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1 | /** |
2 | * aops.c - NTFS kernel address space operations and page cache handling. |
3 | * Part of the Linux-NTFS project. |
4 | * |
5 | * Copyright (c) 2001-2007 Anton Altaparmakov |
6 | * Copyright (c) 2002 Richard Russon |
7 | * |
8 | * This program/include file is free software; you can redistribute it and/or |
9 | * modify it under the terms of the GNU General Public License as published |
10 | * by the Free Software Foundation; either version 2 of the License, or |
11 | * (at your option) any later version. |
12 | * |
13 | * This program/include file is distributed in the hope that it will be |
14 | * useful, but WITHOUT ANY WARRANTY; without even the implied warranty |
15 | * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
16 | * GNU General Public License for more details. |
17 | * |
18 | * You should have received a copy of the GNU General Public License |
19 | * along with this program (in the main directory of the Linux-NTFS |
20 | * distribution in the file COPYING); if not, write to the Free Software |
21 | * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
22 | */ |
23 | |
24 | #include <linux/errno.h> |
25 | #include <linux/fs.h> |
26 | #include <linux/gfp.h> |
27 | #include <linux/mm.h> |
28 | #include <linux/pagemap.h> |
29 | #include <linux/swap.h> |
30 | #include <linux/buffer_head.h> |
31 | #include <linux/writeback.h> |
32 | #include <linux/bit_spinlock.h> |
33 | |
34 | #include "aops.h" |
35 | #include "attrib.h" |
36 | #include "debug.h" |
37 | #include "inode.h" |
38 | #include "mft.h" |
39 | #include "runlist.h" |
40 | #include "types.h" |
41 | #include "ntfs.h" |
42 | |
43 | /** |
44 | * ntfs_end_buffer_async_read - async io completion for reading attributes |
45 | * @bh: buffer head on which io is completed |
46 | * @uptodate: whether @bh is now uptodate or not |
47 | * |
48 | * Asynchronous I/O completion handler for reading pages belonging to the |
49 | * attribute address space of an inode. The inodes can either be files or |
50 | * directories or they can be fake inodes describing some attribute. |
51 | * |
52 | * If NInoMstProtected(), perform the post read mst fixups when all IO on the |
53 | * page has been completed and mark the page uptodate or set the error bit on |
54 | * the page. To determine the size of the records that need fixing up, we |
55 | * cheat a little bit by setting the index_block_size in ntfs_inode to the ntfs |
56 | * record size, and index_block_size_bits, to the log(base 2) of the ntfs |
57 | * record size. |
58 | */ |
59 | static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate) |
60 | { |
61 | unsigned long flags; |
62 | struct buffer_head *first, *tmp; |
63 | struct page *page; |
64 | struct inode *vi; |
65 | ntfs_inode *ni; |
66 | int page_uptodate = 1; |
67 | |
68 | page = bh->b_page; |
69 | vi = page->mapping->host; |
70 | ni = NTFS_I(vi); |
71 | |
72 | if (likely(uptodate)) { |
73 | loff_t i_size; |
74 | s64 file_ofs, init_size; |
75 | |
76 | set_buffer_uptodate(bh); |
77 | |
78 | file_ofs = ((s64)page->index << PAGE_CACHE_SHIFT) + |
79 | bh_offset(bh); |
80 | read_lock_irqsave(&ni->size_lock, flags); |
81 | init_size = ni->initialized_size; |
82 | i_size = i_size_read(vi); |
83 | read_unlock_irqrestore(&ni->size_lock, flags); |
84 | if (unlikely(init_size > i_size)) { |
85 | /* Race with shrinking truncate. */ |
86 | init_size = i_size; |
87 | } |
88 | /* Check for the current buffer head overflowing. */ |
89 | if (unlikely(file_ofs + bh->b_size > init_size)) { |
90 | int ofs; |
91 | void *kaddr; |
92 | |
93 | ofs = 0; |
94 | if (file_ofs < init_size) |
95 | ofs = init_size - file_ofs; |
96 | local_irq_save(flags); |
97 | kaddr = kmap_atomic(page, KM_BIO_SRC_IRQ); |
98 | memset(kaddr + bh_offset(bh) + ofs, 0, |
99 | bh->b_size - ofs); |
100 | flush_dcache_page(page); |
101 | kunmap_atomic(kaddr, KM_BIO_SRC_IRQ); |
102 | local_irq_restore(flags); |
103 | } |
104 | } else { |
105 | clear_buffer_uptodate(bh); |
106 | SetPageError(page); |
107 | ntfs_error(ni->vol->sb, "Buffer I/O error, logical block " |
108 | "0x%llx.", (unsigned long long)bh->b_blocknr); |
109 | } |
110 | first = page_buffers(page); |
111 | local_irq_save(flags); |
112 | bit_spin_lock(BH_Uptodate_Lock, &first->b_state); |
113 | clear_buffer_async_read(bh); |
114 | unlock_buffer(bh); |
115 | tmp = bh; |
116 | do { |
117 | if (!buffer_uptodate(tmp)) |
118 | page_uptodate = 0; |
119 | if (buffer_async_read(tmp)) { |
120 | if (likely(buffer_locked(tmp))) |
121 | goto still_busy; |
122 | /* Async buffers must be locked. */ |
123 | BUG(); |
124 | } |
125 | tmp = tmp->b_this_page; |
126 | } while (tmp != bh); |
127 | bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); |
128 | local_irq_restore(flags); |
129 | /* |
130 | * If none of the buffers had errors then we can set the page uptodate, |
131 | * but we first have to perform the post read mst fixups, if the |
132 | * attribute is mst protected, i.e. if NInoMstProteced(ni) is true. |
133 | * Note we ignore fixup errors as those are detected when |
134 | * map_mft_record() is called which gives us per record granularity |
135 | * rather than per page granularity. |
136 | */ |
137 | if (!NInoMstProtected(ni)) { |
138 | if (likely(page_uptodate && !PageError(page))) |
139 | SetPageUptodate(page); |
140 | } else { |
141 | u8 *kaddr; |
142 | unsigned int i, recs; |
143 | u32 rec_size; |
144 | |
145 | rec_size = ni->itype.index.block_size; |
146 | recs = PAGE_CACHE_SIZE / rec_size; |
147 | /* Should have been verified before we got here... */ |
148 | BUG_ON(!recs); |
149 | local_irq_save(flags); |
150 | kaddr = kmap_atomic(page, KM_BIO_SRC_IRQ); |
151 | for (i = 0; i < recs; i++) |
152 | post_read_mst_fixup((NTFS_RECORD*)(kaddr + |
153 | i * rec_size), rec_size); |
154 | kunmap_atomic(kaddr, KM_BIO_SRC_IRQ); |
155 | local_irq_restore(flags); |
156 | flush_dcache_page(page); |
157 | if (likely(page_uptodate && !PageError(page))) |
158 | SetPageUptodate(page); |
159 | } |
160 | unlock_page(page); |
161 | return; |
162 | still_busy: |
163 | bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); |
164 | local_irq_restore(flags); |
165 | return; |
166 | } |
167 | |
168 | /** |
169 | * ntfs_read_block - fill a @page of an address space with data |
170 | * @page: page cache page to fill with data |
171 | * |
172 | * Fill the page @page of the address space belonging to the @page->host inode. |
173 | * We read each buffer asynchronously and when all buffers are read in, our io |
174 | * completion handler ntfs_end_buffer_read_async(), if required, automatically |
175 | * applies the mst fixups to the page before finally marking it uptodate and |
176 | * unlocking it. |
177 | * |
178 | * We only enforce allocated_size limit because i_size is checked for in |
179 | * generic_file_read(). |
180 | * |
181 | * Return 0 on success and -errno on error. |
182 | * |
183 | * Contains an adapted version of fs/buffer.c::block_read_full_page(). |
184 | */ |
185 | static int ntfs_read_block(struct page *page) |
186 | { |
187 | loff_t i_size; |
188 | VCN vcn; |
189 | LCN lcn; |
190 | s64 init_size; |
191 | struct inode *vi; |
192 | ntfs_inode *ni; |
193 | ntfs_volume *vol; |
194 | runlist_element *rl; |
195 | struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE]; |
196 | sector_t iblock, lblock, zblock; |
197 | unsigned long flags; |
