Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/fs/mpage.c
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1 /* 2 * fs/mpage.c 3 * 4 * Copyright (C) 2002, Linus Torvalds. 5 * 6 * Contains functions related to preparing and submitting BIOs which contain 7 * multiple pagecache pages. 8 * 9 * 15May2002 Andrew Morton 10 * Initial version 11 * 27Jun2002 axboe@suse.de 12 * use bio_add_page() to build bio's just the right size 13 */ 14 15 #include <linux/kernel.h> 16 #include <linux/export.h> 17 #include <linux/mm.h> 18 #include <linux/kdev_t.h> 19 #include <linux/gfp.h> 20 #include <linux/bio.h> 21 #include <linux/fs.h> 22 #include <linux/buffer_head.h> 23 #include <linux/blkdev.h> 24 #include <linux/highmem.h> 25 #include <linux/prefetch.h> 26 #include <linux/mpage.h> 27 #include <linux/writeback.h> 28 #include <linux/backing-dev.h> 29 #include <linux/pagevec.h> 30 #include <linux/cleancache.h> 31 32 /* 33 * I/O completion handler for multipage BIOs. 34 * 35 * The mpage code never puts partial pages into a BIO (except for end-of-file). 36 * If a page does not map to a contiguous run of blocks then it simply falls 37 * back to block_read_full_page(). 38 * 39 * Why is this? If a page's completion depends on a number of different BIOs 40 * which can complete in any order (or at the same time) then determining the 41 * status of that page is hard. See end_buffer_async_read() for the details. 42 * There is no point in duplicating all that complexity. 43 */ 44 static void mpage_end_io(struct bio *bio, int err) 45 { 46 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 47 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 48 49 do { 50 struct page *page = bvec->bv_page; 51 52 if (--bvec >= bio->bi_io_vec) 53 prefetchw(&bvec->bv_page->flags); 54 if (bio_data_dir(bio) == READ) { 55 if (uptodate) { 56 SetPageUptodate(page); 57 } else { 58 ClearPageUptodate(page); 59 SetPageError(page); 60 } 61 unlock_page(page); 62 } else { /* bio_data_dir(bio) == WRITE */ 63 if (!uptodate) { 64 SetPageError(page); 65 if (page->mapping) 66 set_bit(AS_EIO, &page->mapping->flags); 67 } 68 end_page_writeback(page); 69 } 70 } while (bvec >= bio->bi_io_vec); 71 bio_put(bio); 72 } 73 74 static struct bio *mpage_bio_submit(int rw, struct bio *bio) 75 { 76 bio->bi_end_io = mpage_end_io; 77 submit_bio(rw, bio); 78 return NULL; 79 } 80 81 static struct bio * 82 mpage_alloc(struct block_device *bdev, 83 sector_t first_sector, int nr_vecs, 84 gfp_t gfp_flags) 85 { 86 struct bio *bio; 87 88 bio = bio_alloc(gfp_flags, nr_vecs); 89 90 if (bio == NULL && (current->flags & PF_MEMALLOC)) { 91 while (!bio && (nr_vecs /= 2)) 92 bio = bio_alloc(gfp_flags, nr_vecs); 93 } 94 95 if (bio) { 96 bio->bi_bdev = bdev; 97 bio->bi_sector = first_sector; 98 } 99 return bio; 100 } 101 102 /* 103 * support function for mpage_readpages. The fs supplied get_block might 104 * return an up to date buffer. This is used to map that buffer into 105 * the page, which allows readpage to avoid triggering a duplicate call 106 * to get_block. 107 * 108 * The idea is to avoid adding buffers to pages that don't already have 109 * them. So when the buffer is up to date and the page size == block size, 110 * this marks the page up to date instead of adding new buffers. 