btrfs: call mnt_drop_write after interrupted subvol deletion

If btrfs_ioctl_snap_destroy blocks on the mutex and the process is
killed, mnt_write count is unbalanced and leads to unmountable
filesystem.

CC: stable@vger.kernel.org
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
This commit is contained in:
David Sterba 2013-12-06 17:51:32 +01:00 коммит произвёл Chris Mason
Родитель a7e252af5a
Коммит e43f998e47
1 изменённых файлов: 2 добавлений и 1 удалений

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@ -2121,7 +2121,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
err = mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT);
if (err == -EINTR)
goto out;
goto out_drop_write;
dentry = lookup_one_len(vol_args->name, parent, namelen);
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
@ -2284,6 +2284,7 @@ out_dput:
dput(dentry);
out_unlock_dir:
mutex_unlock(&dir->i_mutex);
out_drop_write:
mnt_drop_write_file(file);
out:
kfree(vol_args);