From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Layton Subject: [PATCH v7 21/49] vfs: add a retry_estale helper function to handle retries on ESTALE Date: Mon, 1 Oct 2012 20:16:30 -0400 Message-ID: <1349137018-21948-22-git-send-email-jlayton@redhat.com> References: <1349137018-21948-1-git-send-email-jlayton@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com (ext-mx13.extmail.prod.ext.phx2.redhat.com [10.5.110.18]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id q920HZSk006684 for ; Mon, 1 Oct 2012 20:17:35 -0400 Received: from mail-yx0-f174.google.com (mail-yx0-f174.google.com [209.85.213.174]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q920H6tH018698 for ; Mon, 1 Oct 2012 20:17:35 -0400 Received: by mail-yx0-f174.google.com with SMTP id m12so1534914yen.33 for ; Mon, 01 Oct 2012 17:17:34 -0700 (PDT) In-Reply-To: <1349137018-21948-1-git-send-email-jlayton@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-audit-bounces@redhat.com Errors-To: linux-audit-bounces@redhat.com To: viro@ZenIV.linux.org.uk Cc: linux-fsdevel@vger.kernel.org, linux-audit@redhat.com, linux-kernel@vger.kernel.org List-Id: linux-audit@redhat.com This function is expected to be called from path-based syscalls to help them decide whether to try the lookup and call again in the event that they got an -ESTALE return back on an earier try. Currently, we only retry the call once on an ESTALE error, but in the event that we decide that that's not enough in the future, we should be able to change the logic in this helper without too much effort. Signed-off-by: Jeff Layton --- include/linux/fs.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/include/linux/fs.h b/include/linux/fs.h index a3c2c17..78e8639 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2221,6 +2221,27 @@ extern int finish_open(struct file *file, struct dentry *dentry, int *opened); extern int finish_no_open(struct file *file, struct dentry *dentry); +/** + * retry_estale - determine whether the caller should retry an operation + * + * @error: the error we'll be returning + * @try: number of retries already performed + * + * Check to see if the error code was -ESTALE, and then determine whether + * to retry the call based on the number of retries so far. Currently, we only + * retry the call once. + * + * Returns true if the caller should try again. + */ +static inline bool +retry_estale(const long error, const unsigned int try) +{ + if (likely(error != -ESTALE)) + return false; + + return !try; +} + /* fs/ioctl.c */ extern int ioctl_preallocate(struct file *filp, void __user *argp); -- 1.7.11.4