Re: [PATCH v2] btrfs-progs: there is devid 0 when replace is running

[Anand Jain <Anand.Jain@oracle.com>]

kindly ignore this patch. Though it correct that we need to
start from devid 0 to scan. But the individual scan is broken
well before this patch. So to fix all together a patch bundle
is sent to the mailing list including this

Thanks Anand


On 02/04/14 04:33 PM, Anand Jain wrote:
> During disk replacement a new disk is temporarily
> added to the fs devlist with devid 0 and fs num_device is
> incremented by 1. However when progs reads the devlist it
> fail to obtain details of devid 0 because it doesn't query
> devid 0 at all.
>
> reproducer:
>
>   btrfs rep start /dev/sdb /dev/sdf /btrfs
>   btrfs fi show
>   Label: none  uuid: f8fb9819-16c8-47b7-b62f-0ff90f8c56cd
>          Total devices 3 FS bytes used 1.94GiB
>          devid    1 size 1.10GiB used 1.10GiB path /dev/sdb
>          devid    2 size 1.10GiB used 1.08GiB path /dev/sdc
>          devid    0 size 0.00 used 0.00 path
>
>    this patch will make it proper by querying devid 0.
>
>   btrfs repl start /dev/sdb /dev/sdf /btrfs
>   btrfs fi show /btrfs
>   Label: none  uuid: f8fb9819-16c8-47b7-b62f-0ff90f8c56cd
>          Total devices 3 FS bytes used 1.94GiB
>          devid    0 size 1.10GiB used 1.10GiB path /dev/sdf
>          devid    1 size 1.10GiB used 1.10GiB path /dev/sdb
>          devid    2 size 1.10GiB used 1.08GiB path /dev/sdc
>
>   Its fine to query devid 0 when there is no replace
>   activity as well, because we just skip the error ENODEV
>
>   btrfs fi show /btrfs
>   Label: none  uuid: f8fb9819-16c8-47b7-b62f-0ff90f8c56cd
>          Total devices 2 FS bytes used 1.94GiB
>          devid    1 size 1.10GiB used 1.10GiB path /dev/sdf
>          devid    2 size 1.10GiB used 1.08GiB path /dev/sdc
> ---
>
>   v2: fix commit message
>
>   utils.c |    2 +-
>   1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/utils.c b/utils.c
> index de513b6..a045ffd 100644
> --- a/utils.c
> +++ b/utils.c
> @@ -1696,7 +1696,7 @@ int get_fs_info(char *path, struct btrfs_ioctl_fs_info_args *fi_args,
>   		goto out;
>   	}
>
> -	for (; i <= fi_args->max_id; ++i) {
> +	for (i = 0; i <= fi_args->max_id; ++i) {
>   		BUG_ON(ndevs >= fi_args->num_devices);
>   		ret = get_device_info(fd, i, &di_args[ndevs]);
>   		if (ret == -ENODEV)
>