fs/nfs/blocklayout/blocklayout.c

   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 bool offset_in_map(u64 offset, struct pnfs_block_dev_map *map)
 119 {
 120         return offset >= map->start && offset < map->start + map->len;
 121 }
 122
 123 static struct bio *
 124 do_add_page_to_bio(struct bio *bio, int npg, enum req_op op, sector_t isect,
 125                 struct page *page, struct pnfs_block_dev_map *map,
 126                 struct pnfs_block_extent *be, bio_end_io_t end_io,
 127                 struct parallel_io *par, unsigned int offset, int *len)
 128 {
 129         struct pnfs_block_dev *dev =
 130                 container_of(be->be_device, struct pnfs_block_dev, node);
 131         u64 disk_addr, end;
 132
 133         dprintk("%s: npg %d rw %d isect %llu offset %u len %d\n", __func__,
 134                 npg, (__force u32)op, (unsigned long long)isect, offset, *len);
 135
 136         /* translate to device offset */
 137         isect += be->be_v_offset;
 138         isect -= be->be_f_offset;
 139
 140         /* translate to physical disk offset */
 141         disk_addr = (u64)isect << SECTOR_SHIFT;
 142         if (!offset_in_map(disk_addr, map)) {
 143                 if (!dev->map(dev, disk_addr, map) || !offset_in_map(disk_addr, map))
 144                         return ERR_PTR(-EIO);
 145                 bio = bl_submit_bio(bio);
 146         }
 147         disk_addr += map->disk_offset;
 148         disk_addr -= map->start;
 149
 150         /* limit length to what the device mapping allows */
 151         end = disk_addr + *len;
 152         if (end >= map->start + map->len)
 153                 *len = map->start + map->len - disk_addr;
 154
 155 retry:
 156         if (!bio) {
 157                 bio = bio_alloc(map->bdev, bio_max_segs(npg), op, GFP_NOIO);
 158                 bio->bi_iter.bi_sector = disk_addr >> SECTOR_SHIFT;
 159                 bio->bi_end_io = end_io;
 160                 bio->bi_private = par;
 161         }
 162         if (bio_add_page(bio, page, *len, offset) < *len) {
 163                 bio = bl_submit_bio(bio);
 164                 goto retry;
 165         }
 166         return bio;
 167 }
 168
 169 static void bl_mark_devices_unavailable(struct nfs_pgio_header *header, bool rw)
 170 {
 171         struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg);
 172         size_t bytes_left = header->args.count;
 173         sector_t isect, extent_length = 0;
 174         struct pnfs_block_extent be;
 175
 176         isect = header->args.offset >> SECTOR_SHIFT;
 177         bytes_left += header->args.offset - (isect << SECTOR_SHIFT);
 178
 179         while (bytes_left > 0) {
 180                 if (!ext_tree_lookup(bl, isect, &be, rw))
 181                                 return;
 182                 extent_length = be.be_length - (isect - be.be_f_offset);
 183                 nfs4_mark_deviceid_unavailable(be.be_device);
 184                 isect += extent_length;
 185                 if (bytes_left > extent_length << SECTOR_SHIFT)
 186                         bytes_left -= extent_length << SECTOR_SHIFT;
 187                 else
 188                         bytes_left = 0;
 189         }
 190 }
 191
 192 static void bl_end_io_read(struct bio *bio)
 193 {
 194         struct parallel_io *par = bio->bi_private;
 195
 196         if (bio->bi_status) {
 197                 struct nfs_pgio_header *header = par->data;
 198
 199                 if (!header->pnfs_error)
 200                         header->pnfs_error = -EIO;
 201                 pnfs_set_lo_fail(header->lseg);
 202                 bl_mark_devices_unavailable(header, false);
 203         }
 204
 205         bio_put(bio);
 206         put_parallel(par);
 207 }
 208
 209 static void bl_read_cleanup(struct work_struct *work)
 210 {
 211         struct rpc_task *task;
 212         struct nfs_pgio_header *hdr;
 213         dprintk("%s enter\n", __func__);
 214         task = container_of(work, struct rpc_task, u.tk_work);
 215         hdr = container_of(task, struct nfs_pgio_header, task);
 216         pnfs_ld_read_done(hdr);
 217 }
 218
 219 static void
 220 bl_end_par_io_read(void *data)
 221 {
 222         struct nfs_pgio_header *hdr = data;
 223
 224         hdr->task.tk_status = hdr->pnfs_error;
 225         INIT_WORK(&hdr->task.u.tk_work, bl_read_cleanup);
 226         schedule_work(&hdr->task.u.tk_work);
 227 }
 228
 229 static enum pnfs_try_status
 230 bl_read_pagelist(struct nfs_pgio_header *header)
 231 {
 232         struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg);
 233         struct pnfs_block_dev_map map = { .start = NFS4_MAX_UINT64 };
 234         struct bio *bio = NULL;
