release/src-rt-6.x/linux/linux-2.6/fs/ufs/truncate.c

   1 /*
   2  *  linux/fs/ufs/truncate.c
   3  *
   4  * Copyright (C) 1998
   5  * Daniel Pirkl <daniel.pirkl@email.cz>
   6  * Charles University, Faculty of Mathematics and Physics
   7  *
   8  *  from
   9  *
  10  *  linux/fs/ext2/truncate.c
  11  *
  12  * Copyright (C) 1992, 1993, 1994, 1995
  13  * Remy Card (card@masi.ibp.fr)
  14  * Laboratoire MASI - Institut Blaise Pascal
  15  * Universite Pierre et Marie Curie (Paris VI)
  16  *
  17  *  from
  18  *
  19  *  linux/fs/minix/truncate.c
  20  *
  21  *  Copyright (C) 1991, 1992  Linus Torvalds
  22  *
  23  *  Big-endian to little-endian byte-swapping/bitmaps by
  24  *        David S. Miller (davem@caip.rutgers.edu), 1995
  25  */
  26
  27 /*
  28  * Real random numbers for secure rm added 94/02/18
  29  * Idea from Pierre del Perugia <delperug@gla.ecoledoc.ibp.fr>
  30  */
  31
  32 /*
  33  * Adoptation to use page cache and UFS2 write support by
  34  * Evgeniy Dushistov <dushistov@mail.ru>, 2006-2007
  35  */
  36
  37 #include <linux/errno.h>
  38 #include <linux/fs.h>
  39 #include <linux/ufs_fs.h>
  40 #include <linux/fcntl.h>
  41 #include <linux/time.h>
  42 #include <linux/stat.h>
  43 #include <linux/string.h>
  44 #include <linux/smp_lock.h>
  45 #include <linux/buffer_head.h>
  46 #include <linux/blkdev.h>
  47 #include <linux/sched.h>
  48
  49 #include "swab.h"
  50 #include "util.h"
  51
  52 /*
  53  * Secure deletion currently doesn't work. It interacts very badly
  54  * with buffers shared with memory mappings, and for that reason
  55  * can't be done in the truncate() routines. It should instead be
  56  * done separately in "release()" before calling the truncate routines
  57  * that will release the actual file blocks.
  58  *
  59  *              Linus
  60  */
  61
  62 #define DIRECT_BLOCK ((inode->i_size + uspi->s_bsize - 1) >> uspi->s_bshift)
  63 #define DIRECT_FRAGMENT ((inode->i_size + uspi->s_fsize - 1) >> uspi->s_fshift)
  64
  65
  66 static int ufs_trunc_direct(struct inode *inode)
  67 {
  68         struct ufs_inode_info *ufsi = UFS_I(inode);
  69         struct super_block * sb;
  70         struct ufs_sb_private_info * uspi;
  71         void *p;
  72         u64 frag1, frag2, frag3, frag4, block1, block2;
  73         unsigned frag_to_free, free_count;
  74         unsigned i, tmp;
  75         int retry;
  76
  77         UFSD("ENTER: ino %lu\n", inode->i_ino);
  78
  79         sb = inode->i_sb;
  80         uspi = UFS_SB(sb)->s_uspi;
  81
  82         frag_to_free = 0;
  83         free_count = 0;
  84         retry = 0;
  85
  86         frag1 = DIRECT_FRAGMENT;
  87         frag4 = min_t(u32, UFS_NDIR_FRAGMENT, ufsi->i_lastfrag);
  88         frag2 = ((frag1 & uspi->s_fpbmask) ? ((frag1 | uspi->s_fpbmask) + 1) : frag1);
  89         frag3 = frag4 & ~uspi->s_fpbmask;
  90         block1 = block2 = 0;
  91         if (frag2 > frag3) {
  92                 frag2 = frag4;
  93                 frag3 = frag4 = 0;
  94         } else if (frag2 < frag3) {
  95                 block1 = ufs_fragstoblks (frag2);
  96                 block2 = ufs_fragstoblks (frag3);
  97         }
  98
  99         UFSD("ino %lu, frag1 %llu, frag2 %llu, block1 %llu, block2 %llu,"
 100              " frag3 %llu, frag4 %llu\n", inode->i_ino,
 101              (unsigned long long)frag1, (unsigned long long)frag2,
 102              (unsigned long long)block1, (unsigned long long)block2,
 103              (unsigned long long)frag3, (unsigned long long)frag4);
 104
 105         if (frag1 >= frag2)
 106                 goto next1;
 107
 108         /*
 109          * Free first free fragments
 110          */
 111         p = ufs_get_direct_data_ptr(uspi, ufsi, ufs_fragstoblks(frag1));
 112         tmp = ufs_data_ptr_to_cpu(sb, p);
 113         if (!tmp )
 114                 ufs_panic (sb, "ufs_trunc_direct", "internal error");
 115         frag2 -= frag1;
