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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)ffs_balloc.c 8.8 (Berkeley) 6/16/95 30 * $FreeBSD: src/sys/ufs/ffs/ffs_balloc.c,v 1.26.2.1 2002/10/10 19:48:20 dillon Exp $ 31 */ 32 33 #include "opt_quota.h" 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/proc.h> 38 #include <sys/buf.h> 39 #include <sys/lock.h> 40 #include <sys/mount.h> 41 #include <sys/vnode.h> 42 43 #include <sys/buf2.h> 44 45 #include "quota.h" 46 #include "inode.h" 47 #include "ufs_extern.h" 48 49 #include "fs.h" 50 #include "ffs_extern.h" 51 52 /* 53 * ffs_balloc(struct vnode *a_vp, ufs_daddr_t a_lbn, int a_size, 54 * struct ucred *a_cred, int a_flags, struct buf *a_bpp) 55 * 56 * Balloc defines the structure of filesystem storage by allocating 57 * the physical blocks on a device given the inode and the logical 58 * block number in a file. 59 * 60 * NOTE: B_CLRBUF - this flag tells balloc to clear invalid portions 61 * of the buffer. However, any dirty bits will override missing 62 * valid bits. This case occurs when writable mmaps are truncated 63 * and then extended. 64 */ 65 int 66 ffs_balloc(struct vop_balloc_args *ap) 67 { 68 struct inode *ip; 69 ufs_daddr_t lbn; 70 int size; 71 struct ucred *cred; 72 int flags; 73 struct fs *fs; 74 ufs_daddr_t nb; 75 struct buf *bp, *nbp, *dbp; 76 struct vnode *vp; 77 struct indir indirs[UFS_NIADDR + 2]; 78 ufs_daddr_t newb, *bap, pref; 79 int deallocated, osize, nsize, num, i, error; 80 ufs_daddr_t *allocib, *blkp, *allocblk, allociblk[UFS_NIADDR + 1]; 81 ufs_daddr_t *lbns_remfree, lbns[UFS_NIADDR + 1]; 82 int unwindidx; 83 int seqcount; 84 85 vp = ap->a_vp; 86 ip = VTOI(vp); 87 fs = ip->i_fs; 88 lbn = lblkno(fs, ap->a_startoffset); 89 size = blkoff(fs, ap->a_startoffset) + ap->a_size; 90 if (size > fs->fs_bsize) 91 panic("ffs_balloc: blk too big"); 92 *ap->a_bpp = NULL; 93 if (lbn < 0) 94 return (EFBIG); 95 cred = ap->a_cred; 96 flags = ap->a_flags; 97 98 /* 99 * The vnode must be locked for us to be able to safely mess 100 * around with the inode. 101 */ 102 if (vn_islocked(vp) != LK_EXCLUSIVE) { 103 panic("ffs_balloc: vnode %p not exclusively locked!", vp); 104 } 105 106 /* 107 * If the next write will extend the file into a new block, 108 * and the file is currently composed of a fragment 109 * this fragment has to be extended to be a full block. 110 */ 111 nb = lblkno(fs, ip->i_size); 112 if (nb < UFS_NDADDR && nb < lbn) { 113 /* 114 * The filesize prior to this write can fit in direct 115 * blocks (ex. fragmentation is possibly done) 116 * we are now extending the file write beyond 117 * the block which has end of the file prior to this write. 118 */ 119 osize = blksize(fs, ip, nb); 120 /* 121 * osize gives disk allocated size in the last block. It is 122 * either in fragments or a file system block size. 123 */ 124 if (osize < fs->fs_bsize && osize > 0) { 125 /* A few fragments are already allocated, since the 126 * current extends beyond this block allocated the 127 * complete block as fragments are on in last block. 