Re: Relative atime (was Re: What's in ocfs2.git)

[Karel Zak <kzak@redhat.com>]

On Fri, Dec 08, 2006 at 07:15:14PM -0800, Valerie Henson wrote:
> On Tue, Dec 05, 2006 at 08:58:02PM -0800, Andrew Morton wrote:
> > That's the easy part.   How are we going to get mount(8) patched?
> 
> Karel, interested in taking a look at the following patch?  The kernel
> bits are in -mm currently.

 The patch looks good. I'll add it to my development util-linux tree.
 Thanks.

    Karel

> Add the "relatime" (relative atime) option support to mount.  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.
> 
> Cc: Adrian Bunk <bunk@stusta.de>
> Cc: Al Viro <viro@zeniv.linux.org.uk>
> Cc: Karel Zak <kzak@redhat.com>
> 
> Signed-off-by: Valerie Henson <val_henson@linux.intel.com>
> 
> ---
>  mount/mount.8           |    7 +++++++
>  mount/mount.c           |    6 ++++++
>  mount/mount_constants.h |    4 ++++
>  3 files changed, 17 insertions(+)
> 
> --- util-linux-2.13-pre7.orig/mount/mount.8
> +++ util-linux-2.13-pre7/mount/mount.8
> @@ -586,6 +586,13 @@ access on the news spool to speed up new
>  .B nodiratime
>  Do not update directory inode access times on this filesystem.
>  .TP
> +.B relatime
> +Update inode access times relative to modify or change time.  Access
> +time is only updated if the previous access time was earlier than the
> +current modify or change time. (Similar to noatime, but doesn't break
> +mutt or other applications that need to know if a file has been read
> +since the last time it was modified.)
> +.TP
>  .B noauto
>  Can only be mounted explicitly (i.e., the
>  .B \-a
> --- util-linux-2.13-pre7.orig/mount/mount.c
> +++ util-linux-2.13-pre7/mount/mount.c
> @@ -164,6 +164,12 @@ static const struct opt_map opt_map[] = 
>    { "diratime",	0, 1, MS_NODIRATIME },	/* Update dir access times */
>    { "nodiratime", 0, 0, MS_NODIRATIME },/* Do not update dir access times */
>  #endif
> +#ifdef MS_RELATIME
> +  { "relatime", 0, 0, MS_RELATIME },	/* Update access times relative to
> +					   mtime/ctime */
> +  { "norelatime", 0, 1, MS_RELATIME },	/* Update access time without regard
> +					   to mtime/ctime */
> +#endif
>    { NULL,	0, 0, 0		}
>  };
>  
> --- util-linux-2.13-pre7.orig/mount/mount_constants.h
> +++ util-linux-2.13-pre7/mount/mount_constants.h
> @@ -57,6 +57,10 @@ if we have a stack or plain mount - moun
>  #ifndef MS_VERBOSE
>  #define MS_VERBOSE	0x8000	/* 32768 */
>  #endif
> +#ifndef MS_RELATIME
> +#define MS_RELATIME   0x200000	/* 200000: Update access times relative
> +				   to mtime/ctime */
> +#endif
>  /*
>   * Magic mount flag number. Had to be or-ed to the flag values.
>   */
> -
> To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

-- 
 Karel Zak  <kzak@redhat.com>