 116         frag1 = ufs_fragnum (frag1);
 117
 118         ufs_free_fragments(inode, tmp + frag1, frag2);
 119         mark_inode_dirty(inode);
 120         frag_to_free = tmp + frag1;
 121
 122 next1:
 123         /*
 124          * Free whole blocks
 125          */
 126         for (i = block1 ; i < block2; i++) {
 127                 p = ufs_get_direct_data_ptr(uspi, ufsi, i);
 128                 tmp = ufs_data_ptr_to_cpu(sb, p);
 129                 if (!tmp)
 130                         continue;
 131                 ufs_data_ptr_clear(uspi, p);
 132
 133                 if (free_count == 0) {
 134                         frag_to_free = tmp;
 135                         free_count = uspi->s_fpb;
 136                 } else if (free_count > 0 && frag_to_free == tmp - free_count)
 137                         free_count += uspi->s_fpb;
 138                 else {
 139                         ufs_free_blocks (inode, frag_to_free, free_count);
 140                         frag_to_free = tmp;
 141                         free_count = uspi->s_fpb;
 142                 }
 143                 mark_inode_dirty(inode);
 144         }
 145
 146         if (free_count > 0)
 147                 ufs_free_blocks (inode, frag_to_free, free_count);
 148
 149         if (frag3 >= frag4)
 150                 goto next3;
 151
 152         /*
 153          * Free last free fragments
 154          */
 155         p = ufs_get_direct_data_ptr(uspi, ufsi, ufs_fragstoblks(frag3));
 156         tmp = ufs_data_ptr_to_cpu(sb, p);
 157         if (!tmp )
 158                 ufs_panic(sb, "ufs_truncate_direct", "internal error");
 159         frag4 = ufs_fragnum (frag4);
 160         ufs_data_ptr_clear(uspi, p);
 161
 162         ufs_free_fragments (inode, tmp, frag4);
 163         mark_inode_dirty(inode);
 164  next3:
 165
 166         UFSD("EXIT: ino %lu\n", inode->i_ino);
 167         return retry;
 168 }
 169
 170
 171 static int ufs_trunc_indirect(struct inode *inode, u64 offset, void *p)
 172 {
 173         struct super_block * sb;
 174         struct ufs_sb_private_info * uspi;
 175         struct ufs_buffer_head * ind_ubh;
 176         void *ind;
 177         u64 tmp, indirect_block, i, frag_to_free;
 178         unsigned free_count;
 179         int retry;
 180
 181         UFSD("ENTER: ino %lu, offset %llu, p: %p\n",
 182              inode->i_ino, (unsigned long long)offset, p);
 183
 184         BUG_ON(!p);
 185
 186         sb = inode->i_sb;
 187         uspi = UFS_SB(sb)->s_uspi;
 188
 189         frag_to_free = 0;
 190         free_count = 0;
 191         retry = 0;
 192
 193         tmp = ufs_data_ptr_to_cpu(sb, p);
 194         if (!tmp)
 195                 return 0;
 196         ind_ubh = ubh_bread(sb, tmp, uspi->s_bsize);
 197         if (tmp != ufs_data_ptr_to_cpu(sb, p)) {
 198                 ubh_brelse (ind_ubh);
 199                 return 1;
 200         }
 201         if (!ind_ubh) {
 202                 ufs_data_ptr_clear(uspi, p);
 203                 return 0;
 204         }
 205
 206         indirect_block = (DIRECT_BLOCK > offset) ? (DIRECT_BLOCK - offset) : 0;
 207         for (i = indirect_block; i < uspi->s_apb; i++) {
 208                 ind = ubh_get_data_ptr(uspi, ind_ubh, i);
 209                 tmp = ufs_data_ptr_to_cpu(sb, ind);
 210                 if (!tmp)
 211                         continue;
 212
 213                 ufs_data_ptr_clear(uspi, ind);
 214                 ubh_mark_buffer_dirty(ind_ubh);
 215                 if (free_count == 0) {
 216                         frag_to_free = tmp;
 217                         free_count = uspi->s_fpb;
 218                 } else if (free_count > 0 && frag_to_free == tmp - free_count)
 219                         free_count += uspi->s_fpb;
 220                 else {
 221                         ufs_free_blocks (inode, frag_to_free, free_count);
 222                         frag_to_free = tmp;
 223                         free_count = uspi->s_fpb;
