1 | /* $NetBSD: ffs_snapshot.c,v 1.143 2016/10/28 20:38:12 jdolecek Exp $ */ |
2 | |
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 | * from FreeBSD: ffs_snapshot.c,v 1.79 2004/02/13 02:02:06 kuriyama Exp |
38 | */ |
39 | |
40 | #include <sys/cdefs.h> |
41 | __KERNEL_RCSID(0, "$NetBSD: ffs_snapshot.c,v 1.143 2016/10/28 20:38:12 jdolecek Exp $" ); |
42 | |
43 | #if defined(_KERNEL_OPT) |
44 | #include "opt_ffs.h" |
45 | #include "opt_quota.h" |
46 | #endif |
47 | |
48 | #include <sys/param.h> |
49 | #include <sys/kernel.h> |
50 | #include <sys/systm.h> |
51 | #include <sys/conf.h> |
52 | #include <sys/buf.h> |
53 | #include <sys/proc.h> |
54 | #include <sys/namei.h> |
55 | #include <sys/sched.h> |
56 | #include <sys/stat.h> |
57 | #include <sys/malloc.h> |
58 | #include <sys/mount.h> |
59 | #include <sys/resource.h> |
60 | #include <sys/resourcevar.h> |
61 | #include <sys/vnode.h> |
62 | #include <sys/kauth.h> |
63 | #include <sys/fstrans.h> |
64 | #include <sys/wapbl.h> |
65 | |
66 | #include <miscfs/specfs/specdev.h> |
67 | |
68 | #include <ufs/ufs/quota.h> |
69 | #include <ufs/ufs/ufsmount.h> |
70 | #include <ufs/ufs/inode.h> |
71 | #include <ufs/ufs/ufs_extern.h> |
72 | #include <ufs/ufs/ufs_bswap.h> |
73 | #include <ufs/ufs/ufs_wapbl.h> |
74 | |
75 | #include <ufs/ffs/fs.h> |
76 | #include <ufs/ffs/ffs_extern.h> |
77 | |
78 | #include <uvm/uvm.h> |
79 | |
80 | TAILQ_HEAD(inodelst, inode); /* List of active snapshots */ |
81 | |
82 | struct snap_info { |
83 | kmutex_t si_lock; /* Lock this snapinfo */ |
84 | kmutex_t si_snaplock; /* Snapshot vnode common lock */ |
85 | lwp_t *si_owner; /* Snaplock owner */ |
86 | struct inodelst si_snapshots; /* List of active snapshots */ |
87 | daddr_t *si_snapblklist; /* Snapshot block hints list */ |
88 | uint32_t si_gen; /* Incremented on change */ |
89 | }; |
90 | |
91 | #if !defined(FFS_NO_SNAPSHOT) |
92 | typedef int (*acctfunc_t) |
93 | (struct vnode *, void *, int, int, struct fs *, daddr_t, int); |
94 | |
95 | static int snapshot_setup(struct mount *, struct vnode *); |
96 | static int snapshot_copyfs(struct mount *, struct vnode *, void **); |
97 | static int snapshot_expunge(struct mount *, struct vnode *, |
98 | struct fs *, daddr_t *, daddr_t **); |
99 | static int snapshot_expunge_snap(struct mount *, struct vnode *, |
100 | struct fs *, daddr_t); |
101 | static int snapshot_writefs(struct mount *, struct vnode *, void *); |
102 | static int cgaccount(struct vnode *, int, int *); |
103 | static int cgaccount1(int, struct vnode *, void *, int); |
104 | static int expunge(struct vnode *, struct inode *, struct fs *, |
105 | acctfunc_t, int); |
106 | static int indiracct(struct vnode *, struct vnode *, int, daddr_t, |
107 | daddr_t, daddr_t, daddr_t, daddr_t, struct fs *, acctfunc_t, int); |
108 | static int fullacct(struct vnode *, void *, int, int, struct fs *, |
109 | daddr_t, int); |
110 | static int snapacct(struct vnode *, void *, int, int, struct fs *, |
111 | daddr_t, int); |
112 | static int mapacct(struct vnode *, void *, int, int, struct fs *, |
113 | daddr_t, int); |
114 | #endif /* !defined(FFS_NO_SNAPSHOT) */ |
115 | |
116 | static int ffs_copyonwrite(void *, struct buf *, bool); |
117 | static int snapblkaddr(struct vnode *, daddr_t, daddr_t *); |
118 | static int rwfsblk(struct vnode *, int, void *, daddr_t); |
119 | static int syncsnap(struct vnode *); |
120 | static int wrsnapblk(struct vnode *, void *, daddr_t); |
121 | #if !defined(FFS_NO_SNAPSHOT) |
122 | static int blocks_in_journal(struct fs *); |
123 | #endif |
124 | |
125 | static inline bool is_active_snapshot(struct snap_info *, struct inode *); |
126 | static inline daddr_t db_get(struct inode *, int); |
127 | static inline void db_assign(struct inode *, int, daddr_t); |
128 | static inline daddr_t ib_get(struct inode *, int); |
129 | static inline daddr_t idb_get(struct inode *, void *, int); |
130 | static inline void idb_assign(struct inode *, void *, int, daddr_t); |
131 | |
132 | #ifdef DEBUG |
133 | static int snapdebug = 0; |
134 | #endif |
135 | |
136 | int |
137 | ffs_snapshot_init(struct ufsmount *ump) |
138 | { |
139 | struct snap_info *si; |
140 | |
141 | si = ump->um_snapinfo = kmem_alloc(sizeof(*si), KM_SLEEP); |
142 | if (si == NULL) |
143 | return ENOMEM; |
144 | |
145 | TAILQ_INIT(&si->si_snapshots); |
146 | mutex_init(&si->si_lock, MUTEX_DEFAULT, IPL_NONE); |
147 | mutex_init(&si->si_snaplock, MUTEX_DEFAULT, IPL_NONE); |
148 | si->si_owner = NULL; |
149 | si->si_gen = 0; |
150 | si->si_snapblklist = NULL; |
151 | |
152 | return 0; |
153 | } |
154 | |
155 | void |
156 | ffs_snapshot_fini(struct ufsmount *ump) |
157 | { |
158 | struct snap_info *si; |
159 | |
160 | si = ump->um_snapinfo; |
161 | ump->um_snapinfo = NULL; |
162 | |
163 | KASSERT(TAILQ_EMPTY(&si->si_snapshots)); |
164 | mutex_destroy(&si->si_lock); |
165 | mutex_destroy(&si->si_snaplock); |
166 | KASSERT(si->si_snapblklist == NULL); |
167 | kmem_free(si, sizeof(*si)); |
168 | } |
169 | |
170 | /* |
171 | * Create a snapshot file and initialize it for the filesystem. |
172 | * Vnode is locked on entry and return. |
173 | */ |
174 | int |
175 | ffs_snapshot(struct mount *mp, struct vnode *vp, struct timespec *ctime) |
176 | { |
177 | #if defined(FFS_NO_SNAPSHOT) |
178 | return EOPNOTSUPP; |
179 | } |
180 | #else /* defined(FFS_NO_SNAPSHOT) */ |
181 | bool suspended = false; |
182 | int error, redo = 0, snaploc; |
183 | void *sbbuf = NULL; |
184 | daddr_t *snaplist = NULL, snaplistsize = 0; |
185 | struct buf *bp, *nbp; |
186 | struct fs *copy_fs = NULL; |
187 | struct fs *fs = VFSTOUFS(mp)->um_fs; |
188 | struct inode *ip = VTOI(vp); |
189 | struct lwp *l = curlwp; |
190 | struct snap_info *si = VFSTOUFS(mp)->um_snapinfo; |
191 | struct timespec ts; |
192 | struct timeval starttime; |
193 | #ifdef DEBUG |
194 | struct timeval endtime; |
195 | #endif |
196 | struct vnode *devvp = ip->i_devvp; |
197 | |
198 | /* |
199 | * If the vnode already is a snapshot, return. |
200 | */ |
201 | if ((ip->i_flags & SF_SNAPSHOT)) { |
202 | if ((ip->i_flags & SF_SNAPINVAL)) |
203 | return EINVAL; |
204 | if (ctime) { |
205 | ctime->tv_sec = DIP(ip, mtime); |
206 | ctime->tv_nsec = DIP(ip, mtimensec); |
207 | } |
208 | return 0; |
209 | } |
210 | /* |
211 | * Check for free snapshot slot in the superblock. |
212 | */ |
213 | for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++) |
214 | if (fs->fs_snapinum[snaploc] == 0) |
215 | break; |
216 | if (snaploc == FSMAXSNAP) |
217 | return (ENOSPC); |
218 | /* |
219 | * Prepare the vnode to become a snapshot. |
220 | */ |
221 | error = snapshot_setup(mp, vp); |
222 | if (error) |
223 | goto out; |
224 | |
225 | /* |
226 | * Copy all the cylinder group maps. Although the |
227 | * filesystem is still active, we hope that only a few |
228 | * cylinder groups will change between now and when we |
229 | * suspend operations. Thus, we will be able to quickly |
230 | * touch up the few cylinder groups that changed during |
231 | * the suspension period. |
232 | */ |
233 | error = cgaccount(vp, 1, NULL); |
234 | if (error) |
235 | goto out; |
236 | |
237 | /* |
238 | * snapshot is now valid |
239 | */ |
240 | ip->i_flags &= ~SF_SNAPINVAL; |
241 | DIP_ASSIGN(ip, flags, ip->i_flags); |
242 | ip->i_flag |= IN_CHANGE | IN_UPDATE; |
243 | |
244 | /* |
245 | * Ensure that the snapshot is completely on disk. |
246 | * Since we have marked it as a snapshot it is safe to |
247 | * unlock it as no process will be allowed to write to it. |
248 | */ |
249 | error = VOP_FSYNC(vp, l->l_cred, FSYNC_WAIT, 0, 0); |
250 | if (error) |
251 | goto out; |
252 | VOP_UNLOCK(vp); |
253 | /* |
254 | * All allocations are done, so we can now suspend the filesystem. |
255 | */ |
256 | error = vfs_suspend(vp->v_mount, 0); |
257 | vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); |
258 | if (error) |
259 | goto out; |
260 | suspended = true; |
261 | getmicrotime(&starttime); |
262 | /* |
263 | * First, copy all the cylinder group maps that have changed. |
264 | */ |
265 | error = cgaccount(vp, 2, &redo); |
266 | if (error) |
267 | goto out; |
268 | /* |
269 | * Create a copy of the superblock and its summary information. |
270 | */ |
271 | error = snapshot_copyfs(mp, vp, &sbbuf); |
272 | if (error) |
273 | goto out; |
274 | copy_fs = (struct fs *)((char *)sbbuf + ffs_blkoff(fs, fs->fs_sblockloc)); |
275 | /* |
276 | * Expunge unlinked files from our view. |
277 | */ |
278 | error = snapshot_expunge(mp, vp, copy_fs, &snaplistsize, &snaplist); |
279 | if (error) |
280 | goto out; |
281 | /* |
282 | * Record snapshot inode. Since this is the newest snapshot, |
283 | * it must be placed at the end of the list. |
284 | */ |
285 | if (ip->i_nlink > 0) |
286 | fs->fs_snapinum[snaploc] = ip->i_number; |
287 | |
288 | mutex_enter(&si->si_lock); |
289 | if (is_active_snapshot(si, ip)) |
290 | panic("ffs_snapshot: %" PRIu64" already on list" , ip->i_number); |
291 | TAILQ_INSERT_TAIL(&si->si_snapshots, ip, i_nextsnap); |
292 | if (TAILQ_FIRST(&si->si_snapshots) == ip) { |
293 | /* |
294 | * If this is the first snapshot on this filesystem, put the |
295 | * preliminary list in place and establish the cow handler. |
296 | */ |
297 | si->si_snapblklist = snaplist; |
298 | fscow_establish(mp, ffs_copyonwrite, devvp); |
299 | } |
300 | si->si_gen++; |
301 | mutex_exit(&si->si_lock); |
302 | |
303 | vp->v_vflag |= VV_SYSTEM; |
304 | /* |
305 | * Set the mtime to the time the snapshot has been taken. |
306 | */ |
307 | TIMEVAL_TO_TIMESPEC(&starttime, &ts); |
308 | if (ctime) |
309 | *ctime = ts; |
310 | DIP_ASSIGN(ip, mtime, ts.tv_sec); |
311 | DIP_ASSIGN(ip, mtimensec, ts.tv_nsec); |
312 | ip->i_flag |= IN_CHANGE | IN_UPDATE; |
313 | /* |
