release/src-rt-6.x.4708/linux/linux-2.6.36/fs/xfs/xfs_trans_priv.h

   1 /*
   2  * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #ifndef __XFS_TRANS_PRIV_H__
  19 #define __XFS_TRANS_PRIV_H__
  20
  21 struct xfs_log_item;
  22 struct xfs_log_item_desc;
  23 struct xfs_mount;
  24 struct xfs_trans;
  25
  26 void    xfs_trans_add_item(struct xfs_trans *, struct xfs_log_item *);
  27 void    xfs_trans_del_item(struct xfs_log_item *);
  28 void    xfs_trans_free_items(struct xfs_trans *tp, xfs_lsn_t commit_lsn,
  29                                 int flags);
  30 void    xfs_trans_item_committed(struct xfs_log_item *lip,
  31                                 xfs_lsn_t commit_lsn, int aborted);
  32 void    xfs_trans_unreserve_and_mod_sb(struct xfs_trans *tp);
  33
  34 /*
  35  * AIL traversal cursor.
  36  *
  37  * Rather than using a generation number for detecting changes in the ail, use
  38  * a cursor that is protected by the ail lock. The aild cursor exists in the
  39  * struct xfs_ail, but other traversals can declare it on the stack and link it
  40  * to the ail list.
  41  *
  42  * When an object is deleted from or moved int the AIL, the cursor list is
  43  * searched to see if the object is a designated cursor item. If it is, it is
  44  * deleted from the cursor so that the next time the cursor is used traversal
  45  * will return to the start.
  46  *
  47  * This means a traversal colliding with a removal will cause a restart of the
  48  * list scan, rather than any insertion or deletion anywhere in the list. The
  49  * low bit of the item pointer is set if the cursor has been invalidated so
  50  * that we can tell the difference between invalidation and reaching the end
  51  * of the list to trigger traversal restarts.
  52  */
  53 struct xfs_ail_cursor {
  54         struct xfs_ail_cursor   *next;
  55         struct xfs_log_item     *item;
  56 };
  57
  58 /*
  59  * Private AIL structures.
  60  *
  61  * Eventually we need to drive the locking in here as well.
  62  */
  63 struct xfs_ail {
  64         struct xfs_mount        *xa_mount;
  65         struct list_head        xa_ail;
  66         uint                    xa_gen;
  67         struct task_struct      *xa_task;
  68         xfs_lsn_t               xa_target;
  69         struct xfs_ail_cursor   xa_cursors;
  70         spinlock_t              xa_lock;
  71 };
  72
  73 /*
  74  * From xfs_trans_ail.c
  75  */
  76 void                    xfs_trans_ail_update(struct xfs_ail *ailp,
  77                                         struct xfs_log_item *lip, xfs_lsn_t lsn)
  78                                         __releases(ailp->xa_lock);
  79 void                    xfs_trans_ail_delete(struct xfs_ail *ailp,
  80                                         struct xfs_log_item *lip)
  81                                         __releases(ailp->xa_lock);
  82 void                    xfs_trans_ail_push(struct xfs_ail *, xfs_lsn_t);
  83 void                    xfs_trans_unlocked_item(struct xfs_ail *,
  84                                         xfs_log_item_t *);
  85
  86 xfs_lsn_t               xfs_trans_ail_tail(struct xfs_ail *ailp);
  87
  88 struct xfs_log_item     *xfs_trans_ail_cursor_first(struct xfs_ail *ailp,
  89                                         struct xfs_ail_cursor *cur,
  90                                         xfs_lsn_t lsn);
  91 struct xfs_log_item     *xfs_trans_ail_cursor_next(struct xfs_ail *ailp,
  92                                         struct xfs_ail_cursor *cur);
  93 void                    xfs_trans_ail_cursor_done(struct xfs_ail *ailp,
  94                                         struct xfs_ail_cursor *cur);
  95
  96 long    xfsaild_push(struct xfs_ail *, xfs_lsn_t *);
  97 void    xfsaild_wakeup(struct xfs_ail *, xfs_lsn_t);
  98 int     xfsaild_start(struct xfs_ail *);
  99 void    xfsaild_stop(struct xfs_ail *);
 100
 101 #if BITS_PER_LONG != 64
 102 static inline void
 103 xfs_trans_ail_copy_lsn(
 104         struct xfs_ail  *ailp,
 105         xfs_lsn_t       *dst,
 106         xfs_lsn_t       *src)
 107 {
 108         ASSERT(sizeof(xfs_lsn_t) == 8); /* don't lock if it shrinks */
 109         spin_lock(&ailp->xa_lock);
 110         *dst = *src;
 111         spin_unlock(&ailp->xa_lock);
 112 }
 113 #else
 114 static inline void
 115 xfs_trans_ail_copy_lsn(
 116         struct xfs_ail  *ailp,
 117         xfs_lsn_t       *dst,
 118         xfs_lsn_t       *src)
 119 {
 120         ASSERT(sizeof(xfs_lsn_t) == 8);
 121         *dst = *src;
 122 }
 123 #endif
 124 #endif  /* __XFS_TRANS_PRIV_H__ */