block: split tag and sysfs handling from blk-core.c
Seperates the tag and sysfs handling from ll_rw_blk. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>hifive-unleashed-5.1
Jens Axboe
parent
a168ee84c9
commit
8324aa91d1
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@ -2,7 +2,8 @@
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# Makefile for the kernel block layer
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#
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obj-$(CONFIG_BLOCK) := elevator.o blk-core.o ioctl.o genhd.o scsi_ioctl.o
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obj-$(CONFIG_BLOCK) := elevator.o blk-core.o blk-tag.o blk-sysfs.o ioctl.o \
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genhd.o scsi_ioctl.o
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obj-$(CONFIG_BLK_DEV_BSG) += bsg.o
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obj-$(CONFIG_IOSCHED_NOOP) += noop-iosched.o
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719
block/blk-core.c
719
block/blk-core.c
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@ -32,6 +32,8 @@
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#include <linux/fault-inject.h>
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#include <linux/scatterlist.h>
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#include "blk.h"
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/*
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* for max sense size
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*/
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@ -50,12 +52,12 @@ static void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
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/*
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* For the allocated request tables
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*/
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static struct kmem_cache *request_cachep;
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struct kmem_cache *request_cachep;
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/*
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* For queue allocation
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*/
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static struct kmem_cache *requestq_cachep;
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struct kmem_cache *blk_requestq_cachep = NULL;
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/*
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* For io context allocations
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@ -80,25 +82,7 @@ static DEFINE_PER_CPU(struct list_head, blk_cpu_done);
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/* Number of requests a "batching" process may submit */
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#define BLK_BATCH_REQ 32
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/*
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* Return the threshold (number of used requests) at which the queue is
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* considered to be congested. It include a little hysteresis to keep the
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* context switch rate down.
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*/
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static inline int queue_congestion_on_threshold(struct request_queue *q)
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{
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return q->nr_congestion_on;
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}
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/*
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* The threshold at which a queue is considered to be uncongested
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*/
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static inline int queue_congestion_off_threshold(struct request_queue *q)
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{
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return q->nr_congestion_off;
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}
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static void blk_queue_congestion_threshold(struct request_queue *q)
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void blk_queue_congestion_threshold(struct request_queue *q)
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{
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int nr;
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@ -817,397 +801,6 @@ void blk_queue_update_dma_alignment(struct request_queue *q, int mask)
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EXPORT_SYMBOL(blk_queue_update_dma_alignment);
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/**
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* blk_queue_find_tag - find a request by its tag and queue
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* @q: The request queue for the device
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* @tag: The tag of the request
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*
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* Notes:
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* Should be used when a device returns a tag and you want to match
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* it with a request.
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*
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* no locks need be held.
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**/
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struct request *blk_queue_find_tag(struct request_queue *q, int tag)
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{
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return blk_map_queue_find_tag(q->queue_tags, tag);
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}
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EXPORT_SYMBOL(blk_queue_find_tag);
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/**
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* __blk_free_tags - release a given set of tag maintenance info
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* @bqt: the tag map to free
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*
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* Tries to free the specified @bqt@. Returns true if it was
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* actually freed and false if there are still references using it
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*/
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static int __blk_free_tags(struct blk_queue_tag *bqt)
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{
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int retval;
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retval = atomic_dec_and_test(&bqt->refcnt);
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if (retval) {
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BUG_ON(bqt->busy);
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kfree(bqt->tag_index);
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bqt->tag_index = NULL;
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kfree(bqt->tag_map);
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bqt->tag_map = NULL;
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kfree(bqt);
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}
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return retval;
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}
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/**
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* __blk_queue_free_tags - release tag maintenance info
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* @q: the request queue for the device
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*
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* Notes:
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* blk_cleanup_queue() will take care of calling this function, if tagging
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* has been used. So there's no need to call this directly.
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**/
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static void __blk_queue_free_tags(struct request_queue *q)
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{
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struct blk_queue_tag *bqt = q->queue_tags;
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if (!bqt)
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return;
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__blk_free_tags(bqt);
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q->queue_tags = NULL;
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q->queue_flags &= ~(1 << QUEUE_FLAG_QUEUED);
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}
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/**
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* blk_free_tags - release a given set of tag maintenance info
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* @bqt: the tag map to free
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*
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* For externally managed @bqt@ frees the map. Callers of this
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* function must guarantee to have released all the queues that
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* might have been using this tag map.
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*/
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void blk_free_tags(struct blk_queue_tag *bqt)
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{
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if (unlikely(!__blk_free_tags(bqt)))
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BUG();
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}
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EXPORT_SYMBOL(blk_free_tags);
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/**
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* blk_queue_free_tags - release tag maintenance info
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* @q: the request queue for the device
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*
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* Notes:
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* This is used to disabled tagged queuing to a device, yet leave
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* queue in function.
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**/
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void blk_queue_free_tags(struct request_queue *q)
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{
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clear_bit(QUEUE_FLAG_QUEUED, &q->queue_flags);
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}
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EXPORT_SYMBOL(blk_queue_free_tags);
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static int
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init_tag_map(struct request_queue *q, struct blk_queue_tag *tags, int depth)
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{
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struct request **tag_index;
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unsigned long *tag_map;
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int nr_ulongs;
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if (q && depth > q->nr_requests * 2) {
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depth = q->nr_requests * 2;
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printk(KERN_ERR "%s: adjusted depth to %d\n",
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__FUNCTION__, depth);
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}
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tag_index = kzalloc(depth * sizeof(struct request *), GFP_ATOMIC);
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if (!tag_index)
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goto fail;
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nr_ulongs = ALIGN(depth, BITS_PER_LONG) / BITS_PER_LONG;
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tag_map = kzalloc(nr_ulongs * sizeof(unsigned long), GFP_ATOMIC);
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if (!tag_map)
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goto fail;
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tags->real_max_depth = depth;
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tags->max_depth = depth;
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tags->tag_index = tag_index;
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tags->tag_map = tag_map;
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return 0;
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fail:
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kfree(tag_index);
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return -ENOMEM;
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}
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static struct blk_queue_tag *__blk_queue_init_tags(struct request_queue *q,
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int depth)
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{
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struct blk_queue_tag *tags;
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tags = kmalloc(sizeof(struct blk_queue_tag), GFP_ATOMIC);
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if (!tags)
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goto fail;
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if (init_tag_map(q, tags, depth))
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goto fail;
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tags->busy = 0;
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atomic_set(&tags->refcnt, 1);
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return tags;
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fail:
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kfree(tags);
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return NULL;
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}
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/**
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* blk_init_tags - initialize the tag info for an external tag map
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* @depth: the maximum queue depth supported
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* @tags: the tag to use
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**/
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struct blk_queue_tag *blk_init_tags(int depth)
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{
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return __blk_queue_init_tags(NULL, depth);
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}
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EXPORT_SYMBOL(blk_init_tags);
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/**
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* blk_queue_init_tags - initialize the queue tag info
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* @q: the request queue for the device
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* @depth: the maximum queue depth supported
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* @tags: the tag to use
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**/
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int blk_queue_init_tags(struct request_queue *q, int depth,
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struct blk_queue_tag *tags)
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{
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int rc;
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BUG_ON(tags && q->queue_tags && tags != q->queue_tags);
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if (!tags && !q->queue_tags) {
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tags = __blk_queue_init_tags(q, depth);
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if (!tags)
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goto fail;
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} else if (q->queue_tags) {
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if ((rc = blk_queue_resize_tags(q, depth)))
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return rc;
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set_bit(QUEUE_FLAG_QUEUED, &q->queue_flags);
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return 0;
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} else
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atomic_inc(&tags->refcnt);
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/*
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* assign it, all done
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*/
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q->queue_tags = tags;
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q->queue_flags |= (1 << QUEUE_FLAG_QUEUED);
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INIT_LIST_HEAD(&q->tag_busy_list);
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return 0;
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fail:
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kfree(tags);
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return -ENOMEM;
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}
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EXPORT_SYMBOL(blk_queue_init_tags);
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/**
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* blk_queue_resize_tags - change the queueing depth
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* @q: the request queue for the device
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* @new_depth: the new max command queueing depth
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*
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* Notes:
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* Must be called with the queue lock held.
