diff options
| -rw-r--r-- | Documentation/device-mapper/dm-raid.txt | 12 | ||||
| -rw-r--r-- | drivers/md/Kconfig | 5 | ||||
| -rw-r--r-- | drivers/md/dm-raid.c | 419 |
3 files changed, 412 insertions, 24 deletions
diff --git a/Documentation/device-mapper/dm-raid.txt b/Documentation/device-mapper/dm-raid.txt index a7d1c4abc92..2a8c11331d2 100644 --- a/Documentation/device-mapper/dm-raid.txt +++ b/Documentation/device-mapper/dm-raid.txt @@ -11,6 +11,7 @@ The target is named "raid" and it accepts the following parameters: <#raid_devs> <metadata_dev0> <dev0> [.. <metadata_devN> <devN>] <raid_type>: + raid1 RAID1 mirroring raid4 RAID4 dedicated parity disk raid5_la RAID5 left asymmetric - rotating parity 0 with data continuation @@ -61,8 +62,7 @@ The target is named "raid" and it accepts the following parameters: <#raid_devs>: The number of devices composing the array. Each device consists of two entries. The first is the device containing the metadata (if any); the second is the one containing the - data. Currently, separate metadata devices are not supported and '-' - is required in place of the metadata device. + data. If a drive has failed or is missing at creation time, a '-' can be given for both the metadata and data drives for a given position. @@ -70,7 +70,7 @@ The target is named "raid" and it accepts the following parameters: Example tables -------------- -# RAID4 - 4 data drives, 1 parity +# RAID4 - 4 data drives, 1 parity (no metadata devices) # No metadata devices specified to hold superblock/bitmap info # Chunk size of 1MiB # (Lines separated for easy reading) @@ -79,13 +79,13 @@ Example tables raid4 1 2048 \ 5 - 8:17 - 8:33 - 8:49 - 8:65 - 8:81 -# RAID4 - 4 data drives, 1 parity (no metadata devices) +# RAID4 - 4 data drives, 1 parity (with metadata devices) # Chunk size of 1MiB, force RAID initialization, # min recovery rate at 20 kiB/sec/disk 0 1960893648 raid \ - raid4 4 2048 min_recovery_rate 20 sync\ - 5 - 8:17 - 8:33 - 8:49 - 8:65 - 8:81 + raid4 4 2048 sync min_recovery_rate 20 \ + 5 8:17 8:18 8:33 8:34 8:49 8:50 8:65 8:66 8:81 8:82 'dmsetup table' displays the table used to construct the mapping. The optional parameters are always printed in the order listed diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig index 8420129fc5e..f75a66e7d31 100644 --- a/drivers/md/Kconfig +++ b/drivers/md/Kconfig @@ -241,12 +241,13 @@ config DM_MIRROR needed for live data migration tools such as 'pvmove'. config DM_RAID - tristate "RAID 4/5/6 target (EXPERIMENTAL)" + tristate "RAID 1/4/5/6 target (EXPERIMENTAL)" depends on BLK_DEV_DM && EXPERIMENTAL + select MD_RAID1 select MD_RAID456 select BLK_DEV_MD ---help--- - A dm target that supports RAID4, RAID5 and RAID6 mappings + A dm target that supports RAID1, RAID4, RAID5 and RAID6 mappings A RAID-5 set of N drives with a capacity of C MB per drive provides the capacity of C * (N - 1) MB, and protects against a failure diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index 88143a0303d..69873806c50 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -16,12 +16,10 @@ #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. + * The following flags are used by dm-raid.c to set up the array state. + * They must be cleared before md_run is called. */ -#ifndef MD_SYNC_STATE_FORCED -#define MD_SYNC_STATE_FORCED 0 -#endif +#define FirstUse 10 /* rdev flag */ struct raid_dev { /* @@ -149,9 +147,16 @@ static void context_free(struct raid_set *rs) { int i; - for (i = 0; i < rs->md.raid_disks; 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); + if (rs->dev[i].rdev.sb_page) + put_page(rs->dev[i].rdev.sb_page); + rs->dev[i].rdev.sb_page = NULL; + rs->dev[i].rdev.sb_loaded = 0; if (rs->dev[i].data_dev) dm_put_device(rs->ti, rs->dev[i].data_dev); + } kfree(rs); } @@ -161,7 +166,16 @@ static void context_free(struct raid_set *rs) * <meta_dev>: meta device name or '-' if missing * <data_dev>: data device name or '-' if missing * - * This code parses those words. + * 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) { @@ -184,8 +198,16 @@ static int dev_parms(struct raid_set *rs, char **argv) rs->dev[i].rdev.mddev = &rs->md; if (strcmp(argv[0], "-")) { - rs->ti->error = "Metadata devices not supported"; - return -EINVAL; + 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], "-")) { @@ -195,6 +217,10 @@ static int dev_parms(struct raid_set *rs, char **argv) return -EINVAL; } + rs->ti->error = "No data device supplied with metadata device"; + if (rs->dev[i].meta_dev) + return -EINVAL; + continue; } @@ -206,6 +232,10 @@ static int dev_parms(struct raid_set *rs, char **argv) 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)) @@ -334,22 +364,39 @@ static