diff options
Diffstat (limited to 'drivers/md/md-faulty.c')
-rw-r--r-- | drivers/md/md-faulty.c | 365 |
1 files changed, 0 insertions, 365 deletions
diff --git a/drivers/md/md-faulty.c b/drivers/md/md-faulty.c deleted file mode 100644 index a039e8e20f55..000000000000 --- a/drivers/md/md-faulty.c +++ /dev/null @@ -1,365 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * faulty.c : Multiple Devices driver for Linux - * - * Copyright (C) 2004 Neil Brown - * - * fautly-device-simulator personality for md - */ - - -/* - * The "faulty" personality causes some requests to fail. - * - * Possible failure modes are: - * reads fail "randomly" but succeed on retry - * writes fail "randomly" but succeed on retry - * reads for some address fail and then persist until a write - * reads for some address fail and then persist irrespective of write - * writes for some address fail and persist - * all writes fail - * - * Different modes can be active at a time, but only - * one can be set at array creation. Others can be added later. - * A mode can be one-shot or recurrent with the recurrence being - * once in every N requests. - * The bottom 5 bits of the "layout" indicate the mode. The - * remainder indicate a period, or 0 for one-shot. - * - * There is an implementation limit on the number of concurrently - * persisting-faulty blocks. When a new fault is requested that would - * exceed the limit, it is ignored. - * All current faults can be clear using a layout of "0". - * - * Requests are always sent to the device. If they are to fail, - * we clone the bio and insert a new b_end_io into the chain. - */ - -#define WriteTransient 0 -#define ReadTransient 1 -#define WritePersistent 2 -#define ReadPersistent 3 -#define WriteAll 4 /* doesn't go to device */ -#define ReadFixable 5 -#define Modes 6 - -#define ClearErrors 31 -#define ClearFaults 30 - -#define AllPersist 100 /* internal use only */ -#define NoPersist 101 - -#define ModeMask 0x1f -#define ModeShift 5 - -#define MaxFault 50 -#include <linux/blkdev.h> -#include <linux/module.h> -#include <linux/raid/md_u.h> -#include <linux/slab.h> -#include "md.h" -#include <linux/seq_file.h> - - -static void faulty_fail(struct bio *bio) -{ - struct bio *b = bio->bi_private; - - b->bi_iter.bi_size = bio->bi_iter.bi_size; - b->bi_iter.bi_sector = bio->bi_iter.bi_sector; - - bio_put(bio); - - bio_io_error(b); -} - -struct faulty_conf { - int period[Modes]; - atomic_t counters[Modes]; - sector_t faults[MaxFault]; - int modes[MaxFault]; - int nfaults; - struct md_rdev *rdev; -}; - -static int check_mode(struct faulty_conf *conf, int mode) -{ - if (conf->period[mode] == 0 && - atomic_read(&conf->counters[mode]) <= 0) - return 0; /* no failure, no decrement */ - - - if (atomic_dec_and_test(&conf->counters[mode])) { - if (conf->period[mode]) - atomic_set(&conf->counters[mode], conf->period[mode]); - return 1; - } - return 0; -} - -static int check_sector(struct faulty_conf *conf, sector_t start, sector_t end, int dir) -{ - /* If we find a ReadFixable sector, we fix it ... */ - int i; - for (i=0; i<conf->nfaults; i++) - if (conf->faults[i] >= start && - conf->faults[i] < end) { - /* found it ... */ - switch (conf->modes[i] * 2 + dir) { - case WritePersistent*2+WRITE: return 1; - case ReadPersistent*2+READ: return 1; - case ReadFixable*2+READ: return 1; - case ReadFixable*2+WRITE: - conf->modes[i] = NoPersist; - return 0; - case AllPersist*2+READ: - case AllPersist*2+WRITE: return 1; - default: - return 0; - } - } - return 0; -} - -static void add_sector(struct faulty_conf *conf, sector_t start, int mode) -{ - int i; - int n = conf->nfaults; - for (i=0; i<conf->nfaults; i++) - if (conf->faults[i] == start) { - switch(mode) { - case NoPersist: conf->modes[i] = mode; return; - case WritePersistent: - if (conf->modes[i] == ReadPersistent || - conf->modes[i] == ReadFixable) - conf->modes[i] = AllPersist; - else - conf->modes[i] = WritePersistent; - return; - case ReadPersistent: - if (conf->modes[i] == WritePersistent) - conf->modes[i] = AllPersist; - else - conf->modes[i] = ReadPersistent; - return; - case ReadFixable: - if (conf->modes[i] == WritePersistent || - conf->modes[i] == ReadPersistent) - conf->modes[i] = AllPersist; - else - conf->modes[i] = ReadFixable; - return; - } - } else if (conf->modes[i] == NoPersist) - n = i; - - if (n >= MaxFault) - return; - conf->faults[n] = start; - conf->modes[n] = mode; - if (conf->nfaults == n) - conf->nfaults = n+1; -} - -static bool faulty_make_request(struct mddev *mddev, struct bio *bio) -{ - struct faulty_conf *conf = mddev->private; - int failit = 0; - - if (bio_data_dir(bio) == WRITE) { - /* write request */ - if (atomic_read(&conf->counters[WriteAll])) { - /* special case - don't decrement, don't submit_bio_noacct, - * just fail immediately - */ - bio_io_error(bio); - return true; - } - - if (check_sector(conf, bio->bi_iter.bi_sector, - bio_end_sector(bio), WRITE)) - failit = 1; - if (check_mode(conf, WritePersistent)) { - add_sector(conf, bio->bi_iter.bi_sector, - WritePersistent); - failit = 1; - } - if (check_mode(conf, WriteTransient)) - failit = 1; - } else { - /* read request */ - if (check_sector(conf, bio->bi_iter.bi_sector, - bio_end_sector(bio), READ)) - failit = 1; - if (check_mode(conf, ReadTransient)) - failit = 1; - if (check_mode(conf, ReadPersistent)) { - add_sector(conf, bio->bi_iter.bi_sector, - ReadPersistent); - failit = 1; - } - if (check_mode(conf, ReadFixable)) { - add_sector(conf, bio->bi_iter.bi_sector, - ReadFixable); - failit = 1; - } - } - - md_account_bio(mddev, &bio); - if (failit) { - struct bio *b = bio_alloc_clone(conf->rdev->bdev, bio, GFP_NOIO, - &mddev->bio_set); - - b->bi_private = bio; - b->bi_end_io = faulty_fail; - bio = b; - } else - bio_set_dev(bio, conf->rdev->bdev); - - submit_bio_noacct(bio); - return true; -} - -static void faulty_status(struct seq_file *seq, struct mddev *mddev) -{ - struct faulty_conf *conf = mddev->private; - int n; - - if ((n=atomic_read(&conf->counters[WriteTransient])) != 0) - seq_printf(seq, " WriteTransient=%d(%d)", - n, conf->period[WriteTransient]); - - if ((n=atomic_read(&conf->counters[ReadTransient])) != 0) - seq_printf(seq, " ReadTransient=%d(%d)", - n, conf->period[ReadTransient]); - - if ((n=atomic_read(&conf->counters[WritePersistent])) != 0) - seq_printf(seq, " WritePersistent=%d(%d)", - n, conf->period[WritePersistent]); - - if ((n=atomic_read(&conf->counters[ReadPersistent])) != 0) - seq_printf(seq, " ReadPersistent=%d(%d)", - n, conf->period[ReadPersistent]); - - - if ((n=atomic_read(&conf->counters[ReadFixable])) != 0) - seq_printf(seq, " ReadFixable=%d(%d)", - n, conf->period[ReadFixable]); - - if ((n=atomic_read(&conf->counters[WriteAll])) != 0) - seq_printf(seq, " WriteAll"); - - seq_printf(seq, " nfaults=%d", conf->nfaults); -} - - -static int faulty_reshape(struct mddev *mddev) -{ - int mode = mddev->new_layout & ModeMask; - int count = mddev->new_layout >> ModeShift; - struct faulty_conf *conf = mddev->private; - - if (mddev->new_layout < 0) - return 0; - - /* new layout */ - if (mode == ClearFaults) - conf->nfaults = 0; - else if (mode == ClearErrors) { - int i; - for (i=0 ; i < Modes ; i++) { - conf->period[i] = 0; - atomic_set(&conf->counters[i], 0); - } - } else if (mode < Modes) { - conf->period[mode] = count; - if (!count) count++; - atomic_set(&conf->counters[mode], count); - } else - return -EINVAL; - mddev->new_layout = -1; - mddev->layout = -1; /* makes sure further changes come through */ - return 0; -} - -static sector_t faulty_size(struct mddev *mddev, sector_t sectors, int raid_disks) -{ - WARN_ONCE(raid_disks, - "%s does not support generic reshape\n", __func__); - - if (sectors == 0) - return mddev->dev_sectors; - - return sectors; -} - -static int faulty_run(struct mddev *mddev) -{ - struct md_rdev *rdev; - int i; - struct faulty_conf *conf; - - if (md_check_no_bitmap(mddev)) - return -EINVAL; - - conf = kmalloc(sizeof(*conf), GFP_KERNEL); - if (!conf) - return -ENOMEM; - - for (i=0; i<Modes; i++) { - atomic_set(&conf->counters[i], 0); - conf->period[i] = 0; - } - conf->nfaults = 0; - - rdev_for_each(rdev, mddev) { - conf->rdev = rdev; - disk_stack_limits(mddev->gendisk, rdev->bdev, - rdev->data_offset << 9); - } - - md_set_array_sectors(mddev, faulty_size(mddev, 0, 0)); - mddev->private = conf; - - faulty_reshape(mddev); - - return 0; -} - -static void faulty_free(struct mddev *mddev, void *priv) -{ - struct faulty_conf *conf = priv; - - kfree(conf); -} - -static struct md_personality faulty_personality = -{ - .name = "faulty", - .level = LEVEL_FAULTY, - .owner = THIS_MODULE, - .make_request = faulty_make_request, - .run = faulty_run, - .free = faulty_free, - .status = faulty_status, - .check_reshape = faulty_reshape, - .size = faulty_size, -}; - -static int __init raid_init(void) -{ - return register_md_personality(&faulty_personality); -} - -static void raid_exit(void) -{ - unregister_md_personality(&faulty_personality); -} - -module_init(raid_init); -module_exit(raid_exit); -MODULE_LICENSE("GPL"); -MODULE_DESCRIPTION("Fault injection personality for MD (deprecated)"); -MODULE_ALIAS("md-personality-10"); /* faulty */ -MODULE_ALIAS("md-faulty"); -MODULE_ALIAS("md-level--5"); |