/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, 2012, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * lustre/ptlrpc/sec_bulk.c
 *
 * Author: Eric Mei <ericm@clusterfs.com>
 */

#define DEBUG_SUBSYSTEM S_SEC

#include <linux/libcfs/libcfs.h>
#include <linux/crypto.h>

#include <obd.h>
#include <obd_cksum.h>
#include <obd_class.h>
#include <obd_support.h>
#include <lustre_net.h>
#include <lustre_import.h>
#include <lustre_dlm.h>
#include <lustre_sec.h>

#include "ptlrpc_internal.h"

/****************************************
 * bulk encryption page pools	   *
 ****************************************/


#define POINTERS_PER_PAGE	(PAGE_CACHE_SIZE / sizeof(void *))
#define PAGES_PER_POOL		(POINTERS_PER_PAGE)

#define IDLE_IDX_MAX	    (100)
#define IDLE_IDX_WEIGHT	 (3)

#define CACHE_QUIESCENT_PERIOD  (20)

static struct ptlrpc_enc_page_pool {
	/*
	 * constants
	 */
	unsigned long    epp_max_pages;   /* maximum pages can hold, const */
	unsigned int     epp_max_pools;   /* number of pools, const */

	/*
	 * wait queue in case of not enough free pages.
	 */
	wait_queue_head_t      epp_waitq;       /* waiting threads */
	unsigned int     epp_waitqlen;    /* wait queue length */
	unsigned long    epp_pages_short; /* # of pages wanted of in-q users */
	unsigned int     epp_growing:1;   /* during adding pages */

	/*
	 * indicating how idle the pools are, from 0 to MAX_IDLE_IDX
	 * this is counted based on each time when getting pages from
	 * the pools, not based on time. which means in case that system
	 * is idled for a while but the idle_idx might still be low if no
	 * activities happened in the pools.
	 */
	unsigned long    epp_idle_idx;

	/* last shrink time due to mem tight */
	long	     epp_last_shrink;
	long	     epp_last_access;

	/*
	 * in-pool pages bookkeeping
	 */
	spinlock_t	 epp_lock;	   /* protect following fields */
	unsigned long    epp_total_pages; /* total pages in pools */
	unsigned long    epp_free_pages;  /* current pages available */

	/*
	 * statistics
	 */
	unsigned long    epp_st_max_pages;      /* # of pages ever reached */
	unsigned int     epp_st_grows;	  /* # of grows */
	unsigned int     epp_st_grow_fails;     /* # of add pages failures */
	unsigned int     epp_st_shrinks;	/* # of shrinks */
	unsigned long    epp_st_access;	 /* # of access */
	unsigned long    epp_st_missings;       /* # of cache missing */
	unsigned long    epp_st_lowfree;	/* lowest free pages reached */
	unsigned int     epp_st_max_wqlen;      /* highest waitqueue length */
	cfs_time_t       epp_st_max_wait;       /* in jeffies */
	/*
	 * pointers to pools
	 */
	struct page    ***epp_pools;
} page_pools;

/*
 * /proc/fs/lustre/sptlrpc/encrypt_page_pools
 */
int sptlrpc_proc_enc_pool_seq_show(struct seq_file *m, void *v)
{
	int     rc;

	spin_lock(&page_pools.epp_lock);

