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Commit | Line | Data |
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3407ef52 JB |
1 | /* |
2 | * Copyright (C) 2003 Sistina Software (UK) Limited. | |
a3998799 | 3 | * Copyright (C) 2004, 2010-2011 Red Hat, Inc. All rights reserved. |
3407ef52 JB |
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 | ||
a3998799 | 18 | #define all_corrupt_bio_flags_match(bio, fc) \ |
1eff9d32 | 19 | (((bio)->bi_opf & (fc)->corrupt_bio_flags) == (fc)->corrupt_bio_flags) |
a3998799 | 20 | |
3407ef52 JB |
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; | |
b26f5e3d | 31 | unsigned long flags; |
a3998799 MS |
32 | unsigned corrupt_bio_byte; |
33 | unsigned corrupt_bio_rw; | |
34 | unsigned corrupt_bio_value; | |
35 | unsigned corrupt_bio_flags; | |
3407ef52 JB |
36 | }; |
37 | ||
b26f5e3d | 38 | enum feature_flag_bits { |
ef548c55 MS |
39 | DROP_WRITES, |
40 | ERROR_WRITES | |
b26f5e3d MS |
41 | }; |
42 | ||
c7cfdf59 MP |
43 | struct per_bio_data { |
44 | bool bio_submitted; | |
45 | }; | |
46 | ||
b26f5e3d MS |
47 | static int parse_features(struct dm_arg_set *as, struct flakey_c *fc, |
48 | struct dm_target *ti) | |
dfd068b0 MS |
49 | { |
50 | int r; | |
51 | unsigned argc; | |
52 | const char *arg_name; | |
53 | ||
5916a22b | 54 | static const struct dm_arg _args[] = { |
a3998799 MS |
55 | {0, 6, "Invalid number of feature args"}, |
56 | {1, UINT_MAX, "Invalid corrupt bio byte"}, | |
57 | {0, 255, "Invalid corrupt value to write into bio byte (0-255)"}, | |
58 | {0, UINT_MAX, "Invalid corrupt bio flags mask"}, | |
dfd068b0 MS |
59 | }; |
60 | ||
61 | /* No feature arguments supplied. */ | |
62 | if (!as->argc) | |
63 | return 0; | |
64 | ||
65 | r = dm_read_arg_group(_args, as, &argc, &ti->error); | |
66 | if (r) | |
a3998799 | 67 | return r; |
dfd068b0 | 68 | |
a3998799 | 69 | while (argc) { |
dfd068b0 MS |
70 | arg_name = dm_shift_arg(as); |
71 | argc--; | |
72 | ||
7690e253 GR |
73 | if (!arg_name) { |
74 | ti->error = "Insufficient feature arguments"; | |
75 | return -EINVAL; | |
76 | } | |
77 | ||
b26f5e3d MS |
78 | /* |
79 | * drop_writes | |
80 | */ | |
81 | if (!strcasecmp(arg_name, "drop_writes")) { | |
82 | if (test_and_set_bit(DROP_WRITES, &fc->flags)) { | |
83 | ti->error = "Feature drop_writes duplicated"; | |
84 | return -EINVAL; | |
ef548c55 MS |
85 | } else if (test_bit(ERROR_WRITES, &fc->flags)) { |
86 | ti->error = "Feature drop_writes conflicts with feature error_writes"; | |
87 | return -EINVAL; | |
88 | } | |
89 | ||
90 | continue; | |
91 | } | |
92 | ||
93 | /* | |
94 | * error_writes | |
95 | */ | |
96 | if (!strcasecmp(arg_name, "error_writes")) { | |
97 | if (test_and_set_bit(ERROR_WRITES, &fc->flags)) { | |
98 | ti->error = "Feature error_writes duplicated"; | |
99 | return -EINVAL; | |
100 | ||
101 | } else if (test_bit(DROP_WRITES, &fc->flags)) { | |
