linux/drivers/md/dm-raid.c
Jonathan Brassow 761becff01 DM RAID: Fix for "sync" directive ineffectiveness
There are two table arguments that can be given to a DM RAID target
that control whether the array is forced to (re)synchronize or skip
initialization: "sync" and "nosync".  When "sync" is given, we set
mddev->recovery_cp to 0 in order to cause the device to resynchronize.
This is insufficient if there is a bitmap in use, because the array
will simply look at the bitmap and see that there is no recovery
necessary.

The fix is to skip over the loading of the superblocks when "sync" is
given, causing new superblocks to be written that will force the array
to go through initialization (i.e. synchronization).

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:42:19 +11:00

1467 lines
38 KiB
C

/*
* Copyright (C) 2010-2011 Neil Brown
* Copyright (C) 2010-2011 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
#include <linux/slab.h>
#include <linux/module.h>
#include "md.h"
#include "raid1.h"
#include "raid5.h"
#include "raid10.h"
#include "bitmap.h"
#include <linux/device-mapper.h>
#define DM_MSG_PREFIX "raid"
/*
* The following flags are used by dm-raid.c to set up the array state.
* They must be cleared before md_run is called.
*/
#define FirstUse 10 /* rdev flag */
struct raid_dev {
/*
* Two DM devices, one to hold metadata and one to hold the
* actual data/parity. The reason for this is to not confuse
* ti->len and give more flexibility in altering size and
* characteristics.
*
* While it is possible for this device to be associated
* with a different physical device than the data_dev, it
* is intended for it to be the same.
* |--------- Physical Device ---------|
* |- meta_dev -|------ data_dev ------|
*/
struct dm_dev *meta_dev;
struct dm_dev *data_dev;
struct md_rdev rdev;
};
/*
* Flags for rs->print_flags field.
*/
#define DMPF_SYNC 0x1
#define DMPF_NOSYNC 0x2
#define DMPF_REBUILD 0x4
#define DMPF_DAEMON_SLEEP 0x8
#define DMPF_MIN_RECOVERY_RATE 0x10
#define DMPF_MAX_RECOVERY_RATE 0x20
#define DMPF_MAX_WRITE_BEHIND 0x40
#define DMPF_STRIPE_CACHE 0x80
#define DMPF_REGION_SIZE 0x100
#define DMPF_RAID10_COPIES 0x200
#define DMPF_RAID10_FORMAT 0x400
struct raid_set {
struct dm_target *ti;
uint32_t bitmap_loaded;
uint32_t print_flags;
struct mddev md;
struct raid_type *raid_type;
struct dm_target_callbacks callbacks;
struct raid_dev dev[0];
};
/* Supported raid types and properties. */
static struct raid_type {
const char *name; /* RAID algorithm. */
const char *descr; /* Descriptor text for logging. */
const unsigned parity_devs; /* # of parity devices. */
const unsigned minimal_devs; /* minimal # of devices in set. */
const unsigned level; /* RAID level. */
const unsigned algorithm; /* RAID algorithm. */
} raid_types[] = {
{"raid1", "RAID1 (mirroring)", 0, 2, 1, 0 /* NONE */},
{"raid10", "RAID10 (striped mirrors)", 0, 2, 10, UINT_MAX /* Varies */},
{"raid4", "RAID4 (dedicated parity disk)", 1, 2, 5, ALGORITHM_PARITY_0},
{"raid5_la", "RAID5 (left asymmetric)", 1, 2, 5, ALGORITHM_LEFT_ASYMMETRIC},
{"raid5_ra", "RAID5 (right asymmetric)", 1, 2, 5, ALGORITHM_RIGHT_ASYMMETRIC},
{"raid5_ls", "RAID5 (left symmetric)", 1, 2, 5, ALGORITHM_LEFT_SYMMETRIC},
{"raid5_rs", "RAID5 (right symmetric)", 1, 2, 5, ALGORITHM_RIGHT_SYMMETRIC},
{"raid6_zr", "RAID6 (zero restart)", 2, 4, 6, ALGORITHM_ROTATING_ZERO_RESTART},
{"raid6_nr", "RAID6 (N restart)", 2, 4, 6, ALGORITHM_ROTATING_N_RESTART},
{"raid6_nc", "RAID6 (N continue)", 2, 4, 6, ALGORITHM_ROTATING_N_CONTINUE}
};
static unsigned raid10_md_layout_to_copies(int layout)
{
return layout & 0xFF;
}
static int raid10_format_to_md_layout(char *format, unsigned copies)
{
/* 1 "far" copy, and 'copies' "near" copies */
return (1 << 8) | (copies & 0xFF);
}
static struct raid_type *get_raid_type(char *name)
{
int i;
for (i = 0; i < ARRAY_SIZE(raid_types); i++)
if (!strcmp(raid_types[i].name, name))
return &raid_types[i];
return NULL;
}
static struct raid_set *context_alloc(struct dm_target *ti, struct raid_type *raid_type, unsigned raid_devs)
{
unsigned i;
struct raid_set *rs;
if (raid_devs <= raid_type->parity_devs) {
ti->error = "Insufficient number of devices";
return ERR_PTR(-EINVAL);
}
rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL);
if (!rs) {
ti->error = "Cannot allocate raid context";
return ERR_PTR(-ENOMEM);
}
mddev_init(&rs->md);
rs->ti = ti;
rs->raid_type = raid_type;
rs->md.raid_disks = raid_devs;
rs->md.level = raid_type->level;
rs->md.new_level = rs->md.level;
rs->md.layout = raid_type->algorithm;
rs->md.new_layout = rs->md.layout;
rs->md.delta_disks = 0;
rs->md.recovery_cp = 0;
for (i = 0; i < raid_devs; i++)
md_rdev_init(&rs->dev[i].rdev);
/*
* Remaining items to be initialized by further RAID params:
* rs->md.persistent
* rs->md.external
* rs->md.chunk_sectors
* rs->md.new_chunk_sectors
* rs->md.dev_sectors
*/
return rs;
}
static void context_free(struct raid_set *rs)
{
int i;
for (i = 0; i < rs->md.raid_disks; i++) {
if (rs->dev[i].meta_dev)
dm_put_device(rs->ti, rs->dev[i].meta_dev);
md_rdev_clear(&rs->dev[i].rdev);
if (rs->dev[i].data_dev)
dm_put_device(rs->ti, rs->dev[i].data_dev);
}
kfree(rs);
}
/*
* For every device we have two words
* <meta_dev>: meta device name or '-' if missing
* <data_dev>: data device name or '-' if missing
*
* The following are permitted:
* - -
* - <data_dev>
* <meta_dev> <data_dev>
*
* The following is not allowed:
* <meta_dev> -
*
* This code parses those words. If there is a failure,
* the caller must use context_free to unwind the operations.
