fs/gfs2/ops_address.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
   4  *
   5  * This copyrighted material is made available to anyone wishing to use,
   6  * modify, copy, or redistribute it subject to the terms and conditions
   7  * of the GNU General Public License v.2.
   8  */
   9
  10 #include <linux/sched.h>
  11 #include <linux/slab.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/completion.h>
  14 #include <linux/buffer_head.h>
  15 #include <linux/pagemap.h>
  16 #include <linux/mpage.h>
  17 #include <asm/semaphore.h>
  18
  19 #include "gfs2.h"
  20 #include "bmap.h"
  21 #include "glock.h"
  22 #include "inode.h"
  23 #include "log.h"
  24 #include "meta_io.h"
  25 #include "ops_address.h"
  26 #include "page.h"
  27 #include "quota.h"
  28 #include "trans.h"
  29 #include "rgrp.h"
  30
  31 /**
  32  * gfs2_get_block - Fills in a buffer head with details about a block
  33  * @inode: The inode
  34  * @lblock: The block number to look up
  35  * @bh_result: The buffer head to return the result in
  36  * @create: Non-zero if we may add block to the file
  37  *
  38  * Returns: errno
  39  */
  40
  41 int gfs2_get_block(struct inode *inode, sector_t lblock,
  42                    struct buffer_head *bh_result, int create)
  43 {
  44         struct gfs2_inode *ip = get_v2ip(inode);
  45         int new = create;
  46         uint64_t dblock;
  47         int error;
  48
  49         error = gfs2_block_map(ip, lblock, &new, &dblock, NULL);
  50         if (error)
  51                 return error;
  52
  53         if (!dblock)
  54                 return 0;
  55
  56         map_bh(bh_result, inode->i_sb, dblock);
  57         if (new)
  58                 set_buffer_new(bh_result);
  59
  60         return 0;
  61 }
  62
  63 /**
  64  * get_block_noalloc - Fills in a buffer head with details about a block
  65  * @inode: The inode
  66  * @lblock: The block number to look up
  67  * @bh_result: The buffer head to return the result in
  68  * @create: Non-zero if we may add block to the file
  69  *
  70  * Returns: errno
  71  */
  72
  73 static int get_block_noalloc(struct inode *inode, sector_t lblock,
  74                              struct buffer_head *bh_result, int create)
  75 {
  76         struct gfs2_inode *ip = get_v2ip(inode);
  77         int new = 0;
  78         uint64_t dblock;
  79         int error;
  80
  81         error = gfs2_block_map(ip, lblock, &new, &dblock, NULL);
  82         if (error)
  83                 return error;
  84
  85         if (dblock)
  86                 map_bh(bh_result, inode->i_sb, dblock);
  87         else if (gfs2_assert_withdraw(ip->i_sbd, !create))
  88                 error = -EIO;
  89
  90         return error;
  91 }
  92
  93 static int get_blocks(struct inode *inode, sector_t lblock,
  94                       unsigned long max_blocks, struct buffer_head *bh_result,
  95                       int create)
  96 {
  97         struct gfs2_inode *ip = get_v2ip(inode);
  98         int new = create;
  99         uint64_t dblock;
 100         uint32_t extlen;
 101         int error;
 102
 103         error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen);
 104         if (error)
 105                 return error;
 106
 107         if (!dblock)
 108                 return 0;
 109
 110         map_bh(bh_result, inode->i_sb, dblock);
 111         if (new)
 112                 set_buffer_new(bh_result);
 113
 114         if (extlen > max_blocks)
 115                 extlen = max_blocks;
 116         bh_result->b_size = extlen << inode->i_blkbits;
 117
 118         return 0;
 119 }
 120
 121 static int get_blocks_noalloc(struct inode *inode, sector_t lblock,
 122                               unsigned long max_blocks,
 123                               struct buffer_head *bh_result, int create)
 124 {
 125         struct gfs2_inode *ip = get_v2ip(inode);
 126         int new = 0;
 127         uint64_t dblock;
 128         uint32_t extlen;
 129         int error;
 130
 131         error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen);
 132         if (error)
 133                 return error;
 134
 135         if (dblock) {
 136                 map_bh(bh_result, inode->i_sb, dblock);
 137                 if (extlen > max_blocks)
 138                         extlen = max_blocks;
 139                 bh_result->b_size = extlen << inode->i_blkbits;
 140         } else if (gfs2_assert_withdraw(ip->i_sbd, !create))
 141                 error = -EIO;
 142
 143         return error;
 144 }
 145
 146 /**
 147  * gfs2_writepage - Write complete page
 148  * @page: Page to write
 149  *
 150  * Returns: errno
 151  *
 152  * Some of this is copied from block_write_full_page() although we still
 153  * call it to do most of the work.
