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