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-rw-r--r--block/backup.c5
-rw-r--r--block/blkdebug.c70
-rw-r--r--block/blklogwrites.c33
-rw-r--r--block/blkverify.c29
-rw-r--r--block/block-backend.c17
-rw-r--r--block/commit.c14
-rw-r--r--block/crypto.c8
-rw-r--r--block/curl.c55
-rw-r--r--block/gluster.c19
-rw-r--r--block/io.c89
-rw-r--r--block/iscsi.c18
-rw-r--r--block/mirror.c3
-rw-r--r--block/nbd-client.c36
-rw-r--r--block/nbd-client.h1
-rw-r--r--block/nbd.c46
-rw-r--r--block/nfs.c54
-rw-r--r--block/null.c32
-rw-r--r--block/nvme.c29
-rw-r--r--block/parallels.c13
-rw-r--r--block/qapi.c16
-rw-r--r--block/qcow.c35
-rw-r--r--block/qcow2-cluster.c3
-rw-r--r--block/qcow2-snapshot.c5
-rw-r--r--block/qcow2.c101
-rw-r--r--block/qed-table.c16
-rw-r--r--block/qed.c38
-rw-r--r--block/quorum.c71
-rw-r--r--block/raw-format.c11
-rw-r--r--block/rbd.c14
-rw-r--r--block/replication.c10
-rw-r--r--block/sheepdog.c12
-rw-r--r--block/snapshot.c25
-rw-r--r--block/ssh.c12
-rw-r--r--block/stream.c7
-rw-r--r--block/throttle.c7
-rw-r--r--block/vhdx-log.c1
-rw-r--r--block/vmdk.c53
-rw-r--r--block/vpc.c7
-rw-r--r--block/vvfat.c12
-rw-r--r--block/vxhs.c11
40 files changed, 628 insertions, 410 deletions
diff --git a/block/backup.c b/block/backup.c
index 435414e964..9988753249 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -107,7 +107,6 @@ static int coroutine_fn backup_cow_with_bounce_buffer(BackupBlockJob *job,
                                                       void **bounce_buffer)
 {
     int ret;
-    struct iovec iov;
     QEMUIOVector qiov;
     BlockBackend *blk = job->common.blk;
     int nbytes;
@@ -119,9 +118,7 @@ static int coroutine_fn backup_cow_with_bounce_buffer(BackupBlockJob *job,
     if (!*bounce_buffer) {
         *bounce_buffer = blk_blockalign(blk, job->cluster_size);
     }
-    iov.iov_base = *bounce_buffer;
-    iov.iov_len = nbytes;
-    qemu_iovec_init_external(&qiov, &iov, 1);
+    qemu_iovec_init_buf(&qiov, *bounce_buffer, nbytes);
 
     ret = blk_co_preadv(blk, start, qiov.size, &qiov, read_flags);
     if (ret < 0) {
diff --git a/block/blkdebug.c b/block/blkdebug.c
index 0759452925..1ea835c2b9 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -811,51 +811,37 @@ static int64_t blkdebug_getlength(BlockDriverState *bs)
     return bdrv_getlength(bs->file->bs);
 }
 
-static void blkdebug_refresh_filename(BlockDriverState *bs, QDict *options)
+static void blkdebug_refresh_filename(BlockDriverState *bs)
 {
     BDRVBlkdebugState *s = bs->opaque;
-    QDict *opts;
     const QDictEntry *e;
-    bool force_json = false;
-
-    for (e = qdict_first(options); e; e = qdict_next(options, e)) {
-        if (strcmp(qdict_entry_key(e), "config") &&
-            strcmp(qdict_entry_key(e), "x-image"))
-        {
-            force_json = true;
-            break;
-        }
-    }
+    int ret;
 
-    if (force_json && !bs->file->bs->full_open_options) {
-        /* The config file cannot be recreated, so creating a plain filename
-         * is impossible */
+    if (!bs->file->bs->exact_filename[0]) {
         return;
     }
 
-    if (!force_json && bs->file->bs->exact_filename[0]) {
-        int ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
-                           "blkdebug:%s:%s", s->config_file ?: "",
-                           bs->file->bs->exact_filename);
-        if (ret >= sizeof(bs->exact_filename)) {
-            /* An overflow makes the filename unusable, so do not report any */
-            bs->exact_filename[0] = 0;
+    for (e = qdict_first(bs->full_open_options); e;
+         e = qdict_next(bs->full_open_options, e))
+    {
+        /* Real child options are under "image", but "x-image" may
+         * contain a filename */
+        if (strcmp(qdict_entry_key(e), "config") &&
+            strcmp(qdict_entry_key(e), "image") &&
+            strcmp(qdict_entry_key(e), "x-image") &&
+            strcmp(qdict_entry_key(e), "driver"))
+        {
+            return;
         }
     }
 
-    opts = qdict_new();
-    qdict_put_str(opts, "driver", "blkdebug");
-
-    qdict_put(opts, "image", qobject_ref(bs->file->bs->full_open_options));
-
-    for (e = qdict_first(options); e; e = qdict_next(options, e)) {
-        if (strcmp(qdict_entry_key(e), "x-image")) {
-            qdict_put_obj(opts, qdict_entry_key(e),
-                          qobject_ref(qdict_entry_value(e)));
-        }
+    ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
+                   "blkdebug:%s:%s",
+                   s->config_file ?: "", bs->file->bs->exact_filename);
+    if (ret >= sizeof(bs->exact_filename)) {
+        /* An overflow makes the filename unusable, so do not report any */
+        bs->exact_filename[0] = 0;
     }
-
-    bs->full_open_options = opts;
 }
 
 static void blkdebug_refresh_limits(BlockDriverState *bs, Error **errp)
@@ -888,6 +874,20 @@ static int blkdebug_reopen_prepare(BDRVReopenState *reopen_state,
     return 0;
 }
 
+static const char *const blkdebug_strong_runtime_opts[] = {
+    "config",
+    "inject-error.",
+    "set-state.",
+    "align",
+    "max-transfer",
+    "opt-write-zero",
+    "max-write-zero",
+    "opt-discard",
+    "max-discard",
+
+    NULL
+};
+
 static BlockDriver bdrv_blkdebug = {
     .format_name            = "blkdebug",
     .protocol_name          = "blkdebug",
@@ -917,6 +917,8 @@ static BlockDriver bdrv_blkdebug = {
                                 = blkdebug_debug_remove_breakpoint,
     .bdrv_debug_resume          = blkdebug_debug_resume,
     .bdrv_debug_is_suspended    = blkdebug_debug_is_suspended,
+
+    .strong_runtime_opts        = blkdebug_strong_runtime_opts,
 };
 
 static void bdrv_blkdebug_init(void)
diff --git a/block/blklogwrites.c b/block/blklogwrites.c
index d2e01bdb1d..eb2b4901a5 100644
--- a/block/blklogwrites.c
+++ b/block/blklogwrites.c
@@ -280,30 +280,6 @@ static int64_t blk_log_writes_getlength(BlockDriverState *bs)
     return bdrv_getlength(bs->file->bs);
 }
 
-static void blk_log_writes_refresh_filename(BlockDriverState *bs,
-                                            QDict *options)
-{
-    BDRVBlkLogWritesState *s = bs->opaque;
-
-    /* bs->file->bs has already been refreshed */
-    bdrv_refresh_filename(s->log_file->bs);
-
-    if (bs->file->bs->full_open_options
-        && s->log_file->bs->full_open_options)
-    {
-        QDict *opts = qdict_new();
-        qdict_put_str(opts, "driver", "blklogwrites");
-
-        qobject_ref(bs->file->bs->full_open_options);
-        qdict_put(opts, "file", bs->file->bs->full_open_options);
-        qobject_ref(s->log_file->bs->full_open_options);
-        qdict_put(opts, "log", s->log_file->bs->full_open_options);
-        qdict_put_int(opts, "log-sector-size", s->sectorsize);
-
-        bs->full_open_options = opts;
-    }
-}
-
 static void blk_log_writes_child_perm(BlockDriverState *bs, BdrvChild *c,
                                       const BdrvChildRole *role,
                                       BlockReopenQueue *ro_q,
@@ -520,6 +496,13 @@ blk_log_writes_co_pdiscard(BlockDriverState *bs, int64_t offset, int count)
                                  LOG_DISCARD_FLAG, false);
 }
 
+static const char *const blk_log_writes_strong_runtime_opts[] = {
+    "log-append",
+    "log-sector-size",
+
+    NULL
+};
+
 static BlockDriver bdrv_blk_log_writes = {
     .format_name            = "blklogwrites",
     .instance_size          = sizeof(BDRVBlkLogWritesState),
@@ -527,7 +510,6 @@ static BlockDriver bdrv_blk_log_writes = {
     .bdrv_open              = blk_log_writes_open,
     .bdrv_close             = blk_log_writes_close,
     .bdrv_getlength         = blk_log_writes_getlength,
-    .bdrv_refresh_filename  = blk_log_writes_refresh_filename,
     .bdrv_child_perm        = blk_log_writes_child_perm,
     .bdrv_refresh_limits    = blk_log_writes_refresh_limits,
 
@@ -539,6 +521,7 @@ static BlockDriver bdrv_blk_log_writes = {
     .bdrv_co_block_status   = bdrv_co_block_status_from_file,
 
     .is_filter              = true,
+    .strong_runtime_opts    = blk_log_writes_strong_runtime_opts,
 };
 
 static void bdrv_blk_log_writes_init(void)
diff --git a/block/blkverify.c b/block/blkverify.c
index 89bf4386e3..3ff77ff49a 100644
--- a/block/blkverify.c
+++ b/block/blkverify.c
@@ -281,27 +281,10 @@ static bool blkverify_recurse_is_first_non_filter(BlockDriverState *bs,
     return bdrv_recurse_is_first_non_filter(s->test_file->bs, candidate);
 }
 
-static void blkverify_refresh_filename(BlockDriverState *bs, QDict *options)
+static void blkverify_refresh_filename(BlockDriverState *bs)
 {
     BDRVBlkverifyState *s = bs->opaque;
 
-    /* bs->file->bs has already been refreshed */
-    bdrv_refresh_filename(s->test_file->bs);
-
-    if (bs->file->bs->full_open_options
-        && s->test_file->bs->full_open_options)
-    {
-        QDict *opts = qdict_new();
-        qdict_put_str(opts, "driver", "blkverify");
-
-        qdict_put(opts, "raw",
-                  qobject_ref(bs->file->bs->full_open_options));
-        qdict_put(opts, "test",
-                  qobject_ref(s->test_file->bs->full_open_options));
-
-        bs->full_open_options = opts;
-    }
-
     if (bs->file->bs->exact_filename[0]
         && s->test_file->bs->exact_filename[0])
     {
@@ -316,6 +299,15 @@ static void blkverify_refresh_filename(BlockDriverState *bs, QDict *options)
     }
 }
 
+static char *blkverify_dirname(BlockDriverState *bs, Error **errp)
+{
+    /* In general, there are two BDSs with different dirnames below this one;
+     * so there is no unique dirname we could return (unless both are equal by
+     * chance). Therefore, to be consistent, just always return NULL. */
+    error_setg(errp, "Cannot generate a base directory for blkverify nodes");
+    return NULL;
+}
+
 static BlockDriver bdrv_blkverify = {
     .format_name                      = "blkverify",
     .protocol_name                    = "blkverify",
@@ -327,6 +319,7 @@ static BlockDriver bdrv_blkverify = {
     .bdrv_child_perm                  = bdrv_filter_default_perms,
     .bdrv_getlength                   = blkverify_getlength,
     .bdrv_refresh_filename            = blkverify_refresh_filename,
+    .bdrv_dirname                     = blkverify_dirname,
 
     .bdrv_co_preadv                   = blkverify_co_preadv,
     .bdrv_co_pwritev                  = blkverify_co_pwritev,
diff --git a/block/block-backend.c b/block/block-backend.c
index f6ea824308..edad02a0f2 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1204,17 +1204,8 @@ static int blk_prw(BlockBackend *blk, int64_t offset, uint8_t *buf,
                    int64_t bytes, CoroutineEntry co_entry,
                    BdrvRequestFlags flags)
 {
-    QEMUIOVector qiov;
-    struct iovec iov;
-    BlkRwCo rwco;
-
-    iov = (struct iovec) {
-        .iov_base = buf,
-        .iov_len = bytes,
-    };
-    qemu_iovec_init_external(&qiov, &iov, 1);
-
-    rwco = (BlkRwCo) {
+    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
+    BlkRwCo rwco = {
         .blk    = blk,
         .offset = offset,
         .iobuf  = &qiov,
@@ -1262,12 +1253,12 @@ int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags)
     return bdrv_make_zero(blk->root, flags);
 }
 
