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 VOP_UNLOCK(nd.ni_dvp); 300 if (error) { 301 NDFREE(&nd, NDF_ONLY_PNBUF); 302 vn_finished_write(wrtmp); 303 vrele(nd.ni_dvp); 304 if (error == ERELOOKUP) 305 goto restart; 306 return (error); 307 } 308 vp = nd.ni_vp; 309 vnode_create_vobject(nd.ni_vp, fs->fs_size, td); 310 vp->v_vflag |= VV_SYSTEM; 311 ip = VTOI(vp); 312 devvp = ITODEVVP(ip); 313 /* 314 * Allocate and copy the last block contents so as to be able 315 * to set size to that of the filesystem. 316 */ 317 numblks = howmany(fs->fs_size, fs->fs_frag); 318 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(numblks - 1)), 319 fs->fs_bsize, KERNCRED, BA_CLRBUF, &bp); 320 if (error) 321 goto out; 322 ip->i_size = lblktosize(fs, (off_t)numblks); 323 DIP_SET(ip, i_size, ip->i_size); 324 UFS_INODE_SET_FLAG(ip, IN_SIZEMOD | IN_CHANGE | IN_UPDATE); 325 error = readblock(vp, bp, numblks - 1); 326 bawrite(bp); 327 if (error != 0) 328 goto out; 329 /* 330 * Preallocate critical data structures so that we can copy 331 * them in without further allocation after we suspend all 332 * operations on the filesystem. We would like to just release 333 * the allocated buffers without writing them since they will 334 * be filled in below once we are ready to go, but this upsets 335 * the soft update code, so we go ahead and write the new buffers. 336 * 337 * Allocate all indirect blocks and mark all of them as not 338 * needing to be copied. 339 */ 340 for (blkno = UFS_NDADDR; blkno < numblks; blkno += NINDIR(fs)) { 341 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)blkno), 342 fs->fs_bsize, td->td_ucred, BA_METAONLY, &ibp); 343 if (error) 344 goto out; 345 bawrite(ibp); 346 } 347 /* 348 * Allocate copies for the superblock and its summary information. 349 */ 350 error = UFS_BALLOC(vp, fs->fs_sblockloc, fs->fs_sbsize, KERNCRED, 351 0, &nbp); 352 if (error) 353 goto out; 354 bawrite(nbp); 355 blkno = fragstoblks(fs, fs->fs_csaddr); 356 len = howmany(fs->fs_cssize, fs->fs_bsize); 357 for (loc = 0; loc < len; loc++) { 358 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(blkno + loc)), 359 fs->fs_bsize, KERNCRED, 0, &nbp); 360 if (error) 361 goto out; 362 bawrite(nbp); 363 } 364 /* 365 * Allocate all cylinder group blocks. 366 */ 367 for (cg = 0; cg < fs->fs_ncg; cg++) { 368 error = UFS_BALLOC(vp, lfragtosize(fs, cgtod(fs, cg)), 369 fs->fs_bsize, KERNCRED, 0, &nbp); 370 if (error) 371 goto out; 372 bawrite(nbp); 373 if (cg % 10 == 0) { 374 error = ffs_syncvnode(vp, MNT_WAIT, 0); 375 /* vp possibly reclaimed if unlocked */ 376 if (error != 0) 377 goto out; 378 } 379 } 380 /* 381 * Copy all the cylinder group maps. Although the 382 * filesystem is still active, we hope that only a few 383 * cylinder groups will change between now and when we 384 * suspend operations. Thus, we will be able to quickly 385 * touch up the few cylinder groups that changed during 386 * the suspension period. 387 */ 388 len = howmany(fs->fs_ncg, NBBY); 389 space = malloc(len, M_DEVBUF, M_WAITOK|M_ZERO); 390 UFS_LOCK(ump); 391 fs->fs_active = space; 392 UFS_UNLOCK(ump); 393 for (cg = 0; cg < fs->fs_ncg; cg++) { 394 error = UFS_BALLOC(vp, lfragtosize(fs, cgtod(fs, cg)), 395 fs->fs_bsize, KERNCRED, 0, &nbp); 396 if (error) 397 goto out; 398 error = cgaccount(cg, vp, nbp, 1); 399 bawrite(nbp); 400 if (cg % 10 == 0 && error == 0) 401 error = ffs_syncvnode(vp, MNT_WAIT, 0); 402 if (error) 403 goto out; 404 } 405 /* 406 * Change inode to snapshot type file. 407 */ 408 ip->i_flags |= SF_SNAPSHOT; 409 DIP_SET(ip, i_flags, ip->i_flags); 410 UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE); 411 /* 412 * Ensure that the snapshot is completely on disk. 413 * Since we have marked it as a snapshot it is safe to 414 * unlock it as no process will be allowed to write to it. 415 */ 416 if ((error = ffs_syncvnode(vp, MNT_WAIT, 0)) != 0) 417 goto out; 418 VOP_UNLOCK(vp); 419 /* 420 * All allocations are done, so we can now snapshot the system. 421 * 422 * Recind nice scheduling while running with the filesystem suspended. 423 */ 424 if (td->td_proc->p_nice > 0) { 425 struct proc *p; 426 427 p = td->td_proc; 428 PROC_LOCK(p); 429 saved_nice = p->p_nice; 430 sched_nice(p, 0); 431 PROC_UNLOCK(p); 432 } 433 /* 434 * Suspend operation on filesystem. 435 */ 436 for (;;) { 437 vn_finished_write(wrtmp); 438 if ((error = vfs_write_suspend(vp->v_mount, 0)) != 0) { 439 vn_start_write(NULL, &wrtmp, V_WAIT); 440 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 441 goto out; 442 } 443 if (mp->mnt_kern_flag & MNTK_SUSPENDED) 444 break; 445 vn_start_write(NULL, &wrtmp, V_WAIT); 446 } 447 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 448 if (ip->i_effnlink == 0) { 449 error = ENOENT; /* Snapshot file unlinked */ 450 goto out1; 451 } 452 #ifdef DIAGNOSTIC 453 if (collectsnapstats) 454 nanotime(&starttime); 455 #endif 456 457 /* The last block might have changed. Copy it again to be sure. */ 458 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(numblks - 1)), 459 fs->fs_bsize, KERNCRED, BA_CLRBUF, &bp); 460 if (error != 0) 461 goto out1; 462 error = readblock(vp, bp, numblks - 1); 463 bp->b_flags |= B_VALIDSUSPWRT; 464 bawrite(bp); 465 if (error != 0) 466 goto out1; 467 /* 468 * First, copy all the cylinder group maps that have changed. 469 */ 470 for (cg = 0; cg < fs->fs_ncg; cg++) { 471 if ((ACTIVECGNUM(fs, cg) & ACTIVECGOFF(cg)) != 0) 472 continue; 473 redo++; 474 error = UFS_BALLOC(vp, lfragtosize(fs, cgtod(fs, cg)), 475 fs->fs_bsize, KERNCRED, 0, &nbp); 476 if (error) 477 goto out1; 478 error = cgaccount(cg, vp, nbp, 2); 479 bawrite(nbp); 480 if (error) 481 goto out1; 482 } 483 /* 484 * Grab a copy of the superblock and its summary information. 485 * We delay writing it until the suspension is released below. 486 */ 487 copy_fs = malloc((u_long)fs->fs_bsize, M_UFSMNT, M_WAITOK); 488 bcopy(fs, copy_fs, fs->fs_sbsize); 489 copy_fs->fs_si = malloc(sizeof(struct fs_summary_info), M_UFSMNT, 490 M_ZERO | M_WAITOK); 491 if ((fs->fs_flags & (FS_UNCLEAN | FS_NEEDSFSCK)) == 0) 492 copy_fs->fs_clean = 1; 493 size = fs->fs_bsize < SBLOCKSIZE ? fs->fs_bsize : SBLOCKSIZE; 494 if (fs->fs_sbsize < size) 495 bzero(&((char *)copy_fs)[fs->fs_sbsize], 496 size - fs->fs_sbsize); 497 size = blkroundup(fs, fs->fs_cssize); 498 if (fs->fs_contigsumsize > 0) 499 size += fs->fs_ncg * sizeof(int32_t); 500 space = malloc((u_long)size, M_UFSMNT, M_WAITOK); 501 copy_fs->fs_csp = space; 502 bcopy(fs->fs_csp, copy_fs->fs_csp, fs->fs_cssize); 503 space = (char *)space + fs->fs_cssize; 504 loc = howmany(fs->fs_cssize, fs->fs_fsize); 505 i = fs->fs_frag - loc % fs->fs_frag; 506 len = (i == fs->fs_frag) ? 0 : i * fs->fs_fsize; 507 if (len > 0) { 508 if ((error = bread(devvp, fsbtodb(fs, fs->fs_csaddr + loc), 509 len, KERNCRED, &bp)) != 0) { 510 brelse(bp); 511 free(copy_fs->fs_csp, M_UFSMNT); 512 free(copy_fs->fs_si, M_UFSMNT); 513 free(copy_fs, M_UFSMNT); 514 copy_fs = NULL; 515 goto out1; 516 } 517 bcopy(bp->b_data, space, (u_int)len); 518 space = (char *)space + len; 519 bp->b_flags |= B_INVAL | B_NOCACHE; 520 brelse(bp); 521 } 522 if (fs->fs_contigsumsize > 0) { 523 copy_fs->fs_maxcluster = lp = space; 524 for (i = 0; i < fs->fs_ncg; i++) 525 *lp++ = fs->fs_contigsumsize; 526 } 527 /* 528 * We must check for active files that have been unlinked 529 * (e.g., with a zero link count). We have to expunge all 530 * trace of these files from the snapshot so that they are 531 * not reclaimed prematurely by fsck or unnecessarily dumped. 532 * We turn off the MNTK_SUSPENDED flag to avoid a panic from 533 * spec_strategy about writing on a suspended filesystem. 534 * Note that we skip unlinked snapshot files as they will 535 * be handled separately below. 536 * 537 * We also calculate the needed size for the snapshot list. 538 */ 539 snaplistsize = fs->fs_ncg + howmany(fs->fs_cssize, fs->fs_bsize) + 540 FSMAXSNAP + 1 /* superblock */ + 1 /* last block */ + 1 /* size */; 541 MNT_ILOCK(mp); 542 mp->mnt_kern_flag &= ~MNTK_SUSPENDED; 543 MNT_IUNLOCK(mp); 544 loop: 545 MNT_VNODE_FOREACH_ALL(xvp, mp, mvp) { 546 if ((xvp->v_usecount == 0 && 547 (xvp->v_iflag & (VI_OWEINACT | VI_DOINGINACT)) == 0) || 548 xvp->v_type == VNON || 549 IS_SNAPSHOT(VTOI(xvp))) { 550 VI_UNLOCK(xvp); 551 continue; 552 } 553 /* 554 * We can skip parent directory vnode because it must have 555 * this snapshot file in it. 556 */ 557 if (xvp == nd.ni_dvp) { 558 VI_UNLOCK(xvp); 559 continue; 560 } 561 vholdl(xvp); 562 if (vn_lock(xvp, LK_EXCLUSIVE | LK_INTERLOCK) != 0) { 563 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 564 vdrop(xvp); 565 goto loop; 566 } 567 VI_LOCK(xvp); 568 if (xvp->v_usecount == 0 && 569 (xvp->v_iflag & (VI_OWEINACT | VI_DOINGINACT)) == 0) { 570 VI_UNLOCK(xvp); 571 VOP_UNLOCK(xvp); 572 vdrop(xvp); 573 continue; 574 } 575 VI_UNLOCK(xvp); 576 #ifdef DIAGNOSTIC 577 if (snapdebug) 578 vn_printf(xvp, "ffs_snapshot: busy vnode "); 579 #endif 580 if (VOP_GETATTR(xvp, &vat, td->td_ucred) == 0 && 581 vat.va_nlink > 0) { 582 VOP_UNLOCK(xvp); 583 vdrop(xvp); 584 continue; 585 } 586 xp = VTOI(xvp); 587 if (ffs_checkfreefile(copy_fs, vp, xp->i_number)) { 588 VOP_UNLOCK(xvp); 589 vdrop(xvp); 590 continue; 591 } 592 /* 593 * If there is a fragment, clear it here. 594 */ 595 blkno = 0; 596 loc = howmany(xp->i_size, fs->fs_bsize) - 1; 597 if (loc < UFS_NDADDR) { 598 len = fragroundup(fs, blkoff(fs, xp->i_size)); 599 if (len != 0 && len < fs->fs_bsize) { 600 ffs_blkfree(ump, copy_fs, vp, 601 DIP(xp, i_db[loc]), len, xp->i_number, 602 xvp->v_type, NULL, SINGLETON_KEY); 603 blkno = DIP(xp, i_db[loc]); 604 DIP_SET(xp, i_db[loc], 0); 605 } 606 } 607 snaplistsize += 1; 608 if (I_IS_UFS1(xp)) 609 error = expunge_ufs1(vp, xp, copy_fs, fullacct_ufs1, 610 BLK_NOCOPY, 1); 611 else 612 error = expunge_ufs2(vp, xp, copy_fs, fullacct_ufs2, 613 BLK_NOCOPY, 1); 614 if (blkno) 615 DIP_SET(xp, i_db[loc], blkno); 616 if (!error) 617 error = ffs_freefile(ump, copy_fs, vp, xp->i_number, 618 xp->i_mode, NULL); 619 VOP_UNLOCK(xvp); 620 vdrop(xvp); 621 if (error) { 622 free(copy_fs->fs_csp, M_UFSMNT); 623 free(copy_fs->fs_si, M_UFSMNT); 624 free(copy_fs, M_UFSMNT); 625 copy_fs = NULL; 626 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 627 goto out1; 628 } 629 } 630 /* 631 * Erase the journal file from the snapshot. 