Loading...
Note: File does not exist in v6.13.7.
1/**
2 * mft.c - NTFS kernel mft record operations. Part of the Linux-NTFS project.
3 *
4 * Copyright (c) 2001-2012 Anton Altaparmakov and Tuxera Inc.
5 * Copyright (c) 2002 Richard Russon
6 *
7 * This program/include file is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as published
9 * by the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program/include file is distributed in the hope that it will be
13 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program (in the main directory of the Linux-NTFS
19 * distribution in the file COPYING); if not, write to the Free Software
20 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23#include <linux/buffer_head.h>
24#include <linux/slab.h>
25#include <linux/swap.h>
26#include <linux/bio.h>
27
28#include "attrib.h"
29#include "aops.h"
30#include "bitmap.h"
31#include "debug.h"
32#include "dir.h"
33#include "lcnalloc.h"
34#include "malloc.h"
35#include "mft.h"
36#include "ntfs.h"
37
38/**
39 * map_mft_record_page - map the page in which a specific mft record resides
40 * @ni: ntfs inode whose mft record page to map
41 *
42 * This maps the page in which the mft record of the ntfs inode @ni is situated
43 * and returns a pointer to the mft record within the mapped page.
44 *
45 * Return value needs to be checked with IS_ERR() and if that is true PTR_ERR()
46 * contains the negative error code returned.
47 */
48static inline MFT_RECORD *map_mft_record_page(ntfs_inode *ni)
49{
50 loff_t i_size;
51 ntfs_volume *vol = ni->vol;
52 struct inode *mft_vi = vol->mft_ino;
53 struct page *page;
54 unsigned long index, end_index;
55 unsigned ofs;
56
57 BUG_ON(ni->page);
58 /*
59 * The index into the page cache and the offset within the page cache
60 * page of the wanted mft record. FIXME: We need to check for
61 * overflowing the unsigned long, but I don't think we would ever get
62 * here if the volume was that big...
63 */
64 index = (u64)ni->mft_no << vol->mft_record_size_bits >>
65 PAGE_SHIFT;
66 ofs = (ni->mft_no << vol->mft_record_size_bits) & ~PAGE_MASK;
67
68 i_size = i_size_read(mft_vi);
69 /* The maximum valid index into the page cache for $MFT's data. */
70 end_index = i_size >> PAGE_SHIFT;
71
72 /* If the wanted index is out of bounds the mft record doesn't exist. */
73 if (unlikely(index >= end_index)) {
74 if (index > end_index || (i_size & ~PAGE_MASK) < ofs +
75 vol->mft_record_size) {
76 page = ERR_PTR(-ENOENT);
77 ntfs_error(vol->sb, "Attempt to read mft record 0x%lx, "
78 "which is beyond the end of the mft. "
79 "This is probably a bug in the ntfs "
80 "driver.", ni->mft_no);
81 goto err_out;
82 }
83 }
84 /* Read, map, and pin the page. */
85 page = ntfs_map_page(mft_vi->i_mapping, index);
86 if (likely(!IS_ERR(page))) {
87 /* Catch multi sector transfer fixup errors. */
88 if (likely(ntfs_is_mft_recordp((le32*)(page_address(page) +
89 ofs)))) {
90 ni->page = page;
91 ni->page_ofs = ofs;
92 return page_address(page) + ofs;
93 }
94 ntfs_error(vol->sb, "Mft record 0x%lx is corrupt. "
95 "Run chkdsk.", ni->mft_no);
96 ntfs_unmap_page(page);
97 page = ERR_PTR(-EIO);
98 NVolSetErrors(vol);
99 }
100err_out:
101 ni->page = NULL;
102 ni->page_ofs = 0;
103 return (void*)page;
104}
105
106/**
107 * map_mft_record - map, pin and lock an mft record
108 * @ni: ntfs inode whose MFT record to map
109 *
110 * First, take the mrec_lock mutex. We might now be sleeping, while waiting
111 * for the mutex if it was already locked by someone else.
112 *
113 * The page of the record is mapped using map_mft_record_page() before being
114 * returned to the caller.
115 *
116 * This in turn uses ntfs_map_page() to get the page containing the wanted mft
117 * record (it in turn calls read_cache_page() which reads it in from disk if
118 * necessary, increments the use count on the page so that it cannot disappear
119 * under us and returns a reference to the page cache page).
120 *
121 * If read_cache_page() invokes ntfs_readpage() to load the page from disk, it
122 * sets PG_locked and clears PG_uptodate on the page. Once I/O has completed
123 * and the post-read mst fixups on each mft record in the page have been
124 * performed, the page gets PG_uptodate set and PG_locked cleared (this is done
125 * in our asynchronous I/O completion handler end_buffer_read_mft_async()).
126 * ntfs_map_page() waits for PG_locked to become clear and checks if
127 * PG_uptodate is set and returns an error code if not. This provides
128 * sufficient protection against races when reading/using the page.
129 *
130 * However there is the write mapping to think about. Doing the above described
131 * checking here will be fine, because when initiating the write we will set
132 * PG_locked and clear PG_uptodate making sure nobody is touching the page
133 * contents. Doing the locking this way means that the commit to disk code in
134 * the page cache code paths is automatically sufficiently locked with us as
135 * we will not touch a page that has been locked or is not uptodate. The only
136 * locking problem then is them locking the page while we are accessing it.
137 *
138 * So that code will end up having to own the mrec_lock of all mft
139 * records/inodes present in the page before I/O can proceed. In that case we
140 * wouldn't need to bother with PG_locked and PG_uptodate as nobody will be
141 * accessing anything without owning the mrec_lock mutex. But we do need to
142 * use them because of the read_cache_page() invocation and the code becomes so
143 * much simpler this way that it is well worth it.
144 *
145 * The mft record is now ours and we return a pointer to it. You need to check
146 * the returned pointer with IS_ERR() and if that is true, PTR_ERR() will return
147 * the error code.
148 *
149 * NOTE: Caller is responsible for setting the mft record dirty before calling
150 * unmap_mft_record(). This is obviously only necessary if the caller really
151 * modified the mft record...
152 * Q: Do we want to recycle one of the VFS inode state bits instead?
153 * A: No, the inode ones mean we want to change the mft record, not we want to
154 * write it out.
155 */
156MFT_RECORD *map_mft_record(ntfs_inode *ni)
157{
158 MFT_RECORD *m;
159
160 ntfs_debug("Entering for mft_no 0x%lx.", ni->mft_no);
161
162 /* Make sure the ntfs inode doesn't go away. */
163 atomic_inc(&ni->count);
164
165 /* Serialize access to this mft record. */
166 mutex_lock(&ni->mrec_lock);
167
168 m = map_mft_record_page(ni);
169 if (likely(!IS_ERR(m)))
170 return m;
171
172 mutex_unlock(&ni->mrec_lock);
173 atomic_dec(&ni->count);
174 ntfs_error(ni->vol->sb, "Failed with error code %lu.", -PTR_ERR(m));
175 return m;
176}
177
178/**
179 * unmap_mft_record_page - unmap the page in which a specific mft record resides
180 * @ni: ntfs inode whose mft record page to unmap
181 *
182 * This unmaps the page in which the mft record of the ntfs inode @ni is
183 * situated and returns. This is a NOOP if highmem is not configured.
184 *
185 * The unmap happens via ntfs_unmap_page() which in turn decrements the use
186 * count on the page thus releasing it from the pinned state.
187 *
188 * We do not actually unmap the page from memory of course, as that will be
189 * done by the page cache code itself when memory pressure increases or
190 * whatever.
191 */
192static inline void unmap_mft_record_page(ntfs_inode *ni)
193{
194 BUG_ON(!ni->page);
195
196 // TODO: If dirty, blah...
197 ntfs_unmap_page(ni->page);
198 ni->page = NULL;
199 ni->page_ofs = 0;
200 return;
201}
202
203/**
204 * unmap_mft_record - release a mapped mft record
205 * @ni: ntfs inode whose MFT record to unmap
206 *
207 * We release the page mapping and the mrec_lock mutex which unmaps the mft
208 * record and releases it for others to get hold of. We also release the ntfs
209 * inode by decrementing the ntfs inode reference count.
210 *
211 * NOTE: If caller has modified the mft record, it is imperative to set the mft
212 * record dirty BEFORE calling unmap_mft_record().
213 */
214void unmap_mft_record(ntfs_inode *ni)
215{
216 struct page *page = ni->page;
217
218 BUG_ON(!page);
219
220 ntfs_debug("Entering for mft_no 0x%lx.", ni->mft_no);
221
222 unmap_mft_record_page(ni);
223 mutex_unlock(&ni->mrec_lock);
224 atomic_dec(&ni->count);
225 /*
226 * If pure ntfs_inode, i.e. no vfs inode attached, we leave it to
227 * ntfs_clear_extent_inode() in the extent inode case, and to the
228 * caller in the non-extent, yet pure ntfs inode case, to do the actual
229 * tear down of all structures and freeing of all allocated memory.
230 */
231 return;
232}
233
234/**
235 * map_extent_mft_record - load an extent inode and attach it to its base
236 * @base_ni: base ntfs inode
237 * @mref: mft reference of the extent inode to load
238 * @ntfs_ino: on successful return, pointer to the ntfs_inode structure
239 *
240 * Load the extent mft record @mref and attach it to its base inode @base_ni.
241 * Return the mapped extent mft record if IS_ERR(result) is false. Otherwise
242 * PTR_ERR(result) gives the negative error code.
243 *
244 * On successful return, @ntfs_ino contains a pointer to the ntfs_inode
245 * structure of the mapped extent inode.
246 */
247MFT_RECORD *map_extent_mft_record(ntfs_inode *base_ni, MFT_REF mref,
248 ntfs_inode **ntfs_ino)
249{
250 MFT_RECORD *m;
251 ntfs_inode *ni = NULL;
252 ntfs_inode **extent_nis = NULL;
253 int i;
254 unsigned long mft_no = MREF(mref);
255 u16 seq_no = MSEQNO(mref);
256 bool destroy_ni = false;
257
258 ntfs_debug("Mapping extent mft record 0x%lx (base mft record 0x%lx).",
259 mft_no, base_ni->mft_no);
260 /* Make sure the base ntfs inode doesn't go away. */
261 atomic_inc(&base_ni->count);
262 /*
263 * Check if this extent inode has already been added to the base inode,
264 * in which case just return it. If not found, add it to the base
265 * inode before returning it.
266 */
267 mutex_lock(&base_ni->extent_lock);
268 if (base_ni->nr_extents > 0) {
269 extent_nis = base_ni->ext.extent_ntfs_inos;
270 for (i = 0; i < base_ni->nr_extents; i++) {
271 if (mft_no != extent_nis[i]->mft_no)
272 continue;
273 ni = extent_nis[i];
274 /* Make sure the ntfs inode doesn't go away. */
275 atomic_inc(&ni->count);
276 break;
277 }
278 }
279 if (likely(ni != NULL)) {
280 mutex_unlock(&base_ni->extent_lock);
281 atomic_dec(&base_ni->count);
282 /* We found the record; just have to map and return it. */
283 m = map_mft_record(ni);
284 /* map_mft_record() has incremented this on success. */
285 atomic_dec(&ni->count);
286 if (likely(!IS_ERR(m))) {
287 /* Verify the sequence number. */
288 if (likely(le16_to_cpu(m->sequence_number) == seq_no)) {
289 ntfs_debug("Done 1.");
290 *ntfs_ino = ni;
291 return m;
292 }
293 unmap_mft_record(ni);
294 ntfs_error(base_ni->vol->sb, "Found stale extent mft "
295 "reference! Corrupt filesystem. "
296 "Run chkdsk.");
297 return ERR_PTR(-EIO);
298 }
299map_err_out:
300 ntfs_error(base_ni->vol->sb, "Failed to map extent "
301 "mft record, error code %ld.", -PTR_ERR(m));
302 return m;
303 }
304 /* Record wasn't there. Get a new ntfs inode and initialize it. */
305 ni = ntfs_new_extent_inode(base_ni->vol->sb, mft_no);
306 if (unlikely(!ni)) {
307 mutex_unlock(&base_ni->extent_lock);
308 atomic_dec(&base_ni->count);
309 return ERR_PTR(-ENOMEM);
310 }
311 ni->vol = base_ni->vol;
312 ni->seq_no = seq_no;
313 ni->nr_extents = -1;
314 ni->ext.base_ntfs_ino = base_ni;
315 /* Now map the record. */
316 m = map_mft_record(ni);
317 if (IS_ERR(m)) {
318 mutex_unlock(&base_ni->extent_lock);
319 atomic_dec(&base_ni->count);
320 ntfs_clear_extent_inode(ni);
321 goto map_err_out;
322 }
323 /* Verify the sequence number if it is present. */
324 if (seq_no && (le16_to_cpu(m->sequence_number) != seq_no)) {
325 ntfs_error(base_ni->vol->sb, "Found stale extent mft "
326 "reference! Corrupt filesystem. Run chkdsk.");
327 destroy_ni = true;
328 m = ERR_PTR(-EIO);
329 goto unm_err_out;
330 }
331 /* Attach extent inode to base inode, reallocating memory if needed. */
332 if (!(base_ni->nr_extents & 3)) {
333 ntfs_inode **tmp;
334 int new_size = (base_ni->nr_extents + 4) * sizeof(ntfs_inode *);
335
336 tmp = kmalloc(new_size, GFP_NOFS);
337 if (unlikely(!tmp)) {
338 ntfs_error(base_ni->vol->sb, "Failed to allocate "
339 "internal buffer.");
340 destroy_ni = true;
341 m = ERR_PTR(-ENOMEM);
342 goto unm_err_out;
343 }
344 if (base_ni->nr_extents) {
345 BUG_ON(!base_ni->ext.extent_ntfs_inos);
346 memcpy(tmp, base_ni->ext.extent_ntfs_inos, new_size -
347 4 * sizeof(ntfs_inode *));
348 kfree(base_ni->ext.extent_ntfs_inos);
349 }
350 base_ni->ext.extent_ntfs_inos = tmp;
351 }
352 base_ni->ext.extent_ntfs_inos[base_ni->nr_extents++] = ni;
353 mutex_unlock(&base_ni->extent_lock);
354 atomic_dec(&base_ni->count);
355 ntfs_debug("Done 2.");
356 *ntfs_ino = ni;
357 return m;
358unm_err_out:
359 unmap_mft_record(ni);
360 mutex_unlock(&base_ni->extent_lock);
361 atomic_dec(&base_ni->count);
362 /*
363 * If the extent inode was not attached to the base inode we need to
364 * release it or we will leak memory.
365 */
366 if (destroy_ni)
367 ntfs_clear_extent_inode(ni);
368 return m;
369}
370
371#ifdef NTFS_RW
372
373/**
374 * __mark_mft_record_dirty - set the mft record and the page containing it dirty
375 * @ni: ntfs inode describing the mapped mft record
376 *
377 * Internal function. Users should call mark_mft_record_dirty() instead.
378 *
379 * Set the mapped (extent) mft record of the (base or extent) ntfs inode @ni,
380 * as well as the page containing the mft record, dirty. Also, mark the base
381 * vfs inode dirty. This ensures that any changes to the mft record are
382 * written out to disk.
383 *
384 * NOTE: We only set I_DIRTY_DATASYNC (and not I_DIRTY_PAGES)
385 * on the base vfs inode, because even though file data may have been modified,
386 * it is dirty in the inode meta data rather than the data page cache of the
387 * inode, and thus there are no data pages that need writing out. Therefore, a
388 * full mark_inode_dirty() is overkill. A mark_inode_dirty_sync(), on the
389 * other hand, is not sufficient, because ->write_inode needs to be called even
390 * in case of fdatasync. This needs to happen or the file data would not
391 * necessarily hit the device synchronously, even though the vfs inode has the
392 * O_SYNC flag set. Also, I_DIRTY_DATASYNC simply "feels" better than just
393 * I_DIRTY_SYNC, since the file data has not actually hit the block device yet,
394 * which is not what I_DIRTY_SYNC on its own would suggest.
