fs/gfs2/aops.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   4  * Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.
   5  */
   6
   7 #include <linux/sched.h>
   8 #include <linux/slab.h>
   9 #include <linux/spinlock.h>
  10 #include <linux/completion.h>
  11 #include <linux/buffer_head.h>
  12 #include <linux/pagemap.h>
  13 #include <linux/pagevec.h>
  14 #include <linux/mpage.h>
  15 #include <linux/fs.h>
  16 #include <linux/writeback.h>
  17 #include <linux/swap.h>
  18 #include <linux/gfs2_ondisk.h>
  19 #include <linux/backing-dev.h>
  20 #include <linux/uio.h>
  21 #include <trace/events/writeback.h>
  22 #include <linux/sched/signal.h>
  23
  24 #include "gfs2.h"
  25 #include "incore.h"
  26 #include "bmap.h"
  27 #include "glock.h"
  28 #include "inode.h"
  29 #include "log.h"
  30 #include "meta_io.h"
  31 #include "quota.h"
  32 #include "trans.h"
  33 #include "rgrp.h"
  34 #include "super.h"
  35 #include "util.h"
  36 #include "glops.h"
  37 #include "aops.h"
  38
  39
  40 void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
  41                             unsigned int from, unsigned int len)
  42 {
  43         struct buffer_head *head = page_buffers(page);
  44         unsigned int bsize = head->b_size;
  45         struct buffer_head *bh;
  46         unsigned int to = from + len;
  47         unsigned int start, end;
  48
  49         for (bh = head, start = 0; bh != head || !start;
  50              bh = bh->b_this_page, start = end) {
  51                 end = start + bsize;
  52                 if (end <= from)
  53                         continue;
  54                 if (start >= to)
  55                         break;
  56                 set_buffer_uptodate(bh);
  57                 gfs2_trans_add_data(ip->i_gl, bh);
  58         }
  59 }
  60
  61 /**
  62  * gfs2_get_block_noalloc - Fills in a buffer head with details about a block
  63  * @inode: The inode
  64  * @lblock: The block number to look up
  65  * @bh_result: The buffer head to return the result in
  66  * @create: Non-zero if we may add block to the file
  67  *
  68  * Returns: errno
  69  */
  70
  71 static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock,
  72                                   struct buffer_head *bh_result, int create)
  73 {
  74         int error;
  75
  76         error = gfs2_block_map(inode, lblock, bh_result, 0);
  77         if (error)
  78                 return error;
  79         if (!buffer_mapped(bh_result))
  80                 return -EIO;
  81         return 0;
  82 }
  83
  84 /**
  85  * gfs2_writepage_common - Common bits of writepage
  86  * @page: The page to be written
  87  * @wbc: The writeback control
  88  *
  89  * Returns: 1 if writepage is ok, otherwise an error code or zero if no error.
  90  */
  91
  92 static int gfs2_writepage_common(struct page *page,
  93                                  struct writeback_control *wbc)
  94 {
  95         struct inode *inode = page->mapping->host;
  96         struct gfs2_inode *ip = GFS2_I(inode);
  97         struct gfs2_sbd *sdp = GFS2_SB(inode);
  98         loff_t i_size = i_size_read(inode);
  99         pgoff_t end_index = i_size >> PAGE_SHIFT;
 100         unsigned offset;
 101
 102         if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
 103                 goto out;
 104         if (current->journal_info)
 105                 goto redirty;
 106         /* Is the page fully outside i_size? (truncate in progress) */
 107         offset = i_size & (PAGE_SIZE-1);
 108         if (page->index > end_index || (page->index == end_index && !offset)) {
 109                 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
 110                 goto out;
 111         }
 112         return 1;
 113 redirty:
 114         redirty_page_for_writepage(wbc, page);
 115 out:
 116         unlock_page(page);
 117         return 0;
 118 }
 119
 120 /**
 121  * gfs2_writepage - Write page for writeback mappings
 122  * @page: The page
 123  * @wbc: The writeback control
 124  *
 125  */
 126
 127 static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
 128 {
 129         int ret;
 130
 131         ret = gfs2_writepage_common(page, wbc);
 132         if (ret <= 0)
 133                 return ret;
 134
 135         return nobh_writepage(page, gfs2_get_block_noalloc, wbc);
 136 }
 137
 138 /* This is the same as calling block_write_full_page, but it also
 139  * writes pages outside of i_size
 140  */
 141 static int gfs2_write_full_page(struct page *page, get_block_t *get_block,
 142                                 struct writeback_control *wbc)
 143 {
 144         struct inode * const inode = page->mapping->host;
 145         loff_t i_size = i_size_read(inode);
 146         const pgoff_t end_index = i_size >> PAGE_SHIFT;
 147         unsigned offset;
 148
 149         /*
 150          * The page straddles i_size.  It must be zeroed out on each and every
 151          * writepage invocation because it may be mmapped.  "A file is mapped
 152          * in multiples of the page size.  For a file that is not a multiple of
 153          * the  page size, the remaining memory is zeroed when mapped, and
 154          * writes to that region are not written out to the file."
