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 #include <linux/quotaops.h> 31 32 #define MLOG_MASK_PREFIX ML_FILE_IO 33 #include <cluster/masklog.h> 34 35 #include "ocfs2.h" 36 37 #include "alloc.h" 38 #include "aops.h" 39 #include "dlmglue.h" 40 #include "extent_map.h" 41 #include "file.h" 42 #include "inode.h" 43 #include "journal.h" 44 #include "suballoc.h" 45 #include "super.h" 46 #include "symlink.h" 47 #include "refcounttree.h" 48 49 #include "buffer_head_io.h" 50 51 static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock, 52 struct buffer_head *bh_result, int create) 53 { 54 int err = -EIO; 55 int status; 56 struct ocfs2_dinode *fe = NULL; 57 struct buffer_head *bh = NULL; 58 struct buffer_head *buffer_cache_bh = NULL; 59 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 60 void *kaddr; 61 62 mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode, 63 (unsigned long long)iblock, bh_result, create); 64 65 BUG_ON(ocfs2_inode_is_fast_symlink(inode)); 66 67 if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) { 68 mlog(ML_ERROR, "block offset > PATH_MAX: %llu", 69 (unsigned long long)iblock); 70 goto bail; 71 } 72 73 status = ocfs2_read_inode_block(inode, &bh); 74 if (status < 0) { 75 mlog_errno(status); 76 goto bail; 77 } 78 fe = (struct ocfs2_dinode *) bh->b_data; 79 80 if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb, 81 le32_to_cpu(fe->i_clusters))) { 82 mlog(ML_ERROR, "block offset is outside the allocated size: " 83 "%llu\n", (unsigned long long)iblock); 84 goto bail; 85 } 86 87 /* We don't use the page cache to create symlink data, so if 88 * need be, copy it over from the buffer cache. */ 89 if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) { 90 u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + 91 iblock; 92 buffer_cache_bh = sb_getblk(osb->sb, blkno); 93 if (!buffer_cache_bh) { 94 mlog(ML_ERROR, "couldn't getblock for symlink!\n"); 95 goto bail; 96 } 97 98 /* we haven't locked out transactions, so a commit 99 * could've happened. Since we've got a reference on 100 * the bh, even if it commits while we're doing the 101 * copy, the data is still good. */ 102 if (buffer_jbd(buffer_cache_bh) 103 && ocfs2_inode_is_new(inode)) { 104 kaddr = kmap_atomic(bh_result->b_page, KM_USER0); 105 if (!kaddr) { 106 mlog(ML_ERROR, "couldn't kmap!\n"); 107 goto bail; 108 } 109 memcpy(kaddr + (bh_result->b_size * iblock), 110 buffer_cache_bh->b_data, 111 bh_result->b_size); 112 kunmap_atomic(kaddr, KM_USER0); 113 set_buffer_uptodate(bh_result); 114 } 115 brelse(buffer_cache_bh); 116 } 117 118 map_bh(bh_result, inode->i_sb, 119 le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock); 120 121 err = 0; 122 123 bail: 124 brelse(bh); 125 126 mlog_exit(err); 127 return err; 128 } 129 130 int ocfs2_get_block(struct inode *inode, sector_t iblock, 131 struct buffer_head *bh_result, int create) 132 { 133 int err = 0; 134 unsigned int ext_flags; 135 u64 max_blocks = bh_result->b_size >> inode->i_blkbits; 136 u64 p_blkno, count, past_eof; 137 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 138 139 mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode, 140 (unsigned long long)iblock, bh_result, create); 141 142 if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE) 143 mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n", 144 inode, inode->i_ino); 145 146 if (S_ISLNK(inode->i_mode)) { 147 /* this always does I/O for some reason. */ 148 err = ocfs2_symlink_get_block(inode, iblock, bh_result, create); 149 goto bail; 150 } 151 152 err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, &count, 153 &ext_flags); 154 if (err) { 155 mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, " 156 "%llu, NULL)\n", err, inode, (unsigned long long)iblock, 157 (unsigned long long)p_blkno); 158 goto bail; 159 } 160 161 if (max_blocks < count) 162 count = max_blocks; 163 164 /* 165 * ocfs2 never allocates in this function - the only time we 166 * need to use BH_New is when we're extending i_size on a file 167 * system which doesn't support holes, in which case BH_New 168 * allows block_prepare_write() to zero. 169 * 170 * If we see this on a sparse file system, then a truncate has 171 * raced us and removed the cluster. In this case, we clear 172 * the buffers dirty and uptodate bits and let the buffer code 173 * ignore it as a hole. 174 */ 175 if (create && p_blkno == 0 && ocfs2_sparse_alloc(osb)) { 176 clear_buffer_dirty(bh_result); 177 clear_buffer_uptodate(bh_result); 178 goto bail; 179 } 180 181 /* Treat the unwritten extent as a hole for zeroing purposes. */ 182 if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN)) 183 map_bh(bh_result, inode->i_sb, p_blkno); 184 185 bh_result->b_size = count << inode->i_blkbits; 186 187 if (!ocfs2_sparse_alloc(osb)) { 188 if (p_blkno == 0) { 189 err = -EIO; 190 mlog(ML_ERROR, 191 "iblock = %llu p_blkno = %llu blkno=(%llu)\n", 192 (unsigned long long)iblock, 193 (unsigned long long)p_blkno, 194 (unsigned long long)OCFS2_I(inode)->ip_blkno); 195 mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters); 196 dump_stack(); 197 goto bail; 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_with_xattr(inode->i_sb, di)) { 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; 257 258 BUG_ON(!PageLocked(page)); 259 BUG_ON(!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)); 260 261 ret = ocfs2_read_inode_block(inode, &di_bh); 262 if (ret) { 263 mlog_errno(ret); 264 goto out; 265 } 266 267 ret = ocfs2_read_inline_data(inode, page, di_bh); 268 out: 269 unlock_page(page); 270 271 brelse(di_bh); 272 return ret; 273 } 274 275 static int ocfs2_readpage(struct file *file, struct page *page) 276 { 277 struct inode *inode = page->mapping->host; 278 struct ocfs2_inode_info *oi = OCFS2_I(inode); 279 loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT; 280 int ret, unlock = 1; 281 282 mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0)); 283 284 ret = ocfs2_inode_lock_with_page(inode, NULL, 0, page); 285 if (ret != 0) { 286 if (ret == AOP_TRUNCATED_PAGE) 287 unlock = 0; 288 mlog_errno(ret); 289 goto out; 290 } 291 292 if (down_read_trylock(&oi->ip_alloc_sem) == 0) { 293 ret = AOP_TRUNCATED_PAGE; 294 goto out_inode_unlock; 295 } 296 297 /* 298 * i_size might have just been updated as we grabed the meta lock. We 299 * might now be discovering a truncate that hit on another node. 300 * block_read_full_page->get_block freaks out if it is asked to read 301 * beyond the end of a file, so we check here. Callers 302 * (generic_file_read, vm_ops->fault) are clever enough to check i_size 303 * and notice that the page they just read isn't needed. 304 * 305 * XXX sys_readahead() seems to get that wrong? 