Theodore Ts'o wrote on 07/11/2015 23:06:
> On Sat, Jul 11, 2015 at 02:07:10PM +0200, Jörg-Volker Peetz wrote:
<snip>
> I knew about the fact that you couldn't disable lazytime. The issue
> is that nolazytime is getting intercepted by the 2.26.2 version of
> mount, so ext4 never sees it. But if we interpret the lack of the
> lazytime flag in the mount flags passed in from the system call, then
> we would *always* disable the lazytime flag if the file system is
> remounted using a pre-2.26.2 version of mount. Since a huge number of
> Ubuntu LTS and Debian stable users (and probably a bunch of older
> Fedora users as well) will be using an older version of mount, I
> decided that best compromise is was to allow lazytime to be enabled
> using a 2.26.2+ version of mount via remount, but not to allow
> lazytime to be disabled. With a pre-2.26.2 version of mount, you'll
> be able to enable or disable lazytime.
>
O.k. Thanks for the explanation.
> As far as switching atime modes using remount, this is working for me.
> I'm testing with both a 2.25.2 version of mount as found in Debian
> Jessie, as well as 2.26.2 version of mount using Debian Stretch.
>
>
> The issue not being able to change the atime, relatime, and noatime
> flags is a similar issue. In pre-2.26.2 versions of mount, the atime,
> relatime, and noatime strings were passed to the kernel, which would
> then interpret the strings and the manipulate the
>
>
>> # strace -o /tmp/st mount -o remount,relatime /home
>> # grep ^mount /tmp/st
>> mount("/dev/sda2", "/home", 0x1543780, MS_REMOUNT|MS_RELATIME|MS_NOATIME,
>> "nobarrier,errors=remount-ro") = 0
>
> "MS_REMOUNT|MS_RELATIME|MS_NOATIME" looks wrong. Here's what I'm
> seeing on my system:
>
> # strace -o /tmp/st mount -o remount,relatime /dev/sda3
> # grep sda3 /proc/mounts
> /dev/sda3 / ext4 rw,lazytime,relatime,errors=remount-ro,data=ordered 0 0
> # grep MS_REMOUNT /tmp/st
> mount("/dev/sda3", "/", 0x1148230, MS_REMOUNT|MS_RELATIME|0x2000000, "errors=remount-ro") = 0
> # strace -o /tmp/st mount -o remount,noatime /dev/sda3
> # grep sda3 /proc/mounts
> /dev/sda3 / ext4 rw,lazytime,noatime,errors=remount-ro,data=ordered 0 0
> # grep MS_REMOUNT /tmp/st
> mount("/dev/sda3", "/", 0x1458230, MS_REMOUNT|MS_NOATIME|0x2000000, "errors=remount-ro") = 0
> # mount --version
> mount from util-linux 2.26.2 (libmount 2.26.0: selinux, assert, debug)
> # dpkg -l mount
> Desired=Unknown/Install/Remove/Purge/Hold
> | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
> |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
> ||/ Name Version Architecture Description
> +++-===================-==============-==============-===========================================
> ii mount 2.26.2-6 amd64 Tools for mounting and manipulating filesys
>
> - Ted
On my Debian stretch/sid systems there is:
# mount --version
mount from util-linux 2.26.2 (libmount 2.26.0: selinux, assert, debug)
# dpkg -l mount libmount1 libblkid1 libc6 libselinux1
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-==============-============-============-=================================
ii libblkid1:amd6 2.26.2-6 amd64 block device id library
ii libc6:amd64 2.19-18 amd64 GNU C Library: Shared libraries
ii libmount1:amd6 2.26.2-6 amd64 device mounting library
ii libselinux1:am 2.3-2+b1 amd64 SELinux runtime shared libraries
ii mount 2.26.2-6 amd64 Tools for mounting and manipulati
I'm using kernel 4.1.2 plus two of your patches, but get the same output on a
system with a standard Debian kernel linux-image-4.0.0-2-amd64.
--
Regards,
Jörg.
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
