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1/*
2 * Copyright (C) 2003 Sistina Software (UK) Limited.
3 * Copyright (C) 2004, 2010-2011 Red Hat, Inc. All rights reserved.
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
18#define all_corrupt_bio_flags_match(bio, fc) \
19 (((bio)->bi_rw & (fc)->corrupt_bio_flags) == (fc)->corrupt_bio_flags)
20
21/*
22 * Flakey: Used for testing only, simulates intermittent,
23 * catastrophic device failure.
24 */
25struct flakey_c {
26 struct dm_dev *dev;
27 unsigned long start_time;
28 sector_t start;
29 unsigned up_interval;
30 unsigned down_interval;
31 unsigned long flags;
32 unsigned corrupt_bio_byte;
33 unsigned corrupt_bio_rw;
34 unsigned corrupt_bio_value;
35 unsigned corrupt_bio_flags;
36};
37
38enum feature_flag_bits {
39 DROP_WRITES
40};
41
42static int parse_features(struct dm_arg_set *as, struct flakey_c *fc,
43 struct dm_target *ti)
44{
45 int r;
46 unsigned argc;
47 const char *arg_name;
48
49 static struct dm_arg _args[] = {
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"},
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)
62 return r;
63
64 while (argc) {
65 arg_name = dm_shift_arg(as);
66 argc--;
67
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
80 /*
81 * corrupt_bio_byte <Nth_byte> <direction> <value> <bio_flags>
82 */
83 if (!strcasecmp(arg_name, "corrupt_bio_byte")) {
84 if (!argc) {
85 ti->error = "Feature corrupt_bio_byte requires parameters";
86 return -EINVAL;
87 }
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
127 ti->error = "Unrecognised flakey feature requested";
128 return -EINVAL;
129 }
130
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;
137}
138
139/*
140 * Construct a flakey mapping:
141 * <dev_path> <offset> <up interval> <down interval> [<#feature args> [<arg>]*]
142 *
143 * Feature args:
144 * [drop_writes]
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.
150 */
151static int flakey_ctr(struct dm_target *ti, unsigned int argc, char **argv)
152{
153 static struct dm_arg _args[] = {
154 {0, UINT_MAX, "Invalid up interval"},
155 {0, UINT_MAX, "Invalid down interval"},
156 };
157
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";
169 return -EINVAL;
170 }
171
172 fc = kzalloc(sizeof(*fc), GFP_KERNEL);
173 if (!fc) {
174 ti->error = "Cannot allocate linear context";
175 return -ENOMEM;
176 }
177 fc->start_time = jiffies;
178
179 devname = dm_shift_arg(&as);
180
181 if (sscanf(dm_shift_arg(&as), "%llu", &tmpll) != 1) {
182 ti->error = "Invalid device sector";
183 goto bad;
184 }
185 fc->start = tmpll;
186
187 r = dm_read_arg(_args, &as, &fc->up_interval, &ti->error);
188 if (r)
189 goto bad;
190
191 r = dm_read_arg(_args, &as, &fc->down_interval, &ti->error);
192 if (r)
193 goto bad;
194
195 if (!(fc->up_interval + fc->down_interval)) {
196 ti->error = "Total (up + down) interval is zero";
197 goto bad;
198 }
199
200 if (fc->up_interval + fc->down_interval < fc->up_interval) {
201 ti->error = "Interval overflow";
202 goto bad;
203 }
204
205 r = parse_features(&as, fc, ti);
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";
211 goto bad;
212 }
213
214 ti->num_flush_requests = 1;
215 ti->num_discard_requests = 1;
216 ti->private = fc;
217 return 0;
218
219bad:
220 kfree(fc);
221 return -EINVAL;
222}
223
224static 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
232static sector_t flakey_map_sector(struct dm_target *ti, sector_t bi_sector)
233{
234 struct flakey_c *fc = ti->private;
235
236 return fc->start + dm_target_offset(ti, bi_sector);
237}
238
239static 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
248static 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
267static 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;
275 if (elapsed % (fc->up_interval + fc->down_interval) >= fc->up_interval) {
276 /*
277 * Flag this bio as submitted while down.
278 */
279 map_context->ll = 1;
280
281 /*
282 * Map reads as normal.
283 */
284 if (bio_data_dir(bio) == READ)
285 goto map_bio;
286
287 /*
288 * Drop writes?
