/*
* This handles all read/write requests to block devices
*/
-#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/backing-dev.h>
#include <linux/writeback.h>
#include <linux/interrupt.h>
#include <linux/cpu.h>
+#include <linux/blktrace_api.h>
/*
* for max sense size
* blk_queue_ordered - does this queue support ordered writes
* @q: the request queue
* @ordered: one of QUEUE_ORDERED_*
+ * @prepare_flush_fn: rq setup helper for cache flush ordered writes
*
* Description:
* For journalled file systems, doing ordered writes on a commit
return -EINVAL;
}
+ q->ordered = ordered;
q->next_ordered = ordered;
q->prepare_flush_fn = prepare_flush_fn;
rq->end_io = end_io;
q->prepare_flush_fn(q, rq);
- __elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0);
+ elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
}
static inline struct request *start_ordered(request_queue_t *q,
else
q->ordseq |= QUEUE_ORDSEQ_POSTFLUSH;
- __elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0);
+ elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
if (q->ordered & QUEUE_ORDERED_PREFLUSH) {
queue_flush(q, QUEUE_ORDERED_PREFLUSH);
int blk_do_ordered(request_queue_t *q, struct request **rqp)
{
- struct request *rq = *rqp, *allowed_rq;
+ struct request *rq = *rqp;
int is_barrier = blk_fs_request(rq) && blk_barrier_rq(rq);
if (!q->ordseq) {
}
}
+ /*
+ * Ordered sequence in progress
+ */
+
+ /* Special requests are not subject to ordering rules. */
+ if (!blk_fs_request(rq) &&
+ rq != &q->pre_flush_rq && rq != &q->post_flush_rq)
+ return 1;
+
if (q->ordered & QUEUE_ORDERED_TAG) {
+ /* Ordered by tag. Blocking the next barrier is enough. */
if (is_barrier && rq != &q->bar_rq)
*rqp = NULL;
- return 1;
- }
-
- switch (blk_ordered_cur_seq(q)) {
- case QUEUE_ORDSEQ_PREFLUSH:
- allowed_rq = &q->pre_flush_rq;
- break;
- case QUEUE_ORDSEQ_BAR:
- allowed_rq = &q->bar_rq;
- break;
- case QUEUE_ORDSEQ_POSTFLUSH:
- allowed_rq = &q->post_flush_rq;
- break;
- default:
- allowed_rq = NULL;
- break;
+ } else {
+ /* Ordered by draining. Wait for turn. */
+ WARN_ON(blk_ordered_req_seq(rq) < blk_ordered_cur_seq(q));
+ if (blk_ordered_req_seq(rq) > blk_ordered_cur_seq(q))
+ *rqp = NULL;
}
- if (rq != allowed_rq &&
- (blk_fs_request(rq) || rq == &q->pre_flush_rq ||
- rq == &q->post_flush_rq))
- *rqp = NULL;
-
return 1;
}
* Different hardware can have different requirements as to what pages
* it can do I/O directly to. A low level driver can call
* blk_queue_bounce_limit to have lower memory pages allocated as bounce
- * buffers for doing I/O to pages residing above @page. By default
- * the block layer sets this to the highest numbered "low" memory page.
+ * buffers for doing I/O to pages residing above @page.
**/
void blk_queue_bounce_limit(request_queue_t *q, u64 dma_addr)
{
unsigned long bounce_pfn = dma_addr >> PAGE_SHIFT;
-
- /*
- * set appropriate bounce gfp mask -- unfortunately we don't have a
- * full 4GB zone, so we have to resort to low memory for any bounces.
- * ISA has its own < 16MB zone.
- */
- if (bounce_pfn < blk_max_low_pfn) {
- BUG_ON(dma_addr < BLK_BOUNCE_ISA);
+ int dma = 0;
+
+ q->bounce_gfp = GFP_NOIO;
+#if BITS_PER_LONG == 64
+ /* Assume anything <= 4GB can be handled by IOMMU.
