Commit | Line | Data |
---|---|---|
2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
31143d5d DH |
2 | /* handling of writes to regular files and writing back to the server |
3 | * | |
4 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. | |
5 | * Written by David Howells (dhowells@redhat.com) | |
31143d5d | 6 | */ |
4343d008 | 7 | |
4af3c9cc | 8 | #include <linux/backing-dev.h> |
31143d5d DH |
9 | #include <linux/slab.h> |
10 | #include <linux/fs.h> | |
11 | #include <linux/pagemap.h> | |
12 | #include <linux/writeback.h> | |
13 | #include <linux/pagevec.h> | |
14 | #include "internal.h" | |
15 | ||
31143d5d DH |
16 | /* |
17 | * mark a page as having been made dirty and thus needing writeback | |
18 | */ | |
19 | int afs_set_page_dirty(struct page *page) | |
20 | { | |
21 | _enter(""); | |
22 | return __set_page_dirty_nobuffers(page); | |
23 | } | |
24 | ||
31143d5d DH |
25 | /* |
26 | * partly or wholly fill a page that's under preparation for writing | |
27 | */ | |
28 | static int afs_fill_page(struct afs_vnode *vnode, struct key *key, | |
e8e581a8 | 29 | loff_t pos, unsigned int len, struct page *page) |
31143d5d | 30 | { |
196ee9cd | 31 | struct afs_read *req; |
2a0b4f64 DH |
32 | size_t p; |
33 | void *data; | |
31143d5d DH |
34 | int ret; |
35 | ||
5e7f2337 | 36 | _enter(",,%llu", (unsigned long long)pos); |
31143d5d | 37 | |
2a0b4f64 DH |
38 | if (pos >= vnode->vfs_inode.i_size) { |
39 | p = pos & ~PAGE_MASK; | |
40 | ASSERTCMP(p + len, <=, PAGE_SIZE); | |
41 | data = kmap(page); | |
42 | memset(data + p, 0, len); | |
43 | kunmap(page); | |
44 | return 0; | |
45 | } | |
46 | ||
ee102584 | 47 | req = kzalloc(struct_size(req, array, 1), GFP_KERNEL); |
196ee9cd DH |
48 | if (!req) |
49 | return -ENOMEM; | |
50 | ||
f3ddee8d | 51 | refcount_set(&req->usage, 1); |
196ee9cd | 52 | req->pos = pos; |
e8e581a8 | 53 | req->len = len; |
196ee9cd | 54 | req->nr_pages = 1; |
f3ddee8d | 55 | req->pages = req->array; |
196ee9cd | 56 | req->pages[0] = page; |
5611ef28 | 57 | get_page(page); |
196ee9cd | 58 | |
d2ddc776 | 59 | ret = afs_fetch_data(vnode, key, req); |
196ee9cd | 60 | afs_put_read(req); |
31143d5d DH |
61 | if (ret < 0) { |
62 | if (ret == -ENOENT) { | |
63 | _debug("got NOENT from server" | |
64 | " - marking file deleted and stale"); | |
65 | set_bit(AFS_VNODE_DELETED, &vnode->flags); | |
66 | ret = -ESTALE; | |
67 | } | |
68 | } | |
69 | ||
70 | _leave(" = %d", ret); | |
71 | return ret; | |
72 | } | |
73 | ||
31143d5d DH |
74 | /* |
75 | * prepare to perform part of a write to a page | |
31143d5d | 76 | */ |
15b4650e NP |
77 | int afs_write_begin(struct file *file, struct address_space *mapping, |
78 | loff_t pos, unsigned len, unsigned flags, | |
79 | struct page **pagep, void **fsdata) | |
31143d5d | 80 | { |
496ad9aa | 81 | struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); |
15b4650e | 82 | struct page *page; |
215804a9 | 83 | struct key *key = afs_file_key(file); |
4343d008 DH |
84 | unsigned long priv; |
85 | unsigned f, from = pos & (PAGE_SIZE - 1); | |
86 | unsigned t, to = from + len; | |
09cbfeaf | 87 | pgoff_t index = pos >> PAGE_SHIFT; |
31143d5d DH |
88 | int ret; |
89 | ||
3b6492df | 90 | _enter("{%llx:%llu},{%lx},%u,%u", |
15b4650e | 91 | vnode->fid.vid, vnode->fid.vnode, index, from, to); |
31143d5d | 92 | |
4343d008 DH |
93 | /* We want to store information about how much of a page is altered in |
94 | * page->private. | |
95 | */ | |
96 | BUILD_BUG_ON(PAGE_SIZE > 32768 && sizeof(page->private) < 8); | |
31143d5d | 97 | |
54566b2c | 98 | page = grab_cache_page_write_begin(mapping, index, flags); |
4343d008 | 99 | if (!page) |
15b4650e | 100 | return -ENOMEM; |
15b4650e | 101 | |
09cbfeaf | 102 | if (!PageUptodate(page) && len != PAGE_SIZE) { |
e8e581a8 | 103 | ret = afs_fill_page(vnode, key, pos & PAGE_MASK, PAGE_SIZE, page); |
31143d5d | 104 | if (ret < 0) { |
6d06b0d2 DH |
105 | unlock_page(page); |