-static void blk_inc_in_flight(BlockBackend *blk)
+void blk_inc_in_flight(BlockBackend *blk)
 {
     atomic_inc(&blk->in_flight);
 }
 
-static void blk_dec_in_flight(BlockBackend *blk)
+void blk_dec_in_flight(BlockBackend *blk)
 {
     atomic_dec(&blk->in_flight);
     aio_wait_kick();
diff --git a/block/commit.c b/block/commit.c
index 53148e610b..3b46ca7f97 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -47,14 +47,9 @@ static int coroutine_fn commit_populate(BlockBackend *bs, BlockBackend *base,
                                         void *buf)
 {
     int ret = 0;
-    QEMUIOVector qiov;
-    struct iovec iov = {
-        .iov_base = buf,
-        .iov_len = bytes,
-    };
+    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
 
     assert(bytes < SIZE_MAX);
-    qemu_iovec_init_external(&qiov, &iov, 1);
 
     ret = blk_co_preadv(bs, offset, qiov.size, &qiov, 0);
     if (ret < 0) {
@@ -230,9 +225,8 @@ static int coroutine_fn bdrv_commit_top_preadv(BlockDriverState *bs,
     return bdrv_co_preadv(bs->backing, offset, bytes, qiov, flags);
 }
 
-static void bdrv_commit_top_refresh_filename(BlockDriverState *bs, QDict *opts)
+static void bdrv_commit_top_refresh_filename(BlockDriverState *bs)
 {
-    bdrv_refresh_filename(bs->backing->bs);
     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename),
             bs->backing->bs->filename);
 }
@@ -374,10 +368,12 @@ fail:
     if (s->top) {
         blk_unref(s->top);
     }
+    job_early_fail(&s->common.job);
+    /* commit_top_bs has to be replaced after deleting the block job,
+     * otherwise this would fail because of lack of permissions. */
     if (commit_top_bs) {
         bdrv_replace_node(commit_top_bs, top, &error_abort);
     }
-    job_early_fail(&s->common.job);
 }
 
 
diff --git a/block/crypto.c b/block/crypto.c
index d5b1da66a1..fd8c7cfac6 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -619,6 +619,12 @@ block_crypto_get_specific_info_luks(BlockDriverState *bs, Error **errp)
     return spec_info;
 }
 
+static const char *const block_crypto_strong_runtime_opts[] = {
+    BLOCK_CRYPTO_OPT_LUKS_KEY_SECRET,
+
+    NULL
+};
+
 BlockDriver bdrv_crypto_luks = {
     .format_name        = "luks",
     .instance_size      = sizeof(BlockCrypto),
@@ -640,6 +646,8 @@ BlockDriver bdrv_crypto_luks = {
     .bdrv_getlength     = block_crypto_getlength,
     .bdrv_get_info      = block_crypto_get_info_luks,
     .bdrv_get_specific_info = block_crypto_get_specific_info_luks,
+
+    .strong_runtime_opts = block_crypto_strong_runtime_opts,
 };
 
 static void block_crypto_init(void)
diff --git a/block/curl.c b/block/curl.c
index b7ac265d3a..606709fea4 100644
--- a/block/curl.c
+++ b/block/curl.c
@@ -61,8 +61,6 @@ static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
 
 #define CURL_NUM_STATES 8
 #define CURL_NUM_ACB    8
-#define READ_AHEAD_DEFAULT (256 * 1024)
-#define CURL_TIMEOUT_DEFAULT 5
 #define CURL_TIMEOUT_MAX 10000
 
 #define CURL_BLOCK_OPT_URL       "url"
@@ -76,6 +74,10 @@ static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
 
+#define CURL_BLOCK_OPT_READAHEAD_DEFAULT (256 * 1024)
+#define CURL_BLOCK_OPT_SSLVERIFY_DEFAULT true
+#define CURL_BLOCK_OPT_TIMEOUT_DEFAULT 5
+
 struct BDRVCURLState;
 
 static bool libcurl_initialized;
@@ -696,7 +698,7 @@ static int curl_open(BlockDriverState *bs, QDict *options, int flags,
     }
 
     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
-                                          READ_AHEAD_DEFAULT);
+                                          CURL_BLOCK_OPT_READAHEAD_DEFAULT);
     if ((s->readahead_size & 0x1ff) != 0) {
         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
                    s->readahead_size);
@@ -704,13 +706,14 @@ static int curl_open(BlockDriverState *bs, QDict *options, int flags,
     }
 
     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
-                                     CURL_TIMEOUT_DEFAULT);
+                                     CURL_BLOCK_OPT_TIMEOUT_DEFAULT);
     if (s->timeout > CURL_TIMEOUT_MAX) {
         error_setg(errp, "timeout parameter is too large or negative");
         goto out_noclean;
     }
 
-    s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY, true);
+    s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY,
+                                     CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
 
     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
@@ -947,6 +950,36 @@ static int64_t curl_getlength(BlockDriverState *bs)
     return s->len;
 }
 
+static void curl_refresh_filename(BlockDriverState *bs)
+{
+    BDRVCURLState *s = bs->opaque;
+
+    /* "readahead" and "timeout" do not change the guest-visible data,
+     * so ignore them */
+    if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
+        s->cookie || s->username || s->password || s->proxyusername ||
+        s->proxypassword)
+    {
+        return;
+    }
+
+    pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
+}
+
+
+static const char *const curl_strong_runtime_opts[] = {
+    CURL_BLOCK_OPT_URL,
+    CURL_BLOCK_OPT_SSLVERIFY,
+    CURL_BLOCK_OPT_COOKIE,
+    CURL_BLOCK_OPT_COOKIE_SECRET,
+    CURL_BLOCK_OPT_USERNAME,
+    CURL_BLOCK_OPT_PASSWORD_SECRET,
+    CURL_BLOCK_OPT_PROXY_USERNAME,
+    CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
+
+    NULL
+};
+
 static BlockDriver bdrv_http = {
     .format_name                = "http",
     .protocol_name              = "http",
@@ -961,6 +994,9 @@ static BlockDriver bdrv_http = {
 
     .bdrv_detach_aio_context    = curl_detach_aio_context,
     .bdrv_attach_aio_context    = curl_attach_aio_context,
+
+    .bdrv_refresh_filename      = curl_refresh_filename,
+    .strong_runtime_opts        = curl_strong_runtime_opts,
 };
 
 static BlockDriver bdrv_https = {
@@ -977,6 +1013,9 @@ static BlockDriver bdrv_https = {
 
     .bdrv_detach_aio_context    = curl_detach_aio_context,
     .bdrv_attach_aio_context    = curl_attach_aio_context,
+
+    .bdrv_refresh_filename      = curl_refresh_filename,
+    .strong_runtime_opts        = curl_strong_runtime_opts,
 };
 
 static BlockDriver bdrv_ftp = {
@@ -993,6 +1032,9 @@ static BlockDriver bdrv_ftp = {
 
     .bdrv_detach_aio_context    = curl_detach_aio_context,
     .bdrv_attach_aio_context    = curl_attach_aio_context,
+
+    .bdrv_refresh_filename      = curl_refresh_filename,
+    .strong_runtime_opts        = curl_strong_runtime_opts,
 };
 
 static BlockDriver bdrv_ftps = {
@@ -1009,6 +1051,9 @@ static BlockDriver bdrv_ftps = {
 
     .bdrv_detach_aio_context    = curl_detach_aio_context,
     .bdrv_attach_aio_context    = curl_attach_aio_context,
+
+    .bdrv_refresh_filename      = curl_refresh_filename,
+    .strong_runtime_opts        = curl_strong_runtime_opts,
 };
 
 static void curl_block_init(void)
diff --git a/block/gluster.c b/block/gluster.c
index 72891060e3..af64330211 100644
--- a/block/gluster.c
+++ b/block/gluster.c
@@ -1495,6 +1495,21 @@ static int coroutine_fn qemu_gluster_co_block_status(BlockDriverState *bs,
 }
 
 
+static const char *const gluster_strong_open_opts[] = {
+    GLUSTER_OPT_VOLUME,
+    GLUSTER_OPT_PATH,
+    GLUSTER_OPT_TYPE,
+    GLUSTER_OPT_SERVER_PATTERN,
+    GLUSTER_OPT_HOST,
+    GLUSTER_OPT_PORT,
+    GLUSTER_OPT_TO,
+    GLUSTER_OPT_IPV4,
+    GLUSTER_OPT_IPV6,
+    GLUSTER_OPT_SOCKET,
+
+    NULL
+};
+
 static BlockDriver bdrv_gluster = {
     .format_name                  = "gluster",
     .protocol_name                = "gluster",
@@ -1522,6 +1537,7 @@ static BlockDriver bdrv_gluster = {
 #endif
     .bdrv_co_block_status         = qemu_gluster_co_block_status,
     .create_opts                  = &qemu_gluster_create_opts,
+    .strong_runtime_opts          = gluster_strong_open_opts,
 };
 
 static BlockDriver bdrv_gluster_tcp = {
@@ -1551,6 +1567,7 @@ static BlockDriver bdrv_gluster_tcp = {
 #endif
     .bdrv_co_block_status         = qemu_gluster_co_block_status,
     .create_opts                  = &qemu_gluster_create_opts,
+    .strong_runtime_opts          = gluster_strong_open_opts,
 };
 
 static BlockDriver bdrv_gluster_unix = {
@@ -1580,6 +1597,7 @@ static BlockDriver bdrv_gluster_unix = {
 #endif
     .bdrv_co_block_status         = qemu_gluster_co_block_status,
     .create_opts                  = &qemu_gluster_create_opts,
+    .strong_runtime_opts          = gluster_strong_open_opts,
 };
 
 /* rdma is deprecated (actually never supported for volfile fetch).
@@ -1615,6 +1633,7 @@ static BlockDriver bdrv_gluster_rdma = {
 #endif
     .bdrv_co_block_status         = qemu_gluster_co_block_status,
     .create_opts                  = &qemu_gluster_create_opts,
+    .strong_runtime_opts          = gluster_strong_open_opts,
 };
 
 static void bdrv_gluster_init(void)
diff --git a/block/io.c b/block/io.c
index 213ca03d8d..2ba603c7bc 100644
--- a/block/io.c
+++ b/block/io.c
@@ -843,17 +843,13 @@ static int bdrv_prwv_co(BdrvChild *child, int64_t offset,
 static int bdrv_rw_co(BdrvChild *child, int64_t sector_num, uint8_t *buf,
                       int nb_sectors, bool is_write, BdrvRequestFlags flags)
 {
-    QEMUIOVector qiov;
-    struct iovec iov = {
-        .iov_base = (void *)buf,
-        .iov_len = nb_sectors * BDRV_SECTOR_SIZE,
-    };
+    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf,
+                                            nb_sectors * BDRV_SECTOR_SIZE);
 
     if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
         return -EINVAL;
     }
 
-    qemu_iovec_init_external(&qiov, &iov, 1);
     return bdrv_prwv_co(child, sector_num << BDRV_SECTOR_BITS,
                         &qiov, is_write, flags);
 }
@@ -880,13 +876,8 @@ int bdrv_write(BdrvChild *child, int64_t sector_num,
 int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
                        int bytes, BdrvRequestFlags flags)
 {
-    QEMUIOVector qiov;
-    struct iovec iov = {
-        .iov_base = NULL,
-        .iov_len = bytes,
-    };
+    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, bytes);
 
