1 /* -*- mode: c; c-basic-offset: 8; -*- 2 * vim: noexpandtab sw=8 ts=8 sts=0: 3 * 4 * Copyright (C) 2002, 2004 Oracle. All rights reserved. 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public 8 * License as published by the Free Software Foundation; either 9 * version 2 of the License, or (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public 17 * License along with this program; if not, write to the 18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 19 * Boston, MA 021110-1307, USA. 20 */ 21 22 #include <linux/fs.h> 23 #include <linux/slab.h> 24 #include <linux/highmem.h> 25 #include <linux/pagemap.h> 26 #include <asm/byteorder.h> 27 #include <linux/swap.h> 28 #include <linux/pipe_fs_i.h> 29 30 #define MLOG_MASK_PREFIX ML_FILE_IO 31 #include <cluster/masklog.h> 32 33 #include "ocfs2.h" 34 35 #include "alloc.h" 36 #include "aops.h" 37 #include "dlmglue.h" 38 #include "extent_map.h" 39 #include "file.h" 40 #include "inode.h" 41 #include "journal.h" 42 #include "suballoc.h" 43 #include "super.h" 44 #include "symlink.h" 45 46 #include "buffer_head_io.h" 47 48 static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock, 49 struct buffer_head *bh_result, int create) 50 { 51 int err = -EIO; 52 int status; 53 struct ocfs2_dinode *fe = NULL; 54 struct buffer_head *bh = NULL; 55 struct buffer_head *buffer_cache_bh = NULL; 56 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 57 void *kaddr; 58 59 mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode, 60 (unsigned long long)iblock, bh_result, create); 61 62 BUG_ON(ocfs2_inode_is_fast_symlink(inode)); 63 64 if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) { 65 mlog(ML_ERROR, "block offset > PATH_MAX: %llu", 66 (unsigned long long)iblock); 67 goto bail; 68 } 69 70 status = ocfs2_read_block(OCFS2_SB(inode->i_sb), 71 OCFS2_I(inode)->ip_blkno, 72 &bh, OCFS2_BH_CACHED, inode); 73 if (status < 0) { 74 mlog_errno(status); 75 goto bail; 76 } 77 fe = (struct ocfs2_dinode *) bh->b_data; 78 79 if (!OCFS2_IS_VALID_DINODE(fe)) { 80 mlog(ML_ERROR, "Invalid dinode #%llu: signature = %.*s\n", 81 (unsigned long long)le64_to_cpu(fe->i_blkno), 7, 82 fe->i_signature); 83 goto bail; 84 } 85 86 if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb, 87 le32_to_cpu(fe->i_clusters))) { 88 mlog(ML_ERROR, "block offset is outside the allocated size: " 89 "%llu\n", (unsigned long long)iblock); 90 goto bail; 91 } 92 93 /* We don't use the page cache to create symlink data, so if 94 * need be, copy it over from the buffer cache. */ 95 if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) { 96 u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + 97 iblock; 98 buffer_cache_bh = sb_getblk(osb->sb, blkno); 99 if (!buffer_cache_bh) { 100 mlog(ML_ERROR, "couldn't getblock for symlink!\n"); 101 goto bail; 102 } 103 104 /* we haven't locked out transactions, so a commit 105 * could've happened. Since we've got a reference on 106 * the bh, even if it commits while we're doing the 107 * copy, the data is still good. */ 108 if (buffer_jbd(buffer_cache_bh) 109 && ocfs2_inode_is_new(inode)) { 110 kaddr = kmap_atomic(bh_result->b_page, KM_USER0); 111 if (!kaddr) { 112 mlog(ML_ERROR, "couldn't kmap!\n"); 113 goto bail; 114 } 115 memcpy(kaddr + (bh_result->b_size * iblock), 116 buffer_cache_bh->b_data, 117 bh_result->b_size); 118 kunmap_atomic(kaddr, KM_USER0); 119 set_buffer_uptodate(bh_result); 120 } 121 brelse(buffer_cache_bh); 122 } 123 124 map_bh(bh_result, inode->i_sb, 125 le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock); 126 127 err = 0; 128 129 bail: 130 if (bh) 131 brelse(bh); 132 133 mlog_exit(err); 134 return err; 135 } 136 137 static int ocfs2_get_block(struct inode *inode, sector_t iblock, 138 struct buffer_head *bh_result, int create) 139 { 140 int err = 0; 141 unsigned int ext_flags; 142 u64 p_blkno, past_eof; 143 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 144 145 mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode, 146 (unsigned long long)iblock, bh_result, create); 147 148 if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE) 149 mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n", 150 inode, inode->i_ino); 151 152 if (S_ISLNK(inode->i_mode)) { 153 /* this always does I/O for some reason. */ 154 err = ocfs2_symlink_get_block(inode, iblock, bh_result, create); 155 goto bail; 156 } 157 158 err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, NULL, 159 &ext_flags); 160 if (err) { 161 mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, " 162 "%llu, NULL)\n", err, inode, (unsigned long long)iblock, 163 (unsigned long long)p_blkno); 164 goto bail; 165 } 166 167 /* 168 * ocfs2 never allocates in this function - the only time we 169 * need to use BH_New is when we're extending i_size on a file 170 * system which doesn't support holes, in which case BH_New 171 * allows block_prepare_write() to zero. 172 */ 173 mlog_bug_on_msg(create && p_blkno == 0 && ocfs2_sparse_alloc(osb), 174 "ino %lu, iblock %llu\n", inode->i_ino, 175 (unsigned long long)iblock); 176 177 /* Treat the unwritten extent as a hole for zeroing purposes. */ 178 if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN)) 179 map_bh(bh_result, inode->i_sb, p_blkno); 180 181 if (!ocfs2_sparse_alloc(osb)) { 182 if (p_blkno == 0) { 183 err = -EIO; 184 mlog(ML_ERROR, 185 "iblock = %llu p_blkno = %llu blkno=(%llu)\n", 186 (unsigned long long)iblock, 187 (unsigned long long)p_blkno, 188 (unsigned long long)OCFS2_I(inode)->ip_blkno); 189 mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters); 