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/atomic.h>
10#include <linux/refcount.h>
11#include <linux/list.h>
12#include <linux/time64.h>
13#include <linux/mutex.h>
14#include <linux/wait.h>
15#include "btrfs_inode.h"
16#include "delayed-ref.h"
17#include "extent-io-tree.h"
18#include "block-rsv.h"
19#include "messages.h"
20#include "misc.h"
21
22struct dentry;
23struct inode;
24struct btrfs_pending_snapshot;
25struct btrfs_fs_info;
26struct btrfs_root_item;
27struct btrfs_root;
28struct btrfs_path;
29
30/* Radix-tree tag for roots that are part of the trasaction. */
31#define BTRFS_ROOT_TRANS_TAG 0
32
33enum btrfs_trans_state {
34 TRANS_STATE_RUNNING,
35 TRANS_STATE_COMMIT_PREP,
36 TRANS_STATE_COMMIT_START,
37 TRANS_STATE_COMMIT_DOING,
38 TRANS_STATE_UNBLOCKED,
39 TRANS_STATE_SUPER_COMMITTED,
40 TRANS_STATE_COMPLETED,
41 TRANS_STATE_MAX,
42};
43
44#define BTRFS_TRANS_HAVE_FREE_BGS 0
45#define BTRFS_TRANS_DIRTY_BG_RUN 1
46#define BTRFS_TRANS_CACHE_ENOSPC 2
47
48struct btrfs_transaction {
49 u64 transid;
50 /*
51 * total external writers(USERSPACE/START/ATTACH) in this
52 * transaction, it must be zero before the transaction is
53 * being committed
54 */
55 atomic_t num_extwriters;
56 /*
57 * total writers in this transaction, it must be zero before the
58 * transaction can end
59 */
60 atomic_t num_writers;
61 refcount_t use_count;
62
63 unsigned long flags;
64
65 /* Be protected by fs_info->trans_lock when we want to change it. */
66 enum btrfs_trans_state state;
67 int aborted;
68 struct list_head list;
69 struct extent_io_tree dirty_pages;
70 time64_t start_time;
71 wait_queue_head_t writer_wait;
72 wait_queue_head_t commit_wait;
73 struct list_head pending_snapshots;
74 struct list_head dev_update_list;
75 struct list_head switch_commits;
76 struct list_head dirty_bgs;
77
78 /*
79 * There is no explicit lock which protects io_bgs, rather its
80 * consistency is implied by the fact that all the sites which modify
81 * it do so under some form of transaction critical section, namely:
82 *
83 * - btrfs_start_dirty_block_groups - This function can only ever be
84 * run by one of the transaction committers. Refer to
85 * BTRFS_TRANS_DIRTY_BG_RUN usage in btrfs_commit_transaction
86 *
87 * - btrfs_write_dirty_blockgroups - this is called by
88 * commit_cowonly_roots from transaction critical section
89 * (TRANS_STATE_COMMIT_DOING)
90 *
91 * - btrfs_cleanup_dirty_bgs - called on transaction abort
92 */
93 struct list_head io_bgs;
94 struct list_head dropped_roots;
95 struct extent_io_tree pinned_extents;
96
97 /*
98 * we need to make sure block group deletion doesn't race with
99 * free space cache writeout. This mutex keeps them from stomping
100 * on each other
101 */
102 struct mutex cache_write_mutex;
103 spinlock_t dirty_bgs_lock;
104 /* Protected by spin lock fs_info->unused_bgs_lock. */
105 struct list_head deleted_bgs;
106 spinlock_t dropped_roots_lock;
107 struct btrfs_delayed_ref_root delayed_refs;
108 struct btrfs_fs_info *fs_info;
109
110 /*
111 * Number of ordered extents the transaction must wait for before
112 * committing. These are ordered extents started by a fast fsync.
113 */
114 atomic_t pending_ordered;
115 wait_queue_head_t pending_wait;
116};
117
118enum {
119 ENUM_BIT(__TRANS_FREEZABLE),
120 ENUM_BIT(__TRANS_START),
121 ENUM_BIT(__TRANS_ATTACH),
122 ENUM_BIT(__TRANS_JOIN),
123 ENUM_BIT(__TRANS_JOIN_NOLOCK),
124 ENUM_BIT(__TRANS_DUMMY),
125 ENUM_BIT(__TRANS_JOIN_NOSTART),
126};
127
128#define TRANS_START (__TRANS_START | __TRANS_FREEZABLE)
129#define TRANS_ATTACH (__TRANS_ATTACH)
130#define TRANS_JOIN (__TRANS_JOIN | __TRANS_FREEZABLE)
131#define TRANS_JOIN_NOLOCK (__TRANS_JOIN_NOLOCK)
132#define TRANS_JOIN_NOSTART (__TRANS_JOIN_NOSTART)
133
134#define TRANS_EXTWRITERS (__TRANS_START | __TRANS_ATTACH)
135
136struct btrfs_trans_handle {
137 u64 transid;
138 u64 bytes_reserved;
139 u64 delayed_refs_bytes_reserved;
140 u64 chunk_bytes_reserved;
141 unsigned long delayed_ref_updates;
142 unsigned long delayed_ref_csum_deletions;
143 struct btrfs_transaction *transaction;
144 struct btrfs_block_rsv *block_rsv;
145 struct btrfs_block_rsv *orig_rsv;
146 /* Set by a task that wants to create a snapshot. */
147 struct btrfs_pending_snapshot *pending_snapshot;
148 refcount_t use_count;
149 unsigned int type;
150 /*
151 * Error code of transaction abort, set outside of locks and must use
152 * the READ_ONCE/WRITE_ONCE access
153 */
154 short aborted;
155 bool adding_csums;
156 bool allocating_chunk;
157 bool removing_chunk;
158 bool reloc_reserved;
159 bool in_fsync;
160 struct btrfs_fs_info *fs_info;
161 struct list_head new_bgs;
162 struct btrfs_block_rsv delayed_rsv;
163};
164
165/*
166 * The abort status can be changed between calls and is not protected by locks.
