md: raid0: remove ->dev pointer from strip_zone structure

If we treat conf->devlist more like a 2 dimensional array,
we can get the devlist for a particular zone simply by indexing
that array, so we don't need to store the pointers to subarrays
in strip_zone.  This makes strip_zone smaller and so (hopefully)
searches faster.

Signed-of-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 07ef936..af0df78 100644 (file)
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -27,7 +27,7 @@ static void raid0_unplug(struct request_queue *q)
 {
        mddev_t *mddev = q->queuedata;
        raid0_conf_t *conf = mddev_to_conf(mddev);
-       mdk_rdev_t **devlist = conf->strip_zone[0].dev;
+       mdk_rdev_t **devlist = conf->devlist;
        int i;
 
        for (i=0; i<mddev->raid_disks; i++) {
@@ -41,7 +41,7 @@ static int raid0_congested(void *data, int bits)
 {
        mddev_t *mddev = data;
        raid0_conf_t *conf = mddev_to_conf(mddev);
-       mdk_rdev_t **devlist = conf->strip_zone[0].dev;
+       mdk_rdev_t **devlist = conf->devlist;
        int i, ret = 0;
 
        for (i = 0; i < mddev->raid_disks && !ret ; i++) {
@@ -56,7 +56,7 @@ static int create_strip_zones(mddev_t *mddev)
 {
        int i, c, j, err;
        sector_t curr_zone_end, sectors;
-       mdk_rdev_t *smallest, *rdev1, *rdev2, *rdev;
+       mdk_rdev_t *smallest, *rdev1, *rdev2, *rdev, **dev;
        struct strip_zone *zone;
        int cnt;
        char b[BDEVNAME_SIZE];
@@ -115,7 +115,7 @@ static int create_strip_zones(mddev_t *mddev)
        zone = &conf->strip_zone[0];
        cnt = 0;
        smallest = NULL;
-       zone->dev = conf->devlist;
+       dev = conf->devlist;
        err = -EINVAL;
        list_for_each_entry(rdev1, &mddev->disks, same_set) {
                int j = rdev1->raid_disk;
@@ -125,12 +125,12 @@ static int create_strip_zones(mddev_t *mddev)
                                "aborting!\n", j);
                        goto abort;
                }
-               if (zone->dev[j]) {
+               if (dev[j]) {
                        printk(KERN_ERR "raid0: multiple devices for %d - "
                                "aborting!\n", j);
                        goto abort;
                }
-               zone->dev[j] = rdev1;
+               dev[j] = rdev1;
 
                blk_queue_stack_limits(mddev->queue,
                                       rdev1->bdev->bd_disk->queue);
@@ -161,7 +161,7 @@ static int create_strip_zones(mddev_t *mddev)
        for (i = 1; i < conf->nr_strip_zones; i++)
        {
                zone = conf->strip_zone + i;
-               zone->dev = conf->strip_zone[i-1].dev + mddev->raid_disks;
+               dev = conf->devlist + i * mddev->raid_disks;
 
                printk(KERN_INFO "raid0: zone %d\n", i);
                zone->dev_start = smallest->sectors;
@@ -170,7 +170,7 @@ 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];
+                       rdev = conf->devlist[j];
                        printk(KERN_INFO "raid0: checking %s ...",
                                bdevname(rdev->bdev, b));
                        if (rdev->sectors <= zone->dev_start) {
@@ -178,7 +178,7 @@ static int create_strip_zones(mddev_t *mddev)
                                continue;
                        }
                        printk(KERN_INFO " contained as device %d\n", c);
-                       zone->dev[c] = rdev;
+                       dev[c] = rdev;
                        c++;
                        if (!smallest || rdev->sectors < smallest->sectors) {
                                smallest = rdev;
@@ -383,7 +383,8 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
                chunk = x;
 
                x = sector >> chunksect_bits;
-               tmp_dev = zone->dev[sector_div(x, zone->nb_dev)];
+               tmp_dev = conf->devlist[(zone - conf->strip_zone)*mddev->raid_disks
+                                       + sector_div(x, zone->nb_dev)];
        }
        rsect = (chunk << chunksect_bits) + zone->dev_start + sect_in_chunk;
  

diff --git a/drivers/md/raid0.h b/drivers/md/raid0.h
index 124ba34..7b3605e 100644 (file)
--- a/drivers/md/raid0.h
+++ b/drivers/md/raid0.h
@@ -6,7 +6,6 @@ struct strip_zone
        sector_t zone_end;      /* Start of the next zone (in sectors) */
        sector_t dev_start;     /* Zone offset in real dev (in sectors) */
        int nb_dev;             /* # of devices attached to the zone */
-       mdk_rdev_t **dev;       /* Devices attached to the zone */
 };
 
 struct raid0_private_data