1 /* 2 * file.c - NTFS kernel file operations. Part of the Linux-NTFS project. 3 * 4 * Copyright (c) 2001-2005 Anton Altaparmakov 5 * 6 * This program/include file is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as published 8 * by the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program/include file is distributed in the hope that it will be 12 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty 13 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program (in the main directory of the Linux-NTFS 18 * distribution in the file COPYING); if not, write to the Free Software 19 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 */ 21 22 #include <linux/buffer_head.h> 23 #include <linux/pagemap.h> 24 #include <linux/pagevec.h> 25 #include <linux/sched.h> 26 #include <linux/swap.h> 27 #include <linux/uio.h> 28 #include <linux/writeback.h> 29 30 #include <asm/page.h> 31 #include <asm/uaccess.h> 32 33 #include "attrib.h" 34 #include "bitmap.h" 35 #include "inode.h" 36 #include "debug.h" 37 #include "lcnalloc.h" 38 #include "malloc.h" 39 #include "mft.h" 40 #include "ntfs.h" 41 42 /** 43 * ntfs_file_open - called when an inode is about to be opened 44 * @vi: inode to be opened 45 * @filp: file structure describing the inode 46 * 47 * Limit file size to the page cache limit on architectures where unsigned long 48 * is 32-bits. This is the most we can do for now without overflowing the page 49 * cache page index. Doing it this way means we don't run into problems because 50 * of existing too large files. It would be better to allow the user to read 51 * the beginning of the file but I doubt very much anyone is going to hit this 52 * check on a 32-bit architecture, so there is no point in adding the extra 53 * complexity required to support this. 54 * 55 * On 64-bit architectures, the check is hopefully optimized away by the 56 * compiler. 57 * 58 * After the check passes, just call generic_file_open() to do its work. 59 */ 60 static int ntfs_file_open(struct inode *vi, struct file *filp) 61 { 62 if (sizeof(unsigned long) < 8) { 63 if (i_size_read(vi) > MAX_LFS_FILESIZE) 64 return -EFBIG; 65 } 66 return generic_file_open(vi, filp); 67 } 68 69 #ifdef NTFS_RW 70 71 /** 72 * ntfs_attr_extend_initialized - extend the initialized size of an attribute 73 * @ni: ntfs inode of the attribute to extend 74 * @new_init_size: requested new initialized size in bytes 75 * @cached_page: store any allocated but unused page here 76 * @lru_pvec: lru-buffering pagevec of the caller 77 * 78 * Extend the initialized size of an attribute described by the ntfs inode @ni 79 * to @new_init_size bytes. This involves zeroing any non-sparse space between 80 * the old initialized size and @new_init_size both in the page cache and on 81 * disk (if relevant complete pages are already uptodate in the page cache then 82 * these are simply marked dirty). 83 * 84 * As a side-effect, the file size (vfs inode->i_size) may be incremented as, 85 * in the resident attribute case, it is tied to the initialized size and, in 86 * the non-resident attribute case, it may not fall below the initialized size. 87 * 88 * Note that if the attribute is resident, we do not need to touch the page 89 * cache at all. This is because if the page cache page is not uptodate we 90 * bring it uptodate later, when doing the write to the mft record since we 91 * then already have the page mapped. And if the page is uptodate, the 92 * non-initialized region will already have been zeroed when the page was 93 * brought uptodate and the region may in fact already have been overwritten 94 * with new data via mmap() based writes, so we cannot just zero it. And since 95 * POSIX specifies that the behaviour of resizing a file whilst it is mmap()ped 96 * is unspecified, we choose not to do zeroing and thus we do not need to touch 97 * the page at all. For a more detailed explanation see ntfs_truncate() in 98 * fs/ntfs/inode.c. 99 * 100 * @cached_page and @lru_pvec are just optimizations for dealing with multiple 101 * pages. 102 * 103 * Return 0 on success and -errno on error. In the case that an error is 104 * encountered it is possible that the initialized size will already have been 105 * incremented some way towards @new_init_size but it is guaranteed that if 106 * this is the case, the necessary zeroing will also have happened and that all 107 * metadata is self-consistent. 108 * 109 * Locking: i_sem on the vfs inode corrseponsind to the ntfs inode @ni must be 110 * held by the caller. 111 */ 112 static int ntfs_attr_extend_initialized(ntfs_inode *ni, const s64 new_init_size, 113 struct page **cached_page, struct pagevec *lru_pvec) 114 { 115 s64 old_init_size; 116 loff_t old_i_size; 117 pgoff_t index, end_index; 118 unsigned long flags; 119 struct inode *vi = VFS_I(ni); 120 ntfs_inode *base_ni; 121 MFT_RECORD *m = NULL; 122 ATTR_RECORD *a; 123 ntfs_attr_search_ctx *ctx = NULL; 124 struct address_space *mapping; 125 struct page *page = NULL; 126 u8 *kattr; 127 int err; 128 u32 attr_len; 129 130 read_lock_irqsave(&ni->size_lock, flags); 131 old_init_size = ni->initialized_size; 132 old_i_size = i_size_read(vi); 133 BUG_ON(new_init_size > ni->allocated_size); 134 read_unlock_irqrestore(&ni->size_lock, flags); 135 ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, " 136 "old_initialized_size 0x%llx, " 137 "new_initialized_size 0x%llx, i_size 0x%llx.", 138 vi->i_ino, (unsigned)le32_to_cpu(ni->type), 139 (unsigned long long)old_init_size, 140 (unsigned long long)new_init_size, old_i_size); 141 if (!NInoAttr(ni)) 142 base_ni = ni; 143 else 144 base_ni = ni->ext.base_ntfs_ino; 145 /* Use goto to reduce indentation and we need the label below anyway. */ 146 if (NInoNonResident(ni)) 147 goto do_non_resident_extend; 148 BUG_ON(old_init_size != old_i_size); 149 m = map_mft_record(base_ni); 150 if (IS_ERR(m)) { 151 err = PTR_ERR(m); 152 m = NULL; 153 goto err_out; 154 } 155 ctx = ntfs_attr_get_search_ctx(base_ni, m); 156 if (unlikely(!ctx)) { 157 err = -ENOMEM; 158 goto err_out; 159 } 160 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, 161 CASE_SENSITIVE, 0, NULL, 0, ctx); 162 if (unlikely(err)) { 163 if (err == -ENOENT) 164 err = -EIO; 165 goto err_out; 166 } 167 m = ctx->mrec; 168 a = ctx->attr; 169 BUG_ON(a->non_resident); 170 /* The total length of the attribute value. */ 171 attr_len = le32_to_cpu(a->data.resident.value_length); 172 BUG_ON(old_i_size != (loff_t)attr_len); 173 /* 174 * Do the zeroing in the mft record and update the attribute size in 175 * the mft record. 176 */ 177 kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset); 178 memset(kattr + attr_len, 0, new_init_size - attr_len); 179 a->data.resident.value_length = cpu_to_le32((u32)new_init_size); 180 /* Finally, update the sizes in the vfs and ntfs inodes. */ 181 write_lock_irqsave(&ni->size_lock, flags); 182 i_size_write(vi, new_init_size); 183 ni->initialized_size = new_init_size; 184 write_unlock_irqrestore(&ni->size_lock, flags); 185 goto done; 186 do_non_resident_extend: 187 /* 188 * If the new initialized size @new_init_size exceeds the current file 189 * size (vfs inode->i_size), we need to extend the file size to the 190 * new initialized size. 191 */ 192 if (new_init_size > old_i_size) { 193 m = map_mft_record(base_ni); 194 if (IS_ERR(m)) { 195 err = PTR_ERR(m); 196 m = NULL; 197 goto err_out; 198 } 199 ctx = ntfs_attr_get_search_ctx(base_ni, m); 200 if (unlikely(!ctx)) { 201 err = -ENOMEM; 202 goto err_out; 203 } 204 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, 205 CASE_SENSITIVE, 0, NULL, 0, ctx); 206 if (unlikely(err)) { 207 if (err == -ENOENT) 208 err = -EIO; 209 goto err_out; 210 } 211 m = ctx->mrec; 212 a = ctx->attr; 213 BUG_ON(!a->non_resident); 214 BUG_ON(old_i_size != (loff_t) 215 sle64_to_cpu(a->data.non_resident.data_size)); 216 a->data.non_resident.data_size = cpu_to_sle64(new_init_size); 217 flush_dcache_mft_record_page(ctx->ntfs_ino); 218 mark_mft_record_dirty(ctx->ntfs_ino); 219 /* Update the file size in the vfs inode. */ 220 i_size_write(vi, new_init_size); 221 ntfs_attr_put_search_ctx(ctx); 222 ctx = NULL; 223 unmap_mft_record(base_ni); 224 m = NULL; 225 } 226 mapping = vi->i_mapping; 227 index = old_init_size >> PAGE_CACHE_SHIFT; 228 end_index = (new_init_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; 229 do { 230 /* 231 * Read the page. If the page is not present, this will zero 232 * the uninitialized regions for us. 233 */ 234 page = read_cache_page(mapping, index, 235 (filler_t*)mapping->a_ops->readpage, NULL); 236 if (IS_ERR(page)) { 237 err = PTR_ERR(page); 238 goto init_err_out; 239 } 240 wait_on_page_locked(page); 241 if (unlikely(!PageUptodate(page) || PageError(page))) { 242 page_cache_release(page); 243 err = -EIO; 244 goto init_err_out; 245 } 246 /* 247 * Update the initialized size in the ntfs inode. This is 248 * enough to make ntfs_writepage() work. 249 */ 250 write_lock_irqsave(&ni->size_lock, flags); 251 ni->initialized_size = (index + 1) << PAGE_CACHE_SHIFT; 252 if (ni->initialized_size > new_init_size) 253 ni->initialized_size = new_init_size; 254 write_unlock_irqrestore(&ni->size_lock, flags); 255 /* Set the page dirty so it gets written out. */ 256 set_page_dirty(page); 257 page_cache_release(page); 258 /* 259 * Play nice with the vm and the rest of the system. This is 260 * very much needed as we can potentially be modifying the 261 * initialised size from a very small value to a really huge 262 * value, e.g. 263 * f = open(somefile, O_TRUNC); 264 * truncate(f, 10GiB); 265 * seek(f, 10GiB); 266 * write(f, 1); 267 * And this would mean we would be marking dirty hundreds of 268 * thousands of pages or as in the above example more than 269 * two and a half million pages! 