1 /** 2 * mft.c - NTFS kernel mft record operations. Part of the Linux-NTFS project. 3 * 4 * Copyright (c) 2001-2005 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 } 97 err_out: 98 ni->page = NULL; 99 ni->page_ofs = 0; 100 return (void*)page; 101 } 102 103 /** 104 * map_mft_record - map, pin and lock an mft record 105 * @ni: ntfs inode whose MFT record to map 106 * 107 * First, take the mrec_lock semaphore. We might now be sleeping, while waiting 108 * for the semaphore if it was already locked by someone else. 109 * 110 * The page of the record is mapped using map_mft_record_page() before being 111 * returned to the caller. 112 * 113 * This in turn uses ntfs_map_page() to get the page containing the wanted mft 114 * record (it in turn calls read_cache_page() which reads it in from disk if 115 * necessary, increments the use count on the page so that it cannot disappear 116 * under us and returns a reference to the page cache page). 117 * 118 * If read_cache_page() invokes ntfs_readpage() to load the page from disk, it 119 * sets PG_locked and clears PG_uptodate on the page. Once I/O has completed 120 * and the post-read mst fixups on each mft record in the page have been 121 * performed, the page gets PG_uptodate set and PG_locked cleared (this is done 122 * in our asynchronous I/O completion handler end_buffer_read_mft_async()). 123 * ntfs_map_page() waits for PG_locked to become clear and checks if 124 * PG_uptodate is set and returns an error code if not. This provides 125 * sufficient protection against races when reading/using the page. 126 * 127 * However there is the write mapping to think about. Doing the above described 128 * checking here will be fine, because when initiating the write we will set 129 * PG_locked and clear PG_uptodate making sure nobody is touching the page 130 * contents. Doing the locking this way means that the commit to disk code in 131 * the page cache code paths is automatically sufficiently locked with us as 132 * we will not touch a page that has been locked or is not uptodate. The only 133 * locking problem then is them locking the page while we are accessing it. 134 * 135 * So that code will end up having to own the mrec_lock of all mft 136 * records/inodes present in the page before I/O can proceed. In that case we 137 * wouldn't need to bother with PG_locked and PG_uptodate as nobody will be 138 * accessing anything without owning the mrec_lock semaphore. But we do need 139 * to use them because of the read_cache_page() invocation and the code becomes 140 * so much simpler this way that it is well worth it. 141 * 142 * The mft record is now ours and we return a pointer to it. You need to check 143 * the returned pointer with IS_ERR() and if that is true, PTR_ERR() will return 144 * the error code. 145 * 146 * NOTE: Caller is responsible for setting the mft record dirty before calling 147 * unmap_mft_record(). This is obviously only necessary if the caller really 148 * modified the mft record... 149 * Q: Do we want to recycle one of the VFS inode state bits instead? 150 * A: No, the inode ones mean we want to change the mft record, not we want to 151 * write it out. 152 */ 153 MFT_RECORD *map_mft_record(ntfs_inode *ni) 154 { 155 MFT_RECORD *m; 156 157 ntfs_debug("Entering for mft_no 0x%lx.", ni->mft_no); 158 159 /* Make sure the ntfs inode doesn't go away. */ 160 atomic_inc(&ni->count); 161 162 /* Serialize access to this mft record. */ 163 down(&ni->mrec_lock); 164 165 m = map_mft_record_page(ni); 166 if (likely(!IS_ERR(m))) 167 return m; 168 169 up(&ni->mrec_lock); 170 atomic_dec(&ni->count); 171 ntfs_error(ni->vol->sb, "Failed with error code %lu.", -PTR_ERR(m)); 172 return m; 173 } 174 175 /** 176 * unmap_mft_record_page - unmap the page in which a specific mft record resides 177 * @ni: ntfs inode whose mft record page to unmap 178 * 179 * This unmaps the page in which the mft record of the ntfs inode @ni is 180 * situated and returns. This is a NOOP if highmem is not configured. 181 * 182 * The unmap happens via ntfs_unmap_page() which in turn decrements the use 183 * count on the page thus releasing it from the pinned state. 184 * 185 * We do not actually unmap the page from memory of course, as that will be 186 * done by the page cache code itself when memory pressure increases or 187 * whatever. 188 */ 189 static inline void unmap_mft_record_page(ntfs_inode *ni) 190 { 191 BUG_ON(!ni->page); 192 193 // TODO: If dirty, blah... 194 ntfs_unmap_page(ni->page); 195 ni->page = NULL; 196 ni->page_ofs = 0; 197 return; 198 } 199 200 /** 201 * unmap_mft_record - release a mapped mft record 202 * @ni: ntfs inode whose MFT record to unmap 203 * 204 * We release the page mapping and the mrec_lock mutex which unmaps the mft 205 * record and releases it for others to get hold of. We also release the ntfs 206 * inode by decrementing the ntfs inode reference count. 207 * 208 * NOTE: If caller has modified the mft record, it is imperative to set the mft 209 * record dirty BEFORE calling unmap_mft_record(). 210 */ 211 void unmap_mft_record(ntfs_inode *ni) 212 { 213 struct page *page = ni->page; 214 215 BUG_ON(!page); 216 217 ntfs_debug("Entering for mft_no 0x%lx.", ni->mft_no); 218 219 unmap_mft_record_page(ni); 220 up(&ni->mrec_lock); 221 atomic_dec(&ni->count); 222 /* 223 * If pure ntfs_inode, i.e. no vfs inode attached, we leave it to 224 * ntfs_clear_extent_inode() in the extent inode case, and to the 225 * caller in the non-extent, yet pure ntfs inode case, to do the actual 226 * tear down of all structures and freeing of all allocated memory. 227 */ 228 return; 229 } 230 231 /** 232 * map_extent_mft_record - load an extent inode and attach it to its base 233 * @base_ni: base ntfs inode 234 * @mref: mft reference of the extent inode to load 235 * @ntfs_ino: on successful return, pointer to the ntfs_inode structure 236 * 237 * Load the extent mft record @mref and attach it to its base inode @base_ni. 238 * Return the mapped extent mft record if IS_ERR(result) is false. Otherwise 239 * PTR_ERR(result) gives the negative error code. 240 * 241 * On successful return, @ntfs_ino contains a pointer to the ntfs_inode 242 * structure of the mapped extent inode. 243 */ 244 MFT_RECORD *map_extent_mft_record(ntfs_inode *base_ni, MFT_REF mref, 245 ntfs_inode **ntfs_ino) 246 { 247 MFT_RECORD *m; 248 ntfs_inode *ni = NULL; 249 ntfs_inode **extent_nis = NULL; 250 int i; 251 unsigned long mft_no = MREF(mref); 252 u16 seq_no = MSEQNO(mref); 253 BOOL destroy_ni = FALSE; 254 255 ntfs_debug("Mapping extent mft record 0x%lx (base mft record 0x%lx).", 256 mft_no, base_ni->mft_no); 257 /* Make sure the base ntfs inode doesn't go away. */ 258 atomic_inc(&base_ni->count); 259 /* 260 * Check if this extent inode has already been added to the base inode, 261 * in which case just return it. If not found, add it to the base 262 * inode before returning it. 263 */ 264 down(&base_ni->extent_lock); 265 if (base_ni->nr_extents > 0) { 266 extent_nis = base_ni->ext.extent_ntfs_inos; 267 for (i = 0; i < base_ni->nr_extents; i++) { 268 if (mft_no != extent_nis[i]->mft_no) 269 continue; 270 ni = extent_nis[i]; 271 /* Make sure the ntfs inode doesn't go away. */ 272 atomic_inc(&ni->count); 273 break; 274 } 275 } 276 if (likely(ni != NULL)) { 277 up(&base_ni->extent_lock); 278 atomic_dec(&base_ni->count); 279 /* We found the record; just have to map and return it. */ 280 m = map_mft_record(ni); 281 /* map_mft_record() has incremented this on success. */ 282 atomic_dec(&ni->count); 283 if (likely(!IS_ERR(m))) { 284 /* Verify the sequence number. */ 285 if (likely(le16_to_cpu(m->sequence_number) == seq_no)) { 286 ntfs_debug("Done 1."); 287 *ntfs_ino = ni; 288 return m; 289 } 290 unmap_mft_record(ni); 291 ntfs_error(base_ni->vol->sb, "Found stale extent mft " 292 "reference! Corrupt filesystem. " 293 "Run chkdsk."); 294 return ERR_PTR(-EIO); 295 } 296 map_err_out: 297 ntfs_error(base_ni->vol->sb, "Failed to map extent " 298 "mft record, error code %ld.", -PTR_ERR(m)); 299 return m; 300 } 301 /* Record wasn't there. Get a new ntfs inode and initialize it. */ 302 ni = ntfs_new_extent_inode(base_ni->vol->sb, mft_no); 303 if (unlikely(!ni)) { 304 up(&base_ni->extent_lock); 305 atomic_dec(&base_ni->count); 306 return ERR_PTR(-ENOMEM); 307 } 308 ni->vol = base_ni->vol; 309 ni->seq_no = seq_no; 310 ni->nr_extents = -1; 311 ni->ext.base_ntfs_ino = base_ni; 312 /* Now map the record. */ 313 m = map_mft_record(ni); 314 if (IS_ERR(m)) { 315 up(&base_ni->extent_lock); 316 atomic_dec(&base_ni->count); 317 ntfs_clear_extent_inode(ni); 318 goto map_err_out; 319 } 320 /* Verify the sequence number if it is present. */ 321 if (seq_no && (le16_to_cpu(m->sequence_number) != seq_no)) { 322 ntfs_error(base_ni->vol->sb, "Found stale extent mft " 323 "reference! Corrupt filesystem. Run chkdsk."); 324 destroy_ni = TRUE; 325 m = ERR_PTR(-EIO); 326 goto unm_err_out; 327 } 328 /* Attach extent inode to base inode, reallocating memory if needed. */ 329 if (!(base_ni->nr_extents & 3)) { 330 ntfs_inode **tmp; 331 int new_size = (base_ni->nr_extents + 4) * sizeof(ntfs_inode *); 332 333 tmp = (ntfs_inode **)kmalloc(new_size, GFP_NOFS); 334 if (unlikely(!tmp)) { 335 ntfs_error(base_ni->vol->sb, "Failed to allocate " 336 "internal buffer."); 337 destroy_ni = TRUE; 338 m = ERR_PTR(-ENOMEM); 339 goto unm_err_out; 340 } 341 if (base_ni->nr_extents) { 342 BUG_ON(!base_ni->ext.extent_ntfs_inos); 343 memcpy(tmp, base_ni->ext.extent_ntfs_inos, new_size - 344 4 * sizeof(ntfs_inode *)); 345 kfree(base_ni->ext.extent_ntfs_inos); 346 } 347 base_ni->ext.extent_ntfs_inos = tmp; 348 } 349 base_ni->ext.extent_ntfs_inos[base_ni->nr_extents++] = ni; 350 up(&base_ni->extent_lock); 351 atomic_dec(&base_ni->count); 352 ntfs_debug("Done 2."); 353 *ntfs_ino = ni; 354 return m; 355 unm_err_out: 356 unmap_mft_record(ni); 357 up(&base_ni->extent_lock); 358 atomic_dec(&base_ni->count); 359 /* 360 * If the extent inode was not attached to the base inode we need to 361 * release it or we will leak memory. 362 */ 363 if (destroy_ni) 364 ntfs_clear_extent_inode(ni); 365 return m; 366 } 367 368 #ifdef NTFS_RW 369 370 /** 371 * __mark_mft_record_dirty - set the mft record and the page containing it dirty 372 * @ni: ntfs inode describing the mapped mft record 373 * 374 * Internal function. Users should call mark_mft_record_dirty() instead. 375 * 376 * Set the mapped (extent) mft record of the (base or extent) ntfs inode @ni, 377 * as well as the page containing the mft record, dirty. Also, mark the base 378 * vfs inode dirty. This ensures that any changes to the mft record are 379 * written out to disk. 380 * 381 * NOTE: We only set I_DIRTY_SYNC and I_DIRTY_DATASYNC (and not I_DIRTY_PAGES) 382 * on the base vfs inode, because even though file data may have been modified, 383 * it is dirty in the inode meta data rather than the data page cache of the 384 * inode, and thus there are no data pages that need writing out. Therefore, a 385 * full mark_inode_dirty() is overkill. A mark_inode_dirty_sync(), on the 386 * other hand, is not sufficient, because I_DIRTY_DATASYNC needs to be set to 387 * ensure ->write_inode is called from generic_osync_inode() and this needs to 388 * happen or the file data would not necessarily hit the device synchronously, 389 * even though the vfs inode has the O_SYNC flag set. Also, I_DIRTY_DATASYNC 390 * simply "feels" better than just I_DIRTY_SYNC, since the file data has not 391 * actually hit the block device yet, which is not what I_DIRTY_SYNC on its own 392 * would suggest. 393 */ 394 void __mark_mft_record_dirty(ntfs_inode *ni) 395 { 396 ntfs_inode *base_ni; 397 398 ntfs_debug("Entering for inode 0x%lx.", ni->mft_no); 399 BUG_ON(NInoAttr(ni)); 400 mark_ntfs_record_dirty(ni->page, ni->page_ofs); 401 /* Determine the base vfs inode and mark it dirty, too. */ 402 down(&ni->extent_lock); 403 if (likely(ni->nr_extents >= 0)) 404 base_ni = ni; 405 else 406 base_ni = ni->ext.base_ntfs_ino; 407 up(&ni->extent_lock); 408 __mark_inode_dirty(VFS_I(base_ni), I_DIRTY_SYNC | I_DIRTY_DATASYNC); 409 } 410 411 static const char *ntfs_please_email = "Please email " 412 "linux-ntfs-dev@lists.sourceforge.net and say that you saw " 413 "this message. Thank you."; 414 415 /** 416 * ntfs_sync_mft_mirror_umount - synchronise an mft record to the mft mirror 417 * @vol: ntfs volume on which the mft record to synchronize resides 418 * @mft_no: mft record number of mft record to synchronize 419 * @m: mapped, mst protected (extent) mft record to synchronize 420 * 421 * Write the mapped, mst protected (extent) mft record @m with mft record 422 * number @mft_no to the mft mirror ($MFTMirr) of the ntfs volume @vol, 423 * bypassing the page cache and the $MFTMirr inode itself. 424 * 425 * This function is only for use at umount time when the mft mirror inode has 426 * already been disposed off. We BUG() if we are called while the mft mirror 427 * inode is still attached to the volume. 428 * 429 * On success return 0. On error return -errno. 