111 */ 112 static void 113 map_buffer_to_page(struct page *page, struct buffer_head *bh, int page_block) 114 { 115 struct inode *inode = page->mapping->host; 116 struct buffer_head *page_bh, *head; 117 int block = 0; 118 119 if (!page_has_buffers(page)) { 120 /* 121 * don't make any buffers if there is only one buffer on 122 * the page and the page just needs to be set up to date 123 */ 124 if (inode->i_blkbits == PAGE_CACHE_SHIFT && 125 buffer_uptodate(bh)) { 126 SetPageUptodate(page); 127 return; 128 } 129 create_empty_buffers(page, 1 << inode->i_blkbits, 0); 130 } 131 head = page_buffers(page); 132 page_bh = head; 133 do { 134 if (block == page_block) { 135 page_bh->b_state = bh->b_state; 136 page_bh->b_bdev = bh->b_bdev; 137 page_bh->b_blocknr = bh->b_blocknr; 138 break; 139 } 140 page_bh = page_bh->b_this_page; 141 block++; 142 } while (page_bh != head); 143 } 144 145 /* 146 * This is the worker routine which does all the work of mapping the disk 147 * blocks and constructs largest possible bios, submits them for IO if the 148 * blocks are not contiguous on the disk. 149 * 150 * We pass a buffer_head back and forth and use its buffer_mapped() flag to 151 * represent the validity of its disk mapping and to decide when to do the next 152 * get_block() call. 153 */ 154 static struct bio * 155 do_mpage_readpage(struct bio *bio, struct page *page, unsigned nr_pages, 156 sector_t *last_block_in_bio, struct buffer_head *map_bh, 157 unsigned long *first_logical_block, get_block_t get_block) 158 { 159 struct inode *inode = page->mapping->host; 160 const unsigned blkbits = inode->i_blkbits; 161 const unsigned blocks_per_page = PAGE_CACHE_SIZE >> blkbits; 162 const unsigned blocksize = 1 << blkbits; 163 sector_t block_in_file; 164 sector_t last_block; 165 sector_t last_block_in_file; 166 sector_t blocks[MAX_BUF_PER_PAGE]; 167 unsigned page_block; 168 unsigned first_hole = blocks_per_page; 169 struct block_device *bdev = NULL; 170 int length; 171 int fully_mapped = 1; 172 unsigned nblocks; 173 unsigned relative_block; 174 175 if (page_has_buffers(page)) 176 goto confused; 177 178 block_in_file = (sector_t)page->index << (PAGE_CACHE_SHIFT - blkbits); 179 last_block = block_in_file + nr_pages * blocks_per_page; 180 last_block_in_file = (i_size_read(inode) + blocksize - 1) >> blkbits; 181 if (last_block > last_block_in_file) 182 last_block = last_block_in_file; 183 page_block = 0; 184 185 /* 186 * Map blocks using the result from the previous get_blocks call first. 187 */ 188 nblocks = map_bh->b_size >> blkbits; 189 if (buffer_mapped(map_bh) && block_in_file > *first_logical_block && 190 block_in_file < (*first_logical_block + nblocks)) { 191 unsigned map_offset = block_in_file - *first_logical_block; 192 unsigned last = nblocks - map_offset; 193 194 for (relative_block = 0; ; relative_block++) { 195 if (relative_block == last) { 196 clear_buffer_mapped(map_bh); 197 break; 198 } 199 if (page_block == blocks_per_page) 200 break; 201 blocks[page_block] = map_bh->b_blocknr + map_offset + 202 relative_block; 203 page_block++; 204 block_in_file++; 205 } 206 bdev = map_bh->b_bdev; 207 } 208 209 /* 210 * Then do more get_blocks calls until we are done with this page. 211 */ 212 map_bh->b_page = page; 213 while (page_block < blocks_per_page) { 214 map_bh->b_state = 0; 215 map_bh->b_size = 0; 216 217 if (block_in_file < last_block) { 218 map_bh->b_size = (last_block-block_in_file) << blkbits; 219 if (get_block(inode, block_in_file, map_bh, 0)) 220 goto confused; 221 *first_logical_block = block_in_file; 222 } 223 224 if (!buffer_mapped(map_bh)) { 225 fully_mapped = 0; 226 if (first_hole == blocks_per_page) 227 first_hole = page_block; 228 page_block++; 229 block_in_file++; 230 continue; 231 } 232 233 /* some filesystems will copy data into the page during 234 * the get_block call, in which case we don't want to 235 * read it again. map_buffer_to_page copies the data 236 * we just collected from get_block into the page's buffers 237 * so readpage doesn't have to repeat the get_block call 238 */ 239 if (buffer_uptodate(map_bh)) { 240 map_buffer_to_page(page, map_bh, page_block); 