632 */ 633 if (fs->fs_flags & FS_SUJ) { 634 error = softdep_journal_lookup(mp, &xvp); 635 if (error) { 636 free(copy_fs->fs_csp, M_UFSMNT); 637 free(copy_fs->fs_si, M_UFSMNT); 638 free(copy_fs, M_UFSMNT); 639 copy_fs = NULL; 640 goto out1; 641 } 642 xp = VTOI(xvp); 643 if (I_IS_UFS1(xp)) 644 error = expunge_ufs1(vp, xp, copy_fs, fullacct_ufs1, 645 BLK_NOCOPY, 0); 646 else 647 error = expunge_ufs2(vp, xp, copy_fs, fullacct_ufs2, 648 BLK_NOCOPY, 0); 649 vput(xvp); 650 } 651 /* 652 * Acquire a lock on the snapdata structure, creating it if necessary. 653 */ 654 sn = ffs_snapdata_acquire(devvp); 655 /* 656 * Change vnode to use shared snapshot lock instead of the original 657 * private lock. 658 */ 659 vp->v_vnlock = &sn->sn_lock; 660 lockmgr(&vp->v_lock, LK_RELEASE, NULL); 661 xp = TAILQ_FIRST(&sn->sn_head); 662 /* 663 * If this is the first snapshot on this filesystem, then we need 664 * to allocate the space for the list of preallocated snapshot blocks. 665 * This list will be refined below, but this preliminary one will 666 * keep us out of deadlock until the full one is ready. 667 */ 668 if (xp == NULL) { 669 snapblklist = malloc(snaplistsize * sizeof(daddr_t), 670 M_UFSMNT, M_WAITOK); 671 blkp = &snapblklist[1]; 672 *blkp++ = lblkno(fs, fs->fs_sblockloc); 673 blkno = fragstoblks(fs, fs->fs_csaddr); 674 for (cg = 0; cg < fs->fs_ncg; cg++) { 675 if (fragstoblks(fs, cgtod(fs, cg) > blkno)) 676 break; 677 *blkp++ = fragstoblks(fs, cgtod(fs, cg)); 678 } 679 len = howmany(fs->fs_cssize, fs->fs_bsize); 680 for (loc = 0; loc < len; loc++) 681 *blkp++ = blkno + loc; 682 for (; cg < fs->fs_ncg; cg++) 683 *blkp++ = fragstoblks(fs, cgtod(fs, cg)); 684 snapblklist[0] = blkp - snapblklist; 685 VI_LOCK(devvp); 686 if (sn->sn_blklist != NULL) 687 panic("ffs_snapshot: non-empty list"); 688 sn->sn_blklist = snapblklist; 689 sn->sn_listsize = blkp - snapblklist; 690 VI_UNLOCK(devvp); 691 } 692 /* 693 * Record snapshot inode. Since this is the newest snapshot, 694 * it must be placed at the end of the list. 695 */ 696 VI_LOCK(devvp); 697 fs->fs_snapinum[snaploc] = ip->i_number; 698 if (ip->i_nextsnap.tqe_prev != 0) 699 panic("ffs_snapshot: %ju already on list", 700 (uintmax_t)ip->i_number); 701 TAILQ_INSERT_TAIL(&sn->sn_head, ip, i_nextsnap); 702 devvp->v_vflag |= VV_COPYONWRITE; 703 VI_UNLOCK(devvp); 704 ASSERT_VOP_LOCKED(vp, "ffs_snapshot vp"); 705 out1: 706 KASSERT((sn != NULL && copy_fs != NULL && error == 0) || 707 (sn == NULL && copy_fs == NULL && error != 0), 708 ("email phk@ and mckusick@")); 709 /* 710 * Resume operation on filesystem. 711 */ 712 vfs_write_resume(vp->v_mount, VR_START_WRITE | VR_NO_SUSPCLR); 713 #ifdef DIAGNOSTIC 714 if (collectsnapstats && starttime.tv_sec > 0) { 715 nanotime(&endtime); 716 timespecsub(&endtime, &starttime, &endtime); 717 printf("%s: suspended %ld.%03ld sec, redo %ld of %d\n", 718 vp->v_mount->mnt_stat.f_mntonname, (long)endtime.tv_sec, 719 endtime.tv_nsec / 1000000, redo, fs->fs_ncg); 720 } 721 #endif 722 if (copy_fs == NULL) 723 goto out; 724 /* 725 * Copy allocation information from all the snapshots in 726 * this snapshot and then expunge them from its view. 727 */ 728 TAILQ_FOREACH(xp, &sn->sn_head, i_nextsnap) { 729 if (xp == ip) 730 break; 731 if (I_IS_UFS1(xp)) 732 error = expunge_ufs1(vp, xp, fs, snapacct_ufs1, 733 BLK_SNAP, 0); 734 else 735 error = expunge_ufs2(vp, xp, fs, snapacct_ufs2, 736 BLK_SNAP, 0); 737 if (error == 0 && xp->i_effnlink == 0) { 738 error = ffs_freefile(ump, 739 copy_fs, 740 vp, 741 xp->i_number, 742 xp->i_mode, NULL); 743 } 744 if (error) { 745 fs->fs_snapinum[snaploc] = 0; 746 goto done; 747 } 748 } 749 /* 750 * Allocate space for the full list of preallocated snapshot blocks. 751 */ 752 snapblklist = malloc(snaplistsize * sizeof(daddr_t), 753 M_UFSMNT, M_WAITOK); 754 ip->i_snapblklist = &snapblklist[1]; 755 /* 756 * Expunge the blocks used by the snapshots from the set of 757 * blocks marked as used in the snapshot bitmaps. Also, collect 758 * the list of allocated blocks in i_snapblklist. 759 */ 760 if (I_IS_UFS1(ip)) 761 error = expunge_ufs1(vp, ip, copy_fs, mapacct_ufs1, 762 BLK_SNAP, 0); 763 else 764 error = expunge_ufs2(vp, ip, copy_fs, mapacct_ufs2, 765 BLK_SNAP, 0); 766 if (error) { 767 fs->fs_snapinum[snaploc] = 0; 768 free(snapblklist, M_UFSMNT); 769 goto done; 770 } 771 if (snaplistsize < ip->i_snapblklist - snapblklist) 772 panic("ffs_snapshot: list too small"); 773 snaplistsize = ip->i_snapblklist - snapblklist; 774 snapblklist[0] = snaplistsize; 775 ip->i_snapblklist = 0; 776 /* 777 * Write out the list of allocated blocks to the end of the snapshot. 778 */ 779 auio.uio_iov = &aiov; 780 auio.uio_iovcnt = 1; 781 aiov.iov_base = (void *)snapblklist; 782 aiov.iov_len = snaplistsize * sizeof(daddr_t); 783 auio.uio_resid = aiov.iov_len; 784 auio.uio_offset = ip->i_size; 785 auio.uio_segflg = UIO_SYSSPACE; 786 auio.uio_rw = UIO_WRITE; 787 auio.uio_td = td; 788 if ((error = VOP_WRITE(vp, &auio, IO_UNIT, td->td_ucred)) != 0) { 789 fs->fs_snapinum[snaploc] = 0; 790 free(snapblklist, M_UFSMNT); 791 goto done; 792 } 793 /* 794 * Write the superblock and its summary information 795 * to the snapshot. 796 */ 797 blkno = fragstoblks(fs, fs->fs_csaddr); 798 len = howmany(fs->fs_cssize, fs->fs_bsize); 799 space = copy_fs->fs_csp; 800 for (loc = 0; loc < len; loc++) { 801 error = bread(vp, blkno + loc, fs->fs_bsize, KERNCRED, &nbp); 802 if (error) { 803 fs->fs_snapinum[snaploc] = 0; 804 free(snapblklist, M_UFSMNT); 805 goto done; 806 } 807 bcopy(space, nbp->b_data, fs->fs_bsize); 808 space = (char *)space + fs->fs_bsize; 809 bawrite(nbp); 810 } 811 error = bread(vp, lblkno(fs, fs->fs_sblockloc), fs->fs_bsize, 812 KERNCRED, &nbp); 813 if (error) { 814 brelse(nbp); 815 } else { 816 loc = blkoff(fs, fs->fs_sblockloc); 817 copy_fs->fs_fmod = 0; 818 copy_fs->fs_ckhash = ffs_calc_sbhash(copy_fs); 819 bcopy((char *)copy_fs, &nbp->b_data[loc], (u_int)fs->fs_sbsize); 820 bawrite(nbp); 821 } 822 /* 823 * As this is the newest list, it is the most inclusive, so 824 * should replace the previous list. 825 */ 826 VI_LOCK(devvp); 827 space = sn->sn_blklist; 828 sn->sn_blklist = snapblklist; 829 sn->sn_listsize = snaplistsize; 830 VI_UNLOCK(devvp); 831 if (space != NULL) 832 free(space, M_UFSMNT); 833 /* 834 * Preallocate all the direct blocks in the snapshot inode so 835 * that we never have to write the inode itself to commit an 836 * update to the contents of the snapshot. Note that once 837 * created, the size of the snapshot will never change, so 838 * there will never be a need to write the inode except to 839 * update the non-integrity-critical time fields and 840 * allocated-block count. 841 */ 842 for (blockno = 0; blockno < UFS_NDADDR; blockno++) { 843 if (DIP(ip, i_db[blockno]) != 0) 844 continue; 845 error = UFS_BALLOC(vp, lblktosize(fs, blockno), 846 fs->fs_bsize, KERNCRED, BA_CLRBUF, &bp); 847 if (error) 848 break; 849 error = readblock(vp, bp, blockno); 850 bawrite(bp); 851 if (error != 0) 852 break; 853 } 854 done: 855 free(copy_fs->fs_csp, M_UFSMNT); 856 free(copy_fs->fs_si, M_UFSMNT); 857 free(copy_fs, M_UFSMNT); 858 copy_fs = NULL; 859 out: 860 NDFREE(&nd, NDF_ONLY_PNBUF); 861 if (saved_nice > 0) { 862 struct proc *p; 863 864 p = td->td_proc; 865 PROC_LOCK(p); 866 sched_nice(td->td_proc, saved_nice); 867 PROC_UNLOCK(td->td_proc); 868 } 869 UFS_LOCK(ump); 870 if (fs->fs_active != 0) { 871 free(fs->fs_active, M_DEVBUF); 872 fs->fs_active = 0; 873 } 874 UFS_UNLOCK(ump); 875 MNT_ILOCK(mp); 876 mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | (flag & ~MNT_QUOTA); 877 MNT_IUNLOCK(mp); 878 if (error) 879 (void) ffs_truncate(vp, (off_t)0, 0, NOCRED); 880 (void) ffs_syncvnode(vp, MNT_WAIT, 0); 881 if (error) 882 vput(vp); 883 else 884 VOP_UNLOCK(vp); 885 vrele(nd.ni_dvp); 886 vn_finished_write(wrtmp); 887 process_deferred_inactive(mp); 888 return (error); 889 } 890 891 /* 892 * Copy a cylinder group map. All the unallocated blocks are marked 893 * BLK_NOCOPY so that the snapshot knows that it need not copy them 894 * if they are later written. If passno is one, then this is a first 895 * pass, so only setting needs to be done. If passno is 2, then this 896 * is a revision to a previous pass which must be undone as the 897 * replacement pass is done. 898 */ 899 static int 900 cgaccount(cg, vp, nbp, passno) 901 int cg; 902 struct vnode *vp; 903 struct buf *nbp; 904 int passno; 905 { 906 struct buf *bp, *ibp; 907 struct inode *ip; 908 struct cg *cgp; 909 struct fs *fs; 910 ufs2_daddr_t base, numblks; 911 int error, len, loc, indiroff; 912 913 ip = VTOI(vp); 914 fs = ITOFS(ip); 915 if ((error = ffs_getcg(fs, ITODEVVP(ip), cg, 0, &bp, &cgp)) != 0) 916 return (error); 917 UFS_LOCK(ITOUMP(ip)); 918 ACTIVESET(fs, cg); 919 /* 920 * Recomputation of summary information might not have been performed 921 * at mount time. Sync up summary information for current cylinder 922 * group while data is in memory to ensure that result of background 923 * fsck is slightly more consistent. 