1 files changed, 66 insertions, 35 deletions

diff --git a/fs/btrfs/delayed-ref.h b/fs/btrfs/delayed-ref.h
index 04b180ebe1fe..5ce940532144 100644
--- a/fs/btrfs/delayed-ref.h
+++ b/fs/btrfs/delayed-ref.h
@@ -14,6 +14,8 @@
 #include <linux/spinlock.h>
 #include <linux/slab.h>
 #include <uapi/linux/btrfs_tree.h>
+#include "fs.h"
+#include "messages.h"
 
 struct btrfs_trans_handle;
 struct btrfs_fs_info;
@@ -61,7 +63,8 @@ struct btrfs_delayed_ref_node {
 	/*
 	 * If action is BTRFS_ADD_DELAYED_REF, also link this node to
 	 * ref_head->ref_add_list, then we do not need to iterate the
-	 * whole ref_head->ref_list to find BTRFS_ADD_DELAYED_REF nodes.
+	 * refs rbtree in the corresponding delayed ref head
+	 * (struct btrfs_delayed_ref_head::ref_tree).
 	 */
 	struct list_head add_list;
 
@@ -108,7 +111,6 @@ struct btrfs_delayed_ref_node {
 
 struct btrfs_delayed_extent_op {
 	struct btrfs_disk_key key;
-	u8 level;
 	bool update_key;
 	bool update_flags;
 	u64 flags_to_set;
@@ -124,12 +126,6 @@ struct btrfs_delayed_ref_head {
 	u64 bytenr;
 	u64 num_bytes;
 	/*
-	 * For insertion into struct btrfs_delayed_ref_root::href_root.
-	 * Keep it in the same cache line as 'bytenr' for more efficient
-	 * searches in the rbtree.
-	 */
-	struct rb_node href_node;
-	/*
 	 * the mutex is held while running the refs, and it is also
 	 * held when checking the sum of reference modifications.
 	 */
@@ -172,6 +168,9 @@ struct btrfs_delayed_ref_head {
 	 */
 	u64 reserved_bytes;
 
+	/* Tree block level, for metadata only. */
+	u8 level;
+
 	/*
 	 * when a new extent is allocated, it is just reserved in memory
 	 * The actual extent isn't inserted into the extent allocation tree
@@ -189,6 +188,11 @@ struct btrfs_delayed_ref_head {
 	bool is_data;
 	bool is_system;
 	bool processing;
+	/*
+	 * Indicate if it's currently in the data structure that tracks head
+	 * refs (struct btrfs_delayed_ref_root::head_refs).
+	 */
+	bool tracked;
 };
 
 enum btrfs_delayed_ref_flags {
@@ -197,30 +201,52 @@ enum btrfs_delayed_ref_flags {
 };
 
 struct btrfs_delayed_ref_root {
-	/* head ref rbtree */
-	struct rb_root_cached href_root;
-
-	/* dirty extent records */
-	struct rb_root dirty_extent_root;
+	/*
+	 * Track head references.
+	 * The keys correspond to the logical address of the extent ("bytenr")
+	 * right shifted by fs_info->sectorsize_bits. This is both to get a more
+	 * dense index space (optimizes xarray structure) and because indexes in
+	 * xarrays are of "unsigned long" type, meaning they are 32 bits wide on
+	 * 32 bits platforms, limiting the extent range to 4G which is too low
+	 * and makes it unusable (truncated index values) on 32 bits platforms.
+	 * Protected by the spinlock 'lock' defined below.
+	 */
+	struct xarray head_refs;
 
-	/* this spin lock protects the rbtree and the entries inside */
-	spinlock_t lock;
+	/*
+	 * Track dirty extent records.
+	 * The keys correspond to the logical address of the extent ("bytenr")
+	 * right shifted by fs_info->sectorsize_bits, for same reasons as above.
+	 */
+	struct xarray dirty_extents;
 
-	/* how many delayed ref updates we've queued, used by the
-	 * throttling code
+	/*
+	 * Protects the xarray head_refs, its entries and the following fields:
+	 * num_heads, num_heads_ready, pending_csums and run_delayed_start.
 	 */
-	atomic_t num_entries;
+	spinlock_t lock;
 
-	/* total number of head nodes in tree */
+	/* Total number of head refs, protected by the spinlock 'lock'. */
 	unsigned long num_heads;
 
-	/* total number of head nodes ready for processing */
+	/*
+	 * Total number of head refs ready for processing, protected by the
+	 * spinlock 'lock'.
+	 */
 	unsigned long num_heads_ready;
 
+	/*
+	 * Track space reserved for deleting csums of data extents.
+	 * Protected by the spinlock 'lock'.
+	 */
 	u64 pending_csums;
 
 	unsigned long flags;
 
+	/*
+	 * Track from which bytenr to start searching ref heads.
+	 * Protected by the spinlock 'lock'.
+	 */
 	u64 run_delayed_start;
 
