Re: [RFC 0/4] convert create_page_buffers to create_folio_buffers

Luis Chamberlain
2023-04-17T02:27:33Z

On Fri, Apr 14, 2023 at 03:47:13PM +0200, Hannes Reinecke wrote:
> @@ -2333,13 +2395,15 @@ int block_read_full_folio(struct folio *folio,
> get_block_t *get_block)
> if (IS_ENABLED(CONFIG_FS_VERITY) && IS_VERITY(inode))
> limit = inode->i_sb->s_maxbytes;
>
> - VM_BUG_ON_FOLIO(folio_test_large(folio), folio);
> -
> head = create_folio_buffers(folio, inode, 0);
> blocksize = head->b_size;
> bbits = block_size_bits(blocksize);
>
> - iblock = (sector_t)folio->index << (PAGE_SHIFT - bbits);
> + if (WARN_ON(PAGE_SHIFT < bbits)) {
> + iblock = (sector_t)folio->index >> (bbits - PAGE_SHIFT);
> + } else {
> + iblock = (sector_t)folio->index << (PAGE_SHIFT - bbits);
> + }
> lblock = (limit+blocksize-1) >> bbits;
> bh = head;
> nr = 0;

BTW I See this pattern in:

fs/mpage.c: do_mpage_readpage()
fs/mpage.c: __mpage_writepage()

A helper might be in order.

Luis