gfapi: handle graph switch (cwd, fds, locks)

- Migrate open fds to new graph
- Migrate locks held in open fd to new fd
- Refresh CWD, so resolution of relative paths happens on refreshed
  inode (on new graph).

Change-Id: I4b18083b9b290107ebda1f917fc85b635ab72fb4
BUG: 953694
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/5059
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Raghavendra G <raghavendra@gluster.com>

1 files changed, 38 insertions, 7 deletions

diff --git a/api/src/glfs-master.c b/api/src/glfs-master.c
index e6c46e361..09a92b7f0 100644
--- a/api/src/glfs-master.c
+++ b/api/src/glfs-master.c
@@ -22,26 +22,57 @@
 
 #include "xlator.h"
 #include "glusterfs.h"
+
 #include "glfs-internal.h"
 
 
 int
 glfs_graph_setup (struct glfs *fs, glusterfs_graph_t *graph)
 {
-	if (fs->active_subvol == graph->top)
-		return 0;
+	xlator_t      *new_subvol = NULL;
+	xlator_t      *old_subvol = NULL;
+	inode_table_t *itable = NULL;
+	int            ret = -1;
+
+	new_subvol = graph->top;
 
+	/* This is called in a bottom-up context, it should specifically
+	   NOT be glfs_lock()
+	*/
 	pthread_mutex_lock (&fs->mutex);
 	{
-		fs->active_subvol = graph->top;
-		pthread_cond_broadcast (&fs->cond);
+		if (new_subvol->switched ||
+		    new_subvol == fs->active_subvol ||
+		    new_subvol == fs->next_subvol) {
+			/* Spurious CHILD_UP event on old graph */
+			ret = 0;
+			goto unlock;
+		}
+
+		if (!new_subvol->itable) {
+			itable = inode_table_new (131072, new_subvol);
+			if (!itable) {
+				errno = ENOMEM;
+				ret = -1;
+				goto unlock;
+			}
+
+			new_subvol->itable = itable;
+		}
+
+		old_subvol = fs->next_subvol;
+		fs->next_subvol = new_subvol;
+		fs->next_subvol->winds++; /* first ref */
+		ret = 0;
 	}
+unlock:
 	pthread_mutex_unlock (&fs->mutex);
 
-	gf_log ("glfs-master", GF_LOG_INFO, "switched to graph %s (%d)",
-		uuid_utoa ((unsigned char *)graph->graph_uuid), graph->id);
+	if (old_subvol)
+		/* wasn't picked up so far, skip */
+		glfs_subvol_done (fs, old_subvol);
 
-	return 0;
+	return ret;
 }