From f76142a8eef546c8e4623fb6930472466ea2458d Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@canonical.com>
Date: Tue, 2 Apr 2013 10:12:26 +0800
Subject: [PATCH] --- yaml --- r: 363247 b: refs/heads/master c:
 f7db5e7660b122142410dcf36ba903c73d473250 h: refs/heads/master i:   363245:
 ec19cb9094b778632d354592ed79a3992ad3d4fc   363243:
 4f4e81d1e7a21dc4c01c39b02e48e3e860102dc9   363239:
 0e2a2de8f12b472e4e484cc39b2a2ca284938040   363231:
 818bae2780a6a3d12a4b434f1637ef807d84f294 v: v3

---
 [refs]               |  2 +-
 trunk/fs/sysfs/dir.c | 15 +++++++++++----
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/[refs] b/[refs]
index fe548da7b82a..3b9b734c1544 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 0f8b1a0204a12441cddbbf5be31e6338e0b8da1c
+refs/heads/master: f7db5e7660b122142410dcf36ba903c73d473250
diff --git a/trunk/fs/sysfs/dir.c b/trunk/fs/sysfs/dir.c
index c6f54abe9852..1bf016b5e88f 100644
--- a/trunk/fs/sysfs/dir.c
+++ b/trunk/fs/sysfs/dir.c
@@ -999,6 +999,7 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
 	enum kobj_ns_type type;
 	const void *ns;
 	ino_t ino;
+	loff_t off;
 
 	type = sysfs_ns_type(parent_sd);
 	ns = sysfs_info(dentry->d_sb)->ns[type];
@@ -1021,6 +1022,7 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
 			return 0;
 	}
 	mutex_lock(&sysfs_mutex);
+	off = filp->f_pos;
 	for (pos = sysfs_dir_pos(ns, parent_sd, filp->f_pos, pos);
 	     pos;
 	     pos = sysfs_dir_next_pos(ns, parent_sd, filp->f_pos, pos)) {
@@ -1032,19 +1034,24 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
 		len = strlen(name);
 		ino = pos->s_ino;
 		type = dt_type(pos);
-		filp->f_pos = pos->s_hash;
+		off = filp->f_pos = pos->s_hash;
 		filp->private_data = sysfs_get(pos);
 
 		mutex_unlock(&sysfs_mutex);
-		ret = filldir(dirent, name, len, filp->f_pos, ino, type);
+		ret = filldir(dirent, name, len, off, ino, type);
 		mutex_lock(&sysfs_mutex);
 		if (ret < 0)
 			break;
 	}
 	mutex_unlock(&sysfs_mutex);
-	if ((filp->f_pos > 1) && !pos) { /* EOF */
-		filp->f_pos = INT_MAX;
+
+	/* don't reference last entry if its refcount is dropped */
+	if (!pos) {
 		filp->private_data = NULL;
+
+		/* EOF and not changed as 0 or 1 in read/write path */
+		if (off == filp->f_pos && off > 1)
+			filp->f_pos = INT_MAX;
 	}
 	return 0;
 }