git.oblomov.eu Git - linux-2.6/blob - 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/fcntl.h>
  40 #include <linux/time.h>
  41 #include <linux/stat.h>
  42 #include <linux/string.h>
  43 #include <linux/smp_lock.h>
  44 #include <linux/buffer_head.h>
  45 #include <linux/blkdev.h>
  46 #include <linux/sched.h>
  47
  48 #include "ufs_fs.h"
  49 #include "ufs.h"
  50 #include "swab.h"
  51 #include "util.h"
  52
  53 /*
  54  * Secure deletion currently doesn't work. It interacts very badly
  55  * with buffers shared with memory mappings, and for that reason
  56  * can't be done in the truncate() routines. It should instead be
  57  * done separately in "release()" before calling the truncate routines
  58  * that will release the actual file blocks.
  59  *
  60  *              Linus
  61  */
  62
  63 #define DIRECT_BLOCK ((inode->i_size + uspi->s_bsize - 1) >> uspi->s_bshift)
  64 #define DIRECT_FRAGMENT ((inode->i_size + uspi->s_fsize - 1) >> uspi->s_fshift)
  65
  66
  67 static int ufs_trunc_direct(struct inode *inode)
  68 {
  69         struct ufs_inode_info *ufsi = UFS_I(inode);
  70         struct super_block * sb;
  71         struct ufs_sb_private_info * uspi;
  72         void *p;
  73         u64 frag1, frag2, frag3, frag4, block1, block2;
  74         unsigned frag_to_free, free_count;
  75         unsigned i, tmp;
  76         int retry;
  77
  78         UFSD("ENTER: ino %lu\n", inode->i_ino);
  79
  80         sb = inode->i_sb;
  81         uspi = UFS_SB(sb)->s_uspi;
  82
  83         frag_to_free = 0;
  84         free_count = 0;
  85         retry = 0;
  86
  87         frag1 = DIRECT_FRAGMENT;
  88         frag4 = min_t(u32, UFS_NDIR_FRAGMENT, ufsi->i_lastfrag);
  89         frag2 = ((frag1 & uspi->s_fpbmask) ? ((frag1 | uspi->s_fpbmask) + 1) : frag1);
  90         frag3 = frag4 & ~uspi->s_fpbmask;
  91         block1 = block2 = 0;
  92         if (frag2 > frag3) {
  93                 frag2 = frag4;
  94                 frag3 = frag4 = 0;
  95         } else if (frag2 < frag3) {
  96                 block1 = ufs_fragstoblks (frag2);
  97                 block2 = ufs_fragstoblks (frag3);
  98         }
  99
 100         UFSD("ino %lu, frag1 %llu, frag2 %llu, block1 %llu, block2 %llu,"
 101              " frag3 %llu, frag4 %llu\n", inode->i_ino,
 102              (unsigned long long)frag1, (unsigned long long)frag2,
 103              (unsigned long long)block1, (unsigned long long)block2,
 104              (unsigned long long)frag3, (unsigned long long)frag4);
 105
 106         if (frag1 >= frag2)
 107                 goto next1;
 108
 109         /*
 110          * Free first free fragments
 111          */
 112         p = ufs_get_direct_data_ptr(uspi, ufsi, ufs_fragstoblks(frag1));
 113         tmp = ufs_data_ptr_to_cpu(sb, p);
 114         if (!tmp )
 115                 ufs_panic (sb, "ufs_trunc_direct", "internal error");
 116         frag2 -= frag1;
 117         frag1 = ufs_fragnum (frag1);
 118
 119         ufs_free_fragments(inode, tmp + frag1, frag2);
 120         mark_inode_dirty(inode);
 121         frag_to_free = tmp + frag1;
 122
 123 next1:
 124         /*
 125          * Free whole blocks
 126          */
 127         for (i = block1 ; i < block2; i++) {
 128                 p = ufs_get_direct_data_ptr(uspi, ufsi, i);
 129                 tmp = ufs_data_ptr_to_cpu(sb, p);
 130                 if (!tmp)
 131                         continue;
 132                 ufs_data_ptr_clear(uspi, p);
 133
 134                 if (free_count == 0) {
 135                         frag_to_free = tmp;
 136                         free_count = uspi->s_fpb;
 137                 } else if (free_count > 0 && frag_to_free == tmp - free_count)
