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 #include <linux/quotaops.h>
  48
  49 #include "ufs_fs.h"
  50 #include "ufs.h"
  51 #include "swab.h"
  52 #include "util.h"
  53
  54 /*
  55  * Secure deletion currently doesn't work. It interacts very badly
  56  * with buffers shared with memory mappings, and for that reason
  57  * can't be done in the truncate() routines. It should instead be
  58  * done separately in "release()" before calling the truncate routines
  59  * that will release the actual file blocks.
  60  *
  61  *              Linus
  62  */
  63
  64 #define DIRECT_BLOCK ((inode->i_size + uspi->s_bsize - 1) >> uspi->s_bshift)
  65 #define DIRECT_FRAGMENT ((inode->i_size + uspi->s_fsize - 1) >> uspi->s_fshift)
  66
  67
  68 static int ufs_trunc_direct(struct inode *inode)
  69 {
  70         struct ufs_inode_info *ufsi = UFS_I(inode);
  71         struct super_block * sb;
  72         struct ufs_sb_private_info * uspi;
  73         void *p;
  74         u64 frag1, frag2, frag3, frag4, block1, block2;
  75         unsigned frag_to_free, free_count;
  76         unsigned i, tmp;
  77         int retry;
  78
  79         UFSD("ENTER: ino %lu\n", inode->i_ino);
  80
  81         sb = inode->i_sb;
  82         uspi = UFS_SB(sb)->s_uspi;
  83
  84         frag_to_free = 0;
  85         free_count = 0;
  86         retry = 0;
  87
  88         frag1 = DIRECT_FRAGMENT;
  89         frag4 = min_t(u32, UFS_NDIR_FRAGMENT, ufsi->i_lastfrag);
  90         frag2 = ((frag1 & uspi->s_fpbmask) ? ((frag1 | uspi->s_fpbmask) + 1) : frag1);
  91         frag3 = frag4 & ~uspi->s_fpbmask;
  92         block1 = block2 = 0;
  93         if (frag2 > frag3) {
  94                 frag2 = frag4;
  95                 frag3 = frag4 = 0;
  96         } else if (frag2 < frag3) {
  97                 block1 = ufs_fragstoblks (frag2);
  98                 block2 = ufs_fragstoblks (frag3);
  99         }
 100
 101         UFSD("ino %lu, frag1 %llu, frag2 %llu, block1 %llu, block2 %llu,"
 102              " frag3 %llu, frag4 %llu\n", inode->i_ino,
 103              (unsigned long long)frag1, (unsigned long long)frag2,
 104              (unsigned long long)block1, (unsigned long long)block2,
 105              (unsigned long long)frag3, (unsigned long long)frag4);
 106
 107         if (frag1 >= frag2)
 108                 goto next1;
 109
 110         /*
 111          * Free first free fragments
 112          */
 113         p = ufs_get_direct_data_ptr(uspi, ufsi, ufs_fragstoblks(frag1));
 114         tmp = ufs_data_ptr_to_cpu(sb, p);
 115         if (!tmp )
 116                 ufs_panic (sb, "ufs_trunc_direct", "internal error");
 117         frag2 -= frag1;
 118         frag1 = ufs_fragnum (frag1);
 119
 120         ufs_free_fragments(inode, tmp + frag1, frag2);
 121         mark_inode_dirty(inode);
 122         frag_to_free = tmp + frag1;
 123
 124 next1:
 125         /*
 126          * Free whole blocks
 127          */
 128         for (i = block1 ; i < block2; i++) {
 129                 p = ufs_get_direct_data_ptr(uspi, ufsi, i);
 130                 tmp = ufs_data_ptr_to_cpu(sb, p);
 131                 if (!tmp)
 132                         continue;
 133                 ufs_data_ptr_clear(uspi, p);
 134
 135                 if (free_count == 0) {
 136                         frag_to_free = tmp;
 137                         free_count = uspi->s_fpb;
 138                 } else if (free_count > 0 && frag_to_free == tmp - free_count)
 139                         free_count += uspi->s_fpb;
 140                 else {
 141                         ufs_free_blocks (inode, frag_to_free, free_count);
 142                         frag_to_free = tmp;
 143                         free_count = uspi->s_fpb;
 144                 }