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**/
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int blk_queue_resize_tags(struct request_queue *q, int new_depth)
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{
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struct blk_queue_tag *bqt = q->queue_tags;
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struct request **tag_index;
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unsigned long *tag_map;
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int max_depth, nr_ulongs;
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if (!bqt)
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return -ENXIO;
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/*
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* if we already have large enough real_max_depth. just
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* adjust max_depth. *NOTE* as requests with tag value
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* between new_depth and real_max_depth can be in-flight, tag
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* map can not be shrunk blindly here.
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*/
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if (new_depth <= bqt->real_max_depth) {
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bqt->max_depth = new_depth;
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return 0;
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}
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/*
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* Currently cannot replace a shared tag map with a new
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* one, so error out if this is the case
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*/
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if (atomic_read(&bqt->refcnt) != 1)
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return -EBUSY;
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/*
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* save the old state info, so we can copy it back
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*/
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tag_index = bqt->tag_index;
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tag_map = bqt->tag_map;
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max_depth = bqt->real_max_depth;
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if (init_tag_map(q, bqt, new_depth))
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return -ENOMEM;
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memcpy(bqt->tag_index, tag_index, max_depth * sizeof(struct request *));
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nr_ulongs = ALIGN(max_depth, BITS_PER_LONG) / BITS_PER_LONG;
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memcpy(bqt->tag_map, tag_map, nr_ulongs * sizeof(unsigned long));
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kfree(tag_index);
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kfree(tag_map);
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return 0;
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}
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EXPORT_SYMBOL(blk_queue_resize_tags);
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/**
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* blk_queue_end_tag - end tag operations for a request
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* @q: the request queue for the device
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* @rq: the request that has completed
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*
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* Description:
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* Typically called when end_that_request_first() returns 0, meaning
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* all transfers have been done for a request. It's important to call
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* this function before end_that_request_last(), as that will put the
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* request back on the free list thus corrupting the internal tag list.
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*
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* Notes:
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* queue lock must be held.
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**/
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void blk_queue_end_tag(struct request_queue *q, struct request *rq)
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{
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struct blk_queue_tag *bqt = q->queue_tags;
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int tag = rq->tag;
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BUG_ON(tag == -1);
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if (unlikely(tag >= bqt->real_max_depth))
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/*
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* This can happen after tag depth has been reduced.
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* FIXME: how about a warning or info message here?
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*/
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return;
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list_del_init(&rq->queuelist);
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rq->cmd_flags &= ~REQ_QUEUED;
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rq->tag = -1;
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if (unlikely(bqt->tag_index[tag] == NULL))
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printk(KERN_ERR "%s: tag %d is missing\n",
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__FUNCTION__, tag);
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bqt->tag_index[tag] = NULL;
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if (unlikely(!test_bit(tag, bqt->tag_map))) {
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printk(KERN_ERR "%s: attempt to clear non-busy tag (%d)\n",
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__FUNCTION__, tag);
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return;
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}
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/*
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* The tag_map bit acts as a lock for tag_index[bit], so we need
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* unlock memory barrier semantics.
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*/
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clear_bit_unlock(tag, bqt->tag_map);
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bqt->busy--;
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}
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EXPORT_SYMBOL(blk_queue_end_tag);
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/**
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* blk_queue_start_tag - find a free tag and assign it
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* @q: the request queue for the device
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* @rq: the block request that needs tagging
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*
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* Description:
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* This can either be used as a stand-alone helper, or possibly be
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* assigned as the queue &prep_rq_fn (in which case &struct request
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* automagically gets a tag assigned). Note that this function
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* assumes that any type of request can be queued! if this is not
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* true for your device, you must check the request type before
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* calling this function. The request will also be removed from
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* the request queue, so it's the drivers responsibility to readd
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* it if it should need to be restarted for some reason.
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*
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* Notes:
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* queue lock must be held.
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**/
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int blk_queue_start_tag(struct request_queue *q, struct request *rq)
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{
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struct blk_queue_tag *bqt = q->queue_tags;
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int tag;
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if (unlikely((rq->cmd_flags & REQ_QUEUED))) {
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printk(KERN_ERR
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"%s: request %p for device [%s] already tagged %d",
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__FUNCTION__, rq,
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rq->rq_disk ? rq->rq_disk->disk_name : "?", rq->tag);
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BUG();
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}
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/*
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* Protect against shared tag maps, as we may not have exclusive
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* access to the tag map.
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*/
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do {
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tag = find_first_zero_bit(bqt->tag_map, bqt->max_depth);
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if (tag >= bqt->max_depth)
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return 1;
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} while (test_and_set_bit_lock(tag, bqt->tag_map));
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/*
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* We need lock ordering semantics given by test_and_set_bit_lock.
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* See blk_queue_end_tag for details.
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*/
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rq->cmd_flags |= REQ_QUEUED;
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rq->tag = tag;
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bqt->tag_index[tag] = rq;
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blkdev_dequeue_request(rq);
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list_add(&rq->queuelist, &q->tag_busy_list);
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bqt->busy++;
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return 0;
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}
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EXPORT_SYMBOL(blk_queue_start_tag);
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/**
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* blk_queue_invalidate_tags - invalidate all pending tags
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* @q: the request queue for the device
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*
|
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* Description:
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* Hardware conditions may dictate a need to stop all pending requests.
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* In this case, we will safely clear the block side of the tag queue and
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* readd all requests to the request queue in the right order.
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*
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* Notes:
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* queue lock must be held.
