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 #include <linux/aio.h> 24 25 #include "gfs2.h" 26 #include "incore.h" 27 #include "bmap.h" 28 #include "glock.h" 29 #include "inode.h" 30 #include "log.h" 31 #include "meta_io.h" 32 #include "quota.h" 33 #include "trans.h" 34 #include "rgrp.h" 35 #include "super.h" 36 #include "util.h" 37 #include "glops.h" 38 39 40 static void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page, 41 unsigned int from, unsigned int to) 42 { 43 struct buffer_head *head = page_buffers(page); 44 unsigned int bsize = head->b_size; 45 struct buffer_head *bh; 46 unsigned int start, end; 47 48 for (bh = head, start = 0; bh != head || !start; 49 bh = bh->b_this_page, start = end) { 50 end = start + bsize; 51 if (end <= from || start >= to) 52 continue; 53 if (gfs2_is_jdata(ip)) 54 set_buffer_uptodate(bh); 55 gfs2_trans_add_data(ip->i_gl, bh); 56 } 57 } 58 59 /** 60 * gfs2_get_block_noalloc - Fills in a buffer head with details about a block 61 * @inode: The inode 62 * @lblock: The block number to look up 63 * @bh_result: The buffer head to return the result in 64 * @create: Non-zero if we may add block to the file 65 * 66 * Returns: errno 67 */ 68 69 static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock, 70 struct buffer_head *bh_result, int create) 71 { 72 int error; 73 74 error = gfs2_block_map(inode, lblock, bh_result, 0); 75 if (error) 76 return error; 77 if (!buffer_mapped(bh_result)) 78 return -EIO; 79 return 0; 80 } 81 82 static int gfs2_get_block_direct(struct inode *inode, sector_t lblock, 83 struct buffer_head *bh_result, int create) 84 { 85 return gfs2_block_map(inode, lblock, bh_result, 0); 86 } 87 88 /** 89 * gfs2_writepage_common - Common bits of writepage 90 * @page: The page to be written 91 * @wbc: The writeback control 92 * 93 * Returns: 1 if writepage is ok, otherwise an error code or zero if no error. 94 */ 95 96 static int gfs2_writepage_common(struct page *page, 97 struct writeback_control *wbc) 98 { 99 struct inode *inode = page->mapping->host; 100 struct gfs2_inode *ip = GFS2_I(inode); 101 struct gfs2_sbd *sdp = GFS2_SB(inode); 102 loff_t i_size = i_size_read(inode); 103 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT; 104 unsigned offset; 105 106 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) 107 goto out; 108 if (current->journal_info) 109 goto redirty; 110 /* Is the page fully outside i_size? (truncate in progress) */ 111 offset = i_size & (PAGE_CACHE_SIZE-1); 112 if (page->index > end_index || (page->index == end_index && !offset)) { 113 page->mapping->a_ops->invalidatepage(page, 0, PAGE_CACHE_SIZE); 114 goto out; 115 } 116 return 1; 117 redirty: 118 redirty_page_for_writepage(wbc, page); 119 out: 120 unlock_page(page); 121 return 0; 122 } 123 124 /** 125 * gfs2_writepage - Write page for writeback mappings 126 * @page: The page 127 * @wbc: The writeback control 128 * 129 */ 130 131 static int gfs2_writepage(struct page *page, 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_jdata_writepage - The core of jdata writepage 144 * @page: The page to write 145 * @wbc: The writeback control 146 * 147 * This is shared between writepage and writepages and implements the 148 * core of the writepage operation. If a transaction is required then 149 * PageChecked will have been set and the transaction will have 150 * already been started before this is called. 