From 321aecc65671ae8136bd2ca6879b56f0221f8ac8 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Wed, 16 Apr 2008 10:49:51 -0400 Subject: Btrfs: Add RAID10 support Signed-off-by: Chris Mason --- fs/btrfs/volumes.c | 46 +++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 41 insertions(+), 5 deletions(-) (limited to 'fs/btrfs/volumes.c') diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 23ebd95b25e..e6417a573d4 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -33,6 +33,7 @@ struct map_lookup { int stripe_len; int sector_size; int num_stripes; + int sub_stripes; struct btrfs_bio_stripe stripes[]; }; @@ -641,6 +642,7 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, u64 avail; u64 max_avail = 0; int num_stripes = 1; + int sub_stripes = 0; int looped = 0; int ret; int index; @@ -658,6 +660,13 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, num_stripes = min_t(u64, 2, btrfs_super_num_devices(&info->super_copy)); } + if (type & (BTRFS_BLOCK_GROUP_RAID10)) { + num_stripes = btrfs_super_num_devices(&info->super_copy); + if (num_stripes < 4) + return -ENOSPC; + num_stripes &= ~(u32)1; + sub_stripes = 2; + } again: INIT_LIST_HEAD(&private_devs); cur = dev_list->next; @@ -714,6 +723,8 @@ again: if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP)) *num_bytes = calc_size; + else if (type & BTRFS_BLOCK_GROUP_RAID10) + *num_bytes = calc_size * num_stripes / sub_stripes; else *num_bytes = calc_size * num_stripes; @@ -760,12 +771,14 @@ printk("alloc chunk start %Lu size %Lu from dev %Lu type %Lu\n", key.offset, cal btrfs_set_stack_chunk_io_align(chunk, stripe_len); btrfs_set_stack_chunk_io_width(chunk, stripe_len); btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize); + btrfs_set_stack_chunk_sub_stripes(chunk, sub_stripes); map->sector_size = extent_root->sectorsize; map->stripe_len = stripe_len; map->io_align = stripe_len; map->io_width = stripe_len; map->type = type; map->num_stripes = num_stripes; + map->sub_stripes = sub_stripes; ret = btrfs_insert_item(trans, chunk_root, &key, chunk, btrfs_chunk_item_size(num_stripes)); @@ -832,6 +845,8 @@ int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len) map = (struct map_lookup *)em->bdev; if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1)) ret = map->num_stripes; + else if (map->type & BTRFS_BLOCK_GROUP_RAID10) + ret = map->sub_stripes; else ret = 1; free_extent_map(em); @@ -849,6 +864,7 @@ int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw, u64 stripe_offset; u64 stripe_nr; int stripes_allocated = 8; + int stripes_required = 1; int stripe_index; int i; struct btrfs_multi_bio *multi = NULL; @@ -877,10 +893,16 @@ again: mirror_num = 0; /* if our multi bio struct is too small, back off and try again */ - if (multi_ret && (rw & (1 << BIO_RW)) && - stripes_allocated < map->num_stripes && - ((map->type & BTRFS_BLOCK_GROUP_RAID1) || - (map->type & BTRFS_BLOCK_GROUP_DUP))) { + if (rw & (1 << BIO_RW)) { + if (map->type & (BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_DUP)) { + stripes_required = map->num_stripes; + } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { + stripes_required = map->sub_stripes; + } + } + if (multi_ret && rw == WRITE && + stripes_allocated < stripes_required) { stripes_allocated = map->num_stripes; free_extent_map(em); kfree(multi); @@ -900,6 +922,7 @@ again: stripe_offset = offset - stripe_offset; if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID10 | BTRFS_BLOCK_GROUP_DUP)) { /* we limit the length of each bio to what fits in a stripe */ *length = min_t(u64, em->len - offset, @@ -937,6 +960,19 @@ again: multi->num_stripes = map->num_stripes; else if (mirror_num) stripe_index = mirror_num - 1; + } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { + int factor = map->num_stripes / map->sub_stripes; + int orig_stripe_nr = stripe_nr; + + stripe_index = do_div(stripe_nr, factor); + stripe_index *= map->sub_stripes; + + if (rw & (1 << BIO_RW)) + multi->num_stripes = map->sub_stripes; + else if (mirror_num) + stripe_index += mirror_num - 1; + else + stripe_index += orig_stripe_nr % map->sub_stripes; } else { /* * after this do_div call, stripe_nr is the number of stripes @@ -946,7 +982,6 @@ again: stripe_index = do_div(stripe_nr, map->num_stripes); } BUG_ON(stripe_index >= map->num_stripes); - BUG_ON(stripe_index != 0 && multi->num_stripes > 1); for (i = 0; i < multi->num_stripes; i++) { multi->stripes[i].physical = @@ -1120,6 +1155,7 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key, map->sector_size = btrfs_chunk_sector_size(leaf, chunk); map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk); map->type = btrfs_chunk_type(leaf, chunk); + map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk); for (i = 0; i < num_stripes; i++) { map->stripes[i].physical = btrfs_stripe_offset_nr(leaf, chunk, i); -- cgit v1.2.3