blob: 4b2265cb18917b5e28078b9b61ca098fab6139a8 [file] [log] [blame]
Thomas Gleixner2874c5f2019-05-27 08:55:01 +02001// SPDX-License-Identifier: GPL-2.0-or-later
David Howells31143d52007-05-09 02:33:46 -07002/* 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)
David Howells31143d52007-05-09 02:33:46 -07006 */
David Howells4343d002017-11-02 15:27:52 +00007
Alexey Dobriyan4af3c9c2007-10-16 23:29:23 -07008#include <linux/backing-dev.h>
David Howells31143d52007-05-09 02:33:46 -07009#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
David Howells31143d52007-05-09 02:33:46 -070016/*
17 * mark a page as having been made dirty and thus needing writeback
18 */
19int afs_set_page_dirty(struct page *page)
20{
21 _enter("");
22 return __set_page_dirty_nobuffers(page);
23}
24
25/*
David Howells31143d52007-05-09 02:33:46 -070026 * partly or wholly fill a page that's under preparation for writing
27 */
28static int afs_fill_page(struct afs_vnode *vnode, struct key *key,
David Howellse8e581a2017-03-16 16:27:44 +000029 loff_t pos, unsigned int len, struct page *page)
David Howells31143d52007-05-09 02:33:46 -070030{
David Howells196ee9c2017-01-05 10:38:34 +000031 struct afs_read *req;
David Howells2a0b4f62018-10-20 00:57:57 +010032 size_t p;
33 void *data;
David Howells31143d52007-05-09 02:33:46 -070034 int ret;
35
Anton Blanchard5e7f2332011-06-13 22:31:12 +010036 _enter(",,%llu", (unsigned long long)pos);
David Howells31143d52007-05-09 02:33:46 -070037
David Howells2a0b4f62018-10-20 00:57:57 +010038 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
Zhengyuan Liuee102582019-06-20 18:12:17 +010047 req = kzalloc(struct_size(req, array, 1), GFP_KERNEL);
David Howells196ee9c2017-01-05 10:38:34 +000048 if (!req)
49 return -ENOMEM;
50
David Howellsf3ddee82018-04-06 14:17:25 +010051 refcount_set(&req->usage, 1);
David Howells196ee9c2017-01-05 10:38:34 +000052 req->pos = pos;
David Howellse8e581a2017-03-16 16:27:44 +000053 req->len = len;
David Howells196ee9c2017-01-05 10:38:34 +000054 req->nr_pages = 1;
David Howellsf3ddee82018-04-06 14:17:25 +010055 req->pages = req->array;
David Howells196ee9c2017-01-05 10:38:34 +000056 req->pages[0] = page;
David Howells5611ef22017-03-16 16:27:43 +000057 get_page(page);
David Howells196ee9c2017-01-05 10:38:34 +000058
David Howellsd2ddc772017-11-02 15:27:50 +000059 ret = afs_fetch_data(vnode, key, req);
David Howells196ee9c2017-01-05 10:38:34 +000060 afs_put_read(req);
David Howells31143d52007-05-09 02:33:46 -070061 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
74/*
David Howells31143d52007-05-09 02:33:46 -070075 * prepare to perform part of a write to a page
David Howells31143d52007-05-09 02:33:46 -070076 */
Nick Piggin15b46502008-10-15 22:04:32 -070077int afs_write_begin(struct file *file, struct address_space *mapping,
78 loff_t pos, unsigned len, unsigned flags,
79 struct page **pagep, void **fsdata)
David Howells31143d52007-05-09 02:33:46 -070080{
Al Viro496ad9a2013-01-23 17:07:38 -050081 struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
Nick Piggin15b46502008-10-15 22:04:32 -070082 struct page *page;
David Howells215804a2017-11-02 15:27:52 +000083 struct key *key = afs_file_key(file);
David Howells4343d002017-11-02 15:27:52 +000084 unsigned long priv;
85 unsigned f, from = pos & (PAGE_SIZE - 1);
86 unsigned t, to = from + len;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +030087 pgoff_t index = pos >> PAGE_SHIFT;
David Howells31143d52007-05-09 02:33:46 -070088 int ret;
89
David Howells3b6492d2018-10-20 00:57:57 +010090 _enter("{%llx:%llu},{%lx},%u,%u",
Nick Piggin15b46502008-10-15 22:04:32 -070091 vnode->fid.vid, vnode->fid.vnode, index, from, to);
David Howells31143d52007-05-09 02:33:46 -070092
David Howells4343d002017-11-02 15:27:52 +000093 /* 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);
David Howells31143d52007-05-09 02:33:46 -070097
Nick Piggin54566b22009-01-04 12:00:53 -080098 page = grab_cache_page_write_begin(mapping, index, flags);
David Howells4343d002017-11-02 15:27:52 +000099 if (!page)
Nick Piggin15b46502008-10-15 22:04:32 -0700100 return -ENOMEM;
Nick Piggin15b46502008-10-15 22:04:32 -0700101
