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1/*
2 * file.c - NTFS kernel file operations. Part of the Linux-NTFS project.
3 *
4 * Copyright (c) 2001-2011 Anton Altaparmakov and Tuxera Inc.
5 *
6 * This program/include file is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as published
8 * by the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program/include file is distributed in the hope that it will be
12 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
13 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program (in the main directory of the Linux-NTFS
18 * distribution in the file COPYING); if not, write to the Free Software
19 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22#include <linux/buffer_head.h>
23#include <linux/gfp.h>
24#include <linux/pagemap.h>
25#include <linux/pagevec.h>
26#include <linux/sched.h>
27#include <linux/swap.h>
28#include <linux/uio.h>
29#include <linux/writeback.h>
30
31#include <asm/page.h>
32#include <asm/uaccess.h>
33
34#include "attrib.h"
35#include "bitmap.h"
36#include "inode.h"
37#include "debug.h"
38#include "lcnalloc.h"
39#include "malloc.h"
40#include "mft.h"
41#include "ntfs.h"
42
43/**
44 * ntfs_file_open - called when an inode is about to be opened
45 * @vi: inode to be opened
46 * @filp: file structure describing the inode
47 *
48 * Limit file size to the page cache limit on architectures where unsigned long
49 * is 32-bits. This is the most we can do for now without overflowing the page
50 * cache page index. Doing it this way means we don't run into problems because
51 * of existing too large files. It would be better to allow the user to read
52 * the beginning of the file but I doubt very much anyone is going to hit this
53 * check on a 32-bit architecture, so there is no point in adding the extra
54 * complexity required to support this.
55 *
56 * On 64-bit architectures, the check is hopefully optimized away by the
57 * compiler.
58 *
59 * After the check passes, just call generic_file_open() to do its work.
60 */
61static int ntfs_file_open(struct inode *vi, struct file *filp)
62{
63 if (sizeof(unsigned long) < 8) {
64 if (i_size_read(vi) > MAX_LFS_FILESIZE)
65 return -EOVERFLOW;
66 }
67 return generic_file_open(vi, filp);
68}
69
70#ifdef NTFS_RW
71
72/**
73 * ntfs_attr_extend_initialized - extend the initialized size of an attribute
74 * @ni: ntfs inode of the attribute to extend
75 * @new_init_size: requested new initialized size in bytes
76 * @cached_page: store any allocated but unused page here
77 * @lru_pvec: lru-buffering pagevec of the caller
78 *
79 * Extend the initialized size of an attribute described by the ntfs inode @ni
80 * to @new_init_size bytes. This involves zeroing any non-sparse space between
81 * the old initialized size and @new_init_size both in the page cache and on
82 * disk (if relevant complete pages are already uptodate in the page cache then
83 * these are simply marked dirty).
84 *
85 * As a side-effect, the file size (vfs inode->i_size) may be incremented as,
86 * in the resident attribute case, it is tied to the initialized size and, in
87 * the non-resident attribute case, it may not fall below the initialized size.
88 *
89 * Note that if the attribute is resident, we do not need to touch the page
90 * cache at all. This is because if the page cache page is not uptodate we
91 * bring it uptodate later, when doing the write to the mft record since we
92 * then already have the page mapped. And if the page is uptodate, the
93 * non-initialized region will already have been zeroed when the page was
94 * brought uptodate and the region may in fact already have been overwritten
95 * with new data via mmap() based writes, so we cannot just zero it. And since
96 * POSIX specifies that the behaviour of resizing a file whilst it is mmap()ped
97 * is unspecified, we choose not to do zeroing and thus we do not need to touch
98 * the page at all. For a more detailed explanation see ntfs_truncate() in
99 * fs/ntfs/inode.c.
100 *
101 * Return 0 on success and -errno on error. In the case that an error is
102 * encountered it is possible that the initialized size will already have been
103 * incremented some way towards @new_init_size but it is guaranteed that if
104 * this is the case, the necessary zeroing will also have happened and that all
105 * metadata is self-consistent.
106 *
107 * Locking: i_mutex on the vfs inode corrseponsind to the ntfs inode @ni must be
108 * held by the caller.
109 */
110static int ntfs_attr_extend_initialized(ntfs_inode *ni, const s64 new_init_size)
111{
112 s64 old_init_size;
113 loff_t old_i_size;
114 pgoff_t index, end_index;
115 unsigned long flags;
116 struct inode *vi = VFS_I(ni);
117 ntfs_inode *base_ni;
118 MFT_RECORD *m = NULL;
119 ATTR_RECORD *a;
120 ntfs_attr_search_ctx *ctx = NULL;
121 struct address_space *mapping;
122 struct page *page = NULL;
123 u8 *kattr;
124 int err;
125 u32 attr_len;
126
127 read_lock_irqsave(&ni->size_lock, flags);
128 old_init_size = ni->initialized_size;
129 old_i_size = i_size_read(vi);
130 BUG_ON(new_init_size > ni->allocated_size);
131 read_unlock_irqrestore(&ni->size_lock, flags);
132 ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, "
133 "old_initialized_size 0x%llx, "
134 "new_initialized_size 0x%llx, i_size 0x%llx.",
135 vi->i_ino, (unsigned)le32_to_cpu(ni->type),
136 (unsigned long long)old_init_size,
137 (unsigned long long)new_init_size, old_i_size);
138 if (!NInoAttr(ni))
139 base_ni = ni;
140 else
141 base_ni = ni->ext.base_ntfs_ino;
142 /* Use goto to reduce indentation and we need the label below anyway. */
143 if (NInoNonResident(ni))
144 goto do_non_resident_extend;
145 BUG_ON(old_init_size != old_i_size);
146 m = map_mft_record(base_ni);
147 if (IS_ERR(m)) {
148 err = PTR_ERR(m);
149 m = NULL;
150 goto err_out;
151 }
152 ctx = ntfs_attr_get_search_ctx(base_ni, m);
153 if (unlikely(!ctx)) {
154 err = -ENOMEM;
155 goto err_out;
156 }
157 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
158 CASE_SENSITIVE, 0, NULL, 0, ctx);
159 if (unlikely(err)) {
160 if (err == -ENOENT)
161 err = -EIO;
162 goto err_out;
163 }
164 m = ctx->mrec;
165 a = ctx->attr;
166 BUG_ON(a->non_resident);
167 /* The total length of the attribute value. */
168 attr_len = le32_to_cpu(a->data.resident.value_length);
169 BUG_ON(old_i_size != (loff_t)attr_len);
170 /*
171 * Do the zeroing in the mft record and update the attribute size in
172 * the mft record.
173 */
174 kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset);
175 memset(kattr + attr_len, 0, new_init_size - attr_len);
176 a->data.resident.value_length = cpu_to_le32((u32)new_init_size);
177 /* Finally, update the sizes in the vfs and ntfs inodes. */
178 write_lock_irqsave(&ni->size_lock, flags);
179 i_size_write(vi, new_init_size);
180 ni->initialized_size = new_init_size;
181 write_unlock_irqrestore(&ni->size_lock, flags);
182 goto done;
183do_non_resident_extend:
184 /*
185 * If the new initialized size @new_init_size exceeds the current file
186 * size (vfs inode->i_size), we need to extend the file size to the
187 * new initialized size.
188 */
189 if (new_init_size > old_i_size) {
190 m = map_mft_record(base_ni);
191 if (IS_ERR(m)) {
192 err = PTR_ERR(m);
193 m = NULL;
194 goto err_out;
195 }
196 ctx = ntfs_attr_get_search_ctx(base_ni, m);
197 if (unlikely(!ctx)) {
198 err = -ENOMEM;
199 goto err_out;
200 }
201 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
202 CASE_SENSITIVE, 0, NULL, 0, ctx);
203 if (unlikely(err)) {
204 if (err == -ENOENT)
205 err = -EIO;
206 goto err_out;
207 }
208 m = ctx->mrec;
209 a = ctx->attr;
210 BUG_ON(!a->non_resident);
211 BUG_ON(old_i_size != (loff_t)
212 sle64_to_cpu(a->data.non_resident.data_size));
213 a->data.non_resident.data_size = cpu_to_sle64(new_init_size);
214 flush_dcache_mft_record_page(ctx->ntfs_ino);
215 mark_mft_record_dirty(ctx->ntfs_ino);
216 /* Update the file size in the vfs inode. */
217 i_size_write(vi, new_init_size);
218 ntfs_attr_put_search_ctx(ctx);
219 ctx = NULL;
220 unmap_mft_record(base_ni);
221 m = NULL;
222 }
223 mapping = vi->i_mapping;
224 index = old_init_size >> PAGE_CACHE_SHIFT;
225 end_index = (new_init_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
226 do {
227 /*
228 * Read the page. If the page is not present, this will zero
229 * the uninitialized regions for us.
230 */
231 page = read_mapping_page(mapping, index, NULL);
232 if (IS_ERR(page)) {
233 err = PTR_ERR(page);
234 goto init_err_out;
235 }
236 if (unlikely(PageError(page))) {
237 page_cache_release(page);
238 err = -EIO;
239 goto init_err_out;
240 }
241 /*
242 * Update the initialized size in the ntfs inode. This is
243 * enough to make ntfs_writepage() work.
244 */
245 write_lock_irqsave(&ni->size_lock, flags);
246 ni->initialized_size = (s64)(index + 1) << PAGE_CACHE_SHIFT;
247 if (ni->initialized_size > new_init_size)
248 ni->initialized_size = new_init_size;
249 write_unlock_irqrestore(&ni->size_lock, flags);
250 /* Set the page dirty so it gets written out. */
251 set_page_dirty(page);
252 page_cache_release(page);
253 /*
254 * Play nice with the vm and the rest of the system. This is
255 * very much needed as we can potentially be modifying the
256 * initialised size from a very small value to a really huge
257 * value, e.g.
258 * f = open(somefile, O_TRUNC);
259 * truncate(f, 10GiB);
260 * seek(f, 10GiB);
261 * write(f, 1);
262 * And this would mean we would be marking dirty hundreds of
263 * thousands of pages or as in the above example more than
264 * two and a half million pages!
265 *
266 * TODO: For sparse pages could optimize this workload by using
267 * the FsMisc / MiscFs page bit as a "PageIsSparse" bit. This
268 * would be set in readpage for sparse pages and here we would
269 * not need to mark dirty any pages which have this bit set.
270 * The only caveat is that we have to clear the bit everywhere
271 * where we allocate any clusters that lie in the page or that
272 * contain the page.
273 *
274 * TODO: An even greater optimization would be for us to only
275 * call readpage() on pages which are not in sparse regions as
276 * determined from the runlist. This would greatly reduce the
277 * number of pages we read and make dirty in the case of sparse
278 * files.