 138                         free_count += uspi->s_fpb;
 139                 else {
 140                         ufs_free_blocks (inode, frag_to_free, free_count);
 141                         frag_to_free = tmp;
 142                         free_count = uspi->s_fpb;
 143                 }
 144                 mark_inode_dirty(inode);
 145         }
 146
 147         if (free_count > 0)
 148                 ufs_free_blocks (inode, frag_to_free, free_count);
 149
 150         if (frag3 >= frag4)
 151                 goto next3;
 152
 153         /*
 154          * Free last free fragments
 155          */
 156         p = ufs_get_direct_data_ptr(uspi, ufsi, ufs_fragstoblks(frag3));
 157         tmp = ufs_data_ptr_to_cpu(sb, p);
 158         if (!tmp )
 159                 ufs_panic(sb, "ufs_truncate_direct", "internal error");
 160         frag4 = ufs_fragnum (frag4);
 161         ufs_data_ptr_clear(uspi, p);
 162
 163         ufs_free_fragments (inode, tmp, frag4);
 164         mark_inode_dirty(inode);
 165  next3:
 166
 167         UFSD("EXIT: ino %lu\n", inode->i_ino);
 168         return retry;
 169 }
 170
 171
 172 static int ufs_trunc_indirect(struct inode *inode, u64 offset, void *p)
 173 {
 174         struct super_block * sb;
 175         struct ufs_sb_private_info * uspi;
 176         struct ufs_buffer_head * ind_ubh;
 177         void *ind;
 178         u64 tmp, indirect_block, i, frag_to_free;
 179         unsigned free_count;
 180         int retry;
 181
 182         UFSD("ENTER: ino %lu, offset %llu, p: %p\n",
 183              inode->i_ino, (unsigned long long)offset, p);
 184
 185         BUG_ON(!p);
 186
 187         sb = inode->i_sb;
 188         uspi = UFS_SB(sb)->s_uspi;
 189
 190         frag_to_free = 0;
 191         free_count = 0;
 192         retry = 0;
 193
 194         tmp = ufs_data_ptr_to_cpu(sb, p);
 195         if (!tmp)
 196                 return 0;
 197         ind_ubh = ubh_bread(sb, tmp, uspi->s_bsize);
 198         if (tmp != ufs_data_ptr_to_cpu(sb, p)) {
 199                 ubh_brelse (ind_ubh);
 200                 return 1;
 201         }
 202         if (!ind_ubh) {
 203                 ufs_data_ptr_clear(uspi, p);
 204                 return 0;
 205         }
 206
 207         indirect_block = (DIRECT_BLOCK > offset) ? (DIRECT_BLOCK - offset) : 0;
 208         for (i = indirect_block; i < uspi->s_apb; i++) {
 209                 ind = ubh_get_data_ptr(uspi, ind_ubh, i);
 210                 tmp = ufs_data_ptr_to_cpu(sb, ind);
 211                 if (!tmp)
 212                         continue;
 213
 214                 ufs_data_ptr_clear(uspi, ind);
 215                 ubh_mark_buffer_dirty(ind_ubh);
 216                 if (free_count == 0) {
 217                         frag_to_free = tmp;
 218                         free_count = uspi->s_fpb;
 219                 } else if (free_count > 0 && frag_to_free == tmp - free_count)
 220                         free_count += uspi->s_fpb;
 221                 else {
 222                         ufs_free_blocks (inode, frag_to_free, free_count);
 223                         frag_to_free = tmp;
 224                         free_count = uspi->s_fpb;
 225                 }
 226
 227                 mark_inode_dirty(inode);
 228         }
 229
 230         if (free_count > 0) {
 231                 ufs_free_blocks (inode, frag_to_free, free_count);
 232         }
 233         for (i = 0; i < uspi->s_apb; i++)
 234                 if (!ufs_is_data_ptr_zero(uspi,
 235                                           ubh_get_data_ptr(uspi, ind_ubh, i)))
 236                         break;
 237         if (i >= uspi->s_apb) {
 238                 tmp = ufs_data_ptr_to_cpu(sb, p);
 239                 ufs_data_ptr_clear(uspi, p);
 240
