blob: 8b39e6ebb40bc17905cf2eca24b1eacadf933584 [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 (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
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 Howells31143d52007-05-09 02:33:46 -070036 int ret;
37
Anton Blanchard5e7f2332011-06-13 22:31:12 +010038 _enter(",,%llu", (unsigned long long)pos);
David Howells31143d52007-05-09 02:33:46 -070039
David Howells196ee9c2017-01-05 10:38:34 +000040 req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
41 GFP_KERNEL);
42 if (!req)
43 return -ENOMEM;
44
David Howellsf3ddee82018-04-06 14:17:25 +010045 refcount_set(&req->usage, 1);
David Howells196ee9c2017-01-05 10:38:34 +000046 req->pos = pos;
David Howellse8e581a2017-03-16 16:27:44 +000047 req->len = len;
David Howells196ee9c2017-01-05 10:38:34 +000048 req->nr_pages = 1;
David Howellsf3ddee82018-04-06 14:17:25 +010049 req->pages = req->array;
David Howells196ee9c2017-01-05 10:38:34 +000050 req->pages[0] = page;
David Howells5611ef22017-03-16 16:27:43 +000051 get_page(page);
David Howells196ee9c2017-01-05 10:38:34 +000052
David Howellsd2ddc772017-11-02 15:27:50 +000053 ret = afs_fetch_data(vnode, key, req);
David Howells196ee9c2017-01-05 10:38:34 +000054 afs_put_read(req);
David Howells31143d52007-05-09 02:33:46 -070055 if (ret < 0) {
56 if (ret == -ENOENT) {
57 _debug("got NOENT from server"
58 " - marking file deleted and stale");
59 set_bit(AFS_VNODE_DELETED, &vnode->flags);
60 ret = -ESTALE;
61 }
62 }
63
64 _leave(" = %d", ret);
65 return ret;
66}
67
68/*
David Howells31143d52007-05-09 02:33:46 -070069 * prepare to perform part of a write to a page
David Howells31143d52007-05-09 02:33:46 -070070 */
Nick Piggin15b46502008-10-15 22:04:32 -070071int afs_write_begin(struct file *file, struct address_space *mapping,
72 loff_t pos, unsigned len, unsigned flags,
73 struct page **pagep, void **fsdata)
David Howells31143d52007-05-09 02:33:46 -070074{
Al Viro496ad9a2013-01-23 17:07:38 -050075 struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
Nick Piggin15b46502008-10-15 22:04:32 -070076 struct page *page;
David Howells215804a2017-11-02 15:27:52 +000077 struct key *key = afs_file_key(file);
David Howells4343d002017-11-02 15:27:52 +000078 unsigned long priv;
79 unsigned f, from = pos & (PAGE_SIZE - 1);
80 unsigned t, to = from + len;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +030081 pgoff_t index = pos >> PAGE_SHIFT;
David Howells31143d52007-05-09 02:33:46 -070082 int ret;
83
84 _enter("{%x:%u},{%lx},%u,%u",
Nick Piggin15b46502008-10-15 22:04:32 -070085 vnode->fid.vid, vnode->fid.vnode, index, from, to);
David Howells31143d52007-05-09 02:33:46 -070086
David Howells4343d002017-11-02 15:27:52 +000087 /* We want to store information about how much of a page is altered in
88 * page->private.
89 */
90 BUILD_BUG_ON(PAGE_SIZE > 32768 && sizeof(page->private) < 8);
David Howells31143d52007-05-09 02:33:46 -070091
Nick Piggin54566b22009-01-04 12:00:53 -080092 page = grab_cache_page_write_begin(mapping, index, flags);
David Howells4343d002017-11-02 15:27:52 +000093 if (!page)
Nick Piggin15b46502008-10-15 22:04:32 -070094 return -ENOMEM;
Nick Piggin15b46502008-10-15 22:04:32 -070095
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +030096 if (!PageUptodate(page) && len != PAGE_SIZE) {
David Howellse8e581a2017-03-16 16:27:44 +000097 ret = afs_fill_page(vnode, key, pos & PAGE_MASK, PAGE_SIZE, page);
David Howells31143d52007-05-09 02:33:46 -070098 if (ret < 0) {
David Howells6d06b0d2017-03-16 16:27:48 +000099 unlock_page(page);
100 put_page(page);
David Howells31143d52007-05-09 02:33:46 -0700101 _leave(" = %d [prep]", ret);
102 return ret;
103 }
Nick Piggin15b46502008-10-15 22:04:32 -0700104 SetPageUptodate(page);
David Howells31143d52007-05-09 02:33:46 -0700105 }
106
David Howells6d06b0d2017-03-16 16:27:48 +0000107 /* page won't leak in error case: it eventually gets cleaned off LRU */
108 *pagep = page;
109
David Howells31143d52007-05-09 02:33:46 -0700110try_again:
David Howells4343d002017-11-02 15:27:52 +0000111 /* See if this page is already partially written in a way that we can
112 * merge the new write with.
