UNIX for Advanced & Expert Users

mkfs.xfs -r rtdev=/dev/hda5 /dev/hda8

mount -t xfs -o rtdev=/dev/hda5 /dev/hda8 /xfs

       The realtime section is used to  store  the  data  of  realtime  files.
       These  files had an attribute bit set through xfsctl(3) after file cre-
       ation, before any data was written to the file.  The  realtime  section
       is  divided  into  a  number  of  extents  of  fixed size (specified at
       mkfs.xfs(8) time).  Each file in the realtime  section  has  an  extent
       size that is a multiple of the realtime section extent size.

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#include <xfs/xfs.h>

#define DIE(X)  do { perror(X); goto EXIT_FAIL; } while(0)

int main(void)
{
        struct fsxattr attrib;
        const char *xfs_filename="/opt/public/Read Me.txt";
        int fd=open(xfs_filename, O_RDONLY);

        if(fd < 0)
                DIE("Couldn't open file");
        // Get extended attributes for file
        if(xfsctl(xfs_filename, fd, XFS_IOC_FSGETXATTR, &attrib) != 0)
                DIE("Couldn't read attributes");

        // Set the realtime status bit
        attrib.fsx_xflags |= XFS_XFLAG_REALTIME;

        // Attempt to set these attributes on the file
        if(xfsctl(xfs_filename, fd, XFS_IOC_FSSETXATTR, &attrib) != 0)
                DIE("Couldn't set attributes");

        close(fd);
        return(0);
EXIT_FAIL:
        if(fd >= 0) close(fd);
        return(1);
}