Re: [PATCH 5/5] Btrfs: scan all the devices and build the fs device list by btrfs's self

[Goffredo Baroncelli <kreijack@inwind.it>]

On 09/03/2014 03:36 PM, Miao Xie wrote:
> The original code need scan the devices and build the fs device list by the user
> tool by udev or users' selves. It is flexible. But if someone re-install the
> filesystem module, and forget to scan the devices by himself, or we plug some
> devices with btrfs, but udev thread is blocked and doesn't register the disk
> into btrfs in time, the filesystem would report that "can not open some device"
> when mounting the filesystem, it was uncomfortable, this patch fixes this problem
> by scanning all the devices if we find the number of devices is not right when
> we mount the filesystem.
> 
> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
[....]
> +
> +void btrfs_scan_all_devices(void *holder)
> +{
> +	struct class_dev_iter iter;
> +	struct device *dev;
> +	struct gendisk *disk;
> +
> +	mutex_lock(&uuid_mutex);
> +	class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
> +	while ((dev = class_dev_iter_next(&iter))) {
> +		disk = dev_to_disk(dev);
> +
> +		if (!get_capacity(disk) ||
> +		    (!disk_max_parts(disk) &&
> +		     (disk->flags & GENHD_FL_REMOVABLE)))
                                    ^^^^^^^^^^^^^^^^^^
> +			continue;
> +
> +		if (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
> +			continue;


Hi, could you elaborate why a removable disk should be not scan-ned ? How
a removble usb disk is classified ?

Thanks.
G.Baroncelli

[...]


-- 
gpg @keyserver.linux.it: Goffredo Baroncelli (kreijackATinwind.it>
Key fingerprint BBF5 1610 0B64 DAC6 5F7D  17B2 0EDA 9B37 8B82 E0B5