279 */
280 balance_dirty_pages_ratelimited(mapping);
281 cond_resched();
282 } while (++index < end_index);
283 read_lock_irqsave(&ni->size_lock, flags);
284 BUG_ON(ni->initialized_size != new_init_size);
285 read_unlock_irqrestore(&ni->size_lock, flags);
286 /* Now bring in sync the initialized_size in the mft record. */
287 m = map_mft_record(base_ni);
288 if (IS_ERR(m)) {
289 err = PTR_ERR(m);
290 m = NULL;
291 goto init_err_out;
292 }
293 ctx = ntfs_attr_get_search_ctx(base_ni, m);
294 if (unlikely(!ctx)) {
295 err = -ENOMEM;
296 goto init_err_out;
297 }
298 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
299 CASE_SENSITIVE, 0, NULL, 0, ctx);
300 if (unlikely(err)) {
301 if (err == -ENOENT)
302 err = -EIO;
303 goto init_err_out;
304 }
305 m = ctx->mrec;
306 a = ctx->attr;
307 BUG_ON(!a->non_resident);
308 a->data.non_resident.initialized_size = cpu_to_sle64(new_init_size);
309done:
310 flush_dcache_mft_record_page(ctx->ntfs_ino);
311 mark_mft_record_dirty(ctx->ntfs_ino);
312 if (ctx)
313 ntfs_attr_put_search_ctx(ctx);
314 if (m)
315 unmap_mft_record(base_ni);
316 ntfs_debug("Done, initialized_size 0x%llx, i_size 0x%llx.",
317 (unsigned long long)new_init_size, i_size_read(vi));
318 return 0;
319init_err_out:
320 write_lock_irqsave(&ni->size_lock, flags);
321 ni->initialized_size = old_init_size;
322 write_unlock_irqrestore(&ni->size_lock, flags);
323err_out:
324 if (ctx)
325 ntfs_attr_put_search_ctx(ctx);
326 if (m)
327 unmap_mft_record(base_ni);
328 ntfs_debug("Failed. Returning error code %i.", err);
329 return err;
330}
331
332/**
333 * ntfs_fault_in_pages_readable -
334 *
335 * Fault a number of userspace pages into pagetables.
336 *
337 * Unlike include/linux/pagemap.h::fault_in_pages_readable(), this one copes
338 * with more than two userspace pages as well as handling the single page case
339 * elegantly.
340 *
341 * If you find this difficult to understand, then think of the while loop being
342 * the following code, except that we do without the integer variable ret:
343 *
344 * do {
345 * ret = __get_user(c, uaddr);
346 * uaddr += PAGE_SIZE;
347 * } while (!ret && uaddr < end);
348 *
349 * Note, the final __get_user() may well run out-of-bounds of the user buffer,
350 * but _not_ out-of-bounds of the page the user buffer belongs to, and since
351 * this is only a read and not a write, and since it is still in the same page,
352 * it should not matter and this makes the code much simpler.
353 */
354static inline void ntfs_fault_in_pages_readable(const char __user *uaddr,
355 int bytes)
356{
357 const char __user *end;
358 volatile char c;
359
360 /* Set @end to the first byte outside the last page we care about. */
361 end = (const char __user*)PAGE_ALIGN((unsigned long)uaddr + bytes);
362
363 while (!__get_user(c, uaddr) && (uaddr += PAGE_SIZE, uaddr < end))
364 ;
365}
366
367/**
368 * ntfs_fault_in_pages_readable_iovec -
369 *
370 * Same as ntfs_fault_in_pages_readable() but operates on an array of iovecs.
371 */
372static inline void ntfs_fault_in_pages_readable_iovec(const struct iovec *iov,
373 size_t iov_ofs, int bytes)
374{
375 do {
376 const char __user *buf;
377 unsigned len;
378
379 buf = iov->iov_base + iov_ofs;
380 len = iov->iov_len - iov_ofs;
381 if (len > bytes)
382 len = bytes;
383 ntfs_fault_in_pages_readable(buf, len);
384 bytes -= len;
385 iov++;
386 iov_ofs = 0;
387 } while (bytes);
388}
389
390/**
391 * __ntfs_grab_cache_pages - obtain a number of locked pages
392 * @mapping: address space mapping from which to obtain page cache pages
393 * @index: starting index in @mapping at which to begin obtaining pages
394 * @nr_pages: number of page cache pages to obtain
395 * @pages: array of pages in which to return the obtained page cache pages
396 * @cached_page: allocated but as yet unused page
397 * @lru_pvec: lru-buffering pagevec of caller
398 *
399 * Obtain @nr_pages locked page cache pages from the mapping @mapping and
400 * starting at index @index.
401 *
402 * If a page is newly created, add it to lru list
403 *
404 * Note, the page locks are obtained in ascending page index order.
405 */
406static inline int __ntfs_grab_cache_pages(struct address_space *mapping,
407 pgoff_t index, const unsigned nr_pages, struct page **pages,
408 struct page **cached_page)
409{
410 int err, nr;
411
412 BUG_ON(!nr_pages);
413 err = nr = 0;
414 do {
415 pages[nr] = find_lock_page(mapping, index);
416 if (!pages[nr]) {
417 if (!*cached_page) {
418 *cached_page = page_cache_alloc(mapping);
419 if (unlikely(!*cached_page)) {
420 err = -ENOMEM;
421 goto err_out;
422 }
423 }
424 err = add_to_page_cache_lru(*cached_page, mapping, index,
425 GFP_KERNEL);
426 if (unlikely(err)) {
427 if (err == -EEXIST)
428 continue;
429 goto err_out;
430 }
431 pages[nr] = *cached_page;
432 *cached_page = NULL;
433 }
434 index++;
435 nr++;
436 } while (nr < nr_pages);
437out:
438 return err;
439err_out:
440 while (nr > 0) {
441 unlock_page(pages[--nr]);
442 page_cache_release(pages[nr]);
443 }
444 goto out;
445}
446
447static inline int ntfs_submit_bh_for_read(struct buffer_head *bh)
448{
449 lock_buffer(bh);
450 get_bh(bh);
451 bh->b_end_io = end_buffer_read_sync;
452 return submit_bh(READ, bh);
453}
454
455/**
456 * ntfs_prepare_pages_for_non_resident_write - prepare pages for receiving data
457 * @pages: array of destination pages
458 * @nr_pages: number of pages in @pages
459 * @pos: byte position in file at which the write begins
460 * @bytes: number of bytes to be written
461 *
462 * This is called for non-resident attributes from ntfs_file_buffered_write()
463 * with i_mutex held on the inode (@pages[0]->mapping->host). There are
464 * @nr_pages pages in @pages which are locked but not kmap()ped. The source
465 * data has not yet been copied into the @pages.
466 *
467 * Need to fill any holes with actual clusters, allocate buffers if necessary,
468 * ensure all the buffers are mapped, and bring uptodate any buffers that are
469 * only partially being written to.
470 *
471 * If @nr_pages is greater than one, we are guaranteed that the cluster size is
472 * greater than PAGE_CACHE_SIZE, that all pages in @pages are entirely inside
473 * the same cluster and that they are the entirety of that cluster, and that
474 * the cluster is sparse, i.e. we need to allocate a cluster to fill the hole.
475 *
476 * i_size is not to be modified yet.
477 *
478 * Return 0 on success or -errno on error.
479 */
480static int ntfs_prepare_pages_for_non_resident_write(struct page **pages,
481 unsigned nr_pages, s64 pos, size_t bytes)
482{
483 VCN vcn, highest_vcn = 0, cpos, cend, bh_cpos, bh_cend;
484 LCN lcn;
485 s64 bh_pos, vcn_len, end, initialized_size;
486 sector_t lcn_block;
487 struct page *page;
488 struct inode *vi;
489 ntfs_inode *ni, *base_ni = NULL;
490 ntfs_volume *vol;
491 runlist_element *rl, *rl2;
492 struct buffer_head *bh, *head, *wait[2], **wait_bh = wait;
493 ntfs_attr_search_ctx *ctx = NULL;
494 MFT_RECORD *m = NULL;
495 ATTR_RECORD *a = NULL;
496 unsigned long flags;
497 u32 attr_rec_len = 0;
498 unsigned blocksize, u;
499 int err, mp_size;
500 bool rl_write_locked, was_hole, is_retry;
501 unsigned char blocksize_bits;
502 struct {
503 u8 runlist_merged:1;
504 u8 mft_attr_mapped:1;
505 u8 mp_rebuilt:1;
506 u8 attr_switched:1;
507 } status = { 0, 0, 0, 0 };
508
509 BUG_ON(!nr_pages);
510 BUG_ON(!pages);
511 BUG_ON(!*pages);
512 vi = pages[0]->mapping->host;
513 ni = NTFS_I(vi);
514 vol = ni->vol;
515 ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page "
516 "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.",
517 vi->i_ino, ni->type, pages[0]->index, nr_pages,
518 (long long)pos, bytes);
519 blocksize = vol->sb->s_blocksize;
520 blocksize_bits = vol->sb->s_blocksize_bits;
521 u = 0;
522 do {
523 page = pages[u];
524 BUG_ON(!page);
525 /*
526 * create_empty_buffers() will create uptodate/dirty buffers if
527 * the page is uptodate/dirty.
528 */
529 if (!page_has_buffers(page)) {
530 create_empty_buffers(page, blocksize, 0);
531 if (unlikely(!page_has_buffers(page)))
532 return -ENOMEM;
533 }
534 } while (++u < nr_pages);
535 rl_write_locked = false;
536 rl = NULL;
537 err = 0;
538 vcn = lcn = -1;
539 vcn_len = 0;
540 lcn_block = -1;
541 was_hole = false;
542 cpos = pos >> vol->cluster_size_bits;
543 end = pos + bytes;
544 cend = (end + vol->cluster_size - 1) >> vol->cluster_size_bits;
545 /*
546 * Loop over each page and for each page over each buffer. Use goto to
547 * reduce indentation.
548 */
549 u = 0;
550do_next_page:
551 page = pages[u];
552 bh_pos = (s64)page->index << PAGE_CACHE_SHIFT;
553 bh = head = page_buffers(page);
554 do {
555 VCN cdelta;
556 s64 bh_end;
557 unsigned bh_cofs;
558
559 /* Clear buffer_new on all buffers to reinitialise state. */
560 if (buffer_new(bh))
561 clear_buffer_new(bh);
562 bh_end = bh_pos + blocksize;
563 bh_cpos = bh_pos >> vol->cluster_size_bits;
564 bh_cofs = bh_pos & vol->cluster_size_mask;
565 if (buffer_mapped(bh)) {
566 /*
567 * The buffer is already mapped. If it is uptodate,
568 * ignore it.