 155          */
 156         offset = i_size & (PAGE_SIZE-1);
 157         if (page->index == end_index && offset)
 158                 zero_user_segment(page, offset, PAGE_SIZE);
 159
 160         return __block_write_full_page(inode, page, get_block, wbc,
 161                                        end_buffer_async_write);
 162 }
 163
 164 /**
 165  * __gfs2_jdata_writepage - The core of jdata writepage
 166  * @page: The page to write
 167  * @wbc: The writeback control
 168  *
 169  * This is shared between writepage and writepages and implements the
 170  * core of the writepage operation. If a transaction is required then
 171  * PageChecked will have been set and the transaction will have
 172  * already been started before this is called.
 173  */
 174
 175 static int __gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
 176 {
 177         struct inode *inode = page->mapping->host;
 178         struct gfs2_inode *ip = GFS2_I(inode);
 179         struct gfs2_sbd *sdp = GFS2_SB(inode);
 180
 181         if (PageChecked(page)) {
 182                 ClearPageChecked(page);
 183                 if (!page_has_buffers(page)) {
 184                         create_empty_buffers(page, inode->i_sb->s_blocksize,
 185                                              BIT(BH_Dirty)|BIT(BH_Uptodate));
 186                 }
 187                 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize);
 188         }
 189         return gfs2_write_full_page(page, gfs2_get_block_noalloc, wbc);
 190 }
 191
 192 /**
 193  * gfs2_jdata_writepage - Write complete page
 194  * @page: Page to write
 195  * @wbc: The writeback control
 196  *
 197  * Returns: errno
 198  *
 199  */
 200
 201 static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
 202 {
 203         struct inode *inode = page->mapping->host;
 204         struct gfs2_inode *ip = GFS2_I(inode);
 205         struct gfs2_sbd *sdp = GFS2_SB(inode);
 206         int ret;
 207
 208         if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
 209                 goto out;
 210         if (PageChecked(page) || current->journal_info)
 211                 goto out_ignore;
 212         ret = __gfs2_jdata_writepage(page, wbc);
 213         return ret;
 214
 215 out_ignore:
 216         redirty_page_for_writepage(wbc, page);
 217 out:
 218         unlock_page(page);
 219         return 0;
 220 }
 221
 222 /**
 223  * gfs2_writepages - Write a bunch of dirty pages back to disk
 224  * @mapping: The mapping to write
 225  * @wbc: Write-back control
 226  *
 227  * Used for both ordered and writeback modes.
 228  */
 229 static int gfs2_writepages(struct address_space *mapping,
 230                            struct writeback_control *wbc)
 231 {
 232         struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
 233         int ret = mpage_writepages(mapping, wbc, gfs2_get_block_noalloc);
 234
 235         /*
 236          * Even if we didn't write any pages here, we might still be holding
 237          * dirty pages in the ail. We forcibly flush the ail because we don't
 238          * want balance_dirty_pages() to loop indefinitely trying to write out
 239          * pages held in the ail that it can't find.
