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_PREP,
18 TRANS_STATE_COMMIT_START,
19 TRANS_STATE_COMMIT_DOING,
20 TRANS_STATE_UNBLOCKED,
21 TRANS_STATE_SUPER_COMMITTED,
22 TRANS_STATE_COMPLETED,
23 TRANS_STATE_MAX,
24};
25
26#define BTRFS_TRANS_HAVE_FREE_BGS 0
27#define BTRFS_TRANS_DIRTY_BG_RUN 1
28#define BTRFS_TRANS_CACHE_ENOSPC 2
29
30struct btrfs_transaction {
31 u64 transid;
32 /*
33 * total external writers(USERSPACE/START/ATTACH) in this
34 * transaction, it must be zero before the transaction is
35 * being committed
36 */
37 atomic_t num_extwriters;
38 /*
39 * total writers in this transaction, it must be zero before the
40 * transaction can end
41 */
42 atomic_t num_writers;
43 refcount_t use_count;
44
45 unsigned long flags;
46
47 /* Be protected by fs_info->trans_lock when we want to change it. */
48 enum btrfs_trans_state state;
49 int aborted;
50 struct list_head list;
51 struct extent_io_tree dirty_pages;
52 time64_t start_time;
53 wait_queue_head_t writer_wait;
54 wait_queue_head_t commit_wait;
55 struct list_head pending_snapshots;
56 struct list_head dev_update_list;
57 struct list_head switch_commits;
58 struct list_head dirty_bgs;
59
60 /*
61 * There is no explicit lock which protects io_bgs, rather its
62 * consistency is implied by the fact that all the sites which modify
63 * it do so under some form of transaction critical section, namely:
64 *
65 * - btrfs_start_dirty_block_groups - This function can only ever be
66 * run by one of the transaction committers. Refer to
67 * BTRFS_TRANS_DIRTY_BG_RUN usage in btrfs_commit_transaction
68 *
69 * - btrfs_write_dirty_blockgroups - this is called by
70 * commit_cowonly_roots from transaction critical section
71 * (TRANS_STATE_COMMIT_DOING)
72 *
73 * - btrfs_cleanup_dirty_bgs - called on transaction abort
74 */
75 struct list_head io_bgs;
76 struct list_head dropped_roots;
77 struct extent_io_tree pinned_extents;
78
79 /*
80 * we need to make sure block group deletion doesn't race with
81 * free space cache writeout. This mutex keeps them from stomping
82 * on each other
83 */
84 struct mutex cache_write_mutex;
85 spinlock_t dirty_bgs_lock;
86 /* Protected by spin lock fs_info->unused_bgs_lock. */
87 struct list_head deleted_bgs;
88 spinlock_t dropped_roots_lock;
89 struct btrfs_delayed_ref_root delayed_refs;
90 struct btrfs_fs_info *fs_info;
91
92 /*
93 * Number of ordered extents the transaction must wait for before
94 * committing. These are ordered extents started by a fast fsync.
95 */
96 atomic_t pending_ordered;
97 wait_queue_head_t pending_wait;
98};
99
100enum {
101 ENUM_BIT(__TRANS_FREEZABLE),
102 ENUM_BIT(__TRANS_START),
103 ENUM_BIT(__TRANS_ATTACH),
104 ENUM_BIT(__TRANS_JOIN),
105 ENUM_BIT(__TRANS_JOIN_NOLOCK),
106 ENUM_BIT(__TRANS_DUMMY),
107 ENUM_BIT(__TRANS_JOIN_NOSTART),
108};
109
110#define TRANS_START (__TRANS_START | __TRANS_FREEZABLE)
111#define TRANS_ATTACH (__TRANS_ATTACH)
112#define TRANS_JOIN (__TRANS_JOIN | __TRANS_FREEZABLE)
113#define TRANS_JOIN_NOLOCK (__TRANS_JOIN_NOLOCK)
114#define TRANS_JOIN_NOSTART (__TRANS_JOIN_NOSTART)
115
116#define TRANS_EXTWRITERS (__TRANS_START | __TRANS_ATTACH)
117
118struct btrfs_trans_handle {
119 u64 transid;
120 u64 bytes_reserved;
121 u64 delayed_refs_bytes_reserved;
122 u64 chunk_bytes_reserved;
123 unsigned long delayed_ref_updates;
124 unsigned long delayed_ref_csum_deletions;
125 struct btrfs_transaction *transaction;
126 struct btrfs_block_rsv *block_rsv;
127 struct btrfs_block_rsv *orig_rsv;
128 /* Set by a task that wants to create a snapshot. */
129 struct btrfs_pending_snapshot *pending_snapshot;
130 refcount_t use_count;
131 unsigned int type;
132 /*
133 * Error code of transaction abort, set outside of locks and must use
134 * the READ_ONCE/WRITE_ONCE access
135 */
136 short aborted;
137 bool adding_csums;
138 bool allocating_chunk;
139 bool removing_chunk;
140 bool reloc_reserved;
141 bool in_fsync;
142 struct btrfs_fs_info *fs_info;
143 struct list_head new_bgs;
144 struct btrfs_block_rsv delayed_rsv;
145};
146
147/*
148 * The abort status can be changed between calls and is not protected by locks.
