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-rw-r--r--fs/btrfs/transaction.h275
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diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
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+++ b/fs/btrfs/transaction.h
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+/* 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"
+#include "misc.h"
+
+/* Radix-tree tag for roots that are part of the trasaction. */
+#define BTRFS_ROOT_TRANS_TAG 0
+
+enum btrfs_trans_state {
+ TRANS_STATE_RUNNING,
+ TRANS_STATE_COMMIT_PREP,
+ 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;
+};
+
+enum {
+ ENUM_BIT(__TRANS_FREEZABLE),
+ ENUM_BIT(__TRANS_START),
+ ENUM_BIT(__TRANS_ATTACH),
+ ENUM_BIT(__TRANS_JOIN),
+ ENUM_BIT(__TRANS_JOIN_NOLOCK),
+ ENUM_BIT(__TRANS_DUMMY),
+ ENUM_BIT(__TRANS_JOIN_NOSTART),
+};
+
+#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;
+}
+
+bool __cold abort_should_print_stack(int errno);
+
+/*
+ * Call btrfs_abort_transaction as early as possible when an error condition is
+ * detected, that way the exact stack trace is reported for some errors.
+ */
+#define btrfs_abort_transaction(trans, errno) \
+do { \
+ bool first = false; \
+ /* Report first abort since mount */ \
+ if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED, \
+ &((trans)->fs_info->fs_state))) { \
+ first = true; \
+ if (WARN(abort_should_print_stack(errno), \
+ KERN_ERR \
+ "BTRFS: Transaction aborted (error %d)\n", \
+ (errno))) { \
+ /* Stack trace printed. */ \
+ } else { \
+ btrfs_err((trans)->fs_info, \
+ "Transaction aborted (error %d)", \
+ (errno)); \
+ } \
+ } \
+ __btrfs_abort_transaction((trans), __func__, \
+ __LINE__, (errno), first); \
+} while (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_add_dropped_root(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root);
+void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans);
+void __cold __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
+ const char *function,
+ unsigned int line, int errno, bool first_hit);
+
+int __init btrfs_transaction_init(void);
+void __cold btrfs_transaction_exit(void);
+
+#endif