430 * 431 * NOTE: This function is not implemented yet as I am not convinced it can 432 * actually be triggered considering the sequence of commits we do in super.c:: 433 * ntfs_put_super(). But just in case we provide this place holder as the 434 * alternative would be either to BUG() or to get a NULL pointer dereference 435 * and Oops. 436 */ 437 static int ntfs_sync_mft_mirror_umount(ntfs_volume *vol, 438 const unsigned long mft_no, MFT_RECORD *m) 439 { 440 BUG_ON(vol->mftmirr_ino); 441 ntfs_error(vol->sb, "Umount time mft mirror syncing is not " 442 "implemented yet. %s", ntfs_please_email); 443 return -EOPNOTSUPP; 444 } 445 446 /** 447 * ntfs_sync_mft_mirror - synchronize an mft record to the mft mirror 448 * @vol: ntfs volume on which the mft record to synchronize resides 449 * @mft_no: mft record number of mft record to synchronize 450 * @m: mapped, mst protected (extent) mft record to synchronize 451 * @sync: if true, wait for i/o completion 452 * 453 * Write the mapped, mst protected (extent) mft record @m with mft record 454 * number @mft_no to the mft mirror ($MFTMirr) of the ntfs volume @vol. 455 * 456 * On success return 0. On error return -errno and set the volume errors flag 457 * in the ntfs volume @vol. 458 * 459 * NOTE: We always perform synchronous i/o and ignore the @sync parameter. 460 * 461 * TODO: If @sync is false, want to do truly asynchronous i/o, i.e. just 462 * schedule i/o via ->writepage or do it via kntfsd or whatever. 463 */ 464 int ntfs_sync_mft_mirror(ntfs_volume *vol, const unsigned long mft_no, 465 MFT_RECORD *m, int sync) 466 { 467 struct page *page; 468 unsigned int blocksize = vol->sb->s_blocksize; 469 int max_bhs = vol->mft_record_size / blocksize; 470 struct buffer_head *bhs[max_bhs]; 471 struct buffer_head *bh, *head; 472 u8 *kmirr; 473 runlist_element *rl; 474 unsigned int block_start, block_end, m_start, m_end, page_ofs; 475 int i_bhs, nr_bhs, err = 0; 476 unsigned char blocksize_bits = vol->mftmirr_ino->i_blkbits; 477 478 ntfs_debug("Entering for inode 0x%lx.", mft_no); 479 BUG_ON(!max_bhs); 480 if (unlikely(!vol->mftmirr_ino)) { 481 /* This could happen during umount... */ 482 err = ntfs_sync_mft_mirror_umount(vol, mft_no, m); 483 if (likely(!err)) 484 return err; 485 goto err_out; 486 } 487 /* Get the page containing the mirror copy of the mft record @m. */ 488 page = ntfs_map_page(vol->mftmirr_ino->i_mapping, mft_no >> 489 (PAGE_CACHE_SHIFT - vol->mft_record_size_bits)); 490 if (IS_ERR(page)) { 491 ntfs_error(vol->sb, "Failed to map mft mirror page."); 492 err = PTR_ERR(page); 493 goto err_out; 494 } 495 lock_page(page); 496 BUG_ON(!PageUptodate(page)); 497 ClearPageUptodate(page); 498 /* Offset of the mft mirror record inside the page. */ 499 page_ofs = (mft_no << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK; 500 /* The address in the page of the mirror copy of the mft record @m. */ 501 kmirr = page_address(page) + page_ofs; 502 /* Copy the mst protected mft record to the mirror. */ 503 memcpy(kmirr, m, vol->mft_record_size); 504 /* Create uptodate buffers if not present. */ 505 if (unlikely(!page_has_buffers(page))) { 506 struct buffer_head *tail; 507 508 bh = head = alloc_page_buffers(page, blocksize, 1); 509 do { 510 set_buffer_uptodate(bh); 511 tail = bh; 512 bh = bh->b_this_page; 513 } while (bh); 514 tail->b_this_page = head; 515 attach_page_buffers(page, head); 516 } 517 bh = head = page_buffers(page); 518 BUG_ON(!bh); 519 rl = NULL; 520 nr_bhs = 0; 521 block_start = 0; 522 m_start = kmirr - (u8*)page_address(page); 523 m_end = m_start + vol->mft_record_size; 524 do { 525 block_end = block_start + blocksize; 526 /* If the buffer is outside the mft record, skip it. */ 527 if (block_end <= m_start) 528 continue; 529 if (unlikely(block_start >= m_end)) 530 break; 531 /* Need to map the buffer if it is not mapped already. */ 532 if (unlikely(!buffer_mapped(bh))) { 533 VCN vcn; 534 LCN lcn; 535 unsigned int vcn_ofs; 536 537 bh->b_bdev = vol->sb->s_bdev; 538 /* Obtain the vcn and offset of the current block. */ 539 vcn = ((VCN)mft_no << vol->mft_record_size_bits) + 540 (block_start - m_start); 541 vcn_ofs = vcn & vol->cluster_size_mask; 542 vcn >>= vol->cluster_size_bits; 543 if (!rl) { 544 down_read(&NTFS_I(vol->mftmirr_ino)-> 545 runlist.lock); 546 rl = NTFS_I(vol->mftmirr_ino)->runlist.rl; 547 /* 548 * $MFTMirr always has the whole of its runlist 549 * in memory. 550 */ 551 BUG_ON(!rl); 552 } 553 /* Seek to element containing target vcn. */ 554 while (rl->length && rl[1].vcn <= vcn) 555 rl++; 556 lcn = ntfs_rl_vcn_to_lcn(rl, vcn); 557 /* For $MFTMirr, only lcn >= 0 is a successful remap. */ 558 if (likely(lcn >= 0)) { 559 /* Setup buffer head to correct block. */ 560 bh->b_blocknr = ((lcn << 561 vol->cluster_size_bits) + 562 vcn_ofs) >> blocksize_bits; 563 set_buffer_mapped(bh); 564 } else { 565 bh->b_blocknr = -1; 566 ntfs_error(vol->sb, "Cannot write mft mirror " 567 "record 0x%lx because its " 568 "location on disk could not " 569 "be determined (error code " 570 "%lli).", mft_no, 571 (long long)lcn); 572 err = -EIO; 573 } 574 } 575 BUG_ON(!buffer_uptodate(bh)); 576 BUG_ON(!nr_bhs && (m_start != block_start)); 577 BUG_ON(nr_bhs >= max_bhs); 578 bhs[nr_bhs++] = bh; 579 BUG_ON((nr_bhs >= max_bhs) && (m_end != block_end)); 580 } while (block_start = block_end, (bh = bh->b_this_page) != head); 581 if (unlikely(rl)) 582 up_read(&NTFS_I(vol->mftmirr_ino)->runlist.lock); 583 if (likely(!err)) { 584 /* Lock buffers and start synchronous write i/o on them. */ 585 for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) { 586 struct buffer_head *tbh = bhs[i_bhs]; 587 588 if (unlikely(test_set_buffer_locked(tbh))) 589 BUG(); 590 BUG_ON(!buffer_uptodate(tbh)); 591 clear_buffer_dirty(tbh); 592 get_bh(tbh); 593 tbh->b_end_io = end_buffer_write_sync; 594 submit_bh(WRITE, tbh); 595 } 596 /* Wait on i/o completion of buffers. */ 597 for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) { 598 struct buffer_head *tbh = bhs[i_bhs]; 599 600 wait_on_buffer(tbh); 601 if (unlikely(!buffer_uptodate(tbh))) { 602 err = -EIO; 603 /* 604 * Set the buffer uptodate so the page and 605 * buffer states do not become out of sync. 606 */ 607 set_buffer_uptodate(tbh); 608 } 609 } 610 } else /* if (unlikely(err)) */ { 611 /* Clean the buffers. */ 612 for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) 613 clear_buffer_dirty(bhs[i_bhs]); 614 } 615 /* Current state: all buffers are clean, unlocked, and uptodate. */ 616 /* Remove the mst protection fixups again. */ 617 post_write_mst_fixup((NTFS_RECORD*)kmirr); 618 flush_dcache_page(page); 619 SetPageUptodate(page); 620 unlock_page(page); 621 ntfs_unmap_page(page); 622 if (likely(!err)) { 623 ntfs_debug("Done."); 624 } else { 625 ntfs_error(vol->sb, "I/O error while writing mft mirror " 626 "record 0x%lx!", mft_no); 627 err_out: 628 ntfs_error(vol->sb, "Failed to synchronize $MFTMirr (error " 629 "code %i). Volume will be left marked dirty " 630 "on umount. Run ntfsfix on the partition " 631 "after umounting to correct this.", -err); 632 NVolSetErrors(vol); 633 } 634 return err; 635 } 636 637 /** 638 * write_mft_record_nolock - write out a mapped (extent) mft record 639 * @ni: ntfs inode describing the mapped (extent) mft record 640 * @m: mapped (extent) mft record to write 641 * @sync: if true, wait for i/o completion 642 * 643 * Write the mapped (extent) mft record @m described by the (regular or extent) 644 * ntfs inode @ni to backing store. If the mft record @m has a counterpart in 645 * the mft mirror, that is also updated. 646 * 647 * We only write the mft record if the ntfs inode @ni is dirty and the first 648 * buffer belonging to its mft record is dirty, too. We ignore the dirty state 649 * of subsequent buffers because we could have raced with 650 * fs/ntfs/aops.c::mark_ntfs_record_dirty(). 651 * 652 * On success, clean the mft record and return 0. On error, leave the mft 653 * record dirty and return -errno. The caller should call make_bad_inode() on 654 * the base inode to ensure no more access happens to this inode. We do not do 655 * it here as the caller may want to finish writing other extent mft records 656 * first to minimize on-disk metadata inconsistencies. 657 * 658 * NOTE: We always perform synchronous i/o and ignore the @sync parameter. 659 * However, if the mft record has a counterpart in the mft mirror and @sync is 660 * true, we write the mft record, wait for i/o completion, and only then write 661 * the mft mirror copy. This ensures that if the system crashes either the mft 662 * or the mft mirror will contain a self-consistent mft record @m. If @sync is 663 * false on the other hand, we start i/o on both and then wait for completion 664 * on them. This provides a speedup but no longer guarantees that you will end 665 * up with a self-consistent mft record in the case of a crash but if you asked 666 * for asynchronous writing you probably do not care about that anyway. 667 * 668 * TODO: If @sync is false, want to do truly asynchronous i/o, i.e. just 669 * schedule i/o via ->writepage or do it via kntfsd or whatever. 670 */ 671 int write_mft_record_nolock(ntfs_inode *ni, MFT_RECORD *m, int sync) 672 { 673 ntfs_volume *vol = ni->vol; 674 struct page *page = ni->page; 675 unsigned char blocksize_bits = vol->mft_ino->i_blkbits; 676 unsigned int blocksize = 1 << blocksize_bits; 677 int max_bhs = vol->mft_record_size / blocksize; 678 struct buffer_head *bhs[max_bhs]; 679 struct buffer_head *bh, *head; 680 runlist_element *rl; 681 unsigned int block_start, block_end, m_start, m_end; 682 int i_bhs, nr_bhs, err = 0; 683 684 ntfs_debug("Entering for inode 0x%lx.", ni->mft_no); 685 BUG_ON(NInoAttr(ni)); 686 BUG_ON(!max_bhs); 687 BUG_ON(!PageLocked(page)); 688 /* 689 * If the ntfs_inode is clean no need to do anything. If it is dirty, 690 * mark it as clean now so that it can be redirtied later on if needed. 691 * There is no danger of races since the caller is holding the locks 692 * for the mft record @m and the page it is in. 693 */ 694 if (!NInoTestClearDirty(ni)) 695 goto done; 696 bh = head = page_buffers(page); 697 BUG_ON(!bh); 698 rl = NULL; 699 nr_bhs = 0; 700 block_start = 0; 701 m_start = ni->page_ofs; 702 m_end = m_start + vol->mft_record_size; 703 do { 704 block_end = block_start + blocksize; 705 /* If the buffer is outside the mft record, skip it. */ 706 if (block_end <= m_start) 707 continue; 708 if (unlikely(block_start >= m_end)) 709 break; 710 /* 711 * If this block is not the first one in the record, we ignore 712 * the buffer's dirty state because we could have raced with a 713 * parallel mark_ntfs_record_dirty(). 714 */ 715 if (block_start == m_start) { 716 /* This block is the first one in the record. */ 717 if (!buffer_dirty(bh)) { 718 BUG_ON(nr_bhs); 719 /* Clean records are not written out. */ 720 break; 721 } 722 } 723 /* Need to map the buffer if it is not mapped already. */ 724 if (unlikely(!buffer_mapped(bh))) { 725 VCN vcn; 726 LCN lcn; 727 unsigned int vcn_ofs; 728 729 bh->b_bdev = vol->sb->s_bdev; 730 /* Obtain the vcn and offset of the current block. */ 731 vcn = ((VCN)ni->mft_no << vol->mft_record_size_bits) + 732 (block_start - m_start); 733 vcn_ofs = vcn & vol->cluster_size_mask; 734 vcn >>= vol->cluster_size_bits; 735 if (!rl) { 736 down_read(&NTFS_I(vol->mft_ino)->runlist.lock); 737 rl = NTFS_I(vol->mft_ino)->runlist.rl; 738 BUG_ON(!rl); 739 } 740 /* Seek to element containing target vcn. */ 741 while (rl->length && rl[1].vcn <= vcn) 742 rl++; 743 lcn = ntfs_rl_vcn_to_lcn(rl, vcn); 744 /* For $MFT, only lcn >= 0 is a successful remap. */ 745 if (likely(lcn >= 0)) { 746 /* Setup buffer head to correct block. */ 747 bh->b_blocknr = ((lcn << 748 vol->cluster_size_bits) + 749 vcn_ofs) >> blocksize_bits; 750 set_buffer_mapped(bh); 751 } else { 752 bh->b_blocknr = -1; 753 ntfs_error(vol->sb, "Cannot write mft record " 754 "0x%lx because its location " 755 "on disk could not be " 756 "determined (error code %lli).", 757 ni->mft_no, (long long)lcn); 758 err = -EIO; 759 } 760 } 761 BUG_ON(!buffer_uptodate(bh)); 762 BUG_ON(!nr_bhs && (m_start != block_start)); 763 BUG_ON(nr_bhs >= max_bhs); 764 bhs[nr_bhs++] = bh; 765 BUG_ON((nr_bhs >= max_bhs) && (m_end != block_end)); 766 } while (block_start = block_end, (bh = bh->b_this_page) != head); 767 if (unlikely(rl)) 768 up_read(&NTFS_I(vol->mft_ino)->runlist.lock); 769 if (!nr_bhs) 770 goto done; 771 if (unlikely(err)) 772 goto cleanup_out; 773 /* Apply the mst protection fixups. */ 774 err = pre_write_mst_fixup((NTFS_RECORD*)m, vol->mft_record_size); 775 if (err) { 776 ntfs_error(vol->sb, "Failed to apply mst fixups!"); 777 goto cleanup_out; 778 } 779 flush_dcache_mft_record_page(ni); 780 /* Lock buffers and start synchronous write i/o on them. */ 781 for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) { 782 struct buffer_head *tbh = bhs[i_bhs]; 783 784 if (unlikely(test_set_buffer_locked(tbh))) 785 BUG(); 786 BUG_ON(!buffer_uptodate(tbh)); 787 clear_buffer_dirty(tbh); 788 get_bh(tbh); 789 tbh->b_end_io = end_buffer_write_sync; 790 submit_bh(WRITE, tbh); 791 } 792 /* Synchronize the mft mirror now if not @sync. */ 793 if (!sync && ni->mft_no < vol->mftmirr_size) 794 ntfs_sync_mft_mirror(vol, ni->mft_no, m, sync); 795 /* Wait on i/o completion of buffers. */ 796 for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) { 797 struct buffer_head *tbh = bhs[i_bhs]; 798 799 wait_on_buffer(tbh); 800 if (unlikely(!buffer_uptodate(tbh))) { 801 err = -EIO; 802 /* 803 * Set the buffer uptodate so the page and buffer 804 * states do not become out of sync. 805 */ 806 if (PageUptodate(page)) 807 set_buffer_uptodate(tbh); 808 } 809 } 810 /* If @sync, now synchronize the mft mirror. */ 811 if (sync && ni->mft_no < vol->mftmirr_size) 812 ntfs_sync_mft_mirror(vol, ni->mft_no, m, sync); 813 /* Remove the mst protection fixups again. */ 814 post_write_mst_fixup((NTFS_RECORD*)m); 815 flush_dcache_mft_record_page(ni); 816 if (unlikely(err)) { 817 /* I/O error during writing. This is really bad! */ 818 ntfs_error(vol->sb, "I/O error while writing mft record " 819 "0x%lx! Marking base inode as bad. You " 820 "should unmount the volume and run chkdsk.", 821 ni->mft_no); 822 goto err_out; 823 } 824 done: 825 ntfs_debug("Done."); 826 return 0; 827 cleanup_out: 828 /* Clean the buffers. */ 829 for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) 830 clear_buffer_dirty(bhs[i_bhs]); 831 err_out: 832 /* 833 * Current state: all buffers are clean, unlocked, and uptodate. 