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block/blk-core.c
73.7 KB
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/* |
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* Copyright (C) 1991, 1992 Linus Torvalds * Copyright (C) 1994, Karl Keyte: Added support for disk statistics * Elevator latency, (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE * Queue request tables / lock, selectable elevator, Jens Axboe <axboe@suse.de> |
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* kernel-doc documentation started by NeilBrown <neilb@cse.unsw.edu.au> * - July2000 |
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* bio rewrite, highmem i/o, etc, Jens Axboe <axboe@suse.de> - may 2001 */ /* * This handles all read/write requests to block devices */ |
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#include <linux/kernel.h> #include <linux/module.h> #include <linux/backing-dev.h> #include <linux/bio.h> #include <linux/blkdev.h> #include <linux/highmem.h> #include <linux/mm.h> #include <linux/kernel_stat.h> #include <linux/string.h> #include <linux/init.h> |
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#include <linux/completion.h> #include <linux/slab.h> #include <linux/swap.h> #include <linux/writeback.h> |
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#include <linux/task_io_accounting_ops.h> |
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#include <linux/fault-inject.h> |
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#include <linux/list_sort.h> |
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#define CREATE_TRACE_POINTS #include <trace/events/block.h> |
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|
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#include "blk.h" |
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EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap); |
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EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap); |
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EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_complete); |
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|
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static int __make_request(struct request_queue *q, struct bio *bio); |
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/* * For the allocated request tables */ |
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static struct kmem_cache *request_cachep; |
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/* * For queue allocation */ |
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struct kmem_cache *blk_requestq_cachep; |
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/* |
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* Controlling structure to kblockd */ |
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static struct workqueue_struct *kblockd_workqueue; |
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|
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static void drive_stat_acct(struct request *rq, int new_io) { |
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struct hd_struct *part; |
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int rw = rq_data_dir(rq); |
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int cpu; |
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|
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if (!blk_do_io_stat(rq)) |
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return; |
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cpu = part_stat_lock(); |
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|
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if (!new_io) { part = rq->part; |
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part_stat_inc(cpu, part, merges[rw]); |
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} else { part = disk_map_sector_rcu(rq->rq_disk, blk_rq_pos(rq)); |
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if (!hd_struct_try_get(part)) { |
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/* * The partition is already being removed, * the request will be accounted on the disk only * * We take a reference on disk->part0 although that * partition will never be deleted, so we can treat * it as any other partition. */ part = &rq->rq_disk->part0; |
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hd_struct_get(part); |
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} |
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part_round_stats(cpu, part); |
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part_inc_in_flight(part, rw); |
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rq->part = part; |
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} |
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|
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part_stat_unlock(); |
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} |
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void blk_queue_congestion_threshold(struct request_queue *q) |
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{ int nr; nr = q->nr_requests - (q->nr_requests / 8) + 1; if (nr > q->nr_requests) nr = q->nr_requests; q->nr_congestion_on = nr; nr = q->nr_requests - (q->nr_requests / 8) - (q->nr_requests / 16) - 1; if (nr < 1) nr = 1; q->nr_congestion_off = nr; } |
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/** * blk_get_backing_dev_info - get the address of a queue's backing_dev_info * @bdev: device * * Locates the passed device's request queue and returns the address of its * backing_dev_info * * Will return NULL if the request queue cannot be located. */ struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev) { struct backing_dev_info *ret = NULL; |
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struct request_queue *q = bdev_get_queue(bdev); |
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if (q) ret = &q->backing_dev_info; return ret; } |
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EXPORT_SYMBOL(blk_get_backing_dev_info); |
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void blk_rq_init(struct request_queue *q, struct request *rq) |
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{ |
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memset(rq, 0, sizeof(*rq)); |
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INIT_LIST_HEAD(&rq->queuelist); |
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INIT_LIST_HEAD(&rq->timeout_list); |
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rq->cpu = -1; |
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rq->q = q; |
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rq->__sector = (sector_t) -1; |
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INIT_HLIST_NODE(&rq->hash); RB_CLEAR_NODE(&rq->rb_node); |
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rq->cmd = rq->__cmd; |
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rq->cmd_len = BLK_MAX_CDB; |
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rq->tag = -1; |
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rq->ref_count = 1; |
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rq->start_time = jiffies; |
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set_start_time_ns(rq); |
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rq->part = NULL; |
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} |
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EXPORT_SYMBOL(blk_rq_init); |
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|
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static void req_bio_endio(struct request *rq, struct bio *bio, unsigned int nbytes, int error) |
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{ |
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if (error) clear_bit(BIO_UPTODATE, &bio->bi_flags); else if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) error = -EIO; |
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|
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if (unlikely(nbytes > bio->bi_size)) { printk(KERN_ERR "%s: want %u bytes done, %u left ", __func__, nbytes, bio->bi_size); nbytes = bio->bi_size; |
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} |
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|
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if (unlikely(rq->cmd_flags & REQ_QUIET)) set_bit(BIO_QUIET, &bio->bi_flags); |
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|
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bio->bi_size -= nbytes; bio->bi_sector += (nbytes >> 9); |
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|
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if (bio_integrity(bio)) bio_integrity_advance(bio, nbytes); |
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|
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/* don't actually finish bio if it's part of flush sequence */ if (bio->bi_size == 0 && !(rq->cmd_flags & REQ_FLUSH_SEQ)) bio_endio(bio, error); |
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} |
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|
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void blk_dump_rq_flags(struct request *rq, char *msg) { int bit; |
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printk(KERN_INFO "%s: dev %s: type=%x, flags=%x ", msg, |
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rq->rq_disk ? rq->rq_disk->disk_name : "?", rq->cmd_type, rq->cmd_flags); |
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|
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printk(KERN_INFO " sector %llu, nr/cnr %u/%u ", (unsigned long long)blk_rq_pos(rq), blk_rq_sectors(rq), blk_rq_cur_sectors(rq)); |
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printk(KERN_INFO " bio %p, biotail %p, buffer %p, len %u ", |
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rq->bio, rq->biotail, rq->buffer, blk_rq_bytes(rq)); |
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|
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if (rq->cmd_type == REQ_TYPE_BLOCK_PC) { |
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printk(KERN_INFO " cdb: "); |
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for (bit = 0; bit < BLK_MAX_CDB; bit++) |
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printk("%02x ", rq->cmd[bit]); printk(" "); } } |
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EXPORT_SYMBOL(blk_dump_rq_flags); |
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static void blk_delay_work(struct work_struct *work) |
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{ |
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struct request_queue *q; |
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|
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q = container_of(work, struct request_queue, delay_work.work); spin_lock_irq(q->queue_lock); |
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__blk_run_queue(q); |
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spin_unlock_irq(q->queue_lock); |
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} |
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/** |
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* blk_delay_queue - restart queueing after defined interval * @q: The &struct request_queue in question * @msecs: Delay in msecs |
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* * Description: |
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* 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 time. */ void blk_delay_queue(struct request_queue *q, unsigned long msecs) |
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{ |
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queue_delayed_work(kblockd_workqueue, &q->delay_work, msecs_to_jiffies(msecs)); |
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} |
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EXPORT_SYMBOL(blk_delay_queue); |
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|
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/** * blk_start_queue - restart a previously stopped queue |
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* @q: The &struct request_queue in question |
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* * Description: * blk_start_queue() will clear the stop flag on the queue, and call * the request_fn for the queue if it was in a stopped state when * entered. Also see blk_stop_queue(). Queue lock must be held. **/ |
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void blk_start_queue(struct request_queue *q) |
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{ |
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WARN_ON(!irqs_disabled()); |
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queue_flag_clear(QUEUE_FLAG_STOPPED, q); |
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__blk_run_queue(q); |
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} |
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EXPORT_SYMBOL(blk_start_queue); /** * blk_stop_queue - stop a queue |
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* @q: The &struct request_queue in question |
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* * Description: * The Linux block layer assumes that a block driver will consume all * entries on the request queue when the request_fn strategy is called. * Often this will not happen, because of hardware limitations (queue * depth settings). If a device driver gets a 'queue full' response, * or if it simply chooses not to queue more I/O at one point, it can * call this function to prevent the request_fn from being called until * the driver has signalled it's ready to go again. This happens by calling * blk_start_queue() to restart queue operations. Queue lock must be held. **/ |
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void blk_stop_queue(struct request_queue *q) |
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{ |
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__cancel_delayed_work(&q->delay_work); |
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queue_flag_set(QUEUE_FLAG_STOPPED, q); |
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} EXPORT_SYMBOL(blk_stop_queue); /** * blk_sync_queue - cancel any pending callbacks on a queue * @q: the queue * * Description: * The block layer may perform asynchronous callback activity * on a queue, such as calling the unplug function after a timeout. * A block device may call blk_sync_queue to ensure that any * such activity is cancelled, thus allowing it to release resources |
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* that the callbacks might use. The caller must already have made sure |
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* that its ->make_request_fn will not re-add plugging prior to calling * this function. * |
