xref: /freebsd/sys/ufs/ffs/ffs_vfsops.c (revision 9336e0699bda8a301cd2bfa37106b6ec5e32012e)
1 /*-
2  * Copyright (c) 1989, 1991, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)ffs_vfsops.c	8.31 (Berkeley) 5/20/95
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include "opt_mac.h"
36 #include "opt_quota.h"
37 #include "opt_ufs.h"
38 #include "opt_ffs.h"
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/namei.h>
43 #include <sys/priv.h>
44 #include <sys/proc.h>
45 #include <sys/kernel.h>
46 #include <sys/vnode.h>
47 #include <sys/mount.h>
48 #include <sys/bio.h>
49 #include <sys/buf.h>
50 #include <sys/conf.h>
51 #include <sys/fcntl.h>
52 #include <sys/malloc.h>
53 #include <sys/mutex.h>
54 
55 #include <security/mac/mac_framework.h>
56 
57 #include <ufs/ufs/extattr.h>
58 #include <ufs/ufs/gjournal.h>
59 #include <ufs/ufs/quota.h>
60 #include <ufs/ufs/ufsmount.h>
61 #include <ufs/ufs/inode.h>
62 #include <ufs/ufs/ufs_extern.h>
63 
64 #include <ufs/ffs/fs.h>
65 #include <ufs/ffs/ffs_extern.h>
66 
67 #include <vm/vm.h>
68 #include <vm/uma.h>
69 #include <vm/vm_page.h>
70 
71 #include <geom/geom.h>
72 #include <geom/geom_vfs.h>
73 
74 static uma_zone_t uma_inode, uma_ufs1, uma_ufs2;
75 
76 static int	ffs_reload(struct mount *, struct thread *);
77 static int	ffs_mountfs(struct vnode *, struct mount *, struct thread *);
78 static void	ffs_oldfscompat_read(struct fs *, struct ufsmount *,
79 		    ufs2_daddr_t);
80 static void	ffs_oldfscompat_write(struct fs *, struct ufsmount *);
81 static void	ffs_ifree(struct ufsmount *ump, struct inode *ip);
82 static vfs_init_t ffs_init;
83 static vfs_uninit_t ffs_uninit;
84 static vfs_extattrctl_t ffs_extattrctl;
85 static vfs_cmount_t ffs_cmount;
86 static vfs_unmount_t ffs_unmount;
87 static vfs_mount_t ffs_mount;
88 static vfs_statfs_t ffs_statfs;
89 static vfs_fhtovp_t ffs_fhtovp;
90 static vfs_sync_t ffs_sync;
91 
92 static struct vfsops ufs_vfsops = {
93 	.vfs_extattrctl =	ffs_extattrctl,
94 	.vfs_fhtovp =		ffs_fhtovp,
95 	.vfs_init =		ffs_init,
96 	.vfs_mount =		ffs_mount,
97 	.vfs_cmount =		ffs_cmount,
98 	.vfs_quotactl =		ufs_quotactl,
99 	.vfs_root =		ufs_root,
100 	.vfs_statfs =		ffs_statfs,
101 	.vfs_sync =		ffs_sync,
102 	.vfs_uninit =		ffs_uninit,
103 	.vfs_unmount =		ffs_unmount,
104 	.vfs_vget =		ffs_vget,
105 };
106 
107 VFS_SET(ufs_vfsops, ufs, 0);
108 MODULE_VERSION(ufs, 1);
109 
110 static b_strategy_t ffs_geom_strategy;
111 static b_write_t ffs_bufwrite;
112 
113 static struct buf_ops ffs_ops = {
114 	.bop_name =	"FFS",
115 	.bop_write =	ffs_bufwrite,
116 	.bop_strategy =	ffs_geom_strategy,
117 	.bop_sync =	bufsync,
118 #ifdef NO_FFS_SNAPSHOT
119 	.bop_bdflush =	bufbdflush,
120 #else
121 	.bop_bdflush =	ffs_bdflush,
122 #endif
123 };
124 
125 static const char *ffs_opts[] = { "acls", "async", "atime", "clusterr",
126     "clusterw", "exec", "export", "force", "from", "multilabel",
127     "snapshot", "suid", "suiddir", "symfollow", "sync",
128     "union", NULL };
129 
130 static int
131 ffs_mount(struct mount *mp, struct thread *td)
132 {
133 	struct vnode *devvp;
134 	struct ufsmount *ump = 0;
135 	struct fs *fs;
136 	int error, flags;
137 	u_int mntorflags, mntandnotflags;
138 	mode_t accessmode;
139 	struct nameidata ndp;
140 	char *fspec;
141 
142 	if (vfs_filteropt(mp->mnt_optnew, ffs_opts))
143 		return (EINVAL);
144 	if (uma_inode == NULL) {
145 		uma_inode = uma_zcreate("FFS inode",
146 		    sizeof(struct inode), NULL, NULL, NULL, NULL,
147 		    UMA_ALIGN_PTR, 0);
148 		uma_ufs1 = uma_zcreate("FFS1 dinode",
149 		    sizeof(struct ufs1_dinode), NULL, NULL, NULL, NULL,
150 		    UMA_ALIGN_PTR, 0);
151 		uma_ufs2 = uma_zcreate("FFS2 dinode",
152 		    sizeof(struct ufs2_dinode), NULL, NULL, NULL, NULL,
153 		    UMA_ALIGN_PTR, 0);
154 	}
155 
156 	fspec = vfs_getopts(mp->mnt_optnew, "from", &error);
157 	if (error)
158 		return (error);
159 
160 	mntorflags = 0;
161 	mntandnotflags = 0;
162 	if (vfs_getopt(mp->mnt_optnew, "acls", NULL, NULL) == 0)
163 		mntorflags |= MNT_ACLS;
164 
165 	if (vfs_getopt(mp->mnt_optnew, "async", NULL, NULL) == 0)
166 		mntorflags |= MNT_ASYNC;
167 
168 	if (vfs_getopt(mp->mnt_optnew, "force", NULL, NULL) == 0)
169 		mntorflags |= MNT_FORCE;
170 
171 	if (vfs_getopt(mp->mnt_optnew, "multilabel", NULL, NULL) == 0)
172 		mntorflags |= MNT_MULTILABEL;
173 
174 	if (vfs_getopt(mp->mnt_optnew, "noasync", NULL, NULL) == 0)
175 		mntandnotflags |= MNT_ASYNC;
176 
177 	if (vfs_getopt(mp->mnt_optnew, "noatime", NULL, NULL) == 0)
178 		mntorflags |= MNT_NOATIME;
179 
180 	if (vfs_getopt(mp->mnt_optnew, "noclusterr", NULL, NULL) == 0)
181 		mntorflags |= MNT_NOCLUSTERR;
182 
183 	if (vfs_getopt(mp->mnt_optnew, "noclusterw", NULL, NULL) == 0)
184 		mntorflags |= MNT_NOCLUSTERW;
185 
186 	if (vfs_getopt(mp->mnt_optnew, "snapshot", NULL, NULL) == 0)
187 		mntorflags |= MNT_SNAPSHOT;
188 
189 	MNT_ILOCK(mp);
190 	mp->mnt_flag = (mp->mnt_flag | mntorflags) & ~mntandnotflags;
191 	MNT_IUNLOCK(mp);
192 	/*
193 	 * If updating, check whether changing from read-only to
194 	 * read/write; if there is no device name, that's all we do.
195 	 */
196 	if (mp->mnt_flag & MNT_UPDATE) {
197 		ump = VFSTOUFS(mp);
198 		fs = ump->um_fs;
199 		devvp = ump->um_devvp;
200 		if (fs->fs_ronly == 0 &&
201 		    vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0)) {
202 			if ((error = vn_start_write(NULL, &mp, V_WAIT)) != 0)
203 				return (error);
204 			/*
205 			 * Flush any dirty data.
206 			 */
207 			if ((error = ffs_sync(mp, MNT_WAIT, td)) != 0) {
208 				vn_finished_write(mp);
209 				return (error);
210 			}
211 			/*
212 			 * Check for and optionally get rid of files open
213 			 * for writing.