106 | put_page(page); | |
31143d5d DH |
107 | _leave(" = %d [prep]", ret); |
108 | return ret; | |
109 | } | |
15b4650e | 110 | SetPageUptodate(page); |
31143d5d DH |
111 | } |
112 | ||
6d06b0d2 DH |
113 | /* page won't leak in error case: it eventually gets cleaned off LRU */ |
114 | *pagep = page; | |
115 | ||
31143d5d | 116 | try_again: |
4343d008 DH |
117 | /* See if this page is already partially written in a way that we can |
118 | * merge the new write with. | |
119 | */ | |
120 | t = f = 0; | |
121 | if (PagePrivate(page)) { | |
122 | priv = page_private(page); | |
123 | f = priv & AFS_PRIV_MAX; | |
124 | t = priv >> AFS_PRIV_SHIFT; | |
125 | ASSERTCMP(f, <=, t); | |
31143d5d DH |
126 | } |
127 | ||
4343d008 | 128 | if (f != t) { |
5a039c32 DH |
129 | if (PageWriteback(page)) { |
130 | trace_afs_page_dirty(vnode, tracepoint_string("alrdy"), | |
131 | page->index, priv); | |
132 | goto flush_conflicting_write; | |
133 | } | |
5a813276 DH |
134 | /* If the file is being filled locally, allow inter-write |
135 | * spaces to be merged into writes. If it's not, only write | |
136 | * back what the user gives us. | |
137 | */ | |
138 | if (!test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags) && | |
139 | (to < f || from > t)) | |
4343d008 DH |
140 | goto flush_conflicting_write; |
141 | if (from < f) | |
142 | f = from; | |
143 | if (to > t) | |
144 | t = to; | |
145 | } else { | |
146 | f = from; | |
147 | t = to; | |
31143d5d DH |
148 | } |
149 | ||
4343d008 DH |
150 | priv = (unsigned long)t << AFS_PRIV_SHIFT; |
151 | priv |= f; | |
13524ab3 DH |
152 | trace_afs_page_dirty(vnode, tracepoint_string("begin"), |
153 | page->index, priv); | |
31143d5d | 154 | SetPagePrivate(page); |
4343d008 DH |
155 | set_page_private(page, priv); |
156 | _leave(" = 0"); | |
31143d5d DH |
157 | return 0; |
158 | ||
4343d008 DH |
159 | /* The previous write and this write aren't adjacent or overlapping, so |
160 | * flush the page out. | |
161 | */ | |
162 | flush_conflicting_write: | |
31143d5d | 163 | _debug("flush conflict"); |
4343d008 DH |
164 | ret = write_one_page(page); |
165 | if (ret < 0) { | |
166 | _leave(" = %d", ret); | |
167 | return ret; | |
31143d5d DH |
168 | } |
169 | ||
4343d008 DH |
170 | ret = lock_page_killable(page); |
171 | if (ret < 0) { | |
172 | _leave(" = %d", ret); | |
173 | return ret; | |
174 | } | |
31143d5d DH |
175 | goto try_again; |
176 | } | |
177 | ||
178 | /* | |
179 | * finalise part of a write to a page | |
180 | */ | |
15b4650e NP |
181 | int afs_write_end(struct file *file, struct address_space *mapping, |
182 | loff_t pos, unsigned len, unsigned copied, | |
183 | struct page *page, void *fsdata) | |
31143d5d | 184 | { |
496ad9aa | 185 | struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); |
215804a9 | 186 | struct key *key = afs_file_key(file); |
31143d5d | 187 | loff_t i_size, maybe_i_size; |
e8e581a8 | 188 | int ret; |
31143d5d | 189 | |
3b6492df | 190 | _enter("{%llx:%llu},{%lx}", |
15b4650e | 191 | vnode->fid.vid, vnode->fid.vnode, page->index); |
31143d5d | 192 | |
15b4650e | 193 | maybe_i_size = pos + copied; |
31143d5d DH |
194 | |
195 | i_size = i_size_read(&vnode->vfs_inode); | |
196 | if (maybe_i_size > i_size) { | |
4343d008 | 197 | spin_lock(&vnode->wb_lock); |
31143d5d DH |
198 | i_size = i_size_read(&vnode->vfs_inode); |
199 | if (maybe_i_size > i_size) | |
200 | i_size_write(&vnode->vfs_inode, maybe_i_size); | |
4343d008 | 201 | spin_unlock(&vnode->wb_lock); |
31143d5d DH |
202 | } |
203 | ||
e8e581a8 DH |
204 | if (!PageUptodate(page)) { |
205 | if (copied < len) { | |
206 | /* Try and load any missing data from the server. The | |
207 | * unmarshalling routine will take care of clearing any | |
208 | * bits that are beyond the EOF. | |
209 | */ | |
210 | ret = afs_fill_page(vnode, key, pos + copied, | |
211 | len - copied, page); | |
212 | if (ret < 0) | |
afae457d | 213 | goto out; |
