13bd94003SHeinz Mauelshagen // SPDX-License-Identifier: GPL-2.0-only
23407ef52SJosef Bacik /*
33407ef52SJosef Bacik * Copyright (C) 2003 Sistina Software (UK) Limited.
4a3998799SMike Snitzer * Copyright (C) 2004, 2010-2011 Red Hat, Inc. All rights reserved.
53407ef52SJosef Bacik *
63407ef52SJosef Bacik * This file is released under the GPL.
73407ef52SJosef Bacik */
83407ef52SJosef Bacik
93407ef52SJosef Bacik #include <linux/device-mapper.h>
103407ef52SJosef Bacik
113407ef52SJosef Bacik #include <linux/module.h>
123407ef52SJosef Bacik #include <linux/init.h>
133407ef52SJosef Bacik #include <linux/blkdev.h>
143407ef52SJosef Bacik #include <linux/bio.h>
153407ef52SJosef Bacik #include <linux/slab.h>
163407ef52SJosef Bacik
173407ef52SJosef Bacik #define DM_MSG_PREFIX "flakey"
183407ef52SJosef Bacik
194c2c845bSMikulas Patocka #define PROBABILITY_BASE 1000000000
204c2c845bSMikulas Patocka
21a3998799SMike Snitzer #define all_corrupt_bio_flags_match(bio, fc) \
221eff9d32SJens Axboe (((bio)->bi_opf & (fc)->corrupt_bio_flags) == (fc)->corrupt_bio_flags)
23a3998799SMike Snitzer
243407ef52SJosef Bacik /*
253407ef52SJosef Bacik * Flakey: Used for testing only, simulates intermittent,
263407ef52SJosef Bacik * catastrophic device failure.
273407ef52SJosef Bacik */
283407ef52SJosef Bacik struct flakey_c {
293407ef52SJosef Bacik struct dm_dev *dev;
303407ef52SJosef Bacik unsigned long start_time;
313407ef52SJosef Bacik sector_t start;
3286a3238cSHeinz Mauelshagen unsigned int up_interval;
3386a3238cSHeinz Mauelshagen unsigned int down_interval;
34b26f5e3dSMike Snitzer unsigned long flags;
3586a3238cSHeinz Mauelshagen unsigned int corrupt_bio_byte;
3686a3238cSHeinz Mauelshagen unsigned int corrupt_bio_rw;
3786a3238cSHeinz Mauelshagen unsigned int corrupt_bio_value;
38eff17e51SBart Van Assche blk_opf_t corrupt_bio_flags;
394c2c845bSMikulas Patocka unsigned int random_read_corrupt;
404c2c845bSMikulas Patocka unsigned int random_write_corrupt;
413407ef52SJosef Bacik };
423407ef52SJosef Bacik
43b26f5e3dSMike Snitzer enum feature_flag_bits {
44aa7d7bc9SMikulas Patocka ERROR_READS,
45ef548c55SMike Snitzer DROP_WRITES,
46ef548c55SMike Snitzer ERROR_WRITES
47b26f5e3dSMike Snitzer };
48b26f5e3dSMike Snitzer
49c7cfdf59SMikulas Patocka struct per_bio_data {
50c7cfdf59SMikulas Patocka bool bio_submitted;
51c7cfdf59SMikulas Patocka };
52c7cfdf59SMikulas Patocka
parse_features(struct dm_arg_set * as,struct flakey_c * fc,struct dm_target * ti)53b26f5e3dSMike Snitzer static int parse_features(struct dm_arg_set *as, struct flakey_c *fc,
54b26f5e3dSMike Snitzer struct dm_target *ti)
55dfd068b0SMike Snitzer {
56dfd068b0SMike Snitzer int r;
5786a3238cSHeinz Mauelshagen unsigned int argc;
58dfd068b0SMike Snitzer const char *arg_name;
59dfd068b0SMike Snitzer
605916a22bSEric Biggers static const struct dm_arg _args[] = {
614c2c845bSMikulas Patocka {0, 11, "Invalid number of feature args"},
62a3998799SMike Snitzer {1, UINT_MAX, "Invalid corrupt bio byte"},
63a3998799SMike Snitzer {0, 255, "Invalid corrupt value to write into bio byte (0-255)"},
64a3998799SMike Snitzer {0, UINT_MAX, "Invalid corrupt bio flags mask"},
654c2c845bSMikulas Patocka {0, PROBABILITY_BASE, "Invalid random corrupt argument"},
66dfd068b0SMike Snitzer };
67dfd068b0SMike Snitzer
68dfd068b0SMike Snitzer /* No feature arguments supplied. */
69dfd068b0SMike Snitzer if (!as->argc)
70dfd068b0SMike Snitzer return 0;
71dfd068b0SMike Snitzer
72dfd068b0SMike Snitzer r = dm_read_arg_group(_args, as, &argc, &ti->error);
73dfd068b0SMike Snitzer if (r)
74a3998799SMike Snitzer return r;
75dfd068b0SMike Snitzer
76a3998799SMike Snitzer while (argc) {
77dfd068b0SMike Snitzer arg_name = dm_shift_arg(as);
78dfd068b0SMike Snitzer argc--;
79dfd068b0SMike Snitzer
807690e253SGoldwyn Rodrigues if (!arg_name) {
