[EN] mount of iso image failed on current kernel

[Teriarch]

I booted the system under exactly equal environments and tried to mount an iso image:

$ sudo mount grub.iso /mnt

With kernel 6.7.10-1-siduction-amd64 the call succeeded. With kernel 6.8.2-1-siduction-amd64 it failed:

mount: /mnt: /dev/loop0 already mounted or mount point busy.
       dmesg(1) may have more information after failed mount system call.

When I replaced the kernel under exactly the same environment with some other 6.8 kernel the call
succeeded again. I tried several times to be sure. I compared the kernel configs and the offending
configuration value seems to be:

# CONFIG_BLK_DEV_WRITE_MOUNTED is not set (for the siduction 6.8 kernel
CONFIG_BLK_DEV_WRITE_MOUNTED=y (for the other 6.8 kernel)

Can someone confirm the findings (you can try the Giants ISO image) and maybe remedy
the problem? The snapd depends on mounting read only  images and fails e.g. for the skype app.

[towo]

Code: [Select]

sudo mount -o loop,ro grub.iso /mnt
Should do the trick.

[Teriarch]

Yes, but unfortunately the applications using the respective
system call (fsconfig) do not comply. I get a bunch of everlasting
repetitions of the form:

[  816.577011] Dev loop14: unable to read RDB block 8
[  816.577028]  loop14: unable to read partition table
[  816.577031] loop14: partition table beyond EOD, truncated
[  816.577033] loop_reread_partitions: partition scan of loop14 (/tmp/syscheck-squashfs-3283833802) failed (rc=-5)

resulting from snapd's effort to mount the ro FS for skype. I am wondering whether it be
possible to configure the aforementioned CONFIG option when building the next kernel release.

[towo]

Since snap is not of interest in debian or siduction ...
But nvm, the new kernel has CONFIG_BLK_DEV_WRITE_MOUNTED=y set.

[Teriarch]

Thank you so much!