 145                 mark_inode_dirty(inode);
 146         }
 147
 148         if (free_count > 0)
 149                 ufs_free_blocks (inode, frag_to_free, free_count);
 150
 151         if (frag3 >= frag4)
 152                 goto next3;
 153
 154         /*
 155          * Free last free fragments
 156          */
 157         p = ufs_get_direct_data_ptr(uspi, ufsi, ufs_fragstoblks(frag3));
 158         tmp = ufs_data_ptr_to_cpu(sb, p);
 159         if (!tmp )
 160                 ufs_panic(sb, "ufs_truncate_direct", "internal error");
 161         frag4 = ufs_fragnum (frag4);
 162         ufs_data_ptr_clear(uspi, p);
 163
 164         ufs_free_fragments (inode, tmp, frag4);
 165         mark_inode_dirty(inode);
 166  next3:
 167
 168         UFSD("EXIT: ino %lu\n", inode->i_ino);
 169         return retry;
 170 }
 171
 172
 173 static int ufs_trunc_indirect(struct inode *inode, u64 offset, void *p)
 174 {
 175         struct super_block * sb;
 176         struct ufs_sb_private_info * uspi;
 177         struct ufs_buffer_head * ind_ubh;
 178         void *ind;
 179         u64 tmp, indirect_block, i, frag_to_free;
 180         unsigned free_count;
 181         int retry;
 182
 183         UFSD("ENTER: ino %lu, offset %llu, p: %p\n",
 184              inode->i_ino, (unsigned long long)offset, p);
 185
 186         BUG_ON(!p);
 187
 188         sb = inode->i_sb;
 189         uspi = UFS_SB(sb)->s_uspi;
 190
 191         frag_to_free = 0;
 192         free_count = 0;
 193         retry = 0;
 194
 195         tmp = ufs_data_ptr_to_cpu(sb, p);
 196         if (!tmp)
 197                 return 0;
 198         ind_ubh = ubh_bread(sb, tmp, uspi->s_bsize);
 199         if (tmp != ufs_data_ptr_to_cpu(sb, p)) {
 200                 ubh_brelse (ind_ubh);
 201                 return 1;
 202         }
 203         if (!ind_ubh) {
 204                 ufs_data_ptr_clear(uspi, p);
 205                 return 0;
 206         }
 207
 208         indirect_block = (DIRECT_BLOCK > offset) ? (DIRECT_BLOCK - offset) : 0;
 209         for (i = indirect_block; i < uspi->s_apb; i++) {
 210                 ind = ubh_get_data_ptr(uspi, ind_ubh, i);
 211                 tmp = ufs_data_ptr_to_cpu(sb, ind);
 212                 if (!tmp)
 213                         continue;
 214
 215                 ufs_data_ptr_clear(uspi, ind);
 216                 ubh_mark_buffer_dirty(ind_ubh);
 217                 if (free_count == 0) {
 218                         frag_to_free = tmp;
 219                         free_count = uspi->s_fpb;
 220                 } else if (free_count > 0 && frag_to_free == tmp - free_count)
 221                         free_count += uspi->s_fpb;
 222                 else {
 223                         ufs_free_blocks (inode, frag_to_free, free_count);
 224                         frag_to_free = tmp;
 225                         free_count = uspi->s_fpb;
 226                 }
 227
 228                 mark_inode_dirty(inode);
 229         }
 230
 231         if (free_count > 0) {
 232                 ufs_free_blocks (inode, frag_to_free, free_count);
 233         }
 234         for (i = 0; i < uspi->s_apb; i++)
 235                 if (!ufs_is_data_ptr_zero(uspi,
 236                                           ubh_get_data_ptr(uspi, ind_ubh, i)))
 237                         break;
 238         if (i >= uspi->s_apb) {
 239                 tmp = ufs_data_ptr_to_cpu(sb, p);
 240                 ufs_data_ptr_clear(uspi, p);
 241
 242                 ufs_free_blocks (inode, tmp, uspi->s_fpb);
 243                 mark_inode_dirty(inode);
 244                 ubh_bforget(ind_ubh);
 245                 ind_ubh = NULL;
 246         }
 247         if (IS_SYNC(inode) && ind_ubh && ubh_buffer_dirty(ind_ubh)) {