817690e253SGoldwyn Rodrigues ti->error = "Insufficient feature arguments";
827690e253SGoldwyn Rodrigues return -EINVAL;
837690e253SGoldwyn Rodrigues }
847690e253SGoldwyn Rodrigues
85b26f5e3dSMike Snitzer /*
86aa7d7bc9SMikulas Patocka * error_reads
87aa7d7bc9SMikulas Patocka */
88aa7d7bc9SMikulas Patocka if (!strcasecmp(arg_name, "error_reads")) {
89aa7d7bc9SMikulas Patocka if (test_and_set_bit(ERROR_READS, &fc->flags)) {
90aa7d7bc9SMikulas Patocka ti->error = "Feature error_reads duplicated";
91aa7d7bc9SMikulas Patocka return -EINVAL;
92aa7d7bc9SMikulas Patocka }
93aa7d7bc9SMikulas Patocka continue;
94aa7d7bc9SMikulas Patocka }
95aa7d7bc9SMikulas Patocka
96aa7d7bc9SMikulas Patocka /*
97b26f5e3dSMike Snitzer * drop_writes
98b26f5e3dSMike Snitzer */
99b26f5e3dSMike Snitzer if (!strcasecmp(arg_name, "drop_writes")) {
100b26f5e3dSMike Snitzer if (test_and_set_bit(DROP_WRITES, &fc->flags)) {
101b26f5e3dSMike Snitzer ti->error = "Feature drop_writes duplicated";
102b26f5e3dSMike Snitzer return -EINVAL;
103ef548c55SMike Snitzer } else if (test_bit(ERROR_WRITES, &fc->flags)) {
104ef548c55SMike Snitzer ti->error = "Feature drop_writes conflicts with feature error_writes";
105ef548c55SMike Snitzer return -EINVAL;
106ef548c55SMike Snitzer }
107ef548c55SMike Snitzer
108ef548c55SMike Snitzer continue;
109ef548c55SMike Snitzer }
110ef548c55SMike Snitzer
111ef548c55SMike Snitzer /*
112ef548c55SMike Snitzer * error_writes
113ef548c55SMike Snitzer */
114ef548c55SMike Snitzer if (!strcasecmp(arg_name, "error_writes")) {
115ef548c55SMike Snitzer if (test_and_set_bit(ERROR_WRITES, &fc->flags)) {
116ef548c55SMike Snitzer ti->error = "Feature error_writes duplicated";
117ef548c55SMike Snitzer return -EINVAL;
118ef548c55SMike Snitzer
119ef548c55SMike Snitzer } else if (test_bit(DROP_WRITES, &fc->flags)) {
120ef548c55SMike Snitzer ti->error = "Feature error_writes conflicts with feature drop_writes";
121ef548c55SMike Snitzer return -EINVAL;
122b26f5e3dSMike Snitzer }
123b26f5e3dSMike Snitzer
124b26f5e3dSMike Snitzer continue;
125b26f5e3dSMike Snitzer }
126b26f5e3dSMike Snitzer
127a3998799SMike Snitzer /*
128a3998799SMike Snitzer * corrupt_bio_byte <Nth_byte> <direction> <value> <bio_flags>
129a3998799SMike Snitzer */
130a3998799SMike Snitzer if (!strcasecmp(arg_name, "corrupt_bio_byte")) {
13168e58a29SMike Snitzer if (!argc) {
132a3998799SMike Snitzer ti->error = "Feature corrupt_bio_byte requires parameters";
13368e58a29SMike Snitzer return -EINVAL;
13468e58a29SMike Snitzer }
135a3998799SMike Snitzer
136a3998799SMike Snitzer r = dm_read_arg(_args + 1, as, &fc->corrupt_bio_byte, &ti->error);
137a3998799SMike Snitzer if (r)
138a3998799SMike Snitzer return r;
139a3998799SMike Snitzer argc--;
140a3998799SMike Snitzer
141a3998799SMike Snitzer /*
142a3998799SMike Snitzer * Direction r or w?
143a3998799SMike Snitzer */
144a3998799SMike Snitzer arg_name = dm_shift_arg(as);
14598dba02dSMikulas Patocka if (arg_name && !strcasecmp(arg_name, "w"))
146a3998799SMike Snitzer fc->corrupt_bio_rw = WRITE;
14798dba02dSMikulas Patocka else if (arg_name && !strcasecmp(arg_name, "r"))
148a3998799SMike Snitzer fc->corrupt_bio_rw = READ;
149a3998799SMike Snitzer else {
150a3998799SMike Snitzer ti->error = "Invalid corrupt bio direction (r or w)";
151a3998799SMike Snitzer return -EINVAL;
152a3998799SMike Snitzer }
153a3998799SMike Snitzer argc--;
154a3998799SMike Snitzer
155a3998799SMike Snitzer /*
156a3998799SMike Snitzer * Value of byte (0-255) to write in place of correct one.
157a3998799SMike Snitzer */
158a3998799SMike Snitzer r = dm_read_arg(_args + 2, as, &fc->corrupt_bio_value, &ti->error);
159a3998799SMike Snitzer if (r)
160a3998799SMike Snitzer return r;
161a3998799SMike Snitzer argc--;
162a3998799SMike Snitzer
163a3998799SMike Snitzer /*
164a3998799SMike Snitzer * Only corrupt bios with these flags set.