569 */
570 if (buffer_uptodate(bh))
571 continue;
572 /*
573 * The buffer is not uptodate. If the page is uptodate
574 * set the buffer uptodate and otherwise ignore it.
575 */
576 if (PageUptodate(page)) {
577 set_buffer_uptodate(bh);
578 continue;
579 }
580 /*
581 * Neither the page nor the buffer are uptodate. If
582 * the buffer is only partially being written to, we
583 * need to read it in before the write, i.e. now.
584 */
585 if ((bh_pos < pos && bh_end > pos) ||
586 (bh_pos < end && bh_end > end)) {
587 /*
588 * If the buffer is fully or partially within
589 * the initialized size, do an actual read.
590 * Otherwise, simply zero the buffer.
591 */
592 read_lock_irqsave(&ni->size_lock, flags);
593 initialized_size = ni->initialized_size;
594 read_unlock_irqrestore(&ni->size_lock, flags);
595 if (bh_pos < initialized_size) {
596 ntfs_submit_bh_for_read(bh);
597 *wait_bh++ = bh;
598 } else {
599 zero_user(page, bh_offset(bh),
600 blocksize);
601 set_buffer_uptodate(bh);
602 }
603 }
604 continue;
605 }
606 /* Unmapped buffer. Need to map it. */
607 bh->b_bdev = vol->sb->s_bdev;
608 /*
609 * If the current buffer is in the same clusters as the map
610 * cache, there is no need to check the runlist again. The
611 * map cache is made up of @vcn, which is the first cached file
612 * cluster, @vcn_len which is the number of cached file
613 * clusters, @lcn is the device cluster corresponding to @vcn,
614 * and @lcn_block is the block number corresponding to @lcn.
615 */
616 cdelta = bh_cpos - vcn;
617 if (likely(!cdelta || (cdelta > 0 && cdelta < vcn_len))) {
618map_buffer_cached:
619 BUG_ON(lcn < 0);
620 bh->b_blocknr = lcn_block +
621 (cdelta << (vol->cluster_size_bits -
622 blocksize_bits)) +
623 (bh_cofs >> blocksize_bits);
624 set_buffer_mapped(bh);
625 /*
626 * If the page is uptodate so is the buffer. If the
627 * buffer is fully outside the write, we ignore it if
628 * it was already allocated and we mark it dirty so it
629 * gets written out if we allocated it. On the other
630 * hand, if we allocated the buffer but we are not
631 * marking it dirty we set buffer_new so we can do
632 * error recovery.
633 */
634 if (PageUptodate(page)) {
635 if (!buffer_uptodate(bh))
636 set_buffer_uptodate(bh);
637 if (unlikely(was_hole)) {
638 /* We allocated the buffer. */
639 unmap_underlying_metadata(bh->b_bdev,
640 bh->b_blocknr);
641 if (bh_end <= pos || bh_pos >= end)
642 mark_buffer_dirty(bh);
643 else
644 set_buffer_new(bh);
645 }
646 continue;
647 }
648 /* Page is _not_ uptodate. */
649 if (likely(!was_hole)) {
650 /*
651 * Buffer was already allocated. If it is not
652 * uptodate and is only partially being written
653 * to, we need to read it in before the write,
654 * i.e. now.
655 */
656 if (!buffer_uptodate(bh) && bh_pos < end &&
657 bh_end > pos &&
658 (bh_pos < pos ||
659 bh_end > end)) {
660 /*
661 * If the buffer is fully or partially
662 * within the initialized size, do an
663 * actual read. Otherwise, simply zero
664 * the buffer.
665 */
666 read_lock_irqsave(&ni->size_lock,
667 flags);
668 initialized_size = ni->initialized_size;
669 read_unlock_irqrestore(&ni->size_lock,
670 flags);
671 if (bh_pos < initialized_size) {
672 ntfs_submit_bh_for_read(bh);
673 *wait_bh++ = bh;
674 } else {
675 zero_user(page, bh_offset(bh),
676 blocksize);
677 set_buffer_uptodate(bh);
678 }
679 }
680 continue;
681 }
682 /* We allocated the buffer. */
683 unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
684 /*
685 * If the buffer is fully outside the write, zero it,
686 * set it uptodate, and mark it dirty so it gets
687 * written out. If it is partially being written to,
688 * zero region surrounding the write but leave it to
689 * commit write to do anything else. Finally, if the
690 * buffer is fully being overwritten, do nothing.
691 */
692 if (bh_end <= pos || bh_pos >= end) {
693 if (!buffer_uptodate(bh)) {
694 zero_user(page, bh_offset(bh),
695 blocksize);
696 set_buffer_uptodate(bh);
697 }
698 mark_buffer_dirty(bh);
699 continue;
700 }
701 set_buffer_new(bh);
702 if (!buffer_uptodate(bh) &&
703 (bh_pos < pos || bh_end > end)) {
704 u8 *kaddr;
705 unsigned pofs;
706
707 kaddr = kmap_atomic(page);
708 if (bh_pos < pos) {
709 pofs = bh_pos & ~PAGE_CACHE_MASK;
710 memset(kaddr + pofs, 0, pos - bh_pos);
711 }
712 if (bh_end > end) {
713 pofs = end & ~PAGE_CACHE_MASK;
714 memset(kaddr + pofs, 0, bh_end - end);
715 }
716 kunmap_atomic(kaddr);
717 flush_dcache_page(page);
718 }
719 continue;
720 }
721 /*
722 * Slow path: this is the first buffer in the cluster. If it
723 * is outside allocated size and is not uptodate, zero it and
724 * set it uptodate.
725 */
726 read_lock_irqsave(&ni->size_lock, flags);
727 initialized_size = ni->allocated_size;
728 read_unlock_irqrestore(&ni->size_lock, flags);
729 if (bh_pos > initialized_size) {
730 if (PageUptodate(page)) {
731 if (!buffer_uptodate(bh))
732 set_buffer_uptodate(bh);
733 } else if (!buffer_uptodate(bh)) {
734 zero_user(page, bh_offset(bh), blocksize);
735 set_buffer_uptodate(bh);
736 }
737 continue;
738 }
739 is_retry = false;
740 if (!rl) {
741 down_read(&ni->runlist.lock);
742retry_remap:
743 rl = ni->runlist.rl;
744 }
745 if (likely(rl != NULL)) {
746 /* Seek to element containing target cluster. */
747 while (rl->length && rl[1].vcn <= bh_cpos)
748 rl++;
749 lcn = ntfs_rl_vcn_to_lcn(rl, bh_cpos);
750 if (likely(lcn >= 0)) {
751 /*
752 * Successful remap, setup the map cache and
753 * use that to deal with the buffer.
754 */
755 was_hole = false;
756 vcn = bh_cpos;
757 vcn_len = rl[1].vcn - vcn;
758 lcn_block = lcn << (vol->cluster_size_bits -
759 blocksize_bits);
760 cdelta = 0;
761 /*
762 * If the number of remaining clusters touched
763 * by the write is smaller or equal to the
764 * number of cached clusters, unlock the
765 * runlist as the map cache will be used from
766 * now on.
767 */
768 if (likely(vcn + vcn_len >= cend)) {
769 if (rl_write_locked) {
770 up_write(&ni->runlist.lock);
771 rl_write_locked = false;
772 } else
773 up_read(&ni->runlist.lock);
774 rl = NULL;
775 }
776 goto map_buffer_cached;
777 }
778 } else
779 lcn = LCN_RL_NOT_MAPPED;
780 /*
781 * If it is not a hole and not out of bounds, the runlist is
782 * probably unmapped so try to map it now.
783 */
784 if (unlikely(lcn != LCN_HOLE && lcn != LCN_ENOENT)) {
785 if (likely(!is_retry && lcn == LCN_RL_NOT_MAPPED)) {
786 /* Attempt to map runlist. */
787 if (!rl_write_locked) {
788 /*
789 * We need the runlist locked for
790 * writing, so if it is locked for
791 * reading relock it now and retry in
792 * case it changed whilst we dropped
793 * the lock.
794 */
795 up_read(&ni->runlist.lock);
796 down_write(&ni->runlist.lock);
797 rl_write_locked = true;
798 goto retry_remap;
799 }
800 err = ntfs_map_runlist_nolock(ni, bh_cpos,
801 NULL);
802 if (likely(!err)) {
803 is_retry = true;
804 goto retry_remap;
805 }
806 /*
807 * If @vcn is out of bounds, pretend @lcn is
808 * LCN_ENOENT. As long as the buffer is out
809 * of bounds this will work fine.
810 */
811 if (err == -ENOENT) {
812 lcn = LCN_ENOENT;
813 err = 0;
814 goto rl_not_mapped_enoent;
815 }
816 } else
817 err = -EIO;
818 /* Failed to map the buffer, even after retrying. */
819 bh->b_blocknr = -1;
820 ntfs_error(vol->sb, "Failed to write to inode 0x%lx, "
821 "attribute type 0x%x, vcn 0x%llx, "
822 "vcn offset 0x%x, because its "
823 "location on disk could not be "
824 "determined%s (error code %i).",
825 ni->mft_no, ni->type,
826 (unsigned long long)bh_cpos,
827 (unsigned)bh_pos &
828 vol->cluster_size_mask,
829 is_retry ? " even after retrying" : "",
830 err);
831 break;
832 }
833rl_not_mapped_enoent:
834 /*
835 * The buffer is in a hole or out of bounds. We need to fill
836 * the hole, unless the buffer is in a cluster which is not
837 * touched by the write, in which case we just leave the buffer
838 * unmapped. This can only happen when the cluster size is
839 * less than the page cache size.
840 */
841 if (unlikely(vol->cluster_size < PAGE_CACHE_SIZE)) {
842 bh_cend = (bh_end + vol->cluster_size - 1) >>
843 vol->cluster_size_bits;
844 if ((bh_cend <= cpos || bh_cpos >= cend)) {
845 bh->b_blocknr = -1;
846 /*
847 * If the buffer is uptodate we skip it. If it
848 * is not but the page is uptodate, we can set
849 * the buffer uptodate. If the page is not
850 * uptodate, we can clear the buffer and set it
851 * uptodate. Whether this is worthwhile is
852 * debatable and this could be removed.
853 */
854 if (PageUptodate(page)) {
855 if (!buffer_uptodate(bh))
856 set_buffer_uptodate(bh);
857 } else if (!buffer_uptodate(bh)) {
858 zero_user(page, bh_offset(bh),
859 blocksize);
860 set_buffer_uptodate(bh);
861 }
862 continue;
863 }
864 }
865 /*
866 * Out of bounds buffer is invalid if it was not really out of
867 * bounds.
868 */
869 BUG_ON(lcn != LCN_HOLE);
870 /*
871 * We need the runlist locked for writing, so if it is locked
872 * for reading relock it now and retry in case it changed
873 * whilst we dropped the lock.
