blob: 72efcfcf9f95efd2b5cae1257a8d01247367ebeb [file] [log] [blame]
David Howells31143d52007-05-09 02:33:46 -07001/* handling of writes to regular files and writing back to the server
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells ([email protected])
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 */
David Howells4343d002017-11-02 15:27:52 +000011
Alexey Dobriyan4af3c9c2007-10-16 23:29:23 -070012#include <linux/backing-dev.h>
David Howells31143d52007-05-09 02:33:46 -070013#include <linux/slab.h>
14#include <linux/fs.h>
15#include <linux/pagemap.h>
16#include <linux/writeback.h>
17#include <linux/pagevec.h>
18#include "internal.h"
19
David Howells31143d52007-05-09 02:33:46 -070020/*
21 * mark a page as having been made dirty and thus needing writeback
22 */
23int afs_set_page_dirty(struct page *page)
24{
25 _enter("");
26 return __set_page_dirty_nobuffers(page);
27}
28
29/*
David Howells31143d52007-05-09 02:33:46 -070030 * partly or wholly fill a page that's under preparation for writing
31 */
32static int afs_fill_page(struct afs_vnode *vnode, struct key *key,
David Howellse8e581a2017-03-16 16:27:44 +000033 loff_t pos, unsigned int len, struct page *page)
David Howells31143d52007-05-09 02:33:46 -070034{
David Howells196ee9c2017-01-05 10:38:34 +000035 struct afs_read *req;
David Howells2a0b4f62018-10-20 00:57:57 +010036 size_t p;
37 void *data;
David Howells31143d52007-05-09 02:33:46 -070038 int ret;
39
Anton Blanchard5e7f2332011-06-13 22:31:12 +010040 _enter(",,%llu", (unsigned long long)pos);
David Howells31143d52007-05-09 02:33:46 -070041
David Howells2a0b4f62018-10-20 00:57:57 +010042 if (pos >= vnode->vfs_inode.i_size) {
43 p = pos & ~PAGE_MASK;
44 ASSERTCMP(p + len, <=, PAGE_SIZE);
45 data = kmap(page);
46 memset(data + p, 0, len);
47 kunmap(page);
48 return 0;
49 }
50
David Howells196ee9c2017-01-05 10:38:34 +000051 req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
52 GFP_KERNEL);
53 if (!req)
54 return -ENOMEM;
55
David Howellsf3ddee82018-04-06 14:17:25 +010056 refcount_set(&req->usage, 1);
David Howells196ee9c2017-01-05 10:38:34 +000057 req->pos = pos;
David Howellse8e581a2017-03-16 16:27:44 +000058 req->len = len;
David Howells196ee9c2017-01-05 10:38:34 +000059 req->nr_pages = 1;
David Howellsf3ddee82018-04-06 14:17:25 +010060 req->pages = req->array;
David Howells196ee9c2017-01-05 10:38:34 +000061 req->pages[0] = page;
David Howells5611ef22017-03-16 16:27:43 +000062 get_page(page);
David Howells196ee9c2017-01-05 10:38:34 +000063
David Howellsd2ddc772017-11-02 15:27:50 +000064 ret = afs_fetch_data(vnode, key, req);
David Howells196ee9c2017-01-05 10:38:34 +000065 afs_put_read(req);
David Howells31143d52007-05-09 02:33:46 -070066 if (ret < 0) {
67 if (ret == -ENOENT) {
68 _debug("got NOENT from server"
69 " - marking file deleted and stale");
70 set_bit(AFS_VNODE_DELETED, &vnode->flags);
71 ret = -ESTALE;
72 }
73 }
74
75 _leave(" = %d", ret);
76 return ret;
77}
78
79/*
David Howells31143d52007-05-09 02:33:46 -070080 * prepare to perform part of a write to a page
David Howells31143d52007-05-09 02:33:46 -070081 */
Nick Piggin15b46502008-10-15 22:04:32 -070082int afs_write_begin(struct file *file, struct address_space *mapping,
83 loff_t pos, unsigned len, unsigned flags,
84 struct page **pagep, void **fsdata)
David Howells31143d52007-05-09 02:33:46 -070085{
Al Viro496ad9a2013-01-23 17:07:38 -050086 struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
Nick Piggin15b46502008-10-15 22:04:32 -070087 struct page *page;
David Howells215804a2017-11-02 15:27:52 +000088 struct key *key = afs_file_key(file);
David Howells4343d002017-11-02 15:27:52 +000089 unsigned long priv;
90 unsigned f, from = pos & (PAGE_SIZE - 1);
91 unsigned t, to = from + len;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +030092 pgoff_t index = pos >> PAGE_SHIFT;
David Howells31143d52007-05-09 02:33:46 -070093 int ret;
94
David Howells3b6492d2018-10-20 00:57:57 +010095 _enter("{%llx:%llu},{%lx},%u,%u",
Nick Piggin15b46502008-10-15 22:04:32 -070096 vnode->fid.vid, vnode->fid.vnode, index, from, to);
David Howells31143d52007-05-09 02:33:46 -070097
David Howells4343d002017-11-02 15:27:52 +000098 /* We want to store information about how much of a page is altered in
99 * page->private.
