1 /* 2 * linux/fs/nfs/blocklayout/blocklayout.c 3 * 4 * Module for the NFSv4.1 pNFS block layout driver. 5 * 6 * Copyright (c) 2006 The Regents of the University of Michigan. 7 * All rights reserved. 8 * 9 * Andy Adamson <andros@citi.umich.edu> 10 * Fred Isaman <iisaman@umich.edu> 11 * 12 * permission is granted to use, copy, create derivative works and 13 * redistribute this software and such derivative works for any purpose, 14 * so long as the name of the university of michigan is not used in 15 * any advertising or publicity pertaining to the use or distribution 16 * of this software without specific, written prior authorization. if 17 * the above copyright notice or any other identification of the 18 * university of michigan is included in any copy of any portion of 19 * this software, then the disclaimer below must also be included. 20 * 21 * this software is provided as is, without representation from the 22 * university of michigan as to its fitness for any purpose, and without 23 * warranty by the university of michigan of any kind, either express 24 * or implied, including without limitation the implied warranties of 25 * merchantability and fitness for a particular purpose. the regents 26 * of the university of michigan shall not be liable for any damages, 27 * including special, indirect, incidental, or consequential damages, 28 * with respect to any claim arising out or in connection with the use 29 * of the software, even if it has been or is hereafter advised of the 30 * possibility of such damages. 31 */ 32 33 #include <linux/module.h> 34 #include <linux/init.h> 35 #include <linux/mount.h> 36 #include <linux/namei.h> 37 #include <linux/bio.h> /* struct bio */ 38 #include <linux/prefetch.h> 39 #include <linux/pagevec.h> 40 41 #include "../pnfs.h" 42 #include "../nfs4session.h" 43 #include "../internal.h" 44 #include "blocklayout.h" 45 46 #define NFSDBG_FACILITY NFSDBG_PNFS_LD 47 48 MODULE_LICENSE("GPL"); 49 MODULE_AUTHOR("Andy Adamson <andros@citi.umich.edu>"); 50 MODULE_DESCRIPTION("The NFSv4.1 pNFS Block layout driver"); 51 52 static bool is_hole(struct pnfs_block_extent *be) 53 { 54 switch (be->be_state) { 55 case PNFS_BLOCK_NONE_DATA: 56 return true; 57 case PNFS_BLOCK_INVALID_DATA: 58 return be->be_tag ? false : true; 59 default: 60 return false; 61 } 62 } 63 64 /* The data we are handed might be spread across several bios. We need 65 * to track when the last one is finished. 66 */ 67 struct parallel_io { 68 struct kref refcnt; 69 void (*pnfs_callback) (void *data); 70 void *data; 71 }; 72 73 static inline struct parallel_io *alloc_parallel(void *data) 74 { 75 struct parallel_io *rv; 76 77 rv = kmalloc(sizeof(*rv), GFP_NOFS); 78 if (rv) { 79 rv->data = data; 80 kref_init(&rv->refcnt); 81 } 82 return rv; 83 } 84 85 static inline void get_parallel(struct parallel_io *p) 86 { 87 kref_get(&p->refcnt); 88 } 89 90 static void destroy_parallel(struct kref *kref) 91 { 92 struct parallel_io *p = container_of(kref, struct parallel_io, refcnt); 93 94 dprintk("%s enter\n", __func__); 95 p->pnfs_callback(p->data); 96 kfree(p); 97 } 98 99 static inline void put_parallel(struct parallel_io *p) 100 { 101 kref_put(&p->refcnt, destroy_parallel); 102 } 103 104 static struct bio * 105 bl_submit_bio(int