190 dump_stack(); 191 } 192 193 past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode)); 194 mlog(0, "Inode %lu, past_eof = %llu\n", inode->i_ino, 195 (unsigned long long)past_eof); 196 197 if (create && (iblock >= past_eof)) 198 set_buffer_new(bh_result); 199 } 200 201 bail: 202 if (err < 0) 203 err = -EIO; 204 205 mlog_exit(err); 206 return err; 207 } 208 209 static int ocfs2_readpage(struct file *file, struct page *page) 210 { 211 struct inode *inode = page->mapping->host; 212 loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT; 213 int ret, unlock = 1; 214 215 mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0)); 216 217 ret = ocfs2_meta_lock_with_page(inode, NULL, 0, page); 218 if (ret != 0) { 219 if (ret == AOP_TRUNCATED_PAGE) 220 unlock = 0; 221 mlog_errno(ret); 222 goto out; 223 } 224 225 if (down_read_trylock(&OCFS2_I(inode)->ip_alloc_sem) == 0) { 226 ret = AOP_TRUNCATED_PAGE; 227 goto out_meta_unlock; 228 } 229 230 /* 231 * i_size might have just been updated as we grabed the meta lock. We 232 * might now be discovering a truncate that hit on another node. 233 * block_read_full_page->get_block freaks out if it is asked to read 234 * beyond the end of a file, so we check here. Callers 235 * (generic_file_read, vm_ops->fault) are clever enough to check i_size 236 * and notice that the page they just read isn't needed. 237 * 238 * XXX sys_readahead() seems to get that wrong? 239 */ 240 if (start >= i_size_read(inode)) { 241 zero_user_page(page, 0, PAGE_SIZE, KM_USER0); 242 SetPageUptodate(page); 243 ret = 0; 244 goto out_alloc; 245 } 246 247 ret = ocfs2_data_lock_with_page(inode, 0, page); 248 if (ret != 0) { 249 if (ret == AOP_TRUNCATED_PAGE) 250 unlock = 0; 251 mlog_errno(ret); 252 goto out_alloc; 253 } 254 255 ret = block_read_full_page(page, ocfs2_get_block); 256 unlock = 0; 257 258 ocfs2_data_unlock(inode, 0); 259 out_alloc: 260 up_read(&OCFS2_I(inode)->ip_alloc_sem); 261 out_meta_unlock: 262 ocfs2_meta_unlock(inode, 0); 263 out: 264 if (unlock) 265 unlock_page(page); 266 mlog_exit(ret); 267 return ret; 268 } 269 270 /* Note: Because we don't support holes, our allocation has 271 * already happened (allocation writes zeros to the file data) 272 * so we don't have to worry about ordered writes in 273 * ocfs2_writepage. 274 * 275 * ->writepage is called during the process of invalidating the page cache 276 * during blocked lock processing. It can't block on any cluster locks 277 * to during block mapping. It's relying on the fact that the block 278 * mapping can't have disappeared under the dirty pages that it is 279 * being asked to write back. 280 */ 281 static int ocfs2_writepage(struct page *page, struct writeback_control *wbc) 282 { 283 int ret; 284 285 mlog_entry("(0x%p)\n", page); 286 287 ret = block_write_full_page(page, ocfs2_get_block, wbc); 288 289 mlog_exit(ret); 290 291 return ret; 292 } 293 294 /* 295 * This is called from ocfs2_write_zero_page() which has handled it's 296 * own cluster locking and has ensured allocation exists for those 297 * blocks to be written. 298 */ 299 int ocfs2_prepare_write_nolock(struct inode *inode, struct page *page, 300 unsigned from, unsigned to) 301 { 302 int ret; 303 304 down_read(&OCFS2_I(inode)->ip_alloc_sem); 305 306 ret = block_prepare_write(page, from, to, ocfs2_get_block); 307 308 up_read(&OCFS2_I(inode)->ip_alloc_sem); 309 310 return ret; 311 } 312 313 /* Taken from ext3. We don't necessarily need the full blown 314 * functionality yet, but IMHO it's better to cut and paste the whole 315 * thing so we can avoid introducing our own bugs (and easily pick up 316 * their fixes when they happen) --Mark */ 317 int walk_page_buffers( handle_t *handle, 318 struct buffer_head *head, 319 unsigned from, 320 unsigned to, 321 int *partial, 322 int (*fn)( handle_t *handle, 323 struct buffer_head *bh)) 324 { 325 struct buffer_head *bh; 326 unsigned block_start, block_end; 327 unsigned blocksize = head->b_size; 328 int err, ret = 0; 329 struct buffer_head *next; 330 331 for ( bh = head, block_start = 0; 332 ret == 0 && (bh != head || !block_start); 333 block_start = block_end, bh = next) 334 { 335 next = bh->b_this_page; 336 block_end = block_start + blocksize; 337 if (block_end <= from || block_start >= to) { 338 if (partial && !buffer_uptodate(bh)) 339 *partial = 1; 340 continue; 341 } 342 err = (*fn)(handle, bh); 343 if (!ret) 344 ret = err; 345 } 346 return ret; 347 } 348 349 handle_t *ocfs2_start_walk_page_trans(struct inode *inode, 350 struct page *page, 351 unsigned from, 352 unsigned to) 353 { 354 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 355 handle_t *handle = NULL; 356 int ret = 0; 357 358 handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS); 359 if (!handle) { 360 ret = -ENOMEM; 361 mlog_errno(ret); 362 goto out; 363 } 364 365 if (ocfs2_should_order_data(inode)) { 366 ret = walk_page_buffers(handle, 367 page_buffers(page), 368 from, to, NULL, 369 ocfs2_journal_dirty_data); 370 if (ret < 0) 371 mlog_errno(ret); 372 } 373 out: 374 if (ret) { 375 if (handle) 376 ocfs2_commit_trans(osb, handle); 377 handle = ERR_PTR(ret); 378 } 379 return handle; 380 } 381 382 static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block) 383 { 384 sector_t status; 385 u64 p_blkno = 0; 386 int err = 0; 387 struct inode *inode = mapping->host; 388 389 mlog_entry("(block = %llu)\n", (unsigned long long)block); 390 391 /* We don't need to lock journal system files, since they aren't 392 * accessed concurrently from multiple nodes. 