 248                 ubh_ll_rw_block(SWRITE, ind_ubh);
 249                 ubh_wait_on_buffer (ind_ubh);
 250         }
 251         ubh_brelse (ind_ubh);
 252
 253         UFSD("EXIT: ino %lu\n", inode->i_ino);
 254
 255         return retry;
 256 }
 257
 258 static int ufs_trunc_dindirect(struct inode *inode, u64 offset, void *p)
 259 {
 260         struct super_block * sb;
 261         struct ufs_sb_private_info * uspi;
 262         struct ufs_buffer_head *dind_bh;
 263         u64 i, tmp, dindirect_block;
 264         void *dind;
 265         int retry = 0;
 266
 267         UFSD("ENTER: ino %lu\n", inode->i_ino);
 268
 269         sb = inode->i_sb;
 270         uspi = UFS_SB(sb)->s_uspi;
 271
 272         dindirect_block = (DIRECT_BLOCK > offset)
 273                 ? ((DIRECT_BLOCK - offset) >> uspi->s_apbshift) : 0;
 274         retry = 0;
 275
 276         tmp = ufs_data_ptr_to_cpu(sb, p);
 277         if (!tmp)
 278                 return 0;
 279         dind_bh = ubh_bread(sb, tmp, uspi->s_bsize);
 280         if (tmp != ufs_data_ptr_to_cpu(sb, p)) {
 281                 ubh_brelse (dind_bh);
 282                 return 1;
 283         }
 284         if (!dind_bh) {
 285                 ufs_data_ptr_clear(uspi, p);
 286                 return 0;
 287         }
 288
 289         for (i = dindirect_block ; i < uspi->s_apb ; i++) {
 290                 dind = ubh_get_data_ptr(uspi, dind_bh, i);
 291                 tmp = ufs_data_ptr_to_cpu(sb, dind);
 292                 if (!tmp)
 293                         continue;
 294                 retry |= ufs_trunc_indirect (inode, offset + (i << uspi->s_apbshift), dind);
 295                 ubh_mark_buffer_dirty(dind_bh);
 296         }
 297
 298         for (i = 0; i < uspi->s_apb; i++)
 299                 if (!ufs_is_data_ptr_zero(uspi,
 300                                           ubh_get_data_ptr(uspi, dind_bh, i)))
 301                         break;
 302         if (i >= uspi->s_apb) {
 303                 tmp = ufs_data_ptr_to_cpu(sb, p);
 304                 ufs_data_ptr_clear(uspi, p);
 305
 306                 ufs_free_blocks(inode, tmp, uspi->s_fpb);
 307                 mark_inode_dirty(inode);
 308                 ubh_bforget(dind_bh);
 309                 dind_bh = NULL;
 310         }
 311         if (IS_SYNC(inode) && dind_bh && ubh_buffer_dirty(dind_bh)) {
 312                 ubh_ll_rw_block(SWRITE, dind_bh);
 313                 ubh_wait_on_buffer (dind_bh);
 314         }
 315         ubh_brelse (dind_bh);
 316
 317         UFSD("EXIT: ino %lu\n", inode->i_ino);
 318
 319         return retry;
 320 }
 321
 322 static int ufs_trunc_tindirect(struct inode *inode)
 323 {
 324         struct super_block *sb = inode->i_sb;
 325         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
 326         struct ufs_inode_info *ufsi = UFS_I(inode);
 327         struct ufs_buffer_head * tind_bh;
 328         u64 tindirect_block, tmp, i;
 329         void *tind, *p;
 330         int retry;
 331
 332         UFSD("ENTER: ino %lu\n", inode->i_ino);
 333
 334         retry = 0;
 335
 336         tindirect_block = (DIRECT_BLOCK > (UFS_NDADDR + uspi->s_apb + uspi->s_2apb))
 337                 ? ((DIRECT_BLOCK - UFS_NDADDR - uspi->s_apb - uspi->s_2apb) >> uspi->s_2apbshift) : 0;
 338
 339         p = ufs_get_direct_data_ptr(uspi, ufsi, UFS_TIND_BLOCK);
 340         if (!(tmp = ufs_data_ptr_to_cpu(sb, p)))
 341                 return 0;
 342         tind_bh = ubh_bread (sb, tmp, uspi->s_bsize);
 343         if (tmp != ufs_data_ptr_to_cpu(sb, p)) {
 344                 ubh_brelse (tind_bh);
 345                 return 1;
 346         }
 347         if (!tind_bh) {
 348                 ufs_data_ptr_clear(uspi, p);
 349                 return 0;
 350         }
 351
