Release 4.14 drivers/md/faulty.c
/*
* faulty.c : Multiple Devices driver for Linux
*
* Copyright (C) 2004 Neil Brown
*
* fautly-device-simulator personality for md
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* You should have received a copy of the GNU General Public License
* (for example /usr/src/linux/COPYING); if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
* 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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Brown | 46 | 85.19% | 2 | 66.67% |
| Kent Overstreet | 8 | 14.81% | 1 | 33.33% |
| Total | 54 | 100.00% | 3 | 100.00% |
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Brown | 90 | 100.00% | 2 | 100.00% |
| Total | 90 | 100.00% | 2 | 100.00% |
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Brown | 150 | 100.00% | 2 | 100.00% |
| Total | 150 | 100.00% | 2 | 100.00% |
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Brown | 251 | 100.00% | 2 | 100.00% |
| Total | 251 | 100.00% | 2 | 100.00% |
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 generic_make_request,
* 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;
}
}
if (failit) {
struct bio *b = bio_clone_fast(bio, GFP_NOIO, mddev->bio_set);
bio_set_dev(b, conf->rdev->bdev);
b->bi_private = bio;
b->bi_end_io = faulty_fail;
bio = b;
} else
bio_set_dev(bio, conf->rdev->bdev);
generic_make_request(bio);
return true;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Brown | 261 | 87.88% | 7 | 50.00% |
| Kent Overstreet | 16 | 5.39% | 2 | 14.29% |
| Christoph Hellwig | 16 | 5.39% | 3 | 21.43% |
| Lei Ming | 3 | 1.01% | 1 | 7.14% |
| Shaohua Li | 1 | 0.34% | 1 | 7.14% |
| Total | 297 | 100.00% | 14 | 100.00% |
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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Brown | 239 | 99.58% | 3 | 75.00% |
| Shaohua Li | 1 | 0.42% | 1 | 25.00% |
| Total | 240 | 100.00% | 4 | 100.00% |
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Brown | 172 | 99.42% | 4 | 80.00% |
| Shaohua Li | 1 | 0.58% | 1 | 20.00% |
| Total | 173 | 100.00% | 5 | 100.00% |
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Dan J Williams | 38 | 95.00% | 1 | 50.00% |
| Neil Brown | 2 | 5.00% | 1 | 50.00% |
| Total | 40 | 100.00% | 2 | 100.00% |
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Brown | 103 | 64.78% | 5 | 45.45% |
| Eric Sandeen | 19 | 11.95% | 1 | 9.09% |
| Andre Noll | 15 | 9.43% | 1 | 9.09% |
| Dan J Williams | 11 | 6.92% | 2 | 18.18% |
| Sven Wegener | 9 | 5.66% | 1 | 9.09% |
| Shaohua Li | 2 | 1.26% | 1 | 9.09% |
| Total | 159 | 100.00% | 11 | 100.00% |
static void faulty_free(struct mddev *mddev, void *priv)
{
struct faulty_conf *conf = priv;
kfree(conf);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Brown | 27 | 100.00% | 4 | 100.00% |
| Total | 27 | 100.00% | 4 | 100.00% |
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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Brown | 16 | 100.00% | 1 | 100.00% |
| Total | 16 | 100.00% | 1 | 100.00% |
static void raid_exit(void)
{
unregister_md_personality(&faulty_personality);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Brown | 14 | 100.00% | 2 | 100.00% |
| Total | 14 | 100.00% | 2 | 100.00% |
module_init(raid_init);
module_exit(raid_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Fault injection personality for MD");
MODULE_ALIAS("md-personality-10"); /* faulty */
MODULE_ALIAS("md-faulty");
MODULE_ALIAS("md-level--5");
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Brown | 1558 | 90.90% | 19 | 55.88% |
| Dan J Williams | 54 | 3.15% | 2 | 5.88% |
| Kent Overstreet | 24 | 1.40% | 2 | 5.88% |
| Eric Sandeen | 19 | 1.11% | 1 | 2.94% |
| Christoph Hellwig | 16 | 0.93% | 3 | 8.82% |
| Andre Noll | 15 | 0.88% | 1 | 2.94% |
| Sven Wegener | 9 | 0.53% | 1 | 2.94% |
| Shaohua Li | 9 | 0.53% | 1 | 2.94% |
| Paul Gortmaker | 3 | 0.18% | 1 | 2.94% |
| Tejun Heo | 3 | 0.18% | 1 | 2.94% |
| Lei Ming | 3 | 0.18% | 1 | 2.94% |
| Lucas De Marchi | 1 | 0.06% | 1 | 2.94% |
| Total | 1714 | 100.00% | 34 | 100.00% |
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