*/
static int dev_parms(struct raid_set *rs, char **argv)
{
int i;
int rebuild = 0;
int metadata_available = 0;
int ret = 0;
for (i = 0; i < rs->md.raid_disks; i++, argv += 2) {
rs->dev[i].rdev.raid_disk = i;
rs->dev[i].meta_dev = NULL;
rs->dev[i].data_dev = NULL;
/*
* There are no offsets, since there is a separate device
* for data and metadata.
*/
rs->dev[i].rdev.data_offset = 0;
rs->dev[i].rdev.mddev = &rs->md;
if (strcmp(argv[0], "-")) {
ret = dm_get_device(rs->ti, argv[0],
dm_table_get_mode(rs->ti->table),
&rs->dev[i].meta_dev);
rs->ti->error = "RAID metadata device lookup failure";
if (ret)
return ret;
rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
if (!rs->dev[i].rdev.sb_page)
return -ENOMEM;
}
if (!strcmp(argv[1], "-")) {
if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
(!rs->dev[i].rdev.recovery_offset)) {
rs->ti->error = "Drive designated for rebuild not specified";
return -EINVAL;
}
rs->ti->error = "No data device supplied with metadata device";
if (rs->dev[i].meta_dev)
return -EINVAL;
continue;
}
ret = dm_get_device(rs->ti, argv[1],
dm_table_get_mode(rs->ti->table),
&rs->dev[i].data_dev);
if (ret) {
rs->ti->error = "RAID device lookup failure";
return ret;
}
if (rs->dev[i].meta_dev) {
metadata_available = 1;
rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
}
rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
list_add(&rs->dev[i].rdev.same_set, &rs->md.disks);
if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
rebuild++;
}
if (metadata_available) {
rs->md.external = 0;
rs->md.persistent = 1;
rs->md.major_version = 2;
} else if (rebuild && !rs->md.recovery_cp) {
/*
* Without metadata, we will not be able to tell if the array
* is in-sync or not - we must assume it is not. Therefore,
* it is impossible to rebuild a drive.
*
* Even if there is metadata, the on-disk information may
* indicate that the array is not in-sync and it will then
* fail at that time.
*
* User could specify 'nosync' option if desperate.
*/
DMERR("Unable to rebuild drive while array is not in-sync");
rs->ti->error = "RAID device lookup failure";
return -EINVAL;
}
return 0;
}
/*
* validate_region_size
* @rs
* @region_size: region size in sectors. If 0, pick a size (4MiB default).
*
* Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
* Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
*
* Returns: 0 on success, -EINVAL on failure.
*/
static int validate_region_size(struct raid_set *rs, unsigned long region_size)
{
unsigned long min_region_size = rs->ti->len / (1 << 21);
if (!region_size) {
/*
* Choose a reasonable default. All figures in sectors.
*/
if (min_region_size > (1 << 13)) {
DMINFO("Choosing default region size of %lu sectors",
region_size);
region_size = min_region_size;
} else {
DMINFO("Choosing default region size of 4MiB");
region_size = 1 << 13; /* sectors */
}
} else {
/*
* Validate user-supplied value.
*/
if (region_size > rs->ti->len) {
rs->ti->error = "Supplied region size is too large";
return -EINVAL;
}
if (region_size < min_region_size) {
DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
region_size, min_region_size);
rs->ti->error = "Supplied region size is too small";
return -EINVAL;
}
if (!is_power_of_2(region_size)) {
rs->ti->error = "Region size is not a power of 2";
return -EINVAL;
}
if (region_size < rs->md.chunk_sectors) {
rs->ti->error = "Region size is smaller than the chunk size";
return -EINVAL;
}
}
/*
* Convert sectors to bytes.
*/
rs->md.bitmap_info.chunksize = (region_size << 9);
return 0;
}
/*
* validate_rebuild_devices
* @rs
*
* Determine if the devices specified for rebuild can result in a valid
* usable array that is capable of rebuilding the given devices.