270 * 271 * TODO: For sparse pages could optimize this workload by using 272 * the FsMisc / MiscFs page bit as a "PageIsSparse" bit. This 273 * would be set in readpage for sparse pages and here we would 274 * not need to mark dirty any pages which have this bit set. 275 * The only caveat is that we have to clear the bit everywhere 276 * where we allocate any clusters that lie in the page or that 277 * contain the page. 278 * 279 * TODO: An even greater optimization would be for us to only 280 * call readpage() on pages which are not in sparse regions as 281 * determined from the runlist. This would greatly reduce the 282 * number of pages we read and make dirty in the case of sparse 283 * files. 284 */ 285 balance_dirty_pages_ratelimited(mapping); 286 cond_resched(); 287 } while (++index < end_index); 288 read_lock_irqsave(&ni->size_lock, flags); 289 BUG_ON(ni->initialized_size != new_init_size); 290 read_unlock_irqrestore(&ni->size_lock, flags); 291 /* Now bring in sync the initialized_size in the mft record. */ 292 m = map_mft_record(base_ni); 293 if (IS_ERR(m)) { 294 err = PTR_ERR(m); 295 m = NULL; 296 goto init_err_out; 297 } 298 ctx = ntfs_attr_get_search_ctx(base_ni, m); 299 if (unlikely(!ctx)) { 300 err = -ENOMEM; 301 goto init_err_out; 302 } 303 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, 304 CASE_SENSITIVE, 0, NULL, 0, ctx); 305 if (unlikely(err)) { 306 if (err == -ENOENT) 307 err = -EIO; 308 goto init_err_out; 309 } 310 m = ctx->mrec; 311 a = ctx->attr; 312 BUG_ON(!a->non_resident); 313 a->data.non_resident.initialized_size = cpu_to_sle64(new_init_size); 314 done: 315 flush_dcache_mft_record_page(ctx->ntfs_ino); 316 mark_mft_record_dirty(ctx->ntfs_ino); 317 if (ctx) 318 ntfs_attr_put_search_ctx(ctx); 319 if (m) 320 unmap_mft_record(base_ni); 321 ntfs_debug("Done, initialized_size 0x%llx, i_size 0x%llx.", 322 (unsigned long long)new_init_size, i_size_read(vi)); 323 return 0; 324 init_err_out: 325 write_lock_irqsave(&ni->size_lock, flags); 326 ni->initialized_size = old_init_size; 327 write_unlock_irqrestore(&ni->size_lock, flags); 328 err_out: 329 if (ctx) 330 ntfs_attr_put_search_ctx(ctx); 331 if (m) 332 unmap_mft_record(base_ni); 333 ntfs_debug("Failed. Returning error code %i.", err); 334 return err; 335 } 336 337 /** 338 * ntfs_fault_in_pages_readable - 339 * 340 * Fault a number of userspace pages into pagetables. 341 * 342 * Unlike include/linux/pagemap.h::fault_in_pages_readable(), this one copes 343 * with more than two userspace pages as well as handling the single page case 344 * elegantly. 345 * 346 * If you find this difficult to understand, then think of the while loop being 347 * the following code, except that we do without the integer variable ret: 348 * 349 * do { 350 * ret = __get_user(c, uaddr); 351 * uaddr += PAGE_SIZE; 352 * } while (!ret && uaddr < end); 353 * 354 * Note, the final __get_user() may well run out-of-bounds of the user buffer, 355 * but _not_ out-of-bounds of the page the user buffer belongs to, and since 356 * this is only a read and not a write, and since it is still in the same page, 357 * it should not matter and this makes the code much simpler. 358 */ 359 static inline void ntfs_fault_in_pages_readable(const char __user *uaddr, 360 int bytes) 361 { 362 const char __user *end; 363 volatile char c; 364 365 /* Set @end to the first byte outside the last page we care about. */ 366 end = (const char __user*)PAGE_ALIGN((ptrdiff_t __user)uaddr + bytes); 367 368 while (!__get_user(c, uaddr) && (uaddr += PAGE_SIZE, uaddr < end)) 369 ; 370 } 371 372 /** 373 * ntfs_fault_in_pages_readable_iovec - 374 * 375 * Same as ntfs_fault_in_pages_readable() but operates on an array of iovecs. 376 */ 377 static inline void ntfs_fault_in_pages_readable_iovec(const struct iovec *iov, 378 size_t iov_ofs, int bytes) 379 { 380 do { 381 const char __user *buf; 382 unsigned len; 383 384 buf = iov->iov_base + iov_ofs; 385 len = iov->iov_len - iov_ofs; 386 if (len > bytes) 387 len = bytes; 388 ntfs_fault_in_pages_readable(buf, len); 389 bytes -= len; 390 iov++; 391 iov_ofs = 0; 392 } while (bytes); 393 } 394 395 /** 396 * __ntfs_grab_cache_pages - obtain a number of locked pages 397 * @mapping: address space mapping from which to obtain page cache pages 398 * @index: starting index in @mapping at which to begin obtaining pages 399 * @nr_pages: number of page cache pages to obtain 400 * @pages: array of pages in which to return the obtained page cache pages 401 * @cached_page: allocated but as yet unused page 402 * @lru_pvec: lru-buffering pagevec of caller 403 * 404 * Obtain @nr_pages locked page cache pages from the mapping @maping and 405 * starting at index @index. 406 * 407 * If a page is newly created, increment its refcount and add it to the 408 * caller's lru-buffering pagevec @lru_pvec. 409 * 410 * This is the same as mm/filemap.c::__grab_cache_page(), except that @nr_pages 411 * are obtained at once instead of just one page and that 0 is returned on 412 * success and -errno on error. 413 * 414 * Note, the page locks are obtained in ascending page index order. 415 */ 416 static inline int __ntfs_grab_cache_pages(struct address_space *mapping, 417 pgoff_t index, const unsigned nr_pages, struct page **pages, 418 struct page **cached_page, struct pagevec *lru_pvec) 419 { 420 int err, nr; 421 422 BUG_ON(!nr_pages); 423 err = nr = 0; 424 do { 425 pages[nr] = find_lock_page(mapping, index); 426 if (!pages[nr]) { 427 if (!*cached_page) { 428 *cached_page = page_cache_alloc(mapping); 429 if (unlikely(!*cached_page)) { 430 err = -ENOMEM; 431 goto err_out; 432 } 433 } 434 err = add_to_page_cache(*cached_page, mapping, index, 435 GFP_KERNEL); 436 if (unlikely(err)) { 437 if (err == -EEXIST) 438 continue; 439 goto err_out; 440 } 441 pages[nr] = *cached_page; 442 page_cache_get(*cached_page); 443 if (unlikely(!pagevec_add(lru_pvec, *cached_page))) 444 __pagevec_lru_add(lru_pvec); 445 *cached_page = NULL; 446 } 447 index++; 448 nr++; 449 } while (nr < nr_pages); 450 out: 451 return err; 452 err_out: 453 while (nr > 0) { 454 unlock_page(pages[--nr]); 455 page_cache_release(pages[nr]); 456 } 457 goto out; 458 } 459 460 static inline int ntfs_submit_bh_for_read(struct buffer_head *bh) 461 { 462 lock_buffer(bh); 463 get_bh(bh); 464 bh->b_end_io = end_buffer_read_sync; 465 return submit_bh(READ, bh); 466 } 467 468 /** 469 * ntfs_prepare_pages_for_non_resident_write - prepare pages for receiving data 470 * @pages: array of destination pages 471 * @nr_pages: number of pages in @pages 472 * @pos: byte position in file at which the write begins 473 * @bytes: number of bytes to be written 474 * 475 * This is called for non-resident attributes from ntfs_file_buffered_write() 476 * with i_sem held on the inode (@pages[0]->mapping->host). There are 477 * @nr_pages pages in @pages which are locked but not kmap()ped. The source 478 * data has not yet been copied into the @pages. 479 * 480 * Need to fill any holes with actual clusters, allocate buffers if necessary, 481 * ensure all the buffers are mapped, and bring uptodate any buffers that are 482 * only partially being written to. 483 * 484 * If @nr_pages is greater than one, we are guaranteed that the cluster size is 485 * greater than PAGE_CACHE_SIZE, that all pages in @pages are entirely inside 486 * the same cluster and that they are the entirety of that cluster, and that 487 * the cluster is sparse, i.e. we need to allocate a cluster to fill the hole. 488 * 489 * i_size is not to be modified yet. 490 * 491 * Return 0 on success or -errno on error. 492 */ 493 static int ntfs_prepare_pages_for_non_resident_write(struct page **pages, 494 unsigned nr_pages, s64 pos, size_t bytes) 495 { 496 VCN vcn, highest_vcn = 0, cpos, cend, bh_cpos, bh_cend; 497 LCN lcn; 498 s64 bh_pos, vcn_len, end, initialized_size; 499 sector_t lcn_block; 500 struct page *page; 501 struct inode *vi; 502 ntfs_inode *ni, *base_ni = NULL; 503 ntfs_volume *vol; 504 runlist_element *rl, *rl2; 505 struct buffer_head *bh, *head, *wait[2], **wait_bh = wait; 506 ntfs_attr_search_ctx *ctx = NULL; 507 MFT_RECORD *m = NULL; 508 ATTR_RECORD *a = NULL; 509 unsigned long flags; 510 u32 attr_rec_len = 0; 511 unsigned blocksize, u; 512 int err, mp_size; 513 BOOL rl_write_locked, was_hole, is_retry; 514 unsigned char blocksize_bits; 515 struct { 516 u8 runlist_merged:1; 517 u8 mft_attr_mapped:1; 518 u8 mp_rebuilt:1; 519 u8 attr_switched:1; 520 } status = { 0, 0, 0, 0 }; 521 522 BUG_ON(!nr_pages); 523 BUG_ON(!pages); 524 BUG_ON(!*pages); 525 vi = pages[0]->mapping->host; 526 ni = NTFS_I(vi); 527 vol = ni->vol; 528 ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page " 529 "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.", 530 vi->i_ino, ni->type, pages[0]->index, nr_pages, 531 (long long)pos, bytes); 532 blocksize_bits = vi->i_blkbits; 533 blocksize = 1 << blocksize_bits; 534 u = 0; 535 do { 536 struct page *page = pages[u]; 537 /* 538 * create_empty_buffers() will create uptodate/dirty buffers if 539 * the page is uptodate/dirty. 540 */ 541 if (!page_has_buffers(page)) { 542 create_empty_buffers(page, blocksize, 0); 543 if (unlikely(!page_has_buffers(page))) 544 return -ENOMEM; 545 } 546 } while (++u < nr_pages); 547 rl_write_locked = FALSE; 548 rl = NULL; 549 err = 0; 550 vcn = lcn = -1; 551 vcn_len = 0; 552 lcn_block = -1; 553 was_hole = FALSE; 554 cpos = pos >> vol->cluster_size_bits; 555 end = pos + bytes; 556 cend = (end + vol->cluster_size - 1) >> vol->cluster_size_bits; 557 /* 558 * Loop over each page and for each page over each buffer. Use goto to 559 * reduce indentation. 