874 */
875 BUG_ON(!rl);
876 if (!rl_write_locked) {
877 up_read(&ni->runlist.lock);
878 down_write(&ni->runlist.lock);
879 rl_write_locked = true;
880 goto retry_remap;
881 }
882 /* Find the previous last allocated cluster. */
883 BUG_ON(rl->lcn != LCN_HOLE);
884 lcn = -1;
885 rl2 = rl;
886 while (--rl2 >= ni->runlist.rl) {
887 if (rl2->lcn >= 0) {
888 lcn = rl2->lcn + rl2->length;
889 break;
890 }
891 }
892 rl2 = ntfs_cluster_alloc(vol, bh_cpos, 1, lcn, DATA_ZONE,
893 false);
894 if (IS_ERR(rl2)) {
895 err = PTR_ERR(rl2);
896 ntfs_debug("Failed to allocate cluster, error code %i.",
897 err);
898 break;
899 }
900 lcn = rl2->lcn;
901 rl = ntfs_runlists_merge(ni->runlist.rl, rl2);
902 if (IS_ERR(rl)) {
903 err = PTR_ERR(rl);
904 if (err != -ENOMEM)
905 err = -EIO;
906 if (ntfs_cluster_free_from_rl(vol, rl2)) {
907 ntfs_error(vol->sb, "Failed to release "
908 "allocated cluster in error "
909 "code path. Run chkdsk to "
910 "recover the lost cluster.");
911 NVolSetErrors(vol);
912 }
913 ntfs_free(rl2);
914 break;
915 }
916 ni->runlist.rl = rl;
917 status.runlist_merged = 1;
918 ntfs_debug("Allocated cluster, lcn 0x%llx.",
919 (unsigned long long)lcn);
920 /* Map and lock the mft record and get the attribute record. */
921 if (!NInoAttr(ni))
922 base_ni = ni;
923 else
924 base_ni = ni->ext.base_ntfs_ino;
925 m = map_mft_record(base_ni);
926 if (IS_ERR(m)) {
927 err = PTR_ERR(m);
928 break;
929 }
930 ctx = ntfs_attr_get_search_ctx(base_ni, m);
931 if (unlikely(!ctx)) {
932 err = -ENOMEM;
933 unmap_mft_record(base_ni);
934 break;
935 }
936 status.mft_attr_mapped = 1;
937 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
938 CASE_SENSITIVE, bh_cpos, NULL, 0, ctx);
939 if (unlikely(err)) {
940 if (err == -ENOENT)
941 err = -EIO;
942 break;
943 }
944 m = ctx->mrec;
945 a = ctx->attr;
946 /*
947 * Find the runlist element with which the attribute extent
948 * starts. Note, we cannot use the _attr_ version because we
949 * have mapped the mft record. That is ok because we know the
950 * runlist fragment must be mapped already to have ever gotten
951 * here, so we can just use the _rl_ version.
952 */
953 vcn = sle64_to_cpu(a->data.non_resident.lowest_vcn);
954 rl2 = ntfs_rl_find_vcn_nolock(rl, vcn);
955 BUG_ON(!rl2);
956 BUG_ON(!rl2->length);
957 BUG_ON(rl2->lcn < LCN_HOLE);
958 highest_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn);
959 /*
960 * If @highest_vcn is zero, calculate the real highest_vcn
961 * (which can really be zero).
962 */
963 if (!highest_vcn)
964 highest_vcn = (sle64_to_cpu(
965 a->data.non_resident.allocated_size) >>
966 vol->cluster_size_bits) - 1;
967 /*
968 * Determine the size of the mapping pairs array for the new
969 * extent, i.e. the old extent with the hole filled.
970 */
971 mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, vcn,
972 highest_vcn);
973 if (unlikely(mp_size <= 0)) {
974 if (!(err = mp_size))
975 err = -EIO;
976 ntfs_debug("Failed to get size for mapping pairs "
977 "array, error code %i.", err);
978 break;
979 }
980 /*
981 * Resize the attribute record to fit the new mapping pairs
982 * array.
983 */
984 attr_rec_len = le32_to_cpu(a->length);
985 err = ntfs_attr_record_resize(m, a, mp_size + le16_to_cpu(
986 a->data.non_resident.mapping_pairs_offset));
987 if (unlikely(err)) {
988 BUG_ON(err != -ENOSPC);
989 // TODO: Deal with this by using the current attribute
990 // and fill it with as much of the mapping pairs
991 // array as possible. Then loop over each attribute
992 // extent rewriting the mapping pairs arrays as we go
993 // along and if when we reach the end we have not
994 // enough space, try to resize the last attribute
995 // extent and if even that fails, add a new attribute
996 // extent.
997 // We could also try to resize at each step in the hope
998 // that we will not need to rewrite every single extent.
999 // Note, we may need to decompress some extents to fill
1000 // the runlist as we are walking the extents...
1001 ntfs_error(vol->sb, "Not enough space in the mft "
1002 "record for the extended attribute "
1003 "record. This case is not "
1004 "implemented yet.");
1005 err = -EOPNOTSUPP;
1006 break ;
1007 }
1008 status.mp_rebuilt = 1;
1009 /*
1010 * Generate the mapping pairs array directly into the attribute
1011 * record.
1012 */
1013 err = ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu(
1014 a->data.non_resident.mapping_pairs_offset),
1015 mp_size, rl2, vcn, highest_vcn, NULL);
1016 if (unlikely(err)) {
1017 ntfs_error(vol->sb, "Cannot fill hole in inode 0x%lx, "
1018 "attribute type 0x%x, because building "
1019 "the mapping pairs failed with error "
1020 "code %i.", vi->i_ino,
1021 (unsigned)le32_to_cpu(ni->type), err);
1022 err = -EIO;
1023 break;
1024 }
1025 /* Update the highest_vcn but only if it was not set. */
1026 if (unlikely(!a->data.non_resident.highest_vcn))
1027 a->data.non_resident.highest_vcn =
1028 cpu_to_sle64(highest_vcn);
1029 /*
1030 * If the attribute is sparse/compressed, update the compressed
1031 * size in the ntfs_inode structure and the attribute record.
1032 */
1033 if (likely(NInoSparse(ni) || NInoCompressed(ni))) {
1034 /*
1035 * If we are not in the first attribute extent, switch
1036 * to it, but first ensure the changes will make it to
1037 * disk later.
1038 */
1039 if (a->data.non_resident.lowest_vcn) {
1040 flush_dcache_mft_record_page(ctx->ntfs_ino);
1041 mark_mft_record_dirty(ctx->ntfs_ino);
1042 ntfs_attr_reinit_search_ctx(ctx);
1043 err = ntfs_attr_lookup(ni->type, ni->name,
1044 ni->name_len, CASE_SENSITIVE,
1045 0, NULL, 0, ctx);
1046 if (unlikely(err)) {
1047 status.attr_switched = 1;
1048 break;
1049 }
1050 /* @m is not used any more so do not set it. */
1051 a = ctx->attr;
1052 }
1053 write_lock_irqsave(&ni->size_lock, flags);
1054 ni->itype.compressed.size += vol->cluster_size;
1055 a->data.non_resident.compressed_size =
1056 cpu_to_sle64(ni->itype.compressed.size);
1057 write_unlock_irqrestore(&ni->size_lock, flags);
1058 }
1059 /* Ensure the changes make it to disk. */
1060 flush_dcache_mft_record_page(ctx->ntfs_ino);
1061 mark_mft_record_dirty(ctx->ntfs_ino);
1062 ntfs_attr_put_search_ctx(ctx);
1063 unmap_mft_record(base_ni);
1064 /* Successfully filled the hole. */
1065 status.runlist_merged = 0;
1066 status.mft_attr_mapped = 0;
1067 status.mp_rebuilt = 0;
1068 /* Setup the map cache and use that to deal with the buffer. */
1069 was_hole = true;
1070 vcn = bh_cpos;
1071 vcn_len = 1;
1072 lcn_block = lcn << (vol->cluster_size_bits - blocksize_bits);
1073 cdelta = 0;
1074 /*
1075 * If the number of remaining clusters in the @pages is smaller
1076 * or equal to the number of cached clusters, unlock the
1077 * runlist as the map cache will be used from now on.
1078 */
1079 if (likely(vcn + vcn_len >= cend)) {
1080 up_write(&ni->runlist.lock);
1081 rl_write_locked = false;
1082 rl = NULL;
1083 }
1084 goto map_buffer_cached;
1085 } while (bh_pos += blocksize, (bh = bh->b_this_page) != head);
1086 /* If there are no errors, do the next page. */
1087 if (likely(!err && ++u < nr_pages))
1088 goto do_next_page;
1089 /* If there are no errors, release the runlist lock if we took it. */
1090 if (likely(!err)) {
1091 if (unlikely(rl_write_locked)) {
1092 up_write(&ni->runlist.lock);
1093 rl_write_locked = false;
1094 } else if (unlikely(rl))
1095 up_read(&ni->runlist.lock);
1096 rl = NULL;
1097 }
1098 /* If we issued read requests, let them complete. */
1099 read_lock_irqsave(&ni->size_lock, flags);
1100 initialized_size = ni->initialized_size;
1101 read_unlock_irqrestore(&ni->size_lock, flags);
1102 while (wait_bh > wait) {
1103 bh = *--wait_bh;
1104 wait_on_buffer(bh);
1105 if (likely(buffer_uptodate(bh))) {
1106 page = bh->b_page;
1107 bh_pos = ((s64)page->index << PAGE_CACHE_SHIFT) +
1108 bh_offset(bh);
1109 /*
1110 * If the buffer overflows the initialized size, need
1111 * to zero the overflowing region.
1112 */
1113 if (unlikely(bh_pos + blocksize > initialized_size)) {
1114 int ofs = 0;
1115
1116 if (likely(bh_pos < initialized_size))
1117 ofs = initialized_size - bh_pos;
1118 zero_user_segment(page, bh_offset(bh) + ofs,
1119 blocksize);
1120 }
1121 } else /* if (unlikely(!buffer_uptodate(bh))) */
1122 err = -EIO;
1123 }
1124 if (likely(!err)) {
1125 /* Clear buffer_new on all buffers. */
1126 u = 0;
1127 do {
1128 bh = head = page_buffers(pages[u]);
1129 do {
1130 if (buffer_new(bh))
1131 clear_buffer_new(bh);
1132 } while ((bh = bh->b_this_page) != head);
1133 } while (++u < nr_pages);
1134 ntfs_debug("Done.");
1135 return err;
1136 }
1137 if (status.attr_switched) {
1138 /* Get back to the attribute extent we modified. */
1139 ntfs_attr_reinit_search_ctx(ctx);
1140 if (ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1141 CASE_SENSITIVE, bh_cpos, NULL, 0, ctx)) {
1142 ntfs_error(vol->sb, "Failed to find required "
1143 "attribute extent of attribute in "
1144 "error code path. Run chkdsk to "
1145 "recover.");
1146 write_lock_irqsave(&ni->size_lock, flags);
1147 ni->itype.compressed.size += vol->cluster_size;
1148 write_unlock_irqrestore(&ni->size_lock, flags);
1149 flush_dcache_mft_record_page(ctx->ntfs_ino);
1150 mark_mft_record_dirty(ctx->ntfs_ino);
1151 /*
1152 * The only thing that is now wrong is the compressed
1153 * size of the base attribute extent which chkdsk
1154 * should be able to fix.
