hi, I come to you for lack of feedback (I think the Linux kernel developers have other cats to whip :-)) would one of you have the answer or a track to follow concerning the question below ? the encountered compilation error is behind the forwarded email. regards, lacsaP. ---------- Forwarded message --------- De : Pascal <patatetom@gmail.com> Date: mer. 8 mars 2023 à 14:09 Subject: bio_check_ro @ blk-core.c hi, I'm addressing you because you intervened (commit <https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/block/blk-core.c?h=v6.1.15&id=bdb7d420c6f6d2618d4c907cd7742c3195c425e2>) in the function bio_check_ro @ blk-core.c @ Linux-LTS-6.1.15. the last time I intervened on this file (@ Linux-LTS-5.10.19 for personal use), it was to replace "return false;" by "return true;", which theoretically should prevent the possible writing on a device locked in read-only mode (see here <https://github.com/vitaly-kamluk/Linux-write-blocker/tree/master/kernel> or here <https://github.com/msuhanov/Linux-write-blocker>). with @ Linux-LTS-6.1.15, if I insert "return true;", I now have a compilation error. in your opinion, is there still a need to "fix" blk-core.c to prevent writing to a read-only locked device and if so, can you help me implement this fix? regards, lacsaP. ---------- End forwarded message --------- SYNC include/config/auto.conf CC arch/x86/kernel/asm-offsets.s CALL scripts/checksyscalls.sh DESCEND objtool DESCEND bpf/resolve_btfids CC block/bdev.o CC block/fops.o CC block/bio.o CC block/elevator.o CC block/blk-core.o block/blk-core.c: In function 'bio_check_ro': block/blk-core.c:496:24: error: 'return' with a value, in function returning void [-Werror=return-type] 496 | return true; | ^~~~ block/blk-core.c:488:20: note: declared here 488 | static inline void bio_check_ro(struct bio *bio) | ^~~~~~~~~~~~ cc1: some warnings being treated as errors make[2]: *** [scripts/Makefile.build:250: block/blk-core.o] Error 1 make[1]: *** [scripts/Makefile.build:500: block] Error 2 make: *** [Makefile:2005: .] Error 2