v4.19.13 snapshot.
diff --git a/net/ceph/msgpool.c b/net/ceph/msgpool.c
new file mode 100644
index 0000000..7257153
--- /dev/null
+++ b/net/ceph/msgpool.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/vmalloc.h>
+
+#include <linux/ceph/messenger.h>
+#include <linux/ceph/msgpool.h>
+
+static void *msgpool_alloc(gfp_t gfp_mask, void *arg)
+{
+ struct ceph_msgpool *pool = arg;
+ struct ceph_msg *msg;
+
+ msg = ceph_msg_new(pool->type, pool->front_len, gfp_mask, true);
+ if (!msg) {
+ dout("msgpool_alloc %s failed\n", pool->name);
+ } else {
+ dout("msgpool_alloc %s %p\n", pool->name, msg);
+ msg->pool = pool;
+ }
+ return msg;
+}
+
+static void msgpool_free(void *element, void *arg)
+{
+ struct ceph_msgpool *pool = arg;
+ struct ceph_msg *msg = element;
+
+ dout("msgpool_release %s %p\n", pool->name, msg);
+ msg->pool = NULL;
+ ceph_msg_put(msg);
+}
+
+int ceph_msgpool_init(struct ceph_msgpool *pool, int type,
+ int front_len, int size, bool blocking, const char *name)
+{
+ dout("msgpool %s init\n", name);
+ pool->type = type;
+ pool->front_len = front_len;
+ pool->pool = mempool_create(size, msgpool_alloc, msgpool_free, pool);
+ if (!pool->pool)
+ return -ENOMEM;
+ pool->name = name;
+ return 0;
+}
+
+void ceph_msgpool_destroy(struct ceph_msgpool *pool)
+{
+ dout("msgpool %s destroy\n", pool->name);
+ mempool_destroy(pool->pool);
+}
+
+struct ceph_msg *ceph_msgpool_get(struct ceph_msgpool *pool,
+ int front_len)
+{
+ struct ceph_msg *msg;
+
+ if (front_len > pool->front_len) {
+ dout("msgpool_get %s need front %d, pool size is %d\n",
+ pool->name, front_len, pool->front_len);
+ WARN_ON(1);
+
+ /* try to alloc a fresh message */
+ return ceph_msg_new(pool->type, front_len, GFP_NOFS, false);
+ }
+
+ msg = mempool_alloc(pool->pool, GFP_NOFS);
+ dout("msgpool_get %s %p\n", pool->name, msg);
+ return msg;
+}
+
+void ceph_msgpool_put(struct ceph_msgpool *pool, struct ceph_msg *msg)
+{
+ dout("msgpool_put %s %p\n", pool->name, msg);
+
+ /* reset msg front_len; user may have changed it */
+ msg->front.iov_len = pool->front_len;
+ msg->hdr.front_len = cpu_to_le32(pool->front_len);
+
+ kref_init(&msg->kref); /* retake single ref */
+ mempool_free(msg, pool->pool);
+}