| Message ID | 20190401140903.19186-5-eblake@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [PULL,01/14] qemu-img: Report bdrv_block_status failures | expand |
diff --git a/block/nbd-client.c b/block/nbd-client.c index b37a5963013..a3b70d14004 100644 --- a/block/nbd-client.c +++ b/block/nbd-client.c @@ -729,9 +729,7 @@ static int nbd_co_receive_blockstatus_reply(NBDClientSession *s, bool received = false; assert(!extent->length); - NBD_FOREACH_REPLY_CHUNK(s, iter, handle, s->info.structured_reply, - NULL, &reply, &payload) - { + NBD_FOREACH_REPLY_CHUNK(s, iter, handle, false, NULL, &reply, &payload) { int ret; NBDStructuredReplyChunk *chunk = &reply.structured;
The NBD spec is clear that when structured replies are active, a simple error reply is acceptable to any command except for NBD_CMD_READ. However, we were mistakenly requiring structured errors for NBD_CMD_BLOCK_STATUS, and hanging up on a server that gave a simple error (since qemu does not behave as such a server, we didn't notice the problem until now). Broken since its introduction in commit 78a33ab5 (v2.12). Noticed while debugging a separate failure reported by nbdkit while working out its initial implementation of BLOCK_STATUS, although it turns out that nbdkit also chose to send structured error replies for BLOCK_STATUS, so I had to manually provoke the situation by hacking qemu's server to send a simple error reply: | diff --git i/nbd/server.c w/nbd/server.c | index fd013a2817a..833288d7c45 100644 | 00--- i/nbd/server.c | +++ w/nbd/server.c | @@ -2269,6 +2269,8 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, | "discard failed", errp); | | case NBD_CMD_BLOCK_STATUS: | + return nbd_co_send_simple_reply(client, request->handle, ENOMEM, | + NULL, 0, errp); | if (!request->len) { | return nbd_send_generic_reply(client, request->handle, -EINVAL, | "need non-zero length", errp); | Signed-off-by: Eric Blake <eblake@redhat.com> Acked-by: Richard W.M. Jones <rjones@redhat.com> Message-Id: <20190325190104.30213-3-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> --- block/nbd-client.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)