 235         struct pnfs_block_extent be;
 236         sector_t isect, extent_length = 0;
 237         struct parallel_io *par;
 238         loff_t f_offset = header->args.offset;
 239         size_t bytes_left = header->args.count;
 240         unsigned int pg_offset = header->args.pgbase, pg_len;
 241         struct page **pages = header->args.pages;
 242         int pg_index = header->args.pgbase >> PAGE_SHIFT;
 243         const bool is_dio = (header->dreq != NULL);
 244         struct blk_plug plug;
 245         int i;
 246
 247         dprintk("%s enter nr_pages %u offset %lld count %u\n", __func__,
 248                 header->page_array.npages, f_offset,
 249                 (unsigned int)header->args.count);
 250
 251         par = alloc_parallel(header);
 252         if (!par)
 253                 return PNFS_NOT_ATTEMPTED;
 254         par->pnfs_callback = bl_end_par_io_read;
 255
 256         blk_start_plug(&plug);
 257
 258         isect = (sector_t) (f_offset >> SECTOR_SHIFT);
 259         /* Code assumes extents are page-aligned */
 260         for (i = pg_index; i < header->page_array.npages; i++) {
 261                 if (extent_length <= 0) {
 262                         /* We've used up the previous extent */
 263                         bio = bl_submit_bio(bio);
 264
 265                         /* Get the next one */
 266                         if (!ext_tree_lookup(bl, isect, &be, false)) {
 267                                 header->pnfs_error = -EIO;
 268                                 goto out;
 269                         }
 270                         extent_length = be.be_length - (isect - be.be_f_offset);
 271                 }
 272
 273                 if (is_dio) {
 274                         if (pg_offset + bytes_left > PAGE_SIZE)
 275                                 pg_len = PAGE_SIZE - pg_offset;
 276                         else
 277                                 pg_len = bytes_left;
 278                 } else {
 279                         BUG_ON(pg_offset != 0);
 280                         pg_len = PAGE_SIZE;
 281                 }
 282
 283                 if (is_hole(&be)) {
 284                         bio = bl_submit_bio(bio);
 285                         /* Fill hole w/ zeroes w/o accessing device */
 286                         dprintk("%s Zeroing page for hole\n", __func__);
 287                         zero_user_segment(pages[i], pg_offset, pg_len);
 288
 289                         /* invalidate map */
 290                         map.start = NFS4_MAX_UINT64;
 291                 } else {
 292                         bio = do_add_page_to_bio(bio,
 293                                                  header->page_array.npages - i,
 294                                                  REQ_OP_READ,
 295                                                  isect, pages[i], &map, &be,
 296                                                  bl_end_io_read, par,
 297                                                  pg_offset, &pg_len);
 298                         if (IS_ERR(bio)) {
 299                                 header->pnfs_error = PTR_ERR(bio);
 300                                 bio = NULL;
 301                                 goto out;
 302                         }
 303                 }
 304                 isect += (pg_len >> SECTOR_SHIFT);
 305                 extent_length -= (pg_len >> SECTOR_SHIFT);
 306                 f_offset += pg_len;
 307                 bytes_left -= pg_len;
 308                 pg_offset = 0;
 309         }
 310         if ((isect << SECTOR_SHIFT) >= header->inode->i_size) {
 311                 header->res.eof = 1;
 312                 header->res.count = header->inode->i_size - header->args.offset;
 313         } else {
 314                 header->res.count = (isect << SECTOR_SHIFT) - header->args.offset;
 315         }
 316 out:
 317         bl_submit_bio(bio);
 318         blk_finish_plug(&plug);
 319         put_parallel(par);
 320         return PNFS_ATTEMPTED;
 321 }
 322
 323 static void bl_end_io_write(struct bio *bio)
 324 {
 325         struct parallel_io *par = bio->bi_private;
 326         struct nfs_pgio_header *header = par->data;
 327
 328         if (bio->bi_status) {
 329                 if (!header->pnfs_error)
 330                         header->pnfs_error = -EIO;
 331                 pnfs_set_lo_fail(header->lseg);
 332                 bl_mark_devices_unavailable(header, true);
 333         }
 334         bio_put(bio);
 335         put_parallel(par);
 336 }
 337
 338 /* Function scheduled for call during bl_end_par_io_write,
 339  * it marks sectors as written and extends the commitlist.
