[Xen-changelog] Move non-transactional and non-idempotent code out of

[Xen patchbot -unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User kaf24@xxxxxxxxxxxxxxxxxxxx
# Node ID 70b6e60df7502463a240689ed0f6b4975b9a9a62
# Parent  8c2aa08789277490d6ff5ee3523a080d514c5570
Move non-transactional and non-idempotent code out of
xenstore transaction retry loops in our device drivers.
Otherwise things get very smelly if a transaction fails and
is retried.

Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>

diff -r 8c2aa0878927 -r 70b6e60df750 
linux-2.6-xen-sparse/drivers/xen/blkback/xenbus.c
--- a/linux-2.6-xen-sparse/drivers/xen/blkback/xenbus.c Mon Sep 26 17:49:21 2005
+++ b/linux-2.6-xen-sparse/drivers/xen/blkback/xenbus.c Mon Sep 26 18:13:57 2005
@@ -80,6 +80,15 @@
                return;
        }
 
+       /* Map the shared frame, irq etc. */
+       err = blkif_map(be->blkif, ring_ref, evtchn);
+       if (err) {
+               xenbus_dev_error(be->dev, err, "mapping ring-ref %lu port %u",
+                                ring_ref, evtchn);
+               return;
+       }
+       /* XXX From here on should 'blkif_unmap' on error. */
+
 again:
        /* Supply the information about the device the frontend needs */
        err = xenbus_transaction_start();
@@ -109,14 +118,6 @@
        if (err) {
                xenbus_dev_error(be->dev, err, "writing %s/sector-size",
                                 be->dev->nodename);
-               goto abort;
-       }
-
-       /* Map the shared frame, irq etc. */
-       err = blkif_map(be->blkif, ring_ref, evtchn);
-       if (err) {
-               xenbus_dev_error(be->dev, err, "mapping ring-ref %lu port %u",
-                                ring_ref, evtchn);
                goto abort;
        }
 
diff -r 8c2aa0878927 -r 70b6e60df750 
linux-2.6-xen-sparse/drivers/xen/blkfront/blkfront.c
--- a/linux-2.6-xen-sparse/drivers/xen/blkfront/blkfront.c      Mon Sep 26 
17:49:21 2005
+++ b/linux-2.6-xen-sparse/drivers/xen/blkfront/blkfront.c      Mon Sep 26 
18:13:57 2005
@@ -591,17 +591,6 @@
                goto abort_transaction;
        }
 
-       info->backend = backend;
-       backend = NULL;
-
-       info->watch.node = info->backend;
-       info->watch.callback = watch_for_status;
-       err = register_xenbus_watch(&info->watch);
-       if (err) {
-               message = "registering watch on backend";
-               goto abort_transaction;
-       }
-
        err = xenbus_transaction_end(0);
        if (err) {
                if (err == -EAGAIN)
@@ -610,10 +599,17 @@
                goto destroy_blkring;
        }
 
- out:
-       if (backend)
-               kfree(backend);
-       return err;
+       info->watch.node = backend;
+       info->watch.callback = watch_for_status;
+       err = register_xenbus_watch(&info->watch);
+       if (err) {
+               message = "registering watch on backend";
+               goto destroy_blkring;
+       }
+
+       info->backend = backend;
+
+       return 0;
 
  abort_transaction:
        xenbus_transaction_end(1);
@@ -621,7 +617,10 @@
        xenbus_dev_error(dev, err, "%s", message);
  destroy_blkring:
        blkif_free(info);
-       goto out;
+ out:
+       if (backend)
+               kfree(backend);
+       return err;
 }
 
 /* Setup supplies the backend dir, virtual device.
diff -r 8c2aa0878927 -r 70b6e60df750 
linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
--- a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c      Mon Sep 26 
17:49:21 2005
+++ b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c      Mon Sep 26 
18:13:57 2005
@@ -1148,17 +1148,6 @@
                goto abort_transaction;
        }
 
-       info->backend = backend;
-       backend = NULL;
-
-       info->watch.node = info->backend;
-       info->watch.callback = watch_for_status;
-       err = register_xenbus_watch(&info->watch);
-       if (err) {
-               message = "registering watch on backend";
-               goto abort_transaction;
-       }
-
        err = xenbus_transaction_end(0);
        if (err) {
                if (err == -EAGAIN)
@@ -1167,12 +1156,19 @@
                goto destroy_ring;
        }
 
