git.oblomov.eu Git - linux-2.6/blob - fs/exofs/inode.c

   1 /*
   2  * Copyright (C) 2005, 2006
   3  * Avishay Traeger (avishay@gmail.com) (avishay@il.ibm.com)
   4  * Copyright (C) 2005, 2006
   5  * International Business Machines
   6  * Copyright (C) 2008, 2009
   7  * Boaz Harrosh <bharrosh@panasas.com>
   8  *
   9  * Copyrights for code taken from ext2:
  10  *     Copyright (C) 1992, 1993, 1994, 1995
  11  *     Remy Card (card@masi.ibp.fr)
  12  *     Laboratoire MASI - Institut Blaise Pascal
  13  *     Universite Pierre et Marie Curie (Paris VI)
  14  *     from
  15  *     linux/fs/minix/inode.c
  16  *     Copyright (C) 1991, 1992  Linus Torvalds
  17  *
  18  * This file is part of exofs.
  19  *
  20  * exofs is free software; you can redistribute it and/or modify
  21  * it under the terms of the GNU General Public License as published by
  22  * the Free Software Foundation.  Since it is based on ext2, and the only
  23  * valid version of GPL for the Linux kernel is version 2, the only valid
  24  * version of GPL for exofs is version 2.
  25  *
  26  * exofs is distributed in the hope that it will be useful,
  27  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  28  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  29  * GNU General Public License for more details.
  30  *
  31  * You should have received a copy of the GNU General Public License
  32  * along with exofs; if not, write to the Free Software
  33  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  34  */
  35
  36 #include <linux/writeback.h>
  37 #include <linux/buffer_head.h>
  38 #include <scsi/scsi_device.h>
  39
  40 #include "exofs.h"
  41
  42 #ifdef CONFIG_EXOFS_DEBUG
  43 #  define EXOFS_DEBUG_OBJ_ISIZE 1
  44 #endif
  45
  46 struct page_collect {
  47         struct exofs_sb_info *sbi;
  48         struct request_queue *req_q;
  49         struct inode *inode;
  50         unsigned expected_pages;
  51
  52         struct bio *bio;
  53         unsigned nr_pages;
  54         unsigned long length;
  55         loff_t pg_first; /* keep 64bit also in 32-arches */
  56 };
  57
  58 static void _pcol_init(struct page_collect *pcol, unsigned expected_pages,
  59                 struct inode *inode)
  60 {
  61         struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
  62
  63         pcol->sbi = sbi;
  64         pcol->req_q = osd_request_queue(sbi->s_dev);
  65         pcol->inode = inode;
  66         pcol->expected_pages = expected_pages;
  67
  68         pcol->bio = NULL;
  69         pcol->nr_pages = 0;
  70         pcol->length = 0;
  71         pcol->pg_first = -1;
  72
  73         EXOFS_DBGMSG("_pcol_init ino=0x%lx expected_pages=%u\n", inode->i_ino,
  74                      expected_pages);
  75 }
  76
  77 static void _pcol_reset(struct page_collect *pcol)
  78 {
  79         pcol->expected_pages -= min(pcol->nr_pages, pcol->expected_pages);
  80
  81         pcol->bio = NULL;
  82         pcol->nr_pages = 0;
  83         pcol->length = 0;
  84         pcol->pg_first = -1;
  85         EXOFS_DBGMSG("_pcol_reset ino=0x%lx expected_pages=%u\n",
  86                      pcol->inode->i_ino, pcol->expected_pages);
  87
  88         /* this is probably the end of the loop but in writes
  89          * it might not end here. don't be left with nothing
  90          */
  91         if (!pcol->expected_pages)
  92                 pcol->expected_pages = 128;
  93 }
  94
  95 static int pcol_try_alloc(struct page_collect *pcol)
  96 {
  97         int pages = min_t(unsigned, pcol->expected_pages, BIO_MAX_PAGES);
  98
  99         for (; pages; pages >>= 1) {
 100                 pcol->bio = bio_alloc(GFP_KERNEL, pages);
 101                 if (likely(pcol->bio))
 102                         return 0;
 103         }
 104
 105         EXOFS_ERR("Failed to kcalloc expected_pages=%u\n",
 106                   pcol->expected_pages);
 107         return -ENOMEM;
 108 }
 109
 110 static void pcol_free(struct page_collect *pcol)
 111 {
 112         bio_put(pcol->bio);
 113         pcol->bio = NULL;
 114 }
 115
 116 static int pcol_add_page(struct page_collect *pcol, struct page *page,
 117                          unsigned len)
 118 {
 119         int added_len = bio_add_pc_page(pcol->req_q, pcol->bio, page, len, 0);
 120         if (unlikely(len != added_len))
 121                 return -ENOMEM;
 122
 123         ++pcol->nr_pages;
 124         pcol->length += len;
 125         return 0;
 126 }
 127
 128 static int update_read_page(struct page *page, int ret)
 129 {
 130         if (ret == 0) {
 131                 /* Everything is OK */
 132                 SetPageUptodate(page);
 133                 if (PageError(page))
 134                         ClearPageError(page);
 135         } else if (ret == -EFAULT) {
 136                 /* In this case we were trying to read something that wasn't on
 137                  * disk yet - return a page full of zeroes.  This should be OK,
 138                  * because the object should be empty (if there was a write
 139                  * before this read, the read would be waiting with the page
 140                  * locked */
 141                 clear_highpage(page);
 142
 143                 SetPageUptodate(page);
 144                 if (PageError(page))
 145                         ClearPageError(page);
 146                 ret = 0; /* recovered error */
 147                 EXOFS_DBGMSG("recovered read error\n");
 148         } else /* Error */
 149                 SetPageError(page);
 150
 151         return ret;
 152 }
 153
 154 static void update_write_page(struct page *page, int ret)
 155 {
 156         if (ret) {
 157                 mapping_set_error(page->mapping, ret);
 158                 SetPageError(page);
 159         }
 160         end_page_writeback(page);
 161 }
 162
 163 /* Called at the end of reads, to optionally unlock pages and update their
 164  * status.