 340  */
 341 static void bl_write_cleanup(struct work_struct *work)
 342 {
 343         struct rpc_task *task = container_of(work, struct rpc_task, u.tk_work);
 344         struct nfs_pgio_header *hdr =
 345                         container_of(task, struct nfs_pgio_header, task);
 346
 347         dprintk("%s enter\n", __func__);
 348
 349         if (likely(!hdr->pnfs_error)) {
 350                 struct pnfs_block_layout *bl = BLK_LSEG2EXT(hdr->lseg);
 351                 u64 start = hdr->args.offset & (loff_t)PAGE_MASK;
 352                 u64 end = (hdr->args.offset + hdr->args.count +
 353                         PAGE_SIZE - 1) & (loff_t)PAGE_MASK;
 354                 u64 lwb = hdr->args.offset + hdr->args.count;
 355
 356                 ext_tree_mark_written(bl, start >> SECTOR_SHIFT,
 357                                         (end - start) >> SECTOR_SHIFT, lwb);
 358         }
 359
 360         pnfs_ld_write_done(hdr);
 361 }
 362
 363 /* Called when last of bios associated with a bl_write_pagelist call finishes */
 364 static void bl_end_par_io_write(void *data)
 365 {
 366         struct nfs_pgio_header *hdr = data;
 367
 368         hdr->task.tk_status = hdr->pnfs_error;
 369         hdr->verf.committed = NFS_FILE_SYNC;
 370         INIT_WORK(&hdr->task.u.tk_work, bl_write_cleanup);
 371         schedule_work(&hdr->task.u.tk_work);
 372 }
 373
 374 static enum pnfs_try_status
 375 bl_write_pagelist(struct nfs_pgio_header *header, int sync)
 376 {
 377         struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg);
 378         struct pnfs_block_dev_map map = { .start = NFS4_MAX_UINT64 };
 379         struct bio *bio = NULL;
 380         struct pnfs_block_extent be;
 381         sector_t isect, extent_length = 0;
 382         struct parallel_io *par = NULL;
 383         loff_t offset = header->args.offset;
 384         size_t count = header->args.count;
 385         struct page **pages = header->args.pages;
 386         int pg_index = header->args.pgbase >> PAGE_SHIFT;
 387         unsigned int pg_len;
 388         struct blk_plug plug;
 389         int i;
 390
 391         dprintk("%s enter, %zu@%lld\n", __func__, count, offset);
 392
 393         /* At this point, header->page_aray is a (sequential) list of nfs_pages.
 394          * We want to write each, and if there is an error set pnfs_error
 395          * to have it redone using nfs.
 396          */
 397         par = alloc_parallel(header);
 398         if (!par)
 399                 return PNFS_NOT_ATTEMPTED;
 400         par->pnfs_callback = bl_end_par_io_write;
 401
 402         blk_start_plug(&plug);
 403
 404         /* we always write out the whole page */
 405         offset = offset & (loff_t)PAGE_MASK;
 406         isect = offset >> SECTOR_SHIFT;
 407
 408         for (i = pg_index; i < header->page_array.npages; i++) {
 409                 if (extent_length <= 0) {
 410                         /* We've used up the previous extent */
 411                         bio = bl_submit_bio(bio);
 412                         /* Get the next one */
 413                         if (!ext_tree_lookup(bl, isect, &be, true)) {
 414                                 header->pnfs_error = -EINVAL;
 415                                 goto out;
 416                         }
 417
 418                         extent_length = be.be_length - (isect - be.be_f_offset);
 419                 }
 420
 421                 pg_len = PAGE_SIZE;
 422                 bio = do_add_page_to_bio(bio, header->page_array.npages - i,
 423                                          REQ_OP_WRITE, isect, pages[i], &map,
 424                                          &be, bl_end_io_write, par, 0, &pg_len);
 425                 if (IS_ERR(bio)) {
 426                         header->pnfs_error = PTR_ERR(bio);
 427                         bio = NULL;
 428                         goto out;
 429                 }
 430
 431                 offset += pg_len;
 432                 count -= pg_len;
 433                 isect += (pg_len >> SECTOR_SHIFT);
