Commit 47ae32d6 authored by Valerie Henson's avatar Valerie Henson Committed by Linus Torvalds
Browse files

[PATCH] relative atime 

Add "relatime" (relative atime) support.  Relative atime only updates the
atime if the previous atime is older than the mtime or ctime.  Like
noatime, but useful for applications like mutt that need to know when a
file has been read since it was last modified.

A corresponding patch against mount(8) is available at
http://userweb.kernel.org/~akpm/mount-relative-atime.txt



Signed-off-by: default avatarValerie Henson <val_henson@linux.intel.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Karel Zak <kzak@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent b2276138

fs/inode.c

+18 −4
Original line number Diff line number Diff line
@@ -1177,14 +1177,28 @@ void touch_atime(struct vfsmount *mnt, struct dentry *dentry) 
			return;

		if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode))

			return;



		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)

				return;

		}

	}



	now = current_fs_time(inode->i_sb);

	if (!timespec_equal(&inode->i_atime, &now)) {

	if (timespec_equal(&inode->i_atime, &now))

		return;



	inode->i_atime = now;

	mark_inode_dirty_sync(inode);

}

}

EXPORT_SYMBOL(touch_atime);



/**

fs/namespace.c

+4 −1
Original line number Diff line number Diff line
@@ -368,6 +368,7 @@ static int show_vfsmnt(struct seq_file *m, void *v) 
		{ MNT_NOEXEC, ",noexec" },

		{ MNT_NOATIME, ",noatime" },

		{ MNT_NODIRATIME, ",nodiratime" },

		{ MNT_RELATIME, ",relatime" },

		{ 0, NULL }

	};

	struct proc_fs_info *fs_infop;
@@ -1405,9 +1406,11 @@ long do_mount(char *dev_name, char *dir_name, char *type_page, 
		mnt_flags |= MNT_NOATIME;

	if (flags & MS_NODIRATIME)

		mnt_flags |= MNT_NODIRATIME;

	if (flags & MS_RELATIME)

		mnt_flags |= MNT_RELATIME;



	flags &= ~(MS_NOSUID | MS_NOEXEC | MS_NODEV | MS_ACTIVE |

		   MS_NOATIME | MS_NODIRATIME);

		   MS_NOATIME | MS_NODIRATIME | MS_RELATIME);



	/* ... and get the mountpoint */

	retval = path_lookup(dir_name, LOOKUP_FOLLOW, &nd);

include/linux/fs.h

+1 −0
Original line number Diff line number Diff line
@@ -120,6 +120,7 @@ extern int dir_notify_enable; 
#define MS_PRIVATE	(1<<18)	/* change to private */

#define MS_SLAVE	(1<<19)	/* change to slave */

#define MS_SHARED	(1<<20)	/* change to shared */

#define MS_RELATIME	(1<<21)	/* Update atime relative to mtime/ctime. */

#define MS_ACTIVE	(1<<30)

#define MS_NOUSER	(1<<31)

include/linux/mount.h

+1 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ struct mnt_namespace; 
#define MNT_NOEXEC	0x04

#define MNT_NOATIME	0x08

#define MNT_NODIRATIME	0x10

#define MNT_RELATIME	0x20



#define MNT_SHRINKABLE	0x100

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