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1 | /* | |
2 | * file.c - NTFS kernel file operations. Part of the Linux-NTFS project. | |
3 | * | |
4 | * Copyright (c) 2001-2015 Anton Altaparmakov and Tuxera Inc. | |
5 | * | |
6 | * This program/include file is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License as published | |
8 | * by the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program/include file is distributed in the hope that it will be | |
12 | * useful, but WITHOUT ANY WARRANTY; without even the implied warranty | |
13 | * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program (in the main directory of the Linux-NTFS | |
18 | * distribution in the file COPYING); if not, write to the Free Software | |
19 | * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
20 | */ | |
21 | ||
22 | #include <linux/backing-dev.h> | |
23 | #include <linux/buffer_head.h> | |
24 | #include <linux/gfp.h> | |
25 | #include <linux/pagemap.h> | |
26 | #include <linux/pagevec.h> | |
27 | #include <linux/sched/signal.h> | |
28 | #include <linux/swap.h> | |
29 | #include <linux/uio.h> | |
30 | #include <linux/writeback.h> | |
31 | ||
32 | #include <asm/page.h> | |
33 | #include <linux/uaccess.h> | |
34 | ||
35 | #include "attrib.h" | |
36 | #include "bitmap.h" | |
37 | #include "inode.h" | |
38 | #include "debug.h" | |
39 | #include "lcnalloc.h" | |
40 | #include "malloc.h" | |
41 | #include "mft.h" | |
42 | #include "ntfs.h" | |
43 | ||
44 | /** | |
45 | * ntfs_file_open - called when an inode is about to be opened | |
46 | * @vi: inode to be opened | |
47 | * @filp: file structure describing the inode | |
48 | * | |
49 | * Limit file size to the page cache limit on architectures where unsigned long | |
50 | * is 32-bits. This is the most we can do for now without overflowing the page | |
51 | * cache page index. Doing it this way means we don't run into problems because | |
52 | * of existing too large files. It would be better to allow the user to read | |
53 | * the beginning of the file but I doubt very much anyone is going to hit this | |
54 | * check on a 32-bit architecture, so there is no point in adding the extra | |
55 | * complexity required to support this. | |
56 | * | |
57 | * On 64-bit architectures, the check is hopefully optimized away by the | |
58 | * compiler. | |
59 | * | |
60 | * After the check passes, just call generic_file_open() to do its work. | |
61 | */ | |
62 | static int ntfs_file_open(struct inode *vi, struct file *filp) | |
63 | { | |
64 | if (sizeof(unsigned long) < 8) { | |
65 | if (i_size_read(vi) > MAX_LFS_FILESIZE) | |
66 | return -EOVERFLOW; | |
67 | } | |
68 | return generic_file_open(vi, filp); | |
69 | } | |
70 | ||
71 | #ifdef NTFS_RW | |
72 | ||
73 | /** | |
74 | * ntfs_attr_extend_initialized - extend the initialized size of an attribute | |
75 | * @ni: ntfs inode of the attribute to extend | |
76 | * @new_init_size: requested new initialized size in bytes | |
77 | * | |
78 | * Extend the initialized size of an attribute described by the ntfs inode @ni | |
79 | * to @new_init_size bytes. This involves zeroing any non-sparse space between | |
80 | * the old initialized size and @new_init_size both in the page cache and on | |
81 | * disk (if relevant complete pages are already uptodate in the page cache then | |
82 | * these are simply marked dirty). | |
83 | * | |
84 | * As a side-effect, the file size (vfs inode->i_size) may be incremented as, | |
85 | * in the resident attribute case, it is tied to the initialized size and, in | |
86 | * the non-resident attribute case, it may not fall below the initialized size. | |
87 | * | |
88 | * Note that if the attribute is resident, we do not need to touch the page | |
89 | * cache at all. This is because if the page cache page is not uptodate we | |
90 | * bring it uptodate later, when doing the write to the mft record since we | |
91 | * then already have the page mapped. And if the page is uptodate, the | |
92 | * non-initialized region will already have been zeroed when the page was | |
93 | * brought uptodate and the region may in fact already have been overwritten | |
94 | * with new data via mmap() based writes, so we cannot just zero it. And since | |
95 | * POSIX specifies that the behaviour of resizing a file whilst it is mmap()ped | |
96 | * is unspecified, we choose not to do zeroing and thus we do not need to touch | |
97 | * the page at all. For a more detailed explanation see ntfs_truncate() in | |
98 | * fs/ntfs/inode.c. | |
99 | * | |
100 | * Return 0 on success and -errno on error. In the case that an error is | |
101 | * encountered it is possible that the initialized size will already have been | |
102 | * incremented some way towards @new_init_size but it is guaranteed that if | |
103 | * this is the case, the necessary zeroing will also have happened and that all | |
104 | * metadata is self-consistent. | |
105 | * | |
106 | * Locking: i_mutex on the vfs inode corrseponsind to the ntfs inode @ni must be | |
107 | * held by the caller. | |
108 | */ | |
109 | static int ntfs_attr_extend_initialized(ntfs_inode *ni, const s64 new_init_size) | |
110 | { | |
111 | s64 old_init_size; | |
112 | loff_t old_i_size; | |
113 | pgoff_t index, end_index; | |
114 | unsigned long flags; | |
115 | struct inode *vi = VFS_I(ni); | |
116 | ntfs_inode *base_ni; | |
117 | MFT_RECORD *m = NULL; | |
118 | ATTR_RECORD *a; | |
119 | ntfs_attr_search_ctx *ctx = NULL; | |
120 | struct address_space *mapping; | |
121 | struct page *page = NULL; | |
122 | u8 *kattr; | |
123 | int err; | |
124 | u32 attr_len; | |
125 | ||
126 | read_lock_irqsave(&ni->size_lock, flags); | |
127 | old_init_size = ni->initialized_size; | |
128 | old_i_size = i_size_read(vi); | |
129 | BUG_ON(new_init_size > ni->allocated_size); | |
130 | read_unlock_irqrestore(&ni->size_lock, flags); | |
131 | ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, " | |
132 | "old_initialized_size 0x%llx, " | |
133 | "new_initialized_size 0x%llx, i_size 0x%llx.", | |
134 | vi->i_ino, (unsigned)le32_to_cpu(ni->type), | |
135 | (unsigned long long)old_init_size, | |
136 | (unsigned long long)new_init_size, old_i_size); | |
137 | if (!NInoAttr(ni)) | |
138 | base_ni = ni; | |
139 | else | |
140 | base_ni = ni->ext.base_ntfs_ino; | |
141 | /* Use goto to reduce indentation and we need the label below anyway. */ | |
142 | if (NInoNonResident(ni)) | |
143 | goto do_non_resident_extend; | |
144 | BUG_ON(old_init_size != old_i_size); | |
145 | m = map_mft_record(base_ni); | |
146 | if (IS_ERR(m)) { | |
147 | err = PTR_ERR(m); | |
148 | m = NULL; | |
149 | goto err_out; | |
150 | } | |
151 | ctx = ntfs_attr_get_search_ctx(base_ni, m); | |
152 | if (unlikely(!ctx)) { | |
153 | err = -ENOMEM; | |
154 | goto err_out; | |
155 | } | |
156 | err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, | |
157 | CASE_SENSITIVE, 0, NULL, 0, ctx); | |
158 | if (unlikely(err)) { | |
159 | if (err == -ENOENT) | |
160 | err = -EIO; | |
161 | goto err_out; | |
162 | } | |
163 | m = ctx->mrec; | |
164 | a = ctx->attr; | |
165 | BUG_ON(a->non_resident); | |
166 | /* The total length of the attribute value. */ | |
167 | attr_len = le32_to_cpu(a->data.resident.value_length); | |
168 | BUG_ON(old_i_size != (loff_t)attr_len); | |
169 | /* | |
170 | * Do the zeroing in the mft record and update the attribute size in | |
171 | * the mft record. | |
172 | */ | |
173 | kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset); | |
174 | memset(kattr + attr_len, 0, new_init_size - attr_len); | |
175 | a->data.resident.value_length = cpu_to_le32((u32)new_init_size); | |
176 | /* Finally, update the sizes in the vfs and ntfs inodes. */ | |
177 | write_lock_irqsave(&ni->size_lock, flags); | |
178 | i_size_write(vi, new_init_size); | |
179 | ni->initialized_size = new_init_size; | |
180 | write_unlock_irqrestore(&ni->size_lock, flags); | |
181 | goto done; | |
182 | do_non_resident_extend: | |
183 | /* | |
184 | * If the new initialized size @new_init_size exceeds the current file | |
185 | * size (vfs inode->i_size), we need to extend the file size to the | |
186 | * new initialized size. | |
187 | */ | |
188 | if (new_init_size > old_i_size) { | |
189 | m = map_mft_record(base_ni); | |
190 | if (IS_ERR(m)) { | |
191 | err = PTR_ERR(m); | |
192 | m = NULL; | |
193 | goto err_out; | |
194 | } | |
195 | ctx = ntfs_attr_get_search_ctx(base_ni, m); | |
196 | if (unlikely(!ctx)) { | |
197 | err = -ENOMEM; | |
198 | goto err_out; | |
199 | } | |
200 | err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, | |
201 | CASE_SENSITIVE, 0, NULL, 0, ctx); | |
202 | if (unlikely(err)) { | |
203 | if (err == -ENOENT) | |
204 | err = -EIO; | |
205 | goto err_out; | |
206 | } | |
207 | m = ctx->mrec; | |
208 | a = ctx->attr; | |
209 | BUG_ON(!a->non_resident); | |
210 | BUG_ON(old_i_size != (loff_t) | |
211 | sle64_to_cpu(a->data.non_resident.data_size)); | |
212 | a->data.non_resident.data_size = cpu_to_sle64(new_init_size); | |
213 | flush_dcache_mft_record_page(ctx->ntfs_ino); | |
214 | mark_mft_record_dirty(ctx->ntfs_ino); | |
215 | /* Update the file size in the vfs inode. */ | |
216 | i_size_write(vi, new_init_size); | |
217 | ntfs_attr_put_search_ctx(ctx); | |
218 | ctx = NULL; | |
219 | unmap_mft_record(base_ni); | |
220 | m = NULL; | |
221 | } | |
222 | mapping = vi->i_mapping; | |
223 | index = old_init_size >> PAGE_SHIFT; | |
224 | end_index = (new_init_size + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
225 | do { | |
226 | /* | |
227 | * Read the page. If the page is not present, this will zero | |
228 | * the uninitialized regions for us. | |
229 | */ | |
230 | page = read_mapping_page(mapping, index, NULL); | |
231 | if (IS_ERR(page)) { | |
232 | err = PTR_ERR(page); | |
