Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2001-2003 Sistina Software (UK) Limited. |
| 3 | * |
| 4 | * This file is released under the GPL. |
| 5 | */ |
| 6 | |
Mikulas Patocka | 586e80e | 2008-10-21 17:44:59 +0100 | [diff] [blame] | 7 | #include <linux/device-mapper.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | |
| 9 | #include <linux/module.h> |
| 10 | #include <linux/init.h> |
| 11 | #include <linux/blkdev.h> |
| 12 | #include <linux/bio.h> |
| 13 | #include <linux/slab.h> |
vignesh babu | 6f3c3f0 | 2007-10-19 22:38:44 +0100 | [diff] [blame] | 14 | #include <linux/log2.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 16 | #define DM_MSG_PREFIX "striped" |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 17 | #define DM_IO_ERROR_THRESHOLD 15 |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 18 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | struct stripe { |
| 20 | struct dm_dev *dev; |
| 21 | sector_t physical_start; |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 22 | |
| 23 | atomic_t error_count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | }; |
| 25 | |
| 26 | struct stripe_c { |
| 27 | uint32_t stripes; |
Mikulas Patocka | c96053b | 2010-08-12 04:14:21 +0100 | [diff] [blame] | 28 | int stripes_shift; |
| 29 | sector_t stripes_mask; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | |
| 31 | /* The size of this target / num. stripes */ |
| 32 | sector_t stripe_width; |
| 33 | |
| 34 | /* stripe chunk size */ |
| 35 | uint32_t chunk_shift; |
| 36 | sector_t chunk_mask; |
| 37 | |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 38 | /* Needed for handling events */ |
| 39 | struct dm_target *ti; |
| 40 | |
| 41 | /* Work struct used for triggering events*/ |
Tejun Heo | f521f07 | 2011-01-13 19:59:57 +0000 | [diff] [blame] | 42 | struct work_struct trigger_event; |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 43 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | struct stripe stripe[0]; |
| 45 | }; |
| 46 | |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 47 | /* |
| 48 | * An event is triggered whenever a drive |
| 49 | * drops out of a stripe volume. |
| 50 | */ |
| 51 | static void trigger_event(struct work_struct *work) |
| 52 | { |
Tejun Heo | f521f07 | 2011-01-13 19:59:57 +0000 | [diff] [blame] | 53 | struct stripe_c *sc = container_of(work, struct stripe_c, |
| 54 | trigger_event); |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 55 | dm_table_event(sc->ti->table); |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 56 | } |
| 57 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | static inline struct stripe_c *alloc_context(unsigned int stripes) |
| 59 | { |
| 60 | size_t len; |
| 61 | |
Mikulas Patocka | d63a5ce | 2008-10-21 17:44:57 +0100 | [diff] [blame] | 62 | if (dm_array_too_big(sizeof(struct stripe_c), sizeof(struct stripe), |
| 63 | stripes)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | return NULL; |
| 65 | |
| 66 | len = sizeof(struct stripe_c) + (sizeof(struct stripe) * stripes); |
| 67 | |
| 68 | return kmalloc(len, GFP_KERNEL); |
| 69 | } |
| 70 | |
| 71 | /* |
| 72 | * Parse a single <dev> <sector> pair |
| 73 | */ |
| 74 | static int get_stripe(struct dm_target *ti, struct stripe_c *sc, |
| 75 | unsigned int stripe, char **argv) |
| 76 | { |
Andrew Morton | 4ee218c | 2006-03-27 01:17:48 -0800 | [diff] [blame] | 77 | unsigned long long start; |
Mikulas Patocka | 31998ef | 2012-03-28 18:41:26 +0100 | [diff] [blame] | 78 | char dummy; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | |
Mikulas Patocka | 31998ef | 2012-03-28 18:41:26 +0100 | [diff] [blame] | 80 | if (sscanf(argv[1], "%llu%c", &start, &dummy) != 1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | return -EINVAL; |
| 82 | |
Nikanth Karthikesan | 8215d6e | 2010-03-06 02:32:27 +0000 | [diff] [blame] | 83 | if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | &sc->stripe[stripe].dev)) |
| 85 | return -ENXIO; |
| 86 | |
| 87 | sc->stripe[stripe].physical_start = start; |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 88 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | return 0; |
| 90 | } |
| 91 | |
| 92 | /* |
| 93 | * Construct a striped mapping. |
| 94 | * <number of stripes> <chunk size (2^^n)> [<dev_path> <offset>]+ |
| 95 | */ |
| 96 | static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv) |
| 97 | { |
| 98 | struct stripe_c *sc; |
| 99 | sector_t width; |
| 100 | uint32_t stripes; |
| 101 | uint32_t chunk_size; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | int r; |
| 103 | unsigned int i; |
| 104 | |
| 105 | if (argc < 2) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 106 | ti->error = "Not enough arguments"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | return -EINVAL; |
| 108 | } |
| 109 | |
majianpeng | 1a66a08 | 2012-07-27 15:07:59 +0100 | [diff] [blame^] | 110 | if (kstrtouint(argv[0], 10, &stripes) || !stripes) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 111 | ti->error = "Invalid stripe count"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | return -EINVAL; |
| 113 | } |
| 114 | |
majianpeng | 1a66a08 | 2012-07-27 15:07:59 +0100 | [diff] [blame^] | 115 | if (kstrtouint(argv[1], 10, &chunk_size)) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 116 | ti->error = "Invalid chunk_size"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | return -EINVAL; |
| 118 | } |
| 119 | |
| 120 | /* |
| 121 | * chunk_size is a power of two |
| 122 | */ |
vignesh babu | 6f3c3f0 | 2007-10-19 22:38:44 +0100 | [diff] [blame] | 123 | if (!is_power_of_2(chunk_size) || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | (chunk_size < (PAGE_SIZE >> SECTOR_SHIFT))) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 125 | ti->error = "Invalid chunk size"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | return -EINVAL; |
| 127 | } |
| 128 | |
Kevin Corry | a22c96c | 2006-03-27 01:18:01 -0800 | [diff] [blame] | 129 | if (ti->len & (chunk_size - 1)) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 130 | ti->error = "Target length not divisible by " |
Kevin Corry | 8ba32fd | 2006-03-16 23:04:03 -0800 | [diff] [blame] | 131 | "chunk size"; |
| 132 | return -EINVAL; |
| 133 | } |
| 134 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | width = ti->len; |
| 136 | if (sector_div(width, stripes)) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 137 | ti->error = "Target length not divisible by " |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | "number of stripes"; |
| 139 | return -EINVAL; |
| 140 | } |
| 141 | |
| 142 | /* |
| 143 | * Do we have enough arguments for that many stripes ? |
| 144 | */ |
| 145 | if (argc != (2 + 2 * stripes)) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 146 | ti->error = "Not enough destinations " |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | "specified"; |
| 148 | return -EINVAL; |
| 149 | } |
| 150 | |
| 151 | sc = alloc_context(stripes); |
| 152 | if (!sc) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 153 | ti->error = "Memory allocation for striped context " |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | "failed"; |
| 155 | return -ENOMEM; |
| 156 | } |
| 157 | |
