1 /*- 2 * Copyright 2000 Marshall Kirk McKusick. All Rights Reserved. 3 * 4 * Further information about snapshots can be obtained from: 5 * 6 * Marshall Kirk McKusick http://www.mckusick.com/softdep/ 7 * 1614 Oxford Street mckusick@mckusick.com 8 * Berkeley, CA 94709-1608 +1-510-843-9542 9 * USA 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 21 * THIS SOFTWARE IS PROVIDED BY MARSHALL KIRK MCKUSICK ``AS IS'' AND ANY 22 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 23 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 24 * DISCLAIMED. IN NO EVENT SHALL MARSHALL KIRK MCKUSICK BE LIABLE FOR 25 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)ffs_snapshot.c 8.11 (McKusick) 7/23/00 34 */ 35 36 #include <sys/cdefs.h> 37 __FBSDID("$FreeBSD$"); 38 39 #include "opt_quota.h" 40 41 #include <sys/param.h> 42 #include <sys/kernel.h> 43 #include <sys/systm.h> 44 #include <sys/conf.h> 45 #include <sys/bio.h> 46 #include <sys/buf.h> 47 #include <sys/fcntl.h> 48 #include <sys/proc.h> 49 #include <sys/namei.h> 50 #include <sys/sched.h> 51 #include <sys/stat.h> 52 #include <sys/malloc.h> 53 #include <sys/mount.h> 54 #include <sys/resource.h> 55 #include <sys/resourcevar.h> 56 #include <sys/rwlock.h> 57 #include <sys/vnode.h> 58 59 #include <geom/geom.h> 60 61 #include <ufs/ufs/extattr.h> 62 #include <ufs/ufs/quota.h> 63 #include <ufs/ufs/ufsmount.h> 64 #include <ufs/ufs/inode.h> 65 #include <ufs/ufs/ufs_extern.h> 66 67 #include <ufs/ffs/fs.h> 68 #include <ufs/ffs/ffs_extern.h> 69 70 #define KERNCRED thread0.td_ucred 71 #define DEBUG 1 72 73 #include "opt_ffs.h" 74 75 #ifdef NO_FFS_SNAPSHOT 76 int 77 ffs_snapshot(mp, snapfile) 78 struct mount *mp; 79 char *snapfile; 80 { 81 return (EINVAL); 82 } 83 84 int 85 ffs_snapblkfree(fs, devvp, bno, size, inum, vtype, wkhd) 86 struct fs *fs; 87 struct vnode *devvp; 88 ufs2_daddr_t bno; 89 long size; 90 ino_t inum; 91 enum vtype vtype; 92 struct workhead *wkhd; 93 { 94 return (EINVAL); 95 } 96 97 void 98 ffs_snapremove(vp) 99 struct vnode *vp; 100 { 101 } 102 103 void 104 ffs_snapshot_mount(mp) 105 struct mount *mp; 106 { 107 } 108 109 void 110 ffs_snapshot_unmount(mp) 111 struct mount *mp; 112 { 113 } 114 115 void 116 ffs_snapgone(ip) 117 struct inode *ip; 118 { 119 } 120 121 int 122 ffs_copyonwrite(devvp, bp) 123 struct vnode *devvp; 124 struct buf *bp; 125 { 126 return (EINVAL); 127 } 128 129 void 130 ffs_sync_snap(mp, waitfor) 131 struct mount *mp; 132 int waitfor; 133 { 134 } 135 136 #else 137 FEATURE(ffs_snapshot, "FFS snapshot support"); 138 139 LIST_HEAD(, snapdata) snapfree; 140 static struct mtx snapfree_lock; 141 MTX_SYSINIT(ffs_snapfree, &snapfree_lock, "snapdata free list", MTX_DEF); 142 143 static int cgaccount(int, struct vnode *, struct buf *, int); 144 static int expunge_ufs1(struct vnode *, struct inode *, struct fs *, 145 int (*)(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, struct fs *, 146 ufs_lbn_t, int), int, int); 147 static int indiracct_ufs1(struct vnode *, struct vnode *, int, 148 ufs1_daddr_t, ufs_lbn_t, ufs_lbn_t, ufs_lbn_t, ufs_lbn_t, struct fs *, 149 int (*)(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, struct fs *, 150 ufs_lbn_t, int), int); 151 static int fullacct_ufs1(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, 152 struct fs *, ufs_lbn_t, int); 153 static int snapacct_ufs1(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, 154 struct fs *, ufs_lbn_t, int); 155 static int mapacct_ufs1(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, 156 struct fs *, ufs_lbn_t, int); 157 static int expunge_ufs2(struct vnode *, struct inode *, struct fs *, 158 int (*)(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, struct fs *, 159 ufs_lbn_t, int), int, int); 160 static int indiracct_ufs2(struct vnode *, struct vnode *, int, 161 ufs2_daddr_t, ufs_lbn_t, ufs_lbn_t, ufs_lbn_t, ufs_lbn_t, struct fs *, 162 int (*)(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, struct fs *, 163 ufs_lbn_t, int), int); 164 static int fullacct_ufs2(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, 165 struct fs *, ufs_lbn_t, int); 166 static int snapacct_ufs2(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, 167 struct fs *, ufs_lbn_t, int); 168 static int mapacct_ufs2(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, 169 struct fs *, ufs_lbn_t, int); 170 static int readblock(struct vnode *vp, struct buf *, ufs2_daddr_t); 171 static void try_free_snapdata(struct vnode *devvp); 172 static struct snapdata *ffs_snapdata_acquire(struct vnode *devvp); 173 static int ffs_bp_snapblk(struct vnode *, struct buf *); 174 175 /* 176 * To ensure the consistency of snapshots across crashes, we must 177 * synchronously write out copied blocks before allowing the 178 * originals to be modified. Because of the rather severe speed 179 * penalty that this imposes, the code normally only ensures 180 * persistence for the filesystem metadata contained within a 181 * snapshot. Setting the following flag allows this crash 182 * persistence to be enabled for file contents. 183 */ 184 int dopersistence = 0; 185 186 #ifdef DEBUG 187 #include <sys/sysctl.h> 188 SYSCTL_INT(_debug, OID_AUTO, dopersistence, CTLFLAG_RW, &dopersistence, 0, ""); 189 static int snapdebug = 0; 190 SYSCTL_INT(_debug, OID_AUTO, snapdebug, CTLFLAG_RW, &snapdebug, 0, ""); 191 int collectsnapstats = 0; 192 SYSCTL_INT(_debug, OID_AUTO, collectsnapstats, CTLFLAG_RW, &collectsnapstats, 193 0, ""); 194 #endif /* DEBUG */ 195 196 /* 197 * Create a snapshot file and initialize it for the filesystem. 198 */ 199 int 200 ffs_snapshot(mp, snapfile) 201 struct mount *mp; 202 char *snapfile; 203 { 204 ufs2_daddr_t numblks, blkno, *blkp, *snapblklist; 205 int error, cg, snaploc; 206 int i, size, len, loc; 207 ufs2_daddr_t blockno; 208 uint64_t flag; 209 struct timespec starttime = {0, 0}, endtime; 210 char saved_nice = 0; 211 long redo = 0, snaplistsize = 0; 212 int32_t *lp; 213 void *space; 214 struct fs *copy_fs = NULL, *fs; 215 struct thread *td = curthread; 216 struct inode *ip, *xp; 217 struct buf *bp, *nbp, *ibp; 218 struct nameidata nd; 219 struct mount *wrtmp; 220 struct vattr vat; 221 struct vnode *vp, *xvp, *mvp, *devvp; 222 struct uio auio; 223 struct iovec aiov; 224 struct snapdata *sn; 225 struct ufsmount *ump; 226 227 ump = VFSTOUFS(mp); 228 fs = ump->um_fs; 229 sn = NULL; 230 /* 231 * At the moment, journaled soft updates cannot support 232 * taking snapshots. 233 */ 234 if (MOUNTEDSUJ(mp)) { 235 vfs_mount_error(mp, "%s: Snapshots are not yet supported when " 236 "running with journaled soft updates", fs->fs_fsmnt); 237 return (EOPNOTSUPP); 238 } 239 MNT_ILOCK(mp); 240 flag = mp->mnt_flag; 241 MNT_IUNLOCK(mp); 242 /* 243 * Need to serialize access to snapshot code per filesystem. 244 */ 245 /* 246 * Assign a snapshot slot in the superblock. 247 */ 248 UFS_LOCK(ump); 249 for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++) 250 if (fs->fs_snapinum[snaploc] == 0) 251 break; 252 UFS_UNLOCK(ump); 253 if (snaploc == FSMAXSNAP) 254 return (ENOSPC); 255 /* 256 * Create the snapshot file. 257 */ 258 restart: 259 NDINIT(&nd, CREATE, LOCKPARENT | LOCKLEAF | NOCACHE, UIO_SYSSPACE, 260 snapfile, td); 261 if ((error = namei(&nd)) != 0) 262 return (error); 263 if (nd.ni_vp != NULL) { 264 vput(nd.ni_vp); 265 error = EEXIST; 266 } 267 if (nd.ni_dvp->v_mount != mp) 268 error = EXDEV; 269 if (error) { 270 NDFREE(&nd, NDF_ONLY_PNBUF); 271 if (nd.ni_dvp == nd.ni_vp) 272 vrele(nd.ni_dvp); 273 else 274 vput(nd.ni_dvp); 275 return (error); 276 } 277 VATTR_NULL(&vat); 278 vat.va_type = VREG; 279 vat.va_mode = S_IRUSR; 280 vat.va_vaflags |= VA_EXCLUSIVE; 281 if (VOP_GETWRITEMOUNT(nd.ni_dvp, &wrtmp)) 282 wrtmp = NULL; 283 if (wrtmp != mp) 284 panic("ffs_snapshot: mount mismatch"); 285 vfs_rel(wrtmp); 286 if (vn_start_write(NULL, &wrtmp, V_NOWAIT) != 0) { 287 NDFREE(&nd, NDF_ONLY_PNBUF); 288 vput(nd.ni_dvp); 289 if ((error = vn_start_write(NULL, &wrtmp, 290 V_XSLEEP | PCATCH)) != 0) 291 return (error); 292 goto restart; 293 } 294 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vat); 295 VOP_UNLOCK(nd.ni_dvp, 0); 296 if (error) { 297 NDFREE(&nd, NDF_ONLY_PNBUF); 298 vn_finished_write(wrtmp); 299 vrele(nd.ni_dvp); 300 return (error); 301 } 302 vp = nd.ni_vp; 303 vp->v_vflag |= VV_SYSTEM; 304 ip = VTOI(vp); 305 devvp = ITODEVVP(ip); 306 /* 307 * Allocate and copy the last block contents so as to be able 308 * to set size to that of the filesystem. 309 */ 310 numblks = howmany(fs->fs_size, fs->fs_frag); 311 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(numblks - 1)), 312 fs->fs_bsize, KERNCRED, BA_CLRBUF, &bp); 313 if (error) 314 goto out; 315 ip->i_size = lblktosize(fs, (off_t)numblks); 316 DIP_SET(ip, i_size, ip->i_size); 317 ip->i_flag |= IN_CHANGE | IN_UPDATE; 318 error = readblock(vp, bp, numblks - 1); 319 bawrite(bp); 320 if (error != 0) 321 goto out; 322 /* 323 * Preallocate critical data structures so that we can copy 324 * them in without further allocation after we suspend all 325 * operations on the filesystem. We would like to just release 326 * the allocated buffers without writing them since they will 327 * be filled in below once we are ready to go, but this upsets 328 * the soft update code, so we go ahead and write the new buffers. 329 * 330 * Allocate all indirect blocks and mark all of them as not 331 * needing to be copied. 332 */ 333 for (blkno = UFS_NDADDR; blkno < numblks; blkno += NINDIR(fs)) { 334 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)blkno), 335 fs->fs_bsize, td->td_ucred, BA_METAONLY, &ibp); 336 if (error) 337 goto out; 338 bawrite(ibp); 339 } 340 /* 341 * Allocate copies for the superblock and its summary information. 342 */ 343 error = UFS_BALLOC(vp, fs->fs_sblockloc, fs->fs_sbsize, KERNCRED, 344 0, &nbp); 345 if (error) 346 goto out; 347 bawrite(nbp); 348 blkno = fragstoblks(fs, fs->fs_csaddr); 349 len = howmany(fs->fs_cssize, fs->fs_bsize); 350 for (loc = 0; loc < len; loc++) { 351 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(blkno + loc)), 352 fs->fs_bsize, KERNCRED, 0, &nbp); 353 if (error) 354 goto out; 355 bawrite(nbp); 356 } 357 /* 358 * Allocate all cylinder group blocks. 359 */ 360 for (cg = 0; cg < fs->fs_ncg; cg++) { 361 error = UFS_BALLOC(vp, lfragtosize(fs, cgtod(fs, cg)), 362 fs->fs_bsize, KERNCRED, 0, &nbp); 363 if (error) 364 goto out; 365 bawrite(nbp); 366 if (cg % 10 == 0) 367 ffs_syncvnode(vp, MNT_WAIT, 0); 368 } 369 /* 370 * Copy all the cylinder group maps. Although the 371 * filesystem is still active, we hope that only a few 372 * cylinder groups will change between now and when we 373 * suspend operations. Thus, we will be able to quickly 374 * touch up the few cylinder groups that changed during 375 * the suspension period. 376 */ 377 len = howmany(fs->fs_ncg, NBBY); 378 space = malloc(len, M_DEVBUF, M_WAITOK|M_ZERO); 379 UFS_LOCK(ump); 380 fs->fs_active = space; 381 UFS_UNLOCK(ump); 382 for (cg = 0; cg < fs->fs_ncg; cg++) { 383 error = UFS_BALLOC(vp, lfragtosize(fs, cgtod(fs, cg)), 384 fs->fs_bsize, KERNCRED, 0, &nbp); 385 if (error) 386 goto out; 387 error = cgaccount(cg, vp, nbp, 1); 388 bawrite(nbp); 389 if (cg % 10 == 0) 390 ffs_syncvnode(vp, MNT_WAIT, 0); 391 if (error) 392 goto out; 393 } 394 /* 395 * Change inode to snapshot type file. 396 */ 397 ip->i_flags |= SF_SNAPSHOT; 398 DIP_SET(ip, i_flags, ip->i_flags); 399 ip->i_flag |= IN_CHANGE | IN_UPDATE; 400 /* 401 * Ensure that the snapshot is completely on disk. 402 * Since we have marked it as a snapshot it is safe to 403 * unlock it as no process will be allowed to write to it. 404 */ 405 if ((error = ffs_syncvnode(vp, MNT_WAIT, 0)) != 0) 406 goto out; 407 VOP_UNLOCK(vp, 0); 408 /* 409 * All allocations are done, so we can now snapshot the system. 410 * 411 * Recind nice scheduling while running with the filesystem suspended. 412 */ 413 if (td->td_proc->p_nice > 0) { 414 struct proc *p; 415 416 p = td->td_proc; 417 PROC_LOCK(p); 418 saved_nice = p->p_nice; 419 sched_nice(p, 0); 420 PROC_UNLOCK(p); 421 } 422 /* 423 * Suspend operation on filesystem. 424 */ 425 for (;;) { 426 vn_finished_write(wrtmp); 427 if ((error = vfs_write_suspend(vp->v_mount, 0)) != 0) { 428 vn_start_write(NULL, &wrtmp, V_WAIT); 429 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 430 goto out; 431 } 432 if (mp->mnt_kern_flag & MNTK_SUSPENDED) 433 break; 434 vn_start_write(NULL, &wrtmp, V_WAIT); 435 } 436 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 437 if (ip->i_effnlink == 0) { 438 error = ENOENT; /* Snapshot file unlinked */ 439 goto out1; 440 } 441 if (collectsnapstats) 442 nanotime(&starttime); 443 444 /* The last block might have changed. Copy it again to be sure. */ 445 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(numblks - 1)), 446 fs->fs_bsize, KERNCRED, BA_CLRBUF, &bp); 447 if (error != 0) 448 goto out1; 449 error = readblock(vp, bp, numblks - 1); 450 bp->b_flags |= B_VALIDSUSPWRT; 451 bawrite(bp); 452 if (error != 0) 453 goto out1; 454 /* 455 * First, copy all the cylinder group maps that have changed. 456 */ 457 for (cg = 0; cg < fs->fs_ncg; cg++) { 458 if ((ACTIVECGNUM(fs, cg) & ACTIVECGOFF(cg)) != 0) 459 continue; 460 redo++; 461 error = UFS_BALLOC(vp, lfragtosize(fs, cgtod(fs, cg)), 462 fs->fs_bsize, KERNCRED, 0, &nbp); 463 if (error) 464 goto out1; 465 error = cgaccount(cg, vp, nbp, 2); 466 bawrite(nbp); 467 if (error) 468 goto out1; 469 } 470 /* 471 * Grab a copy of the superblock and its summary information. 472 * We delay writing it until the suspension is released below. 473 */ 474 copy_fs = malloc((u_long)fs->fs_bsize, M_UFSMNT, M_WAITOK); 475 bcopy(fs, copy_fs, fs->fs_sbsize); 476 if ((fs->fs_flags & (FS_UNCLEAN | FS_NEEDSFSCK)) == 0) 477 copy_fs->fs_clean = 1; 478 size = fs->fs_bsize < SBLOCKSIZE ? fs->fs_bsize : SBLOCKSIZE; 479 if (fs->fs_sbsize < size) 480 bzero(&((char *)copy_fs)[fs->fs_sbsize], 481 size - fs->fs_sbsize); 482 size = blkroundup(fs, fs->fs_cssize); 483 if (fs->fs_contigsumsize > 0) 484 size += fs->fs_ncg * sizeof(int32_t); 485 space = malloc((u_long)size, M_UFSMNT, M_WAITOK); 486 copy_fs->fs_csp = space; 487 bcopy(fs->fs_csp, copy_fs->fs_csp, fs->fs_cssize); 488 space = (char *)space + fs->fs_cssize; 489 loc = howmany(fs->fs_cssize, fs->fs_fsize); 490 i = fs->fs_frag - loc % fs->fs_frag; 491 len = (i == fs->fs_frag) ? 0 : i * fs->fs_fsize; 492 if (len > 0) { 493 if ((error = bread(devvp, fsbtodb(fs, fs->fs_csaddr + loc), 494 len, KERNCRED, &bp)) != 0) { 495 brelse(bp); 496 free(copy_fs->fs_csp, M_UFSMNT); 497 free(copy_fs, M_UFSMNT); 498 copy_fs = NULL; 499 goto out1; 500 } 501 bcopy(bp->b_data, space, (u_int)len); 502 space = (char *)space + len; 503 bp->b_flags |= B_INVAL | B_NOCACHE; 504 brelse(bp); 505 } 506 if (fs->fs_contigsumsize > 0) { 507 copy_fs->fs_maxcluster = lp = space; 508 for (i = 0; i < fs->fs_ncg; i++) 509 *lp++ = fs->fs_contigsumsize; 510 } 511 /* 512 * We must check for active files that have been unlinked 513 * (e.g., with a zero link count). We have to expunge all 514 * trace of these files from the snapshot so that they are 515 * not reclaimed prematurely by fsck or unnecessarily dumped. 516 * We turn off the MNTK_SUSPENDED flag to avoid a panic from 517 * spec_strategy about writing on a suspended filesystem. 518 * Note that we skip unlinked snapshot files as they will 519 * be handled separately below. 520 * 521 * We also calculate the needed size for the snapshot list. 522 */ 523 snaplistsize = fs->fs_ncg + howmany(fs->fs_cssize, fs->fs_bsize) + 524 FSMAXSNAP + 1 /* superblock */ + 1 /* last block */ + 1 /* size */; 525 MNT_ILOCK(mp); 526 mp->mnt_kern_flag &= ~MNTK_SUSPENDED; 527 MNT_IUNLOCK(mp); 528 loop: 529 MNT_VNODE_FOREACH_ALL(xvp, mp, mvp) { 530 if ((xvp->v_usecount == 0 && 531 (xvp->v_iflag & (VI_OWEINACT | VI_DOINGINACT)) == 0) || 532 xvp->v_type == VNON || 533 IS_SNAPSHOT(VTOI(xvp))) { 534 VI_UNLOCK(xvp); 535 continue; 536 } 537 /* 538 * We can skip parent directory vnode because it must have 539 * this snapshot file in it. 540 */ 541 if (xvp == nd.ni_dvp) { 542 VI_UNLOCK(xvp); 543 continue; 544 } 545 vholdl(xvp); 546 if (vn_lock(xvp, LK_EXCLUSIVE | LK_INTERLOCK) != 0) { 547 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 548 vdrop(xvp); 549 goto loop; 550 } 551 VI_LOCK(xvp); 552 if (xvp->v_usecount == 0 && 553 (xvp->v_iflag & (VI_OWEINACT | VI_DOINGINACT)) == 0) { 554 VI_UNLOCK(xvp); 555 VOP_UNLOCK(xvp, 0); 556 vdrop(xvp); 557 continue; 558 } 559 VI_UNLOCK(xvp); 560 if (snapdebug) 561 vn_printf(xvp, "ffs_snapshot: busy vnode "); 562 if (VOP_GETATTR(xvp, &vat, td->td_ucred) == 0 && 563 vat.va_nlink > 0) { 564 VOP_UNLOCK(xvp, 0); 565 vdrop(xvp); 566 continue; 567 } 568 xp = VTOI(xvp); 569 if (ffs_checkfreefile(copy_fs, vp, xp->i_number)) { 570 VOP_UNLOCK(xvp, 0); 571 vdrop(xvp); 572 continue; 573 } 574 /* 575 * If there is a fragment, clear it here. 576 */ 577 blkno = 0; 578 loc = howmany(xp->i_size, fs->fs_bsize) - 1; 579 if (loc < UFS_NDADDR) { 580 len = fragroundup(fs, blkoff(fs, xp->i_size)); 581 if (len != 0 && len < fs->fs_bsize) { 582 ffs_blkfree(ump, copy_fs, vp, 583 DIP(xp, i_db[loc]), len, xp->i_number, 584 xvp->v_type, NULL); 585 blkno = DIP(xp, i_db[loc]); 586 DIP_SET(xp, i_db[loc], 0); 587 } 588 } 589 snaplistsize += 1; 590 if (I_IS_UFS1(xp)) 591 error = expunge_ufs1(vp, xp, copy_fs, fullacct_ufs1, 592 BLK_NOCOPY, 1); 593 else 594 error = expunge_ufs2(vp, xp, copy_fs, fullacct_ufs2, 595 BLK_NOCOPY, 1); 596 if (blkno) 597 DIP_SET(xp, i_db[loc], blkno); 598 if (!error) 599 error = ffs_freefile(ump, copy_fs, vp, xp->i_number, 600 xp->i_mode, NULL); 601 VOP_UNLOCK(xvp, 0); 602 vdrop(xvp); 603 if (error) { 604 free(copy_fs->fs_csp, M_UFSMNT); 605 free(copy_fs, M_UFSMNT); 606 copy_fs = NULL; 607 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 608 goto out1; 609 } 610 } 611 /* 612 * Erase the journal file from the snapshot. 613 */ 614 if (fs->fs_flags & FS_SUJ) { 615 error = softdep_journal_lookup(mp, &xvp); 616 if (error) { 617 free(copy_fs->fs_csp, M_UFSMNT); 618 free(copy_fs, M_UFSMNT); 619 copy_fs = NULL; 620 goto out1; 621 } 622 xp = VTOI(xvp); 623 if (I_IS_UFS1(xp)) 624 error = expunge_ufs1(vp, xp, copy_fs, fullacct_ufs1, 625 BLK_NOCOPY, 0); 626 else 627 error = expunge_ufs2(vp, xp, copy_fs, fullacct_ufs2, 628 BLK_NOCOPY, 0); 629 vput(xvp); 630 } 631 /* 632 * Acquire a lock on the snapdata structure, creating it if necessary. 633 */ 634 sn = ffs_snapdata_acquire(devvp); 635 /* 636 * Change vnode to use shared snapshot lock instead of the original 637 * private lock. 638 */ 639 vp->v_vnlock = &sn->sn_lock; 640 lockmgr(&vp->v_lock, LK_RELEASE, NULL); 641 xp = TAILQ_FIRST(&sn->sn_head); 642 /* 643 * If this is the first snapshot on this filesystem, then we need 644 * to allocate the space for the list of preallocated snapshot blocks. 645 * This list will be refined below, but this preliminary one will 646 * keep us out of deadlock until the full one is ready. 647 */ 648 if (xp == NULL) { 649 snapblklist = malloc(snaplistsize * sizeof(daddr_t), 650 M_UFSMNT, M_WAITOK); 651 blkp = &snapblklist[1]; 652 *blkp++ = lblkno(fs, fs->fs_sblockloc); 653 blkno = fragstoblks(fs, fs->fs_csaddr); 654 for (cg = 0; cg < fs->fs_ncg; cg++) { 655 if (fragstoblks(fs, cgtod(fs, cg) > blkno)) 656 break; 657 *blkp++ = fragstoblks(fs, cgtod(fs, cg)); 658 } 659 len = howmany(fs->fs_cssize, fs->fs_bsize); 660 for (loc = 0; loc < len; loc++) 661 *blkp++ = blkno + loc; 662 for (; cg < fs->fs_ncg; cg++) 663 *blkp++ = fragstoblks(fs, cgtod(fs, cg)); 664 snapblklist[0] = blkp - snapblklist; 665 VI_LOCK(devvp); 666 if (sn->sn_blklist != NULL) 667 panic("ffs_snapshot: non-empty list"); 668 sn->sn_blklist = snapblklist; 669 sn->sn_listsize = blkp - snapblklist; 670 VI_UNLOCK(devvp); 671 } 672 /* 673 * Record snapshot inode. Since this is the newest snapshot, 674 * it must be placed at the end of the list. 675 */ 676 VI_LOCK(devvp); 677 fs->fs_snapinum[snaploc] = ip->i_number; 678 if (ip->i_nextsnap.tqe_prev != 0) 679 panic("ffs_snapshot: %ju already on list", 680 (uintmax_t)ip->i_number); 681 TAILQ_INSERT_TAIL(&sn->sn_head, ip, i_nextsnap); 682 devvp->v_vflag |= VV_COPYONWRITE; 683 VI_UNLOCK(devvp); 684 ASSERT_VOP_LOCKED(vp, "ffs_snapshot vp"); 685 out1: 686 KASSERT((sn != NULL && copy_fs != NULL && error == 0) || 687 (sn == NULL && copy_fs == NULL && error != 0), 688 ("email phk@ and mckusick@")); 689 /* 690 * Resume operation on filesystem. 691 */ 692 vfs_write_resume(vp->v_mount, VR_START_WRITE | VR_NO_SUSPCLR); 693 if (collectsnapstats && starttime.tv_sec > 0) { 694 nanotime(&endtime); 695 timespecsub(&endtime, &starttime); 696 printf("%s: suspended %ld.%03ld sec, redo %ld of %d\n", 697 vp->v_mount->mnt_stat.f_mntonname, (long)endtime.tv_sec, 698 endtime.tv_nsec / 1000000, redo, fs->fs_ncg); 699 } 700 if (copy_fs == NULL) 701 goto out; 702 /* 703 * Copy allocation information from all the snapshots in 704 * this snapshot and then expunge them from its view. 705 */ 706 TAILQ_FOREACH(xp, &sn->sn_head, i_nextsnap) { 707 if (xp == ip) 708 break; 709 if (I_IS_UFS1(xp)) 710 error = expunge_ufs1(vp, xp, fs, snapacct_ufs1, 711 BLK_SNAP, 0); 712 else 713 error = expunge_ufs2(vp, xp, fs, snapacct_ufs2, 714 BLK_SNAP, 0); 715 if (error == 0 && xp->i_effnlink == 0) { 716 error = ffs_freefile(ump, 717 copy_fs, 718 vp, 719 xp->i_number, 720 xp->i_mode, NULL); 721 } 722 if (error) { 723 fs->fs_snapinum[snaploc] = 0; 724 goto done; 725 } 726 } 727 /* 728 * Allocate space for the full list of preallocated snapshot blocks. 729 */ 730 snapblklist = malloc(snaplistsize * sizeof(daddr_t), 731 M_UFSMNT, M_WAITOK); 732 ip->i_snapblklist = &snapblklist[1]; 733 /* 734 * Expunge the blocks used by the snapshots from the set of 735 * blocks marked as used in the snapshot bitmaps. Also, collect 736 * the list of allocated blocks in i_snapblklist. 737 */ 738 if (I_IS_UFS1(ip)) 739 error = expunge_ufs1(vp, ip, copy_fs, mapacct_ufs1, 740 BLK_SNAP, 0); 741 else 742 error = expunge_ufs2(vp, ip, copy_fs, mapacct_ufs2, 743 BLK_SNAP, 0); 744 if (error) { 745 fs->fs_snapinum[snaploc] = 0; 746 free(snapblklist, M_UFSMNT); 747 goto done; 748 } 749 if (snaplistsize < ip->i_snapblklist - snapblklist) 750 panic("ffs_snapshot: list too small"); 751 snaplistsize = ip->i_snapblklist - snapblklist; 752 snapblklist[0] = snaplistsize; 753 ip->i_snapblklist = 0; 754 /* 755 * Write out the list of allocated blocks to the end of the snapshot. 756 */ 757 auio.uio_iov = &aiov; 758 auio.uio_iovcnt = 1; 759 aiov.iov_base = (void *)snapblklist; 760 aiov.iov_len = snaplistsize * sizeof(daddr_t); 761 auio.uio_resid = aiov.iov_len; 762 auio.uio_offset = ip->i_size; 763 auio.uio_segflg = UIO_SYSSPACE; 764 auio.uio_rw = UIO_WRITE; 765 auio.uio_td = td; 766 if ((error = VOP_WRITE(vp, &auio, IO_UNIT, td->td_ucred)) != 0) { 767 fs->fs_snapinum[snaploc] = 0; 768 free(snapblklist, M_UFSMNT); 769 goto done; 770 } 771 /* 772 * Write the superblock and its summary information 773 * to the snapshot. 774 */ 775 blkno = fragstoblks(fs, fs->fs_csaddr); 776 len = howmany(fs->fs_cssize, fs->fs_bsize); 777 space = copy_fs->fs_csp; 778 for (loc = 0; loc < len; loc++) { 779 error = bread(vp, blkno + loc, fs->fs_bsize, KERNCRED, &nbp); 780 if (error) { 781 brelse(nbp); 782 fs->fs_snapinum[snaploc] = 0; 783 free(snapblklist, M_UFSMNT); 784 goto done; 785 } 786 bcopy(space, nbp->b_data, fs->fs_bsize); 787 space = (char *)space + fs->fs_bsize; 788 bawrite(nbp); 789 } 790 error = bread(vp, lblkno(fs, fs->fs_sblockloc), fs->fs_bsize, 791 KERNCRED, &nbp); 792 if (error) { 793 brelse(nbp); 794 } else { 795 loc = blkoff(fs, fs->fs_sblockloc); 796 bcopy((char *)copy_fs, &nbp->b_data[loc], (u_int)fs->fs_sbsize); 797 bawrite(nbp); 798 } 799 /* 800 * As this is the newest list, it is the most inclusive, so 801 * should replace the previous list. 802 */ 803 VI_LOCK(devvp); 804 space = sn->sn_blklist; 805 sn->sn_blklist = snapblklist; 806 sn->sn_listsize = snaplistsize; 807 VI_UNLOCK(devvp); 808 if (space != NULL) 809 free(space, M_UFSMNT); 810 /* 811 * Preallocate all the direct blocks in the snapshot inode so 812 * that we never have to write the inode itself to commit an 813 * update to the contents of the snapshot. Note that once 814 * created, the size of the snapshot will never change, so 815 * there will never be a need to write the inode except to 816 * update the non-integrity-critical time fields and 817 * allocated-block count. 818 */ 819 for (blockno = 0; blockno < UFS_NDADDR; blockno++) { 820 if (DIP(ip, i_db[blockno]) != 0) 821 continue; 822 error = UFS_BALLOC(vp, lblktosize(fs, blockno), 823 fs->fs_bsize, KERNCRED, BA_CLRBUF, &bp); 824 if (error) 825 break; 826 error = readblock(vp, bp, blockno); 827 bawrite(bp); 828 if (error != 0) 829 break; 830 } 831 done: 832 free(copy_fs->fs_csp, M_UFSMNT); 833 free(copy_fs, M_UFSMNT); 834 copy_fs = NULL; 835 out: 836 NDFREE(&nd, NDF_ONLY_PNBUF); 837 if (saved_nice > 0) { 838 struct proc *p; 839 840 p = td->td_proc; 841 PROC_LOCK(p); 842 sched_nice(td->td_proc, saved_nice); 843 PROC_UNLOCK(td->td_proc); 844 } 845 UFS_LOCK(ump); 846 if (fs->fs_active != 0) { 847 free(fs->fs_active, M_DEVBUF); 848 fs->fs_active = 0; 849 } 850 UFS_UNLOCK(ump); 851 MNT_ILOCK(mp); 852 mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | (flag & ~MNT_QUOTA); 853 MNT_IUNLOCK(mp); 854 if (error) 855 (void) ffs_truncate(vp, (off_t)0, 0, NOCRED); 856 (void) ffs_syncvnode(vp, MNT_WAIT, 0); 857 if (error) 858 vput(vp); 859 else 860 VOP_UNLOCK(vp, 0); 861 vrele(nd.ni_dvp); 862 vn_finished_write(wrtmp); 863 process_deferred_inactive(mp); 864 return (error); 865 } 866 867 /* 868 * Copy a cylinder group map. All the unallocated blocks are marked 869 * BLK_NOCOPY so that the snapshot knows that it need not copy them 870 * if they are later written. If passno is one, then this is a first 871 * pass, so only setting needs to be done. If passno is 2, then this 872 * is a revision to a previous pass which must be undone as the 873 * replacement pass is done. 874 */ 875 static int 876 cgaccount(cg, vp, nbp, passno) 877 int cg; 878 struct vnode *vp; 879 struct buf *nbp; 880 int passno; 881 { 882 struct buf *bp, *ibp; 883 struct inode *ip; 884 struct cg *cgp; 885 struct fs *fs; 886 ufs2_daddr_t base, numblks; 887 int error, len, loc, indiroff; 888 889 ip = VTOI(vp); 890 fs = ITOFS(ip); 891 if ((error = ffs_getcg(fs, ITODEVVP(ip), cg, &bp, &cgp)) != 0) 892 return (error); 893 UFS_LOCK(ITOUMP(ip)); 894 ACTIVESET(fs, cg); 895 /* 896 * Recomputation of summary information might not have been performed 897 * at mount time. Sync up summary information for current cylinder 898 * group while data is in memory to ensure that result of background 899 * fsck is slightly more consistent. 900 */ 901 fs->fs_cs(fs, cg) = cgp->cg_cs; 902 UFS_UNLOCK(ITOUMP(ip)); 903 bcopy(bp->b_data, nbp->b_data, fs->fs_cgsize); 904 if (fs->fs_cgsize < fs->fs_bsize) 905 bzero(&nbp->b_data[fs->fs_cgsize], 906 fs->fs_bsize - fs->fs_cgsize); 907 cgp = (struct cg *)nbp->b_data; 908 bqrelse(bp); 909 if (passno == 2) 910 nbp->b_flags |= B_VALIDSUSPWRT; 911 numblks = howmany(fs->fs_size, fs->fs_frag); 912 len = howmany(fs->fs_fpg, fs->fs_frag); 913 base = cgbase(fs, cg) / fs->fs_frag; 914 if (base + len >= numblks) 915 len = numblks - base - 1; 916 loc = 0; 917 if (base < UFS_NDADDR) { 918 for ( ; loc < UFS_NDADDR; loc++) { 919 if (ffs_isblock(fs, cg_blksfree(cgp), loc)) 920 DIP_SET(ip, i_db[loc], BLK_NOCOPY); 921 else if (passno == 2 && DIP(ip, i_db[loc])== BLK_NOCOPY) 922 DIP_SET(ip, i_db[loc], 0); 923 else if (passno == 1 && DIP(ip, i_db[loc])== BLK_NOCOPY) 924 panic("ffs_snapshot: lost direct block"); 925 } 926 } 927 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(base + loc)), 928 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 929 if (error) { 930 goto out; 931 } 932 indiroff = (base + loc - UFS_NDADDR) % NINDIR(fs); 933 for ( ; loc < len; loc++, indiroff++) { 934 if (indiroff >= NINDIR(fs)) { 935 if (passno == 2) 936 ibp->b_flags |= B_VALIDSUSPWRT; 937 bawrite(ibp); 938 error = UFS_BALLOC(vp, 939 lblktosize(fs, (off_t)(base + loc)), 940 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 941 if (error) { 942 goto out; 943 } 944 indiroff = 0; 945 } 946 if (I_IS_UFS1(ip)) { 947 if (ffs_isblock(fs, cg_blksfree(cgp), loc)) 948 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] = 949 BLK_NOCOPY; 950 else if (passno == 2 && ((ufs1_daddr_t *)(ibp->b_data)) 951 [indiroff] == BLK_NOCOPY) 952 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] = 0; 953 else if (passno == 1 && ((ufs1_daddr_t *)(ibp->b_data)) 954 [indiroff] == BLK_NOCOPY) 955 panic("ffs_snapshot: lost indirect block"); 956 continue; 957 } 958 if (ffs_isblock(fs, cg_blksfree(cgp), loc)) 959 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = BLK_NOCOPY; 960 else if (passno == 2 && 961 ((ufs2_daddr_t *)(ibp->b_data)) [indiroff] == BLK_NOCOPY) 962 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = 0; 963 else if (passno == 1 && 964 ((ufs2_daddr_t *)(ibp->b_data)) [indiroff] == BLK_NOCOPY) 965 panic("ffs_snapshot: lost indirect block"); 966 } 967 if (passno == 2) 968 ibp->b_flags |= B_VALIDSUSPWRT; 969 bdwrite(ibp); 970 out: 971 /* 972 * We have to calculate the crc32c here rather than just setting the 973 * BX_CYLGRP b_xflags because the allocation of the block for the 974 * the cylinder group map will always be a full size block (fs_bsize) 975 * even though the cylinder group may be smaller (fs_cgsize). The 976 * crc32c must be computed only over fs_cgsize whereas the BX_CYLGRP 977 * flag causes it to be computed over the size of the buffer. 978 */ 979 if ((fs->fs_metackhash & CK_CYLGRP) != 0) { 980 ((struct cg *)nbp->b_data)->cg_ckhash = 0; 981 ((struct cg *)nbp->b_data)->cg_ckhash = 982 calculate_crc32c(~0L, nbp->b_data, fs->fs_cgsize); 983 } 984 return (error); 985 } 986 987 /* 988 * Before expunging a snapshot inode, note all the 989 * blocks that it claims with BLK_SNAP so that fsck will 990 * be able to account for those blocks properly and so 991 * that this snapshot knows that it need not copy them 992 * if the other snapshot holding them is freed. This code 993 * is reproduced once each for UFS1 and UFS2. 994 */ 995 static int 996 expunge_ufs1(snapvp, cancelip, fs, acctfunc, expungetype, clearmode) 997 struct vnode *snapvp; 998 struct inode *cancelip; 999 struct fs *fs; 1000 int (*acctfunc)(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, 1001 struct fs *, ufs_lbn_t, int); 1002 int expungetype; 1003 int clearmode; 1004 { 1005 int i, error, indiroff; 1006 ufs_lbn_t lbn, rlbn; 1007 ufs2_daddr_t len, blkno, numblks, blksperindir; 1008 struct ufs1_dinode *dip; 1009 struct thread *td = curthread; 1010 struct buf *bp; 1011 1012 /* 1013 * Prepare to expunge the inode. If its inode block has not 1014 * yet been copied, then allocate and fill the copy. 1015 */ 1016 lbn = fragstoblks(fs, ino_to_fsba(fs, cancelip->i_number)); 1017 blkno = 0; 1018 if (lbn < UFS_NDADDR) { 1019 blkno = VTOI(snapvp)->i_din1->di_db[lbn]; 1020 } else { 1021 if (DOINGSOFTDEP(snapvp)) 1022 softdep_prealloc(snapvp, MNT_WAIT); 1023 td->td_pflags |= TDP_COWINPROGRESS; 1024 error = ffs_balloc_ufs1(snapvp, lblktosize(fs, (off_t)lbn), 1025 fs->fs_bsize, KERNCRED, BA_METAONLY, &bp); 1026 td->td_pflags &= ~TDP_COWINPROGRESS; 1027 if (error) 1028 return (error); 1029 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs); 1030 blkno = ((ufs1_daddr_t *)(bp->b_data))[indiroff]; 1031 bqrelse(bp); 1032 } 1033 if (blkno != 0) { 1034 if ((error = bread(snapvp, lbn, fs->fs_bsize, KERNCRED, &bp))) 1035 return (error); 1036 } else { 1037 error = ffs_balloc_ufs1(snapvp, lblktosize(fs, (off_t)lbn), 1038 fs->fs_bsize, KERNCRED, 0, &bp); 1039 if (error) 1040 return (error); 1041 if ((error = readblock(snapvp, bp, lbn)) != 0) 1042 return (error); 1043 } 1044 /* 1045 * Set a snapshot inode to be a zero length file, regular files 1046 * or unlinked snapshots to be completely unallocated. 1047 */ 1048 dip = (struct ufs1_dinode *)bp->b_data + 1049 ino_to_fsbo(fs, cancelip->i_number); 1050 if (clearmode || cancelip->i_effnlink == 0) 1051 dip->di_mode = 0; 1052 dip->di_size = 0; 1053 dip->di_blocks = 0; 1054 dip->di_flags &= ~SF_SNAPSHOT; 1055 bzero(&dip->di_db[0], (UFS_NDADDR + UFS_NIADDR) * sizeof(ufs1_daddr_t)); 1056 bdwrite(bp); 1057 /* 1058 * Now go through and expunge all the blocks in the file 1059 * using the function requested. 1060 */ 1061 numblks = howmany(cancelip->i_size, fs->fs_bsize); 1062 if ((error = (*acctfunc)(snapvp, &cancelip->i_din1->di_db[0], 1063 &cancelip->i_din1->di_db[UFS_NDADDR], fs, 0, expungetype))) 1064 return (error); 1065 if ((error = (*acctfunc)(snapvp, &cancelip->i_din1->di_ib[0], 1066 &cancelip->i_din1->di_ib[UFS_NIADDR], fs, -1, expungetype))) 1067 return (error); 1068 blksperindir = 1; 1069 lbn = -UFS_NDADDR; 1070 len = numblks - UFS_NDADDR; 1071 rlbn = UFS_NDADDR; 1072 for (i = 0; len > 0 && i < UFS_NIADDR; i++) { 1073 error = indiracct_ufs1(snapvp, ITOV(cancelip), i, 1074 cancelip->i_din1->di_ib[i], lbn, rlbn, len, 1075 blksperindir, fs, acctfunc, expungetype); 1076 if (error) 1077 return (error); 1078 blksperindir *= NINDIR(fs); 1079 lbn -= blksperindir + 1; 1080 len -= blksperindir; 1081 rlbn += blksperindir; 1082 } 1083 return (0); 1084 } 1085 1086 /* 1087 * Descend an indirect block chain for vnode cancelvp accounting for all 1088 * its indirect blocks in snapvp. 1089 */ 1090 static int 1091 indiracct_ufs1(snapvp, cancelvp, level, blkno, lbn, rlbn, remblks, 1092 blksperindir, fs, acctfunc, expungetype) 1093 struct vnode *snapvp; 1094 struct vnode *cancelvp; 1095 int level; 1096 ufs1_daddr_t blkno; 1097 ufs_lbn_t lbn; 1098 ufs_lbn_t rlbn; 1099 ufs_lbn_t remblks; 1100 ufs_lbn_t blksperindir; 1101 struct fs *fs; 1102 int (*acctfunc)(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, 1103 struct fs *, ufs_lbn_t, int); 1104 int expungetype; 1105 { 1106 int error, num, i; 1107 ufs_lbn_t subblksperindir; 1108 struct indir indirs[UFS_NIADDR + 2]; 1109 ufs1_daddr_t last, *bap; 1110 struct buf *bp; 1111 1112 if (blkno == 0) { 1113 if (expungetype == BLK_NOCOPY) 1114 return (0); 1115 panic("indiracct_ufs1: missing indir"); 1116 } 1117 if ((error = ufs_getlbns(cancelvp, rlbn, indirs, &num)) != 0) 1118 return (error); 1119 if (lbn != indirs[num - 1 - level].in_lbn || num < 2) 1120 panic("indiracct_ufs1: botched params"); 1121 /* 1122 * We have to expand bread here since it will deadlock looking 1123 * up the block number for any blocks that are not in the cache. 1124 */ 1125 bp = getblk(cancelvp, lbn, fs->fs_bsize, 0, 0, 0); 1126 bp->b_blkno = fsbtodb(fs, blkno); 1127 if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0 && 1128 (error = readblock(cancelvp, bp, fragstoblks(fs, blkno)))) { 1129 brelse(bp); 1130 return (error); 1131 } 1132 /* 1133 * Account for the block pointers in this indirect block. 1134 */ 1135 last = howmany(remblks, blksperindir); 1136 if (last > NINDIR(fs)) 1137 last = NINDIR(fs); 1138 bap = malloc(fs->fs_bsize, M_DEVBUF, M_WAITOK); 1139 bcopy(bp->b_data, (caddr_t)bap, fs->fs_bsize); 1140 bqrelse(bp); 1141 error = (*acctfunc)(snapvp, &bap[0], &bap[last], fs, 1142 level == 0 ? rlbn : -1, expungetype); 1143 if (error || level == 0) 1144 goto out; 1145 /* 1146 * Account for the block pointers in each of the indirect blocks 1147 * in the levels below us. 1148 */ 1149 subblksperindir = blksperindir / NINDIR(fs); 1150 for (lbn++, level--, i = 0; i < last; i++) { 1151 error = indiracct_ufs1(snapvp, cancelvp, level, bap[i], lbn, 1152 rlbn, remblks, subblksperindir, fs, acctfunc, expungetype); 1153 if (error) 1154 goto out; 1155 rlbn += blksperindir; 1156 lbn -= blksperindir; 1157 remblks -= blksperindir; 1158 } 1159 out: 1160 free(bap, M_DEVBUF); 1161 return (error); 1162 } 1163 1164 /* 1165 * Do both snap accounting and map accounting. 1166 */ 1167 static int 1168 fullacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, exptype) 1169 struct vnode *vp; 1170 ufs1_daddr_t *oldblkp, *lastblkp; 1171 struct fs *fs; 1172 ufs_lbn_t lblkno; 1173 int exptype; /* BLK_SNAP or BLK_NOCOPY */ 1174 { 1175 int error; 1176 1177 if ((error = snapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, exptype))) 1178 return (error); 1179 return (mapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, exptype)); 1180 } 1181 1182 /* 1183 * Identify a set of blocks allocated in a snapshot inode. 1184 */ 1185 static int 1186 snapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, expungetype) 1187 struct vnode *vp; 1188 ufs1_daddr_t *oldblkp, *lastblkp; 1189 struct fs *fs; 1190 ufs_lbn_t lblkno; 1191 int expungetype; /* BLK_SNAP or BLK_NOCOPY */ 1192 { 1193 struct inode *ip = VTOI(vp); 1194 ufs1_daddr_t blkno, *blkp; 1195 ufs_lbn_t lbn; 1196 struct buf *ibp; 1197 int error; 1198 1199 for ( ; oldblkp < lastblkp; oldblkp++) { 1200 blkno = *oldblkp; 1201 if (blkno == 0 || blkno == BLK_NOCOPY || blkno == BLK_SNAP) 1202 continue; 1203 lbn = fragstoblks(fs, blkno); 1204 if (lbn < UFS_NDADDR) { 1205 blkp = &ip->i_din1->di_db[lbn]; 1206 ip->i_flag |= IN_CHANGE | IN_UPDATE; 1207 } else { 1208 error = ffs_balloc_ufs1(vp, lblktosize(fs, (off_t)lbn), 1209 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 1210 if (error) 1211 return (error); 1212 blkp = &((ufs1_daddr_t *)(ibp->b_data)) 1213 [(lbn - UFS_NDADDR) % NINDIR(fs)]; 1214 } 1215 /* 1216 * If we are expunging a snapshot vnode and we 1217 * find a block marked BLK_NOCOPY, then it is 1218 * one that has been allocated to this snapshot after 1219 * we took our current snapshot and can be ignored. 1220 */ 1221 if (expungetype == BLK_SNAP && *blkp == BLK_NOCOPY) { 1222 if (lbn >= UFS_NDADDR) 1223 brelse(ibp); 1224 } else { 1225 if (*blkp != 0) 1226 panic("snapacct_ufs1: bad block"); 1227 *blkp = expungetype; 1228 if (lbn >= UFS_NDADDR) 1229 bdwrite(ibp); 1230 } 1231 } 1232 return (0); 1233 } 1234 1235 /* 1236 * Account for a set of blocks allocated in a snapshot inode. 1237 */ 1238 static int 1239 mapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, expungetype) 1240 struct vnode *vp; 1241 ufs1_daddr_t *oldblkp, *lastblkp; 1242 struct fs *fs; 1243 ufs_lbn_t lblkno; 1244 int expungetype; 1245 { 1246 ufs1_daddr_t blkno; 1247 struct inode *ip; 1248 ino_t inum; 1249 int acctit; 1250 1251 ip = VTOI(vp); 1252 inum = ip->i_number; 1253 if (lblkno == -1) 1254 acctit = 0; 1255 else 1256 acctit = 1; 1257 for ( ; oldblkp < lastblkp; oldblkp++, lblkno++) { 1258 blkno = *oldblkp; 1259 if (blkno == 0 || blkno == BLK_NOCOPY) 1260 continue; 1261 if (acctit && expungetype == BLK_SNAP && blkno != BLK_SNAP) 1262 *ip->i_snapblklist++ = lblkno; 1263 if (blkno == BLK_SNAP) 1264 blkno = blkstofrags(fs, lblkno); 1265 ffs_blkfree(ITOUMP(ip), fs, vp, blkno, fs->fs_bsize, inum, 1266 vp->v_type, NULL); 1267 } 1268 return (0); 1269 } 1270 1271 /* 1272 * Before expunging a snapshot inode, note all the 1273 * blocks that it claims with BLK_SNAP so that fsck will 1274 * be able to account for those blocks properly and so 1275 * that this snapshot knows that it need not copy them 1276 * if the other snapshot holding them is freed. This code 1277 * is reproduced once each for UFS1 and UFS2. 1278 */ 1279 static int 1280 expunge_ufs2(snapvp, cancelip, fs, acctfunc, expungetype, clearmode) 1281 struct vnode *snapvp; 1282 struct inode *cancelip; 1283 struct fs *fs; 1284 int (*acctfunc)(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, 1285 struct fs *, ufs_lbn_t, int); 1286 int expungetype; 1287 int clearmode; 1288 { 1289 int i, error, indiroff; 1290 ufs_lbn_t lbn, rlbn; 1291 ufs2_daddr_t len, blkno, numblks, blksperindir; 1292 struct ufs2_dinode *dip; 1293 struct thread *td = curthread; 1294 struct buf *bp; 1295 1296 /* 1297 * Prepare to expunge the inode. If its inode block has not 1298 * yet been copied, then allocate and fill the copy. 1299 */ 1300 lbn = fragstoblks(fs, ino_to_fsba(fs, cancelip->i_number)); 1301 blkno = 0; 1302 if (lbn < UFS_NDADDR) { 1303 blkno = VTOI(snapvp)->i_din2->di_db[lbn]; 1304 } else { 1305 if (DOINGSOFTDEP(snapvp)) 1306 softdep_prealloc(snapvp, MNT_WAIT); 1307 td->td_pflags |= TDP_COWINPROGRESS; 1308 error = ffs_balloc_ufs2(snapvp, lblktosize(fs, (off_t)lbn), 1309 fs->fs_bsize, KERNCRED, BA_METAONLY, &bp); 1310 td->td_pflags &= ~TDP_COWINPROGRESS; 1311 if (error) 1312 return (error); 1313 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs); 1314 blkno = ((ufs2_daddr_t *)(bp->b_data))[indiroff]; 1315 bqrelse(bp); 1316 } 1317 if (blkno != 0) { 1318 if ((error = bread(snapvp, lbn, fs->fs_bsize, KERNCRED, &bp))) 1319 return (error); 1320 } else { 1321 error = ffs_balloc_ufs2(snapvp, lblktosize(fs, (off_t)lbn), 1322 fs->fs_bsize, KERNCRED, 0, &bp); 1323 if (error) 1324 return (error); 1325 if ((error = readblock(snapvp, bp, lbn)) != 0) 1326 return (error); 1327 } 1328 /* 1329 * Set a snapshot inode to be a zero length file, regular files 1330 * to be completely unallocated. 1331 */ 1332 dip = (struct ufs2_dinode *)bp->b_data + 1333 ino_to_fsbo(fs, cancelip->i_number); 1334 if (clearmode || cancelip->i_effnlink == 0) 1335 dip->di_mode = 0; 1336 dip->di_size = 0; 1337 dip->di_blocks = 0; 1338 dip->di_flags &= ~SF_SNAPSHOT; 1339 bzero(&dip->di_db[0], (UFS_NDADDR + UFS_NIADDR) * sizeof(ufs2_daddr_t)); 1340 bdwrite(bp); 1341 /* 1342 * Now go through and expunge all the blocks in the file 1343 * using the function requested. 1344 */ 1345 numblks = howmany(cancelip->i_size, fs->fs_bsize); 1346 if ((error = (*acctfunc)(snapvp, &cancelip->i_din2->di_db[0], 1347 &cancelip->i_din2->di_db[UFS_NDADDR], fs, 0, expungetype))) 1348 return (error); 1349 if ((error = (*acctfunc)(snapvp, &cancelip->i_din2->di_ib[0], 1350 &cancelip->i_din2->di_ib[UFS_NIADDR], fs, -1, expungetype))) 1351 return (error); 1352 blksperindir = 1; 1353 lbn = -UFS_NDADDR; 1354 len = numblks - UFS_NDADDR; 1355 rlbn = UFS_NDADDR; 1356 for (i = 0; len > 0 && i < UFS_NIADDR; i++) { 1357 error = indiracct_ufs2(snapvp, ITOV(cancelip), i, 1358 cancelip->i_din2->di_ib[i], lbn, rlbn, len, 1359 blksperindir, fs, acctfunc, expungetype); 1360 if (error) 1361 return (error); 1362 blksperindir *= NINDIR(fs); 1363 lbn -= blksperindir + 1; 1364 len -= blksperindir; 1365 rlbn += blksperindir; 1366 } 1367 return (0); 1368 } 1369 1370 /* 1371 * Descend an indirect block chain for vnode cancelvp accounting for all 1372 * its indirect blocks in snapvp. 1373 */ 1374 static int 1375 indiracct_ufs2(snapvp, cancelvp, level, blkno, lbn, rlbn, remblks, 1376 blksperindir, fs, acctfunc, expungetype) 1377 struct vnode *snapvp; 1378 struct vnode *cancelvp; 1379 int level; 1380 ufs2_daddr_t blkno; 1381 ufs_lbn_t lbn; 1382 ufs_lbn_t rlbn; 1383 ufs_lbn_t remblks; 1384 ufs_lbn_t blksperindir; 1385 struct fs *fs; 1386 int (*acctfunc)(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, 1387 struct fs *, ufs_lbn_t, int); 1388 int expungetype; 1389 { 1390 int error, num, i; 1391 ufs_lbn_t subblksperindir; 1392 struct indir indirs[UFS_NIADDR + 2]; 1393 ufs2_daddr_t last, *bap; 1394 struct buf *bp; 1395 1396 if (blkno == 0) { 1397 if (expungetype == BLK_NOCOPY) 1398 return (0); 1399 panic("indiracct_ufs2: missing indir"); 1400 } 1401 if ((error = ufs_getlbns(cancelvp, rlbn, indirs, &num)) != 0) 1402 return (error); 1403 if (lbn != indirs[num - 1 - level].in_lbn || num < 2) 1404 panic("indiracct_ufs2: botched params"); 1405 /* 1406 * We have to expand bread here since it will deadlock looking 1407 * up the block number for any blocks that are not in the cache. 1408 */ 1409 bp = getblk(cancelvp, lbn, fs->fs_bsize, 0, 0, 0); 1410 bp->b_blkno = fsbtodb(fs, blkno); 1411 if ((bp->b_flags & B_CACHE) == 0 && 1412 (error = readblock(cancelvp, bp, fragstoblks(fs, blkno)))) { 1413 brelse(bp); 1414 return (error); 1415 } 1416 /* 1417 * Account for the block pointers in this indirect block. 1418 */ 1419 last = howmany(remblks, blksperindir); 1420 if (last > NINDIR(fs)) 1421 last = NINDIR(fs); 1422 bap = malloc(fs->fs_bsize, M_DEVBUF, M_WAITOK); 1423 bcopy(bp->b_data, (caddr_t)bap, fs->fs_bsize); 1424 bqrelse(bp); 1425 error = (*acctfunc)(snapvp, &bap[0], &bap[last], fs, 1426 level == 0 ? rlbn : -1, expungetype); 1427 if (error || level == 0) 1428 goto out; 1429 /* 1430 * Account for the block pointers in each of the indirect blocks 1431 * in the levels below us. 1432 */ 1433 subblksperindir = blksperindir / NINDIR(fs); 1434 for (lbn++, level--, i = 0; i < last; i++) { 1435 error = indiracct_ufs2(snapvp, cancelvp, level, bap[i], lbn, 1436 rlbn, remblks, subblksperindir, fs, acctfunc, expungetype); 1437 if (error) 1438 goto out; 1439 rlbn += blksperindir; 1440 lbn -= blksperindir; 1441 remblks -= blksperindir; 1442 } 1443 out: 1444 free(bap, M_DEVBUF); 1445 return (error); 1446 } 1447 1448 /* 1449 * Do both snap accounting and map accounting. 1450 */ 1451 static int 1452 fullacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, exptype) 1453 struct vnode *vp; 1454 ufs2_daddr_t *oldblkp, *lastblkp; 1455 struct fs *fs; 1456 ufs_lbn_t lblkno; 1457 int exptype; /* BLK_SNAP or BLK_NOCOPY */ 1458 { 1459 int error; 1460 1461 if ((error = snapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, exptype))) 1462 return (error); 1463 return (mapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, exptype)); 1464 } 1465 1466 /* 1467 * Identify a set of blocks allocated in a snapshot inode. 1468 */ 1469 static int 1470 snapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, expungetype) 1471 struct vnode *vp; 1472 ufs2_daddr_t *oldblkp, *lastblkp; 1473 struct fs *fs; 1474 ufs_lbn_t lblkno; 1475 int expungetype; /* BLK_SNAP or BLK_NOCOPY */ 1476 { 1477 struct inode *ip = VTOI(vp); 1478 ufs2_daddr_t blkno, *blkp; 1479 ufs_lbn_t lbn; 1480 struct buf *ibp; 1481 int error; 1482 1483 for ( ; oldblkp < lastblkp; oldblkp++) { 1484 blkno = *oldblkp; 1485 if (blkno == 0 || blkno == BLK_NOCOPY || blkno == BLK_SNAP) 1486 continue; 1487 lbn = fragstoblks(fs, blkno); 1488 if (lbn < UFS_NDADDR) { 1489 blkp = &ip->i_din2->di_db[lbn]; 1490 ip->i_flag |= IN_CHANGE | IN_UPDATE; 1491 } else { 1492 error = ffs_balloc_ufs2(vp, lblktosize(fs, (off_t)lbn), 1493 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 1494 if (error) 1495 return (error); 1496 blkp = &((ufs2_daddr_t *)(ibp->b_data)) 1497 [(lbn - UFS_NDADDR) % NINDIR(fs)]; 1498 } 1499 /* 1500 * If we are expunging a snapshot vnode and we 1501 * find a block marked BLK_NOCOPY, then it is 1502 * one that has been allocated to this snapshot after 1503 * we took our current snapshot and can be ignored. 1504 */ 1505 if (expungetype == BLK_SNAP && *blkp == BLK_NOCOPY) { 1506 if (lbn >= UFS_NDADDR) 1507 brelse(ibp); 1508 } else { 1509 if (*blkp != 0) 1510 panic("snapacct_ufs2: bad block"); 1511 *blkp = expungetype; 1512 if (lbn >= UFS_NDADDR) 1513 bdwrite(ibp); 1514 } 1515 } 1516 return (0); 1517 } 1518 1519 /* 1520 * Account for a set of blocks allocated in a snapshot inode. 1521 */ 1522 static int 1523 mapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, expungetype) 1524 struct vnode *vp; 1525 ufs2_daddr_t *oldblkp, *lastblkp; 1526 struct fs *fs; 1527 ufs_lbn_t lblkno; 1528 int expungetype; 1529 { 1530 ufs2_daddr_t blkno; 1531 struct inode *ip; 1532 ino_t inum; 1533 int acctit; 1534 1535 ip = VTOI(vp); 1536 inum = ip->i_number; 1537 if (lblkno == -1) 1538 acctit = 0; 1539 else 1540 acctit = 1; 1541 for ( ; oldblkp < lastblkp; oldblkp++, lblkno++) { 1542 blkno = *oldblkp; 1543 if (blkno == 0 || blkno == BLK_NOCOPY) 1544 continue; 1545 if (acctit && expungetype == BLK_SNAP && blkno != BLK_SNAP) 1546 *ip->i_snapblklist++ = lblkno; 1547 if (blkno == BLK_SNAP) 1548 blkno = blkstofrags(fs, lblkno); 1549 ffs_blkfree(ITOUMP(ip), fs, vp, blkno, fs->fs_bsize, inum, 1550 vp->v_type, NULL); 1551 } 1552 return (0); 1553 } 1554 1555 /* 1556 * Decrement extra reference on snapshot when last name is removed. 1557 * It will not be freed until the last open reference goes away. 1558 */ 1559 void 1560 ffs_snapgone(ip) 1561 struct inode *ip; 1562 { 1563 struct inode *xp; 1564 struct fs *fs; 1565 int snaploc; 1566 struct snapdata *sn; 1567 struct ufsmount *ump; 1568 1569 /* 1570 * Find snapshot in incore list. 1571 */ 1572 xp = NULL; 1573 sn = ITODEVVP(ip)->v_rdev->si_snapdata; 1574 if (sn != NULL) 1575 TAILQ_FOREACH(xp, &sn->sn_head, i_nextsnap) 1576 if (xp == ip) 1577 break; 1578 if (xp != NULL) 1579 vrele(ITOV(ip)); 1580 else if (snapdebug) 1581 printf("ffs_snapgone: lost snapshot vnode %ju\n", 1582 (uintmax_t)ip->i_number); 1583 /* 1584 * Delete snapshot inode from superblock. Keep list dense. 1585 */ 1586 ump = ITOUMP(ip); 1587 fs = ump->um_fs; 1588 UFS_LOCK(ump); 1589 for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++) 1590 if (fs->fs_snapinum[snaploc] == ip->i_number) 1591 break; 1592 if (snaploc < FSMAXSNAP) { 1593 for (snaploc++; snaploc < FSMAXSNAP; snaploc++) { 1594 if (fs->fs_snapinum[snaploc] == 0) 1595 break; 1596 fs->fs_snapinum[snaploc - 1] = fs->fs_snapinum[snaploc]; 1597 } 1598 fs->fs_snapinum[snaploc - 1] = 0; 1599 } 1600 UFS_UNLOCK(ump); 1601 } 1602 1603 /* 1604 * Prepare a snapshot file for being removed. 1605 */ 1606 void 1607 ffs_snapremove(vp) 1608 struct vnode *vp; 1609 { 1610 struct inode *ip; 1611 struct vnode *devvp; 1612 struct buf *ibp; 1613 struct fs *fs; 1614 ufs2_daddr_t numblks, blkno, dblk; 1615 int error, i, last, loc; 1616 struct snapdata *sn; 1617 1618 ip = VTOI(vp); 1619 fs = ITOFS(ip); 1620 devvp = ITODEVVP(ip); 1621 /* 1622 * If active, delete from incore list (this snapshot may 1623 * already have been in the process of being deleted, so 1624 * would not have been active). 1625 * 1626 * Clear copy-on-write flag if last snapshot. 1627 */ 1628 VI_LOCK(devvp); 1629 if (ip->i_nextsnap.tqe_prev != 0) { 1630 sn = devvp->v_rdev->si_snapdata; 1631 TAILQ_REMOVE(&sn->sn_head, ip, i_nextsnap); 1632 ip->i_nextsnap.tqe_prev = 0; 1633 VI_UNLOCK(devvp); 1634 lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL); 1635 for (i = 0; i < sn->sn_lock.lk_recurse; i++) 1636 lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL); 1637 KASSERT(vp->v_vnlock == &sn->sn_lock, 1638 ("ffs_snapremove: lost lock mutation")); 1639 vp->v_vnlock = &vp->v_lock; 1640 VI_LOCK(devvp); 1641 while (sn->sn_lock.lk_recurse > 0) 1642 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 1643 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 1644 try_free_snapdata(devvp); 1645 } else 1646 VI_UNLOCK(devvp); 1647 /* 1648 * Clear all BLK_NOCOPY fields. Pass any block claims to other 1649 * snapshots that want them (see ffs_snapblkfree below). 1650 */ 1651 for (blkno = 1; blkno < UFS_NDADDR; blkno++) { 1652 dblk = DIP(ip, i_db[blkno]); 1653 if (dblk == 0) 1654 continue; 1655 if (dblk == BLK_NOCOPY || dblk == BLK_SNAP) 1656 DIP_SET(ip, i_db[blkno], 0); 1657 else if ((dblk == blkstofrags(fs, blkno) && 1658 ffs_snapblkfree(fs, ITODEVVP(ip), dblk, fs->fs_bsize, 1659 ip->i_number, vp->v_type, NULL))) { 1660 DIP_SET(ip, i_blocks, DIP(ip, i_blocks) - 1661 btodb(fs->fs_bsize)); 1662 DIP_SET(ip, i_db[blkno], 0); 1663 } 1664 } 1665 numblks = howmany(ip->i_size, fs->fs_bsize); 1666 for (blkno = UFS_NDADDR; blkno < numblks; blkno += NINDIR(fs)) { 1667 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)blkno), 1668 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 1669 if (error) 1670 continue; 1671 if (fs->fs_size - blkno > NINDIR(fs)) 1672 last = NINDIR(fs); 1673 else 1674 last = fs->fs_size - blkno; 1675 for (loc = 0; loc < last; loc++) { 1676 if (I_IS_UFS1(ip)) { 1677 dblk = ((ufs1_daddr_t *)(ibp->b_data))[loc]; 1678 if (dblk == 0) 1679 continue; 1680 if (dblk == BLK_NOCOPY || dblk == BLK_SNAP) 1681 ((ufs1_daddr_t *)(ibp->b_data))[loc]= 0; 1682 else if ((dblk == blkstofrags(fs, blkno) && 1683 ffs_snapblkfree(fs, ITODEVVP(ip), dblk, 1684 fs->fs_bsize, ip->i_number, vp->v_type, 1685 NULL))) { 1686 ip->i_din1->di_blocks -= 1687 btodb(fs->fs_bsize); 1688 ((ufs1_daddr_t *)(ibp->b_data))[loc]= 0; 1689 } 1690 continue; 1691 } 1692 dblk = ((ufs2_daddr_t *)(ibp->b_data))[loc]; 1693 if (dblk == 0) 1694 continue; 1695 if (dblk == BLK_NOCOPY || dblk == BLK_SNAP) 1696 ((ufs2_daddr_t *)(ibp->b_data))[loc] = 0; 1697 else if ((dblk == blkstofrags(fs, blkno) && 1698 ffs_snapblkfree(fs, ITODEVVP(ip), dblk, 1699 fs->fs_bsize, ip->i_number, vp->v_type, NULL))) { 1700 ip->i_din2->di_blocks -= btodb(fs->fs_bsize); 1701 ((ufs2_daddr_t *)(ibp->b_data))[loc] = 0; 1702 } 1703 } 1704 bawrite(ibp); 1705 } 1706 /* 1707 * Clear snapshot flag and drop reference. 1708 */ 1709 ip->i_flags &= ~SF_SNAPSHOT; 1710 DIP_SET(ip, i_flags, ip->i_flags); 1711 ip->i_flag |= IN_CHANGE | IN_UPDATE; 1712 /* 1713 * The dirtied indirects must be written out before 1714 * softdep_setup_freeblocks() is called. Otherwise indir_trunc() 1715 * may find indirect pointers using the magic BLK_* values. 1716 */ 1717 if (DOINGSOFTDEP(vp)) 1718 ffs_syncvnode(vp, MNT_WAIT, 0); 1719 #ifdef QUOTA 1720 /* 1721 * Reenable disk quotas for ex-snapshot file. 1722 */ 1723 if (!getinoquota(ip)) 1724 (void) chkdq(ip, DIP(ip, i_blocks), KERNCRED, FORCE); 1725 #endif 1726 } 1727 1728 /* 1729 * Notification that a block is being freed. Return zero if the free 1730 * should be allowed to proceed. Return non-zero if the snapshot file 1731 * wants to claim the block. The block will be claimed if it is an 1732 * uncopied part of one of the snapshots. It will be freed if it is 1733 * either a BLK_NOCOPY or has already been copied in all of the snapshots. 1734 * If a fragment is being freed, then all snapshots that care about 1735 * it must make a copy since a snapshot file can only claim full sized 1736 * blocks. Note that if more than one snapshot file maps the block, 1737 * we can pick one at random to claim it. Since none of the snapshots 1738 * can change, we are assurred that they will all see the same unmodified 1739 * image. When deleting a snapshot file (see ffs_snapremove above), we 1740 * must push any of these claimed blocks to one of the other snapshots 1741 * that maps it. These claimed blocks are easily identified as they will 1742 * have a block number equal to their logical block number within the 1743 * snapshot. A copied block can never have this property because they 1744 * must always have been allocated from a BLK_NOCOPY location. 1745 */ 1746 int 1747 ffs_snapblkfree(fs, devvp, bno, size, inum, vtype, wkhd) 1748 struct fs *fs; 1749 struct vnode *devvp; 1750 ufs2_daddr_t bno; 1751 long size; 1752 ino_t inum; 1753 enum vtype vtype; 1754 struct workhead *wkhd; 1755 { 1756 struct buf *ibp, *cbp, *savedcbp = NULL; 1757 struct thread *td = curthread; 1758 struct inode *ip; 1759 struct vnode *vp = NULL; 1760 ufs_lbn_t lbn; 1761 ufs2_daddr_t blkno; 1762 int indiroff = 0, error = 0, claimedblk = 0; 1763 struct snapdata *sn; 1764 1765 lbn = fragstoblks(fs, bno); 1766 retry: 1767 VI_LOCK(devvp); 1768 sn = devvp->v_rdev->si_snapdata; 1769 if (sn == NULL) { 1770 VI_UNLOCK(devvp); 1771 return (0); 1772 } 1773 if (lockmgr(&sn->sn_lock, LK_INTERLOCK | LK_EXCLUSIVE | LK_SLEEPFAIL, 1774 VI_MTX(devvp)) != 0) 1775 goto retry; 1776 TAILQ_FOREACH(ip, &sn->sn_head, i_nextsnap) { 1777 vp = ITOV(ip); 1778 if (DOINGSOFTDEP(vp)) 1779 softdep_prealloc(vp, MNT_WAIT); 1780 /* 1781 * Lookup block being written. 1782 */ 1783 if (lbn < UFS_NDADDR) { 1784 blkno = DIP(ip, i_db[lbn]); 1785 } else { 1786 td->td_pflags |= TDP_COWINPROGRESS; 1787 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn), 1788 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 1789 td->td_pflags &= ~TDP_COWINPROGRESS; 1790 if (error) 1791 break; 1792 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs); 1793 if (I_IS_UFS1(ip)) 1794 blkno=((ufs1_daddr_t *)(ibp->b_data))[indiroff]; 1795 else 1796 blkno=((ufs2_daddr_t *)(ibp->b_data))[indiroff]; 1797 } 1798 /* 1799 * Check to see if block needs to be copied. 1800 */ 1801 if (blkno == 0) { 1802 /* 1803 * A block that we map is being freed. If it has not 1804 * been claimed yet, we will claim or copy it (below). 1805 */ 1806 claimedblk = 1; 1807 } else if (blkno == BLK_SNAP) { 1808 /* 1809 * No previous snapshot claimed the block, 1810 * so it will be freed and become a BLK_NOCOPY 1811 * (don't care) for us. 1812 */ 1813 if (claimedblk) 1814 panic("snapblkfree: inconsistent block type"); 1815 if (lbn < UFS_NDADDR) { 1816 DIP_SET(ip, i_db[lbn], BLK_NOCOPY); 1817 ip->i_flag |= IN_CHANGE | IN_UPDATE; 1818 } else if (I_IS_UFS1(ip)) { 1819 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] = 1820 BLK_NOCOPY; 1821 bdwrite(ibp); 1822 } else { 1823 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = 1824 BLK_NOCOPY; 1825 bdwrite(ibp); 1826 } 1827 continue; 1828 } else /* BLK_NOCOPY or default */ { 1829 /* 1830 * If the snapshot has already copied the block 1831 * (default), or does not care about the block, 1832 * it is not needed. 1833 */ 1834 if (lbn >= UFS_NDADDR) 1835 bqrelse(ibp); 1836 continue; 1837 } 1838 /* 1839 * If this is a full size block, we will just grab it 1840 * and assign it to the snapshot inode. Otherwise we 1841 * will proceed to copy it. See explanation for this 1842 * routine as to why only a single snapshot needs to 1843 * claim this block. 1844 */ 1845 if (size == fs->fs_bsize) { 1846 #ifdef DEBUG 1847 if (snapdebug) 1848 printf("%s %ju lbn %jd from inum %ju\n", 1849 "Grabonremove: snapino", 1850 (uintmax_t)ip->i_number, 1851 (intmax_t)lbn, (uintmax_t)inum); 1852 #endif 1853 /* 1854 * If journaling is tracking this write we must add 1855 * the work to the inode or indirect being written. 1856 */ 1857 if (wkhd != NULL) { 1858 if (lbn < UFS_NDADDR) 1859 softdep_inode_append(ip, 1860 curthread->td_ucred, wkhd); 1861 else 1862 softdep_buf_append(ibp, wkhd); 1863 } 1864 if (lbn < UFS_NDADDR) { 1865 DIP_SET(ip, i_db[lbn], bno); 1866 } else if (I_IS_UFS1(ip)) { 1867 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] = bno; 1868 bdwrite(ibp); 1869 } else { 1870 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = bno; 1871 bdwrite(ibp); 1872 } 1873 DIP_SET(ip, i_blocks, DIP(ip, i_blocks) + btodb(size)); 1874 ip->i_flag |= IN_CHANGE | IN_UPDATE; 1875 lockmgr(vp->v_vnlock, LK_RELEASE, NULL); 1876 return (1); 1877 } 1878 if (lbn >= UFS_NDADDR) 1879 bqrelse(ibp); 1880 /* 1881 * Allocate the block into which to do the copy. Note that this 1882 * allocation will never require any additional allocations for 1883 * the snapshot inode. 1884 */ 1885 td->td_pflags |= TDP_COWINPROGRESS; 1886 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn), 1887 fs->fs_bsize, KERNCRED, 0, &cbp); 1888 td->td_pflags &= ~TDP_COWINPROGRESS; 1889 if (error) 1890 break; 1891 #ifdef DEBUG 1892 if (snapdebug) 1893 printf("%s%ju lbn %jd %s %ju size %ld to blkno %jd\n", 1894 "Copyonremove: snapino ", (uintmax_t)ip->i_number, 1895 (intmax_t)lbn, "for inum", (uintmax_t)inum, size, 1896 (intmax_t)cbp->b_blkno); 1897 #endif 1898 /* 1899 * If we have already read the old block contents, then 1900 * simply copy them to the new block. Note that we need 1901 * to synchronously write snapshots that have not been 1902 * unlinked, and hence will be visible after a crash, 1903 * to ensure their integrity. At a minimum we ensure the 1904 * integrity of the filesystem metadata, but use the 1905 * dopersistence sysctl-setable flag to decide on the 1906 * persistence needed for file content data. 1907 */ 1908 if (savedcbp != NULL) { 1909 bcopy(savedcbp->b_data, cbp->b_data, fs->fs_bsize); 1910 bawrite(cbp); 1911 if ((vtype == VDIR || dopersistence) && 1912 ip->i_effnlink > 0) 1913 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 1914 continue; 1915 } 1916 /* 1917 * Otherwise, read the old block contents into the buffer. 1918 */ 1919 if ((error = readblock(vp, cbp, lbn)) != 0) { 1920 bzero(cbp->b_data, fs->fs_bsize); 1921 bawrite(cbp); 1922 if ((vtype == VDIR || dopersistence) && 1923 ip->i_effnlink > 0) 1924 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 1925 break; 1926 } 1927 savedcbp = cbp; 1928 } 1929 /* 1930 * Note that we need to synchronously write snapshots that 1931 * have not been unlinked, and hence will be visible after 1932 * a crash, to ensure their integrity. At a minimum we 1933 * ensure the integrity of the filesystem metadata, but 1934 * use the dopersistence sysctl-setable flag to decide on 1935 * the persistence needed for file content data. 1936 */ 1937 if (savedcbp) { 1938 vp = savedcbp->b_vp; 1939 bawrite(savedcbp); 1940 if ((vtype == VDIR || dopersistence) && 1941 VTOI(vp)->i_effnlink > 0) 1942 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 1943 } 1944 /* 1945 * If we have been unable to allocate a block in which to do 1946 * the copy, then return non-zero so that the fragment will 1947 * not be freed. Although space will be lost, the snapshot 1948 * will stay consistent. 1949 */ 1950 if (error != 0 && wkhd != NULL) 1951 softdep_freework(wkhd); 1952 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 1953 return (error); 1954 } 1955 1956 /* 1957 * Associate snapshot files when mounting. 1958 */ 1959 void 1960 ffs_snapshot_mount(mp) 1961 struct mount *mp; 1962 { 1963 struct ufsmount *ump = VFSTOUFS(mp); 1964 struct vnode *devvp = ump->um_devvp; 1965 struct fs *fs = ump->um_fs; 1966 struct thread *td = curthread; 1967 struct snapdata *sn; 1968 struct vnode *vp; 1969 struct vnode *lastvp; 1970 struct inode *ip; 1971 struct uio auio; 1972 struct iovec aiov; 1973 void *snapblklist; 1974 char *reason; 1975 daddr_t snaplistsize; 1976 int error, snaploc, loc; 1977 1978 /* 1979 * XXX The following needs to be set before ffs_truncate or 1980 * VOP_READ can be called. 1981 */ 1982 mp->mnt_stat.f_iosize = fs->fs_bsize; 1983 /* 1984 * Process each snapshot listed in the superblock. 1985 */ 1986 vp = NULL; 1987 lastvp = NULL; 1988 sn = NULL; 1989 for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++) { 1990 if (fs->fs_snapinum[snaploc] == 0) 1991 break; 1992 if ((error = ffs_vget(mp, fs->fs_snapinum[snaploc], 1993 LK_EXCLUSIVE, &vp)) != 0){ 1994 printf("ffs_snapshot_mount: vget failed %d\n", error); 1995 continue; 1996 } 1997 ip = VTOI(vp); 1998 if (!IS_SNAPSHOT(ip) || ip->i_size == 1999 lblktosize(fs, howmany(fs->fs_size, fs->fs_frag))) { 2000 if (!IS_SNAPSHOT(ip)) { 2001 reason = "non-snapshot"; 2002 } else { 2003 reason = "old format snapshot"; 2004 (void)ffs_truncate(vp, (off_t)0, 0, NOCRED); 2005 (void)ffs_syncvnode(vp, MNT_WAIT, 0); 2006 } 2007 printf("ffs_snapshot_mount: %s inode %d\n", 2008 reason, fs->fs_snapinum[snaploc]); 2009 vput(vp); 2010 vp = NULL; 2011 for (loc = snaploc + 1; loc < FSMAXSNAP; loc++) { 2012 if (fs->fs_snapinum[loc] == 0) 2013 break; 2014 fs->fs_snapinum[loc - 1] = fs->fs_snapinum[loc]; 2015 } 2016 fs->fs_snapinum[loc - 1] = 0; 2017 snaploc--; 2018 continue; 2019 } 2020 /* 2021 * Acquire a lock on the snapdata structure, creating it if 2022 * necessary. 2023 */ 2024 sn = ffs_snapdata_acquire(devvp); 2025 /* 2026 * Change vnode to use shared snapshot lock instead of the 2027 * original private lock. 2028 */ 2029 vp->v_vnlock = &sn->sn_lock; 2030 lockmgr(&vp->v_lock, LK_RELEASE, NULL); 2031 /* 2032 * Link it onto the active snapshot list. 2033 */ 2034 VI_LOCK(devvp); 2035 if (ip->i_nextsnap.tqe_prev != 0) 2036 panic("ffs_snapshot_mount: %ju already on list", 2037 (uintmax_t)ip->i_number); 2038 else 2039 TAILQ_INSERT_TAIL(&sn->sn_head, ip, i_nextsnap); 2040 vp->v_vflag |= VV_SYSTEM; 2041 VI_UNLOCK(devvp); 2042 VOP_UNLOCK(vp, 0); 2043 lastvp = vp; 2044 } 2045 vp = lastvp; 2046 /* 2047 * No usable snapshots found. 2048 */ 2049 if (sn == NULL || vp == NULL) 2050 return; 2051 /* 2052 * Allocate the space for the block hints list. We always want to 2053 * use the list from the newest snapshot. 2054 */ 2055 auio.uio_iov = &aiov; 2056 auio.uio_iovcnt = 1; 2057 aiov.iov_base = (void *)&snaplistsize; 2058 aiov.iov_len = sizeof(snaplistsize); 2059 auio.uio_resid = aiov.iov_len; 2060 auio.uio_offset = 2061 lblktosize(fs, howmany(fs->fs_size, fs->fs_frag)); 2062 auio.uio_segflg = UIO_SYSSPACE; 2063 auio.uio_rw = UIO_READ; 2064 auio.uio_td = td; 2065 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2066 if ((error = VOP_READ(vp, &auio, IO_UNIT, td->td_ucred)) != 0) { 2067 printf("ffs_snapshot_mount: read_1 failed %d\n", error); 2068 VOP_UNLOCK(vp, 0); 2069 return; 2070 } 2071 snapblklist = malloc(snaplistsize * sizeof(daddr_t), 2072 M_UFSMNT, M_WAITOK); 2073 auio.uio_iovcnt = 1; 2074 aiov.iov_base = snapblklist; 2075 aiov.iov_len = snaplistsize * sizeof (daddr_t); 2076 auio.uio_resid = aiov.iov_len; 2077 auio.uio_offset -= sizeof(snaplistsize); 2078 if ((error = VOP_READ(vp, &auio, IO_UNIT, td->td_ucred)) != 0) { 2079 printf("ffs_snapshot_mount: read_2 failed %d\n", error); 2080 VOP_UNLOCK(vp, 0); 2081 free(snapblklist, M_UFSMNT); 2082 return; 2083 } 2084 VOP_UNLOCK(vp, 0); 2085 VI_LOCK(devvp); 2086 ASSERT_VOP_LOCKED(devvp, "ffs_snapshot_mount"); 2087 sn->sn_listsize = snaplistsize; 2088 sn->sn_blklist = (daddr_t *)snapblklist; 2089 devvp->v_vflag |= VV_COPYONWRITE; 2090 VI_UNLOCK(devvp); 2091 } 2092 2093 /* 2094 * Disassociate snapshot files when unmounting. 2095 */ 2096 void 2097 ffs_snapshot_unmount(mp) 2098 struct mount *mp; 2099 { 2100 struct vnode *devvp = VFSTOUFS(mp)->um_devvp; 2101 struct snapdata *sn; 2102 struct inode *xp; 2103 struct vnode *vp; 2104 2105 VI_LOCK(devvp); 2106 sn = devvp->v_rdev->si_snapdata; 2107 while (sn != NULL && (xp = TAILQ_FIRST(&sn->sn_head)) != NULL) { 2108 vp = ITOV(xp); 2109 TAILQ_REMOVE(&sn->sn_head, xp, i_nextsnap); 2110 xp->i_nextsnap.tqe_prev = 0; 2111 lockmgr(&sn->sn_lock, LK_INTERLOCK | LK_EXCLUSIVE, 2112 VI_MTX(devvp)); 2113 lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL); 2114 KASSERT(vp->v_vnlock == &sn->sn_lock, 2115 ("ffs_snapshot_unmount: lost lock mutation")); 2116 vp->v_vnlock = &vp->v_lock; 2117 lockmgr(&vp->v_lock, LK_RELEASE, NULL); 2118 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 2119 if (xp->i_effnlink > 0) 2120 vrele(vp); 2121 VI_LOCK(devvp); 2122 sn = devvp->v_rdev->si_snapdata; 2123 } 2124 try_free_snapdata(devvp); 2125 ASSERT_VOP_LOCKED(devvp, "ffs_snapshot_unmount"); 2126 } 2127 2128 /* 2129 * Check the buffer block to be belong to device buffer that shall be 2130 * locked after snaplk. devvp shall be locked on entry, and will be 2131 * leaved locked upon exit. 2132 */ 2133 static int 2134 ffs_bp_snapblk(devvp, bp) 2135 struct vnode *devvp; 2136 struct buf *bp; 2137 { 2138 struct snapdata *sn; 2139 struct fs *fs; 2140 ufs2_daddr_t lbn, *snapblklist; 2141 int lower, upper, mid; 2142 2143 ASSERT_VI_LOCKED(devvp, "ffs_bp_snapblk"); 2144 KASSERT(devvp->v_type == VCHR, ("Not a device %p", devvp)); 2145 sn = devvp->v_rdev->si_snapdata; 2146 if (sn == NULL || TAILQ_FIRST(&sn->sn_head) == NULL) 2147 return (0); 2148 fs = ITOFS(TAILQ_FIRST(&sn->sn_head)); 2149 lbn = fragstoblks(fs, dbtofsb(fs, bp->b_blkno)); 2150 snapblklist = sn->sn_blklist; 2151 upper = sn->sn_listsize - 1; 2152 lower = 1; 2153 while (lower <= upper) { 2154 mid = (lower + upper) / 2; 2155 if (snapblklist[mid] == lbn) 2156 break; 2157 if (snapblklist[mid] < lbn) 2158 lower = mid + 1; 2159 else 2160 upper = mid - 1; 2161 } 2162 if (lower <= upper) 2163 return (1); 2164 return (0); 2165 } 2166 2167 void 2168 ffs_bdflush(bo, bp) 2169 struct bufobj *bo; 2170 struct buf *bp; 2171 { 2172 struct thread *td; 2173 struct vnode *vp, *devvp; 2174 struct buf *nbp; 2175 int bp_bdskip; 2176 2177 if (bo->bo_dirty.bv_cnt <= dirtybufthresh) 2178 return; 2179 2180 td = curthread; 2181 vp = bp->b_vp; 2182 devvp = bo2vnode(bo); 2183 KASSERT(vp == devvp, ("devvp != vp %p %p", bo, bp)); 2184 2185 VI_LOCK(devvp); 2186 bp_bdskip = ffs_bp_snapblk(devvp, bp); 2187 if (bp_bdskip) 2188 bdwriteskip++; 2189 VI_UNLOCK(devvp); 2190 if (bo->bo_dirty.bv_cnt > dirtybufthresh + 10 && !bp_bdskip) { 2191 (void) VOP_FSYNC(vp, MNT_NOWAIT, td); 2192 altbufferflushes++; 2193 } else { 2194 BO_LOCK(bo); 2195 /* 2196 * Try to find a buffer to flush. 2197 */ 2198 TAILQ_FOREACH(nbp, &bo->bo_dirty.bv_hd, b_bobufs) { 2199 if ((nbp->b_vflags & BV_BKGRDINPROG) || 2200 BUF_LOCK(nbp, 2201 LK_EXCLUSIVE | LK_NOWAIT, NULL)) 2202 continue; 2203 if (bp == nbp) 2204 panic("bdwrite: found ourselves"); 2205 BO_UNLOCK(bo); 2206 /* 2207 * Don't countdeps with the bo lock 2208 * held. 2209 */ 2210 if (buf_countdeps(nbp, 0)) { 2211 BO_LOCK(bo); 2212 BUF_UNLOCK(nbp); 2213 continue; 2214 } 2215 if (bp_bdskip) { 2216 VI_LOCK(devvp); 2217 if (!ffs_bp_snapblk(vp, nbp)) { 2218 VI_UNLOCK(devvp); 2219 BO_LOCK(bo); 2220 BUF_UNLOCK(nbp); 2221 continue; 2222 } 2223 VI_UNLOCK(devvp); 2224 } 2225 if (nbp->b_flags & B_CLUSTEROK) { 2226 vfs_bio_awrite(nbp); 2227 } else { 2228 bremfree(nbp); 2229 bawrite(nbp); 2230 } 2231 dirtybufferflushes++; 2232 break; 2233 } 2234 if (nbp == NULL) 2235 BO_UNLOCK(bo); 2236 } 2237 } 2238 2239 /* 2240 * Check for need to copy block that is about to be written, 2241 * copying the block if necessary. 2242 */ 2243 int 2244 ffs_copyonwrite(devvp, bp) 2245 struct vnode *devvp; 2246 struct buf *bp; 2247 { 2248 struct snapdata *sn; 2249 struct buf *ibp, *cbp, *savedcbp = NULL; 2250 struct thread *td = curthread; 2251 struct fs *fs; 2252 struct inode *ip; 2253 struct vnode *vp = NULL; 2254 ufs2_daddr_t lbn, blkno, *snapblklist; 2255 int lower, upper, mid, indiroff, error = 0; 2256 int launched_async_io, prev_norunningbuf; 2257 long saved_runningbufspace; 2258 2259 if (devvp != bp->b_vp && IS_SNAPSHOT(VTOI(bp->b_vp))) 2260 return (0); /* Update on a snapshot file */ 2261 if (td->td_pflags & TDP_COWINPROGRESS) 2262 panic("ffs_copyonwrite: recursive call"); 2263 /* 2264 * First check to see if it is in the preallocated list. 2265 * By doing this check we avoid several potential deadlocks. 2266 */ 2267 VI_LOCK(devvp); 2268 sn = devvp->v_rdev->si_snapdata; 2269 if (sn == NULL || 2270 TAILQ_EMPTY(&sn->sn_head)) { 2271 VI_UNLOCK(devvp); 2272 return (0); /* No snapshot */ 2273 } 2274 ip = TAILQ_FIRST(&sn->sn_head); 2275 fs = ITOFS(ip); 2276 lbn = fragstoblks(fs, dbtofsb(fs, bp->b_blkno)); 2277 snapblklist = sn->sn_blklist; 2278 upper = sn->sn_listsize - 1; 2279 lower = 1; 2280 while (lower <= upper) { 2281 mid = (lower + upper) / 2; 2282 if (snapblklist[mid] == lbn) 2283 break; 2284 if (snapblklist[mid] < lbn) 2285 lower = mid + 1; 2286 else 2287 upper = mid - 1; 2288 } 2289 if (lower <= upper) { 2290 VI_UNLOCK(devvp); 2291 return (0); 2292 } 2293 launched_async_io = 0; 2294 prev_norunningbuf = td->td_pflags & TDP_NORUNNINGBUF; 2295 /* 2296 * Since I/O on bp isn't yet in progress and it may be blocked 2297 * for a long time waiting on snaplk, back it out of 2298 * runningbufspace, possibly waking other threads waiting for space. 2299 */ 2300 saved_runningbufspace = bp->b_runningbufspace; 2301 if (saved_runningbufspace != 0) 2302 runningbufwakeup(bp); 2303 /* 2304 * Not in the precomputed list, so check the snapshots. 2305 */ 2306 while (lockmgr(&sn->sn_lock, LK_INTERLOCK | LK_EXCLUSIVE | LK_SLEEPFAIL, 2307 VI_MTX(devvp)) != 0) { 2308 VI_LOCK(devvp); 2309 sn = devvp->v_rdev->si_snapdata; 2310 if (sn == NULL || 2311 TAILQ_EMPTY(&sn->sn_head)) { 2312 VI_UNLOCK(devvp); 2313 if (saved_runningbufspace != 0) { 2314 bp->b_runningbufspace = saved_runningbufspace; 2315 atomic_add_long(&runningbufspace, 2316 bp->b_runningbufspace); 2317 } 2318 return (0); /* Snapshot gone */ 2319 } 2320 } 2321 TAILQ_FOREACH(ip, &sn->sn_head, i_nextsnap) { 2322 vp = ITOV(ip); 2323 if (DOINGSOFTDEP(vp)) 2324 softdep_prealloc(vp, MNT_WAIT); 2325 /* 2326 * We ensure that everything of our own that needs to be 2327 * copied will be done at the time that ffs_snapshot is 2328 * called. Thus we can skip the check here which can 2329 * deadlock in doing the lookup in UFS_BALLOC. 2330 */ 2331 if (bp->b_vp == vp) 2332 continue; 2333 /* 2334 * Check to see if block needs to be copied. We do not have 2335 * to hold the snapshot lock while doing this lookup as it 2336 * will never require any additional allocations for the 2337 * snapshot inode. 2338 */ 2339 if (lbn < UFS_NDADDR) { 2340 blkno = DIP(ip, i_db[lbn]); 2341 } else { 2342 td->td_pflags |= TDP_COWINPROGRESS | TDP_NORUNNINGBUF; 2343 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn), 2344 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 2345 td->td_pflags &= ~TDP_COWINPROGRESS; 2346 if (error) 2347 break; 2348 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs); 2349 if (I_IS_UFS1(ip)) 2350 blkno=((ufs1_daddr_t *)(ibp->b_data))[indiroff]; 2351 else 2352 blkno=((ufs2_daddr_t *)(ibp->b_data))[indiroff]; 2353 bqrelse(ibp); 2354 } 2355 #ifdef INVARIANTS 2356 if (blkno == BLK_SNAP && bp->b_lblkno >= 0) 2357 panic("ffs_copyonwrite: bad copy block"); 2358 #endif 2359 if (blkno != 0) 2360 continue; 2361 /* 2362 * Allocate the block into which to do the copy. Since 2363 * multiple processes may all try to copy the same block, 2364 * we have to recheck our need to do a copy if we sleep 2365 * waiting for the lock. 2366 * 2367 * Because all snapshots on a filesystem share a single 2368 * lock, we ensure that we will never be in competition 2369 * with another process to allocate a block. 2370 */ 2371 td->td_pflags |= TDP_COWINPROGRESS | TDP_NORUNNINGBUF; 2372 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn), 2373 fs->fs_bsize, KERNCRED, 0, &cbp); 2374 td->td_pflags &= ~TDP_COWINPROGRESS; 2375 if (error) 2376 break; 2377 #ifdef DEBUG 2378 if (snapdebug) { 2379 printf("Copyonwrite: snapino %ju lbn %jd for ", 2380 (uintmax_t)ip->i_number, (intmax_t)lbn); 2381 if (bp->b_vp == devvp) 2382 printf("fs metadata"); 2383 else 2384 printf("inum %ju", 2385 (uintmax_t)VTOI(bp->b_vp)->i_number); 2386 printf(" lblkno %jd to blkno %jd\n", 2387 (intmax_t)bp->b_lblkno, (intmax_t)cbp->b_blkno); 2388 } 2389 #endif 2390 /* 2391 * If we have already read the old block contents, then 2392 * simply copy them to the new block. Note that we need 2393 * to synchronously write snapshots that have not been 2394 * unlinked, and hence will be visible after a crash, 2395 * to ensure their integrity. At a minimum we ensure the 2396 * integrity of the filesystem metadata, but use the 2397 * dopersistence sysctl-setable flag to decide on the 2398 * persistence needed for file content data. 2399 */ 2400 if (savedcbp != NULL) { 2401 bcopy(savedcbp->b_data, cbp->b_data, fs->fs_bsize); 2402 bawrite(cbp); 2403 if ((devvp == bp->b_vp || bp->b_vp->v_type == VDIR || 2404 dopersistence) && ip->i_effnlink > 0) 2405 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 2406 else 2407 launched_async_io = 1; 2408 continue; 2409 } 2410 /* 2411 * Otherwise, read the old block contents into the buffer. 2412 */ 2413 if ((error = readblock(vp, cbp, lbn)) != 0) { 2414 bzero(cbp->b_data, fs->fs_bsize); 2415 bawrite(cbp); 2416 if ((devvp == bp->b_vp || bp->b_vp->v_type == VDIR || 2417 dopersistence) && ip->i_effnlink > 0) 2418 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 2419 else 2420 launched_async_io = 1; 2421 break; 2422 } 2423 savedcbp = cbp; 2424 } 2425 /* 2426 * Note that we need to synchronously write snapshots that 2427 * have not been unlinked, and hence will be visible after 2428 * a crash, to ensure their integrity. At a minimum we 2429 * ensure the integrity of the filesystem metadata, but 2430 * use the dopersistence sysctl-setable flag to decide on 2431 * the persistence needed for file content data. 2432 */ 2433 if (savedcbp) { 2434 vp = savedcbp->b_vp; 2435 bawrite(savedcbp); 2436 if ((devvp == bp->b_vp || bp->b_vp->v_type == VDIR || 2437 dopersistence) && VTOI(vp)->i_effnlink > 0) 2438 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 2439 else 2440 launched_async_io = 1; 2441 } 2442 lockmgr(vp->v_vnlock, LK_RELEASE, NULL); 2443 td->td_pflags = (td->td_pflags & ~TDP_NORUNNINGBUF) | 2444 prev_norunningbuf; 2445 if (launched_async_io && (td->td_pflags & TDP_NORUNNINGBUF) == 0) 2446 waitrunningbufspace(); 2447 /* 2448 * I/O on bp will now be started, so count it in runningbufspace. 2449 */ 2450 if (saved_runningbufspace != 0) { 2451 bp->b_runningbufspace = saved_runningbufspace; 2452 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 2453 } 2454 return (error); 2455 } 2456 2457 /* 2458 * sync snapshots to force freework records waiting on snapshots to claim 2459 * blocks to free. 2460 */ 2461 void 2462 ffs_sync_snap(mp, waitfor) 2463 struct mount *mp; 2464 int waitfor; 2465 { 2466 struct snapdata *sn; 2467 struct vnode *devvp; 2468 struct vnode *vp; 2469 struct inode *ip; 2470 2471 devvp = VFSTOUFS(mp)->um_devvp; 2472 if ((devvp->v_vflag & VV_COPYONWRITE) == 0) 2473 return; 2474 for (;;) { 2475 VI_LOCK(devvp); 2476 sn = devvp->v_rdev->si_snapdata; 2477 if (sn == NULL) { 2478 VI_UNLOCK(devvp); 2479 return; 2480 } 2481 if (lockmgr(&sn->sn_lock, 2482 LK_INTERLOCK | LK_EXCLUSIVE | LK_SLEEPFAIL, 2483 VI_MTX(devvp)) == 0) 2484 break; 2485 } 2486 TAILQ_FOREACH(ip, &sn->sn_head, i_nextsnap) { 2487 vp = ITOV(ip); 2488 ffs_syncvnode(vp, waitfor, NO_INO_UPDT); 2489 } 2490 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 2491 } 2492 2493 /* 2494 * Read the specified block into the given buffer. 2495 * Much of this boiler-plate comes from bwrite(). 2496 */ 2497 static int 2498 readblock(vp, bp, lbn) 2499 struct vnode *vp; 2500 struct buf *bp; 2501 ufs2_daddr_t lbn; 2502 { 2503 struct inode *ip = VTOI(vp); 2504 struct bio *bip; 2505 struct fs *fs; 2506 2507 ip = VTOI(vp); 2508 fs = ITOFS(ip); 2509 2510 bip = g_alloc_bio(); 2511 bip->bio_cmd = BIO_READ; 2512 bip->bio_offset = dbtob(fsbtodb(fs, blkstofrags(fs, lbn))); 2513 bip->bio_data = bp->b_data; 2514 bip->bio_length = bp->b_bcount; 2515 bip->bio_done = NULL; 2516 2517 g_io_request(bip, ITODEVVP(ip)->v_bufobj.bo_private); 2518 bp->b_error = biowait(bip, "snaprdb"); 2519 g_destroy_bio(bip); 2520 return (bp->b_error); 2521 } 2522 2523 #endif 2524 2525 /* 2526 * Process file deletes that were deferred by ufs_inactive() due to 2527 * the file system being suspended. Transfer IN_LAZYACCESS into 2528 * IN_MODIFIED for vnodes that were accessed during suspension. 2529 */ 2530 void 2531 process_deferred_inactive(struct mount *mp) 2532 { 2533 struct vnode *vp, *mvp; 2534 struct inode *ip; 2535 struct thread *td; 2536 int error; 2537 2538 td = curthread; 2539 (void) vn_start_secondary_write(NULL, &mp, V_WAIT); 2540 loop: 2541 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 2542 /* 2543 * IN_LAZYACCESS is checked here without holding any 2544 * vnode lock, but this flag is set only while holding 2545 * vnode interlock. 2546 */ 2547 if (vp->v_type == VNON || 2548 ((VTOI(vp)->i_flag & IN_LAZYACCESS) == 0 && 2549 ((vp->v_iflag & VI_OWEINACT) == 0 || vp->v_usecount > 0))) { 2550 VI_UNLOCK(vp); 2551 continue; 2552 } 2553 vholdl(vp); 2554 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 2555 if (error != 0) { 2556 vdrop(vp); 2557 if (error == ENOENT) 2558 continue; /* vnode recycled */ 2559 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 2560 goto loop; 2561 } 2562 ip = VTOI(vp); 2563 if ((ip->i_flag & IN_LAZYACCESS) != 0) { 2564 ip->i_flag &= ~IN_LAZYACCESS; 2565 ip->i_flag |= IN_MODIFIED; 2566 } 2567 VI_LOCK(vp); 2568 if ((vp->v_iflag & VI_OWEINACT) == 0 || vp->v_usecount > 0) { 2569 VI_UNLOCK(vp); 2570 VOP_UNLOCK(vp, 0); 2571 vdrop(vp); 2572 continue; 2573 } 2574 vinactive(vp, td); 2575 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, 2576 ("process_deferred_inactive: got VI_OWEINACT")); 2577 VI_UNLOCK(vp); 2578 VOP_UNLOCK(vp, 0); 2579 vdrop(vp); 2580 } 2581 vn_finished_secondary_write(mp); 2582 } 2583 2584 #ifndef NO_FFS_SNAPSHOT 2585 2586 static struct snapdata * 2587 ffs_snapdata_alloc(void) 2588 { 2589 struct snapdata *sn; 2590 2591 /* 2592 * Fetch a snapdata from the free list if there is one available. 2593 */ 2594 mtx_lock(&snapfree_lock); 2595 sn = LIST_FIRST(&snapfree); 2596 if (sn != NULL) 2597 LIST_REMOVE(sn, sn_link); 2598 mtx_unlock(&snapfree_lock); 2599 if (sn != NULL) 2600 return (sn); 2601 /* 2602 * If there were no free snapdatas allocate one. 2603 */ 2604 sn = malloc(sizeof *sn, M_UFSMNT, M_WAITOK | M_ZERO); 2605 TAILQ_INIT(&sn->sn_head); 2606 lockinit(&sn->sn_lock, PVFS, "snaplk", VLKTIMEOUT, 2607 LK_CANRECURSE | LK_NOSHARE); 2608 return (sn); 2609 } 2610 2611 /* 2612 * The snapdata is never freed because we can not be certain that 2613 * there are no threads sleeping on the snap lock. Persisting 2614 * them permanently avoids costly synchronization in ffs_lock(). 2615 */ 2616 static void 2617 ffs_snapdata_free(struct snapdata *sn) 2618 { 2619 mtx_lock(&snapfree_lock); 2620 LIST_INSERT_HEAD(&snapfree, sn, sn_link); 2621 mtx_unlock(&snapfree_lock); 2622 } 2623 2624 /* Try to free snapdata associated with devvp */ 2625 static void 2626 try_free_snapdata(struct vnode *devvp) 2627 { 2628 struct snapdata *sn; 2629 ufs2_daddr_t *snapblklist; 2630 2631 ASSERT_VI_LOCKED(devvp, "try_free_snapdata"); 2632 sn = devvp->v_rdev->si_snapdata; 2633 2634 if (sn == NULL || TAILQ_FIRST(&sn->sn_head) != NULL || 2635 (devvp->v_vflag & VV_COPYONWRITE) == 0) { 2636 VI_UNLOCK(devvp); 2637 return; 2638 } 2639 2640 devvp->v_rdev->si_snapdata = NULL; 2641 devvp->v_vflag &= ~VV_COPYONWRITE; 2642 lockmgr(&sn->sn_lock, LK_DRAIN|LK_INTERLOCK, VI_MTX(devvp)); 2643 snapblklist = sn->sn_blklist; 2644 sn->sn_blklist = NULL; 2645 sn->sn_listsize = 0; 2646 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 2647 if (snapblklist != NULL) 2648 free(snapblklist, M_UFSMNT); 2649 ffs_snapdata_free(sn); 2650 } 2651 2652 static struct snapdata * 2653 ffs_snapdata_acquire(struct vnode *devvp) 2654 { 2655 struct snapdata *nsn, *sn; 2656 int error; 2657 2658 /* 2659 * Allocate a free snapdata. This is done before acquiring the 2660 * devvp lock to avoid allocation while the devvp interlock is 2661 * held. 2662 */ 2663 nsn = ffs_snapdata_alloc(); 2664 2665 for (;;) { 2666 VI_LOCK(devvp); 2667 sn = devvp->v_rdev->si_snapdata; 2668 if (sn == NULL) { 2669 /* 2670 * This is the first snapshot on this 2671 * filesystem and we use our pre-allocated 2672 * snapdata. Publish sn with the sn_lock 2673 * owned by us, to avoid the race. 2674 */ 2675 error = lockmgr(&nsn->sn_lock, LK_EXCLUSIVE | 2676 LK_NOWAIT, NULL); 2677 if (error != 0) 2678 panic("leaked sn, lockmgr error %d", error); 2679 sn = devvp->v_rdev->si_snapdata = nsn; 2680 VI_UNLOCK(devvp); 2681 nsn = NULL; 2682 break; 2683 } 2684 2685 /* 2686 * There is a snapshots which already exists on this 2687 * filesystem, grab a reference to the common lock. 2688 */ 2689 error = lockmgr(&sn->sn_lock, LK_INTERLOCK | 2690 LK_EXCLUSIVE | LK_SLEEPFAIL, VI_MTX(devvp)); 2691 if (error == 0) 2692 break; 2693 } 2694 2695 /* 2696 * Free any unused snapdata. 2697 */ 2698 if (nsn != NULL) 2699 ffs_snapdata_free(nsn); 2700 2701 return (sn); 2702 } 2703 2704 #endif 2705