233 | goto init_err_out; | |
234 | } | |
235 | if (unlikely(PageError(page))) { | |
236 | put_page(page); | |
237 | err = -EIO; | |
238 | goto init_err_out; | |
239 | } | |
240 | /* | |
241 | * Update the initialized size in the ntfs inode. This is | |
242 | * enough to make ntfs_writepage() work. | |
243 | */ | |
244 | write_lock_irqsave(&ni->size_lock, flags); | |
245 | ni->initialized_size = (s64)(index + 1) << PAGE_SHIFT; | |
246 | if (ni->initialized_size > new_init_size) | |
247 | ni->initialized_size = new_init_size; | |
248 | write_unlock_irqrestore(&ni->size_lock, flags); | |
249 | /* Set the page dirty so it gets written out. */ | |
250 | set_page_dirty(page); | |
251 | put_page(page); | |
252 | /* | |
253 | * Play nice with the vm and the rest of the system. This is | |
254 | * very much needed as we can potentially be modifying the | |
255 | * initialised size from a very small value to a really huge | |
256 | * value, e.g. | |
257 | * f = open(somefile, O_TRUNC); | |
258 | * truncate(f, 10GiB); | |
259 | * seek(f, 10GiB); | |
260 | * write(f, 1); | |
261 | * And this would mean we would be marking dirty hundreds of | |
262 | * thousands of pages or as in the above example more than | |
263 | * two and a half million pages! | |
264 | * | |
265 | * TODO: For sparse pages could optimize this workload by using | |
266 | * the FsMisc / MiscFs page bit as a "PageIsSparse" bit. This | |
267 | * would be set in readpage for sparse pages and here we would | |
268 | * not need to mark dirty any pages which have this bit set. | |
269 | * The only caveat is that we have to clear the bit everywhere | |
270 | * where we allocate any clusters that lie in the page or that | |
271 | * contain the page. | |
272 | * | |
273 | * TODO: An even greater optimization would be for us to only | |
274 | * call readpage() on pages which are not in sparse regions as | |
275 | * determined from the runlist. This would greatly reduce the | |
276 | * number of pages we read and make dirty in the case of sparse | |
277 | * files. | |
278 | */ | |
279 | balance_dirty_pages_ratelimited(mapping); | |
280 | cond_resched(); | |
281 | } while (++index < end_index); | |
282 | read_lock_irqsave(&ni->size_lock, flags); | |
283 | BUG_ON(ni->initialized_size != new_init_size); | |
284 | read_unlock_irqrestore(&ni->size_lock, flags); | |
285 | /* Now bring in sync the initialized_size in the mft record. */ | |
286 | m = map_mft_record(base_ni); | |
287 | if (IS_ERR(m)) { | |
288 | err = PTR_ERR(m); | |
289 | m = NULL; | |
290 | goto init_err_out; | |
291 | } | |
292 | ctx = ntfs_attr_get_search_ctx(base_ni, m); | |
293 | if (unlikely(!ctx)) { | |
294 | err = -ENOMEM; | |
295 | goto init_err_out; | |
296 | } | |
297 | err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, | |
298 | CASE_SENSITIVE, 0, NULL, 0, ctx); | |
299 | if (unlikely(err)) { | |
300 | if (err == -ENOENT) | |
301 | err = -EIO; | |
302 | goto init_err_out; | |
303 | } | |
304 | m = ctx->mrec; | |
305 | a = ctx->attr; | |
306 | BUG_ON(!a->non_resident); | |
307 | a->data.non_resident.initialized_size = cpu_to_sle64(new_init_size); | |
308 | done: | |
309 | flush_dcache_mft_record_page(ctx->ntfs_ino); | |
310 | mark_mft_record_dirty(ctx->ntfs_ino); | |
311 | if (ctx) | |
312 | ntfs_attr_put_search_ctx(ctx); | |
313 | if (m) | |
314 | unmap_mft_record(base_ni); | |
315 | ntfs_debug("Done, initialized_size 0x%llx, i_size 0x%llx.", | |
316 | (unsigned long long)new_init_size, i_size_read(vi)); | |
317 | return 0; | |
318 | init_err_out: | |
319 | write_lock_irqsave(&ni->size_lock, flags); | |
320 | ni->initialized_size = old_init_size; | |
321 | write_unlock_irqrestore(&ni->size_lock, flags); | |
322 | err_out: | |
323 | if (ctx) | |
324 | ntfs_attr_put_search_ctx(ctx); | |
325 | if (m) | |
326 | unmap_mft_record(base_ni); | |
327 | ntfs_debug("Failed. Returning error code %i.", err); | |
328 | return err; | |
329 | } | |
330 | ||
331 | static ssize_t ntfs_prepare_file_for_write(struct kiocb *iocb, | |
332 | struct iov_iter *from) | |
333 | { | |
334 | loff_t pos; | |
335 | s64 end, ll; | |
336 | ssize_t err; | |
337 | unsigned long flags; | |
338 | struct file *file = iocb->ki_filp; | |
339 | struct inode *vi = file_inode(file); | |
340 | ntfs_inode *base_ni, *ni = NTFS_I(vi); | |
341 | ntfs_volume *vol = ni->vol; | |
342 | ||
343 | ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, pos " | |
344 | "0x%llx, count 0x%zx.", vi->i_ino, | |
345 | (unsigned)le32_to_cpu(ni->type), | |
346 | (unsigned long long)iocb->ki_pos, | |
347 | iov_iter_count(from)); | |
348 | err = generic_write_checks(iocb, from); | |
349 | if (unlikely(err <= 0)) | |
350 | goto out; | |
351 | /* | |
352 | * All checks have passed. Before we start doing any writing we want | |
353 | * to abort any totally illegal writes. | |
354 | */ | |
355 | BUG_ON(NInoMstProtected(ni)); | |
356 | BUG_ON(ni->type != AT_DATA); | |
357 | /* If file is encrypted, deny access, just like NT4. */ | |
358 | if (NInoEncrypted(ni)) { | |
359 | /* Only $DATA attributes can be encrypted. */ | |
360 | /* | |
361 | * Reminder for later: Encrypted files are _always_ | |
362 | * non-resident so that the content can always be encrypted. | |
363 | */ | |
364 | ntfs_debug("Denying write access to encrypted file."); | |
365 | err = -EACCES; | |
366 | goto out; | |
367 | } | |
368 | if (NInoCompressed(ni)) { | |
369 | /* Only unnamed $DATA attribute can be compressed. */ | |
370 | BUG_ON(ni->name_len); | |
371 | /* | |
372 | * Reminder for later: If resident, the data is not actually | |
373 | * compressed. Only on the switch to non-resident does | |
374 | * compression kick in. This is in contrast to encrypted files | |
375 | * (see above). | |
376 | */ | |
377 | ntfs_error(vi->i_sb, "Writing to compressed files is not " | |
378 | "implemented yet. Sorry."); | |
379 | err = -EOPNOTSUPP; | |
380 | goto out; | |
381 | } | |
382 | base_ni = ni; | |
383 | if (NInoAttr(ni)) | |
384 | base_ni = ni->ext.base_ntfs_ino; | |
385 | err = file_remove_privs(file); | |
386 | if (unlikely(err)) | |
387 | goto out; | |
388 | /* | |
389 | * Our ->update_time method always succeeds thus file_update_time() | |
390 | * cannot fail either so there is no need to check the return code. | |
391 | */ | |
392 | file_update_time(file); | |
393 | pos = iocb->ki_pos; | |
394 | /* The first byte after the last cluster being written to. */ | |
395 | end = (pos + iov_iter_count(from) + vol->cluster_size_mask) & | |
396 | ~(u64)vol->cluster_size_mask; | |
397 | /* | |
398 | * If the write goes beyond the allocated size, extend the allocation | |
399 | * to cover the whole of the write, rounded up to the nearest cluster. | |
400 | */ | |
401 | read_lock_irqsave(&ni->size_lock, flags); | |
402 | ll = ni->allocated_size; | |
403 | read_unlock_irqrestore(&ni->size_lock, flags); | |
404 | if (end > ll) { | |
405 | /* | |
406 | * Extend the allocation without changing the data size. | |
407 | * | |
408 | * Note we ensure the allocation is big enough to at least | |
409 | * write some data but we do not require the allocation to be | |
410 | * complete, i.e. it may be partial. | |
411 | */ | |
412 | ll = ntfs_attr_extend_allocation(ni, end, -1, pos); | |
413 | if (likely(ll >= 0)) { | |
414 | BUG_ON(pos >= ll); | |
415 | /* If the extension was partial truncate the write. */ | |
416 | if (end > ll) { | |
417 | ntfs_debug("Truncating write to inode 0x%lx, " | |
418 | "attribute type 0x%x, because " | |
419 | "the allocation was only " | |
420 | "partially extended.", | |
421 | vi->i_ino, (unsigned) | |
422 | le32_to_cpu(ni->type)); | |
423 | iov_iter_truncate(from, ll - pos); | |
424 | } | |
425 | } else { | |
426 | err = ll; | |
427 | read_lock_irqsave(&ni->size_lock, flags); | |
428 | ll = ni->allocated_size; | |
429 | read_unlock_irqrestore(&ni->size_lock, flags); | |
430 | /* Perform a partial write if possible or fail. */ | |
431 | if (pos < ll) { | |
432 | ntfs_debug("Truncating write to inode 0x%lx " | |
433 | "attribute type 0x%x, because " | |
434 | "extending the allocation " | |
435 | "failed (error %d).", | |
436 | vi->i_ino, (unsigned) | |
437 | le32_to_cpu(ni->type), | |
438 | (int)-err); | |
439 | iov_iter_truncate(from, ll - pos); | |
440 | } else { | |
441 | if (err != -ENOSPC) | |
442 | ntfs_error(vi->i_sb, "Cannot perform " | |
443 | "write to inode " | |
444 | "0x%lx, attribute " | |
445 | "type 0x%x, because " | |
446 | "extending the " | |
447 | "allocation failed " | |
448 | "(error %ld).", | |
449 | vi->i_ino, (unsigned) | |
450 | le32_to_cpu(ni->type), | |
451 | (long)-err); | |
452 | else | |
453 | ntfs_debug("Cannot perform write to " | |
454 | "inode 0x%lx, " | |
455 | "attribute type 0x%x, " | |
456 | "because there is not " | |
457 | "space left.", | |
458 | vi->i_ino, (unsigned) | |
459 | le32_to_cpu(ni->type)); | |
460 | goto out; | |
461 | } | |
462 | } | |
463 | } | |
464 | /* | |
465 | * If the write starts beyond the initialized size, extend it up to the | |
466 | * beginning of the write and initialize all non-sparse space between | |
467 | * the old initialized size and the new one. This automatically also | |
468 | * increments the vfs inode->i_size to keep it above or equal to the | |
469 | * initialized_size. | |
470 | */ | |
471 | read_lock_irqsave(&ni->size_lock, flags); | |
472 | ll = ni->initialized_size; | |
473 | read_unlock_irqrestore(&ni->size_lock, flags); | |
474 | if (pos > ll) { | |
475 | /* | |
476 | * Wait for ongoing direct i/o to complete before proceeding. | |
477 | * New direct i/o cannot start as we hold i_mutex. | |
478 | */ | |
479 | inode_dio_wait(vi); | |
480 | err = ntfs_attr_extend_initialized(ni, pos); | |
481 | if (unlikely(err < 0)) | |
482 | ntfs_error(vi->i_sb, "Cannot perform write to inode " | |
