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_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         struct extent_io_tree pinned_extents;
  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         /*
 120          * Error code of transaction abort, set outside of locks and must use
 121          * the READ_ONCE/WRITE_ONCE access
 122          */
 123         short aborted;
 124         bool adding_csums;
 125         bool allocating_chunk;
 126         bool can_flush_pending_bgs;
 127         bool reloc_reserved;
 128         bool dirty;
 129         struct btrfs_root *root;
 130         struct btrfs_fs_info *fs_info;
 131         struct list_head new_bgs;
 132 };
 133
 134 /*
 135  * The abort status can be changed between calls and is not protected by locks.
 136  * This accepts btrfs_transaction and btrfs_trans_handle as types. Once it's
 137  * set to a non-zero value it does not change, so the macro should be in checks
 138  * but is not necessary for further reads of the value.
 139  */
 140 #define TRANS_ABORTED(trans)            (unlikely(READ_ONCE((trans)->aborted)))
 141
 142 struct btrfs_pending_snapshot {
 143         struct dentry *dentry;
 144         struct inode *dir;
 145         struct btrfs_root *root;
 146         struct btrfs_root_item *root_item;
 147         struct btrfs_root *snap;
 148         struct btrfs_qgroup_inherit *inherit;
 149         struct btrfs_path *path;
 150         /* block reservation for the operation */
 151         struct btrfs_block_rsv block_rsv;
 152         /* extra metadata reservation for relocation */
 153         int error;
 154         bool readonly;
 155         struct list_head list;
 156 };
 157
 158 static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
 159                                               struct inode *inode)
 160 {
 161         spin_lock(&BTRFS_I(inode)->lock);
 162         BTRFS_I(inode)->last_trans = trans->transaction->transid;
 163         BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
 164         BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
 165         spin_unlock(&BTRFS_I(inode)->lock);
 166 }
 167
 168 /*
 169  * Make qgroup codes to skip given qgroupid, means the old/new_roots for
 170  * qgroup won't contain the qgroupid in it.
 171  */
 172 static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
 173                                          u64 qgroupid)
 174 {
 175         struct btrfs_delayed_ref_root *delayed_refs;
 176
 177         delayed_refs = &trans->transaction->delayed_refs;
 178         WARN_ON(delayed_refs->qgroup_to_skip);
 179         delayed_refs->qgroup_to_skip = qgroupid;
 180 }
 181
 182 static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
 183 {
 184         struct btrfs_delayed_ref_root *delayed_refs;
 185
 186         delayed_refs = &trans->transaction->delayed_refs;
 187         WARN_ON(!delayed_refs->qgroup_to_skip);
 188         delayed_refs->qgroup_to_skip = 0;
 189 }
 190
 191 int btrfs_end_transaction(struct btrfs_trans_handle *trans);
 192 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
 193                                                    unsigned int num_items);
 194 struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
 195                                         struct btrfs_root *root,
 196                                         unsigned int num_items);
 197 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
 198 struct btrfs_trans_handle *btrfs_join_transaction_spacecache(struct btrfs_root *root);
 199 struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root);
 200 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
 201 struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
 202                                         struct btrfs_root *root);
 203 int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
 204
 205 void btrfs_add_dead_root(struct btrfs_root *root);
 206 int btrfs_defrag_root(struct btrfs_root *root);
 207 int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root);
 208 int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
 209 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
 210                                    int wait_for_unblock);
 211
 212 /*
 213  * Try to commit transaction asynchronously, so this is safe to call
 214  * even holding a spinlock.
 215  *
 216  * It's done by informing transaction_kthread to commit transaction without
 217  * waiting for commit interval.
 218  */
 219 static inline void btrfs_commit_transaction_locksafe(
 220                 struct btrfs_fs_info *fs_info)
 221 {
 222         set_bit(BTRFS_FS_NEED_ASYNC_COMMIT, &fs_info->flags);
 223         wake_up_process(fs_info->transaction_kthread);
 224 }
 225 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
 226 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
 227 void btrfs_throttle(struct btrfs_fs_info *fs_info);
 228 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
 229                                 struct btrfs_root *root);
 230 int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
 231                                 struct extent_io_tree *dirty_pages, int mark);
 232 int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark);
 233 int btrfs_transaction_blocked(struct btrfs_fs_info *info);
 234 int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
 235 void btrfs_put_transaction(struct btrfs_transaction *transaction);
 236 void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info);
 237 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
 238                             struct btrfs_root *root);
 239 void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans);
 240
 241 #endif