*
* Returns: 0 on success, -EINVAL on failure.
*/
static int validate_rebuild_devices(struct raid_set *rs)
{
unsigned i, rebuild_cnt = 0;
unsigned rebuilds_per_group, copies, d;
if (!(rs->print_flags & DMPF_REBUILD))
return 0;
for (i = 0; i < rs->md.raid_disks; i++)
if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
rebuild_cnt++;
switch (rs->raid_type->level) {
case 1:
if (rebuild_cnt >= rs->md.raid_disks)
goto too_many;
break;
case 4:
case 5:
case 6:
if (rebuild_cnt > rs->raid_type->parity_devs)
goto too_many;
break;
case 10:
copies = raid10_md_layout_to_copies(rs->md.layout);
if (rebuild_cnt < copies)
break;
/*
* It is possible to have a higher rebuild count for RAID10,
* as long as the failed devices occur in different mirror
* groups (i.e. different stripes).
*
* Right now, we only allow for "near" copies. When other
* formats are added, we will have to check those too.
*
* When checking "near" format, make sure no adjacent devices
* have failed beyond what can be handled. In addition to the
* simple case where the number of devices is a multiple of the
* number of copies, we must also handle cases where the number
* of devices is not a multiple of the number of copies.
* E.g. dev1 dev2 dev3 dev4 dev5
* A A B B C
* C D D E E
*/
rebuilds_per_group = 0;
for (i = 0; i < rs->md.raid_disks * copies; i++) {
d = i % rs->md.raid_disks;
if (!test_bit(In_sync, &rs->dev[d].rdev.flags) &&
(++rebuilds_per_group >= copies))
goto too_many;
if (!((i + 1) % copies))
rebuilds_per_group = 0;
}
break;
default:
DMERR("The rebuild parameter is not supported for %s",
rs->raid_type->name);
rs->ti->error = "Rebuild not supported for this RAID type";
return -EINVAL;
}
return 0;
too_many:
rs->ti->error = "Too many rebuild devices specified";
return -EINVAL;
}
/*
* Possible arguments are...
* <chunk_size> [optional_args]
*
* Argument definitions
* <chunk_size> The number of sectors per disk that
* will form the "stripe"
* [[no]sync] Force or prevent recovery of the
* entire array
* [rebuild <idx>] Rebuild the drive indicated by the index
* [daemon_sleep <ms>] Time between bitmap daemon work to
* clear bits
* [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
* [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
* [write_mostly <idx>] Indicate a write mostly drive via index
* [max_write_behind <sectors>] See '-write-behind=' (man mdadm)
* [stripe_cache <sectors>] Stripe cache size for higher RAIDs
* [region_size <sectors>] Defines granularity of bitmap
*
* RAID10-only options:
* [raid10_copies <# copies>] Number of copies. (Default: 2)
* [raid10_format <near>] Layout algorithm. (Default: near)
*/
static int parse_raid_params(struct raid_set *rs, char **argv,
unsigned num_raid_params)
{
char *raid10_format = "near";
unsigned raid10_copies = 2;
unsigned i;
unsigned long value, region_size = 0;
sector_t sectors_per_dev = rs->ti->len;
sector_t max_io_len;
char *key;
/*
* First, parse the in-order required arguments
* "chunk_size" is the only argument of this type.
*/
if ((strict_strtoul(argv[0], 10, &value) < 0)) {
rs->ti->error = "Bad chunk size";
return -EINVAL;
} else if (rs->raid_type->level == 1) {
if (value)
DMERR("Ignoring chunk size parameter for RAID 1");
value = 0;
} else if (!is_power_of_2(value)) {
rs->ti->error = "Chunk size must be a power of 2";
return -EINVAL;
} else if (value < 8) {
rs->ti->error = "Chunk size value is too small";
return -EINVAL;
}
rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
argv++;
num_raid_params--;
/*
* We set each individual device as In_sync with a completed
* 'recovery_offset'. If there has been a device failure or
* replacement then one of the following cases applies:
*
* 1) User specifies 'rebuild'.
* - Device is reset when param is read.
* 2) A new device is supplied.
* - No matching superblock found, resets device.
* 3) Device failure was transient and returns on reload.
* - Failure noticed, resets device for bitmap replay.
* 4) Device hadn't completed recovery after previous failure.
* - Superblock is read and overrides recovery_offset.
*
* What is found in the superblocks of the devices is always
* authoritative, unless 'rebuild' or '[no]sync' was specified.