 165  */
 166 static int __readpages_done(struct osd_request *or, struct page_collect *pcol,
 167                             bool do_unlock)
 168 {
 169         struct bio_vec *bvec;
 170         int i;
 171         u64 resid;
 172         u64 good_bytes;
 173         u64 length = 0;
 174         int ret = exofs_check_ok_resid(or, &resid, NULL);
 175
 176         osd_end_request(or);
 177
 178         if (likely(!ret))
 179                 good_bytes = pcol->length;
 180         else if (!resid)
 181                 good_bytes = 0;
 182         else
 183                 good_bytes = pcol->length - resid;
 184
 185         EXOFS_DBGMSG("readpages_done(0x%lx) good_bytes=0x%llx"
 186                      " length=0x%lx nr_pages=%u\n",
 187                      pcol->inode->i_ino, _LLU(good_bytes), pcol->length,
 188                      pcol->nr_pages);
 189
 190         __bio_for_each_segment(bvec, pcol->bio, i, 0) {
 191                 struct page *page = bvec->bv_page;
 192                 struct inode *inode = page->mapping->host;
 193                 int page_stat;
 194
 195                 if (inode != pcol->inode)
 196                         continue; /* osd might add more pages at end */
 197
 198                 if (likely(length < good_bytes))
 199                         page_stat = 0;
 200                 else
 201                         page_stat = ret;
 202
 203                 EXOFS_DBGMSG("    readpages_done(0x%lx, 0x%lx) %s\n",
 204                           inode->i_ino, page->index,
 205                           page_stat ? "bad_bytes" : "good_bytes");
 206
 207                 ret = update_read_page(page, page_stat);
 208                 if (do_unlock)
 209                         unlock_page(page);
 210                 length += bvec->bv_len;
 211         }
 212
 213         pcol_free(pcol);
 214         EXOFS_DBGMSG("readpages_done END\n");
 215         return ret;
 216 }
 217
 218 /* callback of async reads */
 219 static void readpages_done(struct osd_request *or, void *p)
 220 {
 221         struct page_collect *pcol = p;
 222
 223         __readpages_done(or, pcol, true);
 224         atomic_dec(&pcol->sbi->s_curr_pending);
 225         kfree(p);
 226 }
 227
 228 static void _unlock_pcol_pages(struct page_collect *pcol, int ret, int rw)
 229 {
 230         struct bio_vec *bvec;
 231         int i;
 232
 233         __bio_for_each_segment(bvec, pcol->bio, i, 0) {
 234                 struct page *page = bvec->bv_page;
 235
 236                 if (rw == READ)
 237                         update_read_page(page, ret);
 238                 else
 239                         update_write_page(page, ret);
 240
 241                 unlock_page(page);
 242         }
 243         pcol_free(pcol);
 244 }
 245
 246 static int read_exec(struct page_collect *pcol, bool is_sync)
 247 {
 248         struct exofs_i_info *oi = exofs_i(pcol->inode);
 249         struct osd_obj_id obj = {pcol->sbi->s_pid,
 250                                         pcol->inode->i_ino + EXOFS_OBJ_OFF};
 251         struct osd_request *or = NULL;
 252         struct page_collect *pcol_copy = NULL;
 253         loff_t i_start = pcol->pg_first << PAGE_CACHE_SHIFT;
 254         int ret;
 255
 256         if (!pcol->bio)
 257                 return 0;
 258
 259         /* see comment in _readpage() about sync reads */
 260         WARN_ON(is_sync && (pcol->nr_pages != 1));
 261
 262         or = osd_start_request(pcol->sbi->s_dev, GFP_KERNEL);
 263         if (unlikely(!or)) {
 264                 ret = -ENOMEM;
 265                 goto err;
 266         }
 267
 268         osd_req_read(or, &obj, i_start, pcol->bio, pcol->length);
 269
 270         if (is_sync) {
 271                 exofs_sync_op(or, pcol->sbi->s_timeout, oi->i_cred);
 272                 return __readpages_done(or, pcol, false);
 273         }
 274
 275         pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
 276         if (!pcol_copy) {
 277                 ret = -ENOMEM;
 278                 goto err;
 279         }
 280
 281         *pcol_copy = *pcol;
 282         ret = exofs_async_op(or, readpages_done, pcol_copy, oi->i_cred);
 283         if (unlikely(ret))
 284                 goto err;
 285
 286         atomic_inc(&pcol->sbi->s_curr_pending);
 287
 288         EXOFS_DBGMSG("read_exec obj=0x%llx start=0x%llx length=0x%lx\n",
 289                   obj.id, _LLU(i_start), pcol->length);
 290
 291         /* pages ownership was passed to pcol_copy */
 292         _pcol_reset(pcol);
 293         return 0;
 294
 295 err:
 296         if (!is_sync)
 297                 _unlock_pcol_pages(pcol, ret, READ);
 298         kfree(pcol_copy);
 299         if (or)
 300                 osd_end_request(or);
 301         return ret;
 302 }
 303
 304 /* readpage_strip is called either directly from readpage() or by the VFS from
 305  * within read_cache_pages(), to add one more page to be read. It will try to
 306  * collect as many contiguous pages as posible. If a discontinuity is
 307  * encountered, or it runs out of resources, it will submit the previous segment
 308  * and will start a new collection. Eventually caller must submit the last
 309  * segment if present.
 310  */
 311 static int readpage_strip(void *data, struct page *page)
 312 {
 313         struct page_collect *pcol = data;
 314         struct inode *inode = pcol->inode;
 315         struct exofs_i_info *oi = exofs_i(inode);
 316         loff_t i_size = i_size_read(inode);
 317         pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
 318         size_t len;
 319         int ret;
 320
 321         /* FIXME: Just for debugging, will be removed */
 322         if (PageUptodate(page))
 323                 EXOFS_ERR("PageUptodate(0x%lx, 0x%lx)\n", pcol->inode->i_ino,
 324                           page->index);
 325
 326         if (page->index < end_index)
 327                 len = PAGE_CACHE_SIZE;
 328         else if (page->index == end_index)
 329                 len = i_size & ~PAGE_CACHE_MASK;
 330         else
 331                 len = 0;
 332
 333         if (!len || !obj_created(oi)) {
 334                 /* this will be out of bounds, or doesn't exist yet.
