block: reopen: Extract QemuOpts for generic block layer options

This patch adds a QemuOpts for generic block layer options to
bdrv_reopen_prepare(). The only two options that currently exist
(node-name and driver) cannot be changed, so the only thing we do is
putting them right back into the QDict so that we check at the end that
they are indeed unchanged.

We will add new options soon that can actually be changed.

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

1 files changed, 24 insertions, 0 deletions

diff --git a/block.c b/block.c
index a22c47cdb6..d0d9669b66 100644
--- a/block.c
+++ b/block.c
@@ -1907,11 +1907,34 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue,
     int ret = -1;
     Error *local_err = NULL;
     BlockDriver *drv;
+    QemuOpts *opts;
+    const char *value;
 
     assert(reopen_state != NULL);
     assert(reopen_state->bs->drv != NULL);
     drv = reopen_state->bs->drv;
 
+    /* Process generic block layer options */
+    opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort);
+    qemu_opts_absorb_qdict(opts, reopen_state->options, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        ret = -EINVAL;
+        goto error;
+    }
+
+    /* node-name and driver must be unchanged. Put them back into the QDict, so
+     * that they are checked at the end of this function. */
+    value = qemu_opt_get(opts, "node-name");
+    if (value) {
+        qdict_put(reopen_state->options, "node-name", qstring_from_str(value));
+    }
+
+    value = qemu_opt_get(opts, "driver");
+    if (value) {
+        qdict_put(reopen_state->options, "driver", qstring_from_str(value));
+    }
+
     /* if we are to stay read-only, do not allow permission change
      * to r/w */
     if (!(reopen_state->bs->open_flags & BDRV_O_ALLOW_RDWR) &&
@@ -1972,6 +1995,7 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue,
     ret = 0;
 
 error:
+    qemu_opts_del(opts);
     return ret;
 }