Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/fs/ext2fs/ext2_inode.c
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1 /*- 2 * modified for Lites 1.1 3 * 4 * Aug 1995, Godmar Back (gback@cs.utah.edu) 5 * University of Utah, Department of Computer Science 6 */ 7 /*- 8 * Copyright (c) 1982, 1986, 1989, 1993 9 * The Regents of the University of California. All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)ffs_inode.c 8.5 (Berkeley) 12/30/93 36 * $FreeBSD: releng/9.2/sys/fs/ext2fs/ext2_inode.c 252008 2013-06-19 20:56:44Z pfg $ 37 */ 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/mount.h> 42 #include <sys/bio.h> 43 #include <sys/buf.h> 44 #include <sys/vnode.h> 45 #include <sys/malloc.h> 46 47 #include <vm/vm.h> 48 #include <vm/vm_extern.h> 49 50 #include <fs/ext2fs/inode.h> 51 #include <fs/ext2fs/ext2_mount.h> 52 #include <fs/ext2fs/ext2fs.h> 53 #include <fs/ext2fs/fs.h> 54 #include <fs/ext2fs/ext2_extern.h> 55 56 static int ext2_indirtrunc(struct inode *, int32_t, int32_t, int32_t, int, 57 long *); 58 59 /* 60 * Update the access, modified, and inode change times as specified by the 61 * IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively. Write the inode 62 * to disk if the IN_MODIFIED flag is set (it may be set initially, or by 63 * the timestamp update). The IN_LAZYMOD flag is set to force a write 64 * later if not now. If we write now, then clear both IN_MODIFIED and 65 * IN_LAZYMOD to reflect the presumably successful write, and if waitfor is 66 * set, then wait for the write to complete. 67 */ 68 int 69 ext2_update(struct vnode *vp, int waitfor) 70 { 71 struct m_ext2fs *fs; 72 struct buf *bp; 73 struct inode *ip; 74 int error; 75 76 ASSERT_VOP_ELOCKED(vp, "ext2_update"); 77 ext2_itimes(vp); 78 ip = VTOI(vp); 79 if ((ip->i_flag & IN_MODIFIED) == 0 && waitfor == 0) 80 return (0); 81 ip->i_flag &= ~(IN_LAZYACCESS | IN_LAZYMOD | IN_MODIFIED); 82 fs = ip->i_e2fs; 83 if(fs->e2fs_ronly) 84 return (0); 85 if ((error = bread(ip->i_devvp, 86 fsbtodb(fs, ino_to_fsba(fs, ip->i_number)), 87 (int)fs->e2fs_bsize, NOCRED, &bp)) != 0) { 88 brelse(bp); 89 return (error); 90 } 91 ext2_i2ei(ip, (struct ext2fs_dinode *)((char *)bp->b_data + 92 EXT2_INODE_SIZE(fs) * ino_to_fsbo(fs, ip->i_number))); 93 if (waitfor && !DOINGASYNC(vp)) 94 return (bwrite(bp)); 95 else { 96 bdwrite(bp); 97 return (0); 98 } 99 } 100 101 #define SINGLE 0 /* index of single indirect block */ 102 #define DOUBLE 1 /* index of double indirect block */ 103 #define TRIPLE 2 /* index of triple indirect block */ 104 /* 105 * Truncate the inode oip to at most length size, freeing the 106 * disk blocks. 107 */ 108 int 109 ext2_truncate(struct vnode *vp, off_t length, int flags, struct ucred *cred, 110 struct thread *td) 111 { 112 struct vnode *ovp = vp; 113 int32_t lastblock; 114 struct inode *oip; 115 int32_t bn, lbn, lastiblock[NIADDR], indir_lbn[NIADDR]; 116 uint32_t oldblks[NDADDR + NIADDR], newblks[NDADDR + NIADDR]; 117 struct bufobj *bo; 118 struct m_ext2fs *fs; 119 struct buf *bp; 120 int offset, size, level; 121 long count, nblocks, blocksreleased = 0; 122 int error, i, allerror; 123 off_t osize; 124 125 oip = VTOI(ovp); 126 bo = &ovp->v_bufobj; 127 128 ASSERT_VOP_LOCKED(vp, "ext2_truncate"); 129 130 if (length < 0) 131 return (EINVAL); 132 133 if (ovp->v_type == VLNK && 134 oip->i_size < ovp->v_mount->mnt_maxsymlinklen) { 135 #ifdef INVARIANTS 136 if (length != 0) 137 panic("ext2_truncate: partial truncate of symlink"); 138 #endif 139 bzero((char *)&oip->i_shortlink, (u_int)oip->i_size); 140 oip->i_size = 0; 141 oip->i_flag |= IN_CHANGE | IN_UPDATE; 142 return (ext2_update(ovp, 1)); 143 } 144 if (oip->i_size == length) { 145 oip->i_flag |= IN_CHANGE | IN_UPDATE; 146 return (ext2_update(ovp, 0)); 147 } 148 fs = oip->i_e2fs; 149 osize = oip->i_size; 150 /* 151 * Lengthen the size of the file. We must ensure that the 152 * last byte of the file is allocated. Since the smallest 153 * value of osize is 0, length will be at least 1. 