1 files changed, 211 insertions, 192 deletions

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 925507e7d673..ab4a489d8695 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -26,8 +26,8 @@
 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;
+        raid0_conf_t *conf = mddev->private;
+        mdk_rdev_t **devlist = conf->devlist;
         int i;
 
         for (i=0; i<mddev->raid_disks; i++) {
@@ -40,8 +40,8 @@ static void raid0_unplug(struct request_queue *q)
 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;
+        raid0_conf_t *conf = mddev->private;
+        mdk_rdev_t **devlist = conf->devlist;
         int i, ret = 0;
 
         for (i = 0; i < mddev->raid_disks && !ret ; i++) {
@@ -52,27 +52,60 @@ static int raid0_congested(void *data, int bits)
         return ret;
 }
 
+/*
+ * inform the user of the raid configuration
+*/
+static void dump_zones(mddev_t *mddev)
+{
+        int j, k, h;
+        sector_t zone_size = 0;
+        sector_t zone_start = 0;
+        char b[BDEVNAME_SIZE];
+        raid0_conf_t *conf = mddev->private;
+        printk(KERN_INFO "******* %s configuration *********\n",
+                mdname(mddev));
+        h = 0;
+        for (j = 0; j < conf->nr_strip_zones; j++) {
+                printk(KERN_INFO "zone%d=[", j);
+                for (k = 0; k < conf->strip_zone[j].nb_dev; k++)
+                        printk("%s/",
+                        bdevname(conf->devlist[j*mddev->raid_disks
+                                                + k]->bdev, b));
+                printk("]\n");
+
+                zone_size  = conf->strip_zone[j].zone_end - zone_start;
+                printk(KERN_INFO "        zone offset=%llukb "
+                                "device offset=%llukb size=%llukb\n",
+                        (unsigned long long)zone_start>>1,
+                        (unsigned long long)conf->strip_zone[j].dev_start>>1,
+                        (unsigned long long)zone_size>>1);
+                zone_start = conf->strip_zone[j].zone_end;
+        }
+        printk(KERN_INFO "**********************************\n\n");
+}
 
-static int create_strip_zones (mddev_t *mddev)
+static int create_strip_zones(mddev_t *mddev)
 {
-        int i, c, j;
-        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;
+        int i, c, j, err;
+        sector_t curr_zone_end, sectors;
+        mdk_rdev_t *smallest, *rdev1, *rdev2, *rdev, **dev;
         struct strip_zone *zone;
         int cnt;
         char b[BDEVNAME_SIZE];
- 
-        /*
-         * The number of 'same size groups'
-         */
-        conf->nr_strip_zones = 0;
- 
+        raid0_conf_t *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
+
+        if (!conf)
+                return -ENOMEM;
         list_for_each_entry(rdev1, &mddev->disks, same_set) {
                 printk(KERN_INFO "raid0: looking at %s\n",
                         bdevname(rdev1->bdev,b));
                 c = 0;
+
+                /* round size to chunk_size */
+                sectors = rdev1->sectors;
+                sector_div(sectors, mddev->chunk_sectors);
+                rdev1->sectors = sectors * mddev->chunk_sectors;
+
                 list_for_each_entry(rdev2, &mddev->disks, same_set) {
                         printk(KERN_INFO "raid0:   comparing %s(%llu)",
                                bdevname(rdev1->bdev,b),
@@ -103,16 +136,16 @@ static int create_strip_zones (mddev_t *mddev)
                 }
         }
         printk(KERN_INFO "raid0: FINAL %d zones\n", conf->nr_strip_zones);
-
+        err = -ENOMEM;
         conf->strip_zone = kzalloc(sizeof(struct strip_zone)*
                                 conf->nr_strip_zones, GFP_KERNEL);
         if (!conf->strip_zone)
-                return 1;
+                goto abort;
         conf->devlist = kzalloc(sizeof(mdk_rdev_t*)*
                                 conf->nr_strip_zones*mddev->raid_disks,
                                 GFP_KERNEL);
         if (!conf->devlist)
-                return 1;
+                goto abort;
 
