fuse-bridge: Handle graph-switch.

The purpose of this patch is to let protocol/client know when its transports can
be disconnected, without application running on gluster mount noticing any
effects of graph switch.

In order to do this, we migrate all fds and blocked locks to new graph.
Once this migration is complete and there are no in-transit frames as viewed
by fuse-bridge, we send a PARENT_DOWN event to its children. protocol/client
on receiving this event, can disconnect up its transports.

Change-Id: Idcea4bc43e23fb077ac16538b61335ebad84ba16
BUG: 767862
Reviewed-on: http://review.gluster.com/2734
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vijay@gluster.com>

1 files changed, 18 insertions, 20 deletions

diff --git a/xlators/mount/fuse/src/fuse-resolve.c b/xlators/mount/fuse/src/fuse-resolve.c
index 1af80b93c57..5a09ea0d3e9 100644
--- a/xlators/mount/fuse/src/fuse-resolve.c
+++ b/xlators/mount/fuse/src/fuse-resolve.c
@@ -80,11 +80,13 @@ fuse_resolve_entry_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
         STACK_DESTROY (frame->root);
 
         if (op_ret == -1) {
-                gf_log (this->name, ((op_errno == ENOENT) ? GF_LOG_DEBUG :
-                                     GF_LOG_WARNING),
+                gf_log (this->name, (op_errno == ENOENT)
+                        ? GF_LOG_DEBUG : GF_LOG_WARNING,
                         "%s/%s: failed to resolve (%s)",
                         uuid_utoa (resolve_loc->pargfid), resolve_loc->name,
                         strerror (op_errno));
+                resolve->op_ret = -1;
+                resolve->op_errno = op_errno;
                 goto out;
         }
 
@@ -141,12 +143,14 @@ fuse_resolve_gfid_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
         STACK_DESTROY (frame->root);
 
         if (op_ret == -1) {
-                gf_log (this->name, ((op_errno == ENOENT) ? GF_LOG_DEBUG :
-                                     GF_LOG_WARNING),
+                gf_log (this->name, (op_errno == ENOENT)
+                        ? GF_LOG_DEBUG : GF_LOG_WARNING,
                         "%s: failed to resolve (%s)",
                         uuid_utoa (resolve->resolve_loc.gfid),
 			strerror (op_errno));
                 loc_wipe (&resolve->resolve_loc);
+                resolve->op_ret = -1;
+                resolve->op_errno = op_errno;
                 goto out;
         }
 
@@ -163,6 +167,7 @@ fuse_resolve_gfid_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 	}
 
 	loc_now->parent = link_inode;
+        uuid_copy (loc_now->pargfid, link_inode->gfid);
 
 	fuse_resolve_entry (state);
 
@@ -237,13 +242,12 @@ fuse_resolve_parent_simple (fuse_state_t *state)
 
         parent = inode_find (state->itable, resolve->pargfid);
 	if (!parent) {
-		resolve->op_ret   = -1;
-		resolve->op_errno = ENOENT;
 		/* non decisive result - parent missing */
 		return 1;
 	}
 
 	loc->parent = parent;
+        uuid_copy (loc->pargfid, resolve->pargfid);
 
 	inode = inode_grep (state->itable, parent, loc->name);
 	if (inode) {
@@ -261,9 +265,6 @@ int
 fuse_resolve_parent (fuse_state_t *state)
 {
         int    ret = 0;
-        loc_t *loc = NULL;
-
-        loc  = state->loc_now;
 
         ret = fuse_resolve_parent_simple (state);
         if (ret > 0) {
@@ -302,9 +303,6 @@ fuse_resolve_inode_simple (fuse_state_t *state)
         if (inode)
 		goto found;
 
-	resolve->op_ret   = -1;
-	resolve->op_errno = ENOENT;
-
         return 1;
 found:
 	loc->inode = inode;
@@ -316,9 +314,6 @@ int
 fuse_resolve_inode (fuse_state_t *state)
 {
         int                 ret = 0;
-        loc_t              *loc = NULL;
-
-        loc  = state->loc_now;
 
         ret = fuse_resolve_inode_simple (state);
 
@@ -344,7 +339,14 @@ fuse_resolve_fd (fuse_state_t *state)
         fd = resolve->fd;
 	active_subvol = fd->inode->table->xl;
 
-	state->active_subvol = active_subvol;
+        if (state->active_subvol != active_subvol) {
+                resolve->op_ret = -1;
+                resolve->op_errno = EBADF;
+                gf_log ("fuse-resolve", GF_LOG_WARNING, "migration of fd (%p) "
+                        "did not complete, failing fop with EBADF", fd);
+        }
+
+	/* state->active_subvol = active_subvol; */
 
         fuse_resolve_continue (state);
 
@@ -434,10 +436,6 @@ fuse_resolve (fuse_state_t *state)
                 fuse_resolve_inode (state);
 
         } else {
-
-                resolve->op_ret = 0;
-                resolve->op_errno = EINVAL;
-
                 fuse_resolve_all (state);
         }