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300102 if (!PageUptodate(page) && len != PAGE_SIZE) {
David Howellse8e581a2017-03-16 16:27:44 +0000103 ret = afs_fill_page(vnode, key, pos & PAGE_MASK, PAGE_SIZE, page);
David Howells31143d52007-05-09 02:33:46 -0700104 if (ret < 0) {
David Howells6d06b0d2017-03-16 16:27:48 +0000105 unlock_page(page);
106 put_page(page);
David Howells31143d52007-05-09 02:33:46 -0700107 _leave(" = %d [prep]", ret);
108 return ret;
109 }
Nick Piggin15b46502008-10-15 22:04:32 -0700110 SetPageUptodate(page);
David Howells31143d52007-05-09 02:33:46 -0700111 }
112
David Howells6d06b0d2017-03-16 16:27:48 +0000113 /* page won't leak in error case: it eventually gets cleaned off LRU */
114 *pagep = page;
115
David Howells31143d52007-05-09 02:33:46 -0700116try_again:
David Howells4343d002017-11-02 15:27:52 +0000117 /* 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);
David Howells31143d52007-05-09 02:33:46 -0700126 }
127
David Howells4343d002017-11-02 15:27:52 +0000128 if (f != t) {
David Howells5a039c32017-11-18 00:13:30 +0000129 if (PageWriteback(page)) {
130 trace_afs_page_dirty(vnode, tracepoint_string("alrdy"),
131 page->index, priv);
132 goto flush_conflicting_write;
133 }
David Howells5a813272018-04-06 14:17:26 +0100134 /* 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))
David Howells4343d002017-11-02 15:27:52 +0000140 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;
David Howells31143d52007-05-09 02:33:46 -0700148 }
149
David Howells4343d002017-11-02 15:27:52 +0000150 priv = (unsigned long)t << AFS_PRIV_SHIFT;
151 priv |= f;
David Howells13524ab2017-11-02 15:27:53 +0000152 trace_afs_page_dirty(vnode, tracepoint_string("begin"),
153 page->index, priv);
David Howells31143d52007-05-09 02:33:46 -0700154 SetPagePrivate(page);
David Howells4343d002017-11-02 15:27:52 +0000155 set_page_private(page, priv);
156 _leave(" = 0");
David Howells31143d52007-05-09 02:33:46 -0700157 return 0;
158
David Howells4343d002017-11-02 15:27:52 +0000159 /* The previous write and this write aren't adjacent or overlapping, so
160 * flush the page out.
161 */
162flush_conflicting_write:
David Howells31143d52007-05-09 02:33:46 -0700163 _debug("flush conflict");
David Howells4343d002017-11-02 15:27:52 +0000164 ret = write_one_page(page);
165 if (ret < 0) {
166 _leave(" = %d", ret);
167 return ret;
David Howells31143d52007-05-09 02:33:46 -0700168 }
169
David Howells4343d002017-11-02 15:27:52 +0000170 ret = lock_page_killable(page);
171 if (ret < 0) {
172 _leave(" = %d", ret);
173 return ret;
174 }
David Howells31143d52007-05-09 02:33:46 -0700175 goto try_again;
176}
177
178/*
179 * finalise part of a write to a page
180 */
Nick Piggin15b46502008-10-15 22:04:32 -0700181int afs_write_end(struct file *file, struct address_space *mapping,
182 loff_t pos, unsigned len, unsigned copied,
183 struct page *page, void *fsdata)
David Howells31143d52007-05-09 02:33:46 -0700184{
Al Viro496ad9a2013-01-23 17:07:38 -0500185 struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
David Howells215804a2017-11-02 15:27:52 +0000186 struct key *key = afs_file_key(file);
David Howells31143d52007-05-09 02:33:46 -0700187 loff_t i_size, maybe_i_size;
David Howellse8e581a2017-03-16 16:27:44 +0000188 int ret;
David Howells31143d52007-05-09 02:33:46 -0700189
David Howells3b6492d2018-10-20 00:57:57 +0100190 _enter("{%llx:%llu},{%lx}",
Nick Piggin15b46502008-10-15 22:04:32 -0700191 vnode->fid.vid, vnode->fid.vnode, page->index);
David Howells31143d52007-05-09 02:33:46 -0700192
Nick Piggin15b46502008-10-15 22:04:32 -0700193 maybe_i_size = pos + copied;
David Howells31143d52007-05-09 02:33:46 -0700194
195 i_size = i_size_read(&vnode->vfs_inode);
196 if (maybe_i_size > i_size) {
David Howells1f32ef72020-06-12 23:58:51 +0100197 write_seqlock(&vnode->cb_lock);
David Howells31143d52007-05-09 02:33:46 -0700198 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);
David Howells1f32ef72020-06-12 23:58:51 +0100201 write_sequnlock(&vnode->cb_lock);
David Howells31143d52007-05-09 02:33:46 -0700202 }
203