int parse_raid_params(struct raid_set *rs, char **argv, num_raid_params--; /* - * Second, parse the unordered optional arguments + * 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++) + 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; - rs->md.flags |= MD_SYNC_STATE_FORCED; continue; } if (!strcasecmp(argv[i], "sync")) { rs->md.recovery_cp = 0; rs->print_flags |= DMPF_SYNC; - rs->md.flags |= MD_SYNC_STATE_FORCED; continue; } @@ -482,13 +529,344 @@ static int raid_is_congested(struct dm_target_callbacks *cb, int 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(mdk_rdev_t *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 device superblock"); + return -EINVAL; + } + + rdev->sb_loaded = 1; + + return 0; +} + +static void super_sync(mddev_t *mddev, mdk_rdev_t *rdev) +{ + mdk_rdev_t *r, *t; + uint64_t failed_devices; + struct dm_raid_superblock *sb; + + sb = page_address(rdev->sb_page); + failed_devices = le64_to_cpu(sb->failed_devices); + + rdev_for_each(r, t, mddev) + if ((r->raid_disk >= 0) && test_bit(Faulty, &r->flags)) + failed_devices |= (1ULL << r->raid_disk); + + 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(mdk_rdev_t *rdev, mdk_rdev_t *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); + if (sb->magic != cpu_to_le32(DM_RAID_MAGIC)) { + 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(mddev_t *mddev, mdk_rdev_t *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; + mdk_rdev_t *r, *t; + struct dm_raid_superblock *sb2; + + sb = page_address(rdev->sb_page); + events_sb = le64_to_cpu(sb->events); + failed_devices = le64_to_cpu(sb->failed_devices); + + /* + * Initialise to 1 if this is a new superblock. + */ + mddev->events = events_sb ? : 1; + + /* + * Reshaping is not currently allowed + */ + if ((le32_to_cpu(sb->level) != mddev->level) || + (le32_to_cpu(sb->layout) != mddev->layout) || + (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors)) { + DMERR("Reshaping arrays not yet supported."); + return -EINVAL; + } + + /* We can only change the number of devices in RAID1 right now */ + if ((rs->raid_type->level != 1) && + (le32_to_cpu(sb->num_devices) != mddev->raid_disks)) { + DMERR("Reshaping arrays not yet supported."); + return -EINVAL; + } + + if (!(rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC))) + mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset); + + /* + * During load, we set FirstUse if a new superblock was written. + * There are two reasons we might not have a superblock: + * 1) The array is brand new - in which case, all of the + * devices must have their In_sync bit set. Also, + * recovery_cp must be 0, unless forced. + * 2) This is a new device being added to an old array + * and the new device needs to be rebuilt - in which + * case the In_sync bit will /not/ be set and + * recovery_cp must be MaxSector. + */ + rdev_for_each(r, t, mddev) { + if (!test_bit(In_sync, &r->flags)) { + if (!test_bit(FirstUse, &r->flags)) + DMERR("Superblock area of " + "rebuild device %d should have been " + "cleared.", r->raid_disk); + set_bit(FirstUse, &r->flags); + 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, t, 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(mddev_t *mddev, mdk_rdev_t *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; + mdk_rdev_t *rdev, *freshest, *tmp; + mddev_t *mddev = &rs->md; + + freshest = NULL; + rdev_for_each(rdev, tmp, mddev) { + if (!rdev->meta_bdev) + continue; + + ret = super_load(rdev, freshest); + + switch (ret) { + case 1: + freshest = rdev; + break; + case 0: + break; + default: + ti->error = "Failed to load superblock"; + return ret; + } + } + + if (!freshest) + return 0; + + /* + * Validation of the freshest device provides the source of + * validation for the remaining devices. + */ + ti->error = "Unable to assemble array: Invalid superblocks"; + if (super_validate(mddev, freshest)) + return -EINVAL; + + rdev_for_each(rdev, tmp, 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> } * - * ** metadata devices are not supported yet, use '-' instead ** - * * <raid_params> varies by <raid_type>. See 'parse_raid_params' for * details on possible <raid_params>. */ @@ -556,6 +934,11 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **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; @@ -698,7 +1081,10 @@ static int raid_status(struct dm_target *ti, status_type_t type, DMEMIT(" %d", rs->md.raid_disks); for (i = 0; i < rs->md.raid_disks; i++) { - DMEMIT(" -"); /* metadata device */ + 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); @@ -755,6 +1141,7 @@ static void raid_resume(struct dm_target *ti) { struct raid_set *rs = ti->private; + bitmap_load(&rs->md); mddev_resume(&rs->md); } |