Re: ext4 lazytime: ctime of some files changed

["Jörg-Volker Peetz" <jvpeetz@web.de>]

Jörg-Volker Peetz wrote on 05/13/2015 11:35:
> Dear Ted,
> 
> on my laptop with ext4 fs (on SSD) I started to try the lazytime mount option
> using a self compiled kernel 4.0.2 on a debian system with mount version 2.26.2.
> Before that, I've used the noatime mount option.
> 
> After restarting the system with an adapted /etc/fstab file and the kernel
> parameter "rootflags=lazytime", the relatime mount option was also set. I
> changed that by commanding "mount -o remount,strictatime /", etc.
> By accident, I noticed that some files had a modified ctime and mtime although
> they were not changed or modified.
> 
> Has anybody else experienced that? Do I miss a patch?
> 
> Mount options in fstab: nobarrier,lazytime,errors=remount-ro
> The filesystems are ext4 on a primary partition of the SSD with default mount
> option journal_data_writeback. I created them in Feb 2011.
> 
> By the way, the command "mount -o remount,lazytime /" does not do the switch to
> lazytime.
> 
> And thanks for your tireless work on Linux.
> 

After writing the above, I encountered another accident regarding two files of
the emacs24 package of which the mtime got changed.

I tried to repair this by using versions of the two files with the correct mtime
in the /tmp directory and commanded

> touch -r /tmp/debian-ispell.elc
/usr/share/emacs24/site-lisp/dictionaries-common/debian-ispell.elc
> touch -r /tmp/ess-noweb-font-lock-mode.elc
/usr/share/emacs24/site-lisp/ess/ess-noweb-font-lock-mode.elc

A few hours later I unpacked and tested a tar archive by commanding s.t. like

> tar xf linux-4.0.tar.xz
> sync
> echo 3 >/proc/sys/vm/drop_caches
> tar df linux-4.0.tar.xz

Thereafter, the two emacs package files again had a wrong mtime (which by the
way shows when I start emacs).

Could this be due to the lazytime mount option?
-- 
Regards,
jvp.


--
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