[dpdk-dev] [PATCH] mempool: fix anonymous populate

[Olivier Matz <olivier.matz@6wind.com>]

The documentation says that a negative errno is returned on error, but
in most places that's not the case.

Fix the documentation and the exceptions in code. The second one
(return from populate_virt) also fixes a memory leak.

Note that testpmd was using the function correctly.

Fixes: aa10457eb4c2 ("mempool: make mempool populate and free api public")
Fixes: 6780f72fb82f ("mempool: populate with anonymous memory")
Fixes: 66e7ba0bad4c ("mempool: ensure mempool is initialized before populating")
Cc: stable@dpdk.org

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
---
 lib/librte_mempool/rte_mempool.c | 10 +++++++---
 lib/librte_mempool/rte_mempool.h |  4 ++--
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/lib/librte_mempool/rte_mempool.c b/lib/librte_mempool/rte_mempool.c
index 78d8eb941..f8d453d21 100644
--- a/lib/librte_mempool/rte_mempool.c
+++ b/lib/librte_mempool/rte_mempool.c
@@ -645,8 +645,10 @@ rte_mempool_populate_anon(struct rte_mempool *mp)
 	}
 
 	ret = mempool_ops_alloc_once(mp);
-	if (ret != 0)
-		return ret;
+	if (ret < 0) {
+		rte_errno = -ret;
+		return 0;
+	}
 
 	size = get_anon_size(mp);
 	if (size < 0) {
@@ -670,8 +672,10 @@ rte_mempool_populate_anon(struct rte_mempool *mp)
 
 	ret = rte_mempool_populate_virt(mp, addr, size, getpagesize(),
 		rte_mempool_memchunk_anon_free, addr);
-	if (ret == 0)
+	if (ret < 0) {
+		rte_errno = -ret;
 		goto fail;
+	}
 
 	return mp->populated_size;
 
diff --git a/lib/librte_mempool/rte_mempool.h b/lib/librte_mempool/rte_mempool.h
index f81152af9..0a1dc6059 100644
--- a/lib/librte_mempool/rte_mempool.h
+++ b/lib/librte_mempool/rte_mempool.h
@@ -1167,8 +1167,8 @@ int rte_mempool_populate_default(struct rte_mempool *mp);
  *   A pointer to the mempool structure.
  * @return
  *   The number of objects added on success.
- *   On error, the chunk is not added in the memory list of the
- *   mempool and a negative errno is returned.
+ *   On error, 0 is returned, rte_errno is set, and the chunk is not added in
+ *   the memory list of the mempool.
  */
 int rte_mempool_populate_anon(struct rte_mempool *mp);
 
-- 
2.20.1