nbd: Switch .bdrv_co_discard() to byte-based

Another step towards killing off sector-based block APIs.

While at it, call directly into nbd-client.c instead of having
a pointless trivial wrapper in nbd.c.
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 1468624988-423-14-git-send-email-eblake@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

block/nbd-client.c

@@ -295,19 +295,20 @@ int nbd_client_co_flush(BlockDriverState *bs)
     return -reply.error;
 }
 
-int nbd_client_co_discard(BlockDriverState *bs, int64_t sector_num,
-                          int nb_sectors)
+int nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset, int count)
 {
     NbdClientSession *client = nbd_get_client_session(bs);
-    struct nbd_request request = { .type = NBD_CMD_TRIM };
+    struct nbd_request request = {
+        .type = NBD_CMD_TRIM,
+        .from = offset,
+        .len = count,
+    };
     struct nbd_reply reply;
     ssize_t ret;
 
     if (!(client->nbdflags & NBD_FLAG_SEND_TRIM)) {
         return 0;
     }
-    request.from = sector_num * 512;
-    request.len = nb_sectors * 512;
 
     nbd_coroutine_start(client, &request);
     ret = nbd_co_send_request(bs, &request, NULL);

block/nbd-client.h

@@ -44,8 +44,7 @@ int nbd_client_init(BlockDriverState *bs,
                     Error **errp);
 void nbd_client_close(BlockDriverState *bs);
 
-int nbd_client_co_discard(BlockDriverState *bs, int64_t sector_num,
-                          int nb_sectors);
+int nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset, int count);
 int nbd_client_co_flush(BlockDriverState *bs);
 int nbd_client_co_writev(BlockDriverState *bs, int64_t sector_num,
                          int nb_sectors, QEMUIOVector *qiov, int flags);

block/nbd.c

@@ -360,12 +360,6 @@ static void nbd_refresh_limits(BlockDriverState *bs, Error **errp)
     bs->bl.max_transfer = NBD_MAX_BUFFER_SIZE;
 }
 
-static int nbd_co_discard(BlockDriverState *bs, int64_t sector_num,
-                          int nb_sectors)
-{
-    return nbd_client_co_discard(bs, sector_num, nb_sectors);
-}
-
 static void nbd_close(BlockDriverState *bs)
 {
     nbd_client_close(bs);
@@ -448,7 +442,7 @@ static BlockDriver bdrv_nbd = {
     .bdrv_co_writev_flags       = nbd_client_co_writev,
     .bdrv_close                 = nbd_close,
     .bdrv_co_flush_to_os        = nbd_co_flush,
-    .bdrv_co_discard            = nbd_co_discard,
+    .bdrv_co_pdiscard           = nbd_client_co_pdiscard,
     .bdrv_refresh_limits        = nbd_refresh_limits,
     .bdrv_getlength             = nbd_getlength,
     .bdrv_detach_aio_context    = nbd_detach_aio_context,
@@ -466,7 +460,7 @@ static BlockDriver bdrv_nbd_tcp = {
     .bdrv_co_writev_flags       = nbd_client_co_writev,
     .bdrv_close                 = nbd_close,
     .bdrv_co_flush_to_os        = nbd_co_flush,
-    .bdrv_co_discard            = nbd_co_discard,
+    .bdrv_co_pdiscard           = nbd_client_co_pdiscard,
     .bdrv_refresh_limits        = nbd_refresh_limits,
     .bdrv_getlength             = nbd_getlength,
     .bdrv_detach_aio_context    = nbd_detach_aio_context,
@@ -484,7 +478,7 @@ static BlockDriver bdrv_nbd_unix = {
     .bdrv_co_writev_flags       = nbd_client_co_writev,
     .bdrv_close                 = nbd_close,
     .bdrv_co_flush_to_os        = nbd_co_flush,
-    .bdrv_co_discard            = nbd_co_discard,
+    .bdrv_co_pdiscard           = nbd_client_co_pdiscard,
     .bdrv_refresh_limits        = nbd_refresh_limits,
     .bdrv_getlength             = nbd_getlength,
     .bdrv_detach_aio_context    = nbd_detach_aio_context,