fs/xfs/kmem.c

   1 /*
   2  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #include <linux/mm.h>
  19 #include <linux/highmem.h>
  20 #include <linux/slab.h>
  21 #include <linux/swap.h>
  22 #include <linux/blkdev.h>
  23 #include <linux/backing-dev.h>
  24 #include "kmem.h"
  25 #include "xfs_message.h"
  26
  27 void *
  28 kmem_alloc(size_t size, xfs_km_flags_t flags)
  29 {
  30         int     retries = 0;
  31         gfp_t   lflags = kmem_flags_convert(flags);
  32         void    *ptr;
  33
  34         do {
  35                 ptr = kmalloc(size, lflags);
  36                 if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
  37                         return ptr;
  38                 if (!(++retries % 100))
  39                         xfs_err(NULL,
  40         "%s(%u) possible memory allocation deadlock size %u in %s (mode:0x%x)",
  41                                 current->comm, current->pid,
  42                                 (unsigned int)size, __func__, lflags);
  43                 congestion_wait(BLK_RW_ASYNC, HZ/50);
  44         } while (1);
  45 }
  46
  47 void *
  48 kmem_zalloc_large(size_t size, xfs_km_flags_t flags)
  49 {
  50         unsigned noio_flag = 0;
  51         void    *ptr;
  52         gfp_t   lflags;
  53
  54         ptr = kmem_zalloc(size, flags | KM_MAYFAIL);
  55         if (ptr)
  56                 return ptr;
  57
  58         /*
  59          * __vmalloc() will allocate data pages and auxillary structures (e.g.
  60          * pagetables) with GFP_KERNEL, yet we may be under GFP_NOFS context
  61          * here. Hence we need to tell memory reclaim that we are in such a
  62          * context via PF_MEMALLOC_NOIO to prevent memory reclaim re-entering
  63          * the filesystem here and potentially deadlocking.
  64          */
  65         if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS))
  66                 noio_flag = memalloc_noio_save();
  67
  68         lflags = kmem_flags_convert(flags);
  69         ptr = __vmalloc(size, lflags | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL);
  70
  71         if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS))
  72                 memalloc_noio_restore(noio_flag);
  73
  74         return ptr;
  75 }
  76
  77 void *
  78 kmem_realloc(const void *ptr, size_t newsize, size_t oldsize,
  79              xfs_km_flags_t flags)
  80 {
  81         void    *new;
  82
  83         new = kmem_alloc(newsize, flags);
  84         if (ptr) {
  85                 if (new)
  86                         memcpy(new, ptr,
  87                                 ((oldsize < newsize) ? oldsize : newsize));
  88                 kmem_free(ptr);
  89         }
  90         return new;
  91 }
  92
  93 void *
  94 kmem_zone_alloc(kmem_zone_t *zone, xfs_km_flags_t flags)
  95 {
  96         int     retries = 0;
  97         gfp_t   lflags = kmem_flags_convert(flags);
  98         void    *ptr;
  99
 100         do {
 101                 ptr = kmem_cache_alloc(zone, lflags);
 102                 if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
 103                         return ptr;
 104                 if (!(++retries % 100))
 105                         xfs_err(NULL,
 106                 "%s(%u) possible memory allocation deadlock in %s (mode:0x%x)",
 107                                 current->comm, current->pid,
 108                                 __func__, lflags);
 109                 congestion_wait(BLK_RW_ASYNC, HZ/50);
 110         } while (1);
 111 }