1 /** 2 * mft.c - NTFS kernel mft record operations. Part of the Linux-NTFS project. 3 * 4 * Copyright (c) 2001-2006 Anton Altaparmakov 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/swap.h> 25 26 #include "attrib.h" 27 #include "aops.h" 28 #include "bitmap.h" 29 #include "debug.h" 30 #include "dir.h" 31 #include "lcnalloc.h" 32 #include "malloc.h" 33 #include "mft.h" 34 #include "ntfs.h" 35 36 /** 37 * map_mft_record_page - map the page in which a specific mft record resides 38 * @ni: ntfs inode whose mft record page to map 39 * 40 * This maps the page in which the mft record of the ntfs inode @ni is situated 41 * and returns a pointer to the mft record within the mapped page. 42 * 43 * Return value needs to be checked with IS_ERR() and if that is true PTR_ERR() 44 * contains the negative error code returned. 45 */ 46 static inline MFT_RECORD *map_mft_record_page(ntfs_inode *ni) 47 { 48 loff_t i_size; 49 ntfs_volume *vol = ni->vol; 50 struct inode *mft_vi = vol->mft_ino; 51 struct page *page; 52 unsigned long index, end_index; 53 unsigned ofs; 54 55 BUG_ON(ni->page); 56 /* 57 * The index into the page cache and the offset within the page cache 58 * page of the wanted mft record. FIXME: We need to check for 59 * overflowing the unsigned long, but I don't think we would ever get 60 * here if the volume was that big... 61 */ 62 index = (u64)ni->mft_no << vol->mft_record_size_bits >> 63 PAGE_CACHE_SHIFT; 64 ofs = (ni->mft_no << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK; 65 66 i_size = i_size_read(mft_vi); 67 /* The maximum valid index into the page cache for $MFT's data. */ 68 end_index = i_size >> PAGE_CACHE_SHIFT; 69 70 /* If the wanted index is out of bounds the mft record doesn't exist. */ 71 if (unlikely(index >= end_index)) { 72 if (index > end_index || (i_size & ~PAGE_CACHE_MASK) < ofs + 73 vol->mft_record_size) { 74 page = ERR_PTR(-ENOENT); 75 ntfs_error(vol->sb, "Attemt to read mft record 0x%lx, " 76 "which is beyond the end of the mft. " 77 "This is probably a bug in the ntfs " 78 "driver.", ni->mft_no); 79 goto err_out; 80 } 81 } 82 /* Read, map, and pin the page. */ 83 page = ntfs_map_page(mft_vi->i_mapping, index); 84 if (likely(!IS_ERR(page))) { 85 /* Catch multi sector transfer fixup errors. */ 86 if (likely(ntfs_is_mft_recordp((le32*)(page_address(page) + 87 ofs)))) { 88 ni->page = page; 89 ni->page_ofs = ofs; 90 return page_address(page) + ofs; 91 } 92 ntfs_error(vol->sb, "Mft record 0x%lx is corrupt. " 93 "Run chkdsk.", ni->mft_no); 94 ntfs_unmap_page(page); 95 page = ERR_PTR(-EIO); 96 NVolSetErrors(vol); 97 } 98 err_out: 99 ni->page = NULL; 100 ni->page_ofs = 0; 101 return (void*)page; 102 } 103 104 /** 105 * map_mft_record - map, pin and lock an mft record 106 * @ni: ntfs inode whose MFT record to map 107 * 108 * First, take the mrec_lock mutex. We might now be sleeping, while waiting 109 * for the mutex if it was already locked by someone else. 110 * 111 * The page of the record is mapped using map_mft_record_page() before being 112 * returned to the caller. 113 * 114 * This in turn uses ntfs_map_page() to get the page containing the wanted mft 115 * record (it in turn calls read_cache_page() which reads it in from disk if 116 * necessary, increments the use count on the page so that it cannot disappear 117 * under us and returns a reference to the page cache page). 118 * 119 * If read_cache_page() invokes ntfs_readpage() to load the page from disk, it 120 * sets PG_locked and clears PG_uptodate on the page. Once I/O has completed 121 * and the post-read mst fixups on each mft record in the page have been 122 * performed, the page gets PG_uptodate set and PG_locked cleared (this is done 123 * in our asynchronous I/O completion handler end_buffer_read_mft_async()). 124 * ntfs_map_page() waits for PG_locked to become clear and checks if 125 * PG_uptodate is set and returns an error code if not. This provides 126 * sufficient protection against races when reading/using the page. 127 * 128 * However there is the write mapping to think about. Doing the above described 129 * checking here will be fine, because when initiating the write we will set 130 * PG_locked and clear PG_uptodate making sure nobody is touching the page 131 * contents. Doing the locking this way means that the commit to disk code in 132 * the page cache code paths is automatically sufficiently locked with us as 133 * we will not touch a page that has been locked or is not uptodate. The only 134 * locking problem then is them locking the page while we are accessing it. 135 * 136 * So that code will end up having to own the mrec_lock of all mft 137 * records/inodes present in the page before I/O can proceed. In that case we 138 * wouldn't need to bother with PG_locked and PG_uptodate as nobody will be 139 * accessing anything without owning the mrec_lock mutex. But we do need to 140 * use them because of the read_cache_page() invocation and the code becomes so 141 * much simpler this way that it is well worth it. 142 * 143 * The mft record is now ours and we return a pointer to it. You need to check 144 * the returned pointer with IS_ERR() and if that is true, PTR_ERR() will return 145 * the error code. 146 * 147 * NOTE: Caller is responsible for setting the mft record dirty before calling 148 * unmap_mft_record(). This is obviously only necessary if the caller really 149 * modified the mft record... 150 * Q: Do we want to recycle one of the VFS inode state bits instead? 151 * A: No, the inode ones mean we want to change the mft record, not we want to 152 * write it out. 153 */ 154 MFT_RECORD *map_mft_record(ntfs_inode *ni) 155 { 156 MFT_RECORD *m; 157 158 ntfs_debug("Entering for mft_no 0x%lx.", ni->mft_no); 159 160 /* Make sure the ntfs inode doesn't go away. */ 161 atomic_inc(&ni->count); 162 163 /* Serialize access to this mft record. */ 164 mutex_lock(&ni->mrec_lock); 165 166 m = map_mft_record_page(ni); 167 if (likely(!IS_ERR(m))) 168 return m; 169 170 mutex_unlock(&ni->mrec_lock); 171 atomic_dec(&ni->count); 172 ntfs_error(ni->vol->sb, "Failed with error code %lu.", -PTR_ERR(m)); 173 return m; 174 } 175 176 /** 177 * unmap_mft_record_page - unmap the page in which a specific mft record resides 178 * @ni: ntfs inode whose mft record page to unmap 179 * 180 * This unmaps the page in which the mft record of the ntfs inode @ni is 181 * situated and returns. This is a NOOP if highmem is not configured. 182 * 183 * The unmap happens via ntfs_unmap_page() which in turn decrements the use 184 * count on the page thus releasing it from the pinned state. 185 * 186 * We do not actually unmap the page from memory of course, as that will be 187 * done by the page cache code itself when memory pressure increases or 188 * whatever. 189 */ 190 static inline void unmap_mft_record_page(ntfs_inode *ni) 191 { 192 BUG_ON(!ni->page); 193 194 // TODO: If dirty, blah... 195 ntfs_unmap_page(ni->page); 196 ni->page = NULL; 197 ni->page_ofs = 0; 198 return; 199 } 200 201 /** 202 * unmap_mft_record - release a mapped mft record 203 * @ni: ntfs inode whose MFT record to unmap 204 * 205 * We release the page mapping and the mrec_lock mutex which unmaps the mft 206 * record and releases it for others to get hold of. We also release the ntfs 207 * inode by decrementing the ntfs inode reference count. 208 * 209 * NOTE: If caller has modified the mft record, it is imperative to set the mft 210 * record dirty BEFORE calling unmap_mft_record(). 211 */ 212 void unmap_mft_record(ntfs_inode *ni) 213 { 214 struct page *page = ni->page; 215 216 BUG_ON(!page); 217 218 ntfs_debug("Entering for mft_no 0x%lx.", ni->mft_no); 219 220 unmap_mft_record_page(ni); 221 mutex_unlock(&ni->mrec_lock); 222 atomic_dec(&ni->count); 223 /* 224 * If pure ntfs_inode, i.e. no vfs inode attached, we leave it to 225 * ntfs_clear_extent_inode() in the extent inode case, and to the 226 * caller in the non-extent, yet pure ntfs inode case, to do the actual 227 * tear down of all structures and freeing of all allocated memory. 228 */ 229 return; 230 } 231 232 /** 233 * map_extent_mft_record - load an extent inode and attach it to its base 234 * @base_ni: base ntfs inode 235 * @mref: mft reference of the extent inode to load 236 * @ntfs_ino: on successful return, pointer to the ntfs_inode structure 237 * 238 * Load the extent mft record @mref and attach it to its base inode @base_ni. 239 * Return the mapped extent mft record if IS_ERR(result) is false. Otherwise 240 * PTR_ERR(result) gives the negative error code. 241 * 242 * On successful return, @ntfs_ino contains a pointer to the ntfs_inode 243 * structure of the mapped extent inode. 244 */ 245 MFT_RECORD *map_extent_mft_record(ntfs_inode *base_ni, MFT_REF mref, 246 ntfs_inode **ntfs_ino) 247 { 248 MFT_RECORD *m; 249 ntfs_inode *ni = NULL; 250 ntfs_inode **extent_nis = NULL; 251 int i; 252 unsigned long mft_no = MREF(mref); 253 u16 seq_no = MSEQNO(mref); 254 bool destroy_ni = false; 255 256 ntfs_debug("Mapping extent mft record 0x%lx (base mft record 0x%lx).", 257 mft_no, base_ni->mft_no); 258 /* Make sure the base ntfs inode doesn't go away. */ 259 atomic_inc(&base_ni->count); 260 /* 261 * Check if this extent inode has already been added to the base inode, 262 * in which case just return it. If not found, add it to the base 263 * inode before returning it. 264 */ 265 mutex_lock(&base_ni->extent_lock); 266 if (base_ni->nr_extents > 0) { 267 extent_nis = base_ni->ext.extent_ntfs_inos; 268 for (i = 0; i < base_ni->nr_extents; i++) { 269 if (mft_no != extent_nis[i]->mft_no) 270 continue; 271 ni = extent_nis[i]; 272 /* Make sure the ntfs inode doesn't go away. */ 273 atomic_inc(&ni->count); 274 break; 275 } 276 } 277 if (likely(ni != NULL)) { 278 mutex_unlock(&base_ni->extent_lock); 279 atomic_dec(&base_ni->count); 280 /* We found the record; just have to map and return it. */ 281 m = map_mft_record(ni); 282 /* map_mft_record() has incremented this on success. */ 283 atomic_dec(&ni->count); 284 if (likely(!IS_ERR(m))) { 285 /* Verify the sequence number. */ 286 if (likely(le16_to_cpu(m->sequence_number) == seq_no)) { 287 ntfs_debug("Done 1."); 288 *ntfs_ino = ni; 289 return m; 290 } 291 unmap_mft_record(ni); 292 ntfs_error(base_ni->vol->sb, "Found stale extent mft " 293 "reference! Corrupt filesystem. " 294 "Run chkdsk."); 295 return ERR_PTR(-EIO); 296 } 297 map_err_out: 298 ntfs_error(base_ni->vol->sb, "Failed to map extent " 299 "mft record, error code %ld.", -PTR_ERR(m)); 300 return m; 301 } 302 /* Record wasn't there. Get a new ntfs inode and initialize it. */ 303 ni = ntfs_new_extent_inode(base_ni->vol->sb, mft_no); 304 if (unlikely(!ni)) { 305 mutex_unlock(&base_ni->extent_lock); 306 atomic_dec(&base_ni->count); 307 return ERR_PTR(-ENOMEM); 308 } 309 ni->vol = base_ni->vol; 310 ni->seq_no = seq_no; 311 ni->nr_extents = -1; 312 ni->ext.base_ntfs_ino = base_ni; 313 /* Now map the record. */ 314 m = map_mft_record(ni); 315 if (IS_ERR(m)) { 316 mutex_unlock(&base_ni->extent_lock); 317 atomic_dec(&base_ni->count); 318 ntfs_clear_extent_inode(ni); 319 goto map_err_out; 320 } 321 /* Verify the sequence number if it is present. */ 322 if (seq_no && (le16_to_cpu(m->sequence_number) != seq_no)) { 323 ntfs_error(base_ni->vol->sb, "Found stale extent mft " 324 "reference! Corrupt filesystem. Run chkdsk."); 325 destroy_ni = true; 326 m = ERR_PTR(-EIO); 327 goto unm_err_out; 328 } 329 /* Attach extent inode to base inode, reallocating memory if needed. */ 330 if (!(base_ni->nr_extents & 3)) { 331 ntfs_inode **tmp; 332 int new_size = (base_ni->nr_extents + 4) * sizeof(ntfs_inode *); 333 334 tmp = kmalloc(new_size, GFP_NOFS); 335 if (unlikely(!tmp)) { 336 ntfs_error(base_ni->vol->sb, "Failed to allocate " 337 "internal buffer."); 338 destroy_ni = true; 339 m = ERR_PTR(-ENOMEM); 340 goto unm_err_out; 341 } 342 if (base_ni->nr_extents) { 343 BUG_ON(!base_ni->ext.extent_ntfs_inos); 344 memcpy(tmp, base_ni->ext.extent_ntfs_inos, new_size - 345 4 * sizeof(ntfs_inode *)); 346 kfree(base_ni->ext.extent_ntfs_inos); 347 } 348 base_ni->ext.extent_ntfs_inos = tmp; 349 } 350 base_ni->ext.extent_ntfs_inos[base_ni->nr_extents++] = ni; 351 mutex_unlock(&base_ni->extent_lock); 352 atomic_dec(&base_ni->count); 353 ntfs_debug("Done 2."); 354 *ntfs_ino = ni; 355 return m; 356 unm_err_out: 357 unmap_mft_record(ni); 358 mutex_unlock(&base_ni->extent_lock); 359 atomic_dec(&base_ni->count); 360 /* 361 * If the extent inode was not attached to the base inode we need to 362 * release it or we will leak memory. 363 */ 364 if (destroy_ni) 365 ntfs_clear_extent_inode(ni); 366 return m; 367 } 368 369 #ifdef NTFS_RW 370 371 /** 372 * __mark_mft_record_dirty - set the mft record and the page containing it dirty 373 * @ni: ntfs inode describing the mapped mft record 374 * 375 * Internal function. Users should call mark_mft_record_dirty() instead. 376 * 377 * Set the mapped (extent) mft record of the (base or extent) ntfs inode @ni, 378 * as well as the page containing the mft record, dirty. Also, mark the base 379 * vfs inode dirty. This ensures that any changes to the mft record are 380 * written out to disk. 381 * 382 * NOTE: We only set I_DIRTY_SYNC and I_DIRTY_DATASYNC (and not I_DIRTY_PAGES) 383 * on the base vfs inode, because even though file data may have been modified, 384 * it is dirty in the inode meta data rather than the data page cache of the 385 * inode, and thus there are no data pages that need writing out. Therefore, a 386 * full mark_inode_dirty() is overkill. A mark_inode_dirty_sync(), on the 387 * other hand, is not sufficient, because I_DIRTY_DATASYNC needs to be set to 388 * ensure ->write_inode is called from generic_osync_inode() and this needs to 389 * happen or the file data would not necessarily hit the device synchronously, 390 * even though the vfs inode has the O_SYNC flag set. Also, I_DIRTY_DATASYNC 391 * simply "feels" better than just I_DIRTY_SYNC, since the file data has not 392 * actually hit the block device yet, which is not what I_DIRTY_SYNC on its own 393 * would suggest. 