 241                 ufs_free_blocks (inode, tmp, uspi->s_fpb);
 242                 mark_inode_dirty(inode);
 243                 ubh_bforget(ind_ubh);
 244                 ind_ubh = NULL;
 245         }
 246         if (IS_SYNC(inode) && ind_ubh && ubh_buffer_dirty(ind_ubh)) {
 247                 ubh_ll_rw_block(SWRITE, ind_ubh);
 248                 ubh_wait_on_buffer (ind_ubh);
 249         }
 250         ubh_brelse (ind_ubh);
 251
 252         UFSD("EXIT: ino %lu\n", inode->i_ino);
 253
 254         return retry;
 255 }
 256
 257 static int ufs_trunc_dindirect(struct inode *inode, u64 offset, void *p)
 258 {
 259         struct super_block * sb;
 260         struct ufs_sb_private_info * uspi;
 261         struct ufs_buffer_head *dind_bh;
 262         u64 i, tmp, dindirect_block;
 263         void *dind;
 264         int retry = 0;
 265
 266         UFSD("ENTER: ino %lu\n", inode->i_ino);
 267
 268         sb = inode->i_sb;
 269         uspi = UFS_SB(sb)->s_uspi;
 270
 271         dindirect_block = (DIRECT_BLOCK > offset)
 272                 ? ((DIRECT_BLOCK - offset) >> uspi->s_apbshift) : 0;
 273         retry = 0;
 274
 275         tmp = ufs_data_ptr_to_cpu(sb, p);
 276         if (!tmp)
 277                 return 0;
 278         dind_bh = ubh_bread(sb, tmp, uspi->s_bsize);
 279         if (tmp != ufs_data_ptr_to_cpu(sb, p)) {
 280                 ubh_brelse (dind_bh);
 281                 return 1;
 282         }
 283         if (!dind_bh) {
 284                 ufs_data_ptr_clear(uspi, p);
 285                 return 0;
 286         }
 287
 288         for (i = dindirect_block ; i < uspi->s_apb ; i++) {
 289                 dind = ubh_get_data_ptr(uspi, dind_bh, i);
 290                 tmp = ufs_data_ptr_to_cpu(sb, dind);
 291                 if (!tmp)
 292                         continue;
 293                 retry |= ufs_trunc_indirect (inode, offset + (i << uspi->s_apbshift), dind);
 294                 ubh_mark_buffer_dirty(dind_bh);
 295         }
 296
 297         for (i = 0; i < uspi->s_apb; i++)
 298                 if (!ufs_is_data_ptr_zero(uspi,
 299                                           ubh_get_data_ptr(uspi, dind_bh, i)))
 300                         break;
 301         if (i >= uspi->s_apb) {
 302                 tmp = ufs_data_ptr_to_cpu(sb, p);
 303                 ufs_data_ptr_clear(uspi, p);
 304
 305                 ufs_free_blocks(inode, tmp, uspi->s_fpb);
 306                 mark_inode_dirty(inode);
 307                 ubh_bforget(dind_bh);
 308                 dind_bh = NULL;
 309         }
 310         if (IS_SYNC(inode) && dind_bh && ubh_buffer_dirty(dind_bh)) {
 311                 ubh_ll_rw_block(SWRITE, dind_bh);
 312                 ubh_wait_on_buffer (dind_bh);
 313         }
 314         ubh_brelse (dind_bh);
 315
 316         UFSD("EXIT: ino %lu\n", inode->i_ino);
 317
 318         return retry;
 319 }
 320
 321 static int ufs_trunc_tindirect(struct inode *inode)
 322 {
 323         struct super_block *sb = inode->i_sb;
 324         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
 325         struct ufs_inode_info *ufsi = UFS_I(inode);
 326         struct ufs_buffer_head * tind_bh;
 327         u64 tindirect_block, tmp, i;
 328         void *tind, *p;
 329         int retry;
 330
 331         UFSD("ENTER: ino %lu\n", inode->i_ino);
 332
 333         retry = 0;
 334
 335         tindirect_block = (DIRECT_BLOCK > (UFS_NDADDR + uspi->s_apb + uspi->s_2apb))
 336                 ? ((DIRECT_BLOCK - UFS_NDADDR - uspi->s_apb - uspi->s_2apb) >> uspi->s_2apbshift) : 0;
 337
 338         p = ufs_get_direct_data_ptr(uspi, ufsi, UFS_TIND_BLOCK);
 339         if (!(tmp = ufs_data_ptr_to_cpu(sb, p)))
 340                 return 0;
