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authorAndre Noll <maan@systemlinux.org>2009-01-09 08:31:08 +1100
committerNeilBrown <neilb@suse.de>2009-01-09 08:31:08 +1100
commitccacc7d2cf03114a24ab903f710118e9e5d43273 (patch)
treec856e2a17f6c6a26996a8cfba87680a2375061d5
parent83838ed87898e0a8ff8dbf001e54e6c017f0a011 (diff)
md: raid0: make hash_spacing and preshift sector-based.
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. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
-rw-r--r--drivers/md/raid0.c58
-rw-r--r--include/linux/raid/raid0.h4
2 files changed, 31 insertions, 31 deletions
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 6e85e88bbae..90f5b24f6e6 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 c12521d027e..fd42aa87c39 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;