[PATCH 0/9] md: Make raid0 use sector-based quantities

[PATCH 0/9] md: Make raid0 use sector-based quantities

[Andre Noll]

[try #2, this time with the missing patch included]

This series of patches against Neil's for-next branch converts the
internal representations of block-based quantities in the raid0 code
to sector-based quantities.

There's also one trivial patch in this series, #7, which adds
KERN_INFO/KERN_ERR to a couple of printk's.

checkpatch.pl is happy with all nine patches, and the patched kernel
passes the raid0 tests of mdadm's test suite on my i386 UP box.

Please review.
Andre

[PATCH 1/9] md: raid0_make_request(): Replace chunksize_bits by chunksect_bits.

[Andre Noll]

As ffz(~(2 * x)) = ffz(~x) + 1, we have

	chunksect_bits = chunksize_bits + 1.

Fixup all users accordingly.
---
 drivers/md/raid0.c |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 8ac6488..62a193c 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -387,7 +387,7 @@ static int raid0_stop (mddev_t *mddev)
 static int raid0_make_request (struct request_queue *q, struct bio *bio)
 {
 	mddev_t *mddev = q->queuedata;
-	unsigned int sect_in_chunk, chunksize_bits,  chunk_size, chunk_sects;
+	unsigned int sect_in_chunk, chunksect_bits, chunk_size, chunk_sects;
 	raid0_conf_t *conf = mddev_to_conf(mddev);
 	struct strip_zone *zone;
 	mdk_rdev_t *tmp_dev;
@@ -409,7 +409,7 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
 
 	chunk_size = mddev->chunk_size >> 10;
 	chunk_sects = mddev->chunk_size >> 9;
-	chunksize_bits = ffz(~chunk_size);
+	chunksect_bits = ffz(~chunk_sects);
 	block = bio->bi_sector >> 1;
 	
 
@@ -446,15 +446,15 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
 
 
 	{
-		sector_t x =  (block - zone->zone_offset) >> chunksize_bits;
+		sector_t x =  (block - zone->zone_offset) >> (chunksect_bits - 1);
 
 		sector_div(x, zone->nb_dev);
 		chunk = x;
 
-		x = block >> chunksize_bits;
+		x = block >> (chunksect_bits - 1);
 		tmp_dev = zone->dev[sector_div(x, zone->nb_dev)];
 	}
-	rsect = (((chunk << chunksize_bits) + zone->dev_offset)<<1)
+	rsect = (((chunk << (chunksect_bits - 1)) + zone->dev_offset)<<1)
 		+ sect_in_chunk;
  
 	bio->bi_bdev = tmp_dev->bdev;
-- 
1.5.3.8

[PATCH 2/9] md: raid0_make_request(): Remove local variable chunk_size.

[Andre Noll]

We might as well use chunk_sects instead.
---
 drivers/md/raid0.c |    7 +++----
 1 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 62a193c..d843849 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -387,7 +387,7 @@ static int raid0_stop (mddev_t *mddev)
 static int raid0_make_request (struct request_queue *q, struct bio *bio)
 {
 	mddev_t *mddev = q->queuedata;
-	unsigned int sect_in_chunk, chunksect_bits, chunk_size, chunk_sects;
+	unsigned int sect_in_chunk, chunksect_bits, chunk_sects;
 	raid0_conf_t *conf = mddev_to_conf(mddev);
 	struct strip_zone *zone;
 	mdk_rdev_t *tmp_dev;
@@ -407,7 +407,6 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
 		      bio_sectors(bio));
 	part_stat_unlock();
 
-	chunk_size = mddev->chunk_size >> 10;
 	chunk_sects = mddev->chunk_size >> 9;
 	chunksect_bits = ffz(~chunk_sects);
 	block = bio->bi_sector >> 1;
@@ -442,7 +441,7 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
 	while (block >= (zone->zone_offset + zone->size)) 
 		zone++;
     
-	sect_in_chunk = bio->bi_sector & ((chunk_size<<1) -1);
+	sect_in_chunk = bio->bi_sector & (chunk_sects - 1);
 
 
 	{
@@ -467,7 +466,7 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
 
 bad_map:
 	printk("raid0_make_request bug: can't convert block across chunks"
-		" or bigger than %dk %llu %d\n", chunk_size, 
+		" or bigger than %dk %llu %d\n", chunk_sects / 2,
 		(unsigned long long)bio->bi_sector, bio->bi_size >> 10);
 
 	bio_io_error(bio);
-- 
1.5.3.8

[PATCH 3/9] md: raid0_make_request(): Replace local variable block by sector.