e8e581a8 DH |
214 | } |
215 | SetPageUptodate(page); | |
216 | } | |
217 | ||
31143d5d | 218 | set_page_dirty(page); |
31143d5d DH |
219 | if (PageDirty(page)) |
220 | _debug("dirtied"); | |
afae457d DH |
221 | ret = copied; |
222 | ||
223 | out: | |
15b4650e | 224 | unlock_page(page); |
09cbfeaf | 225 | put_page(page); |
afae457d | 226 | return ret; |
31143d5d DH |
227 | } |
228 | ||
229 | /* | |
230 | * kill all the pages in the given range | |
231 | */ | |
4343d008 | 232 | static void afs_kill_pages(struct address_space *mapping, |
31143d5d DH |
233 | pgoff_t first, pgoff_t last) |
234 | { | |
4343d008 | 235 | struct afs_vnode *vnode = AFS_FS_I(mapping->host); |
31143d5d DH |
236 | struct pagevec pv; |
237 | unsigned count, loop; | |
238 | ||
3b6492df | 239 | _enter("{%llx:%llu},%lx-%lx", |
31143d5d DH |
240 | vnode->fid.vid, vnode->fid.vnode, first, last); |
241 | ||
86679820 | 242 | pagevec_init(&pv); |
31143d5d DH |
243 | |
244 | do { | |
245 | _debug("kill %lx-%lx", first, last); | |
246 | ||
247 | count = last - first + 1; | |
248 | if (count > PAGEVEC_SIZE) | |
249 | count = PAGEVEC_SIZE; | |
4343d008 | 250 | pv.nr = find_get_pages_contig(mapping, first, count, pv.pages); |
31143d5d DH |
251 | ASSERTCMP(pv.nr, ==, count); |
252 | ||
253 | for (loop = 0; loop < count; loop++) { | |
7286a35e DH |
254 | struct page *page = pv.pages[loop]; |
255 | ClearPageUptodate(page); | |
4343d008 DH |
256 | SetPageError(page); |
257 | end_page_writeback(page); | |
7286a35e DH |
258 | if (page->index >= first) |
259 | first = page->index + 1; | |
4343d008 DH |
260 | lock_page(page); |
261 | generic_error_remove_page(mapping, page); | |
21bd68f1 | 262 | unlock_page(page); |
31143d5d DH |
263 | } |
264 | ||
265 | __pagevec_release(&pv); | |
4343d008 | 266 | } while (first <= last); |
31143d5d DH |
267 | |
268 | _leave(""); | |
269 | } | |
270 | ||
271 | /* | |
4343d008 DH |
272 | * Redirty all the pages in a given range. |
273 | */ | |
274 | static void afs_redirty_pages(struct writeback_control *wbc, | |
275 | struct address_space *mapping, | |
276 | pgoff_t first, pgoff_t last) | |
277 | { | |
278 | struct afs_vnode *vnode = AFS_FS_I(mapping->host); | |
279 | struct pagevec pv; | |
280 | unsigned count, loop; | |
281 | ||
3b6492df | 282 | _enter("{%llx:%llu},%lx-%lx", |
4343d008 DH |
283 | vnode->fid.vid, vnode->fid.vnode, first, last); |
284 | ||
487e2c9f | 285 | pagevec_init(&pv); |
4343d008 DH |
286 | |
287 | do { | |
288 | _debug("redirty %lx-%lx", first, last); | |
289 | ||
290 | count = last - first + 1; | |
291 | if (count > PAGEVEC_SIZE) | |
292 | count = PAGEVEC_SIZE; | |
293 | pv.nr = find_get_pages_contig(mapping, first, count, pv.pages); | |
294 | ASSERTCMP(pv.nr, ==, count); | |
295 | ||
296 | for (loop = 0; loop < count; loop++) { | |
297 | struct page *page = pv.pages[loop]; | |
298 | ||
299 | redirty_page_for_writepage(wbc, page); | |
300 | end_page_writeback(page); | |
301 | if (page->index >= first) | |
302 | first = page->index + 1; | |
303 | } | |
304 | ||
305 | __pagevec_release(&pv); | |
306 | } while (first <= last); | |
31143d5d DH |
307 | |
308 | _leave(""); | |
309 | } | |
310 | ||
a58823ac DH |
311 | /* |
312 | * completion of write to server | |
313 | */ | |
314 | static void afs_pages_written_back(struct afs_vnode *vnode, | |
315 | pgoff_t first, pgoff_t last) | |
316 | { | |
317 | struct pagevec pv; | |
318 | unsigned long priv; | |
319 | unsigned count, loop; | |
320 | ||
321 | _enter("{%llx:%llu},{%lx-%lx}", | |
322 | vnode->fid.vid, vnode->fid.vnode, first, last); | |
323 | ||
324 | pagevec_init(&pv); | |
325 | ||
326 | do { | |
327 | _debug("done %lx-%lx", first, last); | |
328 | ||
329 | count = last - first + 1; | |
330 | if (count > PAGEVEC_SIZE) | |
331 | count = PAGEVEC_SIZE; | |
332 | pv.nr = find_get_pages_contig(vnode->vfs_inode.i_mapping, | |
333 | first, count, pv.pages); | |