 154  */
 155
 156 static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
 157 {
 158         struct inode *inode = page->mapping->host;
 159         struct gfs2_inode *ip = get_v2ip(page->mapping->host);
 160         struct gfs2_sbd *sdp = ip->i_sbd;
 161         loff_t i_size = i_size_read(inode);
 162         pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
 163         unsigned offset;
 164         int error;
 165         int done_trans = 0;
 166
 167         atomic_inc(&sdp->sd_ops_address);
 168         if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) {
 169                 unlock_page(page);
 170                 return -EIO;
 171         }
 172         if (get_transaction)
 173                 goto out_ignore;
 174
 175         /* Is the page fully outside i_size? (truncate in progress) */
 176         offset = i_size & (PAGE_CACHE_SIZE-1);
 177         if (page->index >= end_index+1 || !offset) {
 178                 page->mapping->a_ops->invalidatepage(page, 0);
 179                 unlock_page(page);
 180                 return 0; /* don't care */
 181         }
 182
 183         if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) {
 184                 error = gfs2_trans_begin(sdp, RES_DINODE + 1, 0);
 185                 if (error)
 186                         goto out_ignore;
 187                 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1);
 188                 done_trans = 1;
 189         }
 190
 191         error = block_write_full_page(page, get_block_noalloc, wbc);
 192         if (done_trans)
 193                 gfs2_trans_end(sdp);
 194         gfs2_meta_cache_flush(ip);
 195         return error;
 196
 197 out_ignore:
 198         redirty_page_for_writepage(wbc, page);
 199         unlock_page(page);
 200         return 0;
 201 }
 202
 203 /**
 204  * stuffed_readpage - Fill in a Linux page with stuffed file data
 205  * @ip: the inode
 206  * @page: the page
 207  *
 208  * Returns: errno
 209  */
 210
 211 static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
 212 {
 213         struct buffer_head *dibh;
 214         void *kaddr;
 215         int error;
 216
 217         error = gfs2_meta_inode_buffer(ip, &dibh);
 218         if (error)
 219                 return error;
 220
 221         kaddr = kmap(page);
 222         memcpy((char *)kaddr,
 223                dibh->b_data + sizeof(struct gfs2_dinode),
 224                ip->i_di.di_size);
 225         memset((char *)kaddr + ip->i_di.di_size,
 226                0,
 227                PAGE_CACHE_SIZE - ip->i_di.di_size);
 228         kunmap(page);
 229
 230         brelse(dibh);
 231
 232         SetPageUptodate(page);
 233
 234         return 0;
 235 }
 236
 237 static int zero_readpage(struct page *page)
 238 {
 239         void *kaddr;
 240
 241         kaddr = kmap(page);
 242         memset(kaddr, 0, PAGE_CACHE_SIZE);
 243         kunmap(page);
 244
 245         SetPageUptodate(page);
 246         unlock_page(page);
 247
 248         return 0;
 249 }
 250
 251 /**
 252  * gfs2_readpage - readpage with locking
 253  * @file: The file to read a page for. N.B. This may be NULL if we are
 254  * reading an internal file.
