From 0736b0b842bcd0acefed2523d2e0cda3876ca469 Mon Sep 17 00:00:00 2001

From: John Snow <jsnow@redhat.com>

Date: Wed, 27 Mar 2019 17:22:43 +0100

Subject: [PATCH 105/163] nbd/client: Move export name into NBDExportInfo

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

Message-id: <20190327172308.31077-31-jsnow@redhat.com>

Patchwork-id: 85203

O-Subject: [RHEL-7.7 qemu-kvm-rhev PATCH 30/55] nbd/client: Move export name into NBDExportInfo

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>

Refactor the 'name' parameter of nbd_receive_negotiate() from

being a separate parameter into being part of the in-out 'info'.

This also spills over to a simplification of nbd_opt_go().

The main driver for this refactoring is that an upcoming patch

would like to add support to qemu-nbd to list information about

all exports available on a server, where the name(s) will be

provided by the server instead of the client.  But another benefit

is that we can now allow the client to explicitly specify the

empty export name "" even when connecting to an oldstyle server

(even if qemu is no longer such a server after commit 7f7dfe2a).

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

Reviewed-by: Richard W.M. Jones <rjones@redhat.com>

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

Message-Id: <20190117193658.16413-10-eblake@redhat.com>

(cherry picked from commit 6dc1667d6881add34e9bad48ac2a848134ea8a6d)

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

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

---

 block/nbd-client.c  |  5 +++--

 include/block/nbd.h |  8 ++++----

 nbd/client.c        | 39 ++++++++++++++++++---------------------

 nbd/trace-events    |  2 +-

 qemu-nbd.c          |  6 ++++--

 5 files changed, 30 insertions(+), 30 deletions(-)

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

index ef32075..3309376 100644

--- a/block/nbd-client.c

+++ b/block/nbd-client.c

@@ -999,10 +999,11 @@ int nbd_client_init(BlockDriverState *bs,

     client->info.structured_reply = true;

     client->info.base_allocation = true;

     client->info.x_dirty_bitmap = g_strdup(x_dirty_bitmap);

-    ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), export,

-                                tlscreds, hostname,

+    client->info.name = g_strdup(export ?: "");

+    ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), tlscreds, hostname,

                                 &client->ioc, &client->info, errp);

     g_free(client->info.x_dirty_bitmap);

+    g_free(client->info.name);

     if (ret < 0) {

         logout("Failed to negotiate with the NBD server\n");

         return ret;

diff --git a/include/block/nbd.h b/include/block/nbd.h

index 24be957..00d3eb5 100644

--- a/include/block/nbd.h

+++ b/include/block/nbd.h

@@ -262,6 +262,7 @@ struct NBDExportInfo {

     /* Set by client before nbd_receive_negotiate() */

     bool request_sizes;

     char *x_dirty_bitmap;

+    char *name; /* must be non-NULL */

     /* In-out fields, set by client before nbd_receive_negotiate() and

      * updated by server results during nbd_receive_negotiate() */

@@ -279,10 +280,9 @@ struct NBDExportInfo {

 };

 typedef struct NBDExportInfo NBDExportInfo;

-int nbd_receive_negotiate(QIOChannel *ioc, const char *name,

-                          QCryptoTLSCreds *tlscreds, const char *hostname,

-                          QIOChannel **outioc, NBDExportInfo *info,

-                          Error **errp);

+int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,

+                          const char *hostname, QIOChannel **outioc,

+                          NBDExportInfo *info, Error **errp);

 int nbd_init(int fd, QIOChannelSocket *sioc, NBDExportInfo *info,

              Error **errp);

 int nbd_send_request(QIOChannel *ioc, NBDRequest *request);

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

index fd4ba8d..8227e69 100644

--- a/nbd/client.c

+++ b/nbd/client.c

@@ -330,15 +330,14 @@ static int nbd_receive_list(QIOChannel *ioc, char **name, char **description,

 }

-/* Returns -1 if NBD_OPT_GO proves the export @wantname cannot be

+/* 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_EXPORT_NAME in that case), and > 0 if the export is good to

- * go (with @info populated). */

-static int nbd_opt_go(QIOChannel *ioc, const char *wantname,

-                      NBDExportInfo *info, Error **errp)

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

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

 {

     NBDOptionReply reply;

-    uint32_t len = strlen(wantname);

+    uint32_t len = strlen(info->name);

     uint16_t type;

     int error;

     char *buf;

@@ -348,10 +347,10 @@ static int nbd_opt_go(QIOChannel *ioc, const char *wantname,

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

     info->flags = 0;

-    trace_nbd_opt_go_start(wantname);

+    trace_nbd_opt_go_start(info->name);

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

     stl_be_p(buf, len);

-    memcpy(buf + 4, wantname, len);