 434                 extent_length -= (pg_len >> SECTOR_SHIFT);
 435         }
 436
 437         header->res.count = header->args.count;
 438 out:
 439         bl_submit_bio(bio);
 440         blk_finish_plug(&plug);
 441         put_parallel(par);
 442         return PNFS_ATTEMPTED;
 443 }
 444
 445 static void bl_free_layout_hdr(struct pnfs_layout_hdr *lo)
 446 {
 447         struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
 448         int err;
 449
 450         dprintk("%s enter\n", __func__);
 451
 452         err = ext_tree_remove(bl, true, 0, LLONG_MAX);
 453         WARN_ON(err);
 454
 455         kfree_rcu(bl, bl_layout.plh_rcu);
 456 }
 457
 458 static struct pnfs_layout_hdr *__bl_alloc_layout_hdr(struct inode *inode,
 459                 gfp_t gfp_flags, bool is_scsi_layout)
 460 {
 461         struct pnfs_block_layout *bl;
 462
 463         dprintk("%s enter\n", __func__);
 464         bl = kzalloc(sizeof(*bl), gfp_flags);
 465         if (!bl)
 466                 return NULL;
 467
 468         bl->bl_ext_rw = RB_ROOT;
 469         bl->bl_ext_ro = RB_ROOT;
 470         spin_lock_init(&bl->bl_ext_lock);
 471
 472         bl->bl_scsi_layout = is_scsi_layout;
 473         return &bl->bl_layout;
 474 }
 475
 476 static struct pnfs_layout_hdr *bl_alloc_layout_hdr(struct inode *inode,
 477                                                    gfp_t gfp_flags)
 478 {
 479         return __bl_alloc_layout_hdr(inode, gfp_flags, false);
 480 }
 481
 482 static struct pnfs_layout_hdr *sl_alloc_layout_hdr(struct inode *inode,
 483                                                    gfp_t gfp_flags)
 484 {
 485         return __bl_alloc_layout_hdr(inode, gfp_flags, true);
 486 }
 487
 488 static void bl_free_lseg(struct pnfs_layout_segment *lseg)
 489 {
 490         dprintk("%s enter\n", __func__);
 491         kfree(lseg);
 492 }
 493
 494 /* Tracks info needed to ensure extents in layout obey constraints of spec */
 495 struct layout_verification {
 496         u32 mode;       /* R or RW */
 497         u64 start;      /* Expected start of next non-COW extent */
 498         u64 inval;      /* Start of INVAL coverage */
 499         u64 cowread;    /* End of COW read coverage */
 500 };
 501
 502 /* Verify the extent meets the layout requirements of the pnfs-block draft,
 503  * section 2.3.1.
 504  */
 505 static int verify_extent(struct pnfs_block_extent *be,
 506                          struct layout_verification *lv)
 507 {
 508         if (lv->mode == IOMODE_READ) {
 509                 if (be->be_state == PNFS_BLOCK_READWRITE_DATA ||
 510                     be->be_state == PNFS_BLOCK_INVALID_DATA)
 511                         return -EIO;
 512                 if (be->be_f_offset != lv->start)
 513                         return -EIO;
 514                 lv->start += be->be_length;
 515                 return 0;
 516         }
 517         /* lv->mode == IOMODE_RW */
 518         if (be->be_state == PNFS_BLOCK_READWRITE_DATA) {
 519                 if (be->be_f_offset != lv->start)
 520                         return -EIO;
 521                 if (lv->cowread > lv->start)
 522                         return -EIO;
 523                 lv->start += be->be_length;
 524                 lv->inval = lv->start;
 525                 return 0;
 526         } else if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
 527                 if (be->be_f_offset != lv->start)
 528                         return -EIO;
 529                 lv->start += be->be_length;
 530                 return 0;
 531         } else if (be->be_state == PNFS_BLOCK_READ_DATA) {
 532                 if (be->be_f_offset > lv->start)
 533                         return -EIO;
 534                 if (be->be_f_offset < lv->inval)
 535                         return -EIO;
 536                 if (be->be_f_offset < lv->cowread)
 537                         return -EIO;
 538                 /* It looks like you might want to min this with lv->start,
 539                  * but you really don't.
