ocfs2: Abstract ocfs2_extent_tree in b-tree operations.

In the old extent tree operation, we take the hypothesis that we
are using the ocfs2_extent_list in ocfs2_dinode as the tree root.
As xattr will also use ocfs2_extent_list to store large value
for a xattr entry, we refactor the tree operation so that xattr
can use it directly.

The refactoring includes 4 steps:
1. Abstract set/get of last_eb_blk and update_clusters since they may
   be stored in different location for dinode and xattr.
2. Add a new structure named ocfs2_extent_tree to indicate the
   extent tree the operation will work on.
3. Remove all the use of fe_bh and di, use root_bh and root_el in
   extent tree instead. So now all the fe_bh is replaced with
   et->root_bh, el with root_el accordingly.
4. Make ocfs2_lock_allocators generic. Now it is limited to be only used
   in file extend allocation. But the whole function is useful when we want
   to store large EAs.

Note: This patch doesn't touch ocfs2_commit_truncate() since it is not used
for anything other than truncate inode data btrees.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index bbe3f8b2d0e2..44ea5eb3fdc4 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -1278,7 +1278,8 @@ static int ocfs2_write_cluster(struct address_space *mapping,
         } else if (unwritten) {
                 ret = ocfs2_mark_extent_written(inode, wc->w_di_bh,
                                                 wc->w_handle, cpos, 1, phys,
-                                                meta_ac, &wc->w_dealloc);
+                                                meta_ac, &wc->w_dealloc,
+                                                OCFS2_DINODE_EXTENT);
                 if (ret < 0) {
                         mlog_errno(ret);
                         goto out;
@@ -1712,7 +1713,13 @@ int ocfs2_write_begin_nolock(struct address_space *mapping,
                  * ocfs2_lock_allocators(). It greatly over-estimates
                  * the work to be done.
                  */
-                ret = ocfs2_lock_allocators(inode, wc->w_di_bh,
+                mlog(0, "extend inode %llu, i_size = %lld, di->i_clusters = %u,"
+                     " clusters_to_add = %u, extents_to_split = %u\n",
+                     (unsigned long long)OCFS2_I(inode)->ip_blkno,
+                     (long long)i_size_read(inode), le32_to_cpu(di->i_clusters),
+                     clusters_to_alloc, extents_to_split);
+
+                ret = ocfs2_lock_allocators(inode, wc->w_di_bh, &di->id2.i_list,
                                             clusters_to_alloc, extents_to_split,
                                             &data_ac, &meta_ac);
                 if (ret) {