395 */
396void __mark_mft_record_dirty(ntfs_inode *ni)
397{
398 ntfs_inode *base_ni;
399
400 ntfs_debug("Entering for inode 0x%lx.", ni->mft_no);
401 BUG_ON(NInoAttr(ni));
402 mark_ntfs_record_dirty(ni->page, ni->page_ofs);
403 /* Determine the base vfs inode and mark it dirty, too. */
404 mutex_lock(&ni->extent_lock);
405 if (likely(ni->nr_extents >= 0))
406 base_ni = ni;
407 else
408 base_ni = ni->ext.base_ntfs_ino;
409 mutex_unlock(&ni->extent_lock);
410 __mark_inode_dirty(VFS_I(base_ni), I_DIRTY_DATASYNC);
411}
412
413static const char *ntfs_please_email = "Please email "
414 "linux-ntfs-dev@lists.sourceforge.net and say that you saw "
415 "this message. Thank you.";
416
417/**
418 * ntfs_sync_mft_mirror_umount - synchronise an mft record to the mft mirror
419 * @vol: ntfs volume on which the mft record to synchronize resides
420 * @mft_no: mft record number of mft record to synchronize
421 * @m: mapped, mst protected (extent) mft record to synchronize
422 *
423 * Write the mapped, mst protected (extent) mft record @m with mft record
424 * number @mft_no to the mft mirror ($MFTMirr) of the ntfs volume @vol,
425 * bypassing the page cache and the $MFTMirr inode itself.
426 *
427 * This function is only for use at umount time when the mft mirror inode has
428 * already been disposed off. We BUG() if we are called while the mft mirror
429 * inode is still attached to the volume.
430 *
431 * On success return 0. On error return -errno.
432 *
433 * NOTE: This function is not implemented yet as I am not convinced it can
434 * actually be triggered considering the sequence of commits we do in super.c::
435 * ntfs_put_super(). But just in case we provide this place holder as the
436 * alternative would be either to BUG() or to get a NULL pointer dereference
437 * and Oops.
438 */
439static int ntfs_sync_mft_mirror_umount(ntfs_volume *vol,
440 const unsigned long mft_no, MFT_RECORD *m)
441{
442 BUG_ON(vol->mftmirr_ino);
443 ntfs_error(vol->sb, "Umount time mft mirror syncing is not "
444 "implemented yet. %s", ntfs_please_email);
445 return -EOPNOTSUPP;
446}
447
448/**
449 * ntfs_sync_mft_mirror - synchronize an mft record to the mft mirror
450 * @vol: ntfs volume on which the mft record to synchronize resides
451 * @mft_no: mft record number of mft record to synchronize
452 * @m: mapped, mst protected (extent) mft record to synchronize
453 * @sync: if true, wait for i/o completion
454 *
455 * Write the mapped, mst protected (extent) mft record @m with mft record
456 * number @mft_no to the mft mirror ($MFTMirr) of the ntfs volume @vol.
457 *
458 * On success return 0. On error return -errno and set the volume errors flag
459 * in the ntfs volume @vol.
460 *
461 * NOTE: We always perform synchronous i/o and ignore the @sync parameter.
462 *
463 * TODO: If @sync is false, want to do truly asynchronous i/o, i.e. just
464 * schedule i/o via ->writepage or do it via kntfsd or whatever.
465 */
466int ntfs_sync_mft_mirror(ntfs_volume *vol, const unsigned long mft_no,
467 MFT_RECORD *m, int sync)
468{
469 struct page *page;
470 unsigned int blocksize = vol->sb->s_blocksize;
471 int max_bhs = vol->mft_record_size / blocksize;
472 struct buffer_head *bhs[max_bhs];
473 struct buffer_head *bh, *head;
474 u8 *kmirr;
475 runlist_element *rl;
476 unsigned int block_start, block_end, m_start, m_end, page_ofs;
477 int i_bhs, nr_bhs, err = 0;
478 unsigned char blocksize_bits = vol->sb->s_blocksize_bits;
479
480 ntfs_debug("Entering for inode 0x%lx.", mft_no);
481 BUG_ON(!max_bhs);
482 if (unlikely(!vol->mftmirr_ino)) {
483 /* This could happen during umount... */
484 err = ntfs_sync_mft_mirror_umount(vol, mft_no, m);
485 if (likely(!err))
486 return err;
487 goto err_out;
488 }
489 /* Get the page containing the mirror copy of the mft record @m. */
490 page = ntfs_map_page(vol->mftmirr_ino->i_mapping, mft_no >>
491 (PAGE_SHIFT - vol->mft_record_size_bits));
492 if (IS_ERR(page)) {
493 ntfs_error(vol->sb, "Failed to map mft mirror page.");
494 err = PTR_ERR(page);
495 goto err_out;
496 }
497 lock_page(page);
498 BUG_ON(!PageUptodate(page));
499 ClearPageUptodate(page);
500 /* Offset of the mft mirror record inside the page. */
501 page_ofs = (mft_no << vol->mft_record_size_bits) & ~PAGE_MASK;
502 /* The address in the page of the mirror copy of the mft record @m. */
503 kmirr = page_address(page) + page_ofs;
504 /* Copy the mst protected mft record to the mirror. */
505 memcpy(kmirr, m, vol->mft_record_size);
506 /* Create uptodate buffers if not present. */
507 if (unlikely(!page_has_buffers(page))) {
508 struct buffer_head *tail;
509
510 bh = head = alloc_page_buffers(page, blocksize, true);
511 do {
512 set_buffer_uptodate(bh);
513 tail = bh;
514 bh = bh->b_this_page;
515 } while (bh);
516 tail->b_this_page = head;
517 attach_page_buffers(page, head);
518 }
519 bh = head = page_buffers(page);
520 BUG_ON(!bh);
521 rl = NULL;
522 nr_bhs = 0;
523 block_start = 0;
524 m_start = kmirr - (u8*)page_address(page);
525 m_end = m_start + vol->mft_record_size;
526 do {
527 block_end = block_start + blocksize;
528 /* If the buffer is outside the mft record, skip it. */
529 if (block_end <= m_start)
530 continue;
531 if (unlikely(block_start >= m_end))
532 break;
533 /* Need to map the buffer if it is not mapped already. */
534 if (unlikely(!buffer_mapped(bh))) {
535 VCN vcn;
536 LCN lcn;
537 unsigned int vcn_ofs;
538
539 bh->b_bdev = vol->sb->s_bdev;
540 /* Obtain the vcn and offset of the current block. */
541 vcn = ((VCN)mft_no << vol->mft_record_size_bits) +
542 (block_start - m_start);
543 vcn_ofs = vcn & vol->cluster_size_mask;
544 vcn >>= vol->cluster_size_bits;
545 if (!rl) {
546 down_read(&NTFS_I(vol->mftmirr_ino)->
547 runlist.lock);
548 rl = NTFS_I(vol->mftmirr_ino)->runlist.rl;
549 /*
550 * $MFTMirr always has the whole of its runlist
551 * in memory.
552 */
553 BUG_ON(!rl);
554 }
555 /* Seek to element containing target vcn. */
556 while (rl->length && rl[1].vcn <= vcn)
557 rl++;
558 lcn = ntfs_rl_vcn_to_lcn(rl, vcn);
559 /* For $MFTMirr, only lcn >= 0 is a successful remap. */
560 if (likely(lcn >= 0)) {
561 /* Setup buffer head to correct block. */
562 bh->b_blocknr = ((lcn <<
563 vol->cluster_size_bits) +
564 vcn_ofs) >> blocksize_bits;
565 set_buffer_mapped(bh);
566 } else {
567 bh->b_blocknr = -1;
568 ntfs_error(vol->sb, "Cannot write mft mirror "
569 "record 0x%lx because its "
570 "location on disk could not "
571 "be determined (error code "
572 "%lli).", mft_no,
573 (long long)lcn);
574 err = -EIO;
575 }
576 }
577 BUG_ON(!buffer_uptodate(bh));
578 BUG_ON(!nr_bhs && (m_start != block_start));
579 BUG_ON(nr_bhs >= max_bhs);
580 bhs[nr_bhs++] = bh;
581 BUG_ON((nr_bhs >= max_bhs) && (m_end != block_end));
582 } while (block_start = block_end, (bh = bh->b_this_page) != head);
583 if (unlikely(rl))
584 up_read(&NTFS_I(vol->mftmirr_ino)->runlist.lock);
585 if (likely(!err)) {
586 /* Lock buffers and start synchronous write i/o on them. */
587 for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) {
588 struct buffer_head *tbh = bhs[i_bhs];
589
590 if (!trylock_buffer(tbh))
591 BUG();
592 BUG_ON(!buffer_uptodate(tbh));
593 clear_buffer_dirty(tbh);
594 get_bh(tbh);
595 tbh->b_end_io = end_buffer_write_sync;
596 submit_bh(REQ_OP_WRITE, 0, tbh);
597 }
598 /* Wait on i/o completion of buffers. */
599 for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) {
600 struct buffer_head *tbh = bhs[i_bhs];
601
602 wait_on_buffer(tbh);
603 if (unlikely(!buffer_uptodate(tbh))) {
604 err = -EIO;
605 /*
606 * Set the buffer uptodate so the page and
607 * buffer states do not become out of sync.
608 */
609 set_buffer_uptodate(tbh);
610 }
611 }
612 } else /* if (unlikely(err)) */ {
613 /* Clean the buffers. */
614 for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++)
615 clear_buffer_dirty(bhs[i_bhs]);
616 }
617 /* Current state: all buffers are clean, unlocked, and uptodate. */
618 /* Remove the mst protection fixups again. */
619 post_write_mst_fixup((NTFS_RECORD*)kmirr);
620 flush_dcache_page(page);
621 SetPageUptodate(page);
622 unlock_page(page);
623 ntfs_unmap_page(page);
624 if (likely(!err)) {
625 ntfs_debug("Done.");
626 } else {
627 ntfs_error(vol->sb, "I/O error while writing mft mirror "
628 "record 0x%lx!", mft_no);
629err_out:
630 ntfs_error(vol->sb, "Failed to synchronize $MFTMirr (error "
631 "code %i). Volume will be left marked dirty "
632 "on umount. Run ntfsfix on the partition "
633 "after umounting to correct this.", -err);
634 NVolSetErrors(vol);
635 }
636 return err;
637}
638
639/**
640 * write_mft_record_nolock - write out a mapped (extent) mft record
641 * @ni: ntfs inode describing the mapped (extent) mft record
642 * @m: mapped (extent) mft record to write
643 * @sync: if true, wait for i/o completion
644 *
645 * Write the mapped (extent) mft record @m described by the (regular or extent)
646 * ntfs inode @ni to backing store. If the mft record @m has a counterpart in
647 * the mft mirror, that is also updated.
648 *
649 * We only write the mft record if the ntfs inode @ni is dirty and the first
650 * buffer belonging to its mft record is dirty, too. We ignore the dirty state
651 * of subsequent buffers because we could have raced with
652 * fs/ntfs/aops.c::mark_ntfs_record_dirty().
653 *
654 * On success, clean the mft record and return 0. On error, leave the mft
655 * record dirty and return -errno.
656 *
657 * NOTE: We always perform synchronous i/o and ignore the @sync parameter.
658 * However, if the mft record has a counterpart in the mft mirror and @sync is
659 * true, we write the mft record, wait for i/o completion, and only then write
660 * the mft mirror copy. This ensures that if the system crashes either the mft
661 * or the mft mirror will contain a self-consistent mft record @m. If @sync is
662 * false on the other hand, we start i/o on both and then wait for completion
663 * on them. This provides a speedup but no longer guarantees that you will end
664 * up with a self-consistent mft record in the case of a crash but if you asked
665 * for asynchronous writing you probably do not care about that anyway.
666 *
667 * TODO: If @sync is false, want to do truly asynchronous i/o, i.e. just
668 * schedule i/o via ->writepage or do it via kntfsd or whatever.
669 */
670int write_mft_record_nolock(ntfs_inode *ni, MFT_RECORD *m, int sync)
671{
672 ntfs_volume *vol = ni->vol;
673 struct page *page = ni->page;
674 unsigned int blocksize = vol->sb->s_blocksize;
675 unsigned char blocksize_bits = vol->sb->s_blocksize_bits;
676 int max_bhs = vol->mft_record_size / blocksize;
677 struct buffer_head *bhs[max_bhs];
678 struct buffer_head *bh, *head;
679 runlist_element *rl;
680 unsigned int block_start, block_end, m_start, m_end;
681 int i_bhs, nr_bhs, err = 0;
682
683 ntfs_debug("Entering for inode 0x%lx.", ni->mft_no);
684 BUG_ON(NInoAttr(ni));
685 BUG_ON(!max_bhs);
686 BUG_ON(!PageLocked(page));
687 /*
688 * If the ntfs_inode is clean no need to do anything. If it is dirty,
689 * mark it as clean now so that it can be redirtied later on if needed.
690 * There is no danger of races since the caller is holding the locks
691 * for the mft record @m and the page it is in.
692 */
693 if (!NInoTestClearDirty(ni))
694 goto done;
695 bh = head = page_buffers(page);
696 BUG_ON(!bh);
697 rl = NULL;
698 nr_bhs = 0;
699 block_start = 0;
700 m_start = ni->page_ofs;
701 m_end = m_start + vol->mft_record_size;
702 do {
703 block_end = block_start + blocksize;
704 /* If the buffer is outside the mft record, skip it. */
705 if (block_end <= m_start)
706 continue;
707 if (unlikely(block_start >= m_end))
708 break;
709 /*
710 * If this block is not the first one in the record, we ignore
711 * the buffer's dirty state because we could have raced with a
712 * parallel mark_ntfs_record_dirty().
713 */
714 if (block_start == m_start) {
715 /* This block is the first one in the record. */
716 if (!buffer_dirty(bh)) {
717 BUG_ON(nr_bhs);
718 /* Clean records are not written out. */
719 break;
720 }
721 }
722 /* Need to map the buffer if it is not mapped already. */
723 if (unlikely(!buffer_mapped(bh))) {
724 VCN vcn;
725 LCN lcn;
726 unsigned int vcn_ofs;
727
728 bh->b_bdev = vol->sb->s_bdev;
729 /* Obtain the vcn and offset of the current block. */
730 vcn = ((VCN)ni->mft_no << vol->mft_record_size_bits) +
731 (block_start - m_start);
732 vcn_ofs = vcn & vol->cluster_size_mask;
733 vcn >>= vol->cluster_size_bits;
734 if (!rl) {
735 down_read(&NTFS_I(vol->mft_ino)->runlist.lock);
736 rl = NTFS_I(vol->mft_ino)->runlist.rl;
737 BUG_ON(!rl);
738 }
739 /* Seek to element containing target vcn. */
740 while (rl->length && rl[1].vcn <= vcn)
741 rl++;
742 lcn = ntfs_rl_vcn_to_lcn(rl, vcn);
743 /* For $MFT, only lcn >= 0 is a successful remap. */
744 if (likely(lcn >= 0)) {
745 /* Setup buffer head to correct block. */
746 bh->b_blocknr = ((lcn <<
747 vol->cluster_size_bits) +
748 vcn_ofs) >> blocksize_bits;
749 set_buffer_mapped(bh);
750 } else {
751 bh->b_blocknr = -1;
752 ntfs_error(vol->sb, "Cannot write mft record "
753 "0x%lx because its location "
754 "on disk could not be "
755 "determined (error code %lli).",
756 ni->mft_no, (long long)lcn);
757 err = -EIO;
758 }
759 }
760 BUG_ON(!buffer_uptodate(bh));
761 BUG_ON(!nr_bhs && (m_start != block_start));
762 BUG_ON(nr_bhs >= max_bhs);
763 bhs[nr_bhs++] = bh;
764 BUG_ON((nr_bhs >= max_bhs) && (m_end != block_end));
765 } while (block_start = block_end, (bh = bh->b_this_page) != head);
766 if (unlikely(rl))
767 up_read(&NTFS_I(vol->mft_ino)->runlist.lock);
768 if (!nr_bhs)
769 goto done;
770 if (unlikely(err))
771 goto cleanup_out;
772 /* Apply the mst protection fixups. */
773 err = pre_write_mst_fixup((NTFS_RECORD*)m, vol->mft_record_size);
774 if (err) {
775 ntfs_error(vol->sb, "Failed to apply mst fixups!");
776 goto cleanup_out;
777 }
778 flush_dcache_mft_record_page(ni);
779 /* Lock buffers and start synchronous write i/o on them. */
780 for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) {
781 struct buffer_head *tbh = bhs[i_bhs];
782
783 if (!trylock_buffer(tbh))
784 BUG();
785 BUG_ON(!buffer_uptodate(tbh));
786 clear_buffer_dirty(tbh);
787 get_bh(tbh);
788 tbh->b_end_io = end_buffer_write_sync;
789 submit_bh(REQ_OP_WRITE, 0, tbh);
790 }
791 /* Synchronize the mft mirror now if not @sync. */
792 if (!sync && ni->mft_no < vol->mftmirr_size)
793 ntfs_sync_mft_mirror(vol, ni->mft_no, m, sync);
794 /* Wait on i/o completion of buffers. */
795 for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) {
796 struct buffer_head *tbh = bhs[i_bhs];
797
798 wait_on_buffer(tbh);
799 if (unlikely(!buffer_uptodate(tbh))) {
800 err = -EIO;
801 /*
802 * Set the buffer uptodate so the page and buffer
803 * states do not become out of sync.
