1 /* 2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. 4 * 5 * This copyrighted material is made available to anyone wishing to use, 6 * modify, copy, or redistribute it subject to the terms and conditions 7 * of the GNU General Public License version 2. 8 */ 9 10 #include <linux/sched.h> 11 #include <linux/slab.h> 12 #include <linux/spinlock.h> 13 #include <linux/completion.h> 14 #include <linux/buffer_head.h> 15 #include <linux/pagemap.h> 16 #include <linux/pagevec.h> 17 #include <linux/mpage.h> 18 #include <linux/fs.h> 19 #include <linux/writeback.h> 20 #include <linux/swap.h> 21 #include <linux/gfs2_ondisk.h> 22 #include <linux/backing-dev.h> 23 24 #include "gfs2.h" 25 #include "incore.h" 26 #include "bmap.h" 27 #include "glock.h" 28 #include "inode.h" 29 #include "log.h" 30 #include "meta_io.h" 31 #include "quota.h" 32 #include "trans.h" 33 #include "rgrp.h" 34 #include "super.h" 35 #include "util.h" 36 #include "glops.h" 37 38 39 static void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page, 40 unsigned int from, unsigned int to) 41 { 42 struct buffer_head *head = page_buffers(page); 43 unsigned int bsize = head->b_size; 44 struct buffer_head *bh; 45 unsigned int start, end; 46 47 for (bh = head, start = 0; bh != head || !start; 48 bh = bh->b_this_page, start = end) { 49 end = start + bsize; 50 if (end <= from || start >= to) 51 continue; 52 if (gfs2_is_jdata(ip)) 53 set_buffer_uptodate(bh); 54 gfs2_trans_add_bh(ip->i_gl, bh, 0); 55 } 56 } 57 58 /** 59 * gfs2_get_block_noalloc - Fills in a buffer head with details about a block 60 * @inode: The inode 61 * @lblock: The block number to look up 62 * @bh_result: The buffer head to return the result in 63 * @create: Non-zero if we may add block to the file 64 * 65 * Returns: errno 66 */ 67 68 static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock, 69 struct buffer_head *bh_result, int create) 70 { 71 int error; 72 73 error = gfs2_block_map(inode, lblock, bh_result, 0); 74 if (error) 75 return error; 76 if (!buffer_mapped(bh_result)) 77 return -EIO; 78 return 0; 79 } 80 81 static int gfs2_get_block_direct(struct inode *inode, sector_t lblock, 82 struct buffer_head *bh_result, int create) 83 { 84 return gfs2_block_map(inode, lblock, bh_result, 0); 85 } 86 87 /** 88 * gfs2_writepage_common - Common bits of writepage 89 * @page: The page to be written 90 * @wbc: The writeback control 91 * 92 * Returns: 1 if writepage is ok, otherwise an error code or zero if no error. 93 */ 94 95 static int gfs2_writepage_common(struct page *page, 96 struct writeback_control *wbc) 97 { 98 struct inode *inode = page->mapping->host; 99 struct gfs2_inode *ip = GFS2_I(inode); 100 struct gfs2_sbd *sdp = GFS2_SB(inode); 101 loff_t i_size = i_size_read(inode); 102 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT; 103 unsigned offset; 104 105 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) 106 goto out; 107 if (current->journal_info) 108 goto redirty; 109 /* Is the page fully outside i_size? (truncate in progress) */ 110 offset = i_size & (PAGE_CACHE_SIZE-1); 111 if (page->index > end_index || (page->index == end_index && !offset)) { 112 page->mapping->a_ops->invalidatepage(page, 0); 113 goto out; 114 } 115 return 1; 116 redirty: 117 redirty_page_for_writepage(wbc, page); 118 out: 119 unlock_page(page); 120 return 0; 121 } 122 123 /** 124 * gfs2_writeback_writepage - Write page for writeback mappings 125 * @page: The page 126 * @wbc: The writeback control 127 * 128 */ 129 130 static int gfs2_writeback_writepage(struct page *page, 131 struct writeback_control *wbc) 132 { 133 int ret; 134 135 ret = gfs2_writepage_common(page, wbc); 136 if (ret <= 0) 137 return ret; 138 139 ret = mpage_writepage(page, gfs2_get_block_noalloc, wbc); 140 if (ret == -EAGAIN) 141 ret = block_write_full_page(page, gfs2_get_block_noalloc, wbc); 142 return ret; 143 } 144 145 /** 146 * gfs2_ordered_writepage - Write page for ordered data files 147 * @page: The page to write 148 * @wbc: The writeback control 149 * 150 */ 151 152 static int gfs2_ordered_writepage(struct page *page, 153 struct writeback_control *wbc) 154 { 155 struct inode *inode = page->mapping->host; 156 struct gfs2_inode *ip = GFS2_I(inode); 157 