Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754876AbYKZTzS (ORCPT ); Wed, 26 Nov 2008 14:55:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752636AbYKZTzD (ORCPT ); Wed, 26 Nov 2008 14:55:03 -0500 Received: from cavan.codon.org.uk ([93.93.128.6]:42428 "EHLO vavatch.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752220AbYKZTzA (ORCPT ); Wed, 26 Nov 2008 14:55:00 -0500 Date: Wed, 26 Nov 2008 19:54:57 +0000 From: Matthew Garrett To: linux-kernel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, mingo@redhat.com, val.henson@gmail.com Subject: [PATCH 1/2] relatime: Make atime updates more useful Message-ID: <20081126195457.GA3541@srcf.ucam.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.12-2006-07-14 X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: mjg59@codon.org.uk X-SA-Exim-Scanned: No (on vavatch.codon.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2763 Lines: 97 Allow atime to be updated once per day even with relatime enabled. This lets utilities like tmpreaper (which deletes files based on last access time) continue working. Signed-off-by: Matthew Garrett --- Updated version of Ingo's patch from last year - this section is identical. commit 2c145e187600ca961715fa82ae3ae7919d744bc9 Author: Matthew Garrett Date: Wed Nov 26 17:44:07 2008 +0000 Make relatime smarter Allow atime to be updated once per day even with relatime. This lets utilities like tmpreaper (which delete files based on last access time) continue working. diff --git a/fs/inode.c b/fs/inode.c index 0487ddb..348fa16 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -1179,6 +1179,41 @@ sector_t bmap(struct inode * inode, sector_t block) } EXPORT_SYMBOL(bmap); +/* + * Relative atime updates frequency (default: 1 day): + */ +int relatime_interval __read_mostly = 24*60*60; + +/* + * With relative atime, only update atime if the + * previous atime is earlier than either the ctime or + * mtime. + */ +static int relatime_need_update(struct inode *inode, struct timespec now) +{ + /* + * Is mtime younger than atime? If yes, update atime: + */ + if (timespec_compare(&inode->i_mtime, &inode->i_atime) >= 0) + return 1; + /* + * Is ctime younger than atime? If yes, update atime: + */ + if (timespec_compare(&inode->i_ctime, &inode->i_atime) >= 0) + return 1; + + /* + * Is the previous atime value older than the update interval? + * If yes, update atime: + */ + if ((long)(now.tv_sec - inode->i_atime.tv_sec) >= relatime_interval) + return 1; + /* + * Good, we can skip the atime update: + */ + return 0; +} + /** * touch_atime - update the access time * @mnt: mount the inode is accessed on @@ -1206,17 +1241,12 @@ void touch_atime(struct vfsmount *mnt, struct dentry *dentry) goto out; if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)) goto out; - if (mnt->mnt_flags & MNT_RELATIME) { - /* - * With relative atime, only update atime if the previous - * atime is earlier than either the ctime or mtime. - */ - if (timespec_compare(&inode->i_mtime, &inode->i_atime) < 0 && - timespec_compare(&inode->i_ctime, &inode->i_atime) < 0) - goto out; - } now = current_fs_time(inode->i_sb); + + if (mnt->mnt_flags & MNT_RELATIME) + if (!relatime_need_update(inode, now)) + goto out; if (timespec_equal(&inode->i_atime, &now)) goto out; -- Matthew Garrett | mjg59@srcf.ucam.org -- 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/