*/
for (i = 0; i < rs->md.raid_disks; i++) {
set_bit(In_sync, &rs->dev[i].rdev.flags);
rs->dev[i].rdev.recovery_offset = MaxSector;
}
/*
* Second, parse the unordered optional arguments
*/
for (i = 0; i < num_raid_params; i++) {
if (!strcasecmp(argv[i], "nosync")) {
rs->md.recovery_cp = MaxSector;
rs->print_flags |= DMPF_NOSYNC;
continue;
}
if (!strcasecmp(argv[i], "sync")) {
rs->md.recovery_cp = 0;
rs->print_flags |= DMPF_SYNC;
continue;
}
/* The rest of the optional arguments come in key/value pairs */
if ((i + 1) >= num_raid_params) {
rs->ti->error = "Wrong number of raid parameters given";
return -EINVAL;
}
key = argv[i++];
/* Parameters that take a string value are checked here. */
if (!strcasecmp(key, "raid10_format")) {
if (rs->raid_type->level != 10) {
rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
return -EINVAL;
}
if (strcmp("near", argv[i])) {
rs->ti->error = "Invalid 'raid10_format' value given";
return -EINVAL;
}
raid10_format = argv[i];
rs->print_flags |= DMPF_RAID10_FORMAT;
continue;
}
if (strict_strtoul(argv[i], 10, &value) < 0) {
rs->ti->error = "Bad numerical argument given in raid params";
return -EINVAL;
}
/* Parameters that take a numeric value are checked here */
if (!strcasecmp(key, "rebuild")) {
if (value >= rs->md.raid_disks) {
rs->ti->error = "Invalid rebuild index given";
return -EINVAL;
}
clear_bit(In_sync, &rs->dev[value].rdev.flags);
rs->dev[value].rdev.recovery_offset = 0;
rs->print_flags |= DMPF_REBUILD;
} else if (!strcasecmp(key, "write_mostly")) {
if (rs->raid_type->level != 1) {
rs->ti->error = "write_mostly option is only valid for RAID1";
return -EINVAL;
}
if (value >= rs->md.raid_disks) {
rs->ti->error = "Invalid write_mostly drive index given";
return -EINVAL;
}
set_bit(WriteMostly, &rs->dev[value].rdev.flags);
} else if (!strcasecmp(key, "max_write_behind")) {
if (rs->raid_type->level != 1) {
rs->ti->error = "max_write_behind option is only valid for RAID1";
return -EINVAL;
}
rs->print_flags |= DMPF_MAX_WRITE_BEHIND;
/*
* In device-mapper, we specify things in sectors, but
* MD records this value in kB
*/
value /= 2;
if (value > COUNTER_MAX) {
rs->ti->error = "Max write-behind limit out of range";
return -EINVAL;
}
rs->md.bitmap_info.max_write_behind = value;
} else if (!strcasecmp(key, "daemon_sleep")) {
rs->print_flags |= DMPF_DAEMON_SLEEP;
if (!value || (value > MAX_SCHEDULE_TIMEOUT)) {
rs->ti->error = "daemon sleep period out of range";
return -EINVAL;
}
rs->md.bitmap_info.daemon_sleep = value;
} else if (!strcasecmp(key, "stripe_cache")) {
rs->print_flags |= DMPF_STRIPE_CACHE;
/*
* In device-mapper, we specify things in sectors, but
* MD records this value in kB
*/
value /= 2;
if ((rs->raid_type->level != 5) &&
(rs->raid_type->level != 6)) {
rs->ti->error = "Inappropriate argument: stripe_cache";
return -EINVAL;
}
if (raid5_set_cache_size(&rs->md, (int)value)) {
rs->ti->error = "Bad stripe_cache size";
return -EINVAL;
}
} else if (!strcasecmp(key, "min_recovery_rate")) {
rs->print_flags |= DMPF_MIN_RECOVERY_RATE;
if (value > INT_MAX) {
rs->ti->error = "min_recovery_rate out of range";
return -EINVAL;
}
rs->md.sync_speed_min = (int)value;
} else if (!strcasecmp(key, "max_recovery_rate")) {
rs->print_flags |= DMPF_MAX_RECOVERY_RATE;
if (value > INT_MAX) {
rs->ti->error = "max_recovery_rate out of range";
return -EINVAL;
}
rs->md.sync_speed_max = (int)value;
} else if (!strcasecmp(key, "region_size")) {
rs->print_flags |= DMPF_REGION_SIZE;
region_size = value;
} else if (!strcasecmp(key, "raid10_copies") &&
(rs->raid_type->level == 10)) {
if ((value < 2) || (value > 0xFF)) {
rs->ti->error = "Bad value for 'raid10_copies'";
return -EINVAL;
}
rs->print_flags |= DMPF_RAID10_COPIES;
raid10_copies = value;
} else {
DMERR("Unable to parse RAID parameter: %s", key);
rs->ti->error = "Unable to parse RAID parameters";
return -EINVAL;
}
}
if (validate_region_size(rs, region_size))
return -EINVAL;
if (rs->md.chunk_sectors)
max_io_len = rs->md.chunk_sectors;
else
max_io_len = region_size;
if (dm_set_target_max_io_len(rs->ti, max_io_len))
return -EINVAL;
if (rs->raid_type->level == 10) {
if (raid10_copies > rs->md.raid_disks) {
rs->ti->error = "Not enough devices to satisfy specification";
return -EINVAL;
}
/* (Len * #mirrors) / #devices */
sectors_per_dev = rs->ti->len * raid10_copies;
sector_div(sectors_per_dev, rs->md.raid_disks);
rs->md.layout = raid10_format_to_md_layout(raid10_format,
raid10_copies);
rs->md.new_layout = rs->md.layout;
} else if ((rs->raid_type->level > 1) &&
sector_div(sectors_per_dev,
(rs->md.raid_disks - rs->raid_type->parity_devs))) {
rs->ti->error = "Target length not divisible by number of data devices";
return -EINVAL;
}
rs->md.dev_sectors = sectors_per_dev;
if (validate_rebuild_devices(rs))
return -EINVAL;
/* Assume there are no metadata devices until the drives are parsed */
rs->md.persistent = 0;
rs->md.external = 1;
return 0;
}
static void do_table_event(struct work_struct *ws)
{
struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
dm_table_event(rs->ti->table);
}
static int raid_is_congested(struct dm_target_callbacks *cb, int bits)
{
struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
if (rs->raid_type->level == 1)
return md_raid1_congested(&rs->md, bits);
if (rs->raid_type->level == 10)
return md_raid10_congested(&rs->md, bits);
return md_raid5_congested(&rs->md, bits);
}
/*
* This structure is never routinely used by userspace, unlike md superblocks.
