1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 1991, 1992 Linus Torvalds 4 * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE 5 * Copyright (C) 2016 - 2020 Christoph Hellwig 6 */ 7 #include <linux/init.h> 8 #include <linux/mm.h> 9 #include <linux/blkdev.h> 10 #include <linux/buffer_head.h> 11 #include <linux/mpage.h> 12 #include <linux/uio.h> 13 #include <linux/namei.h> 14 #include <linux/task_io_accounting_ops.h> 15 #include <linux/falloc.h> 16 #include <linux/suspend.h> 17 #include <linux/fs.h> 18 #include <linux/module.h> 19 #include "blk.h" 20 21 static inline struct inode *bdev_file_inode(struct file *file) 22 { 23 return file->f_mapping->host; 24 } 25 26 static int blkdev_get_block(struct inode *inode, sector_t iblock, 27 struct buffer_head *bh, int create) 28 { 29 bh->b_bdev = I_BDEV(inode); 30 bh->b_blocknr = iblock; 31 set_buffer_mapped(bh); 32 return 0; 33 } 34 35 static unsigned int dio_bio_write_op(struct kiocb *iocb) 36 { 37 unsigned int op = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE; 38 39 /* avoid the need for a I/O completion work item */ 40 if (iocb->ki_flags & IOCB_DSYNC) 41 op |= REQ_FUA; 42 return op; 43 } 44 45 #define DIO_INLINE_BIO_VECS 4 46 47 static void blkdev_bio_end_io_simple(struct bio *bio) 48 { 49 struct task_struct *waiter = bio->bi_private; 50 51 WRITE_ONCE(bio->bi_private, NULL); 52 blk_wake_io_task(waiter); 53 } 54 55 static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb, 56 struct iov_iter *iter, unsigned int nr_pages) 57 { 58 struct block_device *bdev = iocb->ki_filp->private_data; 59 struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *vecs; 60 loff_t pos = iocb->ki_pos; 61 bool should_dirty = false; 62 struct bio bio; 63 ssize_t ret; 64 65 if ((pos | iov_iter_alignment(iter)) & 66 (bdev_logical_block_size(bdev) - 1)) 67 return -EINVAL; 68 69 if (nr_pages <= DIO_INLINE_BIO_VECS) 70 vecs = inline_vecs; 71 else { 72 vecs = kmalloc_array(nr_pages, sizeof(struct bio_vec), 73 GFP_KERNEL); 74 if (!vecs) 75 return -ENOMEM; 76 } 77 78 if (iov_iter_rw(iter) == READ) { 79 bio_init(&bio, bdev, vecs, nr_pages, REQ_OP_READ); 80 if (iter_is_iovec(iter)) 81 should_dirty = true; 82 } else { 83 bio_init(&bio, bdev, vecs, nr_pages, dio_bio_write_op(iocb)); 84 } 85 bio.bi_iter.bi_sector = pos >> SECTOR_SHIFT; 86 bio.bi_write_hint = iocb->ki_hint; 87 bio.bi_private = current; 88 bio.bi_end_io = blkdev_bio_end_io_simple; 89 bio.bi_ioprio = iocb->ki_ioprio; 90 91 ret = bio_iov_iter_get_pages(&bio, iter); 92 if (unlikely(ret)) 93 goto out; 94 ret = bio.bi_iter.bi_size; 95 96 if (iov_iter_rw(iter) == WRITE) 97 task_io_account_write(ret); 98 99 if (iocb->ki_flags & IOCB_NOWAIT) 100 bio.bi_opf |= REQ_NOWAIT; 101 if (iocb->ki_flags & IOCB_HIPRI) 102 bio_set_polled(&bio, iocb); 103 104 submit_bio(&bio); 105 for (;;) { 106 set_current_state(TASK_UNINTERRUPTIBLE); 107 if (!READ_ONCE(bio.bi_private)) 108 break; 109 if (!