165a3998799SMike Snitzer */
166eff17e51SBart Van Assche BUILD_BUG_ON(sizeof(fc->corrupt_bio_flags) !=
167eff17e51SBart Van Assche sizeof(unsigned int));
168eff17e51SBart Van Assche r = dm_read_arg(_args + 3, as,
16986a3238cSHeinz Mauelshagen (__force unsigned int *)&fc->corrupt_bio_flags,
170eff17e51SBart Van Assche &ti->error);
171a3998799SMike Snitzer if (r)
172a3998799SMike Snitzer return r;
173a3998799SMike Snitzer argc--;
174a3998799SMike Snitzer
175a3998799SMike Snitzer continue;
176dfd068b0SMike Snitzer }
177dfd068b0SMike Snitzer
1784c2c845bSMikulas Patocka if (!strcasecmp(arg_name, "random_read_corrupt")) {
1794c2c845bSMikulas Patocka if (!argc) {
1804c2c845bSMikulas Patocka ti->error = "Feature random_read_corrupt requires a parameter";
1814c2c845bSMikulas Patocka return -EINVAL;
1824c2c845bSMikulas Patocka }
1834c2c845bSMikulas Patocka r = dm_read_arg(_args + 4, as, &fc->random_read_corrupt, &ti->error);
1844c2c845bSMikulas Patocka if (r)
1854c2c845bSMikulas Patocka return r;
1864c2c845bSMikulas Patocka argc--;
1874c2c845bSMikulas Patocka
1884c2c845bSMikulas Patocka continue;
1894c2c845bSMikulas Patocka }
1904c2c845bSMikulas Patocka
1914c2c845bSMikulas Patocka if (!strcasecmp(arg_name, "random_write_corrupt")) {
1924c2c845bSMikulas Patocka if (!argc) {
1934c2c845bSMikulas Patocka ti->error = "Feature random_write_corrupt requires a parameter";
1944c2c845bSMikulas Patocka return -EINVAL;
1954c2c845bSMikulas Patocka }
1964c2c845bSMikulas Patocka r = dm_read_arg(_args + 4, as, &fc->random_write_corrupt, &ti->error);
1974c2c845bSMikulas Patocka if (r)
1984c2c845bSMikulas Patocka return r;
1994c2c845bSMikulas Patocka argc--;
2004c2c845bSMikulas Patocka
2014c2c845bSMikulas Patocka continue;
2024c2c845bSMikulas Patocka }
2034c2c845bSMikulas Patocka
204a3998799SMike Snitzer ti->error = "Unrecognised flakey feature requested";
205a3998799SMike Snitzer return -EINVAL;
206a3998799SMike Snitzer }
207a3998799SMike Snitzer
208a3998799SMike Snitzer if (test_bit(DROP_WRITES, &fc->flags) && (fc->corrupt_bio_rw == WRITE)) {
209a3998799SMike Snitzer ti->error = "drop_writes is incompatible with corrupt_bio_byte with the WRITE flag set";
210a3998799SMike Snitzer return -EINVAL;
211ef548c55SMike Snitzer
212ef548c55SMike Snitzer } else if (test_bit(ERROR_WRITES, &fc->flags) && (fc->corrupt_bio_rw == WRITE)) {
213ef548c55SMike Snitzer ti->error = "error_writes is incompatible with corrupt_bio_byte with the WRITE flag set";
214ef548c55SMike Snitzer return -EINVAL;
215a3998799SMike Snitzer }
216a3998799SMike Snitzer
217aa7d7bc9SMikulas Patocka if (!fc->corrupt_bio_byte && !test_bit(ERROR_READS, &fc->flags) &&
2184c2c845bSMikulas Patocka !test_bit(DROP_WRITES, &fc->flags) && !test_bit(ERROR_WRITES, &fc->flags) &&
2194c2c845bSMikulas Patocka !fc->random_read_corrupt && !fc->random_write_corrupt) {
220aa7d7bc9SMikulas Patocka set_bit(ERROR_WRITES, &fc->flags);
221aa7d7bc9SMikulas Patocka set_bit(ERROR_READS, &fc->flags);
222aa7d7bc9SMikulas Patocka }
223aa7d7bc9SMikulas Patocka
224a3998799SMike Snitzer return 0;
225dfd068b0SMike Snitzer }
226dfd068b0SMike Snitzer
2273407ef52SJosef Bacik /*
228dfd068b0SMike Snitzer * Construct a flakey mapping:
229dfd068b0SMike Snitzer * <dev_path> <offset> <up interval> <down interval> [<#feature args> [<arg>]*]
230b26f5e3dSMike Snitzer *
231b26f5e3dSMike Snitzer * Feature args:
232b26f5e3dSMike Snitzer * [drop_writes]
233a3998799SMike Snitzer * [corrupt_bio_byte <Nth_byte> <direction> <value> <bio_flags>]
234a3998799SMike Snitzer *
235a3998799SMike Snitzer * Nth_byte starts from 1 for the first byte.
236a3998799SMike Snitzer * Direction is r for READ or w for WRITE.
237a3998799SMike Snitzer * bio_flags is ignored if 0.
2383407ef52SJosef Bacik */
flakey_ctr(struct dm_target * ti,unsigned int argc,char ** argv)2393407ef52SJosef Bacik static int flakey_ctr(struct dm_target *ti, unsigned int argc, char **argv)
2403407ef52SJosef Bacik {
2415916a22bSEric Biggers static const struct dm_arg _args[] = {
242dfd068b0SMike Snitzer {0, UINT_MAX, "Invalid up interval"},
243dfd068b0SMike Snitzer {0, UINT_MAX, "Invalid down interval"},
244dfd068b0SMike Snitzer };
2453407ef52SJosef Bacik
246dfd068b0SMike Snitzer int r;
247dfd068b0SMike Snitzer struct flakey_c *fc;
248dfd068b0SMike Snitzer unsigned long long tmpll;
249dfd068b0SMike Snitzer struct dm_arg_set as;
250dfd068b0SMike Snitzer const char *devname;
25131998ef1SMikulas Patocka char dummy;
252dfd068b0SMike Snitzer
253dfd068b0SMike Snitzer as.argc = argc;
