centos man page for get_request

GET_REQUEST(9)							   Block Devices						    GET_REQUEST(9)

NAME
       get_request - get a free request

SYNOPSIS
       struct request * get_request(struct request_queue * q, int rw_flags, struct bio * bio, gfp_t gfp_mask);

ARGUMENTS
       q
	   request_queue to allocate request from

       rw_flags
	   RW and SYNC flags

       bio
	   bio to allocate request for (can be NULL)

       gfp_mask
	   allocation mask

DESCRIPTION
       Get a free request from q. If __GFP_WAIT is set in gfp_mask, this function keeps retrying under memory pressure and fails iff q is dead.

       Must be callled with q->queue_lock held and, Returns NULL on failure, with q->queue_lock held. Returns !NULL on success, with q->queue_lock
       *not held*.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014							    GET_REQUEST(9)