Commit 6f302e60 authored by Vladimir Sementsov-Ogievskiy's avatar Vladimir Sementsov-Ogievskiy Committed by Eric Blake
Browse files

nbd/server: refactor nbd_trip: split out nbd_handle_request 



Split out request handling logic.

Signed-off-by: default avatarVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180308184636.178534-6-vsementsov@virtuozzo.com>
Reviewed-by: default avatarEric Blake <eblake@redhat.com>
[eblake: touch up blank line placement]
Signed-off-by: default avatarEric Blake <eblake@redhat.com>
parent 6a417599

nbd/server.c

+66 −62
Original line number Diff line number Diff line
@@ -1587,17 +1587,78 @@ static coroutine_fn int nbd_do_cmd_read(NBDClient *client, NBDRequest *request, 
    }

}



/* Handle NBD request.

 * Return -errno if sending fails. Other errors are reported directly to the

 * client as an error reply. */

static coroutine_fn int nbd_handle_request(NBDClient *client,

                                           NBDRequest *request,

                                           uint8_t *data, Error **errp)

{

    int ret;

    int flags;

    NBDExport *exp = client->exp;

    char *msg;



    switch (request->type) {

    case NBD_CMD_READ:

        return nbd_do_cmd_read(client, request, data, errp);



    case NBD_CMD_WRITE:

        flags = 0;

        if (request->flags & NBD_CMD_FLAG_FUA) {

            flags |= BDRV_REQ_FUA;

        }

        ret = blk_pwrite(exp->blk, request->from + exp->dev_offset,

                         data, request->len, flags);

        return nbd_send_generic_reply(client, request->handle, ret,

                                      "writing to file failed", errp);



    case NBD_CMD_WRITE_ZEROES:

        flags = 0;

        if (request->flags & NBD_CMD_FLAG_FUA) {

            flags |= BDRV_REQ_FUA;

        }

        if (!(request->flags & NBD_CMD_FLAG_NO_HOLE)) {

            flags |= BDRV_REQ_MAY_UNMAP;

        }

        ret = blk_pwrite_zeroes(exp->blk, request->from + exp->dev_offset,

                                request->len, flags);

        return nbd_send_generic_reply(client, request->handle, ret,

                                      "writing to file failed", errp);



    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);

        return nbd_send_generic_reply(client, request->handle, ret,

                                      "flush failed", errp);



    case NBD_CMD_TRIM:

        ret = blk_co_pdiscard(exp->blk, request->from + exp->dev_offset,

                              request->len);

        return nbd_send_generic_reply(client, request->handle, ret,

                                      "discard failed", errp);



    default:

        msg = g_strdup_printf("invalid request type (%" PRIu32 ") received",

                              request->type);

        ret = nbd_send_generic_reply(client, request->handle, -EINVAL, msg,

                                     errp);

        g_free(msg);

        return ret;

    }

}



/* Owns a reference to the NBDClient passed as opaque.  */

static coroutine_fn void nbd_trip(void *opaque)

{

    NBDClient *client = opaque;

    NBDExport *exp = client->exp;

    NBDRequestData *req;

    NBDRequest request = { 0 };    /* GCC thinks it can be used uninitialized */

    int ret;

    int flags;

    Error *local_err = NULL;

    char *msg = NULL;



    trace_nbd_trip();

    if (client->closing) {
@@ -1631,66 +1692,9 @@ static coroutine_fn void nbd_trip(void *opaque) 
        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:

        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) {

            flags |= BDRV_REQ_FUA;

        }

        ret = blk_pwrite(exp->blk, request.from + exp->dev_offset,

                         req->data, request.len, flags);

        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) {

            flags |= BDRV_REQ_FUA;

        }

        if (!(request.flags & NBD_CMD_FLAG_NO_HOLE)) {

            flags |= BDRV_REQ_MAY_UNMAP;

        }

        ret = blk_pwrite_zeroes(exp->blk, request.from + exp->dev_offset,

                                request.len, flags);

        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);

        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);

        ret = nbd_send_generic_reply(client, request.handle, ret,

                                     "discard failed", &local_err);

        break;



    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);

    } else {

        ret = nbd_handle_request(client, &request, req->data, &local_err);

    }



replied:

    if (ret < 0) {

        error_prepend(&local_err, "Failed to send reply: ");

        goto disconnect;