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1da177e4 LT |
1 | /* file.c: AFS filesystem file handling |
2 | * | |
3 | * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved. | |
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 "volume.h" |
19 | #include "vnode.h" | |
20 | #include <rxrpc/call.h> | |
21 | #include "internal.h" | |
22 | ||
23 | #if 0 | |
24 | static int afs_file_open(struct inode *inode, struct file *file); | |
25 | static int afs_file_release(struct inode *inode, struct file *file); | |
26 | #endif | |
27 | ||
28 | static int afs_file_readpage(struct file *file, struct page *page); | |
2ff28e22 | 29 | static void afs_file_invalidatepage(struct page *page, unsigned long offset); |
27496a8c | 30 | static int afs_file_releasepage(struct page *page, gfp_t gfp_flags); |
1da177e4 | 31 | |
754661f1 | 32 | const struct inode_operations afs_file_inode_operations = { |
1da177e4 LT |
33 | .getattr = afs_inode_getattr, |
34 | }; | |
35 | ||
f5e54d6e | 36 | const struct address_space_operations afs_fs_aops = { |
1da177e4 | 37 | .readpage = afs_file_readpage, |
1da177e4 LT |
38 | .set_page_dirty = __set_page_dirty_nobuffers, |
39 | .releasepage = afs_file_releasepage, | |
40 | .invalidatepage = afs_file_invalidatepage, | |
41 | }; | |
42 | ||
43 | /*****************************************************************************/ | |
1da177e4 LT |
44 | /* |
45 | * deal with notification that a page was read from the cache | |
46 | */ | |
47 | #ifdef AFS_CACHING_SUPPORT | |
48 | static void afs_file_readpage_read_complete(void *cookie_data, | |
49 | struct page *page, | |
50 | void *data, | |
51 | int error) | |
52 | { | |
53 | _enter("%p,%p,%p,%d", cookie_data, page, data, error); | |
54 | ||
55 | if (error) | |
56 | SetPageError(page); | |
57 | else | |
58 | SetPageUptodate(page); | |
59 | unlock_page(page); | |
60 | ||
61 | } /* end afs_file_readpage_read_complete() */ | |
62 | #endif | |
63 | ||
64 | /*****************************************************************************/ | |
65 | /* | |
66 | * deal with notification that a page was written to the cache | |
67 | */ | |
68 | #ifdef AFS_CACHING_SUPPORT | |
69 | static void afs_file_readpage_write_complete(void *cookie_data, | |
70 | struct page *page, | |
71 | void *data, | |
72 | int error) | |
73 | { | |
74 | _enter("%p,%p,%p,%d", cookie_data, page, data, error); | |
75 | ||
76 | unlock_page(page); | |
77 | ||
78 | } /* end afs_file_readpage_write_complete() */ | |
79 | #endif | |
80 | ||
81 | /*****************************************************************************/ | |
82 | /* | |
83 | * AFS read page from file (or symlink) | |
84 | */ | |
85 | static int afs_file_readpage(struct file *file, struct page *page) | |
86 | { | |
87 | struct afs_rxfs_fetch_descriptor desc; | |
88 | #ifdef AFS_CACHING_SUPPORT | |
89 | struct cachefs_page *pageio; | |
90 | #endif | |
91 | struct afs_vnode *vnode; | |
92 | struct inode *inode; | |
93 | int ret; | |
94 | ||
95 | inode = page->mapping->host; | |
96 | ||
97 | _enter("{%lu},{%lu}", inode->i_ino, page->index); | |
98 | ||
99 | vnode = AFS_FS_I(inode); | |
100 | ||
cd7619d6 | 101 | BUG_ON(!PageLocked(page)); |
1da177e4 LT |
102 | |
103 | ret = -ESTALE; | |
104 | if (vnode->flags & AFS_VNODE_DELETED) | |
105 | goto error; | |
106 | ||
107 | #ifdef AFS_CACHING_SUPPORT | |
108 | ret = cachefs_page_get_private(page, &pageio, GFP_NOIO); | |
109 | if (ret < 0) | |
110 | goto error; | |
111 | ||
112 | /* is it cached? */ | |
113 | ret = cachefs_read_or_alloc_page(vnode->cache, | |
114 | page, | |
115 | afs_file_readpage_read_complete, | |
116 | NULL, | |
117 | GFP_KERNEL); | |
118 | #else | |
119 | ret = -ENOBUFS; | |
120 | #endif | |
121 | ||
122 | switch (ret) { | |
123 | /* read BIO submitted and wb-journal entry found */ | |
124 | case 1: | |
125 | BUG(); // TODO - handle wb-journal match | |
126 | ||
127 | /* read BIO submitted (page in cache) */ | |
128 | case 0: | |
129 | break; | |
130 | ||
131 | /* no page available in cache */ | |
132 | case -ENOBUFS: | |
133 | case -ENODATA: | |
134 | default: | |
135 | desc.fid = vnode->fid; | |
136 | desc.offset = page->index << PAGE_CACHE_SHIFT; | |