* Devices with this superblock should only ever be accessed via device-mapper.
*/
#define DM_RAID_MAGIC 0x64526D44
struct dm_raid_superblock {
__le32 magic; /* "DmRd" */
__le32 features; /* Used to indicate possible future changes */
__le32 num_devices; /* Number of devices in this array. (Max 64) */
__le32 array_position; /* The position of this drive in the array */
__le64 events; /* Incremented by md when superblock updated */
__le64 failed_devices; /* Bit field of devices to indicate failures */
/*
* This offset tracks the progress of the repair or replacement of
* an individual drive.
*/
__le64 disk_recovery_offset;
/*
* This offset tracks the progress of the initial array
* synchronisation/parity calculation.
*/
__le64 array_resync_offset;
/*
* RAID characteristics
*/
__le32 level;
__le32 layout;
__le32 stripe_sectors;
__u8 pad[452]; /* Round struct to 512 bytes. */
/* Always set to 0 when writing. */
} __packed;
static int read_disk_sb(struct md_rdev *rdev, int size)
{
BUG_ON(!rdev->sb_page);
if (rdev->sb_loaded)
return 0;
if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, 1)) {
DMERR("Failed to read superblock of device at position %d",
rdev->raid_disk);
md_error(rdev->mddev, rdev);
return -EINVAL;
}
rdev->sb_loaded = 1;
return 0;
}
static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
{
int i;
uint64_t failed_devices;
struct dm_raid_superblock *sb;
struct raid_set *rs = container_of(mddev, struct raid_set, md);
sb = page_address(rdev->sb_page);
failed_devices = le64_to_cpu(sb->failed_devices);
for (i = 0; i < mddev->raid_disks; i++)
if (!rs->dev[i].data_dev ||
test_bit(Faulty, &(rs->dev[i].rdev.flags)))
failed_devices |= (1ULL << i);
memset(sb, 0, sizeof(*sb));
sb->magic = cpu_to_le32(DM_RAID_MAGIC);
sb->features = cpu_to_le32(0); /* No features yet */
sb->num_devices = cpu_to_le32(mddev->raid_disks);
sb->array_position = cpu_to_le32(rdev->raid_disk);
sb->events = cpu_to_le64(mddev->events);
sb->failed_devices = cpu_to_le64(failed_devices);
sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
sb->level = cpu_to_le32(mddev->level);
sb->layout = cpu_to_le32(mddev->layout);
sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
}
/*
* super_load
*
* This function creates a superblock if one is not found on the device
* and will decide which superblock to use if there's a choice.
*
* Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
*/
static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
{
int ret;
struct dm_raid_superblock *sb;
struct dm_raid_superblock *refsb;
uint64_t events_sb, events_refsb;
rdev->sb_start = 0;
rdev->sb_size = sizeof(*sb);
ret = read_disk_sb(rdev, rdev->sb_size);
if (ret)
return ret;
sb = page_address(rdev->sb_page);
/*
* Two cases that we want to write new superblocks and rebuild:
* 1) New device (no matching magic number)
* 2) Device specified for rebuild (!In_sync w/ offset == 0)
*/
if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
(!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
super_sync(rdev->mddev, rdev);
set_bit(FirstUse, &rdev->flags);
/* Force writing of superblocks to disk */
set_bit(MD_CHANGE_DEVS, &rdev->mddev->flags);
/* Any superblock is better than none, choose that if given */
return refdev ? 0 : 1;
}
if (!refdev)
return 1;
events_sb = le64_to_cpu(sb->events);
refsb = page_address(refdev->sb_page);
events_refsb = le64_to_cpu(refsb->events);
return (events_sb > events_refsb) ? 1 : 0;
}
static int super_init_validation(struct mddev *mddev, struct md_rdev *rdev)
{
int role;
struct raid_set *rs = container_of(mddev, struct raid_set, md);
uint64_t events_sb;
uint64_t failed_devices;
struct dm_raid_superblock *sb;
uint32_t new_devs = 0;
uint32_t rebuilds = 0;
struct md_rdev *r;
struct dm_raid_superblock *sb2;
sb = page_address(rdev->sb_page);
events_sb = le64_to_cpu(sb->events);
failed_devices = le64_to_cpu(sb->failed_devices);
/*
* Initialise to 1 if this is a new superblock.
*/
mddev->events = events_sb ? : 1;
/*
* Reshaping is not currently allowed
*/
if ((le32_to_cpu(sb->level) != mddev->level) ||
(le32_to_cpu(sb->layout) != mddev->layout) ||
(le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors)) {
DMERR("Reshaping arrays not yet supported.");
return -EINVAL;
}
/* We can only change the number of devices in RAID1 right now */
if ((rs->raid_type->level != 1) &&
(le32_to_cpu(sb->num_devices) != mddev->raid_disks)) {
DMERR("Reshaping arrays not yet supported.");
return -EINVAL;
}
if (!(rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC)))
mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
/*
* During load, we set FirstUse if a new superblock was written.
