Re: [PATCH RFC] btrfs: change commit txn to end txn in subvol_setflags ioctl

[Josef Bacik <josef@toxicpanda.com>]

On 8/4/20 1:55 PM, Boris Burkov wrote:
> Currently, btrfs_ioctl_subvol_setflags forces a btrfs_commit_transaction
> while holding subvol_sem. As a result, we have seen workloads where
> calling `btrfs property set -ts <subvol> ro false` hangs waiting for a
> legitimately slow commit. This gets even worse if the workload tries to
> set flags on multiple subvolumes and the ioctls pile up on subvol_sem.
> 
> Change the commit to a btrfs_end_transaction so that the ioctl can
> return in a timely fashion and piggy back on a later commit.
> 
> Signed-off-by: Boris Burkov <boris@bur.io>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

I think we follow up with a btrfs-progs patch to make syncing an option with 
setflags (or hell do it by default and make the option to not sync).  Having the 
commit here was arbitrary and not needed.  Thanks,

Josef