LXR linux/fs/btrfs/locking.h

   1/*
   2 * Copyright (C) 2008 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_LOCKING_
  20#define __BTRFS_LOCKING_
  21
  22#define BTRFS_WRITE_LOCK 1
  23#define BTRFS_READ_LOCK 2
  24#define BTRFS_WRITE_LOCK_BLOCKING 3
  25#define BTRFS_READ_LOCK_BLOCKING 4
  26
  27void btrfs_tree_lock(struct extent_buffer *eb);
  28void btrfs_tree_unlock(struct extent_buffer *eb);
  29
  30void btrfs_tree_read_lock(struct extent_buffer *eb);
  31void btrfs_tree_read_unlock(struct extent_buffer *eb);
  32void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb);
  33void btrfs_set_lock_blocking_rw(struct extent_buffer *eb, int rw);
  34void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw);
  35void btrfs_assert_tree_locked(struct extent_buffer *eb);
  36int btrfs_try_tree_read_lock(struct extent_buffer *eb);
  37int btrfs_try_tree_write_lock(struct extent_buffer *eb);
  38int btrfs_tree_read_lock_atomic(struct extent_buffer *eb);
  39
  40
  41static inline void btrfs_tree_unlock_rw(struct extent_buffer *eb, int rw)
  42{
  43        if (rw == BTRFS_WRITE_LOCK || rw == BTRFS_WRITE_LOCK_BLOCKING)
  44                btrfs_tree_unlock(eb);
  45        else if (rw == BTRFS_READ_LOCK_BLOCKING)
  46                btrfs_tree_read_unlock_blocking(eb);
  47        else if (rw == BTRFS_READ_LOCK)
  48                btrfs_tree_read_unlock(eb);
  49        else
  50                BUG();
  51}
  52
  53static inline void btrfs_set_lock_blocking(struct extent_buffer *eb)
  54{
  55        btrfs_set_lock_blocking_rw(eb, BTRFS_WRITE_LOCK);
  56}
  57
  58static inline void btrfs_clear_lock_blocking(struct extent_buffer *eb)
  59{
  60        btrfs_clear_lock_blocking_rw(eb, BTRFS_WRITE_LOCK_BLOCKING);
  61}
  62#endif
  63