LXR linux/fs/xfs/xfs_trans

   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
  21struct xfs_log_item;
  22struct xfs_log_item_desc;
  23struct xfs_mount;
  24struct xfs_trans;
  25
  26/*
  27 * From xfs_trans_item.c
  28 */
  29struct xfs_log_item_desc        *xfs_trans_add_item(struct xfs_trans *,
  30                                            struct xfs_log_item *);
  31void                            xfs_trans_free_item(struct xfs_trans *,
  32                                            struct xfs_log_item_desc *);
  33struct xfs_log_item_desc        *xfs_trans_find_item(struct xfs_trans *,
  34                                             struct xfs_log_item *);
  35struct xfs_log_item_desc        *xfs_trans_first_item(struct xfs_trans *);
  36struct xfs_log_item_desc        *xfs_trans_next_item(struct xfs_trans *,
  37                                             struct xfs_log_item_desc *);
  38void                            xfs_trans_free_items(struct xfs_trans *, int);
  39void                            xfs_trans_unlock_items(struct xfs_trans *,
  40                                                        xfs_lsn_t);
  41void                            xfs_trans_free_busy(xfs_trans_t *tp);
  42xfs_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 */
  65struct 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 */
  75struct 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 */
  88void                    xfs_trans_ail_update(struct xfs_ail *ailp,
  89                                        struct xfs_log_item *lip, xfs_lsn_t lsn)
  90                                        __releases(ailp->xa_lock);
  91void                    xfs_trans_ail_delete(struct xfs_ail *ailp,
  92                                        struct xfs_log_item *lip)
  93                                        __releases(ailp->xa_lock);
  94void                    xfs_trans_ail_push(struct xfs_ail *, xfs_lsn_t);
  95void                    xfs_trans_unlocked_item(struct xfs_ail *,
  96                                        xfs_log_item_t *);
  97
  98xfs_lsn_t               xfs_trans_ail_tail(struct xfs_ail *ailp);
  99
 100struct xfs_log_item     *xfs_trans_ail_cursor_first(struct xfs_ail *ailp,
 101                                        struct xfs_ail_cursor *cur,
 102                                        xfs_lsn_t lsn);
 103struct xfs_log_item     *xfs_trans_ail_cursor_next(struct xfs_ail *ailp,
 104                                        struct xfs_ail_cursor *cur);
 105void                    xfs_trans_ail_cursor_done(struct xfs_ail *ailp,
 106                                        struct xfs_ail_cursor *cur);
 107
 108long    xfsaild_push(struct xfs_ail *, xfs_lsn_t *);
 109void    xfsaild_wakeup(struct xfs_ail *, xfs_lsn_t);
 110int     xfsaild_start(struct xfs_ail *);
 111void    xfsaild_stop(struct xfs_ail *);
 112
 113#if BITS_PER_LONG != 64
 114static inline void
 115xfs_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
 126static inline void
 127xfs_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__ */
 137