Commit | Line | Data |
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1da177e4 LT |
1 | /** |
2 | * aops.c - NTFS kernel address space operations and page cache handling. | |
3 | * Part of the Linux-NTFS project. | |
4 | * | |
b6ad6c52 | 5 | * Copyright (c) 2001-2005 Anton Altaparmakov |
1da177e4 LT |
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/mm.h> | |
26 | #include <linux/pagemap.h> | |
27 | #include <linux/swap.h> | |
28 | #include <linux/buffer_head.h> | |
29 | #include <linux/writeback.h> | |
30 | ||
31 | #include "aops.h" | |
32 | #include "attrib.h" | |
33 | #include "debug.h" | |
34 | #include "inode.h" | |
35 | #include "mft.h" | |
36 | #include "runlist.h" | |
37 | #include "types.h" | |
38 | #include "ntfs.h" | |
39 | ||
40 | /** | |
41 | * ntfs_end_buffer_async_read - async io completion for reading attributes | |
42 | * @bh: buffer head on which io is completed | |
43 | * @uptodate: whether @bh is now uptodate or not | |
44 | * | |
45 | * Asynchronous I/O completion handler for reading pages belonging to the | |
46 | * attribute address space of an inode. The inodes can either be files or | |
47 | * directories or they can be fake inodes describing some attribute. | |
48 | * | |
49 | * If NInoMstProtected(), perform the post read mst fixups when all IO on the | |
50 | * page has been completed and mark the page uptodate or set the error bit on | |
51 | * the page. To determine the size of the records that need fixing up, we | |
52 | * cheat a little bit by setting the index_block_size in ntfs_inode to the ntfs | |
53 | * record size, and index_block_size_bits, to the log(base 2) of the ntfs | |
54 | * record size. | |
55 | */ | |
56 | static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate) | |
57 | { | |
58 | static DEFINE_SPINLOCK(page_uptodate_lock); | |
59 | unsigned long flags; | |
60 | struct buffer_head *tmp; | |
61 | struct page *page; | |
62 | ntfs_inode *ni; | |
63 | int page_uptodate = 1; | |
64 | ||
65 | page = bh->b_page; | |
66 | ni = NTFS_I(page->mapping->host); | |
67 | ||
68 | if (likely(uptodate)) { | |
07a4e2da | 69 | s64 file_ofs, initialized_size; |
1da177e4 LT |
70 | |
71 | set_buffer_uptodate(bh); | |
72 | ||
73 | file_ofs = ((s64)page->index << PAGE_CACHE_SHIFT) + | |
74 | bh_offset(bh); | |
07a4e2da AA |
75 | read_lock_irqsave(&ni->size_lock, flags); |
76 | initialized_size = ni->initialized_size; | |
77 | read_unlock_irqrestore(&ni->size_lock, flags); | |
1da177e4 | 78 | /* Check for the current buffer head overflowing. */ |
07a4e2da | 79 | if (file_ofs + bh->b_size > initialized_size) { |
1da177e4 LT |
80 | char *addr; |
81 | int ofs = 0; | |
82 | ||
07a4e2da AA |
83 | if (file_ofs < initialized_size) |
84 | ofs = initialized_size - file_ofs; | |
1da177e4 LT |
85 | addr = kmap_atomic(page, KM_BIO_SRC_IRQ); |
86 | memset(addr + bh_offset(bh) + ofs, 0, bh->b_size - ofs); | |
87 | flush_dcache_page(page); | |
88 | kunmap_atomic(addr, KM_BIO_SRC_IRQ); | |
89 | } | |
90 | } else { | |
91 | clear_buffer_uptodate(bh); | |
92 | ntfs_error(ni->vol->sb, "Buffer I/O error, logical block %llu.", | |
93 | (unsigned long long)bh->b_blocknr); | |
94 | SetPageError(page); | |
95 | } | |
96 | spin_lock_irqsave(&page_uptodate_lock, flags); | |
97 | clear_buffer_async_read(bh); | |
98 | unlock_buffer(bh); | |
99 | tmp = bh; | |
100 | do { | |
101 | if (!buffer_uptodate(tmp)) | |
102 | page_uptodate = 0; | |
103 | if (buffer_async_read(tmp)) { | |
104 | if (likely(buffer_locked(tmp))) | |
105 | goto still_busy; | |
106 | /* Async buffers must be locked. */ | |
107 | BUG(); | |
108 | } | |
109 | tmp = tmp->b_this_page; | |
110 | } while (tmp != bh); | |
111 | spin_unlock_irqrestore(&page_uptodate_lock, flags); | |
112 | /* | |
113 | * If none of the buffers had errors then we can set the page uptodate, | |
114 | * but we first have to perform the post read mst fixups, if the | |
115 | * attribute is mst protected, i.e. if NInoMstProteced(ni) is true. | |
116 | * Note we ignore fixup errors as those are detected when | |
117 | * map_mft_record() is called which gives us per record granularity | |
118 | * rather than per page granularity. | |
119 | */ | |
120 | if (!NInoMstProtected(ni)) { | |
121 | if (likely(page_uptodate && !PageError(page))) | |
122 | SetPageUptodate(page); | |
123 | } else { | |
124 | char *addr; | |
125 | unsigned int i, recs; | |
126 | u32 rec_size; | |
127 | ||
128 | rec_size = ni->itype.index.block_size; | |
129 | recs = PAGE_CACHE_SIZE / rec_size; | |
130 | /* Should have been verified before we got here... */ | |
131 | BUG_ON(!recs); | |
132 | addr = kmap_atomic(page, KM_BIO_SRC_IRQ); | |
133 | for (i = 0; i < recs; i++) | |
134 | post_read_mst_fixup((NTFS_RECORD*)(addr + | |
135 | i * rec_size), rec_size); | |
136 | flush_dcache_page(page); | |
137 | kunmap_atomic(addr, KM_BIO_SRC_IRQ); | |
b6ad6c52 | 138 | if (likely(page_uptodate && !PageError(page))) |
1da177e4 LT |
139 | SetPageUptodate(page); |
140 | } | |
141 | unlock_page(page); | |
142 | return; | |
143 | still_busy: | |
144 | spin_unlock_irqrestore(&page_uptodate_lock, flags); | |
145 | return; | |
146 | } | |
147 | ||
148 | /** | |
149 | * ntfs_read_block - fill a @page of an address space with data | |
150 | * @page: page cache page to fill with data | |
151 | * | |
152 | * Fill the page @page of the address space belonging to the @page->host inode. | |
153 | * We read each buffer asynchronously and when all buffers are read in, our io | |
154 | * completion handler ntfs_end_buffer_read_async(), if required, automatically | |
155 | * applies the mst fixups to the page before finally marking it uptodate and | |
156 | * unlocking it. | |
157 | * | |
158 | * We only enforce allocated_size limit because i_size is checked for in | |
159 | * generic_file_read(). | |
160 | * | |
161 | * Return 0 on success and -errno on error. | |
162 | * | |
163 | * Contains an adapted version of fs/buffer.c::block_read_full_page(). | |
164 | */ | |
165 | static int ntfs_read_block(struct page *page) | |
166 | { | |
167 | VCN vcn; | |
168 | LCN lcn; | |
169 | ntfs_inode *ni; | |
170 | ntfs_volume *vol; | |
171 | runlist_element *rl; | |
172 | struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE]; | |
173 | sector_t iblock, lblock, zblock; | |
07a4e2da | 174 | unsigned long flags; |
1da177e4 LT |
175 | unsigned int blocksize, vcn_ofs; |
176 | int i, nr; | |
177 | unsigned char blocksize_bits; | |
178 | ||
179 | ni = NTFS_I(page->mapping->host); | |
180 | vol = ni->vol; | |
181 | ||
182 | /* $MFT/$DATA must have its complete runlist in memory at all times. */ | |
183 | BUG_ON(!ni->runlist.rl && !ni->mft_no && !NInoAttr(ni)); | |
184 | ||
185 | blocksize_bits = VFS_I(ni)->i_blkbits; | |
186 | blocksize = 1 << blocksize_bits; | |
187 | ||
188 | if (!page_has_buffers(page)) | |
189 | create_empty_buffers(page, blocksize, 0); | |
190 | bh = head = page_buffers(page); | |
191 | if (unlikely(!bh)) { | |
192 | unlock_page(page); | |
193 | return -ENOMEM; | |
194 | } | |
195 | ||
196 | iblock = (s64)page->index << (PAGE_CACHE_SHIFT - blocksize_bits); | |
07a4e2da | 197 | read_lock_irqsave(&ni->size_lock, flags); |
1da177e4 LT |
198 | lblock = (ni->allocated_size + blocksize - 1) >> blocksize_bits; |
199 | zblock = (ni->initialized_size + blocksize - 1) >> blocksize_bits; | |
07a4e2da | 200 | read_unlock_irqrestore(&ni->size_lock, flags); |
1da177e4 LT |
201 | |
202 | /* Loop through all the buffers in the page. */ | |
203 | rl = NULL; | |
204 | nr = i = 0; | |
205 | do { | |
206 | u8 *kaddr; | |
207 | ||
208 | if (unlikely(buffer_uptodate(bh))) | |
209 | continue; | |
210 | if (unlikely(buffer_mapped(bh))) { | |
211 | arr[nr++] = bh; | |
212 | continue; | |
213 | } | |
214 | bh->b_bdev = vol->sb->s_bdev; | |
215 | /* Is the block within the allowed limits? */ | |
216 | if (iblock < lblock) { | |
217 | BOOL is_retry = FALSE; | |
218 | ||
219 | /* Convert iblock into corresponding vcn and offset. */ | |
220 | vcn = (VCN)iblock << blocksize_bits >> | |
221 | vol->cluster_size_bits; | |
222 | vcn_ofs = ((VCN)iblock << blocksize_bits) & | |
223 | vol->cluster_size_mask; | |
224 | if (!rl) { | |
225 | lock_retry_remap: | |
226 | down_read(&ni->runlist.lock); | |
227 | rl = ni->runlist.rl; | |
228 | } | |
229 | if (likely(rl != NULL)) { | |
230 | /* Seek to element containing target vcn. */ | |
231 | while (rl->length && rl[1].vcn <= vcn) | |
232 | rl++; | |
233 | lcn = ntfs_rl_vcn_to_lcn(rl, vcn); | |
234 | } else | |
235 | lcn = LCN_RL_NOT_MAPPED; | |
236 | /* Successful remap. */ | |
237 | if (lcn >= 0) { | |
238 | /* Setup buffer head to correct block. */ | |
239 | bh->b_blocknr = ((lcn << vol->cluster_size_bits) | |
240 | + vcn_ofs) >> blocksize_bits; | |
241 | set_buffer_mapped(bh); | |
242 | /* Only read initialized data blocks. */ | |
243 | if (iblock < zblock) { | |
244 | arr[nr++] = bh; | |
245 | continue; | |
246 | } | |
247 | /* Fully non-initialized data block, zero it. */ | |
248 | goto handle_zblock; | |
249 | } | |
250 | /* It is a hole, need to zero it. */ | |
251 | if (lcn == LCN_HOLE) | |
252 | goto handle_hole; | |
253 | /* If first try and runlist unmapped, map and retry. */ | |
254 | if (!is_retry && lcn == LCN_RL_NOT_MAPPED) { | |
255 | int err; | |
256 | is_retry = TRUE; | |
257 | /* | |
258 | * Attempt to map runlist, dropping lock for | |
259 | * the duration. | |
260 | */ | |
261 | up_read(&ni->runlist.lock); | |
262 | err = ntfs_map_runlist(ni, vcn); | |
263 | if (likely(!err)) | |
264 | goto lock_retry_remap; | |
265 | rl = NULL; | |
266 | lcn = err; | |
9f993fe4 AA |
267 | } else if (!rl) |
268 | up_read(&ni->runlist.lock); | |
1da177e4 LT |
269 | /* Hard error, zero out region. */ |
270 | bh->b_blocknr = -1; | |
271 | SetPageError(page); | |
272 | ntfs_error(vol->sb, "Failed to read from inode 0x%lx, " | |
273 | "attribute type 0x%x, vcn 0x%llx, " | |
274 | "offset 0x%x because its location on " | |
275 | "disk could not be determined%s " | |
276 | "(error code %lli).", ni->mft_no, | |
277 | ni->type, (unsigned long long)vcn, | |
278 | vcn_ofs, is_retry ? " even after " | |
279 | "retrying" : "", (long long)lcn); | |
280 | } | |
281 | /* | |
282 | * Either iblock was outside lblock limits or | |
283 | * ntfs_rl_vcn_to_lcn() returned error. Just zero that portion | |
284 | * of the page and set the buffer uptodate. | |
285 | */ | |
286 | handle_hole: | |
287 | bh->b_blocknr = -1UL; | |
288 | clear_buffer_mapped(bh); | |
289 | handle_zblock: | |
290 | kaddr = kmap_atomic(page, KM_USER0); | |
291 | memset(kaddr + i * blocksize, 0, blocksize); | |
292 | flush_dcache_page(page); | |
293 | kunmap_atomic(kaddr, KM_USER0); | |
294 | set_buffer_uptodate(bh); | |
295 | } while (i++, iblock++, (bh = bh->b_this_page) != head); | |
296 | ||
297 | /* Release the lock if we took it. */ | |
298 | if (rl) | |
299 | up_read(&ni->runlist.lock); | |
300 | ||
301 | /* Check we have at least one buffer ready for i/o. */ | |
302 | if (nr) { | |
303 | struct buffer_head *tbh; | |
304 | ||
305 | /* Lock the buffers. */ | |
306 | for (i = 0; i < nr; i++) { | |
307 | tbh = arr[i]; | |
308 | lock_buffer(tbh); | |
309 | tbh->b_end_io = ntfs_end_buffer_async_read; | |
310 | set_buffer_async_read(tbh); | |
311 | } | |
312 | /* Finally, start i/o on the buffers. */ | |
313 | for (i = 0; i < nr; i++) { | |
314 | tbh = arr[i]; | |
315 | if (likely(!buffer_uptodate(tbh))) | |
316 | submit_bh(READ, tbh); | |
317 | else | |
318 | ntfs_end_buffer_async_read(tbh, 1); | |
319 | } | |
320 | return 0; | |
321 | } | |
322 | /* No i/o was scheduled on any of the buffers. */ | |
323 | if (likely(!PageError(page))) | |
324 | SetPageUptodate(page); | |
325 | else /* Signal synchronous i/o error. */ | |
326 | nr = -EIO; | |
327 | unlock_page(page); | |
328 | return nr; | |
329 | } | |
330 | ||
331 | /** | |
332 | * ntfs_readpage - fill a @page of a @file with data from the device | |
333 | * @file: open file to which the page @page belongs or NULL | |
334 | * @page: page cache page to fill with data | |
335 | * | |
336 | * For non-resident attributes, ntfs_readpage() fills the @page of the open | |
337 | * file @file by calling the ntfs version of the generic block_read_full_page() | |
338 | * function, ntfs_read_block(), which in turn creates and reads in the buffers | |
339 | * associated with the page asynchronously. | |
340 | * | |
341 | * For resident attributes, OTOH, ntfs_readpage() fills @page by copying the | |
342 | * data from the mft record (which at this stage is most likely in memory) and | |
343 | * fills the remainder with zeroes. Thus, in this case, I/O is synchronous, as | |
344 | * even if the mft record is not cached at this point in time, we need to wait | |
345 | * for it to be read in before we can do the copy. | |
346 | * | |
347 | * Return 0 on success and -errno on error. | |
348 | */ | |
349 | static int ntfs_readpage(struct file *file, struct page *page) | |
350 | { | |
1da177e4 LT |
351 | ntfs_inode *ni, *base_ni; |
352 | u8 *kaddr; | |
353 | ntfs_attr_search_ctx *ctx; | |
354 | MFT_RECORD *mrec; | |
b6ad6c52 | 355 | unsigned long flags; |
1da177e4 LT |
356 | u32 attr_len; |
357 | int err = 0; | |
358 | ||
905685f6 | 359 | retry_readpage: |
1da177e4 LT |
360 | BUG_ON(!PageLocked(page)); |
361 | /* | |
362 | * This can potentially happen because we clear PageUptodate() during | |
363 | * ntfs_writepage() of MstProtected() attributes. | |
364 | */ | |
365 | if (PageUptodate(page)) { | |
366 | unlock_page(page); | |
367 | return 0; | |
368 | } | |
369 | ni = NTFS_I(page->mapping->host); | |
370 | ||
371 | /* NInoNonResident() == NInoIndexAllocPresent() */ | |
372 | if (NInoNonResident(ni)) { | |
373 | /* | |
374 | * Only unnamed $DATA attributes can be compressed or | |
375 | * encrypted. | |
376 | */ | |
377 | if (ni->type == AT_DATA && !ni->name_len) { | |
378 | /* If file is encrypted, deny access, just like NT4. */ | |
379 | if (NInoEncrypted(ni)) { | |
380 | err = -EACCES; | |
381 | goto err_out; | |
382 | } | |
383 | /* Compressed data streams are handled in compress.c. */ | |
384 | if (NInoCompressed(ni)) | |
385 | return ntfs_read_compressed_block(page); | |
386 | } | |
387 | /* Normal data stream. */ | |
388 | return ntfs_read_block(page); | |
389 | } | |
390 | /* | |
391 | * Attribute is resident, implying it is not compressed or encrypted. | |
392 | * This also means the attribute is smaller than an mft record and | |
393 | * hence smaller than a page, so can simply zero out any pages with | |
b6ad6c52 | 394 | * index above 0. |
1da177e4 | 395 | */ |
b6ad6c52 | 396 | if (unlikely(page->index > 0)) { |
1da177e4 LT |
397 | kaddr = kmap_atomic(page, KM_USER0); |
398 | memset(kaddr, 0, PAGE_CACHE_SIZE); | |
399 | flush_dcache_page(page); | |
400 | kunmap_atomic(kaddr, KM_USER0); | |
401 | goto done; | |
402 | } | |
403 | if (!NInoAttr(ni)) | |
404 | base_ni = ni; | |
405 | else | |
406 | base_ni = ni->ext.base_ntfs_ino; | |
407 | /* Map, pin, and lock the mft record. */ | |
408 | mrec = map_mft_record(base_ni); | |
409 | if (IS_ERR(mrec)) { | |
410 | err = PTR_ERR(mrec); | |
411 | goto err_out; | |
412 | } | |
905685f6 AA |
413 | /* |
414 | * If a parallel write made the attribute non-resident, drop the mft | |
415 | * record and retry the readpage. | |
416 | */ | |
417 | if (unlikely(NInoNonResident(ni))) { | |
418 | unmap_mft_record(base_ni); | |
419 | goto retry_readpage; | |
420 | } | |
1da177e4 LT |
421 | ctx = ntfs_attr_get_search_ctx(base_ni, mrec); |
422 | if (unlikely(!ctx)) { | |
423 | err = -ENOMEM; | |
424 | goto unm_err_out; | |
425 | } | |
426 | err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, | |
427 | CASE_SENSITIVE, 0, NULL, 0, ctx); | |
428 | if (unlikely(err)) | |
429 | goto put_unm_err_out; | |
430 | attr_len = le32_to_cpu(ctx->attr->data.resident.value_length); | |
b6ad6c52 AA |
431 | read_lock_irqsave(&ni->size_lock, flags); |
432 | if (unlikely(attr_len > ni->initialized_size)) | |
433 | attr_len = ni->initialized_size; | |
434 | read_unlock_irqrestore(&ni->size_lock, flags); | |
1da177e4 LT |
435 | kaddr = kmap_atomic(page, KM_USER0); |
436 | /* Copy the data to the page. */ | |
437 | memcpy(kaddr, (u8*)ctx->attr + | |
438 | le16_to_cpu(ctx->attr->data.resident.value_offset), | |
439 | attr_len); | |
440 | /* Zero the remainder of the page. */ | |
441 | memset(kaddr + attr_len, 0, PAGE_CACHE_SIZE - attr_len); | |
442 | flush_dcache_page(page); | |
443 | kunmap_atomic(kaddr, KM_USER0); | |
444 | put_unm_err_out: | |
445 | ntfs_attr_put_search_ctx(ctx); | |
446 | unm_err_out: | |
447 | unmap_mft_record(base_ni); | |
448 | done: | |
449 | SetPageUptodate(page); | |
450 | err_out: | |
451 | unlock_page(page); | |
452 | return err; | |
453 | } | |
454 | ||
455 | #ifdef NTFS_RW | |
456 | ||
457 | /** | |
458 | * ntfs_write_block - write a @page to the backing store | |
459 | * @page: page cache page to write out | |
460 | * @wbc: writeback control structure | |
461 | * | |
462 | * This function is for writing pages belonging to non-resident, non-mst | |
463 | * protected attributes to their backing store. | |
464 | * | |
465 | * For a page with buffers, map and write the dirty buffers asynchronously | |
466 | * under page writeback. For a page without buffers, create buffers for the | |
467 | * page, then proceed as above. | |
468 | * | |
469 | * If a page doesn't have buffers the page dirty state is definitive. If a page | |
470 | * does have buffers, the page dirty state is just a hint, and the buffer dirty | |
471 | * state is definitive. (A hint which has rules: dirty buffers against a clean | |
472 | * page is illegal. Other combinations are legal and need to be handled. In | |
473 | * particular a dirty page containing clean buffers for example.) | |
474 | * | |
475 | * Return 0 on success and -errno on error. | |
476 | * | |
477 | * Based on ntfs_read_block() and __block_write_full_page(). | |
478 | */ | |
479 | static int ntfs_write_block(struct page *page, struct writeback_control *wbc) | |
480 | { | |
481 | VCN vcn; | |
482 | LCN lcn; | |
07a4e2da AA |
483 | s64 initialized_size; |
484 | loff_t i_size; | |
1da177e4 LT |
485 | sector_t block, dblock, iblock; |
486 | struct inode *vi; | |
487 | ntfs_inode *ni; | |
488 | ntfs_volume *vol; | |
489 | runlist_element *rl; | |
490 | struct buffer_head *bh, *head; | |
07a4e2da | 491 | unsigned long flags; |
1da177e4 LT |
492 | unsigned int blocksize, vcn_ofs; |
493 | int err; | |
494 | BOOL need_end_writeback; | |
495 | unsigned char blocksize_bits; | |
496 | ||
497 | vi = page->mapping->host; | |
498 | ni = NTFS_I(vi); | |
499 | vol = ni->vol; | |
500 | ||
501 | ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index " | |
502 | "0x%lx.", ni->mft_no, ni->type, page->index); | |
503 | ||
504 | BUG_ON(!NInoNonResident(ni)); | |
505 | BUG_ON(NInoMstProtected(ni)); | |
506 | ||
507 | blocksize_bits = vi->i_blkbits; | |
508 | blocksize = 1 << blocksize_bits; | |
509 | ||
510 | if (!page_has_buffers(page)) { | |
511 | BUG_ON(!PageUptodate(page)); | |
512 | create_empty_buffers(page, blocksize, | |
513 | (1 << BH_Uptodate) | (1 << BH_Dirty)); | |
514 | } | |
515 | bh = head = page_buffers(page); | |
516 | if (unlikely(!bh)) { | |
517 | ntfs_warning(vol->sb, "Error allocating page buffers. " | |
518 | "Redirtying page so we try again later."); | |
519 | /* | |
520 | * Put the page back on mapping->dirty_pages, but leave its | |
521 | * buffer's dirty state as-is. | |
522 | */ | |
523 | redirty_page_for_writepage(wbc, page); | |
524 | unlock_page(page); | |
525 | return 0; | |
526 | } | |
527 | ||
528 | /* NOTE: Different naming scheme to ntfs_read_block()! */ | |
529 | ||
530 | /* The first block in the page. */ | |
531 | block = (s64)page->index << (PAGE_CACHE_SHIFT - blocksize_bits); | |
532 | ||
07a4e2da AA |
533 | read_lock_irqsave(&ni->size_lock, flags); |
534 | i_size = i_size_read(vi); | |
535 | initialized_size = ni->initialized_size; | |
536 | read_unlock_irqrestore(&ni->size_lock, flags); | |
537 | ||
1da177e4 | 538 | /* The first out of bounds block for the data size. */ |
07a4e2da | 539 | dblock = (i_size + blocksize - 1) >> blocksize_bits; |
1da177e4 LT |
540 | |
541 | /* The last (fully or partially) initialized block. */ | |
07a4e2da | 542 | iblock = initialized_size >> blocksize_bits; |
1da177e4 LT |
543 | |
544 | /* | |
545 | * Be very careful. We have no exclusion from __set_page_dirty_buffers | |
546 | * here, and the (potentially unmapped) buffers may become dirty at | |
547 | * any time. If a buffer becomes dirty here after we've inspected it | |
548 | * then we just miss that fact, and the page stays dirty. | |
549 | * | |
550 | * Buffers outside i_size may be dirtied by __set_page_dirty_buffers; | |
551 | * handle that here by just cleaning them. | |
552 | */ | |
553 | ||
554 | /* | |
555 | * Loop through all the buffers in the page, mapping all the dirty | |
556 | * buffers to disk addresses and handling any aliases from the | |
557 | * underlying block device's mapping. | |
558 | */ | |
559 | rl = NULL; | |
560 | err = 0; | |
561 | do { | |
562 | BOOL is_retry = FALSE; | |
563 | ||
564 | if (unlikely(block >= dblock)) { | |
565 | /* | |
566 | * Mapped buffers outside i_size will occur, because | |
567 | * this page can be outside i_size when there is a | |
568 | * truncate in progress. The contents of such buffers | |
569 | * were zeroed by ntfs_writepage(). | |
570 | * | |
571 | * FIXME: What about the small race window where | |
572 | * ntfs_writepage() has not done any clearing because | |
573 | * the page was within i_size but before we get here, | |
574 | * vmtruncate() modifies i_size? | |
575 | */ | |
576 | clear_buffer_dirty(bh); | |
577 | set_buffer_uptodate(bh); | |
578 | continue; | |
579 | } | |
580 | ||
581 | /* Clean buffers are not written out, so no need to map them. */ | |
582 | if (!buffer_dirty(bh)) | |
583 | continue; | |
584 | ||
585 | /* Make sure we have enough initialized size. */ | |
586 | if (unlikely((block >= iblock) && | |
07a4e2da | 587 | (initialized_size < i_size))) { |
1da177e4 LT |
588 | /* |
589 | * If this page is fully outside initialized size, zero | |
590 | * out all pages between the current initialized size | |
591 | * and the current page. Just use ntfs_readpage() to do | |
592 | * the zeroing transparently. | |
593 | */ | |
594 | if (block > iblock) { | |
595 | // TODO: | |
596 | // For each page do: | |
597 | // - read_cache_page() | |
598 | // Again for each page do: | |
599 | // - wait_on_page_locked() | |
600 | // - Check (PageUptodate(page) && | |
601 | // !PageError(page)) | |
602 | // Update initialized size in the attribute and | |
603 | // in the inode. | |
604 | // Again, for each page do: | |
605 | // __set_page_dirty_buffers(); | |
606 | // page_cache_release() | |
607 | // We don't need to wait on the writes. | |
608 | // Update iblock. | |
609 | } | |
610 | /* | |
611 | * The current page straddles initialized size. Zero | |
612 | * all non-uptodate buffers and set them uptodate (and | |
613 | * dirty?). Note, there aren't any non-uptodate buffers | |
614 | * if the page is uptodate. | |
615 | * FIXME: For an uptodate page, the buffers may need to | |
616 | * be written out because they were not initialized on | |
617 | * disk before. | |
618 | */ | |
619 | if (!PageUptodate(page)) { | |
620 | // TODO: | |
621 | // Zero any non-uptodate buffers up to i_size. | |
622 | // Set them uptodate and dirty. | |
623 | } | |
624 | // TODO: | |
625 | // Update initialized size in the attribute and in the | |
626 | // inode (up to i_size). | |
627 | // Update iblock. | |
628 | // FIXME: This is inefficient. Try to batch the two | |
629 | // size changes to happen in one go. | |
630 | ntfs_error(vol->sb, "Writing beyond initialized size " | |
631 | "is not supported yet. Sorry."); | |
632 | err = -EOPNOTSUPP; | |
633 | break; | |
634 | // Do NOT set_buffer_new() BUT DO clear buffer range | |
635 | // outside write request range. | |
636 | // set_buffer_uptodate() on complete buffers as well as | |
637 | // set_buffer_dirty(). | |
638 | } | |
639 | ||
640 | /* No need to map buffers that are already mapped. */ | |
641 | if (buffer_mapped(bh)) | |
642 | continue; | |
643 | ||
644 | /* Unmapped, dirty buffer. Need to map it. */ | |
645 | bh->b_bdev = vol->sb->s_bdev; | |
646 | ||
647 | /* Convert block into corresponding vcn and offset. */ | |
648 | vcn = (VCN)block << blocksize_bits; | |
649 | vcn_ofs = vcn & vol->cluster_size_mask; | |
650 | vcn >>= vol->cluster_size_bits; | |
651 | if (!rl) { | |
652 | lock_retry_remap: | |
653 | down_read(&ni->runlist.lock); | |
654 | rl = ni->runlist.rl; | |
655 | } | |
656 | if (likely(rl != NULL)) { | |
657 | /* Seek to element containing target vcn. */ | |
658 | while (rl->length && rl[1].vcn <= vcn) | |
659 | rl++; | |
660 | lcn = ntfs_rl_vcn_to_lcn(rl, vcn); | |
661 | } else | |
662 | lcn = LCN_RL_NOT_MAPPED; | |
663 | /* Successful remap. */ | |
664 | if (lcn >= 0) { | |
665 | /* Setup buffer head to point to correct block. */ | |
666 | bh->b_blocknr = ((lcn << vol->cluster_size_bits) + | |
667 | vcn_ofs) >> blocksize_bits; | |
668 | set_buffer_mapped(bh); | |
669 | continue; | |
670 | } | |
671 | /* It is a hole, need to instantiate it. */ | |
672 | if (lcn == LCN_HOLE) { | |
673 | // TODO: Instantiate the hole. | |
674 | // clear_buffer_new(bh); | |
675 | // unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); | |
676 | ntfs_error(vol->sb, "Writing into sparse regions is " | |
677 | "not supported yet. Sorry."); | |
678 | err = -EOPNOTSUPP; | |
679 | break; | |
680 | } | |
681 | /* If first try and runlist unmapped, map and retry. */ | |
682 | if (!is_retry && lcn == LCN_RL_NOT_MAPPED) { | |
683 | is_retry = TRUE; | |
684 | /* | |
685 | * Attempt to map runlist, dropping lock for | |
686 | * the duration. | |
687 | */ | |
688 | up_read(&ni->runlist.lock); | |
689 | err = ntfs_map_runlist(ni, vcn); | |
690 | if (likely(!err)) | |
691 | goto lock_retry_remap; | |
692 | rl = NULL; | |
693 | lcn = err; | |
9f993fe4 AA |
694 | } else if (!rl) |
695 | up_read(&ni->runlist.lock); | |
1da177e4 LT |
696 | /* Failed to map the buffer, even after retrying. */ |
697 | bh->b_blocknr = -1; | |
698 | ntfs_error(vol->sb, "Failed to write to inode 0x%lx, " | |
699 | "attribute type 0x%x, vcn 0x%llx, offset 0x%x " | |
700 | "because its location on disk could not be " | |
701 | "determined%s (error code %lli).", ni->mft_no, | |
702 | ni->type, (unsigned long long)vcn, | |
703 | vcn_ofs, is_retry ? " even after " | |
704 | "retrying" : "", (long long)lcn); | |
705 | if (!err) | |
706 | err = -EIO; | |
707 | break; | |
708 | } while (block++, (bh = bh->b_this_page) != head); | |
709 | ||
710 | /* Release the lock if we took it. */ | |
711 | if (rl) | |
712 | up_read(&ni->runlist.lock); | |
713 | ||
714 | /* For the error case, need to reset bh to the beginning. */ | |
715 | bh = head; | |
716 | ||
717 | /* Just an optimization, so ->readpage() isn't called later. */ | |
718 | if (unlikely(!PageUptodate(page))) { | |
719 | int uptodate = 1; | |
720 | do { | |
721 | if (!buffer_uptodate(bh)) { | |
722 | uptodate = 0; | |
723 | bh = head; | |
724 | break; | |
725 | } | |
726 | } while ((bh = bh->b_this_page) != head); | |
727 | if (uptodate) | |
728 | SetPageUptodate(page); | |
729 | } | |
730 | ||
731 | /* Setup all mapped, dirty buffers for async write i/o. */ | |
732 | do { | |
733 | get_bh(bh); | |
734 | if (buffer_mapped(bh) && buffer_dirty(bh)) { | |
735 | lock_buffer(bh); | |
736 | if (test_clear_buffer_dirty(bh)) { | |
737 | BUG_ON(!buffer_uptodate(bh)); | |
738 | mark_buffer_async_write(bh); | |
739 | } else | |
740 | unlock_buffer(bh); | |
741 | } else if (unlikely(err)) { | |
742 | /* | |
743 | * For the error case. The buffer may have been set | |
744 | * dirty during attachment to a dirty page. | |
745 | */ | |
746 | if (err != -ENOMEM) | |
747 | clear_buffer_dirty(bh); | |
748 | } | |
749 | } while ((bh = bh->b_this_page) != head); | |
750 | ||
751 | if (unlikely(err)) { | |
752 | // TODO: Remove the -EOPNOTSUPP check later on... | |
753 | if (unlikely(err == -EOPNOTSUPP)) | |
754 | err = 0; | |
755 | else if (err == -ENOMEM) { | |
756 | ntfs_warning(vol->sb, "Error allocating memory. " | |
757 | "Redirtying page so we try again " | |
758 | "later."); | |
759 | /* | |
760 | * Put the page back on mapping->dirty_pages, but | |
761 | * leave its buffer's dirty state as-is. | |
762 | */ | |
763 | redirty_page_for_writepage(wbc, page); | |
764 | err = 0; | |
765 | } else | |
766 | SetPageError(page); | |
767 | } | |
768 | ||
769 | BUG_ON(PageWriteback(page)); | |
770 | set_page_writeback(page); /* Keeps try_to_free_buffers() away. */ | |
771 | unlock_page(page); | |
772 | ||
773 | /* | |
774 | * Submit the prepared buffers for i/o. Note the page is unlocked, | |
775 | * and the async write i/o completion handler can end_page_writeback() | |
776 | * at any time after the *first* submit_bh(). So the buffers can then | |
777 | * disappear... | |
778 | */ | |
779 | need_end_writeback = TRUE; | |
780 | do { | |
781 | struct buffer_head *next = bh->b_this_page; | |
782 | if (buffer_async_write(bh)) { | |
783 | submit_bh(WRITE, bh); | |
784 | need_end_writeback = FALSE; | |
785 | } | |
786 | put_bh(bh); | |
787 | bh = next; | |
788 | } while (bh != head); | |
789 | ||
790 | /* If no i/o was started, need to end_page_writeback(). */ | |
791 | if (unlikely(need_end_writeback)) | |
792 | end_page_writeback(page); | |
793 | ||
794 | ntfs_debug("Done."); | |
795 | return err; | |
796 | } | |
797 | ||
798 | /** | |
799 | * ntfs_write_mst_block - write a @page to the backing store | |
800 | * @page: page cache page to write out | |
801 | * @wbc: writeback control structure | |
802 | * | |
803 | * This function is for writing pages belonging to non-resident, mst protected | |
804 | * attributes to their backing store. The only supported attributes are index | |
805 | * allocation and $MFT/$DATA. Both directory inodes and index inodes are | |
806 | * supported for the index allocation case. | |
807 | * | |
808 | * The page must remain locked for the duration of the write because we apply | |
809 | * the mst fixups, write, and then undo the fixups, so if we were to unlock the | |
810 | * page before undoing the fixups, any other user of the page will see the | |
811 | * page contents as corrupt. | |
812 | * | |
813 | * We clear the page uptodate flag for the duration of the function to ensure | |
814 | * exclusion for the $MFT/$DATA case against someone mapping an mft record we | |
815 | * are about to apply the mst fixups to. | |
816 | * | |
817 | * Return 0 on success and -errno on error. | |
818 | * | |
819 | * Based on ntfs_write_block(), ntfs_mft_writepage(), and | |
820 | * write_mft_record_nolock(). | |
821 | */ | |
822 | static int ntfs_write_mst_block(struct page *page, | |
823 | struct writeback_control *wbc) | |
824 | { | |
825 | sector_t block, dblock, rec_block; | |
826 | struct inode *vi = page->mapping->host; | |
827 | ntfs_inode *ni = NTFS_I(vi); | |
828 | ntfs_volume *vol = ni->vol; | |
829 | u8 *kaddr; | |
1da177e4 LT |
830 | unsigned int rec_size = ni->itype.index.block_size; |
831 | ntfs_inode *locked_nis[PAGE_CACHE_SIZE / rec_size]; | |
832 | struct buffer_head *bh, *head, *tbh, *rec_start_bh; | |
d53ee322 | 833 | struct buffer_head *bhs[MAX_BUF_PER_PAGE]; |
1da177e4 | 834 | runlist_element *rl; |
d53ee322 AA |
835 | int i, nr_locked_nis, nr_recs, nr_bhs, max_bhs, bhs_per_rec, err, err2; |
836 | unsigned bh_size, rec_size_bits; | |
1da177e4 | 837 | BOOL sync, is_mft, page_is_dirty, rec_is_dirty; |
d53ee322 | 838 | unsigned char bh_size_bits; |
1da177e4 LT |
839 | |
840 | ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index " | |
841 | "0x%lx.", vi->i_ino, ni->type, page->index); | |
842 | BUG_ON(!NInoNonResident(ni)); | |
843 | BUG_ON(!NInoMstProtected(ni)); | |
844 | is_mft = (S_ISREG(vi->i_mode) && !vi->i_ino); | |
845 | /* | |
846 | * NOTE: ntfs_write_mst_block() would be called for $MFTMirr if a page | |
847 | * in its page cache were to be marked dirty. However this should | |
848 | * never happen with the current driver and considering we do not | |
849 | * handle this case here we do want to BUG(), at least for now. | |
850 | */ | |
851 | BUG_ON(!(is_mft || S_ISDIR(vi->i_mode) || | |
852 | (NInoAttr(ni) && ni->type == AT_INDEX_ALLOCATION))); | |
d53ee322 AA |
853 | bh_size_bits = vi->i_blkbits; |
854 | bh_size = 1 << bh_size_bits; | |
855 | max_bhs = PAGE_CACHE_SIZE / bh_size; | |
1da177e4 | 856 | BUG_ON(!max_bhs); |
d53ee322 | 857 | BUG_ON(max_bhs > MAX_BUF_PER_PAGE); |
1da177e4 LT |
858 | |
859 | /* Were we called for sync purposes? */ | |
860 | sync = (wbc->sync_mode == WB_SYNC_ALL); | |
861 | ||
862 | /* Make sure we have mapped buffers. */ | |
863 | BUG_ON(!page_has_buffers(page)); | |
864 | bh = head = page_buffers(page); | |
865 | BUG_ON(!bh); | |
866 | ||
867 | rec_size_bits = ni->itype.index.block_size_bits; | |
868 | BUG_ON(!(PAGE_CACHE_SIZE >> rec_size_bits)); | |
869 | bhs_per_rec = rec_size >> bh_size_bits; | |
870 | BUG_ON(!bhs_per_rec); | |
871 | ||
872 | /* The first block in the page. */ | |
873 | rec_block = block = (sector_t)page->index << | |
874 | (PAGE_CACHE_SHIFT - bh_size_bits); | |
875 | ||
876 | /* The first out of bounds block for the data size. */ | |
07a4e2da | 877 | dblock = (i_size_read(vi) + bh_size - 1) >> bh_size_bits; |
1da177e4 LT |
878 | |
879 | rl = NULL; | |
880 | err = err2 = nr_bhs = nr_recs = nr_locked_nis = 0; | |
881 | page_is_dirty = rec_is_dirty = FALSE; | |
882 | rec_start_bh = NULL; | |
883 | do { | |
884 | BOOL is_retry = FALSE; | |
885 | ||
886 | if (likely(block < rec_block)) { | |
887 | if (unlikely(block >= dblock)) { | |
888 | clear_buffer_dirty(bh); | |
946929d8 | 889 | set_buffer_uptodate(bh); |
1da177e4 LT |
890 | continue; |
891 | } | |
892 | /* | |
893 | * This block is not the first one in the record. We | |
894 | * ignore the buffer's dirty state because we could | |
895 | * have raced with a parallel mark_ntfs_record_dirty(). | |
896 | */ | |
897 | if (!rec_is_dirty) | |
898 | continue; | |
899 | if (unlikely(err2)) { | |
900 | if (err2 != -ENOMEM) | |
901 | clear_buffer_dirty(bh); | |
902 | continue; | |
903 | } | |
904 | } else /* if (block == rec_block) */ { | |
905 | BUG_ON(block > rec_block); | |
906 | /* This block is the first one in the record. */ | |
907 | rec_block += bhs_per_rec; | |
908 | err2 = 0; | |
909 | if (unlikely(block >= dblock)) { | |
910 | clear_buffer_dirty(bh); | |
911 | continue; | |
912 | } | |
913 | if (!buffer_dirty(bh)) { | |
914 | /* Clean records are not written out. */ | |
915 | rec_is_dirty = FALSE; | |
916 | continue; | |
917 | } | |
918 | rec_is_dirty = TRUE; | |
919 | rec_start_bh = bh; | |
920 | } | |
921 | /* Need to map the buffer if it is not mapped already. */ | |
922 | if (unlikely(!buffer_mapped(bh))) { | |
923 | VCN vcn; | |
924 | LCN lcn; | |
925 | unsigned int vcn_ofs; | |
926 | ||
927 | /* Obtain the vcn and offset of the current block. */ | |
928 | vcn = (VCN)block << bh_size_bits; | |
929 | vcn_ofs = vcn & vol->cluster_size_mask; | |
930 | vcn >>= vol->cluster_size_bits; | |
931 | if (!rl) { | |
932 | lock_retry_remap: | |
933 | down_read(&ni->runlist.lock); | |
934 | rl = ni->runlist.rl; | |
935 | } | |
936 | if (likely(rl != NULL)) { | |
937 | /* Seek to element containing target vcn. */ | |
938 | while (rl->length && rl[1].vcn <= vcn) | |
939 | rl++; | |
940 | lcn = ntfs_rl_vcn_to_lcn(rl, vcn); | |
941 | } else | |
942 | lcn = LCN_RL_NOT_MAPPED; | |
943 | /* Successful remap. */ | |
944 | if (likely(lcn >= 0)) { | |
945 | /* Setup buffer head to correct block. */ | |
946 | bh->b_blocknr = ((lcn << | |
947 | vol->cluster_size_bits) + | |
948 | vcn_ofs) >> bh_size_bits; | |
949 | set_buffer_mapped(bh); | |
950 | } else { | |
951 | /* | |
952 | * Remap failed. Retry to map the runlist once | |
953 | * unless we are working on $MFT which always | |
954 | * has the whole of its runlist in memory. | |
955 | */ | |
956 | if (!is_mft && !is_retry && | |
957 | lcn == LCN_RL_NOT_MAPPED) { | |
958 | is_retry = TRUE; | |
959 | /* | |
960 | * Attempt to map runlist, dropping | |
961 | * lock for the duration. | |
962 | */ | |
963 | up_read(&ni->runlist.lock); | |
964 | err2 = ntfs_map_runlist(ni, vcn); | |
965 | if (likely(!err2)) | |
966 | goto lock_retry_remap; | |
967 | if (err2 == -ENOMEM) | |
968 | page_is_dirty = TRUE; | |
969 | lcn = err2; | |
9f993fe4 | 970 | } else { |
1da177e4 | 971 | err2 = -EIO; |
9f993fe4 AA |
972 | if (!rl) |
973 | up_read(&ni->runlist.lock); | |
974 | } | |
1da177e4 LT |
975 | /* Hard error. Abort writing this record. */ |
976 | if (!err || err == -ENOMEM) | |
977 | err = err2; | |
978 | bh->b_blocknr = -1; | |
979 | ntfs_error(vol->sb, "Cannot write ntfs record " | |
980 | "0x%llx (inode 0x%lx, " | |
981 | "attribute type 0x%x) because " | |
982 | "its location on disk could " | |
983 | "not be determined (error " | |
8907547d RD |
984 | "code %lli).", |
985 | (long long)block << | |
1da177e4 LT |
986 | bh_size_bits >> |
987 | vol->mft_record_size_bits, | |
988 | ni->mft_no, ni->type, | |
989 | (long long)lcn); | |
990 | /* | |
991 | * If this is not the first buffer, remove the | |
992 | * buffers in this record from the list of | |
993 | * buffers to write and clear their dirty bit | |
994 | * if not error -ENOMEM. | |
995 | */ | |
996 | if (rec_start_bh != bh) { | |
997 | while (bhs[--nr_bhs] != rec_start_bh) | |
998 | ; | |
999 | if (err2 != -ENOMEM) { | |
1000 | do { | |
1001 | clear_buffer_dirty( | |
1002 | rec_start_bh); | |
1003 | } while ((rec_start_bh = | |
1004 | rec_start_bh-> | |
1005 | b_this_page) != | |
1006 | bh); | |
1007 | } | |
1008 | } | |
1009 | continue; | |
1010 | } | |
1011 | } | |
1012 | BUG_ON(!buffer_uptodate(bh)); | |
1013 | BUG_ON(nr_bhs >= max_bhs); | |
1014 | bhs[nr_bhs++] = bh; | |
1015 | } while (block++, (bh = bh->b_this_page) != head); | |
1016 | if (unlikely(rl)) | |
1017 | up_read(&ni->runlist.lock); | |
1018 | /* If there were no dirty buffers, we are done. */ | |
1019 | if (!nr_bhs) | |
1020 | goto done; | |
1021 | /* Map the page so we can access its contents. */ | |
1022 | kaddr = kmap(page); | |
1023 | /* Clear the page uptodate flag whilst the mst fixups are applied. */ | |
1024 | BUG_ON(!PageUptodate(page)); | |
1025 | ClearPageUptodate(page); | |
1026 | for (i = 0; i < nr_bhs; i++) { | |
1027 | unsigned int ofs; | |
1028 | ||
1029 | /* Skip buffers which are not at the beginning of records. */ | |
1030 | if (i % bhs_per_rec) | |
1031 | continue; | |
1032 | tbh = bhs[i]; | |
1033 | ofs = bh_offset(tbh); | |
1034 | if (is_mft) { | |
1035 | ntfs_inode *tni; | |
1036 | unsigned long mft_no; | |
1037 | ||
1038 | /* Get the mft record number. */ | |
1039 | mft_no = (((s64)page->index << PAGE_CACHE_SHIFT) + ofs) | |
1040 | >> rec_size_bits; | |
1041 | /* Check whether to write this mft record. */ | |
1042 | tni = NULL; | |
1043 | if (!ntfs_may_write_mft_record(vol, mft_no, | |
1044 | (MFT_RECORD*)(kaddr + ofs), &tni)) { | |
1045 | /* | |
1046 | * The record should not be written. This | |
1047 | * means we need to redirty the page before | |
1048 | * returning. | |
1049 | */ | |
1050 | page_is_dirty = TRUE; | |
1051 | /* | |
1052 | * Remove the buffers in this mft record from | |
1053 | * the list of buffers to write. | |
1054 | */ | |
1055 | do { | |
1056 | bhs[i] = NULL; | |
1057 | } while (++i % bhs_per_rec); | |
1058 | continue; | |
1059 | } | |
1060 | /* | |
1061 | * The record should be written. If a locked ntfs | |
1062 | * inode was returned, add it to the array of locked | |
1063 | * ntfs inodes. | |
1064 | */ | |
1065 | if (tni) | |
1066 | locked_nis[nr_locked_nis++] = tni; | |
1067 | } | |
1068 | /* Apply the mst protection fixups. */ | |
1069 | err2 = pre_write_mst_fixup((NTFS_RECORD*)(kaddr + ofs), | |
1070 | rec_size); | |
1071 | if (unlikely(err2)) { | |
1072 | if (!err || err == -ENOMEM) | |
1073 | err = -EIO; | |
1074 | ntfs_error(vol->sb, "Failed to apply mst fixups " | |
1075 | "(inode 0x%lx, attribute type 0x%x, " | |
1076 | "page index 0x%lx, page offset 0x%x)!" | |
1077 | " Unmount and run chkdsk.", vi->i_ino, | |
1078 | ni->type, page->index, ofs); | |
1079 | /* | |
1080 | * Mark all the buffers in this record clean as we do | |
1081 | * not want to write corrupt data to disk. | |
1082 | */ | |
1083 | do { | |
1084 | clear_buffer_dirty(bhs[i]); | |
1085 | bhs[i] = NULL; | |
1086 | } while (++i % bhs_per_rec); | |
1087 | continue; | |
1088 | } | |
1089 | nr_recs++; | |
1090 | } | |
1091 | /* If no records are to be written out, we are done. */ | |
1092 | if (!nr_recs) | |
1093 | goto unm_done; | |
1094 | flush_dcache_page(page); | |
1095 | /* Lock buffers and start synchronous write i/o on them. */ | |
1096 | for (i = 0; i < nr_bhs; i++) { | |
1097 | tbh = bhs[i]; | |
1098 | if (!tbh) | |
1099 | continue; | |
1100 | if (unlikely(test_set_buffer_locked(tbh))) | |
1101 | BUG(); | |
1102 | /* The buffer dirty state is now irrelevant, just clean it. */ | |
1103 | clear_buffer_dirty(tbh); | |
1104 | BUG_ON(!buffer_uptodate(tbh)); | |
1105 | BUG_ON(!buffer_mapped(tbh)); | |
1106 | get_bh(tbh); | |
1107 | tbh->b_end_io = end_buffer_write_sync; | |
1108 | submit_bh(WRITE, tbh); | |
1109 | } | |
1110 | /* Synchronize the mft mirror now if not @sync. */ | |
1111 | if (is_mft && !sync) | |
1112 | goto do_mirror; | |
1113 | do_wait: | |
1114 | /* Wait on i/o completion of buffers. */ | |
1115 | for (i = 0; i < nr_bhs; i++) { | |
1116 | tbh = bhs[i]; | |
1117 | if (!tbh) | |
1118 | continue; | |
1119 | wait_on_buffer(tbh); | |
1120 | if (unlikely(!buffer_uptodate(tbh))) { | |
1121 | ntfs_error(vol->sb, "I/O error while writing ntfs " | |
1122 | "record buffer (inode 0x%lx, " | |
1123 | "attribute type 0x%x, page index " | |
1124 | "0x%lx, page offset 0x%lx)! Unmount " | |
1125 | "and run chkdsk.", vi->i_ino, ni->type, | |
1126 | page->index, bh_offset(tbh)); | |
1127 | if (!err || err == -ENOMEM) | |
1128 | err = -EIO; | |
1129 | /* | |
1130 | * Set the buffer uptodate so the page and buffer | |
1131 | * states do not become out of sync. | |
1132 | */ | |
1133 | set_buffer_uptodate(tbh); | |
1134 | } | |
1135 | } | |
1136 | /* If @sync, now synchronize the mft mirror. */ | |
1137 | if (is_mft && sync) { | |
1138 | do_mirror: | |
1139 | for (i = 0; i < nr_bhs; i++) { | |
1140 | unsigned long mft_no; | |
1141 | unsigned int ofs; | |
1142 | ||
1143 | /* | |
1144 | * Skip buffers which are not at the beginning of | |
1145 | * records. | |
1146 | */ | |
1147 | if (i % bhs_per_rec) | |
1148 | continue; | |
1149 | tbh = bhs[i]; | |
1150 | /* Skip removed buffers (and hence records). */ | |
1151 | if (!tbh) | |
1152 | continue; | |
1153 | ofs = bh_offset(tbh); | |
1154 | /* Get the mft record number. */ | |
1155 | mft_no = (((s64)page->index << PAGE_CACHE_SHIFT) + ofs) | |
1156 | >> rec_size_bits; | |
1157 | if (mft_no < vol->mftmirr_size) | |
1158 | ntfs_sync_mft_mirror(vol, mft_no, | |
1159 | (MFT_RECORD*)(kaddr + ofs), | |
1160 | sync); | |
1161 | } | |
1162 | if (!sync) | |
1163 | goto do_wait; | |
1164 | } | |
1165 | /* Remove the mst protection fixups again. */ | |
1166 | for (i = 0; i < nr_bhs; i++) { | |
1167 | if (!(i % bhs_per_rec)) { | |
1168 | tbh = bhs[i]; | |
1169 | if (!tbh) | |
1170 | continue; | |
1171 | post_write_mst_fixup((NTFS_RECORD*)(kaddr + | |
1172 | bh_offset(tbh))); | |
1173 | } | |
1174 | } | |
1175 | flush_dcache_page(page); | |
1176 | unm_done: | |
1177 | /* Unlock any locked inodes. */ | |
1178 | while (nr_locked_nis-- > 0) { | |
1179 | ntfs_inode *tni, *base_tni; | |
1180 | ||
1181 | tni = locked_nis[nr_locked_nis]; | |
1182 | /* Get the base inode. */ | |
1183 | down(&tni->extent_lock); | |
1184 | if (tni->nr_extents >= 0) | |
1185 | base_tni = tni; | |
1186 | else { | |
1187 | base_tni = tni->ext.base_ntfs_ino; | |
1188 | BUG_ON(!base_tni); | |
1189 | } | |
1190 | up(&tni->extent_lock); | |
1191 | ntfs_debug("Unlocking %s inode 0x%lx.", | |
1192 | tni == base_tni ? "base" : "extent", | |
1193 | tni->mft_no); | |
1194 | up(&tni->mrec_lock); | |
1195 | atomic_dec(&tni->count); | |
1196 | iput(VFS_I(base_tni)); | |
1197 | } | |
1198 | SetPageUptodate(page); | |
1199 | kunmap(page); | |
1200 | done: | |
1201 | if (unlikely(err && err != -ENOMEM)) { | |
1202 | /* | |
1203 | * Set page error if there is only one ntfs record in the page. | |
1204 | * Otherwise we would loose per-record granularity. | |
1205 | */ | |
1206 | if (ni->itype.index.block_size == PAGE_CACHE_SIZE) | |
1207 | SetPageError(page); | |
1208 | NVolSetErrors(vol); | |
1209 | } | |
1210 | if (page_is_dirty) { | |
1211 | ntfs_debug("Page still contains one or more dirty ntfs " | |
1212 | "records. Redirtying the page starting at " | |
1213 | "record 0x%lx.", page->index << | |
1214 | (PAGE_CACHE_SHIFT - rec_size_bits)); | |
1215 | redirty_page_for_writepage(wbc, page); | |
1216 | unlock_page(page); | |
1217 | } else { | |
1218 | /* | |
1219 | * Keep the VM happy. This must be done otherwise the | |
1220 | * radix-tree tag PAGECACHE_TAG_DIRTY remains set even though | |
1221 | * the page is clean. | |
1222 | */ | |
1223 | BUG_ON(PageWriteback(page)); | |
1224 | set_page_writeback(page); | |
1225 | unlock_page(page); | |
1226 | end_page_writeback(page); | |
1227 | } | |
1228 | if (likely(!err)) | |
1229 | ntfs_debug("Done."); | |
1230 | return err; | |
1231 | } | |
1232 | ||
1233 | /** | |
1234 | * ntfs_writepage - write a @page to the backing store | |
1235 | * @page: page cache page to write out | |
1236 | * @wbc: writeback control structure | |
1237 | * | |
1238 | * This is called from the VM when it wants to have a dirty ntfs page cache | |
1239 | * page cleaned. The VM has already locked the page and marked it clean. | |
1240 | * | |
1241 | * For non-resident attributes, ntfs_writepage() writes the @page by calling | |
1242 | * the ntfs version of the generic block_write_full_page() function, | |
1243 | * ntfs_write_block(), which in turn if necessary creates and writes the | |
1244 | * buffers associated with the page asynchronously. | |
1245 | * | |
1246 | * For resident attributes, OTOH, ntfs_writepage() writes the @page by copying | |
1247 | * the data to the mft record (which at this stage is most likely in memory). | |
1248 | * The mft record is then marked dirty and written out asynchronously via the | |
1249 | * vfs inode dirty code path for the inode the mft record belongs to or via the | |
1250 | * vm page dirty code path for the page the mft record is in. | |
1251 | * | |
1252 | * Based on ntfs_readpage() and fs/buffer.c::block_write_full_page(). | |
1253 | * | |
1254 | * Return 0 on success and -errno on error. | |
1255 | */ | |
1256 | static int ntfs_writepage(struct page *page, struct writeback_control *wbc) | |
1257 | { | |
1258 | loff_t i_size; | |
149f0c52 AA |
1259 | struct inode *vi = page->mapping->host; |
1260 | ntfs_inode *base_ni = NULL, *ni = NTFS_I(vi); | |
1da177e4 | 1261 | char *kaddr; |
149f0c52 AA |
1262 | ntfs_attr_search_ctx *ctx = NULL; |
1263 | MFT_RECORD *m = NULL; | |
1da177e4 LT |
1264 | u32 attr_len; |
1265 | int err; | |
1266 | ||
905685f6 | 1267 | retry_writepage: |
1da177e4 | 1268 | BUG_ON(!PageLocked(page)); |
1da177e4 | 1269 | i_size = i_size_read(vi); |
1da177e4 LT |
1270 | /* Is the page fully outside i_size? (truncate in progress) */ |
1271 | if (unlikely(page->index >= (i_size + PAGE_CACHE_SIZE - 1) >> | |
1272 | PAGE_CACHE_SHIFT)) { | |
1273 | /* | |
1274 | * The page may have dirty, unmapped buffers. Make them | |
1275 | * freeable here, so the page does not leak. | |
1276 | */ | |
1277 | block_invalidatepage(page, 0); | |
1278 | unlock_page(page); | |
1279 | ntfs_debug("Write outside i_size - truncated?"); | |
1280 | return 0; | |
1281 | } | |
1da177e4 LT |
1282 | /* NInoNonResident() == NInoIndexAllocPresent() */ |
1283 | if (NInoNonResident(ni)) { | |
1284 | /* | |
1285 | * Only unnamed $DATA attributes can be compressed, encrypted, | |
1286 | * and/or sparse. | |
1287 | */ | |
1288 | if (ni->type == AT_DATA && !ni->name_len) { | |
1289 | /* If file is encrypted, deny access, just like NT4. */ | |
1290 | if (NInoEncrypted(ni)) { | |
1291 | unlock_page(page); | |
1292 | ntfs_debug("Denying write access to encrypted " | |
1293 | "file."); | |
1294 | return -EACCES; | |
1295 | } | |
1296 | /* Compressed data streams are handled in compress.c. */ | |
1297 | if (NInoCompressed(ni)) { | |
1298 | // TODO: Implement and replace this check with | |
1299 | // return ntfs_write_compressed_block(page); | |
1300 | unlock_page(page); | |
1301 | ntfs_error(vi->i_sb, "Writing to compressed " | |
1302 | "files is not supported yet. " | |
1303 | "Sorry."); | |
1304 | return -EOPNOTSUPP; | |
1305 | } | |
1306 | // TODO: Implement and remove this check. | |
1307 | if (NInoSparse(ni)) { | |
1308 | unlock_page(page); | |
1309 | ntfs_error(vi->i_sb, "Writing to sparse files " | |
1310 | "is not supported yet. Sorry."); | |
1311 | return -EOPNOTSUPP; | |
1312 | } | |
1313 | } | |
1314 | /* We have to zero every time due to mmap-at-end-of-file. */ | |
1315 | if (page->index >= (i_size >> PAGE_CACHE_SHIFT)) { | |
1316 | /* The page straddles i_size. */ | |
1317 | unsigned int ofs = i_size & ~PAGE_CACHE_MASK; | |
1318 | kaddr = kmap_atomic(page, KM_USER0); | |
1319 | memset(kaddr + ofs, 0, PAGE_CACHE_SIZE - ofs); | |
1320 | flush_dcache_page(page); | |
1321 | kunmap_atomic(kaddr, KM_USER0); | |
1322 | } | |
1323 | /* Handle mst protected attributes. */ | |
1324 | if (NInoMstProtected(ni)) | |
1325 | return ntfs_write_mst_block(page, wbc); | |
1326 | /* Normal data stream. */ | |
1327 | return ntfs_write_block(page, wbc); | |
1328 | } | |
1329 | /* | |
1330 | * Attribute is resident, implying it is not compressed, encrypted, | |
1331 | * sparse, or mst protected. This also means the attribute is smaller | |
1332 | * than an mft record and hence smaller than a page, so can simply | |
1333 | * return error on any pages with index above 0. | |
1334 | */ | |
1335 | BUG_ON(page_has_buffers(page)); | |
1336 | BUG_ON(!PageUptodate(page)); | |
1337 | if (unlikely(page->index > 0)) { | |
1338 | ntfs_error(vi->i_sb, "BUG()! page->index (0x%lx) > 0. " | |
1339 | "Aborting write.", page->index); | |
1340 | BUG_ON(PageWriteback(page)); | |
1341 | set_page_writeback(page); | |
1342 | unlock_page(page); | |
1343 | end_page_writeback(page); | |
1344 | return -EIO; | |
1345 | } | |
1346 | if (!NInoAttr(ni)) | |
1347 | base_ni = ni; | |
1348 | else | |
1349 | base_ni = ni->ext.base_ntfs_ino; | |
1350 | /* Map, pin, and lock the mft record. */ | |
1351 | m = map_mft_record(base_ni); | |
1352 | if (IS_ERR(m)) { | |
1353 | err = PTR_ERR(m); | |
1354 | m = NULL; | |
1355 | ctx = NULL; | |
1356 | goto err_out; | |
1357 | } | |
905685f6 AA |
1358 | /* |
1359 | * If a parallel write made the attribute non-resident, drop the mft | |
1360 | * record and retry the writepage. | |
1361 | */ | |
1362 | if (unlikely(NInoNonResident(ni))) { | |
1363 | unmap_mft_record(base_ni); | |
1364 | goto retry_writepage; | |
1365 | } | |
1da177e4 LT |
1366 | ctx = ntfs_attr_get_search_ctx(base_ni, m); |
1367 | if (unlikely(!ctx)) { | |
1368 | err = -ENOMEM; | |
1369 | goto err_out; | |
1370 | } | |
1371 | err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, | |
1372 | CASE_SENSITIVE, 0, NULL, 0, ctx); | |
1373 | if (unlikely(err)) | |
1374 | goto err_out; | |
1375 | /* | |
1376 | * Keep the VM happy. This must be done otherwise the radix-tree tag | |
1377 | * PAGECACHE_TAG_DIRTY remains set even though the page is clean. | |
1378 | */ | |
1379 | BUG_ON(PageWriteback(page)); | |
1380 | set_page_writeback(page); | |
1381 | unlock_page(page); | |
1382 | ||
1383 | /* | |
1384 | * Here, we don't need to zero the out of bounds area everytime because | |
1385 | * the below memcpy() already takes care of the mmap-at-end-of-file | |
1386 | * requirements. If the file is converted to a non-resident one, then | |
1387 | * the code path use is switched to the non-resident one where the | |
1388 | * zeroing happens on each ntfs_writepage() invocation. | |
1389 | * | |
1390 | * The above also applies nicely when i_size is decreased. | |
1391 | * | |
1392 | * When i_size is increased, the memory between the old and new i_size | |
1393 | * _must_ be zeroed (or overwritten with new data). Otherwise we will | |
1394 | * expose data to userspace/disk which should never have been exposed. | |
1395 | * | |
1396 | * FIXME: Ensure that i_size increases do the zeroing/overwriting and | |
1397 | * if we cannot guarantee that, then enable the zeroing below. If the | |
1398 | * zeroing below is enabled, we MUST move the unlock_page() from above | |
1399 | * to after the kunmap_atomic(), i.e. just before the | |
1400 | * end_page_writeback(). | |
1401 | * UPDATE: ntfs_prepare/commit_write() do the zeroing on i_size | |
1402 | * increases for resident attributes so those are ok. | |
1403 | * TODO: ntfs_truncate(), others? | |
1404 | */ | |
1405 | ||
1406 | attr_len = le32_to_cpu(ctx->attr->data.resident.value_length); | |
07a4e2da | 1407 | i_size = i_size_read(vi); |
1da177e4 | 1408 | if (unlikely(attr_len > i_size)) { |
1da177e4 | 1409 | attr_len = i_size; |
f40661be | 1410 | ctx->attr->data.resident.value_length = cpu_to_le32(attr_len); |
1da177e4 | 1411 | } |
f40661be | 1412 | kaddr = kmap_atomic(page, KM_USER0); |
1da177e4 LT |
1413 | /* Copy the data from the page to the mft record. */ |
1414 | memcpy((u8*)ctx->attr + | |
1415 | le16_to_cpu(ctx->attr->data.resident.value_offset), | |
1416 | kaddr, attr_len); | |
1417 | flush_dcache_mft_record_page(ctx->ntfs_ino); | |
1418 | /* Zero out of bounds area in the page cache page. */ | |
1419 | memset(kaddr + attr_len, 0, PAGE_CACHE_SIZE - attr_len); | |
1420 | flush_dcache_page(page); | |
1421 | kunmap_atomic(kaddr, KM_USER0); | |
1422 | ||
1423 | end_page_writeback(page); | |
1424 | ||
1425 | /* Mark the mft record dirty, so it gets written back. */ | |
1426 | mark_mft_record_dirty(ctx->ntfs_ino); | |
1427 | ntfs_attr_put_search_ctx(ctx); | |
1428 | unmap_mft_record(base_ni); | |
1429 | return 0; | |
1430 | err_out: | |
1431 | if (err == -ENOMEM) { | |
1432 | ntfs_warning(vi->i_sb, "Error allocating memory. Redirtying " | |
1433 | "page so we try again later."); | |
1434 | /* | |
1435 | * Put the page back on mapping->dirty_pages, but leave its | |
1436 | * buffers' dirty state as-is. | |
1437 | */ | |
1438 | redirty_page_for_writepage(wbc, page); | |
1439 | err = 0; | |
1440 | } else { | |
1441 | ntfs_error(vi->i_sb, "Resident attribute write failed with " | |
149f0c52 | 1442 | "error %i.", err); |
1da177e4 | 1443 | SetPageError(page); |
149f0c52 AA |
1444 | NVolSetErrors(ni->vol); |
1445 | make_bad_inode(vi); | |
1da177e4 LT |
1446 | } |
1447 | unlock_page(page); | |
1448 | if (ctx) | |
1449 | ntfs_attr_put_search_ctx(ctx); | |
1450 | if (m) | |
1451 | unmap_mft_record(base_ni); | |
1452 | return err; | |
1453 | } | |
1454 | ||
1455 | /** | |
1456 | * ntfs_prepare_nonresident_write - | |
1457 | * | |
1458 | */ | |
1459 | static int ntfs_prepare_nonresident_write(struct page *page, | |
1460 | unsigned from, unsigned to) | |
1461 | { | |
1462 | VCN vcn; | |
1463 | LCN lcn; | |
07a4e2da AA |
1464 | s64 initialized_size; |
1465 | loff_t i_size; | |
1da177e4 LT |
1466 | sector_t block, ablock, iblock; |
1467 | struct inode *vi; | |
1468 | ntfs_inode *ni; | |
1469 | ntfs_volume *vol; | |
1470 | runlist_element *rl; | |
1471 | struct buffer_head *bh, *head, *wait[2], **wait_bh = wait; | |
07a4e2da | 1472 | unsigned long flags; |
1da177e4 LT |
1473 | unsigned int vcn_ofs, block_start, block_end, blocksize; |
1474 | int err; | |
1475 | BOOL is_retry; | |
1476 | unsigned char blocksize_bits; | |
1477 | ||
1478 | vi = page->mapping->host; | |
1479 | ni = NTFS_I(vi); | |
1480 | vol = ni->vol; | |
1481 | ||
1482 | ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index " | |
1483 | "0x%lx, from = %u, to = %u.", ni->mft_no, ni->type, | |
1484 | page->index, from, to); | |
1485 | ||
1486 | BUG_ON(!NInoNonResident(ni)); | |
1487 | ||
1488 | blocksize_bits = vi->i_blkbits; | |
1489 | blocksize = 1 << blocksize_bits; | |
1490 | ||
1491 | /* | |
1492 | * create_empty_buffers() will create uptodate/dirty buffers if the | |
1493 | * page is uptodate/dirty. | |
1494 | */ | |
1495 | if (!page_has_buffers(page)) | |
1496 | create_empty_buffers(page, blocksize, 0); | |
1497 | bh = head = page_buffers(page); | |
1498 | if (unlikely(!bh)) | |
1499 | return -ENOMEM; | |
1500 | ||
1501 | /* The first block in the page. */ | |
1502 | block = (s64)page->index << (PAGE_CACHE_SHIFT - blocksize_bits); | |
1503 | ||
07a4e2da | 1504 | read_lock_irqsave(&ni->size_lock, flags); |
1da177e4 | 1505 | /* |
b6ad6c52 | 1506 | * The first out of bounds block for the allocated size. No need to |
1da177e4 LT |
1507 | * round up as allocated_size is in multiples of cluster size and the |
1508 | * minimum cluster size is 512 bytes, which is equal to the smallest | |
1509 | * blocksize. | |
1510 | */ | |
1511 | ablock = ni->allocated_size >> blocksize_bits; | |
07a4e2da AA |
1512 | i_size = i_size_read(vi); |
1513 | initialized_size = ni->initialized_size; | |
1514 | read_unlock_irqrestore(&ni->size_lock, flags); | |
1515 | ||
1da177e4 | 1516 | /* The last (fully or partially) initialized block. */ |
07a4e2da | 1517 | iblock = initialized_size >> blocksize_bits; |
1da177e4 LT |
1518 | |
1519 | /* Loop through all the buffers in the page. */ | |
1520 | block_start = 0; | |
1521 | rl = NULL; | |
1522 | err = 0; | |
1523 | do { | |
1524 | block_end = block_start + blocksize; | |
1525 | /* | |
1526 | * If buffer @bh is outside the write, just mark it uptodate | |
1527 | * if the page is uptodate and continue with the next buffer. | |
1528 | */ | |
1529 | if (block_end <= from || block_start >= to) { | |
1530 | if (PageUptodate(page)) { | |
1531 | if (!buffer_uptodate(bh)) | |
1532 | set_buffer_uptodate(bh); | |
1533 | } | |
1534 | continue; | |
1535 | } | |
1536 | /* | |
1537 | * @bh is at least partially being written to. | |
1538 | * Make sure it is not marked as new. | |
1539 | */ | |
1540 | //if (buffer_new(bh)) | |
1541 | // clear_buffer_new(bh); | |
1542 | ||
1543 | if (block >= ablock) { | |
1544 | // TODO: block is above allocated_size, need to | |
1545 | // allocate it. Best done in one go to accommodate not | |
1546 | // only block but all above blocks up to and including: | |
1547 | // ((page->index << PAGE_CACHE_SHIFT) + to + blocksize | |
1548 | // - 1) >> blobksize_bits. Obviously will need to round | |
1549 | // up to next cluster boundary, too. This should be | |
1550 | // done with a helper function, so it can be reused. | |
1551 | ntfs_error(vol->sb, "Writing beyond allocated size " | |
1552 | "is not supported yet. Sorry."); | |
1553 | err = -EOPNOTSUPP; | |
1554 | goto err_out; | |
1555 | // Need to update ablock. | |
1556 | // Need to set_buffer_new() on all block bhs that are | |
1557 | // newly allocated. | |
1558 | } | |
1559 | /* | |
1560 | * Now we have enough allocated size to fulfill the whole | |
1561 | * request, i.e. block < ablock is true. | |
1562 | */ | |
1563 | if (unlikely((block >= iblock) && | |
07a4e2da | 1564 | (initialized_size < i_size))) { |
1da177e4 LT |
1565 | /* |
1566 | * If this page is fully outside initialized size, zero | |
1567 | * out all pages between the current initialized size | |
1568 | * and the current page. Just use ntfs_readpage() to do | |
1569 | * the zeroing transparently. | |
1570 | */ | |
1571 | if (block > iblock) { | |
1572 | // TODO: | |
1573 | // For each page do: | |
1574 | // - read_cache_page() | |
1575 | // Again for each page do: | |
1576 | // - wait_on_page_locked() | |
1577 | // - Check (PageUptodate(page) && | |
1578 | // !PageError(page)) | |
1579 | // Update initialized size in the attribute and | |
1580 | // in the inode. | |
1581 | // Again, for each page do: | |
1582 | // __set_page_dirty_buffers(); | |
1583 | // page_cache_release() | |
1584 | // We don't need to wait on the writes. | |
1585 | // Update iblock. | |
1586 | } | |
1587 | /* | |
1588 | * The current page straddles initialized size. Zero | |
1589 | * all non-uptodate buffers and set them uptodate (and | |
1590 | * dirty?). Note, there aren't any non-uptodate buffers | |
1591 | * if the page is uptodate. | |
1592 | * FIXME: For an uptodate page, the buffers may need to | |
1593 | * be written out because they were not initialized on | |
1594 | * disk before. | |
1595 | */ | |
1596 | if (!PageUptodate(page)) { | |
1597 | // TODO: | |
1598 | // Zero any non-uptodate buffers up to i_size. | |
1599 | // Set them uptodate and dirty. | |
1600 | } | |
1601 | // TODO: | |
1602 | // Update initialized size in the attribute and in the | |
1603 | // inode (up to i_size). | |
1604 | // Update iblock. | |
1605 | // FIXME: This is inefficient. Try to batch the two | |
1606 | // size changes to happen in one go. | |
1607 | ntfs_error(vol->sb, "Writing beyond initialized size " | |
1608 | "is not supported yet. Sorry."); | |
1609 | err = -EOPNOTSUPP; | |
1610 | goto err_out; | |
1611 | // Do NOT set_buffer_new() BUT DO clear buffer range | |
1612 | // outside write request range. | |
1613 | // set_buffer_uptodate() on complete buffers as well as | |
1614 | // set_buffer_dirty(). | |
1615 | } | |
1616 | ||
1617 | /* Need to map unmapped buffers. */ | |
1618 | if (!buffer_mapped(bh)) { | |
1619 | /* Unmapped buffer. Need to map it. */ | |
1620 | bh->b_bdev = vol->sb->s_bdev; | |
1621 | ||
1622 | /* Convert block into corresponding vcn and offset. */ | |
1623 | vcn = (VCN)block << blocksize_bits >> | |
1624 | vol->cluster_size_bits; | |
1625 | vcn_ofs = ((VCN)block << blocksize_bits) & | |
1626 | vol->cluster_size_mask; | |
1627 | ||
1628 | is_retry = FALSE; | |
1629 | if (!rl) { | |
1630 | lock_retry_remap: | |
1631 | down_read(&ni->runlist.lock); | |
1632 | rl = ni->runlist.rl; | |
1633 | } | |
1634 | if (likely(rl != NULL)) { | |
1635 | /* Seek to element containing target vcn. */ | |
1636 | while (rl->length && rl[1].vcn <= vcn) | |
1637 | rl++; | |
1638 | lcn = ntfs_rl_vcn_to_lcn(rl, vcn); | |
1639 | } else | |
1640 | lcn = LCN_RL_NOT_MAPPED; | |
1641 | if (unlikely(lcn < 0)) { | |
1642 | /* | |
1643 | * We extended the attribute allocation above. | |
1644 | * If we hit an ENOENT here it means that the | |
1645 | * allocation was insufficient which is a bug. | |
1646 | */ | |
1647 | BUG_ON(lcn == LCN_ENOENT); | |
1648 | ||
1649 | /* It is a hole, need to instantiate it. */ | |
1650 | if (lcn == LCN_HOLE) { | |
1651 | // TODO: Instantiate the hole. | |
1652 | // clear_buffer_new(bh); | |
1653 | // unmap_underlying_metadata(bh->b_bdev, | |
1654 | // bh->b_blocknr); | |
1655 | // For non-uptodate buffers, need to | |
1656 | // zero out the region outside the | |
1657 | // request in this bh or all bhs, | |
1658 | // depending on what we implemented | |
1659 | // above. | |
1660 | // Need to flush_dcache_page(). | |
1661 | // Or could use set_buffer_new() | |
1662 | // instead? | |
1663 | ntfs_error(vol->sb, "Writing into " | |
1664 | "sparse regions is " | |
1665 | "not supported yet. " | |
1666 | "Sorry."); | |
1667 | err = -EOPNOTSUPP; | |
9f993fe4 AA |
1668 | if (!rl) |
1669 | up_read(&ni->runlist.lock); | |
1da177e4 LT |
1670 | goto err_out; |
1671 | } else if (!is_retry && | |
1672 | lcn == LCN_RL_NOT_MAPPED) { | |
1673 | is_retry = TRUE; | |
1674 | /* | |
1675 | * Attempt to map runlist, dropping | |
1676 | * lock for the duration. | |
1677 | */ | |
1678 | up_read(&ni->runlist.lock); | |
1679 | err = ntfs_map_runlist(ni, vcn); | |
1680 | if (likely(!err)) | |
1681 | goto lock_retry_remap; | |
1682 | rl = NULL; | |
1683 | lcn = err; | |
9f993fe4 AA |
1684 | } else if (!rl) |
1685 | up_read(&ni->runlist.lock); | |
1da177e4 LT |
1686 | /* |
1687 | * Failed to map the buffer, even after | |
1688 | * retrying. | |
1689 | */ | |
1690 | bh->b_blocknr = -1; | |
1691 | ntfs_error(vol->sb, "Failed to write to inode " | |
1692 | "0x%lx, attribute type 0x%x, " | |
1693 | "vcn 0x%llx, offset 0x%x " | |
1694 | "because its location on disk " | |
1695 | "could not be determined%s " | |
1696 | "(error code %lli).", | |
1697 | ni->mft_no, ni->type, | |
1698 | (unsigned long long)vcn, | |
1699 | vcn_ofs, is_retry ? " even " | |
1700 | "after retrying" : "", | |
1701 | (long long)lcn); | |
1702 | if (!err) | |
1703 | err = -EIO; | |
1704 | goto err_out; | |
1705 | } | |
1706 | /* We now have a successful remap, i.e. lcn >= 0. */ | |
1707 | ||
1708 | /* Setup buffer head to correct block. */ | |
1709 | bh->b_blocknr = ((lcn << vol->cluster_size_bits) | |
1710 | + vcn_ofs) >> blocksize_bits; | |
1711 | set_buffer_mapped(bh); | |
1712 | ||
1713 | // FIXME: Something analogous to this is needed for | |
1714 | // each newly allocated block, i.e. BH_New. | |
1715 | // FIXME: Might need to take this out of the | |
1716 | // if (!buffer_mapped(bh)) {}, depending on how we | |
1717 | // implement things during the allocated_size and | |
1718 | // initialized_size extension code above. | |
1719 | if (buffer_new(bh)) { | |
1720 | clear_buffer_new(bh); | |
1721 | unmap_underlying_metadata(bh->b_bdev, | |
1722 | bh->b_blocknr); | |
1723 | if (PageUptodate(page)) { | |
1724 | set_buffer_uptodate(bh); | |
1725 | continue; | |
1726 | } | |
1727 | /* | |
1728 | * Page is _not_ uptodate, zero surrounding | |
1729 | * region. NOTE: This is how we decide if to | |
1730 | * zero or not! | |
1731 | */ | |
1732 | if (block_end > to || block_start < from) { | |
1733 | void *kaddr; | |
1734 | ||
1735 | kaddr = kmap_atomic(page, KM_USER0); | |
1736 | if (block_end > to) | |
1737 | memset(kaddr + to, 0, | |
1738 | block_end - to); | |
1739 | if (block_start < from) | |
1740 | memset(kaddr + block_start, 0, | |
1741 | from - | |
1742 | block_start); | |
1743 | flush_dcache_page(page); | |
1744 | kunmap_atomic(kaddr, KM_USER0); | |
1745 | } | |
1746 | continue; | |
1747 | } | |
1748 | } | |
1749 | /* @bh is mapped, set it uptodate if the page is uptodate. */ | |
1750 | if (PageUptodate(page)) { | |
1751 | if (!buffer_uptodate(bh)) | |
1752 | set_buffer_uptodate(bh); | |
1753 | continue; | |
1754 | } | |
1755 | /* | |
1756 | * The page is not uptodate. The buffer is mapped. If it is not | |
1757 | * uptodate, and it is only partially being written to, we need | |
1758 | * to read the buffer in before the write, i.e. right now. | |
1759 | */ | |
1760 | if (!buffer_uptodate(bh) && | |
1761 | (block_start < from || block_end > to)) { | |
1762 | ll_rw_block(READ, 1, &bh); | |
1763 | *wait_bh++ = bh; | |
1764 | } | |
1765 | } while (block++, block_start = block_end, | |
1766 | (bh = bh->b_this_page) != head); | |
1767 | ||
1768 | /* Release the lock if we took it. */ | |
1769 | if (rl) { | |
1770 | up_read(&ni->runlist.lock); | |
1771 | rl = NULL; | |
1772 | } | |
1773 | ||
1774 | /* If we issued read requests, let them complete. */ | |
1775 | while (wait_bh > wait) { | |
1776 | wait_on_buffer(*--wait_bh); | |
1777 | if (!buffer_uptodate(*wait_bh)) | |
1778 | return -EIO; | |
1779 | } | |
1780 | ||
1781 | ntfs_debug("Done."); | |
1782 | return 0; | |
1783 | err_out: | |
1784 | /* | |
1785 | * Zero out any newly allocated blocks to avoid exposing stale data. | |
1786 | * If BH_New is set, we know that the block was newly allocated in the | |
1787 | * above loop. | |
1788 | * FIXME: What about initialized_size increments? Have we done all the | |
1789 | * required zeroing above? If not this error handling is broken, and | |
1790 | * in particular the if (block_end <= from) check is completely bogus. | |
1791 | */ | |
1792 | bh = head; | |
1793 | block_start = 0; | |
1794 | is_retry = FALSE; | |
1795 | do { | |
1796 | block_end = block_start + blocksize; | |
1797 | if (block_end <= from) | |
1798 | continue; | |
1799 | if (block_start >= to) | |
1800 | break; | |
1801 | if (buffer_new(bh)) { | |
1802 | void *kaddr; | |
1803 | ||
1804 | clear_buffer_new(bh); | |
1805 | kaddr = kmap_atomic(page, KM_USER0); | |
1806 | memset(kaddr + block_start, 0, bh->b_size); | |
1807 | kunmap_atomic(kaddr, KM_USER0); | |
1808 | set_buffer_uptodate(bh); | |
1809 | mark_buffer_dirty(bh); | |
1810 | is_retry = TRUE; | |
1811 | } | |
1812 | } while (block_start = block_end, (bh = bh->b_this_page) != head); | |
1813 | if (is_retry) | |
1814 | flush_dcache_page(page); | |
1815 | if (rl) | |
1816 | up_read(&ni->runlist.lock); | |
1817 | return err; | |
1818 | } | |
1819 | ||
1820 | /** | |
1821 | * ntfs_prepare_write - prepare a page for receiving data | |
1822 | * | |
1823 | * This is called from generic_file_write() with i_sem held on the inode | |
1824 | * (@page->mapping->host). The @page is locked but not kmap()ped. The source | |
1825 | * data has not yet been copied into the @page. | |
1826 | * | |
1827 | * Need to extend the attribute/fill in holes if necessary, create blocks and | |
1828 | * make partially overwritten blocks uptodate, | |
1829 | * | |
1830 | * i_size is not to be modified yet. | |
1831 | * | |
1832 | * Return 0 on success or -errno on error. | |
1833 | * | |
1834 | * Should be using block_prepare_write() [support for sparse files] or | |
1835 | * cont_prepare_write() [no support for sparse files]. Cannot do that due to | |
1836 | * ntfs specifics but can look at them for implementation guidance. | |
1837 | * | |
1838 | * Note: In the range, @from is inclusive and @to is exclusive, i.e. @from is | |
1839 | * the first byte in the page that will be written to and @to is the first byte | |
1840 | * after the last byte that will be written to. | |
1841 | */ | |
1842 | static int ntfs_prepare_write(struct file *file, struct page *page, | |
1843 | unsigned from, unsigned to) | |
1844 | { | |
1845 | s64 new_size; | |
f40661be | 1846 | loff_t i_size; |
1da177e4 LT |
1847 | struct inode *vi = page->mapping->host; |
1848 | ntfs_inode *base_ni = NULL, *ni = NTFS_I(vi); | |
1849 | ntfs_volume *vol = ni->vol; | |
1850 | ntfs_attr_search_ctx *ctx = NULL; | |
1851 | MFT_RECORD *m = NULL; | |
1852 | ATTR_RECORD *a; | |
1853 | u8 *kaddr; | |
1854 | u32 attr_len; | |
1855 | int err; | |
1856 | ||
1857 | ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index " | |
1858 | "0x%lx, from = %u, to = %u.", vi->i_ino, ni->type, | |
1859 | page->index, from, to); | |
1860 | BUG_ON(!PageLocked(page)); | |
1861 | BUG_ON(from > PAGE_CACHE_SIZE); | |
1862 | BUG_ON(to > PAGE_CACHE_SIZE); | |
1863 | BUG_ON(from > to); | |
1864 | BUG_ON(NInoMstProtected(ni)); | |
1865 | /* | |
1866 | * If a previous ntfs_truncate() failed, repeat it and abort if it | |
1867 | * fails again. | |
1868 | */ | |
1869 | if (unlikely(NInoTruncateFailed(ni))) { | |
1870 | down_write(&vi->i_alloc_sem); | |
1871 | err = ntfs_truncate(vi); | |
1872 | up_write(&vi->i_alloc_sem); | |
1873 | if (err || NInoTruncateFailed(ni)) { | |
1874 | if (!err) | |
1875 | err = -EIO; | |
1876 | goto err_out; | |
1877 | } | |
1878 | } | |
1879 | /* If the attribute is not resident, deal with it elsewhere. */ | |
1880 | if (NInoNonResident(ni)) { | |
1881 | /* | |
1882 | * Only unnamed $DATA attributes can be compressed, encrypted, | |
1883 | * and/or sparse. | |
1884 | */ | |
1885 | if (ni->type == AT_DATA && !ni->name_len) { | |
1886 | /* If file is encrypted, deny access, just like NT4. */ | |
1887 | if (NInoEncrypted(ni)) { | |
1888 | ntfs_debug("Denying write access to encrypted " | |
1889 | "file."); | |
1890 | return -EACCES; | |
1891 | } | |
1892 | /* Compressed data streams are handled in compress.c. */ | |
1893 | if (NInoCompressed(ni)) { | |
1894 | // TODO: Implement and replace this check with | |
1895 | // return ntfs_write_compressed_block(page); | |
1896 | ntfs_error(vi->i_sb, "Writing to compressed " | |
1897 | "files is not supported yet. " | |
1898 | "Sorry."); | |
1899 | return -EOPNOTSUPP; | |
1900 | } | |
1901 | // TODO: Implement and remove this check. | |
1902 | if (NInoSparse(ni)) { | |
1903 | ntfs_error(vi->i_sb, "Writing to sparse files " | |
1904 | "is not supported yet. Sorry."); | |
1905 | return -EOPNOTSUPP; | |
1906 | } | |
1907 | } | |
1908 | /* Normal data stream. */ | |
1909 | return ntfs_prepare_nonresident_write(page, from, to); | |
1910 | } | |
1911 | /* | |
1912 | * Attribute is resident, implying it is not compressed, encrypted, or | |
1913 | * sparse. | |
1914 | */ | |
1915 | BUG_ON(page_has_buffers(page)); | |
1916 | new_size = ((s64)page->index << PAGE_CACHE_SHIFT) + to; | |
1917 | /* If we do not need to resize the attribute allocation we are done. */ | |
07a4e2da | 1918 | if (new_size <= i_size_read(vi)) |
1da177e4 | 1919 | goto done; |
1da177e4 LT |
1920 | /* Map, pin, and lock the (base) mft record. */ |
1921 | if (!NInoAttr(ni)) | |
1922 | base_ni = ni; | |
1923 | else | |
1924 | base_ni = ni->ext.base_ntfs_ino; | |
1925 | m = map_mft_record(base_ni); | |
1926 | if (IS_ERR(m)) { | |
1927 | err = PTR_ERR(m); | |
1928 | m = NULL; | |
1929 | ctx = NULL; | |
1930 | goto err_out; | |
1931 | } | |
1932 | ctx = ntfs_attr_get_search_ctx(base_ni, m); | |
1933 | if (unlikely(!ctx)) { | |
1934 | err = -ENOMEM; | |
1935 | goto err_out; | |
1936 | } | |
1937 | err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, | |
1938 | CASE_SENSITIVE, 0, NULL, 0, ctx); | |
1939 | if (unlikely(err)) { | |
1940 | if (err == -ENOENT) | |
1941 | err = -EIO; | |
1942 | goto err_out; | |
1943 | } | |
1944 | m = ctx->mrec; | |
1945 | a = ctx->attr; | |
1946 | /* The total length of the attribute value. */ | |
1947 | attr_len = le32_to_cpu(a->data.resident.value_length); | |
946929d8 | 1948 | /* Fix an eventual previous failure of ntfs_commit_write(). */ |
f40661be AA |
1949 | i_size = i_size_read(vi); |
1950 | if (unlikely(attr_len > i_size)) { | |
1951 | attr_len = i_size; | |
946929d8 | 1952 | a->data.resident.value_length = cpu_to_le32(attr_len); |
946929d8 | 1953 | } |
946929d8 AA |
1954 | /* If we do not need to resize the attribute allocation we are done. */ |
1955 | if (new_size <= attr_len) | |
1956 | goto done_unm; | |
1da177e4 LT |
1957 | /* Check if new size is allowed in $AttrDef. */ |
1958 | err = ntfs_attr_size_bounds_check(vol, ni->type, new_size); | |
1959 | if (unlikely(err)) { | |
1960 | if (err == -ERANGE) { | |
1961 | ntfs_error(vol->sb, "Write would cause the inode " | |
1962 | "0x%lx to exceed the maximum size for " | |
1963 | "its attribute type (0x%x). Aborting " | |
1964 | "write.", vi->i_ino, | |
1965 | le32_to_cpu(ni->type)); | |
1966 | } else { | |
1967 | ntfs_error(vol->sb, "Inode 0x%lx has unknown " | |
1968 | "attribute type 0x%x. Aborting " | |
1969 | "write.", vi->i_ino, | |
1970 | le32_to_cpu(ni->type)); | |
1971 | err = -EIO; | |
1972 | } | |
1973 | goto err_out2; | |
1974 | } | |
1975 | /* | |
1976 | * Extend the attribute record to be able to store the new attribute | |
1977 | * size. | |
1978 | */ | |
1979 | if (new_size >= vol->mft_record_size || ntfs_attr_record_resize(m, a, | |
1980 | le16_to_cpu(a->data.resident.value_offset) + | |
1981 | new_size)) { | |
1982 | /* Not enough space in the mft record. */ | |
1983 | ntfs_error(vol->sb, "Not enough space in the mft record for " | |
1984 | "the resized attribute value. This is not " | |
1985 | "supported yet. Aborting write."); | |
1986 | err = -EOPNOTSUPP; | |
1987 | goto err_out2; | |
1988 | } | |
1989 | /* | |
1990 | * We have enough space in the mft record to fit the write. This | |
1991 | * implies the attribute is smaller than the mft record and hence the | |
1992 | * attribute must be in a single page and hence page->index must be 0. | |
1993 | */ | |
1994 | BUG_ON(page->index); | |
1995 | /* | |
1996 | * If the beginning of the write is past the old size, enlarge the | |
1997 | * attribute value up to the beginning of the write and fill it with | |
1998 | * zeroes. | |
1999 | */ | |
2000 | if (from > attr_len) { | |
2001 | memset((u8*)a + le16_to_cpu(a->data.resident.value_offset) + | |
2002 | attr_len, 0, from - attr_len); | |
2003 | a->data.resident.value_length = cpu_to_le32(from); | |
2004 | /* Zero the corresponding area in the page as well. */ | |
2005 | if (PageUptodate(page)) { | |
2006 | kaddr = kmap_atomic(page, KM_USER0); | |
2007 | memset(kaddr + attr_len, 0, from - attr_len); | |
2008 | kunmap_atomic(kaddr, KM_USER0); | |
2009 | flush_dcache_page(page); | |
2010 | } | |
2011 | } | |
2012 | flush_dcache_mft_record_page(ctx->ntfs_ino); | |
2013 | mark_mft_record_dirty(ctx->ntfs_ino); | |
946929d8 | 2014 | done_unm: |
1da177e4 LT |
2015 | ntfs_attr_put_search_ctx(ctx); |
2016 | unmap_mft_record(base_ni); | |
2017 | /* | |
2018 | * Because resident attributes are handled by memcpy() to/from the | |
2019 | * corresponding MFT record, and because this form of i/o is byte | |
2020 | * aligned rather than block aligned, there is no need to bring the | |
2021 | * page uptodate here as in the non-resident case where we need to | |
2022 | * bring the buffers straddled by the write uptodate before | |
2023 | * generic_file_write() does the copying from userspace. | |
2024 | * | |
2025 | * We thus defer the uptodate bringing of the page region outside the | |
2026 | * region written to to ntfs_commit_write(), which makes the code | |
2027 | * simpler and saves one atomic kmap which is good. | |
2028 | */ | |
2029 | done: | |
2030 | ntfs_debug("Done."); | |
2031 | return 0; | |
2032 | err_out: | |
2033 | if (err == -ENOMEM) | |
2034 | ntfs_warning(vi->i_sb, "Error allocating memory required to " | |
2035 | "prepare the write."); | |
2036 | else { | |
2037 | ntfs_error(vi->i_sb, "Resident attribute prepare write failed " | |
2038 | "with error %i.", err); | |
2039 | NVolSetErrors(vol); | |
2040 | make_bad_inode(vi); | |
2041 | } | |
2042 | err_out2: | |
2043 | if (ctx) | |
2044 | ntfs_attr_put_search_ctx(ctx); | |
2045 | if (m) | |
2046 | unmap_mft_record(base_ni); | |
2047 | return err; | |
2048 | } | |
2049 | ||
2050 | /** | |
2051 | * ntfs_commit_nonresident_write - | |
2052 | * | |
2053 | */ | |
2054 | static int ntfs_commit_nonresident_write(struct page *page, | |
2055 | unsigned from, unsigned to) | |
2056 | { | |
2057 | s64 pos = ((s64)page->index << PAGE_CACHE_SHIFT) + to; | |
2058 | struct inode *vi = page->mapping->host; | |
2059 | struct buffer_head *bh, *head; | |
2060 | unsigned int block_start, block_end, blocksize; | |
2061 | BOOL partial; | |
2062 | ||
2063 | ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index " | |
2064 | "0x%lx, from = %u, to = %u.", vi->i_ino, | |
2065 | NTFS_I(vi)->type, page->index, from, to); | |
2066 | blocksize = 1 << vi->i_blkbits; | |
2067 | ||
2068 | // FIXME: We need a whole slew of special cases in here for compressed | |
2069 | // files for example... | |
2070 | // For now, we know ntfs_prepare_write() would have failed so we can't | |
2071 | // get here in any of the cases which we have to special case, so we | |
2072 | // are just a ripped off, unrolled generic_commit_write(). | |
2073 | ||
2074 | bh = head = page_buffers(page); | |
2075 | block_start = 0; | |
2076 | partial = FALSE; | |
2077 | do { | |
2078 | block_end = block_start + blocksize; | |
2079 | if (block_end <= from || block_start >= to) { | |
2080 | if (!buffer_uptodate(bh)) | |
2081 | partial = TRUE; | |
2082 | } else { | |
2083 | set_buffer_uptodate(bh); | |
2084 | mark_buffer_dirty(bh); | |
2085 | } | |
2086 | } while (block_start = block_end, (bh = bh->b_this_page) != head); | |
2087 | /* | |
2088 | * If this is a partial write which happened to make all buffers | |
2089 | * uptodate then we can optimize away a bogus ->readpage() for the next | |
2090 | * read(). Here we 'discover' whether the page went uptodate as a | |
2091 | * result of this (potentially partial) write. | |
2092 | */ | |
2093 | if (!partial) | |
2094 | SetPageUptodate(page); | |
2095 | /* | |
2096 | * Not convinced about this at all. See disparity comment above. For | |
2097 | * now we know ntfs_prepare_write() would have failed in the write | |
2098 | * exceeds i_size case, so this will never trigger which is fine. | |
2099 | */ | |
07a4e2da | 2100 | if (pos > i_size_read(vi)) { |
1da177e4 LT |
2101 | ntfs_error(vi->i_sb, "Writing beyond the existing file size is " |
2102 | "not supported yet. Sorry."); | |
2103 | return -EOPNOTSUPP; | |
2104 | // vi->i_size = pos; | |
2105 | // mark_inode_dirty(vi); | |
2106 | } | |
2107 | ntfs_debug("Done."); | |
2108 | return 0; | |
2109 | } | |
2110 | ||
2111 | /** | |
2112 | * ntfs_commit_write - commit the received data | |
2113 | * | |
2114 | * This is called from generic_file_write() with i_sem held on the inode | |
2115 | * (@page->mapping->host). The @page is locked but not kmap()ped. The source | |
2116 | * data has already been copied into the @page. ntfs_prepare_write() has been | |
2117 | * called before the data copied and it returned success so we can take the | |
2118 | * results of various BUG checks and some error handling for granted. | |
2119 | * | |
2120 | * Need to mark modified blocks dirty so they get written out later when | |
2121 | * ntfs_writepage() is invoked by the VM. | |
2122 | * | |
2123 | * Return 0 on success or -errno on error. | |
2124 | * | |
2125 | * Should be using generic_commit_write(). This marks buffers uptodate and | |
2126 | * dirty, sets the page uptodate if all buffers in the page are uptodate, and | |
2127 | * updates i_size if the end of io is beyond i_size. In that case, it also | |
2128 | * marks the inode dirty. | |
2129 | * | |
2130 | * Cannot use generic_commit_write() due to ntfs specialities but can look at | |
2131 | * it for implementation guidance. | |
2132 | * | |
2133 | * If things have gone as outlined in ntfs_prepare_write(), then we do not | |
2134 | * need to do any page content modifications here at all, except in the write | |
2135 | * to resident attribute case, where we need to do the uptodate bringing here | |
2136 | * which we combine with the copying into the mft record which means we save | |
2137 | * one atomic kmap. | |
2138 | */ | |
2139 | static int ntfs_commit_write(struct file *file, struct page *page, | |
2140 | unsigned from, unsigned to) | |
2141 | { | |
2142 | struct inode *vi = page->mapping->host; | |
2143 | ntfs_inode *base_ni, *ni = NTFS_I(vi); | |
2144 | char *kaddr, *kattr; | |
2145 | ntfs_attr_search_ctx *ctx; | |
2146 | MFT_RECORD *m; | |
2147 | ATTR_RECORD *a; | |
2148 | u32 attr_len; | |
2149 | int err; | |
2150 | ||
2151 | ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index " | |
2152 | "0x%lx, from = %u, to = %u.", vi->i_ino, ni->type, | |
2153 | page->index, from, to); | |
2154 | /* If the attribute is not resident, deal with it elsewhere. */ | |
2155 | if (NInoNonResident(ni)) { | |
2156 | /* Only unnamed $DATA attributes can be compressed/encrypted. */ | |
2157 | if (ni->type == AT_DATA && !ni->name_len) { | |
2158 | /* Encrypted files need separate handling. */ | |
2159 | if (NInoEncrypted(ni)) { | |
2160 | // We never get here at present! | |
2161 | BUG(); | |
2162 | } | |
2163 | /* Compressed data streams are handled in compress.c. */ | |
2164 | if (NInoCompressed(ni)) { | |
2165 | // TODO: Implement this! | |
2166 | // return ntfs_write_compressed_block(page); | |
2167 | // We never get here at present! | |
2168 | BUG(); | |
2169 | } | |
2170 | } | |
2171 | /* Normal data stream. */ | |
2172 | return ntfs_commit_nonresident_write(page, from, to); | |
2173 | } | |
2174 | /* | |
2175 | * Attribute is resident, implying it is not compressed, encrypted, or | |
2176 | * sparse. | |
2177 | */ | |
2178 | if (!NInoAttr(ni)) | |
2179 | base_ni = ni; | |
2180 | else | |
2181 | base_ni = ni->ext.base_ntfs_ino; | |
2182 | /* Map, pin, and lock the mft record. */ | |
2183 | m = map_mft_record(base_ni); | |
2184 | if (IS_ERR(m)) { | |
2185 | err = PTR_ERR(m); | |
2186 | m = NULL; | |
2187 | ctx = NULL; | |
2188 | goto err_out; | |
2189 | } | |
2190 | ctx = ntfs_attr_get_search_ctx(base_ni, m); | |
2191 | if (unlikely(!ctx)) { | |
2192 | err = -ENOMEM; | |
2193 | goto err_out; | |
2194 | } | |
2195 | err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, | |
2196 | CASE_SENSITIVE, 0, NULL, 0, ctx); | |
2197 | if (unlikely(err)) { | |
2198 | if (err == -ENOENT) | |
2199 | err = -EIO; | |
2200 | goto err_out; | |
2201 | } | |
2202 | a = ctx->attr; | |
2203 | /* The total length of the attribute value. */ | |
2204 | attr_len = le32_to_cpu(a->data.resident.value_length); | |
2205 | BUG_ON(from > attr_len); | |
2206 | kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset); | |
2207 | kaddr = kmap_atomic(page, KM_USER0); | |
2208 | /* Copy the received data from the page to the mft record. */ | |
2209 | memcpy(kattr + from, kaddr + from, to - from); | |
2210 | /* Update the attribute length if necessary. */ | |
2211 | if (to > attr_len) { | |
2212 | attr_len = to; | |
2213 | a->data.resident.value_length = cpu_to_le32(attr_len); | |
2214 | } | |
2215 | /* | |
2216 | * If the page is not uptodate, bring the out of bounds area(s) | |
2217 | * uptodate by copying data from the mft record to the page. | |
2218 | */ | |
2219 | if (!PageUptodate(page)) { | |
2220 | if (from > 0) | |
2221 | memcpy(kaddr, kattr, from); | |
2222 | if (to < attr_len) | |
2223 | memcpy(kaddr + to, kattr + to, attr_len - to); | |
2224 | /* Zero the region outside the end of the attribute value. */ | |
2225 | if (attr_len < PAGE_CACHE_SIZE) | |
2226 | memset(kaddr + attr_len, 0, PAGE_CACHE_SIZE - attr_len); | |
2227 | /* | |
2228 | * The probability of not having done any of the above is | |
2229 | * extremely small, so we just flush unconditionally. | |
2230 | */ | |
2231 | flush_dcache_page(page); | |
2232 | SetPageUptodate(page); | |
2233 | } | |
2234 | kunmap_atomic(kaddr, KM_USER0); | |
2235 | /* Update i_size if necessary. */ | |
07a4e2da AA |
2236 | if (i_size_read(vi) < attr_len) { |
2237 | unsigned long flags; | |
2238 | ||
2239 | write_lock_irqsave(&ni->size_lock, flags); | |
1da177e4 LT |
2240 | ni->allocated_size = ni->initialized_size = attr_len; |
2241 | i_size_write(vi, attr_len); | |
07a4e2da | 2242 | write_unlock_irqrestore(&ni->size_lock, flags); |
1da177e4 LT |
2243 | } |
2244 | /* Mark the mft record dirty, so it gets written back. */ | |
2245 | flush_dcache_mft_record_page(ctx->ntfs_ino); | |
2246 | mark_mft_record_dirty(ctx->ntfs_ino); | |
2247 | ntfs_attr_put_search_ctx(ctx); | |
2248 | unmap_mft_record(base_ni); | |
2249 | ntfs_debug("Done."); | |
2250 | return 0; | |
2251 | err_out: | |
2252 | if (err == -ENOMEM) { | |
2253 | ntfs_warning(vi->i_sb, "Error allocating memory required to " | |
2254 | "commit the write."); | |
2255 | if (PageUptodate(page)) { | |
2256 | ntfs_warning(vi->i_sb, "Page is uptodate, setting " | |
2257 | "dirty so the write will be retried " | |
2258 | "later on by the VM."); | |
2259 | /* | |
2260 | * Put the page on mapping->dirty_pages, but leave its | |
2261 | * buffers' dirty state as-is. | |
2262 | */ | |
2263 | __set_page_dirty_nobuffers(page); | |
2264 | err = 0; | |
2265 | } else | |
2266 | ntfs_error(vi->i_sb, "Page is not uptodate. Written " | |
2267 | "data has been lost."); | |
2268 | } else { | |
2269 | ntfs_error(vi->i_sb, "Resident attribute commit write failed " | |
2270 | "with error %i.", err); | |
2271 | NVolSetErrors(ni->vol); | |
2272 | make_bad_inode(vi); | |
2273 | } | |
2274 | if (ctx) | |
2275 | ntfs_attr_put_search_ctx(ctx); | |
2276 | if (m) | |
2277 | unmap_mft_record(base_ni); | |
2278 | return err; | |
2279 | } | |
2280 | ||
2281 | #endif /* NTFS_RW */ | |
2282 | ||
2283 | /** | |
2284 | * ntfs_aops - general address space operations for inodes and attributes | |
2285 | */ | |
2286 | struct address_space_operations ntfs_aops = { | |
2287 | .readpage = ntfs_readpage, /* Fill page with data. */ | |
2288 | .sync_page = block_sync_page, /* Currently, just unplugs the | |
2289 | disk request queue. */ | |
2290 | #ifdef NTFS_RW | |
2291 | .writepage = ntfs_writepage, /* Write dirty page to disk. */ | |
2292 | .prepare_write = ntfs_prepare_write, /* Prepare page and buffers | |
2293 | ready to receive data. */ | |
2294 | .commit_write = ntfs_commit_write, /* Commit received data. */ | |
2295 | #endif /* NTFS_RW */ | |
2296 | }; | |
2297 | ||
2298 | /** | |
2299 | * ntfs_mst_aops - general address space operations for mst protecteed inodes | |
2300 | * and attributes | |
2301 | */ | |
2302 | struct address_space_operations ntfs_mst_aops = { | |
2303 | .readpage = ntfs_readpage, /* Fill page with data. */ | |
2304 | .sync_page = block_sync_page, /* Currently, just unplugs the | |
2305 | disk request queue. */ | |
2306 | #ifdef NTFS_RW | |
2307 | .writepage = ntfs_writepage, /* Write dirty page to disk. */ | |
2308 | .set_page_dirty = __set_page_dirty_nobuffers, /* Set the page dirty | |
2309 | without touching the buffers | |
2310 | belonging to the page. */ | |
2311 | #endif /* NTFS_RW */ | |
2312 | }; | |
2313 | ||
2314 | #ifdef NTFS_RW | |
2315 | ||
2316 | /** | |
2317 | * mark_ntfs_record_dirty - mark an ntfs record dirty | |
2318 | * @page: page containing the ntfs record to mark dirty | |
2319 | * @ofs: byte offset within @page at which the ntfs record begins | |
2320 | * | |
2321 | * Set the buffers and the page in which the ntfs record is located dirty. | |
2322 | * | |
2323 | * The latter also marks the vfs inode the ntfs record belongs to dirty | |
2324 | * (I_DIRTY_PAGES only). | |
2325 | * | |
2326 | * If the page does not have buffers, we create them and set them uptodate. | |
2327 | * The page may not be locked which is why we need to handle the buffers under | |
2328 | * the mapping->private_lock. Once the buffers are marked dirty we no longer | |
2329 | * need the lock since try_to_free_buffers() does not free dirty buffers. | |
2330 | */ | |
2331 | void mark_ntfs_record_dirty(struct page *page, const unsigned int ofs) { | |
2332 | struct address_space *mapping = page->mapping; | |
2333 | ntfs_inode *ni = NTFS_I(mapping->host); | |
2334 | struct buffer_head *bh, *head, *buffers_to_free = NULL; | |
2335 | unsigned int end, bh_size, bh_ofs; | |
2336 | ||
2337 | BUG_ON(!PageUptodate(page)); | |
2338 | end = ofs + ni->itype.index.block_size; | |
2339 | bh_size = 1 << VFS_I(ni)->i_blkbits; | |
2340 | spin_lock(&mapping->private_lock); | |
2341 | if (unlikely(!page_has_buffers(page))) { | |
2342 | spin_unlock(&mapping->private_lock); | |
2343 | bh = head = alloc_page_buffers(page, bh_size, 1); | |
2344 | spin_lock(&mapping->private_lock); | |
2345 | if (likely(!page_has_buffers(page))) { | |
2346 | struct buffer_head *tail; | |
2347 | ||
2348 | do { | |
2349 | set_buffer_uptodate(bh); | |
2350 | tail = bh; | |
2351 | bh = bh->b_this_page; | |
2352 | } while (bh); | |
2353 | tail->b_this_page = head; | |
2354 | attach_page_buffers(page, head); | |
2355 | } else | |
2356 | buffers_to_free = bh; | |
2357 | } | |
2358 | bh = head = page_buffers(page); | |
2359 | do { | |
2360 | bh_ofs = bh_offset(bh); | |
2361 | if (bh_ofs + bh_size <= ofs) | |
2362 | continue; | |
2363 | if (unlikely(bh_ofs >= end)) | |
2364 | break; | |
2365 | set_buffer_dirty(bh); | |
2366 | } while ((bh = bh->b_this_page) != head); | |
2367 | spin_unlock(&mapping->private_lock); | |
2368 | __set_page_dirty_nobuffers(page); | |
2369 | if (unlikely(buffers_to_free)) { | |
2370 | do { | |
2371 | bh = buffers_to_free->b_this_page; | |
2372 | free_buffer_head(buffers_to_free); | |
2373 | buffers_to_free = bh; | |
2374 | } while (buffers_to_free); | |
2375 | } | |
2376 | } | |
2377 | ||
2378 | #endif /* NTFS_RW */ |