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
14 enum btrfs_trans_state {
15 TRANS_STATE_RUNNING,
16 TRANS_STATE_COMMIT_START,
17 TRANS_STATE_COMMIT_DOING,
18 TRANS_STATE_UNBLOCKED,
19 TRANS_STATE_COMPLETED,
20 TRANS_STATE_MAX,
21 };
22
23 #define BTRFS_TRANS_HAVE_FREE_BGS 0
24 #define BTRFS_TRANS_DIRTY_BG_RUN 1
25 #define BTRFS_TRANS_CACHE_ENOSPC 2
26
27 struct btrfs_transaction {
28 u64 transid;
29 /*
30 * total external writers(USERSPACE/START/ATTACH) in this
31 * transaction, it must be zero before the transaction is
32 * being committed
33 */
34 atomic_t num_extwriters;
35 /*
36 * total writers in this transaction, it must be zero before the
37 * transaction can end
38 */
39 atomic_t num_writers;
40 refcount_t use_count;
41
42 unsigned long flags;
43
44 /* Be protected by fs_info->trans_lock when we want to change it. */
45 enum btrfs_trans_state state;
46 int aborted;
47 struct list_head list;
48 struct extent_io_tree dirty_pages;
49 time64_t start_time;
50 wait_queue_head_t writer_wait;
51 wait_queue_head_t commit_wait;
52 struct list_head pending_snapshots;
53 struct list_head dev_update_list;
54 struct list_head switch_commits;
55 struct list_head dirty_bgs;
56
57 /*
58 * There is no explicit lock which protects io_bgs, rather its
59 * consistency is implied by the fact that all the sites which modify
60 * it do so under some form of transaction critical section, namely:
61 *
62 * - btrfs_start_dirty_block_groups - This function can only ever be
63 * run by one of the transaction committers. Refer to
64 * BTRFS_TRANS_DIRTY_BG_RUN usage in btrfs_commit_transaction
65 *
66 * - btrfs_write_dirty_blockgroups - this is called by
67 * commit_cowonly_roots from transaction critical section
68 * (TRANS_STATE_COMMIT_DOING)
69 *
70 * - btrfs_cleanup_dirty_bgs - called on transaction abort
71 */
72 struct list_head io_bgs;
73 struct list_head dropped_roots;
74
75 /*
76 * we need to make sure block group deletion doesn't race with
77 * free space cache writeout. This mutex keeps them from stomping
78 * on each other
79 */
80 struct mutex cache_write_mutex;
81 spinlock_t dirty_bgs_lock;
82 /* Protected by spin lock fs_info->unused_bgs_lock. */
83 struct list_head deleted_bgs;
84 spinlock_t dropped_roots_lock;
85 struct btrfs_delayed_ref_root delayed_refs;
86 struct btrfs_fs_info *fs_info;
87 };
88
89 #define __TRANS_FREEZABLE (1U << 0)
90
91 #define __TRANS_START (1U << 9)
92 #define __TRANS_ATTACH (1U << 10)
93 #define __TRANS_JOIN (1U << 11)
94 #define __TRANS_JOIN_NOLOCK (1U << 12)
95 #define __TRANS_DUMMY (1U << 13)
96 #define __TRANS_JOIN_NOSTART (1U << 14)
97
98 #define TRANS_START (__TRANS_START | __TRANS_FREEZABLE)
99 #define TRANS_ATTACH (__TRANS_ATTACH)
100 #define TRANS_JOIN (__TRANS_JOIN | __TRANS_FREEZABLE)
101 #define TRANS_JOIN_NOLOCK (__TRANS_JOIN_NOLOCK)
102 #define TRANS_JOIN_NOSTART (__TRANS_JOIN_NOSTART)
103
104 #define TRANS_EXTWRITERS (__TRANS_START | __TRANS_ATTACH)
105
106 #define BTRFS_SEND_TRANS_STUB ((void *)1)
107
108 struct btrfs_trans_handle {
109 u64 transid;
110 u64 bytes_reserved;
111 u64 chunk_bytes_reserved;
112 unsigned long delayed_ref_updates;
113 struct btrfs_transaction *transaction;
114 struct btrfs_block_rsv *block_rsv;
115 struct btrfs_block_rsv *orig_rsv;
116 refcount_t use_count;
117 unsigned int type;
118 /*
119 * Error code of transaction abort, set outside of locks and must use
120 * the READ_ONCE/WRITE_ONCE access
121 */
122 short aborted;
123 bool adding_csums;
124 bool allocating_chunk;
125 bool can_flush_pending_bgs;
126 bool reloc_reserved;
127 bool dirty;
128 struct btrfs_root *root;
129 struct btrfs_fs_info *fs_info;
130 struct list_head new_bgs;
131 };
132
133 /*
134 * The abort status can be changed between calls and is not protected by locks.
