Fix write-queuing logic.

The write path for followers would call STACK_WIND without incrementing
ictx->active first.  Therefore, when we got to nsr_writev_complete, we'd
decrement from zero (overflow).  That write would succeed, but then the
next would see ictx->active was set and queue instead of executing.

Change-Id: I05714165d68b91abfc7f274ef9f011204dbe496f
Signed-off-by: Jeff Darcy <jdarcy@redhat.com>

2 files changed, 9 insertions, 6 deletions

diff --git a/tests/basic/nsr.t b/tests/basic/nsr.t
index 5d6faf78e..5dd97f2bf 100755
--- a/tests/basic/nsr.t
+++ b/tests/basic/nsr.t
@@ -13,7 +13,7 @@ function get_rep_count {
 }
 
 function ping_file {
-	dd if=/dev/urandom of=$1 bs=4k count=1 2> /dev/null
+	dd if=/dev/urandom of=$1 bs=4k count=100 2> /dev/null
 }
 
 cleanup
diff --git a/xlators/cluster/nsr-server/src/all-templates.c b/xlators/cluster/nsr-server/src/all-templates.c
index 7300973d5..5a62ae507 100644
--- a/xlators/cluster/nsr-server/src/all-templates.c
+++ b/xlators/cluster/nsr-server/src/all-templates.c
@@ -258,11 +258,13 @@ nsr_$NAME$_complete (call_frame_t *frame, void *cookie, xlator_t *this,
 #endif
 
 #if defined(NSR_CG_QUEUE)
-        nsr_inode_ctx_t *ictx   = nsr_get_inode_ctx(this,local->fd->inode);
+        nsr_inode_ctx_t *ictx;
         nsr_local_t     *next;
-        if (ictx) {
-                LOCK(&ictx->lock);
-                        list_del(&local->qlinks);
+        if (local->qlinks.next != &local->qlinks) {
+                list_del(&local->qlinks);
+                ictx = nsr_get_inode_ctx(this,local->fd->inode);
+                if (ictx) {
+                    LOCK(&ictx->lock);
                         if (ictx->pending) {
                                 /*
                                  * TBD: dequeue *all* non-conflicting reqs
@@ -287,7 +289,8 @@ nsr_$NAME$_complete (call_frame_t *frame, void *cookie, xlator_t *this,
                         else {
                                 --(ictx->active);
                         }
-                UNLOCK(&ictx->lock);
+                    UNLOCK(&ictx->lock);
+                }
         }
 #endif