Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2003 Sistina Software (UK) Limited. |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 3 | * Copyright (C) 2004, 2010-2011 Red Hat, Inc. All rights reserved. |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 4 | * |
| 5 | * This file is released under the GPL. |
| 6 | */ |
| 7 | |
| 8 | #include <linux/device-mapper.h> |
| 9 | |
| 10 | #include <linux/module.h> |
| 11 | #include <linux/init.h> |
| 12 | #include <linux/blkdev.h> |
| 13 | #include <linux/bio.h> |
| 14 | #include <linux/slab.h> |
| 15 | |
| 16 | #define DM_MSG_PREFIX "flakey" |
| 17 | |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 18 | #define all_corrupt_bio_flags_match(bio, fc) \ |
| 19 | (((bio)->bi_rw & (fc)->corrupt_bio_flags) == (fc)->corrupt_bio_flags) |
| 20 | |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 21 | /* |
| 22 | * Flakey: Used for testing only, simulates intermittent, |
| 23 | * catastrophic device failure. |
| 24 | */ |
| 25 | struct flakey_c { |
| 26 | struct dm_dev *dev; |
| 27 | unsigned long start_time; |
| 28 | sector_t start; |
| 29 | unsigned up_interval; |
| 30 | unsigned down_interval; |
Mike Snitzer | b26f5e3 | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 31 | unsigned long flags; |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 32 | unsigned corrupt_bio_byte; |
| 33 | unsigned corrupt_bio_rw; |
| 34 | unsigned corrupt_bio_value; |
| 35 | unsigned corrupt_bio_flags; |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 36 | }; |
| 37 | |
Mike Snitzer | b26f5e3 | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 38 | enum feature_flag_bits { |
| 39 | DROP_WRITES |
| 40 | }; |
| 41 | |
| 42 | static int parse_features(struct dm_arg_set *as, struct flakey_c *fc, |
| 43 | struct dm_target *ti) |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 44 | { |
| 45 | int r; |
| 46 | unsigned argc; |
| 47 | const char *arg_name; |
| 48 | |
| 49 | static struct dm_arg _args[] = { |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 50 | {0, 6, "Invalid number of feature args"}, |
| 51 | {1, UINT_MAX, "Invalid corrupt bio byte"}, |
| 52 | {0, 255, "Invalid corrupt value to write into bio byte (0-255)"}, |
| 53 | {0, UINT_MAX, "Invalid corrupt bio flags mask"}, |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 54 | }; |
| 55 | |
| 56 | /* No feature arguments supplied. */ |
| 57 | if (!as->argc) |
| 58 | return 0; |
| 59 | |
| 60 | r = dm_read_arg_group(_args, as, &argc, &ti->error); |
| 61 | if (r) |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 62 | return r; |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 63 | |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 64 | while (argc) { |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 65 | arg_name = dm_shift_arg(as); |
| 66 | argc--; |
| 67 | |
Mike Snitzer | b26f5e3 | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 68 | /* |
| 69 | * drop_writes |
| 70 | */ |
| 71 | if (!strcasecmp(arg_name, "drop_writes")) { |
| 72 | if (test_and_set_bit(DROP_WRITES, &fc->flags)) { |
| 73 | ti->error = "Feature drop_writes duplicated"; |
| 74 | return -EINVAL; |
| 75 | } |
| 76 | |
| 77 | continue; |
| 78 | } |
| 79 | |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 80 | /* |
| 81 | * corrupt_bio_byte <Nth_byte> <direction> <value> <bio_flags> |
| 82 | */ |
| 83 | if (!strcasecmp(arg_name, "corrupt_bio_byte")) { |
Mike Snitzer | 68e58a2 | 2011-09-25 23:26:15 +0100 | [diff] [blame] | 84 | if (!argc) { |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 85 | ti->error = "Feature corrupt_bio_byte requires parameters"; |
Mike Snitzer | 68e58a2 | 2011-09-25 23:26:15 +0100 | [diff] [blame] | 86 | return -EINVAL; |
| 87 | } |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 88 | |