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**/
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void blk_queue_invalidate_tags(struct request_queue *q)
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{
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struct list_head *tmp, *n;
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list_for_each_safe(tmp, n, &q->tag_busy_list)
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blk_requeue_request(q, list_entry_rq(tmp));
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}
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EXPORT_SYMBOL(blk_queue_invalidate_tags);
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void blk_dump_rq_flags(struct request *rq, char *msg)
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{
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int bit;
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|
|
@ -1828,41 +1421,6 @@ void blk_run_queue(struct request_queue *q)
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}
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EXPORT_SYMBOL(blk_run_queue);
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/**
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* blk_cleanup_queue: - release a &struct request_queue when it is no longer needed
|
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* @kobj: the kobj belonging of the request queue to be released
|
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*
|
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* Description:
|
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* blk_cleanup_queue is the pair to blk_init_queue() or
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* blk_queue_make_request(). It should be called when a request queue is
|
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* being released; typically when a block device is being de-registered.
|
||||
* Currently, its primary task it to free all the &struct request
|
||||
* structures that were allocated to the queue and the queue itself.
|
||||
*
|
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* Caveat:
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* Hopefully the low level driver will have finished any
|
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* outstanding requests first...
|
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**/
|
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static void blk_release_queue(struct kobject *kobj)
|
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{
|
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struct request_queue *q =
|
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container_of(kobj, struct request_queue, kobj);
|
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struct request_list *rl = &q->rq;
|
||||
|
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blk_sync_queue(q);
|
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|
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if (rl->rq_pool)
|
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mempool_destroy(rl->rq_pool);
|
||||
|
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if (q->queue_tags)
|
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__blk_queue_free_tags(q);
|
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|
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blk_trace_shutdown(q);
|
||||
|
||||
bdi_destroy(&q->backing_dev_info);
|
||||
kmem_cache_free(requestq_cachep, q);
|
||||
}
|
||||
|
||||
void blk_put_queue(struct request_queue *q)
|
||||
{
|
||||
kobject_put(&q->kobj);
|
||||
|
|
@ -1908,14 +1466,12 @@ struct request_queue *blk_alloc_queue(gfp_t gfp_mask)
|
|||
}
|
||||
EXPORT_SYMBOL(blk_alloc_queue);
|
||||
|
||||
static struct kobj_type queue_ktype;
|
||||
|
||||
struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
|
||||
{
|
||||
struct request_queue *q;
|
||||
int err;
|
||||
|
||||
q = kmem_cache_alloc_node(requestq_cachep,
|
||||
q = kmem_cache_alloc_node(blk_requestq_cachep,
|
||||
gfp_mask | __GFP_ZERO, node_id);
|
||||
if (!q)
|
||||
return NULL;
|
||||
|
|
@ -1924,13 +1480,13 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
|
|||
q->backing_dev_info.unplug_io_data = q;
|
||||
err = bdi_init(&q->backing_dev_info);
|
||||
if (err) {
|
||||
kmem_cache_free(requestq_cachep, q);
|
||||
kmem_cache_free(blk_requestq_cachep, q);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
init_timer(&q->unplug_timer);
|
||||
|
||||
kobject_init(&q->kobj, &queue_ktype);
|
||||
kobject_init(&q->kobj, &blk_queue_ktype);
|
||||
|
||||
mutex_init(&q->sysfs_lock);
|
||||
|
||||
|
|
@ -1987,7 +1543,7 @@ blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id)
|
|||
|
||||
q->node = node_id;
|
||||
if (blk_init_free_list(q)) {
|
||||
kmem_cache_free(requestq_cachep, q);
|
||||
kmem_cache_free(blk_requestq_cachep, q);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
|
|
@ -4012,7 +3568,7 @@ int __init blk_dev_init(void)
|
|||
request_cachep = kmem_cache_create("blkdev_requests",
|
||||
sizeof(struct request), 0, SLAB_PANIC, NULL);
|
||||
|
||||
requestq_cachep = kmem_cache_create("blkdev_queue",
|
||||
blk_requestq_cachep = kmem_cache_create("blkdev_queue",
|
||||
sizeof(struct request_queue), 0, SLAB_PANIC, NULL);
|
||||
|
||||
iocontext_cachep = kmem_cache_create("blkdev_ioc",
|
||||
|
|
@ -4200,258 +3756,3 @@ void swap_io_context(struct io_context **ioc1, struct io_context **ioc2)
|
|||
}
|
||||
EXPORT_SYMBOL(swap_io_context);
|
||||
|
||||
/*
|
||||
* sysfs parts below
|
||||
*/
|
||||
struct queue_sysfs_entry {
|
||||
struct attribute attr;
|
||||
ssize_t (*show)(struct request_queue *, char *);
|
||||
ssize_t (*store)(struct request_queue *, const char *, size_t);
|
||||
};
|
||||
|
||||
static ssize_t
|
||||
queue_var_show(unsigned int var, char *page)
|
||||
{
|
||||
return sprintf(page, "%d\n", var);
|
||||
}
|
||||
|
||||
static ssize_t
|
||||
queue_var_store(unsigned long *var, const char *page, size_t count)
|
||||
{
|
||||
char *p = (char *) page;
|
||||
|
||||
*var = simple_strtoul(p, &p, 10);
|
||||
return count;
|
||||
}
|
||||
|
||||
static ssize_t queue_requests_show(struct request_queue *q, char *page)
|
||||
{
|
||||
return queue_var_show(q->nr_requests, (page));
|
||||
}
|
||||
|
||||
static ssize_t
|
||||
queue_requests_store(struct request_queue *q, const char *page, size_t count)
|
||||
{
|
||||
struct request_list *rl = &q->rq;
|
||||
unsigned long nr;
|
||||
int ret = queue_var_store(&nr, page, count);
|
||||
if (nr < BLKDEV_MIN_RQ)
|
||||
nr = BLKDEV_MIN_RQ;
|
||||
|
||||
spin_lock_irq(q->queue_lock);
|
||||
q->nr_requests = nr;
|
||||
blk_queue_congestion_threshold(q);
|
||||