-    qemu_iovec_init_external(&qiov, &iov, 1);
     return bdrv_prwv_co(child, offset, &qiov, true,
                         BDRV_REQ_ZERO_WRITE | flags);
 }
@@ -950,17 +941,12 @@ int bdrv_preadv(BdrvChild *child, int64_t offset, QEMUIOVector *qiov)
 
 int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int bytes)
 {
-    QEMUIOVector qiov;
-    struct iovec iov = {
-        .iov_base = (void *)buf,
-        .iov_len = bytes,
-    };
+    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
 
     if (bytes < 0) {
         return -EINVAL;
     }
 
-    qemu_iovec_init_external(&qiov, &iov, 1);
     return bdrv_preadv(child, offset, &qiov);
 }
 
@@ -978,17 +964,12 @@ int bdrv_pwritev(BdrvChild *child, int64_t offset, QEMUIOVector *qiov)
 
 int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, int bytes)
 {
-    QEMUIOVector qiov;
-    struct iovec iov = {
-        .iov_base   = (void *) buf,
-        .iov_len    = bytes,
-    };
+    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
 
     if (bytes < 0) {
         return -EINVAL;
     }
 
-    qemu_iovec_init_external(&qiov, &iov, 1);
     return bdrv_pwritev(child, offset, &qiov);
 }
 
@@ -1165,7 +1146,6 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
     void *bounce_buffer;
 
     BlockDriver *drv = bs->drv;
-    struct iovec iov;
     QEMUIOVector local_qiov;
     int64_t cluster_offset;
     int64_t cluster_bytes;
@@ -1230,9 +1210,8 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
 
         if (ret <= 0) {
             /* Must copy-on-read; use the bounce buffer */
-            iov.iov_base = bounce_buffer;
-            iov.iov_len = pnum = MIN(pnum, MAX_BOUNCE_BUFFER);
-            qemu_iovec_init_external(&local_qiov, &iov, 1);
+            pnum = MIN(pnum, MAX_BOUNCE_BUFFER);
+            qemu_iovec_init_buf(&local_qiov, bounce_buffer, pnum);
 
             ret = bdrv_driver_preadv(bs, cluster_offset, pnum,
                                      &local_qiov, 0);
@@ -1477,7 +1456,7 @@ static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs,
 {
     BlockDriver *drv = bs->drv;
     QEMUIOVector qiov;
-    struct iovec iov = {0};
+    void *buf = NULL;
     int ret = 0;
     bool need_flush = false;
     int head = 0;
@@ -1547,16 +1526,14 @@ static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs,
                 need_flush = true;
             }
             num = MIN(num, max_transfer);
-            iov.iov_len = num;
-            if (iov.iov_base == NULL) {
-                iov.iov_base = qemu_try_blockalign(bs, num);
-                if (iov.iov_base == NULL) {
+            if (buf == NULL) {
+                buf = qemu_try_blockalign0(bs, num);
+                if (buf == NULL) {
                     ret = -ENOMEM;
                     goto fail;
                 }
-                memset(iov.iov_base, 0, num);
             }
-            qemu_iovec_init_external(&qiov, &iov, 1);
+            qemu_iovec_init_buf(&qiov, buf, num);
 
             ret = bdrv_driver_pwritev(bs, offset, num, &qiov, write_flags);
 
@@ -1564,8 +1541,8 @@ static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs,
              * all future requests.
              */
             if (num < max_transfer) {
-                qemu_vfree(iov.iov_base);
-                iov.iov_base = NULL;
+                qemu_vfree(buf);
+                buf = NULL;
             }
         }
 
@@ -1577,7 +1554,7 @@ fail:
     if (ret == 0 && need_flush) {
         ret = bdrv_co_flush(bs);
     }
-    qemu_vfree(iov.iov_base);
+    qemu_vfree(buf);
     return ret;
 }
 
@@ -1763,7 +1740,6 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child,
     BlockDriverState *bs = child->bs;
     uint8_t *buf = NULL;
     QEMUIOVector local_qiov;
-    struct iovec iov;
     uint64_t align = bs->bl.request_alignment;
     unsigned int head_padding_bytes, tail_padding_bytes;
     int ret = 0;
@@ -1775,11 +1751,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child,
     assert(flags & BDRV_REQ_ZERO_WRITE);
     if (head_padding_bytes || tail_padding_bytes) {
         buf = qemu_blockalign(bs, align);
-        iov = (struct iovec) {
-            .iov_base   = buf,
-            .iov_len    = align,
-        };
-        qemu_iovec_init_external(&local_qiov, &iov, 1);
+        qemu_iovec_init_buf(&local_qiov, buf, align);
     }
     if (head_padding_bytes) {
         uint64_t zero_bytes = MIN(bytes, align - head_padding_bytes);
@@ -1885,17 +1857,12 @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
 
     if (offset & (align - 1)) {
         QEMUIOVector head_qiov;
-        struct iovec head_iov;
 
         mark_request_serialising(&req, align);
         wait_serialising_requests(&req);
 
         head_buf = qemu_blockalign(bs, align);
-        head_iov = (struct iovec) {
-            .iov_base   = head_buf,
-            .iov_len    = align,
-        };
-        qemu_iovec_init_external(&head_qiov, &head_iov, 1);
+        qemu_iovec_init_buf(&head_qiov, head_buf, align);
 
         bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD);
         ret = bdrv_aligned_preadv(child, &req, offset & ~(align - 1), align,
@@ -1924,7 +1891,6 @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
 
     if ((offset + bytes) & (align - 1)) {
         QEMUIOVector tail_qiov;
-        struct iovec tail_iov;
         size_t tail_bytes;
         bool waited;
 
@@ -1933,11 +1899,7 @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
         assert(!waited || !use_local_qiov);
 
         tail_buf = qemu_blockalign(bs, align);
-        tail_iov = (struct iovec) {
-            .iov_base   = tail_buf,
-            .iov_len    = align,
-        };
-        qemu_iovec_init_external(&tail_qiov, &tail_iov, 1);
+        qemu_iovec_init_buf(&tail_qiov, tail_buf, align);
 
         bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL);
         ret = bdrv_aligned_preadv(child, &req, (offset + bytes) & ~(align - 1),
@@ -2468,15 +2430,9 @@ bdrv_rw_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos,
 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
                       int64_t pos, int size)
 {
-    QEMUIOVector qiov;
-    struct iovec iov = {
-        .iov_base   = (void *) buf,
-        .iov_len    = size,
-    };
+    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, size);
     int ret;
 
-    qemu_iovec_init_external(&qiov, &iov, 1);
-
     ret = bdrv_writev_vmstate(bs, &qiov, pos);
     if (ret < 0) {
         return ret;
@@ -2493,14 +2449,9 @@ int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
                       int64_t pos, int size)
 {
-    QEMUIOVector qiov;
-    struct iovec iov = {
-        .iov_base   = buf,
-        .iov_len    = size,
-    };
+    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, size);
     int ret;
 
-    qemu_iovec_init_external(&qiov, &iov, 1);
     ret = bdrv_readv_vmstate(bs, &qiov, pos);
     if (ret < 0) {
         return ret;
diff --git a/block/iscsi.c b/block/iscsi.c
index ff473206e6..a0c0084837 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -2448,6 +2448,20 @@ static QemuOptsList iscsi_create_opts = {
     }
 };
 
+static const char *const iscsi_strong_runtime_opts[] = {
+    "transport",
+    "portal",
+    "target",
+    "user",
+    "password",
+    "password-secret",
+    "lun",
+    "initiator-name",
+    "header-digest",
+
+    NULL
+};
+
 static BlockDriver bdrv_iscsi = {
     .format_name     = "iscsi",
     .protocol_name   = "iscsi",
@@ -2482,6 +2496,8 @@ static BlockDriver bdrv_iscsi = {
 
     .bdrv_detach_aio_context = iscsi_detach_aio_context,
     .bdrv_attach_aio_context = iscsi_attach_aio_context,
+
+    .strong_runtime_opts = iscsi_strong_runtime_opts,
 };
 
 #if LIBISCSI_API_VERSION >= (20160603)
@@ -2519,6 +2535,8 @@ static BlockDriver bdrv_iser = {
 
     .bdrv_detach_aio_context = iscsi_detach_aio_context,
     .bdrv_attach_aio_context = iscsi_attach_aio_context,
+
+    .strong_runtime_opts = iscsi_strong_runtime_opts,
 };
 #endif
 
diff --git a/block/mirror.c b/block/mirror.c
index b67b0120f8..726d3c27fb 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1431,14 +1431,13 @@ static int coroutine_fn bdrv_mirror_top_pdiscard(BlockDriverState *bs,
                                     NULL, 0);
 }
 
-static void bdrv_mirror_top_refresh_filename(BlockDriverState *bs, QDict *opts)
+static void bdrv_mirror_top_refresh_filename(BlockDriverState *bs)
 {
     if (bs->backing == NULL) {
         /* we can be here after failed bdrv_attach_child in
          * bdrv_set_backing_hd */
         return;
     }
-    bdrv_refresh_filename(bs->backing->bs);
     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename),
             bs->backing->bs->filename);
 }
diff --git a/block/nbd-client.c b/block/nbd-client.c
index f0ad54ce21..bfbaf7ebe9 100644
--- a/block/nbd-client.c
+++ b/block/nbd-client.c
@@ -76,8 +76,18 @@ static coroutine_fn void nbd_connection_entry(void *opaque)
     Error *local_err = NULL;
 
     while (!s->quit) {
+        /*
+         * The NBD client can only really be considered idle when it has
+         * yielded from qio_channel_readv_all_eof(), waiting for data. This is
+         * the point where the additional scheduled coroutine entry happens
+         * after nbd_client_attach_aio_context().
+         *
+         * Therefore we keep an additional in_flight reference all the time and
+         * only drop it temporarily here.
+         */
         assert(s->reply.handle == 0);
-        ret = nbd_receive_reply(s->ioc, &s->reply, &local_err);
+        ret = nbd_receive_reply(s->bs, s->ioc, &s->reply, &local_err);
+
         if (local_err) {
             trace_nbd_read_reply_entry_fail(ret, error_get_pretty(local_err));
             error_free(local_err);
@@ -116,6 +126,8 @@ static coroutine_fn void nbd_connection_entry(void *opaque)
 
     s->quit = true;
     nbd_recv_coroutines_wake_all(s);
+    bdrv_dec_in_flight(s->bs);
+
     s->connection_co = NULL;
     aio_wait_kick();
 }
@@ -965,12 +977,30 @@ void nbd_client_detach_aio_context(BlockDriverState *bs)
     qio_channel_detach_aio_context(QIO_CHANNEL(client->ioc));
 }
 
+static void nbd_client_attach_aio_context_bh(void *opaque)
+{
+    BlockDriverState *bs = opaque;
+    NBDClientSession *client = nbd_get_client_session(bs);
+
+    /* The node is still drained, so we know the coroutine has yielded in
+     * nbd_read_eof(), the only place where bs->in_flight can reach 0, or it is
+     * entered for the first time. Both places are safe for entering the
+     * coroutine.*/
+    qemu_aio_coroutine_enter(bs->aio_context, client->connection_co);
+    bdrv_dec_in_flight(bs);
+}
+
 void nbd_client_attach_aio_context(BlockDriverState *bs,
                                    AioContext *new_context)
 {
     NBDClientSession *client = nbd_get_client_session(bs);
     qio_channel_attach_aio_context(QIO_CHANNEL(client->ioc), new_context);
-    aio_co_schedule(new_context, client->connection_co);
+
+    bdrv_inc_in_flight(bs);
+
+    /* Need to wait here for the BH to run because the BH must run while the
+     * node is still drained. */
+    aio_wait_bh_oneshot(new_context, nbd_client_attach_aio_context_bh, bs);
 }
 
 void nbd_client_close(BlockDriverState *bs)
@@ -1076,6 +1106,7 @@ static int nbd_client_connect(BlockDriverState *bs,
      * kick the reply mechanism.  */
     qio_channel_set_blocking(QIO_CHANNEL(sioc), false, NULL);
     client->connection_co = qemu_coroutine_create(nbd_connection_entry, client);
+    bdrv_inc_in_flight(bs);
     nbd_client_attach_aio_context(bs, bdrv_get_aio_context(bs));
 
     logout("Established connection with NBD server\n");
@@ -1108,6 +1139,7 @@ int nbd_client_init(BlockDriverState *bs,
 {
     NBDClientSession *client = nbd_get_client_session(bs);
 