 341         tind_bh = ubh_bread (sb, tmp, uspi->s_bsize);
 342         if (tmp != ufs_data_ptr_to_cpu(sb, p)) {
 343                 ubh_brelse (tind_bh);
 344                 return 1;
 345         }
 346         if (!tind_bh) {
 347                 ufs_data_ptr_clear(uspi, p);
 348                 return 0;
 349         }
 350
 351         for (i = tindirect_block ; i < uspi->s_apb ; i++) {
 352                 tind = ubh_get_data_ptr(uspi, tind_bh, i);
 353                 retry |= ufs_trunc_dindirect(inode, UFS_NDADDR +
 354                         uspi->s_apb + ((i + 1) << uspi->s_2apbshift), tind);
 355                 ubh_mark_buffer_dirty(tind_bh);
 356         }
 357         for (i = 0; i < uspi->s_apb; i++)
 358                 if (!ufs_is_data_ptr_zero(uspi,
 359                                           ubh_get_data_ptr(uspi, tind_bh, i)))
 360                         break;
 361         if (i >= uspi->s_apb) {
 362                 tmp = ufs_data_ptr_to_cpu(sb, p);
 363                 ufs_data_ptr_clear(uspi, p);
 364
 365                 ufs_free_blocks(inode, tmp, uspi->s_fpb);
 366                 mark_inode_dirty(inode);
 367                 ubh_bforget(tind_bh);
 368                 tind_bh = NULL;
 369         }
 370         if (IS_SYNC(inode) && tind_bh && ubh_buffer_dirty(tind_bh)) {
 371                 ubh_ll_rw_block(SWRITE, tind_bh);
 372                 ubh_wait_on_buffer (tind_bh);
 373         }
 374         ubh_brelse (tind_bh);
 375
 376         UFSD("EXIT: ino %lu\n", inode->i_ino);
 377         return retry;
 378 }
 379
 380 static int ufs_alloc_lastblock(struct inode *inode)
 381 {
 382         int err = 0;
 383         struct super_block *sb = inode->i_sb;
 384         struct address_space *mapping = inode->i_mapping;
 385         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
 386         unsigned i, end;
 387         sector_t lastfrag;
 388         struct page *lastpage;
 389         struct buffer_head *bh;
 390         u64 phys64;
 391
 392         lastfrag = (i_size_read(inode) + uspi->s_fsize - 1) >> uspi->s_fshift;
 393
 394         if (!lastfrag)
 395                 goto out;
 396
 397         lastfrag--;
 398
 399         lastpage = ufs_get_locked_page(mapping, lastfrag >>
 400                                        (PAGE_CACHE_SHIFT - inode->i_blkbits));
 401        if (IS_ERR(lastpage)) {
 402                err = -EIO;
 403                goto out;
 404        }
 405
 406        end = lastfrag & ((1 << (PAGE_CACHE_SHIFT - inode->i_blkbits)) - 1);
 407        bh = page_buffers(lastpage);
 408        for (i = 0; i < end; ++i)
 409                bh = bh->b_this_page;
 410
 411
 412        err = ufs_getfrag_block(inode, lastfrag, bh, 1);
 413
 414        if (unlikely(err))
 415                goto out_unlock;
 416
 417        if (buffer_new(bh)) {
 418                clear_buffer_new(bh);
 419                unmap_underlying_metadata(bh->b_bdev,
 420                                          bh->b_blocknr);
 421                /*
 422                 * we do not zeroize fragment, because of
 423                 * if it maped to hole, it already contains zeroes
 424                 */
 425                set_buffer_uptodate(bh);
 426                mark_buffer_dirty(bh);
 427                set_page_dirty(lastpage);
 428        }
 429
 430        if (lastfrag >= UFS_IND_FRAGMENT) {
 431                end = uspi->s_fpb - ufs_fragnum(lastfrag) - 1;
 432                phys64 = bh->b_blocknr + 1;
 433                for (i = 0; i < end; ++i) {
 434                        bh = sb_getblk(sb, i + phys64);
 435                        lock_buffer(bh);
 436                        memset(bh->b_data, 0, sb->s_blocksize);
 437                        set_buffer_uptodate(bh);