rw, struct bio *bio) 106 { 107 if (bio) { 108 get_parallel(bio->bi_private); 109 dprintk("%s submitting %s bio %u@%llu\n", __func__, 110 rw == READ ? "read" : "write", bio->bi_iter.bi_size, 111 (unsigned long long)bio->bi_iter.bi_sector); 112 submit_bio(rw, bio); 113 } 114 return NULL; 115 } 116 117 static struct bio * 118 bl_alloc_init_bio(int npg, struct block_device *bdev, sector_t disk_sector, 119 void (*end_io)(struct bio *, int err), struct parallel_io *par) 120 { 121 struct bio *bio; 122 123 npg = min(npg, BIO_MAX_PAGES); 124 bio = bio_alloc(GFP_NOIO, npg); 125 if (!bio && (current->flags & PF_MEMALLOC)) { 126 while (!bio && (npg /= 2)) 127 bio = bio_alloc(GFP_NOIO, npg); 128 } 129 130 if (bio) { 131 bio->bi_iter.bi_sector = disk_sector; 132 bio->bi_bdev = bdev; 133 bio->bi_end_io = end_io; 134 bio->bi_private = par; 135 } 136 return bio; 137 } 138 139 static struct bio * 140 do_add_page_to_bio(struct bio *bio, int npg, int rw, sector_t isect, 141 struct page *page, struct pnfs_block_dev_map *map, 142 struct pnfs_block_extent *be, 143 void (*end_io)(struct bio *, int err), 144 struct parallel_io *par, unsigned int offset, int *len) 145 { 146 struct pnfs_block_dev *dev = 147 container_of(be->be_device, struct pnfs_block_dev, node); 148 u64 disk_addr, end; 149 150 dprintk("%s: npg %d rw %d isect %llu offset %u len %d\n", __func__, 151 npg, rw, (unsigned long long)isect, offset, *len); 152 153 /* translate to device offset */ 154 isect += be->be_v_offset; 155 isect -= be->be_f_offset; 156 157 /* translate to physical disk offset */ 158 disk_addr = (u64)isect << SECTOR_SHIFT; 159 if (disk_addr < map->start || disk_addr >= map->start + map->len) { 160 if (!dev->map(dev, disk_addr, map)) 161 return ERR_PTR(-EIO); 162 bio = bl_submit_bio(rw, bio); 163 } 164 disk_addr += map->disk_offset; 165 disk_addr -= map->start; 166 167 /* limit length to what the device mapping allows */ 168 end = disk_addr + *len; 169 if (end >= map->start + map->len) 170 *len = map->start + map->len - disk_addr; 171 172 retry: 173 if (!bio) { 174 bio = bl_alloc_init_bio(npg, map->bdev, 175 disk_addr >> SECTOR_SHIFT, end_io, par); 176 if (!bio) 177 return ERR_PTR(-ENOMEM); 178 } 179 if (bio_add_page(bio, page, *len, offset) < *len) { 180 bio = bl_submit_bio(rw, bio); 181 goto retry; 182 } 183 return bio; 184 } 185 186 static void bl_end_io_read(struct bio *bio, int err) 187 { 188 struct parallel_io *par = bio->bi_private; 189 190 if (err) { 191 struct nfs_pgio_header *header = par->data; 192 193 if (!header->pnfs_error) 194 header->pnfs_error = -EIO; 195 pnfs_set_lo_fail(header->lseg); 196 } 197 198 bio_put(bio); 199 put_parallel(par); 200 } 201 202 static void bl_read_cleanup(struct work_struct *work) 203 { 204 struct rpc_task *task; 205 struct nfs_pgio_header *hdr; 206 dprintk("%s enter\n", __func__); 207 task = container_of(work, struct rpc_task, u.tk_work); 208 hdr = container_of(task, struct nfs_pgio_header, task); 209 pnfs_ld_read_done(hdr); 210 } 211 212 static void 213 bl_end_par_io_read(void *data) 214 { 215 struct nfs_pgio_header *hdr = data; 216 217 hdr->task.tk_status = hdr->pnfs_error; 218 INIT_WORK(&hdr->task.u.tk_work, bl_read_cleanup); 219 schedule_work(&hdr->task.u.tk_work); 220 } 221 222 static enum pnfs_try_status 