2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright 2000 Marshall Kirk McKusick. All Rights Reserved.
6 * Further information about snapshots can be obtained from:
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
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
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.
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
35 * @(#)ffs_snapshot.c 8.11 (McKusick) 7/23/00
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
41 #include "opt_quota.h"
43 #include <sys/param.h>
44 #include <sys/kernel.h>
45 #include <sys/systm.h>
49 #include <sys/fcntl.h>
51 #include <sys/namei.h>
52 #include <sys/sched.h>
54 #include <sys/malloc.h>
55 #include <sys/mount.h>
56 #include <sys/resource.h>
57 #include <sys/resourcevar.h>
58 #include <sys/rwlock.h>
59 #include <sys/vnode.h>
61 #include <geom/geom.h>
63 #include <ufs/ufs/extattr.h>
64 #include <ufs/ufs/quota.h>
65 #include <ufs/ufs/ufsmount.h>
66 #include <ufs/ufs/inode.h>
67 #include <ufs/ufs/ufs_extern.h>
69 #include <ufs/ffs/fs.h>
70 #include <ufs/ffs/ffs_extern.h>
72 #define KERNCRED thread0.td_ucred
77 #ifdef NO_FFS_SNAPSHOT
79 ffs_snapshot(mp, snapfile)
87 ffs_snapblkfree(fs, devvp, bno, size, inum, vtype, wkhd)
94 struct workhead *wkhd;
106 ffs_snapshot_mount(mp)
112 ffs_snapshot_unmount(mp)
124 ffs_copyonwrite(devvp, bp)
132 ffs_sync_snap(mp, waitfor)
139 FEATURE(ffs_snapshot, "FFS snapshot support");
141 LIST_HEAD(, snapdata) snapfree;
142 static struct mtx snapfree_lock;
143 MTX_SYSINIT(ffs_snapfree, &snapfree_lock, "snapdata free list", MTX_DEF);
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 *);
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.
186 int dopersistence = 0;
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,
199 * Create a snapshot file and initialize it for the filesystem.
202 ffs_snapshot(mp, snapfile)
206 ufs2_daddr_t numblks, blkno, *blkp, *snapblklist;
207 int error, cg, snaploc;
208 int i, size, len, loc;
209 ufs2_daddr_t blockno;
211 struct timespec starttime = {0, 0}, endtime;
213 long redo = 0, snaplistsize = 0;
216 struct fs *copy_fs = NULL, *fs;
217 struct thread *td = curthread;
218 struct inode *ip, *xp;
219 struct buf *bp, *nbp, *ibp;
223 struct vnode *vp, *xvp, *mvp, *devvp;
227 struct ufsmount *ump;
233 * At the moment, journaled soft updates cannot support
236 if (MOUNTEDSUJ(mp)) {
237 vfs_mount_error(mp, "%s: Snapshots are not yet supported when "
238 "running with journaled soft updates", fs->fs_fsmnt);
245 * Need to serialize access to snapshot code per filesystem.
248 * Assign a snapshot slot in the superblock.
251 for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++)
252 if (fs->fs_snapinum[snaploc] == 0)
255 if (snaploc == FSMAXSNAP)
258 * Create the snapshot file.
261 NDINIT(&nd, CREATE, LOCKPARENT | LOCKLEAF | NOCACHE, UIO_SYSSPACE,
263 if ((error = namei(&nd)) != 0)
265 if (nd.ni_vp != NULL) {
269 if (nd.ni_dvp->v_mount != mp)
272 NDFREE(&nd, NDF_ONLY_PNBUF);
273 if (nd.ni_dvp == nd.ni_vp)
281 vat.va_mode = S_IRUSR;
282 vat.va_vaflags |= VA_EXCLUSIVE;
283 if (VOP_GETWRITEMOUNT(nd.ni_dvp, &wrtmp))
286 panic("ffs_snapshot: mount mismatch");
288 if (vn_start_write(NULL, &wrtmp, V_NOWAIT) != 0) {
289 NDFREE(&nd, NDF_ONLY_PNBUF);
291 if ((error = vn_start_write(NULL, &wrtmp,
292 V_XSLEEP | PCATCH)) != 0)
296 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vat);
297 VOP_UNLOCK(nd.ni_dvp, 0);
299 NDFREE(&nd, NDF_ONLY_PNBUF);
300 vn_finished_write(wrtmp);
305 vnode_create_vobject(nd.ni_vp, fs->fs_size, td);
306 vp->v_vflag |= VV_SYSTEM;
308 devvp = ITODEVVP(ip);
310 * Allocate and copy the last block contents so as to be able
311 * to set size to that of the filesystem.
313 numblks = howmany(fs->fs_size, fs->fs_frag);
314 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(numblks - 1)),
315 fs->fs_bsize, KERNCRED, BA_CLRBUF, &bp);
318 ip->i_size = lblktosize(fs, (off_t)numblks);
319 DIP_SET(ip, i_size, ip->i_size);
320 ip->i_flag |= IN_CHANGE | IN_UPDATE;
321 error = readblock(vp, bp, numblks - 1);
326 * Preallocate critical data structures so that we can copy
327 * them in without further allocation after we suspend all
328 * operations on the filesystem. We would like to just release
329 * the allocated buffers without writing them since they will
330 * be filled in below once we are ready to go, but this upsets
331 * the soft update code, so we go ahead and write the new buffers.
333 * Allocate all indirect blocks and mark all of them as not
334 * needing to be copied.
336 for (blkno = UFS_NDADDR; blkno < numblks; blkno += NINDIR(fs)) {
337 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)blkno),
338 fs->fs_bsize, td->td_ucred, BA_METAONLY, &ibp);
344 * Allocate copies for the superblock and its summary information.
346 error = UFS_BALLOC(vp, fs->fs_sblockloc, fs->fs_sbsize, KERNCRED,
351 blkno = fragstoblks(fs, fs->fs_csaddr);
352 len = howmany(fs->fs_cssize, fs->fs_bsize);
353 for (loc = 0; loc < len; loc++) {
354 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(blkno + loc)),
355 fs->fs_bsize, KERNCRED, 0, &nbp);
361 * Allocate all cylinder group blocks.
363 for (cg = 0; cg < fs->fs_ncg; cg++) {
364 error = UFS_BALLOC(vp, lfragtosize(fs, cgtod(fs, cg)),
365 fs->fs_bsize, KERNCRED, 0, &nbp);
370 ffs_syncvnode(vp, MNT_WAIT, 0);
373 * Copy all the cylinder group maps. Although the
374 * filesystem is still active, we hope that only a few
375 * cylinder groups will change between now and when we
376 * suspend operations. Thus, we will be able to quickly
377 * touch up the few cylinder groups that changed during
378 * the suspension period.
380 len = howmany(fs->fs_ncg, NBBY);
381 space = malloc(len, M_DEVBUF, M_WAITOK|M_ZERO);
383 fs->fs_active = space;
385 for (cg = 0; cg < fs->fs_ncg; cg++) {
386 error = UFS_BALLOC(vp, lfragtosize(fs, cgtod(fs, cg)),
387 fs->fs_bsize, KERNCRED, 0, &nbp);
390 error = cgaccount(cg, vp, nbp, 1);
393 ffs_syncvnode(vp, MNT_WAIT, 0);
398 * Change inode to snapshot type file.
400 ip->i_flags |= SF_SNAPSHOT;
401 DIP_SET(ip, i_flags, ip->i_flags);
402 ip->i_flag |= IN_CHANGE | IN_UPDATE;
404 * Ensure that the snapshot is completely on disk.
405 * Since we have marked it as a snapshot it is safe to
406 * unlock it as no process will be allowed to write to it.
408 if ((error = ffs_syncvnode(vp, MNT_WAIT, 0)) != 0)
412 * All allocations are done, so we can now snapshot the system.
414 * Recind nice scheduling while running with the filesystem suspended.
416 if (td->td_proc->p_nice > 0) {
421 saved_nice = p->p_nice;
426 * Suspend operation on filesystem.
429 vn_finished_write(wrtmp);
430 if ((error = vfs_write_suspend(vp->v_mount, 0)) != 0) {
431 vn_start_write(NULL, &wrtmp, V_WAIT);
432 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
435 if (mp->mnt_kern_flag & MNTK_SUSPENDED)
437 vn_start_write(NULL, &wrtmp, V_WAIT);
439 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
440 if (ip->i_effnlink == 0) {
441 error = ENOENT; /* Snapshot file unlinked */
444 if (collectsnapstats)
445 nanotime(&starttime);
447 /* The last block might have changed. Copy it again to be sure. */
448 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(numblks - 1)),
449 fs->fs_bsize, KERNCRED, BA_CLRBUF, &bp);
452 error = readblock(vp, bp, numblks - 1);
453 bp->b_flags |= B_VALIDSUSPWRT;
458 * First, copy all the cylinder group maps that have changed.
460 for (cg = 0; cg < fs->fs_ncg; cg++) {
461 if ((ACTIVECGNUM(fs, cg) & ACTIVECGOFF(cg)) != 0)
464 error = UFS_BALLOC(vp, lfragtosize(fs, cgtod(fs, cg)),
465 fs->fs_bsize, KERNCRED, 0, &nbp);
468 error = cgaccount(cg, vp, nbp, 2);
474 * Grab a copy of the superblock and its summary information.
475 * We delay writing it until the suspension is released below.
