[libvirt] [PATCHv2 2/2] storage: Split out volume wiping as separate backend function

[Peter Krempa]

For non-local storage drivers we can't expect to use the "scrub" tool to
wipe the volume. Split the code into a separate backend function so that
we can add protocol specific code later.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1118710
---
 src/storage/storage_backend.h         |  6 ++++++
 src/storage/storage_backend_disk.c    |  1 +
 src/storage/storage_backend_fs.c      |  3 +++
 src/storage/storage_backend_iscsi.c   |  1 +
 src/storage/storage_backend_logical.c |  1 +
 src/storage/storage_backend_mpath.c   |  1 +
 src/storage/storage_backend_scsi.c    |  1 +
 src/storage/storage_driver.c          | 10 +++++++---
 8 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/src/storage/storage_backend.h b/src/storage/storage_backend.h
index 5e251d7..e48da5b 100644
--- a/src/storage/storage_backend.h
+++ b/src/storage/storage_backend.h
@@ -87,6 +87,11 @@ typedef int (*virStorageBackendVolumeUpload)(virConnectPtr conn,
                                              unsigned long long offset,
                                              unsigned long long len,
                                              unsigned int flags);
+typedef int (*virStorageBackendVolumeWipe)(virConnectPtr conn,
+                                           virStoragePoolObjPtr pool,
+                                           virStorageVolDefPtr vol,
+                                           unsigned int algorithm,
+                                           unsigned int flags);

 /* File creation/cloning functions used for cloning between backends */
 int virStorageBackendCreateRaw(virConnectPtr conn,
@@ -150,6 +155,7 @@ struct _virStorageBackend {
     virStorageBackendVolumeResize resizeVol;
     virStorageBackendVolumeUpload uploadVol;
     virStorageBackendVolumeDownload downloadVol;
+    virStorageBackendVolumeWipe wipeVol;
 };

 virStorageBackendPtr virStorageBackendForType(int type);
diff --git a/src/storage/storage_backend_disk.c b/src/storage/storage_backend_disk.c
index f900dee..d85f13f 100644
--- a/src/storage/storage_backend_disk.c
+++ b/src/storage/storage_backend_disk.c
@@ -794,4 +794,5 @@ virStorageBackend virStorageBackendDisk = {
     .buildVolFrom = virStorageBackendDiskBuildVolFrom,
     .uploadVol = virStorageBackendVolUploadLocal,
     .downloadVol = virStorageBackendVolDownloadLocal,
+    .wipeVol = virStorageBackendVolWipeLocal,
 };
diff --git a/src/storage/storage_backend_fs.c b/src/storage/storage_backend_fs.c
index 1615c12..58e849f 100644
--- a/src/storage/storage_backend_fs.c
+++ b/src/storage/storage_backend_fs.c
@@ -1291,6 +1291,7 @@ virStorageBackend virStorageBackendDirectory = {
     .resizeVol = virStorageBackendFileSystemVolResize,
     .uploadVol = virStorageBackendVolUploadLocal,
     .downloadVol = virStorageBackendVolDownloadLocal,
+    .wipeVol = virStorageBackendVolWipeLocal,
 };

 #if WITH_STORAGE_FS
@@ -1311,6 +1312,7 @@ virStorageBackend virStorageBackendFileSystem = {
     .resizeVol = virStorageBackendFileSystemVolResize,
     .uploadVol = virStorageBackendVolUploadLocal,
     .downloadVol = virStorageBackendVolDownloadLocal,
+    .wipeVol = virStorageBackendVolWipeLocal,
 };
 virStorageBackend virStorageBackendNetFileSystem = {
     .type = VIR_STORAGE_POOL_NETFS,
@@ -1330,6 +1332,7 @@ virStorageBackend virStorageBackendNetFileSystem = {
     .resizeVol = virStorageBackendFileSystemVolResize,
     .uploadVol = virStorageBackendVolUploadLocal,
     .downloadVol = virStorageBackendVolDownloadLocal,
+    .wipeVol = virStorageBackendVolWipeLocal,
 };


