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fs/xfs/kmem.c 3.08 KB
81f7e3824   Eric Lee   Initial Release, ...
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  /*
   * 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/sched/mm.h>
  #include <linux/highmem.h>
  #include <linux/slab.h>
  #include <linux/swap.h>
  #include <linux/blkdev.h>
  #include <linux/backing-dev.h>
  #include "kmem.h"
  #include "xfs_message.h"
  
  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,
  	"%s(%u) possible memory allocation deadlock size %u in %s (mode:0x%x)",
  				current->comm, current->pid,
  				(unsigned int)size, __func__, lflags);
  		congestion_wait(BLK_RW_ASYNC, HZ/50);
  	} while (1);
  }
  
  void *
  kmem_zalloc_large(size_t size, xfs_km_flags_t flags)
  {
  	unsigned nofs_flag = 0;
  	void	*ptr;
  	gfp_t	lflags;
  
  	ptr = kmem_zalloc(size, flags | KM_MAYFAIL);
  	if (ptr)
  		return ptr;
  
  	/*
  	 * __vmalloc() will allocate data pages and auxillary structures (e.g.
  	 * pagetables) with GFP_KERNEL, yet we may be under GFP_NOFS context
  	 * here. Hence we need to tell memory reclaim that we are in such a
  	 * context via PF_MEMALLOC_NOFS to prevent memory reclaim re-entering
  	 * the filesystem here and potentially deadlocking.
  	 */
  	if (flags & KM_NOFS)
  		nofs_flag = memalloc_nofs_save();
  
  	lflags = kmem_flags_convert(flags);
  	ptr = __vmalloc(size, lflags | __GFP_ZERO, PAGE_KERNEL);
  
  	if (flags & KM_NOFS)
  		memalloc_nofs_restore(nofs_flag);
  
  	return ptr;
  }
  
  void *
  kmem_realloc(const void *old, size_t newsize, xfs_km_flags_t flags)
  {
  	int	retries = 0;
  	gfp_t	lflags = kmem_flags_convert(flags);
  	void	*ptr;
  
  	do {
  		ptr = krealloc(old, newsize, lflags);
  		if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
  			return ptr;
  		if (!(++retries % 100))
  			xfs_err(NULL,
  	"%s(%u) possible memory allocation deadlock size %zu in %s (mode:0x%x)",
  				current->comm, current->pid,
  				newsize, __func__, lflags);
  		congestion_wait(BLK_RW_ASYNC, HZ/50);
  	} while (1);
  }
  
  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,
  		"%s(%u) possible memory allocation deadlock in %s (mode:0x%x)",
  				current->comm, current->pid,
  				__func__, lflags);
  		congestion_wait(BLK_RW_ASYNC, HZ/50);
  	} while (1);
  }