254dfd068b0SMike Snitzer as.argv = argv;
255dfd068b0SMike Snitzer
256dfd068b0SMike Snitzer if (argc < 4) {
257dfd068b0SMike Snitzer ti->error = "Invalid argument count";
2583407ef52SJosef Bacik return -EINVAL;
2593407ef52SJosef Bacik }
2603407ef52SJosef Bacik
261b26f5e3dSMike Snitzer fc = kzalloc(sizeof(*fc), GFP_KERNEL);
2623407ef52SJosef Bacik if (!fc) {
26375e3a0f5SAlasdair G Kergon ti->error = "Cannot allocate context";
2643407ef52SJosef Bacik return -ENOMEM;
2653407ef52SJosef Bacik }
2663407ef52SJosef Bacik fc->start_time = jiffies;
2673407ef52SJosef Bacik
268dfd068b0SMike Snitzer devname = dm_shift_arg(&as);
2693407ef52SJosef Bacik
270e80d1c80SVivek Goyal r = -EINVAL;
271ef87bfc2SMilan Broz if (sscanf(dm_shift_arg(&as), "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) {
272dfd068b0SMike Snitzer ti->error = "Invalid device sector";
2733407ef52SJosef Bacik goto bad;
2743407ef52SJosef Bacik }
275dfd068b0SMike Snitzer fc->start = tmpll;
2763407ef52SJosef Bacik
277dfd068b0SMike Snitzer r = dm_read_arg(_args, &as, &fc->up_interval, &ti->error);
278dfd068b0SMike Snitzer if (r)
2793407ef52SJosef Bacik goto bad;
280dfd068b0SMike Snitzer
281dfd068b0SMike Snitzer r = dm_read_arg(_args, &as, &fc->down_interval, &ti->error);
282dfd068b0SMike Snitzer if (r)
283dfd068b0SMike Snitzer goto bad;
2843407ef52SJosef Bacik
2853407ef52SJosef Bacik if (!(fc->up_interval + fc->down_interval)) {
286dfd068b0SMike Snitzer ti->error = "Total (up + down) interval is zero";
287bff7e067SWei Yongjun r = -EINVAL;
2883407ef52SJosef Bacik goto bad;
2893407ef52SJosef Bacik }
2903407ef52SJosef Bacik
2913407ef52SJosef Bacik if (fc->up_interval + fc->down_interval < fc->up_interval) {
292dfd068b0SMike Snitzer ti->error = "Interval overflow";
293bff7e067SWei Yongjun r = -EINVAL;
2943407ef52SJosef Bacik goto bad;
2953407ef52SJosef Bacik }
2963407ef52SJosef Bacik
297b26f5e3dSMike Snitzer r = parse_features(&as, fc, ti);
298dfd068b0SMike Snitzer if (r)
299dfd068b0SMike Snitzer goto bad;
300dfd068b0SMike Snitzer
301e80d1c80SVivek Goyal r = dm_get_device(ti, devname, dm_table_get_mode(ti->table), &fc->dev);
302e80d1c80SVivek Goyal if (r) {
303dfd068b0SMike Snitzer ti->error = "Device lookup failed";
3043407ef52SJosef Bacik goto bad;
3053407ef52SJosef Bacik }
3063407ef52SJosef Bacik
30755a62eefSAlasdair G Kergon ti->num_flush_bios = 1;
30855a62eefSAlasdair G Kergon ti->num_discard_bios = 1;
30930187e1dSMike Snitzer ti->per_io_data_size = sizeof(struct per_bio_data);
3103407ef52SJosef Bacik ti->private = fc;
3113407ef52SJosef Bacik return 0;
3123407ef52SJosef Bacik
3133407ef52SJosef Bacik bad:
3143407ef52SJosef Bacik kfree(fc);
315e80d1c80SVivek Goyal return r;
3163407ef52SJosef Bacik }
3173407ef52SJosef Bacik
flakey_dtr(struct dm_target * ti)3183407ef52SJosef Bacik static void flakey_dtr(struct dm_target *ti)
3193407ef52SJosef Bacik {
3203407ef52SJosef Bacik struct flakey_c *fc = ti->private;
3213407ef52SJosef Bacik
3223407ef52SJosef Bacik dm_put_device(ti, fc->dev);
3233407ef52SJosef Bacik kfree(fc);
3243407ef52SJosef Bacik }
3253407ef52SJosef Bacik
flakey_map_sector(struct dm_target * ti,sector_t bi_sector)3263407ef52SJosef Bacik static sector_t flakey_map_sector(struct dm_target *ti, sector_t bi_sector)
3273407ef52SJosef Bacik {
3283407ef52SJosef Bacik struct flakey_c *fc = ti->private;
3293407ef52SJosef Bacik
33030e4171bSMike Snitzer return fc->start + dm_target_offset(ti, bi_sector);
3313407ef52SJosef Bacik }
3323407ef52SJosef Bacik
flakey_map_bio(struct dm_target * ti,struct bio * bio)3333407ef52SJosef Bacik static void flakey_map_bio(struct dm_target *ti, struct bio *bio)
3343407ef52SJosef Bacik {
3353407ef52SJosef Bacik struct flakey_c *fc = ti->private;
3363407ef52SJosef Bacik
33774d46992SChristoph Hellwig bio_set_dev(bio, fc->dev->bdev);
338e86f2b00SMike Snitzer bio->bi_iter.bi_sector = flakey_map_sector(ti, bio->bi_iter.bi_sector);
3393407ef52SJosef Bacik }
3403407ef52SJosef Bacik
corrupt_bio_common(struct bio * bio,unsigned int corrupt_bio_byte,unsigned char corrupt_bio_value)3414c2c845bSMikulas Patocka static void corrupt_bio_common(struct bio *bio, unsigned int corrupt_bio_byte,
3424c2c845bSMikulas Patocka unsigned char corrupt_bio_value)
343a3998799SMike Snitzer {
344a00f5276SSweet Tea struct bvec_iter iter;
345a00f5276SSweet Tea struct bio_vec bvec;
346a00f5276SSweet Tea
347a3998799SMike Snitzer /*
348a00f5276SSweet Tea * Overwrite the Nth byte of the bio's data, on whichever page
349a00f5276SSweet Tea * it falls.
