Btrfs: don't commit instead of overcommitting
Josef Bacik [Fri, 28 Sep 2012 20:04:19 +0000 (16:04 -0400)]
I don't think we have the same problem that this was supposed to fix
originally since we can allocate chunks in the enospc path now.  This code
is causing us to constantly commit the transaction as we get close to using
all of our available space in our currently allocated chunks, instead of
allocating another chunk and carrying on with life, which is not nice for
performance.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>

fs/btrfs/extent-tree.c

index ca4aad9..3d3e2c1 100644 (file)
@@ -3907,7 +3907,6 @@ static int reserve_metadata_bytes(struct btrfs_root *root,
        int flush_state = FLUSH_DELAYED_ITEMS_NR;
        int ret = 0;
        bool flushing = false;
-       bool committed = false;
 
 again:
        ret = 0;
@@ -3970,33 +3969,12 @@ again:
                        (orig_bytes * 2);
        }
 
-       if (ret) {
-               u64 avail;
-
-               /*
-                * If we have a lot of space that's pinned, don't bother doing
-                * the overcommit dance yet and just commit the transaction.
-                */
-               avail = (space_info->total_bytes - space_info->bytes_used) * 8;
-               do_div(avail, 10);
-               if (space_info->bytes_pinned >= avail && flush && !committed) {
-                       space_info->flush = 1;
-                       flushing = true;
-                       spin_unlock(&space_info->lock);
-                       ret = may_commit_transaction(root, space_info,
-                                                    orig_bytes, 1);
-                       if (ret)
-                               goto out;
-                       committed = true;
-                       goto again;
-               }
-
-               if (can_overcommit(root, space_info, orig_bytes, flush)) {
-                       space_info->bytes_may_use += orig_bytes;
-                       trace_btrfs_space_reservation(root->fs_info,
-                               "space_info", space_info->flags, orig_bytes, 1);
-                       ret = 0;
-               }
+       if (ret && can_overcommit(root, space_info, orig_bytes, flush)) {
+               space_info->bytes_may_use += orig_bytes;
+               trace_btrfs_space_reservation(root->fs_info, "space_info",
+                                             space_info->flags, orig_bytes,
+                                             1);
+               ret = 0;
        }
 
        /*