113 */
114 t = f = 0;
115 if (PagePrivate(page)) {
116 priv = page_private(page);
117 f = priv & AFS_PRIV_MAX;
118 t = priv >> AFS_PRIV_SHIFT;
119 ASSERTCMP(f, <=, t);
David Howells31143d52007-05-09 02:33:46 -0700120 }
121
David Howells4343d002017-11-02 15:27:52 +0000122 if (f != t) {
David Howells5a039c32017-11-18 00:13:30 +0000123 if (PageWriteback(page)) {
124 trace_afs_page_dirty(vnode, tracepoint_string("alrdy"),
125 page->index, priv);
126 goto flush_conflicting_write;
127 }
David Howells5a813272018-04-06 14:17:26 +0100128 /* If the file is being filled locally, allow inter-write
129 * spaces to be merged into writes. If it's not, only write
130 * back what the user gives us.
131 */
132 if (!test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags) &&
133 (to < f || from > t))
David Howells4343d002017-11-02 15:27:52 +0000134 goto flush_conflicting_write;
135 if (from < f)
136 f = from;
137 if (to > t)
138 t = to;
139 } else {
140 f = from;
141 t = to;
David Howells31143d52007-05-09 02:33:46 -0700142 }
143
David Howells4343d002017-11-02 15:27:52 +0000144 priv = (unsigned long)t << AFS_PRIV_SHIFT;
145 priv |= f;
David Howells13524ab2017-11-02 15:27:53 +0000146 trace_afs_page_dirty(vnode, tracepoint_string("begin"),
147 page->index, priv);
David Howells31143d52007-05-09 02:33:46 -0700148 SetPagePrivate(page);
David Howells4343d002017-11-02 15:27:52 +0000149 set_page_private(page, priv);
150 _leave(" = 0");
David Howells31143d52007-05-09 02:33:46 -0700151 return 0;
152
David Howells4343d002017-11-02 15:27:52 +0000153 /* The previous write and this write aren't adjacent or overlapping, so
154 * flush the page out.
155 */
156flush_conflicting_write:
David Howells31143d52007-05-09 02:33:46 -0700157 _debug("flush conflict");
David Howells4343d002017-11-02 15:27:52 +0000158 ret = write_one_page(page);
159 if (ret < 0) {
160 _leave(" = %d", ret);
161 return ret;
David Howells31143d52007-05-09 02:33:46 -0700162 }
163
David Howells4343d002017-11-02 15:27:52 +0000164 ret = lock_page_killable(page);
165 if (ret < 0) {
166 _leave(" = %d", ret);
167 return ret;
168 }
David Howells31143d52007-05-09 02:33:46 -0700169 goto try_again;
170}
171
172/*
173 * finalise part of a write to a page
174 */
Nick Piggin15b46502008-10-15 22:04:32 -0700175int afs_write_end(struct file *file, struct address_space *mapping,
176 loff_t pos, unsigned len, unsigned copied,
177 struct page *page, void *fsdata)
David Howells31143d52007-05-09 02:33:46 -0700178{
Al Viro496ad9a2013-01-23 17:07:38 -0500179 struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
David Howells215804a2017-11-02 15:27:52 +0000180 struct key *key = afs_file_key(file);
David Howells31143d52007-05-09 02:33:46 -0700181 loff_t i_size, maybe_i_size;
David Howellse8e581a2017-03-16 16:27:44 +0000182 int ret;
David Howells31143d52007-05-09 02:33:46 -0700183
Nick Piggin15b46502008-10-15 22:04:32 -0700184 _enter("{%x:%u},{%lx}",
185 vnode->fid.vid, vnode->fid.vnode, page->index);
David Howells31143d52007-05-09 02:33:46 -0700186
Nick Piggin15b46502008-10-15 22:04:32 -0700187 maybe_i_size = pos + copied;
David Howells31143d52007-05-09 02:33:46 -0700188
189 i_size = i_size_read(&vnode->vfs_inode);
190 if (maybe_i_size > i_size) {
David Howells4343d002017-11-02 15:27:52 +0000191 spin_lock(&vnode->wb_lock);
David Howells31143d52007-05-09 02:33:46 -0700192 i_size = i_size_read(&vnode->vfs_inode);
193 if (maybe_i_size > i_size)
194 i_size_write(&vnode->vfs_inode, maybe_i_size);
David Howells4343d002017-11-02 15:27:52 +0000195 spin_unlock(&vnode->wb_lock);
David Howells31143d52007-05-09 02:33:46 -0700196 }
197
David Howellse8e581a2017-03-16 16:27:44 +0000198 if (!PageUptodate(page)) {
199 if (copied < len) {
200 /* Try and load any missing data from the server. The
201 * unmarshalling routine will take care of clearing any
202 * bits that are beyond the EOF.
