The Linux Manuals (man pages) document is an important part of Linux documents. Linux Manuals are organized as several sections. Each section has a group of commands for a specific area in Linux usage, administration or development.
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 +…
blk_add_trace_bio_remap – Add a trace for a bio-remap operation Synopsis void blk_add_trace_bio_remap(void *ignore, struct request_queue *q, struct bio *bio, dev_t dev, sector_t from); Arguments ignore trace callback data parameter (not used) q queue the io is for bio the source bio dev target device from source sector Description Device mapper or raid target sometimes need…
blk_add_trace_bio – Add a trace for a bio oriented action Synopsis void blk_add_trace_bio(struct request_queue *q, struct bio *bio, u32 what, int error); Arguments q queue the io is for bio the source bio what the action error error, if any Description Records an action against a bio. Will log the bio offset + size. Copyright
blk_add_request_payload – add a payload to a request Synopsis void blk_add_request_payload(struct request *rq, struct page *page, int offset, unsigned int len); Arguments rq request to update page page backing the payload offset offset in page len length of the payload. Description This allows to later add a payload to an already submitted request by a…
bitmap_to_u32array – copy the contents of bitmap to a u32 array of bits Synopsis unsigned int bitmap_to_u32array(u32 *buf, unsigned int nwords, const unsigned long *bitmap, unsigned int nbits); Arguments buf array of u32 (in host byte order), the dest bitmap, non NULL nwords number of u32 words in buf bitmap array of unsigned longs, the…
bitmap_remap – Apply map defined by a pair of bitmaps to another bitmap Synopsis void bitmap_remap(unsigned long *dst, const unsigned long *src, const unsigned long *old, const unsigned long *new, unsigned int nbits); Arguments dst remapped result src subset to be remapped old defines domain of map new defines range of map nbits number of…
bitmap_release_region – release allocated bitmap region Synopsis void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order); Arguments bitmap array of unsigned longs corresponding to the bitmap pos beginning of bit region to release order region size (log base 2 of number of bits) to release Description This is the complement to __bitmap_find_free_region and releases the…