314 | * Copy allocation information from all snapshots and then |
315 | * expunge them from our view. |
316 | */ |
317 | error = snapshot_expunge_snap(mp, vp, copy_fs, snaplistsize); |
318 | if (error) |
319 | goto out; |
320 | /* |
321 | * Write the superblock and its summary information to the snapshot. |
322 | */ |
323 | error = snapshot_writefs(mp, vp, sbbuf); |
324 | if (error) |
325 | goto out; |
326 | /* |
327 | * We're nearly done, ensure that the snapshot is completely on disk. |
328 | */ |
329 | error = VOP_FSYNC(vp, l->l_cred, FSYNC_WAIT, 0, 0); |
330 | if (error) |
331 | goto out; |
332 | /* |
333 | * Invalidate and free all pages on the snapshot vnode. |
334 | * We will read and write through the buffercache. |
335 | */ |
336 | mutex_enter(vp->v_interlock); |
337 | error = VOP_PUTPAGES(vp, 0, 0, |
338 | PGO_ALLPAGES | PGO_CLEANIT | PGO_SYNCIO | PGO_FREE); |
339 | if (error) |
340 | goto out; |
341 | /* |
342 | * Invalidate short ( < fs_bsize ) buffers. We will always read |
343 | * full size buffers later. |
344 | */ |
345 | mutex_enter(&bufcache_lock); |
346 | KASSERT(LIST_FIRST(&vp->v_dirtyblkhd) == NULL); |
347 | for (bp = LIST_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) { |
348 | nbp = LIST_NEXT(bp, b_vnbufs); |
349 | if (bp->b_bcount == fs->fs_bsize) |
350 | continue; |
351 | error = bbusy(bp, false, 0, NULL); |
352 | if (error != 0) { |
353 | if (error == EPASSTHROUGH) { |
354 | nbp = LIST_FIRST(&vp->v_cleanblkhd); |
355 | continue; |
356 | } |
357 | break; |
358 | } |
359 | brelsel(bp, BC_INVAL | BC_VFLUSH); |
360 | } |
361 | mutex_exit(&bufcache_lock); |
362 | |
363 | out: |
364 | if (sbbuf != NULL) { |
365 | free(copy_fs->fs_csp, M_UFSMNT); |
366 | free(sbbuf, M_UFSMNT); |
367 | } |
368 | if (fs->fs_active != NULL) { |
369 | free(fs->fs_active, M_DEVBUF); |
370 | fs->fs_active = NULL; |
371 | } |
372 | |
373 | mutex_enter(&si->si_lock); |
374 | if (snaplist != NULL) { |
375 | if (si->si_snapblklist == snaplist) |
376 | si->si_snapblklist = NULL; |
377 | free(snaplist, M_UFSMNT); |
378 | } |
379 | if (error) { |
380 | fs->fs_snapinum[snaploc] = 0; |
381 | } else { |
382 | /* |
383 | * As this is the newest list, it is the most inclusive, so |
384 | * should replace the previous list. |
385 | */ |
386 | si->si_snapblklist = ip->i_snapblklist; |
387 | } |
388 | si->si_gen++; |
389 | mutex_exit(&si->si_lock); |
390 | |
391 | if (suspended) { |
392 | VOP_UNLOCK(vp); |
393 | vfs_resume(vp->v_mount); |
394 | vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); |
395 | #ifdef DEBUG |
396 | getmicrotime(&endtime); |
397 | timersub(&endtime, &starttime, &endtime); |
398 | printf("%s: suspended %lld.%03d sec, redo %d of %d\n" , |
399 | mp->mnt_stat.f_mntonname, (long long)endtime.tv_sec, |
400 | endtime.tv_usec / 1000, redo, fs->fs_ncg); |
401 | #endif |
402 | } |
403 | if (error) { |
404 | if (UFS_WAPBL_BEGIN(mp) == 0) { |
405 | /* |
406 | * We depend on ffs_truncate() to call ffs_snapremove() |
407 | * before it may return an error. On failed |
408 | * ffs_truncate() we have normal file with leaked |
409 | * (meta-) data, but no snapshot to use. |
410 | */ |
411 | (void) ffs_truncate(vp, (off_t)0, 0, NOCRED); |
412 | UFS_WAPBL_END(mp); |
413 | } |
414 | } else if (ip->i_nlink > 0) |
415 | vref(vp); |
416 | return (error); |
417 | } |
418 | |
419 | /* |
420 | * Prepare vnode to become a snapshot. |
421 | */ |
422 | static int |
423 | snapshot_setup(struct mount *mp, struct vnode *vp) |
424 | { |
425 | int error, n, len, loc, cg; |
426 | daddr_t blkno, numblks; |
427 | struct buf *ibp, *nbp; |
428 | struct fs *fs = VFSTOUFS(mp)->um_fs; |
429 | struct lwp *l = curlwp; |
430 | const int wbreak = blocks_in_journal(fs)/8; |
431 | struct inode *ip = VTOI(vp); |
432 | |
433 | /* |
434 | * Check mount, readonly reference and owner. |
435 | */ |
436 | if (vp->v_mount != mp) |
437 | return EXDEV; |
438 | if (vp->v_writecount != 0) |
439 | return EBUSY; |
440 | error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_FS_SNAPSHOT, |
441 | 0, mp, vp, NULL); |
442 | if (error) |
443 | return EACCES; |
444 | |
445 | if (vp->v_size != 0) { |
446 | /* |
447 | * Must completely truncate the file here. Allocated |
448 | * blocks on a snapshot mean that block has been copied |
449 | * on write, see ffs_copyonwrite() testing "blkno != 0" |
450 | */ |
451 | error = ufs_truncate_retry(vp, 0, NOCRED); |
452 | if (error) |
453 | return error; |
454 | } |
455 | |
456 | /* Change inode to snapshot type file. */ |
457 | error = UFS_WAPBL_BEGIN(mp); |
458 | if (error) |
459 | return error; |
460 | #if defined(QUOTA) || defined(QUOTA2) |
461 | /* shapshot inodes are not accounted in quotas */ |
462 | chkiq(ip, -1, l->l_cred, 0); |
463 | #endif |
464 | ip->i_flags |= (SF_SNAPSHOT | SF_SNAPINVAL); |
465 | DIP_ASSIGN(ip, flags, ip->i_flags); |
466 | ip->i_flag |= IN_CHANGE | IN_UPDATE; |
467 | ffs_update(vp, NULL, NULL, UPDATE_WAIT); |
468 | UFS_WAPBL_END(mp); |
469 | |
470 | KASSERT(ip->i_flags & SF_SNAPSHOT); |
471 | /* |
472 | * Write an empty list of preallocated blocks to the end of |
473 | * the snapshot to set size to at least that of the filesystem. |
474 | */ |
475 | numblks = howmany(fs->fs_size, fs->fs_frag); |
476 | blkno = 1; |
477 | blkno = ufs_rw64(blkno, UFS_FSNEEDSWAP(fs)); |
478 | error = vn_rdwr(UIO_WRITE, vp, |
479 | (void *)&blkno, sizeof(blkno), ffs_lblktosize(fs, (off_t)numblks), |
480 | UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, l->l_cred, NULL, NULL); |
481 | if (error) |
482 | return error; |
483 | /* |
484 | * Preallocate critical data structures so that we can copy |
485 | * them in without further allocation after we suspend all |
486 | * operations on the filesystem. We would like to just release |
487 | * the allocated buffers without writing them since they will |
488 | * be filled in below once we are ready to go, but this upsets |
489 | * the soft update code, so we go ahead and write the new buffers. |
490 | * |
491 | * Allocate all indirect blocks and mark all of them as not |
492 | * needing to be copied. |
493 | */ |
494 | error = UFS_WAPBL_BEGIN(mp); |
495 | if (error) |
496 | return error; |
497 | for (blkno = UFS_NDADDR, n = 0; blkno < numblks; blkno += FFS_NINDIR(fs)) { |
498 | error = ffs_balloc(vp, ffs_lblktosize(fs, (off_t)blkno), |
499 | fs->fs_bsize, l->l_cred, B_METAONLY, &ibp); |
500 | if (error) |
501 | goto out; |
502 | brelse(ibp, 0); |
503 | if (wbreak > 0 && (++n % wbreak) == 0) { |
504 | UFS_WAPBL_END(mp); |
505 | error = UFS_WAPBL_BEGIN(mp); |
506 | if (error) |
507 | return error; |
508 | } |
509 | } |
510 | /* |
511 | * Allocate copies for the superblock and its summary information. |
512 | */ |
513 | error = ffs_balloc(vp, fs->fs_sblockloc, fs->fs_sbsize, l->l_cred, |
514 | 0, &nbp); |
515 | if (error) |
516 | goto out; |
517 | bawrite(nbp); |
518 | blkno = ffs_fragstoblks(fs, fs->fs_csaddr); |
519 | len = howmany(fs->fs_cssize, fs->fs_bsize); |
520 | for (loc = 0; loc < len; loc++) { |
521 | error = ffs_balloc(vp, ffs_lblktosize(fs, (off_t)(blkno + loc)), |
522 | fs->fs_bsize, l->l_cred, 0, &nbp); |
523 | if (error) |
524 | goto out; |
525 | bawrite(nbp); |
526 | if (wbreak > 0 && (++n % wbreak) == 0) { |
527 | UFS_WAPBL_END(mp); |
528 | error = UFS_WAPBL_BEGIN(mp); |
529 | if (error) |
530 | return error; |
531 | } |
532 | } |
533 | /* |
534 | * Allocate all cylinder group blocks. |
535 | */ |
536 | for (cg = 0; cg < fs->fs_ncg; cg++) { |
537 | error = ffs_balloc(vp, ffs_lfragtosize(fs, cgtod(fs, cg)), |
538 | fs->fs_bsize, l->l_cred, 0, &nbp); |
539 | if (error) |
540 | goto out; |
541 | bawrite(nbp); |
542 | if (wbreak > 0 && (++n % wbreak) == 0) { |
543 | UFS_WAPBL_END(mp); |
544 | error = UFS_WAPBL_BEGIN(mp); |
545 | if (error) |
546 | return error; |
547 | } |
548 | } |
549 | |
550 | out: |
551 | UFS_WAPBL_END(mp); |
552 | return error; |
553 | } |
554 | |
555 | /* |
556 | * Create a copy of the superblock and its summary information. |
557 | * It is up to the caller to free copyfs and copy_fs->fs_csp. |
558 | */ |
559 | static int |
560 | snapshot_copyfs(struct mount *mp, struct vnode *vp, void **sbbuf) |
561 | { |
562 | int error, i, len, loc, size; |
563 | void *space; |
564 | int32_t *lp; |
565 | struct buf *bp; |
566 | struct fs *copyfs, *fs = VFSTOUFS(mp)->um_fs; |
567 | struct vnode *devvp = VTOI(vp)->i_devvp; |
568 | |
569 | /* |
570 | * Grab a copy of the superblock and its summary information. |
571 | * We delay writing it until the suspension is released below. |
572 | */ |
573 | *sbbuf = malloc(fs->fs_bsize, M_UFSMNT, M_WAITOK); |
574 | loc = ffs_blkoff(fs, fs->fs_sblockloc); |
575 | if (loc > 0) |
576 | memset(*sbbuf, 0, loc); |
577 | copyfs = (struct fs *)((char *)(*sbbuf) + loc); |
578 | memcpy(copyfs, fs, fs->fs_sbsize); |
579 | size = fs->fs_bsize < SBLOCKSIZE ? fs->fs_bsize : SBLOCKSIZE; |
580 | if (fs->fs_sbsize < size) |
581 | memset((char *)(*sbbuf) + loc + fs->fs_sbsize, 0, |
582 | size - fs->fs_sbsize); |
583 | size = ffs_blkroundup(fs, fs->fs_cssize); |
584 | if (fs->fs_contigsumsize > 0) |
585 | size += fs->fs_ncg * sizeof(int32_t); |
586 | space = malloc(size, M_UFSMNT, M_WAITOK); |
587 | copyfs->fs_csp = space; |
588 | memcpy(copyfs->fs_csp, fs->fs_csp, fs->fs_cssize); |
589 | space = (char *)space + fs->fs_cssize; |
590 | loc = howmany(fs->fs_cssize, fs->fs_fsize); |
591 | i = fs->fs_frag - loc % fs->fs_frag; |
592 | len = (i == fs->fs_frag) ? 0 : i * fs->fs_fsize; |
593 | if (len > 0) { |
594 | if ((error = bread(devvp, FFS_FSBTODB(fs, fs->fs_csaddr + loc), |
595 | len, 0, &bp)) != 0) { |
596 | free(copyfs->fs_csp, M_UFSMNT); |
597 | free(*sbbuf, M_UFSMNT); |
598 | *sbbuf = NULL; |
599 | return error; |
600 | } |
