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c38f4e96 DH |
1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* Network filesystem high-level write support. | |
3 | * | |
4 | * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved. | |
5 | * Written by David Howells (dhowells@redhat.com) | |
6 | */ | |
7 | ||
8 | #include <linux/export.h> | |
9 | #include <linux/fs.h> | |
10 | #include <linux/mm.h> | |
11 | #include <linux/pagemap.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/pagevec.h> | |
14 | #include "internal.h" | |
15 | ||
16 | /* | |
17 | * Determined write method. Adjust netfs_folio_traces if this is changed. | |
18 | */ | |
19 | enum netfs_how_to_modify { | |
20 | NETFS_FOLIO_IS_UPTODATE, /* Folio is uptodate already */ | |
21 | NETFS_JUST_PREFETCH, /* We have to read the folio anyway */ | |
22 | NETFS_WHOLE_FOLIO_MODIFY, /* We're going to overwrite the whole folio */ | |
23 | NETFS_MODIFY_AND_CLEAR, /* We can assume there is no data to be downloaded. */ | |
24 | NETFS_STREAMING_WRITE, /* Store incomplete data in non-uptodate page. */ | |
25 | NETFS_STREAMING_WRITE_CONT, /* Continue streaming write. */ | |
26 | NETFS_FLUSH_CONTENT, /* Flush incompatible content. */ | |
27 | }; | |
28 | ||
41d8e767 DH |
29 | static void netfs_cleanup_buffered_write(struct netfs_io_request *wreq); |
30 | ||
c38f4e96 DH |
31 | static void netfs_set_group(struct folio *folio, struct netfs_group *netfs_group) |
32 | { | |
33 | if (netfs_group && !folio_get_private(folio)) | |
34 | folio_attach_private(folio, netfs_get_group(netfs_group)); | |
35 | } | |
36 | ||
62c3b748 DH |
37 | #if IS_ENABLED(CONFIG_FSCACHE) |
38 | static void netfs_folio_start_fscache(bool caching, struct folio *folio) | |
39 | { | |
40 | if (caching) | |
41 | folio_start_fscache(folio); | |
42 | } | |
43 | #else | |
44 | static void netfs_folio_start_fscache(bool caching, struct folio *folio) | |
45 | { | |
46 | } | |
47 | #endif | |
48 | ||
c38f4e96 DH |
49 | /* |
50 | * Decide how we should modify a folio. We might be attempting to do | |
51 | * write-streaming, in which case we don't want to a local RMW cycle if we can | |
52 | * avoid it. If we're doing local caching or content crypto, we award that | |
53 | * priority over avoiding RMW. If the file is open readably, then we also | |
54 | * assume that we may want to read what we wrote. | |
55 | */ | |
56 | static enum netfs_how_to_modify netfs_how_to_modify(struct netfs_inode *ctx, | |
57 | struct file *file, | |
58 | struct folio *folio, | |
59 | void *netfs_group, | |
60 | size_t flen, | |
61 | size_t offset, | |
62 | size_t len, | |
63 | bool maybe_trouble) | |
64 | { | |
65 | struct netfs_folio *finfo = netfs_folio_info(folio); | |
66 | loff_t pos = folio_file_pos(folio); | |
67 | ||
68 | _enter(""); | |
69 | ||
70 | if (netfs_folio_group(folio) != netfs_group) | |
71 | return NETFS_FLUSH_CONTENT; | |
72 | ||
73 | if (folio_test_uptodate(folio)) | |
74 | return NETFS_FOLIO_IS_UPTODATE; | |
75 | ||
100ccd18 | 76 | if (pos >= ctx->zero_point) |
c38f4e96 DH |
77 | return NETFS_MODIFY_AND_CLEAR; |
78 | ||
79 | if (!maybe_trouble && offset == 0 && len >= flen) | |
80 | return NETFS_WHOLE_FOLIO_MODIFY; | |
81 | ||
82 | if (file->f_mode & FMODE_READ) | |
92a714d7 DH |
83 | goto no_write_streaming; |
84 | if (test_bit(NETFS_ICTX_NO_WRITE_STREAMING, &ctx->flags)) | |
85 | goto no_write_streaming; | |
86 | ||
87 | if (netfs_is_cache_enabled(ctx)) { | |
88 | /* We don't want to get a streaming write on a file that loses | |
89 | * caching service temporarily because the backing store got | |
90 | * culled. | |
91 | */ | |
92 | if (!test_bit(NETFS_ICTX_NO_WRITE_STREAMING, &ctx->flags)) | |
93 | set_bit(NETFS_ICTX_NO_WRITE_STREAMING, &ctx->flags); | |
94 | goto no_write_streaming; | |
95 | } | |
c38f4e96 DH |
96 | |
97 | if (!finfo) | |
98 | return NETFS_STREAMING_WRITE; | |
99 | ||
100 | /* We can continue a streaming write only if it continues on from the | |
101 | * previous. If it overlaps, we must flush lest we suffer a partial | |
102 | * copy and disjoint dirty regions. | |
103 | */ | |
104 | if (offset == finfo->dirty_offset + finfo->dirty_len) | |
105 | return NETFS_STREAMING_WRITE_CONT; | |
106 | return NETFS_FLUSH_CONTENT; | |
92a714d7 DH |
107 | |
108 | no_write_streaming: | |
109 | if (finfo) { | |
110 | netfs_stat(&netfs_n_wh_wstream_conflict); | |
111 | return NETFS_FLUSH_CONTENT; | |
112 | } | |
113 | return NETFS_JUST_PREFETCH; | |
c38f4e96 DH |
114 | } |
115 | ||
116 | /* | |
e2e2e839 DH |
117 | * Grab a folio for writing and lock it. Attempt to allocate as large a folio |
118 | * as possible to hold as much of the remaining length as possible in one go. | |
c38f4e96 DH |
119 | */ |
120 | static struct folio *netfs_grab_folio_for_write(struct address_space *mapping, | |
121 | loff_t pos, size_t part) | |
122 | { | |
123 | pgoff_t index = pos / PAGE_SIZE; | |
e2e2e839 | 124 | fgf_t fgp_flags = FGP_WRITEBEGIN; |
c38f4e96 | 125 | |
e2e2e839 DH |
126 | if (mapping_large_folio_support(mapping)) |
127 | fgp_flags |= fgf_set_order(pos % PAGE_SIZE + part); | |
128 | ||
129 | return __filemap_get_folio(mapping, index, fgp_flags, | |
c38f4e96 DH |
130 | mapping_gfp_mask(mapping)); |
131 | } | |
132 | ||
133 | /** | |
134 | * netfs_perform_write - Copy data into the pagecache. | |
135 | * @iocb: The operation parameters | |
136 | * @iter: The source buffer | |
137 | * @netfs_group: Grouping for dirty pages (eg. ceph snaps). | |
138 | * | |
