Commit 6b526ed7 authored by Anand Jain's avatar Anand Jain Committed by David Sterba
Browse files

btrfs: introduce device delete by devid 



This introduces new ioctl BTRFS_IOC_RM_DEV_V2, which uses enhanced struct
btrfs_ioctl_vol_args_v2 to carry devid as an user argument.

The patch won't delete the old ioctl interface and so kernel remains
backward compatible with user land progs.

Test case/script:
echo "0 $(blockdev --getsz /dev/sdf) linear /dev/sdf 0" | dmsetup create bad_disk
mkfs.btrfs -f -d raid1 -m raid1 /dev/sdd /dev/sde /dev/mapper/bad_disk
mount /dev/sdd /btrfs
dmsetup suspend bad_disk
echo "0 $(blockdev --getsz /dev/sdf) error /dev/sdf 0" | dmsetup load bad_disk
dmsetup resume bad_disk
echo "bad disk failed. now deleting/replacing"
btrfs dev del  3  /btrfs
echo $?
btrfs fi show /btrfs
umount /btrfs
btrfs-show-super /dev/sdd | egrep num_device
dmsetup remove bad_disk
wipefs -a /dev/sdf

Signed-off-by: default avatarAnand Jain <anand.jain@oracle.com>
Reported-by: default avatarMartin <m_btrfs@ml1.co.uk>
[ adjust messages, s/disk/device/ ]
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 42b67427

fs/btrfs/ioctl.c

+57 −1
Original line number Diff line number Diff line
@@ -2667,6 +2667,60 @@ out: 
	return ret;

}



static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)

{

	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;

	struct btrfs_ioctl_vol_args_v2 *vol_args;

	int ret;



	if (!capable(CAP_SYS_ADMIN))

		return -EPERM;



	ret = mnt_want_write_file(file);

	if (ret)

		return ret;



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

	if (IS_ERR(vol_args)) {

		ret = PTR_ERR(vol_args);

		goto err_drop;

	}



	/* Check for compatibility reject unknown flags */

	if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS)

		return -ENOTTY;



	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,

			1)) {

		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;

		goto out;

	}



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

	if (vol_args->flags & BTRFS_DEVICE_BY_ID) {

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

	} else {

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

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

	}

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

	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);



	if (!ret) {

		if (vol_args->flags & BTRFS_DEVICE_BY_ID)

			btrfs_info(root->fs_info, "device deleted: id %llu",

					vol_args->devid);

		else

			btrfs_info(root->fs_info, "device deleted: %s",

					vol_args->name);

	}

out:

	kfree(vol_args);

err_drop:

	mnt_drop_write_file(file);

	return ret;

}



static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)

{

	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
@@ -2695,7 +2749,7 @@ static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg) 
	}



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

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

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

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

	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
@@ -5459,6 +5513,8 @@ long btrfs_ioctl(struct file *file, unsigned int 
		return btrfs_ioctl_add_dev(root, argp);

	case BTRFS_IOC_RM_DEV:

		return btrfs_ioctl_rm_dev(file, argp);

	case BTRFS_IOC_RM_DEV_V2:

		return btrfs_ioctl_rm_dev_v2(file, argp);

	case BTRFS_IOC_FS_INFO:

		return btrfs_ioctl_fs_info(root, argp);

	case BTRFS_IOC_DEV_INFO:

fs/btrfs/volumes.c

+2 −2
Original line number Diff line number Diff line
@@ -1748,7 +1748,7 @@ static int __check_raid_min_devices(struct btrfs_fs_info *fs_info) 
	return 0;

}



int btrfs_rm_device(struct btrfs_root *root, char *device_path)

int btrfs_rm_device(struct btrfs_root *root, char *device_path, u64 devid)

{

	struct btrfs_device *device;

	struct btrfs_device *next_device;
@@ -1764,7 +1764,7 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path) 
	if (ret)

		goto out;



	ret = btrfs_find_device_by_user_input(root, 0, device_path,

	ret = btrfs_find_device_by_user_input(root, devid, device_path,

				&device);

	if (ret)

		goto out;

fs/btrfs/volumes.h

+1 −1
Original line number Diff line number Diff line
@@ -454,7 +454,7 @@ int btrfs_find_device_by_user_input(struct btrfs_root *root, u64 srcdevid, 
struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,

					const u64 *devid,

					const u8 *uuid);

int btrfs_rm_device(struct btrfs_root *root, char *device_path);

int btrfs_rm_device(struct btrfs_root *root, char *device_path, u64 devid);

void btrfs_cleanup_fs_uuids(void);

int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);

int btrfs_grow_device(struct btrfs_trans_handle *trans,

include/uapi/linux/btrfs.h

+13 −1
Original line number Diff line number Diff line
@@ -36,6 +36,13 @@ struct btrfs_ioctl_vol_args { 
#define BTRFS_SUBVOL_CREATE_ASYNC	(1ULL << 0)

#define BTRFS_SUBVOL_RDONLY		(1ULL << 1)

#define BTRFS_SUBVOL_QGROUP_INHERIT	(1ULL << 2)

#define BTRFS_DEVICE_BY_ID		(1ULL << 3)

#define BTRFS_VOL_ARG_V2_FLAGS				\

			(BTRFS_SUBVOL_CREATE_ASYNC |	\

			BTRFS_SUBVOL_RDONLY |		\

			BTRFS_SUBVOL_QGROUP_INHERIT |	\

			BTRFS_DEVICE_BY_ID)



#define BTRFS_FSID_SIZE 16

#define BTRFS_UUID_SIZE 16

#define BTRFS_UUID_UNPARSED_SIZE	37
@@ -76,7 +83,10 @@ struct btrfs_ioctl_vol_args_v2 { 
		};

		__u64 unused[4];

	};

	union {

		char name[BTRFS_SUBVOL_NAME_MAX + 1];

		u64 devid;

	};

};



/*
@@ -659,5 +669,7 @@ static inline char *btrfs_err_str(enum btrfs_err_code err_code) 
				   struct btrfs_ioctl_feature_flags[2])

#define BTRFS_IOC_GET_SUPPORTED_FEATURES _IOR(BTRFS_IOCTL_MAGIC, 57, \

				   struct btrfs_ioctl_feature_flags[3])

#define BTRFS_IOC_RM_DEV_V2 _IOW(BTRFS_IOCTL_MAGIC, 58, \

				   struct btrfs_ioctl_vol_args_v2)



#endif /* _UAPI_LINUX_BTRFS_H */

CRA Git | Maintained and supported by SUSTech CRA and CCSE