xref: /openbmc/linux/fs/xfs/xfs_trans_priv.h (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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__ */
125