From c7522635c7e4810d82748de2fe70aebef6157071 Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm@aristanetworks.com>
Date: Tue, 18 May 2010 12:58:33 -0700
Subject: [PATCH] --- yaml --- r: 196060 b: refs/heads/master c:
 68d75ed4b84a0806ecd4bc14da4759713b23a532 h: refs/heads/master v: v3

---
 [refs]                 |  2 +-
 trunk/fs/sysfs/mount.c | 11 ++++++++---
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index f91386b7545b..e4253592b082 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 27eabc7cb4b357c68e4ce77d0b014f7a23add752
+refs/heads/master: 68d75ed4b84a0806ecd4bc14da4759713b23a532
diff --git a/trunk/fs/sysfs/mount.c b/trunk/fs/sysfs/mount.c
index 1afa32ba242c..281c0c9bc39f 100644
--- a/trunk/fs/sysfs/mount.c
+++ b/trunk/fs/sysfs/mount.c
@@ -138,6 +138,9 @@ static void sysfs_kill_sb(struct super_block *sb)
 {
 	struct sysfs_super_info *info = sysfs_info(sb);
 
+	/* Remove the superblock from fs_supers/s_instances
+	 * so we can't find it, before freeing sysfs_super_info.
+	 */
 	kill_anon_super(sb);
 	kfree(info);
 }
@@ -156,9 +159,11 @@ void sysfs_exit_ns(enum kobj_ns_type type, const void *ns)
 	spin_lock(&sb_lock);
 	list_for_each_entry(sb, &sysfs_fs_type.fs_supers, s_instances) {
 		struct sysfs_super_info *info = sysfs_info(sb);
-		/* Ignore superblocks that are in the process of unmounting */
-		if (sb->s_count <= S_BIAS)
-			continue;
+		/*
+		 * If we see a superblock on the fs_supers/s_instances
+		 * list the unmount has not completed and sb->s_fs_info
+		 * points to a valid struct sysfs_super_info.
+		 */
 		/* Ignore superblocks with the wrong ns */
 		if (info->ns[type] != ns)
 			continue;