483 | "0x%lx, attribute type 0x%x, because " | |
484 | "extending the initialized size " | |
485 | "failed (error %d).", vi->i_ino, | |
486 | (unsigned)le32_to_cpu(ni->type), | |
487 | (int)-err); | |
488 | } | |
489 | out: | |
490 | return err; | |
491 | } | |
492 | ||
493 | /** | |
494 | * __ntfs_grab_cache_pages - obtain a number of locked pages | |
495 | * @mapping: address space mapping from which to obtain page cache pages | |
496 | * @index: starting index in @mapping at which to begin obtaining pages | |
497 | * @nr_pages: number of page cache pages to obtain | |
498 | * @pages: array of pages in which to return the obtained page cache pages | |
499 | * @cached_page: allocated but as yet unused page | |
500 | * | |
501 | * Obtain @nr_pages locked page cache pages from the mapping @mapping and | |
502 | * starting at index @index. | |
503 | * | |
504 | * If a page is newly created, add it to lru list | |
505 | * | |
506 | * Note, the page locks are obtained in ascending page index order. | |
507 | */ | |
508 | static inline int __ntfs_grab_cache_pages(struct address_space *mapping, | |
509 | pgoff_t index, const unsigned nr_pages, struct page **pages, | |
510 | struct page **cached_page) | |
511 | { | |
512 | int err, nr; | |
513 | ||
514 | BUG_ON(!nr_pages); | |
515 | err = nr = 0; | |
516 | do { | |
517 | pages[nr] = find_get_page_flags(mapping, index, FGP_LOCK | | |
518 | FGP_ACCESSED); | |
519 | if (!pages[nr]) { | |
520 | if (!*cached_page) { | |
521 | *cached_page = page_cache_alloc(mapping); | |
522 | if (unlikely(!*cached_page)) { | |
523 | err = -ENOMEM; | |
524 | goto err_out; | |
525 | } | |
526 | } | |
527 | err = add_to_page_cache_lru(*cached_page, mapping, | |
528 | index, | |
529 | mapping_gfp_constraint(mapping, GFP_KERNEL)); | |
530 | if (unlikely(err)) { | |
531 | if (err == -EEXIST) | |
532 | continue; | |
533 | goto err_out; | |
534 | } | |
535 | pages[nr] = *cached_page; | |
536 | *cached_page = NULL; | |
537 | } | |
538 | index++; | |
539 | nr++; | |
540 | } while (nr < nr_pages); | |
541 | out: | |
542 | return err; | |
543 | err_out: | |
544 | while (nr > 0) { | |
545 | unlock_page(pages[--nr]); | |
546 | put_page(pages[nr]); | |
547 | } | |
548 | goto out; | |
549 | } | |
550 | ||
551 | static inline int ntfs_submit_bh_for_read(struct buffer_head *bh) | |
552 | { | |
553 | lock_buffer(bh); | |
554 | get_bh(bh); | |
555 | bh->b_end_io = end_buffer_read_sync; | |
556 | return submit_bh(REQ_OP_READ, 0, bh); | |
557 | } | |
558 | ||
559 | /** | |
560 | * ntfs_prepare_pages_for_non_resident_write - prepare pages for receiving data | |
561 | * @pages: array of destination pages | |
562 | * @nr_pages: number of pages in @pages | |
563 | * @pos: byte position in file at which the write begins | |
564 | * @bytes: number of bytes to be written | |
565 | * | |
566 | * This is called for non-resident attributes from ntfs_file_buffered_write() | |
567 | * with i_mutex held on the inode (@pages[0]->mapping->host). There are | |
568 | * @nr_pages pages in @pages which are locked but not kmap()ped. The source | |
569 | * data has not yet been copied into the @pages. | |
570 | * | |
571 | * Need to fill any holes with actual clusters, allocate buffers if necessary, | |
572 | * ensure all the buffers are mapped, and bring uptodate any buffers that are | |
573 | * only partially being written to. | |
574 | * | |
575 | * If @nr_pages is greater than one, we are guaranteed that the cluster size is | |
576 | * greater than PAGE_SIZE, that all pages in @pages are entirely inside | |
577 | * the same cluster and that they are the entirety of that cluster, and that | |
578 | * the cluster is sparse, i.e. we need to allocate a cluster to fill the hole. | |
579 | * | |
580 | * i_size is not to be modified yet. | |
581 | * | |
582 | * Return 0 on success or -errno on error. | |
583 | */ | |
584 | static int ntfs_prepare_pages_for_non_resident_write(struct page **pages, | |
585 | unsigned nr_pages, s64 pos, size_t bytes) | |
586 | { | |
587 | VCN vcn, highest_vcn = 0, cpos, cend, bh_cpos, bh_cend; | |
588 | LCN lcn; | |
589 | s64 bh_pos, vcn_len, end, initialized_size; | |
590 | sector_t lcn_block; | |
591 | struct page *page; | |
592 | struct inode *vi; | |
593 | ntfs_inode *ni, *base_ni = NULL; | |
594 | ntfs_volume *vol; | |
595 | runlist_element *rl, *rl2; | |
596 | struct buffer_head *bh, *head, *wait[2], **wait_bh = wait; | |
597 | ntfs_attr_search_ctx *ctx = NULL; | |
598 | MFT_RECORD *m = NULL; | |
599 | ATTR_RECORD *a = NULL; | |
600 | unsigned long flags; | |
601 | u32 attr_rec_len = 0; | |
602 | unsigned blocksize, u; | |
603 | int err, mp_size; | |
604 | bool rl_write_locked, was_hole, is_retry; | |
605 | unsigned char blocksize_bits; | |
606 | struct { | |
607 | u8 runlist_merged:1; | |
608 | u8 mft_attr_mapped:1; | |
609 | u8 mp_rebuilt:1; | |
610 | u8 attr_switched:1; | |
611 | } status = { 0, 0, 0, 0 }; | |
612 | ||
613 | BUG_ON(!nr_pages); | |
614 | BUG_ON(!pages); | |
615 | BUG_ON(!*pages); | |
616 | vi = pages[0]->mapping->host; | |
617 | ni = NTFS_I(vi); | |
618 | vol = ni->vol; | |
619 | ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page " | |
620 | "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.", | |
621 | vi->i_ino, ni->type, pages[0]->index, nr_pages, | |
622 | (long long)pos, bytes); | |
623 | blocksize = vol->sb->s_blocksize; | |
624 | blocksize_bits = vol->sb->s_blocksize_bits; | |
625 | u = 0; | |
626 | do { | |
627 | page = pages[u]; | |
628 | BUG_ON(!page); | |
629 | /* | |
630 | * create_empty_buffers() will create uptodate/dirty buffers if | |
631 | * the page is uptodate/dirty. | |
632 | */ | |
633 | if (!page_has_buffers(page)) { | |
634 | create_empty_buffers(page, blocksize, 0); | |
635 | if (unlikely(!page_has_buffers(page))) | |
636 | return -ENOMEM; | |
637 | } | |
638 | } while (++u < nr_pages); | |
639 | rl_write_locked = false; | |
640 | rl = NULL; | |
641 | err = 0; | |
642 | vcn = lcn = -1; | |
643 | vcn_len = 0; | |
644 | lcn_block = -1; | |
645 | was_hole = false; | |
646 | cpos = pos >> vol->cluster_size_bits; | |
647 | end = pos + bytes; | |
648 | cend = (end + vol->cluster_size - 1) >> vol->cluster_size_bits; | |
649 | /* | |
650 | * Loop over each page and for each page over each buffer. Use goto to | |
651 | * reduce indentation. | |
652 | */ | |
653 | u = 0; | |
654 | do_next_page: | |
655 | page = pages[u]; | |
656 | bh_pos = (s64)page->index << PAGE_SHIFT; | |
657 | bh = head = page_buffers(page); | |
658 | do { | |
659 | VCN cdelta; | |
660 | s64 bh_end; | |
661 | unsigned bh_cofs; | |
662 | ||
663 | /* Clear buffer_new on all buffers to reinitialise state. */ | |
664 | if (buffer_new(bh)) | |
665 | clear_buffer_new(bh); | |
666 | bh_end = bh_pos + blocksize; | |
667 | bh_cpos = bh_pos >> vol->cluster_size_bits; | |
668 | bh_cofs = bh_pos & vol->cluster_size_mask; | |
669 | if (buffer_mapped(bh)) { | |
670 | /* | |
671 | * The buffer is already mapped. If it is uptodate, | |
672 | * ignore it. | |
673 | */ | |
674 | if (buffer_uptodate(bh)) | |
675 | continue; | |
676 | /* | |
677 | * The buffer is not uptodate. If the page is uptodate | |
678 | * set the buffer uptodate and otherwise ignore it. | |
679 | */ | |
680 | if (PageUptodate(page)) { | |
681 | set_buffer_uptodate(bh); | |
682 | continue; | |
683 | } | |
684 | /* | |
685 | * Neither the page nor the buffer are uptodate. If | |
686 | * the buffer is only partially being written to, we | |
687 | * need to read it in before the write, i.e. now. | |
688 | */ | |
689 | if ((bh_pos < pos && bh_end > pos) || | |
690 | (bh_pos < end && bh_end > end)) { | |
691 | /* | |
692 | * If the buffer is fully or partially within | |
693 | * the initialized size, do an actual read. | |
694 | * Otherwise, simply zero the buffer. | |
695 | */ | |
696 | read_lock_irqsave(&ni->size_lock, flags); | |
697 | initialized_size = ni->initialized_size; | |
698 | read_unlock_irqrestore(&ni->size_lock, flags); | |
699 | if (bh_pos < initialized_size) { | |
700 | ntfs_submit_bh_for_read(bh); | |
701 | *wait_bh++ = bh; | |
702 | } else { | |
703 | zero_user(page, bh_offset(bh), | |
704 | blocksize); | |
705 | set_buffer_uptodate(bh); | |
706 | } | |
707 | } | |
708 | continue; | |
709 | } | |
710 | /* Unmapped buffer. Need to map it. */ | |
711 | bh->b_bdev = vol->sb->s_bdev; | |
712 | /* | |
713 | * If the current buffer is in the same clusters as the map | |
714 | * cache, there is no need to check the runlist again. The | |
715 | * map cache is made up of @vcn, which is the first cached file | |
716 | * cluster, @vcn_len which is the number of cached file | |
717 | * clusters, @lcn is the device cluster corresponding to @vcn, | |
718 | * and @lcn_block is the block number corresponding to @lcn. | |
719 | */ | |
720 | cdelta = bh_cpos - vcn; | |
721 | if (likely(!cdelta || (cdelta > 0 && cdelta < vcn_len))) { | |
722 | map_buffer_cached: | |
723 | BUG_ON(lcn < 0); | |
724 | bh->b_blocknr = lcn_block + | |
725 | (cdelta << (vol->cluster_size_bits - | |
726 | blocksize_bits)) + | |
727 | (bh_cofs >> blocksize_bits); | |
728 | set_buffer_mapped(bh); | |
729 | /* | |
730 | * If the page is uptodate so is the buffer. If the | |
731 | * buffer is fully outside the write, we ignore it if | |
732 | * it was already allocated and we mark it dirty so it | |
733 | * gets written out if we allocated it. On the other | |
734 | * hand, if we allocated the buffer but we are not | |
735 | * marking it dirty we set buffer_new so we can do | |
736 | * error recovery. | |
737 | */ | |
738 | if (PageUptodate(page)) { | |
739 | if (!buffer_uptodate(bh)) | |
740 | set_buffer_uptodate(bh); | |
741 | if (unlikely(was_hole)) { | |
742 | /* We allocated the buffer. */ | |
