fs: Convert is_partially_uptodate to folios

Since the uptodate property is maintained on a per-folio basis, the
is_partially_uptodate method should also take a folio.  Fix the types
at the same time so it's clear that it returns true/false and takes
the count in bytes, not blocks.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs
Tested-by: David Howells <dhowells@redhat.com> # afs

Documentation/filesystems/locking.rst

@@ -258,7 +258,7 @@ prototypes::
 	int (*migratepage)(struct address_space *, struct page *, struct page *);
 	void (*putback_page) (struct page *);
 	int (*launder_page)(struct page *);
-	int (*is_partially_uptodate)(struct page *, unsigned long, unsigned long);
+	bool (*is_partially_uptodate)(struct folio *, size_t from, size_t count);
 	int (*error_remove_page)(struct address_space *, struct page *);
 	int (*swap_activate)(struct file *);
 	int (*swap_deactivate)(struct file *);

Documentation/filesystems/vfs.rst

@@ -747,8 +747,8 @@ cache in your filesystem.  The following members are defined:
 		void (*putback_page) (struct page *);
 		int (*launder_page) (struct page *);
 
-		int (*is_partially_uptodate) (struct page *, unsigned long,
-					      unsigned long);
+		bool (*is_partially_uptodate) (struct folio *, size_t from,
+					       size_t count);
 		void (*is_dirty_writeback) (struct page *, bool *, bool *);
 		int (*error_remove_page) (struct mapping *mapping, struct page *page);
 		int (*swap_activate)(struct file *);
@@ -937,9 +937,9 @@ cache in your filesystem.  The following members are defined:
 
 ``is_partially_uptodate``
 	Called by the VM when reading a file through the pagecache when
-	the underlying blocksize != pagesize.  If the required block is
-	up to date then the read can complete without needing the IO to
-	bring the whole page up to date.
+	the underlying blocksize is smaller than the size of the folio.
+	If the required block is up to date then the read can complete
+	without needing I/O to bring the whole page up to date.
 
 ``is_dirty_writeback``
 	Called by the VM when attempting to reclaim a page.  The VM uses

fs/buffer.c

@@ -2206,29 +2206,27 @@ int generic_write_end(struct file *file, struct address_space *mapping,
 EXPORT_SYMBOL(generic_write_end);
 
 /*
- * block_is_partially_uptodate checks whether buffers within a page are
+ * block_is_partially_uptodate checks whether buffers within a folio are
  * uptodate or not.
  *
- * Returns true if all buffers which correspond to a file portion
- * we want to read are uptodate.
+ * Returns true if all buffers which correspond to the specified part
+ * of the folio are uptodate.
  */
-int block_is_partially_uptodate(struct page *page, unsigned long from,
-					unsigned long count)
+bool block_is_partially_uptodate(struct folio *folio, size_t from, size_t count)
 {
 	unsigned block_start, block_end, blocksize;
 	unsigned to;
 	struct buffer_head *bh, *head;
-	int ret = 1;
-
-	if (!page_has_buffers(page))
-		return 0;
+	bool ret = true;
 
-	head = page_buffers(page);
+	head = folio_buffers(folio);
+	if (!head)
+		return false;
 	blocksize = head->b_size;
-	to = min_t(unsigned, PAGE_SIZE - from, count);
+	to = min_t(unsigned, folio_size(folio) - from, count);
 	to = from + to;
-	if (from < blocksize && to > PAGE_SIZE - blocksize)
-		return 0;
+	if (from < blocksize && to > folio_size(folio) - blocksize)
+		return false;
 
 	bh = head;
 	block_start = 0;
@@ -2236,7 +2234,7 @@ int block_is_partially_uptodate(struct page *page, unsigned long from,
 		block_end = block_start + blocksize;
 		if (block_end > from && block_start < to) {
 			if (!buffer_uptodate(bh)) {
-				ret = 0;
+				ret = false;
 				break;
 			}
 			if (block_end >= to)

fs/iomap/buffered-io.c

@@ -424,37 +424,33 @@ void iomap_readahead(struct readahead_control *rac, const struct iomap_ops *ops)
 EXPORT_SYMBOL_GPL(iomap_readahead);
 
