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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#include "misc.h"
14
15enum btrfs_trans_state {
16 TRANS_STATE_RUNNING,
17 TRANS_STATE_COMMIT_START,
18 TRANS_STATE_COMMIT_DOING,
19 TRANS_STATE_UNBLOCKED,
20 TRANS_STATE_SUPER_COMMITTED,
21 TRANS_STATE_COMPLETED,
22 TRANS_STATE_MAX,
23};
24
25#define BTRFS_TRANS_HAVE_FREE_BGS 0
26#define BTRFS_TRANS_DIRTY_BG_RUN 1
27#define BTRFS_TRANS_CACHE_ENOSPC 2
28
29struct btrfs_transaction {
30 u64 transid;
31 /*
32 * total external writers(USERSPACE/START/ATTACH) in this
33 * transaction, it must be zero before the transaction is
34 * being committed
35 */
36 atomic_t num_extwriters;
37 /*
38 * total writers in this transaction, it must be zero before the
39 * transaction can end
40 */
41 atomic_t num_writers;
42 refcount_t use_count;
43
44 unsigned long flags;
45
46 /* Be protected by fs_info->trans_lock when we want to change it. */
47 enum btrfs_trans_state state;
48 int aborted;
49 struct list_head list;
50 struct extent_io_tree dirty_pages;
51 time64_t start_time;
52 wait_queue_head_t writer_wait;
53 wait_queue_head_t commit_wait;
54 struct list_head pending_snapshots;
55 struct list_head dev_update_list;
56 struct list_head switch_commits;
57 struct list_head dirty_bgs;
58
59 /*
60 * There is no explicit lock which protects io_bgs, rather its
61 * consistency is implied by the fact that all the sites which modify
62 * it do so under some form of transaction critical section, namely:
63 *
64 * - btrfs_start_dirty_block_groups - This function can only ever be
65 * run by one of the transaction committers. Refer to
66 * BTRFS_TRANS_DIRTY_BG_RUN usage in btrfs_commit_transaction
67 *
68 * - btrfs_write_dirty_blockgroups - this is called by
69 * commit_cowonly_roots from transaction critical section
70 * (TRANS_STATE_COMMIT_DOING)
71 *
72 * - btrfs_cleanup_dirty_bgs - called on transaction abort
73 */
74 struct list_head io_bgs;
75 struct list_head dropped_roots;
76 struct extent_io_tree pinned_extents;
77
78 /*
79 * we need to make sure block group deletion doesn't race with
80 * free space cache writeout. This mutex keeps them from stomping
81 * on each other
82 */
83 struct mutex cache_write_mutex;
84 spinlock_t dirty_bgs_lock;
85 /* Protected by spin lock fs_info->unused_bgs_lock. */
86 struct list_head deleted_bgs;
87 spinlock_t dropped_roots_lock;
88 struct btrfs_delayed_ref_root delayed_refs;
89 struct btrfs_fs_info *fs_info;
90
91 /*
92 * Number of ordered extents the transaction must wait for before
93 * committing. These are ordered extents started by a fast fsync.
94 */
95 atomic_t pending_ordered;
96 wait_queue_head_t pending_wait;
97};
98
99enum {
100 ENUM_BIT(__TRANS_FREEZABLE),
101 ENUM_BIT(__TRANS_START),
102 ENUM_BIT(__TRANS_ATTACH),
103 ENUM_BIT(__TRANS_JOIN),
104 ENUM_BIT(__TRANS_JOIN_NOLOCK),
105 ENUM_BIT(__TRANS_DUMMY),
106 ENUM_BIT(__TRANS_JOIN_NOSTART),
107};
108
109#define TRANS_START (__TRANS_START | __TRANS_FREEZABLE)
110#define TRANS_ATTACH (__TRANS_ATTACH)
111#define TRANS_JOIN (__TRANS_JOIN | __TRANS_FREEZABLE)
112#define TRANS_JOIN_NOLOCK (__TRANS_JOIN_NOLOCK)
113#define TRANS_JOIN_NOSTART (__TRANS_JOIN_NOSTART)
114
115#define TRANS_EXTWRITERS (__TRANS_START | __TRANS_ATTACH)
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 /* Set by a task that wants to create a snapshot. */
126 struct btrfs_pending_snapshot *pending_snapshot;
127 refcount_t use_count;
128 unsigned int type;
129 /*
130 * Error code of transaction abort, set outside of locks and must use
131 * the READ_ONCE/WRITE_ONCE access
132 */
133 short aborted;
134 bool adding_csums;
135 bool allocating_chunk;
136 bool removing_chunk;
137 bool reloc_reserved;
138 bool in_fsync;
139 struct btrfs_fs_info *fs_info;
140 struct list_head new_bgs;
141};
142
143/*
144 * The abort status can be changed between calls and is not protected by locks.