 540                  */
 541                 lv->inval = lv->inval + be->be_length;
 542                 lv->cowread = be->be_f_offset + be->be_length;
 543                 return 0;
 544         } else
 545                 return -EIO;
 546 }
 547
 548 static int decode_sector_number(__be32 **rp, sector_t *sp)
 549 {
 550         uint64_t s;
 551
 552         *rp = xdr_decode_hyper(*rp, &s);
 553         if (s & 0x1ff) {
 554                 printk(KERN_WARNING "NFS: %s: sector not aligned\n", __func__);
 555                 return -1;
 556         }
 557         *sp = s >> SECTOR_SHIFT;
 558         return 0;
 559 }
 560
 561 static struct nfs4_deviceid_node *
 562 bl_find_get_deviceid(struct nfs_server *server,
 563                 const struct nfs4_deviceid *id, const struct cred *cred,
 564                 gfp_t gfp_mask)
 565 {
 566         struct nfs4_deviceid_node *node;
 567         unsigned long start, end;
 568
 569 retry:
 570         node = nfs4_find_get_deviceid(server, id, cred, gfp_mask);
 571         if (!node)
 572                 return ERR_PTR(-ENODEV);
 573
 574         if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags) == 0)
 575                 return node;
 576
 577         end = jiffies;
 578         start = end - PNFS_DEVICE_RETRY_TIMEOUT;
 579         if (!time_in_range(node->timestamp_unavailable, start, end)) {
 580                 nfs4_delete_deviceid(node->ld, node->nfs_client, id);
 581                 goto retry;
 582         }
 583         return ERR_PTR(-ENODEV);
 584 }
 585
 586 static int
 587 bl_alloc_extent(struct xdr_stream *xdr, struct pnfs_layout_hdr *lo,
 588                 struct layout_verification *lv, struct list_head *extents,
 589                 gfp_t gfp_mask)
 590 {
 591         struct pnfs_block_extent *be;
 592         struct nfs4_deviceid id;
 593         int error;
 594         __be32 *p;
 595
 596         p = xdr_inline_decode(xdr, 28 + NFS4_DEVICEID4_SIZE);
 597         if (!p)
 598                 return -EIO;
 599
 600         be = kzalloc(sizeof(*be), GFP_NOFS);
 601         if (!be)
 602                 return -ENOMEM;
 603
 604         memcpy(&id, p, NFS4_DEVICEID4_SIZE);
 605         p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
 606
 607         be->be_device = bl_find_get_deviceid(NFS_SERVER(lo->plh_inode), &id,
 608                                                 lo->plh_lc_cred, gfp_mask);
 609         if (IS_ERR(be->be_device)) {
 610                 error = PTR_ERR(be->be_device);
 611                 goto out_free_be;
 612         }
 613
 614         /*
 615          * The next three values are read in as bytes, but stored in the
 616          * extent structure in 512-byte granularity.
 617          */
 618         error = -EIO;
 619         if (decode_sector_number(&p, &be->be_f_offset) < 0)
 620                 goto out_put_deviceid;
 621         if (decode_sector_number(&p, &be->be_length) < 0)
 622                 goto out_put_deviceid;
 623         if (decode_sector_number(&p, &be->be_v_offset) < 0)
 624                 goto out_put_deviceid;
 625         be->be_state = be32_to_cpup(p++);
 626
 627         error = verify_extent(be, lv);
 628         if (error) {
 629                 dprintk("%s: extent verification failed\n", __func__);
 630                 goto out_put_deviceid;
 631         }
 632
 633         list_add_tail(&be->be_list, extents);
 634         return 0;
 635
 636 out_put_deviceid:
 637         nfs4_put_deviceid_node(be->be_device);
 638 out_free_be:
 639         kfree(be);
 640         return error;
 641 }
 642
 643 static struct pnfs_layout_segment *
 644 bl_alloc_lseg(struct pnfs_layout_hdr *lo, struct nfs4_layoutget_res *lgr,
 645                 gfp_t gfp_mask)
 646 {
 647         struct layout_verification lv = {
 648                 .mode = lgr->range.iomode,
 649                 .start = lgr->range.offset >> SECTOR_SHIFT,
 650                 .inval = lgr->range.offset >> SECTOR_SHIFT,
 651                 .cowread = lgr->range.offset >> SECTOR_SHIFT,
 652         };
 653         struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
 654         struct pnfs_layout_segment *lseg;
 655         struct xdr_buf buf;
 656         struct xdr_stream xdr;
 657         struct page *scratch;
 658         int status, i;
 659         uint32_t count;
 660         __be32 *p;
 661         LIST_HEAD(extents);
 662
 663         dprintk("---> %s\n", __func__);
 664
 665         lseg = kzalloc(sizeof(*lseg), gfp_mask);
 666         if (!lseg)
 667                 return ERR_PTR(-ENOMEM);
 668
 669         status = -ENOMEM;
 670         scratch = alloc_page(gfp_mask);
 671         if (!scratch)
 672                 goto out;
 673
 674         xdr_init_decode_pages(&xdr, &buf,
 675                         lgr->layoutp->pages, lgr->layoutp->len);
 676         xdr_set_scratch_page(&xdr, scratch);
 677
 678         status = -EIO;
 679         p = xdr_inline_decode(&xdr, 4);
 680         if (unlikely(!p))
 681                 goto out_free_scratch;
 682
 683         count = be32_to_cpup(p++);
 684         dprintk("%s: number of extents %d\n", __func__, count);
 685
 686         /*
 687          * Decode individual extents, putting them in temporary staging area
 688          * until whole layout is decoded to make error recovery easier.
