include/sys/txg.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25 /*
  26  * Copyright (c) 2012 by Delphix. All rights reserved.
  27  */
  28
  29 #ifndef _SYS_TXG_H
  30 #define _SYS_TXG_H
  31
  32 #include <sys/spa.h>
  33 #include <sys/zfs_context.h>
  34
  35 #ifdef  __cplusplus
  36 extern "C" {
  37 #endif
  38
  39 #define TXG_CONCURRENT_STATES   3       /* open, quiescing, syncing     */
  40 #define TXG_SIZE                4               /* next power of 2      */
  41 #define TXG_MASK                (TXG_SIZE - 1)  /* mask for size        */
  42 #define TXG_INITIAL             TXG_SIZE        /* initial txg          */
  43 #define TXG_IDX                 (txg & TXG_MASK)
  44
  45 /* Number of txgs worth of frees we defer adding to in-core spacemaps */
  46 #define TXG_DEFER_SIZE          2
  47
  48 #define TXG_WAIT                1ULL
  49 #define TXG_NOWAIT              2ULL
  50
  51 typedef struct tx_cpu tx_cpu_t;
  52
  53 typedef struct txg_handle {
  54         tx_cpu_t        *th_cpu;
  55         uint64_t        th_txg;
  56 } txg_handle_t;
  57
  58 typedef struct txg_node {
  59         struct txg_node *tn_next[TXG_SIZE];
  60         uint8_t         tn_member[TXG_SIZE];
  61 } txg_node_t;
  62
  63 typedef struct txg_list {
  64         kmutex_t        tl_lock;
  65         size_t          tl_offset;
  66         txg_node_t      *tl_head[TXG_SIZE];
  67 } txg_list_t;
  68
  69 struct dsl_pool;
  70
  71 extern void txg_init(struct dsl_pool *dp, uint64_t txg);
  72 extern void txg_fini(struct dsl_pool *dp);
  73 extern void txg_sync_start(struct dsl_pool *dp);
  74 extern void txg_sync_stop(struct dsl_pool *dp);
  75 extern uint64_t txg_hold_open(struct dsl_pool *dp, txg_handle_t *txghp);
  76 extern void txg_rele_to_quiesce(txg_handle_t *txghp);
  77 extern void txg_rele_to_sync(txg_handle_t *txghp);
  78 extern void txg_register_callbacks(txg_handle_t *txghp, list_t *tx_callbacks);
  79
  80 /*
  81  * Delay the caller by the specified number of ticks or until
  82  * the txg closes (whichever comes first).  This is intended
  83  * to be used to throttle writers when the system nears its
  84  * capacity.
  85  */
  86 extern void txg_delay(struct dsl_pool *dp, uint64_t txg, int ticks);
  87
  88 /*
  89  * Wait until the given transaction group has finished syncing.
  90  * Try to make this happen as soon as possible (eg. kick off any
  91  * necessary syncs immediately).  If txg==0, wait for the currently open
  92  * txg to finish syncing.
  93  */
  94 extern void txg_wait_synced(struct dsl_pool *dp, uint64_t txg);
  95
  96 /*
  97  * Wait until the given transaction group, or one after it, is
  98  * the open transaction group.  Try to make this happen as soon
  99  * as possible (eg. kick off any necessary syncs immediately).
 100  * If txg == 0, wait for the next open txg.
 101  */
 102 extern void txg_wait_open(struct dsl_pool *dp, uint64_t txg);
 103
 104 /*
 105  * Returns TRUE if we are "backed up" waiting for the syncing
 106  * transaction to complete; otherwise returns FALSE.
 107  */
 108 extern boolean_t txg_stalled(struct dsl_pool *dp);
 109
 110 /* returns TRUE if someone is waiting for the next txg to sync */
 111 extern boolean_t txg_sync_waiting(struct dsl_pool *dp);
 112
 113 /*
 114  * Wait for pending commit callbacks of already-synced transactions to finish
 115  * processing.
 116  */
 117 extern void txg_wait_callbacks(struct dsl_pool *dp);
 118
 119 /*
 120  * Per-txg object lists.
 121  */
 122
 123 #define TXG_CLEAN(txg)  ((txg) - 1)
 124
 125 extern void txg_list_create(txg_list_t *tl, size_t offset);
 126 extern void txg_list_destroy(txg_list_t *tl);
 127 extern boolean_t txg_list_empty(txg_list_t *tl, uint64_t txg);
 128 extern int txg_list_add(txg_list_t *tl, void *p, uint64_t txg);
 129 extern int txg_list_add_tail(txg_list_t *tl, void *p, uint64_t txg);
 130 extern void *txg_list_remove(txg_list_t *tl, uint64_t txg);
 131 extern void *txg_list_remove_this(txg_list_t *tl, void *p, uint64_t txg);
 132 extern int txg_list_member(txg_list_t *tl, void *p, uint64_t txg);
 133 extern void *txg_list_head(txg_list_t *tl, uint64_t txg);
 134 extern void *txg_list_next(txg_list_t *tl, void *p, uint64_t txg);
 135
 136 /* Global tuning */
 137 extern int zfs_txg_timeout;
 138
 139 #ifdef  __cplusplus
 140 }
 141 #endif
 142
 143 #endif  /* _SYS_TXG_H */