block: introduce BlockDriver.bdrv_needs_filename to enable some drivers.

Some drivers will have driver specifics options but no filename.
This new bool allow the block layer to treat them correctly.

The .bdrv_needs_filename is set in drivers not having .bdrv_parse_filename and
not having .bdrv_open.

The first exception to this rule will be the quorum driver.

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block.c

@@ -792,7 +792,7 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
     /* Open the image, either directly or using a protocol */
     if (drv->bdrv_file_open) {
         assert(file == NULL);
-        assert(drv->bdrv_parse_filename || filename != NULL);
+        assert(!drv->bdrv_needs_filename || filename != NULL);
         ret = drv->bdrv_file_open(bs, options, open_flags, &local_err);
     } else {
         if (file == NULL) {
@@ -911,7 +911,7 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename,
             goto fail;
         }
         qdict_del(options, "filename");
-    } else if (!drv->bdrv_parse_filename && !filename) {
+    } else if (drv->bdrv_needs_filename && !filename) {
         error_setg(errp, "The '%s' block driver requires a file name",
                    drv->format_name);
         ret = -EINVAL;

block/gluster.c

@@ -611,6 +611,7 @@ static BlockDriver bdrv_gluster = {
     .format_name                  = "gluster",
     .protocol_name                = "gluster",
     .instance_size                = sizeof(BDRVGlusterState),
+    .bdrv_needs_filename          = true,
     .bdrv_file_open               = qemu_gluster_open,
     .bdrv_close                   = qemu_gluster_close,
     .bdrv_create                  = qemu_gluster_create,
@@ -631,6 +632,7 @@ static BlockDriver bdrv_gluster_tcp = {
     .format_name                  = "gluster",
     .protocol_name                = "gluster+tcp",
     .instance_size                = sizeof(BDRVGlusterState),
+    .bdrv_needs_filename          = true,
     .bdrv_file_open               = qemu_gluster_open,
     .bdrv_close                   = qemu_gluster_close,
     .bdrv_create                  = qemu_gluster_create,
@@ -651,6 +653,7 @@ static BlockDriver bdrv_gluster_unix = {
     .format_name                  = "gluster",
     .protocol_name                = "gluster+unix",
     .instance_size                = sizeof(BDRVGlusterState),
+    .bdrv_needs_filename          = true,
     .bdrv_file_open               = qemu_gluster_open,
     .bdrv_close                   = qemu_gluster_close,
     .bdrv_create                  = qemu_gluster_create,
@@ -671,6 +674,7 @@ static BlockDriver bdrv_gluster_rdma = {
     .format_name                  = "gluster",
     .protocol_name                = "gluster+rdma",
     .instance_size                = sizeof(BDRVGlusterState),
+    .bdrv_needs_filename          = true,
     .bdrv_file_open               = qemu_gluster_open,
     .bdrv_close                   = qemu_gluster_close,
     .bdrv_create                  = qemu_gluster_create,

block/iscsi.c

@@ -1520,6 +1520,7 @@ static BlockDriver bdrv_iscsi = {
     .protocol_name   = "iscsi",
 
     .instance_size   = sizeof(IscsiLun),
+    .bdrv_needs_filename = true,
     .bdrv_file_open  = iscsi_open,
     .bdrv_close      = iscsi_close,
     .bdrv_create     = iscsi_create,