 224                 }
 225
 226                 mark_inode_dirty(inode);
 227         }
 228
 229         if (free_count > 0) {
 230                 ufs_free_blocks (inode, frag_to_free, free_count);
 231         }
 232         for (i = 0; i < uspi->s_apb; i++)
 233                 if (!ufs_is_data_ptr_zero(uspi,
 234                                           ubh_get_data_ptr(uspi, ind_ubh, i)))
 235                         break;
 236         if (i >= uspi->s_apb) {
 237                 tmp = ufs_data_ptr_to_cpu(sb, p);
 238                 ufs_data_ptr_clear(uspi, p);
 239
 240                 ufs_free_blocks (inode, tmp, uspi->s_fpb);
 241                 mark_inode_dirty(inode);
 242                 ubh_bforget(ind_ubh);
 243                 ind_ubh = NULL;
 244         }
 245         if (IS_SYNC(inode) && ind_ubh && ubh_buffer_dirty(ind_ubh)) {
 246                 ubh_ll_rw_block(SWRITE, ind_ubh);
 247                 ubh_wait_on_buffer (ind_ubh);
 248         }
 249         ubh_brelse (ind_ubh);
 250
 251         UFSD("EXIT: ino %lu\n", inode->i_ino);
 252
 253         return retry;
 254 }
 255
 256 static int ufs_trunc_dindirect(struct inode *inode, u64 offset, void *p)
 257 {
 258         struct super_block * sb;
 259         struct ufs_sb_private_info * uspi;
 260         struct ufs_buffer_head *dind_bh;
 261         u64 i, tmp, dindirect_block;
 262         void *dind;
 263         int retry = 0;
 264
 265         UFSD("ENTER: ino %lu\n", inode->i_ino);
 266
 267         sb = inode->i_sb;
 268         uspi = UFS_SB(sb)->s_uspi;
 269
 270         dindirect_block = (DIRECT_BLOCK > offset)
 271                 ? ((DIRECT_BLOCK - offset) >> uspi->s_apbshift) : 0;
 272         retry = 0;
 273
 274         tmp = ufs_data_ptr_to_cpu(sb, p);
 275         if (!tmp)
 276                 return 0;
 277         dind_bh = ubh_bread(sb, tmp, uspi->s_bsize);
 278         if (tmp != ufs_data_ptr_to_cpu(sb, p)) {
 279                 ubh_brelse (dind_bh);
 280                 return 1;
 281         }
 282         if (!dind_bh) {
 283                 ufs_data_ptr_clear(uspi, p);
 284                 return 0;
 285         }
 286
 287         for (i = dindirect_block ; i < uspi->s_apb ; i++) {
 288                 dind = ubh_get_data_ptr(uspi, dind_bh, i);
 289                 tmp = ufs_data_ptr_to_cpu(sb, dind);
 290                 if (!tmp)
 291                         continue;
 292                 retry |= ufs_trunc_indirect (inode, offset + (i << uspi->s_apbshift), dind);
 293                 ubh_mark_buffer_dirty(dind_bh);
 294         }
 295
 296         for (i = 0; i < uspi->s_apb; i++)
 297                 if (!ufs_is_data_ptr_zero(uspi,
 298                                           ubh_get_data_ptr(uspi, dind_bh, i)))
 299                         break;
 300         if (i >= uspi->s_apb) {
 301                 tmp = ufs_data_ptr_to_cpu(sb, p);
 302                 ufs_data_ptr_clear(uspi, p);
 303
 304                 ufs_free_blocks(inode, tmp, uspi->s_fpb);
 305                 mark_inode_dirty(inode);
 306                 ubh_bforget(dind_bh);
 307                 dind_bh = NULL;
 308         }
 309         if (IS_SYNC(inode) && dind_bh && ubh_buffer_dirty(dind_bh)) {
 310                 ubh_ll_rw_block(SWRITE, dind_bh);
 311                 ubh_wait_on_buffer (dind_bh);
 312         }
 313         ubh_brelse (dind_bh);
 314
 315         UFSD("EXIT: ino %lu\n", inode->i_ino);
 316
 317         return retry;
 318 }
 319
 320 static int ufs_trunc_tindirect(struct inode *inode)
 321 {
 322         struct super_block *sb = inode->i_sb;
 323         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
 324         struct ufs_inode_info *ufsi = UFS_I(inode);
 325         struct ufs_buffer_head * tind_bh;
 326         u64 tindirect_block, tmp, i;
 327         void *tind, *p;
 328         int retry;
 329
 330         UFSD("ENTER: ino %lu\n", inode->i_ino);
 331