 335                  * Current page is cleared and the request is split
 336                  */
 337                 clear_highpage(page);
 338
 339                 SetPageUptodate(page);
 340                 if (PageError(page))
 341                         ClearPageError(page);
 342
 343                 unlock_page(page);
 344                 EXOFS_DBGMSG("readpage_strip(0x%lx, 0x%lx) empty page,"
 345                              " splitting\n", inode->i_ino, page->index);
 346
 347                 return read_exec(pcol, false);
 348         }
 349
 350 try_again:
 351
 352         if (unlikely(pcol->pg_first == -1)) {
 353                 pcol->pg_first = page->index;
 354         } else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
 355                    page->index)) {
 356                 /* Discontinuity detected, split the request */
 357                 ret = read_exec(pcol, false);
 358                 if (unlikely(ret))
 359                         goto fail;
 360                 goto try_again;
 361         }
 362
 363         if (!pcol->bio) {
 364                 ret = pcol_try_alloc(pcol);
 365                 if (unlikely(ret))
 366                         goto fail;
 367         }
 368
 369         if (len != PAGE_CACHE_SIZE)
 370                 zero_user(page, len, PAGE_CACHE_SIZE - len);
 371
 372         EXOFS_DBGMSG("    readpage_strip(0x%lx, 0x%lx) len=0x%zx\n",
 373                      inode->i_ino, page->index, len);
 374
 375         ret = pcol_add_page(pcol, page, len);
 376         if (ret) {
 377                 EXOFS_DBGMSG("Failed pcol_add_page pages[i]=%p "
 378                           "this_len=0x%zx nr_pages=%u length=0x%lx\n",
 379                           page, len, pcol->nr_pages, pcol->length);
 380
 381                 /* split the request, and start again with current page */
 382                 ret = read_exec(pcol, false);
 383                 if (unlikely(ret))
 384                         goto fail;
 385
 386                 goto try_again;
 387         }
 388
 389         return 0;
 390
 391 fail:
 392         /* SetPageError(page); ??? */
 393         unlock_page(page);
 394         return ret;
 395 }
 396
 397 static int exofs_readpages(struct file *file, struct address_space *mapping,
 398                            struct list_head *pages, unsigned nr_pages)
 399 {
 400         struct page_collect pcol;
 401         int ret;
 402
 403         _pcol_init(&pcol, nr_pages, mapping->host);
 404
 405         ret = read_cache_pages(mapping, pages, readpage_strip, &pcol);
 406         if (ret) {
 407                 EXOFS_ERR("read_cache_pages => %d\n", ret);
 408                 return ret;
 409         }
 410
 411         return read_exec(&pcol, false);
 412 }
 413
 414 static int _readpage(struct page *page, bool is_sync)
 415 {
 416         struct page_collect pcol;
 417         int ret;
 418
 419         _pcol_init(&pcol, 1, page->mapping->host);
 420
 421         /* readpage_strip might call read_exec(,async) inside at several places
 422          * but this is safe for is_async=0 since read_exec will not do anything
 423          * when we have a single page.
 424          */
 425         ret = readpage_strip(&pcol, page);
 426         if (ret) {
 427                 EXOFS_ERR("_readpage => %d\n", ret);
 428                 return ret;
 429         }
 430
 431         return read_exec(&pcol, is_sync);
 432 }
 433
 434 /*
 435  * We don't need the file
 436  */
 437 static int exofs_readpage(struct file *file, struct page *page)
 438 {
 439         return _readpage(page, false);
 440 }
 441
 442 /* Callback for osd_write. All writes are asynchronouse */
 443 static void writepages_done(struct osd_request *or, void *p)
 444 {
 445         struct page_collect *pcol = p;
 446         struct bio_vec *bvec;
 447         int i;
 448         u64 resid;
 449         u64  good_bytes;
 450         u64  length = 0;
 451
 452         int ret = exofs_check_ok_resid(or, NULL, &resid);
 453
 454         osd_end_request(or);
 455         atomic_dec(&pcol->sbi->s_curr_pending);
 456
 457         if (likely(!ret))
 458                 good_bytes = pcol->length;
 459         else if (!resid)
 460                 good_bytes = 0;
 461         else
 462                 good_bytes = pcol->length - resid;
 463
 464         EXOFS_DBGMSG("writepages_done(0x%lx) good_bytes=0x%llx"
 465                      " length=0x%lx nr_pages=%u\n",
 466                      pcol->inode->i_ino, _LLU(good_bytes), pcol->length,
 467                      pcol->nr_pages);
 468
 469         __bio_for_each_segment(bvec, pcol->bio, i, 0) {
 470                 struct page *page = bvec->bv_page;
 471                 struct inode *inode = page->mapping->host;
 472                 int page_stat;
 473
 474                 if (inode != pcol->inode)
 475                         continue; /* osd might add more pages to a bio */
 476
 477                 if (likely(length < good_bytes))
 478                         page_stat = 0;
 479                 else
 480                         page_stat = ret;
 481
 482                 update_write_page(page, page_stat);
 483                 unlock_page(page);
 484                 EXOFS_DBGMSG("    writepages_done(0x%lx, 0x%lx) status=%d\n",
 485                              inode->i_ino, page->index, page_stat);
 486
 487                 length += bvec->bv_len;
 488         }
 489
 490         pcol_free(pcol);
 491         kfree(pcol);
 492         EXOFS_DBGMSG("writepages_done END\n");
 493 }
 494
 495 static int write_exec(struct page_collect *pcol)
 496 {
 497         struct exofs_i_info *oi = exofs_i(pcol->inode);
 498         struct osd_obj_id obj = {pcol->sbi->s_pid,
 499                                         pcol->inode->i_ino + EXOFS_OBJ_OFF};
