From: Goffredo Baroncelli <[email protected]> This ioctl is a base for returning / setting information from / to the fields of the btrfs_dev_item object.
For now only the "type" field is returned / set. Signed-off-by: Goffredo Baroncelli <[email protected]> --- fs/btrfs/ioctl.c | 67 ++++++++++++++++++++++++++++++++++++++ fs/btrfs/volumes.c | 2 +- fs/btrfs/volumes.h | 2 ++ include/uapi/linux/btrfs.h | 40 +++++++++++++++++++++++ 4 files changed, 110 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 703212ff50a5..9e67741fa966 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -4842,6 +4842,71 @@ static int btrfs_ioctl_set_features(struct file *file, void __user *arg) return ret; } +static long btrfs_ioctl_dev_properties(struct file *file, + void __user *argp) +{ + struct inode *inode = file_inode(file); + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct btrfs_ioctl_dev_properties dev_props; + struct btrfs_device *device; + struct btrfs_root *root = fs_info->chunk_root; + struct btrfs_trans_handle *trans; + int ret; + u64 prev_type; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (copy_from_user(&dev_props, argp, sizeof(dev_props))) + return -EFAULT; + + device = btrfs_find_device(fs_info->fs_devices, dev_props.devid, + NULL, NULL); + if (!device) { + btrfs_info(fs_info, "change_dev_properties: unable to find device %llu", + dev_props.devid); + return -ENODEV; + } + + if (dev_props.properties & BTRFS_DEV_PROPERTY_READ) { + u64 props = dev_props.properties; + memset(&dev_props, 0, sizeof(dev_props)); + if (props & BTRFS_DEV_PROPERTY_TYPE) { + dev_props.properties = BTRFS_DEV_PROPERTY_TYPE; + dev_props.type = device->type; + } + if(copy_to_user(argp, &dev_props, sizeof(dev_props))) + return -EFAULT; + return 0; + } + + /* it is possible to set only BTRFS_DEV_PROPERTY_TYPE for now */ + if (dev_props.properties & ~(BTRFS_DEV_PROPERTY_TYPE)) + return -EPERM; + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + prev_type = device->type; + device->type = dev_props.type; + ret = btrfs_update_device(trans, device); + + if (ret < 0) { + btrfs_abort_transaction(trans, ret); + btrfs_end_transaction(trans); + device->type = prev_type; + return ret; + } + + ret = btrfs_commit_transaction(trans); + if (ret < 0) + device->type = prev_type; + + return ret; + +} + static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat) { struct btrfs_ioctl_send_args *arg; @@ -5025,6 +5090,8 @@ long btrfs_ioctl(struct file *file, unsigned int return btrfs_ioctl_get_subvol_rootref(file, argp); case BTRFS_IOC_INO_LOOKUP_USER: return btrfs_ioctl_ino_lookup_user(file, argp); + case BTRFS_IOC_DEV_PROPERTIES: + return btrfs_ioctl_dev_properties(file, argp); } return -ENOTTY; diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index ee086fc56c30..68b346c5465d 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -2744,7 +2744,7 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path return ret; } -static noinline int btrfs_update_device(struct btrfs_trans_handle *trans, +int btrfs_update_device(struct btrfs_trans_handle *trans, struct btrfs_device *device) { int ret; diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 1997a4649a66..d776b7f55d56 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -595,5 +595,7 @@ void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info, int btrfs_bg_type_to_factor(u64 flags); const char *btrfs_bg_type_to_raid_name(u64 flags); int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info); +int btrfs_update_device(struct btrfs_trans_handle *trans, + struct btrfs_device *device); #endif diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h index 5df73001aad4..e6caef42837a 100644 --- a/include/uapi/linux/btrfs.h +++ b/include/uapi/linux/btrfs.h @@ -860,6 +860,44 @@ struct btrfs_ioctl_get_subvol_rootref_args { __u8 align[7]; }; +#define BTRFS_DEV_PROPERTY_TYPE (1ULL << 0) +#define BTRFS_DEV_PROPERTY_DEV_GROUP (1ULL << 1) +#define BTRFS_DEV_PROPERTY_SEEK_SPEED (1ULL << 2) +#define BTRFS_DEV_PROPERTY_BANDWIDTH (1ULL << 3) +#define BTRFS_DEV_PROPERTY_READ (1ULL << 60) + +/* + * The ioctl BTRFS_IOC_DEV_PROPERTIES can read and write the device properties. + * + * The properties that the user want to write have to be set + * in the 'properties' field using the BTRFS_DEV_PROPERTY_xxxx constants. + * + * If the ioctl is used to read the device properties, the bit + * BTRFS_DEV_PROPERTY_READ has to be set in the 'properties' field. + * In this case the properties that the user want have to be set in the + * 'properties' field. The kernel doesn't return a property that was not + * required, however it may return a subset of the requested properties. + * The returned properties have the corrispondent BTRFS_DEV_PROPERTY_xxxx + * flag set in the 'properties' field. + * + * Up to 2020年05月11日 the only properties that can be read/write is the 'type' + * one. + */ +struct btrfs_ioctl_dev_properties { + __u64 devid; + __u64 properties; + __u64 type; + __u32 dev_group; + __u8 seek_speed; + __u8 bandwidth; + + /* + * for future expansion + */ + __u8 unused1[2]; + __u64 unused2[4]; +}; + /* Error codes as returned by the kernel */ enum btrfs_err_code { BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET = 1, @@ -988,5 +1026,7 @@ enum btrfs_err_code { struct btrfs_ioctl_ino_lookup_user_args) #define BTRFS_IOC_SNAP_DESTROY_V2 _IOW(BTRFS_IOCTL_MAGIC, 63, \ struct btrfs_ioctl_vol_args_v2) +#define BTRFS_IOC_DEV_PROPERTIES _IOW(BTRFS_IOCTL_MAGIC, 64, \ + struct btrfs_ioctl_dev_properties) #endif /* _UAPI_LINUX_BTRFS_H */ -- 2.30.0