350a3998799SMike Snitzer */
351a00f5276SSweet Tea bio_for_each_segment(bvec, bio, iter) {
352a00f5276SSweet Tea if (bio_iter_len(bio, iter) > corrupt_bio_byte) {
3534c2c845bSMikulas Patocka unsigned char *segment = bvec_kmap_local(&bvec);
3544c2c845bSMikulas Patocka segment[corrupt_bio_byte] = corrupt_bio_value;
3558eb29c4fSMikulas Patocka kunmap_local(segment);
356a3998799SMike Snitzer DMDEBUG("Corrupting data bio=%p by writing %u to byte %u "
357a00f5276SSweet Tea "(rw=%c bi_opf=%u bi_sector=%llu size=%u)\n",
3584c2c845bSMikulas Patocka bio, corrupt_bio_value, corrupt_bio_byte,
3591eff9d32SJens Axboe (bio_data_dir(bio) == WRITE) ? 'w' : 'r', bio->bi_opf,
3604c2c845bSMikulas Patocka (unsigned long long)bio->bi_iter.bi_sector,
3614c2c845bSMikulas Patocka bio->bi_iter.bi_size);
362a00f5276SSweet Tea break;
363a00f5276SSweet Tea }
364a00f5276SSweet Tea corrupt_bio_byte -= bio_iter_len(bio, iter);
365a3998799SMike Snitzer }
366a3998799SMike Snitzer }
367a3998799SMike Snitzer
corrupt_bio_data(struct bio * bio,struct flakey_c * fc)3684c2c845bSMikulas Patocka static void corrupt_bio_data(struct bio *bio, struct flakey_c *fc)
3694c2c845bSMikulas Patocka {
3704c2c845bSMikulas Patocka unsigned int corrupt_bio_byte = fc->corrupt_bio_byte - 1;
3714c2c845bSMikulas Patocka
3724c2c845bSMikulas Patocka if (!bio_has_data(bio))
3734c2c845bSMikulas Patocka return;
3744c2c845bSMikulas Patocka
3754c2c845bSMikulas Patocka corrupt_bio_common(bio, corrupt_bio_byte, fc->corrupt_bio_value);
3764c2c845bSMikulas Patocka }
3774c2c845bSMikulas Patocka
corrupt_bio_random(struct bio * bio)3784c2c845bSMikulas Patocka static void corrupt_bio_random(struct bio *bio)
3794c2c845bSMikulas Patocka {
3804c2c845bSMikulas Patocka unsigned int corrupt_byte;
3814c2c845bSMikulas Patocka unsigned char corrupt_value;
3824c2c845bSMikulas Patocka
3834c2c845bSMikulas Patocka if (!bio_has_data(bio))
3844c2c845bSMikulas Patocka return;
3854c2c845bSMikulas Patocka
3864c2c845bSMikulas Patocka corrupt_byte = get_random_u32() % bio->bi_iter.bi_size;
3874c2c845bSMikulas Patocka corrupt_value = get_random_u8();
3884c2c845bSMikulas Patocka
3894c2c845bSMikulas Patocka corrupt_bio_common(bio, corrupt_byte, corrupt_value);
3904c2c845bSMikulas Patocka }
3914c2c845bSMikulas Patocka
clone_free(struct bio * clone)3921d9a9438SMikulas Patocka static void clone_free(struct bio *clone)
3931d9a9438SMikulas Patocka {
3941d9a9438SMikulas Patocka struct folio_iter fi;
3951d9a9438SMikulas Patocka
3961d9a9438SMikulas Patocka if (clone->bi_vcnt > 0) { /* bio_for_each_folio_all crashes with an empty bio */
3971d9a9438SMikulas Patocka bio_for_each_folio_all(fi, clone)
3981d9a9438SMikulas Patocka folio_put(fi.folio);
3991d9a9438SMikulas Patocka }
4001d9a9438SMikulas Patocka
4011d9a9438SMikulas Patocka bio_uninit(clone);
4021d9a9438SMikulas Patocka kfree(clone);
4031d9a9438SMikulas Patocka }
4041d9a9438SMikulas Patocka
clone_endio(struct bio * clone)4051d9a9438SMikulas Patocka static void clone_endio(struct bio *clone)
4061d9a9438SMikulas Patocka {
4071d9a9438SMikulas Patocka struct bio *bio = clone->bi_private;
4081d9a9438SMikulas Patocka bio->bi_status = clone->bi_status;
4091d9a9438SMikulas Patocka clone_free(clone);
4101d9a9438SMikulas Patocka bio_endio(bio);
4111d9a9438SMikulas Patocka }
4121d9a9438SMikulas Patocka
clone_bio(struct dm_target * ti,struct flakey_c * fc,struct bio * bio)4131d9a9438SMikulas Patocka static struct bio *clone_bio(struct dm_target *ti, struct flakey_c *fc, struct bio *bio)
4141d9a9438SMikulas Patocka {
4151d9a9438SMikulas Patocka struct bio *clone;
4161d9a9438SMikulas Patocka unsigned size, remaining_size, nr_iovecs, order;
4171d9a9438SMikulas Patocka struct bvec_iter iter = bio->bi_iter;
4181d9a9438SMikulas Patocka
4191d9a9438SMikulas Patocka if (unlikely(bio->bi_iter.bi_size > UIO_MAXIOV << PAGE_SHIFT))
4201d9a9438SMikulas Patocka dm_accept_partial_bio(bio, UIO_MAXIOV << PAGE_SHIFT >> SECTOR_SHIFT);
4211d9a9438SMikulas Patocka
4221d9a9438SMikulas Patocka size = bio->bi_iter.bi_size;
4231d9a9438SMikulas Patocka nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
4241d9a9438SMikulas Patocka
4251d9a9438SMikulas Patocka clone = bio_kmalloc(nr_iovecs, GFP_NOIO | __GFP_NORETRY | __GFP_NOWARN);
4261d9a9438SMikulas Patocka if (!clone)
4271d9a9438SMikulas Patocka return NULL;
4281d9a9438SMikulas Patocka
4291d9a9438SMikulas Patocka bio_init(clone, fc->dev->bdev, bio->bi_inline_vecs, nr_iovecs, bio->bi_opf);
4301d9a9438SMikulas Patocka
4311d9a9438SMikulas Patocka clone->bi_iter.bi_sector = flakey_map_sector(ti, bio->bi_iter.bi_sector);