100 */
101 BUILD_BUG_ON(PAGE_SIZE > 32768 && sizeof(page->private) < 8);
David Howells31143d52007-05-09 02:33:46 -0700102
Nick Piggin54566b22009-01-04 12:00:53 -0800103 page = grab_cache_page_write_begin(mapping, index, flags);
David Howells4343d002017-11-02 15:27:52 +0000104 if (!page)
Nick Piggin15b46502008-10-15 22:04:32 -0700105 return -ENOMEM;
Nick Piggin15b46502008-10-15 22:04:32 -0700106
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300107 if (!PageUptodate(page) && len != PAGE_SIZE) {
David Howellse8e581a2017-03-16 16:27:44 +0000108 ret = afs_fill_page(vnode, key, pos & PAGE_MASK, PAGE_SIZE, page);
David Howells31143d52007-05-09 02:33:46 -0700109 if (ret < 0) {
David Howells6d06b0d2017-03-16 16:27:48 +0000110 unlock_page(page);
111 put_page(page);
David Howells31143d52007-05-09 02:33:46 -0700112 _leave(" = %d [prep]", ret);
113 return ret;
114 }
Nick Piggin15b46502008-10-15 22:04:32 -0700115 SetPageUptodate(page);
David Howells31143d52007-05-09 02:33:46 -0700116 }
117
David Howells6d06b0d2017-03-16 16:27:48 +0000118 /* page won't leak in error case: it eventually gets cleaned off LRU */
119 *pagep = page;
120
David Howells31143d52007-05-09 02:33:46 -0700121try_again:
David Howells4343d002017-11-02 15:27:52 +0000122 /* See if this page is already partially written in a way that we can
123 * merge the new write with.
124 */
125 t = f = 0;
126 if (PagePrivate(page)) {
127 priv = page_private(page);
128 f = priv & AFS_PRIV_MAX;
129 t = priv >> AFS_PRIV_SHIFT;
130 ASSERTCMP(f, <=, t);
David Howells31143d52007-05-09 02:33:46 -0700131 }
132
David Howells4343d002017-11-02 15:27:52 +0000133 if (f != t) {
David Howells5a039c32017-11-18 00:13:30 +0000134 if (PageWriteback(page)) {
135 trace_afs_page_dirty(vnode, tracepoint_string("alrdy"),
136 page->index, priv);
137 goto flush_conflicting_write;
138 }
David Howells5a813272018-04-06 14:17:26 +0100139 /* If the file is being filled locally, allow inter-write
140 * spaces to be merged into writes. If it's not, only write
141 * back what the user gives us.
142 */
143 if (!test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags) &&
144 (to < f || from > t))
David Howells4343d002017-11-02 15:27:52 +0000145 goto flush_conflicting_write;
146 if (from < f)
147 f = from;
148 if (to > t)
149 t = to;
150 } else {
151 f = from;
152 t = to;
David Howells31143d52007-05-09 02:33:46 -0700153 }
154
David Howells4343d002017-11-02 15:27:52 +0000155 priv = (unsigned long)t << AFS_PRIV_SHIFT;
156 priv |= f;
David Howells13524ab2017-11-02 15:27:53 +0000157 trace_afs_page_dirty(vnode, tracepoint_string("begin"),
158 page->index, priv);
David Howells31143d52007-05-09 02:33:46 -0700159 SetPagePrivate(page);
David Howells4343d002017-11-02 15:27:52 +0000160 set_page_private(page, priv);
161 _leave(" = 0");
David Howells31143d52007-05-09 02:33:46 -0700162 return 0;
163
David Howells4343d002017-11-02 15:27:52 +0000164 /* The previous write and this write aren't adjacent or overlapping, so
165 * flush the page out.
166 */
167flush_conflicting_write:
David Howells31143d52007-05-09 02:33:46 -0700168 _debug("flush conflict");
David Howells4343d002017-11-02 15:27:52 +0000169 ret = write_one_page(page);
170 if (ret < 0) {
171 _leave(" = %d", ret);
172 return ret;
David Howells31143d52007-05-09 02:33:46 -0700173 }
174
David Howells4343d002017-11-02 15:27:52 +0000175 ret = lock_page_killable(page);
176 if (ret < 0) {
177 _leave(" = %d", ret);
178 return ret;
179 }
David Howells31143d52007-05-09 02:33:46 -0700180 goto try_again;
181}
182
183/*
184 * finalise part of a write to a page
185 */
Nick Piggin15b46502008-10-15 22:04:32 -0700186int afs_write_end(struct file *file, struct address_space *mapping,
187 loff_t pos, unsigned len, unsigned copied,
188 struct page *page, void *fsdata)
David Howells31143d52007-05-09 02:33:46 -0700189{
Al Viro496ad9a2013-01-23 17:07:38 -0500190 struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
David Howells215804a2017-11-02 15:27:52 +0000191 struct key *key = afs_file_key(file);
David Howells31143d52007-05-09 02:33:46 -0700192 loff_t i_size, maybe_i_size;
David Howellse8e581a2017-03-16 16:27:44 +0000193 int ret;
David Howells31143d52007-05-09 02:33:46 -0700194
David Howells3b6492d2018-10-20 00:57:57 +0100195 _enter("{%llx:%llu},{%lx}",
Nick Piggin15b46502008-10-15 22:04:32 -0700196 vnode->fid.vid, vnode->fid.vnode, page->index);
David Howells31143d52007-05-09 02:33:46 -0700197
Nick Piggin15b46502008-10-15 22:04:32 -0700198 maybe_i_size = pos + copied;
David Howells31143d52007-05-09 02:33:46 -0700199
200 i_size = i_size_read(&vnode->vfs_inode);
201 if (maybe_i_size > i_size) {
David Howells4343d002017-11-02 15:27:52 +0000202 spin_lock(&vnode->wb_lock);
David Howells31143d52007-05-09 02:33:46 -0700203 i_size = i_size_read(&vnode->vfs_inode);
204 if (maybe_i_size > i_size)
205 i_size_write(&vnode->vfs_inode, maybe_i_size);
David Howells4343d002017-11-02 15:27:52 +0000206 spin_unlock(&vnode->wb_lock);
David Howells31143d52007-05-09 02:33:46 -0700207 }
208
David Howellse8e581a2017-03-16 16:27:44 +0000209 if (!PageUptodate(page)) {
210 if (copied < len) {
211 /* Try and load any missing data from the server. The
212 * unmarshalling routine will take care of clearing any
213 * bits that are beyond the EOF.
