1 /* 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)ffs_balloc.c 8.8 (Berkeley) 6/16/95 34 * $FreeBSD: src/sys/ufs/ffs/ffs_balloc.c,v 1.26.2.1 2002/10/10 19:48:20 dillon Exp $ 35 * $DragonFly: src/sys/vfs/ufs/ffs_balloc.c,v 1.19 2008/05/21 18:49:49 dillon Exp $ 36 */ 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/proc.h> 41 #include <sys/buf.h> 42 #include <sys/lock.h> 43 #include <sys/mount.h> 44 #include <sys/vnode.h> 45 46 #include "quota.h" 47 #include "inode.h" 48 #include "ufs_extern.h" 49 50 #include "fs.h" 51 #include "ffs_extern.h" 52 53 /* 54 * Balloc defines the structure of filesystem storage 55 * by allocating the physical blocks on a device given 56 * the inode and the logical block number in a file. 57 * 58 * ffs_balloc(struct vnode *a_vp, ufs_daddr_t a_lbn, int a_size, 59 * struct ucred *a_cred, int a_flags, struct buf *a_bpp) 60 */ 61 int 62 ffs_balloc(struct vop_balloc_args *ap) 63 { 64 struct inode *ip; 65 ufs_daddr_t lbn; 66 int size; 67 struct ucred *cred; 68 int flags; 69 struct fs *fs; 70 ufs_daddr_t nb; 71 struct buf *bp, *nbp, *dbp; 72 struct vnode *vp; 73 struct indir indirs[NIADDR + 2]; 74 ufs_daddr_t newb, *bap, pref; 75 int deallocated, osize, nsize, num, i, error; 76 ufs_daddr_t *allocib, *blkp, *allocblk, allociblk[NIADDR + 1]; 77 ufs_daddr_t *lbns_remfree, lbns[NIADDR + 1]; 78 int unwindidx; 79 int seqcount; 80 81 vp = ap->a_vp; 82 ip = VTOI(vp); 83 fs = ip->i_fs; 84 lbn = lblkno(fs, ap->a_startoffset); 85 size = blkoff(fs, ap->a_startoffset) + ap->a_size; 86 if (size > fs->fs_bsize) 87 panic("ffs_balloc: blk too big"); 88 *ap->a_bpp = NULL; 89 if (lbn < 0) 90 return (EFBIG); 91 cred = ap->a_cred; 92 flags = ap->a_flags; 93 94 /* 95 * The vnode must be locked for us to be able to safely mess 96 * around with the inode. 97 */ 98 if (vn_islocked(vp) != LK_EXCLUSIVE) { 99 panic("ffs_balloc: vnode %p not exclusively locked!", vp); 100 } 101 102 /* 103 * If the next write will extend the file into a new block, 104 * and the file is currently composed of a fragment 105 * this fragment has to be extended to be a full block. 106 */ 107 nb = lblkno(fs, ip->i_size); 108 if (nb < NDADDR && nb < lbn) { 109 /* 110 * The filesize prior to this write can fit in direct 111 * blocks (ex. fragmentation is possibly done) 112 * we are now extending the file write beyond 113 * the block which has end of the file prior to this write. 114 */ 115 osize = blksize(fs, ip, nb); 116 /* 117 * osize gives disk allocated size in the last block. It is 118 * either in fragments or a file system block size. 119 */ 120 if (osize < fs->fs_bsize && osize > 0) { 121 /* A few fragments are already allocated, since the 122 * current extends beyond this block allocated the 123 * complete block as fragments are on in last block. 124 */ 125 error = ffs_realloccg(ip, nb, 126 ffs_blkpref(ip, nb, (int)nb, &ip->i_db[0]), 127 osize, (int)fs->fs_bsize, cred, &bp); 128 if (error) 129 return (error); 130 if (DOINGSOFTDEP(vp)) 131 softdep_setup_allocdirect(ip, nb, 132 dofftofsb(fs, bp->b_bio2.bio_offset), 133 ip->i_db[nb], fs->fs_bsize, osize, bp); 134 /* adjust the inode size, we just grew */ 135 ip->i_size = smalllblktosize(fs, nb + 1); 136 ip->i_db[nb] = dofftofsb(fs, bp->b_bio2.bio_offset); 137 ip->i_flag |= IN_CHANGE | IN_UPDATE; 138 if (flags & B_SYNC) 139 bwrite(bp); 140 else 141 bawrite(bp); 142 /* bp is already released here */ 143 } 144 } 145 /* 146 * The first NDADDR blocks are direct blocks 147 */ 148 if (lbn < NDADDR) { 149 nb = ip->i_db[lbn]; 150 if (nb != 0 && ip->i_size >= smalllblktosize(fs, lbn + 1)) { 151 error = bread(vp, lblktodoff(fs, lbn), fs->fs_bsize, &bp); 152 if (error) { 153 brelse(bp); 154 return (error); 155 } 156 bp->b_bio2.bio_offset = fsbtodoff(fs, nb); 157 *ap->a_bpp = bp; 158 return (0); 159 } 160 if (nb != 0) { 161 /* 162 * Consider need to reallocate a fragment. 