394 */ 395 void __mark_mft_record_dirty(ntfs_inode *ni) 396 { 397 ntfs_inode *base_ni; 398 399 ntfs_debug("Entering for inode 0x%lx.", ni->mft_no); 400 BUG_ON(NInoAttr(ni)); 401 mark_ntfs_record_dirty(ni->page, ni->page_ofs); 402 /* Determine the base vfs inode and mark it dirty, too. */ 403 mutex_lock(&ni->extent_lock); 404 if (likely(ni->nr_extents >= 0)) 405 base_ni = ni; 406 else 407 base_ni = ni->ext.base_ntfs_ino; 408 mutex_unlock(&ni->extent_lock); 409 __mark_inode_dirty(VFS_I(base_ni), I_DIRTY_SYNC | I_DIRTY_DATASYNC); 410 } 411 412 static const char *ntfs_please_email = "Please email " 413 "linux-ntfs-dev@lists.sourceforge.net and say that you saw " 414 "this message. Thank you."; 415 416 /** 417 * ntfs_sync_mft_mirror_umount - synchronise an mft record to the mft mirror 418 * @vol: ntfs volume on which the mft record to synchronize resides 419 * @mft_no: mft record number of mft record to synchronize 420 * @m: mapped, mst protected (extent) mft record to synchronize 421 * 422 * Write the mapped, mst protected (extent) mft record @m with mft record 423 * number @mft_no to the mft mirror ($MFTMirr) of the ntfs volume @vol, 424 * bypassing the page cache and the $MFTMirr inode itself. 425 * 426 * This function is only for use at umount time when the mft mirror inode has 427 * already been disposed off. We BUG() if we are called while the mft mirror 428 * inode is still attached to the volume. 429 * 430 * On success return 0. On error return -errno. 431 * 432 * NOTE: This function is not implemented yet as I am not convinced it can 433 * actually be triggered considering the sequence of commits we do in super.c:: 434 * ntfs_put_super(). But just in case we provide this place holder as the 435 * alternative would be either to BUG() or to get a NULL pointer dereference 436 * and Oops. 437 */ 438 static int ntfs_sync_mft_mirror_umount(ntfs_volume *vol, 439 const unsigned long mft_no, MFT_RECORD *m) 440 { 441 BUG_ON(vol->mftmirr_ino); 442 ntfs_error(vol->sb, "Umount time mft mirror syncing is not " 443 "implemented yet. %s", ntfs_please_email); 444 return -EOPNOTSUPP; 445 } 446 447 /** 448 * ntfs_sync_mft_mirror - synchronize an mft record to the mft mirror 449 * @vol: ntfs volume on which the mft record to synchronize resides 450 * @mft_no: mft record number of mft record to synchronize 451 * @m: mapped, mst protected (extent) mft record to synchronize 452 * @sync: if true, wait for i/o completion 453 * 454 * Write the mapped, mst protected (extent) mft record @m with mft record 455 * number @mft_no to the mft mirror ($MFTMirr) of the ntfs volume @vol. 456 * 457 * On success return 0. On error return -errno and set the volume errors flag 458 * in the ntfs volume @vol. 459 * 460 * NOTE: We always perform synchronous i/o and ignore the @sync parameter. 461 * 462 * TODO: If @sync is false, want to do truly asynchronous i/o, i.e. just 463 * schedule i/o via ->writepage or do it via kntfsd or whatever. 464 */ 465 int ntfs_sync_mft_mirror(ntfs_volume *vol, const unsigned long mft_no, 466 MFT_RECORD *m, int sync) 467 { 468 struct page *page; 469 unsigned int blocksize = vol->sb->s_blocksize; 470 int max_bhs = vol->mft_record_size / blocksize; 471 struct buffer_head *bhs[max_bhs]; 472 struct buffer_head *bh, *head; 473 u8 *kmirr; 474 runlist_element *rl; 475 unsigned int block_start, block_end, m_start, m_end, page_ofs; 476 int i_bhs, nr_bhs, err = 0; 477 unsigned char blocksize_bits = vol->sb->s_blocksize_bits; 478 479 ntfs_debug("Entering for inode 0x%lx.", mft_no); 480 BUG_ON(!max_bhs); 481 if (unlikely(!vol->mftmirr_ino)) { 482 /* This could happen during umount... */ 483 err = ntfs_sync_mft_mirror_umount(vol, mft_no, m); 484 if (likely(!err)) 485 return err; 486 goto err_out; 487 } 488 /* Get the page containing the mirror copy of the mft record @m. */ 489 page = ntfs_map_page(vol->mftmirr_ino->i_mapping, mft_no >> 490 (PAGE_CACHE_SHIFT - vol->mft_record_size_bits)); 491 if (IS_ERR(page)) { 492 ntfs_error(vol->sb, "Failed to map mft mirror page."); 493 err = PTR_ERR(page); 494 goto err_out; 495 } 496 lock_page(page); 497 BUG_ON(!PageUptodate(page)); 498 ClearPageUptodate(page); 499 /* Offset of the mft mirror record inside the page. */ 500 page_ofs = (mft_no << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK; 501 /* The address in the page of the mirror copy of the mft record @m. */ 502 kmirr = page_address(page) + page_ofs; 503 /* Copy the mst protected mft record to the mirror. */ 504 memcpy(kmirr, m, vol->mft_record_size); 505 /* Create uptodate buffers if not present. */ 506 if (unlikely(!page_has_buffers(page))) { 507 struct buffer_head *tail; 508 509 bh = head = alloc_page_buffers(page, blocksize, 1); 510 do { 511 set_buffer_uptodate(bh); 512 tail = bh; 513 bh = bh->b_this_page; 514 } while (bh); 515 tail->b_this_page = head; 516 attach_page_buffers(page, head); 517 } 518 bh = head = page_buffers(page); 519 BUG_ON(!bh); 520 rl = NULL; 521 nr_bhs = 0; 522 block_start = 0; 523 m_start = kmirr - (u8*)page_address(page); 524 m_end = m_start + vol->mft_record_size; 525 do { 526 block_end = block_start + blocksize; 527 /* If the buffer is outside the mft record, skip it. */ 528 if (block_end <= m_start) 529 continue; 530 if (unlikely(block_start >= m_end)) 531 break; 532 /* Need to map the buffer if it is not mapped already. */ 533 if (unlikely(!buffer_mapped(bh))) { 534 VCN vcn; 535 LCN lcn; 536 unsigned int vcn_ofs; 537 538 bh->b_bdev = vol->sb->s_bdev; 539 /* Obtain the vcn and offset of the current block. */ 540 vcn = ((VCN)mft_no << vol->mft_record_size_bits) + 541 (block_start - m_start); 542 vcn_ofs = vcn & vol->cluster_size_mask; 543 vcn >>= vol->cluster_size_bits; 544 if (!rl) { 545 down_read(&NTFS_I(vol->mftmirr_ino)-> 546 runlist.lock); 547 rl = NTFS_I(vol->mftmirr_ino)->runlist.rl; 548 /* 549 * $MFTMirr always has the whole of its runlist 550 * in memory. 551 */ 552 BUG_ON(!rl); 553 } 554 /* Seek to element containing target vcn. */ 555 while (rl->length && rl[1].vcn <= vcn) 556 rl++; 557 lcn = ntfs_rl_vcn_to_lcn(rl, vcn); 558 /* For $MFTMirr, only lcn >= 0 is a successful remap. */ 559 if (likely(lcn >= 0)) { 560 /* Setup buffer head to correct block. */ 561 bh->b_blocknr = ((lcn << 562 vol->cluster_size_bits) + 563 vcn_ofs) >> blocksize_bits; 564 set_buffer_mapped(bh); 565 } else { 566 bh->b_blocknr = -1; 567 ntfs_error(vol->sb, "Cannot write mft mirror " 568 "record 0x%lx because its " 569 "location on disk could not " 570 "be determined (error code " 571 "%lli).", mft_no, 572 (long long)lcn); 573 err = -EIO; 574 } 575 } 576 BUG_ON(!buffer_uptodate(bh)); 577 BUG_ON(!nr_bhs && (m_start != block_start)); 578 BUG_ON(nr_bhs >= max_bhs); 579 bhs[nr_bhs++] = bh; 580 BUG_ON((nr_bhs >= max_bhs) && (m_end != block_end)); 581 } while (block_start = block_end, (bh = bh->b_this_page) != head); 582 if (unlikely(rl)) 583 up_read(&NTFS_I(vol->mftmirr_ino)->runlist.lock); 584 if (likely(!err)) { 585 /* Lock buffers and start synchronous write i/o on them. */ 586 for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) { 587 struct buffer_head *tbh = bhs[i_bhs]; 588 589 if (!trylock_buffer(tbh)) 590 BUG(); 591 BUG_ON(!buffer_uptodate(tbh)); 592 clear_buffer_dirty(tbh); 593 get_bh(tbh); 594 tbh->b_end_io = end_buffer_write_sync; 595 submit_bh(WRITE, tbh); 596 } 597 /* Wait on i/o completion of buffers. */ 598 for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) { 599 struct buffer_head *tbh = bhs[i_bhs]; 600 601 wait_on_buffer(tbh); 602 if (unlikely(!buffer_uptodate(tbh))) { 603 err = -EIO; 604 /* 605 * Set the buffer uptodate so the page and 606 * buffer states do not become out of sync. 607 */ 608 set_buffer_uptodate(tbh); 609 } 610 } 611 } else /* if (unlikely(err)) */ { 612 /* Clean the buffers. */ 613 for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) 614 clear_buffer_dirty(bhs[i_bhs]); 615 } 616 /* Current state: all buffers are clean, unlocked, and uptodate. */ 617 /* Remove the mst protection fixups again. */ 618 post_write_mst_fixup((NTFS_RECORD*)kmirr); 619 flush_dcache_page(page); 620 SetPageUptodate(page); 621 unlock_page(page); 622 ntfs_unmap_page(page); 623 if (likely(!err)) { 624 ntfs_debug("Done."); 625 } else { 626 ntfs_error(vol->sb, "I/O error while writing mft mirror " 627 "record 0x%lx!", mft_no); 628 err_out: 629 ntfs_error(vol->sb, "Failed to synchronize $MFTMirr (error " 630 "code %i). Volume will be left marked dirty " 631 "on umount. Run ntfsfix on the partition " 632 "after umounting to correct this.", -err); 633 NVolSetErrors(vol); 634 } 635 return err; 636 } 637 638 /** 639 * write_mft_record_nolock - write out a mapped (extent) mft record 640 * @ni: ntfs inode describing the mapped (extent) mft record 641 * @m: mapped (extent) mft record to write 642 * @sync: if true, wait for i/o completion 643 * 644 * Write the mapped (extent) mft record @m described by the (regular or extent) 645 * ntfs inode @ni to backing store. If the mft record @m has a counterpart in 646 * the mft mirror, that is also updated. 647 * 648 * We only write the mft record if the ntfs inode @ni is dirty and the first 649 * buffer belonging to its mft record is dirty, too. We ignore the dirty state 650 * of subsequent buffers because we could have raced with 651 * fs/ntfs/aops.c::mark_ntfs_record_dirty(). 652 * 653 * On success, clean the mft record and return 0. On error, leave the mft 654 * record dirty and return -errno. 655 * 656 * NOTE: We always perform synchronous i/o and ignore the @sync parameter. 657 * However, if the mft record has a counterpart in the mft mirror and @sync is 658 * true, we write the mft record, wait for i/o completion, and only then write 659 * the mft mirror copy. This ensures that if the system crashes either the mft 660 * or the mft mirror will contain a self-consistent mft record @m. If @sync is 661 * false on the other hand, we start i/o on both and then wait for completion 662 * on them. This provides a speedup but no longer guarantees that you will end 663 * up with a self-consistent mft record in the case of a crash but if you asked 664 * for asynchronous writing you probably do not care about that anyway. 665 * 666 * TODO: If @sync is false, want to do truly asynchronous i/o, i.e. just 667 * schedule i/o via ->writepage or do it via kntfsd or whatever. 668 */ 669 int write_mft_record_nolock(ntfs_inode *ni, MFT_RECORD *m, int sync) 670 { 671 ntfs_volume *vol = ni->vol; 672 struct page *page = ni->page; 673 unsigned int blocksize = vol->sb->s_blocksize; 674 unsigned char blocksize_bits = vol->sb->s_blocksize_bits; 675 int max_bhs = vol->mft_record_size / blocksize; 676 struct buffer_head *bhs[max_bhs]; 677 struct buffer_head *bh, *head; 678 runlist_element *rl; 679 unsigned int block_start, block_end, m_start, m_end; 680 int i_bhs, nr_bhs, err = 0; 681 682 ntfs_debug("Entering for inode 0x%lx.", ni->mft_no); 683 BUG_ON(NInoAttr(ni)); 684 BUG_ON(!max_bhs); 685 BUG_ON(!PageLocked(page)); 686 /* 687 * If the ntfs_inode is clean no need to do anything. If it is dirty, 688 * mark it as clean now so that it can be redirtied later on if needed. 689 * There is no danger of races since the caller is holding the locks 690 * for the mft record @m and the page it is in. 691 */ 692 if (!NInoTestClearDirty(ni)) 693 goto done; 694 bh = head = page_buffers(page); 695 BUG_ON(!bh); 696 rl = NULL; 697 nr_bhs = 0; 698 block_start = 0; 699 m_start = ni->page_ofs; 700 m_end = m_start + vol->mft_record_size; 701 do { 702 block_end = block_start + blocksize; 703 /* If the buffer is outside the mft record, skip it. */ 704 if (block_end <= m_start) 705 continue; 706 if (unlikely(block_start >= m_end)) 707 break; 708 /* 709 * If this block is not the first one in the record, we ignore 710 * the buffer's dirty state because we could have raced with a 711 * parallel mark_ntfs_record_dirty(). 