560 */ 561 u = 0; 562 do_next_page: 563 page = pages[u]; 564 bh_pos = (s64)page->index << PAGE_CACHE_SHIFT; 565 bh = head = page_buffers(page); 566 do { 567 VCN cdelta; 568 s64 bh_end; 569 unsigned bh_cofs; 570 571 /* Clear buffer_new on all buffers to reinitialise state. */ 572 if (buffer_new(bh)) 573 clear_buffer_new(bh); 574 bh_end = bh_pos + blocksize; 575 bh_cpos = bh_pos >> vol->cluster_size_bits; 576 bh_cofs = bh_pos & vol->cluster_size_mask; 577 if (buffer_mapped(bh)) { 578 /* 579 * The buffer is already mapped. If it is uptodate, 580 * ignore it. 581 */ 582 if (buffer_uptodate(bh)) 583 continue; 584 /* 585 * The buffer is not uptodate. If the page is uptodate 586 * set the buffer uptodate and otherwise ignore it. 587 */ 588 if (PageUptodate(page)) { 589 set_buffer_uptodate(bh); 590 continue; 591 } 592 /* 593 * Neither the page nor the buffer are uptodate. If 594 * the buffer is only partially being written to, we 595 * need to read it in before the write, i.e. now. 596 */ 597 if ((bh_pos < pos && bh_end > pos) || 598 (bh_pos < end && bh_end > end)) { 599 /* 600 * If the buffer is fully or partially within 601 * the initialized size, do an actual read. 602 * Otherwise, simply zero the buffer. 603 */ 604 read_lock_irqsave(&ni->size_lock, flags); 605 initialized_size = ni->initialized_size; 606 read_unlock_irqrestore(&ni->size_lock, flags); 607 if (bh_pos < initialized_size) { 608 ntfs_submit_bh_for_read(bh); 609 *wait_bh++ = bh; 610 } else { 611 u8 *kaddr = kmap_atomic(page, KM_USER0); 612 memset(kaddr + bh_offset(bh), 0, 613 blocksize); 614 kunmap_atomic(kaddr, KM_USER0); 615 flush_dcache_page(page); 616 set_buffer_uptodate(bh); 617 } 618 } 619 continue; 620 } 621 /* Unmapped buffer. Need to map it. */ 622 bh->b_bdev = vol->sb->s_bdev; 623 /* 624 * If the current buffer is in the same clusters as the map 625 * cache, there is no need to check the runlist again. The 626 * map cache is made up of @vcn, which is the first cached file 627 * cluster, @vcn_len which is the number of cached file 628 * clusters, @lcn is the device cluster corresponding to @vcn, 629 * and @lcn_block is the block number corresponding to @lcn. 630 */ 631 cdelta = bh_cpos - vcn; 632 if (likely(!cdelta || (cdelta > 0 && cdelta < vcn_len))) { 633 map_buffer_cached: 634 BUG_ON(lcn < 0); 635 bh->b_blocknr = lcn_block + 636 (cdelta << (vol->cluster_size_bits - 637 blocksize_bits)) + 638 (bh_cofs >> blocksize_bits); 639 set_buffer_mapped(bh); 640 /* 641 * If the page is uptodate so is the buffer. If the 642 * buffer is fully outside the write, we ignore it if 643 * it was already allocated and we mark it dirty so it 644 * gets written out if we allocated it. On the other 645 * hand, if we allocated the buffer but we are not 646 * marking it dirty we set buffer_new so we can do 647 * error recovery. 648 */ 649 if (PageUptodate(page)) { 650 if (!buffer_uptodate(bh)) 651 set_buffer_uptodate(bh); 652 if (unlikely(was_hole)) { 653 /* We allocated the buffer. */ 654 unmap_underlying_metadata(bh->b_bdev, 655 bh->b_blocknr); 656 if (bh_end <= pos || bh_pos >= end) 657 mark_buffer_dirty(bh); 658 else 659 set_buffer_new(bh); 660 } 661 continue; 662 } 663 /* Page is _not_ uptodate. */ 664 if (likely(!was_hole)) { 665 /* 666 * Buffer was already allocated. If it is not 667 * uptodate and is only partially being written 668 * to, we need to read it in before the write, 669 * i.e. now. 670 */ 671 if (!buffer_uptodate(bh) && bh_pos < end && 672 bh_end > pos && 673 (bh_pos < pos || 674 bh_end > end)) { 675 /* 676 * If the buffer is fully or partially 677 * within the initialized size, do an 678 * actual read. Otherwise, simply zero 679 * the buffer. 680 */ 681 read_lock_irqsave(&ni->size_lock, 682 flags); 683 initialized_size = ni->initialized_size; 684 read_unlock_irqrestore(&ni->size_lock, 685 flags); 686 if (bh_pos < initialized_size) { 687 ntfs_submit_bh_for_read(bh); 688 *wait_bh++ = bh; 689 } else { 690 u8 *kaddr = kmap_atomic(page, 691 KM_USER0); 692 memset(kaddr + bh_offset(bh), 693 0, blocksize); 694 kunmap_atomic(kaddr, KM_USER0); 695 flush_dcache_page(page); 696 set_buffer_uptodate(bh); 697 } 698 } 699 continue; 700 } 701 /* We allocated the buffer. */ 702 unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); 703 /* 704 * If the buffer is fully outside the write, zero it, 705 * set it uptodate, and mark it dirty so it gets 706 * written out. If it is partially being written to, 707 * zero region surrounding the write but leave it to 708 * commit write to do anything else. Finally, if the 709 * buffer is fully being overwritten, do nothing. 710 */ 711 if (bh_end <= pos || bh_pos >= end) { 712 if (!buffer_uptodate(bh)) { 713 u8 *kaddr = kmap_atomic(page, KM_USER0); 714 memset(kaddr + bh_offset(bh), 0, 715 blocksize); 716 kunmap_atomic(kaddr, KM_USER0); 717 flush_dcache_page(page); 718 set_buffer_uptodate(bh); 719 } 720 mark_buffer_dirty(bh); 721 continue; 722 } 723 set_buffer_new(bh); 724 if (!buffer_uptodate(bh) && 725 (bh_pos < pos || bh_end > end)) { 726 u8 *kaddr; 727 unsigned pofs; 728 729 kaddr = kmap_atomic(page, KM_USER0); 730 if (bh_pos < pos) { 731 pofs = bh_pos & ~PAGE_CACHE_MASK; 732 memset(kaddr + pofs, 0, pos - bh_pos); 733 } 734 if (bh_end > end) { 735 pofs = end & ~PAGE_CACHE_MASK; 736 memset(kaddr + pofs, 0, bh_end - end); 737 } 738 kunmap_atomic(kaddr, KM_USER0); 739 flush_dcache_page(page); 740 } 741 continue; 742 } 743 /* 744 * Slow path: this is the first buffer in the cluster. If it 745 * is outside allocated size and is not uptodate, zero it and 746 * set it uptodate. 747 */ 748 read_lock_irqsave(&ni->size_lock, flags); 749 initialized_size = ni->allocated_size; 750 read_unlock_irqrestore(&ni->size_lock, flags); 751 if (bh_pos > initialized_size) { 752 if (PageUptodate(page)) { 753 if (!buffer_uptodate(bh)) 754 set_buffer_uptodate(bh); 755 } else if (!buffer_uptodate(bh)) { 756 u8 *kaddr = kmap_atomic(page, KM_USER0); 757 memset(kaddr + bh_offset(bh), 0, blocksize); 758 kunmap_atomic(kaddr, KM_USER0); 759 flush_dcache_page(page); 760 set_buffer_uptodate(bh); 761 } 762 continue; 763 } 764 is_retry = FALSE; 765 if (!rl) { 766 down_read(&ni->runlist.lock); 767 retry_remap: 768 rl = ni->runlist.rl; 769 } 770 if (likely(rl != NULL)) { 771 /* Seek to element containing target cluster. */ 772 while (rl->length && rl[1].vcn <= bh_cpos) 773 rl++; 774 lcn = ntfs_rl_vcn_to_lcn(rl, bh_cpos); 775 if (likely(lcn >= 0)) { 776 /* 777 * Successful remap, setup the map cache and 778 * use that to deal with the buffer. 779 */ 780 was_hole = FALSE; 781 vcn = bh_cpos; 782 vcn_len = rl[1].vcn - vcn; 783 lcn_block = lcn << (vol->cluster_size_bits - 784 blocksize_bits); 785 cdelta = 0; 786 /* 787 * If the number of remaining clusters touched 788 * by the write is smaller or equal to the 789 * number of cached clusters, unlock the 790 * runlist as the map cache will be used from 791 * now on. 792 */ 793 if (likely(vcn + vcn_len >= cend)) { 794 if (rl_write_locked) { 795 up_write(&ni->runlist.lock); 796 rl_write_locked = FALSE; 797 } else 798 up_read(&ni->runlist.lock); 799 rl = NULL; 800 } 801 goto map_buffer_cached; 802 } 803 } else 804 lcn = LCN_RL_NOT_MAPPED; 805 /* 806 * If it is not a hole and not out of bounds, the runlist is 807 * probably unmapped so try to map it now. 808 */ 809 if (unlikely(lcn != LCN_HOLE && lcn != LCN_ENOENT)) { 810 if (likely(!is_retry && lcn == LCN_RL_NOT_MAPPED)) { 811 /* Attempt to map runlist. */ 812 if (!rl_write_locked) { 813 /* 814 * We need the runlist locked for 815 * writing, so if it is locked for 816 * reading relock it now and retry in 817 * case it changed whilst we dropped 818 * the lock. 819 */ 820 up_read(&ni->runlist.lock); 821 down_write(&ni->runlist.lock); 822 rl_write_locked = TRUE; 823 goto retry_remap; 824 } 825 err = ntfs_map_runlist_nolock(ni, bh_cpos, 826 NULL); 827 if (likely(!err)) { 828 is_retry = TRUE; 829 goto retry_remap; 830 } 831 /* 832 * If @vcn is out of bounds, pretend @lcn is 833 * LCN_ENOENT. As long as the buffer is out 834 * of bounds this will work fine. 835 */ 836 if (err == -ENOENT) { 837 lcn = LCN_ENOENT; 838 err = 0; 839 goto rl_not_mapped_enoent; 840 } 841 } else 842 err = -EIO; 843 /* Failed to map the buffer, even after retrying. */ 844 bh->b_blocknr = -1; 845 ntfs_error(vol->sb, "Failed to write to inode 0x%lx, " 846 "attribute type 0x%x, vcn 0x%llx, " 847 "vcn offset 0x%x, because its " 848 "location on disk could not be " 849 "determined%s (error code %i).", 850 ni->mft_no, ni->type, 851 (unsigned long long)bh_cpos, 852 (unsigned)bh_pos & 853 vol->cluster_size_mask, 854 is_retry ? " even after retrying" : "", 855 err); 856 break; 857 } 858 rl_not_mapped_enoent: 859 /* 860 * The buffer is in a hole or out of bounds. We need to fill 861 * the hole, unless the buffer is in a cluster which is not 862 * touched by the write, in which case we just leave the buffer 863 * unmapped. This can only happen when the cluster size is 864 * less than the page cache size. 865 */ 866 if (unlikely(vol->cluster_size < PAGE_CACHE_SIZE)) { 867 bh_cend = (bh_end + vol->cluster_size - 1) >> 868 vol->cluster_size_bits; 869 if ((bh_cend <= cpos || bh_cpos >= cend)) { 870 bh->b_blocknr = -1; 871 /* 872 * If the buffer is uptodate we skip it. If it 873 * is not but the page is uptodate, we can set 874 * the buffer uptodate. If the page is not 875 * uptodate, we can clear the buffer and set it 876 * uptodate. Whether this is worthwhile is 877 * debatable and this could be removed. 