[Andre Noll]

This change already simplifies the code a bit.
---
 drivers/md/raid0.c |   13 ++++++-------
 1 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index d843849..fd65d88 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -392,7 +392,7 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
 	struct strip_zone *zone;
 	mdk_rdev_t *tmp_dev;
 	sector_t chunk;
-	sector_t block, rsect;
+	sector_t sector, rsect;
 	const int rw = bio_data_dir(bio);
 	int cpu;
 
@@ -409,8 +409,7 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
 
 	chunk_sects = mddev->chunk_size >> 9;
 	chunksect_bits = ffz(~chunk_sects);
-	block = bio->bi_sector >> 1;
-	
+	sector = bio->bi_sector;
 
 	if (unlikely(chunk_sects < (bio->bi_sector & (chunk_sects - 1)) + (bio->bi_size >> 9))) {
 		struct bio_pair *bp;
@@ -433,24 +432,24 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
  
 
 	{
-		sector_t x = block >> conf->preshift;
+		sector_t x = sector >> (conf->preshift + 1);
 		sector_div(x, (u32)conf->hash_spacing);
 		zone = conf->hash_table[x];
 	}
  
-	while (block >= (zone->zone_offset + zone->size)) 
+	while (sector / 2 >= (zone->zone_offset + zone->size))
 		zone++;
     
 	sect_in_chunk = bio->bi_sector & (chunk_sects - 1);
 
 
 	{
-		sector_t x =  (block - zone->zone_offset) >> (chunksect_bits - 1);
+		sector_t x = (sector - zone->zone_offset * 2) >> chunksect_bits;
 
 		sector_div(x, zone->nb_dev);
 		chunk = x;
 
-		x = block >> (chunksect_bits - 1);
+		x = sector >> chunksect_bits;
 		tmp_dev = zone->dev[sector_div(x, zone->nb_dev)];
 	}
 	rsect = (((chunk << (chunksect_bits - 1)) + zone->dev_offset)<<1)
-- 
1.5.3.8

[PATCH 4/9] md: raid0: Represent device offset in sectors.

[Andre Noll]

Rename zone->dev_offset to zone->dev_start to make sure all users
have been converted.
---
 drivers/md/raid0.c         |    9 ++++-----
 include/linux/raid/raid0.h |    2 +-
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index fd65d88..b860536 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -167,7 +167,7 @@ static int create_strip_zones (mddev_t *mddev)
 		zone->dev = conf->strip_zone[i-1].dev + mddev->raid_disks;
 
 		printk("raid0: zone %d\n", i);
-		zone->dev_offset = current_offset;
+		zone->dev_start = current_offset * 2;
 		smallest = NULL;
 		c = 0;
 
@@ -452,8 +452,7 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
 		x = sector >> chunksect_bits;
 		tmp_dev = zone->dev[sector_div(x, zone->nb_dev)];
 	}
-	rsect = (((chunk << (chunksect_bits - 1)) + zone->dev_offset)<<1)
-		+ sect_in_chunk;
+	rsect = (chunk << chunksect_bits) + zone->dev_start + sect_in_chunk;
  
 	bio->bi_bdev = tmp_dev->bdev;
 	bio->bi_sector = rsect + tmp_dev->data_offset;
@@ -490,9 +489,9 @@ static void raid0_status (struct seq_file *seq, mddev_t *mddev)
 			seq_printf(seq, "%s/", bdevname(
 				conf->strip_zone[j].dev[k]->bdev,b));
 