477 copy_fs = malloc((u_long)fs->fs_bsize, M_UFSMNT, M_WAITOK);
478 bcopy(fs, copy_fs, fs->fs_sbsize);
479 if ((fs->fs_flags & (FS_UNCLEAN | FS_NEEDSFSCK)) == 0)
480 copy_fs->fs_clean = 1;
481 size = fs->fs_bsize < SBLOCKSIZE ? fs->fs_bsize : SBLOCKSIZE;
482 if (fs->fs_sbsize < size)
483 bzero(&((char *)copy_fs)[fs->fs_sbsize],
484 size - fs->fs_sbsize);
485 size = blkroundup(fs, fs->fs_cssize);
486 if (fs->fs_contigsumsize > 0)
487 size += fs->fs_ncg * sizeof(int32_t);
488 space = malloc((u_long)size, M_UFSMNT, M_WAITOK);
489 copy_fs->fs_csp = space;
490 bcopy(fs->fs_csp, copy_fs->fs_csp, fs->fs_cssize);
491 space = (char *)space + fs->fs_cssize;
492 loc = howmany(fs->fs_cssize, fs->fs_fsize);
493 i = fs->fs_frag - loc % fs->fs_frag;
494 len = (i == fs->fs_frag) ? 0 : i * fs->fs_fsize;
496 if ((error = bread(devvp, fsbtodb(fs, fs->fs_csaddr + loc),
497 len, KERNCRED, &bp)) != 0) {
499 free(copy_fs->fs_csp, M_UFSMNT);
500 free(copy_fs, M_UFSMNT);
504 bcopy(bp->b_data, space, (u_int)len);
505 space = (char *)space + len;
506 bp->b_flags |= B_INVAL | B_NOCACHE;
509 if (fs->fs_contigsumsize > 0) {
510 copy_fs->fs_maxcluster = lp = space;
511 for (i = 0; i < fs->fs_ncg; i++)
512 *lp++ = fs->fs_contigsumsize;
515 * We must check for active files that have been unlinked
516 * (e.g., with a zero link count). We have to expunge all
517 * trace of these files from the snapshot so that they are
518 * not reclaimed prematurely by fsck or unnecessarily dumped.
519 * We turn off the MNTK_SUSPENDED flag to avoid a panic from
520 * spec_strategy about writing on a suspended filesystem.
521 * Note that we skip unlinked snapshot files as they will
522 * be handled separately below.
524 * We also calculate the needed size for the snapshot list.
526 snaplistsize = fs->fs_ncg + howmany(fs->fs_cssize, fs->fs_bsize) +
527 FSMAXSNAP + 1 /* superblock */ + 1 /* last block */ + 1 /* size */;
529 mp->mnt_kern_flag &= ~MNTK_SUSPENDED;
532 MNT_VNODE_FOREACH_ALL(xvp, mp, mvp) {
533 if ((xvp->v_usecount == 0 &&
534 (xvp->v_iflag & (VI_OWEINACT | VI_DOINGINACT)) == 0) ||
535 xvp->v_type == VNON ||
536 IS_SNAPSHOT(VTOI(xvp))) {
541 * We can skip parent directory vnode because it must have
542 * this snapshot file in it.
544 if (xvp == nd.ni_dvp) {
549 if (vn_lock(xvp, LK_EXCLUSIVE | LK_INTERLOCK) != 0) {
550 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
555 if (xvp->v_usecount == 0 &&
556 (xvp->v_iflag & (VI_OWEINACT | VI_DOINGINACT)) == 0) {
564 vn_printf(xvp, "ffs_snapshot: busy vnode ");
565 if (VOP_GETATTR(xvp, &vat, td->td_ucred) == 0 &&
572 if (ffs_checkfreefile(copy_fs, vp, xp->i_number)) {
578 * If there is a fragment, clear it here.
581 loc = howmany(xp->i_size, fs->fs_bsize) - 1;
582 if (loc < UFS_NDADDR) {
583 len = fragroundup(fs, blkoff(fs, xp->i_size));
584 if (len != 0 && len < fs->fs_bsize) {
585 ffs_blkfree(ump, copy_fs, vp,
586 DIP(xp, i_db[loc]), len, xp->i_number,
587 xvp->v_type, NULL, SINGLETON_KEY);
588 blkno = DIP(xp, i_db[loc]);
589 DIP_SET(xp, i_db[loc], 0);
594 error = expunge_ufs1(vp, xp, copy_fs, fullacct_ufs1,
597 error = expunge_ufs2(vp, xp, copy_fs, fullacct_ufs2,
600 DIP_SET(xp, i_db[loc], blkno);
602 error = ffs_freefile(ump, copy_fs, vp, xp->i_number,
607 free(copy_fs->fs_csp, M_UFSMNT);
608 free(copy_fs, M_UFSMNT);
610 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
615 * Erase the journal file from the snapshot.
617 if (fs->fs_flags & FS_SUJ) {
618 error = softdep_journal_lookup(mp, &xvp);
620 free(copy_fs->fs_csp, M_UFSMNT);
621 free(copy_fs, M_UFSMNT);
627 error = expunge_ufs1(vp, xp, copy_fs, fullacct_ufs1,
630 error = expunge_ufs2(vp, xp, copy_fs, fullacct_ufs2,
635 * Acquire a lock on the snapdata structure, creating it if necessary.
637 sn = ffs_snapdata_acquire(devvp);
639 * Change vnode to use shared snapshot lock instead of the original
642 vp->v_vnlock = &sn->sn_lock;
643 lockmgr(&vp->v_lock, LK_RELEASE, NULL);
644 xp = TAILQ_FIRST(&sn->sn_head);
646 * If this is the first snapshot on this filesystem, then we need
647 * to allocate the space for the list of preallocated snapshot blocks.
648 * This list will be refined below, but this preliminary one will
649 * keep us out of deadlock until the full one is ready.
652 snapblklist = malloc(snaplistsize * sizeof(daddr_t),
654 blkp = &snapblklist[1];
655 *blkp++ = lblkno(fs, fs->fs_sblockloc);
656 blkno = fragstoblks(fs, fs->fs_csaddr);
657 for (cg = 0; cg < fs->fs_ncg; cg++) {
658 if (fragstoblks(fs, cgtod(fs, cg) > blkno))
660 *blkp++ = fragstoblks(fs, cgtod(fs, cg));
662 len = howmany(fs->fs_cssize, fs->fs_bsize);
663 for (loc = 0; loc < len; loc++)
664 *blkp++ = blkno + loc;
665 for (; cg < fs->fs_ncg; cg++)
666 *blkp++ = fragstoblks(fs, cgtod(fs, cg));
667 snapblklist[0] = blkp - snapblklist;
669 if (sn->sn_blklist != NULL)
670 panic("ffs_snapshot: non-empty list");
671 sn->sn_blklist = snapblklist;
672 sn->sn_listsize = blkp - snapblklist;
676 * Record snapshot inode. Since this is the newest snapshot,
677 * it must be placed at the end of the list.
680 fs->fs_snapinum[snaploc] = ip->i_number;
681 if (ip->i_nextsnap.tqe_prev != 0)
682 panic("ffs_snapshot: %ju already on list",
683 (uintmax_t)ip->i_number);
684 TAILQ_INSERT_TAIL(&sn->sn_head, ip, i_nextsnap);
685 devvp->v_vflag |= VV_COPYONWRITE;
687 ASSERT_VOP_LOCKED(vp, "ffs_snapshot vp");
689 KASSERT((sn != NULL && copy_fs != NULL && error == 0) ||
690 (sn == NULL && copy_fs == NULL && error != 0),
691 ("email phk@ and mckusick@"));
693 * Resume operation on filesystem.
695 vfs_write_resume(vp->v_mount, VR_START_WRITE | VR_NO_SUSPCLR);
696 if (collectsnapstats && starttime.tv_sec > 0) {
698 timespecsub(&endtime, &starttime, &endtime);
699 printf("%s: suspended %ld.%03ld sec, redo %ld of %d\n",
700 vp->v_mount->mnt_stat.f_mntonname, (long)endtime.tv_sec,
701 endtime.tv_nsec / 1000000, redo, fs->fs_ncg);
706 * Copy allocation information from all the snapshots in
707 * this snapshot and then expunge them from its view.
709 TAILQ_FOREACH(xp, &sn->sn_head, i_nextsnap) {
713 error = expunge_ufs1(vp, xp, fs, snapacct_ufs1,
716 error = expunge_ufs2(vp, xp, fs, snapacct_ufs2,
718 if (error == 0 && xp->i_effnlink == 0) {
719 error = ffs_freefile(ump,
726 fs->fs_snapinum[snaploc] = 0;
731 * Allocate space for the full list of preallocated snapshot blocks.
733 snapblklist = malloc(snaplistsize * sizeof(daddr_t),
735 ip->i_snapblklist = &snapblklist[1];
737 * Expunge the blocks used by the snapshots from the set of
738 * blocks marked as used in the snapshot bitmaps. Also, collect
739 * the list of allocated blocks in i_snapblklist.
742 error = expunge_ufs1(vp, ip, copy_fs, mapacct_ufs1,
745 error = expunge_ufs2(vp, ip, copy_fs, mapacct_ufs2,
748 fs->fs_snapinum[snaploc] = 0;
749 free(snapblklist, M_UFSMNT);
752 if (snaplistsize < ip->i_snapblklist - snapblklist)
753 panic("ffs_snapshot: list too small");
754 snaplistsize = ip->i_snapblklist - snapblklist;
755 snapblklist[0] = snaplistsize;
756 ip->i_snapblklist = 0;
758 * Write out the list of allocated blocks to the end of the snapshot.
