readahead: remove one unnecessary radix tree lookup
(hit_readahead_marker != 0) means the page at @offset is present, so we
can search for non-present page starting from @offset+1.
Reported-by: Xu Chenfeng <xcf@ustc.edu.cn>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/readahead.c b/mm/readahead.c
index bd0f0e8..5673115 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -395,7 +395,7 @@
pgoff_t start;
rcu_read_lock();
- start = radix_tree_next_hole(&mapping->page_tree, offset,max+1);
+ start = radix_tree_next_hole(&mapping->page_tree, offset+1,max);
rcu_read_unlock();
if (!start || start - offset > max)