fs/btrfs/transaction.h

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #ifndef __BTRFS_TRANSACTION__
  20 #define __BTRFS_TRANSACTION__
  21
  22 #include <linux/refcount.h>
  23 #include "btrfs_inode.h"
  24 #include "delayed-ref.h"
  25 #include "ctree.h"
  26
  27 enum btrfs_trans_state {
  28         TRANS_STATE_RUNNING             = 0,
  29         TRANS_STATE_BLOCKED             = 1,
  30         TRANS_STATE_COMMIT_START        = 2,
  31         TRANS_STATE_COMMIT_DOING        = 3,
  32         TRANS_STATE_UNBLOCKED           = 4,
  33         TRANS_STATE_COMPLETED           = 5,
  34         TRANS_STATE_MAX                 = 6,
  35 };
  36
  37 #define BTRFS_TRANS_HAVE_FREE_BGS       0
  38 #define BTRFS_TRANS_DIRTY_BG_RUN        1
  39 #define BTRFS_TRANS_CACHE_ENOSPC        2
  40
  41 struct btrfs_transaction {
  42         u64 transid;
  43         /*
  44          * total external writers(USERSPACE/START/ATTACH) in this
  45          * transaction, it must be zero before the transaction is
  46          * being committed
  47          */
  48         atomic_t num_extwriters;
  49         /*
  50          * total writers in this transaction, it must be zero before the
  51          * transaction can end
  52          */
  53         atomic_t num_writers;
  54         refcount_t use_count;
  55         atomic_t pending_ordered;
  56
  57         unsigned long flags;
  58
  59         /* Be protected by fs_info->trans_lock when we want to change it. */
  60         enum btrfs_trans_state state;
  61         int aborted;
  62         struct list_head list;
  63         struct extent_io_tree dirty_pages;
  64         unsigned long start_time;
  65         wait_queue_head_t writer_wait;
  66         wait_queue_head_t commit_wait;
  67         wait_queue_head_t pending_wait;
  68         struct list_head pending_snapshots;
  69         struct list_head pending_chunks;
  70         struct list_head switch_commits;
  71         struct list_head dirty_bgs;
  72
  73         /*
  74          * There is no explicit lock which protects io_bgs, rather its
  75          * consistency is implied by the fact that all the sites which modify
  76          * it do so under some form of transaction critical section, namely:
  77          *
  78          * - btrfs_start_dirty_block_groups - This function can only ever be
  79          *   run by one of the transaction committers. Refer to
  80          *   BTRFS_TRANS_DIRTY_BG_RUN usage in btrfs_commit_transaction
  81          *
  82          * - btrfs_write_dirty_blockgroups - this is called by
  83          *   commit_cowonly_roots from transaction critical section
  84          *   (TRANS_STATE_COMMIT_DOING)
  85          *
  86          * - btrfs_cleanup_dirty_bgs - called on transaction abort
  87          */
  88         struct list_head io_bgs;
  89         struct list_head dropped_roots;
  90
  91         /*
  92          * we need to make sure block group deletion doesn't race with
  93          * free space cache writeout.  This mutex keeps them from stomping
  94          * on each other
  95          */
  96         struct mutex cache_write_mutex;
  97         spinlock_t dirty_bgs_lock;
  98         unsigned int num_dirty_bgs;
  99         /* Protected by spin lock fs_info->unused_bgs_lock. */
 100         struct list_head deleted_bgs;
 101         spinlock_t dropped_roots_lock;
 102         struct btrfs_delayed_ref_root delayed_refs;
 103         struct btrfs_fs_info *fs_info;
 104 };
 105
 106 #define __TRANS_FREEZABLE       (1U << 0)
 107
 108 #define __TRANS_START           (1U << 9)
 109 #define __TRANS_ATTACH          (1U << 10)
 110 #define __TRANS_JOIN            (1U << 11)
 111 #define __TRANS_JOIN_NOLOCK     (1U << 12)
 112 #define __TRANS_DUMMY           (1U << 13)
 113
 114 #define TRANS_START             (__TRANS_START | __TRANS_FREEZABLE)
 115 #define TRANS_ATTACH            (__TRANS_ATTACH)
 116 #define TRANS_JOIN              (__TRANS_JOIN | __TRANS_FREEZABLE)
 117 #define TRANS_JOIN_NOLOCK       (__TRANS_JOIN_NOLOCK)
 118
 119 #define TRANS_EXTWRITERS        (__TRANS_START | __TRANS_ATTACH)
 120
 121 #define BTRFS_SEND_TRANS_STUB   ((void *)1)
 122
 123 struct btrfs_trans_handle {
 124         u64 transid;
 125         u64 bytes_reserved;
 126         u64 chunk_bytes_reserved;
 127         unsigned long delayed_ref_updates;
 128         struct btrfs_transaction *transaction;
 129         struct btrfs_block_rsv *block_rsv;
