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08e0e7c8 | 1 | /* AFS filesystem file handling |
1da177e4 | 2 | * |
08e0e7c8 | 3 | * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved. |
1da177e4 LT |
4 | * Written by David Howells (dhowells@redhat.com) |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/init.h> | |
1da177e4 LT |
15 | #include <linux/slab.h> |
16 | #include <linux/fs.h> | |
17 | #include <linux/pagemap.h> | |
1da177e4 LT |
18 | #include "internal.h" |
19 | ||
1da177e4 | 20 | static int afs_file_readpage(struct file *file, struct page *page); |
2ff28e22 | 21 | static void afs_file_invalidatepage(struct page *page, unsigned long offset); |
27496a8c | 22 | static int afs_file_releasepage(struct page *page, gfp_t gfp_flags); |
1da177e4 | 23 | |
00d3b7a4 DH |
24 | const struct file_operations afs_file_operations = { |
25 | .open = afs_open, | |
26 | .release = afs_release, | |
27 | .llseek = generic_file_llseek, | |
28 | .read = do_sync_read, | |
29 | .aio_read = generic_file_aio_read, | |
30 | .mmap = generic_file_readonly_mmap, | |
31 | .sendfile = generic_file_sendfile, | |
32 | }; | |
33 | ||
754661f1 | 34 | const struct inode_operations afs_file_inode_operations = { |
1da177e4 | 35 | .getattr = afs_inode_getattr, |
00d3b7a4 | 36 | .permission = afs_permission, |
1da177e4 LT |
37 | }; |
38 | ||
f5e54d6e | 39 | const struct address_space_operations afs_fs_aops = { |
1da177e4 | 40 | .readpage = afs_file_readpage, |
1da177e4 LT |
41 | .set_page_dirty = __set_page_dirty_nobuffers, |
42 | .releasepage = afs_file_releasepage, | |
43 | .invalidatepage = afs_file_invalidatepage, | |
44 | }; | |
45 | ||
00d3b7a4 DH |
46 | /* |
47 | * open an AFS file or directory and attach a key to it | |
48 | */ | |
49 | int afs_open(struct inode *inode, struct file *file) | |
50 | { | |
51 | struct afs_vnode *vnode = AFS_FS_I(inode); | |
52 | struct key *key; | |
260a9803 | 53 | int ret; |
00d3b7a4 DH |
54 | |
55 | _enter("{%x:%x},", vnode->fid.vid, vnode->fid.vnode); | |
56 | ||
57 | key = afs_request_key(vnode->volume->cell); | |
58 | if (IS_ERR(key)) { | |
59 | _leave(" = %ld [key]", PTR_ERR(key)); | |
60 | return PTR_ERR(key); | |
61 | } | |
62 | ||
260a9803 DH |
63 | ret = afs_validate(vnode, key); |
64 | if (ret < 0) { | |
65 | _leave(" = %d [val]", ret); | |
66 | return ret; | |
67 | } | |
68 | ||
00d3b7a4 DH |
69 | file->private_data = key; |
70 | _leave(" = 0"); | |
71 | return 0; | |
72 | } | |
73 | ||
74 | /* | |
75 | * release an AFS file or directory and discard its key | |
76 | */ | |
77 | int afs_release(struct inode *inode, struct file *file) | |
78 | { | |
79 | struct afs_vnode *vnode = AFS_FS_I(inode); | |
80 | ||
81 | _enter("{%x:%x},", vnode->fid.vid, vnode->fid.vnode); | |
82 | ||
83 | key_put(file->private_data); | |
84 | _leave(" = 0"); | |
85 | return 0; | |
86 | } | |
87 | ||
1da177e4 LT |
88 | /* |
89 | * deal with notification that a page was read from the cache | |
90 | */ | |
91 | #ifdef AFS_CACHING_SUPPORT | |
92 | static void afs_file_readpage_read_complete(void *cookie_data, | |
93 | struct page *page, | |
94 | void *data, | |
95 | int error) | |