 240          */
 241         if (ret == 0)
 242                 set_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags);
 243
 244         return ret;
 245 }
 246
 247 /**
 248  * gfs2_write_jdata_pagevec - Write back a pagevec's worth of pages
 249  * @mapping: The mapping
 250  * @wbc: The writeback control
 251  * @pvec: The vector of pages
 252  * @nr_pages: The number of pages to write
 253  * @done_index: Page index
 254  *
 255  * Returns: non-zero if loop should terminate, zero otherwise
 256  */
 257
 258 static int gfs2_write_jdata_pagevec(struct address_space *mapping,
 259                                     struct writeback_control *wbc,
 260                                     struct pagevec *pvec,
 261                                     int nr_pages,
 262                                     pgoff_t *done_index)
 263 {
 264         struct inode *inode = mapping->host;
 265         struct gfs2_sbd *sdp = GFS2_SB(inode);
 266         unsigned nrblocks = nr_pages * (PAGE_SIZE/inode->i_sb->s_blocksize);
 267         int i;
 268         int ret;
 269
 270         ret = gfs2_trans_begin(sdp, nrblocks, nrblocks);
 271         if (ret < 0)
 272                 return ret;
 273
 274         for(i = 0; i < nr_pages; i++) {
 275                 struct page *page = pvec->pages[i];
 276
 277                 *done_index = page->index;
 278
 279                 lock_page(page);
 280
 281                 if (unlikely(page->mapping != mapping)) {
 282 continue_unlock:
 283                         unlock_page(page);
 284                         continue;
 285                 }
 286
 287                 if (!PageDirty(page)) {
 288                         /* someone wrote it for us */
 289                         goto continue_unlock;
 290                 }
 291
 292                 if (PageWriteback(page)) {
 293                         if (wbc->sync_mode != WB_SYNC_NONE)
 294                                 wait_on_page_writeback(page);
 295                         else
 296                                 goto continue_unlock;
 297                 }
 298
 299                 BUG_ON(PageWriteback(page));
 300                 if (!clear_page_dirty_for_io(page))
 301                         goto continue_unlock;
 302
 303                 trace_wbc_writepage(wbc, inode_to_bdi(inode));
 304
 305                 ret = __gfs2_jdata_writepage(page, wbc);
 306                 if (unlikely(ret)) {
 307                         if (ret == AOP_WRITEPAGE_ACTIVATE) {
 308                                 unlock_page(page);
 309                                 ret = 0;
 310                         } else {
 311
 312                                 /*
 313                                  * done_index is set past this page,
 314                                  * so media errors will not choke
 315                                  * background writeout for the entire
 316                                  * file. This has consequences for
 317                                  * range_cyclic semantics (ie. it may
 318                                  * not be suitable for data integrity
 319                                  * writeout).
 320                                  */
 321                                 *done_index = page->index + 1;
 322                                 ret = 1;
 323                                 break;
 324                         }
 325                 }
 326
 327                 /*
 328                  * We stop writing back only if we are not doing
 329                  * integrity sync. In case of integrity sync we have to
 330                  * keep going until we have written all the pages
 331                  * we tagged for writeback prior to entering this loop.
 332                  */
 333                 if (--wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE) {
 334                         ret = 1;
 335                         break;
 336                 }
 337
 338         }
 339         gfs2_trans_end(sdp);
 340         return ret;
 341 }
 342
 343 /**
 344  * gfs2_write_cache_jdata - Like write_cache_pages but different
 345  * @mapping: The mapping to write
 346  * @wbc: The writeback control
 347  *
 348  * The reason that we use our own function here is that we need to
 349  * start transactions before we grab page locks. This allows us
 350  * to get the ordering right.
