lustre/obdclass/lustre_handles.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * Copyright (C) 2002 Cluster File Systems, Inc.
   5  *   Author: Phil Schwan <phil@clusterfs.com>
   6  *
   7  *   This file is part of Lustre, http://www.lustre.org/
   8  *
   9  *   Lustre is free software; you can redistribute it and/or
  10  *   modify it under the terms of version 2 of the GNU General Public
  11  *   License as published by the Free Software Foundation.
  12  *
  13  *   Lustre is distributed in the hope that it will be useful,
  14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *   GNU General Public License for more details.
  17  *
  18  *   You should have received a copy of the GNU General Public License
  19  *   along with Lustre; if not, write to the Free Software
  20  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  */
  22
  23 #define DEBUG_SUBSYSTEM S_CLASS
  24 #ifdef __KERNEL__
  25 # include <linux/types.h>
  26 # include <linux/random.h>
  27 #else
  28 # include <liblustre.h>
  29 #endif
  30
  31 #include <linux/obd_support.h>
  32 #include <linux/lustre_handles.h>
  33
  34 static spinlock_t handle_lock = SPIN_LOCK_UNLOCKED;
  35 static __u64 handle_base;
  36 #define HANDLE_INCR 7
  37 static struct list_head *handle_hash = NULL;
  38 static int handle_count = 0;
  39
  40 #define HANDLE_HASH_SIZE (1 << 14)
  41 #define HANDLE_HASH_MASK (HANDLE_HASH_SIZE - 1)
  42
  43 void class_handle_hash(struct portals_handle *h, portals_handle_addref_cb cb)
  44 {
  45         struct list_head *bucket;
  46         ENTRY;
  47
  48         LASSERT(h != NULL);
  49         LASSERT(list_empty(&h->h_link));
  50
  51         spin_lock(&handle_lock);
  52         h->h_cookie = handle_base;
  53         handle_base += HANDLE_INCR;
  54         spin_unlock(&handle_lock);
  55
  56         h->h_addref = cb;
  57         bucket = handle_hash + (h->h_cookie & HANDLE_HASH_MASK);
  58         CDEBUG(D_INFO, "adding object %p with handle "LPX64" to hash\n",
  59                h, h->h_cookie);
  60
  61         spin_lock(&handle_lock);
  62         list_add(&h->h_link, bucket);
  63         handle_count++;
  64         spin_unlock(&handle_lock);
  65         EXIT;
  66 }
  67
  68 static void class_handle_unhash_nolock(struct portals_handle *h)
  69 {
  70         if (list_empty(&h->h_link)) {
  71                 CERROR("removing an already-removed handle ("LPX64")\n",
  72                        h->h_cookie);
  73                 return;
  74         }
  75
  76         CDEBUG(D_INFO, "removing object %p with handle "LPX64" from hash\n",
  77                h, h->h_cookie);
  78
  79         handle_count--;
  80         list_del_init(&h->h_link);
  81 }
  82
  83 void class_handle_unhash(struct portals_handle *h)
  84 {
  85         spin_lock(&handle_lock);
  86         class_handle_unhash_nolock(h);
  87         spin_unlock(&handle_lock);
  88 }
  89
  90 void *class_handle2object(__u64 cookie)
  91 {
  92         struct list_head *bucket, *tmp;
  93         void *retval = NULL;
  94         ENTRY;
  95
  96         LASSERT(handle_hash != NULL);
  97
  98         bucket = handle_hash + (cookie & HANDLE_HASH_MASK);
  99
 100         spin_lock(&handle_lock);
 101         list_for_each(tmp, bucket) {
 102                 struct portals_handle *h;
 103                 h = list_entry(tmp, struct portals_handle, h_link);
 104
 105                 if (h->h_cookie == cookie) {
 106                         h->h_addref(h);
 107                         retval = h;
 108                         break;
 109                 }
 110         }
 111         spin_unlock(&handle_lock);
 112
 113         RETURN(retval);
 114 }
 115
 116 int class_handle_init(void)
 117 {
 118         struct list_head *bucket;
 119
 120         LASSERT(handle_hash == NULL);
 121
 122         OBD_VMALLOC(handle_hash, sizeof(*handle_hash) * HANDLE_HASH_SIZE);
 123         if (handle_hash == NULL)
 124                 return -ENOMEM;
 125
 126         for (bucket = handle_hash + HANDLE_HASH_SIZE - 1; bucket >= handle_hash;
 127              bucket--)
 128                 INIT_LIST_HEAD(bucket);
 129
 130         get_random_bytes(&handle_base, sizeof(handle_base));
 131         LASSERT(handle_base != 0ULL);
 132
 133         return 0;
 134 }
 135
 136 static void cleanup_all_handles(void)
 137 {
 138         int i;
 139
 140         spin_lock(&handle_lock);
 141         for (i = 0; i < HANDLE_HASH_SIZE; i++) {
 142                 struct list_head *tmp, *pos;
 143                 list_for_each_safe(tmp, pos, &(handle_hash[i])) {
 144                         struct portals_handle *h;
 145                         h = list_entry(tmp, struct portals_handle, h_link);
 146
 147                         CERROR("force clean handle "LPX64" addr %p addref %p\n",
 148                                h->h_cookie, h, h->h_addref);
 149
 150                         class_handle_unhash_nolock(h);
 151                 }
 152         }
 153         spin_unlock(&handle_lock);
 154 }
 155
 156 void class_handle_cleanup(void)
 157 {
 158         LASSERT(handle_hash != NULL);
 159
 160         if (handle_count != 0) {
 161                 CERROR("handle_count at cleanup: %d\n", handle_count);
 162                 cleanup_all_handles();
 163         }
 164
 165         OBD_VFREE(handle_hash, sizeof(*handle_hash) * HANDLE_HASH_SIZE);
 166         handle_hash = NULL;
 167
 168         if (handle_count)
 169                 CERROR("leaked %d handles\n", handle_count);
 170 }