From 265ca77d8f1c82a680789bdb26fc7992077de567 Mon Sep 17 00:00:00 2001

From: John Snow <jsnow@redhat.com>

Date: Wed, 27 Mar 2019 17:22:50 +0100

Subject: [PATCH 112/163] nbd/client: Refactor nbd_opt_go() to support

 NBD_OPT_INFO

RH-Author: John Snow <jsnow@redhat.com>

Message-id: <20190327172308.31077-38-jsnow@redhat.com>

Patchwork-id: 85198

O-Subject: [RHEL-7.7 qemu-kvm-rhev PATCH 37/55] nbd/client: Refactor nbd_opt_go() to support NBD_OPT_INFO

Bugzilla: 1691009

RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

RH-Acked-by: Max Reitz <mreitz@redhat.com>

RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>

From: Eric Blake <eblake@redhat.com>

Rename the function to nbd_opt_info_or_go() with an added parameter

and slight changes to comments and trace messages, in order to

reuse the function for NBD_OPT_INFO.

Signed-off-by: Eric Blake <eblake@redhat.com>

Message-Id: <20190117193658.16413-17-eblake@redhat.com>

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

(cherry picked from commit 138796d0f545ad4b6c74ad2cbe5f6e08c454a0b9)

Signed-off-by: John Snow <jsnow@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 nbd/client.c     | 36 ++++++++++++++++++++++--------------

 nbd/trace-events |  8 ++++----

 2 files changed, 26 insertions(+), 18 deletions(-)

diff --git a/nbd/client.c b/nbd/client.c

index 6829c68..fa1657a 100644

--- a/nbd/client.c

+++ b/nbd/client.c

@@ -330,11 +330,16 @@ static int nbd_receive_list(QIOChannel *ioc, char **name, char **description,

 }

-/* Returns -1 if NBD_OPT_GO proves the export @info->name cannot be

- * used, 0 if NBD_OPT_GO is unsupported (fall back to NBD_OPT_LIST and

+/*

+ * nbd_opt_info_or_go:

+ * Send option for NBD_OPT_INFO or NBD_OPT_GO and parse the reply.

+ * Returns -1 if the option proves the export @info->name cannot be

+ * used, 0 if the option is unsupported (fall back to NBD_OPT_LIST and

  * NBD_OPT_EXPORT_NAME in that case), and > 0 if the export is good to

- * go (with the rest of @info populated). */

-static int nbd_opt_go(QIOChannel *ioc, NBDExportInfo *info, Error **errp)

+ * go (with the rest of @info populated).

+ */

+static int nbd_opt_info_or_go(QIOChannel *ioc, uint32_t opt,

+                              NBDExportInfo *info, Error **errp)

 {

     NBDOptionReply reply;

     uint32_t len = strlen(info->name);

@@ -347,7 +352,8 @@ static int nbd_opt_go(QIOChannel *ioc, NBDExportInfo *info, Error **errp)

      * flags still 0 is a witness of a broken server. */

     info->flags = 0;

-    trace_nbd_opt_go_start(info->name);

+    assert(opt == NBD_OPT_GO || opt == NBD_OPT_INFO);

+    trace_nbd_opt_info_go_start(nbd_opt_lookup(opt), info->name);

     buf = g_malloc(4 + len + 2 + 2 * info->request_sizes + 1);

     stl_be_p(buf, len);

     memcpy(buf + 4, info->name, len);

@@ -356,7 +362,7 @@ static int nbd_opt_go(QIOChannel *ioc, NBDExportInfo *info, Error **errp)

     if (info->request_sizes) {

         stw_be_p(buf + 4 + len + 2, NBD_INFO_BLOCK_SIZE);

     }

-    error = nbd_send_option_request(ioc, NBD_OPT_GO,

+    error = nbd_send_option_request(ioc, opt,

                                     4 + len + 2 + 2 * info->request_sizes,

                                     buf, errp);

     g_free(buf);

@@ -365,7 +371,7 @@ static int nbd_opt_go(QIOChannel *ioc, NBDExportInfo *info, Error **errp)

     }

     while (1) {

-        if (nbd_receive_option_reply(ioc, NBD_OPT_GO, &reply, errp) < 0) {

+        if (nbd_receive_option_reply(ioc, opt, &reply, errp) < 0) {

             return -1;

