Commit | Line | Data |
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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/fs.h> |
16 | #include <linux/pagemap.h> | |
31143d5d | 17 | #include <linux/writeback.h> |
5a0e3ad6 | 18 | #include <linux/gfp.h> |
1da177e4 LT |
19 | #include "internal.h" |
20 | ||
416351f2 | 21 | static int afs_readpage(struct file *file, struct page *page); |
d47992f8 LC |
22 | static void afs_invalidatepage(struct page *page, unsigned int offset, |
23 | unsigned int length); | |
416351f2 | 24 | static int afs_releasepage(struct page *page, gfp_t gfp_flags); |
31143d5d | 25 | static int afs_launder_page(struct page *page); |
1da177e4 | 26 | |
9b3f26c9 DH |
27 | static int afs_readpages(struct file *filp, struct address_space *mapping, |
28 | struct list_head *pages, unsigned nr_pages); | |
29 | ||
00d3b7a4 DH |
30 | const struct file_operations afs_file_operations = { |
31 | .open = afs_open, | |
32 | .release = afs_release, | |
33 | .llseek = generic_file_llseek, | |
aad4f8bb | 34 | .read_iter = generic_file_read_iter, |
50b5551d | 35 | .write_iter = afs_file_write, |
00d3b7a4 | 36 | .mmap = generic_file_readonly_mmap, |
5ffc4ef4 | 37 | .splice_read = generic_file_splice_read, |
31143d5d | 38 | .fsync = afs_fsync, |
e8d6c554 DH |
39 | .lock = afs_lock, |
40 | .flock = afs_flock, | |
00d3b7a4 DH |
41 | }; |
42 | ||
754661f1 | 43 | const struct inode_operations afs_file_inode_operations = { |
416351f2 | 44 | .getattr = afs_getattr, |
31143d5d | 45 | .setattr = afs_setattr, |
00d3b7a4 | 46 | .permission = afs_permission, |
1da177e4 LT |
47 | }; |
48 | ||
f5e54d6e | 49 | const struct address_space_operations afs_fs_aops = { |
416351f2 | 50 | .readpage = afs_readpage, |
9b3f26c9 | 51 | .readpages = afs_readpages, |
31143d5d DH |
52 | .set_page_dirty = afs_set_page_dirty, |
53 | .launder_page = afs_launder_page, | |
416351f2 DH |
54 | .releasepage = afs_releasepage, |
55 | .invalidatepage = afs_invalidatepage, | |
15b4650e NP |
56 | .write_begin = afs_write_begin, |
57 | .write_end = afs_write_end, | |
31143d5d DH |
58 | .writepage = afs_writepage, |
59 | .writepages = afs_writepages, | |
1da177e4 LT |
60 | }; |
61 | ||
00d3b7a4 DH |
62 | /* |
63 | * open an AFS file or directory and attach a key to it | |
64 | */ | |
65 | int afs_open(struct inode *inode, struct file *file) | |
66 | { | |
67 | struct afs_vnode *vnode = AFS_FS_I(inode); | |
68 | struct key *key; | |
260a9803 | 69 | int ret; |
00d3b7a4 | 70 | |
416351f2 | 71 | _enter("{%x:%u},", vnode->fid.vid, vnode->fid.vnode); |
00d3b7a4 DH |
72 | |
73 | key = afs_request_key(vnode->volume->cell); | |
74 | if (IS_ERR(key)) { | |
75 | _leave(" = %ld [key]", PTR_ERR(key)); | |
76 | return PTR_ERR(key); | |
77 | } | |
78 | ||
260a9803 DH |
79 | ret = afs_validate(vnode, key); |
80 | if (ret < 0) { | |
81 | _leave(" = %d [val]", ret); | |
82 | return ret; | |
83 | } | |
84 | ||
00d3b7a4 DH |
85 | file->private_data = key; |
86 | _leave(" = 0"); | |
87 | return 0; | |
88 | } | |
89 | ||
90 | /* | |
91 | * release an AFS file or directory and discard its key | |
92 | */ | |
93 | int afs_release(struct inode *inode, struct file *file) | |
94 | { | |
95 | struct afs_vnode *vnode = AFS_FS_I(inode); | |
