LXR linux/fs/xfs/kmem.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   4 * All Rights Reserved.
   5 */
   6#include <linux/sched/mm.h>
   7#include <linux/backing-dev.h>
   8#include "kmem.h"
   9#include "xfs_message.h"
  10
  11void *
  12kmem_alloc(size_t size, xfs_km_flags_t flags)
  13{
  14        int     retries = 0;
  15        gfp_t   lflags = kmem_flags_convert(flags);
  16        void    *ptr;
  17
  18        do {
  19                ptr = kmalloc(size, lflags);
  20                if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
  21                        return ptr;
  22                if (!(++retries % 100))
  23                        xfs_err(NULL,
  24        "%s(%u) possible memory allocation deadlock size %u in %s (mode:0x%x)",
  25                                current->comm, current->pid,
  26                                (unsigned int)size, __func__, lflags);
  27                congestion_wait(BLK_RW_ASYNC, HZ/50);
  28        } while (1);
  29}
  30
  31void *
  32kmem_alloc_large(size_t size, xfs_km_flags_t flags)
  33{
  34        unsigned nofs_flag = 0;
  35        void    *ptr;
  36        gfp_t   lflags;
  37
  38        ptr = kmem_alloc(size, flags | KM_MAYFAIL);
  39        if (ptr)
  40                return ptr;
  41
  42        /*
  43         * __vmalloc() will allocate data pages and auxillary structures (e.g.
  44         * pagetables) with GFP_KERNEL, yet we may be under GFP_NOFS context
  45         * here. Hence we need to tell memory reclaim that we are in such a
  46         * context via PF_MEMALLOC_NOFS to prevent memory reclaim re-entering
  47         * the filesystem here and potentially deadlocking.
  48         */
  49        if (flags & KM_NOFS)
  50                nofs_flag = memalloc_nofs_save();
  51
  52        lflags = kmem_flags_convert(flags);
  53        ptr = __vmalloc(size, lflags, PAGE_KERNEL);
  54
  55        if (flags & KM_NOFS)
  56                memalloc_nofs_restore(nofs_flag);
  57
  58        return ptr;
  59}
  60
  61void *
  62kmem_realloc(const void *old, size_t newsize, xfs_km_flags_t flags)
  63{
  64        int     retries = 0;
  65        gfp_t   lflags = kmem_flags_convert(flags);
  66        void    *ptr;
  67
  68        do {
  69                ptr = krealloc(old, newsize, lflags);
  70                if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
  71                        return ptr;
  72                if (!(++retries % 100))
  73                        xfs_err(NULL,
  74        "%s(%u) possible memory allocation deadlock size %zu in %s (mode:0x%x)",
  75                                current->comm, current->pid,
  76                                newsize, __func__, lflags);
  77                congestion_wait(BLK_RW_ASYNC, HZ/50);
  78        } while (1);
  79}
  80
  81void *
  82kmem_zone_alloc(kmem_zone_t *zone, xfs_km_flags_t flags)
  83{
  84        int     retries = 0;
  85        gfp_t   lflags = kmem_flags_convert(flags);
  86        void    *ptr;
  87
  88        do {
  89                ptr = kmem_cache_alloc(zone, lflags);
  90                if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
  91                        return ptr;
  92                if (!(++retries % 100))
  93                        xfs_err(NULL,
  94                "%s(%u) possible memory allocation deadlock in %s (mode:0x%x)",
  95                                current->comm, current->pid,
  96                                __func__, lflags);
  97                congestion_wait(BLK_RW_ASYNC, HZ/50);
  98        } while (1);
  99}
 100