+    client->bs = bs;
     qemu_co_mutex_init(&client->send_mutex);
     qemu_co_queue_init(&client->free_sema);
 
diff --git a/block/nbd-client.h b/block/nbd-client.h
index d990207a5c..09e03013d2 100644
--- a/block/nbd-client.h
+++ b/block/nbd-client.h
@@ -35,6 +35,7 @@ typedef struct NBDClientSession {
 
     NBDClientRequest requests[MAX_NBD_REQUESTS];
     NBDReply reply;
+    BlockDriverState *bs;
     bool quit;
 } NBDClientSession;
 
diff --git a/block/nbd.c b/block/nbd.c
index 9db5eded89..2e72df528a 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -477,12 +477,9 @@ static void nbd_attach_aio_context(BlockDriverState *bs,
     nbd_client_attach_aio_context(bs, new_context);
 }
 
-static void nbd_refresh_filename(BlockDriverState *bs, QDict *options)
+static void nbd_refresh_filename(BlockDriverState *bs)
 {
     BDRVNBDState *s = bs->opaque;
-    QDict *opts = qdict_new();
-    QObject *saddr_qdict;
-    Visitor *ov;
     const char *host = NULL, *port = NULL, *path = NULL;
 
     if (s->saddr->type == SOCKET_ADDRESS_TYPE_INET) {
@@ -495,8 +492,6 @@ static void nbd_refresh_filename(BlockDriverState *bs, QDict *options)
         path = s->saddr->u.q_unix.path;
     } /* else can't represent as pseudo-filename */
 
-    qdict_put_str(opts, "driver", "nbd");
-
     if (path && s->export) {
         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
                  "nbd+unix:///%s?socket=%s", s->export, path);
@@ -510,23 +505,28 @@ static void nbd_refresh_filename(BlockDriverState *bs, QDict *options)
         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
                  "nbd://%s:%s", host, port);
     }
+}
 
-    ov = qobject_output_visitor_new(&saddr_qdict);
-    visit_type_SocketAddress(ov, NULL, &s->saddr, &error_abort);
-    visit_complete(ov, &saddr_qdict);
-    visit_free(ov);
-    qdict_put_obj(opts, "server", saddr_qdict);
+static char *nbd_dirname(BlockDriverState *bs, Error **errp)
+{
+    /* The generic bdrv_dirname() implementation is able to work out some
+     * directory name for NBD nodes, but that would be wrong. So far there is no
+     * specification for how "export paths" would work, so NBD does not have
+     * directory names. */
+    error_setg(errp, "Cannot generate a base directory for NBD nodes");
+    return NULL;
+}
 
-    if (s->export) {
-        qdict_put_str(opts, "export", s->export);
-    }
-    if (s->tlscredsid) {
-        qdict_put_str(opts, "tls-creds", s->tlscredsid);
-    }
+static const char *const nbd_strong_runtime_opts[] = {
+    "path",
+    "host",
+    "port",
+    "export",
+    "tls-creds",
+    "server.",
 
-    qdict_flatten(opts);
-    bs->full_open_options = opts;
-}
+    NULL
+};
 
 static BlockDriver bdrv_nbd = {
     .format_name                = "nbd",
@@ -546,6 +546,8 @@ static BlockDriver bdrv_nbd = {
     .bdrv_attach_aio_context    = nbd_attach_aio_context,
     .bdrv_refresh_filename      = nbd_refresh_filename,
     .bdrv_co_block_status       = nbd_client_co_block_status,
+    .bdrv_dirname               = nbd_dirname,
+    .strong_runtime_opts        = nbd_strong_runtime_opts,
 };
 
 static BlockDriver bdrv_nbd_tcp = {
@@ -566,6 +568,8 @@ static BlockDriver bdrv_nbd_tcp = {
     .bdrv_attach_aio_context    = nbd_attach_aio_context,
     .bdrv_refresh_filename      = nbd_refresh_filename,
     .bdrv_co_block_status       = nbd_client_co_block_status,
+    .bdrv_dirname               = nbd_dirname,
+    .strong_runtime_opts        = nbd_strong_runtime_opts,
 };
 
 static BlockDriver bdrv_nbd_unix = {
@@ -586,6 +590,8 @@ static BlockDriver bdrv_nbd_unix = {
     .bdrv_attach_aio_context    = nbd_attach_aio_context,
     .bdrv_refresh_filename      = nbd_refresh_filename,
     .bdrv_co_block_status       = nbd_client_co_block_status,
+    .bdrv_dirname               = nbd_dirname,
+    .strong_runtime_opts        = nbd_strong_runtime_opts,
 };
 
 static void bdrv_nbd_init(void)
diff --git a/block/nfs.c b/block/nfs.c
index eab1a2c408..531903610b 100644
--- a/block/nfs.c
+++ b/block/nfs.c
@@ -799,14 +799,9 @@ static int nfs_reopen_prepare(BDRVReopenState *state,
     return 0;
 }
 
-static void nfs_refresh_filename(BlockDriverState *bs, QDict *options)
+static void nfs_refresh_filename(BlockDriverState *bs)
 {
     NFSClient *client = bs->opaque;
-    QDict *opts = qdict_new();
-    QObject *server_qdict;
-    Visitor *ov;
-
-    qdict_put_str(opts, "driver", "nfs");
 
     if (client->uid && !client->gid) {
         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
@@ -824,35 +819,20 @@ static void nfs_refresh_filename(BlockDriverState *bs, QDict *options)
         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
                  "nfs://%s%s", client->server->host, client->path);
     }
+}
 
-    ov = qobject_output_visitor_new(&server_qdict);
-    visit_type_NFSServer(ov, NULL, &client->server, &error_abort);
-    visit_complete(ov, &server_qdict);
-    qdict_put_obj(opts, "server", server_qdict);
-    qdict_put_str(opts, "path", client->path);
+static char *nfs_dirname(BlockDriverState *bs, Error **errp)
+{
+    NFSClient *client = bs->opaque;
 
-    if (client->uid) {
-        qdict_put_int(opts, "user", client->uid);
-    }
-    if (client->gid) {
-        qdict_put_int(opts, "group", client->gid);
-    }
-    if (client->tcp_syncnt) {
-        qdict_put_int(opts, "tcp-syn-cnt", client->tcp_syncnt);
-    }
-    if (client->readahead) {
-        qdict_put_int(opts, "readahead-size", client->readahead);
-    }
-    if (client->pagecache) {
-        qdict_put_int(opts, "page-cache-size", client->pagecache);
-    }
-    if (client->debug) {
-        qdict_put_int(opts, "debug", client->debug);
+    if (client->uid || client->gid) {
+        bdrv_refresh_filename(bs);
+        error_setg(errp, "Cannot generate a base directory for NFS node '%s'",
+                   bs->filename);
+        return NULL;
     }
 
-    visit_free(ov);
-    qdict_flatten(opts);
-    bs->full_open_options = opts;
+    return g_strdup_printf("nfs://%s%s/", client->server->host, client->path);
 }
 
 #ifdef LIBNFS_FEATURE_PAGECACHE
@@ -864,6 +844,15 @@ static void coroutine_fn nfs_co_invalidate_cache(BlockDriverState *bs,
 }
 #endif
 
+static const char *nfs_strong_runtime_opts[] = {
+    "path",
+    "user",
+    "group",
+    "server.",
+
+    NULL
+};
+
 static BlockDriver bdrv_nfs = {
     .format_name                    = "nfs",
     .protocol_name                  = "nfs",
@@ -889,6 +878,9 @@ static BlockDriver bdrv_nfs = {
     .bdrv_detach_aio_context        = nfs_detach_aio_context,
     .bdrv_attach_aio_context        = nfs_attach_aio_context,
     .bdrv_refresh_filename          = nfs_refresh_filename,
+    .bdrv_dirname                   = nfs_dirname,
+
+    .strong_runtime_opts            = nfs_strong_runtime_opts,
 
 #ifdef LIBNFS_FEATURE_PAGECACHE
     .bdrv_co_invalidate_cache       = nfs_co_invalidate_cache,
diff --git a/block/null.c b/block/null.c
index d442d3e901..a322929478 100644
--- a/block/null.c
+++ b/block/null.c
@@ -239,19 +239,33 @@ static int coroutine_fn null_co_block_status(BlockDriverState *bs,
     return ret;
 }
 
-static void null_refresh_filename(BlockDriverState *bs, QDict *opts)
+static void null_refresh_filename(BlockDriverState *bs)
 {
-    qdict_del(opts, "filename");
-
-    if (!qdict_size(opts)) {
-        snprintf(bs->exact_filename, sizeof(bs->exact_filename), "%s://",
-                 bs->drv->format_name);
+    const QDictEntry *e;
+
+    for (e = qdict_first(bs->full_open_options); e;
+         e = qdict_next(bs->full_open_options, e))
+    {
+        /* These options can be ignored */
+        if (strcmp(qdict_entry_key(e), "filename") &&
+            strcmp(qdict_entry_key(e), "driver") &&
+            strcmp(qdict_entry_key(e), NULL_OPT_LATENCY))
+        {
+            return;
+        }
     }
 
-    qdict_put_str(opts, "driver", bs->drv->format_name);
-    bs->full_open_options = qobject_ref(opts);
+    snprintf(bs->exact_filename, sizeof(bs->exact_filename), "%s://",
+             bs->drv->format_name);
 }
 
+static const char *const null_strong_runtime_opts[] = {
+    BLOCK_OPT_SIZE,
+    NULL_OPT_ZEROES,
+
+    NULL
+};
+
 static BlockDriver bdrv_null_co = {
     .format_name            = "null-co",
     .protocol_name          = "null-co",
@@ -269,6 +283,7 @@ static BlockDriver bdrv_null_co = {
     .bdrv_co_block_status   = null_co_block_status,
 
     .bdrv_refresh_filename  = null_refresh_filename,
+    .strong_runtime_opts    = null_strong_runtime_opts,
 };
 
 static BlockDriver bdrv_null_aio = {
@@ -288,6 +303,7 @@ static BlockDriver bdrv_null_aio = {
     .bdrv_co_block_status   = null_co_block_status,
 
     .bdrv_refresh_filename  = null_refresh_filename,
+    .strong_runtime_opts    = null_strong_runtime_opts,
 };
 
 static void bdrv_null_init(void)
diff --git a/block/nvme.c b/block/nvme.c
index b5952c9b08..0684bbd077 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -82,7 +82,7 @@ typedef volatile struct {
     uint8_t  reserved1[0xec0];
     uint8_t  cmd_set_specfic[0x100];
     uint32_t doorbells[];
-} QEMU_PACKED NVMeRegs;
+} NVMeRegs;
 
 QEMU_BUILD_BUG_ON(offsetof(NVMeRegs, doorbells) != 0x1000);
 
@@ -111,6 +111,9 @@ typedef struct {
 
     /* Total size of mapped qiov, accessed under dma_map_lock */
     int dma_map_count;
+
+    /* PCI address (required for nvme_refresh_filename()) */
+    char *device;
 } BDRVNVMeState;
 
 #define NVME_BLOCK_OPT_DEVICE "device"
@@ -557,6 +560,7 @@ static int nvme_init(BlockDriverState *bs, const char *device, int namespace,
 
     qemu_co_mutex_init(&s->dma_map_lock);
     qemu_co_queue_init(&s->dma_flush_queue);
+    s->device = g_strdup(device);
     s->nsid = namespace;
     s->aio_context = bdrv_get_aio_context(bs);
     ret = event_notifier_init(&s->irq_notifier, 0);
@@ -729,6 +733,8 @@ static void nvme_close(BlockDriverState *bs)
     event_notifier_cleanup(&s->irq_notifier);
     qemu_vfio_pci_unmap_bar(s->vfio, 0, (void *)s->regs, 0, NVME_BAR_SIZE);
     qemu_vfio_close(s->vfio);
+
+    g_free(s->device);
 }
 
 static int nvme_file_open(BlockDriverState *bs, QDict *options, int flags,
@@ -1053,17 +1059,12 @@ static int nvme_reopen_prepare(BDRVReopenState *reopen_state,
     return 0;
 }
 
-static void nvme_refresh_filename(BlockDriverState *bs, QDict *opts)
+static void nvme_refresh_filename(BlockDriverState *bs)
 {
-    qdict_del(opts, "filename");
-
-    if (!qdict_size(opts)) {
-        snprintf(bs->exact_filename, sizeof(bs->exact_filename), "%s://",
-                 bs->drv->format_name);
-    }
+    BDRVNVMeState *s = bs->opaque;
 