 332         retry = 0;
 333
 334         tindirect_block = (DIRECT_BLOCK > (UFS_NDADDR + uspi->s_apb + uspi->s_2apb))
 335                 ? ((DIRECT_BLOCK - UFS_NDADDR - uspi->s_apb - uspi->s_2apb) >> uspi->s_2apbshift) : 0;
 336
 337         p = ufs_get_direct_data_ptr(uspi, ufsi, UFS_TIND_BLOCK);
 338         if (!(tmp = ufs_data_ptr_to_cpu(sb, p)))
 339                 return 0;
 340         tind_bh = ubh_bread (sb, tmp, uspi->s_bsize);
 341         if (tmp != ufs_data_ptr_to_cpu(sb, p)) {
 342                 ubh_brelse (tind_bh);
 343                 return 1;
 344         }
 345         if (!tind_bh) {
 346                 ufs_data_ptr_clear(uspi, p);
 347                 return 0;
 348         }
 349
 350         for (i = tindirect_block ; i < uspi->s_apb ; i++) {
 351                 tind = ubh_get_data_ptr(uspi, tind_bh, i);
 352                 retry |= ufs_trunc_dindirect(inode, UFS_NDADDR +
 353                         uspi->s_apb + ((i + 1) << uspi->s_2apbshift), tind);
 354                 ubh_mark_buffer_dirty(tind_bh);
 355         }
 356         for (i = 0; i < uspi->s_apb; i++)
 357                 if (!ufs_is_data_ptr_zero(uspi,
 358                                           ubh_get_data_ptr(uspi, tind_bh, i)))
 359                         break;
 360         if (i >= uspi->s_apb) {
 361                 tmp = ufs_data_ptr_to_cpu(sb, p);
 362                 ufs_data_ptr_clear(uspi, p);
 363
 364                 ufs_free_blocks(inode, tmp, uspi->s_fpb);
 365                 mark_inode_dirty(inode);
 366                 ubh_bforget(tind_bh);
 367                 tind_bh = NULL;
 368         }
 369         if (IS_SYNC(inode) && tind_bh && ubh_buffer_dirty(tind_bh)) {
 370                 ubh_ll_rw_block(SWRITE, tind_bh);
 371                 ubh_wait_on_buffer (tind_bh);
 372         }
 373         ubh_brelse (tind_bh);
 374
 375         UFSD("EXIT: ino %lu\n", inode->i_ino);
 376         return retry;
 377 }
 378
 379 static int ufs_alloc_lastblock(struct inode *inode)
 380 {
 381         int err = 0;
 382         struct super_block *sb = inode->i_sb;
 383         struct address_space *mapping = inode->i_mapping;
 384         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
 385         unsigned i, end;
 386         sector_t lastfrag;
 387         struct page *lastpage;
 388         struct buffer_head *bh;
 389         u64 phys64;
 390
 391         lastfrag = (i_size_read(inode) + uspi->s_fsize - 1) >> uspi->s_fshift;
 392
 393         if (!lastfrag)
 394                 goto out;
 395
 396         lastfrag--;
 397
 398         lastpage = ufs_get_locked_page(mapping, lastfrag >>
 399                                        (PAGE_CACHE_SHIFT - inode->i_blkbits));
 400        if (IS_ERR(lastpage)) {
 401                err = -EIO;
 402                goto out;
 403        }
 404
 405        end = lastfrag & ((1 << (PAGE_CACHE_SHIFT - inode->i_blkbits)) - 1);
 406        bh = page_buffers(lastpage);
 407        for (i = 0; i < end; ++i)
 408                bh = bh->b_this_page;
 409
 410
 411        err = ufs_getfrag_block(inode, lastfrag, bh, 1);
 412
 413        if (unlikely(err))
 414                goto out_unlock;
 415
 416        if (buffer_new(bh)) {
 417                clear_buffer_new(bh);
 418                unmap_underlying_metadata(bh->b_bdev,
 419                                          bh->b_blocknr);
 420                /*
 421                 * we do not zeroize fragment, because of
 422                 * if it maped to hole, it already contains zeroes
 423                 */
 424                set_buffer_uptodate(bh);
 425                mark_buffer_dirty(bh);
 426                set_page_dirty(lastpage);
 427        }
 428
 429        if (lastfrag >= UFS_IND_FRAGMENT) {
 430                end = uspi->s_fpb - ufs_fragnum(lastfrag) - 1;
 431                phys64 = bh->b_blocknr + 1;
 432                for (i = 0; i < end; ++i) {