+       info->watch.node = backend;
+       info->watch.callback = watch_for_status;
+       err = register_xenbus_watch(&info->watch);
+       if (err) {
+               message = "registering watch on backend";
+               goto destroy_ring;
+       }
+
+       info->backend = backend;
+
        netif_state = NETIF_STATE_CONNECTED;
 
- out:
-       if (backend)
-               kfree(backend);
-       return err;
+       return 0;
 
  abort_transaction:
        xenbus_transaction_end(1);
@@ -1180,7 +1176,10 @@
        xenbus_dev_error(dev, err, "%s", message);
  destroy_ring:
        shutdown_device(info);
-       goto out;
+ out:
+       if (backend)
+               kfree(backend);
+       return err;
 }
 
 /* Setup supplies the backend dir, virtual device.
diff -r 8c2aa0878927 -r 70b6e60df750 
linux-2.6-xen-sparse/drivers/xen/tpmback/xenbus.c
--- a/linux-2.6-xen-sparse/drivers/xen/tpmback/xenbus.c Mon Sep 26 17:49:21 2005
+++ b/linux-2.6-xen-sparse/drivers/xen/tpmback/xenbus.c Mon Sep 26 18:13:57 2005
@@ -88,6 +88,26 @@
                return;
        }
 
+       err = tpmif_map(be->tpmif, ringref, evtchn);
+       if (err) {
+               xenbus_dev_error(be->dev, err,
+                                "mapping shared-frame %lu port %u",
+                                ringref, evtchn);
+               return;
+       }
+
+       err = tpmif_vtpm_open(be->tpmif,
+                             be->frontend_id,
+                             be->instance);
+       if (err) {
+               xenbus_dev_error(be->dev, err,
+                                "queueing vtpm open packet");
+               /*
+                * Should close down this device and notify FE
+                * about closure.
+                */
+               return;
+       }
 
        /*
         * Tell the front-end that we are ready to go -
@@ -104,27 +124,6 @@
                            "ready", "%lu", ready);
        if (err) {
                xenbus_dev_error(be->dev, err, "writing 'ready'");
-               goto abort;
-       }
-
-       err = tpmif_map(be->tpmif, ringref, evtchn);
-       if (err) {
-               xenbus_dev_error(be->dev, err,
-                                "mapping shared-frame %lu port %u",
-                                ringref, evtchn);
-               goto abort;
-       }
-
-       err = tpmif_vtpm_open(be->tpmif,
-                             be->frontend_id,
-                             be->instance);
-       if (err) {
-               xenbus_dev_error(be->dev, err,
-                                "queueing vtpm open packet");
-               /*
-                * Should close down this device and notify FE
-                * about closure.
-                */
                goto abort;
        }
 
diff -r 8c2aa0878927 -r 70b6e60df750 
linux-2.6-xen-sparse/drivers/xen/tpmfront/tpmfront.c
--- a/linux-2.6-xen-sparse/drivers/xen/tpmfront/tpmfront.c      Mon Sep 26 
17:49:21 2005
+++ b/linux-2.6-xen-sparse/drivers/xen/tpmfront/tpmfront.c      Mon Sep 26 
18:13:57 2005
@@ -352,17 +352,6 @@
                goto abort_transaction;
        }
 
-       info->backend = backend;
-       backend = NULL;
-
-       info->watch.node = info->backend;
-       info->watch.callback = watch_for_status;
-       err = register_xenbus_watch(&info->watch);
-       if (err) {
-               message = "registering watch on backend";
-               goto abort_transaction;
-       }
-
        err = xenbus_transaction_end(0);
        if (err == -EAGAIN)
                goto again;
@@ -371,10 +360,17 @@
                goto destroy_tpmring;
        }
 
-out:
-       if (backend)
-               kfree(backend);
-       return err;
+       info->watch.node = backend;
+       info->watch.callback = watch_for_status;
+       err = register_xenbus_watch(&info->watch);
+       if (err) {
+               message = "registering watch on backend";
+               goto destroy_tpmring;
+       }
+
+       info->backend = backend;
+
+       return 0;
 
 abort_transaction:
        xenbus_transaction_end(1);
@@ -382,7 +378,10 @@
        xenbus_dev_error(dev, err, "%s", message);
 destroy_tpmring:
        destroy_tpmring(info, &my_private);
-       goto out;
+out:
+       if (backend)
+               kfree(backend);
+       return err;
 }
 
 

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