include/sys/kmem.h

   1 /*
   2  *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
   3  *  Copyright (C) 2007 The Regents of the University of California.
   4  *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
   5  *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
   6  *  UCRL-CODE-235197
   7  *
   8  *  This file is part of the SPL, Solaris Porting Layer.
   9  *  For details, see <http://zfsonlinux.org/>.
  10  *
  11  *  The SPL is free software; you can redistribute it and/or modify it
  12  *  under the terms of the GNU General Public License as published by the
  13  *  Free Software Foundation; either version 2 of the License, or (at your
  14  *  option) any later version.
  15  *
  16  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
  17  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  18  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  19  *  for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License along
  22  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
  23  */
  24
  25 #ifndef _SPL_KMEM_H
  26 #define _SPL_KMEM_H
  27
  28 #include <sys/debug.h>
  29 #include <linux/slab.h>
  30 #include <linux/sched.h>
  31
  32 extern int kmem_debugging(void);
  33 extern char *kmem_vasprintf(const char *fmt, va_list ap);
  34 extern char *kmem_asprintf(const char *fmt, ...);
  35 extern char *strdup(const char *str);
  36 extern void strfree(char *str);
  37
  38 /*
  39  * Memory allocation interfaces
  40  */
  41 #define KM_SLEEP        0x0000  /* can block for memory; success guaranteed */
  42 #define KM_NOSLEEP      0x0001  /* cannot block for memory; may fail */
  43 #define KM_PUSHPAGE     0x0004  /* can block for memory; may use reserve */
  44 #define KM_ZERO         0x1000  /* zero the allocation */
  45 #define KM_VMEM         0x2000  /* caller is vmem_* wrapper */
  46
  47 #define KM_PUBLIC_MASK  (KM_SLEEP | KM_NOSLEEP | KM_PUSHPAGE)
  48
  49 static int spl_fstrans_check(void);
  50
  51 /*
  52  * Convert a KM_* flags mask to its Linux GFP_* counterpart.  The conversion
  53  * function is context aware which means that KM_SLEEP allocations can be
  54  * safely used in syncing contexts which have set PF_FSTRANS.
  55  */
  56 static inline gfp_t
  57 kmem_flags_convert(int flags)
  58 {
  59         gfp_t lflags = __GFP_NOWARN | __GFP_COMP;
  60
  61         if (flags & KM_NOSLEEP) {
  62                 lflags |= GFP_ATOMIC | __GFP_NORETRY;
  63         } else {
  64                 lflags |= GFP_KERNEL;
  65                 if (spl_fstrans_check())
  66                         lflags &= ~(__GFP_IO|__GFP_FS);
  67         }
  68
  69         if (flags & KM_PUSHPAGE)
  70                 lflags |= __GFP_HIGH;
  71
  72         if (flags & KM_ZERO)
  73                 lflags |= __GFP_ZERO;
  74
  75         return (lflags);
  76 }
  77
  78 typedef struct {
  79         struct task_struct *fstrans_thread;
  80         unsigned int saved_flags;
  81 } fstrans_cookie_t;
  82
  83 /*
  84  * Introduced in Linux 3.9, however this cannot be solely relied on before
  85  * Linux 3.18 as it doesn't turn off __GFP_FS as it should.
