xref: /linux/fs/xfs/xfs_extfree_item.h (revision 9e9f60108423f18a99c9cc93ef7f23490ecc709b)
1 /*
2  * Copyright (c) 2000,2005 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_EXTFREE_ITEM_H__
19 #define	__XFS_EXTFREE_ITEM_H__
20 
21 /* kernel only EFI/EFD definitions */
22 
23 struct xfs_mount;
24 struct kmem_zone;
25 
26 /*
27  * Max number of extents in fast allocation path.
28  */
29 #define	XFS_EFI_MAX_FAST_EXTENTS	16
30 
31 /*
32  * Define EFI flag bits. Manipulated by set/clear/test_bit operators.
33  */
34 #define	XFS_EFI_RECOVERED	1
35 
36 /*
37  * This is the "extent free intention" log item.  It is used to log the fact
38  * that some extents need to be free.  It is used in conjunction with the
39  * "extent free done" log item described below.
40  *
41  * The EFI is reference counted so that it is not freed prior to both the EFI
42  * and EFD being committed and unpinned. This ensures that when the last
43  * reference goes away the EFI will always be in the AIL as it has been
44  * unpinned, regardless of whether the EFD is processed before or after the EFI.
45  */
46 typedef struct xfs_efi_log_item {
47 	xfs_log_item_t		efi_item;
48 	atomic_t		efi_refcount;
49 	atomic_t		efi_next_extent;
50 	unsigned long		efi_flags;	/* misc flags */
51 	xfs_efi_log_format_t	efi_format;
52 } xfs_efi_log_item_t;
53 
54 /*
55  * This is the "extent free done" log item.  It is used to log
56  * the fact that some extents earlier mentioned in an efi item
57  * have been freed.
58  */
59 typedef struct xfs_efd_log_item {
60 	xfs_log_item_t		efd_item;
61 	xfs_efi_log_item_t	*efd_efip;
62 	uint			efd_next_extent;
63 	xfs_efd_log_format_t	efd_format;
64 } xfs_efd_log_item_t;
65 
66 /*
67  * Max number of extents in fast allocation path.
68  */
69 #define	XFS_EFD_MAX_FAST_EXTENTS	16
70 
71 extern struct kmem_zone	*xfs_efi_zone;
72 extern struct kmem_zone	*xfs_efd_zone;
73 
74 xfs_efi_log_item_t	*xfs_efi_init(struct xfs_mount *, uint);
75 xfs_efd_log_item_t	*xfs_efd_init(struct xfs_mount *, xfs_efi_log_item_t *,
76 				      uint);
77 int			xfs_efi_copy_format(xfs_log_iovec_t *buf,
78 					    xfs_efi_log_format_t *dst_efi_fmt);
79 void			xfs_efi_item_free(xfs_efi_log_item_t *);
80 
81 #endif	/* __XFS_EXTFREE_ITEM_H__ */
82