334 | ASSERTCMP(pv.nr, ==, count); | |
335 | ||
336 | for (loop = 0; loop < count; loop++) { | |
337 | priv = page_private(pv.pages[loop]); | |
338 | trace_afs_page_dirty(vnode, tracepoint_string("clear"), | |
339 | pv.pages[loop]->index, priv); | |
340 | set_page_private(pv.pages[loop], 0); | |
341 | end_page_writeback(pv.pages[loop]); | |
342 | } | |
343 | first += count; | |
344 | __pagevec_release(&pv); | |
345 | } while (first <= last); | |
346 | ||
347 | afs_prune_wb_keys(vnode); | |
348 | _leave(""); | |
349 | } | |
350 | ||
d2ddc776 DH |
351 | /* |
352 | * write to a file | |
353 | */ | |
4343d008 DH |
354 | static int afs_store_data(struct address_space *mapping, |
355 | pgoff_t first, pgoff_t last, | |
d2ddc776 DH |
356 | unsigned offset, unsigned to) |
357 | { | |
4343d008 | 358 | struct afs_vnode *vnode = AFS_FS_I(mapping->host); |
d2ddc776 | 359 | struct afs_fs_cursor fc; |
a58823ac | 360 | struct afs_status_cb *scb; |
4343d008 DH |
361 | struct afs_wb_key *wbk = NULL; |
362 | struct list_head *p; | |
363 | int ret = -ENOKEY, ret2; | |
d2ddc776 | 364 | |
3b6492df | 365 | _enter("%s{%llx:%llu.%u},%lx,%lx,%x,%x", |
d2ddc776 DH |
366 | vnode->volume->name, |
367 | vnode->fid.vid, | |
368 | vnode->fid.vnode, | |
369 | vnode->fid.unique, | |
d2ddc776 DH |
370 | first, last, offset, to); |
371 | ||
a58823ac DH |
372 | scb = kzalloc(sizeof(struct afs_status_cb), GFP_NOFS); |
373 | if (!scb) | |
374 | return -ENOMEM; | |
375 | ||
4343d008 DH |
376 | spin_lock(&vnode->wb_lock); |
377 | p = vnode->wb_keys.next; | |
378 | ||
379 | /* Iterate through the list looking for a valid key to use. */ | |
380 | try_next_key: | |
381 | while (p != &vnode->wb_keys) { | |
382 | wbk = list_entry(p, struct afs_wb_key, vnode_link); | |
383 | _debug("wbk %u", key_serial(wbk->key)); | |
384 | ret2 = key_validate(wbk->key); | |
385 | if (ret2 == 0) | |
386 | goto found_key; | |
387 | if (ret == -ENOKEY) | |
388 | ret = ret2; | |
389 | p = p->next; | |
390 | } | |
391 | ||
392 | spin_unlock(&vnode->wb_lock); | |
393 | afs_put_wb_key(wbk); | |
a58823ac | 394 | kfree(scb); |
4343d008 DH |
395 | _leave(" = %d [no keys]", ret); |
396 | return ret; | |
397 | ||
398 | found_key: | |
399 | refcount_inc(&wbk->usage); | |
400 | spin_unlock(&vnode->wb_lock); | |
401 | ||
402 | _debug("USE WB KEY %u", key_serial(wbk->key)); | |
403 | ||
d2ddc776 | 404 | ret = -ERESTARTSYS; |
20b8391f | 405 | if (afs_begin_vnode_operation(&fc, vnode, wbk->key, false)) { |
a58823ac DH |
406 | afs_dataversion_t data_version = vnode->status.data_version + 1; |
407 | ||
d2ddc776 | 408 | while (afs_select_fileserver(&fc)) { |
68251f0a | 409 | fc.cb_break = afs_calc_vnode_cb_break(vnode); |
a58823ac | 410 | afs_fs_store_data(&fc, mapping, first, last, offset, to, scb); |
d2ddc776 DH |
411 | } |
412 | ||
a58823ac DH |
413 | afs_check_for_remote_deletion(&fc, vnode); |
414 | afs_vnode_commit_status(&fc, vnode, fc.cb_break, | |
415 | &data_version, scb); | |
416 | if (fc.ac.error == 0) | |
417 | afs_pages_written_back(vnode, first, last); | |
d2ddc776 DH |
418 | ret = afs_end_vnode_operation(&fc); |
419 | } | |
420 | ||
4343d008 | 421 | switch (ret) { |
76a5cb6f DH |
422 | case 0: |
423 | afs_stat_v(vnode, n_stores); | |
424 | atomic_long_add((last * PAGE_SIZE + to) - | |
425 | (first * PAGE_SIZE + offset), | |
426 | &afs_v2net(vnode)->n_store_bytes); | |
427 | break; | |
4343d008 DH |
428 | case -EACCES: |
429 | case -EPERM: | |
430 | case -ENOKEY: | |
431 | case -EKEYEXPIRED: | |
432 | case -EKEYREJECTED: | |
433 | case -EKEYREVOKED: | |
434 | _debug("next"); | |
435 | spin_lock(&vnode->wb_lock); | |
436 | p = wbk->vnode_link.next; | |
437 | afs_put_wb_key(wbk); | |
438 | goto try_next_key; | |
439 | } | |
440 | ||
441 | afs_put_wb_key(wbk); | |
a58823ac | 442 | kfree(scb); |
d2ddc776 DH |
443 | _leave(" = %d", ret); |
444 | return ret; | |
445 | } | |
446 | ||
31143d5d | 447 | /* |
4343d008 DH |