128 */ 129 error = ffs_realloccg(ip, nb, 130 ffs_blkpref(ip, nb, (int)nb, &ip->i_db[0]), 131 osize, (int)fs->fs_bsize, cred, &bp); 132 if (error) 133 return (error); 134 if (DOINGSOFTDEP(vp)) 135 softdep_setup_allocdirect(ip, nb, 136 dofftofsb(fs, bp->b_bio2.bio_offset), 137 ip->i_db[nb], fs->fs_bsize, osize, bp); 138 /* adjust the inode size, we just grew */ 139 ip->i_size = smalllblktosize(fs, nb + 1); 140 ip->i_db[nb] = dofftofsb(fs, bp->b_bio2.bio_offset); 141 ip->i_flag |= IN_CHANGE | IN_UPDATE; 142 if (flags & B_SYNC) 143 bwrite(bp); 144 else 145 bawrite(bp); 146 /* bp is already released here */ 147 } 148 } 149 /* 150 * The first UFS_NDADDR blocks are direct blocks 151 */ 152 if (lbn < UFS_NDADDR) { 153 nb = ip->i_db[lbn]; 154 if (nb != 0 && ip->i_size >= smalllblktosize(fs, lbn + 1)) { 155 error = bread(vp, lblktodoff(fs, lbn), fs->fs_bsize, &bp); 156 if (error) { 157 brelse(bp); 158 return (error); 159 } 160 bp->b_bio2.bio_offset = fsbtodoff(fs, nb); 161 *ap->a_bpp = bp; 162 return (0); 163 } 164 if (nb != 0) { 165 /* 166 * Consider need to reallocate a fragment. 167 */ 168 osize = fragroundup(fs, blkoff(fs, ip->i_size)); 169 nsize = fragroundup(fs, size); 170 if (nsize <= osize) { 171 error = bread(vp, lblktodoff(fs, lbn), 172 osize, &bp); 173 if (error) { 174 brelse(bp); 175 return (error); 176 } 177 bp->b_bio2.bio_offset = fsbtodoff(fs, nb); 178 } else { 179 /* 180 * NOTE: ffs_realloccg() issues a bread(). 181 */ 182 error = ffs_realloccg(ip, lbn, 183 ffs_blkpref(ip, lbn, (int)lbn, 184 &ip->i_db[0]), osize, nsize, cred, &bp); 185 if (error) 186 return (error); 187 if (DOINGSOFTDEP(vp)) 188 softdep_setup_allocdirect(ip, lbn, 189 dofftofsb(fs, bp->b_bio2.bio_offset), 190 nb, nsize, osize, bp); 191 } 192 } else { 193 if (ip->i_size < smalllblktosize(fs, lbn + 1)) 194 nsize = fragroundup(fs, size); 195 else 196 nsize = fs->fs_bsize; 197 error = ffs_alloc(ip, lbn, 198 ffs_blkpref(ip, lbn, (int)lbn, &ip->i_db[0]), 199 nsize, cred, &newb); 200 if (error) 201 return (error); 202 bp = getblk(vp, lblktodoff(fs, lbn), nsize, 0, 0); 203 bp->b_bio2.bio_offset = fsbtodoff(fs, newb); 204 if (flags & B_CLRBUF) 205 vfs_bio_clrbuf(bp); 206 if (DOINGSOFTDEP(vp)) 207 softdep_setup_allocdirect(ip, lbn, newb, 0, 208 nsize, 0, bp); 209 } 210 ip->i_db[lbn] = dofftofsb(fs, bp->b_bio2.bio_offset); 211 ip->i_flag |= IN_CHANGE | IN_UPDATE; 212 *ap->a_bpp = bp; 213 return (0); 214 } 215 /* 216 * Determine the number of levels of indirection. 217 */ 218 pref = 0; 219 if ((error = ufs_getlbns(vp, lbn, indirs, &num)) != 0) 220 return(error); 221 #ifdef DIAGNOSTIC 222 if (num < 1) 223 panic ("ffs_balloc: ufs_bmaparray returned indirect block"); 224 #endif 225 /* 226 * Get a handle on the data block buffer before working through 227 * indirect blocks to avoid a deadlock between the VM system holding 228 * a locked VM page and issuing a BMAP (which tries to lock the 229 * indirect blocks), and the filesystem holding a locked indirect 230 * block and then trying to read a data block (which tries to lock 231 * the underlying VM pages). 232 */ 233 dbp = getblk(vp, lblktodoff(fs, lbn), fs->fs_bsize, 0, 0); 234 235 /* 236 * Setup undo history 237 */ 238 allocib = NULL; 239 allocblk = allociblk; 240 lbns_remfree = lbns; 241 242 unwindidx = -1; 243 244 /* 245 * Fetch the first indirect block directly from the inode, allocating 246 * one if necessary. 247 */ 248 --num; 249 nb = ip->i_ib[indirs[0].in_off]; 250 if (nb == 0) { 251 pref = ffs_blkpref(ip, lbn, 0, NULL); 252 /* 253 * If the filesystem has run out of space we can skip the 254 * full fsync/undo of the main [fail] case since no undo 255 * history has been built yet. Hence the goto fail2. 256 */ 257 if ((error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, 258 cred, &newb)) != 0) 259 goto fail2; 260 nb = newb; 261 *allocblk++ = nb; 262 *lbns_remfree++ = indirs[1].in_lbn; 263 bp = getblk(vp, lblktodoff(fs, indirs[1].in_lbn), 264 fs->fs_bsize, 0, 0); 265 bp->b_bio2.bio_offset = fsbtodoff(fs, nb); 266 vfs_bio_clrbuf(bp); 267 if (DOINGSOFTDEP(vp)) { 268 softdep_setup_allocdirect(ip, 269 UFS_NDADDR + indirs[0].in_off, 270 newb, 0, fs->fs_bsize, 0, bp); 271 bdwrite(bp); 272 } else { 273 /* 274 * Write synchronously so that indirect blocks 275 * never point at garbage. 