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 return nobh_writepage(page, gfs2_get_block_noalloc, wbc); 140 } 141 142 /** 143 * gfs2_ordered_writepage - Write page for ordered data files 144 * @page: The page to write 145 * @wbc: The writeback control 146 * 147 */ 148 149 static int gfs2_ordered_writepage(struct page *page, 150 struct writeback_control *wbc) 151 { 152 struct inode *inode = page->mapping->host; 153 struct gfs2_inode *ip = GFS2_I(inode); 154 int ret; 155 156 ret = gfs2_writepage_common(page, wbc); 157 if (ret <= 0) 158 return ret; 159 160 if (!page_has_buffers(page)) { 161 create_empty_buffers(page, inode->i_sb->s_blocksize, 162 (1 << BH_Dirty)|(1 << BH_Uptodate)); 163 } 164 gfs2_page_add_databufs(ip, page, 0, inode->i_sb->s_blocksize-1); 165 return block_write_full_page(page, gfs2_get_block_noalloc, wbc); 166 } 167 168 /** 169 * __gfs2_jdata_writepage - The core of jdata writepage 170 * @page: The page to write 171 * @wbc: The writeback control 172 * 173 * This is shared between writepage and writepages and implements the 174 * core of the writepage operation. If a transaction is required then 175 * PageChecked will have been set and the transaction will have 176 * already been started before this is called. 177 */ 178 179 static int __gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc) 180 { 181 struct inode *inode = page->mapping->host; 182 struct gfs2_inode *ip = GFS2_I(inode); 183 struct gfs2_sbd *sdp = GFS2_SB(inode); 184 185 if (PageChecked(page)) { 186 ClearPageChecked(page); 187 if (!page_has_buffers(page)) { 188 create_empty_buffers(page, inode->i_sb->s_blocksize, 189 (1 << BH_Dirty)|(1 << BH_Uptodate)); 190 } 191 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1); 192 } 193 return block_write_full_page(page, gfs2_get_block_noalloc, wbc); 194 } 195 196 /** 197 * gfs2_jdata_writepage - Write complete page 198 * @page: Page to write 199 * 200 * Returns: errno 201 * 202 */ 203 204 static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc) 205 { 206 struct inode *inode = page->mapping->host; 207 struct gfs2_sbd *sdp = GFS2_SB(inode); 208 int ret; 209 int done_trans = 0; 210 211 if (PageChecked(page)) { 212 if (wbc->sync_mode != WB_SYNC_ALL) 213 goto out_ignore; 214 ret = gfs2_trans_begin(sdp, RES_DINODE + 1, 0); 215 if (ret) 216 goto out_ignore; 217 done_trans = 1; 218 } 219 ret = gfs2_writepage_common(page, wbc); 220 if (ret > 0) 221 ret = __gfs2_jdata_writepage(page, wbc); 222 if (done_trans) 223 gfs2_trans_end(sdp); 224 return ret; 225 226 out_ignore: 227 redirty_page_for_writepage(wbc, page); 228 unlock_page(page); 229 return 0; 230 } 231 232 /** 233 * gfs2_writeback_writepages - Write a bunch of dirty pages back to disk 234 * @mapping: The mapping to write 235 * @wbc: Write-back control 236 * 237 * For the data=writeback case we can already ignore buffer heads 238 * and write whole extents at once. This is a big reduction in the 239 * number of I/O requests we send and the bmap calls we make in this case. 240 */ 241 static int gfs2_writeback_writepages(struct address_space *mapping, 242 struct writeback_control *wbc) 243 { 244 return mpage_writepages(mapping, wbc, gfs2_get_block_noalloc); 245 } 246 247 /** 248 * gfs2_write_jdata_pagevec - Write back a pagevec's worth of pages 249 * @mapping: The mapping 250 * @wbc: The writeback control 251 * @writepage: The writepage function to call for each page 252 * @pvec: The vector of pages 253 * @nr_pages: The number of pages to write 254 * 255 * Returns: non-zero if loop should terminate, zero otherwise 256 */ 257 258 static int gfs2_write_jdata_pagevec(struct address_space *mapping, 259 struct writeback_control *wbc, 260 struct pagevec *pvec, 