393 */ 394 if (!INODE_JOURNAL(inode)) { 395 err = ocfs2_meta_lock(inode, NULL, 0); 396 if (err) { 397 if (err != -ENOENT) 398 mlog_errno(err); 399 goto bail; 400 } 401 down_read(&OCFS2_I(inode)->ip_alloc_sem); 402 } 403 404 err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL, NULL); 405 406 if (!INODE_JOURNAL(inode)) { 407 up_read(&OCFS2_I(inode)->ip_alloc_sem); 408 ocfs2_meta_unlock(inode, 0); 409 } 410 411 if (err) { 412 mlog(ML_ERROR, "get_blocks() failed, block = %llu\n", 413 (unsigned long long)block); 414 mlog_errno(err); 415 goto bail; 416 } 417 418 419 bail: 420 status = err ? 0 : p_blkno; 421 422 mlog_exit((int)status); 423 424 return status; 425 } 426 427 /* 428 * TODO: Make this into a generic get_blocks function. 429 * 430 * From do_direct_io in direct-io.c: 431 * "So what we do is to permit the ->get_blocks function to populate 432 * bh.b_size with the size of IO which is permitted at this offset and 433 * this i_blkbits." 434 * 435 * This function is called directly from get_more_blocks in direct-io.c. 436 * 437 * called like this: dio->get_blocks(dio->inode, fs_startblk, 438 * fs_count, map_bh, dio->rw == WRITE); 439 */ 440 static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock, 441 struct buffer_head *bh_result, int create) 442 { 443 int ret; 444 u64 p_blkno, inode_blocks, contig_blocks; 445 unsigned int ext_flags; 446 unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits; 447 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 448 449 /* This function won't even be called if the request isn't all 450 * nicely aligned and of the right size, so there's no need 451 * for us to check any of that. */ 452 453 inode_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode)); 454 455 /* 456 * Any write past EOF is not allowed because we'd be extending. 457 */ 458 if (create && (iblock + max_blocks) > inode_blocks) { 459 ret = -EIO; 460 goto bail; 461 } 462 463 /* This figures out the size of the next contiguous block, and 464 * our logical offset */ 465 ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, 466 &contig_blocks, &ext_flags); 467 if (ret) { 468 mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n", 469 (unsigned long long)iblock); 470 ret = -EIO; 471 goto bail; 472 } 473 474 if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)) && !p_blkno) { 475 ocfs2_error(inode->i_sb, 476 "Inode %llu has a hole at block %llu\n", 477 (unsigned long long)OCFS2_I(inode)->ip_blkno, 478 (unsigned long long)iblock); 479 ret = -EROFS; 480 goto bail; 481 } 482 483 /* 484 * get_more_blocks() expects us to describe a hole by clearing 485 * the mapped bit on bh_result(). 486 * 487 * Consider an unwritten extent as a hole. 488 */ 489 if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN)) 490 map_bh(bh_result, inode->i_sb, p_blkno); 491 else { 492 /* 493 * ocfs2_prepare_inode_for_write() should have caught 494 * the case where we'd be filling a hole and triggered 495 * a buffered write instead. 496 */ 497 if (create) { 498 ret = -EIO; 499 mlog_errno(ret); 500 goto bail; 501 } 502 503 clear_buffer_mapped(bh_result); 504 } 505 506 /* make sure we don't map more than max_blocks blocks here as 507 that's all the kernel will handle at this point. */ 508 if (max_blocks < contig_blocks) 509 contig_blocks = max_blocks; 510 bh_result->b_size = contig_blocks << blocksize_bits; 511 bail: 512 return ret; 513 } 514 515 /* 516 * ocfs2_dio_end_io is called by the dio core when a dio is finished. We're 517 * particularly interested in the aio/dio case. Like the core uses 518 * i_alloc_sem, we use the rw_lock DLM lock to protect io on one node from 519 * truncation on another. 520 */ 521 static void ocfs2_dio_end_io(struct kiocb *iocb, 522 loff_t offset, 523 ssize_t bytes, 524 void *private) 525 { 526 struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode; 527 int level; 528 529 /* this io's submitter should not have unlocked this before we could */ 530 BUG_ON(!ocfs2_iocb_is_rw_locked(iocb)); 531 532 ocfs2_iocb_clear_rw_locked(iocb); 533 534 level = ocfs2_iocb_rw_locked_level(iocb); 535 if (!level) 536 up_read(&inode->i_alloc_sem); 537 ocfs2_rw_unlock(inode, level); 538 } 539 540 /* 541 * ocfs2_invalidatepage() and ocfs2_releasepage() are shamelessly stolen 542 * from ext3. PageChecked() bits have been removed as OCFS2 does not 543 * do journalled data. 544 */ 545 static void ocfs2_invalidatepage(struct page *page, unsigned long offset) 546 { 547 journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal; 548 549 journal_invalidatepage(journal, page, offset); 550 } 551 552 static int ocfs2_releasepage(struct page *page, gfp_t wait) 553 { 554 journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal; 555 556 if (!page_has_buffers(page)) 557 return 0; 558 return journal_try_to_free_buffers(journal, page, wait); 559 } 560 561 static ssize_t ocfs2_direct_IO(int rw, 562 struct kiocb *iocb, 563 const struct iovec *iov, 564 loff_t offset, 565 unsigned long nr_segs) 566 { 567 struct file *file = iocb->ki_filp; 568 struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host; 569 int ret; 570 571 mlog_entry_void(); 572 573 if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) { 574 /* 575 * We get PR data locks even for O_DIRECT. This 576 * allows concurrent O_DIRECT I/O but doesn't let 577 * O_DIRECT with extending and buffered zeroing writes 578 * race. If they did race then the buffered zeroing 579 * could be written back after the O_DIRECT I/O. It's 580 * one thing to tell people not to mix buffered and 581 * O_DIRECT writes, but expecting them to understand 582 * that file extension is also an implicit buffered 583 * write is too much. By getting the PR we force 584 * writeback of the buffered zeroing before 585 * proceeding. 