From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cong Wang Subject: [Patch 3.14 stable 10/16] split dentry_kill() Date: Thu, 6 Nov 2014 11:37:14 -0800 Message-ID: <1415302640-5876-11-git-send-email-xiyou.wangcong@gmail.com> References: <1415302640-5876-1-git-send-email-xiyou.wangcong@gmail.com> Cc: viro@zeniv.linux.org.uk, gregkh@linuxfoundation.org, linux-fsdevel@vger.kernel.org To: stable@vger.kernel.org Return-path: Received: from mail-pa0-f51.google.com ([209.85.220.51]:56312 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751299AbaKFThy (ORCPT ); Thu, 6 Nov 2014 14:37:54 -0500 In-Reply-To: <1415302640-5876-1-git-send-email-xiyou.wangcong@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: From: Al Viro ... into trylocks and everything else. The latter (actual killing) is __dentry_kill(). Signed-off-by: Al Viro (cherry picked from commit e55fd011549eae01a230e3cace6f4d031b6a3453) --- fs/dcache.c | 62 +++++++++++++++++++++++++++++++++++-------------------------- 1 file changed, 36 insertions(+), 26 deletions(-) diff --git a/fs/dcache.c b/fs/dcache.c index b2ad032..9a0ea05 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -440,36 +440,12 @@ void d_drop(struct dentry *dentry) } EXPORT_SYMBOL(d_drop); -/* - * Finish off a dentry we've decided to kill. - * dentry->d_lock must be held, returns with it unlocked. - * If ref is non-zero, then decrement the refcount too. - * Returns dentry requiring refcount drop, or NULL if we're done. - */ -static struct dentry * -dentry_kill(struct dentry *dentry, int unlock_on_failure) - __releases(dentry->d_lock) +static void __dentry_kill(struct dentry *dentry) { - struct inode *inode; struct dentry *parent = NULL; bool can_free = true; - - inode = dentry->d_inode; - if (inode && !spin_trylock(&inode->i_lock)) { -relock: - if (unlock_on_failure) { - spin_unlock(&dentry->d_lock); - cpu_relax(); - } - return dentry; /* try again with same dentry */ - } if (!IS_ROOT(dentry)) parent = dentry->d_parent; - if (parent && !spin_trylock(&parent->d_lock)) { - if (inode) - spin_unlock(&inode->i_lock); - goto relock; - } /* * The dentry is now unrecoverably dead to the world. @@ -513,10 +489,44 @@ dentry_kill(struct dentry *dentry, int unlock_on_failure) can_free = false; } spin_unlock(&dentry->d_lock); -out: if (likely(can_free)) dentry_free(dentry); +} + +/* + * Finish off a dentry we've decided to kill. + * dentry->d_lock must be held, returns with it unlocked. + * If ref is non-zero, then decrement the refcount too. + * Returns dentry requiring refcount drop, or NULL if we're done. + */ +static struct dentry * +dentry_kill(struct dentry *dentry, int unlock_on_failure) + __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: + if (unlock_on_failure) { + spin_unlock(&dentry->d_lock); + cpu_relax(); + } + return dentry; /* try again with same dentry */ } /* -- 1.8.3.1