buffer: Convert __block_write_begin() to take a folio

Almost all callers have a folio now, so change __block_write_begin()
to take a folio and remove a call to compound_head().

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

fs/buffer.c

@@ -2168,11 +2168,10 @@ int __block_write_begin_int(struct folio *folio, loff_t pos, unsigned len,
 	return err;
 }
 
-int __block_write_begin(struct page *page, loff_t pos, unsigned len,
+int __block_write_begin(struct folio *folio, loff_t pos, unsigned len,
 		get_block_t *get_block)
 {
-	return __block_write_begin_int(page_folio(page), pos, len, get_block,
+	return __block_write_begin_int(folio, pos, len, get_block, NULL);
-				       NULL);
 }
 EXPORT_SYMBOL(__block_write_begin);
 

fs/ext2/dir.c

@@ -434,7 +434,7 @@ int ext2_inode_by_name(struct inode *dir, const struct qstr *child, ino_t *ino)
 
 static int ext2_prepare_chunk(struct folio *folio, loff_t pos, unsigned len)
 {
-	return __block_write_begin(&folio->page, pos, len, ext2_get_block);
+	return __block_write_begin(folio, pos, len, ext2_get_block);
 }
 
 static int ext2_handle_dirsync(struct inode *dir)

fs/ext4/inline.c

@@ -601,10 +601,10 @@ retry:
 		goto out;
 
 	if (ext4_should_dioread_nolock(inode)) {
-		ret = __block_write_begin(&folio->page, from, to,
+		ret = __block_write_begin(folio, from, to,
 					  ext4_get_block_unwritten);
 	} else
-		ret = __block_write_begin(&folio->page, from, to, ext4_get_block);
+		ret = __block_write_begin(folio, from, to, ext4_get_block);
 
 	if (!ret && ext4_should_journal_data(inode)) {
 		ret = ext4_walk_page_buffers(handle, inode,
@@ -856,7 +856,7 @@ static int ext4_da_convert_inline_data_to_extent(struct address_space *mapping,
 			goto out;
 	}
 
-	ret = __block_write_begin(&folio->page, 0, inline_size,
+	ret = __block_write_begin(folio, 0, inline_size,
 				  ext4_da_get_block_prep);
 	if (ret) {
 		up_read(&EXT4_I(inode)->xattr_sem);

fs/ext4/inode.c

@@ -1224,10 +1224,10 @@ retry_journal:
 		ret = ext4_block_write_begin(folio, pos, len, ext4_get_block);
 #else
 	if (ext4_should_dioread_nolock(inode))
-		ret = __block_write_begin(&folio->page, pos, len,
+		ret = __block_write_begin(folio, pos, len,
 					  ext4_get_block_unwritten);
 	else
-		ret = __block_write_begin(&folio->page, pos, len, ext4_get_block);
+		ret = __block_write_begin(folio, pos, len, ext4_get_block);
 #endif
 	if (!ret && ext4_should_journal_data(inode)) {
 		ret = ext4_walk_page_buffers(handle, inode,
@@ -2962,7 +2962,7 @@ retry:
 #ifdef CONFIG_FS_ENCRYPTION
 	ret = ext4_block_write_begin(folio, pos, len, ext4_da_get_block_prep);
 #else
-	ret = __block_write_begin(&folio->page, pos, len, ext4_da_get_block_prep);
+	ret = __block_write_begin(folio, pos, len, ext4_da_get_block_prep);
 #endif
 	if (ret < 0) {
 		folio_unlock(folio);
@@ -6216,7 +6216,7 @@ retry_alloc:
 		if (folio_pos(folio) + len > size)
 			len = size - folio_pos(folio);
 
-		err = __block_write_begin(&folio->page, 0, len, ext4_get_block);
+		err = __block_write_begin(folio, 0, len, ext4_get_block);
 		if (!err) {
 			ret = VM_FAULT_SIGBUS;
 			if (ext4_journal_folio_buffers(handle, folio, len))

fs/minix/inode.c

@@ -429,7 +429,7 @@ static int minix_read_folio(struct file *file, struct folio *folio)
 
 int minix_prepare_chunk(struct folio *folio, loff_t pos, unsigned len)
 {
-	return __block_write_begin(&folio->page, pos, len, minix_get_block);
+	return __block_write_begin(folio, pos, len, minix_get_block);
 }
 
 static void minix_write_failed(struct address_space *mapping, loff_t to)

fs/nilfs2/dir.c

@@ -83,7 +83,7 @@ static int nilfs_prepare_chunk(struct folio *folio, unsigned int from,
 {
 	loff_t pos = folio_pos(folio) + from;
 