804 */
805 if (PageUptodate(page))
806 set_buffer_uptodate(tbh);
807 }
808 }
809 /* If @sync, now synchronize the mft mirror. */
810 if (sync && ni->mft_no < vol->mftmirr_size)
811 ntfs_sync_mft_mirror(vol, ni->mft_no, m, sync);
812 /* Remove the mst protection fixups again. */
813 post_write_mst_fixup((NTFS_RECORD*)m);
814 flush_dcache_mft_record_page(ni);
815 if (unlikely(err)) {
816 /* I/O error during writing. This is really bad! */
817 ntfs_error(vol->sb, "I/O error while writing mft record "
818 "0x%lx! Marking base inode as bad. You "
819 "should unmount the volume and run chkdsk.",
820 ni->mft_no);
821 goto err_out;
822 }
823done:
824 ntfs_debug("Done.");
825 return 0;
826cleanup_out:
827 /* Clean the buffers. */
828 for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++)
829 clear_buffer_dirty(bhs[i_bhs]);
830err_out:
831 /*
832 * Current state: all buffers are clean, unlocked, and uptodate.
833 * The caller should mark the base inode as bad so that no more i/o
834 * happens. ->clear_inode() will still be invoked so all extent inodes
835 * and other allocated memory will be freed.
836 */
837 if (err == -ENOMEM) {
838 ntfs_error(vol->sb, "Not enough memory to write mft record. "
839 "Redirtying so the write is retried later.");
840 mark_mft_record_dirty(ni);
841 err = 0;
842 } else
843 NVolSetErrors(vol);
844 return err;
845}
846
847/**
848 * ntfs_may_write_mft_record - check if an mft record may be written out
849 * @vol: [IN] ntfs volume on which the mft record to check resides
850 * @mft_no: [IN] mft record number of the mft record to check
851 * @m: [IN] mapped mft record to check
852 * @locked_ni: [OUT] caller has to unlock this ntfs inode if one is returned
853 *
854 * Check if the mapped (base or extent) mft record @m with mft record number
855 * @mft_no belonging to the ntfs volume @vol may be written out. If necessary
856 * and possible the ntfs inode of the mft record is locked and the base vfs
857 * inode is pinned. The locked ntfs inode is then returned in @locked_ni. The
858 * caller is responsible for unlocking the ntfs inode and unpinning the base
859 * vfs inode.
860 *
861 * Return 'true' if the mft record may be written out and 'false' if not.
862 *
863 * The caller has locked the page and cleared the uptodate flag on it which
864 * means that we can safely write out any dirty mft records that do not have
865 * their inodes in icache as determined by ilookup5() as anyone
866 * opening/creating such an inode would block when attempting to map the mft
867 * record in read_cache_page() until we are finished with the write out.
868 *
869 * Here is a description of the tests we perform:
870 *
871 * If the inode is found in icache we know the mft record must be a base mft
872 * record. If it is dirty, we do not write it and return 'false' as the vfs
873 * inode write paths will result in the access times being updated which would
874 * cause the base mft record to be redirtied and written out again. (We know
875 * the access time update will modify the base mft record because Windows
876 * chkdsk complains if the standard information attribute is not in the base
877 * mft record.)
878 *
879 * If the inode is in icache and not dirty, we attempt to lock the mft record
880 * and if we find the lock was already taken, it is not safe to write the mft
881 * record and we return 'false'.
882 *
883 * If we manage to obtain the lock we have exclusive access to the mft record,
884 * which also allows us safe writeout of the mft record. We then set
885 * @locked_ni to the locked ntfs inode and return 'true'.
886 *
887 * Note we cannot just lock the mft record and sleep while waiting for the lock
888 * because this would deadlock due to lock reversal (normally the mft record is
889 * locked before the page is locked but we already have the page locked here
890 * when we try to lock the mft record).
891 *
892 * If the inode is not in icache we need to perform further checks.
893 *
894 * If the mft record is not a FILE record or it is a base mft record, we can
895 * safely write it and return 'true'.
896 *
897 * We now know the mft record is an extent mft record. We check if the inode
898 * corresponding to its base mft record is in icache and obtain a reference to
899 * it if it is. If it is not, we can safely write it and return 'true'.
900 *
901 * We now have the base inode for the extent mft record. We check if it has an
902 * ntfs inode for the extent mft record attached and if not it is safe to write
903 * the extent mft record and we return 'true'.
904 *
905 * The ntfs inode for the extent mft record is attached to the base inode so we
906 * attempt to lock the extent mft record and if we find the lock was already
907 * taken, it is not safe to write the extent mft record and we return 'false'.
908 *
909 * If we manage to obtain the lock we have exclusive access to the extent mft
910 * record, which also allows us safe writeout of the extent mft record. We
911 * set the ntfs inode of the extent mft record clean and then set @locked_ni to
912 * the now locked ntfs inode and return 'true'.
913 *
914 * Note, the reason for actually writing dirty mft records here and not just
915 * relying on the vfs inode dirty code paths is that we can have mft records
916 * modified without them ever having actual inodes in memory. Also we can have
917 * dirty mft records with clean ntfs inodes in memory. None of the described
918 * cases would result in the dirty mft records being written out if we only
919 * relied on the vfs inode dirty code paths. And these cases can really occur
920 * during allocation of new mft records and in particular when the
921 * initialized_size of the $MFT/$DATA attribute is extended and the new space
922 * is initialized using ntfs_mft_record_format(). The clean inode can then
923 * appear if the mft record is reused for a new inode before it got written
924 * out.
925 */
926bool ntfs_may_write_mft_record(ntfs_volume *vol, const unsigned long mft_no,
927 const MFT_RECORD *m, ntfs_inode **locked_ni)
928{
929 struct super_block *sb = vol->sb;
930 struct inode *mft_vi = vol->mft_ino;
931 struct inode *vi;
932 ntfs_inode *ni, *eni, **extent_nis;
933 int i;
934 ntfs_attr na;
935
936 ntfs_debug("Entering for inode 0x%lx.", mft_no);
937 /*
938 * Normally we do not return a locked inode so set @locked_ni to NULL.
939 */
940 BUG_ON(!locked_ni);
941 *locked_ni = NULL;
942 /*
943 * Check if the inode corresponding to this mft record is in the VFS
944 * inode cache and obtain a reference to it if it is.
945 */
946 ntfs_debug("Looking for inode 0x%lx in icache.", mft_no);
947 na.mft_no = mft_no;
948 na.name = NULL;
949 na.name_len = 0;
950 na.type = AT_UNUSED;
951 /*
952 * Optimize inode 0, i.e. $MFT itself, since we have it in memory and
953 * we get here for it rather often.
954 */
955 if (!mft_no) {
956 /* Balance the below iput(). */
957 vi = igrab(mft_vi);
958 BUG_ON(vi != mft_vi);
959 } else {
960 /*
961 * Have to use ilookup5_nowait() since ilookup5() waits for the
962 * inode lock which causes ntfs to deadlock when a concurrent
963 * inode write via the inode dirty code paths and the page
964 * dirty code path of the inode dirty code path when writing
965 * $MFT occurs.
966 */
967 vi = ilookup5_nowait(sb, mft_no, (test_t)ntfs_test_inode, &na);
968 }
969 if (vi) {
970 ntfs_debug("Base inode 0x%lx is in icache.", mft_no);
971 /* The inode is in icache. */
972 ni = NTFS_I(vi);
973 /* Take a reference to the ntfs inode. */
974 atomic_inc(&ni->count);
975 /* If the inode is dirty, do not write this record. */
976 if (NInoDirty(ni)) {
977 ntfs_debug("Inode 0x%lx is dirty, do not write it.",
978 mft_no);
979 atomic_dec(&ni->count);
980 iput(vi);
981 return false;
982 }
983 ntfs_debug("Inode 0x%lx is not dirty.", mft_no);
984 /* The inode is not dirty, try to take the mft record lock. */
985 if (unlikely(!mutex_trylock(&ni->mrec_lock))) {
986 ntfs_debug("Mft record 0x%lx is already locked, do "
987 "not write it.", mft_no);
988 atomic_dec(&ni->count);
989 iput(vi);
990 return false;
991 }
992 ntfs_debug("Managed to lock mft record 0x%lx, write it.",
993 mft_no);
994 /*
995 * The write has to occur while we hold the mft record lock so
996 * return the locked ntfs inode.
997 */
998 *locked_ni = ni;
999 return true;
1000 }
1001 ntfs_debug("Inode 0x%lx is not in icache.", mft_no);
1002 /* The inode is not in icache. */
1003 /* Write the record if it is not a mft record (type "FILE"). */
1004 if (!ntfs_is_mft_record(m->magic)) {
1005 ntfs_debug("Mft record 0x%lx is not a FILE record, write it.",
1006 mft_no);
1007 return true;
1008 }
1009 /* Write the mft record if it is a base inode. */
1010 if (!m->base_mft_record) {
1011 ntfs_debug("Mft record 0x%lx is a base record, write it.",
1012 mft_no);
1013 return true;
1014 }
1015 /*
1016 * This is an extent mft record. Check if the inode corresponding to
1017 * its base mft record is in icache and obtain a reference to it if it
1018 * is.
1019 */
1020 na.mft_no = MREF_LE(m->base_mft_record);
1021 ntfs_debug("Mft record 0x%lx is an extent record. Looking for base "
1022 "inode 0x%lx in icache.", mft_no, na.mft_no);
1023 if (!na.mft_no) {
1024 /* Balance the below iput(). */
1025 vi = igrab(mft_vi);
1026 BUG_ON(vi != mft_vi);
1027 } else
1028 vi = ilookup5_nowait(sb, na.mft_no, (test_t)ntfs_test_inode,
1029 &na);
1030 if (!vi) {
1031 /*
1032 * The base inode is not in icache, write this extent mft
1033 * record.
1034 */
1035 ntfs_debug("Base inode 0x%lx is not in icache, write the "
1036 "extent record.", na.mft_no);
1037 return true;
1038 }
1039 ntfs_debug("Base inode 0x%lx is in icache.", na.mft_no);
1040 /*
1041 * The base inode is in icache. Check if it has the extent inode
1042 * corresponding to this extent mft record attached.
1043 */
1044 ni = NTFS_I(vi);
1045 mutex_lock(&ni->extent_lock);
1046 if (ni->nr_extents <= 0) {
1047 /*
1048 * The base inode has no attached extent inodes, write this
1049 * extent mft record.
1050 */
1051 mutex_unlock(&ni->extent_lock);
1052 iput(vi);
1053 ntfs_debug("Base inode 0x%lx has no attached extent inodes, "
1054 "write the extent record.", na.mft_no);
1055 return true;
1056 }
1057 /* Iterate over the attached extent inodes. */
1058 extent_nis = ni->ext.extent_ntfs_inos;
1059 for (eni = NULL, i = 0; i < ni->nr_extents; ++i) {
1060 if (mft_no == extent_nis[i]->mft_no) {
1061 /*
1062 * Found the extent inode corresponding to this extent
1063 * mft record.
1064 */
1065 eni = extent_nis[i];
1066 break;
1067 }
1068 }
1069 /*
1070 * If the extent inode was not attached to the base inode, write this
1071 * extent mft record.
1072 */
1073 if (!eni) {
1074 mutex_unlock(&ni->extent_lock);
1075 iput(vi);
1076 ntfs_debug("Extent inode 0x%lx is not attached to its base "
1077 "inode 0x%lx, write the extent record.",
1078 mft_no, na.mft_no);
1079 return true;
1080 }
1081 ntfs_debug("Extent inode 0x%lx is attached to its base inode 0x%lx.",
1082 mft_no, na.mft_no);
1083 /* Take a reference to the extent ntfs inode. */
1084 atomic_inc(&eni->count);
1085 mutex_unlock(&ni->extent_lock);
1086 /*
1087 * Found the extent inode coresponding to this extent mft record.
1088 * Try to take the mft record lock.
1089 */
1090 if (unlikely(!mutex_trylock(&eni->mrec_lock))) {
1091 atomic_dec(&eni->count);
1092 iput(vi);
1093 ntfs_debug("Extent mft record 0x%lx is already locked, do "
1094 "not write it.", mft_no);
1095 return false;
1096 }
1097 ntfs_debug("Managed to lock extent mft record 0x%lx, write it.",
1098 mft_no);
1099 if (NInoTestClearDirty(eni))
1100 ntfs_debug("Extent inode 0x%lx is dirty, marking it clean.",
1101 mft_no);
1102 /*
1103 * The write has to occur while we hold the mft record lock so return
1104 * the locked extent ntfs inode.
1105 */
1106 *locked_ni = eni;
1107 return true;
1108}
1109
1110static const char *es = " Leaving inconsistent metadata. Unmount and run "
1111 "chkdsk.";
1112
1113/**
1114 * ntfs_mft_bitmap_find_and_alloc_free_rec_nolock - see name
1115 * @vol: volume on which to search for a free mft record
1116 * @base_ni: open base inode if allocating an extent mft record or NULL
1117 *
1118 * Search for a free mft record in the mft bitmap attribute on the ntfs volume
1119 * @vol.
1120 *
1121 * If @base_ni is NULL start the search at the default allocator position.
1122 *
1123 * If @base_ni is not NULL start the search at the mft record after the base
1124 * mft record @base_ni.
1125 *
1126 * Return the free mft record on success and -errno on error. An error code of
1127 * -ENOSPC means that there are no free mft records in the currently
1128 * initialized mft bitmap.
1129 *
1130 * Locking: Caller must hold vol->mftbmp_lock for writing.
1131 */
1132static int ntfs_mft_bitmap_find_and_alloc_free_rec_nolock(ntfs_volume *vol,
1133 ntfs_inode *base_ni)
1134{
1135 s64 pass_end, ll, data_pos, pass_start, ofs, bit;
1136 unsigned long flags;
1137 struct address_space *mftbmp_mapping;
1138 u8 *buf, *byte;
1139 struct page *page;
1140 unsigned int page_ofs, size;
1141 u8 pass, b;
1142
1143 ntfs_debug("Searching for free mft record in the currently "
1144 "initialized mft bitmap.");
1145 mftbmp_mapping = vol->mftbmp_ino->i_mapping;
1146 /*
1147 * Set the end of the pass making sure we do not overflow the mft
1148 * bitmap.
1149 */
1150 read_lock_irqsave(&NTFS_I(vol->mft_ino)->size_lock, flags);
1151 pass_end = NTFS_I(vol->mft_ino)->allocated_size >>
1152 vol->mft_record_size_bits;
1153 read_unlock_irqrestore(&NTFS_I(vol->mft_ino)->size_lock, flags);
1154 read_lock_irqsave(&NTFS_I(vol->mftbmp_ino)->size_lock, flags);
1155 ll = NTFS_I(vol->mftbmp_ino)->initialized_size << 3;
1156 read_unlock_irqrestore(&NTFS_I(vol->mftbmp_ino)->size_lock, flags);
1157 if (pass_end > ll)
1158 pass_end = ll;
1159 pass = 1;
1160 if (!base_ni)
1161 data_pos = vol->mft_data_pos;
1162 else
1163 data_pos = base_ni->mft_no + 1;
1164 if (data_pos < 24)
1165 data_pos = 24;
1166 if (data_pos >= pass_end) {
1167 data_pos = 24;
1168 pass = 2;
1169 /* This happens on a freshly formatted volume. */
1170 if (data_pos >= pass_end)
1171 return -ENOSPC;
1172 }
1173 pass_start = data_pos;
1174 ntfs_debug("Starting bitmap search: pass %u, pass_start 0x%llx, "
1175 "pass_end 0x%llx, data_pos 0x%llx.", pass,
1176 (long long)pass_start, (long long)pass_end,
1177 (long long)data_pos);
1178 /* Loop until a free mft record is found. */
1179 for (; pass <= 2;) {
1180 /* Cap size to pass_end. */
1181 ofs = data_pos >> 3;
1182 page_ofs = ofs & ~PAGE_MASK;
1183 size = PAGE_SIZE - page_ofs;
1184 ll = ((pass_end + 7) >> 3) - ofs;
1185 if (size > ll)
1186 size = ll;
1187 size <<= 3;
1188 /*
1189 * If we are still within the active pass, search the next page
1190 * for a zero bit.
