hugetlbfs: remove special hugetlbfs_set_page_dirty()

Matthew Wilcox noticed that hugetlbfs_set_page_dirty always returns 0.
Instead, it should return 1 or 0 depending on the previous state of the
dirty bit.  In addition, the call to compound_head is redundant as it is
also performed in calling routine set_page_dirty.

Replace the hugetlbfs specific routine hugetlbfs_set_page_dirty with
__set_page_dirty_no_writeback as it addresses both of these issues.

Link: https://lkml.kernel.org/r/20201221192542.15732-2-mike.kravetz@oracle.comSigned-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/hugetlbfs/inode.c

@@ -952,17 +952,6 @@ static int hugetlbfs_symlink(struct user_namespace *mnt_userns,
 	return error;
 }
 
-/*
- * mark the head page dirty
- */
-static int hugetlbfs_set_page_dirty(struct page *page)
-{
-	struct page *head = compound_head(page);
-
-	SetPageDirty(head);
-	return 0;
-}
-
 static int hugetlbfs_migrate_page(struct address_space *mapping,
 				struct page *newpage, struct page *page,
 				enum migrate_mode mode)
@@ -1150,7 +1139,7 @@ static void hugetlbfs_destroy_inode(struct inode *inode)
 static const struct address_space_operations hugetlbfs_aops = {
 	.write_begin	= hugetlbfs_write_begin,
 	.write_end	= hugetlbfs_write_end,
-	.set_page_dirty	= hugetlbfs_set_page_dirty,
+	.set_page_dirty	=  __set_page_dirty_no_writeback,
 	.migratepage    = hugetlbfs_migrate_page,
 	.error_remove_page	= hugetlbfs_error_remove_page,
 };