	rc = seq_printf(m,
		      "physical pages:	  %lu\n"
		      "pages per pool:	  %lu\n"
		      "max pages:	       %lu\n"
		      "max pools:	       %u\n"
		      "total pages:	     %lu\n"
		      "total free:	      %lu\n"
		      "idle index:	      %lu/100\n"
		      "last shrink:	     %lds\n"
		      "last access:	     %lds\n"
		      "max pages reached:       %lu\n"
		      "grows:		   %u\n"
		      "grows failure:	   %u\n"
		      "shrinks:		 %u\n"
		      "cache access:	    %lu\n"
		      "cache missing:	   %lu\n"
		      "low free mark:	   %lu\n"
		      "max waitqueue depth:     %u\n"
		      "max wait time:	   "CFS_TIME_T"/%u\n"
		      ,
		      totalram_pages,
		      PAGES_PER_POOL,
		      page_pools.epp_max_pages,
		      page_pools.epp_max_pools,
		      page_pools.epp_total_pages,
		      page_pools.epp_free_pages,
		      page_pools.epp_idle_idx,
		      cfs_time_current_sec() - page_pools.epp_last_shrink,
		      cfs_time_current_sec() - page_pools.epp_last_access,
		      page_pools.epp_st_max_pages,
		      page_pools.epp_st_grows,
		      page_pools.epp_st_grow_fails,
		      page_pools.epp_st_shrinks,
		      page_pools.epp_st_access,
		      page_pools.epp_st_missings,
		      page_pools.epp_st_lowfree,
		      page_pools.epp_st_max_wqlen,
		      page_pools.epp_st_max_wait, HZ
		     );

	spin_unlock(&page_pools.epp_lock);
	return rc;
}

static void enc_pools_release_free_pages(long npages)
{
	int     p_idx, g_idx;
	int     p_idx_max1, p_idx_max2;

	LASSERT(npages > 0);
	LASSERT(npages <= page_pools.epp_free_pages);
	LASSERT(page_pools.epp_free_pages <= page_pools.epp_total_pages);

	/* max pool index before the release */
	p_idx_max2 = (page_pools.epp_total_pages - 1) / PAGES_PER_POOL;

	page_pools.epp_free_pages -= npages;
	page_pools.epp_total_pages -= npages;

	/* max pool index after the release */
	p_idx_max1 = page_pools.epp_total_pages == 0 ? -1 :
		     ((page_pools.epp_total_pages - 1) / PAGES_PER_POOL);

	p_idx = page_pools.epp_free_pages / PAGES_PER_POOL;
	g_idx = page_pools.epp_free_pages % PAGES_PER_POOL;
	LASSERT(page_pools.epp_pools[p_idx]);

	while (npages--) {
		LASSERT(page_pools.epp_pools[p_idx]);
		LASSERT(page_pools.epp_pools[p_idx][g_idx] != NULL);

		__free_page(page_pools.epp_pools[p_idx][g_idx]);
		page_pools.epp_pools[p_idx][g_idx] = NULL;

		if (++g_idx == PAGES_PER_POOL) {
			p_idx++;
			g_idx = 0;
		}
	}

	/* free unused pools */
	while (p_idx_max1 < p_idx_max2) {
		LASSERT(page_pools.epp_pools[p_idx_max2]);
		OBD_FREE(page_pools.epp_pools[p_idx_max2], PAGE_CACHE_SIZE);
		page_pools.epp_pools[p_idx_max2] = NULL;
		p_idx_max2--;
	}
}

/*
 * we try to keep at least PTLRPC_MAX_BRW_PAGES pages in the pool.
 */
static unsigned long enc_pools_shrink_count(struct shrinker *s,
					    struct shrink_control *sc)
{
	/*
	 * if no pool access for a long time, we consider it's fully idle.
	 * a little race here is fine.
	 */
	if (unlikely(cfs_time_current_sec() - page_pools.epp_last_access >
		     CACHE_QUIESCENT_PERIOD)) {
		spin_lock(&page_pools.epp_lock);
		page_pools.epp_idle_idx = IDLE_IDX_MAX;
		spin_unlock(&page_pools.epp_lock);
	}

	LASSERT(page_pools.epp_idle_idx <= IDLE_IDX_MAX);
	return max((int)page_pools.epp_free_pages - PTLRPC_MAX_BRW_PAGES, 0) *
		(IDLE_IDX_MAX - page_pools.epp_idle_idx) / IDLE_IDX_MAX;
}

