loop: use BIO list management functions

Now that the bio list management stuff is generic, convert loop to use
bio lists instead of its own private bio list implementation.

Cc:  Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 7 insertions, 19 deletions

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index ddae80825899..9ca4bb014657 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -511,11 +511,7 @@ out:
  */
 static void loop_add_bio(struct loop_device *lo, struct bio *bio)
 {
-        if (lo->lo_biotail) {
-                lo->lo_biotail->bi_next = bio;
-                lo->lo_biotail = bio;
-        } else
-                lo->lo_bio = lo->lo_biotail = bio;
+        bio_list_add(&lo->lo_bio_list, bio);
 }
 
 /*
@@ -523,16 +519,7 @@ static void loop_add_bio(struct loop_device *lo, struct bio *bio)
  */
 static struct bio *loop_get_bio(struct loop_device *lo)
 {
-        struct bio *bio;
-
-        if ((bio = lo->lo_bio)) {
-                if (bio == lo->lo_biotail)
-                        lo->lo_biotail = NULL;
-                lo->lo_bio = bio->bi_next;
-                bio->bi_next = NULL;
-        }
-
-        return bio;
+        return bio_list_pop(&lo->lo_bio_list);
 }
 
 static int loop_make_request(struct request_queue *q, struct bio *old_bio)
@@ -609,12 +596,13 @@ static int loop_thread(void *data)
 
         set_user_nice(current, -20);
 
-        while (!kthread_should_stop() || lo->lo_bio) {
+        while (!kthread_should_stop() || !bio_list_empty(&lo->lo_bio_list)) {
 
                 wait_event_interruptible(lo->lo_event,
-                                lo->lo_bio || kthread_should_stop());
+                                !bio_list_empty(&lo->lo_bio_list) ||
+                                kthread_should_stop());
 
-                if (!lo->lo_bio)
+                if (bio_list_empty(&lo->lo_bio_list))
                         continue;
                 spin_lock_irq(&lo->lo_lock);
                 bio = loop_get_bio(lo);
@@ -841,7 +829,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
         lo->old_gfp_mask = mapping_gfp_mask(mapping);
         mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS));
 
-        lo->lo_bio = lo->lo_biotail = NULL;
+        bio_list_init(&lo->lo_bio_list);
 
         /*
          * set queue make_request_fn, and add limits based on lower level