96 | { | |
97 | _enter("%p,%p,%p,%d", cookie_data, page, data, error); | |
98 | ||
99 | if (error) | |
100 | SetPageError(page); | |
101 | else | |
102 | SetPageUptodate(page); | |
103 | unlock_page(page); | |
104 | ||
ec26815a | 105 | } |
1da177e4 LT |
106 | #endif |
107 | ||
1da177e4 LT |
108 | /* |
109 | * deal with notification that a page was written to the cache | |
110 | */ | |
111 | #ifdef AFS_CACHING_SUPPORT | |
112 | static void afs_file_readpage_write_complete(void *cookie_data, | |
113 | struct page *page, | |
114 | void *data, | |
115 | int error) | |
116 | { | |
117 | _enter("%p,%p,%p,%d", cookie_data, page, data, error); | |
118 | ||
119 | unlock_page(page); | |
ec26815a | 120 | } |
1da177e4 LT |
121 | #endif |
122 | ||
1da177e4 LT |
123 | /* |
124 | * AFS read page from file (or symlink) | |
125 | */ | |
126 | static int afs_file_readpage(struct file *file, struct page *page) | |
127 | { | |
1da177e4 LT |
128 | struct afs_vnode *vnode; |
129 | struct inode *inode; | |
00d3b7a4 | 130 | struct key *key; |
08e0e7c8 DH |
131 | size_t len; |
132 | off_t offset; | |
1da177e4 LT |
133 | int ret; |
134 | ||
135 | inode = page->mapping->host; | |
136 | ||
00d3b7a4 DH |
137 | ASSERT(file != NULL); |
138 | key = file->private_data; | |
139 | ASSERT(key != NULL); | |
140 | ||
141 | _enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index); | |
1da177e4 LT |
142 | |
143 | vnode = AFS_FS_I(inode); | |
144 | ||
cd7619d6 | 145 | BUG_ON(!PageLocked(page)); |
1da177e4 LT |
146 | |
147 | ret = -ESTALE; | |
08e0e7c8 | 148 | if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) |
1da177e4 LT |
149 | goto error; |
150 | ||
151 | #ifdef AFS_CACHING_SUPPORT | |
1da177e4 LT |
152 | /* is it cached? */ |
153 | ret = cachefs_read_or_alloc_page(vnode->cache, | |
154 | page, | |
155 | afs_file_readpage_read_complete, | |
156 | NULL, | |
157 | GFP_KERNEL); | |
158 | #else | |
159 | ret = -ENOBUFS; | |
160 | #endif | |
161 | ||
162 | switch (ret) { | |
163 | /* read BIO submitted and wb-journal entry found */ | |
164 | case 1: | |
165 | BUG(); // TODO - handle wb-journal match | |
166 | ||
167 | /* read BIO submitted (page in cache) */ | |
168 | case 0: | |
169 | break; | |
170 | ||
171 | /* no page available in cache */ | |
172 | case -ENOBUFS: | |
173 | case -ENODATA: | |
174 | default: | |
08e0e7c8 DH |
175 | offset = page->index << PAGE_CACHE_SHIFT; |
176 | len = min_t(size_t, i_size_read(inode) - offset, PAGE_SIZE); | |
1da177e4 LT |
177 | |
178 | /* read the contents of the file from the server into the | |
179 | * page */ | |
00d3b7a4 | 180 | ret = afs_vnode_fetch_data(vnode, key, offset, len, page); |
1da177e4 | 181 | if (ret < 0) { |
08e0e7c8 | 182 | if (ret == -ENOENT) { |
1da177e4 LT |
183 | _debug("got NOENT from server" |
184 | " - marking file deleted and stale"); | |
08e0e7c8 | 185 | set_bit(AFS_VNODE_DELETED, &vnode->flags); |
1da177e4 LT |
186 | ret = -ESTALE; |
187 | } | |
1da177e4 LT |
188 | #ifdef AFS_CACHING_SUPPORT |
189 | cachefs_uncache_page(vnode->cache, page); | |
190 | #endif | |
191 | goto error; | |
192 | } | |
193 | ||
194 | SetPageUptodate(page); | |
