On Wed, Nov 13, 2019 at 10:37:54AM +0100, Jan Kara wrote: > Well, I don't think we want to clutter various places in the code with > checks that inode->i_blkbits (which is what blkbits actually is) is what we > expect. inode->i_blkbits is initialized in fs/inode.c:inode_init_always() > from sb->s_blocksize_bits and never changed. sb->s_blocksize_bits gets set > through sb_set_blocksize(). Now it would make sense to assert in > sb_set_blocksize() that block size is in the range we expect it (currently > there's just a comment there). But then I suspect that Coverity won't be > able to carry over the limits as far as into ext4_iomap_alloc() code... > Kees? Yeah, I'm not sure it's capabilities in this regard. It's still a bit of a black box. :) I just tend to lean toward adding asserts to code-document value range expectations. Perhaps add the check in sb_set_blocksize() just because it's a decent thing to test, and if Coverity doesn't notice, that's okay -- my goal is to improve the kernel which may not always reduce the static checker noise. :) -- Kees Cook
