From: Anand Jain
The user land progs needs a simple way to see
the raw list of disks and its parameters as seen
by the btrfs kernel.
As of now btrfs-devlist uses this ioctl.
Signed-off-by: Anand Jain
---
v2: add more parameter to get from the kernel
fs/btrfs/super.c | 56 ++
fs/btrfs/volumes.c | 140 +
fs/btrfs/volumes.h | 2 +
include/uapi/linux/btrfs.h | 49
4 files changed, 247 insertions(+)
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index afb719e..f3c0247 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1717,6 +1717,59 @@ 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;
@@ -1801,6 +1854,9 @@ 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 253fd9f..3c44800 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6338,3 +6338,143 @@ 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;
+ struct btrfs_fs_devices *cur_fs_devices;
+
+ mutex_lock(&uuid_mutex);
+ list_for_each_entry(cur_fs_devices, &fs_uuids, list) {
+
+ fs_devices = cur_fs_devices;
+again_dev_cnt:
+ list_for_each_entry(device, &fs_devices->devices, dev_list)
+ cnt++;
+
+ fs_devices = fs_devices->seed;
+ if (fs_devices)
+ goto again_dev_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;
+ struct btrfs_fs_devices *cur_fs_devices;
+ struct btrfs_fs_devices *sprout_fs_devices;
+
+ mutex_lock(&uuid_mutex);
+ /* Todo: there must be better way of doing this */
+ list_for_each_entry(cur_fs_devices, &fs_uuids, list) {
+
+ mutex_lock(&cur_fs_devices->device_list_mutex);
+
+ fs_devices = cur_fs_devices;
+ sprout_fs_devices = NULL;
+
+again_dev:
+ list_for_each_entry(device, &fs_devices->devices, dev_list) {
+
+ if (!(cnt < alloc_cnt))
+ break;
+
+ memcpy(dev->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
+
+ if (fs_devices->seed)
+ memcpy(dev->seed_fsid, fs_devices->seed->fsid,
+ BTRFS_FSID_SIZE);
+ else
+ memset(dev->seed_fsid, 0, BTRFS_FSID_SIZE);
+
+ if (sprout_fs_devices)
+ memcpy(dev->sprout_fsid,
sprout_fs_devices->fsid,
+ BTRFS_FSID_SIZE);
+ else
+ memset(dev->sp