154 */ 155 if (osize < length) { 156 if (length > oip->i_e2fs->e2fs_maxfilesize) 157 return (EFBIG); 158 vnode_pager_setsize(ovp, length); 159 offset = blkoff(fs, length - 1); 160 lbn = lblkno(fs, length - 1); 161 flags |= BA_CLRBUF; 162 error = ext2_balloc(oip, lbn, offset + 1, cred, &bp, flags); 163 if (error) { 164 vnode_pager_setsize(vp, osize); 165 return (error); 166 } 167 oip->i_size = length; 168 if (bp->b_bufsize == fs->e2fs_bsize) 169 bp->b_flags |= B_CLUSTEROK; 170 if (flags & IO_SYNC) 171 bwrite(bp); 172 else if (DOINGASYNC(ovp)) 173 bdwrite(bp); 174 else 175 bawrite(bp); 176 oip->i_flag |= IN_CHANGE | IN_UPDATE; 177 return (ext2_update(ovp, !DOINGASYNC(ovp))); 178 } 179 /* 180 * Shorten the size of the file. If the file is not being 181 * truncated to a block boundry, the contents of the 182 * partial block following the end of the file must be 183 * zero'ed in case it ever become accessible again because 184 * of subsequent file growth. 185 */ 186 /* I don't understand the comment above */ 187 offset = blkoff(fs, length); 188 if (offset == 0) { 189 oip->i_size = length; 190 } else { 191 lbn = lblkno(fs, length); 192 flags |= BA_CLRBUF; 193 error = ext2_balloc(oip, lbn, offset, cred, &bp, flags); 194 if (error) 195 return (error); 196 oip->i_size = length; 197 size = blksize(fs, oip, lbn); 198 bzero((char *)bp->b_data + offset, (u_int)(size - offset)); 199 allocbuf(bp, size); 200 if (bp->b_bufsize == fs->e2fs_bsize) 201 bp->b_flags |= B_CLUSTEROK; 202 if (flags & IO_SYNC) 203 bwrite(bp); 204 else if (DOINGASYNC(ovp)) 205 bdwrite(bp); 206 else 207 bawrite(bp); 208 } 209 /* 210 * Calculate index into inode's block list of 211 * last direct and indirect blocks (if any) 212 * which we want to keep. Lastblock is -1 when 213 * the file is truncated to 0. 214 */ 215 lastblock = lblkno(fs, length + fs->e2fs_bsize - 1) - 1; 216 lastiblock[SINGLE] = lastblock - NDADDR; 217 lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs); 218 lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs); 219 nblocks = btodb(fs->e2fs_bsize); 220 /* 221 * Update file and block pointers on disk before we start freeing 222 * blocks. If we crash before free'ing blocks below, the blocks 223 * will be returned to the free list. lastiblock values are also 224 * normalized to -1 for calls to ext2_indirtrunc below. 225 */ 226 bcopy((caddr_t)&oip->i_db[0], (caddr_t)oldblks, sizeof(oldblks)); 227 for (level = TRIPLE; level >= SINGLE; level--) 228 if (lastiblock[level] < 0) { 229 oip->i_ib[level] = 0; 230 lastiblock[level] = -1; 231 } 232 for (i = NDADDR - 1; i > lastblock; i--) 233 oip->i_db[i] = 0; 234 oip->i_flag |= IN_CHANGE | IN_UPDATE; 235 allerror = ext2_update(ovp, !DOINGASYNC(ovp)); 236 237 /* 238 * Having written the new inode to disk, save its new configuration 239 * and put back the old block pointers long enough to process them. 240 * Note that we save the new block configuration so we can check it 241 * when we are done. 242 */ 243 bcopy((caddr_t)&oip->i_db[0], (caddr_t)newblks, sizeof(newblks)); 244 bcopy((caddr_t)oldblks, (caddr_t)&oip->i_db[0], sizeof(oldblks)); 245 oip->i_size = osize; 246 error = vtruncbuf(ovp, cred, td, length, (int)fs->e2fs_bsize); 247 if (error && (allerror == 0)) 248 allerror = error; 249 vnode_pager_setsize(ovp, length); 250 251 /* 252 * Indirect blocks first. 