 500         struct osd_request *or = NULL;
 501         struct page_collect *pcol_copy = NULL;
 502         loff_t i_start = pcol->pg_first << PAGE_CACHE_SHIFT;
 503         int ret;
 504
 505         if (!pcol->bio)
 506                 return 0;
 507
 508         or = osd_start_request(pcol->sbi->s_dev, GFP_KERNEL);
 509         if (unlikely(!or)) {
 510                 EXOFS_ERR("write_exec: Faild to osd_start_request()\n");
 511                 ret = -ENOMEM;
 512                 goto err;
 513         }
 514
 515         pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
 516         if (!pcol_copy) {
 517                 EXOFS_ERR("write_exec: Faild to kmalloc(pcol)\n");
 518                 ret = -ENOMEM;
 519                 goto err;
 520         }
 521
 522         *pcol_copy = *pcol;
 523
 524         pcol_copy->bio->bi_rw |= (1 << BIO_RW); /* FIXME: bio_set_dir() */
 525         osd_req_write(or, &obj, i_start, pcol_copy->bio, pcol_copy->length);
 526         ret = exofs_async_op(or, writepages_done, pcol_copy, oi->i_cred);
 527         if (unlikely(ret)) {
 528                 EXOFS_ERR("write_exec: exofs_async_op() Faild\n");
 529                 goto err;
 530         }
 531
 532         atomic_inc(&pcol->sbi->s_curr_pending);
 533         EXOFS_DBGMSG("write_exec(0x%lx, 0x%llx) start=0x%llx length=0x%lx\n",
 534                   pcol->inode->i_ino, pcol->pg_first, _LLU(i_start),
 535                   pcol->length);
 536         /* pages ownership was passed to pcol_copy */
 537         _pcol_reset(pcol);
 538         return 0;
 539
 540 err:
 541         _unlock_pcol_pages(pcol, ret, WRITE);
 542         kfree(pcol_copy);
 543         if (or)
 544                 osd_end_request(or);
 545         return ret;
 546 }
 547
 548 /* writepage_strip is called either directly from writepage() or by the VFS from
 549  * within write_cache_pages(), to add one more page to be written to storage.
 550  * It will try to collect as many contiguous pages as possible. If a
 551  * discontinuity is encountered or it runs out of resources it will submit the
 552  * previous segment and will start a new collection.
 553  * Eventually caller must submit the last segment if present.
 554  */
 555 static int writepage_strip(struct page *page,
 556                            struct writeback_control *wbc_unused, void *data)
 557 {
 558         struct page_collect *pcol = data;
 559         struct inode *inode = pcol->inode;
 560         struct exofs_i_info *oi = exofs_i(inode);
 561         loff_t i_size = i_size_read(inode);
 562         pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
 563         size_t len;
 564         int ret;
 565
 566         BUG_ON(!PageLocked(page));
 567
 568         ret = wait_obj_created(oi);
 569         if (unlikely(ret))
 570                 goto fail;
 571
 572         if (page->index < end_index)
 573                 /* in this case, the page is within the limits of the file */
 574                 len = PAGE_CACHE_SIZE;
 575         else {
 576                 len = i_size & ~PAGE_CACHE_MASK;
 577
 578                 if (page->index > end_index || !len) {
 579                         /* in this case, the page is outside the limits
 580                          * (truncate in progress)
 581                          */
 582                         ret = write_exec(pcol);
 583                         if (unlikely(ret))
 584                                 goto fail;
 585                         if (PageError(page))
 586                                 ClearPageError(page);
 587                         unlock_page(page);
 588                         return 0;
 589                 }
 590         }
 591
 592 try_again:
 593
 594         if (unlikely(pcol->pg_first == -1)) {
 595                 pcol->pg_first = page->index;
 596         } else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
 597                    page->index)) {
 598                 /* Discontinuity detected, split the request */
 599                 ret = write_exec(pcol);
 600                 if (unlikely(ret))
 601                         goto fail;
 602                 goto try_again;
 603         }
 604
 605         if (!pcol->bio) {
 606                 ret = pcol_try_alloc(pcol);
 607                 if (unlikely(ret))
 608                         goto fail;
 609         }
 610
 611         EXOFS_DBGMSG("    writepage_strip(0x%lx, 0x%lx) len=0x%zx\n",
 612                      inode->i_ino, page->index, len);
 613
 614         ret = pcol_add_page(pcol, page, len);
 615         if (unlikely(ret)) {
 616                 EXOFS_DBGMSG("Failed pcol_add_page "
 617                              "nr_pages=%u total_length=0x%lx\n",
 618                              pcol->nr_pages, pcol->length);
 619
 620                 /* split the request, next loop will start again */
 621                 ret = write_exec(pcol);
 622                 if (unlikely(ret)) {
 623                         EXOFS_DBGMSG("write_exec faild => %d", ret);
 624                         goto fail;
 625                 }
 626
 627                 goto try_again;
 628         }
 629
 630         BUG_ON(PageWriteback(page));
 631         set_page_writeback(page);
 632
 633         return 0;
 634
 635 fail:
 636         set_bit(AS_EIO, &page->mapping->flags);
 637         unlock_page(page);
 638         return ret;
 639 }
 640
 641 static int exofs_writepages(struct address_space *mapping,
 642                        struct writeback_control *wbc)
 643 {
 644         struct page_collect pcol;
 645         long start, end, expected_pages;
 646         int ret;
 647
 648         start = wbc->range_start >> PAGE_CACHE_SHIFT;
 649         end = (wbc->range_end == LLONG_MAX) ?
