Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-3.10.git] / security / inode.c
index 8883986..43ce6e1 100644 (file)
 static struct vfsmount *mount;
 static int mount_count;
 
-/*
- * TODO:
- *   I think I can get rid of these default_file_ops, but not quite sure...
- */
-static ssize_t default_read_file(struct file *file, char __user *buf,
-                                size_t count, loff_t *ppos)
-{
-       return 0;
-}
-
-static ssize_t default_write_file(struct file *file, const char __user *buf,
-                                  size_t count, loff_t *ppos)
-{
-       return count;
-}
-
-static int default_open(struct inode *inode, struct file *file)
-{
-       if (inode->i_private)
-               file->private_data = inode->i_private;
-
-       return 0;
-}
-
-static const struct file_operations default_file_ops = {
-       .read =         default_read_file,
-       .write =        default_write_file,
-       .open =         default_open,
-       .llseek =       noop_llseek,
-};
-
-static struct inode *get_inode(struct super_block *sb, int mode, dev_t dev)
-{
-       struct inode *inode = new_inode(sb);
-
-       if (inode) {
-               inode->i_mode = mode;
-               inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
-               switch (mode & S_IFMT) {
-               default:
-                       init_special_inode(inode, mode, dev);
-                       break;
-               case S_IFREG:
-                       inode->i_fop = &default_file_ops;
-                       break;
-               case S_IFDIR:
-                       inode->i_op = &simple_dir_inode_operations;
-                       inode->i_fop = &simple_dir_operations;
-
-                       /* directory inodes start off with i_nlink == 2 (for "." entry) */
-                       inc_nlink(inode);
-                       break;
-               }
-       }
-       return inode;
-}
-
-/* SMP-safe */
-static int mknod(struct inode *dir, struct dentry *dentry,
-                        int mode, dev_t dev)
-{
-       struct inode *inode;
-       int error = -ENOMEM;
-
-       if (dentry->d_inode)
-               return -EEXIST;
-
-       inode = get_inode(dir->i_sb, mode, dev);
-       if (inode) {
-               d_instantiate(dentry, inode);
-               dget(dentry);
-               error = 0;
-       }
-       return error;
-}
-
-static int mkdir(struct inode *dir, struct dentry *dentry, int mode)
-{
-       int res;
-
-       mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
-       res = mknod(dir, dentry, mode, 0);
-       if (!res)
-               inc_nlink(dir);
-       return res;
-}
-
-static int create(struct inode *dir, struct dentry *dentry, int mode)
-{
-       mode = (mode & S_IALLUGO) | S_IFREG;
-       return mknod(dir, dentry, mode, 0);
-}
-
 static inline int positive(struct dentry *dentry)
 {
        return dentry->d_inode && !d_unhashed(dentry);
@@ -130,52 +37,20 @@ static int fill_super(struct super_block *sb, void *data, int silent)
        return simple_fill_super(sb, SECURITYFS_MAGIC, files);
 }
 
-static int get_sb(struct file_system_type *fs_type,
+static struct dentry *get_sb(struct file_system_type *fs_type,
                  int flags, const char *dev_name,
-                 void *data, struct vfsmount *mnt)
+                 void *data)
 {
-       return get_sb_single(fs_type, flags, data, fill_super, mnt);
+       return mount_single(fs_type, flags, data, fill_super);
 }
 
 static struct file_system_type fs_type = {
        .owner =        THIS_MODULE,
        .name =         "securityfs",
-       .get_sb =       get_sb,
+       .mount =        get_sb,
        .kill_sb =      kill_litter_super,
 };
 
-static int create_by_name(const char *name, mode_t mode,
-                         struct dentry *parent,
-                         struct dentry **dentry)
-{
-       int error = 0;
-
-       *dentry = NULL;
-
-       /* If the parent is not specified, we create it in the root.
-        * We need the root dentry to do this, which is in the super
-        * block. A pointer to that is in the struct vfsmount that we
-        * have around.
-        */
-       if (!parent)
-               parent = mount->mnt_sb->s_root;
-
-       mutex_lock(&parent->d_inode->i_mutex);
-       *dentry = lookup_one_len(name, parent, strlen(name));
-       if (!IS_ERR(*dentry)) {
-               if ((mode & S_IFMT) == S_IFDIR)
-                       error = mkdir(parent->d_inode, *dentry, mode);
-               else
-                       error = create(parent->d_inode, *dentry, mode);
-               if (error)
-                       dput(*dentry);
-       } else
-               error = PTR_ERR(*dentry);
-       mutex_unlock(&parent->d_inode->i_mutex);
-
-       return error;
-}
-
 /**
  * securityfs_create_file - create a file in the securityfs filesystem
  *
@@ -204,35 +79,70 @@ static int create_by_name(const char *name, mode_t mode,
  * If securityfs is not enabled in the kernel, the value %-ENODEV is
  * returned.
  */
-struct dentry *securityfs_create_file(const char *name, mode_t mode,
+struct dentry *securityfs_create_file(const char *name, umode_t mode,
                                   struct dentry *parent, void *data,
                                   const struct file_operations *fops)
 {
-       struct dentry *dentry = NULL;
+       struct dentry *dentry;
+       int is_dir = S_ISDIR(mode);
+       struct inode *dir, *inode;
        int error;
 
+       if (!is_dir) {
+               BUG_ON(!fops);
+               mode = (mode & S_IALLUGO) | S_IFREG;
+       }
+
        pr_debug("securityfs: creating file '%s'\n",name);
 
        error = simple_pin_fs(&fs_type, &mount, &mount_count);
-       if (error) {
-               dentry = ERR_PTR(error);
-               goto exit;
+       if (error)
+               return ERR_PTR(error);
+
+       if (!parent)
+               parent = mount->mnt_root;
+
+       dir = parent->d_inode;
+
+       mutex_lock(&dir->i_mutex);
+       dentry = lookup_one_len(name, parent, strlen(name));
+       if (IS_ERR(dentry))
+               goto out;
+
+       if (dentry->d_inode) {
+               error = -EEXIST;
+               goto out1;
        }
 
-       error = create_by_name(name, mode, parent, &dentry);
-       if (error) {
-               dentry = ERR_PTR(error);
-               simple_release_fs(&mount, &mount_count);
-               goto exit;
+       inode = new_inode(dir->i_sb);
+       if (!inode) {
+               error = -ENOMEM;
+               goto out1;
        }
 
-       if (dentry->d_inode) {
-               if (fops)
-                       dentry->d_inode->i_fop = fops;
-               if (data)
-                       dentry->d_inode->i_private = data;
+       inode->i_ino = get_next_ino();
+       inode->i_mode = mode;
+       inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+       inode->i_private = data;
+       if (is_dir) {
+               inode->i_op = &simple_dir_inode_operations;
+               inode->i_fop = &simple_dir_operations;
+               inc_nlink(inode);
+               inc_nlink(dir);
+       } else {
+               inode->i_fop = fops;
        }
-exit:
+       d_instantiate(dentry, inode);
+       dget(dentry);
+       mutex_unlock(&dir->i_mutex);
+       return dentry;
+
+out1:
+       dput(dentry);
+       dentry = ERR_PTR(error);
+out:
+       mutex_unlock(&dir->i_mutex);
+       simple_release_fs(&mount, &mount_count);
        return dentry;
 }
 EXPORT_SYMBOL_GPL(securityfs_create_file);