214 */
215 ret = afs_fill_page(vnode, key, pos + copied,
216 len - copied, page);
217 if (ret < 0)
David Howellsafae4572018-01-02 10:02:19 +0000218 goto out;
David Howellse8e581a2017-03-16 16:27:44 +0000219 }
220 SetPageUptodate(page);
221 }
222
David Howells31143d52007-05-09 02:33:46 -0700223 set_page_dirty(page);
David Howells31143d52007-05-09 02:33:46 -0700224 if (PageDirty(page))
225 _debug("dirtied");
David Howellsafae4572018-01-02 10:02:19 +0000226 ret = copied;
227
228out:
Nick Piggin15b46502008-10-15 22:04:32 -0700229 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300230 put_page(page);
David Howellsafae4572018-01-02 10:02:19 +0000231 return ret;
David Howells31143d52007-05-09 02:33:46 -0700232}
233
234/*
235 * kill all the pages in the given range
236 */
David Howells4343d002017-11-02 15:27:52 +0000237static void afs_kill_pages(struct address_space *mapping,
David Howells31143d52007-05-09 02:33:46 -0700238 pgoff_t first, pgoff_t last)
239{
David Howells4343d002017-11-02 15:27:52 +0000240 struct afs_vnode *vnode = AFS_FS_I(mapping->host);
David Howells31143d52007-05-09 02:33:46 -0700241 struct pagevec pv;
242 unsigned count, loop;
243
David Howells3b6492d2018-10-20 00:57:57 +0100244 _enter("{%llx:%llu},%lx-%lx",
David Howells31143d52007-05-09 02:33:46 -0700245 vnode->fid.vid, vnode->fid.vnode, first, last);
246
Mel Gorman86679822017-11-15 17:37:52 -0800247 pagevec_init(&pv);
David Howells31143d52007-05-09 02:33:46 -0700248
249 do {
250 _debug("kill %lx-%lx", first, last);
251
252 count = last - first + 1;
253 if (count > PAGEVEC_SIZE)
254 count = PAGEVEC_SIZE;
David Howells4343d002017-11-02 15:27:52 +0000255 pv.nr = find_get_pages_contig(mapping, first, count, pv.pages);
David Howells31143d52007-05-09 02:33:46 -0700256 ASSERTCMP(pv.nr, ==, count);
257
258 for (loop = 0; loop < count; loop++) {
David Howells7286a352017-03-16 16:27:48 +0000259 struct page *page = pv.pages[loop];
260 ClearPageUptodate(page);
David Howells4343d002017-11-02 15:27:52 +0000261 SetPageError(page);
262 end_page_writeback(page);
David Howells7286a352017-03-16 16:27:48 +0000263 if (page->index >= first)
264 first = page->index + 1;
David Howells4343d002017-11-02 15:27:52 +0000265 lock_page(page);
266 generic_error_remove_page(mapping, page);
David Howells31143d52007-05-09 02:33:46 -0700267 }
268
269 __pagevec_release(&pv);
David Howells4343d002017-11-02 15:27:52 +0000270 } while (first <= last);
David Howells31143d52007-05-09 02:33:46 -0700271
272 _leave("");
273}
274
275/*
David Howells4343d002017-11-02 15:27:52 +0000276 * Redirty all the pages in a given range.
David Howells31143d52007-05-09 02:33:46 -0700277 */
David Howells4343d002017-11-02 15:27:52 +0000278static void afs_redirty_pages(struct writeback_control *wbc,
279 struct address_space *mapping,
280 pgoff_t first, pgoff_t last)
David Howells31143d52007-05-09 02:33:46 -0700281{
David Howells4343d002017-11-02 15:27:52 +0000282 struct afs_vnode *vnode = AFS_FS_I(mapping->host);
283 struct pagevec pv;
284 unsigned count, loop;
285
David Howells3b6492d2018-10-20 00:57:57 +0100286 _enter("{%llx:%llu},%lx-%lx",
David Howells4343d002017-11-02 15:27:52 +0000287 vnode->fid.vid, vnode->fid.vnode, first, last);
288
Linus Torvalds487e2c92017-11-16 11:41:22 -0800289 pagevec_init(&pv);
David Howells4343d002017-11-02 15:27:52 +0000290
291 do {
292 _debug("redirty %lx-%lx", first, last);
293
294 count = last - first + 1;
295 if (count > PAGEVEC_SIZE)
296 count = PAGEVEC_SIZE;
297 pv.nr = find_get_pages_contig(mapping, first, count, pv.pages);
298 ASSERTCMP(pv.nr, ==, count);
299
300 for (loop = 0; loop < count; loop++) {
301 struct page *page = pv.pages[loop];
302
303 redirty_page_for_writepage(wbc, page);
304 end_page_writeback(page);
David Howells31143d52007-05-09 02:33:46 -0700305 if (page->index >= first)
306 first = page->index + 1;
307 }
308
309 __pagevec_release(&pv);
David Howells4343d002017-11-02 15:27:52 +0000310 } while (first <= last);
David Howells31143d52007-05-09 02:33:46 -0700311
312 _leave("");
313}
314
315/*
David Howellsd2ddc772017-11-02 15:27:50 +0000316 * write to a file
317 */
David Howells4343d002017-11-02 15:27:52 +0000318static int afs_store_data(struct address_space *mapping,