 351  */
 352
 353 static int gfs2_write_cache_jdata(struct address_space *mapping,
 354                                   struct writeback_control *wbc)
 355 {
 356         int ret = 0;
 357         int done = 0;
 358         struct pagevec pvec;
 359         int nr_pages;
 360         pgoff_t uninitialized_var(writeback_index);
 361         pgoff_t index;
 362         pgoff_t end;
 363         pgoff_t done_index;
 364         int cycled;
 365         int range_whole = 0;
 366         xa_mark_t tag;
 367
 368         pagevec_init(&pvec);
 369         if (wbc->range_cyclic) {
 370                 writeback_index = mapping->writeback_index; /* prev offset */
 371                 index = writeback_index;
 372                 if (index == 0)
 373                         cycled = 1;
 374                 else
 375                         cycled = 0;
 376                 end = -1;
 377         } else {
 378                 index = wbc->range_start >> PAGE_SHIFT;
 379                 end = wbc->range_end >> PAGE_SHIFT;
 380                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
 381                         range_whole = 1;
 382                 cycled = 1; /* ignore range_cyclic tests */
 383         }
 384         if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
 385                 tag = PAGECACHE_TAG_TOWRITE;
 386         else
 387                 tag = PAGECACHE_TAG_DIRTY;
 388
 389 retry:
 390         if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
 391                 tag_pages_for_writeback(mapping, index, end);
 392         done_index = index;
 393         while (!done && (index <= end)) {
 394                 nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end,
 395                                 tag);
 396                 if (nr_pages == 0)
 397                         break;
 398
 399                 ret = gfs2_write_jdata_pagevec(mapping, wbc, &pvec, nr_pages, &done_index);
 400                 if (ret)
 401                         done = 1;
 402                 if (ret > 0)
 403                         ret = 0;
 404                 pagevec_release(&pvec);
 405                 cond_resched();
 406         }
 407
 408         if (!cycled && !done) {
 409                 /*
 410                  * range_cyclic:
 411                  * We hit the last page and there is more work to be done: wrap
 412                  * back to the start of the file
 413                  */
 414                 cycled = 1;
 415                 index = 0;
 416                 end = writeback_index - 1;
 417                 goto retry;
 418         }
 419
 420         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
 421                 mapping->writeback_index = done_index;
 422
 423         return ret;
 424 }
 425
 426
 427 /**
 428  * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk
 429  * @mapping: The mapping to write
 430  * @wbc: The writeback control
 431  *
 432  */
 433
 434 static int gfs2_jdata_writepages(struct address_space *mapping,
 435                                  struct writeback_control *wbc)
 436 {
 437         struct gfs2_inode *ip = GFS2_I(mapping->host);
 438         struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
 439         int ret;
 440
 441         ret = gfs2_write_cache_jdata(mapping, wbc);
 442         if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
 443                 gfs2_log_flush(sdp, ip->i_gl, GFS2_LOG_HEAD_FLUSH_NORMAL |
 444                                GFS2_LFC_JDATA_WPAGES);
 445                 ret = gfs2_write_cache_jdata(mapping, wbc);
 446         }
 447         return ret;
 448 }
 449
 450 /**
 451  * stuffed_readpage - Fill in a Linux page with stuffed file data
 452  * @ip: the inode
 453  * @page: the page
 454  *
 455  * Returns: errno
 456  */
 457
 458 int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
 459 {
 460         struct buffer_head *dibh;
 461         u64 dsize = i_size_read(&ip->i_inode);
 462         void *kaddr;
 463         int error;
 464
 465         /*
 466          * Due to the order of unstuffing files and ->fault(), we can be
 467          * asked for a zero page in the case of a stuffed file being extended,
 468          * so we need to supply one here. It doesn't happen often.
 469          */
 470         if (unlikely(page->index)) {
 471                 zero_user(page, 0, PAGE_SIZE);
 472                 SetPageUptodate(page);
 473                 return 0;
 474         }
 475
 476         error = gfs2_meta_inode_buffer(ip, &dibh);
 477         if (error)
 478                 return error;
 479
 480         kaddr = kmap_atomic(page);
 481         if (dsize > gfs2_max_stuffed_size(ip))
 482                 dsize = gfs2_max_stuffed_size(ip);
 483         memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
 484         memset(kaddr + dsize, 0, PAGE_SIZE - dsize);
 485         kunmap_atomic(kaddr);
 486         flush_dcache_page(page);
 487         brelse(dibh);
 488         SetPageUptodate(page);
 489
 490         return 0;
 491 }
 492
 493
 494 /**
 495  * __gfs2_readpage - readpage
 496  * @file: The file to read a page for
 497  * @page: The page to read
 498  *
 499  * This is the core of gfs2's readpage. It's used by the internal file
 500  * reading code as in that case we already hold the glock. Also it's
 501  * called by gfs2_readpage() once the required lock has been granted.