203 */
204 ret = afs_fill_page(vnode, key, pos + copied,
205 len - copied, page);
206 if (ret < 0)
David Howellsafae4572018-01-02 10:02:19 +0000207 goto out;
David Howellse8e581a2017-03-16 16:27:44 +0000208 }
209 SetPageUptodate(page);
210 }
211
David Howells31143d52007-05-09 02:33:46 -0700212 set_page_dirty(page);
David Howells31143d52007-05-09 02:33:46 -0700213 if (PageDirty(page))
214 _debug("dirtied");
David Howellsafae4572018-01-02 10:02:19 +0000215 ret = copied;
216
217out:
Nick Piggin15b46502008-10-15 22:04:32 -0700218 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300219 put_page(page);
David Howellsafae4572018-01-02 10:02:19 +0000220 return ret;
David Howells31143d52007-05-09 02:33:46 -0700221}
222
223/*
224 * kill all the pages in the given range
225 */
David Howells4343d002017-11-02 15:27:52 +0000226static void afs_kill_pages(struct address_space *mapping,
David Howells31143d52007-05-09 02:33:46 -0700227 pgoff_t first, pgoff_t last)
228{
David Howells4343d002017-11-02 15:27:52 +0000229 struct afs_vnode *vnode = AFS_FS_I(mapping->host);
David Howells31143d52007-05-09 02:33:46 -0700230 struct pagevec pv;
231 unsigned count, loop;
232
233 _enter("{%x:%u},%lx-%lx",
234 vnode->fid.vid, vnode->fid.vnode, first, last);
235
Mel Gorman86679822017-11-15 17:37:52 -0800236 pagevec_init(&pv);
David Howells31143d52007-05-09 02:33:46 -0700237
238 do {
239 _debug("kill %lx-%lx", first, last);
240
241 count = last - first + 1;
242 if (count > PAGEVEC_SIZE)
243 count = PAGEVEC_SIZE;
David Howells4343d002017-11-02 15:27:52 +0000244 pv.nr = find_get_pages_contig(mapping, first, count, pv.pages);
David Howells31143d52007-05-09 02:33:46 -0700245 ASSERTCMP(pv.nr, ==, count);
246
247 for (loop = 0; loop < count; loop++) {
David Howells7286a352017-03-16 16:27:48 +0000248 struct page *page = pv.pages[loop];
249 ClearPageUptodate(page);
David Howells4343d002017-11-02 15:27:52 +0000250 SetPageError(page);
251 end_page_writeback(page);
David Howells7286a352017-03-16 16:27:48 +0000252 if (page->index >= first)
253 first = page->index + 1;
David Howells4343d002017-11-02 15:27:52 +0000254 lock_page(page);
255 generic_error_remove_page(mapping, page);
David Howells31143d52007-05-09 02:33:46 -0700256 }
257
258 __pagevec_release(&pv);
David Howells4343d002017-11-02 15:27:52 +0000259 } while (first <= last);
David Howells31143d52007-05-09 02:33:46 -0700260
261 _leave("");
262}
263
264/*
David Howells4343d002017-11-02 15:27:52 +0000265 * Redirty all the pages in a given range.
David Howells31143d52007-05-09 02:33:46 -0700266 */
David Howells4343d002017-11-02 15:27:52 +0000267static void afs_redirty_pages(struct writeback_control *wbc,
268 struct address_space *mapping,
269 pgoff_t first, pgoff_t last)
David Howells31143d52007-05-09 02:33:46 -0700270{
David Howells4343d002017-11-02 15:27:52 +0000271 struct afs_vnode *vnode = AFS_FS_I(mapping->host);
272 struct pagevec pv;
273 unsigned count, loop;
274
275 _enter("{%x:%u},%lx-%lx",
276 vnode->fid.vid, vnode->fid.vnode, first, last);
277
Linus Torvalds487e2c92017-11-16 11:41:22 -0800278 pagevec_init(&pv);
David Howells4343d002017-11-02 15:27:52 +0000279
280 do {
281 _debug("redirty %lx-%lx", first, last);
282
283 count = last - first + 1;
284 if (count > PAGEVEC_SIZE)
285 count = PAGEVEC_SIZE;
286 pv.nr = find_get_pages_contig(mapping, first, count, pv.pages);
287 ASSERTCMP(pv.nr, ==, count);
288
289 for (loop = 0; loop < count; loop++) {
290 struct page *page = pv.pages[loop];
291
292 redirty_page_for_writepage(wbc, page);
293 end_page_writeback(page);
David Howells31143d52007-05-09 02:33:46 -0700294 if (page->index >= first)
295 first = page->index + 1;
296 }
297
298 __pagevec_release(&pv);
David Howells4343d002017-11-02 15:27:52 +0000299 } while (first <= last);
David Howells31143d52007-05-09 02:33:46 -0700300
301 _leave("");
302}
303
304/*
David Howellsd2ddc772017-11-02 15:27:50 +0000305 * write to a file
306 */
David Howells4343d002017-11-02 15:27:52 +0000307static int afs_store_data(struct address_space *mapping,
308 pgoff_t first, pgoff_t last,
David Howellsd2ddc772017-11-02 15:27:50 +0000309 unsigned offset, unsigned to)