241 goto confused; 242 } 243 244 if (first_hole != blocks_per_page) 245 goto confused; /* hole -> non-hole */ 246 247 /* Contiguous blocks? */ 248 if (page_block && blocks[page_block-1] != map_bh->b_blocknr-1) 249 goto confused; 250 nblocks = map_bh->b_size >> blkbits; 251 for (relative_block = 0; ; relative_block++) { 252 if (relative_block == nblocks) { 253 clear_buffer_mapped(map_bh); 254 break; 255 } else if (page_block == blocks_per_page) 256 break; 257 blocks[page_block] = map_bh->b_blocknr+relative_block; 258 page_block++; 259 block_in_file++; 260 } 261 bdev = map_bh->b_bdev; 262 } 263 264 if (first_hole != blocks_per_page) { 265 zero_user_segment(page, first_hole << blkbits, PAGE_CACHE_SIZE); 266 if (first_hole == 0) { 267 SetPageUptodate(page); 268 unlock_page(page); 269 goto out; 270 } 271 } else if (fully_mapped) { 272 SetPageMappedToDisk(page); 273 } 274 275 if (fully_mapped && blocks_per_page == 1 && !PageUptodate(page) && 276 cleancache_get_page(page) == 0) { 277 SetPageUptodate(page); 278 goto confused; 279 } 280 281 /* 282 * This page will go to BIO. Do we need to send this BIO off first? 283 */ 284 if (bio && (*last_block_in_bio != blocks[0] - 1)) 285 bio = mpage_bio_submit(READ, bio); 286 287 alloc_new: 288 if (bio == NULL) { 289 bio = mpage_alloc(bdev, blocks[0] << (blkbits - 9), 290 min_t(int, nr_pages, bio_get_nr_vecs(bdev)), 291 GFP_KERNEL); 292 if (bio == NULL) 293 goto confused; 294 } 295 296 length = first_hole << blkbits; 297 if (bio_add_page(bio, page, length, 0) < length) { 298 bio = mpage_bio_submit(READ, bio); 299 goto alloc_new; 300 } 301 302 relative_block = block_in_file - *first_logical_block; 303 nblocks = map_bh->b_size >> blkbits; 304 if ((buffer_boundary(map_bh) && relative_block == nblocks) || 305 (first_hole != blocks_per_page)) 306 bio = mpage_bio_submit(READ, bio); 307 else 308 *last_block_in_bio = blocks[blocks_per_page - 1]; 309 out: 310 return bio; 311 312 confused: 313 if (bio) 314 bio = mpage_bio_submit(READ, bio); 315 if (!PageUptodate(page)) 316 block_read_full_page(page, get_block); 317 else 318 unlock_page(page); 319 goto out; 320 } 321 322 /** 323 * mpage_readpages - populate an address space with some pages & start reads against them 324 * @mapping: the address_space 325 * @pages: The address of a list_head which contains the target pages. These 326 * pages have their ->index populated and are otherwise uninitialised. 327 * The page at @pages->prev has the lowest file offset, and reads should be 328 * issued in @pages->prev to @pages->next order. 329 * @nr_pages: The number of pages at *@pages 330 * @get_block: The filesystem's block mapper function. 331 * 332 * This function walks the pages and the blocks within each page, building and 333 * emitting large BIOs. 334 * 335 * If anything unusual happens, such as: 336 * 337 * - encountering a page which has buffers 338 * - encountering a page which has a non-hole after a hole 339 * - encountering a page with non-contiguous blocks 340 * 341 * then this code just gives up and calls the buffer_head-based read function. 342 * It does handle a page which has holes at the end - that is a common case: 343 * the end-of-file on blocksize < PAGE_CACHE_SIZE setups. 344 * 345 * BH_Boundary explanation: 346 * 347 * There is a problem. The mpage read code assembles several pages, gets all 348 * their disk mappings, and then submits them all. That's fine, but obtaining 349 * the disk mappings may require I/O. Reads of indirect blocks, for example. 350 * 351 * So an mpage read of the first 16 blocks of an ext2 file will cause I/O to be 352 * submitted in the following order: 353 * 12 0 1 2 3 4 5 6 7 8 9 10 11 13 14 15 16 354 * 355 * because the indirect block has to be read to get the mappings of blocks 356 * 13,14,15,16. Obviously, this impacts performance. 