[Jfs-discussion] jfs directory modification times

[James F. <ja...@cl...>]

There's a hint in the archives about this, but nothing concrete and
google doesn't find anything helpful to me.

I'm running Centos 4.2 with kernel-2.6.9-22.0.2.106.unsupported and
jfsutils-1.1.10-3.2 from the centosplus distribution, with a jfs
partition for my maildir mail spool, accessed using the dovecot IMAP
server. It seems that dovecot doesn't properly track new incoming email,
apparently because the modification time on .../Maildir/new doesn't get
updated when a new message is linked into it from .../Maildir/tmp.

A quick manual test gives:

    $ mkdir a b
    $ cd b
    $ ls -al
    total 4
    drwxr-xr-x   2 root root  1 Feb 16 15:51 .
    drwxr-xr-x  11 root root 72 Feb 16 15:51 ..
    $ touch c
    $ ls -la
    total 4
    drwxr-xr-x   2 root root  8 Feb 16 15:56 .
    drwxr-xr-x  11 root root 72 Feb 16 15:51 ..
    -rw-r--r--   1 root root  0 Feb 16 15:56 c
    $ ls -al ../a
    total 4
    drwxr-xr-x   2 root root  1 Feb 16 15:51 .
    drwxr-xr-x  11 root root 72 Feb 16 15:51 ..
    $ ln c ../a
    $ ls -la ../a
    total 4
    drwxr-xr-x   2 root root  8 Feb 16 15:51 .
    drwxr-xr-x  11 root root 72 Feb 16 15:51 ..
    -rw-r--r--   2 root root  0 Feb 16 15:56 c

showing that directory "a" doesn't have the modification date changed when
file "c" is linked into it from "b".  On an ext3 filesystem however:

    $ mkdir a b
    $ cd b
    ls -la
    total 12
    drwxrwxr-x   2 james james 4096 Feb 16 17:00 .
    drwxrwxrwt  18 root  root  4096 Feb 16 17:00 ..
    $ touch c
    $ ls -la
    total 12
    drwxrwxr-x   2 james james 4096 Feb 16 17:01 .
    drwxrwxrwt  18 root  root  4096 Feb 16 17:00 ..
    -rw-rw-r--   1 james james    0 Feb 16 17:01 c
    $ ls -al ../a
    total 12
    drwxrwxr-x   2 james james 4096 Feb 16 17:00 .
    drwxrwxrwt  18 root  root  4096 Feb 16 17:00 ..
    $ ln c ../a
    $ ls -al ../a
    total 12
    drwxrwxr-x   2 james james 4096 Feb 16 17:02 .
    drwxrwxrwt  18 root  root  4096 Feb 16 17:00 ..
    -rw-rw-r--   2 james james    0 Feb 16 17:01 c

and the last mod date on "a" is changed.  UFS on FreeBSD exhibits the same
behaviour as ext3.

Is this a known problem?  Documented behaviour?  Is there a way to get
the behaviour I want?

James