qemu: Merge qemuCheckSharedDisk into qemuAddSharedDisk

Based on moving various checking into qemuAddSharedDisk, this
avoids the caller using it in wrong ways. Also this adds two
new checking for qemuCheckSharedDisk (disk device not 'lun'
and kernel doesn't support unpriv_sgio simply returns 0).

src/qemu/qemu_conf.c

@@ -847,6 +847,75 @@ qemuGetSharedDiskKey(const char *disk_path)
     return key;
 }
 
+/* Check if a shared disk's setting conflicts with the conf
+ * used by other domain(s). Currently only checks the sgio
+ * setting. Note that this should only be called for disk with
+ * block source.
+ *
+ * Returns 0 if no conflicts, otherwise returns -1.
+ */
+static int
+qemuCheckSharedDisk(virHashTablePtr sharedDisks,
+                    virDomainDiskDefPtr disk)
+{
+    int val;
+    size_t *ref = NULL;
+    char *sysfs_path = NULL;
+    char *key = NULL;
+    int ret = 0;
+
+    /* The only conflicts between shared disk we care about now
+     * is sgio setting, which is only valid for device='lun'.
+     */
+    if (disk->device != VIR_DOMAIN_DISK_DEVICE_LUN)
+        return 0;
+
+    if (!(sysfs_path = virGetUnprivSGIOSysfsPath(disk->src, NULL))) {
+        ret = -1;
+        goto cleanup;
+    }
+
+    /* It can't be conflict if unpriv_sgio is not supported
+     * by kernel.
+     */
+    if (!virFileExists(sysfs_path))
+        goto cleanup;
+
+
+    if (!(key = qemuGetSharedDiskKey(disk->src))) {
+        ret = -1;
+        goto cleanup;
+    }
+
+    /* It can't be conflict if no other domain is
+     * is sharing it.
+     */
+    if (!(ref = virHashLookup(sharedDisks, key)))
+        goto cleanup;
+
+    if (virGetDeviceUnprivSGIO(disk->src, NULL, &val) < 0) {
+        ret = -1;
+        goto cleanup;
+    }
+
+    if ((val == 0 &&
+         (disk->sgio == VIR_DOMAIN_DISK_SGIO_FILTERED ||
+          disk->sgio == VIR_DOMAIN_DISK_SGIO_DEFAULT)) ||
+        (val == 1 &&
+         disk->sgio == VIR_DOMAIN_DISK_SGIO_UNFILTERED))
+        goto cleanup;
+
+    virReportError(VIR_ERR_OPERATION_INVALID,
+                   _("sgio of shared disk '%s' conflicts with other "
+                     "active domains"), disk->src);
+    ret = -1;
+
+cleanup:
+    VIR_FREE(sysfs_path);
+    VIR_FREE(key);
+    return ret;
+}
+
 /* Increase ref count if the entry already exists, otherwise
  * add a new entry.
  */
@@ -867,6 +936,9 @@ qemuAddSharedDisk(virQEMUDriverPtr driver,
         return 0;
 
     qemuDriverLock(driver);
+    if (qemuCheckSharedDisk(driver->sharedDisks, disk) < 0)
+        goto cleanup;
+
     if (!(key = qemuGetSharedDiskKey(disk->src)))
         goto cleanup;
 

src/qemu/qemu_driver.c

@@ -5714,11 +5714,6 @@ qemuDomainAttachDeviceDiskLive(virConnectPtr conn,
         goto end;
     }
 
-    if (disk->type == VIR_DOMAIN_DISK_TYPE_BLOCK &&
-        disk->shared &&
-        (qemuCheckSharedDisk(driver, disk) < 0))
-        goto end;
-
     if (qemuDomainDetermineDiskChain(driver, disk, false) < 0)
         goto end;
 

src/qemu/qemu_process.c

@@ -3477,56 +3477,6 @@ qemuSetUnprivSGIO(virDomainDiskDefPtr disk)
     return 0;
 }
 
-/* Check if a shared disk's setting conflicts with the conf
- * used by other domain(s). Currently only checks the sgio
- * setting. Note that this should only be called for disk with
- * block source.
- *
- * Returns 0 if no conflicts, otherwise returns -1.
- */
-int
-qemuCheckSharedDisk(virQEMUDriverPtr driver,
-                    virDomainDiskDefPtr disk)
-{
-    int val;
-    size_t *ref = NULL;
-    char *key = NULL;
-    int ret = 0;
-
-    if (!(key = qemuGetSharedDiskKey(disk->src)))
-        return -1;
-
-    /* It can't be conflict if no other domain is
-     * is sharing it.
-     */
-    if (!(ref = virHashLookup(driver->sharedDisks, key)))
-        goto cleanup;
-
-    if (ref == (void *)0x1)
-        goto cleanup;
-
-    if (virGetDeviceUnprivSGIO(disk->src, NULL, &val) < 0) {
-        ret = -1;
-        goto cleanup;
-    }
-
-    if ((val == 0 &&
-         (disk->sgio == VIR_DOMAIN_DISK_SGIO_FILTERED ||
-          disk->sgio == VIR_DOMAIN_DISK_SGIO_DEFAULT)) ||
-        (val == 1 &&
-         disk->sgio == VIR_DOMAIN_DISK_SGIO_UNFILTERED))
-        goto cleanup;
-
-    virReportError(VIR_ERR_OPERATION_INVALID,
-                   _("sgio of shared disk '%s' conflicts with other "
-                     "active domains"), disk->src);
-    ret = -1;
-
-cleanup:
-    VIR_FREE(key);
-    return ret;
-}
-
 int qemuProcessStart(virConnectPtr conn,
                      virQEMUDriverPtr driver,
                      virDomainObjPtr vm,
@@ -3883,9 +3833,6 @@ int qemuProcessStart(virConnectPtr conn,
         if (qemuAddSharedDisk(driver, disk) < 0)
             goto cleanup;
 
-        if (qemuCheckSharedDisk(driver, disk) < 0)
-            goto cleanup;
-
         if (qemuSetUnprivSGIO(disk) < 0)
             goto cleanup;
     }

src/qemu/qemu_process.h

@@ -99,7 +99,4 @@ virBitmapPtr qemuPrepareCpumap(virQEMUDriverPtr driver,
                                virBitmapPtr nodemask);
 int qemuSetUnprivSGIO(virDomainDiskDefPtr disk);
 
-int qemuCheckSharedDisk(virQEMUDriverPtr driver,
-                        virDomainDiskDefPtr disk);
-
 #endif /* __QEMU_PROCESS_H__ */