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Diffstat (limited to 'nbd/server.c')
-rw-r--r--nbd/server.c176
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) {