| 89 | r = dm_read_arg(_args + 1, as, &fc->corrupt_bio_byte, &ti->error); |
| 90 | if (r) |
| 91 | return r; |
| 92 | argc--; |
| 93 | |
| 94 | /* |
| 95 | * Direction r or w? |
| 96 | */ |
| 97 | arg_name = dm_shift_arg(as); |
| 98 | if (!strcasecmp(arg_name, "w")) |
| 99 | fc->corrupt_bio_rw = WRITE; |
| 100 | else if (!strcasecmp(arg_name, "r")) |
| 101 | fc->corrupt_bio_rw = READ; |
| 102 | else { |
| 103 | ti->error = "Invalid corrupt bio direction (r or w)"; |
| 104 | return -EINVAL; |
| 105 | } |
| 106 | argc--; |
| 107 | |
| 108 | /* |
| 109 | * Value of byte (0-255) to write in place of correct one. |
| 110 | */ |
| 111 | r = dm_read_arg(_args + 2, as, &fc->corrupt_bio_value, &ti->error); |
| 112 | if (r) |
| 113 | return r; |
| 114 | argc--; |
| 115 | |
| 116 | /* |
| 117 | * Only corrupt bios with these flags set. |
| 118 | */ |
| 119 | r = dm_read_arg(_args + 3, as, &fc->corrupt_bio_flags, &ti->error); |
| 120 | if (r) |
| 121 | return r; |
| 122 | argc--; |
| 123 | |
| 124 | continue; |
| 125 | } |
| 126 | |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 127 | ti->error = "Unrecognised flakey feature requested"; |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 128 | return -EINVAL; |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 129 | } |
| 130 | |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 131 | if (test_bit(DROP_WRITES, &fc->flags) && (fc->corrupt_bio_rw == WRITE)) { |
| 132 | ti->error = "drop_writes is incompatible with corrupt_bio_byte with the WRITE flag set"; |
| 133 | return -EINVAL; |
| 134 | } |
| 135 | |
| 136 | return 0; |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 137 | } |
| 138 | |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 139 | /* |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 140 | * Construct a flakey mapping: |
| 141 | * <dev_path> <offset> <up interval> <down interval> [<#feature args> [<arg>]*] |
Mike Snitzer | b26f5e3 | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 142 | * |
| 143 | * Feature args: |
| 144 | * [drop_writes] |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 145 | * [corrupt_bio_byte <Nth_byte> <direction> <value> <bio_flags>] |
| 146 | * |
| 147 | * Nth_byte starts from 1 for the first byte. |
| 148 | * Direction is r for READ or w for WRITE. |
| 149 | * bio_flags is ignored if 0. |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 150 | */ |
| 151 | static int flakey_ctr(struct dm_target *ti, unsigned int argc, char **argv) |
| 152 | { |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 153 | static struct dm_arg _args[] = { |
| 154 | {0, UINT_MAX, "Invalid up interval"}, |
| 155 | {0, UINT_MAX, "Invalid down interval"}, |
| 156 | }; |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 157 | |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 158 | int r; |
| 159 | struct flakey_c *fc; |
| 160 | unsigned long long tmpll; |
| 161 | struct dm_arg_set as; |
| 162 | const char *devname; |
| 163 | |
| 164 | as.argc = argc; |
| 165 | as.argv = argv; |
| 166 | |
| 167 | if (argc < 4) { |
| 168 | ti->error = "Invalid argument count"; |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 169 | return -EINVAL; |
| 170 | } |
| 171 | |
Mike Snitzer | b26f5e3 | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 172 | fc = kzalloc(sizeof(*fc), GFP_KERNEL); |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 173 | if (!fc) { |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 174 | ti->error = "Cannot allocate linear context"; |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 175 | return -ENOMEM; |
| 176 | } |
| 177 | fc->start_time = jiffies; |