306 */ 307 if (start >= i_size_read(inode)) { 308 zero_user(page, 0, PAGE_SIZE); 309 SetPageUptodate(page); 310 ret = 0; 311 goto out_alloc; 312 } 313 314 if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) 315 ret = ocfs2_readpage_inline(inode, page); 316 else 317 ret = block_read_full_page(page, ocfs2_get_block); 318 unlock = 0; 319 320 out_alloc: 321 up_read(&OCFS2_I(inode)->ip_alloc_sem); 322 out_inode_unlock: 323 ocfs2_inode_unlock(inode, 0); 324 out: 325 if (unlock) 326 unlock_page(page); 327 mlog_exit(ret); 328 return ret; 329 } 330 331 /* 332 * This is used only for read-ahead. Failures or difficult to handle 333 * situations are safe to ignore. 334 * 335 * Right now, we don't bother with BH_Boundary - in-inode extent lists 336 * are quite large (243 extents on 4k blocks), so most inodes don't 337 * grow out to a tree. If need be, detecting boundary extents could 338 * trivially be added in a future version of ocfs2_get_block(). 339 */ 340 static int ocfs2_readpages(struct file *filp, struct address_space *mapping, 341 struct list_head *pages, unsigned nr_pages) 342 { 343 int ret, err = -EIO; 344 struct inode *inode = mapping->host; 345 struct ocfs2_inode_info *oi = OCFS2_I(inode); 346 loff_t start; 347 struct page *last; 348 349 /* 350 * Use the nonblocking flag for the dlm code to avoid page 351 * lock inversion, but don't bother with retrying. 352 */ 353 ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK); 354 if (ret) 355 return err; 356 357 if (down_read_trylock(&oi->ip_alloc_sem) == 0) { 358 ocfs2_inode_unlock(inode, 0); 359 return err; 360 } 361 362 /* 363 * Don't bother with inline-data. There isn't anything 364 * to read-ahead in that case anyway... 365 */ 366 if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) 367 goto out_unlock; 368 369 /* 370 * Check whether a remote node truncated this file - we just 371 * drop out in that case as it's not worth handling here. 372 */ 373 last = list_entry(pages->prev, struct page, lru); 374 start = (loff_t)last->index << PAGE_CACHE_SHIFT; 375 if (start >= i_size_read(inode)) 376 goto out_unlock; 377 378 err = mpage_readpages(mapping, pages, nr_pages, ocfs2_get_block); 379 380 out_unlock: 381 up_read(&oi->ip_alloc_sem); 382 ocfs2_inode_unlock(inode, 0); 383 384 return err; 385 } 386 387 /* Note: Because we don't support holes, our allocation has 388 * already happened (allocation writes zeros to the file data) 389 * so we don't have to worry about ordered writes in 390 * ocfs2_writepage. 391 * 392 * ->writepage is called during the process of invalidating the page cache 393 * during blocked lock processing. It can't block on any cluster locks 394 * to during block mapping. It's relying on the fact that the block 395 * mapping can't have disappeared under the dirty pages that it is 396 * being asked to write back. 397 */ 398 static int ocfs2_writepage(struct page *page, struct writeback_control *wbc) 399 { 400 int ret; 401 402 mlog_entry("(0x%p)\n", page); 403 404 ret = block_write_full_page(page, ocfs2_get_block, wbc); 405 406 mlog_exit(ret); 407 408 return ret; 409 } 410 411 /* 412 * This is called from ocfs2_write_zero_page() which has handled it's 413 * own cluster locking and has ensured allocation exists for those 414 * blocks to be written. 415 */ 416 int ocfs2_prepare_write_nolock(struct inode *inode, struct page *page, 417 unsigned from, unsigned to) 418 { 419 int ret; 420 421 ret = block_prepare_write(page, from, to, ocfs2_get_block); 422 423 return ret; 424 } 425 426 /* Taken from ext3. We don't necessarily need the full blown 427 * functionality yet, but IMHO it's better to cut and paste the whole 428 * thing so we can avoid introducing our own bugs (and easily pick up 429 * their fixes when they happen) --Mark */ 430 int walk_page_buffers( handle_t *handle, 431 struct buffer_head *head, 432 unsigned from, 433 unsigned to, 434 int *partial, 435 int (*fn)( handle_t *handle, 436 struct buffer_head *bh)) 437 { 438 struct buffer_head *bh; 439 unsigned block_start, block_end; 440 unsigned blocksize = head->b_size; 441 int err, ret = 0; 442 struct buffer_head *next; 443 444 for ( bh = head, block_start = 0; 445 ret == 0 && (bh != head || !block_start); 446 block_start = block_end, bh = next) 447 { 448 next = bh->b_this_page; 449 block_end = block_start + blocksize; 450 if (block_end <= from || block_start >= to) { 451 if (partial && !buffer_uptodate(bh)) 452 *partial = 1; 453 continue; 454 } 455 err = (*fn)(handle, bh); 456 if (!ret) 457 ret = err; 458 } 459 return ret; 460 } 461 462 handle_t *ocfs2_start_walk_page_trans(struct inode *inode, 463 struct page *page, 464 unsigned from, 465 unsigned to) 466 { 467 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 468 handle_t *handle; 469 int ret = 0; 470 471 handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS); 472 if (IS_ERR(handle)) { 473 ret = -ENOMEM; 474 mlog_errno(ret); 475 goto out; 476 } 477 478 if (ocfs2_should_order_data(inode)) { 479 ret = ocfs2_jbd2_file_inode(handle, inode); 480 if (ret < 0) 481 mlog_errno(ret); 482 } 483 out: 484 if (ret) { 485 if (!IS_ERR(handle)) 486 ocfs2_commit_trans(osb, handle); 487 handle = ERR_PTR(ret); 488 } 489 return handle; 490 } 491 492 static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block) 493 { 494 sector_t status; 495 u64 p_blkno = 0; 496 int err = 0; 497 struct inode *inode = mapping->host; 498 499 mlog_entry("(block = %llu)\n", (unsigned long long)block); 500 501 /* We don't need to lock journal system files, since they aren't 502 * accessed concurrently from multiple nodes. 503 */ 504 if (!INODE_JOURNAL(inode)) { 505 err = ocfs2_inode_lock(inode, NULL, 0); 506 if (err) { 507 if (err != -ENOENT) 508 mlog_errno(err); 509 goto bail; 510 } 511 down_read(&OCFS2_I(inode)->ip_alloc_sem); 512 } 513 514 if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)) 515 err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL, 516 NULL); 517 518 if (!INODE_JOURNAL(inode)) { 519 up_read(&OCFS2_I(inode)->ip_alloc_sem); 520 ocfs2_inode_unlock(inode, 0); 521 } 522 523 if (err) { 524 mlog(ML_ERROR, "get_blocks() failed, block = %llu\n", 525 (unsigned long long)block); 526 mlog_errno(err); 527 goto bail; 528 } 529 530 bail: 531 status = err ? 0 : p_blkno; 532 533 mlog_exit((int)status); 534 535 return status; 536 } 537 538 /* 539 * TODO: Make this into a generic get_blocks function. 540 * 541 * From do_direct_io in direct-io.c: 542 * "So what we do is to permit the ->get_blocks function to populate 543 * bh.b_size with the size of IO which is permitted at this offset and 544 * this i_blkbits." 