 352         for (i = tindirect_block ; i < uspi->s_apb ; i++) {
 353                 tind = ubh_get_data_ptr(uspi, tind_bh, i);
 354                 retry |= ufs_trunc_dindirect(inode, UFS_NDADDR +
 355                         uspi->s_apb + ((i + 1) << uspi->s_2apbshift), tind);
 356                 ubh_mark_buffer_dirty(tind_bh);
 357         }
 358         for (i = 0; i < uspi->s_apb; i++)
 359                 if (!ufs_is_data_ptr_zero(uspi,
 360                                           ubh_get_data_ptr(uspi, tind_bh, i)))
 361                         break;
 362         if (i >= uspi->s_apb) {
 363                 tmp = ufs_data_ptr_to_cpu(sb, p);
 364                 ufs_data_ptr_clear(uspi, p);
 365
 366                 ufs_free_blocks(inode, tmp, uspi->s_fpb);
 367                 mark_inode_dirty(inode);
 368                 ubh_bforget(tind_bh);
 369                 tind_bh = NULL;
 370         }
 371         if (IS_SYNC(inode) && tind_bh && ubh_buffer_dirty(tind_bh)) {
 372                 ubh_ll_rw_block(SWRITE, tind_bh);
 373                 ubh_wait_on_buffer (tind_bh);
 374         }
 375         ubh_brelse (tind_bh);
 376
 377         UFSD("EXIT: ino %lu\n", inode->i_ino);
 378         return retry;
 379 }
 380
 381 static int ufs_alloc_lastblock(struct inode *inode)
 382 {
 383         int err = 0;
 384         struct super_block *sb = inode->i_sb;
 385         struct address_space *mapping = inode->i_mapping;
 386         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
 387         unsigned i, end;
 388         sector_t lastfrag;
 389         struct page *lastpage;
 390         struct buffer_head *bh;
 391         u64 phys64;
 392
 393         lastfrag = (i_size_read(inode) + uspi->s_fsize - 1) >> uspi->s_fshift;
 394
 395         if (!lastfrag)
 396                 goto out;
 397
 398         lastfrag--;
 399
 400         lastpage = ufs_get_locked_page(mapping, lastfrag >>
 401                                        (PAGE_CACHE_SHIFT - inode->i_blkbits));
 402        if (IS_ERR(lastpage)) {
 403                err = -EIO;
 404                goto out;
 405        }
 406
 407        end = lastfrag & ((1 << (PAGE_CACHE_SHIFT - inode->i_blkbits)) - 1);
 408        bh = page_buffers(lastpage);
 409        for (i = 0; i < end; ++i)
 410                bh = bh->b_this_page;
 411
 412
 413        err = ufs_getfrag_block(inode, lastfrag, bh, 1);
 414
 415        if (unlikely(err))
 416                goto out_unlock;
 417
 418        if (buffer_new(bh)) {
 419                clear_buffer_new(bh);
 420                unmap_underlying_metadata(bh->b_bdev,
 421                                          bh->b_blocknr);
 422                /*
 423                 * we do not zeroize fragment, because of
 424                 * if it maped to hole, it already contains zeroes
 425                 */
 426                set_buffer_uptodate(bh);
 427                mark_buffer_dirty(bh);
 428                set_page_dirty(lastpage);
 429        }
 430
 431        if (lastfrag >= UFS_IND_FRAGMENT) {
 432                end = uspi->s_fpb - ufs_fragnum(lastfrag) - 1;
 433                phys64 = bh->b_blocknr + 1;
 434                for (i = 0; i < end; ++i) {
 435                        bh = sb_getblk(sb, i + phys64);
 436                        lock_buffer(bh);
 437                        memset(bh->b_data, 0, sb->s_blocksize);
 438                        set_buffer_uptodate(bh);
 439                        mark_buffer_dirty(bh);
 440                        unlock_buffer(bh);
 441                        sync_dirty_buffer(bh);
 442                        brelse(bh);
 443                }
 444        }
 445 out_unlock:
 446        ufs_put_locked_page(lastpage);
 447 out:
 448        return err;
 449 }
 450
