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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 char dummy;
164
165 as.argc = argc;
166 as.argv = argv;
167
168 if (argc < 4) {
169 ti->error = "Invalid argument count";
170 return -EINVAL;
171 }
172
173 fc = kzalloc(sizeof(*fc), GFP_KERNEL);
174 if (!fc) {
175 ti->error = "Cannot allocate linear context";
176 return -ENOMEM;
177 }
178 fc->start_time = jiffies;
179
180 devname = dm_shift_arg(&as);
181
182 if (sscanf(dm_shift_arg(&as), "%llu%c", &tmpll, &dummy) != 1) {
183 ti->error = "Invalid device sector";
184 goto bad;
185 }
186 fc->start = tmpll;
187
188 r = dm_read_arg(_args, &as, &fc->up_interval, &ti->error);
189 if (r)
190 goto bad;
191
192 r = dm_read_arg(_args, &as, &fc->down_interval, &ti->error);
193 if (r)
194 goto bad;
195
196 if (!(fc->up_interval + fc->down_interval)) {
197 ti->error = "Total (up + down) interval is zero";
198 goto bad;
199 }
200
201 if (fc->up_interval + fc->down_interval < fc->up_interval) {
202 ti->error = "Interval overflow";
203 goto bad;
204 }
205
206 r = parse_features(&as, fc, ti);
207 if (r)
208 goto bad;
209
210 if (dm_get_device(ti, devname, dm_table_get_mode(ti->table), &fc->dev)) {
211 ti->error = "Device lookup failed";
212 goto bad;
213 }
214
215 ti->num_flush_requests = 1;
216 ti->num_discard_requests = 1;
217 ti->private = fc;
218 return 0;
219
220bad:
221 kfree(fc);
222 return -EINVAL;
223}
224
225static void flakey_dtr(struct dm_target *ti)
226{
227 struct flakey_c *fc = ti->private;
228
229 dm_put_device(ti, fc->dev);
230 kfree(fc);
231}
232
233static sector_t flakey_map_sector(struct dm_target *ti, sector_t bi_sector)
234{
235 struct flakey_c *fc = ti->private;
236
237 return fc->start + dm_target_offset(ti, bi_sector);
238}
239
240static void flakey_map_bio(struct dm_target *ti, struct bio *bio)
241{
242 struct flakey_c *fc = ti->private;
243
244 bio->bi_bdev = fc->dev->bdev;
245 if (bio_sectors(bio))
246 bio->bi_sector = flakey_map_sector(ti, bio->bi_sector);
247}
248
249static void corrupt_bio_data(struct bio *bio, struct flakey_c *fc)
250{
251 unsigned bio_bytes = bio_cur_bytes(bio);
252 char *data = bio_data(bio);
253
254 /*
255 * Overwrite the Nth byte of the data returned.
256 */
257 if (data && bio_bytes >= fc->corrupt_bio_byte) {
258 data[fc->corrupt_bio_byte - 1] = fc->corrupt_bio_value;
259
260 DMDEBUG("Corrupting data bio=%p by writing %u to byte %u "
261 "(rw=%c bi_rw=%lu bi_sector=%llu cur_bytes=%u)\n",
262 bio, fc->corrupt_bio_value, fc->corrupt_bio_byte,
263 (bio_data_dir(bio) == WRITE) ? 'w' : 'r',
264 bio->bi_rw, (unsigned long long)bio->bi_sector, bio_bytes);
265 }
266}
267
268static int flakey_map(struct dm_target *ti, struct bio *bio,
269 union map_info *map_context)
270{
271 struct flakey_c *fc = ti->private;
272 unsigned elapsed;
273
274 /* Are we alive ? */
275 elapsed = (jiffies - fc->start_time) / HZ;
276 if (elapsed % (fc->up_interval + fc->down_interval) >= fc->up_interval) {
277 /*
278 * Flag this bio as submitted while down.
279 */
280 map_context->ll = 1;
281
282 /*
283 * Map reads as normal.
284 */
285 if (bio_data_dir(bio) == READ)
286 goto map_bio;
287
288 /*
289 * Drop writes?
290 */
291 if (test_bit(DROP_WRITES, &fc->flags)) {
292 bio_endio(bio, 0);
293 return DM_MAPIO_SUBMITTED;
294 }
295
296 /*
297 * Corrupt matching writes.