1155 */
1156 NVolSetErrors(vol);
1157 } else {
1158 m = ctx->mrec;
1159 a = ctx->attr;
1160 status.attr_switched = 0;
1161 }
1162 }
1163 /*
1164 * If the runlist has been modified, need to restore it by punching a
1165 * hole into it and we then need to deallocate the on-disk cluster as
1166 * well. Note, we only modify the runlist if we are able to generate a
1167 * new mapping pairs array, i.e. only when the mapped attribute extent
1168 * is not switched.
1169 */
1170 if (status.runlist_merged && !status.attr_switched) {
1171 BUG_ON(!rl_write_locked);
1172 /* Make the file cluster we allocated sparse in the runlist. */
1173 if (ntfs_rl_punch_nolock(vol, &ni->runlist, bh_cpos, 1)) {
1174 ntfs_error(vol->sb, "Failed to punch hole into "
1175 "attribute runlist in error code "
1176 "path. Run chkdsk to recover the "
1177 "lost cluster.");
1178 NVolSetErrors(vol);
1179 } else /* if (success) */ {
1180 status.runlist_merged = 0;
1181 /*
1182 * Deallocate the on-disk cluster we allocated but only
1183 * if we succeeded in punching its vcn out of the
1184 * runlist.
1185 */
1186 down_write(&vol->lcnbmp_lock);
1187 if (ntfs_bitmap_clear_bit(vol->lcnbmp_ino, lcn)) {
1188 ntfs_error(vol->sb, "Failed to release "
1189 "allocated cluster in error "
1190 "code path. Run chkdsk to "
1191 "recover the lost cluster.");
1192 NVolSetErrors(vol);
1193 }
1194 up_write(&vol->lcnbmp_lock);
1195 }
1196 }
1197 /*
1198 * Resize the attribute record to its old size and rebuild the mapping
1199 * pairs array. Note, we only can do this if the runlist has been
1200 * restored to its old state which also implies that the mapped
1201 * attribute extent is not switched.
1202 */
1203 if (status.mp_rebuilt && !status.runlist_merged) {
1204 if (ntfs_attr_record_resize(m, a, attr_rec_len)) {
1205 ntfs_error(vol->sb, "Failed to restore attribute "
1206 "record in error code path. Run "
1207 "chkdsk to recover.");
1208 NVolSetErrors(vol);
1209 } else /* if (success) */ {
1210 if (ntfs_mapping_pairs_build(vol, (u8*)a +
1211 le16_to_cpu(a->data.non_resident.
1212 mapping_pairs_offset), attr_rec_len -
1213 le16_to_cpu(a->data.non_resident.
1214 mapping_pairs_offset), ni->runlist.rl,
1215 vcn, highest_vcn, NULL)) {
1216 ntfs_error(vol->sb, "Failed to restore "
1217 "mapping pairs array in error "
1218 "code path. Run chkdsk to "
1219 "recover.");
1220 NVolSetErrors(vol);
1221 }
1222 flush_dcache_mft_record_page(ctx->ntfs_ino);
1223 mark_mft_record_dirty(ctx->ntfs_ino);
1224 }
1225 }
1226 /* Release the mft record and the attribute. */
1227 if (status.mft_attr_mapped) {
1228 ntfs_attr_put_search_ctx(ctx);
1229 unmap_mft_record(base_ni);
1230 }
1231 /* Release the runlist lock. */
1232 if (rl_write_locked)
1233 up_write(&ni->runlist.lock);
1234 else if (rl)
1235 up_read(&ni->runlist.lock);
1236 /*
1237 * Zero out any newly allocated blocks to avoid exposing stale data.
1238 * If BH_New is set, we know that the block was newly allocated above
1239 * and that it has not been fully zeroed and marked dirty yet.
1240 */
1241 nr_pages = u;
1242 u = 0;
1243 end = bh_cpos << vol->cluster_size_bits;
1244 do {
1245 page = pages[u];
1246 bh = head = page_buffers(page);
1247 do {
1248 if (u == nr_pages &&
1249 ((s64)page->index << PAGE_CACHE_SHIFT) +
1250 bh_offset(bh) >= end)
1251 break;
1252 if (!buffer_new(bh))
1253 continue;
1254 clear_buffer_new(bh);
1255 if (!buffer_uptodate(bh)) {
1256 if (PageUptodate(page))
1257 set_buffer_uptodate(bh);
1258 else {
1259 zero_user(page, bh_offset(bh),
1260 blocksize);
1261 set_buffer_uptodate(bh);
1262 }
1263 }
1264 mark_buffer_dirty(bh);
1265 } while ((bh = bh->b_this_page) != head);
1266 } while (++u <= nr_pages);
1267 ntfs_error(vol->sb, "Failed. Returning error code %i.", err);
1268 return err;
1269}
1270
1271/*
1272 * Copy as much as we can into the pages and return the number of bytes which
1273 * were successfully copied. If a fault is encountered then clear the pages
1274 * out to (ofs + bytes) and return the number of bytes which were copied.
1275 */
1276static inline size_t ntfs_copy_from_user(struct page **pages,
1277 unsigned nr_pages, unsigned ofs, const char __user *buf,
1278 size_t bytes)
1279{
1280 struct page **last_page = pages + nr_pages;
1281 char *addr;
1282 size_t total = 0;
1283 unsigned len;
1284 int left;
1285
1286 do {
1287 len = PAGE_CACHE_SIZE - ofs;
1288 if (len > bytes)
1289 len = bytes;
1290 addr = kmap_atomic(*pages);
1291 left = __copy_from_user_inatomic(addr + ofs, buf, len);
1292 kunmap_atomic(addr);
1293 if (unlikely(left)) {
1294 /* Do it the slow way. */
1295 addr = kmap(*pages);
1296 left = __copy_from_user(addr + ofs, buf, len);
1297 kunmap(*pages);
1298 if (unlikely(left))
1299 goto err_out;
1300 }
1301 total += len;
1302 bytes -= len;
1303 if (!bytes)
1304 break;
1305 buf += len;
1306 ofs = 0;
1307 } while (++pages < last_page);
1308out:
1309 return total;
1310err_out:
1311 total += len - left;
1312 /* Zero the rest of the target like __copy_from_user(). */
1313 while (++pages < last_page) {
1314 bytes -= len;
1315 if (!bytes)
1316 break;
1317 len = PAGE_CACHE_SIZE;
1318 if (len > bytes)
1319 len = bytes;
1320 zero_user(*pages, 0, len);
1321 }
1322 goto out;
1323}
1324
1325static size_t __ntfs_copy_from_user_iovec_inatomic(char *vaddr,
1326 const struct iovec *iov, size_t iov_ofs, size_t bytes)
1327{
1328 size_t total = 0;
1329
1330 while (1) {
1331 const char __user *buf = iov->iov_base + iov_ofs;
1332 unsigned len;
1333 size_t left;
1334
1335 len = iov->iov_len - iov_ofs;
1336 if (len > bytes)
1337 len = bytes;
1338 left = __copy_from_user_inatomic(vaddr, buf, len);
1339 total += len;
1340 bytes -= len;
1341 vaddr += len;
1342 if (unlikely(left)) {
1343 total -= left;
1344 break;
1345 }
1346 if (!bytes)
1347 break;
1348 iov++;
1349 iov_ofs = 0;
1350 }
1351 return total;
1352}
1353
1354static inline void ntfs_set_next_iovec(const struct iovec **iovp,
1355 size_t *iov_ofsp, size_t bytes)
1356{
1357 const struct iovec *iov = *iovp;
1358 size_t iov_ofs = *iov_ofsp;
1359
1360 while (bytes) {
1361 unsigned len;
1362
1363 len = iov->iov_len - iov_ofs;
1364 if (len > bytes)
1365 len = bytes;
1366 bytes -= len;
1367 iov_ofs += len;
1368 if (iov->iov_len == iov_ofs) {
1369 iov++;
1370 iov_ofs = 0;
1371 }
1372 }
1373 *iovp = iov;
1374 *iov_ofsp = iov_ofs;
1375}
1376
1377/*
1378 * This has the same side-effects and return value as ntfs_copy_from_user().
1379 * The difference is that on a fault we need to memset the remainder of the
1380 * pages (out to offset + bytes), to emulate ntfs_copy_from_user()'s
1381 * single-segment behaviour.
1382 *
1383 * We call the same helper (__ntfs_copy_from_user_iovec_inatomic()) both when
1384 * atomic and when not atomic. This is ok because it calls
1385 * __copy_from_user_inatomic() and it is ok to call this when non-atomic. In
1386 * fact, the only difference between __copy_from_user_inatomic() and
1387 * __copy_from_user() is that the latter calls might_sleep() and the former
1388 * should not zero the tail of the buffer on error. And on many architectures
1389 * __copy_from_user_inatomic() is just defined to __copy_from_user() so it
1390 * makes no difference at all on those architectures.
1391 */
1392static inline size_t ntfs_copy_from_user_iovec(struct page **pages,
1393 unsigned nr_pages, unsigned ofs, const struct iovec **iov,
1394 size_t *iov_ofs, size_t bytes)
1395{
1396 struct page **last_page = pages + nr_pages;
1397 char *addr;
1398 size_t copied, len, total = 0;
1399
1400 do {
1401 len = PAGE_CACHE_SIZE - ofs;
1402 if (len > bytes)
1403 len = bytes;
1404 addr = kmap_atomic(*pages);
1405 copied = __ntfs_copy_from_user_iovec_inatomic(addr + ofs,
1406 *iov, *iov_ofs, len);
1407 kunmap_atomic(addr);
1408 if (unlikely(copied != len)) {
1409 /* Do it the slow way. */
1410 addr = kmap(*pages);
1411 copied = __ntfs_copy_from_user_iovec_inatomic(addr +
1412 ofs, *iov, *iov_ofs, len);
1413 if (unlikely(copied != len))
1414 goto err_out;
1415 kunmap(*pages);
1416 }
1417 total += len;
1418 ntfs_set_next_iovec(iov, iov_ofs, len);
1419 bytes -= len;
1420 if (!bytes)
1421 break;
1422 ofs = 0;
1423 } while (++pages < last_page);
1424out:
1425 return total;
1426err_out:
1427 BUG_ON(copied > len);
1428 /* Zero the rest of the target like __copy_from_user(). */
1429 memset(addr + ofs + copied, 0, len - copied);
1430 kunmap(*pages);
1431 total += copied;
1432 ntfs_set_next_iovec(iov, iov_ofs, copied);
1433 while (++pages < last_page) {
1434 bytes -= len;
1435 if (!bytes)
1436 break;
1437 len = PAGE_CACHE_SIZE;
1438 if (len > bytes)
1439 len = bytes;
1440 zero_user(*pages, 0, len);
1441 }
1442 goto out;
1443}
1444
1445static inline void ntfs_flush_dcache_pages(struct page **pages,
1446 unsigned nr_pages)
1447{
1448 BUG_ON(!nr_pages);
1449 /*
1450 * Warning: Do not do the decrement at the same time as the call to
1451 * flush_dcache_page() because it is a NULL macro on i386 and hence the
1452 * decrement never happens so the loop never terminates.
