mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 19:29:37 +00:00
![Jens Axboe](/assets/img/avatar_default.png)
Since commit 63a4cc2486
, bio->bi_rw contains flags in the lower
portion and the op code in the higher portions. This means that
old code that relies on manually setting bi_rw is most likely
going to be broken. Instead of letting that brokeness linger,
rename the member, to force old and out-of-tree code to break
at compile time instead of at runtime.
No intended functional changes in this commit.
Signed-off-by: Jens Axboe <axboe@fb.com>
468 lines
10 KiB
C
468 lines
10 KiB
C
/*
|
|
* Copyright (C) 2001-2003 Sistina Software (UK) Limited.
|
|
*
|
|
* This file is released under the GPL.
|
|
*/
|
|
|
|
#include "dm.h"
|
|
#include <linux/device-mapper.h>
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/blkdev.h>
|
|
#include <linux/bio.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/log2.h>
|
|
|
|
#define DM_MSG_PREFIX "striped"
|
|
#define DM_IO_ERROR_THRESHOLD 15
|
|
|
|
struct stripe {
|
|
struct dm_dev *dev;
|
|
sector_t physical_start;
|
|
|
|
atomic_t error_count;
|
|
};
|
|
|
|
struct stripe_c {
|
|
uint32_t stripes;
|
|
int stripes_shift;
|
|
|
|
/* The size of this target / num. stripes */
|
|
sector_t stripe_width;
|
|
|
|
uint32_t chunk_size;
|
|
int chunk_size_shift;
|
|
|
|
/* Needed for handling events */
|
|
struct dm_target *ti;
|
|
|
|
/* Work struct used for triggering events*/
|
|
struct work_struct trigger_event;
|
|
|
|
struct stripe stripe[0];
|
|
};
|
|
|
|
/*
|
|
* An event is triggered whenever a drive
|
|
* drops out of a stripe volume.
|
|
*/
|
|
static void trigger_event(struct work_struct *work)
|
|
{
|
|
struct stripe_c *sc = container_of(work, struct stripe_c,
|
|
trigger_event);
|
|
dm_table_event(sc->ti->table);
|
|
}
|
|
|
|
static inline struct stripe_c *alloc_context(unsigned int stripes)
|
|
{
|
|
size_t len;
|
|
|
|
if (dm_array_too_big(sizeof(struct stripe_c), sizeof(struct stripe),
|
|
stripes))
|
|
return NULL;
|
|
|
|
len = sizeof(struct stripe_c) + (sizeof(struct stripe) * stripes);
|
|
|
|
return kmalloc(len, GFP_KERNEL);
|
|
}
|
|
|
|
/*
|
|
* Parse a single <dev> <sector> pair
|
|
*/
|
|
static int get_stripe(struct dm_target *ti, struct stripe_c *sc,
|
|
unsigned int stripe, char **argv)
|
|
{
|
|
unsigned long long start;
|
|
char dummy;
|
|
int ret;
|
|
|
|
if (sscanf(argv[1], "%llu%c", &start, &dummy) != 1)
|
|
return -EINVAL;
|
|
|
|
ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
|
|
&sc->stripe[stripe].dev);
|
|
if (ret)
|
|
return ret;
|
|
|
|
sc->stripe[stripe].physical_start = start;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Construct a striped mapping.
|
|
* <number of stripes> <chunk size> [<dev_path> <offset>]+
|
|
*/
|
|
static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
|
|
{
|
|
struct stripe_c *sc;
|
|
sector_t width, tmp_len;
|
|
uint32_t stripes;
|
|
uint32_t chunk_size;
|
|
int r;
|
|
unsigned int i;
|
|
|
|
if (argc < 2) {
|
|
ti->error = "Not enough arguments";
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (kstrtouint(argv[0], 10, &stripes) || !stripes) {
|
|
ti->error = "Invalid stripe count";
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (kstrtouint(argv[1], 10, &chunk_size) || !chunk_size) {
|
|
ti->error = "Invalid chunk_size";
|
|
return -EINVAL;
|
|
}
|
|
|
|
width = ti->len;
|
|
if (sector_div(width, stripes)) {
|
|
ti->error = "Target length not divisible by "
|
|
"number of stripes";
|
|
return -EINVAL;
|
|
}
|
|
|
|
tmp_len = width;
|
|
if (sector_div(tmp_len, chunk_size)) {
|
|
ti->error = "Target length not divisible by "
|
|
"chunk size";
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* Do we have enough arguments for that many stripes ?