 689          */
 690         for (i = 0; i < count; i++) {
 691                 status = bl_alloc_extent(&xdr, lo, &lv, &extents, gfp_mask);
 692                 if (status)
 693                         goto process_extents;
 694         }
 695
 696         if (lgr->range.offset + lgr->range.length !=
 697                         lv.start << SECTOR_SHIFT) {
 698                 dprintk("%s Final length mismatch\n", __func__);
 699                 status = -EIO;
 700                 goto process_extents;
 701         }
 702
 703         if (lv.start < lv.cowread) {
 704                 dprintk("%s Final uncovered COW extent\n", __func__);
 705                 status = -EIO;
 706         }
 707
 708 process_extents:
 709         while (!list_empty(&extents)) {
 710                 struct pnfs_block_extent *be =
 711                         list_first_entry(&extents, struct pnfs_block_extent,
 712                                          be_list);
 713                 list_del(&be->be_list);
 714
 715                 if (!status)
 716                         status = ext_tree_insert(bl, be);
 717
 718                 if (status) {
 719                         nfs4_put_deviceid_node(be->be_device);
 720                         kfree(be);
 721                 }
 722         }
 723
 724 out_free_scratch:
 725         __free_page(scratch);
 726 out:
 727         dprintk("%s returns %d\n", __func__, status);
 728         switch (status) {
 729         case -ENODEV:
 730                 /* Our extent block devices are unavailable */
 731                 set_bit(NFS_LSEG_UNAVAILABLE, &lseg->pls_flags);
 732                 fallthrough;
 733         case 0:
 734                 return lseg;
 735         default:
 736                 kfree(lseg);
 737                 return ERR_PTR(status);
 738         }
 739 }
 740
 741 static void
 742 bl_return_range(struct pnfs_layout_hdr *lo,
 743                 struct pnfs_layout_range *range)
 744 {
 745         struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
 746         sector_t offset = range->offset >> SECTOR_SHIFT, end;
 747
 748         if (range->offset % 8) {
 749                 dprintk("%s: offset %lld not block size aligned\n",
 750                         __func__, range->offset);
 751                 return;
 752         }
 753
 754         if (range->length != NFS4_MAX_UINT64) {
 755                 if (range->length % 8) {
 756                         dprintk("%s: length %lld not block size aligned\n",
 757                                 __func__, range->length);
 758                         return;
 759                 }
 760
 761                 end = offset + (range->length >> SECTOR_SHIFT);
 762         } else {
 763                 end = round_down(NFS4_MAX_UINT64, PAGE_SIZE);
 764         }
 765
 766         ext_tree_remove(bl, range->iomode & IOMODE_RW, offset, end);
 767 }
 768
 769 static int
 770 bl_prepare_layoutcommit(struct nfs4_layoutcommit_args *arg)
 771 {
 772         return ext_tree_prepare_commit(arg);
 773 }
 774
 775 static void
 776 bl_cleanup_layoutcommit(struct nfs4_layoutcommit_data *lcdata)
 777 {
 778         ext_tree_mark_committed(&lcdata->args, lcdata->res.status);
 779 }
 780
 781 static int
 782 bl_set_layoutdriver(struct nfs_server *server, const struct nfs_fh *fh)
 783 {
 784         dprintk("%s enter\n", __func__);
 785
 786         if (server->pnfs_blksize == 0) {
 787                 dprintk("%s Server did not return blksize\n", __func__);
 788                 return -EINVAL;
 789         }
 790         if (server->pnfs_blksize > PAGE_SIZE) {
 791                 printk(KERN_ERR "%s: pNFS blksize %d not supported.\n",
 792                         __func__, server->pnfs_blksize);
 793                 return -EINVAL;
 794         }
 795
 796         return 0;
 797 }
 798
 799 static bool
 800 is_aligned_req(struct nfs_pageio_descriptor *pgio,
 801                 struct nfs_page *req, unsigned int alignment, bool is_write)
 802 {
 803         /*
 804          * Always accept buffered writes, higher layers take care of the
 805          * right alignment.