198 | unsigned int blocksize, vcn_ofs; |
199 | int i, nr; |
200 | unsigned char blocksize_bits; |
201 | |
202 | vi = page->mapping->host; |
203 | ni = NTFS_I(vi); |
204 | vol = ni->vol; |
205 | |
206 | /* $MFT/$DATA must have its complete runlist in memory at all times. */ |
207 | BUG_ON(!ni->runlist.rl && !ni->mft_no && !NInoAttr(ni)); |
208 | |
209 | blocksize = vol->sb->s_blocksize; |
210 | blocksize_bits = vol->sb->s_blocksize_bits; |
211 | |
212 | if (!page_has_buffers(page)) { |
213 | create_empty_buffers(page, blocksize, 0); |
214 | if (unlikely(!page_has_buffers(page))) { |
215 | unlock_page(page); |
216 | return -ENOMEM; |
217 | } |
218 | } |
219 | bh = head = page_buffers(page); |
220 | BUG_ON(!bh); |
221 | |
222 | /* |
223 | * We may be racing with truncate. To avoid some of the problems we |
224 | * now take a snapshot of the various sizes and use those for the whole |
225 | * of the function. In case of an extending truncate it just means we |
226 | * may leave some buffers unmapped which are now allocated. This is |
227 | * not a problem since these buffers will just get mapped when a write |
228 | * occurs. In case of a shrinking truncate, we will detect this later |
229 | * on due to the runlist being incomplete and if the page is being |
230 | * fully truncated, truncate will throw it away as soon as we unlock |
231 | * it so no need to worry what we do with it. |
232 | */ |
233 | iblock = (s64)page->index << (PAGE_CACHE_SHIFT - blocksize_bits); |
234 | read_lock_irqsave(&ni->size_lock, flags); |
235 | lblock = (ni->allocated_size + blocksize - 1) >> blocksize_bits; |
236 | init_size = ni->initialized_size; |
237 | i_size = i_size_read(vi); |
238 | read_unlock_irqrestore(&ni->size_lock, flags); |
239 | if (unlikely(init_size > i_size)) { |
240 | /* Race with shrinking truncate. */ |
241 | init_size = i_size; |
242 | } |
243 | zblock = (init_size + blocksize - 1) >> blocksize_bits; |
244 | |
245 | /* Loop through all the buffers in the page. */ |
246 | rl = NULL; |
247 | nr = i = 0; |
248 | do { |
249 | int err = 0; |
250 | |
251 | if (unlikely(buffer_uptodate(bh))) |
252 | continue; |
253 | if (unlikely(buffer_mapped(bh))) { |
254 | arr[nr++] = bh; |
255 | continue; |
256 | } |
257 | bh->b_bdev = vol->sb->s_bdev; |
258 | /* Is the block within the allowed limits? */ |
259 | if (iblock < lblock) { |
260 | bool is_retry = false; |
261 | |
262 | /* Convert iblock into corresponding vcn and offset. */ |
263 | vcn = (VCN)iblock << blocksize_bits >> |
264 | vol->cluster_size_bits; |
265 | vcn_ofs = ((VCN)iblock << blocksize_bits) & |
266 | vol->cluster_size_mask; |
267 | if (!rl) { |
268 | lock_retry_remap: |
269 | down_read(&ni->runlist.lock); |
270 | rl = ni->runlist.rl; |
271 | } |
272 | if (likely(rl != NULL)) { |
273 | /* Seek to element containing target vcn. */ |
274 | while (rl->length && rl[1].vcn <= vcn) |
275 | rl++; |
276 | lcn = ntfs_rl_vcn_to_lcn(rl, vcn); |
277 | } else |
278 | lcn = LCN_RL_NOT_MAPPED; |
279 | /* Successful remap. */ |
280 | if (lcn >= 0) { |
281 | /* Setup buffer head to correct block. */ |
282 | bh->b_blocknr = ((lcn << vol->cluster_size_bits) |
283 | + vcn_ofs) >> blocksize_bits; |
284 | set_buffer_mapped(bh); |
285 | /* Only read initialized data blocks. */ |
286 | if (iblock < zblock) { |
287 | arr[nr++] = bh; |
288 | continue; |
289 | } |
290 | /* Fully non-initialized data block, zero it. */ |
291 | goto handle_zblock; |
292 | } |
293 | /* It is a hole, need to zero it. */ |
294 | if (lcn == LCN_HOLE) |
295 | goto handle_hole; |
296 | /* If first try and runlist unmapped, map and retry. */ |
297 | if (!is_retry && lcn == LCN_RL_NOT_MAPPED) { |
298 | is_retry = true; |
299 | /* |
300 | * Attempt to map runlist, dropping lock for |
301 | * the duration. |
302 | */ |
303 | up_read(&ni->runlist.lock); |
304 | err = ntfs_map_runlist(ni, vcn); |
305 | if (likely(!err)) |
306 | goto lock_retry_remap; |
307 | rl = NULL; |
308 | } else if (!rl) |
309 | up_read(&ni->runlist.lock); |
310 | /* |
311 | * If buffer is outside the runlist, treat it as a |
312 | * hole. This can happen due to concurrent truncate |
313 | * for example. |
314 | */ |
315 | if (err == -ENOENT || lcn == LCN_ENOENT) { |
316 | err = 0; |
317 | goto handle_hole; |
318 | } |
319 | /* Hard error, zero out region. */ |
320 | if (!err) |
321 | err = -EIO; |
322 | bh->b_blocknr = -1; |
323 | SetPageError(page); |
324 | ntfs_error(vol->sb, "Failed to read from inode 0x%lx, " |
325 | "attribute type 0x%x, vcn 0x%llx, " |
326 | "offset 0x%x because its location on " |
327 | "disk could not be determined%s " |
328 | "(error code %i).", ni->mft_no, |
329 | ni->type, (unsigned long long)vcn, |
330 | vcn_ofs, is_retry ? " even after " |
331 | "retrying" : "", err); |
332 | } |
333 | /* |
334 | * Either iblock was outside lblock limits or |
335 | * ntfs_rl_vcn_to_lcn() returned error. Just zero that portion |
336 | * of the page and set the buffer uptodate. |
337 | */ |
338 | handle_hole: |
339 | bh->b_blocknr = -1UL; |
340 | clear_buffer_mapped(bh); |
341 | handle_zblock: |
342 | zero_user(page, i * blocksize, blocksize); |
343 | if (likely(!err)) |
344 | set_buffer_uptodate(bh); |
345 | } while (i++, iblock++, (bh = bh->b_this_page) != head); |
346 | |
347 | /* Release the lock if we took it. */ |
348 | if (rl) |
349 | up_read(&ni->runlist.lock); |
350 | |
351 | /* Check we have at least one buffer ready for i/o. */ |
352 | if (nr) { |
353 | struct buffer_head *tbh; |
354 | |
355 | /* Lock the buffers. */ |
356 | for (i = 0; i < nr; i++) { |
357 | tbh = arr[i]; |
358 | lock_buffer(tbh); |
359 | tbh->b_end_io = ntfs_end_buffer_async_read; |
360 | set_buffer_async_read(tbh); |
361 | } |
362 | /* Finally, start i/o on the buffers. */ |
363 | for (i = 0; i < nr; i++) { |
364 | tbh = arr[i]; |
365 | if (likely(!buffer_uptodate(tbh))) |
366 | submit_bh(READ, tbh); |
367 | else |
368 | ntfs_end_buffer_async_read(tbh, 1); |
369 | } |
370 | return 0; |
371 | } |
372 | /* No i/o was scheduled on any of the buffers. */ |
373 | if (likely(!PageError(page))) |
374 | SetPageUptodate(page); |
375 | else /* Signal synchronous i/o error. */ |
376 | nr = -EIO; |
377 | unlock_page(page); |
378 | return nr; |
379 | } |
380 | |
381 | /** |
382 | * ntfs_readpage - fill a @page of a @file with data from the device |
383 | * @file: open file to which the page @page belongs or NULL |
384 | * @page: page cache page to fill with data |
385 | * |
386 | * For non-resident attributes, ntfs_readpage() fills the @page of the open |
387 | * file @file by calling the ntfs version of the generic block_read_full_page() |
388 | * function, ntfs_read_block(), which in turn creates and reads in the buffers |
389 | * associated with the page asynchronously. |
390 | * |
391 | * For resident attributes, OTOH, ntfs_readpage() fills @page by copying the |
392 | * data from the mft record (which at this stage is most likely in memory) and |
393 | * fills the remainder with zeroes. Thus, in this case, I/O is synchronous, as |
394 | * even if the mft record is not cached at this point in time, we need to wait |
395 | * for it to be read in before we can do the copy. |
396 | * |
397 | * Return 0 on success and -errno on error. |
398 | */ |
399 | static int ntfs_readpage(struct file *file, struct page *page) |
400 | { |
401 | loff_t i_size; |
402 | struct inode *vi; |
403 | ntfs_inode *ni, *base_ni; |
404 | u8 *addr; |
405 | ntfs_attr_search_ctx *ctx; |