/*
 * we try to keep at least PTLRPC_MAX_BRW_PAGES pages in the pool.
 */
static unsigned long enc_pools_shrink_scan(struct shrinker *s,
					   struct shrink_control *sc)
{
	spin_lock(&page_pools.epp_lock);
	sc->nr_to_scan = min_t(unsigned long, sc->nr_to_scan,
			      page_pools.epp_free_pages - PTLRPC_MAX_BRW_PAGES);
	if (sc->nr_to_scan > 0) {
		enc_pools_release_free_pages(sc->nr_to_scan);
		CDEBUG(D_SEC, "released %ld pages, %ld left\n",
		       (long)sc->nr_to_scan, page_pools.epp_free_pages);

		page_pools.epp_st_shrinks++;
		page_pools.epp_last_shrink = cfs_time_current_sec();
	}
	spin_unlock(&page_pools.epp_lock);

	/*
	 * if no pool access for a long time, we consider it's fully idle.
	 * a little race here is fine.
	 */
	if (unlikely(cfs_time_current_sec() - page_pools.epp_last_access >
		     CACHE_QUIESCENT_PERIOD)) {
		spin_lock(&page_pools.epp_lock);
		page_pools.epp_idle_idx = IDLE_IDX_MAX;
		spin_unlock(&page_pools.epp_lock);
	}

	LASSERT(page_pools.epp_idle_idx <= IDLE_IDX_MAX);
	return sc->nr_to_scan;
}

static inline
int npages_to_npools(unsigned long npages)
{
	return (int) ((npages + PAGES_PER_POOL - 1) / PAGES_PER_POOL);
}

/*
 * return how many pages cleaned up.
 */
static unsigned long enc_pools_cleanup(struct page ***pools, int npools)
{
	unsigned long cleaned = 0;
	int	   i, j;

	for (i = 0; i < npools; i++) {
		if (pools[i]) {
			for (j = 0; j < PAGES_PER_POOL; j++) {
				if (pools[i][j]) {
					__free_page(pools[i][j]);
					cleaned++;
				}
			}
			OBD_FREE(pools[i], PAGE_CACHE_SIZE);
			pools[i] = NULL;
		}
	}

	return cleaned;
}

/*
 * merge @npools pointed by @pools which contains @npages new pages
 * into current pools.
 *
 * we have options to avoid most memory copy with some tricks. but we choose
 * the simplest way to avoid complexity. It's not frequently called.
 */
static void enc_pools_insert(struct page ***pools, int npools, int npages)
{
	int     freeslot;
	int     op_idx, np_idx, og_idx, ng_idx;
	int     cur_npools, end_npools;

	LASSERT(npages > 0);
	LASSERT(page_pools.epp_total_pages+npages <= page_pools.epp_max_pages);
	LASSERT(npages_to_npools(npages) == npools);
	LASSERT(page_pools.epp_growing);

	spin_lock(&page_pools.epp_lock);

	/*
	 * (1) fill all the free slots of current pools.
	 */
	/* free slots are those left by rent pages, and the extra ones with
	 * index >= total_pages, locate at the tail of last pool. */
	freeslot = page_pools.epp_total_pages % PAGES_PER_POOL;
	if (freeslot != 0)
		freeslot = PAGES_PER_POOL - freeslot;
	freeslot += page_pools.epp_total_pages - page_pools.epp_free_pages;

	op_idx = page_pools.epp_free_pages / PAGES_PER_POOL;
	og_idx = page_pools.epp_free_pages % PAGES_PER_POOL;
	np_idx = npools - 1;
	ng_idx = (npages - 1) % PAGES_PER_POOL;

	while (freeslot) {
		LASSERT(page_pools.epp_pools[op_idx][og_idx] == NULL);
		LASSERT(pools[np_idx][ng_idx] != NULL);

		page_pools.epp_pools[op_idx][og_idx] = pools[np_idx][ng_idx];
		pools[np_idx][ng_idx] = NULL;

		freeslot--;

		if (++og_idx == PAGES_PER_POOL) {
			op_idx++;
			og_idx = 0;
		}
		if (--ng_idx < 0) {
			if (np_idx == 0)
				break;
			np_idx--;
			ng_idx = PAGES_PER_POOL - 1;
		}
	}