214 			 */
215 			flags = WRITECLOSE;
216 			if (mp->mnt_flag & MNT_FORCE)
217 				flags |= FORCECLOSE;
218 			if (mp->mnt_flag & MNT_SOFTDEP) {
219 				error = softdep_flushfiles(mp, flags, td);
220 			} else {
221 				error = ffs_flushfiles(mp, flags, td);
222 			}
223 			if (error) {
224 				vn_finished_write(mp);
225 				return (error);
226 			}
227 			if (fs->fs_pendingblocks != 0 ||
228 			    fs->fs_pendinginodes != 0) {
229 				printf("%s: %s: blocks %jd files %d\n",
230 				    fs->fs_fsmnt, "update error",
231 				    (intmax_t)fs->fs_pendingblocks,
232 				    fs->fs_pendinginodes);
233 				fs->fs_pendingblocks = 0;
234 				fs->fs_pendinginodes = 0;
235 			}
236 			if ((fs->fs_flags & (FS_UNCLEAN | FS_NEEDSFSCK)) == 0)
237 				fs->fs_clean = 1;
238 			if ((error = ffs_sbupdate(ump, MNT_WAIT, 0)) != 0) {
239 				fs->fs_ronly = 0;
240 				fs->fs_clean = 0;
241 				vn_finished_write(mp);
242 				return (error);
243 			}
244 			vn_finished_write(mp);
245 			DROP_GIANT();
246 			g_topology_lock();
247 			g_access(ump->um_cp, 0, -1, 0);
248 			g_topology_unlock();
249 			PICKUP_GIANT();
250 			fs->fs_ronly = 1;
251 			MNT_ILOCK(mp);
252 			mp->mnt_flag |= MNT_RDONLY;
253 			MNT_IUNLOCK(mp);
254 		}
255 		if ((mp->mnt_flag & MNT_RELOAD) &&
256 		    (error = ffs_reload(mp, td)) != 0)
257 			return (error);
258 		if (fs->fs_ronly &&
259 		    !vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0)) {
260 			/*
261 			 * If upgrade to read-write by non-root, then verify
262 			 * that user has necessary permissions on the device.
263 			 */
264 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
265 			error = VOP_ACCESS(devvp, VREAD | VWRITE,
266 			    td->td_ucred, td);
267 			if (error)
268 				error = priv_check(td, PRIV_VFS_MOUNT_PERM);
269 			if (error) {
270 				VOP_UNLOCK(devvp, 0, td);
271 				return (error);
272 			}
273 			VOP_UNLOCK(devvp, 0, td);
274 			fs->fs_flags &= ~FS_UNCLEAN;
275 			if (fs->fs_clean == 0) {
276 				fs->fs_flags |= FS_UNCLEAN;
277 				if ((mp->mnt_flag & MNT_FORCE) ||
278 				    ((fs->fs_flags & FS_NEEDSFSCK) == 0 &&
279 				     (fs->fs_flags & FS_DOSOFTDEP))) {
280 					printf("WARNING: %s was not %s\n",
281 					   fs->fs_fsmnt, "properly dismounted");
282 				} else {
283 					printf(
284 "WARNING: R/W mount of %s denied.  Filesystem is not clean - run fsck\n",
285 					    fs->fs_fsmnt);
286 					return (EPERM);
287 				}
288 			}
289 			DROP_GIANT();
290 			g_topology_lock();
291 			/*
292 			 * If we're the root device, we may not have an E count
293 			 * yet, get it now.
294 			 */
295 			if (ump->um_cp->ace == 0)
296 				error = g_access(ump->um_cp, 0, 1, 1);
297 			else
298 				error = g_access(ump->um_cp, 0, 1, 0);
299 			g_topology_unlock();
300 			PICKUP_GIANT();
301 			if (error)
302 				return (error);
303 			if ((error = vn_start_write(NULL, &mp, V_WAIT)) != 0)
304 				return (error);
305 			fs->fs_ronly = 0;
306 			MNT_ILOCK(mp);
307 			mp->mnt_flag &= ~MNT_RDONLY;
308 			MNT_IUNLOCK(mp);
309 			fs->fs_clean = 0;
310 			if ((error = ffs_sbupdate(ump, MNT_WAIT, 0)) != 0) {
311 				vn_finished_write(mp);
312 				return (error);
313 			}
314 			/* check to see if we need to start softdep */
315 			if ((fs->fs_flags & FS_DOSOFTDEP) &&
316 			    (error = softdep_mount(devvp, mp, fs, td->td_ucred))){
317 				vn_finished_write(mp);
318 				return (error);
319 			}
320 			if (fs->fs_snapinum[0] != 0)
321 				ffs_snapshot_mount(mp);
322 			vn_finished_write(mp);
323 		}
324 		/*
325 		 * Soft updates is incompatible with "async",
326 		 * so if we are doing softupdates stop the user
327 		 * from setting the async flag in an update.
328 		 * Softdep_mount() clears it in an initial mount
329 		 * or ro->rw remount.
330 		 */
331 		if (mp->mnt_flag & MNT_SOFTDEP) {
332 			/* XXX: Reset too late ? */
333 			MNT_ILOCK(mp);
334 			mp->mnt_flag &= ~MNT_ASYNC;
335 			MNT_IUNLOCK(mp);
336 		}
337 		/*
338 		 * Keep MNT_ACLS flag if it is stored in superblock.
339 		 */
340 		if ((fs->fs_flags & FS_ACLS) != 0) {
341 			/* XXX: Set too late ? */
342 			MNT_ILOCK(mp);
343 			mp->mnt_flag |= MNT_ACLS;
344 			MNT_IUNLOCK(mp);
345 		}
346 
347 		/*
348 		 * If this is a snapshot request, take the snapshot.
349 		 */
350 		if (mp->mnt_flag & MNT_SNAPSHOT)
351 			return (ffs_snapshot(mp, fspec));
352 	}
353 
354 	/*
355 	 * Not an update, or updating the name: look up the name
356 	 * and verify that it refers to a sensible disk device.
357 	 */
358 	NDINIT(&ndp, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, fspec, td);
359 	if ((error = namei(&ndp)) != 0)
360 		return (error);
361 	NDFREE(&ndp, NDF_ONLY_PNBUF);
362 	devvp = ndp.ni_vp;
363 	if (!vn_isdisk(devvp, &error)) {
364 		vput(devvp);
365 		return (error);
366 	}
367 
368 	/*
369 	 * If mount by non-root, then verify that user has necessary
370 	 * permissions on the device.
371 	 */
372 	accessmode = VREAD;
373 	if ((mp->mnt_flag & MNT_RDONLY) == 0)
374 		accessmode |= VWRITE;
375 	error = VOP_ACCESS(devvp, accessmode, td->td_ucred, td);
376 	if (error)
377 		error = priv_check(td, PRIV_VFS_MOUNT_PERM);
378 	if (error) {
379 		vput(devvp);
380 		return (error);
381 	}
382 
383 	if (mp->mnt_flag & MNT_UPDATE) {
384 		/*
385 		 * Update only
386 		 *
387 		 * If it's not the same vnode, or at least the same device
388 		 * then it's not correct.
389 		 */
390 
391 		if (devvp->v_rdev != ump->um_devvp->v_rdev)
392 			error = EINVAL;	/* needs translation */
393 		vput(devvp);
394 		if (error)
395 			return (error);
396 	} else {
397 		/*
398 		 * New mount
399 		 *
400 		 * We need the name for the mount point (also used for
401 		 * "last mounted on") copied in. If an error occurs,
402 		 * the mount point is discarded by the upper level code.
403 		 * Note that vfs_mount() populates f_mntonname for us.
404 		 */
405 		if ((error = ffs_mountfs(devvp, mp, td)) != 0) {
406 			vrele(devvp);
407 			return (error);
408 		}
409 	}
410 	vfs_mountedfrom(mp, fspec);
411 	return (0);
412 }
413 
414 /*
415  * Compatibility with old mount system call.
