diff options
| -rw-r--r-- | nbd/server.c | 176 |
1 files changed, 95 insertions, 81 deletions
diff --git a/nbd/server.c b/nbd/server.c index b230ecb4fb..297d314bd0 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1521,6 +1521,72 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request, return 0; } +/* Send simple reply without a payload, or a structured error + * @error_msg is ignored if @ret >= 0 + * Returns 0 if connection is still live, -errno on failure to talk to client + */ +static coroutine_fn int nbd_send_generic_reply(NBDClient *client, + uint64_t handle, + int ret, + const char *error_msg, + Error **errp) +{ + if (client->structured_reply && ret < 0) { + return nbd_co_send_structured_error(client, handle, -ret, error_msg, + errp); + } else { + return nbd_co_send_simple_reply(client, handle, ret < 0 ? -ret : 0, + NULL, 0, errp); + } +} + +/* Handle NBD_CMD_READ request. + * Return -errno if sending fails. Other errors are reported directly to the + * client as an error reply. */ +static coroutine_fn int nbd_do_cmd_read(NBDClient *client, NBDRequest *request, + uint8_t *data, Error **errp) +{ + int ret; + NBDExport *exp = client->exp; + + assert(request->type == NBD_CMD_READ); + + /* XXX: NBD Protocol only documents use of FUA with WRITE */ + if (request->flags & NBD_CMD_FLAG_FUA) { + ret = blk_co_flush(exp->blk); + if (ret < 0) { + return nbd_send_generic_reply(client, request->handle, ret, + "flush failed", errp); + } + } + + if (client->structured_reply && !(request->flags & NBD_CMD_FLAG_DF) && + request->len) { + return nbd_co_send_sparse_read(client, request->handle, request->from, + data, request->len, errp); + } + + ret = blk_pread(exp->blk, request->from + exp->dev_offset, data, + request->len); + if (ret < 0) { + return nbd_send_generic_reply(client, request->handle, ret, + "reading from file failed", errp); + } + + if (client->structured_reply) { + if (request->len) { + return nbd_co_send_structured_read(client, request->handle, + request->from, data, + request->len, true, errp); + } else { + return nbd_co_send_structured_done(client, request->handle, errp); + } + } else { + return nbd_co_send_simple_reply(client, request->handle, 0, + data, request->len, errp); + } +} + /* Owns a reference to the NBDClient passed as opaque. */ static coroutine_fn void nbd_trip(void *opaque) { @@ -1530,7 +1596,6 @@ static coroutine_fn void nbd_trip(void *opaque) NBDRequest request = { 0 }; /* GCC thinks it can be used uninitialized */ int ret; int flags; - int reply_data_len = 0; Error *local_err = NULL; char *msg = NULL; @@ -1558,41 +1623,23 @@ static coroutine_fn void nbd_trip(void *opaque) } if (ret < 0) { - goto reply; + /* It wans't -EIO, so, according to nbd_co_receive_request() + * semantics, we should return the error to the client. */ + Error *export_err = local_err; + + local_err = NULL; + ret = nbd_send_generic_reply(client, request.handle, -EINVAL, + error_get_pretty(export_err), &local_err); + error_free(export_err); + + goto replied; } switch (request.type) { case NBD_CMD_READ: - /* XXX: NBD Protocol only documents use of FUA with WRITE */ - if (request.flags & NBD_CMD_FLAG_FUA) { - ret = blk_co_flush(exp->blk); - if (ret < 0) { - error_setg_errno(&local_err, -ret, "flush failed"); - break; - } - } - - if (client->structured_reply && !(request.flags & NBD_CMD_FLAG_DF) && - request.len) { - ret = nbd_co_send_sparse_read(req->client, request.handle, - request.from, req->data, request.len, - &local_err); - if (ret < 0) { - goto replied; - } - goto done; - } - - ret = blk_pread(exp->blk, request.from + exp->dev_offset, - req->data, request.len); - if (ret < 0) { - error_setg_errno(&local_err, -ret, "reading from file failed"); - break; - } - - reply_data_len = request.len; - + ret = nbd_do_cmd_read(client, &request, req->data, &local_err); break; + case NBD_CMD_WRITE: flags = 0; if (request.flags & NBD_CMD_FLAG_FUA) { @@ -1600,11 +1647,10 @@ static coroutine_fn void nbd_trip(void *opaque) } ret = blk_pwrite(exp->blk, request.from + exp->dev_offset, req->data, request.len, flags); - if (ret < 0) { - error_setg_errno(&local_err, -ret, "writing to file failed"); - } - + ret = nbd_send_generic_reply(client, request.handle, ret, + "writing to file failed", &local_err); break; + case NBD_CMD_WRITE_ZEROES: flags = 0; if (request.flags & NBD_CMD_FLAG_FUA) { @@ -1615,66 +1661,34 @@ static coroutine_fn void nbd_trip(void *opaque) } ret = blk_pwrite_zeroes(exp->blk, request.from + exp->dev_offset, request.len, flags); - if (ret < 0) { - error_setg_errno(&local_err, -ret, "writing to file failed"); - } - + ret = nbd_send_generic_reply(client, request.handle, ret, + "writing to file failed", &local_err); break; + case NBD_CMD_DISC: /* unreachable, thanks to special case in nbd_co_receive_request() */ abort(); case NBD_CMD_FLUSH: ret = blk_co_flush(exp->blk); - if (ret < 0) { - error_setg_errno(&local_err, -ret, "flush failed"); - } - + ret = nbd_send_generic_reply(client, request.handle, ret, + "flush failed", &local_err); break; + case NBD_CMD_TRIM: ret = blk_co_pdiscard(exp->blk, request.from + exp->dev_offset, request.len); - if (ret < 0) { - error_setg_errno(&local_err, -ret, "discard failed"); - } - + ret = nbd_send_generic_reply(client, request.handle, ret, + "discard failed", &local_err); break; - default: - error_setg(&local_err, "invalid request type (%" PRIu32 ") received", - request.type); - ret = -EINVAL; - } - -reply: - if (local_err) { - /* If we get here, local_err was not a fatal error, and should be sent - * to the client. */ - assert(ret < 0); - msg = g_strdup(error_get_pretty(local_err)); - error_report_err(local_err); - local_err = NULL; - } - if (client->structured_reply && - (ret < 0 || request.type == NBD_CMD_READ)) { - if (ret < 0) { - ret = nbd_co_send_structured_error(req->client, request.handle, - -ret, msg, &local_err); - } else if (reply_data_len) { - ret = nbd_co_send_structured_read(req->client, request.handle, - request.from, req->data, - reply_data_len, true, - &local_err); - } else { - ret = nbd_co_send_structured_done(req->client, request.handle, - &local_err); - } - } else { - ret = nbd_co_send_simple_reply(req->client, request.handle, - ret < 0 ? -ret : 0, - req->data, reply_data_len, &local_err); + default: + msg = g_strdup_printf("invalid request type (%" PRIu32 ") received", + request.type); + ret = nbd_send_generic_reply(client, request.handle, -EINVAL, msg, + &local_err); + g_free(msg); } - g_free(msg); replied: if (ret < 0) { |