712 */ 713 if (block_start == m_start) { 714 /* This block is the first one in the record. */ 715 if (!buffer_dirty(bh)) { 716 BUG_ON(nr_bhs); 717 /* Clean records are not written out. */ 718 break; 719 } 720 } 721 /* Need to map the buffer if it is not mapped already. */ 722 if (unlikely(!buffer_mapped(bh))) { 723 VCN vcn; 724 LCN lcn; 725 unsigned int vcn_ofs; 726 727 bh->b_bdev = vol->sb->s_bdev; 728 /* Obtain the vcn and offset of the current block. */ 729 vcn = ((VCN)ni->mft_no << vol->mft_record_size_bits) + 730 (block_start - m_start); 731 vcn_ofs = vcn & vol->cluster_size_mask; 732 vcn >>= vol->cluster_size_bits; 733 if (!rl) { 734 down_read(&NTFS_I(vol->mft_ino)->runlist.lock); 735 rl = NTFS_I(vol->mft_ino)->runlist.rl; 736 BUG_ON(!rl); 737 } 738 /* Seek to element containing target vcn. */ 739 while (rl->length && rl[1].vcn <= vcn) 740 rl++; 741 lcn = ntfs_rl_vcn_to_lcn(rl, vcn); 742 /* For $MFT, only lcn >= 0 is a successful remap. */ 743 if (likely(lcn >= 0)) { 744 /* Setup buffer head to correct block. */ 745 bh->b_blocknr = ((lcn << 746 vol->cluster_size_bits) + 747 vcn_ofs) >> blocksize_bits; 748 set_buffer_mapped(bh); 749 } else { 750 bh->b_blocknr = -1; 751 ntfs_error(vol->sb, "Cannot write mft record " 752 "0x%lx because its location " 753 "on disk could not be " 754 "determined (error code %lli).", 755 ni->mft_no, (long long)lcn); 756 err = -EIO; 757 } 758 } 759 BUG_ON(!buffer_uptodate(bh)); 760 BUG_ON(!nr_bhs && (m_start != block_start)); 761 BUG_ON(nr_bhs >= max_bhs); 762 bhs[nr_bhs++] = bh; 763 BUG_ON((nr_bhs >= max_bhs) && (m_end != block_end)); 764 } while (block_start = block_end, (bh = bh->b_this_page) != head); 765 if (unlikely(rl)) 766 up_read(&NTFS_I(vol->mft_ino)->runlist.lock); 767 if (!nr_bhs) 768 goto done; 769 if (unlikely(err)) 770 goto cleanup_out; 771 /* Apply the mst protection fixups. */ 772 err = pre_write_mst_fixup((NTFS_RECORD*)m, vol->mft_record_size); 773 if (err) { 774 ntfs_error(vol->sb, "Failed to apply mst fixups!"); 775 goto cleanup_out; 776 } 777 flush_dcache_mft_record_page(ni); 778 /* Lock buffers and start synchronous write i/o on them. */ 779 for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) { 780 struct buffer_head *tbh = bhs[i_bhs]; 781 782 if (!trylock_buffer(tbh)) 783 BUG(); 784 BUG_ON(!buffer_uptodate(tbh)); 785 clear_buffer_dirty(tbh); 786 get_bh(tbh); 787 tbh->b_end_io = end_buffer_write_sync; 788 submit_bh(WRITE, tbh); 789 } 790 /* Synchronize the mft mirror now if not @sync. */ 791 if (!sync && ni->mft_no < vol->mftmirr_size) 792 ntfs_sync_mft_mirror(vol, ni->mft_no, m, sync); 793 /* Wait on i/o completion of buffers. */ 794 for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) { 795 struct buffer_head *tbh = bhs[i_bhs]; 796 797 wait_on_buffer(tbh); 798 if (unlikely(!buffer_uptodate(tbh))) { 799 err = -EIO; 800 /* 801 * Set the buffer uptodate so the page and buffer 802 * states do not become out of sync. 803 */ 804 if (PageUptodate(page)) 805 set_buffer_uptodate(tbh); 806 } 807 } 808 /* If @sync, now synchronize the mft mirror. */ 809 if (sync && ni->mft_no < vol->mftmirr_size) 810 ntfs_sync_mft_mirror(vol, ni->mft_no, m, sync); 811 /* Remove the mst protection fixups again. */ 812 post_write_mst_fixup((NTFS_RECORD*)m); 813 flush_dcache_mft_record_page(ni); 814 if (unlikely(err)) { 815 /* I/O error during writing. This is really bad! */ 816 ntfs_error(vol->sb, "I/O error while writing mft record " 817 "0x%lx! Marking base inode as bad. You " 818 "should unmount the volume and run chkdsk.", 819 ni->mft_no); 820 goto err_out; 821 } 822 done: 823 ntfs_debug("Done."); 824 return 0; 825 cleanup_out: 826 /* Clean the buffers. */ 827 for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) 828 clear_buffer_dirty(bhs[i_bhs]); 829 err_out: 830 /* 831 * Current state: all buffers are clean, unlocked, and uptodate. 832 * The caller should mark the base inode as bad so that no more i/o 833 * happens. ->clear_inode() will still be invoked so all extent inodes 834 * and other allocated memory will be freed. 835 */ 836 if (err == -ENOMEM) { 837 ntfs_error(vol->sb, "Not enough memory to write mft record. " 838 "Redirtying so the write is retried later."); 839 mark_mft_record_dirty(ni); 840 err = 0; 841 } else 842 NVolSetErrors(vol); 843 return err; 844 } 845 846 /** 847 * ntfs_may_write_mft_record - check if an mft record may be written out 848 * @vol: [IN] ntfs volume on which the mft record to check resides 849 * @mft_no: [IN] mft record number of the mft record to check 850 * @m: [IN] mapped mft record to check 851 * @locked_ni: [OUT] caller has to unlock this ntfs inode if one is returned 852 * 853 * Check if the mapped (base or extent) mft record @m with mft record number 854 * @mft_no belonging to the ntfs volume @vol may be written out. If necessary 855 * and possible the ntfs inode of the mft record is locked and the base vfs 856 * inode is pinned. The locked ntfs inode is then returned in @locked_ni. The 857 * caller is responsible for unlocking the ntfs inode and unpinning the base 858 * vfs inode. 859 * 860 * Return 'true' if the mft record may be written out and 'false' if not. 861 * 862 * The caller has locked the page and cleared the uptodate flag on it which 863 * means that we can safely write out any dirty mft records that do not have 864 * their inodes in icache as determined by ilookup5() as anyone 865 * opening/creating such an inode would block when attempting to map the mft 866 * record in read_cache_page() until we are finished with the write out. 867 * 868 * Here is a description of the tests we perform: 869 * 870 * If the inode is found in icache we know the mft record must be a base mft 871 * record. If it is dirty, we do not write it and return 'false' as the vfs 872 * inode write paths will result in the access times being updated which would 873 * cause the base mft record to be redirtied and written out again. (We know 874 * the access time update will modify the base mft record because Windows 875 * chkdsk complains if the standard information attribute is not in the base 876 * mft record.) 877 * 878 * If the inode is in icache and not dirty, we attempt to lock the mft record 879 * and if we find the lock was already taken, it is not safe to write the mft 880 * record and we return 'false'. 881 * 882 * If we manage to obtain the lock we have exclusive access to the mft record, 883 * which also allows us safe writeout of the mft record. We then set 884 * @locked_ni to the locked ntfs inode and return 'true'. 885 * 886 * Note we cannot just lock the mft record and sleep while waiting for the lock 887 * because this would deadlock due to lock reversal (normally the mft record is 888 * locked before the page is locked but we already have the page locked here 889 * when we try to lock the mft record). 890 * 891 * If the inode is not in icache we need to perform further checks. 892 * 893 * If the mft record is not a FILE record or it is a base mft record, we can 894 * safely write it and return 'true'. 895 * 896 * We now know the mft record is an extent mft record. We check if the inode 897 * corresponding to its base mft record is in icache and obtain a reference to 898 * it if it is. If it is not, we can safely write it and return 'true'. 899 * 900 * We now have the base inode for the extent mft record. We check if it has an 901 * ntfs inode for the extent mft record attached and if not it is safe to write 902 * the extent mft record and we return 'true'. 903 * 904 * The ntfs inode for the extent mft record is attached to the base inode so we 905 * attempt to lock the extent mft record and if we find the lock was already 906 * taken, it is not safe to write the extent mft record and we return 'false'. 907 * 908 * If we manage to obtain the lock we have exclusive access to the extent mft 909 * record, which also allows us safe writeout of the extent mft record. We 910 * set the ntfs inode of the extent mft record clean and then set @locked_ni to 911 * the now locked ntfs inode and return 'true'. 912 * 913 * Note, the reason for actually writing dirty mft records here and not just 914 * relying on the vfs inode dirty code paths is that we can have mft records 915 * modified without them ever having actual inodes in memory. Also we can have 916 * dirty mft records with clean ntfs inodes in memory. None of the described 917 * cases would result in the dirty mft records being written out if we only 918 * relied on the vfs inode dirty code paths. And these cases can really occur 919 * during allocation of new mft records and in particular when the 920 * initialized_size of the $MFT/$DATA attribute is extended and the new space 921 * is initialized using ntfs_mft_record_format(). The clean inode can then 922 * appear if the mft record is reused for a new inode before it got written 923 * out. 924 */ 925 bool ntfs_may_write_mft_record(ntfs_volume *vol, const unsigned long mft_no, 926 const MFT_RECORD *m, ntfs_inode **locked_ni) 927 { 928 struct super_block *sb = vol->sb; 929 struct inode *mft_vi = vol->mft_ino; 930 struct inode *vi; 931 ntfs_inode *ni, *eni, **extent_nis; 932 int i; 933 ntfs_attr na; 934 935 ntfs_debug("Entering for inode 0x%lx.", mft_no); 936 /* 937 * Normally we do not return a locked inode so set @locked_ni to NULL. 938 */ 939 BUG_ON(!locked_ni); 940 *locked_ni = NULL; 941 /* 942 * Check if the inode corresponding to this mft record is in the VFS 943 * inode cache and obtain a reference to it if it is. 944 */ 945 ntfs_debug("Looking for inode 0x%lx in icache.", mft_no); 946 na.mft_no = mft_no; 947 na.name = NULL; 948 na.name_len = 0; 949 na.type = AT_UNUSED; 950 /* 951 * Optimize inode 0, i.e. $MFT itself, since we have it in memory and 952 * we get here for it rather often. 953 */ 954 if (!mft_no) { 955 /* Balance the below iput(). */ 956 vi = igrab(mft_vi); 957 BUG_ON(vi != mft_vi); 958 } else { 959 /* 960 * Have to use ilookup5_nowait() since ilookup5() waits for the 961 * inode lock which causes ntfs to deadlock when a concurrent 962 * inode write via the inode dirty code paths and the page 963 * dirty code path of the inode dirty code path when writing 964 * $MFT occurs. 965 */ 966 vi = ilookup5_nowait(sb, mft_no, (test_t)ntfs_test_inode, &na); 967 } 968 if (vi) { 969 ntfs_debug("Base inode 0x%lx is in icache.", mft_no); 970 /* The inode is in icache. */ 971 ni = NTFS_I(vi); 972 /* Take a reference to the ntfs inode. */ 973 atomic_inc(&ni->count); 974 /* If the inode is dirty, do not write this record. */ 975 if (NInoDirty(ni)) { 976 ntfs_debug("Inode 0x%lx is dirty, do not write it.", 977 mft_no); 978 atomic_dec(&ni->count); 979 iput(vi); 980 return false; 981 } 982 ntfs_debug("Inode 0x%lx is not dirty.", mft_no); 983 /* The inode is not dirty, try to take the mft record lock. */ 984 if (unlikely(!mutex_trylock(&ni->mrec_lock))) { 985 ntfs_debug("Mft record 0x%lx is already locked, do " 986 "not write it.", mft_no); 987 atomic_dec(&ni->count); 988 iput(vi); 989 return false; 990 } 991 ntfs_debug("Managed to lock mft record 0x%lx, write it.", 992 mft_no); 993 /* 994 * The write has to occur while we hold the mft record lock so 995 * return the locked ntfs inode. 996 */ 997 *locked_ni = ni; 998 return true; 999 } 1000 ntfs_debug("Inode 0x%lx is not in icache.", mft_no); 1001 /* The inode is not in icache. */ 1002 /* Write the record if it is not a mft record (type "FILE"). */ 1003 if (!ntfs_is_mft_record(m->magic)) { 1004 ntfs_debug("Mft record 0x%lx is not a FILE record, write it.", 1005 mft_no); 1006 return true; 1007 } 1008 /* Write the mft record if it is a base inode. */ 1009 if (!m->base_mft_record) { 1010 ntfs_debug("Mft record 0x%lx is a base record, write it.", 1011 mft_no); 1012 return true; 1013 } 1014 /* 1015 * This is an extent mft record. Check if the inode corresponding to 1016 * its base mft record is in icache and obtain a reference to it if it 1017 * is. 1018 */ 1019 na.mft_no = MREF_LE(m->base_mft_record); 1020 ntfs_debug("Mft record 0x%lx is an extent record. Looking for base " 1021 "inode 0x%lx in icache.", mft_no, na.mft_no); 1022 if (!na.mft_no) { 1023 /* Balance the below iput(). */ 1024 vi = igrab(mft_vi); 1025 BUG_ON(vi != mft_vi); 1026 } else 1027 vi = ilookup5_nowait(sb, na.mft_no, (test_t)ntfs_test_inode, 1028 &na); 1029 if (!vi) { 1030 /* 1031 * The base inode is not in icache, write this extent mft 1032 * record. 1033 */ 1034 ntfs_debug("Base inode 0x%lx is not in icache, write the " 1035 "extent record.", na.mft_no); 1036 return true; 1037 } 1038 ntfs_debug("Base inode 0x%lx is in icache.", na.mft_no); 1039 /* 1040 * The base inode is in icache. Check if it has the extent inode 1041 * corresponding to this extent mft record attached. 1042 */ 1043 ni = NTFS_I(vi); 1044 mutex_lock(&ni->extent_lock); 1045 if (ni->nr_extents <= 0) { 1046 /* 1047 * The base inode has no attached extent inodes, write this 1048 * extent mft record. 1049 */ 1050 mutex_unlock(&ni->extent_lock); 1051 iput(vi); 1052 ntfs_debug("Base inode 0x%lx has no attached extent inodes, " 1053 "write the extent record.", na.mft_no); 1054 return true; 1055 } 1056 /* Iterate over the attached extent inodes. */ 1057 extent_nis = ni->ext.extent_ntfs_inos; 1058 for (eni = NULL, i = 0; i < ni->nr_extents; ++i) { 1059 if (mft_no == extent_nis[i]->mft_no) { 1060 /* 1061 * Found the extent inode corresponding to this extent 1062 * mft record. 1063 */ 1064 eni = extent_nis[i]; 1065 break; 1066 } 1067 } 1068 /* 1069 * If the extent inode was not attached to the base inode, write this 1070 * extent mft record. 1071 */ 1072 if (!eni) { 1073 mutex_unlock(&ni->extent_lock); 1074 iput(vi); 1075 ntfs_debug("Extent inode 0x%lx is not attached to its base " 1076 "inode 0x%lx, write the extent record.", 1077 mft_no, na.mft_no); 1078 return true; 1079 } 1080 ntfs_debug("Extent inode 0x%lx is attached to its base inode 0x%lx.", 1081 mft_no, na.mft_no); 1082 /* Take a reference to the extent ntfs inode. */ 1083 atomic_inc(&eni->count); 1084 mutex_unlock(&ni->extent_lock); 1085 /* 1086 * Found the extent inode coresponding to this extent mft record. 1087 * Try to take the mft record lock. 1088 */ 1089 if (unlikely(!mutex_trylock(&eni->mrec_lock))) { 1090 atomic_dec(&eni->count); 1091 iput(vi); 1092 ntfs_debug("Extent mft record 0x%lx is already locked, do " 1093 "not write it.", mft_no); 1094 return false; 1095 } 1096 ntfs_debug("Managed to lock extent mft record 0x%lx, write it.", 1097 mft_no); 1098 if (NInoTestClearDirty(eni)) 1099 ntfs_debug("Extent inode 0x%lx is dirty, marking it clean.", 1100 mft_no); 1101 /* 1102 * The write has to occur while we hold the mft record lock so return 1103 * the locked extent ntfs inode. 1104 */ 1105 *locked_ni = eni; 1106 return true; 1107 } 1108 1109 static const char *es = " Leaving inconsistent metadata. Unmount and run " 1110 "chkdsk."; 1111 1112 /** 1113 * ntfs_mft_bitmap_find_and_alloc_free_rec_nolock - see name 1114 * @vol: volume on which to search for a free mft record 1115 * @base_ni: open base inode if allocating an extent mft record or NULL 1116 * 1117 * Search for a free mft record in the mft bitmap attribute on the ntfs volume 1118 * @vol. 1119 * 1120 * If @base_ni is NULL start the search at the default allocator position. 