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