601 | memcpy(space, bp->b_data, (u_int)len); |
602 | space = (char *)space + len; |
603 | brelse(bp, BC_INVAL | BC_NOCACHE); |
604 | } |
605 | if (fs->fs_contigsumsize > 0) { |
606 | copyfs->fs_maxcluster = lp = space; |
607 | for (i = 0; i < fs->fs_ncg; i++) |
608 | *lp++ = fs->fs_contigsumsize; |
609 | } |
610 | if (mp->mnt_wapbl) |
611 | copyfs->fs_flags &= ~FS_DOWAPBL; |
612 | return 0; |
613 | } |
614 | |
615 | struct snapshot_expunge_ctx { |
616 | struct vnode *logvp; |
617 | struct lwp *l; |
618 | struct vnode *vp; |
619 | struct fs *copy_fs; |
620 | }; |
621 | |
622 | static bool |
623 | snapshot_expunge_selector(void *cl, struct vnode *xvp) |
624 | { |
625 | struct vattr vat; |
626 | struct snapshot_expunge_ctx *c = cl; |
627 | struct inode *xp; |
628 | |
629 | xp = VTOI(xvp); |
630 | if (xvp->v_type == VNON || VTOI(xvp) == NULL || |
631 | (xp->i_flags & SF_SNAPSHOT)) |
632 | return false; |
633 | #ifdef DEBUG |
634 | if (snapdebug) |
635 | vprint("ffs_snapshot: busy vnode" , xvp); |
636 | #endif |
637 | |
638 | if (xvp == c->logvp) |
639 | return true; |
640 | |
641 | if (VOP_GETATTR(xvp, &vat, c->l->l_cred) == 0 && |
642 | vat.va_nlink > 0) |
643 | return false; |
644 | |
645 | if (ffs_checkfreefile(c->copy_fs, c->vp, xp->i_number)) |
646 | return false; |
647 | |
648 | return true; |
649 | } |
650 | |
651 | /* |
652 | * We must check for active files that have been unlinked (e.g., with a zero |
653 | * link count). We have to expunge all trace of these files from the snapshot |
654 | * so that they are not reclaimed prematurely by fsck or unnecessarily dumped. |
655 | * Note that we skip unlinked snapshot files as they will be handled separately. |
656 | * Calculate the snapshot list size and create a preliminary list. |
657 | */ |
658 | static int |
659 | snapshot_expunge(struct mount *mp, struct vnode *vp, struct fs *copy_fs, |
660 | daddr_t *snaplistsize, daddr_t **snaplist) |
661 | { |
662 | int cg, error = 0, len, loc; |
663 | daddr_t blkno, *blkp; |
664 | struct fs *fs = VFSTOUFS(mp)->um_fs; |
665 | struct inode *xp; |
666 | struct lwp *l = curlwp; |
667 | struct vnode *logvp = NULL, *xvp; |
668 | struct vnode_iterator *marker; |
669 | struct snapshot_expunge_ctx ctx; |
670 | |
671 | *snaplist = NULL; |
672 | /* |
673 | * Get the log inode if any. |
674 | */ |
675 | if ((fs->fs_flags & FS_DOWAPBL) && |
676 | fs->fs_journal_location == UFS_WAPBL_JOURNALLOC_IN_FILESYSTEM) { |
677 | error = VFS_VGET(mp, |
678 | fs->fs_journallocs[UFS_WAPBL_INFS_INO], &logvp); |
679 | if (error) |
680 | goto out; |
681 | } |
682 | /* |
683 | * We also calculate the needed size for the snapshot list. |
684 | */ |
685 | *snaplistsize = fs->fs_ncg + howmany(fs->fs_cssize, fs->fs_bsize) + |
686 | FSMAXSNAP + 1 /* superblock */ + 1 /* last block */ + 1 /* size */; |
687 | |
688 | vfs_vnode_iterator_init(mp, &marker); |
689 | ctx.logvp = logvp; |
690 | ctx.l = l; |
691 | ctx.vp = vp; |
692 | ctx.copy_fs = copy_fs; |
693 | while ((xvp = vfs_vnode_iterator_next(marker, snapshot_expunge_selector, |
694 | &ctx))) |
695 | { |
696 | /* |
697 | * If there is a fragment, clear it here. |
698 | */ |
699 | xp = VTOI(xvp); |
700 | blkno = 0; |
701 | loc = howmany(xp->i_size, fs->fs_bsize) - 1; |
702 | if (loc < UFS_NDADDR) { |
703 | len = ffs_fragroundup(fs, ffs_blkoff(fs, xp->i_size)); |
704 | if (len > 0 && len < fs->fs_bsize) { |
705 | error = UFS_WAPBL_BEGIN(mp); |
706 | if (error) { |
707 | vrele(xvp); |
708 | vfs_vnode_iterator_destroy(marker); |
709 | goto out; |
710 | } |
711 | ffs_blkfree_snap(copy_fs, vp, db_get(xp, loc), |
712 | len, xp->i_number); |
713 | blkno = db_get(xp, loc); |
714 | db_assign(xp, loc, 0); |
715 | UFS_WAPBL_END(mp); |
716 | } |
717 | } |
718 | *snaplistsize += 1; |
719 | error = expunge(vp, xp, copy_fs, fullacct, BLK_NOCOPY); |
720 | if (blkno) |
721 | db_assign(xp, loc, blkno); |
722 | if (!error) { |
723 | error = UFS_WAPBL_BEGIN(mp); |
724 | if (!error) { |
725 | error = ffs_freefile_snap(copy_fs, vp, |
726 | xp->i_number, xp->i_mode); |
727 | UFS_WAPBL_END(mp); |
728 | } |
729 | } |
730 | vrele(xvp); |
731 | if (error) { |
732 | vfs_vnode_iterator_destroy(marker); |
733 | goto out; |
734 | } |
735 | } |
736 | vfs_vnode_iterator_destroy(marker); |
737 | |
738 | /* |
739 | * Create a preliminary list of preallocated snapshot blocks. |
740 | */ |
741 | *snaplist = malloc(*snaplistsize * sizeof(daddr_t), M_UFSMNT, M_WAITOK); |
742 | blkp = &(*snaplist)[1]; |
743 | *blkp++ = ffs_lblkno(fs, fs->fs_sblockloc); |
744 | blkno = ffs_fragstoblks(fs, fs->fs_csaddr); |
745 | for (cg = 0; cg < fs->fs_ncg; cg++) { |
746 | if (ffs_fragstoblks(fs, cgtod(fs, cg)) > blkno) |
747 | break; |
748 | *blkp++ = ffs_fragstoblks(fs, cgtod(fs, cg)); |
749 | } |
750 | len = howmany(fs->fs_cssize, fs->fs_bsize); |
751 | for (loc = 0; loc < len; loc++) |
752 | *blkp++ = blkno + loc; |
753 | for (; cg < fs->fs_ncg; cg++) |
754 | *blkp++ = ffs_fragstoblks(fs, cgtod(fs, cg)); |
755 | (*snaplist)[0] = blkp - &(*snaplist)[0]; |
756 | |
757 | out: |
758 | if (logvp != NULL) |
759 | vput(logvp); |
760 | if (error && *snaplist != NULL) { |
761 | free(*snaplist, M_UFSMNT); |
762 | *snaplist = NULL; |
763 | } |
764 | |
765 | return error; |
766 | } |
767 | |
768 | /* |
769 | * Copy allocation information from all the snapshots in this snapshot and |
770 | * then expunge them from its view. Also, collect the list of allocated |
771 | * blocks in i_snapblklist. |
772 | */ |
773 | static int |
774 | snapshot_expunge_snap(struct mount *mp, struct vnode *vp, |
775 | struct fs *copy_fs, daddr_t snaplistsize) |
776 | { |
777 | int error = 0, i; |
778 | daddr_t numblks, *snaplist = NULL; |
779 | struct fs *fs = VFSTOUFS(mp)->um_fs; |
780 | struct inode *ip = VTOI(vp), *xp; |
781 | struct lwp *l = curlwp; |
782 | struct snap_info *si = VFSTOUFS(mp)->um_snapinfo; |
783 | |
784 | TAILQ_FOREACH(xp, &si->si_snapshots, i_nextsnap) { |
785 | if (xp != ip) { |
786 | error = expunge(vp, xp, fs, snapacct, BLK_SNAP); |
787 | if (error) |
788 | break; |
789 | } |
790 | if (xp->i_nlink != 0) |
791 | continue; |
792 | error = UFS_WAPBL_BEGIN(mp); |
793 | if (error) |
794 | break; |
795 | error = ffs_freefile_snap(copy_fs, vp, xp->i_number, xp->i_mode); |
796 | UFS_WAPBL_END(mp); |
797 | if (error) |
798 | break; |
799 | } |
800 | if (error) |
801 | goto out; |
802 | /* |
803 | * Allocate space for the full list of preallocated snapshot blocks. |
804 | */ |
805 | snaplist = malloc(snaplistsize * sizeof(daddr_t), M_UFSMNT, M_WAITOK); |
806 | ip->i_snapblklist = &snaplist[1]; |
807 | /* |
808 | * Expunge the blocks used by the snapshots from the set of |
809 | * blocks marked as used in the snapshot bitmaps. Also, collect |
810 | * the list of allocated blocks in i_snapblklist. |
811 | */ |
812 | error = expunge(vp, ip, copy_fs, mapacct, BLK_SNAP); |
813 | if (error) |
814 | goto out; |
815 | if (snaplistsize < ip->i_snapblklist - snaplist) |
816 | panic("ffs_snapshot: list too small" ); |
817 | snaplistsize = ip->i_snapblklist - snaplist; |
818 | snaplist[0] = snaplistsize; |
819 | ip->i_snapblklist = &snaplist[0]; |
820 | /* |
821 | * Write out the list of allocated blocks to the end of the snapshot. |
822 | */ |
823 | numblks = howmany(fs->fs_size, fs->fs_frag); |
824 | for (i = 0; i < snaplistsize; i++) |
825 | snaplist[i] = ufs_rw64(snaplist[i], UFS_FSNEEDSWAP(fs)); |
826 | error = vn_rdwr(UIO_WRITE, vp, (void *)snaplist, |
827 | snaplistsize * sizeof(daddr_t), ffs_lblktosize(fs, (off_t)numblks), |
828 | UIO_SYSSPACE, IO_NODELOCKED | IO_UNIT, l->l_cred, NULL, NULL); |
829 | for (i = 0; i < snaplistsize; i++) |
830 | snaplist[i] = ufs_rw64(snaplist[i], UFS_FSNEEDSWAP(fs)); |
831 | out: |
832 | if (error && snaplist != NULL) { |
833 | free(snaplist, M_UFSMNT); |
834 | ip->i_snapblklist = NULL; |
835 | } |
836 | return error; |
837 | } |
838 | |
839 | /* |
840 | * Write the superblock and its summary information to the snapshot. |
841 | * Make sure, the first UFS_NDADDR blocks get copied to the snapshot. |
842 | */ |
843 | static int |
844 | snapshot_writefs(struct mount *mp, struct vnode *vp, void *sbbuf) |
845 | { |
846 | int error, len, loc; |
847 | void *space; |
848 | daddr_t blkno; |
849 | struct buf *bp; |
850 | struct fs *copyfs, *fs = VFSTOUFS(mp)->um_fs; |
851 | struct inode *ip = VTOI(vp); |
852 | struct lwp *l = curlwp; |
853 | |
854 | copyfs = (struct fs *)((char *)sbbuf + ffs_blkoff(fs, fs->fs_sblockloc)); |
855 | |
856 | /* |
857 | * Write the superblock and its summary information |
858 | * to the snapshot. |
859 | */ |
860 | blkno = ffs_fragstoblks(fs, fs->fs_csaddr); |
861 | len = howmany(fs->fs_cssize, fs->fs_bsize); |
862 | space = copyfs->fs_csp; |
863 | #ifdef FFS_EI |
864 | if (UFS_FSNEEDSWAP(fs)) { |
865 | ffs_sb_swap(copyfs, copyfs); |
866 | ffs_csum_swap(space, space, fs->fs_cssize); |
867 | } |
868 | #endif |
869 | error = UFS_WAPBL_BEGIN(mp); |
870 | if (error) |
871 | return error; |
872 | for (loc = 0; loc < len; loc++) { |
873 | error = bread(vp, blkno + loc, fs->fs_bsize, |
874 | B_MODIFY, &bp); |
875 | if (error) { |
876 | break; |
877 | } |
878 | memcpy(bp->b_data, space, fs->fs_bsize); |
879 | space = (char *)space + fs->fs_bsize; |
880 | bawrite(bp); |
881 | } |
882 | if (error) |
883 | goto out; |
884 | error = bread(vp, ffs_lblkno(fs, fs->fs_sblockloc), |
885 | fs->fs_bsize, B_MODIFY, &bp); |
886 | if (error) { |
887 | goto out; |
888 | } else { |
889 | memcpy(bp->b_data, sbbuf, fs->fs_bsize); |
890 | bawrite(bp); |
891 | } |
892 | /* |
893 | * Copy the first UFS_NDADDR blocks to the snapshot so |
894 | * ffs_copyonwrite() and ffs_snapblkfree() will always work on |
895 | * indirect blocks. |
896 | */ |
897 | for (loc = 0; loc < UFS_NDADDR; loc++) { |
