Btrfs: Implement generation numbers in block pointers

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

1 files changed, 41 insertions, 6 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 9bc1b0a8615f..fd58dd846e61 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -110,7 +110,7 @@ struct btrfs_header {
 #define BTRFS_MAX_LEVEL 8
 #define BTRFS_NODEPTRS_PER_BLOCK(r) (((r)->nodesize - \
                                 sizeof(struct btrfs_header)) / \
-                               (sizeof(struct btrfs_disk_key) + sizeof(u64)))
+                                sizeof(struct btrfs_key_ptr))
 #define __BTRFS_LEAF_DATA_SIZE(bs) ((bs) - sizeof(struct btrfs_header))
 #define BTRFS_LEAF_DATA_SIZE(r) (__BTRFS_LEAF_DATA_SIZE(r->leafsize))
 #define BTRFS_MAX_INLINE_DATA_SIZE(r) (BTRFS_LEAF_DATA_SIZE(r) - \
@@ -168,6 +168,7 @@ struct btrfs_leaf {
 struct btrfs_key_ptr {
         struct btrfs_disk_key key;
         __le64 blockptr;
+        __le64 generation;
 } __attribute__ ((__packed__));
 
 struct btrfs_node {
@@ -196,7 +197,13 @@ struct btrfs_path {
  */
 struct btrfs_extent_item {
         __le32 refs;
-        __le64 owner;
+} __attribute__ ((__packed__));
+
+struct btrfs_extent_ref {
+        __le64 root;
+        __le64 generation;
+        __le64 objectid;
+        __le64 offset;
 } __attribute__ ((__packed__));
 
 struct btrfs_inode_timespec {
@@ -402,12 +409,13 @@ struct btrfs_root {
  * are used, and how many references there are to each block
  */
 #define BTRFS_EXTENT_ITEM_KEY   33
+#define BTRFS_EXTENT_REF_KEY    34
 
 /*
  * block groups give us hints into the extent allocation trees.  Which
  * blocks are free etc etc
  */
-#define BTRFS_BLOCK_GROUP_ITEM_KEY 34
+#define BTRFS_BLOCK_GROUP_ITEM_KEY 50
 
 /*
  * string items are for debugging.  They just store a short string of
@@ -529,15 +537,25 @@ BTRFS_SETGET_FUNCS(timespec_nsec, struct btrfs_inode_timespec, nsec, 32);
 
 /* struct btrfs_extent_item */
 BTRFS_SETGET_FUNCS(extent_refs, struct btrfs_extent_item, refs, 32);
-BTRFS_SETGET_FUNCS(extent_owner, struct btrfs_extent_item, owner, 64);
+
+/* struct btrfs_extent_ref */
+BTRFS_SETGET_FUNCS(ref_root, struct btrfs_extent_ref, root, 64);
+BTRFS_SETGET_FUNCS(ref_generation, struct btrfs_extent_ref, generation, 64);
+BTRFS_SETGET_FUNCS(ref_objectid, struct btrfs_extent_ref, objectid, 64);
+BTRFS_SETGET_FUNCS(ref_offset, struct btrfs_extent_ref, offset, 64);
+
+BTRFS_SETGET_STACK_FUNCS(ref_root, struct btrfs_extent_ref, root, 64);
+BTRFS_SETGET_STACK_FUNCS(ref_generation, struct btrfs_extent_ref,
+                         generation, 64);
+BTRFS_SETGET_STACK_FUNCS(ref_objectid, struct btrfs_extent_ref, objectid, 64);
+BTRFS_SETGET_STACK_FUNCS(ref_offset, struct btrfs_extent_ref, offset, 64);
 
 BTRFS_SETGET_STACK_FUNCS(stack_extent_refs, struct btrfs_extent_item,
                          refs, 32);
-BTRFS_SETGET_STACK_FUNCS(stack_extent_owner, struct btrfs_extent_item,
-                         owner, 64);
 
 /* struct btrfs_node */
 BTRFS_SETGET_FUNCS(key_blockptr, struct btrfs_key_ptr, blockptr, 64);
+BTRFS_SETGET_FUNCS(key_generation, struct btrfs_key_ptr, generation, 64);
 
 static inline u64 btrfs_node_blockptr(struct extent_buffer *eb, int nr)
 {
@@ -556,6 +574,23 @@ static inline void btrfs_set_node_blockptr(struct extent_buffer *eb,
         btrfs_set_key_blockptr(eb, (struct btrfs_key_ptr *)ptr, val);
 }
 
+static inline u64 btrfs_node_ptr_generation(struct extent_buffer *eb, int nr)
+{
+        unsigned long ptr;
+        ptr = offsetof(struct btrfs_node, ptrs) +
+                sizeof(struct btrfs_key_ptr) * nr;
+        return btrfs_key_generation(eb, (struct btrfs_key_ptr *)ptr);
+}
+
+static inline void btrfs_set_node_ptr_generation(struct extent_buffer *eb,
+                                                 int nr, u64 val)
+{
+        unsigned long ptr;
+        ptr = offsetof(struct btrfs_node, ptrs) +
+                sizeof(struct btrfs_key_ptr) * nr;
+        btrfs_set_key_generation(eb, (struct btrfs_key_ptr *)ptr, val);
+}
+
 static inline unsigned long btrfs_node_key_ptr_offset(int nr)
 {
         return offsetof(struct btrfs_node, ptrs) +