139 | * Copy data into pagecache pages attached to the inode specified by @iocb. | |
140 | * The caller must hold appropriate inode locks. | |
141 | * | |
142 | * Dirty pages are tagged with a netfs_folio struct if they're not up to date | |
143 | * to indicate the range modified. Dirty pages may also be tagged with a | |
144 | * netfs-specific grouping such that data from an old group gets flushed before | |
145 | * a new one is started. | |
146 | */ | |
147 | ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter, | |
148 | struct netfs_group *netfs_group) | |
149 | { | |
150 | struct file *file = iocb->ki_filp; | |
151 | struct inode *inode = file_inode(file); | |
152 | struct address_space *mapping = inode->i_mapping; | |
153 | struct netfs_inode *ctx = netfs_inode(inode); | |
41d8e767 DH |
154 | struct writeback_control wbc = { |
155 | .sync_mode = WB_SYNC_NONE, | |
156 | .for_sync = true, | |
157 | .nr_to_write = LONG_MAX, | |
158 | .range_start = iocb->ki_pos, | |
159 | .range_end = iocb->ki_pos + iter->count, | |
160 | }; | |
161 | struct netfs_io_request *wreq = NULL; | |
c38f4e96 DH |
162 | struct netfs_folio *finfo; |
163 | struct folio *folio; | |
164 | enum netfs_how_to_modify howto; | |
165 | enum netfs_folio_trace trace; | |
166 | unsigned int bdp_flags = (iocb->ki_flags & IOCB_SYNC) ? 0: BDP_ASYNC; | |
619606a7 | 167 | ssize_t written = 0, ret, ret2; |
c38f4e96 DH |
168 | loff_t i_size, pos = iocb->ki_pos, from, to; |
169 | size_t max_chunk = PAGE_SIZE << MAX_PAGECACHE_ORDER; | |
170 | bool maybe_trouble = false; | |
171 | ||
41d8e767 DH |
172 | if (unlikely(test_bit(NETFS_ICTX_WRITETHROUGH, &ctx->flags) || |
173 | iocb->ki_flags & (IOCB_DSYNC | IOCB_SYNC)) | |
174 | ) { | |
41d8e767 DH |
175 | wbc_attach_fdatawrite_inode(&wbc, mapping->host); |
176 | ||
c97f59e2 DH |
177 | ret = filemap_write_and_wait_range(mapping, pos, pos + iter->count); |
178 | if (ret < 0) { | |
179 | wbc_detach_inode(&wbc); | |
180 | goto out; | |
181 | } | |
182 | ||
41d8e767 DH |
183 | wreq = netfs_begin_writethrough(iocb, iter->count); |
184 | if (IS_ERR(wreq)) { | |
185 | wbc_detach_inode(&wbc); | |
186 | ret = PTR_ERR(wreq); | |
187 | wreq = NULL; | |
188 | goto out; | |
189 | } | |
190 | if (!is_sync_kiocb(iocb)) | |
191 | wreq->iocb = iocb; | |
192 | wreq->cleanup = netfs_cleanup_buffered_write; | |
193 | } | |
194 | ||
c38f4e96 DH |
195 | do { |
196 | size_t flen; | |
197 | size_t offset; /* Offset into pagecache folio */ | |
198 | size_t part; /* Bytes to write to folio */ | |
199 | size_t copied; /* Bytes copied from user */ | |
200 | ||
201 | ret = balance_dirty_pages_ratelimited_flags(mapping, bdp_flags); | |
202 | if (unlikely(ret < 0)) | |
203 | break; | |
204 | ||
205 | offset = pos & (max_chunk - 1); | |
206 | part = min(max_chunk - offset, iov_iter_count(iter)); | |
207 | ||
208 | /* Bring in the user pages that we will copy from _first_ lest | |
209 | * we hit a nasty deadlock on copying from the same page as | |
210 | * we're writing to, without it being marked uptodate. | |
211 | * | |
212 | * Not only is this an optimisation, but it is also required to | |
213 | * check that the address is actually valid, when atomic | |
214 | * usercopies are used below. | |
215 | * | |
216 | * We rely on the page being held onto long enough by the LRU | |
217 | * that we can grab it below if this causes it to be read. | |
218 | */ | |
219 | ret = -EFAULT; | |
220 | if (unlikely(fault_in_iov_iter_readable(iter, part) == part)) | |
221 | break; | |
222 | ||
c38f4e96 | 223 | folio = netfs_grab_folio_for_write(mapping, pos, part); |
843609df DC |
224 | if (IS_ERR(folio)) { |
225 | ret = PTR_ERR(folio); | |
c38f4e96 | 226 | break; |
843609df | 227 | } |
c38f4e96 DH |
228 | |
229 | flen = folio_size(folio); | |
230 | offset = pos & (flen - 1); | |
231 | part = min_t(size_t, flen - offset, part); | |
232 | ||
233 | if (signal_pending(current)) { | |
234 | ret = written ? -EINTR : -ERESTARTSYS; | |
235 | goto error_folio_unlock; | |
236 | } | |
237 | ||
238 | /* See if we need to prefetch the area we're going to modify. | |
239 | * We need to do this before we get a lock on the folio in case | |
240 | * there's more than one writer competing for the same cache | |
241 | * block. | |
242 | */ | |
243 | howto = netfs_how_to_modify(ctx, file, folio, netfs_group, | |
244 | flen, offset, part, maybe_trouble); | |
245 | _debug("howto %u", howto); | |
246 | switch (howto) { | |
247 | case NETFS_JUST_PREFETCH: | |
248 | ret = netfs_prefetch_for_write(file, folio, offset, part); | |
249 | if (ret < 0) { | |
250 | _debug("prefetch = %zd", ret); | |
251 | goto error_folio_unlock; | |
252 | } | |
253 | break; | |
254 | case NETFS_FOLIO_IS_UPTODATE: | |
255 | case NETFS_WHOLE_FOLIO_MODIFY: | |
256 | case NETFS_STREAMING_WRITE_CONT: | |
257 | break; | |
258 | case NETFS_MODIFY_AND_CLEAR: | |
259 | zero_user_segment(&folio->page, 0, offset); | |
260 | break; | |
261 | case NETFS_STREAMING_WRITE: | |
262 | ret = -EIO; | |
263 | if (WARN_ON(folio_get_private(folio))) | |
264 | goto error_folio_unlock; | |
265 | break; | |
266 | case NETFS_FLUSH_CONTENT: | |
267 | trace_netfs_folio(folio, netfs_flush_content); | |
268 | from = folio_pos(folio); | |
269 | to = from + folio_size(folio) - 1; | |
270 | folio_unlock(folio); | |
271 | folio_put(folio); | |
272 | ret = filemap_write_and_wait_range(mapping, from, to); | |
273 | if (ret < 0) | |
274 | goto error_folio_unlock; | |
275 | continue; | |
276 | } | |
277 | ||
278 | if (mapping_writably_mapped(mapping)) | |
