Btrfs: do not add replace target to the alloc_list

If replace was suspended by the umount, replace target device is added
to the fs_devices->alloc_list during a later mount.  This is obviously
wrong.  ->is_tgtdev_for_dev_replace is supposed to guard against that,
but ->is_tgtdev_for_dev_replace is (and can only ever be) initialized
*after* everything is opened and fs_devices lists are populated.  Fix
this by checking the devid instead: for replace targets it's always
equal to BTRFS_DEV_REPLACE_DEVID.

Cc: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 0db165ee4340..a0577352eb6e 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -796,7 +796,8 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
                         fs_devices->rotating = 1;
 
                 fs_devices->open_devices++;
-                if (device->writeable && !device->is_tgtdev_for_dev_replace) {
+                if (device->writeable &&
+                    device->devid != BTRFS_DEV_REPLACE_DEVID) {
                         fs_devices->rw_devices++;
                         list_add(&device->dev_alloc_list,
                                  &fs_devices->alloc_list);