102 | ti->error = "Feature error_writes conflicts with feature drop_writes"; | |
103 | return -EINVAL; | |
b26f5e3d MS |
104 | } |
105 | ||
106 | continue; | |
107 | } | |
108 | ||
a3998799 MS |
109 | /* |
110 | * corrupt_bio_byte <Nth_byte> <direction> <value> <bio_flags> | |
111 | */ | |
112 | if (!strcasecmp(arg_name, "corrupt_bio_byte")) { | |
68e58a29 | 113 | if (!argc) { |
a3998799 | 114 | ti->error = "Feature corrupt_bio_byte requires parameters"; |
68e58a29 MS |
115 | return -EINVAL; |
116 | } | |
a3998799 MS |
117 | |
118 | r = dm_read_arg(_args + 1, as, &fc->corrupt_bio_byte, &ti->error); | |
119 | if (r) | |
120 | return r; | |
121 | argc--; | |
122 | ||
123 | /* | |
124 | * Direction r or w? | |
125 | */ | |
126 | arg_name = dm_shift_arg(as); | |
127 | if (!strcasecmp(arg_name, "w")) | |
128 | fc->corrupt_bio_rw = WRITE; | |
129 | else if (!strcasecmp(arg_name, "r")) | |
130 | fc->corrupt_bio_rw = READ; | |
131 | else { | |
132 | ti->error = "Invalid corrupt bio direction (r or w)"; | |
133 | return -EINVAL; | |
134 | } | |
135 | argc--; | |
136 | ||
137 | /* | |
138 | * Value of byte (0-255) to write in place of correct one. | |
139 | */ | |
140 | r = dm_read_arg(_args + 2, as, &fc->corrupt_bio_value, &ti->error); | |
141 | if (r) | |
142 | return r; | |
143 | argc--; | |
144 | ||
145 | /* | |
146 | * Only corrupt bios with these flags set. | |
147 | */ | |
148 | r = dm_read_arg(_args + 3, as, &fc->corrupt_bio_flags, &ti->error); | |
149 | if (r) | |
150 | return r; | |
151 | argc--; | |
152 | ||
153 | continue; | |
154 | } | |
155 | ||
dfd068b0 | 156 | ti->error = "Unrecognised flakey feature requested"; |
a3998799 | 157 | return -EINVAL; |
dfd068b0 MS |
158 | } |
159 | ||
a3998799 MS |
160 | if (test_bit(DROP_WRITES, &fc->flags) && (fc->corrupt_bio_rw == WRITE)) { |
161 | ti->error = "drop_writes is incompatible with corrupt_bio_byte with the WRITE flag set"; | |
162 | return -EINVAL; | |
ef548c55 MS |
163 | |
164 | } else if (test_bit(ERROR_WRITES, &fc->flags) && (fc->corrupt_bio_rw == WRITE)) { | |
165 | ti->error = "error_writes is incompatible with corrupt_bio_byte with the WRITE flag set"; | |
166 | return -EINVAL; | |
a3998799 MS |
167 | } |
168 | ||
169 | return 0; | |
dfd068b0 MS |
170 | } |
171 | ||
3407ef52 | 172 | /* |
dfd068b0 MS |
173 | * Construct a flakey mapping: |
174 | * <dev_path> <offset> <up interval> <down interval> [<#feature args> [<arg>]*] | |
b26f5e3d MS |
175 | * |
176 | * Feature args: | |
177 | * [drop_writes] | |
a3998799 MS |
178 | * [corrupt_bio_byte <Nth_byte> <direction> <value> <bio_flags>] |
179 | * | |
180 | * Nth_byte starts from 1 for the first byte. | |
181 | * Direction is r for READ or w for WRITE. | |
182 | * bio_flags is ignored if 0. | |
3407ef52 JB |
183 | */ |
184 | static int flakey_ctr(struct dm_target *ti, unsigned int argc, char **argv) | |
