Commit dae7b665 authored by Li Zefan's avatar Li Zefan Committed by Al Viro
Browse files

btrfs: use memdup_user() 



Remove open-coded memdup_user().

Note this changes some GFP_NOFS to GFP_KERNEL, since copy_from_user() may
cause pagefault, it's pointless to pass GFP_NOFS to kmalloc().

Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 3939fcde

fs/btrfs/ioctl.c

+12 −37
Original line number Diff line number Diff line
@@ -461,15 +461,9 @@ static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg) 
	if (!capable(CAP_SYS_ADMIN))

		return -EPERM;



	vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);



	if (!vol_args)

		return -ENOMEM;



	if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {

		ret = -EFAULT;

		goto out;

	}

	vol_args = memdup_user(arg, sizeof(*vol_args));

	if (IS_ERR(vol_args))

		return PTR_ERR(vol_args);



	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';

	namelen = strlen(vol_args->name);
@@ -545,7 +539,6 @@ static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg) 


out_unlock:

	mutex_unlock(&root->fs_info->volume_mutex);

out:

	kfree(vol_args);

	return ret;

}
@@ -565,15 +558,9 @@ static noinline int btrfs_ioctl_snap_create(struct file *file, 
	if (root->fs_info->sb->s_flags & MS_RDONLY)

		return -EROFS;



	vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);



	if (!vol_args)

		return -ENOMEM;



	if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {

		ret = -EFAULT;

		goto out;

	}

	vol_args = memdup_user(arg, sizeof(*vol_args));

	if (IS_ERR(vol_args))

		return PTR_ERR(vol_args);



	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';

	namelen = strlen(vol_args->name);
@@ -675,19 +662,13 @@ static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg) 
	if (!capable(CAP_SYS_ADMIN))

		return -EPERM;



	vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);

	vol_args = memdup_user(arg, sizeof(*vol_args));

	if (IS_ERR(vol_args))

		return PTR_ERR(vol_args);



	if (!vol_args)

		return -ENOMEM;



	if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {

		ret = -EFAULT;

		goto out;

	}

	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';

	ret = btrfs_init_new_device(root, vol_args->name);



out:

	kfree(vol_args);

	return ret;

}
@@ -703,19 +684,13 @@ static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg) 
	if (root->fs_info->sb->s_flags & MS_RDONLY)

		return -EROFS;



	vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);

	vol_args = memdup_user(arg, sizeof(*vol_args));

	if (IS_ERR(vol_args))

		return PTR_ERR(vol_args);



	if (!vol_args)

		return -ENOMEM;



	if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {

		ret = -EFAULT;

		goto out;

	}

	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';

	ret = btrfs_rm_device(root, vol_args->name);



out:

	kfree(vol_args);

	return ret;

}

fs/btrfs/super.c

+4 −9
Original line number Diff line number Diff line
@@ -635,14 +635,9 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd, 
	if (!capable(CAP_SYS_ADMIN))

		return -EPERM;



	vol = kmalloc(sizeof(*vol), GFP_KERNEL);

	if (!vol)

		return -ENOMEM;



	if (copy_from_user(vol, (void __user *)arg, sizeof(*vol))) {

		ret = -EFAULT;

		goto out;

	}

	vol = memdup_user((void __user *)arg, sizeof(*vol));

	if (IS_ERR(vol))

		return PTR_ERR(vol);



	switch (cmd) {

	case BTRFS_IOC_SCAN_DEV:
@@ -650,7 +645,7 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd, 
					    &btrfs_fs_type, &fs_devices);

		break;

	}

out:



	kfree(vol);

	return ret;

}