-	return __block_write_begin(&folio->page, pos, to - from, nilfs_get_block);
+	return __block_write_begin(folio, pos, to - from, nilfs_get_block);
 }
 
 static void nilfs_commit_chunk(struct folio *folio,

fs/ocfs2/file.c

@@ -804,7 +804,7 @@ static int ocfs2_write_zero_page(struct inode *inode, u64 abs_from,
 		 * __block_write_begin and block_commit_write to zero the
 		 * whole block.
 		 */
-		ret = __block_write_begin(&folio->page, block_start + 1, 0,
+		ret = __block_write_begin(folio, block_start + 1, 0,
 					  ocfs2_get_block);
 		if (ret < 0) {
 			mlog_errno(ret);

fs/reiserfs/inode.c

@@ -2198,7 +2198,7 @@ static int grab_tail_page(struct inode *inode,
 	/* start within the page of the last block in the file */
 	start = (offset / blocksize) * blocksize;
 
-	error = __block_write_begin(&folio->page, start, offset - start,
+	error = __block_write_begin(folio, start, offset - start,
 				    reiserfs_get_block_create_0);
 	if (error)
 		goto unlock;
@@ -2762,7 +2762,7 @@ static int reiserfs_write_begin(struct file *file,
 		old_ref = th->t_refcount;
 		th->t_refcount++;
 	}
-	ret = __block_write_begin(&folio->page, pos, len, reiserfs_get_block);
+	ret = __block_write_begin(folio, pos, len, reiserfs_get_block);
 	if (ret && reiserfs_transaction_running(inode->i_sb)) {
 		struct reiserfs_transaction_handle *th = current->journal_info;
 		/*
@@ -2822,7 +2822,7 @@ int __reiserfs_write_begin(struct page *page, unsigned from, unsigned len)
 		th->t_refcount++;
 	}
 
-	ret = __block_write_begin(page, from, len, reiserfs_get_block);
+	ret = __block_write_begin(page_folio(page), from, len, reiserfs_get_block);
 	if (ret && reiserfs_transaction_running(inode->i_sb)) {
 		struct reiserfs_transaction_handle *th = current->journal_info;
 		/*

fs/sysv/itree.c

@@ -468,7 +468,7 @@ static int sysv_read_folio(struct file *file, struct folio *folio)
 
 int sysv_prepare_chunk(struct folio *folio, loff_t pos, unsigned len)
 {
-	return __block_write_begin(&folio->page, pos, len, get_block);
+	return __block_write_begin(folio, pos, len, get_block);
 }
 
 static void sysv_write_failed(struct address_space *mapping, loff_t to)

fs/udf/file.c

@@ -62,7 +62,7 @@ static vm_fault_t udf_page_mkwrite(struct vm_fault *vmf)
 		end = size & ~PAGE_MASK;
 	else
 		end = PAGE_SIZE;
-	err = __block_write_begin(&folio->page, 0, end, udf_get_block);
+	err = __block_write_begin(folio, 0, end, udf_get_block);
 	if (err) {
 		folio_unlock(folio);
 		ret = vmf_fs_error(err);

fs/ufs/inode.c

@@ -481,7 +481,7 @@ static int ufs_read_folio(struct file *file, struct folio *folio)
 
 int ufs_prepare_chunk(struct folio *folio, loff_t pos, unsigned len)
 {
-	return __block_write_begin(&folio->page, pos, len, ufs_getfrag_block);
+	return __block_write_begin(folio, pos, len, ufs_getfrag_block);
 }
 
 static void ufs_truncate_blocks(struct inode *);

include/linux/buffer_head.h

@@ -259,7 +259,7 @@ int block_read_full_folio(struct folio *, get_block_t *);
 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,
 		struct folio **foliop, get_block_t *get_block);
-int __block_write_begin(struct page *page, loff_t pos, unsigned len,
+int __block_write_begin(struct folio *folio, loff_t pos, unsigned len,
 		get_block_t *get_block);
 int block_write_end(struct file *, struct address_space *,
 				loff_t, unsigned len, unsigned copied,