878 */ 879 if (PageUptodate(page)) { 880 if (!buffer_uptodate(bh)) 881 set_buffer_uptodate(bh); 882 } else if (!buffer_uptodate(bh)) { 883 u8 *kaddr = kmap_atomic(page, KM_USER0); 884 memset(kaddr + bh_offset(bh), 0, 885 blocksize); 886 kunmap_atomic(kaddr, KM_USER0); 887 flush_dcache_page(page); 888 set_buffer_uptodate(bh); 889 } 890 continue; 891 } 892 } 893 /* 894 * Out of bounds buffer is invalid if it was not really out of 895 * bounds. 896 */ 897 BUG_ON(lcn != LCN_HOLE); 898 /* 899 * We need the runlist locked for writing, so if it is locked 900 * for reading relock it now and retry in case it changed 901 * whilst we dropped the lock. 902 */ 903 BUG_ON(!rl); 904 if (!rl_write_locked) { 905 up_read(&ni->runlist.lock); 906 down_write(&ni->runlist.lock); 907 rl_write_locked = TRUE; 908 goto retry_remap; 909 } 910 /* Find the previous last allocated cluster. */ 911 BUG_ON(rl->lcn != LCN_HOLE); 912 lcn = -1; 913 rl2 = rl; 914 while (--rl2 >= ni->runlist.rl) { 915 if (rl2->lcn >= 0) { 916 lcn = rl2->lcn + rl2->length; 917 break; 918 } 919 } 920 rl2 = ntfs_cluster_alloc(vol, bh_cpos, 1, lcn, DATA_ZONE, 921 FALSE); 922 if (IS_ERR(rl2)) { 923 err = PTR_ERR(rl2); 924 ntfs_debug("Failed to allocate cluster, error code %i.", 925 err); 926 break; 927 } 928 lcn = rl2->lcn; 929 rl = ntfs_runlists_merge(ni->runlist.rl, rl2); 930 if (IS_ERR(rl)) { 931 err = PTR_ERR(rl); 932 if (err != -ENOMEM) 933 err = -EIO; 934 if (ntfs_cluster_free_from_rl(vol, rl2)) { 935 ntfs_error(vol->sb, "Failed to release " 936 "allocated cluster in error " 937 "code path. Run chkdsk to " 938 "recover the lost cluster."); 939 NVolSetErrors(vol); 940 } 941 ntfs_free(rl2); 942 break; 943 } 944 ni->runlist.rl = rl; 945 status.runlist_merged = 1; 946 ntfs_debug("Allocated cluster, lcn 0x%llx.", lcn); 947 /* Map and lock the mft record and get the attribute record. */ 948 if (!NInoAttr(ni)) 949 base_ni = ni; 950 else 951 base_ni = ni->ext.base_ntfs_ino; 952 m = map_mft_record(base_ni); 953 if (IS_ERR(m)) { 954 err = PTR_ERR(m); 955 break; 956 } 957 ctx = ntfs_attr_get_search_ctx(base_ni, m); 958 if (unlikely(!ctx)) { 959 err = -ENOMEM; 960 unmap_mft_record(base_ni); 961 break; 962 } 963 status.mft_attr_mapped = 1; 964 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, 965 CASE_SENSITIVE, bh_cpos, NULL, 0, ctx); 966 if (unlikely(err)) { 967 if (err == -ENOENT) 968 err = -EIO; 969 break; 970 } 971 m = ctx->mrec; 972 a = ctx->attr; 973 /* 974 * Find the runlist element with which the attribute extent 975 * starts. Note, we cannot use the _attr_ version because we 976 * have mapped the mft record. That is ok because we know the 977 * runlist fragment must be mapped already to have ever gotten 978 * here, so we can just use the _rl_ version. 979 */ 980 vcn = sle64_to_cpu(a->data.non_resident.lowest_vcn); 981 rl2 = ntfs_rl_find_vcn_nolock(rl, vcn); 982 BUG_ON(!rl2); 983 BUG_ON(!rl2->length); 984 BUG_ON(rl2->lcn < LCN_HOLE); 985 highest_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn); 986 /* 987 * If @highest_vcn is zero, calculate the real highest_vcn 988 * (which can really be zero). 989 */ 990 if (!highest_vcn) 991 highest_vcn = (sle64_to_cpu( 992 a->data.non_resident.allocated_size) >> 993 vol->cluster_size_bits) - 1; 994 /* 995 * Determine the size of the mapping pairs array for the new 996 * extent, i.e. the old extent with the hole filled. 997 */ 998 mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, vcn, 999 highest_vcn); 1000 if (unlikely(mp_size <= 0)) { 1001 if (!(err = mp_size)) 1002 err = -EIO; 1003 ntfs_debug("Failed to get size for mapping pairs " 1004 "array, error code %i.", err); 1005 break; 1006 } 1007 /* 1008 * Resize the attribute record to fit the new mapping pairs 1009 * array. 1010 */ 1011 attr_rec_len = le32_to_cpu(a->length); 1012 err = ntfs_attr_record_resize(m, a, mp_size + le16_to_cpu( 1013 a->data.non_resident.mapping_pairs_offset)); 1014 if (unlikely(err)) { 1015 BUG_ON(err != -ENOSPC); 1016 // TODO: Deal with this by using the current attribute 1017 // and fill it with as much of the mapping pairs 1018 // array as possible. Then loop over each attribute 1019 // extent rewriting the mapping pairs arrays as we go 1020 // along and if when we reach the end we have not 1021 // enough space, try to resize the last attribute 1022 // extent and if even that fails, add a new attribute 1023 // extent. 1024 // We could also try to resize at each step in the hope 1025 // that we will not need to rewrite every single extent. 1026 // Note, we may need to decompress some extents to fill 1027 // the runlist as we are walking the extents... 1028 ntfs_error(vol->sb, "Not enough space in the mft " 1029 "record for the extended attribute " 1030 "record. This case is not " 1031 "implemented yet."); 1032 err = -EOPNOTSUPP; 1033 break ; 1034 } 1035 status.mp_rebuilt = 1; 1036 /* 1037 * Generate the mapping pairs array directly into the attribute 1038 * record. 1039 */ 1040 err = ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu( 1041 a->data.non_resident.mapping_pairs_offset), 1042 mp_size, rl2, vcn, highest_vcn, NULL); 1043 if (unlikely(err)) { 1044 ntfs_error(vol->sb, "Cannot fill hole in inode 0x%lx, " 1045 "attribute type 0x%x, because building " 1046 "the mapping pairs failed with error " 1047 "code %i.", vi->i_ino, 1048 (unsigned)le32_to_cpu(ni->type), err); 1049 err = -EIO; 1050 break; 1051 } 1052 /* Update the highest_vcn but only if it was not set. */ 1053 if (unlikely(!a->data.non_resident.highest_vcn)) 1054 a->data.non_resident.highest_vcn = 1055 cpu_to_sle64(highest_vcn); 1056 /* 1057 * If the attribute is sparse/compressed, update the compressed 1058 * size in the ntfs_inode structure and the attribute record. 1059 */ 1060 if (likely(NInoSparse(ni) || NInoCompressed(ni))) { 1061 /* 1062 * If we are not in the first attribute extent, switch 1063 * to it, but first ensure the changes will make it to 1064 * disk later. 1065 */ 1066 if (a->data.non_resident.lowest_vcn) { 1067 flush_dcache_mft_record_page(ctx->ntfs_ino); 1068 mark_mft_record_dirty(ctx->ntfs_ino); 1069 ntfs_attr_reinit_search_ctx(ctx); 1070 err = ntfs_attr_lookup(ni->type, ni->name, 1071 ni->name_len, CASE_SENSITIVE, 1072 0, NULL, 0, ctx); 1073 if (unlikely(err)) { 1074 status.attr_switched = 1; 1075 break; 1076 } 1077 /* @m is not used any more so do not set it. */ 1078 a = ctx->attr; 1079 } 1080 write_lock_irqsave(&ni->size_lock, flags); 1081 ni->itype.compressed.size += vol->cluster_size; 1082 a->data.non_resident.compressed_size = 1083 cpu_to_sle64(ni->itype.compressed.size); 1084 write_unlock_irqrestore(&ni->size_lock, flags); 1085 } 1086 /* Ensure the changes make it to disk. */ 1087 flush_dcache_mft_record_page(ctx->ntfs_ino); 1088 mark_mft_record_dirty(ctx->ntfs_ino); 1089 ntfs_attr_put_search_ctx(ctx); 1090 unmap_mft_record(base_ni); 1091 /* Successfully filled the hole. */ 1092 status.runlist_merged = 0; 1093 status.mft_attr_mapped = 0; 1094 status.mp_rebuilt = 0; 1095 /* Setup the map cache and use that to deal with the buffer. */ 1096 was_hole = TRUE; 1097 vcn = bh_cpos; 1098 vcn_len = 1; 1099 lcn_block = lcn << (vol->cluster_size_bits - blocksize_bits); 1100 cdelta = 0; 1101 /* 1102 * If the number of remaining clusters in the @pages is smaller 1103 * or equal to the number of cached clusters, unlock the 1104 * runlist as the map cache will be used from now on. 1105 */ 1106 if (likely(vcn + vcn_len >= cend)) { 1107 up_write(&ni->runlist.lock); 1108 rl_write_locked = FALSE; 1109 rl = NULL; 1110 } 1111 goto map_buffer_cached; 1112 } while (bh_pos += blocksize, (bh = bh->b_this_page) != head); 1113 /* If there are no errors, do the next page. */ 1114 if (likely(!err && ++u < nr_pages)) 1115 goto do_next_page; 1116 /* If there are no errors, release the runlist lock if we took it. */ 1117 if (likely(!err)) { 1118 if (unlikely(rl_write_locked)) { 1119 up_write(&ni->runlist.lock); 1120 rl_write_locked = FALSE; 1121 } else if (unlikely(rl)) 1122 up_read(&ni->runlist.lock); 1123 rl = NULL; 1124 } 1125 /* If we issued read requests, let them complete. */ 1126 read_lock_irqsave(&ni->size_lock, flags); 1127 initialized_size = ni->initialized_size; 1128 read_unlock_irqrestore(&ni->size_lock, flags); 1129 while (wait_bh > wait) { 1130 bh = *--wait_bh; 1131 wait_on_buffer(bh); 1132 if (likely(buffer_uptodate(bh))) { 1133 page = bh->b_page; 1134 bh_pos = ((s64)page->index << PAGE_CACHE_SHIFT) + 1135 bh_offset(bh); 1136 /* 1137 * If the buffer overflows the initialized size, need 1138 * to zero the overflowing region. 