2c5a6f6e5bb0904eecef07941f9ad76f3ba2f036
[muen/linux.git] / fs / btrfs / transaction.h
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_BLOCKED,
17         TRANS_STATE_COMMIT_START,
18         TRANS_STATE_COMMIT_DOING,
19         TRANS_STATE_UNBLOCKED,
20         TRANS_STATE_COMPLETED,
21         TRANS_STATE_MAX,
22 };
23
24 #define BTRFS_TRANS_HAVE_FREE_BGS       0
25 #define BTRFS_TRANS_DIRTY_BG_RUN        1
26 #define BTRFS_TRANS_CACHE_ENOSPC        2
27
28 struct btrfs_transaction {
29         u64 transid;
30         /*
31          * total external writers(USERSPACE/START/ATTACH) in this
32          * transaction, it must be zero before the transaction is
33          * being committed
34          */
35         atomic_t num_extwriters;
36         /*
37          * total writers in this transaction, it must be zero before the
38          * transaction can end
39          */
40         atomic_t num_writers;
41         refcount_t use_count;
42
43         unsigned long flags;
44
45         /* Be protected by fs_info->trans_lock when we want to change it. */
46         enum btrfs_trans_state state;
47         int aborted;
48         struct list_head list;
49         struct extent_io_tree dirty_pages;
50         time64_t start_time;
51         wait_queue_head_t writer_wait;
52         wait_queue_head_t commit_wait;
53         struct list_head pending_snapshots;
54         struct list_head dev_update_list;
55         struct list_head switch_commits;
56         struct list_head dirty_bgs;
57
58         /*
59          * There is no explicit lock which protects io_bgs, rather its
60          * consistency is implied by the fact that all the sites which modify
61          * it do so under some form of transaction critical section, namely:
62          *
63          * - btrfs_start_dirty_block_groups - This function can only ever be
64          *   run by one of the transaction committers. Refer to
65          *   BTRFS_TRANS_DIRTY_BG_RUN usage in btrfs_commit_transaction
66          *
67          * - btrfs_write_dirty_blockgroups - this is called by
68          *   commit_cowonly_roots from transaction critical section
69          *   (TRANS_STATE_COMMIT_DOING)
70          *
71          * - btrfs_cleanup_dirty_bgs - called on transaction abort
72          */
73         struct list_head io_bgs;
74         struct list_head dropped_roots;
75
76         /*
77          * we need to make sure block group deletion doesn't race with
78          * free space cache writeout.  This mutex keeps them from stomping
79          * on each other
80          */
81         struct mutex cache_write_mutex;
82         spinlock_t dirty_bgs_lock;
83         /* Protected by spin lock fs_info->unused_bgs_lock. */
84         struct list_head deleted_bgs;
85         spinlock_t dropped_roots_lock;
86         struct btrfs_delayed_ref_root delayed_refs;
87         struct btrfs_fs_info *fs_info;
88 };
89
90 #define __TRANS_FREEZABLE       (1U << 0)
91
92 #define __TRANS_START           (1U << 9)
93 #define __TRANS_ATTACH          (1U << 10)
94 #define __TRANS_JOIN            (1U << 11)
95 #define __TRANS_JOIN_NOLOCK     (1U << 12)
96 #define __TRANS_DUMMY           (1U << 13)
97 #define __TRANS_JOIN_NOSTART    (1U << 14)
98
99 #define TRANS_START             (__TRANS_START | __TRANS_FREEZABLE)
100 #define TRANS_ATTACH            (__TRANS_ATTACH)
101 #define TRANS_JOIN              (__TRANS_JOIN | __TRANS_FREEZABLE)
102 #define TRANS_JOIN_NOLOCK       (__TRANS_JOIN_NOLOCK)
103 #define TRANS_JOIN_NOSTART      (__TRANS_JOIN_NOSTART)
104
105 #define TRANS_EXTWRITERS        (__TRANS_START | __TRANS_ATTACH)
106
107 #define BTRFS_SEND_TRANS_STUB   ((void *)1)
108
109 struct btrfs_trans_handle {
110         u64 transid;
111         u64 bytes_reserved;
112         u64 chunk_bytes_reserved;
113         unsigned long delayed_ref_updates;
114         struct btrfs_transaction *transaction;
115         struct btrfs_block_rsv *block_rsv;
116         struct btrfs_block_rsv *orig_rsv;
117         refcount_t use_count;
118         unsigned int type;
119         short aborted;
120         bool adding_csums;
121         bool allocating_chunk;
122         bool can_flush_pending_bgs;
123         bool reloc_reserved;
124         bool dirty;
125         struct btrfs_root *root;
126         struct btrfs_fs_info *fs_info;
127         struct list_head new_bgs;
128 };
129
130 struct btrfs_pending_snapshot {
131         struct dentry *dentry;
132         struct inode *dir;
133         struct btrfs_root *root;