1453 */
1454 do {
1455 --nr_pages;
1456 flush_dcache_page(pages[nr_pages]);
1457 } while (nr_pages > 0);
1458}
1459
1460/**
1461 * ntfs_commit_pages_after_non_resident_write - commit the received data
1462 * @pages: array of destination pages
1463 * @nr_pages: number of pages in @pages
1464 * @pos: byte position in file at which the write begins
1465 * @bytes: number of bytes to be written
1466 *
1467 * See description of ntfs_commit_pages_after_write(), below.
1468 */
1469static inline int ntfs_commit_pages_after_non_resident_write(
1470 struct page **pages, const unsigned nr_pages,
1471 s64 pos, size_t bytes)
1472{
1473 s64 end, initialized_size;
1474 struct inode *vi;
1475 ntfs_inode *ni, *base_ni;
1476 struct buffer_head *bh, *head;
1477 ntfs_attr_search_ctx *ctx;
1478 MFT_RECORD *m;
1479 ATTR_RECORD *a;
1480 unsigned long flags;
1481 unsigned blocksize, u;
1482 int err;
1483
1484 vi = pages[0]->mapping->host;
1485 ni = NTFS_I(vi);
1486 blocksize = vi->i_sb->s_blocksize;
1487 end = pos + bytes;
1488 u = 0;
1489 do {
1490 s64 bh_pos;
1491 struct page *page;
1492 bool partial;
1493
1494 page = pages[u];
1495 bh_pos = (s64)page->index << PAGE_CACHE_SHIFT;
1496 bh = head = page_buffers(page);
1497 partial = false;
1498 do {
1499 s64 bh_end;
1500
1501 bh_end = bh_pos + blocksize;
1502 if (bh_end <= pos || bh_pos >= end) {
1503 if (!buffer_uptodate(bh))
1504 partial = true;
1505 } else {
1506 set_buffer_uptodate(bh);
1507 mark_buffer_dirty(bh);
1508 }
1509 } while (bh_pos += blocksize, (bh = bh->b_this_page) != head);
1510 /*
1511 * If all buffers are now uptodate but the page is not, set the
1512 * page uptodate.
1513 */
1514 if (!partial && !PageUptodate(page))
1515 SetPageUptodate(page);
1516 } while (++u < nr_pages);
1517 /*
1518 * Finally, if we do not need to update initialized_size or i_size we
1519 * are finished.
1520 */
1521 read_lock_irqsave(&ni->size_lock, flags);
1522 initialized_size = ni->initialized_size;
1523 read_unlock_irqrestore(&ni->size_lock, flags);
1524 if (end <= initialized_size) {
1525 ntfs_debug("Done.");
1526 return 0;
1527 }
1528 /*
1529 * Update initialized_size/i_size as appropriate, both in the inode and
1530 * the mft record.
1531 */
1532 if (!NInoAttr(ni))
1533 base_ni = ni;
1534 else
1535 base_ni = ni->ext.base_ntfs_ino;
1536 /* Map, pin, and lock the mft record. */
1537 m = map_mft_record(base_ni);
1538 if (IS_ERR(m)) {
1539 err = PTR_ERR(m);
1540 m = NULL;
1541 ctx = NULL;
1542 goto err_out;
1543 }
1544 BUG_ON(!NInoNonResident(ni));
1545 ctx = ntfs_attr_get_search_ctx(base_ni, m);
1546 if (unlikely(!ctx)) {
1547 err = -ENOMEM;
1548 goto err_out;
1549 }
1550 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1551 CASE_SENSITIVE, 0, NULL, 0, ctx);
1552 if (unlikely(err)) {
1553 if (err == -ENOENT)
1554 err = -EIO;
1555 goto err_out;
1556 }
1557 a = ctx->attr;
1558 BUG_ON(!a->non_resident);
1559 write_lock_irqsave(&ni->size_lock, flags);
1560 BUG_ON(end > ni->allocated_size);
1561 ni->initialized_size = end;
1562 a->data.non_resident.initialized_size = cpu_to_sle64(end);
1563 if (end > i_size_read(vi)) {
1564 i_size_write(vi, end);
1565 a->data.non_resident.data_size =
1566 a->data.non_resident.initialized_size;
1567 }
1568 write_unlock_irqrestore(&ni->size_lock, flags);
1569 /* Mark the mft record dirty, so it gets written back. */
1570 flush_dcache_mft_record_page(ctx->ntfs_ino);
1571 mark_mft_record_dirty(ctx->ntfs_ino);
1572 ntfs_attr_put_search_ctx(ctx);
1573 unmap_mft_record(base_ni);
1574 ntfs_debug("Done.");
1575 return 0;
1576err_out:
1577 if (ctx)
1578 ntfs_attr_put_search_ctx(ctx);
1579 if (m)
1580 unmap_mft_record(base_ni);
1581 ntfs_error(vi->i_sb, "Failed to update initialized_size/i_size (error "
1582 "code %i).", err);
1583 if (err != -ENOMEM)
1584 NVolSetErrors(ni->vol);
1585 return err;
1586}
1587
1588/**
1589 * ntfs_commit_pages_after_write - commit the received data
1590 * @pages: array of destination pages
1591 * @nr_pages: number of pages in @pages
1592 * @pos: byte position in file at which the write begins
1593 * @bytes: number of bytes to be written
1594 *
1595 * This is called from ntfs_file_buffered_write() with i_mutex held on the inode
1596 * (@pages[0]->mapping->host). There are @nr_pages pages in @pages which are
1597 * locked but not kmap()ped. The source data has already been copied into the
1598 * @page. ntfs_prepare_pages_for_non_resident_write() has been called before
1599 * the data was copied (for non-resident attributes only) and it returned
1600 * success.
1601 *
1602 * Need to set uptodate and mark dirty all buffers within the boundary of the
1603 * write. If all buffers in a page are uptodate we set the page uptodate, too.
1604 *
1605 * Setting the buffers dirty ensures that they get written out later when
1606 * ntfs_writepage() is invoked by the VM.
1607 *
1608 * Finally, we need to update i_size and initialized_size as appropriate both
1609 * in the inode and the mft record.
1610 *
1611 * This is modelled after fs/buffer.c::generic_commit_write(), which marks
1612 * buffers uptodate and dirty, sets the page uptodate if all buffers in the
1613 * page are uptodate, and updates i_size if the end of io is beyond i_size. In
1614 * that case, it also marks the inode dirty.
1615 *
1616 * If things have gone as outlined in
1617 * ntfs_prepare_pages_for_non_resident_write(), we do not need to do any page
1618 * content modifications here for non-resident attributes. For resident
1619 * attributes we need to do the uptodate bringing here which we combine with
1620 * the copying into the mft record which means we save one atomic kmap.
1621 *
1622 * Return 0 on success or -errno on error.
1623 */
1624static int ntfs_commit_pages_after_write(struct page **pages,
1625 const unsigned nr_pages, s64 pos, size_t bytes)
1626{
1627 s64 end, initialized_size;
1628 loff_t i_size;
1629 struct inode *vi;
1630 ntfs_inode *ni, *base_ni;
1631 struct page *page;
1632 ntfs_attr_search_ctx *ctx;
1633 MFT_RECORD *m;
1634 ATTR_RECORD *a;
1635 char *kattr, *kaddr;
1636 unsigned long flags;
1637 u32 attr_len;
1638 int err;
1639
1640 BUG_ON(!nr_pages);
1641 BUG_ON(!pages);
1642 page = pages[0];
1643 BUG_ON(!page);
1644 vi = page->mapping->host;
1645 ni = NTFS_I(vi);
1646 ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page "
1647 "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.",
1648 vi->i_ino, ni->type, page->index, nr_pages,
1649 (long long)pos, bytes);
1650 if (NInoNonResident(ni))
1651 return ntfs_commit_pages_after_non_resident_write(pages,
1652 nr_pages, pos, bytes);
1653 BUG_ON(nr_pages > 1);
1654 /*
1655 * Attribute is resident, implying it is not compressed, encrypted, or
1656 * sparse.
1657 */
1658 if (!NInoAttr(ni))
1659 base_ni = ni;
1660 else
1661 base_ni = ni->ext.base_ntfs_ino;
1662 BUG_ON(NInoNonResident(ni));
1663 /* Map, pin, and lock the mft record. */
1664 m = map_mft_record(base_ni);
1665 if (IS_ERR(m)) {
1666 err = PTR_ERR(m);
1667 m = NULL;
1668 ctx = NULL;
1669 goto err_out;
1670 }
1671 ctx = ntfs_attr_get_search_ctx(base_ni, m);
1672 if (unlikely(!ctx)) {
1673 err = -ENOMEM;
1674 goto err_out;
1675 }
1676 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1677 CASE_SENSITIVE, 0, NULL, 0, ctx);
1678 if (unlikely(err)) {
1679 if (err == -ENOENT)
1680 err = -EIO;
1681 goto err_out;
1682 }
1683 a = ctx->attr;
1684 BUG_ON(a->non_resident);
1685 /* The total length of the attribute value. */
1686 attr_len = le32_to_cpu(a->data.resident.value_length);
1687 i_size = i_size_read(vi);
1688 BUG_ON(attr_len != i_size);
1689 BUG_ON(pos > attr_len);
1690 end = pos + bytes;
1691 BUG_ON(end > le32_to_cpu(a->length) -
1692 le16_to_cpu(a->data.resident.value_offset));
1693 kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset);
1694 kaddr = kmap_atomic(page);
1695 /* Copy the received data from the page to the mft record. */
1696 memcpy(kattr + pos, kaddr + pos, bytes);
1697 /* Update the attribute length if necessary. */
1698 if (end > attr_len) {
1699 attr_len = end;
1700 a->data.resident.value_length = cpu_to_le32(attr_len);
1701 }
1702 /*
1703 * If the page is not uptodate, bring the out of bounds area(s)
1704 * uptodate by copying data from the mft record to the page.
