block/nbd: move from quit to state
To implement reconnect we need several states for the client:
CONNECTED, QUIT and two different CONNECTING states. CONNECTING states
will be added in the following patches. This patch implements CONNECTED
and QUIT.
QUIT means, that we should close the connection and fail all current
and further requests (like old quit = true).
CONNECTED means that connection is ok, we can send requests (like old
quit = false).
For receiving loop we use a comparison of the current state with QUIT,
because reconnect will be in the same loop, so it should be looping
until the end.
Opposite, for requests we use a comparison of the current state with
CONNECTED, as we don't want to send requests in future CONNECTING
states.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190618114328.55249-4-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
diff --git a/block/nbd.c b/block/nbd.c
index 3a243d9..d03b00f 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -53,6 +53,11 @@
bool receiving; /* waiting for connection_co? */
} NBDClientRequest;
+typedef enum NBDClientState {
+ NBD_CLIENT_CONNECTED,
+ NBD_CLIENT_QUIT
+} NBDClientState;
+
typedef struct BDRVNBDState {
QIOChannelSocket *sioc; /* The master data channel */
QIOChannel *ioc; /* The current I/O channel which may differ (eg TLS) */
@@ -62,17 +67,23 @@
CoQueue free_sema;
Coroutine *connection_co;
int in_flight;
+ NBDClientState state;
NBDClientRequest requests[MAX_NBD_REQUESTS];
NBDReply reply;
BlockDriverState *bs;
- bool quit;
/* For nbd_refresh_filename() */
SocketAddress *saddr;
char *export, *tlscredsid;
} BDRVNBDState;
+/* @ret will be used for reconnect in future */
+static void nbd_channel_error(BDRVNBDState *s, int ret)
+{
+ s->state = NBD_CLIENT_QUIT;
+}
+
static void nbd_recv_coroutines_wake_all(BDRVNBDState *s)
{
int i;
@@ -151,7 +162,7 @@
int ret = 0;
Error *local_err = NULL;
- while (!s->quit) {
+ while (s->state != NBD_CLIENT_QUIT) {
/*
* The NBD client can only really be considered idle when it has
* yielded from qio_channel_readv_all_eof(), waiting for data. This is
@@ -169,6 +180,7 @@
error_free(local_err);
}
if (ret <= 0) {
+ nbd_channel_error(s, ret ? ret : -EIO);
break;
}
@@ -183,6 +195,7 @@
!s->requests[i].receiving ||
(nbd_reply_is_structured(&s->reply) && !s->info.structured_reply))
{
+ nbd_channel_error(s, -EINVAL);
break;
}
@@ -202,7 +215,6 @@
qemu_coroutine_yield();
}
- s->quit = true;
nbd_recv_coroutines_wake_all(s);
bdrv_dec_in_flight(s->bs);
@@ -215,12 +227,18 @@
QEMUIOVector *qiov)
{
BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
- int rc, i;
+ int rc, i = -1;
qemu_co_mutex_lock(&s->send_mutex);
while (s->in_flight == MAX_NBD_REQUESTS) {
qemu_co_queue_wait(&s->free_sema, &s->send_mutex);
}
+
+ if (s->state != NBD_CLIENT_CONNECTED) {
+ rc = -EIO;
+ goto err;
+ }
+
s->in_flight++;
for (i = 0; i < MAX_NBD_REQUESTS; i++) {
@@ -238,16 +256,12 @@
request->handle = INDEX_TO_HANDLE(s, i);
- if (s->quit) {
- rc = -EIO;
- goto err;
- }
assert(s->ioc);
if (qiov) {
qio_channel_set_cork(s->ioc, true);
rc = nbd_send_request(s->ioc, request);
- if (rc >= 0 && !s->quit) {
+ if (rc >= 0 && s->state == NBD_CLIENT_CONNECTED) {
if (qio_channel_writev_all(s->ioc, qiov->iov, qiov->niov,
NULL) < 0) {
rc = -EIO;
@@ -262,9 +276,11 @@
err:
if (rc < 0) {
- s->quit = true;
- s->requests[i].coroutine = NULL;
- s->in_flight--;
+ nbd_channel_error(s, rc);
+ if (i != -1) {
+ s->requests[i].coroutine = NULL;
+ s->in_flight--;
+ }
qemu_co_queue_next(&s->free_sema);
}
qemu_co_mutex_unlock(&s->send_mutex);
@@ -556,7 +572,7 @@
s->requests[i].receiving = true;
qemu_coroutine_yield();
s->requests[i].receiving = false;
- if (s->quit) {
+ if (s->state != NBD_CLIENT_CONNECTED) {
error_setg(errp, "Connection closed");
return -EIO;
}
@@ -641,7 +657,7 @@
if (ret < 0) {
memset(reply, 0, sizeof(*reply));
- s->quit = true;
+ nbd_channel_error(s, ret);
} else {
/* For assert at loop start in nbd_connection_entry */
*reply = s->reply;
@@ -709,7 +725,7 @@
NBDReply local_reply;
NBDStructuredReplyChunk *chunk;
Error *local_err = NULL;
- if (s->quit) {
+ if (s->state != NBD_CLIENT_CONNECTED) {
error_setg(&local_err, "Connection closed");
nbd_iter_channel_error(iter, -EIO, &local_err);
goto break_loop;
@@ -734,7 +750,7 @@
}
/* Do not execute the body of NBD_FOREACH_REPLY_CHUNK for simple reply. */
- if (nbd_reply_is_simple(reply) || s->quit) {
+ if (nbd_reply_is_simple(reply) || s->state != NBD_CLIENT_CONNECTED) {
goto break_loop;
}
@@ -808,14 +824,14 @@
ret = nbd_parse_offset_hole_payload(s, &reply.structured, payload,
offset, qiov, &local_err);
if (ret < 0) {
- s->quit = true;
+ nbd_channel_error(s, ret);
nbd_iter_channel_error(&iter, ret, &local_err);
}
break;
default:
if (!nbd_reply_type_is_error(chunk->type)) {
/* not allowed reply type */
- s->quit = true;
+ nbd_channel_error(s, -EINVAL);
error_setg(&local_err,
"Unexpected reply type: %d (%s) for CMD_READ",
chunk->type, nbd_reply_type_lookup(chunk->type));
@@ -853,7 +869,7 @@
switch (chunk->type) {
case NBD_REPLY_TYPE_BLOCK_STATUS:
if (received) {
- s->quit = true;
+ nbd_channel_error(s, -EINVAL);
error_setg(&local_err, "Several BLOCK_STATUS chunks in reply");
nbd_iter_channel_error(&iter, -EINVAL, &local_err);
}
@@ -863,13 +879,13 @@
payload, length, extent,
&local_err);
if (ret < 0) {
- s->quit = true;
+ nbd_channel_error(s, ret);
nbd_iter_channel_error(&iter, ret, &local_err);
}
break;
default:
if (!nbd_reply_type_is_error(chunk->type)) {
- s->quit = true;
+ nbd_channel_error(s, -EINVAL);
error_setg(&local_err,
"Unexpected reply type: %d (%s) "
"for CMD_BLOCK_STATUS",
