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block/blk-core.c
53.8 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/interrupt.h> #include <linux/cpu.h> |
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#include <linux/blktrace_api.h> |
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#include <linux/fault-inject.h> |
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|
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#include "blk.h" |
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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 DEFINE_PER_CPU(struct list_head, blk_cpu_done); |
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static void drive_stat_acct(struct request *rq, int new_io) { int rw = rq_data_dir(rq); if (!blk_fs_request(rq) || !rq->rq_disk) return; if (!new_io) { |
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__all_stat_inc(rq->rq_disk, merges[rw], rq->sector); |
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} else { |
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struct hd_struct *part = get_part(rq->rq_disk, rq->sector); |
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disk_round_stats(rq->rq_disk); rq->rq_disk->in_flight++; |
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if (part) { part_round_stats(part); part->in_flight++; } |
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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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/* * We can't just memset() the structure, since the allocation path * already stored some information in the request. */ |
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void rq_init(struct request_queue *q, struct request *rq) |
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{ INIT_LIST_HEAD(&rq->queuelist); |
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INIT_LIST_HEAD(&rq->donelist); |
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rq->q = q; rq->sector = rq->hard_sector = (sector_t) -1; rq->nr_sectors = rq->hard_nr_sectors = 0; rq->current_nr_sectors = rq->hard_cur_sectors = 0; |
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rq->bio = rq->biotail = NULL; |
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INIT_HLIST_NODE(&rq->hash); RB_CLEAR_NODE(&rq->rb_node); |
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rq->rq_disk = NULL; rq->nr_phys_segments = 0; rq->nr_hw_segments = 0; |
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rq->ioprio = 0; |
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rq->special = NULL; |
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rq->buffer = NULL; |
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rq->tag = -1; rq->errors = 0; |
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rq->ref_count = 1; |
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rq->cmd_len = 0; memset(rq->cmd, 0, sizeof(rq->cmd)); |
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rq->data_len = 0; |
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rq->extra_len = 0; |
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rq->sense_len = 0; |
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rq->data = NULL; rq->sense = NULL; rq->end_io = NULL; rq->end_io_data = NULL; |
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rq->next_rq = NULL; |
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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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struct request_queue *q = rq->q; |
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|
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if (&q->bar_rq != rq) { 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)) { |
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printk(KERN_ERR "%s: want %u bytes done, %u left ", |
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__FUNCTION__, nbytes, bio->bi_size); nbytes = bio->bi_size; } |
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|
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bio->bi_size -= nbytes; bio->bi_sector += (nbytes >> 9); if (bio->bi_size == 0) |
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bio_endio(bio, error); |
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} else { /* * Okay, this is the barrier request in progress, just * record the error; */ if (error && !q->orderr) q->orderr = 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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printk(KERN_INFO " sector %llu, nr/cnr %lu/%u ", (unsigned long long)rq->sector, rq->nr_sectors, rq->current_nr_sectors); printk(KERN_INFO " bio %p, biotail %p, buffer %p, data %p, len %u ", rq->bio, rq->biotail, rq->buffer, rq->data, rq->data_len); |
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if (blk_pc_request(rq)) { |
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printk(KERN_INFO " cdb: "); |
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for (bit = 0; bit < sizeof(rq->cmd); bit++) printk("%02x ", rq->cmd[bit]); printk(" "); } } |
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EXPORT_SYMBOL(blk_dump_rq_flags); |
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/* * "plug" the device if there are no outstanding requests: this will * force the transfer to start only after we have put all the requests * on the list. * * This is called with interrupts off and no requests on the queue and * with the queue lock held. */ |
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void blk_plug_device(struct request_queue *q) |
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{ WARN_ON(!irqs_disabled()); /* * don't plug a stopped queue, it must be paired with blk_start_queue() * which will restart the queueing */ |
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if (blk_queue_stopped(q)) |
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return; |
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if (!test_and_set_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags)) { |
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mod_timer(&q->unplug_timer, jiffies + q->unplug_delay); |
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blk_add_trace_generic(q, NULL, 0, BLK_TA_PLUG); } |
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} |
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EXPORT_SYMBOL(blk_plug_device); /* * remove the queue from the plugged list, if present. called with * queue lock held and interrupts disabled. */ |
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int blk_remove_plug(struct request_queue *q) |
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{ WARN_ON(!irqs_disabled()); if (!test_and_clear_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags)) return 0; del_timer(&q->unplug_timer); return 1; } |
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EXPORT_SYMBOL(blk_remove_plug); /* * remove the plug and let it rip.. */ |
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void __generic_unplug_device(struct request_queue *q) |
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{ |
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if (unlikely(blk_queue_stopped(q))) |
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return; if (!blk_remove_plug(q)) return; |
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q->request_fn(q); |
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} EXPORT_SYMBOL(__generic_unplug_device); /** * generic_unplug_device - fire a request queue |
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* @q: The &struct request_queue in question |
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* * Description: * Linux uses plugging to build bigger requests queues before letting * the device have at them. If a queue is plugged, the I/O scheduler * is still adding and merging requests on the queue. Once the queue * gets unplugged, the request_fn defined for the queue is invoked and * transfers started. **/ |
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void generic_unplug_device(struct request_queue *q) |
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{ spin_lock_irq(q->queue_lock); __generic_unplug_device(q); spin_unlock_irq(q->queue_lock); } EXPORT_SYMBOL(generic_unplug_device); static void blk_backing_dev_unplug(struct backing_dev_info *bdi, struct page *page) { |
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struct request_queue *q = bdi->unplug_io_data; |