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* This function does not cancel any asynchronous activity arising * out of elevator or throttling code. That would require elevaotor_exit() * and blk_throtl_exit() to be called with queue lock initialized. * |
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*/ void blk_sync_queue(struct request_queue *q) { |
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del_timer_sync(&q->timeout); |
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cancel_delayed_work_sync(&q->delay_work); |
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} EXPORT_SYMBOL(blk_sync_queue); /** |
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* __blk_run_queue - run a single device queue |
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* @q: The queue to run |
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* * Description: * See @blk_run_queue. This variant must be called with the queue lock |
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* held and interrupts disabled. |
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*/ |
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void __blk_run_queue(struct request_queue *q) |
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{ |
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if (unlikely(blk_queue_stopped(q))) return; |
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q->request_fn(q); |
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} EXPORT_SYMBOL(__blk_run_queue); |
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|
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/** |
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* blk_run_queue_async - run a single device queue in workqueue context * @q: The queue to run * * Description: * Tells kblockd to perform the equivalent of @blk_run_queue on behalf * of us. */ void blk_run_queue_async(struct request_queue *q) { |
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if (likely(!blk_queue_stopped(q))) { __cancel_delayed_work(&q->delay_work); |
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queue_delayed_work(kblockd_workqueue, &q->delay_work, 0); |
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} |
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} |
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EXPORT_SYMBOL(blk_run_queue_async); |
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/** |
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* blk_run_queue - run a single device queue * @q: The queue to run |
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* * Description: * Invoke request handling on this queue, if it has pending work to do. |
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* May be used to restart queueing when a request has completed. |
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*/ void blk_run_queue(struct request_queue *q) { unsigned long flags; spin_lock_irqsave(q->queue_lock, flags); |
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__blk_run_queue(q); |
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spin_unlock_irqrestore(q->queue_lock, flags); } EXPORT_SYMBOL(blk_run_queue); |
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void blk_put_queue(struct request_queue *q) |
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{ kobject_put(&q->kobj); } |
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EXPORT_SYMBOL(blk_put_queue); |
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|
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/* |
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* Note: If a driver supplied the queue lock, it is disconnected * by this function. The actual state of the lock doesn't matter * here as the request_queue isn't accessible after this point * (QUEUE_FLAG_DEAD is set) and no other requests will be queued. |
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*/ |
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void blk_cleanup_queue(struct request_queue *q) |
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{ |
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/* * We know we have process context here, so we can be a little * cautious and ensure that pending block actions on this device * are done before moving on. Going into this function, we should * not have processes doing IO to this device. */ blk_sync_queue(q); |
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del_timer_sync(&q->backing_dev_info.laptop_mode_wb_timer); |
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mutex_lock(&q->sysfs_lock); |
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queue_flag_set_unlocked(QUEUE_FLAG_DEAD, q); |
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mutex_unlock(&q->sysfs_lock); |
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if (q->queue_lock != &q->__queue_lock) q->queue_lock = &q->__queue_lock; |
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|
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blk_put_queue(q); } |
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EXPORT_SYMBOL(blk_cleanup_queue); |
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static int blk_init_free_list(struct request_queue *q) |
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{ struct request_list *rl = &q->rq; |
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if (unlikely(rl->rq_pool)) return 0; |
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rl->count[BLK_RW_SYNC] = rl->count[BLK_RW_ASYNC] = 0; rl->starved[BLK_RW_SYNC] = rl->starved[BLK_RW_ASYNC] = 0; |
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rl->elvpriv = 0; |
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init_waitqueue_head(&rl->wait[BLK_RW_SYNC]); init_waitqueue_head(&rl->wait[BLK_RW_ASYNC]); |
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|
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rl->rq_pool = mempool_create_node(BLKDEV_MIN_RQ, mempool_alloc_slab, mempool_free_slab, request_cachep, q->node); |
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if (!rl->rq_pool) return -ENOMEM; return 0; } |
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struct request_queue *blk_alloc_queue(gfp_t gfp_mask) |
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389 |
{ |
1946089a1 [PATCH] NUMA awar... |
390 391 392 |
return blk_alloc_queue_node(gfp_mask, -1); } EXPORT_SYMBOL(blk_alloc_queue); |
1da177e4c Linux-2.6.12-rc2 |
393 |
|
165125e1e [BLOCK] Get rid o... |
394 |
struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id) |
1946089a1 [PATCH] NUMA awar... |
395 |
{ |
165125e1e [BLOCK] Get rid o... |
396 |
struct request_queue *q; |
e0bf68dde mm: bdi init hooks |
397 |
int err; |
1946089a1 [PATCH] NUMA awar... |
398 |
|
8324aa91d block: split tag ... |
399 |
q = kmem_cache_alloc_node(blk_requestq_cachep, |
94f6030ca Slab allocators: ... |
400 |
gfp_mask | __GFP_ZERO, node_id); |
1da177e4c Linux-2.6.12-rc2 |
401 402 |
if (!q) return NULL; |
0989a025d block: don't over... |
403 404 405 406 |
q->backing_dev_info.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE; q->backing_dev_info.state = 0; q->backing_dev_info.capabilities = BDI_CAP_MAP_COPY; |
d993831fa writeback: add na... |
407 |
q->backing_dev_info.name = "block"; |
0989a025d block: don't over... |
408 |
|
e0bf68dde mm: bdi init hooks |
409 410 |
err = bdi_init(&q->backing_dev_info); if (err) { |
8324aa91d block: split tag ... |
411 |
kmem_cache_free(blk_requestq_cachep, q); |
e0bf68dde mm: bdi init hooks |
412 413 |
return NULL; } |
e43473b7f blkio: Core imple... |
414 415 416 417 |
if (blk_throtl_init(q)) { kmem_cache_free(blk_requestq_cachep, q); return NULL; } |
31373d09d laptop-mode: Make... |
418 419 |
setup_timer(&q->backing_dev_info.laptop_mode_wb_timer, laptop_mode_timer_fn, (unsigned long) q); |
242f9dcb8 block: unify requ... |
420 421 |
setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q); INIT_LIST_HEAD(&q->timeout_list); |
ae1b15396 block: reimplemen... |
422 423 424 |
INIT_LIST_HEAD(&q->flush_queue[0]); INIT_LIST_HEAD(&q->flush_queue[1]); INIT_LIST_HEAD(&q->flush_data_in_flight); |
3cca6dc1c block: add API fo... |
425 |
INIT_DELAYED_WORK(&q->delay_work, blk_delay_work); |
483f4afc4 [PATCH] fix sysfs... |
426 |
|
8324aa91d block: split tag ... |
427 |
kobject_init(&q->kobj, &blk_queue_ktype); |
1da177e4c Linux-2.6.12-rc2 |
428 |
|
483f4afc4 [PATCH] fix sysfs... |
429 |
mutex_init(&q->sysfs_lock); |
e7e72bf64 Remove blkdev war... |
430 |
spin_lock_init(&q->__queue_lock); |
483f4afc4 [PATCH] fix sysfs... |
431 |
|
c94a96ac9 block: Initialize... |
432 433 434 435 436 |
/* * By default initialize queue_lock to internal lock and driver can * override it later if need be. */ q->queue_lock = &q->__queue_lock; |
1da177e4c Linux-2.6.12-rc2 |
437 438 |
return q; } |
1946089a1 [PATCH] NUMA awar... |
439 |
EXPORT_SYMBOL(blk_alloc_queue_node); |
1da177e4c Linux-2.6.12-rc2 |
440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 |
/** * blk_init_queue - prepare a request queue for use with a block device * @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 sorts requests and coalesces adjacent requests, then it must * call blk_init_queue(). The function @rfn will be called when there * are requests on the queue that need to be processed. If the device * supports plugging, then @rfn may not be called immediately when requests * are available on the queue, but may be called at some time later instead. * Plugged queues are generally unplugged when a buffer belonging to one * of the requests on the queue is needed, or due to memory pressure. * * @rfn is not required, or even expected, to remove all requests off the * queue, but only as many as it can handle at a time. If it does leave * requests on the queue, it is responsible for arranging that the requests * get dealt with eventually. * * The queue spin lock must be held while manipulating the requests on the |
a038e2536 [PATCH] blk_start... |
463 464 |
* request queue; this lock will be taken also from interrupt context, so irq * disabling is needed for it. |
1da177e4c Linux-2.6.12-rc2 |
465 |
* |
710027a48 Add some block/ s... |
466 |
* Function returns a pointer to the initialized request queue, or %NULL if |
1da177e4c Linux-2.6.12-rc2 |
467 468 469 470 471 472 |
* it didn't succeed. * * Note: * blk_init_queue() must be paired with a blk_cleanup_queue() call * when the block device is deactivated (such as at module unload). **/ |
1946089a1 [PATCH] NUMA awar... |
473 |
|
165125e1e [BLOCK] Get rid o... |
474 |
struct request_queue *blk_init_queue(request_fn_proc *rfn, spinlock_t *lock) |
1da177e4c Linux-2.6.12-rc2 |
475 |
{ |
1946089a1 [PATCH] NUMA awar... |
476 477 478 |
return blk_init_queue_node(rfn, lock, -1); } EXPORT_SYMBOL(blk_init_queue); |
165125e1e [BLOCK] Get rid o... |
479 |
struct request_queue * |
1946089a1 [PATCH] NUMA awar... |
480 481 |
blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id) { |
c86d1b8ae block: avoid unco... |
482 |
struct request_queue *uninit_q, *q; |
1da177e4c Linux-2.6.12-rc2 |
483 |
|
c86d1b8ae block: avoid unco... |
484 485 486 487 488 489 490 491 492 |
uninit_q = blk_alloc_queue_node(GFP_KERNEL, node_id); if (!uninit_q) return NULL; q = blk_init_allocated_queue_node(uninit_q, rfn, lock, node_id); if (!q) blk_cleanup_queue(uninit_q); return q; |
01effb0dc block: allow init... |
493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 |
} EXPORT_SYMBOL(blk_init_queue_node); struct request_queue * blk_init_allocated_queue(struct request_queue *q, request_fn_proc *rfn, spinlock_t *lock) { return blk_init_allocated_queue_node(q, rfn, lock, -1); } EXPORT_SYMBOL(blk_init_allocated_queue); struct request_queue * blk_init_allocated_queue_node(struct request_queue *q, request_fn_proc *rfn, spinlock_t *lock, int node_id) { |
1da177e4c Linux-2.6.12-rc2 |
508 509 |
if (!q) return NULL; |
1946089a1 [PATCH] NUMA awar... |
510 |
q->node = node_id; |
c86d1b8ae block: avoid unco... |
511 |
if (blk_init_free_list(q)) |
8669aafdb [PATCH] fix doubl... |
512 |
return NULL; |
1da177e4c Linux-2.6.12-rc2 |
513 514 |
q->request_fn = rfn; |
1da177e4c Linux-2.6.12-rc2 |
515 |
q->prep_rq_fn = NULL; |
28018c242 block: implement ... |
516 |
q->unprep_rq_fn = NULL; |
bc58ba946 block: add sysfs ... |
517 |
q->queue_flags = QUEUE_FLAG_DEFAULT; |
c94a96ac9 block: Initialize... |
518 519 520 521 |
/* Override internal queue lock with supplied lock pointer */ if (lock) q->queue_lock = lock; |
1da177e4c Linux-2.6.12-rc2 |
522 |
|
f3b144aa7 block: remove var... |
523 524 525 |
/* * This also sets hw/phys segments, boundary and size */ |
1da177e4c Linux-2.6.12-rc2 |
526 |
blk_queue_make_request(q, __make_request); |
1da177e4c Linux-2.6.12-rc2 |
527 |
|
44ec95425 [SCSI] sg: cap re... |
528 |
q->sg_reserved_size = INT_MAX; |
1da177e4c Linux-2.6.12-rc2 |
529 530 531 532 533 534 535 |
/* * all done */ if (!elevator_init(q, NULL)) { blk_queue_congestion_threshold(q); return q; } |
1da177e4c Linux-2.6.12-rc2 |
536 537 |
return NULL; } |
01effb0dc block: allow init... |
538 |
EXPORT_SYMBOL(blk_init_allocated_queue_node); |
1da177e4c Linux-2.6.12-rc2 |
539 |
|
165125e1e [BLOCK] Get rid o... |
540 |
int blk_get_queue(struct request_queue *q) |
1da177e4c Linux-2.6.12-rc2 |
541 |
{ |
fde6ad224 [PATCH] blk: bran... |
542 |
if (likely(!test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) { |
483f4afc4 [PATCH] fix sysfs... |
543 |
kobject_get(&q->kobj); |
1da177e4c Linux-2.6.12-rc2 |
544 545 546 547 548 |
return 0; } return 1; } |
d86e0e83b block: export blk... |
549 |
EXPORT_SYMBOL(blk_get_queue); |
1da177e4c Linux-2.6.12-rc2 |
550 |
|
165125e1e [BLOCK] Get rid o... |
551 |
static inline void blk_free_request(struct request_queue *q, struct request *rq) |
1da177e4c Linux-2.6.12-rc2 |
552 |
{ |
4aff5e233 [PATCH] Split str... |
553 |
if (rq->cmd_flags & REQ_ELVPRIV) |
cb98fc8bb [BLOCK] Reimpleme... |
554 |
elv_put_request(q, rq); |
1da177e4c Linux-2.6.12-rc2 |
555 556 |
mempool_free(rq, q->rq.rq_pool); } |
1ea25ecb7 [PATCH] Audit blo... |
557 |
static struct request * |
42dad7647 block: simplify I... |
558 |
blk_alloc_request(struct request_queue *q, int flags, int priv, gfp_t gfp_mask) |
1da177e4c Linux-2.6.12-rc2 |
559 560 561 562 563 |
{ struct request *rq = mempool_alloc(q->rq.rq_pool, gfp_mask); if (!rq) return NULL; |
2a4aa30c5 block: rename and... |
564 |
blk_rq_init(q, rq); |
1afb20f30 block: make rq_in... |
565 |
|
42dad7647 block: simplify I... |
566 |
rq->cmd_flags = flags | REQ_ALLOCED; |
1da177e4c Linux-2.6.12-rc2 |
567 |
|
cb98fc8bb [BLOCK] Reimpleme... |
568 |
if (priv) { |
cb78b285c [PATCH] Drop usel... |
569 |
if (unlikely(elv_set_request(q, rq, gfp_mask))) { |
cb98fc8bb [BLOCK] Reimpleme... |
570 571 572 |
mempool_free(rq, q->rq.rq_pool); return NULL; } |
4aff5e233 [PATCH] Split str... |
573 |
rq->cmd_flags |= REQ_ELVPRIV; |
cb98fc8bb [BLOCK] Reimpleme... |
574 |
} |
