btrfs: fix wrong calculation of stripe size

There are two tiny problem:
- One is When we check the chunk size is greater than the max chunk size or not,
  we should take mirrors into account, but the original code didn't.
- The other is btrfs shouldn't use the size of the residual free space as the
  length of of a dup chunk when doing chunk allocation. It is because the device
  space that a dup chunk needs is twice as large as the chunk size, if we use
  the size of the residual free space as the length of a dup chunk, we can not
  get enough free space. Fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Miao Xie 2011-01-05 10:07:24 +00:00 committed by Chris Mason
parent d52a5b5f1f
commit 1974a3b42d

View file

@ -2177,6 +2177,7 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
int num_stripes = 1;
int min_stripes = 1;
int sub_stripes = 0;
int ncopies = 1;
int looped = 0;
int ret;
int index;
@ -2197,12 +2198,14 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
if (type & (BTRFS_BLOCK_GROUP_DUP)) {
num_stripes = 2;
min_stripes = 2;
ncopies = 2;
}
if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
if (fs_devices->rw_devices < 2)
return -ENOSPC;
num_stripes = 2;
min_stripes = 2;
ncopies = 2;
}
if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
num_stripes = fs_devices->rw_devices;
@ -2210,6 +2213,7 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
return -ENOSPC;
num_stripes &= ~(u32)1;
sub_stripes = 2;
ncopies = 2;
min_stripes = 4;
}
@ -2239,8 +2243,8 @@ again:
map->num_stripes = num_stripes;
}
if (calc_size * num_stripes > max_chunk_size) {
calc_size = max_chunk_size;
if (calc_size * num_stripes > max_chunk_size * ncopies) {
calc_size = max_chunk_size * ncopies;
do_div(calc_size, num_stripes);
do_div(calc_size, stripe_len);
calc_size *= stripe_len;
@ -2321,6 +2325,8 @@ again:
if (!looped && max_avail > 0) {
looped = 1;
calc_size = max_avail;
if (type & BTRFS_BLOCK_GROUP_DUP)
do_div(calc_size, 2);
goto again;
}
kfree(map);