btrfs: allow dedupe of same inode

[cascardo/linux.git] / fs / btrfs / delayed-ref.h

diff --git a/fs/btrfs/delayed-ref.h b/fs/btrfs/delayed-ref.h
index a764e23..13fb5e6 100644 (file)
--- a/fs/btrfs/delayed-ref.h
+++ b/fs/btrfs/delayed-ref.h
@@ -24,9 +24,25 @@
 #define BTRFS_ADD_DELAYED_EXTENT 3 /* record a full extent allocation */
 #define BTRFS_UPDATE_DELAYED_HEAD 4 /* not changing ref count on head ref */
 
+/*
+ * XXX: Qu: I really hate the design that ref_head and tree/data ref shares the
+ * same ref_node structure.
+ * Ref_head is in a higher logic level than tree/data ref, and duplicated
+ * bytenr/num_bytes in ref_node is really a waste or memory, they should be
+ * referred from ref_head.
+ * This gets more disgusting after we use list to store tree/data ref in
+ * ref_head. Must clean this mess up later.
+ */
 struct btrfs_delayed_ref_node {
+       /*
+        * ref_head use rb tree, stored in ref_root->href.
+        * indexed by bytenr
+        */
        struct rb_node rb_node;
 
+       /*data/tree ref use list, stored in ref_head->ref_list. */
+       struct list_head list;
+
        /* the starting bytenr of the extent */
        u64 bytenr;
 
@@ -83,11 +99,19 @@ struct btrfs_delayed_ref_head {
        struct mutex mutex;
 
        spinlock_t lock;
-       struct rb_root ref_root;
+       struct list_head ref_list;
 
        struct rb_node href_node;
 
        struct btrfs_delayed_extent_op *extent_op;
+
+       /*
+        * This is used to track the final ref_mod from all the refs associated
+        * with this head ref, this is not adjusted as delayed refs are run,
+        * this is meant to track if we need to do the csum accounting or not.
+        */
+       int total_ref_mod;
+
        /*
         * when a new extent is allocated, it is just reserved in memory
         * The actual extent isn't inserted into the extent allocation tree
@@ -124,6 +148,9 @@ struct btrfs_delayed_ref_root {
        /* head ref rbtree */
        struct rb_root href_root;
 
+       /* dirty extent records */
+       struct rb_root dirty_extent_root;
+
        /* this spin lock protects the rbtree and the entries inside */
        spinlock_t lock;
 
@@ -138,6 +165,8 @@ struct btrfs_delayed_ref_root {
        /* total number of head nodes ready for processing */
        unsigned long num_heads_ready;
 
+       u64 pending_csums;
+
        /*
         * set when the tree is flushing before a transaction commit,
         * used by the throttling code to decide if new updates need
@@ -146,6 +175,14 @@ struct btrfs_delayed_ref_root {
        int flushing;
 
        u64 run_delayed_start;
+
+       /*
+        * To make qgroup to skip given root.
+        * This is for snapshot, as btrfs_qgroup_inherit() will manully
+        * modify counters for snapshot and its source, so we should skip
+        * the snapshot in new_root/old_roots or it will get calculated twice
+        */
+       u64 qgroup_to_skip;
 };
 
 extern struct kmem_cache *btrfs_delayed_ref_head_cachep;