760 auio.uio_iov = &aiov;
762 aiov.iov_base = (void *)snapblklist;
763 aiov.iov_len = snaplistsize * sizeof(daddr_t);
764 auio.uio_resid = aiov.iov_len;
765 auio.uio_offset = ip->i_size;
766 auio.uio_segflg = UIO_SYSSPACE;
767 auio.uio_rw = UIO_WRITE;
769 if ((error = VOP_WRITE(vp, &auio, IO_UNIT, td->td_ucred)) != 0) {
770 fs->fs_snapinum[snaploc] = 0;
771 free(snapblklist, M_UFSMNT);
775 * Write the superblock and its summary information
778 blkno = fragstoblks(fs, fs->fs_csaddr);
779 len = howmany(fs->fs_cssize, fs->fs_bsize);
780 space = copy_fs->fs_csp;
781 for (loc = 0; loc < len; loc++) {
782 error = bread(vp, blkno + loc, fs->fs_bsize, KERNCRED, &nbp);
785 fs->fs_snapinum[snaploc] = 0;
786 free(snapblklist, M_UFSMNT);
789 bcopy(space, nbp->b_data, fs->fs_bsize);
790 space = (char *)space + fs->fs_bsize;
793 error = bread(vp, lblkno(fs, fs->fs_sblockloc), fs->fs_bsize,
798 loc = blkoff(fs, fs->fs_sblockloc);
799 copy_fs->fs_ckhash = ffs_calc_sbhash(copy_fs);
800 bcopy((char *)copy_fs, &nbp->b_data[loc], (u_int)fs->fs_sbsize);
804 * As this is the newest list, it is the most inclusive, so
805 * should replace the previous list.
808 space = sn->sn_blklist;
809 sn->sn_blklist = snapblklist;
810 sn->sn_listsize = snaplistsize;
813 free(space, M_UFSMNT);
815 * Preallocate all the direct blocks in the snapshot inode so
816 * that we never have to write the inode itself to commit an
817 * update to the contents of the snapshot. Note that once
818 * created, the size of the snapshot will never change, so
819 * there will never be a need to write the inode except to
820 * update the non-integrity-critical time fields and
821 * allocated-block count.
823 for (blockno = 0; blockno < UFS_NDADDR; blockno++) {
824 if (DIP(ip, i_db[blockno]) != 0)
826 error = UFS_BALLOC(vp, lblktosize(fs, blockno),
827 fs->fs_bsize, KERNCRED, BA_CLRBUF, &bp);
830 error = readblock(vp, bp, blockno);
836 free(copy_fs->fs_csp, M_UFSMNT);
837 free(copy_fs, M_UFSMNT);
840 NDFREE(&nd, NDF_ONLY_PNBUF);
841 if (saved_nice > 0) {
846 sched_nice(td->td_proc, saved_nice);
847 PROC_UNLOCK(td->td_proc);
850 if (fs->fs_active != 0) {
851 free(fs->fs_active, M_DEVBUF);
856 mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | (flag & ~MNT_QUOTA);
859 (void) ffs_truncate(vp, (off_t)0, 0, NOCRED);
860 (void) ffs_syncvnode(vp, MNT_WAIT, 0);
866 vn_finished_write(wrtmp);
867 process_deferred_inactive(mp);
872 * Copy a cylinder group map. All the unallocated blocks are marked
873 * BLK_NOCOPY so that the snapshot knows that it need not copy them
874 * if they are later written. If passno is one, then this is a first
875 * pass, so only setting needs to be done. If passno is 2, then this
876 * is a revision to a previous pass which must be undone as the
877 * replacement pass is done.
880 cgaccount(cg, vp, nbp, passno)
886 struct buf *bp, *ibp;
890 ufs2_daddr_t base, numblks;
891 int error, len, loc, indiroff;
895 if ((error = ffs_getcg(fs, ITODEVVP(ip), cg, &bp, &cgp)) != 0)
897 UFS_LOCK(ITOUMP(ip));
900 * Recomputation of summary information might not have been performed
901 * at mount time. Sync up summary information for current cylinder
902 * group while data is in memory to ensure that result of background
903 * fsck is slightly more consistent.
905 fs->fs_cs(fs, cg) = cgp->cg_cs;
906 UFS_UNLOCK(ITOUMP(ip));
907 bcopy(bp->b_data, nbp->b_data, fs->fs_cgsize);
908 if (fs->fs_cgsize < fs->fs_bsize)
909 bzero(&nbp->b_data[fs->fs_cgsize],
910 fs->fs_bsize - fs->fs_cgsize);
911 cgp = (struct cg *)nbp->b_data;
914 nbp->b_flags |= B_VALIDSUSPWRT;
915 numblks = howmany(fs->fs_size, fs->fs_frag);
916 len = howmany(fs->fs_fpg, fs->fs_frag);
917 base = cgbase(fs, cg) / fs->fs_frag;
918 if (base + len >= numblks)
919 len = numblks - base - 1;
921 if (base < UFS_NDADDR) {
922 for ( ; loc < UFS_NDADDR; loc++) {
923 if (ffs_isblock(fs, cg_blksfree(cgp), loc))
924 DIP_SET(ip, i_db[loc], BLK_NOCOPY);
925 else if (passno == 2 && DIP(ip, i_db[loc])== BLK_NOCOPY)
926 DIP_SET(ip, i_db[loc], 0);
927 else if (passno == 1 && DIP(ip, i_db[loc])== BLK_NOCOPY)
928 panic("ffs_snapshot: lost direct block");
931 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(base + loc)),
932 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp);
936 indiroff = (base + loc - UFS_NDADDR) % NINDIR(fs);
937 for ( ; loc < len; loc++, indiroff++) {
938 if (indiroff >= NINDIR(fs)) {
940 ibp->b_flags |= B_VALIDSUSPWRT;
942 error = UFS_BALLOC(vp,
943 lblktosize(fs, (off_t)(base + loc)),
944 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp);
951 if (ffs_isblock(fs, cg_blksfree(cgp), loc))
952 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] =
954 else if (passno == 2 && ((ufs1_daddr_t *)(ibp->b_data))
955 [indiroff] == BLK_NOCOPY)
956 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] = 0;
957 else if (passno == 1 && ((ufs1_daddr_t *)(ibp->b_data))
958 [indiroff] == BLK_NOCOPY)
959 panic("ffs_snapshot: lost indirect block");
962 if (ffs_isblock(fs, cg_blksfree(cgp), loc))
963 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = BLK_NOCOPY;
964 else if (passno == 2 &&
965 ((ufs2_daddr_t *)(ibp->b_data)) [indiroff] == BLK_NOCOPY)
966 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = 0;
967 else if (passno == 1 &&
968 ((ufs2_daddr_t *)(ibp->b_data)) [indiroff] == BLK_NOCOPY)
969 panic("ffs_snapshot: lost indirect block");
972 ibp->b_flags |= B_VALIDSUSPWRT;
976 * We have to calculate the crc32c here rather than just setting the
977 * BX_CYLGRP b_xflags because the allocation of the block for the
978 * the cylinder group map will always be a full size block (fs_bsize)
979 * even though the cylinder group may be smaller (fs_cgsize). The
980 * crc32c must be computed only over fs_cgsize whereas the BX_CYLGRP
981 * flag causes it to be computed over the size of the buffer.
983 if ((fs->fs_metackhash & CK_CYLGRP) != 0) {
984 ((struct cg *)nbp->b_data)->cg_ckhash = 0;
985 ((struct cg *)nbp->b_data)->cg_ckhash =
986 calculate_crc32c(~0L, nbp->b_data, fs->fs_cgsize);
992 * Before expunging a snapshot inode, note all the
993 * blocks that it claims with BLK_SNAP so that fsck will
994 * be able to account for those blocks properly and so
995 * that this snapshot knows that it need not copy them
996 * if the other snapshot holding them is freed. This code
997 * is reproduced once each for UFS1 and UFS2.
1000 expunge_ufs1(snapvp, cancelip, fs, acctfunc, expungetype, clearmode)
1001 struct vnode *snapvp;
1002 struct inode *cancelip;
1004 int (*acctfunc)(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *,
1005 struct fs *, ufs_lbn_t, int);
1009 int i, error, indiroff;
1010 ufs_lbn_t lbn, rlbn;
1011 ufs2_daddr_t len, blkno, numblks, blksperindir;
1012 struct ufs1_dinode *dip;
1013 struct thread *td = curthread;
1017 * Prepare to expunge the inode. If its inode block has not
1018 * yet been copied, then allocate and fill the copy.
1020 lbn = fragstoblks(fs, ino_to_fsba(fs, cancelip->i_number));
1022 if (lbn < UFS_NDADDR) {
1023 blkno = VTOI(snapvp)->i_din1->di_db[lbn];
1025 if (DOINGSOFTDEP(snapvp))
1026 softdep_prealloc(snapvp, MNT_WAIT);
1027 td->td_pflags |= TDP_COWINPROGRESS;
1028 error = ffs_balloc_ufs1(snapvp, lblktosize(fs, (off_t)lbn),
1029 fs->fs_bsize, KERNCRED, BA_METAONLY, &bp);
1030 td->td_pflags &= ~TDP_COWINPROGRESS;
1033 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs);
1034 blkno = ((ufs1_daddr_t *)(bp->b_data))[indiroff];
1038 if ((error = bread(snapvp, lbn, fs->fs_bsize, KERNCRED, &bp)))
1041 error = ffs_balloc_ufs1(snapvp, lblktosize(fs, (off_t)lbn),
1042 fs->fs_bsize, KERNCRED, 0, &bp);
1045 if ((error = readblock(snapvp, bp, lbn)) != 0)
1049 * Set a snapshot inode to be a zero length file, regular files
1050 * or unlinked snapshots to be completely unallocated.
1052 dip = (struct ufs1_dinode *)bp->b_data +
1053 ino_to_fsbo(fs, cancelip->i_number);
1054 if (clearmode || cancelip->i_effnlink == 0)
1058 dip->di_flags &= ~SF_SNAPSHOT;
1059 bzero(&dip->di_db[0], (UFS_NDADDR + UFS_NIADDR) * sizeof(ufs1_daddr_t));
1062 * Now go through and expunge all the blocks in the file
1063 * using the function requested.