163 */ 164 osize = fragroundup(fs, blkoff(fs, ip->i_size)); 165 nsize = fragroundup(fs, size); 166 if (nsize <= osize) { 167 error = bread(vp, lblktodoff(fs, lbn), 168 osize, &bp); 169 if (error) { 170 brelse(bp); 171 return (error); 172 } 173 bp->b_bio2.bio_offset = fsbtodoff(fs, nb); 174 } else { 175 error = ffs_realloccg(ip, lbn, 176 ffs_blkpref(ip, lbn, (int)lbn, 177 &ip->i_db[0]), osize, nsize, cred, &bp); 178 if (error) 179 return (error); 180 if (DOINGSOFTDEP(vp)) 181 softdep_setup_allocdirect(ip, lbn, 182 dofftofsb(fs, bp->b_bio2.bio_offset), 183 nb, nsize, osize, bp); 184 } 185 } else { 186 if (ip->i_size < smalllblktosize(fs, lbn + 1)) 187 nsize = fragroundup(fs, size); 188 else 189 nsize = fs->fs_bsize; 190 error = ffs_alloc(ip, lbn, 191 ffs_blkpref(ip, lbn, (int)lbn, &ip->i_db[0]), 192 nsize, cred, &newb); 193 if (error) 194 return (error); 195 bp = getblk(vp, lblktodoff(fs, lbn), nsize, 0, 0); 196 bp->b_bio2.bio_offset = fsbtodoff(fs, newb); 197 if (flags & B_CLRBUF) 198 vfs_bio_clrbuf(bp); 199 if (DOINGSOFTDEP(vp)) 200 softdep_setup_allocdirect(ip, lbn, newb, 0, 201 nsize, 0, bp); 202 } 203 ip->i_db[lbn] = dofftofsb(fs, bp->b_bio2.bio_offset); 204 ip->i_flag |= IN_CHANGE | IN_UPDATE; 205 *ap->a_bpp = bp; 206 return (0); 207 } 208 /* 209 * Determine the number of levels of indirection. 210 */ 211 pref = 0; 212 if ((error = ufs_getlbns(vp, lbn, indirs, &num)) != 0) 213 return(error); 214 #ifdef DIAGNOSTIC 215 if (num < 1) 216 panic ("ffs_balloc: ufs_bmaparray returned indirect block"); 217 #endif 218 /* 219 * Get a handle on the data block buffer before working through 220 * indirect blocks to avoid a deadlock between the VM system holding 221 * a locked VM page and issuing a BMAP (which tries to lock the 222 * indirect blocks), and the filesystem holding a locked indirect 223 * block and then trying to read a data block (which tries to lock 224 * the underlying VM pages). 225 */ 226 dbp = getblk(vp, lblktodoff(fs, lbn), fs->fs_bsize, 0, 0); 227 228 /* 229 * Setup undo history 230 */ 231 allocib = NULL; 232 allocblk = allociblk; 233 lbns_remfree = lbns; 234 235 unwindidx = -1; 236 237 /* 238 * Fetch the first indirect block directly from the inode, allocating 239 * one if necessary. 240 */ 241 --num; 242 nb = ip->i_ib[indirs[0].in_off]; 243 if (nb == 0) { 244 pref = ffs_blkpref(ip, lbn, 0, NULL); 245 /* 246 * If the filesystem has run out of space we can skip the 247 * full fsync/undo of the main [fail] case since no undo 248 * history has been built yet. Hence the goto fail2. 249 */ 250 if ((error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, 251 cred, &newb)) != 0) 252 goto fail2; 253 nb = newb; 254 *allocblk++ = nb; 255 *lbns_remfree++ = indirs[1].in_lbn; 256 bp = getblk(vp, lblktodoff(fs, indirs[1].in_lbn), 257 fs->fs_bsize, 0, 0); 258 bp->b_bio2.bio_offset = fsbtodoff(fs, nb); 259 vfs_bio_clrbuf(bp); 260 if (DOINGSOFTDEP(vp)) { 261 softdep_setup_allocdirect(ip, NDADDR + indirs[0].in_off, 262 newb, 0, fs->fs_bsize, 0, bp); 263 bdwrite(bp); 264 } else { 265 /* 266 * Write synchronously so that indirect blocks 267 * never point at garbage. 