|
||||
if (rl->count[READ] >= queue_congestion_on_threshold(q))
|
||||
blk_set_queue_congested(q, READ);
|
||||
else if (rl->count[READ] < queue_congestion_off_threshold(q))
|
||||
blk_clear_queue_congested(q, READ);
|
||||
|
||||
if (rl->count[WRITE] >= queue_congestion_on_threshold(q))
|
||||
blk_set_queue_congested(q, WRITE);
|
||||
else if (rl->count[WRITE] < queue_congestion_off_threshold(q))
|
||||
blk_clear_queue_congested(q, WRITE);
|
||||
|
||||
if (rl->count[READ] >= q->nr_requests) {
|
||||
blk_set_queue_full(q, READ);
|
||||
} else if (rl->count[READ]+1 <= q->nr_requests) {
|
||||
blk_clear_queue_full(q, READ);
|
||||
wake_up(&rl->wait[READ]);
|
||||
}
|
||||
|
||||
if (rl->count[WRITE] >= q->nr_requests) {
|
||||
blk_set_queue_full(q, WRITE);
|
||||
} else if (rl->count[WRITE]+1 <= q->nr_requests) {
|
||||
blk_clear_queue_full(q, WRITE);
|
||||
wake_up(&rl->wait[WRITE]);
|
||||
}
|
||||
spin_unlock_irq(q->queue_lock);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static ssize_t queue_ra_show(struct request_queue *q, char *page)
|
||||
{
|
||||
int ra_kb = q->backing_dev_info.ra_pages << (PAGE_CACHE_SHIFT - 10);
|
||||
|
||||
return queue_var_show(ra_kb, (page));
|
||||
}
|
||||
|
||||
static ssize_t
|
||||
queue_ra_store(struct request_queue *q, const char *page, size_t count)
|
||||
{
|
||||
unsigned long ra_kb;
|
||||
ssize_t ret = queue_var_store(&ra_kb, page, count);
|
||||
|
||||
spin_lock_irq(q->queue_lock);
|
||||
q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
|
||||
spin_unlock_irq(q->queue_lock);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
|
||||
{
|
||||
int max_sectors_kb = q->max_sectors >> 1;
|
||||
|
||||
return queue_var_show(max_sectors_kb, (page));
|
||||
}
|
||||
|
||||
static ssize_t
|
||||
queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
|
||||
{
|
||||
unsigned long max_sectors_kb,
|
||||
max_hw_sectors_kb = q->max_hw_sectors >> 1,
|
||||
page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
|
||||
ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
|
||||
|
||||
if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
|
||||
return -EINVAL;
|
||||
/*
|
||||
* Take the queue lock to update the readahead and max_sectors
|
||||
* values synchronously:
|
||||
*/
|
||||
spin_lock_irq(q->queue_lock);
|
||||
q->max_sectors = max_sectors_kb << 1;
|
||||
spin_unlock_irq(q->queue_lock);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
|
||||
{
|
||||
int max_hw_sectors_kb = q->max_hw_sectors >> 1;
|
||||
|
||||
return queue_var_show(max_hw_sectors_kb, (page));
|
||||
}
|
||||
|
||||
|
||||
static struct queue_sysfs_entry queue_requests_entry = {
|
||||
.attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
|
||||
.show = queue_requests_show,
|
||||
.store = queue_requests_store,
|
||||
};
|
||||
|
||||
static struct queue_sysfs_entry queue_ra_entry = {
|
||||
.attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
|
||||
.show = queue_ra_show,
|
||||
.store = queue_ra_store,
|
||||
};
|
||||
|
||||
static struct queue_sysfs_entry queue_max_sectors_entry = {
|
||||
.attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
|
||||
.show = queue_max_sectors_show,
|
||||
.store = queue_max_sectors_store,
|
||||
};
|
||||
|
||||
static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
|
||||
.attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
|
||||
.show = queue_max_hw_sectors_show,
|
||||
};
|
||||
|
||||
static struct queue_sysfs_entry queue_iosched_entry = {
|
||||
.attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
|
||||
.show = elv_iosched_show,
|
||||
.store = elv_iosched_store,
|
||||
};
|
||||
|
||||
static struct attribute *default_attrs[] = {
|
||||
&queue_requests_entry.attr,
|
||||
&queue_ra_entry.attr,
|
||||
&queue_max_hw_sectors_entry.attr,
|
||||
&queue_max_sectors_entry.attr,
|
||||
&queue_iosched_entry.attr,
|
||||
NULL,
|
||||
};
|
||||
|
||||
#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
|
||||
|
||||
static ssize_t
|
||||
queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
|
||||
{
|
||||
struct queue_sysfs_entry *entry = to_queue(attr);
|
||||
struct request_queue *q =
|
||||
container_of(kobj, struct request_queue, kobj);
|
||||
ssize_t res;
|
||||
|
||||
if (!entry->show)
|
||||
return -EIO;
|
||||
mutex_lock(&q->sysfs_lock);
|
||||
if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
|
||||
mutex_unlock(&q->sysfs_lock);
|
||||
return -ENOENT;
|
||||
}
|
||||
res = entry->show(q, page);
|
||||
mutex_unlock(&q->sysfs_lock);
|
||||
return res;
|
||||
}
|
||||
|
||||
static ssize_t
|
||||
queue_attr_store(struct kobject *kobj, struct attribute *attr,
|
||||
const char *page, size_t length)
|
||||
{
|
||||
struct queue_sysfs_entry *entry = to_queue(attr);
|
||||
struct request_queue *q = container_of(kobj, struct request_queue, kobj);
|
||||
|
||||
ssize_t res;
|
||||
|
||||
if (!entry->store)
|
||||
return -EIO;
|
||||
mutex_lock(&q->sysfs_lock);
|
||||
if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
|
||||
mutex_unlock(&q->sysfs_lock);
|
||||
return -ENOENT;
|
||||
}
|
||||
res = entry->store(q, page, length);
|
||||
mutex_unlock(&q->sysfs_lock);
|
||||
return res;
|
||||
}
|
||||
|
||||
static struct sysfs_ops queue_sysfs_ops = {
|
||||
.show = queue_attr_show,
|
||||
.store = queue_attr_store,
|
||||
};
|
||||
|
||||
static struct kobj_type queue_ktype = {
|
||||
.sysfs_ops = &queue_sysfs_ops,
|
||||
.default_attrs = default_attrs,
|
||||
.release = blk_release_queue,
|
||||
};
|
||||
|
||||
int blk_register_queue(struct gendisk *disk)
|
||||
{
|
||||
int ret;
|
||||
|
||||
struct request_queue *q = disk->queue;
|
||||
|
||||
if (!q || !q->request_fn)
|
||||
return -ENXIO;
|
||||
|
||||
ret = kobject_add(&q->kobj, kobject_get(&disk->dev.kobj),
|
||||
"%s", "queue");
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
kobject_uevent(&q->kobj, KOBJ_ADD);
|
||||
|
||||
ret = elv_register_queue(q);
|
||||
if (ret) {
|
||||
kobject_uevent(&q->kobj, KOBJ_REMOVE);
|
||||
kobject_del(&q->kobj);
|
||||
return ret;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
void blk_unregister_queue(struct gendisk *disk)
|
||||
{
|
||||
struct request_queue *q = disk->queue;
|
||||
|
||||
if (q && q->request_fn) {
|
||||
elv_unregister_queue(q);
|
||||
|
||||
kobject_uevent(&q->kobj, KOBJ_REMOVE);
|
||||
kobject_del(&q->kobj);
|
||||
kobject_put(&disk->dev.kobj);
|
||||
}
|
||||
}
|
||||
|
|
|
|||
|
|
@ -0,0 +1,298 @@
|
|||
/*
|
||||
* Functions related to sysfs handling
|
||||
*/
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/bio.h>
|
||||
#include <linux/blkdev.h>
|
||||
#include <linux/blktrace_api.h>
|
||||
|
||||
#include "blk.h"
|
||||
|
||||
struct queue_sysfs_entry {
|
||||
