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