310{
David Howells4343d002017-11-02 15:27:52 +0000311 struct afs_vnode *vnode = AFS_FS_I(mapping->host);
David Howellsd2ddc772017-11-02 15:27:50 +0000312 struct afs_fs_cursor fc;
David Howells4343d002017-11-02 15:27:52 +0000313 struct afs_wb_key *wbk = NULL;
314 struct list_head *p;
315 int ret = -ENOKEY, ret2;
David Howellsd2ddc772017-11-02 15:27:50 +0000316
David Howells4343d002017-11-02 15:27:52 +0000317 _enter("%s{%x:%u.%u},%lx,%lx,%x,%x",
David Howellsd2ddc772017-11-02 15:27:50 +0000318 vnode->volume->name,
319 vnode->fid.vid,
320 vnode->fid.vnode,
321 vnode->fid.unique,
David Howellsd2ddc772017-11-02 15:27:50 +0000322 first, last, offset, to);
323
David Howells4343d002017-11-02 15:27:52 +0000324 spin_lock(&vnode->wb_lock);
325 p = vnode->wb_keys.next;
326
327 /* Iterate through the list looking for a valid key to use. */
328try_next_key:
329 while (p != &vnode->wb_keys) {
330 wbk = list_entry(p, struct afs_wb_key, vnode_link);
331 _debug("wbk %u", key_serial(wbk->key));
332 ret2 = key_validate(wbk->key);
333 if (ret2 == 0)
334 goto found_key;
335 if (ret == -ENOKEY)
336 ret = ret2;
337 p = p->next;
338 }
339
340 spin_unlock(&vnode->wb_lock);
341 afs_put_wb_key(wbk);
342 _leave(" = %d [no keys]", ret);
343 return ret;
344
345found_key:
346 refcount_inc(&wbk->usage);
347 spin_unlock(&vnode->wb_lock);
348
349 _debug("USE WB KEY %u", key_serial(wbk->key));
350
David Howellsd2ddc772017-11-02 15:27:50 +0000351 ret = -ERESTARTSYS;
David Howells4343d002017-11-02 15:27:52 +0000352 if (afs_begin_vnode_operation(&fc, vnode, wbk->key)) {
David Howellsd2ddc772017-11-02 15:27:50 +0000353 while (afs_select_fileserver(&fc)) {
David Howells68251f02018-05-12 22:31:33 +0100354 fc.cb_break = afs_calc_vnode_cb_break(vnode);
David Howells4343d002017-11-02 15:27:52 +0000355 afs_fs_store_data(&fc, mapping, first, last, offset, to);
David Howellsd2ddc772017-11-02 15:27:50 +0000356 }
357
358 afs_check_for_remote_deletion(&fc, fc.vnode);
359 afs_vnode_commit_status(&fc, vnode, fc.cb_break);
360 ret = afs_end_vnode_operation(&fc);
361 }
362
David Howells4343d002017-11-02 15:27:52 +0000363 switch (ret) {
David Howells76a5cb62018-04-06 14:17:26 +0100364 case 0:
365 afs_stat_v(vnode, n_stores);
366 atomic_long_add((last * PAGE_SIZE + to) -
367 (first * PAGE_SIZE + offset),
368 &afs_v2net(vnode)->n_store_bytes);
369 break;
David Howells4343d002017-11-02 15:27:52 +0000370 case -EACCES:
371 case -EPERM:
372 case -ENOKEY:
373 case -EKEYEXPIRED:
374 case -EKEYREJECTED:
375 case -EKEYREVOKED:
376 _debug("next");
377 spin_lock(&vnode->wb_lock);
378 p = wbk->vnode_link.next;
379 afs_put_wb_key(wbk);
380 goto try_next_key;
381 }
382
383 afs_put_wb_key(wbk);
David Howellsd2ddc772017-11-02 15:27:50 +0000384 _leave(" = %d", ret);
385 return ret;
386}
387
388/*
David Howells4343d002017-11-02 15:27:52 +0000389 * Synchronously write back the locked page and any subsequent non-locked dirty
390 * pages.
David Howells31143d52007-05-09 02:33:46 -0700391 */
David Howells4343d002017-11-02 15:27:52 +0000392static int afs_write_back_from_locked_page(struct address_space *mapping,
393 struct writeback_control *wbc,
394 struct page *primary_page,
395 pgoff_t final_page)
David Howells31143d52007-05-09 02:33:46 -0700396{
David Howells13524ab2017-11-02 15:27:53 +0000397 struct afs_vnode *vnode = AFS_FS_I(mapping->host);
David Howells31143d52007-05-09 02:33:46 -0700398 struct page *pages[8], *page;
David Howells4343d002017-11-02 15:27:52 +0000399 unsigned long count, priv;
400 unsigned n, offset, to, f, t;
David Howells31143d52007-05-09 02:33:46 -0700401 pgoff_t start, first, last;
402 int loop, ret;
403
404 _enter(",%lx", primary_page->index);
405
406 count = 1;
David Howells31143d52007-05-09 02:33:46 -0700407 if (test_set_page_writeback(primary_page))
408 BUG();
409
David Howells4343d002017-11-02 15:27:52 +0000410 /* Find all consecutive lockable dirty pages that have contiguous
411 * written regions, stopping when we find a page that is not
412 * immediately lockable, is not dirty or is missing, or we reach the
413 * end of the range.
