xref: /openbmc/linux/fs/ntfs/lcnalloc.h (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /*
2  * lcnalloc.h - Exports for NTFS kernel cluster (de)allocation.  Part of the
3  *		Linux-NTFS project.
4  *
5  * Copyright (c) 2004 Anton Altaparmakov
6  *
7  * This program/include file is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as published
9  * by the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program/include file is distributed in the hope that it will be
13  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
14  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program (in the main directory of the Linux-NTFS
19  * distribution in the file COPYING); if not, write to the Free Software
20  * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
21  */
22 
23 #ifndef _LINUX_NTFS_LCNALLOC_H
24 #define _LINUX_NTFS_LCNALLOC_H
25 
26 #ifdef NTFS_RW
27 
28 #include <linux/fs.h>
29 
30 #include "types.h"
31 #include "runlist.h"
32 #include "volume.h"
33 
34 typedef enum {
35 	FIRST_ZONE	= 0,	/* For sanity checking. */
36 	MFT_ZONE	= 0,	/* Allocate from $MFT zone. */
37 	DATA_ZONE	= 1,	/* Allocate from $DATA zone. */
38 	LAST_ZONE	= 1,	/* For sanity checking. */
39 } NTFS_CLUSTER_ALLOCATION_ZONES;
40 
41 extern runlist_element *ntfs_cluster_alloc(ntfs_volume *vol,
42 		const VCN start_vcn, const s64 count, const LCN start_lcn,
43 		const NTFS_CLUSTER_ALLOCATION_ZONES zone);
44 
45 extern s64 __ntfs_cluster_free(struct inode *vi, const VCN start_vcn,
46 		s64 count, const BOOL is_rollback);
47 
48 /**
49  * ntfs_cluster_free - free clusters on an ntfs volume
50  * @vi:		vfs inode whose runlist describes the clusters to free
51  * @start_vcn:	vcn in the runlist of @vi at which to start freeing clusters
52  * @count:	number of clusters to free or -1 for all clusters
53  *
54  * Free @count clusters starting at the cluster @start_vcn in the runlist
55  * described by the vfs inode @vi.
56  *
57  * If @count is -1, all clusters from @start_vcn to the end of the runlist are
58  * deallocated.  Thus, to completely free all clusters in a runlist, use
59  * @start_vcn = 0 and @count = -1.
60  *
61  * Note, ntfs_cluster_free() does not modify the runlist at all, so the caller
62  * has to deal with it later.
63  *
64  * Return the number of deallocated clusters (not counting sparse ones) on
65  * success and -errno on error.
66  *
67  * Locking: - The runlist described by @vi must be unlocked on entry and is
68  *	      unlocked on return.
69  *	    - This function takes the runlist lock of @vi for reading and
70  *	      sometimes for writing and sometimes modifies the runlist.
71  *	    - The volume lcn bitmap must be unlocked on entry and is unlocked
72  *	      on return.
73  *	    - This function takes the volume lcn bitmap lock for writing and
74  *	      modifies the bitmap contents.
75  */
76 static inline s64 ntfs_cluster_free(struct inode *vi, const VCN start_vcn,
77 		s64 count)
78 {
79 	return __ntfs_cluster_free(vi, start_vcn, count, FALSE);
80 }
81 
82 extern int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol,
83 		const runlist_element *rl);
84 
85 /**
86  * ntfs_cluster_free_from_rl - free clusters from runlist
87  * @vol:	mounted ntfs volume on which to free the clusters
88  * @rl:		runlist describing the clusters to free
89  *
90  * Free all the clusters described by the runlist @rl on the volume @vol.  In
91  * the case of an error being returned, at least some of the clusters were not
92  * freed.
93  *
94  * Return 0 on success and -errno on error.
95  *
96  * Locking: This function takes the volume lcn bitmap lock for writing and
97  *	    modifies the bitmap contents.
98  */
99 static inline int ntfs_cluster_free_from_rl(ntfs_volume *vol,
100 		const runlist_element *rl)
101 {
102 	int ret;
103 
104 	down_write(&vol->lcnbmp_lock);
105 	ret = ntfs_cluster_free_from_rl_nolock(vol, rl);
106 	up_write(&vol->lcnbmp_lock);
107 	return ret;
108 }
109 
110 #endif /* NTFS_RW */
111 
112 #endif /* defined _LINUX_NTFS_LCNALLOC_H */
113