96 | ||
416351f2 | 97 | _enter("{%x:%u},", vnode->fid.vid, vnode->fid.vnode); |
00d3b7a4 DH |
98 | |
99 | key_put(file->private_data); | |
100 | _leave(" = 0"); | |
101 | return 0; | |
102 | } | |
103 | ||
6566abdb | 104 | #ifdef CONFIG_AFS_FSCACHE |
1da177e4 LT |
105 | /* |
106 | * deal with notification that a page was read from the cache | |
107 | */ | |
9b3f26c9 DH |
108 | static void afs_file_readpage_read_complete(struct page *page, |
109 | void *data, | |
110 | int error) | |
1da177e4 | 111 | { |
9b3f26c9 | 112 | _enter("%p,%p,%d", page, data, error); |
1da177e4 | 113 | |
9b3f26c9 DH |
114 | /* if the read completes with an error, we just unlock the page and let |
115 | * the VM reissue the readpage */ | |
116 | if (!error) | |
1da177e4 LT |
117 | SetPageUptodate(page); |
118 | unlock_page(page); | |
ec26815a | 119 | } |
6566abdb | 120 | #endif |
1da177e4 | 121 | |
1da177e4 | 122 | /* |
f6d335c0 | 123 | * read page from file, directory or symlink, given a key to use |
1da177e4 | 124 | */ |
f6d335c0 | 125 | int afs_page_filler(void *data, struct page *page) |
1da177e4 | 126 | { |
f6d335c0 AV |
127 | struct inode *inode = page->mapping->host; |
128 | struct afs_vnode *vnode = AFS_FS_I(inode); | |
129 | struct key *key = data; | |
08e0e7c8 DH |
130 | size_t len; |
131 | off_t offset; | |
1da177e4 LT |
132 | int ret; |
133 | ||
00d3b7a4 | 134 | _enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index); |
1da177e4 | 135 | |
cd7619d6 | 136 | BUG_ON(!PageLocked(page)); |
1da177e4 LT |
137 | |
138 | ret = -ESTALE; | |
08e0e7c8 | 139 | if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) |
1da177e4 LT |
140 | goto error; |
141 | ||
1da177e4 | 142 | /* is it cached? */ |
9b3f26c9 DH |
143 | #ifdef CONFIG_AFS_FSCACHE |
144 | ret = fscache_read_or_alloc_page(vnode->cache, | |
1da177e4 LT |
145 | page, |
146 | afs_file_readpage_read_complete, | |
147 | NULL, | |
148 | GFP_KERNEL); | |
149 | #else | |
150 | ret = -ENOBUFS; | |
151 | #endif | |
1da177e4 | 152 | switch (ret) { |
1da177e4 LT |
153 | /* read BIO submitted (page in cache) */ |
154 | case 0: | |
155 | break; | |
156 | ||
9b3f26c9 | 157 | /* page not yet cached */ |
1da177e4 | 158 | case -ENODATA: |
9b3f26c9 DH |
159 | _debug("cache said ENODATA"); |
160 | goto go_on; | |
161 | ||
162 | /* page will not be cached */ | |
163 | case -ENOBUFS: | |
164 | _debug("cache said ENOBUFS"); | |
1da177e4 | 165 | default: |
9b3f26c9 | 166 | go_on: |
09cbfeaf | 167 | offset = page->index << PAGE_SHIFT; |
08e0e7c8 | 168 | len = min_t(size_t, i_size_read(inode) - offset, PAGE_SIZE); |
1da177e4 LT |
169 | |
170 | /* read the contents of the file from the server into the | |
171 | * page */ | |
00d3b7a4 | 172 | ret = afs_vnode_fetch_data(vnode, key, offset, len, page); |
1da177e4 | 173 | if (ret < 0) { |
08e0e7c8 | 174 | if (ret == -ENOENT) { |
1da177e4 LT |
175 | _debug("got NOENT from server" |
176 | " - marking file deleted and stale"); | |
08e0e7c8 | 177 | set_bit(AFS_VNODE_DELETED, &vnode->flags); |
1da177e4 LT |
178 | ret = -ESTALE; |
179 | } | |
9b3f26c9 DH |
180 | |
181 | #ifdef CONFIG_AFS_FSCACHE | |
182 | fscache_uncache_page(vnode->cache, page); | |
1da177e4 | 183 | #endif |
9b3f26c9 | 184 | BUG_ON(PageFsCache(page)); |