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|
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blk_unplug(q); |
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} |
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void blk_unplug_work(struct work_struct *work) |
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{ |
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struct request_queue *q = container_of(work, struct request_queue, unplug_work); |
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|
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blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_IO, NULL, q->rq.count[READ] + q->rq.count[WRITE]); |
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q->unplug_fn(q); } |
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void blk_unplug_timeout(unsigned long data) |
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{ |
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struct request_queue *q = (struct request_queue *)data; |
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|
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blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_TIMER, NULL, q->rq.count[READ] + q->rq.count[WRITE]); |
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kblockd_schedule_work(&q->unplug_work); } |
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void blk_unplug(struct request_queue *q) { /* * devices don't necessarily have an ->unplug_fn defined */ if (q->unplug_fn) { blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_IO, NULL, q->rq.count[READ] + q->rq.count[WRITE]); q->unplug_fn(q); } } EXPORT_SYMBOL(blk_unplug); |
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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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clear_bit(QUEUE_FLAG_STOPPED, &q->queue_flags); /* * one level of recursion is ok and is much faster than kicking * the unplug handling */ if (!test_and_set_bit(QUEUE_FLAG_REENTER, &q->queue_flags)) { q->request_fn(q); clear_bit(QUEUE_FLAG_REENTER, &q->queue_flags); } else { blk_plug_device(q); kblockd_schedule_work(&q->unplug_work); } } |
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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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{ blk_remove_plug(q); set_bit(QUEUE_FLAG_STOPPED, &q->queue_flags); } 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. * */ void blk_sync_queue(struct request_queue *q) { del_timer_sync(&q->unplug_timer); |
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kblockd_flush_work(&q->unplug_work); |
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} EXPORT_SYMBOL(blk_sync_queue); /** * blk_run_queue - run a single device queue * @q: The queue to run */ void blk_run_queue(struct request_queue *q) { unsigned long flags; spin_lock_irqsave(q->queue_lock, flags); blk_remove_plug(q); |
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/* * Only recurse once to avoid overrunning the stack, let the unplug * handling reinvoke the handler shortly if we already got there. */ if (!elv_queue_empty(q)) { if (!test_and_set_bit(QUEUE_FLAG_REENTER, &q->queue_flags)) { q->request_fn(q); clear_bit(QUEUE_FLAG_REENTER, &q->queue_flags); } else { blk_plug_device(q); kblockd_schedule_work(&q->unplug_work); } } |
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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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void blk_cleanup_queue(struct request_queue *q) |
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{ mutex_lock(&q->sysfs_lock); set_bit(QUEUE_FLAG_DEAD, &q->queue_flags); mutex_unlock(&q->sysfs_lock); if (q->elevator) elevator_exit(q->elevator); 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; rl->count[READ] = rl->count[WRITE] = 0; rl->starved[READ] = rl->starved[WRITE] = 0; |
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rl->elvpriv = 0; |
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init_waitqueue_head(&rl->wait[READ]); init_waitqueue_head(&rl->wait[WRITE]); |
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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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{ |
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return blk_alloc_queue_node(gfp_mask, -1); } EXPORT_SYMBOL(blk_alloc_queue); |
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|
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struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id) |
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{ |
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struct request_queue *q; |
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int err; |
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q = kmem_cache_alloc_node(blk_requestq_cachep, |
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gfp_mask | __GFP_ZERO, node_id); |
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if (!q) return NULL; |
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q->backing_dev_info.unplug_io_fn = blk_backing_dev_unplug; q->backing_dev_info.unplug_io_data = q; err = bdi_init(&q->backing_dev_info); if (err) { |
8324aa91d block: split tag ... |
463 |
kmem_cache_free(blk_requestq_cachep, q); |
e0bf68dde mm: bdi init hooks |
464 465 |
return NULL; } |
1da177e4c Linux-2.6.12-rc2 |
466 |
init_timer(&q->unplug_timer); |
483f4afc4 [PATCH] fix sysfs... |
467 |
|
8324aa91d block: split tag ... |
468 |
kobject_init(&q->kobj, &blk_queue_ktype); |
1da177e4c Linux-2.6.12-rc2 |
469 |
|
483f4afc4 [PATCH] fix sysfs... |
470 |
mutex_init(&q->sysfs_lock); |
1da177e4c Linux-2.6.12-rc2 |
471 472 |
return q; } |
1946089a1 [PATCH] NUMA awar... |
473 |
EXPORT_SYMBOL(blk_alloc_queue_node); |
1da177e4c Linux-2.6.12-rc2 |
474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 |
/** * 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... |
497 498 |
* request queue; this lock will be taken also from interrupt context, so irq * disabling is needed for it. |
1da177e4c Linux-2.6.12-rc2 |
499 500 501 502 503 504 505 506 |
* * Function returns a pointer to the initialized request queue, or NULL if * 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... |
507 |
|
165125e1e [BLOCK] Get rid o... |
508 |
struct request_queue *blk_init_queue(request_fn_proc *rfn, spinlock_t *lock) |
1da177e4c Linux-2.6.12-rc2 |
509 |
{ |
1946089a1 [PATCH] NUMA awar... |
510 511 512 |
return blk_init_queue_node(rfn, lock, -1); } EXPORT_SYMBOL(blk_init_queue); |
165125e1e [BLOCK] Get rid o... |
513 |
struct request_queue * |
1946089a1 [PATCH] NUMA awar... |
514 515 |
blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id) { |
165125e1e [BLOCK] Get rid o... |
516 |
struct request_queue *q = blk_alloc_queue_node(GFP_KERNEL, node_id); |
1da177e4c Linux-2.6.12-rc2 |
517 518 519 |
if (!q) return NULL; |
1946089a1 [PATCH] NUMA awar... |
520 |
q->node = node_id; |
8669aafdb [PATCH] fix doubl... |
521 |
if (blk_init_free_list(q)) { |
8324aa91d block: split tag ... |
522 |
kmem_cache_free(blk_requestq_cachep, q); |
8669aafdb [PATCH] fix doubl... |
523 524 |
return NULL; } |
1da177e4c Linux-2.6.12-rc2 |
525 |
|
152587deb [PATCH] fix NMI l... |
526 527 528 529 530 531 532 533 |
/* * if caller didn't supply a lock, they get per-queue locking with * our embedded lock */ if (!lock) { spin_lock_init(&q->__queue_lock); lock = &q->__queue_lock; } |
1da177e4c Linux-2.6.12-rc2 |
534 |
q->request_fn = rfn; |
1da177e4c Linux-2.6.12-rc2 |
535 536 537 538 539 540 541 542 543 544 545 546 |
q->prep_rq_fn = NULL; q->unplug_fn = generic_unplug_device; q->queue_flags = (1 << QUEUE_FLAG_CLUSTER); q->queue_lock = lock; blk_queue_segment_boundary(q, 0xffffffff); blk_queue_make_request(q, __make_request); blk_queue_max_segment_size(q, MAX_SEGMENT_SIZE); blk_queue_max_hw_segments(q, MAX_HW_SEGMENTS); blk_queue_max_phys_segments(q, MAX_PHYS_SEGMENTS); |
44ec95425 [SCSI] sg: cap re... |
547 |
q->sg_reserved_size = INT_MAX; |
1da177e4c Linux-2.6.12-rc2 |
548 549 550 551 552 553 554 |
/* * all done */ if (!elevator_init(q, NULL)) { blk_queue_congestion_threshold(q); return q; } |
8669aafdb [PATCH] fix doubl... |
555 |
blk_put_queue(q); |
1da177e4c Linux-2.6.12-rc2 |
556 557 |
return NULL; } |
1946089a1 [PATCH] NUMA awar... |
558 |
EXPORT_SYMBOL(blk_init_queue_node); |
1da177e4c Linux-2.6.12-rc2 |
559 |
|
165125e1e [BLOCK] Get rid o... |
560 |
int blk_get_queue(struct request_queue *q) |
1da177e4c Linux-2.6.12-rc2 |
