From 6b526ed70cf189660d009ea6f17af77a9cca0f38 Mon Sep 17 00:00:00 2001 From: Anand Jain Date: Sat, 13 Feb 2016 10:01:39 +0800 Subject: [PATCH] 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: Anand Jain Reported-by: Martin [ adjust messages, s/disk/device/ ] Signed-off-by: David Sterba --- fs/btrfs/ioctl.c | 58 +++++++++++++++++++++++++++++++++++++- fs/btrfs/volumes.c | 4 +-- fs/btrfs/volumes.h | 2 +- include/uapi/linux/btrfs.h | 14 ++++++++- 4 files changed, 73 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 5a23806ae418..7cf0f6328d99 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -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: diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 8264b06756e6..1421d711629f 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -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; diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 508739314e43..c73d027e2f8b 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -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, diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h index dea893199257..396a4efca775 100644 --- a/include/uapi/linux/btrfs.h +++ b/include/uapi/linux/btrfs.h @@ -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]; }; - char name[BTRFS_SUBVOL_NAME_MAX + 1]; + 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 */ -- 2.20.1