#include <linux/swap.h>
#include <linux/writeback.h>
#include <linux/task_io_accounting_ops.h>
-#include <linux/interrupt.h>
-#include <linux/cpu.h>
#include <linux/blktrace_api.h>
#include <linux/fault-inject.h>
*/
static struct workqueue_struct *kblockd_workqueue;
-static DEFINE_PER_CPU(struct list_head, blk_cpu_done);
-
static void drive_stat_acct(struct request *rq, int new_io)
{
struct hd_struct *part;
int rw = rq_data_dir(rq);
+ int cpu;
if (!blk_fs_request(rq) || !rq->rq_disk)
return;
- part = get_part(rq->rq_disk, rq->sector);
+ cpu = part_stat_lock();
+ part = disk_map_sector_rcu(rq->rq_disk, rq->sector);
+
if (!new_io)
- __all_stat_inc(rq->rq_disk, part, merges[rw], rq->sector);
+ part_stat_inc(cpu, part, merges[rw]);
else {
- disk_round_stats(rq->rq_disk);
- rq->rq_disk->in_flight++;
- if (part) {
- part_round_stats(part);
- part->in_flight++;
- }
+ part_round_stats(cpu, part);
+ part_inc_in_flight(part);
}
+
+ part_stat_unlock();
}
void blk_queue_congestion_threshold(struct request_queue *q)
memset(rq, 0, sizeof(*rq));
INIT_LIST_HEAD(&rq->queuelist);
- INIT_LIST_HEAD(&rq->donelist);
+ rq->cpu = -1;
rq->q = q;
rq->sector = rq->hard_sector = (sector_t) -1;
INIT_HLIST_NODE(&rq->hash);
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);
+ kblockd_schedule_work(q, &q->unplug_work);
}
void blk_unplug(struct request_queue *q)
}
EXPORT_SYMBOL(blk_unplug);
+static void blk_invoke_request_fn(struct request_queue *q)
+{
+ /*
+ * one level of recursion is ok and is much faster than kicking
+ * the unplug handling
+ */
+ if (!queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) {
+ q->request_fn(q);
+ queue_flag_clear(QUEUE_FLAG_REENTER, q);
+ } else {
+ queue_flag_set(QUEUE_FLAG_PLUGGED, q);
+ kblockd_schedule_work(q, &q->unplug_work);
+ }
+}
+
/**
* blk_start_queue - restart a previously stopped queue
* @q: The &struct request_queue in question
WARN_ON(!irqs_disabled());
queue_flag_clear(QUEUE_FLAG_STOPPED, q);
-
- /*
- * one level of recursion is ok and is much faster than kicking
- * the unplug handling
- */
- if (!queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) {
- q->request_fn(q);
- queue_flag_clear(QUEUE_FLAG_REENTER, q);
- } else {
- blk_plug_device(q);
- kblockd_schedule_work(&q->unplug_work);
- }
+ blk_invoke_request_fn(q);
}
EXPORT_SYMBOL(blk_start_queue);
* 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 (!queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) {
- q->request_fn(q);
- queue_flag_clear(QUEUE_FLAG_REENTER, q);
- } else {
- blk_plug_device(q);
- kblockd_schedule_work(&q->unplug_work);
- }
- }
+ if (!elv_queue_empty(q))
+ blk_invoke_request_fn(q);
}
EXPORT_SYMBOL(__blk_run_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
+ * Function returns a pointer to the initialized request queue, or %NULL if
* it didn't succeed.
*
* Note:
blk_rq_init(q, rq);
- /*
- * first three bits are identical in rq->cmd_flags and bio->bi_rw,
- * see bio.h and blkdev.h
- */
rq->cmd_flags = rw | REQ_ALLOCED;
if (priv) {
EXPORT_SYMBOL(blk_requeue_request);
/**
- * blk_insert_request - insert a special request in to a request queue
+ * blk_insert_request - insert a special request into 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
* 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.
