1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright 2000 Marshall Kirk McKusick. All Rights Reserved. 5 * 6 * Further information about snapshots can be obtained from: 7 * 8 * Marshall Kirk McKusick http://www.mckusick.com/softdep/ 9 * 1614 Oxford Street mckusick@mckusick.com 10 * Berkeley, CA 94709-1608 +1-510-843-9542 11 * USA 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 23 * THIS SOFTWARE IS PROVIDED BY MARSHALL KIRK MCKUSICK ``AS IS'' AND ANY 24 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 25 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 26 * DISCLAIMED. IN NO EVENT SHALL MARSHALL KIRK MCKUSICK BE LIABLE FOR 27 * 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_snapshot.c 8.11 (McKusick) 7/23/00 36 */ 37 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include "opt_quota.h" 42 43 #include <sys/param.h> 44 #include <sys/kernel.h> 45 #include <sys/systm.h> 46 #include <sys/conf.h> 47 #include <sys/bio.h> 48 #include <sys/buf.h> 49 #include <sys/fcntl.h> 50 #include <sys/proc.h> 51 #include <sys/namei.h> 52 #include <sys/sched.h> 53 #include <sys/stat.h> 54 #include <sys/malloc.h> 55 #include <sys/mount.h> 56 #include <sys/resource.h> 57 #include <sys/resourcevar.h> 58 #include <sys/rwlock.h> 59 #include <sys/vnode.h> 60 61 #include <geom/geom.h> 62 63 #include <ufs/ufs/extattr.h> 64 #include <ufs/ufs/quota.h> 65 #include <ufs/ufs/ufsmount.h> 66 #include <ufs/ufs/inode.h> 67 #include <ufs/ufs/ufs_extern.h> 68 69 #include <ufs/ffs/fs.h> 70 #include <ufs/ffs/ffs_extern.h> 71 72 #define KERNCRED thread0.td_ucred 73 #define DEBUG 1 74 75 #include "opt_ffs.h" 76 77 #ifdef NO_FFS_SNAPSHOT 78 int 79 ffs_snapshot(mp, snapfile) 80 struct mount *mp; 81 char *snapfile; 82 { 83 return (EINVAL); 84 } 85 86 int 87 ffs_snapblkfree(fs, devvp, bno, size, inum, vtype, wkhd) 88 struct fs *fs; 89 struct vnode *devvp; 90 ufs2_daddr_t bno; 91 long size; 92 ino_t inum; 93 enum vtype vtype; 94 struct workhead *wkhd; 95 { 96 return (EINVAL); 97 } 98 99 void 100 ffs_snapremove(vp) 101 struct vnode *vp; 102 { 103 } 104 105 void 106 ffs_snapshot_mount(mp) 107 struct mount *mp; 108 { 109 } 110 111 void 112 ffs_snapshot_unmount(mp) 113 struct mount *mp; 114 { 115 } 116 117 void 118 ffs_snapgone(ip) 119 struct inode *ip; 120 { 121 } 122 123 int 124 ffs_copyonwrite(devvp, bp) 125 struct vnode *devvp; 126 struct buf *bp; 127 { 128 return (EINVAL); 129 } 130 131 void 132 ffs_sync_snap(mp, waitfor) 133 struct mount *mp; 134 int waitfor; 135 { 136 } 137 138 #else 139 FEATURE(ffs_snapshot, "FFS snapshot support"); 140 141 LIST_HEAD(, snapdata) snapfree; 142 static struct mtx snapfree_lock; 143 MTX_SYSINIT(ffs_snapfree, &snapfree_lock, "snapdata free list", MTX_DEF); 144 145 static int cgaccount(int, struct vnode *, struct buf *, int); 146 static int expunge_ufs1(struct vnode *, struct inode *, struct fs *, 147 int (*)(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, struct fs *, 148 ufs_lbn_t, int), int, int); 149 static int indiracct_ufs1(struct vnode *, struct vnode *, int, 150 ufs1_daddr_t, ufs_lbn_t, ufs_lbn_t, ufs_lbn_t, ufs_lbn_t, struct fs *, 151 int (*)(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, struct fs *, 152 ufs_lbn_t, int), int); 153 static int fullacct_ufs1(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, 154 struct fs *, ufs_lbn_t, int); 155 static int snapacct_ufs1(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, 156 struct fs *, ufs_lbn_t, int); 157 static int mapacct_ufs1(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, 158 struct fs *, ufs_lbn_t, int); 159 static int expunge_ufs2(struct vnode *, struct inode *, struct fs *, 160 int (*)(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, struct fs *, 161 ufs_lbn_t, int), int, int); 162 static int indiracct_ufs2(struct vnode *, struct vnode *, int, 163 ufs2_daddr_t, ufs_lbn_t, ufs_lbn_t, ufs_lbn_t, ufs_lbn_t, struct fs *, 164 int (*)(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, struct fs *, 165 ufs_lbn_t, int), int); 166 static int fullacct_ufs2(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, 167 struct fs *, ufs_lbn_t, int); 168 static int snapacct_ufs2(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, 169 struct fs *, ufs_lbn_t, int); 170 static int mapacct_ufs2(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, 171 struct fs *, ufs_lbn_t, int); 172 static int readblock(struct vnode *vp, struct buf *, ufs2_daddr_t); 173 static void try_free_snapdata(struct vnode *devvp); 174 static struct snapdata *ffs_snapdata_acquire(struct vnode *devvp); 175 static int ffs_bp_snapblk(struct vnode *, struct buf *); 176 177 /* 178 * To ensure the consistency of snapshots across crashes, we must 179 * synchronously write out copied blocks before allowing the 180 * originals to be modified. Because of the rather severe speed 181 * penalty that this imposes, the code normally only ensures 182 * persistence for the filesystem metadata contained within a 183 * snapshot. Setting the following flag allows this crash 184 * persistence to be enabled for file contents. 185 */ 186 int dopersistence = 0; 187 188 #ifdef DEBUG 189 #include <sys/sysctl.h> 190 SYSCTL_INT(_debug, OID_AUTO, dopersistence, CTLFLAG_RW, &dopersistence, 0, ""); 191 static int snapdebug = 0; 192 SYSCTL_INT(_debug, OID_AUTO, snapdebug, CTLFLAG_RW, &snapdebug, 0, ""); 193 int collectsnapstats = 0; 194 SYSCTL_INT(_debug, OID_AUTO, collectsnapstats, CTLFLAG_RW, &collectsnapstats, 195 0, ""); 196 #endif /* DEBUG */ 197 198 /* 199 * Create a snapshot file and initialize it for the filesystem. 200 */ 201 int 202 ffs_snapshot(mp, snapfile) 203 struct mount *mp; 204 char *snapfile; 205 { 206 ufs2_daddr_t numblks, blkno, *blkp, *snapblklist; 207 int error, cg, snaploc; 208 int i, size, len, loc; 209 ufs2_daddr_t blockno; 210 uint64_t flag; 211 struct timespec starttime = {0, 0}, endtime; 212 char saved_nice = 0; 213 long redo = 0, snaplistsize = 0; 214 int32_t *lp; 215 void *space; 216 struct fs *copy_fs = NULL, *fs; 217 struct thread *td = curthread; 218 struct inode *ip, *xp; 219 struct buf *bp, *nbp, *ibp; 220 struct nameidata nd; 221 struct mount *wrtmp; 222 struct vattr vat; 223 struct vnode *vp, *xvp, *mvp, *devvp; 224 struct uio auio; 225 struct iovec aiov; 226 struct snapdata *sn; 227 struct ufsmount *ump; 228 229 ump = VFSTOUFS(mp); 230 fs = ump->um_fs; 231 sn = NULL; 232 /* 233 * At the moment, journaled soft updates cannot support 234 * taking snapshots. 235 */ 236 if (MOUNTEDSUJ(mp)) { 237 vfs_mount_error(mp, "%s: Snapshots are not yet supported when " 238 "running with journaled soft updates", fs->fs_fsmnt); 239 return (EOPNOTSUPP); 240 } 241 MNT_ILOCK(mp); 242 flag = mp->mnt_flag; 243 MNT_IUNLOCK(mp); 244 /* 245 * Need to serialize access to snapshot code per filesystem. 246 */ 247 /* 248 * Assign a snapshot slot in the superblock. 249 */ 250 UFS_LOCK(ump); 251 for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++) 252 if (fs->fs_snapinum[snaploc] == 0) 253 break; 254 UFS_UNLOCK(ump); 255 if (snaploc == FSMAXSNAP) 256 return (ENOSPC); 257 /* 258 * Create the snapshot file. 259 */ 260 restart: 261 NDINIT(&nd, CREATE, LOCKPARENT | LOCKLEAF | NOCACHE, UIO_SYSSPACE, 262 snapfile, td); 263 if ((error = namei(&nd)) != 0) 264 return (error); 265 if (nd.ni_vp != NULL) { 266 vput(nd.ni_vp); 267 error = EEXIST; 268 } 269 if (nd.ni_dvp->v_mount != mp) 270 error = EXDEV; 271 if (error) { 272 NDFREE(&nd, NDF_ONLY_PNBUF); 273 if (nd.ni_dvp == nd.ni_vp) 274 vrele(nd.ni_dvp); 275 else 276 vput(nd.ni_dvp); 277 return (error); 278 } 279 VATTR_NULL(&vat); 280 vat.va_type = VREG; 281 vat.va_mode = S_IRUSR; 282 vat.va_vaflags |= VA_EXCLUSIVE; 283 if (VOP_GETWRITEMOUNT(nd.ni_dvp, &wrtmp)) 284 wrtmp = NULL; 285 if (wrtmp != mp) 286 panic("ffs_snapshot: mount mismatch"); 287 vfs_rel(wrtmp); 288 if (vn_start_write(NULL, &wrtmp, V_NOWAIT) != 0) { 289 NDFREE(&nd, NDF_ONLY_PNBUF); 290 vput(nd.ni_dvp); 291 if ((error = vn_start_write(NULL, &wrtmp, 292 V_XSLEEP | PCATCH)) != 0) 293 return (error); 294 goto restart; 295 } 296 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vat); 297 VOP_UNLOCK(nd.ni_dvp, 0); 298 if (error) { 299 NDFREE(&nd, NDF_ONLY_PNBUF); 300 vn_finished_write(wrtmp); 301 vrele(nd.ni_dvp); 302 return (error); 303 } 304 vp = nd.ni_vp; 305 vp->v_vflag |= VV_SYSTEM; 306 ip = VTOI(vp); 307 devvp = ITODEVVP(ip); 308 /* 309 * Allocate and copy the last block contents so as to be able 310 * to set size to that of the filesystem. 311 */ 312 numblks = howmany(fs->fs_size, fs->fs_frag); 313 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(numblks - 1)), 314 fs->fs_bsize, KERNCRED, BA_CLRBUF, &bp); 315 if (error) 316 goto out; 317 ip->i_size = lblktosize(fs, (off_t)numblks); 318 DIP_SET(ip, i_size, ip->i_size); 319 ip->i_flag |= IN_CHANGE | IN_UPDATE; 320 error = readblock(vp, bp, numblks - 1); 321 bawrite(bp); 322 if (error != 0) 323 goto out; 324 /* 325 * Preallocate critical data structures so that we can copy 326 * them in without further allocation after we suspend all 327 * operations on the filesystem. We would like to just release 328 * the allocated buffers without writing them since they will 329 * be filled in below once we are ready to go, but this upsets 330 * the soft update code, so we go ahead and write the new buffers. 331 * 332 * Allocate all indirect blocks and mark all of them as not 333 * needing to be copied. 334 */ 335 for (blkno = UFS_NDADDR; blkno < numblks; blkno += NINDIR(fs)) { 336 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)blkno), 337 fs->fs_bsize, td->td_ucred, BA_METAONLY, &ibp); 338 if (error) 339 goto out; 340 bawrite(ibp); 341 } 342 /* 343 * Allocate copies for the superblock and its summary information. 344 */ 345 error = UFS_BALLOC(vp, fs->fs_sblockloc, fs->fs_sbsize, KERNCRED, 346 0, &nbp); 347 if (error) 348 goto out; 349 bawrite(nbp); 350 blkno = fragstoblks(fs, fs->fs_csaddr); 351 len = howmany(fs->fs_cssize, fs->fs_bsize); 352 for (loc = 0; loc < len; loc++) { 353 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(blkno + loc)), 354 fs->fs_bsize, KERNCRED, 0, &nbp); 355 if (error) 356 goto out; 357 bawrite(nbp); 358 } 359 /* 360 * Allocate all cylinder group blocks. 