[dpdk-dev] [PATCH v4] mbuf: allow dynamic flags to be used by secondary process

[Stephen Hemminger <stephen@networkplumber.org>]

The dynamic flag management is broken if rte_mbuf_dynflag_lookup()
is done in a secondary process because the local pointer to
the memzone is not ever initialized.

Fix it by using the same checks as dynfield_register().
I.e if shared memory zone has not been looked up already,
then discover it.

Fixes: 4958ca3a443a ("mbuf: support dynamic fields and flags")
Cc: olivier.matz@6wind.com
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
v4 - incorporate Oliver's fix for rte_errno

 lib/librte_mbuf/rte_mbuf_dyn.c | 26 ++++++++++----------------
 1 file changed, 10 insertions(+), 16 deletions(-)

diff --git a/lib/librte_mbuf/rte_mbuf_dyn.c b/lib/librte_mbuf/rte_mbuf_dyn.c
index 538a43f6959f..b4c31896634c 100644
--- a/lib/librte_mbuf/rte_mbuf_dyn.c
+++ b/lib/librte_mbuf/rte_mbuf_dyn.c
@@ -172,7 +172,7 @@ __mbuf_dynfield_lookup(const char *name)
 			break;
 	}
 
-	if (te == NULL) {
+	if (te == NULL || mbuf_dynfield == NULL) {
 		rte_errno = ENOENT;
 		return NULL;
 	}
@@ -185,19 +185,15 @@ rte_mbuf_dynfield_lookup(const char *name, struct rte_mbuf_dynfield *params)
 {
 	struct mbuf_dynfield_elt *mbuf_dynfield;
 
-	if (shm == NULL) {
-		rte_errno = ENOENT;
-		return -1;
-	}
-
 	rte_mcfg_tailq_read_lock();
-	mbuf_dynfield = __mbuf_dynfield_lookup(name);
+	if (shm == NULL && init_shared_mem() < 0)
+		mbuf_dynfield = NULL;
+	else
+		mbuf_dynfield = __mbuf_dynfield_lookup(name);
 	rte_mcfg_tailq_read_unlock();
 
-	if (mbuf_dynfield == NULL) {
-		rte_errno = ENOENT;
+	if (mbuf_dynfield == NULL)
 		return -1;
-	}
 
 	if (params != NULL)
 		memcpy(params, &mbuf_dynfield->params, sizeof(*params));
@@ -384,13 +380,11 @@ rte_mbuf_dynflag_lookup(const char *name,
 {
 	struct mbuf_dynflag_elt *mbuf_dynflag;
 
-	if (shm == NULL) {
-		rte_errno = ENOENT;
-		return -1;
-	}
-
 	rte_mcfg_tailq_read_lock();
-	mbuf_dynflag = __mbuf_dynflag_lookup(name);
+	if (shm == NULL && init_shared_mem() < 0)
+		mbuf_dynflag = NULL;
+	else
+		mbuf_dynflag = __mbuf_dynflag_lookup(name);
 	rte_mcfg_tailq_read_unlock();
 
 	if (mbuf_dynflag == NULL) {
-- 
2.27.0