 502  */
 503
 504 static int __gfs2_readpage(void *file, struct page *page)
 505 {
 506         struct gfs2_inode *ip = GFS2_I(page->mapping->host);
 507         struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
 508
 509         int error;
 510
 511         if (i_blocksize(page->mapping->host) == PAGE_SIZE &&
 512             !page_has_buffers(page)) {
 513                 error = iomap_readpage(page, &gfs2_iomap_ops);
 514         } else if (gfs2_is_stuffed(ip)) {
 515                 error = stuffed_readpage(ip, page);
 516                 unlock_page(page);
 517         } else {
 518                 error = mpage_readpage(page, gfs2_block_map);
 519         }
 520
 521         if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 522                 return -EIO;
 523
 524         return error;
 525 }
 526
 527 /**
 528  * gfs2_readpage - read a page of a file
 529  * @file: The file to read
 530  * @page: The page of the file
 531  *
 532  * This deals with the locking required. We have to unlock and
 533  * relock the page in order to get the locking in the right
 534  * order.
 535  */
 536
 537 static int gfs2_readpage(struct file *file, struct page *page)
 538 {
 539         struct address_space *mapping = page->mapping;
 540         struct gfs2_inode *ip = GFS2_I(mapping->host);
 541         struct gfs2_holder gh;
 542         int error;
 543
 544         unlock_page(page);
 545         gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
 546         error = gfs2_glock_nq(&gh);
 547         if (unlikely(error))
 548                 goto out;
 549         error = AOP_TRUNCATED_PAGE;
 550         lock_page(page);
 551         if (page->mapping == mapping && !PageUptodate(page))
 552                 error = __gfs2_readpage(file, page);
 553         else
 554                 unlock_page(page);
 555         gfs2_glock_dq(&gh);
 556 out:
 557         gfs2_holder_uninit(&gh);
 558         if (error && error != AOP_TRUNCATED_PAGE)
 559                 lock_page(page);
 560         return error;
 561 }
 562
 563 /**
 564  * gfs2_internal_read - read an internal file
 565  * @ip: The gfs2 inode
 566  * @buf: The buffer to fill
 567  * @pos: The file position
 568  * @size: The amount to read
 569  *
 570  */
 571
 572 int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
 573                        unsigned size)
 574 {
 575         struct address_space *mapping = ip->i_inode.i_mapping;
 576         unsigned long index = *pos / PAGE_SIZE;
 577         unsigned offset = *pos & (PAGE_SIZE - 1);
 578         unsigned copied = 0;
 579         unsigned amt;
 580         struct page *page;
 581         void *p;
 582
 583         do {
 584                 amt = size - copied;
 585                 if (offset + size > PAGE_SIZE)
 586                         amt = PAGE_SIZE - offset;
 587                 page = read_cache_page(mapping, index, __gfs2_readpage, NULL);
 588                 if (IS_ERR(page))
 589                         return PTR_ERR(page);
 590                 p = kmap_atomic(page);
 591                 memcpy(buf + copied, p + offset, amt);
 592                 kunmap_atomic(p);
 593                 put_page(page);
 594                 copied += amt;
 595                 index++;
 596                 offset = 0;
 597         } while(copied < size);
 598         (*pos) += size;
 599         return size;
 600 }
 601
 602 /**
 603  * gfs2_readpages - Read a bunch of pages at once
 604  * @file: The file to read from
 605  * @mapping: Address space info
 606  * @pages: List of pages to read
 607  * @nr_pages: Number of pages to read
 608  *
 609  * Some notes:
 610  * 1. This is only for readahead, so we can simply ignore any things
 611  *    which are slightly inconvenient (such as locking conflicts between
 612  *    the page lock and the glock) and return having done no I/O. Its
 613  *    obviously not something we'd want to do on too regular a basis.
 614  *    Any I/O we ignore at this time will be done via readpage later.
 615  * 2. We don't handle stuffed files here we let readpage do the honours.
 616  * 3. mpage_readpages() does most of the heavy lifting in the common case.