151 */ 152 153 static int __gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc) 154 { 155 struct inode *inode = page->mapping->host; 156 struct gfs2_inode *ip = GFS2_I(inode); 157 struct gfs2_sbd *sdp = GFS2_SB(inode); 158 159 if (PageChecked(page)) { 160 ClearPageChecked(page); 161 if (!page_has_buffers(page)) { 162 create_empty_buffers(page, inode->i_sb->s_blocksize, 163 (1 << BH_Dirty)|(1 << BH_Uptodate)); 164 } 165 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1); 166 } 167 return block_write_full_page(page, gfs2_get_block_noalloc, wbc); 168 } 169 170 /** 171 * gfs2_jdata_writepage - Write complete page 172 * @page: Page to write 173 * 174 * Returns: errno 175 * 176 */ 177 178 static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc) 179 { 180 struct inode *inode = page->mapping->host; 181 struct gfs2_sbd *sdp = GFS2_SB(inode); 182 int ret; 183 int done_trans = 0; 184 185 if (PageChecked(page)) { 186 if (wbc->sync_mode != WB_SYNC_ALL) 187 goto out_ignore; 188 ret = gfs2_trans_begin(sdp, RES_DINODE + 1, 0); 189 if (ret) 190 goto out_ignore; 191 done_trans = 1; 192 } 193 ret = gfs2_writepage_common(page, wbc); 194 if (ret > 0) 195 ret = __gfs2_jdata_writepage(page, wbc); 196 if (done_trans) 197 gfs2_trans_end(sdp); 198 return ret; 199 200 out_ignore: 201 redirty_page_for_writepage(wbc, page); 202 unlock_page(page); 203 return 0; 204 } 205 206 /** 207 * gfs2_writepages - Write a bunch of dirty pages back to disk 208 * @mapping: The mapping to write 209 * @wbc: Write-back control 210 * 211 * Used for both ordered and writeback modes. 212 */ 213 static int gfs2_writepages(struct address_space *mapping, 214 struct writeback_control *wbc) 215 { 216 return mpage_writepages(mapping, wbc, gfs2_get_block_noalloc); 217 } 218 219 /** 220 * gfs2_write_jdata_pagevec - Write back a pagevec's worth of pages 221 * @mapping: The mapping 222 * @wbc: The writeback control 223 * @writepage: The writepage function to call for each page 224 * @pvec: The vector of pages 225 * @nr_pages: The number of pages to write 226 * 227 * Returns: non-zero if loop should terminate, zero otherwise 228 */ 229 230 static int gfs2_write_jdata_pagevec(struct address_space *mapping, 231 struct writeback_control *wbc, 232 struct pagevec *pvec, 233 int nr_pages, pgoff_t end) 234 { 235 struct inode *inode = mapping->host; 236 struct gfs2_sbd *sdp = GFS2_SB(inode); 237 loff_t i_size = i_size_read(inode); 238 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT; 239 unsigned offset = i_size & (PAGE_CACHE_SIZE-1); 240 unsigned nrblocks = nr_pages * (PAGE_CACHE_SIZE/inode->i_sb->s_blocksize); 241 int i; 242 int ret; 243 244 ret = gfs2_trans_begin(sdp, nrblocks, nrblocks); 245 if (ret < 0) 246 return ret; 247 248 for(i = 0; i < nr_pages; i++) { 249 struct page *page = pvec->pages[i]; 250 251 lock_page(page); 252 253 if (unlikely(page->mapping != mapping)) { 254 unlock_page(page); 255 continue; 256 } 257 258 if (!wbc->range_cyclic && page->index > end) { 259 ret = 1; 260 unlock_page(page); 261 continue; 262 } 263 264 if (wbc->sync_mode != WB_SYNC_NONE) 265 wait_on_page_writeback(page); 266 267 if (PageWriteback(page) || 268 !clear_page_dirty_for_io(page)) { 269 unlock_page(page); 270 continue; 271 } 272 273 /* Is the page fully outside i_size? (truncate in progress) */ 274 if (page->index > end_index || (page->index == end_index && !offset)) { 275 page->mapping->a_ops->invalidatepage(page, 0, 276 PAGE_CACHE_SIZE); 277 unlock_page(page); 278 continue; 279 } 280 281 ret = __gfs2_jdata_writepage(page, wbc); 282 283 if (ret || (--(wbc->nr_to_write) <= 0)) 284 ret = 1; 285 } 286 gfs2_trans_end(sdp); 287 return ret; 288 } 289 290 /** 291 * gfs2_write_cache_jdata - Like write_cache_pages but different 292 * @mapping: The mapping to write 293 * @wbc: The writeback control 294 * @writepage: The writepage function to call 295 * @data: The data to pass to writepage 296 * 297 * The reason that we use our own function here is that we need to 298 * start transactions before we grab page locks. This allows us 299 * to get the ordering right. 