[libvirt] [PATCH v6 4/4] nodedev: Remove driver locks around object list mgmt code

John Ferlan jferlan at redhat.com
Thu Jul 20 14:08:15 UTC 2017


Since virnodedeviceobj now has a self-lockable hash table, there's no
need to lock the table from the driver for processing. Thus remove the
locks from the driver for NodeDeviceObjList mgmt.

This includes the test driver as well.

Signed-off-by: John Ferlan <jferlan at redhat.com>
---
 src/node_device/node_device_driver.c | 61 +++++++-----------------------------
 src/node_device/node_device_hal.c    | 16 ++--------
 src/node_device/node_device_udev.c   | 13 +++-----
 src/test/test_driver.c               | 25 +++------------
 4 files changed, 22 insertions(+), 93 deletions(-)

diff --git a/src/node_device/node_device_driver.c b/src/node_device/node_device_driver.c
index 920d877..facfeb6 100644
--- a/src/node_device/node_device_driver.c
+++ b/src/node_device/node_device_driver.c
@@ -174,19 +174,13 @@ nodeNumOfDevices(virConnectPtr conn,
                  const char *cap,
                  unsigned int flags)
 {
-    int ndevs = 0;
-
     if (virNodeNumOfDevicesEnsureACL(conn) < 0)
         return -1;
 
     virCheckFlags(0, -1);
 
-    nodeDeviceLock();
-    ndevs = virNodeDeviceObjListNumOfDevices(driver->devs, conn, cap,
-                                             virNodeNumOfDevicesCheckACL);
-    nodeDeviceUnlock();
-
-    return ndevs;
+    return virNodeDeviceObjListNumOfDevices(driver->devs, conn, cap,
+                                            virNodeNumOfDevicesCheckACL);
 }
 
 
@@ -197,20 +191,14 @@ nodeListDevices(virConnectPtr conn,
                 int maxnames,
                 unsigned int flags)
 {
-    int nnames;
-
     if (virNodeListDevicesEnsureACL(conn) < 0)
         return -1;
 
     virCheckFlags(0, -1);
 
-    nodeDeviceLock();
-    nnames = virNodeDeviceObjListGetNames(driver->devs, conn,
-                                          virNodeListDevicesCheckACL,
-                                          cap, names, maxnames);
-    nodeDeviceUnlock();
-
-    return nnames;
+    return virNodeDeviceObjListGetNames(driver->devs, conn,
+                                        virNodeListDevicesCheckACL,
+                                        cap, names, maxnames);
 }
 
 
@@ -219,19 +207,14 @@ nodeConnectListAllNodeDevices(virConnectPtr conn,
                               virNodeDevicePtr **devices,
                               unsigned int flags)
 {
-    int ret = -1;
-
     virCheckFlags(VIR_CONNECT_LIST_NODE_DEVICES_FILTERS_CAP, -1);
 
     if (virConnectListAllNodeDevicesEnsureACL(conn) < 0)
         return -1;
 
-    nodeDeviceLock();
-    ret = virNodeDeviceObjListExport(conn, driver->devs, devices,
-                                     virConnectListAllNodeDevicesCheckACL,
-                                     flags);
-    nodeDeviceUnlock();
-    return ret;
+    return virNodeDeviceObjListExport(conn, driver->devs, devices,
+                                      virConnectListAllNodeDevicesCheckACL,
+                                      flags);
 }
 
 
@@ -240,11 +223,7 @@ nodeDeviceObjFindByName(const char *name)
 {
     virNodeDeviceObjPtr obj;
 
-    nodeDeviceLock();
-    obj = virNodeDeviceObjListFindByName(driver->devs, name);
-    nodeDeviceUnlock();
-
-    if (!obj) {
+    if (!(obj = virNodeDeviceObjListFindByName(driver->devs, name))) {
         virReportError(VIR_ERR_NO_NODE_DEVICE,
                        _("no node device with matching name '%s'"),
                        name);
@@ -294,11 +273,8 @@ nodeDeviceLookupSCSIHostByWWN(virConnectPtr conn,
 
     virCheckFlags(0, NULL);
 
-    nodeDeviceLock();
-    obj = virNodeDeviceObjListFindSCSIHostByWWNs(driver->devs, wwnn, wwpn);
-    nodeDeviceUnlock();
-
-    if (!obj)
+    if (!(obj = virNodeDeviceObjListFindSCSIHostByWWNs(driver->devs,
+                                                       wwnn, wwpn)))
         return NULL;
 
     def = virNodeDeviceObjGetDef(obj);
@@ -509,13 +485,6 @@ nodeDeviceFindNewDevice(virConnectPtr conn,
     virNodeDevicePtr device = NULL;
     time_t start = 0, now = 0;
 
