| 1 | |
| 2 | |
| 3 | * Bad block management
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| 4 | *
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| 5 | * - Heavily based on MD badblocks code from Neil Brown
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| 6 | *
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| 7 | * Copyright (c) 2015, Intel Corporation.
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| 8 |
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| 9 |
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| 10 | #include <linux/badblocks.h>
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| 11 | #include <linux/seqlock.h>
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| 12 | #include <linux/device.h>
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| 13 | #include <linux/kernel.h>
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| 14 | #include <linux/module.h>
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| 15 | #include <linux/stddef.h>
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| 16 | #include <linux/types.h>
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| 17 | #include <linux/slab.h>
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| 18 |
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| 19 | |
| 20 | * The purpose of badblocks set/clear is to manage bad blocks ranges which are
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| 21 | * identified by LBA addresses.
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| 22 | *
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| 23 | * When the caller of badblocks_set() wants to set a range of bad blocks, the
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| 24 | * setting range can be acked or unacked. And the setting range may merge,
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| 25 | * overwrite, skip the overlapped already set range, depends on who they are
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| 26 | * overlapped or adjacent, and the acknowledgment type of the ranges. It can be
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| 27 | * more complicated when the setting range covers multiple already set bad block
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| 28 | * ranges, with restrictions of maximum length of each bad range and the bad
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| 29 | * table space limitation.
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| 30 | *
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| 31 | * It is difficult and unnecessary to take care of all the possible situations,
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| 32 | * for setting a large range of bad blocks, we can handle it by dividing the
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| 33 | * large range into smaller ones when encounter overlap, max range length or
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| 34 | * bad table full conditions. Every time only a smaller piece of the bad range
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| 35 | * is handled with a limited number of conditions how it is interacted with
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| 36 | * possible overlapped or adjacent already set bad block ranges. Then the hard
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| 37 | * complicated problem can be much simpler to handle in proper way.
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| 38 | *
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| 39 | * When setting a range of bad blocks to the bad table, the simplified situations
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| 40 | * to be considered are, (The already set bad blocks ranges are naming with
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| 41 | * prefix E, and the setting bad blocks range is naming with prefix S)
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| 42 | *
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| 43 | * 1) A setting range is not overlapped or adjacent to any other already set bad
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| 44 | * block range.
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| 45 | * +--------+
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| 46 | * | S |
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| 47 | * +--------+
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| 48 | * +-------------+ +-------------+
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| 49 | * | E1 | | E2 |
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| 50 | * +-------------+ +-------------+
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| 51 | * For this situation if the bad blocks table is not full, just allocate a
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| 52 | * free slot from the bad blocks table to mark the setting range S. The
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| 53 | * result is,
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| 54 | * +-------------+ +--------+ +-------------+
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| 55 | * | E1 | | S | | E2 |
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| 56 | * +-------------+ +--------+ +-------------+
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| 57 | * 2) A setting range starts exactly at a start LBA of an already set bad blocks
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| 58 | * range.
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| 59 | * 2.1) The setting range size < already set range size
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| 60 | * +--------+
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| 61 | * | S |
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| 62 | * +--------+
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| 63 | * +-------------+
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| 64 | * | E |
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| 65 | * +-------------+
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| 66 | * 2.1.1) If S and E are both acked or unacked range, the setting range S can
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| 67 | * be merged into existing bad range E. The result is,
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| 68 | * +-------------+
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| 69 | * | S |
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| 70 | * +-------------+
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| 71 | * 2.1.2) If S is unacked setting and E is acked, the setting will be denied, and
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| 72 | * the result is,
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| 73 | * +-------------+
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| 74 | * | E |
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| 75 | * +-------------+
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| 76 | * 2.1.3) If S is acked setting and E is unacked, range S can overwrite on E.
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| 77 | * An extra slot from the bad blocks table will be allocated for S, and head
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| 78 | * of E will move to end of the inserted range S. The result is,
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| 79 | * +--------+----+
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| 80 | * | S | E |
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| 81 | * +--------+----+
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| 82 | * 2.2) The setting range size == already set range size
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| 83 | * 2.2.1) If S and E are both acked or unacked range, the setting range S can
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| 84 | * be merged into existing bad range E. The result is,
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| 85 | * +-------------+
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| 86 | * | S |
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| 87 | * +-------------+
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| 88 | * 2.2.2) If S is unacked setting and E is acked, the setting will be denied, and
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| 89 | * the result is,
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| 90 | * +-------------+
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| 91 | * | E |
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| 92 | * +-------------+
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| 93 | * 2.2.3) If S is acked setting and E is unacked, range S can overwrite all of
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| 94 | bad blocks range E. The result is,
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| 95 | * +-------------+
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| 96 | * | S |
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| 97 | * +-------------+
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| 98 | * 2.3) The setting range size > already set range size
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| 99 | * +-------------------+
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| 100 | * | S |
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| 101 | * +-------------------+
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| 102 | * +-------------+
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| 103 | * | E |
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| 104 | * +-------------+
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| 105 | * For such situation, the setting range S can be treated as two parts, the
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| 106 | * first part (S1) is as same size as the already set range E, the second
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| 107 | * part (S2) is the rest of setting range.
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| 108 | * +-------------+-----+ +-------------+ +-----+
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| 109 | * | S1 | S2 | | S1 | | S2 |
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| 110 | * +-------------+-----+ ===> +-------------+ +-----+
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| 111 | * +-------------+ +-------------+
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| 112 | * | E | | E |
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| 113 | * +-------------+ +-------------+
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| 114 | * Now we only focus on how to handle the setting range S1 and already set
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| 115 | * range E, which are already explained in 2.2), for the rest S2 it will be
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| 116 | * handled later in next loop.
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| 117 | * 3) A setting range starts before the start LBA of an already set bad blocks
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| 118 | * range.
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| 119 | * +-------------+
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| 120 | * | S |
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| 121 | * +-------------+
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| 122 | * +-------------+
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| 123 | * | E |
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| 124 | * +-------------+
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| 125 | * For this situation, the setting range S can be divided into two parts, the
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| 126 | * first (S1) ends at the start LBA of already set range E, the second part
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| 127 | * (S2) starts exactly at a start LBA of the already set range E.
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| 128 | * +----+---------+ +----+ +---------+
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| 129 | * | S1 | S2 | | S1 | | S2 |
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| 130 | * +----+---------+ ===> +----+ +---------+
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| 131 | * +-------------+ +-------------+
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| 132 | * | E | | E |
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| 133 | * +-------------+ +-------------+
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| 134 | * Now only the first part S1 should be handled in this loop, which is in
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| 135 | * similar condition as 1). The rest part S2 has exact same start LBA address
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| 136 | * of the already set range E, they will be handled in next loop in one of
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| 137 | * situations in 2).
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| 138 | * 4) A setting range starts after the start LBA of an already set bad blocks
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| 139 | * range.
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| 140 | * 4.1) If the setting range S exactly matches the tail part of already set bad
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| 141 | * blocks range E, like the following chart shows,
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| 142 | * +---------+
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| 143 | * | S |
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| 144 | * +---------+
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| 145 | * +-------------+
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| 146 | * | E |
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| 147 | * +-------------+
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| 148 | * 4.1.1) If range S and E have same acknowledge value (both acked or unacked),
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| 149 | * they will be merged into one, the result is,
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| 150 | * +-------------+
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| 151 | * | S |
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| 152 | * +-------------+
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| 153 | * 4.1.2) If range E is acked and the setting range S is unacked, the setting
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| 154 | * request of S will be rejected, the result is,
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| 155 | * +-------------+
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| 156 | * | E |
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| 157 | * +-------------+
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| 158 | * 4.1.3) If range E is unacked, and the setting range S is acked, then S may
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| 159 | * overwrite the overlapped range of E, the result is,
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| 160 | * +---+---------+
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| 161 | * | E | S |
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| 162 | * +---+---------+
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| 163 | * 4.2) If the setting range S stays in middle of an already set range E, like
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| 164 | * the following chart shows,
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| 165 | * +----+
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| 166 | * | S |
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| 167 | * +----+
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| 168 | * +--------------+
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| 169 | * | E |
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| 170 | * +--------------+
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| 171 | * 4.2.1) If range S and E have same acknowledge value (both acked or unacked),
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| 172 | * they will be merged into one, the result is,
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| 173 | * +--------------+
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| 174 | * | S |
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| 175 | * +--------------+
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| 176 | * 4.2.2) If range E is acked and the setting range S is unacked, the setting
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| 177 | * request of S will be rejected, the result is also,
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| 178 | * +--------------+
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| 179 | * | E |
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| 180 | * +--------------+
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| 181 | * 4.2.3) If range E is unacked, and the setting range S is acked, then S will
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| 182 | * inserted into middle of E and split previous range E into two parts (E1
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| 183 | * and E2), the result is,
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| 184 | * +----+----+----+
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| 185 | * | E1 | S | E2 |
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| 186 | * +----+----+----+
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| 187 | * 4.3) If the setting bad blocks range S is overlapped with an already set bad
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| 188 | * blocks range E. The range S starts after the start LBA of range E, and
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| 189 | * ends after the end LBA of range E, as the following chart shows,
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| 190 | * +-------------------+
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| 191 | * | S |
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| 192 | * +-------------------+
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| 193 | * +-------------+
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| 194 | * | E |
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| 195 | * +-------------+
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| 196 | * For this situation the range S can be divided into two parts, the first
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| 197 | * part (S1) ends at end range E, and the second part (S2) has rest range of
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| 198 | * origin S.