1121 * 1122 * If @base_ni is not NULL start the search at the mft record after the base 1123 * mft record @base_ni. 1124 * 1125 * Return the free mft record on success and -errno on error. An error code of 1126 * -ENOSPC means that there are no free mft records in the currently 1127 * initialized mft bitmap. 1128 * 1129 * Locking: Caller must hold vol->mftbmp_lock for writing. 1130 */ 1131 static int ntfs_mft_bitmap_find_and_alloc_free_rec_nolock(ntfs_volume *vol, 1132 ntfs_inode *base_ni) 1133 { 1134 s64 pass_end, ll, data_pos, pass_start, ofs, bit; 1135 unsigned long flags; 1136 struct address_space *mftbmp_mapping; 1137 u8 *buf, *byte; 1138 struct page *page; 1139 unsigned int page_ofs, size; 1140 u8 pass, b; 1141 1142 ntfs_debug("Searching for free mft record in the currently " 1143 "initialized mft bitmap."); 1144 mftbmp_mapping = vol->mftbmp_ino->i_mapping; 1145 /* 1146 * Set the end of the pass making sure we do not overflow the mft 1147 * bitmap. 1148 */ 1149 read_lock_irqsave(&NTFS_I(vol->mft_ino)->size_lock, flags); 1150 pass_end = NTFS_I(vol->mft_ino)->allocated_size >> 1151 vol->mft_record_size_bits; 1152 read_unlock_irqrestore(&NTFS_I(vol->mft_ino)->size_lock, flags); 1153 read_lock_irqsave(&NTFS_I(vol->mftbmp_ino)->size_lock, flags); 1154 ll = NTFS_I(vol->mftbmp_ino)->initialized_size << 3; 1155 read_unlock_irqrestore(&NTFS_I(vol->mftbmp_ino)->size_lock, flags); 1156 if (pass_end > ll) 1157 pass_end = ll; 1158 pass = 1; 1159 if (!base_ni) 1160 data_pos = vol->mft_data_pos; 1161 else 1162 data_pos = base_ni->mft_no + 1; 1163 if (data_pos < 24) 1164 data_pos = 24; 1165 if (data_pos >= pass_end) { 1166 data_pos = 24; 1167 pass = 2; 1168 /* This happens on a freshly formatted volume. */ 1169 if (data_pos >= pass_end) 1170 return -ENOSPC; 1171 } 1172 pass_start = data_pos; 1173 ntfs_debug("Starting bitmap search: pass %u, pass_start 0x%llx, " 1174 "pass_end 0x%llx, data_pos 0x%llx.", pass, 1175 (long long)pass_start, (long long)pass_end, 1176 (long long)data_pos); 1177 /* Loop until a free mft record is found. */ 1178 for (; pass <= 2;) { 1179 /* Cap size to pass_end. */ 1180 ofs = data_pos >> 3; 1181 page_ofs = ofs & ~PAGE_CACHE_MASK; 1182 size = PAGE_CACHE_SIZE - page_ofs; 1183 ll = ((pass_end + 7) >> 3) - ofs; 1184 if (size > ll) 1185 size = ll; 1186 size <<= 3; 1187 /* 1188 * If we are still within the active pass, search the next page 1189 * for a zero bit. 1190 */ 1191 if (size) { 1192 page = ntfs_map_page(mftbmp_mapping, 1193 ofs >> PAGE_CACHE_SHIFT); 1194 if (IS_ERR(page)) { 1195 ntfs_error(vol->sb, "Failed to read mft " 1196 "bitmap, aborting."); 1197 return PTR_ERR(page); 1198 } 1199 buf = (u8*)page_address(page) + page_ofs; 1200 bit = data_pos & 7; 1201 data_pos &= ~7ull; 1202 ntfs_debug("Before inner for loop: size 0x%x, " 1203 "data_pos 0x%llx, bit 0x%llx", size, 1204 (long long)data_pos, (long long)bit); 1205 for (; bit < size && data_pos + bit < pass_end; 1206 bit &= ~7ull, bit += 8) { 1207 byte = buf + (bit >> 3); 1208 if (*byte == 0xff) 1209 continue; 1210 b = ffz((unsigned long)*byte); 1211 if (b < 8 && b >= (bit & 7)) { 1212 ll = data_pos + (bit & ~7ull) + b; 1213 if (unlikely(ll > (1ll << 32))) { 1214 ntfs_unmap_page(page); 1215 return -ENOSPC; 1216 } 1217 *byte |= 1 << b; 1218 flush_dcache_page(page); 1219 set_page_dirty(page); 1220 ntfs_unmap_page(page); 1221 ntfs_debug("Done. (Found and " 1222 "allocated mft record " 1223 "0x%llx.)", 1224 (long long)ll); 1225 return ll; 1226 } 1227 } 1228 ntfs_debug("After inner for loop: size 0x%x, " 1229 "data_pos 0x%llx, bit 0x%llx", size, 1230 (long long)data_pos, (long long)bit); 1231 data_pos += size; 1232 ntfs_unmap_page(page); 1233 /* 1234 * If the end of the pass has not been reached yet, 1235 * continue searching the mft bitmap for a zero bit. 1236 */ 1237 if (data_pos < pass_end) 1238 continue; 1239 } 1240 /* Do the next pass. */ 1241 if (++pass == 2) { 1242 /* 1243 * Starting the second pass, in which we scan the first 1244 * part of the zone which we omitted earlier. 1245 */ 1246 pass_end = pass_start; 1247 data_pos = pass_start = 24; 1248 ntfs_debug("pass %i, pass_start 0x%llx, pass_end " 1249 "0x%llx.", pass, (long long)pass_start, 1250 (long long)pass_end); 1251 if (data_pos >= pass_end) 1252 break; 1253 } 1254 } 1255 /* No free mft records in currently initialized mft bitmap. */ 1256 ntfs_debug("Done. (No free mft records left in currently initialized " 1257 "mft bitmap.)"); 1258 return -ENOSPC; 1259 } 1260 1261 /** 1262 * ntfs_mft_bitmap_extend_allocation_nolock - extend mft bitmap by a cluster 1263 * @vol: volume on which to extend the mft bitmap attribute 1264 * 1265 * Extend the mft bitmap attribute on the ntfs volume @vol by one cluster. 1266 * 1267 * Note: Only changes allocated_size, i.e. does not touch initialized_size or 1268 * data_size. 1269 * 1270 * Return 0 on success and -errno on error. 1271 * 1272 * Locking: - Caller must hold vol->mftbmp_lock for writing. 1273 * - This function takes NTFS_I(vol->mftbmp_ino)->runlist.lock for 1274 * writing and releases it before returning. 1275 * - This function takes vol->lcnbmp_lock for writing and releases it 1276 * before returning. 1277 */ 1278 static int ntfs_mft_bitmap_extend_allocation_nolock(ntfs_volume *vol) 1279 { 1280 LCN lcn; 1281 s64 ll; 1282 unsigned long flags; 1283 struct page *page; 1284 ntfs_inode *mft_ni, *mftbmp_ni; 1285 runlist_element *rl, *rl2 = NULL; 1286 ntfs_attr_search_ctx *ctx = NULL; 1287 MFT_RECORD *mrec; 1288 ATTR_RECORD *a = NULL; 1289 int ret, mp_size; 1290 u32 old_alen = 0; 1291 u8 *b, tb; 1292 struct { 1293 u8 added_cluster:1; 1294 u8 added_run:1; 1295 u8 mp_rebuilt:1; 1296 } status = { 0, 0, 0 }; 1297 1298 ntfs_debug("Extending mft bitmap allocation."); 1299 mft_ni = NTFS_I(vol->mft_ino); 1300 mftbmp_ni = NTFS_I(vol->mftbmp_ino); 1301 /* 1302 * Determine the last lcn of the mft bitmap. The allocated size of the 1303 * mft bitmap cannot be zero so we are ok to do this. 1304 */ 1305 down_write(&mftbmp_ni->runlist.lock); 1306 read_lock_irqsave(&mftbmp_ni->size_lock, flags); 1307 ll = mftbmp_ni->allocated_size; 1308 read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 1309 rl = ntfs_attr_find_vcn_nolock(mftbmp_ni, 1310 (ll - 1) >> vol->cluster_size_bits, NULL); 1311 if (unlikely(IS_ERR(rl) || !rl->length || rl->lcn < 0)) { 1312 up_write(&mftbmp_ni->runlist.lock); 1313 ntfs_error(vol->sb, "Failed to determine last allocated " 1314 "cluster of mft bitmap attribute."); 1315 if (!IS_ERR(rl)) 1316 ret = -EIO; 1317 else 1318 ret = PTR_ERR(rl); 1319 return ret; 1320 } 1321 lcn = rl->lcn + rl->length; 1322 ntfs_debug("Last lcn of mft bitmap attribute is 0x%llx.", 1323 (long long)lcn); 1324 /* 1325 * Attempt to get the cluster following the last allocated cluster by 1326 * hand as it may be in the MFT zone so the allocator would not give it 1327 * to us. 1328 */ 1329 ll = lcn >> 3; 1330 page = ntfs_map_page(vol->lcnbmp_ino->i_mapping, 1331 ll >> PAGE_CACHE_SHIFT); 1332 if (IS_ERR(page)) { 1333 up_write(&mftbmp_ni->runlist.lock); 1334 ntfs_error(vol->sb, "Failed to read from lcn bitmap."); 1335 return PTR_ERR(page); 1336 } 1337 b = (u8*)page_address(page) + (ll & ~PAGE_CACHE_MASK); 1338 tb = 1 << (lcn & 7ull); 1339 down_write(&vol->lcnbmp_lock); 1340 if (*b != 0xff && !(*b & tb)) { 1341 /* Next cluster is free, allocate it. */ 1342 *b |= tb; 1343 flush_dcache_page(page); 1344 set_page_dirty(page); 1345 up_write(&vol->lcnbmp_lock); 1346 ntfs_unmap_page(page); 1347 /* Update the mft bitmap runlist. */ 1348 rl->length++; 1349 rl[1].vcn++; 1350 status.added_cluster = 1; 1351 ntfs_debug("Appending one cluster to mft bitmap."); 1352 } else { 1353 up_write(&vol->lcnbmp_lock); 1354 ntfs_unmap_page(page); 1355 /* Allocate a cluster from the DATA_ZONE. */ 1356 rl2 = ntfs_cluster_alloc(vol, rl[1].vcn, 1, lcn, DATA_ZONE, 1357 true); 1358 if (IS_ERR(rl2)) { 1359 up_write(&mftbmp_ni->runlist.lock); 1360 ntfs_error(vol->sb, "Failed to allocate a cluster for " 1361 "the mft bitmap."); 1362 return PTR_ERR(rl2); 1363 } 1364 rl = ntfs_runlists_merge(mftbmp_ni->runlist.rl, rl2); 1365 if (IS_ERR(rl)) { 1366 up_write(&mftbmp_ni->runlist.lock); 1367 ntfs_error(vol->sb, "Failed to merge runlists for mft " 1368 "bitmap."); 1369 if (ntfs_cluster_free_from_rl(vol, rl2)) { 1370 ntfs_error(vol->sb, "Failed to dealocate " 1371 "allocated cluster.%s", es); 1372 NVolSetErrors(vol); 1373 } 1374 ntfs_free(rl2); 1375 return PTR_ERR(rl); 1376 } 1377 mftbmp_ni->runlist.rl = rl; 1378 status.added_run = 1; 1379 ntfs_debug("Adding one run to mft bitmap."); 1380 /* Find the last run in the new runlist. */ 1381 for (; rl[1].length; rl++) 1382 ; 1383 } 1384 /* 1385 * Update the attribute record as well. Note: @rl is the last 1386 * (non-terminator) runlist element of mft bitmap. 1387 */ 1388 mrec = map_mft_record(mft_ni); 1389 if (IS_ERR(mrec)) { 1390 ntfs_error(vol->sb, "Failed to map mft record."); 1391 ret = PTR_ERR(mrec); 1392 goto undo_alloc; 1393 } 1394 ctx = ntfs_attr_get_search_ctx(mft_ni, mrec); 1395 if (unlikely(!ctx)) { 1396 ntfs_error(vol->sb, "Failed to get search context."); 1397 ret = -ENOMEM; 1398 goto undo_alloc; 1399 } 1400 ret = ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, 1401 mftbmp_ni->name_len, CASE_SENSITIVE, rl[1].vcn, NULL, 1402 0, ctx); 1403 if (unlikely(ret)) { 1404 ntfs_error(vol->sb, "Failed to find last attribute extent of " 1405 "mft bitmap attribute."); 1406 if (ret == -ENOENT) 1407 ret = -EIO; 1408 goto undo_alloc; 1409 } 1410 a = ctx->attr; 1411 ll = sle64_to_cpu(a->data.non_resident.lowest_vcn); 1412 /* Search back for the previous last allocated cluster of mft bitmap. */ 1413 for (rl2 = rl; rl2 > mftbmp_ni->runlist.rl; rl2--) { 1414 if (ll >= rl2->vcn) 1415 break; 1416 } 1417 BUG_ON(ll < rl2->vcn); 1418 BUG_ON(ll >= rl2->vcn + rl2->length); 1419 /* Get the size for the new mapping pairs array for this extent. */ 1420 mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, ll, -1); 1421 if (unlikely(mp_size <= 0)) { 1422 ntfs_error(vol->sb, "Get size for mapping pairs failed for " 1423 "mft bitmap attribute extent."); 1424 ret = mp_size; 1425 if (!ret) 1426 ret = -EIO; 1427 goto undo_alloc; 1428 } 1429 /* Expand the attribute record if necessary. */ 1430 old_alen = le32_to_cpu(a->length); 1431 ret = ntfs_attr_record_resize(ctx->mrec, a, mp_size + 1432 le16_to_cpu(a->data.non_resident.mapping_pairs_offset)); 1433 if (unlikely(ret)) { 1434 if (ret != -ENOSPC) { 1435 ntfs_error(vol->sb, "Failed to resize attribute " 1436 "record for mft bitmap attribute."); 1437 goto undo_alloc; 1438 } 1439 // TODO: Deal with this by moving this extent to a new mft 1440 // record or by starting a new extent in a new mft record or by 1441 // moving other attributes out of this mft record. 1442 // Note: It will need to be a special mft record and if none of 1443 // those are available it gets rather complicated... 1444 ntfs_error(vol->sb, "Not enough space in this mft record to " 1445 "accomodate extended mft bitmap attribute " 1446 "extent. Cannot handle this yet."); 1447 ret = -EOPNOTSUPP; 1448 goto undo_alloc; 1449 } 1450 status.mp_rebuilt = 1; 1451 /* Generate the mapping pairs array directly into the attr record. */ 1452 ret = ntfs_mapping_pairs_build(vol, (u8*)a + 1453 le16_to_cpu(a->data.non_resident.mapping_pairs_offset), 1454 mp_size, rl2, ll, -1, NULL); 1455 if (unlikely(ret)) { 1456 ntfs_error(vol->sb, "Failed to build mapping pairs array for " 1457 "mft bitmap attribute."); 1458 goto undo_alloc; 1459 } 1460 /* Update the highest_vcn. */ 1461 a->data.non_resident.highest_vcn = cpu_to_sle64(rl[1].vcn - 1); 1462 /* 1463 * We now have extended the mft bitmap allocated_size by one cluster. 1464 * Reflect this in the ntfs_inode structure and the attribute record. 1465 */ 1466 if (a->data.non_resident.lowest_vcn) { 1467 /* 1468 * We are not in the first attribute extent, switch to it, but 1469 * first ensure the changes will make it to disk later. 1470 */ 1471 flush_dcache_mft_record_page(ctx->ntfs_ino); 1472 mark_mft_record_dirty(ctx->ntfs_ino); 1473 ntfs_attr_reinit_search_ctx(ctx); 1474 ret = ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, 1475 mftbmp_ni->name_len, CASE_SENSITIVE, 0, NULL, 1476 0, ctx); 1477 if (unlikely(ret)) { 1478 ntfs_error(vol->sb, "Failed to find first attribute " 1479 "extent of mft bitmap attribute."); 1480 goto restore_undo_alloc; 1481 } 1482 a = ctx->attr; 1483 } 1484 write_lock_irqsave(&mftbmp_ni->size_lock, flags); 1485 mftbmp_ni->allocated_size += vol->cluster_size; 1486 a->data.non_resident.allocated_size = 1487 cpu_to_sle64(mftbmp_ni->allocated_size); 1488 write_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 1489 /* Ensure the changes make it to disk. */ 1490 flush_dcache_mft_record_page(ctx->ntfs_ino); 1491 mark_mft_record_dirty(ctx->ntfs_ino); 1492 ntfs_attr_put_search_ctx(ctx); 1493 unmap_mft_record(mft_ni); 1494 up_write(&mftbmp_ni->runlist.lock); 1495 ntfs_debug("Done."); 1496 return 0; 1497 restore_undo_alloc: 1498 ntfs_attr_reinit_search_ctx(ctx); 1499 if (ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, 1500 mftbmp_ni->name_len, CASE_SENSITIVE, rl[1].vcn, NULL, 1501 0, ctx)) { 1502 ntfs_error(vol->sb, "Failed to find last attribute extent of " 1503 "mft bitmap attribute.