1065 numblks = howmany(cancelip->i_size, fs->fs_bsize);
1066 if ((error = (*acctfunc)(snapvp, &cancelip->i_din1->di_db[0],
1067 &cancelip->i_din1->di_db[UFS_NDADDR], fs, 0, expungetype)))
1069 if ((error = (*acctfunc)(snapvp, &cancelip->i_din1->di_ib[0],
1070 &cancelip->i_din1->di_ib[UFS_NIADDR], fs, -1, expungetype)))
1074 len = numblks - UFS_NDADDR;
1076 for (i = 0; len > 0 && i < UFS_NIADDR; i++) {
1077 error = indiracct_ufs1(snapvp, ITOV(cancelip), i,
1078 cancelip->i_din1->di_ib[i], lbn, rlbn, len,
1079 blksperindir, fs, acctfunc, expungetype);
1082 blksperindir *= NINDIR(fs);
1083 lbn -= blksperindir + 1;
1084 len -= blksperindir;
1085 rlbn += blksperindir;
1091 * Descend an indirect block chain for vnode cancelvp accounting for all
1092 * its indirect blocks in snapvp.
1095 indiracct_ufs1(snapvp, cancelvp, level, blkno, lbn, rlbn, remblks,
1096 blksperindir, fs, acctfunc, expungetype)
1097 struct vnode *snapvp;
1098 struct vnode *cancelvp;
1104 ufs_lbn_t blksperindir;
1106 int (*acctfunc)(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *,
1107 struct fs *, ufs_lbn_t, int);
1111 ufs_lbn_t subblksperindir;
1112 struct indir indirs[UFS_NIADDR + 2];
1113 ufs1_daddr_t last, *bap;
1117 if (expungetype == BLK_NOCOPY)
1119 panic("indiracct_ufs1: missing indir");
1121 if ((error = ufs_getlbns(cancelvp, rlbn, indirs, &num)) != 0)
1123 if (lbn != indirs[num - 1 - level].in_lbn || num < 2)
1124 panic("indiracct_ufs1: botched params");
1126 * We have to expand bread here since it will deadlock looking
1127 * up the block number for any blocks that are not in the cache.
1129 bp = getblk(cancelvp, lbn, fs->fs_bsize, 0, 0, 0);
1130 bp->b_blkno = fsbtodb(fs, blkno);
1131 if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0 &&
1132 (error = readblock(cancelvp, bp, fragstoblks(fs, blkno)))) {
1137 * Account for the block pointers in this indirect block.
1139 last = howmany(remblks, blksperindir);
1140 if (last > NINDIR(fs))
1142 bap = malloc(fs->fs_bsize, M_DEVBUF, M_WAITOK);
1143 bcopy(bp->b_data, (caddr_t)bap, fs->fs_bsize);
1145 error = (*acctfunc)(snapvp, &bap[0], &bap[last], fs,
1146 level == 0 ? rlbn : -1, expungetype);
1147 if (error || level == 0)
1150 * Account for the block pointers in each of the indirect blocks
1151 * in the levels below us.
1153 subblksperindir = blksperindir / NINDIR(fs);
1154 for (lbn++, level--, i = 0; i < last; i++) {
1155 error = indiracct_ufs1(snapvp, cancelvp, level, bap[i], lbn,
1156 rlbn, remblks, subblksperindir, fs, acctfunc, expungetype);
1159 rlbn += blksperindir;
1160 lbn -= blksperindir;
1161 remblks -= blksperindir;
1164 free(bap, M_DEVBUF);
1169 * Do both snap accounting and map accounting.
1172 fullacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, exptype)
1174 ufs1_daddr_t *oldblkp, *lastblkp;
1177 int exptype; /* BLK_SNAP or BLK_NOCOPY */
1181 if ((error = snapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, exptype)))
1183 return (mapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, exptype));
1187 * Identify a set of blocks allocated in a snapshot inode.
1190 snapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, expungetype)
1192 ufs1_daddr_t *oldblkp, *lastblkp;
1195 int expungetype; /* BLK_SNAP or BLK_NOCOPY */
1197 struct inode *ip = VTOI(vp);
1198 ufs1_daddr_t blkno, *blkp;
1203 for ( ; oldblkp < lastblkp; oldblkp++) {
1205 if (blkno == 0 || blkno == BLK_NOCOPY || blkno == BLK_SNAP)
1207 lbn = fragstoblks(fs, blkno);
1208 if (lbn < UFS_NDADDR) {
1209 blkp = &ip->i_din1->di_db[lbn];
1210 ip->i_flag |= IN_CHANGE | IN_UPDATE;
1212 error = ffs_balloc_ufs1(vp, lblktosize(fs, (off_t)lbn),
1213 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp);
1216 blkp = &((ufs1_daddr_t *)(ibp->b_data))
1217 [(lbn - UFS_NDADDR) % NINDIR(fs)];
1220 * If we are expunging a snapshot vnode and we
1221 * find a block marked BLK_NOCOPY, then it is
1222 * one that has been allocated to this snapshot after
1223 * we took our current snapshot and can be ignored.
1225 if (expungetype == BLK_SNAP && *blkp == BLK_NOCOPY) {
1226 if (lbn >= UFS_NDADDR)
1230 panic("snapacct_ufs1: bad block");
1231 *blkp = expungetype;
1232 if (lbn >= UFS_NDADDR)
1240 * Account for a set of blocks allocated in a snapshot inode.
1243 mapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, expungetype)
1245 ufs1_daddr_t *oldblkp, *lastblkp;
1256 inum = ip->i_number;
1261 for ( ; oldblkp < lastblkp; oldblkp++, lblkno++) {
1263 if (blkno == 0 || blkno == BLK_NOCOPY)
1265 if (acctit && expungetype == BLK_SNAP && blkno != BLK_SNAP)
1266 *ip->i_snapblklist++ = lblkno;
1267 if (blkno == BLK_SNAP)
1268 blkno = blkstofrags(fs, lblkno);
1269 ffs_blkfree(ITOUMP(ip), fs, vp, blkno, fs->fs_bsize, inum,
1270 vp->v_type, NULL, SINGLETON_KEY);
1276 * Before expunging a snapshot inode, note all the
1277 * blocks that it claims with BLK_SNAP so that fsck will
1278 * be able to account for those blocks properly and so
1279 * that this snapshot knows that it need not copy them
1280 * if the other snapshot holding them is freed. This code
1281 * is reproduced once each for UFS1 and UFS2.
1284 expunge_ufs2(snapvp, cancelip, fs, acctfunc, expungetype, clearmode)
1285 struct vnode *snapvp;
1286 struct inode *cancelip;
1288 int (*acctfunc)(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *,
1289 struct fs *, ufs_lbn_t, int);
1293 int i, error, indiroff;
1294 ufs_lbn_t lbn, rlbn;
1295 ufs2_daddr_t len, blkno, numblks, blksperindir;
1296 struct ufs2_dinode *dip;
1297 struct thread *td = curthread;
1301 * Prepare to expunge the inode. If its inode block has not
1302 * yet been copied, then allocate and fill the copy.
1304 lbn = fragstoblks(fs, ino_to_fsba(fs, cancelip->i_number));
1306 if (lbn < UFS_NDADDR) {
1307 blkno = VTOI(snapvp)->i_din2->di_db[lbn];
1309 if (DOINGSOFTDEP(snapvp))
1310 softdep_prealloc(snapvp, MNT_WAIT);
1311 td->td_pflags |= TDP_COWINPROGRESS;
1312 error = ffs_balloc_ufs2(snapvp, lblktosize(fs, (off_t)lbn),
1313 fs->fs_bsize, KERNCRED, BA_METAONLY, &bp);
1314 td->td_pflags &= ~TDP_COWINPROGRESS;
1317 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs);
1318 blkno = ((ufs2_daddr_t *)(bp->b_data))[indiroff];
1322 if ((error = bread(snapvp, lbn, fs->fs_bsize, KERNCRED, &bp)))
1325 error = ffs_balloc_ufs2(snapvp, lblktosize(fs, (off_t)lbn),
1326 fs->fs_bsize, KERNCRED, 0, &bp);
1329 if ((error = readblock(snapvp, bp, lbn)) != 0)
1333 * Set a snapshot inode to be a zero length file, regular files
1334 * to be completely unallocated.
1336 dip = (struct ufs2_dinode *)bp->b_data +
1337 ino_to_fsbo(fs, cancelip->i_number);
1340 dip->di_flags &= ~SF_SNAPSHOT;
1341 bzero(&dip->di_db[0], (UFS_NDADDR + UFS_NIADDR) * sizeof(ufs2_daddr_t));
1342 if (clearmode || cancelip->i_effnlink == 0)
1345 ffs_update_dinode_ckhash(fs, dip);
1348 * Now go through and expunge all the blocks in the file
1349 * using the function requested.
1351 numblks = howmany(cancelip->i_size, fs->fs_bsize);
1352 if ((error = (*acctfunc)(snapvp, &cancelip->i_din2->di_db[0],
1353 &cancelip->i_din2->di_db[UFS_NDADDR], fs, 0, expungetype)))
1355 if ((error = (*acctfunc)(snapvp, &cancelip->i_din2->di_ib[0],
1356 &cancelip->i_din2->di_ib[UFS_NIADDR], fs, -1, expungetype)))
1360 len = numblks - UFS_NDADDR;
1362 for (i = 0; len > 0 && i < UFS_NIADDR; i++) {
1363 error = indiracct_ufs2(snapvp, ITOV(cancelip), i,
1364 cancelip->i_din2->di_ib[i], lbn, rlbn, len,
1365 blksperindir, fs, acctfunc, expungetype);
1368 blksperindir *= NINDIR(fs);
1369 lbn -= blksperindir + 1;
1370 len -= blksperindir;
1371 rlbn += blksperindir;
1377 * Descend an indirect block chain for vnode cancelvp accounting for all
1378 * its indirect blocks in snapvp.
