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 <kilob...@angband.pl> --- 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? 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 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html