545 * 546 * This function is called directly from get_more_blocks in direct-io.c. 547 * 548 * called like this: dio->get_blocks(dio->inode, fs_startblk, 549 * fs_count, map_bh, dio->rw == WRITE); 550 * 551 * Note that we never bother to allocate blocks here, and thus ignore the 552 * create argument. 553 */ 554 static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock, 555 struct buffer_head *bh_result, int create) 556 { 557 int ret; 558 u64 p_blkno, inode_blocks, contig_blocks; 559 unsigned int ext_flags; 560 unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits; 561 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 562 563 /* This function won't even be called if the request isn't all 564 * nicely aligned and of the right size, so there's no need 565 * for us to check any of that. */ 566 567 inode_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode)); 568 569 /* This figures out the size of the next contiguous block, and 570 * our logical offset */ 571 ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, 572 &contig_blocks, &ext_flags); 573 if (ret) { 574 mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n", 575 (unsigned long long)iblock); 576 ret = -EIO; 577 goto bail; 578 } 579 580 /* We should already CoW the refcounted extent. */ 581 BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED); 582 /* 583 * get_more_blocks() expects us to describe a hole by clearing 584 * the mapped bit on bh_result(). 585 * 586 * Consider an unwritten extent as a hole. 587 */ 588 if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN)) 589 map_bh(bh_result, inode->i_sb, p_blkno); 590 else 591 clear_buffer_mapped(bh_result); 592 593 /* make sure we don't map more than max_blocks blocks here as 594 that's all the kernel will handle at this point. */ 595 if (max_blocks < contig_blocks) 596 contig_blocks = max_blocks; 597 bh_result->b_size = contig_blocks << blocksize_bits; 598 bail: 599 return ret; 600 } 601 602 /* 603 * ocfs2_dio_end_io is called by the dio core when a dio is finished. We're 604 * particularly interested in the aio/dio case. Like the core uses 605 * i_alloc_sem, we use the rw_lock DLM lock to protect io on one node from 606 * truncation on another. 607 */ 608 static void ocfs2_dio_end_io(struct kiocb *iocb, 609 loff_t offset, 610 ssize_t bytes, 611 void *private) 612 { 613 struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode; 614 int level; 615 616 /* this io's submitter should not have unlocked this before we could */ 617 BUG_ON(!ocfs2_iocb_is_rw_locked(iocb)); 618 619 ocfs2_iocb_clear_rw_locked(iocb); 620 621 level = ocfs2_iocb_rw_locked_level(iocb); 622 if (!level) 623 up_read(&inode->i_alloc_sem); 624 ocfs2_rw_unlock(inode, level); 625 } 626 627 /* 628 * ocfs2_invalidatepage() and ocfs2_releasepage() are shamelessly stolen 629 * from ext3. PageChecked() bits have been removed as OCFS2 does not 630 * do journalled data. 631 */ 632 static void ocfs2_invalidatepage(struct page *page, unsigned long offset) 633 { 634 journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal; 635 636 jbd2_journal_invalidatepage(journal, page, offset); 637 } 638 639 static int ocfs2_releasepage(struct page *page, gfp_t wait) 640 { 641 journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal; 642 643 if (!page_has_buffers(page)) 644 return 0; 645 return jbd2_journal_try_to_free_buffers(journal, page, wait); 646 } 647 648 static ssize_t ocfs2_direct_IO(int rw, 649 struct kiocb *iocb, 650 const struct iovec *iov, 651 loff_t offset, 652 unsigned long nr_segs) 653 { 654 struct file *file = iocb->ki_filp; 655 struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host; 656 int ret; 657 658 mlog_entry_void(); 659 660 /* 661 * Fallback to buffered I/O if we see an inode without 662 * extents. 663 */ 664 if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) 665 return 0; 666 667 /* Fallback to buffered I/O if we are appending. */ 668 if (i_size_read(inode) <= offset) 669 return 0; 670 671 ret = blockdev_direct_IO_no_locking(rw, iocb, inode, 672 inode->i_sb->s_bdev, iov, offset, 673 nr_segs, 674 ocfs2_direct_IO_get_blocks, 675 ocfs2_dio_end_io); 676 677 mlog_exit(ret); 678 return ret; 679 } 680 681 static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb, 682 u32 cpos, 683 unsigned int *start, 684 unsigned int *end) 685 { 686 unsigned int cluster_start = 0, cluster_end = PAGE_CACHE_SIZE; 687 688 if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) { 689 unsigned int cpp; 690 691 cpp = 1 << (PAGE_CACHE_SHIFT - osb->s_clustersize_bits); 692 693 cluster_start = cpos % cpp; 694 cluster_start = cluster_start << osb->s_clustersize_bits; 695 696 cluster_end = cluster_start + osb->s_clustersize; 697 } 698 699 BUG_ON(cluster_start > PAGE_SIZE); 700 BUG_ON(cluster_end > PAGE_SIZE); 701 702 if (start) 703 *start = cluster_start; 704 if (end) 705 *end = cluster_end; 706 } 707 708 /* 709 * 'from' and 'to' are the region in the page to avoid zeroing. 710 * 711 * If pagesize > clustersize, this function will avoid zeroing outside 712 * of the cluster boundary. 713 * 714 * from == to == 0 is code for "zero the entire cluster region" 715 */ 716 static void ocfs2_clear_page_regions(struct page *page, 717 struct ocfs2_super *osb, u32 cpos, 718 unsigned from, unsigned to) 719 { 720 void *kaddr; 721 unsigned int cluster_start, cluster_end; 722 723 ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end); 724 725 kaddr = kmap_atomic(page, KM_USER0); 726 727 if (from || to) { 728 if (from > cluster_start) 729 memset(kaddr + cluster_start, 0, from - cluster_start); 730 if (to < cluster_end) 731 memset(kaddr + to, 0, cluster_end - to); 732 } else { 733 memset(kaddr + cluster_start, 0, cluster_end - cluster_start); 734 } 735 736 kunmap_atomic(kaddr, KM_USER0); 737 } 738 739 /* 740 * Nonsparse file systems fully allocate before we get to the write 741 * code. This prevents ocfs2_write() from tagging the write as an 742 * allocating one, which means ocfs2_map_page_blocks() might try to 743 * read-in the blocks at the tail of our file. Avoid reading them by 744 * testing i_size against each block offset. 745 */ 746 static int ocfs2_should_read_blk(struct inode *inode, struct page *page, 747 unsigned int block_start) 748 { 749 u64 offset = page_offset(page) + block_start; 750 751 if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) 752 return 1; 753 754 if (i_size_read(inode) > offset) 755 return 1; 756 757 return 0; 758 } 759 760 /* 761 * Some of this taken from block_prepare_write(). We already have our 762 * mapping by now though, and the entire write will be allocating or 763 * it won't, so not much need to use BH_New. 764 * 765 * This will also skip zeroing, which is handled externally. 