561 |
{ |
fde6ad224 [PATCH] blk: bran... |
562 |
if (likely(!test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) { |
483f4afc4 [PATCH] fix sysfs... |
563 |
kobject_get(&q->kobj); |
1da177e4c Linux-2.6.12-rc2 |
564 565 566 567 568 |
return 0; } return 1; } |
1da177e4c Linux-2.6.12-rc2 |
569 |
|
165125e1e [BLOCK] Get rid o... |
570 |
static inline void blk_free_request(struct request_queue *q, struct request *rq) |
1da177e4c Linux-2.6.12-rc2 |
571 |
{ |
4aff5e233 [PATCH] Split str... |
572 |
if (rq->cmd_flags & REQ_ELVPRIV) |
cb98fc8bb [BLOCK] Reimpleme... |
573 |
elv_put_request(q, rq); |
1da177e4c Linux-2.6.12-rc2 |
574 575 |
mempool_free(rq, q->rq.rq_pool); } |
1ea25ecb7 [PATCH] Audit blo... |
576 |
static struct request * |
165125e1e [BLOCK] Get rid o... |
577 |
blk_alloc_request(struct request_queue *q, int rw, int priv, gfp_t gfp_mask) |
1da177e4c Linux-2.6.12-rc2 |
578 579 580 581 582 583 584 |
{ struct request *rq = mempool_alloc(q->rq.rq_pool, gfp_mask); if (!rq) return NULL; /* |
4aff5e233 [PATCH] Split str... |
585 |
* first three bits are identical in rq->cmd_flags and bio->bi_rw, |
1da177e4c Linux-2.6.12-rc2 |
586 587 |
* see bio.h and blkdev.h */ |
49171e5c6 [PATCH] Remove st... |
588 |
rq->cmd_flags = rw | REQ_ALLOCED; |
1da177e4c Linux-2.6.12-rc2 |
589 |
|
cb98fc8bb [BLOCK] Reimpleme... |
590 |
if (priv) { |
cb78b285c [PATCH] Drop usel... |
591 |
if (unlikely(elv_set_request(q, rq, gfp_mask))) { |
cb98fc8bb [BLOCK] Reimpleme... |
592 593 594 |
mempool_free(rq, q->rq.rq_pool); return NULL; } |
4aff5e233 [PATCH] Split str... |
595 |
rq->cmd_flags |= REQ_ELVPRIV; |
cb98fc8bb [BLOCK] Reimpleme... |
596 |
} |
1da177e4c Linux-2.6.12-rc2 |
597 |
|
cb98fc8bb [BLOCK] Reimpleme... |
598 |
return rq; |
1da177e4c Linux-2.6.12-rc2 |
599 600 601 602 603 604 |
} /* * 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... |
605 |
static inline int ioc_batching(struct request_queue *q, struct io_context *ioc) |
1da177e4c Linux-2.6.12-rc2 |
606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 |
{ 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... |
626 |
static void ioc_set_batching(struct request_queue *q, struct io_context *ioc) |
1da177e4c Linux-2.6.12-rc2 |
627 628 629 630 631 632 633 |
{ if (!ioc || ioc_batching(q, ioc)) return; ioc->nr_batch_requests = q->nr_batching; ioc->last_waited = jiffies; } |
165125e1e [BLOCK] Get rid o... |
634 |
static void __freed_request(struct request_queue *q, int rw) |
1da177e4c Linux-2.6.12-rc2 |
635 636 637 638 |
{ struct request_list *rl = &q->rq; if (rl->count[rw] < queue_congestion_off_threshold(q)) |
79e2de4bc [PATCH] export cl... |
639 |
blk_clear_queue_congested(q, rw); |
1da177e4c Linux-2.6.12-rc2 |
640 641 |
if (rl->count[rw] + 1 <= q->nr_requests) { |
1da177e4c Linux-2.6.12-rc2 |
642 643 644 645 646 647 648 649 650 651 652 |
if (waitqueue_active(&rl->wait[rw])) wake_up(&rl->wait[rw]); blk_clear_queue_full(q, rw); } } /* * A request has just been released. Account for it, update the full and * congestion status, wake up any waiters. Called under q->queue_lock. */ |
165125e1e [BLOCK] Get rid o... |
653 |
static void freed_request(struct request_queue *q, int rw, int priv) |
1da177e4c Linux-2.6.12-rc2 |
654 655 656 657 |
{ struct request_list *rl = &q->rq; rl->count[rw]--; |
cb98fc8bb [BLOCK] Reimpleme... |
658 659 |
if (priv) rl->elvpriv--; |
1da177e4c Linux-2.6.12-rc2 |
660 661 662 663 664 |
__freed_request(q, rw); if (unlikely(rl->starved[rw ^ 1])) __freed_request(q, rw ^ 1); |
1da177e4c Linux-2.6.12-rc2 |
665 666 667 668 |
} #define blkdev_free_rq(list) list_entry((list)->next, struct request, queuelist) /* |
d6344532a [PATCH] blk: redu... |
669 670 671 |
* 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 |
672 |
*/ |
165125e1e [BLOCK] Get rid o... |
673 |
static struct request *get_request(struct request_queue *q, int rw_flags, |
7749a8d42 [PATCH] Propagate... |
674 |
struct bio *bio, gfp_t gfp_mask) |
1da177e4c Linux-2.6.12-rc2 |
675 676 677 |
{ struct request *rq = NULL; struct request_list *rl = &q->rq; |
88ee5ef15 [BLOCK] ll_rw_blk... |
678 |
struct io_context *ioc = NULL; |
7749a8d42 [PATCH] Propagate... |
679 |
const int rw = rw_flags & 0x01; |
88ee5ef15 [BLOCK] ll_rw_blk... |
680 |
int may_queue, priv; |
7749a8d42 [PATCH] Propagate... |
681 |
may_queue = elv_may_queue(q, rw_flags); |
88ee5ef15 [BLOCK] ll_rw_blk... |
682 683 684 685 686 |
if (may_queue == ELV_MQUEUE_NO) goto rq_starved; if (rl->count[rw]+1 >= queue_congestion_on_threshold(q)) { if (rl->count[rw]+1 >= q->nr_requests) { |
b5deef901 [PATCH] Make sure... |
687 |
ioc = current_io_context(GFP_ATOMIC, q->node); |
88ee5ef15 [BLOCK] ll_rw_blk... |
688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 |
/* * 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. */ if (!blk_queue_full(q, rw)) { ioc_set_batching(q, ioc); blk_set_queue_full(q, rw); } 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 |
708 |
} |
79e2de4bc [PATCH] export cl... |
709 |
blk_set_queue_congested(q, rw); |
1da177e4c Linux-2.6.12-rc2 |
710 |
} |
082cf69eb [PATCH] ll_rw_blk... |
711 712 713 714 715 |
/* * 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 */ |
fd782a4a9 [PATCH] Fix get_r... |
716 |
if (rl->count[rw] >= (3 * q->nr_requests / 2)) |
082cf69eb [PATCH] ll_rw_blk... |
717 |
goto out; |
fd782a4a9 [PATCH] Fix get_r... |
718 |
|
1da177e4c Linux-2.6.12-rc2 |
719 720 |
rl->count[rw]++; rl->starved[rw] = 0; |
cb98fc8bb [BLOCK] Reimpleme... |
721 |
|
64521d1a3 [BLOCK] elevator ... |
722 |
priv = !test_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags); |
cb98fc8bb [BLOCK] Reimpleme... |
723 724 |
if (priv) rl->elvpriv++; |
1da177e4c Linux-2.6.12-rc2 |
725 |
spin_unlock_irq(q->queue_lock); |
7749a8d42 [PATCH] Propagate... |
726 |
rq = blk_alloc_request(q, rw_flags, priv, gfp_mask); |
88ee5ef15 [BLOCK] ll_rw_blk... |
727 |
if (unlikely(!rq)) { |
1da177e4c Linux-2.6.12-rc2 |
728 729 730 731 732 733 734 735 |
/* * 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); |
cb98fc8bb [BLOCK] Reimpleme... |
736 |
freed_request(q, rw, priv); |
1da177e4c Linux-2.6.12-rc2 |
737 738 739 740 741 742 743 744 745 746 747 |
/* * 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: if (unlikely(rl->count[rw] == 0)) rl->starved[rw] = 1; |
1da177e4c Linux-2.6.12-rc2 |
748 749 |
goto out; } |
88ee5ef15 [BLOCK] ll_rw_blk... |
750 751 752 753 754 755 |
/* * 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 |
756 757 |
if (ioc_batching(q, ioc)) ioc->nr_batch_requests--; |
6728cb0e6 block: make core ... |
758 |
|
1da177e4c Linux-2.6.12-rc2 |
759 |
rq_init(q, rq); |
2056a782f [PATCH] Block que... |
760 761 |
blk_add_trace_generic(q, bio, rw, BLK_TA_GETRQ); |
1da177e4c Linux-2.6.12-rc2 |
762 |
out: |
1da177e4c Linux-2.6.12-rc2 |
763 764 765 766 767 768 |
return rq; } /* * No available requests for this queue, unplug the device and wait for some * requests to become available. |
d6344532a [PATCH] blk: redu... |
769 770 |
* * Called with q->queue_lock held, and returns with it unlocked. |
1da177e4c Linux-2.6.12-rc2 |
771 |
*/ |
165125e1e [BLOCK] Get rid o... |
772 |
static struct request *get_request_wait(struct request_queue *q, int rw_flags, |
22e2c507c [PATCH] Update cf... |
773 |
struct bio *bio) |
1da177e4c Linux-2.6.12-rc2 |
774 |
{ |
7749a8d42 [PATCH] Propagate... |
775 |
const int rw = rw_flags & 0x01; |
1da177e4c Linux-2.6.12-rc2 |
776 |
struct request *rq; |
7749a8d42 [PATCH] Propagate... |
777 |
rq = get_request(q, rw_flags, bio, GFP_NOIO); |
450991bc1 [PATCH] blk: __ma... |
778 779 |
while (!rq) { DEFINE_WAIT(wait); |
1da177e4c Linux-2.6.12-rc2 |
780 781 782 783 |
struct request_list *rl = &q->rq; prepare_to_wait_exclusive(&rl->wait[rw], &wait, TASK_UNINTERRUPTIBLE); |
7749a8d42 [PATCH] Propagate... |
784 |
rq = get_request(q, rw_flags, bio, GFP_NOIO); |
1da177e4c Linux-2.6.12-rc2 |
785 786 787 |
if (!rq) { struct io_context *ioc; |
2056a782f [PATCH] Block que... |
788 |
blk_add_trace_generic(q, bio, rw, BLK_TA_SLEEPRQ); |
d6344532a [PATCH] blk: redu... |
789 790 |
__generic_unplug_device(q); spin_unlock_irq(q->queue_lock); |
1da177e4c Linux-2.6.12-rc2 |
791 792 793 794 795 796 797 798 |
io_schedule(); /* * 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 */ |
b5deef901 [PATCH] Make sure... |
799 |
ioc = current_io_context(GFP_NOIO, q->node); |
1da177e4c Linux-2.6.12-rc2 |
800 |
ioc_set_batching(q, ioc); |
d6344532a [PATCH] blk: redu... |
801 802 |
spin_lock_irq(q->queue_lock); |
1da177e4c Linux-2.6.12-rc2 |
803 804 |
