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/10.1/sys/fs/ext2fs/ext2_inode.c 262723 2014-03-04 03:10:31Z 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 #include <sys/rwlock.h> 47 48 #include <vm/vm.h> 49 #include <vm/vm_extern.h> 50 51 #include <fs/ext2fs/inode.h> 52 #include <fs/ext2fs/ext2_mount.h> 53 #include <fs/ext2fs/ext2fs.h> 54 #include <fs/ext2fs/fs.h> 55 #include <fs/ext2fs/ext2_extern.h> 56 57 static int ext2_indirtrunc(struct inode *, daddr_t, daddr_t, 58 daddr_t, int, e4fs_daddr_t *); 59 60 /* 61 * Update the access, modified, and inode change times as specified by the 62 * IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively. Write the inode 63 * to disk if the IN_MODIFIED flag is set (it may be set initially, or by 64 * the timestamp update). The IN_LAZYMOD flag is set to force a write 65 * later if not now. If we write now, then clear both IN_MODIFIED and 66 * IN_LAZYMOD to reflect the presumably successful write, and if waitfor is 67 * set, then wait for the write to complete. 68 */ 69 int 70 ext2_update(struct vnode *vp, int waitfor) 71 { 72 struct m_ext2fs *fs; 73 struct buf *bp; 74 struct inode *ip; 75 int error; 76 77 ASSERT_VOP_ELOCKED(vp, "ext2_update"); 78 ext2_itimes(vp); 79 ip = VTOI(vp); 80 if ((ip->i_flag & IN_MODIFIED) == 0 && waitfor == 0) 81 return (0); 82 ip->i_flag &= ~(IN_LAZYACCESS | IN_LAZYMOD | IN_MODIFIED); 83 fs = ip->i_e2fs; 84 if(fs->e2fs_ronly) 85 return (0); 86 if ((error = bread(ip->i_devvp, 87 fsbtodb(fs, ino_to_fsba(fs, ip->i_number)), 88 (int)fs->e2fs_bsize, NOCRED, &bp)) != 0) { 89 brelse(bp); 90 return (error); 91 } 92 ext2_i2ei(ip, (struct ext2fs_dinode *)((char *)bp->b_data + 93 EXT2_INODE_SIZE(fs) * ino_to_fsbo(fs, ip->i_number))); 94 if (waitfor && !DOINGASYNC(vp)) 95 return (bwrite(bp)); 96 else { 97 bdwrite(bp); 98 return (0); 99 } 100 } 101 102 #define SINGLE 0 /* index of single indirect block */ 103 #define DOUBLE 1 /* index of double indirect block */ 104 #define TRIPLE 2 /* index of triple indirect block */ 105 /* 106 * Truncate the inode oip to at most length size, freeing the 107 * disk blocks. 108 */ 109 int 110 ext2_truncate(struct vnode *vp, off_t length, int flags, struct ucred *cred, 111 struct thread *td) 112 { 113 struct vnode *ovp = vp; 114 int32_t lastblock; 115 struct inode *oip; 116 int32_t bn, lbn, lastiblock[NIADDR], indir_lbn[NIADDR]; 117 uint32_t oldblks[NDADDR + NIADDR], newblks[NDADDR + NIADDR]; 118 struct bufobj *bo; 119 struct m_ext2fs *fs; 120 struct buf *bp; 121 int offset, size, level; 122 e4fs_daddr_t count, nblocks, blocksreleased = 0; 123 int error, i, allerror; 124 off_t osize; 125 126 oip = VTOI(ovp); 127 bo = &ovp->v_bufobj; 128 129 ASSERT_VOP_LOCKED(vp, "ext2_truncate"); 130 131 if (length < 0) 132 return (EINVAL); 133 134 if (ovp->v_type == VLNK && 135 oip->i_size < ovp->v_mount->mnt_maxsymlinklen) { 136 #ifdef INVARIANTS 137 if (length != 0) 138 panic("ext2_truncate: partial truncate of symlink"); 139 #endif 140 bzero((char *)&oip->i_shortlink, (u_int)oip->i_size); 141 oip->i_size = 0; 142 oip->i_flag |= IN_CHANGE | IN_UPDATE; 143 return (ext2_update(ovp, 1)); 144 } 145 if (oip->i_size == length) { 146 oip->i_flag |= IN_CHANGE | IN_UPDATE; 147 return (ext2_update(ovp, 0)); 148 } 149 fs = oip->i_e2fs; 150 osize = oip->i_size; 151 /* 152 * Lengthen the size of the file. We must ensure that the 153 * last byte of the file is allocated. Since the smallest 154 * value of osize is 0, length will be at least 1. 