storage: Introduce APIs to search/scan storage pool volumes list

Introduce virStoragePoolObjForEachVolume to scan each volume
calling the passed callback function until all volumes have been
processed in the storage pool volume list, unless the callback
function returns an error.

Introduce virStoragePoolObjSearchVolume to search each volume
calling the passed callback function until it returns true
indicating that the desired volume was found.

Signed-off-by: John Ferlan <jferlan@redhat.com>

src/conf/virstorageobj.c

@@ -319,6 +319,38 @@ virStoragePoolObjGetVolumesCount(virStoragePoolObjPtr obj)
 }
 
 
+int
+virStoragePoolObjForEachVolume(virStoragePoolObjPtr obj,
+                               virStorageVolObjListIterator iter,
+                               const void *opaque)
+{
+    size_t i;
+
+    for (i = 0; i < obj->volumes.count; i++) {
+        if (iter(obj->volumes.objs[i], opaque) < 0)
+            return -1;
+    }
+
+    return 0;
+}
+
+
+virStorageVolDefPtr
+virStoragePoolObjSearchVolume(virStoragePoolObjPtr obj,
+                              virStorageVolObjListSearcher iter,
+                              const void *opaque)
+{
+    size_t i;
+
+    for (i = 0; i < obj->volumes.count; i++) {
+        if (iter(obj->volumes.objs[i], opaque))
+            return obj->volumes.objs[i];
+    }
+
+    return NULL;
+}
+
+
 virStorageVolDefPtr
 virStorageVolDefFindByKey(virStoragePoolObjPtr obj,
                           const char *key)

src/conf/virstorageobj.h

@@ -147,6 +147,24 @@ virStoragePoolObjRemoveVol(virStoragePoolObjPtr obj,
 size_t
 virStoragePoolObjGetVolumesCount(virStoragePoolObjPtr obj);
 
+typedef int
+(*virStorageVolObjListIterator)(virStorageVolDefPtr voldef,
+                                const void *opaque);
+
+int
+virStoragePoolObjForEachVolume(virStoragePoolObjPtr obj,
+                               virStorageVolObjListIterator iter,
+                               const void *opaque);
+
+typedef bool
+(*virStorageVolObjListSearcher)(virStorageVolDefPtr voldef,
+                                const void *opaque);
+
+virStorageVolDefPtr
+virStoragePoolObjSearchVolume(virStoragePoolObjPtr obj,
+                              virStorageVolObjListSearcher iter,
+                              const void *opaque);
+
 virStorageVolDefPtr
 virStorageVolDefFindByKey(virStoragePoolObjPtr obj,
                           const char *key);

src/libvirt_private.syms

@@ -1061,6 +1061,7 @@ virStoragePoolObjDefUseNewDef;
 virStoragePoolObjDeleteDef;
 virStoragePoolObjFindByName;
 virStoragePoolObjFindByUUID;
+virStoragePoolObjForEachVolume;
 virStoragePoolObjGetAsyncjobs;
 virStoragePoolObjGetAutostartLink;
 virStoragePoolObjGetConfigFile;
@@ -1083,6 +1084,7 @@ virStoragePoolObjNumOfVolumes;
 virStoragePoolObjRemove;
 virStoragePoolObjRemoveVol;
 virStoragePoolObjSaveDef;
+virStoragePoolObjSearchVolume;
 virStoragePoolObjSetActive;
 virStoragePoolObjSetAutostart;
 virStoragePoolObjSetConfigFile;

src/storage/storage_backend_disk.c

@@ -43,6 +43,17 @@ VIR_LOG_INIT("storage.storage_backend_disk");
 
 #define SECTOR_SIZE 512
 
+static bool
+virStorageVolPartFindExtended(virStorageVolDefPtr def,
+                              const void *opaque ATTRIBUTE_UNUSED)
+{
+    if (def->source.partType == VIR_STORAGE_VOL_DISK_TYPE_EXTENDED)
+        return true;
+
+    return false;
+}
+
+
 static int
 virStorageBackendDiskMakeDataVol(virStoragePoolObjPtr pool,
                                  char **const groups,
@@ -191,16 +202,13 @@ virStorageBackendDiskMakeDataVol(virStoragePoolObjPtr pool,
 
     /* Find the extended partition and increase the allocation value */
     if (vol->source.partType == VIR_STORAGE_VOL_DISK_TYPE_LOGICAL) {
-        size_t i;
+        virStorageVolDefPtr voldef;
 