-		seq_printf(seq, "] zo=%d do=%d s=%d\n",
+		seq_printf(seq, "] zo=%d ds=%d s=%d\n",
 				conf->strip_zone[j].zone_offset,
-				conf->strip_zone[j].dev_offset,
+				conf->strip_zone[j].dev_start,
 				conf->strip_zone[j].size);
 	}
 #endif
diff --git a/include/linux/raid/raid0.h b/include/linux/raid/raid0.h
index 1b2dda0..61c3d29 100644
--- a/include/linux/raid/raid0.h
+++ b/include/linux/raid/raid0.h
@@ -6,7 +6,7 @@
 struct strip_zone
 {
 	sector_t zone_offset;	/* Zone offset in md_dev */
-	sector_t dev_offset;	/* Zone offset in real dev */
+	sector_t dev_start;	/* Zone offset in real dev (in sectors) */
 	sector_t size;		/* Zone size */
 	int nb_dev;		/* # of devices attached to the zone */
 	mdk_rdev_t **dev;	/* Devices attached to the zone */
-- 
1.5.3.8

[PATCH 5/9] md: raid0: Represent zone->zone_offset in sectors.

[Andre Noll]

For the same reason as in the previous patch, rename it from zone_offset
to zone_start.
---
 drivers/md/raid0.c         |   12 ++++++------
 include/linux/raid/raid0.h |    2 +-
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index b860536..6e12a35 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -155,7 +155,7 @@ static int create_strip_zones (mddev_t *mddev)
 	}
 	zone->nb_dev = cnt;
 	zone->size = smallest->size * cnt;
-	zone->zone_offset = 0;
+	zone->zone_start = 0;
 
 	current_offset = smallest->size;
 	curr_zone_offset = zone->size;
@@ -194,7 +194,7 @@ static int create_strip_zones (mddev_t *mddev)
 		printk("raid0: zone->nb_dev: %d, size: %llu\n",
 			zone->nb_dev, (unsigned long long)zone->size);
 
-		zone->zone_offset = curr_zone_offset;
+		zone->zone_start = curr_zone_offset * 2;
 		curr_zone_offset += zone->size;
 
 		current_offset = smallest->size;
@@ -437,14 +437,14 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
 		zone = conf->hash_table[x];
 	}
  
-	while (sector / 2 >= (zone->zone_offset + zone->size))
+	while (sector / 2 >= (zone->zone_start / 2 + zone->size))
 		zone++;
     
 	sect_in_chunk = bio->bi_sector & (chunk_sects - 1);
 
 
 	{
-		sector_t x = (sector - zone->zone_offset * 2) >> chunksect_bits;
+		sector_t x = (sector - zone->zone_start) >> chunksect_bits;
 
 		sector_div(x, zone->nb_dev);
 		chunk = x;
@@ -489,8 +489,8 @@ static void raid0_status (struct seq_file *seq, mddev_t *mddev)
 			seq_printf(seq, "%s/", bdevname(
 				conf->strip_zone[j].dev[k]->bdev,b));
 
-		seq_printf(seq, "] zo=%d ds=%d s=%d\n",
-				conf->strip_zone[j].zone_offset,
+		seq_printf(seq, "] zs=%d ds=%d s=%d\n",
+				conf->strip_zone[j].zone_start,
 				conf->strip_zone[j].dev_start,
 				conf->strip_zone[j].size);
 	}
diff --git a/include/linux/raid/raid0.h b/include/linux/raid/raid0.h
index 61c3d29..eaf4f6a 100644
--- a/include/linux/raid/raid0.h
+++ b/include/linux/raid/raid0.h
@@ -5,7 +5,7 @@
 
 struct strip_zone
 {
-	sector_t zone_offset;	/* Zone offset in md_dev */
+	sector_t zone_start;	/* Zone offset in md_dev (in sectors) */
 	sector_t dev_start;	/* Zone offset in real dev (in sectors) */
 	sector_t size;		/* Zone size */
 	int nb_dev;		/* # of devices attached to the zone */
-- 
1.5.3.8

[PATCH 6/9] md: raid0 create_strip_zones(): Make two local variables sector-based.

[Andre Noll]

current_offset and curr_zone_offset stored the corresponding offsets
as 1K quantities. Rename them to current_start and curr_zone_start
to match the naming of struct strip_zone and store the offsets as
sector counts.