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

     /* At most one request, everything else up to server */

     stw_be_p(buf + 4 + len, info->request_sizes);

     if (info->request_sizes) {

@@ -753,10 +752,9 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc,

     return 0;

 }

-int nbd_receive_negotiate(QIOChannel *ioc, const char *name,

-                          QCryptoTLSCreds *tlscreds, const char *hostname,

-                          QIOChannel **outioc, NBDExportInfo *info,

-                          Error **errp)

+int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,

+                          const char *hostname, QIOChannel **outioc,

+                          NBDExportInfo *info, Error **errp)

 {

     uint64_t magic;

     int rc;

@@ -766,6 +764,8 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name,

     trace_nbd_receive_negotiate(tlscreds, hostname ? hostname : "<null>");

+    assert(info->name);

+    trace_nbd_receive_negotiate_name(info->name);

     info->structured_reply = false;

     info->base_allocation = false;

     rc = -EINVAL;

@@ -834,10 +834,6 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name,

                 goto fail;

             }

         }

-        if (!name) {

-            trace_nbd_receive_negotiate_default_name();

-            name = "";

-        }

         if (fixedNewStyle) {

             int result;

@@ -853,7 +849,8 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name,

             if (info->structured_reply && base_allocation) {

                 result = nbd_negotiate_simple_meta_context(

-                        ioc, name, info->x_dirty_bitmap ?: "base:allocation",

+                        ioc, info->name,

+                        info->x_dirty_bitmap ?: "base:allocation",

                         &info->meta_base_allocation_id, errp);

                 if (result < 0) {

                     goto fail;

@@ -866,7 +863,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name,

              * 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, name, info, errp);

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

             if (result < 0) {

                 goto fail;

             }

@@ -879,12 +876,12 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name,

              * query gives us better error reporting if the

              * export name is not available.

              */

-            if (nbd_receive_query_exports(ioc, name, errp) < 0) {

+            if (nbd_receive_query_exports(ioc, info->name, errp) < 0) {

                 goto fail;

             }

         }

         /* write the export name request */

-        if (nbd_send_option_request(ioc, NBD_OPT_EXPORT_NAME, -1, name,

+        if (nbd_send_option_request(ioc, NBD_OPT_EXPORT_NAME, -1, info->name,

                                     errp) < 0) {

             goto fail;

         }

@@ -904,8 +901,8 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name,

     } else if (magic == NBD_CLIENT_MAGIC) {

         uint32_t oldflags;

-        if (name) {

-            error_setg(errp, "Server does not support export names");

+        if (*info->name) {

+            error_setg(errp, "Server does not support non-empty export names");

             goto fail;

         }

         if (tlscreds) {

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

index d1e1ca6..c3966d2 100644

--- a/nbd/trace-events

+++ b/nbd/trace-events

@@ -17,7 +17,7 @@ nbd_opt_meta_reply(const char *context, uint32_t id) "Received mapping of contex

 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

 nbd_receive_negotiate_server_flags(uint32_t globalflags) "Global flags are 0x%" PRIx32

-nbd_receive_negotiate_default_name(void) "Using default NBD export name \"\""

+nbd_receive_negotiate_name(const char *name) "Requesting NBD export name '%s'"

 nbd_receive_negotiate_size_flags(uint64_t size, uint16_t flags) "Size is %" PRIu64 ", export flags 0x%" PRIx16

 nbd_init_set_socket(void) "Setting NBD socket"

 nbd_init_set_block_size(unsigned long block_size) "Setting block size to %lu"

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

index efca0e4..3c53870 100644

--- a/qemu-nbd.c

+++ b/qemu-nbd.c

@@ -264,7 +264,7 @@ static void *show_parts(void *arg)

 static void *nbd_client_thread(void *arg)

 {

     char *device = arg;

-    NBDExportInfo info = { .request_sizes = false, };

+    NBDExportInfo info = { .request_sizes = false, .name = g_strdup("") };

     QIOChannelSocket *sioc;

     int fd;

     int ret;

@@ -279,7 +279,7 @@ static void *nbd_client_thread(void *arg)

         goto out;

     }

-    ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL,

+    ret = nbd_receive_negotiate(QIO_CHANNEL(sioc),

                                 NULL, NULL, NULL, &info, &local_error);

     if (ret < 0) {

         if (local_error) {

@@ -318,6 +318,7 @@ static void *nbd_client_thread(void *arg)

     }

     close(fd);

     object_unref(OBJECT(sioc));

+    g_free(info.name);

     kill(getpid(), SIGTERM);

     return (void *) EXIT_SUCCESS;

@@ -326,6 +327,7 @@ out_fd:

 out_socket:

     object_unref(OBJECT(sioc));

 out:

+    g_free(info.name);

     kill(getpid(), SIGTERM);

     return (void *) EXIT_FAILURE;

 }

-- 

1.8.3.1