Tejun Heo | f521f07 | 2011-01-13 19:59:57 +0000 | [diff] [blame] | 158 | INIT_WORK(&sc->trigger_event, trigger_event); |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 159 | |
| 160 | /* Set pointer to dm target; used in trigger_event */ |
| 161 | sc->ti = ti; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | sc->stripes = stripes; |
| 163 | sc->stripe_width = width; |
Mikulas Patocka | c96053b | 2010-08-12 04:14:21 +0100 | [diff] [blame] | 164 | |
| 165 | if (stripes & (stripes - 1)) |
| 166 | sc->stripes_shift = -1; |
| 167 | else { |
| 168 | sc->stripes_shift = ffs(stripes) - 1; |
| 169 | sc->stripes_mask = ((sector_t) stripes) - 1; |
| 170 | } |
| 171 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 172 | ti->split_io = chunk_size; |
Mikulas Patocka | 374bf7e | 2009-06-22 10:12:22 +0100 | [diff] [blame] | 173 | ti->num_flush_requests = stripes; |
Mikulas Patocka | 7b76ec1 | 2010-08-12 04:14:26 +0100 | [diff] [blame] | 174 | ti->num_discard_requests = stripes; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | |
Mikulas Patocka | c96053b | 2010-08-12 04:14:21 +0100 | [diff] [blame] | 176 | sc->chunk_shift = ffs(chunk_size) - 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | sc->chunk_mask = ((sector_t) chunk_size) - 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | |
| 179 | /* |
| 180 | * Get the stripe destinations. |
| 181 | */ |
| 182 | for (i = 0; i < stripes; i++) { |
| 183 | argv += 2; |
| 184 | |
| 185 | r = get_stripe(ti, sc, i, argv); |
| 186 | if (r < 0) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 187 | ti->error = "Couldn't parse stripe destination"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | while (i--) |
| 189 | dm_put_device(ti, sc->stripe[i].dev); |
| 190 | kfree(sc); |
| 191 | return r; |
| 192 | } |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 193 | atomic_set(&(sc->stripe[i].error_count), 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 194 | } |
| 195 | |
| 196 | ti->private = sc; |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 197 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | return 0; |
| 199 | } |
| 200 | |
| 201 | static void stripe_dtr(struct dm_target *ti) |
| 202 | { |
| 203 | unsigned int i; |
| 204 | struct stripe_c *sc = (struct stripe_c *) ti->private; |
| 205 | |
| 206 | for (i = 0; i < sc->stripes; i++) |
| 207 | dm_put_device(ti, sc->stripe[i].dev); |
| 208 | |
Tejun Heo | f521f07 | 2011-01-13 19:59:57 +0000 | [diff] [blame] | 209 | flush_work_sync(&sc->trigger_event); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 210 | kfree(sc); |
| 211 | } |
| 212 | |
Mikulas Patocka | 6598852 | 2010-08-12 04:14:14 +0100 | [diff] [blame] | 213 | static void stripe_map_sector(struct stripe_c *sc, sector_t sector, |
| 214 | uint32_t *stripe, sector_t *result) |
| 215 | { |
| 216 | sector_t offset = dm_target_offset(sc->ti, sector); |
| 217 | sector_t chunk = offset >> sc->chunk_shift; |
| 218 | |
Mikulas Patocka | c96053b | 2010-08-12 04:14:21 +0100 | [diff] [blame] | 219 | if (sc->stripes_shift < 0) |
| 220 | *stripe = sector_div(chunk, sc->stripes); |
| 221 | else { |
| 222 | *stripe = chunk & sc->stripes_mask; |
| 223 | chunk >>= sc->stripes_shift; |
| 224 | } |
| 225 | |
Mikulas Patocka | 6598852 | 2010-08-12 04:14:14 +0100 | [diff] [blame] | 226 | *result = (chunk << sc->chunk_shift) | (offset & sc->chunk_mask); |
| 227 | } |
| 228 | |
Mikulas Patocka | 7b76ec1 | 2010-08-12 04:14:26 +0100 | [diff] [blame] | 229 | static void stripe_map_range_sector(struct stripe_c *sc, sector_t sector, |
| 230 | uint32_t target_stripe, sector_t *result) |
| 231 | { |
