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(struct bio *bio) 106 { 107 if (bio) { 108 get_parallel(bio->bi_private); 109 dprintk("%s submitting %s bio %u@%llu\n", __func__, 110 bio_op(bio) == READ ? "read" : "write", 111 bio->bi_iter.bi_size, 112 (unsigned long long)bio->bi_iter.bi_sector); 113 submit_bio(bio); 114 } 115 return NULL; 116 } 117 118 static struct bio * 119 bl_alloc_init_bio(int npg, struct block_device *bdev, sector_t disk_sector, 120 bio_end_io_t end_io, struct parallel_io *par) 121 { 122 struct bio *bio; 123 124 npg = min(npg, BIO_MAX_PAGES); 125 bio = bio_alloc(GFP_NOIO, npg); 126 if (!bio && (current->flags & PF_MEMALLOC)) { 127 while (!bio && (npg /= 2)) 128 bio = bio_alloc(GFP_NOIO, npg); 129 } 130 131 if (bio) { 132 bio->bi_iter.bi_sector = disk_sector; 133 bio->bi_bdev = bdev; 134 bio->bi_end_io = end_io; 135 bio->bi_private = par; 136 } 137 return bio; 138 } 139 140 static struct bio * 141 do_add_page_to_bio(struct bio *bio, int npg, int rw, sector_t isect, 142 struct page *page, struct pnfs_block_dev_map *map, 143 struct pnfs_block_extent *be, bio_end_io_t end_io, 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(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 bio_set_op_attrs(bio, rw, 0); 179 } 180 if (bio_add_page(bio, page, *len, offset) < *len) { 181 bio = bl_submit_bio(bio); 182 goto retry; 183 } 184 return bio; 185 } 186 187 static void bl_end_io_read(struct bio *bio) 188 { 189 struct parallel_io *par = bio->bi_private; 190 191 if (bio->bi_error) { 192 struct nfs_pgio_header *header = par->data; 193 194 if (!header->pnfs_error) 195 header->pnfs_error = -EIO; 196 pnfs_set_lo_fail(header->lseg); 197 } 198 199 bio_put(bio); 200 put_parallel(par); 201 } 202 203 static void bl_read_cleanup(struct work_struct *work) 204 { 205 struct rpc_task *task; 206 struct nfs_pgio_header *hdr; 207 dprintk("%s enter\n", __func__); 208 task = container_of(work, struct rpc_task, u.tk_work); 209 hdr = container_of(task, struct nfs_pgio_header, task); 210 pnfs_ld_read_done(hdr); 211 } 212 213 static void 214 bl_end_par_io_read(void *data) 215 { 216 struct nfs_pgio_header *hdr = data; 217 218 hdr->task.tk_status = hdr->pnfs_error; 219 INIT_WORK(&hdr->task.u.tk_work, bl_read_cleanup); 220 schedule_work(&hdr->task.u.tk_work); 221 } 222 223 static enum pnfs_try_status 224 bl_read_pagelist(struct nfs_pgio_header *header) 225 { 226 struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg); 227 struct pnfs_block_dev_map map = { .start = NFS4_MAX_UINT64 }; 228 struct bio *bio = NULL; 229 struct pnfs_block_extent be; 230 sector_t isect, extent_length = 0; 231 struct parallel_io *par; 232 loff_t f_offset = header->args.offset; 233 size_t bytes_left = header->args.count; 234 unsigned int pg_offset = header->args.pgbase, pg_len; 235 struct page **pages = header->args.pages; 236 int pg_index = header->args.pgbase >> PAGE_SHIFT; 237 const bool is_dio = (header->dreq != NULL); 238 struct blk_plug plug; 239 int i; 240 241 dprintk("%s enter nr_pages %u offset %lld count %u\n", __func__, 242 header->page_array.npages, f_offset, 243 (unsigned int)header->args.count); 244 245 par = alloc_parallel(header); 246 if (!par) 247 return PNFS_NOT_ATTEMPTED; 248 par->pnfs_callback = bl_end_par_io_read; 249 250 blk_start_plug(&plug); 251 252 isect = (sector_t) (f_offset >> SECTOR_SHIFT); 253 /* Code assumes extents are page-aligned */ 254 for (i = pg_index; i < header->page_array.npages; i++) { 255 if (extent_length <= 0) { 256 /* We've used up the previous extent */ 257 bio = bl_submit_bio(bio); 258 259 /* Get the next one */ 260 if (!ext_tree_lookup(bl, isect, &be, false)) { 261 header->pnfs_error = -EIO; 262 goto out; 263 } 264 extent_length = be.be_length - (isect - be.be_f_offset); 265 } 266 267 if (is_dio) { 268 if (pg_offset + bytes_left > PAGE_SIZE) 269 pg_len = PAGE_SIZE - pg_offset; 270 else 271 pg_len = bytes_left; 272 } else { 273 BUG_ON(pg_offset != 0); 274 pg_len = PAGE_SIZE; 275 } 276 277 if (is_hole(&be)) { 278 bio = bl_submit_bio(bio); 279 /* Fill hole w/ zeroes w/o accessing device */ 280 dprintk("%s Zeroing page for hole\n", __func__); 281 zero_user_segment(pages[i], pg_offset, pg_len); 282 283 /* invalidate map */ 284 map.start = NFS4_MAX_UINT64; 285 } else { 286 bio = do_add_page_to_bio(bio, 287 header->page_array.npages - i, 288 READ, 289 isect, pages[i], &map, &be, 290 bl_end_io_read, par, 291 pg_offset, &pg_len); 292 if (IS_ERR(bio)) { 293 header->pnfs_error = PTR_ERR(bio); 294 bio = NULL; 295 goto out; 296 } 297 } 298 isect += (pg_len >> SECTOR_SHIFT); 299 extent_length -= (pg_len >> SECTOR_SHIFT); 300 f_offset += pg_len; 301 bytes_left -= pg_len; 302 pg_offset = 0; 303 } 304 if ((isect << SECTOR_SHIFT) >= header->inode->i_size) { 305 header->res.eof = 1; 306 header->res.count = header->inode->i_size - header->args.offset; 307 } else { 308 header->res.count = (isect << SECTOR_SHIFT) - header->args.offset; 309 } 310 out: 311 bl_submit_bio(bio); 312 blk_finish_plug(&plug); 313 put_parallel(par); 314 return PNFS_ATTEMPTED; 315 } 316 317 static void bl_end_io_write(struct bio *bio) 318 { 319 struct parallel_io *par = bio->bi_private; 320 struct nfs_pgio_header *header = par->data; 321 322 if (bio->bi_error) { 323 if (!header->pnfs_error) 324 header->pnfs_error = -EIO; 325 pnfs_set_lo_fail(header->lseg); 326 } 327 bio_put(bio); 328 put_parallel(par); 329 } 330 331 /* Function scheduled for call during bl_end_par_io_write, 332 * it marks sectors as written and extends the commitlist. 333 */ 334 static void bl_write_cleanup(struct work_struct *work) 335 { 336 struct rpc_task *task = container_of(work, struct rpc_task, u.tk_work); 337 struct nfs_pgio_header *hdr = 338 container_of(task, struct nfs_pgio_header, task); 339 340 dprintk("%s enter\n", __func__); 341 342 if (likely(!hdr->pnfs_error)) { 343 struct pnfs_block_layout *bl = BLK_LSEG2EXT(hdr->lseg); 344 u64 start = hdr->args.offset & (loff_t)PAGE_MASK; 345 u64 end = (hdr->args.offset + hdr->args.count + 346 PAGE_SIZE - 1) & (loff_t)PAGE_MASK; 347 u64 lwb = hdr->args.offset + hdr->args.count; 348 349 ext_tree_mark_written(bl, start >> SECTOR_SHIFT, 350 (end - start) >> SECTOR_SHIFT, lwb); 351 } 352 353 pnfs_ld_write_done(hdr); 354 } 355 356 /* Called when last of bios associated with a bl_write_pagelist call finishes */ 357 static void bl_end_par_io_write(void *data) 358 { 359 struct nfs_pgio_header *hdr = data; 360 361 hdr->task.tk_status = hdr->pnfs_error; 362 hdr->verf.committed = NFS_FILE_SYNC; 363 INIT_WORK(&hdr->task.u.tk_work, bl_write_cleanup); 364 schedule_work(&hdr->task.u.tk_work); 365 } 366 367 static enum pnfs_try_status 368 bl_write_pagelist(struct