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 #include <linux/mpage.h> 30 31 #define MLOG_MASK_PREFIX ML_FILE_IO 32 #include <cluster/masklog.h> 33 34 #include "ocfs2.h" 35 36 #include "alloc.h" 37 #include "aops.h" 38 #include "dlmglue.h" 39 #include "extent_map.h" 40 #include "file.h" 41 #include "inode.h" 42 #include "journal.h" 43 #include "suballoc.h" 44 #include "super.h" 45 #include "symlink.h" 46 47 #include "buffer_head_io.h" 48 49 static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock, 50 struct buffer_head *bh_result, int create) 51 { 52 int err = -EIO; 53 int status; 54 struct ocfs2_dinode *fe = NULL; 55 struct buffer_head *bh = NULL; 56 struct buffer_head *buffer_cache_bh = NULL; 57 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 58 void *kaddr; 59 60 mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode, 61 (unsigned long long)iblock, bh_result, create); 62 63 BUG_ON(ocfs2_inode_is_fast_symlink(inode)); 64 65 if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) { 66 mlog(ML_ERROR, "block offset > PATH_MAX: %llu", 67 (unsigned long long)iblock); 68 goto bail; 69 } 70 71 status = ocfs2_read_block(OCFS2_SB(inode->i_sb), 72 OCFS2_I(inode)->ip_blkno, 73 &bh, OCFS2_BH_CACHED, inode); 74 if (status < 0) { 75 mlog_errno(status); 76 goto bail; 77 } 78 fe = (struct ocfs2_dinode *) bh->b_data; 79 80 if (!OCFS2_IS_VALID_DINODE(fe)) { 81 mlog(ML_ERROR, "Invalid dinode #%llu: signature = %.*s\n", 82 (unsigned long long)le64_to_cpu(fe->i_blkno), 7, 83 fe->i_signature); 84 goto bail; 85 } 86 87 if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb, 88 le32_to_cpu(fe->i_clusters))) { 89 mlog(ML_ERROR, "block offset is outside the allocated size: " 90 "%llu\n", (unsigned long long)iblock); 91 goto bail; 92 } 93 94 /* We don't use the page cache to create symlink data, so if 95 * need be, copy it over from the buffer cache. */ 96 if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) { 97 u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + 98 iblock; 99 buffer_cache_bh = sb_getblk(osb->sb, blkno); 100 if (!buffer_cache_bh) { 101 mlog(ML_ERROR, "couldn't getblock for symlink!\n"); 102 goto bail; 103 } 104 105 /* we haven't locked out transactions, so a commit 106 * could've happened. Since we've got a reference on 107 * the bh, even if it commits while we're doing the 108 * copy, the data is still good. */ 109 if (buffer_jbd(buffer_cache_bh) 110 && ocfs2_inode_is_new(inode)) { 111 kaddr = kmap_atomic(bh_result->b_page, KM_USER0); 112 if (!kaddr) { 113 mlog(ML_ERROR, "couldn't kmap!\n"); 114 goto bail; 115 } 116 memcpy(kaddr + (bh_result->b_size * iblock), 117 buffer_cache_bh->b_data, 118 bh_result->b_size); 119 kunmap_atomic(kaddr, KM_USER0); 120 set_buffer_uptodate(bh_result); 121 } 122 brelse(buffer_cache_bh); 123 } 124 125 map_bh(bh_result, inode->i_sb, 126 le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock); 127 128 err = 0; 129 130 bail: 131 if (bh) 132 brelse(bh); 133 134 mlog_exit(err); 135 return err; 136 } 137 138 static int ocfs2_get_block(struct inode *inode, sector_t iblock, 139 struct buffer_head *bh_result, int create) 140 { 141 int err = 0; 142 unsigned int ext_flags; 143 u64 max_blocks = bh_result->b_size >> inode->i_blkbits; 144 u64 p_blkno, count, past_eof; 145 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 146 147 mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode, 148 (unsigned long long)iblock, bh_result, create); 149 150 if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE) 151 mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n", 152 inode, inode->i_ino); 153 154 if (S_ISLNK(inode->i_mode)) { 155 /* this always does I/O for some reason. */ 156 err = ocfs2_symlink_get_block(inode, iblock, bh_result, create); 157 goto bail; 158 } 159 160 err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, &count, 161 &ext_flags); 162 if (err) { 163 mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, " 164 "%llu, NULL)\n", err, inode, (unsigned long long)iblock, 165 (unsigned long long)p_blkno); 166 goto bail; 167 } 168 169 if (max_blocks < count) 170 count = max_blocks; 171 172 /* 173 * ocfs2 never allocates in this function - the only time we 174 * need to use BH_New is when we're extending i_size on a file 175 * system which doesn't support holes, in which case BH_New 176 * allows block_prepare_write() to zero. 177 */ 178 mlog_bug_on_msg(create && p_blkno == 0 && ocfs2_sparse_alloc(osb), 179 "ino %lu, iblock %llu\n", inode->i_ino, 180 (unsigned long long)iblock); 181 182 /* Treat the unwritten extent as a hole for zeroing purposes. */ 183 if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN)) 184 map_bh(bh_result, inode->i_sb, p_blkno); 185 186 bh_result->b_size = count << inode->i_blkbits; 187 188 if (!ocfs2_sparse_alloc(osb)) { 189 if (p_blkno == 0) { 190 err = -EIO; 191 mlog(ML_ERROR, 192 "iblock = %llu p_blkno = %llu blkno=(%llu)\n", 193 (unsigned long long)iblock, 194 (unsigned long long)p_blkno, 195 (unsigned long long)OCFS2_I(inode)->ip_blkno); 196 mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters); 197 dump_stack(); 198 } 199 200 past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode)); 201 mlog(0, "Inode %lu, past_eof = %llu\n", inode->i_ino, 202 (unsigned long long)past_eof); 203 204 if (create && (iblock >= past_eof)) 205 set_buffer_new(bh_result); 206 } 207 208 bail: 209 if (err < 0) 210 err = -EIO; 211 212 mlog_exit(err); 213 return err; 214 } 215 216 int ocfs2_read_inline_data(struct inode *inode, struct page *page, 217 struct buffer_head *di_bh) 218 { 219 void *kaddr; 220 loff_t size; 221 struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data; 222 223 if (!(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL)) { 224 ocfs2_error(inode->i_sb, "Inode %llu lost inline data flag", 225 (unsigned long long)OCFS2_I(inode)->ip_blkno); 226 return -EROFS; 227 } 228 229 size = i_size_read(inode); 230 231 if (size > PAGE_CACHE_SIZE || 232 size > ocfs2_max_inline_data(inode->i_sb)) { 233 ocfs2_error(inode->i_sb, 234 "Inode %llu has with inline data has bad size: %Lu", 235 (unsigned long long)OCFS2_I(inode)->ip_blkno, 236 (unsigned long long)size); 237 return -EROFS; 238 } 239 240 kaddr = kmap_atomic(page, KM_USER0); 241 if (size) 242 memcpy(kaddr, di->id2.i_data.id_data, size); 243 /* Clear the remaining part of the page */ 244 memset(kaddr + size, 0, PAGE_CACHE_SIZE - size); 245 flush_dcache_page(page); 246 kunmap_atomic(kaddr, KM_USER0); 247 248 SetPageUptodate(page); 249 250 return 0; 251 } 252 253 static int ocfs2_readpage_inline(struct inode *inode, struct page *page) 254 { 255 int ret; 256 struct buffer_head *di_bh = NULL; 257 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 258 259 BUG_ON(!PageLocked(page)); 260 BUG_ON(!