[PATCH] python: Support resource clearing

[Nir Soffer]

From: Nir Soffer <nsoffer(a)redhat.com&gt;

Add the missing flags kwarg to sanlock.write_resource(), and the new
sanlock.WRITE_CLEAR constant.

To clear a resource, you can do now:

    sanlock.write_resource("lockspace", "resource",
[("/path/to/resource", 0)],
                           flags=sanlock.WRITE_CLEAR)

Subsequent sanlock.read_resource() calls will return the regular error
when a resource is not found.

Signed-off-by: Nir Soffer <nsoffer(a)redhat.com&gt;
---
 python/sanlock.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/python/sanlock.c b/python/sanlock.c
index 40da92f..af89d17 100644
--- a/python/sanlock.c
+++ b/python/sanlock.c
@@ -551,25 +551,28 @@ exit_fail:
 
 /* write_resource */
 PyDoc_STRVAR(pydoc_write_resource, "\
-write_resource(lockspace, resource, disks, max_hosts=0, num_hosts=0)\n\
+write_resource(lockspace, resource, disks, max_hosts=0, num_hosts=0, flags=0)\n\
 Initialize a device to be used as sanlock resource.\n\
-The disks must be in the format: [(path, offset), ... ]");
+The disks must be in the format: [(path, offset), ... ].\n\
+If WRITE_CLEAR flag is used, the resource is cleared so subsequent read will\n\
+return an error.");
 
 static PyObject *
 py_write_resource(PyObject *self __unused, PyObject *args, PyObject *keywds)
 {
     int rv, max_hosts = 0, num_hosts = 0;
+    uint32_t flags = 0;
     const char *lockspace, *resource;
     struct sanlk_resource *rs;
     PyObject *disks;
 
     static char *kwlist[] = {"lockspace", "resource",
"disks", "max_hosts",
-                                "num_hosts", NULL};
+                                "num_hosts", "flags", NULL};
 
     /* parse python tuple */
-    if (!PyArg_ParseTupleAndKeywords(args, keywds, "ssO!|ii",
+    if (!PyArg_ParseTupleAndKeywords(args, keywds, "ssO!|iiI",
         kwlist, &lockspace, &resource, &PyList_Type, &disks,
&max_hosts,
-        &num_hosts)) {
+        &num_hosts, &flags)) {
         return NULL;
     }
 
@@ -584,7 +587,7 @@ py_write_resource(PyObject *self __unused, PyObject *args, PyObject
*keywds)
 
     /* init sanlock resource (gil disabled) */
     Py_BEGIN_ALLOW_THREADS
-    rv = sanlock_write_resource(rs, max_hosts, num_hosts, 0);
+    rv = sanlock_write_resource(rs, max_hosts, num_hosts, flags);
     Py_END_ALLOW_THREADS
 
     if (rv != 0) {
@@ -1605,6 +1608,9 @@ initsanlock(void)
     PYSNLK_INIT_ADD_CONSTANT(SANLK_REQ_FORCE, "REQ_FORCE");
     PYSNLK_INIT_ADD_CONSTANT(SANLK_REQ_GRACEFUL, "REQ_GRACEFUL");
 
+    /* resource write flags */
+    PYSNLK_INIT_ADD_CONSTANT(SANLK_WRITE_CLEAR, "WRITE_CLEAR");
+
     /* hosts list flags */
     PYSNLK_INIT_ADD_CONSTANT(SANLK_HOST_FREE, "HOST_FREE");
     PYSNLK_INIT_ADD_CONSTANT(SANLK_HOST_LIVE, "HOST_LIVE");
-- 
2.7.4