struct attribute attr;
|
||||
ssize_t (*show)(struct request_queue *, char *);
|
||||
ssize_t (*store)(struct request_queue *, const char *, size_t);
|
||||
};
|
||||
|
||||
static ssize_t
|
||||
queue_var_show(unsigned int var, char *page)
|
||||
{
|
||||
return sprintf(page, "%d\n", var);
|
||||
}
|
||||
|
||||
static ssize_t
|
||||
queue_var_store(unsigned long *var, const char *page, size_t count)
|
||||
{
|
||||
char *p = (char *) page;
|
||||
|
||||
*var = simple_strtoul(p, &p, 10);
|
||||
return count;
|
||||
}
|
||||
|
||||
static ssize_t queue_requests_show(struct request_queue *q, char *page)
|
||||
{
|
||||
return queue_var_show(q->nr_requests, (page));
|
||||
}
|
||||
|
||||
static ssize_t
|
||||
queue_requests_store(struct request_queue *q, const char *page, size_t count)
|
||||
{
|
||||
struct request_list *rl = &q->rq;
|
||||
unsigned long nr;
|
||||
int ret = queue_var_store(&nr, page, count);
|
||||
if (nr < BLKDEV_MIN_RQ)
|
||||
nr = BLKDEV_MIN_RQ;
|
||||
|
||||
spin_lock_irq(q->queue_lock);
|
||||
q->nr_requests = nr;
|
||||
blk_queue_congestion_threshold(q);
|
||||
|
||||
if (rl->count[READ] >= queue_congestion_on_threshold(q))
|
||||
blk_set_queue_congested(q, READ);
|
||||
else if (rl->count[READ] < queue_congestion_off_threshold(q))
|
||||
blk_clear_queue_congested(q, READ);
|
||||
|
||||
if (rl->count[WRITE] >= queue_congestion_on_threshold(q))
|
||||
blk_set_queue_congested(q, WRITE);
|
||||
else if (rl->count[WRITE] < queue_congestion_off_threshold(q))
|
||||
blk_clear_queue_congested(q, WRITE);
|
||||
|
||||
if (rl->count[READ] >= q->nr_requests) {
|
||||
blk_set_queue_full(q, READ);
|
||||
} else if (rl->count[READ]+1 <= q->nr_requests) {
|
||||
blk_clear_queue_full(q, READ);
|
||||
wake_up(&rl->wait[READ]);
|
||||
}
|
||||
|
||||
if (rl->count[WRITE] >= q->nr_requests) {
|
||||
blk_set_queue_full(q, WRITE);
|
||||
} else if (rl->count[WRITE]+1 <= q->nr_requests) {
|
||||
blk_clear_queue_full(q, WRITE);
|
||||
wake_up(&rl->wait[WRITE]);
|
||||
}
|
||||
spin_unlock_irq(q->queue_lock);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static ssize_t queue_ra_show(struct request_queue *q, char *page)
|
||||
{
|
||||
int ra_kb = q->backing_dev_info.ra_pages << (PAGE_CACHE_SHIFT - 10);
|
||||
|
||||
return queue_var_show(ra_kb, (page));
|
||||
}
|
||||
|
||||
static ssize_t
|
||||
queue_ra_store(struct request_queue *q, const char *page, size_t count)
|
||||
{
|
||||
unsigned long ra_kb;
|
||||
ssize_t ret = queue_var_store(&ra_kb, page, count);
|
||||
|
||||
spin_lock_irq(q->queue_lock);
|
||||
q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
|
||||
spin_unlock_irq(q->queue_lock);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
|
||||
{
|
||||
int max_sectors_kb = q->max_sectors >> 1;
|
||||
|
||||
return queue_var_show(max_sectors_kb, (page));
|
||||
}
|
||||
|
||||
static ssize_t
|
||||
queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
|
||||
{
|
||||
unsigned long max_sectors_kb,
|
||||
max_hw_sectors_kb = q->max_hw_sectors >> 1,
|
||||
page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
|
||||
ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
|
||||
|
||||
if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
|
||||
return -EINVAL;
|
||||
/*
|
||||
* Take the queue lock to update the readahead and max_sectors
|
||||
* values synchronously:
|
||||
*/
|
||||
spin_lock_irq(q->queue_lock);
|
||||
q->max_sectors = max_sectors_kb << 1;
|
||||
spin_unlock_irq(q->queue_lock);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
|
||||
{
|
||||
int max_hw_sectors_kb = q->max_hw_sectors >> 1;
|
||||
|
||||
return queue_var_show(max_hw_sectors_kb, (page));
|
||||
}
|
||||
|
||||
|
||||
static struct queue_sysfs_entry queue_requests_entry = {
|
||||
.attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
|
||||
.show = queue_requests_show,
|
||||
.store = queue_requests_store,
|
||||
};
|
||||
|
||||
static struct queue_sysfs_entry queue_ra_entry = {
|
||||
.attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
|
||||
.show = queue_ra_show,
|
||||
.store = queue_ra_store,
|
||||
};
|
||||
|
||||
static struct queue_sysfs_entry queue_max_sectors_entry = {
|
||||
.attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
|
||||
.show = queue_max_sectors_show,
|
||||
.store = queue_max_sectors_store,
|
||||
};
|
||||
|
||||
static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
|
||||
.attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
|
||||
.show = queue_max_hw_sectors_show,
|
||||
};
|
||||
|
||||
static struct queue_sysfs_entry queue_iosched_entry = {
|
||||
.attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
|
||||
.show = elv_iosched_show,
|
||||
.store = elv_iosched_store,
|
||||
};
|
||||
|
||||
static struct attribute *default_attrs[] = {
|
||||
&queue_requests_entry.attr,
|
||||
&queue_ra_entry.attr,
|
||||
&queue_max_hw_sectors_entry.attr,
|
||||
&queue_max_sectors_entry.attr,
|
||||
&queue_iosched_entry.attr,
|
||||
NULL,
|
||||
};
|
||||
|
||||
#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
|
||||
|
||||
static ssize_t
|
||||
queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
|
||||
{
|
||||
struct queue_sysfs_entry *entry = to_queue(attr);
|
||||
struct request_queue *q =
|
||||
container_of(kobj, struct request_queue, kobj);
|
||||
ssize_t res;
|
||||
|
||||
if (!entry->show)
|
||||
return -EIO;
|
||||
mutex_lock(&q->sysfs_lock);
|
||||
if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
|
||||
mutex_unlock(&q->sysfs_lock);
|
||||
return -ENOENT;
|
||||
}
|
||||
res = entry->show(q, page);
|
||||
mutex_unlock(&q->sysfs_lock);
|
||||
return res;
|
||||
}
|
||||
|
||||
static ssize_t
|
||||
queue_attr_store(struct kobject *kobj, struct attribute *attr,
|
||||
const char *page, size_t length)
|
||||
{
|
||||
struct queue_sysfs_entry *entry = to_queue(attr);
|
||||
struct request_queue *q = container_of(kobj, struct request_queue, kobj);
|
||||
|
||||
ssize_t res;
|
||||
|
||||
if (!entry->store)
|
||||
return -EIO;
|
||||
mutex_lock(&q->sysfs_lock);
|
||||
if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
|
||||
mutex_unlock(&q->sysfs_lock);
|
||||
return -ENOENT;
|
||||
}
|
||||
res = entry->store(q, page, length);
|
||||
mutex_unlock(&q->sysfs_lock);
|
||||
return res;
|
||||
}
|
||||
|
||||
/**
|
||||
* blk_cleanup_queue: - release a &struct request_queue when it is no longer needed
|
||||
* @kobj: the kobj belonging of the request queue to be released
|
||||
*
|
||||
* Description:
|
||||
* blk_cleanup_queue is the pair to blk_init_queue() or
|
||||
* blk_queue_make_request(). It should be called when a request queue is
|
||||
* being released; typically when a block device is being de-registered.