 130         struct btrfs_block_rsv *orig_rsv;
 131         refcount_t use_count;
 132         unsigned int type;
 133         short aborted;
 134         bool adding_csums;
 135         bool allocating_chunk;
 136         bool can_flush_pending_bgs;
 137         bool reloc_reserved;
 138         bool sync;
 139         bool dirty;
 140         struct btrfs_root *root;
 141         struct btrfs_fs_info *fs_info;
 142         struct list_head new_bgs;
 143 };
 144
 145 struct btrfs_pending_snapshot {
 146         struct dentry *dentry;
 147         struct inode *dir;
 148         struct btrfs_root *root;
 149         struct btrfs_root_item *root_item;
 150         struct btrfs_root *snap;
 151         struct btrfs_qgroup_inherit *inherit;
 152         struct btrfs_path *path;
 153         /* block reservation for the operation */
 154         struct btrfs_block_rsv block_rsv;
 155         u64 qgroup_reserved;
 156         /* extra metadata reservation for relocation */
 157         int error;
 158         bool readonly;
 159         struct list_head list;
 160 };
 161
 162 static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
 163                                               struct inode *inode)
 164 {
 165         spin_lock(&BTRFS_I(inode)->lock);
 166         BTRFS_I(inode)->last_trans = trans->transaction->transid;
 167         BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
 168         BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
 169         spin_unlock(&BTRFS_I(inode)->lock);
 170 }
 171
 172 /*
 173  * Make qgroup codes to skip given qgroupid, means the old/new_roots for
 174  * qgroup won't contain the qgroupid in it.
 175  */
 176 static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
 177                                          u64 qgroupid)
 178 {
 179         struct btrfs_delayed_ref_root *delayed_refs;
 180
 181         delayed_refs = &trans->transaction->delayed_refs;
 182         WARN_ON(delayed_refs->qgroup_to_skip);
 183         delayed_refs->qgroup_to_skip = qgroupid;
 184 }
 185
 186 static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
 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 = 0;
 193 }
 194
 195 int btrfs_end_transaction(struct btrfs_trans_handle *trans);
 196 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
 197                                                    unsigned int num_items);
 198 struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
 199                                         struct btrfs_root *root,
 200                                         unsigned int num_items,
 201                                         int min_factor);
 202 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
 203 struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root);
 204 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
 205 struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
 206                                         struct btrfs_root *root);
 207 int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
 208
 209 void btrfs_add_dead_root(struct btrfs_root *root);
 210 int btrfs_defrag_root(struct btrfs_root *root);
 211 int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root);
 212 int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
 213 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
 214                                    int wait_for_unblock);
 215 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
 216 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
 217 void btrfs_throttle(struct btrfs_fs_info *fs_info);
 218 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
 219                                 struct btrfs_root *root);
 220 int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
 221                                 struct extent_io_tree *dirty_pages, int mark);
 222 int btrfs_wait_extents(struct btrfs_fs_info *fs_info,
 223                        struct extent_io_tree *dirty_pages);
 224 int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark);
 225 int btrfs_transaction_blocked(struct btrfs_fs_info *info);
 226 int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
 227 void btrfs_put_transaction(struct btrfs_transaction *transaction);
 228 void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info);
 229 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
 230                             struct btrfs_root *root);
 231 #endif