135 * This accepts btrfs_transaction and btrfs_trans_handle as types. Once it's
136 * set to a non-zero value it does not change, so the macro should be in checks
137 * but is not necessary for further reads of the value.
138 */
139 #define TRANS_ABORTED(trans) (unlikely(READ_ONCE((trans)->aborted)))
140
141 struct btrfs_pending_snapshot {
142 struct dentry *dentry;
143 struct inode *dir;
144 struct btrfs_root *root;
145 struct btrfs_root_item *root_item;
146 struct btrfs_root *snap;
147 struct btrfs_qgroup_inherit *inherit;
148 struct btrfs_path *path;
149 /* block reservation for the operation */
150 struct btrfs_block_rsv block_rsv;
151 /* extra metadata reservation for relocation */
152 int error;
153 bool readonly;
154 struct list_head list;
155 };
156
btrfs_set_inode_last_trans(struct btrfs_trans_handle * trans,struct inode * inode)157 static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
158 struct inode *inode)
159 {
160 spin_lock(&BTRFS_I(inode)->lock);
161 BTRFS_I(inode)->last_trans = trans->transaction->transid;
162 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
163 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->last_sub_trans - 1;
164 spin_unlock(&BTRFS_I(inode)->lock);
165 }
166
167 /*
168 * Make qgroup codes to skip given qgroupid, means the old/new_roots for
169 * qgroup won't contain the qgroupid in it.
170 */
btrfs_set_skip_qgroup(struct btrfs_trans_handle * trans,u64 qgroupid)171 static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
172 u64 qgroupid)
173 {
174 struct btrfs_delayed_ref_root *delayed_refs;
175
176 delayed_refs = &trans->transaction->delayed_refs;
177 WARN_ON(delayed_refs->qgroup_to_skip);
178 delayed_refs->qgroup_to_skip = qgroupid;
179 }
180
btrfs_clear_skip_qgroup(struct btrfs_trans_handle * trans)181 static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
182 {
183 struct btrfs_delayed_ref_root *delayed_refs;
184
185 delayed_refs = &trans->transaction->delayed_refs;
186 WARN_ON(!delayed_refs->qgroup_to_skip);
187 delayed_refs->qgroup_to_skip = 0;
188 }
189
190 int btrfs_end_transaction(struct btrfs_trans_handle *trans);
191 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
192 unsigned int num_items);
193 struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
194 struct btrfs_root *root,
195 unsigned int num_items);
196 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
197 struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root);
198 struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root);
199 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
200 struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
201 struct btrfs_root *root);
202 int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
203
204 void btrfs_add_dead_root(struct btrfs_root *root);
205 int btrfs_defrag_root(struct btrfs_root *root);
206 int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root);
207 int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
208 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
209 int wait_for_unblock);
210 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
211 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
212 void btrfs_throttle(struct btrfs_fs_info *fs_info);
213 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
214 struct btrfs_root *root);
215 int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
216 struct extent_io_tree *dirty_pages, int mark);
217 int btrfs_wait_extents(struct btrfs_fs_info *fs_info,
218 struct extent_io_tree *dirty_pages);
219 int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark);
220 int btrfs_transaction_blocked(struct btrfs_fs_info *info);
221 int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
222 void btrfs_put_transaction(struct btrfs_transaction *transaction);
223 void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info);
224 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
225 struct btrfs_root *root);
226 void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans);
227
228 #endif
229