 433                        bh = sb_getblk(sb, i + phys64);
 434                        lock_buffer(bh);
 435                        memset(bh->b_data, 0, sb->s_blocksize);
 436                        set_buffer_uptodate(bh);
 437                        mark_buffer_dirty(bh);
 438                        unlock_buffer(bh);
 439                        sync_dirty_buffer(bh);
 440                        brelse(bh);
 441                }
 442        }
 443 out_unlock:
 444        ufs_put_locked_page(lastpage);
 445 out:
 446        return err;
 447 }
 448
 449 int ufs_truncate(struct inode *inode, loff_t old_i_size)
 450 {
 451         struct ufs_inode_info *ufsi = UFS_I(inode);
 452         struct super_block *sb = inode->i_sb;
 453         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
 454         int retry, err = 0;
 455
 456         UFSD("ENTER: ino %lu, i_size: %llu, old_i_size: %llu\n",
 457              inode->i_ino, (unsigned long long)i_size_read(inode),
 458              (unsigned long long)old_i_size);
 459
 460         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 461               S_ISLNK(inode->i_mode)))
 462                 return -EINVAL;
 463         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 464                 return -EPERM;
 465
 466         err = ufs_alloc_lastblock(inode);
 467
 468         if (err) {
 469                 i_size_write(inode, old_i_size);
 470                 goto out;
 471         }
 472
 473         block_truncate_page(inode->i_mapping, inode->i_size, ufs_getfrag_block);
 474
 475         lock_kernel();
 476         while (1) {
 477                 retry = ufs_trunc_direct(inode);
 478                 retry |= ufs_trunc_indirect(inode, UFS_IND_BLOCK,
 479                                             ufs_get_direct_data_ptr(uspi, ufsi,
 480                                                                     UFS_IND_BLOCK));
 481                 retry |= ufs_trunc_dindirect(inode, UFS_IND_BLOCK + uspi->s_apb,
 482                                              ufs_get_direct_data_ptr(uspi, ufsi,
 483                                                                      UFS_DIND_BLOCK));
 484                 retry |= ufs_trunc_tindirect (inode);
 485                 if (!retry)
 486                         break;
 487                 if (IS_SYNC(inode) && (inode->i_state & I_DIRTY))
 488                         ufs_sync_inode (inode);
 489                 blk_run_address_space(inode->i_mapping);
 490                 yield();
 491         }
 492
 493         inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
 494         ufsi->i_lastfrag = DIRECT_FRAGMENT;
 495         unlock_kernel();
 496         mark_inode_dirty(inode);
 497 out:
 498         UFSD("EXIT: err %d\n", err);
 499         return err;
 500 }
 501
 502
 503 /*
 504  * We don't define our `inode->i_op->truncate', and call it here,
 505  * because of:
 506  * - there is no way to know old size
 507  * - there is no way inform user about error, if it happens in `truncate'
 508  */
 509 static int ufs_setattr(struct dentry *dentry, struct iattr *attr)
 510 {
 511         struct inode *inode = dentry->d_inode;
 512         unsigned int ia_valid = attr->ia_valid;
 513         int error;
 514
 515         error = inode_change_ok(inode, attr);
 516         if (error)
 517                 return error;
 518
 519         if (ia_valid & ATTR_SIZE &&
 520             attr->ia_size != i_size_read(inode)) {
 521                 loff_t old_i_size = inode->i_size;
 522                 error = vmtruncate(inode, attr->ia_size);
 523                 if (error)
 524                         return error;
 525                 error = ufs_truncate(inode, old_i_size);
 526                 if (error)
 527                         return error;
 528         }
 529         return inode_setattr(inode, attr);
 530 }
 531
 532 const struct inode_operations ufs_file_inode_operations = {
 533         .setattr = ufs_setattr,
 534 };