406 | MFT_RECORD *mrec; |
407 | unsigned long flags; |
408 | u32 attr_len; |
409 | int err = 0; |
410 | |
411 | retry_readpage: |
412 | BUG_ON(!PageLocked(page)); |
413 | vi = page->mapping->host; |
414 | i_size = i_size_read(vi); |
415 | /* Is the page fully outside i_size? (truncate in progress) */ |
416 | if (unlikely(page->index >= (i_size + PAGE_CACHE_SIZE - 1) >> |
417 | PAGE_CACHE_SHIFT)) { |
418 | zero_user(page, 0, PAGE_CACHE_SIZE); |
419 | ntfs_debug("Read outside i_size - truncated?"); |
420 | goto done; |
421 | } |
422 | /* |
423 | * This can potentially happen because we clear PageUptodate() during |
424 | * ntfs_writepage() of MstProtected() attributes. |
425 | */ |
426 | if (PageUptodate(page)) { |
427 | unlock_page(page); |
428 | return 0; |
429 | } |
430 | ni = NTFS_I(vi); |
431 | /* |
432 | * Only $DATA attributes can be encrypted and only unnamed $DATA |
433 | * attributes can be compressed. Index root can have the flags set but |
434 | * this means to create compressed/encrypted files, not that the |
435 | * attribute is compressed/encrypted. Note we need to check for |
436 | * AT_INDEX_ALLOCATION since this is the type of both directory and |
437 | * index inodes. |
438 | */ |
439 | if (ni->type != AT_INDEX_ALLOCATION) { |
440 | /* If attribute is encrypted, deny access, just like NT4. */ |
441 | if (NInoEncrypted(ni)) { |
442 | BUG_ON(ni->type != AT_DATA); |
443 | err = -EACCES; |
444 | goto err_out; |
445 | } |
446 | /* Compressed data streams are handled in compress.c. */ |
447 | if (NInoNonResident(ni) && NInoCompressed(ni)) { |
448 | BUG_ON(ni->type != AT_DATA); |
449 | BUG_ON(ni->name_len); |
450 | return ntfs_read_compressed_block(page); |
451 | } |
452 | } |
453 | /* NInoNonResident() == NInoIndexAllocPresent() */ |
454 | if (NInoNonResident(ni)) { |
455 | /* Normal, non-resident data stream. */ |
456 | return ntfs_read_block(page); |
457 | } |
458 | /* |
459 | * Attribute is resident, implying it is not compressed or encrypted. |
460 | * This also means the attribute is smaller than an mft record and |
461 | * hence smaller than a page, so can simply zero out any pages with |
462 | * index above 0. Note the attribute can actually be marked compressed |
463 | * but if it is resident the actual data is not compressed so we are |
464 | * ok to ignore the compressed flag here. |
465 | */ |
466 | if (unlikely(page->index > 0)) { |
467 | zero_user(page, 0, PAGE_CACHE_SIZE); |
468 | goto done; |
469 | } |
470 | if (!NInoAttr(ni)) |
471 | base_ni = ni; |
472 | else |
473 | base_ni = ni->ext.base_ntfs_ino; |
474 | /* Map, pin, and lock the mft record. */ |
475 | mrec = map_mft_record(base_ni); |
476 | if (IS_ERR(mrec)) { |
477 | err = PTR_ERR(mrec); |
478 | goto err_out; |
479 | } |
480 | /* |
481 | * If a parallel write made the attribute non-resident, drop the mft |
482 | * record and retry the readpage. |
483 | */ |
484 | if (unlikely(NInoNonResident(ni))) { |
485 | unmap_mft_record(base_ni); |
486 | goto retry_readpage; |
487 | } |
488 | ctx = ntfs_attr_get_search_ctx(base_ni, mrec); |
489 | if (unlikely(!ctx)) { |
490 | err = -ENOMEM; |
491 | goto unm_err_out; |
492 | } |
493 | err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, |
494 | CASE_SENSITIVE, 0, NULL, 0, ctx); |
495 | if (unlikely(err)) |
496 | goto put_unm_err_out; |
497 | attr_len = le32_to_cpu(ctx->attr->data.resident.value_length); |
498 | read_lock_irqsave(&ni->size_lock, flags); |
499 | if (unlikely(attr_len > ni->initialized_size)) |
500 | attr_len = ni->initialized_size; |
501 | i_size = i_size_read(vi); |
502 | read_unlock_irqrestore(&ni->size_lock, flags); |
503 | if (unlikely(attr_len > i_size)) { |
504 | /* Race with shrinking truncate. */ |
505 | attr_len = i_size; |
506 | } |
507 | addr = kmap_atomic(page, KM_USER0); |
508 | /* Copy the data to the page. */ |
509 | memcpy(addr, (u8*)ctx->attr + |
510 | le16_to_cpu(ctx->attr->data.resident.value_offset), |
511 | attr_len); |
512 | /* Zero the remainder of the page. */ |
513 | memset(addr + attr_len, 0, PAGE_CACHE_SIZE - attr_len); |
514 | flush_dcache_page(page); |
515 | kunmap_atomic(addr, KM_USER0); |
516 | put_unm_err_out: |
517 | ntfs_attr_put_search_ctx(ctx); |
518 | unm_err_out: |
519 | unmap_mft_record(base_ni); |
520 | done: |
521 | SetPageUptodate(page); |
522 | err_out: |
523 | unlock_page(page); |
524 | return err; |
525 | } |
526 | |
527 | #ifdef NTFS_RW |
528 | |
529 | /** |
530 | * ntfs_write_block - write a @page to the backing store |
531 | * @page: page cache page to write out |
532 | * @wbc: writeback control structure |
533 | * |
534 | * This function is for writing pages belonging to non-resident, non-mst |
535 | * protected attributes to their backing store. |
536 | * |
537 | * For a page with buffers, map and write the dirty buffers asynchronously |
538 | * under page writeback. For a page without buffers, create buffers for the |
539 | * page, then proceed as above. |
540 | * |
541 | * If a page doesn't have buffers the page dirty state is definitive. If a page |
542 | * does have buffers, the page dirty state is just a hint, and the buffer dirty |
543 | * state is definitive. (A hint which has rules: dirty buffers against a clean |
544 | * page is illegal. Other combinations are legal and need to be handled. In |
545 | * particular a dirty page containing clean buffers for example.) |
546 | * |
547 | * Return 0 on success and -errno on error. |
548 | * |
549 | * Based on ntfs_read_block() and __block_write_full_page(). |
550 | */ |
551 | static int ntfs_write_block(struct page *page, struct writeback_control *wbc) |
552 | { |
553 | VCN vcn; |
554 | LCN lcn; |
555 | s64 initialized_size; |
556 | loff_t i_size; |
557 | sector_t block, dblock, iblock; |
558 | struct inode *vi; |
559 | ntfs_inode *ni; |
560 | ntfs_volume *vol; |
561 | runlist_element *rl; |
562 | struct buffer_head *bh, *head; |
563 | unsigned long flags; |
564 | unsigned int blocksize, vcn_ofs; |
565 | int err; |
566 | bool need_end_writeback; |
567 | unsigned char blocksize_bits; |
568 | |
569 | vi = page->mapping->host; |
570 | ni = NTFS_I(vi); |
571 | vol = ni->vol; |
572 | |
573 | ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index " |
574 | "0x%lx.", ni->mft_no, ni->type, page->index); |
575 | |
576 | BUG_ON(!NInoNonResident(ni)); |
577 | BUG_ON(NInoMstProtected(ni)); |
578 | blocksize = vol->sb->s_blocksize; |
579 | blocksize_bits = vol->sb->s_blocksize_bits; |
580 | if (!page_has_buffers(page)) { |
581 | BUG_ON(!PageUptodate(page)); |
582 | create_empty_buffers(page, blocksize, |
583 | (1 << BH_Uptodate) | (1 << BH_Dirty)); |
584 | if (unlikely(!page_has_buffers(page))) { |
585 | ntfs_warning(vol->sb, "Error allocating page " |
586 | "buffers. Redirtying page so we try " |
587 | "again later."); |
588 | /* |
589 | * Put the page back on mapping->dirty_pages, but leave |
590 | * its buffers' dirty state as-is. |
591 | */ |
592 | redirty_page_for_writepage(wbc, page); |
593 | unlock_page(page); |
594 | return 0; |
595 | } |
596 | } |
597 | bh = head = page_buffers(page); |
598 | BUG_ON(!bh); |
599 | |
600 | /* NOTE: Different naming scheme to ntfs_read_block()! */ |
601 | |
602 | /* The first block in the page. */ |
603 | block = (s64)page->index << (PAGE_CACHE_SHIFT - blocksize_bits); |
604 | |
605 | read_lock_irqsave(&ni->size_lock, flags); |
606 | i_size = i_size_read(vi); |
607 | initialized_size = ni->initialized_size; |