-    /* The thread that creates the device takes the driver lock, so we
-     * must release it in order to allow the device to be created.
-     * We're not doing anything with the driver pointer at this point,
-     * so it's safe to release it, assuming that the pointer itself
-     * doesn't become invalid.  */
-    nodeDeviceUnlock();
-
     nodeDeviceGetTime(&start);
 
     while ((now - start) < LINUX_NEW_DEVICE_WAIT_TIME) {
@@ -532,8 +501,6 @@ nodeDeviceFindNewDevice(virConnectPtr conn,
             break;
     }
 
-    nodeDeviceLock();
-
     return device;
 }
 
@@ -552,8 +519,6 @@ nodeDeviceCreateXML(virConnectPtr conn,
     virCheckFlags(0, NULL);
     virt_type  = virConnectGetType(conn);
 
-    nodeDeviceLock();
-
     if (!(def = virNodeDeviceDefParseString(xmlDesc, CREATE_DEVICE, virt_type)))
         goto cleanup;
 
@@ -579,7 +544,6 @@ nodeDeviceCreateXML(virConnectPtr conn,
                          "wwnn '%s' and wwpn '%s'"),
                        def->name, wwnn, wwpn);
  cleanup:
-    nodeDeviceUnlock();
     virNodeDeviceDefFree(def);
     VIR_FREE(wwnn);
     VIR_FREE(wwpn);
@@ -601,8 +565,6 @@ nodeDeviceDestroy(virNodeDevicePtr device)
         return -1;
     def = virNodeDeviceObjGetDef(obj);
 
-    nodeDeviceLock();
-
     if (virNodeDeviceDestroyEnsureACL(device->conn, def) < 0)
         goto cleanup;
 
@@ -634,7 +596,6 @@ nodeDeviceDestroy(virNodeDevicePtr device)
     ret = 0;
 
  cleanup:
-    nodeDeviceUnlock();
     virNodeDeviceObjEndAPI(&obj);
     VIR_FREE(parent);
     VIR_FREE(wwnn);
diff --git a/src/node_device/node_device_hal.c b/src/node_device/node_device_hal.c
index 7f246f0..c19e327 100644
--- a/src/node_device/node_device_hal.c
+++ b/src/node_device/node_device_hal.c
@@ -508,20 +508,15 @@ dev_refresh(const char *udi)
     const char *name = hal_name(udi);
     virNodeDeviceObjPtr obj;
 
-    nodeDeviceLock();
     if ((obj = virNodeDeviceObjListFindByName(driver->devs, name))) {
         /* Simply "rediscover" device -- incrementally handling changes
          * to sub-capabilities (like net.80203) is nasty ... so avoid it.
          */
         virNodeDeviceObjListRemove(driver->devs, obj);
-    } else {
-        VIR_DEBUG("no device named %s", name);
-    }
-    nodeDeviceUnlock();
-
-    if (obj) {
         virObjectUnref(obj);
         dev_create(udi);
+    } else {
+        VIR_DEBUG("no device named %s", name);
     }
 }
 
@@ -541,14 +536,12 @@ device_removed(LibHalContext *ctx ATTRIBUTE_UNUSED,
     const char *name = hal_name(udi);
     virNodeDeviceObjPtr obj;
 
-    nodeDeviceLock();
     obj = virNodeDeviceObjListFindByName(driver->devs, name);
     VIR_DEBUG("%s", name);
     if (obj)
         virNodeDeviceObjListRemove(driver->devs, obj);
     else
         VIR_DEBUG("no device named %s", name);
-    nodeDeviceUnlock();
     virObjectUnref(obj);
 }
 
@@ -561,11 +554,8 @@ device_cap_added(LibHalContext *ctx,
     virNodeDeviceObjPtr obj;
     virNodeDeviceDefPtr def;
 