357 * 358 * So what we do it to allow the filesystem's get_block() function to set 359 * BH_Boundary when it maps block 11. BH_Boundary says: mapping of the block 360 * after this one will require I/O against a block which is probably close to 361 * this one. So you should push what I/O you have currently accumulated. 362 * 363 * This all causes the disk requests to be issued in the correct order. 364 */ 365 int 366 mpage_readpages(struct address_space *mapping, struct list_head *pages, 367 unsigned nr_pages, get_block_t get_block) 368 { 369 struct bio *bio = NULL; 370 unsigned page_idx; 371 sector_t last_block_in_bio = 0; 372 struct buffer_head map_bh; 373 unsigned long first_logical_block = 0; 374 375 map_bh.b_state = 0; 376 map_bh.b_size = 0; 377 for (page_idx = 0; page_idx < nr_pages; page_idx++) { 378 struct page *page = list_entry(pages->prev, struct page, lru); 379 380 prefetchw(&page->flags); 381 list_del(&page->lru); 382 if (!add_to_page_cache_lru(page, mapping, 383 page->index, GFP_KERNEL)) { 384 bio = do_mpage_readpage(bio, page, 385 nr_pages - page_idx, 386 &last_block_in_bio, &map_bh, 387 &first_logical_block, 388 get_block); 389 } 390 page_cache_release(page); 391 } 392 BUG_ON(!list_empty(pages)); 393 if (bio) 394 mpage_bio_submit(READ, bio); 395 return 0; 396 } 397 EXPORT_SYMBOL(mpage_readpages); 398 399 /* 400 * This isn't called much at all 401 */ 402 int mpage_readpage(struct page *page, get_block_t get_block) 403 { 404 struct bio *bio = NULL; 405 sector_t last_block_in_bio = 0; 406 struct buffer_head map_bh; 407 unsigned long first_logical_block = 0; 408 409 map_bh.b_state = 0; 410 map_bh.b_size = 0; 411 bio = do_mpage_readpage(bio, page, 1, &last_block_in_bio, 412 &map_bh, &first_logical_block, get_block); 413 if (bio) 414 mpage_bio_submit(READ, bio); 415 return 0; 416 } 417 EXPORT_SYMBOL(mpage_readpage); 418 419 /* 420 * Writing is not so simple. 421 * 422 * If the page has buffers then they will be used for obtaining the disk 423 * mapping. We only support pages which are fully mapped-and-dirty, with a 424 * special case for pages which are unmapped at the end: end-of-file. 425 * 426 * If the page has no buffers (preferred) then the page is mapped here. 427 * 428 * If all blocks are found to be contiguous then the page can go into the 429 * BIO. Otherwise fall back to the mapping's writepage(). 430 * 431 * FIXME: This code wants an estimate of how many pages are still to be 432 * written, so it can intelligently allocate a suitably-sized BIO. For now, 433 * just allocate full-size (16-page) BIOs. 434 */ 435 436 struct mpage_data { 437 struct bio *bio; 438 sector_t last_block_in_bio; 439 get_block_t *get_block; 440 unsigned use_writepage; 441 }; 442 443 static int __mpage_writepage(struct page *page, struct writeback_control *wbc, 444 void *data) 445 { 446 struct mpage_data *mpd = data; 447 struct bio *bio = mpd->bio; 448 struct address_space *mapping = page->mapping; 449 struct inode *inode = page->mapping->host; 450 const unsigned blkbits = inode->i_blkbits; 451 unsigned long end_index; 452 const unsigned blocks_per_page = PAGE_CACHE_SIZE >> blkbits; 453 sector_t last_block; 454 sector_t block_in_file; 455 sector_t blocks[MAX_BUF_PER_PAGE]; 456 unsigned page_block; 457 unsigned first_unmapped = blocks_per_page; 458 struct block_device *bdev = NULL; 459 int boundary = 0; 460 sector_t boundary_block = 0; 461 struct block_device *boundary_bdev = NULL; 462 int length; 463 struct buffer_head map_bh; 464 loff_t i_size = i_size_read(inode); 465 int ret = 0; 466 467 if (page_has_buffers(page)) { 