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 /*
  27  * From xfs_trans_item.c
  28  */
  29 struct xfs_log_item_desc        *xfs_trans_add_item(struct xfs_trans *,
  30                                             struct xfs_log_item *);
  31 void                            xfs_trans_free_item(struct xfs_trans *,
  32                                             struct xfs_log_item_desc *);
  33 struct xfs_log_item_desc        *xfs_trans_find_item(struct xfs_trans *,
  34                                              struct xfs_log_item *);
  35 struct xfs_log_item_desc        *xfs_trans_first_item(struct xfs_trans *);
  36 struct xfs_log_item_desc        *xfs_trans_next_item(struct xfs_trans *,
  37                                              struct xfs_log_item_desc *);
  38 void                            xfs_trans_free_items(struct xfs_trans *, int);
  39 void                            xfs_trans_unlock_items(struct xfs_trans *,
  40                                                         xfs_lsn_t);
  41 void                            xfs_trans_free_busy(xfs_trans_t *tp);
  42 xfs_log_busy_slot_t             *xfs_trans_add_busy(xfs_trans_t *tp,
  43                                                     xfs_agnumber_t ag,
  44                                                     xfs_extlen_t idx);
  45
  46 /*
  47  * AIL traversal cursor.
  48  *
  49  * Rather than using a generation number for detecting changes in the ail, use
  50  * a cursor that is protected by the ail lock. The aild cursor exists in the
  51  * struct xfs_ail, but other traversals can declare it on the stack and link it
  52  * to the ail list.
  53  *
  54  * When an object is deleted from or moved int the AIL, the cursor list is
  55  * searched to see if the object is a designated cursor item. If it is, it is
  56  * deleted from the cursor so that the next time the cursor is used traversal
  57  * will return to the start.
  58  *
  59  * This means a traversal colliding with a removal will cause a restart of the
  60  * list scan, rather than any insertion or deletion anywhere in the list. The
  61  * low bit of the item pointer is set if the cursor has been invalidated so
  62  * that we can tell the difference between invalidation and reaching the end
  63  * of the list to trigger traversal restarts.
  64  */
  65 struct xfs_ail_cursor {
  66         struct xfs_ail_cursor   *next;
  67         struct xfs_log_item     *item;
  68 };
  69
  70 /*
  71  * Private AIL structures.
  72  *
  73  * Eventually we need to drive the locking in here as well.
  74  */
  75 struct xfs_ail {
  76         struct xfs_mount        *xa_mount;
  77         struct list_head        xa_ail;
  78         uint                    xa_gen;
  79         struct task_struct      *xa_task;
  80         xfs_lsn_t               xa_target;
  81         struct xfs_ail_cursor   xa_cursors;
  82         spinlock_t              xa_lock;
  83 };
  84
  85 /*
  86  * From xfs_trans_ail.c
  87  */
  88 void                    xfs_trans_ail_update(struct xfs_ail *ailp,
  89                                         struct xfs_log_item *lip, xfs_lsn_t lsn)
  90                                         __releases(ailp->xa_lock);
  91 void                    xfs_trans_ail_delete(struct xfs_ail *ailp,
  92                                         struct xfs_log_item *lip)
  93                                         __releases(ailp->xa_lock);
  94 void                    xfs_trans_ail_push(struct xfs_ail *, xfs_lsn_t);
  95 void                    xfs_trans_unlocked_item(struct xfs_ail *,
  96                                         xfs_log_item_t *);
  97
  98 xfs_lsn_t               xfs_trans_ail_tail(struct xfs_ail *ailp);
  99
 100 struct xfs_log_item     *xfs_trans_ail_cursor_first(struct xfs_ail *ailp,
 101                                         struct xfs_ail_cursor *cur,
 102                                         xfs_lsn_t lsn);
 103 struct xfs_log_item     *xfs_trans_ail_cursor_next(struct xfs_ail *ailp,
 104                                         struct xfs_ail_cursor *cur);
 105 void                    xfs_trans_ail_cursor_done(struct xfs_ail *ailp,
 106                                         struct xfs_ail_cursor *cur);
 107
 108 long    xfsaild_push(struct xfs_ail *, xfs_lsn_t *);
 109 void    xfsaild_wakeup(struct xfs_ail *, xfs_lsn_t);
 110 int     xfsaild_start(struct xfs_ail *);
 111 void    xfsaild_stop(struct xfs_ail *);
 112
 113 #if BITS_PER_LONG != 64
 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); /* don't lock if it shrinks */
 121         spin_lock(&ailp->xa_lock);
 122         *dst = *src;
 123         spin_unlock(&ailp->xa_lock);
 124 }
 125 #else
 126 static inline void
 127 xfs_trans_ail_copy_lsn(
 128         struct xfs_ail  *ailp,
 129         xfs_lsn_t       *dst,
 130         xfs_lsn_t       *src)
 131 {
 132         ASSERT(sizeof(xfs_lsn_t) == 8);
 133         *dst = *src;
 134 }
 135 #endif
 136 #endif  /* __XFS_TRANS_PRIV_H__ */