int ret; 158 159 ret = gfs2_writepage_common(page, wbc); 160 if (ret <= 0) 161 return ret; 162 163 if (!page_has_buffers(page)) { 164 create_empty_buffers(page, inode->i_sb->s_blocksize, 165 (1 << BH_Dirty)|(1 << BH_Uptodate)); 166 } 167 gfs2_page_add_databufs(ip, page, 0, inode->i_sb->s_blocksize-1); 168 return block_write_full_page(page, gfs2_get_block_noalloc, wbc); 169 } 170 171 /** 172 * __gfs2_jdata_writepage - The core of jdata writepage 173 * @page: The page to write 174 * @wbc: The writeback control 175 * 176 * This is shared between writepage and writepages and implements the 177 * core of the writepage operation. If a transaction is required then 178 * PageChecked will have been set and the transaction will have 179 * already been started before this is called. 180 */ 181 182 static int __gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc) 183 { 184 struct inode *inode = page->mapping->host; 185 struct gfs2_inode *ip = GFS2_I(inode); 186 struct gfs2_sbd *sdp = GFS2_SB(inode); 187 188 if (PageChecked(page)) { 189 ClearPageChecked(page); 190 if (!page_has_buffers(page)) { 191 create_empty_buffers(page, inode->i_sb->s_blocksize, 192 (1 << BH_Dirty)|(1 << BH_Uptodate)); 193 } 194 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1); 195 } 196 return block_write_full_page(page, gfs2_get_block_noalloc, wbc); 197 } 198 199 /** 200 * gfs2_jdata_writepage - Write complete page 201 * @page: Page to write 202 * 203 * Returns: errno 204 * 205 */ 206 207 static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc) 208 { 209 struct inode *inode = page->mapping->host; 210 struct gfs2_sbd *sdp = GFS2_SB(inode); 211 int ret; 212 int done_trans = 0; 213 214 if (PageChecked(page)) { 215 if (wbc->sync_mode != WB_SYNC_ALL) 216 goto out_ignore; 217 ret = gfs2_trans_begin(sdp, RES_DINODE + 1, 0); 218 if (ret) 219 goto out_ignore; 220 done_trans = 1; 221 } 222 ret = gfs2_writepage_common(page, wbc); 223 if (ret > 0) 224 ret = __gfs2_jdata_writepage(page, wbc); 225 if (done_trans) 226 gfs2_trans_end(sdp); 227 return ret; 228 229 out_ignore: 230 redirty_page_for_writepage(wbc, page); 231 unlock_page(page); 232 return 0; 233 } 234 235 /** 236 * gfs2_writeback_writepages - Write a bunch of dirty pages back to disk 237 * @mapping: The mapping to write 238 * @wbc: Write-back control 239 * 240 * For the data=writeback case we can already ignore buffer heads 241 * and write whole extents at once. This is a big reduction in the 242 * number of I/O requests we send and the bmap calls we make in this case. 243 */ 244 static int gfs2_writeback_writepages(struct address_space *mapping, 245 struct writeback_control *wbc) 246 { 247 return mpage_writepages(mapping, wbc, gfs2_get_block_noalloc); 248 } 249 250 /** 251 * gfs2_write_jdata_pagevec - Write back a pagevec's worth of pages 252 * @mapping: The mapping 253 * @wbc: The writeback control 254 * @writepage: The writepage function to call for each page 255 * @pvec: The vector of pages 256 * @nr_pages: The number of pages to write 257 * 258 * Returns: non-zero if loop should terminate, zero otherwise 259 */ 260 261 static int gfs2_write_jdata_pagevec(struct address_space *mapping, 262 struct writeback_control *wbc, 263 struct pagevec *pvec, 264 int nr_pages, pgoff_t end) 265 { 266 struct inode *inode = mapping->host; 267 struct gfs2_sbd *sdp = GFS2_SB(inode); 268 loff_t i_size = i_size_read(inode); 269 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT; 270 unsigned offset = i_size & (PAGE_CACHE_SIZE-1); 271 unsigned nrblocks = nr_pages * (PAGE_CACHE_SIZE/inode->i_sb->s_blocksize); 272 int i; 273 int ret; 274 275 ret = gfs2_trans_begin(sdp, nrblocks, nrblocks); 276 if (ret < 0) 277 return ret; 278 279 for(i = 0; i < nr_pages; i++) { 280 struct page *page = pvec->pages[i]; 281 282 lock_page(page); 283 284 if (unlikely(page->mapping != mapping)) { 285 unlock_page(page); 286 continue; 287 } 288 289 if (!wbc->range_cyclic && page->index > end) { 290 ret = 1; 291 unlock_page(page); 292 continue; 293 } 294 295 if (wbc->sync_mode != WB_SYNC_NONE) 296 wait_on_page_writeback(page); 297 298 if (PageWriteback(page) || 299 !clear_page_dirty_for_io(page)) { 300 unlock_page(page); 301 continue; 302 } 303 304 /* Is the