1da177e4c Linux-2.6.12-rc2 |
575 |
|
cb98fc8bb [BLOCK] Reimpleme... |
576 |
return rq; |
1da177e4c Linux-2.6.12-rc2 |
577 578 579 580 581 582 |
} /* * ioc_batching returns true if the ioc is a valid batching request and * should be given priority access to a request. */ |
165125e1e [BLOCK] Get rid o... |
583 |
static inline int ioc_batching(struct request_queue *q, struct io_context *ioc) |
1da177e4c Linux-2.6.12-rc2 |
584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 |
{ if (!ioc) return 0; /* * Make sure the process is able to allocate at least 1 request * even if the batch times out, otherwise we could theoretically * lose wakeups. */ return ioc->nr_batch_requests == q->nr_batching || (ioc->nr_batch_requests > 0 && time_before(jiffies, ioc->last_waited + BLK_BATCH_TIME)); } /* * ioc_set_batching sets ioc to be a new "batcher" if it is not one. This * will cause the process to be a "batcher" on all queues in the system. This * is the behaviour we want though - once it gets a wakeup it should be given * a nice run. */ |
165125e1e [BLOCK] Get rid o... |
604 |
static void ioc_set_batching(struct request_queue *q, struct io_context *ioc) |
1da177e4c Linux-2.6.12-rc2 |
605 606 607 608 609 610 611 |
{ if (!ioc || ioc_batching(q, ioc)) return; ioc->nr_batch_requests = q->nr_batching; ioc->last_waited = jiffies; } |
1faa16d22 block: change the... |
612 |
static void __freed_request(struct request_queue *q, int sync) |
1da177e4c Linux-2.6.12-rc2 |
613 614 |
{ struct request_list *rl = &q->rq; |
1faa16d22 block: change the... |
615 616 |
if (rl->count[sync] < queue_congestion_off_threshold(q)) blk_clear_queue_congested(q, sync); |
1da177e4c Linux-2.6.12-rc2 |
617 |
|
1faa16d22 block: change the... |
618 619 620 |
if (rl->count[sync] + 1 <= q->nr_requests) { if (waitqueue_active(&rl->wait[sync])) wake_up(&rl->wait[sync]); |
1da177e4c Linux-2.6.12-rc2 |
621 |
|
1faa16d22 block: change the... |
622 |
blk_clear_queue_full(q, sync); |
1da177e4c Linux-2.6.12-rc2 |
623 624 625 626 627 628 629 |
} } /* * A request has just been released. Account for it, update the full and * congestion status, wake up any waiters. Called under q->queue_lock. */ |
1faa16d22 block: change the... |
630 |
static void freed_request(struct request_queue *q, int sync, int priv) |
1da177e4c Linux-2.6.12-rc2 |
631 632 |
{ struct request_list *rl = &q->rq; |
1faa16d22 block: change the... |
633 |
rl->count[sync]--; |
cb98fc8bb [BLOCK] Reimpleme... |
634 635 |
if (priv) rl->elvpriv--; |
1da177e4c Linux-2.6.12-rc2 |
636 |
|
1faa16d22 block: change the... |
637 |
__freed_request(q, sync); |
1da177e4c Linux-2.6.12-rc2 |
638 |
|
1faa16d22 block: change the... |
639 640 |
if (unlikely(rl->starved[sync ^ 1])) __freed_request(q, sync ^ 1); |
1da177e4c Linux-2.6.12-rc2 |
641 |
} |
1da177e4c Linux-2.6.12-rc2 |
642 |
/* |
9d5a4e946 block: skip eleva... |
643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 |
* Determine if elevator data should be initialized when allocating the * request associated with @bio. */ static bool blk_rq_should_init_elevator(struct bio *bio) { if (!bio) return true; /* * Flush requests do not use the elevator so skip initialization. * This allows a request to share the flush and elevator data. */ if (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) return false; return true; } /* |
d6344532a [PATCH] blk: redu... |
662 663 664 |
* Get a free request, queue_lock must be held. * Returns NULL on failure, with queue_lock held. * Returns !NULL on success, with queue_lock *not held*. |
1da177e4c Linux-2.6.12-rc2 |
665 |
*/ |
165125e1e [BLOCK] Get rid o... |
666 |
static struct request *get_request(struct request_queue *q, int rw_flags, |
7749a8d42 [PATCH] Propagate... |
667 |
struct bio *bio, gfp_t gfp_mask) |
1da177e4c Linux-2.6.12-rc2 |
668 669 670 |
{ struct request *rq = NULL; struct request_list *rl = &q->rq; |
88ee5ef15 [BLOCK] ll_rw_blk... |
671 |
struct io_context *ioc = NULL; |
1faa16d22 block: change the... |
672 |
const bool is_sync = rw_is_sync(rw_flags) != 0; |
9d5a4e946 block: skip eleva... |
673 |
int may_queue, priv = 0; |
88ee5ef15 [BLOCK] ll_rw_blk... |
674 |
|
7749a8d42 [PATCH] Propagate... |
675 |
may_queue = elv_may_queue(q, rw_flags); |
88ee5ef15 [BLOCK] ll_rw_blk... |
676 677 |
if (may_queue == ELV_MQUEUE_NO) goto rq_starved; |
1faa16d22 block: change the... |
678 679 |
if (rl->count[is_sync]+1 >= queue_congestion_on_threshold(q)) { if (rl->count[is_sync]+1 >= q->nr_requests) { |
b5deef901 [PATCH] Make sure... |
680 |
ioc = current_io_context(GFP_ATOMIC, q->node); |
88ee5ef15 [BLOCK] ll_rw_blk... |
681 682 683 684 685 686 |
/* * The queue will fill after this allocation, so set * it as full, and mark this process as "batching". * This process will be allowed to complete a batch of * requests, others will be blocked. */ |
1faa16d22 block: change the... |
687 |
if (!blk_queue_full(q, is_sync)) { |
88ee5ef15 [BLOCK] ll_rw_blk... |
688 |
ioc_set_batching(q, ioc); |
1faa16d22 block: change the... |
689 |
blk_set_queue_full(q, is_sync); |
88ee5ef15 [BLOCK] ll_rw_blk... |
690 691 692 693 694 695 696 697 698 699 700 |
} else { if (may_queue != ELV_MQUEUE_MUST && !ioc_batching(q, ioc)) { /* * The queue is full and the allocating * process is not a "batcher", and not * exempted by the IO scheduler */ goto out; } } |
1da177e4c Linux-2.6.12-rc2 |
701 |
} |
1faa16d22 block: change the... |
702 |
blk_set_queue_congested(q, is_sync); |
1da177e4c Linux-2.6.12-rc2 |
703 |
} |
082cf69eb [PATCH] ll_rw_blk... |
704 705 706 707 708 |
/* * Only allow batching queuers to allocate up to 50% over the defined * limit of requests, otherwise we could have thousands of requests * allocated with any setting of ->nr_requests */ |
1faa16d22 block: change the... |
709 |
if (rl->count[is_sync] >= (3 * q->nr_requests / 2)) |
082cf69eb [PATCH] ll_rw_blk... |
710 |
goto out; |
fd782a4a9 [PATCH] Fix get_r... |
711 |
|
1faa16d22 block: change the... |
712 713 |
rl->count[is_sync]++; rl->starved[is_sync] = 0; |
cb98fc8bb [BLOCK] Reimpleme... |
714 |
|
9d5a4e946 block: skip eleva... |
715 716 717 718 719 |
if (blk_rq_should_init_elevator(bio)) { priv = !test_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags); if (priv) rl->elvpriv++; } |
cb98fc8bb [BLOCK] Reimpleme... |
720 |
|
f253b86b4 Revert "block: fi... |
721 722 |
if (blk_queue_io_stat(q)) rw_flags |= REQ_IO_STAT; |
1da177e4c Linux-2.6.12-rc2 |
723 |
spin_unlock_irq(q->queue_lock); |
7749a8d42 [PATCH] Propagate... |
724 |
rq = blk_alloc_request(q, rw_flags, priv, gfp_mask); |
88ee5ef15 [BLOCK] ll_rw_blk... |
725 |
if (unlikely(!rq)) { |
1da177e4c Linux-2.6.12-rc2 |
726 727 728 729 730 731 732 733 |
/* * Allocation failed presumably due to memory. Undo anything * we might have messed up. * * Allocating task should really be put onto the front of the * wait queue, but this is pretty rare. */ spin_lock_irq(q->queue_lock); |
1faa16d22 block: change the... |
734 |
freed_request(q, is_sync, priv); |
1da177e4c Linux-2.6.12-rc2 |
735 736 737 738 739 740 741 742 743 |
/* * in the very unlikely event that allocation failed and no * requests for this direction was pending, mark us starved * so that freeing of a request in the other direction will * notice us. another possible fix would be to split the * rq mempool into READ and WRITE */ rq_starved: |
1faa16d22 block: change the... |
744 745 |
if (unlikely(rl->count[is_sync] == 0)) rl->starved[is_sync] = 1; |
1da177e4c Linux-2.6.12-rc2 |
746 |
|
1da177e4c Linux-2.6.12-rc2 |
747 748 |
goto out; } |
88ee5ef15 [BLOCK] ll_rw_blk... |
749 750 751 752 753 754 |
/* * ioc may be NULL here, and ioc_batching will be false. That's * OK, if the queue is under the request limit then requests need * not count toward the nr_batch_requests limit. There will always * be some limit enforced by BLK_BATCH_TIME. */ |
1da177e4c Linux-2.6.12-rc2 |
755 756 |
if (ioc_batching(q, ioc)) ioc->nr_batch_requests--; |
6728cb0e6 block: make core ... |
757 |
|
1faa16d22 block: change the... |
758 |
trace_block_getrq(q, bio, rw_flags & 1); |
1da177e4c Linux-2.6.12-rc2 |
759 |
out: |
1da177e4c Linux-2.6.12-rc2 |
760 761 762 763 |
return rq; } /* |
7eaceacca block: remove per... |
764 765 |
* No available requests for this queue, wait for some requests to become * available. |
d6344532a [PATCH] blk: redu... |
766 767 |
* * Called with q->queue_lock held, and returns with it unlocked. |
1da177e4c Linux-2.6.12-rc2 |
768 |
*/ |
165125e1e [BLOCK] Get rid o... |
769 |
static struct request *get_request_wait(struct request_queue *q, int rw_flags, |
22e2c507c [PATCH] Update cf... |
770 |
struct bio *bio) |
1da177e4c Linux-2.6.12-rc2 |
771 |
{ |
1faa16d22 block: change the... |
772 |
const bool is_sync = rw_is_sync(rw_flags) != 0; |
1da177e4c Linux-2.6.12-rc2 |
773 |
struct request *rq; |
7749a8d42 [PATCH] Propagate... |
774 |
rq = get_request(q, rw_flags, bio, GFP_NOIO); |
450991bc1 [PATCH] blk: __ma... |
775 776 |
while (!rq) { DEFINE_WAIT(wait); |
05caf8dbc block: Move the s... |
777 |
struct io_context *ioc; |
1da177e4c Linux-2.6.12-rc2 |
778 |
struct request_list *rl = &q->rq; |
1faa16d22 block: change the... |
779 |
prepare_to_wait_exclusive(&rl->wait[is_sync], &wait, |
1da177e4c Linux-2.6.12-rc2 |
780 |
TASK_UNINTERRUPTIBLE); |
1faa16d22 block: change the... |
781 |
trace_block_sleeprq(q, bio, rw_flags & 1); |
1da177e4c Linux-2.6.12-rc2 |
782 |
|
05caf8dbc block: Move the s... |
783 784 |
spin_unlock_irq(q->queue_lock); io_schedule(); |
1da177e4c Linux-2.6.12-rc2 |
785 |
|
05caf8dbc block: Move the s... |
786 787 788 789 790 791 792 793 |
/* * After sleeping, we become a "batching" process and * will be able to allocate at least one request, and * up to a big batch of them for a small period time. * See ioc_batching, ioc_set_batching */ ioc = current_io_context(GFP_NOIO, q->node); ioc_set_batching(q, ioc); |
d6344532a [PATCH] blk: redu... |
794 |
|
05caf8dbc block: Move the s... |
795 |
spin_lock_irq(q->queue_lock); |
1faa16d22 block: change the... |
796 |
finish_wait(&rl->wait[is_sync], &wait); |
05caf8dbc block: Move the s... |
797 798 799 |
rq = get_request(q, rw_flags, bio, GFP_NOIO); }; |
1da177e4c Linux-2.6.12-rc2 |
800 801 802 |
return rq; } |
165125e1e [BLOCK] Get rid o... |
803 |
struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask) |
1da177e4c Linux-2.6.12-rc2 |
804 805 |
{ struct request *rq; |
bfe159a51 [SCSI] fix crash ... |
806 807 |
if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) return NULL; |
1da177e4c Linux-2.6.12-rc2 |
808 |
BUG_ON(rw != READ && rw != WRITE); |
d6344532a [PATCH] blk: redu... |
809 810 |
spin_lock_irq(q->queue_lock); if (gfp_mask & __GFP_WAIT) { |
22e2c507c [PATCH] Update cf... |
811 |
rq = get_request_wait(q, rw, NULL); |
d6344532a [PATCH] blk: redu... |
812 |
} else { |
22e2c507c [PATCH] Update cf... |
813 |
rq = get_request(q, rw, NULL, gfp_mask); |
d6344532a [PATCH] blk: redu... |
814 815 816 817 |
if (!rq) spin_unlock_irq(q->queue_lock); } /* q->queue_lock is unlocked at this point */ |
1da177e4c Linux-2.6.12-rc2 |
818 819 820 |
return rq; } |
1da177e4c Linux-2.6.12-rc2 |
821 822 823 |
EXPORT_SYMBOL(blk_get_request); /** |
79eb63e9e block: Add blk_ma... |
824 |
* blk_make_request - given a bio, allocate a corresponding struct request. |
8ebf97560 block: fix kernel... |
825 |
* @q: target request queue |
79eb63e9e block: Add blk_ma... |
826 827 |
* @bio: The bio describing the memory mappings that will be submitted for IO. * It may be a chained-bio properly constructed by block/bio layer. |
8ebf97560 block: fix kernel... |
828 |
* @gfp_mask: gfp flags to be used for memory allocation |
dc72ef4ae [PATCH] Add blk_s... |
829 |
* |
79eb63e9e block: Add blk_ma... |
830 831 832 833 |
* blk_make_request is the parallel of generic_make_request for BLOCK_PC * type commands. Where the struct request needs to be farther initialized by * the caller. It is passed a &struct bio, which describes the memory info of * the I/O transfer. |
dc72ef4ae [PATCH] Add blk_s... |
834 |
* |
79eb63e9e block: Add blk_ma... |
835 836 837 838 839 840 841 842 843 |
* The caller of blk_make_request must make sure that bi_io_vec * are set to describe the memory buffers. That bio_data_dir() will return * the needed direction of the request. (And all bio's in the passed bio-chain * are properly set accordingly) * * If called under none-sleepable conditions, mapped bio buffers must not * need bouncing, by calling the appropriate masked or flagged allocator, * suitable for the target device. Otherwise the call to blk_queue_bounce will * BUG. |
53674ac5a block: add warnin... |
844 845 846 847 848 849 850 851 852 |
* * WARNING: When allocating/cloning a bio-chain, careful consideration should be * given to how you allocate bios. In particular, you cannot use __GFP_WAIT for * anything but the first bio in the chain. Otherwise you risk waiting for IO * completion of a bio that hasn't been submitted yet, thus resulting in a * deadlock. Alternatively bios should be allocated using bio_kmalloc() instead * of bio_alloc(), as that avoids the mempool deadlock. * If possible a big IO should be split into smaller parts when allocation * fails. Partial allocation should not be an error, or you risk a live-lock. |
dc72ef4ae [PATCH] Add blk_s... |
853 |
*/ |
79eb63e9e block: Add blk_ma... |
854 855 |
struct request *blk_make_request(struct request_queue *q, struct bio *bio, gfp_t gfp_mask) |
dc72ef4ae [PATCH] Add blk_s... |
856 |
{ |
79eb63e9e block: Add blk_ma... |
857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 |
struct request *rq = blk_get_request(q, bio_data_dir(bio), gfp_mask); if (unlikely(!rq)) return ERR_PTR(-ENOMEM); for_each_bio(bio) { struct bio *bounce_bio = bio; int ret; blk_queue_bounce(q, &bounce_bio); ret = blk_rq_append_bio(q, rq, bounce_bio); if (unlikely(ret)) { blk_put_request(rq); return ERR_PTR(ret); } } return rq; |
dc72ef4ae [PATCH] Add blk_s... |
875 |
} |
79eb63e9e block: Add blk_ma... |
876 |
EXPORT_SYMBOL(blk_make_request); |
dc72ef4ae [PATCH] Add blk_s... |
877 878 |
/** |
1da177e4c Linux-2.6.12-rc2 |
879 880 881 882 883 884 885 886 887 |
* blk_requeue_request - put a request back on queue * @q: request queue where request should be inserted * @rq: request to be inserted * * Description: * Drivers often keep queueing requests until the hardware cannot accept * more, when that condition happens we need to put the request back * on the queue. Must be called with queue lock held. */ |
165125e1e [BLOCK] Get rid o... |
888 |
void blk_requeue_request(struct request_queue *q, struct request *rq) |
1da177e4c Linux-2.6.12-rc2 |
889 |
{ |
242f9dcb8 block: unify requ... |
890 891 |
blk_delete_timer(rq); blk_clear_rq_complete(rq); |
5f3ea37c7 blktrace: port to... |
892 |
trace_block_rq_requeue(q, rq); |
2056a782f [PATCH] Block que... |
893 |
|
1da177e4c Linux-2.6.12-rc2 |
894 895 |
if (blk_rq_tagged(rq)) blk_queue_end_tag(q, rq); |
ba396a6c1 block: fix oops w... |
896 |
BUG_ON(blk_queued_rq(rq)); |
1da177e4c Linux-2.6.12-rc2 |