924 */ 925 fs->fs_cs(fs, cg) = cgp->cg_cs; 926 UFS_UNLOCK(ITOUMP(ip)); 927 bcopy(bp->b_data, nbp->b_data, fs->fs_cgsize); 928 if (fs->fs_cgsize < fs->fs_bsize) 929 bzero(&nbp->b_data[fs->fs_cgsize], 930 fs->fs_bsize - fs->fs_cgsize); 931 cgp = (struct cg *)nbp->b_data; 932 bqrelse(bp); 933 if (passno == 2) 934 nbp->b_flags |= B_VALIDSUSPWRT; 935 numblks = howmany(fs->fs_size, fs->fs_frag); 936 len = howmany(fs->fs_fpg, fs->fs_frag); 937 base = cgbase(fs, cg) / fs->fs_frag; 938 if (base + len >= numblks) 939 len = numblks - base - 1; 940 loc = 0; 941 if (base < UFS_NDADDR) { 942 for ( ; loc < UFS_NDADDR; loc++) { 943 if (ffs_isblock(fs, cg_blksfree(cgp), loc)) 944 DIP_SET(ip, i_db[loc], BLK_NOCOPY); 945 else if (passno == 2 && DIP(ip, i_db[loc])== BLK_NOCOPY) 946 DIP_SET(ip, i_db[loc], 0); 947 else if (passno == 1 && DIP(ip, i_db[loc])== BLK_NOCOPY) 948 panic("ffs_snapshot: lost direct block"); 949 } 950 } 951 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(base + loc)), 952 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 953 if (error) { 954 goto out; 955 } 956 indiroff = (base + loc - UFS_NDADDR) % NINDIR(fs); 957 for ( ; loc < len; loc++, indiroff++) { 958 if (indiroff >= NINDIR(fs)) { 959 if (passno == 2) 960 ibp->b_flags |= B_VALIDSUSPWRT; 961 bawrite(ibp); 962 error = UFS_BALLOC(vp, 963 lblktosize(fs, (off_t)(base + loc)), 964 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 965 if (error) { 966 goto out; 967 } 968 indiroff = 0; 969 } 970 if (I_IS_UFS1(ip)) { 971 if (ffs_isblock(fs, cg_blksfree(cgp), loc)) 972 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] = 973 BLK_NOCOPY; 974 else if (passno == 2 && ((ufs1_daddr_t *)(ibp->b_data)) 975 [indiroff] == BLK_NOCOPY) 976 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] = 0; 977 else if (passno == 1 && ((ufs1_daddr_t *)(ibp->b_data)) 978 [indiroff] == BLK_NOCOPY) 979 panic("ffs_snapshot: lost indirect block"); 980 continue; 981 } 982 if (ffs_isblock(fs, cg_blksfree(cgp), loc)) 983 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = BLK_NOCOPY; 984 else if (passno == 2 && 985 ((ufs2_daddr_t *)(ibp->b_data)) [indiroff] == BLK_NOCOPY) 986 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = 0; 987 else if (passno == 1 && 988 ((ufs2_daddr_t *)(ibp->b_data)) [indiroff] == BLK_NOCOPY) 989 panic("ffs_snapshot: lost indirect block"); 990 } 991 if (passno == 2) 992 ibp->b_flags |= B_VALIDSUSPWRT; 993 bdwrite(ibp); 994 out: 995 /* 996 * We have to calculate the crc32c here rather than just setting the 997 * BX_CYLGRP b_xflags because the allocation of the block for the 998 * the cylinder group map will always be a full size block (fs_bsize) 999 * even though the cylinder group may be smaller (fs_cgsize). The 1000 * crc32c must be computed only over fs_cgsize whereas the BX_CYLGRP 1001 * flag causes it to be computed over the size of the buffer. 1002 */ 1003 if ((fs->fs_metackhash & CK_CYLGRP) != 0) { 1004 ((struct cg *)nbp->b_data)->cg_ckhash = 0; 1005 ((struct cg *)nbp->b_data)->cg_ckhash = 1006 calculate_crc32c(~0L, nbp->b_data, fs->fs_cgsize); 1007 } 1008 return (error); 1009 } 1010 1011 /* 1012 * Before expunging a snapshot inode, note all the 1013 * blocks that it claims with BLK_SNAP so that fsck will 1014 * be able to account for those blocks properly and so 1015 * that this snapshot knows that it need not copy them 1016 * if the other snapshot holding them is freed. This code 1017 * is reproduced once each for UFS1 and UFS2. 1018 */ 1019 static int 1020 expunge_ufs1(snapvp, cancelip, fs, acctfunc, expungetype, clearmode) 1021 struct vnode *snapvp; 1022 struct inode *cancelip; 1023 struct fs *fs; 1024 int (*acctfunc)(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, 1025 struct fs *, ufs_lbn_t, int); 1026 int expungetype; 1027 int clearmode; 1028 { 1029 int i, error, indiroff; 1030 ufs_lbn_t lbn, rlbn; 1031 ufs2_daddr_t len, blkno, numblks, blksperindir; 1032 struct ufs1_dinode *dip; 1033 struct thread *td = curthread; 1034 struct buf *bp; 1035 1036 /* 1037 * Prepare to expunge the inode. If its inode block has not 1038 * yet been copied, then allocate and fill the copy. 1039 */ 1040 lbn = fragstoblks(fs, ino_to_fsba(fs, cancelip->i_number)); 1041 blkno = 0; 1042 if (lbn < UFS_NDADDR) { 1043 blkno = VTOI(snapvp)->i_din1->di_db[lbn]; 1044 } else { 1045 if (DOINGSOFTDEP(snapvp)) 1046 softdep_prealloc(snapvp, MNT_WAIT); 1047 td->td_pflags |= TDP_COWINPROGRESS; 1048 error = ffs_balloc_ufs1(snapvp, lblktosize(fs, (off_t)lbn), 1049 fs->fs_bsize, KERNCRED, BA_METAONLY, &bp); 1050 td->td_pflags &= ~TDP_COWINPROGRESS; 1051 if (error) 1052 return (error); 1053 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs); 1054 blkno = ((ufs1_daddr_t *)(bp->b_data))[indiroff]; 1055 bqrelse(bp); 1056 } 1057 if (blkno != 0) { 1058 if ((error = bread(snapvp, lbn, fs->fs_bsize, KERNCRED, &bp))) 1059 return (error); 1060 } else { 1061 error = ffs_balloc_ufs1(snapvp, lblktosize(fs, (off_t)lbn), 1062 fs->fs_bsize, KERNCRED, 0, &bp); 1063 if (error) 1064 return (error); 1065 if ((error = readblock(snapvp, bp, lbn)) != 0) 1066 return (error); 1067 } 1068 /* 1069 * Set a snapshot inode to be a zero length file, regular files 1070 * or unlinked snapshots to be completely unallocated. 1071 */ 1072 dip = (struct ufs1_dinode *)bp->b_data + 1073 ino_to_fsbo(fs, cancelip->i_number); 1074 if (clearmode || cancelip->i_effnlink == 0) 1075 dip->di_mode = 0; 1076 dip->di_size = 0; 1077 dip->di_blocks = 0; 1078 dip->di_flags &= ~SF_SNAPSHOT; 1079 bzero(&dip->di_db[0], (UFS_NDADDR + UFS_NIADDR) * sizeof(ufs1_daddr_t)); 1080 bdwrite(bp); 1081 /* 1082 * Now go through and expunge all the blocks in the file 1083 * using the function requested. 1084 */ 1085 numblks = howmany(cancelip->i_size, fs->fs_bsize); 1086 if ((error = (*acctfunc)(snapvp, &cancelip->i_din1->di_db[0], 1087 &cancelip->i_din1->di_db[UFS_NDADDR], fs, 0, expungetype))) 1088 return (error); 1089 if ((error = (*acctfunc)(snapvp, &cancelip->i_din1->di_ib[0], 1090 &cancelip->i_din1->di_ib[UFS_NIADDR], fs, -1, expungetype))) 1091 return (error); 1092 blksperindir = 1; 1093 lbn = -UFS_NDADDR; 1094 len = numblks - UFS_NDADDR; 1095 rlbn = UFS_NDADDR; 1096 for (i = 0; len > 0 && i < UFS_NIADDR; i++) { 1097 error = indiracct_ufs1(snapvp, ITOV(cancelip), i, 1098 cancelip->i_din1->di_ib[i], lbn, rlbn, len, 1099 blksperindir, fs, acctfunc, expungetype); 1100 if (error) 1101 return (error); 1102 blksperindir *= NINDIR(fs); 1103 lbn -= blksperindir + 1; 1104 len -= blksperindir; 1105 rlbn += blksperindir; 1106 } 1107 return (0); 1108 } 1109 1110 /* 1111 * Descend an indirect block chain for vnode cancelvp accounting for all 1112 * its indirect blocks in snapvp. 1113 */ 1114 static int 1115 indiracct_ufs1(snapvp, cancelvp, level, blkno, lbn, rlbn, remblks, 1116 blksperindir, fs, acctfunc, expungetype) 1117 struct vnode *snapvp; 1118 struct vnode *cancelvp; 1119 int level; 1120 ufs1_daddr_t blkno; 1121 ufs_lbn_t lbn; 1122 ufs_lbn_t rlbn; 1123 ufs_lbn_t remblks; 1124 ufs_lbn_t blksperindir; 1125 struct fs *fs; 1126 int (*acctfunc)(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, 1127 struct fs *, ufs_lbn_t, int); 1128 int expungetype; 1129 { 1130 int error, num, i; 1131 ufs_lbn_t subblksperindir; 1132 struct indir indirs[UFS_NIADDR + 2]; 1133 ufs1_daddr_t last, *bap; 1134 struct buf *bp; 1135 1136 if (blkno == 0) { 1137 if (expungetype == BLK_NOCOPY) 1138 return (0); 1139 panic("indiracct_ufs1: missing indir"); 1140 } 1141 if ((error = ufs_getlbns(cancelvp, rlbn, indirs, &num)) != 0) 1142 return (error); 1143 if (lbn != indirs[num - 1 - level].in_lbn || num < 2) 1144 panic("indiracct_ufs1: botched params"); 1145 /* 1146 * We have to expand bread here since it will deadlock looking 1147 * up the block number for any blocks that are not in the cache. 1148 */ 1149 bp = getblk(cancelvp, lbn, fs->fs_bsize, 0, 0, 0); 1150 bp->b_blkno = fsbtodb(fs, blkno); 1151 if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0 && 1152 (error = readblock(cancelvp, bp, fragstoblks(fs, blkno)))) { 1153 brelse(bp); 1154 return (error); 1155 } 1156 /* 1157 * Account for the block pointers in this indirect block. 1158 */ 1159 last = howmany(remblks, blksperindir); 1160 if (last > NINDIR(fs)) 1161 last = NINDIR(fs); 1162 bap = malloc(fs->fs_bsize, M_DEVBUF, M_WAITOK); 1163 bcopy(bp->b_data, (caddr_t)bap, fs->fs_bsize); 1164 bqrelse(bp); 1165 error = (*acctfunc)(snapvp, &bap[0], &bap[last], fs, 1166 level == 0 ? rlbn : -1, expungetype); 1167 if (error || level == 0) 1168 goto out; 1169 /* 1170 * Account for the block pointers in each of the indirect blocks 1171 * in the levels below us. 1172 */ 1173 subblksperindir = blksperindir / NINDIR(fs); 1174 for (lbn++, level--, i = 0; i < last; i++) { 1175 error = indiracct_ufs1(snapvp, cancelvp, level, bap[i], lbn, 1176 rlbn, remblks, subblksperindir, fs, acctfunc, expungetype); 1177 if (error) 1178 goto out; 1179 rlbn += blksperindir; 1180 lbn -= blksperindir; 1181 remblks -= blksperindir; 1182 } 1183 out: 1184 free(bap, M_DEVBUF); 1185 return (error); 1186 } 1187 1188 /* 1189 * Do both snap accounting and map accounting. 