dm raid: add region_size parameter (c1084561) · Commits · e / devices / android_kernel_teracube_2e

Documentation/device-mapper/dm-raid.txt

+4 −0

Original line number	Diff line number	Diff line
		@@ -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

drivers/md/dm-raid.c

+79 −3

Original line number	Diff line number	Diff line
		@@ -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;

		@@ -236,6 +236,67 @@ static int dev_parms(struct raid_set rs, char *argv)
		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)) {
		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:
		@@ -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 */