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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
24 */
25
26#ifndef	_SYS_DSL_SYNCTASK_H
27#define	_SYS_DSL_SYNCTASK_H
28
29#include <sys/txg.h>
30#include <sys/zfs_context.h>
31
32#ifdef	__cplusplus
33extern "C" {
34#endif
35
36struct dsl_pool;
37
38typedef int (dsl_checkfunc_t)(void *, dmu_tx_t *);
39typedef void (dsl_syncfunc_t)(void *, dmu_tx_t *);
40typedef void (dsl_sigfunc_t)(void *, dmu_tx_t *);
41
42typedef enum zfs_space_check {
43	/*
44	 * Normal space check: if there is less than 3.2% free space,
45	 * the operation will fail.  Operations which are logically
46	 * creating things should use this (e.g. "zfs create", "zfs snapshot").
47	 * User writes (via the ZPL / ZVOL) also fail at this point.
48	 */
49	ZFS_SPACE_CHECK_NORMAL,
50
51	/*
52	 * Space check allows use of half the slop space.  If there
53	 * is less than 1.6% free space, the operation will fail.  Most
54	 * operations should use this (e.g. "zfs set", "zfs rename"),
55	 * because we want them to succeed even after user writes are failing,
56	 * so that they can be used as part of the space recovery process.
57	 */
58	ZFS_SPACE_CHECK_RESERVED,
59
60	/*
61	 * Space check allows use of three quarters of the slop space.
62	 * If there is less than 0.8% free space, the operation will
63	 * fail.
64	 */
65	ZFS_SPACE_CHECK_EXTRA_RESERVED,
66
67	/*
68	 * In all cases "zfs destroy" is expected to result in an net
69	 * reduction of space, except one. When the pool has a
70	 * checkpoint, space freed by "zfs destroy" will not actually
71	 * free anything internally. Thus, it starts failing after
72	 * three quarters of the slop space is exceeded.
73	 */
74	ZFS_SPACE_CHECK_DESTROY = ZFS_SPACE_CHECK_EXTRA_RESERVED,
75
76	/*
77	 * A channel program can run a "zfs destroy" as part of its
78	 * script and therefore has the same space_check policy when
79	 * being evaluated.
80	 */
81	ZFS_SPACE_CHECK_ZCP_EVAL = ZFS_SPACE_CHECK_DESTROY,
82
83	/*
84	 * No space check is performed. This level of space check should
85	 * be used cautiously as operations that use it can even run when
86	 * 0.8% capacity is left for use. In this scenario, if there is a
87	 * checkpoint, async destroys are suspended and any kind of freeing
88	 * can potentially add space instead of freeing it.
89	 *
90	 * See also the comments above spa_slop_shift.
91	 */
92	ZFS_SPACE_CHECK_NONE,
93
94	ZFS_SPACE_CHECK_DISCARD_CHECKPOINT = ZFS_SPACE_CHECK_NONE,
95
96} zfs_space_check_t;
97
98typedef struct dsl_sync_task {
99	txg_node_t dst_node;
100	struct dsl_pool *dst_pool;
101	uint64_t dst_txg;
102	int dst_space;
103	zfs_space_check_t dst_space_check;
104	dsl_checkfunc_t *dst_checkfunc;
105	dsl_syncfunc_t *dst_syncfunc;
106	void *dst_arg;
107	int dst_error;
108	boolean_t dst_nowaiter;
109} dsl_sync_task_t;
110
111void dsl_sync_task_sync(dsl_sync_task_t *, dmu_tx_t *);
112int dsl_sync_task(const char *, dsl_checkfunc_t *,
113    dsl_syncfunc_t *, void *, int, zfs_space_check_t);
114void dsl_sync_task_nowait(struct dsl_pool *, dsl_syncfunc_t *,
115    void *, int, zfs_space_check_t, dmu_tx_t *);
116int dsl_early_sync_task(const char *, dsl_checkfunc_t *,
117    dsl_syncfunc_t *, void *, int, zfs_space_check_t);
118void dsl_early_sync_task_nowait(struct dsl_pool *, dsl_syncfunc_t *,
119    void *, int, zfs_space_check_t, dmu_tx_t *);
120int dsl_sync_task_sig(const char *, dsl_checkfunc_t *, dsl_syncfunc_t *,
121    dsl_sigfunc_t *, void *, int, zfs_space_check_t);
122
123#ifdef	__cplusplus
124}
125#endif
126
127#endif /* _SYS_DSL_SYNCTASK_H */
128