Re: [BUG ext4?] Working tree getting out of date "spontaneously"

["Björn Steinbrink" <B.Steinbrink@gmx.de>]

On 2009.06.05 10:55:08 -0400, Theodore Tso wrote:
> On Fri, Jun 05, 2009 at 03:21:26PM +0200, Björn Steinbrink wrote:
> > So the ctime got modified. I don't have any fancy indexing stuff
> > running, and inotify doesn't see any events either while the ctime is
> > changed.
> > 
> > The only thing I changed lately was upgrading to 2.6.30-rc8 and going
> > from ext3 to ext4. As the ctime change always seems to happen around 30
> > seconds after the real change, I kind of suspect ext4 to be guilty.
> > Ted, is that possible?
> > 
> > FS is mounted as:
> > /dev/mapper/vg0-home on /home type ext4 (rw,noatime,nodiratime,barrier=0)
> > 
> 
> I agree it sounds like it's ext4 related, but I'm not able to
> reproduce it (using 2.6.30-rc8 with the patches planned for the 2.6.31
> merge window).  This should show the problem, you were seeing, do you
> agree?

Yeah, that should do I guess. See my other mail for a simpler, less
time consuming way to test. And as noted in there, it seems to happen
only on ext3 filesystems mounted using ext4.

> <tytso@closure> {/usr/projects/linux/misc}  [master]
> 547% git reset --hard HEAD^
> HEAD is now at b63254c Merge branch 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6
> <tytso@closure> {/usr/projects/linux/misc}  [master]
> 548% git pull
> Updating b63254c..b87297f
> Fast forward
>  drivers/gpu/drm/i915/i915_gem.c |    3 ---
>  1 files changed, 0 insertions(+), 3 deletions(-)
> <tytso@closure> {/usr/projects/linux/misc}  [master]
> 549% stat drivers/gpu/drm/i915/i915_gem.c;sleep 60 ; stat drivers/gpu/drm/i915/i915_gem.c
>   File: `drivers/gpu/drm/i915/i915_gem.c'
>   Size: 117594		Blocks: 232        IO Block: 4096   regular file
> Device: fe00h/65024d	Inode: 2643071     Links: 1
> Access: (0644/-rw-r--r--)  Uid: (15806/   tytso)   Gid: (15806/   tytso)
> Access: 2009-06-05 10:50:05.466966433 -0400
> Modify: 2009-06-05 10:50:05.466966433 -0400
> Change: 2009-06-05 10:50:05.466966433 -0400
>   File: `drivers/gpu/drm/i915/i915_gem.c'
>   Size: 117594		Blocks: 232        IO Block: 4096   regular file
> Device: fe00h/65024d	Inode: 2643071     Links: 1
> Access: (0644/-rw-r--r--)  Uid: (15806/   tytso)   Gid: (15806/   tytso)
> Access: 2009-06-05 10:50:05.466966433 -0400
> Modify: 2009-06-05 10:50:05.466966433 -0400
> Change: 2009-06-05 10:50:05.466966433 -0400
> 
> Hmm, can you send me the output of dumpe2fs -h for your /home
> filesystem?

dumpe2fs 1.41.6 (30-May-2009)
Filesystem volume name:   <none>
Last mounted on:          <not available>
Filesystem UUID:          4cc724c1-e366-41d7-8dee-baa6624bd04c
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      has_journal resize_inode dir_index filetype
                          needs_recovery sparse_super large_file
Filesystem flags:         signed_directory_hash 
Default mount options:    (none)
Filesystem state:         clean
Errors behavior:          Continue
Filesystem OS type:       Linux
Inode count:              15548416
Block count:              31095808
Reserved block count:     0
Free blocks:              19016208
Free inodes:              15221178
First block:              0
Block size:               4096
Fragment size:            4096
Reserved GDT blocks:      1016
Blocks per group:         32768
Fragments per group:      32768
Inodes per group:         16384
Inode blocks per group:   512
Filesystem created:       Tue May 15 19:50:48 2007
Last mount time:          Thu Jun  4 21:31:36 2009
Last write time:          Thu Jun  4 21:31:36 2009
Mount count:              17
Maximum mount count:      21
Last checked:             Tue Mar 24 15:15:08 2009
Check interval:           15552000 (6 months)
Next check after:         Sun Sep 20 16:15:08 2009
Lifetime writes:          37 GB
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)
First inode:              11
Inode size:               128
Journal inode:            8
Default directory hash:   tea
Directory Hash Seed:      55e920c6-f31f-4761-b9d3-3ab558dc5746
Journal backup:           inode blocks
Journal size:             128M

Thanks,
Björn