 650                         start + mapping->nrpages :
 651                         wbc->range_end >> PAGE_CACHE_SHIFT;
 652
 653         if (start || end)
 654                 expected_pages = min(end - start + 1, 32L);
 655         else
 656                 expected_pages = mapping->nrpages;
 657
 658         EXOFS_DBGMSG("inode(0x%lx) wbc->start=0x%llx wbc->end=0x%llx"
 659                      " m->nrpages=%lu start=0x%lx end=0x%lx\n",
 660                      mapping->host->i_ino, wbc->range_start, wbc->range_end,
 661                      mapping->nrpages, start, end);
 662
 663         _pcol_init(&pcol, expected_pages, mapping->host);
 664
 665         ret = write_cache_pages(mapping, wbc, writepage_strip, &pcol);
 666         if (ret) {
 667                 EXOFS_ERR("write_cache_pages => %d\n", ret);
 668                 return ret;
 669         }
 670
 671         return write_exec(&pcol);
 672 }
 673
 674 static int exofs_writepage(struct page *page, struct writeback_control *wbc)
 675 {
 676         struct page_collect pcol;
 677         int ret;
 678
 679         _pcol_init(&pcol, 1, page->mapping->host);
 680
 681         ret = writepage_strip(page, NULL, &pcol);
 682         if (ret) {
 683                 EXOFS_ERR("exofs_writepage => %d\n", ret);
 684                 return ret;
 685         }
 686
 687         return write_exec(&pcol);
 688 }
 689
 690 int exofs_write_begin(struct file *file, struct address_space *mapping,
 691                 loff_t pos, unsigned len, unsigned flags,
 692                 struct page **pagep, void **fsdata)
 693 {
 694         int ret = 0;
 695         struct page *page;
 696
 697         page = *pagep;
 698         if (page == NULL) {
 699                 ret = simple_write_begin(file, mapping, pos, len, flags, pagep,
 700                                          fsdata);
 701                 if (ret) {
 702                         EXOFS_DBGMSG("simple_write_begin faild\n");
 703                         return ret;
 704                 }
 705
 706                 page = *pagep;
 707         }
 708
 709          /* read modify write */
 710         if (!PageUptodate(page) && (len != PAGE_CACHE_SIZE)) {
 711                 ret = _readpage(page, true);
 712                 if (ret) {
 713                         /*SetPageError was done by _readpage. Is it ok?*/
 714                         unlock_page(page);
 715                         EXOFS_DBGMSG("__readpage_filler faild\n");
 716                 }
 717         }
 718
 719         return ret;
 720 }
 721
 722 static int exofs_write_begin_export(struct file *file,
 723                 struct address_space *mapping,
 724                 loff_t pos, unsigned len, unsigned flags,
 725                 struct page **pagep, void **fsdata)
 726 {
 727         *pagep = NULL;
 728
 729         return exofs_write_begin(file, mapping, pos, len, flags, pagep,
 730                                         fsdata);
 731 }
 732
 733 const struct address_space_operations exofs_aops = {
 734         .readpage       = exofs_readpage,
 735         .readpages      = exofs_readpages,
 736         .writepage      = exofs_writepage,
 737         .writepages     = exofs_writepages,
 738         .write_begin    = exofs_write_begin_export,
 739         .write_end      = simple_write_end,
 740 };
 741
 742 /******************************************************************************
 743  * INODE OPERATIONS
 744  *****************************************************************************/
 745
 746 /*
 747  * Test whether an inode is a fast symlink.
 748  */
 749 static inline int exofs_inode_is_fast_symlink(struct inode *inode)
 750 {
 751         struct exofs_i_info *oi = exofs_i(inode);
 752
 753         return S_ISLNK(inode->i_mode) && (oi->i_data[0] != 0);
 754 }
 755
 756 /*
 757  * get_block_t - Fill in a buffer_head
 758  * An OSD takes care of block allocation so we just fake an allocation by
 759  * putting in the inode's sector_t in the buffer_head.
 760  * TODO: What about the case of create==0 and @iblock does not exist in the
 761  * object?
 762  */
 763 static int exofs_get_block(struct inode *inode, sector_t iblock,
 764                     struct buffer_head *bh_result, int create)
 765 {
 766         map_bh(bh_result, inode->i_sb, iblock);
 767         return 0;
 768 }
 769
 770 const struct osd_attr g_attr_logical_length = ATTR_DEF(
 771         OSD_APAGE_OBJECT_INFORMATION, OSD_ATTR_OI_LOGICAL_LENGTH, 8);
 772
 773 /*
 774  * Truncate a file to the specified size - all we have to do is set the size
 775  * attribute.  We make sure the object exists first.
 776  */
 777 void exofs_truncate(struct inode *inode)
 778 {
 779         struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
 780         struct exofs_i_info *oi = exofs_i(inode);
 781         struct osd_obj_id obj = {sbi->s_pid, inode->i_ino + EXOFS_OBJ_OFF};
 782         struct osd_request *or;
 783         struct osd_attr attr;
 784         loff_t isize = i_size_read(inode);
 785         __be64 newsize;
 786         int ret;
 787
 788         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
 789              || S_ISLNK(inode->i_mode)))
 790                 return;
 791         if (exofs_inode_is_fast_symlink(inode))
 792                 return;
 793         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 794                 return;
 795         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 796
 797         nobh_truncate_page(inode->i_mapping, isize, exofs_get_block);
 798
 799         or = osd_start_request(sbi->s_dev, GFP_KERNEL);
 800         if (unlikely(!or)) {
 801                 EXOFS_ERR("ERROR: exofs_truncate: osd_start_request failed\n");
 802                 goto fail;
 803         }
 804
 805         osd_req_set_attributes(or, &obj);
 806
 807         newsize = cpu_to_be64((u64)isize);
 808         attr = g_attr_logical_length;
 809         attr.val_ptr = &newsize;
 810         osd_req_add_set_attr_list(or, &attr, 1);
 811
 812         /* if we are about to truncate an object, and it hasn't been
 813          * created yet, wait
 814          */
 815         if (unlikely(wait_obj_created(oi)))
 816                 goto fail;
 817
 818         ret = exofs_sync_op(or, sbi->s_timeout, oi->i_cred);
 819         osd_end_request(or);
 820         if (ret)
 821                 goto fail;
 822
 823 out:
 824         mark_inode_dirty(inode);
 825         return;
 826 fail:
 827         make_bad_inode(inode);
 828         goto out;
 829 }
 830
 831 /*
 832  * Set inode attributes - just call generic functions.
