Merge tag 'iomap-5.17' of git://git.infradead.org/users/willy/linux

Pull iomap updates from Matthew Wilcox:
 "Convert xfs/iomap to use folios.

  This should be all that is needed for XFS to use large folios. There
  is no code in this pull request to create large folios, but no
  additional changes should be needed to XFS or iomap once they are
  created.

  Usually this would have come from Darrick, and we had intended that it
  would come that route. Between the holidays and various things which
  Darrick needed to work on, he asked if I could send things directly.

  There weren't any other iomap patches pending for this release, which
  probably also played a role"

* tag 'iomap-5.17' of git://git.infradead.org/users/willy/linux: (26 commits)
  iomap: Inline __iomap_zero_iter into its caller
  xfs: Support large folios
  iomap: Support large folios in invalidatepage
  iomap: Convert iomap_migrate_page() to use folios
  iomap: Convert iomap_add_to_ioend() to take a folio
  iomap: Simplify iomap_do_writepage()
  iomap: Simplify iomap_writepage_map()
  iomap,xfs: Convert ->discard_page to ->discard_folio
  iomap: Convert iomap_write_end_inline to take a folio
  iomap: Convert iomap_write_begin() and iomap_write_end() to folios
  iomap: Convert __iomap_zero_iter to use a folio
  iomap: Allow iomap_write_begin() to be called with the full length
  iomap: Convert iomap_page_mkwrite to use a folio
  iomap: Convert readahead and readpage to use a folio
  iomap: Convert iomap_read_inline_data to take a folio
  iomap: Use folio offsets instead of page offsets
  iomap: Convert bio completions to use folios
  iomap: Pass the iomap_page into iomap_set_range_uptodate
  iomap: Add iomap_invalidate_folio
  iomap: Convert iomap_releasepage to use a folio
  ...

Author: torvalds

Documentation/core-api/kernel-api.rst

@@ -279,6 +279,7 @@ Accounting Framework
 Block Devices
 =============
 
+.. kernel-doc:: include/linux/bio.h
 .. kernel-doc:: block/blk-core.c
    :export:
 

block/bio.c

@@ -1035,6 +1035,28 @@ int bio_add_page(struct bio *bio, struct page *page,
 }
 EXPORT_SYMBOL(bio_add_page);
 
+/**
+ * bio_add_folio - Attempt to add part of a folio to a bio.
+ * @bio: BIO to add to.
+ * @folio: Folio to add.
+ * @len: How many bytes from the folio to add.
+ * @off: First byte in this folio to add.
+ *
+ * Filesystems that use folios can call this function instead of calling
+ * bio_add_page() for each page in the folio.  If @off is bigger than
+ * PAGE_SIZE, this function can create a bio_vec that starts in a page
+ * after the bv_page.  BIOs do not support folios that are 4GiB or larger.
+ *
+ * Return: Whether the addition was successful.
+ */
+bool bio_add_folio(struct bio *bio, struct folio *folio, size_t len,
+		   size_t off)
+{
+	if (len > UINT_MAX || off > UINT_MAX)
+		return 0;
+	return bio_add_page(bio, &folio->page, len, off) > 0;
+}
+
 void __bio_release_pages(struct bio *bio, bool mark_dirty)
 {
 	struct bvec_iter_all iter_all;

fs/buffer.c

@@ -1969,34 +1969,34 @@ iomap_to_bh(struct inode *inode, sector_t block, struct buffer_head *bh,
 	}
 }
 
-int __block_write_begin_int(struct page *page, loff_t pos, unsigned len,
+int __block_write_begin_int(struct folio *folio, loff_t pos, unsigned len,
 		get_block_t *get_block, const struct iomap *iomap)
 {
 	unsigned from = pos & (PAGE_SIZE - 1);
 	unsigned to = from + len;
-	struct inode *inode = page->mapping->host;
+	struct inode *inode = folio->mapping->host;
 	unsigned block_start, block_end;
 	sector_t block;
 	int err = 0;
 	unsigned blocksize, bbits;
 	struct buffer_head *bh, *head, *wait[2], **wait_bh=wait;
 
-	BUG_ON(!PageLocked(page));
+	BUG_ON(!folio_test_locked(folio));
 	BUG_ON(from > PAGE_SIZE);
 	BUG_ON(to > PAGE_SIZE);
 	BUG_ON(from > to);
 
-	head = create_page_buffers(page, inode, 0);
+	head = create_page_buffers(&folio->page, inode, 0);
 	blocksize = head->b_size;
 	bbits = block_size_bits(blocksize);
 
-	block = (sector_t)page->index << (PAGE_SHIFT - bbits);
+	block = (sector_t)folio->index << (PAGE_SHIFT - bbits);
 
 	for(bh = head, block_start = 0; bh != head || !block_start;
 	    block++, block_start=block_end, bh = bh->b_this_page) {
 		block_end = block_start + blocksize;
 		if (block_end <= from || block_start >= to) {
-			if (PageUptodate(page)) {
+			if (folio_test_uptodate(folio)) {
 				if (!buffer_uptodate(bh))
 					set_buffer_uptodate(bh);
 			}
@@ -2016,20 +2016,20 @@ int __block_write_begin_int(struct page *page, loff_t pos, unsigned len,
 
 			if (buffer_new(bh)) {
 				clean_bdev_bh_alias(bh);
-				if (PageUptodate(page)) {
+				if (folio_test_uptodate(folio)) {
 					clear_buffer_new(bh);
 					set_buffer_uptodate(bh);
 					mark_buffer_dirty(bh);
 					continue;
 				}
 				if (block_end > to || block_start < from)
-					zero_user_segments(page,
+					folio_zero_segments(folio,
 						to, block_end,
 						block_start, from);
 				continue;
 			}
 		}
-		if (PageUptodate(page)) {
+		if (folio_test_uptodate(folio)) {
 			if (!buffer_uptodate(bh))
 				set_buffer_uptodate(bh);
 			continue; 
@@ -2050,14 +2050,15 @@ int __block_write_begin_int(struct page *page, loff_t pos, unsigned len,
 			err = -EIO;
 	}
 	if (unlikely(err))
-		page_zero_new_buffers(page, from, to);
+		page_zero_new_buffers(&folio->page, from, to);
 	return err;
 }
 
 int __block_write_begin(struct page *page, loff_t pos, unsigned len,
 		get_block_t *get_block)
 {
-	return __block_write_begin_int(page, pos, len, get_block, NULL);
+	return __block_write_begin_int(page_folio(page), pos, len, get_block,
+				       NULL);
 }
 EXPORT_SYMBOL(__block_write_begin);
 

fs/internal.h

@@ -37,7 +37,7 @@ static inline int emergency_thaw_bdev(struct super_block *sb)
 /*
  * buffer.c
  */
-int __block_write_begin_int(struct page *page, loff_t pos, unsigned len,
+int __block_write_begin_int(struct folio *folio, loff_t pos, unsigned len,
 		get_block_t *get_block, const struct iomap *iomap);
 
 /*