@@ -2266,7 +2266,7 @@ int btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info, u64 devid,
static int btrfs_prepare_sprout(struct btrfs_fs_info *fs_info)
{
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
- struct btrfs_fs_devices *old_devices;
+ struct btrfs_fs_devices *old_fs_devices;
struct btrfs_fs_devices *seed_devices;
struct btrfs_super_block *disk_super = fs_info->super_copy;
struct btrfs_device *device;
@@ -2280,14 +2280,6 @@ static int btrfs_prepare_sprout(struct btrfs_fs_info *fs_info)
if (IS_ERR(seed_devices))
return PTR_ERR(seed_devices);
- old_devices = clone_fs_devices(fs_devices);
- if (IS_ERR(old_devices)) {
- kfree(seed_devices);
- return PTR_ERR(old_devices);
- }
-
- list_add(&old_devices->fs_list, &fs_uuids);
-
memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
seed_devices->opened = 1;
INIT_LIST_HEAD(&seed_devices->devices);
@@ -2320,6 +2312,17 @@ static int btrfs_prepare_sprout(struct btrfs_fs_info *fs_info)
~BTRFS_SUPER_FLAG_SEEDING;
btrfs_set_super_flags(disk_super, super_flags);
+ /*
+ * As the above code hijacked the original seed fs_devices, now
+ * create a new one for the original seed FSID.
+ */
+ list_for_each_entry(device, &fs_devices->seed->devices, dev_list) {
+ if (!device->name)
+ continue;
+ btrfs_scan_one_device(device->name->str, FMODE_READ,
+ fs_info->bdev_holder, &old_fs_devices);
+ }
+
return 0;
}
When we add a device to the RO mounted seed device, it becomes a RW sprout FS. The following steps are used to hold the seed and sprout fs_devices. (first two steps are not mandatory for the sprouting, they are there to ensure the seed device remains in the scanned state) . Clone the (mounted) fs_devices, lets call it as old_devices . Now add old_devices to fs_uuids (yeah, there is duplicate fsid in the list, as we are under uuid_mutex so its fine). . Alloc a new fs_devices, lets call it as seed_devices . Copy fs_devices into the seed_devices . Move fs_devices::devices into seed_devices::devices . Bring seed_devices to under fs_devices::seed (fs_devices->seed = seed_devices) . Assign a new FSID to the fs_devices and add the new writable device to the fs_devices. This patch makes the following changes.. As we clone fs_devices to make sure the device remains scanned after the sprouting. So use the btrfs_scan_one_device() code instead. And do it at the end of the sprouting. Signed-off-by: Anand Jain <anand.jain@oracle.com> --- As I don't this patch in the ML. I am sending this again, with no change. fs/btrfs/volumes.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-)