(iocb->ki_flags & IOCB_HIPRI) || !bio_poll(&bio, NULL, 0)) 110 blk_io_schedule(); 111 } 112 __set_current_state(TASK_RUNNING); 113 114 bio_release_pages(&bio, should_dirty); 115 if (unlikely(bio.bi_status)) 116 ret = blk_status_to_errno(bio.bi_status); 117 118 out: 119 if (vecs != inline_vecs) 120 kfree(vecs); 121 122 bio_uninit(&bio); 123 124 return ret; 125 } 126 127 enum { 128 DIO_SHOULD_DIRTY = 1, 129 DIO_IS_SYNC = 2, 130 }; 131 132 struct blkdev_dio { 133 union { 134 struct kiocb *iocb; 135 struct task_struct *waiter; 136 }; 137 size_t size; 138 atomic_t ref; 139 unsigned int flags; 140 struct bio bio ____cacheline_aligned_in_smp; 141 }; 142 143 static struct bio_set blkdev_dio_pool; 144 145 static void blkdev_bio_end_io(struct bio *bio) 146 { 147 struct blkdev_dio *dio = bio->bi_private; 148 bool should_dirty = dio->flags & DIO_SHOULD_DIRTY; 149 150 if (bio->bi_status && !dio->bio.bi_status) 151 dio->bio.bi_status = bio->bi_status; 152 153 if (atomic_dec_and_test(&dio->ref)) { 154 if (!(dio->flags & DIO_IS_SYNC)) { 155 struct kiocb *iocb = dio->iocb; 156 ssize_t ret; 157 158 WRITE_ONCE(iocb->private, NULL); 159 160 if (likely(!dio->bio.bi_status)) { 161 ret = dio->size; 162 iocb->ki_pos += ret; 163 } else { 164 ret = blk_status_to_errno(dio->bio.bi_status); 165 } 166 167 dio->iocb->ki_complete(iocb, ret); 168 bio_put(&dio->bio); 169 } else { 170 struct task_struct *waiter = dio->waiter; 171 172 WRITE_ONCE(dio->waiter, NULL); 173 blk_wake_io_task(waiter); 174 } 175 } 176 177 if (should_dirty) { 178 bio_check_pages_dirty(bio); 179 } else { 180 bio_release_pages(bio, false); 181 bio_put(bio); 182 } 183 } 184 185 static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, 186 unsigned int nr_pages) 187 { 188 struct block_device *bdev = iocb->ki_filp->private_data; 189 struct blk_plug plug; 190 struct blkdev_dio *dio; 191 struct bio *bio; 192 bool is_read = (iov_iter_rw(iter) == READ), is_sync; 193 unsigned int opf = is_read ? REQ_OP_READ : dio_bio_write_op(iocb); 194 loff_t pos = iocb->ki_pos; 195 int ret = 0; 196 197 if ((pos | iov_iter_alignment(iter)) & 198 (bdev_logical_block_size(bdev) - 1)) 199 return -EINVAL; 200 201 bio = bio_alloc_kiocb(iocb, bdev, nr_pages, opf, &blkdev_dio_pool); 202 203 dio = container_of(bio, struct blkdev_dio, bio); 204 atomic_set(&dio->ref, 1); 205 /* 206 * Grab an extra reference to ensure the dio structure which is embedded 207 * into the first bio stays around. 208 */ 209 bio_get(bio); 210 211 is_sync = is_sync_kiocb(iocb); 212 if (is_sync) { 213 dio->flags = DIO_IS_SYNC; 214 dio->waiter = current; 215 } else { 216 dio->flags = 0; 217 dio->iocb = iocb; 218 } 219 220 dio->size = 0; 221 if (is_read && iter_is_iovec(iter)) 222 dio->flags |= DIO_SHOULD_DIRTY; 223 224 blk_start_plug(&plug); 225 226 for (;;) { 227 bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT; 228 bio->bi_write_hint = iocb->ki_hint; 229 bio->bi_private = dio; 230 bio->bi_end_io = blkdev_bio_end_io; 231 bio->bi_ioprio = iocb->ki_ioprio; 232 233 ret = bio_iov_iter_get_pages(bio, iter); 234 if (unlikely(ret)) { 235 bio->bi_status = BLK_STS_IOERR; 236 bio_endio(bio); 237 break; 238 } 239 240 if (is_read) { 241 if (dio->flags & DIO_SHOULD_DIRTY) 242 bio_set_pages_dirty(bio); 243 } else { 244 task_io_account_write(bio->bi_iter.bi_size); 245 } 246 if (iocb->ki_flags & IOCB_NOWAIT) 247 bio->bi_opf |= REQ_NOWAIT; 248 249 dio->size += bio->bi_iter.bi_size; 250 pos += bio->bi_iter.bi_size; 251 252 nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS); 253 if (!nr_pages) { 254 submit_bio(bio); 255 break; 256 } 257 atomic_inc(&dio->ref); 258 submit_bio(bio); 259 bio = bio_alloc(bdev, nr_pages, opf, GFP_KERNEL); 260 } 261 262 blk_finish_plug(&plug); 263 264 if (!is_sync) 265 return -EIOCBQUEUED; 266 267 for (;;) { 268 set_current_state(TASK_UNINTERRUPTIBLE); 269 if (!READ_ONCE(dio->waiter)) 270 break; 271 blk_io_schedule(); 272 } 273 __set_current_state(TASK_RUNNING); 274 275 if (!ret) 276 ret = blk_status_to_errno(dio->bio.bi_status); 277 if (likely(!ret)) 278 ret = dio->size; 279 280 bio_put(&dio->bio); 281 return ret; 282 } 283 284 static void blkdev_bio_end_io_async(struct bio *bio) 285 { 286 struct blkdev_dio *dio = container_of(bio, struct blkdev_dio, bio); 287 struct kiocb *iocb = dio->iocb; 288 ssize_t ret; 289 290 WRITE_ONCE(iocb->private, NULL); 291 292 if (likely(!bio->bi_status)) { 293 ret = dio->size; 294 iocb->ki_pos += ret; 295 } else { 296 ret = blk_status_to_errno(bio->bi_status); 297 } 298 299 iocb->ki_complete(iocb, ret); 300 301 if (dio->flags & DIO_SHOULD_DIRTY) { 302 bio_check_pages_dirty(bio); 303 } else { 304 bio_release_pages(bio, false); 305 bio_put(bio); 306 } 307 } 308 309 static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb, 310 struct iov_iter *iter, 311 unsigned int nr_pages) 312 { 313 struct block_device *bdev = iocb->ki_filp->private_data; 314 bool is_read = iov_iter_rw(iter) == READ; 315 unsigned int opf = is_read ? REQ_OP_READ : dio_bio_write_op(iocb); 316 struct blkdev_dio *dio; 317 struct bio *bio; 318 loff_t pos = iocb->ki_pos; 319 int ret = 0; 320 321 if ((pos | iov_iter_alignment(iter)) & 322 (bdev_logical_block_size(bdev) - 1)) 323 return -EINVAL; 324 325 bio = bio_alloc_kiocb(iocb, bdev, nr_pages, opf, &blkdev_dio_pool); 326 dio = container_of(bio, struct blkdev_dio, bio); 327 dio->flags = 0; 328 dio->iocb = iocb; 329 bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT; 330 bio->bi_write_hint = iocb->ki_hint; 331 bio->bi_end_io = blkdev_bio_end_io_async; 332 bio->bi_ioprio = iocb->ki_ioprio; 333 334 if (iov_iter_is_bvec(iter)) { 335 /* 336 * Users don't rely on the iterator being in any particular 337 * state for async I/O returning -EIOCBQUEUED, hence we can 338 * avoid expensive iov_iter_advance(). Bypass 339 * bio_iov_iter_get_pages() and set the bvec directly. 340 */ 341 bio_iov_bvec_set(bio, iter); 342 } else { 343 ret = bio_iov_iter_get_pages(bio, iter); 344 if (unlikely(ret)) { 345 bio_put(bio); 346 return ret; 347 } 348 } 349 dio->size = bio->bi_iter.bi_size; 350 351 if (is_read) { 352 if (iter_is_iovec(iter)) { 353 dio->flags |= DIO_SHOULD_DIRTY; 354 bio_set_pages_dirty(bio); 355 } 356 } else { 357 task_io_account_write(bio->bi_iter.bi_size); 358 } 359 360 if (iocb->ki_flags & IOCB_HIPRI) { 361 bio->bi_opf |= REQ_POLLED | REQ_NOWAIT; 362 submit_bio(bio); 363 WRITE_ONCE(iocb->private, bio); 364 } else { 365 if (iocb->ki_flags & IOCB_NOWAIT) 366 bio->bi_opf |= REQ_NOWAIT; 367 submit_bio(bio); 368 } 369 return -EIOCBQUEUED; 370 } 371 372 static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 373 { 374 unsigned int nr_pages; 375 376 if (!iov_iter_count(iter)) 377 return 0; 378 379 nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS + 1); 380 if (likely(nr_pages <= BIO_MAX_VECS)) { 381 if (is_sync_kiocb(iocb)) 382 return __blkdev_direct_IO_simple(iocb, iter, nr_pages); 383 return __blkdev_direct_IO_async(iocb, iter, nr_pages); 384 } 385 return __blkdev_direct_IO(iocb, iter, bio_max_segs(nr_pages)); 386 } 387 388 static int blkdev_writepage(struct page *page, struct writeback_control *wbc) 389 { 390 return block_write_full_page(page, blkdev_get_block, wbc); 391 } 392 393 static int blkdev_readpage(struct file * file, struct page * page) 394 { 395 return block_read_full_page(page, blkdev_get_block); 396 } 397 398 static void blkdev_readahead(struct readahead_control *rac) 399 { 400 mpage_readahead(rac, blkdev_get_block); 401 } 402 403 static int blkdev_write_begin(struct file *file, struct address_space *mapping, 404 loff_t pos, unsigned len, unsigned flags, struct page **pagep, 405 void **fsdata) 406 { 407 return block_write_begin(mapping, pos, len, flags, pagep, 408 blkdev_get_block); 409 } 410 411 static int blkdev_write_end(struct file *file, struct address_space *mapping, 412 loff_t pos, unsigned len, unsigned copied, struct page *page, 413 void *fsdata) 414 { 415 int ret; 416 ret = block_write_end(file, mapping, pos, len, copied, page, fsdata); 417 418 unlock_page(page); 419 put_page(page); 420 421 return ret; 422 } 423 424 static int blkdev_writepages(struct address_space *mapping, 425 struct writeback_control *wbc) 426 { 427 return generic_writepages(mapping, wbc); 428 } 429 430 const struct address_space_operations def_blk_aops = { 431 .dirty_folio = block_dirty_folio, 432 .invalidate_folio = block_invalidate_folio, 433 .readpage = blkdev_readpage, 434 .readahead = blkdev_readahead, 435 .writepage = blkdev_writepage, 436 .write_begin = blkdev_write_begin, 437 .write_end = blkdev_write_end, 438 .writepages = blkdev_writepages, 439 .direct_IO = blkdev_direct_IO, 440 .migratepage = buffer_migrate_page_norefs, 441 .is_dirty_writeback = buffer_check_dirty_writeback, 442 }; 443 444 /* 445 * for a block special file file_inode(file)->i_size is zero 446 * so we compute the size by hand (just as in block_read/write above) 447 */ 448 static loff_t blkdev_llseek(struct file *file, loff_t offset, int whence) 449 { 450 struct inode *bd_inode = bdev_file_inode(file); 451 loff_t retval; 452 453 inode_lock(bd_inode); 454 retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode)); 455 inode_unlock(bd_inode); 456 return retval; 457 } 458 459 static int blkdev_fsync(struct file *filp, loff_t start, loff_t end, 460 int datasync) 461 { 462 struct block_device *bdev = filp->private_data; 463 int error; 464 465 error = file_write_and_wait_range(filp, start, end); 466 if (error) 467 return error; 468 469 /* 470 * There is no need to serialise calls to blkdev_issue_flush with 471 * i_mutex and doing so causes performance issues with concurrent 472 * O_SYNC writers to a block device. 473 */ 474 error = blkdev_issue_flush(bdev); 475 if (error == -EOPNOTSUPP) 476 error = 0; 477 478 return error; 479 } 480 481 static int blkdev_open(struct inode *inode, struct file *filp) 482 { 483 struct block_device *bdev; 484 485 /* 486 * Preserve backwards compatibility and allow large file access 487 * even if userspace doesn't ask for it explicitly. Some mkfs 488 * binary needs it. We might want to drop this workaround 489 * during an unstable branch. 