page fully outside i_size? (truncate in progress) */ 305 if (page->index > end_index || (page->index == end_index && !offset)) { 306 page->mapping->a_ops->invalidatepage(page, 0); 307 unlock_page(page); 308 continue; 309 } 310 311 ret = __gfs2_jdata_writepage(page, wbc); 312 313 if (ret || (--(wbc->nr_to_write) <= 0)) 314 ret = 1; 315 } 316 gfs2_trans_end(sdp); 317 return ret; 318 } 319 320 /** 321 * gfs2_write_cache_jdata - Like write_cache_pages but different 322 * @mapping: The mapping to write 323 * @wbc: The writeback control 324 * @writepage: The writepage function to call 325 * @data: The data to pass to writepage 326 * 327 * The reason that we use our own function here is that we need to 328 * start transactions before we grab page locks. This allows us 329 * to get the ordering right. 330 */ 331 332 static int gfs2_write_cache_jdata(struct address_space *mapping, 333 struct writeback_control *wbc) 334 { 335 int ret = 0; 336 int done = 0; 337 struct pagevec pvec; 338 int nr_pages; 339 pgoff_t index; 340 pgoff_t end; 341 int scanned = 0; 342 int range_whole = 0; 343 344 pagevec_init(&pvec, 0); 345 if (wbc->range_cyclic) { 346 index = mapping->writeback_index; /* Start from prev offset */ 347 end = -1; 348 } else { 349 index = wbc->range_start >> PAGE_CACHE_SHIFT; 350 end = wbc->range_end >> PAGE_CACHE_SHIFT; 351 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) 352 range_whole = 1; 353 scanned = 1; 354 } 355 356 retry: 357 while (!done && (index <= end) && 358 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, 359 PAGECACHE_TAG_DIRTY, 360 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) { 361 scanned = 1; 362 ret = gfs2_write_jdata_pagevec(mapping, wbc, &pvec, nr_pages, end); 363 if (ret) 364 done = 1; 365 if (ret > 0) 366 ret = 0; 367 368 pagevec_release(&pvec); 369 cond_resched(); 370 } 371 372 if (!scanned && !done) { 373 /* 374 * We hit the last page and there is more work to be done: wrap 375 * back to the start of the file 376 */ 377 scanned = 1; 378 index = 0; 379 goto retry; 380 } 381 382 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) 383 mapping->writeback_index = index; 384 return ret; 385 } 386 387 388 /** 389 * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk 390 * @mapping: The mapping to write 391 * @wbc: The writeback control 392 * 393 */ 394 395 static int gfs2_jdata_writepages(struct address_space *mapping, 396 struct writeback_control *wbc) 397 { 398 struct gfs2_inode *ip = GFS2_I(mapping->host); 399 struct gfs2_sbd *sdp = GFS2_SB(mapping->host); 400 int ret; 401 402 ret = gfs2_write_cache_jdata(mapping, wbc); 403 if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) { 404 gfs2_log_flush(sdp, ip->i_gl); 405 ret = gfs2_write_cache_jdata(mapping, wbc); 406 } 407 return ret; 408 } 409 410 /** 411 * stuffed_readpage - Fill in a Linux page with stuffed file data 412 * @ip: the inode 413 * @page: the page 414 * 415 * Returns: errno 416 */ 417 418 static int stuffed_readpage(struct gfs2_inode *ip, struct page *page) 419 { 420 struct buffer_head *dibh; 421 u64 dsize = i_size_read(&ip->i_inode); 422 void *kaddr; 423 int error; 424 425 /* 426 * Due to the order of unstuffing files and ->fault(), we can be 427 * asked for a zero page in the case of a stuffed file being extended, 428 * so we need to supply one here. It doesn't happen often. 429 */ 430 if (unlikely(page->index)) { 431 zero_user(page, 0, PAGE_CACHE_SIZE); 432 SetPageUptodate(page); 433 return 0; 434 } 435 436 error = gfs2_meta_inode_buffer(ip, &dibh); 437 if (error) 438 return error; 439 440 kaddr = kmap_atomic(page, KM_USER0); 441 if (dsize > (dibh->b_size - sizeof(struct gfs2_dinode))) 442 dsize = (dibh->b_size - sizeof(struct gfs2_dinode)); 443 memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize); 444 memset(kaddr + dsize, 0, PAGE_CACHE_SIZE - dsize); 445 kunmap_atomic(kaddr, KM_USER0); 446 flush_dcache_page(page); 447 brelse(dibh); 448 SetPageUptodate(page); 449 450 return 0; 451 } 452 453 454 /** 455 * __gfs2_readpage - readpage 456 * @file: The file to read a page for 457 * @page: The page to read 458 * 459 * This is the core of gfs2's readpage. Its used by the internal file 460 * reading code as in that case we already hold the glock. Also its 461 * called by gfs2_readpage() once the required lock has been granted. 