223 bl_read_pagelist(struct nfs_pgio_header *header) 224 { 225 struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg); 226 struct pnfs_block_dev_map map = { .start = NFS4_MAX_UINT64 }; 227 struct bio *bio = NULL; 228 struct pnfs_block_extent be; 229 sector_t isect, extent_length = 0; 230 struct parallel_io *par; 231 loff_t f_offset = header->args.offset; 232 size_t bytes_left = header->args.count; 233 unsigned int pg_offset, pg_len; 234 struct page **pages = header->args.pages; 235 int pg_index = header->args.pgbase >> PAGE_CACHE_SHIFT; 236 const bool is_dio = (header->dreq != NULL); 237 struct blk_plug plug; 238 int i; 239 240 dprintk("%s enter nr_pages %u offset %lld count %u\n", __func__, 241 header->page_array.npages, f_offset, 242 (unsigned int)header->args.count); 243 244 par = alloc_parallel(header); 245 if (!par) 246 return PNFS_NOT_ATTEMPTED; 247 par->pnfs_callback = bl_end_par_io_read; 248 249 blk_start_plug(&plug); 250 251 isect = (sector_t) (f_offset >> SECTOR_SHIFT); 252 /* Code assumes extents are page-aligned */ 253 for (i = pg_index; i < header->page_array.npages; i++) { 254 if (extent_length <= 0) { 255 /* We've used up the previous extent */ 256 bio = bl_submit_bio(READ, bio); 257 258 /* Get the next one */ 259 if (!ext_tree_lookup(bl, isect, &be, false)) { 260 header->pnfs_error = -EIO; 261 goto out; 262 } 263 extent_length = be.be_length - (isect - be.be_f_offset); 264 } 265 266 pg_offset = f_offset & ~PAGE_CACHE_MASK; 267 if (is_dio) { 268 if (pg_offset + bytes_left > PAGE_CACHE_SIZE) 269 pg_len = PAGE_CACHE_SIZE - pg_offset; 270 else 271 pg_len = bytes_left; 272 } else { 273 BUG_ON(pg_offset != 0); 274 pg_len = PAGE_CACHE_SIZE; 275 } 276 277 isect += (pg_offset >> SECTOR_SHIFT); 278 extent_length -= (pg_offset >> SECTOR_SHIFT); 279 280 if (is_hole(&be)) { 281 bio = bl_submit_bio(READ, bio); 282 /* Fill hole w/ zeroes w/o accessing device */ 283 dprintk("%s Zeroing page for hole\n", __func__); 284 zero_user_segment(pages[i], pg_offset, pg_len); 285 286 /* invalidate map */ 287 map.start = NFS4_MAX_UINT64; 288 } else { 289 bio = do_add_page_to_bio(bio, 290 header->page_array.npages - i, 291 READ, 292 isect, pages[i], &map, &be, 293 bl_end_io_read, par, 294 pg_offset, &pg_len); 295 if (IS_ERR(bio)) { 296 header->pnfs_error = PTR_ERR(bio); 297 bio = NULL; 298 goto out; 299 } 300 } 301 isect += (pg_len >> SECTOR_SHIFT); 302 extent_length -= (pg_len >> SECTOR_SHIFT); 303 f_offset += pg_len; 304 bytes_left -= pg_len; 305 } 306 if ((isect << SECTOR_SHIFT) >= header->inode->i_size) { 307 header->res.eof = 1; 308 header->res.count = header->inode->i_size - header->args.offset; 309 } else { 310 header->res.count = (isect << SECTOR_SHIFT) - header->args.offset; 311 } 312 out: 313 bl_submit_bio(READ, bio); 314 blk_finish_plug(&plug); 315 put_parallel(par); 316 return PNFS_ATTEMPTED; 317 } 318 319 static void bl_end_io_write(struct bio *bio, int err) 320 { 321 struct parallel_io *par = bio->bi_private; 322 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 323 struct nfs_pgio_header *header = par->data; 324 325 if (!uptodate) { 326 if (!header->pnfs_error) 327 header->pnfs_error = -EIO; 328 pnfs_set_lo_fail(header->lseg); 329 } 330 bio_put(bio); 331 put_parallel(par); 332 } 333 334 /* Function scheduled for call during bl_end_par_io_write, 335 * it marks sectors as written and extends the commitlist. 