1da177e4 LT |
185 | goto error; |
186 | } | |
187 | ||
188 | SetPageUptodate(page); | |
189 | ||
9b3f26c9 DH |
190 | /* send the page to the cache */ |
191 | #ifdef CONFIG_AFS_FSCACHE | |
192 | if (PageFsCache(page) && | |
193 | fscache_write_page(vnode->cache, page, GFP_KERNEL) != 0) { | |
194 | fscache_uncache_page(vnode->cache, page); | |
195 | BUG_ON(PageFsCache(page)); | |
1da177e4 | 196 | } |
1da177e4 | 197 | #endif |
9b3f26c9 | 198 | unlock_page(page); |
1da177e4 LT |
199 | } |
200 | ||
201 | _leave(" = 0"); | |
202 | return 0; | |
203 | ||
08e0e7c8 | 204 | error: |
1da177e4 LT |
205 | SetPageError(page); |
206 | unlock_page(page); | |
1da177e4 LT |
207 | _leave(" = %d", ret); |
208 | return ret; | |
ec26815a | 209 | } |
1da177e4 | 210 | |
f6d335c0 AV |
211 | /* |
212 | * read page from file, directory or symlink, given a file to nominate the key | |
213 | * to be used | |
214 | */ | |
215 | static int afs_readpage(struct file *file, struct page *page) | |
216 | { | |
217 | struct key *key; | |
218 | int ret; | |
219 | ||
220 | if (file) { | |
221 | key = file->private_data; | |
222 | ASSERT(key != NULL); | |
223 | ret = afs_page_filler(key, page); | |
224 | } else { | |
225 | struct inode *inode = page->mapping->host; | |
226 | key = afs_request_key(AFS_FS_S(inode->i_sb)->volume->cell); | |
227 | if (IS_ERR(key)) { | |
228 | ret = PTR_ERR(key); | |
229 | } else { | |
230 | ret = afs_page_filler(key, page); | |
231 | key_put(key); | |
232 | } | |
233 | } | |
234 | return ret; | |
235 | } | |
236 | ||
1da177e4 | 237 | /* |
9b3f26c9 | 238 | * read a set of pages |
1da177e4 | 239 | */ |
9b3f26c9 DH |
240 | static int afs_readpages(struct file *file, struct address_space *mapping, |
241 | struct list_head *pages, unsigned nr_pages) | |
1da177e4 | 242 | { |
f6d335c0 | 243 | struct key *key = file->private_data; |
9b3f26c9 DH |
244 | struct afs_vnode *vnode; |
245 | int ret = 0; | |
1da177e4 | 246 | |
f6d335c0 AV |
247 | _enter("{%d},{%lu},,%d", |
248 | key_serial(key), mapping->host->i_ino, nr_pages); | |
249 | ||
250 | ASSERT(key != NULL); | |
1da177e4 | 251 | |
9b3f26c9 | 252 | vnode = AFS_FS_I(mapping->host); |
ad2a8e60 | 253 | if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) { |
9b3f26c9 DH |
254 | _leave(" = -ESTALE"); |
255 | return -ESTALE; | |
256 | } | |
1da177e4 | 257 | |
9b3f26c9 DH |
258 | /* attempt to read as many of the pages as possible */ |
259 | #ifdef CONFIG_AFS_FSCACHE | |
260 | ret = fscache_read_or_alloc_pages(vnode->cache, | |
261 | mapping, | |
262 | pages, | |
263 | &nr_pages, | |
264 | afs_file_readpage_read_complete, | |
265 | NULL, | |
266 | mapping_gfp_mask(mapping)); | |
267 | #else | |
268 | ret = -ENOBUFS; | |
269 | #endif | |
270 | ||
271 | switch (ret) { | |
272 | /* all pages are being read from the cache */ | |
273 | case 0: | |
274 | BUG_ON(!list_empty(pages)); | |
275 | BUG_ON(nr_pages != 0); | |
276 | _leave(" = 0 [reading all]"); | |
277 | return 0; | |
278 | ||
279 | /* there were pages that couldn't be read from the cache */ | |
280 | case -ENODATA: | |
281 | case -ENOBUFS: | |
282 | break; | |
283 | ||
284 | /* other error */ | |
285 | default: | |
286 | _leave(" = %d", ret); | |
287 | return ret; | |
1da177e4 LT |