| 232 | uint32_t stripe; |
| 233 | |
| 234 | stripe_map_sector(sc, sector, &stripe, result); |
| 235 | if (stripe == target_stripe) |
| 236 | return; |
| 237 | *result &= ~sc->chunk_mask; /* round down */ |
| 238 | if (target_stripe < stripe) |
| 239 | *result += sc->chunk_mask + 1; /* next chunk */ |
| 240 | } |
| 241 | |
| 242 | static int stripe_map_discard(struct stripe_c *sc, struct bio *bio, |
| 243 | uint32_t target_stripe) |
| 244 | { |
| 245 | sector_t begin, end; |
| 246 | |
| 247 | stripe_map_range_sector(sc, bio->bi_sector, target_stripe, &begin); |
| 248 | stripe_map_range_sector(sc, bio->bi_sector + bio_sectors(bio), |
| 249 | target_stripe, &end); |
| 250 | if (begin < end) { |
| 251 | bio->bi_bdev = sc->stripe[target_stripe].dev->bdev; |
| 252 | bio->bi_sector = begin + sc->stripe[target_stripe].physical_start; |
| 253 | bio->bi_size = to_bytes(end - begin); |
| 254 | return DM_MAPIO_REMAPPED; |
| 255 | } else { |
| 256 | /* The range doesn't map to the target stripe */ |
| 257 | bio_endio(bio, 0); |
| 258 | return DM_MAPIO_SUBMITTED; |
| 259 | } |
| 260 | } |
| 261 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | static int stripe_map(struct dm_target *ti, struct bio *bio, |
| 263 | union map_info *map_context) |
| 264 | { |
Mikulas Patocka | 6598852 | 2010-08-12 04:14:14 +0100 | [diff] [blame] | 265 | struct stripe_c *sc = ti->private; |
Mikulas Patocka | 374bf7e | 2009-06-22 10:12:22 +0100 | [diff] [blame] | 266 | uint32_t stripe; |
Mike Snitzer | 57cba5d | 2010-08-12 04:14:04 +0100 | [diff] [blame] | 267 | unsigned target_request_nr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | |
Tejun Heo | d87f4c1 | 2010-09-03 11:56:19 +0200 | [diff] [blame] | 269 | if (bio->bi_rw & REQ_FLUSH) { |
Mike Snitzer | 57cba5d | 2010-08-12 04:14:04 +0100 | [diff] [blame] | 270 | target_request_nr = map_context->target_request_nr; |
| 271 | BUG_ON(target_request_nr >= sc->stripes); |
| 272 | bio->bi_bdev = sc->stripe[target_request_nr].dev->bdev; |
Mikulas Patocka | 374bf7e | 2009-06-22 10:12:22 +0100 | [diff] [blame] | 273 | return DM_MAPIO_REMAPPED; |
| 274 | } |
Mikulas Patocka | 7b76ec1 | 2010-08-12 04:14:26 +0100 | [diff] [blame] | 275 | if (unlikely(bio->bi_rw & REQ_DISCARD)) { |
| 276 | target_request_nr = map_context->target_request_nr; |
| 277 | BUG_ON(target_request_nr >= sc->stripes); |
| 278 | return stripe_map_discard(sc, bio, target_request_nr); |
| 279 | } |
Mikulas Patocka | 374bf7e | 2009-06-22 10:12:22 +0100 | [diff] [blame] | 280 | |
Mikulas Patocka | 6598852 | 2010-08-12 04:14:14 +0100 | [diff] [blame] | 281 | stripe_map_sector(sc, bio->bi_sector, &stripe, &bio->bi_sector); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 282 | |
Mikulas Patocka | 6598852 | 2010-08-12 04:14:14 +0100 | [diff] [blame] | 283 | bio->bi_sector += sc->stripe[stripe].physical_start; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | bio->bi_bdev = sc->stripe[stripe].dev->bdev; |
Mikulas Patocka | 6598852 | 2010-08-12 04:14:14 +0100 | [diff] [blame] | 285 | |
Kiyoshi Ueda | d2a7ad2 | 2006-12-08 02:41:06 -0800 | [diff] [blame] | 286 | return DM_MAPIO_REMAPPED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 287 | } |
| 288 | |
Brian Wood | 4f7f5c6 | 2008-02-08 02:11:24 +0000 | [diff] [blame] | 289 | /* |
| 290 | * Stripe status: |
| 291 | * |
| 292 | * INFO |
| 293 | * #stripes [stripe_name <stripe_name>] [group word count] |
| 294 | * [error count 'A|D' <error count 'A|D'>] |
| 295 | * |
| 296 | * TABLE |
| 297 | * #stripes [stripe chunk size] |
| 298 | * [stripe_name physical_start <stripe_name physical_start>] |
| 299 | * |
