2762c8d6191c55c45ea35271d616f1863f3d2e96
[sfrench/cifs-2.6.git] / fs / btrfs / transaction.h
1 /*
2  * Copyright (C) 2007 Oracle.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public
6  * License v2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public
14  * License along with this program; if not, write to the
15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16  * Boston, MA 021110-1307, USA.
17  */
18
19 #ifndef __BTRFS_TRANSACTION__
20 #define __BTRFS_TRANSACTION__
21
22 #include <linux/refcount.h>
23 #include "btrfs_inode.h"
24 #include "delayed-ref.h"
25 #include "ctree.h"
26
27 enum btrfs_trans_state {
28         TRANS_STATE_RUNNING             = 0,
29         TRANS_STATE_BLOCKED             = 1,
30         TRANS_STATE_COMMIT_START        = 2,
31         TRANS_STATE_COMMIT_DOING        = 3,
32         TRANS_STATE_UNBLOCKED           = 4,
33         TRANS_STATE_COMPLETED           = 5,
34         TRANS_STATE_MAX                 = 6,
35 };
36
37 #define BTRFS_TRANS_HAVE_FREE_BGS       0
38 #define BTRFS_TRANS_DIRTY_BG_RUN        1
39 #define BTRFS_TRANS_CACHE_ENOSPC        2
40
41 struct btrfs_transaction {
42         u64 transid;
43         /*
44          * total external writers(USERSPACE/START/ATTACH) in this
45          * transaction, it must be zero before the transaction is
46          * being committed
47          */
48         atomic_t num_extwriters;
49         /*
50          * total writers in this transaction, it must be zero before the
51          * transaction can end
52          */
53         atomic_t num_writers;
54         refcount_t use_count;
55         atomic_t pending_ordered;
56
57         unsigned long flags;
58
59         /* Be protected by fs_info->trans_lock when we want to change it. */
60         enum btrfs_trans_state state;
61         int aborted;
62         struct list_head list;
63         struct extent_io_tree dirty_pages;
64         unsigned long start_time;
65         wait_queue_head_t writer_wait;
66         wait_queue_head_t commit_wait;
67         wait_queue_head_t pending_wait;
68         struct list_head pending_snapshots;
69         struct list_head pending_chunks;
70         struct list_head switch_commits;
71         struct list_head dirty_bgs;
72
73         /*
74          * There is no explicit lock which protects io_bgs, rather its
75          * consistency is implied by the fact that all the sites which modify
76          * it do so under some form of transaction critical section, namely:
77          *
78          * - btrfs_start_dirty_block_groups - This function can only ever be
79          *   run by one of the transaction committers. Refer to
80          *   BTRFS_TRANS_DIRTY_BG_RUN usage in btrfs_commit_transaction
81          *
82          * - btrfs_write_dirty_blockgroups - this is called by
83          *   commit_cowonly_roots from transaction critical section
84          *   (TRANS_STATE_COMMIT_DOING)
85          *
86          * - btrfs_cleanup_dirty_bgs - called on transaction abort
87          */
88         struct list_head io_bgs;
89         struct list_head dropped_roots;
90
91         /*
92          * we need to make sure block group deletion doesn't race with
93          * free space cache writeout.  This mutex keeps them from stomping
94          * on each other
95          */
96         struct mutex cache_write_mutex;
97         spinlock_t dirty_bgs_lock;
98         unsigned int num_dirty_bgs;
99         /* Protected by spin lock fs_info->unused_bgs_lock. */
100         struct list_head deleted_bgs;
101         spinlock_t dropped_roots_lock;
102         struct btrfs_delayed_ref_root delayed_refs;
103         struct btrfs_fs_info *fs_info;
104 };
105
106 #define __TRANS_FREEZABLE       (1U << 0)
107
108 #define __TRANS_USERSPACE       (1U << 8)
109 #define __TRANS_START           (1U << 9)
110 #define __TRANS_ATTACH          (1U << 10)
111 #define __TRANS_JOIN            (1U << 11)
112 #define __TRANS_JOIN_NOLOCK     (1U << 12)
113 #define __TRANS_DUMMY           (1U << 13)
114
115 #define TRANS_USERSPACE         (__TRANS_USERSPACE | __TRANS_FREEZABLE)
116 #define TRANS_START             (__TRANS_START | __TRANS_FREEZABLE)
117 #define TRANS_ATTACH            (__TRANS_ATTACH)
118 #define TRANS_JOIN              (__TRANS_JOIN | __TRANS_FREEZABLE)
119 #define TRANS_JOIN_NOLOCK       (__TRANS_JOIN_NOLOCK)
120
121 #define TRANS_EXTWRITERS        (__TRANS_USERSPACE | __TRANS_START |    \
122                                  __TRANS_ATTACH)
123
124 #define BTRFS_SEND_TRANS_STUB   ((void *)1)
125
126 struct btrfs_trans_handle {
127         u64 transid;
128         u64 bytes_reserved;
129         u64 chunk_bytes_reserved;
130         unsigned long delayed_ref_updates;