897 898 |
elv_requeue_request(q, rq); } |
1da177e4c Linux-2.6.12-rc2 |
899 |
EXPORT_SYMBOL(blk_requeue_request); |
73c101011 block: initial pa... |
900 901 902 903 |
static void add_acct_request(struct request_queue *q, struct request *rq, int where) { drive_stat_acct(rq, 1); |
7eaceacca block: remove per... |
904 |
__elv_add_request(q, rq, where); |
73c101011 block: initial pa... |
905 |
} |
1da177e4c Linux-2.6.12-rc2 |
906 |
/** |
710027a48 Add some block/ s... |
907 |
* blk_insert_request - insert a special request into a request queue |
1da177e4c Linux-2.6.12-rc2 |
908 909 910 911 |
* @q: request queue where request should be inserted * @rq: request to be inserted * @at_head: insert request at head or tail of queue * @data: private data |
1da177e4c Linux-2.6.12-rc2 |
912 913 914 915 916 |
* * Description: * Many block devices need to execute commands asynchronously, so they don't * block the whole kernel from preemption during request execution. This is * accomplished normally by inserting aritficial requests tagged as |
710027a48 Add some block/ s... |
917 918 |
* REQ_TYPE_SPECIAL in to the corresponding request queue, and letting them * be scheduled for actual execution by the request queue. |
1da177e4c Linux-2.6.12-rc2 |
919 920 921 922 923 924 |
* * We have the option of inserting the head or the tail of the queue. * Typically we use the tail for new ioctls and so forth. We use the head * of the queue for things like a QUEUE_FULL message from a device, or a * host that is unable to accept a particular command. */ |
165125e1e [BLOCK] Get rid o... |
925 |
void blk_insert_request(struct request_queue *q, struct request *rq, |
867d1191f [SCSI] remove req... |
926 |
int at_head, void *data) |
1da177e4c Linux-2.6.12-rc2 |
927 |
{ |
867d1191f [SCSI] remove req... |
928 |
int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK; |
1da177e4c Linux-2.6.12-rc2 |
929 930 931 932 933 934 935 |
unsigned long flags; /* * tell I/O scheduler that this isn't a regular read/write (ie it * must not attempt merges on this) and that it acts as a soft * barrier */ |
4aff5e233 [PATCH] Split str... |
936 |
rq->cmd_type = REQ_TYPE_SPECIAL; |
1da177e4c Linux-2.6.12-rc2 |
937 938 939 940 941 942 943 944 |
rq->special = data; spin_lock_irqsave(q->queue_lock, flags); /* * If command is tagged, release the tag */ |
867d1191f [SCSI] remove req... |
945 946 |
if (blk_rq_tagged(rq)) blk_queue_end_tag(q, rq); |
1da177e4c Linux-2.6.12-rc2 |
947 |
|
73c101011 block: initial pa... |
948 |
add_acct_request(q, rq, where); |
24ecfbe27 block: add blk_ru... |
949 |
__blk_run_queue(q); |
1da177e4c Linux-2.6.12-rc2 |
950 951 |
spin_unlock_irqrestore(q->queue_lock, flags); } |
1da177e4c Linux-2.6.12-rc2 |
952 |
EXPORT_SYMBOL(blk_insert_request); |
074a7aca7 block: move stats... |
953 954 955 956 957 |
static void part_round_stats_single(int cpu, struct hd_struct *part, unsigned long now) { if (now == part->stamp) return; |
316d315bf block: Seperate r... |
958 |
if (part_in_flight(part)) { |
074a7aca7 block: move stats... |
959 |
__part_stat_add(cpu, part, time_in_queue, |
316d315bf block: Seperate r... |
960 |
part_in_flight(part) * (now - part->stamp)); |
074a7aca7 block: move stats... |
961 962 963 964 965 966 |
__part_stat_add(cpu, part, io_ticks, (now - part->stamp)); } part->stamp = now; } /** |
496aa8a98 block: fix curren... |
967 968 969 |
* part_round_stats() - Round off the performance stats on a struct disk_stats. * @cpu: cpu number for stats access * @part: target partition |
1da177e4c Linux-2.6.12-rc2 |
970 971 972 973 974 975 976 977 978 979 980 981 |
* * The average IO queue length and utilisation statistics are maintained * by observing the current state of the queue length and the amount of * time it has been in this state for. * * Normally, that accounting is done on IO completion, but that can result * in more than a second's worth of IO being accounted for within any one * second, leading to >100% utilisation. To deal with that, we call this * function to do a round-off before returning the results when reading * /proc/diskstats. This accounts immediately for all queue usage up to * the current jiffies and restarts the counters again. */ |
c99590591 block: fix diskst... |
982 |
void part_round_stats(int cpu, struct hd_struct *part) |
6f2576af5 Enhanced partitio... |
983 984 |
{ unsigned long now = jiffies; |
074a7aca7 block: move stats... |
985 986 987 |
if (part->partno) part_round_stats_single(cpu, &part_to_disk(part)->part0, now); part_round_stats_single(cpu, part, now); |
6f2576af5 Enhanced partitio... |
988 |
} |
074a7aca7 block: move stats... |
989 |
EXPORT_SYMBOL_GPL(part_round_stats); |
6f2576af5 Enhanced partitio... |
990 |
|
1da177e4c Linux-2.6.12-rc2 |
991 992 993 |
/* * queue lock must be held */ |
165125e1e [BLOCK] Get rid o... |
994 |
void __blk_put_request(struct request_queue *q, struct request *req) |
1da177e4c Linux-2.6.12-rc2 |
995 |
{ |
1da177e4c Linux-2.6.12-rc2 |
996 997 998 999 |
if (unlikely(!q)) return; if (unlikely(--req->ref_count)) return; |
8922e16cf [PATCH] 01/05 Imp... |
1000 |
elv_completed_request(q, req); |
1cd96c242 block: WARN in __... |
1001 1002 |
/* this is a bio leak */ WARN_ON(req->bio != NULL); |
1da177e4c Linux-2.6.12-rc2 |
1003 1004 1005 1006 |
/* * Request may not have originated from ll_rw_blk. if not, * it didn't come out of our reserved rq pools */ |
49171e5c6 [PATCH] Remove st... |
1007 |
if (req->cmd_flags & REQ_ALLOCED) { |
1faa16d22 block: change the... |
1008 |
int is_sync = rq_is_sync(req) != 0; |
4aff5e233 [PATCH] Split str... |
1009 |
int priv = req->cmd_flags & REQ_ELVPRIV; |
1da177e4c Linux-2.6.12-rc2 |
1010 |
|
1da177e4c Linux-2.6.12-rc2 |
1011 |
BUG_ON(!list_empty(&req->queuelist)); |
9817064b6 [PATCH] elevator:... |
1012 |
BUG_ON(!hlist_unhashed(&req->hash)); |
1da177e4c Linux-2.6.12-rc2 |
1013 1014 |
blk_free_request(q, req); |
1faa16d22 block: change the... |
1015 |
freed_request(q, is_sync, priv); |
1da177e4c Linux-2.6.12-rc2 |
1016 1017 |
} } |
6e39b69e7 [SCSI] export blk... |
1018 |
EXPORT_SYMBOL_GPL(__blk_put_request); |
1da177e4c Linux-2.6.12-rc2 |
1019 1020 |
void blk_put_request(struct request *req) { |
8922e16cf [PATCH] 01/05 Imp... |
1021 |
unsigned long flags; |
165125e1e [BLOCK] Get rid o... |
1022 |
struct request_queue *q = req->q; |
8922e16cf [PATCH] 01/05 Imp... |
1023 |
|
52a93ba81 block: remove the... |
1024 1025 1026 |
spin_lock_irqsave(q->queue_lock, flags); __blk_put_request(q, req); spin_unlock_irqrestore(q->queue_lock, flags); |
1da177e4c Linux-2.6.12-rc2 |
1027 |
} |
1da177e4c Linux-2.6.12-rc2 |
1028 |
EXPORT_SYMBOL(blk_put_request); |
66ac02801 block: don't allo... |
1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 |
/** * blk_add_request_payload - add a payload to a request * @rq: request to update * @page: page backing the payload * @len: length of the payload. * * This allows to later add a payload to an already submitted request by * a block driver. The driver needs to take care of freeing the payload * itself. * * Note that this is a quite horrible hack and nothing but handling of * discard requests should ever use it. */ void blk_add_request_payload(struct request *rq, struct page *page, unsigned int len) { struct bio *bio = rq->bio; bio->bi_io_vec->bv_page = page; bio->bi_io_vec->bv_offset = 0; bio->bi_io_vec->bv_len = len; bio->bi_size = len; bio->bi_vcnt = 1; bio->bi_phys_segments = 1; rq->__data_len = rq->resid_len = len; rq->nr_phys_segments = 1; rq->buffer = bio_data(bio); } EXPORT_SYMBOL_GPL(blk_add_request_payload); |
73c101011 block: initial pa... |
1060 1061 1062 1063 |
static bool bio_attempt_back_merge(struct request_queue *q, struct request *req, struct bio *bio) { const int ff = bio->bi_rw & REQ_FAILFAST_MASK; |
73c101011 block: initial pa... |
1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 |
if (!ll_back_merge_fn(q, req, bio)) return false; trace_block_bio_backmerge(q, bio); if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff) blk_rq_set_mixed_merge(req); req->biotail->bi_next = bio; req->biotail = bio; req->__data_len += bio->bi_size; req->ioprio = ioprio_best(req->ioprio, bio_prio(bio)); drive_stat_acct(req, 0); |
95cf3dd9d block: call elv_b... |
1078 |
elv_bio_merged(q, req, bio); |
73c101011 block: initial pa... |
1079 1080 1081 1082 1083 1084 1085 |
return true; } static bool bio_attempt_front_merge(struct request_queue *q, struct request *req, struct bio *bio) { const int ff = bio->bi_rw & REQ_FAILFAST_MASK; |
73c101011 block: initial pa... |
1086 |
|
73c101011 block: initial pa... |
1087 1088 1089 1090 1091 1092 1093 |
if (!ll_front_merge_fn(q, req, bio)) return false; trace_block_bio_frontmerge(q, bio); if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff) blk_rq_set_mixed_merge(req); |
73c101011 block: initial pa... |
1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 |
bio->bi_next = req->bio; req->bio = bio; /* * may not be valid. if the low level driver said * it didn't need a bounce buffer then it better * not touch req->buffer either... */ req->buffer = bio_data(bio); req->__sector = bio->bi_sector; req->__data_len += bio->bi_size; req->ioprio = ioprio_best(req->ioprio, bio_prio(bio)); drive_stat_acct(req, 0); |
95cf3dd9d block: call elv_b... |
1108 |
elv_bio_merged(q, req, bio); |
73c101011 block: initial pa... |
1109 1110 1111 1112 1113 |
return true; } /* * Attempts to merge with the plugged list in the current process. Returns |
25985edce Fix common misspe... |
1114 |
* true if merge was successful, otherwise false. |
73c101011 block: initial pa... |
1115 1116 |
*/ static bool attempt_plug_merge(struct task_struct *tsk, struct request_queue *q, |
56ebdaf2f block: simplify f... |
1117 |
struct bio *bio, unsigned int *request_count) |
73c101011 block: initial pa... |
1118 1119 1120 1121 1122 1123 1124 1125 |
{ struct blk_plug *plug; struct request *rq; bool ret = false; plug = tsk->plug; if (!plug) goto out; |
56ebdaf2f block: simplify f... |
1126 |
*request_count = 0; |
73c101011 block: initial pa... |
1127 1128 1129 |
list_for_each_entry_reverse(rq, &plug->list, queuelist) { int el_ret; |
56ebdaf2f block: simplify f... |
1130 |
(*request_count)++; |
73c101011 block: initial pa... |
1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 |
if (rq->q != q) continue; el_ret = elv_try_merge(rq, bio); if (el_ret == ELEVATOR_BACK_MERGE) { ret = bio_attempt_back_merge(q, rq, bio); if (ret) break; } else if (el_ret == ELEVATOR_FRONT_MERGE) { ret = bio_attempt_front_merge(q, rq, bio); if (ret) break; } } out: return ret; } |
86db1e297 block: continue l... |
1148 |
void init_request_from_bio(struct request *req, struct bio *bio) |
52d9e6753 [BLOCK] ll_rw_blk... |
1149 |
{ |
c7c22e4d5 block: add suppor... |
1150 |
req->cpu = bio->bi_comp_cpu; |
4aff5e233 [PATCH] Split str... |
1151 |
req->cmd_type = REQ_TYPE_FS; |
52d9e6753 [BLOCK] ll_rw_blk... |
1152 |
|
7b6d91dae block: unify flag... |
1153 1154 |
req->cmd_flags |= bio->bi_rw & REQ_COMMON_MASK; if (bio->bi_rw & REQ_RAHEAD) |
a82afdfcb block: use the sa... |
1155 |
req->cmd_flags |= REQ_FAILFAST_MASK; |
b31dc66a5 [PATCH] Kill PF_S... |
1156 |
|
52d9e6753 [BLOCK] ll_rw_blk... |
1157 |
req->errors = 0; |
a2dec7b36 block: hide reque... |
1158 |
req->__sector = bio->bi_sector; |
52d9e6753 [BLOCK] ll_rw_blk... |
1159 |
req->ioprio = bio_prio(bio); |
bc1c56fde Share code betwee... |
1160 |
blk_rq_bio_prep(req->q, req, bio); |
52d9e6753 [BLOCK] ll_rw_blk... |
1161 |
} |
165125e1e [BLOCK] Get rid o... |
1162 |
static int __make_request(struct request_queue *q, struct bio *bio) |
1da177e4c Linux-2.6.12-rc2 |
1163 |
{ |
5e00d1b5b BLOCK: fix bio.bi... |
1164 |
const bool sync = !!(bio->bi_rw & REQ_SYNC); |
73c101011 block: initial pa... |
1165 1166 1167 |
struct blk_plug *plug; int el_ret, rw_flags, where = ELEVATOR_INSERT_SORT; struct request *req; |
56ebdaf2f block: simplify f... |
1168 |
unsigned int request_count = 0; |
1da177e4c Linux-2.6.12-rc2 |
1169 |
|
1da177e4c Linux-2.6.12-rc2 |
1170 1171 1172 1173 1174 1175 |
/* * low level driver can indicate that it wants pages above a * certain limit bounced to low memory (ie for highmem, or even * ISA dma in theory) */ blk_queue_bounce(q, &bio); |
4fed947cb block: implement ... |
1176 |
if (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) { |
73c101011 block: initial pa... |
1177 |
spin_lock_irq(q->queue_lock); |
ae1b15396 block: reimplemen... |
1178 |
where = ELEVATOR_INSERT_FLUSH; |
28e7d1845 block: drop barri... |
1179 1180 |
goto get_rq; } |
73c101011 block: initial pa... |
1181 1182 1183 1184 |
/* * Check if we can merge with the plugged list before grabbing * any locks. */ |
56ebdaf2f block: simplify f... |
1185 |
if (attempt_plug_merge(current, q, bio, &request_count)) |
6728cb0e6 block: make core ... |
1186 |
goto out; |
1da177e4c Linux-2.6.12-rc2 |
1187 |
|
73c101011 block: initial pa... |
1188 |
spin_lock_irq(q->queue_lock); |
2056a782f [PATCH] Block que... |
1189 |
|
73c101011 block: initial pa... |
1190 1191 |
el_ret = elv_merge(q, &req, bio); if (el_ret == ELEVATOR_BACK_MERGE) { |
73c101011 block: initial pa... |
1192 1193 1194 1195 1196 1197 |
if (bio_attempt_back_merge(q, req, bio)) { if (!attempt_back_merge(q, req)) elv_merged_request(q, req, el_ret); goto out_unlock; } } else if (el_ret == ELEVATOR_FRONT_MERGE) { |
73c101011 block: initial pa... |
1198 1199 1200 1201 |
if (bio_attempt_front_merge(q, req, bio)) { if (!attempt_front_merge(q, req)) elv_merged_request(q, req, el_ret); goto out_unlock; |
80a761fd3 block: implement ... |
1202 |
} |
1da177e4c Linux-2.6.12-rc2 |
1203 |
} |
450991bc1 [PATCH] blk: __ma... |
1204 |
get_rq: |
1da177e4c Linux-2.6.12-rc2 |
1205 |
/* |
7749a8d42 [PATCH] Propagate... |
1206 1207 1208 1209 1210 1211 |
* This sync check and mask will be re-done in init_request_from_bio(), * but we need to set it earlier to expose the sync flag to the * rq allocator and io schedulers. */ rw_flags = bio_data_dir(bio); if (sync) |
7b6d91dae block: unify flag... |
1212 |
rw_flags |= REQ_SYNC; |
7749a8d42 [PATCH] Propagate... |
1213 1214 |
/* |
450991bc1 [PATCH] blk: __ma... |
1215 |
* Grab a free request. This is might sleep but can not fail. |
d6344532a [PATCH] blk: redu... |
1216 |
* Returns with the queue unlocked. |
450991bc1 [PATCH] blk: __ma... |
1217 |
*/ |
7749a8d42 [PATCH] Propagate... |
1218 |
req = get_request_wait(q, rw_flags, bio); |
d6344532a [PATCH] blk: redu... |
1219 |
|
450991bc1 [PATCH] blk: __ma... |
1220 1221 1222 1223 1224 |
/* * After dropping the lock and possibly sleeping here, our request * may now be mergeable after it had proven unmergeable (above). * We don't worry about that case for efficiency. It won't happen * often, and the elevators are able to handle it. |
1da177e4c Linux-2.6.12-rc2 |
1225 |
*/ |
52d9e6753 [BLOCK] ll_rw_blk... |
1226 |
init_request_from_bio(req, bio); |
1da177e4c Linux-2.6.12-rc2 |
1227 |
|
c7c22e4d5 block: add suppor... |
1228 |
if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags) || |