| 300 | */ |
| 301 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 302 | static int stripe_status(struct dm_target *ti, |
| 303 | status_type_t type, char *result, unsigned int maxlen) |
| 304 | { |
| 305 | struct stripe_c *sc = (struct stripe_c *) ti->private; |
Brian Wood | 4f7f5c6 | 2008-02-08 02:11:24 +0000 | [diff] [blame] | 306 | char buffer[sc->stripes + 1]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | unsigned int sz = 0; |
| 308 | unsigned int i; |
| 309 | |
| 310 | switch (type) { |
| 311 | case STATUSTYPE_INFO: |
Brian Wood | 4f7f5c6 | 2008-02-08 02:11:24 +0000 | [diff] [blame] | 312 | DMEMIT("%d ", sc->stripes); |
| 313 | for (i = 0; i < sc->stripes; i++) { |
| 314 | DMEMIT("%s ", sc->stripe[i].dev->name); |
| 315 | buffer[i] = atomic_read(&(sc->stripe[i].error_count)) ? |
| 316 | 'D' : 'A'; |
| 317 | } |
| 318 | buffer[i] = '\0'; |
| 319 | DMEMIT("1 %s", buffer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 320 | break; |
| 321 | |
| 322 | case STATUSTYPE_TABLE: |
Andrew Morton | 4ee218c | 2006-03-27 01:17:48 -0800 | [diff] [blame] | 323 | DMEMIT("%d %llu", sc->stripes, |
| 324 | (unsigned long long)sc->chunk_mask + 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 325 | for (i = 0; i < sc->stripes; i++) |
Andrew Morton | 4ee218c | 2006-03-27 01:17:48 -0800 | [diff] [blame] | 326 | DMEMIT(" %s %llu", sc->stripe[i].dev->name, |
| 327 | (unsigned long long)sc->stripe[i].physical_start); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | break; |
| 329 | } |
| 330 | return 0; |
| 331 | } |
| 332 | |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 333 | static int stripe_end_io(struct dm_target *ti, struct bio *bio, |
| 334 | int error, union map_info *map_context) |
| 335 | { |
| 336 | unsigned i; |
| 337 | char major_minor[16]; |
| 338 | struct stripe_c *sc = ti->private; |
| 339 | |
| 340 | if (!error) |
| 341 | return 0; /* I/O complete */ |
| 342 | |
Christoph Hellwig | 7b6d91d | 2010-08-07 18:20:39 +0200 | [diff] [blame] | 343 | if ((error == -EWOULDBLOCK) && (bio->bi_rw & REQ_RAHEAD)) |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 344 | return error; |
| 345 | |
| 346 | if (error == -EOPNOTSUPP) |
| 347 | return error; |
| 348 | |
| 349 | memset(major_minor, 0, sizeof(major_minor)); |
| 350 | sprintf(major_minor, "%d:%d", |
Tejun Heo | f331c02 | 2008-09-03 09:01:48 +0200 | [diff] [blame] | 351 | MAJOR(disk_devt(bio->bi_bdev->bd_disk)), |
| 352 | MINOR(disk_devt(bio->bi_bdev->bd_disk))); |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 353 | |
| 354 | /* |
| 355 | * Test to see which stripe drive triggered the event |
| 356 | * and increment error count for all stripes on that device. |
| 357 | * If the error count for a given device exceeds the threshold |
| 358 | * value we will no longer trigger any further events. |
| 359 | */ |
| 360 | for (i = 0; i < sc->stripes; i++) |
| 361 | if (!strcmp(sc->stripe[i].dev->name, major_minor)) { |
| 362 | atomic_inc(&(sc->stripe[i].error_count)); |
| 363 | if (atomic_read(&(sc->stripe[i].error_count)) < |
| 364 | DM_IO_ERROR_THRESHOLD) |
Tejun Heo | f521f07 | 2011-01-13 19:59:57 +0000 | [diff] [blame] | 365 | schedule_work(&sc->trigger_event); |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 366 | } |
| 367 | |
| 368 | return error; |
| 369 | } |
| 370 | |
Mike Snitzer | af4874e | 2009-06-22 10:12:33 +0100 | [diff] [blame] | 371 | static int stripe_iterate_devices(struct dm_target *ti, |
| 372 | iterate_devices_callout_fn fn, void *data) |
| 373 | { |
| 374 | struct stripe_c *sc = ti->private; |
| 375 | int ret = 0; |
| 376 | unsigned i = 0; |
