Commit 2f081088 authored Jan 09, 2015 by Shaohua Li Committed by Chris Mason Feb 02, 2015

btrfs: delete chunk allocation attemp when setting block group ro



Below test will fail currently:
      mkfs.ext4 -F /dev/sda
      btrfs-convert /dev/sda
      mount /dev/sda /mnt
      btrfs device add -f /dev/sdb /mnt
      btrfs balance start -v -dconvert=raid1 -mconvert=raid1 /mnt

The reason is there are some block groups with usage 0, but the whole
disk hasn't free space to allocate new chunk, so we even can't set such
block group readonly. This patch deletes the chunk allocation when
setting block group ro. For META, we already have reserve. But for
SYSTEM, we don't have, so the check_system_chunk is still required.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>

parent 289454ad

fs/btrfs/extent-tree.c

+5 −8

Original line number	Diff line number	Diff line
		@@ -8482,14 +8482,6 @@ int btrfs_set_block_group_ro(struct btrfs_root *root,
		if (IS_ERR(trans))
		return PTR_ERR(trans);

		alloc_flags = update_block_group_flags(root, cache->flags);
		if (alloc_flags != cache->flags) {
		ret = do_chunk_alloc(trans, root, alloc_flags,
		CHUNK_ALLOC_FORCE);
		if (ret < 0)
		goto out;
		}

		ret = set_block_group_ro(cache, 0);
		if (!ret)
		goto out;
		@@ -8500,6 +8492,11 @@ int btrfs_set_block_group_ro(struct btrfs_root *root,
		goto out;
		ret = set_block_group_ro(cache, 0);
		out:
		if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
		alloc_flags = update_block_group_flags(root, cache->flags);
		check_system_chunk(trans, root, alloc_flags);
		}

		btrfs_end_transaction(trans, root);
		return ret;
		}

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