Commit 67ae34b6 authored by David Sterba's avatar David Sterba
Browse files

btrfs: add device delete cancel 



Accept device name "cancel" as a request to cancel running device
deletion operation. The string is literal, in case there's a real device
named "cancel", pass it as full absolute path or as "./cancel"

This works for v1 and v2 ioctls when the device is specified by name.
Moving chunks from the device uses relocation, use the conditional
exclusive operation start and cancellation helpers

Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent bb059a37

fs/btrfs/ioctl.c

+24 −19
Original line number Original line Diff line number Diff line
@@ -3206,6 +3206,7 @@ static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg) 
	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);

	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);

	struct btrfs_ioctl_vol_args_v2 *vol_args;

	struct btrfs_ioctl_vol_args_v2 *vol_args;

	int ret;

	int ret;

	bool cancel = false;





	if (!capable(CAP_SYS_ADMIN))

	if (!capable(CAP_SYS_ADMIN))

		return -EPERM;

		return -EPERM;
@@ -3224,18 +3225,22 @@ static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg) 
		ret = -EOPNOTSUPP;

		ret = -EOPNOTSUPP;

		goto out;

		goto out;

	}

	}

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

	if (!(vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) &&

	    strcmp("cancel", vol_args->name) == 0)

		cancel = true;





	if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REMOVE)) {

	ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_DEV_REMOVE,

		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;

					   cancel);

	if (ret)

		goto out;

		goto out;

	}

	/* Exclusive operation is now claimed */





	if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {

	if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)

		ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);

		ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);

	} else {

	else

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

		ret = btrfs_rm_device(fs_info, vol_args->name, 0);

		ret = btrfs_rm_device(fs_info, vol_args->name, 0);

	}



	btrfs_exclop_finish(fs_info);

	btrfs_exclop_finish(fs_info);





	if (!ret) {

	if (!ret) {
@@ -3259,6 +3264,7 @@ static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg) 
	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);

	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);

	struct btrfs_ioctl_vol_args *vol_args;

	struct btrfs_ioctl_vol_args *vol_args;

	int ret;

	int ret;

	bool cancel;





	if (!capable(CAP_SYS_ADMIN))

	if (!capable(CAP_SYS_ADMIN))

		return -EPERM;

		return -EPERM;
@@ -3267,25 +3273,24 @@ static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg) 
	if (ret)

	if (ret)

		return ret;

		return ret;





	if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REMOVE)) {

		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;

		goto out_drop_write;

	}



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

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

	if (IS_ERR(vol_args)) {

	if (IS_ERR(vol_args)) {

		ret = PTR_ERR(vol_args);

		ret = PTR_ERR(vol_args);

		goto out;

		goto out_drop_write;

	}

	}



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

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

	ret = btrfs_rm_device(fs_info, vol_args->name, 0);

	cancel = (strcmp("cancel", vol_args->name) == 0);





	ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_DEV_REMOVE,

					   cancel);

	if (ret == 0) {

		ret = btrfs_rm_device(fs_info, vol_args->name, 0);

		if (!ret)

		if (!ret)

			btrfs_info(fs_info, "disk deleted %s", vol_args->name);

			btrfs_info(fs_info, "disk deleted %s", vol_args->name);

	kfree(vol_args);

out:

		btrfs_exclop_finish(fs_info);

		btrfs_exclop_finish(fs_info);

	}



	kfree(vol_args);

out_drop_write:

out_drop_write:

	mnt_drop_write_file(file);

	mnt_drop_write_file(file);