414 */
David Howells31143d52007-05-09 02:33:46 -0700415 start = primary_page->index;
David Howells4343d002017-11-02 15:27:52 +0000416 priv = page_private(primary_page);
417 offset = priv & AFS_PRIV_MAX;
418 to = priv >> AFS_PRIV_SHIFT;
David Howells13524ab2017-11-02 15:27:53 +0000419 trace_afs_page_dirty(vnode, tracepoint_string("store"),
420 primary_page->index, priv);
David Howells4343d002017-11-02 15:27:52 +0000421
422 WARN_ON(offset == to);
David Howells13524ab2017-11-02 15:27:53 +0000423 if (offset == to)
424 trace_afs_page_dirty(vnode, tracepoint_string("WARN"),
425 primary_page->index, priv);
David Howells4343d002017-11-02 15:27:52 +0000426
David Howells5a813272018-04-06 14:17:26 +0100427 if (start >= final_page ||
428 (to < PAGE_SIZE && !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)))
David Howells31143d52007-05-09 02:33:46 -0700429 goto no_more;
David Howells4343d002017-11-02 15:27:52 +0000430
David Howells31143d52007-05-09 02:33:46 -0700431 start++;
432 do {
433 _debug("more %lx [%lx]", start, count);
David Howells4343d002017-11-02 15:27:52 +0000434 n = final_page - start + 1;
David Howells31143d52007-05-09 02:33:46 -0700435 if (n > ARRAY_SIZE(pages))
436 n = ARRAY_SIZE(pages);
David Howells4343d002017-11-02 15:27:52 +0000437 n = find_get_pages_contig(mapping, start, ARRAY_SIZE(pages), pages);
David Howells31143d52007-05-09 02:33:46 -0700438 _debug("fgpc %u", n);
439 if (n == 0)
440 goto no_more;
441 if (pages[0]->index != start) {
David Howells9d577b62007-05-10 22:22:19 -0700442 do {
443 put_page(pages[--n]);
444 } while (n > 0);
David Howells31143d52007-05-09 02:33:46 -0700445 goto no_more;
446 }
447
448 for (loop = 0; loop < n; loop++) {
449 page = pages[loop];
David Howells5a813272018-04-06 14:17:26 +0100450 if (to != PAGE_SIZE &&
451 !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags))
452 break;
David Howells4343d002017-11-02 15:27:52 +0000453 if (page->index > final_page)
David Howells31143d52007-05-09 02:33:46 -0700454 break;
Nick Piggin529ae9a2008-08-02 12:01:03 +0200455 if (!trylock_page(page))
David Howells31143d52007-05-09 02:33:46 -0700456 break;
David Howells4343d002017-11-02 15:27:52 +0000457 if (!PageDirty(page) || PageWriteback(page)) {
David Howells31143d52007-05-09 02:33:46 -0700458 unlock_page(page);
459 break;
460 }
David Howells4343d002017-11-02 15:27:52 +0000461
462 priv = page_private(page);
463 f = priv & AFS_PRIV_MAX;
464 t = priv >> AFS_PRIV_SHIFT;
David Howells5a813272018-04-06 14:17:26 +0100465 if (f != 0 &&
466 !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)) {
David Howells4343d002017-11-02 15:27:52 +0000467 unlock_page(page);
468 break;
469 }
470 to = t;
471
David Howells13524ab2017-11-02 15:27:53 +0000472 trace_afs_page_dirty(vnode, tracepoint_string("store+"),
473 page->index, priv);
474
David Howells31143d52007-05-09 02:33:46 -0700475 if (!clear_page_dirty_for_io(page))
476 BUG();
477 if (test_set_page_writeback(page))
478 BUG();
479 unlock_page(page);
480 put_page(page);
481 }
482 count += loop;
483 if (loop < n) {
484 for (; loop < n; loop++)
485 put_page(pages[loop]);
486 goto no_more;
487 }
488
489 start += loop;
David Howells4343d002017-11-02 15:27:52 +0000490 } while (start <= final_page && count < 65536);
David Howells31143d52007-05-09 02:33:46 -0700491
492no_more:
David Howells4343d002017-11-02 15:27:52 +0000493 /* We now have a contiguous set of dirty pages, each with writeback
494 * set; the first page is still locked at this point, but all the rest
495 * have been unlocked.
496 */
497 unlock_page(primary_page);
498
David Howells31143d52007-05-09 02:33:46 -0700499 first = primary_page->index;
500 last = first + count - 1;
501
David Howells31143d52007-05-09 02:33:46 -0700502 _debug("write back %lx[%u..] to %lx[..%u]", first, offset, last, to);
503
David Howells4343d002017-11-02 15:27:52 +0000504 ret = afs_store_data(mapping, first, last, offset, to);
505 switch (ret) {
506 case 0:
David Howells31143d52007-05-09 02:33:46 -0700507 ret = count;
David Howells4343d002017-11-02 15:27:52 +0000508 break;
509
510 default:
511 pr_notice("kAFS: Unexpected error from FS.StoreData %d\n", ret);
512 /* Fall through */
513 case -EACCES:
514 case -EPERM:
515 case -ENOKEY:
516 case -EKEYEXPIRED:
517 case -EKEYREJECTED:
518 case -EKEYREVOKED:
519 afs_redirty_pages(wbc, mapping, first, last);
520 mapping_set_error(mapping, ret);
521 break;
522
523 case -EDQUOT:
524 case -ENOSPC:
525 afs_redirty_pages(wbc, mapping, first, last);
526 mapping_set_error(mapping, -ENOSPC);
527 break;
528
529 case -EROFS:
530 case -EIO:
531 case -EREMOTEIO:
532 case -EFBIG:
533 case -ENOENT:
534 case -ENOMEDIUM:
535 case -ENXIO:
536 afs_kill_pages(mapping, first, last);
537 mapping_set_error(mapping, ret);
538 break;
David Howells31143d52007-05-09 02:33:46 -0700539 }
540
541 _leave(" = %d", ret);