-    qdict_put_str(opts, "driver", bs->drv->format_name);
-    bs->full_open_options = qobject_ref(opts);
+    snprintf(bs->exact_filename, sizeof(bs->exact_filename), "nvme://%s/%i",
+             s->device, s->nsid);
 }
 
 static void nvme_refresh_limits(BlockDriverState *bs, Error **errp)
@@ -1136,6 +1137,13 @@ static void nvme_unregister_buf(BlockDriverState *bs, void *host)
     qemu_vfio_dma_unmap(s->vfio, host);
 }
 
+static const char *const nvme_strong_runtime_opts[] = {
+    NVME_BLOCK_OPT_DEVICE,
+    NVME_BLOCK_OPT_NAMESPACE,
+
+    NULL
+};
+
 static BlockDriver bdrv_nvme = {
     .format_name              = "nvme",
     .protocol_name            = "nvme",
@@ -1153,6 +1161,7 @@ static BlockDriver bdrv_nvme = {
 
     .bdrv_refresh_filename    = nvme_refresh_filename,
     .bdrv_refresh_limits      = nvme_refresh_limits,
+    .strong_runtime_opts      = nvme_strong_runtime_opts,
 
     .bdrv_detach_aio_context  = nvme_detach_aio_context,
     .bdrv_attach_aio_context  = nvme_attach_aio_context,
diff --git a/block/parallels.c b/block/parallels.c
index cc9445879d..15bc97b759 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -220,23 +220,20 @@ static int64_t allocate_clusters(BlockDriverState *bs, int64_t sector_num,
     if (bs->backing) {
         int64_t nb_cow_sectors = to_allocate * s->tracks;
         int64_t nb_cow_bytes = nb_cow_sectors << BDRV_SECTOR_BITS;
-        QEMUIOVector qiov;
-        struct iovec iov = {
-            .iov_len = nb_cow_bytes,
-            .iov_base = qemu_blockalign(bs, nb_cow_bytes)
-        };
-        qemu_iovec_init_external(&qiov, &iov, 1);
+        QEMUIOVector qiov =
+            QEMU_IOVEC_INIT_BUF(qiov, qemu_blockalign(bs, nb_cow_bytes),
+                                nb_cow_bytes);
 
         ret = bdrv_co_preadv(bs->backing, idx * s->tracks * BDRV_SECTOR_SIZE,
                              nb_cow_bytes, &qiov, 0);
         if (ret < 0) {
-            qemu_vfree(iov.iov_base);
+            qemu_vfree(qemu_iovec_buf(&qiov));
             return ret;
         }
 
         ret = bdrv_co_pwritev(bs->file, s->data_end * BDRV_SECTOR_SIZE,
                               nb_cow_bytes, &qiov, 0);
-        qemu_vfree(iov.iov_base);
+        qemu_vfree(qemu_iovec_buf(&qiov));
         if (ret < 0) {
             return ret;
         }
diff --git a/block/qapi.c b/block/qapi.c
index 00291f9105..6002a768f8 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -51,6 +51,8 @@ BlockDeviceInfo *bdrv_block_device_info(BlockBackend *blk,
         return NULL;
     }
 
+    bdrv_refresh_filename(bs);
+
     info = g_malloc0(sizeof(*info));
     info->file                   = g_strdup(bs->filename);
     info->ro                     = bs->read_only;
@@ -264,6 +266,8 @@ void bdrv_query_image_info(BlockDriverState *bs,
         goto out;
     }
 
+    bdrv_refresh_filename(bs);
+
     info = g_new0(ImageInfo, 1);
     info->filename        = g_strdup(bs->filename);
     info->format          = g_strdup(bdrv_get_format_name(bs));
@@ -292,18 +296,10 @@ void bdrv_query_image_info(BlockDriverState *bs,
 
     backing_filename = bs->backing_file;
     if (backing_filename[0] != '\0') {
-        char *backing_filename2 = g_malloc0(PATH_MAX);
+        char *backing_filename2;
         info->backing_filename = g_strdup(backing_filename);
         info->has_backing_filename = true;
-        bdrv_get_full_backing_filename(bs, backing_filename2, PATH_MAX, &err);
-        if (err) {
-            /* Can't reconstruct the full backing filename, so we must omit
-             * this field and apply a Best Effort to this query. */
-            g_free(backing_filename2);
-            backing_filename2 = NULL;
-            error_free(err);
-            err = NULL;
-        }
+        backing_filename2 = bdrv_get_full_backing_filename(bs, NULL);
 
         /* Always report the full_backing_filename if present, even if it's the
          * same as backing_filename. That they are same is useful info. */
diff --git a/block/qcow.c b/block/qcow.c
index 0a235bf393..10d2cf14b3 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -31,6 +31,7 @@
 #include "qemu/module.h"
 #include "qemu/option.h"
 #include "qemu/bswap.h"
+#include "qemu/cutils.h"
 #include <zlib.h>
 #include "qapi/qmp/qdict.h"
 #include "qapi/qmp/qstring.h"
@@ -295,11 +296,13 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags,
             goto fail;
         }
         ret = bdrv_pread(bs->file, header.backing_file_offset,
-                   bs->backing_file, len);
+                   bs->auto_backing_file, len);
         if (ret < 0) {
             goto fail;
         }
-        bs->backing_file[len] = '\0';
+        bs->auto_backing_file[len] = '\0';
+        pstrcpy(bs->backing_file, sizeof(bs->backing_file),
+                bs->auto_backing_file);
     }
 
     /* Disable migration when qcow images are used */
@@ -628,7 +631,6 @@ static coroutine_fn int qcow_co_preadv(BlockDriverState *bs, uint64_t offset,
     int offset_in_cluster;
     int ret = 0, n;
     uint64_t cluster_offset;
-    struct iovec hd_iov;
     QEMUIOVector hd_qiov;
     uint8_t *buf;
     void *orig_buf;
@@ -661,9 +663,7 @@ static coroutine_fn int qcow_co_preadv(BlockDriverState *bs, uint64_t offset,
         if (!cluster_offset) {
             if (bs->backing) {
                 /* read from the base image */
-                hd_iov.iov_base = (void *)buf;
-                hd_iov.iov_len = n;
-                qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
+                qemu_iovec_init_buf(&hd_qiov, buf, n);
                 qemu_co_mutex_unlock(&s->lock);
                 /* qcow2 emits this on bs->file instead of bs->backing */
                 BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
@@ -688,9 +688,7 @@ static coroutine_fn int qcow_co_preadv(BlockDriverState *bs, uint64_t offset,
                 ret = -EIO;
                 break;
             }
-            hd_iov.iov_base = (void *)buf;
-            hd_iov.iov_len = n;
-            qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
+            qemu_iovec_init_buf(&hd_qiov, buf, n);
             qemu_co_mutex_unlock(&s->lock);
             BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
             ret = bdrv_co_preadv(bs->file, cluster_offset + offset_in_cluster,
@@ -733,7 +731,6 @@ static coroutine_fn int qcow_co_pwritev(BlockDriverState *bs, uint64_t offset,
     int offset_in_cluster;
     uint64_t cluster_offset;
     int ret = 0, n;
-    struct iovec hd_iov;
     QEMUIOVector hd_qiov;
     uint8_t *buf;
     void *orig_buf;
@@ -779,9 +776,7 @@ static coroutine_fn int qcow_co_pwritev(BlockDriverState *bs, uint64_t offset,
             }
         }
 
-        hd_iov.iov_base = (void *)buf;
-        hd_iov.iov_len = n;
-        qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
+        qemu_iovec_init_buf(&hd_qiov, buf, n);
         qemu_co_mutex_unlock(&s->lock);
         BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
         ret = bdrv_co_pwritev(bs->file, cluster_offset + offset_in_cluster,
@@ -1062,7 +1057,6 @@ qcow_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
 {
     BDRVQcowState *s = bs->opaque;
     QEMUIOVector hd_qiov;
-    struct iovec iov;
     z_stream strm;
     int ret, out_len;
     uint8_t *buf, *out_buf;
@@ -1128,11 +1122,7 @@ qcow_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
     }
     cluster_offset &= s->cluster_offset_mask;
 
-    iov = (struct iovec) {
-        .iov_base   = out_buf,
-        .iov_len    = out_len,
-    };
-    qemu_iovec_init_external(&hd_qiov, &iov, 1);
+    qemu_iovec_init_buf(&hd_qiov, out_buf, out_len);
     BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED);
     ret = bdrv_co_pwritev(bs->file, cluster_offset, out_len, &hd_qiov, 0);
     if (ret < 0) {
@@ -1183,6 +1173,12 @@ static QemuOptsList qcow_create_opts = {
     }
 };
 
+static const char *const qcow_strong_runtime_opts[] = {
+    "encrypt." BLOCK_CRYPTO_OPT_QCOW_KEY_SECRET,
+
+    NULL
+};
+
 static BlockDriver bdrv_qcow = {
     .format_name	= "qcow",
     .instance_size	= sizeof(BDRVQcowState),
@@ -1206,6 +1202,7 @@ static BlockDriver bdrv_qcow = {
     .bdrv_get_info          = qcow_get_info,
 
     .create_opts            = &qcow_create_opts,
+    .strong_runtime_opts    = qcow_strong_runtime_opts,
 };
 
 static void bdrv_qcow_init(void)
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 30eca26c47..179aa2c728 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -285,6 +285,9 @@ static int l2_allocate(BlockDriverState *bs, int l1_index)
         goto fail;
     }
 
+    /* The offset must fit in the offset field of the L1 table entry */
+    assert((l2_offset & L1E_OFFSET_MASK) == l2_offset);
+
     /* If we're allocating the table at offset 0 then something is wrong */
     if (l2_offset == 0) {
         qcow2_signal_corruption(bs, true, -1, -1, "Preventing invalid "
diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index bb6a5b7516..20e8472191 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -358,11 +358,6 @@ int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info)
     /* Generate an ID */
     find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str));
 
-    /* Check that the ID is unique */
-    if (find_snapshot_by_id_and_name(bs, sn_info->id_str, NULL) >= 0) {
-        return -EEXIST;
-    }
-
     /* Populate sn with passed data */
     sn->id_str = g_strdup(sn_info->id_str);
     sn->name = g_strdup(sn_info->name);
diff --git a/block/qcow2.c b/block/qcow2.c
index 65a54c9ac6..7fb2730f09 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1474,13 +1474,15 @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options,
             goto fail;
         }
         ret = bdrv_pread(bs->file, header.backing_file_offset,
-                         bs->backing_file, len);
+                         bs->auto_backing_file, len);
         if (ret < 0) {
             error_setg_errno(errp, -ret, "Could not read backing file name");
             goto fail;
         }
-        bs->backing_file[len] = '\0';
-        s->image_backing_file = g_strdup(bs->backing_file);
+        bs->auto_backing_file[len] = '\0';
+        pstrcpy(bs->backing_file, sizeof(bs->backing_file),
+                bs->auto_backing_file);
+        s->image_backing_file = g_strdup(bs->auto_backing_file);
     }
 
     /* Internal snapshots */
@@ -2518,6 +2520,8 @@ static int qcow2_change_backing_file(BlockDriverState *bs,
         return -EINVAL;
     }
 
+    pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file),
+            backing_file ?: "");
     pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: "");
     pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: "");
 
@@ -3894,7 +3898,6 @@ qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
 {
     BDRVQcow2State *s = bs->opaque;
     QEMUIOVector hd_qiov;
-    struct iovec iov;
     int ret;
     size_t out_len;
     uint8_t *buf, *out_buf;
@@ -3960,11 +3963,7 @@ qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
         goto fail;
     }
 
-    iov = (struct iovec) {
-        .iov_base   = out_buf,
-        .iov_len    = out_len,
-    };
-    qemu_iovec_init_external(&hd_qiov, &iov, 1);
+    qemu_iovec_init_buf(&hd_qiov, out_buf, out_len);
 
     BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED);
     ret = bdrv_co_pwritev(bs->file, cluster_offset, out_len, &hd_qiov, 0);
@@ -3990,7 +3989,6 @@ qcow2_co_preadv_compressed(BlockDriverState *bs,
     int ret = 0, csize, nb_csectors;
     uint64_t coffset;
     uint8_t *buf, *out_buf;
-    struct iovec iov;
     QEMUIOVector local_qiov;
     int offset_in_cluster = offset_into_cluster(s, offset);
 
@@ -4002,9 +4000,7 @@ qcow2_co_preadv_compressed(BlockDriverState *bs,
     if (!buf) {
         return -ENOMEM;
     }
-    iov.iov_base = buf;
-    iov.iov_len = csize;
-    qemu_iovec_init_external(&local_qiov, &iov, 1);
+    qemu_iovec_init_buf(&local_qiov, buf, csize);
 
     out_buf = qemu_blockalign(bs, s->cluster_size);
 
@@ -4232,6 +4228,60 @@ static coroutine_fn int qcow2_co_flush_to_os(BlockDriverState *bs)
     return ret;
 }
 
+static ssize_t qcow2_measure_crypto_hdr_init_func(QCryptoBlock *block,
+        size_t headerlen, void *opaque, Error **errp)
+{
+    size_t *headerlenp = opaque;
+
+    /* Stash away the payload size */
+    *headerlenp = headerlen;
+    return 0;
+}
+
+static ssize_t qcow2_measure_crypto_hdr_write_func(QCryptoBlock *block,
+        size_t offset, const uint8_t *buf, size_t buflen,
+        void *opaque, Error **errp)
+{
+    /* Discard the bytes, we're not actually writing to an image */
+    return buflen;
+}
+
+/* Determine the number of bytes for the LUKS payload */
+static bool qcow2_measure_luks_headerlen(QemuOpts *opts, size_t *len,
+                                         Error **errp)
+{
+    QDict *opts_qdict;
+    QDict *cryptoopts_qdict;
+    QCryptoBlockCreateOptions *cryptoopts;
+    QCryptoBlock *crypto;
+
+    /* Extract "encrypt." options into a qdict */
+    opts_qdict = qemu_opts_to_qdict(opts, NULL);
+    qdict_extract_subqdict(opts_qdict, &cryptoopts_qdict, "encrypt.");
+    qobject_unref(opts_qdict);
+
+    /* Build QCryptoBlockCreateOptions object from qdict */
+    qdict_put_str(cryptoopts_qdict, "format", "luks");
+    cryptoopts = block_crypto_create_opts_init(cryptoopts_qdict, errp);
+    qobject_unref(cryptoopts_qdict);
+    if (!cryptoopts) {
+        return false;
+    }
+
+    /* Fake LUKS creation in order to determine the payload size */
+    crypto = qcrypto_block_create(cryptoopts, "encrypt.",
+                                  qcow2_measure_crypto_hdr_init_func,
+                                  qcow2_measure_crypto_hdr_write_func,
+                                  len, errp);
+    qapi_free_QCryptoBlockCreateOptions(cryptoopts);
+    if (!crypto) {
+        return false;
+    }
+
+    qcrypto_block_free(crypto);
+    return true;
+}
+
 static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
                                        Error **errp)
 {
@@ -4241,11 +4291,13 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
     uint64_t virtual_size; /* disk size as seen by guest */
     uint64_t refcount_bits;
     uint64_t l2_tables;
+    uint64_t luks_payload_size = 0;
     size_t cluster_size;
     int version;
     char *optstr;
     PreallocMode prealloc;
     bool has_backing_file;
+    bool has_luks;
 
     /* Parse image creation options */
     cluster_size = qcow2_opt_get_cluster_size_del(opts, &local_err);
@@ -4275,6 +4327,20 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
     has_backing_file = !!optstr;
     g_free(optstr);
 
+    optstr = qemu_opt_get_del(opts, BLOCK_OPT_ENCRYPT_FORMAT);
+    has_luks = optstr && strcmp(optstr, "luks") == 0;
+    g_free(optstr);
+
+    if (has_luks) {
+        size_t headerlen;
+
+        if (!qcow2_measure_luks_headerlen(opts, &headerlen, &local_err)) {
+            goto err;
+        }
+
+        luks_payload_size = ROUND_UP(headerlen, cluster_size);
+    }
+
     virtual_size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0);
     virtual_size = ROUND_UP(virtual_size, cluster_size);
 
@@ -4345,7 +4411,7 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
     info = g_new(BlockMeasureInfo, 1);
     info->fully_allocated =
         qcow2_calc_prealloc_size(virtual_size, cluster_size,
-                                 ctz32(refcount_bits));
+                                 ctz32(refcount_bits)) + luks_payload_size;
 
     /* Remove data clusters that are not required.  This overestimates the
      * required size because metadata needed for the fully allocated file is
@@ -4932,6 +4998,12 @@ static QemuOptsList qcow2_create_opts = {
     }
 };
 
+static const char *const qcow2_strong_runtime_opts[] = {
+    "encrypt." BLOCK_CRYPTO_OPT_QCOW_KEY_SECRET,
+
+    NULL
+};
+
 BlockDriver bdrv_qcow2 = {
     .format_name        = "qcow2",
     .instance_size      = sizeof(BDRVQcow2State),
@@ -4980,6 +5052,7 @@ BlockDriver bdrv_qcow2 = {
     .bdrv_inactivate            = qcow2_inactivate,
 
     .create_opts         = &qcow2_create_opts,
+    .strong_runtime_opts = qcow2_strong_runtime_opts,
     .bdrv_co_check       = qcow2_co_check,
     .bdrv_amend_options  = qcow2_amend_options,
 
diff --git a/block/qed-table.c b/block/qed-table.c
index 7df5680adb..c497bd4aec 100644
--- a/block/qed-table.c
+++ b/block/qed-table.c
@@ -21,16 +21,11 @@
 /* Called with table_lock held.  */
 static int qed_read_table(BDRVQEDState *s, uint64_t offset, QEDTable *table)
 {
-    QEMUIOVector qiov;
+    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(
+        qiov, table->offsets, s->header.cluster_size * s->header.table_size);
     int noffsets;
     int i, ret;
 
-    struct iovec iov = {
-        .iov_base = table->offsets,
-        .iov_len = s->header.cluster_size * s->header.table_size,
-    };
-    qemu_iovec_init_external(&qiov, &iov, 1);
-
     trace_qed_read_table(s, offset, table);
 
     qemu_co_mutex_unlock(&s->table_lock);
@@ -71,7 +66,6 @@ static int qed_write_table(BDRVQEDState *s, uint64_t offset, QEDTable *table,
     unsigned int sector_mask = BDRV_SECTOR_SIZE / sizeof(uint64_t) - 1;
     unsigned int start, end, i;
     QEDTable *new_table;
-    struct iovec iov;
     QEMUIOVector qiov;
     size_t len_bytes;
     int ret;
@@ -85,11 +79,7 @@ static int qed_write_table(BDRVQEDState *s, uint64_t offset, QEDTable *table,
     len_bytes = (end - start) * sizeof(uint64_t);
 
     new_table = qemu_blockalign(s->bs, len_bytes);
-    iov = (struct iovec) {
-        .iov_base = new_table->offsets,
-        .iov_len = len_bytes,
-    };
-    qemu_iovec_init_external(&qiov, &iov, 1);
+    qemu_iovec_init_buf(&qiov, new_table->offsets, len_bytes);
 
     /* Byteswap table */
     for (i = start; i < end; i++) {
diff --git a/block/qed.c b/block/qed.c
index 1280870024..89af05d524 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -113,18 +113,13 @@ static int coroutine_fn qed_write_header(BDRVQEDState *s)
     int nsectors = DIV_ROUND_UP(sizeof(QEDHeader), BDRV_SECTOR_SIZE);
     size_t len = nsectors * BDRV_SECTOR_SIZE;
     uint8_t *buf;
-    struct iovec iov;
     QEMUIOVector qiov;
     int ret;
 
     assert(s->allocating_acb || s->allocating_write_reqs_plugged);
 
     buf = qemu_blockalign(s->bs, len);
-    iov = (struct iovec) {
-        .iov_base = buf,
-        .iov_len = len,
-    };
-    qemu_iovec_init_external(&qiov, &iov, 1);
+    qemu_iovec_init_buf(&qiov, buf, len);
 
     ret = bdrv_co_preadv(s->bs->file, 0, qiov.size, &qiov, 0);
     if (ret < 0) {
@@ -454,11 +449,14 @@ static int coroutine_fn bdrv_qed_do_open(BlockDriverState *bs, QDict *options,
         }
 
         ret = qed_read_string(bs->file, s->header.backing_filename_offset,
-                              s->header.backing_filename_size, bs->backing_file,
-                              sizeof(bs->backing_file));
+                              s->header.backing_filename_size,
+                              bs->auto_backing_file,
+                              sizeof(bs->auto_backing_file));
         if (ret < 0) {
             return ret;
         }
+        pstrcpy(bs->backing_file, sizeof(bs->backing_file),
+                bs->auto_backing_file);
 
         if (s->header.features & QED_F_BACKING_FORMAT_NO_PROBE) {
             pstrcpy(bs->backing_format, sizeof(bs->backing_format), "raw");
@@ -913,7 +911,6 @@ static int coroutine_fn qed_copy_from_backing_file(BDRVQEDState *s,
 {
     QEMUIOVector qiov;
     QEMUIOVector *backing_qiov = NULL;
-    struct iovec iov;
     int ret;
 
     /* Skip copy entirely if there is no work to do */
@@ -921,11 +918,7 @@ static int coroutine_fn qed_copy_from_backing_file(BDRVQEDState *s,
         return 0;
     }
 
-    iov = (struct iovec) {
-        .iov_base = qemu_blockalign(s->bs, len),
-        .iov_len = len,
-    };
-    qemu_iovec_init_external(&qiov, &iov, 1);
+    qemu_iovec_init_buf(&qiov, qemu_blockalign(s->bs, len), len);
 
     ret = qed_read_backing_file(s, pos, &qiov, &backing_qiov);
 
@@ -946,7 +939,7 @@ static int coroutine_fn qed_copy_from_backing_file(BDRVQEDState *s,
     }
     ret = 0;
 out:
-    qemu_vfree(iov.iov_base);
+    qemu_vfree(qemu_iovec_buf(&qiov));
     return ret;
 }
 
@@ -1447,8 +1440,12 @@ static int coroutine_fn bdrv_qed_co_pwrite_zeroes(BlockDriverState *bs,
                                                   BdrvRequestFlags flags)
 {
     BDRVQEDState *s = bs->opaque;
-    QEMUIOVector qiov;
-    struct iovec iov;
+
+    /*
+     * Zero writes start without an I/O buffer.  If a buffer becomes necessary
+     * then it will be allocated during request processing.
+     */
+    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, bytes);
 
     /* Fall back if the request is not aligned */
     if (qed_offset_into_cluster(s, offset) ||
@@ -1456,13 +1453,6 @@ static int coroutine_fn bdrv_qed_co_pwrite_zeroes(BlockDriverState *bs,
         return -ENOTSUP;
     }
 
-    /* Zero writes start without an I/O buffer.  If a buffer becomes necessary
-     * then it will be allocated during request processing.
-     */
-    iov.iov_base = NULL;
-    iov.iov_len = bytes;
-
-    qemu_iovec_init_external(&qiov, &iov, 1);
     return qed_co_request(bs, offset >> BDRV_SECTOR_BITS, &qiov,
                           bytes >> BDRV_SECTOR_BITS,
                           QED_AIOCB_WRITE | QED_AIOCB_ZERO);
diff --git a/block/quorum.c b/block/quorum.c
index 16b3c8067c..352f729136 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -1065,36 +1065,64 @@ static void quorum_del_child(BlockDriverState *bs, BdrvChild *child,
     bdrv_drained_end(bs);
 }
 
-static void quorum_refresh_filename(BlockDriverState *bs, QDict *options)
+static void quorum_gather_child_options(BlockDriverState *bs, QDict *target,
+                                        bool backing_overridden)
 {
     BDRVQuorumState *s = bs->opaque;
-    QDict *opts;
-    QList *children;
+    QList *children_list;
     int i;
 