-    nodeDeviceLock();
-    obj = virNodeDeviceObjListFindByName(driver->devs, name);
-    nodeDeviceUnlock();
     VIR_DEBUG("%s %s", cap, name);
-    if (obj) {
+    if ((obj = virNodeDeviceObjListFindByName(driver->devs, name))) {
         def = virNodeDeviceObjGetDef(obj);
         (void)gather_capability(ctx, udi, cap, &def->caps);
         virNodeDeviceObjEndAPI(&obj);
diff --git a/src/node_device/node_device_udev.c b/src/node_device/node_device_udev.c
index 1b10c16..434efd7 100644
--- a/src/node_device/node_device_udev.c
+++ b/src/node_device/node_device_udev.c
@@ -1607,7 +1607,6 @@ udevEventHandleCallback(int watch ATTRIBUTE_UNUSED,
     const char *action = NULL;
     int udev_fd = -1;
 
-    nodeDeviceLock();
     udev_fd = udev_monitor_get_fd(udev_monitor);
     if (fd != udev_fd) {
         virReportError(VIR_ERR_INTERNAL_ERROR,
@@ -1639,7 +1638,6 @@ udevEventHandleCallback(int watch ATTRIBUTE_UNUSED,
 
  cleanup:
     udev_device_unref(device);
-    nodeDeviceUnlock();
     return;
 }
 
@@ -1767,7 +1765,6 @@ nodeStateInitialize(bool privileged,
 {
     udevPrivate *priv = NULL;
     struct udev *udev = NULL;
-    int ret = -1;
 
     if (VIR_ALLOC(priv) < 0)
         return -1;
@@ -1847,18 +1844,16 @@ nodeStateInitialize(bool privileged,
         goto cleanup;
 
     /* Populate with known devices */
-
+    nodeDeviceUnlock();
     if (udevEnumerateDevices(udev) != 0)
         goto cleanup;
 
-    ret = 0;
+    return 0;
 
  cleanup:
     nodeDeviceUnlock();
-
-    if (ret == -1)
-        nodeStateCleanup();
-    return ret;
+    nodeStateCleanup();
+    return -1;
 }
 
 
diff --git a/src/test/test_driver.c b/src/test/test_driver.c
index bb2e7ba..4702690 100644
--- a/src/test/test_driver.c
+++ b/src/test/test_driver.c
@@ -5303,11 +5303,7 @@ testNodeDeviceObjFindByName(testDriverPtr driver,
 {
     virNodeDeviceObjPtr obj;
 
-    testDriverLock(driver);
-    obj = virNodeDeviceObjListFindByName(driver->devs, name);
-    testDriverUnlock(driver);
-
-    if (!obj)
+    if (!(obj = virNodeDeviceObjListFindByName(driver->devs, name)))
         virReportError(VIR_ERR_NO_NODE_DEVICE,
                        _("no node device with matching name '%s'"),
                        name);
@@ -5322,15 +5318,10 @@ testNodeNumOfDevices(virConnectPtr conn,
                      unsigned int flags)
 {
     testDriverPtr driver = conn->privateData;
-    int ndevs = 0;
 
     virCheckFlags(0, -1);
 
-    testDriverLock(driver);
-    ndevs = virNodeDeviceObjListNumOfDevices(driver->devs, conn, cap, NULL);
-    testDriverUnlock(driver);
-
-    return ndevs;
+    return virNodeDeviceObjListNumOfDevices(driver->devs, conn, cap, NULL);
 }
 
 
@@ -5342,16 +5333,11 @@ testNodeListDevices(virConnectPtr conn,
                     unsigned int flags)
 {
     testDriverPtr driver = conn->privateData;
-    int nnames = 0;
 
     virCheckFlags(0, -1);
 
-    testDriverLock(driver);
-    nnames = virNodeDeviceObjListGetNames(driver->devs, conn, NULL,
-                                          cap, names, maxnames);
-    testDriverUnlock(driver);
-
-    return nnames;
+    return virNodeDeviceObjListGetNames(driver->devs, conn, NULL,
+                                        cap, names, maxnames);
 }
 
 
@@ -5566,8 +5552,6 @@ testNodeDeviceCreateXML(virConnectPtr conn,
 
     virCheckFlags(0, NULL);
 
-    testDriverLock(driver);
-
     if (!(def = virNodeDeviceDefParseString(xmlDesc, CREATE_DEVICE, NULL)))
         goto cleanup;
 
@@ -5604,7 +5588,6 @@ testNodeDeviceCreateXML(virConnectPtr conn,
 
  cleanup:
     virNodeDeviceObjEndAPI(&obj);
-    testDriverUnlock(driver);
     virNodeDeviceDefFree(def);
     virObjectUnref(dev);
     VIR_FREE(wwnn);
-- 
2.9.4




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