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 /* Radix-tree tag for roots that are part of the trasaction. */
16 #define BTRFS_ROOT_TRANS_TAG 0
17
18 enum btrfs_trans_state {
19 TRANS_STATE_RUNNING,
20 TRANS_STATE_COMMIT_PREP,
21 TRANS_STATE_COMMIT_START,
22 TRANS_STATE_COMMIT_DOING,
23 TRANS_STATE_UNBLOCKED,
24 TRANS_STATE_SUPER_COMMITTED,
25 TRANS_STATE_COMPLETED,
26 TRANS_STATE_MAX,
27 };
28
29 #define BTRFS_TRANS_HAVE_FREE_BGS 0
30 #define BTRFS_TRANS_DIRTY_BG_RUN 1
31 #define BTRFS_TRANS_CACHE_ENOSPC 2
32
33 struct btrfs_transaction {
34 u64 transid;
35 /*
36 * total external writers(USERSPACE/START/ATTACH) in this
37 * transaction, it must be zero before the transaction is
38 * being committed
39 */
40 atomic_t num_extwriters;
41 /*
42 * total writers in this transaction, it must be zero before the
43 * transaction can end
44 */
45 atomic_t num_writers;
46 refcount_t use_count;
47
48 unsigned long flags;
49
50 /* Be protected by fs_info->trans_lock when we want to change it. */
51 enum btrfs_trans_state state;
52 int aborted;
53 struct list_head list;
54 struct extent_io_tree dirty_pages;
55 time64_t start_time;
56 wait_queue_head_t writer_wait;
57 wait_queue_head_t commit_wait;
58 struct list_head pending_snapshots;
59 struct list_head dev_update_list;
60 struct list_head switch_commits;
61 struct list_head dirty_bgs;
62
63 /*
64 * There is no explicit lock which protects io_bgs, rather its
65 * consistency is implied by the fact that all the sites which modify
66 * it do so under some form of transaction critical section, namely:
67 *
68 * - btrfs_start_dirty_block_groups - This function can only ever be
69 * run by one of the transaction committers. Refer to
70 * BTRFS_TRANS_DIRTY_BG_RUN usage in btrfs_commit_transaction
71 *
72 * - btrfs_write_dirty_blockgroups - this is called by
73 * commit_cowonly_roots from transaction critical section
74 * (TRANS_STATE_COMMIT_DOING)
75 *
76 * - btrfs_cleanup_dirty_bgs - called on transaction abort
77 */
78 struct list_head io_bgs;
79 struct list_head dropped_roots;
80 struct extent_io_tree pinned_extents;
81
82 /*
83 * we need to make sure block group deletion doesn't race with
84 * free space cache writeout. This mutex keeps them from stomping
85 * on each other
86 */
87 struct mutex cache_write_mutex;
88 spinlock_t dirty_bgs_lock;
89 /* Protected by spin lock fs_info->unused_bgs_lock. */
90 struct list_head deleted_bgs;
91 spinlock_t dropped_roots_lock;
92 struct btrfs_delayed_ref_root delayed_refs;
93 struct btrfs_fs_info *fs_info;
94
95 /*
96 * Number of ordered extents the transaction must wait for before
97 * committing. These are ordered extents started by a fast fsync.
