diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/ntfs/aops.h |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/ntfs/aops.h')
-rw-r--r-- | fs/ntfs/aops.h | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/fs/ntfs/aops.h b/fs/ntfs/aops.h new file mode 100644 index 000000000000..3b74e66ca2ff --- /dev/null +++ b/fs/ntfs/aops.h | |||
@@ -0,0 +1,109 @@ | |||
1 | /** | ||
2 | * aops.h - Defines for NTFS kernel address space operations and page cache | ||
3 | * handling. Part of the Linux-NTFS project. | ||
4 | * | ||
5 | * Copyright (c) 2001-2004 Anton Altaparmakov | ||
6 | * Copyright (c) 2002 Richard Russon | ||
7 | * | ||
8 | * This program/include file is free software; you can redistribute it and/or | ||
9 | * modify it under the terms of the GNU General Public License as published | ||
10 | * by the Free Software Foundation; either version 2 of the License, or | ||
11 | * (at your option) any later version. | ||
12 | * | ||
13 | * This program/include file is distributed in the hope that it will be | ||
14 | * useful, but WITHOUT ANY WARRANTY; without even the implied warranty | ||
15 | * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
16 | * GNU General Public License for more details. | ||
17 | * | ||
18 | * You should have received a copy of the GNU General Public License | ||
19 | * along with this program (in the main directory of the Linux-NTFS | ||
20 | * distribution in the file COPYING); if not, write to the Free Software | ||
21 | * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
22 | */ | ||
23 | |||
24 | #ifndef _LINUX_NTFS_AOPS_H | ||
25 | #define _LINUX_NTFS_AOPS_H | ||
26 | |||
27 | #include <linux/mm.h> | ||
28 | #include <linux/highmem.h> | ||
29 | #include <linux/pagemap.h> | ||
30 | #include <linux/fs.h> | ||
31 | |||
32 | #include "inode.h" | ||
33 | |||
34 | /** | ||
35 | * ntfs_unmap_page - release a page that was mapped using ntfs_map_page() | ||
36 | * @page: the page to release | ||
37 | * | ||
38 | * Unpin, unmap and release a page that was obtained from ntfs_map_page(). | ||
39 | */ | ||
40 | static inline void ntfs_unmap_page(struct page *page) | ||
41 | { | ||
42 | kunmap(page); | ||
43 | page_cache_release(page); | ||
44 | } | ||
45 | |||
46 | /** | ||
47 | * ntfs_map_page - map a page into accessible memory, reading it if necessary | ||
48 | * @mapping: address space for which to obtain the page | ||
49 | * @index: index into the page cache for @mapping of the page to map | ||
50 | * | ||
51 | * Read a page from the page cache of the address space @mapping at position | ||
52 | * @index, where @index is in units of PAGE_CACHE_SIZE, and not in bytes. | ||
53 | * | ||
54 | * If the page is not in memory it is loaded from disk first using the readpage | ||
55 | * method defined in the address space operations of @mapping and the page is | ||
56 | * added to the page cache of @mapping in the process. | ||
57 | * | ||
58 | * If the page belongs to an mst protected attribute and it is marked as such | ||
59 | * in its ntfs inode (NInoMstProtected()) the mst fixups are applied but no | ||
60 | * error checking is performed. This means the caller has to verify whether | ||
61 | * the ntfs record(s) contained in the page are valid or not using one of the | ||
62 | * ntfs_is_XXXX_record{,p}() macros, where XXXX is the record type you are | ||
63 | * expecting to see. (For details of the macros, see fs/ntfs/layout.h.) | ||
64 | * | ||
65 | * If the page is in high memory it is mapped into memory directly addressible | ||
66 | * by the kernel. | ||
67 | * | ||
68 | * Finally the page count is incremented, thus pinning the page into place. | ||
69 | * | ||
70 | * The above means that page_address(page) can be used on all pages obtained | ||
71 | * with ntfs_map_page() to get the kernel virtual address of the page. | ||
72 | * | ||
73 | * When finished with the page, the caller has to call ntfs_unmap_page() to | ||
74 | * unpin, unmap and release the page. | ||
75 | * | ||
76 | * Note this does not grant exclusive access. If such is desired, the caller | ||
77 | * must provide it independently of the ntfs_{un}map_page() calls by using | ||
78 | * a {rw_}semaphore or other means of serialization. A spin lock cannot be | ||
79 | * used as ntfs_map_page() can block. | ||
80 | * | ||
81 | * The unlocked and uptodate page is returned on success or an encoded error | ||
82 | * on failure. Caller has to test for error using the IS_ERR() macro on the | ||
83 | * return value. If that evaluates to TRUE, the negative error code can be | ||
84 | * obtained using PTR_ERR() on the return value of ntfs_map_page(). | ||
85 | */ | ||
86 | static inline struct page *ntfs_map_page(struct address_space *mapping, | ||
87 | unsigned long index) | ||
88 | { | ||
89 | struct page *page = read_cache_page(mapping, index, | ||
90 | (filler_t*)mapping->a_ops->readpage, NULL); | ||
91 | |||
92 | if (!IS_ERR(page)) { | ||
93 | wait_on_page_locked(page); | ||
94 | kmap(page); | ||
95 | if (PageUptodate(page) && !PageError(page)) | ||
96 | return page; | ||
97 | ntfs_unmap_page(page); | ||
98 | return ERR_PTR(-EIO); | ||
99 | } | ||
100 | return page; | ||
101 | } | ||
102 | |||
103 | #ifdef NTFS_RW | ||
104 | |||
105 | extern void mark_ntfs_record_dirty(struct page *page, const unsigned int ofs); | ||
106 | |||
107 | #endif /* NTFS_RW */ | ||
108 | |||
109 | #endif /* _LINUX_NTFS_AOPS_H */ | ||