319 pgoff_t first, pgoff_t last,
David Howellsd2ddc772017-11-02 15:27:50 +0000320 unsigned offset, unsigned to)
321{
David Howells4343d002017-11-02 15:27:52 +0000322 struct afs_vnode *vnode = AFS_FS_I(mapping->host);
David Howellsd2ddc772017-11-02 15:27:50 +0000323 struct afs_fs_cursor fc;
David Howells4343d002017-11-02 15:27:52 +0000324 struct afs_wb_key *wbk = NULL;
325 struct list_head *p;
326 int ret = -ENOKEY, ret2;
David Howellsd2ddc772017-11-02 15:27:50 +0000327
David Howells3b6492d2018-10-20 00:57:57 +0100328 _enter("%s{%llx:%llu.%u},%lx,%lx,%x,%x",
David Howellsd2ddc772017-11-02 15:27:50 +0000329 vnode->volume->name,
330 vnode->fid.vid,
331 vnode->fid.vnode,
332 vnode->fid.unique,
David Howellsd2ddc772017-11-02 15:27:50 +0000333 first, last, offset, to);
334
David Howells4343d002017-11-02 15:27:52 +0000335 spin_lock(&vnode->wb_lock);
336 p = vnode->wb_keys.next;
337
338 /* Iterate through the list looking for a valid key to use. */
339try_next_key:
340 while (p != &vnode->wb_keys) {
341 wbk = list_entry(p, struct afs_wb_key, vnode_link);
342 _debug("wbk %u", key_serial(wbk->key));
343 ret2 = key_validate(wbk->key);
344 if (ret2 == 0)
345 goto found_key;
346 if (ret == -ENOKEY)
347 ret = ret2;
348 p = p->next;
349 }
350
351 spin_unlock(&vnode->wb_lock);
352 afs_put_wb_key(wbk);
353 _leave(" = %d [no keys]", ret);
354 return ret;
355
356found_key:
357 refcount_inc(&wbk->usage);
358 spin_unlock(&vnode->wb_lock);
359
360 _debug("USE WB KEY %u", key_serial(wbk->key));
361
David Howellsd2ddc772017-11-02 15:27:50 +0000362 ret = -ERESTARTSYS;
David Howells4343d002017-11-02 15:27:52 +0000363 if (afs_begin_vnode_operation(&fc, vnode, wbk->key)) {
David Howellsd2ddc772017-11-02 15:27:50 +0000364 while (afs_select_fileserver(&fc)) {
David Howells68251f02018-05-12 22:31:33 +0100365 fc.cb_break = afs_calc_vnode_cb_break(vnode);
David Howells4343d002017-11-02 15:27:52 +0000366 afs_fs_store_data(&fc, mapping, first, last, offset, to);
David Howellsd2ddc772017-11-02 15:27:50 +0000367 }
368
369 afs_check_for_remote_deletion(&fc, fc.vnode);
370 afs_vnode_commit_status(&fc, vnode, fc.cb_break);
371 ret = afs_end_vnode_operation(&fc);
372 }
373
David Howells4343d002017-11-02 15:27:52 +0000374 switch (ret) {
David Howells76a5cb62018-04-06 14:17:26 +0100375 case 0:
376 afs_stat_v(vnode, n_stores);
377 atomic_long_add((last * PAGE_SIZE + to) -
378 (first * PAGE_SIZE + offset),
379 &afs_v2net(vnode)->n_store_bytes);
380 break;
David Howells4343d002017-11-02 15:27:52 +0000381 case -EACCES:
382 case -EPERM:
383 case -ENOKEY:
384 case -EKEYEXPIRED:
385 case -EKEYREJECTED:
386 case -EKEYREVOKED:
387 _debug("next");
388 spin_lock(&vnode->wb_lock);
389 p = wbk->vnode_link.next;
390 afs_put_wb_key(wbk);
391 goto try_next_key;
392 }
393
394 afs_put_wb_key(wbk);
David Howellsd2ddc772017-11-02 15:27:50 +0000395 _leave(" = %d", ret);
396 return ret;
397}
398
399/*
David Howells4343d002017-11-02 15:27:52 +0000400 * Synchronously write back the locked page and any subsequent non-locked dirty
401 * pages.
David Howells31143d52007-05-09 02:33:46 -0700402 */
David Howells4343d002017-11-02 15:27:52 +0000403static int afs_write_back_from_locked_page(struct address_space *mapping,
404 struct writeback_control *wbc,
405 struct page *primary_page,
406 pgoff_t final_page)
David Howells31143d52007-05-09 02:33:46 -0700407{
David Howells13524ab2017-11-02 15:27:53 +0000408 struct afs_vnode *vnode = AFS_FS_I(mapping->host);
David Howells31143d52007-05-09 02:33:46 -0700409 struct page *pages[8], *page;
David Howells4343d002017-11-02 15:27:52 +0000410 unsigned long count, priv;
411 unsigned n, offset, to, f, t;
David Howells31143d52007-05-09 02:33:46 -0700412 pgoff_t start, first, last;
413 int loop, ret;
414
415 _enter(",%lx", primary_page->index);
416
417 count = 1;
David Howells31143d52007-05-09 02:33:46 -0700418 if (test_set_page_writeback(primary_page))
419 BUG();
420
David Howells4343d002017-11-02 15:27:52 +0000421 /* Find all consecutive lockable dirty pages that have contiguous
422 * written regions, stopping when we find a page that is not
423 * immediately lockable, is not dirty or is missing, or we reach the
424 * end of the range.
