On Tue, Jul 20, 2004 at 08:48:24PM +0200, bert hubert wrote: > On Tue, Jul 20, 2004 at 10:27:57AM -0700, Shesha Sreenivasamurthy wrote: > > I am having trouble with O_DIRECT. Trying to read or write from a block > > device partition. > > > > 1. Can O_DIRECT be used on a plain block device partition say > > "/dev/sda11" without having a filesystem on it. > > As fas as I know, yes, but be aware that O_DIRECT requires page aligned > addresses! (an integral of 4096 on most systems). Agreed, and I can tell you it works with raw disk devices. The code we use is: p = malloc (blocksize + PAGE_SIZE); buf = (void *) (( ((long)p) + PAGE_SIZE -1 ) & ~(PAGE_SIZE-1)); Roger. -- ** R.E.Wolff@xxxxxxxxxxxx ** http://www.BitWizard.nl/ ** +31-15-2600998 ** *-- BitWizard writes Linux device drivers for any device you may have! --* **** "Linux is like a wigwam - no windows, no gates, apache inside!" **** -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