542 return ret;
543}
544
545/*
546 * write a page back to the server
547 * - the caller locked the page for us
548 */
549int afs_writepage(struct page *page, struct writeback_control *wbc)
550{
David Howells31143d52007-05-09 02:33:46 -0700551 int ret;
552
553 _enter("{%lx},", page->index);
554
David Howells4343d002017-11-02 15:27:52 +0000555 ret = afs_write_back_from_locked_page(page->mapping, wbc, page,
556 wbc->range_end >> PAGE_SHIFT);
David Howells31143d52007-05-09 02:33:46 -0700557 if (ret < 0) {
558 _leave(" = %d", ret);
559 return 0;
560 }
561
562 wbc->nr_to_write -= ret;
David Howells31143d52007-05-09 02:33:46 -0700563
564 _leave(" = 0");
565 return 0;
566}
567
568/*
569 * write a region of pages back to the server
570 */
Adrian Bunkc1206a22007-10-16 23:26:41 -0700571static int afs_writepages_region(struct address_space *mapping,
572 struct writeback_control *wbc,
573 pgoff_t index, pgoff_t end, pgoff_t *_next)
David Howells31143d52007-05-09 02:33:46 -0700574{
David Howells31143d52007-05-09 02:33:46 -0700575 struct page *page;
576 int ret, n;
577
578 _enter(",,%lx,%lx,", index, end);
579
580 do {
Jan Karaaef6e412017-11-15 17:35:23 -0800581 n = find_get_pages_range_tag(mapping, &index, end,
582 PAGECACHE_TAG_DIRTY, 1, &page);
David Howells31143d52007-05-09 02:33:46 -0700583 if (!n)
584 break;
585
586 _debug("wback %lx", page->index);
587
Matthew Wilcoxb93b0162018-04-10 16:36:56 -0700588 /*
589 * at this point we hold neither the i_pages lock nor the
590 * page lock: the page may be truncated or invalidated
591 * (changing page->mapping to NULL), or even swizzled
592 * back from swapper_space to tmpfs file mapping
David Howells31143d52007-05-09 02:33:46 -0700593 */
David Howells4343d002017-11-02 15:27:52 +0000594 ret = lock_page_killable(page);
595 if (ret < 0) {
596 put_page(page);
597 _leave(" = %d", ret);
598 return ret;
599 }
David Howells31143d52007-05-09 02:33:46 -0700600
David Howellsc5051c72017-03-16 16:27:49 +0000601 if (page->mapping != mapping || !PageDirty(page)) {
David Howells31143d52007-05-09 02:33:46 -0700602 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300603 put_page(page);
David Howells31143d52007-05-09 02:33:46 -0700604 continue;
605 }
606
David Howellsc5051c72017-03-16 16:27:49 +0000607 if (PageWriteback(page)) {
David Howells31143d52007-05-09 02:33:46 -0700608 unlock_page(page);
David Howellsc5051c72017-03-16 16:27:49 +0000609 if (wbc->sync_mode != WB_SYNC_NONE)
610 wait_on_page_writeback(page);
David Howells29c8bbb2017-03-16 16:27:43 +0000611 put_page(page);
David Howells31143d52007-05-09 02:33:46 -0700612 continue;
613 }
614
David Howells65a15102017-03-16 16:27:49 +0000615 if (!clear_page_dirty_for_io(page))
616 BUG();
David Howells4343d002017-11-02 15:27:52 +0000617 ret = afs_write_back_from_locked_page(mapping, wbc, page, end);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300618 put_page(page);
David Howells31143d52007-05-09 02:33:46 -0700619 if (ret < 0) {
620 _leave(" = %d", ret);
621 return ret;
622 }
623
624 wbc->nr_to_write -= ret;
625
David Howells31143d52007-05-09 02:33:46 -0700626 cond_resched();
627 } while (index < end && wbc->nr_to_write > 0);
628
629 *_next = index;
630 _leave(" = 0 [%lx]", *_next);
631 return 0;
632}
633
634/*
635 * write some of the pending data back to the server
636 */
637int afs_writepages(struct address_space *mapping,
638 struct writeback_control *wbc)
639{
David Howells31143d52007-05-09 02:33:46 -0700640 pgoff_t start, end, next;
641 int ret;
642
643 _enter("");
644
David Howells31143d52007-05-09 02:33:46 -0700645 if (wbc->range_cyclic) {
646 start = mapping->writeback_index;
647 end = -1;
648 ret = afs_writepages_region(mapping, wbc, start, end, &next);
Wu Fengguang1b430be2010-10-26 14:21:26 -0700649 if (start > 0 && wbc->nr_to_write > 0 && ret == 0)
David Howells31143d52007-05-09 02:33:46 -0700650 ret = afs_writepages_region(mapping, wbc, 0, start,
651 &next);
652 mapping->writeback_index = next;
653 } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300654 end = (pgoff_t)(LLONG_MAX >> PAGE_SHIFT);
David Howells31143d52007-05-09 02:33:46 -0700655 ret = afs_writepages_region(mapping, wbc, 0, end, &next);
656 if (wbc->nr_to_write > 0)
657 mapping->writeback_index = next;
658 } else {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300659 start = wbc->range_start >> PAGE_SHIFT;
660 end = wbc->range_end >> PAGE_SHIFT;
David Howells31143d52007-05-09 02:33:46 -0700661 ret = afs_writepages_region(mapping, wbc, start, end, &next);
662 }
663
664 _leave(" = %d", ret);
665 return ret;
666}
667
668/*
David Howells31143d52007-05-09 02:33:46 -0700669 * completion of write to server
670 */
671void afs_pages_written_back(struct afs_vnode *vnode, struct afs_call *call)
672{
David Howells31143d52007-05-09 02:33:46 -0700673 struct pagevec pv;