| 178 | |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 179 | devname = dm_shift_arg(&as); |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 180 | |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 181 | if (sscanf(dm_shift_arg(&as), "%llu", &tmpll) != 1) { |
| 182 | ti->error = "Invalid device sector"; |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 183 | goto bad; |
| 184 | } |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 185 | fc->start = tmpll; |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 186 | |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 187 | r = dm_read_arg(_args, &as, &fc->up_interval, &ti->error); |
| 188 | if (r) |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 189 | goto bad; |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 190 | |
| 191 | r = dm_read_arg(_args, &as, &fc->down_interval, &ti->error); |
| 192 | if (r) |
| 193 | goto bad; |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 194 | |
| 195 | if (!(fc->up_interval + fc->down_interval)) { |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 196 | ti->error = "Total (up + down) interval is zero"; |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 197 | goto bad; |
| 198 | } |
| 199 | |
| 200 | if (fc->up_interval + fc->down_interval < fc->up_interval) { |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 201 | ti->error = "Interval overflow"; |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 202 | goto bad; |
| 203 | } |
| 204 | |
Mike Snitzer | b26f5e3 | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 205 | r = parse_features(&as, fc, ti); |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 206 | if (r) |
| 207 | goto bad; |
| 208 | |
| 209 | if (dm_get_device(ti, devname, dm_table_get_mode(ti->table), &fc->dev)) { |
| 210 | ti->error = "Device lookup failed"; |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 211 | goto bad; |
| 212 | } |
| 213 | |
| 214 | ti->num_flush_requests = 1; |
Mike Snitzer | 30e4171 | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 215 | ti->num_discard_requests = 1; |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 216 | ti->private = fc; |
| 217 | return 0; |
| 218 | |
| 219 | bad: |
| 220 | kfree(fc); |
| 221 | return -EINVAL; |
| 222 | } |
| 223 | |
| 224 | static void flakey_dtr(struct dm_target *ti) |
| 225 | { |
| 226 | struct flakey_c *fc = ti->private; |
| 227 | |
| 228 | dm_put_device(ti, fc->dev); |
| 229 | kfree(fc); |
| 230 | } |
| 231 | |
| 232 | static sector_t flakey_map_sector(struct dm_target *ti, sector_t bi_sector) |
| 233 | { |
| 234 | struct flakey_c *fc = ti->private; |
| 235 | |
Mike Snitzer | 30e4171 | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 236 | return fc->start + dm_target_offset(ti, bi_sector); |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 237 | } |
| 238 | |
| 239 | static void flakey_map_bio(struct dm_target *ti, struct bio *bio) |
| 240 | { |
| 241 | struct flakey_c *fc = ti->private; |
| 242 | |
| 243 | bio->bi_bdev = fc->dev->bdev; |
| 244 | if (bio_sectors(bio)) |
| 245 | bio->bi_sector = flakey_map_sector(ti, bio->bi_sector); |
| 246 | } |
| 247 | |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 248 | static void corrupt_bio_data(struct bio *bio, struct flakey_c *fc) |
| 249 | { |
| 250 | unsigned bio_bytes = bio_cur_bytes(bio); |
| 251 | char *data = bio_data(bio); |
| 252 | |
| 253 | /* |
| 254 | * Overwrite the Nth byte of the data returned. |
| 255 | */ |
| 256 | if (data && bio_bytes >= fc->corrupt_bio_byte) { |
| 257 | data[fc->corrupt_bio_byte - 1] = fc->corrupt_bio_value; |
| 258 | |
| 259 | DMDEBUG("Corrupting data bio=%p by writing %u to byte %u " |
| 260 | "(rw=%c bi_rw=%lu bi_sector=%llu cur_bytes=%u)\n", |
| 261 | bio, fc->corrupt_bio_value, fc->corrupt_bio_byte, |
| 262 | (bio_data_dir(bio) == WRITE) ? 'w' : 'r', |
| 263 | bio->bi_rw, (unsigned long long)bio->bi_sector, bio_bytes); |
