xref: /kernel/linux/linux-5.10/fs/btrfs/transaction.h (revision 8c2ecf20)
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2007 Oracle.  All rights reserved.
4 */
5
6#ifndef BTRFS_TRANSACTION_H
7#define BTRFS_TRANSACTION_H
8
9#include <linux/refcount.h>
10#include "btrfs_inode.h"
11#include "delayed-ref.h"
12#include "ctree.h"
13
14enum btrfs_trans_state {
15	TRANS_STATE_RUNNING,
16	TRANS_STATE_COMMIT_START,
17	TRANS_STATE_COMMIT_DOING,
18	TRANS_STATE_UNBLOCKED,
19	TRANS_STATE_COMPLETED,
20	TRANS_STATE_MAX,
21};
22
23#define BTRFS_TRANS_HAVE_FREE_BGS	0
24#define BTRFS_TRANS_DIRTY_BG_RUN	1
25#define BTRFS_TRANS_CACHE_ENOSPC	2
26
27struct btrfs_transaction {
28	u64 transid;
29	/*
30	 * total external writers(USERSPACE/START/ATTACH) in this
31	 * transaction, it must be zero before the transaction is
32	 * being committed
33	 */
34	atomic_t num_extwriters;
35	/*
36	 * total writers in this transaction, it must be zero before the
37	 * transaction can end
38	 */
39	atomic_t num_writers;
40	refcount_t use_count;
41
42	unsigned long flags;
43
44	/* Be protected by fs_info->trans_lock when we want to change it. */
45	enum btrfs_trans_state state;
46	int aborted;
47	struct list_head list;
48	struct extent_io_tree dirty_pages;
49	time64_t start_time;
50	wait_queue_head_t writer_wait;
51	wait_queue_head_t commit_wait;
52	struct list_head pending_snapshots;
53	struct list_head dev_update_list;
54	struct list_head switch_commits;
55	struct list_head dirty_bgs;
56
57	/*
58	 * There is no explicit lock which protects io_bgs, rather its
59	 * consistency is implied by the fact that all the sites which modify
60	 * it do so under some form of transaction critical section, namely:
61	 *
62	 * - btrfs_start_dirty_block_groups - This function can only ever be
63	 *   run by one of the transaction committers. Refer to
64	 *   BTRFS_TRANS_DIRTY_BG_RUN usage in btrfs_commit_transaction
65	 *
66	 * - btrfs_write_dirty_blockgroups - this is called by
67	 *   commit_cowonly_roots from transaction critical section
68	 *   (TRANS_STATE_COMMIT_DOING)
69	 *
70	 * - btrfs_cleanup_dirty_bgs - called on transaction abort
71	 */
72	struct list_head io_bgs;
73	struct list_head dropped_roots;
74	struct extent_io_tree pinned_extents;
75
76	/*
77	 * we need to make sure block group deletion doesn't race with
78	 * free space cache writeout.  This mutex keeps them from stomping
79	 * on each other
80	 */
81	struct mutex cache_write_mutex;
82	spinlock_t dirty_bgs_lock;
83	/* Protected by spin lock fs_info->unused_bgs_lock. */
84	struct list_head deleted_bgs;
85	spinlock_t dropped_roots_lock;
86	struct btrfs_delayed_ref_root delayed_refs;
87	struct btrfs_fs_info *fs_info;
88
89	/*
90	 * Number of ordered extents the transaction must wait for before
91	 * committing. These are ordered extents started by a fast fsync.