1191 */
1192 if (size) {
1193 page = ntfs_map_page(mftbmp_mapping,
1194 ofs >> PAGE_SHIFT);
1195 if (IS_ERR(page)) {
1196 ntfs_error(vol->sb, "Failed to read mft "
1197 "bitmap, aborting.");
1198 return PTR_ERR(page);
1199 }
1200 buf = (u8*)page_address(page) + page_ofs;
1201 bit = data_pos & 7;
1202 data_pos &= ~7ull;
1203 ntfs_debug("Before inner for loop: size 0x%x, "
1204 "data_pos 0x%llx, bit 0x%llx", size,
1205 (long long)data_pos, (long long)bit);
1206 for (; bit < size && data_pos + bit < pass_end;
1207 bit &= ~7ull, bit += 8) {
1208 byte = buf + (bit >> 3);
1209 if (*byte == 0xff)
1210 continue;
1211 b = ffz((unsigned long)*byte);
1212 if (b < 8 && b >= (bit & 7)) {
1213 ll = data_pos + (bit & ~7ull) + b;
1214 if (unlikely(ll > (1ll << 32))) {
1215 ntfs_unmap_page(page);
1216 return -ENOSPC;
1217 }
1218 *byte |= 1 << b;
1219 flush_dcache_page(page);
1220 set_page_dirty(page);
1221 ntfs_unmap_page(page);
1222 ntfs_debug("Done. (Found and "
1223 "allocated mft record "
1224 "0x%llx.)",
1225 (long long)ll);
1226 return ll;
1227 }
1228 }
1229 ntfs_debug("After inner for loop: size 0x%x, "
1230 "data_pos 0x%llx, bit 0x%llx", size,
1231 (long long)data_pos, (long long)bit);
1232 data_pos += size;
1233 ntfs_unmap_page(page);
1234 /*
1235 * If the end of the pass has not been reached yet,
1236 * continue searching the mft bitmap for a zero bit.
1237 */
1238 if (data_pos < pass_end)
1239 continue;
1240 }
1241 /* Do the next pass. */
1242 if (++pass == 2) {
1243 /*
1244 * Starting the second pass, in which we scan the first
1245 * part of the zone which we omitted earlier.
1246 */
1247 pass_end = pass_start;
1248 data_pos = pass_start = 24;
1249 ntfs_debug("pass %i, pass_start 0x%llx, pass_end "
1250 "0x%llx.", pass, (long long)pass_start,
1251 (long long)pass_end);
1252 if (data_pos >= pass_end)
1253 break;
1254 }
1255 }
1256 /* No free mft records in currently initialized mft bitmap. */
1257 ntfs_debug("Done. (No free mft records left in currently initialized "
1258 "mft bitmap.)");
1259 return -ENOSPC;
1260}
1261
1262/**
1263 * ntfs_mft_bitmap_extend_allocation_nolock - extend mft bitmap by a cluster
1264 * @vol: volume on which to extend the mft bitmap attribute
1265 *
1266 * Extend the mft bitmap attribute on the ntfs volume @vol by one cluster.
1267 *
1268 * Note: Only changes allocated_size, i.e. does not touch initialized_size or
1269 * data_size.
1270 *
1271 * Return 0 on success and -errno on error.
1272 *
1273 * Locking: - Caller must hold vol->mftbmp_lock for writing.
1274 * - This function takes NTFS_I(vol->mftbmp_ino)->runlist.lock for
1275 * writing and releases it before returning.
1276 * - This function takes vol->lcnbmp_lock for writing and releases it
1277 * before returning.
1278 */
1279static int ntfs_mft_bitmap_extend_allocation_nolock(ntfs_volume *vol)
1280{
1281 LCN lcn;
1282 s64 ll;
1283 unsigned long flags;
1284 struct page *page;
1285 ntfs_inode *mft_ni, *mftbmp_ni;
1286 runlist_element *rl, *rl2 = NULL;
1287 ntfs_attr_search_ctx *ctx = NULL;
1288 MFT_RECORD *mrec;
1289 ATTR_RECORD *a = NULL;
1290 int ret, mp_size;
1291 u32 old_alen = 0;
1292 u8 *b, tb;
1293 struct {
1294 u8 added_cluster:1;
1295 u8 added_run:1;
1296 u8 mp_rebuilt:1;
1297 } status = { 0, 0, 0 };
1298
1299 ntfs_debug("Extending mft bitmap allocation.");
1300 mft_ni = NTFS_I(vol->mft_ino);
1301 mftbmp_ni = NTFS_I(vol->mftbmp_ino);
1302 /*
1303 * Determine the last lcn of the mft bitmap. The allocated size of the
1304 * mft bitmap cannot be zero so we are ok to do this.
1305 */
1306 down_write(&mftbmp_ni->runlist.lock);
1307 read_lock_irqsave(&mftbmp_ni->size_lock, flags);
1308 ll = mftbmp_ni->allocated_size;
1309 read_unlock_irqrestore(&mftbmp_ni->size_lock, flags);
1310 rl = ntfs_attr_find_vcn_nolock(mftbmp_ni,
1311 (ll - 1) >> vol->cluster_size_bits, NULL);
1312 if (unlikely(IS_ERR(rl) || !rl->length || rl->lcn < 0)) {
1313 up_write(&mftbmp_ni->runlist.lock);
1314 ntfs_error(vol->sb, "Failed to determine last allocated "
1315 "cluster of mft bitmap attribute.");
1316 if (!IS_ERR(rl))
1317 ret = -EIO;
1318 else
1319 ret = PTR_ERR(rl);
1320 return ret;
1321 }
1322 lcn = rl->lcn + rl->length;
1323 ntfs_debug("Last lcn of mft bitmap attribute is 0x%llx.",
1324 (long long)lcn);
1325 /*
1326 * Attempt to get the cluster following the last allocated cluster by
1327 * hand as it may be in the MFT zone so the allocator would not give it
1328 * to us.
1329 */
1330 ll = lcn >> 3;
1331 page = ntfs_map_page(vol->lcnbmp_ino->i_mapping,
1332 ll >> PAGE_SHIFT);
1333 if (IS_ERR(page)) {
1334 up_write(&mftbmp_ni->runlist.lock);
1335 ntfs_error(vol->sb, "Failed to read from lcn bitmap.");
1336 return PTR_ERR(page);
1337 }
1338 b = (u8*)page_address(page) + (ll & ~PAGE_MASK);
1339 tb = 1 << (lcn & 7ull);
1340 down_write(&vol->lcnbmp_lock);
1341 if (*b != 0xff && !(*b & tb)) {
1342 /* Next cluster is free, allocate it. */
1343 *b |= tb;
1344 flush_dcache_page(page);
1345 set_page_dirty(page);
1346 up_write(&vol->lcnbmp_lock);
1347 ntfs_unmap_page(page);
1348 /* Update the mft bitmap runlist. */
1349 rl->length++;
1350 rl[1].vcn++;
1351 status.added_cluster = 1;
1352 ntfs_debug("Appending one cluster to mft bitmap.");
1353 } else {
1354 up_write(&vol->lcnbmp_lock);
1355 ntfs_unmap_page(page);
1356 /* Allocate a cluster from the DATA_ZONE. */
1357 rl2 = ntfs_cluster_alloc(vol, rl[1].vcn, 1, lcn, DATA_ZONE,
1358 true);
1359 if (IS_ERR(rl2)) {
1360 up_write(&mftbmp_ni->runlist.lock);
1361 ntfs_error(vol->sb, "Failed to allocate a cluster for "
1362 "the mft bitmap.");
1363 return PTR_ERR(rl2);
1364 }
1365 rl = ntfs_runlists_merge(mftbmp_ni->runlist.rl, rl2);
1366 if (IS_ERR(rl)) {
1367 up_write(&mftbmp_ni->runlist.lock);
1368 ntfs_error(vol->sb, "Failed to merge runlists for mft "
1369 "bitmap.");
1370 if (ntfs_cluster_free_from_rl(vol, rl2)) {
1371 ntfs_error(vol->sb, "Failed to deallocate "
1372 "allocated cluster.%s", es);
1373 NVolSetErrors(vol);
1374 }
1375 ntfs_free(rl2);
1376 return PTR_ERR(rl);
1377 }
1378 mftbmp_ni->runlist.rl = rl;
1379 status.added_run = 1;
1380 ntfs_debug("Adding one run to mft bitmap.");
1381 /* Find the last run in the new runlist. */
1382 for (; rl[1].length; rl++)
1383 ;
1384 }
1385 /*
1386 * Update the attribute record as well. Note: @rl is the last
1387 * (non-terminator) runlist element of mft bitmap.
1388 */
1389 mrec = map_mft_record(mft_ni);
1390 if (IS_ERR(mrec)) {
1391 ntfs_error(vol->sb, "Failed to map mft record.");
1392 ret = PTR_ERR(mrec);
1393 goto undo_alloc;
1394 }
1395 ctx = ntfs_attr_get_search_ctx(mft_ni, mrec);
1396 if (unlikely(!ctx)) {
1397 ntfs_error(vol->sb, "Failed to get search context.");
1398 ret = -ENOMEM;
1399 goto undo_alloc;
1400 }
1401 ret = ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name,
1402 mftbmp_ni->name_len, CASE_SENSITIVE, rl[1].vcn, NULL,
1403 0, ctx);
1404 if (unlikely(ret)) {
1405 ntfs_error(vol->sb, "Failed to find last attribute extent of "
1406 "mft bitmap attribute.");
1407 if (ret == -ENOENT)
1408 ret = -EIO;
1409 goto undo_alloc;
1410 }
1411 a = ctx->attr;
1412 ll = sle64_to_cpu(a->data.non_resident.lowest_vcn);
1413 /* Search back for the previous last allocated cluster of mft bitmap. */
1414 for (rl2 = rl; rl2 > mftbmp_ni->runlist.rl; rl2--) {
1415 if (ll >= rl2->vcn)
1416 break;
1417 }
1418 BUG_ON(ll < rl2->vcn);
1419 BUG_ON(ll >= rl2->vcn + rl2->length);
1420 /* Get the size for the new mapping pairs array for this extent. */
1421 mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, ll, -1);
1422 if (unlikely(mp_size <= 0)) {
1423 ntfs_error(vol->sb, "Get size for mapping pairs failed for "
1424 "mft bitmap attribute extent.");
1425 ret = mp_size;
1426 if (!ret)
1427 ret = -EIO;
1428 goto undo_alloc;
1429 }
1430 /* Expand the attribute record if necessary. */
1431 old_alen = le32_to_cpu(a->length);
1432 ret = ntfs_attr_record_resize(ctx->mrec, a, mp_size +
1433 le16_to_cpu(a->data.non_resident.mapping_pairs_offset));
1434 if (unlikely(ret)) {
1435 if (ret != -ENOSPC) {
1436 ntfs_error(vol->sb, "Failed to resize attribute "
1437 "record for mft bitmap attribute.");
1438 goto undo_alloc;
1439 }
1440 // TODO: Deal with this by moving this extent to a new mft
1441 // record or by starting a new extent in a new mft record or by
1442 // moving other attributes out of this mft record.
1443 // Note: It will need to be a special mft record and if none of
1444 // those are available it gets rather complicated...
1445 ntfs_error(vol->sb, "Not enough space in this mft record to "
1446 "accommodate extended mft bitmap attribute "
1447 "extent. Cannot handle this yet.");
1448 ret = -EOPNOTSUPP;
1449 goto undo_alloc;
1450 }
1451 status.mp_rebuilt = 1;
1452 /* Generate the mapping pairs array directly into the attr record. */
1453 ret = ntfs_mapping_pairs_build(vol, (u8*)a +
1454 le16_to_cpu(a->data.non_resident.mapping_pairs_offset),
1455 mp_size, rl2, ll, -1, NULL);
1456 if (unlikely(ret)) {
1457 ntfs_error(vol->sb, "Failed to build mapping pairs array for "
1458 "mft bitmap attribute.");
1459 goto undo_alloc;
1460 }
1461 /* Update the highest_vcn. */
1462 a->data.non_resident.highest_vcn = cpu_to_sle64(rl[1].vcn - 1);
1463 /*
1464 * We now have extended the mft bitmap allocated_size by one cluster.
1465 * Reflect this in the ntfs_inode structure and the attribute record.
1466 */
1467 if (a->data.non_resident.lowest_vcn) {
1468 /*
1469 * We are not in the first attribute extent, switch to it, but
1470 * first ensure the changes will make it to disk later.
1471 */
1472 flush_dcache_mft_record_page(ctx->ntfs_ino);
1473 mark_mft_record_dirty(ctx->ntfs_ino);
1474 ntfs_attr_reinit_search_ctx(ctx);
1475 ret = ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name,
1476 mftbmp_ni->name_len, CASE_SENSITIVE, 0, NULL,
1477 0, ctx);
1478 if (unlikely(ret)) {
1479 ntfs_error(vol->sb, "Failed to find first attribute "
1480 "extent of mft bitmap attribute.");
1481 goto restore_undo_alloc;
1482 }
1483 a = ctx->attr;
1484 }
1485 write_lock_irqsave(&mftbmp_ni->size_lock, flags);
1486 mftbmp_ni->allocated_size += vol->cluster_size;
1487 a->data.non_resident.allocated_size =
1488 cpu_to_sle64(mftbmp_ni->allocated_size);
1489 write_unlock_irqrestore(&mftbmp_ni->size_lock, flags);
1490 /* Ensure the changes make it to disk. */
1491 flush_dcache_mft_record_page(ctx->ntfs_ino);
1492 mark_mft_record_dirty(ctx->ntfs_ino);
1493 ntfs_attr_put_search_ctx(ctx);
1494 unmap_mft_record(mft_ni);
1495 up_write(&mftbmp_ni->runlist.lock);
1496 ntfs_debug("Done.");
1497 return 0;
1498restore_undo_alloc:
1499 ntfs_attr_reinit_search_ctx(ctx);
1500 if (ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name,
1501 mftbmp_ni->name_len, CASE_SENSITIVE, rl[1].vcn, NULL,
1502 0, ctx)) {
1503 ntfs_error(vol->sb, "Failed to find last attribute extent of "
1504 "mft bitmap attribute.%s", es);
1505 write_lock_irqsave(&mftbmp_ni->size_lock, flags);
1506 mftbmp_ni->allocated_size += vol->cluster_size;
1507 write_unlock_irqrestore(&mftbmp_ni->size_lock, flags);
1508 ntfs_attr_put_search_ctx(ctx);
1509 unmap_mft_record(mft_ni);
1510 up_write(&mftbmp_ni->runlist.lock);
1511 /*
1512 * The only thing that is now wrong is ->allocated_size of the
1513 * base attribute extent which chkdsk should be able to fix.