-    for (i = 0; i < s->num_children; i++) {
-        bdrv_refresh_filename(s->children[i]->bs);
-        if (!s->children[i]->bs->full_open_options) {
-            return;
-        }
-    }
+    /*
+     * The generic implementation for gathering child options in
+     * bdrv_refresh_filename() would use the names of the children
+     * as specified for bdrv_open_child() or bdrv_attach_child(),
+     * which is "children.%u" with %u being a value
+     * (s->next_child_index) that is incremented each time a new child
+     * is added (and never decremented).  Since children can be
+     * deleted at runtime, there may be gaps in that enumeration.
+     * When creating a new quorum BDS and specifying the children for
+     * it through runtime options, the enumeration used there may not
+     * have any gaps, though.
+     *
+     * Therefore, we have to create a new gap-less enumeration here
+     * (which we can achieve by simply putting all of the children's
+     * full_open_options into a QList).
+     *
+     * XXX: Note that there are issues with the current child option
+     *      structure quorum uses (such as the fact that children do
+     *      not really have unique permanent names).  Therefore, this
+     *      is going to have to change in the future and ideally we
+     *      want quorum to be covered by the generic implementation.
+     */
+
+    children_list = qlist_new();
+    qdict_put(target, "children", children_list);
 
-    children = qlist_new();
     for (i = 0; i < s->num_children; i++) {
-        qlist_append(children,
+        qlist_append(children_list,
                      qobject_ref(s->children[i]->bs->full_open_options));
     }
+}
 
-    opts = qdict_new();
-    qdict_put_str(opts, "driver", "quorum");
-    qdict_put_int(opts, QUORUM_OPT_VOTE_THRESHOLD, s->threshold);
-    qdict_put_bool(opts, QUORUM_OPT_BLKVERIFY, s->is_blkverify);
-    qdict_put_bool(opts, QUORUM_OPT_REWRITE, s->rewrite_corrupted);
-    qdict_put(opts, "children", children);
-
-    bs->full_open_options = opts;
+static char *quorum_dirname(BlockDriverState *bs, Error **errp)
+{
+    /* In general, there are multiple BDSs with different dirnames below this
+     * one; so there is no unique dirname we could return (unless all are equal
+     * by chance, or there is only one). Therefore, to be consistent, just
+     * always return NULL. */
+    error_setg(errp, "Cannot generate a base directory for quorum nodes");
+    return NULL;
 }
 
+static const char *const quorum_strong_runtime_opts[] = {
+    QUORUM_OPT_VOTE_THRESHOLD,
+    QUORUM_OPT_BLKVERIFY,
+    QUORUM_OPT_REWRITE,
+    QUORUM_OPT_READ_PATTERN,
+
+    NULL
+};
+
 static BlockDriver bdrv_quorum = {
     .format_name                        = "quorum",
 
@@ -1102,7 +1130,8 @@ static BlockDriver bdrv_quorum = {
 
     .bdrv_open                          = quorum_open,
     .bdrv_close                         = quorum_close,
-    .bdrv_refresh_filename              = quorum_refresh_filename,
+    .bdrv_gather_child_options          = quorum_gather_child_options,
+    .bdrv_dirname                       = quorum_dirname,
 
     .bdrv_co_flush_to_disk              = quorum_co_flush,
 
@@ -1118,6 +1147,8 @@ static BlockDriver bdrv_quorum = {
 
     .is_filter                          = true,
     .bdrv_recurse_is_first_non_filter   = quorum_recurse_is_first_non_filter,
+
+    .strong_runtime_opts                = quorum_strong_runtime_opts,
 };
 
 static void bdrv_quorum_init(void)
diff --git a/block/raw-format.c b/block/raw-format.c
index 6f6dc99b2c..e3e5ba2c8a 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -436,6 +436,7 @@ static int raw_open(BlockDriverState *bs, QDict *options, int flags,
             bs->file->bs->supported_zero_flags);
 
     if (bs->probed && !bdrv_is_read_only(bs)) {
+        bdrv_refresh_filename(bs->file->bs);
         fprintf(stderr,
                 "WARNING: Image format was not specified for '%s' and probing "
                 "guessed raw.\n"
@@ -531,6 +532,13 @@ static int coroutine_fn raw_co_copy_range_to(BlockDriverState *bs,
                                  read_flags, write_flags);
 }
 
+static const char *const raw_strong_runtime_opts[] = {
+    "offset",
+    "size",
+
+    NULL
+};
+
 BlockDriver bdrv_raw = {
     .format_name          = "raw",
     .instance_size        = sizeof(BDRVRawState),
@@ -560,7 +568,8 @@ BlockDriver bdrv_raw = {
     .bdrv_lock_medium     = &raw_lock_medium,
     .bdrv_co_ioctl        = &raw_co_ioctl,
     .create_opts          = &raw_create_opts,
-    .bdrv_has_zero_init   = &raw_has_zero_init
+    .bdrv_has_zero_init   = &raw_has_zero_init,
+    .strong_runtime_opts  = raw_strong_runtime_opts,
 };
 
 static void bdrv_raw_init(void)
diff --git a/block/rbd.c b/block/rbd.c
index 8a1a9f4b6e..0c549c9935 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -1228,6 +1228,18 @@ static QemuOptsList qemu_rbd_create_opts = {
     }
 };
 
+static const char *const qemu_rbd_strong_runtime_opts[] = {
+    "pool",
+    "image",
+    "conf",
+    "snapshot",
+    "user",
+    "server.",
+    "password-secret",
+
+    NULL
+};
+
 static BlockDriver bdrv_rbd = {
     .format_name            = "rbd",
     .instance_size          = sizeof(BDRVRBDState),
@@ -1265,6 +1277,8 @@ static BlockDriver bdrv_rbd = {
 #ifdef LIBRBD_SUPPORTS_INVALIDATE
     .bdrv_co_invalidate_cache = qemu_rbd_co_invalidate_cache,
 #endif
+
+    .strong_runtime_opts    = qemu_rbd_strong_runtime_opts,
 };
 
 static void bdrv_rbd_init(void)
diff --git a/block/replication.c b/block/replication.c
index e70dd95001..4c80b54daf 100644
--- a/block/replication.c
+++ b/block/replication.c
@@ -616,8 +616,6 @@ static void replication_done(void *opaque, int ret)
     if (ret == 0) {
         s->stage = BLOCK_REPLICATION_DONE;
 
-        /* refresh top bs's filename */
-        bdrv_refresh_filename(bs);
         s->active_disk = NULL;
         s->secondary_disk = NULL;
         s->hidden_disk = NULL;
@@ -678,6 +676,13 @@ static void replication_stop(ReplicationState *rs, bool failover, Error **errp)
     aio_context_release(aio_context);
 }
 
+static const char *const replication_strong_runtime_opts[] = {
+    REPLICATION_MODE,
+    REPLICATION_TOP_ID,
+
+    NULL
+};
+
 BlockDriver bdrv_replication = {
     .format_name                = "replication",
     .instance_size              = sizeof(BDRVReplicationState),
@@ -694,6 +699,7 @@ BlockDriver bdrv_replication = {
     .bdrv_recurse_is_first_non_filter = replication_recurse_is_first_non_filter,
 
     .has_variable_length        = true,
+    .strong_runtime_opts        = replication_strong_runtime_opts,
 };
 
 static void bdrv_replication_init(void)
diff --git a/block/sheepdog.c b/block/sheepdog.c
index b916ba07bf..cbdfe9ab6e 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -3203,6 +3203,15 @@ static QemuOptsList sd_create_opts = {
     }
 };
 
+static const char *const sd_strong_runtime_opts[] = {
+    "vdi",
+    "snap-id",
+    "tag",
+    "server.",
+
+    NULL
+};
+
 static BlockDriver bdrv_sheepdog = {
     .format_name                  = "sheepdog",
     .protocol_name                = "sheepdog",
@@ -3238,6 +3247,7 @@ static BlockDriver bdrv_sheepdog = {
     .bdrv_attach_aio_context      = sd_attach_aio_context,
 
     .create_opts                  = &sd_create_opts,
+    .strong_runtime_opts          = sd_strong_runtime_opts,
 };
 
 static BlockDriver bdrv_sheepdog_tcp = {
@@ -3275,6 +3285,7 @@ static BlockDriver bdrv_sheepdog_tcp = {
     .bdrv_attach_aio_context      = sd_attach_aio_context,
 
     .create_opts                  = &sd_create_opts,
+    .strong_runtime_opts          = sd_strong_runtime_opts,
 };
 
 static BlockDriver bdrv_sheepdog_unix = {
@@ -3312,6 +3323,7 @@ static BlockDriver bdrv_sheepdog_unix = {
     .bdrv_attach_aio_context      = sd_attach_aio_context,
 
     .create_opts                  = &sd_create_opts,
+    .strong_runtime_opts          = sd_strong_runtime_opts,
 };
 
 static void bdrv_sheepdog_init(void)
diff --git a/block/snapshot.c b/block/snapshot.c
index 3218a542df..f2f48f926a 100644
--- a/block/snapshot.c
+++ b/block/snapshot.c
@@ -63,7 +63,7 @@ int bdrv_snapshot_find(BlockDriverState *bs, QEMUSnapshotInfo *sn_info,
     }
     for (i = 0; i < nb_sns; i++) {
         sn = &sn_tab[i];
-        if (!strcmp(sn->id_str, name) || !strcmp(sn->name, name)) {
+        if (!strcmp(sn->name, name)) {
             *sn_info = *sn;
             ret = 0;
             break;
@@ -301,26 +301,6 @@ int bdrv_snapshot_delete(BlockDriverState *bs,
     return ret;
 }
 
-int bdrv_snapshot_delete_by_id_or_name(BlockDriverState *bs,
-                                       const char *id_or_name,
-                                       Error **errp)
-{
-    int ret;
-    Error *local_err = NULL;
-
-    ret = bdrv_snapshot_delete(bs, id_or_name, NULL, &local_err);
-    if (ret == -ENOENT || ret == -EINVAL) {
-        error_free(local_err);
-        local_err = NULL;
-        ret = bdrv_snapshot_delete(bs, NULL, id_or_name, &local_err);
-    }
-
-    if (ret < 0) {
-        error_propagate(errp, local_err);
-    }
-    return ret;
-}
-
 int bdrv_snapshot_list(BlockDriverState *bs,
                        QEMUSnapshotInfo **psn_info)
 {
@@ -448,7 +428,8 @@ int bdrv_all_delete_snapshot(const char *name, BlockDriverState **first_bad_bs,
         aio_context_acquire(ctx);
         if (bdrv_can_snapshot(bs) &&
                 bdrv_snapshot_find(bs, snapshot, name) >= 0) {
-            ret = bdrv_snapshot_delete_by_id_or_name(bs, name, err);
+            ret = bdrv_snapshot_delete(bs, snapshot->id_str,
+                                       snapshot->name, err);
         }
         aio_context_release(ctx);
         if (ret < 0) {
diff --git a/block/ssh.c b/block/ssh.c
index bbc513e095..190ef95300 100644
--- a/block/ssh.c
+++ b/block/ssh.c
@@ -1254,6 +1254,17 @@ static int coroutine_fn ssh_co_truncate(BlockDriverState *bs, int64_t offset,
     return ssh_grow_file(s, offset, errp);
 }
 
+static const char *const ssh_strong_runtime_opts[] = {
+    "host",
+    "port",
+    "path",
+    "user",
+    "host_key_check",
+    "server.",
+
+    NULL
+};
+
 static BlockDriver bdrv_ssh = {
     .format_name                  = "ssh",
     .protocol_name                = "ssh",
@@ -1270,6 +1281,7 @@ static BlockDriver bdrv_ssh = {
     .bdrv_co_truncate             = ssh_co_truncate,
     .bdrv_co_flush_to_disk        = ssh_co_flush,
     .create_opts                  = &ssh_create_opts,
+    .strong_runtime_opts          = ssh_strong_runtime_opts,
 };
 
 static void bdrv_ssh_init(void)
diff --git a/block/stream.c b/block/stream.c
index 7a49ac0992..e14579ff80 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -41,14 +41,9 @@ static int coroutine_fn stream_populate(BlockBackend *blk,
                                         int64_t offset, uint64_t bytes,
                                         void *buf)
 {
-    struct iovec iov = {
-        .iov_base = buf,
-        .iov_len  = bytes,
-    };
-    QEMUIOVector qiov;
+    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
 
     assert(bytes < SIZE_MAX);
-    qemu_iovec_init_external(&qiov, &iov, 1);
 