|
||||
* Currently, its primary task it to free all the &struct request
|
||||
* structures that were allocated to the queue and the queue itself.
|
||||
*
|
||||
* Caveat:
|
||||
* Hopefully the low level driver will have finished any
|
||||
* outstanding requests first...
|
||||
**/
|
||||
static void blk_release_queue(struct kobject *kobj)
|
||||
{
|
||||
struct request_queue *q =
|
||||
container_of(kobj, struct request_queue, kobj);
|
||||
struct request_list *rl = &q->rq;
|
||||
|
||||
blk_sync_queue(q);
|
||||
|
||||
if (rl->rq_pool)
|
||||
mempool_destroy(rl->rq_pool);
|
||||
|
||||
if (q->queue_tags)
|
||||
__blk_queue_free_tags(q);
|
||||
|
||||
blk_trace_shutdown(q);
|
||||
|
||||
bdi_destroy(&q->backing_dev_info);
|
||||
kmem_cache_free(blk_requestq_cachep, q);
|
||||
}
|
||||
|
||||
static struct sysfs_ops queue_sysfs_ops = {
|
||||
.show = queue_attr_show,
|
||||
.store = queue_attr_store,
|
||||
};
|
||||
|
||||
struct kobj_type blk_queue_ktype = {
|
||||
.sysfs_ops = &queue_sysfs_ops,
|
||||
.default_attrs = default_attrs,
|
||||
.release = blk_release_queue,
|
||||
};
|
||||
|
||||
int blk_register_queue(struct gendisk *disk)
|
||||
{
|
||||
int ret;
|
||||
|
||||
struct request_queue *q = disk->queue;
|
||||
|
||||
if (!q || !q->request_fn)
|
||||
return -ENXIO;
|
||||
|
||||
ret = kobject_add(&q->kobj, kobject_get(&disk->dev.kobj),
|
||||
"%s", "queue");
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
kobject_uevent(&q->kobj, KOBJ_ADD);
|
||||
|
||||
ret = elv_register_queue(q);
|
||||
if (ret) {
|
||||
kobject_uevent(&q->kobj, KOBJ_REMOVE);
|
||||
kobject_del(&q->kobj);
|
||||
return ret;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
void blk_unregister_queue(struct gendisk *disk)
|
||||
{
|
||||
struct request_queue *q = disk->queue;
|
||||
|
||||
if (q && q->request_fn) {
|
||||
elv_unregister_queue(q);
|
||||
|
||||
kobject_uevent(&q->kobj, KOBJ_REMOVE);
|
||||
kobject_del(&q->kobj);
|
||||
kobject_put(&disk->dev.kobj);
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,396 @@
|
|||
/*
|
||||
* Functions related to tagged command queuing
|
||||
*/
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/bio.h>
|
||||
#include <linux/blkdev.h>
|
||||
|
||||
/**
|
||||
* blk_queue_find_tag - find a request by its tag and queue
|
||||
* @q: The request queue for the device
|
||||
* @tag: The tag of the request
|
||||
*
|
||||
* Notes:
|
||||
* Should be used when a device returns a tag and you want to match
|
||||
* it with a request.
|
||||
*
|
||||
* no locks need be held.
|
||||
**/
|
||||
struct request *blk_queue_find_tag(struct request_queue *q, int tag)
|
||||
{
|
||||
return blk_map_queue_find_tag(q->queue_tags, tag);
|
||||
}
|
||||
|
||||
EXPORT_SYMBOL(blk_queue_find_tag);
|
||||
|
||||
/**
|
||||
* __blk_free_tags - release a given set of tag maintenance info
|
||||
* @bqt: the tag map to free
|
||||
*
|
||||
* Tries to free the specified @bqt@. Returns true if it was
|
||||
* actually freed and false if there are still references using it
|
||||
*/
|
||||
static int __blk_free_tags(struct blk_queue_tag *bqt)
|
||||
{
|
||||
int retval;
|
||||
|
||||
retval = atomic_dec_and_test(&bqt->refcnt);
|
||||
if (retval) {
|
||||
BUG_ON(bqt->busy);
|
||||
|
||||
kfree(bqt->tag_index);
|
||||
bqt->tag_index = NULL;
|
||||
|
||||
kfree(bqt->tag_map);
|
||||
bqt->tag_map = NULL;
|
||||
|
||||
kfree(bqt);
|
||||
}
|
||||
|
||||
return retval;
|
||||
}
|
||||
|
||||
/**
|
||||
* __blk_queue_free_tags - release tag maintenance info
|
||||
* @q: the request queue for the device
|
||||
*
|
||||
* Notes:
|
||||
* blk_cleanup_queue() will take care of calling this function, if tagging
|
||||
* has been used. So there's no need to call this directly.
|
||||
**/
|
||||
void __blk_queue_free_tags(struct request_queue *q)
|
||||
{
|
||||
struct blk_queue_tag *bqt = q->queue_tags;
|
||||
|
||||
if (!bqt)
|
||||
return;
|
||||
|
||||
__blk_free_tags(bqt);
|
||||
|
||||
q->queue_tags = NULL;
|
||||
q->queue_flags &= ~(1 << QUEUE_FLAG_QUEUED);
|
||||
}
|
||||
|
||||
/**
|
||||
* blk_free_tags - release a given set of tag maintenance info
|
||||
* @bqt: the tag map to free
|
||||
*
|
||||
* For externally managed @bqt@ frees the map. Callers of this
|
||||
* function must guarantee to have released all the queues that
|
||||
* might have been using this tag map.
