block: Eliminate BlockDriverState member device_name[]

device_name[] can become non-empty only in bdrv_new_root() and
bdrv_move_feature_fields().  The latter is used only to undo damage
done by bdrv_swap().  The former is called only by blk_new_with_bs().
Therefore, when a BlockDriverState's device_name[] is non-empty, then
it's been created with a BlockBackend, and vice versa.  Furthermore,
blk_new_with_bs() keeps the two names equal.

Therefore, device_name[] is redundant.  Eliminate it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

11 files changed, 18 insertions, 17 deletions

diff --git a/block/mirror.c b/block/mirror.c
index 18b18e0353..829be2f88a 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -567,7 +567,8 @@ static void mirror_complete(BlockJob *job, Error **errp)
         return;
     }
     if (!s->synced) {
-        error_set(errp, QERR_BLOCK_JOB_NOT_READY, job->bs->device_name);
+        error_set(errp, QERR_BLOCK_JOB_NOT_READY,
+                  bdrv_get_device_name(job->bs));
         return;
     }
 
diff --git a/block/qapi.c b/block/qapi.c
index 9733ebd328..d071ee564e 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -272,7 +272,7 @@ void bdrv_query_info(BlockDriverState *bs,
     BlockDriverState *bs0;
     ImageInfo **p_image_info;
     Error *local_err = NULL;
-    info->device = g_strdup(bs->device_name);
+    info->device = g_strdup(bdrv_get_device_name(bs));
     info->type = g_strdup("unknown");
     info->locked = bdrv_dev_is_medium_locked(bs);
     info->removable = bdrv_dev_has_removable_media(bs);
@@ -327,9 +327,9 @@ static BlockStats *bdrv_query_stats(const BlockDriverState *bs)
 
     s = g_malloc0(sizeof(*s));
 
-    if (bs->device_name[0]) {
+    if (bdrv_get_device_name(bs)[0]) {
         s->has_device = true;
-        s->device = g_strdup(bs->device_name);
+        s->device = g_strdup(bdrv_get_device_name(bs));
     }
 
     s->stats = g_malloc0(sizeof(*s->stats));
diff --git a/block/qcow.c b/block/qcow.c
index a87bd692f0..ece22697a6 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -124,7 +124,7 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags,
         snprintf(version, sizeof(version), "QCOW version %" PRIu32,
                  header.version);
         error_set(errp, QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
-                  bs->device_name, "qcow", version);
+                  bdrv_get_device_name(bs), "qcow", version);
         ret = -ENOTSUP;
         goto fail;
     }
@@ -231,7 +231,7 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags,
     /* Disable migration when qcow images are used */
     error_set(&s->migration_blocker,
               QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
-              "qcow", bs->device_name, "live migration");
+              "qcow", bdrv_get_device_name(bs), "live migration");
     migrate_add_blocker(s->migration_blocker);
 
     qemu_co_mutex_init(&s->lock);
diff --git a/block/qcow2.c b/block/qcow2.c
index fb28493c02..156a219993 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -206,8 +206,8 @@ static void GCC_FMT_ATTR(3, 4) report_unsupported(BlockDriverState *bs,
     vsnprintf(msg, sizeof(msg), fmt, ap);
     va_end(ap);
 
-    error_set(errp, QERR_UNKNOWN_BLOCK_FORMAT_FEATURE, bs->device_name, "qcow2",
-              msg);
+    error_set(errp, QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
+              bdrv_get_device_name(bs), "qcow2", msg);
 }
 
 static void report_unsupported_feature(BlockDriverState *bs,
diff --git a/block/qed.c b/block/qed.c
index e2316d7ff0..7f03c26227 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -408,7 +408,7 @@ static int bdrv_qed_open(BlockDriverState *bs, QDict *options, int flags,
         snprintf(buf, sizeof(buf), "%" PRIx64,
             s->header.features & ~QED_FEATURE_MASK);
         error_set(errp, QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
-            bs->device_name, "QED", buf);
+            bdrv_get_device_name(bs), "QED", buf);
         return -ENOTSUP;
     }
     if (!qed_is_cluster_size_valid(s->header.cluster_size)) {
diff --git a/block/quorum.c b/block/quorum.c
index 7687466733..6ce5904824 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -226,8 +226,8 @@ static void quorum_report_bad(QuorumAIOCB *acb, char *node_name, int ret)
 
