opensolaris man page for getrbuf

getrbuf(9F)						   Kernel Functions for Drivers 					       getrbuf(9F)

NAME
       getrbuf - get a raw buffer header

SYNOPSIS
       #include <sys/buf.h>
       #include <sys/kmem.h>
       #include <sys/ddi.h>

       struct buf *getrbuf(int sleepflag);

INTERFACE LEVEL
       Architecture independent level 1 (DDI/DKI).

PARAMETERS
       sleepflag    Indicates whether driver should sleep for free space.

DESCRIPTION
       The  getrbuf()  function  allocates the space for a buffer header to the caller. It is used in cases where a block driver is performing raw
       (character interface) I/O and needs to set up a buffer header that is not associated with the buffer cache.

       The getrbuf() function calls kmem_alloc(9F) to perform the memory allocation. kmem_alloc()requires the information included in  the  sleep-
       flag  argument.	If  sleepflag is set to KM_SLEEP, the driver may sleep until the space is freed up. If sleepflag is set to KM_NOSLEEP, the
       driver will not sleep.  In either case, a pointer to the allocated space is returned or NULL to indicate that no space was available.

RETURN VALUES
       The getrbuf() function returns a pointer to the allocated buffer header, or NULL if no space is available.

CONTEXT
       The getrbuf() function can be called from user, interrupt, or kernel context. (Drivers must not allow getrbuf() to sleep if called from	an
       interrupt routine.)

SEE ALSO
       bioinit(9F), freerbuf(9F), kmem_alloc(9F), kmem_free(9F)

       Writing Device Drivers

SunOS 5.11							    16 Jan 2006 						       getrbuf(9F)