416  */
417 
418 static int
419 ffs_cmount(struct mntarg *ma, void *data, int flags, struct thread *td)
420 {
421 	struct ufs_args args;
422 	int error;
423 
424 	if (data == NULL)
425 		return (EINVAL);
426 	error = copyin(data, &args, sizeof args);
427 	if (error)
428 		return (error);
429 
430 	ma = mount_argsu(ma, "from", args.fspec, MAXPATHLEN);
431 	ma = mount_arg(ma, "export", &args.export, sizeof args.export);
432 	error = kernel_mount(ma, flags);
433 
434 	return (error);
435 }
436 
437 /*
438  * Reload all incore data for a filesystem (used after running fsck on
439  * the root filesystem and finding things to fix). The filesystem must
440  * be mounted read-only.
441  *
442  * Things to do to update the mount:
443  *	1) invalidate all cached meta-data.
444  *	2) re-read superblock from disk.
445  *	3) re-read summary information from disk.
446  *	4) invalidate all inactive vnodes.
447  *	5) invalidate all cached file data.
448  *	6) re-read inode data for all active vnodes.
449  */
450 static int
451 ffs_reload(struct mount *mp, struct thread *td)
452 {
453 	struct vnode *vp, *mvp, *devvp;
454 	struct inode *ip;
455 	void *space;
456 	struct buf *bp;
457 	struct fs *fs, *newfs;
458 	struct ufsmount *ump;
459 	ufs2_daddr_t sblockloc;
460 	int i, blks, size, error;
461 	int32_t *lp;
462 
463 	if ((mp->mnt_flag & MNT_RDONLY) == 0)
464 		return (EINVAL);
465 	ump = VFSTOUFS(mp);
466 	/*
467 	 * Step 1: invalidate all cached meta-data.
468 	 */
469 	devvp = VFSTOUFS(mp)->um_devvp;
470 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
471 	if (vinvalbuf(devvp, 0, td, 0, 0) != 0)
472 		panic("ffs_reload: dirty1");
473 	VOP_UNLOCK(devvp, 0, td);
474 
475 	/*
476 	 * Step 2: re-read superblock from disk.
477 	 */
478 	fs = VFSTOUFS(mp)->um_fs;
479 	if ((error = bread(devvp, btodb(fs->fs_sblockloc), fs->fs_sbsize,
480 	    NOCRED, &bp)) != 0)
481 		return (error);
482 	newfs = (struct fs *)bp->b_data;
483 	if ((newfs->fs_magic != FS_UFS1_MAGIC &&
484 	     newfs->fs_magic != FS_UFS2_MAGIC) ||
485 	    newfs->fs_bsize > MAXBSIZE ||
486 	    newfs->fs_bsize < sizeof(struct fs)) {
487 			brelse(bp);
488 			return (EIO);		/* XXX needs translation */
489 	}
490 	/*
491 	 * Copy pointer fields back into superblock before copying in	XXX
492 	 * new superblock. These should really be in the ufsmount.	XXX
493 	 * Note that important parameters (eg fs_ncg) are unchanged.
494 	 */
495 	newfs->fs_csp = fs->fs_csp;
496 	newfs->fs_maxcluster = fs->fs_maxcluster;
497 	newfs->fs_contigdirs = fs->fs_contigdirs;
498 	newfs->fs_active = fs->fs_active;
499 	/* The file system is still read-only. */
500 	newfs->fs_ronly = 1;
501 	sblockloc = fs->fs_sblockloc;
502 	bcopy(newfs, fs, (u_int)fs->fs_sbsize);
503 	brelse(bp);
504 	mp->mnt_maxsymlinklen = fs->fs_maxsymlinklen;
505 	ffs_oldfscompat_read(fs, VFSTOUFS(mp), sblockloc);
506 	UFS_LOCK(ump);
507 	if (fs->fs_pendingblocks != 0 || fs->fs_pendinginodes != 0) {
508 		printf("%s: reload pending error: blocks %jd files %d\n",
509 		    fs->fs_fsmnt, (intmax_t)fs->fs_pendingblocks,
510 		    fs->fs_pendinginodes);
511 		fs->fs_pendingblocks = 0;
512 		fs->fs_pendinginodes = 0;
513 	}
514 	UFS_UNLOCK(ump);
515 
516 	/*
517 	 * Step 3: re-read summary information from disk.
518 	 */
519 	blks = howmany(fs->fs_cssize, fs->fs_fsize);
520 	space = fs->fs_csp;
521 	for (i = 0; i < blks; i += fs->fs_frag) {
522 		size = fs->fs_bsize;
523 		if (i + fs->fs_frag > blks)
524 			size = (blks - i) * fs->fs_fsize;
525 		error = bread(devvp, fsbtodb(fs, fs->fs_csaddr + i), size,
526 		    NOCRED, &bp);
527 		if (error)
528 			return (error);
529 		bcopy(bp->b_data, space, (u_int)size);
530 		space = (char *)space + size;
531 		brelse(bp);
532 	}
533 	/*
534 	 * We no longer know anything about clusters per cylinder group.
535 	 */
536 	if (fs->fs_contigsumsize > 0) {
537 		lp = fs->fs_maxcluster;
538 		for (i = 0; i < fs->fs_ncg; i++)
539 			*lp++ = fs->fs_contigsumsize;
540 	}
541 
542 loop:
543 	MNT_ILOCK(mp);
544 	MNT_VNODE_FOREACH(vp, mp, mvp) {
545 		VI_LOCK(vp);
546 		if (vp->v_iflag & VI_DOOMED) {
547 			VI_UNLOCK(vp);
548 			continue;
549 		}
550 		MNT_IUNLOCK(mp);
551 		/*
552 		 * Step 4: invalidate all cached file data.
553 		 */
554 		if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, td)) {
555 			MNT_VNODE_FOREACH_ABORT(mp, mvp);
556 			goto loop;
557 		}
558 		if (vinvalbuf(vp, 0, td, 0, 0))
559 			panic("ffs_reload: dirty2");
560 		/*
561 		 * Step 5: re-read inode data for all active vnodes.
562 		 */
563 		ip = VTOI(vp);
564 		error =
565 		    bread(devvp, fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
566 		    (int)fs->fs_bsize, NOCRED, &bp);
567 		if (error) {
568 			VOP_UNLOCK(vp, 0, td);
569 			vrele(vp);
570 			MNT_VNODE_FOREACH_ABORT(mp, mvp);
571 			return (error);
572 		}
573 		ffs_load_inode(bp, ip, fs, ip->i_number);
574 		ip->i_effnlink = ip->i_nlink;
575 		brelse(bp);
576 		VOP_UNLOCK(vp, 0, td);
577 		vrele(vp);
578 		MNT_ILOCK(mp);
579 	}
580 	MNT_IUNLOCK(mp);
581 	return (0);
582 }
583 
584 /*
585  * Possible superblock locations ordered from most to least likely.
586  */
587 static int sblock_try[] = SBLOCKSEARCH;
588 
589 /*
590  * Common code for mount and mountroot
591  */
592 static int
593 ffs_mountfs(devvp, mp, td)
594 	struct vnode *devvp;
595 	struct mount *mp;
596 	struct thread *td;
597 {
598 	struct ufsmount *ump;
599 	struct buf *bp;
600 	struct fs *fs;
601 	struct cdev *dev;
602 	void *space;
603 	ufs2_daddr_t sblockloc;
604 	int error, i, blks, size, ronly;
605 	int32_t *lp;
606 	struct ucred *cred;
607 	struct g_consumer *cp;
608 	struct mount *nmp;
609 
610 	dev = devvp->v_rdev;
611 	cred = td ? td->td_ucred : NOCRED;
612 
613 	ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
614 	DROP_GIANT();
615 	g_topology_lock();
616 	error = g_vfs_open(devvp, &cp, "ffs", ronly ? 0 : 1);
617 
618 	/*
619 	 * If we are a root mount, drop the E flag so fsck can do its magic.
620 	 * We will pick it up again when we remount R/W.
