[Libvirt-cim] [PATCH V2 06/11] DevicePool, reimplement get_diskpool_config with libvirt

17 Dec 2012

Original implemetion may return pools with NULL name if
some pool disappear between two libvirt pool API call. And
caller of this function consider number = 0 as error only
but it original return negative value when error before.
This patch fix it.

V2:
  Use for instead of while in clean up.
  Treat zero pool returned from libvirt as normal instead of error.
  Rebased.

Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
---
 src/Virt_DevicePool.c |   41 +++++++++++++++++++++++++++++++----------
 1 files changed, 31 insertions(+), 10 deletions(-)

diff --git a/src/Virt_DevicePool.c b/src/Virt_DevicePool.c
index 79dc108..3d75bf4 100644
--- a/src/Virt_DevicePool.c
+++ b/src/Virt_DevicePool.c
@@ -117,52 +117,73 @@ int get_disk_pool(virStoragePoolPtr poolptr, struct virt_pool **pool)
         return ret;
 }
 
+/* This function returns the real number of pools, no negative value should be
+   returned, if error happens it returns zero, otherwise return at least 1. */
 static int get_diskpool_config(virConnectPtr conn,
                                struct tmp_disk_pool **_pools)
 {
-        int count = 0;
+        int count = 0, realcount = 0;
         int i;
         char ** names = NULL;
         struct tmp_disk_pool *pools = NULL;
+        int have_err = 0;
 
         count = virConnectNumOfStoragePools(conn);
-        if (count <= 0)
+        if (count < 0) {
+                have_err = 1;
                 goto out;
+        } else if (count == 0) {
+                goto out;
+        }
 
         names = calloc(count, sizeof(char *));
         if (names == NULL) {
                 CU_DEBUG("Failed to alloc space for %i pool names", count);
                 count = 0;
+                have_err = 1;
                 goto out;
         }
 
-        if (virConnectListStoragePools(conn, names, count) == -1) {
+        realcount = virConnectListStoragePools(conn, names, count);
+        if (realcount == -1) {
                 CU_DEBUG("Failed to get storage pools");
-                count = 0;
+                realcount = 0;
+                have_err = 1;
+                goto out;
+        }
+        if (realcount == 0) {
+                CU_DEBUG("zero pools got, but prelist is %d.", count);
                 goto out;
         }
 
-        pools = calloc(count, sizeof(*pools));
+        pools = calloc(realcount, sizeof(*pools));
         if (pools == NULL) {
-                CU_DEBUG("Failed to alloc space for %i pool structs", count);
+                CU_DEBUG("Failed to alloc space for %i pool structs", realcount);
+                realcount = 0;
+                have_err = 1;
                 goto out;
         }
 
-        for (i = 0; i < count; i++) {
+        for (i = 0; i < realcount; i++) {
                 pools[i].tag = strdup(names[i]);
                 pools[i].primordial = false;
+                i++;
         }
 
  out:
-        for (i = 0; i < count; i++)
+        for (i = 0; i < count; i++) {
                 free(names[i]);
+                i++;
+        }
         free(names);
 
-        get_disk_parent(&pools, &count);
+        if (have_err == 0) {
+                get_disk_parent(&pools, &realcount);
+        }
 
         *_pools = pools;
 
-        return count;
+        return realcount;
 }
 
 static bool diskpool_set_capacity(virConnectPtr conn,
-- 
1.7.1

    