185 | { | |
5916a22b | 186 | static const struct dm_arg _args[] = { |
dfd068b0 MS |
187 | {0, UINT_MAX, "Invalid up interval"}, |
188 | {0, UINT_MAX, "Invalid down interval"}, | |
189 | }; | |
190 | ||
191 | int r; | |
3407ef52 | 192 | struct flakey_c *fc; |
dfd068b0 MS |
193 | unsigned long long tmpll; |
194 | struct dm_arg_set as; | |
195 | const char *devname; | |
31998ef1 | 196 | char dummy; |
3407ef52 | 197 | |
dfd068b0 MS |
198 | as.argc = argc; |
199 | as.argv = argv; | |
200 | ||
201 | if (argc < 4) { | |
202 | ti->error = "Invalid argument count"; | |
3407ef52 JB |
203 | return -EINVAL; |
204 | } | |
205 | ||
b26f5e3d | 206 | fc = kzalloc(sizeof(*fc), GFP_KERNEL); |
3407ef52 | 207 | if (!fc) { |
75e3a0f5 | 208 | ti->error = "Cannot allocate context"; |
3407ef52 JB |
209 | return -ENOMEM; |
210 | } | |
211 | fc->start_time = jiffies; | |
212 | ||
dfd068b0 MS |
213 | devname = dm_shift_arg(&as); |
214 | ||
e80d1c80 | 215 | r = -EINVAL; |
31998ef1 | 216 | if (sscanf(dm_shift_arg(&as), "%llu%c", &tmpll, &dummy) != 1) { |
dfd068b0 | 217 | ti->error = "Invalid device sector"; |
3407ef52 JB |
218 | goto bad; |
219 | } | |
dfd068b0 | 220 | fc->start = tmpll; |
3407ef52 | 221 | |
dfd068b0 MS |
222 | r = dm_read_arg(_args, &as, &fc->up_interval, &ti->error); |
223 | if (r) | |
3407ef52 | 224 | goto bad; |
3407ef52 | 225 | |
dfd068b0 MS |
226 | r = dm_read_arg(_args, &as, &fc->down_interval, &ti->error); |
227 | if (r) | |
3407ef52 | 228 | goto bad; |
3407ef52 JB |
229 | |
230 | if (!(fc->up_interval + fc->down_interval)) { | |
dfd068b0 | 231 | ti->error = "Total (up + down) interval is zero"; |
bff7e067 | 232 | r = -EINVAL; |
3407ef52 JB |
233 | goto bad; |
234 | } | |
235 | ||
236 | if (fc->up_interval + fc->down_interval < fc->up_interval) { | |
dfd068b0 | 237 | ti->error = "Interval overflow"; |
bff7e067 | 238 | r = -EINVAL; |
3407ef52 JB |
239 | goto bad; |
240 | } | |
241 | ||
b26f5e3d | 242 | r = parse_features(&as, fc, ti); |
dfd068b0 MS |
243 | if (r) |
244 | goto bad; | |
245 | ||
e80d1c80 VG |
246 | r = dm_get_device(ti, devname, dm_table_get_mode(ti->table), &fc->dev); |
247 | if (r) { | |
dfd068b0 | 248 | ti->error = "Device lookup failed"; |
3407ef52 JB |
249 | goto bad; |
250 | } | |
251 | ||
55a62eef AK |
252 | ti->num_flush_bios = 1; |
253 | ti->num_discard_bios = 1; | |
30187e1d | 254 | ti->per_io_data_size = sizeof(struct per_bio_data); |
3407ef52 JB |
255 | ti->private = fc; |
256 | return 0; | |
257 | ||
258 | bad: | |
259 | kfree(fc); | |
e80d1c80 | 260 | return r; |
3407ef52 JB |
261 | } |
262 | ||
263 | static void flakey_dtr(struct dm_target *ti) | |
264 | { | |
265 | struct flakey_c *fc = ti->private; | |
266 | ||
267 | dm_put_device(ti, fc->dev); | |
268 | kfree(fc); | |
269 | } | |
270 | ||
271 | static sector_t flakey_map_sector(struct dm_target *ti, sector_t bi_sector) | |
272 | { | |
