vduse-blk: Add serial option

Add a 'serial' option to allow user to specify this value
explicitly. And the default value is changed to an empty
string as what we did in "hw/block/virtio-blk.c".

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Message-Id: <20220614051532.92-6-xieyongji@bytedance.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block/export/vduse-blk.c

@@ -235,7 +235,7 @@ static int vduse_blk_exp_create(BlockExport *exp, BlockExportOptions *opts,
     Error *local_err = NULL;
     struct virtio_blk_config config = { 0 };
     uint64_t features;
-    int i;
+    int i, ret;
 
     if (vblk_opts->has_num_queues) {
         num_queues = vblk_opts->num_queues;
@@ -265,7 +265,8 @@ static int vduse_blk_exp_create(BlockExport *exp, BlockExportOptions *opts,
     }
     vblk_exp->num_queues = num_queues;
     vblk_exp->handler.blk = exp->blk;
-    vblk_exp->handler.serial = exp->id;
+    vblk_exp->handler.serial = g_strdup(vblk_opts->has_serial ?
+                                        vblk_opts->serial : "");
     vblk_exp->handler.logical_block_size = logical_block_size;
     vblk_exp->handler.writable = opts->writable;
 
@@ -306,16 +307,16 @@ static int vduse_blk_exp_create(BlockExport *exp, BlockExportOptions *opts,
                                      vblk_exp);
     if (!vblk_exp->dev) {
         error_setg(errp, "failed to create vduse device");
-        return -ENOMEM;
+        ret = -ENOMEM;
+        goto err_dev;
     }
 
     vblk_exp->recon_file = g_strdup_printf("%s/vduse-blk-%s",
                                            g_get_tmp_dir(), exp->id);
     if (vduse_set_reconnect_log_file(vblk_exp->dev, vblk_exp->recon_file)) {
         error_setg(errp, "failed to set reconnect log file");
-        vduse_dev_destroy(vblk_exp->dev);
-        g_free(vblk_exp->recon_file);
-        return -EINVAL;
+        ret = -EINVAL;
+        goto err;
     }
 
     for (i = 0; i < num_queues; i++) {
@@ -331,6 +332,12 @@ static int vduse_blk_exp_create(BlockExport *exp, BlockExportOptions *opts,
     blk_set_dev_ops(exp->blk, &vduse_block_ops, exp);
 
     return 0;
+err:
+    vduse_dev_destroy(vblk_exp->dev);
+    g_free(vblk_exp->recon_file);
+err_dev:
+    g_free(vblk_exp->handler.serial);
+    return ret;
 }
 
 static void vduse_blk_exp_delete(BlockExport *exp)
@@ -346,6 +353,7 @@ static void vduse_blk_exp_delete(BlockExport *exp)
         unlink(vblk_exp->recon_file);
     }
     g_free(vblk_exp->recon_file);
+    g_free(vblk_exp->handler.serial);
 }
 
 static void vduse_blk_exp_request_shutdown(BlockExport *exp)

block/export/vhost-user-blk-server.c

@@ -282,7 +282,7 @@ static int vu_blk_exp_create(BlockExport *exp, BlockExportOptions *opts,
         return -EINVAL;
     }
     vexp->handler.blk = exp->blk;
-    vexp->handler.serial = "vhost_user_blk";
+    vexp->handler.serial = g_strdup("vhost_user_blk");
     vexp->handler.logical_block_size = logical_block_size;
     vexp->handler.writable = opts->writable;
 
@@ -296,6 +296,7 @@ static int vu_blk_exp_create(BlockExport *exp, BlockExportOptions *opts,
                                  num_queues, &vu_blk_iface, errp)) {
         blk_remove_aio_context_notifier(exp->blk, blk_aio_attached,
                                         blk_aio_detach, vexp);
+        g_free(vexp->handler.serial);
         return -EADDRNOTAVAIL;
     }
 
@@ -308,6 +309,7 @@ static void vu_blk_exp_delete(BlockExport *exp)
 
     blk_remove_aio_context_notifier(exp->blk, blk_aio_attached, blk_aio_detach,
                                     vexp);
+    g_free(vexp->handler.serial);
 }
 
 const BlockExportDriver blk_exp_vhost_user_blk = {

block/export/virtio-blk-handler.h

@@ -23,7 +23,7 @@
 
 typedef struct {
     BlockBackend *blk;
-    const char *serial;
+    char *serial;
     uint32_t logical_block_size;
     bool writable;
 } VirtioBlkHandler;

docs/tools/qemu-storage-daemon.rst

@@ -77,7 +77,7 @@ Standard options:
   --export [type=]vhost-user-blk,id=<id>,node-name=<node-name>,addr.type=unix,addr.path=<socket-path>[,writable=on|off][,logical-block-size=<block-size>][,num-queues=<num-queues>]
   --export [type=]vhost-user-blk,id=<id>,node-name=<node-name>,addr.type=fd,addr.str=<fd>[,writable=on|off][,logical-block-size=<block-size>][,num-queues=<num-queues>]
   --export [type=]fuse,id=<id>,node-name=<node-name>,mountpoint=<file>[,growable=on|off][,writable=on|off][,allow-other=on|off|auto]
-  --export [type=]vduse-blk,id=<id>,node-name=<node-name>[,writable=on|off][,num-queues=<num-queues>][,queue-size=<queue-size>][,logical-block-size=<block-size>]
+  --export [type=]vduse-blk,id=<id>,node-name=<node-name>[,writable=on|off][,num-queues=<num-queues>][,queue-size=<queue-size>][,logical-block-size=<block-size>][,serial=<serial-number>]
 
   is a block export definition. ``node-name`` is the block node that should be
   exported. ``writable`` determines whether or not the export allows write

qapi/block-export.json

@@ -187,13 +187,15 @@
 # @queue-size: the size of virtqueue. Defaults to 256.
 # @logical-block-size: Logical block size in bytes. Range [512, PAGE_SIZE]
 #                      and must be power of 2. Defaults to 512 bytes.
+# @serial: the serial number of virtio block device. Defaults to empty string.
 #
 # Since: 7.1
 ##
 { 'struct': 'BlockExportOptionsVduseBlk',
   'data': { '*num-queues': 'uint16',
             '*queue-size': 'uint16',
-            '*logical-block-size': 'size'} }
+            '*logical-block-size': 'size',
+            '*serial': 'str' } }
 
 ##
 # @NbdServerAddOptions:

storage-daemon/qemu-storage-daemon.c

@@ -126,6 +126,7 @@ static void help(void)
 "           [,writable=on|off][,num-queues=<num-queues>]\n"
 "           [,queue-size=<queue-size>]\n"
 "           [,logical-block-size=<logical-block-size>]\n"
+"           [,serial=<serial-number>]\n"
 "                         export the specified block node as a vduse-blk\n"
 "                         device using the id as the VDUSE device name\n"
 "\n"