|
|
*/
|
|
if (argc != (2 + 2 * stripes)) {
|
|
ti->error = "Not enough destinations "
|
|
"specified";
|
|
return -EINVAL;
|
|
}
|
|
|
|
sc = alloc_context(stripes);
|
|
if (!sc) {
|
|
ti->error = "Memory allocation for striped context "
|
|
"failed";
|
|
return -ENOMEM;
|
|
}
|
|
|
|
INIT_WORK(&sc->trigger_event, trigger_event);
|
|
|
|
/* Set pointer to dm target; used in trigger_event */
|
|
sc->ti = ti;
|
|
sc->stripes = stripes;
|
|
sc->stripe_width = width;
|
|
|
|
if (stripes & (stripes - 1))
|
|
sc->stripes_shift = -1;
|
|
else
|
|
sc->stripes_shift = __ffs(stripes);
|
|
|
|
r = dm_set_target_max_io_len(ti, chunk_size);
|
|
if (r) {
|
|
kfree(sc);
|
|
return r;
|
|
}
|
|
|
|
ti->num_flush_bios = stripes;
|
|
ti->num_discard_bios = stripes;
|
|
ti->num_write_same_bios = stripes;
|
|
|
|
sc->chunk_size = chunk_size;
|
|
if (chunk_size & (chunk_size - 1))
|
|
sc->chunk_size_shift = -1;
|
|
else
|
|
sc->chunk_size_shift = __ffs(chunk_size);
|
|
|
|
/*
|
|
* Get the stripe destinations.
|
|
*/
|
|
for (i = 0; i < stripes; i++) {
|
|
argv += 2;
|
|
|
|
r = get_stripe(ti, sc, i, argv);
|
|
if (r < 0) {
|
|
ti->error = "Couldn't parse stripe destination";
|
|
while (i--)
|
|
dm_put_device(ti, sc->stripe[i].dev);
|
|
kfree(sc);
|
|
return r;
|
|
}
|
|
atomic_set(&(sc->stripe[i].error_count), 0);
|
|
}
|
|
|
|
ti->private = sc;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void stripe_dtr(struct dm_target *ti)
|
|
{
|
|
unsigned int i;
|
|
struct stripe_c *sc = (struct stripe_c *) ti->private;
|
|
|
|
for (i = 0; i < sc->stripes; i++)
|
|
dm_put_device(ti, sc->stripe[i].dev);
|
|
|
|
flush_work(&sc->trigger_event);
|
|
kfree(sc);
|
|
}
|
|
|
|
static void stripe_map_sector(struct stripe_c *sc, sector_t sector,
|
|
uint32_t *stripe, sector_t *result)
|
|
{
|
|
sector_t chunk = dm_target_offset(sc->ti, sector);
|
|
sector_t chunk_offset;
|
|
|
|
if (sc->chunk_size_shift < 0)
|
|
chunk_offset = sector_div(chunk, sc->chunk_size);
|
|
else {
|
|
chunk_offset = chunk & (sc->chunk_size - 1);
|
|
chunk >>= sc->chunk_size_shift;
|
|
}
|
|
|
|
if (sc->stripes_shift < 0)
|
|
*stripe = sector_div(chunk, sc->stripes);
|
|
else {
|
|
*stripe = chunk & (sc->stripes - 1);
|
|
chunk >>= sc->stripes_shift;
|
|
}
|
|
|
|
if (sc->chunk_size_shift < 0)
|
|
chunk *= sc->chunk_size;
|
|
else
|
|
chunk <<= sc->chunk_size_shift;
|
|
|
|
*result = chunk + chunk_offset;
|
|
}
|
|
|
|
static void stripe_map_range_sector(struct stripe_c *sc, sector_t sector,
|
|
uint32_t target_stripe, sector_t *result)
|
|
{
|
|
uint32_t stripe;
|
|
|
|
stripe_map_sector(sc, sector, &stripe, result);
|
|
if (stripe == target_stripe)
|
|
return;
|
|
|
|
/* round down */
|
|
sector = *result;
|
|
if (sc->chunk_size_shift < 0)
|
|
*result -= sector_div(sector, sc->chunk_size);
|
|
else
|
|
*result = sector & ~(sector_t)(sc->chunk_size - 1);
|
|
|
|
if (target_stripe < stripe)
|
|
*result += sc->chunk_size; /* next chunk */