%s", es); 1504 write_lock_irqsave(&mftbmp_ni->size_lock, flags); 1505 mftbmp_ni->allocated_size += vol->cluster_size; 1506 write_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 1507 ntfs_attr_put_search_ctx(ctx); 1508 unmap_mft_record(mft_ni); 1509 up_write(&mftbmp_ni->runlist.lock); 1510 /* 1511 * The only thing that is now wrong is ->allocated_size of the 1512 * base attribute extent which chkdsk should be able to fix. 1513 */ 1514 NVolSetErrors(vol); 1515 return ret; 1516 } 1517 a = ctx->attr; 1518 a->data.non_resident.highest_vcn = cpu_to_sle64(rl[1].vcn - 2); 1519 undo_alloc: 1520 if (status.added_cluster) { 1521 /* Truncate the last run in the runlist by one cluster. */ 1522 rl->length--; 1523 rl[1].vcn--; 1524 } else if (status.added_run) { 1525 lcn = rl->lcn; 1526 /* Remove the last run from the runlist. */ 1527 rl->lcn = rl[1].lcn; 1528 rl->length = 0; 1529 } 1530 /* Deallocate the cluster. */ 1531 down_write(&vol->lcnbmp_lock); 1532 if (ntfs_bitmap_clear_bit(vol->lcnbmp_ino, lcn)) { 1533 ntfs_error(vol->sb, "Failed to free allocated cluster.%s", es); 1534 NVolSetErrors(vol); 1535 } 1536 up_write(&vol->lcnbmp_lock); 1537 if (status.mp_rebuilt) { 1538 if (ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu( 1539 a->data.non_resident.mapping_pairs_offset), 1540 old_alen - le16_to_cpu( 1541 a->data.non_resident.mapping_pairs_offset), 1542 rl2, ll, -1, NULL)) { 1543 ntfs_error(vol->sb, "Failed to restore mapping pairs " 1544 "array.%s", es); 1545 NVolSetErrors(vol); 1546 } 1547 if (ntfs_attr_record_resize(ctx->mrec, a, old_alen)) { 1548 ntfs_error(vol->sb, "Failed to restore attribute " 1549 "record.%s", es); 1550 NVolSetErrors(vol); 1551 } 1552 flush_dcache_mft_record_page(ctx->ntfs_ino); 1553 mark_mft_record_dirty(ctx->ntfs_ino); 1554 } 1555 if (ctx) 1556 ntfs_attr_put_search_ctx(ctx); 1557 if (!IS_ERR(mrec)) 1558 unmap_mft_record(mft_ni); 1559 up_write(&mftbmp_ni->runlist.lock); 1560 return ret; 1561 } 1562 1563 /** 1564 * ntfs_mft_bitmap_extend_initialized_nolock - extend mftbmp initialized data 1565 * @vol: volume on which to extend the mft bitmap attribute 1566 * 1567 * Extend the initialized portion of the mft bitmap attribute on the ntfs 1568 * volume @vol by 8 bytes. 1569 * 1570 * Note: Only changes initialized_size and data_size, i.e. requires that 1571 * allocated_size is big enough to fit the new initialized_size. 1572 * 1573 * Return 0 on success and -error on error. 1574 * 1575 * Locking: Caller must hold vol->mftbmp_lock for writing. 1576 */ 1577 static int ntfs_mft_bitmap_extend_initialized_nolock(ntfs_volume *vol) 1578 { 1579 s64 old_data_size, old_initialized_size; 1580 unsigned long flags; 1581 struct inode *mftbmp_vi; 1582 ntfs_inode *mft_ni, *mftbmp_ni; 1583 ntfs_attr_search_ctx *ctx; 1584 MFT_RECORD *mrec; 1585 ATTR_RECORD *a; 1586 int ret; 1587 1588 ntfs_debug("Extending mft bitmap initiailized (and data) size."); 1589 mft_ni = NTFS_I(vol->mft_ino); 1590 mftbmp_vi = vol->mftbmp_ino; 1591 mftbmp_ni = NTFS_I(mftbmp_vi); 1592 /* Get the attribute record. */ 1593 mrec = map_mft_record(mft_ni); 1594 if (IS_ERR(mrec)) { 1595 ntfs_error(vol->sb, "Failed to map mft record."); 1596 return PTR_ERR(mrec); 1597 } 1598 ctx = ntfs_attr_get_search_ctx(mft_ni, mrec); 1599 if (unlikely(!ctx)) { 1600 ntfs_error(vol->sb, "Failed to get search context."); 1601 ret = -ENOMEM; 1602 goto unm_err_out; 1603 } 1604 ret = ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, 1605 mftbmp_ni->name_len, CASE_SENSITIVE, 0, NULL, 0, ctx); 1606 if (unlikely(ret)) { 1607 ntfs_error(vol->sb, "Failed to find first attribute extent of " 1608 "mft bitmap attribute."); 1609 if (ret == -ENOENT) 1610 ret = -EIO; 1611 goto put_err_out; 1612 } 1613 a = ctx->attr; 1614 write_lock_irqsave(&mftbmp_ni->size_lock, flags); 1615 old_data_size = i_size_read(mftbmp_vi); 1616 old_initialized_size = mftbmp_ni->initialized_size; 1617 /* 1618 * We can simply update the initialized_size before filling the space 1619 * with zeroes because the caller is holding the mft bitmap lock for 1620 * writing which ensures that no one else is trying to access the data. 1621 */ 1622 mftbmp_ni->initialized_size += 8; 1623 a->data.non_resident.initialized_size = 1624 cpu_to_sle64(mftbmp_ni->initialized_size); 1625 if (mftbmp_ni->initialized_size > old_data_size) { 1626 i_size_write(mftbmp_vi, mftbmp_ni->initialized_size); 1627 a->data.non_resident.data_size = 1628 cpu_to_sle64(mftbmp_ni->initialized_size); 1629 } 1630 write_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 1631 /* Ensure the changes make it to disk. */ 1632 flush_dcache_mft_record_page(ctx->ntfs_ino); 1633 mark_mft_record_dirty(ctx->ntfs_ino); 1634 ntfs_attr_put_search_ctx(ctx); 1635 unmap_mft_record(mft_ni); 1636 /* Initialize the mft bitmap attribute value with zeroes. */ 1637 ret = ntfs_attr_set(mftbmp_ni, old_initialized_size, 8, 0); 1638 if (likely(!ret)) { 1639 ntfs_debug("Done. (Wrote eight initialized bytes to mft " 1640 "bitmap."); 1641 return 0; 1642 } 1643 ntfs_error(vol->sb, "Failed to write to mft bitmap."); 1644 /* Try to recover from the error. */ 1645 mrec = map_mft_record(mft_ni); 1646 if (IS_ERR(mrec)) { 1647 ntfs_error(vol->sb, "Failed to map mft record.%s", es); 1648 NVolSetErrors(vol); 1649 return ret; 1650 } 1651 ctx = ntfs_attr_get_search_ctx(mft_ni, mrec); 1652 if (unlikely(!ctx)) { 1653 ntfs_error(vol->sb, "Failed to get search context.%s", es); 1654 NVolSetErrors(vol); 1655 goto unm_err_out; 1656 } 1657 if (ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, 1658 mftbmp_ni->name_len, CASE_SENSITIVE, 0, NULL, 0, ctx)) { 1659 ntfs_error(vol->sb, "Failed to find first attribute extent of " 1660 "mft bitmap attribute.%s", es); 1661 NVolSetErrors(vol); 1662 put_err_out: 1663 ntfs_attr_put_search_ctx(ctx); 1664 unm_err_out: 1665 unmap_mft_record(mft_ni); 1666 goto err_out; 1667 } 1668 a = ctx->attr; 1669 write_lock_irqsave(&mftbmp_ni->size_lock, flags); 1670 mftbmp_ni->initialized_size = old_initialized_size; 1671 a->data.non_resident.initialized_size = 1672 cpu_to_sle64(old_initialized_size); 1673 if (i_size_read(mftbmp_vi) != old_data_size) { 1674 i_size_write(mftbmp_vi, old_data_size); 1675 a->data.non_resident.data_size = cpu_to_sle64(old_data_size); 1676 } 1677 write_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 1678 flush_dcache_mft_record_page(ctx->ntfs_ino); 1679 mark_mft_record_dirty(ctx->ntfs_ino); 1680 ntfs_attr_put_search_ctx(ctx); 1681 unmap_mft_record(mft_ni); 1682 #ifdef DEBUG 1683 read_lock_irqsave(&mftbmp_ni->size_lock, flags); 1684 ntfs_debug("Restored status of mftbmp: allocated_size 0x%llx, " 1685 "data_size 0x%llx, initialized_size 0x%llx.", 1686 (long long)mftbmp_ni->allocated_size, 1687 (long long)i_size_read(mftbmp_vi), 1688 (long long)mftbmp_ni->initialized_size); 1689 read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 1690 #endif /* DEBUG */ 1691 err_out: 1692 return ret; 1693 } 1694 1695 /** 1696 * ntfs_mft_data_extend_allocation_nolock - extend mft data attribute 1697 * @vol: volume on which to extend the mft data attribute 1698 * 1699 * Extend the mft data attribute on the ntfs volume @vol by 16 mft records 1700 * worth of clusters or if not enough space for this by one mft record worth 1701 * of clusters. 1702 * 1703 * Note: Only changes allocated_size, i.e. does not touch initialized_size or 1704 * data_size. 1705 * 1706 * Return 0 on success and -errno on error. 1707 * 1708 * Locking: - Caller must hold vol->mftbmp_lock for writing. 1709 * - This function takes NTFS_I(vol->mft_ino)->runlist.lock for 1710 * writing and releases it before returning. 1711 * - This function calls functions which take vol->lcnbmp_lock for 1712 * writing and release it before returning. 1713 */ 1714 static int ntfs_mft_data_extend_allocation_nolock(ntfs_volume *vol) 1715 { 1716 LCN lcn; 1717 VCN old_last_vcn; 1718 s64 min_nr, nr, ll; 1719 unsigned long flags; 1720 ntfs_inode *mft_ni; 1721 runlist_element *rl, *rl2; 1722 ntfs_attr_search_ctx *ctx = NULL; 1723 MFT_RECORD *mrec; 1724 ATTR_RECORD *a = NULL; 1725 int ret, mp_size; 1726 u32 old_alen = 0; 1727 bool mp_rebuilt = false; 1728 1729 ntfs_debug("Extending mft data allocation."); 1730 mft_ni = NTFS_I(vol->mft_ino); 1731 /* 1732 * Determine the preferred allocation location, i.e. the last lcn of 1733 * the mft data attribute. The allocated size of the mft data 1734 * attribute cannot be zero so we are ok to do this. 1735 */ 1736 down_write(&mft_ni->runlist.lock); 1737 read_lock_irqsave(&mft_ni->size_lock, flags); 1738 ll = mft_ni->allocated_size; 1739 read_unlock_irqrestore(&mft_ni->size_lock, flags); 1740 rl = ntfs_attr_find_vcn_nolock(mft_ni, 1741 (ll - 1) >> vol->cluster_size_bits, NULL); 1742 if (unlikely(IS_ERR(rl) || !rl->length || rl->lcn < 0)) { 1743 up_write(&mft_ni->runlist.lock); 1744 ntfs_error(vol->sb, "Failed to determine last allocated " 1745 "cluster of mft data attribute."); 1746 if (!IS_ERR(rl)) 1747 ret = -EIO; 1748 else 1749 ret = PTR_ERR(rl); 1750 return ret; 1751 } 1752 lcn = rl->lcn + rl->length; 1753 ntfs_debug("Last lcn of mft data attribute is 0x%llx.", (long long)lcn); 1754 /* Minimum allocation is one mft record worth of clusters. */ 1755 min_nr = vol->mft_record_size >> vol->cluster_size_bits; 1756 if (!min_nr) 1757 min_nr = 1; 1758 /* Want to allocate 16 mft records worth of clusters. */ 1759 nr = vol->mft_record_size << 4 >> vol->cluster_size_bits; 1760 if (!nr) 1761 nr = min_nr; 1762 /* Ensure we do not go above 2^32-1 mft records. */ 1763 read_lock_irqsave(&mft_ni->size_lock, flags); 1764 ll = mft_ni->allocated_size; 1765 read_unlock_irqrestore(&mft_ni->size_lock, flags); 1766 if (unlikely((ll + (nr << vol->cluster_size_bits)) >> 1767 vol->mft_record_size_bits >= (1ll << 32))) { 1768 nr = min_nr; 1769 if (unlikely((ll + (nr << vol->cluster_size_bits)) >> 1770 vol->mft_record_size_bits >= (1ll << 32))) { 1771 ntfs_warning(vol->sb, "Cannot allocate mft record " 1772 "because the maximum number of inodes " 1773 "(2^32) has already been reached."); 1774 up_write(&mft_ni->runlist.lock); 1775 return -ENOSPC; 1776 } 1777 } 1778 ntfs_debug("Trying mft data allocation with %s cluster count %lli.", 1779 nr > min_nr ? "default" : "minimal", (long long)nr); 1780 old_last_vcn = rl[1].vcn; 1781 do { 1782 rl2 = ntfs_cluster_alloc(vol, old_last_vcn, nr, lcn, MFT_ZONE, 1783 true); 1784 if (likely(!IS_ERR(rl2))) 1785 break; 1786 if (PTR_ERR(rl2) != -ENOSPC || nr == min_nr) { 1787 ntfs_error(vol->sb, "Failed to allocate the minimal " 1788 "number of clusters (%lli) for the " 1789 "mft data attribute.", (long long)nr); 1790 up_write(&mft_ni->runlist.lock); 1791 return PTR_ERR(rl2); 1792 } 1793 /* 1794 * There is not enough space to do the allocation, but there 1795 * might be enough space to do a minimal allocation so try that 1796 * before failing. 1797 */ 1798 nr = min_nr; 1799 ntfs_debug("Retrying mft data allocation with minimal cluster " 1800 "count %lli.", (long long)nr); 1801 } while (1); 1802 rl = ntfs_runlists_merge(mft_ni->runlist.rl, rl2); 1803 if (IS_ERR(rl)) { 1804 up_write(&mft_ni->runlist.lock); 1805 ntfs_error(vol->sb, "Failed to merge runlists for mft data " 1806 "attribute."); 1807 if (ntfs_cluster_free_from_rl(vol, rl2)) { 1808 ntfs_error(vol->sb, "Failed to dealocate clusters " 1809 "from the mft data attribute.%s", es); 1810 NVolSetErrors(vol); 1811 } 1812 ntfs_free(rl2); 1813 return PTR_ERR(rl); 1814 } 1815 mft_ni->runlist.rl = rl; 1816 ntfs_debug("Allocated %lli clusters.", (long long)nr); 1817 /* Find the last run in the new runlist. */ 1818 for (; rl[1].length; rl++) 1819 ; 1820 /* Update the attribute record as well. */ 1821 mrec = map_mft_record(mft_ni); 1822 if (IS_ERR(mrec)) { 1823 ntfs_error(vol->sb, "Failed to map mft record."); 1824 ret = PTR_ERR(mrec); 1825 goto undo_alloc; 1826 } 1827 ctx = ntfs_attr_get_search_ctx(mft_ni, mrec); 1828 if (unlikely(!ctx)) { 1829 ntfs_error(vol->sb, "Failed to get search context."); 1830 ret = -ENOMEM; 1831 goto undo_alloc; 1832 } 1833 ret = ntfs_attr_lookup(mft_ni->type, mft_ni->name, mft_ni->name_len, 1834 CASE_SENSITIVE, rl[1].vcn, NULL, 0, ctx); 1835 if (unlikely(ret)) { 1836 ntfs_error(vol->sb, "Failed to find last attribute extent of " 1837 "mft data attribute."); 1838 if (ret == -ENOENT) 1839 ret = -EIO; 1840 goto undo_alloc; 1841 } 1842 a = ctx->attr; 1843 ll = sle64_to_cpu(a->data.non_resident.lowest_vcn); 1844 /* Search back for the previous last allocated cluster of mft bitmap. */ 1845 for (rl2 = rl; rl2 > mft_ni->runlist.rl; rl2--) { 1846 if (ll >= rl2->vcn) 1847 break; 1848 } 1849 BUG_ON(ll < rl2->vcn); 1850 BUG_ON(ll >= rl2->vcn + rl2->length); 1851 /* Get the size for the new mapping pairs array for this extent. */ 1852 mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, ll, -1); 1853 if (unlikely(mp_size <= 0)) { 1854 ntfs_error(vol->sb, "Get size for mapping pairs failed for " 1855 "mft data attribute extent."); 1856 ret = mp_size; 1857 if (!ret) 1858 ret = -EIO; 1859 goto undo_alloc; 1860 } 1861 /* Expand the attribute record if necessary. */ 1862 old_alen = le32_to_cpu(a->length); 1863 ret = ntfs_attr_record_resize(ctx->mrec, a, mp_size + 1864 le16_to_cpu(a->data.non_resident.mapping_pairs_offset)); 1865 if (unlikely(ret)) { 1866 if (ret != -ENOSPC) { 1867 ntfs_error(vol->sb, "Failed to resize attribute " 1868 "record for mft data attribute."); 1869 goto undo_alloc; 1870 } 1871 // TODO: Deal with this by moving this extent to a new mft 1872 // record or by starting a new extent in a new mft record or by 1873 // moving other attributes out of this mft record. 1874 // Note: Use the special reserved mft records and ensure that 1875 // this extent is not required to find the mft record in 1876 // question. If no free special records left we would need to 1877 // move an existing record away, insert ours in its place, and 1878 // then place the moved record into the newly allocated space 1879 // and we would then need to update all references to this mft 1880 // record appropriately. This is rather complicated... 