743 | clean_bdev_bh_alias(bh); | |
744 | if (bh_end <= pos || bh_pos >= end) | |
745 | mark_buffer_dirty(bh); | |
746 | else | |
747 | set_buffer_new(bh); | |
748 | } | |
749 | continue; | |
750 | } | |
751 | /* Page is _not_ uptodate. */ | |
752 | if (likely(!was_hole)) { | |
753 | /* | |
754 | * Buffer was already allocated. If it is not | |
755 | * uptodate and is only partially being written | |
756 | * to, we need to read it in before the write, | |
757 | * i.e. now. | |
758 | */ | |
759 | if (!buffer_uptodate(bh) && bh_pos < end && | |
760 | bh_end > pos && | |
761 | (bh_pos < pos || | |
762 | bh_end > end)) { | |
763 | /* | |
764 | * If the buffer is fully or partially | |
765 | * within the initialized size, do an | |
766 | * actual read. Otherwise, simply zero | |
767 | * the buffer. | |
768 | */ | |
769 | read_lock_irqsave(&ni->size_lock, | |
770 | flags); | |
771 | initialized_size = ni->initialized_size; | |
772 | read_unlock_irqrestore(&ni->size_lock, | |
773 | flags); | |
774 | if (bh_pos < initialized_size) { | |
775 | ntfs_submit_bh_for_read(bh); | |
776 | *wait_bh++ = bh; | |
777 | } else { | |
778 | zero_user(page, bh_offset(bh), | |
779 | blocksize); | |
780 | set_buffer_uptodate(bh); | |
781 | } | |
782 | } | |
783 | continue; | |
784 | } | |
785 | /* We allocated the buffer. */ | |
786 | clean_bdev_bh_alias(bh); | |
787 | /* | |
788 | * If the buffer is fully outside the write, zero it, | |
789 | * set it uptodate, and mark it dirty so it gets | |
790 | * written out. If it is partially being written to, | |
791 | * zero region surrounding the write but leave it to | |
792 | * commit write to do anything else. Finally, if the | |
793 | * buffer is fully being overwritten, do nothing. | |
794 | */ | |
795 | if (bh_end <= pos || bh_pos >= end) { | |
796 | if (!buffer_uptodate(bh)) { | |
797 | zero_user(page, bh_offset(bh), | |
798 | blocksize); | |
799 | set_buffer_uptodate(bh); | |
800 | } | |
801 | mark_buffer_dirty(bh); | |
802 | continue; | |
803 | } | |
804 | set_buffer_new(bh); | |
805 | if (!buffer_uptodate(bh) && | |
806 | (bh_pos < pos || bh_end > end)) { | |
807 | u8 *kaddr; | |
808 | unsigned pofs; | |
809 | ||
810 | kaddr = kmap_atomic(page); | |
811 | if (bh_pos < pos) { | |
812 | pofs = bh_pos & ~PAGE_MASK; | |
813 | memset(kaddr + pofs, 0, pos - bh_pos); | |
814 | } | |
815 | if (bh_end > end) { | |
816 | pofs = end & ~PAGE_MASK; | |
817 | memset(kaddr + pofs, 0, bh_end - end); | |
818 | } | |
819 | kunmap_atomic(kaddr); | |
820 | flush_dcache_page(page); | |
821 | } | |
822 | continue; | |
823 | } | |
824 | /* | |
825 | * Slow path: this is the first buffer in the cluster. If it | |
826 | * is outside allocated size and is not uptodate, zero it and | |
827 | * set it uptodate. | |
828 | */ | |
829 | read_lock_irqsave(&ni->size_lock, flags); | |
830 | initialized_size = ni->allocated_size; | |
831 | read_unlock_irqrestore(&ni->size_lock, flags); | |
832 | if (bh_pos > initialized_size) { | |
833 | if (PageUptodate(page)) { | |
834 | if (!buffer_uptodate(bh)) | |
835 | set_buffer_uptodate(bh); | |
836 | } else if (!buffer_uptodate(bh)) { | |
837 | zero_user(page, bh_offset(bh), blocksize); | |
838 | set_buffer_uptodate(bh); | |
839 | } | |
840 | continue; | |
841 | } | |
842 | is_retry = false; | |
843 | if (!rl) { | |
844 | down_read(&ni->runlist.lock); | |
845 | retry_remap: | |
846 | rl = ni->runlist.rl; | |
847 | } | |
848 | if (likely(rl != NULL)) { | |
849 | /* Seek to element containing target cluster. */ | |
850 | while (rl->length && rl[1].vcn <= bh_cpos) | |
851 | rl++; | |
852 | lcn = ntfs_rl_vcn_to_lcn(rl, bh_cpos); | |
853 | if (likely(lcn >= 0)) { | |
854 | /* | |
855 | * Successful remap, setup the map cache and | |
856 | * use that to deal with the buffer. | |
857 | */ | |
858 | was_hole = false; | |
859 | vcn = bh_cpos; | |
860 | vcn_len = rl[1].vcn - vcn; | |
861 | lcn_block = lcn << (vol->cluster_size_bits - | |
862 | blocksize_bits); | |
863 | cdelta = 0; | |
864 | /* | |
865 | * If the number of remaining clusters touched | |
866 | * by the write is smaller or equal to the | |
867 | * number of cached clusters, unlock the | |
868 | * runlist as the map cache will be used from | |
869 | * now on. | |
870 | */ | |
871 | if (likely(vcn + vcn_len >= cend)) { | |
872 | if (rl_write_locked) { | |
873 | up_write(&ni->runlist.lock); | |
874 | rl_write_locked = false; | |
875 | } else | |
876 | up_read(&ni->runlist.lock); | |
877 | rl = NULL; | |
878 | } | |
879 | goto map_buffer_cached; | |
880 | } | |
881 | } else | |
882 | lcn = LCN_RL_NOT_MAPPED; | |
883 | /* | |
884 | * If it is not a hole and not out of bounds, the runlist is | |
885 | * probably unmapped so try to map it now. | |
886 | */ | |
887 | if (unlikely(lcn != LCN_HOLE && lcn != LCN_ENOENT)) { | |
888 | if (likely(!is_retry && lcn == LCN_RL_NOT_MAPPED)) { | |
889 | /* Attempt to map runlist. */ | |
890 | if (!rl_write_locked) { | |
891 | /* | |
892 | * We need the runlist locked for | |
893 | * writing, so if it is locked for | |
894 | * reading relock it now and retry in | |
895 | * case it changed whilst we dropped | |
896 | * the lock. | |
897 | */ | |
898 | up_read(&ni->runlist.lock); | |
899 | down_write(&ni->runlist.lock); | |
900 | rl_write_locked = true; | |
901 | goto retry_remap; | |
902 | } | |
903 | err = ntfs_map_runlist_nolock(ni, bh_cpos, | |
904 | NULL); | |
905 | if (likely(!err)) { | |
906 | is_retry = true; | |
907 | goto retry_remap; | |
908 | } | |
909 | /* | |
910 | * If @vcn is out of bounds, pretend @lcn is | |
911 | * LCN_ENOENT. As long as the buffer is out | |
912 | * of bounds this will work fine. | |
913 | */ | |
914 | if (err == -ENOENT) { | |
915 | lcn = LCN_ENOENT; | |
916 | err = 0; | |
917 | goto rl_not_mapped_enoent; | |
918 | } | |
919 | } else | |
920 | err = -EIO; | |
921 | /* Failed to map the buffer, even after retrying. */ | |
922 | bh->b_blocknr = -1; | |
923 | ntfs_error(vol->sb, "Failed to write to inode 0x%lx, " | |
924 | "attribute type 0x%x, vcn 0x%llx, " | |
925 | "vcn offset 0x%x, because its " | |
926 | "location on disk could not be " | |
927 | "determined%s (error code %i).", | |
928 | ni->mft_no, ni->type, | |
929 | (unsigned long long)bh_cpos, | |
930 | (unsigned)bh_pos & | |
931 | vol->cluster_size_mask, | |
932 | is_retry ? " even after retrying" : "", | |
933 | err); | |
934 | break; | |
935 | } | |
936 | rl_not_mapped_enoent: | |
937 | /* | |
938 | * The buffer is in a hole or out of bounds. We need to fill | |
939 | * the hole, unless the buffer is in a cluster which is not | |
940 | * touched by the write, in which case we just leave the buffer | |
941 | * unmapped. This can only happen when the cluster size is | |
942 | * less than the page cache size. | |
943 | */ | |
944 | if (unlikely(vol->cluster_size < PAGE_SIZE)) { | |
945 | bh_cend = (bh_end + vol->cluster_size - 1) >> | |
946 | vol->cluster_size_bits; | |
947 | if ((bh_cend <= cpos || bh_cpos >= cend)) { | |
948 | bh->b_blocknr = -1; | |
949 | /* | |
950 | * If the buffer is uptodate we skip it. If it | |
951 | * is not but the page is uptodate, we can set | |
952 | * the buffer uptodate. If the page is not | |
953 | * uptodate, we can clear the buffer and set it | |
954 | * uptodate. Whether this is worthwhile is | |
955 | * debatable and this could be removed. | |
956 | */ | |
957 | if (PageUptodate(page)) { | |
958 | if (!buffer_uptodate(bh)) | |
959 | set_buffer_uptodate(bh); | |
960 | } else if (!buffer_uptodate(bh)) { | |
961 | zero_user(page, bh_offset(bh), | |
962 | blocksize); | |
963 | set_buffer_uptodate(bh); | |
964 | } | |
965 | continue; | |
966 | } | |
967 | } | |
968 | /* | |
969 | * Out of bounds buffer is invalid if it was not really out of | |
970 | * bounds. | |
971 | */ | |
972 | BUG_ON(lcn != LCN_HOLE); | |
973 | /* | |
974 | * We need the runlist locked for writing, so if it is locked | |
975 | * for reading relock it now and retry in case it changed | |
976 | * whilst we dropped the lock. | |
977 | */ | |
978 | BUG_ON(!rl); | |
979 | if (!rl_write_locked) { | |
980 | up_read(&ni->runlist.lock); | |
981 | down_write(&ni->runlist.lock); | |
982 | rl_write_locked = true; | |
983 | goto retry_remap; | |
984 | } | |
985 | /* Find the previous last allocated cluster. */ | |
986 | BUG_ON(rl->lcn != LCN_HOLE); | |
987 | lcn = -1; | |
988 | rl2 = rl; | |
989 | while (--rl2 >= ni->runlist.rl) { | |
990 | if (rl2->lcn >= 0) { | |
991 | lcn = rl2->lcn + rl2->length; | |
992 | break; | |
993 | } | |
994 | } | |
995 | rl2 = ntfs_cluster_alloc(vol, bh_cpos, 1, lcn, DATA_ZONE, | |
996 | false); | |
997 | if (IS_ERR(rl2)) { | |
998 | err = PTR_ERR(rl2); | |
999 | ntfs_debug("Failed to allocate cluster, error code %i.", | |
1000 | err); | |
1001 | break; | |
1002 | } | |
1003 | lcn = rl2->lcn; | |
1004 | rl = ntfs_runlists_merge(ni->runlist.rl, rl2); | |
1005 | if (IS_ERR(rl)) { | |
1006 | err = PTR_ERR(rl); | |
1007 | if (err != -ENOMEM) | |
1008 | err = -EIO; | |
1009 | if (ntfs_cluster_free_from_rl(vol, rl2)) { | |
1010 | ntfs_error(vol->sb, "Failed to release " | |
1011 | "allocated cluster in error " | |
1012 | "code path. Run chkdsk to " | |
1013 | "recover the lost cluster."); | |
1014 | NVolSetErrors(vol); | |
1015 | } | |
1016 | ntfs_free(rl2); | |
1017 | break; | |
1018 | } | |
1019 | ni->runlist.rl = rl; | |
1020 | status.runlist_merged = 1; | |
1021 | ntfs_debug("Allocated cluster, lcn 0x%llx.", | |
1022 | (unsigned long long)lcn); | |
1023 | /* Map and lock the mft record and get the attribute record. */ | |
1024 | if (!NInoAttr(ni)) | |
1025 | base_ni = ni; | |
1026 | else | |
1027 | base_ni = ni->ext.base_ntfs_ino; | |
1028 | m = map_mft_record(base_ni); | |
1029 | if (IS_ERR(m)) { | |
1030 | err = PTR_ERR(m); | |
1031 | break; | |
1032 | } | |
