2018-05-18 15:50:52

by Hatayama, Daisuke

[permalink] [raw]
Subject: [PATCH] kernfs: fix dentry unexpected skip

kernfs_dir_next_pos() overlooks the situation that the dentry
corresponding to a given pos object has already been inactive. Hence,
when kernfs_dir_pos() returns the dentry with a hash value larger than
the original one, kernfs_dir_next_pos() returns the dentry next to the
one returned by kernfs_dir_pos(). As a result, the dentry returned by
kernfs_dir_pos() is skipped.

To fix this issue, try to find a next node only when the returned
object has a hash value equal to or smaller than the original one.

Signed-off-by: HATAYAMA Daisuke <[email protected]>
Suggested-by: Toshiyuki Okajima <[email protected]>
Cc: Eric W. Biederman <[email protected]>
---
fs/kernfs/dir.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 89d1dc1..8a2f49c 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -1622,7 +1622,7 @@ static int kernfs_dir_fop_release(struct inode *inode, struct file *filp)
struct kernfs_node *parent, ino_t ino, struct kernfs_node *pos)
{
pos = kernfs_dir_pos(ns, parent, ino, pos);
- if (pos) {
+ if (pos && pos->hash <= ino) {
do {
struct rb_node *node = rb_next(&pos->rb);
if (!node)
--
1.7.1