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| 199 | * +---------+---------+ +---------+ +---------+
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| 200 | * | S1 | S2 | | S1 | | S2 |
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| 201 | * +---------+---------+ ===> +---------+ +---------+
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| 202 | * +-------------+ +-------------+
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| 203 | * | E | | E |
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| 204 | * +-------------+ +-------------+
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| 205 | * Now in this loop the setting range S1 and already set range E can be
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| 206 | * handled as the situations 4.1), the rest range S2 will be handled in next
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| 207 | * loop and ignored in this loop.
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| 208 | * 5) A setting bad blocks range S is adjacent to one or more already set bad
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| 209 | * blocks range(s), and they are all acked or unacked range.
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| 210 | * 5.1) Front merge: If the already set bad blocks range E is before setting
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| 211 | * range S and they are adjacent,
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| 212 | * +------+
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| 213 | * | S |
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| 214 | * +------+
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| 215 | * +-------+
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| 216 | * | E |
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| 217 | * +-------+
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| 218 | * 5.1.1) When total size of range S and E <= BB_MAX_LEN, and their acknowledge
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| 219 | * values are same, the setting range S can front merges into range E. The
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| 220 | * result is,
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| 221 | * +--------------+
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| 222 | * | S |
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| 223 | * +--------------+
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| 224 | * 5.1.2) Otherwise these two ranges cannot merge, just insert the setting
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| 225 | * range S right after already set range E into the bad blocks table. The
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| 226 | * result is,
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| 227 | * +--------+------+
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| 228 | * | E | S |
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| 229 | * +--------+------+
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| 230 | * 6) Special cases which above conditions cannot handle
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| 231 | * 6.1) Multiple already set ranges may merge into less ones in a full bad table
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| 232 | * +-------------------------------------------------------+
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| 233 | * | S |
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| 234 | * +-------------------------------------------------------+
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| 235 | * |<----- BB_MAX_LEN ----->|
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| 236 | * +-----+ +-----+ +-----+
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| 237 | * | E1 | | E2 | | E3 |
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| 238 | * +-----+ +-----+ +-----+
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| 239 | * In the above example, when the bad blocks table is full, inserting the
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| 240 | * first part of setting range S will fail because no more available slot
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| 241 | * can be allocated from bad blocks table. In this situation a proper
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| 242 | * setting method should be go though all the setting bad blocks range and
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| 243 | * look for chance to merge already set ranges into less ones. When there
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| 244 | * is available slot from bad blocks table, re-try again to handle more
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| 245 | * setting bad blocks ranges as many as possible.
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| 246 | * +------------------------+
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| 247 | * | S3 |
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| 248 | * +------------------------+
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| 249 | * |<----- BB_MAX_LEN ----->|
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| 250 | * +-----+-----+-----+---+-----+--+
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| 251 | * | S1 | S2 |
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| 252 | * +-----+-----+-----+---+-----+--+
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| 253 | * The above chart shows although the first part (S3) cannot be inserted due
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| 254 | * to no-space in bad blocks table, but the following E1, E2 and E3 ranges
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| 255 | * can be merged with rest part of S into less range S1 and S2. Now there is
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| 256 | * 1 free slot in bad blocks table.
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| 257 | * +------------------------+-----+-----+-----+---+-----+--+
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| 258 | * | S3 | S1 | S2 |
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| 259 | * +------------------------+-----+-----+-----+---+-----+--+
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| 260 | * Since the bad blocks table is not full anymore, re-try again for the
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| 261 | * origin setting range S. Now the setting range S3 can be inserted into the
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| 262 | * bad blocks table with previous freed slot from multiple ranges merge.
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| 263 | * 6.2) Front merge after overwrite
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| 264 | * In the following example, in bad blocks table, E1 is an acked bad blocks
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| 265 | * range and E2 is an unacked bad blocks range, therefore they are not able
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| 266 | * to merge into a larger range. The setting bad blocks range S is acked,
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| 267 | * therefore part of E2 can be overwritten by S.
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| 268 | * +--------+
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| 269 | * | S | acknowledged
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| 270 | * +--------+ S: 1
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| 271 | * +-------+-------------+ E1: 1
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| 272 | * | E1 | E2 | E2: 0
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| 273 | * +-------+-------------+
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| 274 | * With previous simplified routines, after overwriting part of E2 with S,
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| 275 | * the bad blocks table should be (E3 is remaining part of E2 which is not
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| 276 | * overwritten by S),
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| 277 | * acknowledged
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| 278 | * +-------+--------+----+ S: 1
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| 279 | * | E1 | S | E3 | E1: 1
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| 280 | * +-------+--------+----+ E3: 0
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| 281 | * The above result is correct but not perfect. Range E1 and S in the bad
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| 282 | * blocks table are all acked, merging them into a larger one range may
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| 283 | * occupy less bad blocks table space and make badblocks_check() faster.
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| 284 | * Therefore in such situation, after overwriting range S, the previous range
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| 285 | * E1 should be checked for possible front combination. Then the ideal
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| 286 | * result can be,
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| 287 | * +----------------+----+ acknowledged
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| 288 | * | E1 | E3 | E1: 1
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| 289 | * +----------------+----+ E3: 0
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| 290 | * 6.3) Behind merge: If the already set bad blocks range E is behind the setting
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| 291 | * range S and they are adjacent. Normally we don't need to care about this
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| 292 | * because front merge handles this while going though range S from head to
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| 293 | * tail, except for the tail part of range S. When the setting range S are
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| 294 | * fully handled, all the above simplified routine doesn't check whether the
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| 295 | * tail LBA of range S is adjacent to the next already set range and not
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| 296 | * merge them even it is possible.
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| 297 | * +------+
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| 298 | * | S |
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| 299 | * +------+
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| 300 | * +-------+
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| 301 | * | E |
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| 302 | * +-------+
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| 303 | * For the above special situation, when the setting range S are all handled
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| 304 | * and the loop ends, an extra check is necessary for whether next already
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| 305 | * set range E is right after S and mergeable.
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| 306 | * 6.3.1) When total size of range E and S <= BB_MAX_LEN, and their acknowledge
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| 307 | * values are same, the setting range S can behind merges into range E. The
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| 308 | * result is,
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| 309 | * +--------------+
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| 310 | * | S |
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| 311 | * +--------------+
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| 312 | * 6.3.2) Otherwise these two ranges cannot merge, just insert the setting range
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| 313 | * S in front of the already set range E in the bad blocks table. The result
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| 314 | * is,
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| 315 | * +------+-------+
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| 316 | * | S | E |
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| 317 | * +------+-------+
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| 318 | *
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| 319 | * All the above 5 simplified situations and 3 special cases may cover 99%+ of
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| 320 | * the bad block range setting conditions. Maybe there is some rare corner case
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| 321 | * is not considered and optimized, it won't hurt if badblocks_set() fails due
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| 322 | * to no space, or some ranges are not merged to save bad blocks table space.
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| 323 | *
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| 324 | * Inside badblocks_set() each loop starts by jumping to re_insert label, every
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| 325 | * time for the new loop prev_badblocks() is called to find an already set range
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| 326 | * which starts before or at current setting range. Since the setting bad blocks
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| 327 | * range is handled from head to tail, most of the cases it is unnecessary to do
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| 328 | * the binary search inside prev_badblocks(), it is possible to provide a hint
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| 329 | * to prev_badblocks() for a fast path, then the expensive binary search can be
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| 330 | * avoided. In my test with the hint to prev_badblocks(), except for the first
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| 331 | * loop, all rested calls to prev_badblocks() can go into the fast path and
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| 332 | * return correct bad blocks table index immediately.
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| 333 | *
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| 334 | *
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| 335 | * Clearing a bad blocks range from the bad block table has similar idea as
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| 336 | * setting does, but much more simpler. The only thing needs to be noticed is
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| 337 | * when the clearing range hits middle of a bad block range, the existing bad
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| 338 | * block range will split into two, and one more item should be added into the
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| 339 | * bad block table. The simplified situations to be considered are, (The already
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| 340 | * set bad blocks ranges in bad block table are naming with prefix E, and the
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| 341 | * clearing bad blocks range is naming with prefix C)
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| 342 | *
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| 343 | * 1) A clearing range is not overlapped to any already set ranges in bad block
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| 344 | * table.
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| 345 | * +-----+ | +-----+ | +-----+
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| 346 | * | C | | | C | | | C |
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| 347 | * +-----+ or +-----+ or +-----+
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| 348 | * +---+ | +----+ +----+ | +---+
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| 349 | * | E | | | E1 | | E2 | | | E |
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| 350 | * +---+ | +----+ +----+ | +---+
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| 351 | * For the above situations, no bad block to be cleared and no failure
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| 352 | * happens, simply returns 0.
