Since 'nbd-server-add' is deprecated, and 'block-export-add' is new to 5.2, we can still tweak the interface. Allowing 'bitmaps':['str'] is nicer than 'bitmap':'str'. This wires up the qapi and qemu-nbd changes to permit passing multiple bitmaps as distinct metadata contexts that the NBD client may request, but the actual support for more than one will require a further patch to the server. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov(a)virtuozzo.com&gt; --- docs/system/deprecated.rst | 4 +++- qapi/block-export.json | 18 ++++++++++++------ blockdev-nbd.c | 13 +++++++++++++ nbd/server.c | 19 +++++++++++++------ qemu-nbd.c | 10 +++++----- 5 files changed, 46 insertions(+), 18 deletions(-) diff --git a/docs/system/deprecated.rst b/docs/system/deprecated.rst index 905628f3a0cb..d6cd027ac740 100644 --- a/docs/system/deprecated.rst +++ b/docs/system/deprecated.rst @@ -268,7 +268,9 @@ the 'wait' field, which is only applicable to sockets in server mode '''''''''''''''''''''''''''''''''''''''''''''''''''''''' Use the more generic commands ``block-export-add`` and ``block-export-del`` -instead. +instead. As part of this deprecation, it is now preferred to export a +list of dirty bitmaps via ``bitmaps``, rather than a single bitmap via +``bitmap``. Human Monitor Protocol (HMP) commands ------------------------------------- diff --git a/qapi/block-export.json b/qapi/block-export.json index 893d5cde5dfe..c7c749d61097 100644 --- a/qapi/block-export.json +++ b/qapi/block-export.json @@ -74,10 +74,10 @@ # @description: Free-form description of the export, up to 4096 bytes. # (Since 5.0) # -# @bitmap: Also export the dirty bitmap reachable from @device, so the -# NBD client can use NBD_OPT_SET_META_CONTEXT with the -# metadata context name "qemu:dirty-bitmap:NAME" to inspect the -# bitmap. (since 4.0) +# @bitmaps: Also export each of the named dirty bitmaps reachable from +# @device, so the NBD client can use NBD_OPT_SET_META_CONTEXT with +# the metadata context name "qemu:dirty-bitmap:BITMAP" to inspect +# each bitmap. (since 5.2) # # @allocation-depth: Also export the allocation depth map for @device, so # the NBD client can use NBD_OPT_SET_META_CONTEXT with @@ -88,7 +88,7 @@ ## { 'struct': 'BlockExportOptionsNbd', 'data': { '*name': 'str', '*description': 'str', - '*bitmap': 'str', '*allocation-depth': 'bool' } } + '*bitmaps': ['str'], '*allocation-depth': 'bool' } } ## # @NbdServerAddOptions: @@ -100,12 +100,18 @@ # @writable: Whether clients should be able to write to the device via the # NBD connection (default false). # +# @bitmap: Also export a single dirty bitmap reachable from @device, so the +# NBD client can use NBD_OPT_SET_META_CONTEXT with the metadata +# context name "qemu:dirty-bitmap:BITMAP" to inspect the bitmap +# (since 4.0). Mutually exclusive with @bitmaps, and newer +# clients should use that instead. +# # Since: 5.0 ## { 'struct': 'NbdServerAddOptions', 'base': 'BlockExportOptionsNbd', 'data': { 'device': 'str', - '*writable': 'bool' } } + '*writable': 'bool', '*bitmap': 'str' } } ## # @nbd-server-add: diff --git a/blockdev-nbd.c b/blockdev-nbd.c index cee9134b12eb..cfd46223bf4d 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -192,6 +192,19 @@ void qmp_nbd_server_add(NbdServerAddOptions *arg, Error **errp) return; } + /* + * New code should use the list 'bitmaps'; but until this code is + * gone, we must support the older single 'bitmap'. Use only one. + */ + if (arg->has_bitmap) { + if (arg->has_bitmaps) { + error_setg(errp, "Can't mix 