Also, add KERN_INFO to the printk() affected by this change to make
checkpatch happy.
---
 drivers/md/raid0.c |   27 +++++++++++++--------------
 1 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 6e12a35..9074ea4 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -53,7 +53,7 @@ static int raid0_congested(void *data, int bits)
 static int create_strip_zones (mddev_t *mddev)
 {
 	int i, c, j;
-	sector_t current_offset, curr_zone_offset;
+	sector_t current_start, curr_zone_start;
 	sector_t min_spacing;
 	raid0_conf_t *conf = mddev_to_conf(mddev);
 	mdk_rdev_t *smallest, *rdev1, *rdev2, *rdev;
@@ -157,8 +157,8 @@ static int create_strip_zones (mddev_t *mddev)
 	zone->size = smallest->size * cnt;
 	zone->zone_start = 0;
 
-	current_offset = smallest->size;
-	curr_zone_offset = zone->size;
+	current_start = smallest->size * 2;
+	curr_zone_start = zone->size * 2;
 
 	/* now do the other zones */
 	for (i = 1; i < conf->nr_strip_zones; i++)
@@ -167,7 +167,7 @@ static int create_strip_zones (mddev_t *mddev)
 		zone->dev = conf->strip_zone[i-1].dev + mddev->raid_disks;
 
 		printk("raid0: zone %d\n", i);
-		zone->dev_start = current_offset * 2;
+		zone->dev_start = current_start;
 		smallest = NULL;
 		c = 0;
 
@@ -175,8 +175,7 @@ static int create_strip_zones (mddev_t *mddev)
 			char b[BDEVNAME_SIZE];
 			rdev = conf->strip_zone[0].dev[j];
 			printk("raid0: checking %s ...", bdevname(rdev->bdev,b));
-			if (rdev->size > current_offset)
-			{
+			if (rdev->size > current_start / 2) {
 				printk(" contained as device %d\n", c);
 				zone->dev[c] = rdev;
 				c++;
@@ -190,16 +189,16 @@ static int create_strip_zones (mddev_t *mddev)
 		}
 
 		zone->nb_dev = c;
-		zone->size = (smallest->size - current_offset) * c;
+		zone->size = (smallest->size - current_start / 2) * c;
 		printk("raid0: zone->nb_dev: %d, size: %llu\n",
 			zone->nb_dev, (unsigned long long)zone->size);
 
-		zone->zone_start = curr_zone_offset * 2;
-		curr_zone_offset += zone->size;
+		zone->zone_start = curr_zone_start;
+		curr_zone_start += zone->size * 2;
 
-		current_offset = smallest->size;
-		printk("raid0: current zone offset: %llu\n",
-			(unsigned long long)current_offset);
+		current_start = smallest->size * 2;
+		printk(KERN_INFO "raid0: current zone start: %llu\n",
+			(unsigned long long)current_start);
 	}
 
 	/* Now find appropriate hash spacing.
@@ -210,8 +209,8 @@ static int create_strip_zones (mddev_t *mddev)
 	 * strip though as it's size has no bearing on the efficacy of the hash
 	 * table.
 	 */
-	conf->hash_spacing = curr_zone_offset;
-	min_spacing = curr_zone_offset;
+	conf->hash_spacing = curr_zone_start / 2;
+	min_spacing = curr_zone_start / 2;
 	sector_div(min_spacing, PAGE_SIZE/sizeof(struct strip_zone*));
 	for (i=0; i < conf->nr_strip_zones-1; i++) {
 		sector_t sz = 0;
-- 
1.5.3.8

[PATCH 7/9] md: raid0 create_strip_zones(): Add KERN_INFO/KERN_ERR to printk's.

