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12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/slab.h>
16#include <linux/fs.h>
17#include <linux/pagemap.h>
18#include <linux/writeback.h>
19#include "internal.h"
20
21static int afs_readpage(struct file *file, struct page *page);
22static void afs_invalidatepage(struct page *page, unsigned long offset);
23static int afs_releasepage(struct page *page, gfp_t gfp_flags);
24static int afs_launder_page(struct page *page);
25
26static int afs_readpages(struct file *filp, struct address_space *mapping,
27 struct list_head *pages, unsigned nr_pages);
28
29const struct file_operations afs_file_operations = {
30 .open = afs_open,
31 .release = afs_release,
32 .llseek = generic_file_llseek,
33 .read = do_sync_read,
34 .write = do_sync_write,
35 .aio_read = generic_file_aio_read,
36 .aio_write = afs_file_write,
37 .mmap = generic_file_readonly_mmap,
38 .splice_read = generic_file_splice_read,
39 .fsync = afs_fsync,
40 .lock = afs_lock,
41 .flock = afs_flock,
42};
43
44const struct inode_operations afs_file_inode_operations = {
45 .getattr = afs_getattr,
46 .setattr = afs_setattr,
47 .permission = afs_permission,
48};
49
50const struct address_space_operations afs_fs_aops = {
51 .readpage = afs_readpage,
52 .readpages = afs_readpages,
53 .set_page_dirty = afs_set_page_dirty,
54 .launder_page = afs_launder_page,
55 .releasepage = afs_releasepage,
56 .invalidatepage = afs_invalidatepage,
57 .write_begin = afs_write_begin,
58 .write_end = afs_write_end,
59 .writepage = afs_writepage,
60 .writepages = afs_writepages,
61};
62
63
64
65
66int afs_open(struct inode *inode, struct file *file)
67{
68 struct afs_vnode *vnode = AFS_FS_I(inode);
69 struct key *key;
70 int ret;
71
72 _enter("{%x:%u},", vnode->fid.vid, vnode->fid.vnode);
73
74 key = afs_request_key(vnode->volume->cell);
75 if (IS_ERR(key)) {
76 _leave(" = %ld [key]", PTR_ERR(key));
77 return PTR_ERR(key);
78 }
79
80 ret = afs_validate(vnode, key);
81 if (ret < 0) {
82 _leave(" = %d [val]", ret);
83 return ret;
84 }
85
86 file->private_data = key;
87 _leave(" = 0");
88 return 0;
89}
90
91
92
93
94int afs_release(struct inode *inode, struct file *file)
95{
96 struct afs_vnode *vnode = AFS_FS_I(inode);
97
98 _enter("{%x:%u},", vnode->fid.vid, vnode->fid.vnode);
99
100 key_put(file->private_data);
101 _leave(" = 0");
102 return 0;
103}
104
105#ifdef CONFIG_AFS_FSCACHE
106
107
108
109static void afs_file_readpage_read_complete(struct page *page,
110 void *data,
111 int error)
112{
113 _enter("%p,%p,%d", page, data, error);
114
115
116
117 if (!error)
118 SetPageUptodate(page);
119 unlock_page(page);
120}
121#endif
122
123
124
125
126static int afs_readpage(struct file *file, struct page *page)
127{
128 struct afs_vnode *vnode;
129 struct inode *inode;
130 struct key *key;
131 size_t len;
132 off_t offset;
133 int ret;
134
135 inode = page->mapping->host;
136
137 if (file) {
138 key = file->private_data;
139 ASSERT(key != NULL);
140 } else {
141 key = afs_request_key(AFS_FS_S(inode->i_sb)->volume->cell);
142 if (IS_ERR(key)) {
143 ret = PTR_ERR(key);
144 goto error_nokey;
145 }
146 }
147
148 _enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index);
149
150 vnode = AFS_FS_I(inode);
151
152 BUG_ON(!PageLocked(page));
153
154 ret = -ESTALE;
155 if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
156 goto error;
157
158
159#ifdef CONFIG_AFS_FSCACHE
160 ret = fscache_read_or_alloc_page(vnode->cache,
161 page,
162 afs_file_readpage_read_complete,
163 NULL,
164 GFP_KERNEL);
165#else
166 ret = -ENOBUFS;
167#endif
168 switch (ret) {
169
170 case 0:
171 break;
172
173
174 case -ENODATA:
175 _debug("cache said ENODATA");
176 goto go_on;
177
178
179 case -ENOBUFS:
180 _debug("cache said ENOBUFS");
181 default:
182 go_on:
183 offset = page->index << PAGE_CACHE_SHIFT;
184 len = min_t(size_t, i_size_read(inode) - offset, PAGE_SIZE);
185
186
187
188 ret = afs_vnode_fetch_data(vnode, key, offset, len, page);
189 if (ret < 0) {
190 if (ret == -ENOENT) {
191 _debug("got NOENT from server"
192 " - marking file deleted and stale");
193 set_bit(AFS_VNODE_DELETED, &vnode->flags);
194 ret = -ESTALE;
195 }
196
197#ifdef CONFIG_AFS_FSCACHE
198 fscache_uncache_page(vnode->cache, page);
199#endif
200 BUG_ON(PageFsCache(page));
201 goto error;
202 }
203
204 SetPageUptodate(page);
205
206
207#ifdef CONFIG_AFS_FSCACHE
208 if (PageFsCache(page) &&
209 fscache_write_page(vnode->cache, page, GFP_KERNEL) != 0) {
210 fscache_uncache_page(vnode->cache, page);
211 BUG_ON(PageFsCache(page));
212 }
213#endif
214 unlock_page(page);
215 }
216
217 if (!file)
218 key_put(key);
219 _leave(" = 0");
220 return 0;
221
222error:
223 SetPageError(page);
224 unlock_page(page);
225 if (!file)
226 key_put(key);
227error_nokey:
228 _leave(" = %d", ret);
229 return ret;
230}
231
232
233
234
235static int afs_readpages(struct file *file, struct address_space *mapping,
236 struct list_head *pages, unsigned nr_pages)
237{
238 struct afs_vnode *vnode;
239 int ret = 0;
240
241 _enter(",{%lu},,%d", mapping->host->i_ino, nr_pages);
242
243 vnode = AFS_FS_I(mapping->host);
244 if (vnode->flags & AFS_VNODE_DELETED) {
245 _leave(" = -ESTALE");
246 return -ESTALE;
247 }
248
249
250#ifdef CONFIG_AFS_FSCACHE
251 ret = fscache_read_or_alloc_pages(vnode->cache,
252 mapping,
253 pages,
254 &nr_pages,
255 afs_file_readpage_read_complete,
256 NULL,
257 mapping_gfp_mask(mapping));
258#else
259 ret = -ENOBUFS;
260#endif
261
262 switch (ret) {
263
264 case 0:
265 BUG_ON(!list_empty(pages));
266 BUG_ON(nr_pages != 0);
267 _leave(" = 0 [reading all]");
268 return 0;
269
270
271 case -ENODATA:
272 case -ENOBUFS:
273 break;
274
275
276 default:
277 _leave(" = %d", ret);
278 return ret;
279 }
280
281
282 ret = read_cache_pages(mapping, pages, (void *) afs_readpage, file);
283
284 _leave(" = %d [netting]", ret);
285 return ret;
286}
287
288
289
290
291static int afs_launder_page(struct page *page)
292{
293 _enter("{%lu}", page->index);
294
295 return 0;
296}
297
298
299
300
301
302
303static void afs_invalidatepage(struct page *page, unsigned long offset)
304{
305 struct afs_writeback *wb = (struct afs_writeback *) page_private(page);
306
307 _enter("{%lu},%lu", page->index, offset);
308
309 BUG_ON(!PageLocked(page));
310
311
312 if (offset == 0) {
313#ifdef CONFIG_AFS_FSCACHE
314 if (PageFsCache(page)) {
315 struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
316 fscache_wait_on_page_write(vnode->cache, page);
317 fscache_uncache_page(vnode->cache, page);
318 }
319#endif
320
321 if (PagePrivate(page)) {
322 if (wb && !PageWriteback(page)) {
323 set_page_private(page, 0);
324 afs_put_writeback(wb);
325 }
326
327 if (!page_private(page))
328 ClearPagePrivate(page);
329 }
330 }
331
332 _leave("");
333}
334
335
336
337
338
339static int afs_releasepage(struct page *page, gfp_t gfp_flags)
340{
341 struct afs_writeback *wb = (struct afs_writeback *) page_private(page);
342 struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
343
344 _enter("{{%x:%u}[%lu],%lx},%x",
345 vnode->fid.vid, vnode->fid.vnode, page->index, page->flags,
346 gfp_flags);
347
348
349
350#ifdef CONFIG_AFS_FSCACHE
351 if (!fscache_maybe_release_page(vnode->cache, page, gfp_flags)) {
352 _leave(" = F [cache busy]");
353 return 0;
354 }
355#endif
356
357 if (PagePrivate(page)) {
358 if (wb) {
359 set_page_private(page, 0);
360 afs_put_writeback(wb);
361 }
362 ClearPagePrivate(page);
363 }
364
365
366 _leave(" = T");
367 return 1;
368}
369