131         struct btrfs_transaction *transaction;
132         struct btrfs_block_rsv *block_rsv;
133         struct btrfs_block_rsv *orig_rsv;
134         refcount_t use_count;
135         unsigned int type;
136         short aborted;
137         bool adding_csums;
138         bool allocating_chunk;
139         bool can_flush_pending_bgs;
140         bool reloc_reserved;
141         bool sync;
142         bool dirty;
143         struct btrfs_root *root;
144         struct btrfs_fs_info *fs_info;
145         struct list_head new_bgs;
146 };
147
148 struct btrfs_pending_snapshot {
149         struct dentry *dentry;
150         struct inode *dir;
151         struct btrfs_root *root;
152         struct btrfs_root_item *root_item;
153         struct btrfs_root *snap;
154         struct btrfs_qgroup_inherit *inherit;
155         struct btrfs_path *path;
156         /* block reservation for the operation */
157         struct btrfs_block_rsv block_rsv;
158         u64 qgroup_reserved;
159         /* extra metadata reservation for relocation */
160         int error;
161         bool readonly;
162         struct list_head list;
163 };
164
165 static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
166                                               struct inode *inode)
167 {
168         spin_lock(&BTRFS_I(inode)->lock);
169         BTRFS_I(inode)->last_trans = trans->transaction->transid;
170         BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
171         BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
172         spin_unlock(&BTRFS_I(inode)->lock);
173 }
174
175 /*
176  * Make qgroup codes to skip given qgroupid, means the old/new_roots for
177  * qgroup won't contain the qgroupid in it.
178  */
179 static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
180                                          u64 qgroupid)
181 {
182         struct btrfs_delayed_ref_root *delayed_refs;
183
184         delayed_refs = &trans->transaction->delayed_refs;
185         WARN_ON(delayed_refs->qgroup_to_skip);
186         delayed_refs->qgroup_to_skip = qgroupid;
187 }
188
189 static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
190 {
191         struct btrfs_delayed_ref_root *delayed_refs;
192
193         delayed_refs = &trans->transaction->delayed_refs;
194         WARN_ON(!delayed_refs->qgroup_to_skip);
195         delayed_refs->qgroup_to_skip = 0;
196 }
197
198 int btrfs_end_transaction(struct btrfs_trans_handle *trans);
199 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
200                                                    unsigned int num_items);
201 struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
202                                         struct btrfs_root *root,
203                                         unsigned int num_items,
204                                         int min_factor);
205 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
206 struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root);
207 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
208 struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
209                                         struct btrfs_root *root);
210 struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *root);
211 int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
212
213 void btrfs_add_dead_root(struct btrfs_root *root);
214 int btrfs_defrag_root(struct btrfs_root *root);
215 int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root);
216 int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
217 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
218                                    int wait_for_unblock);
219 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
220 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
221 void btrfs_throttle(struct btrfs_fs_info *fs_info);
222 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
223                                 struct btrfs_root *root);
224 int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
225                                 struct extent_io_tree *dirty_pages, int mark);
226 int btrfs_wait_extents(struct btrfs_fs_info *fs_info,
227                        struct extent_io_tree *dirty_pages);
228 int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark);
229 int btrfs_transaction_blocked(struct btrfs_fs_info *info);
230 int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
231 void btrfs_put_transaction(struct btrfs_transaction *transaction);
232 void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info);
233 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
234                             struct btrfs_root *root);
235 #endif