5757a6d76 block: strict rq_... |
1229 |
bio_flagged(bio, BIO_CPU_AFFINE)) |
11ccf116d block: fix warnin... |
1230 |
req->cpu = raw_smp_processor_id(); |
73c101011 block: initial pa... |
1231 1232 |
plug = current->plug; |
721a9602e block: kill off R... |
1233 |
if (plug) { |
dc6d36c97 block: readd plug... |
1234 1235 1236 1237 1238 1239 1240 1241 1242 |
/* * If this is the first request added after a plug, fire * of a plug trace. If others have been added before, check * if we have multiple devices in this plug. If so, make a * note to sort the list before dispatch. */ if (list_empty(&plug->list)) trace_block_plug(q); else if (!plug->should_sort) { |
73c101011 block: initial pa... |
1243 1244 1245 1246 1247 1248 |
struct request *__rq; __rq = list_entry_rq(plug->list.prev); if (__rq->q != q) plug->should_sort = 1; } |
56ebdaf2f block: simplify f... |
1249 |
if (request_count >= BLK_MAX_REQUEST_COUNT) |
55c022bbd block: avoid buil... |
1250 |
blk_flush_plug_list(plug, false); |
a63271627 block: change for... |
1251 1252 |
list_add_tail(&req->queuelist, &plug->list); drive_stat_acct(req, 1); |
73c101011 block: initial pa... |
1253 1254 1255 |
} else { spin_lock_irq(q->queue_lock); add_acct_request(q, req, where); |
24ecfbe27 block: add blk_ru... |
1256 |
__blk_run_queue(q); |
73c101011 block: initial pa... |
1257 1258 1259 |
out_unlock: spin_unlock_irq(q->queue_lock); } |
1da177e4c Linux-2.6.12-rc2 |
1260 |
out: |
1da177e4c Linux-2.6.12-rc2 |
1261 |
return 0; |
1da177e4c Linux-2.6.12-rc2 |
1262 1263 1264 1265 1266 1267 1268 1269 |
} /* * If bio->bi_dev is a partition, remap the location */ static inline void blk_partition_remap(struct bio *bio) { struct block_device *bdev = bio->bi_bdev; |
bf2de6f5a block: Initial su... |
1270 |
if (bio_sectors(bio) && bdev != bdev->bd_contains) { |
1da177e4c Linux-2.6.12-rc2 |
1271 |
struct hd_struct *p = bdev->bd_part; |
1da177e4c Linux-2.6.12-rc2 |
1272 1273 |
bio->bi_sector += p->start_sect; bio->bi_bdev = bdev->bd_contains; |
c7149d6bc Fix remap handlin... |
1274 |
|
d07335e51 block: Rename "bl... |
1275 1276 1277 |
trace_block_bio_remap(bdev_get_queue(bio->bi_bdev), bio, bdev->bd_dev, bio->bi_sector - p->start_sect); |
1da177e4c Linux-2.6.12-rc2 |
1278 1279 |
} } |
1da177e4c Linux-2.6.12-rc2 |
1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 |
static void handle_bad_sector(struct bio *bio) { char b[BDEVNAME_SIZE]; printk(KERN_INFO "attempt to access beyond end of device "); printk(KERN_INFO "%s: rw=%ld, want=%Lu, limit=%Lu ", bdevname(bio->bi_bdev, b), bio->bi_rw, (unsigned long long)bio->bi_sector + bio_sectors(bio), |
77304d2ab block: read i_siz... |
1291 |
(long long)(i_size_read(bio->bi_bdev->bd_inode) >> 9)); |
1da177e4c Linux-2.6.12-rc2 |
1292 1293 1294 |
set_bit(BIO_EOF, &bio->bi_flags); } |
c17bb4951 [PATCH] fault-inj... |
1295 1296 1297 1298 1299 1300 1301 1302 1303 |
#ifdef CONFIG_FAIL_MAKE_REQUEST static DECLARE_FAULT_ATTR(fail_make_request); static int __init setup_fail_make_request(char *str) { return setup_fault_attr(&fail_make_request, str); } __setup("fail_make_request=", setup_fail_make_request); |
b2c9cd379 fail_make_request... |
1304 |
static bool should_fail_request(struct hd_struct *part, unsigned int bytes) |
c17bb4951 [PATCH] fault-inj... |
1305 |
{ |
b2c9cd379 fail_make_request... |
1306 |
return part->make_it_fail && should_fail(&fail_make_request, bytes); |
c17bb4951 [PATCH] fault-inj... |
1307 1308 1309 1310 |
} static int __init fail_make_request_debugfs(void) { |
dd48c085c fault-injection: ... |
1311 1312 1313 1314 |
struct dentry *dir = fault_create_debugfs_attr("fail_make_request", NULL, &fail_make_request); return IS_ERR(dir) ? PTR_ERR(dir) : 0; |
c17bb4951 [PATCH] fault-inj... |
1315 1316 1317 1318 1319 |
} late_initcall(fail_make_request_debugfs); #else /* CONFIG_FAIL_MAKE_REQUEST */ |
b2c9cd379 fail_make_request... |
1320 1321 |
static inline bool should_fail_request(struct hd_struct *part, unsigned int bytes) |
c17bb4951 [PATCH] fault-inj... |
1322 |
{ |
b2c9cd379 fail_make_request... |
1323 |
return false; |
c17bb4951 [PATCH] fault-inj... |
1324 1325 1326 |
} #endif /* CONFIG_FAIL_MAKE_REQUEST */ |
c07e2b412 block: factor our... |
1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 |
/* * Check whether this bio extends beyond the end of the device. */ static inline int bio_check_eod(struct bio *bio, unsigned int nr_sectors) { sector_t maxsector; if (!nr_sectors) return 0; /* Test device or partition size, when known. */ |
77304d2ab block: read i_siz... |
1338 |
maxsector = i_size_read(bio->bi_bdev->bd_inode) >> 9; |
c07e2b412 block: factor our... |
1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 |
if (maxsector) { sector_t sector = bio->bi_sector; if (maxsector < nr_sectors || maxsector - nr_sectors < sector) { /* * This may well happen - the kernel calls bread() * without checking the size of the device, e.g., when * mounting a device. */ handle_bad_sector(bio); return 1; } } return 0; } |
1da177e4c Linux-2.6.12-rc2 |
1355 |
/** |
710027a48 Add some block/ s... |
1356 |
* generic_make_request - hand a buffer to its device driver for I/O |
1da177e4c Linux-2.6.12-rc2 |
1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 |
* @bio: The bio describing the location in memory and on the device. * * generic_make_request() is used to make I/O requests of block * devices. It is passed a &struct bio, which describes the I/O that needs * to be done. * * generic_make_request() does not return any status. The * success/failure status of the request, along with notification of * completion, is delivered asynchronously through the bio->bi_end_io * function described (one day) else where. * * The caller of generic_make_request must make sure that bi_io_vec * are set to describe the memory buffer, and that bi_dev and bi_sector are * set to describe the device address, and the * bi_end_io and optionally bi_private are set to describe how * completion notification should be signaled. * * generic_make_request and the drivers it calls may use bi_next if this * bio happens to be merged with someone else, and may change bi_dev and * bi_sector for remaps as it sees fit. So the values of these fields * should NOT be depended on after the call to generic_make_request. */ |
d89d87965 When stacked bloc... |
1379 |
static inline void __generic_make_request(struct bio *bio) |
1da177e4c Linux-2.6.12-rc2 |
1380 |
{ |
165125e1e [BLOCK] Get rid o... |
1381 |
struct request_queue *q; |
5ddfe9691 [PATCH] md: check... |
1382 |
sector_t old_sector; |
1da177e4c Linux-2.6.12-rc2 |
1383 |
int ret, nr_sectors = bio_sectors(bio); |
2056a782f [PATCH] Block que... |
1384 |
dev_t old_dev; |
51fd77bd9 [BLOCK] Don't all... |
1385 |
int err = -EIO; |
1da177e4c Linux-2.6.12-rc2 |
1386 1387 |
might_sleep(); |
1da177e4c Linux-2.6.12-rc2 |
1388 |
|
c07e2b412 block: factor our... |
1389 1390 |
if (bio_check_eod(bio, nr_sectors)) goto end_io; |
1da177e4c Linux-2.6.12-rc2 |
1391 1392 1393 1394 1395 1396 1397 1398 1399 |
/* * Resolve the mapping until finished. (drivers are * still free to implement/resolve their own stacking * by explicitly returning 0) * * NOTE: we don't repeat the blk_size check for each new device. * Stacking drivers are expected to know what they are doing. */ |
5ddfe9691 [PATCH] md: check... |
1400 |
old_sector = -1; |
2056a782f [PATCH] Block que... |
1401 |
old_dev = 0; |
1da177e4c Linux-2.6.12-rc2 |
1402 1403 |
do { char b[BDEVNAME_SIZE]; |
b2c9cd379 fail_make_request... |
1404 |
struct hd_struct *part; |
1da177e4c Linux-2.6.12-rc2 |
1405 1406 |
q = bdev_get_queue(bio->bi_bdev); |
a7384677b block: remove dup... |
1407 |
if (unlikely(!q)) { |
1da177e4c Linux-2.6.12-rc2 |
1408 1409 1410 1411 1412 1413 |
printk(KERN_ERR "generic_make_request: Trying to access " "nonexistent block-device %s (%Lu) ", bdevname(bio->bi_bdev, b), (long long) bio->bi_sector); |
a7384677b block: remove dup... |
1414 |
goto end_io; |
1da177e4c Linux-2.6.12-rc2 |
1415 |
} |
7b6d91dae block: unify flag... |
1416 |
if (unlikely(!(bio->bi_rw & REQ_DISCARD) && |
67efc9258 block: allow larg... |
1417 |
nr_sectors > queue_max_hw_sectors(q))) { |
6728cb0e6 block: make core ... |
1418 1419 |
printk(KERN_ERR "bio too big device %s (%u > %u) ", |
ae03bf639 block: Use access... |
1420 1421 1422 |
bdevname(bio->bi_bdev, b), bio_sectors(bio), queue_max_hw_sectors(q)); |
1da177e4c Linux-2.6.12-rc2 |
1423 1424 |
goto end_io; } |
fde6ad224 [PATCH] blk: bran... |
1425 |
if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) |
1da177e4c Linux-2.6.12-rc2 |
1426 |
goto end_io; |
b2c9cd379 fail_make_request... |
1427 1428 1429 1430 |
part = bio->bi_bdev->bd_part; if (should_fail_request(part, bio->bi_size) || should_fail_request(&part_to_disk(part)->part0, bio->bi_size)) |
c17bb4951 [PATCH] fault-inj... |
1431 |
goto end_io; |
1da177e4c Linux-2.6.12-rc2 |
1432 1433 1434 1435 1436 |
/* * If this device has partitions, remap block n * of partition p to block n+start(p) of the disk. */ blk_partition_remap(bio); |
7ba1ba12e block: Block laye... |
1437 1438 |
if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) goto end_io; |
5ddfe9691 [PATCH] md: check... |
1439 |
if (old_sector != -1) |
d07335e51 block: Rename "bl... |
1440 |
trace_block_bio_remap(q, bio, old_dev, old_sector); |
2056a782f [PATCH] Block que... |
1441 |
|
5ddfe9691 [PATCH] md: check... |
1442 |
old_sector = bio->bi_sector; |
2056a782f [PATCH] Block que... |
1443 |
old_dev = bio->bi_bdev->bd_dev; |
c07e2b412 block: factor our... |
1444 1445 |
if (bio_check_eod(bio, nr_sectors)) goto end_io; |
a7384677b block: remove dup... |
1446 |
|
1e87901e1 block: filter flu... |
1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 |
/* * Filter flush bio's early so that make_request based * drivers without flush support don't have to worry * about them. */ if ((bio->bi_rw & (REQ_FLUSH | REQ_FUA)) && !q->flush_flags) { bio->bi_rw &= ~(REQ_FLUSH | REQ_FUA); if (!nr_sectors) { err = 0; goto end_io; } } |
8d57a98cc block: add secure... |
1459 1460 1461 1462 |
if ((bio->bi_rw & REQ_DISCARD) && (!blk_queue_discard(q) || ((bio->bi_rw & REQ_SECURE) && !blk_queue_secdiscard(q)))) { |
51fd77bd9 [BLOCK] Don't all... |
1463 1464 1465 |
err = -EOPNOTSUPP; goto end_io; } |
5ddfe9691 [PATCH] md: check... |
1466 |
|
f469a7b4d blk-cgroup: Allow... |
1467 1468 |
if (blk_throtl_bio(q, &bio)) goto end_io; |
e43473b7f blkio: Core imple... |
1469 1470 1471 1472 1473 1474 1475 |
/* * If bio = NULL, bio has been throttled and will be submitted * later. */ if (!bio) break; |
01edede41 block: trace bio ... |
1476 |
trace_block_bio_queue(q, bio); |
1da177e4c Linux-2.6.12-rc2 |
1477 1478 |
ret = q->make_request_fn(q, bio); } while (ret); |
a7384677b block: remove dup... |
1479 1480 1481 1482 1483 |
return; end_io: bio_endio(bio, err); |
1da177e4c Linux-2.6.12-rc2 |
1484 |
} |
d89d87965 When stacked bloc... |
1485 1486 1487 |
/* * We only want one ->make_request_fn to be active at a time, * else stack usage with stacked devices could be a problem. |
bddd87c7e blk-core: use BIO... |
1488 |
* So use current->bio_list to keep a list of requests |
d89d87965 When stacked bloc... |
1489 |
* submited by a make_request_fn function. |
bddd87c7e blk-core: use BIO... |
1490 |
* current->bio_list is also used as a flag to say if |
d89d87965 When stacked bloc... |
1491 1492 1493 1494 1495 1496 1497 |
* generic_make_request is currently active in this task or not. * If it is NULL, then no make_request is active. If it is non-NULL, * then a make_request is active, and new requests should be added * at the tail */ void generic_make_request(struct bio *bio) { |
bddd87c7e blk-core: use BIO... |
1498 1499 1500 |
struct bio_list bio_list_on_stack; if (current->bio_list) { |
d89d87965 When stacked bloc... |
1501 |
/* make_request is active */ |
bddd87c7e blk-core: use BIO... |
1502 |
bio_list_add(current->bio_list, bio); |
d89d87965 When stacked bloc... |
1503 1504 1505 1506 1507 1508 1509 |
return; } /* following loop may be a bit non-obvious, and so deserves some * explanation. * Before entering the loop, bio->bi_next is NULL (as all callers * ensure that) so we have a list with a single bio. * We pretend that we have just taken it off a longer list, so |
bddd87c7e blk-core: use BIO... |
1510 1511 |
* we assign bio_list to a pointer to the bio_list_on_stack, * thus initialising the bio_list of new bios to be |
d89d87965 When stacked bloc... |
1512 1513 1514 1515 |
* added. __generic_make_request may indeed add some more bios * through a recursive call to generic_make_request. If it * did, we find a non-NULL value in bio_list and re-enter the loop * from the top. In this case we really did just take the bio |
bddd87c7e blk-core: use BIO... |
1516 1517 |
* of the top of the list (no pretending) and so remove it from * bio_list, and call into __generic_make_request again. |
d89d87965 When stacked bloc... |
1518 1519 1520 1521 1522 1523 |
* * The loop was structured like this to make only one call to * __generic_make_request (which is important as it is large and * inlined) and to keep the structure simple. */ BUG_ON(bio->bi_next); |
bddd87c7e blk-core: use BIO... |
1524 1525 |
bio_list_init(&bio_list_on_stack); current->bio_list = &bio_list_on_stack; |
d89d87965 When stacked bloc... |
1526 |
do { |
d89d87965 When stacked bloc... |
1527 |
__generic_make_request(bio); |
bddd87c7e blk-core: use BIO... |
1528 |
bio = bio_list_pop(current->bio_list); |
d89d87965 When stacked bloc... |
1529 |
} while (bio); |
bddd87c7e blk-core: use BIO... |
1530 |
current->bio_list = NULL; /* deactivate */ |
d89d87965 When stacked bloc... |
1531 |
} |
1da177e4c Linux-2.6.12-rc2 |
1532 1533 1534 |
EXPORT_SYMBOL(generic_make_request); /** |
710027a48 Add some block/ s... |
1535 |
* submit_bio - submit a bio to the block device layer for I/O |
1da177e4c Linux-2.6.12-rc2 |
1536 1537 1538 1539 1540 |
* @rw: whether to %READ or %WRITE, or maybe to %READA (read ahead) * @bio: The &struct bio which describes the I/O * * submit_bio() is very similar in purpose to generic_make_request(), and * uses that function to do most of the work. Both are fairly rough |
710027a48 Add some block/ s... |
1541 |
* interfaces; @bio must be presetup and ready for I/O. |
1da177e4c Linux-2.6.12-rc2 |
1542 1543 1544 1545 1546 |
* */ void submit_bio(int rw, struct bio *bio) { int count = bio_sectors(bio); |
22e2c507c [PATCH] Update cf... |
1547 |
bio->bi_rw |= rw; |
1da177e4c Linux-2.6.12-rc2 |
1548 |
|
bf2de6f5a block: Initial su... |
1549 1550 1551 1552 |
/* * If it's a regular read/write or a barrier with data attached, * go through the normal accounting stuff before submission. */ |
3ffb52e73 block: fixup miss... |
1553 |
if (bio_has_data(bio) && !(rw & REQ_DISCARD)) { |
bf2de6f5a block: Initial su... |
1554 1555 1556 1557 1558 1559 1560 1561 1562 |
if (rw & WRITE) { count_vm_events(PGPGOUT, count); } else { task_io_account_read(bio->bi_size); count_vm_events(PGPGIN, count); } if (unlikely(block_dump)) { char b[BDEVNAME_SIZE]; |
