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 1.18 2006/08/12 00:26:21 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 int unwindidx; 78 int seqcount; 79 80 vp = ap->a_vp; 81 ip = VTOI(vp); 82 fs = ip->i_fs; 83 lbn = lblkno(fs, ap->a_startoffset); 84 size = blkoff(fs, ap->a_startoffset) + ap->a_size; 85 if (size > fs->fs_bsize) 86 panic("ffs_balloc: blk too big"); 87 *ap->a_bpp = NULL; 88 if (lbn < 0) 89 return (EFBIG); 90 cred = ap->a_cred; 91 flags = ap->a_flags; 92 93 /* 94 * The vnode must be locked for us to be able to safely mess 95 * around with the inode. 96 */ 97 if (vn_islocked(vp) != LK_EXCLUSIVE) { 98 panic("ffs_balloc: vnode %p not exclusively locked!", vp); 99 } 100 101 /* 102 * If the next write will extend the file into a new block, 103 * and the file is currently composed of a fragment 104 * this fragment has to be extended to be a full block. 105 */ 106 nb = lblkno(fs, ip->i_size); 107 if (nb < NDADDR && nb < lbn) { 108 /* 109 * The filesize prior to this write can fit in direct 110 * blocks (ex. fragmentation is possibly done) 111 * we are now extending the file write beyond 112 * the block which has end of the file prior to this write. 113 */ 114 osize = blksize(fs, ip, nb); 115 /* 116 * osize gives disk allocated size in the last block. It is 117 * either in fragments or a file system block size. 118 */ 119 if (osize < fs->fs_bsize && osize > 0) { 120 /* A few fragments are already allocated, since the 121 * current extends beyond this block allocated the 122 * complete block as fragments are on in last block. 123 */ 124 error = ffs_realloccg(ip, nb, 125 ffs_blkpref(ip, nb, (int)nb, &ip->i_db[0]), 126 osize, (int)fs->fs_bsize, cred, &bp); 127 if (error) 128 return (error); 129 if (DOINGSOFTDEP(vp)) 130 softdep_setup_allocdirect(ip, nb, 131 dofftofsb(fs, bp->b_bio2.bio_offset), 132 ip->i_db[nb], fs->fs_bsize, osize, bp); 133 /* adjust the inode size, we just grew */ 134 ip->i_size = smalllblktosize(fs, nb + 1); 135 ip->i_db[nb] = dofftofsb(fs, bp->b_bio2.bio_offset); 136 ip->i_flag |= IN_CHANGE | IN_UPDATE; 137 if (flags & B_SYNC) 138 bwrite(bp); 139 else 140 bawrite(bp); 141 /* bp is already released here */ 142 } 143 } 144 /* 145 * The first NDADDR blocks are direct blocks 146 */ 147 if (lbn < NDADDR) { 148 nb = ip->i_db[lbn]; 149 if (nb != 0 && ip->i_size >= smalllblktosize(fs, lbn + 1)) { 150 error = bread(vp, lblktodoff(fs, lbn), fs->fs_bsize, &bp); 151 if (error) { 152 brelse(bp); 153 return (error); 154 } 155 bp->b_bio2.bio_offset = fsbtodoff(fs, nb); 156 *ap->a_bpp = bp; 157 return (0); 158 } 159 if (nb != 0) { 160 /* 161 * Consider need to reallocate a fragment. 