1705 */
1706 if (!PageUptodate(page)) {
1707 if (pos > 0)
1708 memcpy(kaddr, kattr, pos);
1709 if (end < attr_len)
1710 memcpy(kaddr + end, kattr + end, attr_len - end);
1711 /* Zero the region outside the end of the attribute value. */
1712 memset(kaddr + attr_len, 0, PAGE_CACHE_SIZE - attr_len);
1713 flush_dcache_page(page);
1714 SetPageUptodate(page);
1715 }
1716 kunmap_atomic(kaddr);
1717 /* Update initialized_size/i_size if necessary. */
1718 read_lock_irqsave(&ni->size_lock, flags);
1719 initialized_size = ni->initialized_size;
1720 BUG_ON(end > ni->allocated_size);
1721 read_unlock_irqrestore(&ni->size_lock, flags);
1722 BUG_ON(initialized_size != i_size);
1723 if (end > initialized_size) {
1724 write_lock_irqsave(&ni->size_lock, flags);
1725 ni->initialized_size = end;
1726 i_size_write(vi, end);
1727 write_unlock_irqrestore(&ni->size_lock, flags);
1728 }
1729 /* Mark the mft record dirty, so it gets written back. */
1730 flush_dcache_mft_record_page(ctx->ntfs_ino);
1731 mark_mft_record_dirty(ctx->ntfs_ino);
1732 ntfs_attr_put_search_ctx(ctx);
1733 unmap_mft_record(base_ni);
1734 ntfs_debug("Done.");
1735 return 0;
1736err_out:
1737 if (err == -ENOMEM) {
1738 ntfs_warning(vi->i_sb, "Error allocating memory required to "
1739 "commit the write.");
1740 if (PageUptodate(page)) {
1741 ntfs_warning(vi->i_sb, "Page is uptodate, setting "
1742 "dirty so the write will be retried "
1743 "later on by the VM.");
1744 /*
1745 * Put the page on mapping->dirty_pages, but leave its
1746 * buffers' dirty state as-is.
1747 */
1748 __set_page_dirty_nobuffers(page);
1749 err = 0;
1750 } else
1751 ntfs_error(vi->i_sb, "Page is not uptodate. Written "
1752 "data has been lost.");
1753 } else {
1754 ntfs_error(vi->i_sb, "Resident attribute commit write failed "
1755 "with error %i.", err);
1756 NVolSetErrors(ni->vol);
1757 }
1758 if (ctx)
1759 ntfs_attr_put_search_ctx(ctx);
1760 if (m)
1761 unmap_mft_record(base_ni);
1762 return err;
1763}
1764
1765/**
1766 * ntfs_file_buffered_write -
1767 *
1768 * Locking: The vfs is holding ->i_mutex on the inode.
1769 */
1770static ssize_t ntfs_file_buffered_write(struct kiocb *iocb,
1771 const struct iovec *iov, unsigned long nr_segs,
1772 loff_t pos, loff_t *ppos, size_t count)
1773{
1774 struct file *file = iocb->ki_filp;
1775 struct address_space *mapping = file->f_mapping;
1776 struct inode *vi = mapping->host;
1777 ntfs_inode *ni = NTFS_I(vi);
1778 ntfs_volume *vol = ni->vol;
1779 struct page *pages[NTFS_MAX_PAGES_PER_CLUSTER];
1780 struct page *cached_page = NULL;
1781 char __user *buf = NULL;
1782 s64 end, ll;
1783 VCN last_vcn;
1784 LCN lcn;
1785 unsigned long flags;
1786 size_t bytes, iov_ofs = 0; /* Offset in the current iovec. */
1787 ssize_t status, written;
1788 unsigned nr_pages;
1789 int err;
1790
1791 ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, "
1792 "pos 0x%llx, count 0x%lx.",
1793 vi->i_ino, (unsigned)le32_to_cpu(ni->type),
1794 (unsigned long long)pos, (unsigned long)count);
1795 if (unlikely(!count))
1796 return 0;
1797 BUG_ON(NInoMstProtected(ni));
1798 /*
1799 * If the attribute is not an index root and it is encrypted or
1800 * compressed, we cannot write to it yet. Note we need to check for
1801 * AT_INDEX_ALLOCATION since this is the type of both directory and
1802 * index inodes.
1803 */
1804 if (ni->type != AT_INDEX_ALLOCATION) {
1805 /* If file is encrypted, deny access, just like NT4. */
1806 if (NInoEncrypted(ni)) {
1807 /*
1808 * Reminder for later: Encrypted files are _always_
1809 * non-resident so that the content can always be
1810 * encrypted.
1811 */
1812 ntfs_debug("Denying write access to encrypted file.");
1813 return -EACCES;
1814 }
1815 if (NInoCompressed(ni)) {
1816 /* Only unnamed $DATA attribute can be compressed. */
1817 BUG_ON(ni->type != AT_DATA);
1818 BUG_ON(ni->name_len);
1819 /*
1820 * Reminder for later: If resident, the data is not
1821 * actually compressed. Only on the switch to non-
1822 * resident does compression kick in. This is in
1823 * contrast to encrypted files (see above).
1824 */
1825 ntfs_error(vi->i_sb, "Writing to compressed files is "
1826 "not implemented yet. Sorry.");
1827 return -EOPNOTSUPP;
1828 }
1829 }
1830 /*
1831 * If a previous ntfs_truncate() failed, repeat it and abort if it
1832 * fails again.
1833 */
1834 if (unlikely(NInoTruncateFailed(ni))) {
1835 inode_dio_wait(vi);
1836 err = ntfs_truncate(vi);
1837 if (err || NInoTruncateFailed(ni)) {
1838 if (!err)
1839 err = -EIO;
1840 ntfs_error(vol->sb, "Cannot perform write to inode "
1841 "0x%lx, attribute type 0x%x, because "
1842 "ntfs_truncate() failed (error code "
1843 "%i).", vi->i_ino,
1844 (unsigned)le32_to_cpu(ni->type), err);
1845 return err;
1846 }
1847 }
1848 /* The first byte after the write. */
1849 end = pos + count;
1850 /*
1851 * If the write goes beyond the allocated size, extend the allocation
1852 * to cover the whole of the write, rounded up to the nearest cluster.
1853 */
1854 read_lock_irqsave(&ni->size_lock, flags);
1855 ll = ni->allocated_size;
1856 read_unlock_irqrestore(&ni->size_lock, flags);
1857 if (end > ll) {
1858 /* Extend the allocation without changing the data size. */
1859 ll = ntfs_attr_extend_allocation(ni, end, -1, pos);
1860 if (likely(ll >= 0)) {
1861 BUG_ON(pos >= ll);
1862 /* If the extension was partial truncate the write. */
1863 if (end > ll) {
1864 ntfs_debug("Truncating write to inode 0x%lx, "
1865 "attribute type 0x%x, because "
1866 "the allocation was only "
1867 "partially extended.",
1868 vi->i_ino, (unsigned)
1869 le32_to_cpu(ni->type));
1870 end = ll;
1871 count = ll - pos;
1872 }
1873 } else {
1874 err = ll;
1875 read_lock_irqsave(&ni->size_lock, flags);
1876 ll = ni->allocated_size;
1877 read_unlock_irqrestore(&ni->size_lock, flags);
1878 /* Perform a partial write if possible or fail. */
1879 if (pos < ll) {
1880 ntfs_debug("Truncating write to inode 0x%lx, "
1881 "attribute type 0x%x, because "
1882 "extending the allocation "
1883 "failed (error code %i).",
1884 vi->i_ino, (unsigned)
1885 le32_to_cpu(ni->type), err);
1886 end = ll;
1887 count = ll - pos;
1888 } else {
1889 ntfs_error(vol->sb, "Cannot perform write to "
1890 "inode 0x%lx, attribute type "
1891 "0x%x, because extending the "
1892 "allocation failed (error "
1893 "code %i).", vi->i_ino,
1894 (unsigned)
1895 le32_to_cpu(ni->type), err);
1896 return err;
1897 }
1898 }
1899 }
1900 written = 0;
1901 /*
1902 * If the write starts beyond the initialized size, extend it up to the
1903 * beginning of the write and initialize all non-sparse space between
1904 * the old initialized size and the new one. This automatically also
1905 * increments the vfs inode->i_size to keep it above or equal to the
1906 * initialized_size.
1907 */
1908 read_lock_irqsave(&ni->size_lock, flags);
1909 ll = ni->initialized_size;
1910 read_unlock_irqrestore(&ni->size_lock, flags);
1911 if (pos > ll) {
1912 err = ntfs_attr_extend_initialized(ni, pos);
1913 if (err < 0) {
1914 ntfs_error(vol->sb, "Cannot perform write to inode "
1915 "0x%lx, attribute type 0x%x, because "
1916 "extending the initialized size "
1917 "failed (error code %i).", vi->i_ino,
1918 (unsigned)le32_to_cpu(ni->type), err);
1919 status = err;
1920 goto err_out;
1921 }
1922 }
1923 /*
1924 * Determine the number of pages per cluster for non-resident
1925 * attributes.
1926 */
1927 nr_pages = 1;
1928 if (vol->cluster_size > PAGE_CACHE_SIZE && NInoNonResident(ni))
1929 nr_pages = vol->cluster_size >> PAGE_CACHE_SHIFT;
1930 /* Finally, perform the actual write. */
1931 last_vcn = -1;
1932 if (likely(nr_segs == 1))
1933 buf = iov->iov_base;
1934 do {
1935 VCN vcn;
1936 pgoff_t idx, start_idx;
1937 unsigned ofs, do_pages, u;
1938 size_t copied;
1939
1940 start_idx = idx = pos >> PAGE_CACHE_SHIFT;
1941 ofs = pos & ~PAGE_CACHE_MASK;
1942 bytes = PAGE_CACHE_SIZE - ofs;
1943 do_pages = 1;
1944 if (nr_pages > 1) {
1945 vcn = pos >> vol->cluster_size_bits;
1946 if (vcn != last_vcn) {
1947 last_vcn = vcn;
1948 /*
1949 * Get the lcn of the vcn the write is in. If
1950 * it is a hole, need to lock down all pages in
1951 * the cluster.
