2006-08-25 23:52:40

by Valerie Henson

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Subject: [patch 0/1] Relative atime

There was enough interest in the relative atime patches that I went
ahead and implemented support in the mount command as well, and
cleaned up the patches for inclusion. Relative atime only updates the
atime if the previous atime is older than the mtime or ctime. It's
like noatime, but useful for applications like mutt that need to know
whether a file has been read since it was last modified.

-VAL


2006-08-25 23:56:29

by Valerie Henson

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Subject: [patch] Relative atime - userspace

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.

Signed-off-by: Valerie Henson <[email protected]>

---
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.
*/

2006-08-28 21:51:38

by Josef Sipek

[permalink] [raw]
Subject: Re: [patch] Relative atime - userspace

On Fri, Aug 25, 2006 at 04:56:19PM -0700, Valerie Henson wrote:
> #define MS_VERBOSE 0x8000 /* 32768 */
...
> +#define MS_RELATIME 0x200000 /* 200000: Update access times relative

Just a small thing... 0x200000 != 200000

Josef "Jeff" Sipek.

--
Evolution, n.:
A hypothetical process whereby infinitely improbable events occur with
alarming frequency, order arises from chaos, and no one is given credit.

2006-08-29 00:15:01

by Valerie Henson

[permalink] [raw]
Subject: Re: [patch] Relative atime - userspace

On Mon, Aug 28, 2006 at 05:49:01PM -0400, Josef Sipek wrote:
> On Fri, Aug 25, 2006 at 04:56:19PM -0700, Valerie Henson wrote:
> > #define MS_VERBOSE 0x8000 /* 32768 */
> ...
> > +#define MS_RELATIME 0x200000 /* 200000: Update access times relative
>
> Just a small thing... 0x200000 != 200000

Just goes to show what my default base is... :)

Somehow "2097152: blah blah blah" just doesn't seem helpful - I just
removed it. Fresh patch below.

-VAL

---
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 /* Update access times relative
+ to mtime/ctime */
+#endif
/*
* Magic mount flag number. Had to be or-ed to the flag values.
*/