btrfs: Convert btrfs to read_folio

This is a "weak" conversion which converts straight back to using pages.
A full conversion should be performed at some point, hopefully by
someone familiar with the filesystem.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

fs/btrfs/ctree.h

@@ -3269,7 +3269,7 @@ void btrfs_split_delalloc_extent(struct inode *inode,
 				 struct extent_state *orig, u64 split);
 void btrfs_set_range_writeback(struct btrfs_inode *inode, u64 start, u64 end);
 vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf);
-int btrfs_readpage(struct file *file, struct page *page);
+int btrfs_read_folio(struct file *file, struct folio *folio);
 void btrfs_evict_inode(struct inode *inode);
 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc);
 struct inode *btrfs_alloc_inode(struct super_block *sb);

fs/btrfs/file.c

@@ -1307,11 +1307,12 @@ static int prepare_uptodate_page(struct inode *inode,
 				 struct page *page, u64 pos,
 				 bool force_uptodate)
 {
+	struct folio *folio = page_folio(page);
 	int ret = 0;
 
 	if (((pos & (PAGE_SIZE - 1)) || force_uptodate) &&
 	    !PageUptodate(page)) {
-		ret = btrfs_readpage(NULL, page);
+		ret = btrfs_read_folio(NULL, folio);
 		if (ret)
 			return ret;
 		lock_page(page);
@@ -1321,7 +1322,7 @@ static int prepare_uptodate_page(struct inode *inode,
 		}
 
 		/*
-		 * Since btrfs_readpage() will unlock the page before it
+		 * Since btrfs_read_folio() will unlock the folio before it
 		 * returns, there is a window where btrfs_releasepage() can be
 		 * called to release the page.  Here we check both inode
 		 * mapping and PagePrivate() to make sure the page was not

fs/btrfs/free-space-cache.c

@@ -465,7 +465,7 @@ static int io_ctl_prepare_pages(struct btrfs_io_ctl *io_ctl, bool uptodate)
 
 		io_ctl->pages[i] = page;
 		if (uptodate && !PageUptodate(page)) {
-			btrfs_readpage(NULL, page);
+			btrfs_read_folio(NULL, page_folio(page));
 			lock_page(page);
 			if (page->mapping != inode->i_mapping) {
 				btrfs_err(BTRFS_I(inode)->root->fs_info,

fs/btrfs/inode.c

@@ -4714,7 +4714,7 @@ int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len,
 		goto out_unlock;
 
 	if (!PageUptodate(page)) {
-		ret = btrfs_readpage(NULL, page);
+		ret = btrfs_read_folio(NULL, page_folio(page));
 		lock_page(page);
 		if (page->mapping != mapping) {
 			unlock_page(page);
@@ -8113,8 +8113,9 @@ static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 	return extent_fiemap(BTRFS_I(inode), fieinfo, start, len);
 }
 
-int btrfs_readpage(struct file *file, struct page *page)
+int btrfs_read_folio(struct file *file, struct folio *folio)
 {
+	struct page *page = &folio->page;
 	struct btrfs_inode *inode = BTRFS_I(page->mapping->host);
 	u64 start = page_offset(page);
 	u64 end = start + PAGE_SIZE - 1;
@@ -11357,7 +11358,7 @@ static const struct file_operations btrfs_dir_file_operations = {
  * For now we're avoiding this by dropping bmap.
  */
 static const struct address_space_operations btrfs_aops = {
-	.readpage	= btrfs_readpage,
+	.read_folio	= btrfs_read_folio,
 	.writepage	= btrfs_writepage,
 	.writepages	= btrfs_writepages,
 	.readahead	= btrfs_readahead,

fs/btrfs/ioctl.c

@@ -1359,7 +1359,7 @@ static struct page *defrag_prepare_one_page(struct btrfs_inode *inode,
 	 * make it uptodate.
 	 */
 	if (!PageUptodate(page)) {
-		btrfs_readpage(NULL, page);
+		btrfs_read_folio(NULL, page_folio(page));
 		lock_page(page);
 		if (page->mapping != mapping || !PagePrivate(page)) {
 			unlock_page(page);

fs/btrfs/relocation.c

@@ -1101,7 +1101,7 @@ int replace_file_extents(struct btrfs_trans_handle *trans,
 			continue;
 
 		/*
-		 * if we are modifying block in fs tree, wait for readpage
+		 * if we are modifying block in fs tree, wait for read_folio
 		 * to complete and drop the extent cache
 		 */
 		if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
@@ -1563,7 +1563,7 @@ static int invalidate_extent_cache(struct btrfs_root *root,
 			end = (u64)-1;
 		}
 
-		/* the lock_extent waits for readpage to complete */
+		/* the lock_extent waits for read_folio to complete */
 		lock_extent(&BTRFS_I(inode)->io_tree, start, end);
 		btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 1);
 		unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
@@ -2818,7 +2818,7 @@ static noinline_for_stack int prealloc_file_extent_cluster(
 		 * Subpage can't handle page with DIRTY but without UPTODATE
 		 * bit as it can lead to the following deadlock:
 		 *
-		 * btrfs_readpage()
+		 * btrfs_read_folio()
 		 * | Page already *locked*
 		 * |- btrfs_lock_and_flush_ordered_range()
 		 *    |- btrfs_start_ordered_extent()
@@ -2972,7 +2972,7 @@ static int relocate_one_page(struct inode *inode, struct file_ra_state *ra,
 				last_index + 1 - page_index);
 
 	if (!PageUptodate(page)) {
-		btrfs_readpage(NULL, page);
+		btrfs_read_folio(NULL, page_folio(page));
 		lock_page(page);
 		if (!PageUptodate(page)) {
 			ret = -EIO;

fs/btrfs/send.c

@@ -4991,7 +4991,7 @@ static int put_file_data(struct send_ctx *sctx, u64 offset, u32 len)
 		}
 
 		if (!PageUptodate(page)) {
-			btrfs_readpage(NULL, page);
+			btrfs_read_folio(NULL, page_folio(page));
 			lock_page(page);
 			if (!PageUptodate(page)) {
 				unlock_page(page);