1 files changed, 239 insertions, 0 deletions
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
new file mode 100644
index 000000000..970ff3160
--- /dev/null
+++ b/fs/btrfs/transaction.h
@@ -0,0 +1,239 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2007 Oracle.  All rights reserved.
+ */
+
+#ifndef BTRFS_TRANSACTION_H
+#define BTRFS_TRANSACTION_H
+
+#include <linux/refcount.h>
+#include "btrfs_inode.h"
+#include "delayed-ref.h"
+#include "ctree.h"
+
+enum btrfs_trans_state {
+	TRANS_STATE_RUNNING,
+	TRANS_STATE_COMMIT_START,
+	TRANS_STATE_COMMIT_DOING,
+	TRANS_STATE_UNBLOCKED,
+	TRANS_STATE_SUPER_COMMITTED,
+	TRANS_STATE_COMPLETED,
+	TRANS_STATE_MAX,
+};
+
+#define BTRFS_TRANS_HAVE_FREE_BGS	0
+#define BTRFS_TRANS_DIRTY_BG_RUN	1
+#define BTRFS_TRANS_CACHE_ENOSPC	2
+
+struct btrfs_transaction {
+	u64 transid;
+	/*
+	 * total external writers(USERSPACE/START/ATTACH) in this
+	 * transaction, it must be zero before the transaction is
+	 * being committed
+	 */
+	atomic_t num_extwriters;
+	/*
+	 * total writers in this transaction, it must be zero before the
+	 * transaction can end
+	 */
+	atomic_t num_writers;
+	refcount_t use_count;
+
+	unsigned long flags;
+
+	/* Be protected by fs_info->trans_lock when we want to change it. */
+	enum btrfs_trans_state state;
+	int aborted;
+	struct list_head list;
+	struct extent_io_tree dirty_pages;
+	time64_t start_time;
+	wait_queue_head_t writer_wait;
+	wait_queue_head_t commit_wait;
+	struct list_head pending_snapshots;
+	struct list_head dev_update_list;
+	struct list_head switch_commits;
+	struct list_head dirty_bgs;
+
+	/*
+	 * There is no explicit lock which protects io_bgs, rather its
+	 * consistency is implied by the fact that all the sites which modify
+	 * it do so under some form of transaction critical section, namely:
+	 *
+	 * - btrfs_start_dirty_block_groups - This function can only ever be
+	 *   run by one of the transaction committers. Refer to
+	 *   BTRFS_TRANS_DIRTY_BG_RUN usage in btrfs_commit_transaction
+	 *
+	 * - btrfs_write_dirty_blockgroups - this is called by
+	 *   commit_cowonly_roots from transaction critical section
+	 *   (TRANS_STATE_COMMIT_DOING)
+	 *
+	 * - btrfs_cleanup_dirty_bgs - called on transaction abort
+	 */
+	struct list_head io_bgs;
+	struct list_head dropped_roots;
+	struct extent_io_tree pinned_extents;
+
+	/*
+	 * we need to make sure block group deletion doesn't race with
+	 * free space cache writeout.  This mutex keeps them from stomping
+	 * on each other
+	 */
+	struct mutex cache_write_mutex;
+	spinlock_t dirty_bgs_lock;
+	/* Protected by spin lock fs_info->unused_bgs_lock. */
+	struct list_head deleted_bgs;
+	spinlock_t dropped_roots_lock;
+	struct btrfs_delayed_ref_root delayed_refs;
+	struct btrfs_fs_info *fs_info;
+
+	/*
+	 * Number of ordered extents the transaction must wait for before
+	 * committing. These are ordered extents started by a fast fsync.