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| 353 | * 2) The clearing range hits middle of an already setting bad blocks range in
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| 354 | * the bad block table.
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| 355 | * +---+
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| 356 | * | C |
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| 357 | * +---+
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| 358 | * +-----------------+
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| 359 | * | E |
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| 360 | * +-----------------+
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| 361 | * In this situation if the bad block table is not full, the range E will be
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| 362 | * split into two ranges E1 and E2. The result is,
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| 363 | * +------+ +------+
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| 364 | * | E1 | | E2 |
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| 365 | * +------+ +------+
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| 366 | * 3) The clearing range starts exactly at same LBA as an already set bad block range
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| 367 | * from the bad block table.
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| 368 | * 3.1) Partially covered at head part
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| 369 | * +------------+
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| 370 | * | C |
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| 371 | * +------------+
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| 372 | * +-----------------+
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| 373 | * | E |
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| 374 | * +-----------------+
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| 375 | * For this situation, the overlapped already set range will update the
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| 376 | * start LBA to end of C and shrink the range to BB_LEN(E) - BB_LEN(C). No
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| 377 | * item deleted from bad block table. The result is,
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| 378 | * +----+
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| 379 | * | E1 |
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| 380 | * +----+
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| 381 | * 3.2) Exact fully covered
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| 382 | * +-----------------+
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| 383 | * | C |
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| 384 | * +-----------------+
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| 385 | * +-----------------+
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| 386 | * | E |
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| 387 | * +-----------------+
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| 388 | * For this situation the whole bad blocks range E will be cleared and its
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| 389 | * corresponded item is deleted from the bad block table.
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| 390 | * 4) The clearing range exactly ends at same LBA as an already set bad block
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| 391 | * range.
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| 392 | * +-------+
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| 393 | * | C |
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| 394 | * +-------+
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| 395 | * +-----------------+
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| 396 | * | E |
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| 397 | * +-----------------+
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| 398 | * For the above situation, the already set range E is updated to shrink its
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| 399 | * end to the start of C, and reduce its length to BB_LEN(E) - BB_LEN(C).
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| 400 | * The result is,
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| 401 | * +---------+
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| 402 | * | E |
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| 403 | * +---------+
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| 404 | * 5) The clearing range is partially overlapped with an already set bad block
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| 405 | * range from the bad block table.
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| 406 | * 5.1) The already set bad block range is front overlapped with the clearing
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| 407 | * range.
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| 408 | * +----------+
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| 409 | * | C |
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| 410 | * +----------+
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| 411 | * +------------+
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| 412 | * | E |
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| 413 | * +------------+
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| 414 | * For such situation, the clearing range C can be treated as two parts. The
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| 415 | * first part ends at the start LBA of range E, and the second part starts at
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| 416 | * same LBA of range E.
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| 417 | * +----+-----+ +----+ +-----+
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| 418 | * | C1 | C2 | | C1 | | C2 |
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| 419 | * +----+-----+ ===> +----+ +-----+
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| 420 | * +------------+ +------------+
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| 421 | * | E | | E |
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| 422 | * +------------+ +------------+
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| 423 | * Now the first part C1 can be handled as condition 1), and the second part C2 can be
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| 424 | * handled as condition 3.1) in next loop.
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| 425 | * 5.2) The already set bad block range is behind overlaopped with the clearing
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| 426 | * range.
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| 427 | * +----------+
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| 428 | * | C |
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| 429 | * +----------+
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| 430 | * +------------+
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| 431 | * | E |
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| 432 | * +------------+
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| 433 | * For such situation, the clearing range C can be treated as two parts. The
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| 434 | * first part C1 ends at same end LBA of range E, and the second part starts
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| 435 | * at end LBA of range E.
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| 436 | * +----+-----+ +----+ +-----+
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| 437 | * | C1 | C2 | | C1 | | C2 |
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| 438 | * +----+-----+ ===> +----+ +-----+
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| 439 | * +------------+ +------------+
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| 440 | * | E | | E |
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| 441 | * +------------+ +------------+
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| 442 | * Now the first part clearing range C1 can be handled as condition 4), and
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| 443 | * the second part clearing range C2 can be handled as condition 1) in next
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| 444 | * loop.
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| 445 | *
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| 446 | * All bad blocks range clearing can be simplified into the above 5 situations
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| 447 | * by only handling the head part of the clearing range in each run of the
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| 448 | * while-loop. The idea is similar to bad blocks range setting but much
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| 449 | * simpler.
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| 450 |
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| 451 |
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| 452 | |
| 453 | * Find the range starts at-or-before 's' from bad table. The search
|
| 454 | * starts from index 'hint' and stops at index 'hint_end' from the bad
|
| 455 | * table.
|
| 456 |
|
| 457 | static int prev_by_hint(struct badblocks *bb, sector_t s, int hint)
|
| 458 | {
|
| 459 | int hint_end = hint + 2;
|
| 460 | u64 *p = bb->page;
|
| 461 | int ret = -1;
|
| 462 |
|
| 463 | while ((hint < hint_end) && ((hint + 1) <= bb->count) &&
|
| 464 | (BB_OFFSET(p[hint]) <= s)) {
|
| 465 | if ((hint + 1) == bb->count || BB_OFFSET(p[hint + 1]) > s) {
|
| 466 | ret = hint;
|
| 467 | break;
|
| 468 | }
|
| 469 | hint++;
|
| 470 | }
|
| 471 |
|
| 472 | return ret;
|
| 473 | }
|
| 474 |
|
| 475 | |
| 476 | * Find the range starts at-or-before bad->start. If 'hint' is provided
|
| 477 | * (hint >= 0) then search in the bad table from hint firstly. It is
|
| 478 | * very probably the wanted bad range can be found from the hint index,
|
| 479 | * then the unnecessary while-loop iteration can be avoided.
|
| 480 |
|
| 481 | static int prev_badblocks(struct badblocks *bb, struct badblocks_context *bad,
|
| 482 | int hint)
|
| 483 | {
|
| 484 | sector_t s = bad->start;
|
| 485 | int ret = -1;
|
| 486 | int lo, hi;
|
| 487 | u64 *p;
|
| 488 |
|
| 489 | if (!bb->count)
|
| 490 | goto out;
|
| 491 |
|
| 492 | if (hint >= 0) {
|
| 493 | ret = prev_by_hint(bb, s, hint);
|
| 494 | if (ret >= 0)
|
| 495 | goto out;
|
| 496 | }
|
| 497 |
|
| 498 | lo = 0;
|
| 499 | hi = bb->count;
|
| 500 | p = bb->page;
|
| 501 |
|
| 502 |
|
| 503 | if (BB_OFFSET(p[lo]) > s)
|
| 504 | return -1;
|
| 505 | if (BB_OFFSET(p[hi - 1]) <= s)
|
| 506 | return hi - 1;
|
| 507 |
|
| 508 |
|
| 509 | while (hi - lo > 1) {
|
| 510 | int mid = (lo + hi)/2;
|
| 511 | sector_t a = BB_OFFSET(p[mid]);
|
| 512 |
|
| 513 | if (a == s) {
|
| 514 | ret = mid;
|
| 515 | goto out;
|
| 516 | }
|
| 517 |
|
| 518 | if (a < s)
|
| 519 | lo = mid;
|
| 520 | else
|
| 521 | hi = mid;
|
| 522 | }
|
| 523 |
|
| 524 | if (BB_OFFSET(p[lo]) <= s)
|
| 525 | ret = lo;
|
| 526 | out:
|
| 527 | return ret;
|
| 528 | }
|
| 529 |
|
| 530 | |
| 531 | * Return 'true' if the range indicated by 'bad' can be forward
|
| 532 | * merged with the bad range (from the bad table) indexed by 'prev'.
|
| 533 |
|
| 534 | static bool can_merge_front(struct badblocks *bb, int prev,
|
| 535 | struct badblocks_context *bad)
|
| 536 | {
|
| 537 | sector_t s = bad->start;
|
| 538 | u64 *p = bb->page;
|
| 539 |
|
| 540 | if (BB_ACK(p[prev]) == bad->ack &&
|
| 541 | (s < BB_END(p[prev]) ||
|
| 542 | (s == BB_END(p[prev]) && (BB_LEN(p[prev]) < BB_MAX_LEN))))
|
| 543 | return true;
|
| 544 | return false;
|
| 545 | }
|
| 546 |
|
| 547 | |
| 548 | * Do forward merge for range indicated by 'bad' and the bad range
|
| 549 | * (from bad table) indexed by 'prev'. The return value is sectors
|
| 550 | * merged from bad->len.
