bdrv_query_image_info Error parameter added

Inform a user in case qcow2_get_specific_info fails to obtain
QCOW2 image specific information. This patch is preliminary to
the one "qcow2: Add list of bitmaps to ImageInfoSpecificQCow2".

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <1549638368-530182-2-git-send-email-andrey.shinkevich@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

block.c

@@ -4462,11 +4462,12 @@ int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
     return drv->bdrv_get_info(bs, bdi);
 }
 
-ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs)
+ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs,
+                                          Error **errp)
 {
     BlockDriver *drv = bs->drv;
     if (drv && drv->bdrv_get_specific_info) {
-        return drv->bdrv_get_specific_info(bs);
+        return drv->bdrv_get_specific_info(bs, errp);
     }
     return NULL;
 }

block/crypto.c

@@ -594,20 +594,17 @@ static int block_crypto_get_info_luks(BlockDriverState *bs,
 }
 
 static ImageInfoSpecific *
-block_crypto_get_specific_info_luks(BlockDriverState *bs)
+block_crypto_get_specific_info_luks(BlockDriverState *bs, Error **errp)
 {
     BlockCrypto *crypto = bs->opaque;
     ImageInfoSpecific *spec_info;
     QCryptoBlockInfo *info;
 
-    info = qcrypto_block_get_info(crypto->block, NULL);
+    info = qcrypto_block_get_info(crypto->block, errp);
     if (!info) {
         return NULL;
     }
-    if (info->format != Q_CRYPTO_BLOCK_FORMAT_LUKS) {
-        qapi_free_QCryptoBlockInfo(info);
-        return NULL;
-    }
+    assert(info->format == Q_CRYPTO_BLOCK_FORMAT_LUKS);
 
     spec_info = g_new(ImageInfoSpecific, 1);
     spec_info->type = IMAGE_INFO_SPECIFIC_KIND_LUKS;

block/qapi.c

@@ -282,7 +282,12 @@ void bdrv_query_image_info(BlockDriverState *bs,
         info->dirty_flag = bdi.is_dirty;
         info->has_dirty_flag = true;
     }
-    info->format_specific     = bdrv_get_specific_info(bs);
+    info->format_specific = bdrv_get_specific_info(bs, &err);
+    if (err) {
+        error_propagate(errp, err);
+        qapi_free_ImageInfo(info);
+        goto out;
+    }
     info->has_format_specific = info->format_specific != NULL;
 
     backing_filename = bs->backing_file;

block/qcow2.c

@@ -4368,14 +4368,20 @@ static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
     return 0;
 }
 
-static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs)
+static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs,
+                                                  Error **errp)
 {
     BDRVQcow2State *s = bs->opaque;
     ImageInfoSpecific *spec_info;
     QCryptoBlockInfo *encrypt_info = NULL;
+    Error *local_err = NULL;
 
     if (s->crypto != NULL) {
-        encrypt_info = qcrypto_block_get_info(s->crypto, &error_abort);
+        encrypt_info = qcrypto_block_get_info(s->crypto, &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            return NULL;
+        }
     }
 
     spec_info = g_new(ImageInfoSpecific, 1);

block/vmdk.c

@@ -2543,7 +2543,8 @@ static int coroutine_fn vmdk_co_check(BlockDriverState *bs,
     return ret;
 }
 
-static ImageInfoSpecific *vmdk_get_specific_info(BlockDriverState *bs)
+static ImageInfoSpecific *vmdk_get_specific_info(BlockDriverState *bs,
+                                                 Error **errp)
 {
     int i;
     BDRVVmdkState *s = bs->opaque;

include/block/block.h

@@ -478,7 +478,8 @@ const char *bdrv_get_device_name(const BlockDriverState *bs);
 const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
 int bdrv_get_flags(BlockDriverState *bs);
 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
-ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs);
+ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs,
+                                          Error **errp);
 void bdrv_round_to_clusters(BlockDriverState *bs,
                             int64_t offset, int64_t bytes,
                             int64_t *cluster_offset,

include/block/block_int.h

@@ -319,7 +319,8 @@ struct BlockDriver {
                                   const char *name,
                                   Error **errp);
     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
-    ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);
+    ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs,
+                                                 Error **errp);
 
     int coroutine_fn (*bdrv_save_vmstate)(BlockDriverState *bs,
                                           QEMUIOVector *qiov,

qemu-io-cmds.c

@@ -1661,6 +1661,7 @@ static int info_f(BlockBackend *blk, int argc, char **argv)
     BlockDriverState *bs = blk_bs(blk);
     BlockDriverInfo bdi;
     ImageInfoSpecific *spec_info;
+    Error *local_err = NULL;
     char s1[64], s2[64];
     int ret;
 
@@ -1682,7 +1683,11 @@ static int info_f(BlockBackend *blk, int argc, char **argv)
     printf("cluster size: %s\n", s1);
     printf("vm state offset: %s\n", s2);
 
-    spec_info = bdrv_get_specific_info(bs);
+    spec_info = bdrv_get_specific_info(bs, &local_err);
+    if (local_err) {
+        error_report_err(local_err);
+        return -EIO;
+    }
     if (spec_info) {
         printf("Format specific information:\n");
         bdrv_image_info_specific_dump(fprintf, stdout, spec_info);