[Andre Noll]

This patch consists only of these trivial changes.
---
 drivers/md/raid0.c |   46 +++++++++++++++++++++++++---------------------
 1 files changed, 25 insertions(+), 21 deletions(-)

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 9074ea4..c759436 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -68,18 +68,18 @@ static int create_strip_zones (mddev_t *mddev)
 	conf->nr_strip_zones = 0;
  
 	rdev_for_each(rdev1, tmp1, mddev) {
-		printk("raid0: looking at %s\n",
+		printk(KERN_INFO "raid0: looking at %s\n",
 			bdevname(rdev1->bdev,b));
 		c = 0;
 		rdev_for_each(rdev2, tmp2, mddev) {
-			printk("raid0:   comparing %s(%llu)",
+			printk(KERN_INFO "raid0:   comparing %s(%llu)",
 			       bdevname(rdev1->bdev,b),
 			       (unsigned long long)rdev1->size);
-			printk(" with %s(%llu)\n",
+			printk(KERN_INFO " with %s(%llu)\n",
 			       bdevname(rdev2->bdev,b),
 			       (unsigned long long)rdev2->size);
 			if (rdev2 == rdev1) {
-				printk("raid0:   END\n");
+				printk(KERN_INFO "raid0:   END\n");
 				break;
 			}
 			if (rdev2->size == rdev1->size)
@@ -88,19 +88,20 @@ static int create_strip_zones (mddev_t *mddev)
 				 * Not unique, don't count it as a new
 				 * group
 				 */
-				printk("raid0:   EQUAL\n");
+				printk(KERN_INFO "raid0:   EQUAL\n");
 				c = 1;
 				break;
 			}
-			printk("raid0:   NOT EQUAL\n");
+			printk(KERN_INFO "raid0:   NOT EQUAL\n");
 		}
 		if (!c) {
-			printk("raid0:   ==> UNIQUE\n");
+			printk(KERN_INFO "raid0:   ==> UNIQUE\n");
 			conf->nr_strip_zones++;
-			printk("raid0: %d zones\n", conf->nr_strip_zones);
+			printk(KERN_INFO "raid0: %d zones\n",
+				conf->nr_strip_zones);
 		}
 	}
-	printk("raid0: FINAL %d zones\n", conf->nr_strip_zones);
+	printk(KERN_INFO "raid0: FINAL %d zones\n", conf->nr_strip_zones);
 
 	conf->strip_zone = kzalloc(sizeof(struct strip_zone)*
 				conf->nr_strip_zones, GFP_KERNEL);
@@ -123,12 +124,13 @@ static int create_strip_zones (mddev_t *mddev)
 		int j = rdev1->raid_disk;
 
 		if (j < 0 || j >= mddev->raid_disks) {
-			printk("raid0: bad disk number %d - aborting!\n", j);
+			printk(KERN_ERR "raid0: bad disk number %d - "
+				"aborting!\n", j);
 			goto abort;
 		}
 		if (zone->dev[j]) {
-			printk("raid0: multiple devices for %d - aborting!\n",
-				j);
+			printk(KERN_ERR "raid0: multiple devices for %d - "
+				"aborting!\n", j);
 			goto abort;
 		}
 		zone->dev[j] = rdev1;
@@ -149,8 +151,8 @@ static int create_strip_zones (mddev_t *mddev)
 		cnt++;
 	}
 	if (cnt != mddev->raid_disks) {
-		printk("raid0: too few disks (%d of %d) - aborting!\n",
-			cnt, mddev->raid_disks);
+		printk(KERN_ERR "raid0: too few disks (%d of %d) - "
+			"aborting!\n", cnt, mddev->raid_disks);
 		goto abort;
 	}
 	zone->nb_dev = cnt;
@@ -166,7 +168,7 @@ static int create_strip_zones (mddev_t *mddev)
 		zone = conf->strip_zone + i;
 		zone->dev = conf->strip_zone[i-1].dev + mddev->raid_disks;
 
-		printk("raid0: zone %d\n", i);
+		printk(KERN_INFO "raid0: zone %d\n", i);
 		zone->dev_start = current_start;
 		smallest = NULL;
 		c = 0;
@@ -174,23 +176,25 @@ static int create_strip_zones (mddev_t *mddev)
 		for (j=0; j<cnt; j++) {
 			char b[BDEVNAME_SIZE];
 			rdev = conf->strip_zone[0].dev[j];
-			printk("raid0: checking %s ...", bdevname(rdev->bdev,b));
+			printk(KERN_INFO "raid0: checking %s ...",
+				bdevname(rdev->bdev, b));
 			if (rdev->size > current_start / 2) {
-				printk(" contained as device %d\n", c);
+				printk(KERN_INFO " contained as device %d\n",
+					c);
 				zone->dev[c] = rdev;
 				c++;
 				if (!smallest || (rdev->size <smallest->size)) {
 					smallest = rdev;
-					printk("  (%llu) is smallest!.\n", 
+					printk(KERN_INFO "  (%llu) is smallest!.\n",
 						(unsigned long long)rdev->size);
 				}
 			} else
-				printk(" nope.\n");
+				printk(KERN_INFO " nope.\n");
 		}
 