|
||||
*/
|
||||
void blk_free_tags(struct blk_queue_tag *bqt)
|
||||
{
|
||||
if (unlikely(!__blk_free_tags(bqt)))
|
||||
BUG();
|
||||
}
|
||||
EXPORT_SYMBOL(blk_free_tags);
|
||||
|
||||
/**
|
||||
* blk_queue_free_tags - release tag maintenance info
|
||||
* @q: the request queue for the device
|
||||
*
|
||||
* Notes:
|
||||
* This is used to disabled tagged queuing to a device, yet leave
|
||||
* queue in function.
|
||||
**/
|
||||
void blk_queue_free_tags(struct request_queue *q)
|
||||
{
|
||||
clear_bit(QUEUE_FLAG_QUEUED, &q->queue_flags);
|
||||
}
|
||||
|
||||
EXPORT_SYMBOL(blk_queue_free_tags);
|
||||
|
||||
static int
|
||||
init_tag_map(struct request_queue *q, struct blk_queue_tag *tags, int depth)
|
||||
{
|
||||
struct request **tag_index;
|
||||
unsigned long *tag_map;
|
||||
int nr_ulongs;
|
||||
|
||||
if (q && depth > q->nr_requests * 2) {
|
||||
depth = q->nr_requests * 2;
|
||||
printk(KERN_ERR "%s: adjusted depth to %d\n",
|
||||
__FUNCTION__, depth);
|
||||
}
|
||||
|
||||
tag_index = kzalloc(depth * sizeof(struct request *), GFP_ATOMIC);
|
||||
if (!tag_index)
|
||||
goto fail;
|
||||
|
||||
nr_ulongs = ALIGN(depth, BITS_PER_LONG) / BITS_PER_LONG;
|
||||
tag_map = kzalloc(nr_ulongs * sizeof(unsigned long), GFP_ATOMIC);
|
||||
if (!tag_map)
|
||||
goto fail;
|
||||
|
||||
tags->real_max_depth = depth;
|
||||
tags->max_depth = depth;
|
||||
tags->tag_index = tag_index;
|
||||
tags->tag_map = tag_map;
|
||||
|
||||
return 0;
|
||||
fail:
|
||||
kfree(tag_index);
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
static struct blk_queue_tag *__blk_queue_init_tags(struct request_queue *q,
|
||||
int depth)
|
||||
{
|
||||
struct blk_queue_tag *tags;
|
||||
|
||||
tags = kmalloc(sizeof(struct blk_queue_tag), GFP_ATOMIC);
|
||||
if (!tags)
|
||||
goto fail;
|
||||
|
||||
if (init_tag_map(q, tags, depth))
|
||||
goto fail;
|
||||
|
||||
tags->busy = 0;
|
||||
atomic_set(&tags->refcnt, 1);
|
||||
return tags;
|
||||
fail:
|
||||
kfree(tags);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
/**
|
||||
* blk_init_tags - initialize the tag info for an external tag map
|
||||
* @depth: the maximum queue depth supported
|
||||
* @tags: the tag to use
|
||||
**/
|
||||
struct blk_queue_tag *blk_init_tags(int depth)
|
||||
{
|
||||
return __blk_queue_init_tags(NULL, depth);
|
||||
}
|
||||
EXPORT_SYMBOL(blk_init_tags);
|
||||
|
||||
/**
|
||||
* blk_queue_init_tags - initialize the queue tag info
|
||||
* @q: the request queue for the device
|
||||
* @depth: the maximum queue depth supported
|
||||
* @tags: the tag to use
|
||||
**/
|
||||
int blk_queue_init_tags(struct request_queue *q, int depth,
|
||||
struct blk_queue_tag *tags)
|
||||
{
|
||||
int rc;
|
||||
|
||||
BUG_ON(tags && q->queue_tags && tags != q->queue_tags);
|
||||
|
||||
if (!tags && !q->queue_tags) {
|
||||
tags = __blk_queue_init_tags(q, depth);
|
||||
|
||||
if (!tags)
|
||||
goto fail;
|
||||
} else if (q->queue_tags) {
|
||||
if ((rc = blk_queue_resize_tags(q, depth)))
|
||||
return rc;
|
||||
set_bit(QUEUE_FLAG_QUEUED, &q->queue_flags);
|
||||
return 0;
|
||||
} else
|
||||
atomic_inc(&tags->refcnt);
|
||||
|
||||
/*
|
||||
* assign it, all done
|
||||
*/
|
||||
q->queue_tags = tags;
|
||||
q->queue_flags |= (1 << QUEUE_FLAG_QUEUED);
|
||||
INIT_LIST_HEAD(&q->tag_busy_list);
|
||||
return 0;
|
||||
fail:
|
||||
kfree(tags);
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
EXPORT_SYMBOL(blk_queue_init_tags);
|
||||
|
||||
/**
|
||||
* blk_queue_resize_tags - change the queueing depth
|
||||
* @q: the request queue for the device
|
||||
* @new_depth: the new max command queueing depth
|
||||
*
|
||||
* Notes:
|
||||
* Must be called with the queue lock held.
|
||||
**/
|
||||
int blk_queue_resize_tags(struct request_queue *q, int new_depth)
|
||||
{
|
||||
struct blk_queue_tag *bqt = q->queue_tags;
|
||||
struct request **tag_index;
|
||||
unsigned long *tag_map;
|
||||
int max_depth, nr_ulongs;
|
||||
|
||||
if (!bqt)
|
||||
return -ENXIO;
|
||||
|
||||
/*
|
||||
* if we already have large enough real_max_depth. just
|
||||
* adjust max_depth. *NOTE* as requests with tag value
|
||||
* between new_depth and real_max_depth can be in-flight, tag
|
||||
* map can not be shrunk blindly here.
|
||||
*/
|
||||
if (new_depth <= bqt->real_max_depth) {
|
||||
bqt->max_depth = new_depth;
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Currently cannot replace a shared tag map with a new
|
||||
* one, so error out if this is the case
|
||||
*/
|
||||
if (atomic_read(&bqt->refcnt) != 1)
|
||||
return -EBUSY;
|
||||
|
||||
/*
|
||||
* save the old state info, so we can copy it back
|
||||
*/
|
||||
tag_index = bqt->tag_index;
|
||||
tag_map = bqt->tag_map;
|
||||
max_depth = bqt->real_max_depth;
|
||||
|
||||
if (init_tag_map(q, bqt, new_depth))
|
||||
return -ENOMEM;
|
||||
|
||||
memcpy(bqt->tag_index, tag_index, max_depth * sizeof(struct request *));
|
||||
nr_ulongs = ALIGN(max_depth, BITS_PER_LONG) / BITS_PER_LONG;
|
||||
memcpy(bqt->tag_map, tag_map, nr_ulongs * sizeof(unsigned long));
|
||||
|
||||
kfree(tag_index);
|
||||
kfree(tag_map);
|
||||
return 0;
|
||||
}
|
||||
|
||||
EXPORT_SYMBOL(blk_queue_resize_tags);
|
||||
|
||||
/**
|
||||
* blk_queue_end_tag - end tag operations for a request
|
||||
* @q: the request queue for the device
|
||||
* @rq: the request that has completed
|
||||
*
|
||||
* Description:
|
||||
* Typically called when end_that_request_first() returns 0, meaning
|
||||
* all transfers have been done for a request. It's important to call
|
||||
* this function before end_that_request_last(), as that will put the
|
||||
* request back on the free list thus corrupting the internal tag list.