608 | read_unlock_irqrestore(&ni->size_lock, flags); |
609 | |
610 | /* The first out of bounds block for the data size. */ |
611 | dblock = (i_size + blocksize - 1) >> blocksize_bits; |
612 | |
613 | /* The last (fully or partially) initialized block. */ |
614 | iblock = initialized_size >> blocksize_bits; |
615 | |
616 | /* |
617 | * Be very careful. We have no exclusion from __set_page_dirty_buffers |
618 | * here, and the (potentially unmapped) buffers may become dirty at |
619 | * any time. If a buffer becomes dirty here after we've inspected it |
620 | * then we just miss that fact, and the page stays dirty. |
621 | * |
622 | * Buffers outside i_size may be dirtied by __set_page_dirty_buffers; |
623 | * handle that here by just cleaning them. |
624 | */ |
625 | |
626 | /* |
627 | * Loop through all the buffers in the page, mapping all the dirty |
628 | * buffers to disk addresses and handling any aliases from the |
629 | * underlying block device's mapping. |
630 | */ |
631 | rl = NULL; |
632 | err = 0; |
633 | do { |
634 | bool is_retry = false; |
635 | |
636 | if (unlikely(block >= dblock)) { |
637 | /* |
638 | * Mapped buffers outside i_size will occur, because |
639 | * this page can be outside i_size when there is a |
640 | * truncate in progress. The contents of such buffers |
641 | * were zeroed by ntfs_writepage(). |
642 | * |
643 | * FIXME: What about the small race window where |
644 | * ntfs_writepage() has not done any clearing because |
645 | * the page was within i_size but before we get here, |
646 | * vmtruncate() modifies i_size? |
647 | */ |
648 | clear_buffer_dirty(bh); |
649 | set_buffer_uptodate(bh); |
650 | continue; |
651 | } |
652 | |
653 | /* Clean buffers are not written out, so no need to map them. */ |
654 | if (!buffer_dirty(bh)) |
655 | continue; |
656 | |
657 | /* Make sure we have enough initialized size. */ |
658 | if (unlikely((block >= iblock) && |
659 | (initialized_size < i_size))) { |
660 | /* |
661 | * If this page is fully outside initialized size, zero |
662 | * out all pages between the current initialized size |
663 | * and the current page. Just use ntfs_readpage() to do |
664 | * the zeroing transparently. |
665 | */ |
666 | if (block > iblock) { |
667 | // TODO: |
668 | // For each page do: |
669 | // - read_cache_page() |
670 | // Again for each page do: |
671 | // - wait_on_page_locked() |
672 | // - Check (PageUptodate(page) && |
673 | // !PageError(page)) |
674 | // Update initialized size in the attribute and |
675 | // in the inode. |
676 | // Again, for each page do: |
677 | // __set_page_dirty_buffers(); |
678 | // page_cache_release() |
679 | // We don't need to wait on the writes. |
680 | // Update iblock. |
681 | } |
682 | /* |
683 | * The current page straddles initialized size. Zero |
684 | * all non-uptodate buffers and set them uptodate (and |
685 | * dirty?). Note, there aren't any non-uptodate buffers |
686 | * if the page is uptodate. |
687 | * FIXME: For an uptodate page, the buffers may need to |
688 | * be written out because they were not initialized on |
689 | * disk before. |
690 | */ |
691 | if (!PageUptodate(page)) { |
692 | // TODO: |
693 | // Zero any non-uptodate buffers up to i_size. |
694 | // Set them uptodate and dirty. |
695 | } |
696 | // TODO: |
697 | // Update initialized size in the attribute and in the |
698 | // inode (up to i_size). |
699 | // Update iblock. |
700 | // FIXME: This is inefficient. Try to batch the two |
701 | // size changes to happen in one go. |
702 | ntfs_error(vol->sb, "Writing beyond initialized size " |
703 | "is not supported yet. Sorry."); |
704 | err = -EOPNOTSUPP; |
705 | break; |
706 | // Do NOT set_buffer_new() BUT DO clear buffer range |
707 | // outside write request range. |
708 | // set_buffer_uptodate() on complete buffers as well as |
709 | // set_buffer_dirty(). |
710 | } |
711 | |
712 | /* No need to map buffers that are already mapped. */ |
713 | if (buffer_mapped(bh)) |
714 | continue; |
715 | |
716 | /* Unmapped, dirty buffer. Need to map it. */ |
717 | bh->b_bdev = vol->sb->s_bdev; |
718 | |
719 | /* Convert block into corresponding vcn and offset. */ |
720 | vcn = (VCN)block << blocksize_bits; |
721 | vcn_ofs = vcn & vol->cluster_size_mask; |
722 | vcn >>= vol->cluster_size_bits; |
723 | if (!rl) { |
724 | lock_retry_remap: |
725 | down_read(&ni->runlist.lock); |
726 | rl = ni->runlist.rl; |
727 | } |
728 | if (likely(rl != NULL)) { |
729 | /* Seek to element containing target vcn. */ |
730 | while (rl->length && rl[1].vcn <= vcn) |
731 | rl++; |
732 | lcn = ntfs_rl_vcn_to_lcn(rl, vcn); |
733 | } else |
734 | lcn = LCN_RL_NOT_MAPPED; |
735 | /* Successful remap. */ |
736 | if (lcn >= 0) { |
737 | /* Setup buffer head to point to correct block. */ |
738 | bh->b_blocknr = ((lcn << vol->cluster_size_bits) + |
739 | vcn_ofs) >> blocksize_bits; |
740 | set_buffer_mapped(bh); |
741 | continue; |
742 | } |
743 | /* It is a hole, need to instantiate it. */ |
744 | if (lcn == LCN_HOLE) { |
745 | u8 *kaddr; |
746 | unsigned long *bpos, *bend; |
747 | |
748 | /* Check if the buffer is zero. */ |
749 | kaddr = kmap_atomic(page, KM_USER0); |
750 | bpos = (unsigned long *)(kaddr + bh_offset(bh)); |
751 | bend = (unsigned long *)((u8*)bpos + blocksize); |
752 | do { |
753 | if (unlikely(*bpos)) |
754 | break; |
755 | } while (likely(++bpos < bend)); |
756 | kunmap_atomic(kaddr, KM_USER0); |
757 | if (bpos == bend) { |
758 | /* |
759 | * Buffer is zero and sparse, no need to write |
760 | * it. |
761 | */ |
762 | bh->b_blocknr = -1; |
763 | clear_buffer_dirty(bh); |
764 | continue; |
765 | } |
766 | // TODO: Instantiate the hole. |
767 | // clear_buffer_new(bh); |
768 | // unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); |
769 | ntfs_error(vol->sb, "Writing into sparse regions is " |
770 | "not supported yet. Sorry."); |
771 | err = -EOPNOTSUPP; |
772 | break; |
773 | } |
774 | /* If first try and runlist unmapped, map and retry. */ |
775 | if (!is_retry && lcn == LCN_RL_NOT_MAPPED) { |
776 | is_retry = true; |
777 | /* |
778 | * Attempt to map runlist, dropping lock for |
779 | * the duration. |
780 | */ |
781 | up_read(&ni->runlist.lock); |
782 | err = ntfs_map_runlist(ni, vcn); |
783 | if (likely(!err)) |
784 | goto lock_retry_remap; |
785 | rl = NULL; |
786 | } else if (!rl) |
787 | up_read(&ni->runlist.lock); |
788 | /* |
789 | * If buffer is outside the runlist, truncate has cut it out |
790 | * of the runlist. Just clean and clear the buffer and set it |
791 | * uptodate so it can get discarded by the VM. |
792 | */ |
793 | if (err == -ENOENT || lcn == LCN_ENOENT) { |
794 | bh->b_blocknr = -1; |
795 | clear_buffer_dirty(bh); |
796 | zero_user(page, bh_offset(bh), blocksize); |
797 | set_buffer_uptodate(bh); |
798 | err = 0; |
799 | continue; |
800 | } |
801 | /* Failed to map the buffer, even after retrying. */ |
802 | if (!err) |
803 | err = -EIO; |
804 | bh->b_blocknr = -1; |
805 | ntfs_error(vol->sb, "Failed to write to inode 0x%lx, " |
806 | "attribute type 0x%x, vcn 0x%llx, offset 0x%x " |
807 | "because its location on disk could not be " |
808 | "determined%s (error code %i).", ni->mft_no, |
809 | ni->type, (unsigned long long)vcn, |
810 | vcn_ofs, is_retry ? " even after " |
811 | "retrying" : "", err); |
812 | break; |
813 | } while (block++, (bh = bh->b_this_page) != head); |
814 | |
815 | /* Release the lock if we took it. */ |
