| 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 | |