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 2009 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #ifndef _SYS_TXG_H 27 #define _SYS_TXG_H 28 29 #include <sys/spa.h> 30 #include <sys/zfs_context.h> 31 32 #ifdef __cplusplus 33 extern "C" { 34 #endif 35 36 #define TXG_CONCURRENT_STATES 3 /* open, quiescing, syncing */ 37 #define TXG_SIZE 4 /* next power of 2 */ 38 #define TXG_MASK (TXG_SIZE - 1) /* mask for size */ 39 #define TXG_INITIAL TXG_SIZE /* initial txg */ 40 #define TXG_IDX (txg & TXG_MASK) 41 42 #define TXG_WAIT 1ULL 43 #define TXG_NOWAIT 2ULL 44 45 typedef struct tx_cpu tx_cpu_t; 46 47 typedef struct txg_handle { 48 tx_cpu_t *th_cpu; 49 uint64_t th_txg; 50 } txg_handle_t; 51 52 typedef struct txg_node { 53 struct txg_node *tn_next[TXG_SIZE]; 54 uint8_t tn_member[TXG_SIZE]; 55 } txg_node_t; 56 57 typedef struct txg_list { 58 kmutex_t tl_lock; 59 size_t tl_offset; 60 txg_node_t *tl_head[TXG_SIZE]; 61 } txg_list_t; 62 63 struct dsl_pool; 64 65 extern void txg_init(struct dsl_pool *dp, uint64_t txg); 66 extern void txg_fini(struct dsl_pool *dp); 67 extern void txg_sync_start(struct dsl_pool *dp); 68 extern void txg_sync_stop(struct dsl_pool *dp); 69 extern uint64_t txg_hold_open(struct dsl_pool *dp, txg_handle_t *txghp); 70 extern void txg_rele_to_quiesce(txg_handle_t *txghp); 71 extern void txg_rele_to_sync(txg_handle_t *txghp); 72 extern void txg_register_callbacks(txg_handle_t *txghp, list_t *tx_callbacks); 73 extern void txg_suspend(struct dsl_pool *dp); 74 extern void txg_resume(struct dsl_pool *dp); 75 76 /* 77 * Delay the caller by the specified number of ticks or until 78 * the txg closes (whichever comes first). This is intended 79 * to be used to throttle writers when the system nears its 80 * capacity. 81 */ 82 extern void txg_delay(struct dsl_pool *dp, uint64_t txg, int ticks); 83 84 /* 85 * Wait until the given transaction group has finished syncing. 86 * Try to make this happen as soon as possible (eg. kick off any 87 * necessary syncs immediately). If txg==0, wait for the currently open 88 * txg to finish syncing. 89 */ 90 extern void txg_wait_synced(struct dsl_pool *dp, uint64_t txg); 91 92 /* 93 * Wait until the given transaction group, or one after it, is 94 * the open transaction group. Try to make this happen as soon 95 * as possible (eg. kick off any necessary syncs immediately). 96 * If txg == 0, wait for the next open txg. 97 */ 98 extern void txg_wait_open(struct dsl_pool *dp, uint64_t txg); 99 100 /* 101 * Returns TRUE if we are "backed up" waiting for the syncing 102 * transaction to complete; otherwise returns FALSE. 103 */ 104 extern boolean_t txg_stalled(struct dsl_pool *dp); 105 106 /* returns TRUE if someone is waiting for the next txg to sync */ 107 extern boolean_t txg_sync_waiting(struct dsl_pool *dp); 108 109 /* 110 * Per-txg object lists. 111 */ 112 113 #define TXG_CLEAN(txg) ((txg) - 1) 114 115 extern void txg_list_create(txg_list_t *tl, size_t offset); 116 extern void txg_list_destroy(txg_list_t *tl); 117 extern int txg_list_empty(txg_list_t *tl, uint64_t txg); 118 extern int txg_list_add(txg_list_t *tl, void *p, uint64_t txg); 119 extern void *txg_list_remove(txg_list_t *tl, uint64_t txg); 120 extern void *txg_list_remove_this(txg_list_t *tl, void *p, uint64_t txg); 121 extern int txg_list_member(txg_list_t *tl, void *p, uint64_t txg); 122 extern void *txg_list_head(txg_list_t *tl, uint64_t txg); 123 extern void *txg_list_next(txg_list_t *tl, void *p, uint64_t txg); 124 125 #ifdef __cplusplus 126 } 127 #endif 128 129 #endif /* _SYS_TXG_H */ 130