--- /dev/null
+/*
+ * Copyright (C) 2010-2011 Neil Brown
+ * Copyright (C) 2010-2014 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"
+
+static bool devices_handle_discard_safely = false;
+
+/*
+ * 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 char *raid10_md_layout_to_format(int layout)
+{
+ /*
+ * Bit 16 and 17 stand for "offset" and "use_far_sets"
+ * Refer to MD's raid10.c for details
+ */
+ if ((layout & 0x10000) && (layout & 0x20000))
+ return "offset";
+
+ if ((layout & 0xFF) > 1)
+ return "near";
+
+ return "far";
+}
+
+static unsigned raid10_md_layout_to_copies(int layout)
+{
+ if ((layout & 0xFF) > 1)
+ return layout & 0xFF;
+ return (layout >> 8) & 0xFF;
+}
+
+static int raid10_format_to_md_layout(char *format, unsigned copies)
+{
+ unsigned n = 1, f = 1;
+
+ if (!strcmp("near", format))
+ n = copies;
+ else
+ f = copies;
+
+ if (!strcmp("offset", format))
+ return 0x30000 | (f << 8) | n;
+
+ if (!strcmp("far", format))
+ return 0x20000 | (f << 8) | n;
+
+ return (f << 8) | n;
+}
+
+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)) {
+ /* If not a power of 2, make it the next power of 2 */
+ if (min_region_size & (min_region_size - 1))
+ region_size = 1 << fls(region_size);
+ DMINFO("Choosing default region size of %lu sectors",
+ 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_raid_redundancy
+ * @rs
+ *
+ * Determine if there are enough devices in the array that haven't
+ * failed (or are being rebuilt) to form a usable array.
+ *
+ * Returns: 0 on success, -EINVAL on failure.
+ */
+static int validate_raid_redundancy(struct raid_set *rs)
+{
+ unsigned i, rebuild_cnt = 0;
+ unsigned rebuilds_per_group = 0, copies, d;
+ unsigned group_size, last_group_start;
+
+ for (i = 0; i < rs->md.raid_disks; i++)
+ if (!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
+ !rs->dev[i].rdev.sb_page)
+ 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).
+ *
+ * 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
+ */
+ if (!strcmp("near", raid10_md_layout_to_format(rs->md.layout))) {
+ for (i = 0; i < rs->md.raid_disks * copies; i++) {
+ if (!(i % copies))
+ rebuilds_per_group = 0;
+ d = i % rs->md.raid_disks;
+ if ((!rs->dev[d].rdev.sb_page ||
+ !test_bit(In_sync, &rs->dev[d].rdev.flags)) &&
+ (++rebuilds_per_group >= copies))
+ goto too_many;
+ }
+ break;
+ }
+
+ /*
+ * When checking "far" and "offset" formats, we need to ensure
+ * that the device that holds its copy is not also dead or
+ * being rebuilt. (Note that "far" and "offset" formats only
+ * support two copies right now. These formats also only ever
+ * use the 'use_far_sets' variant.)
+ *
+ * This check is somewhat complicated by the need to account
+ * for arrays that are not a multiple of (far) copies. This
+ * results in the need to treat the last (potentially larger)
+ * set differently.
+ */
+ group_size = (rs->md.raid_disks / copies);
+ last_group_start = (rs->md.raid_disks / group_size) - 1;
+ last_group_start *= group_size;
+ for (i = 0; i < rs->md.raid_disks; i++) {
+ if (!(i % copies) && !(i > last_group_start))
+ rebuilds_per_group = 0;
+ if ((!rs->dev[i].rdev.sb_page ||
+ !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
+ (++rebuilds_per_group >= copies))
+ goto too_many;
+ }
+ break;
+ default:
+ if (rebuild_cnt)
+ return -EINVAL;
+ }
+
+ return 0;
+
+too_many:
+ 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
+ * [devices_handle_discard_safely] Allow discards on RAID4/5/6; useful if RAID
+ * member device(s) properly support TRIM/UNMAP
+ * [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|far|offset>] 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 ((kstrtoul(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]) &&
+ strcmp("far", argv[i]) &&
+ strcmp("offset", argv[i])) {
+ rs->ti->error = "Invalid 'raid10_format' value given";
+ return -EINVAL;
+ }
+ raid10_format = argv[i];
+ rs->print_flags |= DMPF_RAID10_FORMAT;
+ continue;
+ }
+
+ if (kstrtoul(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;
+ }
+
+ /*
+ * If the format is not "near", we only support
+ * two copies at the moment.