273 | struct flakey_c *fc = ti->private; | |
274 | ||
30e4171b | 275 | return fc->start + dm_target_offset(ti, bi_sector); |
3407ef52 JB |
276 | } |
277 | ||
278 | static void flakey_map_bio(struct dm_target *ti, struct bio *bio) | |
279 | { | |
280 | struct flakey_c *fc = ti->private; | |
281 | ||
74d46992 | 282 | bio_set_dev(bio, fc->dev->bdev); |
124c4454 | 283 | if (bio_sectors(bio) || bio_op(bio) == REQ_OP_ZONE_RESET) |
4f024f37 KO |
284 | bio->bi_iter.bi_sector = |
285 | flakey_map_sector(ti, bio->bi_iter.bi_sector); | |
3407ef52 JB |
286 | } |
287 | ||
a3998799 MS |
288 | static void corrupt_bio_data(struct bio *bio, struct flakey_c *fc) |
289 | { | |
290 | unsigned bio_bytes = bio_cur_bytes(bio); | |
291 | char *data = bio_data(bio); | |
292 | ||
293 | /* | |
294 | * Overwrite the Nth byte of the data returned. | |
295 | */ | |
296 | if (data && bio_bytes >= fc->corrupt_bio_byte) { | |
297 | data[fc->corrupt_bio_byte - 1] = fc->corrupt_bio_value; | |
298 | ||
299 | DMDEBUG("Corrupting data bio=%p by writing %u to byte %u " | |
1eff9d32 | 300 | "(rw=%c bi_opf=%u bi_sector=%llu cur_bytes=%u)\n", |
a3998799 | 301 | bio, fc->corrupt_bio_value, fc->corrupt_bio_byte, |
1eff9d32 | 302 | (bio_data_dir(bio) == WRITE) ? 'w' : 'r', bio->bi_opf, |
4f024f37 | 303 | (unsigned long long)bio->bi_iter.bi_sector, bio_bytes); |
a3998799 MS |
304 | } |
305 | } | |
306 | ||
7de3ee57 | 307 | static int flakey_map(struct dm_target *ti, struct bio *bio) |
3407ef52 JB |
308 | { |
309 | struct flakey_c *fc = ti->private; | |
310 | unsigned elapsed; | |
c7cfdf59 MP |
311 | struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data)); |
312 | pb->bio_submitted = false; | |
3407ef52 | 313 | |
124c4454 DLM |
314 | /* Do not fail reset zone */ |
315 | if (bio_op(bio) == REQ_OP_ZONE_RESET) | |
316 | goto map_bio; | |
317 | ||
318 | /* We need to remap reported zones, so remember the BIO iter */ | |
319 | if (bio_op(bio) == REQ_OP_ZONE_REPORT) | |
320 | goto map_bio; | |
321 | ||
3407ef52 JB |
322 | /* Are we alive ? */ |
323 | elapsed = (jiffies - fc->start_time) / HZ; | |
b26f5e3d | 324 | if (elapsed % (fc->up_interval + fc->down_interval) >= fc->up_interval) { |
a3998799 MS |
325 | /* |
326 | * Flag this bio as submitted while down. | |
327 | */ | |
c7cfdf59 | 328 | pb->bio_submitted = true; |
a3998799 MS |
329 | |
330 | /* | |
ef548c55 | 331 | * Error reads if neither corrupt_bio_byte or drop_writes or error_writes are set. |
299f6230 | 332 | * Otherwise, flakey_end_io() will decide if the reads should be modified. |
a3998799 | 333 | */ |
99f3c90d | 334 | if (bio_data_dir(bio) == READ) { |
ef548c55 MS |
335 | if (!fc->corrupt_bio_byte && !test_bit(DROP_WRITES, &fc->flags) && |
336 | !test_bit(ERROR_WRITES, &fc->flags)) | |
846785e6 | 337 | return DM_MAPIO_KILL; |
299f6230 | 338 | goto map_bio; |
99f3c90d | 339 | } |
b26f5e3d MS |
