Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754496AbZCZRdL (ORCPT ); Thu, 26 Mar 2009 13:33:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755789AbZCZRc4 (ORCPT ); Thu, 26 Mar 2009 13:32:56 -0400 Received: from cavan.codon.org.uk ([93.93.128.6]:36332 "EHLO vavatch.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754345AbZCZRcz (ORCPT ); Thu, 26 Mar 2009 13:32:55 -0400 Date: Thu, 26 Mar 2009 17:32:14 +0000 From: Matthew Garrett To: Linus Torvalds Cc: Andrew Morton , Frans Pop , mingo@elte.hu, tytso@mit.edu, jack@suse.cz, alan@lxorguk.ukuu.org.uk, arjan@infradead.org, a.p.zijlstra@chello.nl, npiggin@suse.de, jens.axboe@oracle.com, drees76@gmail.com, jesper@krogh.cc, linux-kernel@vger.kernel.org, oleg@redhat.com, roland@redhat.com, willy@linux.intel.com, vaurora@redhat.com Subject: [PATCH] Allow relatime to update atime once a day Message-ID: <20090326173214.GA7198@srcf.ucam.org> References: <20090325235041.GA11024@duck.suse.cz> <20090326090630.GA9369@elte.hu> <20090326113705.GV32307@mit.edu> <20090326140312.GB14822@elte.hu> <20090326140312.GB14822@elte.hu> <20090326073013.2fa83178.akpm@linux-foundation.org> <200903261632.42439.elendil@planet.nl> <20090326084733.156c4910.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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: 2555 Lines: 86 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, making relatime a plausible default for distributions. Signed-off-by: Matthew Garrett Reviewed-by: Matthew Wilcox Acked-by: Valerie Aurora Henson Acked-by: Alan Cox Acked-by: Ingo Molnar --- 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/