336 */ 337 static void bl_write_cleanup(struct work_struct *work) 338 { 339 struct rpc_task *task = container_of(work, struct rpc_task, u.tk_work); 340 struct nfs_pgio_header *hdr = 341 container_of(task, struct nfs_pgio_header, task); 342 343 dprintk("%s enter\n", __func__); 344 345 if (likely(!hdr->pnfs_error)) { 346 struct pnfs_block_layout *bl = BLK_LSEG2EXT(hdr->lseg); 347 u64 start = hdr->args.offset & (loff_t)PAGE_CACHE_MASK; 348 u64 end = (hdr->args.offset + hdr->args.count + 349 PAGE_CACHE_SIZE - 1) & (loff_t)PAGE_CACHE_MASK; 350 351 ext_tree_mark_written(bl, start >> SECTOR_SHIFT, 352 (end - start) >> SECTOR_SHIFT); 353 } 354 355 pnfs_ld_write_done(hdr); 356 } 357 358 /* Called when last of bios associated with a bl_write_pagelist call finishes */ 359 static void bl_end_par_io_write(void *data) 360 { 361 struct nfs_pgio_header *hdr = data; 362 363 hdr->task.tk_status = hdr->pnfs_error; 364 hdr->verf.committed = NFS_FILE_SYNC; 365 INIT_WORK(&hdr->task.u.tk_work, bl_write_cleanup); 366 schedule_work(&hdr->task.u.tk_work); 367 } 368 369 static enum pnfs_try_status 370 bl_write_pagelist(struct nfs_pgio_header *header, int sync) 371 { 372 struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg); 373 struct pnfs_block_dev_map map = { .start = NFS4_MAX_UINT64 }; 374 struct bio *bio = NULL; 375 struct pnfs_block_extent be; 376 sector_t isect, extent_length = 0; 377 struct parallel_io *par = NULL; 378 loff_t offset = header->args.offset; 379 size_t count = header->args.count; 380 struct page **pages = header->args.pages; 381 int pg_index = header->args.pgbase >> PAGE_CACHE_SHIFT; 382 unsigned int pg_len; 383 struct blk_plug plug; 384 int i; 385 386 dprintk("%s enter, %Zu@%lld\n", __func__, count, offset); 387 388 /* At this point, header->page_aray is a (sequential) list of nfs_pages. 389 * We want to write each, and if there is an error set pnfs_error 390 * to have it redone using nfs. 391 */ 392 par = alloc_parallel(header); 393 if (!par) 394 return PNFS_NOT_ATTEMPTED; 395 par->pnfs_callback = bl_end_par_io_write; 396 397 blk_start_plug(&plug); 398 399 /* we always write out the whole page */ 400 offset = offset & (loff_t)PAGE_CACHE_MASK; 401 isect = offset >> SECTOR_SHIFT; 402 403 for (i = pg_index; i < header->page_array.npages; i++) { 404 if (extent_length <= 0) { 405 /* We've used up the previous extent */ 406 bio = bl_submit_bio(WRITE, bio); 407 /* Get the next one */ 408 if (!ext_tree_lookup(bl, isect, &be, true)) { 409 header->pnfs_error = -EINVAL; 410 goto out; 411 } 412 413 extent_length = be.be_length - (isect - be.be_f_offset); 414 } 415 416 pg_len = PAGE_CACHE_SIZE; 417 bio = do_add_page_to_bio(bio, header->page_array.npages - i, 418 WRITE, isect, pages[i], &map, &be, 419 bl_end_io_write, par, 420 0, &pg_len); 421 if (IS_ERR(bio)) { 422 header->pnfs_error = PTR_ERR(bio); 423 bio = NULL; 424 goto out; 425 } 426 427 offset += pg_len; 428 count -= pg_len; 429 isect += (pg_len >> SECTOR_SHIFT); 430 extent_length -= (pg_len >> SECTOR_SHIFT); 431 } 432 433 header->res.count = header->args.count; 434 out: 435 bl_submit_bio(WRITE, bio); 436 blk_finish_plug(&plug); 437 