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)); 261 262 ret = ocfs2_read_block(osb, OCFS2_I(inode)->ip_blkno, &di_bh, 263 OCFS2_BH_CACHED, inode); 264 if (ret) { 265 mlog_errno(ret); 266 goto out; 267 } 268 269 ret = ocfs2_read_inline_data(inode, page, di_bh); 270 out: 271 unlock_page(page); 272 273 brelse(di_bh); 274 return ret; 275 } 276 277 static int ocfs2_readpage(struct file *file, struct page *page) 278 { 279 struct inode *inode = page->mapping->host; 280 struct ocfs2_inode_info *oi = OCFS2_I(inode); 281 loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT; 282 int ret, unlock = 1; 283 284 mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0)); 285 286 ret = ocfs2_inode_lock_with_page(inode, NULL, 0, page); 287 if (ret != 0) { 288 if (ret == AOP_TRUNCATED_PAGE) 289 unlock = 0; 290 mlog_errno(ret); 291 goto out; 292 } 293 294 if (down_read_trylock(&oi->ip_alloc_sem) == 0) { 295 ret = AOP_TRUNCATED_PAGE; 296 goto out_inode_unlock; 297 } 298 299 /* 300 * i_size might have just been updated as we grabed the meta lock. We 301 * might now be discovering a truncate that hit on another node. 302 * block_read_full_page->get_block freaks out if it is asked to read 303 * beyond the end of a file, so we check here. Callers 304 * (generic_file_read, vm_ops->fault) are clever enough to check i_size 305 * and notice that the page they just read isn't needed. 306 * 307 * XXX sys_readahead() seems to get that wrong? 308 */ 309 if (start >= i_size_read(inode)) { 310 zero_user(page, 0, PAGE_SIZE); 311 SetPageUptodate(page); 312 ret = 0; 313 goto out_alloc; 314 } 315 316 if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) 317 ret = ocfs2_readpage_inline(inode, page); 318 else 319 ret = block_read_full_page(page, ocfs2_get_block); 320 unlock = 0; 321 322 out_alloc: 323 up_read(&OCFS2_I(inode)->ip_alloc_sem); 324 out_inode_unlock: 325 ocfs2_inode_unlock(inode, 0); 326 out: 327 if (unlock) 328 unlock_page(page); 329 mlog_exit(ret); 330 return ret; 331 } 332 333 /* 334 * This is used only for read-ahead. Failures or difficult to handle 335 * situations are safe to ignore. 336 * 337 * Right now, we don't bother with BH_Boundary - in-inode extent lists 338 * are quite large (243 extents on 4k blocks), so most inodes don't 339 * grow out to a tree. If need be, detecting boundary extents could 340 * trivially be added in a future version of ocfs2_get_block(). 341 */ 342 static int ocfs2_readpages(struct file *filp, struct address_space *mapping, 343 struct list_head *pages, unsigned nr_pages) 344 { 345 int ret, err = -EIO; 346 struct inode *inode = mapping->host; 347 struct ocfs2_inode_info *oi = OCFS2_I(inode); 348 loff_t start; 349 struct page *last; 350 351 /* 352 * Use the nonblocking flag for the dlm code to avoid page 353 * lock inversion, but don't bother with retrying. 354 */ 355 ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK); 356 if (ret) 357 return err; 358 359 if (down_read_trylock(&oi->ip_alloc_sem) == 0) { 360 ocfs2_inode_unlock(inode, 0); 361 return err; 362 } 363 364 /* 365 * Don't bother with inline-data. There isn't anything 366 * to read-ahead in that case anyway... 367 */ 368 if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) 369 goto out_unlock; 370 371 /* 372 * Check whether a remote node truncated this file - we just 373 * drop out in that case as it's not worth handling here. 374 */ 375 last = list_entry(pages->prev, struct page, lru); 376 start = (loff_t)last->index << PAGE_CACHE_SHIFT; 377 if (start >= i_size_read(inode)) 378 goto out_unlock; 379 380 err = mpage_readpages(mapping, pages, nr_pages, ocfs2_get_block); 381 382 out_unlock: 383 up_read(&oi->ip_alloc_sem); 384 ocfs2_inode_unlock(inode, 0); 385 386 return err; 387 } 388 389 /* Note: Because we don't support holes, our allocation has 390 * already happened (allocation writes zeros to the file data) 391 * so we don't have to worry about ordered writes in 392 * ocfs2_writepage. 393 * 394 * ->writepage is called during the process of invalidating the page cache 395 * during blocked lock processing. It can't block on any cluster locks 396 * to during block mapping. It's relying on the fact that the block 397 * mapping can't have disappeared under the dirty pages that it is 398 * being asked to write back. 399 */ 400 static int ocfs2_writepage(struct page *page, struct writeback_control *wbc) 401 { 402 int ret; 403 404 mlog_entry("(0x%p)\n", page); 405 406 ret = block_write_full_page(page, ocfs2_get_block, wbc); 407 408 mlog_exit(ret); 409 410 return ret; 411 } 412 413 /* 414 * This is called from ocfs2_write_zero_page() which has handled it's 415 * own cluster locking and has ensured allocation exists for those 416 * blocks to be written. 417 */ 418 int ocfs2_prepare_write_nolock(struct inode *inode, struct page *page, 419 unsigned from, unsigned to) 420 { 421 int ret; 422 423 ret = block_prepare_write(page, from, to, ocfs2_get_block); 424 425 return ret; 426 } 427 428 /* Taken from ext3. We don't necessarily need the full blown 429 * functionality yet, but IMHO it's better to cut and paste the whole 430 * thing so we can avoid introducing our own bugs (and easily pick up 431 * their fixes when they happen) --Mark */ 432 int walk_page_buffers( handle_t *handle, 433 struct buffer_head *head, 434 unsigned from, 435 unsigned to, 436 int *partial, 437 int (*fn)( handle_t *handle, 438 struct buffer_head *bh)) 439 { 440 struct buffer_head *bh; 441 unsigned block_start, block_end; 442 unsigned blocksize = head->b_size; 443 int err, ret = 0; 444 struct buffer_head *next; 445 446 for ( bh = head, block_start = 0; 447 ret == 0 && (bh != head || !block_start); 448 block_start = block_end, bh = next) 449 { 450 next = bh->b_this_page; 451 block_end = block_start + blocksize; 452 if (block_end <= from || block_start >= to) { 453 if (partial && !buffer_uptodate(bh)) 454 *partial = 1; 455 continue; 456 } 457 err = (*fn)(handle, bh); 458 if (!ret) 459 ret = err; 460 } 461 return ret; 462 } 463 464 handle_t *ocfs2_start_walk_page_trans(struct inode *inode, 465 struct page *page, 466 unsigned from, 467 unsigned to) 468 { 469 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 470 handle_t *handle; 471 int ret = 0; 472 473 handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS); 474 if (IS_ERR(handle)) { 475 ret = -ENOMEM; 476 mlog_errno(ret); 477 goto out; 478 } 479 480 if (ocfs2_should_order_data(inode)) { 481 ret = walk_page_buffers(handle, 482 page_buffers(page), 483 from, to, NULL, 484 ocfs2_journal_dirty_data); 485 if (ret < 0) 486 mlog_errno(ret); 487 } 488 out: 489 if (ret) { 490 if (!IS_ERR(handle)) 491 ocfs2_commit_trans(osb, handle); 492 handle = ERR_PTR(ret); 493 } 494 return handle; 495 } 496 497 static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block) 498 { 499 sector_t status; 500 u64 p_blkno = 0; 501 int err = 0; 502 struct inode *inode = mapping->host; 503 504 mlog_entry("(block = %llu)\n", (unsigned long long)block); 505 506 /* We don't need to lock journal system files, since they aren't 507 * accessed concurrently from multiple nodes. 