	/*
	 * (2) add pools if needed.
	 */
	cur_npools = (page_pools.epp_total_pages + PAGES_PER_POOL - 1) /
		     PAGES_PER_POOL;
	end_npools = (page_pools.epp_total_pages + npages + PAGES_PER_POOL -1) /
		     PAGES_PER_POOL;
	LASSERT(end_npools <= page_pools.epp_max_pools);

	np_idx = 0;
	while (cur_npools < end_npools) {
		LASSERT(page_pools.epp_pools[cur_npools] == NULL);
		LASSERT(np_idx < npools);
		LASSERT(pools[np_idx] != NULL);

		page_pools.epp_pools[cur_npools++] = pools[np_idx];
		pools[np_idx++] = NULL;
	}

	page_pools.epp_total_pages += npages;
	page_pools.epp_free_pages += npages;
	page_pools.epp_st_lowfree = page_pools.epp_free_pages;

	if (page_pools.epp_total_pages > page_pools.epp_st_max_pages)
		page_pools.epp_st_max_pages = page_pools.epp_total_pages;

	CDEBUG(D_SEC, "add %d pages to total %lu\n", npages,
	       page_pools.epp_total_pages);

	spin_unlock(&page_pools.epp_lock);
}

static int enc_pools_add_pages(int npages)
{
	static DEFINE_MUTEX(add_pages_mutex);
	struct page   ***pools;
	int	     npools, alloced = 0;
	int	     i, j, rc = -ENOMEM;

	if (npages < PTLRPC_MAX_BRW_PAGES)
		npages = PTLRPC_MAX_BRW_PAGES;

	mutex_lock(&add_pages_mutex);

	if (npages + page_pools.epp_total_pages > page_pools.epp_max_pages)
		npages = page_pools.epp_max_pages - page_pools.epp_total_pages;
	LASSERT(npages > 0);

	page_pools.epp_st_grows++;

	npools = npages_to_npools(npages);
	OBD_ALLOC(pools, npools * sizeof(*pools));
	if (pools == NULL)
		goto out;

	for (i = 0; i < npools; i++) {
		OBD_ALLOC(pools[i], PAGE_CACHE_SIZE);
		if (pools[i] == NULL)
			goto out_pools;

		for (j = 0; j < PAGES_PER_POOL && alloced < npages; j++) {
			pools[i][j] = alloc_page(__GFP_IO |
						     __GFP_HIGHMEM);
			if (pools[i][j] == NULL)
				goto out_pools;

			alloced++;
		}
	}
	LASSERT(alloced == npages);

	enc_pools_insert(pools, npools, npages);
	CDEBUG(D_SEC, "added %d pages into pools\n", npages);
	rc = 0;

out_pools:
	enc_pools_cleanup(pools, npools);
	OBD_FREE(pools, npools * sizeof(*pools));
out:
	if (rc) {
		page_pools.epp_st_grow_fails++;
		CERROR("Failed to allocate %d enc pages\n", npages);
	}

	mutex_unlock(&add_pages_mutex);
	return rc;
}

static inline void enc_pools_wakeup(void)
{
	LASSERT(spin_is_locked(&page_pools.epp_lock));
	LASSERT(page_pools.epp_waitqlen >= 0);

	if (unlikely(page_pools.epp_waitqlen)) {
		LASSERT(waitqueue_active(&page_pools.epp_waitq));
		wake_up_all(&page_pools.epp_waitq);
	}
}

static int enc_pools_should_grow(int page_needed, long now)
{
	/* don't grow if someone else is growing the pools right now,
	 * or the pools has reached its full capacity
	 */
	if (page_pools.epp_growing ||
	    page_pools.epp_total_pages == page_pools.epp_max_pages)
		return 0;

