btrfs: fix in-memory value of total_devices after seed device deletion

[ Upstream commit b4993e64f78a9605b45252fa9ba385c88a1f4ce9 ]

In case of deleting the seed device the %cur_devices (seed) and the
%fs_devices (parent) are different. Now, as the parent
fs_devices::total_devices also maintains the total number of devices
including the seed device, so decrement its in-memory value for the
successful seed delete. We are already updating its corresponding
on-disk btrfs_super_block::number_devices value.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 93765f17a45413f75a4ecd5b31ec918038e512b8..fca57c1f077cc70b6dbefdbf47affa15dc153553 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2029,6 +2029,9 @@ int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path,
 
        cur_devices->num_devices--;
        cur_devices->total_devices--;
+       /* Update total_devices of the parent fs_devices if it's seed */
+       if (cur_devices != fs_devices)
+               fs_devices->total_devices--;
 
        if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
                cur_devices->missing_devices--;