+ */
+ if (strcmp("near", raid10_format) && (raid10_copies > 2)) {
+ rs->ti->error = "Too many copies for given RAID10 format.";
+ 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;
+
+ /* 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);
+
+ return mddev_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;
+
+ /* Remainder of a logical block is zero-filled when writing (see super_sync()). */
+} __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 + 1, 0, rdev->sb_size - 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 = bdev_logical_block_size(rdev->meta_bdev);
+ if (rdev->sb_size < sizeof(*sb) || rdev->sb_size > PAGE_SIZE) {
+ DMERR("superblock size of a logical block is no longer valid");
+ return -EINVAL;
+ }
+
+ 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) {
+ DMERR("Reshaping arrays not yet supported. (RAID level change)");
+ return -EINVAL;
+ }
+ if (le32_to_cpu(sb->layout) != mddev->layout) {
+ DMERR("Reshaping arrays not yet supported. (RAID layout change)");
+ DMERR(" 0x%X vs 0x%X", le32_to_cpu(sb->layout), mddev->layout);
+ DMERR(" Old layout: %s w/ %d copies",
+ raid10_md_layout_to_format(le32_to_cpu(sb->layout)),
+ raid10_md_layout_to_copies(le32_to_cpu(sb->layout)));
+ DMERR(" New layout: %s w/ %d copies",
+ raid10_md_layout_to_format(mddev->layout),
+ raid10_md_layout_to_copies(mddev->layout));
+ return -EINVAL;
+ }
+ if (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors) {
+ DMERR("Reshaping arrays not yet supported. (stripe sectors change)");
+ 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. (device count change)");
+ 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;
+ struct raid_dev *dev;
+ struct md_rdev *rdev, *tmp, *freshest;
+ struct mddev *mddev = &rs->md;
+
+ 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 (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);
+ }
+ }
+
+ if (!freshest)
+ return 0;
+
+ if (validate_raid_redundancy(rs)) {
+ rs->ti->error = "Insufficient redundancy to activate array";
+ return -EINVAL;
+ }
+
+ /*
+ * 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;
+}
+
+/*
+ * Enable/disable discard support on RAID set depending on
+ * RAID level and discard properties of underlying RAID members.
+ */
+static void configure_discard_support(struct dm_target *ti, struct raid_set *rs)
+{
+ int i;
+ bool raid456;
+
+ /* Assume discards not supported until after checks below. */
+ ti->discards_supported = false;
+
+ /* RAID level 4,5,6 require discard_zeroes_data for data integrity! */
+ raid456 = (rs->md.level == 4 || rs->md.level == 5 || rs->md.level == 6);
+
+ for (i = 0; i < rs->md.raid_disks; i++) {
+ struct request_queue *q;
+
+ if (!rs->dev[i].rdev.bdev)
+ continue;
+
+ q = bdev_get_queue(rs->dev[i].rdev.bdev);
+ if (!q || !blk_queue_discard(q))
+ return;
+
+ if (raid456) {
+ if (!q->limits.discard_zeroes_data)
+ return;
+ if (!devices_handle_discard_safely) {
+ DMERR("raid456 discard support disabled due to discard_zeroes_data uncertainty.");
+ DMERR("Set dm-raid.devices_handle_discard_safely=Y to override.");
+ return;
+ }
+ }
+ }
+
+ /* All RAID members properly support discards */
+ ti->discards_supported = true;
+
+ /*
+ * RAID1 and RAID10 personalities require bio splitting,
+ * RAID0/4/5/6 don't and process large discard bios properly.
