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1 /*

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