279 | flush_dcache_folio(folio); | |
280 | ||
281 | copied = copy_folio_from_iter_atomic(folio, offset, part, iter); | |
282 | ||
283 | flush_dcache_folio(folio); | |
284 | ||
285 | /* Deal with a (partially) failed copy */ | |
286 | if (copied == 0) { | |
287 | ret = -EFAULT; | |
288 | goto error_folio_unlock; | |
289 | } | |
290 | ||
291 | trace = (enum netfs_folio_trace)howto; | |
292 | switch (howto) { | |
293 | case NETFS_FOLIO_IS_UPTODATE: | |
294 | case NETFS_JUST_PREFETCH: | |
295 | netfs_set_group(folio, netfs_group); | |
296 | break; | |
297 | case NETFS_MODIFY_AND_CLEAR: | |
298 | zero_user_segment(&folio->page, offset + copied, flen); | |
299 | netfs_set_group(folio, netfs_group); | |
300 | folio_mark_uptodate(folio); | |
301 | break; | |
302 | case NETFS_WHOLE_FOLIO_MODIFY: | |
303 | if (unlikely(copied < part)) { | |
304 | maybe_trouble = true; | |
305 | iov_iter_revert(iter, copied); | |
306 | copied = 0; | |
307 | goto retry; | |
308 | } | |
309 | netfs_set_group(folio, netfs_group); | |
310 | folio_mark_uptodate(folio); | |
311 | break; | |
312 | case NETFS_STREAMING_WRITE: | |
313 | if (offset == 0 && copied == flen) { | |
314 | netfs_set_group(folio, netfs_group); | |
315 | folio_mark_uptodate(folio); | |
316 | trace = netfs_streaming_filled_page; | |
317 | break; | |
318 | } | |
319 | finfo = kzalloc(sizeof(*finfo), GFP_KERNEL); | |
320 | if (!finfo) { | |
321 | iov_iter_revert(iter, copied); | |
322 | ret = -ENOMEM; | |
323 | goto error_folio_unlock; | |
324 | } | |
325 | finfo->netfs_group = netfs_get_group(netfs_group); | |
326 | finfo->dirty_offset = offset; | |
327 | finfo->dirty_len = copied; | |
328 | folio_attach_private(folio, (void *)((unsigned long)finfo | | |
329 | NETFS_FOLIO_INFO)); | |
330 | break; | |
331 | case NETFS_STREAMING_WRITE_CONT: | |
332 | finfo = netfs_folio_info(folio); | |
333 | finfo->dirty_len += copied; | |
334 | if (finfo->dirty_offset == 0 && finfo->dirty_len == flen) { | |
335 | if (finfo->netfs_group) | |
336 | folio_change_private(folio, finfo->netfs_group); | |
337 | else | |
338 | folio_detach_private(folio); | |
339 | folio_mark_uptodate(folio); | |
340 | kfree(finfo); | |
341 | trace = netfs_streaming_cont_filled_page; | |
342 | } | |
343 | break; | |
344 | default: | |
345 | WARN(true, "Unexpected modify type %u ix=%lx\n", | |
202bc57b | 346 | howto, folio->index); |
c38f4e96 DH |
347 | ret = -EIO; |
348 | goto error_folio_unlock; | |
349 | } | |
350 | ||
351 | trace_netfs_folio(folio, trace); | |
352 | ||
353 | /* Update the inode size if we moved the EOF marker */ | |
354 | i_size = i_size_read(inode); | |
355 | pos += copied; | |
356 | if (pos > i_size) { | |
357 | if (ctx->ops->update_i_size) { | |
358 | ctx->ops->update_i_size(inode, pos); | |
359 | } else { | |
360 | i_size_write(inode, pos); | |
361 | #if IS_ENABLED(CONFIG_FSCACHE) | |
362 | fscache_update_cookie(ctx->cache, NULL, &pos); | |
363 | #endif | |
364 | } | |
365 | } | |
366 | written += copied; | |
367 | ||
41d8e767 DH |
368 | if (likely(!wreq)) { |
369 | folio_mark_dirty(folio); | |
370 | } else { | |
371 | if (folio_test_dirty(folio)) | |
372 | /* Sigh. mmap. */ | |
373 | folio_clear_dirty_for_io(folio); | |
374 | /* We make multiple writes to the folio... */ | |
375 | if (!folio_test_writeback(folio)) { | |
376 | folio_wait_fscache(folio); | |
377 | folio_start_writeback(folio); | |
378 | folio_start_fscache(folio); | |
379 | if (wreq->iter.count == 0) | |
380 | trace_netfs_folio(folio, netfs_folio_trace_wthru); | |
381 | else | |
382 | trace_netfs_folio(folio, netfs_folio_trace_wthru_plus); | |
383 | } | |
384 | netfs_advance_writethrough(wreq, copied, | |
385 | offset + copied == flen); | |
386 | } | |
c38f4e96 DH |
387 | retry: |
388 | folio_unlock(folio); | |
389 | folio_put(folio); | |
390 | folio = NULL; | |
391 | ||
392 | cond_resched(); | |
393 | } while (iov_iter_count(iter)); | |
394 | ||
395 | out: | |
41d8e767 | 396 | if (unlikely(wreq)) { |
619606a7 | 397 | ret2 = netfs_end_writethrough(wreq, iocb); |
41d8e767 | 398 | wbc_detach_inode(&wbc); |
619606a7 DH |
399 | if (ret2 == -EIOCBQUEUED) |
400 | return ret2; | |
401 | if (ret == 0) | |
402 | ret = ret2; | |
c38f4e96 DH |
403 | } |
404 | ||
41d8e767 | 405 | iocb->ki_pos += written; |
c38f4e96 DH |
406 | _leave(" = %zd [%zd]", written, ret); |
407 | return written ? written : ret; | |
408 | ||
409 | error_folio_unlock: | |
410 | folio_unlock(folio); | |
411 | folio_put(folio); | |
412 | goto out; | |
413 | } | |
414 | EXPORT_SYMBOL(netfs_perform_write); | |
938e13a7 DH |
415 | |
416 | /** | |
417 | * netfs_buffered_write_iter_locked - write data to a file | |
418 | * @iocb: IO state structure (file, offset, etc.) | |
419 | * @from: iov_iter with data to write | |
420 | * @netfs_group: Grouping for dirty pages (eg. ceph snaps). | |
421 | * | |
422 | * This function does all the work needed for actually writing data to a | |
423 | * file. It does all basic checks, removes SUID from the file, updates | |
424 | * modification times and calls proper subroutines depending on whether we | |
425 | * do direct IO or a standard buffered write. | |
426 | * | |
427 | * The caller must hold appropriate locks around this function and have called | |
428 | * generic_write_checks() already. The caller is also responsible for doing | |
429 | * any necessary syncing afterwards. | |
430 | * | |
431 | * This function does *not* take care of syncing data in case of O_SYNC write. | |
432 | * A caller has to handle it. This is mainly due to the fact that we want to | |