} finish_wait(&rl->wait[rw], &wait); |
450991bc1 [PATCH] blk: __ma... |
805 |
} |
1da177e4c Linux-2.6.12-rc2 |
806 807 808 |
return rq; } |
165125e1e [BLOCK] Get rid o... |
809 |
struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask) |
1da177e4c Linux-2.6.12-rc2 |
810 811 812 813 |
{ struct request *rq; BUG_ON(rw != READ && rw != WRITE); |
d6344532a [PATCH] blk: redu... |
814 815 |
spin_lock_irq(q->queue_lock); if (gfp_mask & __GFP_WAIT) { |
22e2c507c [PATCH] Update cf... |
816 |
rq = get_request_wait(q, rw, NULL); |
d6344532a [PATCH] blk: redu... |
817 |
} else { |
22e2c507c [PATCH] Update cf... |
818 |
rq = get_request(q, rw, NULL, gfp_mask); |
d6344532a [PATCH] blk: redu... |
819 820 821 822 |
if (!rq) spin_unlock_irq(q->queue_lock); } /* q->queue_lock is unlocked at this point */ |
1da177e4c Linux-2.6.12-rc2 |
823 824 825 |
return rq; } |
1da177e4c Linux-2.6.12-rc2 |
826 827 828 |
EXPORT_SYMBOL(blk_get_request); /** |
dc72ef4ae [PATCH] Add blk_s... |
829 830 831 832 833 834 835 836 837 |
* blk_start_queueing - initiate dispatch of requests to device * @q: request queue to kick into gear * * This is basically a helper to remove the need to know whether a queue * is plugged or not if someone just wants to initiate dispatch of requests * for this queue. * * The queue lock must be held with interrupts disabled. */ |
165125e1e [BLOCK] Get rid o... |
838 |
void blk_start_queueing(struct request_queue *q) |
dc72ef4ae [PATCH] Add blk_s... |
839 840 841 842 843 844 845 846 847 |
{ if (!blk_queue_plugged(q)) q->request_fn(q); else __generic_unplug_device(q); } EXPORT_SYMBOL(blk_start_queueing); /** |
1da177e4c Linux-2.6.12-rc2 |
848 849 850 851 852 853 854 855 856 |
* 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... |
857 |
void blk_requeue_request(struct request_queue *q, struct request *rq) |
1da177e4c Linux-2.6.12-rc2 |
858 |
{ |
2056a782f [PATCH] Block que... |
859 |
blk_add_trace_rq(q, rq, BLK_TA_REQUEUE); |
1da177e4c Linux-2.6.12-rc2 |
860 861 862 863 864 |
if (blk_rq_tagged(rq)) blk_queue_end_tag(q, rq); elv_requeue_request(q, rq); } |
1da177e4c Linux-2.6.12-rc2 |
865 866 867 868 869 870 871 872 |
EXPORT_SYMBOL(blk_requeue_request); /** * blk_insert_request - insert a special request in to a request queue * @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 |
873 874 875 876 877 878 879 880 881 882 883 884 885 |
* * 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 * REQ_SPECIAL in to the corresponding request queue, and letting them be * scheduled for actual execution by the request queue. * * 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... |
886 |
void blk_insert_request(struct request_queue *q, struct request *rq, |
867d1191f [SCSI] remove req... |
887 |
int at_head, void *data) |
1da177e4c Linux-2.6.12-rc2 |
888 |
{ |
867d1191f [SCSI] remove req... |
889 |
int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK; |
1da177e4c Linux-2.6.12-rc2 |
890 891 892 893 894 895 896 |
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... |
897 898 |
rq->cmd_type = REQ_TYPE_SPECIAL; rq->cmd_flags |= REQ_SOFTBARRIER; |
1da177e4c Linux-2.6.12-rc2 |
899 900 901 902 903 904 905 906 |
rq->special = data; spin_lock_irqsave(q->queue_lock, flags); /* * If command is tagged, release the tag */ |
867d1191f [SCSI] remove req... |
907 908 |
if (blk_rq_tagged(rq)) blk_queue_end_tag(q, rq); |
1da177e4c Linux-2.6.12-rc2 |
909 |
|
b238b3d4b block layer: remo... |
910 |
drive_stat_acct(rq, 1); |
867d1191f [SCSI] remove req... |
911 |
__elv_add_request(q, rq, where, 0); |
dc72ef4ae [PATCH] Add blk_s... |
912 |
blk_start_queueing(q); |
1da177e4c Linux-2.6.12-rc2 |
913 914 |
spin_unlock_irqrestore(q->queue_lock, flags); } |
1da177e4c Linux-2.6.12-rc2 |
915 |
EXPORT_SYMBOL(blk_insert_request); |
1da177e4c Linux-2.6.12-rc2 |
916 917 918 919 920 |
/* * add-request adds a request to the linked list. * queue lock is held and interrupts disabled, as we muck with the * request queue list. */ |
6728cb0e6 block: make core ... |
921 |
static inline void add_request(struct request_queue *q, struct request *req) |
1da177e4c Linux-2.6.12-rc2 |
922 |
{ |
b238b3d4b block layer: remo... |
923 |
drive_stat_acct(req, 1); |
1da177e4c Linux-2.6.12-rc2 |
924 |
|
1da177e4c Linux-2.6.12-rc2 |
925 926 927 928 929 930 |
/* * elevator indicated where it wants this request to be * inserted at elevator_merge time */ __elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0); } |
6728cb0e6 block: make core ... |
931 |
|
1da177e4c Linux-2.6.12-rc2 |
932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 |
/* * disk_round_stats() - Round off the performance stats on a struct * disk_stats. * * 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. */ void disk_round_stats(struct gendisk *disk) { unsigned long now = jiffies; |
b2982649c Following the sam... |
950 951 |
if (now == disk->stamp) return; |
1da177e4c Linux-2.6.12-rc2 |
952 |
|
20e5c81fc [patch] remove ge... |
953 954 955 956 957 |
if (disk->in_flight) { __disk_stat_add(disk, time_in_queue, disk->in_flight * (now - disk->stamp)); __disk_stat_add(disk, io_ticks, (now - disk->stamp)); } |
1da177e4c Linux-2.6.12-rc2 |
958 |
disk->stamp = now; |
1da177e4c Linux-2.6.12-rc2 |
959 |
} |
3eaf840e0 [PATCH] device-ma... |
960 |
EXPORT_SYMBOL_GPL(disk_round_stats); |
6f2576af5 Enhanced partitio... |
961 962 963 964 965 966 967 968 969 970 971 972 973 974 |
void part_round_stats(struct hd_struct *part) { unsigned long now = jiffies; if (now == part->stamp) return; if (part->in_flight) { __part_stat_add(part, time_in_queue, part->in_flight * (now - part->stamp)); __part_stat_add(part, io_ticks, (now - part->stamp)); } part->stamp = now; } |
1da177e4c Linux-2.6.12-rc2 |
975 976 977 |
/* * queue lock must be held */ |
165125e1e [BLOCK] Get rid o... |
978 |
void __blk_put_request(struct request_queue *q, struct request *req) |
1da177e4c Linux-2.6.12-rc2 |
979 |
{ |
1da177e4c Linux-2.6.12-rc2 |
980 981 982 983 |
if (unlikely(!q)) return; if (unlikely(--req->ref_count)) return; |
8922e16cf [PATCH] 01/05 Imp... |
984 |
elv_completed_request(q, req); |
1da177e4c Linux-2.6.12-rc2 |
985 986 987 988 |
/* * 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... |
989 |
if (req->cmd_flags & REQ_ALLOCED) { |
1da177e4c Linux-2.6.12-rc2 |
990 |
int rw = rq_data_dir(req); |
4aff5e233 [PATCH] Split str... |
991 |
int priv = req->cmd_flags & REQ_ELVPRIV; |
1da177e4c Linux-2.6.12-rc2 |
992 |
|
1da177e4c Linux-2.6.12-rc2 |
993 |
BUG_ON(!list_empty(&req->queuelist)); |
9817064b6 [PATCH] elevator:... |
994 |
BUG_ON(!hlist_unhashed(&req->hash)); |
1da177e4c Linux-2.6.12-rc2 |
995 996 |
blk_free_request(q, req); |
cb98fc8bb [BLOCK] Reimpleme... |
997 |
freed_request(q, rw, priv); |
1da177e4c Linux-2.6.12-rc2 |
998 999 |
} } |
6e39b69e7 [SCSI] export blk... |
1000 |
EXPORT_SYMBOL_GPL(__blk_put_request); |
1da177e4c Linux-2.6.12-rc2 |
1001 1002 |
void blk_put_request(struct request *req) { |
8922e16cf [PATCH] 01/05 Imp... |
1003 |
unsigned long flags; |
165125e1e [BLOCK] Get rid o... |
1004 |
struct request_queue *q = req->q; |
8922e16cf [PATCH] 01/05 Imp... |
1005 |
|
1da177e4c Linux-2.6.12-rc2 |
1006 |
/* |
8922e16cf [PATCH] 01/05 Imp... |
1007 1008 |
* Gee, IDE calls in w/ NULL q. Fix IDE and remove the * following if (q) test. |
1da177e4c Linux-2.6.12-rc2 |
1009 |
*/ |
8922e16cf [PATCH] 01/05 Imp... |
1010 |
if (q) { |
1da177e4c Linux-2.6.12-rc2 |
1011 1012 1013 1014 1015 |
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 |
1016 |
EXPORT_SYMBOL(blk_put_request); |
86db1e297 block: continue l... |
1017 |
void init_request_from_bio(struct request *req, struct bio *bio) |
52d9e6753 [BLOCK] ll_rw_blk... |
1018 |
{ |
4aff5e233 [PATCH] Split str... |
1019 |
req->cmd_type = REQ_TYPE_FS; |
52d9e6753 [BLOCK] ll_rw_blk... |
1020 1021 1022 1023 1024 |
/* * inherit FAILFAST from bio (for read-ahead, and explicit FAILFAST) */ if (bio_rw_ahead(bio) || bio_failfast(bio)) |
4aff5e233 [PATCH] Split str... |
1025 |
req->cmd_flags |= REQ_FAILFAST; |
52d9e6753 [BLOCK] ll_rw_blk... |
1026 1027 1028 1029 1030 |
/* * REQ_BARRIER implies no merging, but lets make it explicit */ if (unlikely(bio_barrier(bio))) |
4aff5e233 [PATCH] Split str... |
1031 |
req->cmd_flags |= (REQ_HARDBARRIER | REQ_NOMERGE); |
52d9e6753 [BLOCK] ll_rw_blk... |
1032 |
|
b31dc66a5 [PATCH] Kill PF_S... |
1033 |
if (bio_sync(bio)) |
4aff5e233 [PATCH] Split str... |
1034 |
req->cmd_flags |= REQ_RW_SYNC; |
5404bc7a8 [PATCH] Allow fil... |
1035 1036 |
if (bio_rw_meta(bio)) req->cmd_flags |= REQ_RW_META; |