261 int nr_pages, pgoff_t end) 262 { 263 struct inode *inode = mapping->host; 264 struct gfs2_sbd *sdp = GFS2_SB(inode); 265 loff_t i_size = i_size_read(inode); 266 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT; 267 unsigned offset = i_size & (PAGE_CACHE_SIZE-1); 268 unsigned nrblocks = nr_pages * (PAGE_CACHE_SIZE/inode->i_sb->s_blocksize); 269 int i; 270 int ret; 271 272 ret = gfs2_trans_begin(sdp, nrblocks, nrblocks); 273 if (ret < 0) 274 return ret; 275 276 for(i = 0; i < nr_pages; i++) { 277 struct page *page = pvec->pages[i]; 278 279 lock_page(page); 280 281 if (unlikely(page->mapping != mapping)) { 282 unlock_page(page); 283 continue; 284 } 285 286 if (!wbc->range_cyclic && page->index > end) { 287 ret = 1; 288 unlock_page(page); 289 continue; 290 } 291 292 if (wbc->sync_mode != WB_SYNC_NONE) 293 wait_on_page_writeback(page); 294 295 if (PageWriteback(page) || 296 !clear_page_dirty_for_io(page)) { 297 unlock_page(page); 298 continue; 299 } 300 301 /* Is the page fully outside i_size? (truncate in progress) */ 302 if (page->index > end_index || (page->index == end_index && !offset)) { 303 page->mapping->a_ops->invalidatepage(page, 0); 304 unlock_page(page); 305 continue; 306 } 307 308 ret = __gfs2_jdata_writepage(page, wbc); 309 310 if (ret || (--(wbc->nr_to_write) <= 0)) 311 ret = 1; 312 } 313 gfs2_trans_end(sdp); 314 return ret; 315 } 316 317 /** 318 * gfs2_write_cache_jdata - Like write_cache_pages but different 319 * @mapping: The mapping to write 320 * @wbc: The writeback control 321 * @writepage: The writepage function to call 322 * @data: The data to pass to writepage 323 * 324 * The reason that we use our own function here is that we need to 325 * start transactions before we grab page locks. This allows us 326 * to get the ordering right. 327 */ 328 329 static int gfs2_write_cache_jdata(struct address_space *mapping, 330 struct writeback_control *wbc) 331 { 332 int ret = 0; 333 int done = 0; 334 struct pagevec pvec; 335 int nr_pages; 336 pgoff_t index; 337 pgoff_t end; 338 int scanned = 0; 339 int range_whole = 0; 340 341 pagevec_init(&pvec, 0); 342 if (wbc->range_cyclic) { 343 index = mapping->writeback_index; /* Start from prev offset */ 344 end = -1; 345 } else { 346 index = wbc->range_start >> PAGE_CACHE_SHIFT; 347 end = wbc->range_end >> PAGE_CACHE_SHIFT; 348 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) 349 range_whole = 1; 350 scanned = 1; 351 } 352 353 retry: 354 while (!done && (index <= end) && 355 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, 356 PAGECACHE_TAG_DIRTY, 357 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) { 358 scanned = 1; 359 ret = gfs2_write_jdata_pagevec(mapping, wbc, &pvec, nr_pages, end); 360 if (ret) 361 done = 1; 362 if (ret > 0) 363 ret = 0; 364 365 pagevec_release(&pvec); 366 cond_resched(); 367 } 368 369 if (!scanned && !done) { 370 /* 371 * We hit the last page and there is more work to be done: wrap 372 * back to the start of the file 373 */ 374 scanned = 1; 375 index = 0; 376 goto retry; 377 } 378 379 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) 380 mapping->writeback_index = index; 381 return ret; 382 } 383 384 385 /** 386 * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk 387 * @mapping: The mapping to write 388 * @wbc: The writeback control 389 * 390 */ 391 392 static int gfs2_jdata_writepages(struct address_space *mapping, 393 struct writeback_control *wbc) 394 { 395 struct gfs2_inode *ip = GFS2_I(mapping->host); 396 struct gfs2_sbd *sdp = GFS2_SB(mapping->host); 397 int ret; 398 399 ret = gfs2_write_cache_jdata(mapping, wbc); 400 if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) { 401 gfs2_log_flush(sdp, ip->i_gl); 