253 */ 254 indir_lbn[SINGLE] = -NDADDR; 255 indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1; 256 indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1; 257 for (level = TRIPLE; level >= SINGLE; level--) { 258 bn = oip->i_ib[level]; 259 if (bn != 0) { 260 error = ext2_indirtrunc(oip, indir_lbn[level], 261 fsbtodb(fs, bn), lastiblock[level], level, &count); 262 if (error) 263 allerror = error; 264 blocksreleased += count; 265 if (lastiblock[level] < 0) { 266 oip->i_ib[level] = 0; 267 ext2_blkfree(oip, bn, fs->e2fs_fsize); 268 blocksreleased += nblocks; 269 } 270 } 271 if (lastiblock[level] >= 0) 272 goto done; 273 } 274 275 /* 276 * All whole direct blocks or frags. 277 */ 278 for (i = NDADDR - 1; i > lastblock; i--) { 279 long bsize; 280 281 bn = oip->i_db[i]; 282 if (bn == 0) 283 continue; 284 oip->i_db[i] = 0; 285 bsize = blksize(fs, oip, i); 286 ext2_blkfree(oip, bn, bsize); 287 blocksreleased += btodb(bsize); 288 } 289 if (lastblock < 0) 290 goto done; 291 292 /* 293 * Finally, look for a change in size of the 294 * last direct block; release any frags. 295 */ 296 bn = oip->i_db[lastblock]; 297 if (bn != 0) { 298 long oldspace, newspace; 299 300 /* 301 * Calculate amount of space we're giving 302 * back as old block size minus new block size. 303 */ 304 oldspace = blksize(fs, oip, lastblock); 305 oip->i_size = length; 306 newspace = blksize(fs, oip, lastblock); 307 if (newspace == 0) 308 panic("ext2_truncate: newspace"); 309 if (oldspace - newspace > 0) { 310 /* 311 * Block number of space to be free'd is 312 * the old block # plus the number of frags 313 * required for the storage we're keeping. 314 */ 315 bn += numfrags(fs, newspace); 316 ext2_blkfree(oip, bn, oldspace - newspace); 317 blocksreleased += btodb(oldspace - newspace); 318 } 319 } 320 done: 321 #ifdef INVARIANTS 322 for (level = SINGLE; level <= TRIPLE; level++) 323 if (newblks[NDADDR + level] != oip->i_ib[level]) 324 panic("itrunc1"); 325 for (i = 0; i < NDADDR; i++) 326 if (newblks[i] != oip->i_db[i]) 327 panic("itrunc2"); 328 BO_LOCK(bo); 329 if (length == 0 && (bo->bo_dirty.bv_cnt != 0 || 330 bo->bo_clean.bv_cnt != 0)) 331 panic("itrunc3"); 332 BO_UNLOCK(bo); 333 #endif /* INVARIANTS */ 334 /* 335 * Put back the real size. 336 */ 337 oip->i_size = length; 338 if (oip->i_blocks >= blocksreleased) 339 oip->i_blocks -= blocksreleased; 340 else /* sanity */ 341 oip->i_blocks = 0; 342 oip->i_flag |= IN_CHANGE; 343 vnode_pager_setsize(ovp, length); 344 return (allerror); 345 } 346 347 /* 348 * Release blocks associated with the inode ip and stored in the indirect 349 * block bn. Blocks are free'd in LIFO order up to (but not including) 350 * lastbn. If level is greater than SINGLE, the block is an indirect block 351 * and recursive calls to indirtrunc must be used to cleanse other indirect 352 * blocks. 353 * 354 * NB: triple indirect blocks are untested. 355 */ 356 357 static int 358 ext2_indirtrunc(struct inode *ip, int32_t lbn, int32_t dbn, int32_t lastbn, 359 int level, long *countp) 360 { 361 struct buf *bp; 362 struct m_ext2fs *fs = ip->i_e2fs; 363 struct vnode *vp; 364 int32_t *bap, *copy, nb, nlbn, last; 365 long blkcount, factor; 366 int i, nblocks, blocksreleased = 0; 367 int error = 0, allerror = 0; 368 369 /* 370 * Calculate index in current block of last 371 * block to be kept. -1 indicates the entire 372 * block so we need not calculate the index. 