xref: /freebsd-head/sys/contrib/openzfs/include/sys/txg.h (revision 071ab5a1f3cbfd29c8fbec27f7e619418adaf074)
1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3  * CDDL HEADER START
4  *
5  * The contents of this file are subject to the terms of the
6  * Common Development and Distribution License (the "License").
7  * You may not use this file except in compliance with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or https://opensource.org/licenses/CDDL-1.0.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 /*
27  * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
28  */
29 
30 #ifndef _SYS_TXG_H
31 #define	_SYS_TXG_H
32 
33 #include <sys/spa.h>
34 #include <sys/zfs_context.h>
35 
36 #ifdef	__cplusplus
37 extern "C" {
38 #endif
39 
40 #define	TXG_CONCURRENT_STATES	3	/* open, quiescing, syncing	*/
41 #define	TXG_SIZE		4		/* next power of 2	*/
42 #define	TXG_MASK		(TXG_SIZE - 1)	/* mask for size	*/
43 #define	TXG_INITIAL		TXG_SIZE	/* initial txg 		*/
44 #define	TXG_IDX			(txg & TXG_MASK)
45 #define	TXG_UNKNOWN		0
46 
47 /* Number of txgs worth of frees we defer adding to in-core spacemaps */
48 #define	TXG_DEFER_SIZE		2
49 
50 typedef struct tx_cpu tx_cpu_t;
51 
52 typedef struct txg_handle {
53 	tx_cpu_t	*th_cpu;
54 	uint64_t	th_txg;
55 } txg_handle_t;
56 
57 typedef struct txg_node {
58 	struct txg_node	*tn_next[TXG_SIZE];
59 	uint8_t		tn_member[TXG_SIZE];
60 } txg_node_t;
61 
62 typedef struct txg_list {
63 	kmutex_t	tl_lock;
64 	size_t		tl_offset;
65 	spa_t		*tl_spa;
66 	txg_node_t	*tl_head[TXG_SIZE];
67 } txg_list_t;
68 
69 /*
70  * Wait flags for txg_wait_synced_flags(). By default (TXG_WAIT_NONE), it will
71  * wait until the wanted txg is reached, or block forever. Additional flags
72  * indicate other conditions that the caller is interested in, that will cause
73  * the wait to break and return an error code describing the condition.
74  */
75 typedef enum {
76 	/* No special flags. Guaranteed to block forever or return 0 */
77 	TXG_WAIT_NONE   = 0,
78 
79 	/* If a signal arrives while waiting, abort and return EINTR */
80 	TXG_WAIT_SIGNAL = (1 << 0),
81 } txg_wait_flag_t;
82 
83 struct dsl_pool;
84 
85 extern void txg_init(struct dsl_pool *dp, uint64_t txg);
86 extern void txg_fini(struct dsl_pool *dp);
87 extern void txg_sync_start(struct dsl_pool *dp);
88 extern void txg_sync_stop(struct dsl_pool *dp);
89 extern uint64_t txg_hold_open(struct dsl_pool *dp, txg_handle_t *txghp);
90 extern void txg_rele_to_quiesce(txg_handle_t *txghp);
91 extern void txg_rele_to_sync(txg_handle_t *txghp);
92 extern void txg_register_callbacks(txg_handle_t *txghp, list_t *tx_callbacks);
93 
94 extern void txg_delay(struct dsl_pool *dp, uint64_t txg, hrtime_t delta,
95     hrtime_t resolution);
96 extern void txg_kick(struct dsl_pool *dp, uint64_t txg);
97 
98 /*
99  * Wait until the given transaction group has finished syncing.
100  * Try to make this happen as soon as possible (eg. kick off any
101  * necessary syncs immediately).  If txg==0, wait for the currently open
102  * txg to finish syncing.
103  * See txg_wait_flag_t above for a description of how the flags affect the wait.
104  */
105 extern int txg_wait_synced_flags(struct dsl_pool *dp, uint64_t txg,
106     txg_wait_flag_t flags);
107 
108 /*
109  * Traditional form of txg_wait_synced_flags, waits forever.
110  * Shorthand for VERIFY0(txg_wait_synced_flags(dp, TXG_WAIT_NONE))
111  */
112 extern void txg_wait_synced(struct dsl_pool *dp, uint64_t txg);
113 
114 /*
115  * Wait until the given transaction group, or one after it, is
116  * the open transaction group.  Try to make this happen as soon
117  * as possible (eg. kick off any necessary syncs immediately) when
118  * should_quiesce is set.  If txg == 0, wait for the next open txg.
119  */
120 extern void txg_wait_open(struct dsl_pool *dp, uint64_t txg,
121     boolean_t should_quiesce);
122 
123 /*
124  * Returns TRUE if we are "backed up" waiting for the syncing
125  * transaction to complete; otherwise returns FALSE.
126  */
127 extern boolean_t txg_stalled(struct dsl_pool *dp);
128 
129 /* returns TRUE if someone is waiting for the next txg to sync */
130 extern boolean_t txg_sync_waiting(struct dsl_pool *dp);
131 
132 extern void txg_verify(spa_t *spa, uint64_t txg);
133 
134 /*
135  * Wait for pending commit callbacks of already-synced transactions to finish
136  * processing.
137  */
138 extern void txg_wait_callbacks(struct dsl_pool *dp);
139 
140 /*
141  * Per-txg object lists.
142  */
143 
144 #define	TXG_CLEAN(txg)	((txg) - 1)
145 
146 extern void txg_list_create(txg_list_t *tl, spa_t *spa, size_t offset);
147 extern void txg_list_destroy(txg_list_t *tl);
148 extern boolean_t txg_list_empty(txg_list_t *tl, uint64_t txg);
149 extern boolean_t txg_all_lists_empty(txg_list_t *tl);
150 extern boolean_t txg_list_add(txg_list_t *tl, void *p, uint64_t txg);
151 extern boolean_t txg_list_add_tail(txg_list_t *tl, void *p, uint64_t txg);
152 extern void *txg_list_remove(txg_list_t *tl, uint64_t txg);
153 extern void *txg_list_remove_this(txg_list_t *tl, void *p, uint64_t txg);
154 extern boolean_t txg_list_member(txg_list_t *tl, void *p, uint64_t txg);
155 extern void *txg_list_head(txg_list_t *tl, uint64_t txg);
156 extern void *txg_list_next(txg_list_t *tl, void *p, uint64_t txg);
157 
158 /* Global tuning */
159 extern uint_t zfs_txg_timeout;
160 
161 
162 #ifdef ZFS_DEBUG
163 #define	TXG_VERIFY(spa, txg)		txg_verify(spa, txg)
164 #else
165 #define	TXG_VERIFY(spa, txg)
166 #endif
167 
168 #ifdef	__cplusplus
169 }
170 #endif
171 
172 #endif	/* _SYS_TXG_H */
173