* There are two reasons we might not have a superblock:
* 1) The array is brand new - in which case, all of the
* devices must have their In_sync bit set. Also,
* recovery_cp must be 0, unless forced.
* 2) This is a new device being added to an old array
* and the new device needs to be rebuilt - in which
* case the In_sync bit will /not/ be set and
* recovery_cp must be MaxSector.
*/
rdev_for_each(r, mddev) {
if (!test_bit(In_sync, &r->flags)) {
DMINFO("Device %d specified for rebuild: "
"Clearing superblock", r->raid_disk);
rebuilds++;
} else if (test_bit(FirstUse, &r->flags))
new_devs++;
}
if (!rebuilds) {
if (new_devs == mddev->raid_disks) {
DMINFO("Superblocks created for new array");
set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
} else if (new_devs) {
DMERR("New device injected "
"into existing array without 'rebuild' "
"parameter specified");
return -EINVAL;
}
} else if (new_devs) {
DMERR("'rebuild' devices cannot be "
"injected into an array with other first-time devices");
return -EINVAL;
} else if (mddev->recovery_cp != MaxSector) {
DMERR("'rebuild' specified while array is not in-sync");
return -EINVAL;
}
/*
* Now we set the Faulty bit for those devices that are
* recorded in the superblock as failed.
*/
rdev_for_each(r, mddev) {
if (!r->sb_page)
continue;
sb2 = page_address(r->sb_page);
sb2->failed_devices = 0;
/*
* Check for any device re-ordering.
*/
if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
role = le32_to_cpu(sb2->array_position);
if (role != r->raid_disk) {
if (rs->raid_type->level != 1) {
rs->ti->error = "Cannot change device "
"positions in RAID array";
return -EINVAL;
}
DMINFO("RAID1 device #%d now at position #%d",
role, r->raid_disk);
}
/*
* Partial recovery is performed on
* returning failed devices.
*/
if (failed_devices & (1 << role))
set_bit(Faulty, &r->flags);
}
}
return 0;
}
static int super_validate(struct mddev *mddev, struct md_rdev *rdev)
{
struct dm_raid_superblock *sb = page_address(rdev->sb_page);
/*
* If mddev->events is not set, we know we have not yet initialized
* the array.
*/
if (!mddev->events && super_init_validation(mddev, rdev))
return -EINVAL;
mddev->bitmap_info.offset = 4096 >> 9; /* Enable bitmap creation */
rdev->mddev->bitmap_info.default_offset = 4096 >> 9;
if (!test_bit(FirstUse, &rdev->flags)) {
rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
if (rdev->recovery_offset != MaxSector)
clear_bit(In_sync, &rdev->flags);
}
/*
* If a device comes back, set it as not In_sync and no longer faulty.
*/
if (test_bit(Faulty, &rdev->flags)) {
clear_bit(Faulty, &rdev->flags);
clear_bit(In_sync, &rdev->flags);
rdev->saved_raid_disk = rdev->raid_disk;
rdev->recovery_offset = 0;
}
clear_bit(FirstUse, &rdev->flags);
return 0;
}
/*
* Analyse superblocks and select the freshest.
*/
static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
{
int ret;
unsigned redundancy = 0;
struct raid_dev *dev;
struct md_rdev *rdev, *tmp, *freshest;
struct mddev *mddev = &rs->md;
switch (rs->raid_type->level) {
case 1:
redundancy = rs->md.raid_disks - 1;
break;
case 4:
case 5:
case 6:
redundancy = rs->raid_type->parity_devs;
break;
case 10:
redundancy = raid10_md_layout_to_copies(mddev->layout) - 1;
break;
default:
ti->error = "Unknown RAID type";
return -EINVAL;
}
freshest = NULL;
rdev_for_each_safe(rdev, tmp, mddev) {
/*
* Skipping super_load due to DMPF_SYNC will cause
* the array to undergo initialization again as
* though it were new. This is the intended effect
* of the "sync" directive.
*
* When reshaping capability is added, we must ensure
* that the "sync" directive is disallowed during the
* reshape.
*/
if (rs->print_flags & DMPF_SYNC)
continue;
if (!rdev->meta_bdev)
continue;
ret = super_load(rdev, freshest);
switch (ret) {
case 1:
freshest = rdev;
break;
case 0:
break;
default:
dev = container_of(rdev, struct raid_dev, rdev);
if (redundancy--) {
if (dev->meta_dev)
dm_put_device(ti, dev->meta_dev);
dev->meta_dev = NULL;
rdev->meta_bdev = NULL;
if (rdev->sb_page)
put_page(rdev->sb_page);
rdev->sb_page = NULL;
rdev->sb_loaded = 0;
/*
* We might be able to salvage the data device
* even though the meta device has failed. For
* now, we behave as though '- -' had been
* set for this device in the table.
*/
if (dev->data_dev)
dm_put_device(ti, dev->data_dev);
dev->data_dev = NULL;
rdev->bdev = NULL;
list_del(&rdev->same_set);
continue;
}
ti->error = "Failed to load superblock";
return ret;
}
}
if (!freshest)
return 0;
/*
* Validation of the freshest device provides the source of
* validation for the remaining devices.