David Howells13524ab2017-11-02 15:27:53 +0000674 unsigned long priv;
David Howells31143d52007-05-09 02:33:46 -0700675 unsigned count, loop;
676 pgoff_t first = call->first, last = call->last;
David Howells31143d52007-05-09 02:33:46 -0700677
678 _enter("{%x:%u},{%lx-%lx}",
679 vnode->fid.vid, vnode->fid.vnode, first, last);
680
Mel Gorman86679822017-11-15 17:37:52 -0800681 pagevec_init(&pv);
David Howells31143d52007-05-09 02:33:46 -0700682
683 do {
David Howells5bbf5d32007-05-10 03:15:23 -0700684 _debug("done %lx-%lx", first, last);
David Howells31143d52007-05-09 02:33:46 -0700685
686 count = last - first + 1;
687 if (count > PAGEVEC_SIZE)
688 count = PAGEVEC_SIZE;
David Howells4343d002017-11-02 15:27:52 +0000689 pv.nr = find_get_pages_contig(vnode->vfs_inode.i_mapping,
690 first, count, pv.pages);
David Howells31143d52007-05-09 02:33:46 -0700691 ASSERTCMP(pv.nr, ==, count);
692
David Howells31143d52007-05-09 02:33:46 -0700693 for (loop = 0; loop < count; loop++) {
David Howells13524ab2017-11-02 15:27:53 +0000694 priv = page_private(pv.pages[loop]);
695 trace_afs_page_dirty(vnode, tracepoint_string("clear"),
696 pv.pages[loop]->index, priv);
David Howells4343d002017-11-02 15:27:52 +0000697 set_page_private(pv.pages[loop], 0);
698 end_page_writeback(pv.pages[loop]);
David Howells31143d52007-05-09 02:33:46 -0700699 }
David Howells31143d52007-05-09 02:33:46 -0700700 first += count;
David Howells31143d52007-05-09 02:33:46 -0700701 __pagevec_release(&pv);
David Howells5bbf5d32007-05-10 03:15:23 -0700702 } while (first <= last);
David Howells31143d52007-05-09 02:33:46 -0700703
David Howells4343d002017-11-02 15:27:52 +0000704 afs_prune_wb_keys(vnode);
David Howells31143d52007-05-09 02:33:46 -0700705 _leave("");
706}
707
708/*
709 * write to an AFS file
710 */
Al Viro50b55512014-04-03 14:13:46 -0400711ssize_t afs_file_write(struct kiocb *iocb, struct iov_iter *from)
David Howells31143d52007-05-09 02:33:46 -0700712{
Al Viro496ad9a2013-01-23 17:07:38 -0500713 struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp));
David Howells31143d52007-05-09 02:33:46 -0700714 ssize_t result;
Al Viro50b55512014-04-03 14:13:46 -0400715 size_t count = iov_iter_count(from);
David Howells31143d52007-05-09 02:33:46 -0700716
Al Viro50b55512014-04-03 14:13:46 -0400717 _enter("{%x.%u},{%zu},",
718 vnode->fid.vid, vnode->fid.vnode, count);
David Howells31143d52007-05-09 02:33:46 -0700719
720 if (IS_SWAPFILE(&vnode->vfs_inode)) {
721 printk(KERN_INFO
722 "AFS: Attempt to write to active swap file!\n");
723 return -EBUSY;
724 }
725
726 if (!count)
727 return 0;
728
Al Viro50b55512014-04-03 14:13:46 -0400729 result = generic_file_write_iter(iocb, from);
David Howells31143d52007-05-09 02:33:46 -0700730
David Howells31143d52007-05-09 02:33:46 -0700731 _leave(" = %zd", result);
732 return result;
733}
734
735/*
David Howells31143d52007-05-09 02:33:46 -0700736 * flush any dirty pages for this process, and check for write errors.
737 * - the return status from this call provides a reliable indication of
738 * whether any write errors occurred for this process.
739 */
Josef Bacik02c24a82011-07-16 20:44:56 -0400740int afs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
David Howells31143d52007-05-09 02:33:46 -0700741{
Al Viro3c981bf2013-09-03 13:37:45 -0400742 struct inode *inode = file_inode(file);
Al Viro3c981bf2013-09-03 13:37:45 -0400743 struct afs_vnode *vnode = AFS_FS_I(inode);
David Howells31143d52007-05-09 02:33:46 -0700744
Al Viro3c981bf2013-09-03 13:37:45 -0400745 _enter("{%x:%u},{n=%pD},%d",
746 vnode->fid.vid, vnode->fid.vnode, file,
David Howells31143d52007-05-09 02:33:46 -0700747 datasync);
748
David Howells4343d002017-11-02 15:27:52 +0000749 return file_write_and_wait_range(file, start, end);
David Howells31143d52007-05-09 02:33:46 -0700750}
David Howells9b3f26c2009-04-03 16:42:41 +0100751
752/*
753 * notification that a previously read-only page is about to become writable
754 * - if it returns an error, the caller will deliver a bus error signal
755 */
David Howells1cf7a152017-11-02 15:27:52 +0000756int afs_page_mkwrite(struct vm_fault *vmf)
David Howells9b3f26c2009-04-03 16:42:41 +0100757{
David Howells1cf7a152017-11-02 15:27:52 +0000758 struct file *file = vmf->vma->vm_file;
759 struct inode *inode = file_inode(file);
760 struct afs_vnode *vnode = AFS_FS_I(inode);
761 unsigned long priv;
David Howells9b3f26c2009-04-03 16:42:41 +0100762
763 _enter("{{%x:%u}},{%lx}",
David Howells1cf7a152017-11-02 15:27:52 +0000764 vnode->fid.vid, vnode->fid.vnode, vmf->page->index);
David Howells9b3f26c2009-04-03 16:42:41 +0100765
David Howells1cf7a152017-11-02 15:27:52 +0000766 sb_start_pagefault(inode->i_sb);
767
768 /* Wait for the page to be written to the cache before we allow it to
769 * be modified. We then assume the entire page will need writing back.