162 */ 163 osize = fragroundup(fs, blkoff(fs, ip->i_size)); 164 nsize = fragroundup(fs, size); 165 if (nsize <= osize) { 166 error = bread(vp, lblktodoff(fs, lbn), 167 osize, &bp); 168 if (error) { 169 brelse(bp); 170 return (error); 171 } 172 bp->b_bio2.bio_offset = fsbtodoff(fs, nb); 173 } else { 174 error = ffs_realloccg(ip, lbn, 175 ffs_blkpref(ip, lbn, (int)lbn, 176 &ip->i_db[0]), osize, nsize, cred, &bp); 177 if (error) 178 return (error); 179 if (DOINGSOFTDEP(vp)) 180 softdep_setup_allocdirect(ip, lbn, 181 dofftofsb(fs, bp->b_bio2.bio_offset), 182 nb, nsize, osize, bp); 183 } 184 } else { 185 if (ip->i_size < smalllblktosize(fs, lbn + 1)) 186 nsize = fragroundup(fs, size); 187 else 188 nsize = fs->fs_bsize; 189 error = ffs_alloc(ip, lbn, 190 ffs_blkpref(ip, lbn, (int)lbn, &ip->i_db[0]), 191 nsize, cred, &newb); 192 if (error) 193 return (error); 194 bp = getblk(vp, lblktodoff(fs, lbn), nsize, 0, 0); 195 bp->b_bio2.bio_offset = fsbtodoff(fs, newb); 196 if (flags & B_CLRBUF) 197 vfs_bio_clrbuf(bp); 198 if (DOINGSOFTDEP(vp)) 199 softdep_setup_allocdirect(ip, lbn, newb, 0, 200 nsize, 0, bp); 201 } 202 ip->i_db[lbn] = dofftofsb(fs, bp->b_bio2.bio_offset); 203 ip->i_flag |= IN_CHANGE | IN_UPDATE; 204 *ap->a_bpp = bp; 205 return (0); 206 } 207 /* 208 * Determine the number of levels of indirection. 209 */ 210 pref = 0; 211 if ((error = ufs_getlbns(vp, lbn, indirs, &num)) != 0) 212 return(error); 213 #ifdef DIAGNOSTIC 214 if (num < 1) 215 panic ("ffs_balloc: ufs_bmaparray returned indirect block"); 216 #endif 217 /* 218 * Get a handle on the data block buffer before working through 219 * indirect blocks to avoid a deadlock between the VM system holding 220 * a locked VM page and issuing a BMAP (which tries to lock the 221 * indirect blocks), and the filesystem holding a locked indirect 222 * block and then trying to read a data block (which tries to lock 223 * the underlying VM pages). 224 */ 225 dbp = getblk(vp, lblktodoff(fs, lbn), fs->fs_bsize, 0, 0); 226 227 /* 228 * Setup undo history 229 */ 230 allocib = NULL; 231 allocblk = allociblk; 232 unwindidx = -1; 233 234 /* 235 * Fetch the first indirect block directly from the inode, allocating 236 * one if necessary. 237 */ 238 --num; 239 nb = ip->i_ib[indirs[0].in_off]; 240 if (nb == 0) { 241 pref = ffs_blkpref(ip, lbn, 0, (ufs_daddr_t *)0); 242 /* 243 * If the filesystem has run out of space we can skip the 244 * full fsync/undo of the main [fail] case since no undo 245 * history has been built yet. Hence the goto fail2. 246 */ 247 if ((error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, 248 cred, &newb)) != 0) 249 goto fail2; 250 nb = newb; 251 *allocblk++ = nb; 252 bp = getblk(vp, lblktodoff(fs, indirs[1].in_lbn), 253 fs->fs_bsize, 0, 0); 254 bp->b_bio2.bio_offset = fsbtodoff(fs, nb); 255 vfs_bio_clrbuf(bp); 256 if (DOINGSOFTDEP(vp)) { 257 softdep_setup_allocdirect(ip, NDADDR + indirs[0].in_off, 258 newb, 0, fs->fs_bsize, 0, bp); 259 bdwrite(bp); 260 } else { 261 /* 262 * Write synchronously so that indirect blocks 263 * never point at garbage. 264 */ 265 if (DOINGASYNC(vp)) 266 bdwrite(bp); 267 else if ((error = bwrite(bp)) != 0) 268 goto fail; 269 } 270 allocib = &ip->i_ib[indirs[0].in_off]; 271 *allocib = nb; 272 ip->i_flag |= IN_CHANGE | IN_UPDATE; 273 } 274 275 /* 276 * Fetch through the indirect blocks, allocating as necessary. 