621 	 */
622 	if (error == 0 && ronly && (mp->mnt_flag & MNT_ROOTFS))
623 		error = g_access(cp, 0, 0, -1);
624 	g_topology_unlock();
625 	PICKUP_GIANT();
626 	VOP_UNLOCK(devvp, 0, td);
627 	if (error)
628 		return (error);
629 	if (devvp->v_rdev->si_iosize_max != 0)
630 		mp->mnt_iosize_max = devvp->v_rdev->si_iosize_max;
631 	if (mp->mnt_iosize_max > MAXPHYS)
632 		mp->mnt_iosize_max = MAXPHYS;
633 
634 	devvp->v_bufobj.bo_private = cp;
635 	devvp->v_bufobj.bo_ops = &ffs_ops;
636 
637 	bp = NULL;
638 	ump = NULL;
639 	fs = NULL;
640 	sblockloc = 0;
641 	/*
642 	 * Try reading the superblock in each of its possible locations.
643 	 */
644 	for (i = 0; sblock_try[i] != -1; i++) {
645 		if ((SBLOCKSIZE % cp->provider->sectorsize) != 0) {
646 			error = EINVAL;
647 			vfs_mount_error(mp,
648 			    "Invalid sectorsize %d for superblock size %d",
649 			    cp->provider->sectorsize, SBLOCKSIZE);
650 			goto out;
651 		}
652 		if ((error = bread(devvp, btodb(sblock_try[i]), SBLOCKSIZE,
653 		    cred, &bp)) != 0)
654 			goto out;
655 		fs = (struct fs *)bp->b_data;
656 		sblockloc = sblock_try[i];
657 		if ((fs->fs_magic == FS_UFS1_MAGIC ||
658 		     (fs->fs_magic == FS_UFS2_MAGIC &&
659 		      (fs->fs_sblockloc == sblockloc ||
660 		       (fs->fs_old_flags & FS_FLAGS_UPDATED) == 0))) &&
661 		    fs->fs_bsize <= MAXBSIZE &&
662 		    fs->fs_bsize >= sizeof(struct fs))
663 			break;
664 		brelse(bp);
665 		bp = NULL;
666 	}
667 	if (sblock_try[i] == -1) {
668 		error = EINVAL;		/* XXX needs translation */
669 		goto out;
670 	}
671 	fs->fs_fmod = 0;
672 	fs->fs_flags &= ~FS_INDEXDIRS;	/* no support for directory indicies */
673 	fs->fs_flags &= ~FS_UNCLEAN;
674 	if (fs->fs_clean == 0) {
675 		fs->fs_flags |= FS_UNCLEAN;
676 		if (ronly || (mp->mnt_flag & MNT_FORCE) ||
677 		    ((fs->fs_flags & FS_NEEDSFSCK) == 0 &&
678 		     (fs->fs_flags & FS_DOSOFTDEP))) {
679 			printf(
680 "WARNING: %s was not properly dismounted\n",
681 			    fs->fs_fsmnt);
682 		} else {
683 			printf(
684 "WARNING: R/W mount of %s denied.  Filesystem is not clean - run fsck\n",
685 			    fs->fs_fsmnt);
686 			error = EPERM;
687 			goto out;
688 		}
689 		if ((fs->fs_pendingblocks != 0 || fs->fs_pendinginodes != 0) &&
690 		    (mp->mnt_flag & MNT_FORCE)) {
691 			printf("%s: lost blocks %jd files %d\n", fs->fs_fsmnt,
692 			    (intmax_t)fs->fs_pendingblocks,
693 			    fs->fs_pendinginodes);
694 			fs->fs_pendingblocks = 0;
695 			fs->fs_pendinginodes = 0;
696 		}
697 	}
698 	if (fs->fs_pendingblocks != 0 || fs->fs_pendinginodes != 0) {
699 		printf("%s: mount pending error: blocks %jd files %d\n",
700 		    fs->fs_fsmnt, (intmax_t)fs->fs_pendingblocks,
701 		    fs->fs_pendinginodes);
702 		fs->fs_pendingblocks = 0;
703 		fs->fs_pendinginodes = 0;
704 	}
705 	if ((fs->fs_flags & FS_GJOURNAL) != 0) {
706 #ifdef UFS_GJOURNAL
707 		/*
708 		 * Get journal provider name.
709 		 */
710 		size = 1024;
711 		mp->mnt_gjprovider = malloc(size, M_UFSMNT, M_WAITOK);
712 		if (g_io_getattr("GJOURNAL::provider", cp, &size,
713 		    mp->mnt_gjprovider) == 0) {
714 			mp->mnt_gjprovider = realloc(mp->mnt_gjprovider, size,
715 			    M_UFSMNT, M_WAITOK);
716 			MNT_ILOCK(mp);
717 			mp->mnt_flag |= MNT_GJOURNAL;
718 			MNT_IUNLOCK(mp);
719 		} else {
720 			printf(
721 "WARNING: %s: GJOURNAL flag on fs but no gjournal provider below\n",
722 			    mp->mnt_stat.f_mntonname);
723 			free(mp->mnt_gjprovider, M_UFSMNT);
724 			mp->mnt_gjprovider = NULL;
725 		}
726 #else
727 		printf(
728 "WARNING: %s: GJOURNAL flag on fs but no UFS_GJOURNAL support\n",
729 		    mp->mnt_stat.f_mntonname);
730 #endif
731 	} else {
732 		mp->mnt_gjprovider = NULL;
733 	}
734 	ump = malloc(sizeof *ump, M_UFSMNT, M_WAITOK | M_ZERO);
735 	ump->um_cp = cp;
736 	ump->um_bo = &devvp->v_bufobj;
737 	ump->um_fs = malloc((u_long)fs->fs_sbsize, M_UFSMNT, M_WAITOK);
738 	if (fs->fs_magic == FS_UFS1_MAGIC) {
739 		ump->um_fstype = UFS1;
740 		ump->um_balloc = ffs_balloc_ufs1;
741 	} else {
742 		ump->um_fstype = UFS2;
743 		ump->um_balloc = ffs_balloc_ufs2;
744 	}
745 	ump->um_blkatoff = ffs_blkatoff;
746 	ump->um_truncate = ffs_truncate;
747 	ump->um_update = ffs_update;
748 	ump->um_valloc = ffs_valloc;
749 	ump->um_vfree = ffs_vfree;
750 	ump->um_ifree = ffs_ifree;
751 	mtx_init(UFS_MTX(ump), "FFS", "FFS Lock", MTX_DEF);
752 	bcopy(bp->b_data, ump->um_fs, (u_int)fs->fs_sbsize);
753 	if (fs->fs_sbsize < SBLOCKSIZE)
754 		bp->b_flags |= B_INVAL | B_NOCACHE;
755 	brelse(bp);
756 	bp = NULL;
757 	fs = ump->um_fs;
758 	ffs_oldfscompat_read(fs, ump, sblockloc);
759 	fs->fs_ronly = ronly;
760 	size = fs->fs_cssize;
761 	blks = howmany(size, fs->fs_fsize);
762 	if (fs->fs_contigsumsize > 0)
763 		size += fs->fs_ncg * sizeof(int32_t);
764 	size += fs->fs_ncg * sizeof(u_int8_t);
765 	space = malloc((u_long)size, M_UFSMNT, M_WAITOK);
766 	fs->fs_csp = space;
767 	for (i = 0; i < blks; i += fs->fs_frag) {
768 		size = fs->fs_bsize;
769 		if (i + fs->fs_frag > blks)
770 			size = (blks - i) * fs->fs_fsize;
771 		if ((error = bread(devvp, fsbtodb(fs, fs->fs_csaddr + i), size,
772 		    cred, &bp)) != 0) {
773 			free(fs->fs_csp, M_UFSMNT);
774 			goto out;
775 		}
776 		bcopy(bp->b_data, space, (u_int)size);
777 		space = (char *)space + size;
778 		brelse(bp);
779 		bp = NULL;
780 	}
781 	if (fs->fs_contigsumsize > 0) {
782 		fs->fs_maxcluster = lp = space;
783 		for (i = 0; i < fs->fs_ncg; i++)
784 			*lp++ = fs->fs_contigsumsize;
785 		space = lp;
786 	}
787 	size = fs->fs_ncg * sizeof(u_int8_t);
788 	fs->fs_contigdirs = (u_int8_t *)space;
789 	bzero(fs->fs_contigdirs, size);
790 	fs->fs_active = NULL;