1033 | ctx = ntfs_attr_get_search_ctx(base_ni, m); | |
1034 | if (unlikely(!ctx)) { | |
1035 | err = -ENOMEM; | |
1036 | unmap_mft_record(base_ni); | |
1037 | break; | |
1038 | } | |
1039 | status.mft_attr_mapped = 1; | |
1040 | err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, | |
1041 | CASE_SENSITIVE, bh_cpos, NULL, 0, ctx); | |
1042 | if (unlikely(err)) { | |
1043 | if (err == -ENOENT) | |
1044 | err = -EIO; | |
1045 | break; | |
1046 | } | |
1047 | m = ctx->mrec; | |
1048 | a = ctx->attr; | |
1049 | /* | |
1050 | * Find the runlist element with which the attribute extent | |
1051 | * starts. Note, we cannot use the _attr_ version because we | |
1052 | * have mapped the mft record. That is ok because we know the | |
1053 | * runlist fragment must be mapped already to have ever gotten | |
1054 | * here, so we can just use the _rl_ version. | |
1055 | */ | |
1056 | vcn = sle64_to_cpu(a->data.non_resident.lowest_vcn); | |
1057 | rl2 = ntfs_rl_find_vcn_nolock(rl, vcn); | |
1058 | BUG_ON(!rl2); | |
1059 | BUG_ON(!rl2->length); | |
1060 | BUG_ON(rl2->lcn < LCN_HOLE); | |
1061 | highest_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn); | |
1062 | /* | |
1063 | * If @highest_vcn is zero, calculate the real highest_vcn | |
1064 | * (which can really be zero). | |
1065 | */ | |
1066 | if (!highest_vcn) | |
1067 | highest_vcn = (sle64_to_cpu( | |
1068 | a->data.non_resident.allocated_size) >> | |
1069 | vol->cluster_size_bits) - 1; | |
1070 | /* | |
1071 | * Determine the size of the mapping pairs array for the new | |
1072 | * extent, i.e. the old extent with the hole filled. | |
1073 | */ | |
1074 | mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, vcn, | |
1075 | highest_vcn); | |
1076 | if (unlikely(mp_size <= 0)) { | |
1077 | if (!(err = mp_size)) | |
1078 | err = -EIO; | |
1079 | ntfs_debug("Failed to get size for mapping pairs " | |
1080 | "array, error code %i.", err); | |
1081 | break; | |
1082 | } | |
1083 | /* | |
1084 | * Resize the attribute record to fit the new mapping pairs | |
1085 | * array. | |
1086 | */ | |
1087 | attr_rec_len = le32_to_cpu(a->length); | |
1088 | err = ntfs_attr_record_resize(m, a, mp_size + le16_to_cpu( | |
1089 | a->data.non_resident.mapping_pairs_offset)); | |
1090 | if (unlikely(err)) { | |
1091 | BUG_ON(err != -ENOSPC); | |
1092 | // TODO: Deal with this by using the current attribute | |
1093 | // and fill it with as much of the mapping pairs | |
1094 | // array as possible. Then loop over each attribute | |
1095 | // extent rewriting the mapping pairs arrays as we go | |
1096 | // along and if when we reach the end we have not | |
1097 | // enough space, try to resize the last attribute | |
1098 | // extent and if even that fails, add a new attribute | |
1099 | // extent. | |
1100 | // We could also try to resize at each step in the hope | |
1101 | // that we will not need to rewrite every single extent. | |
1102 | // Note, we may need to decompress some extents to fill | |
1103 | // the runlist as we are walking the extents... | |
1104 | ntfs_error(vol->sb, "Not enough space in the mft " | |
1105 | "record for the extended attribute " | |
1106 | "record. This case is not " | |
1107 | "implemented yet."); | |
1108 | err = -EOPNOTSUPP; | |
1109 | break ; | |
1110 | } | |
1111 | status.mp_rebuilt = 1; | |
1112 | /* | |
1113 | * Generate the mapping pairs array directly into the attribute | |
1114 | * record. | |
1115 | */ | |
1116 | err = ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu( | |
1117 | a->data.non_resident.mapping_pairs_offset), | |
1118 | mp_size, rl2, vcn, highest_vcn, NULL); | |
1119 | if (unlikely(err)) { | |
1120 | ntfs_error(vol->sb, "Cannot fill hole in inode 0x%lx, " | |
1121 | "attribute type 0x%x, because building " | |
1122 | "the mapping pairs failed with error " | |
1123 | "code %i.", vi->i_ino, | |
1124 | (unsigned)le32_to_cpu(ni->type), err); | |
1125 | err = -EIO; | |
1126 | break; | |
1127 | } | |
1128 | /* Update the highest_vcn but only if it was not set. */ | |
1129 | if (unlikely(!a->data.non_resident.highest_vcn)) | |
1130 | a->data.non_resident.highest_vcn = | |
1131 | cpu_to_sle64(highest_vcn); | |
1132 | /* | |
1133 | * If the attribute is sparse/compressed, update the compressed | |
1134 | * size in the ntfs_inode structure and the attribute record. | |
1135 | */ | |
1136 | if (likely(NInoSparse(ni) || NInoCompressed(ni))) { | |
1137 | /* | |
1138 | * If we are not in the first attribute extent, switch | |
1139 | * to it, but first ensure the changes will make it to | |
1140 | * disk later. | |
1141 | */ | |
1142 | if (a->data.non_resident.lowest_vcn) { | |
1143 | flush_dcache_mft_record_page(ctx->ntfs_ino); | |
1144 | mark_mft_record_dirty(ctx->ntfs_ino); | |
1145 | ntfs_attr_reinit_search_ctx(ctx); | |
1146 | err = ntfs_attr_lookup(ni->type, ni->name, | |
1147 | ni->name_len, CASE_SENSITIVE, | |
1148 | 0, NULL, 0, ctx); | |
1149 | if (unlikely(err)) { | |
1150 | status.attr_switched = 1; | |
1151 | break; | |
1152 | } | |
1153 | /* @m is not used any more so do not set it. */ | |
1154 | a = ctx->attr; | |
1155 | } | |
1156 | write_lock_irqsave(&ni->size_lock, flags); | |
1157 | ni->itype.compressed.size += vol->cluster_size; | |
1158 | a->data.non_resident.compressed_size = | |
1159 | cpu_to_sle64(ni->itype.compressed.size); | |
1160 | write_unlock_irqrestore(&ni->size_lock, flags); | |
1161 | } | |
1162 | /* Ensure the changes make it to disk. */ | |
1163 | flush_dcache_mft_record_page(ctx->ntfs_ino); | |
1164 | mark_mft_record_dirty(ctx->ntfs_ino); | |
1165 | ntfs_attr_put_search_ctx(ctx); | |
1166 | unmap_mft_record(base_ni); | |
1167 | /* Successfully filled the hole. */ | |
1168 | status.runlist_merged = 0; | |
1169 | status.mft_attr_mapped = 0; | |
1170 | status.mp_rebuilt = 0; | |
1171 | /* Setup the map cache and use that to deal with the buffer. */ | |
1172 | was_hole = true; | |
1173 | vcn = bh_cpos; | |
1174 | vcn_len = 1; | |
1175 | lcn_block = lcn << (vol->cluster_size_bits - blocksize_bits); | |
1176 | cdelta = 0; | |
1177 | /* | |
1178 | * If the number of remaining clusters in the @pages is smaller | |
1179 | * or equal to the number of cached clusters, unlock the | |
1180 | * runlist as the map cache will be used from now on. | |
1181 | */ | |
1182 | if (likely(vcn + vcn_len >= cend)) { | |
1183 | up_write(&ni->runlist.lock); | |
1184 | rl_write_locked = false; | |
1185 | rl = NULL; | |
1186 | } | |
1187 | goto map_buffer_cached; | |
1188 | } while (bh_pos += blocksize, (bh = bh->b_this_page) != head); | |
1189 | /* If there are no errors, do the next page. */ | |
1190 | if (likely(!err && ++u < nr_pages)) | |
1191 | goto do_next_page; | |
1192 | /* If there are no errors, release the runlist lock if we took it. */ | |
1193 | if (likely(!err)) { | |
1194 | if (unlikely(rl_write_locked)) { | |
1195 | up_write(&ni->runlist.lock); | |
1196 | rl_write_locked = false; | |
1197 | } else if (unlikely(rl)) | |
1198 | up_read(&ni->runlist.lock); | |
1199 | rl = NULL; | |
1200 | } | |
1201 | /* If we issued read requests, let them complete. */ | |
1202 | read_lock_irqsave(&ni->size_lock, flags); | |
1203 | initialized_size = ni->initialized_size; | |
1204 | read_unlock_irqrestore(&ni->size_lock, flags); | |
1205 | while (wait_bh > wait) { | |
1206 | bh = *--wait_bh; | |
1207 | wait_on_buffer(bh); | |
1208 | if (likely(buffer_uptodate(bh))) { | |
1209 | page = bh->b_page; | |
1210 | bh_pos = ((s64)page->index << PAGE_SHIFT) + | |
1211 | bh_offset(bh); | |
1212 | /* | |
1213 | * If the buffer overflows the initialized size, need | |
1214 | * to zero the overflowing region. | |
1215 | */ | |
1216 | if (unlikely(bh_pos + blocksize > initialized_size)) { | |
1217 | int ofs = 0; | |
1218 | ||
1219 | if (likely(bh_pos < initialized_size)) | |
1220 | ofs = initialized_size - bh_pos; | |
1221 | zero_user_segment(page, bh_offset(bh) + ofs, | |
1222 | blocksize); | |
1223 | } | |
1224 | } else /* if (unlikely(!buffer_uptodate(bh))) */ | |
1225 | err = -EIO; | |
1226 | } | |
1227 | if (likely(!err)) { | |
1228 | /* Clear buffer_new on all buffers. */ | |
1229 | u = 0; | |
1230 | do { | |
1231 | bh = head = page_buffers(pages[u]); | |
1232 | do { | |
1233 | if (buffer_new(bh)) | |
1234 | clear_buffer_new(bh); | |
1235 | } while ((bh = bh->b_this_page) != head); | |
1236 | } while (++u < nr_pages); | |
1237 | ntfs_debug("Done."); | |
1238 | return err; | |
1239 | } | |
1240 | if (status.attr_switched) { | |
1241 | /* Get back to the attribute extent we modified. */ | |
1242 | ntfs_attr_reinit_search_ctx(ctx); | |
1243 | if (ntfs_attr_lookup(ni->type, ni->name, ni->name_len, | |
1244 | CASE_SENSITIVE, bh_cpos, NULL, 0, ctx)) { | |
1245 | ntfs_error(vol->sb, "Failed to find required " | |
1246 | "attribute extent of attribute in " | |
1247 | "error code path. Run chkdsk to " | |
1248 | "recover."); | |
1249 | write_lock_irqsave(&ni->size_lock, flags); | |
1250 | ni->itype.compressed.size += vol->cluster_size; | |
1251 | write_unlock_irqrestore(&ni->size_lock, flags); | |
1252 | flush_dcache_mft_record_page(ctx->ntfs_ino); | |
1253 | mark_mft_record_dirty(ctx->ntfs_ino); | |
1254 | /* | |
1255 | * The only thing that is now wrong is the compressed | |
1256 | * size of the base attribute extent which chkdsk | |
1257 | * should be able to fix. | |
1258 | */ | |
1259 | NVolSetErrors(vol); | |
1260 | } else { | |
1261 | m = ctx->mrec; | |
1262 | a = ctx->attr; | |
1263 | status.attr_switched = 0; | |
1264 | } | |
1265 | } | |
1266 | /* | |
1267 | * If the runlist has been modified, need to restore it by punching a | |
1268 | * hole into it and we then need to deallocate the on-disk cluster as | |
1269 | * well. Note, we only modify the runlist if we are able to generate a | |