 806          */
 807         if (pgio->pg_dreq == NULL)
 808                 return true;
 809
 810         if (!IS_ALIGNED(req->wb_offset, alignment))
 811                 return false;
 812
 813         if (IS_ALIGNED(req->wb_bytes, alignment))
 814                 return true;
 815
 816         if (is_write &&
 817             (req_offset(req) + req->wb_bytes == i_size_read(pgio->pg_inode))) {
 818                 /*
 819                  * If the write goes up to the inode size, just write
 820                  * the full page.  Data past the inode size is
 821                  * guaranteed to be zeroed by the higher level client
 822                  * code, and this behaviour is mandated by RFC 5663
 823                  * section 2.3.2.
 824                  */
 825                 return true;
 826         }
 827
 828         return false;
 829 }
 830
 831 static void
 832 bl_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
 833 {
 834         if (!is_aligned_req(pgio, req, SECTOR_SIZE, false)) {
 835                 nfs_pageio_reset_read_mds(pgio);
 836                 return;
 837         }
 838
 839         pnfs_generic_pg_init_read(pgio, req);
 840
 841         if (pgio->pg_lseg &&
 842                 test_bit(NFS_LSEG_UNAVAILABLE, &pgio->pg_lseg->pls_flags)) {
 843                 pnfs_error_mark_layout_for_return(pgio->pg_inode, pgio->pg_lseg);
 844                 pnfs_set_lo_fail(pgio->pg_lseg);
 845                 nfs_pageio_reset_read_mds(pgio);
 846         }
 847 }
 848
 849 /*
 850  * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
 851  * of bytes (maximum @req->wb_bytes) that can be coalesced.
 852  */
 853 static size_t
 854 bl_pg_test_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
 855                 struct nfs_page *req)
 856 {
 857         if (!is_aligned_req(pgio, req, SECTOR_SIZE, false))
 858                 return 0;
 859         return pnfs_generic_pg_test(pgio, prev, req);
 860 }
 861
 862 /*
 863  * Return the number of contiguous bytes for a given inode
 864  * starting at page frame idx.
 865  */
 866 static u64 pnfs_num_cont_bytes(struct inode *inode, pgoff_t idx)
 867 {
 868         struct address_space *mapping = inode->i_mapping;
 869         pgoff_t end;
 870
 871         /* Optimize common case that writes from 0 to end of file */
 872         end = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
 873         if (end != inode->i_mapping->nrpages) {
 874                 rcu_read_lock();
 875                 end = page_cache_next_miss(mapping, idx + 1, ULONG_MAX);
 876                 rcu_read_unlock();
 877         }
 878
 879         if (!end)
 880                 return i_size_read(inode) - (idx << PAGE_SHIFT);
 881         else
 882                 return (end - idx) << PAGE_SHIFT;
 883 }
 884
 885 static void
 886 bl_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
 887 {
 888         u64 wb_size;
 889
 890         if (!is_aligned_req(pgio, req, PAGE_SIZE, true)) {
 891                 nfs_pageio_reset_write_mds(pgio);
 892                 return;
 893         }
 894
 895         if (pgio->pg_dreq == NULL)
 896                 wb_size = pnfs_num_cont_bytes(pgio->pg_inode,
 897                                               req->wb_index);
 898         else
 899                 wb_size = nfs_dreq_bytes_left(pgio->pg_dreq);
 900
 901         pnfs_generic_pg_init_write(pgio, req, wb_size);
 902
 903         if (pgio->pg_lseg &&
 904                 test_bit(NFS_LSEG_UNAVAILABLE, &pgio->pg_lseg->pls_flags)) {
 905
 906                 pnfs_error_mark_layout_for_return(pgio->pg_inode, pgio->pg_lseg);
 907                 pnfs_set_lo_fail(pgio->pg_lseg);
 908                 nfs_pageio_reset_write_mds(pgio);
 909         }
 910 }
 911
 912 /*
 913  * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
 914  * of bytes (maximum @req->wb_bytes) that can be coalesced.