298 */
299 if (fc->corrupt_bio_byte && (fc->corrupt_bio_rw == WRITE)) {
300 if (all_corrupt_bio_flags_match(bio, fc))
301 corrupt_bio_data(bio, fc);
302 goto map_bio;
303 }
304
305 /*
306 * By default, error all I/O.
307 */
308 return -EIO;
309 }
310
311map_bio:
312 flakey_map_bio(ti, bio);
313
314 return DM_MAPIO_REMAPPED;
315}
316
317static int flakey_end_io(struct dm_target *ti, struct bio *bio,
318 int error, union map_info *map_context)
319{
320 struct flakey_c *fc = ti->private;
321 unsigned bio_submitted_while_down = map_context->ll;
322
323 /*
324 * Corrupt successful READs while in down state.
325 * If flags were specified, only corrupt those that match.
326 */
327 if (fc->corrupt_bio_byte && !error && bio_submitted_while_down &&
328 (bio_data_dir(bio) == READ) && (fc->corrupt_bio_rw == READ) &&
329 all_corrupt_bio_flags_match(bio, fc))
330 corrupt_bio_data(bio, fc);
331
332 return error;
333}
334
335static int flakey_status(struct dm_target *ti, status_type_t type,
336 char *result, unsigned int maxlen)
337{
338 unsigned sz = 0;
339 struct flakey_c *fc = ti->private;
340 unsigned drop_writes;
341
342 switch (type) {
343 case STATUSTYPE_INFO:
344 result[0] = '\0';
345 break;
346
347 case STATUSTYPE_TABLE:
348 DMEMIT("%s %llu %u %u ", fc->dev->name,
349 (unsigned long long)fc->start, fc->up_interval,
350 fc->down_interval);
351
352 drop_writes = test_bit(DROP_WRITES, &fc->flags);
353 DMEMIT("%u ", drop_writes + (fc->corrupt_bio_byte > 0) * 5);
354
355 if (drop_writes)
356 DMEMIT("drop_writes ");
357
358 if (fc->corrupt_bio_byte)
359 DMEMIT("corrupt_bio_byte %u %c %u %u ",
360 fc->corrupt_bio_byte,
361 (fc->corrupt_bio_rw == WRITE) ? 'w' : 'r',
362 fc->corrupt_bio_value, fc->corrupt_bio_flags);
363
364 break;
365 }
366 return 0;
367}
368
369static int flakey_ioctl(struct dm_target *ti, unsigned int cmd, unsigned long arg)
370{
371 struct flakey_c *fc = ti->private;
372 struct dm_dev *dev = fc->dev;
373 int r = 0;
374
375 /*
376 * Only pass ioctls through if the device sizes match exactly.
377 */
378 if (fc->start ||
379 ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT)
380 r = scsi_verify_blk_ioctl(NULL, cmd);
381
382 return r ? : __blkdev_driver_ioctl(dev->bdev, dev->mode, cmd, arg);
383}
384
385static int flakey_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
386 struct bio_vec *biovec, int max_size)
387{
388 struct flakey_c *fc = ti->private;
389 struct request_queue *q = bdev_get_queue(fc->dev->bdev);
390
391 if (!q->merge_bvec_fn)
392 return max_size;
393
394 bvm->bi_bdev = fc->dev->bdev;
395 bvm->bi_sector = flakey_map_sector(ti, bvm->bi_sector);
396
397 return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
398}
399
400static int flakey_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
401{
402 struct flakey_c *fc = ti->private;
403
404 return fn(ti, fc->dev, fc->start, ti->len, data);
405}
406
407static struct target_type flakey_target = {
408 .name = "flakey",
409 .version = {1, 2, 0},
410 .module = THIS_MODULE,
411 .ctr = flakey_ctr,
412 .dtr = flakey_dtr,
413 .map = flakey_map,
414 .end_io = flakey_end_io,
415 .status = flakey_status,
416 .ioctl = flakey_ioctl,
417 .merge = flakey_merge,
418 .iterate_devices = flakey_iterate_devices,
419};
420
421static int __init dm_flakey_init(void)
422{
423 int r = dm_register_target(&flakey_target);
424
425 if (r < 0)
426 DMERR("register failed %d", r);
427
428 return r;
429}
430
431static void __exit dm_flakey_exit(void)
432{
433 dm_unregister_target(&flakey_target);
434}
435
436/* Module hooks */
437module_init(dm_flakey_init);
438module_exit(dm_flakey_exit);
439
440MODULE_DESCRIPTION(DM_NAME " flakey target");
441MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
442MODULE_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 unsigned 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 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
156 ti->error = "Unrecognised flakey feature requested";
157 return -EINVAL;
158 }
159
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;
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;
167 }
168
169 return 0;
170}
171
172/*
173 * Construct a flakey mapping:
174 * <dev_path> <offset> <up interval> <down interval> [<#feature args> [<arg>]*]
175 *
176 * Feature args:
177 * [drop_writes]
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.