 		zone->nb_dev = c;
 		zone->size = (smallest->size - current_start / 2) * c;
-		printk("raid0: zone->nb_dev: %d, size: %llu\n",
+		printk(KERN_INFO "raid0: zone->nb_dev: %d, size: %llu\n",
 			zone->nb_dev, (unsigned long long)zone->size);
 
 		zone->zone_start = curr_zone_start;
@@ -226,7 +230,7 @@ static int create_strip_zones (mddev_t *mddev)
 	mddev->queue->backing_dev_info.congested_fn = raid0_congested;
 	mddev->queue->backing_dev_info.congested_data = mddev;
 
-	printk("raid0: done.\n");
+	printk(KERN_INFO "raid0: done.\n");
 	return 0;
  abort:
 	return 1;
-- 
1.5.3.8

[PATCH 8/9] md: raid0: Represent the size of strip zones in sectors.

[Andre Noll]

This completes the block -> sector conversion of struct strip_zone.
---
 drivers/md/raid0.c         |   26 +++++++++++++-------------
 include/linux/raid/raid0.h |    2 +-
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index c759436..6e85e88 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -156,11 +156,11 @@ static int create_strip_zones (mddev_t *mddev)
 		goto abort;
 	}
 	zone->nb_dev = cnt;
-	zone->size = smallest->size * cnt;
+	zone->sectors = smallest->size * cnt * 2;
 	zone->zone_start = 0;
 
 	current_start = smallest->size * 2;
-	curr_zone_start = zone->size * 2;
+	curr_zone_start = zone->sectors;
 
 	/* now do the other zones */
 	for (i = 1; i < conf->nr_strip_zones; i++)
@@ -193,12 +193,12 @@ static int create_strip_zones (mddev_t *mddev)
 		}
 
 		zone->nb_dev = c;
-		zone->size = (smallest->size - current_start / 2) * c;
-		printk(KERN_INFO "raid0: zone->nb_dev: %d, size: %llu\n",
-			zone->nb_dev, (unsigned long long)zone->size);
+		zone->sectors = (smallest->size * 2 - current_start) * c;
+		printk(KERN_INFO "raid0: zone->nb_dev: %d, sectors: %llu\n",
+			zone->nb_dev, (unsigned long long)zone->sectors);
 
 		zone->zone_start = curr_zone_start;
-		curr_zone_start += zone->size * 2;
+		curr_zone_start += zone->sectors;
 
 		current_start = smallest->size * 2;
 		printk(KERN_INFO "raid0: current zone start: %llu\n",
@@ -220,7 +220,7 @@ static int create_strip_zones (mddev_t *mddev)
 		sector_t sz = 0;
 		for (j=i; j<conf->nr_strip_zones-1 &&
 			     sz < min_spacing ; j++)
-			sz += conf->strip_zone[j].size;
+			sz += conf->strip_zone[j].sectors / 2;
 		if (sz >= min_spacing && sz < conf->hash_spacing)
 			conf->hash_spacing = sz;
 	}
@@ -325,13 +325,13 @@ static int raid0_run (mddev_t *mddev)
 	conf->hash_table = kmalloc (sizeof (struct strip_zone *)*nb_zone, GFP_KERNEL);
 	if (!conf->hash_table)
 		goto out_free_conf;
-	size = conf->strip_zone[cur].size;
+	size = conf->strip_zone[cur].sectors / 2;
 
 	conf->hash_table[0] = conf->strip_zone + cur;
 	for (i=1; i< nb_zone; i++) {
 		while (size <= conf->hash_spacing) {
 			cur++;
-			size += conf->strip_zone[cur].size;
+			size += conf->strip_zone[cur].sectors / 2;
 		}
 		size -= conf->hash_spacing;
 		conf->hash_table[i] = conf->strip_zone + cur;
@@ -439,10 +439,10 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
 		sector_div(x, (u32)conf->hash_spacing);
 		zone = conf->hash_table[x];
 	}
- 
-	while (sector / 2 >= (zone->zone_start / 2 + zone->size))
+
+	while (sector >= zone->zone_start + zone->sectors)
 		zone++;
-    
+
 	sect_in_chunk = bio->bi_sector & (chunk_sects - 1);
 