	/* if total pages is not enough, we need to grow */
	if (page_pools.epp_total_pages < page_needed)
		return 1;

	/*
	 * we wanted to return 0 here if there was a shrink just happened
	 * moment ago, but this may cause deadlock if both client and ost
	 * live on single node.
	 */
#if 0
	if (now - page_pools.epp_last_shrink < 2)
		return 0;
#endif

	/*
	 * here we perhaps need consider other factors like wait queue
	 * length, idle index, etc. ?
	 */

	/* grow the pools in any other cases */
	return 1;
}

/*
 * we allocate the requested pages atomically.
 */
int sptlrpc_enc_pool_get_pages(struct ptlrpc_bulk_desc *desc)
{
	wait_queue_t  waitlink;
	unsigned long   this_idle = -1;
	cfs_time_t      tick = 0;
	long	    now;
	int	     p_idx, g_idx;
	int	     i;

	LASSERT(desc->bd_iov_count > 0);
	LASSERT(desc->bd_iov_count <= page_pools.epp_max_pages);

	/* resent bulk, enc iov might have been allocated previously */
	if (desc->bd_enc_iov != NULL)
		return 0;

	OBD_ALLOC(desc->bd_enc_iov,
		  desc->bd_iov_count * sizeof(*desc->bd_enc_iov));
	if (desc->bd_enc_iov == NULL)
		return -ENOMEM;

	spin_lock(&page_pools.epp_lock);

	page_pools.epp_st_access++;
again:
	if (unlikely(page_pools.epp_free_pages < desc->bd_iov_count)) {
		if (tick == 0)
			tick = cfs_time_current();

		now = cfs_time_current_sec();

		page_pools.epp_st_missings++;
		page_pools.epp_pages_short += desc->bd_iov_count;

		if (enc_pools_should_grow(desc->bd_iov_count, now)) {
			page_pools.epp_growing = 1;

			spin_unlock(&page_pools.epp_lock);
			enc_pools_add_pages(page_pools.epp_pages_short / 2);
			spin_lock(&page_pools.epp_lock);

			page_pools.epp_growing = 0;

			enc_pools_wakeup();
		} else {
			if (++page_pools.epp_waitqlen >
			    page_pools.epp_st_max_wqlen)
				page_pools.epp_st_max_wqlen =
						page_pools.epp_waitqlen;

			set_current_state(TASK_UNINTERRUPTIBLE);
			init_waitqueue_entry_current(&waitlink);
			add_wait_queue(&page_pools.epp_waitq, &waitlink);

			spin_unlock(&page_pools.epp_lock);
			waitq_wait(&waitlink, TASK_UNINTERRUPTIBLE);
			remove_wait_queue(&page_pools.epp_waitq, &waitlink);
			LASSERT(page_pools.epp_waitqlen > 0);
			spin_lock(&page_pools.epp_lock);
			page_pools.epp_waitqlen--;
		}

		LASSERT(page_pools.epp_pages_short >= desc->bd_iov_count);
		page_pools.epp_pages_short -= desc->bd_iov_count;

		this_idle = 0;
		goto again;
	}

	/* record max wait time */
	if (unlikely(tick != 0)) {
		tick = cfs_time_current() - tick;
		if (tick > page_pools.epp_st_max_wait)
			page_pools.epp_st_max_wait = tick;
	}

	/* proceed with rest of allocation */
	page_pools.epp_free_pages -= desc->bd_iov_count;

	p_idx = page_pools.epp_free_pages / PAGES_PER_POOL;
	g_idx = page_pools.epp_free_pages % PAGES_PER_POOL;

	for (i = 0; i < desc->bd_iov_count; i++) {
		LASSERT(page_pools.epp_pools[p_idx][g_idx] != NULL);
		desc->bd_enc_iov[i].kiov_page =
					page_pools.epp_pools[p_idx][g_idx];
		page_pools.epp_pools[p_idx][g_idx] = NULL;

		if (++g_idx == PAGES_PER_POOL) {
			p_idx++;
			g_idx = 0;
		}
	}

	if (page_pools.epp_free_pages < page_pools.epp_st_lowfree)
		page_pools.epp_st_lowfree = page_pools.epp_free_pages;