nfs_pgio_header *header, int sync) 369 { 370 struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg); 371 struct pnfs_block_dev_map map = { .start = NFS4_MAX_UINT64 }; 372 struct bio *bio = NULL; 373 struct pnfs_block_extent be; 374 sector_t isect, extent_length = 0; 375 struct parallel_io *par = NULL; 376 loff_t offset = header->args.offset; 377 size_t count = header->args.count; 378 struct page **pages = header->args.pages; 379 int pg_index = header->args.pgbase >> PAGE_SHIFT; 380 unsigned int pg_len; 381 struct blk_plug plug; 382 int i; 383 384 dprintk("%s enter, %zu@%lld\n", __func__, count, offset); 385 386 /* At this point, header->page_aray is a (sequential) list of nfs_pages. 387 * We want to write each, and if there is an error set pnfs_error 388 * to have it redone using nfs. 389 */ 390 par = alloc_parallel(header); 391 if (!par) 392 return PNFS_NOT_ATTEMPTED; 393 par->pnfs_callback = bl_end_par_io_write; 394 395 blk_start_plug(&plug); 396 397 /* we always write out the whole page */ 398 offset = offset & (loff_t)PAGE_MASK; 399 isect = offset >> SECTOR_SHIFT; 400 401 for (i = pg_index; i < header->page_array.npages; i++) { 402 if (extent_length <= 0) { 403 /* We've used up the previous extent */ 404 bio = bl_submit_bio(bio); 405 /* Get the next one */ 406 if (!ext_tree_lookup(bl, isect, &be, true)) { 407 header->pnfs_error = -EINVAL; 408 goto out; 409 } 410 411 extent_length = be.be_length - (isect - be.be_f_offset); 412 } 413 414 pg_len = PAGE_SIZE; 415 bio = do_add_page_to_bio(bio, header->page_array.npages - i, 416 WRITE, isect, pages[i], &map, &be, 417 bl_end_io_write, par, 418 0, &pg_len); 419 if (IS_ERR(bio)) { 420 header->pnfs_error = PTR_ERR(bio); 421 bio = NULL; 422 goto out; 423 } 424 425 offset += pg_len; 426 count -= pg_len; 427 isect += (pg_len >> SECTOR_SHIFT); 428 extent_length -= (pg_len >> SECTOR_SHIFT); 429 } 430 431 header->res.count = header->args.count; 432 out: 433 bl_submit_bio(bio); 434 blk_finish_plug(&plug); 435 put_parallel(par); 436 return PNFS_ATTEMPTED; 437 } 438 439 static void bl_free_layout_hdr(struct pnfs_layout_hdr *lo) 440 { 441 struct pnfs_block_layout *bl = BLK_LO2EXT(lo); 442 int err; 443 444 dprintk("%s enter\n", __func__); 445 446 err = ext_tree_remove(bl, true, 0, LLONG_MAX); 447 WARN_ON(err); 448 449 kfree(bl); 450 } 451 452 static struct pnfs_layout_hdr *__bl_alloc_layout_hdr(struct inode *inode, 453 gfp_t gfp_flags, bool is_scsi_layout) 454 { 455 struct pnfs_block_layout *bl; 456 457 dprintk("%s enter\n", __func__); 458 bl = kzalloc(sizeof(*bl), gfp_flags); 459 if (!bl) 460 return NULL; 461 462 bl->bl_ext_rw = RB_ROOT; 463 bl->bl_ext_ro = RB_ROOT; 464 spin_lock_init(&bl->bl_ext_lock); 465 466 bl->bl_scsi_layout = is_scsi_layout; 467 return &bl->bl_layout; 468 } 469 470 static struct pnfs_layout_hdr *bl_alloc_layout_hdr(struct inode *inode, 471 gfp_t gfp_flags) 472 { 473 return __bl_alloc_layout_hdr(inode, gfp_flags, false); 474 } 475 476 static struct pnfs_layout_hdr *sl_alloc_layout_hdr(struct inode *inode, 477 gfp_t gfp_flags) 478 { 479 return __bl_alloc_layout_hdr(inode, gfp_flags, true); 480 } 481 482 static void bl_free_lseg(struct pnfs_layout_segment *lseg) 483 { 484 dprintk("%s enter\n", __func__); 485 kfree(lseg); 486 } 487 488 /* Tracks info needed to ensure extents in layout obey constraints of spec */ 489 struct layout_verification { 490 u32 mode; /* R or RW */ 491 u64 start; /* Expected start of next non-COW extent */ 492 u64 inval; /* Start of INVAL coverage */ 493 u64 cowread; /* End of COW read coverage */ 494 }; 495 496 /* Verify the extent meets the layout requirements of the pnfs-block draft, 497 * section 2.3.1. 