791 	mp->mnt_data = ump;
792 	mp->mnt_stat.f_fsid.val[0] = fs->fs_id[0];
793 	mp->mnt_stat.f_fsid.val[1] = fs->fs_id[1];
794 	nmp = NULL;
795 	if (fs->fs_id[0] == 0 || fs->fs_id[1] == 0 ||
796 	    (nmp = vfs_getvfs(&mp->mnt_stat.f_fsid))) {
797 		if (nmp)
798 			vfs_rel(nmp);
799 		vfs_getnewfsid(mp);
800 	}
801 	mp->mnt_maxsymlinklen = fs->fs_maxsymlinklen;
802 	MNT_ILOCK(mp);
803 	mp->mnt_flag |= MNT_LOCAL;
804 	MNT_IUNLOCK(mp);
805 	if ((fs->fs_flags & FS_MULTILABEL) != 0) {
806 #ifdef MAC
807 		MNT_ILOCK(mp);
808 		mp->mnt_flag |= MNT_MULTILABEL;
809 		MNT_IUNLOCK(mp);
810 #else
811 		printf(
812 "WARNING: %s: multilabel flag on fs but no MAC support\n",
813 		    mp->mnt_stat.f_mntonname);
814 #endif
815 	}
816 	if ((fs->fs_flags & FS_ACLS) != 0) {
817 #ifdef UFS_ACL
818 		MNT_ILOCK(mp);
819 		mp->mnt_flag |= MNT_ACLS;
820 		MNT_IUNLOCK(mp);
821 #else
822 		printf(
823 "WARNING: %s: ACLs flag on fs but no ACLs support\n",
824 		    mp->mnt_stat.f_mntonname);
825 #endif
826 	}
827 	ump->um_mountp = mp;
828 	ump->um_dev = dev;
829 	ump->um_devvp = devvp;
830 	ump->um_nindir = fs->fs_nindir;
831 	ump->um_bptrtodb = fs->fs_fsbtodb;
832 	ump->um_seqinc = fs->fs_frag;
833 	for (i = 0; i < MAXQUOTAS; i++)
834 		ump->um_quotas[i] = NULLVP;
835 #ifdef UFS_EXTATTR
836 	ufs_extattr_uepm_init(&ump->um_extattr);
837 #endif
838 	/*
839 	 * Set FS local "last mounted on" information (NULL pad)
840 	 */
841 	bzero(fs->fs_fsmnt, MAXMNTLEN);
842 	strlcpy(fs->fs_fsmnt, mp->mnt_stat.f_mntonname, MAXMNTLEN);
843 
844 	if( mp->mnt_flag & MNT_ROOTFS) {
845 		/*
846 		 * Root mount; update timestamp in mount structure.
847 		 * this will be used by the common root mount code
848 		 * to update the system clock.
849 		 */
850 		mp->mnt_time = fs->fs_time;
851 	}
852 
853 	if (ronly == 0) {
854 		if ((fs->fs_flags & FS_DOSOFTDEP) &&
855 		    (error = softdep_mount(devvp, mp, fs, cred)) != 0) {
856 			free(fs->fs_csp, M_UFSMNT);
857 			goto out;
858 		}
859 		if (fs->fs_snapinum[0] != 0)
860 			ffs_snapshot_mount(mp);
861 		fs->fs_fmod = 1;
862 		fs->fs_clean = 0;
863 		(void) ffs_sbupdate(ump, MNT_WAIT, 0);
864 	}
865 	/*
866 	 * Initialize filesystem stat information in mount struct.
867 	 */
868 #ifdef UFS_EXTATTR
869 #ifdef UFS_EXTATTR_AUTOSTART
870 	/*
871 	 *
872 	 * Auto-starting does the following:
873 	 *	- check for /.attribute in the fs, and extattr_start if so
874 	 *	- for each file in .attribute, enable that file with
875 	 * 	  an attribute of the same name.
876 	 * Not clear how to report errors -- probably eat them.
877 	 * This would all happen while the filesystem was busy/not
878 	 * available, so would effectively be "atomic".
879 	 */
880 	(void) ufs_extattr_autostart(mp, td);
881 #endif /* !UFS_EXTATTR_AUTOSTART */
882 #endif /* !UFS_EXTATTR */
883 	MNT_ILOCK(mp);
884 	mp->mnt_kern_flag |= MNTK_MPSAFE;
885 	MNT_IUNLOCK(mp);
886 	return (0);
887 out:
888 	if (bp)
889 		brelse(bp);
890 	if (cp != NULL) {
891 		DROP_GIANT();
892 		g_topology_lock();
893 		g_vfs_close(cp, td);
894 		g_topology_unlock();
895 		PICKUP_GIANT();
896 	}
897 	if (ump) {
898 		mtx_destroy(UFS_MTX(ump));
899 		if (mp->mnt_gjprovider != NULL) {
900 			free(mp->mnt_gjprovider, M_UFSMNT);
901 			mp->mnt_gjprovider = NULL;
902 		}
903 		free(ump->um_fs, M_UFSMNT);
904 		free(ump, M_UFSMNT);
905 		mp->mnt_data = NULL;
906 	}
907 	return (error);
908 }
909 
910 #include <sys/sysctl.h>
911 static int bigcgs = 0;
912 SYSCTL_INT(_debug, OID_AUTO, bigcgs, CTLFLAG_RW, &bigcgs, 0, "");
913 
914 /*
915  * Sanity checks for loading old filesystem superblocks.
916  * See ffs_oldfscompat_write below for unwound actions.
917  *
918  * XXX - Parts get retired eventually.
919  * Unfortunately new bits get added.
920  */
921 static void
922 ffs_oldfscompat_read(fs, ump, sblockloc)
923 	struct fs *fs;
924 	struct ufsmount *ump;
925 	ufs2_daddr_t sblockloc;
926 {
927 	off_t maxfilesize;
928 
929 	/*
930 	 * If not yet done, update fs_flags location and value of fs_sblockloc.
931 	 */
932 	if ((fs->fs_old_flags & FS_FLAGS_UPDATED) == 0) {
933 		fs->fs_flags = fs->fs_old_flags;
934 		fs->fs_old_flags |= FS_FLAGS_UPDATED;
935 		fs->fs_sblockloc = sblockloc;
936 	}
937 	/*
938 	 * If not yet done, update UFS1 superblock with new wider fields.
939 	 */
940 	if (fs->fs_magic == FS_UFS1_MAGIC && fs->fs_maxbsize != fs->fs_bsize) {
941 		fs->fs_maxbsize = fs->fs_bsize;
942 		fs->fs_time = fs->fs_old_time;
943 		fs->fs_size = fs->fs_old_size;
944 		fs->fs_dsize = fs->fs_old_dsize;
945 		fs->fs_csaddr = fs->fs_old_csaddr;
946 		fs->fs_cstotal.cs_ndir = fs->fs_old_cstotal.cs_ndir;
947 		fs->fs_cstotal.cs_nbfree = fs->fs_old_cstotal.cs_nbfree;
948 		fs->fs_cstotal.cs_nifree = fs->fs_old_cstotal.cs_nifree;
949 		fs->fs_cstotal.cs_nffree = fs->fs_old_cstotal.cs_nffree;
950 	}
951 	if (fs->fs_magic == FS_UFS1_MAGIC &&
952 	    fs->fs_old_inodefmt < FS_44INODEFMT) {
953 		fs->fs_maxfilesize = ((uint64_t)1 << 31) - 1;
954 		fs->fs_qbmask = ~fs->fs_bmask;
955 		fs->fs_qfmask = ~fs->fs_fmask;
956 	}
957 	if (fs->fs_magic == FS_UFS1_MAGIC) {
958 		ump->um_savedmaxfilesize = fs->fs_maxfilesize;
959 		maxfilesize = (uint64_t)0x80000000 * fs->fs_bsize - 1;
960 		if (fs->fs_maxfilesize > maxfilesize)
961 			fs->fs_maxfilesize = maxfilesize;
962 	}
963 	/* Compatibility for old filesystems */
964 	if (fs->fs_avgfilesize <= 0)
965 		fs->fs_avgfilesize = AVFILESIZ;
966 	if (fs->fs_avgfpdir <= 0)
967 		fs->fs_avgfpdir = AFPDIR;
968 	if (bigcgs) {
969 		fs->fs_save_cgsize = fs->fs_cgsize;
970 		fs->fs_cgsize = fs->fs_bsize;
971 	}
972 }
973 
974 /*
975  * Unwinding superblock updates for old filesystems.