	/*
	 * new idle index = (old * weight + new) / (weight + 1)
	 */
	if (this_idle == -1) {
		this_idle = page_pools.epp_free_pages * IDLE_IDX_MAX /
			    page_pools.epp_total_pages;
	}
	page_pools.epp_idle_idx = (page_pools.epp_idle_idx * IDLE_IDX_WEIGHT +
				   this_idle) /
				  (IDLE_IDX_WEIGHT + 1);

	page_pools.epp_last_access = cfs_time_current_sec();

	spin_unlock(&page_pools.epp_lock);
	return 0;
}
EXPORT_SYMBOL(sptlrpc_enc_pool_get_pages);

void sptlrpc_enc_pool_put_pages(struct ptlrpc_bulk_desc *desc)
{
	int     p_idx, g_idx;
	int     i;

	if (desc->bd_enc_iov == NULL)
		return;

	LASSERT(desc->bd_iov_count > 0);

	spin_lock(&page_pools.epp_lock);

	p_idx = page_pools.epp_free_pages / PAGES_PER_POOL;
	g_idx = page_pools.epp_free_pages % PAGES_PER_POOL;

	LASSERT(page_pools.epp_free_pages + desc->bd_iov_count <=
		page_pools.epp_total_pages);
	LASSERT(page_pools.epp_pools[p_idx]);

	for (i = 0; i < desc->bd_iov_count; i++) {
		LASSERT(desc->bd_enc_iov[i].kiov_page != NULL);
		LASSERT(g_idx != 0 || page_pools.epp_pools[p_idx]);
		LASSERT(page_pools.epp_pools[p_idx][g_idx] == NULL);

		page_pools.epp_pools[p_idx][g_idx] =
					desc->bd_enc_iov[i].kiov_page;

		if (++g_idx == PAGES_PER_POOL) {
			p_idx++;
			g_idx = 0;
		}
	}

	page_pools.epp_free_pages += desc->bd_iov_count;

	enc_pools_wakeup();

	spin_unlock(&page_pools.epp_lock);

	OBD_FREE(desc->bd_enc_iov,
		 desc->bd_iov_count * sizeof(*desc->bd_enc_iov));
	desc->bd_enc_iov = NULL;
}
EXPORT_SYMBOL(sptlrpc_enc_pool_put_pages);

/*
 * we don't do much stuff for add_user/del_user anymore, except adding some
 * initial pages in add_user() if current pools are empty, rest would be
 * handled by the pools's self-adaption.
 */
int sptlrpc_enc_pool_add_user(void)
{
	int     need_grow = 0;

	spin_lock(&page_pools.epp_lock);
	if (page_pools.epp_growing == 0 && page_pools.epp_total_pages == 0) {
		page_pools.epp_growing = 1;
		need_grow = 1;
	}
	spin_unlock(&page_pools.epp_lock);

	if (need_grow) {
		enc_pools_add_pages(PTLRPC_MAX_BRW_PAGES +
				    PTLRPC_MAX_BRW_PAGES);

		spin_lock(&page_pools.epp_lock);
		page_pools.epp_growing = 0;
		enc_pools_wakeup();
		spin_unlock(&page_pools.epp_lock);
	}
	return 0;
}
EXPORT_SYMBOL(sptlrpc_enc_pool_add_user);

int sptlrpc_enc_pool_del_user(void)
{
	return 0;
}
EXPORT_SYMBOL(sptlrpc_enc_pool_del_user);

static inline void enc_pools_alloc(void)
{
	LASSERT(page_pools.epp_max_pools);
	OBD_ALLOC_LARGE(page_pools.epp_pools,
			page_pools.epp_max_pools *
			sizeof(*page_pools.epp_pools));
}

static inline void enc_pools_free(void)
{
	LASSERT(page_pools.epp_max_pools);
	LASSERT(page_pools.epp_pools);

