cluster: fix crash on link of named pipe in stripe/replicate vol

A crash occurs when attempting to link a named pipe on a striped,
replicated volume. The cause for this crash is attempting to deref
a NULL inode pointer in stripe_link_cbk(). The RCA for this bug
uncovered a couple of problems:

- AFR ignores the inode pointer it receives on failure (returning
  NULL).
- stripe assumes the inode pointer is valid on failure.

Either one of these changes addresses the crash, but this patch
includes both changes. AFR is modified to pass along the inode
pointer it receives (which could still be NULL). stripe is
modified to not assume the inode pointer is valid on fop failure.

BUG: 842825
Change-Id: I368849b7cfbb137a08ae5f89d26406814ff5bb09
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-on: http://review.gluster.com/3790
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

2 files changed, 11 insertions, 12 deletions

diff --git a/xlators/cluster/afr/src/afr-dir-write.c b/xlators/cluster/afr/src/afr-dir-write.c
index cf223cada79..1349fd089a9 100644
--- a/xlators/cluster/afr/src/afr-dir-write.c
+++ b/xlators/cluster/afr/src/afr-dir-write.c
@@ -865,13 +865,12 @@ afr_link_wind_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                                 local->cont.link.postparent     = *postparent;
                         }
 
-                        local->cont.link.inode    = inode;
-
                         fresh_children = local->fresh_children;
                         fresh_children[local->success_count] = child_index;
                         local->success_count++;
                 }
 
+		local->cont.link.inode = inode;
                 local->op_errno = op_errno;
         }
         UNLOCK (&frame->lock);
diff --git a/xlators/cluster/stripe/src/stripe.c b/xlators/cluster/stripe/src/stripe.c
index 9a26b5873ca..a0d5af2eae0 100644
--- a/xlators/cluster/stripe/src/stripe.c
+++ b/xlators/cluster/stripe/src/stripe.c
@@ -1951,16 +1951,6 @@ stripe_link_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
         {
                 callcnt = --local->call_count;
 
-		if (IA_ISREG(inode->ia_type)) {
-			inode_ctx_get(inode, this, (uint64_t *) &fctx);
-			if (!fctx) {
-				gf_log(this->name, GF_LOG_ERROR,
-					"failed to get stripe context");
-				op_ret = -1;
-				op_errno = EINVAL;
-			}
-		}
-
                 if (op_ret == -1) {
                         gf_log (this->name, GF_LOG_DEBUG,
                                 "%s returned error %s",
@@ -1974,6 +1964,16 @@ stripe_link_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                 if (op_ret >= 0) {
                         local->op_ret = 0;
 
+			if (IA_ISREG(inode->ia_type)) {
+				inode_ctx_get(inode, this, (uint64_t *) &fctx);
+				if (!fctx) {
+					gf_log(this->name, GF_LOG_ERROR,
+						"failed to get stripe context");
+					op_ret = -1;
+					op_errno = EINVAL;
+				}
+			}
+
                         if (FIRST_CHILD(this) == prev->this) {
                                 local->inode      = inode_ref (inode);
                                 local->stbuf      = *buf;