1270 | * new mapping pairs array, i.e. only when the mapped attribute extent | |
1271 | * is not switched. | |
1272 | */ | |
1273 | if (status.runlist_merged && !status.attr_switched) { | |
1274 | BUG_ON(!rl_write_locked); | |
1275 | /* Make the file cluster we allocated sparse in the runlist. */ | |
1276 | if (ntfs_rl_punch_nolock(vol, &ni->runlist, bh_cpos, 1)) { | |
1277 | ntfs_error(vol->sb, "Failed to punch hole into " | |
1278 | "attribute runlist in error code " | |
1279 | "path. Run chkdsk to recover the " | |
1280 | "lost cluster."); | |
1281 | NVolSetErrors(vol); | |
1282 | } else /* if (success) */ { | |
1283 | status.runlist_merged = 0; | |
1284 | /* | |
1285 | * Deallocate the on-disk cluster we allocated but only | |
1286 | * if we succeeded in punching its vcn out of the | |
1287 | * runlist. | |
1288 | */ | |
1289 | down_write(&vol->lcnbmp_lock); | |
1290 | if (ntfs_bitmap_clear_bit(vol->lcnbmp_ino, lcn)) { | |
1291 | ntfs_error(vol->sb, "Failed to release " | |
1292 | "allocated cluster in error " | |
1293 | "code path. Run chkdsk to " | |
1294 | "recover the lost cluster."); | |
1295 | NVolSetErrors(vol); | |
1296 | } | |
1297 | up_write(&vol->lcnbmp_lock); | |
1298 | } | |
1299 | } | |
1300 | /* | |
1301 | * Resize the attribute record to its old size and rebuild the mapping | |
1302 | * pairs array. Note, we only can do this if the runlist has been | |
1303 | * restored to its old state which also implies that the mapped | |
1304 | * attribute extent is not switched. | |
1305 | */ | |
1306 | if (status.mp_rebuilt && !status.runlist_merged) { | |
1307 | if (ntfs_attr_record_resize(m, a, attr_rec_len)) { | |
1308 | ntfs_error(vol->sb, "Failed to restore attribute " | |
1309 | "record in error code path. Run " | |
1310 | "chkdsk to recover."); | |
1311 | NVolSetErrors(vol); | |
1312 | } else /* if (success) */ { | |
1313 | if (ntfs_mapping_pairs_build(vol, (u8*)a + | |
1314 | le16_to_cpu(a->data.non_resident. | |
1315 | mapping_pairs_offset), attr_rec_len - | |
1316 | le16_to_cpu(a->data.non_resident. | |
1317 | mapping_pairs_offset), ni->runlist.rl, | |
1318 | vcn, highest_vcn, NULL)) { | |
1319 | ntfs_error(vol->sb, "Failed to restore " | |
1320 | "mapping pairs array in error " | |
1321 | "code path. Run chkdsk to " | |
1322 | "recover."); | |
1323 | NVolSetErrors(vol); | |
1324 | } | |
1325 | flush_dcache_mft_record_page(ctx->ntfs_ino); | |
1326 | mark_mft_record_dirty(ctx->ntfs_ino); | |
1327 | } | |
1328 | } | |
1329 | /* Release the mft record and the attribute. */ | |
1330 | if (status.mft_attr_mapped) { | |
1331 | ntfs_attr_put_search_ctx(ctx); | |
1332 | unmap_mft_record(base_ni); | |
1333 | } | |
1334 | /* Release the runlist lock. */ | |
1335 | if (rl_write_locked) | |
1336 | up_write(&ni->runlist.lock); | |
1337 | else if (rl) | |
1338 | up_read(&ni->runlist.lock); | |
1339 | /* | |
1340 | * Zero out any newly allocated blocks to avoid exposing stale data. | |
1341 | * If BH_New is set, we know that the block was newly allocated above | |
1342 | * and that it has not been fully zeroed and marked dirty yet. | |
1343 | */ | |
1344 | nr_pages = u; | |
1345 | u = 0; | |
1346 | end = bh_cpos << vol->cluster_size_bits; | |
1347 | do { | |
1348 | page = pages[u]; | |
1349 | bh = head = page_buffers(page); | |
1350 | do { | |
1351 | if (u == nr_pages && | |
1352 | ((s64)page->index << PAGE_SHIFT) + | |
1353 | bh_offset(bh) >= end) | |
1354 | break; | |
1355 | if (!buffer_new(bh)) | |
1356 | continue; | |
1357 | clear_buffer_new(bh); | |
1358 | if (!buffer_uptodate(bh)) { | |
1359 | if (PageUptodate(page)) | |
1360 | set_buffer_uptodate(bh); | |
1361 | else { | |
1362 | zero_user(page, bh_offset(bh), | |
1363 | blocksize); | |
1364 | set_buffer_uptodate(bh); | |
1365 | } | |
1366 | } | |
1367 | mark_buffer_dirty(bh); | |
1368 | } while ((bh = bh->b_this_page) != head); | |
1369 | } while (++u <= nr_pages); | |
1370 | ntfs_error(vol->sb, "Failed. Returning error code %i.", err); | |
1371 | return err; | |
1372 | } | |
1373 | ||
1374 | static inline void ntfs_flush_dcache_pages(struct page **pages, | |
1375 | unsigned nr_pages) | |
1376 | { | |
1377 | BUG_ON(!nr_pages); | |
1378 | /* | |
1379 | * Warning: Do not do the decrement at the same time as the call to | |
1380 | * flush_dcache_page() because it is a NULL macro on i386 and hence the | |
1381 | * decrement never happens so the loop never terminates. | |
1382 | */ | |
1383 | do { | |
1384 | --nr_pages; | |
1385 | flush_dcache_page(pages[nr_pages]); | |
1386 | } while (nr_pages > 0); | |
1387 | } | |
1388 | ||
1389 | /** | |
1390 | * ntfs_commit_pages_after_non_resident_write - commit the received data | |
1391 | * @pages: array of destination pages | |
1392 | * @nr_pages: number of pages in @pages | |
1393 | * @pos: byte position in file at which the write begins | |
1394 | * @bytes: number of bytes to be written | |
1395 | * | |
1396 | * See description of ntfs_commit_pages_after_write(), below. | |
1397 | */ | |
1398 | static inline int ntfs_commit_pages_after_non_resident_write( | |
1399 | struct page **pages, const unsigned nr_pages, | |
1400 | s64 pos, size_t bytes) | |
1401 | { | |
1402 | s64 end, initialized_size; | |
1403 | struct inode *vi; | |
1404 | ntfs_inode *ni, *base_ni; | |
1405 | struct buffer_head *bh, *head; | |
1406 | ntfs_attr_search_ctx *ctx; | |
1407 | MFT_RECORD *m; | |
1408 | ATTR_RECORD *a; | |
1409 | unsigned long flags; | |
1410 | unsigned blocksize, u; | |
1411 | int err; | |
1412 | ||
1413 | vi = pages[0]->mapping->host; | |
1414 | ni = NTFS_I(vi); | |
1415 | blocksize = vi->i_sb->s_blocksize; | |
1416 | end = pos + bytes; | |
1417 | u = 0; | |
1418 | do { | |
1419 | s64 bh_pos; | |
1420 | struct page *page; | |
1421 | bool partial; | |
1422 | ||
1423 | page = pages[u]; | |
1424 | bh_pos = (s64)page->index << PAGE_SHIFT; | |
1425 | bh = head = page_buffers(page); | |
1426 | partial = false; | |
1427 | do { | |
1428 | s64 bh_end; | |
1429 | ||
1430 | bh_end = bh_pos + blocksize; | |
1431 | if (bh_end <= pos || bh_pos >= end) { | |
1432 | if (!buffer_uptodate(bh)) | |
1433 | partial = true; | |
1434 | } else { | |
1435 | set_buffer_uptodate(bh); | |
1436 | mark_buffer_dirty(bh); | |
1437 | } | |
1438 | } while (bh_pos += blocksize, (bh = bh->b_this_page) != head); | |
1439 | /* | |
1440 | * If all buffers are now uptodate but the page is not, set the | |
1441 | * page uptodate. | |
1442 | */ | |
1443 | if (!partial && !PageUptodate(page)) | |
1444 | SetPageUptodate(page); | |
1445 | } while (++u < nr_pages); | |
1446 | /* | |
1447 | * Finally, if we do not need to update initialized_size or i_size we | |
1448 | * are finished. | |
1449 | */ | |
1450 | read_lock_irqsave(&ni->size_lock, flags); | |
1451 | initialized_size = ni->initialized_size; | |
1452 | read_unlock_irqrestore(&ni->size_lock, flags); | |
1453 | if (end <= initialized_size) { | |
1454 | ntfs_debug("Done."); | |
1455 | return 0; | |
1456 | } | |
1457 | /* | |
1458 | * Update initialized_size/i_size as appropriate, both in the inode and | |
1459 | * the mft record. | |
1460 | */ | |
1461 | if (!NInoAttr(ni)) | |
1462 | base_ni = ni; | |
1463 | else | |
1464 | base_ni = ni->ext.base_ntfs_ino; | |
1465 | /* Map, pin, and lock the mft record. */ | |
1466 | m = map_mft_record(base_ni); | |
1467 | if (IS_ERR(m)) { | |
1468 | err = PTR_ERR(m); | |
1469 | m = NULL; | |
1470 | ctx = NULL; | |
1471 | goto err_out; | |
1472 | } | |
1473 | BUG_ON(!NInoNonResident(ni)); | |
1474 | ctx = ntfs_attr_get_search_ctx(base_ni, m); | |
1475 | if (unlikely(!ctx)) { | |
1476 | err = -ENOMEM; | |
1477 | goto err_out; | |
1478 | } | |
1479 | err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, | |
1480 | CASE_SENSITIVE, 0, NULL, 0, ctx); | |
1481 | if (unlikely(err)) { | |
1482 | if (err == -ENOENT) | |
1483 | err = -EIO; | |
1484 | goto err_out; | |
1485 | } | |
1486 | a = ctx->attr; | |
1487 | BUG_ON(!a->non_resident); | |
1488 | write_lock_irqsave(&ni->size_lock, flags); | |
1489 | BUG_ON(end > ni->allocated_size); | |
1490 | ni->initialized_size = end; | |
1491 | a->data.non_resident.initialized_size = cpu_to_sle64(end); | |
1492 | if (end > i_size_read(vi)) { | |
1493 | i_size_write(vi, end); | |
1494 | a->data.non_resident.data_size = | |
1495 | a->data.non_resident.initialized_size; | |
1496 | } | |
1497 | write_unlock_irqrestore(&ni->size_lock, flags); | |
1498 | /* Mark the mft record dirty, so it gets written back. */ | |
1499 | flush_dcache_mft_record_page(ctx->ntfs_ino); | |
1500 | mark_mft_record_dirty(ctx->ntfs_ino); | |
1501 | ntfs_attr_put_search_ctx(ctx); | |
1502 | unmap_mft_record(base_ni); | |
1503 | ntfs_debug("Done."); | |
1504 | return 0; | |
1505 | err_out: | |
1506 | if (ctx) | |
1507 | ntfs_attr_put_search_ctx(ctx); | |
1508 | if (m) | |
1509 | unmap_mft_record(base_ni); | |
1510 | ntfs_error(vi->i_sb, "Failed to update initialized_size/i_size (error " | |
1511 | "code %i).", err); | |
1512 | if (err != -ENOMEM) | |
1513 | NVolSetErrors(ni->vol); | |
1514 | return err; | |
1515 | } | |
1516 | ||
1517 | /** | |
1518 | * ntfs_commit_pages_after_write - commit the received data | |
1519 | * @pages: array of destination pages | |
1520 | * @nr_pages: number of pages in @pages | |
1521 | * @pos: byte position in file at which the write begins | |
1522 | * @bytes: number of bytes to be written | |
1523 | * | |
1524 | * This is called from ntfs_file_buffered_write() with i_mutex held on the inode | |
1525 | * (@pages[0]->mapping->host). There are @nr_pages pages in @pages which are | |
1526 | * locked but not kmap()ped. The source data has already been copied into the | |
1527 | * @page. ntfs_prepare_pages_for_non_resident_write() has been called before | |
1528 | * the data was copied (for non-resident attributes only) and it returned | |
1529 | * success. | |