|
|
}
|
|
|
|
static int stripe_map_range(struct stripe_c *sc, struct bio *bio,
|
|
uint32_t target_stripe)
|
|
{
|
|
sector_t begin, end;
|
|
|
|
stripe_map_range_sector(sc, bio->bi_iter.bi_sector,
|
|
target_stripe, &begin);
|
|
stripe_map_range_sector(sc, bio_end_sector(bio),
|
|
target_stripe, &end);
|
|
if (begin < end) {
|
|
bio->bi_bdev = sc->stripe[target_stripe].dev->bdev;
|
|
bio->bi_iter.bi_sector = begin +
|
|
sc->stripe[target_stripe].physical_start;
|
|
bio->bi_iter.bi_size = to_bytes(end - begin);
|
|
return DM_MAPIO_REMAPPED;
|
|
} else {
|
|
/* The range doesn't map to the target stripe */
|
|
bio_endio(bio);
|
|
return DM_MAPIO_SUBMITTED;
|
|
}
|
|
}
|
|
|
|
static int stripe_map(struct dm_target *ti, struct bio *bio)
|
|
{
|
|
struct stripe_c *sc = ti->private;
|
|
uint32_t stripe;
|
|
unsigned target_bio_nr;
|
|
|
|
if (bio->bi_opf & REQ_PREFLUSH) {
|
|
target_bio_nr = dm_bio_get_target_bio_nr(bio);
|
|
BUG_ON(target_bio_nr >= sc->stripes);
|
|
bio->bi_bdev = sc->stripe[target_bio_nr].dev->bdev;
|
|
return DM_MAPIO_REMAPPED;
|
|
}
|
|
if (unlikely(bio_op(bio) == REQ_OP_DISCARD) ||
|
|
unlikely(bio_op(bio) == REQ_OP_WRITE_SAME)) {
|
|
target_bio_nr = dm_bio_get_target_bio_nr(bio);
|
|
BUG_ON(target_bio_nr >= sc->stripes);
|
|
return stripe_map_range(sc, bio, target_bio_nr);
|
|
}
|
|
|
|
stripe_map_sector(sc, bio->bi_iter.bi_sector,
|
|
&stripe, &bio->bi_iter.bi_sector);
|
|
|
|
bio->bi_iter.bi_sector += sc->stripe[stripe].physical_start;
|
|
bio->bi_bdev = sc->stripe[stripe].dev->bdev;
|
|
|
|
return DM_MAPIO_REMAPPED;
|
|
}
|
|
|
|
static long stripe_direct_access(struct dm_target *ti, sector_t sector,
|
|
void **kaddr, pfn_t *pfn, long size)
|
|
{
|
|
struct stripe_c *sc = ti->private;
|
|
uint32_t stripe;
|
|
struct block_device *bdev;
|
|
struct blk_dax_ctl dax = {
|
|
.size = size,
|
|
};
|
|
long ret;
|
|
|
|
stripe_map_sector(sc, sector, &stripe, &dax.sector);
|
|
|
|
dax.sector += sc->stripe[stripe].physical_start;
|
|
bdev = sc->stripe[stripe].dev->bdev;
|
|
|
|
ret = bdev_direct_access(bdev, &dax);
|
|
*kaddr = dax.addr;
|
|
*pfn = dax.pfn;
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Stripe status:
|
|
*
|
|
* INFO
|
|
* #stripes [stripe_name <stripe_name>] [group word count]
|
|
* [error count 'A|D' <error count 'A|D'>]
|
|
*
|
|
* TABLE
|
|
* #stripes [stripe chunk size]
|
|
* [stripe_name physical_start <stripe_name physical_start>]
|
|
*
|
|
*/
|
|
|
|
static void stripe_status(struct dm_target *ti, status_type_t type,
|
|
unsigned status_flags, char *result, unsigned maxlen)
|
|
{
|
|
struct stripe_c *sc = (struct stripe_c *) ti->private;
|
|
char buffer[sc->stripes + 1];
|
|
unsigned int sz = 0;
|
|
unsigned int i;
|
|
|
|
switch (type) {
|
|
case STATUSTYPE_INFO:
|
|
DMEMIT("%d ", sc->stripes);
|
|
for (i = 0; i < sc->stripes; i++) {
|
|
DMEMIT("%s ", sc->stripe[i].dev->name);
|
|
buffer[i] = atomic_read(&(sc->stripe[i].error_count)) ?
