12.01.2019 20:58, Eric Blake wrote: > 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: Eric Blake <ebl...@redhat.com> > Message-Id: <20181215135324.152629-14-ebl...@redhat.com> > Reviewed-by: Richard W.M. Jones <rjo...@redhat.com> > > --- > v3: Improve commit message [Rich], formatting tweak [checkpatch], > rebase to dropped patch > --- > nbd/client.c | 67 +++++++++++++++++++++++++++++++++--------------- > nbd/trace-events | 2 +- > 2 files changed, 48 insertions(+), 21 deletions(-) > > diff --git a/nbd/client.c b/nbd/client.c > index 77993890f04..3c716be2719 100644 > --- a/nbd/client.c > +++ b/nbd/client.c > @@ -629,6 +629,49 @@ static QIOChannel *nbd_receive_starttls(QIOChannel *ioc, > return QIO_CHANNEL(tioc); > } > > +/* > + * nbd_send_one_meta_context: > + * Send 0 or 1 set/list meta context queries. > + * Return 0 on success, -1 with errp set for any error > + */ > +static int nbd_send_one_meta_context(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;
n_ or nb_ prefix may make it more clear > + uint32_t context_len = 0; > + uint32_t data_len; > + char *data; > + char *p; > + > + data_len = sizeof(export_len) + export_len + sizeof(queries); > + if (query) { > + context_len = strlen(query); looks like it then should be query_len > + data_len += sizeof(context_len) + context_len; > + } else { > + assert(opt == NBD_OPT_LIST_META_CONTEXT); > + } > + data = g_malloc(data_len); > + p = data; may use p = data = g_malloc > + > + 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(uint32_t), context_len); :), aha, please, s/uint32_t/queries, as you promised Hmm, its my code. It's hard to read and not very comfortable to maintain.. In block/nbd-client.c we have payload_advance* functions, to read such formatted data, I think, it should be good to make something like this for server-part. Not about these series, of course. Interesting, troubles around "don't use be64_to_cpuS, use only be64_to_cpu", do they apply somehow to *_be_p functions family? > + memcpy(p += sizeof(context_len), query, context_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 +696,10 @@ 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_one_meta_context(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 +716,7 @@ 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); > diff --git a/nbd/trace-events b/nbd/trace-events > index c3966d2b653..59521e47a3d 100644 > --- a/nbd/trace-events > +++ b/nbd/trace-events > @@ -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" Hmm, you forget nbd_opt_lookup() With this and s/uint32_t/queries (other tiny things up to you): Reviewed-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> > 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 > -- Best regards, Vladimir