// 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\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 max_data_items, int size,
                      const char *name)
{
        dout("msgpool %s init\n", 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\n", 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\n",
                    __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\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);

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

        kref_init(&msg->kref);  /* retake single ref */
        mempool_free(msg, pool->pool);
}