402 ret = gfs2_write_cache_jdata(mapping, wbc); 403 } 404 return ret; 405 } 406 407 /** 408 * stuffed_readpage - Fill in a Linux page with stuffed file data 409 * @ip: the inode 410 * @page: the page 411 * 412 * Returns: errno 413 */ 414 415 static int stuffed_readpage(struct gfs2_inode *ip, struct page *page) 416 { 417 struct buffer_head *dibh; 418 u64 dsize = i_size_read(&ip->i_inode); 419 void *kaddr; 420 int error; 421 422 /* 423 * Due to the order of unstuffing files and ->fault(), we can be 424 * asked for a zero page in the case of a stuffed file being extended, 425 * so we need to supply one here. It doesn't happen often. 426 */ 427 if (unlikely(page->index)) { 428 zero_user(page, 0, PAGE_CACHE_SIZE); 429 SetPageUptodate(page); 430 return 0; 431 } 432 433 error = gfs2_meta_inode_buffer(ip, &dibh); 434 if (error) 435 return error; 436 437 kaddr = kmap_atomic(page); 438 if (dsize > (dibh->b_size - sizeof(struct gfs2_dinode))) 439 dsize = (dibh->b_size - sizeof(struct gfs2_dinode)); 440 memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize); 441 memset(kaddr + dsize, 0, PAGE_CACHE_SIZE - dsize); 442 kunmap_atomic(kaddr); 443 flush_dcache_page(page); 444 brelse(dibh); 445 SetPageUptodate(page); 446 447 return 0; 448 } 449 450 451 /** 452 * __gfs2_readpage - readpage 453 * @file: The file to read a page for 454 * @page: The page to read 455 * 456 * This is the core of gfs2's readpage. Its used by the internal file 457 * reading code as in that case we already hold the glock. Also its 458 * called by gfs2_readpage() once the required lock has been granted. 459 * 460 */ 461 462 static int __gfs2_readpage(void *file, struct page *page) 463 { 464 struct gfs2_inode *ip = GFS2_I(page->mapping->host); 465 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host); 466 int error; 467 468 if (gfs2_is_stuffed(ip)) { 469 error = stuffed_readpage(ip, page); 470 unlock_page(page); 471 } else { 472 error = mpage_readpage(page, gfs2_block_map); 473 } 474 475 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) 476 return -EIO; 477 478 return error; 479 } 480 481 /** 482 * gfs2_readpage - read a page of a file 483 * @file: The file to read 484 * @page: The page of the file 485 * 486 * This deals with the locking required. We have to unlock and 487 * relock the page in order to get the locking in the right 488 * order. 489 */ 490 491 static int gfs2_readpage(struct file *file, struct page *page) 492 { 493 struct address_space *mapping = page->mapping; 494 struct gfs2_inode *ip = GFS2_I(mapping->host); 495 struct gfs2_holder gh; 496 int error; 497 498 unlock_page(page); 499 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh); 500 error = gfs2_glock_nq(&gh); 501 if (unlikely(error)) 502 goto out; 503 error = AOP_TRUNCATED_PAGE; 504 lock_page(page); 505 if (page->mapping == mapping && !PageUptodate(page)) 506 error = __gfs2_readpage(file, page); 507 else 508 unlock_page(page); 509 gfs2_glock_dq(&gh); 510 out: 511 gfs2_holder_uninit(&gh); 512 if (error && error != AOP_TRUNCATED_PAGE) 513 lock_page(page); 514 return error; 515 } 516 517 /** 518 * gfs2_internal_read - read an internal file 519 * @ip: The gfs2 inode 520 * @buf: The buffer to fill 521 * @pos: The file position 522 * @size: The amount to read 523 * 524 */ 525 526 int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos, 527 unsigned size) 528 { 529 struct address_space *mapping = ip->i_inode.i_mapping; 530 unsigned long index = *pos / PAGE_CACHE_SIZE; 531 unsigned offset = *pos & (PAGE_CACHE_SIZE - 1); 532 unsigned copied = 0; 533 unsigned amt; 534 struct page *page; 535 void *p; 536 537 do { 538 amt = size - copied; 539 if (offset + size > PAGE_CACHE_SIZE) 540 amt = PAGE_CACHE_SIZE - offset; 541 page = read_cache_page(mapping, index, __gfs2_readpage, NULL); 542 if (IS_ERR(page)) 543 return PTR_ERR(page); 544 p = kmap_atomic(page); 545 memcpy(buf + copied, p + offset, amt); 546 kunmap_atomic(p); 547 mark_page_accessed(page); 548 page_cache_release(page); 549 copied += amt; 550 index++; 551 offset = 0; 552 } while(copied < size); 553 (*pos) += size; 554 return size; 555 } 556 557 /** 558 * gfs2_readpages - Read a bunch of pages at once 559 * 560 * Some notes: 561 * 1. This is only for readahead, so we can simply ignore any things 562 * which are slightly inconvenient (such as locking conflicts between 563 * the page lock and the glock) and return having done no I/O. Its 564 * obviously not something we'd want to do on too regular a basis. 565 * Any I/O we ignore at this time will be done via readpage later. 566 * 2. We don't handle stuffed files here we let readpage do the honours. 567 * 3. mpage_readpages() does most of the heavy lifting in the common case. 568 * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places. 569 */ 570 571 static int gfs2_readpages(struct file *file, struct address_space *mapping, 572 struct list_head *pages, unsigned nr_pages) 573 { 574 struct inode *inode = mapping->host; 575 struct gfs2_inode *ip = GFS2_I(inode); 576 struct gfs2_sbd *sdp = GFS2_SB(inode); 577 struct gfs2_holder gh; 578 int ret; 579 580 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh); 581 ret = gfs2_glock_nq(&gh); 582 if (unlikely(ret)) 583 goto out_uninit; 584 if (!gfs2_is_stuffed(ip)) 585 ret = mpage_readpages(mapping, pages, nr_pages, gfs2_block_map); 586 gfs2_glock_dq(&gh); 587 out_uninit: 588 gfs2_holder_uninit(&gh); 589 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) 590 ret = -EIO; 591 return ret; 592 } 593 594 /** 595 * gfs2_write_begin - Begin to write to a file 596 * @file: The file to write to 597 * @mapping: The mapping in which to write 598 * @pos: The file offset at which to start writing 599 * @len: Length of the write 600 * @flags: Various flags 601 * @pagep: Pointer to return the page 602 * @fsdata: Pointer to return fs data (unused by GFS2) 603 * 604 * Returns: errno 605 */ 606 607 static int gfs2_write_begin(struct file *file, struct address_space *mapping, 608 loff_t pos, unsigned len, unsigned flags, 609 struct page **pagep, void **fsdata) 610 { 611 struct gfs2_inode *ip = GFS2_I(mapping->host); 612 struct gfs2_sbd *sdp = GFS2_SB(mapping->host); 613 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); 614 unsigned int data_blocks = 0, ind_blocks = 0, rblocks; 615 int alloc_required; 616 int error = 0; 617 struct gfs2_qadata *qa = NULL; 618 pgoff_t index = pos >> PAGE_CACHE_SHIFT; 619 unsigned from = pos & (PAGE_CACHE_SIZE - 1); 620 struct page *page; 621 622 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh); 623 error = gfs2_glock_nq(&ip->i_gh); 624 if (unlikely(error)) 625 goto out_uninit; 626 if (&ip->i_inode == sdp->sd_rindex) { 627 error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, 628 GL_NOCACHE, &m_ip->i_gh); 629 if (unlikely(error)) { 630 gfs2_glock_dq(&ip->i_gh); 631 goto out_uninit; 632 } 633 } 634 635 alloc_required = gfs2_write_alloc_required(ip, pos, len); 636 637 if (alloc_required || gfs2_is_jdata(ip)) 638 gfs2_write_calc_reserv(ip, len, &data_blocks, &ind_blocks); 639 640 if (alloc_required) { 641 qa = gfs2_qadata_get(ip); 642 if (!qa) { 643 error = -ENOMEM; 644 goto out_unlock; 645 } 646 647 error = gfs2_quota_lock_check(ip); 648 if (error) 649 goto out_alloc_put; 650 651 error = gfs2_inplace_reserve(ip, data_blocks + ind_blocks); 652 if (error) 653 goto out_qunlock; 654 } 655 656 rblocks = RES_DINODE + ind_blocks; 657 if (gfs2_is_jdata(ip)) 658 rblocks += data_blocks ? data_blocks : 1; 659 if (ind_blocks || data_blocks) 660 rblocks += RES_STATFS + RES_QUOTA; 661 if (&ip->i_inode == sdp->sd_rindex) 662 rblocks += 2 * RES_STATFS; 663 if (alloc_required) 664 rblocks += gfs2_rg_blocks(ip); 665 666 error = gfs2_trans_begin(sdp, rblocks, 667 PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize); 668 if (error) 669 goto out_trans_fail; 670 671 error = -ENOMEM; 672 flags |= AOP_FLAG_NOFS; 673 page = grab_cache_page_write_begin(mapping, index, flags); 674 *pagep = page; 675 if (unlikely(!page)) 676 goto out_endtrans; 677 678 if (gfs2_is_stuffed(ip)) { 679 error = 0; 680 if (pos + len > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) { 681 error = gfs2_unstuff_dinode(ip, page); 682 if (error == 0) 683 goto prepare_write; 684 } else if (!PageUptodate(page)) { 685 error = stuffed_readpage(ip, page); 686 } 687 goto out; 688 } 689 690 prepare_write: 691 error = __block_write_begin(page, from, len, gfs2_block_map); 692 out: 693 if (error == 0) 694 return 0; 695 696 unlock_page(page); 697 page_cache_release(page); 698 699 gfs2_trans_end(sdp); 700 if (pos + len > ip->i_inode.i_size) 701 gfs2_trim_blocks(&ip->i_inode); 702 goto out_trans_fail; 703 704 out_endtrans: 705 gfs2_trans_end(sdp); 706 out_trans_fail: 707 if (alloc_required) { 708 gfs2_inplace_release(ip); 709 out_qunlock: 710 gfs2_quota_unlock(ip); 711 out_alloc_put: 712 gfs2_qadata_put(ip); 713 } 714 out_unlock: 715 if (&ip->i_inode == sdp->sd_rindex) { 716 gfs2_glock_dq(&m_ip->i_gh); 717 gfs2_holder_uninit(&m_ip->i_gh); 718 } 719 gfs2_glock_dq(&ip->i_gh); 720 out_uninit: 721 gfs2_holder_uninit(&ip->i_gh); 722 return error; 723 } 724 725 /** 726 * adjust_fs_space - Adjusts the free space available due to gfs2_grow 727 * @inode: the rindex inode 728 */ 729 static void adjust_fs_space(struct inode *inode) 730 { 731 struct gfs2_sbd *sdp = inode->i_sb->s_fs_info; 732 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); 733 struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode); 734 struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master; 735 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local; 736 struct buffer_head *m_bh, *l_bh; 737 u64 fs_total, new_free; 738 739 /* Total up the file system space, according to the latest rindex. */ 740 fs_total = gfs2_ri_total(sdp); 741 if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0) 742 return; 743 744 spin_lock(&sdp->sd_statfs_spin); 745 gfs2_statfs_change_in(m_sc, m_bh->b_data + 746 sizeof(struct gfs2_dinode)); 747 if (fs_total > (m_sc->sc_total + l_sc->sc_total)) 748 new_free = fs_total - (m_sc->sc_total + l_sc->sc_total); 749 else 750 new_free = 0; 751 spin_unlock(&sdp->sd_statfs_spin); 752 fs_warn(sdp, "File system extended by %llu blocks.\n", 753 (unsigned long long)new_free); 754 gfs2_statfs_change(sdp, new_free, new_free, 0); 755 756 if (gfs2_meta_inode_buffer(l_ip, &l_bh) != 0) 757 goto out; 758 update_statfs(sdp, m_bh, l_bh); 759 brelse(l_bh); 760 out: 761 brelse(m_bh); 762 } 763 764 /** 765 * gfs2_stuffed_write_end - Write end for stuffed files 766 * @inode: The inode 767 * @dibh: The buffer_head containing the on-disk inode 768 * @pos: The file position 769 * @len: The length of the write 770 * @copied: How much was actually copied by the VFS 771 * @page: The page 772 * 773 * This copies the data from the page into the inode block after 774 * the inode data structure itself. 