834 * The caller should mark the base inode as bad so that no more i/o 835 * happens. ->clear_inode() will still be invoked so all extent inodes 836 * and other allocated memory will be freed. 837 */ 838 if (err == -ENOMEM) { 839 ntfs_error(vol->sb, "Not enough memory to write mft record. " 840 "Redirtying so the write is retried later."); 841 mark_mft_record_dirty(ni); 842 err = 0; 843 } else 844 NVolSetErrors(vol); 845 return err; 846 } 847 848 /** 849 * ntfs_may_write_mft_record - check if an mft record may be written out 850 * @vol: [IN] ntfs volume on which the mft record to check resides 851 * @mft_no: [IN] mft record number of the mft record to check 852 * @m: [IN] mapped mft record to check 853 * @locked_ni: [OUT] caller has to unlock this ntfs inode if one is returned 854 * 855 * Check if the mapped (base or extent) mft record @m with mft record number 856 * @mft_no belonging to the ntfs volume @vol may be written out. If necessary 857 * and possible the ntfs inode of the mft record is locked and the base vfs 858 * inode is pinned. The locked ntfs inode is then returned in @locked_ni. The 859 * caller is responsible for unlocking the ntfs inode and unpinning the base 860 * vfs inode. 861 * 862 * Return TRUE if the mft record may be written out and FALSE if not. 863 * 864 * The caller has locked the page and cleared the uptodate flag on it which 865 * means that we can safely write out any dirty mft records that do not have 866 * their inodes in icache as determined by ilookup5() as anyone 867 * opening/creating such an inode would block when attempting to map the mft 868 * record in read_cache_page() until we are finished with the write out. 869 * 870 * Here is a description of the tests we perform: 871 * 872 * If the inode is found in icache we know the mft record must be a base mft 873 * record. If it is dirty, we do not write it and return FALSE as the vfs 874 * inode write paths will result in the access times being updated which would 875 * cause the base mft record to be redirtied and written out again. (We know 876 * the access time update will modify the base mft record because Windows 877 * chkdsk complains if the standard information attribute is not in the base 878 * mft record.) 879 * 880 * If the inode is in icache and not dirty, we attempt to lock the mft record 881 * and if we find the lock was already taken, it is not safe to write the mft 882 * record and we return FALSE. 883 * 884 * If we manage to obtain the lock we have exclusive access to the mft record, 885 * which also allows us safe writeout of the mft record. We then set 886 * @locked_ni to the locked ntfs inode and return TRUE. 887 * 888 * Note we cannot just lock the mft record and sleep while waiting for the lock 889 * because this would deadlock due to lock reversal (normally the mft record is 890 * locked before the page is locked but we already have the page locked here 891 * when we try to lock the mft record). 892 * 893 * If the inode is not in icache we need to perform further checks. 894 * 895 * If the mft record is not a FILE record or it is a base mft record, we can 896 * safely write it and return TRUE. 897 * 898 * We now know the mft record is an extent mft record. We check if the inode 899 * corresponding to its base mft record is in icache and obtain a reference to 900 * it if it is. If it is not, we can safely write it and return TRUE. 901 * 902 * We now have the base inode for the extent mft record. We check if it has an 903 * ntfs inode for the extent mft record attached and if not it is safe to write 904 * the extent mft record and we return TRUE. 905 * 906 * The ntfs inode for the extent mft record is attached to the base inode so we 907 * attempt to lock the extent mft record and if we find the lock was already 908 * taken, it is not safe to write the extent mft record and we return FALSE. 909 * 910 * If we manage to obtain the lock we have exclusive access to the extent mft 911 * record, which also allows us safe writeout of the extent mft record. We 912 * set the ntfs inode of the extent mft record clean and then set @locked_ni to 913 * the now locked ntfs inode and return TRUE. 914 * 915 * Note, the reason for actually writing dirty mft records here and not just 916 * relying on the vfs inode dirty code paths is that we can have mft records 917 * modified without them ever having actual inodes in memory. Also we can have 918 * dirty mft records with clean ntfs inodes in memory. None of the described 919 * cases would result in the dirty mft records being written out if we only 920 * relied on the vfs inode dirty code paths. And these cases can really occur 921 * during allocation of new mft records and in particular when the 922 * initialized_size of the $MFT/$DATA attribute is extended and the new space 923 * is initialized using ntfs_mft_record_format(). The clean inode can then 924 * appear if the mft record is reused for a new inode before it got written 925 * out. 926 */ 927 BOOL ntfs_may_write_mft_record(ntfs_volume *vol, const unsigned long mft_no, 928 const MFT_RECORD *m, ntfs_inode **locked_ni) 929 { 930 struct super_block *sb = vol->sb; 931 struct inode *mft_vi = vol->mft_ino; 932 struct inode *vi; 933 ntfs_inode *ni, *eni, **extent_nis; 934 int i; 935 ntfs_attr na; 936 937 ntfs_debug("Entering for inode 0x%lx.", mft_no); 938 /* 939 * Normally we do not return a locked inode so set @locked_ni to NULL. 940 */ 941 BUG_ON(!locked_ni); 942 *locked_ni = NULL; 943 /* 944 * Check if the inode corresponding to this mft record is in the VFS 945 * inode cache and obtain a reference to it if it is. 946 */ 947 ntfs_debug("Looking for inode 0x%lx in icache.", mft_no); 948 na.mft_no = mft_no; 949 na.name = NULL; 950 na.name_len = 0; 951 na.type = AT_UNUSED; 952 /* 953 * Optimize inode 0, i.e. $MFT itself, since we have it in memory and 954 * we get here for it rather often. 955 */ 956 if (!mft_no) { 957 /* Balance the below iput(). */ 958 vi = igrab(mft_vi); 959 BUG_ON(vi != mft_vi); 960 } else { 961 /* 962 * Have to use ilookup5_nowait() since ilookup5() waits for the 963 * inode lock which causes ntfs to deadlock when a concurrent 964 * inode write via the inode dirty code paths and the page 965 * dirty code path of the inode dirty code path when writing 966 * $MFT occurs. 967 */ 968 vi = ilookup5_nowait(sb, mft_no, (test_t)ntfs_test_inode, &na); 969 } 970 if (vi) { 971 ntfs_debug("Base inode 0x%lx is in icache.", mft_no); 972 /* The inode is in icache. */ 973 ni = NTFS_I(vi); 974 /* Take a reference to the ntfs inode. */ 975 atomic_inc(&ni->count); 976 /* If the inode is dirty, do not write this record. */ 977 if (NInoDirty(ni)) { 978 ntfs_debug("Inode 0x%lx is dirty, do not write it.", 979 mft_no); 980 atomic_dec(&ni->count); 981 iput(vi); 982 return FALSE; 983 } 984 ntfs_debug("Inode 0x%lx is not dirty.", mft_no); 985 /* The inode is not dirty, try to take the mft record lock. */ 986 if (unlikely(down_trylock(&ni->mrec_lock))) { 987 ntfs_debug("Mft record 0x%lx is already locked, do " 988 "not write it.", mft_no); 989 atomic_dec(&ni->count); 990 iput(vi); 991 return FALSE; 992 } 993 ntfs_debug("Managed to lock mft record 0x%lx, write it.", 994 mft_no); 995 /* 996 * The write has to occur while we hold the mft record lock so 997 * return the locked ntfs inode. 998 */ 999 *locked_ni = ni; 1000 return TRUE; 1001 } 1002 ntfs_debug("Inode 0x%lx is not in icache.", mft_no); 1003 /* The inode is not in icache. */ 1004 /* Write the record if it is not a mft record (type "FILE"). */ 1005 if (!ntfs_is_mft_record(m->magic)) { 1006 ntfs_debug("Mft record 0x%lx is not a FILE record, write it.", 1007 mft_no); 1008 return TRUE; 1009 } 1010 /* Write the mft record if it is a base inode. */ 1011 if (!m->base_mft_record) { 1012 ntfs_debug("Mft record 0x%lx is a base record, write it.", 1013 mft_no); 1014 return TRUE; 1015 } 1016 /* 1017 * This is an extent mft record. Check if the inode corresponding to 1018 * its base mft record is in icache and obtain a reference to it if it 1019 * is. 1020 */ 1021 na.mft_no = MREF_LE(m->base_mft_record); 1022 ntfs_debug("Mft record 0x%lx is an extent record. Looking for base " 1023 "inode 0x%lx in icache.", mft_no, na.mft_no); 1024 if (!na.mft_no) { 1025 /* Balance the below iput(). */ 1026 vi = igrab(mft_vi); 1027 BUG_ON(vi != mft_vi); 1028 } else 1029 vi = ilookup5_nowait(sb, na.mft_no, (test_t)ntfs_test_inode, 1030 &na); 1031 if (!vi) { 1032 /* 1033 * The base inode is not in icache, write this extent mft 1034 * record. 1035 */ 1036 ntfs_debug("Base inode 0x%lx is not in icache, write the " 1037 "extent record.", na.mft_no); 1038 return TRUE; 1039 } 1040 ntfs_debug("Base inode 0x%lx is in icache.", na.mft_no); 1041 /* 1042 * The base inode is in icache. Check if it has the extent inode 1043 * corresponding to this extent mft record attached. 1044 */ 1045 ni = NTFS_I(vi); 1046 down(&ni->extent_lock); 1047 if (ni->nr_extents <= 0) { 1048 /* 1049 * The base inode has no attached extent inodes, write this 1050 * extent mft record. 1051 */ 1052 up(&ni->extent_lock); 1053 iput(vi); 1054 ntfs_debug("Base inode 0x%lx has no attached extent inodes, " 1055 "write the extent record.", na.mft_no); 1056 return TRUE; 1057 } 1058 /* Iterate over the attached extent inodes. */ 1059 extent_nis = ni->ext.extent_ntfs_inos; 1060 for (eni = NULL, i = 0; i < ni->nr_extents; ++i) { 1061 if (mft_no == extent_nis[i]->mft_no) { 1062 /* 1063 * Found the extent inode corresponding to this extent 1064 * mft record. 1065 */ 1066 eni = extent_nis[i]; 1067 break; 1068 } 1069 } 1070 /* 1071 * If the extent inode was not attached to the base inode, write this 1072 * extent mft record. 1073 */ 1074 if (!eni) { 1075 up(&ni->extent_lock); 1076 iput(vi); 1077 ntfs_debug("Extent inode 0x%lx is not attached to its base " 1078 "inode 0x%lx, write the extent record.", 1079 mft_no, na.mft_no); 1080 return TRUE; 1081 } 1082 ntfs_debug("Extent inode 0x%lx is attached to its base inode 0x%lx.", 1083 mft_no, na.mft_no); 1084 /* Take a reference to the extent ntfs inode. */ 1085 atomic_inc(&eni->count); 1086 up(&ni->extent_lock); 1087 /* 1088 * Found the extent inode coresponding to this extent mft record. 1089 * Try to take the mft record lock. 1090 */ 1091 if (unlikely(down_trylock(&eni->mrec_lock))) { 1092 atomic_dec(&eni->count); 1093 iput(vi); 1094 ntfs_debug("Extent mft record 0x%lx is already locked, do " 1095 "not write it.", mft_no); 1096 return FALSE; 1097 } 1098 ntfs_debug("Managed to lock extent mft record 0x%lx, write it.", 1099 mft_no); 1100 if (NInoTestClearDirty(eni)) 1101 ntfs_debug("Extent inode 0x%lx is dirty, marking it clean.", 1102 mft_no); 1103 /* 1104 * The write has to occur while we hold the mft record lock so return 1105 * the locked extent ntfs inode. 1106 */ 1107 *locked_ni = eni; 1108 return TRUE; 1109 } 1110 1111 static const char *es = " Leaving inconsistent metadata. Unmount and run " 1112 "chkdsk."; 1113 1114 /** 1115 * ntfs_mft_bitmap_find_and_alloc_free_rec_nolock - see name 1116 * @vol: volume on which to search for a free mft record 1117 * @base_ni: open base inode if allocating an extent mft record or NULL 1118 * 1119 * Search for a free mft record in the mft bitmap attribute on the ntfs volume 1120 * @vol. 1121 * 1122 * If @base_ni is NULL start the search at the default allocator position. 1123 * 1124 * If @base_ni is not NULL start the search at the mft record after the base 1125 * mft record @base_ni. 1126 * 1127 * Return the free mft record on success and -errno on error. An error code of 1128 * -ENOSPC means that there are no free mft records in the currently 1129 * initialized mft bitmap. 1130 * 1131 * Locking: Caller must hold vol->mftbmp_lock for writing. 1132 */ 1133 static int ntfs_mft_bitmap_find_and_alloc_free_rec_nolock(ntfs_volume *vol, 1134 ntfs_inode *base_ni) 1135 { 1136 s64 pass_end, ll, data_pos, pass_start, ofs, bit; 1137 unsigned long flags; 1138 struct address_space *mftbmp_mapping; 1139 u8 *buf, *byte; 1140 struct page *page; 1141 unsigned int page_ofs, size; 1142 u8 pass, b; 1143 1144 ntfs_debug("Searching for free mft record in the currently " 1145 "initialized mft bitmap."); 1146 mftbmp_mapping = vol->mftbmp_ino->i_mapping; 1147 /* 1148 * Set the end of the pass making sure we do not overflow the mft 1149 * bitmap. 