ext4: convert from atomic_t to refcount_t on ext4_io_end->count
refcount_t type and corresponding API can protect refcounters from
accidental underflow and overflow and further use-after-free situations.
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/1626674355-55795-1-git-send-email-xiyuyang19@fudan.edu.cn
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 3825195..404dd50 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -17,6 +17,7 @@
#ifndef _EXT4_H
#define _EXT4_H
+#include <linux/refcount.h>
#include <linux/types.h>
#include <linux/blkdev.h>
#include <linux/magic.h>
@@ -241,7 +242,7 @@ typedef struct ext4_io_end {
struct bio *bio; /* Linked list of completed
* bios covering the extent */
unsigned int flag; /* unwritten or not */
- atomic_t count; /* reference counter */
+ refcount_t count; /* reference counter */
struct list_head list_vec; /* list of ext4_io_end_vec */
} ext4_io_end_t;