508 */ 509 if (!INODE_JOURNAL(inode)) { 510 err = ocfs2_inode_lock(inode, NULL, 0); 511 if (err) { 512 if (err != -ENOENT) 513 mlog_errno(err); 514 goto bail; 515 } 516 down_read(&OCFS2_I(inode)->ip_alloc_sem); 517 } 518 519 if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)) 520 err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL, 521 NULL); 522 523 if (!INODE_JOURNAL(inode)) { 524 up_read(&OCFS2_I(inode)->ip_alloc_sem); 525 ocfs2_inode_unlock(inode, 0); 526 } 527 528 if (err) { 529 mlog(ML_ERROR, "get_blocks() failed, block = %llu\n", 530 (unsigned long long)block); 531 mlog_errno(err); 532 goto bail; 533 } 534 535 bail: 536 status = err ? 0 : p_blkno; 537 538 mlog_exit((int)status); 539 540 return status; 541 } 542 543 /* 544 * TODO: Make this into a generic get_blocks function. 545 * 546 * From do_direct_io in direct-io.c: 547 * "So what we do is to permit the ->get_blocks function to populate 548 * bh.b_size with the size of IO which is permitted at this offset and 549 * this i_blkbits." 550 * 551 * This function is called directly from get_more_blocks in direct-io.c. 552 * 553 * called like this: dio->get_blocks(dio->inode, fs_startblk, 554 * fs_count, map_bh, dio->rw == WRITE); 555 */ 556 static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock, 557 struct buffer_head *bh_result, int create) 558 { 559 int ret; 560 u64 p_blkno, inode_blocks, contig_blocks; 561 unsigned int ext_flags; 562 unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits; 563 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 564 565 /* This function won't even be called if the request isn't all 566 * nicely aligned and of the right size, so there's no need 567 * for us to check any of that. */ 568 569 inode_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode)); 570 571 /* 572 * Any write past EOF is not allowed because we'd be extending. 573 */ 574 if (create && (iblock + max_blocks) > inode_blocks) { 575 ret = -EIO; 576 goto bail; 577 } 578 579 /* This figures out the size of the next contiguous block, and 580 * our logical offset */ 581 ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, 582 &contig_blocks, &ext_flags); 583 if (ret) { 584 mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n", 585 (unsigned long long)iblock); 586 ret = -EIO; 587 goto bail; 588 } 589 590 if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)) && !p_blkno) { 591 ocfs2_error(inode->i_sb, 592 "Inode %llu has a hole at block %llu\n", 593 (unsigned long long)OCFS2_I(inode)->ip_blkno, 594 (unsigned long long)iblock); 595 ret = -EROFS; 596 goto bail; 597 } 598 599 /* 600 * get_more_blocks() expects us to describe a hole by clearing 601 * the mapped bit on bh_result(). 602 * 603 * Consider an unwritten extent as a hole. 604 */ 605 if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN)) 606 map_bh(bh_result, inode->i_sb, p_blkno); 607 else { 608 /* 609 * ocfs2_prepare_inode_for_write() should have caught 610 * the case where we'd be filling a hole and triggered 611 * a buffered write instead. 612 */ 613 if (create) { 614 ret = -EIO; 615 mlog_errno(ret); 616 goto bail; 617 } 618 619 clear_buffer_mapped(bh_result); 620 } 621 622 /* make sure we don't map more than max_blocks blocks here as 623 that's all the kernel will handle at this point. */ 624 if (max_blocks < contig_blocks) 625 contig_blocks = max_blocks; 626 bh_result->b_size = contig_blocks << blocksize_bits; 627 bail: 628 return ret; 629 } 630 631 /* 632 * ocfs2_dio_end_io is called by the dio core when a dio is finished. We're 633 * particularly interested in the aio/dio case. Like the core uses 634 * i_alloc_sem, we use the rw_lock DLM lock to protect io on one node from 635 * truncation on another. 636 */ 637 static void ocfs2_dio_end_io(struct kiocb *iocb, 638 loff_t offset, 639 ssize_t bytes, 640 void *private) 641 { 642 struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode; 643 int level; 644 645 /* this io's submitter should not have unlocked this before we could */ 646 BUG_ON(!ocfs2_iocb_is_rw_locked(iocb)); 647 648 ocfs2_iocb_clear_rw_locked(iocb); 649 650 level = ocfs2_iocb_rw_locked_level(iocb); 651 if (!level) 652 up_read(&inode->i_alloc_sem); 653 ocfs2_rw_unlock(inode, level); 654 } 655 656 /* 657 * ocfs2_invalidatepage() and ocfs2_releasepage() are shamelessly stolen 658 * from ext3. PageChecked() bits have been removed as OCFS2 does not 659 * do journalled data. 660 */ 661 static void ocfs2_invalidatepage(struct page *page, unsigned long offset) 662 { 663 journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal; 664 665 journal_invalidatepage(journal, page, offset); 666 } 667 668 static int ocfs2_releasepage(struct page *page, gfp_t wait) 669 { 670 journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal; 671 672 if (!page_has_buffers(page)) 673 return 0; 674 return journal_try_to_free_buffers(journal, page, wait); 675 } 676 677 static ssize_t ocfs2_direct_IO(int rw, 678 struct kiocb *iocb, 679 const struct iovec *iov, 680 loff_t offset, 681 unsigned long nr_segs) 682 { 683 struct file *file = iocb->ki_filp; 684 struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host; 685 int ret; 686 687 mlog_entry_void(); 688 689 /* 690 * Fallback to buffered I/O if we see an inode without 691 * extents. 692 */ 693 if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) 694 return 0; 695 696 ret = blockdev_direct_IO_no_locking(rw, iocb, inode, 697 inode->i_sb->s_bdev, iov, offset, 698 nr_segs, 699 ocfs2_direct_IO_get_blocks, 700 ocfs2_dio_end_io); 701 702 mlog_exit(ret); 703 return ret; 704 } 705 706 static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb, 707 u32 cpos, 708 unsigned int *start, 709 unsigned int *end) 710 { 711 unsigned int cluster_start = 0, cluster_end = PAGE_CACHE_SIZE; 712 713 if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) { 714 unsigned int cpp; 715 716 cpp = 1 << (PAGE_CACHE_SHIFT - osb->s_clustersize_bits); 717 718 cluster_start = cpos % cpp; 719 cluster_start = cluster_start << osb->s_clustersize_bits; 720 721 cluster_end = cluster_start + osb->s_clustersize; 722 } 723 724 BUG_ON(cluster_start > PAGE_SIZE); 725 BUG_ON(cluster_end > PAGE_SIZE); 726 727 if (start) 728 *start = cluster_start; 729 if (end) 730 *end = cluster_end; 731 } 732 733 /* 734 * 'from' and 'to' are the region in the page to avoid zeroing. 