1139 */ 1140 if (unlikely(bh_pos + blocksize > initialized_size)) { 1141 u8 *kaddr; 1142 int ofs = 0; 1143 1144 if (likely(bh_pos < initialized_size)) 1145 ofs = initialized_size - bh_pos; 1146 kaddr = kmap_atomic(page, KM_USER0); 1147 memset(kaddr + bh_offset(bh) + ofs, 0, 1148 blocksize - ofs); 1149 kunmap_atomic(kaddr, KM_USER0); 1150 flush_dcache_page(page); 1151 } 1152 } else /* if (unlikely(!buffer_uptodate(bh))) */ 1153 err = -EIO; 1154 } 1155 if (likely(!err)) { 1156 /* Clear buffer_new on all buffers. */ 1157 u = 0; 1158 do { 1159 bh = head = page_buffers(pages[u]); 1160 do { 1161 if (buffer_new(bh)) 1162 clear_buffer_new(bh); 1163 } while ((bh = bh->b_this_page) != head); 1164 } while (++u < nr_pages); 1165 ntfs_debug("Done."); 1166 return err; 1167 } 1168 if (status.attr_switched) { 1169 /* Get back to the attribute extent we modified. */ 1170 ntfs_attr_reinit_search_ctx(ctx); 1171 if (ntfs_attr_lookup(ni->type, ni->name, ni->name_len, 1172 CASE_SENSITIVE, bh_cpos, NULL, 0, ctx)) { 1173 ntfs_error(vol->sb, "Failed to find required " 1174 "attribute extent of attribute in " 1175 "error code path. Run chkdsk to " 1176 "recover."); 1177 write_lock_irqsave(&ni->size_lock, flags); 1178 ni->itype.compressed.size += vol->cluster_size; 1179 write_unlock_irqrestore(&ni->size_lock, flags); 1180 flush_dcache_mft_record_page(ctx->ntfs_ino); 1181 mark_mft_record_dirty(ctx->ntfs_ino); 1182 /* 1183 * The only thing that is now wrong is the compressed 1184 * size of the base attribute extent which chkdsk 1185 * should be able to fix. 1186 */ 1187 NVolSetErrors(vol); 1188 } else { 1189 m = ctx->mrec; 1190 a = ctx->attr; 1191 status.attr_switched = 0; 1192 } 1193 } 1194 /* 1195 * If the runlist has been modified, need to restore it by punching a 1196 * hole into it and we then need to deallocate the on-disk cluster as 1197 * well. Note, we only modify the runlist if we are able to generate a 1198 * new mapping pairs array, i.e. only when the mapped attribute extent 1199 * is not switched. 1200 */ 1201 if (status.runlist_merged && !status.attr_switched) { 1202 BUG_ON(!rl_write_locked); 1203 /* Make the file cluster we allocated sparse in the runlist. */ 1204 if (ntfs_rl_punch_nolock(vol, &ni->runlist, bh_cpos, 1)) { 1205 ntfs_error(vol->sb, "Failed to punch hole into " 1206 "attribute runlist in error code " 1207 "path. Run chkdsk to recover the " 1208 "lost cluster."); 1209 make_bad_inode(vi); 1210 make_bad_inode(VFS_I(base_ni)); 1211 NVolSetErrors(vol); 1212 } else /* if (success) */ { 1213 status.runlist_merged = 0; 1214 /* 1215 * Deallocate the on-disk cluster we allocated but only 1216 * if we succeeded in punching its vcn out of the 1217 * runlist. 1218 */ 1219 down_write(&vol->lcnbmp_lock); 1220 if (ntfs_bitmap_clear_bit(vol->lcnbmp_ino, lcn)) { 1221 ntfs_error(vol->sb, "Failed to release " 1222 "allocated cluster in error " 1223 "code path. Run chkdsk to " 1224 "recover the lost cluster."); 1225 NVolSetErrors(vol); 1226 } 1227 up_write(&vol->lcnbmp_lock); 1228 } 1229 } 1230 /* 1231 * Resize the attribute record to its old size and rebuild the mapping 1232 * pairs array. Note, we only can do this if the runlist has been 1233 * restored to its old state which also implies that the mapped 1234 * attribute extent is not switched. 1235 */ 1236 if (status.mp_rebuilt && !status.runlist_merged) { 1237 if (ntfs_attr_record_resize(m, a, attr_rec_len)) { 1238 ntfs_error(vol->sb, "Failed to restore attribute " 1239 "record in error code path. Run " 1240 "chkdsk to recover."); 1241 make_bad_inode(vi); 1242 make_bad_inode(VFS_I(base_ni)); 1243 NVolSetErrors(vol); 1244 } else /* if (success) */ { 1245 if (ntfs_mapping_pairs_build(vol, (u8*)a + 1246 le16_to_cpu(a->data.non_resident. 1247 mapping_pairs_offset), attr_rec_len - 1248 le16_to_cpu(a->data.non_resident. 1249 mapping_pairs_offset), ni->runlist.rl, 1250 vcn, highest_vcn, NULL)) { 1251 ntfs_error(vol->sb, "Failed to restore " 1252 "mapping pairs array in error " 1253 "code path. Run chkdsk to " 1254 "recover."); 1255 make_bad_inode(vi); 1256 make_bad_inode(VFS_I(base_ni)); 1257 NVolSetErrors(vol); 1258 } 1259 flush_dcache_mft_record_page(ctx->ntfs_ino); 1260 mark_mft_record_dirty(ctx->ntfs_ino); 1261 } 1262 } 1263 /* Release the mft record and the attribute. */ 1264 if (status.mft_attr_mapped) { 1265 ntfs_attr_put_search_ctx(ctx); 1266 unmap_mft_record(base_ni); 1267 } 1268 /* Release the runlist lock. */ 1269 if (rl_write_locked) 1270 up_write(&ni->runlist.lock); 1271 else if (rl) 1272 up_read(&ni->runlist.lock); 1273 /* 1274 * Zero out any newly allocated blocks to avoid exposing stale data. 1275 * If BH_New is set, we know that the block was newly allocated above 1276 * and that it has not been fully zeroed and marked dirty yet. 1277 */ 1278 nr_pages = u; 1279 u = 0; 1280 end = bh_cpos << vol->cluster_size_bits; 1281 do { 1282 page = pages[u]; 1283 bh = head = page_buffers(page); 1284 do { 1285 if (u == nr_pages && 1286 ((s64)page->index << PAGE_CACHE_SHIFT) + 1287 bh_offset(bh) >= end) 1288 break; 1289 if (!buffer_new(bh)) 1290 continue; 1291 clear_buffer_new(bh); 1292 if (!buffer_uptodate(bh)) { 1293 if (PageUptodate(page)) 1294 set_buffer_uptodate(bh); 1295 else { 1296 u8 *kaddr = kmap_atomic(page, KM_USER0); 1297 memset(kaddr + bh_offset(bh), 0, 1298 blocksize); 1299 kunmap_atomic(kaddr, KM_USER0); 1300 flush_dcache_page(page); 1301 set_buffer_uptodate(bh); 1302 } 1303 } 1304 mark_buffer_dirty(bh); 1305 } while ((bh = bh->b_this_page) != head); 1306 } while (++u <= nr_pages); 1307 ntfs_error(vol->sb, "Failed. Returning error code %i.", err); 1308 return err; 1309 } 1310 1311 /* 1312 * Copy as much as we can into the pages and return the number of bytes which 1313 * were sucessfully copied. If a fault is encountered then clear the pages 1314 * out to (ofs + bytes) and return the number of bytes which were copied. 1315 */ 1316 static inline size_t ntfs_copy_from_user(struct page **pages, 1317 unsigned nr_pages, unsigned ofs, const char __user *buf, 1318 size_t bytes) 1319 { 1320 struct page **last_page = pages + nr_pages; 1321 char *kaddr; 1322 size_t total = 0; 1323 unsigned len; 1324 int left; 1325 1326 do { 1327 len = PAGE_CACHE_SIZE - ofs; 1328 if (len > bytes) 1329 len = bytes; 1330 kaddr = kmap_atomic(*pages, KM_USER0); 1331 left = __copy_from_user_inatomic(kaddr + ofs, buf, len); 1332 kunmap_atomic(kaddr, KM_USER0); 1333 if (unlikely(left)) { 1334 /* Do it the slow way. */ 1335 kaddr = kmap(*pages); 1336 left = __copy_from_user(kaddr + ofs, buf, len); 1337 kunmap(*pages); 1338 if (unlikely(left)) 1339 goto err_out; 1340 } 1341 total += len; 1342 bytes -= len; 1343 if (!bytes) 1344 break; 1345 buf += len; 1346 ofs = 0; 1347 } while (++pages < last_page); 1348 out: 1349 return total; 1350 err_out: 1351 total += len - left; 1352 /* Zero the rest of the target like __copy_from_user(). */ 1353 while (++pages < last_page) { 1354 bytes -= len; 1355 if (!bytes) 1356 break; 1357 len = PAGE_CACHE_SIZE; 1358 if (len > bytes) 1359 len = bytes; 1360 kaddr = kmap_atomic(*pages, KM_USER0); 1361 memset(kaddr, 0, len); 1362 kunmap_atomic(kaddr, KM_USER0); 1363 } 1364 goto out; 1365 } 1366 1367 static size_t __ntfs_copy_from_user_iovec(char *vaddr, 1368 const struct iovec *iov, size_t iov_ofs, size_t bytes) 1369 { 1370 size_t total = 0; 1371 1372 while (1) { 1373 const char __user *buf = iov->iov_base + iov_ofs; 1374 unsigned len; 1375 size_t left; 1376 1377 len = iov->iov_len - iov_ofs; 1378 if (len > bytes) 1379 len = bytes; 1380 left = __copy_from_user_inatomic(vaddr, buf, len); 1381 total += len; 1382 bytes -= len; 1383 vaddr += len; 1384 if (unlikely(left)) { 1385 /* 1386 * Zero the rest of the target like __copy_from_user(). 1387 */ 1388 memset(vaddr, 0, bytes); 1389 total -= left; 1390 break; 1391 } 1392 if (!bytes) 1393 break; 1394 iov++; 1395 iov_ofs = 0; 1396 } 1397 return total; 1398 } 1399 1400 static inline void ntfs_set_next_iovec(const struct iovec **iovp, 1401 size_t *iov_ofsp, size_t bytes) 1402 { 1403 const struct iovec *iov = *iovp; 1404 size_t iov_ofs = *iov_ofsp; 1405 1406 while (bytes) { 1407 unsigned len; 1408 1409 len = iov->iov_len - iov_ofs; 1410 if (len > bytes) 1411 len = bytes; 1412 bytes -= len; 1413 iov_ofs += len; 1414 if (iov->iov_len == iov_ofs) { 1415 iov++; 1416 iov_ofs = 0; 1417 } 1418 } 1419 *iovp = iov; 1420 *iov_ofsp = iov_ofs; 1421 } 1422 1423 /* 1424 * This has the same side-effects and return value as ntfs_copy_from_user(). 1425 * The difference is that on a fault we need to memset the remainder of the 1426 * pages (out to offset + bytes), to emulate ntfs_copy_from_user()'s 1427 * single-segment behaviour. 1428 * 1429 * We call the same helper (__ntfs_copy_from_user_iovec()) both when atomic and 1430 * when not atomic. This is ok because __ntfs_copy_from_user_iovec() calls 1431 * __copy_from_user_inatomic() and it is ok to call this when non-atomic. In 1432 * fact, the only difference between __copy_from_user_inatomic() and 1433 * __copy_from_user() is that the latter calls might_sleep(). And on many 1434 * architectures __copy_from_user_inatomic() is just defined to 1435 * __copy_from_user() so it makes no difference at all on those architectures. 1436 */ 1437 static inline size_t ntfs_copy_from_user_iovec(struct page **pages, 1438 unsigned nr_pages, unsigned ofs, const struct iovec **iov, 1439 size_t *iov_ofs, size_t bytes) 1440 { 1441 struct page **last_page = pages + nr_pages; 1442 char *kaddr; 1443 size_t copied, len, total = 0; 1444 1445 do { 1446 len = PAGE_CACHE_SIZE - ofs; 1447 if (len > bytes) 1448 len = bytes; 1449 kaddr = kmap_atomic(*pages, KM_USER0); 1450 copied = __ntfs_copy_from_user_iovec(kaddr + ofs, 1451 *iov, *iov_ofs, len); 1452 kunmap_atomic(kaddr, KM_USER0); 1453 if (unlikely(copied != len)) { 1454 /* Do it the slow way. */ 1455 kaddr = kmap(*pages); 1456 copied = __ntfs_copy_from_user_iovec(kaddr + ofs, 1457 *iov, *iov_ofs, len); 1458 kunmap(*pages); 1459 if (unlikely(copied != len)) 1460 goto err_out; 1461 } 1462 total += len; 1463 bytes -= len; 1464 if (!bytes) 1465 break; 1466 ntfs_set_next_iovec(iov, iov_ofs, len); 1467 ofs = 0; 1468 } while (++pages < last_page); 1469 out: 1470 return total; 1471 err_out: 1472 total += copied; 1473 /* Zero the rest of the target like __copy_from_user(). */ 1474 while (++pages < last_page) { 1475 bytes -= len; 1476 if (!bytes) 1477 break; 1478 len = PAGE_CACHE_SIZE; 1479 if (len > bytes) 1480 len = bytes; 1481 kaddr = kmap_atomic(*pages, KM_USER0); 1482 memset(kaddr, 0, len); 1483 kunmap_atomic(kaddr, KM_USER0); 1484 } 1485 goto out; 1486 } 1487 1488 static inline void ntfs_flush_dcache_pages(struct page **pages, 1489 unsigned nr_pages) 1490 { 1491 BUG_ON(!nr_pages); 1492 do { 1493 /* 1494 * Warning: Do not do the decrement at the same time as the 1495 * call because flush_dcache_page() is a NULL macro on i386 1496 * and hence the decrement never happens. 1497 */ 1498 flush_dcache_page(pages[nr_pages]); 1499 } while (--nr_pages > 0); 1500 } 1501 1502 /** 1503 * ntfs_commit_pages_after_non_resident_write - commit the received data 1504 * @pages: array of destination pages 1505 * @nr_pages: number of pages in @pages 1506 * @pos: byte position in file at which the write begins 1507 * @bytes: number of bytes to be written 1508 * 1509 * See description of ntfs_commit_pages_after_write(), below. 1510 */ 1511 static inline int ntfs_commit_pages_after_non_resident_write( 1512 struct page **pages, const unsigned nr_pages, 1513 s64 pos, size_t bytes) 1514 { 1515 s64 end, initialized_size; 1516 struct inode *vi; 1517 ntfs_inode *ni, *base_ni; 1518 struct buffer_head *bh, *head; 1519 ntfs_attr_search_ctx *ctx; 1520 MFT_RECORD *m; 1521 ATTR_RECORD *a; 1522 unsigned long flags; 1523 unsigned blocksize, u; 1524 int err; 1525 1526 vi = pages[0]->mapping->host; 1527 ni = NTFS_I(vi); 1528 blocksize = 1 << vi->i_blkbits; 1529 end = pos + bytes; 1530 u = 0; 1531 do { 1532 s64 bh_pos; 1533 struct page *page; 1534 BOOL partial; 1535 1536 page = pages[u]; 1537 bh_pos = (s64)page->index << PAGE_CACHE_SHIFT; 1538 bh = head = page_buffers(page); 1539 partial = FALSE; 1540 do { 1541 s64 bh_end; 1542 1543 bh_end = bh_pos + blocksize; 1544 if (bh_end <= pos || bh_pos >= end) { 1545 if (!buffer_uptodate(bh)) 1546 partial = TRUE; 1547 } else { 1548 set_buffer_uptodate(bh); 1549 mark_buffer_dirty(bh); 1550 } 1551 } while (bh_pos += blocksize, (bh = bh->b_this_page) != head); 1552 /* 1553 * If all buffers are now uptodate but the page is not, set the 1554 * page uptodate. 1555 */ 1556 if (!partial && !PageUptodate(page)) 1557 SetPageUptodate(page); 1558 } while (++u < nr_pages); 1559 /* 1560 * Finally, if we do not need to update initialized_size or i_size we 1561 * are finished. 1562 */ 1563 read_lock_irqsave(&ni->size_lock, flags); 1564 initialized_size = ni->initialized_size; 1565 read_unlock_irqrestore(&ni->size_lock, flags); 1566 if (end <= initialized_size) { 1567 ntfs_debug("Done."); 1568 return 0; 1569 } 1570 /* 1571 * Update initialized_size/i_size as appropriate, both in the inode and 1572 * the mft record. 1573 */ 1574 if (!NInoAttr(ni)) 1575 base_ni = ni; 1576 else 1577 base_ni = ni->ext.base_ntfs_ino; 1578 /* Map, pin, and lock the mft record. */ 1579 m = map_mft_record(base_ni); 1580 if (IS_ERR(m)) { 1581 err = PTR_ERR(m); 1582 m = NULL; 1583 ctx = NULL; 1584 goto err_out; 1585 } 1586 BUG_ON(!NInoNonResident(ni)); 1587 ctx = ntfs_attr_get_search_ctx(base_ni, m); 1588 if (unlikely(!ctx)) { 1589 err = -ENOMEM; 1590 goto err_out; 1591 } 1592 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, 1593 CASE_SENSITIVE, 0, NULL, 0, ctx); 1594 if (unlikely(err)) { 1595 if (err == -ENOENT) 1596 err = -EIO; 1597 goto err_out; 1598 } 1599 a = ctx->attr; 1600 BUG_ON(!a->non_resident); 1601 write_lock_irqsave(&ni->size_lock, flags); 1602 BUG_ON(end > ni->allocated_size); 1603 ni->initialized_size = end; 1604 a->data.non_resident.initialized_size = cpu_to_sle64(end); 1605 if (end > i_size_read(vi)) { 1606 i_size_write(vi, end); 1607 a->data.non_resident.data_size = 1608 a->data.non_resident.initialized_size; 1609 } 1610 write_unlock_irqrestore(&ni->size_lock, flags); 1611 /* Mark the mft record dirty, so it gets written back. */ 1612 flush_dcache_mft_record_page(ctx->ntfs_ino); 1613 mark_mft_record_dirty(ctx->ntfs_ino); 1614 ntfs_attr_put_search_ctx(ctx); 1615 unmap_mft_record(base_ni); 1616 ntfs_debug("Done."); 1617 return 0; 1618 err_out: 1619 if (ctx) 1620 ntfs_attr_put_search_ctx(ctx); 1621 if (m) 1622 unmap_mft_record(base_ni); 1623 ntfs_error(vi->i_sb, "Failed to update initialized_size/i_size (error " 1624 "code %i).", err); 1625 if (err != -ENOMEM) { 1626 NVolSetErrors(ni->vol); 1627 make_bad_inode(VFS_I(base_ni)); 1628 make_bad_inode(vi); 1629 } 1630 return err; 1631 } 1632 1633 /** 1634 * ntfs_commit_pages_after_write - commit the received data 1635 * @pages: array of destination pages 1636 * @nr_pages: number of pages in @pages 1637 * @pos: byte position in file at which the write begins 1638 * @bytes: number of bytes to be written 1639 * 1640 * This is called from ntfs_file_buffered_write() with i_sem held on the inode 1641 * (@pages[0]->mapping->host). There are @nr_pages pages in @pages which are 1642 * locked but not kmap()ped. The source data has already been copied into the 1643 * @page. ntfs_prepare_pages_for_non_resident_write() has been called before 1644 * the data was copied (for non-resident attributes only) and it returned 1645 * success. 1646 * 1647 * Need to set uptodate and mark dirty all buffers within the boundary of the 1648 * write. If all buffers in a page are uptodate we set the page uptodate, too. 1649 * 1650 * Setting the buffers dirty ensures that they get written out later when 1651 * ntfs_writepage() is invoked by the VM. 1652 * 1653 * Finally, we need to update i_size and initialized_size as appropriate both 1654 * in the inode and the mft record. 1655 * 1656 * This is modelled after fs/buffer.c::generic_commit_write(), which marks 1657 * buffers uptodate and dirty, sets the page uptodate if all buffers in the 1658 * page are uptodate, and updates i_size if the end of io is beyond i_size. In 1659 * that case, it also marks the inode dirty. 1660 * 1661 * If things have gone as outlined in 1662 * ntfs_prepare_pages_for_non_resident_write(), we do not need to do any page 1663 * content modifications here for non-resident attributes. For resident 1664 * attributes we need to do the uptodate bringing here which we combine with 1665 * the copying into the mft record which means we save one atomic kmap. 1666 * 1667 * Return 0 on success or -errno on error. 1668 */ 1669 static int ntfs_commit_pages_after_write(struct page **pages, 1670 const unsigned nr_pages, s64 pos, size_t bytes) 1671 { 1672 s64 end, initialized_size; 1673 loff_t i_size; 1674 struct inode *vi; 1675 ntfs_inode *ni, *base_ni; 1676 struct page *page; 1677 ntfs_attr_search_ctx *ctx; 1678 MFT_RECORD *m; 1679 ATTR_RECORD *a; 1680 char *kattr, *kaddr; 1681 unsigned long flags; 1682 u32 attr_len; 1683 int err; 1684 1685 BUG_ON(!nr_pages); 1686 BUG_ON(!pages); 1687 page = pages[0]; 1688 BUG_ON(!page); 1689 vi = page->mapping->host; 1690 ni = NTFS_I(vi); 1691 ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page " 1692 "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.", 1693 vi->i_ino, ni->type, page->index, nr_pages, 1694 (long long)pos, bytes); 1695 if (NInoNonResident(ni)) 1696 return ntfs_commit_pages_after_non_resident_write(pages, 1697 nr_pages, pos, bytes); 1698 BUG_ON(nr_pages > 1); 1699 /* 1700 * Attribute is resident, implying it is not compressed, encrypted, or 1701 * sparse. 1702 */ 1703 if (!NInoAttr(ni)) 1704 base_ni = ni; 1705 else 1706 base_ni = ni->ext.base_ntfs_ino; 1707 BUG_ON(NInoNonResident(ni)); 1708 /* Map, pin, and lock the mft record. */ 1709 m = map_mft_record(base_ni); 1710 if (IS_ERR(m)) { 1711 err = PTR_ERR(m); 1712 m = NULL; 1713 ctx = NULL; 1714 goto err_out; 1715 } 1716 ctx = ntfs_attr_get_search_ctx(base_ni, m); 1717 if (unlikely(!ctx)) { 1718 err = -ENOMEM; 1719 goto err_out; 1720 } 1721 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, 1722 CASE_SENSITIVE, 0, NULL, 0, ctx); 1723 if (unlikely(err)) { 1724 if (err == -ENOENT) 1725 err = -EIO; 1726 goto err_out; 1727 } 1728 a = ctx->attr; 1729 BUG_ON(a->non_resident); 1730 /* The total length of the attribute value. */ 1731 attr_len = le32_to_cpu(a->data.resident.value_length); 1732 i_size = i_size_read(vi); 1733 BUG_ON(attr_len != i_size); 1734 BUG_ON(pos > attr_len); 1735 end = pos + bytes; 1736 BUG_ON(end > le32_to_cpu(a->length) - 1737 le16_to_cpu(a->data.resident.value_offset)); 1738 kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset); 1739 kaddr = kmap_atomic(page, KM_USER0); 1740 /* Copy the received data from the page to the mft record. */ 1741 memcpy(kattr + pos, kaddr + pos, bytes); 1742 /* Update the attribute length if necessary. */ 1743 if (end > attr_len) { 1744 attr_len = end; 1745 a->data.resident.value_length = cpu_to_le32(attr_len); 1746 } 1747 /* 1748 * If the page is not uptodate, bring the out of bounds area(s) 1749 * uptodate by copying data from the mft record to the page. 1750 */ 1751 if (!PageUptodate(page)) { 1752 if (pos > 0) 1753 memcpy(kaddr, kattr, pos); 1754 if (end < attr_len) 1755 memcpy(kaddr + end, kattr + end, attr_len - end); 1756 /* Zero the region outside the end of the attribute value. */ 1757 memset(kaddr + attr_len, 0, PAGE_CACHE_SIZE - attr_len); 1758 flush_dcache_page(page); 1759 SetPageUptodate(page); 1760 } 1761 kunmap_atomic(kaddr, KM_USER0); 1762 /* Update initialized_size/i_size if necessary. */ 1763 read_lock_irqsave(&ni->size_lock, flags); 1764 initialized_size = ni->initialized_size; 1765 BUG_ON(end > ni->allocated_size); 1766 read_unlock_irqrestore(&ni->size_lock, flags); 1767 BUG_ON(initialized_size != i_size); 1768 if (end > initialized_size) { 1769 unsigned long flags; 1770 1771 write_lock_irqsave(&ni->size_lock, flags); 1772 ni->initialized_size = end; 1773 i_size_write(vi, end); 1774 write_unlock_irqrestore(&ni->size_lock, flags); 1775 } 1776 /* Mark the mft record dirty, so it gets written back. */ 1777 flush_dcache_mft_record_page(ctx->ntfs_ino); 1778 mark_mft_record_dirty(ctx->ntfs_ino); 1779 ntfs_attr_put_search_ctx(ctx); 1780 unmap_mft_record(base_ni); 1781 ntfs_debug("Done."); 1782 return 0; 1783 err_out: 1784 if (err == -ENOMEM) { 1785 ntfs_warning(vi->i_sb, "Error allocating memory required to " 1786 "commit the write."); 1787 if (PageUptodate(page)) { 1788 ntfs_warning(vi->i_sb, "Page is uptodate, setting " 1789 "dirty so the write will be retried " 1790 "later on by the VM."); 1791 /* 1792 * Put the page on mapping->dirty_pages, but leave its 1793 * buffers' dirty state as-is. 1794 */ 1795 __set_page_dirty_nobuffers(page); 1796 err = 0; 1797 } else 1798 ntfs_error(vi->i_sb, "Page is not uptodate. Written " 1799 "data has been lost."); 1800 } else { 1801 ntfs_error(vi->i_sb, "Resident attribute commit write failed " 1802 "with error %i.", err); 1803 NVolSetErrors(ni->vol); 1804 make_bad_inode(VFS_I(base_ni)); 1805 make_bad_inode(vi); 1806 } 1807 if (ctx) 1808 ntfs_attr_put_search_ctx(ctx); 1809 if (m) 1810 unmap_mft_record(base_ni); 1811 return err; 1812 } 1813 1814 /** 1815 * ntfs_file_buffered_write - 1816 * 1817 * Locking: The vfs is holding ->i_sem on the inode. 