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path: root/drivers/block/loop.c
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Diffstat (limited to 'drivers/block/loop.c')
-rw-r--r--drivers/block/loop.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 54046e51160a..ae1251270624 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -463,6 +463,7 @@ out:
*/
static void loop_add_bio(struct loop_device *lo, struct bio *bio)
{
+ lo->lo_bio_count++;
bio_list_add(&lo->lo_bio_list, bio);
}
@@ -471,6 +472,7 @@ static void loop_add_bio(struct loop_device *lo, struct bio *bio)
*/
static struct bio *loop_get_bio(struct loop_device *lo)
{
+ lo->lo_bio_count--;
return bio_list_pop(&lo->lo_bio_list);
}
@@ -489,6 +491,10 @@ static void loop_make_request(struct request_queue *q, struct bio *old_bio)
goto out;
if (unlikely(rw == WRITE && (lo->lo_flags & LO_FLAGS_READ_ONLY)))
goto out;
+ if (lo->lo_bio_count >= q->nr_congestion_on)
+ wait_event_lock_irq(lo->lo_req_wait,
+ lo->lo_bio_count < q->nr_congestion_off,
+ lo->lo_lock);
loop_add_bio(lo, old_bio);
wake_up(&lo->lo_event);
spin_unlock_irq(&lo->lo_lock);
@@ -546,6 +552,8 @@ static int loop_thread(void *data)
continue;
spin_lock_irq(&lo->lo_lock);
bio = loop_get_bio(lo);
+ if (lo->lo_bio_count < lo->lo_queue->nr_congestion_off)
+ wake_up(&lo->lo_req_wait);
spin_unlock_irq(&lo->lo_lock);
BUG_ON(!bio);
@@ -873,6 +881,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
lo->transfer = transfer_none;
lo->ioctl = NULL;
lo->lo_sizelimit = 0;
+ lo->lo_bio_count = 0;
lo->old_gfp_mask = mapping_gfp_mask(mapping);
mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS));
@@ -1673,6 +1682,7 @@ static int loop_add(struct loop_device **l, int i)
lo->lo_number = i;
lo->lo_thread = NULL;
init_waitqueue_head(&lo->lo_event);
+ init_waitqueue_head(&lo->lo_req_wait);
spin_lock_init(&lo->lo_lock);
disk->major = LOOP_MAJOR;
disk->first_minor = i << part_shift;