735 * 736 * If pagesize > clustersize, this function will avoid zeroing outside 737 * of the cluster boundary. 738 * 739 * from == to == 0 is code for "zero the entire cluster region" 740 */ 741 static void ocfs2_clear_page_regions(struct page *page, 742 struct ocfs2_super *osb, u32 cpos, 743 unsigned from, unsigned to) 744 { 745 void *kaddr; 746 unsigned int cluster_start, cluster_end; 747 748 ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end); 749 750 kaddr = kmap_atomic(page, KM_USER0); 751 752 if (from || to) { 753 if (from > cluster_start) 754 memset(kaddr + cluster_start, 0, from - cluster_start); 755 if (to < cluster_end) 756 memset(kaddr + to, 0, cluster_end - to); 757 } else { 758 memset(kaddr + cluster_start, 0, cluster_end - cluster_start); 759 } 760 761 kunmap_atomic(kaddr, KM_USER0); 762 } 763 764 /* 765 * Nonsparse file systems fully allocate before we get to the write 766 * code. This prevents ocfs2_write() from tagging the write as an 767 * allocating one, which means ocfs2_map_page_blocks() might try to 768 * read-in the blocks at the tail of our file. Avoid reading them by 769 * testing i_size against each block offset. 770 */ 771 static int ocfs2_should_read_blk(struct inode *inode, struct page *page, 772 unsigned int block_start) 773 { 774 u64 offset = page_offset(page) + block_start; 775 776 if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) 777 return 1; 778 779 if (i_size_read(inode) > offset) 780 return 1; 781 782 return 0; 783 } 784 785 /* 786 * Some of this taken from block_prepare_write(). We already have our 787 * mapping by now though, and the entire write will be allocating or 788 * it won't, so not much need to use BH_New. 789 * 790 * This will also skip zeroing, which is handled externally. 791 */ 792 int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno, 793 struct inode *inode, unsigned int from, 794 unsigned int to, int new) 795 { 796 int ret = 0; 797 struct buffer_head *head, *bh, *wait[2], **wait_bh = wait; 798 unsigned int block_end, block_start; 799 unsigned int bsize = 1 << inode->i_blkbits; 800 801 if (!page_has_buffers(page)) 802 create_empty_buffers(page, bsize, 0); 803 804 head = page_buffers(page); 805 for (bh = head, block_start = 0; bh != head || !block_start; 806 bh = bh->b_this_page, block_start += bsize) { 807 block_end = block_start + bsize; 808 809 clear_buffer_new(bh); 810 811 /* 812 * Ignore blocks outside of our i/o range - 813 * they may belong to unallocated clusters. 814 */ 815 if (block_start >= to || block_end <= from) { 816 if (PageUptodate(page)) 817 set_buffer_uptodate(bh); 818 continue; 819 } 820 821 /* 822 * For an allocating write with cluster size >= page 823 * size, we always write the entire page. 824 */ 825 if (new) 826 set_buffer_new(bh); 827 828 if (!buffer_mapped(bh)) { 829 map_bh(bh, inode->i_sb, *p_blkno); 830 unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); 831 } 832 833 if (PageUptodate(page)) { 834 if (!buffer_uptodate(bh)) 835 set_buffer_uptodate(bh); 836 } else if (!buffer_uptodate(bh) && !buffer_delay(bh) && 837 !buffer_new(bh) && 838 ocfs2_should_read_blk(inode, page, block_start) && 839 (block_start < from || block_end > to)) { 840 ll_rw_block(READ, 1, &bh); 841 *wait_bh++=bh; 842 } 843 844 *p_blkno = *p_blkno + 1; 845 } 846 847 /* 848 * If we issued read requests - let them complete. 849 */ 850 while(wait_bh > wait) { 851 wait_on_buffer(*--wait_bh); 852 if (!buffer_uptodate(*wait_bh)) 853 ret = -EIO; 854 } 855 856 if (ret == 0 || !new) 857 return ret; 858 859 /* 860 * If we get -EIO above, zero out any newly allocated blocks 861 * to avoid exposing stale data. 862 */ 863 bh = head; 864 block_start = 0; 865 do { 866 block_end = block_start + bsize; 867 if (block_end <= from) 868 goto next_bh; 869 if (block_start >= to) 870 break; 871 872 zero_user(page, block_start, bh->b_size); 873 set_buffer_uptodate(bh); 874 mark_buffer_dirty(bh); 875 876 next_bh: 877 block_start = block_end; 878 bh = bh->b_this_page; 879 } while (bh != head); 880 881 return ret; 882 } 883 884 #if (PAGE_CACHE_SIZE >= OCFS2_MAX_CLUSTERSIZE) 885 #define OCFS2_MAX_CTXT_PAGES 1 886 #else 887 #define OCFS2_MAX_CTXT_PAGES (OCFS2_MAX_CLUSTERSIZE / PAGE_CACHE_SIZE) 888 #endif 889 890 #define OCFS2_MAX_CLUSTERS_PER_PAGE (PAGE_CACHE_SIZE / OCFS2_MIN_CLUSTERSIZE) 891 892 /* 893 * Describe the state of a single cluster to be written to. 894 */ 895 struct ocfs2_write_cluster_desc { 896 u32 c_cpos; 897 u32 c_phys; 898 /* 899 * Give this a unique field because c_phys eventually gets 900 * filled. 901 */ 902 unsigned c_new; 903 unsigned c_unwritten; 904 }; 905 906 static inline int ocfs2_should_zero_cluster(struct ocfs2_write_cluster_desc *d) 907 { 908 return d->c_new || d->c_unwritten; 909 } 910 911 struct ocfs2_write_ctxt { 912 /* Logical cluster position / len of write */ 913 u32 w_cpos; 914 u32 w_clen; 915 916 struct ocfs2_write_cluster_desc w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE]; 917 918 /* 919 * This is true if page_size > cluster_size. 920 * 921 * It triggers a set of special cases during write which might 922 * have to deal with allocating writes to partial pages. 923 */ 924 unsigned int w_large_pages; 925 926 /* 927 * Pages involved in this write. 928 * 929 * w_target_page is the page being written to by the user. 930 * 931 * w_pages is an array of pages which always contains 932 * w_target_page, and in the case of an allocating write with 933 * page_size < cluster size, it will contain zero'd and mapped 934 * pages adjacent to w_target_page which need to be written 935 * out in so that future reads from that region will get 936 * zero's. 937 */ 938 struct page *w_pages[OCFS2_MAX_CTXT_PAGES]; 939 unsigned int w_num_pages; 940 struct page *w_target_page; 941 942 /* 943 * ocfs2_write_end() uses this to know what the real range to 944 * write in the target should be. 945 */ 946 unsigned int w_target_from; 947 unsigned int w_target_to; 948 949 /* 950 * We could use journal_current_handle() but this is cleaner, 951 * IMHO -Mark 952 */ 953 handle_t *w_handle; 954 955 struct buffer_head *w_di_bh; 956 957 struct ocfs2_cached_dealloc_ctxt w_dealloc; 958 }; 959 960 void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages) 961 { 962 int i; 963 964 for(i = 0; i < num_pages; i++) { 965 if (pages[i]) { 966 unlock_page(pages[i]); 967 mark_page_accessed(pages[i]); 968 page_cache_release(pages[i]); 969 } 970 } 971 } 972 973 static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc) 