766 */ 767 int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno, 768 struct inode *inode, unsigned int from, 769 unsigned int to, int new) 770 { 771 int ret = 0; 772 struct buffer_head *head, *bh, *wait[2], **wait_bh = wait; 773 unsigned int block_end, block_start; 774 unsigned int bsize = 1 << inode->i_blkbits; 775 776 if (!page_has_buffers(page)) 777 create_empty_buffers(page, bsize, 0); 778 779 head = page_buffers(page); 780 for (bh = head, block_start = 0; bh != head || !block_start; 781 bh = bh->b_this_page, block_start += bsize) { 782 block_end = block_start + bsize; 783 784 clear_buffer_new(bh); 785 786 /* 787 * Ignore blocks outside of our i/o range - 788 * they may belong to unallocated clusters. 789 */ 790 if (block_start >= to || block_end <= from) { 791 if (PageUptodate(page)) 792 set_buffer_uptodate(bh); 793 continue; 794 } 795 796 /* 797 * For an allocating write with cluster size >= page 798 * size, we always write the entire page. 799 */ 800 if (new) 801 set_buffer_new(bh); 802 803 if (!buffer_mapped(bh)) { 804 map_bh(bh, inode->i_sb, *p_blkno); 805 unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); 806 } 807 808 if (PageUptodate(page)) { 809 if (!buffer_uptodate(bh)) 810 set_buffer_uptodate(bh); 811 } else if (!buffer_uptodate(bh) && !buffer_delay(bh) && 812 !buffer_new(bh) && 813 ocfs2_should_read_blk(inode, page, block_start) && 814 (block_start < from || block_end > to)) { 815 ll_rw_block(READ, 1, &bh); 816 *wait_bh++=bh; 817 } 818 819 *p_blkno = *p_blkno + 1; 820 } 821 822 /* 823 * If we issued read requests - let them complete. 824 */ 825 while(wait_bh > wait) { 826 wait_on_buffer(*--wait_bh); 827 if (!buffer_uptodate(*wait_bh)) 828 ret = -EIO; 829 } 830 831 if (ret == 0 || !new) 832 return ret; 833 834 /* 835 * If we get -EIO above, zero out any newly allocated blocks 836 * to avoid exposing stale data. 837 */ 838 bh = head; 839 block_start = 0; 840 do { 841 block_end = block_start + bsize; 842 if (block_end <= from) 843 goto next_bh; 844 if (block_start >= to) 845 break; 846 847 zero_user(page, block_start, bh->b_size); 848 set_buffer_uptodate(bh); 849 mark_buffer_dirty(bh); 850 851 next_bh: 852 block_start = block_end; 853 bh = bh->b_this_page; 854 } while (bh != head); 855 856 return ret; 857 } 858 859 #if (PAGE_CACHE_SIZE >= OCFS2_MAX_CLUSTERSIZE) 860 #define OCFS2_MAX_CTXT_PAGES 1 861 #else 862 #define OCFS2_MAX_CTXT_PAGES (OCFS2_MAX_CLUSTERSIZE / PAGE_CACHE_SIZE) 863 #endif 864 865 #define OCFS2_MAX_CLUSTERS_PER_PAGE (PAGE_CACHE_SIZE / OCFS2_MIN_CLUSTERSIZE) 866 867 /* 868 * Describe the state of a single cluster to be written to. 869 */ 870 struct ocfs2_write_cluster_desc { 871 u32 c_cpos; 872 u32 c_phys; 873 /* 874 * Give this a unique field because c_phys eventually gets 875 * filled. 876 */ 877 unsigned c_new; 878 unsigned c_unwritten; 879 unsigned c_needs_zero; 880 }; 881 882 struct ocfs2_write_ctxt { 883 /* Logical cluster position / len of write */ 884 u32 w_cpos; 885 u32 w_clen; 886 887 /* First cluster allocated in a nonsparse extend */ 888 u32 w_first_new_cpos; 889 890 struct ocfs2_write_cluster_desc w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE]; 891 892 /* 893 * This is true if page_size > cluster_size. 894 * 895 * It triggers a set of special cases during write which might 896 * have to deal with allocating writes to partial pages. 897 */ 898 unsigned int w_large_pages; 899 900 /* 901 * Pages involved in this write. 902 * 903 * w_target_page is the page being written to by the user. 904 * 905 * w_pages is an array of pages which always contains 906 * w_target_page, and in the case of an allocating write with 907 * page_size < cluster size, it will contain zero'd and mapped 908 * pages adjacent to w_target_page which need to be written 909 * out in so that future reads from that region will get 910 * zero's. 911 */ 912 struct page *w_pages[OCFS2_MAX_CTXT_PAGES]; 913 unsigned int w_num_pages; 914 struct page *w_target_page; 915 916 /* 917 * ocfs2_write_end() uses this to know what the real range to 918 * write in the target should be. 919 */ 920 unsigned int w_target_from; 921 unsigned int w_target_to; 922 923 /* 924 * We could use journal_current_handle() but this is cleaner, 925 * IMHO -Mark 926 */ 927 handle_t *w_handle; 928 929 struct buffer_head *w_di_bh; 930 931 struct ocfs2_cached_dealloc_ctxt w_dealloc; 932 }; 933 934 void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages) 935 { 936 int i; 937 938 for(i = 0; i < num_pages; i++) { 939 if (pages[i]) { 940 unlock_page(pages[i]); 941 mark_page_accessed(pages[i]); 942 page_cache_release(pages[i]); 943 } 944 } 945 } 946 947 static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc) 948 { 949 ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages); 950 951 brelse(wc->w_di_bh); 952 kfree(wc); 953 } 954 955 static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp, 956 struct ocfs2_super *osb, loff_t pos, 957 unsigned len, struct buffer_head *di_bh) 958 { 959 u32 cend; 960 struct ocfs2_write_ctxt *wc; 961 962 wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS); 963 if (!wc) 964 return -ENOMEM; 965 966 wc->w_cpos = pos >> osb->s_clustersize_bits; 967 wc->w_first_new_cpos = UINT_MAX; 968 cend = (pos + len - 1) >> osb->s_clustersize_bits; 969 wc->w_clen = cend - wc->w_cpos + 1; 970 get_bh(di_bh); 971 wc->w_di_bh = di_bh; 972 973 if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) 974 wc->w_large_pages = 1; 975 else 976 wc->w_large_pages = 0; 977 978 ocfs2_init_dealloc_ctxt(&wc->w_dealloc); 979 980 *wcp = wc; 981 982 return 0; 983 } 984 985 /* 986 * If a page has any new buffers, zero them out here, and mark them uptodate 987 * and dirty so they'll be written out (in order to prevent uninitialised 988 * block data from leaking). And clear the new bit. 989 */ 990 static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to) 991 { 992 unsigned int block_start, block_end; 993 struct buffer_head *head, *bh; 994 995 BUG_ON(!PageLocked(page)); 996 if (!page_has_buffers(page)) 997 return; 998 999 bh = head = page_buffers(page); 1000 block_start = 0; 1001 do { 1002 block_end = block_start + bh->b_size; 1003 1004 if (buffer_new(bh)) { 1005 if (block_end > from && block_start < to) { 1006 if (!PageUptodate(page)) { 1007 unsigned start, end; 1008 1009 start = max(from, block_start); 1010 end = min(to, block_end); 1011 1012 zero_user_segment(page, start, end); 1013 set_buffer_uptodate(bh); 1014 } 1015 1016 clear_buffer_new(bh); 1017 mark_buffer_dirty(bh); 1018 } 1019 } 1020 1021 block_start = block_end; 1022 bh = bh->b_this_page; 1023 } while (bh != head); 1024 } 1025 1026 /* 1027 * Only called when we have a failure during allocating write to write 1028 * zero's to the newly allocated region. 