Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 286 insertions, 0 deletions

diff --git a/fs/btrfs/delayed-ref.h b/fs/btrfs/delayed-ref.h
new file mode 100644
index 000000000..d9f2a4ebd
--- /dev/null
+++ b/fs/btrfs/delayed-ref.h
@@ -0,0 +1,286 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2008 Oracle.  All rights reserved.
+ */
+
+#ifndef BTRFS_DELAYED_REF_H
+#define BTRFS_DELAYED_REF_H
+
+#include <linux/refcount.h>
+
+/* these are the possible values of struct btrfs_delayed_ref_node->action */
+#define BTRFS_ADD_DELAYED_REF    1 /* add one backref to the tree */
+#define BTRFS_DROP_DELAYED_REF   2 /* delete one backref from the tree */
+#define BTRFS_ADD_DELAYED_EXTENT 3 /* record a full extent allocation */
+#define BTRFS_UPDATE_DELAYED_HEAD 4 /* not changing ref count on head ref */
+
+struct btrfs_delayed_ref_node {
+	struct rb_node 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.
+	 */
+	struct list_head add_list;
+
+	/* the starting bytenr of the extent */
+	u64 bytenr;
+
+	/* the size of the extent */
+	u64 num_bytes;
+
+	/* seq number to keep track of insertion order */
+	u64 seq;
+
+	/* ref count on this data structure */
+	refcount_t refs;
+
+	/*
+	 * how many refs is this entry adding or deleting.  For
+	 * head refs, this may be a negative number because it is keeping
+	 * track of the total mods done to the reference count.
+	 * For individual refs, this will always be a positive number
+	 *
+	 * It may be more than one, since it is possible for a single
+	 * parent to have more than one ref on an extent
+	 */
+	int ref_mod;
+
+	unsigned int action:8;
+	unsigned int type:8;
+	/* is this node still in the rbtree? */
+	unsigned int is_head:1;
+	unsigned int in_tree:1;
+};
+
+struct btrfs_delayed_extent_op {
+	struct btrfs_disk_key key;
+	u8 level;
+	bool update_key;
+	bool update_flags;
+	bool is_data;
+	u64 flags_to_set;
+};
+
+/*
+ * the head refs are used to hold a lock on a given extent, which allows us
+ * to make sure that only one process is running the delayed refs
+ * at a time for a single extent.  They also store the sum of all the
+ * reference count modifications we've queued up.
+ */
+struct btrfs_delayed_ref_head {
+	u64 bytenr;
+	u64 num_bytes;
+	refcount_t refs;
+	/*
+	 * the mutex is held while running the refs, and it is also
+	 * held when checking the sum of reference modifications.
+	 */
+	struct mutex mutex;
+
+	spinlock_t lock;
+	struct rb_root ref_tree;
+	/* accumulate add BTRFS_ADD_DELAYED_REF nodes to this ref_add_list. */
+	struct list_head ref_add_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;
+
+	/*
+	 * This is the current outstanding mod references for this bytenr.  This
+	 * is used with lookup_extent_info to get an accurate reference count
+	 * for a bytenr, so it is adjusted as delayed refs are run so that any
+	 * on disk reference count + ref_mod is accurate.
+	 */
+	int ref_mod;
+
+	/*
+	 * For qgroup reserved space freeing.
+	 *
+	 * ref_root and reserved will be recorded after
+	 * BTRFS_ADD_DELAYED_EXTENT is called.
+	 * And will be used to free reserved qgroup space at
+	 * run_delayed_refs() time.
+	 */
+	u64 qgroup_ref_root;
+	u64 qgroup_reserved;
+
+	/*
+	 * when a new extent is allocated, it is just reserved in memory
+	 * The actual extent isn't inserted into the extent allocation tree
+	 * until the delayed ref is processed.  must_insert_reserved is
+	 * used to flag a delayed ref so the accounting can be updated
+	 * when a full insert is done.
+	 *
+	 * It is possible the extent will be freed before it is ever
+	 * inserted into the extent allocation tree.  In this case
+	 * we need to update the in ram accounting to properly reflect
+	 * the free has happened.