425 */
David Howells31143d52007-05-09 02:33:46 -0700426 start = primary_page->index;
David Howells4343d002017-11-02 15:27:52 +0000427 priv = page_private(primary_page);
428 offset = priv & AFS_PRIV_MAX;
429 to = priv >> AFS_PRIV_SHIFT;
David Howells13524ab2017-11-02 15:27:53 +0000430 trace_afs_page_dirty(vnode, tracepoint_string("store"),
431 primary_page->index, priv);
David Howells4343d002017-11-02 15:27:52 +0000432
433 WARN_ON(offset == to);
David Howells13524ab2017-11-02 15:27:53 +0000434 if (offset == to)
435 trace_afs_page_dirty(vnode, tracepoint_string("WARN"),
436 primary_page->index, priv);
David Howells4343d002017-11-02 15:27:52 +0000437
David Howells5a813272018-04-06 14:17:26 +0100438 if (start >= final_page ||
439 (to < PAGE_SIZE && !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)))
David Howells31143d52007-05-09 02:33:46 -0700440 goto no_more;
David Howells4343d002017-11-02 15:27:52 +0000441
David Howells31143d52007-05-09 02:33:46 -0700442 start++;
443 do {
444 _debug("more %lx [%lx]", start, count);
David Howells4343d002017-11-02 15:27:52 +0000445 n = final_page - start + 1;
David Howells31143d52007-05-09 02:33:46 -0700446 if (n > ARRAY_SIZE(pages))
447 n = ARRAY_SIZE(pages);
David Howells4343d002017-11-02 15:27:52 +0000448 n = find_get_pages_contig(mapping, start, ARRAY_SIZE(pages), pages);
David Howells31143d52007-05-09 02:33:46 -0700449 _debug("fgpc %u", n);
450 if (n == 0)
451 goto no_more;
452 if (pages[0]->index != start) {
David Howells9d577b62007-05-10 22:22:19 -0700453 do {
454 put_page(pages[--n]);
455 } while (n > 0);
David Howells31143d52007-05-09 02:33:46 -0700456 goto no_more;
457 }
458
459 for (loop = 0; loop < n; loop++) {
460 page = pages[loop];
David Howells5a813272018-04-06 14:17:26 +0100461 if (to != PAGE_SIZE &&
462 !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags))
463 break;
David Howells4343d002017-11-02 15:27:52 +0000464 if (page->index > final_page)
David Howells31143d52007-05-09 02:33:46 -0700465 break;
Nick Piggin529ae9a2008-08-02 12:01:03 +0200466 if (!trylock_page(page))
David Howells31143d52007-05-09 02:33:46 -0700467 break;
David Howells4343d002017-11-02 15:27:52 +0000468 if (!PageDirty(page) || PageWriteback(page)) {
David Howells31143d52007-05-09 02:33:46 -0700469 unlock_page(page);
470 break;
471 }
David Howells4343d002017-11-02 15:27:52 +0000472
473 priv = page_private(page);
474 f = priv & AFS_PRIV_MAX;
475 t = priv >> AFS_PRIV_SHIFT;
David Howells5a813272018-04-06 14:17:26 +0100476 if (f != 0 &&
477 !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)) {
David Howells4343d002017-11-02 15:27:52 +0000478 unlock_page(page);
479 break;
480 }
481 to = t;
482
David Howells13524ab2017-11-02 15:27:53 +0000483 trace_afs_page_dirty(vnode, tracepoint_string("store+"),
484 page->index, priv);
485
David Howells31143d52007-05-09 02:33:46 -0700486 if (!clear_page_dirty_for_io(page))
487 BUG();
488 if (test_set_page_writeback(page))
489 BUG();
490 unlock_page(page);
491 put_page(page);
492 }
493 count += loop;
494 if (loop < n) {
495 for (; loop < n; loop++)
496 put_page(pages[loop]);
497 goto no_more;
498 }
499
500 start += loop;
David Howells4343d002017-11-02 15:27:52 +0000501 } while (start <= final_page && count < 65536);
David Howells31143d52007-05-09 02:33:46 -0700502
503no_more:
David Howells4343d002017-11-02 15:27:52 +0000504 /* We now have a contiguous set of dirty pages, each with writeback
505 * set; the first page is still locked at this point, but all the rest
506 * have been unlocked.