|
|
'D' : 'A';
|
|
}
|
|
buffer[i] = '\0';
|
|
DMEMIT("1 %s", buffer);
|
|
break;
|
|
|
|
case STATUSTYPE_TABLE:
|
|
DMEMIT("%d %llu", sc->stripes,
|
|
(unsigned long long)sc->chunk_size);
|
|
for (i = 0; i < sc->stripes; i++)
|
|
DMEMIT(" %s %llu", sc->stripe[i].dev->name,
|
|
(unsigned long long)sc->stripe[i].physical_start);
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int stripe_end_io(struct dm_target *ti, struct bio *bio, int error)
|
|
{
|
|
unsigned i;
|
|
char major_minor[16];
|
|
struct stripe_c *sc = ti->private;
|
|
|
|
if (!error)
|
|
return 0; /* I/O complete */
|
|
|
|
if ((error == -EWOULDBLOCK) && (bio->bi_opf & REQ_RAHEAD))
|
|
return error;
|
|
|
|
if (error == -EOPNOTSUPP)
|
|
return error;
|
|
|
|
memset(major_minor, 0, sizeof(major_minor));
|
|
sprintf(major_minor, "%d:%d",
|
|
MAJOR(disk_devt(bio->bi_bdev->bd_disk)),
|
|
MINOR(disk_devt(bio->bi_bdev->bd_disk)));
|
|
|
|
/*
|
|
* Test to see which stripe drive triggered the event
|
|
* and increment error count for all stripes on that device.
|
|
* If the error count for a given device exceeds the threshold
|
|
* value we will no longer trigger any further events.
|
|
*/
|
|
for (i = 0; i < sc->stripes; i++)
|
|
if (!strcmp(sc->stripe[i].dev->name, major_minor)) {
|
|
atomic_inc(&(sc->stripe[i].error_count));
|
|
if (atomic_read(&(sc->stripe[i].error_count)) <
|
|
DM_IO_ERROR_THRESHOLD)
|
|
schedule_work(&sc->trigger_event);
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
static int stripe_iterate_devices(struct dm_target *ti,
|
|
iterate_devices_callout_fn fn, void *data)
|
|
{
|
|
struct stripe_c *sc = ti->private;
|
|
int ret = 0;
|
|
unsigned i = 0;
|
|
|
|
do {
|
|
ret = fn(ti, sc->stripe[i].dev,
|
|
sc->stripe[i].physical_start,
|
|
sc->stripe_width, data);
|
|
} while (!ret && ++i < sc->stripes);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void stripe_io_hints(struct dm_target *ti,
|
|
struct queue_limits *limits)
|
|
{
|
|
struct stripe_c *sc = ti->private;
|
|
unsigned chunk_size = sc->chunk_size << SECTOR_SHIFT;
|
|
|
|
blk_limits_io_min(limits, chunk_size);
|
|
blk_limits_io_opt(limits, chunk_size * sc->stripes);
|
|
}
|
|
|
|
static struct target_type stripe_target = {
|
|
.name = "striped",
|
|
.version = {1, 6, 0},
|
|
.module = THIS_MODULE,
|
|
.ctr = stripe_ctr,
|
|
.dtr = stripe_dtr,
|
|
.map = stripe_map,
|
|
.end_io = stripe_end_io,
|
|
.status = stripe_status,
|
|
.iterate_devices = stripe_iterate_devices,
|
|
.io_hints = stripe_io_hints,
|
|
.direct_access = stripe_direct_access,
|
|
};
|
|
|
|
int __init dm_stripe_init(void)
|
|
{
|
|
int r;
|
|
|
|
r = dm_register_target(&stripe_target);
|
|
if (r < 0)
|
|
DMWARN("target registration failed");
|
|
|
|
return r;
|
|
}
|
|
|
|
void dm_stripe_exit(void)
|
|
{
|
|
dm_unregister_target(&stripe_target);
|
|
}
|