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
  27 void btrfs_tree_lock(struct extent_buffer *eb);
  28 void btrfs_tree_unlock(struct extent_buffer *eb);
  29
  30 void btrfs_tree_read_lock(struct extent_buffer *eb);
  31 void btrfs_tree_read_unlock(struct extent_buffer *eb);
  32 void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb);
  33 void btrfs_set_lock_blocking_rw(struct extent_buffer *eb, int rw);
  34 void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw);
  35 void btrfs_assert_tree_locked(struct extent_buffer *eb);
  36 int btrfs_try_tree_read_lock(struct extent_buffer *eb);
  37 int btrfs_try_tree_write_lock(struct extent_buffer *eb);
  38
  39 static inline void btrfs_tree_unlock_rw(struct extent_buffer *eb, int rw)
  40 {
  41         if (rw == BTRFS_WRITE_LOCK || rw == BTRFS_WRITE_LOCK_BLOCKING)
  42                 btrfs_tree_unlock(eb);
  43         else if (rw == BTRFS_READ_LOCK_BLOCKING)
  44                 btrfs_tree_read_unlock_blocking(eb);
  45         else if (rw == BTRFS_READ_LOCK)
  46                 btrfs_tree_read_unlock(eb);
  47         else
  48                 BUG();
  49 }
  50
  51 static inline void btrfs_set_lock_blocking(struct extent_buffer *eb)
  52 {
  53         btrfs_set_lock_blocking_rw(eb, BTRFS_WRITE_LOCK);
  54 }
  55
  56 static inline void btrfs_clear_lock_blocking(struct extent_buffer *eb)
  57 {
  58         btrfs_clear_lock_blocking_rw(eb, BTRFS_WRITE_LOCK_BLOCKING);
  59 }
  60 #endif