From 9b3f68b90674419add8be1c0aa740dcdf04f44cc Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Fri, 18 Apr 2008 10:29:51 -0400 Subject: [PATCH] Btrfs: Calculate appropriate chunk sizes for both small and large filesystems Signed-off-by: Chris Mason --- fs/btrfs/volumes.c | 68 +++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 61 insertions(+), 7 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 93aa36e2436e..e3ddd7fb8edd 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -627,6 +627,27 @@ int btrfs_add_system_chunk(struct btrfs_trans_handle *trans, return 0; } +static u64 div_factor(u64 num, int factor) +{ + if (factor == 10) + return num; + num *= factor; + do_div(num, 10); + return num; +} + +static u64 chunk_bytes_by_type(u64 type, u64 calc_size, int num_stripes, + int sub_stripes) +{ + if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP)) + return calc_size; + else if (type & BTRFS_BLOCK_GROUP_RAID10) + return calc_size * (num_stripes / sub_stripes); + else + return calc_size * num_stripes; +} + + int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root, u64 *start, u64 *num_bytes, u64 type) @@ -643,11 +664,14 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, struct extent_map_tree *em_tree; struct map_lookup *map; struct extent_map *em; + int min_chunk_size = 8 * 1024 * 1024; u64 physical; u64 calc_size = 1024 * 1024 * 1024; - u64 min_free = calc_size; + u64 max_chunk_size = calc_size; + u64 min_free; u64 avail; u64 max_avail = 0; + u64 percent_max; int num_stripes = 1; int sub_stripes = 0; int looped = 0; @@ -666,6 +690,8 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, if (type & (BTRFS_BLOCK_GROUP_RAID1)) { num_stripes = min_t(u64, 2, btrfs_super_num_devices(&info->super_copy)); + if (num_stripes < 2) + return -ENOSPC; } if (type & (BTRFS_BLOCK_GROUP_RAID10)) { num_stripes = btrfs_super_num_devices(&info->super_copy); @@ -674,13 +700,45 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, num_stripes &= ~(u32)1; sub_stripes = 2; } + + if (type & BTRFS_BLOCK_GROUP_DATA) { + max_chunk_size = 10 * calc_size; + min_chunk_size = 256 * 1024 * 1024; + } else if (type & BTRFS_BLOCK_GROUP_METADATA) { + max_chunk_size = 4 * calc_size; + min_chunk_size = 64 * 1024 * 1024; + } else { + min_chunk_size = 32 * 1024 * 1024; + } + + /* we don't want a chunk larger than 10% of the FS */ + percent_max = div_factor(btrfs_super_total_bytes(&info->super_copy), 1); + max_chunk_size = min(percent_max, max_chunk_size); + + if (calc_size * num_stripes > max_chunk_size) { + calc_size = max_chunk_size; + do_div(calc_size, num_stripes); + do_div(calc_size, stripe_len); + calc_size *= stripe_len; + } + /* we don't want tiny stripes */ + *num_bytes = chunk_bytes_by_type(type, calc_size, + num_stripes, sub_stripes); + calc_size = max_t(u64, chunk_bytes_by_type(type, min_chunk_size, + num_stripes, sub_stripes), calc_size); + again: + do_div(calc_size, stripe_len); + calc_size *= stripe_len; + INIT_LIST_HEAD(&private_devs); cur = dev_list->next; index = 0; if (type & BTRFS_BLOCK_GROUP_DUP) min_free = calc_size * 2; + else + min_free = calc_size; /* build a private list of devices we will allocate from */ while(index < num_stripes) { @@ -727,13 +785,9 @@ again: } stripes = &chunk->stripe; + *num_bytes = chunk_bytes_by_type(type, calc_size, + num_stripes, sub_stripes); - 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; index = 0; printk("new chunk type %Lu start %Lu size %Lu\n", type, key.offset, *num_bytes); -- 2.30.2