361 */ 362 for (cg = 0; cg < fs->fs_ncg; cg++) { 363 error = UFS_BALLOC(vp, lfragtosize(fs, cgtod(fs, cg)), 364 fs->fs_bsize, KERNCRED, 0, &nbp); 365 if (error) 366 goto out; 367 bawrite(nbp); 368 if (cg % 10 == 0) 369 ffs_syncvnode(vp, MNT_WAIT, 0); 370 } 371 /* 372 * Copy all the cylinder group maps. Although the 373 * filesystem is still active, we hope that only a few 374 * cylinder groups will change between now and when we 375 * suspend operations. Thus, we will be able to quickly 376 * touch up the few cylinder groups that changed during 377 * the suspension period. 378 */ 379 len = howmany(fs->fs_ncg, NBBY); 380 space = malloc(len, M_DEVBUF, M_WAITOK|M_ZERO); 381 UFS_LOCK(ump); 382 fs->fs_active = space; 383 UFS_UNLOCK(ump); 384 for (cg = 0; cg < fs->fs_ncg; cg++) { 385 error = UFS_BALLOC(vp, lfragtosize(fs, cgtod(fs, cg)), 386 fs->fs_bsize, KERNCRED, 0, &nbp); 387 if (error) 388 goto out; 389 error = cgaccount(cg, vp, nbp, 1); 390 bawrite(nbp); 391 if (cg % 10 == 0) 392 ffs_syncvnode(vp, MNT_WAIT, 0); 393 if (error) 394 goto out; 395 } 396 /* 397 * Change inode to snapshot type file. 398 */ 399 ip->i_flags |= SF_SNAPSHOT; 400 DIP_SET(ip, i_flags, ip->i_flags); 401 ip->i_flag |= IN_CHANGE | IN_UPDATE; 402 /* 403 * Ensure that the snapshot is completely on disk. 404 * Since we have marked it as a snapshot it is safe to 405 * unlock it as no process will be allowed to write to it. 406 */ 407 if ((error = ffs_syncvnode(vp, MNT_WAIT, 0)) != 0) 408 goto out; 409 VOP_UNLOCK(vp, 0); 410 /* 411 * All allocations are done, so we can now snapshot the system. 412 * 413 * Recind nice scheduling while running with the filesystem suspended. 414 */ 415 if (td->td_proc->p_nice > 0) { 416 struct proc *p; 417 418 p = td->td_proc; 419 PROC_LOCK(p); 420 saved_nice = p->p_nice; 421 sched_nice(p, 0); 422 PROC_UNLOCK(p); 423 } 424 /* 425 * Suspend operation on filesystem. 426 */ 427 for (;;) { 428 vn_finished_write(wrtmp); 429 if ((error = vfs_write_suspend(vp->v_mount, 0)) != 0) { 430 vn_start_write(NULL, &wrtmp, V_WAIT); 431 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 432 goto out; 433 } 434 if (mp->mnt_kern_flag & MNTK_SUSPENDED) 435 break; 436 vn_start_write(NULL, &wrtmp, V_WAIT); 437 } 438 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 439 if (ip->i_effnlink == 0) { 440 error = ENOENT; /* Snapshot file unlinked */ 441 goto out1; 442 } 443 if (collectsnapstats) 444 nanotime(&starttime); 445 446 /* The last block might have changed. Copy it again to be sure. */ 447 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(numblks - 1)), 448 fs->fs_bsize, KERNCRED, BA_CLRBUF, &bp); 449 if (error != 0) 450 goto out1; 451 error = readblock(vp, bp, numblks - 1); 452 bp->b_flags |= B_VALIDSUSPWRT; 453 bawrite(bp); 454 if (error != 0) 455 goto out1; 456 /* 457 * First, copy all the cylinder group maps that have changed. 458 */ 459 for (cg = 0; cg < fs->fs_ncg; cg++) { 460 if ((ACTIVECGNUM(fs, cg) & ACTIVECGOFF(cg)) != 0) 461 continue; 462 redo++; 463 error = UFS_BALLOC(vp, lfragtosize(fs, cgtod(fs, cg)), 464 fs->fs_bsize, KERNCRED, 0, &nbp); 465 if (error) 466 goto out1; 467 error = cgaccount(cg, vp, nbp, 2); 468 bawrite(nbp); 469 if (error) 470 goto out1; 471 } 472 /* 473 * Grab a copy of the superblock and its summary information. 474 * We delay writing it until the suspension is released below. 475 */ 476 copy_fs = malloc((u_long)fs->fs_bsize, M_UFSMNT, M_WAITOK); 477 bcopy(fs, copy_fs, fs->fs_sbsize); 478 if ((fs->fs_flags & (FS_UNCLEAN | FS_NEEDSFSCK)) == 0) 479 copy_fs->fs_clean = 1; 480 size = fs->fs_bsize < SBLOCKSIZE ? fs->fs_bsize : SBLOCKSIZE; 481 if (fs->fs_sbsize < size) 482 bzero(&((char *)copy_fs)[fs->fs_sbsize], 483 size - fs->fs_sbsize); 484 size = blkroundup(fs, fs->fs_cssize); 485 if (fs->fs_contigsumsize > 0) 486 size += fs->fs_ncg * sizeof(int32_t); 487 space = malloc((u_long)size, M_UFSMNT, M_WAITOK); 488 copy_fs->fs_csp = space; 489 bcopy(fs->fs_csp, copy_fs->fs_csp, fs->fs_cssize); 490 space = (char *)space + fs->fs_cssize; 491 loc = howmany(fs->fs_cssize, fs->fs_fsize); 492 i = fs->fs_frag - loc % fs->fs_frag; 493 len = (i == fs->fs_frag) ? 0 : i * fs->fs_fsize; 494 if (len > 0) { 495 if ((error = bread(devvp, fsbtodb(fs, fs->fs_csaddr + loc), 496 len, KERNCRED, &bp)) != 0) { 497 brelse(bp); 498 free(copy_fs->fs_csp, M_UFSMNT); 499 free(copy_fs, M_UFSMNT); 500 copy_fs = NULL; 501 goto out1; 502 } 503 bcopy(bp->b_data, space, (u_int)len); 504 space = (char *)space + len; 505 bp->b_flags |= B_INVAL | B_NOCACHE; 506 brelse(bp); 507 } 508 if (fs->fs_contigsumsize > 0) { 509 copy_fs->fs_maxcluster = lp = space; 510 for (i = 0; i < fs->fs_ncg; i++) 511 *lp++ = fs->fs_contigsumsize; 512 } 513 /* 514 * We must check for active files that have been unlinked 515 * (e.g., with a zero link count). We have to expunge all 516 * trace of these files from the snapshot so that they are 517 * not reclaimed prematurely by fsck or unnecessarily dumped. 518 * We turn off the MNTK_SUSPENDED flag to avoid a panic from 519 * spec_strategy about writing on a suspended filesystem. 520 * Note that we skip unlinked snapshot files as they will 521 * be handled separately below. 522 * 523 * We also calculate the needed size for the snapshot list. 524 */ 525 snaplistsize = fs->fs_ncg + howmany(fs->fs_cssize, fs->fs_bsize) + 526 FSMAXSNAP + 1 /* superblock */ + 1 /* last block */ + 1 /* size */; 527 MNT_ILOCK(mp); 528 mp->mnt_kern_flag &= ~MNTK_SUSPENDED; 529 MNT_IUNLOCK(mp); 530 loop: 531 MNT_VNODE_FOREACH_ALL(xvp, mp, mvp) { 532 if ((xvp->v_usecount == 0 && 533 (xvp->v_iflag & (VI_OWEINACT | VI_DOINGINACT)) == 0) || 534 xvp->v_type == VNON || 535 IS_SNAPSHOT(VTOI(xvp))) { 536 VI_UNLOCK(xvp); 537 continue; 538 } 539 /* 540 * We can skip parent directory vnode because it must have 541 * this snapshot file in it. 542 */ 543 if (xvp == nd.ni_dvp) { 544 VI_UNLOCK(xvp); 545 continue; 546 } 547 vholdl(xvp); 548 if (vn_lock(xvp, LK_EXCLUSIVE | LK_INTERLOCK) != 0) { 549 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 550 vdrop(xvp); 551 goto loop; 552 } 553 VI_LOCK(xvp); 554 if (xvp->v_usecount == 0 && 555 (xvp->v_iflag & (VI_OWEINACT | VI_DOINGINACT)) == 0) { 556 VI_UNLOCK(xvp); 557 VOP_UNLOCK(xvp, 0); 558 vdrop(xvp); 559 continue; 560 } 561 VI_UNLOCK(xvp); 562 if (snapdebug) 563 vn_printf(xvp, "ffs_snapshot: busy vnode "); 564 if (VOP_GETATTR(xvp, &vat, td->td_ucred) == 0 && 565 vat.va_nlink > 0) { 566 VOP_UNLOCK(xvp, 0); 567 vdrop(xvp); 568 continue; 569 } 570 xp = VTOI(xvp); 571 if (ffs_checkfreefile(copy_fs, vp, xp->i_number)) { 572 VOP_UNLOCK(xvp, 0); 573 vdrop(xvp); 574 continue; 575 } 576 /* 577 * If there is a fragment, clear it here. 578 */ 579 blkno = 0; 580 loc = howmany(xp->i_size, fs->fs_bsize) - 1; 581 if (loc < UFS_NDADDR) { 582 len = fragroundup(fs, blkoff(fs, xp->i_size)); 583 if (len != 0 && len < fs->fs_bsize) { 584 ffs_blkfree(ump, copy_fs, vp, 585 DIP(xp, i_db[loc]), len, xp->i_number, 586 xvp->v_type, NULL, SINGLETON_KEY); 587 blkno = DIP(xp, i_db[loc]); 588 DIP_SET(xp, i_db[loc], 0); 589 } 590 } 591 snaplistsize += 1; 592 if (I_IS_UFS1(xp)) 593 error = expunge_ufs1(vp, xp, copy_fs, fullacct_ufs1, 594 BLK_NOCOPY, 1); 595 else 596 error = expunge_ufs2(vp, xp, copy_fs, fullacct_ufs2, 597 BLK_NOCOPY, 1); 598 if (blkno) 599 DIP_SET(xp, i_db[loc], blkno); 600 if (!error) 601 error = ffs_freefile(ump, copy_fs, vp, xp->i_number, 602 xp->i_mode, NULL); 603 VOP_UNLOCK(xvp, 0); 604 vdrop(xvp); 605 if (error) { 606 free(copy_fs->fs_csp, M_UFSMNT); 607 free(copy_fs, M_UFSMNT); 608 copy_fs = NULL; 609 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 610 goto out1; 611 } 612 } 613 /* 614 * Erase the journal file from the snapshot. 615 */ 616 if (fs->fs_flags & FS_SUJ) { 617 error = softdep_journal_lookup(mp, &xvp); 618 if (error) { 619 free(copy_fs->fs_csp, M_UFSMNT); 620 free(copy_fs, M_UFSMNT); 621 copy_fs = NULL; 622 goto out1; 623 } 624 xp = VTOI(xvp); 625 if (I_IS_UFS1(xp)) 626 error = expunge_ufs1(vp, xp, copy_fs, fullacct_ufs1, 627 BLK_NOCOPY, 0); 628 else 629 error = expunge_ufs2(vp, xp, copy_fs, fullacct_ufs2, 630 BLK_NOCOPY, 0); 631 vput(xvp); 632 } 633 /* 634 * Acquire a lock on the snapdata structure, creating it if necessary. 635 */ 636 sn = ffs_snapdata_acquire(devvp); 637 /* 638 * Change vnode to use shared snapshot lock instead of the original 639 * private lock. 640 */ 641 vp->v_vnlock = &sn->sn_lock; 642 lockmgr(&vp->v_lock, LK_RELEASE, NULL); 643 xp = TAILQ_FIRST(&sn->sn_head); 644 /* 645 * If this is the first snapshot on this filesystem, then we need 646 * to allocate the space for the list of preallocated snapshot blocks. 647 * This list will be refined below, but this preliminary one will 648 * keep us out of deadlock until the full one is ready. 649 */ 650 if (xp == NULL) { 651 snapblklist = malloc(snaplistsize * sizeof(daddr_t), 652 M_UFSMNT, M_WAITOK); 653 blkp = &snapblklist[1]; 654 *blkp++ = lblkno(fs, fs->fs_sblockloc); 655 blkno = fragstoblks(fs, fs->fs_csaddr); 656 for (cg = 0; cg < fs->fs_ncg; cg++) { 657 if (fragstoblks(fs, cgtod(fs, cg) > blkno)) 658 break; 659 *blkp++ = fragstoblks(fs, cgtod(fs, cg)); 660 } 661 len = howmany(fs->fs_cssize, fs->fs_bsize); 662 for (loc = 0; loc < len; loc++) 663 *blkp++ = blkno + loc; 664 for (; cg < fs->fs_ncg; cg++) 665 *blkp++ = fragstoblks(fs, cgtod(fs, cg)); 666 snapblklist[0] = blkp - snapblklist; 667 VI_LOCK(devvp); 668 if (sn->sn_blklist != NULL) 669 panic("ffs_snapshot: non-empty list"); 670 sn->sn_blklist = snapblklist; 671 sn->sn_listsize = blkp - snapblklist; 672 VI_UNLOCK(devvp); 673 } 674 /* 675 * Record snapshot inode. Since this is the newest snapshot, 676 * it must be placed at the end of the list. 677 */ 678 VI_LOCK(devvp); 679 fs->fs_snapinum[snaploc] = ip->i_number; 680 if (ip->i_nextsnap.tqe_prev != 0) 681 panic("ffs_snapshot: %ju already on list", 682 (uintmax_t)ip->i_number); 683 TAILQ_INSERT_TAIL(&sn->sn_head, ip, i_nextsnap); 684 devvp->v_vflag |= VV_COPYONWRITE; 685 VI_UNLOCK(devvp); 686 ASSERT_VOP_LOCKED(vp, "ffs_snapshot vp"); 687 out1: 688 KASSERT((sn != NULL && copy_fs != NULL && error == 0) || 689 (sn == NULL && copy_fs == NULL && error != 0), 690 ("email phk@ and mckusick@")); 691 /* 692 * Resume operation on filesystem. 693 */ 694 vfs_write_resume(vp->v_mount, VR_START_WRITE | VR_NO_SUSPCLR); 695 if (collectsnapstats && starttime.tv_sec > 0) { 696 nanotime(&endtime); 697 timespecsub(&endtime, &starttime, &endtime); 698 printf("%s: suspended %ld.