David Howellse8e581a2017-03-16 16:27:44 +0000204 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)
David Howellsafae4572018-01-02 10:02:19 +0000213 goto out;
David Howellse8e581a2017-03-16 16:27:44 +0000214 }
215 SetPageUptodate(page);
216 }
217
David Howells31143d52007-05-09 02:33:46 -0700218 set_page_dirty(page);
David Howells31143d52007-05-09 02:33:46 -0700219 if (PageDirty(page))
220 _debug("dirtied");
David Howellsafae4572018-01-02 10:02:19 +0000221 ret = copied;
222
223out:
Nick Piggin15b46502008-10-15 22:04:32 -0700224 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300225 put_page(page);
David Howellsafae4572018-01-02 10:02:19 +0000226 return ret;
David Howells31143d52007-05-09 02:33:46 -0700227}
228
229/*
230 * kill all the pages in the given range
231 */
David Howells4343d002017-11-02 15:27:52 +0000232static void afs_kill_pages(struct address_space *mapping,
David Howells31143d52007-05-09 02:33:46 -0700233 pgoff_t first, pgoff_t last)
234{
David Howells4343d002017-11-02 15:27:52 +0000235 struct afs_vnode *vnode = AFS_FS_I(mapping->host);
David Howells31143d52007-05-09 02:33:46 -0700236 struct pagevec pv;
237 unsigned count, loop;
238
David Howells3b6492d2018-10-20 00:57:57 +0100239 _enter("{%llx:%llu},%lx-%lx",
David Howells31143d52007-05-09 02:33:46 -0700240 vnode->fid.vid, vnode->fid.vnode, first, last);
241
Mel Gorman86679822017-11-15 17:37:52 -0800242 pagevec_init(&pv);
David Howells31143d52007-05-09 02:33:46 -0700243
244 do {
245 _debug("kill %lx-%lx", first, last);
246
247 count = last - first + 1;
248 if (count > PAGEVEC_SIZE)
249 count = PAGEVEC_SIZE;
David Howells4343d002017-11-02 15:27:52 +0000250 pv.nr = find_get_pages_contig(mapping, first, count, pv.pages);
David Howells31143d52007-05-09 02:33:46 -0700251 ASSERTCMP(pv.nr, ==, count);
252
253 for (loop = 0; loop < count; loop++) {
David Howells7286a352017-03-16 16:27:48 +0000254 struct page *page = pv.pages[loop];
255 ClearPageUptodate(page);
David Howells4343d002017-11-02 15:27:52 +0000256 SetPageError(page);
257 end_page_writeback(page);
David Howells7286a352017-03-16 16:27:48 +0000258 if (page->index >= first)
259 first = page->index + 1;
David Howells4343d002017-11-02 15:27:52 +0000260 lock_page(page);
261 generic_error_remove_page(mapping, page);
Marc Dionne21bd68f2019-04-13 08:37:37 +0100262 unlock_page(page);
David Howells31143d52007-05-09 02:33:46 -0700263 }
264
265 __pagevec_release(&pv);
David Howells4343d002017-11-02 15:27:52 +0000266 } while (first <= last);
David Howells31143d52007-05-09 02:33:46 -0700267
268 _leave("");
269}
270
271/*
David Howells4343d002017-11-02 15:27:52 +0000272 * Redirty all the pages in a given range.
David Howells31143d52007-05-09 02:33:46 -0700273 */
David Howells4343d002017-11-02 15:27:52 +0000274static void afs_redirty_pages(struct writeback_control *wbc,
275 struct address_space *mapping,
276 pgoff_t first, pgoff_t last)
David Howells31143d52007-05-09 02:33:46 -0700277{
David Howells4343d002017-11-02 15:27:52 +0000278 struct afs_vnode *vnode = AFS_FS_I(mapping->host);
279 struct pagevec pv;
280 unsigned count, loop;
281
David Howells3b6492d2018-10-20 00:57:57 +0100282 _enter("{%llx:%llu},%lx-%lx",
David Howells4343d002017-11-02 15:27:52 +0000283 vnode->fid.vid, vnode->fid.vnode, first, last);
284
Linus Torvalds487e2c92017-11-16 11:41:22 -0800285 pagevec_init(&pv);
David Howells4343d002017-11-02 15:27:52 +0000286
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);
David Howells31143d52007-05-09 02:33:46 -0700301 if (page->index >= first)
302 first = page->index + 1;
303 }
304
305 __pagevec_release(&pv);
David Howells4343d002017-11-02 15:27:52 +0000306 } while (first <= last);
David Howells31143d52007-05-09 02:33:46 -0700307
308 _leave("");
309}
310
311/*
David Howellsa58823a2019-05-09 15:16:10 +0100312 * completion of write to server
313 */
314static 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
351/*
David Howellse49c7b22020-04-10 20:51:51 +0100352 * Find a key to use for the writeback. We cached the keys used to author the
353 * writes on the vnode. *_wbk will contain the last writeback key used or NULL
354 * and we need to start from there if it's set.