 255  * @page: The page to read
 256  *
 257  * Returns: errno
 258  */
 259
 260 static int gfs2_readpage(struct file *file, struct page *page)
 261 {
 262         struct gfs2_inode *ip = get_v2ip(page->mapping->host);
 263         struct gfs2_sbd *sdp = ip->i_sbd;
 264         struct gfs2_holder gh;
 265         int error;
 266
 267         atomic_inc(&sdp->sd_ops_address);
 268
 269         gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
 270         error = gfs2_glock_nq_m_atime(1, &gh);
 271         if (error)
 272                 goto out_unlock;
 273
 274         if (gfs2_is_stuffed(ip)) {
 275                 if (!page->index) {
 276                         error = stuffed_readpage(ip, page);
 277                         unlock_page(page);
 278                 } else
 279                         error = zero_readpage(page);
 280         } else
 281                 error = mpage_readpage(page, gfs2_get_block);
 282
 283         if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 284                 error = -EIO;
 285
 286         gfs2_glock_dq_m(1, &gh);
 287         gfs2_holder_uninit(&gh);
 288 out:
 289         return error;
 290 out_unlock:
 291         unlock_page(page);
 292         goto out;
 293 }
 294
 295 /**
 296  * gfs2_prepare_write - Prepare to write a page to a file
 297  * @file: The file to write to
 298  * @page: The page which is to be prepared for writing
 299  * @from: From (byte range within page)
 300  * @to: To (byte range within page)
 301  *
 302  * Returns: errno
 303  */
 304
 305 static int gfs2_prepare_write(struct file *file, struct page *page,
 306                               unsigned from, unsigned to)
 307 {
 308         struct gfs2_inode *ip = get_v2ip(page->mapping->host);
 309         struct gfs2_sbd *sdp = ip->i_sbd;
 310         unsigned int data_blocks, ind_blocks, rblocks;
 311         int alloc_required;
 312         int error = 0;
 313         loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + from;
 314         loff_t end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
 315         struct gfs2_alloc *al;
 316
 317         atomic_inc(&sdp->sd_ops_address);
 318
 319         gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME, &ip->i_gh);
 320         error = gfs2_glock_nq_m_atime(1, &ip->i_gh);
 321         if (error)
 322                 goto out_uninit;
 323
 324         gfs2_write_calc_reserv(ip, to - from, &data_blocks, &ind_blocks);
 325
 326         error = gfs2_write_alloc_required(ip, pos, from - to, &alloc_required);
 327         if (error)
 328                 goto out_unlock;
 329
 330
 331         if (alloc_required) {
 332                 al = gfs2_alloc_get(ip);
 333
 334                 error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
 335                 if (error)
 336                         goto out_alloc_put;
 337
 338                 error = gfs2_quota_check(ip, ip->i_di.di_uid, ip->i_di.di_gid);
 339                 if (error)
 340                         goto out_qunlock;
 341
 342                 al->al_requested = data_blocks + ind_blocks;
 343                 error = gfs2_inplace_reserve(ip);
 344                 if (error)
 345                         goto out_qunlock;
 346         }
 347
 348         rblocks = RES_DINODE + ind_blocks;
 349         if (gfs2_is_jdata(ip))
 350                 rblocks += data_blocks ? data_blocks : 1;
 351         if (ind_blocks || data_blocks)
 352                 rblocks += RES_STATFS + RES_QUOTA;
 353
 354         error = gfs2_trans_begin(sdp, rblocks, 0);
 355         if (error)
 356                 goto out;
 357
 358         if (gfs2_is_stuffed(ip)) {
 359                 if (end > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
 360                         error = gfs2_unstuff_dinode(ip, gfs2_unstuffer_page, page);
 361                         if (error)
 362                                 goto out;