448 | * Synchronously write back the locked page and any subsequent non-locked dirty |
449 | * pages. | |
31143d5d | 450 | */ |
4343d008 DH |
451 | static int afs_write_back_from_locked_page(struct address_space *mapping, |
452 | struct writeback_control *wbc, | |
453 | struct page *primary_page, | |
454 | pgoff_t final_page) | |
31143d5d | 455 | { |
13524ab3 | 456 | struct afs_vnode *vnode = AFS_FS_I(mapping->host); |
31143d5d | 457 | struct page *pages[8], *page; |
4343d008 DH |
458 | unsigned long count, priv; |
459 | unsigned n, offset, to, f, t; | |
31143d5d DH |
460 | pgoff_t start, first, last; |
461 | int loop, ret; | |
462 | ||
463 | _enter(",%lx", primary_page->index); | |
464 | ||
465 | count = 1; | |
31143d5d DH |
466 | if (test_set_page_writeback(primary_page)) |
467 | BUG(); | |
468 | ||
4343d008 DH |
469 | /* Find all consecutive lockable dirty pages that have contiguous |
470 | * written regions, stopping when we find a page that is not | |
471 | * immediately lockable, is not dirty or is missing, or we reach the | |
472 | * end of the range. | |
473 | */ | |
31143d5d | 474 | start = primary_page->index; |
4343d008 DH |
475 | priv = page_private(primary_page); |
476 | offset = priv & AFS_PRIV_MAX; | |
477 | to = priv >> AFS_PRIV_SHIFT; | |
13524ab3 DH |
478 | trace_afs_page_dirty(vnode, tracepoint_string("store"), |
479 | primary_page->index, priv); | |
4343d008 DH |
480 | |
481 | WARN_ON(offset == to); | |
13524ab3 DH |
482 | if (offset == to) |
483 | trace_afs_page_dirty(vnode, tracepoint_string("WARN"), | |
484 | primary_page->index, priv); | |
4343d008 | 485 | |
5a813276 DH |
486 | if (start >= final_page || |
487 | (to < PAGE_SIZE && !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags))) | |
31143d5d | 488 | goto no_more; |
4343d008 | 489 | |
31143d5d DH |
490 | start++; |
491 | do { | |
492 | _debug("more %lx [%lx]", start, count); | |
4343d008 | 493 | n = final_page - start + 1; |
31143d5d DH |
494 | if (n > ARRAY_SIZE(pages)) |
495 | n = ARRAY_SIZE(pages); | |
4343d008 | 496 | n = find_get_pages_contig(mapping, start, ARRAY_SIZE(pages), pages); |
31143d5d DH |
497 | _debug("fgpc %u", n); |
498 | if (n == 0) | |
499 | goto no_more; | |
500 | if (pages[0]->index != start) { | |
9d577b6a DH |
501 | do { |
502 | put_page(pages[--n]); | |
503 | } while (n > 0); | |
31143d5d DH |
504 | goto no_more; |
505 | } | |
506 | ||
507 | for (loop = 0; loop < n; loop++) { | |
508 | page = pages[loop]; | |
5a813276 DH |
509 | if (to != PAGE_SIZE && |
510 | !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)) | |
511 | break; | |
4343d008 | 512 | if (page->index > final_page) |
31143d5d | 513 | break; |
529ae9aa | 514 | if (!trylock_page(page)) |
31143d5d | 515 | break; |
4343d008 | 516 | if (!PageDirty(page) || PageWriteback(page)) { |
31143d5d DH |
517 | unlock_page(page); |
518 | break; | |
519 | } | |
4343d008 DH |
520 | |
521 | priv = page_private(page); | |
522 | f = priv & AFS_PRIV_MAX; | |
523 | t = priv >> AFS_PRIV_SHIFT; | |
5a813276 DH |
524 | if (f != 0 && |
525 | !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)) { | |
31143d5d DH |
526 | unlock_page(page); |
527 | break; | |
528 | } | |
4343d008 DH |
529 | to = t; |
530 | ||
13524ab3 DH |
531 | trace_afs_page_dirty(vnode, tracepoint_string("store+"), |
532 | page->index, priv); | |
533 | ||
31143d5d DH |
534 | if (!clear_page_dirty_for_io(page)) |
535 | BUG(); | |
536 | if (test_set_page_writeback(page)) | |
537 | BUG(); | |
538 | unlock_page(page); | |
539 | put_page(page); | |
540 | } | |
541 | count += loop; | |
542 | if (loop < n) { | |
543 | for (; loop < n; loop++) | |
544 | put_page(pages[loop]); | |
545 | goto no_more; | |
546 | } | |
547 | ||
548 | start += loop; | |
4343d008 | 549 | } while (start <= final_page && count < 65536); |
31143d5d DH |
550 | |
551 | no_more: | |
4343d008 DH |
552 | /* We now have a contiguous set of dirty pages, each with writeback |