289 */
290 if (test_bit(DROP_WRITES, &fc->flags)) {
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);
301 goto map_bio;
302 }
303
304 /*
305 * By default, error all I/O.
306 */
307 return -EIO;
308 }
309
310map_bio:
311 flakey_map_bio(ti, bio);
312
313 return DM_MAPIO_REMAPPED;
314}
315
316static 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 */
326 if (!error && bio_submitted_while_down &&
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
334static int flakey_status(struct dm_target *ti, status_type_t type,
335 char *result, unsigned int maxlen)
336{
337 unsigned sz = 0;
338 struct flakey_c *fc = ti->private;
339 unsigned drop_writes;
340
341 switch (type) {
342 case STATUSTYPE_INFO:
343 result[0] = '\0';
344 break;
345
346 case STATUSTYPE_TABLE:
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);
352 DMEMIT("%u ", drop_writes + (fc->corrupt_bio_byte > 0) * 5);
353
354 if (drop_writes)
355 DMEMIT("drop_writes ");
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
363 break;
364 }
365 return 0;
366}
367
368static int flakey_ioctl(struct dm_target *ti, unsigned int cmd, unsigned long arg)
369{
370 struct flakey_c *fc = ti->private;
371
372 return __blkdev_driver_ioctl(fc->dev->bdev, fc->dev->mode, cmd, arg);
373}
374
375static int flakey_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
376 struct bio_vec *biovec, int max_size)
377{
378 struct flakey_c *fc = ti->private;
379 struct request_queue *q = bdev_get_queue(fc->dev->bdev);
380
381 if (!q->merge_bvec_fn)
382 return max_size;
383
384 bvm->bi_bdev = fc->dev->bdev;
385 bvm->bi_sector = flakey_map_sector(ti, bvm->bi_sector);
386
387 return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
388}
389
390static int flakey_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
391{
392 struct flakey_c *fc = ti->private;
393
394 return fn(ti, fc->dev, fc->start, ti->len, data);
395}
396
397static struct target_type flakey_target = {
398 .name = "flakey",
399 .version = {1, 2, 0},
400 .module = THIS_MODULE,
401 .ctr = flakey_ctr,
402 .dtr = flakey_dtr,
403 .map = flakey_map,
404 .end_io = flakey_end_io,
405 .status = flakey_status,
406 .ioctl = flakey_ioctl,
407 .merge = flakey_merge,
408 .iterate_devices = flakey_iterate_devices,
409};
410
411static int __init dm_flakey_init(void)
412{
413 int r = dm_register_target(&flakey_target);
414
415 if (r < 0)
416 DMERR("register failed %d", r);
417
418 return r;
419}
420
421static void __exit dm_flakey_exit(void)
422{
423 dm_unregister_target(&flakey_target);
424}
425
426/* Module hooks */
427module_init(dm_flakey_init);
428module_exit(dm_flakey_exit);
429
430MODULE_DESCRIPTION(DM_NAME " flakey target");
431MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
432MODULE_LICENSE("GPL");
1/*
2 * Copyright (C) 2003 Sistina Software (UK) Limited.
3 * Copyright (C) 2004, 2010-2011 Red Hat, Inc. All rights reserved.
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
18#define all_corrupt_bio_flags_match(bio, fc) \
19 (((bio)->bi_opf & (fc)->corrupt_bio_flags) == (fc)->corrupt_bio_flags)
20
21/*
22 * Flakey: Used for testing only, simulates intermittent,
23 * catastrophic device failure.