put_parallel(par); 438 return PNFS_ATTEMPTED; 439 } 440 441 static void bl_free_layout_hdr(struct pnfs_layout_hdr *lo) 442 { 443 struct pnfs_block_layout *bl = BLK_LO2EXT(lo); 444 int err; 445 446 dprintk("%s enter\n", __func__); 447 448 err = ext_tree_remove(bl, true, 0, LLONG_MAX); 449 WARN_ON(err); 450 451 kfree(bl); 452 } 453 454 static struct pnfs_layout_hdr *bl_alloc_layout_hdr(struct inode *inode, 455 gfp_t gfp_flags) 456 { 457 struct pnfs_block_layout *bl; 458 459 dprintk("%s enter\n", __func__); 460 bl = kzalloc(sizeof(*bl), gfp_flags); 461 if (!bl) 462 return NULL; 463 464 bl->bl_ext_rw = RB_ROOT; 465 bl->bl_ext_ro = RB_ROOT; 466 spin_lock_init(&bl->bl_ext_lock); 467 468 return &bl->bl_layout; 469 } 470 471 static void bl_free_lseg(struct pnfs_layout_segment *lseg) 472 { 473 dprintk("%s enter\n", __func__); 474 kfree(lseg); 475 } 476 477 /* Tracks info needed to ensure extents in layout obey constraints of spec */ 478 struct layout_verification { 479 u32 mode; /* R or RW */ 480 u64 start; /* Expected start of next non-COW extent */ 481 u64 inval; /* Start of INVAL coverage */ 482 u64 cowread; /* End of COW read coverage */ 483 }; 484 485 /* Verify the extent meets the layout requirements of the pnfs-block draft, 486 * section 2.3.1. 487 */ 488 static int verify_extent(struct pnfs_block_extent *be, 489 struct layout_verification *lv) 490 { 491 if (lv->mode == IOMODE_READ) { 492 if (be->be_state == PNFS_BLOCK_READWRITE_DATA || 493 be->be_state == PNFS_BLOCK_INVALID_DATA) 494 return -EIO; 495 if (be->be_f_offset != lv->start) 496 return -EIO; 497 lv->start += be->be_length; 498 return 0; 499 } 500 /* lv->mode == IOMODE_RW */ 501 if (be->be_state == PNFS_BLOCK_READWRITE_DATA) { 502 if (be->be_f_offset != lv->start) 503 return -EIO; 504 if (lv->cowread > lv->start) 505 return -EIO; 506 lv->start += be->be_length; 507 lv->inval = lv->start; 508 return 0; 509 } else if (be->be_state == PNFS_BLOCK_INVALID_DATA) { 510 if (be->be_f_offset != lv->start) 511 return -EIO; 512 lv->start += be->be_length; 513 return 0; 514 } else if (be->be_state == PNFS_BLOCK_READ_DATA) { 515 if (be->be_f_offset > lv->start) 516 return -EIO; 517 if (be->be_f_offset < lv->inval) 518 return -EIO; 519 if (be->be_f_offset < lv->cowread) 520 return -EIO; 521 /* It looks like you might want to min this with lv->start, 522 * but you really don't. 523 */ 524 lv->inval = lv->inval + be->be_length; 525 lv->cowread = be->be_f_offset + be->be_length; 526 return 0; 527 } else 528 return -EIO; 529 } 530 531 static int decode_sector_number(__be32 **rp, sector_t *sp) 532 { 533 uint64_t s; 534 535 *rp = xdr_decode_hyper(*rp, &s); 536 if (s & 0x1ff) { 537 printk(KERN_WARNING "NFS: %s: sector not aligned\n", __func__); 538 return -1; 539 } 540 *sp = s >> SECTOR_SHIFT; 541 return 0; 542 } 543 544 static int 545 bl_alloc_extent(struct xdr_stream *xdr, struct pnfs_layout_hdr *lo, 546 struct layout_verification *lv, struct list_head *extents, 547 gfp_t gfp_mask) 548 { 549 struct pnfs_block_extent *be; 550 struct nfs4_deviceid id; 551 int error; 552 __be32 *p; 553 554 p = xdr_inline_decode(xdr, 28 + NFS4_DEVICEID4_SIZE); 555 if (!p) 556 return -EIO; 557 558 be = kzalloc(sizeof(*be), GFP_NOFS); 559 if (!be) 560 return -ENOMEM; 561 562 memcpy(&id, p, NFS4_DEVICEID4_SIZE); 563 p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE); 564 565 error = -EIO; 566 be->be_device = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode), &id, 567 lo->plh_lc_cred, gfp_mask); 568 if (!be->be_device) 569 goto out_free_be; 570 571 /* 572 * The next three values are read in as bytes, but stored in the 573 * extent structure in 512-byte granularity. 