 
@@ -495,7 +495,7 @@ static void raid0_status (struct seq_file *seq, mddev_t *mddev)
 		seq_printf(seq, "] zs=%d ds=%d s=%d\n",
 				conf->strip_zone[j].zone_start,
 				conf->strip_zone[j].dev_start,
-				conf->strip_zone[j].size);
+				conf->strip_zone[j].sectors);
 	}
 #endif
 	seq_printf(seq, " %dk chunks", mddev->chunk_size/1024);
diff --git a/include/linux/raid/raid0.h b/include/linux/raid/raid0.h
index eaf4f6a..c12521d 100644
--- a/include/linux/raid/raid0.h
+++ b/include/linux/raid/raid0.h
@@ -7,7 +7,7 @@ struct strip_zone
 {
 	sector_t zone_start;	/* Zone offset in md_dev (in sectors) */
 	sector_t dev_start;	/* Zone offset in real dev (in sectors) */
-	sector_t size;		/* Zone size */
+	sector_t sectors;	/* Zone size in sectors */
 	int nb_dev;		/* # of devices attached to the zone */
 	mdk_rdev_t **dev;	/* Devices attached to the zone */
 };
-- 
1.5.3.8

[PATCH 9/9] md: raid0: make hash_spacing and preshift sector-based.

[Andre Noll]

This patch renames the hash_spacing and preshift members of struct
raid0_private_data to spacing and sector_shift respectively and
changes the semantics as follows:

We always have spacing = 2 * hash_spacing. In case
sizeof(sector_t) > sizeof(u32) we also have sector_shift = preshift + 1
while sector_shift = preshift = 0 otherwise.

Note that the values of nb_zone and zone are unaffected by these changes
because in the sector_div() preceeding the assignement of these two
variables both arguments double.
---
 drivers/md/raid0.c         |   58 ++++++++++++++++++++++----------------------
 include/linux/raid/raid0.h |    4 +-
 2 files changed, 31 insertions(+), 31 deletions(-)

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 6e85e88..90f5b24 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -213,16 +213,16 @@ static int create_strip_zones (mddev_t *mddev)
 	 * strip though as it's size has no bearing on the efficacy of the hash
 	 * table.
 	 */
-	conf->hash_spacing = curr_zone_start / 2;
-	min_spacing = curr_zone_start / 2;
+	conf->spacing = curr_zone_start;
+	min_spacing = curr_zone_start;
 	sector_div(min_spacing, PAGE_SIZE/sizeof(struct strip_zone*));
 	for (i=0; i < conf->nr_strip_zones-1; i++) {
-		sector_t sz = 0;
-		for (j=i; j<conf->nr_strip_zones-1 &&
-			     sz < min_spacing ; j++)
-			sz += conf->strip_zone[j].sectors / 2;
-		if (sz >= min_spacing && sz < conf->hash_spacing)
-			conf->hash_spacing = sz;
+		sector_t s = 0;
+		for (j = i; j < conf->nr_strip_zones - 1 &&
+				s < min_spacing; j++)
+			s += conf->strip_zone[j].sectors;
+		if (s >= min_spacing && s < conf->spacing)
+			conf->spacing = s;
 	}
 
 	mddev->queue->unplug_fn = raid0_unplug;
@@ -265,7 +265,7 @@ static int raid0_mergeable_bvec(struct request_queue *q,
 static int raid0_run (mddev_t *mddev)
 {
 	unsigned  cur=0, i=0, nb_zone;
-	s64 size;
+	s64 sectors;
 	raid0_conf_t *conf;
 	mdk_rdev_t *rdev;
 	struct list_head *tmp;
@@ -297,51 +297,51 @@ static int raid0_run (mddev_t *mddev)
 	rdev_for_each(rdev, tmp, mddev)
 		mddev->array_sectors += rdev->size * 2;
 