+ Actually some IOMMUs can handle everything, but I don't
+ know of a way to test this here. */
+ if (bounce_pfn < (min_t(u64,0xffffffff,BLK_BOUNCE_HIGH) >> PAGE_SHIFT))
+ dma = 1;
+ q->bounce_pfn = max_low_pfn;
+#else
+ if (bounce_pfn < blk_max_low_pfn)
+ dma = 1;
+ q->bounce_pfn = bounce_pfn;
+#endif
+ if (dma) {
init_emergency_isa_pool();
q->bounce_gfp = GFP_NOIO | GFP_DMA;
- } else
- q->bounce_gfp = GFP_NOIO;
-
- q->bounce_pfn = bounce_pfn;
+ q->bounce_pfn = bounce_pfn;
+ }
}
EXPORT_SYMBOL(blk_queue_bounce_limit);
t->max_hw_segments = min(t->max_hw_segments,b->max_hw_segments);
t->max_segment_size = min(t->max_segment_size,b->max_segment_size);
t->hardsect_size = max(t->hardsect_size,b->hardsect_size);
+ if (!test_bit(QUEUE_FLAG_CLUSTER, &b->queue_flags))
+ clear_bit(QUEUE_FLAG_CLUSTER, &t->queue_flags);
}
EXPORT_SYMBOL(blk_queue_stack_limits);
__FUNCTION__, depth);
}
- tag_index = kmalloc(depth * sizeof(struct request *), GFP_ATOMIC);
+ 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 = kmalloc(nr_ulongs * sizeof(unsigned long), GFP_ATOMIC);
+ tag_map = kzalloc(nr_ulongs * sizeof(unsigned long), GFP_ATOMIC);
if (!tag_map)
goto fail;
- memset(tag_index, 0, depth * sizeof(struct request *));
- memset(tag_map, 0, nr_ulongs * sizeof(unsigned long));
tags->real_max_depth = depth;
tags->max_depth = depth;
tags->tag_index = tag_index;
* don't plug a stopped queue, it must be paired with blk_start_queue()
* which will restart the queueing
*/
- if (test_bit(QUEUE_FLAG_STOPPED, &q->queue_flags))
+ if (blk_queue_stopped(q))
return;
- if (!test_and_set_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags))
+ if (!test_and_set_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags)) {
mod_timer(&q->unplug_timer, jiffies + q->unplug_delay);
+ blk_add_trace_generic(q, NULL, 0, BLK_TA_PLUG);
+ }
}
EXPORT_SYMBOL(blk_plug_device);
*/
void __generic_unplug_device(request_queue_t *q)
{
- if (unlikely(test_bit(QUEUE_FLAG_STOPPED, &q->queue_flags)))
+ if (unlikely(blk_queue_stopped(q)))
return;
if (!blk_remove_plug(q))
/*
* devices don't necessarily have an ->unplug_fn defined
*/
- if (q->unplug_fn)
+ 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);
+ }
}
static void blk_unplug_work(void *data)
{
request_queue_t *q = data;
+ blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_IO, NULL,
+ q->rq.count[READ] + q->rq.count[WRITE]);
+
q->unplug_fn(q);
}
{
request_queue_t *q = (request_queue_t *)data;
+ blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_TIMER, NULL,
+ q->rq.count[READ] + q->rq.count[WRITE]);
+
kblockd_schedule_work(&q->unplug_work);
}
**/
void blk_start_queue(request_queue_t *q)
{
+ WARN_ON(!irqs_disabled());
+
clear_bit(QUEUE_FLAG_STOPPED, &q->queue_flags);
/*
spin_lock_irqsave(q->queue_lock, flags);
blk_remove_plug(q);
- if (!elv_queue_empty(q))
- q->request_fn(q);
+
+ /*
+ * 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);
+ }
+ }
+
spin_unlock_irqrestore(q->queue_lock, flags);
}
EXPORT_SYMBOL(blk_run_queue);
/**
* blk_cleanup_queue: - release a &request_queue_t when it is no longer needed
- * @q: the request queue to be released
+ * @kobj: the kobj belonging of the request queue to be released
*
* Description:
* blk_cleanup_queue is the pair to blk_init_queue() or
* Hopefully the low level driver will have finished any
* outstanding requests first...
