conf: return backing information separately from metadata

A couple pieces of virStorageFileMetadata are used only while
collecting information about the chain, and don't need to
live permanently in the struct.  This patch refactors external
callers to collect the information separately, so that the
next patch can remove the fields.

* src/util/virstoragefile.h (virStorageFileGetMetadataFromBuf):
Alter signature.
* src/util/virstoragefile.c (virStorageFileGetMetadataInternal):
Likewise.
(virStorageFileGetMetadataFromFDInternal): Adjust callers.
* src/storage/storage_backend_fs.c (virStorageBackendProbeTarget):
Likewise.
* src/storage/storage_backend_gluster.c
(virStorageBackendGlusterRefreshVol): Likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>

diff --git a/src/storage/storage_backend_fs.c b/src/storage/storage_backend_fs.c
index 5730e3beeec99914697935730ea65f6076bef660..be963d41c86e755901ec24938eece9e536754181 100644 (file)
--- a/src/storage/storage_backend_fs.c
+++ b/src/storage/storage_backend_fs.c
@@ -106,7 +106,9 @@ virStorageBackendProbeTarget(virStorageSourcePtr target,
 
         if (!(meta = virStorageFileGetMetadataFromBuf(target->path,
                                                       header, len,
-                                                      target->format))) {
+                                                      target->format,
+                                                      backingStore,
+                                                      backingStoreFormat))) {
             ret = -1;
             goto error;
         }
@@ -114,25 +116,19 @@ virStorageBackendProbeTarget(virStorageSourcePtr target,
 
     VIR_FORCE_CLOSE(fd);
 
-    if (meta && meta->backingStore) {
-        *backingStore = meta->backingStore;
-        meta->backingStore = NULL;
-        if (meta->backingStoreFormat == VIR_STORAGE_FILE_AUTO &&
-            virStorageIsFile(*backingStore)) {
-            if ((ret = virStorageFileProbeFormat(*backingStore, -1, -1)) < 0) {
-                /* If the backing file is currently unavailable, only log an error,
-                 * but continue. Returning -1 here would disable the whole storage
-                 * pool, making it unavailable for even maintenance. */
-                virReportError(VIR_ERR_INTERNAL_ERROR,
-                               _("cannot probe backing volume format: %s"),
-                               *backingStore);
-                ret = -3;
-            } else {
-                *backingStoreFormat = ret;
-                ret = 0;
-            }
+    if (meta && *backingStore &&
+        *backingStoreFormat == VIR_STORAGE_FILE_AUTO &&
+        virStorageIsFile(*backingStore)) {
+        if ((ret = virStorageFileProbeFormat(*backingStore, -1, -1)) < 0) {
+            /* If the backing file is currently unavailable, only log an error,
+             * but continue. Returning -1 here would disable the whole storage
+             * pool, making it unavailable for even maintenance. */
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("cannot probe backing volume format: %s"),
+                           *backingStore);
+            ret = -3;
         } else {
-            *backingStoreFormat = meta->backingStoreFormat;
+            *backingStoreFormat = ret;
             ret = 0;
         }
     } else {

diff --git a/src/storage/storage_backend_gluster.c b/src/storage/storage_backend_gluster.c
index 2593c1c1a92c0b473e2f505a88bd1ab4da0ea498..e0a25df6ff0bd7e484953bb09187148c8f8be022 100644 (file)
--- a/src/storage/storage_backend_gluster.c
+++ b/src/storage/storage_backend_gluster.c
@@ -298,16 +298,14 @@ virStorageBackendGlusterRefreshVol(virStorageBackendGlusterStatePtr state,
                                                                len)) < 0)
         goto cleanup;
     if (!(meta = virStorageFileGetMetadataFromBuf(name, header, len,
-                                                  vol->target.format)))
+                                                  vol->target.format,
+                                                  &vol->backingStore.path,
+                                                  &vol->backingStore.format)))
         goto cleanup;
 
-    if (meta->backingStore) {
-        vol->backingStore.path = meta->backingStore;
-        meta->backingStore = NULL;
-        vol->backingStore.format = meta->backingStoreFormat;
-        if (vol->backingStore.format < 0)
-            vol->backingStore.format = VIR_STORAGE_FILE_RAW;
-    }
+    if (vol->backingStore.path &&
+        vol->backingStore.format < 0)
+        vol->backingStore.format = VIR_STORAGE_FILE_RAW;
     if (meta->capacity)
         vol->target.capacity = meta->capacity;
     if (meta->encryption) {

diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c
index bc5d7631e3bd1216af33c319d2e6f0d7ba5d6bba..5a4fc4b1dee3a21d9f54c1e3b756eb612b9f8826 100644 (file)
--- a/src/util/virstoragefile.c
+++ b/src/util/virstoragefile.c
@@ -790,13 +790,16 @@ qcow2GetFeatures(virBitmapPtr *features,
  * information about the file and its backing store.  */
 static int ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2)
 ATTRIBUTE_NONNULL(3) ATTRIBUTE_NONNULL(4) ATTRIBUTE_NONNULL(7)
+ATTRIBUTE_NONNULL(8) ATTRIBUTE_NONNULL(9)
 virStorageFileGetMetadataInternal(const char *path,
                                   const char *canonPath,
                                   const char *directory,
                                   char *buf,
                                   size_t len,
                                   int format,
-                                  virStorageFileMetadataPtr meta)
+                                  virStorageFileMetadataPtr meta,
+                                  char **backingStore,
+                                  int *backingFormat)
 {
     int ret = -1;
 