898 | if (db_get(ip, loc) != 0) |
899 | continue; |
900 | error = ffs_balloc(vp, ffs_lblktosize(fs, (off_t)loc), |
901 | fs->fs_bsize, l->l_cred, 0, &bp); |
902 | if (error) |
903 | break; |
904 | error = rwfsblk(vp, B_READ, bp->b_data, loc); |
905 | if (error) { |
906 | brelse(bp, 0); |
907 | break; |
908 | } |
909 | bawrite(bp); |
910 | } |
911 | |
912 | out: |
913 | UFS_WAPBL_END(mp); |
914 | return error; |
915 | } |
916 | |
917 | /* |
918 | * Copy all cylinder group maps. |
919 | */ |
920 | static int |
921 | cgaccount(struct vnode *vp, int passno, int *redo) |
922 | { |
923 | int cg, error = 0; |
924 | struct buf *nbp; |
925 | struct fs *fs = VTOI(vp)->i_fs; |
926 | |
927 | if (redo != NULL) |
928 | *redo = 0; |
929 | if (passno == 1) |
930 | fs->fs_active = malloc(howmany(fs->fs_ncg, NBBY), |
931 | M_DEVBUF, M_WAITOK | M_ZERO); |
932 | for (cg = 0; cg < fs->fs_ncg; cg++) { |
933 | if (passno == 2 && ACTIVECG_ISSET(fs, cg)) |
934 | continue; |
935 | |
936 | if (redo != NULL) |
937 | *redo += 1; |
938 | error = UFS_WAPBL_BEGIN(vp->v_mount); |
939 | if (error) |
940 | return error; |
941 | error = ffs_balloc(vp, ffs_lfragtosize(fs, cgtod(fs, cg)), |
942 | fs->fs_bsize, curlwp->l_cred, 0, &nbp); |
943 | if (error) { |
944 | UFS_WAPBL_END(vp->v_mount); |
945 | break; |
946 | } |
947 | error = cgaccount1(cg, vp, nbp->b_data, passno); |
948 | bawrite(nbp); |
949 | UFS_WAPBL_END(vp->v_mount); |
950 | if (error) |
951 | break; |
952 | } |
953 | return error; |
954 | } |
955 | |
956 | /* |
957 | * Copy a cylinder group map. All the unallocated blocks are marked |
958 | * BLK_NOCOPY so that the snapshot knows that it need not copy them |
959 | * if they are later written. If passno is one, then this is a first |
960 | * pass, so only setting needs to be done. If passno is 2, then this |
961 | * is a revision to a previous pass which must be undone as the |
962 | * replacement pass is done. |
963 | */ |
964 | static int |
965 | cgaccount1(int cg, struct vnode *vp, void *data, int passno) |
966 | { |
967 | struct buf *bp, *ibp; |
968 | struct inode *ip; |
969 | struct cg *cgp; |
970 | struct fs *fs; |
971 | struct lwp *l = curlwp; |
972 | daddr_t base, numblks; |
973 | int error, len, loc, ns __unused, indiroff; |
974 | |
975 | ip = VTOI(vp); |
976 | fs = ip->i_fs; |
977 | ns = UFS_FSNEEDSWAP(fs); |
978 | error = bread(ip->i_devvp, FFS_FSBTODB(fs, cgtod(fs, cg)), |
979 | (int)fs->fs_cgsize, 0, &bp); |
980 | if (error) { |
981 | return (error); |
982 | } |
983 | cgp = (struct cg *)bp->b_data; |
984 | if (!cg_chkmagic(cgp, ns)) { |
985 | brelse(bp, 0); |
986 | return (EIO); |
987 | } |
988 | ACTIVECG_SET(fs, cg); |
989 | |
990 | memcpy(data, bp->b_data, fs->fs_cgsize); |
991 | brelse(bp, 0); |
992 | if (fs->fs_cgsize < fs->fs_bsize) |
993 | memset((char *)data + fs->fs_cgsize, 0, |
994 | fs->fs_bsize - fs->fs_cgsize); |
995 | numblks = howmany(fs->fs_size, fs->fs_frag); |
996 | len = howmany(fs->fs_fpg, fs->fs_frag); |
997 | base = cg * fs->fs_fpg / fs->fs_frag; |
998 | if (base + len >= numblks) |
999 | len = numblks - base - 1; |
1000 | loc = 0; |
1001 | if (base < UFS_NDADDR) { |
1002 | for ( ; loc < UFS_NDADDR; loc++) { |
1003 | if (ffs_isblock(fs, cg_blksfree(cgp, ns), loc)) |
1004 | db_assign(ip, loc, BLK_NOCOPY); |
1005 | else if (db_get(ip, loc) == BLK_NOCOPY) { |
1006 | if (passno == 2) |
1007 | db_assign(ip, loc, 0); |
1008 | else if (passno == 1) |
1009 | panic("ffs_snapshot: lost direct block" ); |
1010 | } |
1011 | } |
1012 | } |
1013 | if ((error = ffs_balloc(vp, ffs_lblktosize(fs, (off_t)(base + loc)), |
1014 | fs->fs_bsize, l->l_cred, B_METAONLY, &ibp)) != 0) |
1015 | return (error); |
1016 | indiroff = (base + loc - UFS_NDADDR) % FFS_NINDIR(fs); |
1017 | for ( ; loc < len; loc++, indiroff++) { |
1018 | if (indiroff >= FFS_NINDIR(fs)) { |
1019 | bawrite(ibp); |
1020 | if ((error = ffs_balloc(vp, |
1021 | ffs_lblktosize(fs, (off_t)(base + loc)), |
1022 | fs->fs_bsize, l->l_cred, B_METAONLY, &ibp)) != 0) |
1023 | return (error); |
1024 | indiroff = 0; |
1025 | } |
1026 | if (ffs_isblock(fs, cg_blksfree(cgp, ns), loc)) |
1027 | idb_assign(ip, ibp->b_data, indiroff, BLK_NOCOPY); |
1028 | else if (idb_get(ip, ibp->b_data, indiroff) == BLK_NOCOPY) { |
1029 | if (passno == 2) |
1030 | idb_assign(ip, ibp->b_data, indiroff, 0); |
1031 | else if (passno == 1) |
1032 | panic("ffs_snapshot: lost indirect block" ); |
1033 | } |
1034 | } |
1035 | bdwrite(ibp); |
1036 | return (0); |
1037 | } |
1038 | |
1039 | /* |
1040 | * Before expunging a snapshot inode, note all the |
1041 | * blocks that it claims with BLK_SNAP so that fsck will |
1042 | * be able to account for those blocks properly and so |
1043 | * that this snapshot knows that it need not copy them |
1044 | * if the other snapshot holding them is freed. |
1045 | */ |
1046 | static int |
1047 | expunge(struct vnode *snapvp, struct inode *cancelip, struct fs *fs, |
1048 | acctfunc_t acctfunc, int expungetype) |
1049 | { |
1050 | int i, error, ns __unused; |
1051 | daddr_t lbn, rlbn; |
1052 | daddr_t len, blkno, numblks, blksperindir; |
1053 | struct ufs1_dinode *dip1; |
1054 | struct ufs2_dinode *dip2; |
1055 | struct lwp *l = curlwp; |
1056 | void *bap; |
1057 | struct buf *bp; |
1058 | struct mount *mp; |
1059 | |
1060 | ns = UFS_FSNEEDSWAP(fs); |
1061 | mp = snapvp->v_mount; |
1062 | |
1063 | error = UFS_WAPBL_BEGIN(mp); |
1064 | if (error) |
1065 | return error; |
1066 | /* |
1067 | * Prepare to expunge the inode. If its inode block has not |
1068 | * yet been copied, then allocate and fill the copy. |
1069 | */ |
1070 | lbn = ffs_fragstoblks(fs, ino_to_fsba(fs, cancelip->i_number)); |
1071 | error = snapblkaddr(snapvp, lbn, &blkno); |
1072 | if (error) |
1073 | return error; |
1074 | if (blkno != 0) { |
1075 | error = bread(snapvp, lbn, fs->fs_bsize, |
1076 | B_MODIFY, &bp); |
1077 | } else { |
1078 | error = ffs_balloc(snapvp, ffs_lblktosize(fs, (off_t)lbn), |
1079 | fs->fs_bsize, l->l_cred, 0, &bp); |
1080 | if (! error) |
1081 | error = rwfsblk(snapvp, B_READ, bp->b_data, lbn); |
1082 | } |
1083 | if (error) { |
1084 | UFS_WAPBL_END(mp); |
1085 | return error; |
1086 | } |
1087 | /* |
1088 | * Set a snapshot inode to be a zero length file, regular files |
1089 | * or unlinked snapshots to be completely unallocated. |
1090 | */ |
1091 | if (fs->fs_magic == FS_UFS1_MAGIC) { |
1092 | dip1 = (struct ufs1_dinode *)bp->b_data + |
1093 | ino_to_fsbo(fs, cancelip->i_number); |
1094 | if (cancelip->i_flags & SF_SNAPSHOT) { |
1095 | dip1->di_flags = |
1096 | ufs_rw32(ufs_rw32(dip1->di_flags, ns) | |
1097 | SF_SNAPINVAL, ns); |
1098 | } |
1099 | if (expungetype == BLK_NOCOPY || cancelip->i_nlink == 0) |
1100 | dip1->di_mode = 0; |
1101 | dip1->di_size = 0; |
1102 | dip1->di_blocks = 0; |
1103 | memset(&dip1->di_db[0], 0, (UFS_NDADDR + UFS_NIADDR) * sizeof(int32_t)); |
1104 | } else { |
1105 | dip2 = (struct ufs2_dinode *)bp->b_data + |
1106 | ino_to_fsbo(fs, cancelip->i_number); |
1107 | if (cancelip->i_flags & SF_SNAPSHOT) { |
1108 | dip2->di_flags = |
1109 | ufs_rw32(ufs_rw32(dip2->di_flags, ns) | |
1110 | SF_SNAPINVAL, ns); |
1111 | } |
1112 | if (expungetype == BLK_NOCOPY || cancelip->i_nlink == 0) |
1113 | dip2->di_mode = 0; |
1114 | dip2->di_size = 0; |
1115 | dip2->di_blocks = 0; |
1116 | memset(&dip2->di_db[0], 0, (UFS_NDADDR + UFS_NIADDR) * sizeof(int64_t)); |
1117 | } |
1118 | bdwrite(bp); |
1119 | UFS_WAPBL_END(mp); |
1120 | /* |
1121 | * Now go through and expunge all the blocks in the file |
1122 | * using the function requested. |
1123 | */ |
1124 | numblks = howmany(cancelip->i_size, fs->fs_bsize); |
1125 | if (fs->fs_magic == FS_UFS1_MAGIC) |
1126 | bap = &cancelip->i_ffs1_db[0]; |
1127 | else |
1128 | bap = &cancelip->i_ffs2_db[0]; |
1129 | error = (*acctfunc)(snapvp, bap, 0, UFS_NDADDR, fs, 0, expungetype); |
1130 | if (error) |
1131 | return (error); |
1132 | if (fs->fs_magic == FS_UFS1_MAGIC) |
1133 | bap = &cancelip->i_ffs1_ib[0]; |
1134 | else |
1135 | bap = &cancelip->i_ffs2_ib[0]; |
1136 | error = (*acctfunc)(snapvp, bap, 0, UFS_NIADDR, fs, -1, expungetype); |
1137 | if (error) |
1138 | return (error); |
1139 | blksperindir = 1; |
1140 | lbn = -UFS_NDADDR; |
1141 | len = numblks - UFS_NDADDR; |
1142 | rlbn = UFS_NDADDR; |
1143 | for (i = 0; len > 0 && i < UFS_NIADDR; i++) { |
1144 | error = indiracct(snapvp, ITOV(cancelip), i, |
1145 | ib_get(cancelip, i), lbn, rlbn, len, |
1146 | blksperindir, fs, acctfunc, expungetype); |
1147 | if (error) |
1148 | return (error); |
1149 | blksperindir *= FFS_NINDIR(fs); |
1150 | lbn -= blksperindir + 1; |
1151 | len -= blksperindir; |
1152 | rlbn += blksperindir; |
1153 | } |
1154 | return (0); |
1155 | } |
1156 | |
1157 | /* |
1158 | * Descend an indirect block chain for vnode cancelvp accounting for all |
1159 | * its indirect blocks in snapvp. |
1160 | */ |
1161 | static int |
1162 | indiracct(struct vnode *snapvp, struct vnode *cancelvp, int level, |
1163 | daddr_t blkno, daddr_t lbn, daddr_t rlbn, daddr_t remblks, |
1164 | daddr_t blksperindir, struct fs *fs, acctfunc_t acctfunc, int expungetype) |
1165 | { |
1166 | int error, num, i; |
1167 | daddr_t subblksperindir; |
1168 | struct indir indirs[UFS_NIADDR + 2]; |
1169 | daddr_t last; |
1170 | void *bap; |
1171 | struct buf *bp; |
1172 | |
1173 | if (blkno == 0) { |
1174 | if (expungetype == BLK_NOCOPY) |
1175 | return (0); |
1176 | panic("indiracct: missing indir" ); |
1177 | } |
1178 | if ((error = ufs_getlbns(cancelvp, rlbn, indirs, &num)) != 0) |
1179 | return (error); |
1180 | if (lbn != indirs[num - 1 - level].in_lbn || num < 2) |
1181 | panic("indiracct: botched params" ); |
1182 | /* |
1183 | * We have to expand bread here since it will deadlock looking |