183 */
184static int flakey_ctr(struct dm_target *ti, unsigned int argc, char **argv)
185{
186 static const struct dm_arg _args[] = {
187 {0, UINT_MAX, "Invalid up interval"},
188 {0, UINT_MAX, "Invalid down interval"},
189 };
190
191 int r;
192 struct flakey_c *fc;
193 unsigned long long tmpll;
194 struct dm_arg_set as;
195 const char *devname;
196 char dummy;
197
198 as.argc = argc;
199 as.argv = argv;
200
201 if (argc < 4) {
202 ti->error = "Invalid argument count";
203 return -EINVAL;
204 }
205
206 fc = kzalloc(sizeof(*fc), GFP_KERNEL);
207 if (!fc) {
208 ti->error = "Cannot allocate context";
209 return -ENOMEM;
210 }
211 fc->start_time = jiffies;
212
213 devname = dm_shift_arg(&as);
214
215 r = -EINVAL;
216 if (sscanf(dm_shift_arg(&as), "%llu%c", &tmpll, &dummy) != 1) {
217 ti->error = "Invalid device sector";
218 goto bad;
219 }
220 fc->start = tmpll;
221
222 r = dm_read_arg(_args, &as, &fc->up_interval, &ti->error);
223 if (r)
224 goto bad;
225
226 r = dm_read_arg(_args, &as, &fc->down_interval, &ti->error);
227 if (r)
228 goto bad;
229
230 if (!(fc->up_interval + fc->down_interval)) {
231 ti->error = "Total (up + down) interval is zero";
232 r = -EINVAL;
233 goto bad;
234 }
235
236 if (fc->up_interval + fc->down_interval < fc->up_interval) {
237 ti->error = "Interval overflow";
238 r = -EINVAL;
239 goto bad;
240 }
241
242 r = parse_features(&as, fc, ti);
243 if (r)
244 goto bad;
245
246 r = dm_get_device(ti, devname, dm_table_get_mode(ti->table), &fc->dev);
247 if (r) {
248 ti->error = "Device lookup failed";
249 goto bad;
250 }
251
252 ti->num_flush_bios = 1;
253 ti->num_discard_bios = 1;
254 ti->per_io_data_size = sizeof(struct per_bio_data);
255 ti->private = fc;
256 return 0;
257
258bad:
259 kfree(fc);
260 return r;
261}
262
263static 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
271static sector_t flakey_map_sector(struct dm_target *ti, sector_t bi_sector)
272{
273 struct flakey_c *fc = ti->private;
274
275 return fc->start + dm_target_offset(ti, bi_sector);
276}
277
278static void flakey_map_bio(struct dm_target *ti, struct bio *bio)
279{
280 struct flakey_c *fc = ti->private;
281
282 bio_set_dev(bio, fc->dev->bdev);
283 if (bio_sectors(bio) || bio_op(bio) == REQ_OP_ZONE_RESET)
284 bio->bi_iter.bi_sector =
285 flakey_map_sector(ti, bio->bi_iter.bi_sector);
286}
287
288static 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 "
300 "(rw=%c bi_opf=%u bi_sector=%llu cur_bytes=%u)\n",
301 bio, fc->corrupt_bio_value, fc->corrupt_bio_byte,
302 (bio_data_dir(bio) == WRITE) ? 'w' : 'r', bio->bi_opf,
303 (unsigned long long)bio->bi_iter.bi_sector, bio_bytes);
304 }
305}
306
307static int flakey_map(struct dm_target *ti, struct bio *bio)
308{
309 struct flakey_c *fc = ti->private;
310 unsigned elapsed;
311 struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data));
312 pb->bio_submitted = false;
313
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
322 /* Are we alive ? */
323 elapsed = (jiffies - fc->start_time) / HZ;
324 if (elapsed % (fc->up_interval + fc->down_interval) >= fc->up_interval) {
325 /*
326 * Flag this bio as submitted while down.
