From e636c8d336489bf3eed5878299e6cc045bbad077 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:17:29 +0000
Subject: [PATCH] debug lk

---
 kernel/drivers/xen/xenbus/xenbus_probe.c |   70 +++++++++++++++++-----------------
 1 files changed, 35 insertions(+), 35 deletions(-)

diff --git a/kernel/drivers/xen/xenbus/xenbus_probe.c b/kernel/drivers/xen/xenbus/xenbus_probe.c
index b911a91..98d8706 100644
--- a/kernel/drivers/xen/xenbus/xenbus_probe.c
+++ b/kernel/drivers/xen/xenbus/xenbus_probe.c
@@ -31,6 +31,7 @@
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#define dev_fmt pr_fmt
 
 #define DPRINTK(fmt, args...)				\
 	pr_debug("xenbus_probe (%s:%d) " fmt ".\n",	\
@@ -51,7 +52,6 @@
 #include <linux/module.h>
 
 #include <asm/page.h>
-#include <asm/pgtable.h>
 #include <asm/xen/hypervisor.h>
 
 #include <xen/xen.h>
@@ -233,9 +233,18 @@
 		return err;
 	}
 
-	err = drv->probe(dev, id);
-	if (err)
+	if (!try_module_get(drv->driver.owner)) {
+		dev_warn(&dev->dev, "failed to acquire module reference on '%s'\n",
+			 drv->driver.name);
+		err = -ESRCH;
 		goto fail;
+	}
+
+	down(&dev->reclaim_sem);
+	err = drv->probe(dev, id);
+	up(&dev->reclaim_sem);
+	if (err)
+		goto fail_put;
 
 	err = watch_otherend(dev);
 	if (err) {
@@ -245,9 +254,10 @@
 	}
 
 	return 0;
+fail_put:
+	module_put(drv->driver.owner);
 fail:
 	xenbus_dev_error(dev, err, "xenbus_dev_probe on %s", dev->nodename);
-	xenbus_switch_state(dev, XenbusStateClosed);
 	return err;
 }
 EXPORT_SYMBOL_GPL(xenbus_dev_probe);
@@ -261,38 +271,29 @@
 
 	free_otherend_watch(dev);
 
-	if (drv->remove)
+	if (drv->remove) {
+		down(&dev->reclaim_sem);
 		drv->remove(dev);
+		up(&dev->reclaim_sem);
+	}
+
+	module_put(drv->driver.owner);
 
 	free_otherend_details(dev);
 
-	xenbus_switch_state(dev, XenbusStateClosed);
+	/*
+	 * If the toolstack has forced the device state to closing then set
+	 * the state to closed now to allow it to be cleaned up.
+	 * Similarly, if the driver does not support re-bind, set the
+	 * closed.
+	 */
+	if (!drv->allow_rebind ||
+	    xenbus_read_driver_state(dev->nodename) == XenbusStateClosing)
+		xenbus_switch_state(dev, XenbusStateClosed);
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(xenbus_dev_remove);
-
-void xenbus_dev_shutdown(struct device *_dev)
-{
-	struct xenbus_device *dev = to_xenbus_device(_dev);
-	unsigned long timeout = 5*HZ;
-
-	DPRINTK("%s", dev->nodename);
-
-	get_device(&dev->dev);
-	if (dev->state != XenbusStateConnected) {
-		pr_info("%s: %s: %s != Connected, skipping\n",
-			__func__, dev->nodename, xenbus_strstate(dev->state));
-		goto out;
-	}
-	xenbus_switch_state(dev, XenbusStateClosing);
-	timeout = wait_for_completion_timeout(&dev->down, timeout);
-	if (!timeout)
-		pr_info("%s: %s timeout closing device\n",
-			__func__, dev->nodename);
- out:
-	put_device(&dev->dev);
-}
-EXPORT_SYMBOL_GPL(xenbus_dev_shutdown);
 
 int xenbus_register_driver_common(struct xenbus_driver *drv,
 				  struct xen_bus_type *bus,
@@ -473,6 +474,7 @@
 		goto fail;
 
 	dev_set_name(&xendev->dev, "%s", devname);
+	sema_init(&xendev->reclaim_sem, 1);
 
 	/* Register with generic device framework. */
 	err = device_register(&xendev->dev);
@@ -607,7 +609,7 @@
 	if (drv->suspend)
 		err = drv->suspend(xdev);
 	if (err)
-		pr_warn("suspend %s failed: %i\n", dev_name(dev), err);
+		dev_warn(dev, "suspend failed: %i\n", err);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(xenbus_dev_suspend);
@@ -626,8 +628,7 @@
 	drv = to_xenbus_driver(dev->driver);
 	err = talk_to_otherend(xdev);
 	if (err) {
-		pr_warn("resume (talk_to_otherend) %s failed: %i\n",
-			dev_name(dev), err);
+		dev_warn(dev, "resume (talk_to_otherend) failed: %i\n", err);
 		return err;
 	}
 
@@ -636,15 +637,14 @@
 	if (drv->resume) {
 		err = drv->resume(xdev);
 		if (err) {
-			pr_warn("resume %s failed: %i\n", dev_name(dev), err);
+			dev_warn(dev, "resume failed: %i\n", err);
 			return err;
 		}
 	}
 
 	err = watch_otherend(xdev);
 	if (err) {
-		pr_warn("resume (watch_otherend) %s failed: %d.\n",
-			dev_name(dev), err);
+		dev_warn(dev, "resume (watch_otherend) failed: %d\n", err);
 		return err;
 	}
 

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