1190 */ 1191 static int 1192 fullacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, exptype) 1193 struct vnode *vp; 1194 ufs1_daddr_t *oldblkp, *lastblkp; 1195 struct fs *fs; 1196 ufs_lbn_t lblkno; 1197 int exptype; /* BLK_SNAP or BLK_NOCOPY */ 1198 { 1199 int error; 1200 1201 if ((error = snapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, exptype))) 1202 return (error); 1203 return (mapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, exptype)); 1204 } 1205 1206 /* 1207 * Identify a set of blocks allocated in a snapshot inode. 1208 */ 1209 static int 1210 snapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, expungetype) 1211 struct vnode *vp; 1212 ufs1_daddr_t *oldblkp, *lastblkp; 1213 struct fs *fs; 1214 ufs_lbn_t lblkno; 1215 int expungetype; /* BLK_SNAP or BLK_NOCOPY */ 1216 { 1217 struct inode *ip = VTOI(vp); 1218 ufs1_daddr_t blkno, *blkp; 1219 ufs_lbn_t lbn; 1220 struct buf *ibp; 1221 int error; 1222 1223 for ( ; oldblkp < lastblkp; oldblkp++) { 1224 blkno = *oldblkp; 1225 if (blkno == 0 || blkno == BLK_NOCOPY || blkno == BLK_SNAP) 1226 continue; 1227 lbn = fragstoblks(fs, blkno); 1228 if (lbn < UFS_NDADDR) { 1229 blkp = &ip->i_din1->di_db[lbn]; 1230 UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE); 1231 } else { 1232 error = ffs_balloc_ufs1(vp, lblktosize(fs, (off_t)lbn), 1233 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 1234 if (error) 1235 return (error); 1236 blkp = &((ufs1_daddr_t *)(ibp->b_data)) 1237 [(lbn - UFS_NDADDR) % NINDIR(fs)]; 1238 } 1239 /* 1240 * If we are expunging a snapshot vnode and we 1241 * find a block marked BLK_NOCOPY, then it is 1242 * one that has been allocated to this snapshot after 1243 * we took our current snapshot and can be ignored. 1244 */ 1245 if (expungetype == BLK_SNAP && *blkp == BLK_NOCOPY) { 1246 if (lbn >= UFS_NDADDR) 1247 brelse(ibp); 1248 } else { 1249 if (*blkp != 0) 1250 panic("snapacct_ufs1: bad block"); 1251 *blkp = expungetype; 1252 if (lbn >= UFS_NDADDR) 1253 bdwrite(ibp); 1254 } 1255 } 1256 return (0); 1257 } 1258 1259 /* 1260 * Account for a set of blocks allocated in a snapshot inode. 1261 */ 1262 static int 1263 mapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, expungetype) 1264 struct vnode *vp; 1265 ufs1_daddr_t *oldblkp, *lastblkp; 1266 struct fs *fs; 1267 ufs_lbn_t lblkno; 1268 int expungetype; 1269 { 1270 ufs1_daddr_t blkno; 1271 struct inode *ip; 1272 ino_t inum; 1273 int acctit; 1274 1275 ip = VTOI(vp); 1276 inum = ip->i_number; 1277 if (lblkno == -1) 1278 acctit = 0; 1279 else 1280 acctit = 1; 1281 for ( ; oldblkp < lastblkp; oldblkp++, lblkno++) { 1282 blkno = *oldblkp; 1283 if (blkno == 0 || blkno == BLK_NOCOPY) 1284 continue; 1285 if (acctit && expungetype == BLK_SNAP && blkno != BLK_SNAP) 1286 *ip->i_snapblklist++ = lblkno; 1287 if (blkno == BLK_SNAP) 1288 blkno = blkstofrags(fs, lblkno); 1289 ffs_blkfree(ITOUMP(ip), fs, vp, blkno, fs->fs_bsize, inum, 1290 vp->v_type, NULL, SINGLETON_KEY); 1291 } 1292 return (0); 1293 } 1294 1295 /* 1296 * Before expunging a snapshot inode, note all the 1297 * blocks that it claims with BLK_SNAP so that fsck will 1298 * be able to account for those blocks properly and so 1299 * that this snapshot knows that it need not copy them 1300 * if the other snapshot holding them is freed. This code 1301 * is reproduced once each for UFS1 and UFS2. 1302 */ 1303 static int 1304 expunge_ufs2(snapvp, cancelip, fs, acctfunc, expungetype, clearmode) 1305 struct vnode *snapvp; 1306 struct inode *cancelip; 1307 struct fs *fs; 1308 int (*acctfunc)(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, 1309 struct fs *, ufs_lbn_t, int); 1310 int expungetype; 1311 int clearmode; 1312 { 1313 int i, error, indiroff; 1314 ufs_lbn_t lbn, rlbn; 1315 ufs2_daddr_t len, blkno, numblks, blksperindir; 1316 struct ufs2_dinode *dip; 1317 struct thread *td = curthread; 1318 struct buf *bp; 1319 1320 /* 1321 * Prepare to expunge the inode. If its inode block has not 1322 * yet been copied, then allocate and fill the copy. 1323 */ 1324 lbn = fragstoblks(fs, ino_to_fsba(fs, cancelip->i_number)); 1325 blkno = 0; 1326 if (lbn < UFS_NDADDR) { 1327 blkno = VTOI(snapvp)->i_din2->di_db[lbn]; 1328 } else { 1329 if (DOINGSOFTDEP(snapvp)) 1330 softdep_prealloc(snapvp, MNT_WAIT); 1331 td->td_pflags |= TDP_COWINPROGRESS; 1332 error = ffs_balloc_ufs2(snapvp, lblktosize(fs, (off_t)lbn), 1333 fs->fs_bsize, KERNCRED, BA_METAONLY, &bp); 1334 td->td_pflags &= ~TDP_COWINPROGRESS; 1335 if (error) 1336 return (error); 1337 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs); 1338 blkno = ((ufs2_daddr_t *)(bp->b_data))[indiroff]; 1339 bqrelse(bp); 1340 } 1341 if (blkno != 0) { 1342 if ((error = bread(snapvp, lbn, fs->fs_bsize, KERNCRED, &bp))) 1343 return (error); 1344 } else { 1345 error = ffs_balloc_ufs2(snapvp, lblktosize(fs, (off_t)lbn), 1346 fs->fs_bsize, KERNCRED, 0, &bp); 1347 if (error) 1348 return (error); 1349 if ((error = readblock(snapvp, bp, lbn)) != 0) 1350 return (error); 1351 } 1352 /* 1353 * Set a snapshot inode to be a zero length file, regular files 1354 * to be completely unallocated. 1355 */ 1356 dip = (struct ufs2_dinode *)bp->b_data + 1357 ino_to_fsbo(fs, cancelip->i_number); 1358 dip->di_size = 0; 1359 dip->di_blocks = 0; 1360 dip->di_flags &= ~SF_SNAPSHOT; 1361 bzero(&dip->di_db[0], (UFS_NDADDR + UFS_NIADDR) * sizeof(ufs2_daddr_t)); 1362 if (clearmode || cancelip->i_effnlink == 0) 1363 dip->di_mode = 0; 1364 else 1365 ffs_update_dinode_ckhash(fs, dip); 1366 bdwrite(bp); 1367 /* 1368 * Now go through and expunge all the blocks in the file 1369 * using the function requested. 1370 */ 1371 numblks = howmany(cancelip->i_size, fs->fs_bsize); 1372 if ((error = (*acctfunc)(snapvp, &cancelip->i_din2->di_db[0], 1373 &cancelip->i_din2->di_db[UFS_NDADDR], fs, 0, expungetype))) 1374 return (error); 1375 if ((error = (*acctfunc)(snapvp, &cancelip->i_din2->di_ib[0], 1376 &cancelip->i_din2->di_ib[UFS_NIADDR], fs, -1, expungetype))) 1377 return (error); 1378 blksperindir = 1; 1379 lbn = -UFS_NDADDR; 1380 len = numblks - UFS_NDADDR; 1381 rlbn = UFS_NDADDR; 1382 for (i = 0; len > 0 && i < UFS_NIADDR; i++) { 1383 error = indiracct_ufs2(snapvp, ITOV(cancelip), i, 1384 cancelip->i_din2->di_ib[i], lbn, rlbn, len, 1385 blksperindir, fs, acctfunc, expungetype); 1386 if (error) 1387 return (error); 1388 blksperindir *= NINDIR(fs); 1389 lbn -= blksperindir + 1; 1390 len -= blksperindir; 1391 rlbn += blksperindir; 1392 } 1393 return (0); 1394 } 1395 1396 /* 1397 * Descend an indirect block chain for vnode cancelvp accounting for all 1398 * its indirect blocks in snapvp. 1399 */ 1400 static int 1401 indiracct_ufs2(snapvp, cancelvp, level, blkno, lbn, rlbn, remblks, 1402 blksperindir, fs, acctfunc, expungetype) 1403 struct vnode *snapvp; 1404 struct vnode *cancelvp; 1405 int level; 1406 ufs2_daddr_t blkno; 1407 ufs_lbn_t lbn; 1408 ufs_lbn_t rlbn; 1409 ufs_lbn_t remblks; 1410 ufs_lbn_t blksperindir; 1411 struct fs *fs; 1412 int (*acctfunc)(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, 1413 struct fs *, ufs_lbn_t, int); 1414 int expungetype; 1415 { 1416 int error, num, i; 1417 ufs_lbn_t subblksperindir; 1418 struct indir indirs[UFS_NIADDR + 2]; 1419 ufs2_daddr_t last, *bap; 1420 struct buf *bp; 1421 1422 if (blkno == 0) { 1423 if (expungetype == BLK_NOCOPY) 1424 return (0); 1425 panic("indiracct_ufs2: missing indir"); 1426 } 1427 if ((error = ufs_getlbns(cancelvp, rlbn, indirs, &num)) != 0) 1428 return (error); 1429 if (lbn != indirs[num - 1 - level].in_lbn || num < 2) 1430 panic("indiracct_ufs2: botched params"); 1431 /* 1432 * We have to expand bread here since it will deadlock looking 1433 * up the block number for any blocks that are not in the cache. 1434 */ 1435 bp = getblk(cancelvp, lbn, fs->fs_bsize, 0, 0, 0); 1436 bp->b_blkno = fsbtodb(fs, blkno); 1437 if ((bp->b_flags & B_CACHE) == 0 && 1438 (error = readblock(cancelvp, bp, fragstoblks(fs, blkno)))) { 1439 brelse(bp); 1440 return (error); 1441 } 1442 /* 1443 * Account for the block pointers in this indirect block. 1444 */ 1445 last = howmany(remblks, blksperindir); 1446 if (last > NINDIR(fs)) 1447 last = NINDIR(fs); 1448 bap = malloc(fs->fs_bsize, M_DEVBUF, M_WAITOK); 1449 bcopy(bp->b_data, (caddr_t)bap, fs->fs_bsize); 1450 bqrelse(bp); 1451 error = (*acctfunc)(snapvp, &bap[0], &bap[last], fs, 1452 level == 0 ? rlbn : -1, expungetype); 1453 if (error || level == 0) 1454 goto out; 1455 /* 1456 * Account for the block pointers in each of the indirect blocks 1457 * in the levels below us. 1458 */ 1459 subblksperindir = blksperindir / NINDIR(fs); 1460 for (lbn++, level--, i = 0; i < last; i++) { 1461 error = indiracct_ufs2(snapvp, cancelvp, level, bap[i], lbn, 1462 rlbn, remblks, subblksperindir, fs, acctfunc, expungetype); 1463 if (error) 1464 goto out; 1465 rlbn += blksperindir; 1466 lbn -= blksperindir; 1467 remblks -= blksperindir; 1468 } 1469 out: 1470 free(bap, M_DEVBUF); 1471 return (error); 1472 } 1473 1474 /* 1475 * Do both snap accounting and map accounting. 