text: /*
   * 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
   */
  #include <linux/mm.h>
  #include <linux/highmem.h>
  #include <linux/slab.h>
  #include <linux/swap.h>
  #include <linux/blkdev.h>
  #include <linux/backing-dev.h>
  #include "time.h"
  #include "kmem.h"
  #include "xfs_message.h"
  
  /*
   * Greedy allocation.  May fail and may return vmalloced memory.
   */
  void *
  kmem_zalloc_greedy(size_t *size, size_t minsize, size_t maxsize)
  {
  	void		*ptr;
  	size_t		kmsize = maxsize;
  
  	while (!(ptr = vzalloc(kmsize))) {
  		if ((kmsize >>= 1) <= minsize)
  			kmsize = minsize;
  	}
  	if (ptr)
  		*size = kmsize;
  	return ptr;
  }
  
  void *
  kmem_alloc(size_t size, xfs_km_flags_t flags)
  {
  	int	retries = 0;
  	gfp_t	lflags = kmem_flags_convert(flags);
  	void	*ptr;
  
  	do {
  		ptr = kmalloc(size, lflags);
  		if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
  			return ptr;
  		if (!(++retries % 100))
  			xfs_err(NULL,
  		"possible memory allocation deadlock in %s (mode:0x%x)",
  					__func__, lflags);
  		congestion_wait(BLK_RW_ASYNC, HZ/50);
  	} while (1);
  }
  
  void *
  kmem_zalloc_large(size_t size, xfs_km_flags_t flags)
  {
  	void	*ptr;
  
  	ptr = kmem_zalloc(size, flags | KM_MAYFAIL);
  	if (ptr)
  		return ptr;
  	return vzalloc(size);
  }
  
  void
  kmem_free(const void *ptr)
  {
  	if (!is_vmalloc_addr(ptr)) {
  		kfree(ptr);
  	} else {
  		vfree(ptr);
  	}
  }
  
  void *
  kmem_realloc(const void *ptr, size_t newsize, size_t oldsize,
  	     xfs_km_flags_t flags)
  {
  	void	*new;
  
  	new = kmem_alloc(newsize, flags);
  	if (ptr) {
  		if (new)
  			memcpy(new, ptr,
  				((oldsize < newsize) ? oldsize : newsize));
  		kmem_free(ptr);
  	}
  	return new;
  }
  
  void *
  kmem_zone_alloc(kmem_zone_t *zone, xfs_km_flags_t flags)
  {
  	int	retries = 0;
  	gfp_t	lflags = kmem_flags_convert(flags);
  	void	*ptr;
  
  	do {
  		ptr = kmem_cache_alloc(zone, lflags);
  		if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
  			return ptr;
  		if (!(++retries % 100))
  			xfs_err(NULL,
  		"possible memory allocation deadlock in %s (mode:0x%x)",
  					__func__, lflags);
  		congestion_wait(BLK_RW_ASYNC, HZ/50);
  	} while (1);
  }
  