433 | * avoid syncing under i_rwsem. | |
434 | * | |
435 | * Return: | |
436 | * * number of bytes written, even for truncated writes | |
437 | * * negative error code if no data has been written at all | |
438 | */ | |
439 | ssize_t netfs_buffered_write_iter_locked(struct kiocb *iocb, struct iov_iter *from, | |
440 | struct netfs_group *netfs_group) | |
441 | { | |
442 | struct file *file = iocb->ki_filp; | |
443 | ssize_t ret; | |
444 | ||
445 | trace_netfs_write_iter(iocb, from); | |
446 | ||
447 | ret = file_remove_privs(file); | |
448 | if (ret) | |
449 | return ret; | |
450 | ||
451 | ret = file_update_time(file); | |
452 | if (ret) | |
453 | return ret; | |
454 | ||
455 | return netfs_perform_write(iocb, from, netfs_group); | |
456 | } | |
457 | EXPORT_SYMBOL(netfs_buffered_write_iter_locked); | |
458 | ||
459 | /** | |
460 | * netfs_file_write_iter - write data to a file | |
461 | * @iocb: IO state structure | |
462 | * @from: iov_iter with data to write | |
463 | * | |
464 | * Perform a write to a file, writing into the pagecache if possible and doing | |
465 | * an unbuffered write instead if not. | |
466 | * | |
467 | * Return: | |
468 | * * Negative error code if no data has been written at all of | |
469 | * vfs_fsync_range() failed for a synchronous write | |
470 | * * Number of bytes written, even for truncated writes | |
471 | */ | |
472 | ssize_t netfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) | |
473 | { | |
474 | struct file *file = iocb->ki_filp; | |
475 | struct inode *inode = file->f_mapping->host; | |
476 | struct netfs_inode *ictx = netfs_inode(inode); | |
477 | ssize_t ret; | |
478 | ||
479 | _enter("%llx,%zx,%llx", iocb->ki_pos, iov_iter_count(from), i_size_read(inode)); | |
480 | ||
ca9ca1a5 DH |
481 | if (!iov_iter_count(from)) |
482 | return 0; | |
483 | ||
938e13a7 DH |
484 | if ((iocb->ki_flags & IOCB_DIRECT) || |
485 | test_bit(NETFS_ICTX_UNBUFFERED, &ictx->flags)) | |
486 | return netfs_unbuffered_write_iter(iocb, from); | |
487 | ||
488 | ret = netfs_start_io_write(inode); | |
489 | if (ret < 0) | |
490 | return ret; | |
491 | ||
492 | ret = generic_write_checks(iocb, from); | |
493 | if (ret > 0) | |
494 | ret = netfs_buffered_write_iter_locked(iocb, from, NULL); | |
495 | netfs_end_io_write(inode); | |
496 | if (ret > 0) | |
497 | ret = generic_write_sync(iocb, ret); | |
498 | return ret; | |
499 | } | |
500 | EXPORT_SYMBOL(netfs_file_write_iter); | |
102a7e2c DH |
501 | |
502 | /* | |
503 | * Notification that a previously read-only page is about to become writable. | |
504 | * Note that the caller indicates a single page of a multipage folio. | |
505 | */ | |
506 | vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_group) | |
507 | { | |
508 | struct folio *folio = page_folio(vmf->page); | |
509 | struct file *file = vmf->vma->vm_file; | |
510 | struct inode *inode = file_inode(file); | |
511 | vm_fault_t ret = VM_FAULT_RETRY; | |
512 | int err; | |
513 | ||
514 | _enter("%lx", folio->index); | |
515 | ||
516 | sb_start_pagefault(inode->i_sb); | |
517 | ||
518 | if (folio_wait_writeback_killable(folio)) | |
519 | goto out; | |
520 | ||
521 | if (folio_lock_killable(folio) < 0) | |
522 | goto out; | |
523 | ||
524 | /* Can we see a streaming write here? */ | |
525 | if (WARN_ON(!folio_test_uptodate(folio))) { | |
526 | ret = VM_FAULT_SIGBUS | VM_FAULT_LOCKED; | |
527 | goto out; | |
528 | } | |
529 | ||
530 | if (netfs_folio_group(folio) != netfs_group) { | |
531 | folio_unlock(folio); | |
532 | err = filemap_fdatawait_range(inode->i_mapping, | |
533 | folio_pos(folio), | |
534 | folio_pos(folio) + folio_size(folio)); | |
535 | switch (err) { | |
536 | case 0: | |
537 | ret = VM_FAULT_RETRY; | |
538 | goto out; | |
539 | case -ENOMEM: | |
540 | ret = VM_FAULT_OOM; | |
541 | goto out; | |
542 | default: | |
543 | ret = VM_FAULT_SIGBUS; | |
544 | goto out; | |
545 | } | |
546 | } | |
547 | ||
548 | if (folio_test_dirty(folio)) | |
549 | trace_netfs_folio(folio, netfs_folio_trace_mkwrite_plus); | |
550 | else | |
551 | trace_netfs_folio(folio, netfs_folio_trace_mkwrite); | |
552 | netfs_set_group(folio, netfs_group); | |
553 | file_update_time(file); | |
554 | ret = VM_FAULT_LOCKED; | |
555 | out: | |
556 | sb_end_pagefault(inode->i_sb); | |
557 | return ret; | |
558 | } | |
559 | EXPORT_SYMBOL(netfs_page_mkwrite); | |
62c3b748 DH |
560 | |
561 | /* | |
562 | * Kill all the pages in the given range | |
563 | */ | |
564 | static void netfs_kill_pages(struct address_space *mapping, | |
565 | loff_t start, loff_t len) | |
566 | { | |
567 | struct folio *folio; | |
568 | pgoff_t index = start / PAGE_SIZE; | |
569 | pgoff_t last = (start + len - 1) / PAGE_SIZE, next; | |
570 | ||
571 | _enter("%llx-%llx", start, start + len - 1); | |
572 | ||
573 | do { | |
574 | _debug("kill %lx (to %lx)", index, last); | |
575 | ||
576 | folio = filemap_get_folio(mapping, index); | |
577 | if (IS_ERR(folio)) { | |
578 | next = index + 1; | |
579 | continue; | |
580 | } | |
581 | ||
582 | next = folio_next_index(folio); | |
583 | ||
584 | trace_netfs_folio(folio, netfs_folio_trace_kill); | |
585 | folio_clear_uptodate(folio); | |
586 | if (folio_test_fscache(folio)) | |
587 | folio_end_fscache(folio); | |
588 | folio_end_writeback(folio); | |
589 | folio_lock(folio); | |
16df6e07 | 590 | generic_error_remove_folio(mapping, folio); |
62c3b748 DH |
591 | folio_unlock(folio); |
592 | folio_put(folio); | |
593 | ||
594 | } while (index = next, index <= last); | |