| 264 | } |
| 265 | } |
| 266 | |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 267 | static int flakey_map(struct dm_target *ti, struct bio *bio, |
| 268 | union map_info *map_context) |
| 269 | { |
| 270 | struct flakey_c *fc = ti->private; |
| 271 | unsigned elapsed; |
| 272 | |
| 273 | /* Are we alive ? */ |
| 274 | elapsed = (jiffies - fc->start_time) / HZ; |
Mike Snitzer | b26f5e3 | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 275 | if (elapsed % (fc->up_interval + fc->down_interval) >= fc->up_interval) { |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 276 | /* |
| 277 | * Flag this bio as submitted while down. |
| 278 | */ |
| 279 | map_context->ll = 1; |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 280 | |
Mike Snitzer | b26f5e3 | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 281 | /* |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 282 | * Map reads as normal. |
| 283 | */ |
| 284 | if (bio_data_dir(bio) == READ) |
| 285 | goto map_bio; |
| 286 | |
| 287 | /* |
| 288 | * Drop writes? |
Mike Snitzer | b26f5e3 | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 289 | */ |
| 290 | if (test_bit(DROP_WRITES, &fc->flags)) { |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 291 | bio_endio(bio, 0); |
| 292 | return DM_MAPIO_SUBMITTED; |
| 293 | } |
| 294 | |
| 295 | /* |
| 296 | * Corrupt matching writes. |
| 297 | */ |
| 298 | if (fc->corrupt_bio_byte && (fc->corrupt_bio_rw == WRITE)) { |
| 299 | if (all_corrupt_bio_flags_match(bio, fc)) |
| 300 | corrupt_bio_data(bio, fc); |
Mike Snitzer | b26f5e3 | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 301 | goto map_bio; |
| 302 | } |
| 303 | |
| 304 | /* |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 305 | * By default, error all I/O. |
Mike Snitzer | b26f5e3 | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 306 | */ |
| 307 | return -EIO; |
| 308 | } |
| 309 | |
| 310 | map_bio: |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 311 | flakey_map_bio(ti, bio); |
| 312 | |
| 313 | return DM_MAPIO_REMAPPED; |
| 314 | } |
| 315 | |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 316 | static int flakey_end_io(struct dm_target *ti, struct bio *bio, |
| 317 | int error, union map_info *map_context) |
| 318 | { |
| 319 | struct flakey_c *fc = ti->private; |
| 320 | unsigned bio_submitted_while_down = map_context->ll; |
| 321 | |
| 322 | /* |
| 323 | * Corrupt successful READs while in down state. |
| 324 | * If flags were specified, only corrupt those that match. |
| 325 | */ |
Mike Snitzer | 1212268 | 2012-03-07 19:09:39 +0000 | [diff] [blame] | 326 | if (fc->corrupt_bio_byte && !error && bio_submitted_while_down && |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 327 | (bio_data_dir(bio) == READ) && (fc->corrupt_bio_rw == READ) && |
| 328 | all_corrupt_bio_flags_match(bio, fc)) |
| 329 | corrupt_bio_data(bio, fc); |
| 330 | |
| 331 | return error; |
| 332 | } |
| 333 | |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 334 | static int flakey_status(struct dm_target *ti, status_type_t type, |
| 335 | char *result, unsigned int maxlen) |
| 336 | { |
Mike Snitzer | b26f5e3 | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 337 | unsigned sz = 0; |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 338 | struct flakey_c *fc = ti->private; |
Mike Snitzer | b26f5e3 | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 339 | unsigned drop_writes; |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 340 | |
| 341 | switch (type) { |
| 342 | case STATUSTYPE_INFO: |
| 343 | result[0] = '\0'; |
| 344 | break; |
| 345 | |
| 346 | case STATUSTYPE_TABLE: |
Mike Snitzer | b26f5e3 | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 347 | DMEMIT("%s %llu %u %u ", fc->dev->name, |