976  * See ffs_oldfscompat_read above for details.
977  *
978  * XXX - Parts get retired eventually.
979  * Unfortunately new bits get added.
980  */
981 static void
982 ffs_oldfscompat_write(fs, ump)
983 	struct fs *fs;
984 	struct ufsmount *ump;
985 {
986 
987 	/*
988 	 * Copy back UFS2 updated fields that UFS1 inspects.
989 	 */
990 	if (fs->fs_magic == FS_UFS1_MAGIC) {
991 		fs->fs_old_time = fs->fs_time;
992 		fs->fs_old_cstotal.cs_ndir = fs->fs_cstotal.cs_ndir;
993 		fs->fs_old_cstotal.cs_nbfree = fs->fs_cstotal.cs_nbfree;
994 		fs->fs_old_cstotal.cs_nifree = fs->fs_cstotal.cs_nifree;
995 		fs->fs_old_cstotal.cs_nffree = fs->fs_cstotal.cs_nffree;
996 		fs->fs_maxfilesize = ump->um_savedmaxfilesize;
997 	}
998 	if (bigcgs) {
999 		fs->fs_cgsize = fs->fs_save_cgsize;
1000 		fs->fs_save_cgsize = 0;
1001 	}
1002 }
1003 
1004 /*
1005  * unmount system call
1006  */
1007 static int
1008 ffs_unmount(mp, mntflags, td)
1009 	struct mount *mp;
1010 	int mntflags;
1011 	struct thread *td;
1012 {
1013 	struct ufsmount *ump = VFSTOUFS(mp);
1014 	struct fs *fs;
1015 	int error, flags;
1016 
1017 	flags = 0;
1018 	if (mntflags & MNT_FORCE) {
1019 		flags |= FORCECLOSE;
1020 	}
1021 #ifdef UFS_EXTATTR
1022 	if ((error = ufs_extattr_stop(mp, td))) {
1023 		if (error != EOPNOTSUPP)
1024 			printf("ffs_unmount: ufs_extattr_stop returned %d\n",
1025 			    error);
1026 	} else {
1027 		ufs_extattr_uepm_destroy(&ump->um_extattr);
1028 	}
1029 #endif
1030 	if (mp->mnt_flag & MNT_SOFTDEP) {
1031 		if ((error = softdep_flushfiles(mp, flags, td)) != 0)
1032 			return (error);
1033 	} else {
1034 		if ((error = ffs_flushfiles(mp, flags, td)) != 0)
1035 			return (error);
1036 	}
1037 	fs = ump->um_fs;
1038 	UFS_LOCK(ump);
1039 	if (fs->fs_pendingblocks != 0 || fs->fs_pendinginodes != 0) {
1040 		printf("%s: unmount pending error: blocks %jd files %d\n",
1041 		    fs->fs_fsmnt, (intmax_t)fs->fs_pendingblocks,
1042 		    fs->fs_pendinginodes);
1043 		fs->fs_pendingblocks = 0;
1044 		fs->fs_pendinginodes = 0;
1045 	}
1046 	UFS_UNLOCK(ump);
1047 	if (fs->fs_ronly == 0) {
1048 		fs->fs_clean = fs->fs_flags & (FS_UNCLEAN|FS_NEEDSFSCK) ? 0 : 1;
1049 		error = ffs_sbupdate(ump, MNT_WAIT, 0);
1050 		if (error) {
1051 			fs->fs_clean = 0;
1052 			return (error);
1053 		}
1054 	}
1055 	DROP_GIANT();
1056 	g_topology_lock();
1057 	g_vfs_close(ump->um_cp, td);
1058 	g_topology_unlock();
1059 	PICKUP_GIANT();
1060 	vrele(ump->um_devvp);
1061 	mtx_destroy(UFS_MTX(ump));
1062 	if (mp->mnt_gjprovider != NULL) {
1063 		free(mp->mnt_gjprovider, M_UFSMNT);
1064 		mp->mnt_gjprovider = NULL;
1065 	}
1066 	free(fs->fs_csp, M_UFSMNT);
1067 	free(fs, M_UFSMNT);
1068 	free(ump, M_UFSMNT);
1069 	mp->mnt_data = NULL;
1070 	MNT_ILOCK(mp);
1071 	mp->mnt_flag &= ~MNT_LOCAL;
1072 	MNT_IUNLOCK(mp);
1073 	return (error);
1074 }
1075 
1076 /*
1077  * Flush out all the files in a filesystem.
1078  */
1079 int
1080 ffs_flushfiles(mp, flags, td)
1081 	struct mount *mp;
1082 	int flags;
1083 	struct thread *td;
1084 {
1085 	struct ufsmount *ump;
1086 	int error;
1087 
1088 	ump = VFSTOUFS(mp);
1089 #ifdef QUOTA
1090 	if (mp->mnt_flag & MNT_QUOTA) {
1091 		int i;
1092 		error = vflush(mp, 0, SKIPSYSTEM|flags, td);
1093 		if (error)
1094 			return (error);
1095 		for (i = 0; i < MAXQUOTAS; i++) {
1096 			quotaoff(td, mp, i);
1097 		}
1098 		/*
1099 		 * Here we fall through to vflush again to ensure
1100 		 * that we have gotten rid of all the system vnodes.
1101 		 */
1102 	}
1103 #endif
1104 	ASSERT_VOP_LOCKED(ump->um_devvp, "ffs_flushfiles");
1105 	if (ump->um_devvp->v_vflag & VV_COPYONWRITE) {
1106 		if ((error = vflush(mp, 0, SKIPSYSTEM | flags, td)) != 0)
1107 			return (error);
1108 		ffs_snapshot_unmount(mp);
1109 		flags |= FORCECLOSE;
1110 		/*
1111 		 * Here we fall through to vflush again to ensure
1112 		 * that we have gotten rid of all the system vnodes.
1113 		 */
1114 	}
1115         /*
1116 	 * Flush all the files.
1117 	 */
1118 	if ((error = vflush(mp, 0, flags, td)) != 0)
1119 		return (error);
1120 	/*
1121 	 * Flush filesystem metadata.
1122 	 */
1123 	vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY, td);
1124 	error = VOP_FSYNC(ump->um_devvp, MNT_WAIT, td);
1125 	VOP_UNLOCK(ump->um_devvp, 0, td);
1126 	return (error);
1127 }
1128 
1129 /*
1130  * Get filesystem statistics.
1131  */
1132 static int
1133 ffs_statfs(mp, sbp, td)
1134 	struct mount *mp;
1135 	struct statfs *sbp;
1136 	struct thread *td;
1137 {
1138 	struct ufsmount *ump;
1139 	struct fs *fs;
1140 
1141 	ump = VFSTOUFS(mp);
1142 	fs = ump->um_fs;
1143 	if (fs->fs_magic != FS_UFS1_MAGIC && fs->fs_magic != FS_UFS2_MAGIC)
1144 		panic("ffs_statfs");
1145 	sbp->f_version = STATFS_VERSION;
1146 	sbp->f_bsize = fs->fs_fsize;
1147 	sbp->f_iosize = fs->fs_bsize;
1148 	sbp->f_blocks = fs->fs_dsize;
1149 	UFS_LOCK(ump);
1150 	sbp->f_bfree = fs->fs_cstotal.cs_nbfree * fs->fs_frag +
1151 	    fs->fs_cstotal.cs_nffree + dbtofsb(fs, fs->fs_pendingblocks);
1152 	sbp->f_bavail = freespace(fs, fs->fs_minfree) +
1153 	    dbtofsb(fs, fs->fs_pendingblocks);
1154 	sbp->f_files =  fs->fs_ncg * fs->fs_ipg - ROOTINO;
1155 	sbp->f_ffree = fs->fs_cstotal.cs_nifree + fs->fs_pendinginodes;
1156 	UFS_UNLOCK(ump);
1157 	sbp->f_namemax = NAME_MAX;
1158 	return (0);
1159 }
1160 
1161 /*
1162  * Go through the disk queues to initiate sandbagged IO;
1163  * go through the inodes to write those that have been modified;
1164  * initiate the writing of the super block if it has been modified.