b31dc66a5 [PATCH] Kill PF_S... |
1037 |
|
52d9e6753 [BLOCK] ll_rw_blk... |
1038 1039 |
req->errors = 0; req->hard_sector = req->sector = bio->bi_sector; |
52d9e6753 [BLOCK] ll_rw_blk... |
1040 |
req->ioprio = bio_prio(bio); |
52d9e6753 [BLOCK] ll_rw_blk... |
1041 |
req->start_time = jiffies; |
bc1c56fde Share code betwee... |
1042 |
blk_rq_bio_prep(req->q, req, bio); |
52d9e6753 [BLOCK] ll_rw_blk... |
1043 |
} |
165125e1e [BLOCK] Get rid o... |
1044 |
static int __make_request(struct request_queue *q, struct bio *bio) |
1da177e4c Linux-2.6.12-rc2 |
1045 |
{ |
450991bc1 [PATCH] blk: __ma... |
1046 |
struct request *req; |
51da90fcb [PATCH] ll_rw_blk... |
1047 1048 1049 |
int el_ret, nr_sectors, barrier, err; const unsigned short prio = bio_prio(bio); const int sync = bio_sync(bio); |
7749a8d42 [PATCH] Propagate... |
1050 |
int rw_flags; |
1da177e4c Linux-2.6.12-rc2 |
1051 |
|
1da177e4c Linux-2.6.12-rc2 |
1052 |
nr_sectors = bio_sectors(bio); |
1da177e4c Linux-2.6.12-rc2 |
1053 1054 1055 1056 1057 1058 1059 |
/* * 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); |
1da177e4c Linux-2.6.12-rc2 |
1060 |
barrier = bio_barrier(bio); |
797e7dbbe [BLOCK] reimpleme... |
1061 |
if (unlikely(barrier) && (q->next_ordered == QUEUE_ORDERED_NONE)) { |
1da177e4c Linux-2.6.12-rc2 |
1062 1063 1064 |
err = -EOPNOTSUPP; goto end_io; } |
1da177e4c Linux-2.6.12-rc2 |
1065 |
spin_lock_irq(q->queue_lock); |
450991bc1 [PATCH] blk: __ma... |
1066 |
if (unlikely(barrier) || elv_queue_empty(q)) |
1da177e4c Linux-2.6.12-rc2 |
1067 1068 1069 1070 |
goto get_rq; el_ret = elv_merge(q, &req, bio); switch (el_ret) { |
6728cb0e6 block: make core ... |
1071 1072 |
case ELEVATOR_BACK_MERGE: BUG_ON(!rq_mergeable(req)); |
1da177e4c Linux-2.6.12-rc2 |
1073 |
|
6728cb0e6 block: make core ... |
1074 1075 |
if (!ll_back_merge_fn(q, req, bio)) break; |
1da177e4c Linux-2.6.12-rc2 |
1076 |
|
6728cb0e6 block: make core ... |
1077 |
blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE); |
2056a782f [PATCH] Block que... |
1078 |
|
6728cb0e6 block: make core ... |
1079 1080 1081 1082 1083 1084 1085 1086 |
req->biotail->bi_next = bio; req->biotail = bio; req->nr_sectors = req->hard_nr_sectors += nr_sectors; req->ioprio = ioprio_best(req->ioprio, prio); drive_stat_acct(req, 0); if (!attempt_back_merge(q, req)) elv_merged_request(q, req, el_ret); goto out; |
1da177e4c Linux-2.6.12-rc2 |
1087 |
|
6728cb0e6 block: make core ... |
1088 1089 |
case ELEVATOR_FRONT_MERGE: BUG_ON(!rq_mergeable(req)); |
1da177e4c Linux-2.6.12-rc2 |
1090 |
|
6728cb0e6 block: make core ... |
1091 1092 |
if (!ll_front_merge_fn(q, req, bio)) break; |
1da177e4c Linux-2.6.12-rc2 |
1093 |
|
6728cb0e6 block: make core ... |
1094 |
blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE); |
2056a782f [PATCH] Block que... |
1095 |
|
6728cb0e6 block: make core ... |
1096 1097 |
bio->bi_next = req->bio; req->bio = bio; |
1da177e4c Linux-2.6.12-rc2 |
1098 |
|
6728cb0e6 block: make core ... |
1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 |
/* * 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->current_nr_sectors = bio_cur_sectors(bio); req->hard_cur_sectors = req->current_nr_sectors; req->sector = req->hard_sector = bio->bi_sector; req->nr_sectors = req->hard_nr_sectors += nr_sectors; req->ioprio = ioprio_best(req->ioprio, prio); drive_stat_acct(req, 0); if (!attempt_front_merge(q, req)) elv_merged_request(q, req, el_ret); goto out; /* ELV_NO_MERGE: elevator says don't/can't merge. */ default: ; |
1da177e4c Linux-2.6.12-rc2 |
1118 |
} |
450991bc1 [PATCH] blk: __ma... |
1119 |
get_rq: |
1da177e4c Linux-2.6.12-rc2 |
1120 |
/* |
7749a8d42 [PATCH] Propagate... |
1121 1122 1123 1124 1125 1126 1127 1128 1129 |
* 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) rw_flags |= REQ_RW_SYNC; /* |
450991bc1 [PATCH] blk: __ma... |
1130 |
* Grab a free request. This is might sleep but can not fail. |
d6344532a [PATCH] blk: redu... |
1131 |
* Returns with the queue unlocked. |
450991bc1 [PATCH] blk: __ma... |
1132 |
*/ |
7749a8d42 [PATCH] Propagate... |
1133 |
req = get_request_wait(q, rw_flags, bio); |
d6344532a [PATCH] blk: redu... |
1134 |
|
450991bc1 [PATCH] blk: __ma... |
1135 1136 1137 1138 1139 |
/* * 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 |
1140 |
*/ |
52d9e6753 [BLOCK] ll_rw_blk... |
1141 |
init_request_from_bio(req, bio); |
1da177e4c Linux-2.6.12-rc2 |
1142 |
|
450991bc1 [PATCH] blk: __ma... |
1143 1144 1145 |
spin_lock_irq(q->queue_lock); if (elv_queue_empty(q)) blk_plug_device(q); |
1da177e4c Linux-2.6.12-rc2 |
1146 1147 |
add_request(q, req); out: |
4a534f93b [PATCH] possible ... |
1148 |
if (sync) |
1da177e4c Linux-2.6.12-rc2 |
1149 1150 1151 1152 1153 1154 |
__generic_unplug_device(q); spin_unlock_irq(q->queue_lock); return 0; end_io: |
6712ecf8f Drop 'size' argum... |
1155 |
bio_endio(bio, err); |
1da177e4c Linux-2.6.12-rc2 |
1156 1157 1158 1159 1160 1161 1162 1163 1164 |
return 0; } /* * 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... |
1165 |
if (bio_sectors(bio) && bdev != bdev->bd_contains) { |
1da177e4c Linux-2.6.12-rc2 |
1166 |
struct hd_struct *p = bdev->bd_part; |
1da177e4c Linux-2.6.12-rc2 |
1167 1168 |
bio->bi_sector += p->start_sect; bio->bi_bdev = bdev->bd_contains; |
c7149d6bc Fix remap handlin... |
1169 1170 1171 1172 |
blk_add_trace_remap(bdev_get_queue(bio->bi_bdev), bio, bdev->bd_dev, bio->bi_sector, bio->bi_sector - p->start_sect); |
1da177e4c Linux-2.6.12-rc2 |
1173 1174 |
} } |
1da177e4c Linux-2.6.12-rc2 |
1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 |
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), (long long)(bio->bi_bdev->bd_inode->i_size >> 9)); set_bit(BIO_EOF, &bio->bi_flags); } |
c17bb4951 [PATCH] fault-inj... |
1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 |
#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); static int should_fail_request(struct bio *bio) { if ((bio->bi_bdev->bd_disk->flags & GENHD_FL_FAIL) || (bio->bi_bdev->bd_part && bio->bi_bdev->bd_part->make_it_fail)) return should_fail(&fail_make_request, bio->bi_size); return 0; } static int __init fail_make_request_debugfs(void) { return init_fault_attr_dentries(&fail_make_request, "fail_make_request"); } late_initcall(fail_make_request_debugfs); #else /* CONFIG_FAIL_MAKE_REQUEST */ static inline int should_fail_request(struct bio *bio) { return 0; } #endif /* CONFIG_FAIL_MAKE_REQUEST */ |
c07e2b412 block: factor our... |
1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 |
/* * 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. */ maxsector = bio->bi_bdev->bd_inode->i_size >> 9; 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 |
1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 |
/** * generic_make_request: hand a buffer to its device driver for I/O * @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... |
1277 |
static inline void __generic_make_request(struct bio *bio) |
1da177e4c Linux-2.6.12-rc2 |
1278 |
{ |
165125e1e [BLOCK] Get rid o... |
1279 |
struct request_queue *q; |
5ddfe9691 [PATCH] md: check... |
1280 |
sector_t old_sector; |
1da177e4c Linux-2.6.12-rc2 |
1281 |
int ret, nr_sectors = bio_sectors(bio); |
2056a782f [PATCH] Block que... |
1282 |
dev_t old_dev; |
51fd77bd9 [BLOCK] Don't all... |
1283 |
int err = -EIO; |
1da177e4c Linux-2.6.12-rc2 |
1284 1285 |
might_sleep(); |
1da177e4c Linux-2.6.12-rc2 |
1286 |
|
c07e2b412 block: factor our... |
1287 1288 |
if (bio_check_eod(bio, nr_sectors)) goto end_io; |
1da177e4c Linux-2.6.12-rc2 |
1289 1290 1291 1292 1293 1294 1295 1296 1297 |
/* * 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... |
1298 |
old_sector = -1; |
2056a782f [PATCH] Block que... |
1299 |
old_dev = 0; |
1da177e4c Linux-2.6.12-rc2 |
1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 |
do { char b[BDEVNAME_SIZE]; q = bdev_get_queue(bio->bi_bdev); if (!q) { printk(KERN_ERR "generic_make_request: Trying to access " "nonexistent block-device %s (%Lu) ", bdevname(bio->bi_bdev, b), (long long) bio->bi_sector); end_io: |
51fd77bd9 [BLOCK] Don't all... |
1312 |
bio_endio(bio, err); |
1da177e4c Linux-2.6.12-rc2 |
1313 1314 |
break; } |
4fa253f33 block: ll_rw_blk.... |
1315 |
if (unlikely(nr_sectors > q->max_hw_sectors)) { |
6728cb0e6 block: make core ... |
1316 1317 |
printk(KERN_ERR "bio too big device %s (%u > %u) ", |
1da177e4c Linux-2.6.12-rc2 |
1318 1319 1320 1321 1322 |
bdevname(bio->bi_bdev, b), bio_sectors(bio), q->max_hw_sectors); goto end_io; } |
fde6ad224 [PATCH] blk: bran... |
1323 |
if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) |
