Commit b3996295 authored by Dmitry Fomichev's avatar Dmitry Fomichev Committed by Mike Snitzer
Browse files

dm zoned: support zone sizes smaller than 128MiB 



dm-zoned is observed to log failed kernel assertions and not work
correctly when operating against a device with a zone size smaller
than 128MiB (e.g. 32768 bits per 4K block). The reason is that the
bitmap size per zone is calculated as zero with such a small zone
size. Fix this problem and also make the code related to zone bitmap
management be able to handle per zone bitmaps smaller than a single
block.

A dm-zoned-tools patch is required to properly format dm-zoned devices
with zone sizes smaller than 128MiB.

Fixes: 3b1a94c8 ("dm zoned: drive-managed zoned block device target")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarDmitry Fomichev <dmitry.fomichev@wdc.com>
Reviewed-by: default avatarDamien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 43f3952a

drivers/md/dm-zoned-metadata.c

+14 −9
Original line number Diff line number Diff line
@@ -134,6 +134,7 @@ struct dmz_metadata { 


	sector_t		zone_bitmap_size;

	unsigned int		zone_nr_bitmap_blocks;

	unsigned int		zone_bits_per_mblk;



	unsigned int		nr_bitmap_blocks;

	unsigned int		nr_map_blocks;
@@ -1161,7 +1162,10 @@ static int dmz_init_zones(struct dmz_metadata *zmd) 


	/* Init */

	zmd->zone_bitmap_size = dev->zone_nr_blocks >> 3;

	zmd->zone_nr_bitmap_blocks = zmd->zone_bitmap_size >> DMZ_BLOCK_SHIFT;

	zmd->zone_nr_bitmap_blocks =

		max_t(sector_t, 1, zmd->zone_bitmap_size >> DMZ_BLOCK_SHIFT);

	zmd->zone_bits_per_mblk = min_t(sector_t, dev->zone_nr_blocks,

					DMZ_BLOCK_SIZE_BITS);



	/* Allocate zone array */

	zmd->zones = kcalloc(dev->nr_zones, sizeof(struct dm_zone), GFP_KERNEL);
@@ -1956,7 +1960,7 @@ int dmz_copy_valid_blocks(struct dmz_metadata *zmd, struct dm_zone *from_zone, 
		dmz_release_mblock(zmd, to_mblk);

		dmz_release_mblock(zmd, from_mblk);



		chunk_block += DMZ_BLOCK_SIZE_BITS;

		chunk_block += zmd->zone_bits_per_mblk;

	}



	to_zone->weight = from_zone->weight;
@@ -2017,7 +2021,7 @@ int dmz_validate_blocks(struct dmz_metadata *zmd, struct dm_zone *zone, 


		/* Set bits */

		bit = chunk_block & DMZ_BLOCK_MASK_BITS;

		nr_bits = min(nr_blocks, DMZ_BLOCK_SIZE_BITS - bit);

		nr_bits = min(nr_blocks, zmd->zone_bits_per_mblk - bit);



		count = dmz_set_bits((unsigned long *)mblk->data, bit, nr_bits);

		if (count) {
@@ -2096,7 +2100,7 @@ int dmz_invalidate_blocks(struct dmz_metadata *zmd, struct dm_zone *zone, 


		/* Clear bits */

		bit = chunk_block & DMZ_BLOCK_MASK_BITS;

		nr_bits = min(nr_blocks, DMZ_BLOCK_SIZE_BITS - bit);

		nr_bits = min(nr_blocks, zmd->zone_bits_per_mblk - bit);



		count = dmz_clear_bits((unsigned long *)mblk->data,

				       bit, nr_bits);
@@ -2156,6 +2160,7 @@ static int dmz_to_next_set_block(struct dmz_metadata *zmd, struct dm_zone *zone, 
{

	struct dmz_mblock *mblk;

	unsigned int bit, set_bit, nr_bits;

	unsigned int zone_bits = zmd->zone_bits_per_mblk;

	unsigned long *bitmap;

	int n = 0;
@@ -2170,15 +2175,15 @@ static int dmz_to_next_set_block(struct dmz_metadata *zmd, struct dm_zone *zone, 
		/* Get offset */

		bitmap = (unsigned long *) mblk->data;

		bit = chunk_block & DMZ_BLOCK_MASK_BITS;

		nr_bits = min(nr_blocks, DMZ_BLOCK_SIZE_BITS - bit);

		nr_bits = min(nr_blocks, zone_bits - bit);

		if (set)

			set_bit = find_next_bit(bitmap, DMZ_BLOCK_SIZE_BITS, bit);

			set_bit = find_next_bit(bitmap, zone_bits, bit);

		else

			set_bit = find_next_zero_bit(bitmap, DMZ_BLOCK_SIZE_BITS, bit);

			set_bit = find_next_zero_bit(bitmap, zone_bits, bit);

		dmz_release_mblock(zmd, mblk);



		n += set_bit - bit;

		if (set_bit < DMZ_BLOCK_SIZE_BITS)

		if (set_bit < zone_bits)

			break;



		nr_blocks -= nr_bits;
@@ -2281,7 +2286,7 @@ static void dmz_get_zone_weight(struct dmz_metadata *zmd, struct dm_zone *zone) 
		/* Count bits in this block */

		bitmap = mblk->data;

		bit = chunk_block & DMZ_BLOCK_MASK_BITS;

		nr_bits = min(nr_blocks, DMZ_BLOCK_SIZE_BITS - bit);

		nr_bits = min(nr_blocks, zmd->zone_bits_per_mblk - bit);

		n += dmz_count_bits(bitmap, bit, nr_bits);



		dmz_release_mblock(zmd, mblk);

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