498 */ 499 static int verify_extent(struct pnfs_block_extent *be, 500 struct layout_verification *lv) 501 { 502 if (lv->mode == IOMODE_READ) { 503 if (be->be_state == PNFS_BLOCK_READWRITE_DATA || 504 be->be_state == PNFS_BLOCK_INVALID_DATA) 505 return -EIO; 506 if (be->be_f_offset != lv->start) 507 return -EIO; 508 lv->start += be->be_length; 509 return 0; 510 } 511 /* lv->mode == IOMODE_RW */ 512 if (be->be_state == PNFS_BLOCK_READWRITE_DATA) { 513 if (be->be_f_offset != lv->start) 514 return -EIO; 515 if (lv->cowread > lv->start) 516 return -EIO; 517 lv->start += be->be_length; 518 lv->inval = lv->start; 519 return 0; 520 } else if (be->be_state == PNFS_BLOCK_INVALID_DATA) { 521 if (be->be_f_offset != lv->start) 522 return -EIO; 523 lv->start += be->be_length; 524 return 0; 525 } else if (be->be_state == PNFS_BLOCK_READ_DATA) { 526 if (be->be_f_offset > lv->start) 527 return -EIO; 528 if (be->be_f_offset < lv->inval) 529 return -EIO; 530 if (be->be_f_offset < lv->cowread) 531 return -EIO; 532 /* It looks like you might want to min this with lv->start, 533 * but you really don't. 534 */ 535 lv->inval = lv->inval + be->be_length; 536 lv->cowread = be->be_f_offset + be->be_length; 537 return 0; 538 } else 539 return -EIO; 540 } 541 542 static int decode_sector_number(__be32 **rp, sector_t *sp) 543 { 544 uint64_t s; 545 546 *rp = xdr_decode_hyper(*rp, &s); 547 if (s & 0x1ff) { 548 printk(KERN_WARNING "NFS: %s: sector not aligned\n", __func__); 549 return -1; 550 } 551 *sp = s >> SECTOR_SHIFT; 552 return 0; 553 } 554 555 static int 556 bl_alloc_extent(struct xdr_stream *xdr, struct pnfs_layout_hdr *lo, 557 struct layout_verification *lv, struct list_head *extents, 558 gfp_t gfp_mask) 559 { 560 struct pnfs_block_extent *be; 561 struct nfs4_deviceid id; 562 int error; 563 __be32 *p; 564 565 p = xdr_inline_decode(xdr, 28 + NFS4_DEVICEID4_SIZE); 566 if (!p) 567 return -EIO; 568 569 be = kzalloc(sizeof(*be), GFP_NOFS); 570 if (!be) 571 return -ENOMEM; 572 573 memcpy(&id, p, NFS4_DEVICEID4_SIZE); 574 p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE); 575 576 error = -EIO; 577 be->be_device = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode), &id, 578 lo->plh_lc_cred, gfp_mask); 579 if (!be->be_device) 580 goto out_free_be; 581 582 /* 583 * The next three values are read in as bytes, but stored in the 584 * extent structure in 512-byte granularity. 585 */ 586 if (decode_sector_number(&p, &be->be_f_offset) < 0) 587 goto out_put_deviceid; 588 if (decode_sector_number(&p, &be->be_length) < 0) 589 goto out_put_deviceid; 590 if (decode_sector_number(&p, &be->be_v_offset) < 0) 591 goto out_put_deviceid; 592 be->be_state = be32_to_cpup(p++); 593 594 error = verify_extent(be, lv); 595 if (error) { 596 dprintk("%s: extent verification failed\n", __func__); 597 goto out_put_deviceid; 598 } 599 600 list_add_tail(&be->be_list, extents); 601 return 0; 602 603 out_put_deviceid: 604 nfs4_put_deviceid_node(be->be_device); 605 out_free_be: 606 kfree(be); 607 return error; 