+ */
+ ti->split_discard_bios = !!(rs->md.level == 1 || rs->md.level == 10);
+ ti->num_discard_bios = 1;
+}
+
+/*
+ * 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 (kstrtoul(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 >= argc) {
+ ti->error = "Arguments do not agree with counts given";
+ return -EINVAL;
+ }
+
+ if ((kstrtoul(argv[num_raid_params], 10, &num_raid_devs) < 0) ||
+ (num_raid_devs >= INT_MAX)) {
+ ti->error = "Cannot understand number of raid devices";
+ return -EINVAL;
+ }
+
+ argc -= num_raid_params + 1; /* +1: we already have num_raid_devs */
+ if (argc != (num_raid_devs * 2)) {
+ ti->error = "Supplied RAID devices does not match the count given";
+ 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;
+
+ argv += num_raid_params + 1;
+
+ 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_bios = 1;
+
+ /*
+ * Disable/enable discard support on RAID set.
+ */
+ configure_discard_support(ti, rs);
+
+ 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)
+{
+ struct raid_set *rs = ti->private;
+ struct mddev *mddev = &rs->md;
+
+ mddev->pers->make_request(mddev, bio);
+
+ return DM_MAPIO_SUBMITTED;
+}
+
+static const char *decipher_sync_action(struct mddev *mddev)
+{
+ if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
+ return "frozen";
+
+ if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
+ (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
+ if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
+ return "reshape";
+
+ if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
+ if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
+ return "resync";
+ else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
+ return "check";
+ return "repair";
+ }
+
+ if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
+ return "recover";
+ }
+
+ return "idle";
+}
+
+static void 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) {
+ /*
+ * Sync complete.
+ */
+ array_in_sync = 1;
+ sync = rs->md.resync_max_sectors;
+ } else if (test_bit(MD_RECOVERY_REQUESTED, &rs->md.recovery)) {
+ /*
+ * If "check" or "repair" is occurring, the array has
+ * undergone and initial sync and the health characters
+ * should not be 'a' anymore.
+ */
+ array_in_sync = 1;
+ } 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);
+
+ /*
+ * Sync action:
+ * See Documentation/device-mapper/dm-raid.c for
+ * information on each of these states.
+ */
+ DMEMIT(" %s", decipher_sync_action(&rs->md));
+
+ /*
+ * resync_mismatches/mismatch_cnt
+ * This field shows the number of discrepancies found when
+ * performing a "check" of the array.
+ */
+ DMEMIT(" %llu",
+ (strcmp(rs->md.last_sync_action, "check")) ? 0 :
+ (unsigned long long)
+ atomic64_read(&rs->md.resync_mismatches));
+ 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 %s",
+ raid10_md_layout_to_format(rs->md.layout));
+
+ 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(" -");
+ }
+ }
+}
+
+static int raid_message(struct dm_target *ti, unsigned argc, char **argv)
+{
+ struct raid_set *rs = ti->private;
+ struct mddev *mddev = &rs->md;
+
+ if (!strcasecmp(argv[0], "reshape")) {
+ DMERR("Reshape not supported.");
+ return -EINVAL;
+ }
+
+ if (!mddev->pers || !mddev->pers->sync_request)
+ return -EINVAL;
+
+ if (!strcasecmp(argv[0], "frozen"))
+ set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+ else
+ clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+
+ if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) {
+ if (mddev->sync_thread) {
+ set_bit(MD_RECOVERY_INTR, &mddev->recovery);
+ md_reap_sync_thread(mddev);
+ }
+ } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