277 */ 278 for (i = 1;;) { 279 error = bread(vp, lblktodoff(fs, indirs[i].in_lbn), (int)fs->fs_bsize, &bp); 280 if (error) { 281 brelse(bp); 282 goto fail; 283 } 284 bap = (ufs_daddr_t *)bp->b_data; 285 nb = bap[indirs[i].in_off]; 286 if (i == num) 287 break; 288 i += 1; 289 if (nb != 0) { 290 bqrelse(bp); 291 continue; 292 } 293 if (pref == 0) 294 pref = ffs_blkpref(ip, lbn, 0, (ufs_daddr_t *)0); 295 if ((error = 296 ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, cred, &newb)) != 0) { 297 brelse(bp); 298 goto fail; 299 } 300 nb = newb; 301 *allocblk++ = nb; 302 nbp = getblk(vp, lblktodoff(fs, indirs[i].in_lbn), 303 fs->fs_bsize, 0, 0); 304 nbp->b_bio2.bio_offset = fsbtodoff(fs, nb); 305 vfs_bio_clrbuf(nbp); 306 if (DOINGSOFTDEP(vp)) { 307 softdep_setup_allocindir_meta(nbp, ip, bp, 308 indirs[i - 1].in_off, nb); 309 bdwrite(nbp); 310 } else { 311 /* 312 * Write synchronously so that indirect blocks 313 * never point at garbage. 314 */ 315 if ((error = bwrite(nbp)) != 0) { 316 brelse(bp); 317 goto fail; 318 } 319 } 320 bap[indirs[i - 1].in_off] = nb; 321 if (allocib == NULL && unwindidx < 0) 322 unwindidx = i - 1; 323 /* 324 * If required, write synchronously, otherwise use 325 * delayed write. 326 */ 327 if (flags & B_SYNC) { 328 bwrite(bp); 329 } else { 330 if (bp->b_bufsize == fs->fs_bsize) 331 bp->b_flags |= B_CLUSTEROK; 332 bdwrite(bp); 333 } 334 } 335 336 /* 337 * Get the data block, allocating if necessary. We have already 338 * called getblk() on the data block buffer, dbp. If we have to 339 * allocate it and B_CLRBUF has been set the inference is an intention 340 * to zero out the related disk blocks, so we do not have to issue 341 * a read. Instead we simply call vfs_bio_clrbuf(). If B_CLRBUF is 342 * not set the caller intends to overwrite the entire contents of the 343 * buffer and we don't waste time trying to clean up the contents. 344 * 345 * bp references the current indirect block. When allocating, 346 * the block must be updated. 347 */ 348 if (nb == 0) { 349 pref = ffs_blkpref(ip, lbn, indirs[i].in_off, &bap[0]); 350 error = ffs_alloc(ip, 351 lbn, pref, (int)fs->fs_bsize, cred, &newb); 352 if (error) { 353 brelse(bp); 354 goto fail; 355 } 356 nb = newb; 357 *allocblk++ = nb; 358 dbp->b_bio2.bio_offset = fsbtodoff(fs, nb); 359 if (flags & B_CLRBUF) 360 vfs_bio_clrbuf(dbp); 361 if (DOINGSOFTDEP(vp)) 362 softdep_setup_allocindir_page(ip, lbn, bp, 363 indirs[i].in_off, nb, 0, dbp); 364 bap[indirs[i].in_off] = nb; 365 /* 366 * If required, write synchronously, otherwise use 367 * delayed write. 368 */ 369 if (flags & B_SYNC) { 370 bwrite(bp); 371 } else { 372 if (bp->b_bufsize == fs->fs_bsize) 373 bp->b_flags |= B_CLUSTEROK; 374 bdwrite(bp); 375 } 376 *ap->a_bpp = dbp; 377 return (0); 378 } 379 brelse(bp); 380 381 /* 382 * At this point all related indirect blocks have been allocated 383 * if necessary and released. bp is no longer valid. dbp holds 384 * our getblk()'d data block. 