553 | * set; the first page is still locked at this point, but all the rest | |
554 | * have been unlocked. | |
555 | */ | |
556 | unlock_page(primary_page); | |
557 | ||
31143d5d DH |
558 | first = primary_page->index; |
559 | last = first + count - 1; | |
560 | ||
31143d5d DH |
561 | _debug("write back %lx[%u..] to %lx[..%u]", first, offset, last, to); |
562 | ||
4343d008 DH |
563 | ret = afs_store_data(mapping, first, last, offset, to); |
564 | switch (ret) { | |
565 | case 0: | |
31143d5d | 566 | ret = count; |
4343d008 DH |
567 | break; |
568 | ||
569 | default: | |
570 | pr_notice("kAFS: Unexpected error from FS.StoreData %d\n", ret); | |
571 | /* Fall through */ | |
572 | case -EACCES: | |
573 | case -EPERM: | |
574 | case -ENOKEY: | |
575 | case -EKEYEXPIRED: | |
576 | case -EKEYREJECTED: | |
577 | case -EKEYREVOKED: | |
578 | afs_redirty_pages(wbc, mapping, first, last); | |
579 | mapping_set_error(mapping, ret); | |
580 | break; | |
581 | ||
582 | case -EDQUOT: | |
583 | case -ENOSPC: | |
584 | afs_redirty_pages(wbc, mapping, first, last); | |
585 | mapping_set_error(mapping, -ENOSPC); | |
586 | break; | |
587 | ||
588 | case -EROFS: | |
589 | case -EIO: | |
590 | case -EREMOTEIO: | |
591 | case -EFBIG: | |
592 | case -ENOENT: | |
593 | case -ENOMEDIUM: | |
594 | case -ENXIO: | |
f51375cd | 595 | trace_afs_file_error(vnode, ret, afs_file_error_writeback_fail); |
4343d008 DH |
596 | afs_kill_pages(mapping, first, last); |
597 | mapping_set_error(mapping, ret); | |
598 | break; | |
31143d5d DH |
599 | } |
600 | ||
601 | _leave(" = %d", ret); | |
602 | return ret; | |
603 | } | |
604 | ||
605 | /* | |
606 | * write a page back to the server | |
607 | * - the caller locked the page for us | |
608 | */ | |
609 | int afs_writepage(struct page *page, struct writeback_control *wbc) | |
610 | { | |
31143d5d DH |
611 | int ret; |
612 | ||
613 | _enter("{%lx},", page->index); | |
614 | ||
4343d008 DH |
615 | ret = afs_write_back_from_locked_page(page->mapping, wbc, page, |
616 | wbc->range_end >> PAGE_SHIFT); | |
31143d5d DH |
617 | if (ret < 0) { |
618 | _leave(" = %d", ret); | |
619 | return 0; | |
620 | } | |
621 | ||
622 | wbc->nr_to_write -= ret; | |
31143d5d DH |
623 | |
624 | _leave(" = 0"); | |
625 | return 0; | |
626 | } | |
627 | ||
628 | /* | |
629 | * write a region of pages back to the server | |
630 | */ | |
c1206a2c AB |
631 | static int afs_writepages_region(struct address_space *mapping, |
632 | struct writeback_control *wbc, | |
633 | pgoff_t index, pgoff_t end, pgoff_t *_next) | |
31143d5d | 634 | { |
31143d5d DH |
635 | struct page *page; |
636 | int ret, n; | |
637 | ||
638 | _enter(",,%lx,%lx,", index, end); | |
639 | ||
640 | do { | |
aef6e415 JK |
641 | n = find_get_pages_range_tag(mapping, &index, end, |
642 | PAGECACHE_TAG_DIRTY, 1, &page); | |
31143d5d DH |
643 | if (!n) |
644 | break; | |
645 | ||
646 | _debug("wback %lx", page->index); | |
647 | ||
b93b0163 MW |
648 | /* |
649 | * at this point we hold neither the i_pages lock nor the | |
650 | * page lock: the page may be truncated or invalidated | |
651 | * (changing page->mapping to NULL), or even swizzled | |
652 | * back from swapper_space to tmpfs file mapping | |
31143d5d | 653 | */ |
4343d008 DH |
654 | ret = lock_page_killable(page); |
655 | if (ret < 0) { | |
656 | put_page(page); | |
657 | _leave(" = %d", ret); | |
658 | return ret; | |
659 | } | |
31143d5d | 660 | |
c5051c7b | 661 | if (page->mapping != mapping || !PageDirty(page)) { |
31143d5d | 662 | unlock_page(page); |
09cbfeaf | 663 | put_page(page); |
31143d5d DH |
664 | continue; |
665 | } | |
666 | ||
c5051c7b | 667 | if (PageWriteback(page)) { |
31143d5d | 668 | unlock_page(page); |
c5051c7b DH |
669 | if (wbc->sync_mode != WB_SYNC_NONE) |
670 | wait_on_page_writeback(page); | |
29c8bbbd | 671 | put_page(page); |
31143d5d DH |
672 | continue; |
673 | } | |
674 | ||
65a15109 DH |