24 */
25struct flakey_c {
26 struct dm_dev *dev;
27 unsigned long start_time;
28 sector_t start;
29 unsigned up_interval;
30 unsigned down_interval;
31 unsigned long flags;
32 unsigned corrupt_bio_byte;
33 unsigned corrupt_bio_rw;
34 unsigned corrupt_bio_value;
35 blk_opf_t corrupt_bio_flags;
36};
37
38enum feature_flag_bits {
39 DROP_WRITES,
40 ERROR_WRITES
41};
42
43struct per_bio_data {
44 bool bio_submitted;
45};
46
47static int parse_features(struct dm_arg_set *as, struct flakey_c *fc,
48 struct dm_target *ti)
49{
50 int r;
51 unsigned argc;
52 const char *arg_name;
53
54 static const struct dm_arg _args[] = {
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"},
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)
67 return r;
68
69 while (argc) {
70 arg_name = dm_shift_arg(as);
71 argc--;
72
73 if (!arg_name) {
74 ti->error = "Insufficient feature arguments";
75 return -EINVAL;
76 }
77
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;
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;
104 }
105
106 continue;
107 }
108
109 /*
110 * corrupt_bio_byte <Nth_byte> <direction> <value> <bio_flags>
111 */
112 if (!strcasecmp(arg_name, "corrupt_bio_byte")) {
113 if (!argc) {
114 ti->error = "Feature corrupt_bio_byte requires parameters";
115 return -EINVAL;
116 }
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 BUILD_BUG_ON(sizeof(fc->corrupt_bio_flags) !=
149 sizeof(unsigned int));
150 r = dm_read_arg(_args + 3, as,
151 (__force unsigned *)&fc->corrupt_bio_flags,
152 &ti->error);
153 if (r)
154 return r;
155 argc--;
156
157 continue;
158 }
159
160 ti->error = "Unrecognised flakey feature requested";
161 return -EINVAL;
162 }
163
164 if (test_bit(DROP_WRITES, &fc->flags) && (fc->corrupt_bio_rw == WRITE)) {
165 ti->error = "drop_writes is incompatible with corrupt_bio_byte with the WRITE flag set";
166 return -EINVAL;
167
168 } else if (test_bit(ERROR_WRITES, &fc->flags) && (fc->corrupt_bio_rw == WRITE)) {
169 ti->error = "error_writes is incompatible with corrupt_bio_byte with the WRITE flag set";
170 return -EINVAL;
171 }
172
173 return 0;
174}
175
176/*
177 * Construct a flakey mapping:
178 * <dev_path> <offset> <up interval> <down interval> [<#feature args> [<arg>]*]
179 *
180 * Feature args:
181 * [drop_writes]
182 * [corrupt_bio_byte <Nth_byte> <direction> <value> <bio_flags>]
183 *
184 * Nth_byte starts from 1 for the first byte.
185 * Direction is r for READ or w for WRITE.
186 * bio_flags is ignored if 0.
187 */
188static int flakey_ctr(struct dm_target *ti, unsigned int argc, char **argv)
189{
190 static const struct dm_arg _args[] = {
191 {0, UINT_MAX, "Invalid up interval"},
192 {0, UINT_MAX, "Invalid down interval"},
193 };
194
195 int r;
196 struct flakey_c *fc;
197 unsigned long long tmpll;
198 struct dm_arg_set as;
199 const char *devname;
200 char dummy;
201
202 as.argc = argc;
203 as.argv = argv;
204
205 if (argc < 4) {
206 ti->error = "Invalid argument count";
207 return -EINVAL;
208 }
209
210 fc = kzalloc(sizeof(*fc), GFP_KERNEL);
211 if (!fc) {
212 ti->error = "Cannot allocate context";
213 return -ENOMEM;
214 }
215 fc->start_time = jiffies;
216
217 devname = dm_shift_arg(&as);
218
219 r = -EINVAL;
220 if (sscanf(dm_shift_arg(&as), "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) {
221 ti->error = "Invalid device sector";
222 goto bad;
223 }
224 fc->start = tmpll;
225
226 r = dm_read_arg(_args, &as, &fc->up_interval, &ti->error);
227 if (r)
228 goto bad;
229
230 r = dm_read_arg(_args, &as, &fc->down_interval, &ti->error);
231 if (r)
232 goto bad;
233
234 if (!(fc->up_interval + fc->down_interval)) {
235 ti->error = "Total (up + down) interval is zero";
236 r = -EINVAL;
237 goto bad;
238 }
239
240 if (fc->up_interval + fc->down_interval < fc->up_interval) {
241 ti->error = "Interval overflow";
242 r = -EINVAL;
243 goto bad;
244 }
245
246 r = parse_features(&as, fc, ti);
247 if (r)
248 goto bad;
249
250 r = dm_get_device(ti, devname, dm_table_get_mode(ti->table), &fc->dev);
251 if (r) {
252 ti->error = "Device lookup failed";
253 goto bad;
254 }
255
256 ti->num_flush_bios = 1;
257 ti->num_discard_bios = 1;
258 ti->per_io_data_size = sizeof(struct per_bio_data);
259 ti->private = fc;
260 return 0;
261
262bad:
263 kfree(fc);
264 return r;
265}
266
267static void flakey_dtr(struct dm_target *ti)
268{
269 struct flakey_c *fc = ti->private;
270
271 dm_put_device(ti, fc->dev);
272 kfree(fc);
273}
274
275static sector_t flakey_map_sector(struct dm_target *ti, sector_t bi_sector)
276{
277 struct flakey_c *fc = ti->private;
278
279 return fc->start + dm_target_offset(ti, bi_sector);
280}
281
282static void flakey_map_bio(struct dm_target *ti, struct bio *bio)
283{
284 struct flakey_c *fc = ti->private;
285
286 bio_set_dev(bio, fc->dev->bdev);
287 bio->bi_iter.bi_sector = flakey_map_sector(ti, bio->bi_iter.bi_sector);
288}
289
290static void corrupt_bio_data(struct bio *bio, struct flakey_c *fc)
291{
292 unsigned int corrupt_bio_byte = fc->corrupt_bio_byte - 1;
293
294 struct bvec_iter iter;
295 struct bio_vec bvec;
296
297 if (!bio_has_data(bio))
298 return;
299
300 /*
301 * Overwrite the Nth byte of the bio's data, on whichever page
302 * it falls.