         /* The first zone must contain all devices, so here we check that
          * there is a proper alignment of slots to devices and find them all
@@ -120,7 +153,8 @@ 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;
 
@@ -129,12 +163,12 @@ 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);
@@ -157,34 +191,32 @@ static int create_strip_zones (mddev_t *mddev)
                 goto abort;
         }
         zone->nb_dev = cnt;
-        zone->sectors = smallest->sectors * cnt;
-        zone->zone_start = 0;
+        zone->zone_end = smallest->sectors * cnt;
 
-        current_start = smallest->sectors;
-        curr_zone_start = zone->sectors;
+        curr_zone_end = zone->zone_end;
 
         /* now do the other zones */
         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 = current_start;
+                zone->dev_start = smallest->sectors;
                 smallest = NULL;
                 c = 0;
 
                 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 <= current_start) {
+                        if (rdev->sectors <= zone->dev_start) {
                                 printk(KERN_INFO " nope.\n");
                                 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;
@@ -194,47 +226,39 @@ static int create_strip_zones (mddev_t *mddev)
                 }
 
                 zone->nb_dev = c;
-                zone->sectors = (smallest->sectors - current_start) * c;
+                sectors = (smallest->sectors - zone->dev_start) * c;
                 printk(KERN_INFO "raid0: zone->nb_dev: %d, sectors: %llu\n",
-                        zone->nb_dev, (unsigned long long)zone->sectors);
+                        zone->nb_dev, (unsigned long long)sectors);
 
-                zone->zone_start = curr_zone_start;
-                curr_zone_start += zone->sectors;
+                curr_zone_end += sectors;
+                zone->zone_end = curr_zone_end;
 
-                current_start = smallest->sectors;
                 printk(KERN_INFO "raid0: current zone start: %llu\n",
-                        (unsigned long long)current_start);
-        }
-
-        /* Now find appropriate hash spacing.
-         * We want a number which causes most hash entries to cover
-         * at most two strips, but the hash table must be at most
-         * 1 PAGE.  We choose the smallest strip, or contiguous collection
-         * of strips, that has big enough size.  We never consider the last
-         * strip though as it's size has no bearing on the efficacy of the hash
-         * table.
-         */
-        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 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;
+                        (unsigned long long)smallest->sectors);
         }
-
         mddev->queue->unplug_fn = raid0_unplug;
-
         mddev->queue->backing_dev_info.congested_fn = raid0_congested;
         mddev->queue->backing_dev_info.congested_data = mddev;
 
+        /*
+         * now since we have the hard sector sizes, we can make sure
+         * chunk size is a multiple of that sector size
+         */
+        if ((mddev->chunk_sectors << 9) % queue_logical_block_size(mddev->queue)) {
+                printk(KERN_ERR "%s chunk_size of %d not valid\n",
+                       mdname(mddev),
+                       mddev->chunk_sectors << 9);
+                goto abort;
+        }
         printk(KERN_INFO "raid0: done.\n");
+        mddev->private = conf;
         return 0;
- abort:
-        return 1;
+abort:
+        kfree(conf->strip_zone);
+        kfree(conf->devlist);
+        kfree(conf);
+        mddev->private = NULL;
+        return err;
 }
 
 /**
@@ -252,10 +276,15 @@ static int raid0_mergeable_bvec(struct request_queue *q,
         mddev_t *mddev = q->queuedata;
         sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
         int max;
-        unsigned int chunk_sectors = mddev->chunk_size >> 9;
+        unsigned int chunk_sectors = mddev->chunk_sectors;
         unsigned int bio_sectors = bvm->bi_size >> 9;
 
-        max =  (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
+        if (is_power_of_2(chunk_sectors))
+                max =  (chunk_sectors - ((sector & (chunk_sectors-1))
+                                                + bio_sectors)) << 9;
+        else
+                max =  (chunk_sectors - (sector_div(sector, chunk_sectors)
+                                                + bio_sectors)) << 9;
         if (max < 0) max = 0; /* bio_add cannot handle a negative return */
         if (max <= biovec->bv_len && bio_sectors == 0)
                 return biovec->bv_len;
@@ -277,84 +306,28 @@ static sector_t raid0_size(mddev_t *mddev, sector_t sectors, int raid_disks)
         return array_sectors;
 }
 