*/
ti->error = "Unable to assemble array: Invalid superblocks";
if (super_validate(mddev, freshest))
return -EINVAL;
rdev_for_each(rdev, mddev)
if ((rdev != freshest) && super_validate(mddev, rdev))
return -EINVAL;
return 0;
}
/*
* Construct a RAID4/5/6 mapping:
* Args:
* <raid_type> <#raid_params> <raid_params> \
* <#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> }
*
* <raid_params> varies by <raid_type>. See 'parse_raid_params' for
* details on possible <raid_params>.
*/
static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
{
int ret;
struct raid_type *rt;
unsigned long num_raid_params, num_raid_devs;
struct raid_set *rs = NULL;
/* Must have at least <raid_type> <#raid_params> */
if (argc < 2) {
ti->error = "Too few arguments";
return -EINVAL;
}
/* raid type */
rt = get_raid_type(argv[0]);
if (!rt) {
ti->error = "Unrecognised raid_type";
return -EINVAL;
}
argc--;
argv++;
/* number of RAID parameters */
if (strict_strtoul(argv[0], 10, &num_raid_params) < 0) {
ti->error = "Cannot understand number of RAID parameters";
return -EINVAL;
}
argc--;
argv++;
/* Skip over RAID params for now and find out # of devices */
if (num_raid_params + 1 > argc) {
ti->error = "Arguments do not agree with counts given";
return -EINVAL;
}
if ((strict_strtoul(argv[num_raid_params], 10, &num_raid_devs) < 0) ||
(num_raid_devs >= INT_MAX)) {
ti->error = "Cannot understand number of raid devices";
return -EINVAL;
}
rs = context_alloc(ti, rt, (unsigned)num_raid_devs);
if (IS_ERR(rs))
return PTR_ERR(rs);
ret = parse_raid_params(rs, argv, (unsigned)num_raid_params);
if (ret)
goto bad;
ret = -EINVAL;
argc -= num_raid_params + 1; /* +1: we already have num_raid_devs */
argv += num_raid_params + 1;
if (argc != (num_raid_devs * 2)) {
ti->error = "Supplied RAID devices does not match the count given";
goto bad;
}
ret = dev_parms(rs, argv);
if (ret)
goto bad;
rs->md.sync_super = super_sync;
ret = analyse_superblocks(ti, rs);
if (ret)
goto bad;
INIT_WORK(&rs->md.event_work, do_table_event);
ti->private = rs;
ti->num_flush_requests = 1;
mutex_lock(&rs->md.reconfig_mutex);
ret = md_run(&rs->md);
rs->md.in_sync = 0; /* Assume already marked dirty */
mutex_unlock(&rs->md.reconfig_mutex);
if (ret) {
ti->error = "Fail to run raid array";
goto bad;
}
if (ti->len != rs->md.array_sectors) {
ti->error = "Array size does not match requested target length";
ret = -EINVAL;
goto size_mismatch;
}
rs->callbacks.congested_fn = raid_is_congested;
dm_table_add_target_callbacks(ti->table, &rs->callbacks);
mddev_suspend(&rs->md);
return 0;
size_mismatch:
md_stop(&rs->md);
bad:
context_free(rs);
return ret;
}
static void raid_dtr(struct dm_target *ti)
{
struct raid_set *rs = ti->private;
list_del_init(&rs->callbacks.list);
md_stop(&rs->md);
context_free(rs);
}
static int raid_map(struct dm_target *ti, struct bio *bio, union map_info *map_context)
{
struct raid_set *rs = ti->private;
struct mddev *mddev = &rs->md;
mddev->pers->make_request(mddev, bio);
return DM_MAPIO_SUBMITTED;
}
static int raid_status(struct dm_target *ti, status_type_t type,
unsigned status_flags, char *result, unsigned maxlen)
{
struct raid_set *rs = ti->private;
unsigned raid_param_cnt = 1; /* at least 1 for chunksize */
unsigned sz = 0;
int i, array_in_sync = 0;
sector_t sync;
switch (type) {
case STATUSTYPE_INFO:
DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks);
if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery))
sync = rs->md.curr_resync_completed;
else
sync = rs->md.recovery_cp;
if (sync >= rs->md.resync_max_sectors) {
array_in_sync = 1;
sync = rs->md.resync_max_sectors;
} else {
/*
* The array may be doing an initial sync, or it may
* be rebuilding individual components. If all the
* devices are In_sync, then it is the array that is
* being initialized.
*/
for (i = 0; i < rs->md.raid_disks; i++)
if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
array_in_sync = 1;
}
/*
* Status characters:
* 'D' = Dead/Failed device
* 'a' = Alive but not in-sync
* 'A' = Alive and in-sync
*/
for (i = 0; i < rs->md.raid_disks; i++) {
if (test_bit(Faulty, &rs->dev[i].rdev.flags))
DMEMIT("D");
else if (!array_in_sync ||
!test_bit(In_sync, &rs->dev[i].rdev.flags))
DMEMIT("a");
else
DMEMIT("A");
}
/*
* In-sync ratio:
* The in-sync ratio shows the progress of:
* - Initializing the array
* - Rebuilding a subset of devices of the array
* The user can distinguish between the two by referring
* to the status characters.