974 { 975 ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages); 976 977 brelse(wc->w_di_bh); 978 kfree(wc); 979 } 980 981 static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp, 982 struct ocfs2_super *osb, loff_t pos, 983 unsigned len, struct buffer_head *di_bh) 984 { 985 u32 cend; 986 struct ocfs2_write_ctxt *wc; 987 988 wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS); 989 if (!wc) 990 return -ENOMEM; 991 992 wc->w_cpos = pos >> osb->s_clustersize_bits; 993 cend = (pos + len - 1) >> osb->s_clustersize_bits; 994 wc->w_clen = cend - wc->w_cpos + 1; 995 get_bh(di_bh); 996 wc->w_di_bh = di_bh; 997 998 if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) 999 wc->w_large_pages = 1; 1000 else 1001 wc->w_large_pages = 0; 1002 1003 ocfs2_init_dealloc_ctxt(&wc->w_dealloc); 1004 1005 *wcp = wc; 1006 1007 return 0; 1008 } 1009 1010 /* 1011 * If a page has any new buffers, zero them out here, and mark them uptodate 1012 * and dirty so they'll be written out (in order to prevent uninitialised 1013 * block data from leaking). And clear the new bit. 1014 */ 1015 static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to) 1016 { 1017 unsigned int block_start, block_end; 1018 struct buffer_head *head, *bh; 1019 1020 BUG_ON(!PageLocked(page)); 1021 if (!page_has_buffers(page)) 1022 return; 1023 1024 bh = head = page_buffers(page); 1025 block_start = 0; 1026 do { 1027 block_end = block_start + bh->b_size; 1028 1029 if (buffer_new(bh)) { 1030 if (block_end > from && block_start < to) { 1031 if (!PageUptodate(page)) { 1032 unsigned start, end; 1033 1034 start = max(from, block_start); 1035 end = min(to, block_end); 1036 1037 zero_user_segment(page, start, end); 1038 set_buffer_uptodate(bh); 1039 } 1040 1041 clear_buffer_new(bh); 1042 mark_buffer_dirty(bh); 1043 } 1044 } 1045 1046 block_start = block_end; 1047 bh = bh->b_this_page; 1048 } while (bh != head); 1049 } 1050 1051 /* 1052 * Only called when we have a failure during allocating write to write 1053 * zero's to the newly allocated region. 1054 */ 1055 static void ocfs2_write_failure(struct inode *inode, 1056 struct ocfs2_write_ctxt *wc, 1057 loff_t user_pos, unsigned user_len) 1058 { 1059 int i; 1060 unsigned from = user_pos & (PAGE_CACHE_SIZE - 1), 1061 to = user_pos + user_len; 1062 struct page *tmppage; 1063 1064 ocfs2_zero_new_buffers(wc->w_target_page, from, to); 1065 1066 for(i = 0; i < wc->w_num_pages; i++) { 1067 tmppage = wc->w_pages[i]; 1068 1069 if (ocfs2_should_order_data(inode)) 1070 walk_page_buffers(wc->w_handle, page_buffers(tmppage), 1071 from, to, NULL, 1072 ocfs2_journal_dirty_data); 1073 1074 block_commit_write(tmppage, from, to); 1075 } 1076 } 1077 1078 static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno, 1079 struct ocfs2_write_ctxt *wc, 1080 struct page *page, u32 cpos, 1081 loff_t user_pos, unsigned user_len, 1082 int new) 1083 { 1084 int ret; 1085 unsigned int map_from = 0, map_to = 0; 1086 unsigned int cluster_start, cluster_end; 1087 unsigned int user_data_from = 0, user_data_to = 0; 1088 1089 ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos, 1090 &cluster_start, &cluster_end); 1091 1092 if (page == wc->w_target_page) { 1093 map_from = user_pos & (PAGE_CACHE_SIZE - 1); 1094 map_to = map_from + user_len; 1095 1096 if (new) 1097 ret = ocfs2_map_page_blocks(page, p_blkno, inode, 1098 cluster_start, cluster_end, 1099 new); 1100 else 1101 ret = ocfs2_map_page_blocks(page, p_blkno, inode, 1102 map_from, map_to, new); 1103 if (ret) { 1104 mlog_errno(ret); 1105 goto out; 1106 } 1107 1108 user_data_from = map_from; 1109 user_data_to = map_to; 1110 if (new) { 1111 map_from = cluster_start; 1112 map_to = cluster_end; 1113 } 1114 } else { 1115 /* 1116 * If we haven't allocated the new page yet, we 1117 * shouldn't be writing it out without copying user 1118 * data. This is likely a math error from the caller. 1119 */ 1120 BUG_ON(!new); 1121 1122 map_from = cluster_start; 1123 map_to = cluster_end; 1124 1125 ret = ocfs2_map_page_blocks(page, p_blkno, inode, 1126 cluster_start, cluster_end, new); 1127 if (ret) { 1128 mlog_errno(ret); 1129 goto out; 1130 } 1131 } 1132 1133 /* 1134 * Parts of newly allocated pages need to be zero'd. 1135 * 1136 * Above, we have also rewritten 'to' and 'from' - as far as 1137 * the rest of the function is concerned, the entire cluster 1138 * range inside of a page needs to be written. 1139 * 1140 * We can skip this if the page is up to date - it's already 1141 * been zero'd from being read in as a hole. 1142 */ 1143 if (new && !PageUptodate(page)) 1144 ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb), 1145 cpos, user_data_from, user_data_to); 1146 1147 flush_dcache_page(page); 1148 1149 out: 1150 return ret; 1151 } 1152 1153 /* 1154 * This function will only grab one clusters worth of pages. 1155 */ 1156 static int ocfs2_grab_pages_for_write(struct address_space *mapping, 1157 struct ocfs2_write_ctxt *wc, 1158 u32 cpos, loff_t user_pos, int new, 1159 struct page *mmap_page) 1160 { 1161 int ret = 0, i; 1162 unsigned long start, target_index, index; 1163 struct inode *inode = mapping->host; 1164 1165 target_index = user_pos >> PAGE_CACHE_SHIFT; 1166 1167 /* 1168 * Figure out how many pages we'll be manipulating here. For 1169 * non allocating write, we just change the one 1170 * page. Otherwise, we'll need a whole clusters worth. 1171 */ 1172 if (new) { 1173 wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb); 1174 start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos); 1175 } else { 1176 wc->w_num_pages = 1; 1177 start = target_index; 1178 } 1179 1180 for(i = 0; i < wc->w_num_pages; i++) { 1181 index = start + i; 1182 1183 if (index == target_index && mmap_page) { 1184 /* 1185 * ocfs2_pagemkwrite() is a little different 1186 * and wants us to directly use the page 1187 * passed in. 1188 */ 1189 lock_page(mmap_page); 1190 1191 if (mmap_page->mapping != mapping) { 1192 unlock_page(mmap_page); 1193 /* 1194 * Sanity check - the locking in 1195 * ocfs2_pagemkwrite() should ensure 1196 * that this code doesn't trigger. 1197 */ 1198 ret = -EINVAL; 1199 mlog_errno(ret); 1200 goto out; 1201 } 1202 1203 page_cache_get(mmap_page); 1204 wc->w_pages[i] = mmap_page; 1205 } else { 1206 wc->w_pages[i] = find_or_create_page(mapping, index, 1207 GFP_NOFS); 1208 if (!wc->w_pages[i]) { 1209 ret = -ENOMEM; 1210 mlog_errno(ret); 1211 goto out; 1212 } 1213 } 1214 1215 if (index == target_index) 1216 wc->w_target_page = wc->w_pages[i]; 1217 } 1218 out: 1219 return ret; 1220 } 1221 1222 /* 1223 * Prepare a single cluster for write one cluster into the file. 1224 */ 1225 static int ocfs2_write_cluster(struct address_space *mapping, 1226 u32 phys, unsigned int unwritten, 1227 struct ocfs2_alloc_context *data_ac, 1228 struct ocfs2_alloc_context *meta_ac, 1229 struct ocfs2_write_ctxt *wc, u32 cpos, 1230 loff_t user_pos, unsigned user_len) 1231 { 1232 int ret, i, new, should_zero = 0; 1233 u64 v_blkno, p_blkno; 1234 struct inode *inode = mapping->host; 1235 1236 new = phys == 0 ? 