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 Working tree getting out of date "spontaneously"

On 2009.06.05 10:55:08 -0400, Theodore Tso wrote:

On Fri, Jun 05, 2009 at 03:21:26PM +0200, Björn Steinbrink wrote:

quoted

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