355 */
356static int afs_get_writeback_key(struct afs_vnode *vnode,
357 struct afs_wb_key **_wbk)
358{
359 struct afs_wb_key *wbk = NULL;
360 struct list_head *p;
361 int ret = -ENOKEY, ret2;
362
363 spin_lock(&vnode->wb_lock);
364 if (*_wbk)
365 p = (*_wbk)->vnode_link.next;
366 else
367 p = vnode->wb_keys.next;
368
369 while (p != &vnode->wb_keys) {
370 wbk = list_entry(p, struct afs_wb_key, vnode_link);
371 _debug("wbk %u", key_serial(wbk->key));
372 ret2 = key_validate(wbk->key);
373 if (ret2 == 0) {
374 refcount_inc(&wbk->usage);
375 _debug("USE WB KEY %u", key_serial(wbk->key));
376 break;
377 }
378
379 wbk = NULL;
380 if (ret == -ENOKEY)
381 ret = ret2;
382 p = p->next;
383 }
384
385 spin_unlock(&vnode->wb_lock);
386 if (*_wbk)
387 afs_put_wb_key(*_wbk);
388 *_wbk = wbk;
389 return 0;
390}
391
392static void afs_store_data_success(struct afs_operation *op)
393{
394 struct afs_vnode *vnode = op->file[0].vnode;
395
David Howellsda8d0752020-06-13 19:34:59 +0100396 op->ctime = op->file[0].scb.status.mtime_client;
David Howellse49c7b22020-04-10 20:51:51 +0100397 afs_vnode_commit_status(op, &op->file[0]);
398 if (op->error == 0) {
399 afs_pages_written_back(vnode, op->store.first, op->store.last);
400 afs_stat_v(vnode, n_stores);
401 atomic_long_add((op->store.last * PAGE_SIZE + op->store.last_to) -
402 (op->store.first * PAGE_SIZE + op->store.first_offset),
403 &afs_v2net(vnode)->n_store_bytes);
404 }
405}
406
407static const struct afs_operation_ops afs_store_data_operation = {
408 .issue_afs_rpc = afs_fs_store_data,
409 .issue_yfs_rpc = yfs_fs_store_data,
410 .success = afs_store_data_success,
411};
412
413/*
David Howellsd2ddc772017-11-02 15:27:50 +0000414 * write to a file
415 */
David Howells4343d002017-11-02 15:27:52 +0000416static int afs_store_data(struct address_space *mapping,
417 pgoff_t first, pgoff_t last,
David Howellsd2ddc772017-11-02 15:27:50 +0000418 unsigned offset, unsigned to)
419{
David Howells4343d002017-11-02 15:27:52 +0000420 struct afs_vnode *vnode = AFS_FS_I(mapping->host);
David Howellse49c7b22020-04-10 20:51:51 +0100421 struct afs_operation *op;
David Howells4343d002017-11-02 15:27:52 +0000422 struct afs_wb_key *wbk = NULL;
David Howellse49c7b22020-04-10 20:51:51 +0100423 int ret;
David Howellsd2ddc772017-11-02 15:27:50 +0000424
David Howells3b6492d2018-10-20 00:57:57 +0100425 _enter("%s{%llx:%llu.%u},%lx,%lx,%x,%x",
David Howellsd2ddc772017-11-02 15:27:50 +0000426 vnode->volume->name,
427 vnode->fid.vid,
428 vnode->fid.vnode,
429 vnode->fid.unique,
David Howellsd2ddc772017-11-02 15:27:50 +0000430 first, last, offset, to);
431
David Howellse49c7b22020-04-10 20:51:51 +0100432 ret = afs_get_writeback_key(vnode, &wbk);
433 if (ret) {
434 _leave(" = %d [no keys]", ret);
435 return ret;
436 }
437
438 op = afs_alloc_operation(wbk->key, vnode->volume);
439 if (IS_ERR(op)) {
440 afs_put_wb_key(wbk);
David Howellsa58823a2019-05-09 15:16:10 +0100441 return -ENOMEM;
David Howellse49c7b22020-04-10 20:51:51 +0100442 }
David Howellsa58823a2019-05-09 15:16:10 +0100443
David Howellse49c7b22020-04-10 20:51:51 +0100444 afs_op_set_vnode(op, 0, vnode);
445 op->file[0].dv_delta = 1;
446 op->store.mapping = mapping;
447 op->store.first = first;
448 op->store.last = last;
449 op->store.first_offset = offset;
450 op->store.last_to = to;
David Howellsb3597942020-06-11 21:50:24 +0100451 op->mtime = vnode->vfs_inode.i_mtime;
David Howells811f04b2020-07-08 09:27:07 +0100452 op->flags |= AFS_OPERATION_UNINTR;
David Howellse49c7b22020-04-10 20:51:51 +0100453 op->ops = &afs_store_data_operation;
David Howells4343d002017-11-02 15:27:52 +0000454
David Howells4343d002017-11-02 15:27:52 +0000455try_next_key:
David Howellse49c7b22020-04-10 20:51:51 +0100456 afs_begin_vnode_operation(op);
457 afs_wait_for_operation(op);
David Howells4343d002017-11-02 15:27:52 +0000458
David Howellse49c7b22020-04-10 20:51:51 +0100459 switch (op->error) {
David Howells4343d002017-11-02 15:27:52 +0000460 case -EACCES:
461 case -EPERM:
462 case -ENOKEY:
463 case -EKEYEXPIRED:
464 case -EKEYREJECTED:
465 case -EKEYREVOKED:
466 _debug("next");
David Howellse49c7b22020-04-10 20:51:51 +0100467
468 ret = afs_get_writeback_key(vnode, &wbk);
469 if (ret == 0) {
470 key_put(op->key);
471 op->key = key_get(wbk->key);
472 goto try_next_key;
473 }
474 break;
David Howells4343d002017-11-02 15:27:52 +0000475 }
476
477 afs_put_wb_key(wbk);
David Howellse49c7b22020-04-10 20:51:51 +0100478 _leave(" = %d", op->error);
479 return afs_put_operation(op);
David Howellsd2ddc772017-11-02 15:27:50 +0000480}
481
482/*
David Howells4343d002017-11-02 15:27:52 +0000483 * Synchronously write back the locked page and any subsequent non-locked dirty
484 * pages.