507 */
508 unlock_page(primary_page);
509
David Howells31143d52007-05-09 02:33:46 -0700510 first = primary_page->index;
511 last = first + count - 1;
512
David Howells31143d52007-05-09 02:33:46 -0700513 _debug("write back %lx[%u..] to %lx[..%u]", first, offset, last, to);
514
David Howells4343d002017-11-02 15:27:52 +0000515 ret = afs_store_data(mapping, first, last, offset, to);
516 switch (ret) {
517 case 0:
David Howells31143d52007-05-09 02:33:46 -0700518 ret = count;
David Howells4343d002017-11-02 15:27:52 +0000519 break;
520
521 default:
522 pr_notice("kAFS: Unexpected error from FS.StoreData %d\n", ret);
523 /* Fall through */
524 case -EACCES:
525 case -EPERM:
526 case -ENOKEY:
527 case -EKEYEXPIRED:
528 case -EKEYREJECTED:
529 case -EKEYREVOKED:
530 afs_redirty_pages(wbc, mapping, first, last);
531 mapping_set_error(mapping, ret);
532 break;
533
534 case -EDQUOT:
535 case -ENOSPC:
536 afs_redirty_pages(wbc, mapping, first, last);
537 mapping_set_error(mapping, -ENOSPC);
538 break;
539
540 case -EROFS:
541 case -EIO:
542 case -EREMOTEIO:
543 case -EFBIG:
544 case -ENOENT:
545 case -ENOMEDIUM:
546 case -ENXIO:
David Howellsf51375c2018-10-20 00:57:57 +0100547 trace_afs_file_error(vnode, ret, afs_file_error_writeback_fail);
David Howells4343d002017-11-02 15:27:52 +0000548 afs_kill_pages(mapping, first, last);
549 mapping_set_error(mapping, ret);
550 break;
David Howells31143d52007-05-09 02:33:46 -0700551 }
552
553 _leave(" = %d", ret);
554 return ret;
555}
556
557/*
558 * write a page back to the server
559 * - the caller locked the page for us
560 */
561int afs_writepage(struct page *page, struct writeback_control *wbc)
562{
David Howells31143d52007-05-09 02:33:46 -0700563 int ret;
564
565 _enter("{%lx},", page->index);
566
David Howells4343d002017-11-02 15:27:52 +0000567 ret = afs_write_back_from_locked_page(page->mapping, wbc, page,
568 wbc->range_end >> PAGE_SHIFT);
David Howells31143d52007-05-09 02:33:46 -0700569 if (ret < 0) {
570 _leave(" = %d", ret);
571 return 0;
572 }
573
574 wbc->nr_to_write -= ret;
David Howells31143d52007-05-09 02:33:46 -0700575
576 _leave(" = 0");
577 return 0;
578}
579
580/*
581 * write a region of pages back to the server
582 */
Adrian Bunkc1206a22007-10-16 23:26:41 -0700583static int afs_writepages_region(struct address_space *mapping,
584 struct writeback_control *wbc,
585 pgoff_t index, pgoff_t end, pgoff_t *_next)
David Howells31143d52007-05-09 02:33:46 -0700586{
David Howells31143d52007-05-09 02:33:46 -0700587 struct page *page;
588 int ret, n;
589
590 _enter(",,%lx,%lx,", index, end);
591
592 do {
Jan Karaaef6e412017-11-15 17:35:23 -0800593 n = find_get_pages_range_tag(mapping, &index, end,
594 PAGECACHE_TAG_DIRTY, 1, &page);
David Howells31143d52007-05-09 02:33:46 -0700595 if (!n)
596 break;
597
598 _debug("wback %lx", page->index);
599
Matthew Wilcoxb93b0162018-04-10 16:36:56 -0700600 /*
601 * at this point we hold neither the i_pages lock nor the
602 * page lock: the page may be truncated or invalidated
603 * (changing page->mapping to NULL), or even swizzled
604 * back from swapper_space to tmpfs file mapping
David Howells31143d52007-05-09 02:33:46 -0700605 */
David Howells4343d002017-11-02 15:27:52 +0000606 ret = lock_page_killable(page);
607 if (ret < 0) {
608 put_page(page);
609 _leave(" = %d", ret);
610 return ret;
611 }
David Howells31143d52007-05-09 02:33:46 -0700612
David Howellsc5051c72017-03-16 16:27:49 +0000613 if (page->mapping != mapping || !PageDirty(page)) {
David Howells31143d52007-05-09 02:33:46 -0700614 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300615 put_page(page);
David Howells31143d52007-05-09 02:33:46 -0700616 continue;
617 }
618
David Howellsc5051c72017-03-16 16:27:49 +0000619 if (PageWriteback(page)) {
David Howells31143d52007-05-09 02:33:46 -0700620 unlock_page(page);
David Howellsc5051c72017-03-16 16:27:49 +0000621 if (wbc->sync_mode != WB_SYNC_NONE)
622 wait_on_page_writeback(page);
David Howells29c8bbb2017-03-16 16:27:43 +0000623 put_page(page);
David Howells31143d52007-05-09 02:33:46 -0700624 continue;
625 }
626
David Howells65a15102017-03-16 16:27:49 +0000627 if (!clear_page_dirty_for_io(page))
628 BUG();
David Howells4343d002017-11-02 15:27:52 +0000629 ret = afs_write_back_from_locked_page(mapping, wbc, page, end);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300630 put_page(page);
David Howells31143d52007-05-09 02:33:46 -0700631 if (ret < 0) {
632 _leave(" = %d", ret);
633 return ret;
634 }
635
636 wbc->nr_to_write -= ret;
637
David Howells31143d52007-05-09 02:33:46 -0700638 cond_resched();
639 } while (index < end && wbc->nr_to_write > 0);
640
641 *_next = index;
642 _leave(" = 0 [%lx]", *_next);
643 return 0;
644}
645
646/*
647 * write some of the pending data back to the server