268 */ 269 if (DOINGASYNC(vp)) 270 bdwrite(bp); 271 else if ((error = bwrite(bp)) != 0) 272 goto fail; 273 } 274 allocib = &ip->i_ib[indirs[0].in_off]; 275 *allocib = nb; 276 ip->i_flag |= IN_CHANGE | IN_UPDATE; 277 } 278 279 /* 280 * Fetch through the indirect blocks, allocating as necessary. 281 */ 282 for (i = 1;;) { 283 error = bread(vp, lblktodoff(fs, indirs[i].in_lbn), (int)fs->fs_bsize, &bp); 284 if (error) { 285 brelse(bp); 286 goto fail; 287 } 288 bap = (ufs_daddr_t *)bp->b_data; 289 nb = bap[indirs[i].in_off]; 290 if (i == num) 291 break; 292 i += 1; 293 if (nb != 0) { 294 bqrelse(bp); 295 continue; 296 } 297 if (pref == 0) 298 pref = ffs_blkpref(ip, lbn, 0, NULL); 299 if ((error = 300 ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, cred, &newb)) != 0) { 301 brelse(bp); 302 goto fail; 303 } 304 nb = newb; 305 *allocblk++ = nb; 306 *lbns_remfree++ = indirs[i].in_lbn; 307 nbp = getblk(vp, lblktodoff(fs, indirs[i].in_lbn), 308 fs->fs_bsize, 0, 0); 309 nbp->b_bio2.bio_offset = fsbtodoff(fs, nb); 310 vfs_bio_clrbuf(nbp); 311 if (DOINGSOFTDEP(vp)) { 312 softdep_setup_allocindir_meta(nbp, ip, bp, 313 indirs[i - 1].in_off, nb); 314 bdwrite(nbp); 315 } else { 316 /* 317 * Write synchronously so that indirect blocks 318 * never point at garbage. 319 */ 320 if ((error = bwrite(nbp)) != 0) { 321 brelse(bp); 322 goto fail; 323 } 324 } 325 bap[indirs[i - 1].in_off] = nb; 326 if (allocib == NULL && unwindidx < 0) 327 unwindidx = i - 1; 328 /* 329 * If required, write synchronously, otherwise use 330 * delayed write. 331 */ 332 if (flags & B_SYNC) { 333 bwrite(bp); 334 } else { 335 if (bp->b_bufsize == fs->fs_bsize) 336 bp->b_flags |= B_CLUSTEROK; 337 bdwrite(bp); 338 } 339 } 340 341 /* 342 * Get the data block, allocating if necessary. We have already 343 * called getblk() on the data block buffer, dbp. If we have to 344 * allocate it and B_CLRBUF has been set the inference is an intention 345 * to zero out the related disk blocks, so we do not have to issue 346 * a read. Instead we simply call vfs_bio_clrbuf(). If B_CLRBUF is 347 * not set the caller intends to overwrite the entire contents of the 348 * buffer and we don't waste time trying to clean up the contents. 349 * 350 * bp references the current indirect block. When allocating, 351 * the block must be updated. 352 */ 353 if (nb == 0) { 354 pref = ffs_blkpref(ip, lbn, indirs[i].in_off, &bap[0]); 355 error = ffs_alloc(ip, 356 lbn, pref, (int)fs->fs_bsize, cred, &newb); 357 if (error) { 358 brelse(bp); 359 goto fail; 360 } 361 nb = newb; 362 *allocblk++ = nb; 363 *lbns_remfree++ = lbn; 364 dbp->b_bio2.bio_offset = fsbtodoff(fs, nb); 365 if (flags & B_CLRBUF) 366 vfs_bio_clrbuf(dbp); 367 if (DOINGSOFTDEP(vp)) 368 softdep_setup_allocindir_page(ip, lbn, bp, 369 indirs[i].in_off, nb, 0, dbp); 370 bap[indirs[i].in_off] = nb; 371 /* 372 * If required, write synchronously, otherwise use 373 * delayed write. 374 */ 375 if (flags & B_SYNC) { 376 bwrite(bp); 377 } else { 378 if (bp->b_bufsize == fs->fs_bsize) 379 bp->b_flags |= B_CLUSTEROK; 380 bdwrite(bp); 381 } 382 *ap->a_bpp = dbp; 383 return (0); 384 } 385 brelse(bp); 386 387 /* 388 * At this point all related indirect blocks have been allocated 389 * if necessary and released. bp is no longer valid. dbp holds 390 * our getblk()'d data block. 