+ * REQ_TYPE_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
__elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0);
}
-/*
- * disk_round_stats() - Round off the performance stats on a struct
+static void part_round_stats_single(int cpu, struct hd_struct *part,
+ unsigned long now)
+{
+ if (now == part->stamp)
+ return;
+
+ if (part->in_flight) {
+ __part_stat_add(cpu, part, time_in_queue,
+ part->in_flight * (now - part->stamp));
+ __part_stat_add(cpu, part, io_ticks, (now - part->stamp));
+ }
+ part->stamp = now;
+}
+
+/**
+ * part_round_stats() - Round off the performance stats on a struct
* disk_stats.
*
* The average IO queue length and utilisation statistics are maintained
* /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)
+void part_round_stats(int cpu, struct hd_struct *part)
{
unsigned long now = jiffies;
- if (now == disk->stamp)
- return;
-
- 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));
- }
- disk->stamp = now;
-}
-EXPORT_SYMBOL_GPL(disk_round_stats);
-
-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;
+ if (part->partno)
+ part_round_stats_single(cpu, &part_to_disk(part)->part0, now);
+ part_round_stats_single(cpu, part, now);
}
+EXPORT_SYMBOL_GPL(part_round_stats);
/*
* queue lock must be held
void init_request_from_bio(struct request *req, struct bio *bio)
{
+ req->cpu = bio->bi_comp_cpu;
req->cmd_type = REQ_TYPE_FS;
/*
/*
* REQ_BARRIER implies no merging, but lets make it explicit
*/
- if (unlikely(bio_barrier(bio)))
+ if (unlikely(bio_discard(bio))) {
+ req->cmd_flags |= REQ_DISCARD;
+ if (bio_barrier(bio))
+ req->cmd_flags |= REQ_SOFTBARRIER;
+ req->q->prepare_discard_fn(req->q, req);
+ } else if (unlikely(bio_barrier(bio)))
req->cmd_flags |= (REQ_HARDBARRIER | REQ_NOMERGE);
if (bio_sync(bio))
static int __make_request(struct request_queue *q, struct bio *bio)
{
struct request *req;
- int el_ret, nr_sectors, barrier, err;
+ int el_ret, nr_sectors, barrier, discard, err;
const unsigned short prio = bio_prio(bio);
const int sync = bio_sync(bio);
int rw_flags;
blk_queue_bounce(q, &bio);
barrier = bio_barrier(bio);
- if (unlikely(barrier) && (q->next_ordered == QUEUE_ORDERED_NONE)) {
+ if (unlikely(barrier) && bio_has_data(bio) &&
+ (q->next_ordered == QUEUE_ORDERED_NONE)) {
+ err = -EOPNOTSUPP;
+ goto end_io;
+ }
+
+ discard = bio_discard(bio);
+ if (unlikely(discard) && !q->prepare_discard_fn) {
err = -EOPNOTSUPP;
goto end_io;
}
init_request_from_bio(req, bio);
spin_lock_irq(q->queue_lock);
+ if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags) ||
+ bio_flagged(bio, BIO_CPU_AFFINE))
+ req->cpu = blk_cpu_to_group(smp_processor_id());
if (elv_queue_empty(q))
blk_plug_device(q);
add_request(q, req);
out:
if (sync)
__generic_unplug_device(q);
-
spin_unlock_irq(q->queue_lock);
return 0;
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))
+ struct hd_struct *part = bio->bi_bdev->bd_part;
+
+ if (part_to_disk(part)->part0.make_it_fail || part->make_it_fail)
return should_fail(&fail_make_request, bio->bi_size);
return 0;
}
/**
- * generic_make_request: hand a buffer to its device driver for I/O
+ * 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
if (bio_check_eod(bio, nr_sectors))
goto end_io;
- if (bio_empty_barrier(bio) && !q->prepare_flush_fn) {
+ if ((bio_empty_barrier(bio) && !q->prepare_flush_fn) ||
+ (bio_discard(bio) && !q->prepare_discard_fn)) {
err = -EOPNOTSUPP;
goto end_io;
}
EXPORT_SYMBOL(generic_make_request);
/**
- * submit_bio: submit a bio to the block device layer for I/O
+ * 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.
+ * interfaces; @bio must be presetup and ready for I/O.