586 */ 587 ret = ocfs2_data_lock(inode, 0); 588 if (ret < 0) { 589 mlog_errno(ret); 590 goto out; 591 } 592 ocfs2_data_unlock(inode, 0); 593 } 594 595 ret = blockdev_direct_IO_no_locking(rw, iocb, inode, 596 inode->i_sb->s_bdev, iov, offset, 597 nr_segs, 598 ocfs2_direct_IO_get_blocks, 599 ocfs2_dio_end_io); 600 out: 601 mlog_exit(ret); 602 return ret; 603 } 604 605 static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb, 606 u32 cpos, 607 unsigned int *start, 608 unsigned int *end) 609 { 610 unsigned int cluster_start = 0, cluster_end = PAGE_CACHE_SIZE; 611 612 if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) { 613 unsigned int cpp; 614 615 cpp = 1 << (PAGE_CACHE_SHIFT - osb->s_clustersize_bits); 616 617 cluster_start = cpos % cpp; 618 cluster_start = cluster_start << osb->s_clustersize_bits; 619 620 cluster_end = cluster_start + osb->s_clustersize; 621 } 622 623 BUG_ON(cluster_start > PAGE_SIZE); 624 BUG_ON(cluster_end > PAGE_SIZE); 625 626 if (start) 627 *start = cluster_start; 628 if (end) 629 *end = cluster_end; 630 } 631 632 /* 633 * 'from' and 'to' are the region in the page to avoid zeroing. 634 * 635 * If pagesize > clustersize, this function will avoid zeroing outside 636 * of the cluster boundary. 637 * 638 * from == to == 0 is code for "zero the entire cluster region" 639 */ 640 static void ocfs2_clear_page_regions(struct page *page, 641 struct ocfs2_super *osb, u32 cpos, 642 unsigned from, unsigned to) 643 { 644 void *kaddr; 645 unsigned int cluster_start, cluster_end; 646 647 ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end); 648 649 kaddr = kmap_atomic(page, KM_USER0); 650 651 if (from || to) { 652 if (from > cluster_start) 653 memset(kaddr + cluster_start, 0, from - cluster_start); 654 if (to < cluster_end) 655 memset(kaddr + to, 0, cluster_end - to); 656 } else { 657 memset(kaddr + cluster_start, 0, cluster_end - cluster_start); 658 } 659 660 kunmap_atomic(kaddr, KM_USER0); 661 } 662 663 /* 664 * Some of this taken from block_prepare_write(). We already have our 665 * mapping by now though, and the entire write will be allocating or 666 * it won't, so not much need to use BH_New. 667 * 668 * This will also skip zeroing, which is handled externally. 669 */ 670 int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno, 671 struct inode *inode, unsigned int from, 672 unsigned int to, int new) 673 { 674 int ret = 0; 675 struct buffer_head *head, *bh, *wait[2], **wait_bh = wait; 676 unsigned int block_end, block_start; 677 unsigned int bsize = 1 << inode->i_blkbits; 678 679 if (!page_has_buffers(page)) 680 create_empty_buffers(page, bsize, 0); 681 682 head = page_buffers(page); 683 for (bh = head, block_start = 0; bh != head || !block_start; 684 bh = bh->b_this_page, block_start += bsize) { 685 block_end = block_start + bsize; 686 687 clear_buffer_new(bh); 688 689 /* 690 * Ignore blocks outside of our i/o range - 691 * they may belong to unallocated clusters. 692 */ 693 if (block_start >= to || block_end <= from) { 694 if (PageUptodate(page)) 695 set_buffer_uptodate(bh); 696 continue; 697 } 698 699 /* 700 * For an allocating write with cluster size >= page 701 * size, we always write the entire page. 702 */ 703 if (new) 704 set_buffer_new(bh); 705 706 if (!buffer_mapped(bh)) { 707 map_bh(bh, inode->i_sb, *p_blkno); 708 unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); 709 } 710 711 if (PageUptodate(page)) { 712 if (!buffer_uptodate(bh)) 713 set_buffer_uptodate(bh); 714 } else if (!buffer_uptodate(bh) && !buffer_delay(bh) && 715 !buffer_new(bh) && 716 (block_start < from || block_end > to)) { 717 ll_rw_block(READ, 1, &bh); 718 *wait_bh++=bh; 719 } 720 721 *p_blkno = *p_blkno + 1; 722 } 723 724 /* 725 * If we issued read requests - let them complete. 726 */ 727 while(wait_bh > wait) { 728 wait_on_buffer(*--wait_bh); 729 if (!buffer_uptodate(*wait_bh)) 730 ret = -EIO; 731 } 732 733 if (ret == 0 || !new) 734 return ret; 735 736 /* 737 * If we get -EIO above, zero out any newly allocated blocks 738 * to avoid exposing stale data. 739 */ 740 bh = head; 741 block_start = 0; 742 do { 743 block_end = block_start + bsize; 744 if (block_end <= from) 745 goto next_bh; 746 if (block_start >= to) 747 break; 748 749 zero_user_page(page, block_start, bh->b_size, KM_USER0); 750 set_buffer_uptodate(bh); 751 mark_buffer_dirty(bh); 752 753 next_bh: 754 block_start = block_end; 755 bh = bh->b_this_page; 756 } while (bh != head); 757 758 return ret; 759 } 760 761 #if (PAGE_CACHE_SIZE >= OCFS2_MAX_CLUSTERSIZE) 762 #define OCFS2_MAX_CTXT_PAGES 1 763 #else 764 #define OCFS2_MAX_CTXT_PAGES (OCFS2_MAX_CLUSTERSIZE / PAGE_CACHE_SIZE) 765 #endif 766 767 #define OCFS2_MAX_CLUSTERS_PER_PAGE (PAGE_CACHE_SIZE / OCFS2_MIN_CLUSTERSIZE) 768 769 /* 770 * Describe the state of a single cluster to be written to. 771 */ 772 struct ocfs2_write_cluster_desc { 773 u32 c_cpos; 774 u32 c_phys; 775 /* 776 * Give this a unique field because c_phys eventually gets 777 * filled. 778 */ 779 unsigned c_new; 780 unsigned c_unwritten; 781 }; 782 783 static inline int ocfs2_should_zero_cluster(struct ocfs2_write_cluster_desc *d) 784 { 785 return d->c_new || d->c_unwritten; 786 } 787 788 struct ocfs2_write_ctxt { 789 /* Logical cluster position / len of write */ 790 u32 w_cpos; 791 u32 w_clen; 792 793 struct ocfs2_write_cluster_desc w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE]; 794 795 /* 796 * This is true if page_size > cluster_size. 797 * 798 * It triggers a set of special cases during write which might 799 * have to deal with allocating writes to partial pages. 