 833  */
 834 int exofs_setattr(struct dentry *dentry, struct iattr *iattr)
 835 {
 836         struct inode *inode = dentry->d_inode;
 837         int error;
 838
 839         error = inode_change_ok(inode, iattr);
 840         if (error)
 841                 return error;
 842
 843         error = inode_setattr(inode, iattr);
 844         return error;
 845 }
 846
 847 /*
 848  * Read an inode from the OSD, and return it as is.  We also return the size
 849  * attribute in the 'sanity' argument if we got compiled with debugging turned
 850  * on.
 851  */
 852 static int exofs_get_inode(struct super_block *sb, struct exofs_i_info *oi,
 853                     struct exofs_fcb *inode, uint64_t *sanity)
 854 {
 855         struct exofs_sb_info *sbi = sb->s_fs_info;
 856         struct osd_request *or;
 857         struct osd_attr attr;
 858         struct osd_obj_id obj = {sbi->s_pid,
 859                                  oi->vfs_inode.i_ino + EXOFS_OBJ_OFF};
 860         int ret;
 861
 862         exofs_make_credential(oi->i_cred, &obj);
 863
 864         or = osd_start_request(sbi->s_dev, GFP_KERNEL);
 865         if (unlikely(!or)) {
 866                 EXOFS_ERR("exofs_get_inode: osd_start_request failed.\n");
 867                 return -ENOMEM;
 868         }
 869         osd_req_get_attributes(or, &obj);
 870
 871         /* we need the inode attribute */
 872         osd_req_add_get_attr_list(or, &g_attr_inode_data, 1);
 873
 874 #ifdef EXOFS_DEBUG_OBJ_ISIZE
 875         /* we get the size attributes to do a sanity check */
 876         osd_req_add_get_attr_list(or, &g_attr_logical_length, 1);
 877 #endif
 878
 879         ret = exofs_sync_op(or, sbi->s_timeout, oi->i_cred);
 880         if (ret)
 881                 goto out;
 882
 883         attr = g_attr_inode_data;
 884         ret = extract_attr_from_req(or, &attr);
 885         if (ret) {
 886                 EXOFS_ERR("exofs_get_inode: extract_attr_from_req failed\n");
 887                 goto out;
 888         }
 889
 890         WARN_ON(attr.len != EXOFS_INO_ATTR_SIZE);
 891         memcpy(inode, attr.val_ptr, EXOFS_INO_ATTR_SIZE);
 892
 893 #ifdef EXOFS_DEBUG_OBJ_ISIZE
 894         attr = g_attr_logical_length;
 895         ret = extract_attr_from_req(or, &attr);
 896         if (ret) {
 897                 EXOFS_ERR("ERROR: extract attr from or failed\n");
 898                 goto out;
 899         }
 900         *sanity = get_unaligned_be64(attr.val_ptr);
 901 #endif
 902
 903 out:
 904         osd_end_request(or);
 905         return ret;
 906 }
 907
 908 /*
 909  * Fill in an inode read from the OSD and set it up for use
 910  */
 911 struct inode *exofs_iget(struct super_block *sb, unsigned long ino)
 912 {
 913         struct exofs_i_info *oi;
 914         struct exofs_fcb fcb;
 915         struct inode *inode;
 916         uint64_t uninitialized_var(sanity);
 917         int ret;
 918
 919         inode = iget_locked(sb, ino);
 920         if (!inode)
 921                 return ERR_PTR(-ENOMEM);
 922         if (!(inode->i_state & I_NEW))
 923                 return inode;
 924         oi = exofs_i(inode);
 925
 926         /* read the inode from the osd */
 927         ret = exofs_get_inode(sb, oi, &fcb, &sanity);
 928         if (ret)
 929                 goto bad_inode;
 930
 931         init_waitqueue_head(&oi->i_wq);
 932         set_obj_created(oi);
 933
 934         /* copy stuff from on-disk struct to in-memory struct */
 935         inode->i_mode = le16_to_cpu(fcb.i_mode);
 936         inode->i_uid = le32_to_cpu(fcb.i_uid);
 937         inode->i_gid = le32_to_cpu(fcb.i_gid);
 938         inode->i_nlink = le16_to_cpu(fcb.i_links_count);
 939         inode->i_ctime.tv_sec = (signed)le32_to_cpu(fcb.i_ctime);
 940         inode->i_atime.tv_sec = (signed)le32_to_cpu(fcb.i_atime);
 941         inode->i_mtime.tv_sec = (signed)le32_to_cpu(fcb.i_mtime);
 942         inode->i_ctime.tv_nsec =
 943                 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = 0;
 944         oi->i_commit_size = le64_to_cpu(fcb.i_size);
 945         i_size_write(inode, oi->i_commit_size);
 946         inode->i_blkbits = EXOFS_BLKSHIFT;
 947         inode->i_generation = le32_to_cpu(fcb.i_generation);
 948
 949 #ifdef EXOFS_DEBUG_OBJ_ISIZE
 950         if ((inode->i_size != sanity) &&
 951                 (!exofs_inode_is_fast_symlink(inode))) {
 952                 EXOFS_ERR("WARNING: Size of object from inode and "
 953                           "attributes differ (%lld != %llu)\n",
 954                           inode->i_size, _LLU(sanity));
 955         }
 956 #endif
 957
 958         oi->i_dir_start_lookup = 0;
 959
 960         if ((inode->i_nlink == 0) && (inode->i_mode == 0)) {
 961                 ret = -ESTALE;
 962                 goto bad_inode;
 963         }
 964
 965         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
 966                 if (fcb.i_data[0])
 967                         inode->i_rdev =
 968                                 old_decode_dev(le32_to_cpu(fcb.i_data[0]));
 969                 else
 970                         inode->i_rdev =
 971                                 new_decode_dev(le32_to_cpu(fcb.i_data[1]));
 972         } else {
 973                 memcpy(oi->i_data, fcb.i_data, sizeof(fcb.i_data));
 974         }
 975
 976         if (S_ISREG(inode->i_mode)) {
 977                 inode->i_op = &exofs_file_inode_operations;
 978                 inode->i_fop = &exofs_file_operations;
 979                 inode->i_mapping->a_ops = &exofs_aops;
 980         } else if (S_ISDIR(inode->i_mode)) {
 981                 inode->i_op = &exofs_dir_inode_operations;
 982                 inode->i_fop = &exofs_dir_operations;
 983                 inode->i_mapping->a_ops = &exofs_aops;
 984         } else if (S_ISLNK(inode->i_mode)) {
 985                 if (exofs_inode_is_fast_symlink(inode))
 986                         inode->i_op = &exofs_fast_symlink_inode_operations;
 987                 else {
 988                         inode->i_op = &exofs_symlink_inode_operations;
 989                         inode->i_mapping->a_ops = &exofs_aops;
 990                 }
 991         } else {
 992                 inode->i_op = &exofs_special_inode_operations;
 993                 if (fcb.i_data[0])
 994                         init_special_inode(inode, inode->i_mode,
 995                            old_decode_dev(le32_to_cpu(fcb.i_data[0])));
 996                 else
 997                         init_special_inode(inode, inode->i_mode,
 998                            new_decode_dev(le32_to_cpu(fcb.i_data[1])));
 999         }
1000
1001         unlock_new_inode(inode);
1002         return inode;
1003
1004 bad_inode:
1005         iget_failed(inode);
1006         return ERR_PTR(ret);
1007 }
1008
1009 int __exofs_wait_obj_created(struct exofs_i_info *oi)
1010 {
1011         if (!obj_created(oi)) {
1012                 BUG_ON(!obj_2bcreated(oi));
1013                 wait_event(oi->i_wq, obj_created(oi));
1014         }
1015         return unlikely(is_bad_inode(&oi->vfs_inode)) ? -EIO : 0;
1016 }
1017 /*
1018  * Callback function from exofs_new_inode().  The important thing is that we
1019  * set the obj_created flag so that other methods know that the object exists on
1020  * the OSD.
