hi,

the bio_check_ro function of the blk-core.c source file of the Linux kernel
refers to LVM :
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/block/blk-core.c?h=v6.2.7#n500

how does LVM currently behave when faced with a device marked as readonly ?
does it automatically switch itself in readonly mode?

according to some tests carried out in a virtual machine, it seems that it
doesn't and that LVM modifies the disk/partition(s) even though they are
all readonly (chmod 444 && blockdev --setro).

regards, lacsaP.