On Sun, Apr 19, 2015 at 01:17:05AM -0700, Omar Sandoval wrote: > This reverts commit 2f0810880f082fa8ba66ab2c33b02e4ff9770a5e. > > This tried to fix the following test case: > > 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 > > Before the reverted commit, this test case failed with ENOSPC because > all chunks on the freshly converted filesystem were allocated, although > many were empty. The reverted commit removed an allocation attempt in > btrfs_set_block_group_ro(), but that fix wasn't right. After the > reverted commit, the balance succeeds, but the data/metadata profiles > aren't actually updated: > > # btrfs fi df /mnt > Data, single: total=208.00MiB, used=49.48MiB > System, single: total=32.00MiB, used=4.00KiB > Metadata, single: total=208.00MiB, used=48.00KiB > GlobalReserve, single: total=4.00MiB, used=0.00B > > Indeed, several users reported that this commit caused a regression and > that converting the data and metadata profiles no longer works. This is > because the chunk allocation in question was where we actually allocated > the chunk with the new profile. Not seeing a more obvious fix, let's > just revert this. We can work around the ENOSPC in the original test > case by just issuing a balance to free up the unused block groups before > the conversion, anyways: > > mkfs.ext4 -F /dev/sda > btrfs-convert /dev/sda > mount /dev/sda /mnt > btrfs balance start -v /mnt > btrfs device add -f /dev/sdb /mnt > btrfs balance start -v -dconvert=raid1 -mconvert=raid1 /mnt > > Reported-by: Holger Hoffstätte <holger.hoffstaette@xxxxxxxxxxxxxx> > Cc: Shaohua Li <shli@xxxxxx> > Signed-off-by: Omar Sandoval <osandov@xxxxxxxxxxx> > --- > Holger reported this awhile ago and I haven't seen a proper fix make it > to the ML. I messed around with it for awhile and came up empty, but I > figured I might as well send this in. Applies to v4.0. > > fs/btrfs/extent-tree.c | 13 ++++++++----- > 1 file changed, 8 insertions(+), 5 deletions(-) > Has another fix for this shown up yet? Currently 4.0 and up can't convert between data/metadata profiles, which seems like a pretty major regression. Thanks, -- Omar -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
