# HG changeset patch
# User cl349@xxxxxxxxxxxxxxxxxxxx
# Node ID 6b94eaa59279b2a3a5917779f42b58abcd3478c3
# Parent 237dc67887cc6716359545a46edbbe1c17353722
Avoid calling device_unregister from device_register callback.
Also simplify code.
Signed-off-by: Christian Limpach <Christian.Limpach@xxxxxxxxxxxx>
diff -r 237dc67887cc -r 6b94eaa59279
linux-2.6-xen-sparse/drivers/xen/blkback/xenbus.c
--- a/linux-2.6-xen-sparse/drivers/xen/blkback/xenbus.c Wed Aug 24 20:10:12 2005
+++ b/linux-2.6-xen-sparse/drivers/xen/blkback/xenbus.c Wed Aug 24 20:11:07 2005
@@ -64,7 +64,7 @@
= container_of(watch, struct backend_info, watch);
/* If other end is gone, delete ourself. */
- if (!xenbus_exists(be->frontpath, "")) {
+ if (node && !xenbus_exists(be->frontpath, "")) {
xenbus_rm(be->dev->nodename, "");
device_unregister(&be->dev->dev);
return;
@@ -139,133 +139,123 @@
{
int err;
char *p;
- char *frontend;
long int handle, pdev;
struct backend_info *be
= container_of(watch, struct backend_info, backend_watch);
struct xenbus_device *dev = be->dev;
+
+ err = xenbus_scanf(dev->nodename, "physical-device", "%li", &pdev);
+ if (XENBUS_EXIST_ERR(err))
+ return;
+ if (err < 0) {
+ xenbus_dev_error(dev, err, "reading physical-device");
+ return;
+ }
+ if (be->pdev && be->pdev != pdev) {
+ printk(KERN_WARNING
+ "changing physical-device not supported\n");
+ return;
+ }
+ be->pdev = pdev;
+
+ /* If there's a read-only node, we're read only. */
+ p = xenbus_read(dev->nodename, "read-only", NULL);
+ if (!IS_ERR(p)) {
+ be->readonly = 1;
+ kfree(p);
+ }
+
+ if (be->blkif == NULL) {
+ /* Front end dir is a number, which is used as the handle. */
+ p = strrchr(be->frontpath, '/') + 1;
+ handle = simple_strtoul(p, NULL, 0);
+
+ be->blkif = alloc_blkif(be->frontend_id);
+ if (IS_ERR(be->blkif)) {
+ err = PTR_ERR(be->blkif);
+ be->blkif = NULL;
+ xenbus_dev_error(dev, err, "creating block interface");
+ return;
+ }
+
+ err = vbd_create(be->blkif, handle, be->pdev, be->readonly);
+ if (err) {
+ xenbus_dev_error(dev, err, "creating vbd structure");
+ return;
+ }
+
+ /* Pass in NULL node to skip exist test. */
+ frontend_changed(&be->watch, NULL);
+ }
+}
+
+static int blkback_probe(struct xenbus_device *dev,
+ const struct xenbus_device_id *id)
+{
+ struct backend_info *be;
+ char *frontend;
+ int err;
+
+ be = kmalloc(sizeof(*be), GFP_KERNEL);
+ if (!be) {
+ xenbus_dev_error(dev, -ENOMEM, "allocating backend structure");
+ return -ENOMEM;
+ }
+
+ memset(be, 0, sizeof(*be));
+
+ be->dev = dev;
+ be->backend_watch.node = dev->nodename;
+ be->backend_watch.callback = backend_changed;
+ err = register_xenbus_watch(&be->backend_watch);
+ if (err) {
+ xenbus_dev_error(dev, err, "adding backend watch on %s",
+ dev->nodename);
+ goto free_be;
+ }
+
+ dev->data = be;
frontend = NULL;
err = xenbus_gather(dev->nodename,
"frontend-id", "%li", &be->frontend_id,
"frontend", NULL, &frontend,
NULL);
- if (XENBUS_EXIST_ERR(err) ||
- strlen(frontend) == 0 || !xenbus_exists(frontend, "")) {
+ if (XENBUS_EXIST_ERR(err))
+ goto free_be;
+ if (frontend &&
+ (strlen(frontend) == 0 || !xenbus_exists(frontend, ""))) {
/* If we can't get a frontend path and a frontend-id,
* then our bus-id is no longer valid and we need to
* destroy the backend device.