David Howells31143d52007-05-09 02:33:46 -0700485 */
David Howells4343d002017-11-02 15:27:52 +0000486static int afs_write_back_from_locked_page(struct address_space *mapping,
487 struct writeback_control *wbc,
488 struct page *primary_page,
489 pgoff_t final_page)
David Howells31143d52007-05-09 02:33:46 -0700490{
David Howells13524ab2017-11-02 15:27:53 +0000491 struct afs_vnode *vnode = AFS_FS_I(mapping->host);
David Howells31143d52007-05-09 02:33:46 -0700492 struct page *pages[8], *page;
David Howells4343d002017-11-02 15:27:52 +0000493 unsigned long count, priv;
494 unsigned n, offset, to, f, t;
David Howells31143d52007-05-09 02:33:46 -0700495 pgoff_t start, first, last;
David Howells793fe822020-06-12 16:13:52 +0100496 loff_t i_size, end;
David Howells31143d52007-05-09 02:33:46 -0700497 int loop, ret;
498
499 _enter(",%lx", primary_page->index);
500
501 count = 1;
David Howells31143d52007-05-09 02:33:46 -0700502 if (test_set_page_writeback(primary_page))
503 BUG();
504
David Howells4343d002017-11-02 15:27:52 +0000505 /* Find all consecutive lockable dirty pages that have contiguous
506 * written regions, stopping when we find a page that is not
507 * immediately lockable, is not dirty or is missing, or we reach the
508 * end of the range.
509 */
David Howells31143d52007-05-09 02:33:46 -0700510 start = primary_page->index;
David Howells4343d002017-11-02 15:27:52 +0000511 priv = page_private(primary_page);
512 offset = priv & AFS_PRIV_MAX;
513 to = priv >> AFS_PRIV_SHIFT;
David Howells13524ab2017-11-02 15:27:53 +0000514 trace_afs_page_dirty(vnode, tracepoint_string("store"),
515 primary_page->index, priv);
David Howells4343d002017-11-02 15:27:52 +0000516
517 WARN_ON(offset == to);
David Howells13524ab2017-11-02 15:27:53 +0000518 if (offset == to)
519 trace_afs_page_dirty(vnode, tracepoint_string("WARN"),
520 primary_page->index, priv);
David Howells4343d002017-11-02 15:27:52 +0000521
David Howells5a813272018-04-06 14:17:26 +0100522 if (start >= final_page ||
523 (to < PAGE_SIZE && !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)))
David Howells31143d52007-05-09 02:33:46 -0700524 goto no_more;
David Howells4343d002017-11-02 15:27:52 +0000525
David Howells31143d52007-05-09 02:33:46 -0700526 start++;
527 do {
528 _debug("more %lx [%lx]", start, count);
David Howells4343d002017-11-02 15:27:52 +0000529 n = final_page - start + 1;
David Howells31143d52007-05-09 02:33:46 -0700530 if (n > ARRAY_SIZE(pages))
531 n = ARRAY_SIZE(pages);
David Howells4343d002017-11-02 15:27:52 +0000532 n = find_get_pages_contig(mapping, start, ARRAY_SIZE(pages), pages);
David Howells31143d52007-05-09 02:33:46 -0700533 _debug("fgpc %u", n);
534 if (n == 0)
535 goto no_more;
536 if (pages[0]->index != start) {
David Howells9d577b62007-05-10 22:22:19 -0700537 do {
538 put_page(pages[--n]);
539 } while (n > 0);
David Howells31143d52007-05-09 02:33:46 -0700540 goto no_more;
541 }
542
543 for (loop = 0; loop < n; loop++) {
544 page = pages[loop];
David Howells5a813272018-04-06 14:17:26 +0100545 if (to != PAGE_SIZE &&
546 !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags))
547 break;
David Howells4343d002017-11-02 15:27:52 +0000548 if (page->index > final_page)
David Howells31143d52007-05-09 02:33:46 -0700549 break;
Nick Piggin529ae9a2008-08-02 12:01:03 +0200550 if (!trylock_page(page))
David Howells31143d52007-05-09 02:33:46 -0700551 break;
David Howells4343d002017-11-02 15:27:52 +0000552 if (!PageDirty(page) || PageWriteback(page)) {
David Howells31143d52007-05-09 02:33:46 -0700553 unlock_page(page);
554 break;
555 }
David Howells4343d002017-11-02 15:27:52 +0000556
557 priv = page_private(page);
558 f = priv & AFS_PRIV_MAX;
559 t = priv >> AFS_PRIV_SHIFT;
David Howells5a813272018-04-06 14:17:26 +0100560 if (f != 0 &&
561 !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)) {
David Howells4343d002017-11-02 15:27:52 +0000562 unlock_page(page);
563 break;
564 }
565 to = t;
566
David Howells13524ab2017-11-02 15:27:53 +0000567 trace_afs_page_dirty(vnode, tracepoint_string("store+"),
568 page->index, priv);
569
David Howells31143d52007-05-09 02:33:46 -0700570 if (!clear_page_dirty_for_io(page))
571 BUG();
572 if (test_set_page_writeback(page))
573 BUG();
574 unlock_page(page);
575 put_page(page);
576 }
577 count += loop;
578 if (loop < n) {
579 for (; loop < n; loop++)
580 put_page(pages[loop]);
581 goto no_more;
582 }
583
584 start += loop;
David Howells4343d002017-11-02 15:27:52 +0000585 } while (start <= final_page && count < 65536);
David Howells31143d52007-05-09 02:33:46 -0700586
587no_more:
David Howells4343d002017-11-02 15:27:52 +0000588 /* We now have a contiguous set of dirty pages, each with writeback
589 * set; the first page is still locked at this point, but all the rest
590 * have been unlocked.