8dcbdc742 block: block_dump... |
1563 1564 |
printk(KERN_DEBUG "%s(%d): %s block %Lu on %s (%u sectors) ", |
ba25f9dcc Use helpers to ob... |
1565 |
current->comm, task_pid_nr(current), |
bf2de6f5a block: Initial su... |
1566 1567 |
(rw & WRITE) ? "WRITE" : "READ", (unsigned long long)bio->bi_sector, |
8dcbdc742 block: block_dump... |
1568 1569 |
bdevname(bio->bi_bdev, b), count); |
bf2de6f5a block: Initial su... |
1570 |
} |
1da177e4c Linux-2.6.12-rc2 |
1571 1572 1573 1574 |
} generic_make_request(bio); } |
1da177e4c Linux-2.6.12-rc2 |
1575 |
EXPORT_SYMBOL(submit_bio); |
3bcddeac1 blk_end_request: ... |
1576 |
/** |
82124d603 block: add reques... |
1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 |
* blk_rq_check_limits - Helper function to check a request for the queue limit * @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 @q. * Since the block layer and the underlying device driver trust @rq * after it is inserted to @q, it should be checked against @q before * the insertion using this generic function. * * This function should also be useful for request stacking drivers |
eef35c2d4 Fix spelling fuct... |
1589 |
* in some cases below, so export this function. |
82124d603 block: add reques... |
1590 1591 1592 1593 1594 1595 1596 1597 1598 |
* Request stacking drivers like request-based dm may change the queue * limits while requests are in the queue (e.g. dm's table swapping). * Such request stacking drivers should check those requests agaist * the new queue limits again when they dispatch those requests, * although such checkings are also done against the old queue limits * when submitting requests. */ int blk_rq_check_limits(struct request_queue *q, struct request *rq) { |
3383977fa block: update req... |
1599 1600 |
if (rq->cmd_flags & REQ_DISCARD) return 0; |
ae03bf639 block: Use access... |
1601 1602 |
if (blk_rq_sectors(rq) > queue_max_sectors(q) || blk_rq_bytes(rq) > queue_max_hw_sectors(q) << 9) { |
82124d603 block: add reques... |
1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 |
printk(KERN_ERR "%s: over max size limit. ", __func__); return -EIO; } /* * queue's settings related to segment counting like q->bounce_pfn * may differ from that of other stacking queues. * Recalculate it to check the request correctly on this queue's * limitation. */ blk_recalc_rq_segments(rq); |
8a78362c4 block: Consolidat... |
1615 |
if (rq->nr_phys_segments > queue_max_segments(q)) { |
82124d603 block: add reques... |
1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 |
printk(KERN_ERR "%s: over max segments limit. ", __func__); return -EIO; } return 0; } EXPORT_SYMBOL_GPL(blk_rq_check_limits); /** * blk_insert_cloned_request - Helper for stacking drivers to submit a request * @q: the queue to submit the request * @rq: the request being queued */ int blk_insert_cloned_request(struct request_queue *q, struct request *rq) { unsigned long flags; |
4853abaae block: fix flush ... |
1633 |
int where = ELEVATOR_INSERT_BACK; |
82124d603 block: add reques... |
1634 1635 1636 |
if (blk_rq_check_limits(q, rq)) return -EIO; |
b2c9cd379 fail_make_request... |
1637 1638 |
if (rq->rq_disk && should_fail_request(&rq->rq_disk->part0, blk_rq_bytes(rq))) |
82124d603 block: add reques... |
1639 |
return -EIO; |
82124d603 block: add reques... |
1640 1641 1642 1643 1644 1645 1646 1647 |
spin_lock_irqsave(q->queue_lock, flags); /* * Submitting request must be dequeued before calling this function * because it will be linked to another request_queue */ BUG_ON(blk_queued_rq(rq)); |
4853abaae block: fix flush ... |
1648 1649 1650 1651 |
if (rq->cmd_flags & (REQ_FLUSH|REQ_FUA)) where = ELEVATOR_INSERT_FLUSH; add_acct_request(q, rq, where); |
82124d603 block: add reques... |
1652 1653 1654 1655 1656 |
spin_unlock_irqrestore(q->queue_lock, flags); return 0; } EXPORT_SYMBOL_GPL(blk_insert_cloned_request); |
80a761fd3 block: implement ... |
1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 |
/** * blk_rq_err_bytes - determine number of bytes till the next failure boundary * @rq: request to examine * * Description: * A request could be merge of IOs which require different failure * handling. This function determines the number of bytes which * can be failed from the beginning of the request without * crossing into area which need to be retried further. * * Return: * The number of bytes to fail. * * Context: * queue_lock must be held. */ unsigned int blk_rq_err_bytes(const struct request *rq) { unsigned int ff = rq->cmd_flags & REQ_FAILFAST_MASK; unsigned int bytes = 0; struct bio *bio; if (!(rq->cmd_flags & REQ_MIXED_MERGE)) return blk_rq_bytes(rq); /* * Currently the only 'mixing' which can happen is between * different fastfail types. We can safely fail portions * which have all the failfast bits that the first one has - * the ones which are at least as eager to fail as the first * one. */ for (bio = rq->bio; bio; bio = bio->bi_next) { if ((bio->bi_rw & ff) != ff) break; bytes += bio->bi_size; } /* this could lead to infinite loop */ BUG_ON(blk_rq_bytes(rq) && !bytes); return bytes; } EXPORT_SYMBOL_GPL(blk_rq_err_bytes); |
bc58ba946 block: add sysfs ... |
1700 1701 |
static void blk_account_io_completion(struct request *req, unsigned int bytes) { |
c2553b584 block: make blk_d... |
1702 |
if (blk_do_io_stat(req)) { |
bc58ba946 block: add sysfs ... |
1703 1704 1705 1706 1707 |
const int rw = rq_data_dir(req); struct hd_struct *part; int cpu; cpu = part_stat_lock(); |
09e099d4b block: fix accoun... |
1708 |
part = req->part; |
bc58ba946 block: add sysfs ... |
1709 1710 1711 1712 1713 1714 1715 |
part_stat_add(cpu, part, sectors[rw], bytes >> 9); part_stat_unlock(); } } static void blk_account_io_done(struct request *req) { |
bc58ba946 block: add sysfs ... |
1716 |
/* |
dd4c133f3 block: rename bar... |
1717 1718 1719 |
* Account IO completion. flush_rq isn't accounted as a * normal IO on queueing nor completion. Accounting the * containing request is enough. |
bc58ba946 block: add sysfs ... |
1720 |
*/ |
414b4ff5e block: add REQ_FL... |
1721 |
if (blk_do_io_stat(req) && !(req->cmd_flags & REQ_FLUSH_SEQ)) { |
bc58ba946 block: add sysfs ... |
1722 1723 1724 1725 1726 1727 |
unsigned long duration = jiffies - req->start_time; const int rw = rq_data_dir(req); struct hd_struct *part; int cpu; cpu = part_stat_lock(); |
09e099d4b block: fix accoun... |
1728 |
part = req->part; |
bc58ba946 block: add sysfs ... |
1729 1730 1731 1732 |
part_stat_inc(cpu, part, ios[rw]); part_stat_add(cpu, part, ticks[rw], duration); part_round_stats(cpu, part); |
316d315bf block: Seperate r... |
1733 |
part_dec_in_flight(part, rw); |
bc58ba946 block: add sysfs ... |
1734 |
|
6c23a9681 block: add intern... |
1735 |
hd_struct_put(part); |
bc58ba946 block: add sysfs ... |
1736 1737 1738 |
part_stat_unlock(); } } |
53a08807c block: internal d... |
1739 |
/** |
9934c8c04 block: implement ... |
1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 |
* blk_peek_request - peek at the top of a request queue * @q: request queue to peek at * * Description: * Return the request at the top of @q. The returned request * should be started using blk_start_request() before LLD starts * processing it. * * Return: * Pointer to the request at the top of @q if available. Null * otherwise. * * Context: * queue_lock must be held. */ struct request *blk_peek_request(struct request_queue *q) |
158dbda00 block: reorganize... |
1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 |
{ struct request *rq; int ret; while ((rq = __elv_next_request(q)) != NULL) { if (!(rq->cmd_flags & REQ_STARTED)) { /* * This is the first time the device driver * sees this request (possibly after * requeueing). Notify IO scheduler. */ |
33659ebba block: remove wra... |
1767 |
if (rq->cmd_flags & REQ_SORTED) |
158dbda00 block: reorganize... |
1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 |
elv_activate_rq(q, rq); /* * just mark as started even if we don't start * it, a request that has been delayed should * not be passed by new incoming requests */ rq->cmd_flags |= REQ_STARTED; trace_block_rq_issue(q, rq); } if (!q->boundary_rq || q->boundary_rq == rq) { q->end_sector = rq_end_sector(rq); q->boundary_rq = NULL; } if (rq->cmd_flags & REQ_DONTPREP) break; |
2e46e8b27 block: drop reque... |
1786 |
if (q->dma_drain_size && blk_rq_bytes(rq)) { |
158dbda00 block: reorganize... |
1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 |
/* * make sure space for the drain appears we * know we can do this because max_hw_segments * has been adjusted to be one fewer than the * device can handle */ rq->nr_phys_segments++; } if (!q->prep_rq_fn) break; ret = q->prep_rq_fn(q, rq); if (ret == BLKPREP_OK) { break; } else if (ret == BLKPREP_DEFER) { /* * the request may have been (partially) prepped. * we need to keep this request in the front to * avoid resource deadlock. REQ_STARTED will * prevent other fs requests from passing this one. */ |
2e46e8b27 block: drop reque... |
1809 |
if (q->dma_drain_size && blk_rq_bytes(rq) && |
158dbda00 block: reorganize... |
1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 |
!(rq->cmd_flags & REQ_DONTPREP)) { /* * remove the space for the drain we added * so that we don't add it again */ --rq->nr_phys_segments; } rq = NULL; break; } else if (ret == BLKPREP_KILL) { rq->cmd_flags |= REQ_QUIET; |
c143dc903 block: fix an oop... |
1822 1823 1824 1825 1826 |
/* * Mark this request as started so we don't trigger * any debug logic in the end I/O path. */ blk_start_request(rq); |
40cbbb781 block: implement ... |
1827 |
__blk_end_request_all(rq, -EIO); |
158dbda00 block: reorganize... |
1828 1829 1830 1831 1832 1833 1834 1835 1836 |
} else { printk(KERN_ERR "%s: bad return=%d ", __func__, ret); break; } } return rq; } |
9934c8c04 block: implement ... |
1837 |
EXPORT_SYMBOL(blk_peek_request); |
158dbda00 block: reorganize... |
1838 |
|
9934c8c04 block: implement ... |
1839 |
void blk_dequeue_request(struct request *rq) |
158dbda00 block: reorganize... |
1840 |
{ |
9934c8c04 block: implement ... |
1841 |
struct request_queue *q = rq->q; |
158dbda00 block: reorganize... |
1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 |
BUG_ON(list_empty(&rq->queuelist)); BUG_ON(ELV_ON_HASH(rq)); list_del_init(&rq->queuelist); /* * the time frame between a request being removed from the lists * and to it is freed is accounted as io that is in progress at * the driver side. */ |
9195291e5 blkio: Increment ... |
1852 |
if (blk_account_rq(rq)) { |
0a7ae2ff0 block: change the... |
1853 |
q->in_flight[rq_is_sync(rq)]++; |
9195291e5 blkio: Increment ... |
1854 1855 |
set_io_start_time_ns(rq); } |
158dbda00 block: reorganize... |
1856 |
} |
5efccd17c block: reorder re... |
1857 |
/** |
9934c8c04 block: implement ... |
1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 |
* blk_start_request - start request processing on the driver * @req: request to dequeue * * Description: * Dequeue @req and start timeout timer on it. This hands off the * request to the driver. * * Block internal functions which don't want to start timer should * call blk_dequeue_request(). * * Context: * queue_lock must be held. */ void blk_start_request(struct request *req) { blk_dequeue_request(req); /* |
5f49f6317 block: set rq->re... |
1876 1877 |
* We are now handing the request to the hardware, initialize * resid_len to full count and add the timeout handler. |
9934c8c04 block: implement ... |
1878 |
*/ |
5f49f6317 block: set rq->re... |
1879 |
req->resid_len = blk_rq_bytes(req); |
dbb66c4be block: needs to s... |
1880 1881 |
if (unlikely(blk_bidi_rq(req))) req->next_rq->resid_len = blk_rq_bytes(req->next_rq); |
9934c8c04 block: implement ... |
1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 |
blk_add_timer(req); } EXPORT_SYMBOL(blk_start_request); /** * blk_fetch_request - fetch a request from a request queue * @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 @q if available. Null * otherwise. * * Context: * queue_lock must be held. */ struct request *blk_fetch_request(struct request_queue *q) { struct request *rq; rq = blk_peek_request(q); if (rq) blk_start_request(rq); return rq; } EXPORT_SYMBOL(blk_fetch_request); /** |
2e60e0229 block: clean up r... |
1913 |
* blk_update_request - Special helper function for request stacking drivers |
8ebf97560 block: fix kernel... |
1914 |
* @req: the request being processed |
710027a48 Add some block/ s... |
1915 |
* @error: %0 for success, < %0 for error |
8ebf97560 block: fix kernel... |
1916 |
* @nr_bytes: number of bytes to complete @req |
3bcddeac1 blk_end_request: ... |
1917 1918 |
* * Description: |
8ebf97560 block: fix kernel... |
1919 1920 1921 |
* Ends I/O on a number of bytes attached to @req, but doesn't complete * the request structure even if @req doesn't have leftover. * If @req has leftover, sets it up for the next range of segments. |
2e60e0229 block: clean up r... |
1922 1923 1924 1925 1926 1927 1928 |
* * This special helper function is only for request stacking drivers * (e.g. request-based dm) so that they can handle partial completion. * Actual device drivers should use blk_end_request instead. * * Passing the result of blk_rq_bytes() as @nr_bytes guarantees * %false return from this function. |
3bcddeac1 blk_end_request: ... |
1929 1930 |
* * Return: |
2e60e0229 block: clean up r... |
1931 1932 |
* %false - this request doesn't have any more data * %true - this request has more data |
3bcddeac1 blk_end_request: ... |
1933 |
**/ |
2e60e0229 block: clean up r... |
1934 |
bool blk_update_request(struct request *req, int error, unsigned int nr_bytes) |
1da177e4c Linux-2.6.12-rc2 |
1935 |
{ |
5450d3e1d blk_end_request: ... |
1936 |
int total_bytes, bio_nbytes, next_idx = 0; |
1da177e4c Linux-2.6.12-rc2 |
1937 |
struct bio *bio; |
2e60e0229 block: clean up r... |
1938 1939 |
if (!req->bio) return false; |
5f3ea37c7 blktrace: port to... |
1940 |
trace_block_rq_complete(req->q, req); |
2056a782f [PATCH] Block que... |
1941 |
|
1da177e4c Linux-2.6.12-rc2 |
1942 |
/* |
6f41469c6 block: clear req-... |
1943 1944 1945 1946 1947 1948 |
* For fs requests, rq is just carrier of independent bio's * and each partial completion should be handled separately. * Reset per-request error on each partial completion. * * TODO: tj: This is too subtle. It would be better to let * low level drivers do what they see fit. |
1da177e4c Linux-2.6.12-rc2 |
1949 |
*/ |
33659ebba block: remove wra... |
1950 |
if (req->cmd_type == REQ_TYPE_FS) |
1da177e4c Linux-2.6.12-rc2 |
1951 |
req->errors = 0; |
33659ebba block: remove wra... |
1952 1953 |
if (error && req->cmd_type == REQ_TYPE_FS && !(req->cmd_flags & REQ_QUIET)) { |
79775567e [SCSI] block: imp... |
1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 |
