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>

1 files changed, 16 insertions, 23 deletions

diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 880a203b6688..c7f5c08f8790 100644
--- 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;
 }