*/
- goto device_fail;
+ goto free_be;
}
if (err < 0) {
xenbus_dev_error(dev, err,
"reading %s/frontend or frontend-id",
dev->nodename);
- goto device_fail;
- }
-
- if (!be->frontpath || strcmp(frontend, be->frontpath)) {
- if (be->watch.node)
- unregister_xenbus_watch(&be->watch);
- if (be->frontpath)
- kfree(be->frontpath);
- be->frontpath = frontend;
- frontend = NULL;
- be->watch.node = be->frontpath;
- be->watch.callback = frontend_changed;
- err = register_xenbus_watch(&be->watch);
- if (err) {
- be->watch.node = NULL;
- xenbus_dev_error(dev, err,
- "adding frontend watch on %s",
- be->frontpath);
- goto device_fail;
- }
- }
-
- err = xenbus_scanf(dev->nodename, "physical-device", "%li", &pdev);
- if (XENBUS_EXIST_ERR(err))
- goto out;
- if (err < 0) {
- xenbus_dev_error(dev, err, "reading physical-device");
- goto device_fail;
- }
- if (be->pdev && be->pdev != pdev) {
- printk(KERN_WARNING
- "changing physical-device not supported\n");
- goto device_fail;
- }
- be->pdev = pdev;
-
- /* If there's a read-only node, we're read only. */
- p = xenbus_read(dev->nodename, "read-only", NULL);
- if (!IS_ERR(p)) {
- be->readonly = 1;
- kfree(p);
- }
-
- if (be->blkif == NULL) {
- /* Front end dir is a number, which is used as the handle. */
- p = strrchr(be->frontpath, '/') + 1;
- handle = simple_strtoul(p, NULL, 0);
-
- be->blkif = alloc_blkif(be->frontend_id);
- if (IS_ERR(be->blkif)) {
- err = PTR_ERR(be->blkif);
- be->blkif = NULL;
- xenbus_dev_error(dev, err, "creating block interface");
- goto device_fail;
- }
-
- err = vbd_create(be->blkif, handle, be->pdev, be->readonly);
- if (err) {
- xenbus_dev_error(dev, err, "creating vbd structure");
- goto device_fail;
- }
-
- frontend_changed(&be->watch, be->frontpath);
- }
-
- out:
+ goto free_be;
+ }
+
+ be->frontpath = frontend;
+ be->watch.node = be->frontpath;
+ be->watch.callback = frontend_changed;
+ err = register_xenbus_watch(&be->watch);
+ if (err) {
+ be->watch.node = NULL;
+ xenbus_dev_error(dev, err,
+ "adding frontend watch on %s",
+ be->frontpath);
+ goto free_be;
+ }
+
+ backend_changed(&be->backend_watch, dev->nodename);
+ return err;
+
+ free_be:
if (frontend)
kfree(frontend);
- return;
-
- device_fail:
- device_unregister(&be->dev->dev);
- goto out;
-}
-
-static int blkback_probe(struct xenbus_device *dev,
- const struct xenbus_device_id *id)
-{
- struct backend_info *be;
- int err;
-
- be = kmalloc(sizeof(*be), GFP_KERNEL);
- if (!be) {
- xenbus_dev_error(dev, -ENOMEM, "allocating backend structure");
- return -ENOMEM;
- }
-
- memset(be, 0, sizeof(*be));
-
- be->dev = dev;
- be->backend_watch.node = dev->nodename;
- be->backend_watch.callback = backend_changed;
- err = register_xenbus_watch(&be->backend_watch);
- if (err) {
- xenbus_dev_error(dev, err, "adding backend watch on %s",
- dev->nodename);
- goto free_be;
- }
-
- dev->data = be;
-
- backend_changed(&be->backend_watch, dev->nodename);
- return err;
- free_be:
kfree(be);
return err;
}
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