btrfs: simplify btrfs_page_exists_in_range()

this removes the last usage of radix_tree_gang_lookup_slot()

1 files changed, 7 insertions, 62 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 4421954720b8..75832fd13ac6 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7376,71 +7376,16 @@ out:
 
 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
 {
-	struct radix_tree_root *root = &inode->i_mapping->page_tree;
-	int found = false;
-	void **pagep = NULL;
-	struct page *page = NULL;
-	int start_idx;
-	int end_idx;
-
-	start_idx = start >> PAGE_SHIFT;
-
-	/*
-	 * end is the last byte in the last page.  end == start is legal
-	 */
-	end_idx = end >> PAGE_SHIFT;
-
-	rcu_read_lock();
-
-	/* Most of the code in this while loop is lifted from
-	 * find_get_page.  It's been modified to begin searching from a
-	 * page and return just the first page found in that range.  If the
-	 * found idx is less than or equal to the end idx then we know that
-	 * a page exists.  If no pages are found or if those pages are
-	 * outside of the range then we're fine (yay!) */
-	while (page == NULL &&
-	       radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
-		page = radix_tree_deref_slot(pagep);
-		if (unlikely(!page))
-			break;
-
-		if (radix_tree_exception(page)) {
-			if (radix_tree_deref_retry(page)) {
-				page = NULL;
-				continue;
-			}
-			/*
-			 * Otherwise, shmem/tmpfs must be storing a swap entry
-			 * here as an exceptional entry: so return it without
-			 * attempting to raise page count.
-			 */
-			page = NULL;
-			break; /* TODO: Is this relevant for this use case? */
-		}
-
-		if (!page_cache_get_speculative(page)) {
-			page = NULL;
-			continue;
-		}
-
-		/*
-		 * Has the page moved?
-		 * This is part of the lockless pagecache protocol. See
-		 * include/linux/pagemap.h for details.
-		 */
-		if (unlikely(page != *pagep)) {
-			put_page(page);
-			page = NULL;
-		}
-	}
+	struct page *page;
+	int found;
 
-	if (page) {
-		if (page->index <= end_idx)
-			found = true;
+	found = __find_get_pages(inode->i_mapping,
+				 start >> PAGE_SHIFT,
+				 end  >> PAGE_SHIFT,
+				 1, &page, NULL, 0) != 0;
+	if (found)
 		put_page(page);
-	}
 
-	rcu_read_unlock();
 	return found;
 }