btrfs: initialize the seq counter in struct btrfs_device

Orabug: 23331031

[ Upstream commit 546bed631203344611f42b2af1d224d2eedb4e6b ]

I managed to trigger this:
| INFO: trying to register non-static key.
| the code is fine but needs lockdep annotation.
| turning off the locking correctness validator.
| CPU: 1 PID: 781 Comm: systemd-gpt-aut Not tainted 4.4.0-rt2+ #14
| Hardware name: ARM-Versatile Express
| [<80307cec>] (dump_stack)
| [<80070e98>] (__lock_acquire)
| [<8007184c>] (lock_acquire)
| [<80287800>] (btrfs_ioctl)
| [<8012a8d4>] (do_vfs_ioctl)
| [<8012ac14>] (SyS_ioctl)

so I think that btrfs_device_data_ordered_init() is not invoked behind
a macro somewhere.

Fixes: 7cc8e58d53cd ("Btrfs: fix unprotected device's variants on 32bits machine")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
(cherry picked from commit 2068256b08824ad53b28fb08952b62dd35e66593)

Signed-off-by: Dan Duval <dan.duval@oracle.com>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 5113b7257b453353a4433410e42d5d507e10e0bf..18a3573e14441eb8900111d6a6efbb82d329598f 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -152,6 +152,7 @@ static struct btrfs_device *__alloc_device(void)
        spin_lock_init(&dev->reada_lock);
        atomic_set(&dev->reada_in_flight, 0);
        atomic_set(&dev->dev_stats_ccnt, 0);
+       btrfs_device_data_ordered_init(dev);
        INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_WAIT);
        INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_WAIT);