675 | if (!clear_page_dirty_for_io(page)) |
676 | BUG(); | |
4343d008 | 677 | ret = afs_write_back_from_locked_page(mapping, wbc, page, end); |
09cbfeaf | 678 | put_page(page); |
31143d5d DH |
679 | if (ret < 0) { |
680 | _leave(" = %d", ret); | |
681 | return ret; | |
682 | } | |
683 | ||
684 | wbc->nr_to_write -= ret; | |
685 | ||
31143d5d DH |
686 | cond_resched(); |
687 | } while (index < end && wbc->nr_to_write > 0); | |
688 | ||
689 | *_next = index; | |
690 | _leave(" = 0 [%lx]", *_next); | |
691 | return 0; | |
692 | } | |
693 | ||
694 | /* | |
695 | * write some of the pending data back to the server | |
696 | */ | |
697 | int afs_writepages(struct address_space *mapping, | |
698 | struct writeback_control *wbc) | |
699 | { | |
31143d5d DH |
700 | pgoff_t start, end, next; |
701 | int ret; | |
702 | ||
703 | _enter(""); | |
704 | ||
31143d5d DH |
705 | if (wbc->range_cyclic) { |
706 | start = mapping->writeback_index; | |
707 | end = -1; | |
708 | ret = afs_writepages_region(mapping, wbc, start, end, &next); | |
1b430bee | 709 | if (start > 0 && wbc->nr_to_write > 0 && ret == 0) |
31143d5d DH |
710 | ret = afs_writepages_region(mapping, wbc, 0, start, |
711 | &next); | |
712 | mapping->writeback_index = next; | |
713 | } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) { | |
09cbfeaf | 714 | end = (pgoff_t)(LLONG_MAX >> PAGE_SHIFT); |
31143d5d DH |
715 | ret = afs_writepages_region(mapping, wbc, 0, end, &next); |
716 | if (wbc->nr_to_write > 0) | |
717 | mapping->writeback_index = next; | |
718 | } else { | |
09cbfeaf KS |
719 | start = wbc->range_start >> PAGE_SHIFT; |
720 | end = wbc->range_end >> PAGE_SHIFT; | |
31143d5d DH |
721 | ret = afs_writepages_region(mapping, wbc, start, end, &next); |
722 | } | |
723 | ||
724 | _leave(" = %d", ret); | |
725 | return ret; | |
726 | } | |
727 | ||
31143d5d DH |
728 | /* |
729 | * write to an AFS file | |
730 | */ | |
50b5551d | 731 | ssize_t afs_file_write(struct kiocb *iocb, struct iov_iter *from) |
31143d5d | 732 | { |
496ad9aa | 733 | struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp)); |
31143d5d | 734 | ssize_t result; |
50b5551d | 735 | size_t count = iov_iter_count(from); |
31143d5d | 736 | |
3b6492df | 737 | _enter("{%llx:%llu},{%zu},", |
50b5551d | 738 | vnode->fid.vid, vnode->fid.vnode, count); |
31143d5d DH |
739 | |
740 | if (IS_SWAPFILE(&vnode->vfs_inode)) { | |
741 | printk(KERN_INFO | |
742 | "AFS: Attempt to write to active swap file!\n"); | |
743 | return -EBUSY; | |
744 | } | |
745 | ||
746 | if (!count) | |
747 | return 0; | |
748 | ||
50b5551d | 749 | result = generic_file_write_iter(iocb, from); |
31143d5d | 750 | |
31143d5d DH |
751 | _leave(" = %zd", result); |
752 | return result; | |
753 | } | |
754 | ||
31143d5d DH |
755 | /* |
756 | * flush any dirty pages for this process, and check for write errors. | |
757 | * - the return status from this call provides a reliable indication of | |
758 | * whether any write errors occurred for this process. | |
759 | */ | |
02c24a82 | 760 | int afs_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
31143d5d | 761 | { |
3c981bfc | 762 | struct inode *inode = file_inode(file); |
3c981bfc | 763 | struct afs_vnode *vnode = AFS_FS_I(inode); |
31143d5d | 764 | |
3b6492df | 765 | _enter("{%llx:%llu},{n=%pD},%d", |
3c981bfc | 766 | vnode->fid.vid, vnode->fid.vnode, file, |
31143d5d DH |
767 | datasync); |
768 | ||
4343d008 | 769 | return file_write_and_wait_range(file, start, end); |
31143d5d | 770 | } |
9b3f26c9 DH |
771 | |
772 | /* | |
773 | * notification that a previously read-only page is about to become writable | |
774 | * - if it returns an error, the caller will deliver a bus error signal | |
775 | */ | |
0722f186 | 776 | vm_fault_t afs_page_mkwrite(struct vm_fault *vmf) |
9b3f26c9 | 777 | { |
1cf7a151 DH |
778 | struct file *file = vmf->vma->vm_file; |
779 | struct inode *inode = file_inode(file); | |
