--- /dev/null
+/*
+ * 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 "md.h"
+#include "raid5.h"
+#include "dm.h"
+#include "bitmap.h"
+
+#define DM_MSG_PREFIX "raid"
+
+/*
+ * If the MD doesn't support MD_SYNC_STATE_FORCED yet, then
+ * make it so the flag doesn't set anything.
+ */
+#ifndef MD_SYNC_STATE_FORCED
+#define MD_SYNC_STATE_FORCED 0
+#endif
+
+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 mdk_rdev_s rdev;
+};
+
+/*
+ * Flags for rs->print_flags field.
+ */
+#define DMPF_DAEMON_SLEEP 0x1
+#define DMPF_MAX_WRITE_BEHIND 0x2
+#define DMPF_SYNC 0x4
+#define DMPF_NOSYNC 0x8
+#define DMPF_STRIPE_CACHE 0x10
+#define DMPF_MIN_RECOVERY_RATE 0x20
+#define DMPF_MAX_RECOVERY_RATE 0x40
+
+struct raid_set {
+ struct dm_target *ti;
+
+ uint64_t print_flags;
+
+ struct mddev_s 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[] = {
+ {"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 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;
+ sector_t sectors_per_dev;
+
+ if (raid_devs <= raid_type->parity_devs) {
+ ti->error = "Insufficient number of devices";
+ return ERR_PTR(-EINVAL);
+ }
+
+ sectors_per_dev = ti->len;
+ if (sector_div(sectors_per_dev, (raid_devs - raid_type->parity_devs))) {
+ ti->error = "Target length not divisible by number of data 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.dev_sectors = sectors_per_dev;
+ 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
+ */
+
+ 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].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
+ *
+ * This code parses those words.
+ */
+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], "-")) {
+ rs->ti->error = "Metadata devices not supported";
+ return -EINVAL;
+ }
+
+ 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;
+ }
+
+ 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;
+ }
+
+ 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;
+}
+
+/*
+ * Possible arguments are...
+ * RAID456:
+ * <chunk_size> [optional_args]
+ *
+ * Optional args:
+ * [[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
+ * [max_write_behind <sectors>] See '-write-behind=' (man mdadm)
+ * [stripe_cache <sectors>] Stripe cache size for higher RAIDs
+ */
+static int parse_raid_params(struct raid_set *rs, char **argv,
+ unsigned num_raid_params)
+{
+ unsigned i, rebuild_cnt = 0;
+ unsigned long value;
+ char *key;
+
+ /*
+ * First, parse the in-order required arguments
+ */
+ if ((strict_strtoul(argv[0], 10, &value) < 0) ||
+ !is_power_of_2(value) || (value < 8)) {
+ rs->ti->error = "Bad chunk size";
+ return -EINVAL;
+ }
+
+ rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
+ argv++;
+ num_raid_params--;
+
+ /*
+ * Second, parse the unordered optional arguments
+ */
+ for (i = 0; i < rs->md.raid_disks; i++)
+ set_bit(In_sync, &rs->dev[i].rdev.flags);
+
+ for (i = 0; i < num_raid_params; i++) {
+ if (!strcmp(argv[i], "nosync")) {
+ rs->md.recovery_cp = MaxSector;
+ rs->print_flags |= DMPF_NOSYNC;
+ rs->md.flags |= MD_SYNC_STATE_FORCED;
+ continue;
+ }
+ if (!strcmp(argv[i], "sync")) {
+ rs->md.recovery_cp = 0;
+ rs->print_flags |= DMPF_SYNC;
+ rs->md.flags |= MD_SYNC_STATE_FORCED;
+ 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++];
+ if (strict_strtoul(argv[i], 10, &value) < 0) {
+ rs->ti->error = "Bad numerical argument given in raid params";
+ return -EINVAL;
+ }
+
+ if (!strcmp(key, "rebuild")) {
+ if (++rebuild_cnt > rs->raid_type->parity_devs) {
+ rs->ti->error = "Too many rebuild drives given";
+ return -EINVAL;
+ }
+ 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;
+ } else if (!strcmp(key, "max_write_behind")) {
+ 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 (!strcmp(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 (!strcmp(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->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 (!strcmp(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 (!strcmp(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 {
+ DMERR("Unable to parse RAID parameter: %s", key);
+ rs->ti->error = "Unable to parse RAID parameters";
+ 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);
+
+ return md_raid5_congested(&rs->md, bits);
+}
+
+static void raid_unplug(struct dm_target_callbacks *cb)
+{
+ struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
+
+ md_raid5_unplug_device(rs->md.private);
+}
+
+/*
+ * Construct a RAID4/5/6 mapping:
+ * Args:
+ * <raid_type> <#raid_params> <raid_params> \
+ * <#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> }
+ *
+ * ** metadata devices are not supported yet, use '-' instead **
+ *
+ * <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;
+
+ INIT_WORK(&rs->md.event_work, do_table_event);
+ ti->split_io = rs->md.chunk_sectors;
+ ti->private = 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;
+ }
+
+ rs->callbacks.congested_fn = raid_is_congested;
+ rs->callbacks.unplug_fn = raid_unplug;
+ dm_table_add_target_callbacks(ti->table, &rs->callbacks);
+
+ return 0;
+
+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;
+ mddev_t *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,
+ 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;
+ sector_t sync;
+
+ switch (type) {
+ case STATUSTYPE_INFO:
+ DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks);
+
+ for (i = 0; i < rs->md.raid_disks; i++) {
+ if (test_bit(Faulty, &rs->dev[i].rdev.flags))
+ DMEMIT("D");
+ else if (test_bit(In_sync, &rs->dev[i].rdev.flags))
+ DMEMIT("A");
+ else
+ DMEMIT("a");
+ }
+
+ 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 = rs->md.resync_max_sectors;
+
+ 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->dev[i].data_dev &&
+ !test_bit(In_sync, &rs->dev[i].rdev.flags))
+ raid_param_cnt++; /* for rebuilds */
+
+ raid_param_cnt += (hweight64(rs->print_flags) * 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->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);
+
+ 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) {
+ raid5_conf_t *conf = rs->md.private;
+
+ /* convert from kiB to sectors */
+ DMEMIT(" stripe_cache %d",
+ conf ? conf->max_nr_stripes * 2 : 0);
+ }
+
+ DMEMIT(" %d", rs->md.raid_disks);
+ for (i = 0; i < rs->md.raid_disks; i++) {
+ DMEMIT(" -"); /* metadata device */
+
+ 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;
+ raid5_conf_t *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;
+
+ mddev_resume(&rs->md);
+}
+
+static struct target_type raid_target = {
+ .name = "raid",
+ .version = {1, 0, 0},
+ .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-raid4");
+MODULE_ALIAS("dm-raid5");
+MODULE_ALIAS("dm-raid6");
+MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
+MODULE_LICENSE("GPL");
projects / mirror_ubuntu-kernels.git / commitdiff