155 */ 156 if (osize < length) { 157 if (length > oip->i_e2fs->e2fs_maxfilesize) 158 return (EFBIG); 159 vnode_pager_setsize(ovp, length); 160 offset = blkoff(fs, length - 1); 161 lbn = lblkno(fs, length - 1); 162 flags |= BA_CLRBUF; 163 error = ext2_balloc(oip, lbn, offset + 1, cred, &bp, flags); 164 if (error) { 165 vnode_pager_setsize(vp, osize); 166 return (error); 167 } 168 oip->i_size = length; 169 if (bp->b_bufsize == fs->e2fs_bsize) 170 bp->b_flags |= B_CLUSTEROK; 171 if (flags & IO_SYNC) 172 bwrite(bp); 173 else if (DOINGASYNC(ovp)) 174 bdwrite(bp); 175 else 176 bawrite(bp); 177 oip->i_flag |= IN_CHANGE | IN_UPDATE; 178 return (ext2_update(ovp, !DOINGASYNC(ovp))); 179 } 180 /* 181 * Shorten the size of the file. If the file is not being 182 * truncated to a block boundry, the contents of the 183 * partial block following the end of the file must be 184 * zero'ed in case it ever become accessible again because 185 * of subsequent file growth. 186 */ 187 /* I don't understand the comment above */ 188 offset = blkoff(fs, length); 189 if (offset == 0) { 190 oip->i_size = length; 191 } else { 192 lbn = lblkno(fs, length); 193 flags |= BA_CLRBUF; 194 error = ext2_balloc(oip, lbn, offset, cred, &bp, flags); 195 if (error) 196 return (error); 197 oip->i_size = length; 198 size = blksize(fs, oip, lbn); 199 bzero((char *)bp->b_data + offset, (u_int)(size - offset)); 200 allocbuf(bp, size); 201 if (bp->b_bufsize == fs->e2fs_bsize) 202 bp->b_flags |= B_CLUSTEROK; 203 if (flags & IO_SYNC) 204 bwrite(bp); 205 else if (DOINGASYNC(ovp)) 206 bdwrite(bp); 207 else 208 bawrite(bp); 209 } 210 /* 211 * Calculate index into inode's block list of 212 * last direct and indirect blocks (if any) 213 * which we want to keep. Lastblock is -1 when 214 * the file is truncated to 0. 215 */ 216 lastblock = lblkno(fs, length + fs->e2fs_bsize - 1) - 1; 217 lastiblock[SINGLE] = lastblock - NDADDR; 218 lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs); 219 lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs); 220 nblocks = btodb(fs->e2fs_bsize); 221 /* 222 * Update file and block pointers on disk before we start freeing 223 * blocks. If we crash before free'ing blocks below, the blocks 224 * will be returned to the free list. lastiblock values are also 225 * normalized to -1 for calls to ext2_indirtrunc below. 226 */ 227 bcopy((caddr_t)&oip->i_db[0], (caddr_t)oldblks, sizeof(oldblks)); 228 for (level = TRIPLE; level >= SINGLE; level--) 229 if (lastiblock[level] < 0) { 230 oip->i_ib[level] = 0; 231 lastiblock[level] = -1; 232 } 233 for (i = NDADDR - 1; i > lastblock; i--) 234 oip->i_db[i] = 0; 235 oip->i_flag |= IN_CHANGE | IN_UPDATE; 236 allerror = ext2_update(ovp, !DOINGASYNC(ovp)); 237 238 /* 239 * Having written the new inode to disk, save its new configuration 240 * and put back the old block pointers long enough to process them. 241 * Note that we save the new block configuration so we can check it 242 * when we are done. 243 */ 244 bcopy((caddr_t)&oip->i_db[0], (caddr_t)newblks, sizeof(newblks)); 245 bcopy((caddr_t)oldblks, (caddr_t)&oip->i_db[0], sizeof(oldblks)); 246 oip->i_size = osize; 247 error = vtruncbuf(ovp, cred, length, (int)fs->e2fs_bsize); 248 if (error && (allerror == 0)) 249 allerror = error; 250 vnode_pager_setsize(ovp, length); 251 252 /* 253 * Indirect blocks first. 