From 211d04445b96db5b3640bcf345ad59105068a549 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Fri, 10 Jun 2022 22:58:24 -0400 Subject: mpage: Convert do_mpage_readpage() to use a folio Pass in a folio from mpage_readahead(). Also convert map_buffer_to_page() to map_buffer_to_folio(). There's still no support for large folios here; there are numerous places which depend on the folio being PAGE_SIZE. The VM_BUG_ON prevents anyone from thinking that it will work. Signed-off-by: Matthew Wilcox (Oracle) --- fs/mpage.c | 78 ++++++++++++++++++++++++++++++++------------------------------ 1 file changed, 40 insertions(+), 38 deletions(-) (limited to 'fs/mpage.c') diff --git a/fs/mpage.c b/fs/mpage.c index 0d25f44f5707..681a4b9a36e3 100644 --- a/fs/mpage.c +++ b/fs/mpage.c @@ -75,26 +75,28 @@ static struct bio *mpage_bio_submit(struct bio *bio) * them. So when the buffer is up to date and the page size == block size, * this marks the page up to date instead of adding new buffers. */ -static void -map_buffer_to_page(struct page *page, struct buffer_head *bh, int page_block) +static void map_buffer_to_folio(struct folio *folio, struct buffer_head *bh, + int page_block) { - struct inode *inode = page->mapping->host; + struct inode *inode = folio->mapping->host; struct buffer_head *page_bh, *head; int block = 0; - if (!page_has_buffers(page)) { + head = folio_buffers(folio); + if (!head) { /* * don't make any buffers if there is only one buffer on - * the page and the page just needs to be set up to date + * the folio and the folio just needs to be set up to date */ if (inode->i_blkbits == PAGE_SHIFT && buffer_uptodate(bh)) { - SetPageUptodate(page); + folio_mark_uptodate(folio); return; } - create_empty_buffers(page, i_blocksize(inode), 0); + create_empty_buffers(&folio->page, i_blocksize(inode), 0); + head = folio_buffers(folio); } - head = page_buffers(page); + page_bh = head; do { if (block == page_block) { @@ -110,7 +112,7 @@ map_buffer_to_page(struct page *page, struct buffer_head *bh, int page_block) struct mpage_readpage_args { struct bio *bio; - struct page *page; + struct folio *folio; unsigned int nr_pages; bool is_readahead; sector_t last_block_in_bio; @@ -130,8 +132,8 @@ struct mpage_readpage_args { */ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args) { - struct page *page = args->page; - struct inode *inode = page->mapping->host; + struct folio *folio = args->folio; + struct inode *inode = folio->mapping->host; const unsigned blkbits = inode->i_blkbits; const unsigned blocks_per_page = PAGE_SIZE >> blkbits; const unsigned blocksize = 1 << blkbits; @@ -148,17 +150,20 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args) int op = REQ_OP_READ; unsigned nblocks; unsigned relative_block; - gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL); + gfp_t gfp = mapping_gfp_constraint(folio->mapping, GFP_KERNEL); + + /* MAX_BUF_PER_PAGE, for example */ + VM_BUG_ON_FOLIO(folio_test_large(folio), folio); if (args->is_readahead) { op |= REQ_RAHEAD; gfp |= __GFP_NORETRY | __GFP_NOWARN; } - if (page_has_buffers(page)) + if (folio_buffers(folio)) goto confused; - block_in_file = (sector_t)page->index << (PAGE_SHIFT - blkbits); + block_in_file = (sector_t)folio->index << (PAGE_SHIFT - blkbits); last_block = block_in_file + args->nr_pages * blocks_per_page; last_block_in_file = (i_size_read(inode) + blocksize - 1) >> blkbits; if (last_block > last_block_in_file) @@ -191,9 +196,9 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args) } /* - * Then do more get_blocks calls until we are done with this page. + * Then do more get_blocks calls until we are done with this folio. */ - map_bh->b_page = page; + map_bh->b_page = &folio->page; while (page_block < blocks_per_page) { map_bh->b_state = 0; map_bh->b_size = 0; @@ -216,12 +221,12 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args) /* some filesystems will copy data into the page during * the get_block call, in which case we don't want to - * read it again. map_buffer_to_page copies the data - * we just collected from get_block into the page's buffers - * so readpage doesn't have to repeat the get_block call + * read it again. map_buffer_to_folio copies the data + * we just collected from get_block into the folio's buffers + * so read_folio doesn't have to repeat the get_block call */ if (buffer_uptodate(map_bh)) { - map_buffer_to_page(page, map_bh, page_block); + map_buffer_to_folio(folio, map_bh, page_block); goto confused; } @@ -246,18 +251,18 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args) } if (first_hole != blocks_per_page) { - zero_user_segment(page, first_hole << blkbits, PAGE_SIZE); + folio_zero_segment(folio, first_hole << blkbits, PAGE_SIZE); if (first_hole == 0) { - SetPageUptodate(page); - unlock_page(page); + folio_mark_uptodate(folio); + folio_unlock(folio); goto out; } } else if (fully_mapped) { - SetPageMappedToDisk(page); + folio_set_mappedtodisk(folio); } /* - * This page will go to BIO. Do we need to send this BIO off first? + * This folio will go to BIO. Do we need to send this BIO off first? */ if (args->bio && (args->last_block_in_bio != blocks[0] - 1)) args->bio = mpage_bio_submit(args->bio); @@ -266,7 +271,7 @@ alloc_new: if (args->bio == NULL) { if (first_hole == blocks_per_page) { if (!bdev_read_page(bdev, blocks[0] << (blkbits - 9), - page)) + &folio->page)) goto out; } args->bio = bio_alloc(bdev, bio_max_segs(args->nr_pages), op, @@ -277,7 +282,7 @@ alloc_new: } length = first_hole << blkbits; - if (bio_add_page(args->bio, page, length, 0) < length) { + if (!bio_add_folio(args->bio, folio, length, 0)) { args->bio = mpage_bio_submit(args->bio); goto alloc_new; } @@ -295,10 +300,10 @@ out: confused: if (args->bio) args->bio = mpage_bio_submit(args->bio); - if (!PageUptodate(page)) - block_read_full_folio(page_folio(page), args->get_block); + if (!folio_test_uptodate(folio)) + block_read_full_folio(folio, args->get_block); else - unlock_page(page); + folio_unlock(folio); goto out; } @@ -343,18 +348,17 @@ confused: */ void mpage_readahead(struct readahead_control *rac, get_block_t get_block) { - struct page *page; + struct folio *folio; struct mpage_readpage_args args = { .get_block = get_block, .is_readahead = true, }; - while ((page = readahead_page(rac))) { - prefetchw(&page->flags); - args.page = page; + while ((folio = readahead_folio(rac))) { + prefetchw(&folio->flags); + args.folio = folio; args.nr_pages = readahead_count(rac); args.bio = do_mpage_readpage(&args); - put_page(page); } if (args.bio) mpage_bio_submit(args.bio); @@ -367,13 +371,11 @@ EXPORT_SYMBOL(mpage_readahead); int mpage_read_folio(struct folio *folio, get_block_t get_block) { struct mpage_readpage_args args = { - .page = &folio->page, + .folio = folio, .nr_pages = 1, .get_block = get_block, }; - VM_BUG_ON_FOLIO(folio_test_large(folio), folio); - args.bio = do_mpage_readpage(&args); if (args.bio) mpage_bio_submit(args.bio); -- cgit