468 struct buffer_head *head = page_buffers(page); 469 struct buffer_head *bh = head; 470 471 /* If they're all mapped and dirty, do it */ 472 page_block = 0; 473 do { 474 BUG_ON(buffer_locked(bh)); 475 if (!buffer_mapped(bh)) { 476 /* 477 * unmapped dirty buffers are created by 478 * __set_page_dirty_buffers -> mmapped data 479 */ 480 if (buffer_dirty(bh)) 481 goto confused; 482 if (first_unmapped == blocks_per_page) 483 first_unmapped = page_block; 484 continue; 485 } 486 487 if (first_unmapped != blocks_per_page) 488 goto confused; /* hole -> non-hole */ 489 490 if (!buffer_dirty(bh) || !buffer_uptodate(bh)) 491 goto confused; 492 if (page_block) { 493 if (bh->b_blocknr != blocks[page_block-1] + 1) 494 goto confused; 495 } 496 blocks[page_block++] = bh->b_blocknr; 497 boundary = buffer_boundary(bh); 498 if (boundary) { 499 boundary_block = bh->b_blocknr; 500 boundary_bdev = bh->b_bdev; 501 } 502 bdev = bh->b_bdev; 503 } while ((bh = bh->b_this_page) != head); 504 505 if (first_unmapped) 506 goto page_is_mapped; 507 508 /* 509 * Page has buffers, but they are all unmapped. The page was 510 * created by pagein or read over a hole which was handled by 511 * block_read_full_page(). If this address_space is also 512 * using mpage_readpages then this can rarely happen. 513 */ 514 goto confused; 515 } 516 517 /* 518 * The page has no buffers: map it to disk 519 */ 520 BUG_ON(!PageUptodate(page)); 521 block_in_file = (sector_t)page->index << (PAGE_CACHE_SHIFT - blkbits); 522 last_block = (i_size - 1) >> blkbits; 523 map_bh.b_page = page; 524 for (page_block = 0; page_block < blocks_per_page; ) { 525 526 map_bh.b_state = 0; 527 map_bh.b_size = 1 << blkbits; 528 if (mpd->get_block(inode, block_in_file, &map_bh, 1)) 529 goto confused; 530 if (buffer_new(&map_bh)) 531 unmap_underlying_metadata(map_bh.b_bdev, 532 map_bh.b_blocknr); 533 if (buffer_boundary(&map_bh)) { 534 boundary_block = map_bh.b_blocknr; 535 boundary_bdev = map_bh.b_bdev; 536 } 537 if (page_block) { 538 if (map_bh.b_blocknr != blocks[page_block-1] + 1) 539 goto confused; 540 } 541 blocks[page_block++] = map_bh.b_blocknr; 542 boundary = buffer_boundary(&map_bh); 543 bdev = map_bh.b_bdev; 544 if (block_in_file == last_block) 545 break; 546 block_in_file++; 547 } 548 BUG_ON(page_block == 0); 549 550 first_unmapped = page_block; 551 552 page_is_mapped: 553 end_index = i_size >> PAGE_CACHE_SHIFT; 554 if (page->index >= end_index) { 555 /* 556 * The page straddles i_size. It must be zeroed out on each 557 * and every writepage invocation because it may be mmapped. 558 * "A file is mapped in multiples of the page size. For a file 559 * that is not a multiple of the page size, the remaining memory 560 * is zeroed when mapped, and writes to that region are not 561 * written out to the file." 562 */ 563 unsigned offset = i_size & (PAGE_CACHE_SIZE - 1); 564 565 if (page->index > end_index || !offset) 566 goto confused; 567 zero_user_segment(page, offset, PAGE_CACHE_SIZE); 568 } 569 570 /* 571 * This page will go to BIO. Do we need to send this BIO off first? 572 */ 573 if (bio && mpd->last_block_in_bio != blocks[0] - 1) 574 bio = mpage_bio_submit(WRITE, bio); 575 576 alloc_new: 577 if (bio == NULL) { 578 bio = mpage_alloc(bdev, blocks[0] << (blkbits - 9), 579 bio_get_nr_vecs(bdev), GFP_NOFS|__GFP_HIGH); 580 if (bio == NULL) 581 goto confused; 582 } 583 584 /* 585 * Must try to add the page before marking the buffer clean or 586 * the confused fail path above (OOM) will be very confused when 587 * it finds all bh marked clean (i.e. it will not write anything) 588 */ 589 length = first_unmapped << blkbits; 590 if (bio_add_page(bio, page, length, 0) < length) { 591 bio = mpage_bio_submit(WRITE, bio); 592 goto alloc_new; 593 } 594 595 /* 596 * OK, we have our BIO, so we can now mark the buffers clean. Make 597 * sure to only clean buffers which we know we'll be writing. 