[libvirt] [PATCH] fix the failure of nodedev-reattach caused by the variables from nodedev-attach

[Guannan Ren]

the "virsh nodedev-reattch" command could return successfully, but the pci device is still 
bound to pci-stub driver. The reason is noddev-reattach trys to use the variables set by 
nodedev-dettach commands. Becuase these variables is not persistent, this is not we expected.
the patch try to fix it.

---
 src/util/pci.c |   74 +++++++++++++++++++------------------------------------
 1 files changed, 26 insertions(+), 48 deletions(-)

diff --git a/src/util/pci.c b/src/util/pci.c
index 46a3a83..d345c3e 100644
--- a/src/util/pci.c
+++ b/src/util/pci.c
@@ -67,9 +67,6 @@ struct _pciDevice {
     unsigned      managed : 1;
 
     /* used by reattach function */
-    unsigned      unbind_from_stub : 1;
-    unsigned      remove_slot : 1;
-    unsigned      reprobe : 1;
 };
 
 struct _pciDeviceList {
@@ -882,14 +879,23 @@ pciUnbindDeviceFromStub(pciDevice *dev, const char *driver)
     if (pciDriverDir(&drvdir, driver) < 0)
         goto cleanup;
 
-    if (!dev->unbind_from_stub)
-        goto remove_slot;
-
-    /* If the device is bound to stub, unbind it.
-     */
     if (pciDeviceFile(&path, dev->name, "driver") < 0)
         goto cleanup;
 
+    /* If the device is bound to a driver instead of pci-stub, do nothing.
+     */ 
+    if (virFileExists(path) && ! virFileLinkPointsTo(path, drvdir)){
+        result = 0;
+        goto cleanup;
+    }
+
+    /* If the device is not bound to any driver, reprobe it. 
+     */
+    if (!virFileExists(path))
+        goto reprobe;
+
+    /* If the device is bound to stub, unbind it.
+     */
     if (virFileExists(drvdir) && virFileLinkPointsTo(path, drvdir)) {
         if (pciDriverFile(&path, driver, "unbind") < 0) {
             goto cleanup;
@@ -902,11 +908,6 @@ pciUnbindDeviceFromStub(pciDevice *dev, const char *driver)
             goto cleanup;
         }
     }
-    dev->unbind_from_stub = 0;
-
-remove_slot:
-    if (!dev->remove_slot)
-        goto reprobe;
 
     /* Xen's pciback.ko wants you to use remove_slot on the specific device */
     if (pciDriverFile(&path, driver, "remove_slot") < 0) {
@@ -919,14 +920,8 @@ remove_slot:
                              dev->name, driver);
         goto cleanup;
     }
-    dev->remove_slot = 0;
 
 reprobe:
-    if (!dev->reprobe) {
-        result = 0;
-        goto cleanup;
-    }
-
     /* Trigger a re-probe of the device is not in the stub's dynamic
      * ID table. If the stub is available, but 'remove_id' isn't
      * available, then re-probing would just cause the device to be
@@ -935,6 +930,12 @@ reprobe:
     if (pciDriverFile(&path, driver, "remove_id") < 0) {
         goto cleanup;
     }
+  
+    /* If the device is still in stub's dynamic ID table,remove it,
+     * otherwise, ignore the error.
+     */
+    if (virFileExists(path) && virFileWriteStr(path, dev->name, 0) < 0){
+    }
 
     if (!virFileExists(drvdir) || virFileExists(path)) {
         if (virFileWriteStr(PCI_SYSFS "drivers_probe", dev->name, 0) < 0) {
@@ -948,11 +949,6 @@ reprobe:
     result = 0;
 
 cleanup:
-    /* do not do it again */
-    dev->unbind_from_stub = 0;
-    dev->remove_slot = 0;
-    dev->reprobe = 0;
-
     VIR_FREE(drvdir);
     VIR_FREE(path);
 
@@ -966,7 +962,6 @@ pciBindDeviceToStub(pciDevice *dev, const char *driver)
     int result = -1;
     char *drvdir = NULL;
     char *path = NULL;
-    int reprobe = 0;
 
     /* check whether the device is already bound to a driver */
     if (pciDriverDir(&drvdir, driver) < 0 ||
@@ -980,7 +975,6 @@ pciBindDeviceToStub(pciDevice *dev, const char *driver)
             result = 0;
             goto cleanup;
         }
-        reprobe = 1;
     }
 
     /* Add the PCI device ID to the stub's dynamic ID table;
@@ -1011,8 +1005,7 @@ pciBindDeviceToStub(pciDevice *dev, const char *driver)
     }
 
     if (virFileLinkPointsTo(path, drvdir)) {
-        dev->unbind_from_stub = 1;
-        dev->remove_slot = 1;
+        result = 0;
         goto remove_id;
     }
 
@@ -1022,7 +1015,7 @@ pciBindDeviceToStub(pciDevice *dev, const char *driver)
      * your root filesystem.
      */
     if (pciDeviceFile(&path, dev->name, "driver/unbind") < 0) {
-        goto cleanup;
+        goto remove_id;
     }
 
     if (virFileExists(path)) {
@@ -1030,9 +1023,8 @@ pciBindDeviceToStub(pciDevice *dev, const char *driver)
             virReportSystemError(errno,
                                  _("Failed to unbind PCI device '%s'"),
                                  dev->name);
-            goto cleanup;
+            goto remove_id;
         }
-        dev->reprobe = reprobe;
     }
 
     /* If the device isn't already bound to pci-stub, try binding it now.
@@ -1054,7 +1046,6 @@ pciBindDeviceToStub(pciDevice *dev, const char *driver)
                                  dev->name, driver);
             goto remove_id;
         }
-        dev->remove_slot = 1;
 
         if (pciDriverFile(&path, driver, "bind") < 0) {
             goto remove_id;
@@ -1066,20 +1057,15 @@ pciBindDeviceToStub(pciDevice *dev, const char *driver)
                                  dev->name, driver);
             goto remove_id;
         }
-        dev->unbind_from_stub = 1;
     }
 
+    result = 0;
 remove_id:
     /* If 'remove_id' exists, remove the device id from pci-stub's dynamic
      * ID table so that 'drivers_probe' works below.
      */
     if (pciDriverFile(&path, driver, "remove_id") < 0) {
-        /* We do not remove PCI ID from pci-stub, and we cannot reprobe it */
-        if (dev->reprobe) {
-            VIR_WARN("Could not remove PCI ID '%s' from %s, and the device "
-                     "cannot be probed again.", dev->id, driver);
-        }
-        dev->reprobe = 0;
+        result = -1;
         goto cleanup;
     }
 
@@ -1087,18 +1073,10 @@ remove_id:
         virReportSystemError(errno,
                              _("Failed to remove PCI ID '%s' from %s"),
                              dev->id, driver);
-
-        /* remove PCI ID from pci-stub failed, and we cannot reprobe it */
-        if (dev->reprobe) {
-            VIR_WARN("Failed to remove PCI ID '%s' from %s, and the device "
-                     "cannot be probed again.", dev->id, driver);
-        }
-        dev->reprobe = 0;
+        result = -1;
         goto cleanup;
     }
 
-    result = 0;
-
 cleanup:
     VIR_FREE(drvdir);
     VIR_FREE(path);
-- 
1.7.1