800 */ 801 unsigned int w_large_pages; 802 803 /* 804 * Pages involved in this write. 805 * 806 * w_target_page is the page being written to by the user. 807 * 808 * w_pages is an array of pages which always contains 809 * w_target_page, and in the case of an allocating write with 810 * page_size < cluster size, it will contain zero'd and mapped 811 * pages adjacent to w_target_page which need to be written 812 * out in so that future reads from that region will get 813 * zero's. 814 */ 815 struct page *w_pages[OCFS2_MAX_CTXT_PAGES]; 816 unsigned int w_num_pages; 817 struct page *w_target_page; 818 819 /* 820 * ocfs2_write_end() uses this to know what the real range to 821 * write in the target should be. 822 */ 823 unsigned int w_target_from; 824 unsigned int w_target_to; 825 826 /* 827 * We could use journal_current_handle() but this is cleaner, 828 * IMHO -Mark 829 */ 830 handle_t *w_handle; 831 832 struct buffer_head *w_di_bh; 833 834 struct ocfs2_cached_dealloc_ctxt w_dealloc; 835 }; 836 837 static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc) 838 { 839 int i; 840 841 for(i = 0; i < wc->w_num_pages; i++) { 842 if (wc->w_pages[i] == NULL) 843 continue; 844 845 unlock_page(wc->w_pages[i]); 846 mark_page_accessed(wc->w_pages[i]); 847 page_cache_release(wc->w_pages[i]); 848 } 849 850 brelse(wc->w_di_bh); 851 kfree(wc); 852 } 853 854 static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp, 855 struct ocfs2_super *osb, loff_t pos, 856 unsigned len, struct buffer_head *di_bh) 857 { 858 struct ocfs2_write_ctxt *wc; 859 860 wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS); 861 if (!wc) 862 return -ENOMEM; 863 864 wc->w_cpos = pos >> osb->s_clustersize_bits; 865 wc->w_clen = ocfs2_clusters_for_bytes(osb->sb, len); 866 get_bh(di_bh); 867 wc->w_di_bh = di_bh; 868 869 if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) 870 wc->w_large_pages = 1; 871 else 872 wc->w_large_pages = 0; 873 874 ocfs2_init_dealloc_ctxt(&wc->w_dealloc); 875 876 *wcp = wc; 877 878 return 0; 879 } 880 881 /* 882 * If a page has any new buffers, zero them out here, and mark them uptodate 883 * and dirty so they'll be written out (in order to prevent uninitialised 884 * block data from leaking). And clear the new bit. 885 */ 886 static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to) 887 { 888 unsigned int block_start, block_end; 889 struct buffer_head *head, *bh; 890 891 BUG_ON(!PageLocked(page)); 892 if (!page_has_buffers(page)) 893 return; 894 895 bh = head = page_buffers(page); 896 block_start = 0; 897 do { 898 block_end = block_start + bh->b_size; 899 900 if (buffer_new(bh)) { 901 if (block_end > from && block_start < to) { 902 if (!PageUptodate(page)) { 903 unsigned start, end; 904 905 start = max(from, block_start); 906 end = min(to, block_end); 907 908 zero_user_page(page, start, end - start, KM_USER0); 909 set_buffer_uptodate(bh); 910 } 911 912 clear_buffer_new(bh); 913 mark_buffer_dirty(bh); 914 } 915 } 916 917 block_start = block_end; 918 bh = bh->b_this_page; 919 } while (bh != head); 920 } 921 922 /* 923 * Only called when we have a failure during allocating write to write 924 * zero's to the newly allocated region. 925 */ 926 static void ocfs2_write_failure(struct inode *inode, 927 struct ocfs2_write_ctxt *wc, 928 loff_t user_pos, unsigned user_len) 929 { 930 int i; 931 unsigned from, to; 932 struct page *tmppage; 933 934 ocfs2_zero_new_buffers(wc->w_target_page, user_pos, user_len); 935 936 if (wc->w_large_pages) { 937 from = wc->w_target_from; 938 to = wc->w_target_to; 939 } else { 940 from = 0; 941 to = PAGE_CACHE_SIZE; 942 } 943 944 for(i = 0; i < wc->w_num_pages; i++) { 945 tmppage = wc->w_pages[i]; 946 947 if (ocfs2_should_order_data(inode)) 948 walk_page_buffers(wc->w_handle, page_buffers(tmppage), 949 from, to, NULL, 950 ocfs2_journal_dirty_data); 951 952 block_commit_write(tmppage, from, to); 953 } 954 } 955 956 static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno, 957 struct ocfs2_write_ctxt *wc, 958 struct page *page, u32 cpos, 959 loff_t user_pos, unsigned user_len, 960 int new) 961 { 962 int ret; 963 unsigned int map_from = 0, map_to = 0; 964 unsigned int cluster_start, cluster_end; 965 unsigned int user_data_from = 0, user_data_to = 0; 966 967 ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos, 968 &cluster_start, &cluster_end); 969 970 if (page == wc->w_target_page) { 971 map_from = user_pos & (PAGE_CACHE_SIZE - 1); 972 map_to = map_from + user_len; 973 974 if (new) 975 ret = ocfs2_map_page_blocks(page, p_blkno, inode, 976 cluster_start, cluster_end, 977 new); 978 else 979 ret = ocfs2_map_page_blocks(page, p_blkno, inode, 980 map_from, map_to, new); 981 if (ret) { 982 mlog_errno(ret); 983 goto out; 984 } 985 986 user_data_from = map_from; 987 user_data_to = map_to; 988 if (new) { 989 map_from = cluster_start; 990 map_to = cluster_end; 991 } 992 993 wc->w_target_from = map_from; 994 wc->w_target_to = map_to; 995 } else { 996 /* 997 * If we haven't allocated the new page yet, we 998 * shouldn't be writing it out without copying user 999 * data. This is likely a math error from the caller. 