385 * 386 * XXX we previously performed a cluster_read operation here. 387 */ 388 if (flags & B_CLRBUF) { 389 /* 390 * If B_CLRBUF is set we must validate the invalid portions 391 * of the buffer. This typically requires a read-before- 392 * write. The strategy call will fill in bio_offset in that 393 * case. 394 * 395 * If we hit this case we do a cluster read if possible 396 * since nearby data blocks are likely to be accessed soon 397 * too. 398 */ 399 if ((dbp->b_flags & B_CACHE) == 0) { 400 bqrelse(dbp); 401 seqcount = (flags & B_SEQMASK) >> B_SEQSHIFT; 402 if (seqcount && 403 (vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) { 404 error = cluster_read(vp, (off_t)ip->i_size, 405 lblktodoff(fs, lbn), 406 (int)fs->fs_bsize, 407 MAXBSIZE, seqcount, &dbp); 408 } else { 409 error = bread(vp, lblktodoff(fs, lbn), (int)fs->fs_bsize, &dbp); 410 } 411 if (error) 412 goto fail; 413 } else { 414 dbp->b_bio2.bio_offset = fsbtodoff(fs, nb); 415 } 416 } else { 417 /* 418 * If B_CLRBUF is not set the caller intends to overwrite 419 * the entire contents of the buffer. We can simply set 420 * bio_offset and we are done. 421 */ 422 dbp->b_bio2.bio_offset = fsbtodoff(fs, nb); 423 } 424 *ap->a_bpp = dbp; 425 return (0); 426 fail: 427 /* 428 * If we have failed part way through block allocation, we 429 * have to deallocate any indirect blocks that we have allocated. 430 * We have to fsync the file before we start to get rid of all 431 * of its dependencies so that we do not leave them dangling. 432 * We have to sync it at the end so that the soft updates code 433 * does not find any untracked changes. Although this is really 434 * slow, running out of disk space is not expected to be a common 435 * occurence. The error return from fsync is ignored as we already 436 * have an error to return to the user. 437 */ 438 (void) VOP_FSYNC(vp, MNT_WAIT); 439 for (deallocated = 0, blkp = allociblk; blkp < allocblk; blkp++) { 440 ffs_blkfree(ip, *blkp, fs->fs_bsize); 441 deallocated += fs->fs_bsize; 442 } 443 if (allocib != NULL) { 444 *allocib = 0; 445 } else if (unwindidx >= 0) { 446 int r; 447 448 r = bread(vp, lblktodoff(fs, indirs[unwindidx].in_lbn), (int)fs->fs_bsize, &bp); 449 if (r) { 450 panic("Could not unwind indirect block, error %d", r); 451 brelse(bp); 452 } else { 453 bap = (ufs_daddr_t *)bp->b_data; 454 bap[indirs[unwindidx].in_off] = 0; 455 if (flags & B_SYNC) { 456 bwrite(bp); 457 } else { 458 if (bp->b_bufsize == fs->fs_bsize) 459 bp->b_flags |= B_CLUSTEROK; 460 bdwrite(bp); 461 } 462 } 463 } 464 if (deallocated) { 465 #ifdef QUOTA 466 /* 467 * Restore user's disk quota because allocation failed. 468 */ 469 (void) ufs_chkdq(ip, (long)-btodb(deallocated), cred, FORCE); 470 #endif 471 ip->i_blocks -= btodb(deallocated); 472 ip->i_flag |= IN_CHANGE | IN_UPDATE; 473 } 474 (void) VOP_FSYNC(vp, MNT_WAIT); 475 476 /* 477 * Cleanup the data block we getblk()'d before returning. 478 */ 479 fail2: 480 brelse(dbp); 481 return (error); 482 } 483 484