373 */ 374 factor = 1; 375 for (i = SINGLE; i < level; i++) 376 factor *= NINDIR(fs); 377 last = lastbn; 378 if (lastbn > 0) 379 last /= factor; 380 nblocks = btodb(fs->e2fs_bsize); 381 /* 382 * Get buffer of block pointers, zero those entries corresponding 383 * to blocks to be free'd, and update on disk copy first. Since 384 * double(triple) indirect before single(double) indirect, calls 385 * to bmap on these blocks will fail. However, we already have 386 * the on disk address, so we have to set the b_blkno field 387 * explicitly instead of letting bread do everything for us. 388 */ 389 vp = ITOV(ip); 390 bp = getblk(vp, lbn, (int)fs->e2fs_bsize, 0, 0, 0); 391 if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0) { 392 bp->b_iocmd = BIO_READ; 393 if (bp->b_bcount > bp->b_bufsize) 394 panic("ext2_indirtrunc: bad buffer size"); 395 bp->b_blkno = dbn; 396 vfs_busy_pages(bp, 0); 397 bp->b_iooffset = dbtob(bp->b_blkno); 398 bstrategy(bp); 399 error = bufwait(bp); 400 } 401 if (error) { 402 brelse(bp); 403 *countp = 0; 404 return (error); 405 } 406 407 bap = (int32_t *)bp->b_data; 408 copy = malloc(fs->e2fs_bsize, M_TEMP, M_WAITOK); 409 bcopy((caddr_t)bap, (caddr_t)copy, (u_int)fs->e2fs_bsize); 410 bzero((caddr_t)&bap[last + 1], 411 (u_int)(NINDIR(fs) - (last + 1)) * sizeof(int32_t)); 412 if (last == -1) 413 bp->b_flags |= B_INVAL; 414 if (DOINGASYNC(vp)) { 415 bdwrite(bp); 416 } else { 417 error = bwrite(bp); 418 if (error) 419 allerror = error; 420 } 421 bap = copy; 422 423 /* 424 * Recursively free totally unused blocks. 425 */ 426 for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last; 427 i--, nlbn += factor) { 428 nb = bap[i]; 429 if (nb == 0) 430 continue; 431 if (level > SINGLE) { 432 if ((error = ext2_indirtrunc(ip, nlbn, 433 fsbtodb(fs, nb), (int32_t)-1, level - 1, &blkcount)) != 0) 434 allerror = error; 435 blocksreleased += blkcount; 436 } 437 ext2_blkfree(ip, nb, fs->e2fs_bsize); 438 blocksreleased += nblocks; 439 } 440 441 /* 442 * Recursively free last partial block. 443 */ 444 if (level > SINGLE && lastbn >= 0) { 445 last = lastbn % factor; 446 nb = bap[i]; 447 if (nb != 0) { 448 if ((error = ext2_indirtrunc(ip, nlbn, fsbtodb(fs, nb), 449 last, level - 1, &blkcount)) != 0) 450 allerror = error; 451 blocksreleased += blkcount; 452 } 453 } 454 free(copy, M_TEMP); 455 *countp = blocksreleased; 456 return (allerror); 457 } 458 459 /* 460 * discard preallocated blocks 461 */ 462 int 463 ext2_inactive(struct vop_inactive_args *ap) 464 { 465 struct vnode *vp = ap->a_vp; 466 struct inode *ip = VTOI(vp); 467 struct thread *td = ap->a_td; 468 int mode, error = 0; 469 470 /* 471 * Ignore inodes related to stale file handles. 472 */ 473 if (ip->i_mode == 0) 474 goto out; 475 if (ip->i_nlink <= 0) { 476 error = ext2_truncate(vp, (off_t)0, 0, NOCRED, td); 477 ip->i_rdev = 0; 478 mode = ip->i_mode; 479 ip->i_mode = 0; 480 ip->i_flag |= IN_CHANGE | IN_UPDATE; 481 ext2_vfree(vp, ip->i_number, mode); 482 } 483 if (ip->i_flag & (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE)) 484 ext2_update(vp, 0); 485 out: 486 /* 487 * If we are done with the inode, reclaim it 488 * so that it can be reused immediately. 489 */ 490 if (ip->i_mode == 0) 491 vrecycle(vp, td); 492 return (error); 493 } 494 495 /* 496 * Reclaim an inode so that it can be used for other purposes. 497 */ 498 int 499 ext2_reclaim(struct vop_reclaim_args *ap) 500 { 501 struct inode *ip; 502 struct vnode *vp = ap->a_vp; 503 504 ip = VTOI(vp); 505 if (ip->i_flag & IN_LAZYMOD) { 506 ip->i_flag |= IN_MODIFIED; 507 ext2_update(vp, 0); 508 } 509 vfs_hash_remove(vp); 510 free(vp->v_data, M_EXT2NODE); 511 vp->v_data = 0; 512 vnode_destroy_vobject(vp); 513 return (0); 514 }
Cache object: 4ef628cc184946b2dbd98329e0cb1068
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