1818 */ 1819 static ssize_t ntfs_file_buffered_write(struct kiocb *iocb, 1820 const struct iovec *iov, unsigned long nr_segs, 1821 loff_t pos, loff_t *ppos, size_t count) 1822 { 1823 struct file *file = iocb->ki_filp; 1824 struct address_space *mapping = file->f_mapping; 1825 struct inode *vi = mapping->host; 1826 ntfs_inode *ni = NTFS_I(vi); 1827 ntfs_volume *vol = ni->vol; 1828 struct page *pages[NTFS_MAX_PAGES_PER_CLUSTER]; 1829 struct page *cached_page = NULL; 1830 char __user *buf = NULL; 1831 s64 end, ll; 1832 VCN last_vcn; 1833 LCN lcn; 1834 unsigned long flags; 1835 size_t bytes, iov_ofs = 0; /* Offset in the current iovec. */ 1836 ssize_t status, written; 1837 unsigned nr_pages; 1838 int err; 1839 struct pagevec lru_pvec; 1840 1841 ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, " 1842 "pos 0x%llx, count 0x%lx.", 1843 vi->i_ino, (unsigned)le32_to_cpu(ni->type), 1844 (unsigned long long)pos, (unsigned long)count); 1845 if (unlikely(!count)) 1846 return 0; 1847 BUG_ON(NInoMstProtected(ni)); 1848 /* 1849 * If the attribute is not an index root and it is encrypted or 1850 * compressed, we cannot write to it yet. Note we need to check for 1851 * AT_INDEX_ALLOCATION since this is the type of both directory and 1852 * index inodes. 1853 */ 1854 if (ni->type != AT_INDEX_ALLOCATION) { 1855 /* If file is encrypted, deny access, just like NT4. */ 1856 if (NInoEncrypted(ni)) { 1857 /* 1858 * Reminder for later: Encrypted files are _always_ 1859 * non-resident so that the content can always be 1860 * encrypted. 1861 */ 1862 ntfs_debug("Denying write access to encrypted file."); 1863 return -EACCES; 1864 } 1865 if (NInoCompressed(ni)) { 1866 /* Only unnamed $DATA attribute can be compressed. */ 1867 BUG_ON(ni->type != AT_DATA); 1868 BUG_ON(ni->name_len); 1869 /* 1870 * Reminder for later: If resident, the data is not 1871 * actually compressed. Only on the switch to non- 1872 * resident does compression kick in. This is in 1873 * contrast to encrypted files (see above). 1874 */ 1875 ntfs_error(vi->i_sb, "Writing to compressed files is " 1876 "not implemented yet. Sorry."); 1877 return -EOPNOTSUPP; 1878 } 1879 } 1880 /* 1881 * If a previous ntfs_truncate() failed, repeat it and abort if it 1882 * fails again. 1883 */ 1884 if (unlikely(NInoTruncateFailed(ni))) { 1885 down_write(&vi->i_alloc_sem); 1886 err = ntfs_truncate(vi); 1887 up_write(&vi->i_alloc_sem); 1888 if (err || NInoTruncateFailed(ni)) { 1889 if (!err) 1890 err = -EIO; 1891 ntfs_error(vol->sb, "Cannot perform write to inode " 1892 "0x%lx, attribute type 0x%x, because " 1893 "ntfs_truncate() failed (error code " 1894 "%i).", vi->i_ino, 1895 (unsigned)le32_to_cpu(ni->type), err); 1896 return err; 1897 } 1898 } 1899 /* The first byte after the write. */ 1900 end = pos + count; 1901 /* 1902 * If the write goes beyond the allocated size, extend the allocation 1903 * to cover the whole of the write, rounded up to the nearest cluster. 1904 */ 1905 read_lock_irqsave(&ni->size_lock, flags); 1906 ll = ni->allocated_size; 1907 read_unlock_irqrestore(&ni->size_lock, flags); 1908 if (end > ll) { 1909 /* Extend the allocation without changing the data size. */ 1910 ll = ntfs_attr_extend_allocation(ni, end, -1, pos); 1911 if (likely(ll >= 0)) { 1912 BUG_ON(pos >= ll); 1913 /* If the extension was partial truncate the write. */ 1914 if (end > ll) { 1915 ntfs_debug("Truncating write to inode 0x%lx, " 1916 "attribute type 0x%x, because " 1917 "the allocation was only " 1918 "partially extended.", 1919 vi->i_ino, (unsigned) 1920 le32_to_cpu(ni->type)); 1921 end = ll; 1922 count = ll - pos; 1923 } 1924 } else { 1925 err = ll; 1926 read_lock_irqsave(&ni->size_lock, flags); 1927 ll = ni->allocated_size; 1928 read_unlock_irqrestore(&ni->size_lock, flags); 1929 /* Perform a partial write if possible or fail. */ 1930 if (pos < ll) { 1931 ntfs_debug("Truncating write to inode 0x%lx, " 1932 "attribute type 0x%x, because " 1933 "extending the allocation " 1934 "failed (error code %i).", 1935 vi->i_ino, (unsigned) 1936 le32_to_cpu(ni->type), err); 1937 end = ll; 1938 count = ll - pos; 1939 } else { 1940 ntfs_error(vol->sb, "Cannot perform write to " 1941 "inode 0x%lx, attribute type " 1942 "0x%x, because extending the " 1943 "allocation failed (error " 1944 "code %i).", vi->i_ino, 1945 (unsigned) 1946 le32_to_cpu(ni->type), err); 1947 return err; 1948 } 1949 } 1950 } 1951 pagevec_init(&lru_pvec, 0); 1952 written = 0; 1953 /* 1954 * If the write starts beyond the initialized size, extend it up to the 1955 * beginning of the write and initialize all non-sparse space between 1956 * the old initialized size and the new one. This automatically also 1957 * increments the vfs inode->i_size to keep it above or equal to the 1958 * initialized_size. 1959 */ 1960 read_lock_irqsave(&ni->size_lock, flags); 1961 ll = ni->initialized_size; 1962 read_unlock_irqrestore(&ni->size_lock, flags); 1963 if (pos > ll) { 1964 err = ntfs_attr_extend_initialized(ni, pos, &cached_page, 1965 &lru_pvec); 1966 if (err < 0) { 1967 ntfs_error(vol->sb, "Cannot perform write to inode " 1968 "0x%lx, attribute type 0x%x, because " 1969 "extending the initialized size " 1970 "failed (error code %i).", vi->i_ino, 1971 (unsigned)le32_to_cpu(ni->type), err); 1972 status = err; 1973 goto err_out; 1974 } 1975 } 1976 /* 1977 * Determine the number of pages per cluster for non-resident 1978 * attributes. 1979 */ 1980 nr_pages = 1; 1981 if (vol->cluster_size > PAGE_CACHE_SIZE && NInoNonResident(ni)) 1982 nr_pages = vol->cluster_size >> PAGE_CACHE_SHIFT; 1983 /* Finally, perform the actual write. */ 1984 last_vcn = -1; 1985 if (likely(nr_segs == 1)) 1986 buf = iov->iov_base; 1987 do { 1988 VCN vcn; 1989 pgoff_t idx, start_idx; 1990 unsigned ofs, do_pages, u; 1991 size_t copied; 1992 1993 start_idx = idx = pos >> PAGE_CACHE_SHIFT; 1994 ofs = pos & ~PAGE_CACHE_MASK; 1995 bytes = PAGE_CACHE_SIZE - ofs; 1996 do_pages = 1; 1997 if (nr_pages > 1) { 1998 vcn = pos >> vol->cluster_size_bits; 1999 if (vcn != last_vcn) { 2000 last_vcn = vcn; 2001 /* 2002 * Get the lcn of the vcn the write is in. If 2003 * it is a hole, need to lock down all pages in 2004 * the cluster. 2005 */ 2006 down_read(&ni->runlist.lock); 2007 lcn = ntfs_attr_vcn_to_lcn_nolock(ni, pos >> 2008 vol->cluster_size_bits, FALSE); 2009 up_read(&ni->runlist.lock); 2010 if (unlikely(lcn < LCN_HOLE)) { 2011 status = -EIO; 2012 if (lcn == LCN_ENOMEM) 2013 status = -ENOMEM; 2014 else 2015 ntfs_error(vol->sb, "Cannot " 2016 "perform write to " 2017 "inode 0x%lx, " 2018 "attribute type 0x%x, " 2019 "because the attribute " 2020 "is corrupt.", 2021 vi->i_ino, (unsigned) 2022 le32_to_cpu(ni->type)); 2023 break; 2024 } 2025 if (lcn == LCN_HOLE) { 2026 start_idx = (pos & ~(s64) 2027 vol->cluster_size_mask) 2028 >> PAGE_CACHE_SHIFT; 2029 bytes = vol->cluster_size - (pos & 2030 vol->cluster_size_mask); 2031 do_pages = nr_pages; 2032 } 2033 } 2034 } 2035 if (bytes > count) 2036 bytes = count; 2037 /* 2038 * Bring in the user page(s) that we will copy from _first_. 2039 * Otherwise there is a nasty deadlock on copying from the same 2040 * page(s) as we are writing to, without it/them being marked 2041 * up-to-date. Note, at present there is nothing to stop the 2042 * pages being swapped out between us bringing them into memory 2043 * and doing the actual copying. 2044 */ 2045 if (likely(nr_segs == 1)) 2046 ntfs_fault_in_pages_readable(buf, bytes); 2047 else 2048 ntfs_fault_in_pages_readable_iovec(iov, iov_ofs, bytes); 2049 /* Get and lock @do_pages starting at index @start_idx. */ 2050 status = __ntfs_grab_cache_pages(mapping, start_idx, do_pages, 2051 pages, &cached_page, &lru_pvec); 2052 if (unlikely(status)) 2053 break; 2054 /* 2055 * For non-resident attributes, we need to fill any holes with 2056 * actual clusters and ensure all bufferes are mapped. We also 2057 * need to bring uptodate any buffers that are only partially 2058 * being written to. 2059 */ 2060 if (NInoNonResident(ni)) { 2061 status = ntfs_prepare_pages_for_non_resident_write( 2062 pages, do_pages, pos, bytes); 2063 if (unlikely(status)) { 2064 loff_t i_size; 2065 2066 do { 2067 unlock_page(pages[--do_pages]); 2068 page_cache_release(pages[do_pages]); 2069 } while (do_pages); 2070 /* 2071 * The write preparation may have instantiated 2072 * allocated space outside i_size. Trim this 2073 * off again. We can ignore any errors in this 2074 * case as we will just be waisting a bit of 2075 * allocated space, which is not a disaster. 