-static int raid0_run (mddev_t *mddev)
+static int raid0_run(mddev_t *mddev)
 {
-        unsigned  cur=0, i=0, nb_zone;
-        s64 sectors;
-        raid0_conf_t *conf;
+        int ret;
 
-        if (mddev->chunk_size == 0) {
-                printk(KERN_ERR "md/raid0: non-zero chunk size required.\n");
+        if (mddev->chunk_sectors == 0) {
+                printk(KERN_ERR "md/raid0: chunk size must be set.\n");
                 return -EINVAL;
         }
-        printk(KERN_INFO "%s: setting max_sectors to %d, segment boundary to %d\n",
-               mdname(mddev),
-               mddev->chunk_size >> 9,
-               (mddev->chunk_size>>1)-1);
-        blk_queue_max_sectors(mddev->queue, mddev->chunk_size >> 9);
-        blk_queue_segment_boundary(mddev->queue, (mddev->chunk_size>>1) - 1);
+        if (md_check_no_bitmap(mddev))
+                return -EINVAL;
+        blk_queue_max_sectors(mddev->queue, mddev->chunk_sectors);
         mddev->queue->queue_lock = &mddev->queue->__queue_lock;
 
-        conf = kmalloc(sizeof (raid0_conf_t), GFP_KERNEL);
-        if (!conf)
-                goto out;
-        mddev->private = (void *)conf;
- 
-        conf->strip_zone = NULL;
-        conf->devlist = NULL;
-        if (create_strip_zones (mddev)) 
-                goto out_free_conf;
+        ret = create_strip_zones(mddev);
+        if (ret < 0)
+                return ret;
 
         /* calculate array device size */
         md_set_array_sectors(mddev, raid0_size(mddev, 0, 0));
 
         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 = raid0_size(mddev, 0, 0);
-                sector_t space = conf->spacing;
-                int round;
-                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->sector_shift++;
-                        }
-                }
-                round = sector_div(s, (u32)space) ? 1 : 0;
-                nb_zone = s + round;
-        }
-        printk(KERN_INFO "raid0 : nb_zone is %d.\n", nb_zone);
-
-        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;
-        sectors = conf->strip_zone[cur].sectors;
-
-        conf->hash_table[0] = conf->strip_zone + cur;
-        for (i=1; i< nb_zone; i++) {
-                while (sectors <= conf->spacing) {
-                        cur++;
-                        sectors += conf->strip_zone[cur].sectors;
-                }
-                sectors -= conf->spacing;
-                conf->hash_table[i] = conf->strip_zone + cur;
-        }
-        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->spacing++;
-        }
-
         /* calculate the max read-ahead size.
          * For read-ahead of large files to be effective, we need to
          * readahead at least twice a whole stripe. i.e. number of devices
@@ -365,48 +338,107 @@ static int raid0_run (mddev_t *mddev)
          * chunksize should be used in that case.
          */
         {
-                int stripe = mddev->raid_disks * mddev->chunk_size / PAGE_SIZE;
+                int stripe = mddev->raid_disks *
+                        (mddev->chunk_sectors << 9) / PAGE_SIZE;
                 if (mddev->queue->backing_dev_info.ra_pages < 2* stripe)
                         mddev->queue->backing_dev_info.ra_pages = 2* stripe;
         }
 
-
         blk_queue_merge_bvec(mddev->queue, raid0_mergeable_bvec);
+        dump_zones(mddev);
         return 0;
+}
 
-out_free_conf:
+static int raid0_stop(mddev_t *mddev)
+{
+        raid0_conf_t *conf = mddev->private;
+
+        blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
         kfree(conf->strip_zone);
         kfree(conf->devlist);
         kfree(conf);
         mddev->private = NULL;
-out:
-        return -ENOMEM;
+        return 0;
 }
 