diff --git a/src/storage/storage_backend_iscsi.c b/src/storage/storage_backend_iscsi.c
index 7345571..1d0cf73 100644
--- a/src/storage/storage_backend_iscsi.c
+++ b/src/storage/storage_backend_iscsi.c
@@ -476,4 +476,5 @@ virStorageBackend virStorageBackendISCSI = {
     .findPoolSources = virStorageBackendISCSIFindPoolSources,
     .uploadVol = virStorageBackendVolUploadLocal,
     .downloadVol = virStorageBackendVolDownloadLocal,
+    .wipeVol = virStorageBackendVolWipeLocal,
 };
diff --git a/src/storage/storage_backend_logical.c b/src/storage/storage_backend_logical.c
index faa9a4b..562f019 100644
--- a/src/storage/storage_backend_logical.c
+++ b/src/storage/storage_backend_logical.c
@@ -843,4 +843,5 @@ virStorageBackend virStorageBackendLogical = {
     .deleteVol = virStorageBackendLogicalDeleteVol,
     .uploadVol = virStorageBackendVolUploadLocal,
     .downloadVol = virStorageBackendVolDownloadLocal,
+    .wipeVol = virStorageBackendVolWipeLocal,
 };
diff --git a/src/storage/storage_backend_mpath.c b/src/storage/storage_backend_mpath.c
index 402faa0..f21ae4c 100644
--- a/src/storage/storage_backend_mpath.c
+++ b/src/storage/storage_backend_mpath.c
@@ -289,4 +289,5 @@ virStorageBackend virStorageBackendMpath = {
     .refreshPool = virStorageBackendMpathRefreshPool,
     .uploadVol = virStorageBackendVolUploadLocal,
     .downloadVol = virStorageBackendVolDownloadLocal,
+    .wipeVol = virStorageBackendVolWipeLocal,
 };
diff --git a/src/storage/storage_backend_scsi.c b/src/storage/storage_backend_scsi.c
index 0b44f71..dfb663b 100644
--- a/src/storage/storage_backend_scsi.c
+++ b/src/storage/storage_backend_scsi.c
@@ -730,4 +730,5 @@ virStorageBackend virStorageBackendSCSI = {
     .stopPool = virStorageBackendSCSIStopPool,
     .uploadVol = virStorageBackendVolUploadLocal,
     .downloadVol = virStorageBackendVolDownloadLocal,
+    .wipeVol = virStorageBackendVolWipeLocal,
 };
diff --git a/src/storage/storage_driver.c b/src/storage/storage_driver.c
index 97571e8..441da21 100644
--- a/src/storage/storage_driver.c
+++ b/src/storage/storage_driver.c
@@ -2100,6 +2100,7 @@ storageVolWipePattern(virStorageVolPtr obj,
                       unsigned int algorithm,
                       unsigned int flags)
 {
+    virStorageBackendPtr backend;
     virStoragePoolObjPtr pool = NULL;
     virStorageVolDefPtr vol = NULL;
     int ret = -1;
@@ -2113,7 +2114,7 @@ storageVolWipePattern(virStorageVolPtr obj,
         return -1;
     }

-    if (!(vol = virStorageVolDefFromVol(obj, &pool, NULL)))
+    if (!(vol = virStorageVolDefFromVol(obj, &pool, &backend)))
         return -1;


@@ -2134,10 +2135,13 @@ storageVolWipePattern(virStorageVolPtr obj,
         goto cleanup;
     }

-    if (virStorageBackendVolWipeLocal(obj->conn, pool, vol, algorithm, flags) < 0)
+    if (!backend->wipeVol) {
+        virReportError(VIR_ERR_NO_SUPPORT, "%s",
+                       _("storage pool doesn't support volume wiping"));
         goto cleanup;
+    }

-    ret = 0;
+    ret = backend->wipeVol(obj->conn, pool, vol, algorithm, flags);

  cleanup:
     virStoragePoolObjUnlock(pool);
-- 
2.0.0