Btrfs: fix btrfs_release_extent_buffer_page with the right usage of num_extent_pages
num_extent_pages returns the number of pages in the specific range, not
the index of the last page in the eb range.
btrfs_release_extent_buffer_page is called with start_idx set 0 in current
codes, so it's not a problem yet. But the logic is indeed wrong.
Fix it here.
Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index aeb98ce..455daec2 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3981,11 +3981,13 @@
unsigned long start_idx)
{
unsigned long index;
+ unsigned long num_pages;
struct page *page;
BUG_ON(extent_buffer_under_io(eb));
- index = num_extent_pages(eb->start, eb->len);
+ num_pages = num_extent_pages(eb->start, eb->len);
+ index = start_idx + num_pages;
if (start_idx >= index)
return;