xref: /titanic_50/usr/src/uts/common/fs/zfs/sys/dsl_scan.h (revision 7802d7bf98dec568dadf72286893b1fe5abd8602)
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) 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
24  */
25 
26 #ifndef	_SYS_DSL_SCAN_H
27 #define	_SYS_DSL_SCAN_H
28 
29 #include <sys/zfs_context.h>
30 #include <sys/zio.h>
31 #include <sys/ddt.h>
32 #include <sys/bplist.h>
33 
34 #ifdef	__cplusplus
35 extern "C" {
36 #endif
37 
38 struct objset;
39 struct dsl_dir;
40 struct dsl_dataset;
41 struct dsl_pool;
42 struct dmu_tx;
43 
44 /*
45  * All members of this structure must be uint64_t, for byteswap
46  * purposes.
47  */
48 typedef struct dsl_scan_phys {
49 	uint64_t scn_func; /* pool_scan_func_t */
50 	uint64_t scn_state; /* dsl_scan_state_t */
51 	uint64_t scn_queue_obj;
52 	uint64_t scn_min_txg;
53 	uint64_t scn_max_txg;
54 	uint64_t scn_cur_min_txg;
55 	uint64_t scn_cur_max_txg;
56 	uint64_t scn_start_time;
57 	uint64_t scn_end_time;
58 	uint64_t scn_to_examine; /* total bytes to be scanned */
59 	uint64_t scn_examined; /* bytes scanned so far */
60 	uint64_t scn_to_process;
61 	uint64_t scn_processed;
62 	uint64_t scn_errors;	/* scan I/O error count */
63 	uint64_t scn_ddt_class_max;
64 	ddt_bookmark_t scn_ddt_bookmark;
65 	zbookmark_phys_t scn_bookmark;
66 	uint64_t scn_flags; /* dsl_scan_flags_t */
67 } dsl_scan_phys_t;
68 
69 #define	SCAN_PHYS_NUMINTS (sizeof (dsl_scan_phys_t) / sizeof (uint64_t))
70 
71 typedef enum dsl_scan_flags {
72 	DSF_VISIT_DS_AGAIN = 1<<0,
73 } dsl_scan_flags_t;
74 
75 /*
76  * Every pool will have one dsl_scan_t and this structure will contain
77  * in-memory information about the scan and a pointer to the on-disk
78  * representation (i.e. dsl_scan_phys_t). Most of the state of the scan
79  * is contained on-disk to allow the scan to resume in the event of a reboot
80  * or panic. This structure maintains information about the behavior of a
81  * running scan, some caching information, and how it should traverse the pool.
82  *
83  * The following members of this structure direct the behavior of the scan:
84  *
85  * scn_pausing -	a scan that cannot be completed in a single txg or
86  *			has exceeded its allotted time will need to pause.
87  *			When this flag is set the scanner will stop traversing
88  *			the pool and write out the current state to disk.
89  *
90  * scn_restart_txg -	directs the scanner to either restart or start a
91  *			a scan at the specified txg value.
92  *
93  * scn_done_txg -	when a scan completes its traversal it will set
94  *			the completion txg to the next txg. This is necessary
95  *			to ensure that any blocks that were freed during
96  *			the scan but have not yet been processed (i.e deferred
97  *			frees) are accounted for.
98  *
99  * This structure also maintains information about deferred frees which are
100  * a special kind of traversal. Deferred free can exist in either a bptree or
101  * a bpobj structure. The scn_is_bptree flag will indicate the type of
102  * deferred free that is in progress. If the deferred free is part of an
103  * asynchronous destroy then the scn_async_destroying flag will be set.
104  */
105 typedef struct dsl_scan {
106 	struct dsl_pool *scn_dp;
107 
108 	boolean_t scn_pausing;
109 	uint64_t scn_restart_txg;
110 	uint64_t scn_done_txg;
111 	uint64_t scn_sync_start_time;
112 	zio_t *scn_zio_root;
113 
114 	/* for freeing blocks */
115 	boolean_t scn_is_bptree;
116 	boolean_t scn_async_destroying;
117 	boolean_t scn_async_stalled;
118 
119 	/* for debugging / information */
120 	uint64_t scn_visited_this_txg;
121 
122 	dsl_scan_phys_t scn_phys;
123 } dsl_scan_t;
124 
125 int dsl_scan_init(struct dsl_pool *dp, uint64_t txg);
126 void dsl_scan_fini(struct dsl_pool *dp);
127 void dsl_scan_sync(struct dsl_pool *, dmu_tx_t *);
128 int dsl_scan_cancel(struct dsl_pool *);
129 int dsl_scan(struct dsl_pool *, pool_scan_func_t);
130 void dsl_resilver_restart(struct dsl_pool *, uint64_t txg);
131 boolean_t dsl_scan_resilvering(struct dsl_pool *dp);
132 boolean_t dsl_dataset_unstable(struct dsl_dataset *ds);
133 void dsl_scan_ddt_entry(dsl_scan_t *scn, enum zio_checksum checksum,
134     ddt_entry_t *dde, dmu_tx_t *tx);
135 void dsl_scan_ds_destroyed(struct dsl_dataset *ds, struct dmu_tx *tx);
136 void dsl_scan_ds_snapshotted(struct dsl_dataset *ds, struct dmu_tx *tx);
137 void dsl_scan_ds_clone_swapped(struct dsl_dataset *ds1, struct dsl_dataset *ds2,
138     struct dmu_tx *tx);
139 boolean_t dsl_scan_active(dsl_scan_t *scn);
140 
141 #ifdef	__cplusplus
142 }
143 #endif
144 
145 #endif /* _SYS_DSL_SCAN_H */
146