+ test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
+ return -EBUSY;
+ else if (!strcasecmp(argv[0], "resync"))
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ else if (!strcasecmp(argv[0], "recover")) {
+ set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ } else {
+ if (!strcasecmp(argv[0], "check"))
+ set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
+ else if (!!strcasecmp(argv[0], "repair"))
+ return -EINVAL;
+ set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
+ set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
+ }
+ if (mddev->ro == 2) {
+ /* A write to sync_action is enough to justify
+ * canceling read-auto mode
+ */
+ mddev->ro = 0;
+ if (!mddev->suspended)
+ md_wakeup_thread(mddev->sync_thread);
+ }
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ if (!mddev->suspended)
+ md_wakeup_thread(mddev->thread);
+
+ 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 attempt_restore_of_faulty_devices(struct raid_set *rs)
+{
+ int i;
+ uint64_t failed_devices, cleared_failed_devices = 0;
+ unsigned long flags;
+ struct dm_raid_superblock *sb;
+ struct md_rdev *r;
+
+ for (i = 0; i < rs->md.raid_disks; i++) {
+ r = &rs->dev[i].rdev;
+ if (test_bit(Faulty, &r->flags) && r->sb_page &&
+ sync_page_io(r, 0, r->sb_size, r->sb_page, READ, 1)) {
+ DMINFO("Faulty %s device #%d has readable super block."
+ " Attempting to revive it.",
+ rs->raid_type->name, i);
+
+ /*
+ * Faulty bit may be set, but sometimes the array can
+ * be suspended before the personalities can respond
+ * by removing the device from the array (i.e. calling
+ * 'hot_remove_disk'). If they haven't yet removed
+ * the failed device, its 'raid_disk' number will be
+ * '>= 0' - meaning we must call this function
+ * ourselves.
+ */
+ if ((r->raid_disk >= 0) &&
+ (r->mddev->pers->hot_remove_disk(r->mddev, r) != 0))
+ /* Failed to revive this device, try next */
+ continue;
+
+ r->raid_disk = i;
+ r->saved_raid_disk = i;
+ flags = r->flags;
+ clear_bit(Faulty, &r->flags);
+ clear_bit(WriteErrorSeen, &r->flags);
+ clear_bit(In_sync, &r->flags);
+ if (r->mddev->pers->hot_add_disk(r->mddev, r)) {
+ r->raid_disk = -1;
+ r->saved_raid_disk = -1;
+ r->flags = flags;
+ } else {
+ r->recovery_offset = 0;
+ cleared_failed_devices |= 1 << i;
+ }
+ }
+ }
+ if (cleared_failed_devices) {
+ rdev_for_each(r, &rs->md) {
+ sb = page_address(r->sb_page);
+ failed_devices = le64_to_cpu(sb->failed_devices);
+ failed_devices &= ~cleared_failed_devices;
+ sb->failed_devices = cpu_to_le64(failed_devices);
+ }
+ }
+}
+
+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;
+ } else {
+ /*
+ * A secondary resume while the device is active.
+ * Take this opportunity to check whether any failed
+ * devices are reachable again.
+ */
+ attempt_restore_of_faulty_devices(rs);
+ }
+
+ clear_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
+ mddev_resume(&rs->md);
+}
+
+static struct target_type raid_target = {
+ .name = "raid",
+ .version = {1, 6, 0},
+ .module = THIS_MODULE,
+ .ctr = raid_ctr,
+ .dtr = raid_dtr,
+ .map = raid_map,
+ .status = raid_status,
+ .message = raid_message,
+ .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)
+{
+ DMINFO("Loading target version %u.%u.%u",
+ raid_target.version[0],
+ raid_target.version[1],
+ raid_target.version[2]);
+ 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_param(devices_handle_discard_safely, bool, 0644);
+MODULE_PARM_DESC(devices_handle_discard_safely,
+ "Set to Y if all devices in each array reliably return zeroes on reads from discarded regions");
+
+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");
Code Review / kvmfornfv.git / blobdiff