patch 'reorder: fix sequence number mbuf field register' has been queued to stable release 21.11.4

[Kevin Traynor]

Hi,

FYI, your patch has been queued to stable release 21.11.4

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 03/24/23. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable/commit/b71a128da3d4951b5e872af7a9bf73905cd406a6

Thanks.

Kevin

---
>From b71a128da3d4951b5e872af7a9bf73905cd406a6 Mon Sep 17 00:00:00 2001
From: Volodymyr Fialko <vfialko at marvell.com>
Date: Mon, 13 Mar 2023 14:04:28 +0100
Subject: [PATCH] reorder: fix sequence number mbuf field register

[ upstream commit ec87595f4de01cb81878874d209fa03e6963b3e4 ]

It's possible to initialize reorder buffer with user allocated memory via
rte_reorder_init() function. In such case, rte_reorder_create() is not
required and reorder dynamic field in rte_mbuf will not be registered.

Both reorder lib and mbuf dynamic field are using `rte_mcfg_tailq`
read/write lock for synchronization. To avoid deadlocking, move reorder
buffer initialization before queue insertion.

Fixes: 01f3496695b5 ("reorder: switch sequence number to dynamic mbuf field")

Signed-off-by: Volodymyr Fialko <vfialko at marvell.com>
---
 lib/reorder/rte_reorder.c | 95 +++++++++++++++++++++++++--------------
 lib/reorder/rte_reorder.h |  1 +
 2 files changed, 62 insertions(+), 34 deletions(-)

diff --git a/lib/reorder/rte_reorder.c b/lib/reorder/rte_reorder.c
index a5b9663aa5..5d4fab17ff 100644
--- a/lib/reorder/rte_reorder.c
+++ b/lib/reorder/rte_reorder.c
@@ -62,4 +62,9 @@ rte_reorder_init(struct rte_reorder_buffer *b, unsigned int bufsize,
 	const unsigned int min_bufsize = sizeof(*b) +
 					(2 * size * sizeof(struct rte_mbuf *));
+	static const struct rte_mbuf_dynfield reorder_seqn_dynfield_desc = {
+		.name = RTE_REORDER_SEQN_DYNFIELD_NAME,
+		.size = sizeof(rte_reorder_seqn_t),
+		.align = __alignof__(rte_reorder_seqn_t),
+	};
 
 	if (b == NULL) {
@@ -88,4 +93,13 @@ rte_reorder_init(struct rte_reorder_buffer *b, unsigned int bufsize,
 	}
 
+	rte_reorder_seqn_dynfield_offset = rte_mbuf_dynfield_register(&reorder_seqn_dynfield_desc);
+	if (rte_reorder_seqn_dynfield_offset < 0) {
+		RTE_LOG(ERR, REORDER,
+			"Failed to register mbuf field for reorder sequence number, rte_errno: %i\n",
+			rte_errno);
+		rte_errno = ENOMEM;
+		return NULL;
+	}
+
 	memset(b, 0, bufsize);
 	strlcpy(b->name, name, sizeof(b->name));
@@ -100,19 +114,43 @@ rte_reorder_init(struct rte_reorder_buffer *b, unsigned int bufsize,
 }
 
+/*
+ * Insert new entry into global list.
+ * Returns pointer to already inserted entry if such exists, or to newly inserted one.
+ */
+static struct rte_tailq_entry *
+rte_reorder_entry_insert(struct rte_tailq_entry *new_te)
+{
+	struct rte_reorder_list *reorder_list;
+	struct rte_reorder_buffer *b, *nb;
+	struct rte_tailq_entry *te;
+
+	rte_mcfg_tailq_write_lock();
+
+	reorder_list = RTE_TAILQ_CAST(rte_reorder_tailq.head, rte_reorder_list);
+	/* guarantee there's no existing */
+	TAILQ_FOREACH(te, reorder_list, next) {
+		b = (struct rte_reorder_buffer *) te->data;
+		nb = (struct rte_reorder_buffer *) new_te->data;
+		if (strncmp(nb->name, b->name, RTE_REORDER_NAMESIZE) == 0)
+			break;
+	}
+
+	if (te == NULL) {
+		TAILQ_INSERT_TAIL(reorder_list, new_te, next);
+		te = new_te;
+	}
+
+	rte_mcfg_tailq_write_unlock();
+
+	return te;
+}
+
 struct rte_reorder_buffer*
 rte_reorder_create(const char *name, unsigned socket_id, unsigned int size)
 {
 	struct rte_reorder_buffer *b = NULL;
-	struct rte_tailq_entry *te;
-	struct rte_reorder_list *reorder_list;
+	struct rte_tailq_entry *te, *te_inserted;
 	const unsigned int bufsize = sizeof(struct rte_reorder_buffer) +
 					(2 * size * sizeof(struct rte_mbuf *));
-	static const struct rte_mbuf_dynfield reorder_seqn_dynfield_desc = {
-		.name = RTE_REORDER_SEQN_DYNFIELD_NAME,
-		.size = sizeof(rte_reorder_seqn_t),
-		.align = __alignof__(rte_reorder_seqn_t),
-	};
-
-	reorder_list = RTE_TAILQ_CAST(rte_reorder_tailq.head, rte_reorder_list);
 
