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             = 0,
  16         TRANS_STATE_BLOCKED             = 1,
  17         TRANS_STATE_COMMIT_START        = 2,
  18         TRANS_STATE_COMMIT_DOING        = 3,
  19         TRANS_STATE_UNBLOCKED           = 4,
  20         TRANS_STATE_COMPLETED           = 5,
  21         TRANS_STATE_MAX                 = 6,
  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         atomic_t pending_ordered;
  43
  44         unsigned long flags;
  45
  46         /* Be protected by fs_info->trans_lock when we want to change it. */
  47         enum btrfs_trans_state state;
  48         int aborted;
  49         struct list_head list;
  50         struct extent_io_tree dirty_pages;
  51         time64_t start_time;
  52         wait_queue_head_t writer_wait;
  53         wait_queue_head_t commit_wait;
  54         wait_queue_head_t pending_wait;
  55         struct list_head pending_snapshots;
  56         struct list_head pending_chunks;
  57         struct list_head switch_commits;
  58         struct list_head dirty_bgs;
  59
  60         /*
  61          * There is no explicit lock which protects io_bgs, rather its
  62          * consistency is implied by the fact that all the sites which modify
  63          * it do so under some form of transaction critical section, namely:
  64          *
  65          * - btrfs_start_dirty_block_groups - This function can only ever be
  66          *   run by one of the transaction committers. Refer to
  67          *   BTRFS_TRANS_DIRTY_BG_RUN usage in btrfs_commit_transaction
  68          *
  69          * - btrfs_write_dirty_blockgroups - this is called by
  70          *   commit_cowonly_roots from transaction critical section
  71          *   (TRANS_STATE_COMMIT_DOING)
  72          *
  73          * - btrfs_cleanup_dirty_bgs - called on transaction abort
  74          */
  75         struct list_head io_bgs;
  76         struct list_head dropped_roots;
  77
  78         /*
  79          * we need to make sure block group deletion doesn't race with
  80          * free space cache writeout.  This mutex keeps them from stomping
  81          * on each other
  82          */
  83         struct mutex cache_write_mutex;
  84         spinlock_t dirty_bgs_lock;
  85         unsigned int num_dirty_bgs;
  86         /* Protected by spin lock fs_info->unused_bgs_lock. */
  87         struct list_head deleted_bgs;
  88         spinlock_t dropped_roots_lock;
  89         struct btrfs_delayed_ref_root delayed_refs;
  90         struct btrfs_fs_info *fs_info;
  91 };
  92
  93 #define __TRANS_FREEZABLE       (1U << 0)
  94
  95 #define __TRANS_START           (1U << 9)
  96 #define __TRANS_ATTACH          (1U << 10)
  97 #define __TRANS_JOIN            (1U << 11)
  98 #define __TRANS_JOIN_NOLOCK     (1U << 12)
  99 #define __TRANS_DUMMY           (1U << 13)
 100 #define __TRANS_JOIN_NOSTART    (1U << 14)
 101
 102 #define TRANS_START             (__TRANS_START | __TRANS_FREEZABLE)
 103 #define TRANS_ATTACH            (__TRANS_ATTACH)
 104 #define TRANS_JOIN              (__TRANS_JOIN | __TRANS_FREEZABLE)
 105 #define TRANS_JOIN_NOLOCK       (__TRANS_JOIN_NOLOCK)
 106 #define TRANS_JOIN_NOSTART      (__TRANS_JOIN_NOSTART)
 107
 108 #define TRANS_EXTWRITERS        (__TRANS_START | __TRANS_ATTACH)
 109
 110 #define BTRFS_SEND_TRANS_STUB   ((void *)1)
 111
 112 struct btrfs_trans_handle {
 113         u64 transid;
 114         u64 bytes_reserved;
 115         u64 chunk_bytes_reserved;
 116         unsigned long delayed_ref_updates;
 117         struct btrfs_transaction *transaction;
 118         struct btrfs_block_rsv *block_rsv;
 119         struct btrfs_block_rsv *orig_rsv;
 120         refcount_t use_count;
 121         unsigned int type;
 122         short aborted;
 123         bool adding_csums;
 124         bool allocating_chunk;
 125         bool can_flush_pending_bgs;
 126         bool reloc_reserved;
 127         bool sync;
 128         bool dirty;
 129         struct btrfs_root *root;
 130         struct btrfs_fs_info *fs_info;
 131         struct list_head new_bgs;
 132 };
 133
 134 struct btrfs_pending_snapshot {
 135         struct dentry *dentry;
 136         struct inode *dir;
 137         struct btrfs_root *root;
 138         struct btrfs_root_item *root_item;
 139         struct btrfs_root *snap;
 140         struct btrfs_qgroup_inherit *inherit;