*/
DMEMIT(" %llu/%llu",
(unsigned long long) sync,
(unsigned long long) rs->md.resync_max_sectors);
break;
case STATUSTYPE_TABLE:
/* The string you would use to construct this array */
for (i = 0; i < rs->md.raid_disks; i++) {
if ((rs->print_flags & DMPF_REBUILD) &&
rs->dev[i].data_dev &&
!test_bit(In_sync, &rs->dev[i].rdev.flags))
raid_param_cnt += 2; /* for rebuilds */
if (rs->dev[i].data_dev &&
test_bit(WriteMostly, &rs->dev[i].rdev.flags))
raid_param_cnt += 2;
}
raid_param_cnt += (hweight32(rs->print_flags & ~DMPF_REBUILD) * 2);
if (rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC))
raid_param_cnt--;
DMEMIT("%s %u %u", rs->raid_type->name,
raid_param_cnt, rs->md.chunk_sectors);
if ((rs->print_flags & DMPF_SYNC) &&
(rs->md.recovery_cp == MaxSector))
DMEMIT(" sync");
if (rs->print_flags & DMPF_NOSYNC)
DMEMIT(" nosync");
for (i = 0; i < rs->md.raid_disks; i++)
if ((rs->print_flags & DMPF_REBUILD) &&
rs->dev[i].data_dev &&
!test_bit(In_sync, &rs->dev[i].rdev.flags))
DMEMIT(" rebuild %u", i);
if (rs->print_flags & DMPF_DAEMON_SLEEP)
DMEMIT(" daemon_sleep %lu",
rs->md.bitmap_info.daemon_sleep);
if (rs->print_flags & DMPF_MIN_RECOVERY_RATE)
DMEMIT(" min_recovery_rate %d", rs->md.sync_speed_min);
if (rs->print_flags & DMPF_MAX_RECOVERY_RATE)
DMEMIT(" max_recovery_rate %d", rs->md.sync_speed_max);
for (i = 0; i < rs->md.raid_disks; i++)
if (rs->dev[i].data_dev &&
test_bit(WriteMostly, &rs->dev[i].rdev.flags))
DMEMIT(" write_mostly %u", i);
if (rs->print_flags & DMPF_MAX_WRITE_BEHIND)
DMEMIT(" max_write_behind %lu",
rs->md.bitmap_info.max_write_behind);
if (rs->print_flags & DMPF_STRIPE_CACHE) {
struct r5conf *conf = rs->md.private;
/* convert from kiB to sectors */
DMEMIT(" stripe_cache %d",
conf ? conf->max_nr_stripes * 2 : 0);
}
if (rs->print_flags & DMPF_REGION_SIZE)
DMEMIT(" region_size %lu",
rs->md.bitmap_info.chunksize >> 9);
if (rs->print_flags & DMPF_RAID10_COPIES)
DMEMIT(" raid10_copies %u",
raid10_md_layout_to_copies(rs->md.layout));
if (rs->print_flags & DMPF_RAID10_FORMAT)
DMEMIT(" raid10_format near");
DMEMIT(" %d", rs->md.raid_disks);
for (i = 0; i < rs->md.raid_disks; i++) {
if (rs->dev[i].meta_dev)
DMEMIT(" %s", rs->dev[i].meta_dev->name);
else
DMEMIT(" -");
if (rs->dev[i].data_dev)
DMEMIT(" %s", rs->dev[i].data_dev->name);
else
DMEMIT(" -");
}
}
return 0;
}
static int raid_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
{
struct raid_set *rs = ti->private;
unsigned i;
int ret = 0;
for (i = 0; !ret && i < rs->md.raid_disks; i++)
if (rs->dev[i].data_dev)
ret = fn(ti,
rs->dev[i].data_dev,
0, /* No offset on data devs */
rs->md.dev_sectors,
data);
return ret;
}
static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
struct raid_set *rs = ti->private;
unsigned chunk_size = rs->md.chunk_sectors << 9;
struct r5conf *conf = rs->md.private;
blk_limits_io_min(limits, chunk_size);
blk_limits_io_opt(limits, chunk_size * (conf->raid_disks - conf->max_degraded));
}
static void raid_presuspend(struct dm_target *ti)
{
struct raid_set *rs = ti->private;
md_stop_writes(&rs->md);
}
static void raid_postsuspend(struct dm_target *ti)
{
struct raid_set *rs = ti->private;
mddev_suspend(&rs->md);
}
static void raid_resume(struct dm_target *ti)
{
struct raid_set *rs = ti->private;
set_bit(MD_CHANGE_DEVS, &rs->md.flags);
if (!rs->bitmap_loaded) {
bitmap_load(&rs->md);
rs->bitmap_loaded = 1;
}
clear_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
mddev_resume(&rs->md);
}
static struct target_type raid_target = {
.name = "raid",
.version = {1, 3, 1},
.module = THIS_MODULE,
.ctr = raid_ctr,
.dtr = raid_dtr,
.map = raid_map,
.status = raid_status,
.iterate_devices = raid_iterate_devices,
.io_hints = raid_io_hints,
.presuspend = raid_presuspend,
.postsuspend = raid_postsuspend,
.resume = raid_resume,
};
static int __init dm_raid_init(void)
{
return dm_register_target(&raid_target);
}
static void __exit dm_raid_exit(void)
{
dm_unregister_target(&raid_target);
}
module_init(dm_raid_init);
module_exit(dm_raid_exit);
MODULE_DESCRIPTION(DM_NAME " raid4/5/6 target");
MODULE_ALIAS("dm-raid1");
MODULE_ALIAS("dm-raid10");
MODULE_ALIAS("dm-raid4");
MODULE_ALIAS("dm-raid5");
MODULE_ALIAS("dm-raid6");
MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
MODULE_LICENSE("GPL");