xref: /linux/fs/xfs/xfs_trans_priv.h (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
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 
29 void	xfs_trans_item_committed(struct xfs_log_item *lip,
30 				xfs_lsn_t commit_lsn, int aborted);
31 void	xfs_trans_unreserve_and_mod_sb(struct xfs_trans *tp);
32 
33 /*
34  * AIL traversal cursor.
35  *
36  * Rather than using a generation number for detecting changes in the ail, use
37  * a cursor that is protected by the ail lock. The aild cursor exists in the
38  * struct xfs_ail, but other traversals can declare it on the stack and link it
39  * to the ail list.
40  *
41  * When an object is deleted from or moved int the AIL, the cursor list is
42  * searched to see if the object is a designated cursor item. If it is, it is
43  * deleted from the cursor so that the next time the cursor is used traversal
44  * will return to the start.
45  *
46  * This means a traversal colliding with a removal will cause a restart of the
47  * list scan, rather than any insertion or deletion anywhere in the list. The
48  * low bit of the item pointer is set if the cursor has been invalidated so
49  * that we can tell the difference between invalidation and reaching the end
50  * of the list to trigger traversal restarts.
51  */
52 struct xfs_ail_cursor {
53 	struct xfs_ail_cursor	*next;
54 	struct xfs_log_item	*item;
55 };
56 
57 /*
58  * Private AIL structures.
59  *
60  * Eventually we need to drive the locking in here as well.
61  */
62 struct xfs_ail {
63 	struct xfs_mount	*xa_mount;
64 	struct list_head	xa_ail;
65 	uint			xa_gen;
66 	struct task_struct	*xa_task;
67 	xfs_lsn_t		xa_target;
68 	struct xfs_ail_cursor	xa_cursors;
69 	spinlock_t		xa_lock;
70 };
71 
72 /*
73  * From xfs_trans_ail.c
74  */
75 void			xfs_trans_ail_update(struct xfs_ail *ailp,
76 					struct xfs_log_item *lip, xfs_lsn_t lsn)
77 					__releases(ailp->xa_lock);
78 void			xfs_trans_ail_delete(struct xfs_ail *ailp,
79 					struct xfs_log_item *lip)
80 					__releases(ailp->xa_lock);
81 void			xfs_trans_ail_push(struct xfs_ail *, xfs_lsn_t);
82 void			xfs_trans_unlocked_item(struct xfs_ail *,
83 					xfs_log_item_t *);
84 
85 xfs_lsn_t		xfs_trans_ail_tail(struct xfs_ail *ailp);
86 
87 struct xfs_log_item	*xfs_trans_ail_cursor_first(struct xfs_ail *ailp,
88 					struct xfs_ail_cursor *cur,
89 					xfs_lsn_t lsn);
90 struct xfs_log_item	*xfs_trans_ail_cursor_next(struct xfs_ail *ailp,
91 					struct xfs_ail_cursor *cur);
92 void			xfs_trans_ail_cursor_done(struct xfs_ail *ailp,
93 					struct xfs_ail_cursor *cur);
94 
95 long	xfsaild_push(struct xfs_ail *, xfs_lsn_t *);
96 void	xfsaild_wakeup(struct xfs_ail *, xfs_lsn_t);
97 int	xfsaild_start(struct xfs_ail *);
98 void	xfsaild_stop(struct xfs_ail *);
99 
100 #if BITS_PER_LONG != 64
101 static inline void
102 xfs_trans_ail_copy_lsn(
103 	struct xfs_ail	*ailp,
104 	xfs_lsn_t	*dst,
105 	xfs_lsn_t	*src)
106 {
107 	ASSERT(sizeof(xfs_lsn_t) == 8);	/* don't lock if it shrinks */
108 	spin_lock(&ailp->xa_lock);
109 	*dst = *src;
110 	spin_unlock(&ailp->xa_lock);
111 }
112 #else
113 static inline void
114 xfs_trans_ail_copy_lsn(
115 	struct xfs_ail	*ailp,
116 	xfs_lsn_t	*dst,
117 	xfs_lsn_t	*src)
118 {
119 	ASSERT(sizeof(xfs_lsn_t) == 8);
120 	*dst = *src;
121 }
122 #endif
123 #endif	/* __XFS_TRANS_PRIV_H__ */
124