300 */ 301 302 static int gfs2_write_cache_jdata(struct address_space *mapping, 303 struct writeback_control *wbc) 304 { 305 int ret = 0; 306 int done = 0; 307 struct pagevec pvec; 308 int nr_pages; 309 pgoff_t index; 310 pgoff_t end; 311 int scanned = 0; 312 int range_whole = 0; 313 314 pagevec_init(&pvec, 0); 315 if (wbc->range_cyclic) { 316 index = mapping->writeback_index; /* Start from prev offset */ 317 end = -1; 318 } else { 319 index = wbc->range_start >> PAGE_CACHE_SHIFT; 320 end = wbc->range_end >> PAGE_CACHE_SHIFT; 321 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) 322 range_whole = 1; 323 scanned = 1; 324 } 325 326 retry: 327 while (!done && (index <= end) && 328 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, 329 PAGECACHE_TAG_DIRTY, 330 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) { 331 scanned = 1; 332 ret = gfs2_write_jdata_pagevec(mapping, wbc, &pvec, nr_pages, end); 333 if (ret) 334 done = 1; 335 if (ret > 0) 336 ret = 0; 337 338 pagevec_release(&pvec); 339 cond_resched(); 340 } 341 342 if (!scanned && !done) { 343 /* 344 * We hit the last page and there is more work to be done: wrap 345 * back to the start of the file 346 */ 347 scanned = 1; 348 index = 0; 349 goto retry; 350 } 351 352 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) 353 mapping->writeback_index = index; 354 return ret; 355 } 356 357 358 /** 359 * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk 360 * @mapping: The mapping to write 361 * @wbc: The writeback control 362 * 363 */ 364 365 static int gfs2_jdata_writepages(struct address_space *mapping, 366 struct writeback_control *wbc) 367 { 368 struct gfs2_inode *ip = GFS2_I(mapping->host); 369 struct gfs2_sbd *sdp = GFS2_SB(mapping->host); 370 int ret; 371 372 ret = gfs2_write_cache_jdata(mapping, wbc); 373 if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) { 374 gfs2_log_flush(sdp, ip->i_gl); 375 ret = gfs2_write_cache_jdata(mapping, wbc); 376 } 377 return ret; 378 } 379 380 /** 381 * stuffed_readpage - Fill in a Linux page with stuffed file data 382 * @ip: the inode 383 * @page: the page 384 * 385 * Returns: errno 386 */ 387 388 static int stuffed_readpage(struct gfs2_inode *ip, struct page *page) 389 { 390 struct buffer_head *dibh; 391 u64 dsize = i_size_read(&ip->i_inode); 392 void *kaddr; 393 int error; 394 395 /* 396 * Due to the order of unstuffing files and ->fault(), we can be 397 * asked for a zero page in the case of a stuffed file being extended, 398 * so we need to supply one here. It doesn't happen often. 399 */ 400 if (unlikely(page->index)) { 401 zero_user(page, 0, PAGE_CACHE_SIZE); 402 SetPageUptodate(page); 403 return 0; 404 } 405 406 error = gfs2_meta_inode_buffer(ip, &dibh); 407 if (error) 408 return error; 409 410 kaddr = kmap_atomic(page); 411 if (dsize > (dibh->b_size - sizeof(struct gfs2_dinode))) 412 dsize = (dibh->b_size - sizeof(struct gfs2_dinode)); 413 memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize); 414 memset(kaddr + dsize, 0, PAGE_CACHE_SIZE - dsize); 415 kunmap_atomic(kaddr); 416 flush_dcache_page(page); 417 brelse(dibh); 418 SetPageUptodate(page); 419 420 return 0; 421 } 422 423 424 /** 425 * __gfs2_readpage - readpage 426 * @file: The file to read a page for 427 * @page: The page to read 428 * 429 * This is the core of gfs2's readpage. Its used by the internal file 430 * reading code as in that case we already hold the glock. Also its 431 * called by gfs2_readpage() once the required lock has been granted. 432 * 433 */ 434 435 static int __gfs2_readpage(void *file, struct page *page) 436 { 437 struct gfs2_inode *ip = GFS2_I(page->mapping->host); 438 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host); 439 int error; 440 441 if (gfs2_is_stuffed(ip)) { 442 error = stuffed_readpage(ip, page); 443 unlock_page(page); 444 } else { 445 error = mpage_readpage(page, gfs2_block_map); 446 } 447 448 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) 449 return -EIO; 450 451 return error; 452 } 453 454 /** 455 * gfs2_readpage - read a page of a file 456 * @file: The file to read 457 * @page: The page of the file 458 * 459 * This deals with the locking required. We have to unlock and 460 * relock the page in order to get the locking in the right 461 * order. 