137 | desc.size = min((size_t) (inode->i_size - desc.offset), | |
138 | (size_t) PAGE_SIZE); | |
139 | desc.buffer = kmap(page); | |
140 | ||
141 | clear_page(desc.buffer); | |
142 | ||
143 | /* read the contents of the file from the server into the | |
144 | * page */ | |
145 | ret = afs_vnode_fetch_data(vnode, &desc); | |
146 | kunmap(page); | |
147 | if (ret < 0) { | |
148 | if (ret==-ENOENT) { | |
149 | _debug("got NOENT from server" | |
150 | " - marking file deleted and stale"); | |
151 | vnode->flags |= AFS_VNODE_DELETED; | |
152 | ret = -ESTALE; | |
153 | } | |
154 | ||
155 | #ifdef AFS_CACHING_SUPPORT | |
156 | cachefs_uncache_page(vnode->cache, page); | |
157 | #endif | |
158 | goto error; | |
159 | } | |
160 | ||
161 | SetPageUptodate(page); | |
162 | ||
163 | #ifdef AFS_CACHING_SUPPORT | |
164 | if (cachefs_write_page(vnode->cache, | |
165 | page, | |
166 | afs_file_readpage_write_complete, | |
167 | NULL, | |
168 | GFP_KERNEL) != 0 | |
169 | ) { | |
170 | cachefs_uncache_page(vnode->cache, page); | |
171 | unlock_page(page); | |
172 | } | |
173 | #else | |
174 | unlock_page(page); | |
175 | #endif | |
176 | } | |
177 | ||
178 | _leave(" = 0"); | |
179 | return 0; | |
180 | ||
181 | error: | |
182 | SetPageError(page); | |
183 | unlock_page(page); | |
184 | ||
185 | _leave(" = %d", ret); | |
186 | return ret; | |
187 | ||
188 | } /* end afs_file_readpage() */ | |
189 | ||
190 | /*****************************************************************************/ | |
191 | /* | |
192 | * get a page cookie for the specified page | |
193 | */ | |
194 | #ifdef AFS_CACHING_SUPPORT | |
195 | int afs_cache_get_page_cookie(struct page *page, | |
196 | struct cachefs_page **_page_cookie) | |
197 | { | |
198 | int ret; | |
199 | ||
200 | _enter(""); | |
201 | ret = cachefs_page_get_private(page,_page_cookie, GFP_NOIO); | |
202 | ||
203 | _leave(" = %d", ret); | |
204 | return ret; | |
205 | } /* end afs_cache_get_page_cookie() */ | |
206 | #endif | |
207 | ||
208 | /*****************************************************************************/ | |
209 | /* | |
210 | * invalidate part or all of a page | |
211 | */ | |
2ff28e22 | 212 | static void afs_file_invalidatepage(struct page *page, unsigned long offset) |
1da177e4 LT |
213 | { |
214 | int ret = 1; | |
215 | ||
216 | _enter("{%lu},%lu", page->index, offset); | |
217 | ||
218 | BUG_ON(!PageLocked(page)); | |
219 | ||
220 | if (PagePrivate(page)) { | |
221 | #ifdef AFS_CACHING_SUPPORT | |
222 | struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); | |
223 | cachefs_uncache_page(vnode->cache,page); | |
224 | #endif | |
225 | ||
226 | /* We release buffers only if the entire page is being | |
227 | * invalidated. | |
228 | * The get_block cached value has been unconditionally | |
229 | * invalidated, so real IO is not possible anymore. | |
230 | */ | |
231 | if (offset == 0) { | |
232 | BUG_ON(!PageLocked(page)); | |
233 | ||
234 | ret = 0; | |
235 | if (!PageWriteback(page)) | |
236 | ret = page->mapping->a_ops->releasepage(page, | |
237 | 0); | |
2ff28e22 | 238 | /* possibly should BUG_ON(!ret); - neilb */ |
1da177e4 LT |
239 | } |
240 | } | |
241 | ||
242 | _leave(" = %d", ret); | |
1da177e4 LT |
243 | } /* end afs_file_invalidatepage() */ |
244 | ||
245 | /*****************************************************************************/ | |
246 | /* | |
247 | * release a page and cleanup its private data | |
248 | */ | |
27496a8c | 249 | static int afs_file_releasepage(struct page *page, gfp_t gfp_flags) |
1da177e4 LT |
250 | { |
251 | struct cachefs_page *pageio; | |
252 | ||
253 | _enter("{%lu},%x", page->index, gfp_flags); | |
254 | ||
255 | if (PagePrivate(page)) { | |
256 | #ifdef AFS_CACHING_SUPPORT | |
257 | struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); | |
258 | cachefs_uncache_page(vnode->cache, page); | |
259 | #endif | |
260 | ||
4c21e2f2 HD |
261 | pageio = (struct cachefs_page *) page_private(page); |
262 | set_page_private(page, 0); | |
1da177e4 LT |
263 | ClearPagePrivate(page); |
264 | ||
f99d49ad | 265 | kfree(pageio); |
1da177e4 LT |
266 | } |
267 | ||
268 | _leave(" = 0"); | |
269 | return 0; | |
270 | } /* end afs_file_releasepage() */ |