	OBD_FREE_LARGE(page_pools.epp_pools,
		       page_pools.epp_max_pools *
		       sizeof(*page_pools.epp_pools));
}

static struct shrinker pools_shrinker = {
	.count_objects	= enc_pools_shrink_count,
	.scan_objects	= enc_pools_shrink_scan,
	.seeks		= DEFAULT_SEEKS,
};

int sptlrpc_enc_pool_init(void)
{
	/*
	 * maximum capacity is 1/8 of total physical memory.
	 * is the 1/8 a good number?
	 */
	page_pools.epp_max_pages = totalram_pages / 8;
	page_pools.epp_max_pools = npages_to_npools(page_pools.epp_max_pages);

	init_waitqueue_head(&page_pools.epp_waitq);
	page_pools.epp_waitqlen = 0;
	page_pools.epp_pages_short = 0;

	page_pools.epp_growing = 0;

	page_pools.epp_idle_idx = 0;
	page_pools.epp_last_shrink = cfs_time_current_sec();
	page_pools.epp_last_access = cfs_time_current_sec();

	spin_lock_init(&page_pools.epp_lock);
	page_pools.epp_total_pages = 0;
	page_pools.epp_free_pages = 0;

	page_pools.epp_st_max_pages = 0;
	page_pools.epp_st_grows = 0;
	page_pools.epp_st_grow_fails = 0;
	page_pools.epp_st_shrinks = 0;
	page_pools.epp_st_access = 0;
	page_pools.epp_st_missings = 0;
	page_pools.epp_st_lowfree = 0;
	page_pools.epp_st_max_wqlen = 0;
	page_pools.epp_st_max_wait = 0;

	enc_pools_alloc();
	if (page_pools.epp_pools == NULL)
		return -ENOMEM;

	register_shrinker(&pools_shrinker);

	return 0;
}

void sptlrpc_enc_pool_fini(void)
{
	unsigned long cleaned, npools;

	LASSERT(page_pools.epp_pools);
	LASSERT(page_pools.epp_total_pages == page_pools.epp_free_pages);

	unregister_shrinker(&pools_shrinker);

	npools = npages_to_npools(page_pools.epp_total_pages);
	cleaned = enc_pools_cleanup(page_pools.epp_pools, npools);
	LASSERT(cleaned == page_pools.epp_total_pages);

	enc_pools_free();

	if (page_pools.epp_st_access > 0) {
		CDEBUG(D_SEC,
		       "max pages %lu, grows %u, grow fails %u, shrinks %u, "
		       "access %lu, missing %lu, max qlen %u, max wait "
		       CFS_TIME_T"/%d\n",
		       page_pools.epp_st_max_pages, page_pools.epp_st_grows,
		       page_pools.epp_st_grow_fails,
		       page_pools.epp_st_shrinks, page_pools.epp_st_access,
		       page_pools.epp_st_missings, page_pools.epp_st_max_wqlen,
		       page_pools.epp_st_max_wait, HZ);
	}
}


static int cfs_hash_alg_id[] = {
	[BULK_HASH_ALG_NULL]	= CFS_HASH_ALG_NULL,
	[BULK_HASH_ALG_ADLER32]	= CFS_HASH_ALG_ADLER32,
	[BULK_HASH_ALG_CRC32]	= CFS_HASH_ALG_CRC32,
	[BULK_HASH_ALG_MD5]	= CFS_HASH_ALG_MD5,
	[BULK_HASH_ALG_SHA1]	= CFS_HASH_ALG_SHA1,
	[BULK_HASH_ALG_SHA256]	= CFS_HASH_ALG_SHA256,
	[BULK_HASH_ALG_SHA384]	= CFS_HASH_ALG_SHA384,
	[BULK_HASH_ALG_SHA512]	= CFS_HASH_ALG_SHA512,
};
const char * sptlrpc_get_hash_name(__u8 hash_alg)
{
	return cfs_crypto_hash_name(cfs_hash_alg_id[hash_alg]);
}
EXPORT_SYMBOL(sptlrpc_get_hash_name);

