From: NeilBrown There are two errors that can lead to recovery problems with raid10 when used in 'far' more (not the default). Due to a '>' instead of '>=' the wrong block is located which would result in garbage being written to some random location, quite possible outside the range of the device, causing the newly reconstructed device to fail. The device size calculation had some rounding errors (it didn't round when it should) and so recovery would go a few blocks too far which would again cause a write to a random block address and probably a device error. The code for working with device sizes was fairly confused and spread out, so this has been tided up a bit. Signed-off-by: Neil Brown Signed-off-by: Greg Kroah-Hartman --- drivers/md/raid10.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+), 18 deletions(-) --- linux-2.6.20.1.orig/drivers/md/raid10.c +++ linux-2.6.20.1/drivers/md/raid10.c @@ -429,7 +429,7 @@ static sector_t raid10_find_virt(conf_t if (dev < 0) dev += conf->raid_disks; } else { - while (sector > conf->stride) { + while (sector >= conf->stride) { sector -= conf->stride; if (dev < conf->near_copies) dev += conf->raid_disks - conf->near_copies; @@ -1801,6 +1801,7 @@ static sector_t sync_request(mddev_t *md for (k=0; kcopies; k++) if (r10_bio->devs[k].devnum == i) break; + BUG_ON(k == conf->copies); bio = r10_bio->devs[1].bio; bio->bi_next = biolist; biolist = bio; @@ -2021,19 +2022,30 @@ static int run(mddev_t *mddev) if (!conf->tmppage) goto out_free_conf; + conf->mddev = mddev; + conf->raid_disks = mddev->raid_disks; conf->near_copies = nc; conf->far_copies = fc; conf->copies = nc*fc; conf->far_offset = fo; conf->chunk_mask = (sector_t)(mddev->chunk_size>>9)-1; conf->chunk_shift = ffz(~mddev->chunk_size) - 9; + size = mddev->size >> (conf->chunk_shift-1); + sector_div(size, fc); + size = size * conf->raid_disks; + sector_div(size, nc); + /* 'size' is now the number of chunks in the array */ + /* calculate "used chunks per device" in 'stride' */ + stride = size * conf->copies; + sector_div(stride, conf->raid_disks); + mddev->size = stride << (conf->chunk_shift-1); + if (fo) - conf->stride = 1 << conf->chunk_shift; - else { - stride = mddev->size >> (conf->chunk_shift-1); + stride = 1; + else sector_div(stride, fc); - conf->stride = stride << conf->chunk_shift; - } + conf->stride = stride << conf->chunk_shift; + conf->r10bio_pool = mempool_create(NR_RAID10_BIOS, r10bio_pool_alloc, r10bio_pool_free, conf); if (!conf->r10bio_pool) { @@ -2063,8 +2075,6 @@ static int run(mddev_t *mddev) disk->head_position = 0; } - conf->raid_disks = mddev->raid_disks; - conf->mddev = mddev; spin_lock_init(&conf->device_lock); INIT_LIST_HEAD(&conf->retry_list); @@ -2106,16 +2116,8 @@ static int run(mddev_t *mddev) /* * Ok, everything is just fine now */ - if (conf->far_offset) { - size = mddev->size >> (conf->chunk_shift-1); - size *= conf->raid_disks; - size <<= conf->chunk_shift; - sector_div(size, conf->far_copies); - } else - size = conf->stride * conf->raid_disks; - sector_div(size, conf->near_copies); - mddev->array_size = size/2; - mddev->resync_max_sectors = size; + mddev->array_size = size << (conf->chunk_shift-1); + mddev->resync_max_sectors = size << conf->chunk_shift; mddev->queue->unplug_fn = raid10_unplug; mddev->queue->issue_flush_fn = raid10_issue_flush; -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/