LXR linux/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
  14enum btrfs_trans_state {
  15        TRANS_STATE_RUNNING,
  16        TRANS_STATE_COMMIT_START,
  17        TRANS_STATE_COMMIT_DOING,
  18        TRANS_STATE_UNBLOCKED,
  19        TRANS_STATE_SUPER_COMMITTED,
  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
  28struct 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        struct extent_io_tree pinned_extents;
  76
  77        /*
  78         * we need to make sure block group deletion doesn't race with
  79         * free space cache writeout.  This mutex keeps them from stomping
  80         * on each other
  81         */
  82        struct mutex cache_write_mutex;
  83        spinlock_t dirty_bgs_lock;
  84        /* Protected by spin lock fs_info->unused_bgs_lock. */
  85        struct list_head deleted_bgs;
  86        spinlock_t dropped_roots_lock;
  87        struct btrfs_delayed_ref_root delayed_refs;
  88        struct btrfs_fs_info *fs_info;
  89
  90        /*
  91         * Number of ordered extents the transaction must wait for before
  92         * committing. These are ordered extents started by a fast fsync.
  93         */
  94        atomic_t pending_ordered;
  95        wait_queue_head_t pending_wait;
  96
  97        spinlock_t releasing_ebs_lock;
  98        struct list_head releasing_ebs;
  99};
 100
 101#define __TRANS_FREEZABLE       (1U << 0)
 102
 103#define __TRANS_START           (1U << 9)
 104#define __TRANS_ATTACH          (1U << 10)
 105#define __TRANS_JOIN            (1U << 11)
 106#define __TRANS_JOIN_NOLOCK     (1U << 12)
 107#define __TRANS_DUMMY           (1U << 13)
 108#define __TRANS_JOIN_NOSTART    (1U << 14)
 109
 110#define TRANS_START             (__TRANS_START | __TRANS_FREEZABLE)
 111#define TRANS_ATTACH            (__TRANS_ATTACH)
 112#define TRANS_JOIN              (__TRANS_JOIN | __TRANS_FREEZABLE)
 113#define TRANS_JOIN_NOLOCK       (__TRANS_JOIN_NOLOCK)
 114#define TRANS_JOIN_NOSTART      (__TRANS_JOIN_NOSTART)
 115
 116#define TRANS_EXTWRITERS        (__TRANS_START | __TRANS_ATTACH)
 117
 118struct btrfs_trans_handle {
 119        u64 transid;
 120        u64 bytes_reserved;
 121        u64 chunk_bytes_reserved;
 122        unsigned long delayed_ref_updates;
 123        struct btrfs_transaction *transaction;
 124        struct btrfs_block_rsv *block_rsv;
 125        struct btrfs_block_rsv *orig_rsv;
 126        refcount_t use_count;
 127        unsigned int type;
 128        /*
 129         * Error code of transaction abort, set outside of locks and must use
 130         * the READ_ONCE/WRITE_ONCE access
 131         */
 132        short aborted;
 133        bool adding_csums;
 134        bool allocating_chunk;
 135        bool removing_chunk;
 136        bool reloc_reserved;
 137        bool in_fsync;
 138        struct btrfs_root *root;
 139        struct btrfs_fs_info *fs_info;
 140        struct list_head new_bgs;
 141};
 142
 143/*
 144 * The abort status can be changed between calls and is not protected by locks.
 145 * This accepts btrfs_transaction and btrfs_trans_handle as types. Once it's
 146 * set to a non-zero value it does not change, so the macro should be in checks
 147 * but is not necessary for further reads of the value.
 148 */
 149#define TRANS_ABORTED(trans)            (unlikely(READ_ONCE((trans)->aborted)))
 150
 151struct btrfs_pending_snapshot {
 152        struct dentry *dentry;
 153        struct inode *dir;
 154        struct btrfs_root *root;
 155        struct btrfs_root_item *root_item;
 156        struct btrfs_root *snap;
 157        struct btrfs_qgroup_inherit *inherit;
 158        struct btrfs_path *path;
 159        /* block reservation for the operation */
 160        struct btrfs_block_rsv block_rsv;
 161        /* extra metadata reservation for relocation */
 162        int error;
 163        /* Preallocated anonymous block device number */
 164        dev_t anon_dev;
 165        bool readonly;
 166        struct list_head list;
 167};
 168
 169static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
 170                                              struct btrfs_inode *inode)
 171{
 172        spin_lock(&inode->lock);
 173        inode->last_trans = trans->transaction->transid;
 174        inode->last_sub_trans = inode->root->log_transid;
 175        inode->last_log_commit = inode->last_sub_trans - 1;
 176        spin_unlock(&inode->lock);
 177}
 178
 179/*
 180 * Make qgroup codes to skip given qgroupid, means the old/new_roots for
 181 * qgroup won't contain the qgroupid in it.
 182 */
 183static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
 184                                         u64 qgroupid)
 185{
 186        struct btrfs_delayed_ref_root *delayed_refs;
 187
 188        delayed_refs = &trans->transaction->delayed_refs;
 189        WARN_ON(delayed_refs->qgroup_to_skip);
 190        delayed_refs->qgroup_to_skip = qgroupid;
 191}
 192
 193static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
 194{
 195        struct btrfs_delayed_ref_root *delayed_refs;
 196
 197        delayed_refs = &trans->transaction->delayed_refs;
 198        WARN_ON(!delayed_refs->qgroup_to_skip);
 199        delayed_refs->qgroup_to_skip = 0;
 200}
 201
 202int btrfs_end_transaction(struct btrfs_trans_handle *trans);
 203struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
 204                                                   unsigned int num_items);
 205struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
 206                                        struct btrfs_root *root,
 207                                        unsigned int num_items);
 208struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
 209struct btrfs_trans_handle *btrfs_join_transaction_spacecache(struct btrfs_root *root);
 210struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root);
 211struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
 212struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
 213                                        struct btrfs_root *root);
 214int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
 215
 216void btrfs_add_dead_root(struct btrfs_root *root);
 217int btrfs_defrag_root(struct btrfs_root *root);
 218int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root);
 219int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
 220int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans);
 221int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
 222bool btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
 223void btrfs_throttle(struct btrfs_fs_info *fs_info);
 224int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
 225                                struct btrfs_root *root);
 226int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
 227                                struct extent_io_tree *dirty_pages, int mark);
 228int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark);
 229int btrfs_transaction_blocked(struct btrfs_fs_info *info);
 230int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
 231void btrfs_put_transaction(struct btrfs_transaction *transaction);
 232void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info);
 233void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
 234                            struct btrfs_root *root);
 235void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans);
 236
 237#endif
 238