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path: root/drivers/md/raid0.c
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Diffstat (limited to 'drivers/md/raid0.c')
-rw-r--r--drivers/md/raid0.c62
1 files changed, 54 insertions, 8 deletions
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index f8ee9a95e25d..d1ac73fcd852 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -270,6 +270,18 @@ static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf)
goto abort;
}
+ if (conf->layout == RAID0_ORIG_LAYOUT) {
+ for (i = 1; i < conf->nr_strip_zones; i++) {
+ sector_t first_sector = conf->strip_zone[i-1].zone_end;
+
+ sector_div(first_sector, mddev->chunk_sectors);
+ zone = conf->strip_zone + i;
+ /* disk_shift is first disk index used in the zone */
+ zone->disk_shift = sector_div(first_sector,
+ zone->nb_dev);
+ }
+ }
+
pr_debug("md/raid0:%s: done.\n", mdname(mddev));
*private_conf = conf;
@@ -431,6 +443,20 @@ exit_acct_set:
return ret;
}
+/*
+ * Convert disk_index to the disk order in which it is read/written.
+ * For example, if we have 4 disks, they are numbered 0,1,2,3. If we
+ * write the disks starting at disk 3, then the read/write order would
+ * be disk 3, then 0, then 1, and then disk 2 and we want map_disk_shift()
+ * to map the disks as follows 0,1,2,3 => 1,2,3,0. So disk 0 would map
+ * to 1, 1 to 2, 2 to 3, and 3 to 0. That way we can compare disks in
+ * that 'output' space to understand the read/write disk ordering.
+ */
+static int map_disk_shift(int disk_index, int num_disks, int disk_shift)
+{
+ return ((disk_index + num_disks - disk_shift) % num_disks);
+}
+
static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
{
struct r0conf *conf = mddev->private;
@@ -444,7 +470,9 @@ static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
sector_t end_disk_offset;
unsigned int end_disk_index;
unsigned int disk;
+ sector_t orig_start, orig_end;
+ orig_start = start;
zone = find_zone(conf, &start);
if (bio_end_sector(bio) > zone->zone_end) {
@@ -458,6 +486,7 @@ static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
} else
end = bio_end_sector(bio);
+ orig_end = end;
if (zone != conf->strip_zone)
end = end - zone[-1].zone_end;
@@ -469,13 +498,26 @@ static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
last_stripe_index = end;
sector_div(last_stripe_index, stripe_size);
- start_disk_index = (int)(start - first_stripe_index * stripe_size) /
- mddev->chunk_sectors;
+ /* In the first zone the original and alternate layouts are the same */
+ if ((conf->layout == RAID0_ORIG_LAYOUT) && (zone != conf->strip_zone)) {
+ sector_div(orig_start, mddev->chunk_sectors);
+ start_disk_index = sector_div(orig_start, zone->nb_dev);
+ start_disk_index = map_disk_shift(start_disk_index,
+ zone->nb_dev,
+ zone->disk_shift);
+ sector_div(orig_end, mddev->chunk_sectors);
+ end_disk_index = sector_div(orig_end, zone->nb_dev);
+ end_disk_index = map_disk_shift(end_disk_index,
+ zone->nb_dev, zone->disk_shift);
+ } else {
+ start_disk_index = (int)(start - first_stripe_index * stripe_size) /
+ mddev->chunk_sectors;
+ end_disk_index = (int)(end - last_stripe_index * stripe_size) /
+ mddev->chunk_sectors;
+ }
start_disk_offset = ((int)(start - first_stripe_index * stripe_size) %
mddev->chunk_sectors) +
first_stripe_index * mddev->chunk_sectors;
- end_disk_index = (int)(end - last_stripe_index * stripe_size) /
- mddev->chunk_sectors;
end_disk_offset = ((int)(end - last_stripe_index * stripe_size) %
mddev->chunk_sectors) +
last_stripe_index * mddev->chunk_sectors;
@@ -483,18 +525,22 @@ static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
for (disk = 0; disk < zone->nb_dev; disk++) {
sector_t dev_start, dev_end;
struct md_rdev *rdev;
+ int compare_disk;
+
+ compare_disk = map_disk_shift(disk, zone->nb_dev,
+ zone->disk_shift);
- if (disk < start_disk_index)
+ if (compare_disk < start_disk_index)
dev_start = (first_stripe_index + 1) *
mddev->chunk_sectors;
- else if (disk > start_disk_index)
+ else if (compare_disk > start_disk_index)
dev_start = first_stripe_index * mddev->chunk_sectors;
else
dev_start = start_disk_offset;
- if (disk < end_disk_index)
+ if (compare_disk < end_disk_index)
dev_end = (last_stripe_index + 1) * mddev->chunk_sectors;
- else if (disk > end_disk_index)
+ else if (compare_disk > end_disk_index)
dev_end = last_stripe_index * mddev->chunk_sectors;
else
dev_end = end_disk_offset;