462 */ 463 464 static int gfs2_readpage(struct file *file, struct page *page) 465 { 466 struct address_space *mapping = page->mapping; 467 struct gfs2_inode *ip = GFS2_I(mapping->host); 468 struct gfs2_holder gh; 469 int error; 470 471 unlock_page(page); 472 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh); 473 error = gfs2_glock_nq(&gh); 474 if (unlikely(error)) 475 goto out; 476 error = AOP_TRUNCATED_PAGE; 477 lock_page(page); 478 if (page->mapping == mapping && !PageUptodate(page)) 479 error = __gfs2_readpage(file, page); 480 else 481 unlock_page(page); 482 gfs2_glock_dq(&gh); 483 out: 484 gfs2_holder_uninit(&gh); 485 if (error && error != AOP_TRUNCATED_PAGE) 486 lock_page(page); 487 return error; 488 } 489 490 /** 491 * gfs2_internal_read - read an internal file 492 * @ip: The gfs2 inode 493 * @buf: The buffer to fill 494 * @pos: The file position 495 * @size: The amount to read 496 * 497 */ 498 499 int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos, 500 unsigned size) 501 { 502 struct address_space *mapping = ip->i_inode.i_mapping; 503 unsigned long index = *pos / PAGE_CACHE_SIZE; 504 unsigned offset = *pos & (PAGE_CACHE_SIZE - 1); 505 unsigned copied = 0; 506 unsigned amt; 507 struct page *page; 508 void *p; 509 510 do { 511 amt = size - copied; 512 if (offset + size > PAGE_CACHE_SIZE) 513 amt = PAGE_CACHE_SIZE - offset; 514 page = read_cache_page(mapping, index, __gfs2_readpage, NULL); 515 if (IS_ERR(page)) 516 return PTR_ERR(page); 517 p = kmap_atomic(page); 518 memcpy(buf + copied, p + offset, amt); 519 kunmap_atomic(p); 520 mark_page_accessed(page); 521 page_cache_release(page); 522 copied += amt; 523 index++; 524 offset = 0; 525 } while(copied < size); 526 (*pos) += size; 527 return size; 528 } 529 530 /** 531 * gfs2_readpages - Read a bunch of pages at once 532 * 533 * Some notes: 534 * 1. This is only for readahead, so we can simply ignore any things 535 * which are slightly inconvenient (such as locking conflicts between 536 * the page lock and the glock) and return having done no I/O. Its 537 * obviously not something we'd want to do on too regular a basis. 538 * Any I/O we ignore at this time will be done via readpage later. 539 * 2. We don't handle stuffed files here we let readpage do the honours. 540 * 3. mpage_readpages() does most of the heavy lifting in the common case. 541 * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places. 542 */ 543 544 static int gfs2_readpages(struct file *file, struct address_space *mapping, 545 struct list_head *pages, unsigned nr_pages) 546 { 547 struct inode *inode = mapping->host; 548 struct gfs2_inode *ip = GFS2_I(inode); 549 struct gfs2_sbd *sdp = GFS2_SB(inode); 550 struct gfs2_holder gh; 551 int ret; 552 553 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh); 554 ret = gfs2_glock_nq(&gh); 555 if (unlikely(ret)) 556 goto out_uninit; 557 if (!gfs2_is_stuffed(ip)) 558 ret = mpage_readpages(mapping, pages, nr_pages, gfs2_block_map); 559 gfs2_glock_dq(&gh); 560 out_uninit: 561 gfs2_holder_uninit(&gh); 562 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) 563 ret = -EIO; 564 return ret; 565 } 566 567 /** 568 * gfs2_write_begin - Begin to write to a file 569 * @file: The file to write to 570 * @mapping: The mapping in which to write 571 * @pos: The file offset at which to start writing 572 * @len: Length of the write 573 * @flags: Various flags 574 * @pagep: Pointer to return the page 575 * @fsdata: Pointer to return fs data (unused by GFS2) 576 * 577 * Returns: errno 578 */ 579 580 static int gfs2_write_begin(struct file *file, struct address_space *mapping, 581 loff_t pos, unsigned len, unsigned flags, 582 struct page **pagep, void **fsdata) 583 { 584 struct gfs2_inode *ip = GFS2_I(mapping->host); 585 struct gfs2_sbd *sdp = GFS2_SB(mapping->host); 586 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); 587 unsigned int data_blocks = 0, ind_blocks = 0, rblocks; 588 unsigned requested = 0; 589 int alloc_required; 590 int error = 0; 591 pgoff_t index = pos >> PAGE_CACHE_SHIFT; 