'bitmap' and 'bitmaps'"); + return; + } + arg->has_bitmaps = true; + QAPI_LIST_ADD(arg->bitmaps, g_strdup(arg->bitmap)); + } + /* * block-export-add would default to the node-name, but we may have to use * the device name as a default here for compatibility. diff --git a/nbd/server.c b/nbd/server.c index 30cfe0eee467..884ffa00f1bd 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1495,6 +1495,7 @@ static int nbd_export_create(BlockExport *blk_exp, BlockExportOptions *exp_args, uint64_t perm, shared_perm; bool readonly = !exp_args->writable; bool shared = !exp_args->writable; + strList *bitmaps; int ret; assert(exp_args->type == BLOCK_EXPORT_TYPE_NBD); @@ -1556,12 +1557,18 @@ static int nbd_export_create(BlockExport *blk_exp, BlockExportOptions *exp_args, } exp->size = QEMU_ALIGN_DOWN(size, BDRV_SECTOR_SIZE); - if (arg->bitmap) { + /* XXX Allow more than one bitmap */ + if (arg->bitmaps && arg->bitmaps->next) { + error_setg(errp, "multiple bitmaps per export not supported yet"); + return -EOPNOTSUPP; + } + for (bitmaps = arg->bitmaps; bitmaps; bitmaps = bitmaps->next) { + const char *bitmap = bitmaps->value; BlockDriverState *bs = blk_bs(blk); BdrvDirtyBitmap *bm = NULL; while (bs) { - bm = bdrv_find_dirty_bitmap(bs, arg->bitmap); + bm = bdrv_find_dirty_bitmap(bs, bitmap); if (bm != NULL) { break; } @@ -1571,7 +1578,7 @@ static int nbd_export_create(BlockExport *blk_exp, BlockExportOptions *exp_args, if (bm == NULL) { ret = -ENOENT; - error_setg(errp, "Bitmap '%s' is not found", arg->bitmap); + error_setg(errp, "Bitmap '%s' is not found", bitmap); goto fail; } @@ -1585,15 +1592,15 @@ static int nbd_export_create(BlockExport *blk_exp, BlockExportOptions *exp_args, ret = -EINVAL; error_setg(errp, "Enabled bitmap '%s' incompatible with readonly export", - arg->bitmap); + bitmap); goto fail; } bdrv_dirty_bitmap_set_busy(bm, true); exp->export_bitmap = bm; - assert(strlen(arg->bitmap) <= BDRV_BITMAP_MAX_NAME_SIZE); + assert(strlen(bitmap) <= BDRV_BITMAP_MAX_NAME_SIZE); exp->export_bitmap_context = g_strdup_printf("qemu:dirty-bitmap:%s", - arg->bitmap); + bitmap); assert(strlen(exp->export_bitmap_context) < NBD_MAX_STRING_SIZE); } diff --git a/qemu-nbd.c b/qemu-nbd.c index 847fde435a7f..5473821216f7 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -572,7 +572,7 @@ int main(int argc, char **argv) const char *export_name = NULL; /* defaults to "" later for server mode */ const char *export_description = NULL; bool alloc_depth = false; - const char *bitmap = NULL; + strList *bitmaps = NULL; const char *tlscredsid = NULL; bool imageOpts = false; bool writethrough = true; @@ -701,7 +701,7 @@ int main(int argc, char **argv) alloc_depth = true; break; case 'B': - bitmap = optarg; + QAPI_LIST_ADD(bitmaps, g_strdup(optarg)); break; case 'k': sockpath = optarg; @@ -798,7 +798,7 @@ int main(int argc, char **argv) } if (export_name || export_description || dev_offset || device || disconnect || fmt || sn_id_or_name || alloc_depth || - bitmap || seen_aio || seen_discard || seen_cache) { + bitmaps || seen_aio || seen_discard || seen_cache) { error_report("List mode is incompatible with per-device settings"); exit(EXIT_FAILURE); } @@ -1082,8 +1082,8 @@ int main(int argc, char **argv) .name = g_strdup(export_name), .has_description = !!export_description, .description = g_strdup(export_description), - .has_bitmap = !!bitmap, - .bitmap = g_strdup(bitmap), + .has_bitmaps = !!bitmaps, + .bitmaps = bitmaps, .has_allocation_depth = alloc_depth, .allocation_depth = alloc_depth, }, -- 2.29.0