gfapi: Bug fixes in leases processing code-path

This patch fixes below issues in gfapi lease code-path
* 'glfs_setfsleasid' should allow NULL input to be
   able to reset leaseid
* Applications should be allowed to (un)register for
  upcall notifications of type GLFS_EVENT_LEASE_RECALL
* APIs added to read contents of GLFS_EVENT_LEASE_RECALL
  argument which is of type "struct glfs_upcall_lease"

This is backport of the below mainline patch -
 https://review.gluster.org/#/c/glusterfs/+/21391

Change-Id: I3320ddf235cc82fad561e13b9457ebd64db6c76b
updates: #350
Signed-off-by: Soumya Koduri <skoduri@redhat.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/api/src/glfs-handles.h b/api/src/glfs-handles.h
index 97d90a138ac..09b3b2ed493 100644
--- a/api/src/glfs-handles.h
+++ b/api/src/glfs-handles.h
@@ -336,6 +336,26 @@ glfs_h_lease(glfs_t *fs, glfs_object_t *object, glfs_lease_t *lease) __THROW
 glfs_object_t *
 glfs_h_find_handle(glfs_t *fs, unsigned char *handle, int len) __THROW
     GFAPI_PUBLIC(glfs_h_lease, 4.0.0);
+
+/* Functions for getting details about the glfs_upcall_lease
+ *
+ * None of the pointers returned by the below functions should be free()'d,
+ * glfs_free()'d or glfs_h_close()'d by the application.
+ *
+ * Releasing of the structures is done by passing the glfs_upcall pointer
+ * to glfs_free().
+ */
+struct glfs_upcall_lease;
+typedef struct glfs_upcall_lease glfs_upcall_lease_t;
+
+glfs_object_t *
+glfs_upcall_lease_get_object(glfs_upcall_lease_t *arg) __THROW
+    GFAPI_PUBLIC(glfs_upcall_lease_get_object, 4.1.6);
+
+uint32_t
+glfs_upcall_lease_get_lease_type(glfs_upcall_lease_t *arg) __THROW
+    GFAPI_PUBLIC(glfs_upcall_lease_get_lease_type, 4.1.6);
+
 __END_DECLS
 
 #endif /* !_GLFS_HANDLES_H */