1150 */ 1151 read_lock_irqsave(&NTFS_I(vol->mft_ino)->size_lock, flags); 1152 pass_end = NTFS_I(vol->mft_ino)->allocated_size >> 1153 vol->mft_record_size_bits; 1154 read_unlock_irqrestore(&NTFS_I(vol->mft_ino)->size_lock, flags); 1155 read_lock_irqsave(&NTFS_I(vol->mftbmp_ino)->size_lock, flags); 1156 ll = NTFS_I(vol->mftbmp_ino)->initialized_size << 3; 1157 read_unlock_irqrestore(&NTFS_I(vol->mftbmp_ino)->size_lock, flags); 1158 if (pass_end > ll) 1159 pass_end = ll; 1160 pass = 1; 1161 if (!base_ni) 1162 data_pos = vol->mft_data_pos; 1163 else 1164 data_pos = base_ni->mft_no + 1; 1165 if (data_pos < 24) 1166 data_pos = 24; 1167 if (data_pos >= pass_end) { 1168 data_pos = 24; 1169 pass = 2; 1170 /* This happens on a freshly formatted volume. */ 1171 if (data_pos >= pass_end) 1172 return -ENOSPC; 1173 } 1174 pass_start = data_pos; 1175 ntfs_debug("Starting bitmap search: pass %u, pass_start 0x%llx, " 1176 "pass_end 0x%llx, data_pos 0x%llx.", pass, 1177 (long long)pass_start, (long long)pass_end, 1178 (long long)data_pos); 1179 /* Loop until a free mft record is found. */ 1180 for (; pass <= 2;) { 1181 /* Cap size to pass_end. */ 1182 ofs = data_pos >> 3; 1183 page_ofs = ofs & ~PAGE_CACHE_MASK; 1184 size = PAGE_CACHE_SIZE - page_ofs; 1185 ll = ((pass_end + 7) >> 3) - ofs; 1186 if (size > ll) 1187 size = ll; 1188 size <<= 3; 1189 /* 1190 * If we are still within the active pass, search the next page 1191 * for a zero bit. 1192 */ 1193 if (size) { 1194 page = ntfs_map_page(mftbmp_mapping, 1195 ofs >> PAGE_CACHE_SHIFT); 1196 if (unlikely(IS_ERR(page))) { 1197 ntfs_error(vol->sb, "Failed to read mft " 1198 "bitmap, aborting."); 1199 return PTR_ERR(page); 1200 } 1201 buf = (u8*)page_address(page) + page_ofs; 1202 bit = data_pos & 7; 1203 data_pos &= ~7ull; 1204 ntfs_debug("Before inner for loop: size 0x%x, " 1205 "data_pos 0x%llx, bit 0x%llx", size, 1206 (long long)data_pos, (long long)bit); 1207 for (; bit < size && data_pos + bit < pass_end; 1208 bit &= ~7ull, bit += 8) { 1209 byte = buf + (bit >> 3); 1210 if (*byte == 0xff) 1211 continue; 1212 b = ffz((unsigned long)*byte); 1213 if (b < 8 && b >= (bit & 7)) { 1214 ll = data_pos + (bit & ~7ull) + b; 1215 if (unlikely(ll > (1ll << 32))) { 1216 ntfs_unmap_page(page); 1217 return -ENOSPC; 1218 } 1219 *byte |= 1 << b; 1220 flush_dcache_page(page); 1221 set_page_dirty(page); 1222 ntfs_unmap_page(page); 1223 ntfs_debug("Done. (Found and " 1224 "allocated mft record " 1225 "0x%llx.)", 1226 (long long)ll); 1227 return ll; 1228 } 1229 } 1230 ntfs_debug("After inner for loop: size 0x%x, " 1231 "data_pos 0x%llx, bit 0x%llx", size, 1232 (long long)data_pos, (long long)bit); 1233 data_pos += size; 1234 ntfs_unmap_page(page); 1235 /* 1236 * If the end of the pass has not been reached yet, 1237 * continue searching the mft bitmap for a zero bit. 1238 */ 1239 if (data_pos < pass_end) 1240 continue; 1241 } 1242 /* Do the next pass. */ 1243 if (++pass == 2) { 1244 /* 1245 * Starting the second pass, in which we scan the first 1246 * part of the zone which we omitted earlier. 1247 */ 1248 pass_end = pass_start; 1249 data_pos = pass_start = 24; 1250 ntfs_debug("pass %i, pass_start 0x%llx, pass_end " 1251 "0x%llx.", pass, (long long)pass_start, 1252 (long long)pass_end); 1253 if (data_pos >= pass_end) 1254 break; 1255 } 1256 } 1257 /* No free mft records in currently initialized mft bitmap. */ 1258 ntfs_debug("Done. (No free mft records left in currently initialized " 1259 "mft bitmap.)"); 1260 return -ENOSPC; 1261 } 1262 1263 /** 1264 * ntfs_mft_bitmap_extend_allocation_nolock - extend mft bitmap by a cluster 1265 * @vol: volume on which to extend the mft bitmap attribute 1266 * 1267 * Extend the mft bitmap attribute on the ntfs volume @vol by one cluster. 1268 * 1269 * Note: Only changes allocated_size, i.e. does not touch initialized_size or 1270 * data_size. 1271 * 1272 * Return 0 on success and -errno on error. 1273 * 1274 * Locking: - Caller must hold vol->mftbmp_lock for writing. 1275 * - This function takes NTFS_I(vol->mftbmp_ino)->runlist.lock for 1276 * writing and releases it before returning. 1277 * - This function takes vol->lcnbmp_lock for writing and releases it 1278 * before returning. 1279 */ 1280 static int ntfs_mft_bitmap_extend_allocation_nolock(ntfs_volume *vol) 1281 { 1282 LCN lcn; 1283 s64 ll; 1284 unsigned long flags; 1285 struct page *page; 1286 ntfs_inode *mft_ni, *mftbmp_ni; 1287 runlist_element *rl, *rl2 = NULL; 1288 ntfs_attr_search_ctx *ctx = NULL; 1289 MFT_RECORD *mrec; 1290 ATTR_RECORD *a = NULL; 1291 int ret, mp_size; 1292 u32 old_alen = 0; 1293 u8 *b, tb; 1294 struct { 1295 u8 added_cluster:1; 1296 u8 added_run:1; 1297 u8 mp_rebuilt:1; 1298 } status = { 0, 0, 0 }; 1299 1300 ntfs_debug("Extending mft bitmap allocation."); 1301 mft_ni = NTFS_I(vol->mft_ino); 1302 mftbmp_ni = NTFS_I(vol->mftbmp_ino); 1303 /* 1304 * Determine the last lcn of the mft bitmap. The allocated size of the 1305 * mft bitmap cannot be zero so we are ok to do this. 1306 */ 1307 down_write(&mftbmp_ni->runlist.lock); 1308 read_lock_irqsave(&mftbmp_ni->size_lock, flags); 1309 ll = mftbmp_ni->allocated_size; 1310 read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 1311 rl = ntfs_attr_find_vcn_nolock(mftbmp_ni, 1312 (ll - 1) >> vol->cluster_size_bits, NULL); 1313 if (unlikely(IS_ERR(rl) || !rl->length || rl->lcn < 0)) { 1314 up_write(&mftbmp_ni->runlist.lock); 1315 ntfs_error(vol->sb, "Failed to determine last allocated " 1316 "cluster of mft bitmap attribute."); 1317 if (!IS_ERR(rl)) 1318 ret = -EIO; 1319 else 1320 ret = PTR_ERR(rl); 1321 return ret; 1322 } 1323 lcn = rl->lcn + rl->length; 1324 ntfs_debug("Last lcn of mft bitmap attribute is 0x%llx.", 1325 (long long)lcn); 1326 /* 1327 * Attempt to get the cluster following the last allocated cluster by 1328 * hand as it may be in the MFT zone so the allocator would not give it 1329 * to us. 1330 */ 1331 ll = lcn >> 3; 1332 page = ntfs_map_page(vol->lcnbmp_ino->i_mapping, 1333 ll >> PAGE_CACHE_SHIFT); 1334 if (IS_ERR(page)) { 1335 up_write(&mftbmp_ni->runlist.lock); 1336 ntfs_error(vol->sb, "Failed to read from lcn bitmap."); 1337 return PTR_ERR(page); 1338 } 1339 b = (u8*)page_address(page) + (ll & ~PAGE_CACHE_MASK); 1340 tb = 1 << (lcn & 7ull); 1341 down_write(&vol->lcnbmp_lock); 1342 if (*b != 0xff && !(*b & tb)) { 1343 /* Next cluster is free, allocate it. */ 1344 *b |= tb; 1345 flush_dcache_page(page); 1346 set_page_dirty(page); 1347 up_write(&vol->lcnbmp_lock); 1348 ntfs_unmap_page(page); 1349 /* Update the mft bitmap runlist. */ 1350 rl->length++; 1351 rl[1].vcn++; 1352 status.added_cluster = 1; 1353 ntfs_debug("Appending one cluster to mft bitmap."); 1354 } else { 1355 up_write(&vol->lcnbmp_lock); 1356 ntfs_unmap_page(page); 1357 /* Allocate a cluster from the DATA_ZONE. */ 1358 rl2 = ntfs_cluster_alloc(vol, rl[1].vcn, 1, lcn, DATA_ZONE, 1359 TRUE); 1360 if (IS_ERR(rl2)) { 1361 up_write(&mftbmp_ni->runlist.lock); 1362 ntfs_error(vol->sb, "Failed to allocate a cluster for " 1363 "the mft bitmap."); 1364 return PTR_ERR(rl2); 1365 } 1366 rl = ntfs_runlists_merge(mftbmp_ni->runlist.rl, rl2); 1367 if (IS_ERR(rl)) { 1368 up_write(&mftbmp_ni->runlist.lock); 1369 ntfs_error(vol->sb, "Failed to merge runlists for mft " 1370 "bitmap."); 1371 if (ntfs_cluster_free_from_rl(vol, rl2)) { 1372 ntfs_error(vol->sb, "Failed to dealocate " 1373 "allocated cluster.%s", es); 1374 NVolSetErrors(vol); 1375 } 1376 ntfs_free(rl2); 1377 return PTR_ERR(rl); 1378 } 1379 mftbmp_ni->runlist.rl = rl; 1380 status.added_run = 1; 1381 ntfs_debug("Adding one run to mft bitmap."); 1382 /* Find the last run in the new runlist. */ 1383 for (; rl[1].length; rl++) 1384 ; 1385 } 1386 /* 1387 * Update the attribute record as well. Note: @rl is the last 1388 * (non-terminator) runlist element of mft bitmap. 1389 */ 1390 mrec = map_mft_record(mft_ni); 1391 if (IS_ERR(mrec)) { 1392 ntfs_error(vol->sb, "Failed to map mft record."); 1393 ret = PTR_ERR(mrec); 1394 goto undo_alloc; 1395 } 1396 ctx = ntfs_attr_get_search_ctx(mft_ni, mrec); 1397 if (unlikely(!ctx)) { 1398 ntfs_error(vol->sb, "Failed to get search context."); 1399 ret = -ENOMEM; 1400 goto undo_alloc; 1401 } 1402 ret = ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, 1403 mftbmp_ni->name_len, CASE_SENSITIVE, rl[1].vcn, NULL, 1404 0, ctx); 1405 if (unlikely(ret)) { 1406 ntfs_error(vol->sb, "Failed to find last attribute extent of " 1407 "mft bitmap attribute."); 1408 if (ret == -ENOENT) 1409 ret = -EIO; 1410 goto undo_alloc; 1411 } 1412 a = ctx->attr; 1413 ll = sle64_to_cpu(a->data.non_resident.lowest_vcn); 1414 /* Search back for the previous last allocated cluster of mft bitmap. */ 1415 for (rl2 = rl; rl2 > mftbmp_ni->runlist.rl; rl2--) { 1416 if (ll >= rl2->vcn) 1417 break; 1418 } 1419 BUG_ON(ll < rl2->vcn); 1420 BUG_ON(ll >= rl2->vcn + rl2->length); 1421 /* Get the size for the new mapping pairs array for this extent. */ 1422 mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, ll, -1); 1423 if (unlikely(mp_size <= 0)) { 1424 ntfs_error(vol->sb, "Get size for mapping pairs failed for " 1425 "mft bitmap attribute extent."); 1426 ret = mp_size; 1427 if (!ret) 1428 ret = -EIO; 1429 goto undo_alloc; 1430 } 1431 /* Expand the attribute record if necessary. */ 1432 old_alen = le32_to_cpu(a->length); 1433 ret = ntfs_attr_record_resize(ctx->mrec, a, mp_size + 1434 le16_to_cpu(a->data.non_resident.mapping_pairs_offset)); 1435 if (unlikely(ret)) { 1436 if (ret != -ENOSPC) { 1437 ntfs_error(vol->sb, "Failed to resize attribute " 1438 "record for mft bitmap attribute."); 1439 goto undo_alloc; 1440 } 1441 // TODO: Deal with this by moving this extent to a new mft 1442 // record or by starting a new extent in a new mft record or by 1443 // moving other attributes out of this mft record. 1444 // Note: It will need to be a special mft record and if none of 1445 // those are available it gets rather complicated... 1446 ntfs_error(vol->sb, "Not enough space in this mft record to " 1447 "accomodate extended mft bitmap attribute " 1448 "extent. Cannot handle this yet."); 1449 ret = -EOPNOTSUPP; 1450 goto undo_alloc; 1451 } 1452 status.mp_rebuilt = 1; 1453 /* Generate the mapping pairs array directly into the attr record. */ 1454 ret = ntfs_mapping_pairs_build(vol, (u8*)a + 1455 le16_to_cpu(a->data.non_resident.mapping_pairs_offset), 1456 mp_size, rl2, ll, -1, NULL); 1457 if (unlikely(ret)) { 1458 ntfs_error(vol->sb, "Failed to build mapping pairs array for " 1459 "mft bitmap attribute."); 1460 goto undo_alloc; 1461 } 1462 /* Update the highest_vcn. */ 1463 a->data.non_resident.highest_vcn = cpu_to_sle64(rl[1].vcn - 1); 1464 /* 1465 * We now have extended the mft bitmap allocated_size by one cluster. 1466 * Reflect this in the ntfs_inode structure and the attribute record. 1467 */ 1468 if (a->data.non_resident.lowest_vcn) { 1469 /* 1470 * We are not in the first attribute extent, switch to it, but 1471 * first ensure the changes will make it to disk later. 1472 */ 1473 flush_dcache_mft_record_page(ctx->ntfs_ino); 1474 mark_mft_record_dirty(ctx->ntfs_ino); 1475 ntfs_attr_reinit_search_ctx(ctx); 1476 ret = ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, 1477 mftbmp_ni->name_len, CASE_SENSITIVE, 0, NULL, 1478 0, ctx); 1479 if (unlikely(ret)) { 1480 ntfs_error(vol->sb, "Failed to find first attribute " 1481 "extent of mft bitmap attribute."); 1482 goto restore_undo_alloc; 1483 } 1484 a = ctx->attr; 1485 } 1486 write_lock_irqsave(&mftbmp_ni->size_lock, flags); 1487 mftbmp_ni->allocated_size += vol->cluster_size; 1488 a->data.non_resident.allocated_size = 1489 cpu_to_sle64(mftbmp_ni->allocated_size); 1490 write_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 1491 /* Ensure the changes make it to disk. */ 1492 flush_dcache_mft_record_page(ctx->ntfs_ino); 1493 mark_mft_record_dirty(ctx->ntfs_ino); 1494 ntfs_attr_put_search_ctx(ctx); 1495 unmap_mft_record(mft_ni); 1496 up_write(&mftbmp_ni->runlist.lock); 1497 ntfs_debug("Done."); 1498 return 0; 1499 restore_undo_alloc: 1500 ntfs_attr_reinit_search_ctx(ctx); 1501 if (ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, 1502 mftbmp_ni->name_len, CASE_SENSITIVE, rl[1].vcn, NULL, 1503 0, ctx)) { 1504 ntfs_error(vol->sb, "Failed to find last attribute extent of " 1505 "mft bitmap attribute.%s", es); 1506 write_lock_irqsave(&mftbmp_ni->size_lock, flags); 1507 mftbmp_ni->allocated_size += vol->cluster_size; 1508 write_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 1509 ntfs_attr_put_search_ctx(ctx); 1510 unmap_mft_record(mft_ni); 1511 up_write(&mftbmp_ni->runlist.lock); 1512 /* 1513 * The only thing that is now wrong is ->allocated_size of the 1514 * base attribute extent which chkdsk should be able to fix. 1515 */ 1516 NVolSetErrors(vol); 1517 return ret; 1518 } 1519 a = ctx->attr; 1520 a->data.non_resident.highest_vcn = cpu_to_sle64(rl[1].vcn - 2); 1521 undo_alloc: 1522 if (status.added_cluster) { 1523 /* Truncate the last run in the runlist by one cluster. */ 1524 rl->length--; 1525 rl[1].vcn--; 1526 } else if (status.added_run) { 1527 lcn = rl->lcn; 1528 /* Remove the last run from the runlist. */ 1529 rl->lcn = rl[1].lcn; 1530 rl->length = 0; 1531 } 1532 /* Deallocate the cluster. */ 1533 down_write(&vol->lcnbmp_lock); 1534 if (ntfs_bitmap_clear_bit(vol->lcnbmp_ino, lcn)) { 1535 ntfs_error(vol->sb, "Failed to free allocated cluster.%s", es); 1536 NVolSetErrors(vol); 1537 } 1538 up_write(&vol->lcnbmp_lock); 1539 if (status.mp_rebuilt) { 1540 if (ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu( 1541 a->data.non_resident.mapping_pairs_offset), 1542 old_alen - le16_to_cpu( 1543 a->data.non_resident.mapping_pairs_offset), 1544 rl2, ll, -1, NULL)) { 1545 ntfs_error(vol->sb, "Failed to restore mapping pairs " 1546 "array.