**/
-void blk_cleanup_queue(request_queue_t * q)
+static void blk_release_queue(struct kobject *kobj)
{
+ request_queue_t *q = container_of(kobj, struct request_queue, kobj);
struct request_list *rl = &q->rq;
- if (!atomic_dec_and_test(&q->refcnt))
- return;
-
- if (q->elevator)
- elevator_exit(q->elevator);
-
blk_sync_queue(q);
if (rl->rq_pool)
if (q->queue_tags)
__blk_queue_free_tags(q);
+ if (q->blk_trace)
+ blk_trace_shutdown(q);
+
kmem_cache_free(requestq_cachep, q);
}
+void blk_put_queue(request_queue_t *q)
+{
+ kobject_put(&q->kobj);
+}
+EXPORT_SYMBOL(blk_put_queue);
+
+void blk_cleanup_queue(request_queue_t * q)
+{
+ 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);
+}
+
EXPORT_SYMBOL(blk_cleanup_queue);
static int blk_init_free_list(request_queue_t *q)
}
EXPORT_SYMBOL(blk_alloc_queue);
+static struct kobj_type queue_ktype;
+
request_queue_t *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
{
request_queue_t *q;
memset(q, 0, sizeof(*q));
init_timer(&q->unplug_timer);
- atomic_set(&q->refcnt, 1);
+
+ snprintf(q->kobj.name, KOBJ_NAME_LEN, "%s", "queue");
+ q->kobj.ktype = &queue_ktype;
+ kobject_init(&q->kobj);
q->backing_dev_info.unplug_io_fn = blk_backing_dev_unplug;
q->backing_dev_info.unplug_io_data = q;
+ mutex_init(&q->sysfs_lock);
+
return q;
}
EXPORT_SYMBOL(blk_alloc_queue_node);
* get dealt with eventually.
*
* The queue spin lock must be held while manipulating the requests on the
- * request queue.
+ * request queue; this lock will be taken also from interrupt context, so irq
+ * disabling is needed for it.
*
* Function returns a pointer to the initialized request queue, or NULL if
* it didn't succeed.
return NULL;
q->node = node_id;
- if (blk_init_free_list(q))
- goto out_init;
+ if (blk_init_free_list(q)) {
+ kmem_cache_free(requestq_cachep, q);
+ return NULL;
+ }
/*
* if caller didn't supply a lock, they get per-queue locking with
return q;
}
- blk_cleanup_queue(q);
-out_init:
- kmem_cache_free(requestq_cachep, q);
+ blk_put_queue(q);
return NULL;
}
EXPORT_SYMBOL(blk_init_queue_node);
int blk_get_queue(request_queue_t *q)
{
if (likely(!test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) {
- atomic_inc(&q->refcnt);
+ kobject_get(&q->kobj);
return 0;
}
rq_init(q, rq);
rq->rl = rl;
+
+ blk_add_trace_generic(q, bio, rw, BLK_TA_GETRQ);
out:
return rq;
}
if (!rq) {
struct io_context *ioc;
+ blk_add_trace_generic(q, bio, rw, BLK_TA_SLEEPRQ);
+
__generic_unplug_device(q);
spin_unlock_irq(q->queue_lock);
io_schedule();
*/
void blk_requeue_request(request_queue_t *q, struct request *rq)
{
+ blk_add_trace_rq(q, rq, BLK_TA_REQUEUE);
+
if (blk_rq_tagged(rq))
blk_queue_end_tag(q, rq);
rq->rq_disk = bd_disk;
rq->flags |= REQ_NOMERGE;
rq->end_io = done;
- elv_add_request(q, rq, where, 1);
- generic_unplug_device(q);
+ WARN_ON(irqs_disabled());
+ spin_lock_irq(q->queue_lock);
+ __elv_add_request(q, rq, where, 1);
+ __generic_unplug_device(q);
+ spin_unlock_irq(q->queue_lock);
}
-
EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
/**
int blk_execute_rq(request_queue_t *q, struct gendisk *bd_disk,
struct request *rq, int at_head)
{
- DECLARE_COMPLETION(wait);
+ DECLARE_COMPLETION_ONSTACK(wait);
char sense[SCSI_SENSE_BUFFERSIZE];
int err = 0;
disk->stamp = now;
}
+EXPORT_SYMBOL_GPL(disk_round_stats);
+
/*
* queue lock must be held
*/
/**
* blk_end_sync_rq - executes a completion event on a request
* @rq: request to complete
+ * @error: end io status of the request
*/
void blk_end_sync_rq(struct request *rq, int error)
{
return 0;
/*
- * not contigious
+ * not contiguous
*/
if (req->sector + req->nr_sectors != next->sector)
return 0;
if (unlikely(bio_barrier(bio)))
req->flags |= (REQ_HARDBARRIER | REQ_NOMERGE);
+ if (bio_sync(bio))
+ req->flags |= REQ_RW_SYNC;
+
req->errors = 0;
req->hard_sector = req->sector = bio->bi_sector;
req->hard_nr_sectors = req->nr_sectors = bio_sectors(bio);
if (!q->back_merge_fn(q, req, bio))
break;
+ blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE);
+
req->biotail->bi_next = bio;
req->biotail = bio;
req->nr_sectors = req->hard_nr_sectors += nr_sectors;
if (!q->front_merge_fn(q, req, bio))
break;
+ blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE);
+
bio->bi_next = req->bio;
req->bio = bio;
request_queue_t *q;
sector_t maxsector;
int ret, nr_sectors = bio_sectors(bio);
+ dev_t old_dev;
might_sleep();
/* Test device or partition size, when known. */
* NOTE: we don't repeat the blk_size check for each new device.