145 * This accepts btrfs_transaction and btrfs_trans_handle as types. Once it's
146 * set to a non-zero value it does not change, so the macro should be in checks
147 * but is not necessary for further reads of the value.
148 */
149#define TRANS_ABORTED(trans) (unlikely(READ_ONCE((trans)->aborted)))
150
151struct btrfs_pending_snapshot {
152 struct dentry *dentry;
153 struct inode *dir;
154 struct btrfs_root *root;
155 struct btrfs_root_item *root_item;
156 struct btrfs_root *snap;
157 struct btrfs_qgroup_inherit *inherit;
158 struct btrfs_path *path;
159 /* block reservation for the operation */
160 struct btrfs_block_rsv block_rsv;
161 /* extra metadata reservation for relocation */
162 int error;
163 /* Preallocated anonymous block device number */
164 dev_t anon_dev;
165 bool readonly;
166 struct list_head list;
167};
168
169static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
170 struct btrfs_inode *inode)
171{
172 spin_lock(&inode->lock);
173 inode->last_trans = trans->transaction->transid;
174 inode->last_sub_trans = inode->root->log_transid;
175 inode->last_log_commit = inode->last_sub_trans - 1;
176 spin_unlock(&inode->lock);
177}
178
179/*
180 * Make qgroup codes to skip given qgroupid, means the old/new_roots for
181 * qgroup won't contain the qgroupid in it.
182 */
183static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
184 u64 qgroupid)
185{
186 struct btrfs_delayed_ref_root *delayed_refs;
187
188 delayed_refs = &trans->transaction->delayed_refs;
189 WARN_ON(delayed_refs->qgroup_to_skip);
190 delayed_refs->qgroup_to_skip = qgroupid;
191}
192
193static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
194{
195 struct btrfs_delayed_ref_root *delayed_refs;
196
197 delayed_refs = &trans->transaction->delayed_refs;
198 WARN_ON(!delayed_refs->qgroup_to_skip);
199 delayed_refs->qgroup_to_skip = 0;
200}
201
202bool __cold abort_should_print_stack(int errno);
203
204/*
205 * Call btrfs_abort_transaction as early as possible when an error condition is
206 * detected, that way the exact stack trace is reported for some errors.
207 */
208#define btrfs_abort_transaction(trans, errno) \
209do { \
210 bool first = false; \
211 /* Report first abort since mount */ \
212 if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED, \
213 &((trans)->fs_info->fs_state))) { \
214 first = true; \
215 if (WARN(abort_should_print_stack(errno), \
216 KERN_ERR \
217 "BTRFS: Transaction aborted (error %d)\n", \
218 (errno))) { \
219 /* Stack trace printed. */ \
220 } else { \
221 btrfs_debug((trans)->fs_info, \
222 "Transaction aborted (error %d)", \
223 (errno)); \
224 } \
225 } \
226 __btrfs_abort_transaction((trans), __func__, \
227 __LINE__, (errno), first); \
228} while (0)
229
230int btrfs_end_transaction(struct btrfs_trans_handle *trans);
231struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
232 unsigned int num_items);
233struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
234 struct btrfs_root *root,
235 unsigned int num_items);
236struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
237struct btrfs_trans_handle *btrfs_join_transaction_spacecache(struct btrfs_root *root);
238struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root);
239struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
240struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
241 struct btrfs_root *root);
242int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
243
244void btrfs_add_dead_root(struct btrfs_root *root);
245int btrfs_defrag_root(struct btrfs_root *root);
246void btrfs_maybe_wake_unfinished_drop(struct btrfs_fs_info *fs_info);
247int btrfs_clean_one_deleted_snapshot(struct btrfs_fs_info *fs_info);
248int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
249void btrfs_commit_transaction_async(struct btrfs_trans_handle *trans);
250int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
251bool btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
252void btrfs_throttle(struct btrfs_fs_info *fs_info);
253int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
254 struct btrfs_root *root);
255int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
256 struct extent_io_tree *dirty_pages, int mark);
257int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark);
258int btrfs_transaction_blocked(struct btrfs_fs_info *info);
259int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
260void btrfs_put_transaction(struct btrfs_transaction *transaction);
261void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
262 struct btrfs_root *root);
263void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans);
264void __cold __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
265 const char *function,
266 unsigned int line, int errno, bool first_hit);
267
268int __init btrfs_transaction_init(void);
269void __cold btrfs_transaction_exit(void);
270
271#endif