816 | if (rl) |
817 | up_read(&ni->runlist.lock); |
818 | |
819 | /* For the error case, need to reset bh to the beginning. */ |
820 | bh = head; |
821 | |
822 | /* Just an optimization, so ->readpage() is not called later. */ |
823 | if (unlikely(!PageUptodate(page))) { |
824 | int uptodate = 1; |
825 | do { |
826 | if (!buffer_uptodate(bh)) { |
827 | uptodate = 0; |
828 | bh = head; |
829 | break; |
830 | } |
831 | } while ((bh = bh->b_this_page) != head); |
832 | if (uptodate) |
833 | SetPageUptodate(page); |
834 | } |
835 | |
836 | /* Setup all mapped, dirty buffers for async write i/o. */ |
837 | do { |
838 | if (buffer_mapped(bh) && buffer_dirty(bh)) { |
839 | lock_buffer(bh); |
840 | if (test_clear_buffer_dirty(bh)) { |
841 | BUG_ON(!buffer_uptodate(bh)); |
842 | mark_buffer_async_write(bh); |
843 | } else |
844 | unlock_buffer(bh); |
845 | } else if (unlikely(err)) { |
846 | /* |
847 | * For the error case. The buffer may have been set |
848 | * dirty during attachment to a dirty page. |
849 | */ |
850 | if (err != -ENOMEM) |
851 | clear_buffer_dirty(bh); |
852 | } |
853 | } while ((bh = bh->b_this_page) != head); |
854 | |
855 | if (unlikely(err)) { |
856 | // TODO: Remove the -EOPNOTSUPP check later on... |
857 | if (unlikely(err == -EOPNOTSUPP)) |
858 | err = 0; |
859 | else if (err == -ENOMEM) { |
860 | ntfs_warning(vol->sb, "Error allocating memory. " |
861 | "Redirtying page so we try again " |
862 | "later."); |
863 | /* |
864 | * Put the page back on mapping->dirty_pages, but |
865 | * leave its buffer's dirty state as-is. |
866 | */ |
867 | redirty_page_for_writepage(wbc, page); |
868 | err = 0; |
869 | } else |
870 | SetPageError(page); |
871 | } |
872 | |
873 | BUG_ON(PageWriteback(page)); |
874 | set_page_writeback(page); /* Keeps try_to_free_buffers() away. */ |
875 | |
876 | /* Submit the prepared buffers for i/o. */ |
877 | need_end_writeback = true; |
878 | do { |
879 | struct buffer_head *next = bh->b_this_page; |
880 | if (buffer_async_write(bh)) { |
881 | submit_bh(WRITE, bh); |
882 | need_end_writeback = false; |
883 | } |
884 | bh = next; |
885 | } while (bh != head); |
886 | unlock_page(page); |
887 | |
888 | /* If no i/o was started, need to end_page_writeback(). */ |
889 | if (unlikely(need_end_writeback)) |
890 | end_page_writeback(page); |
891 | |
892 | ntfs_debug("Done."); |
893 | return err; |
894 | } |
895 | |
896 | /** |
897 | * ntfs_write_mst_block - write a @page to the backing store |
898 | * @page: page cache page to write out |
899 | * @wbc: writeback control structure |
900 | * |
901 | * This function is for writing pages belonging to non-resident, mst protected |
902 | * attributes to their backing store. The only supported attributes are index |
903 | * allocation and $MFT/$DATA. Both directory inodes and index inodes are |
904 | * supported for the index allocation case. |
905 | * |
906 | * The page must remain locked for the duration of the write because we apply |
907 | * the mst fixups, write, and then undo the fixups, so if we were to unlock the |
908 | * page before undoing the fixups, any other user of the page will see the |
909 | * page contents as corrupt. |
910 | * |
911 | * We clear the page uptodate flag for the duration of the function to ensure |
912 | * exclusion for the $MFT/$DATA case against someone mapping an mft record we |
913 | * are about to apply the mst fixups to. |
914 | * |
915 | * Return 0 on success and -errno on error. |
916 | * |
917 | * Based on ntfs_write_block(), ntfs_mft_writepage(), and |
918 | * write_mft_record_nolock(). |
919 | */ |
920 | static int ntfs_write_mst_block(struct page *page, |
921 | struct writeback_control *wbc) |
922 | { |
923 | sector_t block, dblock, rec_block; |
924 | struct inode *vi = page->mapping->host; |
925 | ntfs_inode *ni = NTFS_I(vi); |
926 | ntfs_volume *vol = ni->vol; |
927 | u8 *kaddr; |
928 | unsigned int rec_size = ni->itype.index.block_size; |
929 | ntfs_inode *locked_nis[PAGE_CACHE_SIZE / rec_size]; |
930 | struct buffer_head *bh, *head, *tbh, *rec_start_bh; |
931 | struct buffer_head *bhs[MAX_BUF_PER_PAGE]; |
932 | runlist_element *rl; |
933 | int i, nr_locked_nis, nr_recs, nr_bhs, max_bhs, bhs_per_rec, err, err2; |
934 | unsigned bh_size, rec_size_bits; |
935 | bool sync, is_mft, page_is_dirty, rec_is_dirty; |
936 | unsigned char bh_size_bits; |
937 | |
938 | ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index " |
939 | "0x%lx.", vi->i_ino, ni->type, page->index); |
940 | BUG_ON(!NInoNonResident(ni)); |
941 | BUG_ON(!NInoMstProtected(ni)); |
942 | is_mft = (S_ISREG(vi->i_mode) && !vi->i_ino); |
943 | /* |
944 | * NOTE: ntfs_write_mst_block() would be called for $MFTMirr if a page |
945 | * in its page cache were to be marked dirty. However this should |
946 | * never happen with the current driver and considering we do not |
947 | * handle this case here we do want to BUG(), at least for now. |
948 | */ |
949 | BUG_ON(!(is_mft || S_ISDIR(vi->i_mode) || |
950 | (NInoAttr(ni) && ni->type == AT_INDEX_ALLOCATION))); |
951 | bh_size = vol->sb->s_blocksize; |
952 | bh_size_bits = vol->sb->s_blocksize_bits; |
953 | max_bhs = PAGE_CACHE_SIZE / bh_size; |
954 | BUG_ON(!max_bhs); |
955 | BUG_ON(max_bhs > MAX_BUF_PER_PAGE); |
956 | |
957 | /* Were we called for sync purposes? */ |
958 | sync = (wbc->sync_mode == WB_SYNC_ALL); |
959 | |
960 | /* Make sure we have mapped buffers. */ |
961 | bh = head = page_buffers(page); |
962 | BUG_ON(!bh); |
963 | |
964 | rec_size_bits = ni->itype.index.block_size_bits; |
965 | BUG_ON(!(PAGE_CACHE_SIZE >> rec_size_bits)); |
966 | bhs_per_rec = rec_size >> bh_size_bits; |
967 | BUG_ON(!bhs_per_rec); |
968 | |
969 | /* The first block in the page. */ |
970 | rec_block = block = (sector_t)page->index << |
971 | (PAGE_CACHE_SHIFT - bh_size_bits); |
972 | |
973 | /* The first out of bounds block for the data size. */ |
974 | dblock = (i_size_read(vi) + bh_size - 1) >> bh_size_bits; |
975 | |
976 | rl = NULL; |
977 | err = err2 = nr_bhs = nr_recs = nr_locked_nis = 0; |
978 | page_is_dirty = rec_is_dirty = false; |
979 | rec_start_bh = NULL; |
980 | do { |
981 | bool is_retry = false; |
982 | |
983 | if (likely(block < rec_block)) { |
984 | if (unlikely(block >= dblock)) { |
985 | clear_buffer_dirty(bh); |
986 | set_buffer_uptodate(bh); |
987 | continue; |
988 | } |
989 | /* |
990 | * This block is not the first one in the record. We |
991 | * ignore the buffer's dirty state because we could |
992 | * have raced with a parallel mark_ntfs_record_dirty(). |
993 | */ |
994 | if (!rec_is_dirty) |
995 | continue; |
996 | if (unlikely(err2)) { |
997 | if (err2 != -ENOMEM) |
998 | clear_buffer_dirty(bh); |
999 | continue; |
1000 | } |
1001 | } else /* if (block == rec_block) */ { |
1002 | BUG_ON(block > rec_block); |
1003 | /* This block is the first one in the record. */ |
1004 | rec_block += bhs_per_rec; |
1005 | err2 = 0; |
1006 | if (unlikely(block >= dblock)) { |
1007 | clear_buffer_dirty(bh); |
1008 | continue; |
1009 | } |
1010 | if (!buffer_dirty(bh)) { |
1011 | /* Clean records are not written out. */ |
1012 | rec_is_dirty = false; |
1013 | continue; |
1014 | } |
1015 | rec_is_dirty = true; |
1016 | rec_start_bh = bh; |
1017 | } |
1018 | /* Need to map the buffer if it is not mapped already. */ |
1019 | if (unlikely(!buffer_mapped(bh))) { |
1020 | VCN vcn; |
1021 | LCN lcn; |
1022 | unsigned int vcn_ofs; |
1023 | |
