Commit 757b3ab9 authored by Eric Blake's avatar Eric Blake
Browse files

nbd/client: Split out nbd_send_meta_query() 



Refactor nbd_negotiate_simple_meta_context() to pull out the
code that can be reused to send a LIST request for 0 or 1 query.
No semantic change.  The old comment about 'sizeof(uint32_t)'
being equivalent to '/* number of queries */' is no longer
needed, now that we are computing 'sizeof(queries)' instead.

Signed-off-by: default avatarEric Blake <eblake@redhat.com>
Reviewed-by: default avatarRichard W.M. Jones <rjones@redhat.com>
Message-Id: <20190117193658.16413-12-eblake@redhat.com>
Reviewed-by: default avatarVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
parent 2df94eb5

nbd/client.c

+44 −20
Original line number Diff line number Diff line
@@ -629,6 +629,46 @@ static QIOChannel *nbd_receive_starttls(QIOChannel *ioc, 
    return QIO_CHANNEL(tioc);

}



/*

 * nbd_send_meta_query:

 * Send 0 or 1 set/list meta context queries.

 * Return 0 on success, -1 with errp set for any error

 */

static int nbd_send_meta_query(QIOChannel *ioc, uint32_t opt,

                               const char *export, const char *query,

                               Error **errp)

{

    int ret;

    uint32_t export_len = strlen(export);

    uint32_t queries = !!query;

    uint32_t query_len = 0;

    uint32_t data_len;

    char *data;

    char *p;



    data_len = sizeof(export_len) + export_len + sizeof(queries);

    if (query) {

        query_len = strlen(query);

        data_len += sizeof(query_len) + query_len;

    } else {

        assert(opt == NBD_OPT_LIST_META_CONTEXT);

    }

    p = data = g_malloc(data_len);



    trace_nbd_opt_meta_request(nbd_opt_lookup(opt), query ?: "(all)", export);

    stl_be_p(p, export_len);

    memcpy(p += sizeof(export_len), export, export_len);

    stl_be_p(p += export_len, queries);

    if (query) {

        stl_be_p(p += sizeof(queries), query_len);

        memcpy(p += sizeof(query_len), query, query_len);

    }



    ret = nbd_send_option_request(ioc, opt, data_len, data, errp);

    g_free(data);

    return ret;

}



/* nbd_negotiate_simple_meta_context:

 * Request the server to set the meta context for export @info->name

 * using @info->x_dirty_bitmap with a fallback to "base:allocation",
@@ -653,26 +693,10 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc, 
    NBDOptionReply reply;

    const char *context = info->x_dirty_bitmap ?: "base:allocation";

    bool received = false;

    uint32_t export_len = strlen(info->name);

    uint32_t context_len = strlen(context);

    uint32_t data_len = sizeof(export_len) + export_len +

                        sizeof(uint32_t) + /* number of queries */

                        sizeof(context_len) + context_len;

    char *data = g_malloc(data_len);

    char *p = data;



    trace_nbd_opt_meta_request(context, info->name);

    stl_be_p(p, export_len);

    memcpy(p += sizeof(export_len), info->name, export_len);

    stl_be_p(p += export_len, 1);

    stl_be_p(p += sizeof(uint32_t), context_len);

    memcpy(p += sizeof(context_len), context, context_len);



    ret = nbd_send_option_request(ioc, NBD_OPT_SET_META_CONTEXT, data_len, data,

                                  errp);

    g_free(data);

    if (ret < 0) {

        return ret;

    if (nbd_send_meta_query(ioc, NBD_OPT_SET_META_CONTEXT,

                            info->name, context, errp) < 0) {

        return -1;

    }



    if (nbd_receive_option_reply(ioc, NBD_OPT_SET_META_CONTEXT, &reply,
@@ -689,7 +713,7 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc, 
    if (reply.type == NBD_REP_META_CONTEXT) {

        char *name;



        if (reply.length != sizeof(info->context_id) + context_len) {

        if (reply.length != sizeof(info->context_id) + strlen(context)) {

            error_setg(errp, "Failed to negotiate meta context '%s', server "

                       "answered with unexpected length %" PRIu32, context,

                       reply.length);

nbd/trace-events

+1 −1
Original line number Diff line number Diff line
@@ -12,7 +12,7 @@ nbd_receive_query_exports_start(const char *wantname) "Querying export list for 
nbd_receive_query_exports_success(const char *wantname) "Found desired export name '%s'"

nbd_receive_starttls_new_client(void) "Setting up TLS"

nbd_receive_starttls_tls_handshake(void) "Starting TLS handshake"

nbd_opt_meta_request(const char *context, const char *export) "Requesting to set meta context %s for export %s"

nbd_opt_meta_request(const char *optname, const char *context, const char *export) "Requesting %s %s for export %s"

nbd_opt_meta_reply(const char *context, uint32_t id) "Received mapping of context %s to id %" PRIu32

nbd_receive_negotiate(void *tlscreds, const char *hostname) "Receiving negotiation tlscreds=%p hostname=%s"

nbd_receive_negotiate_magic(uint64_t magic) "Magic is 0x%" PRIx64