462 * 463 */ 464 465 static int __gfs2_readpage(void *file, struct page *page) 466 { 467 struct gfs2_inode *ip = GFS2_I(page->mapping->host); 468 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host); 469 int error; 470 471 if (gfs2_is_stuffed(ip)) { 472 error = stuffed_readpage(ip, page); 473 unlock_page(page); 474 } else { 475 error = mpage_readpage(page, gfs2_block_map); 476 } 477 478 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) 479 return -EIO; 480 481 return error; 482 } 483 484 /** 485 * gfs2_readpage - read a page of a file 486 * @file: The file to read 487 * @page: The page of the file 488 * 489 * This deals with the locking required. We have to unlock and 490 * relock the page in order to get the locking in the right 491 * order. 492 */ 493 494 static int gfs2_readpage(struct file *file, struct page *page) 495 { 496 struct address_space *mapping = page->mapping; 497 struct gfs2_inode *ip = GFS2_I(mapping->host); 498 struct gfs2_holder gh; 499 int error; 500 501 unlock_page(page); 502 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh); 503 error = gfs2_glock_nq(&gh); 504 if (unlikely(error)) 505 goto out; 506 error = AOP_TRUNCATED_PAGE; 507 lock_page(page); 508 if (page->mapping == mapping && !PageUptodate(page)) 509 error = __gfs2_readpage(file, page); 510 else 511 unlock_page(page); 512 gfs2_glock_dq(&gh); 513 out: 514 gfs2_holder_uninit(&gh); 515 if (error && error != AOP_TRUNCATED_PAGE) 516 lock_page(page); 517 return error; 518 } 519 520 /** 521 * gfs2_internal_read - read an internal file 522 * @ip: The gfs2 inode 523 * @ra_state: The readahead state (or NULL for no readahead) 524 * @buf: The buffer to fill 525 * @pos: The file position 526 * @size: The amount to read 527 * 528 */ 529 530 int gfs2_internal_read(struct gfs2_inode *ip, struct file_ra_state *ra_state, 531 char *buf, loff_t *pos, unsigned size) 532 { 533 struct address_space *mapping = ip->i_inode.i_mapping; 534 unsigned long index = *pos / PAGE_CACHE_SIZE; 535 unsigned offset = *pos & (PAGE_CACHE_SIZE - 1); 536 unsigned copied = 0; 537 unsigned amt; 538 struct page *page; 539 void *p; 540 541 do { 542 amt = size - copied; 543 if (offset + size > PAGE_CACHE_SIZE) 544 amt = PAGE_CACHE_SIZE - offset; 545 page = read_cache_page(mapping, index, __gfs2_readpage, NULL); 546 if (IS_ERR(page)) 547 return PTR_ERR(page); 548 p = kmap_atomic(page, KM_USER0); 549 memcpy(buf + copied, p + offset, amt); 550 kunmap_atomic(p, KM_USER0); 551 mark_page_accessed(page); 552 page_cache_release(page); 553 copied += amt; 554 index++; 555 offset = 0; 556 } while(copied < size); 557 (*pos) += size; 558 return size; 559 } 560 561 /** 562 * gfs2_readpages - Read a bunch of pages at once 563 * 564 * Some notes: 565 * 1. This is only for readahead, so we can simply ignore any things 566 * which are slightly inconvenient (such as locking conflicts between 567 * the page lock and the glock) and return having done no I/O. Its 568 * obviously not something we'd want to do on too regular a basis. 569 * Any I/O we ignore at this time will be done via readpage later. 570 * 2. We don't handle stuffed files here we let readpage do the honours. 571 * 3. mpage_readpages() does most of the heavy lifting in the common case. 572 * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places. 573 */ 574 575 static int gfs2_readpages(struct file *file, struct address_space *mapping, 576 struct list_head *pages, unsigned nr_pages) 577 { 578 struct inode *inode = mapping->host; 579 struct gfs2_inode *ip = GFS2_I(inode); 580 struct gfs2_sbd *sdp = GFS2_SB(inode); 581 struct gfs2_holder gh; 582 int ret; 583 584 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh); 585 ret = gfs2_glock_nq(&gh); 586 if (unlikely(ret)) 587 goto out_uninit; 588 if (!gfs2_is_stuffed(ip)) 589 ret = mpage_readpages(mapping, pages, nr_pages, gfs2_block_map); 590 gfs2_glock_dq(&gh); 591 out_uninit: 592 gfs2_holder_uninit(&gh); 593 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) 594 ret = -EIO; 595 return ret; 596 } 597 598 /** 599 * gfs2_write_begin - Begin to write to a file 600 * @file: The file to write to 601 * @mapping: The mapping in which to write 602 * @pos: The file offset at which to start writing 603 * @len: Length of the write 604 * @flags: Various flags 605 * @pagep: Pointer to return the page 606 * @fsdata: Pointer to return fs data (unused by GFS2) 607 * 608 * Returns: errno 609 */ 610 611 static int gfs2_write_begin(struct file *file, struct address_space *mapping, 612 loff_t pos, unsigned len, unsigned flags, 613 struct page **pagep, void **fsdata) 614 { 615 struct gfs2_inode *ip = GFS2_I(mapping->host); 616 struct gfs2_sbd *sdp = GFS2_SB(mapping->host); 617 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); 618 unsigned int data_blocks = 0, ind_blocks = 0, rblocks; 619 int alloc_required; 620 int error = 0; 621 struct gfs2_alloc *al; 622 pgoff_t index = pos >> PAGE_CACHE_SHIFT; 623 unsigned from = pos & (PAGE_CACHE_SIZE - 1); 624 unsigned to = from + len; 625 struct page *page; 626 627 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh); 628 error = gfs2_glock_nq(&ip->i_gh); 629 if (unlikely(error)) 630 goto out_uninit; 631 if (&ip->i_inode == sdp->sd_rindex) { 632 error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, 633 GL_NOCACHE, &m_ip->i_gh); 634 if (unlikely(error)) { 635 gfs2_glock_dq(&ip->i_gh); 636 goto out_uninit; 637 } 638 } 639 640 error = gfs2_write_alloc_required(ip, pos, len, &alloc_required); 641 if (error) 642 goto out_unlock; 643 644 if (alloc_required || gfs2_is_jdata(ip)) 645 gfs2_write_calc_reserv(ip, len, &data_blocks, &ind_blocks); 646 647 if (alloc_required) { 648 al = gfs2_alloc_get(ip); 649 if (!al) { 650 error = -ENOMEM; 651 goto out_unlock; 652 } 653 654 error = gfs2_quota_lock_check(ip); 655 if (error) 656 goto out_alloc_put; 657 658 al->al_requested = data_blocks + ind_blocks; 659 error = gfs2_inplace_reserve(ip); 660 if (error) 661 goto out_qunlock; 662 } 663 664 rblocks = RES_DINODE + ind_blocks; 665 if (gfs2_is_jdata(ip)) 666 rblocks += data_blocks ? data_blocks : 1; 667 if (ind_blocks || data_blocks) 668 rblocks += RES_STATFS + RES_QUOTA; 669 if (&ip->i_inode == sdp->sd_rindex) 670 rblocks += 2 * RES_STATFS; 671 672 error = gfs2_trans_begin(sdp, rblocks, 673 PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize); 674 if (error) 675 goto out_trans_fail; 676 677 error = -ENOMEM; 678 flags |= AOP_FLAG_NOFS; 679 page = grab_cache_page_write_begin(mapping, index, flags); 680 *pagep = page; 681 if (unlikely(!page)) 682 goto out_endtrans; 683 684 if (gfs2_is_stuffed(ip)) { 685 error = 0; 686 if (pos + len > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) { 687 error = gfs2_unstuff_dinode(ip, page); 688 if (error == 0) 689 goto prepare_write; 690 } else if (!PageUptodate(page)) { 691 error = stuffed_readpage(ip, page); 692 } 693 goto out; 694 } 695 696 prepare_write: 697 error = block_prepare_write(page, from, to, gfs2_block_map); 698 out: 699 if (error == 0) 700 return 0; 701 702 page_cache_release(page); 703 if (pos + len > ip->i_inode.i_size) 704 vmtruncate(&ip->i_inode, ip->i_inode.i_size); 705 out_endtrans: 706 gfs2_trans_end(sdp); 707 out_trans_fail: 708 if (alloc_required) { 709 gfs2_inplace_release(ip); 710 out_qunlock: 711 gfs2_quota_unlock(ip); 712 out_alloc_put: 713 gfs2_alloc_put(ip); 714 } 715 out_unlock: 716 if (&ip->i_inode == sdp->sd_rindex) { 717 gfs2_glock_dq(&m_ip->i_gh); 718 gfs2_holder_uninit(&m_ip->i_gh); 719 } 720 gfs2_glock_dq(&ip->i_gh); 721 out_uninit: 722 gfs2_holder_uninit(&ip->i_gh); 723 return error; 724 } 725 726 /** 727 * adjust_fs_space - Adjusts the free space available due to gfs2_grow 728 * @inode: the rindex inode 729 */ 730 static void adjust_fs_space(struct inode *inode) 731 { 732 struct gfs2_sbd *sdp = inode->i_sb->s_fs_info; 733 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); 734 struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode); 735 struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master; 736 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local; 737 struct buffer_head *m_bh, *l_bh; 738 u64 fs_total, new_free; 739 740 /* Total up the file system space, according to the latest rindex. */ 741 fs_total = gfs2_ri_total(sdp); 742 if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0) 743 return; 744 745 spin_lock(&sdp->sd_statfs_spin); 746 gfs2_statfs_change_in(m_sc, m_bh->b_data + 747 sizeof(struct gfs2_dinode)); 748 if (fs_total > (m_sc->sc_total + l_sc->sc_total)) 749 new_free = fs_total - (m_sc->sc_total + l_sc->sc_total); 750 else 751 new_free = 0; 752 spin_unlock(&sdp->sd_statfs_spin); 753 fs_warn(sdp, "File system extended by %llu blocks.