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