1 : 0; 1237 if (new || unwritten) 1238 should_zero = 1; 1239 1240 if (new) { 1241 u32 tmp_pos; 1242 1243 /* 1244 * This is safe to call with the page locks - it won't take 1245 * any additional semaphores or cluster locks. 1246 */ 1247 tmp_pos = cpos; 1248 ret = ocfs2_do_extend_allocation(OCFS2_SB(inode->i_sb), inode, 1249 &tmp_pos, 1, 0, wc->w_di_bh, 1250 wc->w_handle, data_ac, 1251 meta_ac, NULL); 1252 /* 1253 * This shouldn't happen because we must have already 1254 * calculated the correct meta data allocation required. The 1255 * internal tree allocation code should know how to increase 1256 * transaction credits itself. 1257 * 1258 * If need be, we could handle -EAGAIN for a 1259 * RESTART_TRANS here. 1260 */ 1261 mlog_bug_on_msg(ret == -EAGAIN, 1262 "Inode %llu: EAGAIN return during allocation.\n", 1263 (unsigned long long)OCFS2_I(inode)->ip_blkno); 1264 if (ret < 0) { 1265 mlog_errno(ret); 1266 goto out; 1267 } 1268 } else if (unwritten) { 1269 ret = ocfs2_mark_extent_written(inode, wc->w_di_bh, 1270 wc->w_handle, cpos, 1, phys, 1271 meta_ac, &wc->w_dealloc); 1272 if (ret < 0) { 1273 mlog_errno(ret); 1274 goto out; 1275 } 1276 } 1277 1278 if (should_zero) 1279 v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, cpos); 1280 else 1281 v_blkno = user_pos >> inode->i_sb->s_blocksize_bits; 1282 1283 /* 1284 * The only reason this should fail is due to an inability to 1285 * find the extent added. 1286 */ 1287 ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL, 1288 NULL); 1289 if (ret < 0) { 1290 ocfs2_error(inode->i_sb, "Corrupting extend for inode %llu, " 1291 "at logical block %llu", 1292 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1293 (unsigned long long)v_blkno); 1294 goto out; 1295 } 1296 1297 BUG_ON(p_blkno == 0); 1298 1299 for(i = 0; i < wc->w_num_pages; i++) { 1300 int tmpret; 1301 1302 tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc, 1303 wc->w_pages[i], cpos, 1304 user_pos, user_len, 1305 should_zero); 1306 if (tmpret) { 1307 mlog_errno(tmpret); 1308 if (ret == 0) 1309 tmpret = ret; 1310 } 1311 } 1312 1313 /* 1314 * We only have cleanup to do in case of allocating write. 1315 */ 1316 if (ret && new) 1317 ocfs2_write_failure(inode, wc, user_pos, user_len); 1318 1319 out: 1320 1321 return ret; 1322 } 1323 1324 static int ocfs2_write_cluster_by_desc(struct address_space *mapping, 1325 struct ocfs2_alloc_context *data_ac, 1326 struct ocfs2_alloc_context *meta_ac, 1327 struct ocfs2_write_ctxt *wc, 1328 loff_t pos, unsigned len) 1329 { 1330 int ret, i; 1331 loff_t cluster_off; 1332 unsigned int local_len = len; 1333 struct ocfs2_write_cluster_desc *desc; 1334 struct ocfs2_super *osb = OCFS2_SB(mapping->host->i_sb); 1335 1336 for (i = 0; i < wc->w_clen; i++) { 1337 desc = &wc->w_desc[i]; 1338 1339 /* 1340 * We have to make sure that the total write passed in 1341 * doesn't extend past a single cluster. 1342 */ 1343 local_len = len; 1344 cluster_off = pos & (osb->s_clustersize - 1); 1345 if ((cluster_off + local_len) > osb->s_clustersize) 1346 local_len = osb->s_clustersize - cluster_off; 1347 1348 ret = ocfs2_write_cluster(mapping, desc->c_phys, 1349 desc->c_unwritten, data_ac, meta_ac, 1350 wc, desc->c_cpos, pos, local_len); 1351 if (ret) { 1352 mlog_errno(ret); 1353 goto out; 1354 } 1355 1356 len -= local_len; 1357 pos += local_len; 1358 } 1359 1360 ret = 0; 1361 out: 1362 return ret; 1363 } 1364 1365 /* 1366 * ocfs2_write_end() wants to know which parts of the target page it 1367 * should complete the write on. It's easiest to compute them ahead of 1368 * time when a more complete view of the write is available. 1369 */ 1370 static void ocfs2_set_target_boundaries(struct ocfs2_super *osb, 1371 struct ocfs2_write_ctxt *wc, 1372 loff_t pos, unsigned len, int alloc) 1373 { 1374 struct ocfs2_write_cluster_desc *desc; 1375 1376 wc->w_target_from = pos & (PAGE_CACHE_SIZE - 1); 1377 wc->w_target_to = wc->w_target_from + len; 1378 1379 if (alloc == 0) 1380 return; 1381 1382 /* 1383 * Allocating write - we may have different boundaries based 1384 * on page size and cluster size. 1385 * 1386 * NOTE: We can no longer compute one value from the other as 1387 * the actual write length and user provided length may be 1388 * different. 1389 */ 1390 1391 if (wc->w_large_pages) { 1392 /* 1393 * We only care about the 1st and last cluster within 1394 * our range and whether they should be zero'd or not. Either 1395 * value may be extended out to the start/end of a 1396 * newly allocated cluster. 1397 */ 1398 desc = &wc->w_desc[0]; 1399 if (ocfs2_should_zero_cluster(desc)) 1400 ocfs2_figure_cluster_boundaries(osb, 1401 desc->c_cpos, 1402 &wc->w_target_from, 1403 NULL); 1404 1405 desc = &wc->w_desc[wc->w_clen - 1]; 1406 if (ocfs2_should_zero_cluster(desc)) 1407 ocfs2_figure_cluster_boundaries(osb, 1408 desc->c_cpos, 1409 NULL, 1410 &wc->w_target_to); 1411 } else { 1412 wc->w_target_from = 0; 1413 wc->w_target_to = PAGE_CACHE_SIZE; 1414 } 1415 } 1416 1417 /* 1418 * Populate each single-cluster write descriptor in the write context 1419 * with information about the i/o to be done. 1420 * 1421 * Returns the number of clusters that will have to be allocated, as 1422 * well as a worst case estimate of the number of extent records that 1423 * would have to be created during a write to an unwritten region. 1424 */ 1425 static int ocfs2_populate_write_desc(struct inode *inode, 1426 struct ocfs2_write_ctxt *wc, 1427 unsigned int *clusters_to_alloc, 1428 unsigned int *extents_to_split) 1429 { 1430 int ret; 1431 struct ocfs2_write_cluster_desc *desc; 1432 unsigned int num_clusters = 0; 1433 unsigned int ext_flags = 0; 1434 u32 phys = 0; 1435 int i; 1436 1437 *clusters_to_alloc = 0; 1438 *extents_to_split = 0; 1439 1440 for (i = 0; i < wc->w_clen; i++) { 1441 desc = &wc->w_desc[i]; 1442 desc->c_cpos = wc->w_cpos + i; 1443 1444 if (num_clusters == 0) { 1445 /* 1446 * Need to look up the next extent record. 1447 */ 1448 ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys, 1449 &num_clusters, &ext_flags); 1450 if (ret) { 1451 mlog_errno(ret); 1452 goto out; 1453 } 1454 1455 /* 1456 * Assume worst case - that we're writing in 1457 * the middle of the extent. 