-	printk("raid0 : md_size is %llu blocks.\n", 
-		(unsigned long long)mddev->array_sectors / 2);
-	printk("raid0 : conf->hash_spacing is %llu blocks.\n",
-		(unsigned long long)conf->hash_spacing);
+	printk(KERN_INFO "raid0 : md_size is %llu sectors.\n",
+		(unsigned long long)mddev->array_sectors);
+	printk(KERN_INFO "raid0 : conf->spacing is %llu sectors.\n",
+		(unsigned long long)conf->spacing);
 	{
-		sector_t s = mddev->array_sectors / 2;
-		sector_t space = conf->hash_spacing;
+		sector_t s = mddev->array_sectors;
+		sector_t space = conf->spacing;
 		int round;
-		conf->preshift = 0;
+		conf->sector_shift = 0;
 		if (sizeof(sector_t) > sizeof(u32)) {
 			/*shift down space and s so that sector_div will work */
 			while (space > (sector_t) (~(u32)0)) {
 				s >>= 1;
 				space >>= 1;
 				s += 1; /* force round-up */
-				conf->preshift++;
+				conf->sector_shift++;
 			}
 		}
 		round = sector_div(s, (u32)space) ? 1 : 0;
 		nb_zone = s + round;
 	}
-	printk("raid0 : nb_zone is %d.\n", nb_zone);
+	printk(KERN_INFO "raid0 : nb_zone is %d.\n", nb_zone);
 
-	printk("raid0 : Allocating %Zd bytes for hash.\n",
+	printk(KERN_INFO "raid0 : Allocating %zu bytes for hash.\n",
 				nb_zone*sizeof(struct strip_zone*));
 	conf->hash_table = kmalloc (sizeof (struct strip_zone *)*nb_zone, GFP_KERNEL);
 	if (!conf->hash_table)
 		goto out_free_conf;
-	size = conf->strip_zone[cur].sectors / 2;
+	sectors = conf->strip_zone[cur].sectors;
 
 	conf->hash_table[0] = conf->strip_zone + cur;
 	for (i=1; i< nb_zone; i++) {
-		while (size <= conf->hash_spacing) {
+		while (sectors <= conf->spacing) {
 			cur++;
-			size += conf->strip_zone[cur].sectors / 2;
+			sectors += conf->strip_zone[cur].sectors;
 		}
-		size -= conf->hash_spacing;
+		sectors -= conf->spacing;
 		conf->hash_table[i] = conf->strip_zone + cur;
 	}
-	if (conf->preshift) {
-		conf->hash_spacing >>= conf->preshift;
-		/* round hash_spacing up so when we divide by it, we
+	if (conf->sector_shift) {
+		conf->spacing >>= conf->sector_shift;
+		/* round spacing up so when we divide by it, we
 		 * err on the side of too-low, which is safest
 		 */
-		conf->hash_spacing++;
+		conf->spacing++;
 	}
 
 	/* calculate the max read-ahead size.
@@ -435,8 +435,8 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
  
 
 	{
-		sector_t x = sector >> (conf->preshift + 1);
-		sector_div(x, (u32)conf->hash_spacing);
+		sector_t x = sector >> conf->sector_shift;
+		sector_div(x, (u32)conf->spacing);
 		zone = conf->hash_table[x];
 	}
 
diff --git a/include/linux/raid/raid0.h b/include/linux/raid/raid0.h
index c12521d..fd42aa8 100644
--- a/include/linux/raid/raid0.h
+++ b/include/linux/raid/raid0.h
@@ -19,8 +19,8 @@ struct raid0_private_data
 	mdk_rdev_t **devlist; /* lists of rdevs, pointed to by strip_zone->dev */
 	int nr_strip_zones;
 
-	sector_t hash_spacing;
-	int preshift;			/* shift this before divide by hash_spacing */
+	sector_t spacing;
+	int sector_shift; /* shift this before divide by spacing */
 };
 
 typedef struct raid0_private_data raid0_conf_t;
-- 
1.5.3.8