1381 indiracct_ufs2(snapvp, cancelvp, level, blkno, lbn, rlbn, remblks,
1382 blksperindir, fs, acctfunc, expungetype)
1383 struct vnode *snapvp;
1384 struct vnode *cancelvp;
1390 ufs_lbn_t blksperindir;
1392 int (*acctfunc)(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *,
1393 struct fs *, ufs_lbn_t, int);
1397 ufs_lbn_t subblksperindir;
1398 struct indir indirs[UFS_NIADDR + 2];
1399 ufs2_daddr_t last, *bap;
1403 if (expungetype == BLK_NOCOPY)
1405 panic("indiracct_ufs2: missing indir");
1407 if ((error = ufs_getlbns(cancelvp, rlbn, indirs, &num)) != 0)
1409 if (lbn != indirs[num - 1 - level].in_lbn || num < 2)
1410 panic("indiracct_ufs2: botched params");
1412 * We have to expand bread here since it will deadlock looking
1413 * up the block number for any blocks that are not in the cache.
1415 bp = getblk(cancelvp, lbn, fs->fs_bsize, 0, 0, 0);
1416 bp->b_blkno = fsbtodb(fs, blkno);
1417 if ((bp->b_flags & B_CACHE) == 0 &&
1418 (error = readblock(cancelvp, bp, fragstoblks(fs, blkno)))) {
1423 * Account for the block pointers in this indirect block.
1425 last = howmany(remblks, blksperindir);
1426 if (last > NINDIR(fs))
1428 bap = malloc(fs->fs_bsize, M_DEVBUF, M_WAITOK);
1429 bcopy(bp->b_data, (caddr_t)bap, fs->fs_bsize);
1431 error = (*acctfunc)(snapvp, &bap[0], &bap[last], fs,
1432 level == 0 ? rlbn : -1, expungetype);
1433 if (error || level == 0)
1436 * Account for the block pointers in each of the indirect blocks
1437 * in the levels below us.
1439 subblksperindir = blksperindir / NINDIR(fs);
1440 for (lbn++, level--, i = 0; i < last; i++) {
1441 error = indiracct_ufs2(snapvp, cancelvp, level, bap[i], lbn,
1442 rlbn, remblks, subblksperindir, fs, acctfunc, expungetype);
1445 rlbn += blksperindir;
1446 lbn -= blksperindir;
1447 remblks -= blksperindir;
1450 free(bap, M_DEVBUF);
1455 * Do both snap accounting and map accounting.
1458 fullacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, exptype)
1460 ufs2_daddr_t *oldblkp, *lastblkp;
1463 int exptype; /* BLK_SNAP or BLK_NOCOPY */
1467 if ((error = snapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, exptype)))
1469 return (mapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, exptype));
1473 * Identify a set of blocks allocated in a snapshot inode.
1476 snapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, expungetype)
1478 ufs2_daddr_t *oldblkp, *lastblkp;
1481 int expungetype; /* BLK_SNAP or BLK_NOCOPY */
1483 struct inode *ip = VTOI(vp);
1484 ufs2_daddr_t blkno, *blkp;
1489 for ( ; oldblkp < lastblkp; oldblkp++) {
1491 if (blkno == 0 || blkno == BLK_NOCOPY || blkno == BLK_SNAP)
1493 lbn = fragstoblks(fs, blkno);
1494 if (lbn < UFS_NDADDR) {
1495 blkp = &ip->i_din2->di_db[lbn];
1496 ip->i_flag |= IN_CHANGE | IN_UPDATE;
1498 error = ffs_balloc_ufs2(vp, lblktosize(fs, (off_t)lbn),
1499 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp);
1502 blkp = &((ufs2_daddr_t *)(ibp->b_data))
1503 [(lbn - UFS_NDADDR) % NINDIR(fs)];
1506 * If we are expunging a snapshot vnode and we
1507 * find a block marked BLK_NOCOPY, then it is
1508 * one that has been allocated to this snapshot after
1509 * we took our current snapshot and can be ignored.
1511 if (expungetype == BLK_SNAP && *blkp == BLK_NOCOPY) {
1512 if (lbn >= UFS_NDADDR)
1516 panic("snapacct_ufs2: bad block");
1517 *blkp = expungetype;
1518 if (lbn >= UFS_NDADDR)
1526 * Account for a set of blocks allocated in a snapshot inode.
1529 mapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, expungetype)
1531 ufs2_daddr_t *oldblkp, *lastblkp;
1542 inum = ip->i_number;
1547 for ( ; oldblkp < lastblkp; oldblkp++, lblkno++) {
1549 if (blkno == 0 || blkno == BLK_NOCOPY)
1551 if (acctit && expungetype == BLK_SNAP && blkno != BLK_SNAP)
1552 *ip->i_snapblklist++ = lblkno;
1553 if (blkno == BLK_SNAP)
1554 blkno = blkstofrags(fs, lblkno);
1555 ffs_blkfree(ITOUMP(ip), fs, vp, blkno, fs->fs_bsize, inum,
1556 vp->v_type, NULL, SINGLETON_KEY);
1562 * Decrement extra reference on snapshot when last name is removed.
1563 * It will not be freed until the last open reference goes away.
1572 struct snapdata *sn;
1573 struct ufsmount *ump;
1576 * Find snapshot in incore list.
1579 sn = ITODEVVP(ip)->v_rdev->si_snapdata;
1581 TAILQ_FOREACH(xp, &sn->sn_head, i_nextsnap)
1587 printf("ffs_snapgone: lost snapshot vnode %ju\n",
1588 (uintmax_t)ip->i_number);
1590 * Delete snapshot inode from superblock. Keep list dense.
1595 for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++)
1596 if (fs->fs_snapinum[snaploc] == ip->i_number)
1598 if (snaploc < FSMAXSNAP) {
1599 for (snaploc++; snaploc < FSMAXSNAP; snaploc++) {
1600 if (fs->fs_snapinum[snaploc] == 0)
1602 fs->fs_snapinum[snaploc - 1] = fs->fs_snapinum[snaploc];
1604 fs->fs_snapinum[snaploc - 1] = 0;
1610 * Prepare a snapshot file for being removed.
1617 struct vnode *devvp;
1620 ufs2_daddr_t numblks, blkno, dblk;
1621 int error, i, last, loc;
1622 struct snapdata *sn;
1626 devvp = ITODEVVP(ip);
1628 * If active, delete from incore list (this snapshot may
1629 * already have been in the process of being deleted, so
1630 * would not have been active).
1632 * Clear copy-on-write flag if last snapshot.
1635 if (ip->i_nextsnap.tqe_prev != 0) {
1636 sn = devvp->v_rdev->si_snapdata;
1637 TAILQ_REMOVE(&sn->sn_head, ip, i_nextsnap);
1638 ip->i_nextsnap.tqe_prev = 0;
1640 lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL);
1641 for (i = 0; i < sn->sn_lock.lk_recurse; i++)
1642 lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL);
1643 KASSERT(vp->v_vnlock == &sn->sn_lock,
1644 ("ffs_snapremove: lost lock mutation"));
1645 vp->v_vnlock = &vp->v_lock;
1647 while (sn->sn_lock.lk_recurse > 0)
1648 lockmgr(&sn->sn_lock, LK_RELEASE, NULL);
1649 lockmgr(&sn->sn_lock, LK_RELEASE, NULL);
1650 try_free_snapdata(devvp);
1654 * Clear all BLK_NOCOPY fields. Pass any block claims to other
1655 * snapshots that want them (see ffs_snapblkfree below).
1657 for (blkno = 1; blkno < UFS_NDADDR; blkno++) {
1658 dblk = DIP(ip, i_db[blkno]);
1661 if (dblk == BLK_NOCOPY || dblk == BLK_SNAP)
1662 DIP_SET(ip, i_db[blkno], 0);
1663 else if ((dblk == blkstofrags(fs, blkno) &&
1664 ffs_snapblkfree(fs, ITODEVVP(ip), dblk, fs->fs_bsize,
1665 ip->i_number, vp->v_type, NULL))) {
1666 DIP_SET(ip, i_blocks, DIP(ip, i_blocks) -
1667 btodb(fs->fs_bsize));
1668 DIP_SET(ip, i_db[blkno], 0);
1671 numblks = howmany(ip->i_size, fs->fs_bsize);
1672 for (blkno = UFS_NDADDR; blkno < numblks; blkno += NINDIR(fs)) {
1673 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)blkno),
1674 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp);
1677 if (fs->fs_size - blkno > NINDIR(fs))
1680 last = fs->fs_size - blkno;
1681 for (loc = 0; loc < last; loc++) {
1682 if (I_IS_UFS1(ip)) {
1683 dblk = ((ufs1_daddr_t *)(ibp->b_data))[loc];
1686 if (dblk == BLK_NOCOPY || dblk == BLK_SNAP)
1687 ((ufs1_daddr_t *)(ibp->b_data))[loc]= 0;
1688 else if ((dblk == blkstofrags(fs, blkno) &&
1689 ffs_snapblkfree(fs, ITODEVVP(ip), dblk,
1690 fs->fs_bsize, ip->i_number, vp->v_type,
1692 ip->i_din1->di_blocks -=
1693 btodb(fs->fs_bsize);
1694 ((ufs1_daddr_t *)(ibp->b_data))[loc]= 0;
1698 dblk = ((ufs2_daddr_t *)(ibp->b_data))[loc];
1701 if (dblk == BLK_NOCOPY || dblk == BLK_SNAP)
1702 ((ufs2_daddr_t *)(ibp->b_data))[loc] = 0;
1703 else if ((dblk == blkstofrags(fs, blkno) &&
1704 ffs_snapblkfree(fs, ITODEVVP(ip), dblk,
1705 fs->fs_bsize, ip->i_number, vp->v_type, NULL))) {
1706 ip->i_din2->di_blocks -= btodb(fs->fs_bsize);
1707 ((ufs2_daddr_t *)(ibp->b_data))[loc] = 0;
1713 * Clear snapshot flag and drop reference.