195 | ||
196 | #ifdef AFS_CACHING_SUPPORT | |
197 | if (cachefs_write_page(vnode->cache, | |
198 | page, | |
199 | afs_file_readpage_write_complete, | |
200 | NULL, | |
201 | GFP_KERNEL) != 0 | |
202 | ) { | |
203 | cachefs_uncache_page(vnode->cache, page); | |
204 | unlock_page(page); | |
205 | } | |
206 | #else | |
207 | unlock_page(page); | |
208 | #endif | |
209 | } | |
210 | ||
211 | _leave(" = 0"); | |
212 | return 0; | |
213 | ||
08e0e7c8 | 214 | error: |
1da177e4 LT |
215 | SetPageError(page); |
216 | unlock_page(page); | |
1da177e4 LT |
217 | _leave(" = %d", ret); |
218 | return ret; | |
ec26815a | 219 | } |
1da177e4 | 220 | |
1da177e4 LT |
221 | /* |
222 | * get a page cookie for the specified page | |
223 | */ | |
224 | #ifdef AFS_CACHING_SUPPORT | |
225 | int afs_cache_get_page_cookie(struct page *page, | |
226 | struct cachefs_page **_page_cookie) | |
227 | { | |
228 | int ret; | |
229 | ||
230 | _enter(""); | |
231 | ret = cachefs_page_get_private(page,_page_cookie, GFP_NOIO); | |
232 | ||
233 | _leave(" = %d", ret); | |
234 | return ret; | |
ec26815a | 235 | } |
1da177e4 LT |
236 | #endif |
237 | ||
1da177e4 LT |
238 | /* |
239 | * invalidate part or all of a page | |
240 | */ | |
2ff28e22 | 241 | static void afs_file_invalidatepage(struct page *page, unsigned long offset) |
1da177e4 LT |
242 | { |
243 | int ret = 1; | |
244 | ||
245 | _enter("{%lu},%lu", page->index, offset); | |
246 | ||
247 | BUG_ON(!PageLocked(page)); | |
248 | ||
249 | if (PagePrivate(page)) { | |
250 | #ifdef AFS_CACHING_SUPPORT | |
251 | struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); | |
252 | cachefs_uncache_page(vnode->cache,page); | |
253 | #endif | |
254 | ||
255 | /* We release buffers only if the entire page is being | |
256 | * invalidated. | |
257 | * The get_block cached value has been unconditionally | |
258 | * invalidated, so real IO is not possible anymore. | |
259 | */ | |
260 | if (offset == 0) { | |
261 | BUG_ON(!PageLocked(page)); | |
262 | ||
263 | ret = 0; | |
264 | if (!PageWriteback(page)) | |
265 | ret = page->mapping->a_ops->releasepage(page, | |
266 | 0); | |
2ff28e22 | 267 | /* possibly should BUG_ON(!ret); - neilb */ |
1da177e4 LT |
268 | } |
269 | } | |
270 | ||
271 | _leave(" = %d", ret); | |
ec26815a | 272 | } |
1da177e4 | 273 | |
1da177e4 LT |
274 | /* |
275 | * release a page and cleanup its private data | |
276 | */ | |
27496a8c | 277 | static int afs_file_releasepage(struct page *page, gfp_t gfp_flags) |
1da177e4 LT |
278 | { |
279 | struct cachefs_page *pageio; | |
280 | ||
281 | _enter("{%lu},%x", page->index, gfp_flags); | |
282 | ||
283 | if (PagePrivate(page)) { | |
284 | #ifdef AFS_CACHING_SUPPORT | |
285 | struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); | |
286 | cachefs_uncache_page(vnode->cache, page); | |
287 | #endif | |
288 | ||
4c21e2f2 HD |
289 | pageio = (struct cachefs_page *) page_private(page); |
290 | set_page_private(page, 0); | |
1da177e4 LT |
291 | ClearPagePrivate(page); |
292 | ||
f99d49ad | 293 | kfree(pageio); |
1da177e4 LT |
294 | } |
295 | ||
296 | _leave(" = 0"); | |
297 | return 0; | |
ec26815a | 298 | } |