595 | ||
596 | _leave(""); | |
597 | } | |
598 | ||
599 | /* | |
600 | * Redirty all the pages in a given range. | |
601 | */ | |
602 | static void netfs_redirty_pages(struct address_space *mapping, | |
603 | loff_t start, loff_t len) | |
604 | { | |
605 | struct folio *folio; | |
606 | pgoff_t index = start / PAGE_SIZE; | |
607 | pgoff_t last = (start + len - 1) / PAGE_SIZE, next; | |
608 | ||
609 | _enter("%llx-%llx", start, start + len - 1); | |
610 | ||
611 | do { | |
612 | _debug("redirty %llx @%llx", len, start); | |
613 | ||
614 | folio = filemap_get_folio(mapping, index); | |
615 | if (IS_ERR(folio)) { | |
616 | next = index + 1; | |
617 | continue; | |
618 | } | |
619 | ||
620 | next = folio_next_index(folio); | |
621 | trace_netfs_folio(folio, netfs_folio_trace_redirty); | |
622 | filemap_dirty_folio(mapping, folio); | |
623 | if (folio_test_fscache(folio)) | |
624 | folio_end_fscache(folio); | |
625 | folio_end_writeback(folio); | |
626 | folio_put(folio); | |
627 | } while (index = next, index <= last); | |
628 | ||
629 | balance_dirty_pages_ratelimited(mapping); | |
630 | ||
631 | _leave(""); | |
632 | } | |
633 | ||
634 | /* | |
635 | * Completion of write to server | |
636 | */ | |
637 | static void netfs_pages_written_back(struct netfs_io_request *wreq) | |
638 | { | |
639 | struct address_space *mapping = wreq->mapping; | |
640 | struct netfs_folio *finfo; | |
641 | struct netfs_group *group = NULL; | |
642 | struct folio *folio; | |
643 | pgoff_t last; | |
644 | int gcount = 0; | |
645 | ||
646 | XA_STATE(xas, &mapping->i_pages, wreq->start / PAGE_SIZE); | |
647 | ||
648 | _enter("%llx-%llx", wreq->start, wreq->start + wreq->len); | |
649 | ||
650 | rcu_read_lock(); | |
651 | ||
652 | last = (wreq->start + wreq->len - 1) / PAGE_SIZE; | |
653 | xas_for_each(&xas, folio, last) { | |
654 | WARN(!folio_test_writeback(folio), | |
655 | "bad %zx @%llx page %lx %lx\n", | |
202bc57b | 656 | wreq->len, wreq->start, folio->index, last); |
62c3b748 DH |
657 | |
658 | if ((finfo = netfs_folio_info(folio))) { | |
659 | /* Streaming writes cannot be redirtied whilst under | |
660 | * writeback, so discard the streaming record. | |
661 | */ | |
662 | folio_detach_private(folio); | |
663 | group = finfo->netfs_group; | |
664 | gcount++; | |
665 | trace_netfs_folio(folio, netfs_folio_trace_clear_s); | |
666 | kfree(finfo); | |
667 | } else if ((group = netfs_folio_group(folio))) { | |
668 | /* Need to detach the group pointer if the page didn't | |
669 | * get redirtied. If it has been redirtied, then it | |
670 | * must be within the same group. | |
671 | */ | |
672 | if (folio_test_dirty(folio)) { | |
673 | trace_netfs_folio(folio, netfs_folio_trace_redirtied); | |
674 | goto end_wb; | |
675 | } | |
676 | if (folio_trylock(folio)) { | |
677 | if (!folio_test_dirty(folio)) { | |
678 | folio_detach_private(folio); | |
679 | gcount++; | |
680 | trace_netfs_folio(folio, netfs_folio_trace_clear_g); | |
681 | } else { | |
682 | trace_netfs_folio(folio, netfs_folio_trace_redirtied); | |
683 | } | |
684 | folio_unlock(folio); | |
685 | goto end_wb; | |
686 | } | |
687 | ||
688 | xas_pause(&xas); | |
689 | rcu_read_unlock(); | |
690 | folio_lock(folio); | |
691 | if (!folio_test_dirty(folio)) { | |
692 | folio_detach_private(folio); | |
693 | gcount++; | |
694 | trace_netfs_folio(folio, netfs_folio_trace_clear_g); | |
695 | } else { | |
696 | trace_netfs_folio(folio, netfs_folio_trace_redirtied); | |
697 | } | |
698 | folio_unlock(folio); | |
699 | rcu_read_lock(); | |
700 | } else { | |
701 | trace_netfs_folio(folio, netfs_folio_trace_clear); | |
702 | } | |
703 | end_wb: | |
704 | if (folio_test_fscache(folio)) | |
705 | folio_end_fscache(folio); | |
807c6d09 | 706 | xas_advance(&xas, folio_next_index(folio) - 1); |
62c3b748 DH |
707 | folio_end_writeback(folio); |
708 | } | |
709 | ||
710 | rcu_read_unlock(); | |
711 | netfs_put_group_many(group, gcount); | |
712 | _leave(""); | |
713 | } | |
714 | ||
715 | /* | |
716 | * Deal with the disposition of the folios that are under writeback to close | |
717 | * out the operation. | |
718 | */ | |
719 | static void netfs_cleanup_buffered_write(struct netfs_io_request *wreq) | |
720 | { | |
721 | struct address_space *mapping = wreq->mapping; | |
722 | ||
723 | _enter(""); | |
724 | ||
725 | switch (wreq->error) { | |
726 | case 0: | |
727 | netfs_pages_written_back(wreq); | |
728 | break; | |
729 | ||
730 | default: | |
731 | pr_notice("R=%08x Unexpected error %d\n", wreq->debug_id, wreq->error); | |
732 | fallthrough; | |
733 | case -EACCES: | |
734 | case -EPERM: | |
735 | case -ENOKEY: | |
736 | case -EKEYEXPIRED: | |
737 | case -EKEYREJECTED: | |
738 | case -EKEYREVOKED: | |
739 | case -ENETRESET: | |
740 | case -EDQUOT: | |
741 | case -ENOSPC: | |
742 | netfs_redirty_pages(mapping, wreq->start, wreq->len); | |
743 | break; | |
744 | ||
745 | case -EROFS: | |
746 | case -EIO: | |
747 | case -EREMOTEIO: | |
748 | case -EFBIG: | |
749 | case -ENOENT: | |
750 | case -ENOMEDIUM: | |
751 | case -ENXIO: | |
752 | netfs_kill_pages(mapping, wreq->start, wreq->len); | |
753 | break; | |
754 | } | |
755 | ||
756 | if (wreq->error) | |
757 | mapping_set_error(mapping, wreq->error); | |
758 | if (wreq->netfs_ops->done) | |
759 | wreq->netfs_ops->done(wreq); | |
760 | } | |
761 | ||
762 | /* | |
763 | * Extend the region to be written back to include subsequent contiguously | |
764 | * dirty pages if possible, but don't sleep while doing so. | |
765 | * | |
