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; |
| 28 | |
| 29 | /* The size of this target / num. stripes */ |
| 30 | sector_t stripe_width; |
| 31 | |
| 32 | /* stripe chunk size */ |
| 33 | uint32_t chunk_shift; |
| 34 | sector_t chunk_mask; |
| 35 | |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 36 | /* Needed for handling events */ |
| 37 | struct dm_target *ti; |
| 38 | |
| 39 | /* Work struct used for triggering events*/ |
| 40 | struct work_struct kstriped_ws; |
| 41 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | struct stripe stripe[0]; |
| 43 | }; |
| 44 | |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 45 | static struct workqueue_struct *kstriped; |
| 46 | |
| 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 | { |
| 53 | struct stripe_c *sc = container_of(work, struct stripe_c, kstriped_ws); |
| 54 | |
| 55 | dm_table_event(sc->ti->table); |
| 56 | |
| 57 | } |
| 58 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | static inline struct stripe_c *alloc_context(unsigned int stripes) |
| 60 | { |
| 61 | size_t len; |
| 62 | |
Mikulas Patocka | d63a5ce | 2008-10-21 17:44:57 +0100 | [diff] [blame] | 63 | if (dm_array_too_big(sizeof(struct stripe_c), sizeof(struct stripe), |
| 64 | stripes)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | return NULL; |
| 66 | |
| 67 | len = sizeof(struct stripe_c) + (sizeof(struct stripe) * stripes); |
| 68 | |
| 69 | return kmalloc(len, GFP_KERNEL); |
| 70 | } |
| 71 | |
| 72 | /* |
| 73 | * Parse a single <dev> <sector> pair |
| 74 | */ |
| 75 | static int get_stripe(struct dm_target *ti, struct stripe_c *sc, |
| 76 | unsigned int stripe, char **argv) |
| 77 | { |
Andrew Morton | 4ee218c | 2006-03-27 01:17:48 -0800 | [diff] [blame] | 78 | unsigned long long start; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | |
Andrew Morton | 4ee218c | 2006-03-27 01:17:48 -0800 | [diff] [blame] | 80 | if (sscanf(argv[1], "%llu", &start) != 1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | return -EINVAL; |
| 82 | |
| 83 | if (dm_get_device(ti, argv[0], start, sc->stripe_width, |
| 84 | dm_table_get_mode(ti->table), |
| 85 | &sc->stripe[stripe].dev)) |
| 86 | return -ENXIO; |
| 87 | |
| 88 | sc->stripe[stripe].physical_start = start; |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 89 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | return 0; |
| 91 | } |
| 92 | |
| 93 | /* |
| 94 | * Construct a striped mapping. |
| 95 | * <number of stripes> <chunk size (2^^n)> [<dev_path> <offset>]+ |
| 96 | */ |
| 97 | static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv) |
| 98 | { |
| 99 | struct stripe_c *sc; |
| 100 | sector_t width; |
| 101 | uint32_t stripes; |
| 102 | uint32_t chunk_size; |
| 103 | char *end; |
| 104 | int r; |
| 105 | unsigned int i; |
| 106 | |
| 107 | if (argc < 2) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 108 | ti->error = "Not enough arguments"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | return -EINVAL; |
| 110 | } |
| 111 | |
| 112 | stripes = simple_strtoul(argv[0], &end, 10); |
| 113 | if (*end) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 114 | ti->error = "Invalid stripe count"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | return -EINVAL; |
| 116 | } |
| 117 | |
| 118 | chunk_size = simple_strtoul(argv[1], &end, 10); |
| 119 | if (*end) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 120 | ti->error = "Invalid chunk_size"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | return -EINVAL; |
| 122 | } |
| 123 | |
| 124 | /* |
| 125 | * chunk_size is a power of two |
| 126 | */ |
vignesh babu | 6f3c3f0 | 2007-10-19 22:38:44 +0100 | [diff] [blame] | 127 | if (!is_power_of_2(chunk_size) || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | (chunk_size < (PAGE_SIZE >> SECTOR_SHIFT))) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 129 | ti->error = "Invalid chunk size"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | return -EINVAL; |
| 131 | } |
| 132 | |
Kevin Corry | a22c96c | 2006-03-27 01:18:01 -0800 | [diff] [blame] | 133 | if (ti->len & (chunk_size - 1)) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 134 | ti->error = "Target length not divisible by " |
Kevin Corry | 8ba32fd | 2006-03-16 23:04:03 -0800 | [diff] [blame] | 135 | "chunk size"; |
| 136 | return -EINVAL; |
| 137 | } |
| 138 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | width = ti->len; |