1000 */ 1001 BUG_ON(!new); 1002 1003 map_from = cluster_start; 1004 map_to = cluster_end; 1005 1006 ret = ocfs2_map_page_blocks(page, p_blkno, inode, 1007 cluster_start, cluster_end, new); 1008 if (ret) { 1009 mlog_errno(ret); 1010 goto out; 1011 } 1012 } 1013 1014 /* 1015 * Parts of newly allocated pages need to be zero'd. 1016 * 1017 * Above, we have also rewritten 'to' and 'from' - as far as 1018 * the rest of the function is concerned, the entire cluster 1019 * range inside of a page needs to be written. 1020 * 1021 * We can skip this if the page is up to date - it's already 1022 * been zero'd from being read in as a hole. 1023 */ 1024 if (new && !PageUptodate(page)) 1025 ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb), 1026 cpos, user_data_from, user_data_to); 1027 1028 flush_dcache_page(page); 1029 1030 out: 1031 return ret; 1032 } 1033 1034 /* 1035 * This function will only grab one clusters worth of pages. 1036 */ 1037 static int ocfs2_grab_pages_for_write(struct address_space *mapping, 1038 struct ocfs2_write_ctxt *wc, 1039 u32 cpos, loff_t user_pos, int new, 1040 struct page *mmap_page) 1041 { 1042 int ret = 0, i; 1043 unsigned long start, target_index, index; 1044 struct inode *inode = mapping->host; 1045 1046 target_index = user_pos >> PAGE_CACHE_SHIFT; 1047 1048 /* 1049 * Figure out how many pages we'll be manipulating here. For 1050 * non allocating write, we just change the one 1051 * page. Otherwise, we'll need a whole clusters worth. 1052 */ 1053 if (new) { 1054 wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb); 1055 start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos); 1056 } else { 1057 wc->w_num_pages = 1; 1058 start = target_index; 1059 } 1060 1061 for(i = 0; i < wc->w_num_pages; i++) { 1062 index = start + i; 1063 1064 if (index == target_index && mmap_page) { 1065 /* 1066 * ocfs2_pagemkwrite() is a little different 1067 * and wants us to directly use the page 1068 * passed in. 1069 */ 1070 lock_page(mmap_page); 1071 1072 if (mmap_page->mapping != mapping) { 1073 unlock_page(mmap_page); 1074 /* 1075 * Sanity check - the locking in 1076 * ocfs2_pagemkwrite() should ensure 1077 * that this code doesn't trigger. 1078 */ 1079 ret = -EINVAL; 1080 mlog_errno(ret); 1081 goto out; 1082 } 1083 1084 page_cache_get(mmap_page); 1085 wc->w_pages[i] = mmap_page; 1086 } else { 1087 wc->w_pages[i] = find_or_create_page(mapping, index, 1088 GFP_NOFS); 1089 if (!wc->w_pages[i]) { 1090 ret = -ENOMEM; 1091 mlog_errno(ret); 1092 goto out; 1093 } 1094 } 1095 1096 if (index == target_index) 1097 wc->w_target_page = wc->w_pages[i]; 1098 } 1099 out: 1100 return ret; 1101 } 1102 1103 /* 1104 * Prepare a single cluster for write one cluster into the file. 1105 */ 1106 static int ocfs2_write_cluster(struct address_space *mapping, 1107 u32 phys, unsigned int unwritten, 1108 struct ocfs2_alloc_context *data_ac, 1109 struct ocfs2_alloc_context *meta_ac, 1110 struct ocfs2_write_ctxt *wc, u32 cpos, 1111 loff_t user_pos, unsigned user_len) 1112 { 1113 int ret, i, new, should_zero = 0; 1114 u64 v_blkno, p_blkno; 1115 struct inode *inode = mapping->host; 1116 1117 new = phys == 0 ? 1 : 0; 1118 if (new || unwritten) 1119 should_zero = 1; 1120 1121 if (new) { 1122 u32 tmp_pos; 1123 1124 /* 1125 * This is safe to call with the page locks - it won't take 1126 * any additional semaphores or cluster locks. 1127 */ 1128 tmp_pos = cpos; 1129 ret = ocfs2_do_extend_allocation(OCFS2_SB(inode->i_sb), inode, 1130 &tmp_pos, 1, 0, wc->w_di_bh, 1131 wc->w_handle, data_ac, 1132 meta_ac, NULL); 1133 /* 1134 * This shouldn't happen because we must have already 1135 * calculated the correct meta data allocation required. The 1136 * internal tree allocation code should know how to increase 1137 * transaction credits itself. 1138 * 1139 * If need be, we could handle -EAGAIN for a 1140 * RESTART_TRANS here. 1141 */ 1142 mlog_bug_on_msg(ret == -EAGAIN, 1143 "Inode %llu: EAGAIN return during allocation.\n", 1144 (unsigned long long)OCFS2_I(inode)->ip_blkno); 1145 if (ret < 0) { 1146 mlog_errno(ret); 1147 goto out; 1148 } 1149 } else if (unwritten) { 1150 ret = ocfs2_mark_extent_written(inode, wc->w_di_bh, 1151 wc->w_handle, cpos, 1, phys, 1152 meta_ac, &wc->w_dealloc); 1153 if (ret < 0) { 1154 mlog_errno(ret); 1155 goto out; 1156 } 1157 } 1158 1159 if (should_zero) 1160 v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, cpos); 1161 else 1162 v_blkno = user_pos >> inode->i_sb->s_blocksize_bits; 1163 1164 /* 1165 * The only reason this should fail is due to an inability to 1166 * find the extent added. 1167 */ 1168 ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL, 1169 NULL); 1170 if (ret < 0) { 1171 ocfs2_error(inode->i_sb, "Corrupting extend for inode %llu, " 1172 "at logical block %llu", 1173 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1174 (unsigned long long)v_blkno); 1175 goto out; 1176 } 1177 1178 BUG_ON(p_blkno == 0); 1179 1180 for(i = 0; i < wc->w_num_pages; i++) { 1181 int tmpret; 1182 1183 tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc, 1184 wc->w_pages[i], cpos, 1185 user_pos, user_len, 1186 should_zero); 1187 if (tmpret) { 1188 mlog_errno(tmpret); 1189 if (ret == 0) 1190 tmpret = ret; 1191 } 1192 } 1193 1194 /* 1195 * We only have cleanup to do in case of allocating write. 