1476 */ 1477 static int 1478 fullacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, exptype) 1479 struct vnode *vp; 1480 ufs2_daddr_t *oldblkp, *lastblkp; 1481 struct fs *fs; 1482 ufs_lbn_t lblkno; 1483 int exptype; /* BLK_SNAP or BLK_NOCOPY */ 1484 { 1485 int error; 1486 1487 if ((error = snapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, exptype))) 1488 return (error); 1489 return (mapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, exptype)); 1490 } 1491 1492 /* 1493 * Identify a set of blocks allocated in a snapshot inode. 1494 */ 1495 static int 1496 snapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, expungetype) 1497 struct vnode *vp; 1498 ufs2_daddr_t *oldblkp, *lastblkp; 1499 struct fs *fs; 1500 ufs_lbn_t lblkno; 1501 int expungetype; /* BLK_SNAP or BLK_NOCOPY */ 1502 { 1503 struct inode *ip = VTOI(vp); 1504 ufs2_daddr_t blkno, *blkp; 1505 ufs_lbn_t lbn; 1506 struct buf *ibp; 1507 int error; 1508 1509 for ( ; oldblkp < lastblkp; oldblkp++) { 1510 blkno = *oldblkp; 1511 if (blkno == 0 || blkno == BLK_NOCOPY || blkno == BLK_SNAP) 1512 continue; 1513 lbn = fragstoblks(fs, blkno); 1514 if (lbn < UFS_NDADDR) { 1515 blkp = &ip->i_din2->di_db[lbn]; 1516 UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE); 1517 } else { 1518 error = ffs_balloc_ufs2(vp, lblktosize(fs, (off_t)lbn), 1519 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 1520 if (error) 1521 return (error); 1522 blkp = &((ufs2_daddr_t *)(ibp->b_data)) 1523 [(lbn - UFS_NDADDR) % NINDIR(fs)]; 1524 } 1525 /* 1526 * If we are expunging a snapshot vnode and we 1527 * find a block marked BLK_NOCOPY, then it is 1528 * one that has been allocated to this snapshot after 1529 * we took our current snapshot and can be ignored. 1530 */ 1531 if (expungetype == BLK_SNAP && *blkp == BLK_NOCOPY) { 1532 if (lbn >= UFS_NDADDR) 1533 brelse(ibp); 1534 } else { 1535 if (*blkp != 0) 1536 panic("snapacct_ufs2: bad block"); 1537 *blkp = expungetype; 1538 if (lbn >= UFS_NDADDR) 1539 bdwrite(ibp); 1540 } 1541 } 1542 return (0); 1543 } 1544 1545 /* 1546 * Account for a set of blocks allocated in a snapshot inode. 1547 */ 1548 static int 1549 mapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, expungetype) 1550 struct vnode *vp; 1551 ufs2_daddr_t *oldblkp, *lastblkp; 1552 struct fs *fs; 1553 ufs_lbn_t lblkno; 1554 int expungetype; 1555 { 1556 ufs2_daddr_t blkno; 1557 struct inode *ip; 1558 ino_t inum; 1559 int acctit; 1560 1561 ip = VTOI(vp); 1562 inum = ip->i_number; 1563 if (lblkno == -1) 1564 acctit = 0; 1565 else 1566 acctit = 1; 1567 for ( ; oldblkp < lastblkp; oldblkp++, lblkno++) { 1568 blkno = *oldblkp; 1569 if (blkno == 0 || blkno == BLK_NOCOPY) 1570 continue; 1571 if (acctit && expungetype == BLK_SNAP && blkno != BLK_SNAP) 1572 *ip->i_snapblklist++ = lblkno; 1573 if (blkno == BLK_SNAP) 1574 blkno = blkstofrags(fs, lblkno); 1575 ffs_blkfree(ITOUMP(ip), fs, vp, blkno, fs->fs_bsize, inum, 1576 vp->v_type, NULL, SINGLETON_KEY); 1577 } 1578 return (0); 1579 } 1580 1581 /* 1582 * Decrement extra reference on snapshot when last name is removed. 1583 * It will not be freed until the last open reference goes away. 1584 */ 1585 void 1586 ffs_snapgone(ip) 1587 struct inode *ip; 1588 { 1589 struct inode *xp; 1590 struct fs *fs; 1591 int snaploc; 1592 struct snapdata *sn; 1593 struct ufsmount *ump; 1594 1595 /* 1596 * Find snapshot in incore list. 1597 */ 1598 xp = NULL; 1599 sn = ITODEVVP(ip)->v_rdev->si_snapdata; 1600 if (sn != NULL) 1601 TAILQ_FOREACH(xp, &sn->sn_head, i_nextsnap) 1602 if (xp == ip) 1603 break; 1604 if (xp != NULL) 1605 vrele(ITOV(ip)); 1606 #ifdef DIAGNOSTIC 1607 else if (snapdebug) 1608 printf("ffs_snapgone: lost snapshot vnode %ju\n", 1609 (uintmax_t)ip->i_number); 1610 #endif 1611 /* 1612 * Delete snapshot inode from superblock. Keep list dense. 1613 */ 1614 ump = ITOUMP(ip); 1615 fs = ump->um_fs; 1616 UFS_LOCK(ump); 1617 for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++) 1618 if (fs->fs_snapinum[snaploc] == ip->i_number) 1619 break; 1620 if (snaploc < FSMAXSNAP) { 1621 for (snaploc++; snaploc < FSMAXSNAP; snaploc++) { 1622 if (fs->fs_snapinum[snaploc] == 0) 1623 break; 1624 fs->fs_snapinum[snaploc - 1] = fs->fs_snapinum[snaploc]; 1625 } 1626 fs->fs_snapinum[snaploc - 1] = 0; 1627 } 1628 UFS_UNLOCK(ump); 1629 } 1630 1631 /* 1632 * Prepare a snapshot file for being removed. 1633 */ 1634 void 1635 ffs_snapremove(vp) 1636 struct vnode *vp; 1637 { 1638 struct inode *ip; 1639 struct vnode *devvp; 1640 struct buf *ibp; 1641 struct fs *fs; 1642 ufs2_daddr_t numblks, blkno, dblk; 1643 int error, i, last, loc; 1644 struct snapdata *sn; 1645 1646 ip = VTOI(vp); 1647 fs = ITOFS(ip); 1648 devvp = ITODEVVP(ip); 1649 /* 1650 * If active, delete from incore list (this snapshot may 1651 * already have been in the process of being deleted, so 1652 * would not have been active). 1653 * 1654 * Clear copy-on-write flag if last snapshot. 1655 */ 1656 VI_LOCK(devvp); 1657 if (ip->i_nextsnap.tqe_prev != 0) { 1658 sn = devvp->v_rdev->si_snapdata; 1659 TAILQ_REMOVE(&sn->sn_head, ip, i_nextsnap); 1660 ip->i_nextsnap.tqe_prev = 0; 1661 VI_UNLOCK(devvp); 1662 lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL); 1663 for (i = 0; i < sn->sn_lock.lk_recurse; i++) 1664 lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL); 1665 KASSERT(vp->v_vnlock == &sn->sn_lock, 1666 ("ffs_snapremove: lost lock mutation")); 1667 vp->v_vnlock = &vp->v_lock; 1668 VI_LOCK(devvp); 1669 while (sn->sn_lock.lk_recurse > 0) 1670 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 1671 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 1672 try_free_snapdata(devvp); 1673 } else 1674 VI_UNLOCK(devvp); 1675 /* 1676 * Clear all BLK_NOCOPY fields. Pass any block claims to other 1677 * snapshots that want them (see ffs_snapblkfree below). 1678 */ 1679 for (blkno = 1; blkno < UFS_NDADDR; blkno++) { 1680 dblk = DIP(ip, i_db[blkno]); 1681 if (dblk == 0) 1682 continue; 1683 if (dblk == BLK_NOCOPY || dblk == BLK_SNAP) 1684 DIP_SET(ip, i_db[blkno], 0); 1685 else if ((dblk == blkstofrags(fs, blkno) && 1686 ffs_snapblkfree(fs, ITODEVVP(ip), dblk, fs->fs_bsize, 1687 ip->i_number, vp->v_type, NULL))) { 1688 DIP_SET(ip, i_blocks, DIP(ip, i_blocks) - 1689 btodb(fs->fs_bsize)); 1690 DIP_SET(ip, i_db[blkno], 0); 1691 } 1692 } 1693 numblks = howmany(ip->i_size, fs->fs_bsize); 1694 for (blkno = UFS_NDADDR; blkno < numblks; blkno += NINDIR(fs)) { 1695 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)blkno), 1696 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 1697 if (error) 1698 continue; 1699 if (fs->fs_size - blkno > NINDIR(fs)) 1700 last = NINDIR(fs); 1701 else 1702 last = fs->fs_size - blkno; 1703 for (loc = 0; loc < last; loc++) { 1704 if (I_IS_UFS1(ip)) { 1705 dblk = ((ufs1_daddr_t *)(ibp->b_data))[loc]; 1706 if (dblk == 0) 1707 continue; 1708 if (dblk == BLK_NOCOPY || dblk == BLK_SNAP) 1709 ((ufs1_daddr_t *)(ibp->b_data))[loc]= 0; 1710 else if ((dblk == blkstofrags(fs, blkno) && 1711 ffs_snapblkfree(fs, ITODEVVP(ip), dblk, 1712 fs->fs_bsize, ip->i_number, vp->v_type, 1713 NULL))) { 1714 ip->i_din1->di_blocks -= 1715 btodb(fs->fs_bsize); 1716 ((ufs1_daddr_t *)(ibp->b_data))[loc]= 0; 1717 } 1718 continue; 1719 } 1720 dblk = ((ufs2_daddr_t *)(ibp->b_data))[loc]; 1721 if (dblk == 0) 1722 continue; 1723 if (dblk == BLK_NOCOPY || dblk == BLK_SNAP) 1724 ((ufs2_daddr_t *)(ibp->b_data))[loc] = 0; 1725 else if ((dblk == blkstofrags(fs, blkno) && 1726 ffs_snapblkfree(fs, ITODEVVP(ip), dblk, 1727 fs->fs_bsize, ip->i_number, vp->v_type, NULL))) { 1728 ip->i_din2->di_blocks -= btodb(fs->fs_bsize); 1729 ((ufs2_daddr_t *)(ibp->b_data))[loc] = 0; 1730 } 1731 } 1732 bawrite(ibp); 1733 } 1734 /* 1735 * Clear snapshot flag and drop reference. 1736 */ 1737 ip->i_flags &= ~SF_SNAPSHOT; 1738 DIP_SET(ip, i_flags, ip->i_flags); 1739 UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE); 1740 /* 1741 * The dirtied indirects must be written out before 1742 * softdep_setup_freeblocks() is called. Otherwise indir_trunc() 1743 * may find indirect pointers using the magic BLK_* values. 1744 */ 1745 if (DOINGSOFTDEP(vp)) 1746 ffs_syncvnode(vp, MNT_WAIT, 0); 1747 #ifdef QUOTA 1748 /* 1749 * Reenable disk quotas for ex-snapshot file. 1750 */ 1751 if (!getinoquota(ip)) 1752 (void) chkdq(ip, DIP(ip, i_blocks), KERNCRED, FORCE); 1753 #endif 1754 } 1755 1756 /* 1757 * Notification that a block is being freed. Return zero if the free 1758 * should be allowed to proceed. Return non-zero if the snapshot file 1759 * wants to claim the block. The block will be claimed if it is an 1760 * uncopied part of one of the snapshots. It will be freed if it is 1761 * either a BLK_NOCOPY or has already been copied in all of the snapshots. 1762 * If a fragment is being freed, then all snapshots that care about 1763 * it must make a copy since a snapshot file can only claim full sized 1764 * blocks. Note that if more than one snapshot file maps the block, 1765 * we can pick one at random to claim it. Since none of the snapshots 1766 * can change, we are assurred that they will all see the same unmodified 1767 * image. When deleting a snapshot file (see ffs_snapremove above), we 1768 * must push any of these claimed blocks to one of the other snapshots 1769 * that maps it. These claimed blocks are easily identified as they will 1770 * have a block number equal to their logical block number within the 1771 * snapshot. A copied block can never have this property because they 1772 * must always have been allocated from a BLK_NOCOPY location. 