276 */ 277 if (DOINGASYNC(vp)) 278 bdwrite(bp); 279 else if ((error = bwrite(bp)) != 0) 280 goto fail; 281 } 282 allocib = &ip->i_ib[indirs[0].in_off]; 283 *allocib = nb; 284 ip->i_flag |= IN_CHANGE | IN_UPDATE; 285 } 286 287 /* 288 * Fetch through the indirect blocks, allocating as necessary. 289 */ 290 for (i = 1;;) { 291 error = bread(vp, lblktodoff(fs, indirs[i].in_lbn), (int)fs->fs_bsize, &bp); 292 if (error) { 293 brelse(bp); 294 goto fail; 295 } 296 bap = (ufs_daddr_t *)bp->b_data; 297 nb = bap[indirs[i].in_off]; 298 if (i == num) 299 break; 300 i += 1; 301 if (nb != 0) { 302 bqrelse(bp); 303 continue; 304 } 305 if (pref == 0) 306 pref = ffs_blkpref(ip, lbn, 0, NULL); 307 if ((error = 308 ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, cred, &newb)) != 0) { 309 brelse(bp); 310 goto fail; 311 } 312 nb = newb; 313 *allocblk++ = nb; 314 *lbns_remfree++ = indirs[i].in_lbn; 315 nbp = getblk(vp, lblktodoff(fs, indirs[i].in_lbn), 316 fs->fs_bsize, 0, 0); 317 nbp->b_bio2.bio_offset = fsbtodoff(fs, nb); 318 vfs_bio_clrbuf(nbp); 319 if (DOINGSOFTDEP(vp)) { 320 softdep_setup_allocindir_meta(nbp, ip, bp, 321 indirs[i - 1].in_off, nb); 322 bdwrite(nbp); 323 } else { 324 /* 325 * Write synchronously so that indirect blocks 326 * never point at garbage. 327 */ 328 if ((error = bwrite(nbp)) != 0) { 329 brelse(bp); 330 goto fail; 331 } 332 } 333 bap[indirs[i - 1].in_off] = nb; 334 if (allocib == NULL && unwindidx < 0) 335 unwindidx = i - 1; 336 /* 337 * If required, write synchronously, otherwise use 338 * delayed write. 339 */ 340 if (flags & B_SYNC) { 341 bwrite(bp); 342 } else { 343 if (bp->b_bufsize == fs->fs_bsize) 344 bp->b_flags |= B_CLUSTEROK; 345 bdwrite(bp); 346 } 347 } 348 349 /* 350 * Get the data block, allocating if necessary. We have already 351 * called getblk() on the data block buffer, dbp. If we have to 352 * allocate it and B_CLRBUF has been set the inference is an intention 353 * to zero out the related disk blocks, so we do not have to issue 354 * a read. Instead we simply call vfs_bio_clrbuf(). If B_CLRBUF is 355 * not set the caller intends to overwrite the entire contents of the 356 * buffer and we don't waste time trying to clean up the contents. 357 * 358 * bp references the current indirect block. When allocating, 359 * the block must be updated. 360 */ 361 if (nb == 0) { 362 pref = ffs_blkpref(ip, lbn, indirs[i].in_off, &bap[0]); 363 error = ffs_alloc(ip, 364 lbn, pref, (int)fs->fs_bsize, cred, &newb); 365 if (error) { 366 brelse(bp); 367 goto fail; 368 } 369 nb = newb; 370 *allocblk++ = nb; 371 *lbns_remfree++ = lbn; 372 dbp->b_bio2.bio_offset = fsbtodoff(fs, nb); 373 if (flags & B_CLRBUF) 374 vfs_bio_clrbuf(dbp); 375 if (DOINGSOFTDEP(vp)) 376 softdep_setup_allocindir_page(ip, lbn, bp, 377 indirs[i].in_off, nb, 0, dbp); 378 bap[indirs[i].in_off] = nb; 379 /* 380 * If required, write synchronously, otherwise use 381 * delayed write. 382 */ 383 if (flags & B_SYNC) { 384 bwrite(bp); 385 } else { 386 if (bp->b_bufsize == fs->fs_bsize) 387 bp->b_flags |= B_CLUSTEROK; 388 bdwrite(bp); 389 } 390 *ap->a_bpp = dbp; 391 return (0); 392 } 393 brelse(bp); 394 395 /* 396 * At this point all related indirect blocks have been allocated 397 * if necessary and released. bp is no longer valid. dbp holds 398 * our getblk()'d data block. 