1881 ntfs_error(vol->sb, "Not enough space in this mft record to " 1882 "accomodate extended mft data attribute " 1883 "extent. Cannot handle this yet."); 1884 ret = -EOPNOTSUPP; 1885 goto undo_alloc; 1886 } 1887 mp_rebuilt = true; 1888 /* Generate the mapping pairs array directly into the attr record. */ 1889 ret = ntfs_mapping_pairs_build(vol, (u8*)a + 1890 le16_to_cpu(a->data.non_resident.mapping_pairs_offset), 1891 mp_size, rl2, ll, -1, NULL); 1892 if (unlikely(ret)) { 1893 ntfs_error(vol->sb, "Failed to build mapping pairs array of " 1894 "mft data attribute."); 1895 goto undo_alloc; 1896 } 1897 /* Update the highest_vcn. */ 1898 a->data.non_resident.highest_vcn = cpu_to_sle64(rl[1].vcn - 1); 1899 /* 1900 * We now have extended the mft data allocated_size by nr clusters. 1901 * Reflect this in the ntfs_inode structure and the attribute record. 1902 * @rl is the last (non-terminator) runlist element of mft data 1903 * attribute. 1904 */ 1905 if (a->data.non_resident.lowest_vcn) { 1906 /* 1907 * We are not in the first attribute extent, switch to it, but 1908 * first ensure the changes will make it to disk later. 1909 */ 1910 flush_dcache_mft_record_page(ctx->ntfs_ino); 1911 mark_mft_record_dirty(ctx->ntfs_ino); 1912 ntfs_attr_reinit_search_ctx(ctx); 1913 ret = ntfs_attr_lookup(mft_ni->type, mft_ni->name, 1914 mft_ni->name_len, CASE_SENSITIVE, 0, NULL, 0, 1915 ctx); 1916 if (unlikely(ret)) { 1917 ntfs_error(vol->sb, "Failed to find first attribute " 1918 "extent of mft data attribute."); 1919 goto restore_undo_alloc; 1920 } 1921 a = ctx->attr; 1922 } 1923 write_lock_irqsave(&mft_ni->size_lock, flags); 1924 mft_ni->allocated_size += nr << vol->cluster_size_bits; 1925 a->data.non_resident.allocated_size = 1926 cpu_to_sle64(mft_ni->allocated_size); 1927 write_unlock_irqrestore(&mft_ni->size_lock, flags); 1928 /* Ensure the changes make it to disk. */ 1929 flush_dcache_mft_record_page(ctx->ntfs_ino); 1930 mark_mft_record_dirty(ctx->ntfs_ino); 1931 ntfs_attr_put_search_ctx(ctx); 1932 unmap_mft_record(mft_ni); 1933 up_write(&mft_ni->runlist.lock); 1934 ntfs_debug("Done."); 1935 return 0; 1936 restore_undo_alloc: 1937 ntfs_attr_reinit_search_ctx(ctx); 1938 if (ntfs_attr_lookup(mft_ni->type, mft_ni->name, mft_ni->name_len, 1939 CASE_SENSITIVE, rl[1].vcn, NULL, 0, ctx)) { 1940 ntfs_error(vol->sb, "Failed to find last attribute extent of " 1941 "mft data attribute.%s", es); 1942 write_lock_irqsave(&mft_ni->size_lock, flags); 1943 mft_ni->allocated_size += nr << vol->cluster_size_bits; 1944 write_unlock_irqrestore(&mft_ni->size_lock, flags); 1945 ntfs_attr_put_search_ctx(ctx); 1946 unmap_mft_record(mft_ni); 1947 up_write(&mft_ni->runlist.lock); 1948 /* 1949 * The only thing that is now wrong is ->allocated_size of the 1950 * base attribute extent which chkdsk should be able to fix. 1951 */ 1952 NVolSetErrors(vol); 1953 return ret; 1954 } 1955 ctx->attr->data.non_resident.highest_vcn = 1956 cpu_to_sle64(old_last_vcn - 1); 1957 undo_alloc: 1958 if (ntfs_cluster_free(mft_ni, old_last_vcn, -1, ctx) < 0) { 1959 ntfs_error(vol->sb, "Failed to free clusters from mft data " 1960 "attribute.%s", es); 1961 NVolSetErrors(vol); 1962 } 1963 a = ctx->attr; 1964 if (ntfs_rl_truncate_nolock(vol, &mft_ni->runlist, old_last_vcn)) { 1965 ntfs_error(vol->sb, "Failed to truncate mft data attribute " 1966 "runlist.%s", es); 1967 NVolSetErrors(vol); 1968 } 1969 if (mp_rebuilt && !IS_ERR(ctx->mrec)) { 1970 if (ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu( 1971 a->data.non_resident.mapping_pairs_offset), 1972 old_alen - le16_to_cpu( 1973 a->data.non_resident.mapping_pairs_offset), 1974 rl2, ll, -1, NULL)) { 1975 ntfs_error(vol->sb, "Failed to restore mapping pairs " 1976 "array.%s", es); 1977 NVolSetErrors(vol); 1978 } 1979 if (ntfs_attr_record_resize(ctx->mrec, a, old_alen)) { 1980 ntfs_error(vol->sb, "Failed to restore attribute " 1981 "record.%s", es); 1982 NVolSetErrors(vol); 1983 } 1984 flush_dcache_mft_record_page(ctx->ntfs_ino); 1985 mark_mft_record_dirty(ctx->ntfs_ino); 1986 } else if (IS_ERR(ctx->mrec)) { 1987 ntfs_error(vol->sb, "Failed to restore attribute search " 1988 "context.%s", es); 1989 NVolSetErrors(vol); 1990 } 1991 if (ctx) 1992 ntfs_attr_put_search_ctx(ctx); 1993 if (!IS_ERR(mrec)) 1994 unmap_mft_record(mft_ni); 1995 up_write(&mft_ni->runlist.lock); 1996 return ret; 1997 } 1998 1999 /** 2000 * ntfs_mft_record_layout - layout an mft record into a memory buffer 2001 * @vol: volume to which the mft record will belong 2002 * @mft_no: mft reference specifying the mft record number 2003 * @m: destination buffer of size >= @vol->mft_record_size bytes 2004 * 2005 * Layout an empty, unused mft record with the mft record number @mft_no into 2006 * the buffer @m. The volume @vol is needed because the mft record structure 2007 * was modified in NTFS 3.1 so we need to know which volume version this mft 2008 * record will be used on. 2009 * 2010 * Return 0 on success and -errno on error. 2011 */ 2012 static int ntfs_mft_record_layout(const ntfs_volume *vol, const s64 mft_no, 2013 MFT_RECORD *m) 2014 { 2015 ATTR_RECORD *a; 2016 2017 ntfs_debug("Entering for mft record 0x%llx.", (long long)mft_no); 2018 if (mft_no >= (1ll << 32)) { 2019 ntfs_error(vol->sb, "Mft record number 0x%llx exceeds " 2020 "maximum of 2^32.", (long long)mft_no); 2021 return -ERANGE; 2022 } 2023 /* Start by clearing the whole mft record to gives us a clean slate. */ 2024 memset(m, 0, vol->mft_record_size); 2025 /* Aligned to 2-byte boundary. */ 2026 if (vol->major_ver < 3 || (vol->major_ver == 3 && !vol->minor_ver)) 2027 m->usa_ofs = cpu_to_le16((sizeof(MFT_RECORD_OLD) + 1) & ~1); 2028 else { 2029 m->usa_ofs = cpu_to_le16((sizeof(MFT_RECORD) + 1) & ~1); 2030 /* 2031 * Set the NTFS 3.1+ specific fields while we know that the 2032 * volume version is 3.1+. 2033 */ 2034 m->reserved = 0; 2035 m->mft_record_number = cpu_to_le32((u32)mft_no); 2036 } 2037 m->magic = magic_FILE; 2038 if (vol->mft_record_size >= NTFS_BLOCK_SIZE) 2039 m->usa_count = cpu_to_le16(vol->mft_record_size / 2040 NTFS_BLOCK_SIZE + 1); 2041 else { 2042 m->usa_count = cpu_to_le16(1); 2043 ntfs_warning(vol->sb, "Sector size is bigger than mft record " 2044 "size. Setting usa_count to 1. If chkdsk " 2045 "reports this as corruption, please email " 2046 "linux-ntfs-dev@lists.sourceforge.net stating " 2047 "that you saw this message and that the " 2048 "modified filesystem created was corrupt. " 2049 "Thank you."); 2050 } 2051 /* Set the update sequence number to 1. */ 2052 *(le16*)((u8*)m + le16_to_cpu(m->usa_ofs)) = cpu_to_le16(1); 2053 m->lsn = 0; 2054 m->sequence_number = cpu_to_le16(1); 2055 m->link_count = 0; 2056 /* 2057 * Place the attributes straight after the update sequence array, 2058 * aligned to 8-byte boundary. 2059 */ 2060 m->attrs_offset = cpu_to_le16((le16_to_cpu(m->usa_ofs) + 2061 (le16_to_cpu(m->usa_count) << 1) + 7) & ~7); 2062 m->flags = 0; 2063 /* 2064 * Using attrs_offset plus eight bytes (for the termination attribute). 2065 * attrs_offset is already aligned to 8-byte boundary, so no need to 2066 * align again. 2067 */ 2068 m->bytes_in_use = cpu_to_le32(le16_to_cpu(m->attrs_offset) + 8); 2069 m->bytes_allocated = cpu_to_le32(vol->mft_record_size); 2070 m->base_mft_record = 0; 2071 m->next_attr_instance = 0; 2072 /* Add the termination attribute. */ 2073 a = (ATTR_RECORD*)((u8*)m + le16_to_cpu(m->attrs_offset)); 2074 a->type = AT_END; 2075 a->length = 0; 2076 ntfs_debug("Done."); 2077 return 0; 2078 } 2079 2080 /** 2081 * ntfs_mft_record_format - format an mft record on an ntfs volume 2082 * @vol: volume on which to format the mft record 2083 * @mft_no: mft record number to format 2084 * 2085 * Format the mft record @mft_no in $MFT/$DATA, i.e. lay out an empty, unused 2086 * mft record into the appropriate place of the mft data attribute. This is 2087 * used when extending the mft data attribute. 2088 * 2089 * Return 0 on success and -errno on error. 2090 */ 2091 static int ntfs_mft_record_format(const ntfs_volume *vol, const s64 mft_no) 2092 { 2093 loff_t i_size; 2094 struct inode *mft_vi = vol->mft_ino; 2095 struct page *page; 2096 MFT_RECORD *m; 2097 pgoff_t index, end_index; 2098 unsigned int ofs; 2099 int err; 2100 2101 ntfs_debug("Entering for mft record 0x%llx.", (long long)mft_no); 2102 /* 2103 * The index into the page cache and the offset within the page cache 2104 * page of the wanted mft record. 2105 */ 2106 index = mft_no << vol->mft_record_size_bits >> PAGE_CACHE_SHIFT; 2107 ofs = (mft_no << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK; 2108 /* The maximum valid index into the page cache for $MFT's data. */ 2109 i_size = i_size_read(mft_vi); 2110 end_index = i_size >> PAGE_CACHE_SHIFT; 2111 if (unlikely(index >= end_index)) { 2112 if (unlikely(index > end_index || ofs + vol->mft_record_size >= 2113 (i_size & ~PAGE_CACHE_MASK))) { 2114 ntfs_error(vol->sb, "Tried to format non-existing mft " 2115 "record 0x%llx.", (long long)mft_no); 2116 return -ENOENT; 2117 } 2118 } 2119 /* Read, map, and pin the page containing the mft record. */ 2120 page = ntfs_map_page(mft_vi->i_mapping, index); 2121 if (IS_ERR(page)) { 2122 ntfs_error(vol->sb, "Failed to map page containing mft record " 2123 "to format 0x%llx.", (long long)mft_no); 2124 return PTR_ERR(page); 2125 } 2126 lock_page(page); 2127 BUG_ON(!PageUptodate(page)); 2128 ClearPageUptodate(page); 2129 m = (MFT_RECORD*)((u8*)page_address(page) + ofs); 2130 err = ntfs_mft_record_layout(vol, mft_no, m); 2131 if (unlikely(err)) { 2132 ntfs_error(vol->sb, "Failed to layout mft record 0x%llx.", 2133 (long long)mft_no); 2134 SetPageUptodate(page); 2135 unlock_page(page); 2136 ntfs_unmap_page(page); 2137 return err; 2138 } 2139 flush_dcache_page(page); 2140 SetPageUptodate(page); 2141 unlock_page(page); 2142 /* 2143 * Make sure the mft record is written out to disk. We could use 2144 * ilookup5() to check if an inode is in icache and so on but this is 2145 * unnecessary as ntfs_writepage() will write the dirty record anyway. 2146 */ 2147 mark_ntfs_record_dirty(page, ofs); 2148 ntfs_unmap_page(page); 2149 ntfs_debug("Done."); 2150 return 0; 2151 } 2152 2153 /** 2154 * ntfs_mft_record_alloc - allocate an mft record on an ntfs volume 2155 * @vol: [IN] volume on which to allocate the mft record 2156 * @mode: [IN] mode if want a file or directory, i.e. base inode or 0 2157 * @base_ni: [IN] open base inode if allocating an extent mft record or NULL 2158 * @mrec: [OUT] on successful return this is the mapped mft record 2159 * 2160 * Allocate an mft record in $MFT/$DATA of an open ntfs volume @vol. 2161 * 2162 * If @base_ni is NULL make the mft record a base mft record, i.e. a file or 2163 * direvctory inode, and allocate it at the default allocator position. In 2164 * this case @mode is the file mode as given to us by the caller. We in 2165 * particular use @mode to distinguish whether a file or a directory is being 2166 * created (S_IFDIR(mode) and S_IFREG(mode), respectively). 2167 * 2168 * If @base_ni is not NULL make the allocated mft record an extent record, 2169 * allocate it starting at the mft record after the base mft record and attach 2170 * the allocated and opened ntfs inode to the base inode @base_ni. In this 2171 * case @mode must be 0 as it is meaningless for extent inodes. 2172 * 2173 * You need to check the return value with IS_ERR(). If false, the function 2174 * was successful and the return value is the now opened ntfs inode of the 2175 * allocated mft record. *@mrec is then set to the allocated, mapped, pinned, 2176 * and locked mft record. If IS_ERR() is true, the function failed and the 2177 * error code is obtained from PTR_ERR(return value). *@mrec is undefined in 2178 * this case. 2179 * 2180 * Allocation strategy: 2181 * 2182 * To find a free mft record, we scan the mft bitmap for a zero bit. To 2183 * optimize this we start scanning at the place specified by @base_ni or if 2184 * @base_ni is NULL we start where we last stopped and we perform wrap around 2185 * when we reach the end. Note, we do not try to allocate mft records below 2186 * number 24 because numbers 0 to 15 are the defined system files anyway and 16 2187 * to 24 are special in that they are used for storing extension mft records 2188 * for the $DATA attribute of $MFT. This is required to avoid the possibility 2189 * of creating a runlist with a circular dependency which once written to disk 2190 * can never be read in again. Windows will only use records 16 to 24 for 2191 * normal files if the volume is completely out of space. We never use them 2192 * which means that when the volume is really out of space we cannot create any 2193 * more files while Windows can still create up to 8 small files. We can start 2194 * doing this at some later time, it does not matter much for now. 2195 * 2196 * When scanning the mft bitmap, we only search up to the last allocated mft 2197 * record. If there are no free records left in the range 24 to number of 2198 * allocated mft records, then we extend the $MFT/$DATA attribute in order to 2199 * create free mft records. We extend the allocated size of $MFT/$DATA by 16 2200 * records at a time or one cluster, if cluster size is above 16kiB. If there 2201 * is not sufficient space to do this, we try to extend by a single mft record 2202 * or one cluster, if cluster size is above the mft record size. 2203 * 2204 * No matter how many mft records we allocate, we initialize only the first 2205 * allocated mft record, incrementing mft data size and initialized size 2206 * accordingly, open an ntfs_inode for it and return it to the caller, unless 2207 * there are less than 24 mft records, in which case we allocate and initialize 2208 * mft records until we reach record 24 which we consider as the first free mft 2209 * record for use by normal files. 