Manual Pages for UNIX Operating System command usage for man getrbuf

Kernel Functions for Drivers                          getrbuf(9F)



NAME
     getrbuf - get a raw buffer header

SYNOPSIS
     #include 
     #include 
     #include 



     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 sleepflag 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          Last change: 16 Jan 2006                    1