 	/*
@@ -236,7 +262,6 @@ enum btrfs_ref_type {
 	BTRFS_REF_NOT_SET,
 	BTRFS_REF_DATA,
 	BTRFS_REF_METADATA,
-	BTRFS_REF_LAST,
 } __packed;
 
 struct btrfs_ref {
@@ -251,10 +276,6 @@ struct btrfs_ref {
 	 */
 	bool skip_qgroup;
 
-#ifdef CONFIG_BTRFS_FS_REF_VERIFY
-	/* Through which root is this modification. */
-	u64 real_root;
-#endif
 	u64 bytenr;
 	u64 num_bytes;
 	u64 owning_root;
@@ -271,6 +292,11 @@ struct btrfs_ref {
 		struct btrfs_data_ref data_ref;
 		struct btrfs_tree_ref tree_ref;
 	};
+
+#ifdef CONFIG_BTRFS_DEBUG
+	/* Through which root is this modification. */
+	u64 real_root;
+#endif
 };
 
 extern struct kmem_cache *btrfs_delayed_ref_head_cachep;
@@ -355,26 +381,30 @@ int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
 			       struct btrfs_ref *generic_ref,
 			       u64 reserved);
 int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
-				u64 bytenr, u64 num_bytes,
+				u64 bytenr, u64 num_bytes, u8 level,
 				struct btrfs_delayed_extent_op *extent_op);
 void btrfs_merge_delayed_refs(struct btrfs_fs_info *fs_info,
 			      struct btrfs_delayed_ref_root *delayed_refs,
 			      struct btrfs_delayed_ref_head *head);
 
 struct btrfs_delayed_ref_head *
-btrfs_find_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
+btrfs_find_delayed_ref_head(const struct btrfs_fs_info *fs_info,
+			    struct btrfs_delayed_ref_root *delayed_refs,
 			    u64 bytenr);
-int btrfs_delayed_ref_lock(struct btrfs_delayed_ref_root *delayed_refs,
-			   struct btrfs_delayed_ref_head *head);
 static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head)
 {
 	mutex_unlock(&head->mutex);
 }
-void btrfs_delete_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
+void btrfs_delete_ref_head(const struct btrfs_fs_info *fs_info,
+			   struct btrfs_delayed_ref_root *delayed_refs,
 			   struct btrfs_delayed_ref_head *head);
 
 struct btrfs_delayed_ref_head *btrfs_select_ref_head(
+		const struct btrfs_fs_info *fs_info,
 		struct btrfs_delayed_ref_root *delayed_refs);
+void btrfs_unselect_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
+			     struct btrfs_delayed_ref_head *head);
+struct btrfs_delayed_ref_node *btrfs_select_delayed_ref(struct btrfs_delayed_ref_head *head);
 
 int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info, u64 seq);
 
@@ -386,11 +416,12 @@ void btrfs_inc_delayed_refs_rsv_bg_updates(struct btrfs_fs_info *fs_info);
 void btrfs_dec_delayed_refs_rsv_bg_updates(struct btrfs_fs_info *fs_info);
 int btrfs_delayed_refs_rsv_refill(struct btrfs_fs_info *fs_info,
 				  enum btrfs_reserve_flush_enum flush);
-void btrfs_migrate_to_delayed_refs_rsv(struct btrfs_fs_info *fs_info,
-				       u64 num_bytes);
 bool btrfs_check_space_for_delayed_refs(struct btrfs_fs_info *fs_info);
+bool btrfs_find_delayed_tree_ref(struct btrfs_delayed_ref_head *head,
+				 u64 root, u64 parent);
+void btrfs_destroy_delayed_refs(struct btrfs_transaction *trans);
 
-static inline u64 btrfs_delayed_ref_owner(struct btrfs_delayed_ref_node *node)
+static inline u64 btrfs_delayed_ref_owner(const struct btrfs_delayed_ref_node *node)
 {
 	if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
 	    node->type == BTRFS_SHARED_DATA_REF_KEY)
@@ -398,7 +429,7 @@ static inline u64 btrfs_delayed_ref_owner(struct btrfs_delayed_ref_node *node)
 	return node->tree_ref.level;
 }
 
-static inline u64 btrfs_delayed_ref_offset(struct btrfs_delayed_ref_node *node)
+static inline u64 btrfs_delayed_ref_offset(const struct btrfs_delayed_ref_node *node)
 {
 	if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
 	    node->type == BTRFS_SHARED_DATA_REF_KEY)
@@ -406,7 +437,7 @@ static inline u64 btrfs_delayed_ref_offset(struct btrfs_delayed_ref_node *node)
 	return 0;
 }
 
-static inline u8 btrfs_ref_type(struct btrfs_ref *ref)
+static inline u8 btrfs_ref_type(const struct btrfs_ref *ref)
 {
 	ASSERT(ref->type == BTRFS_REF_DATA || ref->type == BTRFS_REF_METADATA);