 363                 } else if (!PageUptodate(page)) {
 364                         error = stuffed_readpage(ip, page);
 365                         goto out;
 366                 }
 367         }
 368
 369         error = block_prepare_write(page, from, to, gfs2_get_block);
 370
 371 out:
 372         if (error) {
 373                 gfs2_trans_end(sdp);
 374                 if (alloc_required) {
 375                         gfs2_inplace_release(ip);
 376 out_qunlock:
 377                         gfs2_quota_unlock(ip);
 378 out_alloc_put:
 379                         gfs2_alloc_put(ip);
 380                 }
 381 out_unlock:
 382                 gfs2_glock_dq_m(1, &ip->i_gh);
 383 out_uninit:
 384                 gfs2_holder_uninit(&ip->i_gh);
 385         }
 386
 387         return error;
 388 }
 389
 390 /**
 391  * gfs2_commit_write - Commit write to a file
 392  * @file: The file to write to
 393  * @page: The page containing the data
 394  * @from: From (byte range within page)
 395  * @to: To (byte range within page)
 396  *
 397  * Returns: errno
 398  */
 399
 400 static int gfs2_commit_write(struct file *file, struct page *page,
 401                              unsigned from, unsigned to)
 402 {
 403         struct inode *inode = page->mapping->host;
 404         struct gfs2_inode *ip = get_v2ip(inode);
 405         struct gfs2_sbd *sdp = ip->i_sbd;
 406         int error = -EOPNOTSUPP;
 407         struct buffer_head *dibh;
 408         struct gfs2_alloc *al = &ip->i_alloc;;
 409
 410         atomic_inc(&sdp->sd_ops_address);
 411
 412
 413         if (gfs2_assert_withdraw(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)))
 414                 goto fail_nounlock;
 415
 416         error = gfs2_meta_inode_buffer(ip, &dibh);
 417         if (error)
 418                 goto fail_endtrans;
 419
 420         gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 421
 422         if (gfs2_is_stuffed(ip)) {
 423                 uint64_t file_size;
 424                 void *kaddr;
 425
 426                 file_size = ((uint64_t)page->index << PAGE_CACHE_SHIFT) + to;
 427
 428                 kaddr = kmap_atomic(page, KM_USER0);
 429                 memcpy(dibh->b_data + sizeof(struct gfs2_dinode) + from,
 430                        (char *)kaddr + from, to - from);
 431                 kunmap_atomic(page, KM_USER0);
 432
 433                 SetPageUptodate(page);
 434
 435                 if (inode->i_size < file_size)
 436                         i_size_write(inode, file_size);
 437         } else {
 438                 if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip))
 439                         gfs2_page_add_databufs(ip, page, from, to);
 440                 error = generic_commit_write(file, page, from, to);
 441                 if (error)
 442                         goto fail;
 443         }
 444
 445         if (ip->i_di.di_size < inode->i_size)
 446                 ip->i_di.di_size = inode->i_size;
 447
 448         gfs2_dinode_out(&ip->i_di, dibh->b_data);
 449         brelse(dibh);
 450         gfs2_trans_end(sdp);
 451         if (al->al_requested) {
 452                 gfs2_inplace_release(ip);
 453                 gfs2_quota_unlock(ip);
 454                 gfs2_alloc_put(ip);
 455         }
 456         gfs2_glock_dq_m(1, &ip->i_gh);
 457         gfs2_holder_uninit(&ip->i_gh);
 458         return 0;
 459
 460 fail:
 461         brelse(dibh);
 462 fail_endtrans:
 463         gfs2_trans_end(sdp);
 464         if (al->al_requested) {
 465                 gfs2_inplace_release(ip);
 466                 gfs2_quota_unlock(ip);
 467                 gfs2_alloc_put(ip);
 468         }
 469         gfs2_glock_dq_m(1, &ip->i_gh);
 470         gfs2_holder_uninit(&ip->i_gh);
 471 fail_nounlock:
 472         ClearPageUptodate(page);
 473         return error;
 474 }
 475
 476 /**
 477  * gfs2_bmap - Block map function