1024 | bh->b_bdev = vol->sb->s_bdev; |
1025 | /* Obtain the vcn and offset of the current block. */ |
1026 | vcn = (VCN)block << bh_size_bits; |
1027 | vcn_ofs = vcn & vol->cluster_size_mask; |
1028 | vcn >>= vol->cluster_size_bits; |
1029 | if (!rl) { |
1030 | lock_retry_remap: |
1031 | down_read(&ni->runlist.lock); |
1032 | rl = ni->runlist.rl; |
1033 | } |
1034 | if (likely(rl != NULL)) { |
1035 | /* Seek to element containing target vcn. */ |
1036 | while (rl->length && rl[1].vcn <= vcn) |
1037 | rl++; |
1038 | lcn = ntfs_rl_vcn_to_lcn(rl, vcn); |
1039 | } else |
1040 | lcn = LCN_RL_NOT_MAPPED; |
1041 | /* Successful remap. */ |
1042 | if (likely(lcn >= 0)) { |
1043 | /* Setup buffer head to correct block. */ |
1044 | bh->b_blocknr = ((lcn << |
1045 | vol->cluster_size_bits) + |
1046 | vcn_ofs) >> bh_size_bits; |
1047 | set_buffer_mapped(bh); |
1048 | } else { |
1049 | /* |
1050 | * Remap failed. Retry to map the runlist once |
1051 | * unless we are working on $MFT which always |
1052 | * has the whole of its runlist in memory. |
1053 | */ |
1054 | if (!is_mft && !is_retry && |
1055 | lcn == LCN_RL_NOT_MAPPED) { |
1056 | is_retry = true; |
1057 | /* |
1058 | * Attempt to map runlist, dropping |
1059 | * lock for the duration. |
1060 | */ |
1061 | up_read(&ni->runlist.lock); |
1062 | err2 = ntfs_map_runlist(ni, vcn); |
1063 | if (likely(!err2)) |
1064 | goto lock_retry_remap; |
1065 | if (err2 == -ENOMEM) |
1066 | page_is_dirty = true; |
1067 | lcn = err2; |
1068 | } else { |
1069 | err2 = -EIO; |
1070 | if (!rl) |
1071 | up_read(&ni->runlist.lock); |
1072 | } |
1073 | /* Hard error. Abort writing this record. */ |
1074 | if (!err || err == -ENOMEM) |
1075 | err = err2; |
1076 | bh->b_blocknr = -1; |
1077 | ntfs_error(vol->sb, "Cannot write ntfs record " |
1078 | "0x%llx (inode 0x%lx, " |
1079 | "attribute type 0x%x) because " |
1080 | "its location on disk could " |
1081 | "not be determined (error " |
1082 | "code %lli).", |
1083 | (long long)block << |
1084 | bh_size_bits >> |
1085 | vol->mft_record_size_bits, |
1086 | ni->mft_no, ni->type, |
1087 | (long long)lcn); |
1088 | /* |
1089 | * If this is not the first buffer, remove the |
1090 | * buffers in this record from the list of |
1091 | * buffers to write and clear their dirty bit |
1092 | * if not error -ENOMEM. |
1093 | */ |
1094 | if (rec_start_bh != bh) { |
1095 | while (bhs[--nr_bhs] != rec_start_bh) |
1096 | ; |
1097 | if (err2 != -ENOMEM) { |
1098 | do { |
1099 | clear_buffer_dirty( |
1100 | rec_start_bh); |
1101 | } while ((rec_start_bh = |
1102 | rec_start_bh-> |
1103 | b_this_page) != |
1104 | bh); |
1105 | } |
1106 | } |
1107 | continue; |
1108 | } |
1109 | } |
1110 | BUG_ON(!buffer_uptodate(bh)); |
1111 | BUG_ON(nr_bhs >= max_bhs); |
1112 | bhs[nr_bhs++] = bh; |
1113 | } while (block++, (bh = bh->b_this_page) != head); |
1114 | if (unlikely(rl)) |
1115 | up_read(&ni->runlist.lock); |
1116 | /* If there were no dirty buffers, we are done. */ |
1117 | if (!nr_bhs) |
1118 | goto done; |
1119 | /* Map the page so we can access its contents. */ |
1120 | kaddr = kmap(page); |
1121 | /* Clear the page uptodate flag whilst the mst fixups are applied. */ |
1122 | BUG_ON(!PageUptodate(page)); |
1123 | ClearPageUptodate(page); |
1124 | for (i = 0; i < nr_bhs; i++) { |
1125 | unsigned int ofs; |
1126 | |
1127 | /* Skip buffers which are not at the beginning of records. */ |
1128 | if (i % bhs_per_rec) |
1129 | continue; |
1130 | tbh = bhs[i]; |
1131 | ofs = bh_offset(tbh); |
1132 | if (is_mft) { |
1133 | ntfs_inode *tni; |
1134 | unsigned long mft_no; |
1135 | |
1136 | /* Get the mft record number. */ |
1137 | mft_no = (((s64)page->index << PAGE_CACHE_SHIFT) + ofs) |
1138 | >> rec_size_bits; |
1139 | /* Check whether to write this mft record. */ |
1140 | tni = NULL; |
1141 | if (!ntfs_may_write_mft_record(vol, mft_no, |
1142 | (MFT_RECORD*)(kaddr + ofs), &tni)) { |
1143 | /* |
1144 | * The record should not be written. This |
1145 | * means we need to redirty the page before |
1146 | * returning. |
1147 | */ |
1148 | page_is_dirty = true; |
1149 | /* |
1150 | * Remove the buffers in this mft record from |
1151 | * the list of buffers to write. |
1152 | */ |
1153 | do { |
1154 | bhs[i] = NULL; |
1155 | } while (++i % bhs_per_rec); |
1156 | continue; |
1157 | } |
1158 | /* |
1159 | * The record should be written. If a locked ntfs |
1160 | * inode was returned, add it to the array of locked |
1161 | * ntfs inodes. |
1162 | */ |
1163 | if (tni) |
1164 | locked_nis[nr_locked_nis++] = tni; |
1165 | } |
1166 | /* Apply the mst protection fixups. */ |
1167 | err2 = pre_write_mst_fixup((NTFS_RECORD*)(kaddr + ofs), |
1168 | rec_size); |
1169 | if (unlikely(err2)) { |
1170 | if (!err || err == -ENOMEM) |
1171 | err = -EIO; |
1172 | ntfs_error(vol->sb, "Failed to apply mst fixups " |
1173 | "(inode 0x%lx, attribute type 0x%x, " |
1174 | "page index 0x%lx, page offset 0x%x)!" |
1175 | " Unmount and run chkdsk.", vi->i_ino, |
1176 | ni->type, page->index, ofs); |
1177 | /* |
1178 | * Mark all the buffers in this record clean as we do |
1179 | * not want to write corrupt data to disk. |
1180 | */ |
1181 | do { |
1182 | clear_buffer_dirty(bhs[i]); |
1183 | bhs[i] = NULL; |
1184 | } while (++i % bhs_per_rec); |
1185 | continue; |
1186 | } |
1187 | nr_recs++; |
1188 | } |
1189 | /* If no records are to be written out, we are done. */ |
1190 | if (!nr_recs) |
1191 | goto unm_done; |
1192 | flush_dcache_page(page); |
1193 | /* Lock buffers and start synchronous write i/o on them. */ |
1194 | for (i = 0; i < nr_bhs; i++) { |
1195 | tbh = bhs[i]; |
1196 | if (!tbh) |
1197 | continue; |
1198 | if (!trylock_buffer(tbh)) |
1199 | BUG(); |
1200 | /* The buffer dirty state is now irrelevant, just clean it. */ |
1201 | clear_buffer_dirty(tbh); |
1202 | BUG_ON(!buffer_uptodate(tbh)); |
1203 | BUG_ON(!buffer_mapped(tbh)); |
1204 | get_bh(tbh); |
1205 | tbh->b_end_io = end_buffer_write_sync; |
1206 | submit_bh(WRITE, tbh); |
1207 | } |
1208 | /* Synchronize the mft mirror now if not @sync. */ |
1209 | if (is_mft && !sync) |
1210 | goto do_mirror; |
1211 | do_wait: |
1212 | /* Wait on i/o completion of buffers. */ |
1213 | for (i = 0; i < nr_bhs; i++) { |
1214 | tbh = bhs[i]; |
1215 | if (!tbh) |
1216 | continue; |
1217 | wait_on_buffer(tbh); |
1218 | if (unlikely(!buffer_uptodate(tbh))) { |
1219 | ntfs_error(vol->sb, "I/O error while writing ntfs " |
1220 | "record buffer (inode 0x%lx, " |
1221 | "attribute type 0x%x, page index " |
1222 | "0x%lx, page offset 0x%lx)! Unmount " |
1223 | "and run chkdsk.", vi->i_ino, ni->type, |
1224 | page->index, bh_offset(tbh)); |
1225 | if (!err || err == -ENOMEM) |
1226 | err = -EIO; |
1227 | /* |
1228 | * Set the buffer uptodate so the page and buffer |
1229 | * states do not become out of sync. |
1230 | */ |
1231 | set_buffer_uptodate(tbh); |
1232 | } |
1233 | } |
1234 | /* If @sync, now synchronize the mft mirror. */ |
1235 | if (is_mft && sync) { |
1236 | do_mirror: |
1237 | for (i = 0; i < nr_bhs; i++) { |
1238 | unsigned long mft_no; |
1239 | unsigned int ofs; |
1240 | |
1241 | /* |
1242 | * Skip buffers which are not at the beginning of |
1243 | * records. |
1244 | */ |
1245 | if (i % bhs_per_rec) |
1246 | continue; |
1247 | tbh = bhs[i]; |
1248 | /* Skip removed buffers (and hence records). */ |
1249 | if (!tbh) |
1250 | continue; |
1251 | ofs = bh_offset(tbh); |
1252 | /* Get the mft record number. */ |
