blk_init_tags – initialize the tag info for an external tag map Synopsis struct blk_queue_tag *blk_init_tags(int depth, int alloc_policy); Arguments depth the maximum queue depth supported alloc_policy tag allocation policy Copyright
blk_init_queue – prepare a request queue for use with a block device Synopsis struct request_queue *blk_init_queue(request_fn_proc *rfn, spinlock_t *lock); Arguments rfn The function to be called to process requests that have been placed on the queue. lock Request queue spin lock Description If a block device wishes to use the standard request handling procedures, which…
blk_get_backing_dev_info – get the address of a queue’s backing_dev_info Synopsis struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); Arguments bdev device Description Locates the passed device’s request queue and returns the address of its backing_dev_info. This function can only be called if bdev is opened and the return value is never NULL. Copyright
blk_free_tags – release a given set of tag maintenance info Synopsis void blk_free_tags(struct blk_queue_tag *bqt); Arguments bqt the tag map to free Description Drop the reference count on bqt and frees it when the last reference is dropped. Copyright
blk_free_devt – free a dev_t Synopsis void blk_free_devt(dev_t devt); Arguments devt dev_t to free Description Free devt which was allocated using blk_alloc_devt. Context Might sleep. Copyright
blk_fetch_request – fetch a request from a request queue Synopsis struct request *blk_fetch_request(struct request_queue *q); Arguments q request queue to fetch a request from Description Return the request at the top of q. The request is started on return and LLD can start processing it immediately. Return Pointer to the request at the top of…
blk_execute_rq_nowait – insert a request into queue for execution Synopsis void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk, struct request *rq, int at_head, rq_end_io_fn *done); Arguments q queue to insert the request in bd_disk matching gendisk rq request to insert at_head insert request at head or tail of queue done I/O completion handler Description Insert a…
blk_execute_rq – insert a request into queue for execution Synopsis int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk, struct request *rq, int at_head); Arguments q queue to insert the request in bd_disk matching gendisk rq request to insert at_head insert request at head or tail of queue Description Insert a fully prepared request at the back…
blk_end_request_err – Finish a request till the next failure boundary. Synopsis bool blk_end_request_err(struct request * rq, int error); Arguments rq the request to finish till the next failure boundary for error must be negative errno Description Complete rq till the next failure boundary. Return false – we are done with this request true – still buffers pending for…
blk_end_request_cur – Helper function to finish the current request chunk. Synopsis bool blk_end_request_cur(struct request * rq, int error); Arguments rq the request to finish the current chunk for error 0 for success, < 0 for error Description Complete the current consecutively mapped chunk from rq. Return false – we are done with this request true – still buffers…
blk_end_request_all – Helper function for drives to finish the request. Synopsis void blk_end_request_all(struct request *rq, int error); Arguments rq the request to finish error 0 for success, < 0 for error Description Completely finish rq. Copyright
blk_end_request – Helper function for drivers to complete the request. Synopsis bool blk_end_request(struct request * rq, int error, unsigned int nr_bytes); Arguments rq the request being processed error 0 for success, < 0 for error nr_bytes number of bytes to complete Description Ends I/O on a number of bytes attached to rq. If rq has leftover, sets it up…
blk_end_bidi_request – Complete a bidi request Synopsis bool blk_end_bidi_request(struct request * rq, int error, unsigned int nr_bytes, unsigned int bidi_bytes); Arguments rq the request to complete error 0 for success, < 0 for error nr_bytes number of bytes to complete rq bidi_bytes number of bytes to complete rq->next_rq Description Ends I/O on a number of bytes attached to rq and…
blk_delay_queue – restart queueing after defined interval Synopsis void blk_delay_queue(struct request_queue *q, unsigned long msecs); Arguments q The struct request_queue in question msecs Delay in msecs Description Sometimes queueing needs to be postponed for a little while, to allow resources to come back. This function will make sure that queueing is restarted around the specified…
blk_cloned_rq_check_limits – Helper function to check a cloned request for new the queue limits Synopsis int blk_cloned_rq_check_limits(struct request_queue *q, struct request *rq); Arguments q the queue rq the request being checked Description rq may have been made based on weaker limitations of upper-level queues in request stacking drivers, and it may violate the limitation of…
blk_cleanup_queue – shutdown a request queue Synopsis void blk_cleanup_queue(struct request_queue *q); Arguments q request queue to shutdown Description Mark q DYING, drain all pending requests, mark q DEAD, destroy and put it. All future requests will be failed immediately with -ENODEV. Copyright
blk_attempt_plug_merge – try to merge with current‘s plugged list Synopsis bool blk_attempt_plug_merge(struct request_queue * q, struct bio * bio, unsigned int * request_count, struct request ** same_queue_rq); Arguments q request_queue new bio is being queued at bio new bio being queued request_count out parameter for number of traversed plugged requests same_queue_rq pointer to struct request that gets filled in when another request associated…
blk_alloc_devt – allocate a dev_t for a partition Synopsis int blk_alloc_devt(struct hd_struct *part, dev_t *devt); Arguments part partition to allocate dev_t for devt out parameter for resulting dev_t Description Allocate a dev_t for block device. Return 0 on success, allocated dev_t is returned in *devt. -errno on failure. Context Might sleep. Copyright
blk_add_trace_rq_remap – Add a trace for a request-remap operation Synopsis void blk_add_trace_rq_remap(void *ignore, struct request_queue *q, struct request *rq, dev_t dev, sector_t from); Arguments ignore trace callback data parameter (not used) q queue the io is for rq the source request dev target device from source sector Description Device mapper remaps request to other devices….
blk_add_trace_rq – Add a trace for a request oriented action Synopsis void blk_add_trace_rq(struct request_queue *q, struct request *rq, unsigned int nr_bytes, u32 what); Arguments q queue the io is for rq the source request nr_bytes number of completed bytes what the action Description Records an action against a request. Will log the bio offset +…