 478  * @mapping: Address space info
 479  * @lblock: The block to map
 480  *
 481  * Returns: The disk address for the block or 0 on hole or error
 482  */
 483
 484 static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
 485 {
 486         struct gfs2_inode *ip = get_v2ip(mapping->host);
 487         struct gfs2_holder i_gh;
 488         sector_t dblock = 0;
 489         int error;
 490
 491         atomic_inc(&ip->i_sbd->sd_ops_address);
 492
 493         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
 494         if (error)
 495                 return 0;
 496
 497         if (!gfs2_is_stuffed(ip))
 498                 dblock = generic_block_bmap(mapping, lblock, gfs2_get_block);
 499
 500         gfs2_glock_dq_uninit(&i_gh);
 501
 502         return dblock;
 503 }
 504
 505 static void discard_buffer(struct gfs2_sbd *sdp, struct buffer_head *bh)
 506 {
 507         struct gfs2_bufdata *bd;
 508
 509         gfs2_log_lock(sdp);
 510         bd = get_v2bd(bh);
 511         if (bd) {
 512                 bd->bd_bh = NULL;
 513                 set_v2bd(bh, NULL);
 514                 gfs2_log_unlock(sdp);
 515                 brelse(bh);
 516         } else
 517                 gfs2_log_unlock(sdp);
 518
 519         lock_buffer(bh);
 520         clear_buffer_dirty(bh);
 521         bh->b_bdev = NULL;
 522         clear_buffer_mapped(bh);
 523         clear_buffer_req(bh);
 524         clear_buffer_new(bh);
 525         clear_buffer_delay(bh);
 526         unlock_buffer(bh);
 527 }
 528
 529 static int gfs2_invalidatepage(struct page *page, unsigned long offset)
 530 {
 531         struct gfs2_sbd *sdp = get_v2sdp(page->mapping->host->i_sb);
 532         struct buffer_head *head, *bh, *next;
 533         unsigned int curr_off = 0;
 534         int ret = 1;
 535
 536         BUG_ON(!PageLocked(page));
 537         if (!page_has_buffers(page))
 538                 return 1;
 539
 540         bh = head = page_buffers(page);
 541         do {
 542                 unsigned int next_off = curr_off + bh->b_size;
 543                 next = bh->b_this_page;
 544
 545                 if (offset <= curr_off)
 546                         discard_buffer(sdp, bh);
 547
 548                 curr_off = next_off;
 549                 bh = next;
 550         } while (bh != head);
 551
 552         if (!offset)
 553                 ret = try_to_release_page(page, 0);
 554
 555         return ret;
 556 }
 557
 558 static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
 559                           loff_t offset, unsigned long nr_segs)
 560 {
 561         struct file *file = iocb->ki_filp;
 562         struct inode *inode = file->f_mapping->host;
 563         struct gfs2_inode *ip = get_v2ip(inode);
 564         struct gfs2_sbd *sdp = ip->i_sbd;
 565         get_blocks_t *gb = get_blocks;
 566
 567         atomic_inc(&sdp->sd_ops_address);
 568
 569         if (gfs2_is_jdata(ip))
 570                 return -EINVAL;
 571
 572         if (rw == WRITE) {
 573                 return -EOPNOTSUPP; /* for now */
 574         } else {
 575                 if (gfs2_assert_warn(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)) ||
 576                     gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip)))
 577                         return -EINVAL;
 578         }
 579
 580         return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
 581                                   offset, nr_segs, gb, NULL);
 582 }
 583
 584 struct address_space_operations gfs2_file_aops = {
 585         .writepage = gfs2_writepage,
 586         .readpage = gfs2_readpage,
 587         .sync_page = block_sync_page,
 588         .prepare_write = gfs2_prepare_write,
 589         .commit_write = gfs2_commit_write,
 590         .bmap = gfs2_bmap,
 591         .invalidatepage = gfs2_invalidatepage,
 592         .direct_IO = gfs2_direct_IO,
 593 };
 594