libceph: async MON client generic requests

For map check, we are going to need to send CEPH_MSG_MON_GET_VERSION
messages asynchronously and get a callback on completion.  Refactor MON
client to allow firing off generic requests asynchronously and add an
async variant of ceph_monc_get_version().  ceph_monc_do_statfs() is
switched over and remains sync.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

1 files changed, 16 insertions, 3 deletions

diff --git a/include/linux/ceph/mon_client.h b/include/linux/ceph/mon_client.h
index c14e9d861cda..19800d9b45f3 100644
--- a/include/linux/ceph/mon_client.h
+++ b/include/linux/ceph/mon_client.h
@@ -39,20 +39,31 @@ struct ceph_mon_request {
         ceph_monc_request_func_t do_request;
 };
 
+typedef void (*ceph_monc_callback_t)(struct ceph_mon_generic_request *);
+
 /*
  * ceph_mon_generic_request is being used for the statfs and
  * mon_get_version requests which are being done a bit differently
  * because we need to get data back to the caller
  */
 struct ceph_mon_generic_request {
+        struct ceph_mon_client *monc;
         struct kref kref;
         u64 tid;
         struct rb_node node;
         int result;
-        void *buf;
+
         struct completion completion;
+        ceph_monc_callback_t complete_cb;
+        u64 private_data;          /* r_tid/linger_id */
+
         struct ceph_msg *request;  /* original request */
         struct ceph_msg *reply;    /* and reply */
+
+        union {
+                struct ceph_statfs *st;
+                u64 newest;
+        } u;
 };
 
 struct ceph_mon_client {
@@ -124,8 +135,10 @@ extern int ceph_monc_wait_osdmap(struct ceph_mon_client *monc, u32 epoch,
 extern int ceph_monc_do_statfs(struct ceph_mon_client *monc,
                                struct ceph_statfs *buf);
 
-extern int ceph_monc_do_get_version(struct ceph_mon_client *monc,
-                                    const char *what, u64 *newest);
+int ceph_monc_get_version(struct ceph_mon_client *monc, const char *what,
+                          u64 *newest);
+int ceph_monc_get_version_async(struct ceph_mon_client *monc, const char *what,
+                                ceph_monc_callback_t cb, u64 private_data);
 
 extern int ceph_monc_open_session(struct ceph_mon_client *monc);