diff options
| -rw-r--r-- | Documentation/device-mapper/dm-raid.txt | 4 | ||||
| -rw-r--r-- | drivers/md/dm-raid.c | 82 |
2 files changed, 83 insertions, 3 deletions
diff --git a/Documentation/device-mapper/dm-raid.txt b/Documentation/device-mapper/dm-raid.txt index 4f9dd3cecc11..be4419a30781 100644 --- a/Documentation/device-mapper/dm-raid.txt +++ b/Documentation/device-mapper/dm-raid.txt @@ -52,6 +52,10 @@ The target is named "raid" and it accepts the following parameters: [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization [max_write_behind <sectors>] See '-write-behind=' (man mdadm) [stripe_cache <sectors>] Stripe cache size (higher RAIDs only) + [region_size <sectors>] + The region_size multiplied by the number of regions is the + logical size of the array. The bitmap records the device + synchronisation state for each region. <#raid_devs>: The number of devices composing the array. Each device consists of two entries. The first is the device diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index d4e95b2e39f6..a8a1915a450d 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -52,7 +52,7 @@ struct raid_dev { #define DMPF_MAX_RECOVERY_RATE 0x20 #define DMPF_MAX_WRITE_BEHIND 0x40 #define DMPF_STRIPE_CACHE 0x80 - +#define DMPF_REGION_SIZE 0X100 struct raid_set { struct dm_target *ti; @@ -237,6 +237,67 @@ static int dev_parms(struct raid_set *rs, char **argv) } /* + * validate_region_size + * @rs + * @region_size: region size in sectors. If 0, pick a size (4MiB default). + * + * Set rs->md.bitmap_info.chunksize (which really refers to 'region size'). + * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap. + * + * Returns: 0 on success, -EINVAL on failure. + */ +static int validate_region_size(struct raid_set *rs, unsigned long region_size) +{ + unsigned long min_region_size = rs->ti->len / (1 << 21); + + if (!region_size) { + /* + * Choose a reasonable default. All figures in sectors. + */ + if (min_region_size > (1 << 13)) { + DMINFO("Choosing default region size of %lu sectors", + region_size); + region_size = min_region_size; + } else { + DMINFO("Choosing default region size of 4MiB"); + region_size = 1 << 13; /* sectors */ + } + } else { + /* + * Validate user-supplied value. + */ + if (region_size > rs->ti->len) { + rs->ti->error = "Supplied region size is too large"; + return -EINVAL; + } + + if (region_size < min_region_size) { + DMERR("Supplied region_size (%lu sectors) below minimum (%lu)", + region_size, min_region_size); + rs->ti->error = "Supplied region size is too small"; + return -EINVAL; + } + + if (!is_power_of_2(region_size)) { + rs->ti->error = "Region size is not a power of 2"; + return -EINVAL; + } + + if (region_size < rs->md.chunk_sectors) { + rs->ti->error = "Region size is smaller than the chunk size"; + return -EINVAL; + } + } + + /* + * Convert sectors to bytes. + */ + rs->md.bitmap_info.chunksize = (region_size << 9); + + return 0; +} + +/* * Possible arguments are... * RAID456: * <chunk_size> [optional_args] @@ -249,12 +310,13 @@ static int dev_parms(struct raid_set *rs, char **argv) * [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 + * [region_size <sectors>] Defines granularity of bitmap */ static int parse_raid_params(struct raid_set *rs, char **argv, unsigned num_raid_params) { unsigned i, rebuild_cnt = 0; - unsigned long value; + unsigned long value, region_size = 0; char *key; /* @@ -365,6 +427,9 @@ static int parse_raid_params(struct raid_set *rs, char **argv, 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 { DMERR("Unable to parse RAID parameter: %s", key); rs->ti->error = "Unable to parse RAID parameters"; @@ -372,6 +437,14 @@ static int parse_raid_params(struct raid_set *rs, char **argv, } } + if (validate_region_size(rs, region_size)) + return -EINVAL; + + if (rs->md.chunk_sectors) + rs->ti->split_io = rs->md.chunk_sectors; + else + rs->ti->split_io = region_size; + /* Assume there are no metadata devices until the drives are parsed */ rs->md.persistent = 0; rs->md.external = 1; @@ -469,7 +542,6 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv) 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); @@ -596,6 +668,10 @@ static int raid_status(struct dm_target *ti, status_type_t type, conf ? conf->max_nr_stripes * 2 : 0); } + if (rs->print_flags & DMPF_REGION_SIZE) + DMEMIT(" region_size %lu", + rs->md.bitmap_info.chunksize >> 9); + DMEMIT(" %d", rs->md.raid_disks); for (i = 0; i < rs->md.raid_disks; i++) { DMEMIT(" -"); /* metadata device */ |