2210 * 2211 * If during any stage we overflow the initialized data in the mft bitmap, we 2212 * extend the initialized size (and data size) by 8 bytes, allocating another 2213 * cluster if required. The bitmap data size has to be at least equal to the 2214 * number of mft records in the mft, but it can be bigger, in which case the 2215 * superflous bits are padded with zeroes. 2216 * 2217 * Thus, when we return successfully (IS_ERR() is false), we will have: 2218 * - initialized / extended the mft bitmap if necessary, 2219 * - initialized / extended the mft data if necessary, 2220 * - set the bit corresponding to the mft record being allocated in the 2221 * mft bitmap, 2222 * - opened an ntfs_inode for the allocated mft record, and we will have 2223 * - returned the ntfs_inode as well as the allocated mapped, pinned, and 2224 * locked mft record. 2225 * 2226 * On error, the volume will be left in a consistent state and no record will 2227 * be allocated. If rolling back a partial operation fails, we may leave some 2228 * inconsistent metadata in which case we set NVolErrors() so the volume is 2229 * left dirty when unmounted. 2230 * 2231 * Note, this function cannot make use of most of the normal functions, like 2232 * for example for attribute resizing, etc, because when the run list overflows 2233 * the base mft record and an attribute list is used, it is very important that 2234 * the extension mft records used to store the $DATA attribute of $MFT can be 2235 * reached without having to read the information contained inside them, as 2236 * this would make it impossible to find them in the first place after the 2237 * volume is unmounted. $MFT/$BITMAP probably does not need to follow this 2238 * rule because the bitmap is not essential for finding the mft records, but on 2239 * the other hand, handling the bitmap in this special way would make life 2240 * easier because otherwise there might be circular invocations of functions 2241 * when reading the bitmap. 2242 */ 2243 ntfs_inode *ntfs_mft_record_alloc(ntfs_volume *vol, const int mode, 2244 ntfs_inode *base_ni, MFT_RECORD **mrec) 2245 { 2246 s64 ll, bit, old_data_initialized, old_data_size; 2247 unsigned long flags; 2248 struct inode *vi; 2249 struct page *page; 2250 ntfs_inode *mft_ni, *mftbmp_ni, *ni; 2251 ntfs_attr_search_ctx *ctx; 2252 MFT_RECORD *m; 2253 ATTR_RECORD *a; 2254 pgoff_t index; 2255 unsigned int ofs; 2256 int err; 2257 le16 seq_no, usn; 2258 bool record_formatted = false; 2259 2260 if (base_ni) { 2261 ntfs_debug("Entering (allocating an extent mft record for " 2262 "base mft record 0x%llx).", 2263 (long long)base_ni->mft_no); 2264 /* @mode and @base_ni are mutually exclusive. */ 2265 BUG_ON(mode); 2266 } else 2267 ntfs_debug("Entering (allocating a base mft record)."); 2268 if (mode) { 2269 /* @mode and @base_ni are mutually exclusive. */ 2270 BUG_ON(base_ni); 2271 /* We only support creation of normal files and directories. */ 2272 if (!S_ISREG(mode) && !S_ISDIR(mode)) 2273 return ERR_PTR(-EOPNOTSUPP); 2274 } 2275 BUG_ON(!mrec); 2276 mft_ni = NTFS_I(vol->mft_ino); 2277 mftbmp_ni = NTFS_I(vol->mftbmp_ino); 2278 down_write(&vol->mftbmp_lock); 2279 bit = ntfs_mft_bitmap_find_and_alloc_free_rec_nolock(vol, base_ni); 2280 if (bit >= 0) { 2281 ntfs_debug("Found and allocated free record (#1), bit 0x%llx.", 2282 (long long)bit); 2283 goto have_alloc_rec; 2284 } 2285 if (bit != -ENOSPC) { 2286 up_write(&vol->mftbmp_lock); 2287 return ERR_PTR(bit); 2288 } 2289 /* 2290 * No free mft records left. If the mft bitmap already covers more 2291 * than the currently used mft records, the next records are all free, 2292 * so we can simply allocate the first unused mft record. 2293 * Note: We also have to make sure that the mft bitmap at least covers 2294 * the first 24 mft records as they are special and whilst they may not 2295 * be in use, we do not allocate from them. 2296 */ 2297 read_lock_irqsave(&mft_ni->size_lock, flags); 2298 ll = mft_ni->initialized_size >> vol->mft_record_size_bits; 2299 read_unlock_irqrestore(&mft_ni->size_lock, flags); 2300 read_lock_irqsave(&mftbmp_ni->size_lock, flags); 2301 old_data_initialized = mftbmp_ni->initialized_size; 2302 read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 2303 if (old_data_initialized << 3 > ll && old_data_initialized > 3) { 2304 bit = ll; 2305 if (bit < 24) 2306 bit = 24; 2307 if (unlikely(bit >= (1ll << 32))) 2308 goto max_err_out; 2309 ntfs_debug("Found free record (#2), bit 0x%llx.", 2310 (long long)bit); 2311 goto found_free_rec; 2312 } 2313 /* 2314 * The mft bitmap needs to be expanded until it covers the first unused 2315 * mft record that we can allocate. 2316 * Note: The smallest mft record we allocate is mft record 24. 2317 */ 2318 bit = old_data_initialized << 3; 2319 if (unlikely(bit >= (1ll << 32))) 2320 goto max_err_out; 2321 read_lock_irqsave(&mftbmp_ni->size_lock, flags); 2322 old_data_size = mftbmp_ni->allocated_size; 2323 ntfs_debug("Status of mftbmp before extension: allocated_size 0x%llx, " 2324 "data_size 0x%llx, initialized_size 0x%llx.", 2325 (long long)old_data_size, 2326 (long long)i_size_read(vol->mftbmp_ino), 2327 (long long)old_data_initialized); 2328 read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 2329 if (old_data_initialized + 8 > old_data_size) { 2330 /* Need to extend bitmap by one more cluster. */ 2331 ntfs_debug("mftbmp: initialized_size + 8 > allocated_size."); 2332 err = ntfs_mft_bitmap_extend_allocation_nolock(vol); 2333 if (unlikely(err)) { 2334 up_write(&vol->mftbmp_lock); 2335 goto err_out; 2336 } 2337 #ifdef DEBUG 2338 read_lock_irqsave(&mftbmp_ni->size_lock, flags); 2339 ntfs_debug("Status of mftbmp after allocation extension: " 2340 "allocated_size 0x%llx, data_size 0x%llx, " 2341 "initialized_size 0x%llx.", 2342 (long long)mftbmp_ni->allocated_size, 2343 (long long)i_size_read(vol->mftbmp_ino), 2344 (long long)mftbmp_ni->initialized_size); 2345 read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 2346 #endif /* DEBUG */ 2347 } 2348 /* 2349 * We now have sufficient allocated space, extend the initialized_size 2350 * as well as the data_size if necessary and fill the new space with 2351 * zeroes. 2352 */ 2353 err = ntfs_mft_bitmap_extend_initialized_nolock(vol); 2354 if (unlikely(err)) { 2355 up_write(&vol->mftbmp_lock); 2356 goto err_out; 2357 } 2358 #ifdef DEBUG 2359 read_lock_irqsave(&mftbmp_ni->size_lock, flags); 2360 ntfs_debug("Status of mftbmp after initialized extention: " 2361 "allocated_size 0x%llx, data_size 0x%llx, " 2362 "initialized_size 0x%llx.", 2363 (long long)mftbmp_ni->allocated_size, 2364 (long long)i_size_read(vol->mftbmp_ino), 2365 (long long)mftbmp_ni->initialized_size); 2366 read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 2367 #endif /* DEBUG */ 2368 ntfs_debug("Found free record (#3), bit 0x%llx.", (long long)bit); 2369 found_free_rec: 2370 /* @bit is the found free mft record, allocate it in the mft bitmap. */ 2371 ntfs_debug("At found_free_rec."); 2372 err = ntfs_bitmap_set_bit(vol->mftbmp_ino, bit); 2373 if (unlikely(err)) { 2374 ntfs_error(vol->sb, "Failed to allocate bit in mft bitmap."); 2375 up_write(&vol->mftbmp_lock); 2376 goto err_out; 2377 } 2378 ntfs_debug("Set bit 0x%llx in mft bitmap.", (long long)bit); 2379 have_alloc_rec: 2380 /* 2381 * The mft bitmap is now uptodate. Deal with mft data attribute now. 2382 * Note, we keep hold of the mft bitmap lock for writing until all 2383 * modifications to the mft data attribute are complete, too, as they 2384 * will impact decisions for mft bitmap and mft record allocation done 2385 * by a parallel allocation and if the lock is not maintained a 2386 * parallel allocation could allocate the same mft record as this one. 2387 */ 2388 ll = (bit + 1) << vol->mft_record_size_bits; 2389 read_lock_irqsave(&mft_ni->size_lock, flags); 2390 old_data_initialized = mft_ni->initialized_size; 2391 read_unlock_irqrestore(&mft_ni->size_lock, flags); 2392 if (ll <= old_data_initialized) { 2393 ntfs_debug("Allocated mft record already initialized."); 2394 goto mft_rec_already_initialized; 2395 } 2396 ntfs_debug("Initializing allocated mft record."); 2397 /* 2398 * The mft record is outside the initialized data. Extend the mft data 2399 * attribute until it covers the allocated record. The loop is only 2400 * actually traversed more than once when a freshly formatted volume is 2401 * first written to so it optimizes away nicely in the common case. 2402 */ 2403 read_lock_irqsave(&mft_ni->size_lock, flags); 2404 ntfs_debug("Status of mft data before extension: " 2405 "allocated_size 0x%llx, data_size 0x%llx, " 2406 "initialized_size 0x%llx.", 2407 (long long)mft_ni->allocated_size, 2408 (long long)i_size_read(vol->mft_ino), 2409 (long long)mft_ni->initialized_size); 2410 while (ll > mft_ni->allocated_size) { 2411 read_unlock_irqrestore(&mft_ni->size_lock, flags); 2412 err = ntfs_mft_data_extend_allocation_nolock(vol); 2413 if (unlikely(err)) { 2414 ntfs_error(vol->sb, "Failed to extend mft data " 2415 "allocation."); 2416 goto undo_mftbmp_alloc_nolock; 2417 } 2418 read_lock_irqsave(&mft_ni->size_lock, flags); 2419 ntfs_debug("Status of mft data after allocation extension: " 2420 "allocated_size 0x%llx, data_size 0x%llx, " 2421 "initialized_size 0x%llx.", 2422 (long long)mft_ni->allocated_size, 2423 (long long)i_size_read(vol->mft_ino), 2424 (long long)mft_ni->initialized_size); 2425 } 2426 read_unlock_irqrestore(&mft_ni->size_lock, flags); 2427 /* 2428 * Extend mft data initialized size (and data size of course) to reach 2429 * the allocated mft record, formatting the mft records allong the way. 2430 * Note: We only modify the ntfs_inode structure as that is all that is 2431 * needed by ntfs_mft_record_format(). We will update the attribute 2432 * record itself in one fell swoop later on. 2433 */ 2434 write_lock_irqsave(&mft_ni->size_lock, flags); 2435 old_data_initialized = mft_ni->initialized_size; 2436 old_data_size = vol->mft_ino->i_size; 2437 while (ll > mft_ni->initialized_size) { 2438 s64 new_initialized_size, mft_no; 2439 2440 new_initialized_size = mft_ni->initialized_size + 2441 vol->mft_record_size; 2442 mft_no = mft_ni->initialized_size >> vol->mft_record_size_bits; 2443 if (new_initialized_size > i_size_read(vol->mft_ino)) 2444 i_size_write(vol->mft_ino, new_initialized_size); 2445 write_unlock_irqrestore(&mft_ni->size_lock, flags); 2446 ntfs_debug("Initializing mft record 0x%llx.", 2447 (long long)mft_no); 2448 err = ntfs_mft_record_format(vol, mft_no); 2449 if (unlikely(err)) { 2450 ntfs_error(vol->sb, "Failed to format mft record."); 2451 goto undo_data_init; 2452 } 2453 write_lock_irqsave(&mft_ni->size_lock, flags); 2454 mft_ni->initialized_size = new_initialized_size; 2455 } 2456 write_unlock_irqrestore(&mft_ni->size_lock, flags); 2457 record_formatted = true; 2458 /* Update the mft data attribute record to reflect the new sizes. */ 2459 m = map_mft_record(mft_ni); 2460 if (IS_ERR(m)) { 2461 ntfs_error(vol->sb, "Failed to map mft record."); 2462 err = PTR_ERR(m); 2463 goto undo_data_init; 2464 } 2465 ctx = ntfs_attr_get_search_ctx(mft_ni, m); 2466 if (unlikely(!ctx)) { 2467 ntfs_error(vol->sb, "Failed to get search context."); 2468 err = -ENOMEM; 2469 unmap_mft_record(mft_ni); 2470 goto undo_data_init; 2471 } 2472 err = ntfs_attr_lookup(mft_ni->type, mft_ni->name, mft_ni->name_len, 2473 CASE_SENSITIVE, 0, NULL, 0, ctx); 2474 if (unlikely(err)) { 2475 ntfs_error(vol->sb, "Failed to find first attribute extent of " 2476 "mft data attribute."); 2477 ntfs_attr_put_search_ctx(ctx); 2478 unmap_mft_record(mft_ni); 2479 goto undo_data_init; 2480 } 2481 a = ctx->attr; 2482 read_lock_irqsave(&mft_ni->size_lock, flags); 2483 a->data.non_resident.initialized_size = 2484 cpu_to_sle64(mft_ni->initialized_size); 2485 a->data.non_resident.data_size = 2486 cpu_to_sle64(i_size_read(vol->mft_ino)); 2487 read_unlock_irqrestore(&mft_ni->size_lock, flags); 2488 /* Ensure the changes make it to disk. */ 2489 flush_dcache_mft_record_page(ctx->ntfs_ino); 2490 mark_mft_record_dirty(ctx->ntfs_ino); 2491 ntfs_attr_put_search_ctx(ctx); 2492 unmap_mft_record(mft_ni); 2493 read_lock_irqsave(&mft_ni->size_lock, flags); 2494 ntfs_debug("Status of mft data after mft record initialization: " 2495 "allocated_size 0x%llx, data_size 0x%llx, " 2496 "initialized_size 0x%llx.", 2497 (long long)mft_ni->allocated_size, 2498 (long long)i_size_read(vol->mft_ino), 2499 (long long)mft_ni->initialized_size); 2500 BUG_ON(i_size_read(vol->mft_ino) > mft_ni->allocated_size); 2501 BUG_ON(mft_ni->initialized_size > i_size_read(vol->mft_ino)); 2502 read_unlock_irqrestore(&mft_ni->size_lock, flags); 2503 mft_rec_already_initialized: 2504 /* 2505 * We can finally drop the mft bitmap lock as the mft data attribute 2506 * has been fully updated. The only disparity left is that the 2507 * allocated mft record still needs to be marked as in use to match the 2508 * set bit in the mft bitmap but this is actually not a problem since 2509 * this mft record is not referenced from anywhere yet and the fact 2510 * that it is allocated in the mft bitmap means that no-one will try to 2511 * allocate it either. 