1021  */
1022 static void create_done(struct osd_request *or, void *p)
1023 {
1024         struct inode *inode = p;
1025         struct exofs_i_info *oi = exofs_i(inode);
1026         struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
1027         int ret;
1028
1029         ret = exofs_check_ok(or);
1030         osd_end_request(or);
1031         atomic_dec(&sbi->s_curr_pending);
1032
1033         if (unlikely(ret)) {
1034                 EXOFS_ERR("object=0x%llx creation faild in pid=0x%llx",
1035                           _LLU(sbi->s_pid), _LLU(inode->i_ino + EXOFS_OBJ_OFF));
1036                 make_bad_inode(inode);
1037         } else
1038                 set_obj_created(oi);
1039
1040         atomic_dec(&inode->i_count);
1041         wake_up(&oi->i_wq);
1042 }
1043
1044 /*
1045  * Set up a new inode and create an object for it on the OSD
1046  */
1047 struct inode *exofs_new_inode(struct inode *dir, int mode)
1048 {
1049         struct super_block *sb;
1050         struct inode *inode;
1051         struct exofs_i_info *oi;
1052         struct exofs_sb_info *sbi;
1053         struct osd_request *or;
1054         struct osd_obj_id obj;
1055         int ret;
1056
1057         sb = dir->i_sb;
1058         inode = new_inode(sb);
1059         if (!inode)
1060                 return ERR_PTR(-ENOMEM);
1061
1062         oi = exofs_i(inode);
1063
1064         init_waitqueue_head(&oi->i_wq);
1065         set_obj_2bcreated(oi);
1066
1067         sbi = sb->s_fs_info;
1068
1069         sb->s_dirt = 1;
1070         inode->i_uid = current->cred->fsuid;
1071         if (dir->i_mode & S_ISGID) {
1072                 inode->i_gid = dir->i_gid;
1073                 if (S_ISDIR(mode))
1074                         mode |= S_ISGID;
1075         } else {
1076                 inode->i_gid = current->cred->fsgid;
1077         }
1078         inode->i_mode = mode;
1079
1080         inode->i_ino = sbi->s_nextid++;
1081         inode->i_blkbits = EXOFS_BLKSHIFT;
1082         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1083         oi->i_commit_size = inode->i_size = 0;
1084         spin_lock(&sbi->s_next_gen_lock);
1085         inode->i_generation = sbi->s_next_generation++;
1086         spin_unlock(&sbi->s_next_gen_lock);
1087         insert_inode_hash(inode);
1088
1089         mark_inode_dirty(inode);
1090
1091         obj.partition = sbi->s_pid;
1092         obj.id = inode->i_ino + EXOFS_OBJ_OFF;
1093         exofs_make_credential(oi->i_cred, &obj);
1094
1095         or = osd_start_request(sbi->s_dev, GFP_KERNEL);
1096         if (unlikely(!or)) {
1097                 EXOFS_ERR("exofs_new_inode: osd_start_request failed\n");
1098                 return ERR_PTR(-ENOMEM);
1099         }
1100
1101         osd_req_create_object(or, &obj);
1102
1103         /* increment the refcount so that the inode will still be around when we
1104          * reach the callback
1105          */
1106         atomic_inc(&inode->i_count);
1107
1108         ret = exofs_async_op(or, create_done, inode, oi->i_cred);
1109         if (ret) {
1110                 atomic_dec(&inode->i_count);
1111                 osd_end_request(or);
1112                 return ERR_PTR(-EIO);
1113         }
1114         atomic_inc(&sbi->s_curr_pending);
1115
1116         return inode;
1117 }
1118
1119 /*
1120  * struct to pass two arguments to update_inode's callback
1121  */
1122 struct updatei_args {
1123         struct exofs_sb_info    *sbi;
1124         struct exofs_fcb        fcb;
1125 };
1126
1127 /*
1128  * Callback function from exofs_update_inode().
1129  */
1130 static void updatei_done(struct osd_request *or, void *p)
1131 {
1132         struct updatei_args *args = p;
1133
1134         osd_end_request(or);
1135
1136         atomic_dec(&args->sbi->s_curr_pending);
1137
1138         kfree(args);
1139 }
1140
1141 /*
1142  * Write the inode to the OSD.  Just fill up the struct, and set the attribute
1143  * synchronously or asynchronously depending on the do_sync flag.