766 | * If this page holds new content, then we can include filler zeros in the | |
767 | * writeback. | |
768 | */ | |
769 | static void netfs_extend_writeback(struct address_space *mapping, | |
770 | struct netfs_group *group, | |
771 | struct xa_state *xas, | |
772 | long *_count, | |
773 | loff_t start, | |
774 | loff_t max_len, | |
775 | bool caching, | |
776 | size_t *_len, | |
777 | size_t *_top) | |
778 | { | |
779 | struct netfs_folio *finfo; | |
780 | struct folio_batch fbatch; | |
781 | struct folio *folio; | |
782 | unsigned int i; | |
783 | pgoff_t index = (start + *_len) / PAGE_SIZE; | |
784 | size_t len; | |
785 | void *priv; | |
786 | bool stop = true; | |
787 | ||
788 | folio_batch_init(&fbatch); | |
789 | ||
790 | do { | |
791 | /* Firstly, we gather up a batch of contiguous dirty pages | |
792 | * under the RCU read lock - but we can't clear the dirty flags | |
793 | * there if any of those pages are mapped. | |
794 | */ | |
795 | rcu_read_lock(); | |
796 | ||
797 | xas_for_each(xas, folio, ULONG_MAX) { | |
798 | stop = true; | |
799 | if (xas_retry(xas, folio)) | |
800 | continue; | |
801 | if (xa_is_value(folio)) | |
802 | break; | |
202bc57b | 803 | if (folio->index != index) { |
62c3b748 DH |
804 | xas_reset(xas); |
805 | break; | |
806 | } | |
807 | ||
808 | if (!folio_try_get_rcu(folio)) { | |
809 | xas_reset(xas); | |
810 | continue; | |
811 | } | |
812 | ||
813 | /* Has the folio moved or been split? */ | |
814 | if (unlikely(folio != xas_reload(xas))) { | |
815 | folio_put(folio); | |
816 | xas_reset(xas); | |
817 | break; | |
818 | } | |
819 | ||
820 | if (!folio_trylock(folio)) { | |
821 | folio_put(folio); | |
822 | xas_reset(xas); | |
823 | break; | |
824 | } | |
825 | if (!folio_test_dirty(folio) || | |
826 | folio_test_writeback(folio) || | |
827 | folio_test_fscache(folio)) { | |
828 | folio_unlock(folio); | |
829 | folio_put(folio); | |
830 | xas_reset(xas); | |
831 | break; | |
832 | } | |
833 | ||
834 | stop = false; | |
835 | len = folio_size(folio); | |
836 | priv = folio_get_private(folio); | |
837 | if ((const struct netfs_group *)priv != group) { | |
838 | stop = true; | |
839 | finfo = netfs_folio_info(folio); | |
840 | if (finfo->netfs_group != group || | |
841 | finfo->dirty_offset > 0) { | |
842 | folio_unlock(folio); | |
843 | folio_put(folio); | |
844 | xas_reset(xas); | |
845 | break; | |
846 | } | |
847 | len = finfo->dirty_len; | |
848 | } | |
849 | ||
850 | *_top += folio_size(folio); | |
851 | index += folio_nr_pages(folio); | |
852 | *_count -= folio_nr_pages(folio); | |
853 | *_len += len; | |
854 | if (*_len >= max_len || *_count <= 0) | |
855 | stop = true; | |
856 | ||
857 | if (!folio_batch_add(&fbatch, folio)) | |
858 | break; | |
859 | if (stop) | |
860 | break; | |
861 | } | |
862 | ||
863 | xas_pause(xas); | |
864 | rcu_read_unlock(); | |
865 | ||
866 | /* Now, if we obtained any folios, we can shift them to being | |
867 | * writable and mark them for caching. | |
868 | */ | |
869 | if (!folio_batch_count(&fbatch)) | |
870 | break; | |
871 | ||
872 | for (i = 0; i < folio_batch_count(&fbatch); i++) { | |
873 | folio = fbatch.folios[i]; | |
874 | trace_netfs_folio(folio, netfs_folio_trace_store_plus); | |
875 | ||
876 | if (!folio_clear_dirty_for_io(folio)) | |
877 | BUG(); | |
878 | folio_start_writeback(folio); | |
879 | netfs_folio_start_fscache(caching, folio); | |
880 | folio_unlock(folio); | |
881 | } | |
882 | ||
883 | folio_batch_release(&fbatch); | |
884 | cond_resched(); | |
885 | } while (!stop); | |
886 | } | |
887 | ||
888 | /* | |
889 | * Synchronously write back the locked page and any subsequent non-locked dirty | |
890 | * pages. | |
891 | */ | |
892 | static ssize_t netfs_write_back_from_locked_folio(struct address_space *mapping, | |
893 | struct writeback_control *wbc, | |
894 | struct netfs_group *group, | |
895 | struct xa_state *xas, | |
896 | struct folio *folio, | |
897 | unsigned long long start, | |
898 | unsigned long long end) | |
899 | { | |
900 | struct netfs_io_request *wreq; | |
901 | struct netfs_folio *finfo; | |
902 | struct netfs_inode *ctx = netfs_inode(mapping->host); | |
903 | unsigned long long i_size = i_size_read(&ctx->inode); | |
904 | size_t len, max_len; | |
905 | bool caching = netfs_is_cache_enabled(ctx); | |
906 | long count = wbc->nr_to_write; | |
907 | int ret; | |
908 | ||
202bc57b | 909 | _enter(",%lx,%llx-%llx,%u", folio->index, start, end, caching); |
62c3b748 DH |
910 | |
911 | wreq = netfs_alloc_request(mapping, NULL, start, folio_size(folio), | |
912 | NETFS_WRITEBACK); | |
913 | if (IS_ERR(wreq)) { | |
914 | folio_unlock(folio); | |
915 | return PTR_ERR(wreq); | |
916 | } | |
917 | ||
918 | if (!folio_clear_dirty_for_io(folio)) | |
919 | BUG(); | |
920 | folio_start_writeback(folio); | |
921 | netfs_folio_start_fscache(caching, folio); | |
922 | ||
923 | count -= folio_nr_pages(folio); | |
924 | ||
925 | /* Find all consecutive lockable dirty pages that have contiguous | |
926 | * written regions, stopping when we find a page that is not | |
927 | * immediately lockable, is not dirty or is missing, or we reach the | |
928 | * end of the range. | |
929 | */ | |
930 | trace_netfs_folio(folio, netfs_folio_trace_store); | |
931 | ||
932 | len = wreq->len; | |
933 | finfo = netfs_folio_info(folio); | |
934 | if (finfo) { | |
935 | start += finfo->dirty_offset; | |
936 | if (finfo->dirty_offset + finfo->dirty_len != len) { | |
937 | len = finfo->dirty_len; | |
938 | goto cant_expand; | |
939 | } | |