         }

         error = nbd_handle_reply_err(ioc, &reply, errp);

@@ -375,8 +381,10 @@ static int nbd_opt_go(QIOChannel *ioc, NBDExportInfo *info, Error **errp)

         len = reply.length;

         if (reply.type == NBD_REP_ACK) {

-            /* Server is done sending info and moved into transmission

-               phase, but make sure it sent flags */

+            /*

+             * Server is done sending info, and moved into transmission

+             * phase for NBD_OPT_GO, but make sure it sent flags

+             */

             if (len) {

                 error_setg(errp, "server sent invalid NBD_REP_ACK");

                 return -1;

@@ -385,7 +393,7 @@ static int nbd_opt_go(QIOChannel *ioc, NBDExportInfo *info, Error **errp)

                 error_setg(errp, "broken server omitted NBD_INFO_EXPORT");

                 return -1;

             }

-            trace_nbd_opt_go_success();

+            trace_nbd_opt_info_go_success(nbd_opt_lookup(opt));

             return 1;

         }

         if (reply.type != NBD_REP_INFO) {

@@ -479,12 +487,12 @@ static int nbd_opt_go(QIOChannel *ioc, NBDExportInfo *info, Error **errp)

                 nbd_send_opt_abort(ioc);

                 return -1;

             }

-            trace_nbd_opt_go_info_block_size(info->min_block, info->opt_block,

-                                             info->max_block);

+            trace_nbd_opt_info_block_size(info->min_block, info->opt_block,

+                                          info->max_block);

             break;

         default:

-            trace_nbd_opt_go_info_unknown(type, nbd_info_lookup(type));

+            trace_nbd_opt_info_unknown(type, nbd_info_lookup(type));

             if (nbd_drop(ioc, len, errp) < 0) {

                 error_prepend(errp, "Failed to read info payload: ");

                 nbd_send_opt_abort(ioc);

@@ -993,7 +1001,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,

          * TLS).  If it is not available, fall back to

          * NBD_OPT_LIST for nicer error messages about a missing

          * export, then use NBD_OPT_EXPORT_NAME.  */

-        result = nbd_opt_go(ioc, info, errp);

+        result = nbd_opt_info_or_go(ioc, NBD_OPT_GO, info, errp);

         if (result < 0) {

             return -EINVAL;

         }

diff --git a/nbd/trace-events b/nbd/trace-events

index 663d116..7f10ebd 100644

--- a/nbd/trace-events

+++ b/nbd/trace-events

@@ -4,10 +4,10 @@ nbd_receive_option_reply(uint32_t option, const char *optname, uint32_t type, co

 nbd_server_error_msg(uint32_t err, const char *type, const char *msg) "server reported error 0x%" PRIx32 " (%s) with additional message: %s"

 nbd_reply_err_unsup(uint32_t option, const char *name) "server doesn't understand request %" PRIu32 " (%s), attempting fallback"

 nbd_receive_list(const char *name, const char *desc) "export list includes '%s', description '%s'"

-nbd_opt_go_start(const char *name) "Attempting NBD_OPT_GO for export '%s'"

-nbd_opt_go_success(void) "Export is good to go"

-nbd_opt_go_info_unknown(int info, const char *name) "Ignoring unknown info %d (%s)"

-nbd_opt_go_info_block_size(uint32_t minimum, uint32_t preferred, uint32_t maximum) "Block sizes are 0x%" PRIx32 ", 0x%" PRIx32 ", 0x%" PRIx32

+nbd_opt_info_go_start(const char *opt, const char *name) "Attempting %s for export '%s'"

+nbd_opt_info_go_success(const char *opt) "Export is ready after %s request"

+nbd_opt_info_unknown(int info, const char *name) "Ignoring unknown info %d (%s)"

+nbd_opt_info_block_size(uint32_t minimum, uint32_t preferred, uint32_t maximum) "Block sizes are 0x%" PRIx32 ", 0x%" PRIx32 ", 0x%" PRIx32

 nbd_receive_query_exports_start(const char *wantname) "Querying export list for '%s'"

 nbd_receive_query_exports_success(const char *wantname) "Found desired export name '%s'"

 nbd_receive_starttls_new_client(void) "Setting up TLS"

-- 

1.8.3.1