char *error_type; switch (error) { case -ENOLINK: error_type = "recoverable transport"; break; case -EREMOTEIO: error_type = "critical target"; break; case -EBADE: error_type = "critical nexus"; break; case -EIO: default: error_type = "I/O"; break; } printk(KERN_ERR "end_request: %s error, dev %s, sector %llu ", error_type, req->rq_disk ? req->rq_disk->disk_name : "?", (unsigned long long)blk_rq_pos(req)); |
1da177e4c Linux-2.6.12-rc2 |
1975 |
} |
bc58ba946 block: add sysfs ... |
1976 |
blk_account_io_completion(req, nr_bytes); |
d72d904a5 [BLOCK] Update re... |
1977 |
|
1da177e4c Linux-2.6.12-rc2 |
1978 1979 1980 1981 1982 1983 1984 |
total_bytes = bio_nbytes = 0; while ((bio = req->bio) != NULL) { int nbytes; if (nr_bytes >= bio->bi_size) { req->bio = bio->bi_next; nbytes = bio->bi_size; |
5bb23a688 Don't decrement b... |
1985 |
req_bio_endio(req, bio, nbytes, error); |
1da177e4c Linux-2.6.12-rc2 |
1986 1987 1988 1989 |
next_idx = 0; bio_nbytes = 0; } else { int idx = bio->bi_idx + next_idx; |
af498d7fa block: fix the bi... |
1990 |
if (unlikely(idx >= bio->bi_vcnt)) { |
1da177e4c Linux-2.6.12-rc2 |
1991 |
blk_dump_rq_flags(req, "__end_that"); |
6728cb0e6 block: make core ... |
1992 1993 |
printk(KERN_ERR "%s: bio idx %d >= vcnt %d ", |
af498d7fa block: fix the bi... |
1994 |
__func__, idx, bio->bi_vcnt); |
1da177e4c Linux-2.6.12-rc2 |
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 |
break; } nbytes = bio_iovec_idx(bio, idx)->bv_len; BIO_BUG_ON(nbytes > bio->bi_size); /* * not a complete bvec done */ if (unlikely(nbytes > nr_bytes)) { bio_nbytes += nr_bytes; total_bytes += nr_bytes; break; } /* * advance to the next vector */ next_idx++; bio_nbytes += nbytes; } total_bytes += nbytes; nr_bytes -= nbytes; |
6728cb0e6 block: make core ... |
2019 2020 |
bio = req->bio; if (bio) { |
1da177e4c Linux-2.6.12-rc2 |
2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 |
/* * end more in this run, or just return 'not-done' */ if (unlikely(nr_bytes <= 0)) break; } } /* * completely done */ |
2e60e0229 block: clean up r... |
2032 2033 2034 2035 2036 2037 |
if (!req->bio) { /* * Reset counters so that the request stacking driver * can find how many bytes remain in the request * later. */ |
a2dec7b36 block: hide reque... |
2038 |
req->__data_len = 0; |
2e60e0229 block: clean up r... |
2039 2040 |
return false; } |
1da177e4c Linux-2.6.12-rc2 |
2041 2042 2043 2044 2045 |
/* * if the request wasn't completed, update state */ if (bio_nbytes) { |
5bb23a688 Don't decrement b... |
2046 |
req_bio_endio(req, bio, bio_nbytes, error); |
1da177e4c Linux-2.6.12-rc2 |
2047 2048 2049 2050 |
bio->bi_idx += next_idx; bio_iovec(bio)->bv_offset += nr_bytes; bio_iovec(bio)->bv_len -= nr_bytes; } |
a2dec7b36 block: hide reque... |
2051 |
req->__data_len -= total_bytes; |
2e46e8b27 block: drop reque... |
2052 2053 2054 |
req->buffer = bio_data(req->bio); /* update sector only for requests with clear definition of sector */ |
33659ebba block: remove wra... |
2055 |
if (req->cmd_type == REQ_TYPE_FS || (req->cmd_flags & REQ_DISCARD)) |
a2dec7b36 block: hide reque... |
2056 |
req->__sector += total_bytes >> 9; |
2e46e8b27 block: drop reque... |
2057 |
|
80a761fd3 block: implement ... |
2058 2059 2060 2061 2062 |
/* mixed attributes always follow the first bio */ if (req->cmd_flags & REQ_MIXED_MERGE) { req->cmd_flags &= ~REQ_FAILFAST_MASK; req->cmd_flags |= req->bio->bi_rw & REQ_FAILFAST_MASK; } |
2e46e8b27 block: drop reque... |
2063 2064 2065 2066 2067 |
/* * If total number of sectors is less than the first segment * size, something has gone terribly wrong. */ if (blk_rq_bytes(req) < blk_rq_cur_bytes(req)) { |
8182924bc block: dump reque... |
2068 |
blk_dump_rq_flags(req, "request botched"); |
a2dec7b36 block: hide reque... |
2069 |
req->__data_len = blk_rq_cur_bytes(req); |
2e46e8b27 block: drop reque... |
2070 2071 2072 |
} /* recalculate the number of segments */ |
1da177e4c Linux-2.6.12-rc2 |
2073 |
blk_recalc_rq_segments(req); |
2e46e8b27 block: drop reque... |
2074 |
|
2e60e0229 block: clean up r... |
2075 |
return true; |
1da177e4c Linux-2.6.12-rc2 |
2076 |
} |
2e60e0229 block: clean up r... |
2077 |
EXPORT_SYMBOL_GPL(blk_update_request); |
1da177e4c Linux-2.6.12-rc2 |
2078 |
|
2e60e0229 block: clean up r... |
2079 2080 2081 |
static bool blk_update_bidi_request(struct request *rq, int error, unsigned int nr_bytes, unsigned int bidi_bytes) |
5efccd17c block: reorder re... |
2082 |
{ |
2e60e0229 block: clean up r... |
2083 2084 |
if (blk_update_request(rq, error, nr_bytes)) return true; |
5efccd17c block: reorder re... |
2085 |
|
2e60e0229 block: clean up r... |
2086 2087 2088 2089 |
/* Bidi request must be completed as a whole */ if (unlikely(blk_bidi_rq(rq)) && blk_update_request(rq->next_rq, error, bidi_bytes)) return true; |
5efccd17c block: reorder re... |
2090 |
|
e2e1a148b block: add sysfs ... |
2091 2092 |
if (blk_queue_add_random(rq->q)) add_disk_randomness(rq->rq_disk); |
2e60e0229 block: clean up r... |
2093 2094 |
return false; |
1da177e4c Linux-2.6.12-rc2 |
2095 |
} |
28018c242 block: implement ... |
2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 |
/** * blk_unprep_request - unprepare a request * @req: the request * * This function makes a request ready for complete resubmission (or * completion). It happens only after all error handling is complete, * so represents the appropriate moment to deallocate any resources * that were allocated to the request in the prep_rq_fn. The queue * lock is held when calling this. */ void blk_unprep_request(struct request *req) { struct request_queue *q = req->q; req->cmd_flags &= ~REQ_DONTPREP; if (q->unprep_rq_fn) q->unprep_rq_fn(q, req); } EXPORT_SYMBOL_GPL(blk_unprep_request); |
1da177e4c Linux-2.6.12-rc2 |
2115 2116 2117 |
/* * queue lock must be held */ |
2e60e0229 block: clean up r... |
2118 |
static void blk_finish_request(struct request *req, int error) |
1da177e4c Linux-2.6.12-rc2 |
2119 |
{ |
b8286239d blk_end_request: ... |
2120 2121 |
if (blk_rq_tagged(req)) blk_queue_end_tag(req->q, req); |
ba396a6c1 block: fix oops w... |
2122 |
BUG_ON(blk_queued_rq(req)); |
1da177e4c Linux-2.6.12-rc2 |
2123 |
|
33659ebba block: remove wra... |
2124 |
if (unlikely(laptop_mode) && req->cmd_type == REQ_TYPE_FS) |
31373d09d laptop-mode: Make... |
2125 |
laptop_io_completion(&req->q->backing_dev_info); |
1da177e4c Linux-2.6.12-rc2 |
2126 |
|
e78042e5b blk: move blk_del... |
2127 |
blk_delete_timer(req); |
28018c242 block: implement ... |
2128 2129 |
if (req->cmd_flags & REQ_DONTPREP) blk_unprep_request(req); |
bc58ba946 block: add sysfs ... |
2130 |
blk_account_io_done(req); |
b8286239d blk_end_request: ... |
2131 |
|
1da177e4c Linux-2.6.12-rc2 |
2132 |
if (req->end_io) |
8ffdc6550 [BLOCK] add @upto... |
2133 |
req->end_io(req, error); |
b8286239d blk_end_request: ... |
2134 2135 2136 |
else { if (blk_bidi_rq(req)) __blk_put_request(req->next_rq->q, req->next_rq); |
1da177e4c Linux-2.6.12-rc2 |
2137 |
__blk_put_request(req->q, req); |
b8286239d blk_end_request: ... |
2138 |
} |
1da177e4c Linux-2.6.12-rc2 |
2139 |
} |
3b11313a6 blk_end_request: ... |
2140 |
/** |
2e60e0229 block: clean up r... |
2141 2142 2143 2144 2145 |
* blk_end_bidi_request - Complete a bidi request * @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 |
a0cd12854 block: add end_qu... |
2146 2147 |
* * Description: |
e3a04fe34 blk_end_request: ... |
2148 |
* Ends I/O on a number of bytes attached to @rq and @rq->next_rq. |
2e60e0229 block: clean up r... |
2149 2150 2151 |
* Drivers that supports bidi can safely call this member for any * type of request, bidi or uni. In the later case @bidi_bytes is * just ignored. |
336cdb400 blk_end_request: ... |
2152 2153 |
* * Return: |
2e60e0229 block: clean up r... |
2154 2155 |
* %false - we are done with this request * %true - still buffers pending for this request |
a0cd12854 block: add end_qu... |
2156 |
**/ |
b1f744937 block: move compl... |
2157 |
static bool blk_end_bidi_request(struct request *rq, int error, |
32fab448e block: add reques... |
2158 2159 |
unsigned int nr_bytes, unsigned int bidi_bytes) { |
336cdb400 blk_end_request: ... |
2160 |
struct request_queue *q = rq->q; |
2e60e0229 block: clean up r... |
2161 |
unsigned long flags; |
32fab448e block: add reques... |
2162 |
|
2e60e0229 block: clean up r... |
2163 2164 |
if (blk_update_bidi_request(rq, error, nr_bytes, bidi_bytes)) return true; |
32fab448e block: add reques... |
2165 |
|
336cdb400 blk_end_request: ... |
2166 |
spin_lock_irqsave(q->queue_lock, flags); |
2e60e0229 block: clean up r... |
2167 |
blk_finish_request(rq, error); |
336cdb400 blk_end_request: ... |
2168 |
spin_unlock_irqrestore(q->queue_lock, flags); |
2e60e0229 block: clean up r... |
2169 |
return false; |
32fab448e block: add reques... |
2170 |
} |
336cdb400 blk_end_request: ... |
2171 |
/** |
2e60e0229 block: clean up r... |
2172 2173 |
* __blk_end_bidi_request - Complete a bidi request with queue lock held * @rq: the request to complete |
710027a48 Add some block/ s... |
2174 |
* @error: %0 for success, < %0 for error |
e3a04fe34 blk_end_request: ... |
2175 2176 |
* @nr_bytes: number of bytes to complete @rq * @bidi_bytes: number of bytes to complete @rq->next_rq |
336cdb400 blk_end_request: ... |
2177 2178 |
* * Description: |
2e60e0229 block: clean up r... |
2179 2180 |
* Identical to blk_end_bidi_request() except that queue lock is * assumed to be locked on entry and remains so on return. |
336cdb400 blk_end_request: ... |
2181 2182 |
* * Return: |
2e60e0229 block: clean up r... |
2183 2184 |
* %false - we are done with this request * %true - still buffers pending for this request |
336cdb400 blk_end_request: ... |
2185 |
**/ |
4853abaae block: fix flush ... |
2186 |
bool __blk_end_bidi_request(struct request *rq, int error, |
b1f744937 block: move compl... |
2187 |
unsigned int nr_bytes, unsigned int bidi_bytes) |
336cdb400 blk_end_request: ... |
2188 |
{ |
2e60e0229 block: clean up r... |
2189 2190 |
if (blk_update_bidi_request(rq, error, nr_bytes, bidi_bytes)) return true; |
336cdb400 blk_end_request: ... |
2191 |
|
2e60e0229 block: clean up r... |
2192 |
blk_finish_request(rq, error); |
336cdb400 blk_end_request: ... |
2193 |
|
2e60e0229 block: clean up r... |
2194 |
return false; |
336cdb400 blk_end_request: ... |
2195 |
} |
e19a3ab05 blk_end_request: ... |
2196 2197 2198 2199 |
/** * blk_end_request - Helper function for drivers to complete the request. * @rq: the request being processed |
710027a48 Add some block/ s... |
2200 |
* @error: %0 for success, < %0 for error |
e19a3ab05 blk_end_request: ... |
2201 2202 2203 2204 2205 2206 2207 |
* @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 for the next range of segments. * * Return: |
b1f744937 block: move compl... |
2208 2209 |
* %false - we are done with this request * %true - still buffers pending for this request |
e19a3ab05 blk_end_request: ... |
2210 |
**/ |
b1f744937 block: move compl... |
2211 |
bool blk_end_request(struct request *rq, int error, unsigned int nr_bytes) |
e19a3ab05 blk_end_request: ... |
2212 |
{ |
b1f744937 block: move compl... |
2213 |
return blk_end_bidi_request(rq, error, nr_bytes, 0); |
e19a3ab05 blk_end_request: ... |
2214 |
} |
56ad1740d block: make the e... |
2215 |
EXPORT_SYMBOL(blk_end_request); |
336cdb400 blk_end_request: ... |
2216 2217 |
/** |
b1f744937 block: move compl... |
2218 2219 |
* blk_end_request_all - Helper function for drives to finish the request. * @rq: the request to finish |
8ebf97560 block: fix kernel... |
2220 |
* @error: %0 for success, < %0 for error |
336cdb400 blk_end_request: ... |
2221 2222 |
* * Description: |
b1f744937 block: move compl... |
2223 2224 2225 |
* Completely finish @rq. */ void blk_end_request_all(struct request *rq, int error) |
336cdb400 blk_end_request: ... |
2226 |
{ |
b1f744937 block: move compl... |
2227 2228 |
bool pending; unsigned int bidi_bytes = 0; |
336cdb400 blk_end_request: ... |
2229 |
|
b1f744937 block: move compl... |
2230 2231 |
if (unlikely(blk_bidi_rq(rq))) bidi_bytes = blk_rq_bytes(rq->next_rq); |
336cdb400 blk_end_request: ... |
2232 |
|
b1f744937 block: move compl... |
2233 2234 2235 |
pending = blk_end_bidi_request(rq, error, blk_rq_bytes(rq), bidi_bytes); BUG_ON(pending); } |
56ad1740d block: make the e... |
2236 |
EXPORT_SYMBOL(blk_end_request_all); |
336cdb400 blk_end_request: ... |
2237 |
|
b1f744937 block: move compl... |
2238 2239 2240 |
/** * blk_end_request_cur - Helper function to finish the current request chunk. * @rq: the request to finish the current chunk for |
8ebf97560 block: fix kernel... |
2241 |
* @error: %0 for success, < %0 for error |
b1f744937 block: move compl... |
2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 |
* * Description: * Complete the current consecutively mapped chunk from @rq. * * Return: * %false - we are done with this request * %true - still buffers pending for this request */ bool blk_end_request_cur(struct request *rq, int error) { return blk_end_request(rq, error, blk_rq_cur_bytes(rq)); |
336cdb400 blk_end_request: ... |
2253 |
} |
56ad1740d block: make the e... |
2254 |
EXPORT_SYMBOL(blk_end_request_cur); |
336cdb400 blk_end_request: ... |
2255 |
|
e19a3ab05 blk_end_request: ... |
2256 |
/** |
80a761fd3 block: implement ... |
2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 |
* blk_end_request_err - Finish a request till the next failure boundary. * @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 this request */ bool blk_end_request_err(struct request *rq, int error) { WARN_ON(error >= 0); return blk_end_request(rq, error, blk_rq_err_bytes(rq)); } EXPORT_SYMBOL_GPL(blk_end_request_err); /** |
b1f744937 block: move compl... |
2276 2277 2278 2279 |
* __blk_end_request - Helper function for drivers to complete the request. * @rq: the request being processed * @error: %0 for success, < %0 for error * @nr_bytes: number of bytes to complete |
e3a04fe34 blk_end_request: ... |
2280 2281 |
* * Description: |
b1f744937 block: move compl... |
2282 |
* Must be called with queue lock held unlike blk_end_request(). |
e3a04fe34 blk_end_request: ... |
2283 2284 |
* * Return: |
b1f744937 block: move compl... |
2285 2286 |
* %false - we are done with this request * %true - still buffers pending for this request |
e3a04fe34 blk_end_request: ... |
2287 |
**/ |
b1f744937 block: move compl... |
2288 |
bool __blk_end_request(struct request *rq, int error, unsigned int nr_bytes) |
e3a04fe34 blk_end_request: ... |
2289 |
{ |
b1f744937 block: move compl... |
2290 |
return __blk_end_bidi_request(rq, error, nr_bytes, 0); |
e3a04fe34 blk_end_request: ... |
2291 |
} |
56ad1740d block: make the e... |
2292 |
EXPORT_SYMBOL(__blk_end_request); |
e3a04fe34 blk_end_request: ... |
2293 2294 |
/** |
b1f744937 block: move compl... |
2295 2296 |
* __blk_end_request_all - Helper function for drives to finish the request. * @rq: the request to finish |
8ebf97560 block: fix kernel... |
2297 |
* @error: %0 for success, < %0 for error |
32fab448e block: add reques... |
2298 2299 |
* * Description: |
b1f744937 block: move compl... |
2300 |
* Completely finish @rq. Must be called with queue lock held. |