1165  *
1166  * Note: we are always called with the filesystem marked `MPBUSY'.
1167  */
1168 static int
1169 ffs_sync(mp, waitfor, td)
1170 	struct mount *mp;
1171 	int waitfor;
1172 	struct thread *td;
1173 {
1174 	struct vnode *mvp, *vp, *devvp;
1175 	struct inode *ip;
1176 	struct ufsmount *ump = VFSTOUFS(mp);
1177 	struct fs *fs;
1178 	int error, count, wait, lockreq, allerror = 0;
1179 	int suspend;
1180 	int suspended;
1181 	int secondary_writes;
1182 	int secondary_accwrites;
1183 	int softdep_deps;
1184 	int softdep_accdeps;
1185 	struct bufobj *bo;
1186 
1187 	fs = ump->um_fs;
1188 	if (fs->fs_fmod != 0 && fs->fs_ronly != 0) {		/* XXX */
1189 		printf("fs = %s\n", fs->fs_fsmnt);
1190 		panic("ffs_sync: rofs mod");
1191 	}
1192 	/*
1193 	 * Write back each (modified) inode.
1194 	 */
1195 	wait = 0;
1196 	suspend = 0;
1197 	suspended = 0;
1198 	lockreq = LK_EXCLUSIVE | LK_NOWAIT;
1199 	if (waitfor == MNT_SUSPEND) {
1200 		suspend = 1;
1201 		waitfor = MNT_WAIT;
1202 	}
1203 	if (waitfor == MNT_WAIT) {
1204 		wait = 1;
1205 		lockreq = LK_EXCLUSIVE;
1206 	}
1207 	lockreq |= LK_INTERLOCK | LK_SLEEPFAIL;
1208 	MNT_ILOCK(mp);
1209 loop:
1210 	/* Grab snapshot of secondary write counts */
1211 	secondary_writes = mp->mnt_secondary_writes;
1212 	secondary_accwrites = mp->mnt_secondary_accwrites;
1213 
1214 	/* Grab snapshot of softdep dependency counts */
1215 	MNT_IUNLOCK(mp);
1216 	softdep_get_depcounts(mp, &softdep_deps, &softdep_accdeps);
1217 	MNT_ILOCK(mp);
1218 
1219 	MNT_VNODE_FOREACH(vp, mp, mvp) {
1220 		/*
1221 		 * Depend on the mntvnode_slock to keep things stable enough
1222 		 * for a quick test.  Since there might be hundreds of
1223 		 * thousands of vnodes, we cannot afford even a subroutine
1224 		 * call unless there's a good chance that we have work to do.
1225 		 */
1226 		VI_LOCK(vp);
1227 		if (vp->v_iflag & VI_DOOMED) {
1228 			VI_UNLOCK(vp);
1229 			continue;
1230 		}
1231 		ip = VTOI(vp);
1232 		if (vp->v_type == VNON || ((ip->i_flag &
1233 		    (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE)) == 0 &&
1234 		    vp->v_bufobj.bo_dirty.bv_cnt == 0)) {
1235 			VI_UNLOCK(vp);
1236 			continue;
1237 		}
1238 		MNT_IUNLOCK(mp);
1239 		if ((error = vget(vp, lockreq, td)) != 0) {
1240 			MNT_ILOCK(mp);
1241 			if (error == ENOENT || error == ENOLCK) {
1242 				MNT_VNODE_FOREACH_ABORT_ILOCKED(mp, mvp);
1243 				goto loop;
1244 			}
1245 			continue;
1246 		}
1247 		if ((error = ffs_syncvnode(vp, waitfor)) != 0)
1248 			allerror = error;
1249 		vput(vp);
1250 		MNT_ILOCK(mp);
1251 	}
1252 	MNT_IUNLOCK(mp);
1253 	/*
1254 	 * Force stale filesystem control information to be flushed.
1255 	 */
1256 	if (waitfor == MNT_WAIT) {
1257 		if ((error = softdep_flushworklist(ump->um_mountp, &count, td)))
1258 			allerror = error;
1259 		/* Flushed work items may create new vnodes to clean */
1260 		if (allerror == 0 && count) {
1261 			MNT_ILOCK(mp);
1262 			goto loop;
1263 		}
1264 	}
1265 #ifdef QUOTA
1266 	qsync(mp);
1267 #endif
1268 	devvp = ump->um_devvp;
1269 	VI_LOCK(devvp);
1270 	bo = &devvp->v_bufobj;
1271 	if (waitfor != MNT_LAZY &&
1272 	    (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0)) {
1273 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, td);
1274 		if ((error = VOP_FSYNC(devvp, waitfor, td)) != 0)
1275 			allerror = error;
1276 		VOP_UNLOCK(devvp, 0, td);
1277 		if (allerror == 0 && waitfor == MNT_WAIT) {
1278 			MNT_ILOCK(mp);
1279 			goto loop;
1280 		}
1281 	} else if (suspend != 0) {
1282 		if (softdep_check_suspend(mp,
1283 					  devvp,
1284 					  softdep_deps,
1285 					  softdep_accdeps,
1286 					  secondary_writes,
1287 					  secondary_accwrites) != 0)
1288 			goto loop;	/* More work needed */
1289 		mtx_assert(MNT_MTX(mp), MA_OWNED);
1290 		mp->mnt_kern_flag |= MNTK_SUSPEND2 | MNTK_SUSPENDED;
1291 		MNT_IUNLOCK(mp);
1292 		suspended = 1;
1293 	} else
1294 		VI_UNLOCK(devvp);
1295 	/*
1296 	 * Write back modified superblock.
1297 	 */
1298 	if (fs->fs_fmod != 0 &&
1299 	    (error = ffs_sbupdate(ump, waitfor, suspended)) != 0)
1300 		allerror = error;
1301 	return (allerror);
1302 }
1303 
1304 int
1305 ffs_vget(mp, ino, flags, vpp)
1306 	struct mount *mp;
1307 	ino_t ino;
1308 	int flags;
1309 	struct vnode **vpp;
1310 {
1311 	struct fs *fs;
1312 	struct inode *ip;
1313 	struct ufsmount *ump;
1314 	struct buf *bp;
1315 	struct vnode *vp;
1316 	struct cdev *dev;
1317 	int error;
1318 	struct thread *td;
1319 
1320 	error = vfs_hash_get(mp, ino, flags, curthread, vpp, NULL, NULL);
1321 	if (error || *vpp != NULL)
1322 		return (error);
1323 
1324 	/*
1325 	 * We must promote to an exclusive lock for vnode creation.  This
1326 	 * can happen if lookup is passed LOCKSHARED.
1327  	 */
1328 	if ((flags & LK_TYPE_MASK) == LK_SHARED) {
1329 		flags &= ~LK_TYPE_MASK;
1330 		flags |= LK_EXCLUSIVE;
1331 	}
1332 
1333 	/*
1334 	 * We do not lock vnode creation as it is believed to be too
1335 	 * expensive for such rare case as simultaneous creation of vnode
1336 	 * for same ino by different processes. We just allow them to race
1337 	 * and check later to decide who wins. Let the race begin!
1338 	 */
1339 
1340 	ump = VFSTOUFS(mp);
1341 	dev = ump->um_dev;
1342 	fs = ump->um_fs;
1343 
1344 	/*
1345 	 * If this MALLOC() is performed after the getnewvnode()
1346 	 * it might block, leaving a vnode with a NULL v_data to be
1347 	 * found by ffs_sync() if a sync happens to fire right then,
1348 	 * which will cause a panic because ffs_sync() blindly
1349 	 * dereferences vp->v_data (as well it should).