  86  */
  87 #ifdef PF_MEMALLOC_NOIO
  88 #define __SPL_PF_MEMALLOC_NOIO (PF_MEMALLOC_NOIO)
  89 #else
  90 #define __SPL_PF_MEMALLOC_NOIO (0)
  91 #endif
  92
  93 /*
  94  * PF_FSTRANS is removed from Linux 4.12
  95  */
  96 #ifdef PF_FSTRANS
  97 #define __SPL_PF_FSTRANS (PF_FSTRANS)
  98 #else
  99 #define __SPL_PF_FSTRANS (0)
 100 #endif
 101
 102 #define SPL_FSTRANS (__SPL_PF_FSTRANS|__SPL_PF_MEMALLOC_NOIO)
 103
 104 static inline fstrans_cookie_t
 105 spl_fstrans_mark(void)
 106 {
 107         fstrans_cookie_t cookie;
 108
 109         BUILD_BUG_ON(SPL_FSTRANS == 0);
 110
 111         cookie.fstrans_thread = current;
 112         cookie.saved_flags = current->flags & SPL_FSTRANS;
 113         current->flags |= SPL_FSTRANS;
 114
 115         return (cookie);
 116 }
 117
 118 static inline void
 119 spl_fstrans_unmark(fstrans_cookie_t cookie)
 120 {
 121         ASSERT3P(cookie.fstrans_thread, ==, current);
 122         ASSERT((current->flags & SPL_FSTRANS) == SPL_FSTRANS);
 123
 124         current->flags &= ~SPL_FSTRANS;
 125         current->flags |= cookie.saved_flags;
 126 }
 127
 128 static inline int
 129 spl_fstrans_check(void)
 130 {
 131         return (current->flags & SPL_FSTRANS);
 132 }
 133
 134 /*
 135  * specifically used to check PF_FSTRANS flag, cannot be relied on for
 136  * checking spl_fstrans_mark().
 137  */
 138 static inline int
 139 __spl_pf_fstrans_check(void)
 140 {
 141         return (current->flags & __SPL_PF_FSTRANS);
 142 }
 143
 144 #ifdef HAVE_ATOMIC64_T
 145 #define kmem_alloc_used_add(size)       atomic64_add(size, &kmem_alloc_used)
 146 #define kmem_alloc_used_sub(size)       atomic64_sub(size, &kmem_alloc_used)
 147 #define kmem_alloc_used_read()          atomic64_read(&kmem_alloc_used)
 148 #define kmem_alloc_used_set(size)       atomic64_set(&kmem_alloc_used, size)
 149 extern atomic64_t kmem_alloc_used;
 150 extern unsigned long long kmem_alloc_max;
 151 #else  /* HAVE_ATOMIC64_T */
 152 #define kmem_alloc_used_add(size)       atomic_add(size, &kmem_alloc_used)
 153 #define kmem_alloc_used_sub(size)       atomic_sub(size, &kmem_alloc_used)
 154 #define kmem_alloc_used_read()          atomic_read(&kmem_alloc_used)
 155 #define kmem_alloc_used_set(size)       atomic_set(&kmem_alloc_used, size)
 156 extern atomic_t kmem_alloc_used;
 157 extern unsigned long long kmem_alloc_max;
 158 #endif /* HAVE_ATOMIC64_T */
 159
 160 extern unsigned int spl_kmem_alloc_warn;
 161 extern unsigned int spl_kmem_alloc_max;
 162
 163 #define kmem_alloc(sz, fl)      spl_kmem_alloc((sz), (fl), __func__, __LINE__)
 164 #define kmem_zalloc(sz, fl)     spl_kmem_zalloc((sz), (fl), __func__, __LINE__)
 165 #define kmem_free(ptr, sz)      spl_kmem_free((ptr), (sz))
 166
 167 extern void *spl_kmem_alloc(size_t sz, int fl, const char *func, int line);
 168 extern void *spl_kmem_zalloc(size_t sz, int fl, const char *func, int line);
 169 extern void spl_kmem_free(const void *ptr, size_t sz);
 170
 171 /*
 172  * The following functions are only available for internal use.
 173  */
 174 extern void *spl_kmem_alloc_impl(size_t size, int flags, int node);
 175 extern void *spl_kmem_alloc_debug(size_t size, int flags, int node);
 176 extern void *spl_kmem_alloc_track(size_t size, int flags,
 177     const char *func, int line, int node);
 178 extern void spl_kmem_free_impl(const void *buf, size_t size);
 179 extern void spl_kmem_free_debug(const void *buf, size_t size);
 180 extern void spl_kmem_free_track(const void *buf, size_t size);
 181
 182 extern int spl_kmem_init(void);
 183 extern void spl_kmem_fini(void);
 184
 185 #endif  /* _SPL_KMEM_H */