[libvirt] [PATCH v2 5/9] virstoragefile: Treat backingStore as a pointer or an array
Matthias Gatto
matthias.gatto at outscale.com
Wed Jan 21 15:29:52 UTC 2015
As explain in the former patchs, backingStore can be treat an array or
a pointer.
If we have only one backingStore we have to use it as a normal ptr
but if there is more backing store, we use it as a pointer's array.
Because it would be complicated to expend backingStore manually, and do
the convertion from a pointer to an array, I've created the
virStorageSourcePushBackingStore function to help.
This function allocate an array of pointer only if there is more than 1 bs.
Because we can not remove a child from a quorum, i didn't create the function
virStorageSourcePopBackingStore.
I've changed virStorageSourceBackingStoreClear, virStorageSourceSetBackingStore
and virStorageSourceGetBackingStore to handle the case where backingStore
is an array.
Signed-off-by: Matthias Gatto <matthias.gatto at outscale.com>
---
src/conf/storage_conf.c | 7 ++-
src/libvirt_private.syms | 1 +
src/storage/storage_backend_fs.c | 2 +
src/storage/storage_backend_logical.c | 2 +-
src/util/virstoragefile.c | 89 ++++++++++++++++++++++++++++++++---
src/util/virstoragefile.h | 2 +
6 files changed, 94 insertions(+), 9 deletions(-)
diff --git a/src/conf/storage_conf.c b/src/conf/storage_conf.c
index fac85fa..41887eb 100644
--- a/src/conf/storage_conf.c
+++ b/src/conf/storage_conf.c
@@ -1343,7 +1343,12 @@ virStorageVolDefParseXML(virStoragePoolDefPtr pool,
if (VIR_ALLOC(backingStorePtr) < 0)
goto error;
- backingStorePtr = virStorageSourceSetBackingStore(&ret->target, backingStorePtr, 0);
+ if (!virStorageSourcePushBackingStore(&ret->target))
+ goto error;
+
+ backingStorePtr = virStorageSourceSetBackingStore(&ret->target,
+ backingStorePtr,
+ ret->target.nBackingStores - 1);
backingStorePtr->path = backingStore;
backingStore = NULL;
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 980235b..5752907 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2033,6 +2033,7 @@ virStorageSourceParseRBDColonString;
virStorageSourcePoolDefFree;
virStorageSourcePoolModeTypeFromString;
virStorageSourcePoolModeTypeToString;
+virStorageSourcePushBackingStore;
virStorageSourceSetBackingStore;
virStorageTypeFromString;
virStorageTypeToString;
diff --git a/src/storage/storage_backend_fs.c b/src/storage/storage_backend_fs.c
index a3b6688..0d8c5ad 100644
--- a/src/storage/storage_backend_fs.c
+++ b/src/storage/storage_backend_fs.c
@@ -112,6 +112,8 @@ virStorageBackendProbeTarget(virStorageSourcePtr target,
if (VIR_ALLOC(backingStore) < 0)
goto cleanup;
+ if (virStorageSourcePushBackingStore(target) == false)
+ goto cleanup;
virStorageSourceSetBackingStore(target, backingStore, 0);
backingStore->type = VIR_STORAGE_TYPE_NETWORK;
backingStore->path = meta->backingStoreRaw;
diff --git a/src/storage/storage_backend_logical.c b/src/storage/storage_backend_logical.c
index fcec31f..cd8de85 100644
--- a/src/storage/storage_backend_logical.c
+++ b/src/storage/storage_backend_logical.c
@@ -148,7 +148,7 @@ virStorageBackendLogicalMakeVol(char **const groups,
* lv is created with "--virtualsize").