591 */
592 unlock_page(primary_page);
593
David Howells31143d52007-05-09 02:33:46 -0700594 first = primary_page->index;
595 last = first + count - 1;
596
David Howells793fe822020-06-12 16:13:52 +0100597 end = (loff_t)last * PAGE_SIZE + to;
598 i_size = i_size_read(&vnode->vfs_inode);
599
David Howells31143d52007-05-09 02:33:46 -0700600 _debug("write back %lx[%u..] to %lx[..%u]", first, offset, last, to);
David Howells793fe822020-06-12 16:13:52 +0100601 if (end > i_size)
602 to = i_size & ~PAGE_MASK;
David Howells31143d52007-05-09 02:33:46 -0700603
David Howells4343d002017-11-02 15:27:52 +0000604 ret = afs_store_data(mapping, first, last, offset, to);
605 switch (ret) {
606 case 0:
David Howells31143d52007-05-09 02:33:46 -0700607 ret = count;
David Howells4343d002017-11-02 15:27:52 +0000608 break;
609
610 default:
611 pr_notice("kAFS: Unexpected error from FS.StoreData %d\n", ret);
Gustavo A. R. Silvadf561f662020-08-23 17:36:59 -0500612 fallthrough;
David Howells4343d002017-11-02 15:27:52 +0000613 case -EACCES:
614 case -EPERM:
615 case -ENOKEY:
616 case -EKEYEXPIRED:
617 case -EKEYREJECTED:
618 case -EKEYREVOKED:
619 afs_redirty_pages(wbc, mapping, first, last);
620 mapping_set_error(mapping, ret);
621 break;
622
623 case -EDQUOT:
624 case -ENOSPC:
625 afs_redirty_pages(wbc, mapping, first, last);
626 mapping_set_error(mapping, -ENOSPC);
627 break;
628
629 case -EROFS:
630 case -EIO:
631 case -EREMOTEIO:
632 case -EFBIG:
633 case -ENOENT:
634 case -ENOMEDIUM:
635 case -ENXIO:
David Howellsf51375c2018-10-20 00:57:57 +0100636 trace_afs_file_error(vnode, ret, afs_file_error_writeback_fail);
David Howells4343d002017-11-02 15:27:52 +0000637 afs_kill_pages(mapping, first, last);
638 mapping_set_error(mapping, ret);
639 break;
David Howells31143d52007-05-09 02:33:46 -0700640 }
641
642 _leave(" = %d", ret);
643 return ret;
644}
645
646/*
647 * write a page back to the server
648 * - the caller locked the page for us
649 */
650int afs_writepage(struct page *page, struct writeback_control *wbc)
651{
David Howells31143d52007-05-09 02:33:46 -0700652 int ret;
653
654 _enter("{%lx},", page->index);
655
David Howells4343d002017-11-02 15:27:52 +0000656 ret = afs_write_back_from_locked_page(page->mapping, wbc, page,
657 wbc->range_end >> PAGE_SHIFT);
David Howells31143d52007-05-09 02:33:46 -0700658 if (ret < 0) {
659 _leave(" = %d", ret);
660 return 0;
661 }
662
663 wbc->nr_to_write -= ret;
David Howells31143d52007-05-09 02:33:46 -0700664
665 _leave(" = 0");
666 return 0;
667}
668
669/*
670 * write a region of pages back to the server
671 */
Adrian Bunkc1206a22007-10-16 23:26:41 -0700672static int afs_writepages_region(struct address_space *mapping,
673 struct writeback_control *wbc,
674 pgoff_t index, pgoff_t end, pgoff_t *_next)
David Howells31143d52007-05-09 02:33:46 -0700675{
David Howells31143d52007-05-09 02:33:46 -0700676 struct page *page;
677 int ret, n;
678
679 _enter(",,%lx,%lx,", index, end);
680
681 do {
Jan Karaaef6e412017-11-15 17:35:23 -0800682 n = find_get_pages_range_tag(mapping, &index, end,
683 PAGECACHE_TAG_DIRTY, 1, &page);
David Howells31143d52007-05-09 02:33:46 -0700684 if (!n)
685 break;
686
687 _debug("wback %lx", page->index);
688
Matthew Wilcoxb93b0162018-04-10 16:36:56 -0700689 /*
690 * at this point we hold neither the i_pages lock nor the
691 * page lock: the page may be truncated or invalidated
692 * (changing page->mapping to NULL), or even swizzled
693 * back from swapper_space to tmpfs file mapping
David Howells31143d52007-05-09 02:33:46 -0700694 */
David Howells4343d002017-11-02 15:27:52 +0000695 ret = lock_page_killable(page);
696 if (ret < 0) {
697 put_page(page);
698 _leave(" = %d", ret);
699 return ret;
700 }
David Howells31143d52007-05-09 02:33:46 -0700701
David Howellsc5051c72017-03-16 16:27:49 +0000702 if (page->mapping != mapping || !PageDirty(page)) {
David Howells31143d52007-05-09 02:33:46 -0700703 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300704 put_page(page);
David Howells31143d52007-05-09 02:33:46 -0700705 continue;
706 }
707
David Howellsc5051c72017-03-16 16:27:49 +0000708 if (PageWriteback(page)) {
David Howells31143d52007-05-09 02:33:46 -0700709 unlock_page(page);
David Howellsc5051c72017-03-16 16:27:49 +0000710 if (wbc->sync_mode != WB_SYNC_NONE)
711 wait_on_page_writeback(page);
David Howells29c8bbb2017-03-16 16:27:43 +0000712 put_page(page);
David Howells31143d52007-05-09 02:33:46 -0700713 continue;
714 }
715
David Howells65a15102017-03-16 16:27:49 +0000716 if (!clear_page_dirty_for_io(page))
717 BUG();
David Howells4343d002017-11-02 15:27:52 +0000718 ret = afs_write_back_from_locked_page(mapping, wbc, page, end);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300719 put_page(page);
David Howells31143d52007-05-09 02:33:46 -0700720 if (ret < 0) {
721 _leave(" = %d", ret);
722 return ret;
723 }