1715 ip->i_flags &= ~SF_SNAPSHOT;
1716 DIP_SET(ip, i_flags, ip->i_flags);
1717 ip->i_flag |= IN_CHANGE | IN_UPDATE;
1719 * The dirtied indirects must be written out before
1720 * softdep_setup_freeblocks() is called. Otherwise indir_trunc()
1721 * may find indirect pointers using the magic BLK_* values.
1723 if (DOINGSOFTDEP(vp))
1724 ffs_syncvnode(vp, MNT_WAIT, 0);
1727 * Reenable disk quotas for ex-snapshot file.
1729 if (!getinoquota(ip))
1730 (void) chkdq(ip, DIP(ip, i_blocks), KERNCRED, FORCE);
1735 * Notification that a block is being freed. Return zero if the free
1736 * should be allowed to proceed. Return non-zero if the snapshot file
1737 * wants to claim the block. The block will be claimed if it is an
1738 * uncopied part of one of the snapshots. It will be freed if it is
1739 * either a BLK_NOCOPY or has already been copied in all of the snapshots.
1740 * If a fragment is being freed, then all snapshots that care about
1741 * it must make a copy since a snapshot file can only claim full sized
1742 * blocks. Note that if more than one snapshot file maps the block,
1743 * we can pick one at random to claim it. Since none of the snapshots
1744 * can change, we are assurred that they will all see the same unmodified
1745 * image. When deleting a snapshot file (see ffs_snapremove above), we
1746 * must push any of these claimed blocks to one of the other snapshots
1747 * that maps it. These claimed blocks are easily identified as they will
1748 * have a block number equal to their logical block number within the
1749 * snapshot. A copied block can never have this property because they
1750 * must always have been allocated from a BLK_NOCOPY location.
1753 ffs_snapblkfree(fs, devvp, bno, size, inum, vtype, wkhd)
1755 struct vnode *devvp;
1760 struct workhead *wkhd;
1762 struct buf *ibp, *cbp, *savedcbp = NULL;
1763 struct thread *td = curthread;
1765 struct vnode *vp = NULL;
1768 int indiroff = 0, error = 0, claimedblk = 0;
1769 struct snapdata *sn;
1771 lbn = fragstoblks(fs, bno);
1774 sn = devvp->v_rdev->si_snapdata;
1779 if (lockmgr(&sn->sn_lock, LK_INTERLOCK | LK_EXCLUSIVE | LK_SLEEPFAIL,
1780 VI_MTX(devvp)) != 0)
1782 TAILQ_FOREACH(ip, &sn->sn_head, i_nextsnap) {
1784 if (DOINGSOFTDEP(vp))
1785 softdep_prealloc(vp, MNT_WAIT);
1787 * Lookup block being written.
1789 if (lbn < UFS_NDADDR) {
1790 blkno = DIP(ip, i_db[lbn]);
1792 td->td_pflags |= TDP_COWINPROGRESS;
1793 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn),
1794 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp);
1795 td->td_pflags &= ~TDP_COWINPROGRESS;
1798 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs);
1800 blkno=((ufs1_daddr_t *)(ibp->b_data))[indiroff];
1802 blkno=((ufs2_daddr_t *)(ibp->b_data))[indiroff];
1805 * Check to see if block needs to be copied.
1809 * A block that we map is being freed. If it has not
1810 * been claimed yet, we will claim or copy it (below).
1813 } else if (blkno == BLK_SNAP) {
1815 * No previous snapshot claimed the block,
1816 * so it will be freed and become a BLK_NOCOPY
1817 * (don't care) for us.
1820 panic("snapblkfree: inconsistent block type");
1821 if (lbn < UFS_NDADDR) {
1822 DIP_SET(ip, i_db[lbn], BLK_NOCOPY);
1823 ip->i_flag |= IN_CHANGE | IN_UPDATE;
1824 } else if (I_IS_UFS1(ip)) {
1825 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] =
1829 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] =
1834 } else /* BLK_NOCOPY or default */ {
1836 * If the snapshot has already copied the block
1837 * (default), or does not care about the block,
1840 if (lbn >= UFS_NDADDR)
1845 * If this is a full size block, we will just grab it
1846 * and assign it to the snapshot inode. Otherwise we
1847 * will proceed to copy it. See explanation for this
1848 * routine as to why only a single snapshot needs to
1851 if (size == fs->fs_bsize) {
1854 printf("%s %ju lbn %jd from inum %ju\n",
1855 "Grabonremove: snapino",
1856 (uintmax_t)ip->i_number,
1857 (intmax_t)lbn, (uintmax_t)inum);
1860 * If journaling is tracking this write we must add
1861 * the work to the inode or indirect being written.
1864 if (lbn < UFS_NDADDR)
1865 softdep_inode_append(ip,
1866 curthread->td_ucred, wkhd);
1868 softdep_buf_append(ibp, wkhd);
1870 if (lbn < UFS_NDADDR) {
1871 DIP_SET(ip, i_db[lbn], bno);
1872 } else if (I_IS_UFS1(ip)) {
1873 ((ufs1_daddr_t *)(ibp->b_data))[indiroff] = bno;
1876 ((ufs2_daddr_t *)(ibp->b_data))[indiroff] = bno;
1879 DIP_SET(ip, i_blocks, DIP(ip, i_blocks) + btodb(size));
1880 ip->i_flag |= IN_CHANGE | IN_UPDATE;
1881 lockmgr(vp->v_vnlock, LK_RELEASE, NULL);
1884 if (lbn >= UFS_NDADDR)
1887 * Allocate the block into which to do the copy. Note that this
1888 * allocation will never require any additional allocations for
1889 * the snapshot inode.
1891 td->td_pflags |= TDP_COWINPROGRESS;
1892 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn),
1893 fs->fs_bsize, KERNCRED, 0, &cbp);
1894 td->td_pflags &= ~TDP_COWINPROGRESS;
1899 printf("%s%ju lbn %jd %s %ju size %ld to blkno %jd\n",
1900 "Copyonremove: snapino ", (uintmax_t)ip->i_number,
1901 (intmax_t)lbn, "for inum", (uintmax_t)inum, size,
1902 (intmax_t)cbp->b_blkno);
1905 * If we have already read the old block contents, then
1906 * simply copy them to the new block. Note that we need
1907 * to synchronously write snapshots that have not been
1908 * unlinked, and hence will be visible after a crash,
1909 * to ensure their integrity. At a minimum we ensure the
1910 * integrity of the filesystem metadata, but use the
1911 * dopersistence sysctl-setable flag to decide on the
1912 * persistence needed for file content data.
1914 if (savedcbp != NULL) {
1915 bcopy(savedcbp->b_data, cbp->b_data, fs->fs_bsize);
1917 if ((vtype == VDIR || dopersistence) &&
1919 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT);
1923 * Otherwise, read the old block contents into the buffer.
1925 if ((error = readblock(vp, cbp, lbn)) != 0) {
1926 bzero(cbp->b_data, fs->fs_bsize);
1928 if ((vtype == VDIR || dopersistence) &&
1930 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT);
1936 * Note that we need to synchronously write snapshots that
1937 * have not been unlinked, and hence will be visible after
1938 * a crash, to ensure their integrity. At a minimum we
1939 * ensure the integrity of the filesystem metadata, but
1940 * use the dopersistence sysctl-setable flag to decide on
1941 * the persistence needed for file content data.
1944 vp = savedcbp->b_vp;
1946 if ((vtype == VDIR || dopersistence) &&
1947 VTOI(vp)->i_effnlink > 0)
1948 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT);
1951 * If we have been unable to allocate a block in which to do
1952 * the copy, then return non-zero so that the fragment will
1953 * not be freed. Although space will be lost, the snapshot
1954 * will stay consistent.
1956 if (error != 0 && wkhd != NULL)
1957 softdep_freework(wkhd);
1958 lockmgr(&sn->sn_lock, LK_RELEASE, NULL);
1963 * Associate snapshot files when mounting.
1966 ffs_snapshot_mount(mp)
1969 struct ufsmount *ump = VFSTOUFS(mp);
1970 struct vnode *devvp = ump->um_devvp;
1971 struct fs *fs = ump->um_fs;
1972 struct thread *td = curthread;
1973 struct snapdata *sn;
1975 struct vnode *lastvp;
1981 daddr_t snaplistsize;
1982 int error, snaploc, loc;
1985 * XXX The following needs to be set before ffs_truncate or
1986 * VOP_READ can be called.
1988 mp->mnt_stat.f_iosize = fs->fs_bsize;
1990 * Process each snapshot listed in the superblock.
1995 for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++) {
1996 if (fs->fs_snapinum[snaploc] == 0)
1998 if ((error = ffs_vget(mp, fs->fs_snapinum[snaploc],
1999 LK_EXCLUSIVE, &vp)) != 0){
2000 printf("ffs_snapshot_mount: vget failed %d\n", error);
2004 if (vp->v_type != VREG) {
2005 reason = "non-file snapshot";
2006 } else if (!IS_SNAPSHOT(ip)) {
2007 reason = "non-snapshot";
2008 } else if (ip->i_size ==
2009 lblktosize(fs, howmany(fs->fs_size, fs->fs_frag))) {
2010 reason = "old format snapshot";
2011 (void)ffs_truncate(vp, (off_t)0, 0, NOCRED);
2012 (void)ffs_syncvnode(vp, MNT_WAIT, 0);
2016 if (reason != NULL) {
2017 printf("ffs_snapshot_mount: %s inode %d\n",
2018 reason, fs->fs_snapinum[snaploc]);
2021 for (loc = snaploc + 1; loc < FSMAXSNAP; loc++) {
2022 if (fs->fs_snapinum[loc] == 0)
2024 fs->fs_snapinum[loc - 1] = fs->fs_snapinum[loc];
2026 fs->fs_snapinum[loc - 1] = 0;
2031 * Acquire a lock on the snapdata structure, creating it if
2034 sn = ffs_snapdata_acquire(devvp);
2036 * Change vnode to use shared snapshot lock instead of the
2037 * original private lock.
