Commit 1974a3b4 authored by Miao Xie's avatar Miao Xie Committed by Chris Mason
Browse files

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: default avatarMiao Xie <miaox@cn.fujitsu.com>
Reviewed-by: default avatarJosef Bacik <josef@redhat.com>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent d52a5b5f

fs/btrfs/volumes.c

+8 −2
Original line number Diff line number Diff line
@@ -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);

CRA Git | Maintained and supported by SUSTech CRA and CCSE