303 */
304 bio_for_each_segment(bvec, bio, iter) {
305 if (bio_iter_len(bio, iter) > corrupt_bio_byte) {
306 char *segment = (page_address(bio_iter_page(bio, iter))
307 + bio_iter_offset(bio, iter));
308 segment[corrupt_bio_byte] = fc->corrupt_bio_value;
309 DMDEBUG("Corrupting data bio=%p by writing %u to byte %u "
310 "(rw=%c bi_opf=%u bi_sector=%llu size=%u)\n",
311 bio, fc->corrupt_bio_value, fc->corrupt_bio_byte,
312 (bio_data_dir(bio) == WRITE) ? 'w' : 'r', bio->bi_opf,
313 (unsigned long long)bio->bi_iter.bi_sector, bio->bi_iter.bi_size);
314 break;
315 }
316 corrupt_bio_byte -= bio_iter_len(bio, iter);
317 }
318}
319
320static int flakey_map(struct dm_target *ti, struct bio *bio)
321{
322 struct flakey_c *fc = ti->private;
323 unsigned elapsed;
324 struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data));
325 pb->bio_submitted = false;
326
327 if (op_is_zone_mgmt(bio_op(bio)))
328 goto map_bio;
329
330 /* Are we alive ? */
331 elapsed = (jiffies - fc->start_time) / HZ;
332 if (elapsed % (fc->up_interval + fc->down_interval) >= fc->up_interval) {
333 /*
334 * Flag this bio as submitted while down.
335 */
336 pb->bio_submitted = true;
337
338 /*
339 * Error reads if neither corrupt_bio_byte or drop_writes or error_writes are set.
340 * Otherwise, flakey_end_io() will decide if the reads should be modified.
341 */
342 if (bio_data_dir(bio) == READ) {
343 if (!fc->corrupt_bio_byte && !test_bit(DROP_WRITES, &fc->flags) &&
344 !test_bit(ERROR_WRITES, &fc->flags))
345 return DM_MAPIO_KILL;
346 goto map_bio;
347 }
348
349 /*
350 * Drop or error writes?
351 */
352 if (test_bit(DROP_WRITES, &fc->flags)) {
353 bio_endio(bio);
354 return DM_MAPIO_SUBMITTED;
355 }
356 else if (test_bit(ERROR_WRITES, &fc->flags)) {
357 bio_io_error(bio);
358 return DM_MAPIO_SUBMITTED;
359 }
360
361 /*
362 * Corrupt matching writes.
363 */
364 if (fc->corrupt_bio_byte && (fc->corrupt_bio_rw == WRITE)) {
365 if (all_corrupt_bio_flags_match(bio, fc))
366 corrupt_bio_data(bio, fc);
367 goto map_bio;
368 }
369
370 /*
371 * By default, error all I/O.
372 */
373 return DM_MAPIO_KILL;
374 }
375
376map_bio:
377 flakey_map_bio(ti, bio);
378
379 return DM_MAPIO_REMAPPED;
380}
381
382static int flakey_end_io(struct dm_target *ti, struct bio *bio,
383 blk_status_t *error)
384{
385 struct flakey_c *fc = ti->private;
386 struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data));
387
388 if (op_is_zone_mgmt(bio_op(bio)))
389 return DM_ENDIO_DONE;
390
391 if (!*error && pb->bio_submitted && (bio_data_dir(bio) == READ)) {
392 if (fc->corrupt_bio_byte && (fc->corrupt_bio_rw == READ) &&
393 all_corrupt_bio_flags_match(bio, fc)) {
394 /*
395 * Corrupt successful matching READs while in down state.