1029 */ 1030 static void ocfs2_write_failure(struct inode *inode, 1031 struct ocfs2_write_ctxt *wc, 1032 loff_t user_pos, unsigned user_len) 1033 { 1034 int i; 1035 unsigned from = user_pos & (PAGE_CACHE_SIZE - 1), 1036 to = user_pos + user_len; 1037 struct page *tmppage; 1038 1039 ocfs2_zero_new_buffers(wc->w_target_page, from, to); 1040 1041 for(i = 0; i < wc->w_num_pages; i++) { 1042 tmppage = wc->w_pages[i]; 1043 1044 if (page_has_buffers(tmppage)) { 1045 if (ocfs2_should_order_data(inode)) 1046 ocfs2_jbd2_file_inode(wc->w_handle, inode); 1047 1048 block_commit_write(tmppage, from, to); 1049 } 1050 } 1051 } 1052 1053 static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno, 1054 struct ocfs2_write_ctxt *wc, 1055 struct page *page, u32 cpos, 1056 loff_t user_pos, unsigned user_len, 1057 int new) 1058 { 1059 int ret; 1060 unsigned int map_from = 0, map_to = 0; 1061 unsigned int cluster_start, cluster_end; 1062 unsigned int user_data_from = 0, user_data_to = 0; 1063 1064 ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos, 1065 &cluster_start, &cluster_end); 1066 1067 if (page == wc->w_target_page) { 1068 map_from = user_pos & (PAGE_CACHE_SIZE - 1); 1069 map_to = map_from + user_len; 1070 1071 if (new) 1072 ret = ocfs2_map_page_blocks(page, p_blkno, inode, 1073 cluster_start, cluster_end, 1074 new); 1075 else 1076 ret = ocfs2_map_page_blocks(page, p_blkno, inode, 1077 map_from, map_to, new); 1078 if (ret) { 1079 mlog_errno(ret); 1080 goto out; 1081 } 1082 1083 user_data_from = map_from; 1084 user_data_to = map_to; 1085 if (new) { 1086 map_from = cluster_start; 1087 map_to = cluster_end; 1088 } 1089 } else { 1090 /* 1091 * If we haven't allocated the new page yet, we 1092 * shouldn't be writing it out without copying user 1093 * data. This is likely a math error from the caller. 1094 */ 1095 BUG_ON(!new); 1096 1097 map_from = cluster_start; 1098 map_to = cluster_end; 1099 1100 ret = ocfs2_map_page_blocks(page, p_blkno, inode, 1101 cluster_start, cluster_end, new); 1102 if (ret) { 1103 mlog_errno(ret); 1104 goto out; 1105 } 1106 } 1107 1108 /* 1109 * Parts of newly allocated pages need to be zero'd. 1110 * 1111 * Above, we have also rewritten 'to' and 'from' - as far as 1112 * the rest of the function is concerned, the entire cluster 1113 * range inside of a page needs to be written. 1114 * 1115 * We can skip this if the page is up to date - it's already 1116 * been zero'd from being read in as a hole. 1117 */ 1118 if (new && !PageUptodate(page)) 1119 ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb), 1120 cpos, user_data_from, user_data_to); 1121 1122 flush_dcache_page(page); 1123 1124 out: 1125 return ret; 1126 } 1127 1128 /* 1129 * This function will only grab one clusters worth of pages. 1130 */ 1131 static int ocfs2_grab_pages_for_write(struct address_space *mapping, 1132 struct ocfs2_write_ctxt *wc, 1133 u32 cpos, loff_t user_pos, int new, 1134 struct page *mmap_page) 1135 { 1136 int ret = 0, i; 1137 unsigned long start, target_index, index; 1138 struct inode *inode = mapping->host; 1139 1140 target_index = user_pos >> PAGE_CACHE_SHIFT; 1141 1142 /* 1143 * Figure out how many pages we'll be manipulating here. For 1144 * non allocating write, we just change the one 1145 * page. Otherwise, we'll need a whole clusters worth. 1146 */ 1147 if (new) { 1148 wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb); 1149 start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos); 1150 } else { 1151 wc->w_num_pages = 1; 1152 start = target_index; 1153 } 1154 1155 for(i = 0; i < wc->w_num_pages; i++) { 1156 index = start + i; 1157 1158 if (index == target_index && mmap_page) { 1159 /* 1160 * ocfs2_pagemkwrite() is a little different 1161 * and wants us to directly use the page 1162 * passed in. 1163 */ 1164 lock_page(mmap_page); 1165 1166 if (mmap_page->mapping != mapping) { 1167 unlock_page(mmap_page); 1168 /* 1169 * Sanity check - the locking in 1170 * ocfs2_pagemkwrite() should ensure 1171 * that this code doesn't trigger. 1172 */ 1173 ret = -EINVAL; 1174 mlog_errno(ret); 1175 goto out; 1176 } 1177 1178 page_cache_get(mmap_page); 1179 wc->w_pages[i] = mmap_page; 1180 } else { 1181 wc->w_pages[i] = find_or_create_page(mapping, index, 1182 GFP_NOFS); 1183 if (!wc->w_pages[i]) { 1184 ret = -ENOMEM; 1185 mlog_errno(ret); 1186 goto out; 1187 } 1188 } 1189 1190 if (index == target_index) 1191 wc->w_target_page = wc->w_pages[i]; 1192 } 1193 out: 1194 return ret; 1195 } 1196 1197 /* 1198 * Prepare a single cluster for write one cluster into the file. 1199 */ 1200 static int ocfs2_write_cluster(struct address_space *mapping, 1201 u32 phys, unsigned int unwritten, 1202 unsigned int should_zero, 1203 struct ocfs2_alloc_context *data_ac, 1204 struct ocfs2_alloc_context *meta_ac, 1205 struct ocfs2_write_ctxt *wc, u32 cpos, 1206 loff_t user_pos, unsigned user_len) 1207 { 1208 int ret, i, new; 1209 u64 v_blkno, p_blkno; 1210 struct inode *inode = mapping->host; 1211 struct ocfs2_extent_tree et; 1212 1213 new = phys == 0 ? 1 : 0; 1214 if (new) { 1215 u32 tmp_pos; 1216 1217 /* 1218 * This is safe to call with the page locks - it won't take 1219 * any additional semaphores or cluster locks. 1220 */ 1221 tmp_pos = cpos; 1222 ret = ocfs2_add_inode_data(OCFS2_SB(inode->i_sb), inode, 1223 &tmp_pos, 1, 0, wc->w_di_bh, 1224 wc->w_handle, data_ac, 1225 meta_ac, NULL); 1226 /* 1227 * This shouldn't happen because we must have already 1228 * calculated the correct meta data allocation required. The 1229 * internal tree allocation code should know how to increase 1230 * transaction credits itself. 1231 * 1232 * If need be, we could handle -EAGAIN for a 1233 * RESTART_TRANS here. 1234 */ 1235 mlog_bug_on_msg(ret == -EAGAIN, 1236 "Inode %llu: EAGAIN return during allocation.\n", 1237 (unsigned long long)OCFS2_I(inode)->ip_blkno); 1238 if (ret < 0) { 1239 mlog_errno(ret); 1240 goto out; 1241 } 1242 } else if (unwritten) { 1243 ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), 1244 wc->w_di_bh); 1245 ret = ocfs2_mark_extent_written(inode, &et, 1246 wc->w_handle, cpos, 1, phys, 1247 meta_ac, &wc->w_dealloc); 1248 if (ret < 0) { 1249 mlog_errno(ret); 1250 goto out; 1251 } 1252 } 1253 1254 if (should_zero) 1255 v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, cpos); 1256 else 1257 v_blkno = user_pos >> inode->i_sb->s_blocksize_bits; 1258 1259 /* 1260 * The only reason this should fail is due to an inability to 1261 * find the extent added. 