1530 | * | |
1531 | * Need to set uptodate and mark dirty all buffers within the boundary of the | |
1532 | * write. If all buffers in a page are uptodate we set the page uptodate, too. | |
1533 | * | |
1534 | * Setting the buffers dirty ensures that they get written out later when | |
1535 | * ntfs_writepage() is invoked by the VM. | |
1536 | * | |
1537 | * Finally, we need to update i_size and initialized_size as appropriate both | |
1538 | * in the inode and the mft record. | |
1539 | * | |
1540 | * This is modelled after fs/buffer.c::generic_commit_write(), which marks | |
1541 | * buffers uptodate and dirty, sets the page uptodate if all buffers in the | |
1542 | * page are uptodate, and updates i_size if the end of io is beyond i_size. In | |
1543 | * that case, it also marks the inode dirty. | |
1544 | * | |
1545 | * If things have gone as outlined in | |
1546 | * ntfs_prepare_pages_for_non_resident_write(), we do not need to do any page | |
1547 | * content modifications here for non-resident attributes. For resident | |
1548 | * attributes we need to do the uptodate bringing here which we combine with | |
1549 | * the copying into the mft record which means we save one atomic kmap. | |
1550 | * | |
1551 | * Return 0 on success or -errno on error. | |
1552 | */ | |
1553 | static int ntfs_commit_pages_after_write(struct page **pages, | |
1554 | const unsigned nr_pages, s64 pos, size_t bytes) | |
1555 | { | |
1556 | s64 end, initialized_size; | |
1557 | loff_t i_size; | |
1558 | struct inode *vi; | |
1559 | ntfs_inode *ni, *base_ni; | |
1560 | struct page *page; | |
1561 | ntfs_attr_search_ctx *ctx; | |
1562 | MFT_RECORD *m; | |
1563 | ATTR_RECORD *a; | |
1564 | char *kattr, *kaddr; | |
1565 | unsigned long flags; | |
1566 | u32 attr_len; | |
1567 | int err; | |
1568 | ||
1569 | BUG_ON(!nr_pages); | |
1570 | BUG_ON(!pages); | |
1571 | page = pages[0]; | |
1572 | BUG_ON(!page); | |
1573 | vi = page->mapping->host; | |
1574 | ni = NTFS_I(vi); | |
1575 | ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page " | |
1576 | "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.", | |
1577 | vi->i_ino, ni->type, page->index, nr_pages, | |
1578 | (long long)pos, bytes); | |
1579 | if (NInoNonResident(ni)) | |
1580 | return ntfs_commit_pages_after_non_resident_write(pages, | |
1581 | nr_pages, pos, bytes); | |
1582 | BUG_ON(nr_pages > 1); | |
1583 | /* | |
1584 | * Attribute is resident, implying it is not compressed, encrypted, or | |
1585 | * sparse. | |
1586 | */ | |
1587 | if (!NInoAttr(ni)) | |
1588 | base_ni = ni; | |
1589 | else | |
1590 | base_ni = ni->ext.base_ntfs_ino; | |
1591 | BUG_ON(NInoNonResident(ni)); | |
1592 | /* Map, pin, and lock the mft record. */ | |
1593 | m = map_mft_record(base_ni); | |
1594 | if (IS_ERR(m)) { | |
1595 | err = PTR_ERR(m); | |
1596 | m = NULL; | |
1597 | ctx = NULL; | |
1598 | goto err_out; | |
1599 | } | |
1600 | ctx = ntfs_attr_get_search_ctx(base_ni, m); | |
1601 | if (unlikely(!ctx)) { | |
1602 | err = -ENOMEM; | |
1603 | goto err_out; | |
1604 | } | |
1605 | err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, | |
1606 | CASE_SENSITIVE, 0, NULL, 0, ctx); | |
1607 | if (unlikely(err)) { | |
1608 | if (err == -ENOENT) | |
1609 | err = -EIO; | |
1610 | goto err_out; | |
1611 | } | |
1612 | a = ctx->attr; | |
1613 | BUG_ON(a->non_resident); | |
1614 | /* The total length of the attribute value. */ | |
1615 | attr_len = le32_to_cpu(a->data.resident.value_length); | |
1616 | i_size = i_size_read(vi); | |
1617 | BUG_ON(attr_len != i_size); | |
1618 | BUG_ON(pos > attr_len); | |
1619 | end = pos + bytes; | |
1620 | BUG_ON(end > le32_to_cpu(a->length) - | |
1621 | le16_to_cpu(a->data.resident.value_offset)); | |
1622 | kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset); | |
1623 | kaddr = kmap_atomic(page); | |
1624 | /* Copy the received data from the page to the mft record. */ | |
1625 | memcpy(kattr + pos, kaddr + pos, bytes); | |
1626 | /* Update the attribute length if necessary. */ | |
1627 | if (end > attr_len) { | |
1628 | attr_len = end; | |
1629 | a->data.resident.value_length = cpu_to_le32(attr_len); | |
1630 | } | |
1631 | /* | |
1632 | * If the page is not uptodate, bring the out of bounds area(s) | |
1633 | * uptodate by copying data from the mft record to the page. | |
1634 | */ | |
1635 | if (!PageUptodate(page)) { | |
1636 | if (pos > 0) | |
1637 | memcpy(kaddr, kattr, pos); | |
1638 | if (end < attr_len) | |
1639 | memcpy(kaddr + end, kattr + end, attr_len - end); | |
1640 | /* Zero the region outside the end of the attribute value. */ | |
1641 | memset(kaddr + attr_len, 0, PAGE_SIZE - attr_len); | |
1642 | flush_dcache_page(page); | |
1643 | SetPageUptodate(page); | |
1644 | } | |
1645 | kunmap_atomic(kaddr); | |
1646 | /* Update initialized_size/i_size if necessary. */ | |
1647 | read_lock_irqsave(&ni->size_lock, flags); | |
1648 | initialized_size = ni->initialized_size; | |
1649 | BUG_ON(end > ni->allocated_size); | |
1650 | read_unlock_irqrestore(&ni->size_lock, flags); | |
1651 | BUG_ON(initialized_size != i_size); | |
1652 | if (end > initialized_size) { | |
1653 | write_lock_irqsave(&ni->size_lock, flags); | |
1654 | ni->initialized_size = end; | |
1655 | i_size_write(vi, end); | |
1656 | write_unlock_irqrestore(&ni->size_lock, flags); | |
1657 | } | |
1658 | /* Mark the mft record dirty, so it gets written back. */ | |
1659 | flush_dcache_mft_record_page(ctx->ntfs_ino); | |
1660 | mark_mft_record_dirty(ctx->ntfs_ino); | |
1661 | ntfs_attr_put_search_ctx(ctx); | |
1662 | unmap_mft_record(base_ni); | |
1663 | ntfs_debug("Done."); | |
1664 | return 0; | |
1665 | err_out: | |
1666 | if (err == -ENOMEM) { | |
1667 | ntfs_warning(vi->i_sb, "Error allocating memory required to " | |
1668 | "commit the write."); | |
1669 | if (PageUptodate(page)) { | |
1670 | ntfs_warning(vi->i_sb, "Page is uptodate, setting " | |
1671 | "dirty so the write will be retried " | |
1672 | "later on by the VM."); | |
1673 | /* | |
1674 | * Put the page on mapping->dirty_pages, but leave its | |
1675 | * buffers' dirty state as-is. | |
1676 | */ | |
1677 | __set_page_dirty_nobuffers(page); | |
1678 | err = 0; | |
1679 | } else | |
1680 | ntfs_error(vi->i_sb, "Page is not uptodate. Written " | |
1681 | "data has been lost."); | |
1682 | } else { | |
1683 | ntfs_error(vi->i_sb, "Resident attribute commit write failed " | |
1684 | "with error %i.", err); | |
1685 | NVolSetErrors(ni->vol); | |
1686 | } | |
1687 | if (ctx) | |
1688 | ntfs_attr_put_search_ctx(ctx); | |
1689 | if (m) | |
1690 | unmap_mft_record(base_ni); | |
1691 | return err; | |
1692 | } | |
1693 | ||
1694 | /* | |
1695 | * Copy as much as we can into the pages and return the number of bytes which | |
1696 | * were successfully copied. If a fault is encountered then clear the pages | |
1697 | * out to (ofs + bytes) and return the number of bytes which were copied. | |
1698 | */ | |
1699 | static size_t ntfs_copy_from_user_iter(struct page **pages, unsigned nr_pages, | |
1700 | unsigned ofs, struct iov_iter *i, size_t bytes) | |
1701 | { | |
1702 | struct page **last_page = pages + nr_pages; | |
1703 | size_t total = 0; | |
1704 | struct iov_iter data = *i; | |
1705 | unsigned len, copied; | |
1706 | ||
1707 | do { | |
1708 | len = PAGE_SIZE - ofs; | |
1709 | if (len > bytes) | |
1710 | len = bytes; | |
1711 | copied = iov_iter_copy_from_user_atomic(*pages, &data, ofs, | |
1712 | len); | |
1713 | total += copied; | |
1714 | bytes -= copied; | |
1715 | if (!bytes) | |
1716 | break; | |
1717 | iov_iter_advance(&data, copied); | |
1718 | if (copied < len) | |
1719 | goto err; | |
1720 | ofs = 0; | |
1721 | } while (++pages < last_page); | |
1722 | out: | |
1723 | return total; | |
1724 | err: | |
1725 | /* Zero the rest of the target like __copy_from_user(). */ | |
1726 | len = PAGE_SIZE - copied; | |
1727 | do { | |
1728 | if (len > bytes) | |
1729 | len = bytes; | |
1730 | zero_user(*pages, copied, len); | |
1731 | bytes -= len; | |
1732 | copied = 0; | |
1733 | len = PAGE_SIZE; | |
1734 | } while (++pages < last_page); | |
1735 | goto out; | |
1736 | } | |
1737 | ||
1738 | /** | |
1739 | * ntfs_perform_write - perform buffered write to a file | |
1740 | * @file: file to write to | |
1741 | * @i: iov_iter with data to write | |
1742 | * @pos: byte offset in file at which to begin writing to | |
1743 | */ | |
1744 | static ssize_t ntfs_perform_write(struct file *file, struct iov_iter *i, | |
1745 | loff_t pos) | |
1746 | { | |
1747 | struct address_space *mapping = file->f_mapping; | |
1748 | struct inode *vi = mapping->host; | |
1749 | ntfs_inode *ni = NTFS_I(vi); | |
1750 | ntfs_volume *vol = ni->vol; | |
1751 | struct page *pages[NTFS_MAX_PAGES_PER_CLUSTER]; | |
1752 | struct page *cached_page = NULL; | |
1753 | VCN last_vcn; | |
1754 | LCN lcn; | |
1755 | size_t bytes; | |
1756 | ssize_t status, written = 0; | |
1757 | unsigned nr_pages; | |
1758 | ||
1759 | ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, pos " | |
1760 | "0x%llx, count 0x%lx.", vi->i_ino, | |
1761 | (unsigned)le32_to_cpu(ni->type), | |
1762 | (unsigned long long)pos, | |
1763 | (unsigned long)iov_iter_count(i)); | |
1764 | /* | |
1765 | * If a previous ntfs_truncate() failed, repeat it and abort if it | |
1766 | * fails again. | |
1767 | */ | |
1768 | if (unlikely(NInoTruncateFailed(ni))) { | |
1769 | int err; | |
1770 | ||
1771 | inode_dio_wait(vi); | |
1772 | err = ntfs_truncate(vi); | |
1773 | if (err || NInoTruncateFailed(ni)) { | |
1774 | if (!err) | |
1775 | err = -EIO; | |
1776 | ntfs_error(vol->sb, "Cannot perform write to inode " | |
1777 | "0x%lx, attribute type 0x%x, because " | |
1778 | "ntfs_truncate() failed (error code " | |
1779 | "%i).", vi->i_ino, | |
1780 | (unsigned)le32_to_cpu(ni->type), err); | |