1184 | * up the block number for any blocks that are not in the cache. |
1185 | */ |
1186 | error = ffs_getblk(cancelvp, lbn, FFS_FSBTODB(fs, blkno), fs->fs_bsize, |
1187 | false, &bp); |
1188 | if (error) |
1189 | return error; |
1190 | if ((bp->b_oflags & (BO_DONE | BO_DELWRI)) == 0 && (error = |
1191 | rwfsblk(bp->b_vp, B_READ, bp->b_data, ffs_fragstoblks(fs, blkno)))) { |
1192 | brelse(bp, 0); |
1193 | return (error); |
1194 | } |
1195 | /* |
1196 | * Account for the block pointers in this indirect block. |
1197 | */ |
1198 | last = howmany(remblks, blksperindir); |
1199 | if (last > FFS_NINDIR(fs)) |
1200 | last = FFS_NINDIR(fs); |
1201 | bap = malloc(fs->fs_bsize, M_DEVBUF, M_WAITOK | M_ZERO); |
1202 | memcpy((void *)bap, bp->b_data, fs->fs_bsize); |
1203 | brelse(bp, 0); |
1204 | error = (*acctfunc)(snapvp, bap, 0, last, |
1205 | fs, level == 0 ? rlbn : -1, expungetype); |
1206 | if (error || level == 0) |
1207 | goto out; |
1208 | /* |
1209 | * Account for the block pointers in each of the indirect blocks |
1210 | * in the levels below us. |
1211 | */ |
1212 | subblksperindir = blksperindir / FFS_NINDIR(fs); |
1213 | for (lbn++, level--, i = 0; i < last; i++) { |
1214 | error = indiracct(snapvp, cancelvp, level, |
1215 | idb_get(VTOI(snapvp), bap, i), lbn, rlbn, remblks, |
1216 | subblksperindir, fs, acctfunc, expungetype); |
1217 | if (error) |
1218 | goto out; |
1219 | rlbn += blksperindir; |
1220 | lbn -= blksperindir; |
1221 | remblks -= blksperindir; |
1222 | } |
1223 | out: |
1224 | free(bap, M_DEVBUF); |
1225 | return (error); |
1226 | } |
1227 | |
1228 | /* |
1229 | * Do both snap accounting and map accounting. |
1230 | */ |
1231 | static int |
1232 | fullacct(struct vnode *vp, void *bap, int oldblkp, int lastblkp, |
1233 | struct fs *fs, daddr_t lblkno, |
1234 | int exptype /* BLK_SNAP or BLK_NOCOPY */) |
1235 | { |
1236 | int error; |
1237 | |
1238 | if ((error = snapacct(vp, bap, oldblkp, lastblkp, fs, lblkno, exptype))) |
1239 | return (error); |
1240 | return (mapacct(vp, bap, oldblkp, lastblkp, fs, lblkno, exptype)); |
1241 | } |
1242 | |
1243 | /* |
1244 | * Identify a set of blocks allocated in a snapshot inode. |
1245 | */ |
1246 | static int |
1247 | snapacct(struct vnode *vp, void *bap, int oldblkp, int lastblkp, |
1248 | struct fs *fs, daddr_t lblkno, |
1249 | int expungetype /* BLK_SNAP or BLK_NOCOPY */) |
1250 | { |
1251 | struct inode *ip = VTOI(vp); |
1252 | struct lwp *l = curlwp; |
1253 | struct mount *mp = vp->v_mount; |
1254 | daddr_t blkno; |
1255 | daddr_t lbn; |
1256 | struct buf *ibp; |
1257 | int error, n; |
1258 | const int wbreak = blocks_in_journal(VFSTOUFS(mp)->um_fs)/8; |
1259 | |
1260 | error = UFS_WAPBL_BEGIN(mp); |
1261 | if (error) |
1262 | return error; |
1263 | for ( n = 0; oldblkp < lastblkp; oldblkp++) { |
1264 | blkno = idb_get(ip, bap, oldblkp); |
1265 | if (blkno == 0 || blkno == BLK_NOCOPY || blkno == BLK_SNAP) |
1266 | continue; |
1267 | lbn = ffs_fragstoblks(fs, blkno); |
1268 | if (lbn < UFS_NDADDR) { |
1269 | blkno = db_get(ip, lbn); |
1270 | ip->i_flag |= IN_CHANGE | IN_UPDATE; |
1271 | } else { |
1272 | error = ffs_balloc(vp, ffs_lblktosize(fs, (off_t)lbn), |
1273 | fs->fs_bsize, l->l_cred, B_METAONLY, &ibp); |
1274 | if (error) |
1275 | break; |
1276 | blkno = idb_get(ip, ibp->b_data, |
1277 | (lbn - UFS_NDADDR) % FFS_NINDIR(fs)); |
1278 | } |
1279 | /* |
1280 | * If we are expunging a snapshot vnode and we |
1281 | * find a block marked BLK_NOCOPY, then it is |
1282 | * one that has been allocated to this snapshot after |
1283 | * we took our current snapshot and can be ignored. |
1284 | */ |
1285 | if (expungetype == BLK_SNAP && blkno == BLK_NOCOPY) { |
1286 | if (lbn >= UFS_NDADDR) |
1287 | brelse(ibp, 0); |
1288 | } else { |
1289 | if (blkno != 0) |
1290 | panic("snapacct: bad block" ); |
1291 | if (lbn < UFS_NDADDR) |
1292 | db_assign(ip, lbn, expungetype); |
1293 | else { |
1294 | idb_assign(ip, ibp->b_data, |
1295 | (lbn - UFS_NDADDR) % FFS_NINDIR(fs), expungetype); |
1296 | bdwrite(ibp); |
1297 | } |
1298 | } |
1299 | if (wbreak > 0 && (++n % wbreak) == 0) { |
1300 | UFS_WAPBL_END(mp); |
1301 | error = UFS_WAPBL_BEGIN(mp); |
1302 | if (error) |
1303 | return error; |
1304 | } |
1305 | } |
1306 | UFS_WAPBL_END(mp); |
1307 | return error; |
1308 | } |
1309 | |
1310 | /* |
1311 | * Account for a set of blocks allocated in a snapshot inode. |
1312 | */ |
1313 | static int |
1314 | mapacct(struct vnode *vp, void *bap, int oldblkp, int lastblkp, |
1315 | struct fs *fs, daddr_t lblkno, int expungetype) |
1316 | { |
1317 | daddr_t blkno; |
1318 | struct inode *ip; |
1319 | struct mount *mp = vp->v_mount; |
1320 | ino_t inum; |
1321 | int acctit, error, n; |
1322 | const int wbreak = blocks_in_journal(VFSTOUFS(mp)->um_fs)/8; |
1323 | |
1324 | error = UFS_WAPBL_BEGIN(mp); |
1325 | if (error) |
1326 | return error; |
1327 | ip = VTOI(vp); |
1328 | inum = ip->i_number; |
1329 | if (lblkno == -1) |
1330 | acctit = 0; |
1331 | else |
1332 | acctit = 1; |
1333 | for ( n = 0; oldblkp < lastblkp; oldblkp++, lblkno++) { |
1334 | blkno = idb_get(ip, bap, oldblkp); |
1335 | if (blkno == 0 || blkno == BLK_NOCOPY) |
1336 | continue; |
1337 | if (acctit && expungetype == BLK_SNAP && blkno != BLK_SNAP) |
1338 | *ip->i_snapblklist++ = lblkno; |
1339 | if (blkno == BLK_SNAP) |
1340 | blkno = ffs_blkstofrags(fs, lblkno); |
1341 | ffs_blkfree_snap(fs, vp, blkno, fs->fs_bsize, inum); |
1342 | if (wbreak > 0 && (++n % wbreak) == 0) { |
1343 | UFS_WAPBL_END(mp); |
1344 | error = UFS_WAPBL_BEGIN(mp); |
1345 | if (error) |
1346 | return error; |
1347 | } |
1348 | } |
1349 | UFS_WAPBL_END(mp); |
1350 | return (0); |
1351 | } |
1352 | |
1353 | /* |
1354 | * Number of blocks that fit into the journal or zero if not logging. |
1355 | */ |
1356 | static int |
1357 | blocks_in_journal(struct fs *fs) |
1358 | { |
1359 | off_t bpj; |
1360 | |
1361 | if ((fs->fs_flags & FS_DOWAPBL) == 0) |
1362 | return 0; |
1363 | bpj = 1; |
1364 | if (fs->fs_journal_version == UFS_WAPBL_VERSION) { |
1365 | switch (fs->fs_journal_location) { |
1366 | case UFS_WAPBL_JOURNALLOC_END_PARTITION: |
1367 | bpj = (off_t)fs->fs_journallocs[UFS_WAPBL_EPART_BLKSZ]* |
1368 | fs->fs_journallocs[UFS_WAPBL_EPART_COUNT]; |
1369 | break; |
1370 | case UFS_WAPBL_JOURNALLOC_IN_FILESYSTEM: |
1371 | bpj = (off_t)fs->fs_journallocs[UFS_WAPBL_INFS_BLKSZ]* |
1372 | fs->fs_journallocs[UFS_WAPBL_INFS_COUNT]; |
1373 | break; |
1374 | } |
1375 | } |
1376 | bpj /= fs->fs_bsize; |
1377 | return (bpj > 0 ? bpj : 1); |
1378 | } |
1379 | #endif /* defined(FFS_NO_SNAPSHOT) */ |
1380 | |
1381 | /* |
1382 | * Decrement extra reference on snapshot when last name is removed. |
1383 | * It will not be freed until the last open reference goes away. |
1384 | */ |
1385 | void |
1386 | ffs_snapgone(struct vnode *vp) |
1387 | { |
1388 | struct inode *xp, *ip = VTOI(vp); |
1389 | struct mount *mp = spec_node_getmountedfs(ip->i_devvp); |
1390 | struct fs *fs; |
1391 | struct snap_info *si; |
1392 | int snaploc; |
1393 | |
1394 | si = VFSTOUFS(mp)->um_snapinfo; |
1395 | |
1396 | /* |
1397 | * Find snapshot in incore list. |
1398 | */ |
1399 | mutex_enter(&si->si_lock); |
1400 | TAILQ_FOREACH(xp, &si->si_snapshots, i_nextsnap) |
1401 | if (xp == ip) |
1402 | break; |
1403 | mutex_exit(&si->si_lock); |
1404 | if (xp != NULL) |
1405 | vrele(ITOV(ip)); |
1406 | #ifdef DEBUG |
1407 | else if (snapdebug) |
1408 | printf("ffs_snapgone: lost snapshot vnode %llu\n" , |
1409 | (unsigned long long)ip->i_number); |
1410 | #endif |
1411 | /* |
1412 | * Delete snapshot inode from superblock. Keep list dense. |
1413 | */ |
1414 | mutex_enter(&si->si_lock); |
1415 | fs = ip->i_fs; |
1416 | for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++) |
1417 | if (fs->fs_snapinum[snaploc] == ip->i_number) |
1418 | break; |
1419 | if (snaploc < FSMAXSNAP) { |
1420 | for (snaploc++; snaploc < FSMAXSNAP; snaploc++) { |
1421 | if (fs->fs_snapinum[snaploc] == 0) |
1422 | break; |
1423 | fs->fs_snapinum[snaploc - 1] = fs->fs_snapinum[snaploc]; |
1424 | } |
1425 | fs->fs_snapinum[snaploc - 1] = 0; |
1426 | } |
1427 | si->si_gen++; |
1428 | mutex_exit(&si->si_lock); |
1429 | } |
1430 | |
1431 | /* |
1432 | * Prepare a snapshot file for being removed. |
1433 | */ |
1434 | void |
1435 | ffs_snapremove(struct vnode *vp) |
1436 | { |
1437 | struct inode *ip = VTOI(vp), *xp; |
1438 | struct vnode *devvp = ip->i_devvp; |
1439 | struct fs *fs = ip->i_fs; |
1440 | struct mount *mp = spec_node_getmountedfs(devvp); |
1441 | struct buf *ibp; |
1442 | struct snap_info *si; |
1443 | struct lwp *l = curlwp; |
1444 | daddr_t numblks, blkno, dblk; |
1445 | int error, loc, last; |
1446 | |
1447 | si = VFSTOUFS(mp)->um_snapinfo; |
1448 | /* |
1449 | * If active, delete from incore list (this snapshot may |
1450 | * already have been in the process of being deleted, so |
1451 | * would not have been active). |
1452 | * |
1453 | * Clear copy-on-write flag if last snapshot. |
1454 | */ |
1455 | mutex_enter(&si->si_snaplock); |
1456 | mutex_enter(&si->si_lock); |
1457 | if (is_active_snapshot(si, ip)) { |
1458 | TAILQ_REMOVE(&si->si_snapshots, ip, i_nextsnap); |
1459 | if (TAILQ_FIRST(&si->si_snapshots) != 0) { |
1460 | /* Roll back the list of preallocated blocks. */ |
1461 | xp = TAILQ_LAST(&si->si_snapshots, inodelst); |
1462 | si->si_snapblklist = xp->i_snapblklist; |
1463 | si->si_gen++; |
1464 | mutex_exit(&si->si_lock); |
1465 | mutex_exit(&si->si_snaplock); |
1466 | } else { |
1467 | si->si_snapblklist = 0; |
1468 | si->si_gen++; |
1469 | mutex_exit(&si->si_lock); |
1470 | mutex_exit(&si->si_snaplock); |
1471 | fscow_disestablish(mp, ffs_copyonwrite, devvp); |
1472 | } |
1473 | if (ip->i_snapblklist != NULL) { |