1262 */ 1263 ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL, 1264 NULL); 1265 if (ret < 0) { 1266 ocfs2_error(inode->i_sb, "Corrupting extend for inode %llu, " 1267 "at logical block %llu", 1268 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1269 (unsigned long long)v_blkno); 1270 goto out; 1271 } 1272 1273 BUG_ON(p_blkno == 0); 1274 1275 for(i = 0; i < wc->w_num_pages; i++) { 1276 int tmpret; 1277 1278 tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc, 1279 wc->w_pages[i], cpos, 1280 user_pos, user_len, 1281 should_zero); 1282 if (tmpret) { 1283 mlog_errno(tmpret); 1284 if (ret == 0) 1285 ret = tmpret; 1286 } 1287 } 1288 1289 /* 1290 * We only have cleanup to do in case of allocating write. 1291 */ 1292 if (ret && new) 1293 ocfs2_write_failure(inode, wc, user_pos, user_len); 1294 1295 out: 1296 1297 return ret; 1298 } 1299 1300 static int ocfs2_write_cluster_by_desc(struct address_space *mapping, 1301 struct ocfs2_alloc_context *data_ac, 1302 struct ocfs2_alloc_context *meta_ac, 1303 struct ocfs2_write_ctxt *wc, 1304 loff_t pos, unsigned len) 1305 { 1306 int ret, i; 1307 loff_t cluster_off; 1308 unsigned int local_len = len; 1309 struct ocfs2_write_cluster_desc *desc; 1310 struct ocfs2_super *osb = OCFS2_SB(mapping->host->i_sb); 1311 1312 for (i = 0; i < wc->w_clen; i++) { 1313 desc = &wc->w_desc[i]; 1314 1315 /* 1316 * We have to make sure that the total write passed in 1317 * doesn't extend past a single cluster. 1318 */ 1319 local_len = len; 1320 cluster_off = pos & (osb->s_clustersize - 1); 1321 if ((cluster_off + local_len) > osb->s_clustersize) 1322 local_len = osb->s_clustersize - cluster_off; 1323 1324 ret = ocfs2_write_cluster(mapping, desc->c_phys, 1325 desc->c_unwritten, 1326 desc->c_needs_zero, 1327 data_ac, meta_ac, 1328 wc, desc->c_cpos, pos, local_len); 1329 if (ret) { 1330 mlog_errno(ret); 1331 goto out; 1332 } 1333 1334 len -= local_len; 1335 pos += local_len; 1336 } 1337 1338 ret = 0; 1339 out: 1340 return ret; 1341 } 1342 1343 /* 1344 * ocfs2_write_end() wants to know which parts of the target page it 1345 * should complete the write on. It's easiest to compute them ahead of 1346 * time when a more complete view of the write is available. 1347 */ 1348 static void ocfs2_set_target_boundaries(struct ocfs2_super *osb, 1349 struct ocfs2_write_ctxt *wc, 1350 loff_t pos, unsigned len, int alloc) 1351 { 1352 struct ocfs2_write_cluster_desc *desc; 1353 1354 wc->w_target_from = pos & (PAGE_CACHE_SIZE - 1); 1355 wc->w_target_to = wc->w_target_from + len; 1356 1357 if (alloc == 0) 1358 return; 1359 1360 /* 1361 * Allocating write - we may have different boundaries based 1362 * on page size and cluster size. 1363 * 1364 * NOTE: We can no longer compute one value from the other as 1365 * the actual write length and user provided length may be 1366 * different. 1367 */ 1368 1369 if (wc->w_large_pages) { 1370 /* 1371 * We only care about the 1st and last cluster within 1372 * our range and whether they should be zero'd or not. Either 1373 * value may be extended out to the start/end of a 1374 * newly allocated cluster. 1375 */ 1376 desc = &wc->w_desc[0]; 1377 if (desc->c_needs_zero) 1378 ocfs2_figure_cluster_boundaries(osb, 1379 desc->c_cpos, 1380 &wc->w_target_from, 1381 NULL); 1382 1383 desc = &wc->w_desc[wc->w_clen - 1]; 1384 if (desc->c_needs_zero) 1385 ocfs2_figure_cluster_boundaries(osb, 1386 desc->c_cpos, 1387 NULL, 1388 &wc->w_target_to); 1389 } else { 1390 wc->w_target_from = 0; 1391 wc->w_target_to = PAGE_CACHE_SIZE; 1392 } 1393 } 1394 1395 /* 1396 * Populate each single-cluster write descriptor in the write context 1397 * with information about the i/o to be done. 1398 * 1399 * Returns the number of clusters that will have to be allocated, as 1400 * well as a worst case estimate of the number of extent records that 1401 * would have to be created during a write to an unwritten region. 1402 */ 1403 static int ocfs2_populate_write_desc(struct inode *inode, 1404 struct ocfs2_write_ctxt *wc, 1405 unsigned int *clusters_to_alloc, 1406 unsigned int *extents_to_split) 1407 { 1408 int ret; 1409 struct ocfs2_write_cluster_desc *desc; 1410 unsigned int num_clusters = 0; 1411 unsigned int ext_flags = 0; 1412 u32 phys = 0; 1413 int i; 1414 1415 *clusters_to_alloc = 0; 1416 *extents_to_split = 0; 1417 1418 for (i = 0; i < wc->w_clen; i++) { 1419 desc = &wc->w_desc[i]; 1420 desc->c_cpos = wc->w_cpos + i; 1421 1422 if (num_clusters == 0) { 1423 /* 1424 * Need to look up the next extent record. 1425 */ 1426 ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys, 1427 &num_clusters, &ext_flags); 1428 if (ret) { 1429 mlog_errno(ret); 1430 goto out; 1431 } 1432 1433 /* We should already CoW the refcountd extent. */ 1434 BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED); 1435 1436 /* 1437 * Assume worst case - that we're writing in 1438 * the middle of the extent. 1439 * 1440 * We can assume that the write proceeds from 1441 * left to right, in which case the extent 1442 * insert code is smart enough to coalesce the 1443 * next splits into the previous records created. 1444 */ 1445 if (ext_flags & OCFS2_EXT_UNWRITTEN) 1446 *extents_to_split = *extents_to_split + 2; 1447 } else if (phys) { 1448 /* 1449 * Only increment phys if it doesn't describe 1450 * a hole. 1451 */ 1452 phys++; 1453 } 1454 1455 /* 1456 * If w_first_new_cpos is < UINT_MAX, we have a non-sparse 1457 * file that got extended. w_first_new_cpos tells us 1458 * where the newly allocated clusters are so we can 1459 * zero them. 1460 */ 1461 if (desc->c_cpos >= wc->w_first_new_cpos) { 1462 BUG_ON(phys == 0); 1463 desc->c_needs_zero = 1; 1464 } 1465 1466 desc->c_phys = phys; 1467 if (phys == 0) { 1468 desc->c_new = 1; 1469 desc->c_needs_zero = 1; 1470 *clusters_to_alloc = *clusters_to_alloc + 1; 1471 } 1472 1473 if (ext_flags & OCFS2_EXT_UNWRITTEN) { 1474 desc->c_unwritten = 1; 1475 desc->c_needs_zero = 1; 1476 } 1477 1478 num_clusters--; 1479 } 1480 1481 ret = 0; 1482 out: 1483 return ret; 1484 } 1485 1486 static int ocfs2_write_begin_inline(struct address_space *mapping, 1487 struct inode *inode, 1488 struct ocfs2_write_ctxt *wc) 1489 { 1490 int ret; 1491 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1492 struct page *page; 1493 handle_t *handle; 1494 struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data; 1495 1496 page = find_or_create_page(mapping, 0, GFP_NOFS); 1497 if (!page) { 1498 ret = -ENOMEM; 1499 mlog_errno(ret); 1500 goto out; 1501 } 1502 /* 1503 * If we don't set w_num_pages then this page won't get unlocked 1504 * and freed on cleanup of the write context. 