// 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_new2(pool->type, pool->front_len, pool->max_data_items,
  			    gfp_mask, true);

  	if (!msg) {
  		dout("msgpool_alloc %s failed
  ", pool->name);
  	} else {
  		dout("msgpool_alloc %s %p
  ", 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
  ", pool->name, msg);
  	msg->pool = NULL;
  	ceph_msg_put(msg);

  }

  int ceph_msgpool_init(struct ceph_msgpool *pool, int type,

  		      int front_len, int max_data_items, int size,
  		      const char *name)

  {

  	dout("msgpool %s init
  ", name);

  	pool->type = type;

  	pool->front_len = front_len;

  	pool->max_data_items = max_data_items;

  	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
  ", pool->name);

  	mempool_destroy(pool->pool);

  }

  struct ceph_msg *ceph_msgpool_get(struct ceph_msgpool *pool, int front_len,
  				  int max_data_items)

  {

  	struct ceph_msg *msg;

  	if (front_len > pool->front_len ||
  	    max_data_items > pool->max_data_items) {
  		pr_warn_ratelimited("%s need %d/%d, pool %s has %d/%d
  ",
  		    __func__, front_len, max_data_items, pool->name,
  		    pool->front_len, pool->max_data_items);

  		WARN_ON_ONCE(1);

  
  		/* try to alloc a fresh message */

  		return ceph_msg_new2(pool->type, front_len, max_data_items,
  				     GFP_NOFS, false);

  	}

  	msg = mempool_alloc(pool->pool, GFP_NOFS);
  	dout("msgpool_get %s %p
  ", pool->name, msg);
  	return msg;

  }
  
  void ceph_msgpool_put(struct ceph_msgpool *pool, struct ceph_msg *msg)
  {

  	dout("msgpool_put %s %p
  ", 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);

  	msg->data_length = 0;
  	msg->num_data_items = 0;

  	kref_init(&msg->kref);  /* retake single ref */

  	mempool_free(msg, pool->pool);

  }