1474 | free(ip->i_snapblklist, M_UFSMNT); |
1475 | ip->i_snapblklist = NULL; |
1476 | } |
1477 | } else { |
1478 | mutex_exit(&si->si_lock); |
1479 | mutex_exit(&si->si_snaplock); |
1480 | } |
1481 | /* |
1482 | * Clear all BLK_NOCOPY fields. Pass any block claims to other |
1483 | * snapshots that want them (see ffs_snapblkfree below). |
1484 | */ |
1485 | for (blkno = 1; blkno < UFS_NDADDR; blkno++) { |
1486 | dblk = db_get(ip, blkno); |
1487 | if (dblk == BLK_NOCOPY || dblk == BLK_SNAP) |
1488 | db_assign(ip, blkno, 0); |
1489 | else if ((dblk == ffs_blkstofrags(fs, blkno) && |
1490 | ffs_snapblkfree(fs, ip->i_devvp, dblk, fs->fs_bsize, |
1491 | ip->i_number))) { |
1492 | DIP_ADD(ip, blocks, -btodb(fs->fs_bsize)); |
1493 | db_assign(ip, blkno, 0); |
1494 | } |
1495 | } |
1496 | numblks = howmany(ip->i_size, fs->fs_bsize); |
1497 | for (blkno = UFS_NDADDR; blkno < numblks; blkno += FFS_NINDIR(fs)) { |
1498 | error = ffs_balloc(vp, ffs_lblktosize(fs, (off_t)blkno), |
1499 | fs->fs_bsize, l->l_cred, B_METAONLY, &ibp); |
1500 | if (error) |
1501 | continue; |
1502 | if (fs->fs_size - blkno > FFS_NINDIR(fs)) |
1503 | last = FFS_NINDIR(fs); |
1504 | else |
1505 | last = fs->fs_size - blkno; |
1506 | for (loc = 0; loc < last; loc++) { |
1507 | dblk = idb_get(ip, ibp->b_data, loc); |
1508 | if (dblk == BLK_NOCOPY || dblk == BLK_SNAP) |
1509 | idb_assign(ip, ibp->b_data, loc, 0); |
1510 | else if (dblk == ffs_blkstofrags(fs, blkno) && |
1511 | ffs_snapblkfree(fs, ip->i_devvp, dblk, |
1512 | fs->fs_bsize, ip->i_number)) { |
1513 | DIP_ADD(ip, blocks, -btodb(fs->fs_bsize)); |
1514 | idb_assign(ip, ibp->b_data, loc, 0); |
1515 | } |
1516 | } |
1517 | bawrite(ibp); |
1518 | UFS_WAPBL_END(mp); |
1519 | error = UFS_WAPBL_BEGIN(mp); |
1520 | KASSERT(error == 0); |
1521 | } |
1522 | /* |
1523 | * Clear snapshot flag and drop reference. |
1524 | */ |
1525 | ip->i_flags &= ~(SF_SNAPSHOT | SF_SNAPINVAL); |
1526 | DIP_ASSIGN(ip, flags, ip->i_flags); |
1527 | ip->i_flag |= IN_CHANGE | IN_UPDATE; |
1528 | #if defined(QUOTA) || defined(QUOTA2) |
1529 | chkdq(ip, DIP(ip, blocks), l->l_cred, FORCE); |
1530 | chkiq(ip, 1, l->l_cred, FORCE); |
1531 | #endif |
1532 | } |
1533 | |
1534 | /* |
1535 | * Notification that a block is being freed. Return zero if the free |
1536 | * should be allowed to proceed. Return non-zero if the snapshot file |
1537 | * wants to claim the block. The block will be claimed if it is an |
1538 | * uncopied part of one of the snapshots. It will be freed if it is |
1539 | * either a BLK_NOCOPY or has already been copied in all of the snapshots. |
1540 | * If a fragment is being freed, then all snapshots that care about |
1541 | * it must make a copy since a snapshot file can only claim full sized |
1542 | * blocks. Note that if more than one snapshot file maps the block, |
1543 | * we can pick one at random to claim it. Since none of the snapshots |
1544 | * can change, we are assurred that they will all see the same unmodified |
1545 | * image. When deleting a snapshot file (see ffs_snapremove above), we |
1546 | * must push any of these claimed blocks to one of the other snapshots |
1547 | * that maps it. These claimed blocks are easily identified as they will |
1548 | * have a block number equal to their logical block number within the |
1549 | * snapshot. A copied block can never have this property because they |
1550 | * must always have been allocated from a BLK_NOCOPY location. |
1551 | */ |
1552 | int |
1553 | ffs_snapblkfree(struct fs *fs, struct vnode *devvp, daddr_t bno, |
1554 | long size, ino_t inum) |
1555 | { |
1556 | struct mount *mp = spec_node_getmountedfs(devvp); |
1557 | struct buf *ibp; |
1558 | struct inode *ip; |
1559 | struct vnode *vp = NULL; |
1560 | struct snap_info *si; |
1561 | void *saved_data = NULL; |
1562 | daddr_t lbn; |
1563 | daddr_t blkno; |
1564 | uint32_t gen; |
1565 | int indiroff = 0, error = 0, claimedblk = 0; |
1566 | |
1567 | si = VFSTOUFS(mp)->um_snapinfo; |
1568 | lbn = ffs_fragstoblks(fs, bno); |
1569 | mutex_enter(&si->si_snaplock); |
1570 | mutex_enter(&si->si_lock); |
1571 | si->si_owner = curlwp; |
1572 | |
1573 | retry: |
1574 | gen = si->si_gen; |
1575 | TAILQ_FOREACH(ip, &si->si_snapshots, i_nextsnap) { |
1576 | vp = ITOV(ip); |
1577 | /* |
1578 | * Lookup block being written. |
1579 | */ |
1580 | if (lbn < UFS_NDADDR) { |
1581 | blkno = db_get(ip, lbn); |
1582 | } else { |
1583 | mutex_exit(&si->si_lock); |
1584 | error = ffs_balloc(vp, ffs_lblktosize(fs, (off_t)lbn), |
1585 | fs->fs_bsize, FSCRED, B_METAONLY, &ibp); |
1586 | if (error) { |
1587 | mutex_enter(&si->si_lock); |
1588 | break; |
1589 | } |
1590 | indiroff = (lbn - UFS_NDADDR) % FFS_NINDIR(fs); |
1591 | blkno = idb_get(ip, ibp->b_data, indiroff); |
1592 | mutex_enter(&si->si_lock); |
1593 | if (gen != si->si_gen) { |
1594 | brelse(ibp, 0); |
1595 | goto retry; |
1596 | } |
1597 | } |
1598 | /* |
1599 | * Check to see if block needs to be copied. |
1600 | */ |
1601 | if (blkno == 0) { |
1602 | /* |
1603 | * A block that we map is being freed. If it has not |
1604 | * been claimed yet, we will claim or copy it (below). |
1605 | */ |
1606 | claimedblk = 1; |
1607 | } else if (blkno == BLK_SNAP) { |
1608 | /* |
1609 | * No previous snapshot claimed the block, |
1610 | * so it will be freed and become a BLK_NOCOPY |
1611 | * (don't care) for us. |
1612 | */ |
1613 | if (claimedblk) |
1614 | panic("snapblkfree: inconsistent block type" ); |
1615 | if (lbn < UFS_NDADDR) { |
1616 | db_assign(ip, lbn, BLK_NOCOPY); |
1617 | ip->i_flag |= IN_CHANGE | IN_UPDATE; |
1618 | } else { |
1619 | idb_assign(ip, ibp->b_data, indiroff, |
1620 | BLK_NOCOPY); |
1621 | mutex_exit(&si->si_lock); |
1622 | if (ip->i_nlink > 0) |
1623 | bwrite(ibp); |
1624 | else |
1625 | bdwrite(ibp); |
1626 | mutex_enter(&si->si_lock); |
1627 | if (gen != si->si_gen) |
1628 | goto retry; |
1629 | } |
1630 | continue; |
1631 | } else /* BLK_NOCOPY or default */ { |
1632 | /* |
1633 | * If the snapshot has already copied the block |
1634 | * (default), or does not care about the block, |
1635 | * it is not needed. |
1636 | */ |
1637 | if (lbn >= UFS_NDADDR) |
1638 | brelse(ibp, 0); |
1639 | continue; |
1640 | } |
1641 | /* |
1642 | * If this is a full size block, we will just grab it |
1643 | * and assign it to the snapshot inode. Otherwise we |
1644 | * will proceed to copy it. See explanation for this |
1645 | * routine as to why only a single snapshot needs to |
1646 | * claim this block. |
1647 | */ |
1648 | if (size == fs->fs_bsize) { |
1649 | #ifdef DEBUG |
1650 | if (snapdebug) |
1651 | printf("%s %llu lbn %" PRId64 |
1652 | "from inum %llu\n" , |
1653 | "Grabonremove: snapino" , |
1654 | (unsigned long long)ip->i_number, |
1655 | lbn, (unsigned long long)inum); |
1656 | #endif |
1657 | mutex_exit(&si->si_lock); |
1658 | if (lbn < UFS_NDADDR) { |
1659 | db_assign(ip, lbn, bno); |
1660 | } else { |
1661 | idb_assign(ip, ibp->b_data, indiroff, bno); |
1662 | if (ip->i_nlink > 0) |
1663 | bwrite(ibp); |
1664 | else |
1665 | bdwrite(ibp); |
1666 | } |
1667 | DIP_ADD(ip, blocks, btodb(size)); |
1668 | ip->i_flag |= IN_CHANGE | IN_UPDATE; |
1669 | if (ip->i_nlink > 0 && mp->mnt_wapbl) |
1670 | error = syncsnap(vp); |
1671 | else |
1672 | error = 0; |
1673 | mutex_enter(&si->si_lock); |
1674 | si->si_owner = NULL; |
1675 | mutex_exit(&si->si_lock); |
1676 | mutex_exit(&si->si_snaplock); |
1677 | return (error == 0); |
1678 | } |
1679 | if (lbn >= UFS_NDADDR) |
1680 | brelse(ibp, 0); |
1681 | #ifdef DEBUG |
1682 | if (snapdebug) |
1683 | printf("%s%llu lbn %" PRId64 " %s %llu size %ld\n" , |
1684 | "Copyonremove: snapino " , |
1685 | (unsigned long long)ip->i_number, |
1686 | lbn, "for inum" , (unsigned long long)inum, size); |
1687 | #endif |
1688 | /* |
1689 | * If we have already read the old block contents, then |
1690 | * simply copy them to the new block. Note that we need |
1691 | * to synchronously write snapshots that have not been |
1692 | * unlinked, and hence will be visible after a crash, |
1693 | * to ensure their integrity. |
1694 | */ |
1695 | mutex_exit(&si->si_lock); |
1696 | if (saved_data == NULL) { |
1697 | saved_data = malloc(fs->fs_bsize, M_UFSMNT, M_WAITOK); |
1698 | error = rwfsblk(vp, B_READ, saved_data, lbn); |
1699 | if (error) { |
1700 | free(saved_data, M_UFSMNT); |
1701 | saved_data = NULL; |
1702 | mutex_enter(&si->si_lock); |
1703 | break; |
1704 | } |
1705 | } |
1706 | error = wrsnapblk(vp, saved_data, lbn); |
1707 | if (error == 0 && ip->i_nlink > 0 && mp->mnt_wapbl) |
1708 | error = syncsnap(vp); |
1709 | mutex_enter(&si->si_lock); |
1710 | if (error) |
1711 | break; |
1712 | if (gen != si->si_gen) |
1713 | goto retry; |
1714 | } |
1715 | si->si_owner = NULL; |
1716 | mutex_exit(&si->si_lock); |
1717 | mutex_exit(&si->si_snaplock); |
1718 | if (saved_data) |
1719 | free(saved_data, M_UFSMNT); |
1720 | /* |
1721 | * If we have been unable to allocate a block in which to do |
1722 | * the copy, then return non-zero so that the fragment will |
1723 | * not be freed. Although space will be lost, the snapshot |
1724 | * will stay consistent. |
1725 | */ |
1726 | return (error); |
1727 | } |
1728 | |
1729 | /* |
1730 | * Associate snapshot files when mounting. |
1731 | */ |
1732 | void |
1733 | ffs_snapshot_mount(struct mount *mp) |
1734 | { |
1735 | struct vnode *devvp = VFSTOUFS(mp)->um_devvp; |
1736 | struct fs *fs = VFSTOUFS(mp)->um_fs; |
1737 | struct lwp *l = curlwp; |
1738 | struct vnode *vp; |
1739 | struct inode *ip, *xp; |
1740 | struct snap_info *si; |
1741 | daddr_t snaplistsize, *snapblklist; |
1742 | int i, error, ns __unused, snaploc, loc; |
1743 | |
1744 | /* |
1745 | * No persistent snapshots on apple ufs file systems. |