648 */
649int afs_writepages(struct address_space *mapping,
650 struct writeback_control *wbc)
651{
David Howells31143d52007-05-09 02:33:46 -0700652 pgoff_t start, end, next;
653 int ret;
654
655 _enter("");
656
David Howells31143d52007-05-09 02:33:46 -0700657 if (wbc->range_cyclic) {
658 start = mapping->writeback_index;
659 end = -1;
660 ret = afs_writepages_region(mapping, wbc, start, end, &next);
Wu Fengguang1b430be2010-10-26 14:21:26 -0700661 if (start > 0 && wbc->nr_to_write > 0 && ret == 0)
David Howells31143d52007-05-09 02:33:46 -0700662 ret = afs_writepages_region(mapping, wbc, 0, start,
663 &next);
664 mapping->writeback_index = next;
665 } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300666 end = (pgoff_t)(LLONG_MAX >> PAGE_SHIFT);
David Howells31143d52007-05-09 02:33:46 -0700667 ret = afs_writepages_region(mapping, wbc, 0, end, &next);
668 if (wbc->nr_to_write > 0)
669 mapping->writeback_index = next;
670 } else {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300671 start = wbc->range_start >> PAGE_SHIFT;
672 end = wbc->range_end >> PAGE_SHIFT;
David Howells31143d52007-05-09 02:33:46 -0700673 ret = afs_writepages_region(mapping, wbc, start, end, &next);
674 }
675
676 _leave(" = %d", ret);
677 return ret;
678}
679
680/*
David Howells31143d52007-05-09 02:33:46 -0700681 * completion of write to server
682 */
683void afs_pages_written_back(struct afs_vnode *vnode, struct afs_call *call)
684{
David Howells31143d52007-05-09 02:33:46 -0700685 struct pagevec pv;
David Howells13524ab2017-11-02 15:27:53 +0000686 unsigned long priv;
David Howells31143d52007-05-09 02:33:46 -0700687 unsigned count, loop;
688 pgoff_t first = call->first, last = call->last;
David Howells31143d52007-05-09 02:33:46 -0700689
David Howells3b6492d2018-10-20 00:57:57 +0100690 _enter("{%llx:%llu},{%lx-%lx}",
David Howells31143d52007-05-09 02:33:46 -0700691 vnode->fid.vid, vnode->fid.vnode, first, last);
692
Mel Gorman86679822017-11-15 17:37:52 -0800693 pagevec_init(&pv);
David Howells31143d52007-05-09 02:33:46 -0700694
695 do {
David Howells5bbf5d32007-05-10 03:15:23 -0700696 _debug("done %lx-%lx", first, last);
David Howells31143d52007-05-09 02:33:46 -0700697
698 count = last - first + 1;
699 if (count > PAGEVEC_SIZE)
700 count = PAGEVEC_SIZE;
David Howells4343d002017-11-02 15:27:52 +0000701 pv.nr = find_get_pages_contig(vnode->vfs_inode.i_mapping,
702 first, count, pv.pages);
David Howells31143d52007-05-09 02:33:46 -0700703 ASSERTCMP(pv.nr, ==, count);
704
David Howells31143d52007-05-09 02:33:46 -0700705 for (loop = 0; loop < count; loop++) {
David Howells13524ab2017-11-02 15:27:53 +0000706 priv = page_private(pv.pages[loop]);
707 trace_afs_page_dirty(vnode, tracepoint_string("clear"),
708 pv.pages[loop]->index, priv);
David Howells4343d002017-11-02 15:27:52 +0000709 set_page_private(pv.pages[loop], 0);
710 end_page_writeback(pv.pages[loop]);
David Howells31143d52007-05-09 02:33:46 -0700711 }
David Howells31143d52007-05-09 02:33:46 -0700712 first += count;
David Howells31143d52007-05-09 02:33:46 -0700713 __pagevec_release(&pv);
David Howells5bbf5d32007-05-10 03:15:23 -0700714 } while (first <= last);
David Howells31143d52007-05-09 02:33:46 -0700715
David Howells4343d002017-11-02 15:27:52 +0000716 afs_prune_wb_keys(vnode);
David Howells31143d52007-05-09 02:33:46 -0700717 _leave("");
718}
719
720/*
721 * write to an AFS file
722 */
Al Viro50b55512014-04-03 14:13:46 -0400723ssize_t afs_file_write(struct kiocb *iocb, struct iov_iter *from)
David Howells31143d52007-05-09 02:33:46 -0700724{
Al Viro496ad9a2013-01-23 17:07:38 -0500725 struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp));
David Howells31143d52007-05-09 02:33:46 -0700726 ssize_t result;
Al Viro50b55512014-04-03 14:13:46 -0400727 size_t count = iov_iter_count(from);
David Howells31143d52007-05-09 02:33:46 -0700728
David Howells3b6492d2018-10-20 00:57:57 +0100729 _enter("{%llx:%llu},{%zu},",
Al Viro50b55512014-04-03 14:13:46 -0400730 vnode->fid.vid, vnode->fid.vnode, count);
David Howells31143d52007-05-09 02:33:46 -0700731
732 if (IS_SWAPFILE(&vnode->vfs_inode)) {
733 printk(KERN_INFO
734 "AFS: Attempt to write to active swap file!\n");
735 return -EBUSY;
736 }
737
738 if (!count)
739 return 0;
740
Al Viro50b55512014-04-03 14:13:46 -0400741 result = generic_file_write_iter(iocb, from);
David Howells31143d52007-05-09 02:33:46 -0700742
David Howells31143d52007-05-09 02:33:46 -0700743 _leave(" = %zd", result);
744 return result;
745}
746
747/*
David Howells31143d52007-05-09 02:33:46 -0700748 * flush any dirty pages for this process, and check for write errors.
749 * - the return status from this call provides a reliable indication of
750 * whether any write errors occurred for this process.
