The user land progs needs a simple way to read the raw list of disks and its parameters as btrfs kernel understands it. This patch will introduce BTRFS_IOC_GET_DEVS which dumps every thing under fs_devices.
As of now btrfs-devlist uses this ioctl. In the long run this ioctl would help to optimize some part of btrfs-progs, mainly the current btrfs filesystem show Signed-off-by: Anand Jain <[email protected]> --- fs/btrfs/super.c | 56 +++++++++++++++++++++++++ fs/btrfs/volumes.c | 99 ++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/volumes.h | 2 + include/uapi/linux/btrfs.h | 45 ++++++++++++++++++++ 4 files changed, 202 insertions(+), 0 deletions(-) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 878874b..2fc0e2b 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1693,6 +1693,59 @@ static struct file_system_type btrfs_fs_type = { }; MODULE_ALIAS_FS("btrfs"); +static int btrfs_ioc_get_devlist(void __user *arg) +{ + int ret = 0; + u64 sz_devlist_arg; + u64 sz_devlist; + u64 sz_out; + + struct btrfs_ioctl_devlist_args *devlist_arg; + struct btrfs_ioctl_devlist_args *tmp_devlist_arg; + struct btrfs_ioctl_devlist *devlist; + + u64 cnt = 0, ucnt; + + sz_devlist_arg = sizeof(*devlist_arg); + sz_devlist = sizeof(*devlist); + + if (copy_from_user(&ucnt, + (struct btrfs_ioctl_devlist_args __user *)(arg + + offsetof(struct btrfs_ioctl_devlist_args, count)), + sizeof(ucnt))) + return -EFAULT; + + cnt = btrfs_get_devlist_cnt(); + + if (cnt > ucnt) { + if (copy_to_user(arg + + offsetof(struct btrfs_ioctl_devlist_args, count), + &cnt, sizeof(cnt))) + return -EFAULT; + return 1; + } + + sz_out = sz_devlist_arg + sz_devlist * cnt; + + tmp_devlist_arg = devlist_arg = memdup_user(arg, sz_out); + if (IS_ERR(devlist_arg)) + return PTR_ERR(devlist_arg); + + devlist = (struct btrfs_ioctl_devlist *) (++tmp_devlist_arg); + cnt = btrfs_get_devlist(devlist, cnt); + devlist_arg->count = cnt; + + if (copy_to_user(arg, devlist_arg, sz_out)) { + ret = -EFAULT; + goto out; + } + ret = 0; +out: + kfree(devlist_arg); + return ret; + +} + static int btrfs_ioc_get_fslist(void __user *arg) { int ret = 0; @@ -1777,6 +1830,9 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd, case BTRFS_IOC_GET_FSLIST: ret = btrfs_ioc_get_fslist(argp); break; + case BTRFS_IOC_GET_DEVS: + ret = btrfs_ioc_get_devlist(argp); + break; } return ret; diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 2ca91fc..f00ba27 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -6322,3 +6322,102 @@ u64 btrfs_get_fslist(struct btrfs_ioctl_fslist *fslist, u64 ucnt) return cnt; } + +int btrfs_get_devlist_cnt(void) +{ + int cnt = 0; + struct btrfs_device *device; + struct btrfs_fs_devices *fs_devices; + + mutex_lock(&uuid_mutex); + list_for_each_entry(fs_devices, &fs_uuids, list) + list_for_each_entry(device, &fs_devices->devices, dev_list) + cnt++; + mutex_unlock(&uuid_mutex); + + return cnt; +} + +u64 btrfs_get_devlist(struct btrfs_ioctl_devlist *dev, u64 alloc_cnt) +{ + u64 cnt = 0; + + struct btrfs_device *device; + struct btrfs_fs_devices *fs_devices; + + mutex_lock(&uuid_mutex); + /* Todo: there must be better way of doing this */ + list_for_each_entry(fs_devices, &fs_uuids, list) { + + mutex_lock(&fs_devices->device_list_mutex); + + list_for_each_entry(device, &fs_devices->devices, dev_list) { + + if (!