%03ld sec, redo %ld of %d\n", 699 vp->v_mount->mnt_stat.f_mntonname, (long)endtime.tv_sec, 700 endtime.tv_nsec / 1000000, redo, fs->fs_ncg); 701 } 702 if (copy_fs == NULL) 703 goto out; 704 /* 705 * Copy allocation information from all the snapshots in 706 * this snapshot and then expunge them from its view. 707 */ 708 TAILQ_FOREACH(xp, &sn->sn_head, i_nextsnap) { 709 if (xp == ip) 710 break; 711 if (I_IS_UFS1(xp)) 712 error = expunge_ufs1(vp, xp, fs, snapacct_ufs1, 713 BLK_SNAP, 0); 714 else 715 error = expunge_ufs2(vp, xp, fs, snapacct_ufs2, 716 BLK_SNAP, 0); 717 if (error == 0 && xp->i_effnlink == 0) { 718 error = ffs_freefile(ump, 719 copy_fs, 720 vp, 721 xp->i_number, 722 xp->i_mode, NULL); 723 } 724 if (error) { 725 fs->fs_snapinum[snaploc] = 0; 726 goto done; 727 } 728 } 729 /* 730 * Allocate space for the full list of preallocated snapshot blocks. 731 */ 732 snapblklist = malloc(snaplistsize * sizeof(daddr_t), 733 M_UFSMNT, M_WAITOK); 734 ip->i_snapblklist = &snapblklist[1]; 735 /* 736 * Expunge the blocks used by the snapshots from the set of 737 * blocks marked as used in the snapshot bitmaps. Also, collect 738 * the list of allocated blocks in i_snapblklist. 739 */ 740 if (I_IS_UFS1(ip)) 741 error = expunge_ufs1(vp, ip, copy_fs, mapacct_ufs1, 742 BLK_SNAP, 0); 743 else 744 error = expunge_ufs2(vp, ip, copy_fs, mapacct_ufs2, 745 BLK_SNAP, 0); 746 if (error) { 747 fs->fs_snapinum[snaploc] = 0; 748 free(snapblklist, M_UFSMNT); 749 goto done; 750 } 751 if (snaplistsize < ip->i_snapblklist - snapblklist) 752 panic("ffs_snapshot: list too small"); 753 snaplistsize = ip->i_snapblklist - snapblklist; 754 snapblklist[0] = snaplistsize; 755 ip->i_snapblklist = 0; 756 /* 757 * Write out the list of allocated blocks to the end of the snapshot. 758 */ 759 auio.uio_iov = &aiov; 760 auio.uio_iovcnt = 1; 761 aiov.iov_base = (void *)snapblklist; 762 aiov.iov_len = snaplistsize * sizeof(daddr_t); 763 auio.uio_resid = aiov.iov_len; 764 auio.uio_offset = ip->i_size; 765 auio.uio_segflg = UIO_SYSSPACE; 766 auio.uio_rw = UIO_WRITE; 767 auio.uio_td = td; 768 if ((error = VOP_WRITE(vp, &auio, IO_UNIT, td->td_ucred)) != 0) { 769 fs->fs_snapinum[snaploc] = 0; 770 free(snapblklist, M_UFSMNT); 771 goto done; 772 } 773 /* 774 * Write the superblock and its summary information 775 * to the snapshot. 776 */ 777 blkno = fragstoblks(fs, fs->fs_csaddr); 778 len = howmany(fs->fs_cssize, fs->fs_bsize); 779 space = copy_fs->fs_csp; 780 for (loc = 0; loc < len; loc++) { 781 error = bread(vp, blkno + loc, fs->fs_bsize, KERNCRED, &nbp); 782 if (error) { 783 brelse(nbp); 784 fs->fs_snapinum[snaploc] = 0; 785 free(snapblklist, M_UFSMNT); 786 goto done; 787 } 788 bcopy(space, nbp->b_data, fs->fs_bsize); 789 space = (char *)space + fs->fs_bsize; 790 bawrite(nbp); 791 } 792 error = bread(vp, lblkno(fs, fs->fs_sblockloc), fs->fs_bsize, 793 KERNCRED, &nbp); 794 if (error) { 795 brelse(nbp); 796 } else { 797 loc = blkoff(fs, fs->fs_sblockloc); 798 copy_fs->fs_ckhash = ffs_calc_sbhash(copy_fs); 799 bcopy((char *)copy_fs, &nbp->b_data[loc], (u_int)fs->fs_sbsize); 800 bawrite(nbp); 801 } 802 /* 803 * As this is the newest list, it is the most inclusive, so 804 * should replace the previous list. 805 */ 806 VI_LOCK(devvp); 807 space = sn->sn_blklist; 808 sn->sn_blklist = snapblklist; 809 sn->sn_listsize = snaplistsize; 810 VI_UNLOCK(devvp); 811 if (space != NULL) 812 free(space, M_UFSMNT); 813 /* 814 * Preallocate all the direct blocks in the snapshot inode so 815 * that we never have to write the inode itself to commit an 816 * update to the contents of the snapshot. Note that once 817 * created, the size of the snapshot will never change, so 818 * there will never be a need to write the inode except to 819 * update the non-integrity-critical time fields and 820 * allocated-block count. 821 */ 822 for (blockno = 0; blockno < UFS_NDADDR; blockno++) { 823 if (DIP(ip, i_db[blockno]) != 0) 824 continue; 825 error = UFS_BALLOC(vp, lblktosize(fs, blockno), 826 fs->fs_bsize, KERNCRED, BA_CLRBUF, &bp); 827 if (error) 828 break; 829 error = readblock(vp, bp, blockno); 830 bawrite(bp); 831 if (error != 0) 832 break; 833 } 834 done: 835 free(copy_fs->fs_csp, M_UFSMNT); 836 free(copy_fs, M_UFSMNT); 837 copy_fs = NULL; 838 out: 839 NDFREE(&nd, NDF_ONLY_PNBUF); 840 if (saved_nice > 0) { 841 struct proc *p; 842 843 p = td->td_proc; 844 PROC_LOCK(p); 845 sched_nice(td->td_proc, saved_nice); 846 PROC_UNLOCK(td->td_proc); 847 } 848 UFS_LOCK(ump); 849 if (fs->fs_active != 0) { 850 free(fs->fs_active, M_DEVBUF); 851 fs->fs_active = 0; 852 } 853 UFS_UNLOCK(ump); 854 MNT_ILOCK(mp); 855 mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | (flag & ~MNT_QUOTA); 856 MNT_IUNLOCK(mp); 857 if (error) 858 (void) ffs_truncate(vp, (off_t)0, 0, NOCRED); 859 (void) ffs_syncvnode(vp, MNT_WAIT, 0); 860 if (error) 861 vput(vp); 862 else 863 VOP_UNLOCK(vp, 0); 864 vrele(nd.ni_dvp); 865 vn_finished_write(wrtmp); 866 process_deferred_inactive(mp); 867 return (error); 868 } 869 870 /* 871 * Copy a cylinder group map. All the unallocated blocks are marked 872 * BLK_NOCOPY so that the snapshot knows that it need not copy them 873 * if they are later written. If passno is one, then this is a first 874 * pass, so only setting needs to be done. If passno is 2, then this 875 * is a revision to a previous pass which must be undone as the 876 * replacement pass is done. 877 */ 878 static int 879 cgaccount(cg, vp, nbp, passno) 880 int cg; 881 struct vnode *vp; 882 struct buf *nbp; 883 int passno; 884 { 885 struct buf *bp, *ibp; 886 struct inode *ip; 887 struct cg *cgp; 888 struct fs *fs; 889 ufs2_daddr_t base, numblks; 890 int error, len, loc, indiroff; 891 892 ip = VTOI(vp); 893 fs = ITOFS(ip); 894 if ((error = ffs_getcg(fs, ITODEVVP(ip), cg, &bp, &cgp)) != 0) 895 return (error); 896 UFS_LOCK(ITOUMP(ip)); 897 ACTIVESET(fs, cg); 898 /* 899 * Recomputation of summary information might not have been performed 900 * at mount time. Sync up summary information for current cylinder 901 * group while data is in memory to ensure that result of background 902 * fsck is slightly more consistent. 903 */ 904 fs->fs_cs(fs, cg) = cgp->cg_cs; 905 UFS_UNLOCK(ITOUMP(ip)); 906 bcopy(bp->b_data, nbp->b_data, fs->fs_cgsize); 907 if (fs->fs_cgsize < fs->fs_bsize) 908 bzero(&nbp->b_data[fs->fs_cgsize], 909 fs->fs_bsize - fs->fs_cgsize); 910 cgp = (struct cg *)nbp->b_data; 911 bqrelse(bp); 912 if (passno == 2) 913 nbp->b_flags |= B_VALIDSUSPWRT; 914 numblks = howmany(fs->fs_size, fs->fs_frag); 915 len = howmany(fs->fs_fpg, fs->fs_frag); 916 base = cgbase(fs, cg) / fs->fs_frag; 917 if (base + len >= numblks) 918 len = numblks - base - 1; 919 loc = 0; 920 if (base < UFS_NDADDR) { 921 for ( ; loc < UFS_NDADDR; loc++) { 922 if (ffs_isblock(fs, cg_blksfree(cgp), loc)) 923 DIP_SET(ip, i_db[loc], BLK_NOCOPY); 924 else if (passno == 2 && DIP(ip, i_db[loc])== BLK_NOCOPY) 925 DIP_SET(ip, i_db[loc], 0); 926 else if (passno == 1 && DIP(ip, i_db[loc])== BLK_NOCOPY) 927 panic("ffs_snapshot: lost direct block"); 928 } 929 } 930 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(base + loc)), 931 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 932 if (error) { 933 goto out; 934 } 935 indiroff = (base + loc - UFS_NDADDR) % NINDIR(fs); 936 for ( ; loc < len; loc++, indiroff++) { 937 if (indiroff >= NINDIR(fs)) { 938 if (passno == 2) 939 ibp->b_flags |= B_VALIDSUSPWRT; 940 bawrite(ibp); 941 error = UFS_BALLOC(vp, 942 lblktosize(fs, (off_t)(base + loc)), 943 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 944 if (error) { 945 goto out; 946 } 947 indiroff = 0; 948 } 949 if (I_IS_UFS1(ip)) { 950 if (ffs_isblock(fs, cg_blksfree(cgp), loc)) 951 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] = 952 BLK_NOCOPY; 953 else if (passno == 2 && ((ufs1_daddr_t *)(ibp->b_data)) 954 [indiroff] == BLK_NOCOPY) 955 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] = 0; 956 else if (passno == 1 && ((ufs1_daddr_t *)(ibp->b_data)) 957 [indiroff] == BLK_NOCOPY) 958 panic("ffs_snapshot: lost indirect block"); 959 continue; 960 } 961 if (ffs_isblock(fs, cg_blksfree(cgp), loc)) 962 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = BLK_NOCOPY; 963 else if (passno == 2 && 964 ((ufs2_daddr_t *)(ibp->b_data)) [indiroff] == BLK_NOCOPY) 965 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = 0; 966 else if (passno == 1 && 967 ((ufs2_daddr_t *)(ibp->b_data)) [indiroff] == BLK_NOCOPY) 968 panic("ffs_snapshot: lost indirect block"); 969 } 970 if (passno == 2) 971 ibp->b_flags |= B_VALIDSUSPWRT; 972 bdwrite(ibp); 973 out: 974 /* 975 * We have to calculate the crc32c here rather than just setting the 976 * BX_CYLGRP b_xflags because the allocation of the block for the 977 * the cylinder group map will always be a full size block (fs_bsize) 978 * even though the cylinder group may be smaller (fs_cgsize). The 979 * crc32c must be computed only over fs_cgsize whereas the BX_CYLGRP 980 * flag causes it to be computed over the size of the buffer. 981 */ 982 if ((fs->fs_metackhash & CK_CYLGRP) != 0) { 983 ((struct cg *)nbp->b_data)->cg_ckhash = 0; 984 ((struct cg *)nbp->b_data)->cg_ckhash = 985 calculate_crc32c(~0L, nbp->b_data, fs->fs_cgsize); 986 } 987 return (error); 988 } 989 990 /* 991 * Before expunging a snapshot inode, note all the 992 * blocks that it claims with BLK_SNAP so that fsck will 993 * be able to account for those blocks properly and so 994 * that this snapshot knows that it need not copy them 995 * if the other snapshot holding them is freed. This code 996 * is reproduced once each for UFS1 and UFS2. 