1196 */ 1197 if (ret && new) 1198 ocfs2_write_failure(inode, wc, user_pos, user_len); 1199 1200 out: 1201 1202 return ret; 1203 } 1204 1205 static int ocfs2_write_cluster_by_desc(struct address_space *mapping, 1206 struct ocfs2_alloc_context *data_ac, 1207 struct ocfs2_alloc_context *meta_ac, 1208 struct ocfs2_write_ctxt *wc, 1209 loff_t pos, unsigned len) 1210 { 1211 int ret, i; 1212 struct ocfs2_write_cluster_desc *desc; 1213 1214 for (i = 0; i < wc->w_clen; i++) { 1215 desc = &wc->w_desc[i]; 1216 1217 ret = ocfs2_write_cluster(mapping, desc->c_phys, 1218 desc->c_unwritten, data_ac, meta_ac, 1219 wc, desc->c_cpos, pos, len); 1220 if (ret) { 1221 mlog_errno(ret); 1222 goto out; 1223 } 1224 } 1225 1226 ret = 0; 1227 out: 1228 return ret; 1229 } 1230 1231 /* 1232 * ocfs2_write_end() wants to know which parts of the target page it 1233 * should complete the write on. It's easiest to compute them ahead of 1234 * time when a more complete view of the write is available. 1235 */ 1236 static void ocfs2_set_target_boundaries(struct ocfs2_super *osb, 1237 struct ocfs2_write_ctxt *wc, 1238 loff_t pos, unsigned len, int alloc) 1239 { 1240 struct ocfs2_write_cluster_desc *desc; 1241 1242 wc->w_target_from = pos & (PAGE_CACHE_SIZE - 1); 1243 wc->w_target_to = wc->w_target_from + len; 1244 1245 if (alloc == 0) 1246 return; 1247 1248 /* 1249 * Allocating write - we may have different boundaries based 1250 * on page size and cluster size. 1251 * 1252 * NOTE: We can no longer compute one value from the other as 1253 * the actual write length and user provided length may be 1254 * different. 1255 */ 1256 1257 if (wc->w_large_pages) { 1258 /* 1259 * We only care about the 1st and last cluster within 1260 * our range and whether they should be zero'd or not. Either 1261 * value may be extended out to the start/end of a 1262 * newly allocated cluster. 1263 */ 1264 desc = &wc->w_desc[0]; 1265 if (ocfs2_should_zero_cluster(desc)) 1266 ocfs2_figure_cluster_boundaries(osb, 1267 desc->c_cpos, 1268 &wc->w_target_from, 1269 NULL); 1270 1271 desc = &wc->w_desc[wc->w_clen - 1]; 1272 if (ocfs2_should_zero_cluster(desc)) 1273 ocfs2_figure_cluster_boundaries(osb, 1274 desc->c_cpos, 1275 NULL, 1276 &wc->w_target_to); 1277 } else { 1278 wc->w_target_from = 0; 1279 wc->w_target_to = PAGE_CACHE_SIZE; 1280 } 1281 } 1282 1283 /* 1284 * Populate each single-cluster write descriptor in the write context 1285 * with information about the i/o to be done. 1286 * 1287 * Returns the number of clusters that will have to be allocated, as 1288 * well as a worst case estimate of the number of extent records that 1289 * would have to be created during a write to an unwritten region. 1290 */ 1291 static int ocfs2_populate_write_desc(struct inode *inode, 1292 struct ocfs2_write_ctxt *wc, 1293 unsigned int *clusters_to_alloc, 1294 unsigned int *extents_to_split) 1295 { 1296 int ret; 1297 struct ocfs2_write_cluster_desc *desc; 1298 unsigned int num_clusters = 0; 1299 unsigned int ext_flags = 0; 1300 u32 phys = 0; 1301 int i; 1302 1303 *clusters_to_alloc = 0; 1304 *extents_to_split = 0; 1305 1306 for (i = 0; i < wc->w_clen; i++) { 1307 desc = &wc->w_desc[i]; 1308 desc->c_cpos = wc->w_cpos + i; 1309 1310 if (num_clusters == 0) { 1311 /* 1312 * Need to look up the next extent record. 1313 */ 1314 ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys, 1315 &num_clusters, &ext_flags); 1316 if (ret) { 1317 mlog_errno(ret); 1318 goto out; 1319 } 1320 1321 /* 1322 * Assume worst case - that we're writing in 1323 * the middle of the extent. 1324 * 1325 * We can assume that the write proceeds from 1326 * left to right, in which case the extent 1327 * insert code is smart enough to coalesce the 1328 * next splits into the previous records created. 1329 */ 1330 if (ext_flags & OCFS2_EXT_UNWRITTEN) 1331 *extents_to_split = *extents_to_split + 2; 1332 } else if (phys) { 1333 /* 1334 * Only increment phys if it doesn't describe 1335 * a hole. 1336 */ 1337 phys++; 1338 } 1339 1340 desc->c_phys = phys; 1341 if (phys == 0) { 1342 desc->c_new = 1; 1343 *clusters_to_alloc = *clusters_to_alloc + 1; 1344 } 1345 if (ext_flags & OCFS2_EXT_UNWRITTEN) 1346 desc->c_unwritten = 1; 1347 1348 num_clusters--; 1349 } 1350 1351 ret = 0; 1352 out: 1353 return ret; 1354 } 1355 1356 int ocfs2_write_begin_nolock(struct address_space *mapping, 1357 loff_t pos, unsigned len, unsigned flags, 1358 struct page **pagep, void **fsdata, 1359 struct buffer_head *di_bh, struct page *mmap_page) 1360 { 1361 int ret, credits = OCFS2_INODE_UPDATE_CREDITS; 1362 unsigned int clusters_to_alloc, extents_to_split; 1363 struct ocfs2_write_ctxt *wc; 1364 struct inode *inode = mapping->host; 1365 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1366 struct ocfs2_dinode *di; 1367 struct ocfs2_alloc_context *data_ac = NULL; 1368 struct ocfs2_alloc_context *meta_ac = NULL; 1369 handle_t *handle; 1370 1371 ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, di_bh); 1372 if (ret) { 1373 mlog_errno(ret); 1374 return ret; 1375 } 1376 1377 ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc, 1378 &extents_to_split); 1379 if (ret) { 1380 mlog_errno(ret); 1381 goto out; 1382 } 1383 1384 di = (struct ocfs2_dinode *)wc->w_di_bh->b_data; 1385 1386 /* 1387 * We set w_target_from, w_target_to here so that 1388 * ocfs2_write_end() knows which range in the target page to 1389 * write out. An allocation requires that we write the entire 1390 * cluster range. 