[dm-devel] [PATCH] dm-zoned: support zone sizes smaller than 128MiB
Dmitry Fomichev
dmitry.fomichev at wdc.com
Tue Dec 24 01:05:46 UTC 2019
dm-zoned is observed to log failed kernel assertions and not to work
correctly when operating against a device with a zone size smaller
than 128MiB (4K block size times 32768 bits per 4K block). The reason
is that the bitmap size per zone is calculated as zero with such a
small zone size. This patch fixes this problem and also makes 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 and this patch is being posted
separately.
Fixes: 3b1a94c88b79 ("dm zoned: drive-managed zoned block device target")
Cc: stable at vger.kernel.org
Signed-off-by: Dmitry Fomichev <dmitry.fomichev at wdc.com>
---
drivers/md/dm-zoned-metadata.c | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)
diff --git a/drivers/md/dm-zoned-metadata.c b/drivers/md/dm-zoned-metadata.c
index 069e4675da6b..91512eb40458 100644
--- a/drivers/md/dm-zoned-metadata.c
+++ b/drivers/md/dm-zoned-metadata.c
@@ -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;
@@ -1153,7 +1154,10 @@ 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);
@@ -1947,7 +1951,7 @@ 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;
@@ -2008,7 +2012,7 @@ 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) {
@@ -2087,7 +2091,7 @@ 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);
@@ -2147,6 +2151,7 @@ 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;
@@ -2161,15 +2166,15 @@ 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;
@@ -2272,7 +2277,7 @@ 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);
--
2.21.0
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