|
| 551 |
|
| 552 | static int front_merge(struct badblocks *bb, int prev, struct badblocks_context *bad)
|
| 553 | {
|
| 554 | sector_t sectors = bad->len;
|
| 555 | sector_t s = bad->start;
|
| 556 | u64 *p = bb->page;
|
| 557 | int merged = 0;
|
| 558 |
|
| 559 | WARN_ON(s > BB_END(p[prev]));
|
| 560 |
|
| 561 | if (s < BB_END(p[prev])) {
|
| 562 | merged = min_t(sector_t, sectors, BB_END(p[prev]) - s);
|
| 563 | } else {
|
| 564 | merged = min_t(sector_t, sectors, BB_MAX_LEN - BB_LEN(p[prev]));
|
| 565 | if ((prev + 1) < bb->count &&
|
| 566 | merged > (BB_OFFSET(p[prev + 1]) - BB_END(p[prev]))) {
|
| 567 | merged = BB_OFFSET(p[prev + 1]) - BB_END(p[prev]);
|
| 568 | }
|
| 569 |
|
| 570 | p[prev] = BB_MAKE(BB_OFFSET(p[prev]),
|
| 571 | BB_LEN(p[prev]) + merged, bad->ack);
|
| 572 | }
|
| 573 |
|
| 574 | return merged;
|
| 575 | }
|
| 576 |
|
| 577 | |
| 578 | * 'Combine' is a special case which can_merge_front() is not able to
|
| 579 | * handle: If a bad range (indexed by 'prev' from bad table) exactly
|
| 580 | * starts as bad->start, and the bad range ahead of 'prev' (indexed by
|
| 581 | * 'prev - 1' from bad table) exactly ends at where 'prev' starts, and
|
| 582 | * the sum of their lengths does not exceed BB_MAX_LEN limitation, then
|
| 583 | * these two bad range (from bad table) can be combined.
|
| 584 | *
|
| 585 | * Return 'true' if bad ranges indexed by 'prev' and 'prev - 1' from bad
|
| 586 | * table can be combined.
|
| 587 |
|
| 588 | static bool can_combine_front(struct badblocks *bb, int prev,
|
| 589 | struct badblocks_context *bad)
|
| 590 | {
|
| 591 | u64 *p = bb->page;
|
| 592 |
|
| 593 | if ((prev > 0) &&
|
| 594 | (BB_OFFSET(p[prev]) == bad->start) &&
|
| 595 | (BB_END(p[prev - 1]) == BB_OFFSET(p[prev])) &&
|
| 596 | (BB_LEN(p[prev - 1]) + BB_LEN(p[prev]) <= BB_MAX_LEN) &&
|
| 597 | (BB_ACK(p[prev - 1]) == BB_ACK(p[prev])))
|
| 598 | return true;
|
| 599 | return false;
|
| 600 | }
|
| 601 |
|
| 602 | |
| 603 | * Combine the bad ranges indexed by 'prev' and 'prev - 1' (from bad
|
| 604 | * table) into one larger bad range, and the new range is indexed by
|
| 605 | * 'prev - 1'.
|
| 606 | * The caller of front_combine() will decrease bb->count, therefore
|
| 607 | * it is unnecessary to clear p[perv] after front merge.
|
| 608 |
|
| 609 | static void front_combine(struct badblocks *bb, int prev)
|
| 610 | {
|
| 611 | u64 *p = bb->page;
|
| 612 |
|
| 613 | p[prev - 1] = BB_MAKE(BB_OFFSET(p[prev - 1]),
|
| 614 | BB_LEN(p[prev - 1]) + BB_LEN(p[prev]),
|
| 615 | BB_ACK(p[prev]));
|
| 616 | if ((prev + 1) < bb->count)
|
| 617 | memmove(p + prev, p + prev + 1, (bb->count - prev - 1) * 8);
|
| 618 | }
|
| 619 |
|
| 620 | |
| 621 | * Return 'true' if the range indicated by 'bad' is exactly forward
|
| 622 | * overlapped with the bad range (from bad table) indexed by 'front'.
|
| 623 | * Exactly forward overlap means the bad range (from bad table) indexed
|
| 624 | * by 'prev' does not cover the whole range indicated by 'bad'.
|
| 625 |
|
| 626 | static bool overlap_front(struct badblocks *bb, int front,
|
| 627 | struct badblocks_context *bad)
|
| 628 | {
|
| 629 | u64 *p = bb->page;
|
| 630 |
|
| 631 | if (bad->start >= BB_OFFSET(p[front]) &&
|
| 632 | bad->start < BB_END(p[front]))
|
| 633 | return true;
|
| 634 | return false;
|
| 635 | }
|
| 636 |
|
| 637 | |
| 638 | * Return 'true' if the range indicated by 'bad' is exactly backward
|
| 639 | * overlapped with the bad range (from bad table) indexed by 'behind'.
|
| 640 |
|
| 641 | static bool overlap_behind(struct badblocks *bb, struct badblocks_context *bad,
|
| 642 | int behind)
|
| 643 | {
|
| 644 | u64 *p = bb->page;
|
| 645 |
|
| 646 | if (bad->start < BB_OFFSET(p[behind]) &&
|
| 647 | (bad->start + bad->len) > BB_OFFSET(p[behind]))
|
| 648 | return true;
|
| 649 | return false;
|
| 650 | }
|
| 651 |
|
| 652 | |
| 653 | * Return 'true' if the range indicated by 'bad' can overwrite the bad
|
| 654 | * range (from bad table) indexed by 'prev'.
|
| 655 | *
|
| 656 | * The range indicated by 'bad' can overwrite the bad range indexed by
|
| 657 | * 'prev' when,
|
| 658 | * 1) The whole range indicated by 'bad' can cover partial or whole bad
|
| 659 | * range (from bad table) indexed by 'prev'.
|
| 660 | * 2) The ack value of 'bad' is larger or equal to the ack value of bad
|
| 661 | * range 'prev'.
|
| 662 | *
|
| 663 | * If the overwriting doesn't cover the whole bad range (from bad table)
|
| 664 | * indexed by 'prev', new range might be split from existing bad range,
|
| 665 | * 1) The overwrite covers head or tail part of existing bad range, 1
|
| 666 | * extra bad range will be split and added into the bad table.
|
| 667 | * 2) The overwrite covers middle of existing bad range, 2 extra bad
|
| 668 | * ranges will be split (ahead and after the overwritten range) and
|
| 669 | * added into the bad table.
|
| 670 | * The number of extra split ranges of the overwriting is stored in
|
| 671 | * 'extra' and returned for the caller.
|
| 672 |
|
| 673 | static bool can_front_overwrite(struct badblocks *bb, int prev,
|
| 674 | struct badblocks_context *bad, int *extra)
|
| 675 | {
|
| 676 | u64 *p = bb->page;
|
| 677 | int len;
|
| 678 |
|
| 679 | WARN_ON(!overlap_front(bb, prev, bad));
|
| 680 |
|
| 681 | if (BB_ACK(p[prev]) >= bad->ack)
|
| 682 | return false;
|
| 683 |
|
| 684 | if (BB_END(p[prev]) <= (bad->start + bad->len)) {
|
| 685 | len = BB_END(p[prev]) - bad->start;
|
| 686 | if (BB_OFFSET(p[prev]) == bad->start)
|
| 687 | *extra = 0;
|
| 688 | else
|
| 689 | *extra = 1;
|
| 690 |
|
| 691 | bad->len = len;
|
| 692 | } else {
|
| 693 | if (BB_OFFSET(p[prev]) == bad->start)
|
| 694 | *extra = 1;
|
| 695 | else
|
| 696 | |
| 697 | * prev range will be split into two, beside the overwritten
|
| 698 | * one, an extra slot needed from bad table.
|
| 699 |
|
| 700 | *extra = 2;
|
| 701 | }
|
| 702 |
|
| 703 | if ((bb->count + (*extra)) > MAX_BADBLOCKS)
|
| 704 | return false;
|
| 705 |
|
| 706 | return true;
|
| 707 | }
|
| 708 |
|
| 709 | |
| 710 | * Do the overwrite from the range indicated by 'bad' to the bad range
|
| 711 | * (from bad table) indexed by 'prev'.
|
| 712 | * The previously called can_front_overwrite() will provide how many
|
| 713 | * extra bad range(s) might be split and added into the bad table. All
|
| 714 | * the splitting cases in the bad table will be handled here.
|
| 715 |
|
| 716 | static int front_overwrite(struct badblocks *bb, int prev,
|
| 717 | struct badblocks_context *bad, int extra)
|
| 718 | {
|
| 719 | u64 *p = bb->page;
|
| 720 | sector_t orig_end = BB_END(p[prev]);
|
| 721 | int orig_ack = BB_ACK(p[prev]);
|
| 722 |
|
| 723 | switch (extra) {
|
| 724 | case 0:
|
| 725 | p[prev] = BB_MAKE(BB_OFFSET(p[prev]), BB_LEN(p[prev]),
|
| 726 | bad->ack);
|
| 727 | break;
|
| 728 | case 1:
|
| 729 | if (BB_OFFSET(p[prev]) == bad->start) {
|
| 730 | p[prev] = BB_MAKE(BB_OFFSET(p[prev]),
|
| 731 | bad->len, bad->ack);
|
| 732 | memmove(p + prev + 2, p + prev + 1,
|
| 733 | (bb->count - prev - 1) * 8);
|
| 734 | p[prev + 1] = BB_MAKE(bad->start + bad->len,
|
| 735 | orig_end - BB_END(p[prev]),
|
| 736 | orig_ack);
|
| 737 | } else {
|
| 738 | p[prev] = BB_MAKE(BB_OFFSET(p[prev]),
|
| 739 | bad->start - BB_OFFSET(p[prev]),
|
| 740 | orig_ack);
|
| 741 | |
| 742 | * prev +2 -> prev + 1 + 1, which is for,
|
| 743 | * 1) prev + 1: the slot index of the previous one
|
| 744 | * 2) + 1: one more slot for extra being 1.