 /*
- * iomap_is_partially_uptodate checks whether blocks within a page are
+ * iomap_is_partially_uptodate checks whether blocks within a folio are
  * uptodate or not.
  *
- * Returns true if all blocks which correspond to a file portion
- * we want to read within the page are uptodate.
+ * Returns true if all blocks which correspond to the specified part
+ * of the folio are uptodate.
  */
-int
-iomap_is_partially_uptodate(struct page *page, unsigned long from,
-		unsigned long count)
+bool iomap_is_partially_uptodate(struct folio *folio, size_t from, size_t count)
 {
-	struct folio *folio = page_folio(page);
 	struct iomap_page *iop = to_iomap_page(folio);
-	struct inode *inode = page->mapping->host;
-	unsigned len, first, last;
-	unsigned i;
+	struct inode *inode = folio->mapping->host;
+	size_t len;
+	unsigned first, last, i;
 
-	/* Limit range to one page */
-	len = min_t(unsigned, PAGE_SIZE - from, count);
+	if (!iop)
+		return false;
+
+	/* Limit range to this folio */
+	len = min(folio_size(folio) - from, count);
 
 	/* First and last blocks in range within page */
 	first = from >> inode->i_blkbits;
 	last = (from + len - 1) >> inode->i_blkbits;
 
-	if (iop) {
-		for (i = first; i <= last; i++)
-			if (!test_bit(i, iop->uptodate))
-				return 0;
-		return 1;
-	}
-
-	return 0;
+	for (i = first; i <= last; i++)
+		if (!test_bit(i, iop->uptodate))
+			return false;
+	return true;
 }
 EXPORT_SYMBOL_GPL(iomap_is_partially_uptodate);
 

include/linux/buffer_head.h

@@ -225,8 +225,7 @@ int __block_write_full_page(struct inode *inode, struct page *page,
 			get_block_t *get_block, struct writeback_control *wbc,
 			bh_end_io_t *handler);
 int block_read_full_page(struct page*, get_block_t*);
-int block_is_partially_uptodate(struct page *page, unsigned long from,
-				unsigned long count);
+bool block_is_partially_uptodate(struct folio *, size_t from, size_t count);
 int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len,
 		unsigned flags, struct page **pagep, get_block_t *get_block);
 int __block_write_begin(struct page *page, loff_t pos, unsigned len,

include/linux/fs.h

@@ -400,8 +400,8 @@ struct address_space_operations {
 	bool (*isolate_page)(struct page *, isolate_mode_t);
 	void (*putback_page)(struct page *);
 	int (*launder_page) (struct page *);
-	int (*is_partially_uptodate) (struct page *, unsigned long,
-					unsigned long);
+	bool (*is_partially_uptodate) (struct folio *, size_t from,
+			size_t count);
 	void (*is_dirty_writeback) (struct page *, bool *, bool *);
 	int (*error_remove_page)(struct address_space *, struct page *);
 

include/linux/iomap.h

@@ -227,8 +227,7 @@ ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
 		const struct iomap_ops *ops);
 int iomap_readpage(struct page *page, const struct iomap_ops *ops);
 void iomap_readahead(struct readahead_control *, const struct iomap_ops *ops);
-int iomap_is_partially_uptodate(struct page *page, unsigned long from,
-		unsigned long count);
+bool iomap_is_partially_uptodate(struct folio *, size_t from, size_t count);
 int iomap_releasepage(struct page *page, gfp_t gfp_mask);
 void iomap_invalidate_folio(struct folio *folio, size_t offset, size_t len);
 void iomap_invalidatepage(struct page *page, unsigned int offset,

mm/filemap.c

@@ -2452,7 +2452,7 @@ static bool filemap_range_uptodate(struct address_space *mapping,
 		pos -= folio_pos(folio);
 	}
 
-	return mapping->a_ops->is_partially_uptodate(&folio->page, pos, count);
+	return mapping->a_ops->is_partially_uptodate(folio, pos, count);
 }
 
 static int filemap_update_page(struct kiocb *iocb,
@@ -2844,7 +2844,7 @@ static inline loff_t folio_seek_hole_data(struct xa_state *xas,
 	offset = offset_in_folio(folio, start) & ~(bsz - 1);
 
 	do {
-		if (ops->is_partially_uptodate(&folio->page, offset, bsz) ==
+		if (ops->is_partially_uptodate(folio, offset, bsz) ==
 							seek_data)
 			break;
 		start = (start + bsz) & ~(bsz - 1);