1514 */
1515 NVolSetErrors(vol);
1516 return ret;
1517 }
1518 a = ctx->attr;
1519 a->data.non_resident.highest_vcn = cpu_to_sle64(rl[1].vcn - 2);
1520undo_alloc:
1521 if (status.added_cluster) {
1522 /* Truncate the last run in the runlist by one cluster. */
1523 rl->length--;
1524 rl[1].vcn--;
1525 } else if (status.added_run) {
1526 lcn = rl->lcn;
1527 /* Remove the last run from the runlist. */
1528 rl->lcn = rl[1].lcn;
1529 rl->length = 0;
1530 }
1531 /* Deallocate the cluster. */
1532 down_write(&vol->lcnbmp_lock);
1533 if (ntfs_bitmap_clear_bit(vol->lcnbmp_ino, lcn)) {
1534 ntfs_error(vol->sb, "Failed to free allocated cluster.%s", es);
1535 NVolSetErrors(vol);
1536 }
1537 up_write(&vol->lcnbmp_lock);
1538 if (status.mp_rebuilt) {
1539 if (ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu(
1540 a->data.non_resident.mapping_pairs_offset),
1541 old_alen - le16_to_cpu(
1542 a->data.non_resident.mapping_pairs_offset),
1543 rl2, ll, -1, NULL)) {
1544 ntfs_error(vol->sb, "Failed to restore mapping pairs "
1545 "array.%s", es);
1546 NVolSetErrors(vol);
1547 }
1548 if (ntfs_attr_record_resize(ctx->mrec, a, old_alen)) {
1549 ntfs_error(vol->sb, "Failed to restore attribute "
1550 "record.%s", es);
1551 NVolSetErrors(vol);
1552 }
1553 flush_dcache_mft_record_page(ctx->ntfs_ino);
1554 mark_mft_record_dirty(ctx->ntfs_ino);
1555 }
1556 if (ctx)
1557 ntfs_attr_put_search_ctx(ctx);
1558 if (!IS_ERR(mrec))
1559 unmap_mft_record(mft_ni);
1560 up_write(&mftbmp_ni->runlist.lock);
1561 return ret;
1562}
1563
1564/**
1565 * ntfs_mft_bitmap_extend_initialized_nolock - extend mftbmp initialized data
1566 * @vol: volume on which to extend the mft bitmap attribute
1567 *
1568 * Extend the initialized portion of the mft bitmap attribute on the ntfs
1569 * volume @vol by 8 bytes.
1570 *
1571 * Note: Only changes initialized_size and data_size, i.e. requires that
1572 * allocated_size is big enough to fit the new initialized_size.
1573 *
1574 * Return 0 on success and -error on error.
1575 *
1576 * Locking: Caller must hold vol->mftbmp_lock for writing.
1577 */
1578static int ntfs_mft_bitmap_extend_initialized_nolock(ntfs_volume *vol)
1579{
1580 s64 old_data_size, old_initialized_size;
1581 unsigned long flags;
1582 struct inode *mftbmp_vi;
1583 ntfs_inode *mft_ni, *mftbmp_ni;
1584 ntfs_attr_search_ctx *ctx;
1585 MFT_RECORD *mrec;
1586 ATTR_RECORD *a;
1587 int ret;
1588
1589 ntfs_debug("Extending mft bitmap initiailized (and data) size.");
1590 mft_ni = NTFS_I(vol->mft_ino);
1591 mftbmp_vi = vol->mftbmp_ino;
1592 mftbmp_ni = NTFS_I(mftbmp_vi);
1593 /* Get the attribute record. */
1594 mrec = map_mft_record(mft_ni);
1595 if (IS_ERR(mrec)) {
1596 ntfs_error(vol->sb, "Failed to map mft record.");
1597 return PTR_ERR(mrec);
1598 }
1599 ctx = ntfs_attr_get_search_ctx(mft_ni, mrec);
1600 if (unlikely(!ctx)) {
1601 ntfs_error(vol->sb, "Failed to get search context.");
1602 ret = -ENOMEM;
1603 goto unm_err_out;
1604 }
1605 ret = ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name,
1606 mftbmp_ni->name_len, CASE_SENSITIVE, 0, NULL, 0, ctx);
1607 if (unlikely(ret)) {
1608 ntfs_error(vol->sb, "Failed to find first attribute extent of "
1609 "mft bitmap attribute.");
1610 if (ret == -ENOENT)
1611 ret = -EIO;
1612 goto put_err_out;
1613 }
1614 a = ctx->attr;
1615 write_lock_irqsave(&mftbmp_ni->size_lock, flags);
1616 old_data_size = i_size_read(mftbmp_vi);
1617 old_initialized_size = mftbmp_ni->initialized_size;
1618 /*
1619 * We can simply update the initialized_size before filling the space
1620 * with zeroes because the caller is holding the mft bitmap lock for
1621 * writing which ensures that no one else is trying to access the data.
1622 */
1623 mftbmp_ni->initialized_size += 8;
1624 a->data.non_resident.initialized_size =
1625 cpu_to_sle64(mftbmp_ni->initialized_size);
1626 if (mftbmp_ni->initialized_size > old_data_size) {
1627 i_size_write(mftbmp_vi, mftbmp_ni->initialized_size);
1628 a->data.non_resident.data_size =
1629 cpu_to_sle64(mftbmp_ni->initialized_size);
1630 }
1631 write_unlock_irqrestore(&mftbmp_ni->size_lock, flags);
1632 /* Ensure the changes make it to disk. */
1633 flush_dcache_mft_record_page(ctx->ntfs_ino);
1634 mark_mft_record_dirty(ctx->ntfs_ino);
1635 ntfs_attr_put_search_ctx(ctx);
1636 unmap_mft_record(mft_ni);
1637 /* Initialize the mft bitmap attribute value with zeroes. */
1638 ret = ntfs_attr_set(mftbmp_ni, old_initialized_size, 8, 0);
1639 if (likely(!ret)) {
1640 ntfs_debug("Done. (Wrote eight initialized bytes to mft "
1641 "bitmap.");
1642 return 0;
1643 }
1644 ntfs_error(vol->sb, "Failed to write to mft bitmap.");
1645 /* Try to recover from the error. */
1646 mrec = map_mft_record(mft_ni);
1647 if (IS_ERR(mrec)) {
1648 ntfs_error(vol->sb, "Failed to map mft record.%s", es);
1649 NVolSetErrors(vol);
1650 return ret;
1651 }
1652 ctx = ntfs_attr_get_search_ctx(mft_ni, mrec);
1653 if (unlikely(!ctx)) {
1654 ntfs_error(vol->sb, "Failed to get search context.%s", es);
1655 NVolSetErrors(vol);
1656 goto unm_err_out;
1657 }
1658 if (ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name,
1659 mftbmp_ni->name_len, CASE_SENSITIVE, 0, NULL, 0, ctx)) {
1660 ntfs_error(vol->sb, "Failed to find first attribute extent of "
1661 "mft bitmap attribute.%s", es);
1662 NVolSetErrors(vol);
1663put_err_out:
1664 ntfs_attr_put_search_ctx(ctx);
1665unm_err_out:
1666 unmap_mft_record(mft_ni);
1667 goto err_out;
1668 }
1669 a = ctx->attr;
1670 write_lock_irqsave(&mftbmp_ni->size_lock, flags);
1671 mftbmp_ni->initialized_size = old_initialized_size;
1672 a->data.non_resident.initialized_size =
1673 cpu_to_sle64(old_initialized_size);
1674 if (i_size_read(mftbmp_vi) != old_data_size) {
1675 i_size_write(mftbmp_vi, old_data_size);
1676 a->data.non_resident.data_size = cpu_to_sle64(old_data_size);
1677 }
1678 write_unlock_irqrestore(&mftbmp_ni->size_lock, flags);
1679 flush_dcache_mft_record_page(ctx->ntfs_ino);
1680 mark_mft_record_dirty(ctx->ntfs_ino);
1681 ntfs_attr_put_search_ctx(ctx);
1682 unmap_mft_record(mft_ni);
1683#ifdef DEBUG
1684 read_lock_irqsave(&mftbmp_ni->size_lock, flags);
1685 ntfs_debug("Restored status of mftbmp: allocated_size 0x%llx, "
1686 "data_size 0x%llx, initialized_size 0x%llx.",
1687 (long long)mftbmp_ni->allocated_size,
1688 (long long)i_size_read(mftbmp_vi),
1689 (long long)mftbmp_ni->initialized_size);
1690 read_unlock_irqrestore(&mftbmp_ni->size_lock, flags);
1691#endif /* DEBUG */
1692err_out:
1693 return ret;
1694}
1695
1696/**
1697 * ntfs_mft_data_extend_allocation_nolock - extend mft data attribute
1698 * @vol: volume on which to extend the mft data attribute
1699 *
1700 * Extend the mft data attribute on the ntfs volume @vol by 16 mft records
1701 * worth of clusters or if not enough space for this by one mft record worth
1702 * of clusters.
1703 *
1704 * Note: Only changes allocated_size, i.e. does not touch initialized_size or
1705 * data_size.
1706 *
1707 * Return 0 on success and -errno on error.
1708 *
1709 * Locking: - Caller must hold vol->mftbmp_lock for writing.
1710 * - This function takes NTFS_I(vol->mft_ino)->runlist.lock for
1711 * writing and releases it before returning.
1712 * - This function calls functions which take vol->lcnbmp_lock for
1713 * writing and release it before returning.
1714 */
1715static int ntfs_mft_data_extend_allocation_nolock(ntfs_volume *vol)
1716{
1717 LCN lcn;
1718 VCN old_last_vcn;
1719 s64 min_nr, nr, ll;
1720 unsigned long flags;
1721 ntfs_inode *mft_ni;
1722 runlist_element *rl, *rl2;
1723 ntfs_attr_search_ctx *ctx = NULL;
1724 MFT_RECORD *mrec;
1725 ATTR_RECORD *a = NULL;
1726 int ret, mp_size;
1727 u32 old_alen = 0;
1728 bool mp_rebuilt = false;
1729
1730 ntfs_debug("Extending mft data allocation.");
1731 mft_ni = NTFS_I(vol->mft_ino);
1732 /*
1733 * Determine the preferred allocation location, i.e. the last lcn of
1734 * the mft data attribute. The allocated size of the mft data
1735 * attribute cannot be zero so we are ok to do this.
1736 */
1737 down_write(&mft_ni->runlist.lock);
1738 read_lock_irqsave(&mft_ni->size_lock, flags);
1739 ll = mft_ni->allocated_size;
1740 read_unlock_irqrestore(&mft_ni->size_lock, flags);
1741 rl = ntfs_attr_find_vcn_nolock(mft_ni,
1742 (ll - 1) >> vol->cluster_size_bits, NULL);
1743 if (unlikely(IS_ERR(rl) || !rl->length || rl->lcn < 0)) {
1744 up_write(&mft_ni->runlist.lock);
1745 ntfs_error(vol->sb, "Failed to determine last allocated "
1746 "cluster of mft data attribute.");
1747 if (!IS_ERR(rl))
1748 ret = -EIO;
1749 else
1750 ret = PTR_ERR(rl);
1751 return ret;
1752 }
1753 lcn = rl->lcn + rl->length;
1754 ntfs_debug("Last lcn of mft data attribute is 0x%llx.", (long long)lcn);
1755 /* Minimum allocation is one mft record worth of clusters. */
1756 min_nr = vol->mft_record_size >> vol->cluster_size_bits;
1757 if (!min_nr)
1758 min_nr = 1;
1759 /* Want to allocate 16 mft records worth of clusters. */
1760 nr = vol->mft_record_size << 4 >> vol->cluster_size_bits;
1761 if (!nr)
1762 nr = min_nr;
1763 /* Ensure we do not go above 2^32-1 mft records. */
1764 read_lock_irqsave(&mft_ni->size_lock, flags);
1765 ll = mft_ni->allocated_size;
1766 read_unlock_irqrestore(&mft_ni->size_lock, flags);
1767 if (unlikely((ll + (nr << vol->cluster_size_bits)) >>
1768 vol->mft_record_size_bits >= (1ll << 32))) {
1769 nr = min_nr;
1770 if (unlikely((ll + (nr << vol->cluster_size_bits)) >>
1771 vol->mft_record_size_bits >= (1ll << 32))) {
1772 ntfs_warning(vol->sb, "Cannot allocate mft record "
1773 "because the maximum number of inodes "
1774 "(2^32) has already been reached.");
1775 up_write(&mft_ni->runlist.lock);
1776 return -ENOSPC;
1777 }
1778 }
1779 ntfs_debug("Trying mft data allocation with %s cluster count %lli.",
1780 nr > min_nr ? "default" : "minimal", (long long)nr);
1781 old_last_vcn = rl[1].vcn;
1782 do {
1783 rl2 = ntfs_cluster_alloc(vol, old_last_vcn, nr, lcn, MFT_ZONE,
1784 true);
1785 if (likely(!IS_ERR(rl2)))
1786 break;
1787 if (PTR_ERR(rl2) != -ENOSPC || nr == min_nr) {
1788 ntfs_error(vol->sb, "Failed to allocate the minimal "
1789 "number of clusters (%lli) for the "
1790 "mft data attribute.", (long long)nr);
1791 up_write(&mft_ni->runlist.lock);
1792 return PTR_ERR(rl2);
1793 }
1794 /*
1795 * There is not enough space to do the allocation, but there
1796 * might be enough space to do a minimal allocation so try that
1797 * before failing.
1798 */
1799 nr = min_nr;
1800 ntfs_debug("Retrying mft data allocation with minimal cluster "
1801 "count %lli.", (long long)nr);
1802 } while (1);
1803 rl = ntfs_runlists_merge(mft_ni->runlist.rl, rl2);
1804 if (IS_ERR(rl)) {
1805 up_write(&mft_ni->runlist.lock);
1806 ntfs_error(vol->sb, "Failed to merge runlists for mft data "
1807 "attribute.");
1808 if (ntfs_cluster_free_from_rl(vol, rl2)) {
1809 ntfs_error(vol->sb, "Failed to deallocate clusters "
1810 "from the mft data attribute.%s", es);
1811 NVolSetErrors(vol);
1812 }
1813 ntfs_free(rl2);
1814 return PTR_ERR(rl);
1815 }
1816 mft_ni->runlist.rl = rl;
1817 ntfs_debug("Allocated %lli clusters.", (long long)nr);
1818 /* Find the last run in the new runlist. */
1819 for (; rl[1].length; rl++)
1820 ;
1821 /* Update the attribute record as well. */
1822 mrec = map_mft_record(mft_ni);
1823 if (IS_ERR(mrec)) {
1824 ntfs_error(vol->sb, "Failed to map mft record.");
1825 ret = PTR_ERR(mrec);
1826 goto undo_alloc;
1827 }
1828 ctx = ntfs_attr_get_search_ctx(mft_ni, mrec);
1829 if (unlikely(!ctx)) {
1830 ntfs_error(vol->sb, "Failed to get search context.");
1831 ret = -ENOMEM;
1832 goto undo_alloc;
1833 }
1834 ret = ntfs_attr_lookup(mft_ni->type, mft_ni->name, mft_ni->name_len,
1835 CASE_SENSITIVE, rl[1].vcn, NULL, 0, ctx);
1836 if (unlikely(ret)) {
1837 ntfs_error(vol->sb, "Failed to find last attribute extent of "
1838 "mft data attribute.");
1839 if (ret == -ENOENT)
1840 ret = -EIO;
1841 goto undo_alloc;
1842 }
1843 a = ctx->attr;
1844 ll = sle64_to_cpu(a->data.non_resident.lowest_vcn);
1845 /* Search back for the previous last allocated cluster of mft bitmap. */
1846 for (rl2 = rl; rl2 > mft_ni->runlist.rl; rl2--) {
1847 if (ll >= rl2->vcn)
1848 break;
1849 }
1850 BUG_ON(ll < rl2->vcn);
1851 BUG_ON(ll >= rl2->vcn + rl2->length);
1852 /* Get the size for the new mapping pairs array for this extent. */
1853 mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, ll, -1);
1854 if (unlikely(mp_size <= 0)) {
1855 ntfs_error(vol->sb, "Get size for mapping pairs failed for "
1856 "mft data attribute extent.");
1857 ret = mp_size;
1858 if (!ret)
1859 ret = -EIO;
1860 goto undo_alloc;
1861 }
1862 /* Expand the attribute record if necessary. */
1863 old_alen = le32_to_cpu(a->length);
1864 ret = ntfs_attr_record_resize(ctx->mrec, a, mp_size +
1865 le16_to_cpu(a->data.non_resident.mapping_pairs_offset));
1866 if (unlikely(ret)) {
1867 if (ret != -ENOSPC) {
1868 ntfs_error(vol->sb, "Failed to resize attribute "
1869 "record for mft data attribute.");
1870 goto undo_alloc;
1871 }
1872 // TODO: Deal with this by moving this extent to a new mft
1873 // record or by starting a new extent in a new mft record or by
1874 // moving other attributes out of this mft record.
1875 // Note: Use the special reserved mft records and ensure that
1876 // this extent is not required to find the mft record in
1877 // question. If no free special records left we would need to
1878 // move an existing record away, insert ours in its place, and
1879 // then place the moved record into the newly allocated space
1880 // and we would then need to update all references to this mft
1881 // record appropriately. This is rather complicated...