|
| 745 |
|
| 746 | memmove(p + prev + 2, p + prev + 1,
|
| 747 | (bb->count - prev - 1) * 8);
|
| 748 | p[prev + 1] = BB_MAKE(bad->start, bad->len, bad->ack);
|
| 749 | }
|
| 750 | break;
|
| 751 | case 2:
|
| 752 | p[prev] = BB_MAKE(BB_OFFSET(p[prev]),
|
| 753 | bad->start - BB_OFFSET(p[prev]),
|
| 754 | orig_ack);
|
| 755 | |
| 756 | * prev + 3 -> prev + 1 + 2, which is for,
|
| 757 | * 1) prev + 1: the slot index of the previous one
|
| 758 | * 2) + 2: two more slots for extra being 2.
|
| 759 |
|
| 760 | memmove(p + prev + 3, p + prev + 1,
|
| 761 | (bb->count - prev - 1) * 8);
|
| 762 | p[prev + 1] = BB_MAKE(bad->start, bad->len, bad->ack);
|
| 763 | p[prev + 2] = BB_MAKE(BB_END(p[prev + 1]),
|
| 764 | orig_end - BB_END(p[prev + 1]),
|
| 765 | orig_ack);
|
| 766 | break;
|
| 767 | default:
|
| 768 | break;
|
| 769 | }
|
| 770 |
|
| 771 | return bad->len;
|
| 772 | }
|
| 773 |
|
| 774 | |
| 775 | * Explicitly insert a range indicated by 'bad' to the bad table, where
|
| 776 | * the location is indexed by 'at'.
|
| 777 |
|
| 778 | static int insert_at(struct badblocks *bb, int at, struct badblocks_context *bad)
|
| 779 | {
|
| 780 | u64 *p = bb->page;
|
| 781 | int len;
|
| 782 |
|
| 783 | WARN_ON(badblocks_full(bb));
|
| 784 |
|
| 785 | len = min_t(sector_t, bad->len, BB_MAX_LEN);
|
| 786 | if (at < bb->count)
|
| 787 | memmove(p + at + 1, p + at, (bb->count - at) * 8);
|
| 788 | p[at] = BB_MAKE(bad->start, len, bad->ack);
|
| 789 |
|
| 790 | return len;
|
| 791 | }
|
| 792 |
|
| 793 | static void badblocks_update_acked(struct badblocks *bb)
|
| 794 | {
|
| 795 | bool unacked = false;
|
| 796 | u64 *p = bb->page;
|
| 797 | int i;
|
| 798 |
|
| 799 | if (!bb->unacked_exist)
|
| 800 | return;
|
| 801 |
|
| 802 | for (i = 0; i < bb->count ; i++) {
|
| 803 | if (!BB_ACK(p[i])) {
|
| 804 | unacked = true;
|
| 805 | break;
|
| 806 | }
|
| 807 | }
|
| 808 |
|
| 809 | if (!unacked)
|
| 810 | bb->unacked_exist = 0;
|
| 811 | }
|
| 812 |
|
| 813 | |
| 814 | * Return 'true' if the range indicated by 'bad' is exactly backward
|
| 815 | * overlapped with the bad range (from bad table) indexed by 'behind'.
|
| 816 |
|
| 817 | static bool try_adjacent_combine(struct badblocks *bb, int prev)
|
| 818 | {
|
| 819 | u64 *p = bb->page;
|
| 820 |
|
| 821 | if (prev >= 0 && (prev + 1) < bb->count &&
|
| 822 | BB_END(p[prev]) == BB_OFFSET(p[prev + 1]) &&
|
| 823 | (BB_LEN(p[prev]) + BB_LEN(p[prev + 1])) <= BB_MAX_LEN &&
|
| 824 | BB_ACK(p[prev]) == BB_ACK(p[prev + 1])) {
|
| 825 | p[prev] = BB_MAKE(BB_OFFSET(p[prev]),
|
| 826 | BB_LEN(p[prev]) + BB_LEN(p[prev + 1]),
|
| 827 | BB_ACK(p[prev]));
|
| 828 |
|
| 829 | if ((prev + 2) < bb->count)
|
| 830 | memmove(p + prev + 1, p + prev + 2,
|
| 831 | (bb->count - (prev + 2)) * 8);
|
| 832 | bb->count--;
|
| 833 | return true;
|
| 834 | }
|
| 835 | return false;
|
| 836 | }
|
| 837 |
|
| 838 |
|
| 839 | static bool _badblocks_set(struct badblocks *bb, sector_t s, sector_t sectors,
|
| 840 | int acknowledged)
|
| 841 | {
|
| 842 | int len = 0, added = 0;
|
| 843 | struct badblocks_context bad;
|
| 844 | int prev = -1, hint = -1;
|
| 845 | unsigned long flags;
|
| 846 | u64 *p;
|
| 847 |
|
| 848 | if (bb->shift < 0)
|
| 849 |
|
| 850 | return false;
|
| 851 |
|
| 852 | if (sectors == 0)
|
| 853 |
|
| 854 | return false;
|
| 855 |
|
| 856 | if (bb->shift) {
|
| 857 |
|
| 858 | sector_t next = s + sectors;
|
| 859 |
|
| 860 | rounddown(s, 1 << bb->shift);
|
| 861 | roundup(next, 1 << bb->shift);
|
| 862 | sectors = next - s;
|
| 863 | }
|
| 864 |
|
| 865 | write_seqlock_irqsave(&bb->lock, flags);
|
| 866 |
|
| 867 | bad.ack = acknowledged;
|
| 868 | p = bb->page;
|
| 869 |
|
| 870 | re_insert:
|
| 871 | bad.start = s;
|
| 872 | bad.len = sectors;
|
| 873 | len = 0;
|
| 874 |
|
| 875 | if (badblocks_full(bb))
|
| 876 | goto out;
|
| 877 |
|
| 878 | if (badblocks_empty(bb)) {
|
| 879 | len = insert_at(bb, 0, &bad);
|
| 880 | bb->count++;
|
| 881 | added++;
|
| 882 | goto update_sectors;
|
| 883 | }
|
| 884 |
|
| 885 | prev = prev_badblocks(bb, &bad, hint);
|
| 886 |
|
| 887 |
|
| 888 | if (prev < 0) {
|
| 889 |
|
| 890 | if (bad.len > (BB_OFFSET(p[0]) - bad.start))
|
| 891 | bad.len = BB_OFFSET(p[0]) - bad.start;
|
| 892 | len = insert_at(bb, 0, &bad);
|
| 893 | bb->count++;
|
| 894 | added++;
|
| 895 | hint = ++prev;
|
| 896 | goto update_sectors;
|
| 897 | }
|
| 898 |
|
| 899 |
|
| 900 | if (can_combine_front(bb, prev, &bad)) {
|
| 901 | front_combine(bb, prev);
|
| 902 | bb->count--;
|
| 903 | added++;
|
| 904 | hint = prev;
|
| 905 | goto update_sectors;
|
| 906 | }
|
| 907 |
|
| 908 | if (can_merge_front(bb, prev, &bad)) {
|
| 909 | len = front_merge(bb, prev, &bad);
|
| 910 | added++;
|
| 911 | hint = prev;
|
| 912 | goto update_sectors;
|
| 913 | }
|
| 914 |
|
| 915 | if (overlap_front(bb, prev, &bad)) {
|
| 916 | int extra = 0;
|
| 917 |
|
| 918 | if (!can_front_overwrite(bb, prev, &bad, &extra)) {
|
| 919 | if (extra > 0)
|
| 920 | goto out;
|
| 921 |
|
| 922 | len = min_t(sector_t,
|
| 923 | BB_END(p[prev]) - s, sectors);
|
| 924 | hint = prev;
|
| 925 | goto update_sectors;
|
| 926 | }
|
| 927 |
|
| 928 | len = front_overwrite(bb, prev, &bad, extra);
|
| 929 | added++;
|
| 930 | bb->count += extra;
|
| 931 |
|
| 932 | if (can_combine_front(bb, prev, &bad)) {
|
| 933 | front_combine(bb, prev);
|
| 934 | bb->count--;
|
| 935 | }
|
| 936 |
|
| 937 | hint = prev;
|
| 938 | goto update_sectors;
|
| 939 | }
|
| 940 |
|
| 941 |
|
| 942 | if ((prev + 1) < bb->count &&
|
| 943 | overlap_behind(bb, &bad, prev + 1))
|
| 944 | bad.len = min_t(sector_t,
|
| 945 | bad.len, BB_OFFSET(p[prev + 1]) - bad.start);
|
| 946 |
|
| 947 | len = insert_at(bb, prev + 1, &bad);
|
| 948 | bb->count++;
|
| 949 | added++;
|
| 950 | hint = ++prev;
|
| 951 |
|
| 952 | update_sectors:
|
| 953 | s += len;
|
| 954 | sectors -= len;
|
| 955 |
|
| 956 | if (sectors > 0)
|
| 957 | goto re_insert;
|
| 958 |
|
| 959 | |
| 960 | * Check whether the following already set range can be
|
| 961 | * merged. (prev < 0) condition is not handled here,
|
| 962 | * because it's already complicated enough.