-static int raid0_stop (mddev_t *mddev)
+/* Find the zone which holds a particular offset
+ * Update *sectorp to be an offset in that zone
+ */
+static struct strip_zone *find_zone(struct raid0_private_data *conf,
+                                    sector_t *sectorp)
 {
-        raid0_conf_t *conf = mddev_to_conf(mddev);
+        int i;
+        struct strip_zone *z = conf->strip_zone;
+        sector_t sector = *sectorp;
+
+        for (i = 0; i < conf->nr_strip_zones; i++)
+                if (sector < z[i].zone_end) {
+                        if (i)
+                                *sectorp = sector - z[i-1].zone_end;
+                        return z + i;
+                }
+        BUG();
+}
 
-        blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
-        kfree(conf->hash_table);
-        conf->hash_table = NULL;
-        kfree(conf->strip_zone);
-        conf->strip_zone = NULL;
-        kfree(conf);
-        mddev->private = NULL;
+/*
+ * remaps the bio to the target device. we separate two flows.
+ * power 2 flow and a general flow for the sake of perfromance
+*/
+static mdk_rdev_t *map_sector(mddev_t *mddev, struct strip_zone *zone,
+                                sector_t sector, sector_t *sector_offset)
+{
+        unsigned int sect_in_chunk;
+        sector_t chunk;
+        raid0_conf_t *conf = mddev->private;
+        unsigned int chunk_sects = mddev->chunk_sectors;
+
+        if (is_power_of_2(chunk_sects)) {
+                int chunksect_bits = ffz(~chunk_sects);
+                /* find the sector offset inside the chunk */
+                sect_in_chunk  = sector & (chunk_sects - 1);
+                sector >>= chunksect_bits;
+                /* chunk in zone */
+                chunk = *sector_offset;
+                /* quotient is the chunk in real device*/
+                sector_div(chunk, zone->nb_dev << chunksect_bits);
+        } else{
+                sect_in_chunk = sector_div(sector, chunk_sects);
+                chunk = *sector_offset;
+                sector_div(chunk, chunk_sects * zone->nb_dev);
+        }
+        /*
+        *  position the bio over the real device
+        *  real sector = chunk in device + starting of zone
+        *       + the position in the chunk
+        */
+        *sector_offset = (chunk * chunk_sects) + sect_in_chunk;
+        return conf->devlist[(zone - conf->strip_zone)*mddev->raid_disks
+                             + sector_div(sector, zone->nb_dev)];
+}
 
-        return 0;
+/*
+ * Is io distribute over 1 or more chunks ?
+*/
+static inline int is_io_in_chunk_boundary(mddev_t *mddev,
+                        unsigned int chunk_sects, struct bio *bio)
+{
+        if (likely(is_power_of_2(chunk_sects))) {
+                return chunk_sects >= ((bio->bi_sector & (chunk_sects-1))
+                                        + (bio->bi_size >> 9));
+        } else{
+                sector_t sector = bio->bi_sector;
+                return chunk_sects >= (sector_div(sector, chunk_sects)
+                                                + (bio->bi_size >> 9));
+        }
 }
 
-static int raid0_make_request (struct request_queue *q, struct bio *bio)
+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_sects;
-        raid0_conf_t *conf = mddev_to_conf(mddev);
+        unsigned int chunk_sects;
+        sector_t sector_offset;
         struct strip_zone *zone;
         mdk_rdev_t *tmp_dev;
-        sector_t chunk;
-        sector_t sector, rsect;
         const int rw = bio_data_dir(bio);
         int cpu;
 
@@ -421,11 +453,9 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
                       bio_sectors(bio));
         part_stat_unlock();
 