574 */ 575 if (decode_sector_number(&p, &be->be_f_offset) < 0) 576 goto out_put_deviceid; 577 if (decode_sector_number(&p, &be->be_length) < 0) 578 goto out_put_deviceid; 579 if (decode_sector_number(&p, &be->be_v_offset) < 0) 580 goto out_put_deviceid; 581 be->be_state = be32_to_cpup(p++); 582 583 error = verify_extent(be, lv); 584 if (error) { 585 dprintk("%s: extent verification failed\n", __func__); 586 goto out_put_deviceid; 587 } 588 589 list_add_tail(&be->be_list, extents); 590 return 0; 591 592 out_put_deviceid: 593 nfs4_put_deviceid_node(be->be_device); 594 out_free_be: 595 kfree(be); 596 return error; 597 } 598 599 static struct pnfs_layout_segment * 600 bl_alloc_lseg(struct pnfs_layout_hdr *lo, struct nfs4_layoutget_res *lgr, 601 gfp_t gfp_mask) 602 { 603 struct layout_verification lv = { 604 .mode = lgr->range.iomode, 605 .start = lgr->range.offset >> SECTOR_SHIFT, 606 .inval = lgr->range.offset >> SECTOR_SHIFT, 607 .cowread = lgr->range.offset >> SECTOR_SHIFT, 608 }; 609 struct pnfs_block_layout *bl = BLK_LO2EXT(lo); 610 struct pnfs_layout_segment *lseg; 611 struct xdr_buf buf; 612 struct xdr_stream xdr; 613 struct page *scratch; 614 int status, i; 615 uint32_t count; 616 __be32 *p; 617 LIST_HEAD(extents); 618 619 dprintk("---> %s\n", __func__); 620 621 lseg = kzalloc(sizeof(*lseg), gfp_mask); 622 if (!lseg) 623 return ERR_PTR(-ENOMEM); 624 625 status = -ENOMEM; 626 scratch = alloc_page(gfp_mask); 627 if (!scratch) 628 goto out; 629 630 xdr_init_decode_pages(&xdr, &buf, 631 lgr->layoutp->pages, lgr->layoutp->len); 632 xdr_set_scratch_buffer(&xdr, page_address(scratch), PAGE_SIZE); 633 634 status = -EIO; 635 p = xdr_inline_decode(&xdr, 4); 636 if (unlikely(!p)) 637 goto out_free_scratch; 638 639 count = be32_to_cpup(p++); 640 dprintk("%s: number of extents %d\n", __func__, count); 641 642 /* 643 * Decode individual extents, putting them in temporary staging area 644 * until whole layout is decoded to make error recovery easier. 645 */ 646 for (i = 0; i < count; i++) { 647 status = bl_alloc_extent(&xdr, lo, &lv, &extents, gfp_mask); 648 if (status) 649 goto process_extents; 650 } 651 652 if (lgr->range.offset + lgr->range.length != 653 lv.start << SECTOR_SHIFT) { 654 dprintk("%s Final length mismatch\n", __func__); 655 status = -EIO; 656 goto process_extents; 657 } 658 659 if (lv.start < lv.cowread) { 660 dprintk("%s Final uncovered COW extent\n", __func__); 661 status = -EIO; 662 } 663 664 process_extents: 665 while (!list_empty(&extents)) { 666 struct pnfs_block_extent *be = 667 list_first_entry(&extents, struct pnfs_block_extent, 668 be_list); 669 list_del(&be->be_list); 670 671 if (!status) 672 status = ext_tree_insert(bl, be); 673 674 if (status) { 675 nfs4_put_deviceid_node(be->be_device); 676 kfree(be); 677 } 678 } 679 680 out_free_scratch: 681 __free_page(scratch); 682 out: 683 dprintk("%s