\n", 754 (unsigned long long)new_free); 755 gfs2_statfs_change(sdp, new_free, new_free, 0); 756 757 if (gfs2_meta_inode_buffer(l_ip, &l_bh) != 0) 758 goto out; 759 update_statfs(sdp, m_bh, l_bh); 760 brelse(l_bh); 761 out: 762 brelse(m_bh); 763 } 764 765 /** 766 * gfs2_stuffed_write_end - Write end for stuffed files 767 * @inode: The inode 768 * @dibh: The buffer_head containing the on-disk inode 769 * @pos: The file position 770 * @len: The length of the write 771 * @copied: How much was actually copied by the VFS 772 * @page: The page 773 * 774 * This copies the data from the page into the inode block after 775 * the inode data structure itself. 776 * 777 * Returns: errno 778 */ 779 static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh, 780 loff_t pos, unsigned len, unsigned copied, 781 struct page *page) 782 { 783 struct gfs2_inode *ip = GFS2_I(inode); 784 struct gfs2_sbd *sdp = GFS2_SB(inode); 785 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); 786 u64 to = pos + copied; 787 void *kaddr; 788 unsigned char *buf = dibh->b_data + sizeof(struct gfs2_dinode); 789 struct gfs2_dinode *di = (struct gfs2_dinode *)dibh->b_data; 790 791 BUG_ON((pos + len) > (dibh->b_size - sizeof(struct gfs2_dinode))); 792 kaddr = kmap_atomic(page, KM_USER0); 793 memcpy(buf + pos, kaddr + pos, copied); 794 memset(kaddr + pos + copied, 0, len - copied); 795 flush_dcache_page(page); 796 kunmap_atomic(kaddr, KM_USER0); 797 798 if (!PageUptodate(page)) 799 SetPageUptodate(page); 800 unlock_page(page); 801 page_cache_release(page); 802 803 if (copied) { 804 if (inode->i_size < to) { 805 i_size_write(inode, to); 806 ip->i_disksize = inode->i_size; 807 } 808 gfs2_dinode_out(ip, di); 809 mark_inode_dirty(inode); 810 } 811 812 if (inode == sdp->sd_rindex) { 813 adjust_fs_space(inode); 814 ip->i_gh.gh_flags |= GL_NOCACHE; 815 } 816 817 brelse(dibh); 818 gfs2_trans_end(sdp); 819 if (inode == sdp->sd_rindex) { 820 gfs2_glock_dq(&m_ip->i_gh); 821 gfs2_holder_uninit(&m_ip->i_gh); 822 } 823 gfs2_glock_dq(&ip->i_gh); 824 gfs2_holder_uninit(&ip->i_gh); 825 return copied; 826 } 827 828 /** 829 * gfs2_write_end 830 * @file: The file to write to 831 * @mapping: The address space to write to 832 * @pos: The file position 833 * @len: The length of the data 834 * @copied: 835 * @page: The page that has been written 836 * @fsdata: The fsdata (unused in GFS2) 837 * 838 * The main write_end function for GFS2. We have a separate one for 839 * stuffed files as they are slightly different, otherwise we just 840 * put our locking around the VFS provided functions. 841 * 842 * Returns: errno 843 */ 844 845 static int gfs2_write_end(struct file *file, struct address_space *mapping, 846 loff_t pos, unsigned len, unsigned copied, 847 struct page *page, void *fsdata) 848 { 849 struct inode *inode = page->mapping->host; 850 struct gfs2_inode *ip = GFS2_I(inode); 851 struct gfs2_sbd *sdp = GFS2_SB(inode); 852 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); 853 struct buffer_head *dibh; 854 struct gfs2_alloc *al = ip->i_alloc; 855 unsigned int from = pos & (PAGE_CACHE_SIZE - 1); 856 unsigned int to = from + len; 857 int ret; 858 859 BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == NULL); 860 861 ret = gfs2_meta_inode_buffer(ip, &dibh); 862 if (unlikely(ret)) { 863 unlock_page(page); 864 page_cache_release(page); 865 goto failed; 866 } 867 868 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 869 870 if (gfs2_is_stuffed(ip)) 871 return gfs2_stuffed_write_end(inode, dibh, pos, len, copied, page); 872 873 if (!gfs2_is_writeback(ip)) 874 gfs2_page_add_databufs(ip, page, from, to); 875 876 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); 877 if (ret > 0) { 878 if (inode->i_size > ip->i_disksize) 879 ip->i_disksize = inode->i_size; 880 gfs2_dinode_out(ip, dibh->b_data); 881 mark_inode_dirty(inode); 882 } 883 884 if (inode == sdp->sd_rindex) { 885 adjust_fs_space(inode); 886 ip->i_gh.gh_flags |= GL_NOCACHE; 887 } 888 889 brelse(dibh); 890 gfs2_trans_end(sdp); 891 failed: 892 if (al) { 893 gfs2_inplace_release(ip); 894 gfs2_quota_unlock(ip); 895 gfs2_alloc_put(ip); 896 } 897 if (inode == sdp->sd_rindex) { 898 gfs2_glock_dq(&m_ip->i_gh); 899 gfs2_holder_uninit(&m_ip->i_gh); 900 } 901 gfs2_glock_dq(&ip->i_gh); 902 gfs2_holder_uninit(&ip->i_gh); 903 return ret; 904 } 905 906 /** 907 * gfs2_set_page_dirty - Page dirtying function 908 * @page: The page to dirty 909 * 910 * Returns: 1 if it dirtyed the page, or 0 otherwise 911 */ 912 913 static int gfs2_set_page_dirty(struct page *page) 914 { 915 SetPageChecked(page); 916 return __set_page_dirty_buffers(page); 917 } 918 919 /** 920 * gfs2_bmap - Block map function 921 * @mapping: Address space info 922 * @lblock: The block to map 923 * 924 * Returns: The disk address for the block or 0 on hole or error 925 */ 926 927 static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock) 928 { 929 struct gfs2_inode *ip = GFS2_I(mapping->host); 930 struct gfs2_holder i_gh; 931 sector_t dblock = 0; 932 int error; 933 934 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh); 935 if (error) 936 return 0; 937 938 if (!gfs2_is_stuffed(ip)) 939 dblock = generic_block_bmap(mapping, lblock, gfs2_block_map); 940 941 gfs2_glock_dq_uninit(&i_gh); 942 943 return dblock; 944 } 945 946 static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh) 947 { 948 struct gfs2_bufdata *bd; 949 950 lock_buffer(bh); 951 gfs2_log_lock(sdp); 952 clear_buffer_dirty(bh); 953 bd = bh->b_private; 954 if (bd) { 955 if (!list_empty(&bd->bd_le.le_list) && !buffer_pinned(bh)) 956 list_del_init(&bd->bd_le.le_list); 957 else 958 gfs2_remove_from_journal(bh, current->journal_info, 0); 959 } 960 bh->b_bdev = NULL; 961 clear_buffer_mapped(bh); 962 clear_buffer_req(bh); 963 clear_buffer_new(bh); 964 gfs2_log_unlock(sdp); 965 unlock_buffer(bh); 966 } 967 968 static void gfs2_invalidatepage(struct page *page, unsigned long offset) 969 { 970 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host); 971 struct buffer_head *bh, *head; 972 unsigned long pos = 0; 973 974 BUG_ON(!PageLocked(page)); 975 if (offset == 0) 976 ClearPageChecked(page); 977 if (!page_has_buffers(page)) 978 goto out; 979 980 bh = head = page_buffers(page); 981 do { 982 if (offset <= pos) 983 gfs2_discard(sdp, bh); 984 pos += bh->b_size; 985 bh = bh->b_this_page; 986 } while (bh != head); 987 out: 988 if (offset == 0) 989 try_to_release_page(page, 0); 990 } 991 992 /** 993 * gfs2_ok_for_dio - check that dio is valid on this file 994 * @ip: The inode 995 * @rw: READ or WRITE 996 * @offset: The offset at which we are reading or writing 997 * 998 * Returns: 0 (to ignore the i/o request and thus fall back to buffered i/o) 999 * 1 (to accept the i/o request) 1000 */ 1001 static int gfs2_ok_for_dio(struct gfs2_inode *ip, int rw, loff_t offset) 1002 { 1003 /* 1004 * Should we return an error here? I can't see that O_DIRECT for 1005 * a stuffed file makes any sense. For now we'll silently fall 1006 * back to buffered I/O 1007 */ 1008 if (gfs2_is_stuffed(ip)) 1009 return 0; 1010 1011 if (offset >= i_size_read(&ip->i_inode)) 1012 return 0; 1013 return 1; 1014 } 1015 1016 1017 1018 static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb, 1019 const struct iovec *iov, loff_t offset, 1020 unsigned long nr_segs) 1021 { 1022 struct file *file = iocb->ki_filp; 1023 struct inode *inode = file->f_mapping->host; 1024 struct gfs2_inode *ip = GFS2_I(inode); 1025 struct gfs2_holder gh; 1026 int rv; 1027 1028 /* 1029 * Deferred lock, even if its a write, since we do no allocation 1030 * on this path. All we need change is atime, and this lock mode 1031 * ensures that other nodes have flushed their buffered read caches 1032 * (i.e. their page cache entries for this inode). We do not, 1033 * unfortunately have the option of only flushing a range like 1034 * the VFS does. 1035 */ 1036 gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, &gh); 1037 rv = gfs2_glock_nq(&gh); 1038 if (rv) 1039 return rv; 1040 rv = gfs2_ok_for_dio(ip, rw, offset); 1041 if (rv != 1) 1042 goto out; /* dio not valid, fall back to buffered i/o */ 1043 1044 rv = blockdev_direct_IO_no_locking(rw, iocb, inode, inode->i_sb->s_bdev, 1045 iov, offset, nr_segs, 1046 gfs2_get_block_direct, NULL); 1047 out: 1048 gfs2_glock_dq_m(1, &gh); 1049 gfs2_holder_uninit(&gh); 1050 return rv; 1051 } 1052 1053 /** 1054 * gfs2_releasepage - free the metadata associated with a page 1055 * @page: the page that's being released 1056 * @gfp_mask: passed from Linux VFS, ignored by us 1057 * 1058 * Call try_to_free_buffers() if the buffers in this page can be 1059 * released. 