1781 | return err; | |
1782 | } | |
1783 | } | |
1784 | /* | |
1785 | * Determine the number of pages per cluster for non-resident | |
1786 | * attributes. | |
1787 | */ | |
1788 | nr_pages = 1; | |
1789 | if (vol->cluster_size > PAGE_SIZE && NInoNonResident(ni)) | |
1790 | nr_pages = vol->cluster_size >> PAGE_SHIFT; | |
1791 | last_vcn = -1; | |
1792 | do { | |
1793 | VCN vcn; | |
1794 | pgoff_t idx, start_idx; | |
1795 | unsigned ofs, do_pages, u; | |
1796 | size_t copied; | |
1797 | ||
1798 | start_idx = idx = pos >> PAGE_SHIFT; | |
1799 | ofs = pos & ~PAGE_MASK; | |
1800 | bytes = PAGE_SIZE - ofs; | |
1801 | do_pages = 1; | |
1802 | if (nr_pages > 1) { | |
1803 | vcn = pos >> vol->cluster_size_bits; | |
1804 | if (vcn != last_vcn) { | |
1805 | last_vcn = vcn; | |
1806 | /* | |
1807 | * Get the lcn of the vcn the write is in. If | |
1808 | * it is a hole, need to lock down all pages in | |
1809 | * the cluster. | |
1810 | */ | |
1811 | down_read(&ni->runlist.lock); | |
1812 | lcn = ntfs_attr_vcn_to_lcn_nolock(ni, pos >> | |
1813 | vol->cluster_size_bits, false); | |
1814 | up_read(&ni->runlist.lock); | |
1815 | if (unlikely(lcn < LCN_HOLE)) { | |
1816 | if (lcn == LCN_ENOMEM) | |
1817 | status = -ENOMEM; | |
1818 | else { | |
1819 | status = -EIO; | |
1820 | ntfs_error(vol->sb, "Cannot " | |
1821 | "perform write to " | |
1822 | "inode 0x%lx, " | |
1823 | "attribute type 0x%x, " | |
1824 | "because the attribute " | |
1825 | "is corrupt.", | |
1826 | vi->i_ino, (unsigned) | |
1827 | le32_to_cpu(ni->type)); | |
1828 | } | |
1829 | break; | |
1830 | } | |
1831 | if (lcn == LCN_HOLE) { | |
1832 | start_idx = (pos & ~(s64) | |
1833 | vol->cluster_size_mask) | |
1834 | >> PAGE_SHIFT; | |
1835 | bytes = vol->cluster_size - (pos & | |
1836 | vol->cluster_size_mask); | |
1837 | do_pages = nr_pages; | |
1838 | } | |
1839 | } | |
1840 | } | |
1841 | if (bytes > iov_iter_count(i)) | |
1842 | bytes = iov_iter_count(i); | |
1843 | again: | |
1844 | /* | |
1845 | * Bring in the user page(s) that we will copy from _first_. | |
1846 | * Otherwise there is a nasty deadlock on copying from the same | |
1847 | * page(s) as we are writing to, without it/them being marked | |
1848 | * up-to-date. Note, at present there is nothing to stop the | |
1849 | * pages being swapped out between us bringing them into memory | |
1850 | * and doing the actual copying. | |
1851 | */ | |
1852 | if (unlikely(iov_iter_fault_in_readable(i, bytes))) { | |
1853 | status = -EFAULT; | |
1854 | break; | |
1855 | } | |
1856 | /* Get and lock @do_pages starting at index @start_idx. */ | |
1857 | status = __ntfs_grab_cache_pages(mapping, start_idx, do_pages, | |
1858 | pages, &cached_page); | |
1859 | if (unlikely(status)) | |
1860 | break; | |
1861 | /* | |
1862 | * For non-resident attributes, we need to fill any holes with | |
1863 | * actual clusters and ensure all bufferes are mapped. We also | |
1864 | * need to bring uptodate any buffers that are only partially | |
1865 | * being written to. | |
1866 | */ | |
1867 | if (NInoNonResident(ni)) { | |
1868 | status = ntfs_prepare_pages_for_non_resident_write( | |
1869 | pages, do_pages, pos, bytes); | |
1870 | if (unlikely(status)) { | |
1871 | do { | |
1872 | unlock_page(pages[--do_pages]); | |
1873 | put_page(pages[do_pages]); | |
1874 | } while (do_pages); | |
1875 | break; | |
1876 | } | |
1877 | } | |
1878 | u = (pos >> PAGE_SHIFT) - pages[0]->index; | |
1879 | copied = ntfs_copy_from_user_iter(pages + u, do_pages - u, ofs, | |
1880 | i, bytes); | |
1881 | ntfs_flush_dcache_pages(pages + u, do_pages - u); | |
1882 | status = 0; | |
1883 | if (likely(copied == bytes)) { | |
1884 | status = ntfs_commit_pages_after_write(pages, do_pages, | |
1885 | pos, bytes); | |
1886 | if (!status) | |
1887 | status = bytes; | |
1888 | } | |
1889 | do { | |
1890 | unlock_page(pages[--do_pages]); | |
1891 | put_page(pages[do_pages]); | |
1892 | } while (do_pages); | |
1893 | if (unlikely(status < 0)) | |
1894 | break; | |
1895 | copied = status; | |
1896 | cond_resched(); | |
1897 | if (unlikely(!copied)) { | |
1898 | size_t sc; | |
1899 | ||
1900 | /* | |
1901 | * We failed to copy anything. Fall back to single | |
1902 | * segment length write. | |
1903 | * | |
1904 | * This is needed to avoid possible livelock in the | |
1905 | * case that all segments in the iov cannot be copied | |
1906 | * at once without a pagefault. | |
1907 | */ | |
1908 | sc = iov_iter_single_seg_count(i); | |
1909 | if (bytes > sc) | |
1910 | bytes = sc; | |
1911 | goto again; | |
1912 | } | |
1913 | iov_iter_advance(i, copied); | |
1914 | pos += copied; | |
1915 | written += copied; | |
1916 | balance_dirty_pages_ratelimited(mapping); | |
1917 | if (fatal_signal_pending(current)) { | |
1918 | status = -EINTR; | |
1919 | break; | |
1920 | } | |
1921 | } while (iov_iter_count(i)); | |
1922 | if (cached_page) | |
1923 | put_page(cached_page); | |
1924 | ntfs_debug("Done. Returning %s (written 0x%lx, status %li).", | |
1925 | written ? "written" : "status", (unsigned long)written, | |
1926 | (long)status); | |
1927 | return written ? written : status; | |
1928 | } | |
1929 | ||
1930 | /** | |
1931 | * ntfs_file_write_iter - simple wrapper for ntfs_file_write_iter_nolock() | |
1932 | * @iocb: IO state structure | |
1933 | * @from: iov_iter with data to write | |
1934 | * | |
1935 | * Basically the same as generic_file_write_iter() except that it ends up | |
1936 | * up calling ntfs_perform_write() instead of generic_perform_write() and that | |
1937 | * O_DIRECT is not implemented. | |
1938 | */ | |
1939 | static ssize_t ntfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) | |
1940 | { | |
1941 | struct file *file = iocb->ki_filp; | |
1942 | struct inode *vi = file_inode(file); | |
1943 | ssize_t written = 0; | |
1944 | ssize_t err; | |
1945 | ||
1946 | inode_lock(vi); | |
1947 | /* We can write back this queue in page reclaim. */ | |
1948 | current->backing_dev_info = inode_to_bdi(vi); | |
1949 | err = ntfs_prepare_file_for_write(iocb, from); | |
1950 | if (iov_iter_count(from) && !err) | |
1951 | written = ntfs_perform_write(file, from, iocb->ki_pos); | |
1952 | current->backing_dev_info = NULL; | |
1953 | inode_unlock(vi); | |
1954 | iocb->ki_pos += written; | |
1955 | if (likely(written > 0)) | |
1956 | written = generic_write_sync(iocb, written); | |
1957 | return written ? written : err; | |
1958 | } | |
1959 | ||
1960 | /** | |
1961 | * ntfs_file_fsync - sync a file to disk | |
1962 | * @filp: file to be synced | |
1963 | * @datasync: if non-zero only flush user data and not metadata | |
1964 | * | |
1965 | * Data integrity sync of a file to disk. Used for fsync, fdatasync, and msync | |
1966 | * system calls. This function is inspired by fs/buffer.c::file_fsync(). | |
1967 | * | |
1968 | * If @datasync is false, write the mft record and all associated extent mft | |
1969 | * records as well as the $DATA attribute and then sync the block device. | |
1970 | * | |
1971 | * If @datasync is true and the attribute is non-resident, we skip the writing | |
1972 | * of the mft record and all associated extent mft records (this might still | |
1973 | * happen due to the write_inode_now() call). | |
1974 | * | |
1975 | * Also, if @datasync is true, we do not wait on the inode to be written out | |
1976 | * but we always wait on the page cache pages to be written out. | |
1977 | * | |
1978 | * Locking: Caller must hold i_mutex on the inode. | |
1979 | * | |
1980 | * TODO: We should probably also write all attribute/index inodes associated | |
1981 | * with this inode but since we have no simple way of getting to them we ignore | |
1982 | * this problem for now. | |
1983 | */ | |
1984 | static int ntfs_file_fsync(struct file *filp, loff_t start, loff_t end, | |
1985 | int datasync) | |
1986 | { | |
1987 | struct inode *vi = filp->f_mapping->host; | |
1988 | int err, ret = 0; | |
1989 | ||
1990 | ntfs_debug("Entering for inode 0x%lx.", vi->i_ino); | |
1991 | ||
1992 | err = filemap_write_and_wait_range(vi->i_mapping, start, end); | |
1993 | if (err) | |
1994 | return err; | |
1995 | inode_lock(vi); | |
1996 | ||
1997 | BUG_ON(S_ISDIR(vi->i_mode)); | |
1998 | if (!datasync || !NInoNonResident(NTFS_I(vi))) | |
1999 | ret = __ntfs_write_inode(vi, 1); | |
2000 | write_inode_now(vi, !datasync); | |
2001 | /* | |
2002 | * NOTE: If we were to use mapping->private_list (see ext2 and | |
2003 | * fs/buffer.c) for dirty blocks then we could optimize the below to be | |
2004 | * sync_mapping_buffers(vi->i_mapping). | |
2005 | */ | |
2006 | err = sync_blockdev(vi->i_sb->s_bdev); | |
2007 | if (unlikely(err && !ret)) | |
2008 | ret = err; | |
2009 | if (likely(!ret)) | |
2010 | ntfs_debug("Done."); | |
2011 | else | |
2012 | ntfs_warning(vi->i_sb, "Failed to f%ssync inode 0x%lx. Error " | |
2013 | "%u.", datasync ? "data" : "", vi->i_ino, -ret); | |
2014 | inode_unlock(vi); | |
2015 | return ret; | |
2016 | } | |
2017 | ||
2018 | #endif /* NTFS_RW */ | |
2019 | ||
2020 | const struct file_operations ntfs_file_ops = { | |
2021 | .llseek = generic_file_llseek, | |
2022 | .read_iter = generic_file_read_iter, | |
2023 | #ifdef NTFS_RW | |
2024 | .write_iter = ntfs_file_write_iter, | |
2025 | .fsync = ntfs_file_fsync, | |
2026 | #endif /* NTFS_RW */ | |
2027 | .mmap = generic_file_mmap, | |
2028 | .open = ntfs_file_open, | |
2029 | .splice_read = generic_file_splice_read, | |
2030 | }; | |
2031 | ||
2032 | const struct inode_operations ntfs_file_inode_ops = { | |
2033 | #ifdef NTFS_RW | |
2034 | .setattr = ntfs_setattr, | |
2035 | #endif /* NTFS_RW */ | |
2036 | }; | |
2037 | ||
2038 | const struct file_operations ntfs_empty_file_ops = {}; | |
2039 | ||
2040 | const struct inode_operations ntfs_empty_inode_ops = {}; |