4321d9a9438SMikulas Patocka clone->bi_private = bio;
4331d9a9438SMikulas Patocka clone->bi_end_io = clone_endio;
4341d9a9438SMikulas Patocka
4351d9a9438SMikulas Patocka remaining_size = size;
4361d9a9438SMikulas Patocka
4375e0a760bSKirill A. Shutemov order = MAX_PAGE_ORDER;
4381d9a9438SMikulas Patocka while (remaining_size) {
4391d9a9438SMikulas Patocka struct page *pages;
4401d9a9438SMikulas Patocka unsigned size_to_add, to_copy;
4411d9a9438SMikulas Patocka unsigned char *virt;
4421d9a9438SMikulas Patocka unsigned remaining_order = __fls((remaining_size + PAGE_SIZE - 1) >> PAGE_SHIFT);
4431d9a9438SMikulas Patocka order = min(order, remaining_order);
4441d9a9438SMikulas Patocka
4451d9a9438SMikulas Patocka retry_alloc_pages:
4461d9a9438SMikulas Patocka pages = alloc_pages(GFP_NOIO | __GFP_NORETRY | __GFP_NOWARN | __GFP_COMP, order);
4471d9a9438SMikulas Patocka if (unlikely(!pages)) {
4481d9a9438SMikulas Patocka if (order) {
4491d9a9438SMikulas Patocka order--;
4501d9a9438SMikulas Patocka goto retry_alloc_pages;
4511d9a9438SMikulas Patocka }
4521d9a9438SMikulas Patocka clone_free(clone);
4531d9a9438SMikulas Patocka return NULL;
4541d9a9438SMikulas Patocka }
4551d9a9438SMikulas Patocka size_to_add = min((unsigned)PAGE_SIZE << order, remaining_size);
4561d9a9438SMikulas Patocka
4571d9a9438SMikulas Patocka virt = page_to_virt(pages);
4581d9a9438SMikulas Patocka to_copy = size_to_add;
4591d9a9438SMikulas Patocka do {
4601d9a9438SMikulas Patocka struct bio_vec bvec = bvec_iter_bvec(bio->bi_io_vec, iter);
4611d9a9438SMikulas Patocka unsigned this_step = min(bvec.bv_len, to_copy);
4621d9a9438SMikulas Patocka void *map = bvec_kmap_local(&bvec);
4631d9a9438SMikulas Patocka memcpy(virt, map, this_step);
4641d9a9438SMikulas Patocka kunmap_local(map);
4651d9a9438SMikulas Patocka
4661d9a9438SMikulas Patocka bvec_iter_advance(bio->bi_io_vec, &iter, this_step);
4671d9a9438SMikulas Patocka to_copy -= this_step;
4681d9a9438SMikulas Patocka virt += this_step;
4691d9a9438SMikulas Patocka } while (to_copy);
4701d9a9438SMikulas Patocka
4711d9a9438SMikulas Patocka __bio_add_page(clone, pages, size_to_add, 0);
4721d9a9438SMikulas Patocka remaining_size -= size_to_add;
4731d9a9438SMikulas Patocka }
4741d9a9438SMikulas Patocka
4751d9a9438SMikulas Patocka return clone;
4761d9a9438SMikulas Patocka }
4771d9a9438SMikulas Patocka
flakey_map(struct dm_target * ti,struct bio * bio)4787de3ee57SMikulas Patocka static int flakey_map(struct dm_target *ti, struct bio *bio)
4793407ef52SJosef Bacik {
4803407ef52SJosef Bacik struct flakey_c *fc = ti->private;
48186a3238cSHeinz Mauelshagen unsigned int elapsed;
482c7cfdf59SMikulas Patocka struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data));
4830ef0b471SHeinz Mauelshagen
484c7cfdf59SMikulas Patocka pb->bio_submitted = false;
4853407ef52SJosef Bacik
4862e2d6f7eSAjay Joshi if (op_is_zone_mgmt(bio_op(bio)))
487124c4454SDamien Le Moal goto map_bio;
488124c4454SDamien Le Moal
4893407ef52SJosef Bacik /* Are we alive ? */
4903407ef52SJosef Bacik elapsed = (jiffies - fc->start_time) / HZ;
491b26f5e3dSMike Snitzer if (elapsed % (fc->up_interval + fc->down_interval) >= fc->up_interval) {
4924c2c845bSMikulas Patocka bool corrupt_fixed, corrupt_random;
493a3998799SMike Snitzer /*
494a3998799SMike Snitzer * Flag this bio as submitted while down.
495a3998799SMike Snitzer */
496c7cfdf59SMikulas Patocka pb->bio_submitted = true;
4973407ef52SJosef Bacik
498b26f5e3dSMike Snitzer /*
499ef548c55SMike Snitzer * Error reads if neither corrupt_bio_byte or drop_writes or error_writes are set.
500299f6230SMike Snitzer * Otherwise, flakey_end_io() will decide if the reads should be modified.
501a3998799SMike Snitzer */
50299f3c90dSMike Snitzer if (bio_data_dir(bio) == READ) {
503aa7d7bc9SMikulas Patocka if (test_bit(ERROR_READS, &fc->flags))
504846785e6SChristoph Hellwig return DM_MAPIO_KILL;
505299f6230SMike Snitzer goto map_bio;
50699f3c90dSMike Snitzer }
507a3998799SMike Snitzer
508a3998799SMike Snitzer /*
509ef548c55SMike Snitzer * Drop or error writes?
510b26f5e3dSMike Snitzer */
511b26f5e3dSMike Snitzer if (test_bit(DROP_WRITES, &fc->flags)) {
5124246a0b6SChristoph Hellwig bio_endio(bio);
513b26f5e3dSMike Snitzer return DM_MAPIO_SUBMITTED;
51403b18887SHeinz Mauelshagen } else if (test_bit(ERROR_WRITES, &fc->flags)) {
515ef548c55SMike Snitzer bio_io_error(bio);
516ef548c55SMike Snitzer return DM_MAPIO_SUBMITTED;
517ef548c55SMike Snitzer }
518a3998799SMike Snitzer
519a3998799SMike Snitzer /*
520a3998799SMike Snitzer * Corrupt matching writes.