*/
if (groups[1] && !STREQ(groups[1], "") && (groups[1][0] != '[')) {
- if (VIR_ALLOC(vol->target.backingStore) < 0)
+ if (virStorageSourcePushBackingStore(&vol->target) == false)
goto cleanup;
if (virAsprintf(&virStorageSourceGetBackingStore(&vol->target, 0)->path, "%s/%s",
diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c
index ba38827..554aa8b 100644
--- a/src/util/virstoragefile.c
+++ b/src/util/virstoragefile.c
@@ -1798,21 +1798,88 @@ virStorageSourcePoolDefCopy(const virStorageSourcePoolDef *src)
}
+/**
+ * virStorageSourceGetBackingStore:
+ * @src: virStorageSourcePtr containing the backing stores
+ * @pos: position of the backing store to get
+ *
+ * return the backingStore at the position of @pos
+ */
virStorageSourcePtr
-virStorageSourceGetBackingStore(const virStorageSource *src,
- size_t pos ATTRIBUTE_UNUSED)
+virStorageSourceGetBackingStore(const virStorageSource *src, size_t pos)
+{
+ if (!src->backingStore || (pos > 1 && pos >= src->nBackingStores))
+ return NULL;
+ if (src->nBackingStores < 2)
+ return src->backingStore;
+ return ((virStorageSourcePtr *)src->backingStore)[pos];
+}
+
+
+/**
+ * virStorageSourcePushBackingStore:
+ * @src: virStorageSourcePtr to allocate the new backing store
+ *
+ * Allocate size for a new backingStorePtr in src->backingStore
+ * and update src->nBackingStores
+ * If we have less than 2 backing stores, we treat src->backingStore
+ * as a pointer otherwise we treat it as an array of virStorageSourcePtr
+ */
+bool
+virStorageSourcePushBackingStore(virStorageSourcePtr src)
{
- return src->backingStore;
+ virStorageSourcePtr tmp;
+ virStorageSourcePtr *tmp2;
+
+ if (!src)
+ return false;
+ if (src->nBackingStores == 1) {
+ /* If we need more than one backing store we need an array
+ * Because we don't want to lose our data from the old Backing Store
+ * we copy the pointer from src->backingStore to src->backingStore[0] */
+ tmp = src->backingStore;
+ if (VIR_ALLOC_N(tmp2, 1) < 0)
+ return false;
+ src->backingStore = (virStorageSourcePtr)tmp2;
+ src->nBackingStores += 1;
+ virStorageSourceSetBackingStore(src, tmp, 0);
+ } else if (src->nBackingStores > 1) {
+ tmp2 = ((virStorageSourcePtr *)src->backingStore);
+ if (VIR_EXPAND_N(tmp2, src->nBackingStores, 1) < 0)
+ return false;
+ src->backingStore = (virStorageSourcePtr)tmp2;
+ } else {
+ /* Most of the time we use only one backingStore
+ * So we don't need to allocate an array */
+ src->nBackingStores += 1;
+ }
+ return true;
}
+/**
+ * virStorageSourceSetBackingStore:
+ * @src: virStorageSourcePtr to hold @backingStore
+ * @backingStore: backingStore to store
+ * @pos: position of the backing store to store
+ *
+ * Set @backingStore at @pos in src->backingStore
+ */
virStorageSourcePtr
virStorageSourceSetBackingStore(virStorageSourcePtr src,
virStorageSourcePtr backingStore,
- size_t pos ATTRIBUTE_UNUSED)
+ size_t pos)
{
- src->backingStore = backingStore;
- return src->backingStore;
+ if (!src || (pos > 1 && pos >= src->nBackingStores))
+ goto error;
+ if (src->nBackingStores > 1) {
+ ((virStorageSourcePtr *)src->backingStore)[pos] = backingStore;
+ } else {
+ src->backingStore = backingStore;
+ }
+ return backingStore;
+ error:
+ return NULL;
}
@@ -2023,6 +2090,8 @@ virStorageSourceIsEmpty(virStorageSourcePtr src)
void
virStorageSourceBackingStoreClear(virStorageSourcePtr def)
{
+ size_t i;
+
if (!def)
return;
@@ -2030,7 +2099,13 @@ virStorageSourceBackingStoreClear(virStorageSourcePtr def)
VIR_FREE(def->backingStoreRaw);
/* recursively free backing chain */
- virStorageSourceFree(virStorageSourceGetBackingStore(def, 0));
+ for (i = 0; i < def->nBackingStores; ++i)
+ virStorageSourceFree(virStorageSourceGetBackingStore(def, i));
+ if (def->nBackingStores > 1) {
+ /* in this case def->backingStores is treat as an array so we have to free it*/
+ VIR_FREE(def->backingStore);
+ }
+ def->nBackingStores = 0;
virStorageSourceSetBackingStore(def, NULL, 0);
}
diff --git a/src/util/virstoragefile.h b/src/util/virstoragefile.h
index d5cf7e6..74c363b 100644
--- a/src/util/virstoragefile.h
+++ b/src/util/virstoragefile.h
@@ -271,6 +271,7 @@ struct _virStorageSource {
/* backing chain of the storage source */
virStorageSourcePtr backingStore;
+ size_t nBackingStores;
/* metadata for storage driver access to remote and local volumes */
virStorageDriverDataPtr drv;
@@ -294,6 +295,7 @@ virStorageSourcePtr virStorageSourceSetBackingStore(virStorageSourcePtr src,
size_t pos);
virStorageSourcePtr virStorageSourceGetBackingStore(const virStorageSource *src,
size_t pos);
+bool virStorageSourcePushBackingStore(virStorageSourcePtr src);
int virStorageFileProbeFormat(const char *path, uid_t uid, gid_t gid);
int virStorageFileProbeFormatFromBuf(const char *path,
--
1.8.3.1
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