sys/vfs/hammer/hammer_transaction.c

   1 /*
   2  * Copyright (c) 2007-2008 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $DragonFly: src/sys/vfs/hammer/hammer_transaction.c,v 1.17 2008/06/10 08:51:02 dillon Exp $
  35  */
  36
  37 #include "hammer.h"
  38
  39 static hammer_tid_t hammer_alloc_tid(hammer_transaction_t trans, int count);
  40
  41
  42 /*
  43  * Start a standard transaction.
  44  */
  45 void
  46 hammer_start_transaction(struct hammer_transaction *trans,
  47                          struct hammer_mount *hmp)
  48 {
  49         int error;
  50
  51         trans->type = HAMMER_TRANS_STD;
  52         trans->hmp = hmp;
  53         trans->rootvol = hammer_get_root_volume(hmp, &error);
  54         KKASSERT(error == 0);
  55         trans->tid = 0;
  56         trans->time = hammer_alloc_tid(trans, 1);
  57         trans->sync_lock_refs = 0;
  58 }
  59
  60 /*
  61  * Start a simple read-only transaction.  This will not stall.
  62  */
  63 void
  64 hammer_simple_transaction(struct hammer_transaction *trans,
  65                           struct hammer_mount *hmp)
  66 {
  67         int error;
  68
  69         trans->type = HAMMER_TRANS_RO;
  70         trans->hmp = hmp;
  71         trans->rootvol = hammer_get_root_volume(hmp, &error);
  72         KKASSERT(error == 0);
  73         trans->tid = 0;
  74         trans->time = hammer_alloc_tid(trans, 1);
  75         trans->sync_lock_refs = 0;
  76 }
  77
  78 /*
  79  * Start a transaction using a particular TID.  Used by the sync code.
  80  * This does not stall.
  81  *
  82  * This routine may only be called from the flusher thread.  We predispose
  83  * sync_lock_refs, implying serialization against the synchronization stage
  84  * (which the flusher is responsible for).
  85  */
  86 void
  87 hammer_start_transaction_fls(struct hammer_transaction *trans,
  88                              struct hammer_mount *hmp)
  89 {
  90         int error;
  91
  92         bzero(trans, sizeof(*trans));
  93
  94         trans->type = HAMMER_TRANS_FLS;
  95         trans->hmp = hmp;
  96         trans->rootvol = hammer_get_root_volume(hmp, &error);
  97         KKASSERT(error == 0);
  98         trans->tid = hammer_alloc_tid(trans, 1);
  99         trans->time = trans->tid;
 100         trans->sync_lock_refs = 1;
 101 }
 102
 103 void
 104 hammer_done_transaction(struct hammer_transaction *trans)
 105 {
 106         int expected_lock_refs;
 107
 108         hammer_rel_volume(trans->rootvol, 0);
 109         trans->rootvol = NULL;
 110         expected_lock_refs = (trans->type == HAMMER_TRANS_FLS) ? 1 : 0;
 111         KKASSERT(trans->sync_lock_refs == expected_lock_refs);
 112         trans->sync_lock_refs = 0;
 113 }
 114
 115 /*
 116  * Note: Successive transaction ids must be at least 2 apart so the
 117  * B-Tree code can make a separator that does not match either the
 118  * left or right hand sides.
 119  */
 120 static hammer_tid_t
 121 hammer_alloc_tid(hammer_transaction_t trans, int count)
 122 {
 123         struct timespec ts;
 124         hammer_tid_t tid;
 125
 126         getnanotime(&ts);
 127         tid = ts.tv_sec * 1000000000LL + ts.tv_nsec;
 128         if (tid < trans->hmp->next_tid)
 129                 tid = trans->hmp->next_tid;
 130         if (tid >= 0xFFFFFFFFFFFFF000ULL)
 131                 panic("hammer_start_transaction: Ran out of TIDs!");
 132         trans->hmp->next_tid = tid + count * 2;
 133         if (hammer_debug_tid) {
 134                 kprintf("alloc_tid %016llx (0x%08x)\n",
 135                         tid, (int)(tid / 1000000000LL));
 136         }
 137         return(tid);
 138 }
 139
 140 /*
 141  * Allocate an object id
 142  */
 143 hammer_tid_t
 144 hammer_alloc_objid(hammer_transaction_t trans, hammer_inode_t dip)
 145 {
 146         hammer_objid_cache_t ocp;
 147         hammer_tid_t tid;
 148
 149         while ((ocp = dip->objid_cache) == NULL) {
 150                 if (trans->hmp->objid_cache_count < OBJID_CACHE_SIZE) {
 151                         ocp = kmalloc(sizeof(*ocp), M_HAMMER, M_WAITOK|M_ZERO);
 152                         ocp->next_tid = hammer_alloc_tid(trans,
 153                                                          OBJID_CACHE_BULK);
 154                         ocp->count = OBJID_CACHE_BULK;
 155                         TAILQ_INSERT_HEAD(&trans->hmp->objid_cache_list, ocp,
 156                                           entry);
 157                         ++trans->hmp->objid_cache_count;
 158                         /* may have blocked, recheck */
 159                         if (dip->objid_cache == NULL) {
 160                                 dip->objid_cache = ocp;
 161                                 ocp->dip = dip;
 162                         }
 163                 } else {
 164                         ocp = TAILQ_FIRST(&trans->hmp->objid_cache_list);
 165                         if (ocp->dip)
 166                                 ocp->dip->objid_cache = NULL;
 167                         dip->objid_cache = ocp;
 168                         ocp->dip = dip;
 169                 }
 170         }
 171         TAILQ_REMOVE(&trans->hmp->objid_cache_list, ocp, entry);
 172         tid = ocp->next_tid;
 173         ocp->next_tid += 2;
 174         if (--ocp->count == 0) {
 175                 dip->objid_cache = NULL;
 176                 --trans->hmp->objid_cache_count;
 177                 ocp->dip = NULL;
 178                 kfree(ocp, M_HAMMER);
 179         } else {
 180                 TAILQ_INSERT_TAIL(&trans->hmp->objid_cache_list, ocp, entry);
 181         }
 182         return(tid);
 183 }
 184
 185 void
 186 hammer_clear_objid(hammer_inode_t dip)
 187 {
 188         hammer_objid_cache_t ocp;
 189
 190         if ((ocp = dip->objid_cache) != NULL) {
 191                 dip->objid_cache = NULL;
 192                 ocp->dip = NULL;
 193                 TAILQ_REMOVE(&dip->hmp->objid_cache_list, ocp, entry);
 194                 TAILQ_INSERT_HEAD(&dip->hmp->objid_cache_list, ocp, entry);
 195         }
 196 }
 197
 198 void
 199 hammer_destroy_objid_cache(hammer_mount_t hmp)
 200 {
 201         hammer_objid_cache_t ocp;
 202
 203         while ((ocp = TAILQ_FIRST(&hmp->objid_cache_list)) != NULL) {
 204                 TAILQ_REMOVE(&hmp->objid_cache_list, ocp, entry);
 205                 kfree(ocp, M_HAMMER);
 206         }
 207 }
 208