%s", es); 1547 NVolSetErrors(vol); 1548 } 1549 if (ntfs_attr_record_resize(ctx->mrec, a, old_alen)) { 1550 ntfs_error(vol->sb, "Failed to restore attribute " 1551 "record.%s", es); 1552 NVolSetErrors(vol); 1553 } 1554 flush_dcache_mft_record_page(ctx->ntfs_ino); 1555 mark_mft_record_dirty(ctx->ntfs_ino); 1556 } 1557 if (ctx) 1558 ntfs_attr_put_search_ctx(ctx); 1559 if (!IS_ERR(mrec)) 1560 unmap_mft_record(mft_ni); 1561 up_write(&mftbmp_ni->runlist.lock); 1562 return ret; 1563 } 1564 1565 /** 1566 * ntfs_mft_bitmap_extend_initialized_nolock - extend mftbmp initialized data 1567 * @vol: volume on which to extend the mft bitmap attribute 1568 * 1569 * Extend the initialized portion of the mft bitmap attribute on the ntfs 1570 * volume @vol by 8 bytes. 1571 * 1572 * Note: Only changes initialized_size and data_size, i.e. requires that 1573 * allocated_size is big enough to fit the new initialized_size. 1574 * 1575 * Return 0 on success and -error on error. 1576 * 1577 * Locking: Caller must hold vol->mftbmp_lock for writing. 1578 */ 1579 static int ntfs_mft_bitmap_extend_initialized_nolock(ntfs_volume *vol) 1580 { 1581 s64 old_data_size, old_initialized_size; 1582 unsigned long flags; 1583 struct inode *mftbmp_vi; 1584 ntfs_inode *mft_ni, *mftbmp_ni; 1585 ntfs_attr_search_ctx *ctx; 1586 MFT_RECORD *mrec; 1587 ATTR_RECORD *a; 1588 int ret; 1589 1590 ntfs_debug("Extending mft bitmap initiailized (and data) size."); 1591 mft_ni = NTFS_I(vol->mft_ino); 1592 mftbmp_vi = vol->mftbmp_ino; 1593 mftbmp_ni = NTFS_I(mftbmp_vi); 1594 /* Get the attribute record. */ 1595 mrec = map_mft_record(mft_ni); 1596 if (IS_ERR(mrec)) { 1597 ntfs_error(vol->sb, "Failed to map mft record."); 1598 return PTR_ERR(mrec); 1599 } 1600 ctx = ntfs_attr_get_search_ctx(mft_ni, mrec); 1601 if (unlikely(!ctx)) { 1602 ntfs_error(vol->sb, "Failed to get search context."); 1603 ret = -ENOMEM; 1604 goto unm_err_out; 1605 } 1606 ret = ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, 1607 mftbmp_ni->name_len, CASE_SENSITIVE, 0, NULL, 0, ctx); 1608 if (unlikely(ret)) { 1609 ntfs_error(vol->sb, "Failed to find first attribute extent of " 1610 "mft bitmap attribute."); 1611 if (ret == -ENOENT) 1612 ret = -EIO; 1613 goto put_err_out; 1614 } 1615 a = ctx->attr; 1616 write_lock_irqsave(&mftbmp_ni->size_lock, flags); 1617 old_data_size = i_size_read(mftbmp_vi); 1618 old_initialized_size = mftbmp_ni->initialized_size; 1619 /* 1620 * We can simply update the initialized_size before filling the space 1621 * with zeroes because the caller is holding the mft bitmap lock for 1622 * writing which ensures that no one else is trying to access the data. 1623 */ 1624 mftbmp_ni->initialized_size += 8; 1625 a->data.non_resident.initialized_size = 1626 cpu_to_sle64(mftbmp_ni->initialized_size); 1627 if (mftbmp_ni->initialized_size > old_data_size) { 1628 i_size_write(mftbmp_vi, mftbmp_ni->initialized_size); 1629 a->data.non_resident.data_size = 1630 cpu_to_sle64(mftbmp_ni->initialized_size); 1631 } 1632 write_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 1633 /* Ensure the changes make it to disk. */ 1634 flush_dcache_mft_record_page(ctx->ntfs_ino); 1635 mark_mft_record_dirty(ctx->ntfs_ino); 1636 ntfs_attr_put_search_ctx(ctx); 1637 unmap_mft_record(mft_ni); 1638 /* Initialize the mft bitmap attribute value with zeroes. */ 1639 ret = ntfs_attr_set(mftbmp_ni, old_initialized_size, 8, 0); 1640 if (likely(!ret)) { 1641 ntfs_debug("Done. (Wrote eight initialized bytes to mft " 1642 "bitmap."); 1643 return 0; 1644 } 1645 ntfs_error(vol->sb, "Failed to write to mft bitmap."); 1646 /* Try to recover from the error. */ 1647 mrec = map_mft_record(mft_ni); 1648 if (IS_ERR(mrec)) { 1649 ntfs_error(vol->sb, "Failed to map mft record.%s", es); 1650 NVolSetErrors(vol); 1651 return ret; 1652 } 1653 ctx = ntfs_attr_get_search_ctx(mft_ni, mrec); 1654 if (unlikely(!ctx)) { 1655 ntfs_error(vol->sb, "Failed to get search context.%s", es); 1656 NVolSetErrors(vol); 1657 goto unm_err_out; 1658 } 1659 if (ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, 1660 mftbmp_ni->name_len, CASE_SENSITIVE, 0, NULL, 0, ctx)) { 1661 ntfs_error(vol->sb, "Failed to find first attribute extent of " 1662 "mft bitmap attribute.%s", es); 1663 NVolSetErrors(vol); 1664 put_err_out: 1665 ntfs_attr_put_search_ctx(ctx); 1666 unm_err_out: 1667 unmap_mft_record(mft_ni); 1668 goto err_out; 1669 } 1670 a = ctx->attr; 1671 write_lock_irqsave(&mftbmp_ni->size_lock, flags); 1672 mftbmp_ni->initialized_size = old_initialized_size; 1673 a->data.non_resident.initialized_size = 1674 cpu_to_sle64(old_initialized_size); 1675 if (i_size_read(mftbmp_vi) != old_data_size) { 1676 i_size_write(mftbmp_vi, old_data_size); 1677 a->data.non_resident.data_size = cpu_to_sle64(old_data_size); 1678 } 1679 write_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 1680 flush_dcache_mft_record_page(ctx->ntfs_ino); 1681 mark_mft_record_dirty(ctx->ntfs_ino); 1682 ntfs_attr_put_search_ctx(ctx); 1683 unmap_mft_record(mft_ni); 1684 #ifdef DEBUG 1685 read_lock_irqsave(&mftbmp_ni->size_lock, flags); 1686 ntfs_debug("Restored status of mftbmp: allocated_size 0x%llx, " 1687 "data_size 0x%llx, initialized_size 0x%llx.", 1688 (long long)mftbmp_ni->allocated_size, 1689 (long long)i_size_read(mftbmp_vi), 1690 (long long)mftbmp_ni->initialized_size); 1691 read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 1692 #endif /* DEBUG */ 1693 err_out: 1694 return ret; 1695 } 1696 1697 /** 1698 * ntfs_mft_data_extend_allocation_nolock - extend mft data attribute 1699 * @vol: volume on which to extend the mft data attribute 1700 * 1701 * Extend the mft data attribute on the ntfs volume @vol by 16 mft records 1702 * worth of clusters or if not enough space for this by one mft record worth 1703 * of clusters. 1704 * 1705 * Note: Only changes allocated_size, i.e. does not touch initialized_size or 1706 * data_size. 1707 * 1708 * Return 0 on success and -errno on error. 1709 * 1710 * Locking: - Caller must hold vol->mftbmp_lock for writing. 1711 * - This function takes NTFS_I(vol->mft_ino)->runlist.lock for 1712 * writing and releases it before returning. 1713 * - This function calls functions which take vol->lcnbmp_lock for 1714 * writing and release it before returning. 1715 */ 1716 static int ntfs_mft_data_extend_allocation_nolock(ntfs_volume *vol) 1717 { 1718 LCN lcn; 1719 VCN old_last_vcn; 1720 s64 min_nr, nr, ll; 1721 unsigned long flags; 1722 ntfs_inode *mft_ni; 1723 runlist_element *rl, *rl2; 1724 ntfs_attr_search_ctx *ctx = NULL; 1725 MFT_RECORD *mrec; 1726 ATTR_RECORD *a = NULL; 1727 int ret, mp_size; 1728 u32 old_alen = 0; 1729 BOOL mp_rebuilt = FALSE; 1730 1731 ntfs_debug("Extending mft data allocation."); 1732 mft_ni = NTFS_I(vol->mft_ino); 1733 /* 1734 * Determine the preferred allocation location, i.e. the last lcn of 1735 * the mft data attribute. The allocated size of the mft data 1736 * attribute cannot be zero so we are ok to do this. 1737 */ 1738 down_write(&mft_ni->runlist.lock); 1739 read_lock_irqsave(&mft_ni->size_lock, flags); 1740 ll = mft_ni->allocated_size; 1741 read_unlock_irqrestore(&mft_ni->size_lock, flags); 1742 rl = ntfs_attr_find_vcn_nolock(mft_ni, 1743 (ll - 1) >> vol->cluster_size_bits, NULL); 1744 if (unlikely(IS_ERR(rl) || !rl->length || rl->lcn < 0)) { 1745 up_write(&mft_ni->runlist.lock); 1746 ntfs_error(vol->sb, "Failed to determine last allocated " 1747 "cluster of mft data attribute."); 1748 if (!IS_ERR(rl)) 1749 ret = -EIO; 1750 else 1751 ret = PTR_ERR(rl); 1752 return ret; 1753 } 1754 lcn = rl->lcn + rl->length; 1755 ntfs_debug("Last lcn of mft data attribute is 0x%llx.", (long long)lcn); 1756 /* Minimum allocation is one mft record worth of clusters. */ 1757 min_nr = vol->mft_record_size >> vol->cluster_size_bits; 1758 if (!min_nr) 1759 min_nr = 1; 1760 /* Want to allocate 16 mft records worth of clusters. */ 1761 nr = vol->mft_record_size << 4 >> vol->cluster_size_bits; 1762 if (!nr) 1763 nr = min_nr; 1764 /* Ensure we do not go above 2^32-1 mft records. */ 1765 read_lock_irqsave(&mft_ni->size_lock, flags); 1766 ll = mft_ni->allocated_size; 1767 read_unlock_irqrestore(&mft_ni->size_lock, flags); 1768 if (unlikely((ll + (nr << vol->cluster_size_bits)) >> 1769 vol->mft_record_size_bits >= (1ll << 32))) { 1770 nr = min_nr; 1771 if (unlikely((ll + (nr << vol->cluster_size_bits)) >> 1772 vol->mft_record_size_bits >= (1ll << 32))) { 1773 ntfs_warning(vol->sb, "Cannot allocate mft record " 1774 "because the maximum number of inodes " 1775 "(2^32) has already been reached."); 1776 up_write(&mft_ni->runlist.lock); 1777 return -ENOSPC; 1778 } 1779 } 1780 ntfs_debug("Trying mft data allocation with %s cluster count %lli.", 1781 nr > min_nr ? "default" : "minimal", (long long)nr); 1782 old_last_vcn = rl[1].vcn; 1783 do { 1784 rl2 = ntfs_cluster_alloc(vol, old_last_vcn, nr, lcn, MFT_ZONE, 1785 TRUE); 1786 if (likely(!IS_ERR(rl2))) 1787 break; 1788 if (PTR_ERR(rl2) != -ENOSPC || nr == min_nr) { 1789 ntfs_error(vol->sb, "Failed to allocate the minimal " 1790 "number of clusters (%lli) for the " 1791 "mft data attribute.", (long long)nr); 1792 up_write(&mft_ni->runlist.lock); 1793 return PTR_ERR(rl2); 1794 } 1795 /* 1796 * There is not enough space to do the allocation, but there 1797 * might be enough space to do a minimal allocation so try that 1798 * before failing. 1799 */ 1800 nr = min_nr; 1801 ntfs_debug("Retrying mft data allocation with minimal cluster " 1802 "count %lli.", (long long)nr); 1803 } while (1); 1804 rl = ntfs_runlists_merge(mft_ni->runlist.rl, rl2); 1805 if (IS_ERR(rl)) { 1806 up_write(&mft_ni->runlist.lock); 1807 ntfs_error(vol->sb, "Failed to merge runlists for mft data " 1808 "attribute."); 1809 if (ntfs_cluster_free_from_rl(vol, rl2)) { 1810 ntfs_error(vol->sb, "Failed to dealocate clusters " 1811 "from the mft data attribute.%s", es); 1812 NVolSetErrors(vol); 1813 } 1814 ntfs_free(rl2); 1815 return PTR_ERR(rl); 1816 } 1817 mft_ni->runlist.rl = rl; 1818 ntfs_debug("Allocated %lli clusters.", (long long)nr); 1819 /* Find the last run in the new runlist. */ 1820 for (; rl[1].length; rl++) 1821 ; 1822 /* Update the attribute record as well. */ 1823 mrec = map_mft_record(mft_ni); 1824 if (IS_ERR(mrec)) { 1825 ntfs_error(vol->sb, "Failed to map mft record."); 1826 ret = PTR_ERR(mrec); 1827 goto undo_alloc; 1828 } 1829 ctx = ntfs_attr_get_search_ctx(mft_ni, mrec); 1830 if (unlikely(!ctx)) { 1831 ntfs_error(vol->sb, "Failed to get search context."); 1832 ret = -ENOMEM; 1833 goto undo_alloc; 1834 } 1835 ret = ntfs_attr_lookup(mft_ni->type, mft_ni->name, mft_ni->name_len, 1836 CASE_SENSITIVE, rl[1].vcn, NULL, 0, ctx); 1837 if (unlikely(ret)) { 1838 ntfs_error(vol->sb, "Failed to find last attribute extent of " 1839 "mft data attribute."); 1840 if (ret == -ENOENT) 1841 ret = -EIO; 1842 goto undo_alloc; 1843 } 1844 a = ctx->attr; 1845 ll = sle64_to_cpu(a->data.non_resident.lowest_vcn); 1846 /* Search back for the previous last allocated cluster of mft bitmap. */ 1847 for (rl2 = rl; rl2 > mft_ni->runlist.rl; rl2--) { 1848 if (ll >= rl2->vcn) 1849 break; 1850 } 1851 BUG_ON(ll < rl2->vcn); 1852 BUG_ON(ll >= rl2->vcn + rl2->length); 1853 /* Get the size for the new mapping pairs array for this extent. */ 1854 mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, ll, -1); 1855 if (unlikely(mp_size <= 0)) { 1856 ntfs_error(vol->sb, "Get size for mapping pairs failed for " 1857 "mft data attribute extent."); 1858 ret = mp_size; 1859 if (!ret) 1860 ret = -EIO; 1861 goto undo_alloc; 1862 } 1863 /* Expand the attribute record if necessary. */ 1864 old_alen = le32_to_cpu(a->length); 1865 ret = ntfs_attr_record_resize(ctx->mrec, a, mp_size + 1866 le16_to_cpu(a->data.non_resident.mapping_pairs_offset)); 1867 if (unlikely(ret)) { 1868 if (ret != -ENOSPC) { 1869 ntfs_error(vol->sb, "Failed to resize attribute " 1870 "record for mft data attribute."); 1871 goto undo_alloc; 1872 } 1873 // TODO: Deal with this by moving this extent to a new mft 1874 // record or by starting a new extent in a new mft record or by 1875 // moving other attributes out of this mft record. 1876 // Note: Use the special reserved mft records and ensure that 1877 // this extent is not required to find the mft record in 1878 // question. If no free special records left we would need to 1879 // move an existing record away, insert ours in its place, and 1880 // then place the moved record into the newly allocated space 1881 // and we would then need to update all references to this mft 1882 // record appropriately. This is rather complicated... 1883 ntfs_error(vol->sb, "Not enough space in this mft record to " 1884 "accomodate extended mft data attribute " 1885 "extent. Cannot handle this yet."); 1886 ret = -EOPNOTSUPP; 1887 goto undo_alloc; 1888 } 1889 mp_rebuilt = TRUE; 1890 /* Generate the mapping pairs array directly into the attr record. */ 1891 ret = ntfs_mapping_pairs_build(vol, (u8*)a + 1892 le16_to_cpu(a->data.non_resident.mapping_pairs_offset), 1893 mp_size, rl2, ll, -1, NULL); 1894 if (unlikely(ret)) { 1895 ntfs_error(vol->sb, "Failed to build mapping pairs array of " 1896 "mft data attribute."); 1897 goto undo_alloc; 1898 } 1899 /* Update the highest_vcn. */ 1900 a->data.non_resident.highest_vcn = cpu_to_sle64(rl[1].vcn - 1); 1901 /* 1902 * We now have extended the mft data allocated_size by nr clusters. 1903 * Reflect this in the ntfs_inode structure and the attribute record. 