Btrfs: take overflow into account in reserving space

My overcommit stuff can be a little racy when we're filling up the disk with
fs_mark and we overcommit into things that quickly get used up for data.  So use
num_bytes to see if we have enough available space so we're less likely to
overcommit ourselves out of the ability to make reservations.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index f9711a82fc541143ddc88301e126963cd6987ae0..f95e55083bdb5fcd3fe8ce233ce08fef9bb1febd 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3521,7 +3521,7 @@ again:
                        avail >>= 1;
                 spin_unlock(&root->fs_info->free_chunk_lock);
 
-               if (used + orig_bytes < space_info->total_bytes + avail) {
+               if (used + num_bytes < space_info->total_bytes + avail) {
                        space_info->bytes_may_use += orig_bytes;
                        ret = 0;
                }