2512 */ 2513 up_write(&vol->mftbmp_lock); 2514 /* 2515 * We now have allocated and initialized the mft record. Calculate the 2516 * index of and the offset within the page cache page the record is in. 2517 */ 2518 index = bit << vol->mft_record_size_bits >> PAGE_CACHE_SHIFT; 2519 ofs = (bit << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK; 2520 /* Read, map, and pin the page containing the mft record. */ 2521 page = ntfs_map_page(vol->mft_ino->i_mapping, index); 2522 if (IS_ERR(page)) { 2523 ntfs_error(vol->sb, "Failed to map page containing allocated " 2524 "mft record 0x%llx.", (long long)bit); 2525 err = PTR_ERR(page); 2526 goto undo_mftbmp_alloc; 2527 } 2528 lock_page(page); 2529 BUG_ON(!PageUptodate(page)); 2530 ClearPageUptodate(page); 2531 m = (MFT_RECORD*)((u8*)page_address(page) + ofs); 2532 /* If we just formatted the mft record no need to do it again. */ 2533 if (!record_formatted) { 2534 /* Sanity check that the mft record is really not in use. */ 2535 if (ntfs_is_file_record(m->magic) && 2536 (m->flags & MFT_RECORD_IN_USE)) { 2537 ntfs_error(vol->sb, "Mft record 0x%llx was marked " 2538 "free in mft bitmap but is marked " 2539 "used itself. Corrupt filesystem. " 2540 "Unmount and run chkdsk.", 2541 (long long)bit); 2542 err = -EIO; 2543 SetPageUptodate(page); 2544 unlock_page(page); 2545 ntfs_unmap_page(page); 2546 NVolSetErrors(vol); 2547 goto undo_mftbmp_alloc; 2548 } 2549 /* 2550 * We need to (re-)format the mft record, preserving the 2551 * sequence number if it is not zero as well as the update 2552 * sequence number if it is not zero or -1 (0xffff). This 2553 * means we do not need to care whether or not something went 2554 * wrong with the previous mft record. 2555 */ 2556 seq_no = m->sequence_number; 2557 usn = *(le16*)((u8*)m + le16_to_cpu(m->usa_ofs)); 2558 err = ntfs_mft_record_layout(vol, bit, m); 2559 if (unlikely(err)) { 2560 ntfs_error(vol->sb, "Failed to layout allocated mft " 2561 "record 0x%llx.", (long long)bit); 2562 SetPageUptodate(page); 2563 unlock_page(page); 2564 ntfs_unmap_page(page); 2565 goto undo_mftbmp_alloc; 2566 } 2567 if (seq_no) 2568 m->sequence_number = seq_no; 2569 if (usn && le16_to_cpu(usn) != 0xffff) 2570 *(le16*)((u8*)m + le16_to_cpu(m->usa_ofs)) = usn; 2571 } 2572 /* Set the mft record itself in use. */ 2573 m->flags |= MFT_RECORD_IN_USE; 2574 if (S_ISDIR(mode)) 2575 m->flags |= MFT_RECORD_IS_DIRECTORY; 2576 flush_dcache_page(page); 2577 SetPageUptodate(page); 2578 if (base_ni) { 2579 /* 2580 * Setup the base mft record in the extent mft record. This 2581 * completes initialization of the allocated extent mft record 2582 * and we can simply use it with map_extent_mft_record(). 2583 */ 2584 m->base_mft_record = MK_LE_MREF(base_ni->mft_no, 2585 base_ni->seq_no); 2586 /* 2587 * Allocate an extent inode structure for the new mft record, 2588 * attach it to the base inode @base_ni and map, pin, and lock 2589 * its, i.e. the allocated, mft record. 2590 */ 2591 m = map_extent_mft_record(base_ni, bit, &ni); 2592 if (IS_ERR(m)) { 2593 ntfs_error(vol->sb, "Failed to map allocated extent " 2594 "mft record 0x%llx.", (long long)bit); 2595 err = PTR_ERR(m); 2596 /* Set the mft record itself not in use. */ 2597 m->flags &= cpu_to_le16( 2598 ~le16_to_cpu(MFT_RECORD_IN_USE)); 2599 flush_dcache_page(page); 2600 /* Make sure the mft record is written out to disk. */ 2601 mark_ntfs_record_dirty(page, ofs); 2602 unlock_page(page); 2603 ntfs_unmap_page(page); 2604 goto undo_mftbmp_alloc; 2605 } 2606 /* 2607 * Make sure the allocated mft record is written out to disk. 2608 * No need to set the inode dirty because the caller is going 2609 * to do that anyway after finishing with the new extent mft 2610 * record (e.g. at a minimum a new attribute will be added to 2611 * the mft record. 2612 */ 2613 mark_ntfs_record_dirty(page, ofs); 2614 unlock_page(page); 2615 /* 2616 * Need to unmap the page since map_extent_mft_record() mapped 2617 * it as well so we have it mapped twice at the moment. 2618 */ 2619 ntfs_unmap_page(page); 2620 } else { 2621 /* 2622 * Allocate a new VFS inode and set it up. NOTE: @vi->i_nlink 2623 * is set to 1 but the mft record->link_count is 0. The caller 2624 * needs to bear this in mind. 2625 */ 2626 vi = new_inode(vol->sb); 2627 if (unlikely(!vi)) { 2628 err = -ENOMEM; 2629 /* Set the mft record itself not in use. */ 2630 m->flags &= cpu_to_le16( 2631 ~le16_to_cpu(MFT_RECORD_IN_USE)); 2632 flush_dcache_page(page); 2633 /* Make sure the mft record is written out to disk. */ 2634 mark_ntfs_record_dirty(page, ofs); 2635 unlock_page(page); 2636 ntfs_unmap_page(page); 2637 goto undo_mftbmp_alloc; 2638 } 2639 vi->i_ino = bit; 2640 /* 2641 * This is for checking whether an inode has changed w.r.t. a 2642 * file so that the file can be updated if necessary (compare 2643 * with f_version). 2644 */ 2645 vi->i_version = 1; 2646 2647 /* The owner and group come from the ntfs volume. */ 2648 vi->i_uid = vol->uid; 2649 vi->i_gid = vol->gid; 2650 2651 /* Initialize the ntfs specific part of @vi. */ 2652 ntfs_init_big_inode(vi); 2653 ni = NTFS_I(vi); 2654 /* 2655 * Set the appropriate mode, attribute type, and name. For 2656 * directories, also setup the index values to the defaults. 2657 */ 2658 if (S_ISDIR(mode)) { 2659 vi->i_mode = S_IFDIR | S_IRWXUGO; 2660 vi->i_mode &= ~vol->dmask; 2661 2662 NInoSetMstProtected(ni); 2663 ni->type = AT_INDEX_ALLOCATION; 2664 ni->name = I30; 2665 ni->name_len = 4; 2666 2667 ni->itype.index.block_size = 4096; 2668 ni->itype.index.block_size_bits = ntfs_ffs(4096) - 1; 2669 ni->itype.index.collation_rule = COLLATION_FILE_NAME; 2670 if (vol->cluster_size <= ni->itype.index.block_size) { 2671 ni->itype.index.vcn_size = vol->cluster_size; 2672 ni->itype.index.vcn_size_bits = 2673 vol->cluster_size_bits; 2674 } else { 2675 ni->itype.index.vcn_size = vol->sector_size; 2676 ni->itype.index.vcn_size_bits = 2677 vol->sector_size_bits; 2678 } 2679 } else { 2680 vi->i_mode = S_IFREG | S_IRWXUGO; 2681 vi->i_mode &= ~vol->fmask; 2682 2683 ni->type = AT_DATA; 2684 ni->name = NULL; 2685 ni->name_len = 0; 2686 } 2687 if (IS_RDONLY(vi)) 2688 vi->i_mode &= ~S_IWUGO; 2689 2690 /* Set the inode times to the current time. */ 2691 vi->i_atime = vi->i_mtime = vi->i_ctime = 2692 current_fs_time(vi->i_sb); 2693 /* 2694 * Set the file size to 0, the ntfs inode sizes are set to 0 by 2695 * the call to ntfs_init_big_inode() below. 2696 */ 2697 vi->i_size = 0; 2698 vi->i_blocks = 0; 2699 2700 /* Set the sequence number. */ 2701 vi->i_generation = ni->seq_no = le16_to_cpu(m->sequence_number); 2702 /* 2703 * Manually map, pin, and lock the mft record as we already 2704 * have its page mapped and it is very easy to do. 2705 */ 2706 atomic_inc(&ni->count); 2707 mutex_lock(&ni->mrec_lock); 2708 ni->page = page; 2709 ni->page_ofs = ofs; 2710 /* 2711 * Make sure the allocated mft record is written out to disk. 2712 * NOTE: We do not set the ntfs inode dirty because this would 2713 * fail in ntfs_write_inode() because the inode does not have a 2714 * standard information attribute yet. Also, there is no need 2715 * to set the inode dirty because the caller is going to do 2716 * that anyway after finishing with the new mft record (e.g. at 2717 * a minimum some new attributes will be added to the mft 2718 * record. 2719 */ 2720 mark_ntfs_record_dirty(page, ofs); 2721 unlock_page(page); 2722 2723 /* Add the inode to the inode hash for the superblock. */ 2724 insert_inode_hash(vi); 2725 2726 /* Update the default mft allocation position. */ 2727 vol->mft_data_pos = bit + 1; 2728 } 2729 /* 2730 * Return the opened, allocated inode of the allocated mft record as 2731 * well as the mapped, pinned, and locked mft record. 2732 */ 2733 ntfs_debug("Returning opened, allocated %sinode 0x%llx.", 2734 base_ni ? "extent " : "", (long long)bit); 2735 *mrec = m; 2736 return ni; 2737 undo_data_init: 2738 write_lock_irqsave(&mft_ni->size_lock, flags); 2739 mft_ni->initialized_size = old_data_initialized; 2740 i_size_write(vol->mft_ino, old_data_size); 2741 write_unlock_irqrestore(&mft_ni->size_lock, flags); 2742 goto undo_mftbmp_alloc_nolock; 2743 undo_mftbmp_alloc: 2744 down_write(&vol->mftbmp_lock); 2745 undo_mftbmp_alloc_nolock: 2746 if (ntfs_bitmap_clear_bit(vol->mftbmp_ino, bit)) { 2747 ntfs_error(vol->sb, "Failed to clear bit in mft bitmap.%s", es); 2748 NVolSetErrors(vol); 2749 } 2750 up_write(&vol->mftbmp_lock); 2751 err_out: 2752 return ERR_PTR(err); 2753 max_err_out: 2754 ntfs_warning(vol->sb, "Cannot allocate mft record because the maximum " 2755 "number of inodes (2^32) has already been reached."); 2756 up_write(&vol->mftbmp_lock); 2757 return ERR_PTR(-ENOSPC); 2758 } 2759 2760 /** 2761 * ntfs_extent_mft_record_free - free an extent mft record on an ntfs volume 2762 * @ni: ntfs inode of the mapped extent mft record to free 2763 * @m: mapped extent mft record of the ntfs inode @ni 2764 * 2765 * Free the mapped extent mft record @m of the extent ntfs inode @ni. 2766 * 2767 * Note that this function unmaps the mft record and closes and destroys @ni 2768 * internally and hence you cannot use either @ni nor @m any more after this 2769 * function returns success. 2770 * 2771 * On success return 0 and on error return -errno. @ni and @m are still valid 2772 * in this case and have not been freed. 2773 * 2774 * For some errors an error message is displayed and the success code 0 is 2775 * returned and the volume is then left dirty on umount. This makes sense in 2776 * case we could not rollback the changes that were already done since the 2777 * caller no longer wants to reference this mft record so it does not matter to 2778 * the caller if something is wrong with it as long as it is properly detached 2779 * from the base inode. 2780 */ 2781 int ntfs_extent_mft_record_free(ntfs_inode *ni, MFT_RECORD *m) 2782 { 2783 unsigned long mft_no = ni->mft_no; 2784 ntfs_volume *vol = ni->vol; 2785 ntfs_inode *base_ni; 2786 ntfs_inode **extent_nis; 2787 int i, err; 2788 le16 old_seq_no; 2789 u16 seq_no; 2790 2791 BUG_ON(NInoAttr(ni)); 2792 BUG_ON(ni->nr_extents != -1); 2793 2794 mutex_lock(&ni->extent_lock); 2795 base_ni = ni->ext.base_ntfs_ino; 2796 mutex_unlock(&ni->extent_lock); 2797 2798 BUG_ON(base_ni->nr_extents <= 0); 2799 2800 ntfs_debug("Entering for extent inode 0x%lx, base inode 0x%lx.\n", 2801 mft_no, base_ni->mft_no); 2802 2803 mutex_lock(&base_ni->extent_lock); 2804 2805 /* Make sure we are holding the only reference to the extent inode. */ 2806 if (atomic_read(&ni->count) > 2) { 2807 ntfs_error(vol->sb, "Tried to free busy extent inode 0x%lx, " 2808 "not freeing.", base_ni->mft_no); 2809 mutex_unlock(&base_ni->extent_lock); 2810 return -EBUSY; 2811 } 2812 2813 /* Dissociate the ntfs inode from the base inode. */ 2814 extent_nis = base_ni->ext.extent_ntfs_inos; 2815 err = -ENOENT; 2816 for (i = 0; i < base_ni->nr_extents; i++) { 2817 if (ni != extent_nis[i]) 2818 continue; 2819 extent_nis += i; 2820 base_ni->nr_extents--; 2821 memmove(extent_nis, extent_nis + 1, (base_ni->nr_extents - i) * 2822 sizeof(ntfs_inode*)); 2823 err = 0; 2824 break; 2825 } 2826 2827 mutex_unlock(&base_ni->extent_lock); 2828 2829 if (unlikely(err)) { 2830 ntfs_error(vol->sb, "Extent inode 0x%lx is not attached to " 2831 "its base inode 0x%lx.", mft_no, 2832 base_ni->mft_no); 2833 BUG(); 2834 } 2835 2836 /* 2837 * The extent inode is no longer attached to the base inode so no one 2838 * can get a reference to it any more. 2839 */ 2840 2841 /* Mark the mft record as not in use. */ 2842 m->flags &= const_cpu_to_le16(~const_le16_to_cpu(MFT_RECORD_IN_USE)); 2843 2844 /* Increment the sequence number, skipping zero, if it is not zero. */ 2845 old_seq_no = m->sequence_number; 2846 seq_no = le16_to_cpu(old_seq_no); 2847 if (seq_no == 0xffff) 2848 seq_no = 1; 2849 else if (seq_no) 2850 seq_no++; 2851 m->sequence_number = cpu_to_le16(seq_no); 2852 2853 /* 2854 * Set the ntfs inode dirty and write it out. We do not need to worry 2855 * about the base inode here since whatever caused the extent mft 2856 * record to be freed is guaranteed to do it already. 2857 */ 2858 NInoSetDirty(ni); 2859 err = write_mft_record(ni, m, 0); 2860 if (unlikely(err)) { 2861 ntfs_error(vol->sb, "Failed to write mft record 0x%lx, not " 2862 "freeing.", mft_no); 2863 goto rollback; 2864 } 2865 rollback_error: 2866 /* Unmap and throw away the now freed extent inode. */ 2867 unmap_extent_mft_record(ni); 2868 ntfs_clear_extent_inode(ni); 2869 2870 /* Clear the bit in the $MFT/$BITMAP corresponding to this record. */ 2871 down_write(&vol->mftbmp_lock); 2872 err = ntfs_bitmap_clear_bit(vol->mftbmp_ino, mft_no); 2873 up_write(&vol->mftbmp_lock); 2874 if (unlikely(err)) { 2875 /* 2876 * The extent inode is gone but we failed to deallocate it in 2877 * the mft bitmap. Just emit a warning and leave the volume 2878 * dirty on umount. 2879 */ 2880 ntfs_error(vol->sb, "Failed to clear bit in mft bitmap.%s", es); 2881 NVolSetErrors(vol); 2882 } 2883 return 0; 2884 rollback: 2885 /* Rollback what we did... */ 2886 mutex_lock(&base_ni->extent_lock); 2887 extent_nis = base_ni->ext.extent_ntfs_inos; 2888 if (!(base_ni->nr_extents & 3)) { 2889 int new_size = (base_ni->nr_extents + 4) * sizeof(ntfs_inode*); 2890 2891 extent_nis = kmalloc(new_size, GFP_NOFS); 2892 if (unlikely(!extent_nis)) { 2893 ntfs_error(vol->sb, "Failed to allocate internal " 2894 "buffer during rollback.%s", es); 2895 mutex_unlock(&base_ni->extent_lock); 2896 NVolSetErrors(vol); 2897 goto rollback_error; 2898 } 2899 if (base_ni->nr_extents) { 2900 BUG_ON(!base_ni->ext.extent_ntfs_inos); 2901 memcpy(extent_nis, base_ni->ext.extent_ntfs_inos, 2902 new_size - 4 * sizeof(ntfs_inode*)); 2903 kfree(base_ni->ext.extent_ntfs_inos); 2904 } 2905 base_ni->ext.extent_ntfs_inos = extent_nis; 2906 } 2907 m->flags |= MFT_RECORD_IN_USE; 2908 m->sequence_number = old_seq_no; 2909 extent_nis[base_ni->nr_extents++] = ni; 2910 mutex_unlock(&base_ni->extent_lock); 2911 mark_mft_record_dirty(ni); 2912 return err; 2913 } 2914 #endif /* NTFS_RW */ 2915