 617  * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places.
 618  */
 619
 620 static int gfs2_readpages(struct file *file, struct address_space *mapping,
 621                           struct list_head *pages, unsigned nr_pages)
 622 {
 623         struct inode *inode = mapping->host;
 624         struct gfs2_inode *ip = GFS2_I(inode);
 625         struct gfs2_sbd *sdp = GFS2_SB(inode);
 626         struct gfs2_holder gh;
 627         int ret;
 628
 629         gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
 630         ret = gfs2_glock_nq(&gh);
 631         if (unlikely(ret))
 632                 goto out_uninit;
 633         if (!gfs2_is_stuffed(ip))
 634                 ret = mpage_readpages(mapping, pages, nr_pages, gfs2_block_map);
 635         gfs2_glock_dq(&gh);
 636 out_uninit:
 637         gfs2_holder_uninit(&gh);
 638         if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 639                 ret = -EIO;
 640         return ret;
 641 }
 642
 643 /**
 644  * adjust_fs_space - Adjusts the free space available due to gfs2_grow
 645  * @inode: the rindex inode
 646  */
 647 void adjust_fs_space(struct inode *inode)
 648 {
 649         struct gfs2_sbd *sdp = GFS2_SB(inode);
 650         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
 651         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
 652         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
 653         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 654         struct buffer_head *m_bh, *l_bh;
 655         u64 fs_total, new_free;
 656
 657         if (gfs2_trans_begin(sdp, 2 * RES_STATFS, 0) != 0)
 658                 return;
 659
 660         /* Total up the file system space, according to the latest rindex. */
 661         fs_total = gfs2_ri_total(sdp);
 662         if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0)
 663                 goto out;
 664
 665         spin_lock(&sdp->sd_statfs_spin);
 666         gfs2_statfs_change_in(m_sc, m_bh->b_data +
 667                               sizeof(struct gfs2_dinode));
 668         if (fs_total > (m_sc->sc_total + l_sc->sc_total))
 669                 new_free = fs_total - (m_sc->sc_total + l_sc->sc_total);
 670         else
 671                 new_free = 0;
 672         spin_unlock(&sdp->sd_statfs_spin);
 673         fs_warn(sdp, "File system extended by %llu blocks.\n",
 674                 (unsigned long long)new_free);
 675         gfs2_statfs_change(sdp, new_free, new_free, 0);
 676
 677         if (gfs2_meta_inode_buffer(l_ip, &l_bh) != 0)
 678                 goto out2;
 679         update_statfs(sdp, m_bh, l_bh);
 680         brelse(l_bh);
 681 out2:
 682         brelse(m_bh);
 683 out:
 684         sdp->sd_rindex_uptodate = 0;
 685         gfs2_trans_end(sdp);
 686 }
 687
 688 /**
 689  * gfs2_stuffed_write_end - Write end for stuffed files
 690  * @inode: The inode
 691  * @dibh: The buffer_head containing the on-disk inode
 692  * @pos: The file position
 693  * @copied: How much was actually copied by the VFS
 694  * @page: The page
 695  *
 696  * This copies the data from the page into the inode block after
 697  * the inode data structure itself.