*
*/
void submit_bio(int rw, struct bio *bio)
* 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 (bio_has_data(bio)) {
if (rw & WRITE) {
count_vm_events(PGPGOUT, count);
} else {
/**
* __end_that_request_first - end I/O on a request
* @req: the request being processed
- * @error: 0 for success, < 0 for error
+ * @error: %0 for success, < %0 for error
* @nr_bytes: number of bytes to complete
*
* Description:
* 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
+ * %0 - we are done with this request, call end_that_request_last()
+ * %1 - still buffers pending for this request
**/
static int __end_that_request_first(struct request *req, int error,
int nr_bytes)
blk_add_trace_rq(req->q, req, BLK_TA_COMPLETE);
/*
- * for a REQ_BLOCK_PC request, we want to carry any eventual
+ * for a REQ_TYPE_BLOCK_PC request, we want to carry any eventual
* sense key with us all the way through
*/
if (!blk_pc_request(req))
}
if (blk_fs_request(req) && req->rq_disk) {
- struct hd_struct *part = get_part(req->rq_disk, req->sector);
const int rw = rq_data_dir(req);
+ struct hd_struct *part;
+ int cpu;
- all_stat_add(req->rq_disk, part, sectors[rw],
- nr_bytes >> 9, req->sector);
+ cpu = part_stat_lock();
+ part = disk_map_sector_rcu(req->rq_disk, req->sector);
+ part_stat_add(cpu, part, sectors[rw], nr_bytes >> 9);
+ part_stat_unlock();
}
total_bytes = bio_nbytes = 0;
return 1;
}
-/*
- * 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)
-{
- struct list_head *cpu_list, local_list;
-
- local_irq_disable();
- cpu_list = &__get_cpu_var(blk_cpu_done);
- list_replace_init(cpu_list, &local_list);
- local_irq_enable();
-
- while (!list_empty(&local_list)) {
- struct request *rq;
-
- rq = list_entry(local_list.next, struct request, donelist);
- list_del_init(&rq->donelist);
- rq->q->softirq_done_fn(rq);
- }
-}
-
-static int __cpuinit blk_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu)
-{
- /*
- * If a CPU goes away, splice its entries to the current CPU
- * and trigger a run of the softirq
- */
- if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
- 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;
-}
-
-
-static struct notifier_block blk_cpu_notifier __cpuinitdata = {
- .notifier_call = blk_cpu_notify,
-};
-
-/**
- * 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,
- * unless the driver actually implements this in its completion callback
- * through requeueing. The actual completion happens out-of-order,
- * 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);
-
- 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);
-}
-EXPORT_SYMBOL(blk_complete_request);
-
/*
* queue lock must be held
*/
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);
- struct hd_struct *part = get_part(disk, req->sector);
-
- __all_stat_inc(disk, part, ios[rw], req->sector);
- __all_stat_add(disk, part, ticks[rw], duration, req->sector);
- disk_round_stats(disk);
- disk->in_flight--;
- if (part) {
- part_round_stats(part);
- part->in_flight--;
- }
+ struct hd_struct *part;
+ int cpu;
+
+ cpu = part_stat_lock();
+ part = disk_map_sector_rcu(disk, req->sector);
+
+ part_stat_inc(cpu, part, ios[rw]);
+ part_stat_add(cpu, part, ticks[rw], duration);
+ part_round_stats(cpu, part);
+ part_dec_in_flight(part);
+
+ part_stat_unlock();
}
if (req->end_io)
/**
* end_queued_request - end all I/O on a queued request
* @rq: the request being processed
- * @uptodate: error value or 0/1 uptodate flag
+ * @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
+ * Not suitable for normal I/O completion, unless the driver still has
* the request attached to the block layer.
*
**/
/**
* end_dequeued_request - end all I/O on a dequeued request
* @rq: the request being processed
- * @uptodate: error value or 0/1 uptodate flag
+ * @uptodate: error value or %0/%1 uptodate flag
*
* Description:
* Ends all I/O on a request. The request must already have been
/**
* end_request - end I/O on the current segment of the request
* @req: the request being processed
- * @uptodate: error value or 0/1 uptodate flag
+ * @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
+ * This is a remnant of how older block drivers handled I/O completions.
+ * Modern drivers typically end I/O 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
/**
* blk_end_io - Generic end_io function to complete a request.
* @rq: the request being processed
- * @error: 0 for success, < 0 for error
+ * @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
* @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
+ * If the callback returns non %0, this helper returns without
* completion of the request.