| 377 | |
Mike Snitzer | 5dea271 | 2009-07-23 20:30:42 +0100 | [diff] [blame] | 378 | do { |
Mike Snitzer | af4874e | 2009-06-22 10:12:33 +0100 | [diff] [blame] | 379 | ret = fn(ti, sc->stripe[i].dev, |
Mike Snitzer | 5dea271 | 2009-07-23 20:30:42 +0100 | [diff] [blame] | 380 | sc->stripe[i].physical_start, |
| 381 | sc->stripe_width, data); |
| 382 | } while (!ret && ++i < sc->stripes); |
Mike Snitzer | af4874e | 2009-06-22 10:12:33 +0100 | [diff] [blame] | 383 | |
| 384 | return ret; |
| 385 | } |
| 386 | |
Mike Snitzer | 40bea43 | 2009-09-04 20:40:25 +0100 | [diff] [blame] | 387 | static void stripe_io_hints(struct dm_target *ti, |
| 388 | struct queue_limits *limits) |
| 389 | { |
| 390 | struct stripe_c *sc = ti->private; |
| 391 | unsigned chunk_size = (sc->chunk_mask + 1) << 9; |
| 392 | |
| 393 | blk_limits_io_min(limits, chunk_size); |
Martin K. Petersen | 3c5820c | 2009-09-11 21:54:52 +0200 | [diff] [blame] | 394 | blk_limits_io_opt(limits, chunk_size * sc->stripes); |
Mike Snitzer | 40bea43 | 2009-09-04 20:40:25 +0100 | [diff] [blame] | 395 | } |
| 396 | |
Mustafa Mesanovic | 2991520 | 2011-03-24 13:54:35 +0000 | [diff] [blame] | 397 | static int stripe_merge(struct dm_target *ti, struct bvec_merge_data *bvm, |
| 398 | struct bio_vec *biovec, int max_size) |
| 399 | { |
| 400 | struct stripe_c *sc = ti->private; |
| 401 | sector_t bvm_sector = bvm->bi_sector; |
| 402 | uint32_t stripe; |
| 403 | struct request_queue *q; |
| 404 | |
| 405 | stripe_map_sector(sc, bvm_sector, &stripe, &bvm_sector); |
| 406 | |
| 407 | q = bdev_get_queue(sc->stripe[stripe].dev->bdev); |
| 408 | if (!q->merge_bvec_fn) |
| 409 | return max_size; |
| 410 | |
| 411 | bvm->bi_bdev = sc->stripe[stripe].dev->bdev; |
| 412 | bvm->bi_sector = sc->stripe[stripe].physical_start + bvm_sector; |
| 413 | |
| 414 | return min(max_size, q->merge_bvec_fn(q, bvm, biovec)); |
| 415 | } |
| 416 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | static struct target_type stripe_target = { |
| 418 | .name = "striped", |
Mustafa Mesanovic | 2991520 | 2011-03-24 13:54:35 +0000 | [diff] [blame] | 419 | .version = {1, 4, 0}, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 420 | .module = THIS_MODULE, |
| 421 | .ctr = stripe_ctr, |
| 422 | .dtr = stripe_dtr, |
| 423 | .map = stripe_map, |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 424 | .end_io = stripe_end_io, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 425 | .status = stripe_status, |
Mike Snitzer | af4874e | 2009-06-22 10:12:33 +0100 | [diff] [blame] | 426 | .iterate_devices = stripe_iterate_devices, |
Mike Snitzer | 40bea43 | 2009-09-04 20:40:25 +0100 | [diff] [blame] | 427 | .io_hints = stripe_io_hints, |
Mustafa Mesanovic | 2991520 | 2011-03-24 13:54:35 +0000 | [diff] [blame] | 428 | .merge = stripe_merge, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | }; |
| 430 | |
| 431 | int __init dm_stripe_init(void) |
| 432 | { |
| 433 | int r; |
| 434 | |
| 435 | r = dm_register_target(&stripe_target); |
Heinz Mauelshagen | 6edebde | 2008-11-13 23:38:56 +0000 | [diff] [blame] | 436 | if (r < 0) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 437 | DMWARN("target registration failed"); |
Heinz Mauelshagen | 6edebde | 2008-11-13 23:38:56 +0000 | [diff] [blame] | 438 | return r; |
| 439 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | |
| 441 | return r; |
| 442 | } |
| 443 | |
| 444 | void dm_stripe_exit(void) |
| 445 | { |
Mikulas Patocka | 10d3bd0 | 2009-01-06 03:04:58 +0000 | [diff] [blame] | 446 | dm_unregister_target(&stripe_target); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 447 | } |