Commit 153c35b6 authored May 19, 2015 by Chris Mason

Btrfs: fix regression in raid level conversion



Commit 2f081088 changed
btrfs_set_block_group_ro to avoid trying to allocate new chunks with the
new raid profile during conversion.  This fixed failures when there was
no space on the drive to allocate a new chunk, but the metadata
reserves were sufficient to continue the conversion.

But this ended up causing a regression when the drive had plenty of
space to allocate new chunks, mostly because reduce_alloc_profile isn't
using the new raid profile.

Fixing btrfs_reduce_alloc_profile is a bigger patch.  For now, do a
partial revert of 2f081088, and don't error out if we hit ENOSPC.

Signed-off-by: Chris Mason <clm@fb.com>
Tested-by: Dave Sterba <dsterba@suse.cz>
Reported-by: Holger Hoffstaette <holger.hoffstaette@googlemail.com>

parent a9629596

fs/btrfs/extent-tree.c

+18 −0

Original line number	Original line	Diff line number	Diff line
	@@ -8829,6 +8829,24 @@ int btrfs_set_block_group_ro(struct btrfs_root *root,
	goto again;		goto again;
	}		}

			/*
			* if we are changing raid levels, try to allocate a corresponding
			* block group with the new raid level.
			*/
			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);
			/*
			* ENOSPC is allowed here, we may have enough space
			* already allocated at the new raid level to
			* carry on
			*/
			if (ret == -ENOSPC)
			ret = 0;
			if (ret < 0)
			goto out;
			}

	ret = set_block_group_ro(cache, 0);		ret = set_block_group_ro(cache, 0);
	if (!ret)		if (!ret)