 	/* Check user arguments. */
@@ -130,23 +168,4 @@ rte_reorder_create(const char *name, unsigned socket_id, unsigned int size)
 	}
 
-	rte_reorder_seqn_dynfield_offset =
-		rte_mbuf_dynfield_register(&reorder_seqn_dynfield_desc);
-	if (rte_reorder_seqn_dynfield_offset < 0) {
-		RTE_LOG(ERR, REORDER, "Failed to register mbuf field for reorder sequence number\n");
-		rte_errno = ENOMEM;
-		return NULL;
-	}
-
-	rte_mcfg_tailq_write_lock();
-
-	/* guarantee there's no existing */
-	TAILQ_FOREACH(te, reorder_list, next) {
-		b = (struct rte_reorder_buffer *) te->data;
-		if (strncmp(name, b->name, RTE_REORDER_NAMESIZE) == 0)
-			break;
-	}
-	if (te != NULL)
-		goto exit;
-
 	/* allocate tailq entry */
 	te = rte_zmalloc("REORDER_TAILQ_ENTRY", sizeof(*te), 0);
@@ -154,6 +173,5 @@ rte_reorder_create(const char *name, unsigned socket_id, unsigned int size)
 		RTE_LOG(ERR, REORDER, "Failed to allocate tailq entry\n");
 		rte_errno = ENOMEM;
-		b = NULL;
-		goto exit;
+		return NULL;
 	}
 
@@ -164,12 +182,21 @@ rte_reorder_create(const char *name, unsigned socket_id, unsigned int size)
 		rte_errno = ENOMEM;
 		rte_free(te);
+		return NULL;
 	} else {
-		rte_reorder_init(b, bufsize, name, size);
+		if (rte_reorder_init(b, bufsize, name, size) == NULL) {
+			rte_free(b);
+			rte_free(te);
+			return NULL;
+		}
 		te->data = (void *)b;
-		TAILQ_INSERT_TAIL(reorder_list, te, next);
 	}
 
-exit:
-	rte_mcfg_tailq_write_unlock();
+	te_inserted = rte_reorder_entry_insert(te);
+	if (te_inserted != te) {
+		rte_free(b);
+		rte_free(te);
+		return te_inserted->data;
+	}
+
 	return b;
 }
diff --git a/lib/reorder/rte_reorder.h b/lib/reorder/rte_reorder.h
index dd679da114..0620f36026 100644
--- a/lib/reorder/rte_reorder.h
+++ b/lib/reorder/rte_reorder.h
@@ -82,4 +82,5 @@ rte_reorder_create(const char *name, unsigned socket_id, unsigned int size);
  *   On error case, rte_errno will be set appropriately:
  *    - EINVAL - invalid parameters
+ *    - ENOMEM - not enough memory to register dynamic field
  */
 struct rte_reorder_buffer *
-- 
2.39.2

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2023-03-22 10:30:07.977686456 +0000
+++ 0002-reorder-fix-sequence-number-mbuf-field-register.patch	2023-03-22 10:30:07.869866511 +0000
@@ -1 +1 @@
-From ec87595f4de01cb81878874d209fa03e6963b3e4 Mon Sep 17 00:00:00 2001
+From b71a128da3d4951b5e872af7a9bf73905cd406a6 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit ec87595f4de01cb81878874d209fa03e6963b3e4 ]
+
@@ -15 +16,0 @@
-Cc: stable at dpdk.org
@@ -24 +25 @@
-index 9026403ea6..4bf36f6df6 100644
+index a5b9663aa5..5d4fab17ff 100644
@@ -163 +164 @@
-index 7ed5f66a2e..f1207f72a9 100644
+index dd679da114..0620f36026 100644
@@ -166 +167 @@
-@@ -83,4 +83,5 @@ rte_reorder_create(const char *name, unsigned socket_id, unsigned int size);
+@@ -82,4 +82,5 @@ rte_reorder_create(const char *name, unsigned socket_id, unsigned int size);