92	 */
93	atomic_t pending_ordered;
94	wait_queue_head_t pending_wait;
95};
96
97#define __TRANS_FREEZABLE	(1U << 0)
98
99#define __TRANS_START		(1U << 9)
100#define __TRANS_ATTACH		(1U << 10)
101#define __TRANS_JOIN		(1U << 11)
102#define __TRANS_JOIN_NOLOCK	(1U << 12)
103#define __TRANS_DUMMY		(1U << 13)
104#define __TRANS_JOIN_NOSTART	(1U << 14)
105
106#define TRANS_START		(__TRANS_START | __TRANS_FREEZABLE)
107#define TRANS_ATTACH		(__TRANS_ATTACH)
108#define TRANS_JOIN		(__TRANS_JOIN | __TRANS_FREEZABLE)
109#define TRANS_JOIN_NOLOCK	(__TRANS_JOIN_NOLOCK)
110#define TRANS_JOIN_NOSTART	(__TRANS_JOIN_NOSTART)
111
112#define TRANS_EXTWRITERS	(__TRANS_START | __TRANS_ATTACH)
113
114#define BTRFS_SEND_TRANS_STUB	((void *)1)
115#define BTRFS_DIO_SYNC_STUB	((void *)2)
116
117struct btrfs_trans_handle {
118	u64 transid;
119	u64 bytes_reserved;
120	u64 chunk_bytes_reserved;
121	unsigned long delayed_ref_updates;
122	struct btrfs_transaction *transaction;
123	struct btrfs_block_rsv *block_rsv;
124	struct btrfs_block_rsv *orig_rsv;
125	refcount_t use_count;
126	unsigned int type;
127	/*
128	 * Error code of transaction abort, set outside of locks and must use
129	 * the READ_ONCE/WRITE_ONCE access
130	 */
131	short aborted;
132	bool adding_csums;
133	bool allocating_chunk;
134	bool can_flush_pending_bgs;
135	bool reloc_reserved;
136	bool dirty;
137	struct btrfs_root *root;
138	struct btrfs_fs_info *fs_info;
139	struct list_head new_bgs;
140};
141
142/*
143 * The abort status can be changed between calls and is not protected by locks.
144 * This accepts btrfs_transaction and btrfs_trans_handle as types. Once it's
145 * set to a non-zero value it does not change, so the macro should be in checks
146 * but is not necessary for further reads of the value.
147 */
148#define TRANS_ABORTED(trans)		(unlikely(READ_ONCE((trans)->aborted)))
149
150struct btrfs_pending_snapshot {
151	struct dentry *dentry;
152	struct inode *dir;
153	struct btrfs_root *root;
154	struct btrfs_root_item *root_item;
155	struct btrfs_root *snap;
156	struct btrfs_qgroup_inherit *inherit;
157	struct btrfs_path *path;
158	/* block reservation for the operation */
159	struct btrfs_block_rsv block_rsv;
160	/* extra metadata reservation for relocation */
161	int error;
162	/* Preallocated anonymous block device number */
163	dev_t anon_dev;
164	bool readonly;
165	struct list_head list;
166};
167
168static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
169					      struct btrfs_inode *inode)
170{
171	spin_lock(&inode->lock);
172	inode->last_trans = trans->transaction->transid;
173	inode->last_sub_trans = inode->root->log_transid;
174	inode->last_log_commit = inode->last_sub_trans - 1;
175	spin_unlock(&inode->lock);
176}
177
178/*
179 * Make qgroup codes to skip given qgroupid, means the old/new_roots for
180 * qgroup won't contain the qgroupid in it.
181 */
182static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
183					 u64 qgroupid)
184{
185	struct btrfs_delayed_ref_root *delayed_refs;
186
187	delayed_refs = &trans->transaction->delayed_refs;
188	WARN_ON(delayed_refs->qgroup_to_skip);
189	delayed_refs->qgroup_to_skip = qgroupid;
190}
191
192static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
193{
194	struct btrfs_delayed_ref_root *delayed_refs;
195
196	delayed_refs = &trans->transaction->delayed_refs;
197	WARN_ON(!delayed_refs->qgroup_to_skip);
198	delayed_refs->qgroup_to_skip = 0;
199}
200
201int btrfs_end_transaction(struct btrfs_trans_handle *trans);
202struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
203						   unsigned int num_items);
204struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
205					struct btrfs_root *root,
206					unsigned int num_items);
207struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
208struct btrfs_trans_handle *btrfs_join_transaction_spacecache(struct btrfs_root *root);
209struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root);
210struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
211struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
212					struct btrfs_root *root);
213int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
214
215void btrfs_add_dead_root(struct btrfs_root *root);
216int btrfs_defrag_root(struct btrfs_root *root);
217int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root);
218int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
219int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
220				   int wait_for_unblock);
221int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
222int btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
223void btrfs_throttle(struct btrfs_fs_info *fs_info);
224int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
225				struct btrfs_root *root);
226int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
227				struct extent_io_tree *dirty_pages, int mark);
228int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark);
229int btrfs_transaction_blocked(struct btrfs_fs_info *info);
230int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
231void btrfs_put_transaction(struct btrfs_transaction *transaction);
232void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info);
233void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
234			    struct btrfs_root *root);
235void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans);
236
237#endif
238