288 | } |
289 | ||
9b3f26c9 | 290 | /* load the missing pages from the network */ |
f6d335c0 | 291 | ret = read_cache_pages(mapping, pages, afs_page_filler, key); |
9b3f26c9 DH |
292 | |
293 | _leave(" = %d [netting]", ret); | |
294 | return ret; | |
ec26815a | 295 | } |
1da177e4 | 296 | |
31143d5d DH |
297 | /* |
298 | * write back a dirty page | |
299 | */ | |
300 | static int afs_launder_page(struct page *page) | |
301 | { | |
302 | _enter("{%lu}", page->index); | |
303 | ||
304 | return 0; | |
305 | } | |
306 | ||
1da177e4 | 307 | /* |
9b3f26c9 DH |
308 | * invalidate part or all of a page |
309 | * - release a page and clean up its private data if offset is 0 (indicating | |
310 | * the entire page) | |
311 | */ | |
d47992f8 LC |
312 | static void afs_invalidatepage(struct page *page, unsigned int offset, |
313 | unsigned int length) | |
9b3f26c9 DH |
314 | { |
315 | struct afs_writeback *wb = (struct afs_writeback *) page_private(page); | |
316 | ||
d47992f8 | 317 | _enter("{%lu},%u,%u", page->index, offset, length); |
9b3f26c9 DH |
318 | |
319 | BUG_ON(!PageLocked(page)); | |
320 | ||
321 | /* we clean up only if the entire page is being invalidated */ | |
09cbfeaf | 322 | if (offset == 0 && length == PAGE_SIZE) { |
9b3f26c9 DH |
323 | #ifdef CONFIG_AFS_FSCACHE |
324 | if (PageFsCache(page)) { | |
325 | struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); | |
326 | fscache_wait_on_page_write(vnode->cache, page); | |
327 | fscache_uncache_page(vnode->cache, page); | |
9b3f26c9 DH |
328 | } |
329 | #endif | |
330 | ||
331 | if (PagePrivate(page)) { | |
332 | if (wb && !PageWriteback(page)) { | |
333 | set_page_private(page, 0); | |
334 | afs_put_writeback(wb); | |
335 | } | |
336 | ||
337 | if (!page_private(page)) | |
338 | ClearPagePrivate(page); | |
339 | } | |
340 | } | |
341 | ||
342 | _leave(""); | |
343 | } | |
344 | ||
345 | /* | |
346 | * release a page and clean up its private state if it's not busy | |
347 | * - return true if the page can now be released, false if not | |
1da177e4 | 348 | */ |
416351f2 | 349 | static int afs_releasepage(struct page *page, gfp_t gfp_flags) |
1da177e4 | 350 | { |
9b3f26c9 | 351 | struct afs_writeback *wb = (struct afs_writeback *) page_private(page); |
416351f2 | 352 | struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); |
1da177e4 | 353 | |
416351f2 DH |
354 | _enter("{{%x:%u}[%lu],%lx},%x", |
355 | vnode->fid.vid, vnode->fid.vnode, page->index, page->flags, | |
356 | gfp_flags); | |
1da177e4 | 357 | |
9b3f26c9 DH |
358 | /* deny if page is being written to the cache and the caller hasn't |
359 | * elected to wait */ | |
360 | #ifdef CONFIG_AFS_FSCACHE | |
201a1542 DH |
361 | if (!fscache_maybe_release_page(vnode->cache, page, gfp_flags)) { |
362 | _leave(" = F [cache busy]"); | |
363 | return 0; | |
9b3f26c9 DH |
364 | } |
365 | #endif | |
366 | ||
1da177e4 | 367 | if (PagePrivate(page)) { |
9b3f26c9 DH |
368 | if (wb) { |
369 | set_page_private(page, 0); | |
370 | afs_put_writeback(wb); | |
371 | } | |
1da177e4 | 372 | ClearPagePrivate(page); |
1da177e4 LT |
373 | } |
374 | ||
9b3f26c9 DH |
375 | /* indicate that the page can be released */ |
376 | _leave(" = T"); | |
377 | return 1; | |
ec26815a | 378 | } |