521a3998799SMike Snitzer */
5224c2c845bSMikulas Patocka corrupt_fixed = false;
5234c2c845bSMikulas Patocka corrupt_random = false;
5241d9a9438SMikulas Patocka if (fc->corrupt_bio_byte && fc->corrupt_bio_rw == WRITE) {
5254c2c845bSMikulas Patocka if (all_corrupt_bio_flags_match(bio, fc))
5264c2c845bSMikulas Patocka corrupt_fixed = true;
5274c2c845bSMikulas Patocka }
5284c2c845bSMikulas Patocka if (fc->random_write_corrupt) {
5294c2c845bSMikulas Patocka u64 rnd = get_random_u64();
5304c2c845bSMikulas Patocka u32 rem = do_div(rnd, PROBABILITY_BASE);
5314c2c845bSMikulas Patocka if (rem < fc->random_write_corrupt)
5324c2c845bSMikulas Patocka corrupt_random = true;
5334c2c845bSMikulas Patocka }
5344c2c845bSMikulas Patocka if (corrupt_fixed || corrupt_random) {
5351d9a9438SMikulas Patocka struct bio *clone = clone_bio(ti, fc, bio);
5361d9a9438SMikulas Patocka if (clone) {
5374c2c845bSMikulas Patocka if (corrupt_fixed)
5381d9a9438SMikulas Patocka corrupt_bio_data(clone, fc);
5394c2c845bSMikulas Patocka if (corrupt_random)
5404c2c845bSMikulas Patocka corrupt_bio_random(clone);
5411d9a9438SMikulas Patocka submit_bio(clone);
5421d9a9438SMikulas Patocka return DM_MAPIO_SUBMITTED;
5431d9a9438SMikulas Patocka }
544aa56b9b7SMikulas Patocka }
545b26f5e3dSMike Snitzer }
546b26f5e3dSMike Snitzer
547b26f5e3dSMike Snitzer map_bio:
5483407ef52SJosef Bacik flakey_map_bio(ti, bio);
5493407ef52SJosef Bacik
5503407ef52SJosef Bacik return DM_MAPIO_REMAPPED;
5513407ef52SJosef Bacik }
5523407ef52SJosef Bacik
flakey_end_io(struct dm_target * ti,struct bio * bio,blk_status_t * error)5534e4cbee9SChristoph Hellwig static int flakey_end_io(struct dm_target *ti, struct bio *bio,
5544e4cbee9SChristoph Hellwig blk_status_t *error)
555a3998799SMike Snitzer {
556a3998799SMike Snitzer struct flakey_c *fc = ti->private;
557c7cfdf59SMikulas Patocka struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data));
558a3998799SMike Snitzer
5592e2d6f7eSAjay Joshi if (op_is_zone_mgmt(bio_op(bio)))
560124c4454SDamien Le Moal return DM_ENDIO_DONE;
561124c4454SDamien Le Moal
5621be56909SChristoph Hellwig if (!*error && pb->bio_submitted && (bio_data_dir(bio) == READ)) {
563aa56b9b7SMikulas Patocka if (fc->corrupt_bio_byte) {
564aa56b9b7SMikulas Patocka if ((fc->corrupt_bio_rw == READ) &&
565299f6230SMike Snitzer all_corrupt_bio_flags_match(bio, fc)) {
566299f6230SMike Snitzer /*
567299f6230SMike Snitzer * Corrupt successful matching READs while in down state.
568299f6230SMike Snitzer */
569a3998799SMike Snitzer corrupt_bio_data(bio, fc);
570aa56b9b7SMikulas Patocka }
571aa7d7bc9SMikulas Patocka }
5724c2c845bSMikulas Patocka if (fc->random_read_corrupt) {
5734c2c845bSMikulas Patocka u64 rnd = get_random_u64();
5744c2c845bSMikulas Patocka u32 rem = do_div(rnd, PROBABILITY_BASE);
5754c2c845bSMikulas Patocka if (rem < fc->random_read_corrupt)
5764c2c845bSMikulas Patocka corrupt_bio_random(bio);
5774c2c845bSMikulas Patocka }
578aa7d7bc9SMikulas Patocka if (test_bit(ERROR_READS, &fc->flags)) {
579299f6230SMike Snitzer /*
580299f6230SMike Snitzer * Error read during the down_interval if drop_writes
581ef548c55SMike Snitzer * and error_writes were not configured.
582299f6230SMike Snitzer */
5834e4cbee9SChristoph Hellwig *error = BLK_STS_IOERR;
58499f3c90dSMike Snitzer }
585299f6230SMike Snitzer }
586a3998799SMike Snitzer
5871be56909SChristoph Hellwig return DM_ENDIO_DONE;
588a3998799SMike Snitzer }
589a3998799SMike Snitzer
flakey_status(struct dm_target * ti,status_type_t type,unsigned int status_flags,char * result,unsigned int maxlen)590fd7c092eSMikulas Patocka static void flakey_status(struct dm_target *ti, status_type_t type,
59186a3238cSHeinz Mauelshagen unsigned int status_flags, char *result, unsigned int maxlen)
5923407ef52SJosef Bacik {
59386a3238cSHeinz Mauelshagen unsigned int sz = 0;
5943407ef52SJosef Bacik struct flakey_c *fc = ti->private;
595aa7d7bc9SMikulas Patocka unsigned int error_reads, drop_writes, error_writes;
5963407ef52SJosef Bacik
5973407ef52SJosef Bacik switch (type) {
5983407ef52SJosef Bacik case STATUSTYPE_INFO:
5993407ef52SJosef Bacik result[0] = '\0';
6003407ef52SJosef Bacik break;
6013407ef52SJosef Bacik
6023407ef52SJosef Bacik case STATUSTYPE_TABLE:
603b26f5e3dSMike Snitzer DMEMIT("%s %llu %u %u", fc->dev->name,
6043407ef52SJosef Bacik (unsigned long long)fc->start, fc->up_interval,
6053407ef52SJosef Bacik fc->down_interval);
606b26f5e3dSMike Snitzer
607aa7d7bc9SMikulas Patocka error_reads = test_bit(ERROR_READS, &fc->flags);
608b26f5e3dSMike Snitzer drop_writes = test_bit(DROP_WRITES, &fc->flags);