134         struct btrfs_root_item *root_item;
135         struct btrfs_root *snap;
136         struct btrfs_qgroup_inherit *inherit;
137         struct btrfs_path *path;
138         /* block reservation for the operation */
139         struct btrfs_block_rsv block_rsv;
140         /* extra metadata reservation for relocation */
141         int error;
142         bool readonly;
143         struct list_head list;
144 };
145
146 static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
147                                               struct inode *inode)
148 {
149         spin_lock(&BTRFS_I(inode)->lock);
150         BTRFS_I(inode)->last_trans = trans->transaction->transid;
151         BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
152         BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
153         spin_unlock(&BTRFS_I(inode)->lock);
154 }
155
156 /*
157  * Make qgroup codes to skip given qgroupid, means the old/new_roots for
158  * qgroup won't contain the qgroupid in it.
159  */
160 static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
161                                          u64 qgroupid)
162 {
163         struct btrfs_delayed_ref_root *delayed_refs;
164
165         delayed_refs = &trans->transaction->delayed_refs;
166         WARN_ON(delayed_refs->qgroup_to_skip);
167         delayed_refs->qgroup_to_skip = qgroupid;
168 }
169
170 static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
171 {
172         struct btrfs_delayed_ref_root *delayed_refs;
173
174         delayed_refs = &trans->transaction->delayed_refs;
175         WARN_ON(!delayed_refs->qgroup_to_skip);
176         delayed_refs->qgroup_to_skip = 0;
177 }
178
179 int btrfs_end_transaction(struct btrfs_trans_handle *trans);
180 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
181                                                    unsigned int num_items);
182 struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
183                                         struct btrfs_root *root,
184                                         unsigned int num_items,
185                                         int min_factor);
186 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
187 struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root);
188 struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root);
189 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
190 struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
191                                         struct btrfs_root *root);
192 int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
193
194 void btrfs_add_dead_root(struct btrfs_root *root);
195 int btrfs_defrag_root(struct btrfs_root *root);
196 int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root);
197 int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
198 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
199                                    int wait_for_unblock);
200
201 /*
202  * Try to commit transaction asynchronously, so this is safe to call
203  * even holding a spinlock.
204  *
205  * It's done by informing transaction_kthread to commit transaction without
206  * waiting for commit interval.
207  */
208 static inline void btrfs_commit_transaction_locksafe(
209                 struct btrfs_fs_info *fs_info)
210 {
211         set_bit(BTRFS_FS_NEED_ASYNC_COMMIT, &fs_info->flags);
212         wake_up_process(fs_info->transaction_kthread);
213 }
214 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
215 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
216 void btrfs_throttle(struct btrfs_fs_info *fs_info);
217 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
218                                 struct btrfs_root *root);
219 int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
220                                 struct extent_io_tree *dirty_pages, int mark);
221 int btrfs_wait_extents(struct btrfs_fs_info *fs_info,
222                        struct extent_io_tree *dirty_pages);
223 int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark);
224 int btrfs_transaction_blocked(struct btrfs_fs_info *info);
225 int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
226 void btrfs_put_transaction(struct btrfs_transaction *transaction);
227 void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info);
228 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
229                             struct btrfs_root *root);
230 void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans);
231
232 #endif