608 } 609 610 static struct pnfs_layout_segment * 611 bl_alloc_lseg(struct pnfs_layout_hdr *lo, struct nfs4_layoutget_res *lgr, 612 gfp_t gfp_mask) 613 { 614 struct layout_verification lv = { 615 .mode = lgr->range.iomode, 616 .start = lgr->range.offset >> SECTOR_SHIFT, 617 .inval = lgr->range.offset >> SECTOR_SHIFT, 618 .cowread = lgr->range.offset >> SECTOR_SHIFT, 619 }; 620 struct pnfs_block_layout *bl = BLK_LO2EXT(lo); 621 struct pnfs_layout_segment *lseg; 622 struct xdr_buf buf; 623 struct xdr_stream xdr; 624 struct page *scratch; 625 int status, i; 626 uint32_t count; 627 __be32 *p; 628 LIST_HEAD(extents); 629 630 dprintk("---> %s\n", __func__); 631 632 lseg = kzalloc(sizeof(*lseg), gfp_mask); 633 if (!lseg) 634 return ERR_PTR(-ENOMEM); 635 636 status = -ENOMEM; 637 scratch = alloc_page(gfp_mask); 638 if (!scratch) 639 goto out; 640 641 xdr_init_decode_pages(&xdr, &buf, 642 lgr->layoutp->pages, lgr->layoutp->len); 643 xdr_set_scratch_buffer(&xdr, page_address(scratch), PAGE_SIZE); 644 645 status = -EIO; 646 p = xdr_inline_decode(&xdr, 4); 647 if (unlikely(!p)) 648 goto out_free_scratch; 649 650 count = be32_to_cpup(p++); 651 dprintk("%s: number of extents %d\n", __func__, count); 652 653 /* 654 * Decode individual extents, putting them in temporary staging area 655 * until whole layout is decoded to make error recovery easier. 656 */ 657 for (i = 0; i < count; i++) { 658 status = bl_alloc_extent(&xdr, lo, &lv, &extents, gfp_mask); 659 if (status) 660 goto process_extents; 661 } 662 663 if (lgr->range.offset + lgr->range.length != 664 lv.start << SECTOR_SHIFT) { 665 dprintk("%s Final length mismatch\n", __func__); 666 status = -EIO; 667 goto process_extents; 668 } 669 670 if (lv.start < lv.cowread) { 671 dprintk("%s Final uncovered COW extent\n", __func__); 672 status = -EIO; 673 } 674 675 process_extents: 676 while (!list_empty(&extents)) { 677 struct pnfs_block_extent *be = 678 list_first_entry(&extents, struct pnfs_block_extent, 679 be_list); 680 list_del(&be->be_list); 681 682 if (!status) 683 status = ext_tree_insert(bl, be); 684 685 if (status) { 686 nfs4_put_deviceid_node(be->be_device); 687 kfree(be); 688 } 689 } 690 691 out_free_scratch: 692 __free_page(scratch); 693 out: 694 dprintk("%s returns %d\n", __func__, status); 695 if (status) { 696 kfree(lseg); 697 return ERR_PTR(status); 698 } 699 return lseg; 700 } 701 702 static void 703 bl_return_range(struct pnfs_layout_hdr *lo, 704 struct pnfs_layout_range *range) 705 { 706 struct pnfs_block_layout *bl = BLK_LO2EXT(lo); 707 sector_t offset = range->offset >> SECTOR_SHIFT, end; 708 709 if (range->offset % 8) { 710 dprintk("%s: offset %lld not block size aligned\n", 711 __func__, range->offset); 712 return; 713 } 714 715 if (range->length != NFS4_MAX_UINT64) { 716 if (range->length % 8) { 717 dprintk("%s: length %lld not block size aligned\n", 718 __func__, range->length); 719 return; 720 } 721 722 end = offset + (range->length >> SECTOR_SHIFT); 723 } else { 724 end = round_down(NFS4_MAX_UINT64, PAGE_SIZE); 725 } 726 727 ext_tree_remove(bl, range->iomode & IOMODE_RW, offset, end); 728 } 729 730 static int 731 bl_prepare_layoutcommit(struct nfs4_layoutcommit_args *arg) 732 { 733 return ext_tree_prepare_commit(arg); 734 } 735 736 static void 737 bl_cleanup_layoutcommit(struct nfs4_layoutcommit_data *lcdata) 738 { 739 ext_tree_mark_committed(&lcdata->args, lcdata->res.status); 740 } 741 742 static int 743 bl_set_layoutdriver(struct nfs_server *server, const struct nfs_fh *fh) 744 { 745 dprintk("%s enter\n", __func__); 746 747 if (server->pnfs_blksize == 0) { 748 dprintk("%s Server did not return blksize\n", __func__); 749 return -EINVAL; 750 } 751 if (server->pnfs_blksize > PAGE_SIZE) { 752 printk(KERN_ERR "%s: pNFS blksize %d not supported.