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 2008 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 #pragma ident "%Z%%M% %I% %E% SMI" 30 31 #include <sys/spa.h> 32 #include <sys/zfs_context.h> 33 34 #ifdef __cplusplus 35 extern "C" { 36 #endif 37 38 #define TXG_CONCURRENT_STATES 3 /* open, quiescing, syncing */ 39 #define TXG_SIZE 4 /* next power of 2 */ 40 #define TXG_MASK (TXG_SIZE - 1) /* mask for size */ 41 #define TXG_INITIAL TXG_SIZE /* initial txg */ 42 #define TXG_IDX (txg & TXG_MASK) 43 44 #define TXG_WAIT 1ULL 45 #define TXG_NOWAIT 2ULL 46 47 typedef struct tx_cpu tx_cpu_t; 48 49 typedef struct txg_handle { 50 tx_cpu_t *th_cpu; 51 uint64_t th_txg; 52 } txg_handle_t; 53 54 typedef struct txg_node { 55 struct txg_node *tn_next[TXG_SIZE]; 56 uint8_t tn_member[TXG_SIZE]; 57 } txg_node_t; 58 59 typedef struct txg_list { 60 kmutex_t tl_lock; 61 size_t tl_offset; 62 txg_node_t *tl_head[TXG_SIZE]; 63 } txg_list_t; 64 65 struct dsl_pool; 66 67 extern void txg_init(struct dsl_pool *dp, uint64_t txg); 68 extern void txg_fini(struct dsl_pool *dp); 69 extern void txg_sync_start(struct dsl_pool *dp); 70 extern void txg_sync_stop(struct dsl_pool *dp); 71 extern uint64_t txg_hold_open(struct dsl_pool *dp, txg_handle_t *txghp); 72 extern void txg_rele_to_quiesce(txg_handle_t *txghp); 73 extern void txg_rele_to_sync(txg_handle_t *txghp); 74 extern void txg_suspend(struct dsl_pool *dp); 75 extern void txg_resume(struct dsl_pool *dp); 76 77 /* 78 * Delay the caller by the specified number of ticks or until 79 * the txg closes (whichever comes first). This is intended 80 * to be used to throttle writers when the system nears its 81 * capacity. 82 */ 83 extern void txg_delay(struct dsl_pool *dp, uint64_t txg, int ticks); 84 85 /* 86 * Wait until the given transaction group has finished syncing. 87 * Try to make this happen as soon as possible (eg. kick off any 88 * necessary syncs immediately). If txg==0, wait for the currently open 89 * txg to finish syncing. 90 */ 91 extern void txg_wait_synced(struct dsl_pool *dp, uint64_t txg); 92 93 /* 94 * Wait until the given transaction group, or one after it, is 95 * the open transaction group. Try to make this happen as soon 96 * as possible (eg. kick off any necessary syncs immediately). 97 * If txg == 0, wait for the next open txg. 98 */ 99 extern void txg_wait_open(struct dsl_pool *dp, uint64_t txg); 100 101 /* 102 * Returns TRUE if we are "backed up" waiting for the syncing 103 * transaction to complete; otherwise returns FALSE. 104 */ 105 extern boolean_t txg_stalled(struct dsl_pool *dp); 106 107 /* returns TRUE if someone is waiting for the next txg to sync */ 108 extern boolean_t txg_sync_waiting(struct dsl_pool *dp); 109 110 /* 111 * Per-txg object lists. 112 */ 113 114 #define TXG_CLEAN(txg) ((txg) - 1) 115 116 extern void txg_list_create(txg_list_t *tl, size_t offset); 117 extern void txg_list_destroy(txg_list_t *tl); 118 extern int txg_list_empty(txg_list_t *tl, uint64_t txg); 119 extern int txg_list_add(txg_list_t *tl, void *p, uint64_t txg); 120 extern void *txg_list_remove(txg_list_t *tl, uint64_t txg); 121 extern void *txg_list_remove_this(txg_list_t *tl, void *p, uint64_t txg); 122 extern int txg_list_member(txg_list_t *tl, void *p, uint64_t txg); 123 extern void *txg_list_head(txg_list_t *tl, uint64_t txg); 124 extern void *txg_list_next(txg_list_t *tl, void *p, uint64_t txg); 125 126 #ifdef __cplusplus 127 } 128 #endif 129 130 #endif /* _SYS_TXG_H */ 131