 698  *
 699  * Returns: copied bytes or errno
 700  */
 701 int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh,
 702                            loff_t pos, unsigned copied,
 703                            struct page *page)
 704 {
 705         struct gfs2_inode *ip = GFS2_I(inode);
 706         u64 to = pos + copied;
 707         void *kaddr;
 708         unsigned char *buf = dibh->b_data + sizeof(struct gfs2_dinode);
 709
 710         BUG_ON(pos + copied > gfs2_max_stuffed_size(ip));
 711
 712         kaddr = kmap_atomic(page);
 713         memcpy(buf + pos, kaddr + pos, copied);
 714         flush_dcache_page(page);
 715         kunmap_atomic(kaddr);
 716
 717         WARN_ON(!PageUptodate(page));
 718         unlock_page(page);
 719         put_page(page);
 720
 721         if (copied) {
 722                 if (inode->i_size < to)
 723                         i_size_write(inode, to);
 724                 mark_inode_dirty(inode);
 725         }
 726         return copied;
 727 }
 728
 729 /**
 730  * jdata_set_page_dirty - Page dirtying function
 731  * @page: The page to dirty
 732  *
 733  * Returns: 1 if it dirtyed the page, or 0 otherwise
 734  */
 735
 736 static int jdata_set_page_dirty(struct page *page)
 737 {
 738         SetPageChecked(page);
 739         return __set_page_dirty_buffers(page);
 740 }
 741
 742 /**
 743  * gfs2_bmap - Block map function
 744  * @mapping: Address space info
 745  * @lblock: The block to map
 746  *
 747  * Returns: The disk address for the block or 0 on hole or error
 748  */
 749
 750 static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
 751 {
 752         struct gfs2_inode *ip = GFS2_I(mapping->host);
 753         struct gfs2_holder i_gh;
 754         sector_t dblock = 0;
 755         int error;
 756
 757         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
 758         if (error)
 759                 return 0;
 760
 761         if (!gfs2_is_stuffed(ip))
 762                 dblock = generic_block_bmap(mapping, lblock, gfs2_block_map);
 763
 764         gfs2_glock_dq_uninit(&i_gh);
 765
 766         return dblock;
 767 }
 768
 769 static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
 770 {
 771         struct gfs2_bufdata *bd;
 772
 773         lock_buffer(bh);
 774         gfs2_log_lock(sdp);
 775         clear_buffer_dirty(bh);
 776         bd = bh->b_private;
 777         if (bd) {
 778                 if (!list_empty(&bd->bd_list) && !buffer_pinned(bh))
 779                         list_del_init(&bd->bd_list);
 780                 else
 781                         gfs2_remove_from_journal(bh, REMOVE_JDATA);
 782         }
 783         bh->b_bdev = NULL;
 784         clear_buffer_mapped(bh);
 785         clear_buffer_req(bh);
 786         clear_buffer_new(bh);
 787         gfs2_log_unlock(sdp);
 788         unlock_buffer(bh);
 789 }
 790
 791 static void gfs2_invalidatepage(struct page *page, unsigned int offset,
 792                                 unsigned int length)
 793 {
 794         struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
 795         unsigned int stop = offset + length;
 796         int partial_page = (offset || length < PAGE_SIZE);
 797         struct buffer_head *bh, *head;
 798         unsigned long pos = 0;
 799
 800         BUG_ON(!PageLocked(page));
 801         if (!partial_page)
 802                 ClearPageChecked(page);
 803         if (!page_has_buffers(page))
 804                 goto out;
 805
 806         bh = head = page_buffers(page);
 807         do {
 808                 if (pos + bh->b_size > stop)
 809                         return;
 810
 811                 if (offset <= pos)
 812                         gfs2_discard(sdp, bh);
 813                 pos += bh->b_size;
 814                 bh = bh->b_this_page;
 815         } while (bh != head);
 816 out:
 817         if (!partial_page)
 818                 try_to_release_page(page, 0);
 819 }
 820
 821 /**
 822  * gfs2_releasepage - free the metadata associated with a page
 823  * @page: the page that's being released
 824  * @gfp_mask: passed from Linux VFS, ignored by us
 825  *
 826  * Calls try_to_free_buffers() to free the buffers and put the page if the
 827  * buffers can be released.
 828  *
 829  * Returns: 1 if the page was put or else 0
 830  */
 831
 832 int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
 833 {
 834         struct address_space *mapping = page->mapping;
 835         struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
 836         struct buffer_head *bh, *head;
 837         struct gfs2_bufdata *bd;
 838
 839         if (!page_has_buffers(page))
 840                 return 0;
 841
 842         /*
 843          * From xfs_vm_releasepage: mm accommodates an old ext3 case where
 844          * clean pages might not have had the dirty bit cleared.  Thus, it can
 845          * send actual dirty pages to ->releasepage() via shrink_active_list().
 846          *
 847          * As a workaround, we skip pages that contain dirty buffers below.
 848          * Once ->releasepage isn't called on dirty pages anymore, we can warn
 849          * on dirty buffers like we used to here again.