1253 | mft_no = (((s64)page->index << PAGE_CACHE_SHIFT) + ofs) |
1254 | >> rec_size_bits; |
1255 | if (mft_no < vol->mftmirr_size) |
1256 | ntfs_sync_mft_mirror(vol, mft_no, |
1257 | (MFT_RECORD*)(kaddr + ofs), |
1258 | sync); |
1259 | } |
1260 | if (!sync) |
1261 | goto do_wait; |
1262 | } |
1263 | /* Remove the mst protection fixups again. */ |
1264 | for (i = 0; i < nr_bhs; i++) { |
1265 | if (!(i % bhs_per_rec)) { |
1266 | tbh = bhs[i]; |
1267 | if (!tbh) |
1268 | continue; |
1269 | post_write_mst_fixup((NTFS_RECORD*)(kaddr + |
1270 | bh_offset(tbh))); |
1271 | } |
1272 | } |
1273 | flush_dcache_page(page); |
1274 | unm_done: |
1275 | /* Unlock any locked inodes. */ |
1276 | while (nr_locked_nis-- > 0) { |
1277 | ntfs_inode *tni, *base_tni; |
1278 | |
1279 | tni = locked_nis[nr_locked_nis]; |
1280 | /* Get the base inode. */ |
1281 | mutex_lock(&tni->extent_lock); |
1282 | if (tni->nr_extents >= 0) |
1283 | base_tni = tni; |
1284 | else { |
1285 | base_tni = tni->ext.base_ntfs_ino; |
1286 | BUG_ON(!base_tni); |
1287 | } |
1288 | mutex_unlock(&tni->extent_lock); |
1289 | ntfs_debug("Unlocking %s inode 0x%lx.", |
1290 | tni == base_tni ? "base" : "extent", |
1291 | tni->mft_no); |
1292 | mutex_unlock(&tni->mrec_lock); |
1293 | atomic_dec(&tni->count); |
1294 | iput(VFS_I(base_tni)); |
1295 | } |
1296 | SetPageUptodate(page); |
1297 | kunmap(page); |
1298 | done: |
1299 | if (unlikely(err && err != -ENOMEM)) { |
1300 | /* |
1301 | * Set page error if there is only one ntfs record in the page. |
1302 | * Otherwise we would loose per-record granularity. |
1303 | */ |
1304 | if (ni->itype.index.block_size == PAGE_CACHE_SIZE) |
1305 | SetPageError(page); |
1306 | NVolSetErrors(vol); |
1307 | } |
1308 | if (page_is_dirty) { |
1309 | ntfs_debug("Page still contains one or more dirty ntfs " |
1310 | "records. Redirtying the page starting at " |
1311 | "record 0x%lx.", page->index << |
1312 | (PAGE_CACHE_SHIFT - rec_size_bits)); |
1313 | redirty_page_for_writepage(wbc, page); |
1314 | unlock_page(page); |
1315 | } else { |
1316 | /* |
1317 | * Keep the VM happy. This must be done otherwise the |
1318 | * radix-tree tag PAGECACHE_TAG_DIRTY remains set even though |
1319 | * the page is clean. |
1320 | */ |
1321 | BUG_ON(PageWriteback(page)); |
1322 | set_page_writeback(page); |
1323 | unlock_page(page); |
1324 | end_page_writeback(page); |
1325 | } |
1326 | if (likely(!err)) |
1327 | ntfs_debug("Done."); |
1328 | return err; |
1329 | } |
1330 | |
1331 | /** |
1332 | * ntfs_writepage - write a @page to the backing store |
1333 | * @page: page cache page to write out |
1334 | * @wbc: writeback control structure |
1335 | * |
1336 | * This is called from the VM when it wants to have a dirty ntfs page cache |
1337 | * page cleaned. The VM has already locked the page and marked it clean. |
1338 | * |
1339 | * For non-resident attributes, ntfs_writepage() writes the @page by calling |
1340 | * the ntfs version of the generic block_write_full_page() function, |
1341 | * ntfs_write_block(), which in turn if necessary creates and writes the |
1342 | * buffers associated with the page asynchronously. |
1343 | * |
1344 | * For resident attributes, OTOH, ntfs_writepage() writes the @page by copying |
1345 | * the data to the mft record (which at this stage is most likely in memory). |
1346 | * The mft record is then marked dirty and written out asynchronously via the |
1347 | * vfs inode dirty code path for the inode the mft record belongs to or via the |
1348 | * vm page dirty code path for the page the mft record is in. |
1349 | * |
1350 | * Based on ntfs_readpage() and fs/buffer.c::block_write_full_page(). |
1351 | * |
1352 | * Return 0 on success and -errno on error. |
1353 | */ |
1354 | static int ntfs_writepage(struct page *page, struct writeback_control *wbc) |
1355 | { |
1356 | loff_t i_size; |
1357 | struct inode *vi = page->mapping->host; |
1358 | ntfs_inode *base_ni = NULL, *ni = NTFS_I(vi); |
1359 | char *addr; |
1360 | ntfs_attr_search_ctx *ctx = NULL; |
1361 | MFT_RECORD *m = NULL; |
1362 | u32 attr_len; |
1363 | int err; |
1364 | |
1365 | retry_writepage: |
1366 | BUG_ON(!PageLocked(page)); |
1367 | i_size = i_size_read(vi); |
1368 | /* Is the page fully outside i_size? (truncate in progress) */ |
1369 | if (unlikely(page->index >= (i_size + PAGE_CACHE_SIZE - 1) >> |
1370 | PAGE_CACHE_SHIFT)) { |
1371 | /* |
1372 | * The page may have dirty, unmapped buffers. Make them |
1373 | * freeable here, so the page does not leak. |
1374 | */ |
1375 | block_invalidatepage(page, 0); |
1376 | unlock_page(page); |
1377 | ntfs_debug("Write outside i_size - truncated?"); |
1378 | return 0; |
1379 | } |
1380 | /* |
1381 | * Only $DATA attributes can be encrypted and only unnamed $DATA |
1382 | * attributes can be compressed. Index root can have the flags set but |
1383 | * this means to create compressed/encrypted files, not that the |
1384 | * attribute is compressed/encrypted. Note we need to check for |
1385 | * AT_INDEX_ALLOCATION since this is the type of both directory and |
1386 | * index inodes. |
1387 | */ |
1388 | if (ni->type != AT_INDEX_ALLOCATION) { |
1389 | /* If file is encrypted, deny access, just like NT4. */ |
1390 | if (NInoEncrypted(ni)) { |
1391 | unlock_page(page); |
1392 | BUG_ON(ni->type != AT_DATA); |
1393 | ntfs_debug("Denying write access to encrypted file."); |
1394 | return -EACCES; |
1395 | } |
1396 | /* Compressed data streams are handled in compress.c. */ |
1397 | if (NInoNonResident(ni) && NInoCompressed(ni)) { |
1398 | BUG_ON(ni->type != AT_DATA); |
1399 | BUG_ON(ni->name_len); |
1400 | // TODO: Implement and replace this with |
1401 | // return ntfs_write_compressed_block(page); |
1402 | unlock_page(page); |
1403 | ntfs_error(vi->i_sb, "Writing to compressed files is " |
1404 | "not supported yet. Sorry."); |
1405 | return -EOPNOTSUPP; |
1406 | } |
1407 | // TODO: Implement and remove this check. |
1408 | if (NInoNonResident(ni) && NInoSparse(ni)) { |
1409 | unlock_page(page); |
1410 | ntfs_error(vi->i_sb, "Writing to sparse files is not " |
1411 | "supported yet. Sorry."); |
1412 | return -EOPNOTSUPP; |
1413 | } |
1414 | } |
1415 | /* NInoNonResident() == NInoIndexAllocPresent() */ |
1416 | if (NInoNonResident(ni)) { |
1417 | /* We have to zero every time due to mmap-at-end-of-file. */ |
1418 | if (page->index >= (i_size >> PAGE_CACHE_SHIFT)) { |
1419 | /* The page straddles i_size. */ |
1420 | unsigned int ofs = i_size & ~PAGE_CACHE_MASK; |
1421 | zero_user_segment(page, ofs, PAGE_CACHE_SIZE); |
1422 | } |
1423 | /* Handle mst protected attributes. */ |
1424 | if (NInoMstProtected(ni)) |
1425 | return ntfs_write_mst_block(page, wbc); |
1426 | /* Normal, non-resident data stream. */ |
1427 | return ntfs_write_block(page, wbc); |
1428 | } |
1429 | /* |
1430 | * Attribute is resident, implying it is not compressed, encrypted, or |
1431 | * mst protected. This also means the attribute is smaller than an mft |
1432 | * record and hence smaller than a page, so can simply return error on |
1433 | * any pages with index above 0. Note the attribute can actually be |
1434 | * marked compressed but if it is resident the actual data is not |
1435 | * compressed so we are ok to ignore the compressed flag here. |
1436 | */ |
1437 | BUG_ON(page_has_buffers(page)); |
1438 | BUG_ON(!PageUptodate(page)); |
1439 | if (unlikely(page->index > 0)) { |
1440 | ntfs_error(vi->i_sb, "BUG()! page->index (0x%lx) > 0. " |
1441 | "Aborting write.", page->index); |
1442 | BUG_ON(PageWriteback(page)); |
1443 | set_page_writeback(page); |
1444 | unlock_page(page); |
1445 | end_page_writeback(page); |
1446 | return -EIO; |
1447 | } |
1448 | if (!NInoAttr(ni)) |
1449 | base_ni = ni; |
1450 | else |
1451 | base_ni = ni->ext.base_ntfs_ino; |
1452 | /* Map, pin, and lock the mft record. */ |
1453 | m = map_mft_record(base_ni); |
1454 | if (IS_ERR(m)) { |
1455 | err = PTR_ERR(m); |
1456 | m = NULL; |
1457 | ctx = NULL; |
1458 | goto err_out; |
1459 | } |
1460 | /* |
1461 | * If a parallel write made the attribute non-resident, drop the mft |
1462 | * record and retry the writepage. |
1463 | */ |
1464 | if (unlikely(NInoNonResident(ni))) { |
1465 | unmap_mft_record(base_ni); |
1466 | goto retry_writepage; |
1467 | } |
1468 | ctx = ntfs_attr_get_search_ctx(base_ni, m); |
1469 | if (unlikely(!ctx)) { |
1470 | err = -ENOMEM; |
1471 | goto err_out; |
1472 | } |
1473 | err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, |
1474 | CASE_SENSITIVE, 0, NULL, 0, ctx); |
1475 | if (unlikely(err)) |
1476 | goto err_out; |
1477 | /* |
1478 | * Keep the VM happy. This must be done otherwise the radix-tree tag |
1479 | * PAGECACHE_TAG_DIRTY remains set even though the page is clean. |
1480 | */ |
1481 | BUG_ON(PageWriteback(page)); |
1482 | set_page_writeback(page); |
1483 | unlock_page(page); |
1484 | attr_len = le32_to_cpu(ctx->attr->data.resident.value_length); |
1485 | i_size = i_size_read(vi); |
1486 | if (unlikely(attr_len > i_size)) { |
1487 | /* Race with shrinking truncate or a failed truncate. */ |
1488 | attr_len = i_size; |
1489 | /* |
1490 | * If the truncate failed, fix it up now. If a concurrent |
1491 | * truncate, we do its job, so it does not have to do anything. |
1492 | */ |
1493 | err = ntfs_resident_attr_value_resize(ctx->mrec, ctx->attr, |
1494 | attr_len); |
1495 | /* Shrinking cannot fail. */ |
1496 | BUG_ON(err); |
1497 | } |
1498 | addr = kmap_atomic(page, KM_USER0); |
1499 | /* Copy the data from the page to the mft record. */ |
1500 | memcpy((u8*)ctx->attr + |
1501 | le16_to_cpu(ctx->attr->data.resident.value_offset), |
1502 | addr, attr_len); |
1503 | /* Zero out of bounds area in the page cache page. */ |
1504 | memset(addr + attr_len, 0, PAGE_CACHE_SIZE - attr_len); |
1505 | kunmap_atomic(addr, KM_USER0); |
1506 | flush_dcache_page(page); |
1507 | flush_dcache_mft_record_page(ctx->ntfs_ino); |
1508 | /* We are done with the page. */ |
1509 | end_page_writeback(page); |
1510 | /* Finally, mark the mft record dirty, so it gets written back. */ |
1511 | mark_mft_record_dirty(ctx->ntfs_ino); |
1512 | ntfs_attr_put_search_ctx(ctx); |
1513 | unmap_mft_record(base_ni); |
1514 | return 0; |
1515 | err_out: |
1516 | if (err == -ENOMEM) { |
1517 | ntfs_warning(vi->i_sb, "Error allocating memory. Redirtying " |
1518 | "page so we try again later."); |
1519 | /* |
1520 | * Put the page back on mapping->dirty_pages, but leave its |
1521 | * buffers' dirty state as-is. |
1522 | */ |
1523 | redirty_page_for_writepage(wbc, page); |
1524 | err = 0; |
1525 | } else { |
1526 | ntfs_error(vi->i_sb, "Resident attribute write failed with " |
1527 | "error %i.", err); |
1528 | SetPageError(page); |
1529 | NVolSetErrors(ni->vol); |
1530 | } |
1531 | unlock_page(page); |
1532 | if (ctx) |
1533 | ntfs_attr_put_search_ctx(ctx); |
1534 | if (m) |
1535 | unmap_mft_record(base_ni); |
1536 | return err; |
1537 | } |
1538 | |
1539 | #endif /* NTFS_RW */ |
1540 | |
1541 | /** |
1542 | * ntfs_aops - general address space operations for inodes and attributes |
1543 | */ |
1544 | const struct address_space_operations ntfs_aops = { |
1545 | .readpage = ntfs_readpage, /* Fill page with data. */ |
1546 | #ifdef NTFS_RW |
1547 | .writepage = ntfs_writepage, /* Write dirty page to disk. */ |
1548 | #endif /* NTFS_RW */ |
1549 | .migratepage = buffer_migrate_page, /* Move a page cache page from |
1550 | one physical page to an |
1551 | other. */ |
1552 | .error_remove_page = generic_error_remove_page, |
1553 | }; |
1554 | |
1555 | /** |
1556 | * ntfs_mst_aops - general address space operations for mst protecteed inodes |
1557 | * and attributes |
1558 | */ |
1559 | const struct address_space_operations ntfs_mst_aops = { |
1560 | .readpage = ntfs_readpage, /* Fill page with data. */ |
1561 | #ifdef NTFS_RW |
1562 | .writepage = ntfs_writepage, /* Write dirty page to disk. */ |
1563 | .set_page_dirty = __set_page_dirty_nobuffers, /* Set the page dirty |
1564 | without touching the buffers |
1565 | belonging to the page. */ |
1566 | #endif /* NTFS_RW */ |
1567 | .migratepage = buffer_migrate_page, /* Move a page cache page from |
1568 | one physical page to an |
1569 | other. */ |
1570 | .error_remove_page = generic_error_remove_page, |
1571 | }; |
1572 | |
1573 | #ifdef NTFS_RW |
1574 | |
1575 | /** |
1576 | * mark_ntfs_record_dirty - mark an ntfs record dirty |
1577 | * @page: page containing the ntfs record to mark dirty |
1578 | * @ofs: byte offset within @page at which the ntfs record begins |
1579 | * |
1580 | * Set the buffers and the page in which the ntfs record is located dirty. |
1581 | * |
1582 | * The latter also marks the vfs inode the ntfs record belongs to dirty |
1583 | * (I_DIRTY_PAGES only). |
1584 | * |
1585 | * If the page does not have buffers, we create them and set them uptodate. |
1586 | * The page may not be locked which is why we need to handle the buffers under |
1587 | * the mapping->private_lock. Once the buffers are marked dirty we no longer |
1588 | * need the lock since try_to_free_buffers() does not free dirty buffers. |
1589 | */ |
1590 | void mark_ntfs_record_dirty(struct page *page, const unsigned int ofs) { |
1591 | struct address_space *mapping = page->mapping; |
1592 | ntfs_inode *ni = NTFS_I(mapping->host); |
1593 | struct buffer_head *bh, *head, *buffers_to_free = NULL; |
1594 | unsigned int end, bh_size, bh_ofs; |
1595 | |
1596 | BUG_ON(!PageUptodate(page)); |
1597 | end = ofs + ni->itype.index.block_size; |
1598 | bh_size = VFS_I(ni)->i_sb->s_blocksize; |
1599 | spin_lock(&mapping->private_lock); |
1600 | if (unlikely(!page_has_buffers(page))) { |
1601 | spin_unlock(&mapping->private_lock); |
1602 | bh = head = alloc_page_buffers(page, bh_size, 1); |
1603 | spin_lock(&mapping->private_lock); |
1604 | if (likely(!page_has_buffers(page))) { |
1605 | struct buffer_head *tail; |
1606 | |
1607 | do { |
1608 | set_buffer_uptodate(bh); |
1609 | tail = bh; |
1610 | bh = bh->b_this_page; |
1611 | } while (bh); |
1612 | tail->b_this_page = head; |
1613 | attach_page_buffers(page, head); |
1614 | } else |
1615 | buffers_to_free = bh; |
1616 | } |
1617 | bh = head = page_buffers(page); |
1618 | BUG_ON(!bh); |
1619 | do { |
1620 | bh_ofs = bh_offset(bh); |
1621 | if (bh_ofs + bh_size <= ofs) |
1622 | continue; |
1623 | if (unlikely(bh_ofs >= end)) |
1624 | break; |
1625 | set_buffer_dirty(bh); |
1626 | } while ((bh = bh->b_this_page) != head); |
1627 | spin_unlock(&mapping->private_lock); |
1628 | __set_page_dirty_nobuffers(page); |
1629 | if (unlikely(buffers_to_free)) { |
1630 | do { |
1631 | bh = buffers_to_free->b_this_page; |
1632 | free_buffer_head(buffers_to_free); |
1633 | buffers_to_free = bh; |
1634 | } while (buffers_to_free); |
1635 | } |
1636 | } |
1637 | |
1638 | #endif /* NTFS_RW */ |
1639 |
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