399 * 400 * XXX we previously performed a cluster_read operation here. 401 */ 402 if (flags & B_CLRBUF) { 403 /* 404 * If B_CLRBUF is set we must validate the invalid portions 405 * of the buffer. This typically requires a read-before- 406 * write. The strategy call will fill in bio_offset in that 407 * case. 408 * 409 * If we hit this case we do a cluster read if possible 410 * since nearby data blocks are likely to be accessed soon 411 * too. 412 */ 413 if ((dbp->b_flags & B_CACHE) == 0) { 414 bqrelse(dbp); 415 seqcount = (flags & B_SEQMASK) >> B_SEQSHIFT; 416 if (seqcount && 417 (vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) { 418 error = cluster_read(vp, (off_t)ip->i_size, 419 lblktodoff(fs, lbn), 420 (int)fs->fs_bsize, 421 fs->fs_bsize, 422 seqcount * MAXBSIZE, 423 &dbp); 424 } else { 425 error = bread(vp, lblktodoff(fs, lbn), 426 (int)fs->fs_bsize, &dbp); 427 } 428 if (error) 429 goto fail; 430 } else { 431 dbp->b_bio2.bio_offset = fsbtodoff(fs, nb); 432 } 433 } else { 434 /* 435 * If B_CLRBUF is not set the caller intends to overwrite 436 * the entire contents of the buffer. We can simply set 437 * bio_offset and we are done. 438 */ 439 dbp->b_bio2.bio_offset = fsbtodoff(fs, nb); 440 } 441 *ap->a_bpp = dbp; 442 return (0); 443 fail: 444 /* 445 * If we have failed part way through block allocation, we 446 * have to deallocate any indirect blocks that we have allocated. 447 * We have to fsync the file before we start to get rid of all 448 * of its dependencies so that we do not leave them dangling. 449 * We have to sync it at the end so that the soft updates code 450 * does not find any untracked changes. Although this is really 451 * slow, running out of disk space is not expected to be a common 452 * occurence. The error return from fsync is ignored as we already 453 * have an error to return to the user. 454 */ 455 VOP_FSYNC(vp, MNT_WAIT, 0); 456 for (deallocated = 0, blkp = allociblk, lbns_remfree = lbns; 457 blkp < allocblk; blkp++, lbns_remfree++) { 458 /* 459 * We shall not leave the freed blocks on the vnode 460 * buffer object lists. 461 */ 462 bp = getblk(vp, lblktodoff(fs, *lbns_remfree), fs->fs_bsize, 0, 0); 463 bp->b_flags |= (B_INVAL | B_RELBUF); 464 brelse(bp); 465 deallocated += fs->fs_bsize; 466 } 467 468 if (allocib != NULL) { 469 *allocib = 0; 470 } else if (unwindidx >= 0) { 471 int r; 472 473 r = bread(vp, lblktodoff(fs, indirs[unwindidx].in_lbn), (int)fs->fs_bsize, &bp); 474 if (r) { 475 panic("Could not unwind indirect block, error %d", r); 476 brelse(bp); 477 } else { 478 bap = (ufs_daddr_t *)bp->b_data; 479 bap[indirs[unwindidx].in_off] = 0; 480 if (flags & B_SYNC) { 481 bwrite(bp); 482 } else { 483 if (bp->b_bufsize == fs->fs_bsize) 484 bp->b_flags |= B_CLUSTEROK; 485 bdwrite(bp); 486 } 487 } 488 } 489 if (deallocated) { 490 #ifdef QUOTA 491 /* 492 * Restore user's disk quota because allocation failed. 493 */ 494 (void) ufs_chkdq(ip, (long)-btodb(deallocated), cred, FORCE); 495 #endif 496 ip->i_blocks -= btodb(deallocated); 497 ip->i_flag |= IN_CHANGE | IN_UPDATE; 498 } 499 VOP_FSYNC(vp, MNT_WAIT, 0); 500 501 /* 502 * After the buffers are invalidated and on-disk pointers are 503 * cleared, free the blocks. 504 */ 505 for (blkp = allociblk; blkp < allocblk; blkp++) { 506 ffs_blkfree(ip, *blkp, fs->fs_bsize); 507 } 508 509 /* 510 * Cleanup the data block we getblk()'d before returning. 511 */ 512 fail2: 513 brelse(dbp); 514 return (error); 515 } 516 517