__u8 sptlrpc_get_hash_alg(const char *algname)
{
	return cfs_crypto_hash_alg(algname);
}
EXPORT_SYMBOL(sptlrpc_get_hash_alg);

int bulk_sec_desc_unpack(struct lustre_msg *msg, int offset, int swabbed)
{
	struct ptlrpc_bulk_sec_desc *bsd;
	int			  size = msg->lm_buflens[offset];

	bsd = lustre_msg_buf(msg, offset, sizeof(*bsd));
	if (bsd == NULL) {
		CERROR("Invalid bulk sec desc: size %d\n", size);
		return -EINVAL;
	}

	if (swabbed) {
		__swab32s(&bsd->bsd_nob);
	}

	if (unlikely(bsd->bsd_version != 0)) {
		CERROR("Unexpected version %u\n", bsd->bsd_version);
		return -EPROTO;
	}

	if (unlikely(bsd->bsd_type >= SPTLRPC_BULK_MAX)) {
		CERROR("Invalid type %u\n", bsd->bsd_type);
		return -EPROTO;
	}

	/* FIXME more sanity check here */

	if (unlikely(bsd->bsd_svc != SPTLRPC_BULK_SVC_NULL &&
		     bsd->bsd_svc != SPTLRPC_BULK_SVC_INTG &&
		     bsd->bsd_svc != SPTLRPC_BULK_SVC_PRIV)) {
		CERROR("Invalid svc %u\n", bsd->bsd_svc);
		return -EPROTO;
	}

	return 0;
}
EXPORT_SYMBOL(bulk_sec_desc_unpack);

int sptlrpc_get_bulk_checksum(struct ptlrpc_bulk_desc *desc, __u8 alg,
			      void *buf, int buflen)
{
	struct cfs_crypto_hash_desc	*hdesc;
	int				hashsize;
	char				hashbuf[64];
	unsigned int			bufsize;
	int				i, err;

	LASSERT(alg > BULK_HASH_ALG_NULL && alg < BULK_HASH_ALG_MAX);
	LASSERT(buflen >= 4);

	hdesc = cfs_crypto_hash_init(cfs_hash_alg_id[alg], NULL, 0);
	if (IS_ERR(hdesc)) {
		CERROR("Unable to initialize checksum hash %s\n",
		       cfs_crypto_hash_name(cfs_hash_alg_id[alg]));
		return PTR_ERR(hdesc);
	}

	hashsize = cfs_crypto_hash_digestsize(cfs_hash_alg_id[alg]);

	for (i = 0; i < desc->bd_iov_count; i++) {
		cfs_crypto_hash_update_page(hdesc, desc->bd_iov[i].kiov_page,
				  desc->bd_iov[i].kiov_offset & ~CFS_PAGE_MASK,
				  desc->bd_iov[i].kiov_len);
	}
	if (hashsize > buflen) {
		bufsize = sizeof(hashbuf);
		err = cfs_crypto_hash_final(hdesc, (unsigned char *)hashbuf,
					    &bufsize);
		memcpy(buf, hashbuf, buflen);
	} else {
		bufsize = buflen;
		err = cfs_crypto_hash_final(hdesc, (unsigned char *)buf,
					    &bufsize);
	}

	if (err)
		cfs_crypto_hash_final(hdesc, NULL, NULL);
	return err;
}
EXPORT_SYMBOL(sptlrpc_get_bulk_checksum);