* Stacking drivers are expected to know what they are doing.
*/
+ maxsector = -1;
+ old_dev = 0;
do {
char b[BDEVNAME_SIZE];
*/
blk_partition_remap(bio);
+ if (maxsector != -1)
+ blk_add_trace_remap(q, bio, old_dev, bio->bi_sector,
+ maxsector);
+
+ blk_add_trace_bio(q, bio, BLK_TA_QUEUE);
+
+ maxsector = bio->bi_sector;
+ old_dev = bio->bi_bdev->bd_dev;
+
ret = q->make_request_fn(q, bio);
} while (ret);
}
BIO_BUG_ON(!bio->bi_io_vec);
bio->bi_rw |= rw;
if (rw & WRITE)
- mod_page_state(pgpgout, count);
+ count_vm_events(PGPGOUT, count);
else
- mod_page_state(pgpgin, count);
+ count_vm_events(PGPGIN, count);
if (unlikely(block_dump)) {
char b[BDEVNAME_SIZE];
int total_bytes, bio_nbytes, error, next_idx = 0;
struct bio *bio;
+ blk_add_trace_rq(req->q, req, BLK_TA_COMPLETE);
+
/*
* extend uptodate bool to allow < 0 value to be direct io error
*/
*/
static void blk_done_softirq(struct softirq_action *h)
{
- struct list_head *cpu_list;
- LIST_HEAD(local_list);
+ struct list_head *cpu_list, local_list;
local_irq_disable();
cpu_list = &__get_cpu_var(blk_cpu_done);
- list_splice_init(cpu_list, &local_list);
+ list_replace_init(cpu_list, &local_list);
local_irq_enable();
while (!list_empty(&local_list)) {
*
* Description:
* Ends all I/O on a request. It does not handle partial completions,
- * unless the driver actually implements this in its completionc callback
+ * unless the driver actually implements this in its completion callback
* through requeueing. Theh actual completion happens out-of-order,
* through a softirq handler. The user must have registered a completion
* callback through blk_queue_softirq_done().