724
725 wbc->nr_to_write -= ret;
726
David Howells31143d52007-05-09 02:33:46 -0700727 cond_resched();
728 } while (index < end && wbc->nr_to_write > 0);
729
730 *_next = index;
731 _leave(" = 0 [%lx]", *_next);
732 return 0;
733}
734
735/*
736 * write some of the pending data back to the server
737 */
738int afs_writepages(struct address_space *mapping,
739 struct writeback_control *wbc)
740{
David Howells31143d52007-05-09 02:33:46 -0700741 pgoff_t start, end, next;
742 int ret;
743
744 _enter("");
745
David Howells31143d52007-05-09 02:33:46 -0700746 if (wbc->range_cyclic) {
747 start = mapping->writeback_index;
748 end = -1;
749 ret = afs_writepages_region(mapping, wbc, start, end, &next);
Wu Fengguang1b430be2010-10-26 14:21:26 -0700750 if (start > 0 && wbc->nr_to_write > 0 && ret == 0)
David Howells31143d52007-05-09 02:33:46 -0700751 ret = afs_writepages_region(mapping, wbc, 0, start,
752 &next);
753 mapping->writeback_index = next;
754 } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300755 end = (pgoff_t)(LLONG_MAX >> PAGE_SHIFT);
David Howells31143d52007-05-09 02:33:46 -0700756 ret = afs_writepages_region(mapping, wbc, 0, end, &next);
757 if (wbc->nr_to_write > 0)
758 mapping->writeback_index = next;
759 } else {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300760 start = wbc->range_start >> PAGE_SHIFT;
761 end = wbc->range_end >> PAGE_SHIFT;
David Howells31143d52007-05-09 02:33:46 -0700762 ret = afs_writepages_region(mapping, wbc, start, end, &next);
763 }
764
765 _leave(" = %d", ret);
766 return ret;
767}
768
769/*
David Howells31143d52007-05-09 02:33:46 -0700770 * write to an AFS file
771 */
Al Viro50b55512014-04-03 14:13:46 -0400772ssize_t afs_file_write(struct kiocb *iocb, struct iov_iter *from)
David Howells31143d52007-05-09 02:33:46 -0700773{
Al Viro496ad9a2013-01-23 17:07:38 -0500774 struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp));
David Howells31143d52007-05-09 02:33:46 -0700775 ssize_t result;
Al Viro50b55512014-04-03 14:13:46 -0400776 size_t count = iov_iter_count(from);
David Howells31143d52007-05-09 02:33:46 -0700777
David Howells3b6492d2018-10-20 00:57:57 +0100778 _enter("{%llx:%llu},{%zu},",
Al Viro50b55512014-04-03 14:13:46 -0400779 vnode->fid.vid, vnode->fid.vnode, count);
David Howells31143d52007-05-09 02:33:46 -0700780
781 if (IS_SWAPFILE(&vnode->vfs_inode)) {
782 printk(KERN_INFO
783 "AFS: Attempt to write to active swap file!\n");
784 return -EBUSY;
785 }
786
787 if (!count)
788 return 0;
789
Al Viro50b55512014-04-03 14:13:46 -0400790 result = generic_file_write_iter(iocb, from);
David Howells31143d52007-05-09 02:33:46 -0700791
David Howells31143d52007-05-09 02:33:46 -0700792 _leave(" = %zd", result);
793 return result;
794}
795
796/*
David Howells31143d52007-05-09 02:33:46 -0700797 * flush any dirty pages for this process, and check for write errors.
798 * - the return status from this call provides a reliable indication of
799 * whether any write errors occurred for this process.
800 */
Josef Bacik02c24a82011-07-16 20:44:56 -0400801int afs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
David Howells31143d52007-05-09 02:33:46 -0700802{
Al Viro3c981bf2013-09-03 13:37:45 -0400803 struct inode *inode = file_inode(file);
Al Viro3c981bf2013-09-03 13:37:45 -0400804 struct afs_vnode *vnode = AFS_FS_I(inode);
David Howells31143d52007-05-09 02:33:46 -0700805
David Howells3b6492d2018-10-20 00:57:57 +0100806 _enter("{%llx:%llu},{n=%pD},%d",
Al Viro3c981bf2013-09-03 13:37:45 -0400807 vnode->fid.vid, vnode->fid.vnode, file,
David Howells31143d52007-05-09 02:33:46 -0700808 datasync);
809
David Howells4343d002017-11-02 15:27:52 +0000810 return file_write_and_wait_range(file, start, end);
David Howells31143d52007-05-09 02:33:46 -0700811}
David Howells9b3f26c2009-04-03 16:42:41 +0100812
813/*
814 * notification that a previously read-only page is about to become writable
815 * - if it returns an error, the caller will deliver a bus error signal
816 */
Souptick Joarder0722f182018-08-23 17:00:48 -0700817vm_fault_t afs_page_mkwrite(struct vm_fault *vmf)
David Howells9b3f26c2009-04-03 16:42:41 +0100818{
David Howells1cf7a152017-11-02 15:27:52 +0000819 struct file *file = vmf->vma->vm_file;
820 struct inode *inode = file_inode(file);
821 struct afs_vnode *vnode = AFS_FS_I(inode);
822 unsigned long priv;
David Howells9b3f26c2009-04-03 16:42:41 +0100823
David Howells3b6492d2018-10-20 00:57:57 +0100824 _enter("{{%llx:%llu}},{%lx}",
David Howells1cf7a152017-11-02 15:27:52 +0000825 vnode->fid.vid, vnode->fid.vnode, vmf->page->index);
David Howells9b3f26c2009-04-03 16:42:41 +0100826
David Howells1cf7a152017-11-02 15:27:52 +0000827 sb_start_pagefault(inode->i_sb);
828
829 /* Wait for the page to be written to the cache before we allow it to
830 * be modified. We then assume the entire page will need writing back.