(cnt < alloc_cnt)) + break; + + memcpy(dev->fsid, fs_devices->fsid, BTRFS_FSID_SIZE); + dev->fs_latest_devid = fs_devices->latest_devid; + dev->fs_latest_trans = fs_devices->latest_trans; + dev->fs_num_devices = fs_devices->num_devices; + dev->fs_open_devices = fs_devices->open_devices; + dev->fs_rw_devices = fs_devices->rw_devices; + dev->fs_missing_devices = fs_devices->missing_devices; + dev->fs_total_rw_bytes = fs_devices->total_rw_bytes; + dev->fs_num_can_discard = fs_devices->num_can_discard; + dev->fs_total_devices = fs_devices->total_devices; + + if (fs_devices->opened) + dev->flags = BTRFS_FS_MOUNTED; + if (fs_devices->seeding) + dev->flags |= BTRFS_FS_SEEDING; + if (fs_devices->rotating) + dev->flags |= BTRFS_FS_ROTATING; + + if (device->writeable) + dev->flags |= BTRFS_DEV_WRITEABLE; + if (device->in_fs_metadata) + dev->flags |= BTRFS_DEV_IN_FS_MD; + if (device->missing) + dev->flags |= BTRFS_DEV_MISSING; + if (device->can_discard) + dev->flags |= BTRFS_DEV_CAN_DISCARD; + if (device->is_tgtdev_for_dev_replace) + dev->flags |= BTRFS_DEV_SUBSTITUTED; + if (device->running_pending) + dev->flags |= BTRFS_DEV_RUN_PENDING; + if (device->nobarriers) + dev->flags |= BTRFS_DEV_NOBARRIERS; + if (device->dev_stats_valid) + dev->flags |= BTRFS_DEV_STATS_VALID; + if (device->dev_stats_dirty) + dev->flags |= BTRFS_DEV_STATS_DIRTY; + + dev->gen = device->generation; + dev->devid = device->devid; + dev->total_bytes = device->total_bytes; + dev->disk_total_bytes = device->disk_total_bytes; + dev->bytes_used = device->bytes_used; + dev->type = device->type; + dev->io_align = device->io_align; + dev->io_width = device->io_width; + dev->sector_size = device->sector_size; + memcpy(dev->uuid, device->uuid, BTRFS_UUID_SIZE); + if (device->name) { + rcu_read_lock(); + memcpy(dev->name, rcu_str_deref(device->name), + BTRFS_PATH_NAME_MAX); + rcu_read_unlock(); + } else { + memset(dev->name, 0, BTRFS_PATH_NAME_MAX); + } + dev++; + cnt++; + } + + mutex_unlock(&fs_devices->device_list_mutex); + } + mutex_unlock(&uuid_mutex); + + return cnt; +} diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index ebb0d0c..82a459c 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -392,4 +392,6 @@ static inline void btrfs_dev_stat_reset(struct btrfs_device *dev, } int btrfs_get_fslist_cnt(void); u64 btrfs_get_fslist(struct btrfs_ioctl_fslist *fslist, u64 ucnt); +int btrfs_get_devlist_cnt(void); +u64 btrfs_get_devlist(struct btrfs_ioctl_devlist *devlist, u64 ucnt); #endif diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h index 7d7f776..2983019 100644 --- a/include/uapi/linux/btrfs.h +++ b/include/uapi/linux/btrfs.h @@ -520,6 +520,8 @@ static inline char *btrfs_err_str(enum btrfs_err_code err_code) /* fs flags */ #define BTRFS_FS_MOUNTED (1LLU << 0) +#define BTRFS_FS_SEEDING (1LLU << 1) +#define BTRFS_FS_ROTATING (1LLU << 2) struct btrfs_ioctl_fslist { __u64 self_sz; /* in/out */ @@ -535,6 +537,47 @@ struct btrfs_ioctl_fslist_args { __u64 count; /* out */ }; +#define BTRFS_DEV_WRITEABLE (1LLU << 8) +#define BTRFS_DEV_IN_FS_MD (1LLU << 9) +#define BTRFS_DEV_MISSING (1LLU << 10) +#define BTRFS_DEV_CAN_DISCARD (1LLU << 11) +#define BTRFS_DEV_SUBSTITUTED (1LLU << 12) +#define BTRFS_DEV_RUN_PENDING (1LLU << 13) +#define BTRFS_DEV_NOBARRIERS (1LLU << 14) +#define BTRFS_DEV_STATS_VALID (1LLU << 15) +#define BTRFS_DEV_STATS_DIRTY (1LLU << 16) + +struct btrfs_ioctl_devlist { + __u64 sz_self; + __u64 fs_latest_devid; + __u64 fs_latest_trans; + __u64 fs_num_devices; + __u64 fs_open_devices; + __u64 fs_rw_devices; + __u64 fs_missing_devices; + __u64 fs_total_rw_bytes; + __u64 fs_num_can_discard; + __u64 fs_total_devices; + __u64 gen; + __u64 flags; + __u64 devid; + __u64 total_bytes; + __u64 disk_total_bytes; + __u64 bytes_used; + __u64 type; + __u32 io_align; + __u32 io_width; + __u32 sector_size; + __u8 fsid[BTRFS_FSID_SIZE]; + __u8 uuid[BTRFS_UUID_SIZE]; + __u8 name[BTRFS_PATH_NAME_MAX]; +}__attribute__ ((__packed__)); + +struct btrfs_ioctl_devlist_args { + __u64 self_sz; /* in/out */ + __u64 count; /* in/out */ +}; + #define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \ struct btrfs_ioctl_vol_args) #define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \ @@ -638,5 +681,7 @@ struct btrfs_ioctl_fslist_args { 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_GET_DEVS _IOWR(BTRFS_IOCTL_MAGIC, 58, \ + struct btrfs_ioctl_devlist_args) #endif /* _UAPI_LINUX_BTRFS_H */ -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
