Man page 9 : blk_queue_end_tag

blk_queue_end_tag - end tag operations for a request

void blk_queue_end_tag(struct request_queue *  q , struct request *  rq );

q
    the request queue for the device

rq
    the request that has completed

Typically called when end_that_request_first returns 0, meaning all transfers have been done for a request. ItAqs important to call this function before end_that_request_last, as that will put the request back on the free list thus corrupting the internal tag list.

queue lock must be held.