997 */ 998 static int 999 expunge_ufs1(snapvp, cancelip, fs, acctfunc, expungetype, clearmode) 1000 struct vnode *snapvp; 1001 struct inode *cancelip; 1002 struct fs *fs; 1003 int (*acctfunc)(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, 1004 struct fs *, ufs_lbn_t, int); 1005 int expungetype; 1006 int clearmode; 1007 { 1008 int i, error, indiroff; 1009 ufs_lbn_t lbn, rlbn; 1010 ufs2_daddr_t len, blkno, numblks, blksperindir; 1011 struct ufs1_dinode *dip; 1012 struct thread *td = curthread; 1013 struct buf *bp; 1014 1015 /* 1016 * Prepare to expunge the inode. If its inode block has not 1017 * yet been copied, then allocate and fill the copy. 1018 */ 1019 lbn = fragstoblks(fs, ino_to_fsba(fs, cancelip->i_number)); 1020 blkno = 0; 1021 if (lbn < UFS_NDADDR) { 1022 blkno = VTOI(snapvp)->i_din1->di_db[lbn]; 1023 } else { 1024 if (DOINGSOFTDEP(snapvp)) 1025 softdep_prealloc(snapvp, MNT_WAIT); 1026 td->td_pflags |= TDP_COWINPROGRESS; 1027 error = ffs_balloc_ufs1(snapvp, lblktosize(fs, (off_t)lbn), 1028 fs->fs_bsize, KERNCRED, BA_METAONLY, &bp); 1029 td->td_pflags &= ~TDP_COWINPROGRESS; 1030 if (error) 1031 return (error); 1032 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs); 1033 blkno = ((ufs1_daddr_t *)(bp->b_data))[indiroff]; 1034 bqrelse(bp); 1035 } 1036 if (blkno != 0) { 1037 if ((error = bread(snapvp, lbn, fs->fs_bsize, KERNCRED, &bp))) 1038 return (error); 1039 } else { 1040 error = ffs_balloc_ufs1(snapvp, lblktosize(fs, (off_t)lbn), 1041 fs->fs_bsize, KERNCRED, 0, &bp); 1042 if (error) 1043 return (error); 1044 if ((error = readblock(snapvp, bp, lbn)) != 0) 1045 return (error); 1046 } 1047 /* 1048 * Set a snapshot inode to be a zero length file, regular files 1049 * or unlinked snapshots to be completely unallocated. 1050 */ 1051 dip = (struct ufs1_dinode *)bp->b_data + 1052 ino_to_fsbo(fs, cancelip->i_number); 1053 if (clearmode || cancelip->i_effnlink == 0) 1054 dip->di_mode = 0; 1055 dip->di_size = 0; 1056 dip->di_blocks = 0; 1057 dip->di_flags &= ~SF_SNAPSHOT; 1058 bzero(&dip->di_db[0], (UFS_NDADDR + UFS_NIADDR) * sizeof(ufs1_daddr_t)); 1059 bdwrite(bp); 1060 /* 1061 * Now go through and expunge all the blocks in the file 1062 * using the function requested. 1063 */ 1064 numblks = howmany(cancelip->i_size, fs->fs_bsize); 1065 if ((error = (*acctfunc)(snapvp, &cancelip->i_din1->di_db[0], 1066 &cancelip->i_din1->di_db[UFS_NDADDR], fs, 0, expungetype))) 1067 return (error); 1068 if ((error = (*acctfunc)(snapvp, &cancelip->i_din1->di_ib[0], 1069 &cancelip->i_din1->di_ib[UFS_NIADDR], fs, -1, expungetype))) 1070 return (error); 1071 blksperindir = 1; 1072 lbn = -UFS_NDADDR; 1073 len = numblks - UFS_NDADDR; 1074 rlbn = UFS_NDADDR; 1075 for (i = 0; len > 0 && i < UFS_NIADDR; i++) { 1076 error = indiracct_ufs1(snapvp, ITOV(cancelip), i, 1077 cancelip->i_din1->di_ib[i], lbn, rlbn, len, 1078 blksperindir, fs, acctfunc, expungetype); 1079 if (error) 1080 return (error); 1081 blksperindir *= NINDIR(fs); 1082 lbn -= blksperindir + 1; 1083 len -= blksperindir; 1084 rlbn += blksperindir; 1085 } 1086 return (0); 1087 } 1088 1089 /* 1090 * Descend an indirect block chain for vnode cancelvp accounting for all 1091 * its indirect blocks in snapvp. 1092 */ 1093 static int 1094 indiracct_ufs1(snapvp, cancelvp, level, blkno, lbn, rlbn, remblks, 1095 blksperindir, fs, acctfunc, expungetype) 1096 struct vnode *snapvp; 1097 struct vnode *cancelvp; 1098 int level; 1099 ufs1_daddr_t blkno; 1100 ufs_lbn_t lbn; 1101 ufs_lbn_t rlbn; 1102 ufs_lbn_t remblks; 1103 ufs_lbn_t blksperindir; 1104 struct fs *fs; 1105 int (*acctfunc)(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, 1106 struct fs *, ufs_lbn_t, int); 1107 int expungetype; 1108 { 1109 int error, num, i; 1110 ufs_lbn_t subblksperindir; 1111 struct indir indirs[UFS_NIADDR + 2]; 1112 ufs1_daddr_t last, *bap; 1113 struct buf *bp; 1114 1115 if (blkno == 0) { 1116 if (expungetype == BLK_NOCOPY) 1117 return (0); 1118 panic("indiracct_ufs1: missing indir"); 1119 } 1120 if ((error = ufs_getlbns(cancelvp, rlbn, indirs, &num)) != 0) 1121 return (error); 1122 if (lbn != indirs[num - 1 - level].in_lbn || num < 2) 1123 panic("indiracct_ufs1: botched params"); 1124 /* 1125 * We have to expand bread here since it will deadlock looking 1126 * up the block number for any blocks that are not in the cache. 1127 */ 1128 bp = getblk(cancelvp, lbn, fs->fs_bsize, 0, 0, 0); 1129 bp->b_blkno = fsbtodb(fs, blkno); 1130 if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0 && 1131 (error = readblock(cancelvp, bp, fragstoblks(fs, blkno)))) { 1132 brelse(bp); 1133 return (error); 1134 } 1135 /* 1136 * Account for the block pointers in this indirect block. 1137 */ 1138 last = howmany(remblks, blksperindir); 1139 if (last > NINDIR(fs)) 1140 last = NINDIR(fs); 1141 bap = malloc(fs->fs_bsize, M_DEVBUF, M_WAITOK); 1142 bcopy(bp->b_data, (caddr_t)bap, fs->fs_bsize); 1143 bqrelse(bp); 1144 error = (*acctfunc)(snapvp, &bap[0], &bap[last], fs, 1145 level == 0 ? rlbn : -1, expungetype); 1146 if (error || level == 0) 1147 goto out; 1148 /* 1149 * Account for the block pointers in each of the indirect blocks 1150 * in the levels below us. 1151 */ 1152 subblksperindir = blksperindir / NINDIR(fs); 1153 for (lbn++, level--, i = 0; i < last; i++) { 1154 error = indiracct_ufs1(snapvp, cancelvp, level, bap[i], lbn, 1155 rlbn, remblks, subblksperindir, fs, acctfunc, expungetype); 1156 if (error) 1157 goto out; 1158 rlbn += blksperindir; 1159 lbn -= blksperindir; 1160 remblks -= blksperindir; 1161 } 1162 out: 1163 free(bap, M_DEVBUF); 1164 return (error); 1165 } 1166 1167 /* 1168 * Do both snap accounting and map accounting. 1169 */ 1170 static int 1171 fullacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, exptype) 1172 struct vnode *vp; 1173 ufs1_daddr_t *oldblkp, *lastblkp; 1174 struct fs *fs; 1175 ufs_lbn_t lblkno; 1176 int exptype; /* BLK_SNAP or BLK_NOCOPY */ 1177 { 1178 int error; 1179 1180 if ((error = snapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, exptype))) 1181 return (error); 1182 return (mapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, exptype)); 1183 } 1184 1185 /* 1186 * Identify a set of blocks allocated in a snapshot inode. 1187 */ 1188 static int 1189 snapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, expungetype) 1190 struct vnode *vp; 1191 ufs1_daddr_t *oldblkp, *lastblkp; 1192 struct fs *fs; 1193 ufs_lbn_t lblkno; 1194 int expungetype; /* BLK_SNAP or BLK_NOCOPY */ 1195 { 1196 struct inode *ip = VTOI(vp); 1197 ufs1_daddr_t blkno, *blkp; 1198 ufs_lbn_t lbn; 1199 struct buf *ibp; 1200 int error; 1201 1202 for ( ; oldblkp < lastblkp; oldblkp++) { 1203 blkno = *oldblkp; 1204 if (blkno == 0 || blkno == BLK_NOCOPY || blkno == BLK_SNAP) 1205 continue; 1206 lbn = fragstoblks(fs, blkno); 1207 if (lbn < UFS_NDADDR) { 1208 blkp = &ip->i_din1->di_db[lbn]; 1209 ip->i_flag |= IN_CHANGE | IN_UPDATE; 1210 } else { 1211 error = ffs_balloc_ufs1(vp, lblktosize(fs, (off_t)lbn), 1212 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 1213 if (error) 1214 return (error); 1215 blkp = &((ufs1_daddr_t *)(ibp->b_data)) 1216 [(lbn - UFS_NDADDR) % NINDIR(fs)]; 1217 } 1218 /* 1219 * If we are expunging a snapshot vnode and we 1220 * find a block marked BLK_NOCOPY, then it is 1221 * one that has been allocated to this snapshot after 1222 * we took our current snapshot and can be ignored. 1223 */ 1224 if (expungetype == BLK_SNAP && *blkp == BLK_NOCOPY) { 1225 if (lbn >= UFS_NDADDR) 1226 brelse(ibp); 1227 } else { 1228 if (*blkp != 0) 1229 panic("snapacct_ufs1: bad block"); 1230 *blkp = expungetype; 1231 if (lbn >= UFS_NDADDR) 1232 bdwrite(ibp); 1233 } 1234 } 1235 return (0); 1236 } 1237 1238 /* 1239 * Account for a set of blocks allocated in a snapshot inode. 1240 */ 1241 static int 1242 mapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, expungetype) 1243 struct vnode *vp; 1244 ufs1_daddr_t *oldblkp, *lastblkp; 1245 struct fs *fs; 1246 ufs_lbn_t lblkno; 1247 int expungetype; 1248 { 1249 ufs1_daddr_t blkno; 1250 struct inode *ip; 1251 ino_t inum; 1252 int acctit; 1253 1254 ip = VTOI(vp); 1255 inum = ip->i_number; 1256 if (lblkno == -1) 1257 acctit = 0; 1258 else 1259 acctit = 1; 1260 for ( ; oldblkp < lastblkp; oldblkp++, lblkno++) { 1261 blkno = *oldblkp; 1262 if (blkno == 0 || blkno == BLK_NOCOPY) 1263 continue; 1264 if (acctit && expungetype == BLK_SNAP && blkno != BLK_SNAP) 1265 *ip->i_snapblklist++ = lblkno; 1266 if (blkno == BLK_SNAP) 1267 blkno = blkstofrags(fs, lblkno); 1268 ffs_blkfree(ITOUMP(ip), fs, vp, blkno, fs->fs_bsize, inum, 1269 vp->v_type, NULL, SINGLETON_KEY); 1270 } 1271 return (0); 1272 } 1273 1274 /* 1275 * Before expunging a snapshot inode, note all the 1276 * blocks that it claims with BLK_SNAP so that fsck will 1277 * be able to account for those blocks properly and so 1278 * that this snapshot knows that it need not copy them 1279 * if the other snapshot holding them is freed. This code 1280 * is reproduced once each for UFS1 and UFS2. 1281 */ 1282 static int 1283 expunge_ufs2(snapvp, cancelip, fs, acctfunc, expungetype, clearmode) 1284 struct vnode *snapvp; 1285 struct inode *cancelip; 1286 struct fs *fs; 1287 int (*acctfunc)(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, 1288 struct fs *, ufs_lbn_t, int); 1289 int expungetype; 1290 int clearmode; 1291 { 1292 int i, error, indiroff; 1293 ufs_lbn_t lbn, rlbn; 1294 ufs2_daddr_t len, blkno, numblks, blksperindir; 1295 struct ufs2_dinode *dip; 1296 struct thread *td = curthread; 1297 struct buf *bp; 1298 1299 /* 1300 * Prepare to expunge the inode. If its inode block has not 1301 * yet been copied, then allocate and fill the copy. 1302 */ 1303 lbn = fragstoblks(fs, ino_to_fsba(fs, cancelip->i_number)); 1304 blkno = 0; 1305 if (lbn < UFS_NDADDR) { 1306 blkno = VTOI(snapvp)->i_din2->di_db[lbn]; 1307 } else { 1308 if (DOINGSOFTDEP(snapvp)) 1309 softdep_prealloc(snapvp, MNT_WAIT); 1310 td->td_pflags |= TDP_COWINPROGRESS; 1311 error = ffs_balloc_ufs2(snapvp, lblktosize(fs, (off_t)lbn), 1312 fs->fs_bsize, KERNCRED, BA_METAONLY, &bp); 1313 td->td_pflags &= ~TDP_COWINPROGRESS; 1314 if (error) 1315 return (error); 1316 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs); 1317 blkno = ((ufs2_daddr_t *)(bp->b_data))[indiroff]; 1318 bqrelse(bp); 1319 } 1320 if (blkno != 0) { 1321 if ((error = bread(snapvp, lbn, fs->fs_bsize, KERNCRED, &bp))) 1322 return (error); 1323 } else { 1324 error = ffs_balloc_ufs2(snapvp, lblktosize(fs, (off_t)lbn), 1325 fs->fs_bsize, KERNCRED, 0, &bp); 1326 if (error) 1327 return (error); 1328 if ((error = readblock(snapvp, bp, lbn)) != 0) 1329 return (error); 1330 } 1331 /* 1332 * Set a snapshot inode to be a zero length file, regular files 1333 * to be completely unallocated. 1334 */ 1335 dip = (struct ufs2_dinode *)bp->b_data + 1336 ino_to_fsbo(fs, cancelip->i_number); 1337 dip->di_size = 0; 1338 dip->di_blocks = 0; 1339 dip->di_flags &= ~SF_SNAPSHOT; 1340 bzero(&dip->di_db[0], (UFS_NDADDR + UFS_NIADDR) * sizeof(ufs2_daddr_t)); 1341 if (clearmode || cancelip->i_effnlink == 0) 1342 dip->di_mode = 0; 1343 else 1344 ffs_update_dinode_ckhash(fs, dip); 1345 bdwrite(bp); 1346 /* 1347 * Now go through and expunge all the blocks in the file 1348 * using the function requested. 