On Sun, Apr 27, 2025 at 04:39:23PM +0800, Yu Kuai wrote:
> page = brd_lookup_page(brd, sector);
>
> kaddr = bvec_kmap_local(&bv);
> if (op_is_write(opf)) {
> - BUG_ON(!page);
> - memcpy_to_page(page, offset, kaddr, bv.bv_len);
> + if (page)
> + memcpy_to_page(page, offset, kaddr, bv.bv_len);
This could use a comment on why page can be NULL here.
> } else if (page) {
> memcpy_from_page(kaddr, page, offset, bv.bv_len);
> } else {
> memset(kaddr, 0, bv.bv_len);
And why the above change my if/else cascade doesn't really make much sense
any more and this should become:
} else {
if (page)
memcpy_from_page(kaddr, page, offset, bv.bv_len);
else
memset(kaddr, 0, bv.bv_len);
}
Otherwise looks good:
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