327 */
328 pb->bio_submitted = true;
329
330 /*
331 * Error reads if neither corrupt_bio_byte or drop_writes or error_writes are set.
332 * Otherwise, flakey_end_io() will decide if the reads should be modified.
333 */
334 if (bio_data_dir(bio) == READ) {
335 if (!fc->corrupt_bio_byte && !test_bit(DROP_WRITES, &fc->flags) &&
336 !test_bit(ERROR_WRITES, &fc->flags))
337 return DM_MAPIO_KILL;
338 goto map_bio;
339 }
340
341 /*
342 * Drop or error writes?
343 */
344 if (test_bit(DROP_WRITES, &fc->flags)) {
345 bio_endio(bio);
346 return DM_MAPIO_SUBMITTED;
347 }
348 else if (test_bit(ERROR_WRITES, &fc->flags)) {
349 bio_io_error(bio);
350 return DM_MAPIO_SUBMITTED;
351 }
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);
359 goto map_bio;
360 }
361
362 /*
363 * By default, error all I/O.
364 */
365 return DM_MAPIO_KILL;
366 }
367
368map_bio:
369 flakey_map_bio(ti, bio);
370
371 return DM_MAPIO_REMAPPED;
372}
373
374static int flakey_end_io(struct dm_target *ti, struct bio *bio,
375 blk_status_t *error)
376{
377 struct flakey_c *fc = ti->private;
378 struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data));
379
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
388 if (!*error && pb->bio_submitted && (bio_data_dir(bio) == READ)) {
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 */
394 corrupt_bio_data(bio, fc);
395
396 } else if (!test_bit(DROP_WRITES, &fc->flags) &&
397 !test_bit(ERROR_WRITES, &fc->flags)) {
398 /*
399 * Error read during the down_interval if drop_writes
400 * and error_writes were not configured.
401 */
402 *error = BLK_STS_IOERR;
403 }
404 }
405
406 return DM_ENDIO_DONE;
407}
408
409static void flakey_status(struct dm_target *ti, status_type_t type,
410 unsigned status_flags, char *result, unsigned maxlen)
411{
412 unsigned sz = 0;
413 struct flakey_c *fc = ti->private;
414 unsigned drop_writes, error_writes;
415
416 switch (type) {
417 case STATUSTYPE_INFO:
418 result[0] = '\0';
419 break;
420
421 case STATUSTYPE_TABLE:
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);
427 error_writes = test_bit(ERROR_WRITES, &fc->flags);
428 DMEMIT("%u ", drop_writes + error_writes + (fc->corrupt_bio_byte > 0) * 5);
429
430 if (drop_writes)
431 DMEMIT("drop_writes ");
432 else if (error_writes)
433 DMEMIT("error_writes ");
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
441 break;
442 }
443}
444
445static int flakey_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
446{
447 struct flakey_c *fc = ti->private;
448
449 *bdev = fc->dev->bdev;
450
451 /*
452 * Only pass ioctls through if the device sizes match exactly.
453 */
454 if (fc->start ||
455 ti->len != i_size_read((*bdev)->bd_inode) >> SECTOR_SHIFT)
456 return 1;
457 return 0;
458}
459
460static int flakey_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
461{
462 struct flakey_c *fc = ti->private;
463
464 return fn(ti, fc->dev, fc->start, ti->len, data);
465}
466
467static struct target_type flakey_target = {
468 .name = "flakey",
469 .version = {1, 5, 0},
470 .features = DM_TARGET_ZONED_HM,
471 .module = THIS_MODULE,
472 .ctr = flakey_ctr,
473 .dtr = flakey_dtr,
474 .map = flakey_map,
475 .end_io = flakey_end_io,
476 .status = flakey_status,
477 .prepare_ioctl = flakey_prepare_ioctl,
478 .iterate_devices = flakey_iterate_devices,
479};
480
481static int __init dm_flakey_init(void)
482{
483 int r = dm_register_target(&flakey_target);
484
485 if (r < 0)
486 DMERR("register failed %d", r);
487
488 return r;
489}
490
491static void __exit dm_flakey_exit(void)
492{
493 dm_unregister_target(&flakey_target);
494}
495
496/* Module hooks */
497module_init(dm_flakey_init);
498module_exit(dm_flakey_exit);
499
500MODULE_DESCRIPTION(DM_NAME " flakey target");
501MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
502MODULE_LICENSE("GPL");