_dentry_list() Date: Fri, 14 Aug 2015 10:45:17 -0700 Message-Id: <20150814174402.848023908@linuxfoundation.org> X-Mailer: git-send-email 2.5.0 In-Reply-To: <20150814174401.628233291@linuxfoundation.org> References: <20150814174401.628233291@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2654 Lines: 91 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Miklos Szeredi commit 60942f2f235ce7b817166cdf355eed729094834d upstream. Since now the shrink list is private and nobody can free the dentry while it is on the shrink list, we can remove RCU protection from this. Signed-off-by: Miklos Szeredi Signed-off-by: Al Viro Cc: "Nicholas A. Bellinger" Signed-off-by: Greg Kroah-Hartman --- fs/dcache.c | 27 ++++----------------------- 1 file changed, 4 insertions(+), 23 deletions(-) --- a/fs/dcache.c +++ b/fs/dcache.c @@ -797,23 +797,9 @@ static void shrink_dentry_list(struct li { struct dentry *dentry, *parent; - rcu_read_lock(); - for (;;) { - dentry = list_entry_rcu(list->prev, struct dentry, d_lru); - if (&dentry->d_lru == list) - break; /* empty */ - - /* - * Get the dentry lock, and re-verify that the dentry is - * this on the shrinking list. If it is, we know that - * DCACHE_SHRINK_LIST and DCACHE_LRU_LIST are set. - */ + while (!list_empty(list)) { + dentry = list_entry(list->prev, struct dentry, d_lru); spin_lock(&dentry->d_lock); - if (dentry != list_entry(list->prev, struct dentry, d_lru)) { - spin_unlock(&dentry->d_lock); - continue; - } - /* * The dispose list is isolated and dentries are not accounted * to the LRU here, so we can simply remove it from the list @@ -829,23 +815,20 @@ static void shrink_dentry_list(struct li spin_unlock(&dentry->d_lock); continue; } - rcu_read_unlock(); parent = dentry_kill(dentry, 0); /* * If dentry_kill returns NULL, we have nothing more to do. */ - if (!parent) { - rcu_read_lock(); + if (!parent) continue; - } + if (unlikely(parent == dentry)) { /* * trylocks have failed and d_lock has been held the * whole time, so it could not have been added to any * other lists. Just add it back to the shrink list. */ - rcu_read_lock(); d_shrink_add(dentry, list); spin_unlock(&dentry->d_lock); continue; @@ -859,9 +842,7 @@ static void shrink_dentry_list(struct li dentry = parent; while (dentry && !lockref_put_or_lock(&dentry->d_lockref)) dentry = dentry_kill(dentry, 1); - rcu_read_lock(); } - rcu_read_unlock(); } static enum lru_status -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/