598 */ 599 if (page_has_buffers(page)) { 600 struct buffer_head *head = page_buffers(page); 601 struct buffer_head *bh = head; 602 unsigned buffer_counter = 0; 603 604 do { 605 if (buffer_counter++ == first_unmapped) 606 break; 607 clear_buffer_dirty(bh); 608 bh = bh->b_this_page; 609 } while (bh != head); 610 611 /* 612 * we cannot drop the bh if the page is not uptodate 613 * or a concurrent readpage would fail to serialize with the bh 614 * and it would read from disk before we reach the platter. 615 */ 616 if (buffer_heads_over_limit && PageUptodate(page)) 617 try_to_free_buffers(page); 618 } 619 620 BUG_ON(PageWriteback(page)); 621 set_page_writeback(page); 622 unlock_page(page); 623 if (boundary || (first_unmapped != blocks_per_page)) { 624 bio = mpage_bio_submit(WRITE, bio); 625 if (boundary_block) { 626 write_boundary_block(boundary_bdev, 627 boundary_block, 1 << blkbits); 628 } 629 } else { 630 mpd->last_block_in_bio = blocks[blocks_per_page - 1]; 631 } 632 goto out; 633 634 confused: 635 if (bio) 636 bio = mpage_bio_submit(WRITE, bio); 637 638 if (mpd->use_writepage) { 639 ret = mapping->a_ops->writepage(page, wbc); 640 } else { 641 ret = -EAGAIN; 642 goto out; 643 } 644 /* 645 * The caller has a ref on the inode, so *mapping is stable 646 */ 647 mapping_set_error(mapping, ret); 648 out: 649 mpd->bio = bio; 650 return ret; 651 } 652 653 /** 654 * mpage_writepages - walk the list of dirty pages of the given address space & writepage() all of them 655 * @mapping: address space structure to write 656 * @wbc: subtract the number of written pages from *@wbc->nr_to_write 657 * @get_block: the filesystem's block mapper function. 658 * If this is NULL then use a_ops->writepage. Otherwise, go 659 * direct-to-BIO. 660 * 661 * This is a library function, which implements the writepages() 662 * address_space_operation. 663 * 664 * If a page is already under I/O, generic_writepages() skips it, even 665 * if it's dirty. This is desirable behaviour for memory-cleaning writeback, 666 * but it is INCORRECT for data-integrity system calls such as fsync(). fsync() 667 * and msync() need to guarantee that all the data which was dirty at the time 668 * the call was made get new I/O started against them. If wbc->sync_mode is 669 * WB_SYNC_ALL then we were called for data integrity and we must wait for 670 * existing IO to complete. 671 */ 672 int 673 mpage_writepages(struct address_space *mapping, 674 struct writeback_control *wbc, get_block_t get_block) 675 { 676 struct blk_plug plug; 677 int ret; 678 679 blk_start_plug(&plug); 680 681 if (!get_block) 682 ret = generic_writepages(mapping, wbc); 683 else { 684 struct mpage_data mpd = { 685 .bio = NULL, 686 .last_block_in_bio = 0, 687 .get_block = get_block, 688 .use_writepage = 1, 689 }; 690 691 ret = write_cache_pages(mapping, wbc, __mpage_writepage, &mpd); 692 if (mpd.bio) 693 mpage_bio_submit(WRITE, mpd.bio); 694 } 695 blk_finish_plug(&plug); 696 return ret; 697 } 698 EXPORT_SYMBOL(mpage_writepages); 699 700 int mpage_writepage(struct page *page, get_block_t get_block, 701 struct writeback_control *wbc) 702 { 703 struct mpage_data mpd = { 704 .bio = NULL, 705 .last_block_in_bio = 0, 706 .get_block = get_block, 707 .use_writepage = 0, 708 }; 709 int ret = __mpage_writepage(page, wbc, &mpd); 710 if (mpd.bio) 711 mpage_bio_submit(WRITE, mpd.bio); 712 return ret; 713 } 714 EXPORT_SYMBOL(mpage_writepage);
Cache object: 33cd3cd30743a87ebbcaf99337f8f6de
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