2 * index.h - Defines for NTFS kernel index handling. Part of the Linux-NTFS
5 * Copyright (c) 2004 Anton Altaparmakov
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.
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.
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
23 #ifndef _LINUX_NTFS_INDEX_H
24 #define _LINUX_NTFS_INDEX_H
36 * @idx_ni: index inode containing the @entry described by this context
37 * @entry: index entry (points into @ir or @ia)
38 * @data: index entry data (points into @entry)
39 * @data_len: length in bytes of @data
40 * @is_in_root: 'true' if @entry is in @ir and 'false' if it is in @ia
41 * @ir: index root if @is_in_root and NULL otherwise
42 * @actx: attribute search context if @is_in_root and NULL otherwise
43 * @base_ni: base inode if @is_in_root and NULL otherwise
44 * @ia: index block if @is_in_root is 'false' and NULL otherwise
45 * @page: page if @is_in_root is 'false' and NULL otherwise
47 * @idx_ni is the index inode this context belongs to.
49 * @entry is the index entry described by this context. @data and @data_len
50 * are the index entry data and its length in bytes, respectively. @data
51 * simply points into @entry. This is probably what the user is interested in.
53 * If @is_in_root is 'true', @entry is in the index root attribute @ir described
54 * by the attribute search context @actx and the base inode @base_ni. @ia and
55 * @page are NULL in this case.
57 * If @is_in_root is 'false', @entry is in the index allocation attribute and @ia
58 * and @page point to the index allocation block and the mapped, locked page it
59 * is in, respectively. @ir, @actx and @base_ni are NULL in this case.
61 * To obtain a context call ntfs_index_ctx_get().
63 * We use this context to allow ntfs_index_lookup() to return the found index
64 * @entry and its @data without having to allocate a buffer and copy the @entry
65 * and/or its @data into it.
67 * When finished with the @entry and its @data, call ntfs_index_ctx_put() to
68 * free the context and other associated resources.
70 * If the index entry was modified, call flush_dcache_index_entry_page()
71 * immediately after the modification and either ntfs_index_entry_mark_dirty()
72 * or ntfs_index_entry_write() before the call to ntfs_index_ctx_put() to
73 * ensure that the changes are written to disk.
82 ntfs_attr_search_ctx
*actx
;
88 extern ntfs_index_context
*ntfs_index_ctx_get(ntfs_inode
*idx_ni
);
89 extern void ntfs_index_ctx_put(ntfs_index_context
*ictx
);
91 extern int ntfs_index_lookup(const void *key
, const int key_len
,
92 ntfs_index_context
*ictx
);
97 * ntfs_index_entry_flush_dcache_page - flush_dcache_page() for index entries
98 * @ictx: ntfs index context describing the index entry
100 * Call flush_dcache_page() for the page in which an index entry resides.
102 * This must be called every time an index entry is modified, just after the
105 * If the index entry is in the index root attribute, simply flush the page
106 * containing the mft record containing the index root attribute.
108 * If the index entry is in an index block belonging to the index allocation
109 * attribute, simply flush the page cache page containing the index block.
111 static inline void ntfs_index_entry_flush_dcache_page(ntfs_index_context
*ictx
)
113 if (ictx
->is_in_root
)
114 flush_dcache_mft_record_page(ictx
->actx
->ntfs_ino
);
116 flush_dcache_page(ictx
->page
);
120 * ntfs_index_entry_mark_dirty - mark an index entry dirty
121 * @ictx: ntfs index context describing the index entry
123 * Mark the index entry described by the index entry context @ictx dirty.
125 * If the index entry is in the index root attribute, simply mark the mft
126 * record containing the index root attribute dirty. This ensures the mft
127 * record, and hence the index root attribute, will be written out to disk
130 * If the index entry is in an index block belonging to the index allocation
131 * attribute, mark the buffers belonging to the index record as well as the
132 * page cache page the index block is in dirty. This automatically marks the
133 * VFS inode of the ntfs index inode to which the index entry belongs dirty,
134 * too (I_DIRTY_PAGES) and this in turn ensures the page buffers, and hence the
135 * dirty index block, will be written out to disk later.
137 static inline void ntfs_index_entry_mark_dirty(ntfs_index_context
*ictx
)
139 if (ictx
->is_in_root
)
140 mark_mft_record_dirty(ictx
->actx
->ntfs_ino
);
142 mark_ntfs_record_dirty(ictx
->page
,
143 (u8
*)ictx
->ia
- (u8
*)page_address(ictx
->page
));
148 #endif /* _LINUX_NTFS_INDEX_H */
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