From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:21704 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933558AbdCHB3c (ORCPT ); Tue, 7 Mar 2017 20:29:32 -0500 Date: Tue, 7 Mar 2017 17:27:50 -0800 From: Liu Bo To: Adam Borowski Cc: Chris Mason , Josef Bacik , David Sterba , linux-btrfs@vger.kernel.org Subject: Re: [PATCH v2] btrfs: fix a bogus warning when converting only data or metadata Message-ID: <20170308012750.GL12408@lim.localdomain> Reply-To: bo.li.liu@oracle.com References: <20170307203406.GC12408@lim.localdomain> <20170307223444.7526-1-kilobyte@angband.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20170307223444.7526-1-kilobyte@angband.pl> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Tue, Mar 07, 2017 at 11:34:44PM +0100, Adam Borowski wrote: > If your filesystem has, eg, data:raid0 metadata:raid1, and you run "btrfs > balance -dconvert=raid1", the meta.target field will be uninitialized. > That's otherwise ok, as it's unused except for this warning. > > Thus, let's use the existing set of raid levels for the comparison. > > As a side effect, non-convert balances will now nag about data>metadata. > > Signed-off-by: Adam Borowski > --- > To reproduce: > dd if=/dev/zero bs=1048576 count=1 seek=4095 of=ra > dd if=/dev/zero bs=1048576 count=1 seek=4095 of=rb > mkfs.btrfs ra rb # defaults to -draid0 -mraid1 > losetup -f ra > losetup -f rb > mount /dev/loop0 /mnt/vol1 > btrfs balance start -dconvert=raid1 /mnt/vol1 > > > On Tue, Mar 07, 2017 at 12:34:07PM -0800, Liu Bo wrote: > > This looks good, but this also brings another side effect, @bctl would > > also be kept in balance_item which will be used to resume balance in > > case of crash, so it may see a different bctl->meta.target. > > > > So would you please use local varibles for meta.target and data.target? > > Okay. > > I'm not sure why storing a bogus value that came from userspace and was > uninitialized there (0 in normal use) would be better, but here we go: > v2 doesn't overwrite what we got anymore. > > Unrelated: I wonder if the profiles in the warning message shouldn't be > printk'ed as words (akin to ebce0e01), but we don't have a function to do > that, have we? > We don't have it in kernel, but in progs I believe. For this patch, Reviewed-by: Liu Bo Thanks, -liubo > > Meow! > > fs/btrfs/volumes.c | 12 +++++++++--- > 1 file changed, 9 insertions(+), 3 deletions(-) > > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index 3645af2749f8..987f395ddec5 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -3750,6 +3750,7 @@ int btrfs_balance(struct btrfs_balance_control *bctl, > struct btrfs_ioctl_balance_args *bargs) > { > struct btrfs_fs_info *fs_info = bctl->fs_info; > + __u64 meta_target, data_target; > u64 allowed; > int mixed = 0; > int ret; > @@ -3846,11 +3847,16 @@ int btrfs_balance(struct btrfs_balance_control *bctl, > } > } while (read_seqretry(&fs_info->profiles_lock, seq)); > > - if (btrfs_get_num_tolerated_disk_barrier_failures(bctl->meta.target) < > - btrfs_get_num_tolerated_disk_barrier_failures(bctl->data.target)) { > + /* if we're not converting, the target field is uninitialized */ > + meta_target = (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) ? > + bctl->meta.target : fs_info->avail_metadata_alloc_bits; > + data_target = (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) ? > + bctl->data.target : fs_info->avail_data_alloc_bits; > + if (btrfs_get_num_tolerated_disk_barrier_failures(meta_target) < > + btrfs_get_num_tolerated_disk_barrier_failures(data_target)) { > btrfs_warn(fs_info, > "metadata profile 0x%llx has lower redundancy than data profile 0x%llx", > - bctl->meta.target, bctl->data.target); > + meta_target, data_target); > } > > ret = insert_balance_item(fs_info, bctl); > -- > 2.11.0 >