\n", 753 __func__, server->pnfs_blksize); 754 return -EINVAL; 755 } 756 757 return 0; 758 } 759 760 static bool 761 is_aligned_req(struct nfs_pageio_descriptor *pgio, 762 struct nfs_page *req, unsigned int alignment, bool is_write) 763 { 764 /* 765 * Always accept buffered writes, higher layers take care of the 766 * right alignment. 767 */ 768 if (pgio->pg_dreq == NULL) 769 return true; 770 771 if (!IS_ALIGNED(req->wb_offset, alignment)) 772 return false; 773 774 if (IS_ALIGNED(req->wb_bytes, alignment)) 775 return true; 776 777 if (is_write && 778 (req_offset(req) + req->wb_bytes == i_size_read(pgio->pg_inode))) { 779 /* 780 * If the write goes up to the inode size, just write 781 * the full page. Data past the inode size is 782 * guaranteed to be zeroed by the higher level client 783 * code, and this behaviour is mandated by RFC 5663 784 * section 2.3.2. 785 */ 786 return true; 787 } 788 789 return false; 790 } 791 792 static void 793 bl_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req) 794 { 795 if (!is_aligned_req(pgio, req, SECTOR_SIZE, false)) { 796 nfs_pageio_reset_read_mds(pgio); 797 return; 798 } 799 800 pnfs_generic_pg_init_read(pgio, req); 801 } 802 803 /* 804 * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number 805 * of bytes (maximum @req->wb_bytes) that can be coalesced. 806 */ 807 static size_t 808 bl_pg_test_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, 809 struct nfs_page *req) 810 { 811 if (!is_aligned_req(pgio, req, SECTOR_SIZE, false)) 812 return 0; 813 return pnfs_generic_pg_test(pgio, prev, req); 814 } 815 816 /* 817 * Return the number of contiguous bytes for a given inode 818 * starting at page frame idx. 819 */ 820 static u64 pnfs_num_cont_bytes(struct inode *inode, pgoff_t idx) 821 { 822 struct address_space *mapping = inode->i_mapping; 823 pgoff_t end; 824 825 /* Optimize common case that writes from 0 to end of file */ 826 end = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); 827 if (end != inode->i_mapping->nrpages) { 828 rcu_read_lock(); 829 end = page_cache_next_hole(mapping, idx + 1, ULONG_MAX); 830 rcu_read_unlock(); 831 } 832 833 if (!end) 834 return i_size_read(inode) - (idx << PAGE_SHIFT); 835 else 836 return (end - idx) << PAGE_SHIFT; 837 } 838 839 static void 840 bl_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req) 841 { 842 u64 wb_size; 843 844 if (!is_aligned_req(pgio, req, PAGE_SIZE, true)) { 845 nfs_pageio_reset_write_mds(pgio); 846 return; 847 } 848 849 if (pgio->pg_dreq == NULL) 850 wb_size = pnfs_num_cont_bytes(pgio->pg_inode, 851 req->wb_index); 852 else 853 wb_size = nfs_dreq_bytes_left(pgio->pg_dreq); 854 855 pnfs_generic_pg_init_write(pgio, req, wb_size); 856 } 857 858 /* 859 * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number 860 * of bytes (maximum @req->wb_bytes) that can be coalesced. 