[PATCH 15/13] sysfs: Protect sysfs_refresh_inode with inode mutex.

From: Eric W. Biederman
Date: Wed Nov 04 2009 - 07:05:20 EST



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.

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 e2595a7..ad549f5 100644
--- a/fs/sysfs/inode.c
+++ b/fs/sysfs/inode.c
@@ -240,9 +240,11 @@ 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;
@@ -353,9 +355,11 @@ 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

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