/*
* 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>
/* 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 < (0xffffffff>>PAGE_SHIFT))
+ if (bounce_pfn < (min_t(u64,0xffffffff,BLK_BOUNCE_HIGH) >> PAGE_SHIFT))
dma = 1;
q->bounce_pfn = max_low_pfn;
#else
**/
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);
* 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.
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;
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);
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];
*/
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);
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;