 static void quorum_report_failure(QuorumAIOCB *acb)
 {
-    const char *reference = acb->common.bs->device_name[0] ?
-                            acb->common.bs->device_name :
+    const char *reference = bdrv_get_device_name(acb->common.bs)[0] ?
+                            bdrv_get_device_name(acb->common.bs) :
                             acb->common.bs->node_name;
 
     qapi_event_send_quorum_failure(reference, acb->sector_num,
diff --git a/block/vdi.c b/block/vdi.c
index cfa08b0b93..9604721476 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -490,7 +490,7 @@ static int vdi_open(BlockDriverState *bs, QDict *options, int flags,
     /* Disable migration when vdi images are used */
     error_set(&s->migration_blocker,
               QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
-              "vdi", bs->device_name, "live migration");
+              "vdi", bdrv_get_device_name(bs), "live migration");
     migrate_add_blocker(s->migration_blocker);
 
     return 0;
diff --git a/block/vhdx.c b/block/vhdx.c
index b0464487a5..12bfe75e51 100644
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -1004,7 +1004,7 @@ static int vhdx_open(BlockDriverState *bs, QDict *options, int flags,
     /* Disable migration when VHDX images are used */
     error_set(&s->migration_blocker,
             QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
-            "vhdx", bs->device_name, "live migration");
+            "vhdx", bdrv_get_device_name(bs), "live migration");
     migrate_add_blocker(s->migration_blocker);
 
     return 0;
diff --git a/block/vmdk.c b/block/vmdk.c
index 4ae6c75310..673d3f5fb4 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -657,7 +657,7 @@ static int vmdk_open_vmdk4(BlockDriverState *bs,
         snprintf(buf, sizeof(buf), "VMDK version %" PRId32,
                  le32_to_cpu(header.version));
         error_set(errp, QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
-                  bs->device_name, "vmdk", buf);
+                  bdrv_get_device_name(bs), "vmdk", buf);
         return -ENOTSUP;
     } else if (le32_to_cpu(header.version) == 3 && (flags & BDRV_O_RDWR)) {
         /* VMware KB 2064959 explains that version 3 added support for
@@ -939,7 +939,7 @@ static int vmdk_open(BlockDriverState *bs, QDict *options, int flags,
     /* Disable migration when VMDK images are used */
     error_set(&s->migration_blocker,
               QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
-              "vmdk", bs->device_name, "live migration");
+              "vmdk", bdrv_get_device_name(bs), "live migration");
     migrate_add_blocker(s->migration_blocker);
     g_free(buf);
     return 0;
diff --git a/block/vpc.c b/block/vpc.c
index e08144a76e..38c4f02fff 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -320,7 +320,7 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags,
     /* Disable migration when VHD images are used */
     error_set(&s->migration_blocker,
               QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
-              "vpc", bs->device_name, "live migration");
+              "vpc", bdrv_get_device_name(bs), "live migration");
     migrate_add_blocker(s->migration_blocker);
 
     return 0;
diff --git a/block/vvfat.c b/block/vvfat.c
index 6c9fde017b..cefe3a4f79 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -1182,7 +1182,7 @@ static int vvfat_open(BlockDriverState *bs, QDict *options, int flags,
     if (s->qcow) {
         error_set(&s->migration_blocker,
                   QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
-                  "vvfat (rw)", bs->device_name, "live migration");
+                  "vvfat (rw)", bdrv_get_device_name(bs), "live migration");
         migrate_add_blocker(s->migration_blocker);
     }