98 */
99 atomic_t pending_ordered;
100 wait_queue_head_t pending_wait;
101 };
102
103 enum {
104 ENUM_BIT(__TRANS_FREEZABLE),
105 ENUM_BIT(__TRANS_START),
106 ENUM_BIT(__TRANS_ATTACH),
107 ENUM_BIT(__TRANS_JOIN),
108 ENUM_BIT(__TRANS_JOIN_NOLOCK),
109 ENUM_BIT(__TRANS_DUMMY),
110 ENUM_BIT(__TRANS_JOIN_NOSTART),
111 };
112
113 #define TRANS_START (__TRANS_START | __TRANS_FREEZABLE)
114 #define TRANS_ATTACH (__TRANS_ATTACH)
115 #define TRANS_JOIN (__TRANS_JOIN | __TRANS_FREEZABLE)
116 #define TRANS_JOIN_NOLOCK (__TRANS_JOIN_NOLOCK)
117 #define TRANS_JOIN_NOSTART (__TRANS_JOIN_NOSTART)
118
119 #define TRANS_EXTWRITERS (__TRANS_START | __TRANS_ATTACH)
120
121 struct btrfs_trans_handle {
122 u64 transid;
123 u64 bytes_reserved;
124 u64 chunk_bytes_reserved;
125 unsigned long delayed_ref_updates;
126 struct btrfs_transaction *transaction;
127 struct btrfs_block_rsv *block_rsv;
128 struct btrfs_block_rsv *orig_rsv;
129 /* Set by a task that wants to create a snapshot. */
130 struct btrfs_pending_snapshot *pending_snapshot;
131 refcount_t use_count;
132 unsigned int type;
133 /*
134 * Error code of transaction abort, set outside of locks and must use
135 * the READ_ONCE/WRITE_ONCE access
136 */
137 short aborted;
138 bool adding_csums;
139 bool allocating_chunk;
140 bool removing_chunk;
141 bool reloc_reserved;
142 bool in_fsync;
143 struct btrfs_fs_info *fs_info;
144 struct list_head new_bgs;
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
155 struct 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
btrfs_set_inode_last_trans(struct btrfs_trans_handle * trans,struct btrfs_inode * inode)173 static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
174 struct btrfs_inode *inode)
175 {
176 spin_lock(&inode->lock);
177 inode->last_trans = trans->transaction->transid;
178 inode->last_sub_trans = inode->root->log_transid;
179 inode->last_log_commit = inode->last_sub_trans - 1;
180 spin_unlock(&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 */
btrfs_set_skip_qgroup(struct btrfs_trans_handle * trans,u64 qgroupid)187 static 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
btrfs_clear_skip_qgroup(struct btrfs_trans_handle * trans)197 static 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
206 bool __cold abort_should_print_stack(int errno);
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, errno) \
213 do { \
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(errno), \
220 KERN_ERR \
221 "BTRFS: Transaction aborted (error %d)\n", \
222 (errno))) { \
223 /* Stack trace printed. */ \
224 } else { \
225 btrfs_err((trans)->fs_info, \
226 "Transaction aborted (error %d)", \
227 (errno)); \
228 } \
229 } \
230 __btrfs_abort_transaction((trans), __func__, \
231 __LINE__, (errno), first); \
232 } while (0)
233
234 int btrfs_end_transaction(struct btrfs_trans_handle *trans);
235 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
236 unsigned int num_items);
237 struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
238 struct btrfs_root *root,
239 unsigned int num_items);
240 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
241 struct btrfs_trans_handle *btrfs_join_transaction_spacecache(struct btrfs_root *root);
242 struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root);
243 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
244 struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
245 struct btrfs_root *root);
246 int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
247
248 void btrfs_add_dead_root(struct btrfs_root *root);
249 int btrfs_defrag_root(struct btrfs_root *root);
250 void btrfs_maybe_wake_unfinished_drop(struct btrfs_fs_info *fs_info);
251 int btrfs_clean_one_deleted_snapshot(struct btrfs_fs_info *fs_info);
252 int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
253 void btrfs_commit_transaction_async(struct btrfs_trans_handle *trans);
254 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
255 bool btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
256 void btrfs_throttle(struct btrfs_fs_info *fs_info);
257 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
258 struct btrfs_root *root);
259 int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
260 struct extent_io_tree *dirty_pages, int mark);
261 int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark);
262 int btrfs_transaction_blocked(struct btrfs_fs_info *info);
263 int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
264 void btrfs_put_transaction(struct btrfs_transaction *transaction);
265 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
266 struct btrfs_root *root);
267 void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans);
268 void __cold __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
269 const char *function,
270 unsigned int line, int errno, bool first_hit);
271
272 int __init btrfs_transaction_init(void);
273 void __cold btrfs_transaction_exit(void);
274
275 #endif
276