block/raw-posix.c

@@ -1200,6 +1200,7 @@ static BlockDriver bdrv_file = {
     .format_name = "file",
     .protocol_name = "file",
     .instance_size = sizeof(BDRVRawState),
+    .bdrv_needs_filename = true,
     .bdrv_probe = NULL, /* no probe for protocols */
     .bdrv_file_open = raw_open,
     .bdrv_reopen_prepare = raw_reopen_prepare,
@@ -1542,6 +1543,7 @@ static BlockDriver bdrv_host_device = {
     .format_name        = "host_device",
     .protocol_name        = "host_device",
     .instance_size      = sizeof(BDRVRawState),
+    .bdrv_needs_filename = true,
     .bdrv_probe_device  = hdev_probe_device,
     .bdrv_file_open     = hdev_open,
     .bdrv_close         = raw_close,
@@ -1667,6 +1669,7 @@ static BlockDriver bdrv_host_floppy = {
     .format_name        = "host_floppy",
     .protocol_name      = "host_floppy",
     .instance_size      = sizeof(BDRVRawState),
+    .bdrv_needs_filename = true,
     .bdrv_probe_device	= floppy_probe_device,
     .bdrv_file_open     = floppy_open,
     .bdrv_close         = raw_close,
@@ -1769,6 +1772,7 @@ static BlockDriver bdrv_host_cdrom = {
     .format_name        = "host_cdrom",
     .protocol_name      = "host_cdrom",
     .instance_size      = sizeof(BDRVRawState),
+    .bdrv_needs_filename = true,
     .bdrv_probe_device	= cdrom_probe_device,
     .bdrv_file_open     = cdrom_open,
     .bdrv_close         = raw_close,
@@ -1890,6 +1894,7 @@ static BlockDriver bdrv_host_cdrom = {
     .format_name        = "host_cdrom",
     .protocol_name      = "host_cdrom",
     .instance_size      = sizeof(BDRVRawState),
+    .bdrv_needs_filename = true,
     .bdrv_probe_device	= cdrom_probe_device,
     .bdrv_file_open     = cdrom_open,
     .bdrv_close         = raw_close,

block/raw-win32.c

@@ -459,6 +459,7 @@ static BlockDriver bdrv_file = {
     .format_name	= "file",
     .protocol_name	= "file",
     .instance_size	= sizeof(BDRVRawState),
+    .bdrv_needs_filename = true,
     .bdrv_file_open	= raw_open,
     .bdrv_close		= raw_close,
     .bdrv_create	= raw_create,
@@ -601,6 +602,7 @@ static BlockDriver bdrv_host_device = {
     .format_name	= "host_device",
     .protocol_name	= "host_device",
     .instance_size	= sizeof(BDRVRawState),
+    .bdrv_needs_filename = true,
     .bdrv_probe_device	= hdev_probe_device,
     .bdrv_file_open	= hdev_open,
     .bdrv_close		= raw_close,

block/rbd.c

@@ -1002,6 +1002,7 @@ static QEMUOptionParameter qemu_rbd_create_options[] = {
 static BlockDriver bdrv_rbd = {
     .format_name        = "rbd",
     .instance_size      = sizeof(BDRVRBDState),
+    .bdrv_needs_filename = true,
     .bdrv_file_open     = qemu_rbd_open,
     .bdrv_close         = qemu_rbd_close,
     .bdrv_create        = qemu_rbd_create,

block/sheepdog.c

@@ -2338,6 +2338,7 @@ static BlockDriver bdrv_sheepdog = {
     .format_name    = "sheepdog",
     .protocol_name  = "sheepdog",
     .instance_size  = sizeof(BDRVSheepdogState),
+    .bdrv_needs_filename = true,
     .bdrv_file_open = sd_open,
     .bdrv_close     = sd_close,
     .bdrv_create    = sd_create,
@@ -2366,6 +2367,7 @@ static BlockDriver bdrv_sheepdog_tcp = {
     .format_name    = "sheepdog",
     .protocol_name  = "sheepdog+tcp",
     .instance_size  = sizeof(BDRVSheepdogState),
+    .bdrv_needs_filename = true,
     .bdrv_file_open = sd_open,
     .bdrv_close     = sd_close,
     .bdrv_create    = sd_create,
@@ -2394,6 +2396,7 @@ static BlockDriver bdrv_sheepdog_unix = {
     .format_name    = "sheepdog",
     .protocol_name  = "sheepdog+unix",
     .instance_size  = sizeof(BDRVSheepdogState),
+    .bdrv_needs_filename = true,
     .bdrv_file_open = sd_open,
     .bdrv_close     = sd_close,
     .bdrv_create    = sd_create,

include/block/block_int.h

@@ -73,6 +73,12 @@ struct BlockDriver {
     /* Any driver implementing this callback is expected to be able to handle
      * NULL file names in its .bdrv_open() implementation */
     void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp);
+    /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
+     * this field set to true, except ones that are defined only by their
+     * child's bs.
+     * An example of the last type will be the quorum block driver.
+     */
+    bool bdrv_needs_filename;
 
     /* For handling image reopen for split or non-split files */
     int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,