 141         struct btrfs_path *path;
 142         /* block reservation for the operation */
 143         struct btrfs_block_rsv block_rsv;
 144         /* extra metadata reservation for relocation */
 145         int error;
 146         bool readonly;
 147         struct list_head list;
 148 };
 149
 150 static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
 151                                               struct inode *inode)
 152 {
 153         spin_lock(&BTRFS_I(inode)->lock);
 154         BTRFS_I(inode)->last_trans = trans->transaction->transid;
 155         BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
 156         BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
 157         spin_unlock(&BTRFS_I(inode)->lock);
 158 }
 159
 160 /*
 161  * Make qgroup codes to skip given qgroupid, means the old/new_roots for
 162  * qgroup won't contain the qgroupid in it.
 163  */
 164 static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
 165                                          u64 qgroupid)
 166 {
 167         struct btrfs_delayed_ref_root *delayed_refs;
 168
 169         delayed_refs = &trans->transaction->delayed_refs;
 170         WARN_ON(delayed_refs->qgroup_to_skip);
 171         delayed_refs->qgroup_to_skip = qgroupid;
 172 }
 173
 174 static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
 175 {
 176         struct btrfs_delayed_ref_root *delayed_refs;
 177
 178         delayed_refs = &trans->transaction->delayed_refs;
 179         WARN_ON(!delayed_refs->qgroup_to_skip);
 180         delayed_refs->qgroup_to_skip = 0;
 181 }
 182
 183 int btrfs_end_transaction(struct btrfs_trans_handle *trans);
 184 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
 185                                                    unsigned int num_items);
 186 struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
 187                                         struct btrfs_root *root,
 188                                         unsigned int num_items,
 189                                         int min_factor);
 190 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
 191 struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root);
 192 struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root);
 193 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
 194 struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
 195                                         struct btrfs_root *root);
 196 int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
 197
 198 void btrfs_add_dead_root(struct btrfs_root *root);
 199 int btrfs_defrag_root(struct btrfs_root *root);
 200 int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root);
 201 int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
 202 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
 203                                    int wait_for_unblock);
 204
 205 /*
 206  * Try to commit transaction asynchronously, so this is safe to call
 207  * even holding a spinlock.
 208  *
 209  * It's done by informing transaction_kthread to commit transaction without
 210  * waiting for commit interval.
 211  */
 212 static inline void btrfs_commit_transaction_locksafe(
 213                 struct btrfs_fs_info *fs_info)
 214 {
 215         set_bit(BTRFS_FS_NEED_ASYNC_COMMIT, &fs_info->flags);
 216         wake_up_process(fs_info->transaction_kthread);
 217 }
 218 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
 219 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
 220 void btrfs_throttle(struct btrfs_fs_info *fs_info);
 221 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
 222                                 struct btrfs_root *root);
 223 int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
 224                                 struct extent_io_tree *dirty_pages, int mark);
 225 int btrfs_wait_extents(struct btrfs_fs_info *fs_info,
 226                        struct extent_io_tree *dirty_pages);
 227 int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark);
 228 int btrfs_transaction_blocked(struct btrfs_fs_info *info);
 229 int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
 230 void btrfs_put_transaction(struct btrfs_transaction *transaction);
 231 void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info);
 232 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
 233                             struct btrfs_root *root);
 234
 235 #endif