+	 */
+	unsigned int must_insert_reserved:1;
+	unsigned int is_data:1;
+	unsigned int is_system:1;
+	unsigned int processing:1;
+};
+
+struct btrfs_delayed_tree_ref {
+	struct btrfs_delayed_ref_node node;
+	u64 root;
+	u64 parent;
+	int level;
+};
+
+struct btrfs_delayed_data_ref {
+	struct btrfs_delayed_ref_node node;
+	u64 root;
+	u64 parent;
+	u64 objectid;
+	u64 offset;
+};
+
+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;
+
+	/* how many delayed ref updates we've queued, used by the
+	 * throttling code
+	 */
+	atomic_t num_entries;
+
+	/* total number of head nodes in tree */
+	unsigned long num_heads;
+
+	/* 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
+	 * to be run right away
+	 */
+	int flushing;
+
+	u64 run_delayed_start;
+
+	/*
+	 * To make qgroup to skip given root.
+	 * This is for snapshot, as btrfs_qgroup_inherit() will manually
+	 * 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;
+extern struct kmem_cache *btrfs_delayed_tree_ref_cachep;
+extern struct kmem_cache *btrfs_delayed_data_ref_cachep;
+extern struct kmem_cache *btrfs_delayed_extent_op_cachep;
+
+int __init btrfs_delayed_ref_init(void);
+void __cold btrfs_delayed_ref_exit(void);
+
+static inline struct btrfs_delayed_extent_op *
+btrfs_alloc_delayed_extent_op(void)
+{
+	return kmem_cache_alloc(btrfs_delayed_extent_op_cachep, GFP_NOFS);
+}
+
+static inline void
+btrfs_free_delayed_extent_op(struct btrfs_delayed_extent_op *op)
+{
+	if (op)
+		kmem_cache_free(btrfs_delayed_extent_op_cachep, op);
+}
+
+static inline void btrfs_put_delayed_ref(struct btrfs_delayed_ref_node *ref)
+{
+	WARN_ON(refcount_read(&ref->refs) == 0);
+	if (refcount_dec_and_test(&ref->refs)) {
+		WARN_ON(ref->in_tree);
+		switch (ref->type) {
+		case BTRFS_TREE_BLOCK_REF_KEY:
+		case BTRFS_SHARED_BLOCK_REF_KEY:
+			kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
+			break;
+		case BTRFS_EXTENT_DATA_REF_KEY:
+		case BTRFS_SHARED_DATA_REF_KEY:
+			kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
+			break;
+		default:
+			BUG();
+		}
+	}
+}
+
+static inline void btrfs_put_delayed_ref_head(struct btrfs_delayed_ref_head *head)
+{
+	if (refcount_dec_and_test(&head->refs))
+		kmem_cache_free(btrfs_delayed_ref_head_cachep, head);
+}
+
+int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
+			       u64 bytenr, u64 num_bytes, u64 parent,
+			       u64 ref_root, int level, int action,
+			       struct btrfs_delayed_extent_op *extent_op,
+			       int *old_ref_mod, int *new_ref_mod);
+int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
+			       u64 bytenr, u64 num_bytes,
+			       u64 parent, u64 ref_root,
+			       u64 owner, u64 offset, u64 reserved, int action,
+			       int *old_ref_mod, int *new_ref_mod);
+int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
+				struct btrfs_trans_handle *trans,
+				u64 bytenr, u64 num_bytes,
+				struct btrfs_delayed_extent_op *extent_op);
+void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
+			      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,
+			    u64 bytenr);
+int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
+			   struct btrfs_delayed_ref_head *head);
+static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head)
+{
+	mutex_unlock(&head->mutex);
+}
+
+
+struct btrfs_delayed_ref_head *
+btrfs_select_ref_head(struct btrfs_trans_handle *trans);
+
+int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info, u64 seq);
+
+/*
+ * helper functions to cast a node into its container
+ */
+static inline struct btrfs_delayed_tree_ref *
+btrfs_delayed_node_to_tree_ref(struct btrfs_delayed_ref_node *node)
+{
+	return container_of(node, struct btrfs_delayed_tree_ref, node);
+}
+
+static inline struct btrfs_delayed_data_ref *
+btrfs_delayed_node_to_data_ref(struct btrfs_delayed_ref_node *node)
+{
+	return container_of(node, struct btrfs_delayed_data_ref, node);
+}
+
+#endif