| 140 | if (sector_div(width, stripes)) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 141 | ti->error = "Target length not divisible by " |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | "number of stripes"; |
| 143 | return -EINVAL; |
| 144 | } |
| 145 | |
| 146 | /* |
| 147 | * Do we have enough arguments for that many stripes ? |
| 148 | */ |
| 149 | if (argc != (2 + 2 * stripes)) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 150 | ti->error = "Not enough destinations " |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | "specified"; |
| 152 | return -EINVAL; |
| 153 | } |
| 154 | |
| 155 | sc = alloc_context(stripes); |
| 156 | if (!sc) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 157 | ti->error = "Memory allocation for striped context " |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | "failed"; |
| 159 | return -ENOMEM; |
| 160 | } |
| 161 | |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 162 | INIT_WORK(&sc->kstriped_ws, trigger_event); |
| 163 | |
| 164 | /* Set pointer to dm target; used in trigger_event */ |
| 165 | sc->ti = ti; |
| 166 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | sc->stripes = stripes; |
| 168 | sc->stripe_width = width; |
| 169 | ti->split_io = chunk_size; |
| 170 | |
| 171 | sc->chunk_mask = ((sector_t) chunk_size) - 1; |
| 172 | for (sc->chunk_shift = 0; chunk_size; sc->chunk_shift++) |
| 173 | chunk_size >>= 1; |
| 174 | sc->chunk_shift--; |
| 175 | |
| 176 | /* |
| 177 | * Get the stripe destinations. |
| 178 | */ |
| 179 | for (i = 0; i < stripes; i++) { |
| 180 | argv += 2; |
| 181 | |
| 182 | r = get_stripe(ti, sc, i, argv); |
| 183 | if (r < 0) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 184 | ti->error = "Couldn't parse stripe destination"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 185 | while (i--) |
| 186 | dm_put_device(ti, sc->stripe[i].dev); |
| 187 | kfree(sc); |
| 188 | return r; |
| 189 | } |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 190 | atomic_set(&(sc->stripe[i].error_count), 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | } |
| 192 | |
| 193 | ti->private = sc; |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 194 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | return 0; |
| 196 | } |
| 197 | |
| 198 | static void stripe_dtr(struct dm_target *ti) |
| 199 | { |
| 200 | unsigned int i; |
| 201 | struct stripe_c *sc = (struct stripe_c *) ti->private; |
| 202 | |
| 203 | for (i = 0; i < sc->stripes; i++) |
| 204 | dm_put_device(ti, sc->stripe[i].dev); |
| 205 | |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 206 | flush_workqueue(kstriped); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | kfree(sc); |
| 208 | } |
| 209 | |
| 210 | static int stripe_map(struct dm_target *ti, struct bio *bio, |
| 211 | union map_info *map_context) |
| 212 | { |
| 213 | struct stripe_c *sc = (struct stripe_c *) ti->private; |
| 214 | |
| 215 | sector_t offset = bio->bi_sector - ti->begin; |
| 216 | sector_t chunk = offset >> sc->chunk_shift; |
| 217 | uint32_t stripe = sector_div(chunk, sc->stripes); |
| 218 | |
| 219 | bio->bi_bdev = sc->stripe[stripe].dev->bdev; |
| 220 | bio->bi_sector = sc->stripe[stripe].physical_start + |
| 221 | (chunk << sc->chunk_shift) + (offset & sc->chunk_mask); |
Kiyoshi Ueda | d2a7ad2 | 2006-12-08 02:41:06 -0800 | [diff] [blame] | 222 | return DM_MAPIO_REMAPPED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | } |
| 224 | |
Brian Wood | 4f7f5c6 | 2008-02-08 02:11:24 +0000 | [diff] [blame] | 225 | /* |
| 226 | * Stripe status: |
| 227 | * |
| 228 | * INFO |
| 229 | * #stripes [stripe_name <stripe_name>] [group word count] |
| 230 | * [error count 'A|D' <error count 'A|D'>] |
| 231 | * |
| 232 | * TABLE |
| 233 | * #stripes [stripe chunk size] |
| 234 | * [stripe_name physical_start <stripe_name physical_start>] |
| 235 | * |
| 236 | */ |
| 237 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | static int stripe_status(struct dm_target *ti, |
| 239 | status_type_t type, char *result, unsigned int maxlen) |
| 240 | { |
| 241 | struct stripe_c *sc = (struct stripe_c *) ti->private; |
Brian Wood | 4f7f5c6 | 2008-02-08 02:11:24 +0000 | [diff] [blame] | 242 | char buffer[sc->stripes + 1]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | unsigned int sz = 0; |
| 244 | unsigned int i; |
| 245 | |
| 246 | switch (type) { |
| 247 | case STATUSTYPE_INFO: |
