ocfs2: Make ocfs2_extent_tree the first-class representation of a tree.

We now have three different kinds of extent trees in ocfs2: inode data
(dinode), extended attributes (xattr_tree), and extended attribute
values (xattr_value).  There is a nice abstraction for them,
ocfs2_extent_tree, but it is hidden in alloc.c.  All the calling
functions have to pick amongst a varied API and pass in type bits and
often extraneous pointers.

A better way is to make ocfs2_extent_tree a first-class object.
Everyone converts their object to an ocfs2_extent_tree() via the
ocfs2_get_*_extent_tree() calls, then uses the ocfs2_extent_tree for all
tree calls to alloc.c.

This simplifies a lot of callers, making for readability.  It also
provides an easy way to add additional extent tree types, as they only
need to be defined in alloc.c with a ocfs2_get_<new>_extent_tree()
function.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 37 insertions, 34 deletions

diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 1b349c7367a9..9c3d4dc3e2ea 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -206,22 +206,24 @@ static int ocfs2_xattr_extend_allocation(struct inode *inode,
         struct ocfs2_alloc_context *meta_ac = NULL;
         enum ocfs2_alloc_restarted why;
         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
-        struct ocfs2_extent_list *root_el = &xv->xr_list;
         u32 prev_clusters, logical_start = le32_to_cpu(xv->xr_clusters);
+        struct ocfs2_extent_tree et;
 
         mlog(0, "(clusters_to_add for xattr= %u)\n", clusters_to_add);
 
+        ocfs2_get_xattr_value_extent_tree(&et, inode, xattr_bh, xv);
+
 restart_all:
 
-        status = ocfs2_lock_allocators(inode, xattr_bh, root_el,
-                                       clusters_to_add, 0, &data_ac,
-                                       &meta_ac, OCFS2_XATTR_VALUE_EXTENT, xv);
+        status = ocfs2_lock_allocators(inode, &et, clusters_to_add, 0,
+                                       &data_ac, &meta_ac);
         if (status) {
                 mlog_errno(status);
                 goto leave;
         }
 
-        credits = ocfs2_calc_extend_credits(osb->sb, root_el, clusters_to_add);
+        credits = ocfs2_calc_extend_credits(osb->sb, et.et_root_el,
+                                            clusters_to_add);
         handle = ocfs2_start_trans(osb, credits);
         if (IS_ERR(handle)) {
                 status = PTR_ERR(handle);
@@ -244,14 +246,11 @@ restarted_transaction:
                                              &logical_start,
                                              clusters_to_add,
                                              0,
-                                             xattr_bh,
-                                             root_el,
+                                             &et,
                                              handle,
                                              data_ac,
                                              meta_ac,
-                                             &why,
-                                             OCFS2_XATTR_VALUE_EXTENT,
-                                             xv);
+                                             &why);
         if ((status < 0) && (status != -EAGAIN)) {
                 if (status != -ENOSPC)
                         mlog_errno(status);
@@ -276,7 +275,7 @@ restarted_transaction:
                         mlog(0, "restarting transaction.\n");
                         /* TODO: This can be more intelligent. */
                         credits = ocfs2_calc_extend_credits(osb->sb,
-                                                            root_el,
+                                                            et.et_root_el,
                                                             clusters_to_add);
                         status = ocfs2_extend_trans(handle, credits);
                         if (status < 0) {
@@ -308,6 +307,7 @@ leave:
                 goto restart_all;
         }
 
+        ocfs2_put_extent_tree(&et);
         return status;
 }
 
@@ -323,11 +323,13 @@ static int __ocfs2_remove_xattr_range(struct inode *inode,
         struct inode *tl_inode = osb->osb_tl_inode;
         handle_t *handle;
         struct ocfs2_alloc_context *meta_ac = NULL;
+        struct ocfs2_extent_tree et;
+
+        ocfs2_get_xattr_value_extent_tree(&et, inode, root_bh, xv);
 
-        ret = ocfs2_lock_allocators(inode, root_bh, &xv->xr_list,
-                                    0, 1, NULL, &meta_ac,
-                                    OCFS2_XATTR_VALUE_EXTENT, xv);
+        ret = ocfs2_lock_allocators(inode, &et, 0, 1, NULL, &meta_ac);
         if (ret) {
+                ocfs2_put_extent_tree(&et);
                 mlog_errno(ret);
                 return ret;
         }
@@ -356,8 +358,8 @@ static int __ocfs2_remove_xattr_range(struct inode *inode,
                 goto out_commit;
         }
 
-        ret = ocfs2_remove_extent(inode, root_bh, cpos, len, handle, meta_ac,
-                                  dealloc, OCFS2_XATTR_VALUE_EXTENT, xv);
+        ret = ocfs2_remove_extent(inode, &et, cpos, len, handle, meta_ac,
+                                  dealloc);
         if (ret) {
                 mlog_errno(ret);
                 goto out_commit;
@@ -383,6 +385,7 @@ out:
         if (meta_ac)
                 ocfs2_free_alloc_context(meta_ac);
 
+        ocfs2_put_extent_tree(&et);
         return ret;
 }
 
@@ -3622,26 +3625,24 @@ static int ocfs2_add_new_xattr_cluster(struct inode *inode,
         struct ocfs2_alloc_context *data_ac = NULL;
         struct ocfs2_alloc_context *meta_ac = NULL;
         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
-        struct ocfs2_xattr_block *xb =
-                        (struct ocfs2_xattr_block *)root_bh->b_data;
-        struct ocfs2_xattr_tree_root *xb_root = &xb->xb_attrs.xb_root;
-        struct ocfs2_extent_list *root_el = &xb_root->xt_list;
-        enum ocfs2_extent_tree_type type = OCFS2_XATTR_TREE_EXTENT;
+        struct ocfs2_extent_tree et;
 
         mlog(0, "Add new xattr cluster for %llu, previous xattr hash = %u, "
              "previous xattr blkno = %llu\n",
              (unsigned long long)OCFS2_I(inode)->ip_blkno,
              prev_cpos, prev_blkno);
 
-        ret = ocfs2_lock_allocators(inode, root_bh, root_el,
-                                    clusters_to_add, 0, &data_ac,
-                                    &meta_ac, type, NULL);
+        ocfs2_get_xattr_tree_extent_tree(&et, inode, root_bh);
+
+        ret = ocfs2_lock_allocators(inode, &et, clusters_to_add, 0,
+                                    &data_ac, &meta_ac);
         if (ret) {
                 mlog_errno(ret);
                 goto leave;
         }
 
-        credits = ocfs2_calc_extend_credits(osb->sb, root_el, clusters_to_add);
+        credits = ocfs2_calc_extend_credits(osb->sb, et.et_root_el,
+                                            clusters_to_add);
         handle = ocfs2_start_trans(osb, credits);
         if (IS_ERR(handle)) {
                 ret = PTR_ERR(handle);
@@ -3705,9 +3706,8 @@ static int ocfs2_add_new_xattr_cluster(struct inode *inode,
 
         mlog(0, "Insert %u clusters at block %llu for xattr at %u\n",
              num_bits, block, v_start);
-        ret = ocfs2_xattr_tree_insert_extent(osb, handle, inode, root_bh,
-                                             v_start, block, num_bits,
-                                             0, meta_ac);
+        ret = ocfs2_insert_extent(osb, handle, inode, &et, v_start, block,
+                                  num_bits, 0, meta_ac);
         if (ret < 0) {
                 mlog_errno(ret);
                 goto leave;
@@ -3727,6 +3727,7 @@ leave:
         if (meta_ac)
                 ocfs2_free_alloc_context(meta_ac);
 
+        ocfs2_put_extent_tree(&et);
         return ret;
 }
 
@@ -4331,9 +4332,11 @@ static int ocfs2_rm_xattr_cluster(struct inode *inode,
         handle_t *handle;
         struct ocfs2_xattr_block *xb =
                         (struct ocfs2_xattr_block *)root_bh->b_data;
-        struct ocfs2_extent_list *root_el = &xb->xb_attrs.xb_root.xt_list;
         struct ocfs2_alloc_context *meta_ac = NULL;
         struct ocfs2_cached_dealloc_ctxt dealloc;
+        struct ocfs2_extent_tree et;
+
+        ocfs2_get_xattr_tree_extent_tree(&et, inode, root_bh);
 
         ocfs2_init_dealloc_ctxt(&dealloc);
 
@@ -4342,10 +4345,9 @@ static int ocfs2_rm_xattr_cluster(struct inode *inode,
 
         ocfs2_remove_xattr_clusters_from_cache(inode, blkno, len);
 
-        ret = ocfs2_lock_allocators(inode, root_bh, root_el,
-                                    0, 1, NULL, &meta_ac,
-                                    OCFS2_XATTR_TREE_EXTENT, NULL);
+        ret = ocfs2_lock_allocators(inode, &et, 0, 1, NULL, &meta_ac);
         if (ret) {
+                ocfs2_put_extent_tree(&et);
                 mlog_errno(ret);
                 return ret;
         }
@@ -4374,8 +4376,8 @@ static int ocfs2_rm_xattr_cluster(struct inode *inode,
                 goto out_commit;
         }
 
-        ret = ocfs2_remove_extent(inode, root_bh, cpos, len, handle, meta_ac,
-                                  &dealloc, OCFS2_XATTR_TREE_EXTENT, NULL);
+        ret = ocfs2_remove_extent(inode, &et, cpos, len, handle, meta_ac,
+                                  &dealloc);
         if (ret) {
                 mlog_errno(ret);
                 goto out_commit;
@@ -4405,6 +4407,7 @@ out:
 
         ocfs2_run_deallocs(osb, &dealloc);
 
+        ocfs2_put_extent_tree(&et);
         return ret;
 }