592 unsigned from = pos & (PAGE_CACHE_SIZE - 1); 593 struct page *page; 594 595 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh); 596 error = gfs2_glock_nq(&ip->i_gh); 597 if (unlikely(error)) 598 goto out_uninit; 599 if (&ip->i_inode == sdp->sd_rindex) { 600 error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, 601 GL_NOCACHE, &m_ip->i_gh); 602 if (unlikely(error)) { 603 gfs2_glock_dq(&ip->i_gh); 604 goto out_uninit; 605 } 606 } 607 608 alloc_required = gfs2_write_alloc_required(ip, pos, len); 609 610 if (alloc_required || gfs2_is_jdata(ip)) 611 gfs2_write_calc_reserv(ip, len, &data_blocks, &ind_blocks); 612 613 if (alloc_required) { 614 error = gfs2_quota_lock_check(ip); 615 if (error) 616 goto out_unlock; 617 618 requested = data_blocks + ind_blocks; 619 error = gfs2_inplace_reserve(ip, requested, 0); 620 if (error) 621 goto out_qunlock; 622 } 623 624 rblocks = RES_DINODE + ind_blocks; 625 if (gfs2_is_jdata(ip)) 626 rblocks += data_blocks ? data_blocks : 1; 627 if (ind_blocks || data_blocks) 628 rblocks += RES_STATFS + RES_QUOTA; 629 if (&ip->i_inode == sdp->sd_rindex) 630 rblocks += 2 * RES_STATFS; 631 if (alloc_required) 632 rblocks += gfs2_rg_blocks(ip, requested); 633 634 error = gfs2_trans_begin(sdp, rblocks, 635 PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize); 636 if (error) 637 goto out_trans_fail; 638 639 error = -ENOMEM; 640 flags |= AOP_FLAG_NOFS; 641 page = grab_cache_page_write_begin(mapping, index, flags); 642 *pagep = page; 643 if (unlikely(!page)) 644 goto out_endtrans; 645 646 if (gfs2_is_stuffed(ip)) { 647 error = 0; 648 if (pos + len > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) { 649 error = gfs2_unstuff_dinode(ip, page); 650 if (error == 0) 651 goto prepare_write; 652 } else if (!PageUptodate(page)) { 653 error = stuffed_readpage(ip, page); 654 } 655 goto out; 656 } 657 658 prepare_write: 659 error = __block_write_begin(page, from, len, gfs2_block_map); 660 out: 661 if (error == 0) 662 return 0; 663 664 unlock_page(page); 665 page_cache_release(page); 666 667 gfs2_trans_end(sdp); 668 if (pos + len > ip->i_inode.i_size) 669 gfs2_trim_blocks(&ip->i_inode); 670 goto out_trans_fail; 671 672 out_endtrans: 673 gfs2_trans_end(sdp); 674 out_trans_fail: 675 if (alloc_required) { 676 gfs2_inplace_release(ip); 677 out_qunlock: 678 gfs2_quota_unlock(ip); 679 } 680 out_unlock: 681 if (&ip->i_inode == sdp->sd_rindex) { 682 gfs2_glock_dq(&m_ip->i_gh); 683 gfs2_holder_uninit(&m_ip->i_gh); 684 } 685 gfs2_glock_dq(&ip->i_gh); 686 out_uninit: 687 gfs2_holder_uninit(&ip->i_gh); 688 return error; 689 } 690 691 /** 692 * adjust_fs_space - Adjusts the free space available due to gfs2_grow 693 * @inode: the rindex inode 694 */ 695 static void adjust_fs_space(struct inode *inode) 696 { 697 struct gfs2_sbd *sdp = inode->i_sb->s_fs_info; 698 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); 699 struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode); 700 struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master; 701 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local; 702 struct buffer_head *m_bh, *l_bh; 703 u64 fs_total, new_free; 704 705 /* Total up the file system space, according to the latest rindex. */ 706 fs_total = gfs2_ri_total(sdp); 707 if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0) 708 return; 709 710 spin_lock(&sdp->sd_statfs_spin); 711 gfs2_statfs_change_in(m_sc, m_bh->b_data + 712 sizeof(struct gfs2_dinode)); 713 if (fs_total > (m_sc->sc_total + l_sc->sc_total)) 714 new_free = fs_total - (m_sc->sc_total + l_sc->sc_total); 715 else 716 new_free = 0; 717 spin_unlock(&sdp->sd_statfs_spin); 718 fs_warn(sdp, "File system extended by %llu blocks.