2039 vp->v_vnlock = &sn->sn_lock;
2040 lockmgr(&vp->v_lock, LK_RELEASE, NULL);
2042 * Link it onto the active snapshot list.
2045 if (ip->i_nextsnap.tqe_prev != 0)
2046 panic("ffs_snapshot_mount: %ju already on list",
2047 (uintmax_t)ip->i_number);
2049 TAILQ_INSERT_TAIL(&sn->sn_head, ip, i_nextsnap);
2050 vp->v_vflag |= VV_SYSTEM;
2057 * No usable snapshots found.
2059 if (sn == NULL || vp == NULL)
2062 * Allocate the space for the block hints list. We always want to
2063 * use the list from the newest snapshot.
2065 auio.uio_iov = &aiov;
2066 auio.uio_iovcnt = 1;
2067 aiov.iov_base = (void *)&snaplistsize;
2068 aiov.iov_len = sizeof(snaplistsize);
2069 auio.uio_resid = aiov.iov_len;
2071 lblktosize(fs, howmany(fs->fs_size, fs->fs_frag));
2072 auio.uio_segflg = UIO_SYSSPACE;
2073 auio.uio_rw = UIO_READ;
2075 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2076 if ((error = VOP_READ(vp, &auio, IO_UNIT, td->td_ucred)) != 0) {
2077 printf("ffs_snapshot_mount: read_1 failed %d\n", error);
2081 snapblklist = malloc(snaplistsize * sizeof(daddr_t),
2082 M_UFSMNT, M_WAITOK);
2083 auio.uio_iovcnt = 1;
2084 aiov.iov_base = snapblklist;
2085 aiov.iov_len = snaplistsize * sizeof (daddr_t);
2086 auio.uio_resid = aiov.iov_len;
2087 auio.uio_offset -= sizeof(snaplistsize);
2088 if ((error = VOP_READ(vp, &auio, IO_UNIT, td->td_ucred)) != 0) {
2089 printf("ffs_snapshot_mount: read_2 failed %d\n", error);
2091 free(snapblklist, M_UFSMNT);
2096 ASSERT_VOP_LOCKED(devvp, "ffs_snapshot_mount");
2097 sn->sn_listsize = snaplistsize;
2098 sn->sn_blklist = (daddr_t *)snapblklist;
2099 devvp->v_vflag |= VV_COPYONWRITE;
2104 * Disassociate snapshot files when unmounting.
2107 ffs_snapshot_unmount(mp)
2110 struct vnode *devvp = VFSTOUFS(mp)->um_devvp;
2111 struct snapdata *sn;
2116 sn = devvp->v_rdev->si_snapdata;
2117 while (sn != NULL && (xp = TAILQ_FIRST(&sn->sn_head)) != NULL) {
2119 TAILQ_REMOVE(&sn->sn_head, xp, i_nextsnap);
2120 xp->i_nextsnap.tqe_prev = 0;
2121 lockmgr(&sn->sn_lock, LK_INTERLOCK | LK_EXCLUSIVE,
2123 lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL);
2124 KASSERT(vp->v_vnlock == &sn->sn_lock,
2125 ("ffs_snapshot_unmount: lost lock mutation"));
2126 vp->v_vnlock = &vp->v_lock;
2127 lockmgr(&vp->v_lock, LK_RELEASE, NULL);
2128 lockmgr(&sn->sn_lock, LK_RELEASE, NULL);
2129 if (xp->i_effnlink > 0)
2132 sn = devvp->v_rdev->si_snapdata;
2134 try_free_snapdata(devvp);
2135 ASSERT_VOP_LOCKED(devvp, "ffs_snapshot_unmount");
2139 * Check the buffer block to be belong to device buffer that shall be
2140 * locked after snaplk. devvp shall be locked on entry, and will be
2141 * leaved locked upon exit.
2144 ffs_bp_snapblk(devvp, bp)
2145 struct vnode *devvp;
2148 struct snapdata *sn;
2150 ufs2_daddr_t lbn, *snapblklist;
2151 int lower, upper, mid;
2153 ASSERT_VI_LOCKED(devvp, "ffs_bp_snapblk");
2154 KASSERT(devvp->v_type == VCHR, ("Not a device %p", devvp));
2155 sn = devvp->v_rdev->si_snapdata;
2156 if (sn == NULL || TAILQ_FIRST(&sn->sn_head) == NULL)
2158 fs = ITOFS(TAILQ_FIRST(&sn->sn_head));
2159 lbn = fragstoblks(fs, dbtofsb(fs, bp->b_blkno));
2160 snapblklist = sn->sn_blklist;
2161 upper = sn->sn_listsize - 1;
2163 while (lower <= upper) {
2164 mid = (lower + upper) / 2;
2165 if (snapblklist[mid] == lbn)
2167 if (snapblklist[mid] < lbn)
2183 struct vnode *vp, *devvp;
2187 if (bo->bo_dirty.bv_cnt <= dirtybufthresh)
2192 devvp = bo2vnode(bo);
2193 KASSERT(vp == devvp, ("devvp != vp %p %p", bo, bp));
2196 bp_bdskip = ffs_bp_snapblk(devvp, bp);
2200 if (bo->bo_dirty.bv_cnt > dirtybufthresh + 10 && !bp_bdskip) {
2201 (void) VOP_FSYNC(vp, MNT_NOWAIT, td);
2206 * Try to find a buffer to flush.
2208 TAILQ_FOREACH(nbp, &bo->bo_dirty.bv_hd, b_bobufs) {
2209 if ((nbp->b_vflags & BV_BKGRDINPROG) ||
2211 LK_EXCLUSIVE | LK_NOWAIT, NULL))
2214 panic("bdwrite: found ourselves");
2217 * Don't countdeps with the bo lock
2220 if (buf_countdeps(nbp, 0)) {
2227 if (!ffs_bp_snapblk(vp, nbp)) {
2235 if (nbp->b_flags & B_CLUSTEROK) {
2236 vfs_bio_awrite(nbp);
2241 dirtybufferflushes++;
2250 * Check for need to copy block that is about to be written,
2251 * copying the block if necessary.
2254 ffs_copyonwrite(devvp, bp)
2255 struct vnode *devvp;
2258 struct snapdata *sn;
2259 struct buf *ibp, *cbp, *savedcbp = NULL;
2260 struct thread *td = curthread;
2263 struct vnode *vp = NULL;
2264 ufs2_daddr_t lbn, blkno, *snapblklist;
2265 int lower, upper, mid, indiroff, error = 0;
2266 int launched_async_io, prev_norunningbuf;
2267 long saved_runningbufspace;
2269 if (devvp != bp->b_vp && IS_SNAPSHOT(VTOI(bp->b_vp)))
2270 return (0); /* Update on a snapshot file */
2271 if (td->td_pflags & TDP_COWINPROGRESS)
2272 panic("ffs_copyonwrite: recursive call");
2274 * First check to see if it is in the preallocated list.
2275 * By doing this check we avoid several potential deadlocks.
2278 sn = devvp->v_rdev->si_snapdata;
2280 TAILQ_EMPTY(&sn->sn_head)) {
2282 return (0); /* No snapshot */
2284 ip = TAILQ_FIRST(&sn->sn_head);
2286 lbn = fragstoblks(fs, dbtofsb(fs, bp->b_blkno));
2287 snapblklist = sn->sn_blklist;
2288 upper = sn->sn_listsize - 1;
2290 while (lower <= upper) {
2291 mid = (lower + upper) / 2;
2292 if (snapblklist[mid] == lbn)
2294 if (snapblklist[mid] < lbn)
2299 if (lower <= upper) {
2303 launched_async_io = 0;
2304 prev_norunningbuf = td->td_pflags & TDP_NORUNNINGBUF;
2306 * Since I/O on bp isn't yet in progress and it may be blocked
2307 * for a long time waiting on snaplk, back it out of
2308 * runningbufspace, possibly waking other threads waiting for space.
2310 saved_runningbufspace = bp->b_runningbufspace;
2311 if (saved_runningbufspace != 0)
2312 runningbufwakeup(bp);
2314 * Not in the precomputed list, so check the snapshots.
2316 while (lockmgr(&sn->sn_lock, LK_INTERLOCK | LK_EXCLUSIVE | LK_SLEEPFAIL,
2317 VI_MTX(devvp)) != 0) {
2319 sn = devvp->v_rdev->si_snapdata;
2321 TAILQ_EMPTY(&sn->sn_head)) {
2323 if (saved_runningbufspace != 0) {
2324 bp->b_runningbufspace = saved_runningbufspace;
2325 atomic_add_long(&runningbufspace,
2326 bp->b_runningbufspace);
2328 return (0); /* Snapshot gone */
2331 TAILQ_FOREACH(ip, &sn->sn_head, i_nextsnap) {
2333 if (DOINGSOFTDEP(vp))
2334 softdep_prealloc(vp, MNT_WAIT);
2336 * We ensure that everything of our own that needs to be
2337 * copied will be done at the time that ffs_snapshot is
2338 * called. Thus we can skip the check here which can
2339 * deadlock in doing the lookup in UFS_BALLOC.
2344 * Check to see if block needs to be copied. We do not have
2345 * to hold the snapshot lock while doing this lookup as it
2346 * will never require any additional allocations for the
2349 if (lbn < UFS_NDADDR) {
2350 blkno = DIP(ip, i_db[lbn]);
2352 td->td_pflags |= TDP_COWINPROGRESS | TDP_NORUNNINGBUF;
2353 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn),
2354 fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp);
2355 td->td_pflags &= ~TDP_COWINPROGRESS;
2358 indiroff = (lbn - UFS_NDADDR) % NINDIR(fs);
2360 blkno=((ufs1_daddr_t *)(ibp->b_data))[indiroff];
2362 blkno=((ufs2_daddr_t *)(ibp->b_data))[indiroff];
2366 if (blkno == BLK_SNAP && bp->b_lblkno >= 0)
2367 panic("ffs_copyonwrite: bad copy block");
2372 * Allocate the block into which to do the copy. Since
2373 * multiple processes may all try to copy the same block,
2374 * we have to recheck our need to do a copy if we sleep
2375 * waiting for the lock.
2377 * Because all snapshots on a filesystem share a single
2378 * lock, we ensure that we will never be in competition
2379 * with another process to allocate a block.
2381 td->td_pflags |= TDP_COWINPROGRESS | TDP_NORUNNINGBUF;
2382 error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn),
2383 fs->fs_bsize, KERNCRED, 0, &cbp);
2384 td->td_pflags &= ~TDP_COWINPROGRESS;
2389 printf("Copyonwrite: snapino %ju lbn %jd for ",
2390 (uintmax_t)ip->i_number, (intmax_t)lbn);
2391 if (bp->b_vp == devvp)
2392 printf("fs metadata");
2395 (uintmax_t)VTOI(bp->b_vp)->i_number);
2396 printf(" lblkno %jd to blkno %jd\n",
2397 (intmax_t)bp->b_lblkno, (intmax_t)cbp->b_blkno);
2401 * If we have already read the old block contents, then
2402 * simply copy them to the new block. Note that we need
2403 * to synchronously write snapshots that have not been
2404 * unlinked, and hence will be visible after a crash,
2405 * to ensure their integrity. At a minimum we ensure the
2406 * integrity of the filesystem metadata, but use the
2407 * dopersistence sysctl-setable flag to decide on the
2408 * persistence needed for file content data.
2410 if (savedcbp != NULL) {
2411 bcopy(savedcbp->b_data, cbp->b_data, fs->fs_bsize);
2413 if ((devvp == bp->b_vp || bp->b_vp->v_type == VDIR ||
2414 dopersistence) && ip->i_effnlink > 0)
2415 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT);
2417 launched_async_io = 1;
2421 * Otherwise, read the old block contents into the buffer.
2423 if ((error = readblock(vp, cbp, lbn)) != 0) {
2424 bzero(cbp->b_data, fs->fs_bsize);
2426 if ((devvp == bp->b_vp || bp->b_vp->v_type == VDIR ||
2427 dopersistence) && ip->i_effnlink > 0)
2428 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT);
2430 launched_async_io = 1;
2436 * Note that we need to synchronously write snapshots that
2437 * have not been unlinked, and hence will be visible after
2438 * a crash, to ensure their integrity. At a minimum we
2439 * ensure the integrity of the filesystem metadata, but
2440 * use the dopersistence sysctl-setable flag to decide on
2441 * the persistence needed for file content data.
2444 vp = savedcbp->b_vp;
2446 if ((devvp == bp->b_vp || bp->b_vp->v_type == VDIR ||
2447 dopersistence) && VTOI(vp)->i_effnlink > 0)
2448 (void) ffs_syncvnode(vp, MNT_WAIT, NO_INO_UPDT);
2450 launched_async_io = 1;
2452 lockmgr(vp->v_vnlock, LK_RELEASE, NULL);
2453 td->td_pflags = (td->td_pflags & ~TDP_NORUNNINGBUF) |
2455 if (launched_async_io && (td->td_pflags & TDP_NORUNNINGBUF) == 0)
2456 waitrunningbufspace();
2458 * I/O on bp will now be started, so count it in runningbufspace.
2460 if (saved_runningbufspace != 0) {
2461 bp->b_runningbufspace = saved_runningbufspace;
2462 atomic_add_long(&runningbufspace, bp->b_runningbufspace);
2468 * sync snapshots to force freework records waiting on snapshots to claim
2472 ffs_sync_snap(mp, waitfor)
2476 struct snapdata *sn;
2477 struct vnode *devvp;
2481 devvp = VFSTOUFS(mp)->um_devvp;
2482 if ((devvp->v_vflag & VV_COPYONWRITE) == 0)
2486 sn = devvp->v_rdev->si_snapdata;
2491 if (lockmgr(&sn->sn_lock,
2492 LK_INTERLOCK | LK_EXCLUSIVE | LK_SLEEPFAIL,
2493 VI_MTX(devvp)) == 0)
2496 TAILQ_FOREACH(ip, &sn->sn_head, i_nextsnap) {
2498 ffs_syncvnode(vp, waitfor, NO_INO_UPDT);
2500 lockmgr(&sn->sn_lock, LK_RELEASE, NULL);
2504 * Read the specified block into the given buffer.
2505 * Much of this boiler-plate comes from bwrite().
2508 readblock(vp, bp, lbn)
2520 bip = g_alloc_bio();
2521 bip->bio_cmd = BIO_READ;
2522 bip->bio_offset = dbtob(fsbtodb(fs, blkstofrags(fs, lbn)));
2523 bip->bio_data = bp->b_data;
2524 bip->bio_length = bp->b_bcount;
2525 bip->bio_done = NULL;
2527 g_io_request(bip, ITODEVVP(ip)->v_bufobj.bo_private);
2528 bp->b_error = biowait(bip, "snaprdb");
2530 return (bp->b_error);
2536 * Process file deletes that were deferred by ufs_inactive() due to
2537 * the file system being suspended. Transfer IN_LAZYACCESS into
2538 * IN_MODIFIED for vnodes that were accessed during suspension.
2541 process_deferred_inactive(struct mount *mp)
2543 struct vnode *vp, *mvp;
2549 (void) vn_start_secondary_write(NULL, &mp, V_WAIT);
2551 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
2553 * IN_LAZYACCESS is checked here without holding any
2554 * vnode lock, but this flag is set only while holding
2557 if (vp->v_type == VNON ||
2558 ((VTOI(vp)->i_flag & IN_LAZYACCESS) == 0 &&
2559 ((vp->v_iflag & VI_OWEINACT) == 0 || vp->v_usecount > 0))) {
2564 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK);
2567 if (error == ENOENT)
2568 continue; /* vnode recycled */
2569 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
2573 if ((ip->i_flag & IN_LAZYACCESS) != 0) {
2574 ip->i_flag &= ~IN_LAZYACCESS;
2575 ip->i_flag |= IN_MODIFIED;
2578 if ((vp->v_iflag & VI_OWEINACT) == 0 || vp->v_usecount > 0) {
2585 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp,
2586 ("process_deferred_inactive: got VI_OWEINACT"));
2591 vn_finished_secondary_write(mp);
2594 #ifndef NO_FFS_SNAPSHOT
2596 static struct snapdata *
2597 ffs_snapdata_alloc(void)
2599 struct snapdata *sn;
2602 * Fetch a snapdata from the free list if there is one available.
2604 mtx_lock(&snapfree_lock);
2605 sn = LIST_FIRST(&snapfree);
2607 LIST_REMOVE(sn, sn_link);
2608 mtx_unlock(&snapfree_lock);
2612 * If there were no free snapdatas allocate one.
2614 sn = malloc(sizeof *sn, M_UFSMNT, M_WAITOK | M_ZERO);
2615 TAILQ_INIT(&sn->sn_head);
2616 lockinit(&sn->sn_lock, PVFS, "snaplk", VLKTIMEOUT,
2617 LK_CANRECURSE | LK_NOSHARE);
2622 * The snapdata is never freed because we can not be certain that
2623 * there are no threads sleeping on the snap lock. Persisting
2624 * them permanently avoids costly synchronization in ffs_lock().
2627 ffs_snapdata_free(struct snapdata *sn)
2629 mtx_lock(&snapfree_lock);
2630 LIST_INSERT_HEAD(&snapfree, sn, sn_link);
2631 mtx_unlock(&snapfree_lock);
2634 /* Try to free snapdata associated with devvp */
2636 try_free_snapdata(struct vnode *devvp)
2638 struct snapdata *sn;
2639 ufs2_daddr_t *snapblklist;
2641 ASSERT_VI_LOCKED(devvp, "try_free_snapdata");
2642 sn = devvp->v_rdev->si_snapdata;
2644 if (sn == NULL || TAILQ_FIRST(&sn->sn_head) != NULL ||
2645 (devvp->v_vflag & VV_COPYONWRITE) == 0) {
2650 devvp->v_rdev->si_snapdata = NULL;
2651 devvp->v_vflag &= ~VV_COPYONWRITE;
2652 lockmgr(&sn->sn_lock, LK_DRAIN|LK_INTERLOCK, VI_MTX(devvp));
2653 snapblklist = sn->sn_blklist;
2654 sn->sn_blklist = NULL;
2655 sn->sn_listsize = 0;
2656 lockmgr(&sn->sn_lock, LK_RELEASE, NULL);
2657 if (snapblklist != NULL)
2658 free(snapblklist, M_UFSMNT);
2659 ffs_snapdata_free(sn);
2662 static struct snapdata *
2663 ffs_snapdata_acquire(struct vnode *devvp)
2665 struct snapdata *nsn, *sn;
2669 * Allocate a free snapdata. This is done before acquiring the
2670 * devvp lock to avoid allocation while the devvp interlock is
2673 nsn = ffs_snapdata_alloc();
2677 sn = devvp->v_rdev->si_snapdata;
2680 * This is the first snapshot on this
2681 * filesystem and we use our pre-allocated
2682 * snapdata. Publish sn with the sn_lock
2683 * owned by us, to avoid the race.
2685 error = lockmgr(&nsn->sn_lock, LK_EXCLUSIVE |
2688 panic("leaked sn, lockmgr error %d", error);
2689 sn = devvp->v_rdev->si_snapdata = nsn;
2696 * There is a snapshots which already exists on this
2697 * filesystem, grab a reference to the common lock.
2699 error = lockmgr(&sn->sn_lock, LK_INTERLOCK |
2700 LK_EXCLUSIVE | LK_SLEEPFAIL, VI_MTX(devvp));
2706 * Free any unused snapdata.
2709 ffs_snapdata_free(nsn);