2076 */ 2077 i_size = i_size_read(vi); 2078 if (pos + bytes > i_size) 2079 vmtruncate(vi, i_size); 2080 break; 2081 } 2082 } 2083 u = (pos >> PAGE_CACHE_SHIFT) - pages[0]->index; 2084 if (likely(nr_segs == 1)) { 2085 copied = ntfs_copy_from_user(pages + u, do_pages - u, 2086 ofs, buf, bytes); 2087 buf += copied; 2088 } else 2089 copied = ntfs_copy_from_user_iovec(pages + u, 2090 do_pages - u, ofs, &iov, &iov_ofs, 2091 bytes); 2092 ntfs_flush_dcache_pages(pages + u, do_pages - u); 2093 status = ntfs_commit_pages_after_write(pages, do_pages, pos, 2094 bytes); 2095 if (likely(!status)) { 2096 written += copied; 2097 count -= copied; 2098 pos += copied; 2099 if (unlikely(copied != bytes)) 2100 status = -EFAULT; 2101 } 2102 do { 2103 unlock_page(pages[--do_pages]); 2104 mark_page_accessed(pages[do_pages]); 2105 page_cache_release(pages[do_pages]); 2106 } while (do_pages); 2107 if (unlikely(status)) 2108 break; 2109 balance_dirty_pages_ratelimited(mapping); 2110 cond_resched(); 2111 } while (count); 2112 err_out: 2113 *ppos = pos; 2114 if (cached_page) 2115 page_cache_release(cached_page); 2116 /* For now, when the user asks for O_SYNC, we actually give O_DSYNC. */ 2117 if (likely(!status)) { 2118 if (unlikely((file->f_flags & O_SYNC) || IS_SYNC(vi))) { 2119 if (!mapping->a_ops->writepage || !is_sync_kiocb(iocb)) 2120 status = generic_osync_inode(vi, mapping, 2121 OSYNC_METADATA|OSYNC_DATA); 2122 } 2123 } 2124 pagevec_lru_add(&lru_pvec); 2125 ntfs_debug("Done. Returning %s (written 0x%lx, status %li).", 2126 written ? "written" : "status", (unsigned long)written, 2127 (long)status); 2128 return written ? written : status; 2129 } 2130 2131 /** 2132 * ntfs_file_aio_write_nolock - 2133 */ 2134 static ssize_t ntfs_file_aio_write_nolock(struct kiocb *iocb, 2135 const struct iovec *iov, unsigned long nr_segs, loff_t *ppos) 2136 { 2137 struct file *file = iocb->ki_filp; 2138 struct address_space *mapping = file->f_mapping; 2139 struct inode *inode = mapping->host; 2140 loff_t pos; 2141 unsigned long seg; 2142 size_t count; /* after file limit checks */ 2143 ssize_t written, err; 2144 2145 count = 0; 2146 for (seg = 0; seg < nr_segs; seg++) { 2147 const struct iovec *iv = &iov[seg]; 2148 /* 2149 * If any segment has a negative length, or the cumulative 2150 * length ever wraps negative then return -EINVAL. 2151 */ 2152 count += iv->iov_len; 2153 if (unlikely((ssize_t)(count|iv->iov_len) < 0)) 2154 return -EINVAL; 2155 if (access_ok(VERIFY_READ, iv->iov_base, iv->iov_len)) 2156 continue; 2157 if (!seg) 2158 return -EFAULT; 2159 nr_segs = seg; 2160 count -= iv->iov_len; /* This segment is no good */ 2161 break; 2162 } 2163 pos = *ppos; 2164 vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); 2165 /* We can write back this queue in page reclaim. */ 2166 current->backing_dev_info = mapping->backing_dev_info; 2167 written = 0; 2168 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); 2169 if (err) 2170 goto out; 2171 if (!count) 2172 goto out; 2173 err = remove_suid(file->f_dentry); 2174 if (err) 2175 goto out; 2176 inode_update_time(inode, 1); 2177 written = ntfs_file_buffered_write(iocb, iov, nr_segs, pos, ppos, 2178 count); 2179 out: 2180 current->backing_dev_info = NULL; 2181 return written ? written : err; 2182 } 2183 2184 /** 2185 * ntfs_file_aio_write - 2186 */ 2187 static ssize_t ntfs_file_aio_write(struct kiocb *iocb, const char __user *buf, 2188 size_t count, loff_t pos) 2189 { 2190 struct file *file = iocb->ki_filp; 2191 struct address_space *mapping = file->f_mapping; 2192 struct inode *inode = mapping->host; 2193 ssize_t ret; 2194 struct iovec local_iov = { .iov_base = (void __user *)buf, 2195 .iov_len = count }; 2196 2197 BUG_ON(iocb->ki_pos != pos); 2198 2199 down(&inode->i_sem); 2200 ret = ntfs_file_aio_write_nolock(iocb, &local_iov, 1, &iocb->ki_pos); 2201 up(&inode->i_sem); 2202 if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) { 2203 int err = sync_page_range(inode, mapping, pos, ret); 2204 if (err < 0) 2205 ret = err; 2206 } 2207 return ret; 2208 } 2209 2210 /** 2211 * ntfs_file_writev - 2212 * 2213 * Basically the same as generic_file_writev() except that it ends up calling 2214 * ntfs_file_aio_write_nolock() instead of __generic_file_aio_write_nolock(). 2215 */ 2216 static ssize_t ntfs_file_writev(struct file *file, const struct iovec *iov, 2217 unsigned long nr_segs, loff_t *ppos) 2218 { 2219 struct address_space *mapping = file->f_mapping; 2220 struct inode *inode = mapping->host; 2221 struct kiocb kiocb; 2222 ssize_t ret; 2223 2224 down(&inode->i_sem); 2225 init_sync_kiocb(&kiocb, file); 2226 ret = ntfs_file_aio_write_nolock(&kiocb, iov, nr_segs, ppos); 2227 if (ret == -EIOCBQUEUED) 2228 ret = wait_on_sync_kiocb(&kiocb); 2229 up(&inode->i_sem); 2230 if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) { 2231 int err = sync_page_range(inode, mapping, *ppos - ret, ret); 2232 if (err < 0) 2233 ret = err; 2234 } 2235 return ret; 2236 } 2237 2238 /** 2239 * ntfs_file_write - simple wrapper for ntfs_file_writev() 2240 */ 2241 static ssize_t ntfs_file_write(struct file *file, const char __user *buf, 2242 size_t count, loff_t *ppos) 2243 { 2244 struct iovec local_iov = { .iov_base = (void __user *)buf, 2245 .iov_len = count }; 2246 2247 return ntfs_file_writev(file, &local_iov, 1, ppos); 2248 } 2249 2250 /** 2251 * ntfs_file_fsync - sync a file to disk 2252 * @filp: file to be synced 2253 * @dentry: dentry describing the file to sync 2254 * @datasync: if non-zero only flush user data and not metadata 2255 * 2256 * Data integrity sync of a file to disk. Used for fsync, fdatasync, and msync 2257 * system calls. This function is inspired by fs/buffer.c::file_fsync(). 2258 * 2259 * If @datasync is false, write the mft record and all associated extent mft 2260 * records as well as the $DATA attribute and then sync the block device. 2261 * 2262 * If @datasync is true and the attribute is non-resident, we skip the writing 2263 * of the mft record and all associated extent mft records (this might still 2264 * happen due to the write_inode_now() call). 2265 * 2266 * Also, if @datasync is true, we do not wait on the inode to be written out 2267 * but we always wait on the page cache pages to be written out. 2268 * 2269 * Note: In the past @filp could be NULL so we ignore it as we don't need it 2270 * anyway. 2271 * 2272 * Locking: Caller must hold i_sem on the inode. 2273 * 2274 * TODO: We should probably also write all attribute/index inodes associated 2275 * with this inode but since we have no simple way of getting to them we ignore 2276 * this problem for now. 2277 */ 2278 static int ntfs_file_fsync(struct file *filp, struct dentry *dentry, 2279 int datasync) 2280 { 2281 struct inode *vi = dentry->d_inode; 2282 int err, ret = 0; 2283 2284 ntfs_debug("Entering for inode 0x%lx.", vi->i_ino); 2285 BUG_ON(S_ISDIR(vi->i_mode)); 2286 if (!datasync || !NInoNonResident(NTFS_I(vi))) 2287 ret = ntfs_write_inode(vi, 1); 2288 write_inode_now(vi, !datasync); 2289 /* 2290 * NOTE: If we were to use mapping->private_list (see ext2 and 2291 * fs/buffer.c) for dirty blocks then we could optimize the below to be 2292 * sync_mapping_buffers(vi->i_mapping). 2293 */ 2294 err = sync_blockdev(vi->i_sb->s_bdev); 2295 if (unlikely(err && !ret)) 2296 ret = err; 2297 if (likely(!ret)) 2298 ntfs_debug("Done."); 2299 else 2300 ntfs_warning(vi->i_sb, "Failed to f%ssync inode 0x%lx. Error " 2301 "%u.", datasync ? "data" : "", vi->i_ino, -ret); 2302 return ret; 2303 } 2304 2305 #endif /* NTFS_RW */ 2306 2307 struct file_operations ntfs_file_ops = { 2308 .llseek = generic_file_llseek, /* Seek inside file. */ 2309 .read = generic_file_read, /* Read from file. */ 2310 .aio_read = generic_file_aio_read, /* Async read from file. */ 2311 .readv = generic_file_readv, /* Read from file. */ 2312 #ifdef NTFS_RW 2313 .write = ntfs_file_write, /* Write to file. */ 2314 .aio_write = ntfs_file_aio_write, /* Async write to file. */ 2315 .writev = ntfs_file_writev, /* Write to file. */ 2316 /*.release = ,*/ /* Last file is closed. See 2317 fs/ext2/file.c:: 2318 ext2_release_file() for 2319 how to use this to discard 2320 preallocated space for 2321 write opened files. */ 2322 .fsync = ntfs_file_fsync, /* Sync a file to disk. */ 2323 /*.aio_fsync = ,*/ /* Sync all outstanding async 2324 i/o operations on a 2325 kiocb. */ 2326 #endif /* NTFS_RW */ 2327 /*.ioctl = ,*/ /* Perform function on the 2328 mounted filesystem. */ 2329 .mmap = generic_file_mmap, /* Mmap file. */ 2330 .open = ntfs_file_open, /* Open file. */ 2331 .sendfile = generic_file_sendfile, /* Zero-copy data send with 2332 the data source being on 2333 the ntfs partition. We do 2334 not need to care about the 2335 data destination. */ 2336 /*.sendpage = ,*/ /* Zero-copy data send with 2337 the data destination being 2338 on the ntfs partition. We 2339 do not need to care about 2340 the data source. */ 2341 }; 2342 2343 struct inode_operations ntfs_file_inode_ops = { 2344 #ifdef NTFS_RW 2345 .truncate = ntfs_truncate_vfs, 2346 .setattr = ntfs_setattr, 2347 #endif /* NTFS_RW */ 2348 }; 2349 2350 struct file_operations ntfs_empty_file_ops = {}; 2351 2352 struct inode_operations ntfs_empty_inode_ops = {}; 2353