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/sched/mm.h>
  20 #include <linux/highmem.h>
  21 #include <linux/slab.h>
  22 #include <linux/swap.h>
  23 #include <linux/blkdev.h>
  24 #include <linux/backing-dev.h>
  25 #include "kmem.h"
  26 #include "xfs_message.h"
  27
  28 void *
  29 kmem_alloc(size_t size, xfs_km_flags_t flags)
  30 {
  31         int     retries = 0;
  32         gfp_t   lflags = kmem_flags_convert(flags);
  33         void    *ptr;
  34
  35         do {
  36                 ptr = kmalloc(size, lflags);
  37                 if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
  38                         return ptr;
  39                 if (!(++retries % 100))
  40                         xfs_err(NULL,
  41         "%s(%u) possible memory allocation deadlock size %u in %s (mode:0x%x)",
  42                                 current->comm, current->pid,
  43                                 (unsigned int)size, __func__, lflags);
  44                 congestion_wait(BLK_RW_ASYNC, HZ/50);
  45         } while (1);
  46 }
  47
  48 void *
  49 kmem_zalloc_large(size_t size, xfs_km_flags_t flags)
  50 {
  51         unsigned nofs_flag = 0;
  52         void    *ptr;
  53         gfp_t   lflags;
  54
  55         ptr = kmem_zalloc(size, flags | KM_MAYFAIL);
  56         if (ptr)
  57                 return ptr;
  58
  59         /*
  60          * __vmalloc() will allocate data pages and auxillary structures (e.g.
  61          * pagetables) with GFP_KERNEL, yet we may be under GFP_NOFS context
  62          * here. Hence we need to tell memory reclaim that we are in such a
  63          * context via PF_MEMALLOC_NOFS to prevent memory reclaim re-entering
  64          * the filesystem here and potentially deadlocking.
  65          */
  66         if (flags & KM_NOFS)
  67                 nofs_flag = memalloc_nofs_save();
  68
  69         lflags = kmem_flags_convert(flags);
  70         ptr = __vmalloc(size, lflags | __GFP_ZERO, PAGE_KERNEL);
  71
  72         if (flags & KM_NOFS)
  73                 memalloc_nofs_restore(nofs_flag);
  74
  75         return ptr;
  76 }
  77
  78 void *
  79 kmem_realloc(const void *old, size_t newsize, xfs_km_flags_t flags)
  80 {
  81         int     retries = 0;
  82         gfp_t   lflags = kmem_flags_convert(flags);
  83         void    *ptr;
  84
  85         do {
  86                 ptr = krealloc(old, newsize, lflags);
  87                 if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
  88                         return ptr;
  89                 if (!(++retries % 100))
  90                         xfs_err(NULL,
  91         "%s(%u) possible memory allocation deadlock size %zu in %s (mode:0x%x)",
  92                                 current->comm, current->pid,
  93                                 newsize, __func__, lflags);
  94                 congestion_wait(BLK_RW_ASYNC, HZ/50);
  95         } while (1);
  96 }
  97
  98 void *
  99 kmem_zone_alloc(kmem_zone_t *zone, xfs_km_flags_t flags)
 100 {
 101         int     retries = 0;
 102         gfp_t   lflags = kmem_flags_convert(flags);
 103         void    *ptr;
 104
 105         do {
 106                 ptr = kmem_cache_alloc(zone, lflags);
 107                 if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
 108                         return ptr;
 109                 if (!(++retries % 100))
 110                         xfs_err(NULL,
 111                 "%s(%u) possible memory allocation deadlock in %s (mode:0x%x)",
 112                                 current->comm, current->pid,
 113                                 __func__, lflags);
 114                 congestion_wait(BLK_RW_ASYNC, HZ/50);
 115         } while (1);
 116 }