 915  */
 916 static size_t
 917 bl_pg_test_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
 918                  struct nfs_page *req)
 919 {
 920         if (!is_aligned_req(pgio, req, PAGE_SIZE, true))
 921                 return 0;
 922         return pnfs_generic_pg_test(pgio, prev, req);
 923 }
 924
 925 static const struct nfs_pageio_ops bl_pg_read_ops = {
 926         .pg_init = bl_pg_init_read,
 927         .pg_test = bl_pg_test_read,
 928         .pg_doio = pnfs_generic_pg_readpages,
 929         .pg_cleanup = pnfs_generic_pg_cleanup,
 930 };
 931
 932 static const struct nfs_pageio_ops bl_pg_write_ops = {
 933         .pg_init = bl_pg_init_write,
 934         .pg_test = bl_pg_test_write,
 935         .pg_doio = pnfs_generic_pg_writepages,
 936         .pg_cleanup = pnfs_generic_pg_cleanup,
 937 };
 938
 939 static struct pnfs_layoutdriver_type blocklayout_type = {
 940         .id                             = LAYOUT_BLOCK_VOLUME,
 941         .name                           = "LAYOUT_BLOCK_VOLUME",
 942         .owner                          = THIS_MODULE,
 943         .flags                          = PNFS_LAYOUTRET_ON_SETATTR |
 944                                           PNFS_LAYOUTRET_ON_ERROR |
 945                                           PNFS_READ_WHOLE_PAGE,
 946         .read_pagelist                  = bl_read_pagelist,
 947         .write_pagelist                 = bl_write_pagelist,
 948         .alloc_layout_hdr               = bl_alloc_layout_hdr,
 949         .free_layout_hdr                = bl_free_layout_hdr,
 950         .alloc_lseg                     = bl_alloc_lseg,
 951         .free_lseg                      = bl_free_lseg,
 952         .return_range                   = bl_return_range,
 953         .prepare_layoutcommit           = bl_prepare_layoutcommit,
 954         .cleanup_layoutcommit           = bl_cleanup_layoutcommit,
 955         .set_layoutdriver               = bl_set_layoutdriver,
 956         .alloc_deviceid_node            = bl_alloc_deviceid_node,
 957         .free_deviceid_node             = bl_free_deviceid_node,
 958         .pg_read_ops                    = &bl_pg_read_ops,
 959         .pg_write_ops                   = &bl_pg_write_ops,
 960         .sync                           = pnfs_generic_sync,
 961 };
 962
 963 static struct pnfs_layoutdriver_type scsilayout_type = {
 964         .id                             = LAYOUT_SCSI,
 965         .name                           = "LAYOUT_SCSI",
 966         .owner                          = THIS_MODULE,
 967         .flags                          = PNFS_LAYOUTRET_ON_SETATTR |
 968                                           PNFS_LAYOUTRET_ON_ERROR |
 969                                           PNFS_READ_WHOLE_PAGE,
 970         .read_pagelist                  = bl_read_pagelist,
 971         .write_pagelist                 = bl_write_pagelist,
 972         .alloc_layout_hdr               = sl_alloc_layout_hdr,
 973         .free_layout_hdr                = bl_free_layout_hdr,
 974         .alloc_lseg                     = bl_alloc_lseg,
 975         .free_lseg                      = bl_free_lseg,
 976         .return_range                   = bl_return_range,
 977         .prepare_layoutcommit           = bl_prepare_layoutcommit,
 978         .cleanup_layoutcommit           = bl_cleanup_layoutcommit,
 979         .set_layoutdriver               = bl_set_layoutdriver,
 980         .alloc_deviceid_node            = bl_alloc_deviceid_node,
 981         .free_deviceid_node             = bl_free_deviceid_node,
 982         .pg_read_ops                    = &bl_pg_read_ops,
 983         .pg_write_ops                   = &bl_pg_write_ops,
 984         .sync                           = pnfs_generic_sync,
 985 };
 986
 987
 988 static int __init nfs4blocklayout_init(void)
 989 {
 990         int ret;
 991
 992         dprintk("%s: NFSv4 Block Layout Driver Registering...\n", __func__);
 993
 994         ret = bl_init_pipefs();
 995         if (ret)
 996                 goto out;
 997
 998         ret = pnfs_register_layoutdriver(&blocklayout_type);
 999         if (ret)
1000                 goto out_cleanup_pipe;
1001
1002         ret = pnfs_register_layoutdriver(&scsilayout_type);
1003         if (ret)
1004                 goto out_unregister_block;
1005         return 0;
1006
1007 out_unregister_block:
1008         pnfs_unregister_layoutdriver(&blocklayout_type);
1009 out_cleanup_pipe:
1010         bl_cleanup_pipefs();
1011 out:
1012         return ret;
1013 }
1014
1015 static void __exit nfs4blocklayout_exit(void)
1016 {
1017         dprintk("%s: NFSv4 Block Layout Driver Unregistering...\n",
1018                __func__);
1019
1020         pnfs_unregister_layoutdriver(&scsilayout_type);
1021         pnfs_unregister_layoutdriver(&blocklayout_type);
1022         bl_cleanup_pipefs();
1023 }
1024
1025 MODULE_ALIAS("nfs-layouttype4-3");
1026 MODULE_ALIAS("nfs-layouttype4-5");
1027
1028 module_init(nfs4blocklayout_init);
1029 module_exit(nfs4blocklayout_exit);