 850          */
 851
 852         gfs2_log_lock(sdp);
 853         spin_lock(&sdp->sd_ail_lock);
 854         head = bh = page_buffers(page);
 855         do {
 856                 if (atomic_read(&bh->b_count))
 857                         goto cannot_release;
 858                 bd = bh->b_private;
 859                 if (bd && bd->bd_tr)
 860                         goto cannot_release;
 861                 if (buffer_dirty(bh) || WARN_ON(buffer_pinned(bh)))
 862                         goto cannot_release;
 863                 bh = bh->b_this_page;
 864         } while(bh != head);
 865         spin_unlock(&sdp->sd_ail_lock);
 866
 867         head = bh = page_buffers(page);
 868         do {
 869                 bd = bh->b_private;
 870                 if (bd) {
 871                         gfs2_assert_warn(sdp, bd->bd_bh == bh);
 872                         if (!list_empty(&bd->bd_list))
 873                                 list_del_init(&bd->bd_list);
 874                         bd->bd_bh = NULL;
 875                         bh->b_private = NULL;
 876                         kmem_cache_free(gfs2_bufdata_cachep, bd);
 877                 }
 878
 879                 bh = bh->b_this_page;
 880         } while (bh != head);
 881         gfs2_log_unlock(sdp);
 882
 883         return try_to_free_buffers(page);
 884
 885 cannot_release:
 886         spin_unlock(&sdp->sd_ail_lock);
 887         gfs2_log_unlock(sdp);
 888         return 0;
 889 }
 890
 891 static const struct address_space_operations gfs2_writeback_aops = {
 892         .writepage = gfs2_writepage,
 893         .writepages = gfs2_writepages,
 894         .readpage = gfs2_readpage,
 895         .readpages = gfs2_readpages,
 896         .bmap = gfs2_bmap,
 897         .invalidatepage = gfs2_invalidatepage,
 898         .releasepage = gfs2_releasepage,
 899         .direct_IO = noop_direct_IO,
 900         .migratepage = buffer_migrate_page,
 901         .is_partially_uptodate = block_is_partially_uptodate,
 902         .error_remove_page = generic_error_remove_page,
 903 };
 904
 905 static const struct address_space_operations gfs2_ordered_aops = {
 906         .writepage = gfs2_writepage,
 907         .writepages = gfs2_writepages,
 908         .readpage = gfs2_readpage,
 909         .readpages = gfs2_readpages,
 910         .set_page_dirty = __set_page_dirty_buffers,
 911         .bmap = gfs2_bmap,
 912         .invalidatepage = gfs2_invalidatepage,
 913         .releasepage = gfs2_releasepage,
 914         .direct_IO = noop_direct_IO,
 915         .migratepage = buffer_migrate_page,
 916         .is_partially_uptodate = block_is_partially_uptodate,
 917         .error_remove_page = generic_error_remove_page,
 918 };
 919
 920 static const struct address_space_operations gfs2_jdata_aops = {
 921         .writepage = gfs2_jdata_writepage,
 922         .writepages = gfs2_jdata_writepages,
 923         .readpage = gfs2_readpage,
 924         .readpages = gfs2_readpages,
 925         .set_page_dirty = jdata_set_page_dirty,
 926         .bmap = gfs2_bmap,
 927         .invalidatepage = gfs2_invalidatepage,
 928         .releasepage = gfs2_releasepage,
 929         .is_partially_uptodate = block_is_partially_uptodate,
 930         .error_remove_page = generic_error_remove_page,
 931 };
 932
 933 void gfs2_set_aops(struct inode *inode)
 934 {
 935         struct gfs2_inode *ip = GFS2_I(inode);
 936         struct gfs2_sbd *sdp = GFS2_SB(inode);
 937
 938         if (gfs2_is_jdata(ip))
 939                 inode->i_mapping->a_ops = &gfs2_jdata_aops;
 940         else if (gfs2_is_writeback(sdp))
 941                 inode->i_mapping->a_ops = &gfs2_writeback_aops;
 942         else if (gfs2_is_ordered(sdp))
 943                 inode->i_mapping->a_ops = &gfs2_ordered_aops;
 944         else
 945                 BUG();
 946 }