Btrfs: Fix wrong device size when we are resizing the device

total_bytes of device is just a in-memory variant which is used to record
the size of the device, and it might be changed before we resize a device,
if the resize operation fails, it will be fallbacked. But some code used it
to update on-disk metadata of the device, it would cause the problem that
on-disk metadata of the devices was not consistent. We should use the other
variant named disk_total_bytes to update the on-disk metadata of device,
because that variant is updated only when the resize operation is successful.
Fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

2 files changed, 3 insertions, 2 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index d0ed9e664f7d..c99a414813c1 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3450,7 +3450,8 @@ static int write_all_supers(struct btrfs_root *root, int max_mirrors)
                 btrfs_set_stack_device_generation(dev_item, 0);
                 btrfs_set_stack_device_type(dev_item, dev->type);
                 btrfs_set_stack_device_id(dev_item, dev->devid);
-                btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
+                btrfs_set_stack_device_total_bytes(dev_item,
+                                                   dev->disk_total_bytes);
                 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 00c8efdcd1e5..9d4ce53d7569 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1483,7 +1483,7 @@ static int btrfs_add_device(struct btrfs_trans_handle *trans,
         btrfs_set_device_io_align(leaf, dev_item, device->io_align);
         btrfs_set_device_io_width(leaf, dev_item, device->io_width);
         btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
-        btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
+        btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
         btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
         btrfs_set_device_group(leaf, dev_item, 0);
         btrfs_set_device_seek_speed(leaf, dev_item, 0);