1144  */
1145 static int exofs_update_inode(struct inode *inode, int do_sync)
1146 {
1147         struct exofs_i_info *oi = exofs_i(inode);
1148         struct super_block *sb = inode->i_sb;
1149         struct exofs_sb_info *sbi = sb->s_fs_info;
1150         struct osd_obj_id obj = {sbi->s_pid, inode->i_ino + EXOFS_OBJ_OFF};
1151         struct osd_request *or;
1152         struct osd_attr attr;
1153         struct exofs_fcb *fcb;
1154         struct updatei_args *args;
1155         int ret;
1156
1157         args = kzalloc(sizeof(*args), GFP_KERNEL);
1158         if (!args)
1159                 return -ENOMEM;
1160
1161         fcb = &args->fcb;
1162
1163         fcb->i_mode = cpu_to_le16(inode->i_mode);
1164         fcb->i_uid = cpu_to_le32(inode->i_uid);
1165         fcb->i_gid = cpu_to_le32(inode->i_gid);
1166         fcb->i_links_count = cpu_to_le16(inode->i_nlink);
1167         fcb->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
1168         fcb->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
1169         fcb->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
1170         oi->i_commit_size = i_size_read(inode);
1171         fcb->i_size = cpu_to_le64(oi->i_commit_size);
1172         fcb->i_generation = cpu_to_le32(inode->i_generation);
1173
1174         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1175                 if (old_valid_dev(inode->i_rdev)) {
1176                         fcb->i_data[0] =
1177                                 cpu_to_le32(old_encode_dev(inode->i_rdev));
1178                         fcb->i_data[1] = 0;
1179                 } else {
1180                         fcb->i_data[0] = 0;
1181                         fcb->i_data[1] =
1182                                 cpu_to_le32(new_encode_dev(inode->i_rdev));
1183                         fcb->i_data[2] = 0;
1184                 }
1185         } else
1186                 memcpy(fcb->i_data, oi->i_data, sizeof(fcb->i_data));
1187
1188         or = osd_start_request(sbi->s_dev, GFP_KERNEL);
1189         if (unlikely(!or)) {
1190                 EXOFS_ERR("exofs_update_inode: osd_start_request failed.\n");
1191                 ret = -ENOMEM;
1192                 goto free_args;
1193         }
1194
1195         osd_req_set_attributes(or, &obj);
1196
1197         attr = g_attr_inode_data;
1198         attr.val_ptr = fcb;
1199         osd_req_add_set_attr_list(or, &attr, 1);
1200
1201         if (!obj_created(oi)) {
1202                 EXOFS_DBGMSG("!obj_created\n");
1203                 BUG_ON(!obj_2bcreated(oi));
1204                 wait_event(oi->i_wq, obj_created(oi));
1205                 EXOFS_DBGMSG("wait_event done\n");
1206         }
1207
1208         if (do_sync) {
1209                 ret = exofs_sync_op(or, sbi->s_timeout, oi->i_cred);
1210                 osd_end_request(or);
1211                 goto free_args;
1212         } else {
1213                 args->sbi = sbi;
1214
1215                 ret = exofs_async_op(or, updatei_done, args, oi->i_cred);
1216                 if (ret) {
1217                         osd_end_request(or);
1218                         goto free_args;
1219                 }
1220                 atomic_inc(&sbi->s_curr_pending);
1221                 goto out; /* deallocation in updatei_done */
1222         }
1223
1224 free_args:
1225         kfree(args);
1226 out:
1227         EXOFS_DBGMSG("ret=>%d\n", ret);
1228         return ret;
1229 }
1230
1231 int exofs_write_inode(struct inode *inode, int wait)
1232 {
1233         return exofs_update_inode(inode, wait);
1234 }
1235
1236 /*
1237  * Callback function from exofs_delete_inode() - don't have much cleaning up to
1238  * do.
1239  */
1240 static void delete_done(struct osd_request *or, void *p)
1241 {
1242         struct exofs_sb_info *sbi;
1243         osd_end_request(or);
1244         sbi = p;
1245         atomic_dec(&sbi->s_curr_pending);
1246 }
1247
1248 /*
1249  * Called when the refcount of an inode reaches zero.  We remove the object
1250  * from the OSD here.  We make sure the object was created before we try and
1251  * delete it.
1252  */
1253 void exofs_delete_inode(struct inode *inode)
1254 {
1255         struct exofs_i_info *oi = exofs_i(inode);
1256         struct super_block *sb = inode->i_sb;
1257         struct exofs_sb_info *sbi = sb->s_fs_info;
1258         struct osd_obj_id obj = {sbi->s_pid, inode->i_ino + EXOFS_OBJ_OFF};
1259         struct osd_request *or;
1260         int ret;
1261
1262         truncate_inode_pages(&inode->i_data, 0);
1263
1264         if (is_bad_inode(inode))
1265                 goto no_delete;
1266
1267         mark_inode_dirty(inode);
1268         exofs_update_inode(inode, inode_needs_sync(inode));
1269
1270         inode->i_size = 0;
1271         if (inode->i_blocks)
1272                 exofs_truncate(inode);
1273
1274         clear_inode(inode);
1275
1276         or = osd_start_request(sbi->s_dev, GFP_KERNEL);
1277         if (unlikely(!or)) {
1278                 EXOFS_ERR("exofs_delete_inode: osd_start_request failed\n");
1279                 return;
1280         }
1281
1282         osd_req_remove_object(or, &obj);
1283
1284         /* if we are deleting an obj that hasn't been created yet, wait */
1285         if (!obj_created(oi)) {
1286                 BUG_ON(!obj_2bcreated(oi));
1287                 wait_event(oi->i_wq, obj_created(oi));
1288         }
1289
1290         ret = exofs_async_op(or, delete_done, sbi, oi->i_cred);
1291         if (ret) {
1292                 EXOFS_ERR(
1293                        "ERROR: @exofs_delete_inode exofs_async_op failed\n");
1294                 osd_end_request(or);
1295                 return;
1296         }
1297         atomic_inc(&sbi->s_curr_pending);
1298
1299         return;
1300
1301 no_delete:
1302         clear_inode(inode);
1303 }