[Qemu-block] [PATCH v4 14/25] block/nfs: Implement bdrv_dirname()

[Max Reitz]

While the basic idea is obvious and could be handled by the default
bdrv_dirname() implementation, we cannot generate a directory name if
the gid or uid are set, so we have to explicitly return NULL in those
cases.

Signed-off-by: Max Reitz <address@hidden>
---
 block/nfs.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/block/nfs.c b/block/nfs.c
index a564340d15..a6addff557 100644
--- a/block/nfs.c
+++ b/block/nfs.c
@@ -829,6 +829,19 @@ static void nfs_refresh_filename(BlockDriverState *bs, 
QDict *options)
     bs->full_open_options = opts;
 }
 
+static char *nfs_dirname(BlockDriverState *bs, Error **errp)
+{
+    NFSClient *client = bs->opaque;
+
+    if (client->uid || client->gid) {
+        error_setg(errp, "Cannot generate a base directory for NBD node '%s'",
+                   bs->filename);
+        return NULL;
+    }
+
+    return g_strdup_printf("nfs://%s%s/", client->server->host, client->path);
+}
+
 #ifdef LIBNFS_FEATURE_PAGECACHE
 static void nfs_invalidate_cache(BlockDriverState *bs,
                                  Error **errp)
@@ -862,6 +875,7 @@ static BlockDriver bdrv_nfs = {
     .bdrv_detach_aio_context        = nfs_detach_aio_context,
     .bdrv_attach_aio_context        = nfs_attach_aio_context,
     .bdrv_refresh_filename          = nfs_refresh_filename,
+    .bdrv_dirname                   = nfs_dirname,
 
 #ifdef LIBNFS_FEATURE_PAGECACHE
     .bdrv_invalidate_cache          = nfs_invalidate_cache,
-- 
2.11.0