1 | /* $NetBSD: rf_paritymap.h,v 1.2 2010/03/14 21:11:41 jld Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c) 2009 Jed Davis. |
5 | * All rights reserved. |
6 | * |
7 | * Redistribution and use in source and binary forms, with or without |
8 | * modification, are permitted provided that the following conditions |
9 | * are met: |
10 | * 1. Redistributions of source code must retain the above copyright |
11 | * notice, this list of conditions and the following disclaimer. |
12 | * 2. Redistributions in binary form must reproduce the above copyright |
13 | * notice, this list of conditions and the following disclaimer in the |
14 | * documentation and/or other materials provided with the distribution. |
15 | * |
16 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
17 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
18 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
19 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
20 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
21 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
22 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
23 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
24 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
25 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
26 | * POSSIBILITY OF SUCH DAMAGE. |
27 | */ |
28 | |
29 | #include <sys/mutex.h> |
30 | #include <sys/param.h> |
31 | #include <sys/rwlock.h> |
32 | #include <sys/types.h> |
33 | |
34 | #include <dev/raidframe/raidframevar.h> |
35 | |
36 | /* RF_PARITYMAP_N* in raidframevar.h */ |
37 | |
38 | #define RF_PMLABEL_VALID 1 |
39 | #define RF_PMLABEL_WASUSED 2 |
40 | #define RF_PMLABEL_DISABLE 4 |
41 | |
42 | /* |
43 | * On-disk format: a single bit for each region; if the bit is clear, |
44 | * then the parity is clean. |
45 | */ |
46 | struct rf_paritymap_ondisk |
47 | { |
48 | /* XXX Do these really need to be volatile? */ |
49 | volatile char bits[RF_PARITYMAP_NBYTE]; |
50 | }; |
51 | |
52 | /* In-core per-region state: a byte for each, encoded as follows. */ |
53 | struct rf_paritymap_current |
54 | { |
55 | volatile int8_t state[RF_PARITYMAP_NREG]; |
56 | /* |
57 | * Values: |
58 | * if x == 0, the region may be written out as clean |
59 | * if x > 0, then x outstanding IOs to that region |
60 | * if x < 0, then there was recently IO; periodically increment x |
61 | */ |
62 | }; |
63 | |
64 | /* The entire state. */ |
65 | struct rf_paritymap |
66 | { |
67 | struct rf_paritymap_ondisk *disk_boot, *disk_now; |
68 | struct rf_paritymap_current *current; |
69 | |
70 | /* |
71 | * This lock will be held while component disks' caches are |
72 | * flushed, which could take many milliseconds, so it should |
73 | * not be taken where that kind of delay is unacceptable. |
74 | * Contention on this lock is not, however, expected to be a |
75 | * performance bottleneck. |
76 | */ |
77 | kmutex_t lock; |
78 | /* |
79 | * The flags field, below, has its own lock so that |
80 | * inter-thread communication can occur without taking the |
81 | * overall lock. Ordering is lock -> lk_flags. |
82 | */ |
83 | kmutex_t lk_flags; |
84 | |
85 | RF_Raid_t *raid; |
86 | daddr_t region_size; |
87 | callout_t ticker; |
88 | struct rf_pmparams params; |
89 | volatile int flags; |
90 | struct rf_pmctrs ctrs; |
91 | }; |
92 | |
93 | void rf_paritymap_status(struct rf_paritymap *, struct rf_pmstat *); |
94 | |
95 | int rf_paritymap_test(struct rf_paritymap *, daddr_t); |
96 | void rf_paritymap_begin_region(struct rf_paritymap *, unsigned); |
97 | void rf_paritymap_begin(struct rf_paritymap *, daddr_t, daddr_t); |
98 | void rf_paritymap_end_region(struct rf_paritymap *, unsigned); |
99 | void rf_paritymap_end(struct rf_paritymap *, daddr_t, daddr_t); |
100 | |
101 | void rf_paritymap_checkwork(struct rf_paritymap *); |
102 | void rf_paritymap_invalidate(struct rf_paritymap *); |
103 | void rf_paritymap_forceclean(struct rf_paritymap *); |
104 | void rf_paritymap_write(struct rf_paritymap *); |
105 | |
106 | int rf_paritymap_init(struct rf_paritymap *, RF_Raid_t *, |
107 | const struct rf_pmparams *); |
108 | void rf_paritymap_destroy(struct rf_paritymap *, int); |
109 | |
110 | int rf_paritymap_rewrite(struct rf_paritymap *); |
111 | |
112 | int rf_paritymap_merge(struct rf_paritymap_ondisk *, |
113 | struct rf_paritymap_ondisk *); |
114 | |
115 | int rf_paritymap_ineligible(RF_Raid_t *); |
116 | void rf_paritymap_attach(RF_Raid_t *, int); |
117 | void rf_paritymap_detach(RF_Raid_t *); /* Not while the RAID is live! */ |
118 | |
119 | int rf_paritymap_get_disable(RF_Raid_t *); |
120 | void rf_paritymap_set_disable(RF_Raid_t *, int); |
121 | |
122 | int rf_paritymap_set_params(struct rf_paritymap *, |
123 | const struct rf_pmparams *, int); |
124 | |
125 | void rf_paritymap_init_label(struct rf_paritymap *, |
126 | RF_ComponentLabel_t *); |
127 | |