1882 ntfs_error(vol->sb, "Not enough space in this mft record to "
1883 "accommodate extended mft data attribute "
1884 "extent. Cannot handle this yet.");
1885 ret = -EOPNOTSUPP;
1886 goto undo_alloc;
1887 }
1888 mp_rebuilt = true;
1889 /* Generate the mapping pairs array directly into the attr record. */
1890 ret = ntfs_mapping_pairs_build(vol, (u8*)a +
1891 le16_to_cpu(a->data.non_resident.mapping_pairs_offset),
1892 mp_size, rl2, ll, -1, NULL);
1893 if (unlikely(ret)) {
1894 ntfs_error(vol->sb, "Failed to build mapping pairs array of "
1895 "mft data attribute.");
1896 goto undo_alloc;
1897 }
1898 /* Update the highest_vcn. */
1899 a->data.non_resident.highest_vcn = cpu_to_sle64(rl[1].vcn - 1);
1900 /*
1901 * We now have extended the mft data allocated_size by nr clusters.
1902 * Reflect this in the ntfs_inode structure and the attribute record.
1903 * @rl is the last (non-terminator) runlist element of mft data
1904 * attribute.
1905 */
1906 if (a->data.non_resident.lowest_vcn) {
1907 /*
1908 * We are not in the first attribute extent, switch to it, but
1909 * first ensure the changes will make it to disk later.
1910 */
1911 flush_dcache_mft_record_page(ctx->ntfs_ino);
1912 mark_mft_record_dirty(ctx->ntfs_ino);
1913 ntfs_attr_reinit_search_ctx(ctx);
1914 ret = ntfs_attr_lookup(mft_ni->type, mft_ni->name,
1915 mft_ni->name_len, CASE_SENSITIVE, 0, NULL, 0,
1916 ctx);
1917 if (unlikely(ret)) {
1918 ntfs_error(vol->sb, "Failed to find first attribute "
1919 "extent of mft data attribute.");
1920 goto restore_undo_alloc;
1921 }
1922 a = ctx->attr;
1923 }
1924 write_lock_irqsave(&mft_ni->size_lock, flags);
1925 mft_ni->allocated_size += nr << vol->cluster_size_bits;
1926 a->data.non_resident.allocated_size =
1927 cpu_to_sle64(mft_ni->allocated_size);
1928 write_unlock_irqrestore(&mft_ni->size_lock, flags);
1929 /* Ensure the changes make it to disk. */
1930 flush_dcache_mft_record_page(ctx->ntfs_ino);
1931 mark_mft_record_dirty(ctx->ntfs_ino);
1932 ntfs_attr_put_search_ctx(ctx);
1933 unmap_mft_record(mft_ni);
1934 up_write(&mft_ni->runlist.lock);
1935 ntfs_debug("Done.");
1936 return 0;
1937restore_undo_alloc:
1938 ntfs_attr_reinit_search_ctx(ctx);
1939 if (ntfs_attr_lookup(mft_ni->type, mft_ni->name, mft_ni->name_len,
1940 CASE_SENSITIVE, rl[1].vcn, NULL, 0, ctx)) {
1941 ntfs_error(vol->sb, "Failed to find last attribute extent of "
1942 "mft data attribute.%s", es);
1943 write_lock_irqsave(&mft_ni->size_lock, flags);
1944 mft_ni->allocated_size += nr << vol->cluster_size_bits;
1945 write_unlock_irqrestore(&mft_ni->size_lock, flags);
1946 ntfs_attr_put_search_ctx(ctx);
1947 unmap_mft_record(mft_ni);
1948 up_write(&mft_ni->runlist.lock);
1949 /*
1950 * The only thing that is now wrong is ->allocated_size of the
1951 * base attribute extent which chkdsk should be able to fix.
1952 */
1953 NVolSetErrors(vol);
1954 return ret;
1955 }
1956 ctx->attr->data.non_resident.highest_vcn =
1957 cpu_to_sle64(old_last_vcn - 1);
1958undo_alloc:
1959 if (ntfs_cluster_free(mft_ni, old_last_vcn, -1, ctx) < 0) {
1960 ntfs_error(vol->sb, "Failed to free clusters from mft data "
1961 "attribute.%s", es);
1962 NVolSetErrors(vol);
1963 }
1964 a = ctx->attr;
1965 if (ntfs_rl_truncate_nolock(vol, &mft_ni->runlist, old_last_vcn)) {
1966 ntfs_error(vol->sb, "Failed to truncate mft data attribute "
1967 "runlist.%s", es);
1968 NVolSetErrors(vol);
1969 }
1970 if (mp_rebuilt && !IS_ERR(ctx->mrec)) {
1971 if (ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu(
1972 a->data.non_resident.mapping_pairs_offset),
1973 old_alen - le16_to_cpu(
1974 a->data.non_resident.mapping_pairs_offset),
1975 rl2, ll, -1, NULL)) {
1976 ntfs_error(vol->sb, "Failed to restore mapping pairs "
1977 "array.%s", es);
1978 NVolSetErrors(vol);
1979 }
1980 if (ntfs_attr_record_resize(ctx->mrec, a, old_alen)) {
1981 ntfs_error(vol->sb, "Failed to restore attribute "
1982 "record.%s", es);
1983 NVolSetErrors(vol);
1984 }
1985 flush_dcache_mft_record_page(ctx->ntfs_ino);
1986 mark_mft_record_dirty(ctx->ntfs_ino);
1987 } else if (IS_ERR(ctx->mrec)) {
1988 ntfs_error(vol->sb, "Failed to restore attribute search "
1989 "context.%s", es);
1990 NVolSetErrors(vol);
1991 }
1992 if (ctx)
1993 ntfs_attr_put_search_ctx(ctx);
1994 if (!IS_ERR(mrec))
1995 unmap_mft_record(mft_ni);
1996 up_write(&mft_ni->runlist.lock);
1997 return ret;
1998}
1999
2000/**
2001 * ntfs_mft_record_layout - layout an mft record into a memory buffer
2002 * @vol: volume to which the mft record will belong
2003 * @mft_no: mft reference specifying the mft record number
2004 * @m: destination buffer of size >= @vol->mft_record_size bytes
2005 *
2006 * Layout an empty, unused mft record with the mft record number @mft_no into
2007 * the buffer @m. The volume @vol is needed because the mft record structure
2008 * was modified in NTFS 3.1 so we need to know which volume version this mft
2009 * record will be used on.
2010 *
2011 * Return 0 on success and -errno on error.
2012 */
2013static int ntfs_mft_record_layout(const ntfs_volume *vol, const s64 mft_no,
2014 MFT_RECORD *m)
2015{
2016 ATTR_RECORD *a;
2017
2018 ntfs_debug("Entering for mft record 0x%llx.", (long long)mft_no);
2019 if (mft_no >= (1ll << 32)) {
2020 ntfs_error(vol->sb, "Mft record number 0x%llx exceeds "
2021 "maximum of 2^32.", (long long)mft_no);
2022 return -ERANGE;
2023 }
2024 /* Start by clearing the whole mft record to gives us a clean slate. */
2025 memset(m, 0, vol->mft_record_size);
2026 /* Aligned to 2-byte boundary. */
2027 if (vol->major_ver < 3 || (vol->major_ver == 3 && !vol->minor_ver))
2028 m->usa_ofs = cpu_to_le16((sizeof(MFT_RECORD_OLD) + 1) & ~1);
2029 else {
2030 m->usa_ofs = cpu_to_le16((sizeof(MFT_RECORD) + 1) & ~1);
2031 /*
2032 * Set the NTFS 3.1+ specific fields while we know that the
2033 * volume version is 3.1+.
2034 */
2035 m->reserved = 0;
2036 m->mft_record_number = cpu_to_le32((u32)mft_no);
2037 }
2038 m->magic = magic_FILE;
2039 if (vol->mft_record_size >= NTFS_BLOCK_SIZE)
2040 m->usa_count = cpu_to_le16(vol->mft_record_size /
2041 NTFS_BLOCK_SIZE + 1);
2042 else {
2043 m->usa_count = cpu_to_le16(1);
2044 ntfs_warning(vol->sb, "Sector size is bigger than mft record "
2045 "size. Setting usa_count to 1. If chkdsk "
2046 "reports this as corruption, please email "
2047 "linux-ntfs-dev@lists.sourceforge.net stating "
2048 "that you saw this message and that the "
2049 "modified filesystem created was corrupt. "
2050 "Thank you.");
2051 }
2052 /* Set the update sequence number to 1. */
2053 *(le16*)((u8*)m + le16_to_cpu(m->usa_ofs)) = cpu_to_le16(1);
2054 m->lsn = 0;
2055 m->sequence_number = cpu_to_le16(1);
2056 m->link_count = 0;
2057 /*
2058 * Place the attributes straight after the update sequence array,
2059 * aligned to 8-byte boundary.
2060 */
2061 m->attrs_offset = cpu_to_le16((le16_to_cpu(m->usa_ofs) +
2062 (le16_to_cpu(m->usa_count) << 1) + 7) & ~7);
2063 m->flags = 0;
2064 /*
2065 * Using attrs_offset plus eight bytes (for the termination attribute).
2066 * attrs_offset is already aligned to 8-byte boundary, so no need to
2067 * align again.
2068 */
2069 m->bytes_in_use = cpu_to_le32(le16_to_cpu(m->attrs_offset) + 8);
2070 m->bytes_allocated = cpu_to_le32(vol->mft_record_size);
2071 m->base_mft_record = 0;
2072 m->next_attr_instance = 0;
2073 /* Add the termination attribute. */
2074 a = (ATTR_RECORD*)((u8*)m + le16_to_cpu(m->attrs_offset));
2075 a->type = AT_END;
2076 a->length = 0;
2077 ntfs_debug("Done.");
2078 return 0;
2079}
2080
2081/**
2082 * ntfs_mft_record_format - format an mft record on an ntfs volume
2083 * @vol: volume on which to format the mft record
2084 * @mft_no: mft record number to format
2085 *
2086 * Format the mft record @mft_no in $MFT/$DATA, i.e. lay out an empty, unused
2087 * mft record into the appropriate place of the mft data attribute. This is
2088 * used when extending the mft data attribute.
2089 *
2090 * Return 0 on success and -errno on error.
2091 */
2092static int ntfs_mft_record_format(const ntfs_volume *vol, const s64 mft_no)
2093{
2094 loff_t i_size;
2095 struct inode *mft_vi = vol->mft_ino;
2096 struct page *page;
2097 MFT_RECORD *m;
2098 pgoff_t index, end_index;
2099 unsigned int ofs;
2100 int err;
2101
2102 ntfs_debug("Entering for mft record 0x%llx.", (long long)mft_no);
2103 /*
2104 * The index into the page cache and the offset within the page cache
2105 * page of the wanted mft record.
2106 */
2107 index = mft_no << vol->mft_record_size_bits >> PAGE_SHIFT;
2108 ofs = (mft_no << vol->mft_record_size_bits) & ~PAGE_MASK;
2109 /* The maximum valid index into the page cache for $MFT's data. */
2110 i_size = i_size_read(mft_vi);
2111 end_index = i_size >> PAGE_SHIFT;
2112 if (unlikely(index >= end_index)) {
2113 if (unlikely(index > end_index || ofs + vol->mft_record_size >=
2114 (i_size & ~PAGE_MASK))) {
2115 ntfs_error(vol->sb, "Tried to format non-existing mft "
2116 "record 0x%llx.", (long long)mft_no);
2117 return -ENOENT;
2118 }
2119 }
2120 /* Read, map, and pin the page containing the mft record. */
2121 page = ntfs_map_page(mft_vi->i_mapping, index);
2122 if (IS_ERR(page)) {
2123 ntfs_error(vol->sb, "Failed to map page containing mft record "
2124 "to format 0x%llx.", (long long)mft_no);
2125 return PTR_ERR(page);
2126 }
2127 lock_page(page);
2128 BUG_ON(!PageUptodate(page));
2129 ClearPageUptodate(page);
2130 m = (MFT_RECORD*)((u8*)page_address(page) + ofs);
2131 err = ntfs_mft_record_layout(vol, mft_no, m);
2132 if (unlikely(err)) {
2133 ntfs_error(vol->sb, "Failed to layout mft record 0x%llx.",
2134 (long long)mft_no);
2135 SetPageUptodate(page);
2136 unlock_page(page);
2137 ntfs_unmap_page(page);
2138 return err;
2139 }
2140 flush_dcache_page(page);
2141 SetPageUptodate(page);
2142 unlock_page(page);
2143 /*
2144 * Make sure the mft record is written out to disk. We could use
2145 * ilookup5() to check if an inode is in icache and so on but this is
2146 * unnecessary as ntfs_writepage() will write the dirty record anyway.
2147 */
2148 mark_ntfs_record_dirty(page, ofs);
2149 ntfs_unmap_page(page);
2150 ntfs_debug("Done.");
2151 return 0;
2152}
2153
2154/**
2155 * ntfs_mft_record_alloc - allocate an mft record on an ntfs volume
2156 * @vol: [IN] volume on which to allocate the mft record
2157 * @mode: [IN] mode if want a file or directory, i.e. base inode or 0
2158 * @base_ni: [IN] open base inode if allocating an extent mft record or NULL
2159 * @mrec: [OUT] on successful return this is the mapped mft record
2160 *
2161 * Allocate an mft record in $MFT/$DATA of an open ntfs volume @vol.
2162 *
2163 * If @base_ni is NULL make the mft record a base mft record, i.e. a file or
2164 * direvctory inode, and allocate it at the default allocator position. In
2165 * this case @mode is the file mode as given to us by the caller. We in
2166 * particular use @mode to distinguish whether a file or a directory is being
2167 * created (S_IFDIR(mode) and S_IFREG(mode), respectively).
2168 *
2169 * If @base_ni is not NULL make the allocated mft record an extent record,
2170 * allocate it starting at the mft record after the base mft record and attach
2171 * the allocated and opened ntfs inode to the base inode @base_ni. In this
2172 * case @mode must be 0 as it is meaningless for extent inodes.
2173 *
2174 * You need to check the return value with IS_ERR(). If false, the function
2175 * was successful and the return value is the now opened ntfs inode of the
2176 * allocated mft record. *@mrec is then set to the allocated, mapped, pinned,
2177 * and locked mft record. If IS_ERR() is true, the function failed and the
2178 * error code is obtained from PTR_ERR(return value). *@mrec is undefined in
2179 * this case.
2180 *
2181 * Allocation strategy:
2182 *
2183 * To find a free mft record, we scan the mft bitmap for a zero bit. To
2184 * optimize this we start scanning at the place specified by @base_ni or if
2185 * @base_ni is NULL we start where we last stopped and we perform wrap around
2186 * when we reach the end. Note, we do not try to allocate mft records below
2187 * number 24 because numbers 0 to 15 are the defined system files anyway and 16
2188 * to 24 are special in that they are used for storing extension mft records
2189 * for the $DATA attribute of $MFT. This is required to avoid the possibility
2190 * of creating a runlist with a circular dependency which once written to disk
2191 * can never be read in again. Windows will only use records 16 to 24 for
2192 * normal files if the volume is completely out of space. We never use them
2193 * which means that when the volume is really out of space we cannot create any
2194 * more files while Windows can still create up to 8 small files. We can start
2195 * doing this at some later time, it does not matter much for now.
2196 *
2197 * When scanning the mft bitmap, we only search up to the last allocated mft
2198 * record. If there are no free records left in the range 24 to number of
2199 * allocated mft records, then we extend the $MFT/$DATA attribute in order to
2200 * create free mft records. We extend the allocated size of $MFT/$DATA by 16
2201 * records at a time or one cluster, if cluster size is above 16kiB. If there
2202 * is not sufficient space to do this, we try to extend by a single mft record
2203 * or one cluster, if cluster size is above the mft record size.
2204 *
2205 * No matter how many mft records we allocate, we initialize only the first
2206 * allocated mft record, incrementing mft data size and initialized size
2207 * accordingly, open an ntfs_inode for it and return it to the caller, unless
2208 * there are less than 24 mft records, in which case we allocate and initialize
2209 * mft records until we reach record 24 which we consider as the first free mft
2210 * record for use by normal files.