940 | len = finfo->dirty_len; | |
941 | } | |
942 | ||
943 | if (start < i_size) { | |
944 | /* Trim the write to the EOF; the extra data is ignored. Also | |
945 | * put an upper limit on the size of a single storedata op. | |
946 | */ | |
947 | max_len = 65536 * 4096; | |
948 | max_len = min_t(unsigned long long, max_len, end - start + 1); | |
949 | max_len = min_t(unsigned long long, max_len, i_size - start); | |
950 | ||
951 | if (len < max_len) | |
952 | netfs_extend_writeback(mapping, group, xas, &count, start, | |
953 | max_len, caching, &len, &wreq->upper_len); | |
954 | } | |
955 | ||
956 | cant_expand: | |
957 | len = min_t(unsigned long long, len, i_size - start); | |
958 | ||
959 | /* We now have a contiguous set of dirty pages, each with writeback | |
960 | * set; the first page is still locked at this point, but all the rest | |
961 | * have been unlocked. | |
962 | */ | |
963 | folio_unlock(folio); | |
964 | wreq->start = start; | |
965 | wreq->len = len; | |
966 | ||
967 | if (start < i_size) { | |
968 | _debug("write back %zx @%llx [%llx]", len, start, i_size); | |
969 | ||
970 | /* Speculatively write to the cache. We have to fix this up | |
971 | * later if the store fails. | |
972 | */ | |
973 | wreq->cleanup = netfs_cleanup_buffered_write; | |
974 | ||
975 | iov_iter_xarray(&wreq->iter, ITER_SOURCE, &mapping->i_pages, start, | |
976 | wreq->upper_len); | |
977 | __set_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags); | |
978 | ret = netfs_begin_write(wreq, true, netfs_write_trace_writeback); | |
979 | if (ret == 0 || ret == -EIOCBQUEUED) | |
980 | wbc->nr_to_write -= len / PAGE_SIZE; | |
981 | } else { | |
982 | _debug("write discard %zx @%llx [%llx]", len, start, i_size); | |
983 | ||
984 | /* The dirty region was entirely beyond the EOF. */ | |
985 | fscache_clear_page_bits(mapping, start, len, caching); | |
986 | netfs_pages_written_back(wreq); | |
987 | ret = 0; | |
988 | } | |
989 | ||
990 | netfs_put_request(wreq, false, netfs_rreq_trace_put_return); | |
991 | _leave(" = 1"); | |
992 | return 1; | |
993 | } | |
994 | ||
995 | /* | |
996 | * Write a region of pages back to the server | |
997 | */ | |
998 | static ssize_t netfs_writepages_begin(struct address_space *mapping, | |
999 | struct writeback_control *wbc, | |
1000 | struct netfs_group *group, | |
1001 | struct xa_state *xas, | |
1002 | unsigned long long *_start, | |
1003 | unsigned long long end) | |
1004 | { | |
1005 | const struct netfs_folio *finfo; | |
1006 | struct folio *folio; | |
1007 | unsigned long long start = *_start; | |
1008 | ssize_t ret; | |
1009 | void *priv; | |
1010 | int skips = 0; | |
1011 | ||
1012 | _enter("%llx,%llx,", start, end); | |
1013 | ||
1014 | search_again: | |
1015 | /* Find the first dirty page in the group. */ | |
1016 | rcu_read_lock(); | |
1017 | ||
1018 | for (;;) { | |
1019 | folio = xas_find_marked(xas, end / PAGE_SIZE, PAGECACHE_TAG_DIRTY); | |
1020 | if (xas_retry(xas, folio) || xa_is_value(folio)) | |
1021 | continue; | |
1022 | if (!folio) | |
1023 | break; | |
1024 | ||
1025 | if (!folio_try_get_rcu(folio)) { | |
1026 | xas_reset(xas); | |
1027 | continue; | |
1028 | } | |
1029 | ||
1030 | if (unlikely(folio != xas_reload(xas))) { | |
1031 | folio_put(folio); | |
1032 | xas_reset(xas); | |
1033 | continue; | |
1034 | } | |
1035 | ||
1036 | /* Skip any dirty folio that's not in the group of interest. */ | |
1037 | priv = folio_get_private(folio); | |
1038 | if ((const struct netfs_group *)priv != group) { | |
1039 | finfo = netfs_folio_info(folio); | |
1040 | if (finfo->netfs_group != group) { | |
1041 | folio_put(folio); | |
1042 | continue; | |
1043 | } | |
1044 | } | |
1045 | ||
1046 | xas_pause(xas); | |
1047 | break; | |
1048 | } | |
1049 | rcu_read_unlock(); | |
1050 | if (!folio) | |
1051 | return 0; | |
1052 | ||
1053 | start = folio_pos(folio); /* May regress with THPs */ | |
1054 | ||
202bc57b | 1055 | _debug("wback %lx", folio->index); |
62c3b748 DH |
1056 | |
1057 | /* At this point we hold neither the i_pages lock nor the page lock: | |
1058 | * the page may be truncated or invalidated (changing page->mapping to | |
1059 | * NULL), or even swizzled back from swapper_space to tmpfs file | |
1060 | * mapping | |
1061 | */ | |
1062 | lock_again: | |
1063 | if (wbc->sync_mode != WB_SYNC_NONE) { | |
1064 | ret = folio_lock_killable(folio); | |
1065 | if (ret < 0) | |
1066 | return ret; | |
1067 | } else { | |
1068 | if (!folio_trylock(folio)) | |
1069 | goto search_again; | |
1070 | } | |
1071 | ||
1072 | if (folio->mapping != mapping || | |
1073 | !folio_test_dirty(folio)) { | |
1074 | start += folio_size(folio); | |
1075 | folio_unlock(folio); | |
1076 | goto search_again; | |
1077 | } | |
1078 | ||
1079 | if (folio_test_writeback(folio) || | |
1080 | folio_test_fscache(folio)) { | |
1081 | folio_unlock(folio); | |
1082 | if (wbc->sync_mode != WB_SYNC_NONE) { | |
1083 | folio_wait_writeback(folio); | |
e2bdb527 | 1084 | #ifdef CONFIG_FSCACHE |
62c3b748 DH |
1085 | folio_wait_fscache(folio); |
1086 | #endif | |
1087 | goto lock_again; | |
1088 | } | |
1089 | ||
1090 | start += folio_size(folio); | |
1091 | if (wbc->sync_mode == WB_SYNC_NONE) { | |
1092 | if (skips >= 5 || need_resched()) { | |
1093 | ret = 0; | |
1094 | goto out; | |
1095 | } | |
1096 | skips++; | |
1097 | } | |
1098 | goto search_again; | |
1099 | } | |
1100 | ||
1101 | ret = netfs_write_back_from_locked_folio(mapping, wbc, group, xas, | |
1102 | folio, start, end); | |
1103 | out: | |
1104 | if (ret > 0) | |