if (unlikely(laptop_mode) && blk_fs_request(req))
laptop_io_completion();
- if (disk && blk_fs_request(req)) {
+ /*
+ * 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) {
unsigned long duration = jiffies - req->start_time;
const int rw = rq_data_dir(req);
void blk_rq_bio_prep(request_queue_t *q, struct request *rq, struct bio *bio)
{
- /* first three bits are identical in rq->flags and bio->bi_rw */
- rq->flags |= (bio->bi_rw & 7);
+ /* first two bits are identical in rq->flags and bio->bi_rw */
+ rq->flags |= (bio->bi_rw & 3);
rq->nr_phys_segments = bio_phys_segments(q, bio);
rq->nr_hw_segments = bio_hw_segments(q, bio);
iocontext_cachep = kmem_cache_create("blkdev_ioc",
sizeof(struct io_context), 0, SLAB_PANIC, NULL, NULL);
- for (i = 0; i < NR_CPUS; i++)
+ for_each_possible_cpu(i)
INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i));
open_softirq(BLOCK_SOFTIRQ, blk_done_softirq, NULL);
-#ifdef CONFIG_HOTPLUG_CPU
- register_cpu_notifier(&blk_cpu_notifier);
-#endif
+ register_hotcpu_notifier(&blk_cpu_notifier);
blk_max_low_pfn = max_low_pfn;
blk_max_pfn = max_pfn;
BUG_ON(atomic_read(&ioc->refcount) == 0);
if (atomic_dec_and_test(&ioc->refcount)) {
+ struct cfq_io_context *cic;
+
+ rcu_read_lock();
if (ioc->aic && ioc->aic->dtor)
ioc->aic->dtor(ioc->aic);
- if (ioc->cic && ioc->cic->dtor)
- ioc->cic->dtor(ioc->cic);
+ if (ioc->cic_root.rb_node != NULL) {
+ struct rb_node *n = rb_first(&ioc->cic_root);
+
+ cic = rb_entry(n, struct cfq_io_context, rb_node);
+ cic->dtor(ioc);
+ }
+ rcu_read_unlock();
kmem_cache_free(iocontext_cachep, ioc);
}
{
unsigned long flags;
struct io_context *ioc;
+ struct cfq_io_context *cic;
local_irq_save(flags);
task_lock(current);
if (ioc->aic && ioc->aic->exit)
ioc->aic->exit(ioc->aic);
- if (ioc->cic && ioc->cic->exit)
- ioc->cic->exit(ioc->cic);
-
+ if (ioc->cic_root.rb_node != NULL) {
+ cic = rb_entry(rb_first(&ioc->cic_root), struct cfq_io_context, rb_node);
+ cic->exit(ioc);
+ }
+
put_io_context(ioc);
}
ret->last_waited = jiffies; /* doesn't matter... */
ret->nr_batch_requests = 0; /* because this is 0 */
ret->aic = NULL;
- ret->cic = NULL;
+ ret->cic_root.rb_node = NULL;
+ /* make sure set_task_ioprio() sees the settings above */
+ smp_wmb();
tsk->io_context = ret;
}
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;
- int ret = queue_var_store(&q->nr_requests, page, count);
- if (q->nr_requests < BLKDEV_MIN_RQ)
- q->nr_requests = 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_clear_queue_full(q, WRITE);
wake_up(&rl->wait[WRITE]);
}
+ spin_unlock_irq(q->queue_lock);
return ret;
}
queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
{
struct queue_sysfs_entry *entry = to_queue(attr);
- struct request_queue *q;
+ request_queue_t *q = container_of(kobj, struct request_queue, kobj);
+ ssize_t res;
- q = container_of(kobj, struct request_queue, kobj);
if (!entry->show)
return -EIO;
-
- return entry->show(q, page);
+ 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
const char *page, size_t length)
{
struct queue_sysfs_entry *entry = to_queue(attr);
- struct request_queue *q;
+ request_queue_t *q = container_of(kobj, struct request_queue, kobj);
+
+ ssize_t res;
- q = container_of(kobj, struct request_queue, kobj);
if (!entry->store)
return -EIO;
-
- return entry->store(q, page, length);
+ 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 = {
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)
return -ENXIO;
q->kobj.parent = kobject_get(&disk->kobj);
- if (!q->kobj.parent)
- return -EBUSY;
-
- snprintf(q->kobj.name, KOBJ_NAME_LEN, "%s", "queue");
- q->kobj.ktype = &queue_ktype;
- ret = kobject_register(&q->kobj);
+ ret = kobject_add(&q->kobj);
if (ret < 0)
return ret;
+ kobject_uevent(&q->kobj, KOBJ_ADD);
+
ret = elv_register_queue(q);
if (ret) {
- kobject_unregister(&q->kobj);
+ kobject_uevent(&q->kobj, KOBJ_REMOVE);
+ kobject_del(&q->kobj);
return ret;
}
if (q && q->request_fn) {
elv_unregister_queue(q);
- kobject_unregister(&q->kobj);
+ kobject_uevent(&q->kobj, KOBJ_REMOVE);
+ kobject_del(&q->kobj);
kobject_put(&disk->kobj);
}
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff