Btrfs: Implement generation numbers in block pointers

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 58 insertions, 2 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 8ab4954f6ad0..0f1ebdd4e925 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -17,6 +17,7 @@
  */
 
 #include <linux/sched.h>
+#include "hash.h"
 #include "ctree.h"
 #include "disk-io.h"
 #include "print-tree.h"
@@ -352,9 +353,63 @@ found:
         return found_group;
 }
 
+static u64 hash_extent_ref(u64 root_objectid, u64 root_generation,
+                           u64 owner, u64 owner_offset)
+{
+        u32 high_crc = ~(u32)0;
+        u32 low_crc = ~(u32)0;
+        __le64 lenum;
+
+        lenum = cpu_to_le64(root_objectid);
+        high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
+        lenum = cpu_to_le64(root_generation);
+        high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
+
+        lenum = cpu_to_le64(owner);
+        low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
+
+        lenum = cpu_to_le64(owner_offset);
+        low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
+
+        return ((u64)high_crc << 32) | (u64)low_crc;
+}
+
+int insert_extent_ref(struct btrfs_trans_handle *trans,
+                                struct btrfs_root *root,
+                                struct btrfs_path *path,
+                                u64 bytenr,
+                                u64 root_objectid, u64 root_generation,
+                                u64 owner, u64 owner_offset)
+{
+        u64 hash;
+        struct btrfs_key key;
+        struct btrfs_extent_ref ref;
+        struct extent_buffer *l;
+        struct btrfs_extent_item *item;
+        int ret;
+
+        btrfs_set_stack_ref_root(&ref, root_objectid);
+        btrfs_set_stack_ref_generation(&ref, root_generation);
+        btrfs_set_stack_ref_objectid(&ref, owner);
+        btrfs_set_stack_ref_offset(&ref, owner_offset);
+
+        ret = btrfs_name_hash(&ref, sizeof(ref), &hash);
+        key.offset = hash;
+        key.objectid = bytenr;
+        key.type = BTRFS_EXTENT_REF_KEY;
+
+        ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref));
+        while (ret == -EEXIST) {
+
+        }
+
+}
+
 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
                                 struct btrfs_root *root,
-                                u64 bytenr, u64 num_bytes)
+                                u64 bytenr, u64 num_bytes,
+                                u64 root_objectid, u64 root_generation,
+                                u64 owner, u64 owner_offset)
 {
         struct btrfs_path *path;
         int ret;
@@ -386,9 +441,10 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
         btrfs_mark_buffer_dirty(path->nodes[0]);
 
         btrfs_release_path(root->fs_info->extent_root, path);
-        btrfs_free_path(path);
         finish_current_insert(trans, root->fs_info->extent_root);
         del_pending_extents(trans, root->fs_info->extent_root);
+
+        btrfs_free_path(path);
         return 0;
 }