|
||||
*
|
||||
* Notes:
|
||||
* queue lock must be held.
|
||||
**/
|
||||
void blk_queue_end_tag(struct request_queue *q, struct request *rq)
|
||||
{
|
||||
struct blk_queue_tag *bqt = q->queue_tags;
|
||||
int tag = rq->tag;
|
||||
|
||||
BUG_ON(tag == -1);
|
||||
|
||||
if (unlikely(tag >= bqt->real_max_depth))
|
||||
/*
|
||||
* This can happen after tag depth has been reduced.
|
||||
* FIXME: how about a warning or info message here?
|
||||
*/
|
||||
return;
|
||||
|
||||
list_del_init(&rq->queuelist);
|
||||
rq->cmd_flags &= ~REQ_QUEUED;
|
||||
rq->tag = -1;
|
||||
|
||||
if (unlikely(bqt->tag_index[tag] == NULL))
|
||||
printk(KERN_ERR "%s: tag %d is missing\n",
|
||||
__FUNCTION__, tag);
|
||||
|
||||
bqt->tag_index[tag] = NULL;
|
||||
|
||||
if (unlikely(!test_bit(tag, bqt->tag_map))) {
|
||||
printk(KERN_ERR "%s: attempt to clear non-busy tag (%d)\n",
|
||||
__FUNCTION__, tag);
|
||||
return;
|
||||
}
|
||||
/*
|
||||
* The tag_map bit acts as a lock for tag_index[bit], so we need
|
||||
* unlock memory barrier semantics.
|
||||
*/
|
||||
clear_bit_unlock(tag, bqt->tag_map);
|
||||
bqt->busy--;
|
||||
}
|
||||
|
||||
EXPORT_SYMBOL(blk_queue_end_tag);
|
||||
|
||||
/**
|
||||
* blk_queue_start_tag - find a free tag and assign it
|
||||
* @q: the request queue for the device
|
||||
* @rq: the block request that needs tagging
|
||||
*
|
||||
* Description:
|
||||
* This can either be used as a stand-alone helper, or possibly be
|
||||
* assigned as the queue &prep_rq_fn (in which case &struct request
|
||||
* automagically gets a tag assigned). Note that this function
|
||||
* assumes that any type of request can be queued! if this is not
|
||||
* true for your device, you must check the request type before
|
||||
* calling this function. The request will also be removed from
|
||||
* the request queue, so it's the drivers responsibility to readd
|
||||
* it if it should need to be restarted for some reason.
|
||||
*
|
||||
* Notes:
|
||||
* queue lock must be held.
|
||||
**/
|
||||
int blk_queue_start_tag(struct request_queue *q, struct request *rq)
|
||||
{
|
||||
struct blk_queue_tag *bqt = q->queue_tags;
|
||||
int tag;
|
||||
|
||||
if (unlikely((rq->cmd_flags & REQ_QUEUED))) {
|
||||
printk(KERN_ERR
|
||||
"%s: request %p for device [%s] already tagged %d",
|
||||
__FUNCTION__, rq,
|
||||
rq->rq_disk ? rq->rq_disk->disk_name : "?", rq->tag);
|
||||
BUG();
|
||||
}
|
||||
|
||||
/*
|
||||
* Protect against shared tag maps, as we may not have exclusive
|
||||
* access to the tag map.
|
||||
*/
|
||||
do {
|
||||
tag = find_first_zero_bit(bqt->tag_map, bqt->max_depth);
|
||||
if (tag >= bqt->max_depth)
|
||||
return 1;
|
||||
|
||||
} while (test_and_set_bit_lock(tag, bqt->tag_map));
|
||||
/*
|
||||
* We need lock ordering semantics given by test_and_set_bit_lock.
|
||||
* See blk_queue_end_tag for details.
|
||||
*/
|
||||
|
||||
rq->cmd_flags |= REQ_QUEUED;
|
||||
rq->tag = tag;
|
||||
bqt->tag_index[tag] = rq;
|
||||
blkdev_dequeue_request(rq);
|
||||
list_add(&rq->queuelist, &q->tag_busy_list);
|
||||
bqt->busy++;
|
||||
return 0;
|
||||
}
|
||||
|
||||
EXPORT_SYMBOL(blk_queue_start_tag);
|
||||
|
||||
/**
|
||||
* blk_queue_invalidate_tags - invalidate all pending tags
|
||||
* @q: the request queue for the device
|
||||
*
|
||||
* Description:
|
||||
* Hardware conditions may dictate a need to stop all pending requests.
|
||||
* In this case, we will safely clear the block side of the tag queue and
|
||||
* readd all requests to the request queue in the right order.
|
||||
*
|
||||
* Notes:
|
||||
* queue lock must be held.
|
||||
**/
|
||||
void blk_queue_invalidate_tags(struct request_queue *q)
|
||||
{
|
||||
struct list_head *tmp, *n;
|
||||
|
||||
list_for_each_safe(tmp, n, &q->tag_busy_list)
|
||||
blk_requeue_request(q, list_entry_rq(tmp));
|
||||
}
|
||||
|
||||
EXPORT_SYMBOL(blk_queue_invalidate_tags);
|
||||
|
|
@ -0,0 +1,29 @@
|
|||
#ifndef BLK_INTERNAL_H
|
||||
#define BLK_INTERNAL_H
|
||||
|
||||
extern struct kmem_cache *blk_requestq_cachep;
|
||||
extern struct kobj_type blk_queue_ktype;
|
||||
|
||||
void __blk_queue_free_tags(struct request_queue *q);
|
||||
|
||||
void blk_queue_congestion_threshold(struct request_queue *q);
|
||||
|
||||
/*
|
||||
* Return the threshold (number of used requests) at which the queue is
|
||||
* considered to be congested. It include a little hysteresis to keep the
|
||||
* context switch rate down.
|
||||
*/
|
||||
static inline int queue_congestion_on_threshold(struct request_queue *q)
|
||||
{
|
||||
return q->nr_congestion_on;
|
||||
}
|
||||
|
||||
/*
|
||||
* The threshold at which a queue is considered to be uncongested
|
||||
*/
|
||||
static inline int queue_congestion_off_threshold(struct request_queue *q)
|
||||
{
|
||||
return q->nr_congestion_off;
|
||||
}
|
||||
|
||||
#endif
|
||||
Loading…
Reference in New Issue