1904 * @rl is the last (non-terminator) runlist element of mft data 1905 * attribute. 1906 */ 1907 if (a->data.non_resident.lowest_vcn) { 1908 /* 1909 * We are not in the first attribute extent, switch to it, but 1910 * first ensure the changes will make it to disk later. 1911 */ 1912 flush_dcache_mft_record_page(ctx->ntfs_ino); 1913 mark_mft_record_dirty(ctx->ntfs_ino); 1914 ntfs_attr_reinit_search_ctx(ctx); 1915 ret = ntfs_attr_lookup(mft_ni->type, mft_ni->name, 1916 mft_ni->name_len, CASE_SENSITIVE, 0, NULL, 0, 1917 ctx); 1918 if (unlikely(ret)) { 1919 ntfs_error(vol->sb, "Failed to find first attribute " 1920 "extent of mft data attribute."); 1921 goto restore_undo_alloc; 1922 } 1923 a = ctx->attr; 1924 } 1925 write_lock_irqsave(&mft_ni->size_lock, flags); 1926 mft_ni->allocated_size += nr << vol->cluster_size_bits; 1927 a->data.non_resident.allocated_size = 1928 cpu_to_sle64(mft_ni->allocated_size); 1929 write_unlock_irqrestore(&mft_ni->size_lock, flags); 1930 /* Ensure the changes make it to disk. */ 1931 flush_dcache_mft_record_page(ctx->ntfs_ino); 1932 mark_mft_record_dirty(ctx->ntfs_ino); 1933 ntfs_attr_put_search_ctx(ctx); 1934 unmap_mft_record(mft_ni); 1935 up_write(&mft_ni->runlist.lock); 1936 ntfs_debug("Done."); 1937 return 0; 1938 restore_undo_alloc: 1939 ntfs_attr_reinit_search_ctx(ctx); 1940 if (ntfs_attr_lookup(mft_ni->type, mft_ni->name, mft_ni->name_len, 1941 CASE_SENSITIVE, rl[1].vcn, NULL, 0, ctx)) { 1942 ntfs_error(vol->sb, "Failed to find last attribute extent of " 1943 "mft data attribute.%s", es); 1944 write_lock_irqsave(&mft_ni->size_lock, flags); 1945 mft_ni->allocated_size += nr << vol->cluster_size_bits; 1946 write_unlock_irqrestore(&mft_ni->size_lock, flags); 1947 ntfs_attr_put_search_ctx(ctx); 1948 unmap_mft_record(mft_ni); 1949 up_write(&mft_ni->runlist.lock); 1950 /* 1951 * The only thing that is now wrong is ->allocated_size of the 1952 * base attribute extent which chkdsk should be able to fix. 1953 */ 1954 NVolSetErrors(vol); 1955 return ret; 1956 } 1957 ctx->attr->data.non_resident.highest_vcn = 1958 cpu_to_sle64(old_last_vcn - 1); 1959 undo_alloc: 1960 if (ntfs_cluster_free(mft_ni, old_last_vcn, -1, ctx) < 0) { 1961 ntfs_error(vol->sb, "Failed to free clusters from mft data " 1962 "attribute.%s", es); 1963 NVolSetErrors(vol); 1964 } 1965 a = ctx->attr; 1966 if (ntfs_rl_truncate_nolock(vol, &mft_ni->runlist, old_last_vcn)) { 1967 ntfs_error(vol->sb, "Failed to truncate mft data attribute " 1968 "runlist.%s", es); 1969 NVolSetErrors(vol); 1970 } 1971 if (mp_rebuilt && !IS_ERR(ctx->mrec)) { 1972 if (ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu( 1973 a->data.non_resident.mapping_pairs_offset), 1974 old_alen - le16_to_cpu( 1975 a->data.non_resident.mapping_pairs_offset), 1976 rl2, ll, -1, NULL)) { 1977 ntfs_error(vol->sb, "Failed to restore mapping pairs " 1978 "array.%s", es); 1979 NVolSetErrors(vol); 1980 } 1981 if (ntfs_attr_record_resize(ctx->mrec, a, old_alen)) { 1982 ntfs_error(vol->sb, "Failed to restore attribute " 1983 "record.%s", es); 1984 NVolSetErrors(vol); 1985 } 1986 flush_dcache_mft_record_page(ctx->ntfs_ino); 1987 mark_mft_record_dirty(ctx->ntfs_ino); 1988 } else if (IS_ERR(ctx->mrec)) { 1989 ntfs_error(vol->sb, "Failed to restore attribute search " 1990 "context.%s", es); 1991 NVolSetErrors(vol); 1992 } 1993 if (ctx) 1994 ntfs_attr_put_search_ctx(ctx); 1995 if (!IS_ERR(mrec)) 1996 unmap_mft_record(mft_ni); 1997 up_write(&mft_ni->runlist.lock); 1998 return ret; 1999 } 2000 2001 /** 2002 * ntfs_mft_record_layout - layout an mft record into a memory buffer 2003 * @vol: volume to which the mft record will belong 2004 * @mft_no: mft reference specifying the mft record number 2005 * @m: destination buffer of size >= @vol->mft_record_size bytes 2006 * 2007 * Layout an empty, unused mft record with the mft record number @mft_no into 2008 * the buffer @m. The volume @vol is needed because the mft record structure 2009 * was modified in NTFS 3.1 so we need to know which volume version this mft 2010 * record will be used on. 2011 * 2012 * Return 0 on success and -errno on error. 2013 */ 2014 static int ntfs_mft_record_layout(const ntfs_volume *vol, const s64 mft_no, 2015 MFT_RECORD *m) 2016 { 2017 ATTR_RECORD *a; 2018 2019 ntfs_debug("Entering for mft record 0x%llx.", (long long)mft_no); 2020 if (mft_no >= (1ll << 32)) { 2021 ntfs_error(vol->sb, "Mft record number 0x%llx exceeds " 2022 "maximum of 2^32.", (long long)mft_no); 2023 return -ERANGE; 2024 } 2025 /* Start by clearing the whole mft record to gives us a clean slate. */ 2026 memset(m, 0, vol->mft_record_size); 2027 /* Aligned to 2-byte boundary. */ 2028 if (vol->major_ver < 3 || (vol->major_ver == 3 && !vol->minor_ver)) 2029 m->usa_ofs = cpu_to_le16((sizeof(MFT_RECORD_OLD) + 1) & ~1); 2030 else { 2031 m->usa_ofs = cpu_to_le16((sizeof(MFT_RECORD) + 1) & ~1); 2032 /* 2033 * Set the NTFS 3.1+ specific fields while we know that the 2034 * volume version is 3.1+. 2035 */ 2036 m->reserved = 0; 2037 m->mft_record_number = cpu_to_le32((u32)mft_no); 2038 } 2039 m->magic = magic_FILE; 2040 if (vol->mft_record_size >= NTFS_BLOCK_SIZE) 2041 m->usa_count = cpu_to_le16(vol->mft_record_size / 2042 NTFS_BLOCK_SIZE + 1); 2043 else { 2044 m->usa_count = cpu_to_le16(1); 2045 ntfs_warning(vol->sb, "Sector size is bigger than mft record " 2046 "size. Setting usa_count to 1. If chkdsk " 2047 "reports this as corruption, please email " 2048 "linux-ntfs-dev@lists.sourceforge.net stating " 2049 "that you saw this message and that the " 2050 "modified filesystem created was corrupt. " 2051 "Thank you."); 2052 } 2053 /* Set the update sequence number to 1. */ 2054 *(le16*)((u8*)m + le16_to_cpu(m->usa_ofs)) = cpu_to_le16(1); 2055 m->lsn = 0; 2056 m->sequence_number = cpu_to_le16(1); 2057 m->link_count = 0; 2058 /* 2059 * Place the attributes straight after the update sequence array, 2060 * aligned to 8-byte boundary. 2061 */ 2062 m->attrs_offset = cpu_to_le16((le16_to_cpu(m->usa_ofs) + 2063 (le16_to_cpu(m->usa_count) << 1) + 7) & ~7); 2064 m->flags = 0; 2065 /* 2066 * Using attrs_offset plus eight bytes (for the termination attribute). 2067 * attrs_offset is already aligned to 8-byte boundary, so no need to 2068 * align again. 2069 */ 2070 m->bytes_in_use = cpu_to_le32(le16_to_cpu(m->attrs_offset) + 8); 2071 m->bytes_allocated = cpu_to_le32(vol->mft_record_size); 2072 m->base_mft_record = 0; 2073 m->next_attr_instance = 0; 2074 /* Add the termination attribute. */ 2075 a = (ATTR_RECORD*)((u8*)m + le16_to_cpu(m->attrs_offset)); 2076 a->type = AT_END; 2077 a->length = 0; 2078 ntfs_debug("Done."); 2079 return 0; 2080 } 2081 2082 /** 2083 * ntfs_mft_record_format - format an mft record on an ntfs volume 2084 * @vol: volume on which to format the mft record 2085 * @mft_no: mft record number to format 2086 * 2087 * Format the mft record @mft_no in $MFT/$DATA, i.e. lay out an empty, unused 2088 * mft record into the appropriate place of the mft data attribute. This is 2089 * used when extending the mft data attribute. 2090 * 2091 * Return 0 on success and -errno on error. 2092 */ 2093 static int ntfs_mft_record_format(const ntfs_volume *vol, const s64 mft_no) 2094 { 2095 loff_t i_size; 2096 struct inode *mft_vi = vol->mft_ino; 2097 struct page *page; 2098 MFT_RECORD *m; 2099 pgoff_t index, end_index; 2100 unsigned int ofs; 2101 int err; 2102 2103 ntfs_debug("Entering for mft record 0x%llx.", (long long)mft_no); 2104 /* 2105 * The index into the page cache and the offset within the page cache 2106 * page of the wanted mft record. 2107 */ 2108 index = mft_no << vol->mft_record_size_bits >> PAGE_CACHE_SHIFT; 2109 ofs = (mft_no << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK; 2110 /* The maximum valid index into the page cache for $MFT's data. */ 2111 i_size = i_size_read(mft_vi); 2112 end_index = i_size >> PAGE_CACHE_SHIFT; 2113 if (unlikely(index >= end_index)) { 2114 if (unlikely(index > end_index || ofs + vol->mft_record_size >= 2115 (i_size & ~PAGE_CACHE_MASK))) { 2116 ntfs_error(vol->sb, "Tried to format non-existing mft " 2117 "record 0x%llx.", (long long)mft_no); 2118 return -ENOENT; 2119 } 2120 } 2121 /* Read, map, and pin the page containing the mft record. */ 2122 page = ntfs_map_page(mft_vi->i_mapping, index); 2123 if (unlikely(IS_ERR(page))) { 2124 ntfs_error(vol->sb, "Failed to map page containing mft record " 2125 "to format 0x%llx.", (long long)mft_no); 2126 return PTR_ERR(page); 2127 } 2128 lock_page(page); 2129 BUG_ON(!PageUptodate(page)); 2130 ClearPageUptodate(page); 2131 m = (MFT_RECORD*)((u8*)page_address(page) + ofs); 2132 err = ntfs_mft_record_layout(vol, mft_no, m); 2133 if (unlikely(err)) { 2134 ntfs_error(vol->sb, "Failed to layout mft record 0x%llx.", 2135 (long long)mft_no); 2136 SetPageUptodate(page); 2137 unlock_page(page); 2138 ntfs_unmap_page(page); 2139 return err; 2140 } 2141 flush_dcache_page(page); 2142 SetPageUptodate(page); 2143 unlock_page(page); 2144 /* 2145 * Make sure the mft record is written out to disk. We could use 2146 * ilookup5() to check if an inode is in icache and so on but this is 2147 * unnecessary as ntfs_writepage() will write the dirty record anyway. 2148 */ 2149 mark_ntfs_record_dirty(page, ofs); 2150 ntfs_unmap_page(page); 2151 ntfs_debug("Done."); 2152 return 0; 2153 } 2154 2155 /** 2156 * ntfs_mft_record_alloc - allocate an mft record on an ntfs volume 2157 * @vol: [IN] volume on which to allocate the mft record 2158 * @mode: [IN] mode if want a file or directory, i.e. base inode or 0 2159 * @base_ni: [IN] open base inode if allocating an extent mft record or NULL 2160 * @mrec: [OUT] on successful return this is the mapped mft record 2161 * 2162 * Allocate an mft record in $MFT/$DATA of an open ntfs volume @vol. 2163 * 2164 * If @base_ni is NULL make the mft record a base mft record, i.e. a file or 2165 * direvctory inode, and allocate it at the default allocator position. In 2166 * this case @mode is the file mode as given to us by the caller. We in 2167 * particular use @mode to distinguish whether a file or a directory is being 2168 * created (S_IFDIR(mode) and S_IFREG(mode), respectively). 2169 * 2170 * If @base_ni is not NULL make the allocated mft record an extent record, 2171 * allocate it starting at the mft record after the base mft record and attach 2172 * the allocated and opened ntfs inode to the base inode @base_ni. In this 2173 * case @mode must be 0 as it is meaningless for extent inodes. 2174 * 2175 * You need to check the return value with IS_ERR(). If false, the function 2176 * was successful and the return value is the now opened ntfs inode of the 2177 * allocated mft record. *@mrec is then set to the allocated, mapped, pinned, 2178 * and locked mft record. If IS_ERR() is true, the function failed and the 2179 * error code is obtained from PTR_ERR(return value). *@mrec is undefined in 2180 * this case. 2181 * 2182 * Allocation strategy: 2183 * 2184 * To find a free mft record, we scan the mft bitmap for a zero bit. To 2185 * optimize this we start scanning at the place specified by @base_ni or if 2186 * @base_ni is NULL we start where we last stopped and we perform wrap around 2187 * when we reach the end. Note, we do not try to allocate mft records below 2188 * number 24 because numbers 0 to 15 are the defined system files anyway and 16 2189 * to 24 are special in that they are used for storing extension mft records 2190 * for the $DATA attribute of $MFT. This is required to avoid the possibility 2191 * of creating a runlist with a circular dependency which once written to disk 2192 * can never be read in again. Windows will only use records 16 to 24 for 2193 * normal files if the volume is completely out of space. We never use them 2194 * which means that when the volume is really out of space we cannot create any 2195 * more files while Windows can still create up to 8 small files. We can start 2196 * doing this at some later time, it does not matter much for now. 2197 * 2198 * When scanning the mft bitmap, we only search up to the last allocated mft 2199 * record. If there are no free records left in the range 24 to number of 2200 * allocated mft records, then we extend the $MFT/$DATA attribute in order to 2201 * create free mft records. We extend the allocated size of $MFT/$DATA by 16 2202 * records at a time or one cluster, if cluster size is above 16kiB. If there 2203 * is not sufficient space to do this, we try to extend by a single mft record 2204 * or one cluster, if cluster size is above the mft record size. 2205 * 2206 * No matter how many mft records we allocate, we initialize only the first 2207 * allocated mft record, incrementing mft data size and initialized size 2208 * accordingly, open an ntfs_inode for it and return it to the caller, unless 2209 * there are less than 24 mft records, in which case we allocate and initialize 2210 * mft records until we reach record 24 which we consider as the first free mft 2211 * record for use by normal files. 2212 * 2213 * If during any stage we overflow the initialized data in the mft bitmap, we 2214 * extend the initialized size (and data size) by 8 bytes, allocating another 2215 * cluster if required. The bitmap data size has to be at least equal to the 2216 * number of mft records in the mft, but it can be bigger, in which case the 2217 * superflous bits are padded with zeroes. 