391 * 392 * XXX we previously performed a cluster_read operation here. 393 */ 394 if (flags & B_CLRBUF) { 395 /* 396 * If B_CLRBUF is set we must validate the invalid portions 397 * of the buffer. This typically requires a read-before- 398 * write. The strategy call will fill in bio_offset in that 399 * case. 400 * 401 * If we hit this case we do a cluster read if possible 402 * since nearby data blocks are likely to be accessed soon 403 * too. 404 */ 405 if ((dbp->b_flags & B_CACHE) == 0) { 406 bqrelse(dbp); 407 seqcount = (flags & B_SEQMASK) >> B_SEQSHIFT; 408 if (seqcount && 409 (vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) { 410 error = cluster_read(vp, (off_t)ip->i_size, 411 lblktodoff(fs, lbn), 412 (int)fs->fs_bsize, 413 MAXBSIZE, seqcount, &dbp); 414 } else { 415 error = bread(vp, lblktodoff(fs, lbn), (int)fs->fs_bsize, &dbp); 416 } 417 if (error) 418 goto fail; 419 } else { 420 dbp->b_bio2.bio_offset = fsbtodoff(fs, nb); 421 } 422 } else { 423 /* 424 * If B_CLRBUF is not set the caller intends to overwrite 425 * the entire contents of the buffer. We can simply set 426 * bio_offset and we are done. 427 */ 428 dbp->b_bio2.bio_offset = fsbtodoff(fs, nb); 429 } 430 *ap->a_bpp = dbp; 431 return (0); 432 fail: 433 /* 434 * If we have failed part way through block allocation, we 435 * have to deallocate any indirect blocks that we have allocated. 436 * We have to fsync the file before we start to get rid of all 437 * of its dependencies so that we do not leave them dangling. 438 * We have to sync it at the end so that the soft updates code 439 * does not find any untracked changes. Although this is really 440 * slow, running out of disk space is not expected to be a common 441 * occurence. The error return from fsync is ignored as we already 442 * have an error to return to the user. 443 */ 444 VOP_FSYNC(vp, MNT_WAIT, 0); 445 for (deallocated = 0, blkp = allociblk, lbns_remfree = lbns; 446 blkp < allocblk; blkp++, lbns_remfree++) { 447 /* 448 * We shall not leave the freed blocks on the vnode 449 * buffer object lists. 450 */ 451 bp = getblk(vp, *lbns_remfree, fs->fs_bsize, 0, 0); 452 bp->b_flags |= (B_INVAL | B_RELBUF); 453 brelse(bp); 454 deallocated += fs->fs_bsize; 455 } 456 457 if (allocib != NULL) { 458 *allocib = 0; 459 } else if (unwindidx >= 0) { 460 int r; 461 462 r = bread(vp, lblktodoff(fs, indirs[unwindidx].in_lbn), (int)fs->fs_bsize, &bp); 463 if (r) { 464 panic("Could not unwind indirect block, error %d", r); 465 brelse(bp); 466 } else { 467 bap = (ufs_daddr_t *)bp->b_data; 468 bap[indirs[unwindidx].in_off] = 0; 469 if (flags & B_SYNC) { 470 bwrite(bp); 471 } else { 472 if (bp->b_bufsize == fs->fs_bsize) 473 bp->b_flags |= B_CLUSTEROK; 474 bdwrite(bp); 475 } 476 } 477 } 478 if (deallocated) { 479 #ifdef QUOTA 480 /* 481 * Restore user's disk quota because allocation failed. 482 */ 483 (void) ufs_chkdq(ip, (long)-btodb(deallocated), cred, FORCE); 484 #endif 485 ip->i_blocks -= btodb(deallocated); 486 ip->i_flag |= IN_CHANGE | IN_UPDATE; 487 } 488 VOP_FSYNC(vp, MNT_WAIT, 0); 489 490 /* 491 * After the buffers are invalidated and on-disk pointers are 492 * cleared, free the blocks. 493 */ 494 for (blkp = allociblk; blkp < allocblk; blkp++) { 495 ffs_blkfree(ip, *blkp, fs->fs_bsize); 496 } 497 498 /* 499 * Cleanup the data block we getblk()'d before returning. 500 */ 501 fail2: 502 brelse(dbp); 503 return (error); 504 } 505 506