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

Eric W. Biederman
2009-11-08T07:27:42Z

From: Eric W. Biederman <ebiederm@maxwell.aristanetworks.com>

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@us.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
---
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