ext4: convert fault handler to use vm_fault_t type

Return type of ext4_page_mkwrite and ext4_filemap_fault are
changed to use vm_fault_t type.

With this patch all the callers of block_page_mkwrite_return()
are changed to handle vm_fault_t. So converting the return type
of block_page_mkwrite_return() to vm_fault_t.
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Matthew Wilcox <willy@infradead.org>

fs/ext4/ext4.h

@@ -2487,8 +2487,8 @@ extern int ext4_writepage_trans_blocks(struct inode *);
 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
 extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
 			     loff_t lstart, loff_t lend);
-extern int ext4_page_mkwrite(struct vm_fault *vmf);
-extern int ext4_filemap_fault(struct vm_fault *vmf);
+extern vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf);
+extern vm_fault_t ext4_filemap_fault(struct vm_fault *vmf);
 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
 extern int ext4_get_projid(struct inode *inode, kprojid_t *projid);
 extern void ext4_da_release_space(struct inode *inode, int to_free);

fs/ext4/inode.c

@@ -6184,13 +6184,14 @@ static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
 	return !buffer_mapped(bh);
 }
 
-int ext4_page_mkwrite(struct vm_fault *vmf)
+vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf)
 {
 	struct vm_area_struct *vma = vmf->vma;
 	struct page *page = vmf->page;
 	loff_t size;
 	unsigned long len;
-	int ret;
+	int err;
+	vm_fault_t ret;
 	struct file *file = vma->vm_file;
 	struct inode *inode = file_inode(file);
 	struct address_space *mapping = inode->i_mapping;
@@ -6203,8 +6204,8 @@ int ext4_page_mkwrite(struct vm_fault *vmf)
 
 	down_read(&EXT4_I(inode)->i_mmap_sem);
 
-	ret = ext4_convert_inline_data(inode);
-	if (ret)
+	err = ext4_convert_inline_data(inode);
+	if (err)
 		goto out_ret;
 
 	/* Delalloc case is easy... */
@@ -6212,9 +6213,9 @@ int ext4_page_mkwrite(struct vm_fault *vmf)
 	    !ext4_should_journal_data(inode) &&
 	    !ext4_nonda_switch(inode->i_sb)) {
 		do {
-			ret = block_page_mkwrite(vma, vmf,
+			err = block_page_mkwrite(vma, vmf,
 						   ext4_da_get_block_prep);
-		} while (ret == -ENOSPC &&
+		} while (err == -ENOSPC &&
 		       ext4_should_retry_alloc(inode->i_sb, &retries));
 		goto out_ret;
 	}
@@ -6259,8 +6260,8 @@ int ext4_page_mkwrite(struct vm_fault *vmf)
 		ret = VM_FAULT_SIGBUS;
 		goto out;
 	}
-	ret = block_page_mkwrite(vma, vmf, get_block);
-	if (!ret && ext4_should_journal_data(inode)) {
+	err = block_page_mkwrite(vma, vmf, get_block);
+	if (!err && ext4_should_journal_data(inode)) {
 		if (ext4_walk_page_buffers(handle, page_buffers(page), 0,
 			  PAGE_SIZE, NULL, do_journal_get_write_access)) {
 			unlock_page(page);
@@ -6271,24 +6272,24 @@ int ext4_page_mkwrite(struct vm_fault *vmf)
 		ext4_set_inode_state(inode, EXT4_STATE_JDATA);
 	}
 	ext4_journal_stop(handle);
-	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
+	if (err == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
 		goto retry_alloc;
 out_ret:
-	ret = block_page_mkwrite_return(ret);
+	ret = block_page_mkwrite_return(err);
 out:
 	up_read(&EXT4_I(inode)->i_mmap_sem);
 	sb_end_pagefault(inode->i_sb);
 	return ret;
 }
 
-int ext4_filemap_fault(struct vm_fault *vmf)
+vm_fault_t ext4_filemap_fault(struct vm_fault *vmf)
 {
 	struct inode *inode = file_inode(vmf->vma->vm_file);
-	int err;
+	vm_fault_t ret;
 
 	down_read(&EXT4_I(inode)->i_mmap_sem);
-	err = filemap_fault(vmf);
+	ret = filemap_fault(vmf);
 	up_read(&EXT4_I(inode)->i_mmap_sem);
 
-	return err;
+	return ret;
 }

include/linux/buffer_head.h

@@ -242,7 +242,7 @@ int block_commit_write(struct page *page, unsigned from, unsigned to);
 int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
 				get_block_t get_block);
 /* Convert errno to return value from ->page_mkwrite() call */
-static inline int block_page_mkwrite_return(int err)
+static inline vm_fault_t block_page_mkwrite_return(int err)
 {
 	if (err == 0)
 		return VM_FAULT_LOCKED;