1391 */ 1392 if (clusters_to_alloc || extents_to_split) { 1393 /* 1394 * XXX: We are stretching the limits of 1395 * ocfs2_lock_allocators(). It greatly over-estimates 1396 * the work to be done. 1397 */ 1398 ret = ocfs2_lock_allocators(inode, di, clusters_to_alloc, 1399 extents_to_split, &data_ac, &meta_ac); 1400 if (ret) { 1401 mlog_errno(ret); 1402 goto out; 1403 } 1404 1405 credits = ocfs2_calc_extend_credits(inode->i_sb, di, 1406 clusters_to_alloc); 1407 1408 } 1409 1410 ocfs2_set_target_boundaries(osb, wc, pos, len, 1411 clusters_to_alloc + extents_to_split); 1412 1413 handle = ocfs2_start_trans(osb, credits); 1414 if (IS_ERR(handle)) { 1415 ret = PTR_ERR(handle); 1416 mlog_errno(ret); 1417 goto out; 1418 } 1419 1420 wc->w_handle = handle; 1421 1422 /* 1423 * We don't want this to fail in ocfs2_write_end(), so do it 1424 * here. 1425 */ 1426 ret = ocfs2_journal_access(handle, inode, wc->w_di_bh, 1427 OCFS2_JOURNAL_ACCESS_WRITE); 1428 if (ret) { 1429 mlog_errno(ret); 1430 goto out_commit; 1431 } 1432 1433 /* 1434 * Fill our page array first. That way we've grabbed enough so 1435 * that we can zero and flush if we error after adding the 1436 * extent. 1437 */ 1438 ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos, 1439 clusters_to_alloc + extents_to_split, 1440 mmap_page); 1441 if (ret) { 1442 mlog_errno(ret); 1443 goto out_commit; 1444 } 1445 1446 ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos, 1447 len); 1448 if (ret) { 1449 mlog_errno(ret); 1450 goto out_commit; 1451 } 1452 1453 if (data_ac) 1454 ocfs2_free_alloc_context(data_ac); 1455 if (meta_ac) 1456 ocfs2_free_alloc_context(meta_ac); 1457 1458 *pagep = wc->w_target_page; 1459 *fsdata = wc; 1460 return 0; 1461 out_commit: 1462 ocfs2_commit_trans(osb, handle); 1463 1464 out: 1465 ocfs2_free_write_ctxt(wc); 1466 1467 if (data_ac) 1468 ocfs2_free_alloc_context(data_ac); 1469 if (meta_ac) 1470 ocfs2_free_alloc_context(meta_ac); 1471 return ret; 1472 } 1473 1474 int ocfs2_write_begin(struct file *file, struct address_space *mapping, 1475 loff_t pos, unsigned len, unsigned flags, 1476 struct page **pagep, void **fsdata) 1477 { 1478 int ret; 1479 struct buffer_head *di_bh = NULL; 1480 struct inode *inode = mapping->host; 1481 1482 ret = ocfs2_meta_lock(inode, &di_bh, 1); 1483 if (ret) { 1484 mlog_errno(ret); 1485 return ret; 1486 } 1487 1488 /* 1489 * Take alloc sem here to prevent concurrent lookups. That way 1490 * the mapping, zeroing and tree manipulation within 1491 * ocfs2_write() will be safe against ->readpage(). This 1492 * should also serve to lock out allocation from a shared 1493 * writeable region. 1494 */ 1495 down_write(&OCFS2_I(inode)->ip_alloc_sem); 1496 1497 ret = ocfs2_data_lock(inode, 1); 1498 if (ret) { 1499 mlog_errno(ret); 1500 goto out_fail; 1501 } 1502 1503 ret = ocfs2_write_begin_nolock(mapping, pos, len, flags, pagep, 1504 fsdata, di_bh, NULL); 1505 if (ret) { 1506 mlog_errno(ret); 1507 goto out_fail_data; 1508 } 1509 1510 brelse(di_bh); 1511 1512 return 0; 1513 1514 out_fail_data: 1515 ocfs2_data_unlock(inode, 1); 1516 out_fail: 1517 up_write(&OCFS2_I(inode)->ip_alloc_sem); 1518 1519 brelse(di_bh); 1520 ocfs2_meta_unlock(inode, 1); 1521 1522 return ret; 1523 } 1524 1525 int ocfs2_write_end_nolock(struct address_space *mapping, 1526 loff_t pos, unsigned len, unsigned copied, 1527 struct page *page, void *fsdata) 1528 { 1529 int i; 1530 unsigned from, to, start = pos & (PAGE_CACHE_SIZE - 1); 1531 struct inode *inode = mapping->host; 1532 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1533 struct ocfs2_write_ctxt *wc = fsdata; 1534 struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data; 1535 handle_t *handle = wc->w_handle; 1536 struct page *tmppage; 1537 1538 if (unlikely(copied < len)) { 1539 if (!PageUptodate(wc->w_target_page)) 1540 copied = 0; 1541 1542 ocfs2_zero_new_buffers(wc->w_target_page, start+copied, 1543 start+len); 1544 } 1545 flush_dcache_page(wc->w_target_page); 1546 1547 for(i = 0; i < wc->w_num_pages; i++) { 1548 tmppage = wc->w_pages[i]; 1549 1550 if (tmppage == wc->w_target_page) { 1551 from = wc->w_target_from; 1552 to = wc->w_target_to; 1553 1554 BUG_ON(from > PAGE_CACHE_SIZE || 1555 to > PAGE_CACHE_SIZE || 1556 to < from); 1557 } else { 1558 /* 1559 * Pages adjacent to the target (if any) imply 1560 * a hole-filling write in which case we want 1561 * to flush their entire range. 1562 */ 1563 from = 0; 1564 to = PAGE_CACHE_SIZE; 1565 } 1566 1567 if (ocfs2_should_order_data(inode)) 1568 walk_page_buffers(wc->w_handle, page_buffers(tmppage), 1569 from, to, NULL, 1570 ocfs2_journal_dirty_data); 1571 1572 block_commit_write(tmppage, from, to); 1573 } 1574 1575 pos += copied; 1576 if (pos > inode->i_size) { 1577 i_size_write(inode, pos); 1578 mark_inode_dirty(inode); 1579 } 1580 inode->i_blocks = ocfs2_inode_sector_count(inode); 1581 di->i_size = cpu_to_le64((u64)i_size_read(inode)); 1582 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1583 di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec); 1584 di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec); 1585 ocfs2_journal_dirty(handle, wc->w_di_bh); 1586 1587 ocfs2_commit_trans(osb, handle); 1588 1589 ocfs2_run_deallocs(osb, &wc->w_dealloc); 1590 1591 ocfs2_free_write_ctxt(wc); 1592 1593 return copied; 1594 } 1595 1596 int ocfs2_write_end(struct file *file, struct address_space *mapping, 1597 loff_t pos, unsigned len, unsigned copied, 1598 struct page *page, void *fsdata) 1599 { 1600 int ret; 1601 struct inode *inode = mapping->host; 1602 1603 ret = ocfs2_write_end_nolock(mapping, pos, len, copied, page, fsdata); 1604 1605 ocfs2_data_unlock(inode, 1); 1606 up_write(&OCFS2_I(inode)->ip_alloc_sem); 1607 ocfs2_meta_unlock(inode, 1); 1608 1609 return ret; 1610 } 1611 1612 const struct address_space_operations ocfs2_aops = { 1613 .readpage = ocfs2_readpage, 1614 .writepage = ocfs2_writepage, 1615 .bmap = ocfs2_bmap, 1616 .sync_page = block_sync_page, 1617 .direct_IO = ocfs2_direct_IO, 1618 .invalidatepage = ocfs2_invalidatepage, 1619 .releasepage = ocfs2_releasepage, 1620 .migratepage = buffer_migrate_page, 1621 }; 1622