1da177e4c Linux-2.6.12-rc2 |
1324 |
goto end_io; |
c17bb4951 [PATCH] fault-inj... |
1325 1326 |
if (should_fail_request(bio)) goto end_io; |
1da177e4c Linux-2.6.12-rc2 |
1327 1328 1329 1330 1331 |
/* * If this device has partitions, remap block n * of partition p to block n+start(p) of the disk. */ blk_partition_remap(bio); |
5ddfe9691 [PATCH] md: check... |
1332 |
if (old_sector != -1) |
4fa253f33 block: ll_rw_blk.... |
1333 |
blk_add_trace_remap(q, bio, old_dev, bio->bi_sector, |
5ddfe9691 [PATCH] md: check... |
1334 |
old_sector); |
2056a782f [PATCH] Block que... |
1335 1336 |
blk_add_trace_bio(q, bio, BLK_TA_QUEUE); |
5ddfe9691 [PATCH] md: check... |
1337 |
old_sector = bio->bi_sector; |
2056a782f [PATCH] Block que... |
1338 |
old_dev = bio->bi_bdev->bd_dev; |
c07e2b412 block: factor our... |
1339 1340 |
if (bio_check_eod(bio, nr_sectors)) goto end_io; |
51fd77bd9 [BLOCK] Don't all... |
1341 1342 1343 1344 |
if (bio_empty_barrier(bio) && !q->prepare_flush_fn) { err = -EOPNOTSUPP; goto end_io; } |
5ddfe9691 [PATCH] md: check... |
1345 |
|
1da177e4c Linux-2.6.12-rc2 |
1346 1347 1348 |
ret = q->make_request_fn(q, bio); } while (ret); } |
d89d87965 When stacked bloc... |
1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 |
/* * We only want one ->make_request_fn to be active at a time, * else stack usage with stacked devices could be a problem. * So use current->bio_{list,tail} to keep a list of requests * submited by a make_request_fn function. * current->bio_tail is also used as a flag to say if * 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) { if (current->bio_tail) { /* make_request is active */ *(current->bio_tail) = bio; bio->bi_next = NULL; current->bio_tail = &bio->bi_next; 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 * we assign bio_list to the next (which is NULL) and bio_tail * to &bio_list, thus initialising the bio_list of new bios to be * 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 * of the top of the list (no pretending) and so fixup bio_list and * bio_tail or bi_next, and call into __generic_make_request again. * * 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); do { current->bio_list = bio->bi_next; if (bio->bi_next == NULL) current->bio_tail = ¤t->bio_list; else bio->bi_next = NULL; __generic_make_request(bio); bio = current->bio_list; } while (bio); current->bio_tail = NULL; /* deactivate */ } |
1da177e4c Linux-2.6.12-rc2 |
1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 |
EXPORT_SYMBOL(generic_make_request); /** * submit_bio: submit a bio to the block device layer for I/O * @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 * interfaces, @bio must be presetup and ready for I/O. * */ void submit_bio(int rw, struct bio *bio) { int count = bio_sectors(bio); |
22e2c507c [PATCH] Update cf... |
1414 |
bio->bi_rw |= rw; |
1da177e4c Linux-2.6.12-rc2 |
1415 |
|
bf2de6f5a block: Initial su... |
1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 |
/* * If it's a regular read/write or a barrier with data attached, * go through the normal accounting stuff before submission. */ if (!bio_empty_barrier(bio)) { BIO_BUG_ON(!bio->bi_size); BIO_BUG_ON(!bio->bi_io_vec); 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]; printk(KERN_DEBUG "%s(%d): %s block %Lu on %s ", |
ba25f9dcc Use helpers to ob... |
1436 |
current->comm, task_pid_nr(current), |
bf2de6f5a block: Initial su... |
1437 1438 |
(rw & WRITE) ? "WRITE" : "READ", (unsigned long long)bio->bi_sector, |
6728cb0e6 block: make core ... |
1439 |
bdevname(bio->bi_bdev, b)); |
bf2de6f5a block: Initial su... |
1440 |
} |
1da177e4c Linux-2.6.12-rc2 |
1441 1442 1443 1444 |
} generic_make_request(bio); } |
1da177e4c Linux-2.6.12-rc2 |
1445 |
EXPORT_SYMBOL(submit_bio); |
3bcddeac1 blk_end_request: ... |
1446 1447 1448 |
/** * __end_that_request_first - end I/O on a request * @req: the request being processed |
5450d3e1d blk_end_request: ... |
1449 |
* @error: 0 for success, < 0 for error |
3bcddeac1 blk_end_request: ... |
1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 |
* @nr_bytes: number of bytes to complete * * Description: * Ends I/O on a number of bytes attached to @req, and sets it up * for the next range of segments (if any) in the cluster. * * Return: * 0 - we are done with this request, call end_that_request_last() * 1 - still buffers pending for this request **/ |
5450d3e1d blk_end_request: ... |
1460 |
static int __end_that_request_first(struct request *req, int error, |
1da177e4c Linux-2.6.12-rc2 |
1461 1462 |
int nr_bytes) { |
5450d3e1d blk_end_request: ... |
1463 |
int total_bytes, bio_nbytes, next_idx = 0; |
1da177e4c Linux-2.6.12-rc2 |
1464 |
struct bio *bio; |
2056a782f [PATCH] Block que... |
1465 |
blk_add_trace_rq(req->q, req, BLK_TA_COMPLETE); |
1da177e4c Linux-2.6.12-rc2 |
1466 |
/* |
1da177e4c Linux-2.6.12-rc2 |
1467 1468 1469 1470 1471 |
* for a REQ_BLOCK_PC request, we want to carry any eventual * sense key with us all the way through */ if (!blk_pc_request(req)) req->errors = 0; |
6728cb0e6 block: make core ... |
1472 1473 1474 |
if (error && (blk_fs_request(req) && !(req->cmd_flags & REQ_QUIET))) { printk(KERN_ERR "end_request: I/O error, dev %s, sector %llu ", |
1da177e4c Linux-2.6.12-rc2 |
1475 1476 1477 |
req->rq_disk ? req->rq_disk->disk_name : "?", (unsigned long long)req->sector); } |
d72d904a5 [BLOCK] Update re... |
1478 |
if (blk_fs_request(req) && req->rq_disk) { |
a362357b6 [BLOCK] Unify the... |
1479 |
const int rw = rq_data_dir(req); |
6f2576af5 Enhanced partitio... |
1480 1481 |
all_stat_add(req->rq_disk, sectors[rw], nr_bytes >> 9, req->sector); |
d72d904a5 [BLOCK] Update re... |
1482 |
} |
1da177e4c Linux-2.6.12-rc2 |
1483 1484 1485 |
total_bytes = bio_nbytes = 0; while ((bio = req->bio) != NULL) { int nbytes; |
bf2de6f5a block: Initial su... |
1486 1487 1488 1489 1490 1491 1492 |
/* * For an empty barrier request, the low level driver must * store a potential error location in ->sector. We pass * that back up in ->bi_sector. */ if (blk_empty_barrier(req)) bio->bi_sector = req->sector; |
1da177e4c Linux-2.6.12-rc2 |
1493 1494 1495 |
if (nr_bytes >= bio->bi_size) { req->bio = bio->bi_next; nbytes = bio->bi_size; |
5bb23a688 Don't decrement b... |
1496 |
req_bio_endio(req, bio, nbytes, error); |
1da177e4c Linux-2.6.12-rc2 |
1497 1498 1499 1500 1501 1502 1503 |
next_idx = 0; bio_nbytes = 0; } else { int idx = bio->bi_idx + next_idx; if (unlikely(bio->bi_idx >= bio->bi_vcnt)) { blk_dump_rq_flags(req, "__end_that"); |
6728cb0e6 block: make core ... |
1504 1505 1506 1507 |
printk(KERN_ERR "%s: bio idx %d >= vcnt %d ", __FUNCTION__, bio->bi_idx, bio->bi_vcnt); |
1da177e4c Linux-2.6.12-rc2 |
1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 |
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 ... |
1532 1533 |
bio = req->bio; if (bio) { |
1da177e4c Linux-2.6.12-rc2 |
1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 |
/* * end more in this run, or just return 'not-done' */ if (unlikely(nr_bytes <= 0)) break; } } /* * completely done */ if (!req->bio) return 0; /* * if the request wasn't completed, update state */ if (bio_nbytes) { |
5bb23a688 Don't decrement b... |
1552 |
req_bio_endio(req, bio, bio_nbytes, error); |
1da177e4c Linux-2.6.12-rc2 |
1553 1554 1555 1556 1557 1558 1559 1560 1561 |
bio->bi_idx += next_idx; bio_iovec(bio)->bv_offset += nr_bytes; bio_iovec(bio)->bv_len -= nr_bytes; } blk_recalc_rq_sectors(req, total_bytes >> 9); blk_recalc_rq_segments(req); return 1; } |
1da177e4c Linux-2.6.12-rc2 |
1562 |
/* |
ff856bad6 [BLOCK] ll_rw_blk... |
1563 1564 1565 1566 1567 |
* splice the completion data to a local structure and hand off to * process_completion_queue() to complete the requests */ static void blk_done_softirq(struct softirq_action *h) { |
626ab0e69 [PATCH] list: use... |
1568 |
struct list_head *cpu_list, local_list; |
ff856bad6 [BLOCK] ll_rw_blk... |
1569 1570 1571 |
local_irq_disable(); cpu_list = &__get_cpu_var(blk_cpu_done); |
626ab0e69 [PATCH] list: use... |
1572 |
list_replace_init(cpu_list, &local_list); |
ff856bad6 [BLOCK] ll_rw_blk... |
1573 1574 1575 |
local_irq_enable(); while (!list_empty(&local_list)) { |
6728cb0e6 block: make core ... |
1576 |
struct request *rq; |
ff856bad6 [BLOCK] ll_rw_blk... |
1577 |
|
6728cb0e6 block: make core ... |
1578 |
rq = list_entry(local_list.next, struct request, donelist); |
ff856bad6 [BLOCK] ll_rw_blk... |
1579 1580 1581 1582 |
list_del_init(&rq->donelist); rq->q->softirq_done_fn(rq); } } |
6728cb0e6 block: make core ... |
