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_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
  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         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
 118 struct 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         /* Set by a task that wants to create a snapshot. */
 127         struct btrfs_pending_snapshot *pending_snapshot;
 128         refcount_t use_count;
 129         unsigned int type;
 130         /*
 131          * Error code of transaction abort, set outside of locks and must use
 132          * the READ_ONCE/WRITE_ONCE access
 133          */
 134         short aborted;
 135         bool adding_csums;
 136         bool allocating_chunk;
 137         bool removing_chunk;
 138         bool reloc_reserved;
 139         bool in_fsync;
 140         struct btrfs_root *root;
 141         struct btrfs_fs_info *fs_info;
 142         struct list_head new_bgs;
 143 };
 144
 145 /*
 146  * The abort status can be changed between calls and is not protected by locks.
 147  * This accepts btrfs_transaction and btrfs_trans_handle as types. Once it's
 148  * set to a non-zero value it does not change, so the macro should be in checks
 149  * but is not necessary for further reads of the value.
 150  */
 151 #define TRANS_ABORTED(trans)            (unlikely(READ_ONCE((trans)->aborted)))
 152
 153 struct btrfs_pending_snapshot {
 154         struct dentry *dentry;
 155         struct inode *dir;
 156         struct btrfs_root *root;
 157         struct btrfs_root_item *root_item;
 158         struct btrfs_root *snap;
 159         struct btrfs_qgroup_inherit *inherit;
 160         struct btrfs_path *path;
 161         /* block reservation for the operation */
 162         struct btrfs_block_rsv block_rsv;
 163         /* extra metadata reservation for relocation */
 164         int error;
 165         /* Preallocated anonymous block device number */
 166         dev_t anon_dev;
 167         bool readonly;
 168         struct list_head list;
 169 };
 170
 171 static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
 172                                               struct btrfs_inode *inode)
 173 {
 174         spin_lock(&inode->lock);
 175         inode->last_trans = trans->transaction->transid;
 176         inode->last_sub_trans = inode->root->log_transid;
 177         inode->last_log_commit = inode->last_sub_trans - 1;
 178         spin_unlock(&inode->lock);
 179 }
 180
 181 /*
 182  * Make qgroup codes to skip given qgroupid, means the old/new_roots for
 183  * qgroup won't contain the qgroupid in it.
 184  */
 185 static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
 186                                          u64 qgroupid)
 187 {
 188         struct btrfs_delayed_ref_root *delayed_refs;
 189
 190         delayed_refs = &trans->transaction->delayed_refs;
 191         WARN_ON(delayed_refs->qgroup_to_skip);
 192         delayed_refs->qgroup_to_skip = qgroupid;
 193 }
 194
 195 static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
 196 {
 197         struct btrfs_delayed_ref_root *delayed_refs;
 198
 199         delayed_refs = &trans->transaction->delayed_refs;
 200         WARN_ON(!delayed_refs->qgroup_to_skip);
 201         delayed_refs->qgroup_to_skip = 0;
 202 }
 203
 204 int btrfs_end_transaction(struct btrfs_trans_handle *trans);
 205 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
 206                                                    unsigned int num_items);
 207 struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
 208                                         struct btrfs_root *root,
 209                                         unsigned int num_items);
 210 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
 211 struct btrfs_trans_handle *btrfs_join_transaction_spacecache(struct btrfs_root *root);
 212 struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root);
 213 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
 214 struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
 215                                         struct btrfs_root *root);
 216 int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
 217
 218 void btrfs_add_dead_root(struct btrfs_root *root);
 219 int btrfs_defrag_root(struct btrfs_root *root);
 220 void btrfs_maybe_wake_unfinished_drop(struct btrfs_fs_info *fs_info);
 221 int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root);
 222 int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
 223 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans);
 224 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
 225 bool btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
 226 void btrfs_throttle(struct btrfs_fs_info *fs_info);
 227 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
 228                                 struct btrfs_root *root);
 229 int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
 230                                 struct extent_io_tree *dirty_pages, int mark);
 231 int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark);
 232 int btrfs_transaction_blocked(struct btrfs_fs_info *info);
 233 int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
 234 void btrfs_put_transaction(struct btrfs_transaction *transaction);
 235 void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info);
 236 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
 237                             struct btrfs_root *root);
 238 void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans);
 239
 240 #endif