831 */
David Howells9b3f26c2009-04-03 16:42:41 +0100832#ifdef CONFIG_AFS_FSCACHE
David Howells1cf7a152017-11-02 15:27:52 +0000833 fscache_wait_on_page_write(vnode->cache, vmf->page);
David Howells9b3f26c2009-04-03 16:42:41 +0100834#endif
835
David Howells1cf7a152017-11-02 15:27:52 +0000836 if (PageWriteback(vmf->page) &&
837 wait_on_page_bit_killable(vmf->page, PG_writeback) < 0)
838 return VM_FAULT_RETRY;
839
840 if (lock_page_killable(vmf->page) < 0)
841 return VM_FAULT_RETRY;
842
843 /* We mustn't change page->private until writeback is complete as that
844 * details the portion of the page we need to write back and we might
845 * need to redirty the page if there's a problem.
846 */
847 wait_on_page_writeback(vmf->page);
848
849 priv = (unsigned long)PAGE_SIZE << AFS_PRIV_SHIFT; /* To */
850 priv |= 0; /* From */
David Howells13524ab2017-11-02 15:27:53 +0000851 trace_afs_page_dirty(vnode, tracepoint_string("mkwrite"),
852 vmf->page->index, priv);
David Howells1cf7a152017-11-02 15:27:52 +0000853 SetPagePrivate(vmf->page);
854 set_page_private(vmf->page, priv);
David Howellsbb413482020-06-12 00:15:13 +0100855 file_update_time(file);
David Howells1cf7a152017-11-02 15:27:52 +0000856
857 sb_end_pagefault(inode->i_sb);
858 return VM_FAULT_LOCKED;
David Howells9b3f26c2009-04-03 16:42:41 +0100859}
David Howells4343d002017-11-02 15:27:52 +0000860
861/*
862 * Prune the keys cached for writeback. The caller must hold vnode->wb_lock.
863 */
864void afs_prune_wb_keys(struct afs_vnode *vnode)
865{
866 LIST_HEAD(graveyard);
867 struct afs_wb_key *wbk, *tmp;
868
869 /* Discard unused keys */
870 spin_lock(&vnode->wb_lock);
871
872 if (!mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_WRITEBACK) &&
873 !mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_DIRTY)) {
874 list_for_each_entry_safe(wbk, tmp, &vnode->wb_keys, vnode_link) {
875 if (refcount_read(&wbk->usage) == 1)
876 list_move(&wbk->vnode_link, &graveyard);
877 }
878 }
879
880 spin_unlock(&vnode->wb_lock);
881
882 while (!list_empty(&graveyard)) {
883 wbk = list_entry(graveyard.next, struct afs_wb_key, vnode_link);
884 list_del(&wbk->vnode_link);
885 afs_put_wb_key(wbk);
886 }
887}
888
889/*
890 * Clean up a page during invalidation.
891 */
892int afs_launder_page(struct page *page)
893{
894 struct address_space *mapping = page->mapping;
895 struct afs_vnode *vnode = AFS_FS_I(mapping->host);
896 unsigned long priv;
897 unsigned int f, t;
898 int ret = 0;
899
900 _enter("{%lx}", page->index);
901
902 priv = page_private(page);
903 if (clear_page_dirty_for_io(page)) {
904 f = 0;
905 t = PAGE_SIZE;
906 if (PagePrivate(page)) {
907 f = priv & AFS_PRIV_MAX;
908 t = priv >> AFS_PRIV_SHIFT;
909 }
910
David Howells13524ab2017-11-02 15:27:53 +0000911 trace_afs_page_dirty(vnode, tracepoint_string("launder"),
912 page->index, priv);
David Howells4343d002017-11-02 15:27:52 +0000913 ret = afs_store_data(mapping, page->index, page->index, t, f);
914 }
915
David Howells13524ab2017-11-02 15:27:53 +0000916 trace_afs_page_dirty(vnode, tracepoint_string("laundered"),
917 page->index, priv);
David Howells4343d002017-11-02 15:27:52 +0000918 set_page_private(page, 0);
919 ClearPagePrivate(page);
920
921#ifdef CONFIG_AFS_FSCACHE
922 if (PageFsCache(page)) {
923 fscache_wait_on_page_write(vnode->cache, page);
924 fscache_uncache_page(vnode->cache, page);
925 }
926#endif
927 return ret;
David Howells31143d52007-05-09 02:33:46 -0700928}