2218 * 2219 * Thus, when we return successfully (IS_ERR() is false), we will have: 2220 * - initialized / extended the mft bitmap if necessary, 2221 * - initialized / extended the mft data if necessary, 2222 * - set the bit corresponding to the mft record being allocated in the 2223 * mft bitmap, 2224 * - opened an ntfs_inode for the allocated mft record, and we will have 2225 * - returned the ntfs_inode as well as the allocated mapped, pinned, and 2226 * locked mft record. 2227 * 2228 * On error, the volume will be left in a consistent state and no record will 2229 * be allocated. If rolling back a partial operation fails, we may leave some 2230 * inconsistent metadata in which case we set NVolErrors() so the volume is 2231 * left dirty when unmounted. 2232 * 2233 * Note, this function cannot make use of most of the normal functions, like 2234 * for example for attribute resizing, etc, because when the run list overflows 2235 * the base mft record and an attribute list is used, it is very important that 2236 * the extension mft records used to store the $DATA attribute of $MFT can be 2237 * reached without having to read the information contained inside them, as 2238 * this would make it impossible to find them in the first place after the 2239 * volume is unmounted. $MFT/$BITMAP probably does not need to follow this 2240 * rule because the bitmap is not essential for finding the mft records, but on 2241 * the other hand, handling the bitmap in this special way would make life 2242 * easier because otherwise there might be circular invocations of functions 2243 * when reading the bitmap. 2244 */ 2245 ntfs_inode *ntfs_mft_record_alloc(ntfs_volume *vol, const int mode, 2246 ntfs_inode *base_ni, MFT_RECORD **mrec) 2247 { 2248 s64 ll, bit, old_data_initialized, old_data_size; 2249 unsigned long flags; 2250 struct inode *vi; 2251 struct page *page; 2252 ntfs_inode *mft_ni, *mftbmp_ni, *ni; 2253 ntfs_attr_search_ctx *ctx; 2254 MFT_RECORD *m; 2255 ATTR_RECORD *a; 2256 pgoff_t index; 2257 unsigned int ofs; 2258 int err; 2259 le16 seq_no, usn; 2260 BOOL record_formatted = FALSE; 2261 2262 if (base_ni) { 2263 ntfs_debug("Entering (allocating an extent mft record for " 2264 "base mft record 0x%llx).", 2265 (long long)base_ni->mft_no); 2266 /* @mode and @base_ni are mutually exclusive. */ 2267 BUG_ON(mode); 2268 } else 2269 ntfs_debug("Entering (allocating a base mft record)."); 2270 if (mode) { 2271 /* @mode and @base_ni are mutually exclusive. */ 2272 BUG_ON(base_ni); 2273 /* We only support creation of normal files and directories. */ 2274 if (!S_ISREG(mode) && !S_ISDIR(mode)) 2275 return ERR_PTR(-EOPNOTSUPP); 2276 } 2277 BUG_ON(!mrec); 2278 mft_ni = NTFS_I(vol->mft_ino); 2279 mftbmp_ni = NTFS_I(vol->mftbmp_ino); 2280 down_write(&vol->mftbmp_lock); 2281 bit = ntfs_mft_bitmap_find_and_alloc_free_rec_nolock(vol, base_ni); 2282 if (bit >= 0) { 2283 ntfs_debug("Found and allocated free record (#1), bit 0x%llx.", 2284 (long long)bit); 2285 goto have_alloc_rec; 2286 } 2287 if (bit != -ENOSPC) { 2288 up_write(&vol->mftbmp_lock); 2289 return ERR_PTR(bit); 2290 } 2291 /* 2292 * No free mft records left. If the mft bitmap already covers more 2293 * than the currently used mft records, the next records are all free, 2294 * so we can simply allocate the first unused mft record. 2295 * Note: We also have to make sure that the mft bitmap at least covers 2296 * the first 24 mft records as they are special and whilst they may not 2297 * be in use, we do not allocate from them. 2298 */ 2299 read_lock_irqsave(&mft_ni->size_lock, flags); 2300 ll = mft_ni->initialized_size >> vol->mft_record_size_bits; 2301 read_unlock_irqrestore(&mft_ni->size_lock, flags); 2302 read_lock_irqsave(&mftbmp_ni->size_lock, flags); 2303 old_data_initialized = mftbmp_ni->initialized_size; 2304 read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 2305 if (old_data_initialized << 3 > ll && old_data_initialized > 3) { 2306 bit = ll; 2307 if (bit < 24) 2308 bit = 24; 2309 if (unlikely(bit >= (1ll << 32))) 2310 goto max_err_out; 2311 ntfs_debug("Found free record (#2), bit 0x%llx.", 2312 (long long)bit); 2313 goto found_free_rec; 2314 } 2315 /* 2316 * The mft bitmap needs to be expanded until it covers the first unused 2317 * mft record that we can allocate. 2318 * Note: The smallest mft record we allocate is mft record 24. 2319 */ 2320 bit = old_data_initialized << 3; 2321 if (unlikely(bit >= (1ll << 32))) 2322 goto max_err_out; 2323 read_lock_irqsave(&mftbmp_ni->size_lock, flags); 2324 old_data_size = mftbmp_ni->allocated_size; 2325 ntfs_debug("Status of mftbmp before extension: allocated_size 0x%llx, " 2326 "data_size 0x%llx, initialized_size 0x%llx.", 2327 (long long)old_data_size, 2328 (long long)i_size_read(vol->mftbmp_ino), 2329 (long long)old_data_initialized); 2330 read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 2331 if (old_data_initialized + 8 > old_data_size) { 2332 /* Need to extend bitmap by one more cluster. */ 2333 ntfs_debug("mftbmp: initialized_size + 8 > allocated_size."); 2334 err = ntfs_mft_bitmap_extend_allocation_nolock(vol); 2335 if (unlikely(err)) { 2336 up_write(&vol->mftbmp_lock); 2337 goto err_out; 2338 } 2339 #ifdef DEBUG 2340 read_lock_irqsave(&mftbmp_ni->size_lock, flags); 2341 ntfs_debug("Status of mftbmp after allocation extension: " 2342 "allocated_size 0x%llx, data_size 0x%llx, " 2343 "initialized_size 0x%llx.", 2344 (long long)mftbmp_ni->allocated_size, 2345 (long long)i_size_read(vol->mftbmp_ino), 2346 (long long)mftbmp_ni->initialized_size); 2347 read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 2348 #endif /* DEBUG */ 2349 } 2350 /* 2351 * We now have sufficient allocated space, extend the initialized_size 2352 * as well as the data_size if necessary and fill the new space with 2353 * zeroes. 2354 */ 2355 err = ntfs_mft_bitmap_extend_initialized_nolock(vol); 2356 if (unlikely(err)) { 2357 up_write(&vol->mftbmp_lock); 2358 goto err_out; 2359 } 2360 #ifdef DEBUG 2361 read_lock_irqsave(&mftbmp_ni->size_lock, flags); 2362 ntfs_debug("Status of mftbmp after initialized extention: " 2363 "allocated_size 0x%llx, data_size 0x%llx, " 2364 "initialized_size 0x%llx.", 2365 (long long)mftbmp_ni->allocated_size, 2366 (long long)i_size_read(vol->mftbmp_ino), 2367 (long long)mftbmp_ni->initialized_size); 2368 read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 2369 #endif /* DEBUG */ 2370 ntfs_debug("Found free record (#3), bit 0x%llx.", (long long)bit); 2371 found_free_rec: 2372 /* @bit is the found free mft record, allocate it in the mft bitmap. */ 2373 ntfs_debug("At found_free_rec."); 2374 err = ntfs_bitmap_set_bit(vol->mftbmp_ino, bit); 2375 if (unlikely(err)) { 2376 ntfs_error(vol->sb, "Failed to allocate bit in mft bitmap."); 2377 up_write(&vol->mftbmp_lock); 2378 goto err_out; 2379 } 2380 ntfs_debug("Set bit 0x%llx in mft bitmap.", (long long)bit); 2381 have_alloc_rec: 2382 /* 2383 * The mft bitmap is now uptodate. Deal with mft data attribute now. 2384 * Note, we keep hold of the mft bitmap lock for writing until all 2385 * modifications to the mft data attribute are complete, too, as they 2386 * will impact decisions for mft bitmap and mft record allocation done 2387 * by a parallel allocation and if the lock is not maintained a 2388 * parallel allocation could allocate the same mft record as this one. 2389 */ 2390 ll = (bit + 1) << vol->mft_record_size_bits; 2391 read_lock_irqsave(&mft_ni->size_lock, flags); 2392 old_data_initialized = mft_ni->initialized_size; 2393 read_unlock_irqrestore(&mft_ni->size_lock, flags); 2394 if (ll <= old_data_initialized) { 2395 ntfs_debug("Allocated mft record already initialized."); 2396 goto mft_rec_already_initialized; 2397 } 2398 ntfs_debug("Initializing allocated mft record."); 2399 /* 2400 * The mft record is outside the initialized data. Extend the mft data 2401 * attribute until it covers the allocated record. The loop is only 2402 * actually traversed more than once when a freshly formatted volume is 2403 * first written to so it optimizes away nicely in the common case. 2404 */ 2405 read_lock_irqsave(&mft_ni->size_lock, flags); 2406 ntfs_debug("Status of mft data before extension: " 2407 "allocated_size 0x%llx, data_size 0x%llx, " 2408 "initialized_size 0x%llx.", 2409 (long long)mft_ni->allocated_size, 2410 (long long)i_size_read(vol->mft_ino), 2411 (long long)mft_ni->initialized_size); 2412 while (ll > mft_ni->allocated_size) { 2413 read_unlock_irqrestore(&mft_ni->size_lock, flags); 2414 err = ntfs_mft_data_extend_allocation_nolock(vol); 2415 if (unlikely(err)) { 2416 ntfs_error(vol->sb, "Failed to extend mft data " 2417 "allocation."); 2418 goto undo_mftbmp_alloc_nolock; 2419 } 2420 read_lock_irqsave(&mft_ni->size_lock, flags); 2421 ntfs_debug("Status of mft data after allocation extension: " 2422 "allocated_size 0x%llx, data_size 0x%llx, " 2423 "initialized_size 0x%llx.", 2424 (long long)mft_ni->allocated_size, 2425 (long long)i_size_read(vol->mft_ino), 2426 (long long)mft_ni->initialized_size); 2427 } 2428 read_unlock_irqrestore(&mft_ni->size_lock, flags); 2429 /* 2430 * Extend mft data initialized size (and data size of course) to reach 2431 * the allocated mft record, formatting the mft records allong the way. 2432 * Note: We only modify the ntfs_inode structure as that is all that is 2433 * needed by ntfs_mft_record_format(). We will update the attribute 2434 * record itself in one fell swoop later on. 2435 */ 2436 write_lock_irqsave(&mft_ni->size_lock, flags); 2437 old_data_initialized = mft_ni->initialized_size; 2438 old_data_size = vol->mft_ino->i_size; 2439 while (ll > mft_ni->initialized_size) { 2440 s64 new_initialized_size, mft_no; 2441 2442 new_initialized_size = mft_ni->initialized_size + 2443 vol->mft_record_size; 2444 mft_no = mft_ni->initialized_size >> vol->mft_record_size_bits; 2445 if (new_initialized_size > i_size_read(vol->mft_ino)) 2446 i_size_write(vol->mft_ino, new_initialized_size); 2447 write_unlock_irqrestore(&mft_ni->size_lock, flags); 2448 ntfs_debug("Initializing mft record 0x%llx.", 2449 (long long)mft_no); 2450 err = ntfs_mft_record_format(vol, mft_no); 2451 if (unlikely(err)) { 2452 ntfs_error(vol->sb, "Failed to format mft record."); 2453 goto undo_data_init; 2454 } 2455 write_lock_irqsave(&mft_ni->size_lock, flags); 2456 mft_ni->initialized_size = new_initialized_size; 2457 } 2458 write_unlock_irqrestore(&mft_ni->size_lock, flags); 2459 record_formatted = TRUE; 2460 /* Update the mft data attribute record to reflect the new sizes. */ 2461 m = map_mft_record(mft_ni); 2462 if (IS_ERR(m)) { 2463 ntfs_error(vol->sb, "Failed to map mft record."); 2464 err = PTR_ERR(m); 2465 goto undo_data_init; 2466 } 2467 ctx = ntfs_attr_get_search_ctx(mft_ni, m); 2468 if (unlikely(!ctx)) { 2469 ntfs_error(vol->sb, "Failed to get search context."); 2470 err = -ENOMEM; 2471 unmap_mft_record(mft_ni); 2472 goto undo_data_init; 2473 } 2474 err = ntfs_attr_lookup(mft_ni->type, mft_ni->name, mft_ni->name_len, 2475 CASE_SENSITIVE, 0, NULL, 0, ctx); 2476 if (unlikely(err)) { 2477 ntfs_error(vol->sb, "Failed to find first attribute extent of " 2478 "mft data attribute."); 2479 ntfs_attr_put_search_ctx(ctx); 2480 unmap_mft_record(mft_ni); 2481 goto undo_data_init; 2482 } 2483 a = ctx->attr; 2484 read_lock_irqsave(&mft_ni->size_lock, flags); 2485 a->data.non_resident.initialized_size = 2486 cpu_to_sle64(mft_ni->initialized_size); 2487 a->data.non_resident.data_size = 2488 cpu_to_sle64(i_size_read(vol->mft_ino)); 2489 read_unlock_irqrestore(&mft_ni->size_lock, flags); 2490 /* Ensure the changes make it to disk. */ 2491 flush_dcache_mft_record_page(ctx->ntfs_ino); 2492 mark_mft_record_dirty(ctx->ntfs_ino); 2493 ntfs_attr_put_search_ctx(ctx); 2494 unmap_mft_record(mft_ni); 2495 read_lock_irqsave(&mft_ni->size_lock, flags); 2496 ntfs_debug("Status of mft data after mft record initialization: " 2497 "allocated_size 0x%llx, data_size 0x%llx, " 2498 "initialized_size 0x%llx.", 2499 (long long)mft_ni->allocated_size, 2500 (long long)i_size_read(vol->mft_ino), 2501 (long long)mft_ni->initialized_size); 2502 BUG_ON(i_size_read(vol->mft_ino) > mft_ni->allocated_size); 2503 BUG_ON(mft_ni->initialized_size > i_size_read(vol->mft_ino)); 2504 read_unlock_irqrestore(&mft_ni->size_lock, flags); 2505 mft_rec_already_initialized: 2506 /* 2507 * We can finally drop the mft bitmap lock as the mft data attribute 2508 * has been fully updated. The only disparity left is that the 2509 * allocated mft record still needs to be marked as in use to match the 2510 * set bit in the mft bitmap but this is actually not a problem since 2511 * this mft record is not referenced from anywhere yet and the fact 2512 * that it is allocated in the mft bitmap means that no-one will try to 2513 * allocate it either. 