From 11ff6f05f1e836a6a02369a4c4b64757e484adc1 Mon Sep 17 00:00:00 2001 From: Matthew Garrett Date: Thu, 26 Mar 2009 17:32:14 +0000 Subject: [PATCH] Allow relatime to update atime once a day 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 Signed-off-by: Linus Torvalds --- fs/inode.c | 47 ++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 38 insertions(+), 9 deletions(-) diff --git a/fs/inode.c b/fs/inode.c index 826fb0b9d1c3..6ac0cef6c5f5 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -1290,6 +1290,40 @@ 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 @@ -1317,17 +1351,12 @@ 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; -- 2.30.2