609ef548c55SMike Snitzer error_writes = test_bit(ERROR_WRITES, &fc->flags);
6104c2c845bSMikulas Patocka DMEMIT(" %u", error_reads + drop_writes + error_writes +
6114c2c845bSMikulas Patocka (fc->corrupt_bio_byte > 0) * 5 +
6124c2c845bSMikulas Patocka (fc->random_read_corrupt > 0) * 2 +
6134c2c845bSMikulas Patocka (fc->random_write_corrupt > 0) * 2);
614a3998799SMike Snitzer
615aa7d7bc9SMikulas Patocka if (error_reads)
616aa7d7bc9SMikulas Patocka DMEMIT(" error_reads");
617b26f5e3dSMike Snitzer if (drop_writes)
618b26f5e3dSMike Snitzer DMEMIT(" drop_writes");
619ef548c55SMike Snitzer else if (error_writes)
620ef548c55SMike Snitzer DMEMIT(" error_writes");
621a3998799SMike Snitzer
622a3998799SMike Snitzer if (fc->corrupt_bio_byte)
623a3998799SMike Snitzer DMEMIT(" corrupt_bio_byte %u %c %u %u",
624a3998799SMike Snitzer fc->corrupt_bio_byte,
625a3998799SMike Snitzer (fc->corrupt_bio_rw == WRITE) ? 'w' : 'r',
626a3998799SMike Snitzer fc->corrupt_bio_value, fc->corrupt_bio_flags);
627a3998799SMike Snitzer
6284c2c845bSMikulas Patocka if (fc->random_read_corrupt > 0)
6294c2c845bSMikulas Patocka DMEMIT(" random_read_corrupt %u", fc->random_read_corrupt);
6304c2c845bSMikulas Patocka if (fc->random_write_corrupt > 0)
6314c2c845bSMikulas Patocka DMEMIT(" random_write_corrupt %u", fc->random_write_corrupt);
6324c2c845bSMikulas Patocka
6333407ef52SJosef Bacik break;
6348ec45662STushar Sugandhi
6358ec45662STushar Sugandhi case STATUSTYPE_IMA:
6368ec45662STushar Sugandhi result[0] = '\0';
6378ec45662STushar Sugandhi break;
6383407ef52SJosef Bacik }
6393407ef52SJosef Bacik }
6403407ef52SJosef Bacik
flakey_prepare_ioctl(struct dm_target * ti,struct block_device ** bdev)6415bd5e8d8SMike Snitzer static int flakey_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
6423407ef52SJosef Bacik {
6433407ef52SJosef Bacik struct flakey_c *fc = ti->private;
644e56f81e0SChristoph Hellwig
645e56f81e0SChristoph Hellwig *bdev = fc->dev->bdev;
6463407ef52SJosef Bacik
647ec8013beSPaolo Bonzini /*
648ec8013beSPaolo Bonzini * Only pass ioctls through if the device sizes match exactly.
649ec8013beSPaolo Bonzini */
6506dcbb52cSChristoph Hellwig if (fc->start || ti->len != bdev_nr_sectors((*bdev)))
651e56f81e0SChristoph Hellwig return 1;
652e56f81e0SChristoph Hellwig return 0;
6533407ef52SJosef Bacik }
6543407ef52SJosef Bacik
655e76239a3SChristoph Hellwig #ifdef CONFIG_BLK_DEV_ZONED
flakey_report_zones(struct dm_target * ti,struct dm_report_zones_args * args,unsigned int nr_zones)656d4100351SChristoph Hellwig static int flakey_report_zones(struct dm_target *ti,
657d4100351SChristoph Hellwig struct dm_report_zones_args *args, unsigned int nr_zones)
658e76239a3SChristoph Hellwig {
659e76239a3SChristoph Hellwig struct flakey_c *fc = ti->private;
660e76239a3SChristoph Hellwig
661912e8875SDamien Le Moal return dm_report_zones(fc->dev->bdev, fc->start,
662912e8875SDamien Le Moal flakey_map_sector(ti, args->next_sector),
663912e8875SDamien Le Moal args, nr_zones);
664e76239a3SChristoph Hellwig }
665e3290b94SMike Snitzer #else
666e3290b94SMike Snitzer #define flakey_report_zones NULL
667e76239a3SChristoph Hellwig #endif
668e76239a3SChristoph Hellwig
flakey_iterate_devices(struct dm_target * ti,iterate_devices_callout_fn fn,void * data)6693407ef52SJosef Bacik static int flakey_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
6703407ef52SJosef Bacik {
6713407ef52SJosef Bacik struct flakey_c *fc = ti->private;
6723407ef52SJosef Bacik
6733407ef52SJosef Bacik return fn(ti, fc->dev, fc->start, ti->len, data);
6743407ef52SJosef Bacik }
6753407ef52SJosef Bacik
6763407ef52SJosef Bacik static struct target_type flakey_target = {
6773407ef52SJosef Bacik .name = "flakey",
678124c4454SDamien Le Moal .version = {1, 5, 0},
6793db564b4SSatya Tangirala .features = DM_TARGET_ZONED_HM | DM_TARGET_PASSES_CRYPTO,
680e76239a3SChristoph Hellwig .report_zones = flakey_report_zones,
6813407ef52SJosef Bacik .module = THIS_MODULE,
6823407ef52SJosef Bacik .ctr = flakey_ctr,
6833407ef52SJosef Bacik .dtr = flakey_dtr,
6843407ef52SJosef Bacik .map = flakey_map,
685a3998799SMike Snitzer .end_io = flakey_end_io,
6863407ef52SJosef Bacik .status = flakey_status,
687e56f81e0SChristoph Hellwig .prepare_ioctl = flakey_prepare_ioctl,
6883407ef52SJosef Bacik .iterate_devices = flakey_iterate_devices,
6893407ef52SJosef Bacik };
6903664ff82SYangtao Li module_dm(flakey);
6913407ef52SJosef Bacik
6923407ef52SJosef Bacik MODULE_DESCRIPTION(DM_NAME " flakey target");
693*fa34e589SMike Snitzer MODULE_AUTHOR("Joe Thornber <dm-devel@lists.linux.dev>");
6943407ef52SJosef Bacik MODULE_LICENSE("GPL");
695