btrfs: Don't BUG_ON alloc_path errors in find_next_chunk

I also removed the BUG_ON from error return of find_next_chunk in
init_first_rw_device(). It turns out that the only caller of
init_first_rw_device() also BUGS on any nonzero return so no actual behavior
change has occurred here.

do_chunk_alloc() also needed an update since it calls btrfs_alloc_chunk()
which can now return -ENOMEM. Instead of setting space_info->full on any
error from btrfs_alloc_chunk() I catch and return every error value _except_
-ENOSPC. Thanks goes to Tsutomu Itoh for pointing that issue out.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>

2 files changed, 8 insertions, 2 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index aa91773fe31b..f6af4236e59b 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3277,6 +3277,9 @@ again:
         }
 
         ret = btrfs_alloc_chunk(trans, extent_root, flags);
+        if (ret < 0 && ret != -ENOSPC)
+                goto out;
+
         spin_lock(&space_info->lock);
         if (ret)
                 space_info->full = 1;
@@ -3286,6 +3289,7 @@ again:
         space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
         space_info->chunk_alloc = 0;
         spin_unlock(&space_info->lock);
+out:
         mutex_unlock(&extent_root->fs_info->chunk_mutex);
         return ret;
 }
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 530a2fcea1ef..90d956c17d92 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1037,7 +1037,8 @@ static noinline int find_next_chunk(struct btrfs_root *root,
         struct btrfs_key found_key;
 
         path = btrfs_alloc_path();
-        BUG_ON(!path);
+        if (!path)
+                return -ENOMEM;
 
         key.objectid = objectid;
         key.offset = (u64)-1;
@@ -2663,7 +2664,8 @@ static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
 
         ret = find_next_chunk(fs_info->chunk_root,
                               BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
-        BUG_ON(ret);
+        if (ret)
+                return ret;
 
         alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
                         (fs_info->metadata_alloc_profile &