775 * 776 * Returns: errno 777 */ 778 static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh, 779 loff_t pos, unsigned len, unsigned copied, 780 struct page *page) 781 { 782 struct gfs2_inode *ip = GFS2_I(inode); 783 struct gfs2_sbd *sdp = GFS2_SB(inode); 784 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); 785 u64 to = pos + copied; 786 void *kaddr; 787 unsigned char *buf = dibh->b_data + sizeof(struct gfs2_dinode); 788 789 BUG_ON((pos + len) > (dibh->b_size - sizeof(struct gfs2_dinode))); 790 kaddr = kmap_atomic(page); 791 memcpy(buf + pos, kaddr + pos, copied); 792 memset(kaddr + pos + copied, 0, len - copied); 793 flush_dcache_page(page); 794 kunmap_atomic(kaddr); 795 796 if (!PageUptodate(page)) 797 SetPageUptodate(page); 798 unlock_page(page); 799 page_cache_release(page); 800 801 if (copied) { 802 if (inode->i_size < to) 803 i_size_write(inode, to); 804 mark_inode_dirty(inode); 805 } 806 807 if (inode == sdp->sd_rindex) { 808 adjust_fs_space(inode); 809 sdp->sd_rindex_uptodate = 0; 810 } 811 812 brelse(dibh); 813 gfs2_trans_end(sdp); 814 if (inode == sdp->sd_rindex) { 815 gfs2_glock_dq(&m_ip->i_gh); 816 gfs2_holder_uninit(&m_ip->i_gh); 817 } 818 gfs2_glock_dq(&ip->i_gh); 819 gfs2_holder_uninit(&ip->i_gh); 820 return copied; 821 } 822 823 /** 824 * gfs2_write_end 825 * @file: The file to write to 826 * @mapping: The address space to write to 827 * @pos: The file position 828 * @len: The length of the data 829 * @copied: 830 * @page: The page that has been written 831 * @fsdata: The fsdata (unused in GFS2) 832 * 833 * The main write_end function for GFS2. We have a separate one for 834 * stuffed files as they are slightly different, otherwise we just 835 * put our locking around the VFS provided functions. 836 * 837 * Returns: errno 838 */ 839 840 static int gfs2_write_end(struct file *file, struct address_space *mapping, 841 loff_t pos, unsigned len, unsigned copied, 842 struct page *page, void *fsdata) 843 { 844 struct inode *inode = page->mapping->host; 845 struct gfs2_inode *ip = GFS2_I(inode); 846 struct gfs2_sbd *sdp = GFS2_SB(inode); 847 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); 848 struct buffer_head *dibh; 849 struct gfs2_qadata *qa = ip->i_qadata; 850 unsigned int from = pos & (PAGE_CACHE_SIZE - 1); 851 unsigned int to = from + len; 852 int ret; 853 854 BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == NULL); 855 856 ret = gfs2_meta_inode_buffer(ip, &dibh); 857 if (unlikely(ret)) { 858 unlock_page(page); 859 page_cache_release(page); 860 goto failed; 861 } 862 863 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 864 865 if (gfs2_is_stuffed(ip)) 866 return gfs2_stuffed_write_end(inode, dibh, pos, len, copied, page); 867 868 if (!gfs2_is_writeback(ip)) 869 gfs2_page_add_databufs(ip, page, from, to); 870 871 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); 872 873 if (inode == sdp->sd_rindex) { 874 adjust_fs_space(inode); 875 sdp->sd_rindex_uptodate = 0; 876 } 877 878 brelse(dibh); 879 failed: 880 gfs2_trans_end(sdp); 881 if (ip->i_res) 882 gfs2_inplace_release(ip); 883 if (qa) { 884 gfs2_quota_unlock(ip); 885 gfs2_qadata_put(ip); 886 } 887 if (inode == sdp->sd_rindex) { 888 gfs2_glock_dq(&m_ip->i_gh); 889 gfs2_holder_uninit(&m_ip->i_gh); 890 } 891 gfs2_glock_dq(&ip->i_gh); 892 gfs2_holder_uninit(&ip->i_gh); 893 return ret; 894 } 895 896 /** 897 * gfs2_set_page_dirty - Page dirtying function 898 * @page: The page to dirty 899 * 900 * Returns: 1 if it dirtyed the page, or 0 otherwise 901 */ 902 903 static int gfs2_set_page_dirty(struct page *page) 904 { 905 SetPageChecked(page); 906 return __set_page_dirty_buffers(page); 907 } 908 909 /** 910 * gfs2_bmap - Block map function 911 * @mapping: Address space info 912 * @lblock: The block to map 913 * 914 * Returns: The disk address for the block or 0 on hole or error 915 */ 916 917 static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock) 918 { 919 struct gfs2_inode *ip = GFS2_I(mapping->host); 920 struct gfs2_holder i_gh; 921 sector_t dblock = 0; 922 int error; 923 924 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh); 925 if (error) 926 return 0; 927 928 if (!gfs2_is_stuffed(ip)) 929 dblock = generic_block_bmap(mapping, lblock, gfs2_block_map); 930 931 gfs2_glock_dq_uninit(&i_gh); 932 933 return dblock; 934 } 935 936 static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh) 937 { 938 struct gfs2_bufdata *bd; 939 940 lock_buffer(bh); 941 gfs2_log_lock(sdp); 942 clear_buffer_dirty(bh); 943 bd = bh->b_private; 944 if (bd) { 945 if (!list_empty(&bd->bd_list) && !buffer_pinned(bh)) 946 list_del_init(&bd->bd_list); 947 else 948 gfs2_remove_from_journal(bh, current->journal_info, 0); 949 } 950 bh->b_bdev = NULL; 951 clear_buffer_mapped(bh); 952 clear_buffer_req(bh); 953 clear_buffer_new(bh); 954 gfs2_log_unlock(sdp); 955 unlock_buffer(bh); 956 } 957 958 static void gfs2_invalidatepage(struct page *page, unsigned long offset) 959 { 960 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host); 961 struct buffer_head *bh, *head; 962 unsigned long pos = 0; 963 964 BUG_ON(!PageLocked(page)); 965 if (offset == 0) 966 ClearPageChecked(page); 967 if (!page_has_buffers(page)) 968 goto out; 969 970 bh = head = page_buffers(page); 971 do { 972 if (offset <= pos) 973 gfs2_discard(sdp, bh); 974 pos += bh->b_size; 975 bh = bh->b_this_page; 976 } while (bh != head); 977 out: 978 if (offset == 0) 979 try_to_release_page(page, 0); 980 } 981 982 /** 983 * gfs2_ok_for_dio - check that dio is valid on this file 984 * @ip: The inode 985 * @rw: READ or WRITE 986 * @offset: The offset at which we are reading or writing 987 * 988 * Returns: 0 (to ignore the i/o request and thus fall back to buffered i/o) 989 * 1 (to accept the i/o request) 990 */ 991 static int gfs2_ok_for_dio(struct gfs2_inode *ip, int rw, loff_t offset) 992 { 993 /* 994 * Should we return an error here? I can't see that O_DIRECT for 995 * a stuffed file makes any sense. For now we'll silently fall 996 * back to buffered I/O 997 */ 998 if (gfs2_is_stuffed(ip)) 999 return 0; 1000 1001 if (offset >= i_size_read(&ip->i_inode)) 1002 return 0; 1003 return 1; 1004 } 1005 1006 1007 1008 static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb, 1009 const struct iovec *iov, loff_t offset, 1010 unsigned long nr_segs) 1011 { 1012 struct file *file = iocb->ki_filp; 1013 struct inode *inode = file->f_mapping->host; 1014 struct gfs2_inode *ip = GFS2_I(inode); 1015 struct gfs2_holder gh; 1016 int rv; 1017 1018 /* 1019 * Deferred lock, even if its a write, since we do no allocation 1020 * on this path. All we need change is atime, and this lock mode 1021 * ensures that other nodes have flushed their buffered read caches 1022 * (i.e. their page cache entries for this inode). We do not, 1023 * unfortunately have the option of only flushing a range like 1024 * the VFS does. 1025 */ 1026 gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, &gh); 1027 rv = gfs2_glock_nq(&gh); 1028 if (rv) 1029 return rv; 1030 rv = gfs2_ok_for_dio(ip, rw, offset); 1031 if (rv != 1) 1032 goto out; /* dio not valid, fall back to buffered i/o */ 1033 1034 rv = __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, 1035 offset, nr_segs, gfs2_get_block_direct, 1036 NULL, NULL, 0); 1037 out: 1038 gfs2_glock_dq_m(1, &gh); 1039 gfs2_holder_uninit(&gh); 1040 return rv; 1041 } 1042 1043 /** 1044 * gfs2_releasepage - free the metadata associated with a page 1045 * @page: the page that's being released 1046 * @gfp_mask: passed from Linux VFS, ignored by us 1047 * 1048 * Call try_to_free_buffers() if the buffers in this page can be 1049 * released. 