1458 * 1459 * We can assume that the write proceeds from 1460 * left to right, in which case the extent 1461 * insert code is smart enough to coalesce the 1462 * next splits into the previous records created. 1463 */ 1464 if (ext_flags & OCFS2_EXT_UNWRITTEN) 1465 *extents_to_split = *extents_to_split + 2; 1466 } else if (phys) { 1467 /* 1468 * Only increment phys if it doesn't describe 1469 * a hole. 1470 */ 1471 phys++; 1472 } 1473 1474 desc->c_phys = phys; 1475 if (phys == 0) { 1476 desc->c_new = 1; 1477 *clusters_to_alloc = *clusters_to_alloc + 1; 1478 } 1479 if (ext_flags & OCFS2_EXT_UNWRITTEN) 1480 desc->c_unwritten = 1; 1481 1482 num_clusters--; 1483 } 1484 1485 ret = 0; 1486 out: 1487 return ret; 1488 } 1489 1490 static int ocfs2_write_begin_inline(struct address_space *mapping, 1491 struct inode *inode, 1492 struct ocfs2_write_ctxt *wc) 1493 { 1494 int ret; 1495 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1496 struct page *page; 1497 handle_t *handle; 1498 struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data; 1499 1500 page = find_or_create_page(mapping, 0, GFP_NOFS); 1501 if (!page) { 1502 ret = -ENOMEM; 1503 mlog_errno(ret); 1504 goto out; 1505 } 1506 /* 1507 * If we don't set w_num_pages then this page won't get unlocked 1508 * and freed on cleanup of the write context. 1509 */ 1510 wc->w_pages[0] = wc->w_target_page = page; 1511 wc->w_num_pages = 1; 1512 1513 handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS); 1514 if (IS_ERR(handle)) { 1515 ret = PTR_ERR(handle); 1516 mlog_errno(ret); 1517 goto out; 1518 } 1519 1520 ret = ocfs2_journal_access(handle, inode, wc->w_di_bh, 1521 OCFS2_JOURNAL_ACCESS_WRITE); 1522 if (ret) { 1523 ocfs2_commit_trans(osb, handle); 1524 1525 mlog_errno(ret); 1526 goto out; 1527 } 1528 1529 if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)) 1530 ocfs2_set_inode_data_inline(inode, di); 1531 1532 if (!PageUptodate(page)) { 1533 ret = ocfs2_read_inline_data(inode, page, wc->w_di_bh); 1534 if (ret) { 1535 ocfs2_commit_trans(osb, handle); 1536 1537 goto out; 1538 } 1539 } 1540 1541 wc->w_handle = handle; 1542 out: 1543 return ret; 1544 } 1545 1546 int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size) 1547 { 1548 struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data; 1549 1550 if (new_size <= le16_to_cpu(di->id2.i_data.id_count)) 1551 return 1; 1552 return 0; 1553 } 1554 1555 static int ocfs2_try_to_write_inline_data(struct address_space *mapping, 1556 struct inode *inode, loff_t pos, 1557 unsigned len, struct page *mmap_page, 1558 struct ocfs2_write_ctxt *wc) 1559 { 1560 int ret, written = 0; 1561 loff_t end = pos + len; 1562 struct ocfs2_inode_info *oi = OCFS2_I(inode); 1563 1564 mlog(0, "Inode %llu, write of %u bytes at off %llu. features: 0x%x\n", 1565 (unsigned long long)oi->ip_blkno, len, (unsigned long long)pos, 1566 oi->ip_dyn_features); 1567 1568 /* 1569 * Handle inodes which already have inline data 1st. 1570 */ 1571 if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) { 1572 if (mmap_page == NULL && 1573 ocfs2_size_fits_inline_data(wc->w_di_bh, end)) 1574 goto do_inline_write; 1575 1576 /* 1577 * The write won't fit - we have to give this inode an 1578 * inline extent list now. 1579 */ 1580 ret = ocfs2_convert_inline_data_to_extents(inode, wc->w_di_bh); 1581 if (ret) 1582 mlog_errno(ret); 1583 goto out; 1584 } 1585 1586 /* 1587 * Check whether the inode can accept inline data. 1588 */ 1589 if (oi->ip_clusters != 0 || i_size_read(inode) != 0) 1590 return 0; 1591 1592 /* 1593 * Check whether the write can fit. 1594 */ 1595 if (mmap_page || end > ocfs2_max_inline_data(inode->i_sb)) 1596 return 0; 1597 1598 do_inline_write: 1599 ret = ocfs2_write_begin_inline(mapping, inode, wc); 1600 if (ret) { 1601 mlog_errno(ret); 1602 goto out; 1603 } 1604 1605 /* 1606 * This signals to the caller that the data can be written 1607 * inline. 1608 */ 1609 written = 1; 1610 out: 1611 return written ? written : ret; 1612 } 1613 1614 /* 1615 * This function only does anything for file systems which can't 1616 * handle sparse files. 1617 * 1618 * What we want to do here is fill in any hole between the current end 1619 * of allocation and the end of our write. That way the rest of the 1620 * write path can treat it as an non-allocating write, which has no 1621 * special case code for sparse/nonsparse files. 1622 */ 1623 static int ocfs2_expand_nonsparse_inode(struct inode *inode, loff_t pos, 1624 unsigned len, 1625 struct ocfs2_write_ctxt *wc) 1626 { 1627 int ret; 1628 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1629 loff_t newsize = pos + len; 1630 1631 if (ocfs2_sparse_alloc(osb)) 1632 return 0; 1633 1634 if (newsize <= i_size_read(inode)) 1635 return 0; 1636 1637 ret = ocfs2_extend_no_holes(inode, newsize, newsize - len); 1638 if (ret) 1639 mlog_errno(ret); 1640 1641 return ret; 1642 } 1643 1644 int ocfs2_write_begin_nolock(struct address_space *mapping, 1645 loff_t pos, unsigned len, unsigned flags, 1646 struct page **pagep, void **fsdata, 1647 struct buffer_head *di_bh, struct page *mmap_page) 1648 { 1649 int ret, credits = OCFS2_INODE_UPDATE_CREDITS; 1650 unsigned int clusters_to_alloc, extents_to_split; 1651 struct ocfs2_write_ctxt *wc; 1652 struct inode *inode = mapping->host; 1653 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1654 struct ocfs2_dinode *di; 1655 struct ocfs2_alloc_context *data_ac = NULL; 1656 struct ocfs2_alloc_context *meta_ac = NULL; 1657 handle_t *handle; 1658 1659 ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, di_bh); 1660 if (ret) { 1661 mlog_errno(ret); 1662 return ret; 1663 } 1664 1665 if (ocfs2_supports_inline_data(osb)) { 1666 ret = ocfs2_try_to_write_inline_data(mapping, inode, pos, len, 1667 mmap_page, wc); 1668 if (ret == 1) { 1669 ret = 0; 1670 goto success; 1671 } 1672 if (ret < 0) { 1673 mlog_errno(ret); 1674 goto out; 1675 } 1676 } 1677 1678 ret = ocfs2_expand_nonsparse_inode(inode, pos, len, wc); 1679 if (ret) { 1680 mlog_errno(ret); 1681 goto out; 1682 } 1683 1684 ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc, 1685 &extents_to_split); 1686 if (ret) { 1687 mlog_errno(ret); 1688 goto out; 1689 } 1690 1691 di = (struct ocfs2_dinode *)wc->w_di_bh->b_data; 1692 1693 /* 1694 * We set w_target_from, w_target_to here so that 1695 * ocfs2_write_end() knows which range in the target page to 1696 * write out. An allocation requires that we write the entire 1697 * cluster range. 