780 | struct afs_vnode *vnode = AFS_FS_I(inode); | |
781 | unsigned long priv; | |
9b3f26c9 | 782 | |
3b6492df | 783 | _enter("{{%llx:%llu}},{%lx}", |
1cf7a151 | 784 | vnode->fid.vid, vnode->fid.vnode, vmf->page->index); |
9b3f26c9 | 785 | |
1cf7a151 | 786 | sb_start_pagefault(inode->i_sb); |
9b3f26c9 | 787 | |
1cf7a151 DH |
788 | /* Wait for the page to be written to the cache before we allow it to |
789 | * be modified. We then assume the entire page will need writing back. | |
790 | */ | |
9b3f26c9 | 791 | #ifdef CONFIG_AFS_FSCACHE |
1cf7a151 | 792 | fscache_wait_on_page_write(vnode->cache, vmf->page); |
9b3f26c9 DH |
793 | #endif |
794 | ||
1cf7a151 DH |
795 | if (PageWriteback(vmf->page) && |
796 | wait_on_page_bit_killable(vmf->page, PG_writeback) < 0) | |
797 | return VM_FAULT_RETRY; | |
798 | ||
799 | if (lock_page_killable(vmf->page) < 0) | |
800 | return VM_FAULT_RETRY; | |
801 | ||
802 | /* We mustn't change page->private until writeback is complete as that | |
803 | * details the portion of the page we need to write back and we might | |
804 | * need to redirty the page if there's a problem. | |
805 | */ | |
806 | wait_on_page_writeback(vmf->page); | |
807 | ||
808 | priv = (unsigned long)PAGE_SIZE << AFS_PRIV_SHIFT; /* To */ | |
809 | priv |= 0; /* From */ | |
13524ab3 DH |
810 | trace_afs_page_dirty(vnode, tracepoint_string("mkwrite"), |
811 | vmf->page->index, priv); | |
1cf7a151 DH |
812 | SetPagePrivate(vmf->page); |
813 | set_page_private(vmf->page, priv); | |
814 | ||
815 | sb_end_pagefault(inode->i_sb); | |
816 | return VM_FAULT_LOCKED; | |
9b3f26c9 | 817 | } |
4343d008 DH |
818 | |
819 | /* | |
820 | * Prune the keys cached for writeback. The caller must hold vnode->wb_lock. | |
821 | */ | |
822 | void afs_prune_wb_keys(struct afs_vnode *vnode) | |
823 | { | |
824 | LIST_HEAD(graveyard); | |
825 | struct afs_wb_key *wbk, *tmp; | |
826 | ||
827 | /* Discard unused keys */ | |
828 | spin_lock(&vnode->wb_lock); | |
829 | ||
830 | if (!mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_WRITEBACK) && | |
831 | !mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_DIRTY)) { | |
832 | list_for_each_entry_safe(wbk, tmp, &vnode->wb_keys, vnode_link) { | |
833 | if (refcount_read(&wbk->usage) == 1) | |
834 | list_move(&wbk->vnode_link, &graveyard); | |
835 | } | |
836 | } | |
837 | ||
838 | spin_unlock(&vnode->wb_lock); | |
839 | ||
840 | while (!list_empty(&graveyard)) { | |
841 | wbk = list_entry(graveyard.next, struct afs_wb_key, vnode_link); | |
842 | list_del(&wbk->vnode_link); | |
843 | afs_put_wb_key(wbk); | |
844 | } | |
845 | } | |
846 | ||
847 | /* | |
848 | * Clean up a page during invalidation. | |
849 | */ | |
850 | int afs_launder_page(struct page *page) | |
851 | { | |
852 | struct address_space *mapping = page->mapping; | |
853 | struct afs_vnode *vnode = AFS_FS_I(mapping->host); | |
854 | unsigned long priv; | |
855 | unsigned int f, t; | |
856 | int ret = 0; | |
857 | ||
858 | _enter("{%lx}", page->index); | |
859 | ||
860 | priv = page_private(page); | |
861 | if (clear_page_dirty_for_io(page)) { | |
862 | f = 0; | |
863 | t = PAGE_SIZE; | |
864 | if (PagePrivate(page)) { | |
865 | f = priv & AFS_PRIV_MAX; | |
866 | t = priv >> AFS_PRIV_SHIFT; | |
867 | } | |
868 | ||
13524ab3 DH |
869 | trace_afs_page_dirty(vnode, tracepoint_string("launder"), |
870 | page->index, priv); | |
4343d008 DH |
871 | ret = afs_store_data(mapping, page->index, page->index, t, f); |
872 | } | |
873 | ||
13524ab3 DH |
874 | trace_afs_page_dirty(vnode, tracepoint_string("laundered"), |
875 | page->index, priv); | |
4343d008 DH |
876 | set_page_private(page, 0); |
877 | ClearPagePrivate(page); | |
878 | ||
879 | #ifdef CONFIG_AFS_FSCACHE | |
880 | if (PageFsCache(page)) { | |
881 | fscache_wait_on_page_write(vnode->cache, page); | |
882 | fscache_uncache_page(vnode->cache, page); | |
883 | } | |
884 | #endif | |
885 | return ret; | |
9b3f26c9 | 886 | } |