1349 */ 1350 numblks = howmany(cancelip->i_size, fs->fs_bsize); 1351 if ((error = (*acctfunc)(snapvp, &cancelip->i_din2->di_db[0], 1352 &cancelip->i_din2->di_db[UFS_NDADDR], fs, 0, expungetype))) 1353 return (error); 1354 if ((error = (*acctfunc)(snapvp, &cancelip->i_din2->di_ib[0], 1355 &cancelip->i_din2->di_ib[UFS_NIADDR], fs, -1, expungetype))) 1356 return (error); 1357 blksperindir = 1; 1358 lbn = -UFS_NDADDR; 1359 len = numblks - UFS_NDADDR; 1360 rlbn = UFS_NDADDR; 1361 for (i = 0; len > 0 && i < UFS_NIADDR; i++) { 1362 error = indiracct_ufs2(snapvp, ITOV(cancelip), i, 1363 cancelip->i_din2->di_ib[i], lbn, rlbn, len, 1364 blksperindir, fs, acctfunc, expungetype); 1365 if (error) 1366 return (error); 1367 blksperindir *= NINDIR(fs); 1368 lbn -= blksperindir + 1; 1369 len -= blksperindir; 1370 rlbn += blksperindir; 1371 } 1372 return (0); 1373 } 1374 1375 /* 1376 * Descend an indirect block chain for vnode cancelvp accounting for all 1377 * its indirect blocks in snapvp. 1378 */ 1379 static int 1380 indiracct_ufs2(snapvp, cancelvp, level, blkno, lbn, rlbn, remblks, 1381 blksperindir, fs, acctfunc, expungetype) 1382 struct vnode *snapvp; 1383 struct vnode *cancelvp; 1384 int level; 1385 ufs2_daddr_t blkno; 1386 ufs_lbn_t lbn; 1387 ufs_lbn_t rlbn; 1388 ufs_lbn_t remblks; 1389 ufs_lbn_t blksperindir; 1390 struct fs *fs; 1391 int (*acctfunc)(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, 1392 struct fs *, ufs_lbn_t, int); 1393 int expungetype; 1394 { 1395 int error, num, i; 1396 ufs_lbn_t subblksperindir; 1397 struct indir indirs[UFS_NIADDR + 2]; 1398 ufs2_daddr_t last, *bap; 1399 struct buf *bp; 1400 1401 if (blkno == 0) { 1402 if (expungetype == BLK_NOCOPY) 1403 return (0); 1404 panic("indiracct_ufs2: missing indir"); 1405 } 1406 if ((error = ufs_getlbns(cancelvp, rlbn, indirs, &num)) != 0) 1407 return (error); 1408 if (lbn != indirs[num - 1 - level].in_lbn || num < 2) 1409 panic("indiracct_ufs2: botched params"); 1410 /* 1411 * We have to expand bread here since it will deadlock looking 1412 * up the block number for any blocks that are not in the cache. 1413 */ 1414 bp = getblk(cancelvp, lbn, fs->fs_bsize, 0, 0, 0); 1415 bp->b_blkno = fsbtodb(fs, blkno); 1416 if ((bp->b_flags & B_CACHE) == 0 && 1417 (error = readblock(cancelvp, bp, fragstoblks(fs, blkno)))) { 1418 brelse(bp); 1419 return (error); 1420 } 1421 /* 1422 * Account for the block pointers in this indirect block. 1423 */ 1424 last = howmany(remblks, blksperindir); 1425 if (last > NINDIR(fs)) 1426 last = NINDIR(fs); 1427 bap = malloc(fs->fs_bsize, M_DEVBUF, M_WAITOK); 1428 bcopy(bp->b_data, (caddr_t)bap, fs->fs_bsize); 1429 bqrelse(bp); 1430 error = (*acctfunc)(snapvp, &bap[0], &bap[last], fs, 1431 level == 0 ? rlbn : -1, expungetype); 1432 if (error || level == 0) 1433 goto out; 1434 /* 1435 * Account for the block pointers in each of the indirect blocks 1436 * in the levels below us. 1437 */ 1438 subblksperindir = blksperindir / NINDIR(fs); 1439 for (lbn++, level--, i = 0; i < last; i++) { 1440 error = indiracct_ufs2(snapvp, cancelvp, level, bap[i], lbn, 1441 rlbn, remblks, subblksperindir, fs, acctfunc, expungetype); 1442 if (error) 1443 goto out; 1444 rlbn += blksperindir; 1445 lbn -= blksperindir; 1446 remblks -= blksperindir; 1447 } 1448 out: 1449 free(bap, M_DEVBUF); 1450 return (error); 1451 } 1452 1453 /* 1454 * Do both snap accounting and map accounting. 1455 */ 1456 static int 1457 fullacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, exptype) 1458 struct vnode *vp; 1459 ufs2_daddr_t *oldblkp, *lastblkp; 1460 struct fs *fs; 1461 ufs_lbn_t lblkno; 1462 int exptype; /* BLK_SNAP or BLK_NOCOPY */ 1463 { 1464 int error; 1465 1466 if ((error = snapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, exptype))) 1467 return (error); 1468 return (mapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, exptype)); 1469 } 1470 1471 /* 1472 * Identify a set of blocks allocated in a snapshot inode. 1473 */ 1474 static int 1475 snapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, expungetype) 1476 struct vnode *vp; 1477 ufs2_daddr_t *oldblkp, *lastblkp; 1478 struct fs *fs; 1479 ufs_lbn_t lblkno; 1480 int expungetype; /* BLK_SNAP or BLK_NOCOPY */ 1481 { 1482 struct inode *ip = VTOI(vp); 1483 ufs2_daddr_t blkno, *blkp; 1484 ufs_lbn_t lbn; 1485 struct buf *ibp; 1486 int error; 1487 1488 for ( ; oldblkp < lastblkp; oldblkp++) { 1489 blkno = *oldblkp; 1490 if (blkno == 0 || blkno == BLK_NOCOPY || blkno == BLK_SNAP) 1491 continue; 1492 lbn = fragstoblks(fs, blkno); 1493 if (lbn < UFS_NDADDR) { 1494 blkp = &ip->i_din2->di_db[lbn]; 1495 ip->i_flag |= IN_CHANGE | IN_UPDATE; 1496 } else { 1497 error = ffs_balloc_ufs2(vp, lblktosize(fs, (off_t)lbn), 1498 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 1499 if (error) 1500 return (error); 1501 blkp = &((ufs2_daddr_t *)(ibp->b_data)) 1502 [(lbn - UFS_NDADDR) % NINDIR(fs)]; 1503 } 1504 /* 1505 * If we are expunging a snapshot vnode and we 1506 * find a block marked BLK_NOCOPY, then it is 1507 * one that has been allocated to this snapshot after 1508 * we took our current snapshot and can be ignored. 1509 */ 1510 if (expungetype == BLK_SNAP && *blkp == BLK_NOCOPY) { 1511 if (lbn >= UFS_NDADDR) 1512 brelse(ibp); 1513 } else { 1514 if (*blkp != 0) 1515 panic("snapacct_ufs2: bad block"); 1516 *blkp = expungetype; 1517 if (lbn >= UFS_NDADDR) 1518 bdwrite(ibp); 1519 } 1520 } 1521 return (0); 1522 } 1523 1524 /* 1525 * Account for a set of blocks allocated in a snapshot inode. 1526 */ 1527 static int 1528 mapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, expungetype) 1529 struct vnode *vp; 1530 ufs2_daddr_t *oldblkp, *lastblkp; 1531 struct fs *fs; 1532 ufs_lbn_t lblkno; 1533 int expungetype; 1534 { 1535 ufs2_daddr_t blkno; 1536 struct inode *ip; 1537 ino_t inum; 1538 int acctit; 1539 1540 ip = VTOI(vp); 1541 inum = ip->i_number; 1542 if (lblkno == -1) 1543 acctit = 0; 1544 else 1545 acctit = 1; 1546 for ( ; oldblkp < lastblkp; oldblkp++, lblkno++) { 1547 blkno = *oldblkp; 1548 if (blkno == 0 || blkno == BLK_NOCOPY) 1549 continue; 1550 if (acctit && expungetype == BLK_SNAP && blkno != BLK_SNAP) 1551 *ip->i_snapblklist++ = lblkno; 1552 if (blkno == BLK_SNAP) 1553 blkno = blkstofrags(fs, lblkno); 1554 ffs_blkfree(ITOUMP(ip), fs, vp, blkno, fs->fs_bsize, inum, 1555 vp->v_type, NULL, SINGLETON_KEY); 1556 } 1557 return (0); 1558 } 1559 1560 /* 1561 * Decrement extra reference on snapshot when last name is removed. 1562 * It will not be freed until the last open reference goes away. 1563 */ 1564 void 1565 ffs_snapgone(ip) 1566 struct inode *ip; 1567 { 1568 struct inode *xp; 1569 struct fs *fs; 1570 int snaploc; 1571 struct snapdata *sn; 1572 struct ufsmount *ump; 1573 1574 /* 1575 * Find snapshot in incore list. 1576 */ 1577 xp = NULL; 1578 sn = ITODEVVP(ip)->v_rdev->si_snapdata; 1579 if (sn != NULL) 1580 TAILQ_FOREACH(xp, &sn->sn_head, i_nextsnap) 1581 if (xp == ip) 1582 break; 1583 if (xp != NULL) 1584 vrele(ITOV(ip)); 1585 else if (snapdebug) 1586 printf("ffs_snapgone: lost snapshot vnode %ju\n", 1587 (uintmax_t)ip->i_number); 1588 /* 1589 * Delete snapshot inode from superblock. Keep list dense. 1590 */ 1591 ump = ITOUMP(ip); 1592 fs = ump->um_fs; 1593 UFS_LOCK(ump); 1594 for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++) 1595 if (fs->fs_snapinum[snaploc] == ip->i_number) 1596 break; 1597 if (snaploc < FSMAXSNAP) { 1598 for (snaploc++; snaploc < FSMAXSNAP; snaploc++) { 1599 if (fs->fs_snapinum[snaploc] == 0) 1600 break; 1601 fs->fs_snapinum[snaploc - 1] = fs->fs_snapinum[snaploc]; 1602 } 1603 fs->fs_snapinum[snaploc - 1] = 0; 1604 } 1605 UFS_UNLOCK(ump); 1606 } 1607 1608 /* 1609 * Prepare a snapshot file for being removed. 1610 */ 1611 void 1612 ffs_snapremove(vp) 1613 struct vnode *vp; 1614 { 1615 struct inode *ip; 1616 struct vnode *devvp; 1617 struct buf *ibp; 1618 struct fs *fs; 1619 ufs2_daddr_t numblks, blkno, dblk; 1620 int error, i, last, loc; 1621 struct snapdata *sn; 1622 1623 ip = VTOI(vp); 1624 fs = ITOFS(ip); 1625 devvp = ITODEVVP(ip); 1626 /* 1627 * If active, delete from incore list (this snapshot may 1628 * already have been in the process of being deleted, so 1629 * would not have been active). 1630 * 1631 * Clear copy-on-write flag if last snapshot. 1632 */ 1633 VI_LOCK(devvp); 1634 if (ip->i_nextsnap.tqe_prev != 0) { 1635 sn = devvp->v_rdev->si_snapdata; 1636 TAILQ_REMOVE(&sn->sn_head, ip, i_nextsnap); 1637 ip->i_nextsnap.tqe_prev = 0; 1638 VI_UNLOCK(devvp); 1639 lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL); 1640 for (i = 0; i < sn->sn_lock.lk_recurse; i++) 1641 lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL); 1642 KASSERT(vp->v_vnlock == &sn->sn_lock, 1643 ("ffs_snapremove: lost lock mutation")); 1644 vp->v_vnlock = &vp->v_lock; 1645 VI_LOCK(devvp); 1646 while (sn->sn_lock.lk_recurse > 0) 1647 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 1648 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 1649 try_free_snapdata(devvp); 1650 } else 1651 VI_UNLOCK(devvp); 1652 /* 1653 * Clear all BLK_NOCOPY fields. Pass any block claims to other 1654 * snapshots that want them (see ffs_snapblkfree below). 1655 */ 1656 for (blkno = 1; blkno < UFS_NDADDR; blkno++) { 1657 dblk = DIP(ip, i_db[blkno]); 1658 if (dblk == 0) 1659 continue; 1660 if (dblk == BLK_NOCOPY || dblk == BLK_SNAP) 1661 DIP_SET(ip, i_db[blkno], 0); 1662 else if ((dblk == blkstofrags(fs, blkno) && 1663 ffs_snapblkfree(fs, ITODEVVP(ip), dblk, fs->fs_bsize, 1664 ip->i_number, vp->v_type, NULL))) { 1665 DIP_SET(ip, i_blocks, DIP(ip, i_blocks) - 1666 btodb(fs->fs_bsize)); 1667 DIP_SET(ip, i_db[blkno], 0); 1668 } 1669 } 1670 numblks = howmany(ip->i_size, fs->fs_bsize); 1671 for (blkno = UFS_NDADDR; blkno < numblks; blkno += NINDIR(fs)) { 1672 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)blkno), 1673 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 1674 if (error) 1675 continue; 1676 if (fs->fs_size - blkno > NINDIR(fs)) 1677 last = NINDIR(fs); 1678 else 1679 last = fs->fs_size - blkno; 1680 for (loc = 0; loc < last; loc++) { 1681 if (I_IS_UFS1(ip)) { 1682 dblk = ((ufs1_daddr_t *)(ibp->b_data))[loc]; 1683 if (dblk == 0) 1684 continue; 1685 if (dblk == BLK_NOCOPY || dblk == BLK_SNAP) 1686 ((ufs1_daddr_t *)(ibp->b_data))[loc]= 0; 1687 else if ((dblk == blkstofrags(fs, blkno) && 1688 ffs_snapblkfree(fs, ITODEVVP(ip), dblk, 1689 fs->fs_bsize, ip->i_number, vp->v_type, 1690 NULL))) { 1691 ip->i_din1->di_blocks -= 1692 btodb(fs->fs_bsize); 1693 ((ufs1_daddr_t *)(ibp->b_data))[loc]= 0; 1694 } 1695 continue; 1696 } 1697 dblk = ((ufs2_daddr_t *)(ibp->b_data))[loc]; 1698 if (dblk == 0) 1699 continue; 1700 if (dblk == BLK_NOCOPY || dblk == BLK_SNAP) 1701 ((ufs2_daddr_t *)(ibp->b_data))[loc] = 0; 1702 else if ((dblk == blkstofrags(fs, blkno) && 1703 ffs_snapblkfree(fs, ITODEVVP(ip), dblk, 1704 fs->fs_bsize, ip->i_number, vp->v_type, NULL))) { 1705 ip->i_din2->di_blocks -= btodb(fs->fs_bsize); 1706 ((ufs2_daddr_t *)(ibp->b_data))[loc] = 0; 1707 } 1708 } 1709 bawrite(ibp); 1710 } 1711 /* 1712 * Clear snapshot flag and drop reference. 1713 */ 1714 ip->i_flags &= ~SF_SNAPSHOT; 1715 DIP_SET(ip, i_flags, ip->i_flags); 1716 ip->i_flag |= IN_CHANGE | IN_UPDATE; 1717 /* 1718 * The dirtied indirects must be written out before 1719 * softdep_setup_freeblocks() is called. Otherwise indir_trunc() 1720 * may find indirect pointers using the magic BLK_* values. 1721 */ 1722 if (DOINGSOFTDEP(vp)) 1723 ffs_syncvnode(vp, MNT_WAIT, 0); 1724 #ifdef QUOTA 1725 /* 1726 * Reenable disk quotas for ex-snapshot file. 1727 */ 1728 if (!getinoquota(ip)) 1729 (void) chkdq(ip, DIP(ip, i_blocks), KERNCRED, FORCE); 1730 #endif 1731 } 1732 1733 /* 1734 * Notification that a block is being freed. Return zero if the free 1735 * should be allowed to proceed. Return non-zero if the snapshot file 1736 * wants to claim the block. The block will be claimed if it is an 1737 * uncopied part of one of the snapshots. It will be freed if it is 1738 * either a BLK_NOCOPY or has already been copied in all of the snapshots. 1739 * If a fragment is being freed, then all snapshots that care about 1740 * it must make a copy since a snapshot file can only claim full sized 1741 * blocks. Note that if more than one snapshot file maps the block, 1742 * we can pick one at random to claim it. Since none of the snapshots 1743 * can change, we are assurred that they will all see the same unmodified 1744 * image. When deleting a snapshot file (see ffs_snapremove above), we 1745 * must push any of these claimed blocks to one of the other snapshots 1746 * that maps it. These claimed blocks are easily identified as they will 1747 * have a block number equal to their logical block number within the 1748 * snapshot. A copied block can never have this property because they 1749 * must always have been allocated from a BLK_NOCOPY location. 1750 */ 1751 int 1752 ffs_snapblkfree(fs, devvp, bno, size, inum, vtype, wkhd) 1753 struct fs *fs; 1754 struct vnode *devvp; 1755 ufs2_daddr_t bno; 1756 long size; 1757 ino_t inum; 1758 enum vtype vtype; 1759 struct workhead *wkhd; 1760 { 1761 struct buf *ibp, *cbp, *savedcbp = NULL; 1762 struct thread *td = curthread; 1763 struct inode *ip; 1764 struct vnode *vp = NULL; 1765 ufs_lbn_t lbn; 1766 ufs2_daddr_t blkno; 1767 int indiroff = 0, error = 0, claimedblk = 0; 1768 struct snapdata *sn; 1769 1770 lbn = fragstoblks(fs, bno); 1771 retry: 1772 VI_LOCK(devvp); 1773 sn = devvp->v_rdev->si_snapdata; 1774 if (sn == NULL) { 1775 VI_UNLOCK(devvp); 1776 return (0); 1777 } 1778 if (lockmgr(&sn->sn_lock, LK_INTERLOCK | LK_EXCLUSIVE | LK_SLEEPFAIL, 1779 VI_MTX(devvp)) != 0) 1780 goto retry; 1781 TAILQ_FOREACH(ip, &sn->sn_head, i_nextsnap) { 1782 vp = ITOV(ip); 1783 if (DOINGSOFTDEP(vp)) 1784 softdep_prealloc(vp, MNT_WAIT); 1785 /* 1786 * Lookup block being written. 1787 */ 1788 if (lbn < UFS_NDADDR) { 1789 blkno = DIP(ip, i_db[lbn]); 1790 } else { 1791 td->td_pflags |= TDP_COWINPROGRESS; 1792 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn), 1793 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 1794 td->td_pflags &= ~TDP_COWINPROGRESS; 1795 if (error) 1796 break; 1797 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs); 1798 if (I_IS_UFS1(ip)) 1799 blkno=((ufs1_daddr_t *)(ibp->b_data))[indiroff]; 1800 else 1801 blkno=((ufs2_daddr_t *)(ibp->b_data))[indiroff]; 1802 } 1803 /* 1804 * Check to see if block needs to be copied. 1805 */ 1806 if (blkno == 0) { 1807 /* 1808 * A block that we map is being freed. If it has not 1809 * been claimed yet, we will claim or copy it (below). 1810 */ 1811 claimedblk = 1; 1812 } else if (blkno == BLK_SNAP) { 1813 /* 1814 * No previous snapshot claimed the block, 1815 * so it will be freed and become a BLK_NOCOPY 1816 * (don't care) for us. 1817 */ 1818 if (claimedblk) 1819 panic("snapblkfree: inconsistent block type"); 1820 if (lbn < UFS_NDADDR) { 1821 DIP_SET(ip, i_db[lbn], BLK_NOCOPY); 1822 ip->i_flag |= IN_CHANGE | IN_UPDATE; 1823 } else if (I_IS_UFS1(ip)) { 1824 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] = 1825 BLK_NOCOPY; 1826 bdwrite(ibp); 1827 } else { 1828 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = 1829 BLK_NOCOPY; 1830 bdwrite(ibp); 1831 } 1832 continue; 1833 } else /* BLK_NOCOPY or default */ { 1834 /* 1835 * If the snapshot has already copied the block 1836 * (default), or does not care about the block, 1837 * it is not needed. 1838 */ 1839 if (lbn >= UFS_NDADDR) 1840 bqrelse(ibp); 1841 continue; 1842 } 1843 /* 1844 * If this is a full size block, we will just grab it 1845 * and assign it to the snapshot inode. Otherwise we 1846 * will proceed to copy it. See explanation for this 1847 * routine as to why only a single snapshot needs to 1848 * claim this block. 1849 */ 1850 if (size == fs->fs_bsize) { 1851 #ifdef DEBUG 1852 if (snapdebug) 1853 printf("%s %ju lbn %jd from inum %ju\n", 1854 "Grabonremove: snapino", 1855 (uintmax_t)ip->i_number, 1856 (intmax_t)lbn, (uintmax_t)inum); 1857 #endif 1858 /* 1859 * If journaling is tracking this write we must add 1860 * the work to the inode or indirect being written. 1861 */ 1862 if (wkhd != NULL) { 1863 if (lbn < UFS_NDADDR) 1864 softdep_inode_append(ip, 1865 curthread->td_ucred, wkhd); 1866 else 1867 softdep_buf_append(ibp, wkhd); 1868 } 1869 if (lbn < UFS_NDADDR) { 1870 DIP_SET(ip, i_db[lbn], bno); 1871 } else if (I_IS_UFS1(ip)) { 1872 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] = bno; 1873 bdwrite(ibp); 1874 } else { 1875 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = bno; 1876 bdwrite(ibp); 1877 } 1878 DIP_SET(ip, i_blocks, DIP(ip, i_blocks) + btodb(size)); 1879 ip->i_flag |= IN_CHANGE | IN_UPDATE; 1880 lockmgr(vp->v_vnlock, LK_RELEASE, NULL); 1881 return (1); 1882 } 1883 if (lbn >= UFS_NDADDR) 1884 bqrelse(ibp); 1885 /* 1886 * Allocate the block into which to do the copy. Note that this 1887 * allocation will never require any additional allocations for 1888 * the snapshot inode. 1889 */ 1890 td->td_pflags |= TDP_COWINPROGRESS; 1891 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn), 1892 fs->fs_bsize, KERNCRED, 0, &cbp); 1893 td->td_pflags &= ~TDP_COWINPROGRESS; 1894 if (error) 1895 break; 1896 #ifdef DEBUG 1897 if (snapdebug) 1898 printf("%s%ju lbn %jd %s %ju size %ld to blkno %jd\n", 1899 "Copyonremove: snapino ", (uintmax_t)ip->i_number, 1900 (intmax_t)lbn, "for inum", (uintmax_t)inum, size, 1901 (intmax_t)cbp->b_blkno); 1902 #endif 1903 /* 1904 * If we have already read the old block contents, then 1905 * simply copy them to the new block. Note that we need 1906 * to synchronously write snapshots that have not been 1907 * unlinked, and hence will be visible after a crash, 1908 * to ensure their integrity. At a minimum we ensure the 1909 * integrity of the filesystem metadata, but use the 1910 * dopersistence sysctl-setable flag to decide on the 1911 * persistence needed for file content data. 1912 */ 1913 if (savedcbp != NULL) { 1914 bcopy(savedcbp->b_data, cbp->b_data, fs->fs_bsize); 1915 bawrite(cbp); 1916 if ((vtype == VDIR || dopersistence) && 1917 ip->i_effnlink > 0) 1918 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 1919 continue; 1920 } 1921 /* 1922 * Otherwise, read the old block contents into the buffer. 1923 */ 1924 if ((error = readblock(vp, cbp, lbn)) != 0) { 1925 bzero(cbp->b_data, fs->fs_bsize); 1926 bawrite(cbp); 1927 if ((vtype == VDIR || dopersistence) && 1928 ip->i_effnlink > 0) 1929 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 1930 break; 1931 } 1932 savedcbp = cbp; 1933 } 1934 /* 1935 * Note that we need to synchronously write snapshots that 1936 * have not been unlinked, and hence will be visible after 1937 * a crash, to ensure their integrity. At a minimum we 1938 * ensure the integrity of the filesystem metadata, but 1939 * use the dopersistence sysctl-setable flag to decide on 1940 * the persistence needed for file content data. 1941 */ 1942 if (savedcbp) { 1943 vp = savedcbp->b_vp; 1944 bawrite(savedcbp); 1945 if ((vtype == VDIR || dopersistence) && 1946 VTOI(vp)->i_effnlink > 0) 1947 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 1948 } 1949 /* 1950 * If we have been unable to allocate a block in which to do 1951 * the copy, then return non-zero so that the fragment will 1952 * not be freed. Although space will be lost, the snapshot 1953 * will stay consistent. 1954 */ 1955 if (error != 0 && wkhd != NULL) 1956 softdep_freework(wkhd); 1957 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 1958 return (error); 1959 } 1960 1961 /* 1962 * Associate snapshot files when mounting. 1963 */ 1964 void 1965 ffs_snapshot_mount(mp) 1966 struct mount *mp; 1967 { 1968 struct ufsmount *ump = VFSTOUFS(mp); 1969 struct vnode *devvp = ump->um_devvp; 1970 struct fs *fs = ump->um_fs; 1971 struct thread *td = curthread; 1972 struct snapdata *sn; 1973 struct vnode *vp; 1974 struct vnode *lastvp; 1975 struct inode *ip; 1976 struct uio auio; 1977 struct iovec aiov; 1978 void *snapblklist; 1979 char *reason; 1980 daddr_t snaplistsize; 1981 int error, snaploc, loc; 1982 1983 /* 1984 * XXX The following needs to be set before ffs_truncate or 1985 * VOP_READ can be called. 1986 */ 1987 mp->mnt_stat.f_iosize = fs->fs_bsize; 1988 /* 1989 * Process each snapshot listed in the superblock. 1990 */ 1991 vp = NULL; 1992 lastvp = NULL; 1993 sn = NULL; 1994 for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++) { 1995 if (fs->fs_snapinum[snaploc] == 0) 1996 break; 1997 if ((error = ffs_vget(mp, fs->fs_snapinum[snaploc], 1998 LK_EXCLUSIVE, &vp)) != 0){ 1999 printf("ffs_snapshot_mount: vget failed %d\n", error); 2000 continue; 2001 } 2002 ip = VTOI(vp); 2003 if (!IS_SNAPSHOT(ip) || ip->i_size == 2004 lblktosize(fs, howmany(fs->fs_size, fs->fs_frag))) { 2005 if (!IS_SNAPSHOT(ip)) { 2006 reason = "non-snapshot"; 2007 } else { 2008 reason = "old format snapshot"; 2009 (void)ffs_truncate(vp, (off_t)0, 0, NOCRED); 2010 (void)ffs_syncvnode(vp, MNT_WAIT, 0); 2011 } 2012 printf("ffs_snapshot_mount: %s inode %d\n", 2013 reason, fs->fs_snapinum[snaploc]); 2014 vput(vp); 2015 vp = NULL; 2016 for (loc = snaploc + 1; loc < FSMAXSNAP; loc++) { 2017 if (fs->fs_snapinum[loc] == 0) 2018 break; 2019 fs->fs_snapinum[loc - 1] = fs->fs_snapinum[loc]; 2020 } 2021 fs->fs_snapinum[loc - 1] = 0; 2022 snaploc--; 2023 continue; 2024 } 2025 /* 2026 * Acquire a lock on the snapdata structure, creating it if 2027 * necessary. 2028 */ 2029 sn = ffs_snapdata_acquire(devvp); 2030 /* 2031 * Change vnode to use shared snapshot lock instead of the 2032 * original private lock. 2033 */ 2034 vp->v_vnlock = &sn->sn_lock; 2035 lockmgr(&vp->v_lock, LK_RELEASE, NULL); 2036 /* 2037 * Link it onto the active snapshot list. 2038 */ 2039 VI_LOCK(devvp); 2040 if (ip->i_nextsnap.tqe_prev != 0) 2041 panic("ffs_snapshot_mount: %ju already on list", 2042 (uintmax_t)ip->i_number); 2043 else 2044 TAILQ_INSERT_TAIL(&sn->sn_head, ip, i_nextsnap); 2045 vp->v_vflag |= VV_SYSTEM; 2046 VI_UNLOCK(devvp); 2047 VOP_UNLOCK(vp, 0); 2048 lastvp = vp; 2049 } 2050 vp = lastvp; 2051 /* 2052 * No usable snapshots found. 2053 */ 2054 if (sn == NULL || vp == NULL) 2055 return; 2056 /* 2057 * Allocate the space for the block hints list. We always want to 2058 * use the list from the newest snapshot. 2059 */ 2060 auio.uio_iov = &aiov; 2061 auio.uio_iovcnt = 1; 2062 aiov.iov_base = (void *)&snaplistsize; 2063 aiov.iov_len = sizeof(snaplistsize); 2064 auio.uio_resid = aiov.iov_len; 2065 auio.uio_offset = 2066 lblktosize(fs, howmany(fs->fs_size, fs->fs_frag)); 2067 auio.uio_segflg = UIO_SYSSPACE; 2068 auio.uio_rw = UIO_READ; 2069 auio.uio_td = td; 2070 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2071 if ((error = VOP_READ(vp, &auio, IO_UNIT, td->td_ucred)) != 0) { 2072 printf("ffs_snapshot_mount: read_1 failed %d\n", error); 2073 VOP_UNLOCK(vp, 0); 2074 return; 2075 } 2076 snapblklist = malloc(snaplistsize * sizeof(daddr_t), 2077 M_UFSMNT, M_WAITOK); 2078 auio.uio_iovcnt = 1; 2079 aiov.iov_base = snapblklist; 2080 aiov.iov_len = snaplistsize * sizeof (daddr_t); 2081 auio.uio_resid = aiov.iov_len; 2082 auio.uio_offset -= sizeof(snaplistsize); 2083 if ((error = VOP_READ(vp, &auio, IO_UNIT, td->td_ucred)) != 0) { 2084 printf("ffs_snapshot_mount: read_2 failed %d\n", error); 2085 VOP_UNLOCK(vp, 0); 2086 free(snapblklist, M_UFSMNT); 2087 return; 2088 } 2089 VOP_UNLOCK(vp, 0); 2090 VI_LOCK(devvp); 2091 ASSERT_VOP_LOCKED(devvp, "ffs_snapshot_mount"); 2092 sn->sn_listsize = snaplistsize; 2093 sn->sn_blklist = (daddr_t *)snapblklist; 2094 devvp->v_vflag |= VV_COPYONWRITE; 2095 VI_UNLOCK(devvp); 2096 } 2097 2098 /* 2099 * Disassociate snapshot files when unmounting. 2100 */ 2101 void 2102 ffs_snapshot_unmount(mp) 2103 struct mount *mp; 2104 { 2105 struct vnode *devvp = VFSTOUFS(mp)->um_devvp; 2106 struct snapdata *sn; 2107 struct inode *xp; 2108 struct vnode *vp; 2109 2110 VI_LOCK(devvp); 2111 sn = devvp->v_rdev->si_snapdata; 2112 while (sn != NULL && (xp = TAILQ_FIRST(&sn->sn_head)) != NULL) { 2113 vp = ITOV(xp); 2114 TAILQ_REMOVE(&sn->sn_head, xp, i_nextsnap); 2115 xp->i_nextsnap.tqe_prev = 0; 2116 lockmgr(&sn->sn_lock, LK_INTERLOCK | LK_EXCLUSIVE, 2117 VI_MTX(devvp)); 2118 lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL); 2119 KASSERT(vp->v_vnlock == &sn->sn_lock, 2120 ("ffs_snapshot_unmount: lost lock mutation")); 2121 vp->v_vnlock = &vp->v_lock; 2122 lockmgr(&vp->v_lock, LK_RELEASE, NULL); 2123 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 2124 if (xp->i_effnlink > 0) 2125 vrele(vp); 2126 VI_LOCK(devvp); 2127 sn = devvp->v_rdev->si_snapdata; 2128 } 2129 try_free_snapdata(devvp); 2130 ASSERT_VOP_LOCKED(devvp, "ffs_snapshot_unmount"); 2131 } 2132 2133 /* 2134 * Check the buffer block to be belong to device buffer that shall be 2135 * locked after snaplk. devvp shall be locked on entry, and will be 2136 * leaved locked upon exit. 2137 */ 2138 static int 2139 ffs_bp_snapblk(devvp, bp) 2140 struct vnode *devvp; 2141 struct buf *bp; 2142 { 2143 struct snapdata *sn; 2144 struct fs *fs; 2145 ufs2_daddr_t lbn, *snapblklist; 2146 int lower, upper, mid; 2147 2148 ASSERT_VI_LOCKED(devvp, "ffs_bp_snapblk"); 2149 KASSERT(devvp->v_type == VCHR, ("Not a device %p", devvp)); 2150 sn = devvp->v_rdev->si_snapdata; 2151 if (sn == NULL || TAILQ_FIRST(&sn->sn_head) == NULL) 2152 return (0); 2153 fs = ITOFS(TAILQ_FIRST(&sn->sn_head)); 2154 lbn = fragstoblks(fs, dbtofsb(fs, bp->b_blkno)); 2155 snapblklist = sn->sn_blklist; 2156 upper = sn->sn_listsize - 1; 2157 lower = 1; 2158 while (lower <= upper) { 2159 mid = (lower + upper) / 2; 2160 if (snapblklist[mid] == lbn) 2161 break; 2162 if (snapblklist[mid] < lbn) 2163 lower = mid + 1; 2164 else 2165 upper = mid - 1; 2166 } 2167 if (lower <= upper) 2168 return (1); 2169 return (0); 2170 } 2171 2172 void 2173 ffs_bdflush(bo, bp) 2174 struct bufobj *bo; 2175 struct buf *bp; 2176 { 2177 struct thread *td; 2178 struct vnode *vp, *devvp; 2179 struct buf *nbp; 2180 int bp_bdskip; 2181 2182 if (bo->bo_dirty.bv_cnt <= dirtybufthresh) 2183 return; 2184 2185 td = curthread; 2186 vp = bp->b_vp; 2187 devvp = bo2vnode(bo); 2188 KASSERT(vp == devvp, ("devvp != vp %p %p", bo, bp)); 2189 2190 VI_LOCK(devvp); 2191 bp_bdskip = ffs_bp_snapblk(devvp, bp); 2192 if (bp_bdskip) 2193 bdwriteskip++; 2194 VI_UNLOCK(devvp); 2195 if (bo->bo_dirty.bv_cnt > dirtybufthresh + 10 && !bp_bdskip) { 2196 (void) VOP_FSYNC(vp, MNT_NOWAIT, td); 2197 altbufferflushes++; 2198 } else { 2199 BO_LOCK(bo); 2200 /* 2201 * Try to find a buffer to flush. 2202 */ 2203 TAILQ_FOREACH(nbp, &bo->bo_dirty.bv_hd, b_bobufs) { 2204 if ((nbp->b_vflags & BV_BKGRDINPROG) || 2205 BUF_LOCK(nbp, 2206 LK_EXCLUSIVE | LK_NOWAIT, NULL)) 2207 continue; 2208 if (bp == nbp) 2209 panic("bdwrite: found ourselves"); 2210 BO_UNLOCK(bo); 2211 /* 2212 * Don't countdeps with the bo lock 2213 * held. 2214 */ 2215 if (buf_countdeps(nbp, 0)) { 2216 BO_LOCK(bo); 2217 BUF_UNLOCK(nbp); 2218 continue; 2219 } 2220 if (bp_bdskip) { 2221 VI_LOCK(devvp); 2222 if (!ffs_bp_snapblk(vp, nbp)) { 2223 VI_UNLOCK(devvp); 2224 BO_LOCK(bo); 2225 BUF_UNLOCK(nbp); 2226 continue; 2227 } 2228 VI_UNLOCK(devvp); 2229 } 2230 if (nbp->b_flags & B_CLUSTEROK) { 2231 vfs_bio_awrite(nbp); 2232 } else { 2233 bremfree(nbp); 2234 bawrite(nbp); 2235 } 2236 dirtybufferflushes++; 2237 break; 2238 } 2239 if (nbp == NULL) 2240 BO_UNLOCK(bo); 2241 } 2242 } 2243 2244 /* 2245 * Check for need to copy block that is about to be written, 2246 * copying the block if necessary. 2247 */ 2248 int 2249 ffs_copyonwrite(devvp, bp) 2250 struct vnode *devvp; 2251 struct buf *bp; 2252 { 2253 struct snapdata *sn; 2254 struct buf *ibp, *cbp, *savedcbp = NULL; 2255 struct thread *td = curthread; 2256 struct fs *fs; 2257 struct inode *ip; 2258 struct vnode *vp = NULL; 2259 ufs2_daddr_t lbn, blkno, *snapblklist; 2260 int lower, upper, mid, indiroff, error = 0; 2261 int launched_async_io, prev_norunningbuf; 2262 long saved_runningbufspace; 2263 2264 if (devvp != bp->b_vp && IS_SNAPSHOT(VTOI(bp->b_vp))) 2265 return (0); /* Update on a snapshot file */ 2266 if (td->td_pflags & TDP_COWINPROGRESS) 2267 panic("ffs_copyonwrite: recursive call"); 2268 /* 2269 * First check to see if it is in the preallocated list. 2270 * By doing this check we avoid several potential deadlocks. 2271 */ 2272 VI_LOCK(devvp); 2273 sn = devvp->v_rdev->si_snapdata; 2274 if (sn == NULL || 2275 TAILQ_EMPTY(&sn->sn_head)) { 2276 VI_UNLOCK(devvp); 2277 return (0); /* No snapshot */ 2278 } 2279 ip = TAILQ_FIRST(&sn->sn_head); 2280 fs = ITOFS(ip); 2281 lbn = fragstoblks(fs, dbtofsb(fs, bp->b_blkno)); 2282 snapblklist = sn->sn_blklist; 2283 upper = sn->sn_listsize - 1; 2284 lower = 1; 2285 while (lower <= upper) { 2286 mid = (lower + upper) / 2; 2287 if (snapblklist[mid] == lbn) 2288 break; 2289 if (snapblklist[mid] < lbn) 2290 lower = mid + 1; 2291 else 2292 upper = mid - 1; 2293 } 2294 if (lower <= upper) { 2295 VI_UNLOCK(devvp); 2296 return (0); 2297 } 2298 launched_async_io = 0; 2299 prev_norunningbuf = td->td_pflags & TDP_NORUNNINGBUF; 2300 /* 2301 * Since I/O on bp isn't yet in progress and it may be blocked 2302 * for a long time waiting on snaplk, back it out of 2303 * runningbufspace, possibly waking other threads waiting for space. 2304 */ 2305 saved_runningbufspace = bp->b_runningbufspace; 2306 if (saved_runningbufspace != 0) 2307 runningbufwakeup(bp); 2308 /* 2309 * Not in the precomputed list, so check the snapshots. 2310 */ 2311 while (lockmgr(&sn->sn_lock, LK_INTERLOCK | LK_EXCLUSIVE | LK_SLEEPFAIL, 2312 VI_MTX(devvp)) != 0) { 2313 VI_LOCK(devvp); 2314 sn = devvp->v_rdev->si_snapdata; 2315 if (sn == NULL || 2316 TAILQ_EMPTY(&sn->sn_head)) { 2317 VI_UNLOCK(devvp); 2318 if (saved_runningbufspace != 0) { 2319 bp->b_runningbufspace = saved_runningbufspace; 2320 atomic_add_long(&runningbufspace, 2321 bp->b_runningbufspace); 2322 } 2323 return (0); /* Snapshot gone */ 2324 } 2325 } 2326 TAILQ_FOREACH(ip, &sn->sn_head, i_nextsnap) { 2327 vp = ITOV(ip); 2328 if (DOINGSOFTDEP(vp)) 2329 softdep_prealloc(vp, MNT_WAIT); 2330 /* 2331 * We ensure that everything of our own that needs to be 2332 * copied will be done at the time that ffs_snapshot is 2333 * called. Thus we can skip the check here which can 2334 * deadlock in doing the lookup in UFS_BALLOC. 2335 */ 2336 if (bp->b_vp == vp) 2337 continue; 2338 /* 2339 * Check to see if block needs to be copied. We do not have 2340 * to hold the snapshot lock while doing this lookup as it 2341 * will never require any additional allocations for the 2342 * snapshot inode. 2343 */ 2344 if (lbn < UFS_NDADDR) { 2345 blkno = DIP(ip, i_db[lbn]); 2346 } else { 2347 td->td_pflags |= TDP_COWINPROGRESS | TDP_NORUNNINGBUF; 2348 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn), 2349 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 2350 td->td_pflags &= ~TDP_COWINPROGRESS; 2351 if (error) 2352 break; 2353 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs); 2354 if (I_IS_UFS1(ip)) 2355 blkno=((ufs1_daddr_t *)(ibp->b_data))[indiroff]; 2356 else 2357 blkno=((ufs2_daddr_t *)(ibp->b_data))[indiroff]; 2358 bqrelse(ibp); 2359 } 2360 #ifdef INVARIANTS 2361 if (blkno == BLK_SNAP && bp->b_lblkno >= 0) 2362 panic("ffs_copyonwrite: bad copy block"); 2363 #endif 2364 if (blkno != 0) 2365 continue; 2366 /* 2367 * Allocate the block into which to do the copy. Since 2368 * multiple processes may all try to copy the same block, 2369 * we have to recheck our need to do a copy if we sleep 2370 * waiting for the lock. 2371 * 2372 * Because all snapshots on a filesystem share a single 2373 * lock, we ensure that we will never be in competition 2374 * with another process to allocate a block. 2375 */ 2376 td->td_pflags |= TDP_COWINPROGRESS | TDP_NORUNNINGBUF; 2377 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn), 2378 fs->fs_bsize, KERNCRED, 0, &cbp); 2379 td->td_pflags &= ~TDP_COWINPROGRESS; 2380 if (error) 2381 break; 2382 #ifdef DEBUG 2383 if (snapdebug) { 2384 printf("Copyonwrite: snapino %ju lbn %jd for ", 2385 (uintmax_t)ip->i_number, (intmax_t)lbn); 2386 if (bp->b_vp == devvp) 2387 printf("fs metadata"); 2388 else 2389 printf("inum %ju", 2390 (uintmax_t)VTOI(bp->b_vp)->i_number); 2391 printf(" lblkno %jd to blkno %jd\n", 2392 (intmax_t)bp->b_lblkno, (intmax_t)cbp->b_blkno); 2393 } 2394 #endif 2395 /* 2396 * If we have already read the old block contents, then 2397 * simply copy them to the new block. Note that we need 2398 * to synchronously write snapshots that have not been 2399 * unlinked, and hence will be visible after a crash, 2400 * to ensure their integrity. At a minimum we ensure the 2401 * integrity of the filesystem metadata, but use the 2402 * dopersistence sysctl-setable flag to decide on the 2403 * persistence needed for file content data. 2404 */ 2405 if (savedcbp != NULL) { 2406 bcopy(savedcbp->b_data, cbp->b_data, fs->fs_bsize); 2407 bawrite(cbp); 2408 if ((devvp == bp->b_vp || bp->b_vp->v_type == VDIR || 2409 dopersistence) && ip->i_effnlink > 0) 2410 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 2411 else 2412 launched_async_io = 1; 2413 continue; 2414 } 2415 /* 2416 * Otherwise, read the old block contents into the buffer. 2417 */ 2418 if ((error = readblock(vp, cbp, lbn)) != 0) { 2419 bzero(cbp->b_data, fs->fs_bsize); 2420 bawrite(cbp); 2421 if ((devvp == bp->b_vp || bp->b_vp->v_type == VDIR || 2422 dopersistence) && ip->i_effnlink > 0) 2423 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 2424 else 2425 launched_async_io = 1; 2426 break; 2427 } 2428 savedcbp = cbp; 2429 } 2430 /* 2431 * Note that we need to synchronously write snapshots that 2432 * have not been unlinked, and hence will be visible after 2433 * a crash, to ensure their integrity. At a minimum we 2434 * ensure the integrity of the filesystem metadata, but 2435 * use the dopersistence sysctl-setable flag to decide on 2436 * the persistence needed for file content data. 2437 */ 2438 if (savedcbp) { 2439 vp = savedcbp->b_vp; 2440 bawrite(savedcbp); 2441 if ((devvp == bp->b_vp || bp->b_vp->v_type == VDIR || 2442 dopersistence) && VTOI(vp)->i_effnlink > 0) 2443 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 2444 else 2445 launched_async_io = 1; 2446 } 2447 lockmgr(vp->v_vnlock, LK_RELEASE, NULL); 2448 td->td_pflags = (td->td_pflags & ~TDP_NORUNNINGBUF) | 2449 prev_norunningbuf; 2450 if (launched_async_io && (td->td_pflags & TDP_NORUNNINGBUF) == 0) 2451 waitrunningbufspace(); 2452 /* 2453 * I/O on bp will now be started, so count it in runningbufspace. 2454 */ 2455 if (saved_runningbufspace != 0) { 2456 bp->b_runningbufspace = saved_runningbufspace; 2457 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 2458 } 2459 return (error); 2460 } 2461 2462 /* 2463 * sync snapshots to force freework records waiting on snapshots to claim 2464 * blocks to free. 2465 */ 2466 void 2467 ffs_sync_snap(mp, waitfor) 2468 struct mount *mp; 2469 int waitfor; 2470 { 2471 struct snapdata *sn; 2472 struct vnode *devvp; 2473 struct vnode *vp; 2474 struct inode *ip; 2475 2476 devvp = VFSTOUFS(mp)->um_devvp; 2477 if ((devvp->v_vflag & VV_COPYONWRITE) == 0) 2478 return; 2479 for (;;) { 2480 VI_LOCK(devvp); 2481 sn = devvp->v_rdev->si_snapdata; 2482 if (sn == NULL) { 2483 VI_UNLOCK(devvp); 2484 return; 2485 } 2486 if (lockmgr(&sn->sn_lock, 2487 LK_INTERLOCK | LK_EXCLUSIVE | LK_SLEEPFAIL, 2488 VI_MTX(devvp)) == 0) 2489 break; 2490 } 2491 TAILQ_FOREACH(ip, &sn->sn_head, i_nextsnap) { 2492 vp = ITOV(ip); 2493 ffs_syncvnode(vp, waitfor, NO_INO_UPDT); 2494 } 2495 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 2496 } 2497 2498 /* 2499 * Read the specified block into the given buffer. 2500 * Much of this boiler-plate comes from bwrite(). 2501 */ 2502 static int 2503 readblock(vp, bp, lbn) 2504 struct vnode *vp; 2505 struct buf *bp; 2506 ufs2_daddr_t lbn; 2507 { 2508 struct inode *ip; 2509 struct bio *bip; 2510 struct fs *fs; 2511 2512 ip = VTOI(vp); 2513 fs = ITOFS(ip); 2514 2515 bip = g_alloc_bio(); 2516 bip->bio_cmd = BIO_READ; 2517 bip->bio_offset = dbtob(fsbtodb(fs, blkstofrags(fs, lbn))); 2518 bip->bio_data = bp->b_data; 2519 bip->bio_length = bp->b_bcount; 2520 bip->bio_done = NULL; 2521 2522 g_io_request(bip, ITODEVVP(ip)->v_bufobj.bo_private); 2523 bp->b_error = biowait(bip, "snaprdb"); 2524 g_destroy_bio(bip); 2525 return (bp->b_error); 2526 } 2527 2528 #endif 2529 2530 /* 2531 * Process file deletes that were deferred by ufs_inactive() due to 2532 * the file system being suspended. Transfer IN_LAZYACCESS into 2533 * IN_MODIFIED for vnodes that were accessed during suspension. 2534 */ 2535 void 2536 process_deferred_inactive(struct mount *mp) 2537 { 2538 struct vnode *vp, *mvp; 2539 struct inode *ip; 2540 struct thread *td; 2541 int error; 2542 2543 td = curthread; 2544 (void) vn_start_secondary_write(NULL, &mp, V_WAIT); 2545 loop: 2546 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 2547 /* 2548 * IN_LAZYACCESS is checked here without holding any 2549 * vnode lock, but this flag is set only while holding 2550 * vnode interlock. 2551 */ 2552 if (vp->v_type == VNON || 2553 ((VTOI(vp)->i_flag & IN_LAZYACCESS) == 0 && 2554 ((vp->v_iflag & VI_OWEINACT) == 0 || vp->v_usecount > 0))) { 2555 VI_UNLOCK(vp); 2556 continue; 2557 } 2558 vholdl(vp); 2559 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 2560 if (error != 0) { 2561 vdrop(vp); 2562 if (error == ENOENT) 2563 continue; /* vnode recycled */ 2564 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 2565 goto loop; 2566 } 2567 ip = VTOI(vp); 2568 if ((ip->i_flag & IN_LAZYACCESS) != 0) { 2569 ip->i_flag &= ~IN_LAZYACCESS; 2570 ip->i_flag |= IN_MODIFIED; 2571 } 2572 VI_LOCK(vp); 2573 if ((vp->v_iflag & VI_OWEINACT) == 0 || vp->v_usecount > 0) { 2574 VI_UNLOCK(vp); 2575 VOP_UNLOCK(vp, 0); 2576 vdrop(vp); 2577 continue; 2578 } 2579 vinactive(vp, td); 2580 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 2581 ("process_deferred_inactive: got VI_OWEINACT")); 2582 VI_UNLOCK(vp); 2583 VOP_UNLOCK(vp, 0); 2584 vdrop(vp); 2585 } 2586 vn_finished_secondary_write(mp); 2587 } 2588 2589 #ifndef NO_FFS_SNAPSHOT 2590 2591 static struct snapdata * 2592 ffs_snapdata_alloc(void) 2593 { 2594 struct snapdata *sn; 2595 2596 /* 2597 * Fetch a snapdata from the free list if there is one available. 2598 */ 2599 mtx_lock(&snapfree_lock); 2600 sn = LIST_FIRST(&snapfree); 2601 if (sn != NULL) 2602 LIST_REMOVE(sn, sn_link); 2603 mtx_unlock(&snapfree_lock); 2604 if (sn != NULL) 2605 return (sn); 2606 /* 2607 * If there were no free snapdatas allocate one. 2608 */ 2609 sn = malloc(sizeof *sn, M_UFSMNT, M_WAITOK | M_ZERO); 2610 TAILQ_INIT(&sn->sn_head); 2611 lockinit(&sn->sn_lock, PVFS, "snaplk", VLKTIMEOUT, 2612 LK_CANRECURSE | LK_NOSHARE); 2613 return (sn); 2614 } 2615 2616 /* 2617 * The snapdata is never freed because we can not be certain that 2618 * there are no threads sleeping on the snap lock. Persisting 2619 * them permanently avoids costly synchronization in ffs_lock(). 2620 */ 2621 static void 2622 ffs_snapdata_free(struct snapdata *sn) 2623 { 2624 mtx_lock(&snapfree_lock); 2625 LIST_INSERT_HEAD(&snapfree, sn, sn_link); 2626 mtx_unlock(&snapfree_lock); 2627 } 2628 2629 /* Try to free snapdata associated with devvp */ 2630 static void 2631 try_free_snapdata(struct vnode *devvp) 2632 { 2633 struct snapdata *sn; 2634 ufs2_daddr_t *snapblklist; 2635 2636 ASSERT_VI_LOCKED(devvp, "try_free_snapdata"); 2637 sn = devvp->v_rdev->si_snapdata; 2638 2639 if (sn == NULL || TAILQ_FIRST(&sn->sn_head) != NULL || 2640 (devvp->v_vflag & VV_COPYONWRITE) == 0) { 2641 VI_UNLOCK(devvp); 2642 return; 2643 } 2644 2645 devvp->v_rdev->si_snapdata = NULL; 2646 devvp->v_vflag &= ~VV_COPYONWRITE; 2647 lockmgr(&sn->sn_lock, LK_DRAIN|LK_INTERLOCK, VI_MTX(devvp)); 2648 snapblklist = sn->sn_blklist; 2649 sn->sn_blklist = NULL; 2650 sn->sn_listsize = 0; 2651 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 2652 if (snapblklist != NULL) 2653 free(snapblklist, M_UFSMNT); 2654 ffs_snapdata_free(sn); 2655 } 2656 2657 static struct snapdata * 2658 ffs_snapdata_acquire(struct vnode *devvp) 2659 { 2660 struct snapdata *nsn, *sn; 2661 int error; 2662 2663 /* 2664 * Allocate a free snapdata. This is done before acquiring the 2665 * devvp lock to avoid allocation while the devvp interlock is 2666 * held. 2667 */ 2668 nsn = ffs_snapdata_alloc(); 2669 2670 for (;;) { 2671 VI_LOCK(devvp); 2672 sn = devvp->v_rdev->si_snapdata; 2673 if (sn == NULL) { 2674 /* 2675 * This is the first snapshot on this 2676 * filesystem and we use our pre-allocated 2677 * snapdata. Publish sn with the sn_lock 2678 * owned by us, to avoid the race. 2679 */ 2680 error = lockmgr(&nsn->sn_lock, LK_EXCLUSIVE | 2681 LK_NOWAIT, NULL); 2682 if (error != 0) 2683 panic("leaked sn, lockmgr error %d", error); 2684 sn = devvp->v_rdev->si_snapdata = nsn; 2685 VI_UNLOCK(devvp); 2686 nsn = NULL; 2687 break; 2688 } 2689 2690 /* 2691 * There is a snapshots which already exists on this 2692 * filesystem, grab a reference to the common lock. 2693 */ 2694 error = lockmgr(&sn->sn_lock, LK_INTERLOCK | 2695 LK_EXCLUSIVE | LK_SLEEPFAIL, VI_MTX(devvp)); 2696 if (error == 0) 2697 break; 2698 } 2699 2700 /* 2701 * Free any unused snapdata. 2702 */ 2703 if (nsn != NULL) 2704 ffs_snapdata_free(nsn); 2705 2706 return (sn); 2707 } 2708 2709 #endif 2710