| 348 | (unsigned long long)fc->start, fc->up_interval, |
| 349 | fc->down_interval); |
| 350 | |
| 351 | drop_writes = test_bit(DROP_WRITES, &fc->flags); |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 352 | DMEMIT("%u ", drop_writes + (fc->corrupt_bio_byte > 0) * 5); |
| 353 | |
Mike Snitzer | b26f5e3 | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 354 | if (drop_writes) |
| 355 | DMEMIT("drop_writes "); |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 356 | |
| 357 | if (fc->corrupt_bio_byte) |
| 358 | DMEMIT("corrupt_bio_byte %u %c %u %u ", |
| 359 | fc->corrupt_bio_byte, |
| 360 | (fc->corrupt_bio_rw == WRITE) ? 'w' : 'r', |
| 361 | fc->corrupt_bio_value, fc->corrupt_bio_flags); |
| 362 | |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 363 | break; |
| 364 | } |
| 365 | return 0; |
| 366 | } |
| 367 | |
| 368 | static int flakey_ioctl(struct dm_target *ti, unsigned int cmd, unsigned long arg) |
| 369 | { |
| 370 | struct flakey_c *fc = ti->private; |
Paolo Bonzini | ec8013b | 2012-01-12 16:01:29 +0100 | [diff] [blame] | 371 | struct dm_dev *dev = fc->dev; |
| 372 | int r = 0; |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 373 | |
Paolo Bonzini | ec8013b | 2012-01-12 16:01:29 +0100 | [diff] [blame] | 374 | /* |
| 375 | * Only pass ioctls through if the device sizes match exactly. |
| 376 | */ |
| 377 | if (fc->start || |
| 378 | ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT) |
| 379 | r = scsi_verify_blk_ioctl(NULL, cmd); |
| 380 | |
| 381 | return r ? : __blkdev_driver_ioctl(dev->bdev, dev->mode, cmd, arg); |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 382 | } |
| 383 | |
| 384 | static int flakey_merge(struct dm_target *ti, struct bvec_merge_data *bvm, |
| 385 | struct bio_vec *biovec, int max_size) |
| 386 | { |
| 387 | struct flakey_c *fc = ti->private; |
| 388 | struct request_queue *q = bdev_get_queue(fc->dev->bdev); |
| 389 | |
| 390 | if (!q->merge_bvec_fn) |
| 391 | return max_size; |
| 392 | |
| 393 | bvm->bi_bdev = fc->dev->bdev; |
| 394 | bvm->bi_sector = flakey_map_sector(ti, bvm->bi_sector); |
| 395 | |
| 396 | return min(max_size, q->merge_bvec_fn(q, bvm, biovec)); |
| 397 | } |
| 398 | |
| 399 | static int flakey_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data) |
| 400 | { |
| 401 | struct flakey_c *fc = ti->private; |
| 402 | |
| 403 | return fn(ti, fc->dev, fc->start, ti->len, data); |
| 404 | } |
| 405 | |
| 406 | static struct target_type flakey_target = { |
| 407 | .name = "flakey", |
Mike Snitzer | dfd068b | 2011-08-02 12:32:05 +0100 | [diff] [blame] | 408 | .version = {1, 2, 0}, |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 409 | .module = THIS_MODULE, |
| 410 | .ctr = flakey_ctr, |
| 411 | .dtr = flakey_dtr, |
| 412 | .map = flakey_map, |
Mike Snitzer | a399879 | 2011-08-02 12:32:06 +0100 | [diff] [blame] | 413 | .end_io = flakey_end_io, |
Josef Bacik | 3407ef5 | 2011-03-24 13:54:24 +0000 | [diff] [blame] | 414 | .status = flakey_status, |
| 415 | .ioctl = flakey_ioctl, |
| 416 | .merge = flakey_merge, |
| 417 | .iterate_devices = flakey_iterate_devices, |
| 418 | }; |
| 419 | |
| 420 | static int __init dm_flakey_init(void) |
| 421 | { |
| 422 | int r = dm_register_target(&flakey_target); |
| 423 | |
| 424 | if (r < 0) |
| 425 | DMERR("register failed %d", r); |
| 426 | |
| 427 | return r; |
| 428 | } |
| 429 | |
| 430 | static void __exit dm_flakey_exit(void) |
| 431 | { |
| 432 | dm_unregister_target(&flakey_target); |
| 433 | } |
| 434 | |
| 435 | /* Module hooks */ |
| 436 | module_init(dm_flakey_init); |
| 437 | module_exit(dm_flakey_exit); |
| 438 | |
| 439 | MODULE_DESCRIPTION(DM_NAME " flakey target"); |
| 440 | MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); |
| 441 | MODULE_LICENSE("GPL"); |