1. 根目录:
2. fs
3. xfs
4. kmem.h

/*
 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#ifndef __XFS_SUPPORT_KMEM_H__
#define __XFS_SUPPORT_KMEM_H__

#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>

/*
 * General memory allocation interfaces
 */

typedef unsigned __bitwise xfs_km_flags_t;
#define KM_SLEEP	((__force xfs_km_flags_t)0x0001u)
#define KM_NOSLEEP	((__force xfs_km_flags_t)0x0002u)
#define KM_NOFS		((__force xfs_km_flags_t)0x0004u)
#define KM_MAYFAIL	((__force xfs_km_flags_t)0x0008u)
#define KM_ZERO		((__force xfs_km_flags_t)0x0010u)

/*
 * We use a special process flag to avoid recursive callbacks into
 * the filesystem during transactions.  We will also issue our own
 * warnings, so we explicitly skip any generic ones (silly of us).
 */
static inline gfp_t
kmem_flags_convert(xfs_km_flags_t flags)
{
	gfp_t	lflags;

	BUG_ON(flags & ~(KM_SLEEP|KM_NOSLEEP|KM_NOFS|KM_MAYFAIL|KM_ZERO));

	if (flags & KM_NOSLEEP) {
		lflags = GFP_ATOMIC | __GFP_NOWARN;
	} else {
		lflags = GFP_KERNEL | __GFP_NOWARN;
		if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS))
			lflags &= ~__GFP_FS;
	}

	if (flags & KM_ZERO)
		lflags |= __GFP_ZERO;

	return lflags;
}

extern void *kmem_alloc(size_t, xfs_km_flags_t);
extern void *kmem_zalloc_large(size_t size, xfs_km_flags_t);
extern void *kmem_realloc(const void *, size_t, size_t, xfs_km_flags_t);
extern void  kmem_free(const void *);


extern void *kmem_zalloc_greedy(size_t *, size_t, size_t);

static inline void *
kmem_zalloc(size_t size, xfs_km_flags_t flags)
{
	return kmem_alloc(size, flags | KM_ZERO);
}

/*
 * Zone interfaces
 */

#define KM_ZONE_HWALIGN	SLAB_HWCACHE_ALIGN
#define KM_ZONE_RECLAIM	SLAB_RECLAIM_ACCOUNT
#define KM_ZONE_SPREAD	SLAB_MEM_SPREAD

#define kmem_zone	kmem_cache
#define kmem_zone_t	struct kmem_cache

static inline kmem_zone_t *
kmem_zone_init(int size, char *zone_name)
{
	return kmem_cache_create(zone_name, size, 0, 0, NULL);
}

static inline kmem_zone_t *
kmem_zone_init_flags(int size, char *zone_name, unsigned long flags,
		     void (*construct)(void *))
{
	return kmem_cache_create(zone_name, size, 0, flags, construct);
}

static inline void
kmem_zone_free(kmem_zone_t *zone, void *ptr)
{
	kmem_cache_free(zone, ptr);
}

static inline void
kmem_zone_destroy(kmem_zone_t *zone)
{
	if (zone)
		kmem_cache_destroy(zone);
}

extern void *kmem_zone_alloc(kmem_zone_t *, xfs_km_flags_t);

static inline void *
kmem_zone_zalloc(kmem_zone_t *zone, xfs_km_flags_t flags)
{
	return kmem_zone_alloc(zone, flags | KM_ZERO);
}

#endif /* __XFS_SUPPORT_KMEM_H__ */