-        chunk_sects = mddev->chunk_size >> 9;
-        chunksect_bits = ffz(~chunk_sects);
-        sector = bio->bi_sector;
-
-        if (unlikely(chunk_sects < (bio->bi_sector & (chunk_sects - 1)) + (bio->bi_size >> 9))) {
+        chunk_sects = mddev->chunk_sectors;
+        if (unlikely(!is_io_in_chunk_boundary(mddev, chunk_sects, bio))) {
+                sector_t sector = bio->bi_sector;
                 struct bio_pair *bp;
                 /* Sanity check -- queue functions should prevent this happening */
                 if (bio->bi_vcnt != 1 ||
@@ -434,7 +464,12 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
                 /* This is a one page bio that upper layers
                  * refuse to split for us, so we need to split it.
                  */
-                bp = bio_split(bio, chunk_sects - (bio->bi_sector & (chunk_sects - 1)));
+                if (likely(is_power_of_2(chunk_sects)))
+                        bp = bio_split(bio, chunk_sects - (sector &
+                                                           (chunk_sects-1)));
+                else
+                        bp = bio_split(bio, chunk_sects -
+                                       sector_div(sector, chunk_sects));
                 if (raid0_make_request(q, &bp->bio1))
                         generic_make_request(&bp->bio1);
                 if (raid0_make_request(q, &bp->bio2))
@@ -443,34 +478,14 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
                 bio_pair_release(bp);
                 return 0;
         }
- 
-
-        {
-                sector_t x = sector >> conf->sector_shift;
-                sector_div(x, (u32)conf->spacing);
-                zone = conf->hash_table[x];
-        }
 
-        while (sector >= zone->zone_start + zone->sectors)
-                zone++;
-
-        sect_in_chunk = bio->bi_sector & (chunk_sects - 1);
-
-
-        {
-                sector_t x = (sector - zone->zone_start) >> chunksect_bits;
-
-                sector_div(x, zone->nb_dev);
-                chunk = x;
-
-                x = sector >> chunksect_bits;
-                tmp_dev = zone->dev[sector_div(x, zone->nb_dev)];
-        }
-        rsect = (chunk << chunksect_bits) + zone->dev_start + sect_in_chunk;
- 
+        sector_offset = bio->bi_sector;
+        zone =  find_zone(mddev->private, &sector_offset);
+        tmp_dev = map_sector(mddev, zone, bio->bi_sector,
+                             &sector_offset);
         bio->bi_bdev = tmp_dev->bdev;
-        bio->bi_sector = rsect + tmp_dev->data_offset;
-
+        bio->bi_sector = sector_offset + zone->dev_start +
+                tmp_dev->data_offset;
         /*
          * Let the main block layer submit the IO and resolve recursion:
          */
@@ -485,31 +500,35 @@ bad_map:
         return 0;
 }
 
-static void raid0_status (struct seq_file *seq, mddev_t *mddev)
+static void raid0_status(struct seq_file *seq, mddev_t *mddev)
 {
 #undef MD_DEBUG
 #ifdef MD_DEBUG
         int j, k, h;
         char b[BDEVNAME_SIZE];
-        raid0_conf_t *conf = mddev_to_conf(mddev);
+        raid0_conf_t *conf = mddev->private;
 
+        sector_t zone_size;
+        sector_t zone_start = 0;
         h = 0;
+
         for (j = 0; j < conf->nr_strip_zones; j++) {
                 seq_printf(seq, "      z%d", j);
-                if (conf->hash_table[h] == conf->strip_zone+j)
-                        seq_printf(seq, "(h%d)", h++);
                 seq_printf(seq, "=[");
                 for (k = 0; k < conf->strip_zone[j].nb_dev; k++)
                         seq_printf(seq, "%s/", bdevname(
-                                conf->strip_zone[j].dev[k]->bdev,b));
-
-                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].sectors);
+                                conf->devlist[j*mddev->raid_disks + k]
+                                                ->bdev, b));
+
+                zone_size  = conf->strip_zone[j].zone_end - zone_start;
+                seq_printf(seq, "] ze=%lld ds=%lld s=%lld\n",
+                        (unsigned long long)zone_start>>1,
+                        (unsigned long long)conf->strip_zone[j].dev_start>>1,
+                        (unsigned long long)zone_size>>1);
+                zone_start = conf->strip_zone[j].zone_end;
         }
 #endif
-        seq_printf(seq, " %dk chunks", mddev->chunk_size/1024);
+        seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2);
         return;
 }