1583 1584 |
static int __cpuinit blk_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) |
ff856bad6 [BLOCK] ll_rw_blk... |
1585 1586 1587 1588 1589 |
{ /* * If a CPU goes away, splice its entries to the current CPU * and trigger a run of the softirq */ |
8bb784428 Add suspend-relat... |
1590 |
if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { |
ff856bad6 [BLOCK] ll_rw_blk... |
1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 |
int cpu = (unsigned long) hcpu; local_irq_disable(); list_splice_init(&per_cpu(blk_cpu_done, cpu), &__get_cpu_var(blk_cpu_done)); raise_softirq_irqoff(BLOCK_SOFTIRQ); local_irq_enable(); } return NOTIFY_OK; } |
db47d4753 ll_rw_blk: blk_cp... |
1602 |
static struct notifier_block blk_cpu_notifier __cpuinitdata = { |
ff856bad6 [BLOCK] ll_rw_blk... |
1603 1604 |
.notifier_call = blk_cpu_notify, }; |
ff856bad6 [BLOCK] ll_rw_blk... |
1605 1606 1607 1608 1609 1610 |
/** * blk_complete_request - end I/O on a request * @req: the request being processed * * Description: * Ends all I/O on a request. It does not handle partial completions, |
d6e05edc5 spelling fixes |
1611 |
* unless the driver actually implements this in its completion callback |
4fa253f33 block: ll_rw_blk.... |
1612 |
* through requeueing. The actual completion happens out-of-order, |
ff856bad6 [BLOCK] ll_rw_blk... |
1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 |
* through a softirq handler. The user must have registered a completion * callback through blk_queue_softirq_done(). **/ void blk_complete_request(struct request *req) { struct list_head *cpu_list; unsigned long flags; BUG_ON(!req->q->softirq_done_fn); |
6728cb0e6 block: make core ... |
1623 |
|
ff856bad6 [BLOCK] ll_rw_blk... |
1624 1625 1626 1627 1628 1629 1630 1631 |
local_irq_save(flags); cpu_list = &__get_cpu_var(blk_cpu_done); list_add_tail(&req->donelist, cpu_list); raise_softirq_irqoff(BLOCK_SOFTIRQ); local_irq_restore(flags); } |
ff856bad6 [BLOCK] ll_rw_blk... |
1632 |
EXPORT_SYMBOL(blk_complete_request); |
6728cb0e6 block: make core ... |
1633 |
|
ff856bad6 [BLOCK] ll_rw_blk... |
1634 |
/* |
1da177e4c Linux-2.6.12-rc2 |
1635 1636 |
* queue lock must be held */ |
5450d3e1d blk_end_request: ... |
1637 |
static void end_that_request_last(struct request *req, int error) |
1da177e4c Linux-2.6.12-rc2 |
1638 1639 |
{ struct gendisk *disk = req->rq_disk; |
8ffdc6550 [BLOCK] add @upto... |
1640 |
|
b8286239d blk_end_request: ... |
1641 1642 1643 1644 1645 |
if (blk_rq_tagged(req)) blk_queue_end_tag(req->q, req); if (blk_queued_rq(req)) blkdev_dequeue_request(req); |
1da177e4c Linux-2.6.12-rc2 |
1646 1647 1648 |
if (unlikely(laptop_mode) && blk_fs_request(req)) laptop_io_completion(); |
fd0ff8aa1 [PATCH] blk: fix ... |
1649 1650 1651 1652 1653 1654 |
/* * Account IO completion. bar_rq isn't accounted as a normal * IO on queueing nor completion. Accounting the containing * request is enough. */ if (disk && blk_fs_request(req) && req != &req->q->bar_rq) { |
1da177e4c Linux-2.6.12-rc2 |
1655 |
unsigned long duration = jiffies - req->start_time; |
a362357b6 [BLOCK] Unify the... |
1656 |
const int rw = rq_data_dir(req); |
6f2576af5 Enhanced partitio... |
1657 |
struct hd_struct *part = get_part(disk, req->sector); |
a362357b6 [BLOCK] Unify the... |
1658 |
|
6f2576af5 Enhanced partitio... |
1659 1660 |
__all_stat_inc(disk, ios[rw], req->sector); __all_stat_add(disk, ticks[rw], duration, req->sector); |
1da177e4c Linux-2.6.12-rc2 |
1661 1662 |
disk_round_stats(disk); disk->in_flight--; |
6f2576af5 Enhanced partitio... |
1663 1664 1665 1666 |
if (part) { part_round_stats(part); part->in_flight--; } |
1da177e4c Linux-2.6.12-rc2 |
1667 |
} |
b8286239d blk_end_request: ... |
1668 |
|
1da177e4c Linux-2.6.12-rc2 |
1669 |
if (req->end_io) |
8ffdc6550 [BLOCK] add @upto... |
1670 |
req->end_io(req, error); |
b8286239d blk_end_request: ... |
1671 1672 1673 |
else { if (blk_bidi_rq(req)) __blk_put_request(req->next_rq->q, req->next_rq); |
1da177e4c Linux-2.6.12-rc2 |
1674 |
__blk_put_request(req->q, req); |
b8286239d blk_end_request: ... |
1675 |
} |
1da177e4c Linux-2.6.12-rc2 |
1676 |
} |
a0cd12854 block: add end_qu... |
1677 |
static inline void __end_request(struct request *rq, int uptodate, |
9e6e39f2c blk_end_request: ... |
1678 |
unsigned int nr_bytes) |
1da177e4c Linux-2.6.12-rc2 |
1679 |
{ |
9e6e39f2c blk_end_request: ... |
1680 1681 1682 1683 1684 1685 |
int error = 0; if (uptodate <= 0) error = uptodate ? uptodate : -EIO; __blk_end_request(rq, error, nr_bytes); |
1da177e4c Linux-2.6.12-rc2 |
1686 |
} |
3b11313a6 blk_end_request: ... |
1687 1688 |
/** * blk_rq_bytes - Returns bytes left to complete in the entire request |
5d87a052c block: fix kernel... |
1689 |
* @rq: the request being processed |
3b11313a6 blk_end_request: ... |
1690 1691 |
**/ unsigned int blk_rq_bytes(struct request *rq) |
a0cd12854 block: add end_qu... |
1692 1693 1694 1695 1696 1697 |
{ if (blk_fs_request(rq)) return rq->hard_nr_sectors << 9; return rq->data_len; } |
3b11313a6 blk_end_request: ... |
1698 1699 1700 1701 |
EXPORT_SYMBOL_GPL(blk_rq_bytes); /** * blk_rq_cur_bytes - Returns bytes left to complete in the current segment |
5d87a052c block: fix kernel... |
1702 |
* @rq: the request being processed |
3b11313a6 blk_end_request: ... |
1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 |
**/ unsigned int blk_rq_cur_bytes(struct request *rq) { if (blk_fs_request(rq)) return rq->current_nr_sectors << 9; if (rq->bio) return rq->bio->bi_size; return rq->data_len; } EXPORT_SYMBOL_GPL(blk_rq_cur_bytes); |
a0cd12854 block: add end_qu... |
1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 |
/** * end_queued_request - end all I/O on a queued request * @rq: the request being processed * @uptodate: error value or 0/1 uptodate flag * * Description: * Ends all I/O on a request, and removes it from the block layer queues. * Not suitable for normal IO completion, unless the driver still has * the request attached to the block layer. * **/ void end_queued_request(struct request *rq, int uptodate) { |
9e6e39f2c blk_end_request: ... |
1729 |
__end_request(rq, uptodate, blk_rq_bytes(rq)); |
a0cd12854 block: add end_qu... |
1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 |
} EXPORT_SYMBOL(end_queued_request); /** * end_dequeued_request - end all I/O on a dequeued request * @rq: the request being processed * @uptodate: error value or 0/1 uptodate flag * * Description: * Ends all I/O on a request. The request must already have been * dequeued using blkdev_dequeue_request(), as is normally the case * for most drivers. * **/ void end_dequeued_request(struct request *rq, int uptodate) { |
9e6e39f2c blk_end_request: ... |
1746 |
__end_request(rq, uptodate, blk_rq_bytes(rq)); |
a0cd12854 block: add end_qu... |
1747 1748 1749 1750 1751 1752 |
} EXPORT_SYMBOL(end_dequeued_request); /** * end_request - end I/O on the current segment of the request |
8f731f7d8 kernel-api docboo... |
1753 |
* @req: the request being processed |
a0cd12854 block: add end_qu... |
1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 |
* @uptodate: error value or 0/1 uptodate flag * * Description: * Ends I/O on the current segment of a request. If that is the only * remaining segment, the request is also completed and freed. * * This is a remnant of how older block drivers handled IO completions. * Modern drivers typically end IO on the full request in one go, unless * they have a residual value to account for. For that case this function * isn't really useful, unless the residual just happens to be the * full current segment. In other words, don't use this function in new * code. Either use end_request_completely(), or the * end_that_request_chunk() (along with end_that_request_last()) for * partial completions. * **/ void end_request(struct request *req, int uptodate) { |
9e6e39f2c blk_end_request: ... |
1772 |
__end_request(req, uptodate, req->hard_cur_sectors << 9); |
a0cd12854 block: add end_qu... |
1773 |
} |
1da177e4c Linux-2.6.12-rc2 |
1774 |
EXPORT_SYMBOL(end_request); |
336cdb400 blk_end_request: ... |
1775 |
/** |
e19a3ab05 blk_end_request: ... |
1776 1777 1778 |
* blk_end_io - Generic end_io function to complete a request. * @rq: the request being processed * @error: 0 for success, < 0 for error |
e3a04fe34 blk_end_request: ... |
1779 1780 |
* @nr_bytes: number of bytes to complete @rq * @bidi_bytes: number of bytes to complete @rq->next_rq |
e19a3ab05 blk_end_request: ... |
1781 1782 1783 1784 |