|
| 963 |
|
| 964 | try_adjacent_combine(bb, prev);
|
| 965 |
|
| 966 | out:
|
| 967 | if (added) {
|
| 968 | set_changed(bb);
|
| 969 |
|
| 970 | if (!acknowledged)
|
| 971 | bb->unacked_exist = 1;
|
| 972 | else
|
| 973 | badblocks_update_acked(bb);
|
| 974 | }
|
| 975 |
|
| 976 | write_sequnlock_irqrestore(&bb->lock, flags);
|
| 977 |
|
| 978 | return sectors == 0;
|
| 979 | }
|
| 980 |
|
| 981 | |
| 982 | * Clear the bad block range from bad block table which is front overlapped
|
| 983 | * with the clearing range. The return value is how many sectors from an
|
| 984 | * already set bad block range are cleared. If the whole bad block range is
|
| 985 | * covered by the clearing range and fully cleared, 'delete' is set as 1 for
|
| 986 | * the caller to reduce bb->count.
|
| 987 |
|
| 988 | static int front_clear(struct badblocks *bb, int prev,
|
| 989 | struct badblocks_context *bad, int *deleted)
|
| 990 | {
|
| 991 | sector_t sectors = bad->len;
|
| 992 | sector_t s = bad->start;
|
| 993 | u64 *p = bb->page;
|
| 994 | int cleared = 0;
|
| 995 |
|
| 996 | *deleted = 0;
|
| 997 | if (s == BB_OFFSET(p[prev])) {
|
| 998 | if (BB_LEN(p[prev]) > sectors) {
|
| 999 | p[prev] = BB_MAKE(BB_OFFSET(p[prev]) + sectors,
|
| 1000 | BB_LEN(p[prev]) - sectors,
|
| 1001 | BB_ACK(p[prev]));
|
| 1002 | cleared = sectors;
|
| 1003 | } else {
|
| 1004 |
|
| 1005 | cleared = BB_LEN(p[prev]);
|
| 1006 | if ((prev + 1) < bb->count)
|
| 1007 | memmove(p + prev, p + prev + 1,
|
| 1008 | (bb->count - prev - 1) * 8);
|
| 1009 | *deleted = 1;
|
| 1010 | }
|
| 1011 | } else if (s > BB_OFFSET(p[prev])) {
|
| 1012 | if (BB_END(p[prev]) <= (s + sectors)) {
|
| 1013 | cleared = BB_END(p[prev]) - s;
|
| 1014 | p[prev] = BB_MAKE(BB_OFFSET(p[prev]),
|
| 1015 | s - BB_OFFSET(p[prev]),
|
| 1016 | BB_ACK(p[prev]));
|
| 1017 | } else {
|
| 1018 |
|
| 1019 | BUG();
|
| 1020 | }
|
| 1021 | }
|
| 1022 |
|
| 1023 | return cleared;
|
| 1024 | }
|
| 1025 |
|
| 1026 | |
| 1027 | * Handle the condition that the clearing range hits middle of an already set
|
| 1028 | * bad block range from bad block table. In this condition the existing bad
|
| 1029 | * block range is split into two after the middle part is cleared.
|
| 1030 |
|
| 1031 | static int front_splitting_clear(struct badblocks *bb, int prev,
|
| 1032 | struct badblocks_context *bad)
|
| 1033 | {
|
| 1034 | u64 *p = bb->page;
|
| 1035 | u64 end = BB_END(p[prev]);
|
| 1036 | int ack = BB_ACK(p[prev]);
|
| 1037 | sector_t sectors = bad->len;
|
| 1038 | sector_t s = bad->start;
|
| 1039 |
|
| 1040 | p[prev] = BB_MAKE(BB_OFFSET(p[prev]),
|
| 1041 | s - BB_OFFSET(p[prev]),
|
| 1042 | ack);
|
| 1043 | memmove(p + prev + 2, p + prev + 1, (bb->count - prev - 1) * 8);
|
| 1044 | p[prev + 1] = BB_MAKE(s + sectors, end - s - sectors, ack);
|
| 1045 | return sectors;
|
| 1046 | }
|
| 1047 |
|
| 1048 |
|
| 1049 | static bool _badblocks_clear(struct badblocks *bb, sector_t s, sector_t sectors)
|
| 1050 | {
|
| 1051 | struct badblocks_context bad;
|
| 1052 | int prev = -1, hint = -1;
|
| 1053 | int len = 0, cleared = 0;
|
| 1054 | u64 *p;
|
| 1055 |
|
| 1056 | if (bb->shift < 0)
|
| 1057 |
|
| 1058 | return false;
|
| 1059 |
|
| 1060 | if (sectors == 0)
|
| 1061 |
|
| 1062 | return false;
|
| 1063 |
|
| 1064 | if (bb->shift) {
|
| 1065 | sector_t target;
|
| 1066 |
|
| 1067 | |
| 1068 | * This should not matter as the shift should align with
|
| 1069 | * the block size and no rounding should ever be needed.
|
| 1070 | * However it is better the think a block is bad when it
|
| 1071 | * isn't than to think a block is not bad when it is.
|
| 1072 |
|
| 1073 | target = s + sectors;
|
| 1074 | roundup(s, 1 << bb->shift);
|
| 1075 | rounddown(target, 1 << bb->shift);
|
| 1076 | sectors = target - s;
|
| 1077 | }
|
| 1078 |
|
| 1079 | write_seqlock_irq(&bb->lock);
|
| 1080 |
|
| 1081 | bad.ack = true;
|
| 1082 | p = bb->page;
|
| 1083 |
|
| 1084 | re_clear:
|
| 1085 | bad.start = s;
|
| 1086 | bad.len = sectors;
|
| 1087 |
|
| 1088 | if (badblocks_empty(bb)) {
|
| 1089 | len = sectors;
|
| 1090 | cleared++;
|
| 1091 | goto update_sectors;
|
| 1092 | }
|
| 1093 |
|
| 1094 |
|
| 1095 | prev = prev_badblocks(bb, &bad, hint);
|
| 1096 |
|
| 1097 |
|
| 1098 | if (prev < 0) {
|
| 1099 | if (overlap_behind(bb, &bad, 0)) {
|
| 1100 | len = BB_OFFSET(p[0]) - s;
|
| 1101 | hint = 0;
|
| 1102 | } else {
|
| 1103 | len = sectors;
|
| 1104 | }
|
| 1105 | |
| 1106 | * Both situations are to clear non-bad range,
|
| 1107 | * should be treated as successful
|
| 1108 |
|
| 1109 | cleared++;
|
| 1110 | goto update_sectors;
|
| 1111 | }
|
| 1112 |
|
| 1113 |
|
| 1114 | if ((prev + 1) >= bb->count && !overlap_front(bb, prev, &bad)) {
|
| 1115 | len = sectors;
|
| 1116 | cleared++;
|
| 1117 | goto update_sectors;
|
| 1118 | }
|
| 1119 |
|
| 1120 |
|
| 1121 | if (badblocks_full(bb) && (BB_OFFSET(p[prev]) < bad.start) &&
|
| 1122 | (BB_END(p[prev]) > (bad.start + sectors))) {
|
| 1123 | len = sectors;
|
| 1124 | goto update_sectors;
|
| 1125 | }
|
| 1126 |
|
| 1127 | if (overlap_front(bb, prev, &bad)) {
|
| 1128 | if ((BB_OFFSET(p[prev]) < bad.start) &&
|
| 1129 | (BB_END(p[prev]) > (bad.start + bad.len))) {
|
| 1130 |
|
| 1131 | if ((bb->count + 1) <= MAX_BADBLOCKS) {
|
| 1132 | len = front_splitting_clear(bb, prev, &bad);
|
| 1133 | bb->count += 1;
|
| 1134 | cleared++;
|
| 1135 | } else {
|
| 1136 |
|
| 1137 | len = sectors;
|
| 1138 | }
|
| 1139 | } else {
|
| 1140 | int deleted = 0;
|
| 1141 |
|
| 1142 | len = front_clear(bb, prev, &bad, &deleted);
|
| 1143 | bb->count -= deleted;
|
| 1144 | cleared++;
|
| 1145 | hint = prev;
|
| 1146 | }
|
| 1147 |
|
| 1148 | goto update_sectors;
|
| 1149 | }
|
| 1150 |
|
| 1151 |
|
| 1152 | if ((prev + 1) < bb->count && overlap_behind(bb, &bad, prev + 1)) {
|
| 1153 | len = BB_OFFSET(p[prev + 1]) - bad.start;
|
| 1154 | hint = prev + 1;
|
| 1155 |
|
| 1156 | cleared++;
|
| 1157 | goto update_sectors;
|
| 1158 | }
|
| 1159 |
|
| 1160 |
|
| 1161 | len = sectors;
|
| 1162 |
|
| 1163 | cleared++;
|
| 1164 |
|
| 1165 | update_sectors:
|
| 1166 | s += len;
|
| 1167 | sectors -= len;
|
| 1168 |
|
| 1169 | if (sectors > 0)
|
| 1170 | goto re_clear;
|
| 1171 |
|
| 1172 | if (cleared) {
|
| 1173 | badblocks_update_acked(bb);