 438                        mark_buffer_dirty(bh);
 439                        unlock_buffer(bh);
 440                        sync_dirty_buffer(bh);
 441                        brelse(bh);
 442                }
 443        }
 444 out_unlock:
 445        ufs_put_locked_page(lastpage);
 446 out:
 447        return err;
 448 }
 449
 450 int ufs_truncate(struct inode *inode, loff_t old_i_size)
 451 {
 452         struct ufs_inode_info *ufsi = UFS_I(inode);
 453         struct super_block *sb = inode->i_sb;
 454         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
 455         int retry, err = 0;
 456
 457         UFSD("ENTER: ino %lu, i_size: %llu, old_i_size: %llu\n",
 458              inode->i_ino, (unsigned long long)i_size_read(inode),
 459              (unsigned long long)old_i_size);
 460
 461         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 462               S_ISLNK(inode->i_mode)))
 463                 return -EINVAL;
 464         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 465                 return -EPERM;
 466
 467         err = ufs_alloc_lastblock(inode);
 468
 469         if (err) {
 470                 i_size_write(inode, old_i_size);
 471                 goto out;
 472         }
 473
 474         block_truncate_page(inode->i_mapping, inode->i_size, ufs_getfrag_block);
 475
 476         lock_kernel();
 477         while (1) {
 478                 retry = ufs_trunc_direct(inode);
 479                 retry |= ufs_trunc_indirect(inode, UFS_IND_BLOCK,
 480                                             ufs_get_direct_data_ptr(uspi, ufsi,
 481                                                                     UFS_IND_BLOCK));
 482                 retry |= ufs_trunc_dindirect(inode, UFS_IND_BLOCK + uspi->s_apb,
 483                                              ufs_get_direct_data_ptr(uspi, ufsi,
 484                                                                      UFS_DIND_BLOCK));
 485                 retry |= ufs_trunc_tindirect (inode);
 486                 if (!retry)
 487                         break;
 488                 if (IS_SYNC(inode) && (inode->i_state & I_DIRTY))
 489                         ufs_sync_inode (inode);
 490                 blk_run_address_space(inode->i_mapping);
 491                 yield();
 492         }
 493
 494         inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
 495         ufsi->i_lastfrag = DIRECT_FRAGMENT;
 496         unlock_kernel();
 497         mark_inode_dirty(inode);
 498 out:
 499         UFSD("EXIT: err %d\n", err);
 500         return err;
 501 }
 502
 503
 504 /*
 505  * We don't define our `inode->i_op->truncate', and call it here,
 506  * because of:
 507  * - there is no way to know old size
 508  * - there is no way inform user about error, if it happens in `truncate'
 509  */
 510 static int ufs_setattr(struct dentry *dentry, struct iattr *attr)
 511 {
 512         struct inode *inode = dentry->d_inode;
 513         unsigned int ia_valid = attr->ia_valid;
 514         int error;
 515
 516         error = inode_change_ok(inode, attr);
 517         if (error)
 518                 return error;
 519
 520         if (ia_valid & ATTR_SIZE &&
 521             attr->ia_size != i_size_read(inode)) {
 522                 loff_t old_i_size = inode->i_size;
 523                 error = vmtruncate(inode, attr->ia_size);
 524                 if (error)
 525                         return error;
 526                 error = ufs_truncate(inode, old_i_size);
 527                 if (error)
 528                         return error;
 529         }
 530         return inode_setattr(inode, attr);
 531 }
 532
 533 const struct inode_operations ufs_file_inode_operations = {
 534         .setattr = ufs_setattr,
 535 };