1773 */ 1774 int 1775 ffs_snapblkfree(fs, devvp, bno, size, inum, vtype, wkhd) 1776 struct fs *fs; 1777 struct vnode *devvp; 1778 ufs2_daddr_t bno; 1779 long size; 1780 ino_t inum; 1781 enum vtype vtype; 1782 struct workhead *wkhd; 1783 { 1784 struct buf *ibp, *cbp, *savedcbp = NULL; 1785 struct thread *td = curthread; 1786 struct inode *ip; 1787 struct vnode *vp = NULL; 1788 ufs_lbn_t lbn; 1789 ufs2_daddr_t blkno; 1790 int indiroff = 0, error = 0, claimedblk = 0; 1791 struct snapdata *sn; 1792 1793 lbn = fragstoblks(fs, bno); 1794 retry: 1795 VI_LOCK(devvp); 1796 sn = devvp->v_rdev->si_snapdata; 1797 if (sn == NULL) { 1798 VI_UNLOCK(devvp); 1799 return (0); 1800 } 1801 if (lockmgr(&sn->sn_lock, LK_INTERLOCK | LK_EXCLUSIVE | LK_SLEEPFAIL, 1802 VI_MTX(devvp)) != 0) 1803 goto retry; 1804 TAILQ_FOREACH(ip, &sn->sn_head, i_nextsnap) { 1805 vp = ITOV(ip); 1806 if (DOINGSOFTDEP(vp)) 1807 softdep_prealloc(vp, MNT_WAIT); 1808 /* 1809 * Lookup block being written. 1810 */ 1811 if (lbn < UFS_NDADDR) { 1812 blkno = DIP(ip, i_db[lbn]); 1813 } else { 1814 td->td_pflags |= TDP_COWINPROGRESS; 1815 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn), 1816 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 1817 td->td_pflags &= ~TDP_COWINPROGRESS; 1818 if (error) 1819 break; 1820 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs); 1821 if (I_IS_UFS1(ip)) 1822 blkno=((ufs1_daddr_t *)(ibp->b_data))[indiroff]; 1823 else 1824 blkno=((ufs2_daddr_t *)(ibp->b_data))[indiroff]; 1825 } 1826 /* 1827 * Check to see if block needs to be copied. 1828 */ 1829 if (blkno == 0) { 1830 /* 1831 * A block that we map is being freed. If it has not 1832 * been claimed yet, we will claim or copy it (below). 1833 */ 1834 claimedblk = 1; 1835 } else if (blkno == BLK_SNAP) { 1836 /* 1837 * No previous snapshot claimed the block, 1838 * so it will be freed and become a BLK_NOCOPY 1839 * (don't care) for us. 1840 */ 1841 if (claimedblk) 1842 panic("snapblkfree: inconsistent block type"); 1843 if (lbn < UFS_NDADDR) { 1844 DIP_SET(ip, i_db[lbn], BLK_NOCOPY); 1845 UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE); 1846 } else if (I_IS_UFS1(ip)) { 1847 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] = 1848 BLK_NOCOPY; 1849 bdwrite(ibp); 1850 } else { 1851 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = 1852 BLK_NOCOPY; 1853 bdwrite(ibp); 1854 } 1855 continue; 1856 } else /* BLK_NOCOPY or default */ { 1857 /* 1858 * If the snapshot has already copied the block 1859 * (default), or does not care about the block, 1860 * it is not needed. 1861 */ 1862 if (lbn >= UFS_NDADDR) 1863 bqrelse(ibp); 1864 continue; 1865 } 1866 /* 1867 * If this is a full size block, we will just grab it 1868 * and assign it to the snapshot inode. Otherwise we 1869 * will proceed to copy it. See explanation for this 1870 * routine as to why only a single snapshot needs to 1871 * claim this block. 1872 */ 1873 if (size == fs->fs_bsize) { 1874 #ifdef DIAGNOSTIC 1875 if (snapdebug) 1876 printf("%s %ju lbn %jd from inum %ju\n", 1877 "Grabonremove: snapino", 1878 (uintmax_t)ip->i_number, 1879 (intmax_t)lbn, (uintmax_t)inum); 1880 #endif 1881 /* 1882 * If journaling is tracking this write we must add 1883 * the work to the inode or indirect being written. 1884 */ 1885 if (wkhd != NULL) { 1886 if (lbn < UFS_NDADDR) 1887 softdep_inode_append(ip, 1888 curthread->td_ucred, wkhd); 1889 else 1890 softdep_buf_append(ibp, wkhd); 1891 } 1892 if (lbn < UFS_NDADDR) { 1893 DIP_SET(ip, i_db[lbn], bno); 1894 } else if (I_IS_UFS1(ip)) { 1895 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] = bno; 1896 bdwrite(ibp); 1897 } else { 1898 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = bno; 1899 bdwrite(ibp); 1900 } 1901 DIP_SET(ip, i_blocks, DIP(ip, i_blocks) + btodb(size)); 1902 UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE); 1903 lockmgr(vp->v_vnlock, LK_RELEASE, NULL); 1904 return (1); 1905 } 1906 if (lbn >= UFS_NDADDR) 1907 bqrelse(ibp); 1908 /* 1909 * Allocate the block into which to do the copy. Note that this 1910 * allocation will never require any additional allocations for 1911 * the snapshot inode. 1912 */ 1913 td->td_pflags |= TDP_COWINPROGRESS; 1914 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn), 1915 fs->fs_bsize, KERNCRED, 0, &cbp); 1916 td->td_pflags &= ~TDP_COWINPROGRESS; 1917 if (error) 1918 break; 1919 #ifdef DIAGNOSTIC 1920 if (snapdebug) 1921 printf("%s%ju lbn %jd %s %ju size %ld to blkno %jd\n", 1922 "Copyonremove: snapino ", (uintmax_t)ip->i_number, 1923 (intmax_t)lbn, "for inum", (uintmax_t)inum, size, 1924 (intmax_t)cbp->b_blkno); 1925 #endif 1926 /* 1927 * If we have already read the old block contents, then 1928 * simply copy them to the new block. Note that we need 1929 * to synchronously write snapshots that have not been 1930 * unlinked, and hence will be visible after a crash, 1931 * to ensure their integrity. At a minimum we ensure the 1932 * integrity of the filesystem metadata, but use the 1933 * dopersistence sysctl-setable flag to decide on the 1934 * persistence needed for file content data. 1935 */ 1936 if (savedcbp != NULL) { 1937 bcopy(savedcbp->b_data, cbp->b_data, fs->fs_bsize); 1938 bawrite(cbp); 1939 if ((vtype == VDIR || dopersistence) && 1940 ip->i_effnlink > 0) 1941 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 1942 continue; 1943 } 1944 /* 1945 * Otherwise, read the old block contents into the buffer. 1946 */ 1947 if ((error = readblock(vp, cbp, lbn)) != 0) { 1948 bzero(cbp->b_data, fs->fs_bsize); 1949 bawrite(cbp); 1950 if ((vtype == VDIR || dopersistence) && 1951 ip->i_effnlink > 0) 1952 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 1953 break; 1954 } 1955 savedcbp = cbp; 1956 } 1957 /* 1958 * Note that we need to synchronously write snapshots that 1959 * have not been unlinked, and hence will be visible after 1960 * a crash, to ensure their integrity. At a minimum we 1961 * ensure the integrity of the filesystem metadata, but 1962 * use the dopersistence sysctl-setable flag to decide on 1963 * the persistence needed for file content data. 1964 */ 1965 if (savedcbp) { 1966 vp = savedcbp->b_vp; 1967 bawrite(savedcbp); 1968 if ((vtype == VDIR || dopersistence) && 1969 VTOI(vp)->i_effnlink > 0) 1970 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 1971 } 1972 /* 1973 * If we have been unable to allocate a block in which to do 1974 * the copy, then return non-zero so that the fragment will 1975 * not be freed. Although space will be lost, the snapshot 1976 * will stay consistent. 1977 */ 1978 if (error != 0 && wkhd != NULL) 1979 softdep_freework(wkhd); 1980 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 1981 return (error); 1982 } 1983 1984 /* 1985 * Associate snapshot files when mounting. 1986 */ 1987 void 1988 ffs_snapshot_mount(mp) 1989 struct mount *mp; 1990 { 1991 struct ufsmount *ump = VFSTOUFS(mp); 1992 struct vnode *devvp = ump->um_devvp; 1993 struct fs *fs = ump->um_fs; 1994 struct thread *td = curthread; 1995 struct snapdata *sn; 1996 struct vnode *vp; 1997 struct vnode *lastvp; 1998 struct inode *ip; 1999 struct uio auio; 2000 struct iovec aiov; 2001 void *snapblklist; 2002 char *reason; 2003 daddr_t snaplistsize; 2004 int error, snaploc, loc; 2005 2006 /* 2007 * XXX The following needs to be set before ffs_truncate or 2008 * VOP_READ can be called. 2009 */ 2010 mp->mnt_stat.f_iosize = fs->fs_bsize; 2011 /* 2012 * Process each snapshot listed in the superblock. 2013 */ 2014 vp = NULL; 2015 lastvp = NULL; 2016 sn = NULL; 2017 for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++) { 2018 if (fs->fs_snapinum[snaploc] == 0) 2019 break; 2020 if ((error = ffs_vget(mp, fs->fs_snapinum[snaploc], 2021 LK_EXCLUSIVE, &vp)) != 0){ 2022 printf("ffs_snapshot_mount: vget failed %d\n", error); 2023 continue; 2024 } 2025 ip = VTOI(vp); 2026 if (vp->v_type != VREG) { 2027 reason = "non-file snapshot"; 2028 } else if (!IS_SNAPSHOT(ip)) { 2029 reason = "non-snapshot"; 2030 } else if (ip->i_size == 2031 lblktosize(fs, howmany(fs->fs_size, fs->fs_frag))) { 2032 reason = "old format snapshot"; 2033 (void)ffs_truncate(vp, (off_t)0, 0, NOCRED); 2034 (void)ffs_syncvnode(vp, MNT_WAIT, 0); 2035 } else { 2036 reason = NULL; 2037 } 2038 if (reason != NULL) { 2039 printf("ffs_snapshot_mount: %s inode %d\n", 2040 reason, fs->fs_snapinum[snaploc]); 2041 vput(vp); 2042 vp = NULL; 2043 for (loc = snaploc + 1; loc < FSMAXSNAP; loc++) { 2044 if (fs->fs_snapinum[loc] == 0) 2045 break; 2046 fs->fs_snapinum[loc - 1] = fs->fs_snapinum[loc]; 2047 } 2048 fs->fs_snapinum[loc - 1] = 0; 2049 snaploc--; 2050 continue; 2051 } 2052 /* 2053 * Acquire a lock on the snapdata structure, creating it if 2054 * necessary. 2055 */ 2056 sn = ffs_snapdata_acquire(devvp); 2057 /* 2058 * Change vnode to use shared snapshot lock instead of the 2059 * original private lock. 2060 */ 2061 vp->v_vnlock = &sn->sn_lock; 2062 lockmgr(&vp->v_lock, LK_RELEASE, NULL); 2063 /* 2064 * Link it onto the active snapshot list. 2065 */ 2066 VI_LOCK(devvp); 2067 if (ip->i_nextsnap.tqe_prev != 0) 2068 panic("ffs_snapshot_mount: %ju already on list", 2069 (uintmax_t)ip->i_number); 2070 else 2071 TAILQ_INSERT_TAIL(&sn->sn_head, ip, i_nextsnap); 2072 vp->v_vflag |= VV_SYSTEM; 2073 VI_UNLOCK(devvp); 2074 VOP_UNLOCK(vp); 2075 lastvp = vp; 2076 } 2077 vp = lastvp; 2078 /* 2079 * No usable snapshots found. 