1746 | */ |
1747 | if (UFS_MPISAPPLEUFS(VFSTOUFS(mp))) |
1748 | return; |
1749 | |
1750 | si = VFSTOUFS(mp)->um_snapinfo; |
1751 | ns = UFS_FSNEEDSWAP(fs); |
1752 | /* |
1753 | * XXX The following needs to be set before ffs_truncate or |
1754 | * VOP_READ can be called. |
1755 | */ |
1756 | mp->mnt_stat.f_iosize = fs->fs_bsize; |
1757 | /* |
1758 | * Process each snapshot listed in the superblock. |
1759 | */ |
1760 | vp = NULL; |
1761 | mutex_enter(&si->si_lock); |
1762 | for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++) { |
1763 | if (fs->fs_snapinum[snaploc] == 0) |
1764 | break; |
1765 | if ((error = VFS_VGET(mp, fs->fs_snapinum[snaploc], |
1766 | &vp)) != 0) { |
1767 | printf("ffs_snapshot_mount: vget failed %d\n" , error); |
1768 | continue; |
1769 | } |
1770 | ip = VTOI(vp); |
1771 | if ((ip->i_flags & (SF_SNAPSHOT | SF_SNAPINVAL)) != |
1772 | SF_SNAPSHOT) { |
1773 | printf("ffs_snapshot_mount: non-snapshot inode %d\n" , |
1774 | fs->fs_snapinum[snaploc]); |
1775 | vput(vp); |
1776 | vp = NULL; |
1777 | for (loc = snaploc + 1; loc < FSMAXSNAP; loc++) { |
1778 | if (fs->fs_snapinum[loc] == 0) |
1779 | break; |
1780 | fs->fs_snapinum[loc - 1] = fs->fs_snapinum[loc]; |
1781 | } |
1782 | fs->fs_snapinum[loc - 1] = 0; |
1783 | snaploc--; |
1784 | continue; |
1785 | } |
1786 | |
1787 | /* |
1788 | * Read the block hints list. Use an empty list on |
1789 | * read errors. |
1790 | */ |
1791 | error = vn_rdwr(UIO_READ, vp, |
1792 | (void *)&snaplistsize, sizeof(snaplistsize), |
1793 | ffs_lblktosize(fs, howmany(fs->fs_size, fs->fs_frag)), |
1794 | UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT|IO_ALTSEMANTICS, |
1795 | l->l_cred, NULL, NULL); |
1796 | if (error) { |
1797 | printf("ffs_snapshot_mount: read_1 failed %d\n" , error); |
1798 | snaplistsize = 1; |
1799 | } else |
1800 | snaplistsize = ufs_rw64(snaplistsize, ns); |
1801 | snapblklist = malloc( |
1802 | snaplistsize * sizeof(daddr_t), M_UFSMNT, M_WAITOK); |
1803 | if (error) |
1804 | snapblklist[0] = 1; |
1805 | else { |
1806 | error = vn_rdwr(UIO_READ, vp, (void *)snapblklist, |
1807 | snaplistsize * sizeof(daddr_t), |
1808 | ffs_lblktosize(fs, howmany(fs->fs_size, fs->fs_frag)), |
1809 | UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT|IO_ALTSEMANTICS, |
1810 | l->l_cred, NULL, NULL); |
1811 | for (i = 0; i < snaplistsize; i++) |
1812 | snapblklist[i] = ufs_rw64(snapblklist[i], ns); |
1813 | if (error) { |
1814 | printf("ffs_snapshot_mount: read_2 failed %d\n" , |
1815 | error); |
1816 | snapblklist[0] = 1; |
1817 | } |
1818 | } |
1819 | ip->i_snapblklist = &snapblklist[0]; |
1820 | |
1821 | /* |
1822 | * Link it onto the active snapshot list. |
1823 | */ |
1824 | if (is_active_snapshot(si, ip)) |
1825 | panic("ffs_snapshot_mount: %" PRIu64" already on list" , |
1826 | ip->i_number); |
1827 | else |
1828 | TAILQ_INSERT_TAIL(&si->si_snapshots, ip, i_nextsnap); |
1829 | vp->v_vflag |= VV_SYSTEM; |
1830 | VOP_UNLOCK(vp); |
1831 | } |
1832 | /* |
1833 | * No usable snapshots found. |
1834 | */ |
1835 | if (vp == NULL) { |
1836 | mutex_exit(&si->si_lock); |
1837 | return; |
1838 | } |
1839 | /* |
1840 | * Attach the block hints list. We always want to |
1841 | * use the list from the newest snapshot. |
1842 | */ |
1843 | xp = TAILQ_LAST(&si->si_snapshots, inodelst); |
1844 | si->si_snapblklist = xp->i_snapblklist; |
1845 | fscow_establish(mp, ffs_copyonwrite, devvp); |
1846 | si->si_gen++; |
1847 | mutex_exit(&si->si_lock); |
1848 | } |
1849 | |
1850 | /* |
1851 | * Disassociate snapshot files when unmounting. |
1852 | */ |
1853 | void |
1854 | ffs_snapshot_unmount(struct mount *mp) |
1855 | { |
1856 | struct vnode *devvp = VFSTOUFS(mp)->um_devvp; |
1857 | struct inode *xp; |
1858 | struct vnode *vp = NULL; |
1859 | struct snap_info *si; |
1860 | |
1861 | si = VFSTOUFS(mp)->um_snapinfo; |
1862 | mutex_enter(&si->si_lock); |
1863 | while ((xp = TAILQ_FIRST(&si->si_snapshots)) != 0) { |
1864 | vp = ITOV(xp); |
1865 | TAILQ_REMOVE(&si->si_snapshots, xp, i_nextsnap); |
1866 | if (xp->i_snapblklist == si->si_snapblklist) |
1867 | si->si_snapblklist = NULL; |
1868 | free(xp->i_snapblklist, M_UFSMNT); |
1869 | if (xp->i_nlink > 0) { |
1870 | si->si_gen++; |
1871 | mutex_exit(&si->si_lock); |
1872 | vrele(vp); |
1873 | mutex_enter(&si->si_lock); |
1874 | } |
1875 | } |
1876 | si->si_gen++; |
1877 | mutex_exit(&si->si_lock); |
1878 | if (vp) |
1879 | fscow_disestablish(mp, ffs_copyonwrite, devvp); |
1880 | } |
1881 | |
1882 | /* |
1883 | * Check for need to copy block that is about to be written, |
1884 | * copying the block if necessary. |
1885 | */ |
1886 | static int |
1887 | ffs_copyonwrite(void *v, struct buf *bp, bool data_valid) |
1888 | { |
1889 | struct fs *fs; |
1890 | struct inode *ip; |
1891 | struct vnode *devvp = v, *vp = NULL; |
1892 | struct mount *mp = spec_node_getmountedfs(devvp); |
1893 | struct snap_info *si; |
1894 | void *saved_data = NULL; |
1895 | daddr_t lbn, blkno, *snapblklist; |
1896 | uint32_t gen; |
1897 | int lower, upper, mid, snapshot_locked = 0, error = 0; |
1898 | |
1899 | /* |
1900 | * Check for valid snapshots. |
1901 | */ |
1902 | si = VFSTOUFS(mp)->um_snapinfo; |
1903 | mutex_enter(&si->si_lock); |
1904 | ip = TAILQ_FIRST(&si->si_snapshots); |
1905 | if (ip == NULL) { |
1906 | mutex_exit(&si->si_lock); |
1907 | return 0; |
1908 | } |
1909 | /* |
1910 | * First check to see if it is after the file system, |
1911 | * in the journal or in the preallocated list. |
1912 | * By doing these checks we avoid several potential deadlocks. |
1913 | */ |
1914 | fs = ip->i_fs; |
1915 | lbn = ffs_fragstoblks(fs, FFS_DBTOFSB(fs, bp->b_blkno)); |
1916 | if (bp->b_blkno >= FFS_FSBTODB(fs, fs->fs_size)) { |
1917 | mutex_exit(&si->si_lock); |
1918 | return 0; |
1919 | } |
1920 | if ((fs->fs_flags & FS_DOWAPBL) && |
1921 | fs->fs_journal_location == UFS_WAPBL_JOURNALLOC_IN_FILESYSTEM) { |
1922 | off_t blk_off, log_start, log_end; |
1923 | |
1924 | log_start = (off_t)fs->fs_journallocs[UFS_WAPBL_INFS_ADDR] * |
1925 | fs->fs_journallocs[UFS_WAPBL_INFS_BLKSZ]; |
1926 | log_end = log_start + fs->fs_journallocs[UFS_WAPBL_INFS_COUNT] * |
1927 | fs->fs_journallocs[UFS_WAPBL_INFS_BLKSZ]; |
1928 | blk_off = dbtob(bp->b_blkno); |
1929 | if (blk_off >= log_start && blk_off < log_end) { |
1930 | mutex_exit(&si->si_lock); |
1931 | return 0; |
1932 | } |
1933 | } |
1934 | snapblklist = si->si_snapblklist; |
1935 | upper = (snapblklist != NULL ? snapblklist[0] - 1 : 0); |
1936 | lower = 1; |
1937 | while (lower <= upper) { |
1938 | mid = (lower + upper) / 2; |
1939 | if (snapblklist[mid] == lbn) |
1940 | break; |
1941 | if (snapblklist[mid] < lbn) |
1942 | lower = mid + 1; |
1943 | else |
1944 | upper = mid - 1; |
1945 | } |
1946 | if (lower <= upper) { |
1947 | mutex_exit(&si->si_lock); |
1948 | return 0; |
1949 | } |
1950 | /* |
1951 | * Not in the precomputed list, so check the snapshots. |
1952 | */ |
1953 | if (si->si_owner != curlwp) { |
1954 | if (!mutex_tryenter(&si->si_snaplock)) { |
1955 | mutex_exit(&si->si_lock); |
1956 | mutex_enter(&si->si_snaplock); |
1957 | mutex_enter(&si->si_lock); |
1958 | } |
1959 | si->si_owner = curlwp; |
1960 | snapshot_locked = 1; |
1961 | } |
1962 | if (data_valid && bp->b_bcount == fs->fs_bsize) |
1963 | saved_data = bp->b_data; |
1964 | retry: |
1965 | gen = si->si_gen; |
1966 | TAILQ_FOREACH(ip, &si->si_snapshots, i_nextsnap) { |
1967 | vp = ITOV(ip); |
1968 | /* |
1969 | * We ensure that everything of our own that needs to be |
1970 | * copied will be done at the time that ffs_snapshot is |
1971 | * called. Thus we can skip the check here which can |
1972 | * deadlock in doing the lookup in ffs_balloc. |
1973 | */ |
1974 | if (bp->b_vp == vp) |
1975 | continue; |
1976 | /* |
1977 | * Check to see if block needs to be copied. |
1978 | */ |
1979 | if (lbn < UFS_NDADDR) { |
1980 | blkno = db_get(ip, lbn); |
1981 | } else { |
1982 | mutex_exit(&si->si_lock); |
1983 | blkno = 0; /* XXX: GCC */ |
1984 | if ((error = snapblkaddr(vp, lbn, &blkno)) != 0) { |
1985 | mutex_enter(&si->si_lock); |
1986 | break; |
1987 | } |
1988 | mutex_enter(&si->si_lock); |
1989 | if (gen != si->si_gen) |
1990 | goto retry; |
1991 | } |
1992 | #ifdef DIAGNOSTIC |
1993 | if (blkno == BLK_SNAP && bp->b_lblkno >= 0) |
1994 | panic("ffs_copyonwrite: bad copy block" ); |
1995 | #endif |
1996 | if (blkno != 0) |
1997 | continue; |
1998 | |
1999 | if (curlwp == uvm.pagedaemon_lwp) { |
2000 | error = ENOMEM; |
2001 | break; |
2002 | } |
2003 | /* Only one level of recursion allowed. */ |
2004 | KASSERT(snapshot_locked); |
2005 | /* |
2006 | * Allocate the block into which to do the copy. Since |
2007 | * multiple processes may all try to copy the same block, |
2008 | * we have to recheck our need to do a copy if we sleep |
2009 | * waiting for the lock. |
2010 | * |
2011 | * Because all snapshots on a filesystem share a single |
2012 | * lock, we ensure that we will never be in competition |
2013 | * with another process to allocate a block. |
2014 | */ |
2015 | #ifdef DEBUG |
2016 | if (snapdebug) { |
2017 | printf("Copyonwrite: snapino %llu lbn %" PRId64 " for " , |
2018 | (unsigned long long)ip->i_number, lbn); |
2019 | if (bp->b_vp == devvp) |
2020 | printf("fs metadata" ); |
2021 | else |
2022 | printf("inum %llu" , (unsigned long long) |
2023 | VTOI(bp->b_vp)->i_number); |
2024 | printf(" lblkno %" PRId64 "\n" , bp->b_lblkno); |
2025 | } |
2026 | #endif |
2027 | /* |
2028 | * If we have already read the old block contents, then |
2029 | * simply copy them to the new block. Note that we need |
2030 | * to synchronously write snapshots that have not been |
2031 | * unlinked, and hence will be visible after a crash, |
2032 | * to ensure their integrity. |