returns %d\n", __func__, status); 684 if (status) { 685 kfree(lseg); 686 return ERR_PTR(status); 687 } 688 return lseg; 689 } 690 691 static void 692 bl_return_range(struct pnfs_layout_hdr *lo, 693 struct pnfs_layout_range *range) 694 { 695 struct pnfs_block_layout *bl = BLK_LO2EXT(lo); 696 sector_t offset = range->offset >> SECTOR_SHIFT, end; 697 698 if (range->offset % 8) { 699 dprintk("%s: offset %lld not block size aligned\n", 700 __func__, range->offset); 701 return; 702 } 703 704 if (range->length != NFS4_MAX_UINT64) { 705 if (range->length % 8) { 706 dprintk("%s: length %lld not block size aligned\n", 707 __func__, range->length); 708 return; 709 } 710 711 end = offset + (range->length >> SECTOR_SHIFT); 712 } else { 713 end = round_down(NFS4_MAX_UINT64, PAGE_SIZE); 714 } 715 716 ext_tree_remove(bl, range->iomode & IOMODE_RW, offset, end); 717 } 718 719 static int 720 bl_prepare_layoutcommit(struct nfs4_layoutcommit_args *arg) 721 { 722 return ext_tree_prepare_commit(arg); 723 } 724 725 static void 726 bl_cleanup_layoutcommit(struct nfs4_layoutcommit_data *lcdata) 727 { 728 ext_tree_mark_committed(&lcdata->args, lcdata->res.status); 729 } 730 731 static int 732 bl_set_layoutdriver(struct nfs_server *server, const struct nfs_fh *fh) 733 { 734 dprintk("%s enter\n", __func__); 735 736 if (server->pnfs_blksize == 0) { 737 dprintk("%s Server did not return blksize\n", __func__); 738 return -EINVAL; 739 } 740 if (server->pnfs_blksize > PAGE_SIZE) { 741 printk(KERN_ERR "%s: pNFS blksize %d not supported.\n", 742 __func__, server->pnfs_blksize); 743 return -EINVAL; 744 } 745 746 return 0; 747 } 748 749 static bool 750 is_aligned_req(struct nfs_pageio_descriptor *pgio, 751 struct nfs_page *req, unsigned int alignment) 752 { 753 /* 754 * Always accept buffered writes, higher layers take care of the 755 * right alignment. 756 */ 757 if (pgio->pg_dreq == NULL) 758 return true; 759 760 if (!IS_ALIGNED(req->wb_offset, alignment)) 761 return false; 762 763 if (IS_ALIGNED(req->wb_bytes, alignment)) 764 return true; 765 766 if (req_offset(req) + req->wb_bytes == i_size_read(pgio->pg_inode)) { 767 /* 768 * If the write goes up to the inode size, just write 769 * the full page. Data past the inode size is 770 * guaranteed to be zeroed by the higher level client 771 * code, and this behaviour is mandated by RFC 5663 772 * section 2.3.2. 773 */ 774 return true; 775 } 776 777 return false; 778 } 779 780 static void 781 bl_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req) 782 { 783 if (!is_aligned_req(pgio, req, SECTOR_SIZE)) { 784 nfs_pageio_reset_read_mds(pgio); 785 return; 786 } 787 788 pnfs_generic_pg_init_read(pgio, req); 789 } 790 791 /* 792 * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number 793 * of bytes (maximum @req->wb_bytes) that can be coalesced. 