Commit 72deddc5 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

qemu-nbd: add client pointer to NBDRequest 



By attaching a client to an NBDRequest, we can avoid passing around the
socket descriptor and data buffer.

Also, we can now manage the reference count for the client in
nbd_request_get/put request instead of having to do it ourselved in
nbd_read.  This simplifies things when coroutines are used.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 1743b515

nbd.c

+27 −21
Original line number Diff line number Diff line
@@ -589,6 +589,7 @@ typedef struct NBDRequest NBDRequest; 


struct NBDRequest {

    QSIMPLEQ_ENTRY(NBDRequest) entry;

    NBDClient *client;

    uint8_t *data;

};
@@ -631,9 +632,11 @@ static void nbd_client_close(NBDClient *client) 
    nbd_client_put(client);

}



static NBDRequest *nbd_request_get(NBDExport *exp)

static NBDRequest *nbd_request_get(NBDClient *client)

{

    NBDRequest *req;

    NBDExport *exp = client->exp;



    if (QSIMPLEQ_EMPTY(&exp->requests)) {

        req = g_malloc0(sizeof(NBDRequest));

        req->data = qemu_blockalign(exp->bs, NBD_BUFFER_SIZE);
@@ -641,12 +644,16 @@ static NBDRequest *nbd_request_get(NBDExport *exp) 
        req = QSIMPLEQ_FIRST(&exp->requests);

        QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry);

    }

    nbd_client_get(client);

    req->client = client;

    return req;

}



static void nbd_request_put(NBDExport *exp, NBDRequest *req)

static void nbd_request_put(NBDRequest *req)

{

    QSIMPLEQ_INSERT_HEAD(&exp->requests, req, entry);

    NBDClient *client = req->client;

    QSIMPLEQ_INSERT_HEAD(&client->exp->requests, req, entry);

    nbd_client_put(client);

}



NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset,
@@ -674,9 +681,11 @@ void nbd_export_close(NBDExport *exp) 
    g_free(exp);

}



static int nbd_do_send_reply(int csock, struct nbd_reply *reply,

                             uint8_t *data, int len)

static int nbd_do_send_reply(NBDRequest *req, struct nbd_reply *reply,

                             int len)

{

    NBDClient *client = req->client;

    int csock = client->sock;

    int rc, ret;



    if (!len) {
@@ -688,7 +697,7 @@ static int nbd_do_send_reply(int csock, struct nbd_reply *reply, 
        socket_set_cork(csock, 1);

        rc = nbd_send_reply(csock, reply);

        if (rc != -1) {

            ret = write_sync(csock, data, len);

            ret = write_sync(csock, req->data, len);

            if (ret != len) {

                errno = EIO;

                rc = -1;
@@ -702,9 +711,10 @@ static int nbd_do_send_reply(int csock, struct nbd_reply *reply, 
    return rc;

}



static int nbd_do_receive_request(int csock, struct nbd_request *request,

                                  uint8_t *data)

static int nbd_do_receive_request(NBDRequest *req, struct nbd_request *request)

{

    NBDClient *client = req->client;

    int csock = client->sock;

    int rc;



    if (nbd_receive_request(csock, request) == -1) {
@@ -731,7 +741,7 @@ static int nbd_do_receive_request(int csock, struct nbd_request *request, 
    if ((request->type & NBD_CMD_MASK_COMMAND) == NBD_CMD_WRITE) {

        TRACE("Reading %u byte(s)", request->len);



        if (read_sync(csock, data, request->len) != request->len) {

        if (read_sync(csock, req->data, request->len) != request->len) {

            LOG("reading from socket failed");

            rc = -EIO;

            goto out;
@@ -745,9 +755,8 @@ out: 


static int nbd_trip(NBDClient *client)

{

    NBDRequest *req = nbd_request_get(client);

    NBDExport *exp = client->exp;

    NBDRequest *req = nbd_request_get(exp);

    int csock = client->sock;

    struct nbd_request request;

    struct nbd_reply reply;

    int rc = -1;
@@ -755,7 +764,7 @@ static int nbd_trip(NBDClient *client) 


    TRACE("Reading request.");



    ret = nbd_do_receive_request(csock, &request, req->data);

    ret = nbd_do_receive_request(req, &request);

    if (ret == -EIO) {

        goto out;

    }
@@ -790,7 +799,7 @@ static int nbd_trip(NBDClient *client) 
        }



        TRACE("Read %u byte(s)", request.len);

        if (nbd_do_send_reply(csock, &reply, req->data, request.len) < 0)

        if (nbd_do_send_reply(req, &reply, request.len) < 0)

            goto out;

        break;

    case NBD_CMD_WRITE:
@@ -821,7 +830,7 @@ static int nbd_trip(NBDClient *client) 
            }

        }



        if (nbd_do_send_reply(csock, &reply, NULL, 0) < 0)

        if (nbd_do_send_reply(req, &reply, 0) < 0)

            goto out;

        break;

    case NBD_CMD_DISC:
@@ -837,7 +846,7 @@ static int nbd_trip(NBDClient *client) 
            reply.error = -ret;

        }



        if (nbd_do_send_reply(csock, &reply, NULL, 0) < 0)

        if (nbd_do_send_reply(req, &reply, 0) < 0)

            goto out;

        break;

    case NBD_CMD_TRIM:
@@ -848,7 +857,7 @@ static int nbd_trip(NBDClient *client) 
            LOG("discard failed");

            reply.error = -ret;

        }

        if (nbd_do_send_reply(csock, &reply, NULL, 0) < 0)

        if (nbd_do_send_reply(req, &reply, 0) < 0)

            goto out;

        break;

    default:
@@ -856,7 +865,7 @@ static int nbd_trip(NBDClient *client) 
    invalid_request:

        reply.error = -EINVAL;

    error_reply:

        if (nbd_do_send_reply(csock, &reply, NULL, 0) == -1)

        if (nbd_do_send_reply(req, &reply, 0) == -1)

            goto out;

        break;

    }
@@ -865,7 +874,7 @@ static int nbd_trip(NBDClient *client) 


    rc = 0;

out:

    nbd_request_put(exp, req);

    nbd_request_put(req);

    return rc;

}
@@ -873,12 +882,9 @@ static void nbd_read(void *opaque) 
{

    NBDClient *client = opaque;



    nbd_client_get(client);

    if (nbd_trip(client) != 0) {

        nbd_client_close(client);

    }



    nbd_client_put(client);

}



NBDClient *nbd_client_new(NBDExport *exp, int csock,