+++ /dev/null
-// 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");
projects / thirdparty / kernel / stable.git / commitdiff
