gfapi: implement a minimial glfs_fini()

At the very least, we should PARENT_DOWN on the currently active
graph and disconnect ourselves from glusterd.

Further cleanups underway.

Change-Id: I9276686a84b0975b5ce272b4cbec1b80920d5c5c
BUG: 1004519
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/5903
Tested-by: Gluster Build System <jenkins@build.gluster.com>

2 files changed, 74 insertions, 4 deletions

diff --git a/api/src/glfs.c b/api/src/glfs.c
index efda6b67eae..f93ebee4442 100644
--- a/api/src/glfs.c
+++ b/api/src/glfs.c
@@ -20,7 +20,6 @@
   - handle SEEK_END failure in _lseek()
   - handle umask (per filesystem?)
   - make itables LRU based
-  - implement glfs_fini()
   - 0-copy for readv/writev
   - reconcile the open/creat mess
 */
@@ -51,6 +50,7 @@
 #include "glfs.h"
 #include "glfs-internal.h"
 #include "hashfn.h"
+#include "rpc-clnt.h"
 
 
 static gf_boolean_t
@@ -594,7 +594,47 @@ glfs_init (struct glfs *fs)
 int
 glfs_fini (struct glfs *fs)
 {
-	int  ret = -1;
-
-	return ret;
+        int  ret = -1;
+        xlator_t *subvol = NULL;
+        glusterfs_ctx_t *ctx = NULL;
+        call_pool_t *call_pool = NULL;
+        int countdown = 100;
+
+        ctx = fs->ctx;
+
+        if (ctx->mgmt) {
+                rpc_clnt_disable (ctx->mgmt);
+                ctx->mgmt = NULL;
+        }
+
+        __glfs_entry_fs (fs);
+
+        call_pool = fs->ctx->pool;
+
+        while (countdown--) {
+                /* give some time for background frames to finish */
+                if (!call_pool->cnt)
+                        break;
+                usleep (100000);
+        }
+        /* leaked frames may exist, we ignore */
+
+        subvol = glfs_active_subvol (fs);
+        if (subvol) {
+                /* PARENT_DOWN within glfs_subvol_done() is issued only
+                   on graph switch (new graph should activiate and
+                   decrement the extra @winds count taken in glfs_graph_setup()
+
+                   Since we are explicitly destroying, PARENT_DOWN is necessary
+                */
+                xlator_notify (subvol, GF_EVENT_PARENT_DOWN, subvol, 0);
+                /* TBD: wait for CHILD_DOWN before exiting, in case of
+                   asynchronous cleanup like graceful socket disconnection
+                   in the future.
+                */
+        }
+
+        glfs_subvol_done (fs, subvol);
+
+        return ret;
 }
diff --git a/api/src/glfs.h b/api/src/glfs.h
index f472ca4ea1e..460edf1d02c 100644
--- a/api/src/glfs.h
+++ b/api/src/glfs.h
@@ -218,6 +218,36 @@ int glfs_set_logging (glfs_t *fs, const char *logfile, int loglevel);
 int glfs_init (glfs_t *fs);
 
 
+/*
+  SYNOPSIS
+
+  glfs_fini: Cleanup and destroy the 'virtual mount'
+
+  DESCRIPTION
+
+  This function attempts to gracefully destroy glfs_t object. An attempt is
+  made to wait for all background processing to complete before returning.
+
+  glfs_fini() must be called after all operations on glfs_t is finished.
+
+  IMPORTANT
+
+  IT IS NECESSARY TO CALL glfs_fini() ON ALL THE INITIALIZED glfs_t
+  OBJECTS BEFORE TERMINATING THE PROGRAM. THERE MAY BE CACHED AND
+  UNWRITTEN / INCOMPLETE OPERATIONS STILL IN PROGRESS EVEN THOUGH THE
+  API CALLS HAVE RETURNED. glfs_fini() WILL WAIT FOR BACKGROUND OPERATIONS
+  TO COMPLETE BEFORE RETURNING, THEREBY MAKING IT SAFE FOR THE PROGRAM TO
+  EXIT.
+
+  PARAMETERS
+
+  @fs: The 'virtual mount' object to be destroyed.
+
+  RETURN VALUES
+
+   0 : Success.
+*/
+
 int glfs_fini (glfs_t *fs);
 
 /*