 451 int ufs_truncate(struct inode *inode, loff_t old_i_size)
 452 {
 453         struct ufs_inode_info *ufsi = UFS_I(inode);
 454         struct super_block *sb = inode->i_sb;
 455         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
 456         int retry, err = 0;
 457
 458         UFSD("ENTER: ino %lu, i_size: %llu, old_i_size: %llu\n",
 459              inode->i_ino, (unsigned long long)i_size_read(inode),
 460              (unsigned long long)old_i_size);
 461
 462         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 463               S_ISLNK(inode->i_mode)))
 464                 return -EINVAL;
 465         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 466                 return -EPERM;
 467
 468         err = ufs_alloc_lastblock(inode);
 469
 470         if (err) {
 471                 i_size_write(inode, old_i_size);
 472                 goto out;
 473         }
 474
 475         block_truncate_page(inode->i_mapping, inode->i_size, ufs_getfrag_block);
 476
 477         lock_kernel();
 478         while (1) {
 479                 retry = ufs_trunc_direct(inode);
 480                 retry |= ufs_trunc_indirect(inode, UFS_IND_BLOCK,
 481                                             ufs_get_direct_data_ptr(uspi, ufsi,
 482                                                                     UFS_IND_BLOCK));
 483                 retry |= ufs_trunc_dindirect(inode, UFS_IND_BLOCK + uspi->s_apb,
 484                                              ufs_get_direct_data_ptr(uspi, ufsi,
 485                                                                      UFS_DIND_BLOCK));
 486                 retry |= ufs_trunc_tindirect (inode);
 487                 if (!retry)
 488                         break;
 489                 if (IS_SYNC(inode) && (inode->i_state & I_DIRTY))
 490                         ufs_sync_inode (inode);
 491                 blk_run_address_space(inode->i_mapping);
 492                 yield();
 493         }
 494
 495         inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
 496         ufsi->i_lastfrag = DIRECT_FRAGMENT;
 497         unlock_kernel();
 498         mark_inode_dirty(inode);
 499 out:
 500         UFSD("EXIT: err %d\n", err);
 501         return err;
 502 }
 503
 504
 505 /*
 506  * We don't define our `inode->i_op->truncate', and call it here,
 507  * because of:
 508  * - there is no way to know old size
 509  * - there is no way inform user about error, if it happens in `truncate'
 510  */
 511 static int ufs_setattr(struct dentry *dentry, struct iattr *attr)
 512 {
 513         struct inode *inode = dentry->d_inode;
 514         unsigned int ia_valid = attr->ia_valid;
 515         int error;
 516
 517         error = inode_change_ok(inode, attr);
 518         if (error)
 519                 return error;
 520
 521         if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
 522             (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
 523                 error = dquot_transfer(inode, attr);
 524                 if (error)
 525                         return error;
 526         }
 527         if (ia_valid & ATTR_SIZE &&
 528             attr->ia_size != i_size_read(inode)) {
 529                 loff_t old_i_size = inode->i_size;
 530
 531                 dquot_initialize(inode);
 532
 533                 error = vmtruncate(inode, attr->ia_size);
 534                 if (error)
 535                         return error;
 536                 error = ufs_truncate(inode, old_i_size);
 537                 if (error)
 538                         return error;
 539         }
 540         return inode_setattr(inode, attr);
 541 }
 542
 543 const struct inode_operations ufs_file_inode_operations = {
 544         .setattr = ufs_setattr,
 545 };