2033 | */ |
2034 | mutex_exit(&si->si_lock); |
2035 | if (saved_data == NULL) { |
2036 | saved_data = malloc(fs->fs_bsize, M_UFSMNT, M_WAITOK); |
2037 | error = rwfsblk(vp, B_READ, saved_data, lbn); |
2038 | if (error) { |
2039 | free(saved_data, M_UFSMNT); |
2040 | saved_data = NULL; |
2041 | mutex_enter(&si->si_lock); |
2042 | break; |
2043 | } |
2044 | } |
2045 | error = wrsnapblk(vp, saved_data, lbn); |
2046 | if (error == 0 && ip->i_nlink > 0 && mp->mnt_wapbl) |
2047 | error = syncsnap(vp); |
2048 | mutex_enter(&si->si_lock); |
2049 | if (error) |
2050 | break; |
2051 | if (gen != si->si_gen) |
2052 | goto retry; |
2053 | } |
2054 | /* |
2055 | * Note that we need to synchronously write snapshots that |
2056 | * have not been unlinked, and hence will be visible after |
2057 | * a crash, to ensure their integrity. |
2058 | */ |
2059 | if (snapshot_locked) { |
2060 | si->si_owner = NULL; |
2061 | mutex_exit(&si->si_lock); |
2062 | mutex_exit(&si->si_snaplock); |
2063 | } else |
2064 | mutex_exit(&si->si_lock); |
2065 | if (saved_data && saved_data != bp->b_data) |
2066 | free(saved_data, M_UFSMNT); |
2067 | return error; |
2068 | } |
2069 | |
2070 | /* |
2071 | * Read from a snapshot. |
2072 | */ |
2073 | int |
2074 | ffs_snapshot_read(struct vnode *vp, struct uio *uio, int ioflag) |
2075 | { |
2076 | struct inode *ip = VTOI(vp); |
2077 | struct fs *fs = ip->i_fs; |
2078 | struct snap_info *si = VFSTOUFS(vp->v_mount)->um_snapinfo; |
2079 | struct buf *bp; |
2080 | daddr_t lbn, nextlbn; |
2081 | off_t fsbytes, bytesinfile; |
2082 | long size, xfersize, blkoffset; |
2083 | int error; |
2084 | |
2085 | fstrans_start(vp->v_mount, FSTRANS_SHARED); |
2086 | mutex_enter(&si->si_snaplock); |
2087 | |
2088 | if (ioflag & IO_ALTSEMANTICS) |
2089 | fsbytes = ip->i_size; |
2090 | else |
2091 | fsbytes = ffs_lfragtosize(fs, fs->fs_size); |
2092 | for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { |
2093 | bytesinfile = fsbytes - uio->uio_offset; |
2094 | if (bytesinfile <= 0) |
2095 | break; |
2096 | lbn = ffs_lblkno(fs, uio->uio_offset); |
2097 | nextlbn = lbn + 1; |
2098 | size = fs->fs_bsize; |
2099 | blkoffset = ffs_blkoff(fs, uio->uio_offset); |
2100 | xfersize = MIN(MIN(fs->fs_bsize - blkoffset, uio->uio_resid), |
2101 | bytesinfile); |
2102 | |
2103 | if (ffs_lblktosize(fs, nextlbn + 1) >= fsbytes) { |
2104 | if (ffs_lblktosize(fs, lbn) + size > fsbytes) |
2105 | size = ffs_fragroundup(fs, |
2106 | fsbytes - ffs_lblktosize(fs, lbn)); |
2107 | error = bread(vp, lbn, size, 0, &bp); |
2108 | } else { |
2109 | int nextsize = fs->fs_bsize; |
2110 | error = breadn(vp, lbn, |
2111 | size, &nextlbn, &nextsize, 1, 0, &bp); |
2112 | } |
2113 | if (error) |
2114 | break; |
2115 | |
2116 | /* |
2117 | * We should only get non-zero b_resid when an I/O error |
2118 | * has occurred, which should cause us to break above. |
2119 | * However, if the short read did not cause an error, |
2120 | * then we want to ensure that we do not uiomove bad |
2121 | * or uninitialized data. |
2122 | */ |
2123 | size -= bp->b_resid; |
2124 | if (size < blkoffset + xfersize) { |
2125 | xfersize = size - blkoffset; |
2126 | if (xfersize <= 0) |
2127 | break; |
2128 | } |
2129 | error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); |
2130 | if (error) |
2131 | break; |
2132 | brelse(bp, BC_AGE); |
2133 | } |
2134 | if (bp != NULL) |
2135 | brelse(bp, BC_AGE); |
2136 | |
2137 | mutex_exit(&si->si_snaplock); |
2138 | fstrans_done(vp->v_mount); |
2139 | return error; |
2140 | } |
2141 | |
2142 | /* |
2143 | * Lookup a snapshots data block address. |
2144 | * Simpler than UFS_BALLOC() as we know all metadata is already allocated |
2145 | * and safe even for the pagedaemon where we cannot bread(). |
2146 | */ |
2147 | static int |
2148 | snapblkaddr(struct vnode *vp, daddr_t lbn, daddr_t *res) |
2149 | { |
2150 | struct indir indirs[UFS_NIADDR + 2]; |
2151 | struct inode *ip = VTOI(vp); |
2152 | struct fs *fs = ip->i_fs; |
2153 | struct buf *bp; |
2154 | int error, num; |
2155 | |
2156 | KASSERT(lbn >= 0); |
2157 | |
2158 | if (lbn < UFS_NDADDR) { |
2159 | *res = db_get(ip, lbn); |
2160 | return 0; |
2161 | } |
2162 | if ((error = ufs_getlbns(vp, lbn, indirs, &num)) != 0) |
2163 | return error; |
2164 | if (curlwp == uvm.pagedaemon_lwp) { |
2165 | mutex_enter(&bufcache_lock); |
2166 | bp = incore(vp, indirs[num-1].in_lbn); |
2167 | if (bp && (bp->b_oflags & (BO_DONE | BO_DELWRI))) { |
2168 | *res = idb_get(ip, bp->b_data, indirs[num-1].in_off); |
2169 | error = 0; |
2170 | } else |
2171 | error = ENOMEM; |
2172 | mutex_exit(&bufcache_lock); |
2173 | return error; |
2174 | } |
2175 | error = bread(vp, indirs[num-1].in_lbn, fs->fs_bsize, 0, &bp); |
2176 | if (error == 0) { |
2177 | *res = idb_get(ip, bp->b_data, indirs[num-1].in_off); |
2178 | brelse(bp, 0); |
2179 | } |
2180 | |
2181 | return error; |
2182 | } |
2183 | |
2184 | /* |
2185 | * Read or write the specified block of the filesystem vp resides on |
2186 | * from or to the disk bypassing the buffer cache. |
2187 | */ |
2188 | static int |
2189 | rwfsblk(struct vnode *vp, int flags, void *data, daddr_t lbn) |
2190 | { |
2191 | int error; |
2192 | struct inode *ip = VTOI(vp); |
2193 | struct fs *fs = ip->i_fs; |
2194 | struct buf *nbp; |
2195 | |
2196 | nbp = getiobuf(NULL, true); |
2197 | nbp->b_flags = flags; |
2198 | nbp->b_bcount = nbp->b_bufsize = fs->fs_bsize; |
2199 | nbp->b_error = 0; |
2200 | nbp->b_data = data; |
2201 | nbp->b_blkno = nbp->b_rawblkno = FFS_FSBTODB(fs, ffs_blkstofrags(fs, lbn)); |
2202 | nbp->b_proc = NULL; |
2203 | nbp->b_dev = ip->i_devvp->v_rdev; |
2204 | SET(nbp->b_cflags, BC_BUSY); /* mark buffer busy */ |
2205 | |
2206 | bdev_strategy(nbp); |
2207 | |
2208 | error = biowait(nbp); |
2209 | |
2210 | putiobuf(nbp); |
2211 | |
2212 | return error; |
2213 | } |
2214 | |
2215 | /* |
2216 | * Write all dirty buffers to disk and invalidate them. |
2217 | */ |
2218 | static int |
2219 | syncsnap(struct vnode *vp) |
2220 | { |
2221 | int error; |
2222 | buf_t *bp; |
2223 | struct fs *fs = VTOI(vp)->i_fs; |
2224 | |
2225 | mutex_enter(&bufcache_lock); |
2226 | while ((bp = LIST_FIRST(&vp->v_dirtyblkhd))) { |
2227 | error = bbusy(bp, false, 0, NULL); |
2228 | if (error == EPASSTHROUGH) |
2229 | continue; |
2230 | else if (error != 0) { |
2231 | mutex_exit(&bufcache_lock); |
2232 | return error; |
2233 | } |
2234 | KASSERT(bp->b_bcount == fs->fs_bsize); |
2235 | mutex_exit(&bufcache_lock); |
2236 | error = rwfsblk(vp, B_WRITE, bp->b_data, |
2237 | ffs_fragstoblks(fs, FFS_DBTOFSB(fs, bp->b_blkno))); |
2238 | brelse(bp, BC_INVAL | BC_VFLUSH); |
2239 | if (error) |
2240 | return error; |
2241 | mutex_enter(&bufcache_lock); |
2242 | } |
2243 | mutex_exit(&bufcache_lock); |
2244 | |
2245 | return 0; |
2246 | } |
2247 | |
2248 | /* |
2249 | * Write the specified block to a snapshot. |
2250 | */ |
2251 | static int |
2252 | wrsnapblk(struct vnode *vp, void *data, daddr_t lbn) |
2253 | { |
2254 | struct inode *ip = VTOI(vp); |
2255 | struct fs *fs = ip->i_fs; |
2256 | struct buf *bp; |
2257 | int error; |
2258 | |
2259 | error = ffs_balloc(vp, ffs_lblktosize(fs, (off_t)lbn), fs->fs_bsize, |
2260 | FSCRED, (ip->i_nlink > 0 ? B_SYNC : 0), &bp); |
2261 | if (error) |
2262 | return error; |
2263 | memcpy(bp->b_data, data, fs->fs_bsize); |
2264 | if (ip->i_nlink > 0) |
2265 | error = bwrite(bp); |
2266 | else |
2267 | bawrite(bp); |
2268 | |
2269 | return error; |
2270 | } |
2271 | |
2272 | /* |
2273 | * Check if this inode is present on the active snapshot list. |
2274 | * Must be called with snapinfo locked. |
2275 | */ |
2276 | static inline bool |
2277 | is_active_snapshot(struct snap_info *si, struct inode *ip) |
2278 | { |
2279 | struct inode *xp; |
2280 | |
2281 | KASSERT(mutex_owned(&si->si_lock)); |
2282 | |
2283 | TAILQ_FOREACH(xp, &si->si_snapshots, i_nextsnap) |
2284 | if (xp == ip) |
2285 | return true; |
2286 | return false; |
2287 | } |
2288 | |
2289 | /* |
2290 | * Get/Put direct block from inode or buffer containing disk addresses. Take |
2291 | * care for fs type (UFS1/UFS2) and byte swapping. These functions should go |
2292 | * into a global include. |
2293 | */ |
2294 | static inline daddr_t |
2295 | db_get(struct inode *ip, int loc) |
2296 | { |
2297 | if (ip->i_ump->um_fstype == UFS1) |
2298 | return ufs_rw32(ip->i_ffs1_db[loc], UFS_IPNEEDSWAP(ip)); |
2299 | else |
2300 | return ufs_rw64(ip->i_ffs2_db[loc], UFS_IPNEEDSWAP(ip)); |
2301 | } |
2302 | |
2303 | static inline void |
2304 | db_assign(struct inode *ip, int loc, daddr_t val) |
2305 | { |
2306 | if (ip->i_ump->um_fstype == UFS1) |
2307 | ip->i_ffs1_db[loc] = ufs_rw32(val, UFS_IPNEEDSWAP(ip)); |
2308 | else |
2309 | ip->i_ffs2_db[loc] = ufs_rw64(val, UFS_IPNEEDSWAP(ip)); |
2310 | } |
2311 | |
2312 | __unused static inline daddr_t |
2313 | ib_get(struct inode *ip, int loc) |
2314 | { |
2315 | if (ip->i_ump->um_fstype == UFS1) |
2316 | return ufs_rw32(ip->i_ffs1_ib[loc], UFS_IPNEEDSWAP(ip)); |
2317 | else |
2318 | return ufs_rw64(ip->i_ffs2_ib[loc], UFS_IPNEEDSWAP(ip)); |
2319 | } |
2320 | |
2321 | static inline daddr_t |
2322 | idb_get(struct inode *ip, void *bf, int loc) |
2323 | { |
2324 | if (ip->i_ump->um_fstype == UFS1) |
2325 | return ufs_rw32(((int32_t *)(bf))[loc], UFS_IPNEEDSWAP(ip)); |
2326 | else |
2327 | return ufs_rw64(((int64_t *)(bf))[loc], UFS_IPNEEDSWAP(ip)); |
2328 | } |
2329 | |
2330 | static inline void |
2331 | idb_assign(struct inode *ip, void *bf, int loc, daddr_t val) |
2332 | { |
2333 | if (ip->i_ump->um_fstype == UFS1) |
2334 | ((int32_t *)(bf))[loc] = ufs_rw32(val, UFS_IPNEEDSWAP(ip)); |
2335 | else |
2336 | ((int64_t *)(bf))[loc] = ufs_rw64(val, UFS_IPNEEDSWAP(ip)); |
2337 | } |
2338 | |