2514 */ 2515 up_write(&vol->mftbmp_lock); 2516 /* 2517 * We now have allocated and initialized the mft record. Calculate the 2518 * index of and the offset within the page cache page the record is in. 2519 */ 2520 index = bit << vol->mft_record_size_bits >> PAGE_CACHE_SHIFT; 2521 ofs = (bit << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK; 2522 /* Read, map, and pin the page containing the mft record. */ 2523 page = ntfs_map_page(vol->mft_ino->i_mapping, index); 2524 if (unlikely(IS_ERR(page))) { 2525 ntfs_error(vol->sb, "Failed to map page containing allocated " 2526 "mft record 0x%llx.", (long long)bit); 2527 err = PTR_ERR(page); 2528 goto undo_mftbmp_alloc; 2529 } 2530 lock_page(page); 2531 BUG_ON(!PageUptodate(page)); 2532 ClearPageUptodate(page); 2533 m = (MFT_RECORD*)((u8*)page_address(page) + ofs); 2534 /* If we just formatted the mft record no need to do it again. */ 2535 if (!record_formatted) { 2536 /* Sanity check that the mft record is really not in use. */ 2537 if (ntfs_is_file_record(m->magic) && 2538 (m->flags & MFT_RECORD_IN_USE)) { 2539 ntfs_error(vol->sb, "Mft record 0x%llx was marked " 2540 "free in mft bitmap but is marked " 2541 "used itself. Corrupt filesystem. " 2542 "Unmount and run chkdsk.", 2543 (long long)bit); 2544 err = -EIO; 2545 SetPageUptodate(page); 2546 unlock_page(page); 2547 ntfs_unmap_page(page); 2548 NVolSetErrors(vol); 2549 goto undo_mftbmp_alloc; 2550 } 2551 /* 2552 * We need to (re-)format the mft record, preserving the 2553 * sequence number if it is not zero as well as the update 2554 * sequence number if it is not zero or -1 (0xffff). This 2555 * means we do not need to care whether or not something went 2556 * wrong with the previous mft record. 2557 */ 2558 seq_no = m->sequence_number; 2559 usn = *(le16*)((u8*)m + le16_to_cpu(m->usa_ofs)); 2560 err = ntfs_mft_record_layout(vol, bit, m); 2561 if (unlikely(err)) { 2562 ntfs_error(vol->sb, "Failed to layout allocated mft " 2563 "record 0x%llx.", (long long)bit); 2564 SetPageUptodate(page); 2565 unlock_page(page); 2566 ntfs_unmap_page(page); 2567 goto undo_mftbmp_alloc; 2568 } 2569 if (seq_no) 2570 m->sequence_number = seq_no; 2571 if (usn && le16_to_cpu(usn) != 0xffff) 2572 *(le16*)((u8*)m + le16_to_cpu(m->usa_ofs)) = usn; 2573 } 2574 /* Set the mft record itself in use. */ 2575 m->flags |= MFT_RECORD_IN_USE; 2576 if (S_ISDIR(mode)) 2577 m->flags |= MFT_RECORD_IS_DIRECTORY; 2578 flush_dcache_page(page); 2579 SetPageUptodate(page); 2580 if (base_ni) { 2581 /* 2582 * Setup the base mft record in the extent mft record. This 2583 * completes initialization of the allocated extent mft record 2584 * and we can simply use it with map_extent_mft_record(). 2585 */ 2586 m->base_mft_record = MK_LE_MREF(base_ni->mft_no, 2587 base_ni->seq_no); 2588 /* 2589 * Allocate an extent inode structure for the new mft record, 2590 * attach it to the base inode @base_ni and map, pin, and lock 2591 * its, i.e. the allocated, mft record. 2592 */ 2593 m = map_extent_mft_record(base_ni, bit, &ni); 2594 if (IS_ERR(m)) { 2595 ntfs_error(vol->sb, "Failed to map allocated extent " 2596 "mft record 0x%llx.", (long long)bit); 2597 err = PTR_ERR(m); 2598 /* Set the mft record itself not in use. */ 2599 m->flags &= cpu_to_le16( 2600 ~le16_to_cpu(MFT_RECORD_IN_USE)); 2601 flush_dcache_page(page); 2602 /* Make sure the mft record is written out to disk. */ 2603 mark_ntfs_record_dirty(page, ofs); 2604 unlock_page(page); 2605 ntfs_unmap_page(page); 2606 goto undo_mftbmp_alloc; 2607 } 2608 /* 2609 * Make sure the allocated mft record is written out to disk. 2610 * No need to set the inode dirty because the caller is going 2611 * to do that anyway after finishing with the new extent mft 2612 * record (e.g. at a minimum a new attribute will be added to 2613 * the mft record. 2614 */ 2615 mark_ntfs_record_dirty(page, ofs); 2616 unlock_page(page); 2617 /* 2618 * Need to unmap the page since map_extent_mft_record() mapped 2619 * it as well so we have it mapped twice at the moment. 2620 */ 2621 ntfs_unmap_page(page); 2622 } else { 2623 /* 2624 * Allocate a new VFS inode and set it up. NOTE: @vi->i_nlink 2625 * is set to 1 but the mft record->link_count is 0. The caller 2626 * needs to bear this in mind. 2627 */ 2628 vi = new_inode(vol->sb); 2629 if (unlikely(!vi)) { 2630 err = -ENOMEM; 2631 /* Set the mft record itself not in use. */ 2632 m->flags &= cpu_to_le16( 2633 ~le16_to_cpu(MFT_RECORD_IN_USE)); 2634 flush_dcache_page(page); 2635 /* Make sure the mft record is written out to disk. */ 2636 mark_ntfs_record_dirty(page, ofs); 2637 unlock_page(page); 2638 ntfs_unmap_page(page); 2639 goto undo_mftbmp_alloc; 2640 } 2641 vi->i_ino = bit; 2642 /* 2643 * This is the optimal IO size (for stat), not the fs block 2644 * size. 2645 */ 2646 vi->i_blksize = PAGE_CACHE_SIZE; 2647 /* 2648 * This is for checking whether an inode has changed w.r.t. a 2649 * file so that the file can be updated if necessary (compare 2650 * with f_version). 2651 */ 2652 vi->i_version = 1; 2653 2654 /* The owner and group come from the ntfs volume. */ 2655 vi->i_uid = vol->uid; 2656 vi->i_gid = vol->gid; 2657 2658 /* Initialize the ntfs specific part of @vi. */ 2659 ntfs_init_big_inode(vi); 2660 ni = NTFS_I(vi); 2661 /* 2662 * Set the appropriate mode, attribute type, and name. For 2663 * directories, also setup the index values to the defaults. 2664 */ 2665 if (S_ISDIR(mode)) { 2666 vi->i_mode = S_IFDIR | S_IRWXUGO; 2667 vi->i_mode &= ~vol->dmask; 2668 2669 NInoSetMstProtected(ni); 2670 ni->type = AT_INDEX_ALLOCATION; 2671 ni->name = I30; 2672 ni->name_len = 4; 2673 2674 ni->itype.index.block_size = 4096; 2675 ni->itype.index.block_size_bits = generic_ffs(4096) - 1; 2676 ni->itype.index.collation_rule = COLLATION_FILE_NAME; 2677 if (vol->cluster_size <= ni->itype.index.block_size) { 2678 ni->itype.index.vcn_size = vol->cluster_size; 2679 ni->itype.index.vcn_size_bits = 2680 vol->cluster_size_bits; 2681 } else { 2682 ni->itype.index.vcn_size = vol->sector_size; 2683 ni->itype.index.vcn_size_bits = 2684 vol->sector_size_bits; 2685 } 2686 } else { 2687 vi->i_mode = S_IFREG | S_IRWXUGO; 2688 vi->i_mode &= ~vol->fmask; 2689 2690 ni->type = AT_DATA; 2691 ni->name = NULL; 2692 ni->name_len = 0; 2693 } 2694 if (IS_RDONLY(vi)) 2695 vi->i_mode &= ~S_IWUGO; 2696 2697 /* Set the inode times to the current time. */ 2698 vi->i_atime = vi->i_mtime = vi->i_ctime = 2699 current_fs_time(vi->i_sb); 2700 /* 2701 * Set the file size to 0, the ntfs inode sizes are set to 0 by 2702 * the call to ntfs_init_big_inode() below. 2703 */ 2704 vi->i_size = 0; 2705 vi->i_blocks = 0; 2706 2707 /* Set the sequence number. */ 2708 vi->i_generation = ni->seq_no = le16_to_cpu(m->sequence_number); 2709 /* 2710 * Manually map, pin, and lock the mft record as we already 2711 * have its page mapped and it is very easy to do. 2712 */ 2713 atomic_inc(&ni->count); 2714 down(&ni->mrec_lock); 2715 ni->page = page; 2716 ni->page_ofs = ofs; 2717 /* 2718 * Make sure the allocated mft record is written out to disk. 2719 * NOTE: We do not set the ntfs inode dirty because this would 2720 * fail in ntfs_write_inode() because the inode does not have a 2721 * standard information attribute yet. Also, there is no need 2722 * to set the inode dirty because the caller is going to do 2723 * that anyway after finishing with the new mft record (e.g. at 2724 * a minimum some new attributes will be added to the mft 2725 * record. 2726 */ 2727 mark_ntfs_record_dirty(page, ofs); 2728 unlock_page(page); 2729 2730 /* Add the inode to the inode hash for the superblock. */ 2731 insert_inode_hash(vi); 2732 2733 /* Update the default mft allocation position. */ 2734 vol->mft_data_pos = bit + 1; 2735 } 2736 /* 2737 * Return the opened, allocated inode of the allocated mft record as 2738 * well as the mapped, pinned, and locked mft record. 2739 */ 2740 ntfs_debug("Returning opened, allocated %sinode 0x%llx.", 2741 base_ni ? "extent " : "", (long long)bit); 2742 *mrec = m; 2743 return ni; 2744 undo_data_init: 2745 write_lock_irqsave(&mft_ni->size_lock, flags); 2746 mft_ni->initialized_size = old_data_initialized; 2747 i_size_write(vol->mft_ino, old_data_size); 2748 write_unlock_irqrestore(&mft_ni->size_lock, flags); 2749 goto undo_mftbmp_alloc_nolock; 2750 undo_mftbmp_alloc: 2751 down_write(&vol->mftbmp_lock); 2752 undo_mftbmp_alloc_nolock: 2753 if (ntfs_bitmap_clear_bit(vol->mftbmp_ino, bit)) { 2754 ntfs_error(vol->sb, "Failed to clear bit in mft bitmap.%s", es); 2755 NVolSetErrors(vol); 2756 } 2757 up_write(&vol->mftbmp_lock); 2758 err_out: 2759 return ERR_PTR(err); 2760 max_err_out: 2761 ntfs_warning(vol->sb, "Cannot allocate mft record because the maximum " 2762 "number of inodes (2^32) has already been reached."); 2763 up_write(&vol->mftbmp_lock); 2764 return ERR_PTR(-ENOSPC); 2765 } 2766 2767 /** 2768 * ntfs_extent_mft_record_free - free an extent mft record on an ntfs volume 2769 * @ni: ntfs inode of the mapped extent mft record to free 2770 * @m: mapped extent mft record of the ntfs inode @ni 2771 * 2772 * Free the mapped extent mft record @m of the extent ntfs inode @ni. 2773 * 2774 * Note that this function unmaps the mft record and closes and destroys @ni 2775 * internally and hence you cannot use either @ni nor @m any more after this 2776 * function returns success. 2777 * 2778 * On success return 0 and on error return -errno. @ni and @m are still valid 2779 * in this case and have not been freed. 2780 * 2781 * For some errors an error message is displayed and the success code 0 is 2782 * returned and the volume is then left dirty on umount. This makes sense in 2783 * case we could not rollback the changes that were already done since the 2784 * caller no longer wants to reference this mft record so it does not matter to 2785 * the caller if something is wrong with it as long as it is properly detached 2786 * from the base inode. 2787 */ 2788 int ntfs_extent_mft_record_free(ntfs_inode *ni, MFT_RECORD *m) 2789 { 2790 unsigned long mft_no = ni->mft_no; 2791 ntfs_volume *vol = ni->vol; 2792 ntfs_inode *base_ni; 2793 ntfs_inode **extent_nis; 2794 int i, err; 2795 le16 old_seq_no; 2796 u16 seq_no; 2797 2798 BUG_ON(NInoAttr(ni)); 2799 BUG_ON(ni->nr_extents != -1); 2800 2801 down(&ni->extent_lock); 2802 base_ni = ni->ext.base_ntfs_ino; 2803 up(&ni->extent_lock); 2804 2805 BUG_ON(base_ni->nr_extents <= 0); 2806 2807 ntfs_debug("Entering for extent inode 0x%lx, base inode 0x%lx.\n", 2808 mft_no, base_ni->mft_no); 2809 2810 down(&base_ni->extent_lock); 2811 2812 /* Make sure we are holding the only reference to the extent inode. */ 2813 if (atomic_read(&ni->count) > 2) { 2814 ntfs_error(vol->sb, "Tried to free busy extent inode 0x%lx, " 2815 "not freeing.", base_ni->mft_no); 2816 up(&base_ni->extent_lock); 2817 return -EBUSY; 2818 } 2819 2820 /* Dissociate the ntfs inode from the base inode. */ 2821 extent_nis = base_ni->ext.extent_ntfs_inos; 2822 err = -ENOENT; 2823 for (i = 0; i < base_ni->nr_extents; i++) { 2824 if (ni != extent_nis[i]) 2825 continue; 2826 extent_nis += i; 2827 base_ni->nr_extents--; 2828 memmove(extent_nis, extent_nis + 1, (base_ni->nr_extents - i) * 2829 sizeof(ntfs_inode*)); 2830 err = 0; 2831 break; 2832 } 2833 2834 up(&base_ni->extent_lock); 2835 2836 if (unlikely(err)) { 2837 ntfs_error(vol->sb, "Extent inode 0x%lx is not attached to " 2838 "its base inode 0x%lx.", mft_no, 2839 base_ni->mft_no); 2840 BUG(); 2841 } 2842 2843 /* 2844 * The extent inode is no longer attached to the base inode so no one 2845 * can get a reference to it any more. 2846 */ 2847 2848 /* Mark the mft record as not in use. */ 2849 m->flags &= const_cpu_to_le16(~const_le16_to_cpu(MFT_RECORD_IN_USE)); 2850 2851 /* Increment the sequence number, skipping zero, if it is not zero. */ 2852 old_seq_no = m->sequence_number; 2853 seq_no = le16_to_cpu(old_seq_no); 2854 if (seq_no == 0xffff) 2855 seq_no = 1; 2856 else if (seq_no) 2857 seq_no++; 2858 m->sequence_number = cpu_to_le16(seq_no); 2859 2860 /* 2861 * Set the ntfs inode dirty and write it out. We do not need to worry 2862 * about the base inode here since whatever caused the extent mft 2863 * record to be freed is guaranteed to do it already. 2864 */ 2865 NInoSetDirty(ni); 2866 err = write_mft_record(ni, m, 0); 2867 if (unlikely(err)) { 2868 ntfs_error(vol->sb, "Failed to write mft record 0x%lx, not " 2869 "freeing.", mft_no); 2870 goto rollback; 2871 } 2872 rollback_error: 2873 /* Unmap and throw away the now freed extent inode. */ 2874 unmap_extent_mft_record(ni); 2875 ntfs_clear_extent_inode(ni); 2876 2877 /* Clear the bit in the $MFT/$BITMAP corresponding to this record. */ 2878 down_write(&vol->mftbmp_lock); 2879 err = ntfs_bitmap_clear_bit(vol->mftbmp_ino, mft_no); 2880 up_write(&vol->mftbmp_lock); 2881 if (unlikely(err)) { 2882 /* 2883 * The extent inode is gone but we failed to deallocate it in 2884 * the mft bitmap. Just emit a warning and leave the volume 2885 * dirty on umount. 2886 */ 2887 ntfs_error(vol->sb, "Failed to clear bit in mft bitmap.%s", es); 2888 NVolSetErrors(vol); 2889 } 2890 return 0; 2891 rollback: 2892 /* Rollback what we did... */ 2893 down(&base_ni->extent_lock); 2894 extent_nis = base_ni->ext.extent_ntfs_inos; 2895 if (!(base_ni->nr_extents & 3)) { 2896 int new_size = (base_ni->nr_extents + 4) * sizeof(ntfs_inode*); 2897 2898 extent_nis = (ntfs_inode**)kmalloc(new_size, GFP_NOFS); 2899 if (unlikely(!extent_nis)) { 2900 ntfs_error(vol->sb, "Failed to allocate internal " 2901 "buffer during rollback.%s", es); 2902 up(&base_ni->extent_lock); 2903 NVolSetErrors(vol); 2904 goto rollback_error; 2905 } 2906 if (base_ni->nr_extents) { 2907 BUG_ON(!base_ni->ext.extent_ntfs_inos); 2908 memcpy(extent_nis, base_ni->ext.extent_ntfs_inos, 2909 new_size - 4 * sizeof(ntfs_inode*)); 2910 kfree(base_ni->ext.extent_ntfs_inos); 2911 } 2912 base_ni->ext.extent_ntfs_inos = extent_nis; 2913 } 2914 m->flags |= MFT_RECORD_IN_USE; 2915 m->sequence_number = old_seq_no; 2916 extent_nis[base_ni->nr_extents++] = ni; 2917 up(&base_ni->extent_lock); 2918 mark_mft_record_dirty(ni); 2919 return err; 2920 } 2921 #endif /* NTFS_RW */ 2922