770 */
David Howells9b3f26c2009-04-03 16:42:41 +0100771#ifdef CONFIG_AFS_FSCACHE
David Howells1cf7a152017-11-02 15:27:52 +0000772 fscache_wait_on_page_write(vnode->cache, vmf->page);
David Howells9b3f26c2009-04-03 16:42:41 +0100773#endif
774
David Howells1cf7a152017-11-02 15:27:52 +0000775 if (PageWriteback(vmf->page) &&
776 wait_on_page_bit_killable(vmf->page, PG_writeback) < 0)
777 return VM_FAULT_RETRY;
778
779 if (lock_page_killable(vmf->page) < 0)
780 return VM_FAULT_RETRY;
781
782 /* We mustn't change page->private until writeback is complete as that
783 * details the portion of the page we need to write back and we might
784 * need to redirty the page if there's a problem.
785 */
786 wait_on_page_writeback(vmf->page);
787
788 priv = (unsigned long)PAGE_SIZE << AFS_PRIV_SHIFT; /* To */
789 priv |= 0; /* From */
David Howells13524ab2017-11-02 15:27:53 +0000790 trace_afs_page_dirty(vnode, tracepoint_string("mkwrite"),
791 vmf->page->index, priv);
David Howells1cf7a152017-11-02 15:27:52 +0000792 SetPagePrivate(vmf->page);
793 set_page_private(vmf->page, priv);
794
795 sb_end_pagefault(inode->i_sb);
796 return VM_FAULT_LOCKED;
David Howells9b3f26c2009-04-03 16:42:41 +0100797}
David Howells4343d002017-11-02 15:27:52 +0000798
799/*
800 * Prune the keys cached for writeback. The caller must hold vnode->wb_lock.
801 */
802void afs_prune_wb_keys(struct afs_vnode *vnode)
803{
804 LIST_HEAD(graveyard);
805 struct afs_wb_key *wbk, *tmp;
806
807 /* Discard unused keys */
808 spin_lock(&vnode->wb_lock);
809
810 if (!mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_WRITEBACK) &&
811 !mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_DIRTY)) {
812 list_for_each_entry_safe(wbk, tmp, &vnode->wb_keys, vnode_link) {
813 if (refcount_read(&wbk->usage) == 1)
814 list_move(&wbk->vnode_link, &graveyard);
815 }
816 }
817
818 spin_unlock(&vnode->wb_lock);
819
820 while (!list_empty(&graveyard)) {
821 wbk = list_entry(graveyard.next, struct afs_wb_key, vnode_link);
822 list_del(&wbk->vnode_link);
823 afs_put_wb_key(wbk);
824 }
825}
826
827/*
828 * Clean up a page during invalidation.
829 */
830int afs_launder_page(struct page *page)
831{
832 struct address_space *mapping = page->mapping;
833 struct afs_vnode *vnode = AFS_FS_I(mapping->host);
834 unsigned long priv;
835 unsigned int f, t;
836 int ret = 0;
837
838 _enter("{%lx}", page->index);
839
840 priv = page_private(page);
841 if (clear_page_dirty_for_io(page)) {
842 f = 0;
843 t = PAGE_SIZE;
844 if (PagePrivate(page)) {
845 f = priv & AFS_PRIV_MAX;
846 t = priv >> AFS_PRIV_SHIFT;
847 }
848
David Howells13524ab2017-11-02 15:27:53 +0000849 trace_afs_page_dirty(vnode, tracepoint_string("launder"),
850 page->index, priv);
David Howells4343d002017-11-02 15:27:52 +0000851 ret = afs_store_data(mapping, page->index, page->index, t, f);
852 }
853
David Howells13524ab2017-11-02 15:27:53 +0000854 trace_afs_page_dirty(vnode, tracepoint_string("laundered"),
855 page->index, priv);
David Howells4343d002017-11-02 15:27:52 +0000856 set_page_private(page, 0);
857 ClearPagePrivate(page);
858
859#ifdef CONFIG_AFS_FSCACHE
860 if (PageFsCache(page)) {
861 fscache_wait_on_page_write(vnode->cache, page);
862 fscache_uncache_page(vnode->cache, page);
863 }
864#endif
865 return ret;
David Howells31143d52007-05-09 02:33:46 -0700866}