[Qemu-block] [PATCH V3] block/nfs: add support for setting debug level

[Peter Lieven]

upcoming libnfs versions will support logging debug messages. Add
support for it in qemu through a per-drive option.

Examples:
 qemu -drive if=virtio,file=nfs://...,file.debug=2
 qemu-img create -o debug=2 nfs://... 10G

Signed-off-by: Peter Lieven <address@hidden>
---
v2->v3: use a per-drive option instead of a global one. [Stefan]
v1->v2: reworked patch to accept the debug level as a cmdline
        parameter instead of an URI parameter [Stefan]

 block/nfs.c          | 28 ++++++++++++++++++++++++----
 qapi/block-core.json | 20 ++++++++++++++++----
 2 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/block/nfs.c b/block/nfs.c
index c026ff6..72a4247 100644
--- a/block/nfs.c
+++ b/block/nfs.c
@@ -233,6 +233,11 @@ static QemuOptsList runtime_opts = {
             .type = QEMU_OPT_STRING,
             .help = "URL to the NFS file",
         },
+        {
+            .name = "debug",
+            .type = QEMU_OPT_NUMBER,
+            .help = "Set libnfs debug level (default 0 = no debug)",
+        },
         { /* end of list */ }
     },
 };
@@ -277,9 +282,9 @@ static void nfs_file_close(BlockDriverState *bs)
 }
 
 static int64_t nfs_client_open(NFSClient *client, const char *filename,
-                               int flags, Error **errp)
+                               int flags, QemuOpts *opts, Error **errp)
 {
-    int ret = -EINVAL, i;
+    int ret = -EINVAL, i, debug;
     struct stat st;
     URI *uri;
     QueryParams *qp = NULL;
@@ -343,6 +348,16 @@ static int64_t nfs_client_open(NFSClient *client, const 
char *filename,
         }
     }
 
+    debug = qemu_opt_get_number(opts, "debug", 0);
+    if (debug) {
+#ifdef LIBNFS_FEATURE_DEBUG
+        nfs_set_debug(client->context, debug);
+#else
+        error_report("NFS Warning: The linked version of libnfs does"
+                     " not support setting debug levels");
+#endif
+    }
+
     ret = nfs_mount(client->context, uri->server, uri->path);
     if (ret < 0) {
         error_setg(errp, "Failed to mount nfs share: %s",
@@ -405,7 +420,7 @@ static int nfs_file_open(BlockDriverState *bs, QDict 
*options, int flags,
     }
     ret = nfs_client_open(client, qemu_opt_get(opts, "filename"),
                           (flags & BDRV_O_RDWR) ? O_RDWR : O_RDONLY,
-                          errp);
+                          opts, errp);
     if (ret < 0) {
         goto out;
     }
@@ -425,6 +440,11 @@ static QemuOptsList nfs_create_opts = {
             .type = QEMU_OPT_SIZE,
             .help = "Virtual disk size"
         },
+        {
+            .name = "debug",
+            .type = QEMU_OPT_NUMBER,
+            .help = "Set libnfs debug level (default 0 = no debug)",
+        },
         { /* end of list */ }
     }
 };
@@ -441,7 +461,7 @@ static int nfs_file_create(const char *url, QemuOpts *opts, 
Error **errp)
     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
                           BDRV_SECTOR_SIZE);
 
-    ret = nfs_client_open(client, url, O_CREAT, errp);
+    ret = nfs_client_open(client, url, O_CREAT, opts, errp);
     if (ret < 0) {
         goto out;
     }
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 7b2efb8..f43a1b1 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1381,9 +1381,9 @@
 { 'enum': 'BlockdevDriver',
   'data': [ 'archipelago', 'blkdebug', 'blkverify', 'bochs', 'cloop',
             'dmg', 'file', 'ftp', 'ftps', 'host_cdrom', 'host_device',
-            'host_floppy', 'http', 'https', 'null-aio', 'null-co', 'parallels',
-            'qcow', 'qcow2', 'qed', 'quorum', 'raw', 'tftp', 'vdi', 'vhdx',
-            'vmdk', 'vpc', 'vvfat' ] }
+            'host_floppy', 'http', 'https', 'nfs', 'null-aio', 'null-co',
+            'parallels', 'qcow', 'qcow2', 'qed', 'quorum', 'raw', 'tftp',
+            'vdi', 'vhdx', 'vmdk', 'vpc', 'vvfat' ] }
 
 ##
 # @BlockdevOptionsBase
@@ -1635,6 +1635,18 @@
             '*vport': 'int',
             '*segment': 'str' } }
 
+##
+# @BlockdevOptionsNFS
+#
+# Driver specific block device options for NFS.
+#
+# @debug:       #optional set libnfs debug level (default: 0 = disabled)
+#
+# Since: 2.4
+##
+{ 'struct': 'BlockdevOptionsNFS',
+  'base': 'BlockdevOptionsFile',
+  'data': { '*debug': 'int' } }
 
 ##
 # @BlkdebugEvent
@@ -1816,7 +1828,7 @@
       'https':      'BlockdevOptionsFile',
 # TODO iscsi: Wait for structured options
 # TODO nbd: Should take InetSocketAddress for 'host'?
-# TODO nfs: Wait for structured options
+      'nfs':        'BlockdevOptionsNFS',
       'null-aio':   'BlockdevOptionsNull',
       'null-co':    'BlockdevOptionsNull',
       'parallels':  'BlockdevOptionsGenericFormat',
-- 
1.9.1