Brian Wood | 4f7f5c6 | 2008-02-08 02:11:24 +0000 | [diff] [blame] | 248 | DMEMIT("%d ", sc->stripes); |
| 249 | for (i = 0; i < sc->stripes; i++) { |
| 250 | DMEMIT("%s ", sc->stripe[i].dev->name); |
| 251 | buffer[i] = atomic_read(&(sc->stripe[i].error_count)) ? |
| 252 | 'D' : 'A'; |
| 253 | } |
| 254 | buffer[i] = '\0'; |
| 255 | DMEMIT("1 %s", buffer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | break; |
| 257 | |
| 258 | case STATUSTYPE_TABLE: |
Andrew Morton | 4ee218c | 2006-03-27 01:17:48 -0800 | [diff] [blame] | 259 | DMEMIT("%d %llu", sc->stripes, |
| 260 | (unsigned long long)sc->chunk_mask + 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 261 | for (i = 0; i < sc->stripes; i++) |
Andrew Morton | 4ee218c | 2006-03-27 01:17:48 -0800 | [diff] [blame] | 262 | DMEMIT(" %s %llu", sc->stripe[i].dev->name, |
| 263 | (unsigned long long)sc->stripe[i].physical_start); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | break; |
| 265 | } |
| 266 | return 0; |
| 267 | } |
| 268 | |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 269 | static int stripe_end_io(struct dm_target *ti, struct bio *bio, |
| 270 | int error, union map_info *map_context) |
| 271 | { |
| 272 | unsigned i; |
| 273 | char major_minor[16]; |
| 274 | struct stripe_c *sc = ti->private; |
| 275 | |
| 276 | if (!error) |
| 277 | return 0; /* I/O complete */ |
| 278 | |
| 279 | if ((error == -EWOULDBLOCK) && bio_rw_ahead(bio)) |
| 280 | return error; |
| 281 | |
| 282 | if (error == -EOPNOTSUPP) |
| 283 | return error; |
| 284 | |
| 285 | memset(major_minor, 0, sizeof(major_minor)); |
| 286 | sprintf(major_minor, "%d:%d", |
Tejun Heo | f331c02 | 2008-09-03 09:01:48 +0200 | [diff] [blame] | 287 | MAJOR(disk_devt(bio->bi_bdev->bd_disk)), |
| 288 | MINOR(disk_devt(bio->bi_bdev->bd_disk))); |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 289 | |
| 290 | /* |
| 291 | * Test to see which stripe drive triggered the event |
| 292 | * and increment error count for all stripes on that device. |
| 293 | * If the error count for a given device exceeds the threshold |
| 294 | * value we will no longer trigger any further events. |
| 295 | */ |
| 296 | for (i = 0; i < sc->stripes; i++) |
| 297 | if (!strcmp(sc->stripe[i].dev->name, major_minor)) { |
| 298 | atomic_inc(&(sc->stripe[i].error_count)); |
| 299 | if (atomic_read(&(sc->stripe[i].error_count)) < |
| 300 | DM_IO_ERROR_THRESHOLD) |
| 301 | queue_work(kstriped, &sc->kstriped_ws); |
| 302 | } |
| 303 | |
| 304 | return error; |
| 305 | } |
| 306 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | static struct target_type stripe_target = { |
| 308 | .name = "striped", |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 309 | .version = {1, 1, 0}, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | .module = THIS_MODULE, |
| 311 | .ctr = stripe_ctr, |
| 312 | .dtr = stripe_dtr, |
| 313 | .map = stripe_map, |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 314 | .end_io = stripe_end_io, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | .status = stripe_status, |
| 316 | }; |
| 317 | |
| 318 | int __init dm_stripe_init(void) |
| 319 | { |
| 320 | int r; |
| 321 | |
| 322 | r = dm_register_target(&stripe_target); |
Heinz Mauelshagen | 6edebde | 2008-11-13 23:38:56 +0000 | [diff] [blame^] | 323 | if (r < 0) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 324 | DMWARN("target registration failed"); |
Heinz Mauelshagen | 6edebde | 2008-11-13 23:38:56 +0000 | [diff] [blame^] | 325 | return r; |
| 326 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 327 | |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 328 | kstriped = create_singlethread_workqueue("kstriped"); |
| 329 | if (!kstriped) { |
| 330 | DMERR("failed to create workqueue kstriped"); |
| 331 | dm_unregister_target(&stripe_target); |
| 332 | return -ENOMEM; |
| 333 | } |
| 334 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | return r; |
| 336 | } |
| 337 | |
| 338 | void dm_stripe_exit(void) |
| 339 | { |
| 340 | if (dm_unregister_target(&stripe_target)) |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 341 | DMWARN("target unregistration failed"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 342 | |
Brian Wood | a25eb94 | 2008-02-08 02:11:22 +0000 | [diff] [blame] | 343 | destroy_workqueue(kstriped); |
| 344 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | return; |
| 346 | } |