2211 *
2212 * If during any stage we overflow the initialized data in the mft bitmap, we
2213 * extend the initialized size (and data size) by 8 bytes, allocating another
2214 * cluster if required. The bitmap data size has to be at least equal to the
2215 * number of mft records in the mft, but it can be bigger, in which case the
2216 * superflous bits are padded with zeroes.
2217 *
2218 * Thus, when we return successfully (IS_ERR() is false), we will have:
2219 * - initialized / extended the mft bitmap if necessary,
2220 * - initialized / extended the mft data if necessary,
2221 * - set the bit corresponding to the mft record being allocated in the
2222 * mft bitmap,
2223 * - opened an ntfs_inode for the allocated mft record, and we will have
2224 * - returned the ntfs_inode as well as the allocated mapped, pinned, and
2225 * locked mft record.
2226 *
2227 * On error, the volume will be left in a consistent state and no record will
2228 * be allocated. If rolling back a partial operation fails, we may leave some
2229 * inconsistent metadata in which case we set NVolErrors() so the volume is
2230 * left dirty when unmounted.
2231 *
2232 * Note, this function cannot make use of most of the normal functions, like
2233 * for example for attribute resizing, etc, because when the run list overflows
2234 * the base mft record and an attribute list is used, it is very important that
2235 * the extension mft records used to store the $DATA attribute of $MFT can be
2236 * reached without having to read the information contained inside them, as
2237 * this would make it impossible to find them in the first place after the
2238 * volume is unmounted. $MFT/$BITMAP probably does not need to follow this
2239 * rule because the bitmap is not essential for finding the mft records, but on
2240 * the other hand, handling the bitmap in this special way would make life
2241 * easier because otherwise there might be circular invocations of functions
2242 * when reading the bitmap.
2243 */
2244ntfs_inode *ntfs_mft_record_alloc(ntfs_volume *vol, const int mode,
2245 ntfs_inode *base_ni, MFT_RECORD **mrec)
2246{
2247 s64 ll, bit, old_data_initialized, old_data_size;
2248 unsigned long flags;
2249 struct inode *vi;
2250 struct page *page;
2251 ntfs_inode *mft_ni, *mftbmp_ni, *ni;
2252 ntfs_attr_search_ctx *ctx;
2253 MFT_RECORD *m;
2254 ATTR_RECORD *a;
2255 pgoff_t index;
2256 unsigned int ofs;
2257 int err;
2258 le16 seq_no, usn;
2259 bool record_formatted = false;
2260
2261 if (base_ni) {
2262 ntfs_debug("Entering (allocating an extent mft record for "
2263 "base mft record 0x%llx).",
2264 (long long)base_ni->mft_no);
2265 /* @mode and @base_ni are mutually exclusive. */
2266 BUG_ON(mode);
2267 } else
2268 ntfs_debug("Entering (allocating a base mft record).");
2269 if (mode) {
2270 /* @mode and @base_ni are mutually exclusive. */
2271 BUG_ON(base_ni);
2272 /* We only support creation of normal files and directories. */
2273 if (!S_ISREG(mode) && !S_ISDIR(mode))
2274 return ERR_PTR(-EOPNOTSUPP);
2275 }
2276 BUG_ON(!mrec);
2277 mft_ni = NTFS_I(vol->mft_ino);
2278 mftbmp_ni = NTFS_I(vol->mftbmp_ino);
2279 down_write(&vol->mftbmp_lock);
2280 bit = ntfs_mft_bitmap_find_and_alloc_free_rec_nolock(vol, base_ni);
2281 if (bit >= 0) {
2282 ntfs_debug("Found and allocated free record (#1), bit 0x%llx.",
2283 (long long)bit);
2284 goto have_alloc_rec;
2285 }
2286 if (bit != -ENOSPC) {
2287 up_write(&vol->mftbmp_lock);
2288 return ERR_PTR(bit);
2289 }
2290 /*
2291 * No free mft records left. If the mft bitmap already covers more
2292 * than the currently used mft records, the next records are all free,
2293 * so we can simply allocate the first unused mft record.
2294 * Note: We also have to make sure that the mft bitmap at least covers
2295 * the first 24 mft records as they are special and whilst they may not
2296 * be in use, we do not allocate from them.
2297 */
2298 read_lock_irqsave(&mft_ni->size_lock, flags);
2299 ll = mft_ni->initialized_size >> vol->mft_record_size_bits;
2300 read_unlock_irqrestore(&mft_ni->size_lock, flags);
2301 read_lock_irqsave(&mftbmp_ni->size_lock, flags);
2302 old_data_initialized = mftbmp_ni->initialized_size;
2303 read_unlock_irqrestore(&mftbmp_ni->size_lock, flags);
2304 if (old_data_initialized << 3 > ll && old_data_initialized > 3) {
2305 bit = ll;
2306 if (bit < 24)
2307 bit = 24;
2308 if (unlikely(bit >= (1ll << 32)))
2309 goto max_err_out;
2310 ntfs_debug("Found free record (#2), bit 0x%llx.",
2311 (long long)bit);
2312 goto found_free_rec;
2313 }
2314 /*
2315 * The mft bitmap needs to be expanded until it covers the first unused
2316 * mft record that we can allocate.
2317 * Note: The smallest mft record we allocate is mft record 24.
2318 */
2319 bit = old_data_initialized << 3;
2320 if (unlikely(bit >= (1ll << 32)))
2321 goto max_err_out;
2322 read_lock_irqsave(&mftbmp_ni->size_lock, flags);
2323 old_data_size = mftbmp_ni->allocated_size;
2324 ntfs_debug("Status of mftbmp before extension: allocated_size 0x%llx, "
2325 "data_size 0x%llx, initialized_size 0x%llx.",
2326 (long long)old_data_size,
2327 (long long)i_size_read(vol->mftbmp_ino),
2328 (long long)old_data_initialized);
2329 read_unlock_irqrestore(&mftbmp_ni->size_lock, flags);
2330 if (old_data_initialized + 8 > old_data_size) {
2331 /* Need to extend bitmap by one more cluster. */
2332 ntfs_debug("mftbmp: initialized_size + 8 > allocated_size.");
2333 err = ntfs_mft_bitmap_extend_allocation_nolock(vol);
2334 if (unlikely(err)) {
2335 up_write(&vol->mftbmp_lock);
2336 goto err_out;
2337 }
2338#ifdef DEBUG
2339 read_lock_irqsave(&mftbmp_ni->size_lock, flags);
2340 ntfs_debug("Status of mftbmp after allocation extension: "
2341 "allocated_size 0x%llx, data_size 0x%llx, "
2342 "initialized_size 0x%llx.",
2343 (long long)mftbmp_ni->allocated_size,
2344 (long long)i_size_read(vol->mftbmp_ino),
2345 (long long)mftbmp_ni->initialized_size);
2346 read_unlock_irqrestore(&mftbmp_ni->size_lock, flags);
2347#endif /* DEBUG */
2348 }
2349 /*
2350 * We now have sufficient allocated space, extend the initialized_size
2351 * as well as the data_size if necessary and fill the new space with
2352 * zeroes.
2353 */
2354 err = ntfs_mft_bitmap_extend_initialized_nolock(vol);
2355 if (unlikely(err)) {
2356 up_write(&vol->mftbmp_lock);
2357 goto err_out;
2358 }
2359#ifdef DEBUG
2360 read_lock_irqsave(&mftbmp_ni->size_lock, flags);
2361 ntfs_debug("Status of mftbmp after initialized extension: "
2362 "allocated_size 0x%llx, data_size 0x%llx, "
2363 "initialized_size 0x%llx.",
2364 (long long)mftbmp_ni->allocated_size,
2365 (long long)i_size_read(vol->mftbmp_ino),
2366 (long long)mftbmp_ni->initialized_size);
2367 read_unlock_irqrestore(&mftbmp_ni->size_lock, flags);
2368#endif /* DEBUG */
2369 ntfs_debug("Found free record (#3), bit 0x%llx.", (long long)bit);
2370found_free_rec:
2371 /* @bit is the found free mft record, allocate it in the mft bitmap. */
2372 ntfs_debug("At found_free_rec.");
2373 err = ntfs_bitmap_set_bit(vol->mftbmp_ino, bit);
2374 if (unlikely(err)) {
2375 ntfs_error(vol->sb, "Failed to allocate bit in mft bitmap.");
2376 up_write(&vol->mftbmp_lock);
2377 goto err_out;
2378 }
2379 ntfs_debug("Set bit 0x%llx in mft bitmap.", (long long)bit);
2380have_alloc_rec:
2381 /*
2382 * The mft bitmap is now uptodate. Deal with mft data attribute now.
2383 * Note, we keep hold of the mft bitmap lock for writing until all
2384 * modifications to the mft data attribute are complete, too, as they
2385 * will impact decisions for mft bitmap and mft record allocation done
2386 * by a parallel allocation and if the lock is not maintained a
2387 * parallel allocation could allocate the same mft record as this one.
2388 */
2389 ll = (bit + 1) << vol->mft_record_size_bits;
2390 read_lock_irqsave(&mft_ni->size_lock, flags);
2391 old_data_initialized = mft_ni->initialized_size;
2392 read_unlock_irqrestore(&mft_ni->size_lock, flags);
2393 if (ll <= old_data_initialized) {
2394 ntfs_debug("Allocated mft record already initialized.");
2395 goto mft_rec_already_initialized;
2396 }
2397 ntfs_debug("Initializing allocated mft record.");
2398 /*
2399 * The mft record is outside the initialized data. Extend the mft data
2400 * attribute until it covers the allocated record. The loop is only
2401 * actually traversed more than once when a freshly formatted volume is
2402 * first written to so it optimizes away nicely in the common case.
2403 */
2404 read_lock_irqsave(&mft_ni->size_lock, flags);
2405 ntfs_debug("Status of mft data before extension: "
2406 "allocated_size 0x%llx, data_size 0x%llx, "
2407 "initialized_size 0x%llx.",
2408 (long long)mft_ni->allocated_size,
2409 (long long)i_size_read(vol->mft_ino),
2410 (long long)mft_ni->initialized_size);
2411 while (ll > mft_ni->allocated_size) {
2412 read_unlock_irqrestore(&mft_ni->size_lock, flags);
2413 err = ntfs_mft_data_extend_allocation_nolock(vol);
2414 if (unlikely(err)) {
2415 ntfs_error(vol->sb, "Failed to extend mft data "
2416 "allocation.");
2417 goto undo_mftbmp_alloc_nolock;
2418 }
2419 read_lock_irqsave(&mft_ni->size_lock, flags);
2420 ntfs_debug("Status of mft data after allocation extension: "
2421 "allocated_size 0x%llx, data_size 0x%llx, "
2422 "initialized_size 0x%llx.",
2423 (long long)mft_ni->allocated_size,
2424 (long long)i_size_read(vol->mft_ino),
2425 (long long)mft_ni->initialized_size);
2426 }
2427 read_unlock_irqrestore(&mft_ni->size_lock, flags);
2428 /*
2429 * Extend mft data initialized size (and data size of course) to reach
2430 * the allocated mft record, formatting the mft records allong the way.
2431 * Note: We only modify the ntfs_inode structure as that is all that is
2432 * needed by ntfs_mft_record_format(). We will update the attribute
2433 * record itself in one fell swoop later on.
2434 */
2435 write_lock_irqsave(&mft_ni->size_lock, flags);
2436 old_data_initialized = mft_ni->initialized_size;
2437 old_data_size = vol->mft_ino->i_size;
2438 while (ll > mft_ni->initialized_size) {
2439 s64 new_initialized_size, mft_no;
2440
2441 new_initialized_size = mft_ni->initialized_size +
2442 vol->mft_record_size;
2443 mft_no = mft_ni->initialized_size >> vol->mft_record_size_bits;
2444 if (new_initialized_size > i_size_read(vol->mft_ino))
2445 i_size_write(vol->mft_ino, new_initialized_size);
2446 write_unlock_irqrestore(&mft_ni->size_lock, flags);
2447 ntfs_debug("Initializing mft record 0x%llx.",
2448 (long long)mft_no);
2449 err = ntfs_mft_record_format(vol, mft_no);
2450 if (unlikely(err)) {
2451 ntfs_error(vol->sb, "Failed to format mft record.");
2452 goto undo_data_init;
2453 }
2454 write_lock_irqsave(&mft_ni->size_lock, flags);
2455 mft_ni->initialized_size = new_initialized_size;
2456 }
2457 write_unlock_irqrestore(&mft_ni->size_lock, flags);
2458 record_formatted = true;
2459 /* Update the mft data attribute record to reflect the new sizes. */
2460 m = map_mft_record(mft_ni);
2461 if (IS_ERR(m)) {
2462 ntfs_error(vol->sb, "Failed to map mft record.");
2463 err = PTR_ERR(m);
2464 goto undo_data_init;
2465 }
2466 ctx = ntfs_attr_get_search_ctx(mft_ni, m);
2467 if (unlikely(!ctx)) {
2468 ntfs_error(vol->sb, "Failed to get search context.");
2469 err = -ENOMEM;
2470 unmap_mft_record(mft_ni);
2471 goto undo_data_init;
2472 }
2473 err = ntfs_attr_lookup(mft_ni->type, mft_ni->name, mft_ni->name_len,
2474 CASE_SENSITIVE, 0, NULL, 0, ctx);
2475 if (unlikely(err)) {
2476 ntfs_error(vol->sb, "Failed to find first attribute extent of "
2477 "mft data attribute.");
2478 ntfs_attr_put_search_ctx(ctx);
2479 unmap_mft_record(mft_ni);
2480 goto undo_data_init;
2481 }
2482 a = ctx->attr;
2483 read_lock_irqsave(&mft_ni->size_lock, flags);
2484 a->data.non_resident.initialized_size =
2485 cpu_to_sle64(mft_ni->initialized_size);
2486 a->data.non_resident.data_size =
2487 cpu_to_sle64(i_size_read(vol->mft_ino));
2488 read_unlock_irqrestore(&mft_ni->size_lock, flags);
2489 /* Ensure the changes make it to disk. */
2490 flush_dcache_mft_record_page(ctx->ntfs_ino);
2491 mark_mft_record_dirty(ctx->ntfs_ino);
2492 ntfs_attr_put_search_ctx(ctx);
2493 unmap_mft_record(mft_ni);
2494 read_lock_irqsave(&mft_ni->size_lock, flags);
2495 ntfs_debug("Status of mft data after mft record initialization: "
2496 "allocated_size 0x%llx, data_size 0x%llx, "
2497 "initialized_size 0x%llx.",
2498 (long long)mft_ni->allocated_size,
2499 (long long)i_size_read(vol->mft_ino),
2500 (long long)mft_ni->initialized_size);
2501 BUG_ON(i_size_read(vol->mft_ino) > mft_ni->allocated_size);
2502 BUG_ON(mft_ni->initialized_size > i_size_read(vol->mft_ino));
2503 read_unlock_irqrestore(&mft_ni->size_lock, flags);
2504mft_rec_already_initialized:
2505 /*
2506 * We can finally drop the mft bitmap lock as the mft data attribute
2507 * has been fully updated. The only disparity left is that the
2508 * allocated mft record still needs to be marked as in use to match the
2509 * set bit in the mft bitmap but this is actually not a problem since
2510 * this mft record is not referenced from anywhere yet and the fact
2511 * that it is allocated in the mft bitmap means that no-one will try to
2512 * allocate it either.
2513 */
2514 up_write(&vol->mftbmp_lock);
2515 /*
2516 * We now have allocated and initialized the mft record. Calculate the
2517 * index of and the offset within the page cache page the record is in.