167 * This accepts btrfs_transaction and btrfs_trans_handle as types. Once it's
168 * set to a non-zero value it does not change, so the macro should be in checks
169 * but is not necessary for further reads of the value.
170 */
171#define TRANS_ABORTED(trans) (unlikely(READ_ONCE((trans)->aborted)))
172
173struct btrfs_pending_snapshot {
174 struct dentry *dentry;
175 struct inode *dir;
176 struct btrfs_root *root;
177 struct btrfs_root_item *root_item;
178 struct btrfs_root *snap;
179 struct btrfs_qgroup_inherit *inherit;
180 struct btrfs_path *path;
181 /* block reservation for the operation */
182 struct btrfs_block_rsv block_rsv;
183 /* extra metadata reservation for relocation */
184 int error;
185 /* Preallocated anonymous block device number */
186 dev_t anon_dev;
187 bool readonly;
188 struct list_head list;
189};
190
191static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
192 struct btrfs_inode *inode)
193{
194 spin_lock(lock: &inode->lock);
195 inode->last_trans = trans->transaction->transid;
196 inode->last_sub_trans = btrfs_get_root_log_transid(root: inode->root);
197 inode->last_log_commit = inode->last_sub_trans - 1;
198 spin_unlock(lock: &inode->lock);
199}
200
201/*
202 * Make qgroup codes to skip given qgroupid, means the old/new_roots for
203 * qgroup won't contain the qgroupid in it.
204 */
205static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
206 u64 qgroupid)
207{
208 struct btrfs_delayed_ref_root *delayed_refs;
209
210 delayed_refs = &trans->transaction->delayed_refs;
211 WARN_ON(delayed_refs->qgroup_to_skip);
212 delayed_refs->qgroup_to_skip = qgroupid;
213}
214
215static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
216{
217 struct btrfs_delayed_ref_root *delayed_refs;
218
219 delayed_refs = &trans->transaction->delayed_refs;
220 WARN_ON(!delayed_refs->qgroup_to_skip);
221 delayed_refs->qgroup_to_skip = 0;
222}
223
224bool __cold abort_should_print_stack(int error);
225
226/*
227 * Call btrfs_abort_transaction as early as possible when an error condition is
228 * detected, that way the exact stack trace is reported for some errors.
229 */
230#define btrfs_abort_transaction(trans, error) \
231do { \
232 bool first = false; \
233 /* Report first abort since mount */ \
234 if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED, \
235 &((trans)->fs_info->fs_state))) { \
236 first = true; \
237 if (WARN(abort_should_print_stack(error), \
238 KERN_ERR \
239 "BTRFS: Transaction aborted (error %d)\n", \
240 (error))) { \
241 /* Stack trace printed. */ \
242 } else { \
243 btrfs_err((trans)->fs_info, \
244 "Transaction aborted (error %d)", \
245 (error)); \
246 } \
247 } \
248 __btrfs_abort_transaction((trans), __func__, \
249 __LINE__, (error), first); \
250} while (0)
251
252int btrfs_end_transaction(struct btrfs_trans_handle *trans);
253struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
254 unsigned int num_items);
255struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
256 struct btrfs_root *root,
257 unsigned int num_items);
258struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
259struct btrfs_trans_handle *btrfs_join_transaction_spacecache(struct btrfs_root *root);
260struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root);
261struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
262struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
263 struct btrfs_root *root);
264int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
265
266void btrfs_add_dead_root(struct btrfs_root *root);
267void btrfs_maybe_wake_unfinished_drop(struct btrfs_fs_info *fs_info);
268int btrfs_clean_one_deleted_snapshot(struct btrfs_fs_info *fs_info);
269int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
270void btrfs_commit_transaction_async(struct btrfs_trans_handle *trans);
271int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
272bool btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
273void btrfs_throttle(struct btrfs_fs_info *fs_info);
274int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
275 struct btrfs_root *root);
276int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
277 struct extent_io_tree *dirty_pages, int mark);
278int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark);
279int btrfs_transaction_blocked(struct btrfs_fs_info *info);
280void btrfs_put_transaction(struct btrfs_transaction *transaction);
281void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
282 struct btrfs_root *root);
283void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans);
284void __cold __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
285 const char *function,
286 unsigned int line, int error, bool first_hit);
287
288int __init btrfs_transaction_init(void);
289void __cold btrfs_transaction_exit(void);
290
291#endif
292

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