Driver Core: devtmpfs: do not remove non-kernel-created directories

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 880a203..c7f5c08 100644 (file)
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -76,37 +76,26 @@ static int dev_mkdir(const char *name, mode_t mode)
        dentry = lookup_create(&nd, 1);
        if (!IS_ERR(dentry)) {
                err = vfs_mkdir(nd.path.dentry->d_inode, dentry, mode);
+               if (!err)
+                       /* mark as kernel-created inode */
+                       dentry->d_inode->i_private = &dev_mnt;
                dput(dentry);
        } else {
                err = PTR_ERR(dentry);
        }
-       mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
 
+       mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
        path_put(&nd.path);
        return err;
 }
 
 static int create_path(const char *nodepath)
 {
-       struct nameidata nd;
-       int err = 0;
+       int err;
 
        read_lock(&dirlock);
-       err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
-                             nodepath, LOOKUP_PARENT, &nd);
-       if (err == 0) {
-               struct dentry *dentry;
-
-               /* create directory right away */
-               dentry = lookup_create(&nd, 1);
-               if (!IS_ERR(dentry)) {
-                       err = vfs_mkdir(nd.path.dentry->d_inode,
-                                       dentry, 0755);
-                       dput(dentry);
-               }
-               mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
-               path_put(&nd.path);
-       } else if (err == -ENOENT) {
+       err = dev_mkdir(nodepath, 0755);
+       if (err == -ENOENT) {
                char *path;
                char *s;
 
@@ -129,7 +118,6 @@ static int create_path(const char *nodepath)
                kfree(path);
        }
        read_unlock(&dirlock);
-
        return err;
 }
 
@@ -213,16 +201,21 @@ static int dev_rmdir(const char *name)
        mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
        dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
        if (!IS_ERR(dentry)) {
-               if (dentry->d_inode)
-                       err = vfs_rmdir(nd.path.dentry->d_inode, dentry);
-               else
+               if (dentry->d_inode) {
+                       if (dentry->d_inode->i_private == &dev_mnt)
+                               err = vfs_rmdir(nd.path.dentry->d_inode,
+                                               dentry);
+                       else
+                               err = -EPERM;
+               } else {
                        err = -ENOENT;
+               }
                dput(dentry);
        } else {
                err = PTR_ERR(dentry);
        }
-       mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
 
+       mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
        path_put(&nd.path);
        return err;
 }