861 */ 862 static size_t 863 bl_pg_test_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, 864 struct nfs_page *req) 865 { 866 if (!is_aligned_req(pgio, req, PAGE_SIZE, true)) 867 return 0; 868 return pnfs_generic_pg_test(pgio, prev, req); 869 } 870 871 static const struct nfs_pageio_ops bl_pg_read_ops = { 872 .pg_init = bl_pg_init_read, 873 .pg_test = bl_pg_test_read, 874 .pg_doio = pnfs_generic_pg_readpages, 875 .pg_cleanup = pnfs_generic_pg_cleanup, 876 }; 877 878 static const struct nfs_pageio_ops bl_pg_write_ops = { 879 .pg_init = bl_pg_init_write, 880 .pg_test = bl_pg_test_write, 881 .pg_doio = pnfs_generic_pg_writepages, 882 .pg_cleanup = pnfs_generic_pg_cleanup, 883 }; 884 885 static struct pnfs_layoutdriver_type blocklayout_type = { 886 .id = LAYOUT_BLOCK_VOLUME, 887 .name = "LAYOUT_BLOCK_VOLUME", 888 .owner = THIS_MODULE, 889 .flags = PNFS_LAYOUTRET_ON_SETATTR | 890 PNFS_READ_WHOLE_PAGE, 891 .read_pagelist = bl_read_pagelist, 892 .write_pagelist = bl_write_pagelist, 893 .alloc_layout_hdr = bl_alloc_layout_hdr, 894 .free_layout_hdr = bl_free_layout_hdr, 895 .alloc_lseg = bl_alloc_lseg, 896 .free_lseg = bl_free_lseg, 897 .return_range = bl_return_range, 898 .prepare_layoutcommit = bl_prepare_layoutcommit, 899 .cleanup_layoutcommit = bl_cleanup_layoutcommit, 900 .set_layoutdriver = bl_set_layoutdriver, 901 .alloc_deviceid_node = bl_alloc_deviceid_node, 902 .free_deviceid_node = bl_free_deviceid_node, 903 .pg_read_ops = &bl_pg_read_ops, 904 .pg_write_ops = &bl_pg_write_ops, 905 .sync = pnfs_generic_sync, 906 }; 907 908 static struct pnfs_layoutdriver_type scsilayout_type = { 909 .id = LAYOUT_SCSI, 910 .name = "LAYOUT_SCSI", 911 .owner = THIS_MODULE, 912 .flags = PNFS_LAYOUTRET_ON_SETATTR | 913 PNFS_READ_WHOLE_PAGE, 914 .read_pagelist = bl_read_pagelist, 915 .write_pagelist = bl_write_pagelist, 916 .alloc_layout_hdr = sl_alloc_layout_hdr, 917 .free_layout_hdr = bl_free_layout_hdr, 918 .alloc_lseg = bl_alloc_lseg, 919 .free_lseg = bl_free_lseg, 920 .return_range = bl_return_range, 921 .prepare_layoutcommit = bl_prepare_layoutcommit, 922 .cleanup_layoutcommit = bl_cleanup_layoutcommit, 923 .set_layoutdriver = bl_set_layoutdriver, 924 .alloc_deviceid_node = bl_alloc_deviceid_node, 925 .free_deviceid_node = bl_free_deviceid_node, 926 .pg_read_ops = &bl_pg_read_ops, 927 .pg_write_ops = &bl_pg_write_ops, 928 .sync = pnfs_generic_sync, 929 }; 930 931 932 static int __init nfs4blocklayout_init(void) 933 { 934 int ret; 935 936 dprintk("%s: NFSv4 Block Layout Driver Registering...\n", __func__); 937 938 ret = bl_init_pipefs(); 939 if (ret) 940 goto out; 941 942 ret = pnfs_register_layoutdriver(&blocklayout_type); 943 if (ret) 944 goto out_cleanup_pipe; 945 946 ret = pnfs_register_layoutdriver(&scsilayout_type); 947 if (ret) 948 goto out_unregister_block; 949 return 0; 950 951 out_unregister_block: 952 pnfs_unregister_layoutdriver(&blocklayout_type); 953 out_cleanup_pipe: 954 bl_cleanup_pipefs(); 955 out: 956 return ret; 957 } 958 959 static void __exit nfs4blocklayout_exit(void) 960 { 961 dprintk("%s: NFSv4 Block Layout Driver Unregistering...\n", 962 __func__); 963 964 pnfs_unregister_layoutdriver(&scsilayout_type); 965 pnfs_unregister_layoutdriver(&blocklayout_type); 966 bl_cleanup_pipefs(); 967 } 968 969 MODULE_ALIAS("nfs-layouttype4-3"); 970 971 module_init(nfs4blocklayout_init); 972 module_exit(nfs4blocklayout_exit); 973