drbd: protect updates to integrits_tfm by tconn->data->mutex

Since we need to hold that mutex anyways to make sure the peer
gets that change in the right position in the data stream,
it makes a lot of sense to use the same mutex to ensure existence
of the tfm.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 26d7763d5255..bca599a3c1e1 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -1720,11 +1720,11 @@ int drbd_send_dblock(struct drbd_conf *mdev, struct drbd_request *req)
         int dgs;
         int err;
 
+        sock = &mdev->tconn->data;
+        p = drbd_prepare_command(mdev, sock);
         dgs = (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->integrity_tfm) ?
                 crypto_hash_digestsize(mdev->tconn->integrity_tfm) : 0;
 
-        sock = &mdev->tconn->data;
-        p = drbd_prepare_command(mdev, sock);
         if (!p)
                 return -EIO;
         p->sector = cpu_to_be64(req->i.sector);
@@ -1793,11 +1793,12 @@ int drbd_send_block(struct drbd_conf *mdev, enum drbd_packet cmd,
         int err;
         int dgs;
 
+        sock = &mdev->tconn->data;
+        p = drbd_prepare_command(mdev, sock);
+
         dgs = (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->integrity_tfm) ?
                 crypto_hash_digestsize(mdev->tconn->integrity_tfm) : 0;
 
-        sock = &mdev->tconn->data;
-        p = drbd_prepare_command(mdev, sock);
         if (!p)
                 return -EIO;
         p->sector = cpu_to_be64(peer_req->i.sector);