Re: [Qemu-devel] [PATCH v5 2/6] nbd/server: refactor NBDExportMetaContexts

[Eric Blake]

On 06/09/2018 10:17 AM, Vladimir Sementsov-Ogievskiy wrote:

Use NBDExport pointer instead of just export name: there no needs to


s/no needs/is no need/


store duplicated name in the struct, moreover, NBDExport will be used
further.

Signed-off-by: Vladimir Sementsov-Ogievskiy 
---
  nbd/server.c | 23 +++
  1 file changed, 11 insertions(+), 12 deletions(-)




@@ -399,10 +399,9 @@ static int nbd_negotiate_handle_list(NBDClient *client, 
Error **errp)
  return nbd_negotiate_send_rep(client, NBD_REP_ACK, errp);
  }
  
-static void nbd_check_meta_export_name(NBDClient *client)

+static void nbd_check_meta_export(NBDClient *client)
  {
-client->export_meta.valid &= !strcmp(client->exp->name,
- client->export_meta.export_name);
+client->export_meta.valid &= client->exp == client->export_meta.exp;


Changes from string comparison to pointer comparison...


@@ -853,15 +852,15 @@ static int nbd_negotiate_meta_queries(NBDClient *client,
  
  memset(meta, 0, sizeof(*meta));
  
-ret = nbd_opt_read_name(client, meta->export_name, NULL, errp);

+ret = nbd_opt_read_name(client, export_name, NULL, errp);
  if (ret <= 0) {
  return ret;
  }
  
-exp = nbd_export_find(meta->export_name);

-if (exp == NULL) {
+meta->exp = nbd_export_find(export_name);
+if (meta->exp == NULL) {


...by remembering the results of the string comparison performed under 
the hood.  Looks good.


Reviewed-by: Eric Blake 

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.   +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

[Qemu-devel] [PATCH v5 2/6] nbd/server: refactor NBDExportMetaContexts

[Vladimir Sementsov-Ogievskiy]

Use NBDExport pointer instead of just export name: there no needs to
store duplicated name in the struct, moreover, NBDExport will be used
further.

Signed-off-by: Vladimir Sementsov-Ogievskiy 
---
 nbd/server.c | 23 +++
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/nbd/server.c b/nbd/server.c
index 8e02e077ec..567561a77e 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -88,7 +88,7 @@ static QTAILQ_HEAD(, NBDExport) exports = 
QTAILQ_HEAD_INITIALIZER(exports);
  * as selected by NBD_OPT_SET_META_CONTEXT. Also used for
  * NBD_OPT_LIST_META_CONTEXT. */
 typedef struct NBDExportMetaContexts {
-char export_name[NBD_MAX_NAME_SIZE + 1];
+NBDExport *exp;
 bool valid; /* means that negotiation of the option finished without
errors */
 bool base_allocation; /* export base:allocation context (block status) */
@@ -399,10 +399,9 @@ static int nbd_negotiate_handle_list(NBDClient *client, 
Error **errp)
 return nbd_negotiate_send_rep(client, NBD_REP_ACK, errp);
 }
 
-static void nbd_check_meta_export_name(NBDClient *client)
+static void nbd_check_meta_export(NBDClient *client)
 {
-client->export_meta.valid &= !strcmp(client->exp->name,
- client->export_meta.export_name);
+client->export_meta.valid &= client->exp == client->export_meta.exp;
 }
 
 /* Send a reply to NBD_OPT_EXPORT_NAME.
@@ -456,7 +455,7 @@ static int nbd_negotiate_handle_export_name(NBDClient 
*client,
 
 QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
 nbd_export_get(client->exp);
-nbd_check_meta_export_name(client);
+nbd_check_meta_export(client);
 
 return 0;
 }
@@ -650,7 +649,7 @@ static int nbd_negotiate_handle_info(NBDClient *client, 
uint16_t myflags,
 client->exp = exp;
 QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
 nbd_export_get(client->exp);
-nbd_check_meta_export_name(client);
+nbd_check_meta_export(client);
 rc = 1;
 }
 return rc;
@@ -834,7 +833,7 @@ static int nbd_negotiate_meta_queries(NBDClient *client,
   NBDExportMetaContexts *meta, Error 
**errp)
 {
 int ret;
-NBDExport *exp;
+char export_name[NBD_MAX_NAME_SIZE + 1];
 NBDExportMetaContexts local_meta;
 uint32_t nb_queries;
 int i;
@@ -853,15 +852,15 @@ static int nbd_negotiate_meta_queries(NBDClient *client,
 
 memset(meta, 0, sizeof(*meta));
 
-ret = nbd_opt_read_name(client, meta->export_name, NULL, errp);
+ret = nbd_opt_read_name(client, export_name, NULL, errp);
 if (ret <= 0) {
 return ret;
 }
 
-exp = nbd_export_find(meta->export_name);
-if (exp == NULL) {
+meta->exp = nbd_export_find(export_name);
+if (meta->exp == NULL) {
 return nbd_opt_drop(client, NBD_REP_ERR_UNKNOWN, errp,
-"export '%s' not present", meta->export_name);
+"export '%s' not present", export_name);
 }
 
 ret = nbd_opt_read(client, &nb_queries, sizeof(nb_queries), errp);
@@ -870,7 +869,7 @@ static int nbd_negotiate_meta_queries(NBDClient *client,
 }
 cpu_to_be32s(&nb_queries);
 trace_nbd_negotiate_meta_context(nbd_opt_lookup(client->opt),
- meta->export_name, nb_queries);
+ export_name, nb_queries);
 
 if (client->opt == NBD_OPT_LIST_META_CONTEXT && !nb_queries) {
 /* enable all known contexts */
-- 
2.11.1