|
| 1174 | set_changed(bb);
|
| 1175 | }
|
| 1176 |
|
| 1177 | write_sequnlock_irq(&bb->lock);
|
| 1178 |
|
| 1179 | if (!cleared)
|
| 1180 | return false;
|
| 1181 |
|
| 1182 | return true;
|
| 1183 | }
|
| 1184 |
|
| 1185 |
|
| 1186 | static int _badblocks_check(struct badblocks *bb, sector_t s, sector_t sectors,
|
| 1187 | sector_t *first_bad, sector_t *bad_sectors)
|
| 1188 | {
|
| 1189 | int prev = -1, hint = -1, set = 0;
|
| 1190 | struct badblocks_context bad;
|
| 1191 | int unacked_badblocks = 0;
|
| 1192 | int acked_badblocks = 0;
|
| 1193 | u64 *p = bb->page;
|
| 1194 | int len, rv;
|
| 1195 |
|
| 1196 | re_check:
|
| 1197 | bad.start = s;
|
| 1198 | bad.len = sectors;
|
| 1199 |
|
| 1200 | if (badblocks_empty(bb)) {
|
| 1201 | len = sectors;
|
| 1202 | goto update_sectors;
|
| 1203 | }
|
| 1204 |
|
| 1205 | prev = prev_badblocks(bb, &bad, hint);
|
| 1206 |
|
| 1207 |
|
| 1208 | if ((prev >= 0) &&
|
| 1209 | ((prev + 1) >= bb->count) && !overlap_front(bb, prev, &bad)) {
|
| 1210 | len = sectors;
|
| 1211 | goto update_sectors;
|
| 1212 | }
|
| 1213 |
|
| 1214 |
|
| 1215 | if ((prev >= 0) && overlap_front(bb, prev, &bad)) {
|
| 1216 | if (BB_ACK(p[prev]))
|
| 1217 | acked_badblocks++;
|
| 1218 | else
|
| 1219 | unacked_badblocks++;
|
| 1220 |
|
| 1221 | if (BB_END(p[prev]) >= (s + sectors))
|
| 1222 | len = sectors;
|
| 1223 | else
|
| 1224 | len = BB_END(p[prev]) - s;
|
| 1225 |
|
| 1226 | if (set == 0) {
|
| 1227 | *first_bad = BB_OFFSET(p[prev]);
|
| 1228 | *bad_sectors = BB_LEN(p[prev]);
|
| 1229 | set = 1;
|
| 1230 | }
|
| 1231 | goto update_sectors;
|
| 1232 | }
|
| 1233 |
|
| 1234 |
|
| 1235 | if ((prev + 1) < bb->count && overlap_behind(bb, &bad, prev + 1)) {
|
| 1236 | len = BB_OFFSET(p[prev + 1]) - bad.start;
|
| 1237 | hint = prev + 1;
|
| 1238 | goto update_sectors;
|
| 1239 | }
|
| 1240 |
|
| 1241 |
|
| 1242 | len = sectors;
|
| 1243 |
|
| 1244 | update_sectors:
|
| 1245 |
|
| 1246 | WARN_ON(sectors < len);
|
| 1247 |
|
| 1248 | s += len;
|
| 1249 | sectors -= len;
|
| 1250 |
|
| 1251 | if (sectors > 0)
|
| 1252 | goto re_check;
|
| 1253 |
|
| 1254 | if (unacked_badblocks > 0)
|
| 1255 | rv = -1;
|
| 1256 | else if (acked_badblocks > 0)
|
| 1257 | rv = 1;
|
| 1258 | else
|
| 1259 | rv = 0;
|
| 1260 |
|
| 1261 | return rv;
|
| 1262 | }
|
| 1263 |
|
| 1264 | |
| 1265 | * badblocks_check() - check a given range for bad sectors
|
| 1266 | * @bb: the badblocks structure that holds all badblock information
|
| 1267 | * @s: sector (start) at which to check for badblocks
|
| 1268 | * @sectors: number of sectors to check for badblocks
|
| 1269 | * @first_bad: pointer to store location of the first badblock
|
| 1270 | * @bad_sectors: pointer to store number of badblocks after @first_bad
|
| 1271 | *
|
| 1272 | * We can record which blocks on each device are 'bad' and so just
|
| 1273 | * fail those blocks, or that stripe, rather than the whole device.
|
| 1274 | * Entries in the bad-block table are 64bits wide. This comprises:
|
| 1275 | * Length of bad-range, in sectors: 0-511 for lengths 1-512
|
| 1276 | * Start of bad-range, sector offset, 54 bits (allows 8 exbibytes)
|
| 1277 | * A 'shift' can be set so that larger blocks are tracked and
|
| 1278 | * consequently larger devices can be covered.
|
| 1279 | * 'Acknowledged' flag - 1 bit. - the most significant bit.
|
| 1280 | *
|
| 1281 | * Locking of the bad-block table uses a seqlock so badblocks_check
|
| 1282 | * might need to retry if it is very unlucky.
|
| 1283 | * We will sometimes want to check for bad blocks in a bi_end_io function,
|
| 1284 | * so we use the write_seqlock_irq variant.
|
| 1285 | *
|
| 1286 | * When looking for a bad block we specify a range and want to
|
| 1287 | * know if any block in the range is bad. So we binary-search
|
| 1288 | * to the last range that starts at-or-before the given endpoint,
|
| 1289 | * (or "before the sector after the target range")
|
| 1290 | * then see if it ends after the given start.
|
| 1291 | *
|
| 1292 | * Return:
|
| 1293 | * 0: there are no known bad blocks in the range
|
| 1294 | * 1: there are known bad block which are all acknowledged
|
| 1295 | * -1: there are bad blocks which have not yet been acknowledged in metadata.
|
| 1296 | * plus the start/length of the first bad section we overlap.
|
| 1297 |
|
| 1298 | int badblocks_check(struct badblocks *bb, sector_t s, sector_t sectors,
|
| 1299 | sector_t *first_bad, sector_t *bad_sectors)
|
| 1300 | {
|
| 1301 | unsigned int seq;
|
| 1302 | int rv;
|
| 1303 |
|
| 1304 | WARN_ON(bb->shift < 0 || sectors == 0);
|
| 1305 |
|
| 1306 | if (bb->shift > 0) {
|
| 1307 |
|
| 1308 | sector_t target = s + sectors;
|
| 1309 |
|
| 1310 | rounddown(s, 1 << bb->shift);
|
| 1311 | roundup(target, 1 << bb->shift);
|
| 1312 | sectors = target - s;
|
| 1313 | }
|
| 1314 |
|
| 1315 | retry:
|
| 1316 | seq = read_seqbegin(&bb->lock);
|
| 1317 | rv = _badblocks_check(bb, s, sectors, first_bad, bad_sectors);
|
| 1318 | if (read_seqretry(&bb->lock, seq))
|
| 1319 | goto retry;
|
| 1320 |
|
| 1321 | return rv;
|
| 1322 | }
|
| 1323 | EXPORT_SYMBOL_GPL(badblocks_check);
|
| 1324 |
|
| 1325 | |
| 1326 | * badblocks_set() - Add a range of bad blocks to the table.
|
| 1327 | * @bb: the badblocks structure that holds all badblock information
|
| 1328 | * @s: first sector to mark as bad
|
| 1329 | * @sectors: number of sectors to mark as bad
|
| 1330 | * @acknowledged: weather to mark the bad sectors as acknowledged
|
| 1331 | *
|
| 1332 | * This might extend the table, or might contract it if two adjacent ranges
|
| 1333 | * can be merged. We binary-search to find the 'insertion' point, then
|
| 1334 | * decide how best to handle it.
|
| 1335 | *
|
| 1336 | * Return:
|
| 1337 | * true: success
|
| 1338 | * false: failed to set badblocks (out of space). Parital setting will be
|
| 1339 | * treated as failure.
|
| 1340 |
|
| 1341 | bool badblocks_set(struct badblocks *bb, sector_t s, sector_t sectors,
|
| 1342 | int acknowledged)
|
| 1343 | {
|
| 1344 | return _badblocks_set(bb, s, sectors, acknowledged);
|
| 1345 | }
|
| 1346 | EXPORT_SYMBOL_GPL(badblocks_set);
|
| 1347 |
|
| 1348 | |
| 1349 | * badblocks_clear() - Remove a range of bad blocks to the table.