254 */ 255 indir_lbn[SINGLE] = -NDADDR; 256 indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1; 257 indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1; 258 for (level = TRIPLE; level >= SINGLE; level--) { 259 bn = oip->i_ib[level]; 260 if (bn != 0) { 261 error = ext2_indirtrunc(oip, indir_lbn[level], 262 fsbtodb(fs, bn), lastiblock[level], level, &count); 263 if (error) 264 allerror = error; 265 blocksreleased += count; 266 if (lastiblock[level] < 0) { 267 oip->i_ib[level] = 0; 268 ext2_blkfree(oip, bn, fs->e2fs_fsize); 269 blocksreleased += nblocks; 270 } 271 } 272 if (lastiblock[level] >= 0) 273 goto done; 274 } 275 276 /* 277 * All whole direct blocks or frags. 278 */ 279 for (i = NDADDR - 1; i > lastblock; i--) { 280 long bsize; 281 282 bn = oip->i_db[i]; 283 if (bn == 0) 284 continue; 285 oip->i_db[i] = 0; 286 bsize = blksize(fs, oip, i); 287 ext2_blkfree(oip, bn, bsize); 288 blocksreleased += btodb(bsize); 289 } 290 if (lastblock < 0) 291 goto done; 292 293 /* 294 * Finally, look for a change in size of the 295 * last direct block; release any frags. 296 */ 297 bn = oip->i_db[lastblock]; 298 if (bn != 0) { 299 long oldspace, newspace; 300 301 /* 302 * Calculate amount of space we're giving 303 * back as old block size minus new block size. 304 */ 305 oldspace = blksize(fs, oip, lastblock); 306 oip->i_size = length; 307 newspace = blksize(fs, oip, lastblock); 308 if (newspace == 0) 309 panic("ext2_truncate: newspace"); 310 if (oldspace - newspace > 0) { 311 /* 312 * Block number of space to be free'd is 313 * the old block # plus the number of frags 314 * required for the storage we're keeping. 315 */ 316 bn += numfrags(fs, newspace); 317 ext2_blkfree(oip, bn, oldspace - newspace); 318 blocksreleased += btodb(oldspace - newspace); 319 } 320 } 321 done: 322 #ifdef INVARIANTS 323 for (level = SINGLE; level <= TRIPLE; level++) 324 if (newblks[NDADDR + level] != oip->i_ib[level]) 325 panic("itrunc1"); 326 for (i = 0; i < NDADDR; i++) 327 if (newblks[i] != oip->i_db[i]) 328 panic("itrunc2"); 329 BO_LOCK(bo); 330 if (length == 0 && (bo->bo_dirty.bv_cnt != 0 || 331 bo->bo_clean.bv_cnt != 0)) 332 panic("itrunc3"); 333 BO_UNLOCK(bo); 334 #endif /* INVARIANTS */ 335 /* 336 * Put back the real size. 337 */ 338 oip->i_size = length; 339 if (oip->i_blocks >= blocksreleased) 340 oip->i_blocks -= blocksreleased; 341 else /* sanity */ 342 oip->i_blocks = 0; 343 oip->i_flag |= IN_CHANGE; 344 vnode_pager_setsize(ovp, length); 345 return (allerror); 346 } 347 348 /* 349 * Release blocks associated with the inode ip and stored in the indirect 350 * block bn. Blocks are free'd in LIFO order up to (but not including) 351 * lastbn. If level is greater than SINGLE, the block is an indirect block 352 * and recursive calls to indirtrunc must be used to cleanse other indirect 353 * blocks. 354 * 355 * NB: triple indirect blocks are untested. 356 */ 357 358 static int 359 ext2_indirtrunc(struct inode *ip, daddr_t lbn, daddr_t dbn, 360 daddr_t lastbn, int level, e4fs_daddr_t *countp) 361 { 362 struct buf *bp; 363 struct m_ext2fs *fs = ip->i_e2fs; 364 struct vnode *vp; 365 e2fs_daddr_t *bap, *copy; 366 int i, nblocks, error = 0, allerror = 0; 367 e2fs_lbn_t nb, nlbn, last; 368 e4fs_daddr_t blkcount, factor, blocksreleased = 0; 369 370 /* 371 * Calculate index in current block of last 372 * block to be kept. -1 indicates the entire 373 * block so we need not calculate the index. 