Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755744AbYLBRTm (ORCPT ); Tue, 2 Dec 2008 12:19:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753573AbYLBRTb (ORCPT ); Tue, 2 Dec 2008 12:19:31 -0500 Received: from cavan.codon.org.uk ([93.93.128.6]:33418 "EHLO vavatch.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751334AbYLBRTa (ORCPT ); Tue, 2 Dec 2008 12:19:30 -0500 Date: Tue, 2 Dec 2008 17:19:26 +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] relatime: Let relatime update atime at least once per day Message-ID: <20081202171926.GB20405@srcf.ucam.org> References: <20081126195457.GA3541@srcf.ucam.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081126195457.GA3541@srcf.ucam.org> 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: 2675 Lines: 89 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. Signed-off-by: Matthew Garrett Acked-by: Ingo Molnar Acked-by: Alan Cox --- I've removed the adjustable time code, since nobody's come up with a terribly good use case for it. This makes relatime more useful in the generic case - there may be situations where it still doesn't satisfy people, but that's not a regression over the current situation. diff --git a/fs/inode.c b/fs/inode.c index 0487ddb..057c92b 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -1179,6 +1179,40 @@ sector_t bmap(struct inode * inode, sector_t block) } EXPORT_SYMBOL(bmap); +/* + * With relative atime, only update atime if the previous atime is + * earlier than either the ctime or mtime or if at least a day has + * passed since the last atime update. + */ +static int relatime_need_update(struct vfsmount *mnt, struct inode *inode, + struct timespec now) +{ + + if (!(mnt->mnt_flags & MNT_RELATIME)) + return 1; + /* + * 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 a day? If yes, + * update atime: + */ + if ((long)(now.tv_sec - inode->i_atime.tv_sec) >= 24*60*60) + 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 +1240,12 @@ 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 (!relatime_need_update(mnt, 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/