-        for (i = 0; i < pool->volumes.count; i++) {
-            if (pool->volumes.objs[i]->source.partType ==
-                VIR_STORAGE_VOL_DISK_TYPE_EXTENDED) {
-                pool->volumes.objs[i]->target.allocation +=
-                    vol->target.allocation;
-                break;
-            }
-        }
+        voldef = virStoragePoolObjSearchVolume(pool,
+                                               virStorageVolPartFindExtended,
+                                               NULL);
+        if (voldef)
+            voldef->target.allocation += vol->target.allocation;
     }
 
     if (STRNEQ(groups[2], "metadata"))
@@ -523,6 +531,25 @@ virStorageBackendDiskBuildPool(virConnectPtr conn ATTRIBUTE_UNUSED,
     return ret;
 }
 
+
+struct virStorageVolNumData {
+    int count;
+};
+
+static int
+virStorageVolNumOfPartTypes(virStorageVolDefPtr def,
+                            const void *opaque)
+{
+    struct virStorageVolNumData *data = (struct virStorageVolNumData *)opaque;
+
+    if (def->source.partType == VIR_STORAGE_VOL_DISK_TYPE_PRIMARY ||
+        def->source.partType == VIR_STORAGE_VOL_DISK_TYPE_EXTENDED)
+        data->count++;
+
+    return 0;
+}
+
+
 /**
  * Decides what kind of partition type that should be created.
  * Important when the partition table is of msdos type
@@ -530,19 +557,16 @@ virStorageBackendDiskBuildPool(virConnectPtr conn ATTRIBUTE_UNUSED,
 static int
 virStorageBackendDiskPartTypeToCreate(virStoragePoolObjPtr pool)
 {
+    struct virStorageVolNumData data = { .count = 0 };
+
     if (pool->def->source.format == VIR_STORAGE_POOL_DISK_DOS) {
         /* count primary and extended partitions,
            can't be more than 3 to create a new primary partition */
-        size_t i;
-        int count = 0;
-        for (i = 0; i < pool->volumes.count; i++) {
-            int partType = pool->volumes.objs[i]->source.partType;
-            if (partType == VIR_STORAGE_VOL_DISK_TYPE_PRIMARY ||
-                partType == VIR_STORAGE_VOL_DISK_TYPE_EXTENDED)
-                count++;
+        if (virStoragePoolObjForEachVolume(pool, virStorageVolNumOfPartTypes,
+                                           &data) == 0) {
+            if (data.count >= 4)
+                return VIR_STORAGE_VOL_DISK_TYPE_LOGICAL;
         }
-        if (count >= 4)
-            return VIR_STORAGE_VOL_DISK_TYPE_LOGICAL;
     }
 
     /* for all other cases, all partitions are primary */
@@ -554,7 +578,6 @@ virStorageBackendDiskPartFormat(virStoragePoolObjPtr pool,
                                 virStorageVolDefPtr vol,
                                 char** partFormat)
 {
-    size_t i;
     if (pool->def->source.format == VIR_STORAGE_POOL_DISK_DOS) {
         const char *partedFormat;
         partedFormat = virStoragePartedFsTypeToString(vol->target.format);
@@ -565,13 +588,12 @@ virStorageBackendDiskPartFormat(virStoragePoolObjPtr pool,
         }
         if (vol->target.format == VIR_STORAGE_VOL_DISK_EXTENDED) {
             /* make sure we don't have an extended partition already */
-            for (i = 0; i < pool->volumes.count; i++) {
-                if (pool->volumes.objs[i]->source.partType ==
-                    VIR_STORAGE_VOL_DISK_TYPE_EXTENDED) {
+            if (virStoragePoolObjSearchVolume(pool,
+                                              virStorageVolPartFindExtended,
+                                              NULL)) {
                     virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                                    _("extended partition already exists"));
                     return -1;
-                }
             }
             if (VIR_STRDUP(*partFormat, partedFormat) < 0)
                 return -1;
@@ -587,18 +609,16 @@ virStorageBackendDiskPartFormat(virStoragePoolObjPtr pool,
                 break;
             case VIR_STORAGE_VOL_DISK_TYPE_LOGICAL:
                 /* make sure we have an extended partition */
-                for (i = 0; i < pool->volumes.count; i++) {
-                    if (pool->volumes.objs[i]->source.partType ==
-                        VIR_STORAGE_VOL_DISK_TYPE_EXTENDED) {
-                        if (virAsprintf(partFormat, "logical %s",
-                                        partedFormat) < 0)
-                            return -1;
-                        break;
-                    }
-                }
-                if (i == virStoragePoolObjGetVolumesCount(pool)) {
-                    virReportError(VIR_ERR_INTERNAL_ERROR,
-                                   "%s", _("no extended partition found and no primary partition available"));
+                if (virStoragePoolObjSearchVolume(pool,
+                                                  virStorageVolPartFindExtended,
+                                                  NULL)) {
+                    if (virAsprintf(partFormat, "logical %s",
+                                    partedFormat) < 0)
+                        return -1;
+                } else {
+                    virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                                   _("no extended partition found and no "
+                                     "primary partition available"));
                     return -1;
                 }
                 break;