[PATCH 15/15] sysfs: Protect sysfs_refresh_inode with inode mutex.

[Eric W. Biederman]

From: Eric W. Biederman <ebiederm@xxxxxxxxxxxxxxxxxxxxxxxxxx>

In general everything that writes to vfs inodes holds the
inode mutex, so hold the inode mutex over sysfs_refresh_inode.
The sysfs data structures don't need this but it looks like the
vfs might.

Acked-by: Serge Hallyn <serue@xxxxxxxxxx>
Acked-by: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxxxxxxxx>
---
 fs/sysfs/inode.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
index 8197e1a..75516cd 100644
--- a/fs/sysfs/inode.c
+++ b/fs/sysfs/inode.c
@@ -237,9 +237,11 @@ int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *sta
 	struct sysfs_dirent *sd = dentry->d_fsdata;
 	struct inode *inode = dentry->d_inode;
 
+	mutex_lock(&inode->i_mutex);
 	mutex_lock(&sysfs_mutex);
 	sysfs_refresh_inode(sd, inode);
 	mutex_unlock(&sysfs_mutex);
+	mutex_unlock(&inode->i_mutex);
 
 	generic_fillattr(inode, stat);
 	return 0;
@@ -349,9 +351,11 @@ int sysfs_permission(struct inode *inode, int mask)
 {
 	struct sysfs_dirent *sd = inode->i_private;
 
+	mutex_lock(&inode->i_mutex);
 	mutex_lock(&sysfs_mutex);
 	sysfs_refresh_inode(sd, inode);
 	mutex_unlock(&sysfs_mutex);
+	mutex_unlock(&inode->i_mutex);
 
 	return generic_permission(inode, mask, NULL);
 }
-- 
1.6.5.2.143.g8cc62

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/