block/export: Move writable to BlockExportOptions

The 'writable' option is a basic option that will probably be applicable
to most if not all export types that we will implement. Move it from NBD
to the generic BlockExport layer.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200924152717.287415-26-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Kevin Wolf 2020-09-24 17:27:11 +02:00
parent 8cade320c8
commit 30dbc81d31
5 changed files with 32 additions and 26 deletions

View File

@ -62,6 +62,7 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp)
BlockDriverState *bs;
BlockBackend *blk;
AioContext *ctx;
uint64_t perm;
int ret;
if (!id_wellformed(export->id)) {
@ -84,6 +85,14 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp)
return NULL;
}
if (!export->has_writable) {
export->writable = false;
}
if (bdrv_is_read_only(bs) && export->writable) {
error_setg(errp, "Cannot export read-only node as writable");
return NULL;
}
ctx = bdrv_get_aio_context(bs);
aio_context_acquire(ctx);
@ -95,7 +104,12 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp)
*/
bdrv_invalidate_cache(bs, NULL);
blk = blk_new(ctx, BLK_PERM_CONSISTENT_READ, BLK_PERM_ALL);
perm = BLK_PERM_CONSISTENT_READ;
if (export->writable) {
perm |= BLK_PERM_WRITE;
}
blk = blk_new(ctx, perm, BLK_PERM_ALL);
ret = blk_insert_bs(blk, bs, errp);
if (ret < 0) {
goto fail;

View File

@ -204,16 +204,8 @@ int nbd_export_create(BlockExport *exp, BlockExportOptions *exp_args,
return -EEXIST;
}
if (!arg->has_writable) {
arg->writable = false;
}
if (blk_is_read_only(exp->blk) && arg->writable) {
error_setg(errp, "Cannot export read-only node as writable");
return -EINVAL;
}
return nbd_export_new(exp, arg->name, arg->description, arg->bitmap,
!arg->writable, !arg->writable, errp);
!exp_args->writable, !exp_args->writable, errp);
}
void qmp_nbd_server_add(NbdServerAddOptions *arg, Error **errp)
@ -241,13 +233,13 @@ void qmp_nbd_server_add(NbdServerAddOptions *arg, Error **errp)
.type = BLOCK_EXPORT_TYPE_NBD,
.id = g_strdup(arg->name),
.node_name = g_strdup(bdrv_get_node_name(bs)),
.has_writable = arg->has_writable,
.writable = arg->writable,
.u.nbd = {
.has_name = true,
.name = g_strdup(arg->name),
.has_description = arg->has_description,
.description = g_strdup(arg->description),
.has_writable = arg->has_writable,
.writable = arg->writable,
.has_bitmap = arg->has_bitmap,
.bitmap = g_strdup(arg->bitmap),
},
@ -259,8 +251,8 @@ void qmp_nbd_server_add(NbdServerAddOptions *arg, Error **errp)
* block-export-add.
*/
if (bdrv_is_read_only(bs)) {
export_opts->u.nbd.has_writable = true;
export_opts->u.nbd.writable = false;
export_opts->has_writable = true;
export_opts->writable = false;
}
export = blk_exp_add(export_opts, errp);

View File

@ -1530,11 +1530,6 @@ int nbd_export_new(BlockExport *blk_exp,
/* Don't allow resize while the NBD server is running, otherwise we don't
* care what happens with the node. */
blk_get_perm(blk, &perm, &shared_perm);
if (!readonly) {
perm |= BLK_PERM_WRITE;
}
ret = blk_set_perm(blk, perm, shared_perm & ~BLK_PERM_RESIZE, errp);
if (ret < 0) {
return ret;

View File

@ -74,9 +74,6 @@
# @description: Free-form description of the export, up to 4096 bytes.
# (Since 5.0)
#
# @writable: Whether clients should be able to write to the device via the
# NBD connection (default false).
#
# @bitmap: Also export the dirty bitmap reachable from @device, so the
# NBD client can use NBD_OPT_SET_META_CONTEXT with
# "qemu:dirty-bitmap:NAME" to inspect the bitmap. (since 4.0)
@ -85,7 +82,7 @@
##
{ 'struct': 'BlockExportOptionsNbd',
'data': { '*name': 'str', '*description': 'str',
'*writable': 'bool', '*bitmap': 'str' } }
'*bitmap': 'str' } }
##
# @NbdServerAddOptions:
@ -94,11 +91,15 @@
#
# @device: The device name or node name of the node to be exported
#
# @writable: Whether clients should be able to write to the device via the
# NBD connection (default false).
#
# Since: 5.0
##
{ 'struct': 'NbdServerAddOptions',
'base': 'BlockExportOptionsNbd',
'data': { 'device': 'str' } }
'data': { 'device': 'str',
'*writable': 'bool' } }
##
# @nbd-server-add:
@ -188,6 +189,9 @@
#
# @node-name: The node name of the block node to be exported (since: 5.2)
#
# @writable: True if clients should be able to write to the export
# (default false)
#
# @writethrough: If true, caches are flushed after every write request to the
# export before completion is signalled. (since: 5.2;
# default: false)
@ -198,6 +202,7 @@
'base': { 'type': 'BlockExportType',
'id': 'str',
'node-name': 'str',
'*writable': 'bool',
'*writethrough': 'bool' },
'discriminator': 'type',
'data': {

View File

@ -1068,13 +1068,13 @@ int main(int argc, char **argv)
.node_name = g_strdup(bdrv_get_node_name(bs)),
.has_writethrough = true,
.writethrough = writethrough,
.has_writable = true,
.writable = !readonly,
.u.nbd = {
.has_name = true,
.name = g_strdup(export_name),
.has_description = !!export_description,
.description = g_strdup(export_description),
.has_writable = true,
.writable = !readonly,
.has_bitmap = !!bitmap,
.bitmap = g_strdup(bitmap),
},