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 https://opensource.org/licenses/CDDL-1.0.
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 (bounded
45	 * by spa_max_slop), the operation will fail.  Operations which are
46	 * logically creating things should use this (e.g. "zfs create", "zfs
47	 * snapshot").  User writes (via the ZPL / ZVOL) also fail at this
48	 * point.
49	 */
50	ZFS_SPACE_CHECK_NORMAL,
51
52	/*
53	 * Space check allows use of half the slop space.  If there
54	 * is less than 1.6% free space, the operation will fail.  Most
55	 * operations should use this (e.g. "zfs set", "zfs rename"),
56	 * because we want them to succeed even after user writes are failing,
57	 * so that they can be used as part of the space recovery process.
58	 */
59	ZFS_SPACE_CHECK_RESERVED,
60
61	/*
62	 * Space check allows use of three quarters of the slop space.
63	 * If there is less than 0.8% free space, the operation will
64	 * fail.
65	 */
66	ZFS_SPACE_CHECK_EXTRA_RESERVED,
67
68	/*
69	 * In all cases "zfs destroy" is expected to result in an net
70	 * reduction of space, except one. When the pool has a
71	 * checkpoint, space freed by "zfs destroy" will not actually
72	 * free anything internally. Thus, it starts failing after
73	 * three quarters of the slop space is exceeded.
74	 */
75	ZFS_SPACE_CHECK_DESTROY = ZFS_SPACE_CHECK_EXTRA_RESERVED,
76
77	/*
78	 * A channel program can run a "zfs destroy" as part of its
79	 * script and therefore has the same space_check policy when
80	 * being evaluated.
81	 */
82	ZFS_SPACE_CHECK_ZCP_EVAL = ZFS_SPACE_CHECK_DESTROY,
83
84	/*
85	 * No space check is performed. This level of space check should
86	 * be used cautiously as operations that use it can even run when
87	 * 0.8% capacity is left for use. In this scenario, if there is a
88	 * checkpoint, async destroys are suspended and any kind of freeing
89	 * can potentially add space instead of freeing it.
90	 *
91	 * See also the comments above spa_slop_shift.
92	 */
93	ZFS_SPACE_CHECK_NONE,
94
95	ZFS_SPACE_CHECK_DISCARD_CHECKPOINT = ZFS_SPACE_CHECK_NONE,
96
97} zfs_space_check_t;
98
99typedef struct dsl_sync_task {
100	txg_node_t dst_node;
101	struct dsl_pool *dst_pool;
102	uint64_t dst_txg;
103	int dst_space;
104	zfs_space_check_t dst_space_check;
105	dsl_checkfunc_t *dst_checkfunc;
106	dsl_syncfunc_t *dst_syncfunc;
107	void *dst_arg;
108	int dst_error;
109	boolean_t dst_nowaiter;
110} dsl_sync_task_t;
111
112void dsl_sync_task_sync(dsl_sync_task_t *, dmu_tx_t *);
113int dsl_sync_task(const char *, dsl_checkfunc_t *,
114    dsl_syncfunc_t *, void *, int, zfs_space_check_t);
115void dsl_sync_task_nowait(struct dsl_pool *, dsl_syncfunc_t *,
116    void *, dmu_tx_t *);
117int dsl_early_sync_task(const char *, dsl_checkfunc_t *,
118    dsl_syncfunc_t *, void *, int, zfs_space_check_t);
119void dsl_early_sync_task_nowait(struct dsl_pool *, dsl_syncfunc_t *,
120    void *, dmu_tx_t *);
121int dsl_sync_task_sig(const char *, dsl_checkfunc_t *, dsl_syncfunc_t *,
122    dsl_sigfunc_t *, void *, int, zfs_space_check_t);
123
124#ifdef	__cplusplus
125}
126#endif
127
128#endif /* _SYS_DSL_SYNCTASK_H */
129