490 */ 491 filp->f_flags |= O_LARGEFILE; 492 filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC; 493 494 if (filp->f_flags & O_NDELAY) 495 filp->f_mode |= FMODE_NDELAY; 496 if (filp->f_flags & O_EXCL) 497 filp->f_mode |= FMODE_EXCL; 498 if ((filp->f_flags & O_ACCMODE) == 3) 499 filp->f_mode |= FMODE_WRITE_IOCTL; 500 501 bdev = blkdev_get_by_dev(inode->i_rdev, filp->f_mode, filp); 502 if (IS_ERR(bdev)) 503 return PTR_ERR(bdev); 504 505 filp->private_data = bdev; 506 filp->f_mapping = bdev->bd_inode->i_mapping; 507 filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping); 508 return 0; 509 } 510 511 static int blkdev_close(struct inode *inode, struct file *filp) 512 { 513 struct block_device *bdev = filp->private_data; 514 515 blkdev_put(bdev, filp->f_mode); 516 return 0; 517 } 518 519 /* 520 * Write data to the block device. Only intended for the block device itself 521 * and the raw driver which basically is a fake block device. 522 * 523 * Does not take i_mutex for the write and thus is not for general purpose 524 * use. 525 */ 526 static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) 527 { 528 struct block_device *bdev = iocb->ki_filp->private_data; 529 struct inode *bd_inode = bdev->bd_inode; 530 loff_t size = bdev_nr_bytes(bdev); 531 struct blk_plug plug; 532 size_t shorted = 0; 533 ssize_t ret; 534 535 if (bdev_read_only(bdev)) 536 return -EPERM; 537 538 if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode->i_rdev)) 539 return -ETXTBSY; 540 541 if (!iov_iter_count(from)) 542 return 0; 543 544 if (iocb->ki_pos >= size) 545 return -ENOSPC; 546 547 if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT) 548 return -EOPNOTSUPP; 549 550 size -= iocb->ki_pos; 551 if (iov_iter_count(from) > size) { 552 shorted = iov_iter_count(from) - size; 553 iov_iter_truncate(from, size); 554 } 555 556 blk_start_plug(&plug); 557 ret = __generic_file_write_iter(iocb, from); 558 if (ret > 0) 559 ret = generic_write_sync(iocb, ret); 560 iov_iter_reexpand(from, iov_iter_count(from) + shorted); 561 blk_finish_plug(&plug); 562 return ret; 563 } 564 565 static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to) 566 { 567 struct block_device *bdev = iocb->ki_filp->private_data; 568 loff_t size = bdev_nr_bytes(bdev); 569 loff_t pos = iocb->ki_pos; 570 size_t shorted = 0; 571 ssize_t ret = 0; 572 size_t count; 573 574 if (unlikely(pos + iov_iter_count(to) > size)) { 575 if (pos >= size) 576 return 0; 577 size -= pos; 578 shorted = iov_iter_count(to) - size; 579 iov_iter_truncate(to, size); 580 } 581 582 count = iov_iter_count(to); 583 if (!count) 584 goto reexpand; /* skip atime */ 585 586 if (iocb->ki_flags & IOCB_DIRECT) { 587 struct address_space *mapping = iocb->ki_filp->f_mapping; 588 589 if (iocb->ki_flags & IOCB_NOWAIT) { 590 if (filemap_range_needs_writeback(mapping, pos, 591 pos + count - 1)) { 592 ret = -EAGAIN; 593 goto reexpand; 594 } 595 } else { 596 ret = filemap_write_and_wait_range(mapping, pos, 597 pos + count - 1); 598 if (ret < 0) 599 goto reexpand; 600 } 601 602 file_accessed(iocb->ki_filp); 603 604 ret = blkdev_direct_IO(iocb, to); 605 if (ret >= 0) { 606 iocb->ki_pos += ret; 607 count -= ret; 608 } 609 iov_iter_revert(to, count - iov_iter_count(to)); 610 if (ret < 0 || !count) 611 goto reexpand; 612 } 613 614 ret = filemap_read(iocb, to, ret); 615 616 reexpand: 617 if (unlikely(shorted)) 618 iov_iter_reexpand(to, iov_iter_count(to) + shorted); 619 return ret; 620 } 621 622 #define BLKDEV_FALLOC_FL_SUPPORTED \ 623 (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \ 624 FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE) 625 626 static long blkdev_fallocate(struct file *file, int mode, loff_t start, 627 loff_t len) 628 { 629 struct inode *inode = bdev_file_inode(file); 630 struct block_device *bdev = I_BDEV(inode); 631 loff_t end = start + len - 1; 632 loff_t isize; 633 int error; 634 635 /* Fail if we don't recognize the flags. */ 636 if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED) 637 return -EOPNOTSUPP; 638 639 /* Don't go off the end of the device. */ 640 isize = bdev_nr_bytes(bdev); 641 if (start >= isize) 642 return -EINVAL; 643 if (end >= isize) { 644 if (mode & FALLOC_FL_KEEP_SIZE) { 645 len = isize - start; 646 end = start + len - 1; 647 } else 648 return -EINVAL; 649 } 650 651 /* 652 * Don't allow IO that isn't aligned to logical block size. 653 */ 654 if ((start | len) & (bdev_logical_block_size(bdev) - 1)) 655 return -EINVAL; 656 657 filemap_invalidate_lock(inode->i_mapping); 658 659 /* Invalidate the page cache, including dirty pages. */ 660 error = truncate_bdev_range(bdev, file->f_mode, start, end); 661 if (error) 662 goto fail; 663 664 switch (mode) { 665 case FALLOC_FL_ZERO_RANGE: 666 case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE: 667 error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, 668 len >> SECTOR_SHIFT, GFP_KERNEL, 669 BLKDEV_ZERO_NOUNMAP); 670 break; 671 case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE: 672 error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, 673 len >> SECTOR_SHIFT, GFP_KERNEL, 674 BLKDEV_ZERO_NOFALLBACK); 675 break; 676 case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE: 677 error = blkdev_issue_discard(bdev, start >> SECTOR_SHIFT, 678 len >> SECTOR_SHIFT, GFP_KERNEL, 0); 679 break; 680 default: 681 error = -EOPNOTSUPP; 682 } 683 684 fail: 685 filemap_invalidate_unlock(inode->i_mapping); 686 return error; 687 } 688 689 const struct file_operations def_blk_fops = { 690 .open = blkdev_open, 691 .release = blkdev_close, 692 .llseek = blkdev_llseek, 693 .read_iter = blkdev_read_iter, 694 .write_iter = blkdev_write_iter, 695 .iopoll = iocb_bio_iopoll, 696 .mmap = generic_file_mmap, 697 .fsync = blkdev_fsync, 698 .unlocked_ioctl = blkdev_ioctl, 699 #ifdef CONFIG_COMPAT 700 .compat_ioctl = compat_blkdev_ioctl, 701 #endif 702 .splice_read = generic_file_splice_read, 703 .splice_write = iter_file_splice_write, 704 .fallocate = blkdev_fallocate, 705 }; 706 707 static __init int blkdev_init(void) 708 { 709 return bioset_init(&blkdev_dio_pool, 4, 710 offsetof(struct blkdev_dio, bio), 711 BIOSET_NEED_BVECS|BIOSET_PERCPU_CACHE); 712 } 713 module_init(blkdev_init); 714