32fab448e block: add reques... |
2301 |
*/ |
b1f744937 block: move compl... |
2302 |
void __blk_end_request_all(struct request *rq, int error) |
32fab448e block: add reques... |
2303 |
{ |
b1f744937 block: move compl... |
2304 2305 2306 2307 2308 2309 2310 2311 |
bool pending; unsigned int bidi_bytes = 0; if (unlikely(blk_bidi_rq(rq))) bidi_bytes = blk_rq_bytes(rq->next_rq); pending = __blk_end_bidi_request(rq, error, blk_rq_bytes(rq), bidi_bytes); BUG_ON(pending); |
32fab448e block: add reques... |
2312 |
} |
56ad1740d block: make the e... |
2313 |
EXPORT_SYMBOL(__blk_end_request_all); |
32fab448e block: add reques... |
2314 2315 |
/** |
b1f744937 block: move compl... |
2316 2317 |
* __blk_end_request_cur - Helper function to finish the current request chunk. * @rq: the request to finish the current chunk for |
8ebf97560 block: fix kernel... |
2318 |
* @error: %0 for success, < %0 for error |
e19a3ab05 blk_end_request: ... |
2319 2320 |
* * Description: |
b1f744937 block: move compl... |
2321 2322 |
* Complete the current consecutively mapped chunk from @rq. Must * be called with queue lock held. |
e19a3ab05 blk_end_request: ... |
2323 2324 |
* * Return: |
b1f744937 block: move compl... |
2325 2326 2327 2328 |
* %false - we are done with this request * %true - still buffers pending for this request */ bool __blk_end_request_cur(struct request *rq, int error) |
e19a3ab05 blk_end_request: ... |
2329 |
{ |
b1f744937 block: move compl... |
2330 |
return __blk_end_request(rq, error, blk_rq_cur_bytes(rq)); |
e19a3ab05 blk_end_request: ... |
2331 |
} |
56ad1740d block: make the e... |
2332 |
EXPORT_SYMBOL(__blk_end_request_cur); |
e19a3ab05 blk_end_request: ... |
2333 |
|
80a761fd3 block: implement ... |
2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 |
/** * __blk_end_request_err - Finish a request till the next failure boundary. * @rq: the request to finish till the next failure boundary for * @error: must be negative errno * * Description: * Complete @rq till the next failure boundary. Must be called * with queue lock held. * * Return: * %false - we are done with this request * %true - still buffers pending for this request */ bool __blk_end_request_err(struct request *rq, int error) { WARN_ON(error >= 0); return __blk_end_request(rq, error, blk_rq_err_bytes(rq)); } EXPORT_SYMBOL_GPL(__blk_end_request_err); |
86db1e297 block: continue l... |
2353 2354 |
void blk_rq_bio_prep(struct request_queue *q, struct request *rq, struct bio *bio) |
1da177e4c Linux-2.6.12-rc2 |
2355 |
{ |
a82afdfcb block: use the sa... |
2356 |
/* Bit 0 (R/W) is identical in rq->cmd_flags and bio->bi_rw */ |
7b6d91dae block: unify flag... |
2357 |
rq->cmd_flags |= bio->bi_rw & REQ_WRITE; |
1da177e4c Linux-2.6.12-rc2 |
2358 |
|
fb2dce862 Add 'discard' req... |
2359 2360 |
if (bio_has_data(bio)) { rq->nr_phys_segments = bio_phys_segments(q, bio); |
fb2dce862 Add 'discard' req... |
2361 2362 |
rq->buffer = bio_data(bio); } |
a2dec7b36 block: hide reque... |
2363 |
rq->__data_len = bio->bi_size; |
1da177e4c Linux-2.6.12-rc2 |
2364 |
rq->bio = rq->biotail = bio; |
1da177e4c Linux-2.6.12-rc2 |
2365 |
|
66846572b Stop exporting bl... |
2366 2367 2368 |
if (bio->bi_bdev) rq->rq_disk = bio->bi_bdev->bd_disk; } |
1da177e4c Linux-2.6.12-rc2 |
2369 |
|
2d4dc890b block: add helper... |
2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 |
#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE /** * rq_flush_dcache_pages - Helper function to flush all pages in a request * @rq: the request to be flushed * * Description: * Flush all pages in @rq. */ void rq_flush_dcache_pages(struct request *rq) { struct req_iterator iter; struct bio_vec *bvec; rq_for_each_segment(bvec, rq, iter) flush_dcache_page(bvec->bv_page); } EXPORT_SYMBOL_GPL(rq_flush_dcache_pages); #endif |
ef9e3facd block: add lld bu... |
2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 |
/** * blk_lld_busy - Check if underlying low-level drivers of a device are busy * @q : the queue of the device being checked * * Description: * Check if underlying low-level drivers of a device are busy. * If the drivers want to export their busy state, they must set own * exporting function using blk_queue_lld_busy() first. * * Basically, this function is used only by request stacking drivers * to stop dispatching requests to underlying devices when underlying * devices are busy. This behavior helps more I/O merging on the queue * of the request stacking driver and prevents I/O throughput regression * on burst I/O load. * * Return: * 0 - Not busy (The request stacking driver should dispatch request) * 1 - Busy (The request stacking driver should stop dispatching request) */ int blk_lld_busy(struct request_queue *q) { if (q->lld_busy_fn) return q->lld_busy_fn(q); return 0; } EXPORT_SYMBOL_GPL(blk_lld_busy); |
b0fd271d5 block: add reques... |
2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 |
/** * blk_rq_unprep_clone - Helper function to free all bios in a cloned request * @rq: the clone request to be cleaned up * * Description: * Free all bios in @rq for a cloned request. */ void blk_rq_unprep_clone(struct request *rq) { struct bio *bio; while ((bio = rq->bio) != NULL) { rq->bio = bio->bi_next; bio_put(bio); } } EXPORT_SYMBOL_GPL(blk_rq_unprep_clone); /* * Copy attributes of the original request to the clone request. * The actual data parts (e.g. ->cmd, ->buffer, ->sense) are not copied. */ static void __blk_rq_prep_clone(struct request *dst, struct request *src) { dst->cpu = src->cpu; |
3a2edd0d6 block: make __blk... |
2441 |
dst->cmd_flags = (src->cmd_flags & REQ_CLONE_MASK) | REQ_NOMERGE; |
b0fd271d5 block: add reques... |
2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 |
dst->cmd_type = src->cmd_type; dst->__sector = blk_rq_pos(src); dst->__data_len = blk_rq_bytes(src); dst->nr_phys_segments = src->nr_phys_segments; dst->ioprio = src->ioprio; dst->extra_len = src->extra_len; } /** * blk_rq_prep_clone - Helper function to setup clone request * @rq: the request to be setup * @rq_src: original request to be cloned * @bs: bio_set that bios for clone are allocated from * @gfp_mask: memory allocation mask for bio * @bio_ctr: setup function to be called for each clone bio. * Returns %0 for success, non %0 for failure. * @data: private data to be passed to @bio_ctr * * Description: * Clones bios in @rq_src to @rq, and copies attributes of @rq_src to @rq. * The actual data parts of @rq_src (e.g. ->cmd, ->buffer, ->sense) * are not copied, and copying such parts is the caller's responsibility. * Also, pages which the original bios are pointing to are not copied * and the cloned bios just point same pages. * So cloned bios must be completed before original bios, which means * the caller must complete @rq before @rq_src. */ int blk_rq_prep_clone(struct request *rq, struct request *rq_src, struct bio_set *bs, gfp_t gfp_mask, int (*bio_ctr)(struct bio *, struct bio *, void *), void *data) { struct bio *bio, *bio_src; if (!bs) bs = fs_bio_set; blk_rq_init(NULL, rq); __rq_for_each_bio(bio_src, rq_src) { bio = bio_alloc_bioset(gfp_mask, bio_src->bi_max_vecs, bs); if (!bio) goto free_and_out; __bio_clone(bio, bio_src); if (bio_integrity(bio_src) && |
7878cba9f block: Create bip... |
2489 |
bio_integrity_clone(bio, bio_src, gfp_mask, bs)) |
b0fd271d5 block: add reques... |
2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 |
goto free_and_out; if (bio_ctr && bio_ctr(bio, bio_src, data)) goto free_and_out; if (rq->bio) { rq->biotail->bi_next = bio; rq->biotail = bio; } else rq->bio = rq->biotail = bio; } __blk_rq_prep_clone(rq, rq_src); return 0; free_and_out: if (bio) bio_free(bio, bs); blk_rq_unprep_clone(rq); return -ENOMEM; } EXPORT_SYMBOL_GPL(blk_rq_prep_clone); |
18887ad91 block: make kbloc... |
2514 |
int kblockd_schedule_work(struct request_queue *q, struct work_struct *work) |
1da177e4c Linux-2.6.12-rc2 |
2515 2516 2517 |
{ return queue_work(kblockd_workqueue, work); } |
1da177e4c Linux-2.6.12-rc2 |
2518 |
EXPORT_SYMBOL(kblockd_schedule_work); |
e43473b7f blkio: Core imple... |
2519 2520 2521 2522 2523 2524 |
int kblockd_schedule_delayed_work(struct request_queue *q, struct delayed_work *dwork, unsigned long delay) { return queue_delayed_work(kblockd_workqueue, dwork, delay); } EXPORT_SYMBOL(kblockd_schedule_delayed_work); |
73c101011 block: initial pa... |
2525 2526 2527 2528 2529 2530 2531 2532 |
#define PLUG_MAGIC 0x91827364 void blk_start_plug(struct blk_plug *plug) { struct task_struct *tsk = current; plug->magic = PLUG_MAGIC; INIT_LIST_HEAD(&plug->list); |
048c9374a block: Enhance ne... |
2533 |
INIT_LIST_HEAD(&plug->cb_list); |
73c101011 block: initial pa... |
2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 |
plug->should_sort = 0; /* * If this is a nested plug, don't actually assign it. It will be * flushed on its own. */ if (!tsk->plug) { /* * Store ordering should not be needed here, since a potential * preempt will imply a full memory barrier */ tsk->plug = plug; } } EXPORT_SYMBOL(blk_start_plug); static int plug_rq_cmp(void *priv, struct list_head *a, struct list_head *b) { struct request *rqa = container_of(a, struct request, queuelist); struct request *rqb = container_of(b, struct request, queuelist); |
f83e82618 block: fix reques... |
2554 |
return !(rqa->q <= rqb->q); |
73c101011 block: initial pa... |
2555 |
} |
49cac01e1 block: make unplu... |
2556 2557 2558 2559 2560 2561 |
/* * If 'from_schedule' is true, then postpone the dispatch of requests * until a safe kblockd context. We due this to avoid accidental big * additional stack usage in driver dispatch, in places where the originally * plugger did not intend it. */ |
f6603783f block: only force... |
2562 |
static void queue_unplugged(struct request_queue *q, unsigned int depth, |
49cac01e1 block: make unplu... |
2563 |
bool from_schedule) |
99e22598e block: drop queue... |
2564 |
__releases(q->queue_lock) |
94b5eb28b block: fixup bloc... |
2565 |
{ |
49cac01e1 block: make unplu... |
2566 |
trace_block_unplug(q, depth, !from_schedule); |
99e22598e block: drop queue... |
2567 2568 2569 2570 2571 2572 2573 2574 |
/* * If we are punting this to kblockd, then we can safely drop * the queue_lock before waking kblockd (which needs to take * this lock). */ if (from_schedule) { spin_unlock(q->queue_lock); |
24ecfbe27 block: add blk_ru... |
2575 |
blk_run_queue_async(q); |
99e22598e block: drop queue... |
2576 |
} else { |
24ecfbe27 block: add blk_ru... |
2577 |
__blk_run_queue(q); |
99e22598e block: drop queue... |
2578 2579 |
spin_unlock(q->queue_lock); } |
94b5eb28b block: fixup bloc... |
2580 |
} |
048c9374a block: Enhance ne... |
2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 |
static void flush_plug_callbacks(struct blk_plug *plug) { LIST_HEAD(callbacks); if (list_empty(&plug->cb_list)) return; list_splice_init(&plug->cb_list, &callbacks); while (!list_empty(&callbacks)) { struct blk_plug_cb *cb = list_first_entry(&callbacks, struct blk_plug_cb, list); list_del(&cb->list); cb->callback(cb); } } |
49cac01e1 block: make unplu... |
2598 |
void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule) |
73c101011 block: initial pa... |
2599 2600 2601 2602 |
{ struct request_queue *q; unsigned long flags; struct request *rq; |
109b81296 block: splice plu... |
2603 |
LIST_HEAD(list); |
94b5eb28b block: fixup bloc... |
2604 |
unsigned int depth; |
73c101011 block: initial pa... |
2605 2606 |
BUG_ON(plug->magic != PLUG_MAGIC); |
048c9374a block: Enhance ne... |
2607 |
flush_plug_callbacks(plug); |
73c101011 block: initial pa... |
2608 2609 |
if (list_empty(&plug->list)) return; |
109b81296 block: splice plu... |
2610 2611 2612 2613 2614 2615 |
list_splice_init(&plug->list, &list); if (plug->should_sort) { list_sort(NULL, &list, plug_rq_cmp); plug->should_sort = 0; } |
73c101011 block: initial pa... |
2616 2617 |
q = NULL; |
94b5eb28b block: fixup bloc... |
2618 |
depth = 0; |
188112722 block: add commen... |
2619 2620 2621 2622 2623 |
/* * Save and disable interrupts here, to avoid doing it for every * queue lock we have to take. */ |
73c101011 block: initial pa... |
2624 |
local_irq_save(flags); |
109b81296 block: splice plu... |
2625 2626 |
while (!list_empty(&list)) { rq = list_entry_rq(list.next); |
73c101011 block: initial pa... |
2627 |
list_del_init(&rq->queuelist); |
73c101011 block: initial pa... |
2628 2629 |
BUG_ON(!rq->q); if (rq->q != q) { |
99e22598e block: drop queue... |
2630 2631 2632 2633 |
/* * This drops the queue lock */ if (q) |
49cac01e1 block: make unplu... |
2634 |
queue_unplugged(q, depth, from_schedule); |
73c101011 block: initial pa... |
2635 |
q = rq->q; |
94b5eb28b block: fixup bloc... |
2636 |
depth = 0; |
73c101011 block: initial pa... |
2637 2638 |
spin_lock(q->queue_lock); } |
73c101011 block: initial pa... |
2639 2640 2641 |
/* * rq is already accounted, so use raw insert */ |
401a18e92 block: fix bug wi... |
2642 2643 2644 2645 |
if (rq->cmd_flags & (REQ_FLUSH | REQ_FUA)) __elv_add_request(q, rq, ELEVATOR_INSERT_FLUSH); else __elv_add_request(q, rq, ELEVATOR_INSERT_SORT_MERGE); |
94b5eb28b block: fixup bloc... |
2646 2647 |
depth++; |
73c101011 block: initial pa... |
2648 |
} |
99e22598e block: drop queue... |
2649 2650 2651 2652 |
/* * This drops the queue lock */ if (q) |
49cac01e1 block: make unplu... |
2653 |
queue_unplugged(q, depth, from_schedule); |
73c101011 block: initial pa... |
2654 |
|
73c101011 block: initial pa... |
2655 2656 |
local_irq_restore(flags); } |
73c101011 block: initial pa... |
2657 2658 2659 |
void blk_finish_plug(struct blk_plug *plug) { |
f6603783f block: only force... |
2660 |
blk_flush_plug_list(plug, false); |
73c101011 block: initial pa... |
2661 |
|
88b996cd0 block: cleanup th... |
2662 2663 |
if (plug == current->plug) current->plug = NULL; |
73c101011 block: initial pa... |
2664 |
} |
88b996cd0 block: cleanup th... |
2665 |
EXPORT_SYMBOL(blk_finish_plug); |
73c101011 block: initial pa... |
2666 |
|
1da177e4c Linux-2.6.12-rc2 |
2667 2668 |
int __init blk_dev_init(void) { |
9eb55b030 block: catch tryi... |
2669 2670 |
BUILD_BUG_ON(__REQ_NR_BITS > 8 * sizeof(((struct request *)0)->cmd_flags)); |
89b90be2d block: make kbloc... |
2671 2672 2673 |
/* used for unplugging and affects IO latency/throughput - HIGHPRI */ kblockd_workqueue = alloc_workqueue("kblockd", WQ_MEM_RECLAIM | WQ_HIGHPRI, 0); |
1da177e4c Linux-2.6.12-rc2 |
2674 2675 2676 2677 2678 |
if (!kblockd_workqueue) panic("Failed to create kblockd "); request_cachep = kmem_cache_create("blkdev_requests", |
20c2df83d mm: Remove slab d... |
2679 |
sizeof(struct request), 0, SLAB_PANIC, NULL); |
1da177e4c Linux-2.6.12-rc2 |
2680 |
|
8324aa91d block: split tag ... |
2681 |
blk_requestq_cachep = kmem_cache_create("blkdev_queue", |
165125e1e [BLOCK] Get rid o... |
2682 |
sizeof(struct request_queue), 0, SLAB_PANIC, NULL); |
1da177e4c Linux-2.6.12-rc2 |
2683 |
|
d38ecf935 io context sharin... |
2684 |
return 0; |
1da177e4c Linux-2.6.12-rc2 |
2685 |
} |