Re: [PATCH 0/2] provide fsid in sysfs devinfo

[Josef Bacik <josef@toxicpanda.com>]

On Tue, Oct 19, 2021 at 08:22:08AM +0800, Anand Jain wrote:
> btrfs-progs tries to read the fsid from the super-block for a missing
> device and, it fails. It needs to find out if the device is a seed
> device. It does it by comparing the device's fsid with the fsid of the
> mounted filesystem. To help this scenario introduce a new sysfs file to
> read the fsid from the kernel.
>      /sys/fs/btrfs/<fsid>/devinfo/<devid>/fsid
> 
> Patch 1 is a cleanup converts scnprtin()f and snprintf() to sysfs_emit()
> Patch 2 introduces the new sysfs interface as above
> 
> The other implementation choice is to add another parameter to the
> struct btrfs_ioctl_dev_info_args and use BTRFS_IOC_DEV_INFO ioctl. But
> then backward kernel compatibility with the newer btrfs-progs is more
> complicated. If needed, we can add that too.
> 
> Related btrfs-progs patches:
>   btrfs-progs: prepare helper device_is_seed
>   btrfs-progs: read fsid from the sysfs in device_is_seed
> 
> Anand Jain (2):
>   btrfs: sysfs convert scnprintf and snprintf to use sysfs_emit
>   btrfs: sysfs add devinfo/fsid to retrieve fsid from the device
> 
>  fs/btrfs/sysfs.c | 113 +++++++++++++++++++++++++----------------------
>  1 file changed, 60 insertions(+), 53 deletions(-)
> 

You can add

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

to the series.  Thanks,

Josef