1505 */ 1506 wc->w_pages[0] = wc->w_target_page = page; 1507 wc->w_num_pages = 1; 1508 1509 handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS); 1510 if (IS_ERR(handle)) { 1511 ret = PTR_ERR(handle); 1512 mlog_errno(ret); 1513 goto out; 1514 } 1515 1516 ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh, 1517 OCFS2_JOURNAL_ACCESS_WRITE); 1518 if (ret) { 1519 ocfs2_commit_trans(osb, handle); 1520 1521 mlog_errno(ret); 1522 goto out; 1523 } 1524 1525 if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)) 1526 ocfs2_set_inode_data_inline(inode, di); 1527 1528 if (!PageUptodate(page)) { 1529 ret = ocfs2_read_inline_data(inode, page, wc->w_di_bh); 1530 if (ret) { 1531 ocfs2_commit_trans(osb, handle); 1532 1533 goto out; 1534 } 1535 } 1536 1537 wc->w_handle = handle; 1538 out: 1539 return ret; 1540 } 1541 1542 int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size) 1543 { 1544 struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data; 1545 1546 if (new_size <= le16_to_cpu(di->id2.i_data.id_count)) 1547 return 1; 1548 return 0; 1549 } 1550 1551 static int ocfs2_try_to_write_inline_data(struct address_space *mapping, 1552 struct inode *inode, loff_t pos, 1553 unsigned len, struct page *mmap_page, 1554 struct ocfs2_write_ctxt *wc) 1555 { 1556 int ret, written = 0; 1557 loff_t end = pos + len; 1558 struct ocfs2_inode_info *oi = OCFS2_I(inode); 1559 struct ocfs2_dinode *di = NULL; 1560 1561 mlog(0, "Inode %llu, write of %u bytes at off %llu. features: 0x%x\n", 1562 (unsigned long long)oi->ip_blkno, len, (unsigned long long)pos, 1563 oi->ip_dyn_features); 1564 1565 /* 1566 * Handle inodes which already have inline data 1st. 1567 */ 1568 if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) { 1569 if (mmap_page == NULL && 1570 ocfs2_size_fits_inline_data(wc->w_di_bh, end)) 1571 goto do_inline_write; 1572 1573 /* 1574 * The write won't fit - we have to give this inode an 1575 * inline extent list now. 1576 */ 1577 ret = ocfs2_convert_inline_data_to_extents(inode, wc->w_di_bh); 1578 if (ret) 1579 mlog_errno(ret); 1580 goto out; 1581 } 1582 1583 /* 1584 * Check whether the inode can accept inline data. 1585 */ 1586 if (oi->ip_clusters != 0 || i_size_read(inode) != 0) 1587 return 0; 1588 1589 /* 1590 * Check whether the write can fit. 1591 */ 1592 di = (struct ocfs2_dinode *)wc->w_di_bh->b_data; 1593 if (mmap_page || 1594 end > ocfs2_max_inline_data_with_xattr(inode->i_sb, di)) 1595 return 0; 1596 1597 do_inline_write: 1598 ret = ocfs2_write_begin_inline(mapping, inode, wc); 1599 if (ret) { 1600 mlog_errno(ret); 1601 goto out; 1602 } 1603 1604 /* 1605 * This signals to the caller that the data can be written 1606 * inline. 1607 */ 1608 written = 1; 1609 out: 1610 return written ? written : ret; 1611 } 1612 1613 /* 1614 * This function only does anything for file systems which can't 1615 * handle sparse files. 1616 * 1617 * What we want to do here is fill in any hole between the current end 1618 * of allocation and the end of our write. That way the rest of the 1619 * write path can treat it as an non-allocating write, which has no 1620 * special case code for sparse/nonsparse files. 1621 */ 1622 static int ocfs2_expand_nonsparse_inode(struct inode *inode, loff_t pos, 1623 unsigned len, 1624 struct ocfs2_write_ctxt *wc) 1625 { 1626 int ret; 1627 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1628 loff_t newsize = pos + len; 1629 1630 if (ocfs2_sparse_alloc(osb)) 1631 return 0; 1632 1633 if (newsize <= i_size_read(inode)) 1634 return 0; 1635 1636 ret = ocfs2_extend_no_holes(inode, newsize, pos); 1637 if (ret) 1638 mlog_errno(ret); 1639 1640 wc->w_first_new_cpos = 1641 ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode)); 1642 1643 return ret; 1644 } 1645 1646 int ocfs2_write_begin_nolock(struct address_space *mapping, 1647 loff_t pos, unsigned len, unsigned flags, 1648 struct page **pagep, void **fsdata, 1649 struct buffer_head *di_bh, struct page *mmap_page) 1650 { 1651 int ret, cluster_of_pages, credits = OCFS2_INODE_UPDATE_CREDITS; 1652 unsigned int clusters_to_alloc, extents_to_split; 1653 struct ocfs2_write_ctxt *wc; 1654 struct inode *inode = mapping->host; 1655 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1656 struct ocfs2_dinode *di; 1657 struct ocfs2_alloc_context *data_ac = NULL; 1658 struct ocfs2_alloc_context *meta_ac = NULL; 1659 handle_t *handle; 1660 struct ocfs2_extent_tree et; 1661 1662 ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, di_bh); 1663 if (ret) { 1664 mlog_errno(ret); 1665 return ret; 1666 } 1667 1668 if (ocfs2_supports_inline_data(osb)) { 1669 ret = ocfs2_try_to_write_inline_data(mapping, inode, pos, len, 1670 mmap_page, wc); 1671 if (ret == 1) { 1672 ret = 0; 1673 goto success; 1674 } 1675 if (ret < 0) { 1676 mlog_errno(ret); 1677 goto out; 1678 } 1679 } 1680 1681 ret = ocfs2_expand_nonsparse_inode(inode, pos, len, wc); 1682 if (ret) { 1683 mlog_errno(ret); 1684 goto out; 1685 } 1686 1687 ret = ocfs2_check_range_for_refcount(inode, pos, len); 1688 if (ret < 0) { 1689 mlog_errno(ret); 1690 goto out; 1691 } else if (ret == 1) { 1692 ret = ocfs2_refcount_cow(inode, di_bh, 1693 wc->w_cpos, wc->w_clen, UINT_MAX); 1694 if (ret) { 1695 mlog_errno(ret); 1696 goto out; 1697 } 1698 } 1699 1700 ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc, 1701 &extents_to_split); 1702 if (ret) { 1703 mlog_errno(ret); 1704 goto out; 1705 } 1706 1707 di = (struct ocfs2_dinode *)wc->w_di_bh->b_data; 1708 1709 /* 1710 * We set w_target_from, w_target_to here so that 1711 * ocfs2_write_end() knows which range in the target page to 1712 * write out. An allocation requires that we write the entire 1713 * cluster range. 1714 */ 1715 if (clusters_to_alloc || extents_to_split) { 1716 /* 1717 * XXX: We are stretching the limits of 1718 * ocfs2_lock_allocators(). It greatly over-estimates 1719 * the work to be done. 1720 */ 1721 mlog(0, "extend inode %llu, i_size = %lld, di->i_clusters = %u," 1722 " clusters_to_add = %u, extents_to_split = %u\n", 1723 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1724 (long long)i_size_read(inode), le32_to_cpu(di->i_clusters), 1725 clusters_to_alloc, extents_to_split); 1726 1727 ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), 1728 wc->w_di_bh); 1729 ret = ocfs2_lock_allocators(inode, &et, 1730 clusters_to_alloc, extents_to_split, 1731 &data_ac, &meta_ac); 1732 if (ret) { 1733 mlog_errno(ret); 1734 goto out; 1735 } 1736 1737 credits = ocfs2_calc_extend_credits(inode->i_sb, 1738 &di->id2.i_list, 1739 clusters_to_alloc); 1740 1741 } 1742 1743 /* 1744 * We have to zero sparse allocated clusters, unwritten extent clusters, 1745 * and non-sparse clusters we just extended. For non-sparse writes, 1746 * we know zeros will only be needed in the first and/or last cluster. 