|
| 1350 | * @bb: the badblocks structure that holds all badblock information
|
| 1351 | * @s: first sector to mark as bad
|
| 1352 | * @sectors: number of sectors to mark as bad
|
| 1353 | *
|
| 1354 | * This may involve extending the table if we spilt a region,
|
| 1355 | * but it must not fail. So if the table becomes full, we just
|
| 1356 | * drop the remove request.
|
| 1357 | *
|
| 1358 | * Return:
|
| 1359 | * true: success
|
| 1360 | * false: failed to clear badblocks
|
| 1361 |
|
| 1362 | bool badblocks_clear(struct badblocks *bb, sector_t s, sector_t sectors)
|
| 1363 | {
|
| 1364 | return _badblocks_clear(bb, s, sectors);
|
| 1365 | }
|
| 1366 | EXPORT_SYMBOL_GPL(badblocks_clear);
|
| 1367 |
|
| 1368 | |
| 1369 | * ack_all_badblocks() - Acknowledge all bad blocks in a list.
|
| 1370 | * @bb: the badblocks structure that holds all badblock information
|
| 1371 | *
|
| 1372 | * This only succeeds if ->changed is clear. It is used by
|
| 1373 | * in-kernel metadata updates
|
| 1374 |
|
| 1375 | void ack_all_badblocks(struct badblocks *bb)
|
| 1376 | {
|
| 1377 | if (bb->page == NULL || bb->changed)
|
| 1378 |
|
| 1379 | return;
|
| 1380 | write_seqlock_irq(&bb->lock);
|
| 1381 |
|
| 1382 | if (bb->changed == 0 && bb->unacked_exist) {
|
| 1383 | u64 *p = bb->page;
|
| 1384 | int i;
|
| 1385 |
|
| 1386 | for (i = 0; i < bb->count ; i++) {
|
| 1387 | if (!BB_ACK(p[i])) {
|
| 1388 | sector_t start = BB_OFFSET(p[i]);
|
| 1389 | int len = BB_LEN(p[i]);
|
| 1390 |
|
| 1391 | p[i] = BB_MAKE(start, len, 1);
|
| 1392 | }
|
| 1393 | }
|
| 1394 |
|
| 1395 | for (i = 0; i < bb->count ; i++)
|
| 1396 | while (try_adjacent_combine(bb, i))
|
| 1397 | ;
|
| 1398 |
|
| 1399 | bb->unacked_exist = 0;
|
| 1400 | }
|
| 1401 | write_sequnlock_irq(&bb->lock);
|
| 1402 | }
|
| 1403 | EXPORT_SYMBOL_GPL(ack_all_badblocks);
|
| 1404 |
|
| 1405 | |
| 1406 | * badblocks_show() - sysfs access to bad-blocks list
|
| 1407 | * @bb: the badblocks structure that holds all badblock information
|
| 1408 | * @page: buffer received from sysfs
|
| 1409 | * @unack: weather to show unacknowledged badblocks
|
| 1410 | *
|
| 1411 | * Return:
|
| 1412 | * Length of returned data
|
| 1413 |
|
| 1414 | ssize_t badblocks_show(struct badblocks *bb, char *page, int unack)
|
| 1415 | {
|
| 1416 | size_t len;
|
| 1417 | int i;
|
| 1418 | u64 *p = bb->page;
|
| 1419 | unsigned seq;
|
| 1420 |
|
| 1421 | if (bb->shift < 0)
|
| 1422 | return 0;
|
| 1423 |
|
| 1424 | retry:
|
| 1425 | seq = read_seqbegin(&bb->lock);
|
| 1426 |
|
| 1427 | len = 0;
|
| 1428 | i = 0;
|
| 1429 |
|
| 1430 | while (len < PAGE_SIZE && i < bb->count) {
|
| 1431 | sector_t s = BB_OFFSET(p[i]);
|
| 1432 | unsigned int length = BB_LEN(p[i]);
|
| 1433 | int ack = BB_ACK(p[i]);
|
| 1434 |
|
| 1435 | i++;
|
| 1436 |
|
| 1437 | if (unack && ack)
|
| 1438 | continue;
|
| 1439 |
|
| 1440 | len += snprintf(page+len, PAGE_SIZE-len, "%llu %u\n",
|
| 1441 | (unsigned long long)s << bb->shift,
|
| 1442 | length << bb->shift);
|
| 1443 | }
|
| 1444 | if (unack && len == 0)
|
| 1445 | bb->unacked_exist = 0;
|
| 1446 |
|
| 1447 | if (read_seqretry(&bb->lock, seq))
|
| 1448 | goto retry;
|
| 1449 |
|
| 1450 | return len;
|
| 1451 | }
|
| 1452 | EXPORT_SYMBOL_GPL(badblocks_show);
|
| 1453 |
|
| 1454 | |
| 1455 | * badblocks_store() - sysfs access to bad-blocks list
|
| 1456 | * @bb: the badblocks structure that holds all badblock information
|
| 1457 | * @page: buffer received from sysfs
|
| 1458 | * @len: length of data received from sysfs
|
| 1459 | * @unack: weather to show unacknowledged badblocks
|
| 1460 | *
|
| 1461 | * Return:
|
| 1462 | * Length of the buffer processed or -ve error.
|
| 1463 |
|
| 1464 | ssize_t badblocks_store(struct badblocks *bb, const char *page, size_t len,
|
| 1465 | int unack)
|
| 1466 | {
|
| 1467 | unsigned long long sector;
|
| 1468 | int length;
|
| 1469 | char newline;
|
| 1470 |
|
| 1471 | switch (sscanf(page, "%llu %d%c", §or, &length, &newline)) {
|
| 1472 | case 3:
|
| 1473 | if (newline != '\n')
|
| 1474 | return -EINVAL;
|
| 1475 | fallthrough;
|
| 1476 | case 2:
|
| 1477 | if (length <= 0)
|
| 1478 | return -EINVAL;
|
| 1479 | break;
|
| 1480 | default:
|
| 1481 | return -EINVAL;
|
| 1482 | }
|
| 1483 |
|
| 1484 | if (!badblocks_set(bb, sector, length, !unack))
|
| 1485 | return -ENOSPC;
|
| 1486 |
|
| 1487 | return len;
|
| 1488 | }
|
| 1489 | EXPORT_SYMBOL_GPL(badblocks_store);
|
| 1490 |
|
| 1491 | static int __badblocks_init(struct device *dev, struct badblocks *bb,
|
| 1492 | int enable)
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| 1493 | {
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| 1494 | bb->dev = dev;
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| 1495 | bb->count = 0;
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| 1496 | if (enable)
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| 1497 | bb->shift = 0;
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| 1498 | else
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| 1499 | bb->shift = -1;
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| 1500 | if (dev)
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| 1501 | bb->page = devm_kzalloc(dev, PAGE_SIZE, GFP_KERNEL);
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| 1502 | else
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| 1503 | bb->page = kzalloc(PAGE_SIZE, GFP_KERNEL);
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| 1504 | if (!bb->page) {
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| 1505 | bb->shift = -1;
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| 1506 | return -ENOMEM;
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| 1507 | }
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| 1508 | seqlock_init(&bb->lock);
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| 1509 |
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| 1510 | return 0;
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| 1511 | }
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| 1512 |
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| 1513 | |
| 1514 | * badblocks_init() - initialize the badblocks structure
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| 1515 | * @bb: the badblocks structure that holds all badblock information
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| 1516 | * @enable: weather to enable badblocks accounting
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| 1517 | *
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| 1518 | * Return:
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| 1519 | * 0: success
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| 1520 | * -ve errno: on error
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| 1521 |
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| 1522 | int badblocks_init(struct badblocks *bb, int enable)
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| 1523 | {
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| 1524 | return __badblocks_init(NULL, bb, enable);
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| 1525 | }
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| 1526 | EXPORT_SYMBOL_GPL(badblocks_init);
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| 1527 |
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| 1528 | int devm_init_badblocks(struct device *dev, struct badblocks *bb)
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| 1529 | {
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| 1530 | if (!bb)
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| 1531 | return -EINVAL;
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| 1532 | return __badblocks_init(dev, bb, 1);
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| 1533 | }
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| 1534 | EXPORT_SYMBOL_GPL(devm_init_badblocks);
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| 1535 |
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| 1536 | |
| 1537 | * badblocks_exit() - free the badblocks structure
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| 1538 | * @bb: the badblocks structure that holds all badblock information
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| 1539 |
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| 1540 | void badblocks_exit(struct badblocks *bb)
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| 1541 | {
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| 1542 | if (!bb)
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| 1543 | return;
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| 1544 | if (bb->dev)
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| 1545 | devm_kfree(bb->dev, bb->page);
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| 1546 | else
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| 1547 | kfree(bb->page);
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| 1548 | bb->page = NULL;
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| 1549 | }
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| 1550 | EXPORT_SYMBOL_GPL(badblocks_exit);
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