1050 * 1051 * Returns: 0 1052 */ 1053 1054 int gfs2_releasepage(struct page *page, gfp_t gfp_mask) 1055 { 1056 struct address_space *mapping = page->mapping; 1057 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping); 1058 struct buffer_head *bh, *head; 1059 struct gfs2_bufdata *bd; 1060 1061 if (!page_has_buffers(page)) 1062 return 0; 1063 1064 gfs2_log_lock(sdp); 1065 spin_lock(&sdp->sd_ail_lock); 1066 head = bh = page_buffers(page); 1067 do { 1068 if (atomic_read(&bh->b_count)) 1069 goto cannot_release; 1070 bd = bh->b_private; 1071 if (bd && bd->bd_ail) 1072 goto cannot_release; 1073 if (buffer_pinned(bh) || buffer_dirty(bh)) 1074 goto not_possible; 1075 bh = bh->b_this_page; 1076 } while(bh != head); 1077 spin_unlock(&sdp->sd_ail_lock); 1078 gfs2_log_unlock(sdp); 1079 1080 head = bh = page_buffers(page); 1081 do { 1082 gfs2_log_lock(sdp); 1083 bd = bh->b_private; 1084 if (bd) { 1085 gfs2_assert_warn(sdp, bd->bd_bh == bh); 1086 if (!list_empty(&bd->bd_list)) { 1087 if (!buffer_pinned(bh)) 1088 list_del_init(&bd->bd_list); 1089 else 1090 bd = NULL; 1091 } 1092 if (bd) 1093 bd->bd_bh = NULL; 1094 bh->b_private = NULL; 1095 } 1096 gfs2_log_unlock(sdp); 1097 if (bd) 1098 kmem_cache_free(gfs2_bufdata_cachep, bd); 1099 1100 bh = bh->b_this_page; 1101 } while (bh != head); 1102 1103 return try_to_free_buffers(page); 1104 1105 not_possible: /* Should never happen */ 1106 WARN_ON(buffer_dirty(bh)); 1107 WARN_ON(buffer_pinned(bh)); 1108 cannot_release: 1109 spin_unlock(&sdp->sd_ail_lock); 1110 gfs2_log_unlock(sdp); 1111 return 0; 1112 } 1113 1114 static const struct address_space_operations gfs2_writeback_aops = { 1115 .writepage = gfs2_writeback_writepage, 1116 .writepages = gfs2_writeback_writepages, 1117 .readpage = gfs2_readpage, 1118 .readpages = gfs2_readpages, 1119 .write_begin = gfs2_write_begin, 1120 .write_end = gfs2_write_end, 1121 .bmap = gfs2_bmap, 1122 .invalidatepage = gfs2_invalidatepage, 1123 .releasepage = gfs2_releasepage, 1124 .direct_IO = gfs2_direct_IO, 1125 .migratepage = buffer_migrate_page, 1126 .is_partially_uptodate = block_is_partially_uptodate, 1127 .error_remove_page = generic_error_remove_page, 1128 }; 1129 1130 static const struct address_space_operations gfs2_ordered_aops = { 1131 .writepage = gfs2_ordered_writepage, 1132 .readpage = gfs2_readpage, 1133 .readpages = gfs2_readpages, 1134 .write_begin = gfs2_write_begin, 1135 .write_end = gfs2_write_end, 1136 .set_page_dirty = gfs2_set_page_dirty, 1137 .bmap = gfs2_bmap, 1138 .invalidatepage = gfs2_invalidatepage, 1139 .releasepage = gfs2_releasepage, 1140 .direct_IO = gfs2_direct_IO, 1141 .migratepage = buffer_migrate_page, 1142 .is_partially_uptodate = block_is_partially_uptodate, 1143 .error_remove_page = generic_error_remove_page, 1144 }; 1145 1146 static const struct address_space_operations gfs2_jdata_aops = { 1147 .writepage = gfs2_jdata_writepage, 1148 .writepages = gfs2_jdata_writepages, 1149 .readpage = gfs2_readpage, 1150 .readpages = gfs2_readpages, 1151 .write_begin = gfs2_write_begin, 1152 .write_end = gfs2_write_end, 1153 .set_page_dirty = gfs2_set_page_dirty, 1154 .bmap = gfs2_bmap, 1155 .invalidatepage = gfs2_invalidatepage, 1156 .releasepage = gfs2_releasepage, 1157 .is_partially_uptodate = block_is_partially_uptodate, 1158 .error_remove_page = generic_error_remove_page, 1159 }; 1160 1161 void gfs2_set_aops(struct inode *inode) 1162 { 1163 struct gfs2_inode *ip = GFS2_I(inode); 1164 1165 if (gfs2_is_writeback(ip)) 1166 inode->i_mapping->a_ops = &gfs2_writeback_aops; 1167 else if (gfs2_is_ordered(ip)) 1168 inode->i_mapping->a_ops = &gfs2_ordered_aops; 1169 else if (gfs2_is_jdata(ip)) 1170 inode->i_mapping->a_ops = &gfs2_jdata_aops; 1171 else 1172 BUG(); 1173 } 1174 1175