794 */ 795 static size_t 796 bl_pg_test_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, 797 struct nfs_page *req) 798 { 799 if (!is_aligned_req(pgio, req, SECTOR_SIZE)) 800 return 0; 801 return pnfs_generic_pg_test(pgio, prev, req); 802 } 803 804 /* 805 * Return the number of contiguous bytes for a given inode 806 * starting at page frame idx. 807 */ 808 static u64 pnfs_num_cont_bytes(struct inode *inode, pgoff_t idx) 809 { 810 struct address_space *mapping = inode->i_mapping; 811 pgoff_t end; 812 813 /* Optimize common case that writes from 0 to end of file */ 814 end = DIV_ROUND_UP(i_size_read(inode), PAGE_CACHE_SIZE); 815 if (end != inode->i_mapping->nrpages) { 816 rcu_read_lock(); 817 end = page_cache_next_hole(mapping, idx + 1, ULONG_MAX); 818 rcu_read_unlock(); 819 } 820 821 if (!end) 822 return i_size_read(inode) - (idx << PAGE_CACHE_SHIFT); 823 else 824 return (end - idx) << PAGE_CACHE_SHIFT; 825 } 826 827 static void 828 bl_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req) 829 { 830 u64 wb_size; 831 832 if (!is_aligned_req(pgio, req, PAGE_SIZE)) { 833 nfs_pageio_reset_write_mds(pgio); 834 return; 835 } 836 837 if (pgio->pg_dreq == NULL) 838 wb_size = pnfs_num_cont_bytes(pgio->pg_inode, 839 req->wb_index); 840 else 841 wb_size = nfs_dreq_bytes_left(pgio->pg_dreq); 842 843 pnfs_generic_pg_init_write(pgio, req, wb_size); 844 } 845 846 /* 847 * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number 848 * of bytes (maximum @req->wb_bytes) that can be coalesced. 849 */ 850 static size_t 851 bl_pg_test_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, 852 struct nfs_page *req) 853 { 854 if (!is_aligned_req(pgio, req, PAGE_SIZE)) 855 return 0; 856 return pnfs_generic_pg_test(pgio, prev, req); 857 } 858 859 static const struct nfs_pageio_ops bl_pg_read_ops = { 860 .pg_init = bl_pg_init_read, 861 .pg_test = bl_pg_test_read, 862 .pg_doio = pnfs_generic_pg_readpages, 863 }; 864 865 static const struct nfs_pageio_ops bl_pg_write_ops = { 866 .pg_init = bl_pg_init_write, 867 .pg_test = bl_pg_test_write, 868 .pg_doio = pnfs_generic_pg_writepages, 869 }; 870 871 static struct pnfs_layoutdriver_type blocklayout_type = { 872 .id = LAYOUT_BLOCK_VOLUME, 873 .name = "LAYOUT_BLOCK_VOLUME", 874 .owner = THIS_MODULE, 875 .flags = PNFS_LAYOUTRET_ON_SETATTR | 876 PNFS_READ_WHOLE_PAGE, 877 .read_pagelist = bl_read_pagelist, 878 .write_pagelist = bl_write_pagelist, 879 .alloc_layout_hdr = bl_alloc_layout_hdr, 880 .free_layout_hdr = bl_free_layout_hdr, 881 .alloc_lseg = bl_alloc_lseg, 882 .free_lseg = bl_free_lseg, 883 .return_range = bl_return_range, 884 .prepare_layoutcommit = bl_prepare_layoutcommit, 885 .cleanup_layoutcommit = bl_cleanup_layoutcommit, 886 .set_layoutdriver = bl_set_layoutdriver, 887 .alloc_deviceid_node = bl_alloc_deviceid_node, 888 .free_deviceid_node = bl_free_deviceid_node, 889 .pg_read_ops = &bl_pg_read_ops, 890 .pg_write_ops = &bl_pg_write_ops, 891 }; 892 893 static int __init nfs4blocklayout_init(void) 894 { 895 int ret; 896 897 dprintk("%s: NFSv4 Block Layout Driver Registering...\n", __func__); 898 899 ret = pnfs_register_layoutdriver(&blocklayout_type); 900 if (ret) 901 goto out; 902 ret = bl_init_pipefs(); 903 if (ret) 904 goto out_unregister; 905 return 0; 906 907 out_unregister: 908 pnfs_unregister_layoutdriver(&blocklayout_type); 909 out: 910 return ret; 911 } 912 913 static void __exit nfs4blocklayout_exit(void) 914 { 915 dprintk("%s: NFSv4 Block Layout Driver Unregistering...\n", 916 __func__); 917 918 bl_cleanup_pipefs(); 919 pnfs_unregister_layoutdriver(&blocklayout_type); 920 } 921 922 MODULE_ALIAS("nfs-layouttype4-3"); 923 924 module_init(nfs4blocklayout_init); 925 module_exit(nfs4blocklayout_exit); 926