diff options
Diffstat (limited to 'drivers/md/dm-raid.c')
| -rw-r--r-- | drivers/md/dm-raid.c | 1693 |
1 files changed, 1693 insertions, 0 deletions
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c new file mode 100644 index 00000000000..4880b69e2e9 --- /dev/null +++ b/drivers/md/dm-raid.c @@ -0,0 +1,1693 @@ +/* + * 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 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 + * [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); + + 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) { + 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; +} + +/* + * 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 + 1 > 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; + } + + 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_bios = 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) +{ + 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, 5, 2}, + .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_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"); |