\n", 719 (unsigned long long)new_free); 720 gfs2_statfs_change(sdp, new_free, new_free, 0); 721 722 if (gfs2_meta_inode_buffer(l_ip, &l_bh) != 0) 723 goto out; 724 update_statfs(sdp, m_bh, l_bh); 725 brelse(l_bh); 726 out: 727 brelse(m_bh); 728 } 729 730 /** 731 * gfs2_stuffed_write_end - Write end for stuffed files 732 * @inode: The inode 733 * @dibh: The buffer_head containing the on-disk inode 734 * @pos: The file position 735 * @len: The length of the write 736 * @copied: How much was actually copied by the VFS 737 * @page: The page 738 * 739 * This copies the data from the page into the inode block after 740 * the inode data structure itself. 741 * 742 * Returns: errno 743 */ 744 static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh, 745 loff_t pos, unsigned len, unsigned copied, 746 struct page *page) 747 { 748 struct gfs2_inode *ip = GFS2_I(inode); 749 struct gfs2_sbd *sdp = GFS2_SB(inode); 750 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); 751 u64 to = pos + copied; 752 void *kaddr; 753 unsigned char *buf = dibh->b_data + sizeof(struct gfs2_dinode); 754 755 BUG_ON((pos + len) > (dibh->b_size - sizeof(struct gfs2_dinode))); 756 kaddr = kmap_atomic(page); 757 memcpy(buf + pos, kaddr + pos, copied); 758 memset(kaddr + pos + copied, 0, len - copied); 759 flush_dcache_page(page); 760 kunmap_atomic(kaddr); 761 762 if (!PageUptodate(page)) 763 SetPageUptodate(page); 764 unlock_page(page); 765 page_cache_release(page); 766 767 if (copied) { 768 if (inode->i_size < to) 769 i_size_write(inode, to); 770 mark_inode_dirty(inode); 771 } 772 773 if (inode == sdp->sd_rindex) { 774 adjust_fs_space(inode); 775 sdp->sd_rindex_uptodate = 0; 776 } 777 778 brelse(dibh); 779 gfs2_trans_end(sdp); 780 if (inode == sdp->sd_rindex) { 781 gfs2_glock_dq(&m_ip->i_gh); 782 gfs2_holder_uninit(&m_ip->i_gh); 783 } 784 gfs2_glock_dq(&ip->i_gh); 785 gfs2_holder_uninit(&ip->i_gh); 786 return copied; 787 } 788 789 /** 790 * gfs2_write_end 791 * @file: The file to write to 792 * @mapping: The address space to write to 793 * @pos: The file position 794 * @len: The length of the data 795 * @copied: 796 * @page: The page that has been written 797 * @fsdata: The fsdata (unused in GFS2) 798 * 799 * The main write_end function for GFS2. We have a separate one for 800 * stuffed files as they are slightly different, otherwise we just 801 * put our locking around the VFS provided functions. 802 * 803 * Returns: errno 804 */ 805 806 static int gfs2_write_end(struct file *file, struct address_space *mapping, 807 loff_t pos, unsigned len, unsigned copied, 808 struct page *page, void *fsdata) 809 { 810 struct inode *inode = page->mapping->host; 811 struct gfs2_inode *ip = GFS2_I(inode); 812 struct gfs2_sbd *sdp = GFS2_SB(inode); 813 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); 814 struct buffer_head *dibh; 815 unsigned int from = pos & (PAGE_CACHE_SIZE - 1); 816 unsigned int to = from + len; 817 int ret; 818 819 BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == NULL); 820 821 ret = gfs2_meta_inode_buffer(ip, &dibh); 822 if (unlikely(ret)) { 823 unlock_page(page); 824 page_cache_release(page); 825 goto failed; 826 } 827 828 gfs2_trans_add_meta(ip->i_gl, dibh); 829 830 if (gfs2_is_stuffed(ip)) 831 return gfs2_stuffed_write_end(inode, dibh, pos, len, copied, page); 832 833 if (!gfs2_is_writeback(ip)) 834 gfs2_page_add_databufs(ip, page, from, to); 835 836 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); 837 838 if (inode == sdp->sd_rindex) { 839 adjust_fs_space(inode); 840 sdp->sd_rindex_uptodate = 0; 841 } 842 843 brelse(dibh); 844 failed: 845 gfs2_trans_end(sdp); 846 gfs2_inplace_release(ip); 847 if (ip->i_res->rs_qa_qd_num) 848 gfs2_quota_unlock(ip); 849 if (inode == sdp->sd_rindex) { 850 gfs2_glock_dq(&m_ip->i_gh); 851 gfs2_holder_uninit(&m_ip->i_gh); 852 } 853 gfs2_glock_dq(&ip->i_gh); 854 gfs2_holder_uninit(&ip->i_gh); 855 return ret; 856 } 857 858 /** 859 * gfs2_set_page_dirty - Page dirtying function 860 * @page: The page to dirty 861 * 862 * Returns: 1 if it dirtyed the page, or 0 otherwise 863 */ 864 865 static int gfs2_set_page_dirty(struct page *page) 866 { 867 SetPageChecked(page); 868 return __set_page_dirty_buffers(page); 869 } 870 871 /** 872 * gfs2_bmap - Block map function 873 * @mapping: Address space info 874 * @lblock: The block to map 875 * 876 * Returns: The disk address for the block or 0 on hole or error 877 */ 878 879 static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock) 880 { 881 struct gfs2_inode *ip = GFS2_I(mapping->host); 882 struct gfs2_holder i_gh; 883 sector_t dblock = 0; 884 int error; 885 886 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh); 887 if (error) 888 return 0; 889 890 if (!gfs2_is_stuffed(ip)) 891 dblock = generic_block_bmap(mapping, lblock, gfs2_block_map); 892 893 gfs2_glock_dq_uninit(&i_gh); 894 895 return dblock; 896 } 897 898 static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh) 899 { 900 struct gfs2_bufdata *bd; 901 902 lock_buffer(bh); 903 gfs2_log_lock(sdp); 904 clear_buffer_dirty(bh); 905 bd = bh->b_private; 906 if (bd) { 907 if (!list_empty(&bd->bd_list) && !buffer_pinned(bh)) 908 list_del_init(&bd->bd_list); 909 else 910 gfs2_remove_from_journal(bh, current->journal_info, 0); 911 } 912 bh->b_bdev = NULL; 913 clear_buffer_mapped(bh); 914 clear_buffer_req(bh); 915 clear_buffer_new(bh); 916 gfs2_log_unlock(sdp); 917 unlock_buffer(bh); 918 } 919 920 static void gfs2_invalidatepage(struct page *page, unsigned int offset, 921 unsigned int length) 922 { 923 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host); 924 unsigned int stop = offset + length; 925 int partial_page = (offset || length < PAGE_CACHE_SIZE); 926 struct buffer_head *bh, *head; 927 unsigned long pos = 0; 928 929 BUG_ON(!PageLocked(page)); 930 if (!partial_page) 931 ClearPageChecked(page); 932 if (!page_has_buffers(page)) 933 goto out; 934 935 bh = head = page_buffers(page); 936 do { 937 if (pos + bh->b_size > stop) 938 return; 939 940 if (offset <= pos) 941 gfs2_discard(sdp, bh); 942 pos += bh->b_size; 943 bh = bh->b_this_page; 944 } while (bh != head); 945 out: 946 if (!partial_page) 947 try_to_release_page(page, 0); 948 } 949 950 /** 951 * gfs2_ok_for_dio - check that dio is valid on this file 952 * @ip: The inode 953 * @rw: READ or WRITE 954 * @offset: The offset at which we are reading or writing 955 * 956 * Returns: 0 (to ignore the i/o request and thus fall back to buffered i/o) 957 * 1 (to accept the i/o request) 958 */ 959 static int gfs2_ok_for_dio(struct gfs2_inode *ip, int rw, loff_t offset) 960 { 961 /* 962 * Should we return an error here? I can't see that O_DIRECT for 963 * a stuffed file makes any sense. For now we'll silently fall 964 * back to buffered I/O 965 */ 966 if (gfs2_is_stuffed(ip)) 967 return 0; 968 969 if (offset >= i_size_read(&ip->i_inode)) 970 return 0; 971 return 1; 972 } 973 974 975 976 static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb, 977 const struct iovec *iov, loff_t offset, 978 unsigned long nr_segs) 979 { 980 struct file *file = iocb->ki_filp; 981 struct inode *inode = file->f_mapping->host; 982 struct gfs2_inode *ip = GFS2_I(inode); 983 struct gfs2_holder gh; 984 int rv; 985 986 /* 987 * Deferred lock, even if its a write, since we do no allocation 988 * on this path. All we need change is atime, and this lock mode 989 * ensures that other nodes have flushed their buffered read caches 990 * (i.e. their page cache entries for this inode). We do not, 991 * unfortunately have the option of only flushing a range like 992 * the VFS does. 993 */ 994 gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, &gh); 995 rv = gfs2_glock_nq(&gh); 996 if (rv) 997 return rv; 998 rv = gfs2_ok_for_dio(ip, rw, offset); 999 if (rv != 1) 1000 goto out; /* dio not valid, fall back to buffered i/o */ 1001 1002 rv = __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, 1003 offset, nr_segs, gfs2_get_block_direct, 1004 NULL, NULL, 0); 1005 out: 1006 gfs2_glock_dq(&gh); 1007 gfs2_holder_uninit(&gh); 1008 return rv; 1009 } 1010 1011 /** 1012 * gfs2_releasepage - free the metadata associated with a page 1013 * @page: the page that's being released 1014 * @gfp_mask: passed from Linux VFS, ignored by us 1015 * 1016 * Call try_to_free_buffers() if the buffers in this page can be 1017 * released. 