2518 */
2519 index = bit << vol->mft_record_size_bits >> PAGE_SHIFT;
2520 ofs = (bit << vol->mft_record_size_bits) & ~PAGE_MASK;
2521 /* Read, map, and pin the page containing the mft record. */
2522 page = ntfs_map_page(vol->mft_ino->i_mapping, index);
2523 if (IS_ERR(page)) {
2524 ntfs_error(vol->sb, "Failed to map page containing allocated "
2525 "mft record 0x%llx.", (long long)bit);
2526 err = PTR_ERR(page);
2527 goto undo_mftbmp_alloc;
2528 }
2529 lock_page(page);
2530 BUG_ON(!PageUptodate(page));
2531 ClearPageUptodate(page);
2532 m = (MFT_RECORD*)((u8*)page_address(page) + ofs);
2533 /* If we just formatted the mft record no need to do it again. */
2534 if (!record_formatted) {
2535 /* Sanity check that the mft record is really not in use. */
2536 if (ntfs_is_file_record(m->magic) &&
2537 (m->flags & MFT_RECORD_IN_USE)) {
2538 ntfs_error(vol->sb, "Mft record 0x%llx was marked "
2539 "free in mft bitmap but is marked "
2540 "used itself. Corrupt filesystem. "
2541 "Unmount and run chkdsk.",
2542 (long long)bit);
2543 err = -EIO;
2544 SetPageUptodate(page);
2545 unlock_page(page);
2546 ntfs_unmap_page(page);
2547 NVolSetErrors(vol);
2548 goto undo_mftbmp_alloc;
2549 }
2550 /*
2551 * We need to (re-)format the mft record, preserving the
2552 * sequence number if it is not zero as well as the update
2553 * sequence number if it is not zero or -1 (0xffff). This
2554 * means we do not need to care whether or not something went
2555 * wrong with the previous mft record.
2556 */
2557 seq_no = m->sequence_number;
2558 usn = *(le16*)((u8*)m + le16_to_cpu(m->usa_ofs));
2559 err = ntfs_mft_record_layout(vol, bit, m);
2560 if (unlikely(err)) {
2561 ntfs_error(vol->sb, "Failed to layout allocated mft "
2562 "record 0x%llx.", (long long)bit);
2563 SetPageUptodate(page);
2564 unlock_page(page);
2565 ntfs_unmap_page(page);
2566 goto undo_mftbmp_alloc;
2567 }
2568 if (seq_no)
2569 m->sequence_number = seq_no;
2570 if (usn && le16_to_cpu(usn) != 0xffff)
2571 *(le16*)((u8*)m + le16_to_cpu(m->usa_ofs)) = usn;
2572 }
2573 /* Set the mft record itself in use. */
2574 m->flags |= MFT_RECORD_IN_USE;
2575 if (S_ISDIR(mode))
2576 m->flags |= MFT_RECORD_IS_DIRECTORY;
2577 flush_dcache_page(page);
2578 SetPageUptodate(page);
2579 if (base_ni) {
2580 MFT_RECORD *m_tmp;
2581
2582 /*
2583 * Setup the base mft record in the extent mft record. This
2584 * completes initialization of the allocated extent mft record
2585 * and we can simply use it with map_extent_mft_record().
2586 */
2587 m->base_mft_record = MK_LE_MREF(base_ni->mft_no,
2588 base_ni->seq_no);
2589 /*
2590 * Allocate an extent inode structure for the new mft record,
2591 * attach it to the base inode @base_ni and map, pin, and lock
2592 * its, i.e. the allocated, mft record.
2593 */
2594 m_tmp = map_extent_mft_record(base_ni, bit, &ni);
2595 if (IS_ERR(m_tmp)) {
2596 ntfs_error(vol->sb, "Failed to map allocated extent "
2597 "mft record 0x%llx.", (long long)bit);
2598 err = PTR_ERR(m_tmp);
2599 /* Set the mft record itself not in use. */
2600 m->flags &= cpu_to_le16(
2601 ~le16_to_cpu(MFT_RECORD_IN_USE));
2602 flush_dcache_page(page);
2603 /* Make sure the mft record is written out to disk. */
2604 mark_ntfs_record_dirty(page, ofs);
2605 unlock_page(page);
2606 ntfs_unmap_page(page);
2607 goto undo_mftbmp_alloc;
2608 }
2609 BUG_ON(m != m_tmp);
2610 /*
2611 * Make sure the allocated mft record is written out to disk.
2612 * No need to set the inode dirty because the caller is going
2613 * to do that anyway after finishing with the new extent mft
2614 * record (e.g. at a minimum a new attribute will be added to
2615 * the mft record.
2616 */
2617 mark_ntfs_record_dirty(page, ofs);
2618 unlock_page(page);
2619 /*
2620 * Need to unmap the page since map_extent_mft_record() mapped
2621 * it as well so we have it mapped twice at the moment.
2622 */
2623 ntfs_unmap_page(page);
2624 } else {
2625 /*
2626 * Allocate a new VFS inode and set it up. NOTE: @vi->i_nlink
2627 * is set to 1 but the mft record->link_count is 0. The caller
2628 * needs to bear this in mind.
2629 */
2630 vi = new_inode(vol->sb);
2631 if (unlikely(!vi)) {
2632 err = -ENOMEM;
2633 /* Set the mft record itself not in use. */
2634 m->flags &= cpu_to_le16(
2635 ~le16_to_cpu(MFT_RECORD_IN_USE));
2636 flush_dcache_page(page);
2637 /* Make sure the mft record is written out to disk. */
2638 mark_ntfs_record_dirty(page, ofs);
2639 unlock_page(page);
2640 ntfs_unmap_page(page);
2641 goto undo_mftbmp_alloc;
2642 }
2643 vi->i_ino = bit;
2644
2645 /* The owner and group come from the ntfs volume. */
2646 vi->i_uid = vol->uid;
2647 vi->i_gid = vol->gid;
2648
2649 /* Initialize the ntfs specific part of @vi. */
2650 ntfs_init_big_inode(vi);
2651 ni = NTFS_I(vi);
2652 /*
2653 * Set the appropriate mode, attribute type, and name. For
2654 * directories, also setup the index values to the defaults.
2655 */
2656 if (S_ISDIR(mode)) {
2657 vi->i_mode = S_IFDIR | S_IRWXUGO;
2658 vi->i_mode &= ~vol->dmask;
2659
2660 NInoSetMstProtected(ni);
2661 ni->type = AT_INDEX_ALLOCATION;
2662 ni->name = I30;
2663 ni->name_len = 4;
2664
2665 ni->itype.index.block_size = 4096;
2666 ni->itype.index.block_size_bits = ntfs_ffs(4096) - 1;
2667 ni->itype.index.collation_rule = COLLATION_FILE_NAME;
2668 if (vol->cluster_size <= ni->itype.index.block_size) {
2669 ni->itype.index.vcn_size = vol->cluster_size;
2670 ni->itype.index.vcn_size_bits =
2671 vol->cluster_size_bits;
2672 } else {
2673 ni->itype.index.vcn_size = vol->sector_size;
2674 ni->itype.index.vcn_size_bits =
2675 vol->sector_size_bits;
2676 }
2677 } else {
2678 vi->i_mode = S_IFREG | S_IRWXUGO;
2679 vi->i_mode &= ~vol->fmask;
2680
2681 ni->type = AT_DATA;
2682 ni->name = NULL;
2683 ni->name_len = 0;
2684 }
2685 if (IS_RDONLY(vi))
2686 vi->i_mode &= ~S_IWUGO;
2687
2688 /* Set the inode times to the current time. */
2689 vi->i_atime = vi->i_mtime = vi->i_ctime =
2690 current_time(vi);
2691 /*
2692 * Set the file size to 0, the ntfs inode sizes are set to 0 by
2693 * the call to ntfs_init_big_inode() below.
2694 */
2695 vi->i_size = 0;
2696 vi->i_blocks = 0;
2697
2698 /* Set the sequence number. */
2699 vi->i_generation = ni->seq_no = le16_to_cpu(m->sequence_number);
2700 /*
2701 * Manually map, pin, and lock the mft record as we already
2702 * have its page mapped and it is very easy to do.
2703 */
2704 atomic_inc(&ni->count);
2705 mutex_lock(&ni->mrec_lock);
2706 ni->page = page;
2707 ni->page_ofs = ofs;
2708 /*
2709 * Make sure the allocated mft record is written out to disk.
2710 * NOTE: We do not set the ntfs inode dirty because this would
2711 * fail in ntfs_write_inode() because the inode does not have a
2712 * standard information attribute yet. Also, there is no need
2713 * to set the inode dirty because the caller is going to do
2714 * that anyway after finishing with the new mft record (e.g. at
2715 * a minimum some new attributes will be added to the mft
2716 * record.
2717 */
2718 mark_ntfs_record_dirty(page, ofs);
2719 unlock_page(page);
2720
2721 /* Add the inode to the inode hash for the superblock. */
2722 insert_inode_hash(vi);
2723
2724 /* Update the default mft allocation position. */
2725 vol->mft_data_pos = bit + 1;
2726 }
2727 /*
2728 * Return the opened, allocated inode of the allocated mft record as
2729 * well as the mapped, pinned, and locked mft record.
2730 */
2731 ntfs_debug("Returning opened, allocated %sinode 0x%llx.",
2732 base_ni ? "extent " : "", (long long)bit);
2733 *mrec = m;
2734 return ni;
2735undo_data_init:
2736 write_lock_irqsave(&mft_ni->size_lock, flags);
2737 mft_ni->initialized_size = old_data_initialized;
2738 i_size_write(vol->mft_ino, old_data_size);
2739 write_unlock_irqrestore(&mft_ni->size_lock, flags);
2740 goto undo_mftbmp_alloc_nolock;
2741undo_mftbmp_alloc:
2742 down_write(&vol->mftbmp_lock);
2743undo_mftbmp_alloc_nolock:
2744 if (ntfs_bitmap_clear_bit(vol->mftbmp_ino, bit)) {
2745 ntfs_error(vol->sb, "Failed to clear bit in mft bitmap.%s", es);
2746 NVolSetErrors(vol);
2747 }
2748 up_write(&vol->mftbmp_lock);
2749err_out:
2750 return ERR_PTR(err);
2751max_err_out:
2752 ntfs_warning(vol->sb, "Cannot allocate mft record because the maximum "
2753 "number of inodes (2^32) has already been reached.");
2754 up_write(&vol->mftbmp_lock);
2755 return ERR_PTR(-ENOSPC);
2756}
2757
2758/**
2759 * ntfs_extent_mft_record_free - free an extent mft record on an ntfs volume
2760 * @ni: ntfs inode of the mapped extent mft record to free
2761 * @m: mapped extent mft record of the ntfs inode @ni
2762 *
2763 * Free the mapped extent mft record @m of the extent ntfs inode @ni.
2764 *
2765 * Note that this function unmaps the mft record and closes and destroys @ni
2766 * internally and hence you cannot use either @ni nor @m any more after this
2767 * function returns success.
2768 *
2769 * On success return 0 and on error return -errno. @ni and @m are still valid
2770 * in this case and have not been freed.
2771 *
2772 * For some errors an error message is displayed and the success code 0 is
2773 * returned and the volume is then left dirty on umount. This makes sense in
2774 * case we could not rollback the changes that were already done since the
2775 * caller no longer wants to reference this mft record so it does not matter to
2776 * the caller if something is wrong with it as long as it is properly detached
2777 * from the base inode.
2778 */
2779int ntfs_extent_mft_record_free(ntfs_inode *ni, MFT_RECORD *m)
2780{
2781 unsigned long mft_no = ni->mft_no;
2782 ntfs_volume *vol = ni->vol;
2783 ntfs_inode *base_ni;
2784 ntfs_inode **extent_nis;
2785 int i, err;
2786 le16 old_seq_no;
2787 u16 seq_no;
2788
2789 BUG_ON(NInoAttr(ni));
2790 BUG_ON(ni->nr_extents != -1);
2791
2792 mutex_lock(&ni->extent_lock);
2793 base_ni = ni->ext.base_ntfs_ino;
2794 mutex_unlock(&ni->extent_lock);
2795
2796 BUG_ON(base_ni->nr_extents <= 0);
2797
2798 ntfs_debug("Entering for extent inode 0x%lx, base inode 0x%lx.\n",
2799 mft_no, base_ni->mft_no);
2800
2801 mutex_lock(&base_ni->extent_lock);
2802
2803 /* Make sure we are holding the only reference to the extent inode. */
2804 if (atomic_read(&ni->count) > 2) {
2805 ntfs_error(vol->sb, "Tried to free busy extent inode 0x%lx, "
2806 "not freeing.", base_ni->mft_no);
2807 mutex_unlock(&base_ni->extent_lock);
2808 return -EBUSY;
2809 }
2810
2811 /* Dissociate the ntfs inode from the base inode. */
2812 extent_nis = base_ni->ext.extent_ntfs_inos;
2813 err = -ENOENT;
2814 for (i = 0; i < base_ni->nr_extents; i++) {
2815 if (ni != extent_nis[i])
2816 continue;
2817 extent_nis += i;
2818 base_ni->nr_extents--;
2819 memmove(extent_nis, extent_nis + 1, (base_ni->nr_extents - i) *
2820 sizeof(ntfs_inode*));
2821 err = 0;
2822 break;
2823 }
2824
2825 mutex_unlock(&base_ni->extent_lock);
2826
2827 if (unlikely(err)) {
2828 ntfs_error(vol->sb, "Extent inode 0x%lx is not attached to "
2829 "its base inode 0x%lx.", mft_no,
2830 base_ni->mft_no);
2831 BUG();
2832 }
2833
2834 /*
2835 * The extent inode is no longer attached to the base inode so no one
2836 * can get a reference to it any more.
2837 */
2838
2839 /* Mark the mft record as not in use. */
2840 m->flags &= ~MFT_RECORD_IN_USE;
2841
2842 /* Increment the sequence number, skipping zero, if it is not zero. */
2843 old_seq_no = m->sequence_number;
2844 seq_no = le16_to_cpu(old_seq_no);
2845 if (seq_no == 0xffff)
2846 seq_no = 1;
2847 else if (seq_no)
2848 seq_no++;
2849 m->sequence_number = cpu_to_le16(seq_no);
2850
2851 /*
2852 * Set the ntfs inode dirty and write it out. We do not need to worry
2853 * about the base inode here since whatever caused the extent mft
2854 * record to be freed is guaranteed to do it already.
2855 */
2856 NInoSetDirty(ni);
2857 err = write_mft_record(ni, m, 0);
2858 if (unlikely(err)) {
2859 ntfs_error(vol->sb, "Failed to write mft record 0x%lx, not "
2860 "freeing.", mft_no);
2861 goto rollback;
2862 }
2863rollback_error:
2864 /* Unmap and throw away the now freed extent inode. */
2865 unmap_extent_mft_record(ni);
2866 ntfs_clear_extent_inode(ni);
2867
2868 /* Clear the bit in the $MFT/$BITMAP corresponding to this record. */
2869 down_write(&vol->mftbmp_lock);
2870 err = ntfs_bitmap_clear_bit(vol->mftbmp_ino, mft_no);
2871 up_write(&vol->mftbmp_lock);
2872 if (unlikely(err)) {
2873 /*
2874 * The extent inode is gone but we failed to deallocate it in
2875 * the mft bitmap. Just emit a warning and leave the volume
2876 * dirty on umount.
2877 */
2878 ntfs_error(vol->sb, "Failed to clear bit in mft bitmap.%s", es);
2879 NVolSetErrors(vol);
2880 }
2881 return 0;
2882rollback:
2883 /* Rollback what we did... */
2884 mutex_lock(&base_ni->extent_lock);
2885 extent_nis = base_ni->ext.extent_ntfs_inos;
2886 if (!(base_ni->nr_extents & 3)) {
2887 int new_size = (base_ni->nr_extents + 4) * sizeof(ntfs_inode*);
2888
2889 extent_nis = kmalloc(new_size, GFP_NOFS);
2890 if (unlikely(!extent_nis)) {
2891 ntfs_error(vol->sb, "Failed to allocate internal "
2892 "buffer during rollback.%s", es);
2893 mutex_unlock(&base_ni->extent_lock);
2894 NVolSetErrors(vol);
2895 goto rollback_error;
2896 }
2897 if (base_ni->nr_extents) {
2898 BUG_ON(!base_ni->ext.extent_ntfs_inos);
2899 memcpy(extent_nis, base_ni->ext.extent_ntfs_inos,
2900 new_size - 4 * sizeof(ntfs_inode*));
2901 kfree(base_ni->ext.extent_ntfs_inos);
2902 }
2903 base_ni->ext.extent_ntfs_inos = extent_nis;
2904 }
2905 m->flags |= MFT_RECORD_IN_USE;
2906 m->sequence_number = old_seq_no;
2907 extent_nis[base_ni->nr_extents++] = ni;
2908 mutex_unlock(&base_ni->extent_lock);
2909 mark_mft_record_dirty(ni);
2910 return err;
2911}
2912#endif /* NTFS_RW */