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
  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
 103 #define TRANS_EXTWRITERS        (__TRANS_START | __TRANS_ATTACH)
 104
 105 #define BTRFS_SEND_TRANS_STUB   ((void *)1)
 106
 107 struct btrfs_trans_handle {
 108         u64 transid;
 109         u64 bytes_reserved;
 110         u64 chunk_bytes_reserved;
 111         unsigned long delayed_ref_updates;
 112         struct btrfs_transaction *transaction;
 113         struct btrfs_block_rsv *block_rsv;
 114         struct btrfs_block_rsv *orig_rsv;
 115         refcount_t use_count;
 116         unsigned int type;
 117         short aborted;
 118         bool adding_csums;
 119         bool allocating_chunk;
 120         bool can_flush_pending_bgs;
 121         bool reloc_reserved;
 122         bool dirty;
 123         struct btrfs_root *root;
 124         struct btrfs_fs_info *fs_info;
 125         struct list_head new_bgs;
 126 };
 127
 128 struct btrfs_pending_snapshot {
 129         struct dentry *dentry;
 130         struct inode *dir;
 131         struct btrfs_root *root;
 132         struct btrfs_root_item *root_item;
 133         struct btrfs_root *snap;
 134         struct btrfs_qgroup_inherit *inherit;
 135         struct btrfs_path *path;
 136         /* block reservation for the operation */
 137         struct btrfs_block_rsv block_rsv;
 138         /* extra metadata reservation for relocation */
 139         int error;
 140         bool readonly;
 141         struct list_head list;
 142 };
 143
 144 static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
 145                                               struct inode *inode)
 146 {
 147         spin_lock(&BTRFS_I(inode)->lock);
 148         BTRFS_I(inode)->last_trans = trans->transaction->transid;
 149         BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
 150         BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
 151         spin_unlock(&BTRFS_I(inode)->lock);
 152 }
 153
 154 /*
 155  * Make qgroup codes to skip given qgroupid, means the old/new_roots for
 156  * qgroup won't contain the qgroupid in it.
 157  */
 158 static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
 159                                          u64 qgroupid)
 160 {
 161         struct btrfs_delayed_ref_root *delayed_refs;
 162
 163         delayed_refs = &trans->transaction->delayed_refs;
 164         WARN_ON(delayed_refs->qgroup_to_skip);
 165         delayed_refs->qgroup_to_skip = qgroupid;
 166 }
 167
 168 static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
 169 {
 170         struct btrfs_delayed_ref_root *delayed_refs;
 171
 172         delayed_refs = &trans->transaction->delayed_refs;
 173         WARN_ON(!delayed_refs->qgroup_to_skip);
 174         delayed_refs->qgroup_to_skip = 0;
 175 }
 176
 177 int btrfs_end_transaction(struct btrfs_trans_handle *trans);
 178 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
 179                                                    unsigned int num_items);
 180 struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
 181                                         struct btrfs_root *root,
 182                                         unsigned int num_items,
 183                                         int min_factor);
 184 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
 185 struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root);
 186 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
 187 struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
 188                                         struct btrfs_root *root);
 189 int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
 190
 191 void btrfs_add_dead_root(struct btrfs_root *root);
 192 int btrfs_defrag_root(struct btrfs_root *root);
 193 int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root);
 194 int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
 195 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
 196                                    int wait_for_unblock);
 197
 198 /*
 199  * Try to commit transaction asynchronously, so this is safe to call
 200  * even holding a spinlock.
 201  *
 202  * It's done by informing transaction_kthread to commit transaction without
 203  * waiting for commit interval.
 204  */
 205 static inline void btrfs_commit_transaction_locksafe(
 206                 struct btrfs_fs_info *fs_info)
 207 {
 208         set_bit(BTRFS_FS_NEED_ASYNC_COMMIT, &fs_info->flags);
 209         wake_up_process(fs_info->transaction_kthread);
 210 }
 211 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
 212 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
 213 void btrfs_throttle(struct btrfs_fs_info *fs_info);
 214 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
 215                                 struct btrfs_root *root);
 216 int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
 217                                 struct extent_io_tree *dirty_pages, int mark);
 218 int btrfs_wait_extents(struct btrfs_fs_info *fs_info,
 219                        struct extent_io_tree *dirty_pages);
 220 int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark);
 221 int btrfs_transaction_blocked(struct btrfs_fs_info *info);
 222 int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
 223 void btrfs_put_transaction(struct btrfs_transaction *transaction);
 224 void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info);
 225 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
 226                             struct btrfs_root *root);
 227
 228 #endif