+	 */
+	atomic_t pending_ordered;
+	wait_queue_head_t pending_wait;
+
+	spinlock_t releasing_ebs_lock;
+	struct list_head releasing_ebs;
+};
+
+#define __TRANS_FREEZABLE	(1U << 0)
+
+#define __TRANS_START		(1U << 9)
+#define __TRANS_ATTACH		(1U << 10)
+#define __TRANS_JOIN		(1U << 11)
+#define __TRANS_JOIN_NOLOCK	(1U << 12)
+#define __TRANS_DUMMY		(1U << 13)
+#define __TRANS_JOIN_NOSTART	(1U << 14)
+
+#define TRANS_START		(__TRANS_START | __TRANS_FREEZABLE)
+#define TRANS_ATTACH		(__TRANS_ATTACH)
+#define TRANS_JOIN		(__TRANS_JOIN | __TRANS_FREEZABLE)
+#define TRANS_JOIN_NOLOCK	(__TRANS_JOIN_NOLOCK)
+#define TRANS_JOIN_NOSTART	(__TRANS_JOIN_NOSTART)
+
+#define TRANS_EXTWRITERS	(__TRANS_START | __TRANS_ATTACH)
+
+struct btrfs_trans_handle {
+	u64 transid;
+	u64 bytes_reserved;
+	u64 chunk_bytes_reserved;
+	unsigned long delayed_ref_updates;
+	struct btrfs_transaction *transaction;
+	struct btrfs_block_rsv *block_rsv;
+	struct btrfs_block_rsv *orig_rsv;
+	/* Set by a task that wants to create a snapshot. */
+	struct btrfs_pending_snapshot *pending_snapshot;
+	refcount_t use_count;
+	unsigned int type;
+	/*
+	 * Error code of transaction abort, set outside of locks and must use
+	 * the READ_ONCE/WRITE_ONCE access
+	 */
+	short aborted;
+	bool adding_csums;
+	bool allocating_chunk;
+	bool removing_chunk;
+	bool reloc_reserved;
+	bool in_fsync;
+	struct btrfs_fs_info *fs_info;
+	struct list_head new_bgs;
+};
+
+/*
+ * The abort status can be changed between calls and is not protected by locks.
+ * This accepts btrfs_transaction and btrfs_trans_handle as types. Once it's
+ * set to a non-zero value it does not change, so the macro should be in checks
+ * but is not necessary for further reads of the value.
+ */
+#define TRANS_ABORTED(trans)		(unlikely(READ_ONCE((trans)->aborted)))
+
+struct btrfs_pending_snapshot {
+	struct dentry *dentry;
+	struct inode *dir;
+	struct btrfs_root *root;
+	struct btrfs_root_item *root_item;
+	struct btrfs_root *snap;
+	struct btrfs_qgroup_inherit *inherit;
+	struct btrfs_path *path;
+	/* block reservation for the operation */
+	struct btrfs_block_rsv block_rsv;
+	/* extra metadata reservation for relocation */
+	int error;
+	/* Preallocated anonymous block device number */
+	dev_t anon_dev;
+	bool readonly;
+	struct list_head list;
+};
+
+static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
+					      struct btrfs_inode *inode)
+{
+	spin_lock(&inode->lock);
+	inode->last_trans = trans->transaction->transid;
+	inode->last_sub_trans = inode->root->log_transid;
+	inode->last_log_commit = inode->last_sub_trans - 1;
+	spin_unlock(&inode->lock);
+}
+
+/*
+ * Make qgroup codes to skip given qgroupid, means the old/new_roots for
+ * qgroup won't contain the qgroupid in it.
+ */
+static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
+					 u64 qgroupid)
+{
+	struct btrfs_delayed_ref_root *delayed_refs;
+
+	delayed_refs = &trans->transaction->delayed_refs;
+	WARN_ON(delayed_refs->qgroup_to_skip);
+	delayed_refs->qgroup_to_skip = qgroupid;
+}
+
+static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_delayed_ref_root *delayed_refs;
+
+	delayed_refs = &trans->transaction->delayed_refs;
+	WARN_ON(!delayed_refs->qgroup_to_skip);
+	delayed_refs->qgroup_to_skip = 0;
+}
+
+int btrfs_end_transaction(struct btrfs_trans_handle *trans);
+struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
+						   unsigned int num_items);
+struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
+					struct btrfs_root *root,
+					unsigned int num_items);
+struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
+struct btrfs_trans_handle *btrfs_join_transaction_spacecache(struct btrfs_root *root);
+struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root);
+struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
+struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
+					struct btrfs_root *root);
+int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
+
+void btrfs_add_dead_root(struct btrfs_root *root);
+int btrfs_defrag_root(struct btrfs_root *root);
+void btrfs_maybe_wake_unfinished_drop(struct btrfs_fs_info *fs_info);
+int btrfs_clean_one_deleted_snapshot(struct btrfs_fs_info *fs_info);
+int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
+void btrfs_commit_transaction_async(struct btrfs_trans_handle *trans);
+int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
+bool btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
+void btrfs_throttle(struct btrfs_fs_info *fs_info);
+int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
+				struct btrfs_root *root);
+int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
+				struct extent_io_tree *dirty_pages, int mark);
+int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark);
+int btrfs_transaction_blocked(struct btrfs_fs_info *info);
+int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
+void btrfs_put_transaction(struct btrfs_transaction *transaction);
+void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info);
+void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
+			    struct btrfs_root *root);
+void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans);
+
+#endif