149 * This accepts btrfs_transaction and btrfs_trans_handle as types. Once it's
150 * set to a non-zero value it does not change, so the macro should be in checks
151 * but is not necessary for further reads of the value.
152 */
153#define TRANS_ABORTED(trans) (unlikely(READ_ONCE((trans)->aborted)))
154
155struct btrfs_pending_snapshot {
156 struct dentry *dentry;
157 struct inode *dir;
158 struct btrfs_root *root;
159 struct btrfs_root_item *root_item;
160 struct btrfs_root *snap;
161 struct btrfs_qgroup_inherit *inherit;
162 struct btrfs_path *path;
163 /* block reservation for the operation */
164 struct btrfs_block_rsv block_rsv;
165 /* extra metadata reservation for relocation */
166 int error;
167 /* Preallocated anonymous block device number */
168 dev_t anon_dev;
169 bool readonly;
170 struct list_head list;
171};
172
173static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
174 struct btrfs_inode *inode)
175{
176 spin_lock(lock: &inode->lock);
177 inode->last_trans = trans->transaction->transid;
178 inode->last_sub_trans = btrfs_get_root_log_transid(root: inode->root);
179 inode->last_log_commit = inode->last_sub_trans - 1;
180 spin_unlock(lock: &inode->lock);
181}
182
183/*
184 * Make qgroup codes to skip given qgroupid, means the old/new_roots for
185 * qgroup won't contain the qgroupid in it.
186 */
187static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
188 u64 qgroupid)
189{
190 struct btrfs_delayed_ref_root *delayed_refs;
191
192 delayed_refs = &trans->transaction->delayed_refs;
193 WARN_ON(delayed_refs->qgroup_to_skip);
194 delayed_refs->qgroup_to_skip = qgroupid;
195}
196
197static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
198{
199 struct btrfs_delayed_ref_root *delayed_refs;
200
201 delayed_refs = &trans->transaction->delayed_refs;
202 WARN_ON(!delayed_refs->qgroup_to_skip);
203 delayed_refs->qgroup_to_skip = 0;
204}
205
206bool __cold abort_should_print_stack(int error);
207
208/*
209 * Call btrfs_abort_transaction as early as possible when an error condition is
210 * detected, that way the exact stack trace is reported for some errors.
211 */
212#define btrfs_abort_transaction(trans, error) \
213do { \
214 bool first = false; \
215 /* Report first abort since mount */ \
216 if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED, \
217 &((trans)->fs_info->fs_state))) { \
218 first = true; \
219 if (WARN(abort_should_print_stack(error), \
220 KERN_ERR \
221 "BTRFS: Transaction aborted (error %d)\n", \
222 (error))) { \
223 /* Stack trace printed. */ \
224 } else { \
225 btrfs_err((trans)->fs_info, \
226 "Transaction aborted (error %d)", \
227 (error)); \
228 } \
229 } \
230 __btrfs_abort_transaction((trans), __func__, \
231 __LINE__, (error), first); \
232} while (0)
233
234int btrfs_end_transaction(struct btrfs_trans_handle *trans);
235struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
236 unsigned int num_items);
237struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
238 struct btrfs_root *root,
239 unsigned int num_items);
240struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
241struct btrfs_trans_handle *btrfs_join_transaction_spacecache(struct btrfs_root *root);
242struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root);
243struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
244struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
245 struct btrfs_root *root);
246int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
247
248void btrfs_add_dead_root(struct btrfs_root *root);
249void btrfs_maybe_wake_unfinished_drop(struct btrfs_fs_info *fs_info);
250int btrfs_clean_one_deleted_snapshot(struct btrfs_fs_info *fs_info);
251int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
252void btrfs_commit_transaction_async(struct btrfs_trans_handle *trans);
253int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
254bool btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
255void btrfs_throttle(struct btrfs_fs_info *fs_info);
256int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
257 struct btrfs_root *root);
258int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
259 struct extent_io_tree *dirty_pages, int mark);
260int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark);
261int btrfs_transaction_blocked(struct btrfs_fs_info *info);
262int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
263void btrfs_put_transaction(struct btrfs_transaction *transaction);
264void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
265 struct btrfs_root *root);
266void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans);
267void __cold __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
268 const char *function,
269 unsigned int line, int error, bool first_hit);
270
271int __init btrfs_transaction_init(void);
272void __cold btrfs_transaction_exit(void);
273
274#endif
275

source code of linux/fs/btrfs/transaction.h