1018 * 1019 * Returns: 0 1020 */ 1021 1022 int gfs2_releasepage(struct page *page, gfp_t gfp_mask) 1023 { 1024 struct address_space *mapping = page->mapping; 1025 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping); 1026 struct buffer_head *bh, *head; 1027 struct gfs2_bufdata *bd; 1028 1029 if (!page_has_buffers(page)) 1030 return 0; 1031 1032 gfs2_log_lock(sdp); 1033 spin_lock(&sdp->sd_ail_lock); 1034 head = bh = page_buffers(page); 1035 do { 1036 if (atomic_read(&bh->b_count)) 1037 goto cannot_release; 1038 bd = bh->b_private; 1039 if (bd && bd->bd_tr) 1040 goto cannot_release; 1041 if (buffer_pinned(bh) || buffer_dirty(bh)) 1042 goto not_possible; 1043 bh = bh->b_this_page; 1044 } while(bh != head); 1045 spin_unlock(&sdp->sd_ail_lock); 1046 gfs2_log_unlock(sdp); 1047 1048 head = bh = page_buffers(page); 1049 do { 1050 gfs2_log_lock(sdp); 1051 bd = bh->b_private; 1052 if (bd) { 1053 gfs2_assert_warn(sdp, bd->bd_bh == bh); 1054 if (!list_empty(&bd->bd_list)) { 1055 if (!buffer_pinned(bh)) 1056 list_del_init(&bd->bd_list); 1057 else 1058 bd = NULL; 1059 } 1060 if (bd) 1061 bd->bd_bh = NULL; 1062 bh->b_private = NULL; 1063 } 1064 gfs2_log_unlock(sdp); 1065 if (bd) 1066 kmem_cache_free(gfs2_bufdata_cachep, bd); 1067 1068 bh = bh->b_this_page; 1069 } while (bh != head); 1070 1071 return try_to_free_buffers(page); 1072 1073 not_possible: /* Should never happen */ 1074 WARN_ON(buffer_dirty(bh)); 1075 WARN_ON(buffer_pinned(bh)); 1076 cannot_release: 1077 spin_unlock(&sdp->sd_ail_lock); 1078 gfs2_log_unlock(sdp); 1079 return 0; 1080 } 1081 1082 static const struct address_space_operations gfs2_writeback_aops = { 1083 .writepage = gfs2_writepage, 1084 .writepages = gfs2_writepages, 1085 .readpage = gfs2_readpage, 1086 .readpages = gfs2_readpages, 1087 .write_begin = gfs2_write_begin, 1088 .write_end = gfs2_write_end, 1089 .bmap = gfs2_bmap, 1090 .invalidatepage = gfs2_invalidatepage, 1091 .releasepage = gfs2_releasepage, 1092 .direct_IO = gfs2_direct_IO, 1093 .migratepage = buffer_migrate_page, 1094 .is_partially_uptodate = block_is_partially_uptodate, 1095 .error_remove_page = generic_error_remove_page, 1096 }; 1097 1098 static const struct address_space_operations gfs2_ordered_aops = { 1099 .writepage = gfs2_writepage, 1100 .writepages = gfs2_writepages, 1101 .readpage = gfs2_readpage, 1102 .readpages = gfs2_readpages, 1103 .write_begin = gfs2_write_begin, 1104 .write_end = gfs2_write_end, 1105 .set_page_dirty = gfs2_set_page_dirty, 1106 .bmap = gfs2_bmap, 1107 .invalidatepage = gfs2_invalidatepage, 1108 .releasepage = gfs2_releasepage, 1109 .direct_IO = gfs2_direct_IO, 1110 .migratepage = buffer_migrate_page, 1111 .is_partially_uptodate = block_is_partially_uptodate, 1112 .error_remove_page = generic_error_remove_page, 1113 }; 1114 1115 static const struct address_space_operations gfs2_jdata_aops = { 1116 .writepage = gfs2_jdata_writepage, 1117 .writepages = gfs2_jdata_writepages, 1118 .readpage = gfs2_readpage, 1119 .readpages = gfs2_readpages, 1120 .write_begin = gfs2_write_begin, 1121 .write_end = gfs2_write_end, 1122 .set_page_dirty = gfs2_set_page_dirty, 1123 .bmap = gfs2_bmap, 1124 .invalidatepage = gfs2_invalidatepage, 1125 .releasepage = gfs2_releasepage, 1126 .is_partially_uptodate = block_is_partially_uptodate, 1127 .error_remove_page = generic_error_remove_page, 1128 }; 1129 1130 void gfs2_set_aops(struct inode *inode) 1131 { 1132 struct gfs2_inode *ip = GFS2_I(inode); 1133 1134 if (gfs2_is_writeback(ip)) 1135 inode->i_mapping->a_ops = &gfs2_writeback_aops; 1136 else if (gfs2_is_ordered(ip)) 1137 inode->i_mapping->a_ops = &gfs2_ordered_aops; 1138 else if (gfs2_is_jdata(ip)) 1139 inode->i_mapping->a_ops = &gfs2_jdata_aops; 1140 else 1141 BUG(); 1142 } 1143 1144