Btrfs: Reorder tests in set_extent_bit to properly find holes

Yan Zheng noticed that set_extent_bit was exiting too early when there
was a hole in the map.  The fix is to reorder the tests to check for the
hole first.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 22 insertions, 22 deletions

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 33f7a18dddf7..370ed97e52f5 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -714,28 +714,6 @@ again:
         }
         /*
          * | ---- desired range ---- |
-         *                        | state |
-         * We need to split the extent, and set the bit
-         * on the first half
-         */
-        if (state->start <= end && state->end > end) {
-                set = state->state & bits;
-                if (exclusive && set) {
-                        *failed_start = start;
-                        err = -EEXIST;
-                        goto out;
-                }
-                err = split_state(tree, state, prealloc, end + 1);
-                BUG_ON(err == -EEXIST);
-
-                prealloc->state |= bits;
-                merge_state(tree, prealloc);
-                prealloc = NULL;
-                goto out;
-        }
-
-        /*
-         * | ---- desired range ---- |
          *     | state | or               | state |
          *
          * There's a hole, we need to insert something in it and
@@ -756,6 +734,28 @@ again:
                 start = this_end + 1;
                 goto search_again;
         }
+        /*
+         * | ---- desired range ---- |
+         *                        | state |
+         * We need to split the extent, and set the bit
+         * on the first half
+         */
+        if (state->start <= end && state->end > end) {
+                set = state->state & bits;
+                if (exclusive && set) {
+                        *failed_start = start;
+                        err = -EEXIST;
+                        goto out;
+                }
+                err = split_state(tree, state, prealloc, end + 1);
+                BUG_ON(err == -EEXIST);
+
+                prealloc->state |= bits;
+                merge_state(tree, prealloc);
+                prealloc = NULL;
+                goto out;
+        }
+
         goto search_again;
 
 out: