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/gsb_crc32.h> 48 #include <sys/bio.h> 49 #include <sys/buf.h> 50 #include <sys/fcntl.h> 51 #include <sys/proc.h> 52 #include <sys/namei.h> 53 #include <sys/sched.h> 54 #include <sys/stat.h> 55 #include <sys/malloc.h> 56 #include <sys/mount.h> 57 #include <sys/resource.h> 58 #include <sys/resourcevar.h> 59 #include <sys/rwlock.h> 60 #include <sys/vnode.h> 61 62 #include <geom/geom.h> 63 64 #include <ufs/ufs/extattr.h> 65 #include <ufs/ufs/quota.h> 66 #include <ufs/ufs/ufsmount.h> 67 #include <ufs/ufs/inode.h> 68 #include <ufs/ufs/ufs_extern.h> 69 70 #include <ufs/ffs/fs.h> 71 #include <ufs/ffs/ffs_extern.h> 72 73 #define KERNCRED thread0.td_ucred 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 DIAGNOSTIC 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 /* DIAGNOSTIC */ 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 char saved_nice = 0; 212 long redo = 0, snaplistsize = 0; 213 int32_t *lp; 214 void *space; 215 struct fs *copy_fs = NULL, *fs; 216 struct thread *td = curthread; 217 struct inode *ip, *xp; 218 struct buf *bp, *nbp, *ibp; 219 struct nameidata nd; 220 struct mount *wrtmp; 221 struct vattr vat; 222 struct vnode *vp, *xvp, *mvp, *devvp; 223 struct uio auio; 224 struct iovec aiov; 225 struct snapdata *sn; 226 struct ufsmount *ump; 227 #ifdef DIAGNOSTIC 228 struct timespec starttime = {0, 0}, endtime; 229 #endif 230 231 ump = VFSTOUFS(mp); 232 fs = ump->um_fs; 233 sn = NULL; 234 /* 235 * At the moment, journaled soft updates cannot support 236 * taking snapshots. 237 */ 238 if (MOUNTEDSUJ(mp)) { 239 vfs_mount_error(mp, "%s: Snapshots are not yet supported when " 240 "running with journaled soft updates", fs->fs_fsmnt); 241 return (EOPNOTSUPP); 242 } 243 MNT_ILOCK(mp); 244 flag = mp->mnt_flag; 245 MNT_IUNLOCK(mp); 246 /* 247 * Need to serialize access to snapshot code per filesystem. 248 */ 249 /* 250 * Assign a snapshot slot in the superblock. 251 */ 252 UFS_LOCK(ump); 253 for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++) 254 if (fs->fs_snapinum[snaploc] == 0) 255 break; 256 UFS_UNLOCK(ump); 257 if (snaploc == FSMAXSNAP) 258 return (ENOSPC); 259 /* 260 * Create the snapshot file. 261 */ 262 restart: 263 NDINIT(&nd, CREATE, LOCKPARENT | LOCKLEAF | NOCACHE, UIO_SYSSPACE, 264 snapfile, td); 265 if ((error = namei(&nd)) != 0) 266 return (error); 267 if (nd.ni_vp != NULL) { 268 vput(nd.ni_vp); 269 error = EEXIST; 270 } 271 if (nd.ni_dvp->v_mount != mp) 272 error = EXDEV; 273 if (error) { 274 NDFREE(&nd, NDF_ONLY_PNBUF); 275 if (nd.ni_dvp == nd.ni_vp) 276 vrele(nd.ni_dvp); 277 else 278 vput(nd.ni_dvp); 279 return (error); 280 } 281 VATTR_NULL(&vat); 282 vat.va_type = VREG; 283 vat.va_mode = S_IRUSR; 284 vat.va_vaflags |= VA_EXCLUSIVE; 285 if (VOP_GETWRITEMOUNT(nd.ni_dvp, &wrtmp)) 286 wrtmp = NULL; 287 if (wrtmp != mp) 288 panic("ffs_snapshot: mount mismatch"); 289 vfs_rel(wrtmp); 290 if (vn_start_write(NULL, &wrtmp, V_NOWAIT) != 0) { 291 NDFREE(&nd, NDF_ONLY_PNBUF); 292 vput(nd.ni_dvp); 293 if ((error = vn_start_write(NULL, &wrtmp, 294 V_XSLEEP | PCATCH)) != 0) 295 return (error); 296 goto restart; 297 } 298 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vat); 299 if (error) { 300 VOP_VPUT_PAIR(nd.ni_dvp, NULL, true); 301 NDFREE(&nd, NDF_ONLY_PNBUF); 302 vn_finished_write(wrtmp); 303 if (error == ERELOOKUP) 304 goto restart; 305 return (error); 306 } 307 vp = nd.ni_vp; 308 vref(nd.ni_dvp); 309 VOP_VPUT_PAIR(nd.ni_dvp, &vp, false); 310 if (VN_IS_DOOMED(vp)) { 311 error = EBADF; 312 goto out; 313 } 314 vnode_create_vobject(nd.ni_vp, fs->fs_size, td); 315 vp->v_vflag |= VV_SYSTEM; 316 ip = VTOI(vp); 317 devvp = ITODEVVP(ip); 318 /* 319 * Calculate the size of the filesystem then allocate the block 320 * immediately following the last block of the filesystem that 321 * will contain the snapshot list. This operation allows us to 322 * set the size of the snapshot. 323 */ 324 numblks = howmany(fs->fs_size, fs->fs_frag); 325 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)numblks), 326 fs->fs_bsize, KERNCRED, BA_CLRBUF, &bp); 327 if (error) 328 goto out; 329 bawrite(bp); 330 ip->i_size = lblktosize(fs, (off_t)(numblks + 1)); 331 DIP_SET(ip, i_size, ip->i_size); 332 UFS_INODE_SET_FLAG(ip, IN_SIZEMOD | IN_CHANGE | IN_UPDATE); 333 /* 334 * Preallocate critical data structures so that we can copy 335 * them in without further allocation after we suspend all 336 * operations on the filesystem. We would like to just release 337 * the allocated buffers without writing them since they will 338 * be filled in below once we are ready to go, but this upsets 339 * the soft update code, so we go ahead and write the new buffers. 340 * 341 * Allocate all indirect blocks and mark all of them as not 342 * needing to be copied. 343 */ 344 for (blkno = UFS_NDADDR; blkno < numblks; blkno += NINDIR(fs)) { 345 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)blkno), 346 fs->fs_bsize, td->td_ucred, BA_METAONLY, &ibp); 347 if (error) 348 goto out; 349 bawrite(ibp); 350 } 351 /* 352 * Allocate copies for the superblock and its summary information. 353 */ 354 error = UFS_BALLOC(vp, fs->fs_sblockloc, fs->fs_sbsize, KERNCRED, 355 0, &nbp); 356 if (error) 357 goto out; 358 bawrite(nbp); 359 blkno = fragstoblks(fs, fs->fs_csaddr); 360 len = howmany(fs->fs_cssize, fs->fs_bsize); 361 for (loc = 0; loc < len; loc++) { 362 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(blkno + loc)), 363 fs->fs_bsize, KERNCRED, 0, &nbp); 364 if (error) 365 goto out; 366 bawrite(nbp); 367 } 368 /* 369 * Allocate all cylinder group blocks. 370 */ 371 for (cg = 0; cg < fs->fs_ncg; cg++) { 372 error = UFS_BALLOC(vp, lfragtosize(fs, cgtod(fs, cg)), 373 fs->fs_bsize, KERNCRED, 0, &nbp); 374 if (error) 375 goto out; 376 bawrite(nbp); 377 if (cg % 10 == 0) { 378 error = ffs_syncvnode(vp, MNT_WAIT, 0); 379 /* vp possibly reclaimed if unlocked */ 380 if (error != 0) 381 goto out; 382 } 383 } 384 /* 385 * Copy all the cylinder group maps. Although the 386 * filesystem is still active, we hope that only a few 387 * cylinder groups will change between now and when we 388 * suspend operations. Thus, we will be able to quickly 389 * touch up the few cylinder groups that changed during 390 * the suspension period. 391 */ 392 len = roundup2(howmany(fs->fs_ncg, NBBY), sizeof(int)); 393 space = malloc(len, M_DEVBUF, M_WAITOK | M_ZERO); 394 UFS_LOCK(ump); 395 fs->fs_active = space; 396 UFS_UNLOCK(ump); 397 for (cg = 0; cg < fs->fs_ncg; cg++) { 398 error = UFS_BALLOC(vp, lfragtosize(fs, cgtod(fs, cg)), 399 fs->fs_bsize, KERNCRED, 0, &nbp); 400 if (error) 401 goto out; 402 error = cgaccount(cg, vp, nbp, 1); 403 bawrite(nbp); 404 if (cg % 10 == 0 && error == 0) 405 error = ffs_syncvnode(vp, MNT_WAIT, 0); 406 if (error) 407 goto out; 408 } 409 /* 410 * Change inode to snapshot type file. 411 */ 412 ip->i_flags |= SF_SNAPSHOT; 413 DIP_SET(ip, i_flags, ip->i_flags); 414 UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE); 415 /* 416 * Ensure that the snapshot is completely on disk. 417 * Since we have marked it as a snapshot it is safe to 418 * unlock it as no process will be allowed to write to it. 419 */ 420 if ((error = ffs_syncvnode(vp, MNT_WAIT, 0)) != 0) 421 goto out; 422 VOP_UNLOCK(vp); 423 /* 424 * All allocations are done, so we can now snapshot the system. 425 * 426 * Recind nice scheduling while running with the filesystem suspended. 427 */ 428 if (td->td_proc->p_nice > 0) { 429 struct proc *p; 430 431 p = td->td_proc; 432 PROC_LOCK(p); 433 saved_nice = p->p_nice; 434 sched_nice(p, 0); 435 PROC_UNLOCK(p); 436 } 437 /* 438 * Suspend operation on filesystem. 439 */ 440 for (;;) { 441 vn_finished_write(wrtmp); 442 if ((error = vfs_write_suspend(vp->v_mount, 0)) != 0) { 443 vn_start_write(NULL, &wrtmp, V_WAIT); 444 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 445 goto out; 446 } 447 if (mp->mnt_kern_flag & MNTK_SUSPENDED) 448 break; 449 vn_start_write(NULL, &wrtmp, V_WAIT); 450 } 451 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 452 if (ip->i_effnlink == 0) { 453 error = ENOENT; /* Snapshot file unlinked */ 454 goto resumefs; 455 } 456 #ifdef DIAGNOSTIC 457 if (collectsnapstats) 458 nanotime(&starttime); 459 #endif 460 461 /* 462 * First, copy all the cylinder group maps that have changed. 463 */ 464 for (cg = 0; cg < fs->fs_ncg; cg++) { 465 if ((ACTIVECGNUM(fs, cg) & ACTIVECGOFF(cg)) != 0) 466 continue; 467 redo++; 468 error = UFS_BALLOC(vp, lfragtosize(fs, cgtod(fs, cg)), 469 fs->fs_bsize, KERNCRED, 0, &nbp); 470 if (error) 471 goto resumefs; 472 error = cgaccount(cg, vp, nbp, 2); 473 bawrite(nbp); 474 if (error) 475 goto resumefs; 476 } 477 /* 478 * Grab a copy of the superblock and its summary information. 479 * We delay writing it until the suspension is released below. 480 */ 481 copy_fs = malloc((u_long)fs->fs_bsize, M_UFSMNT, M_WAITOK); 482 bcopy(fs, copy_fs, fs->fs_sbsize); 483 copy_fs->fs_si = malloc(sizeof(struct fs_summary_info), M_UFSMNT, 484 M_ZERO | M_WAITOK); 485 if ((fs->fs_flags & (FS_UNCLEAN | FS_NEEDSFSCK)) == 0) 486 copy_fs->fs_clean = 1; 487 size = fs->fs_bsize < SBLOCKSIZE ? fs->fs_bsize : SBLOCKSIZE; 488 if (fs->fs_sbsize < size) 489 bzero(&((char *)copy_fs)[fs->fs_sbsize], 490 size - fs->fs_sbsize); 491 size = blkroundup(fs, fs->fs_cssize); 492 if (fs->fs_contigsumsize > 0) 493 size += fs->fs_ncg * sizeof(int32_t); 494 space = malloc((u_long)size, M_UFSMNT, M_WAITOK); 495 copy_fs->fs_csp = space; 496 bcopy(fs->fs_csp, copy_fs->fs_csp, fs->fs_cssize); 497 space = (char *)space + fs->fs_cssize; 498 loc = howmany(fs->fs_cssize, fs->fs_fsize); 499 i = fs->fs_frag - loc % fs->fs_frag; 500 len = (i == fs->fs_frag) ? 0 : i * fs->fs_fsize; 501 if (len > 0) { 502 if ((error = bread(devvp, fsbtodb(fs, fs->fs_csaddr + loc), 503 len, KERNCRED, &bp)) != 0) { 504 brelse(bp); 505 goto resumefs; 506 } 507 bcopy(bp->b_data, space, (u_int)len); 508 space = (char *)space + len; 509 bp->b_flags |= B_INVAL | B_NOCACHE; 510 brelse(bp); 511 } 512 if (fs->fs_contigsumsize > 0) { 513 copy_fs->fs_maxcluster = lp = space; 514 for (i = 0; i < fs->fs_ncg; i++) 515 *lp++ = fs->fs_contigsumsize; 516 } 517 /* 518 * We must check for active files that have been unlinked 519 * (e.g., with a zero link count). We have to expunge all 520 * trace of these files from the snapshot so that they are 521 * not reclaimed prematurely by fsck or unnecessarily dumped. 522 * We turn off the MNTK_SUSPENDED flag to avoid a panic from 523 * spec_strategy about writing on a suspended filesystem. 524 * Note that we skip unlinked snapshot files as they will 525 * be handled separately below. 526 * 527 * We also calculate the size needed for the snapshot list. 528 * Initial number of entries is composed of: 529 * - one for each cylinder group map 530 * - one for each block used by superblock summary table 531 * - one for each snapshot inode block 532 * - one for the superblock 533 * - one for the snapshot list 534 * The direct block entries in the snapshot are always 535 * copied (see reason below). Note that the superblock and 536 * the first cylinder group will almost always be allocated 537 * in the direct blocks, but we add the slop for them in case 538 * they do not end up there. The snapshot list size may get 539 * expanded by one because of an update of an inode block for 540 * an unlinked but still open file when it is expunged. 541 * 542 * Because the direct block pointers are always copied, they 543 * are not added to the list. Instead ffs_copyonwrite() 544 * explicitly checks for them before checking the snapshot list. 545 */ 546 snaplistsize = fs->fs_ncg + howmany(fs->fs_cssize, fs->fs_bsize) + 547 FSMAXSNAP + /* superblock */ 1 + /* snaplist */ 1; 548 MNT_ILOCK(mp); 549 mp->mnt_kern_flag &= ~MNTK_SUSPENDED; 550 MNT_IUNLOCK(mp); 551 loop: 552 MNT_VNODE_FOREACH_ALL(xvp, mp, mvp) { 553 if ((xvp->v_usecount == 0 && 554 (xvp->v_iflag & (VI_OWEINACT | VI_DOINGINACT)) == 0) || 555 xvp->v_type == VNON || 556 IS_SNAPSHOT(VTOI(xvp))) { 557 VI_UNLOCK(xvp); 558 continue; 559 } 560 /* 561 * We can skip parent directory vnode because it must have 562 * this snapshot file in it. 563 */ 564 if (xvp == nd.ni_dvp) { 565 VI_UNLOCK(xvp); 566 continue; 567 } 568 vholdl(xvp); 569 if (vn_lock(xvp, LK_EXCLUSIVE | LK_INTERLOCK) != 0) { 570 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 571 vdrop(xvp); 572 goto loop; 573 } 574 VI_LOCK(xvp); 575 if (xvp->v_usecount == 0 && 576 (xvp->v_iflag & (VI_OWEINACT | VI_DOINGINACT)) == 0) { 577 VI_UNLOCK(xvp); 578 VOP_UNLOCK(xvp); 579 vdrop(xvp); 580 continue; 581 } 582 VI_UNLOCK(xvp); 583 #ifdef DIAGNOSTIC 584 if (snapdebug) 585 vn_printf(xvp, "ffs_snapshot: busy vnode "); 586 #endif 587 if (VOP_GETATTR(xvp, &vat, td->td_ucred) == 0 && 588 vat.va_nlink > 0) { 589 VOP_UNLOCK(xvp); 590 vdrop(xvp); 591 continue; 592 } 593 xp = VTOI(xvp); 594 if (ffs_checkfreefile(copy_fs, vp, xp->i_number)) { 595 VOP_UNLOCK(xvp); 596 vdrop(xvp); 597 continue; 598 } 599 /* 600 * If there is a fragment, clear it here. 601 */ 602 blkno = 0; 603 loc = howmany(xp->i_size, fs->fs_bsize) - 1; 604 if (loc < UFS_NDADDR) { 605 len = fragroundup(fs, blkoff(fs, xp->i_size)); 606 if (len != 0 && len < fs->fs_bsize) { 607 ffs_blkfree(ump, copy_fs, vp, 608 DIP(xp, i_db[loc]), len, xp->i_number, 609 xvp->v_type, NULL, SINGLETON_KEY); 610 blkno = DIP(xp, i_db[loc]); 611 DIP_SET(xp, i_db[loc], 0); 612 } 613 } 614 snaplistsize += 1; 615 if (I_IS_UFS1(xp)) 616 error = expunge_ufs1(vp, xp, copy_fs, fullacct_ufs1, 617 BLK_NOCOPY, 1); 618 else 619 error = expunge_ufs2(vp, xp, copy_fs, fullacct_ufs2, 620 BLK_NOCOPY, 1); 621 if (blkno) 622 DIP_SET(xp, i_db[loc], blkno); 623 if (!error) 624 error = ffs_freefile(ump, copy_fs, vp, xp->i_number, 625 xp->i_mode, NULL); 626 VOP_UNLOCK(xvp); 627 vdrop(xvp); 628 if (error) { 629 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 630 goto resumefs; 631 } 632 } 633 /* 634 * Erase the journal file from the snapshot. 635 */ 636 if (fs->fs_flags & FS_SUJ) { 637 error = softdep_journal_lookup(mp, &xvp); 638 if (error) 639 goto resumefs; 640 xp = VTOI(xvp); 641 if (I_IS_UFS1(xp)) 642 error = expunge_ufs1(vp, xp, copy_fs, fullacct_ufs1, 643 BLK_NOCOPY, 0); 644 else 645 error = expunge_ufs2(vp, xp, copy_fs, fullacct_ufs2, 646 BLK_NOCOPY, 0); 647 vput(xvp); 648 } 649 /* 650 * Acquire a lock on the snapdata structure, creating it if necessary. 651 */ 652 sn = ffs_snapdata_acquire(devvp); 653 /* 654 * Change vnode to use shared snapshot lock instead of the original 655 * private lock. 656 */ 657 vp->v_vnlock = &sn->sn_lock; 658 lockmgr(&vp->v_lock, LK_RELEASE, NULL); 659 xp = TAILQ_FIRST(&sn->sn_head); 660 /* 661 * If this is the first snapshot on this filesystem, then we need 662 * to allocate the space for the list of preallocated snapshot blocks. 663 * This list will be refined below, but this preliminary one will 664 * keep us out of deadlock until the full one is ready. 665 */ 666 if (xp == NULL) { 667 snapblklist = malloc(snaplistsize * sizeof(daddr_t), 668 M_UFSMNT, M_WAITOK); 669 blkp = &snapblklist[1]; 670 *blkp++ = lblkno(fs, fs->fs_sblockloc); 671 blkno = fragstoblks(fs, fs->fs_csaddr); 672 for (cg = 0; cg < fs->fs_ncg; cg++) { 673 if (fragstoblks(fs, cgtod(fs, cg) > blkno)) 674 break; 675 *blkp++ = fragstoblks(fs, cgtod(fs, cg)); 676 } 677 len = howmany(fs->fs_cssize, fs->fs_bsize); 678 for (loc = 0; loc < len; loc++) 679 *blkp++ = blkno + loc; 680 for (; cg < fs->fs_ncg; cg++) 681 *blkp++ = fragstoblks(fs, cgtod(fs, cg)); 682 snapblklist[0] = blkp - snapblklist; 683 VI_LOCK(devvp); 684 if (sn->sn_blklist != NULL) 685 panic("ffs_snapshot: non-empty list"); 686 sn->sn_blklist = snapblklist; 687 sn->sn_listsize = blkp - snapblklist; 688 VI_UNLOCK(devvp); 689 } 690 /* 691 * Preallocate all the direct blocks in the snapshot inode so 692 * that we never have to write the inode itself to commit an 693 * update to the contents of the snapshot. Note that once 694 * created, the size of the snapshot will never change, so 695 * there will never be a need to write the inode except to 696 * update the non-integrity-critical time fields and 697 * allocated-block count. 698 */ 699 for (blockno = 0; blockno < UFS_NDADDR; blockno++) { 700 if (DIP(ip, i_db[blockno]) != 0) 701 continue; 702 error = UFS_BALLOC(vp, lblktosize(fs, blockno), 703 fs->fs_bsize, KERNCRED, BA_CLRBUF, &bp); 704 if (error) 705 goto resumefs; 706 error = readblock(vp, bp, blockno); 707 bawrite(bp); 708 if (error != 0) 709 goto resumefs; 710 } 711 /* 712 * Record snapshot inode. Since this is the newest snapshot, 713 * it must be placed at the end of the list. 714 */ 715 VI_LOCK(devvp); 716 fs->fs_snapinum[snaploc] = ip->i_number; 717 if (ip->i_nextsnap.tqe_prev != 0) 718 panic("ffs_snapshot: %ju already on list", 719 (uintmax_t)ip->i_number); 720 TAILQ_INSERT_TAIL(&sn->sn_head, ip, i_nextsnap); 721 devvp->v_vflag |= VV_COPYONWRITE; 722 VI_UNLOCK(devvp); 723 resumefs: 724 ASSERT_VOP_LOCKED(vp, "ffs_snapshot vp"); 725 if (error != 0 && copy_fs != NULL) { 726 free(copy_fs->fs_csp, M_UFSMNT); 727 free(copy_fs->fs_si, M_UFSMNT); 728 free(copy_fs, M_UFSMNT); 729 copy_fs = NULL; 730 } 731 KASSERT(error != 0 || (sn != NULL && copy_fs != NULL), 732 ("missing snapshot setup parameters")); 733 /* 734 * Resume operation on filesystem. 735 */ 736 vfs_write_resume(vp->v_mount, VR_START_WRITE | VR_NO_SUSPCLR); 737 #ifdef DIAGNOSTIC 738 if (collectsnapstats && starttime.tv_sec > 0) { 739 nanotime(&endtime); 740 timespecsub(&endtime, &starttime, &endtime); 741 printf("%s: suspended %ld.%03ld sec, redo %ld of %d\n", 742 vp->v_mount->mnt_stat.f_mntonname, (long)endtime.tv_sec, 743 endtime.tv_nsec / 1000000, redo, fs->fs_ncg); 744 } 745 #endif 746 if (copy_fs == NULL) 747 goto out; 748 /* 749 * Copy allocation information from all the snapshots in 750 * this snapshot and then expunge them from its view. 751 */ 752 TAILQ_FOREACH(xp, &sn->sn_head, i_nextsnap) { 753 if (xp == ip) 754 break; 755 if (I_IS_UFS1(xp)) 756 error = expunge_ufs1(vp, xp, fs, snapacct_ufs1, 757 BLK_SNAP, 0); 758 else 759 error = expunge_ufs2(vp, xp, fs, snapacct_ufs2, 760 BLK_SNAP, 0); 761 if (error == 0 && xp->i_effnlink == 0) { 762 error = ffs_freefile(ump, 763 copy_fs, 764 vp, 765 xp->i_number, 766 xp->i_mode, NULL); 767 } 768 if (error) { 769 fs->fs_snapinum[snaploc] = 0; 770 goto done; 771 } 772 } 773 /* 774 * Allocate space for the full list of preallocated snapshot blocks. 775 */ 776 snapblklist = malloc(snaplistsize * sizeof(daddr_t), 777 M_UFSMNT, M_WAITOK); 778 ip->i_snapblklist = &snapblklist[1]; 779 /* 780 * Expunge the blocks used by the snapshots from the set of 781 * blocks marked as used in the snapshot bitmaps. Also, collect 782 * the list of allocated blocks in i_snapblklist. 783 */ 784 if (I_IS_UFS1(ip)) 785 error = expunge_ufs1(vp, ip, copy_fs, mapacct_ufs1, 786 BLK_SNAP, 0); 787 else 788 error = expunge_ufs2(vp, ip, copy_fs, mapacct_ufs2, 789 BLK_SNAP, 0); 790 if (error) { 791 fs->fs_snapinum[snaploc] = 0; 792 free(snapblklist, M_UFSMNT); 793 goto done; 794 } 795 if (snaplistsize < ip->i_snapblklist - snapblklist) 796 panic("ffs_snapshot: list too small"); 797 snaplistsize = ip->i_snapblklist - snapblklist; 798 snapblklist[0] = snaplistsize; 799 ip->i_snapblklist = 0; 800 /* 801 * Write out the list of allocated blocks to the end of the snapshot. 802 */ 803 auio.uio_iov = &aiov; 804 auio.uio_iovcnt = 1; 805 aiov.iov_base = (void *)snapblklist; 806 aiov.iov_len = snaplistsize * sizeof(daddr_t); 807 auio.uio_resid = aiov.iov_len; 808 auio.uio_offset = lblktosize(fs, (off_t)numblks); 809 auio.uio_segflg = UIO_SYSSPACE; 810 auio.uio_rw = UIO_WRITE; 811 auio.uio_td = td; 812 if ((error = VOP_WRITE(vp, &auio, IO_UNIT, td->td_ucred)) != 0) { 813 fs->fs_snapinum[snaploc] = 0; 814 free(snapblklist, M_UFSMNT); 815 goto done; 816 } 817 /* 818 * Write the superblock and its summary information 819 * to the snapshot. 820 */ 821 blkno = fragstoblks(fs, fs->fs_csaddr); 822 len = howmany(fs->fs_cssize, fs->fs_bsize); 823 space = copy_fs->fs_csp; 824 for (loc = 0; loc < len; loc++) { 825 error = bread(vp, blkno + loc, fs->fs_bsize, KERNCRED, &nbp); 826 if (error) { 827 fs->fs_snapinum[snaploc] = 0; 828 free(snapblklist, M_UFSMNT); 829 goto done; 830 } 831 bcopy(space, nbp->b_data, fs->fs_bsize); 832 space = (char *)space + fs->fs_bsize; 833 bawrite(nbp); 834 } 835 error = bread(vp, lblkno(fs, fs->fs_sblockloc), fs->fs_bsize, 836 KERNCRED, &nbp); 837 if (error) { 838 brelse(nbp); 839 } else { 840 loc = blkoff(fs, fs->fs_sblockloc); 841 copy_fs->fs_fmod = 0; 842 copy_fs->fs_ckhash = ffs_calc_sbhash(copy_fs); 843 bcopy((char *)copy_fs, &nbp->b_data[loc], (u_int)fs->fs_sbsize); 844 bawrite(nbp); 845 } 846 /* 847 * As this is the newest list, it is the most inclusive, so 848 * should replace the previous list. 849 */ 850 VI_LOCK(devvp); 851 space = sn->sn_blklist; 852 sn->sn_blklist = snapblklist; 853 sn->sn_listsize = snaplistsize; 854 VI_UNLOCK(devvp); 855 if (space != NULL) 856 free(space, M_UFSMNT); 857 done: 858 free(copy_fs->fs_csp, M_UFSMNT); 859 free(copy_fs->fs_si, M_UFSMNT); 860 free(copy_fs, M_UFSMNT); 861 copy_fs = NULL; 862 out: 863 NDFREE(&nd, NDF_ONLY_PNBUF); 864 if (saved_nice > 0) { 865 struct proc *p; 866 867 p = td->td_proc; 868 PROC_LOCK(p); 869 sched_nice(td->td_proc, saved_nice); 870 PROC_UNLOCK(td->td_proc); 871 } 872 UFS_LOCK(ump); 873 if (fs->fs_active != 0) { 874 free(fs->fs_active, M_DEVBUF); 875 fs->fs_active = 0; 876 } 877 UFS_UNLOCK(ump); 878 MNT_ILOCK(mp); 879 mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | (flag & ~MNT_QUOTA); 880 MNT_IUNLOCK(mp); 881 if (error) 882 (void) ffs_truncate(vp, (off_t)0, 0, NOCRED); 883 (void) ffs_syncvnode(vp, MNT_WAIT, 0); 884 if (error) 885 vput(vp); 886 else 887 VOP_UNLOCK(vp); 888 vrele(nd.ni_dvp); 889 vn_finished_write(wrtmp); 890 process_deferred_inactive(mp); 891 return (error); 892 } 893 894 /* 895 * Copy a cylinder group map. All the unallocated blocks are marked 896 * BLK_NOCOPY so that the snapshot knows that it need not copy them 897 * if they are later written. If passno is one, then this is a first 898 * pass, so only setting needs to be done. If passno is 2, then this 899 * is a revision to a previous pass which must be undone as the 900 * replacement pass is done. 901 */ 902 static int 903 cgaccount(cg, vp, nbp, passno) 904 int cg; 905 struct vnode *vp; 906 struct buf *nbp; 907 int passno; 908 { 909 struct buf *bp, *ibp; 910 struct inode *ip; 911 struct cg *cgp; 912 struct fs *fs; 913 ufs2_daddr_t base, numblks; 914 int error, len, loc, indiroff; 915 916 ip = VTOI(vp); 917 fs = ITOFS(ip); 918 if ((error = ffs_getcg(fs, ITODEVVP(ip), cg, 0, &bp, &cgp)) != 0) 919 return (error); 920 UFS_LOCK(ITOUMP(ip)); 921 ACTIVESET(fs, cg); 922 /* 923 * Recomputation of summary information might not have been performed 924 * at mount time. Sync up summary information for current cylinder 925 * group while data is in memory to ensure that result of background 926 * fsck is slightly more consistent. 927 */ 928 fs->fs_cs(fs, cg) = cgp->cg_cs; 929 UFS_UNLOCK(ITOUMP(ip)); 930 bcopy(bp->b_data, nbp->b_data, fs->fs_cgsize); 931 if (fs->fs_cgsize < fs->fs_bsize) 932 bzero(&nbp->b_data[fs->fs_cgsize], 933 fs->fs_bsize - fs->fs_cgsize); 934 cgp = (struct cg *)nbp->b_data; 935 bqrelse(bp); 936 if (passno == 2) 937 nbp->b_flags |= B_VALIDSUSPWRT; 938 numblks = howmany(fs->fs_size, fs->fs_frag); 939 len = howmany(fs->fs_fpg, fs->fs_frag); 940 base = cgbase(fs, cg) / fs->fs_frag; 941 if (base + len >= numblks) 942 len = numblks - base - 1; 943 loc = 0; 944 if (base < UFS_NDADDR) { 945 for ( ; loc < UFS_NDADDR; loc++) { 946 if (ffs_isblock(fs, cg_blksfree(cgp), loc)) 947 DIP_SET(ip, i_db[loc], BLK_NOCOPY); 948 else if (passno == 2 && DIP(ip, i_db[loc])== BLK_NOCOPY) 949 DIP_SET(ip, i_db[loc], 0); 950 else if (passno == 1 && DIP(ip, i_db[loc])== BLK_NOCOPY) 951 panic("ffs_snapshot: lost direct block"); 952 } 953 } 954 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(base + loc)), 955 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 956 if (error) { 957 goto out; 958 } 959 indiroff = (base + loc - UFS_NDADDR) % NINDIR(fs); 960 for ( ; loc < len; loc++, indiroff++) { 961 if (indiroff >= NINDIR(fs)) { 962 if (passno == 2) 963 ibp->b_flags |= B_VALIDSUSPWRT; 964 bawrite(ibp); 965 error = UFS_BALLOC(vp, 966 lblktosize(fs, (off_t)(base + loc)), 967 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 968 if (error) { 969 goto out; 970 } 971 indiroff = 0; 972 } 973 if (I_IS_UFS1(ip)) { 974 if (ffs_isblock(fs, cg_blksfree(cgp), loc)) 975 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] = 976 BLK_NOCOPY; 977 else if (passno == 2 && ((ufs1_daddr_t *)(ibp->b_data)) 978 [indiroff] == BLK_NOCOPY) 979 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] = 0; 980 else if (passno == 1 && ((ufs1_daddr_t *)(ibp->b_data)) 981 [indiroff] == BLK_NOCOPY) 982 panic("ffs_snapshot: lost indirect block"); 983 continue; 984 } 985 if (ffs_isblock(fs, cg_blksfree(cgp), loc)) 986 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = BLK_NOCOPY; 987 else if (passno == 2 && 988 ((ufs2_daddr_t *)(ibp->b_data)) [indiroff] == BLK_NOCOPY) 989 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = 0; 990 else if (passno == 1 && 991 ((ufs2_daddr_t *)(ibp->b_data)) [indiroff] == BLK_NOCOPY) 992 panic("ffs_snapshot: lost indirect block"); 993 } 994 if (passno == 2) 995 ibp->b_flags |= B_VALIDSUSPWRT; 996 bdwrite(ibp); 997 out: 998 /* 999 * We have to calculate the crc32c here rather than just setting the 1000 * BX_CYLGRP b_xflags because the allocation of the block for the 1001 * the cylinder group map will always be a full size block (fs_bsize) 1002 * even though the cylinder group may be smaller (fs_cgsize). The 1003 * crc32c must be computed only over fs_cgsize whereas the BX_CYLGRP 1004 * flag causes it to be computed over the size of the buffer. 1005 */ 1006 if ((fs->fs_metackhash & CK_CYLGRP) != 0) { 1007 ((struct cg *)nbp->b_data)->cg_ckhash = 0; 1008 ((struct cg *)nbp->b_data)->cg_ckhash = 1009 calculate_crc32c(~0L, nbp->b_data, fs->fs_cgsize); 1010 } 1011 return (error); 1012 } 1013 1014 /* 1015 * Before expunging a snapshot inode, note all the 1016 * blocks that it claims with BLK_SNAP so that fsck will 1017 * be able to account for those blocks properly and so 1018 * that this snapshot knows that it need not copy them 1019 * if the other snapshot holding them is freed. This code 1020 * is reproduced once each for UFS1 and UFS2. 1021 */ 1022 static int 1023 expunge_ufs1(snapvp, cancelip, fs, acctfunc, expungetype, clearmode) 1024 struct vnode *snapvp; 1025 struct inode *cancelip; 1026 struct fs *fs; 1027 int (*acctfunc)(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, 1028 struct fs *, ufs_lbn_t, int); 1029 int expungetype; 1030 int clearmode; 1031 { 1032 int i, error, indiroff; 1033 ufs_lbn_t lbn, rlbn; 1034 ufs2_daddr_t len, blkno, numblks, blksperindir; 1035 struct ufs1_dinode *dip; 1036 struct thread *td = curthread; 1037 struct buf *bp; 1038 1039 /* 1040 * Prepare to expunge the inode. If its inode block has not 1041 * yet been copied, then allocate and fill the copy. 1042 */ 1043 lbn = fragstoblks(fs, ino_to_fsba(fs, cancelip->i_number)); 1044 blkno = 0; 1045 if (lbn < UFS_NDADDR) { 1046 blkno = VTOI(snapvp)->i_din1->di_db[lbn]; 1047 } else { 1048 if (DOINGSOFTDEP(snapvp)) 1049 softdep_prealloc(snapvp, MNT_WAIT); 1050 td->td_pflags |= TDP_COWINPROGRESS; 1051 error = ffs_balloc_ufs1(snapvp, lblktosize(fs, (off_t)lbn), 1052 fs->fs_bsize, KERNCRED, BA_METAONLY, &bp); 1053 td->td_pflags &= ~TDP_COWINPROGRESS; 1054 if (error) 1055 return (error); 1056 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs); 1057 blkno = ((ufs1_daddr_t *)(bp->b_data))[indiroff]; 1058 bqrelse(bp); 1059 } 1060 if (blkno != 0) { 1061 if ((error = bread(snapvp, lbn, fs->fs_bsize, KERNCRED, &bp))) 1062 return (error); 1063 } else { 1064 error = ffs_balloc_ufs1(snapvp, lblktosize(fs, (off_t)lbn), 1065 fs->fs_bsize, KERNCRED, 0, &bp); 1066 if (error) 1067 return (error); 1068 if ((error = readblock(snapvp, bp, lbn)) != 0) 1069 return (error); 1070 } 1071 /* 1072 * Set a snapshot inode to be a zero length file, regular files 1073 * or unlinked snapshots to be completely unallocated. 1074 */ 1075 dip = (struct ufs1_dinode *)bp->b_data + 1076 ino_to_fsbo(fs, cancelip->i_number); 1077 if (clearmode || cancelip->i_effnlink == 0) 1078 dip->di_mode = 0; 1079 dip->di_size = 0; 1080 dip->di_blocks = 0; 1081 dip->di_flags &= ~SF_SNAPSHOT; 1082 bzero(&dip->di_db[0], (UFS_NDADDR + UFS_NIADDR) * sizeof(ufs1_daddr_t)); 1083 bdwrite(bp); 1084 /* 1085 * Now go through and expunge all the blocks in the file 1086 * using the function requested. 1087 */ 1088 numblks = howmany(cancelip->i_size, fs->fs_bsize); 1089 if ((error = (*acctfunc)(snapvp, &cancelip->i_din1->di_db[0], 1090 &cancelip->i_din1->di_db[UFS_NDADDR], fs, 0, expungetype))) 1091 return (error); 1092 if ((error = (*acctfunc)(snapvp, &cancelip->i_din1->di_ib[0], 1093 &cancelip->i_din1->di_ib[UFS_NIADDR], fs, -1, expungetype))) 1094 return (error); 1095 blksperindir = 1; 1096 lbn = -UFS_NDADDR; 1097 len = numblks - UFS_NDADDR; 1098 rlbn = UFS_NDADDR; 1099 for (i = 0; len > 0 && i < UFS_NIADDR; i++) { 1100 error = indiracct_ufs1(snapvp, ITOV(cancelip), i, 1101 cancelip->i_din1->di_ib[i], lbn, rlbn, len, 1102 blksperindir, fs, acctfunc, expungetype); 1103 if (error) 1104 return (error); 1105 blksperindir *= NINDIR(fs); 1106 lbn -= blksperindir + 1; 1107 len -= blksperindir; 1108 rlbn += blksperindir; 1109 } 1110 return (0); 1111 } 1112 1113 /* 1114 * Descend an indirect block chain for vnode cancelvp accounting for all 1115 * its indirect blocks in snapvp. 1116 */ 1117 static int 1118 indiracct_ufs1(snapvp, cancelvp, level, blkno, lbn, rlbn, remblks, 1119 blksperindir, fs, acctfunc, expungetype) 1120 struct vnode *snapvp; 1121 struct vnode *cancelvp; 1122 int level; 1123 ufs1_daddr_t blkno; 1124 ufs_lbn_t lbn; 1125 ufs_lbn_t rlbn; 1126 ufs_lbn_t remblks; 1127 ufs_lbn_t blksperindir; 1128 struct fs *fs; 1129 int (*acctfunc)(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, 1130 struct fs *, ufs_lbn_t, int); 1131 int expungetype; 1132 { 1133 int error, num, i; 1134 ufs_lbn_t subblksperindir; 1135 struct indir indirs[UFS_NIADDR + 2]; 1136 ufs1_daddr_t last, *bap; 1137 struct buf *bp; 1138 1139 if (blkno == 0) { 1140 if (expungetype == BLK_NOCOPY) 1141 return (0); 1142 panic("indiracct_ufs1: missing indir"); 1143 } 1144 if ((error = ufs_getlbns(cancelvp, rlbn, indirs, &num)) != 0) 1145 return (error); 1146 if (lbn != indirs[num - 1 - level].in_lbn || num < 2) 1147 panic("indiracct_ufs1: botched params"); 1148 /* 1149 * We have to expand bread here since it will deadlock looking 1150 * up the block number for any blocks that are not in the cache. 1151 */ 1152 bp = getblk(cancelvp, lbn, fs->fs_bsize, 0, 0, 0); 1153 bp->b_blkno = fsbtodb(fs, blkno); 1154 if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0 && 1155 (error = readblock(cancelvp, bp, fragstoblks(fs, blkno)))) { 1156 brelse(bp); 1157 return (error); 1158 } 1159 /* 1160 * Account for the block pointers in this indirect block. 1161 */ 1162 last = howmany(remblks, blksperindir); 1163 if (last > NINDIR(fs)) 1164 last = NINDIR(fs); 1165 bap = malloc(fs->fs_bsize, M_DEVBUF, M_WAITOK); 1166 bcopy(bp->b_data, (caddr_t)bap, fs->fs_bsize); 1167 bqrelse(bp); 1168 error = (*acctfunc)(snapvp, &bap[0], &bap[last], fs, 1169 level == 0 ? rlbn : -1, expungetype); 1170 if (error || level == 0) 1171 goto out; 1172 /* 1173 * Account for the block pointers in each of the indirect blocks 1174 * in the levels below us. 1175 */ 1176 subblksperindir = blksperindir / NINDIR(fs); 1177 for (lbn++, level--, i = 0; i < last; i++) { 1178 error = indiracct_ufs1(snapvp, cancelvp, level, bap[i], lbn, 1179 rlbn, remblks, subblksperindir, fs, acctfunc, expungetype); 1180 if (error) 1181 goto out; 1182 rlbn += blksperindir; 1183 lbn -= blksperindir; 1184 remblks -= blksperindir; 1185 } 1186 out: 1187 free(bap, M_DEVBUF); 1188 return (error); 1189 } 1190 1191 /* 1192 * Do both snap accounting and map accounting. 1193 */ 1194 static int 1195 fullacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, exptype) 1196 struct vnode *vp; 1197 ufs1_daddr_t *oldblkp, *lastblkp; 1198 struct fs *fs; 1199 ufs_lbn_t lblkno; 1200 int exptype; /* BLK_SNAP or BLK_NOCOPY */ 1201 { 1202 int error; 1203 1204 if ((error = snapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, exptype))) 1205 return (error); 1206 return (mapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, exptype)); 1207 } 1208 1209 /* 1210 * Identify a set of blocks allocated in a snapshot inode. 1211 */ 1212 static int 1213 snapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, expungetype) 1214 struct vnode *vp; 1215 ufs1_daddr_t *oldblkp, *lastblkp; 1216 struct fs *fs; 1217 ufs_lbn_t lblkno; 1218 int expungetype; /* BLK_SNAP or BLK_NOCOPY */ 1219 { 1220 struct inode *ip = VTOI(vp); 1221 ufs1_daddr_t blkno, *blkp; 1222 ufs_lbn_t lbn; 1223 struct buf *ibp; 1224 int error; 1225 1226 for ( ; oldblkp < lastblkp; oldblkp++) { 1227 blkno = *oldblkp; 1228 if (blkno == 0 || blkno == BLK_NOCOPY || blkno == BLK_SNAP) 1229 continue; 1230 lbn = fragstoblks(fs, blkno); 1231 if (lbn < UFS_NDADDR) { 1232 blkp = &ip->i_din1->di_db[lbn]; 1233 UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE); 1234 } else { 1235 error = ffs_balloc_ufs1(vp, lblktosize(fs, (off_t)lbn), 1236 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 1237 if (error) 1238 return (error); 1239 blkp = &((ufs1_daddr_t *)(ibp->b_data)) 1240 [(lbn - UFS_NDADDR) % NINDIR(fs)]; 1241 } 1242 /* 1243 * If we are expunging a snapshot vnode and we 1244 * find a block marked BLK_NOCOPY, then it is 1245 * one that has been allocated to this snapshot after 1246 * we took our current snapshot and can be ignored. 1247 */ 1248 if (expungetype == BLK_SNAP && *blkp == BLK_NOCOPY) { 1249 if (lbn >= UFS_NDADDR) 1250 brelse(ibp); 1251 } else { 1252 if (*blkp != 0) 1253 panic("snapacct_ufs1: bad block"); 1254 *blkp = expungetype; 1255 if (lbn >= UFS_NDADDR) 1256 bdwrite(ibp); 1257 } 1258 } 1259 return (0); 1260 } 1261 1262 /* 1263 * Account for a set of blocks allocated in a snapshot inode. 1264 */ 1265 static int 1266 mapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, expungetype) 1267 struct vnode *vp; 1268 ufs1_daddr_t *oldblkp, *lastblkp; 1269 struct fs *fs; 1270 ufs_lbn_t lblkno; 1271 int expungetype; 1272 { 1273 ufs1_daddr_t blkno; 1274 struct inode *ip; 1275 ino_t inum; 1276 int acctit; 1277 1278 ip = VTOI(vp); 1279 inum = ip->i_number; 1280 if (lblkno == -1) 1281 acctit = 0; 1282 else 1283 acctit = 1; 1284 for ( ; oldblkp < lastblkp; oldblkp++, lblkno++) { 1285 blkno = *oldblkp; 1286 if (blkno == 0 || blkno == BLK_NOCOPY) 1287 continue; 1288 if (acctit && expungetype == BLK_SNAP && blkno != BLK_SNAP) 1289 *ip->i_snapblklist++ = lblkno; 1290 if (blkno == BLK_SNAP) 1291 blkno = blkstofrags(fs, lblkno); 1292 ffs_blkfree(ITOUMP(ip), fs, vp, blkno, fs->fs_bsize, inum, 1293 vp->v_type, NULL, SINGLETON_KEY); 1294 } 1295 return (0); 1296 } 1297 1298 /* 1299 * Before expunging a snapshot inode, note all the 1300 * blocks that it claims with BLK_SNAP so that fsck will 1301 * be able to account for those blocks properly and so 1302 * that this snapshot knows that it need not copy them 1303 * if the other snapshot holding them is freed. This code 1304 * is reproduced once each for UFS1 and UFS2. 1305 */ 1306 static int 1307 expunge_ufs2(snapvp, cancelip, fs, acctfunc, expungetype, clearmode) 1308 struct vnode *snapvp; 1309 struct inode *cancelip; 1310 struct fs *fs; 1311 int (*acctfunc)(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, 1312 struct fs *, ufs_lbn_t, int); 1313 int expungetype; 1314 int clearmode; 1315 { 1316 int i, error, indiroff; 1317 ufs_lbn_t lbn, rlbn; 1318 ufs2_daddr_t len, blkno, numblks, blksperindir; 1319 struct ufs2_dinode *dip; 1320 struct thread *td = curthread; 1321 struct buf *bp; 1322 1323 /* 1324 * Prepare to expunge the inode. If its inode block has not 1325 * yet been copied, then allocate and fill the copy. 1326 */ 1327 lbn = fragstoblks(fs, ino_to_fsba(fs, cancelip->i_number)); 1328 blkno = 0; 1329 if (lbn < UFS_NDADDR) { 1330 blkno = VTOI(snapvp)->i_din2->di_db[lbn]; 1331 } else { 1332 if (DOINGSOFTDEP(snapvp)) 1333 softdep_prealloc(snapvp, MNT_WAIT); 1334 td->td_pflags |= TDP_COWINPROGRESS; 1335 error = ffs_balloc_ufs2(snapvp, lblktosize(fs, (off_t)lbn), 1336 fs->fs_bsize, KERNCRED, BA_METAONLY, &bp); 1337 td->td_pflags &= ~TDP_COWINPROGRESS; 1338 if (error) 1339 return (error); 1340 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs); 1341 blkno = ((ufs2_daddr_t *)(bp->b_data))[indiroff]; 1342 bqrelse(bp); 1343 } 1344 if (blkno != 0) { 1345 if ((error = bread(snapvp, lbn, fs->fs_bsize, KERNCRED, &bp))) 1346 return (error); 1347 } else { 1348 error = ffs_balloc_ufs2(snapvp, lblktosize(fs, (off_t)lbn), 1349 fs->fs_bsize, KERNCRED, 0, &bp); 1350 if (error) 1351 return (error); 1352 if ((error = readblock(snapvp, bp, lbn)) != 0) 1353 return (error); 1354 } 1355 /* 1356 * Set a snapshot inode to be a zero length file, regular files 1357 * to be completely unallocated. 1358 */ 1359 dip = (struct ufs2_dinode *)bp->b_data + 1360 ino_to_fsbo(fs, cancelip->i_number); 1361 dip->di_size = 0; 1362 dip->di_blocks = 0; 1363 dip->di_flags &= ~SF_SNAPSHOT; 1364 bzero(&dip->di_db[0], (UFS_NDADDR + UFS_NIADDR) * sizeof(ufs2_daddr_t)); 1365 if (clearmode || cancelip->i_effnlink == 0) 1366 dip->di_mode = 0; 1367 else 1368 ffs_update_dinode_ckhash(fs, dip); 1369 bdwrite(bp); 1370 /* 1371 * Now go through and expunge all the blocks in the file 1372 * using the function requested. 1373 */ 1374 numblks = howmany(cancelip->i_size, fs->fs_bsize); 1375 if ((error = (*acctfunc)(snapvp, &cancelip->i_din2->di_db[0], 1376 &cancelip->i_din2->di_db[UFS_NDADDR], fs, 0, expungetype))) 1377 return (error); 1378 if ((error = (*acctfunc)(snapvp, &cancelip->i_din2->di_ib[0], 1379 &cancelip->i_din2->di_ib[UFS_NIADDR], fs, -1, expungetype))) 1380 return (error); 1381 blksperindir = 1; 1382 lbn = -UFS_NDADDR; 1383 len = numblks - UFS_NDADDR; 1384 rlbn = UFS_NDADDR; 1385 for (i = 0; len > 0 && i < UFS_NIADDR; i++) { 1386 error = indiracct_ufs2(snapvp, ITOV(cancelip), i, 1387 cancelip->i_din2->di_ib[i], lbn, rlbn, len, 1388 blksperindir, fs, acctfunc, expungetype); 1389 if (error) 1390 return (error); 1391 blksperindir *= NINDIR(fs); 1392 lbn -= blksperindir + 1; 1393 len -= blksperindir; 1394 rlbn += blksperindir; 1395 } 1396 return (0); 1397 } 1398 1399 /* 1400 * Descend an indirect block chain for vnode cancelvp accounting for all 1401 * its indirect blocks in snapvp. 1402 */ 1403 static int 1404 indiracct_ufs2(snapvp, cancelvp, level, blkno, lbn, rlbn, remblks, 1405 blksperindir, fs, acctfunc, expungetype) 1406 struct vnode *snapvp; 1407 struct vnode *cancelvp; 1408 int level; 1409 ufs2_daddr_t blkno; 1410 ufs_lbn_t lbn; 1411 ufs_lbn_t rlbn; 1412 ufs_lbn_t remblks; 1413 ufs_lbn_t blksperindir; 1414 struct fs *fs; 1415 int (*acctfunc)(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, 1416 struct fs *, ufs_lbn_t, int); 1417 int expungetype; 1418 { 1419 int error, num, i; 1420 ufs_lbn_t subblksperindir; 1421 struct indir indirs[UFS_NIADDR + 2]; 1422 ufs2_daddr_t last, *bap; 1423 struct buf *bp; 1424 1425 if (blkno == 0) { 1426 if (expungetype == BLK_NOCOPY) 1427 return (0); 1428 panic("indiracct_ufs2: missing indir"); 1429 } 1430 if ((error = ufs_getlbns(cancelvp, rlbn, indirs, &num)) != 0) 1431 return (error); 1432 if (lbn != indirs[num - 1 - level].in_lbn || num < 2) 1433 panic("indiracct_ufs2: botched params"); 1434 /* 1435 * We have to expand bread here since it will deadlock looking 1436 * up the block number for any blocks that are not in the cache. 1437 */ 1438 bp = getblk(cancelvp, lbn, fs->fs_bsize, 0, 0, 0); 1439 bp->b_blkno = fsbtodb(fs, blkno); 1440 if ((bp->b_flags & B_CACHE) == 0 && 1441 (error = readblock(cancelvp, bp, fragstoblks(fs, blkno)))) { 1442 brelse(bp); 1443 return (error); 1444 } 1445 /* 1446 * Account for the block pointers in this indirect block. 1447 */ 1448 last = howmany(remblks, blksperindir); 1449 if (last > NINDIR(fs)) 1450 last = NINDIR(fs); 1451 bap = malloc(fs->fs_bsize, M_DEVBUF, M_WAITOK); 1452 bcopy(bp->b_data, (caddr_t)bap, fs->fs_bsize); 1453 bqrelse(bp); 1454 error = (*acctfunc)(snapvp, &bap[0], &bap[last], fs, 1455 level == 0 ? rlbn : -1, expungetype); 1456 if (error || level == 0) 1457 goto out; 1458 /* 1459 * Account for the block pointers in each of the indirect blocks 1460 * in the levels below us. 1461 */ 1462 subblksperindir = blksperindir / NINDIR(fs); 1463 for (lbn++, level--, i = 0; i < last; i++) { 1464 error = indiracct_ufs2(snapvp, cancelvp, level, bap[i], lbn, 1465 rlbn, remblks, subblksperindir, fs, acctfunc, expungetype); 1466 if (error) 1467 goto out; 1468 rlbn += blksperindir; 1469 lbn -= blksperindir; 1470 remblks -= blksperindir; 1471 } 1472 out: 1473 free(bap, M_DEVBUF); 1474 return (error); 1475 } 1476 1477 /* 1478 * Do both snap accounting and map accounting. 1479 */ 1480 static int 1481 fullacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, exptype) 1482 struct vnode *vp; 1483 ufs2_daddr_t *oldblkp, *lastblkp; 1484 struct fs *fs; 1485 ufs_lbn_t lblkno; 1486 int exptype; /* BLK_SNAP or BLK_NOCOPY */ 1487 { 1488 int error; 1489 1490 if ((error = snapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, exptype))) 1491 return (error); 1492 return (mapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, exptype)); 1493 } 1494 1495 /* 1496 * Identify a set of blocks allocated in a snapshot inode. 1497 */ 1498 static int 1499 snapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, expungetype) 1500 struct vnode *vp; 1501 ufs2_daddr_t *oldblkp, *lastblkp; 1502 struct fs *fs; 1503 ufs_lbn_t lblkno; 1504 int expungetype; /* BLK_SNAP or BLK_NOCOPY */ 1505 { 1506 struct inode *ip = VTOI(vp); 1507 ufs2_daddr_t blkno, *blkp; 1508 ufs_lbn_t lbn; 1509 struct buf *ibp; 1510 int error; 1511 1512 for ( ; oldblkp < lastblkp; oldblkp++) { 1513 blkno = *oldblkp; 1514 if (blkno == 0 || blkno == BLK_NOCOPY || blkno == BLK_SNAP) 1515 continue; 1516 lbn = fragstoblks(fs, blkno); 1517 if (lbn < UFS_NDADDR) { 1518 blkp = &ip->i_din2->di_db[lbn]; 1519 UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE); 1520 } else { 1521 error = ffs_balloc_ufs2(vp, lblktosize(fs, (off_t)lbn), 1522 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 1523 if (error) 1524 return (error); 1525 blkp = &((ufs2_daddr_t *)(ibp->b_data)) 1526 [(lbn - UFS_NDADDR) % NINDIR(fs)]; 1527 } 1528 /* 1529 * If we are expunging a snapshot vnode and we 1530 * find a block marked BLK_NOCOPY, then it is 1531 * one that has been allocated to this snapshot after 1532 * we took our current snapshot and can be ignored. 1533 */ 1534 if (expungetype == BLK_SNAP && *blkp == BLK_NOCOPY) { 1535 if (lbn >= UFS_NDADDR) 1536 brelse(ibp); 1537 } else { 1538 if (*blkp != 0) 1539 panic("snapacct_ufs2: bad block"); 1540 *blkp = expungetype; 1541 if (lbn >= UFS_NDADDR) 1542 bdwrite(ibp); 1543 } 1544 } 1545 return (0); 1546 } 1547 1548 /* 1549 * Account for a set of blocks allocated in a snapshot inode. 1550 */ 1551 static int 1552 mapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, expungetype) 1553 struct vnode *vp; 1554 ufs2_daddr_t *oldblkp, *lastblkp; 1555 struct fs *fs; 1556 ufs_lbn_t lblkno; 1557 int expungetype; 1558 { 1559 ufs2_daddr_t blkno; 1560 struct inode *ip; 1561 ino_t inum; 1562 int acctit; 1563 1564 ip = VTOI(vp); 1565 inum = ip->i_number; 1566 if (lblkno == -1) 1567 acctit = 0; 1568 else 1569 acctit = 1; 1570 for ( ; oldblkp < lastblkp; oldblkp++, lblkno++) { 1571 blkno = *oldblkp; 1572 if (blkno == 0 || blkno == BLK_NOCOPY) 1573 continue; 1574 if (acctit && expungetype == BLK_SNAP && blkno != BLK_SNAP && 1575 lblkno >= UFS_NDADDR) 1576 *ip->i_snapblklist++ = lblkno; 1577 if (blkno == BLK_SNAP) 1578 blkno = blkstofrags(fs, lblkno); 1579 ffs_blkfree(ITOUMP(ip), fs, vp, blkno, fs->fs_bsize, inum, 1580 vp->v_type, NULL, SINGLETON_KEY); 1581 } 1582 return (0); 1583 } 1584 1585 /* 1586 * Decrement extra reference on snapshot when last name is removed. 1587 * It will not be freed until the last open reference goes away. 1588 */ 1589 void 1590 ffs_snapgone(ip) 1591 struct inode *ip; 1592 { 1593 struct inode *xp; 1594 struct fs *fs; 1595 int snaploc; 1596 struct snapdata *sn; 1597 struct ufsmount *ump; 1598 1599 /* 1600 * Find snapshot in incore list. 1601 */ 1602 xp = NULL; 1603 sn = ITODEVVP(ip)->v_rdev->si_snapdata; 1604 if (sn != NULL) 1605 TAILQ_FOREACH(xp, &sn->sn_head, i_nextsnap) 1606 if (xp == ip) 1607 break; 1608 if (xp != NULL) 1609 vrele(ITOV(ip)); 1610 #ifdef DIAGNOSTIC 1611 else if (snapdebug) 1612 printf("ffs_snapgone: lost snapshot vnode %ju\n", 1613 (uintmax_t)ip->i_number); 1614 #endif 1615 /* 1616 * Delete snapshot inode from superblock. Keep list dense. 1617 */ 1618 ump = ITOUMP(ip); 1619 fs = ump->um_fs; 1620 UFS_LOCK(ump); 1621 for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++) 1622 if (fs->fs_snapinum[snaploc] == ip->i_number) 1623 break; 1624 if (snaploc < FSMAXSNAP) { 1625 for (snaploc++; snaploc < FSMAXSNAP; snaploc++) { 1626 if (fs->fs_snapinum[snaploc] == 0) 1627 break; 1628 fs->fs_snapinum[snaploc - 1] = fs->fs_snapinum[snaploc]; 1629 } 1630 fs->fs_snapinum[snaploc - 1] = 0; 1631 } 1632 UFS_UNLOCK(ump); 1633 } 1634 1635 /* 1636 * Prepare a snapshot file for being removed. 1637 */ 1638 void 1639 ffs_snapremove(vp) 1640 struct vnode *vp; 1641 { 1642 struct inode *ip; 1643 struct vnode *devvp; 1644 struct buf *ibp; 1645 struct fs *fs; 1646 ufs2_daddr_t numblks, blkno, dblk; 1647 int error, i, last, loc; 1648 struct snapdata *sn; 1649 1650 ip = VTOI(vp); 1651 fs = ITOFS(ip); 1652 devvp = ITODEVVP(ip); 1653 /* 1654 * If active, delete from incore list (this snapshot may 1655 * already have been in the process of being deleted, so 1656 * would not have been active). 1657 * 1658 * Clear copy-on-write flag if last snapshot. 1659 */ 1660 VI_LOCK(devvp); 1661 if (ip->i_nextsnap.tqe_prev != 0) { 1662 sn = devvp->v_rdev->si_snapdata; 1663 TAILQ_REMOVE(&sn->sn_head, ip, i_nextsnap); 1664 ip->i_nextsnap.tqe_prev = 0; 1665 VI_UNLOCK(devvp); 1666 lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL); 1667 for (i = 0; i < sn->sn_lock.lk_recurse; i++) 1668 lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL); 1669 KASSERT(vp->v_vnlock == &sn->sn_lock, 1670 ("ffs_snapremove: lost lock mutation")); 1671 vp->v_vnlock = &vp->v_lock; 1672 VI_LOCK(devvp); 1673 while (sn->sn_lock.lk_recurse > 0) 1674 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 1675 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 1676 try_free_snapdata(devvp); 1677 } else 1678 VI_UNLOCK(devvp); 1679 /* 1680 * Clear all BLK_NOCOPY fields. Pass any block claims to other 1681 * snapshots that want them (see ffs_snapblkfree below). 1682 */ 1683 for (blkno = 1; blkno < UFS_NDADDR; blkno++) { 1684 dblk = DIP(ip, i_db[blkno]); 1685 if (dblk == 0) 1686 continue; 1687 if (dblk == BLK_NOCOPY || dblk == BLK_SNAP) 1688 DIP_SET(ip, i_db[blkno], 0); 1689 else if ((dblk == blkstofrags(fs, blkno) && 1690 ffs_snapblkfree(fs, ITODEVVP(ip), dblk, fs->fs_bsize, 1691 ip->i_number, vp->v_type, NULL))) { 1692 DIP_SET(ip, i_blocks, DIP(ip, i_blocks) - 1693 btodb(fs->fs_bsize)); 1694 DIP_SET(ip, i_db[blkno], 0); 1695 } 1696 } 1697 numblks = howmany(ip->i_size, fs->fs_bsize); 1698 for (blkno = UFS_NDADDR; blkno < numblks; blkno += NINDIR(fs)) { 1699 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)blkno), 1700 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 1701 if (error) 1702 continue; 1703 if (fs->fs_size - blkno > NINDIR(fs)) 1704 last = NINDIR(fs); 1705 else 1706 last = fs->fs_size - blkno; 1707 for (loc = 0; loc < last; loc++) { 1708 if (I_IS_UFS1(ip)) { 1709 dblk = ((ufs1_daddr_t *)(ibp->b_data))[loc]; 1710 if (dblk == 0) 1711 continue; 1712 if (dblk == BLK_NOCOPY || dblk == BLK_SNAP) 1713 ((ufs1_daddr_t *)(ibp->b_data))[loc]= 0; 1714 else if ((dblk == blkstofrags(fs, blkno) && 1715 ffs_snapblkfree(fs, ITODEVVP(ip), dblk, 1716 fs->fs_bsize, ip->i_number, vp->v_type, 1717 NULL))) { 1718 ip->i_din1->di_blocks -= 1719 btodb(fs->fs_bsize); 1720 ((ufs1_daddr_t *)(ibp->b_data))[loc]= 0; 1721 } 1722 continue; 1723 } 1724 dblk = ((ufs2_daddr_t *)(ibp->b_data))[loc]; 1725 if (dblk == 0) 1726 continue; 1727 if (dblk == BLK_NOCOPY || dblk == BLK_SNAP) 1728 ((ufs2_daddr_t *)(ibp->b_data))[loc] = 0; 1729 else if ((dblk == blkstofrags(fs, blkno) && 1730 ffs_snapblkfree(fs, ITODEVVP(ip), dblk, 1731 fs->fs_bsize, ip->i_number, vp->v_type, NULL))) { 1732 ip->i_din2->di_blocks -= btodb(fs->fs_bsize); 1733 ((ufs2_daddr_t *)(ibp->b_data))[loc] = 0; 1734 } 1735 } 1736 bawrite(ibp); 1737 } 1738 /* 1739 * Clear snapshot flag and drop reference. 1740 */ 1741 ip->i_flags &= ~SF_SNAPSHOT; 1742 DIP_SET(ip, i_flags, ip->i_flags); 1743 UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE); 1744 /* 1745 * The dirtied indirects must be written out before 1746 * softdep_setup_freeblocks() is called. Otherwise indir_trunc() 1747 * may find indirect pointers using the magic BLK_* values. 1748 */ 1749 if (DOINGSOFTDEP(vp)) 1750 ffs_syncvnode(vp, MNT_WAIT, 0); 1751 #ifdef QUOTA 1752 /* 1753 * Reenable disk quotas for ex-snapshot file. 1754 */ 1755 if (!getinoquota(ip)) 1756 (void) chkdq(ip, DIP(ip, i_blocks), KERNCRED, FORCE); 1757 #endif 1758 } 1759 1760 /* 1761 * Notification that a block is being freed. Return zero if the free 1762 * should be allowed to proceed. Return non-zero if the snapshot file 1763 * wants to claim the block. The block will be claimed if it is an 1764 * uncopied part of one of the snapshots. It will be freed if it is 1765 * either a BLK_NOCOPY or has already been copied in all of the snapshots. 1766 * If a fragment is being freed, then all snapshots that care about 1767 * it must make a copy since a snapshot file can only claim full sized 1768 * blocks. Note that if more than one snapshot file maps the block, 1769 * we can pick one at random to claim it. Since none of the snapshots 1770 * can change, we are assurred that they will all see the same unmodified 1771 * image. When deleting a snapshot file (see ffs_snapremove above), we 1772 * must push any of these claimed blocks to one of the other snapshots 1773 * that maps it. These claimed blocks are easily identified as they will 1774 * have a block number equal to their logical block number within the 1775 * snapshot. A copied block can never have this property because they 1776 * must always have been allocated from a BLK_NOCOPY location. 1777 */ 1778 int 1779 ffs_snapblkfree(fs, devvp, bno, size, inum, vtype, wkhd) 1780 struct fs *fs; 1781 struct vnode *devvp; 1782 ufs2_daddr_t bno; 1783 long size; 1784 ino_t inum; 1785 enum vtype vtype; 1786 struct workhead *wkhd; 1787 { 1788 struct buf *ibp, *cbp, *savedcbp = NULL; 1789 struct thread *td = curthread; 1790 struct inode *ip; 1791 struct vnode *vp = NULL; 1792 ufs_lbn_t lbn; 1793 ufs2_daddr_t blkno; 1794 int indiroff = 0, error = 0, claimedblk = 0; 1795 struct snapdata *sn; 1796 1797 lbn = fragstoblks(fs, bno); 1798 retry: 1799 VI_LOCK(devvp); 1800 sn = devvp->v_rdev->si_snapdata; 1801 if (sn == NULL) { 1802 VI_UNLOCK(devvp); 1803 return (0); 1804 } 1805 if (lockmgr(&sn->sn_lock, LK_INTERLOCK | LK_EXCLUSIVE | LK_SLEEPFAIL, 1806 VI_MTX(devvp)) != 0) 1807 goto retry; 1808 TAILQ_FOREACH(ip, &sn->sn_head, i_nextsnap) { 1809 vp = ITOV(ip); 1810 if (DOINGSOFTDEP(vp)) 1811 softdep_prealloc(vp, MNT_WAIT); 1812 /* 1813 * Lookup block being written. 1814 */ 1815 if (lbn < UFS_NDADDR) { 1816 blkno = DIP(ip, i_db[lbn]); 1817 } else { 1818 td->td_pflags |= TDP_COWINPROGRESS; 1819 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn), 1820 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 1821 td->td_pflags &= ~TDP_COWINPROGRESS; 1822 if (error) 1823 break; 1824 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs); 1825 if (I_IS_UFS1(ip)) 1826 blkno=((ufs1_daddr_t *)(ibp->b_data))[indiroff]; 1827 else 1828 blkno=((ufs2_daddr_t *)(ibp->b_data))[indiroff]; 1829 } 1830 /* 1831 * Check to see if block needs to be copied. 1832 */ 1833 if (blkno == 0) { 1834 /* 1835 * A block that we map is being freed. If it has not 1836 * been claimed yet, we will claim or copy it (below). 1837 */ 1838 claimedblk = 1; 1839 } else if (blkno == BLK_SNAP) { 1840 /* 1841 * No previous snapshot claimed the block, 1842 * so it will be freed and become a BLK_NOCOPY 1843 * (don't care) for us. 1844 */ 1845 if (claimedblk) 1846 panic("snapblkfree: inconsistent block type"); 1847 if (lbn < UFS_NDADDR) { 1848 DIP_SET(ip, i_db[lbn], BLK_NOCOPY); 1849 UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE); 1850 } else if (I_IS_UFS1(ip)) { 1851 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] = 1852 BLK_NOCOPY; 1853 bdwrite(ibp); 1854 } else { 1855 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = 1856 BLK_NOCOPY; 1857 bdwrite(ibp); 1858 } 1859 continue; 1860 } else /* BLK_NOCOPY or default */ { 1861 /* 1862 * If the snapshot has already copied the block 1863 * (default), or does not care about the block, 1864 * it is not needed. 1865 */ 1866 if (lbn >= UFS_NDADDR) 1867 bqrelse(ibp); 1868 continue; 1869 } 1870 /* 1871 * If this is a full size block, we will just grab it 1872 * and assign it to the snapshot inode. Otherwise we 1873 * will proceed to copy it. See explanation for this 1874 * routine as to why only a single snapshot needs to 1875 * claim this block. 1876 */ 1877 if (size == fs->fs_bsize) { 1878 #ifdef DIAGNOSTIC 1879 if (snapdebug) 1880 printf("%s %ju lbn %jd from inum %ju\n", 1881 "Grabonremove: snapino", 1882 (uintmax_t)ip->i_number, 1883 (intmax_t)lbn, (uintmax_t)inum); 1884 #endif 1885 /* 1886 * If journaling is tracking this write we must add 1887 * the work to the inode or indirect being written. 1888 */ 1889 if (wkhd != NULL) { 1890 if (lbn < UFS_NDADDR) 1891 softdep_inode_append(ip, 1892 curthread->td_ucred, wkhd); 1893 else 1894 softdep_buf_append(ibp, wkhd); 1895 } 1896 if (lbn < UFS_NDADDR) { 1897 DIP_SET(ip, i_db[lbn], bno); 1898 } else if (I_IS_UFS1(ip)) { 1899 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] = bno; 1900 bdwrite(ibp); 1901 } else { 1902 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = bno; 1903 bdwrite(ibp); 1904 } 1905 DIP_SET(ip, i_blocks, DIP(ip, i_blocks) + btodb(size)); 1906 UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE); 1907 lockmgr(vp->v_vnlock, LK_RELEASE, NULL); 1908 return (1); 1909 } 1910 if (lbn >= UFS_NDADDR) 1911 bqrelse(ibp); 1912 /* 1913 * Allocate the block into which to do the copy. Note that this 1914 * allocation will never require any additional allocations for 1915 * the snapshot inode. 1916 */ 1917 td->td_pflags |= TDP_COWINPROGRESS; 1918 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn), 1919 fs->fs_bsize, KERNCRED, 0, &cbp); 1920 td->td_pflags &= ~TDP_COWINPROGRESS; 1921 if (error) 1922 break; 1923 #ifdef DIAGNOSTIC 1924 if (snapdebug) 1925 printf("%s%ju lbn %jd %s %ju size %ld to blkno %jd\n", 1926 "Copyonremove: snapino ", (uintmax_t)ip->i_number, 1927 (intmax_t)lbn, "for inum", (uintmax_t)inum, size, 1928 (intmax_t)cbp->b_blkno); 1929 #endif 1930 /* 1931 * If we have already read the old block contents, then 1932 * simply copy them to the new block. Note that we need 1933 * to synchronously write snapshots that have not been 1934 * unlinked, and hence will be visible after a crash, 1935 * to ensure their integrity. At a minimum we ensure the 1936 * integrity of the filesystem metadata, but use the 1937 * dopersistence sysctl-setable flag to decide on the 1938 * persistence needed for file content data. 1939 */ 1940 if (savedcbp != NULL) { 1941 bcopy(savedcbp->b_data, cbp->b_data, fs->fs_bsize); 1942 bawrite(cbp); 1943 if ((vtype == VDIR || dopersistence) && 1944 ip->i_effnlink > 0) 1945 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 1946 continue; 1947 } 1948 /* 1949 * Otherwise, read the old block contents into the buffer. 1950 */ 1951 if ((error = readblock(vp, cbp, lbn)) != 0) { 1952 bzero(cbp->b_data, fs->fs_bsize); 1953 bawrite(cbp); 1954 if ((vtype == VDIR || dopersistence) && 1955 ip->i_effnlink > 0) 1956 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 1957 break; 1958 } 1959 savedcbp = cbp; 1960 } 1961 /* 1962 * Note that we need to synchronously write snapshots that 1963 * have not been unlinked, and hence will be visible after 1964 * a crash, to ensure their integrity. At a minimum we 1965 * ensure the integrity of the filesystem metadata, but 1966 * use the dopersistence sysctl-setable flag to decide on 1967 * the persistence needed for file content data. 1968 */ 1969 if (savedcbp) { 1970 vp = savedcbp->b_vp; 1971 bawrite(savedcbp); 1972 if ((vtype == VDIR || dopersistence) && 1973 VTOI(vp)->i_effnlink > 0) 1974 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 1975 } 1976 /* 1977 * If we have been unable to allocate a block in which to do 1978 * the copy, then return non-zero so that the fragment will 1979 * not be freed. Although space will be lost, the snapshot 1980 * will stay consistent. 1981 */ 1982 if (error != 0 && wkhd != NULL) 1983 softdep_freework(wkhd); 1984 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 1985 return (error); 1986 } 1987 1988 /* 1989 * Associate snapshot files when mounting. 1990 */ 1991 void 1992 ffs_snapshot_mount(mp) 1993 struct mount *mp; 1994 { 1995 struct ufsmount *ump = VFSTOUFS(mp); 1996 struct vnode *devvp = ump->um_devvp; 1997 struct fs *fs = ump->um_fs; 1998 struct thread *td = curthread; 1999 struct snapdata *sn; 2000 struct vnode *vp; 2001 struct vnode *lastvp; 2002 struct inode *ip; 2003 struct uio auio; 2004 struct iovec aiov; 2005 void *snapblklist; 2006 char *reason; 2007 daddr_t snaplistsize; 2008 int error, snaploc, loc; 2009 2010 /* 2011 * XXX The following needs to be set before ffs_truncate or 2012 * VOP_READ can be called. 2013 */ 2014 mp->mnt_stat.f_iosize = fs->fs_bsize; 2015 /* 2016 * Process each snapshot listed in the superblock. 2017 */ 2018 vp = NULL; 2019 lastvp = NULL; 2020 sn = NULL; 2021 for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++) { 2022 if (fs->fs_snapinum[snaploc] == 0) 2023 break; 2024 if ((error = ffs_vget(mp, fs->fs_snapinum[snaploc], 2025 LK_EXCLUSIVE, &vp)) != 0){ 2026 printf("ffs_snapshot_mount: vget failed %d\n", error); 2027 continue; 2028 } 2029 ip = VTOI(vp); 2030 if (vp->v_type != VREG) { 2031 reason = "non-file snapshot"; 2032 } else if (!IS_SNAPSHOT(ip)) { 2033 reason = "non-snapshot"; 2034 } else if (ip->i_size == 2035 lblktosize(fs, howmany(fs->fs_size, fs->fs_frag))) { 2036 reason = "old format snapshot"; 2037 (void)ffs_truncate(vp, (off_t)0, 0, NOCRED); 2038 (void)ffs_syncvnode(vp, MNT_WAIT, 0); 2039 } else { 2040 reason = NULL; 2041 } 2042 if (reason != NULL) { 2043 printf("ffs_snapshot_mount: %s inode %d\n", 2044 reason, fs->fs_snapinum[snaploc]); 2045 vput(vp); 2046 vp = NULL; 2047 for (loc = snaploc + 1; loc < FSMAXSNAP; loc++) { 2048 if (fs->fs_snapinum[loc] == 0) 2049 break; 2050 fs->fs_snapinum[loc - 1] = fs->fs_snapinum[loc]; 2051 } 2052 fs->fs_snapinum[loc - 1] = 0; 2053 snaploc--; 2054 continue; 2055 } 2056 /* 2057 * Acquire a lock on the snapdata structure, creating it if 2058 * necessary. 2059 */ 2060 sn = ffs_snapdata_acquire(devvp); 2061 /* 2062 * Change vnode to use shared snapshot lock instead of the 2063 * original private lock. 2064 */ 2065 vp->v_vnlock = &sn->sn_lock; 2066 lockmgr(&vp->v_lock, LK_RELEASE, NULL); 2067 /* 2068 * Link it onto the active snapshot list. 2069 */ 2070 VI_LOCK(devvp); 2071 if (ip->i_nextsnap.tqe_prev != 0) 2072 panic("ffs_snapshot_mount: %ju already on list", 2073 (uintmax_t)ip->i_number); 2074 else 2075 TAILQ_INSERT_TAIL(&sn->sn_head, ip, i_nextsnap); 2076 vp->v_vflag |= VV_SYSTEM; 2077 VI_UNLOCK(devvp); 2078 VOP_UNLOCK(vp); 2079 lastvp = vp; 2080 } 2081 vp = lastvp; 2082 /* 2083 * No usable snapshots found. 2084 */ 2085 if (sn == NULL || vp == NULL) 2086 return; 2087 /* 2088 * Allocate the space for the block hints list. We always want to 2089 * use the list from the newest snapshot. 2090 */ 2091 auio.uio_iov = &aiov; 2092 auio.uio_iovcnt = 1; 2093 aiov.iov_base = (void *)&snaplistsize; 2094 aiov.iov_len = sizeof(snaplistsize); 2095 auio.uio_resid = aiov.iov_len; 2096 auio.uio_offset = 2097 lblktosize(fs, howmany(fs->fs_size, fs->fs_frag)); 2098 auio.uio_segflg = UIO_SYSSPACE; 2099 auio.uio_rw = UIO_READ; 2100 auio.uio_td = td; 2101 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2102 if ((error = VOP_READ(vp, &auio, IO_UNIT, td->td_ucred)) != 0) { 2103 printf("ffs_snapshot_mount: read_1 failed %d\n", error); 2104 VOP_UNLOCK(vp); 2105 return; 2106 } 2107 snapblklist = malloc(snaplistsize * sizeof(daddr_t), 2108 M_UFSMNT, M_WAITOK); 2109 auio.uio_iovcnt = 1; 2110 aiov.iov_base = snapblklist; 2111 aiov.iov_len = snaplistsize * sizeof (daddr_t); 2112 auio.uio_resid = aiov.iov_len; 2113 auio.uio_offset -= sizeof(snaplistsize); 2114 if ((error = VOP_READ(vp, &auio, IO_UNIT, td->td_ucred)) != 0) { 2115 printf("ffs_snapshot_mount: read_2 failed %d\n", error); 2116 VOP_UNLOCK(vp); 2117 free(snapblklist, M_UFSMNT); 2118 return; 2119 } 2120 VOP_UNLOCK(vp); 2121 VI_LOCK(devvp); 2122 ASSERT_VOP_LOCKED(devvp, "ffs_snapshot_mount"); 2123 sn->sn_listsize = snaplistsize; 2124 sn->sn_blklist = (daddr_t *)snapblklist; 2125 devvp->v_vflag |= VV_COPYONWRITE; 2126 VI_UNLOCK(devvp); 2127 } 2128 2129 /* 2130 * Disassociate snapshot files when unmounting. 2131 */ 2132 void 2133 ffs_snapshot_unmount(mp) 2134 struct mount *mp; 2135 { 2136 struct vnode *devvp = VFSTOUFS(mp)->um_devvp; 2137 struct snapdata *sn; 2138 struct inode *xp; 2139 struct vnode *vp; 2140 2141 VI_LOCK(devvp); 2142 sn = devvp->v_rdev->si_snapdata; 2143 while (sn != NULL && (xp = TAILQ_FIRST(&sn->sn_head)) != NULL) { 2144 vp = ITOV(xp); 2145 TAILQ_REMOVE(&sn->sn_head, xp, i_nextsnap); 2146 xp->i_nextsnap.tqe_prev = 0; 2147 lockmgr(&sn->sn_lock, LK_INTERLOCK | LK_EXCLUSIVE, 2148 VI_MTX(devvp)); 2149 /* 2150 * Avoid LOR with above snapshot lock. The LK_NOWAIT should 2151 * never fail as the lock is currently unused. Rather than 2152 * panic, we recover by doing the blocking lock. 2153 */ 2154 if (lockmgr(&vp->v_lock, LK_EXCLUSIVE | LK_NOWAIT, NULL) != 0) { 2155 printf("ffs_snapshot_unmount: Unexpected LK_NOWAIT " 2156 "failure\n"); 2157 lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL); 2158 } 2159 KASSERT(vp->v_vnlock == &sn->sn_lock, 2160 ("ffs_snapshot_unmount: lost lock mutation")); 2161 vp->v_vnlock = &vp->v_lock; 2162 lockmgr(&vp->v_lock, LK_RELEASE, NULL); 2163 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 2164 if (xp->i_effnlink > 0) 2165 vrele(vp); 2166 VI_LOCK(devvp); 2167 sn = devvp->v_rdev->si_snapdata; 2168 } 2169 try_free_snapdata(devvp); 2170 ASSERT_VOP_LOCKED(devvp, "ffs_snapshot_unmount"); 2171 } 2172 2173 /* 2174 * Check the buffer block to be belong to device buffer that shall be 2175 * locked after snaplk. devvp shall be locked on entry, and will be 2176 * leaved locked upon exit. 2177 */ 2178 static int 2179 ffs_bp_snapblk(devvp, bp) 2180 struct vnode *devvp; 2181 struct buf *bp; 2182 { 2183 struct snapdata *sn; 2184 struct fs *fs; 2185 ufs2_daddr_t lbn, *snapblklist; 2186 int lower, upper, mid; 2187 2188 ASSERT_VI_LOCKED(devvp, "ffs_bp_snapblk"); 2189 KASSERT(devvp->v_type == VCHR, ("Not a device %p", devvp)); 2190 sn = devvp->v_rdev->si_snapdata; 2191 if (sn == NULL || TAILQ_FIRST(&sn->sn_head) == NULL) 2192 return (0); 2193 fs = ITOFS(TAILQ_FIRST(&sn->sn_head)); 2194 lbn = fragstoblks(fs, dbtofsb(fs, bp->b_blkno)); 2195 snapblklist = sn->sn_blklist; 2196 upper = sn->sn_listsize - 1; 2197 lower = 1; 2198 while (lower <= upper) { 2199 mid = (lower + upper) / 2; 2200 if (snapblklist[mid] == lbn) 2201 break; 2202 if (snapblklist[mid] < lbn) 2203 lower = mid + 1; 2204 else 2205 upper = mid - 1; 2206 } 2207 if (lower <= upper) 2208 return (1); 2209 return (0); 2210 } 2211 2212 void 2213 ffs_bdflush(bo, bp) 2214 struct bufobj *bo; 2215 struct buf *bp; 2216 { 2217 struct thread *td; 2218 struct vnode *vp, *devvp; 2219 struct buf *nbp; 2220 int bp_bdskip; 2221 2222 if (bo->bo_dirty.bv_cnt <= dirtybufthresh) 2223 return; 2224 2225 td = curthread; 2226 vp = bp->b_vp; 2227 devvp = bo2vnode(bo); 2228 KASSERT(vp == devvp, ("devvp != vp %p %p", bo, bp)); 2229 2230 VI_LOCK(devvp); 2231 bp_bdskip = ffs_bp_snapblk(devvp, bp); 2232 if (bp_bdskip) 2233 bdwriteskip++; 2234 VI_UNLOCK(devvp); 2235 if (bo->bo_dirty.bv_cnt > dirtybufthresh + 10 && !bp_bdskip) { 2236 (void) VOP_FSYNC(vp, MNT_NOWAIT, td); 2237 altbufferflushes++; 2238 } else { 2239 BO_LOCK(bo); 2240 /* 2241 * Try to find a buffer to flush. 2242 */ 2243 TAILQ_FOREACH(nbp, &bo->bo_dirty.bv_hd, b_bobufs) { 2244 if ((nbp->b_vflags & BV_BKGRDINPROG) || 2245 BUF_LOCK(nbp, 2246 LK_EXCLUSIVE | LK_NOWAIT, NULL)) 2247 continue; 2248 if (bp == nbp) 2249 panic("bdwrite: found ourselves"); 2250 BO_UNLOCK(bo); 2251 /* 2252 * Don't countdeps with the bo lock 2253 * held. 2254 */ 2255 if (buf_countdeps(nbp, 0)) { 2256 BO_LOCK(bo); 2257 BUF_UNLOCK(nbp); 2258 continue; 2259 } 2260 if (bp_bdskip) { 2261 VI_LOCK(devvp); 2262 if (!ffs_bp_snapblk(vp, nbp)) { 2263 VI_UNLOCK(devvp); 2264 BO_LOCK(bo); 2265 BUF_UNLOCK(nbp); 2266 continue; 2267 } 2268 VI_UNLOCK(devvp); 2269 } 2270 if (nbp->b_flags & B_CLUSTEROK) { 2271 vfs_bio_awrite(nbp); 2272 } else { 2273 bremfree(nbp); 2274 bawrite(nbp); 2275 } 2276 dirtybufferflushes++; 2277 break; 2278 } 2279 if (nbp == NULL) 2280 BO_UNLOCK(bo); 2281 } 2282 } 2283 2284 /* 2285 * Check for need to copy block that is about to be written, 2286 * copying the block if necessary. 2287 */ 2288 int 2289 ffs_copyonwrite(devvp, bp) 2290 struct vnode *devvp; 2291 struct buf *bp; 2292 { 2293 struct snapdata *sn; 2294 struct buf *ibp, *cbp, *savedcbp = NULL; 2295 struct thread *td = curthread; 2296 struct fs *fs; 2297 struct inode *ip; 2298 struct vnode *vp = NULL; 2299 ufs2_daddr_t lbn, blkno, *snapblklist; 2300 int lower, upper, mid, indiroff, error = 0; 2301 int launched_async_io, prev_norunningbuf; 2302 long saved_runningbufspace; 2303 2304 if (devvp != bp->b_vp && IS_SNAPSHOT(VTOI(bp->b_vp))) 2305 return (0); /* Update on a snapshot file */ 2306 if (td->td_pflags & TDP_COWINPROGRESS) 2307 panic("ffs_copyonwrite: recursive call"); 2308 /* 2309 * First check to see if it is in the preallocated list. 2310 * By doing this check we avoid several potential deadlocks. 2311 */ 2312 VI_LOCK(devvp); 2313 sn = devvp->v_rdev->si_snapdata; 2314 if (sn == NULL || 2315 TAILQ_EMPTY(&sn->sn_head)) { 2316 VI_UNLOCK(devvp); 2317 return (0); /* No snapshot */ 2318 } 2319 ip = TAILQ_FIRST(&sn->sn_head); 2320 fs = ITOFS(ip); 2321 lbn = fragstoblks(fs, dbtofsb(fs, bp->b_blkno)); 2322 if (lbn < UFS_NDADDR) { 2323 VI_UNLOCK(devvp); 2324 return (0); /* Direct blocks are always copied */ 2325 } 2326 snapblklist = sn->sn_blklist; 2327 upper = sn->sn_listsize - 1; 2328 lower = 1; 2329 while (lower <= upper) { 2330 mid = (lower + upper) / 2; 2331 if (snapblklist[mid] == lbn) 2332 break; 2333 if (snapblklist[mid] < lbn) 2334 lower = mid + 1; 2335 else 2336 upper = mid - 1; 2337 } 2338 if (lower <= upper) { 2339 VI_UNLOCK(devvp); 2340 return (0); 2341 } 2342 launched_async_io = 0; 2343 prev_norunningbuf = td->td_pflags & TDP_NORUNNINGBUF; 2344 /* 2345 * Since I/O on bp isn't yet in progress and it may be blocked 2346 * for a long time waiting on snaplk, back it out of 2347 * runningbufspace, possibly waking other threads waiting for space. 2348 */ 2349 saved_runningbufspace = bp->b_runningbufspace; 2350 if (saved_runningbufspace != 0) 2351 runningbufwakeup(bp); 2352 /* 2353 * Not in the precomputed list, so check the snapshots. 2354 */ 2355 while (lockmgr(&sn->sn_lock, LK_INTERLOCK | LK_EXCLUSIVE | LK_SLEEPFAIL, 2356 VI_MTX(devvp)) != 0) { 2357 VI_LOCK(devvp); 2358 sn = devvp->v_rdev->si_snapdata; 2359 if (sn == NULL || 2360 TAILQ_EMPTY(&sn->sn_head)) { 2361 VI_UNLOCK(devvp); 2362 if (saved_runningbufspace != 0) { 2363 bp->b_runningbufspace = saved_runningbufspace; 2364 atomic_add_long(&runningbufspace, 2365 bp->b_runningbufspace); 2366 } 2367 return (0); /* Snapshot gone */ 2368 } 2369 } 2370 TAILQ_FOREACH(ip, &sn->sn_head, i_nextsnap) { 2371 vp = ITOV(ip); 2372 if (DOINGSOFTDEP(vp)) 2373 softdep_prealloc(vp, MNT_WAIT); 2374 /* 2375 * We ensure that everything of our own that needs to be 2376 * copied will be done at the time that ffs_snapshot is 2377 * called. Thus we can skip the check here which can 2378 * deadlock in doing the lookup in UFS_BALLOC. 2379 */ 2380 if (bp->b_vp == vp) 2381 continue; 2382 /* 2383 * Check to see if block needs to be copied. We do not have 2384 * to hold the snapshot lock while doing this lookup as it 2385 * will never require any additional allocations for the 2386 * snapshot inode. 2387 */ 2388 if (lbn < UFS_NDADDR) { 2389 blkno = DIP(ip, i_db[lbn]); 2390 } else { 2391 td->td_pflags |= TDP_COWINPROGRESS | TDP_NORUNNINGBUF; 2392 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn), 2393 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 2394 td->td_pflags &= ~TDP_COWINPROGRESS; 2395 if (error) 2396 break; 2397 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs); 2398 if (I_IS_UFS1(ip)) 2399 blkno=((ufs1_daddr_t *)(ibp->b_data))[indiroff]; 2400 else 2401 blkno=((ufs2_daddr_t *)(ibp->b_data))[indiroff]; 2402 bqrelse(ibp); 2403 } 2404 #ifdef INVARIANTS 2405 if (blkno == BLK_SNAP && bp->b_lblkno >= 0) 2406 panic("ffs_copyonwrite: bad copy block"); 2407 #endif 2408 if (blkno != 0) 2409 continue; 2410 /* 2411 * Allocate the block into which to do the copy. Since 2412 * multiple processes may all try to copy the same block, 2413 * we have to recheck our need to do a copy if we sleep 2414 * waiting for the lock. 2415 * 2416 * Because all snapshots on a filesystem share a single 2417 * lock, we ensure that we will never be in competition 2418 * with another process to allocate a block. 2419 */ 2420 td->td_pflags |= TDP_COWINPROGRESS | TDP_NORUNNINGBUF; 2421 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn), 2422 fs->fs_bsize, KERNCRED, 0, &cbp); 2423 td->td_pflags &= ~TDP_COWINPROGRESS; 2424 if (error) 2425 break; 2426 #ifdef DIAGNOSTIC 2427 if (snapdebug) { 2428 printf("Copyonwrite: snapino %ju lbn %jd for ", 2429 (uintmax_t)ip->i_number, (intmax_t)lbn); 2430 if (bp->b_vp == devvp) 2431 printf("fs metadata"); 2432 else 2433 printf("inum %ju", 2434 (uintmax_t)VTOI(bp->b_vp)->i_number); 2435 printf(" lblkno %jd to blkno %jd\n", 2436 (intmax_t)bp->b_lblkno, (intmax_t)cbp->b_blkno); 2437 } 2438 #endif 2439 /* 2440 * If we have already read the old block contents, then 2441 * simply copy them to the new block. Note that we need 2442 * to synchronously write snapshots that have not been 2443 * unlinked, and hence will be visible after a crash, 2444 * to ensure their integrity. At a minimum we ensure the 2445 * integrity of the filesystem metadata, but use the 2446 * dopersistence sysctl-setable flag to decide on the 2447 * persistence needed for file content data. 2448 */ 2449 if (savedcbp != NULL) { 2450 bcopy(savedcbp->b_data, cbp->b_data, fs->fs_bsize); 2451 bawrite(cbp); 2452 if ((devvp == bp->b_vp || bp->b_vp->v_type == VDIR || 2453 dopersistence) && ip->i_effnlink > 0) 2454 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 2455 else 2456 launched_async_io = 1; 2457 continue; 2458 } 2459 /* 2460 * Otherwise, read the old block contents into the buffer. 2461 */ 2462 if ((error = readblock(vp, cbp, lbn)) != 0) { 2463 bzero(cbp->b_data, fs->fs_bsize); 2464 bawrite(cbp); 2465 if ((devvp == bp->b_vp || bp->b_vp->v_type == VDIR || 2466 dopersistence) && ip->i_effnlink > 0) 2467 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 2468 else 2469 launched_async_io = 1; 2470 break; 2471 } 2472 savedcbp = cbp; 2473 } 2474 /* 2475 * Note that we need to synchronously write snapshots that 2476 * have not been unlinked, and hence will be visible after 2477 * a crash, to ensure their integrity. At a minimum we 2478 * ensure the integrity of the filesystem metadata, but 2479 * use the dopersistence sysctl-setable flag to decide on 2480 * the persistence needed for file content data. 2481 */ 2482 if (savedcbp) { 2483 vp = savedcbp->b_vp; 2484 bawrite(savedcbp); 2485 if ((devvp == bp->b_vp || bp->b_vp->v_type == VDIR || 2486 dopersistence) && VTOI(vp)->i_effnlink > 0) 2487 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 2488 else 2489 launched_async_io = 1; 2490 } 2491 lockmgr(vp->v_vnlock, LK_RELEASE, NULL); 2492 td->td_pflags = (td->td_pflags & ~TDP_NORUNNINGBUF) | 2493 prev_norunningbuf; 2494 if (launched_async_io && (td->td_pflags & TDP_NORUNNINGBUF) == 0) 2495 waitrunningbufspace(); 2496 /* 2497 * I/O on bp will now be started, so count it in runningbufspace. 2498 */ 2499 if (saved_runningbufspace != 0) { 2500 bp->b_runningbufspace = saved_runningbufspace; 2501 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 2502 } 2503 return (error); 2504 } 2505 2506 /* 2507 * sync snapshots to force freework records waiting on snapshots to claim 2508 * blocks to free. 2509 */ 2510 void 2511 ffs_sync_snap(mp, waitfor) 2512 struct mount *mp; 2513 int waitfor; 2514 { 2515 struct snapdata *sn; 2516 struct vnode *devvp; 2517 struct vnode *vp; 2518 struct inode *ip; 2519 2520 devvp = VFSTOUFS(mp)->um_devvp; 2521 if ((devvp->v_vflag & VV_COPYONWRITE) == 0) 2522 return; 2523 for (;;) { 2524 VI_LOCK(devvp); 2525 sn = devvp->v_rdev->si_snapdata; 2526 if (sn == NULL) { 2527 VI_UNLOCK(devvp); 2528 return; 2529 } 2530 if (lockmgr(&sn->sn_lock, 2531 LK_INTERLOCK | LK_EXCLUSIVE | LK_SLEEPFAIL, 2532 VI_MTX(devvp)) == 0) 2533 break; 2534 } 2535 TAILQ_FOREACH(ip, &sn->sn_head, i_nextsnap) { 2536 vp = ITOV(ip); 2537 ffs_syncvnode(vp, waitfor, NO_INO_UPDT); 2538 } 2539 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 2540 } 2541 2542 /* 2543 * Read the specified block into the given buffer. 2544 * Much of this boiler-plate comes from bwrite(). 2545 */ 2546 static int 2547 readblock(vp, bp, lbn) 2548 struct vnode *vp; 2549 struct buf *bp; 2550 ufs2_daddr_t lbn; 2551 { 2552 struct inode *ip; 2553 struct bio *bip; 2554 struct fs *fs; 2555 2556 ip = VTOI(vp); 2557 fs = ITOFS(ip); 2558 2559 bip = g_alloc_bio(); 2560 bip->bio_cmd = BIO_READ; 2561 bip->bio_offset = dbtob(fsbtodb(fs, blkstofrags(fs, lbn))); 2562 bip->bio_data = bp->b_data; 2563 bip->bio_length = bp->b_bcount; 2564 bip->bio_done = NULL; 2565 2566 g_io_request(bip, ITODEVVP(ip)->v_bufobj.bo_private); 2567 bp->b_error = biowait(bip, "snaprdb"); 2568 g_destroy_bio(bip); 2569 return (bp->b_error); 2570 } 2571 2572 #endif 2573 2574 /* 2575 * Process file deletes that were deferred by ufs_inactive() due to 2576 * the file system being suspended. Transfer IN_LAZYACCESS into 2577 * IN_MODIFIED for vnodes that were accessed during suspension. 2578 */ 2579 void 2580 process_deferred_inactive(struct mount *mp) 2581 { 2582 struct vnode *vp, *mvp; 2583 struct inode *ip; 2584 int error; 2585 2586 (void) vn_start_secondary_write(NULL, &mp, V_WAIT); 2587 loop: 2588 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 2589 /* 2590 * IN_LAZYACCESS is checked here without holding any 2591 * vnode lock, but this flag is set only while holding 2592 * vnode interlock. 2593 */ 2594 if (vp->v_type == VNON || 2595 ((VTOI(vp)->i_flag & IN_LAZYACCESS) == 0 && 2596 ((vp->v_iflag & VI_OWEINACT) == 0 || vp->v_usecount > 0))) { 2597 VI_UNLOCK(vp); 2598 continue; 2599 } 2600 vholdl(vp); 2601 retry_vnode: 2602 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 2603 if (error != 0) { 2604 vdrop(vp); 2605 if (error == ENOENT) 2606 continue; /* vnode recycled */ 2607 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 2608 goto loop; 2609 } 2610 ip = VTOI(vp); 2611 if ((ip->i_flag & IN_LAZYACCESS) != 0) { 2612 ip->i_flag &= ~IN_LAZYACCESS; 2613 UFS_INODE_SET_FLAG(ip, IN_MODIFIED); 2614 } 2615 VI_LOCK(vp); 2616 error = vinactive(vp); 2617 if (error == ERELOOKUP && vp->v_usecount == 0) { 2618 VI_UNLOCK(vp); 2619 VOP_UNLOCK(vp); 2620 goto retry_vnode; 2621 } 2622 VI_UNLOCK(vp); 2623 VOP_UNLOCK(vp); 2624 vdrop(vp); 2625 } 2626 vn_finished_secondary_write(mp); 2627 } 2628 2629 #ifndef NO_FFS_SNAPSHOT 2630 2631 static struct snapdata * 2632 ffs_snapdata_alloc(void) 2633 { 2634 struct snapdata *sn; 2635 2636 /* 2637 * Fetch a snapdata from the free list if there is one available. 2638 */ 2639 mtx_lock(&snapfree_lock); 2640 sn = LIST_FIRST(&snapfree); 2641 if (sn != NULL) 2642 LIST_REMOVE(sn, sn_link); 2643 mtx_unlock(&snapfree_lock); 2644 if (sn != NULL) 2645 return (sn); 2646 /* 2647 * If there were no free snapdatas allocate one. 2648 */ 2649 sn = malloc(sizeof *sn, M_UFSMNT, M_WAITOK | M_ZERO); 2650 TAILQ_INIT(&sn->sn_head); 2651 lockinit(&sn->sn_lock, PVFS, "snaplk", VLKTIMEOUT, 2652 LK_CANRECURSE | LK_NOSHARE); 2653 return (sn); 2654 } 2655 2656 /* 2657 * The snapdata is never freed because we can not be certain that 2658 * there are no threads sleeping on the snap lock. Persisting 2659 * them permanently avoids costly synchronization in ffs_lock(). 2660 */ 2661 static void 2662 ffs_snapdata_free(struct snapdata *sn) 2663 { 2664 mtx_lock(&snapfree_lock); 2665 LIST_INSERT_HEAD(&snapfree, sn, sn_link); 2666 mtx_unlock(&snapfree_lock); 2667 } 2668 2669 /* Try to free snapdata associated with devvp */ 2670 static void 2671 try_free_snapdata(struct vnode *devvp) 2672 { 2673 struct snapdata *sn; 2674 ufs2_daddr_t *snapblklist; 2675 2676 ASSERT_VI_LOCKED(devvp, "try_free_snapdata"); 2677 sn = devvp->v_rdev->si_snapdata; 2678 2679 if (sn == NULL || TAILQ_FIRST(&sn->sn_head) != NULL || 2680 (devvp->v_vflag & VV_COPYONWRITE) == 0) { 2681 VI_UNLOCK(devvp); 2682 return; 2683 } 2684 2685 devvp->v_rdev->si_snapdata = NULL; 2686 devvp->v_vflag &= ~VV_COPYONWRITE; 2687 lockmgr(&sn->sn_lock, LK_DRAIN|LK_INTERLOCK, VI_MTX(devvp)); 2688 snapblklist = sn->sn_blklist; 2689 sn->sn_blklist = NULL; 2690 sn->sn_listsize = 0; 2691 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 2692 if (snapblklist != NULL) 2693 free(snapblklist, M_UFSMNT); 2694 ffs_snapdata_free(sn); 2695 } 2696 2697 static struct snapdata * 2698 ffs_snapdata_acquire(struct vnode *devvp) 2699 { 2700 struct snapdata *nsn, *sn; 2701 int error; 2702 2703 /* 2704 * Allocate a free snapdata. This is done before acquiring the 2705 * devvp lock to avoid allocation while the devvp interlock is 2706 * held. 2707 */ 2708 nsn = ffs_snapdata_alloc(); 2709 2710 for (;;) { 2711 VI_LOCK(devvp); 2712 sn = devvp->v_rdev->si_snapdata; 2713 if (sn == NULL) { 2714 /* 2715 * This is the first snapshot on this 2716 * filesystem and we use our pre-allocated 2717 * snapdata. Publish sn with the sn_lock 2718 * owned by us, to avoid the race. 2719 */ 2720 error = lockmgr(&nsn->sn_lock, LK_EXCLUSIVE | 2721 LK_NOWAIT, NULL); 2722 if (error != 0) 2723 panic("leaked sn, lockmgr error %d", error); 2724 sn = devvp->v_rdev->si_snapdata = nsn; 2725 VI_UNLOCK(devvp); 2726 nsn = NULL; 2727 break; 2728 } 2729 2730 /* 2731 * There is a snapshots which already exists on this 2732 * filesystem, grab a reference to the common lock. 2733 */ 2734 error = lockmgr(&sn->sn_lock, LK_INTERLOCK | 2735 LK_EXCLUSIVE | LK_SLEEPFAIL, VI_MTX(devvp)); 2736 if (error == 0) 2737 break; 2738 } 2739 2740 /* 2741 * Free any unused snapdata. 2742 */ 2743 if (nsn != NULL) 2744 ffs_snapdata_free(nsn); 2745 2746 return (sn); 2747 } 2748 2749 #endif 2750