1698 */ 1699 if (clusters_to_alloc || extents_to_split) { 1700 /* 1701 * XXX: We are stretching the limits of 1702 * ocfs2_lock_allocators(). It greatly over-estimates 1703 * the work to be done. 1704 */ 1705 ret = ocfs2_lock_allocators(inode, di, clusters_to_alloc, 1706 extents_to_split, &data_ac, &meta_ac); 1707 if (ret) { 1708 mlog_errno(ret); 1709 goto out; 1710 } 1711 1712 credits = ocfs2_calc_extend_credits(inode->i_sb, di, 1713 clusters_to_alloc); 1714 1715 } 1716 1717 ocfs2_set_target_boundaries(osb, wc, pos, len, 1718 clusters_to_alloc + extents_to_split); 1719 1720 handle = ocfs2_start_trans(osb, credits); 1721 if (IS_ERR(handle)) { 1722 ret = PTR_ERR(handle); 1723 mlog_errno(ret); 1724 goto out; 1725 } 1726 1727 wc->w_handle = handle; 1728 1729 /* 1730 * We don't want this to fail in ocfs2_write_end(), so do it 1731 * here. 1732 */ 1733 ret = ocfs2_journal_access(handle, inode, wc->w_di_bh, 1734 OCFS2_JOURNAL_ACCESS_WRITE); 1735 if (ret) { 1736 mlog_errno(ret); 1737 goto out_commit; 1738 } 1739 1740 /* 1741 * Fill our page array first. That way we've grabbed enough so 1742 * that we can zero and flush if we error after adding the 1743 * extent. 1744 */ 1745 ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos, 1746 clusters_to_alloc + extents_to_split, 1747 mmap_page); 1748 if (ret) { 1749 mlog_errno(ret); 1750 goto out_commit; 1751 } 1752 1753 ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos, 1754 len); 1755 if (ret) { 1756 mlog_errno(ret); 1757 goto out_commit; 1758 } 1759 1760 if (data_ac) 1761 ocfs2_free_alloc_context(data_ac); 1762 if (meta_ac) 1763 ocfs2_free_alloc_context(meta_ac); 1764 1765 success: 1766 *pagep = wc->w_target_page; 1767 *fsdata = wc; 1768 return 0; 1769 out_commit: 1770 ocfs2_commit_trans(osb, handle); 1771 1772 out: 1773 ocfs2_free_write_ctxt(wc); 1774 1775 if (data_ac) 1776 ocfs2_free_alloc_context(data_ac); 1777 if (meta_ac) 1778 ocfs2_free_alloc_context(meta_ac); 1779 return ret; 1780 } 1781 1782 static int ocfs2_write_begin(struct file *file, struct address_space *mapping, 1783 loff_t pos, unsigned len, unsigned flags, 1784 struct page **pagep, void **fsdata) 1785 { 1786 int ret; 1787 struct buffer_head *di_bh = NULL; 1788 struct inode *inode = mapping->host; 1789 1790 ret = ocfs2_inode_lock(inode, &di_bh, 1); 1791 if (ret) { 1792 mlog_errno(ret); 1793 return ret; 1794 } 1795 1796 /* 1797 * Take alloc sem here to prevent concurrent lookups. That way 1798 * the mapping, zeroing and tree manipulation within 1799 * ocfs2_write() will be safe against ->readpage(). This 1800 * should also serve to lock out allocation from a shared 1801 * writeable region. 1802 */ 1803 down_write(&OCFS2_I(inode)->ip_alloc_sem); 1804 1805 ret = ocfs2_write_begin_nolock(mapping, pos, len, flags, pagep, 1806 fsdata, di_bh, NULL); 1807 if (ret) { 1808 mlog_errno(ret); 1809 goto out_fail; 1810 } 1811 1812 brelse(di_bh); 1813 1814 return 0; 1815 1816 out_fail: 1817 up_write(&OCFS2_I(inode)->ip_alloc_sem); 1818 1819 brelse(di_bh); 1820 ocfs2_inode_unlock(inode, 1); 1821 1822 return ret; 1823 } 1824 1825 static void ocfs2_write_end_inline(struct inode *inode, loff_t pos, 1826 unsigned len, unsigned *copied, 1827 struct ocfs2_dinode *di, 1828 struct ocfs2_write_ctxt *wc) 1829 { 1830 void *kaddr; 1831 1832 if (unlikely(*copied < len)) { 1833 if (!PageUptodate(wc->w_target_page)) { 1834 *copied = 0; 1835 return; 1836 } 1837 } 1838 1839 kaddr = kmap_atomic(wc->w_target_page, KM_USER0); 1840 memcpy(di->id2.i_data.id_data + pos, kaddr + pos, *copied); 1841 kunmap_atomic(kaddr, KM_USER0); 1842 1843 mlog(0, "Data written to inode at offset %llu. " 1844 "id_count = %u, copied = %u, i_dyn_features = 0x%x\n", 1845 (unsigned long long)pos, *copied, 1846 le16_to_cpu(di->id2.i_data.id_count), 1847 le16_to_cpu(di->i_dyn_features)); 1848 } 1849 1850 int ocfs2_write_end_nolock(struct address_space *mapping, 1851 loff_t pos, unsigned len, unsigned copied, 1852 struct page *page, void *fsdata) 1853 { 1854 int i; 1855 unsigned from, to, start = pos & (PAGE_CACHE_SIZE - 1); 1856 struct inode *inode = mapping->host; 1857 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1858 struct ocfs2_write_ctxt *wc = fsdata; 1859 struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data; 1860 handle_t *handle = wc->w_handle; 1861 struct page *tmppage; 1862 1863 if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) { 1864 ocfs2_write_end_inline(inode, pos, len, &copied, di, wc); 1865 goto out_write_size; 1866 } 1867 1868 if (unlikely(copied < len)) { 1869 if (!PageUptodate(wc->w_target_page)) 1870 copied = 0; 1871 1872 ocfs2_zero_new_buffers(wc->w_target_page, start+copied, 1873 start+len); 1874 } 1875 flush_dcache_page(wc->w_target_page); 1876 1877 for(i = 0; i < wc->w_num_pages; i++) { 1878 tmppage = wc->w_pages[i]; 1879 1880 if (tmppage == wc->w_target_page) { 1881 from = wc->w_target_from; 1882 to = wc->w_target_to; 1883 1884 BUG_ON(from > PAGE_CACHE_SIZE || 1885 to > PAGE_CACHE_SIZE || 1886 to < from); 1887 } else { 1888 /* 1889 * Pages adjacent to the target (if any) imply 1890 * a hole-filling write in which case we want 1891 * to flush their entire range. 1892 */ 1893 from = 0; 1894 to = PAGE_CACHE_SIZE; 1895 } 1896 1897 if (ocfs2_should_order_data(inode)) 1898 walk_page_buffers(wc->w_handle, page_buffers(tmppage), 1899 from, to, NULL, 1900 ocfs2_journal_dirty_data); 1901 1902 block_commit_write(tmppage, from, to); 1903 } 1904 1905 out_write_size: 1906 pos += copied; 1907 if (pos > inode->i_size) { 1908 i_size_write(inode, pos); 1909 mark_inode_dirty(inode); 1910 } 1911 inode->i_blocks = ocfs2_inode_sector_count(inode); 1912 di->i_size = cpu_to_le64((u64)i_size_read(inode)); 1913 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1914 di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec); 1915 di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec); 1916 ocfs2_journal_dirty(handle, wc->w_di_bh); 1917 1918 ocfs2_commit_trans(osb, handle); 1919 1920 ocfs2_run_deallocs(osb, &wc->w_dealloc); 1921 1922 ocfs2_free_write_ctxt(wc); 1923 1924 return copied; 1925 } 1926 1927 static int ocfs2_write_end(struct file *file, struct address_space *mapping, 1928 loff_t pos, unsigned len, unsigned copied, 1929 struct page *page, void *fsdata) 1930 { 1931 int ret; 1932 struct inode *inode = mapping->host; 1933 1934 ret = ocfs2_write_end_nolock(mapping, pos, len, copied, page, fsdata); 1935 1936 up_write(&OCFS2_I(inode)->ip_alloc_sem); 1937 ocfs2_inode_unlock(inode, 1); 1938 1939 return ret; 1940 } 1941 1942 const struct address_space_operations ocfs2_aops = { 1943 .readpage = ocfs2_readpage, 1944 .readpages = ocfs2_readpages, 1945 .writepage = ocfs2_writepage, 1946 .write_begin = ocfs2_write_begin, 1947 .write_end = ocfs2_write_end, 1948 .bmap = ocfs2_bmap, 1949 .sync_page = block_sync_page, 1950 .direct_IO = ocfs2_direct_IO, 1951 .invalidatepage = ocfs2_invalidatepage, 1952 .releasepage = ocfs2_releasepage, 1953 .migratepage = buffer_migrate_page, 1954 }; 1955