* @drv_callback: function called between completion of bios in the request * and completion of the request. * If the callback returns non 0, this helper returns without * completion of the request. |
336cdb400 blk_end_request: ... |
1785 1786 |
* * Description: |
e3a04fe34 blk_end_request: ... |
1787 |
* Ends I/O on a number of bytes attached to @rq and @rq->next_rq. |
336cdb400 blk_end_request: ... |
1788 1789 1790 1791 |
* If @rq has leftover, sets it up for the next range of segments. * * Return: * 0 - we are done with this request |
e19a3ab05 blk_end_request: ... |
1792 |
* 1 - this request is not freed yet, it still has pending buffers. |
336cdb400 blk_end_request: ... |
1793 |
**/ |
22b132102 block: new end re... |
1794 1795 1796 |
static int blk_end_io(struct request *rq, int error, unsigned int nr_bytes, unsigned int bidi_bytes, int (drv_callback)(struct request *)) |
336cdb400 blk_end_request: ... |
1797 1798 1799 |
{ struct request_queue *q = rq->q; unsigned long flags = 0UL; |
336cdb400 blk_end_request: ... |
1800 1801 |
if (blk_fs_request(rq) || blk_pc_request(rq)) { |
5450d3e1d blk_end_request: ... |
1802 |
if (__end_that_request_first(rq, error, nr_bytes)) |
336cdb400 blk_end_request: ... |
1803 |
return 1; |
e3a04fe34 blk_end_request: ... |
1804 1805 1806 |
/* Bidi request must be completed as a whole */ if (blk_bidi_rq(rq) && |
5450d3e1d blk_end_request: ... |
1807 |
__end_that_request_first(rq->next_rq, error, bidi_bytes)) |
e3a04fe34 blk_end_request: ... |
1808 |
return 1; |
336cdb400 blk_end_request: ... |
1809 |
} |
e19a3ab05 blk_end_request: ... |
1810 1811 1812 |
/* Special feature for tricky drivers */ if (drv_callback && drv_callback(rq)) return 1; |
336cdb400 blk_end_request: ... |
1813 1814 1815 |
add_disk_randomness(rq->rq_disk); spin_lock_irqsave(q->queue_lock, flags); |
b8286239d blk_end_request: ... |
1816 |
end_that_request_last(rq, error); |
336cdb400 blk_end_request: ... |
1817 1818 1819 1820 |
spin_unlock_irqrestore(q->queue_lock, flags); return 0; } |
e19a3ab05 blk_end_request: ... |
1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 |
/** * 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 * * 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: * 0 - we are done with this request * 1 - still buffers pending for this request **/ |
22b132102 block: new end re... |
1836 |
int blk_end_request(struct request *rq, int error, unsigned int nr_bytes) |
e19a3ab05 blk_end_request: ... |
1837 |
{ |
e3a04fe34 blk_end_request: ... |
1838 |
return blk_end_io(rq, error, nr_bytes, 0, NULL); |
e19a3ab05 blk_end_request: ... |
1839 |
} |
336cdb400 blk_end_request: ... |
1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 |
EXPORT_SYMBOL_GPL(blk_end_request); /** * __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 * * Description: * Must be called with queue lock held unlike blk_end_request(). * * Return: * 0 - we are done with this request * 1 - still buffers pending for this request **/ |
22b132102 block: new end re... |
1855 |
int __blk_end_request(struct request *rq, int error, unsigned int nr_bytes) |
336cdb400 blk_end_request: ... |
1856 |
{ |
336cdb400 blk_end_request: ... |
1857 |
if (blk_fs_request(rq) || blk_pc_request(rq)) { |
5450d3e1d blk_end_request: ... |
1858 |
if (__end_that_request_first(rq, error, nr_bytes)) |
336cdb400 blk_end_request: ... |
1859 1860 1861 1862 |
return 1; } add_disk_randomness(rq->rq_disk); |
b8286239d blk_end_request: ... |
1863 |
end_that_request_last(rq, error); |
336cdb400 blk_end_request: ... |
1864 1865 1866 1867 |
return 0; } EXPORT_SYMBOL_GPL(__blk_end_request); |
e19a3ab05 blk_end_request: ... |
1868 |
/** |
e3a04fe34 blk_end_request: ... |
1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 |
* blk_end_bidi_request - Helper function for drivers to complete bidi request. * @rq: the bidi request being processed * @error: 0 for success, < 0 for error * @nr_bytes: number of bytes to complete @rq * @bidi_bytes: number of bytes to complete @rq->next_rq * * Description: * Ends I/O on a number of bytes attached to @rq and @rq->next_rq. * * Return: * 0 - we are done with this request * 1 - still buffers pending for this request **/ |
22b132102 block: new end re... |
1882 1883 |
int blk_end_bidi_request(struct request *rq, int error, unsigned int nr_bytes, unsigned int bidi_bytes) |
e3a04fe34 blk_end_request: ... |
1884 1885 1886 1887 1888 1889 |
{ return blk_end_io(rq, error, nr_bytes, bidi_bytes, NULL); } EXPORT_SYMBOL_GPL(blk_end_bidi_request); /** |
e19a3ab05 blk_end_request: ... |
1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 |
* blk_end_request_callback - Special helper function for tricky drivers * @rq: the request being processed * @error: 0 for success, < 0 for error * @nr_bytes: number of bytes to complete * @drv_callback: function called between completion of bios in the request * and completion of the request. * If the callback returns non 0, this helper returns without * completion of the request. * * 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. * * This special helper function is used only for existing tricky drivers. * (e.g. cdrom_newpc_intr() of ide-cd) * This interface will be removed when such drivers are rewritten. * Don't use this interface in other places anymore. * * Return: * 0 - we are done with this request * 1 - this request is not freed yet. * this request still has pending buffers or * the driver doesn't want to finish this request yet. **/ |
22b132102 block: new end re... |
1914 1915 |
int blk_end_request_callback(struct request *rq, int error, unsigned int nr_bytes, |
e19a3ab05 blk_end_request: ... |
1916 1917 |
int (drv_callback)(struct request *)) { |
e3a04fe34 blk_end_request: ... |
1918 |
return blk_end_io(rq, error, nr_bytes, 0, drv_callback); |
e19a3ab05 blk_end_request: ... |
1919 1920 |
} EXPORT_SYMBOL_GPL(blk_end_request_callback); |
86db1e297 block: continue l... |
1921 1922 |
void blk_rq_bio_prep(struct request_queue *q, struct request *rq, struct bio *bio) |
1da177e4c Linux-2.6.12-rc2 |
1923 |
{ |
4aff5e233 [PATCH] Split str... |
1924 1925 |
/* first two bits are identical in rq->cmd_flags and bio->bi_rw */ rq->cmd_flags |= (bio->bi_rw & 3); |
1da177e4c Linux-2.6.12-rc2 |
1926 1927 1928 1929 1930 1931 1932 |
rq->nr_phys_segments = bio_phys_segments(q, bio); rq->nr_hw_segments = bio_hw_segments(q, bio); rq->current_nr_sectors = bio_cur_sectors(bio); rq->hard_cur_sectors = rq->current_nr_sectors; rq->hard_nr_sectors = rq->nr_sectors = bio_sectors(bio); rq->buffer = bio_data(bio); |
0e75f9063 [PATCH] block: su... |
1933 |
rq->data_len = bio->bi_size; |
1da177e4c Linux-2.6.12-rc2 |
1934 1935 |
rq->bio = rq->biotail = bio; |
1da177e4c Linux-2.6.12-rc2 |
1936 |
|
66846572b Stop exporting bl... |
1937 1938 1939 |
if (bio->bi_bdev) rq->rq_disk = bio->bi_bdev->bd_disk; } |
1da177e4c Linux-2.6.12-rc2 |
1940 1941 1942 1943 1944 |
int kblockd_schedule_work(struct work_struct *work) { return queue_work(kblockd_workqueue, work); } |
1da177e4c Linux-2.6.12-rc2 |
1945 |
EXPORT_SYMBOL(kblockd_schedule_work); |
19a75d83f kblockd: use flus... |
1946 |
void kblockd_flush_work(struct work_struct *work) |
1da177e4c Linux-2.6.12-rc2 |
1947 |
{ |
28e53bddf unify flush_work/... |
1948 |
cancel_work_sync(work); |
1da177e4c Linux-2.6.12-rc2 |
1949 |
} |
19a75d83f kblockd: use flus... |
1950 |
EXPORT_SYMBOL(kblockd_flush_work); |
1da177e4c Linux-2.6.12-rc2 |
1951 1952 1953 |
int __init blk_dev_init(void) { |
ff856bad6 [BLOCK] ll_rw_blk... |
1954 |
int i; |
1da177e4c Linux-2.6.12-rc2 |
1955 1956 1957 1958 1959 1960 |
kblockd_workqueue = create_workqueue("kblockd"); if (!kblockd_workqueue) panic("Failed to create kblockd "); request_cachep = kmem_cache_create("blkdev_requests", |
20c2df83d mm: Remove slab d... |
1961 |
sizeof(struct request), 0, SLAB_PANIC, NULL); |
1da177e4c Linux-2.6.12-rc2 |
1962 |
|
8324aa91d block: split tag ... |
1963 |
blk_requestq_cachep = kmem_cache_create("blkdev_queue", |
165125e1e [BLOCK] Get rid o... |
1964 |
sizeof(struct request_queue), 0, SLAB_PANIC, NULL); |
1da177e4c Linux-2.6.12-rc2 |
1965 |
|
0a9450227 [PATCH] for_each_... |
1966 |
for_each_possible_cpu(i) |
ff856bad6 [BLOCK] ll_rw_blk... |
1967 1968 1969 |
INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i)); open_softirq(BLOCK_SOFTIRQ, blk_done_softirq, NULL); |
5a67e4c5b [PATCH] cpu hotpl... |
1970 |
register_hotcpu_notifier(&blk_cpu_notifier); |
ff856bad6 [BLOCK] ll_rw_blk... |
1971 |
|
d38ecf935 io context sharin... |
1972 |
return 0; |
1da177e4c Linux-2.6.12-rc2 |
1973 |
} |
1da177e4c Linux-2.6.12-rc2 |
1974 |