1747 */ 1748 if (clusters_to_alloc || extents_to_split || 1749 (wc->w_clen && (wc->w_desc[0].c_needs_zero || 1750 wc->w_desc[wc->w_clen - 1].c_needs_zero))) 1751 cluster_of_pages = 1; 1752 else 1753 cluster_of_pages = 0; 1754 1755 ocfs2_set_target_boundaries(osb, wc, pos, len, cluster_of_pages); 1756 1757 handle = ocfs2_start_trans(osb, credits); 1758 if (IS_ERR(handle)) { 1759 ret = PTR_ERR(handle); 1760 mlog_errno(ret); 1761 goto out; 1762 } 1763 1764 wc->w_handle = handle; 1765 1766 if (clusters_to_alloc && vfs_dq_alloc_space_nodirty(inode, 1767 ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc))) { 1768 ret = -EDQUOT; 1769 goto out_commit; 1770 } 1771 /* 1772 * We don't want this to fail in ocfs2_write_end(), so do it 1773 * here. 1774 */ 1775 ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh, 1776 OCFS2_JOURNAL_ACCESS_WRITE); 1777 if (ret) { 1778 mlog_errno(ret); 1779 goto out_quota; 1780 } 1781 1782 /* 1783 * Fill our page array first. That way we've grabbed enough so 1784 * that we can zero and flush if we error after adding the 1785 * extent. 1786 */ 1787 ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos, 1788 cluster_of_pages, mmap_page); 1789 if (ret) { 1790 mlog_errno(ret); 1791 goto out_quota; 1792 } 1793 1794 ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos, 1795 len); 1796 if (ret) { 1797 mlog_errno(ret); 1798 goto out_quota; 1799 } 1800 1801 if (data_ac) 1802 ocfs2_free_alloc_context(data_ac); 1803 if (meta_ac) 1804 ocfs2_free_alloc_context(meta_ac); 1805 1806 success: 1807 *pagep = wc->w_target_page; 1808 *fsdata = wc; 1809 return 0; 1810 out_quota: 1811 if (clusters_to_alloc) 1812 vfs_dq_free_space(inode, 1813 ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc)); 1814 out_commit: 1815 ocfs2_commit_trans(osb, handle); 1816 1817 out: 1818 ocfs2_free_write_ctxt(wc); 1819 1820 if (data_ac) 1821 ocfs2_free_alloc_context(data_ac); 1822 if (meta_ac) 1823 ocfs2_free_alloc_context(meta_ac); 1824 return ret; 1825 } 1826 1827 static int ocfs2_write_begin(struct file *file, struct address_space *mapping, 1828 loff_t pos, unsigned len, unsigned flags, 1829 struct page **pagep, void **fsdata) 1830 { 1831 int ret; 1832 struct buffer_head *di_bh = NULL; 1833 struct inode *inode = mapping->host; 1834 1835 ret = ocfs2_inode_lock(inode, &di_bh, 1); 1836 if (ret) { 1837 mlog_errno(ret); 1838 return ret; 1839 } 1840 1841 /* 1842 * Take alloc sem here to prevent concurrent lookups. That way 1843 * the mapping, zeroing and tree manipulation within 1844 * ocfs2_write() will be safe against ->readpage(). This 1845 * should also serve to lock out allocation from a shared 1846 * writeable region. 1847 */ 1848 down_write(&OCFS2_I(inode)->ip_alloc_sem); 1849 1850 ret = ocfs2_write_begin_nolock(mapping, pos, len, flags, pagep, 1851 fsdata, di_bh, NULL); 1852 if (ret) { 1853 mlog_errno(ret); 1854 goto out_fail; 1855 } 1856 1857 brelse(di_bh); 1858 1859 return 0; 1860 1861 out_fail: 1862 up_write(&OCFS2_I(inode)->ip_alloc_sem); 1863 1864 brelse(di_bh); 1865 ocfs2_inode_unlock(inode, 1); 1866 1867 return ret; 1868 } 1869 1870 static void ocfs2_write_end_inline(struct inode *inode, loff_t pos, 1871 unsigned len, unsigned *copied, 1872 struct ocfs2_dinode *di, 1873 struct ocfs2_write_ctxt *wc) 1874 { 1875 void *kaddr; 1876 1877 if (unlikely(*copied < len)) { 1878 if (!PageUptodate(wc->w_target_page)) { 1879 *copied = 0; 1880 return; 1881 } 1882 } 1883 1884 kaddr = kmap_atomic(wc->w_target_page, KM_USER0); 1885 memcpy(di->id2.i_data.id_data + pos, kaddr + pos, *copied); 1886 kunmap_atomic(kaddr, KM_USER0); 1887 1888 mlog(0, "Data written to inode at offset %llu. " 1889 "id_count = %u, copied = %u, i_dyn_features = 0x%x\n", 1890 (unsigned long long)pos, *copied, 1891 le16_to_cpu(di->id2.i_data.id_count), 1892 le16_to_cpu(di->i_dyn_features)); 1893 } 1894 1895 int ocfs2_write_end_nolock(struct address_space *mapping, 1896 loff_t pos, unsigned len, unsigned copied, 1897 struct page *page, void *fsdata) 1898 { 1899 int i; 1900 unsigned from, to, start = pos & (PAGE_CACHE_SIZE - 1); 1901 struct inode *inode = mapping->host; 1902 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1903 struct ocfs2_write_ctxt *wc = fsdata; 1904 struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data; 1905 handle_t *handle = wc->w_handle; 1906 struct page *tmppage; 1907 1908 if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) { 1909 ocfs2_write_end_inline(inode, pos, len, &copied, di, wc); 1910 goto out_write_size; 1911 } 1912 1913 if (unlikely(copied < len)) { 1914 if (!PageUptodate(wc->w_target_page)) 1915 copied = 0; 1916 1917 ocfs2_zero_new_buffers(wc->w_target_page, start+copied, 1918 start+len); 1919 } 1920 flush_dcache_page(wc->w_target_page); 1921 1922 for(i = 0; i < wc->w_num_pages; i++) { 1923 tmppage = wc->w_pages[i]; 1924 1925 if (tmppage == wc->w_target_page) { 1926 from = wc->w_target_from; 1927 to = wc->w_target_to; 1928 1929 BUG_ON(from > PAGE_CACHE_SIZE || 1930 to > PAGE_CACHE_SIZE || 1931 to < from); 1932 } else { 1933 /* 1934 * Pages adjacent to the target (if any) imply 1935 * a hole-filling write in which case we want 1936 * to flush their entire range. 1937 */ 1938 from = 0; 1939 to = PAGE_CACHE_SIZE; 1940 } 1941 1942 if (page_has_buffers(tmppage)) { 1943 if (ocfs2_should_order_data(inode)) 1944 ocfs2_jbd2_file_inode(wc->w_handle, inode); 1945 block_commit_write(tmppage, from, to); 1946 } 1947 } 1948 1949 out_write_size: 1950 pos += copied; 1951 if (pos > inode->i_size) { 1952 i_size_write(inode, pos); 1953 mark_inode_dirty(inode); 1954 } 1955 inode->i_blocks = ocfs2_inode_sector_count(inode); 1956 di->i_size = cpu_to_le64((u64)i_size_read(inode)); 1957 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1958 di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec); 1959 di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec); 1960 ocfs2_journal_dirty(handle, wc->w_di_bh); 1961 1962 ocfs2_commit_trans(osb, handle); 1963 1964 ocfs2_run_deallocs(osb, &wc->w_dealloc); 1965 1966 ocfs2_free_write_ctxt(wc); 1967 1968 return copied; 1969 } 1970 1971 static int ocfs2_write_end(struct file *file, struct address_space *mapping, 1972 loff_t pos, unsigned len, unsigned copied, 1973 struct page *page, void *fsdata) 1974 { 1975 int ret; 1976 struct inode *inode = mapping->host; 1977 1978 ret = ocfs2_write_end_nolock(mapping, pos, len, copied, page, fsdata); 1979 1980 up_write(&OCFS2_I(inode)->ip_alloc_sem); 1981 ocfs2_inode_unlock(inode, 1); 1982 1983 return ret; 1984 } 1985 1986 const struct address_space_operations ocfs2_aops = { 1987 .readpage = ocfs2_readpage, 1988 .readpages = ocfs2_readpages, 1989 .writepage = ocfs2_writepage, 1990 .write_begin = ocfs2_write_begin, 1991 .write_end = ocfs2_write_end, 1992 .bmap = ocfs2_bmap, 1993 .sync_page = block_sync_page, 1994 .direct_IO = ocfs2_direct_IO, 1995 .invalidatepage = ocfs2_invalidatepage, 1996 .releasepage = ocfs2_releasepage, 1997 .migratepage = buffer_migrate_page, 1998 .is_partially_uptodate = block_is_partially_uptodate, 1999 .error_remove_page = generic_error_remove_page, 2000 }; 2001