*
* Description:
* If @rq has leftover, sets it up for the next range of segments.
*
* Return:
- * 0 - we are done with this request
- * 1 - this request is not freed yet, it still has pending buffers.
+ * %0 - we are done with this request
+ * %1 - this request is not freed yet, it still has pending buffers.
**/
static int blk_end_io(struct request *rq, int error, unsigned int nr_bytes,
unsigned int bidi_bytes,
struct request_queue *q = rq->q;
unsigned long flags = 0UL;
- if (blk_fs_request(rq) || blk_pc_request(rq)) {
+ if (bio_has_data(rq->bio) || blk_discard_rq(rq)) {
if (__end_that_request_first(rq, error, nr_bytes))
return 1;
/**
* blk_end_request - Helper function for drivers to complete the request.
* @rq: the request being processed
- * @error: 0 for success, < 0 for error
+ * @error: %0 for success, < %0 for error
* @nr_bytes: number of bytes to complete
*
* Description:
* 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
+ * %0 - we are done with this request
+ * %1 - still buffers pending for this request
**/
int blk_end_request(struct request *rq, int error, unsigned int nr_bytes)
{
/**
* __blk_end_request - Helper function for drivers to complete the request.
* @rq: the request being processed
- * @error: 0 for success, < 0 for error
+ * @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
+ * %0 - we are done with this request
+ * %1 - still buffers pending for this request
**/
int __blk_end_request(struct request *rq, int error, unsigned int nr_bytes)
{
- if (blk_fs_request(rq) || blk_pc_request(rq)) {
- if (__end_that_request_first(rq, error, nr_bytes))
- return 1;
- }
+ if ((bio_has_data(rq->bio) || blk_discard_rq(rq)) &&
+ __end_that_request_first(rq, error, nr_bytes))
+ return 1;
add_disk_randomness(rq->rq_disk);
/**
* 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
+ * @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
*
* 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
+ * %0 - we are done with this request
+ * %1 - still buffers pending for this request
**/
int blk_end_bidi_request(struct request *rq, int error, unsigned int nr_bytes,
unsigned int bidi_bytes)
/**
* blk_end_request_callback - Special helper function for tricky drivers
* @rq: the request being processed
- * @error: 0 for success, < 0 for error
+ * @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
+ * If the callback returns non %0, this helper returns without
* completion of the request.
*
* Description:
* 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.
+ * %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.
**/
int blk_end_request_callback(struct request *rq, int error,
unsigned int nr_bytes,
void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
struct bio *bio)
{
- /* first two bits are identical in rq->cmd_flags and bio->bi_rw */
+ /* Bit 0 (R/W) is identical in rq->cmd_flags and bio->bi_rw, and
+ we want BIO_RW_AHEAD (bit 1) to imply REQ_FAILFAST (bit 1). */
rq->cmd_flags |= (bio->bi_rw & 3);
- rq->nr_phys_segments = bio_phys_segments(q, bio);
- rq->nr_hw_segments = bio_hw_segments(q, bio);
+ if (bio_has_data(bio)) {
+ rq->nr_phys_segments = bio_phys_segments(q, bio);
+ rq->buffer = bio_data(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);
rq->data_len = bio->bi_size;
rq->bio = rq->biotail = bio;
rq->rq_disk = bio->bi_bdev->bd_disk;
}
-int kblockd_schedule_work(struct work_struct *work)
+int kblockd_schedule_work(struct request_queue *q, struct work_struct *work)
{
return queue_work(kblockd_workqueue, work);
}
int __init blk_dev_init(void)
{
- int i;
-
kblockd_workqueue = create_workqueue("kblockd");
if (!kblockd_workqueue)
panic("Failed to create kblockd\n");
blk_requestq_cachep = kmem_cache_create("blkdev_queue",
sizeof(struct request_queue), 0, SLAB_PANIC, NULL);
- for_each_possible_cpu(i)
- INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i));
-
- open_softirq(BLOCK_SOFTIRQ, blk_done_softirq);
- register_hotcpu_notifier(&blk_cpu_notifier);
-
return 0;
}
projects / linux-2.6-omap-h63xx.git / blobdiff