1952 */
1953 down_read(&ni->runlist.lock);
1954 lcn = ntfs_attr_vcn_to_lcn_nolock(ni, pos >>
1955 vol->cluster_size_bits, false);
1956 up_read(&ni->runlist.lock);
1957 if (unlikely(lcn < LCN_HOLE)) {
1958 status = -EIO;
1959 if (lcn == LCN_ENOMEM)
1960 status = -ENOMEM;
1961 else
1962 ntfs_error(vol->sb, "Cannot "
1963 "perform write to "
1964 "inode 0x%lx, "
1965 "attribute type 0x%x, "
1966 "because the attribute "
1967 "is corrupt.",
1968 vi->i_ino, (unsigned)
1969 le32_to_cpu(ni->type));
1970 break;
1971 }
1972 if (lcn == LCN_HOLE) {
1973 start_idx = (pos & ~(s64)
1974 vol->cluster_size_mask)
1975 >> PAGE_CACHE_SHIFT;
1976 bytes = vol->cluster_size - (pos &
1977 vol->cluster_size_mask);
1978 do_pages = nr_pages;
1979 }
1980 }
1981 }
1982 if (bytes > count)
1983 bytes = count;
1984 /*
1985 * Bring in the user page(s) that we will copy from _first_.
1986 * Otherwise there is a nasty deadlock on copying from the same
1987 * page(s) as we are writing to, without it/them being marked
1988 * up-to-date. Note, at present there is nothing to stop the
1989 * pages being swapped out between us bringing them into memory
1990 * and doing the actual copying.
1991 */
1992 if (likely(nr_segs == 1))
1993 ntfs_fault_in_pages_readable(buf, bytes);
1994 else
1995 ntfs_fault_in_pages_readable_iovec(iov, iov_ofs, bytes);
1996 /* Get and lock @do_pages starting at index @start_idx. */
1997 status = __ntfs_grab_cache_pages(mapping, start_idx, do_pages,
1998 pages, &cached_page);
1999 if (unlikely(status))
2000 break;
2001 /*
2002 * For non-resident attributes, we need to fill any holes with
2003 * actual clusters and ensure all bufferes are mapped. We also
2004 * need to bring uptodate any buffers that are only partially
2005 * being written to.
2006 */
2007 if (NInoNonResident(ni)) {
2008 status = ntfs_prepare_pages_for_non_resident_write(
2009 pages, do_pages, pos, bytes);
2010 if (unlikely(status)) {
2011 loff_t i_size;
2012
2013 do {
2014 unlock_page(pages[--do_pages]);
2015 page_cache_release(pages[do_pages]);
2016 } while (do_pages);
2017 /*
2018 * The write preparation may have instantiated
2019 * allocated space outside i_size. Trim this
2020 * off again. We can ignore any errors in this
2021 * case as we will just be waisting a bit of
2022 * allocated space, which is not a disaster.
2023 */
2024 i_size = i_size_read(vi);
2025 if (pos + bytes > i_size)
2026 vmtruncate(vi, i_size);
2027 break;
2028 }
2029 }
2030 u = (pos >> PAGE_CACHE_SHIFT) - pages[0]->index;
2031 if (likely(nr_segs == 1)) {
2032 copied = ntfs_copy_from_user(pages + u, do_pages - u,
2033 ofs, buf, bytes);
2034 buf += copied;
2035 } else
2036 copied = ntfs_copy_from_user_iovec(pages + u,
2037 do_pages - u, ofs, &iov, &iov_ofs,
2038 bytes);
2039 ntfs_flush_dcache_pages(pages + u, do_pages - u);
2040 status = ntfs_commit_pages_after_write(pages, do_pages, pos,
2041 bytes);
2042 if (likely(!status)) {
2043 written += copied;
2044 count -= copied;
2045 pos += copied;
2046 if (unlikely(copied != bytes))
2047 status = -EFAULT;
2048 }
2049 do {
2050 unlock_page(pages[--do_pages]);
2051 mark_page_accessed(pages[do_pages]);
2052 page_cache_release(pages[do_pages]);
2053 } while (do_pages);
2054 if (unlikely(status))
2055 break;
2056 balance_dirty_pages_ratelimited(mapping);
2057 cond_resched();
2058 } while (count);
2059err_out:
2060 *ppos = pos;
2061 if (cached_page)
2062 page_cache_release(cached_page);
2063 ntfs_debug("Done. Returning %s (written 0x%lx, status %li).",
2064 written ? "written" : "status", (unsigned long)written,
2065 (long)status);
2066 return written ? written : status;
2067}
2068
2069/**
2070 * ntfs_file_aio_write_nolock -
2071 */
2072static ssize_t ntfs_file_aio_write_nolock(struct kiocb *iocb,
2073 const struct iovec *iov, unsigned long nr_segs, loff_t *ppos)
2074{
2075 struct file *file = iocb->ki_filp;
2076 struct address_space *mapping = file->f_mapping;
2077 struct inode *inode = mapping->host;
2078 loff_t pos;
2079 size_t count; /* after file limit checks */
2080 ssize_t written, err;
2081
2082 count = 0;
2083 err = generic_segment_checks(iov, &nr_segs, &count, VERIFY_READ);
2084 if (err)
2085 return err;
2086 pos = *ppos;
2087 vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
2088 /* We can write back this queue in page reclaim. */
2089 current->backing_dev_info = mapping->backing_dev_info;
2090 written = 0;
2091 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
2092 if (err)
2093 goto out;
2094 if (!count)
2095 goto out;
2096 err = file_remove_suid(file);
2097 if (err)
2098 goto out;
2099 err = file_update_time(file);
2100 if (err)
2101 goto out;
2102 written = ntfs_file_buffered_write(iocb, iov, nr_segs, pos, ppos,
2103 count);
2104out:
2105 current->backing_dev_info = NULL;
2106 return written ? written : err;
2107}
2108
2109/**
2110 * ntfs_file_aio_write -
2111 */
2112static ssize_t ntfs_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
2113 unsigned long nr_segs, loff_t pos)
2114{
2115 struct file *file = iocb->ki_filp;
2116 struct address_space *mapping = file->f_mapping;
2117 struct inode *inode = mapping->host;
2118 ssize_t ret;
2119
2120 BUG_ON(iocb->ki_pos != pos);
2121
2122 mutex_lock(&inode->i_mutex);
2123 ret = ntfs_file_aio_write_nolock(iocb, iov, nr_segs, &iocb->ki_pos);
2124 mutex_unlock(&inode->i_mutex);
2125 if (ret > 0) {
2126 int err = generic_write_sync(file, pos, ret);
2127 if (err < 0)
2128 ret = err;
2129 }
2130 return ret;
2131}
2132
2133/**
2134 * ntfs_file_fsync - sync a file to disk
2135 * @filp: file to be synced
2136 * @datasync: if non-zero only flush user data and not metadata
2137 *
2138 * Data integrity sync of a file to disk. Used for fsync, fdatasync, and msync
2139 * system calls. This function is inspired by fs/buffer.c::file_fsync().
2140 *
2141 * If @datasync is false, write the mft record and all associated extent mft
2142 * records as well as the $DATA attribute and then sync the block device.
2143 *
2144 * If @datasync is true and the attribute is non-resident, we skip the writing
2145 * of the mft record and all associated extent mft records (this might still
2146 * happen due to the write_inode_now() call).
2147 *
2148 * Also, if @datasync is true, we do not wait on the inode to be written out
2149 * but we always wait on the page cache pages to be written out.
2150 *
2151 * Locking: Caller must hold i_mutex on the inode.
2152 *
2153 * TODO: We should probably also write all attribute/index inodes associated
2154 * with this inode but since we have no simple way of getting to them we ignore
2155 * this problem for now.
2156 */
2157static int ntfs_file_fsync(struct file *filp, loff_t start, loff_t end,
2158 int datasync)
2159{
2160 struct inode *vi = filp->f_mapping->host;
2161 int err, ret = 0;
2162
2163 ntfs_debug("Entering for inode 0x%lx.", vi->i_ino);
2164
2165 err = filemap_write_and_wait_range(vi->i_mapping, start, end);
2166 if (err)
2167 return err;
2168 mutex_lock(&vi->i_mutex);
2169
2170 BUG_ON(S_ISDIR(vi->i_mode));
2171 if (!datasync || !NInoNonResident(NTFS_I(vi)))
2172 ret = __ntfs_write_inode(vi, 1);
2173 write_inode_now(vi, !datasync);
2174 /*
2175 * NOTE: If we were to use mapping->private_list (see ext2 and
2176 * fs/buffer.c) for dirty blocks then we could optimize the below to be
2177 * sync_mapping_buffers(vi->i_mapping).
2178 */
2179 err = sync_blockdev(vi->i_sb->s_bdev);
2180 if (unlikely(err && !ret))
2181 ret = err;
2182 if (likely(!ret))
2183 ntfs_debug("Done.");
2184 else
2185 ntfs_warning(vi->i_sb, "Failed to f%ssync inode 0x%lx. Error "
2186 "%u.", datasync ? "data" : "", vi->i_ino, -ret);
2187 mutex_unlock(&vi->i_mutex);
2188 return ret;
2189}
2190
2191#endif /* NTFS_RW */
2192
2193const struct file_operations ntfs_file_ops = {
2194 .llseek = generic_file_llseek, /* Seek inside file. */
2195 .read = do_sync_read, /* Read from file. */
2196 .aio_read = generic_file_aio_read, /* Async read from file. */
2197#ifdef NTFS_RW
2198 .write = do_sync_write, /* Write to file. */
2199 .aio_write = ntfs_file_aio_write, /* Async write to file. */
2200 /*.release = ,*/ /* Last file is closed. See
2201 fs/ext2/file.c::
2202 ext2_release_file() for
2203 how to use this to discard
2204 preallocated space for
2205 write opened files. */
2206 .fsync = ntfs_file_fsync, /* Sync a file to disk. */
2207 /*.aio_fsync = ,*/ /* Sync all outstanding async
2208 i/o operations on a
2209 kiocb. */
2210#endif /* NTFS_RW */
2211 /*.ioctl = ,*/ /* Perform function on the
2212 mounted filesystem. */
2213 .mmap = generic_file_mmap, /* Mmap file. */
2214 .open = ntfs_file_open, /* Open file. */
2215 .splice_read = generic_file_splice_read /* Zero-copy data send with
2216 the data source being on
2217 the ntfs partition. We do
2218 not need to care about the
2219 data destination. */
2220 /*.sendpage = ,*/ /* Zero-copy data send with
2221 the data destination being
2222 on the ntfs partition. We
2223 do not need to care about
2224 the data source. */
2225};
2226
2227const struct inode_operations ntfs_file_inode_ops = {
2228#ifdef NTFS_RW
2229 .truncate = ntfs_truncate_vfs,
2230 .setattr = ntfs_setattr,
2231#endif /* NTFS_RW */
2232};
2233
2234const struct file_operations ntfs_empty_file_ops = {};
2235
2236const struct inode_operations ntfs_empty_inode_ops = {};