2080 */ 2081 if (sn == NULL || vp == NULL) 2082 return; 2083 /* 2084 * Allocate the space for the block hints list. We always want to 2085 * use the list from the newest snapshot. 2086 */ 2087 auio.uio_iov = &aiov; 2088 auio.uio_iovcnt = 1; 2089 aiov.iov_base = (void *)&snaplistsize; 2090 aiov.iov_len = sizeof(snaplistsize); 2091 auio.uio_resid = aiov.iov_len; 2092 auio.uio_offset = 2093 lblktosize(fs, howmany(fs->fs_size, fs->fs_frag)); 2094 auio.uio_segflg = UIO_SYSSPACE; 2095 auio.uio_rw = UIO_READ; 2096 auio.uio_td = td; 2097 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2098 if ((error = VOP_READ(vp, &auio, IO_UNIT, td->td_ucred)) != 0) { 2099 printf("ffs_snapshot_mount: read_1 failed %d\n", error); 2100 VOP_UNLOCK(vp); 2101 return; 2102 } 2103 snapblklist = malloc(snaplistsize * sizeof(daddr_t), 2104 M_UFSMNT, M_WAITOK); 2105 auio.uio_iovcnt = 1; 2106 aiov.iov_base = snapblklist; 2107 aiov.iov_len = snaplistsize * sizeof (daddr_t); 2108 auio.uio_resid = aiov.iov_len; 2109 auio.uio_offset -= sizeof(snaplistsize); 2110 if ((error = VOP_READ(vp, &auio, IO_UNIT, td->td_ucred)) != 0) { 2111 printf("ffs_snapshot_mount: read_2 failed %d\n", error); 2112 VOP_UNLOCK(vp); 2113 free(snapblklist, M_UFSMNT); 2114 return; 2115 } 2116 VOP_UNLOCK(vp); 2117 VI_LOCK(devvp); 2118 ASSERT_VOP_LOCKED(devvp, "ffs_snapshot_mount"); 2119 sn->sn_listsize = snaplistsize; 2120 sn->sn_blklist = (daddr_t *)snapblklist; 2121 devvp->v_vflag |= VV_COPYONWRITE; 2122 VI_UNLOCK(devvp); 2123 } 2124 2125 /* 2126 * Disassociate snapshot files when unmounting. 2127 */ 2128 void 2129 ffs_snapshot_unmount(mp) 2130 struct mount *mp; 2131 { 2132 struct vnode *devvp = VFSTOUFS(mp)->um_devvp; 2133 struct snapdata *sn; 2134 struct inode *xp; 2135 struct vnode *vp; 2136 2137 VI_LOCK(devvp); 2138 sn = devvp->v_rdev->si_snapdata; 2139 while (sn != NULL && (xp = TAILQ_FIRST(&sn->sn_head)) != NULL) { 2140 vp = ITOV(xp); 2141 TAILQ_REMOVE(&sn->sn_head, xp, i_nextsnap); 2142 xp->i_nextsnap.tqe_prev = 0; 2143 lockmgr(&sn->sn_lock, LK_INTERLOCK | LK_EXCLUSIVE, 2144 VI_MTX(devvp)); 2145 lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL); 2146 KASSERT(vp->v_vnlock == &sn->sn_lock, 2147 ("ffs_snapshot_unmount: lost lock mutation")); 2148 vp->v_vnlock = &vp->v_lock; 2149 lockmgr(&vp->v_lock, LK_RELEASE, NULL); 2150 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 2151 if (xp->i_effnlink > 0) 2152 vrele(vp); 2153 VI_LOCK(devvp); 2154 sn = devvp->v_rdev->si_snapdata; 2155 } 2156 try_free_snapdata(devvp); 2157 ASSERT_VOP_LOCKED(devvp, "ffs_snapshot_unmount"); 2158 } 2159 2160 /* 2161 * Check the buffer block to be belong to device buffer that shall be 2162 * locked after snaplk. devvp shall be locked on entry, and will be 2163 * leaved locked upon exit. 2164 */ 2165 static int 2166 ffs_bp_snapblk(devvp, bp) 2167 struct vnode *devvp; 2168 struct buf *bp; 2169 { 2170 struct snapdata *sn; 2171 struct fs *fs; 2172 ufs2_daddr_t lbn, *snapblklist; 2173 int lower, upper, mid; 2174 2175 ASSERT_VI_LOCKED(devvp, "ffs_bp_snapblk"); 2176 KASSERT(devvp->v_type == VCHR, ("Not a device %p", devvp)); 2177 sn = devvp->v_rdev->si_snapdata; 2178 if (sn == NULL || TAILQ_FIRST(&sn->sn_head) == NULL) 2179 return (0); 2180 fs = ITOFS(TAILQ_FIRST(&sn->sn_head)); 2181 lbn = fragstoblks(fs, dbtofsb(fs, bp->b_blkno)); 2182 snapblklist = sn->sn_blklist; 2183 upper = sn->sn_listsize - 1; 2184 lower = 1; 2185 while (lower <= upper) { 2186 mid = (lower + upper) / 2; 2187 if (snapblklist[mid] == lbn) 2188 break; 2189 if (snapblklist[mid] < lbn) 2190 lower = mid + 1; 2191 else 2192 upper = mid - 1; 2193 } 2194 if (lower <= upper) 2195 return (1); 2196 return (0); 2197 } 2198 2199 void 2200 ffs_bdflush(bo, bp) 2201 struct bufobj *bo; 2202 struct buf *bp; 2203 { 2204 struct thread *td; 2205 struct vnode *vp, *devvp; 2206 struct buf *nbp; 2207 int bp_bdskip; 2208 2209 if (bo->bo_dirty.bv_cnt <= dirtybufthresh) 2210 return; 2211 2212 td = curthread; 2213 vp = bp->b_vp; 2214 devvp = bo2vnode(bo); 2215 KASSERT(vp == devvp, ("devvp != vp %p %p", bo, bp)); 2216 2217 VI_LOCK(devvp); 2218 bp_bdskip = ffs_bp_snapblk(devvp, bp); 2219 if (bp_bdskip) 2220 bdwriteskip++; 2221 VI_UNLOCK(devvp); 2222 if (bo->bo_dirty.bv_cnt > dirtybufthresh + 10 && !bp_bdskip) { 2223 (void) VOP_FSYNC(vp, MNT_NOWAIT, td); 2224 altbufferflushes++; 2225 } else { 2226 BO_LOCK(bo); 2227 /* 2228 * Try to find a buffer to flush. 2229 */ 2230 TAILQ_FOREACH(nbp, &bo->bo_dirty.bv_hd, b_bobufs) { 2231 if ((nbp->b_vflags & BV_BKGRDINPROG) || 2232 BUF_LOCK(nbp, 2233 LK_EXCLUSIVE | LK_NOWAIT, NULL)) 2234 continue; 2235 if (bp == nbp) 2236 panic("bdwrite: found ourselves"); 2237 BO_UNLOCK(bo); 2238 /* 2239 * Don't countdeps with the bo lock 2240 * held. 2241 */ 2242 if (buf_countdeps(nbp, 0)) { 2243 BO_LOCK(bo); 2244 BUF_UNLOCK(nbp); 2245 continue; 2246 } 2247 if (bp_bdskip) { 2248 VI_LOCK(devvp); 2249 if (!ffs_bp_snapblk(vp, nbp)) { 2250 VI_UNLOCK(devvp); 2251 BO_LOCK(bo); 2252 BUF_UNLOCK(nbp); 2253 continue; 2254 } 2255 VI_UNLOCK(devvp); 2256 } 2257 if (nbp->b_flags & B_CLUSTEROK) { 2258 vfs_bio_awrite(nbp); 2259 } else { 2260 bremfree(nbp); 2261 bawrite(nbp); 2262 } 2263 dirtybufferflushes++; 2264 break; 2265 } 2266 if (nbp == NULL) 2267 BO_UNLOCK(bo); 2268 } 2269 } 2270 2271 /* 2272 * Check for need to copy block that is about to be written, 2273 * copying the block if necessary. 2274 */ 2275 int 2276 ffs_copyonwrite(devvp, bp) 2277 struct vnode *devvp; 2278 struct buf *bp; 2279 { 2280 struct snapdata *sn; 2281 struct buf *ibp, *cbp, *savedcbp = NULL; 2282 struct thread *td = curthread; 2283 struct fs *fs; 2284 struct inode *ip; 2285 struct vnode *vp = NULL; 2286 ufs2_daddr_t lbn, blkno, *snapblklist; 2287 int lower, upper, mid, indiroff, error = 0; 2288 int launched_async_io, prev_norunningbuf; 2289 long saved_runningbufspace; 2290 2291 if (devvp != bp->b_vp && IS_SNAPSHOT(VTOI(bp->b_vp))) 2292 return (0); /* Update on a snapshot file */ 2293 if (td->td_pflags & TDP_COWINPROGRESS) 2294 panic("ffs_copyonwrite: recursive call"); 2295 /* 2296 * First check to see if it is in the preallocated list. 2297 * By doing this check we avoid several potential deadlocks. 2298 */ 2299 VI_LOCK(devvp); 2300 sn = devvp->v_rdev->si_snapdata; 2301 if (sn == NULL || 2302 TAILQ_EMPTY(&sn->sn_head)) { 2303 VI_UNLOCK(devvp); 2304 return (0); /* No snapshot */ 2305 } 2306 ip = TAILQ_FIRST(&sn->sn_head); 2307 fs = ITOFS(ip); 2308 lbn = fragstoblks(fs, dbtofsb(fs, bp->b_blkno)); 2309 snapblklist = sn->sn_blklist; 2310 upper = sn->sn_listsize - 1; 2311 lower = 1; 2312 while (lower <= upper) { 2313 mid = (lower + upper) / 2; 2314 if (snapblklist[mid] == lbn) 2315 break; 2316 if (snapblklist[mid] < lbn) 2317 lower = mid + 1; 2318 else 2319 upper = mid - 1; 2320 } 2321 if (lower <= upper) { 2322 VI_UNLOCK(devvp); 2323 return (0); 2324 } 2325 launched_async_io = 0; 2326 prev_norunningbuf = td->td_pflags & TDP_NORUNNINGBUF; 2327 /* 2328 * Since I/O on bp isn't yet in progress and it may be blocked 2329 * for a long time waiting on snaplk, back it out of 2330 * runningbufspace, possibly waking other threads waiting for space. 2331 */ 2332 saved_runningbufspace = bp->b_runningbufspace; 2333 if (saved_runningbufspace != 0) 2334 runningbufwakeup(bp); 2335 /* 2336 * Not in the precomputed list, so check the snapshots. 2337 */ 2338 while (lockmgr(&sn->sn_lock, LK_INTERLOCK | LK_EXCLUSIVE | LK_SLEEPFAIL, 2339 VI_MTX(devvp)) != 0) { 2340 VI_LOCK(devvp); 2341 sn = devvp->v_rdev->si_snapdata; 2342 if (sn == NULL || 2343 TAILQ_EMPTY(&sn->sn_head)) { 2344 VI_UNLOCK(devvp); 2345 if (saved_runningbufspace != 0) { 2346 bp->b_runningbufspace = saved_runningbufspace; 2347 atomic_add_long(&runningbufspace, 2348 bp->b_runningbufspace); 2349 } 2350 return (0); /* Snapshot gone */ 2351 } 2352 } 2353 TAILQ_FOREACH(ip, &sn->sn_head, i_nextsnap) { 2354 vp = ITOV(ip); 2355 if (DOINGSOFTDEP(vp)) 2356 softdep_prealloc(vp, MNT_WAIT); 2357 /* 2358 * We ensure that everything of our own that needs to be 2359 * copied will be done at the time that ffs_snapshot is 2360 * called. Thus we can skip the check here which can 2361 * deadlock in doing the lookup in UFS_BALLOC. 2362 */ 2363 if (bp->b_vp == vp) 2364 continue; 2365 /* 2366 * Check to see if block needs to be copied. We do not have 2367 * to hold the snapshot lock while doing this lookup as it 2368 * will never require any additional allocations for the 2369 * snapshot inode. 2370 */ 2371 if (lbn < UFS_NDADDR) { 2372 blkno = DIP(ip, i_db[lbn]); 2373 } else { 2374 td->td_pflags |= TDP_COWINPROGRESS | TDP_NORUNNINGBUF; 2375 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn), 2376 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp); 2377 td->td_pflags &= ~TDP_COWINPROGRESS; 2378 if (error) 2379 break; 2380 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs); 2381 if (I_IS_UFS1(ip)) 2382 blkno=((ufs1_daddr_t *)(ibp->b_data))[indiroff]; 2383 else 2384 blkno=((ufs2_daddr_t *)(ibp->b_data))[indiroff]; 2385 bqrelse(ibp); 2386 } 2387 #ifdef INVARIANTS 2388 if (blkno == BLK_SNAP && bp->b_lblkno >= 0) 2389 panic("ffs_copyonwrite: bad copy block"); 2390 #endif 2391 if (blkno != 0) 2392 continue; 2393 /* 2394 * Allocate the block into which to do the copy. Since 2395 * multiple processes may all try to copy the same block, 2396 * we have to recheck our need to do a copy if we sleep 2397 * waiting for the lock. 2398 * 2399 * Because all snapshots on a filesystem share a single 2400 * lock, we ensure that we will never be in competition 2401 * with another process to allocate a block. 2402 */ 2403 td->td_pflags |= TDP_COWINPROGRESS | TDP_NORUNNINGBUF; 2404 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn), 2405 fs->fs_bsize, KERNCRED, 0, &cbp); 2406 td->td_pflags &= ~TDP_COWINPROGRESS; 2407 if (error) 2408 break; 2409 #ifdef DIAGNOSTIC 2410 if (snapdebug) { 2411 printf("Copyonwrite: snapino %ju lbn %jd for ", 2412 (uintmax_t)ip->i_number, (intmax_t)lbn); 2413 if (bp->b_vp == devvp) 2414 printf("fs metadata"); 2415 else 2416 printf("inum %ju", 2417 (uintmax_t)VTOI(bp->b_vp)->i_number); 2418 printf(" lblkno %jd to blkno %jd\n", 2419 (intmax_t)bp->b_lblkno, (intmax_t)cbp->b_blkno); 2420 } 2421 #endif 2422 /* 2423 * If we have already read the old block contents, then 2424 * simply copy them to the new block. Note that we need 2425 * to synchronously write snapshots that have not been 2426 * unlinked, and hence will be visible after a crash, 2427 * to ensure their integrity. At a minimum we ensure the 2428 * integrity of the filesystem metadata, but use the 2429 * dopersistence sysctl-setable flag to decide on the 2430 * persistence needed for file content data. 2431 */ 2432 if (savedcbp != NULL) { 2433 bcopy(savedcbp->b_data, cbp->b_data, fs->fs_bsize); 2434 bawrite(cbp); 2435 if ((devvp == bp->b_vp || bp->b_vp->v_type == VDIR || 2436 dopersistence) && ip->i_effnlink > 0) 2437 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 2438 else 2439 launched_async_io = 1; 2440 continue; 2441 } 2442 /* 2443 * Otherwise, read the old block contents into the buffer. 2444 */ 2445 if ((error = readblock(vp, cbp, lbn)) != 0) { 2446 bzero(cbp->b_data, fs->fs_bsize); 2447 bawrite(cbp); 2448 if ((devvp == bp->b_vp || bp->b_vp->v_type == VDIR || 2449 dopersistence) && ip->i_effnlink > 0) 2450 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 2451 else 2452 launched_async_io = 1; 2453 break; 2454 } 2455 savedcbp = cbp; 2456 } 2457 /* 2458 * Note that we need to synchronously write snapshots that 2459 * have not been unlinked, and hence will be visible after 2460 * a crash, to ensure their integrity. At a minimum we 2461 * ensure the integrity of the filesystem metadata, but 2462 * use the dopersistence sysctl-setable flag to decide on 2463 * the persistence needed for file content data. 2464 */ 2465 if (savedcbp) { 2466 vp = savedcbp->b_vp; 2467 bawrite(savedcbp); 2468 if ((devvp == bp->b_vp || bp->b_vp->v_type == VDIR || 2469 dopersistence) && VTOI(vp)->i_effnlink > 0) 2470 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT); 2471 else 2472 launched_async_io = 1; 2473 } 2474 lockmgr(vp->v_vnlock, LK_RELEASE, NULL); 2475 td->td_pflags = (td->td_pflags & ~TDP_NORUNNINGBUF) | 2476 prev_norunningbuf; 2477 if (launched_async_io && (td->td_pflags & TDP_NORUNNINGBUF) == 0) 2478 waitrunningbufspace(); 2479 /* 2480 * I/O on bp will now be started, so count it in runningbufspace. 2481 */ 2482 if (saved_runningbufspace != 0) { 2483 bp->b_runningbufspace = saved_runningbufspace; 2484 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 2485 } 2486 return (error); 2487 } 2488 2489 /* 2490 * sync snapshots to force freework records waiting on snapshots to claim 2491 * blocks to free. 2492 */ 2493 void 2494 ffs_sync_snap(mp, waitfor) 2495 struct mount *mp; 2496 int waitfor; 2497 { 2498 struct snapdata *sn; 2499 struct vnode *devvp; 2500 struct vnode *vp; 2501 struct inode *ip; 2502 2503 devvp = VFSTOUFS(mp)->um_devvp; 2504 if ((devvp->v_vflag & VV_COPYONWRITE) == 0) 2505 return; 2506 for (;;) { 2507 VI_LOCK(devvp); 2508 sn = devvp->v_rdev->si_snapdata; 2509 if (sn == NULL) { 2510 VI_UNLOCK(devvp); 2511 return; 2512 } 2513 if (lockmgr(&sn->sn_lock, 2514 LK_INTERLOCK | LK_EXCLUSIVE | LK_SLEEPFAIL, 2515 VI_MTX(devvp)) == 0) 2516 break; 2517 } 2518 TAILQ_FOREACH(ip, &sn->sn_head, i_nextsnap) { 2519 vp = ITOV(ip); 2520 ffs_syncvnode(vp, waitfor, NO_INO_UPDT); 2521 } 2522 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 2523 } 2524 2525 /* 2526 * Read the specified block into the given buffer. 2527 * Much of this boiler-plate comes from bwrite(). 2528 */ 2529 static int 2530 readblock(vp, bp, lbn) 2531 struct vnode *vp; 2532 struct buf *bp; 2533 ufs2_daddr_t lbn; 2534 { 2535 struct inode *ip; 2536 struct bio *bip; 2537 struct fs *fs; 2538 2539 ip = VTOI(vp); 2540 fs = ITOFS(ip); 2541 2542 bip = g_alloc_bio(); 2543 bip->bio_cmd = BIO_READ; 2544 bip->bio_offset = dbtob(fsbtodb(fs, blkstofrags(fs, lbn))); 2545 bip->bio_data = bp->b_data; 2546 bip->bio_length = bp->b_bcount; 2547 bip->bio_done = NULL; 2548 2549 g_io_request(bip, ITODEVVP(ip)->v_bufobj.bo_private); 2550 bp->b_error = biowait(bip, "snaprdb"); 2551 g_destroy_bio(bip); 2552 return (bp->b_error); 2553 } 2554 2555 #endif 2556 2557 /* 2558 * Process file deletes that were deferred by ufs_inactive() due to 2559 * the file system being suspended. Transfer IN_LAZYACCESS into 2560 * IN_MODIFIED for vnodes that were accessed during suspension. 2561 */ 2562 void 2563 process_deferred_inactive(struct mount *mp) 2564 { 2565 struct vnode *vp, *mvp; 2566 struct inode *ip; 2567 int error; 2568 2569 (void) vn_start_secondary_write(NULL, &mp, V_WAIT); 2570 loop: 2571 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 2572 /* 2573 * IN_LAZYACCESS is checked here without holding any 2574 * vnode lock, but this flag is set only while holding 2575 * vnode interlock. 2576 */ 2577 if (vp->v_type == VNON || 2578 ((VTOI(vp)->i_flag & IN_LAZYACCESS) == 0 && 2579 ((vp->v_iflag & VI_OWEINACT) == 0 || vp->v_usecount > 0))) { 2580 VI_UNLOCK(vp); 2581 continue; 2582 } 2583 vholdl(vp); 2584 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 2585 if (error != 0) { 2586 vdrop(vp); 2587 if (error == ENOENT) 2588 continue; /* vnode recycled */ 2589 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); 2590 goto loop; 2591 } 2592 ip = VTOI(vp); 2593 if ((ip->i_flag & IN_LAZYACCESS) != 0) { 2594 ip->i_flag &= ~IN_LAZYACCESS; 2595 UFS_INODE_SET_FLAG(ip, IN_MODIFIED); 2596 } 2597 VI_LOCK(vp); 2598 vinactive(vp); 2599 VI_UNLOCK(vp); 2600 VOP_UNLOCK(vp); 2601 vdrop(vp); 2602 } 2603 vn_finished_secondary_write(mp); 2604 } 2605 2606 #ifndef NO_FFS_SNAPSHOT 2607 2608 static struct snapdata * 2609 ffs_snapdata_alloc(void) 2610 { 2611 struct snapdata *sn; 2612 2613 /* 2614 * Fetch a snapdata from the free list if there is one available. 2615 */ 2616 mtx_lock(&snapfree_lock); 2617 sn = LIST_FIRST(&snapfree); 2618 if (sn != NULL) 2619 LIST_REMOVE(sn, sn_link); 2620 mtx_unlock(&snapfree_lock); 2621 if (sn != NULL) 2622 return (sn); 2623 /* 2624 * If there were no free snapdatas allocate one. 2625 */ 2626 sn = malloc(sizeof *sn, M_UFSMNT, M_WAITOK | M_ZERO); 2627 TAILQ_INIT(&sn->sn_head); 2628 lockinit(&sn->sn_lock, PVFS, "snaplk", VLKTIMEOUT, 2629 LK_CANRECURSE | LK_NOSHARE); 2630 return (sn); 2631 } 2632 2633 /* 2634 * The snapdata is never freed because we can not be certain that 2635 * there are no threads sleeping on the snap lock. Persisting 2636 * them permanently avoids costly synchronization in ffs_lock(). 2637 */ 2638 static void 2639 ffs_snapdata_free(struct snapdata *sn) 2640 { 2641 mtx_lock(&snapfree_lock); 2642 LIST_INSERT_HEAD(&snapfree, sn, sn_link); 2643 mtx_unlock(&snapfree_lock); 2644 } 2645 2646 /* Try to free snapdata associated with devvp */ 2647 static void 2648 try_free_snapdata(struct vnode *devvp) 2649 { 2650 struct snapdata *sn; 2651 ufs2_daddr_t *snapblklist; 2652 2653 ASSERT_VI_LOCKED(devvp, "try_free_snapdata"); 2654 sn = devvp->v_rdev->si_snapdata; 2655 2656 if (sn == NULL || TAILQ_FIRST(&sn->sn_head) != NULL || 2657 (devvp->v_vflag & VV_COPYONWRITE) == 0) { 2658 VI_UNLOCK(devvp); 2659 return; 2660 } 2661 2662 devvp->v_rdev->si_snapdata = NULL; 2663 devvp->v_vflag &= ~VV_COPYONWRITE; 2664 lockmgr(&sn->sn_lock, LK_DRAIN|LK_INTERLOCK, VI_MTX(devvp)); 2665 snapblklist = sn->sn_blklist; 2666 sn->sn_blklist = NULL; 2667 sn->sn_listsize = 0; 2668 lockmgr(&sn->sn_lock, LK_RELEASE, NULL); 2669 if (snapblklist != NULL) 2670 free(snapblklist, M_UFSMNT); 2671 ffs_snapdata_free(sn); 2672 } 2673 2674 static struct snapdata * 2675 ffs_snapdata_acquire(struct vnode *devvp) 2676 { 2677 struct snapdata *nsn, *sn; 2678 int error; 2679 2680 /* 2681 * Allocate a free snapdata. This is done before acquiring the 2682 * devvp lock to avoid allocation while the devvp interlock is 2683 * held. 2684 */ 2685 nsn = ffs_snapdata_alloc(); 2686 2687 for (;;) { 2688 VI_LOCK(devvp); 2689 sn = devvp->v_rdev->si_snapdata; 2690 if (sn == NULL) { 2691 /* 2692 * This is the first snapshot on this 2693 * filesystem and we use our pre-allocated 2694 * snapdata. Publish sn with the sn_lock 2695 * owned by us, to avoid the race. 2696 */ 2697 error = lockmgr(&nsn->sn_lock, LK_EXCLUSIVE | 2698 LK_NOWAIT, NULL); 2699 if (error != 0) 2700 panic("leaked sn, lockmgr error %d", error); 2701 sn = devvp->v_rdev->si_snapdata = nsn; 2702 VI_UNLOCK(devvp); 2703 nsn = NULL; 2704 break; 2705 } 2706 2707 /* 2708 * There is a snapshots which already exists on this 2709 * filesystem, grab a reference to the common lock. 2710 */ 2711 error = lockmgr(&sn->sn_lock, LK_INTERLOCK | 2712 LK_EXCLUSIVE | LK_SLEEPFAIL, VI_MTX(devvp)); 2713 if (error == 0) 2714 break; 2715 } 2716 2717 /* 2718 * Free any unused snapdata. 2719 */ 2720 if (nsn != NULL) 2721 ffs_snapdata_free(nsn); 2722 2723 return (sn); 2724 } 2725 2726 #endif 2727