Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs...

[linux-drm-fsl-dcu.git] / fs / btrfs / extent-tree.c

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index d0c4d584efadd9cf92050bf0da946e364da2dc8a..e238a0cdac677c06b1774018bf549b03399da4c8 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1568,23 +1568,23 @@ static int remove_extent_backref(struct btrfs_trans_handle *trans,
        return ret;
 }
 
-#ifdef BIO_RW_DISCARD
 static void btrfs_issue_discard(struct block_device *bdev,
                                u64 start, u64 len)
 {
        blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL,
                             DISCARD_FL_BARRIER);
 }
-#endif
 
 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
                                u64 num_bytes)
 {
-#ifdef BIO_RW_DISCARD
        int ret;
        u64 map_length = num_bytes;
        struct btrfs_multi_bio *multi = NULL;
 
+       if (!btrfs_test_opt(root, DISCARD))
+               return 0;
+
        /* Tell the block device(s) that the sectors can be discarded */
        ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
                              bytenr, &map_length, &multi, 0);
@@ -1604,9 +1604,6 @@ static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
        }
 
        return ret;
-#else
-       return 0;
-#endif
 }
 
 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
@@ -3690,6 +3687,14 @@ static int pin_down_bytes(struct btrfs_trans_handle *trans,
        if (is_data)
                goto pinit;
 
+       /*
+        * discard is sloooow, and so triggering discards on
+        * individual btree blocks isn't a good plan.  Just
+        * pin everything in discard mode.
+        */
+       if (btrfs_test_opt(root, DISCARD))
+               goto pinit;
+
        buf = btrfs_find_tree_block(root, bytenr, num_bytes);
        if (!buf)
                goto pinit;