     /* Copy-on-read the unallocated clusters */
     return blk_co_preadv(blk, offset, qiov.size, &qiov, BDRV_REQ_COPY_ON_READ);
diff --git a/block/throttle.c b/block/throttle.c
index 636c9764aa..f64dcc27b9 100644
--- a/block/throttle.c
+++ b/block/throttle.c
@@ -227,6 +227,12 @@ static void coroutine_fn throttle_co_drain_end(BlockDriverState *bs)
     atomic_dec(&tgm->io_limits_disabled);
 }
 
+static const char *const throttle_strong_runtime_opts[] = {
+    QEMU_OPT_THROTTLE_GROUP_NAME,
+
+    NULL
+};
+
 static BlockDriver bdrv_throttle = {
     .format_name                        =   "throttle",
     .instance_size                      =   sizeof(ThrottleGroupMember),
@@ -259,6 +265,7 @@ static BlockDriver bdrv_throttle = {
     .bdrv_co_drain_end                  =   throttle_co_drain_end,
 
     .is_filter                          =   true,
+    .strong_runtime_opts                =   throttle_strong_runtime_opts,
 };
 
 static void bdrv_throttle_init(void)
diff --git a/block/vhdx-log.c b/block/vhdx-log.c
index ecd64266c5..3149ff08d8 100644
--- a/block/vhdx-log.c
+++ b/block/vhdx-log.c
@@ -803,6 +803,7 @@ int vhdx_parse_log(BlockDriverState *bs, BDRVVHDXState *s, bool *flushed,
 
     if (logs.valid) {
         if (bs->read_only) {
+            bdrv_refresh_filename(bs);
             ret = -EPERM;
             error_setg(errp,
                        "VHDX image file '%s' opened read-only, but "
diff --git a/block/vmdk.c b/block/vmdk.c
index 096e8eb662..d8c0c50390 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -27,6 +27,7 @@
 #include "qapi/error.h"
 #include "block/block_int.h"
 #include "sysemu/block-backend.h"
+#include "qapi/qmp/qdict.h"
 #include "qapi/qmp/qerror.h"
 #include "qemu/error-report.h"
 #include "qemu/module.h"
@@ -386,12 +387,14 @@ static int vmdk_parent_open(BlockDriverState *bs)
             ret = -EINVAL;
             goto out;
         }
-        if ((end_name - p_name) > sizeof(bs->backing_file) - 1) {
+        if ((end_name - p_name) > sizeof(bs->auto_backing_file) - 1) {
             ret = -EINVAL;
             goto out;
         }
 
-        pstrcpy(bs->backing_file, end_name - p_name + 1, p_name);
+        pstrcpy(bs->auto_backing_file, end_name - p_name + 1, p_name);
+        pstrcpy(bs->backing_file, sizeof(bs->backing_file),
+                bs->auto_backing_file);
     }
 
 out:
@@ -479,6 +482,7 @@ static int vmdk_init_tables(BlockDriverState *bs, VmdkExtent *extent,
                      extent->l1_table,
                      l1_size);
     if (ret < 0) {
+        bdrv_refresh_filename(extent->file->bs);
         error_setg_errno(errp, -ret,
                          "Could not read l1 table from extent '%s'",
                          extent->file->bs->filename);
@@ -499,6 +503,7 @@ static int vmdk_init_tables(BlockDriverState *bs, VmdkExtent *extent,
                          extent->l1_backup_table,
                          l1_size);
         if (ret < 0) {
+            bdrv_refresh_filename(extent->file->bs);
             error_setg_errno(errp, -ret,
                              "Could not read l1 backup table from extent '%s'",
                              extent->file->bs->filename);
@@ -530,6 +535,7 @@ static int vmdk_open_vmfs_sparse(BlockDriverState *bs,
 
     ret = bdrv_pread(file, sizeof(magic), &header, sizeof(header));
     if (ret < 0) {
+        bdrv_refresh_filename(file->bs);
         error_setg_errno(errp, -ret,
                          "Could not read header from file '%s'",
                          file->bs->filename);
@@ -607,6 +613,7 @@ static int vmdk_open_vmdk4(BlockDriverState *bs,
 
     ret = bdrv_pread(file, sizeof(magic), &header, sizeof(header));
     if (ret < 0) {
+        bdrv_refresh_filename(file->bs);
         error_setg_errno(errp, -ret,
                          "Could not read header from file '%s'",
                          file->bs->filename);
@@ -861,13 +868,13 @@ static int vmdk_parse_extents(const char *desc, BlockDriverState *bs,
         if (!path_is_absolute(fname) && !path_has_protocol(fname) &&
             !desc_file_path[0])
         {
+            bdrv_refresh_filename(bs->file->bs);
             error_setg(errp, "Cannot use relative extent paths with VMDK "
                        "descriptor file '%s'", bs->file->bs->filename);
             return -EINVAL;
         }
 
-        extent_path = g_malloc0(PATH_MAX);
-        path_combine(extent_path, PATH_MAX, desc_file_path, fname);
+        extent_path = path_combine(desc_file_path, fname);
 
         ret = snprintf(extent_opt_prefix, 32, "extents.%d", s->num_extents);
         assert(ret < 32);
@@ -1371,7 +1378,6 @@ static int vmdk_write_extent(VmdkExtent *extent, int64_t cluster_offset,
     VmdkGrainMarker *data = NULL;
     uLongf buf_len;
     QEMUIOVector local_qiov;
-    struct iovec iov;
     int64_t write_offset;
     int64_t write_end_sector;
 
@@ -1399,11 +1405,7 @@ static int vmdk_write_extent(VmdkExtent *extent, int64_t cluster_offset,
         data->size = cpu_to_le32(buf_len);
 
         n_bytes = buf_len + sizeof(VmdkGrainMarker);
-        iov = (struct iovec) {
-            .iov_base   = data,
-            .iov_len    = n_bytes,
-        };
-        qemu_iovec_init_external(&local_qiov, &iov, 1);
+        qemu_iovec_init_buf(&local_qiov, data, n_bytes);
 
         BLKDBG_EVENT(extent->file, BLKDBG_WRITE_COMPRESSED);
     } else {
@@ -2072,16 +2074,16 @@ static int coroutine_fn vmdk_co_do_create(int64_t size,
 
     if (backing_file) {
         BlockBackend *backing;
-        char *full_backing = g_new0(char, PATH_MAX);
-        bdrv_get_full_backing_filename_from_filename(blk_bs(blk)->filename, backing_file,
-                                                     full_backing, PATH_MAX,
-                                                     &local_err);
+        char *full_backing =
+            bdrv_get_full_backing_filename_from_filename(blk_bs(blk)->filename,
+                                                         backing_file,
+                                                         &local_err);
         if (local_err) {
-            g_free(full_backing);
             error_propagate(errp, local_err);
             ret = -ENOENT;
             goto exit;
         }
+        assert(full_backing);
 
         backing = blk_new_open(full_backing, NULL, NULL,
                                BDRV_O_NO_BACKING, errp);
@@ -2260,7 +2262,7 @@ static int coroutine_fn vmdk_co_create_opts(const char *filename, QemuOpts *opts
     compat6 = qemu_opt_get_bool_del(opts, BLOCK_OPT_COMPAT6, false);
     if (strcmp(hw_version, "undefined") == 0) {
         g_free(hw_version);
-        hw_version = g_strdup("4");
+        hw_version = NULL;
     }
     fmt = qemu_opt_get_del(opts, BLOCK_OPT_SUBFMT);
     zeroed_grain = qemu_opt_get_bool_del(opts, BLOCK_OPT_ZEROED_GRAIN, false);
@@ -2470,6 +2472,7 @@ static ImageInfo *vmdk_get_extent_info(VmdkExtent *extent)
 {
     ImageInfo *info = g_new0(ImageInfo, 1);
 
+    bdrv_refresh_filename(extent->file->bs);
     *info = (ImageInfo){
         .filename         = g_strdup(extent->file->bs->filename),
         .format           = g_strdup(extent->type),
@@ -2601,6 +2604,23 @@ static int vmdk_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
     return 0;
 }
 
+static void vmdk_gather_child_options(BlockDriverState *bs, QDict *target,
+                                      bool backing_overridden)
+{
+    /* No children but file and backing can be explicitly specified (TODO) */
+    qdict_put(target, "file",
+              qobject_ref(bs->file->bs->full_open_options));
+
+    if (backing_overridden) {
+        if (bs->backing) {
+            qdict_put(target, "backing",
+                      qobject_ref(bs->backing->bs->full_open_options));
+        } else {
+            qdict_put_null(target, "backing");
+        }
+    }
+}
+
 static QemuOptsList vmdk_create_opts = {
     .name = "vmdk-create-opts",
     .head = QTAILQ_HEAD_INITIALIZER(vmdk_create_opts.head),
@@ -2672,6 +2692,7 @@ static BlockDriver bdrv_vmdk = {
     .bdrv_get_specific_info       = vmdk_get_specific_info,
     .bdrv_refresh_limits          = vmdk_refresh_limits,
     .bdrv_get_info                = vmdk_get_info,
+    .bdrv_gather_child_options    = vmdk_gather_child_options,
 
     .supports_backing             = true,
     .create_opts                  = &vmdk_create_opts,
diff --git a/block/vpc.c b/block/vpc.c
index 52ab717642..a902a4c54d 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -1218,6 +1218,12 @@ static QemuOptsList vpc_create_opts = {
     }
 };
 
+static const char *const vpc_strong_runtime_opts[] = {
+    VPC_OPT_SIZE_CALC,
+
+    NULL
+};
+
 static BlockDriver bdrv_vpc = {
     .format_name    = "vpc",
     .instance_size  = sizeof(BDRVVPCState),
@@ -1238,6 +1244,7 @@ static BlockDriver bdrv_vpc = {
 
     .create_opts            = &vpc_create_opts,
     .bdrv_has_zero_init     = vpc_has_zero_init,
+    .strong_runtime_opts    = vpc_strong_runtime_opts,
 };
 
 static void bdrv_vpc_init(void)
diff --git a/block/vvfat.c b/block/vvfat.c
index b7b61ea8b7..5f66787890 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -3253,6 +3253,16 @@ static void vvfat_close(BlockDriverState *bs)
     }
 }
 
+static const char *const vvfat_strong_runtime_opts[] = {
+    "dir",
+    "fat-type",
+    "floppy",
+    "label",
+    "rw",
+
+    NULL
+};
+
 static BlockDriver bdrv_vvfat = {
     .format_name            = "vvfat",
     .protocol_name          = "fat",
@@ -3267,6 +3277,8 @@ static BlockDriver bdrv_vvfat = {
     .bdrv_co_preadv         = vvfat_co_preadv,
     .bdrv_co_pwritev        = vvfat_co_pwritev,
     .bdrv_co_block_status   = vvfat_co_block_status,
+
+    .strong_runtime_opts    = vvfat_strong_runtime_opts,
 };
 
 static void bdrv_vvfat_init(void)
diff --git a/block/vxhs.c b/block/vxhs.c
index 0cb0a007e9..2e18229ba4 100644
--- a/block/vxhs.c
+++ b/block/vxhs.c
@@ -556,6 +556,16 @@ static int64_t vxhs_getlength(BlockDriverState *bs)
     return vdisk_size;
 }
 
+static const char *const vxhs_strong_runtime_opts[] = {
+    VXHS_OPT_VDISK_ID,
+    "tls-creds",
+    VXHS_OPT_HOST,
+    VXHS_OPT_PORT,
+    VXHS_OPT_SERVER".",
+
+    NULL
+};
+
 static BlockDriver bdrv_vxhs = {
     .format_name                  = "vxhs",
     .protocol_name                = "vxhs",
@@ -567,6 +577,7 @@ static BlockDriver bdrv_vxhs = {
     .bdrv_getlength               = vxhs_getlength,
     .bdrv_aio_preadv              = vxhs_aio_preadv,
     .bdrv_aio_pwritev             = vxhs_aio_pwritev,
+    .strong_runtime_opts          = vxhs_strong_runtime_opts,
 };
 
 static void bdrv_vxhs_init(void)