Btrfs: mount ro and remount support

This patch adds mount ro and remount support. The main
changes in patch are: adding btrfs_remount and related
helper function; splitting the transaction related code
out of close_ctree into btrfs_commit_super; updating
allocator to properly handle read only block group.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index f575939e025..c4c6c127323 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -541,6 +541,7 @@ struct btrfs_space_info {
         u64 bytes_used;
         u64 bytes_pinned;
         u64 bytes_reserved;
+        u64 bytes_readonly;
         int full;
         int force_alloc;
         struct list_head list;