1105 | *_start = start + ret; | |
1106 | _leave(" = %zd [%llx]", ret, *_start); | |
1107 | return ret; | |
1108 | } | |
1109 | ||
1110 | /* | |
1111 | * Write a region of pages back to the server | |
1112 | */ | |
1113 | static int netfs_writepages_region(struct address_space *mapping, | |
1114 | struct writeback_control *wbc, | |
1115 | struct netfs_group *group, | |
1116 | unsigned long long *_start, | |
1117 | unsigned long long end) | |
1118 | { | |
1119 | ssize_t ret; | |
1120 | ||
1121 | XA_STATE(xas, &mapping->i_pages, *_start / PAGE_SIZE); | |
1122 | ||
1123 | do { | |
1124 | ret = netfs_writepages_begin(mapping, wbc, group, &xas, | |
1125 | _start, end); | |
1126 | if (ret > 0 && wbc->nr_to_write > 0) | |
1127 | cond_resched(); | |
1128 | } while (ret > 0 && wbc->nr_to_write > 0); | |
1129 | ||
1130 | return ret > 0 ? 0 : ret; | |
1131 | } | |
1132 | ||
1133 | /* | |
1134 | * write some of the pending data back to the server | |
1135 | */ | |
1136 | int netfs_writepages(struct address_space *mapping, | |
1137 | struct writeback_control *wbc) | |
1138 | { | |
1139 | struct netfs_group *group = NULL; | |
1140 | loff_t start, end; | |
1141 | int ret; | |
1142 | ||
1143 | _enter(""); | |
1144 | ||
1145 | /* We have to be careful as we can end up racing with setattr() | |
1146 | * truncating the pagecache since the caller doesn't take a lock here | |
1147 | * to prevent it. | |
1148 | */ | |
1149 | ||
1150 | if (wbc->range_cyclic && mapping->writeback_index) { | |
1151 | start = mapping->writeback_index * PAGE_SIZE; | |
1152 | ret = netfs_writepages_region(mapping, wbc, group, | |
1153 | &start, LLONG_MAX); | |
1154 | if (ret < 0) | |
1155 | goto out; | |
1156 | ||
1157 | if (wbc->nr_to_write <= 0) { | |
1158 | mapping->writeback_index = start / PAGE_SIZE; | |
1159 | goto out; | |
1160 | } | |
1161 | ||
1162 | start = 0; | |
1163 | end = mapping->writeback_index * PAGE_SIZE; | |
1164 | mapping->writeback_index = 0; | |
1165 | ret = netfs_writepages_region(mapping, wbc, group, &start, end); | |
1166 | if (ret == 0) | |
1167 | mapping->writeback_index = start / PAGE_SIZE; | |
1168 | } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) { | |
1169 | start = 0; | |
1170 | ret = netfs_writepages_region(mapping, wbc, group, | |
1171 | &start, LLONG_MAX); | |
1172 | if (wbc->nr_to_write > 0 && ret == 0) | |
1173 | mapping->writeback_index = start / PAGE_SIZE; | |
1174 | } else { | |
1175 | start = wbc->range_start; | |
1176 | ret = netfs_writepages_region(mapping, wbc, group, | |
1177 | &start, wbc->range_end); | |
1178 | } | |
1179 | ||
1180 | out: | |
1181 | _leave(" = %d", ret); | |
1182 | return ret; | |
1183 | } | |
1184 | EXPORT_SYMBOL(netfs_writepages); | |
4a79616c DH |
1185 | |
1186 | /* | |
1187 | * Deal with the disposition of a laundered folio. | |
1188 | */ | |
1189 | static void netfs_cleanup_launder_folio(struct netfs_io_request *wreq) | |
1190 | { | |
1191 | if (wreq->error) { | |
1192 | pr_notice("R=%08x Laundering error %d\n", wreq->debug_id, wreq->error); | |
1193 | mapping_set_error(wreq->mapping, wreq->error); | |
1194 | } | |
1195 | } | |
1196 | ||
1197 | /** | |
1198 | * netfs_launder_folio - Clean up a dirty folio that's being invalidated | |
1199 | * @folio: The folio to clean | |
1200 | * | |
1201 | * This is called to write back a folio that's being invalidated when an inode | |
1202 | * is getting torn down. Ideally, writepages would be used instead. | |
1203 | */ | |
1204 | int netfs_launder_folio(struct folio *folio) | |
1205 | { | |
1206 | struct netfs_io_request *wreq; | |
1207 | struct address_space *mapping = folio->mapping; | |
1208 | struct netfs_folio *finfo = netfs_folio_info(folio); | |
1209 | struct netfs_group *group = netfs_folio_group(folio); | |
1210 | struct bio_vec bvec; | |
1211 | unsigned long long i_size = i_size_read(mapping->host); | |
1212 | unsigned long long start = folio_pos(folio); | |
1213 | size_t offset = 0, len; | |
1214 | int ret = 0; | |
1215 | ||
1216 | if (finfo) { | |
1217 | offset = finfo->dirty_offset; | |
1218 | start += offset; | |
1219 | len = finfo->dirty_len; | |
1220 | } else { | |
1221 | len = folio_size(folio); | |
1222 | } | |
1223 | len = min_t(unsigned long long, len, i_size - start); | |
1224 | ||
1225 | wreq = netfs_alloc_request(mapping, NULL, start, len, NETFS_LAUNDER_WRITE); | |
1226 | if (IS_ERR(wreq)) { | |
1227 | ret = PTR_ERR(wreq); | |
1228 | goto out; | |
1229 | } | |
1230 | ||
1231 | if (!folio_clear_dirty_for_io(folio)) | |
1232 | goto out_put; | |
1233 | ||
1234 | trace_netfs_folio(folio, netfs_folio_trace_launder); | |
1235 | ||
1236 | _debug("launder %llx-%llx", start, start + len - 1); | |
1237 | ||
1238 | /* Speculatively write to the cache. We have to fix this up later if | |
1239 | * the store fails. | |
1240 | */ | |
1241 | wreq->cleanup = netfs_cleanup_launder_folio; | |
1242 | ||
1243 | bvec_set_folio(&bvec, folio, len, offset); | |
1244 | iov_iter_bvec(&wreq->iter, ITER_SOURCE, &bvec, 1, len); | |
1245 | __set_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags); | |
1246 | ret = netfs_begin_write(wreq, true, netfs_write_trace_launder); | |
1247 | ||
1248 | out_put: | |
1249 | folio_detach_private(folio); | |
1250 | netfs_put_group(group); | |
1251 | kfree(finfo); | |
1252 | netfs_put_request(wreq, false, netfs_rreq_trace_put_return); | |
1253 | out: | |
1254 | folio_wait_fscache(folio); | |
1255 | _leave(" = %d", ret); | |
1256 | return ret; | |
1257 | } | |
1258 | EXPORT_SYMBOL(netfs_launder_folio); |