NOMMU: Fix MAP_PRIVATE mmap() of objects where the data can be mapped directly

[linux-block.git] / block / blk-barrier.c

diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index 30022b4e2f6306b36d6c878efc0ea4abb28e5082..6593ab39cfe9223b106d3b5a897937e58176e6b1 100644 (file)
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -348,6 +348,9 @@ static void blkdev_discard_end_io(struct bio *bio, int err)
                clear_bit(BIO_UPTODATE, &bio->bi_flags);
        }
 
+       if (bio->bi_private)
+               complete(bio->bi_private);
+
        bio_put(bio);
 }
 
@@ -357,21 +360,20 @@ static void blkdev_discard_end_io(struct bio *bio, int err)
  * @sector:    start sector
  * @nr_sects:  number of sectors to discard
  * @gfp_mask:  memory allocation flags (for bio_alloc)
+ * @flags:     DISCARD_FL_* flags to control behaviour
  *
  * Description:
- *    Issue a discard request for the sectors in question. Does not wait.
+ *    Issue a discard request for the sectors in question.
  */
-int blkdev_issue_discard(struct block_device *bdev,
-                        sector_t sector, sector_t nr_sects, gfp_t gfp_mask)
+int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
+               sector_t nr_sects, gfp_t gfp_mask, int flags)
 {
-       struct request_queue *q;
-       struct bio *bio;
+       DECLARE_COMPLETION_ONSTACK(wait);
+       struct request_queue *q = bdev_get_queue(bdev);
+       int type = flags & DISCARD_FL_BARRIER ?
+               DISCARD_BARRIER : DISCARD_NOBARRIER;
        int ret = 0;
 
-       if (bdev->bd_disk == NULL)
-               return -ENXIO;
-
-       q = bdev_get_queue(bdev);
        if (!q)
                return -ENXIO;
 
@@ -379,12 +381,14 @@ int blkdev_issue_discard(struct block_device *bdev,
                return -EOPNOTSUPP;
 
        while (nr_sects && !ret) {
-               bio = bio_alloc(gfp_mask, 0);
+               struct bio *bio = bio_alloc(gfp_mask, 0);
                if (!bio)
                        return -ENOMEM;
 
                bio->bi_end_io = blkdev_discard_end_io;
                bio->bi_bdev = bdev;
+               if (flags & DISCARD_FL_WAIT)
+                       bio->bi_private = &wait;
 
                bio->bi_sector = sector;
 
@@ -396,10 +400,13 @@ int blkdev_issue_discard(struct block_device *bdev,
                        bio->bi_size = nr_sects << 9;
                        nr_sects = 0;
                }
+
                bio_get(bio);
-               submit_bio(DISCARD_BARRIER, bio);
+               submit_bio(type, bio);
+
+               if (flags & DISCARD_FL_WAIT)
+                       wait_for_completion(&wait);
 
-               /* Check if it failed immediately */
                if (bio_flagged(bio, BIO_EOPNOTSUPP))
                        ret = -EOPNOTSUPP;
                else if (!bio_flagged(bio, BIO_UPTODATE))