[parted-devel] some issues with ped_disk_commit_to_os()

[Bart Hakvoort]

Hi people,

As many of you probably know gparted uses libparted to create partitions
and CLI tools to create filesystems on them. While this works quite well
there has been a small problem since the beginning.
Whenever i call ped_disk_commit_to_os() (which in turn will call ioctl(int
fd, BLKRRPART) somewhere in the process) the devicenodes show up after a
small delay. This delay causes the CLItools to throw a 'device not found'
error every now and then. I've tried working with sync() and fsync(), but
without luck so far.
Till now i simply 'solved' this by sleeping a bit after the reread, but
this is not perfect and every now and then someone encounters this. Also i
wonder if there is a better way to solve this?

Below is a small, dirty piece of source that illustrates the problem. It's
only for illustration, so don't run it at home :P

#include <parted/parted.h>

int main()
{
        PedDevice *device = ped_device_get( "/dev/sda" );
        PedDisk *disk = ped_disk_new( device );

        ped_disk_commit_to_os( disk ) ;

        ped_disk_destroy( disk ) ;
        ped_device_destroy( device ) ;

        system( "mke2fs /dev/sda2" ) ; //<-- sometimes /dev/sda2 doesn't
exist yet!!

        return 0 ;
}

This will work most of the time, but sometimes (depending on a lot of
factors) it'll fail. Insights and ideas are appreciated!

thanks,

Bart


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