396 */
397 corrupt_bio_data(bio, fc);
398
399 } else if (!test_bit(DROP_WRITES, &fc->flags) &&
400 !test_bit(ERROR_WRITES, &fc->flags)) {
401 /*
402 * Error read during the down_interval if drop_writes
403 * and error_writes were not configured.
404 */
405 *error = BLK_STS_IOERR;
406 }
407 }
408
409 return DM_ENDIO_DONE;
410}
411
412static void flakey_status(struct dm_target *ti, status_type_t type,
413 unsigned status_flags, char *result, unsigned maxlen)
414{
415 unsigned sz = 0;
416 struct flakey_c *fc = ti->private;
417 unsigned drop_writes, error_writes;
418
419 switch (type) {
420 case STATUSTYPE_INFO:
421 result[0] = '\0';
422 break;
423
424 case STATUSTYPE_TABLE:
425 DMEMIT("%s %llu %u %u ", fc->dev->name,
426 (unsigned long long)fc->start, fc->up_interval,
427 fc->down_interval);
428
429 drop_writes = test_bit(DROP_WRITES, &fc->flags);
430 error_writes = test_bit(ERROR_WRITES, &fc->flags);
431 DMEMIT("%u ", drop_writes + error_writes + (fc->corrupt_bio_byte > 0) * 5);
432
433 if (drop_writes)
434 DMEMIT("drop_writes ");
435 else if (error_writes)
436 DMEMIT("error_writes ");
437
438 if (fc->corrupt_bio_byte)
439 DMEMIT("corrupt_bio_byte %u %c %u %u ",
440 fc->corrupt_bio_byte,
441 (fc->corrupt_bio_rw == WRITE) ? 'w' : 'r',
442 fc->corrupt_bio_value, fc->corrupt_bio_flags);
443
444 break;
445
446 case STATUSTYPE_IMA:
447 result[0] = '\0';
448 break;
449 }
450}
451
452static int flakey_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
453{
454 struct flakey_c *fc = ti->private;
455
456 *bdev = fc->dev->bdev;
457
458 /*
459 * Only pass ioctls through if the device sizes match exactly.
460 */
461 if (fc->start || ti->len != bdev_nr_sectors((*bdev)))
462 return 1;
463 return 0;
464}
465
466#ifdef CONFIG_BLK_DEV_ZONED
467static int flakey_report_zones(struct dm_target *ti,
468 struct dm_report_zones_args *args, unsigned int nr_zones)
469{
470 struct flakey_c *fc = ti->private;
471
472 return dm_report_zones(fc->dev->bdev, fc->start,
473 flakey_map_sector(ti, args->next_sector),
474 args, nr_zones);
475}
476#else
477#define flakey_report_zones NULL
478#endif
479
480static int flakey_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
481{
482 struct flakey_c *fc = ti->private;
483
484 return fn(ti, fc->dev, fc->start, ti->len, data);
485}
486
487static struct target_type flakey_target = {
488 .name = "flakey",
489 .version = {1, 5, 0},
490 .features = DM_TARGET_ZONED_HM | DM_TARGET_PASSES_CRYPTO,
491 .report_zones = flakey_report_zones,
492 .module = THIS_MODULE,
493 .ctr = flakey_ctr,
494 .dtr = flakey_dtr,
495 .map = flakey_map,
496 .end_io = flakey_end_io,
497 .status = flakey_status,
498 .prepare_ioctl = flakey_prepare_ioctl,
499 .iterate_devices = flakey_iterate_devices,
500};
501
502static int __init dm_flakey_init(void)
503{
504 int r = dm_register_target(&flakey_target);
505
506 if (r < 0)
507 DMERR("register failed %d", r);
508
509 return r;
510}
511
512static void __exit dm_flakey_exit(void)
513{
514 dm_unregister_target(&flakey_target);
515}
516
517/* Module hooks */
518module_init(dm_flakey_init);
519module_exit(dm_flakey_exit);
520
521MODULE_DESCRIPTION(DM_NAME " flakey target");
522MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
523MODULE_LICENSE("GPL");