340 | |
341 | /* | |
ef548c55 | 342 | * Drop or error writes? |
b26f5e3d MS |
343 | */ |
344 | if (test_bit(DROP_WRITES, &fc->flags)) { | |
4246a0b6 | 345 | bio_endio(bio); |
a3998799 MS |
346 | return DM_MAPIO_SUBMITTED; |
347 | } | |
ef548c55 MS |
348 | else if (test_bit(ERROR_WRITES, &fc->flags)) { |
349 | bio_io_error(bio); | |
350 | return DM_MAPIO_SUBMITTED; | |
351 | } | |
a3998799 MS |
352 | |
353 | /* | |
354 | * Corrupt matching writes. | |
355 | */ | |
356 | if (fc->corrupt_bio_byte && (fc->corrupt_bio_rw == WRITE)) { | |
357 | if (all_corrupt_bio_flags_match(bio, fc)) | |
358 | corrupt_bio_data(bio, fc); | |
b26f5e3d MS |
359 | goto map_bio; |
360 | } | |
361 | ||
362 | /* | |
a3998799 | 363 | * By default, error all I/O. |
b26f5e3d | 364 | */ |
846785e6 | 365 | return DM_MAPIO_KILL; |
b26f5e3d | 366 | } |
3407ef52 | 367 | |
b26f5e3d | 368 | map_bio: |
3407ef52 JB |
369 | flakey_map_bio(ti, bio); |
370 | ||
371 | return DM_MAPIO_REMAPPED; | |
372 | } | |
373 | ||
4e4cbee9 | 374 | static int flakey_end_io(struct dm_target *ti, struct bio *bio, |
124c4454 | 375 | blk_status_t *error) |
a3998799 MS |
376 | { |
377 | struct flakey_c *fc = ti->private; | |
c7cfdf59 | 378 | struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data)); |
a3998799 | 379 | |
124c4454 DLM |
380 | if (bio_op(bio) == REQ_OP_ZONE_RESET) |
381 | return DM_ENDIO_DONE; | |
382 | ||
383 | if (bio_op(bio) == REQ_OP_ZONE_REPORT) { | |
384 | dm_remap_zone_report(ti, bio, fc->start); | |
385 | return DM_ENDIO_DONE; | |
386 | } | |
387 | ||
1be56909 | 388 | if (!*error && pb->bio_submitted && (bio_data_dir(bio) == READ)) { |
299f6230 MS |
389 | if (fc->corrupt_bio_byte && (fc->corrupt_bio_rw == READ) && |
390 | all_corrupt_bio_flags_match(bio, fc)) { | |
391 | /* | |
392 | * Corrupt successful matching READs while in down state. | |
393 | */ | |
99f3c90d | 394 | corrupt_bio_data(bio, fc); |
299f6230 | 395 | |
ef548c55 MS |
396 | } else if (!test_bit(DROP_WRITES, &fc->flags) && |
397 | !test_bit(ERROR_WRITES, &fc->flags)) { | |
299f6230 MS |
398 | /* |
399 | * Error read during the down_interval if drop_writes | |
ef548c55 | 400 | * and error_writes were not configured. |
299f6230 | 401 | */ |
4e4cbee9 | 402 | *error = BLK_STS_IOERR; |
299f6230 | 403 | } |
99f3c90d | 404 | } |
a3998799 | 405 | |
1be56909 | 406 | return DM_ENDIO_DONE; |
a3998799 MS |
407 | } |
408 | ||
fd7c092e MP |
409 | static void flakey_status(struct dm_target *ti, status_type_t type, |
410 | unsigned status_flags, char *result, unsigned maxlen) | |
3407ef52 | 411 | { |
b26f5e3d | 412 | unsigned sz = 0; |
3407ef52 | 413 | struct flakey_c *fc = ti->private; |
ef548c55 | 414 | unsigned drop_writes, error_writes; |
3407ef52 JB |
415 | |
416 | switch (type) { | |
417 | case STATUSTYPE_INFO: | |
418 | result[0] = '\0'; | |
419 | break; | |
420 | ||
421 | case STATUSTYPE_TABLE: | |
