Hi
On 2023-05-21 01:39, Thomas Weißschuh wrote:
I am having trouble reproducing the issue.
Could you
* provide more details about the used kernel?
* provide reproduction steps that are simple to reproduce, for example
using tmpfs mounts.
Used kernel.config: https://0x0.st/HqKc.txt
I cannot reproduce using tmpfs, i.e.
# mkdir /mnt/test
# mount -t tmpfs none /mnt/test
# mount -l | grep test
none on /mnt/test type tmpfs (rw,relatime)
# touch /mnt/test/foo.txt
# mount -o remount,ro /mnt/test
# date >> /mnt/test/foo.txt
-bash: /mnt/test/foo.txt: Read-only file system
# mount -o remount,rw /mnt/test
# date >> /mnt/test/foo.txt
# cat /mnt/test/foo.txt
Sun May 21 11:04:42 PM CEST 2023
works.
But on boot, when the init system remounts root filesystem (using
command "mount -n -o remount,rw /"), the command seems to be successful
(mount command exits with zero exit code) but the root filesystem is
still read-only and all following services expecting writable rootfs
will fail.
I have
UUID=e290359f-8335-4fba-9fae-077b3505e0b2 / ext4 defaults 0 1
in /etc/fstab. I saw https://github.com/util-linux/util-linux/pull/2250
but this doesn't help (and changing "defaults" to "relatime" didn't help
either).
I added strace to the init script trying to remount root read/write:
Booting linux-5.10.180 using util-linux-2.39 with PR 2248 and PR 2250
applied: https://0x0.st/HqKL.180.png
=> mount isn't doing anything; root will stay read-only.
When I use same util-linux but boot linux-5.15.112 instead:
https://0x0.st/HqK9.112.png
=> mount is doing something; root will become read/write.
--
Regards,
Thomas