1060 * 1061 * Returns: 0 1062 */ 1063 1064 int gfs2_releasepage(struct page *page, gfp_t gfp_mask) 1065 { 1066 struct address_space *mapping = page->mapping; 1067 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping); 1068 struct buffer_head *bh, *head; 1069 struct gfs2_bufdata *bd; 1070 1071 if (!page_has_buffers(page)) 1072 return 0; 1073 1074 gfs2_log_lock(sdp); 1075 head = bh = page_buffers(page); 1076 do { 1077 if (atomic_read(&bh->b_count)) 1078 goto cannot_release; 1079 bd = bh->b_private; 1080 if (bd && bd->bd_ail) 1081 goto cannot_release; 1082 gfs2_assert_warn(sdp, !buffer_pinned(bh)); 1083 gfs2_assert_warn(sdp, !buffer_dirty(bh)); 1084 bh = bh->b_this_page; 1085 } while(bh != head); 1086 gfs2_log_unlock(sdp); 1087 1088 head = bh = page_buffers(page); 1089 do { 1090 gfs2_log_lock(sdp); 1091 bd = bh->b_private; 1092 if (bd) { 1093 gfs2_assert_warn(sdp, bd->bd_bh == bh); 1094 gfs2_assert_warn(sdp, list_empty(&bd->bd_list_tr)); 1095 if (!list_empty(&bd->bd_le.le_list)) { 1096 if (!buffer_pinned(bh)) 1097 list_del_init(&bd->bd_le.le_list); 1098 else 1099 bd = NULL; 1100 } 1101 if (bd) 1102 bd->bd_bh = NULL; 1103 bh->b_private = NULL; 1104 } 1105 gfs2_log_unlock(sdp); 1106 if (bd) 1107 kmem_cache_free(gfs2_bufdata_cachep, bd); 1108 1109 bh = bh->b_this_page; 1110 } while (bh != head); 1111 1112 return try_to_free_buffers(page); 1113 cannot_release: 1114 gfs2_log_unlock(sdp); 1115 return 0; 1116 } 1117 1118 static const struct address_space_operations gfs2_writeback_aops = { 1119 .writepage = gfs2_writeback_writepage, 1120 .writepages = gfs2_writeback_writepages, 1121 .readpage = gfs2_readpage, 1122 .readpages = gfs2_readpages, 1123 .sync_page = block_sync_page, 1124 .write_begin = gfs2_write_begin, 1125 .write_end = gfs2_write_end, 1126 .bmap = gfs2_bmap, 1127 .invalidatepage = gfs2_invalidatepage, 1128 .releasepage = gfs2_releasepage, 1129 .direct_IO = gfs2_direct_IO, 1130 .migratepage = buffer_migrate_page, 1131 .is_partially_uptodate = block_is_partially_uptodate, 1132 .error_remove_page = generic_error_remove_page, 1133 }; 1134 1135 static const struct address_space_operations gfs2_ordered_aops = { 1136 .writepage = gfs2_ordered_writepage, 1137 .readpage = gfs2_readpage, 1138 .readpages = gfs2_readpages, 1139 .sync_page = block_sync_page, 1140 .write_begin = gfs2_write_begin, 1141 .write_end = gfs2_write_end, 1142 .set_page_dirty = gfs2_set_page_dirty, 1143 .bmap = gfs2_bmap, 1144 .invalidatepage = gfs2_invalidatepage, 1145 .releasepage = gfs2_releasepage, 1146 .direct_IO = gfs2_direct_IO, 1147 .migratepage = buffer_migrate_page, 1148 .is_partially_uptodate = block_is_partially_uptodate, 1149 .error_remove_page = generic_error_remove_page, 1150 }; 1151 1152 static const struct address_space_operations gfs2_jdata_aops = { 1153 .writepage = gfs2_jdata_writepage, 1154 .writepages = gfs2_jdata_writepages, 1155 .readpage = gfs2_readpage, 1156 .readpages = gfs2_readpages, 1157 .sync_page = block_sync_page, 1158 .write_begin = gfs2_write_begin, 1159 .write_end = gfs2_write_end, 1160 .set_page_dirty = gfs2_set_page_dirty, 1161 .bmap = gfs2_bmap, 1162 .invalidatepage = gfs2_invalidatepage, 1163 .releasepage = gfs2_releasepage, 1164 .is_partially_uptodate = block_is_partially_uptodate, 1165 .error_remove_page = generic_error_remove_page, 1166 }; 1167 1168 void gfs2_set_aops(struct inode *inode) 1169 { 1170 struct gfs2_inode *ip = GFS2_I(inode); 1171 1172 if (gfs2_is_writeback(ip)) 1173 inode->i_mapping->a_ops = &gfs2_writeback_aops; 1174 else if (gfs2_is_ordered(ip)) 1175 inode->i_mapping->a_ops = &gfs2_ordered_aops; 1176 else if (gfs2_is_jdata(ip)) 1177 inode->i_mapping->a_ops = &gfs2_jdata_aops; 1178 else 1179 BUG(); 1180 } 1181 1182