751 */
Josef Bacik02c24a82011-07-16 20:44:56 -0400752int afs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
David Howells31143d52007-05-09 02:33:46 -0700753{
Al Viro3c981bf2013-09-03 13:37:45 -0400754 struct inode *inode = file_inode(file);
Al Viro3c981bf2013-09-03 13:37:45 -0400755 struct afs_vnode *vnode = AFS_FS_I(inode);
David Howells31143d52007-05-09 02:33:46 -0700756
David Howells3b6492d2018-10-20 00:57:57 +0100757 _enter("{%llx:%llu},{n=%pD},%d",
Al Viro3c981bf2013-09-03 13:37:45 -0400758 vnode->fid.vid, vnode->fid.vnode, file,
David Howells31143d52007-05-09 02:33:46 -0700759 datasync);
760
David Howells4343d002017-11-02 15:27:52 +0000761 return file_write_and_wait_range(file, start, end);
David Howells31143d52007-05-09 02:33:46 -0700762}
David Howells9b3f26c2009-04-03 16:42:41 +0100763
764/*
765 * notification that a previously read-only page is about to become writable
766 * - if it returns an error, the caller will deliver a bus error signal
767 */
Souptick Joarder0722f182018-08-23 17:00:48 -0700768vm_fault_t afs_page_mkwrite(struct vm_fault *vmf)
David Howells9b3f26c2009-04-03 16:42:41 +0100769{
David Howells1cf7a152017-11-02 15:27:52 +0000770 struct file *file = vmf->vma->vm_file;
771 struct inode *inode = file_inode(file);
772 struct afs_vnode *vnode = AFS_FS_I(inode);
773 unsigned long priv;
David Howells9b3f26c2009-04-03 16:42:41 +0100774
David Howells3b6492d2018-10-20 00:57:57 +0100775 _enter("{{%llx:%llu}},{%lx}",
David Howells1cf7a152017-11-02 15:27:52 +0000776 vnode->fid.vid, vnode->fid.vnode, vmf->page->index);
David Howells9b3f26c2009-04-03 16:42:41 +0100777
David Howells1cf7a152017-11-02 15:27:52 +0000778 sb_start_pagefault(inode->i_sb);
779
780 /* Wait for the page to be written to the cache before we allow it to
781 * be modified. We then assume the entire page will need writing back.
782 */
David Howells9b3f26c2009-04-03 16:42:41 +0100783#ifdef CONFIG_AFS_FSCACHE
David Howells1cf7a152017-11-02 15:27:52 +0000784 fscache_wait_on_page_write(vnode->cache, vmf->page);
David Howells9b3f26c2009-04-03 16:42:41 +0100785#endif
786
David Howells1cf7a152017-11-02 15:27:52 +0000787 if (PageWriteback(vmf->page) &&
788 wait_on_page_bit_killable(vmf->page, PG_writeback) < 0)
789 return VM_FAULT_RETRY;
790
791 if (lock_page_killable(vmf->page) < 0)
792 return VM_FAULT_RETRY;
793
794 /* We mustn't change page->private until writeback is complete as that
795 * details the portion of the page we need to write back and we might
796 * need to redirty the page if there's a problem.
797 */
798 wait_on_page_writeback(vmf->page);
799
800 priv = (unsigned long)PAGE_SIZE << AFS_PRIV_SHIFT; /* To */
801 priv |= 0; /* From */
David Howells13524ab2017-11-02 15:27:53 +0000802 trace_afs_page_dirty(vnode, tracepoint_string("mkwrite"),
803 vmf->page->index, priv);
David Howells1cf7a152017-11-02 15:27:52 +0000804 SetPagePrivate(vmf->page);
805 set_page_private(vmf->page, priv);
806
807 sb_end_pagefault(inode->i_sb);
808 return VM_FAULT_LOCKED;
David Howells9b3f26c2009-04-03 16:42:41 +0100809}
David Howells4343d002017-11-02 15:27:52 +0000810
811/*
812 * Prune the keys cached for writeback. The caller must hold vnode->wb_lock.
813 */
814void afs_prune_wb_keys(struct afs_vnode *vnode)
815{
816 LIST_HEAD(graveyard);
817 struct afs_wb_key *wbk, *tmp;
818
819 /* Discard unused keys */
820 spin_lock(&vnode->wb_lock);
821
822 if (!mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_WRITEBACK) &&
823 !mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_DIRTY)) {
824 list_for_each_entry_safe(wbk, tmp, &vnode->wb_keys, vnode_link) {
825 if (refcount_read(&wbk->usage) == 1)
826 list_move(&wbk->vnode_link, &graveyard);
827 }
828 }
829
830 spin_unlock(&vnode->wb_lock);
831
832 while (!list_empty(&graveyard)) {
833 wbk = list_entry(graveyard.next, struct afs_wb_key, vnode_link);
834 list_del(&wbk->vnode_link);
835 afs_put_wb_key(wbk);
836 }
837}
838
839/*
840 * Clean up a page during invalidation.
841 */
842int afs_launder_page(struct page *page)
843{
844 struct address_space *mapping = page->mapping;
845 struct afs_vnode *vnode = AFS_FS_I(mapping->host);
846 unsigned long priv;
847 unsigned int f, t;
848 int ret = 0;
849
850 _enter("{%lx}", page->index);
851
852 priv = page_private(page);
853 if (clear_page_dirty_for_io(page)) {
854 f = 0;
855 t = PAGE_SIZE;
856 if (PagePrivate(page)) {
857 f = priv & AFS_PRIV_MAX;
858 t = priv >> AFS_PRIV_SHIFT;
859 }
860
David Howells13524ab2017-11-02 15:27:53 +0000861 trace_afs_page_dirty(vnode, tracepoint_string("launder"),
862 page->index, priv);
David Howells4343d002017-11-02 15:27:52 +0000863 ret = afs_store_data(mapping, page->index, page->index, t, f);
864 }
865
David Howells13524ab2017-11-02 15:27:53 +0000866 trace_afs_page_dirty(vnode, tracepoint_string("laundered"),
867 page->index, priv);
David Howells4343d002017-11-02 15:27:52 +0000868 set_page_private(page, 0);
869 ClearPagePrivate(page);
870
871#ifdef CONFIG_AFS_FSCACHE
872 if (PageFsCache(page)) {
873 fscache_wait_on_page_write(vnode->cache, page);
874 fscache_uncache_page(vnode->cache, page);
875 }
876#endif
877 return ret;
David Howells31143d52007-05-09 02:33:46 -0700878}