b26f5e3d MS |
422 | DMEMIT("%s %llu %u %u ", fc->dev->name, |
423 | (unsigned long long)fc->start, fc->up_interval, | |
424 | fc->down_interval); | |
425 | ||
426 | drop_writes = test_bit(DROP_WRITES, &fc->flags); | |
ef548c55 MS |
427 | error_writes = test_bit(ERROR_WRITES, &fc->flags); |
428 | DMEMIT("%u ", drop_writes + error_writes + (fc->corrupt_bio_byte > 0) * 5); | |
a3998799 | 429 | |
b26f5e3d MS |
430 | if (drop_writes) |
431 | DMEMIT("drop_writes "); | |
ef548c55 MS |
432 | else if (error_writes) |
433 | DMEMIT("error_writes "); | |
a3998799 MS |
434 | |
435 | if (fc->corrupt_bio_byte) | |
436 | DMEMIT("corrupt_bio_byte %u %c %u %u ", | |
437 | fc->corrupt_bio_byte, | |
438 | (fc->corrupt_bio_rw == WRITE) ? 'w' : 'r', | |
439 | fc->corrupt_bio_value, fc->corrupt_bio_flags); | |
440 | ||
3407ef52 JB |
441 | break; |
442 | } | |
3407ef52 JB |
443 | } |
444 | ||
e56f81e0 CH |
445 | static int flakey_prepare_ioctl(struct dm_target *ti, |
446 | struct block_device **bdev, fmode_t *mode) | |
3407ef52 JB |
447 | { |
448 | struct flakey_c *fc = ti->private; | |
e56f81e0 CH |
449 | |
450 | *bdev = fc->dev->bdev; | |
3407ef52 | 451 | |
ec8013be PB |
452 | /* |
453 | * Only pass ioctls through if the device sizes match exactly. | |
454 | */ | |
455 | if (fc->start || | |
e56f81e0 CH |
456 | ti->len != i_size_read((*bdev)->bd_inode) >> SECTOR_SHIFT) |
457 | return 1; | |
458 | return 0; | |
3407ef52 JB |
459 | } |
460 | ||
3407ef52 JB |
461 | static int flakey_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data) |
462 | { | |
463 | struct flakey_c *fc = ti->private; | |
464 | ||
465 | return fn(ti, fc->dev, fc->start, ti->len, data); | |
466 | } | |
467 | ||
468 | static struct target_type flakey_target = { | |
469 | .name = "flakey", | |
124c4454 DLM |
470 | .version = {1, 5, 0}, |
471 | .features = DM_TARGET_ZONED_HM, | |
3407ef52 JB |
472 | .module = THIS_MODULE, |
473 | .ctr = flakey_ctr, | |
474 | .dtr = flakey_dtr, | |
475 | .map = flakey_map, | |
a3998799 | 476 | .end_io = flakey_end_io, |
3407ef52 | 477 | .status = flakey_status, |
e56f81e0 | 478 | .prepare_ioctl = flakey_prepare_ioctl, |
3407ef52 JB |
479 | .iterate_devices = flakey_iterate_devices, |
480 | }; | |
481 | ||
482 | static int __init dm_flakey_init(void) | |
483 | { | |
484 | int r = dm_register_target(&flakey_target); | |
485 | ||
486 | if (r < 0) | |
487 | DMERR("register failed %d", r); | |
488 | ||
489 | return r; | |
490 | } | |
491 | ||
492 | static void __exit dm_flakey_exit(void) | |
493 | { | |
494 | dm_unregister_target(&flakey_target); | |
495 | } | |
496 | ||
497 | /* Module hooks */ | |
498 | module_init(dm_flakey_init); | |
499 | module_exit(dm_flakey_exit); | |
500 | ||
501 | MODULE_DESCRIPTION(DM_NAME " flakey target"); | |
502 | MODULE_AUTHOR("Joe Thornber <[email protected]>"); | |
503 | MODULE_LICENSE("GPL"); |