374 */ 375 factor = 1; 376 for (i = SINGLE; i < level; i++) 377 factor *= NINDIR(fs); 378 last = lastbn; 379 if (lastbn > 0) 380 last /= factor; 381 nblocks = btodb(fs->e2fs_bsize); 382 /* 383 * Get buffer of block pointers, zero those entries corresponding 384 * to blocks to be free'd, and update on disk copy first. Since 385 * double(triple) indirect before single(double) indirect, calls 386 * to bmap on these blocks will fail. However, we already have 387 * the on disk address, so we have to set the b_blkno field 388 * explicitly instead of letting bread do everything for us. 389 */ 390 vp = ITOV(ip); 391 bp = getblk(vp, lbn, (int)fs->e2fs_bsize, 0, 0, 0); 392 if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0) { 393 bp->b_iocmd = BIO_READ; 394 if (bp->b_bcount > bp->b_bufsize) 395 panic("ext2_indirtrunc: bad buffer size"); 396 bp->b_blkno = dbn; 397 vfs_busy_pages(bp, 0); 398 bp->b_iooffset = dbtob(bp->b_blkno); 399 bstrategy(bp); 400 error = bufwait(bp); 401 } 402 if (error) { 403 brelse(bp); 404 *countp = 0; 405 return (error); 406 } 407 408 bap = (e2fs_daddr_t *)bp->b_data; 409 copy = malloc(fs->e2fs_bsize, M_TEMP, M_WAITOK); 410 bcopy((caddr_t)bap, (caddr_t)copy, (u_int)fs->e2fs_bsize); 411 bzero((caddr_t)&bap[last + 1], 412 (NINDIR(fs) - (last + 1)) * sizeof(e2fs_daddr_t)); 413 if (last == -1) 414 bp->b_flags |= B_INVAL; 415 if (DOINGASYNC(vp)) { 416 bdwrite(bp); 417 } else { 418 error = bwrite(bp); 419 if (error) 420 allerror = error; 421 } 422 bap = copy; 423 424 /* 425 * Recursively free totally unused blocks. 426 */ 427 for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last; 428 i--, nlbn += factor) { 429 nb = bap[i]; 430 if (nb == 0) 431 continue; 432 if (level > SINGLE) { 433 if ((error = ext2_indirtrunc(ip, nlbn, 434 fsbtodb(fs, nb), (int32_t)-1, level - 1, &blkcount)) != 0) 435 allerror = error; 436 blocksreleased += blkcount; 437 } 438 ext2_blkfree(ip, nb, fs->e2fs_bsize); 439 blocksreleased += nblocks; 440 } 441 442 /* 443 * Recursively free last partial block. 444 */ 445 if (level > SINGLE && lastbn >= 0) { 446 last = lastbn % factor; 447 nb = bap[i]; 448 if (nb != 0) { 449 if ((error = ext2_indirtrunc(ip, nlbn, fsbtodb(fs, nb), 450 last, level - 1, &blkcount)) != 0) 451 allerror = error; 452 blocksreleased += blkcount; 453 } 454 } 455 free(copy, M_TEMP); 456 *countp = blocksreleased; 457 return (allerror); 458 } 459 460 /* 461 * discard preallocated blocks 462 */ 463 int 464 ext2_inactive(struct vop_inactive_args *ap) 465 { 466 struct vnode *vp = ap->a_vp; 467 struct inode *ip = VTOI(vp); 468 struct thread *td = ap->a_td; 469 int mode, error = 0; 470 471 /* 472 * Ignore inodes related to stale file handles. 473 */ 474 if (ip->i_mode == 0) 475 goto out; 476 if (ip->i_nlink <= 0) { 477 error = ext2_truncate(vp, (off_t)0, 0, NOCRED, td); 478 ip->i_rdev = 0; 479 mode = ip->i_mode; 480 ip->i_mode = 0; 481 ip->i_flag |= IN_CHANGE | IN_UPDATE; 482 ext2_vfree(vp, ip->i_number, mode); 483 } 484 if (ip->i_flag & (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE)) 485 ext2_update(vp, 0); 486 out: 487 /* 488 * If we are done with the inode, reclaim it 489 * so that it can be reused immediately. 490 */ 491 if (ip->i_mode == 0) 492 vrecycle(vp); 493 return (error); 494 } 495 496 /* 497 * Reclaim an inode so that it can be used for other purposes. 498 */ 499 int 500 ext2_reclaim(struct vop_reclaim_args *ap) 501 { 502 struct inode *ip; 503 struct vnode *vp = ap->a_vp; 504 505 ip = VTOI(vp); 506 if (ip->i_flag & IN_LAZYMOD) { 507 ip->i_flag |= IN_MODIFIED; 508 ext2_update(vp, 0); 509 } 510 vfs_hash_remove(vp); 511 free(vp->v_data, M_EXT2NODE); 512 vp->v_data = 0; 513 vnode_destroy_vobject(vp); 514 return (0); 515 }
Cache object: 6f9e94ce40144cdff56f36bfa07f6808
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