@@ -855,10 +858,9 @@ virStorageFileGetMetadataInternal(const char *path,
     }
 
     if (fileTypeInfo[format].getBackingStore != NULL) {
-        char *backing;
-        int backingFormat;
+        char *backing = NULL;
         int store = fileTypeInfo[format].getBackingStore(&backing,
-                                                         &backingFormat,
+                                                         backingFormat,
                                                          buf, len);
         if (store == BACKING_STORE_INVALID)
             goto done;
@@ -880,23 +882,20 @@ virStorageFileGetMetadataInternal(const char *path,
                     /* the backing file is (currently) unavailable, treat this
                      * file as standalone:
                      * backingStoreRaw is kept to mark broken image chains */
-                    backingFormat = VIR_STORAGE_FILE_NONE;
+                    *backingFormat = VIR_STORAGE_FILE_NONE;
                     VIR_WARN("Backing file '%s' of image '%s' is missing.",
                              meta->backingStoreRaw, path);
 
                 }
             } else {
-                if (VIR_STRDUP(meta->backingStoreRaw, backing) < 0) {
-                    VIR_FREE(backing);
-                    goto cleanup;
-                }
-                backingFormat = VIR_STORAGE_FILE_RAW;
+                *backingStore = backing;
+                backing = NULL;
+                *backingFormat = VIR_STORAGE_FILE_RAW;
             }
             VIR_FREE(backing);
-            meta->backingStoreFormat = backingFormat;
         } else {
             meta->backingStore = NULL;
-            meta->backingStoreFormat = VIR_STORAGE_FILE_NONE;
+            *backingFormat = VIR_STORAGE_FILE_NONE;
         }
     }
 
@@ -980,6 +979,8 @@ virStorageFileProbeFormat(const char *path, uid_t uid, gid_t gid)
  * @buf: header bytes from @path
  * @len: length of @buf
  * @format: expected image format
+ * @backing: output malloc'd name of backing image, if any
+ * @backingFormat: format of @backing
  *
  * Extract metadata about the storage volume with the specified
  * image format. If image format is VIR_STORAGE_FILE_AUTO, it
@@ -989,7 +990,7 @@ virStorageFileProbeFormat(const char *path, uid_t uid, gid_t gid)
  * format, since a malicious guest can turn a raw file into any
  * other non-raw format at will.
  *
- * If the returned meta.backingStoreFormat is VIR_STORAGE_FILE_AUTO
+ * If the returned @backingFormat is VIR_STORAGE_FILE_AUTO
  * it indicates the image didn't specify an explicit format for its
  * backing store. Callers are advised against probing for the
  * backing store format in this case.
@@ -1000,7 +1001,9 @@ virStorageFileMetadataPtr
 virStorageFileGetMetadataFromBuf(const char *path,
                                  char *buf,
                                  size_t len,
-                                 int format)
+                                 int format,
+                                 char **backing,
+                                 int *backingFormat)
 {
     virStorageFileMetadataPtr ret = NULL;
     char *canonPath;
@@ -1013,7 +1016,8 @@ virStorageFileGetMetadataFromBuf(const char *path,
         goto cleanup;
 
     if (virStorageFileGetMetadataInternal(path, canonPath, ".", buf, len,
-                                          format, ret) < 0) {
+                                          format, ret, backing,
+                                          backingFormat) < 0) {
         virStorageFileFreeMetadata(ret);
         ret = NULL;
     }
@@ -1068,7 +1072,9 @@ virStorageFileGetMetadataFromFDInternal(const char *path,
     }
 
     ret = virStorageFileGetMetadataInternal(path, canonPath, directory,
-                                            buf, len, format, meta);
+                                            buf, len, format, meta,
+                                            &meta->backingStoreRaw,
+                                            &meta->backingStoreFormat);
 
     if (ret == 0) {
         if (S_ISREG(sb.st_mode))

diff --git a/src/util/virstoragefile.h b/src/util/virstoragefile.h
index 4da160b7a3bbce06161fb911572ba724a45152f7..edfe9eb3d1bee612edfed31d5fbd797450398362 100644 (file)
--- a/src/util/virstoragefile.h
+++ b/src/util/virstoragefile.h
@@ -295,7 +295,11 @@ virStorageFileMetadataPtr virStorageFileGetMetadataFromFD(const char *path,
 virStorageFileMetadataPtr virStorageFileGetMetadataFromBuf(const char *path,
                                                            char *buf,
                                                            size_t len,
-                                                           int format);
+                                                           int format,
+                                                           char **backing,
+                                                           int *backingFormat)
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(5)
+    ATTRIBUTE_NONNULL(6);
 int virStorageFileChainGetBroken(virStorageFileMetadataPtr chain,
                                  char **broken_file);