1350 	 */
1351 	ip = uma_zalloc(uma_inode, M_WAITOK | M_ZERO);
1352 
1353 	/* Allocate a new vnode/inode. */
1354 	if (fs->fs_magic == FS_UFS1_MAGIC)
1355 		error = getnewvnode("ufs", mp, &ffs_vnodeops1, &vp);
1356 	else
1357 		error = getnewvnode("ufs", mp, &ffs_vnodeops2, &vp);
1358 	if (error) {
1359 		*vpp = NULL;
1360 		uma_zfree(uma_inode, ip);
1361 		return (error);
1362 	}
1363 	/*
1364 	 * FFS supports recursive and shared locking.
1365 	 */
1366 	vp->v_vnlock->lk_flags |= LK_CANRECURSE;
1367 	vp->v_vnlock->lk_flags &= ~LK_NOSHARE;
1368 	vp->v_data = ip;
1369 	vp->v_bufobj.bo_bsize = fs->fs_bsize;
1370 	ip->i_vnode = vp;
1371 	ip->i_ump = ump;
1372 	ip->i_fs = fs;
1373 	ip->i_dev = dev;
1374 	ip->i_number = ino;
1375 #ifdef QUOTA
1376 	{
1377 		int i;
1378 		for (i = 0; i < MAXQUOTAS; i++)
1379 			ip->i_dquot[i] = NODQUOT;
1380 	}
1381 #endif
1382 
1383 	td = curthread;
1384 	lockmgr(vp->v_vnlock, LK_EXCLUSIVE, NULL, td);
1385 	error = insmntque(vp, mp);
1386 	if (error != 0) {
1387 		uma_zfree(uma_inode, ip);
1388 		*vpp = NULL;
1389 		return (error);
1390 	}
1391 	error = vfs_hash_insert(vp, ino, flags, td, vpp, NULL, NULL);
1392 	if (error || *vpp != NULL)
1393 		return (error);
1394 
1395 	/* Read in the disk contents for the inode, copy into the inode. */
1396 	error = bread(ump->um_devvp, fsbtodb(fs, ino_to_fsba(fs, ino)),
1397 	    (int)fs->fs_bsize, NOCRED, &bp);
1398 	if (error) {
1399 		/*
1400 		 * The inode does not contain anything useful, so it would
1401 		 * be misleading to leave it on its hash chain. With mode
1402 		 * still zero, it will be unlinked and returned to the free
1403 		 * list by vput().
1404 		 */
1405 		brelse(bp);
1406 		vput(vp);
1407 		*vpp = NULL;
1408 		return (error);
1409 	}
1410 	if (ip->i_ump->um_fstype == UFS1)
1411 		ip->i_din1 = uma_zalloc(uma_ufs1, M_WAITOK);
1412 	else
1413 		ip->i_din2 = uma_zalloc(uma_ufs2, M_WAITOK);
1414 	ffs_load_inode(bp, ip, fs, ino);
1415 	if (DOINGSOFTDEP(vp))
1416 		softdep_load_inodeblock(ip);
1417 	else
1418 		ip->i_effnlink = ip->i_nlink;
1419 	bqrelse(bp);
1420 
1421 	/*
1422 	 * Initialize the vnode from the inode, check for aliases.
1423 	 * Note that the underlying vnode may have changed.
1424 	 */
1425 	if (ip->i_ump->um_fstype == UFS1)
1426 		error = ufs_vinit(mp, &ffs_fifoops1, &vp);
1427 	else
1428 		error = ufs_vinit(mp, &ffs_fifoops2, &vp);
1429 	if (error) {
1430 		vput(vp);
1431 		*vpp = NULL;
1432 		return (error);
1433 	}
1434 
1435 	/*
1436 	 * Finish inode initialization.
1437 	 */
1438 
1439 	/*
1440 	 * Set up a generation number for this inode if it does not
1441 	 * already have one. This should only happen on old filesystems.
1442 	 */
1443 	if (ip->i_gen == 0) {
1444 		ip->i_gen = arc4random() / 2 + 1;
1445 		if ((vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
1446 			ip->i_flag |= IN_MODIFIED;
1447 			DIP_SET(ip, i_gen, ip->i_gen);
1448 		}
1449 	}
1450 	/*
1451 	 * Ensure that uid and gid are correct. This is a temporary
1452 	 * fix until fsck has been changed to do the update.
1453 	 */
1454 	if (fs->fs_magic == FS_UFS1_MAGIC &&		/* XXX */
1455 	    fs->fs_old_inodefmt < FS_44INODEFMT) {	/* XXX */
1456 		ip->i_uid = ip->i_din1->di_ouid;	/* XXX */
1457 		ip->i_gid = ip->i_din1->di_ogid;	/* XXX */
1458 	}						/* XXX */
1459 
1460 #ifdef MAC
1461 	if ((mp->mnt_flag & MNT_MULTILABEL) && ip->i_mode) {
1462 		/*
1463 		 * If this vnode is already allocated, and we're running
1464 		 * multi-label, attempt to perform a label association
1465 		 * from the extended attributes on the inode.
1466 		 */
1467 		error = mac_vnode_associate_extattr(mp, vp);
1468 		if (error) {
1469 			/* ufs_inactive will release ip->i_devvp ref. */
1470 			vput(vp);
1471 			*vpp = NULL;
1472 			return (error);
1473 		}
1474 	}
1475 #endif
1476 
1477 	*vpp = vp;
1478 	return (0);
1479 }
1480 
1481 /*
1482  * File handle to vnode
1483  *
1484  * Have to be really careful about stale file handles:
1485  * - check that the inode number is valid
1486  * - call ffs_vget() to get the locked inode
1487  * - check for an unallocated inode (i_mode == 0)
1488  * - check that the given client host has export rights and return
1489  *   those rights via. exflagsp and credanonp
1490  */
1491 static int
1492 ffs_fhtovp(mp, fhp, vpp)
1493 	struct mount *mp;
1494 	struct fid *fhp;
1495 	struct vnode **vpp;
1496 {
1497 	struct ufid *ufhp;
1498 	struct fs *fs;
1499 
1500 	ufhp = (struct ufid *)fhp;
1501 	fs = VFSTOUFS(mp)->um_fs;
1502 	if (ufhp->ufid_ino < ROOTINO ||
1503 	    ufhp->ufid_ino >= fs->fs_ncg * fs->fs_ipg)
1504 		return (ESTALE);
1505 	return (ufs_fhtovp(mp, ufhp, vpp));
1506 }
1507 
1508 /*
1509  * Initialize the filesystem.
1510  */
1511 static int
1512 ffs_init(vfsp)
1513 	struct vfsconf *vfsp;
1514 {
1515 
1516 	softdep_initialize();
1517 	return (ufs_init(vfsp));
1518 }
1519 
1520 /*
1521  * Undo the work of ffs_init().
1522  */
1523 static int
1524 ffs_uninit(vfsp)
1525 	struct vfsconf *vfsp;
1526 {
1527 	int ret;
1528 
1529 	ret = ufs_uninit(vfsp);
1530 	softdep_uninitialize();
1531 	return (ret);
1532 }
1533 
1534 /*
1535  * Write a superblock and associated information back to disk.
1536  */
1537 int
1538 ffs_sbupdate(mp, waitfor, suspended)
1539 	struct ufsmount *mp;
1540 	int waitfor;
1541 	int suspended;
1542 {
1543 	struct fs *fs = mp->um_fs;
1544 	struct buf *sbbp;
1545 	struct buf *bp;
1546 	int blks;
1547 	void *space;
1548 	int i, size, error, allerror = 0;
1549 
1550 	if (fs->fs_ronly == 1 &&
1551 	    (mp->um_mountp->mnt_flag & (MNT_RDONLY | MNT_UPDATE)) !=
1552 	    (MNT_RDONLY | MNT_UPDATE))
1553 		panic("ffs_sbupdate: write read-only filesystem");
1554 	/*
1555 	 * We use the superblock's buf to serialize calls to ffs_sbupdate().
1556 	 */
1557 	sbbp = getblk(mp->um_devvp, btodb(fs->fs_sblockloc), (int)fs->fs_sbsize,
1558 	    0, 0, 0);
1559 	/*
1560 	 * First write back the summary information.
1561 	 */
1562 	blks = howmany(fs->fs_cssize, fs->fs_fsize);
1563 	space = fs->fs_csp;
1564 	for (i = 0; i < blks; i += fs->fs_frag) {
1565 		size = fs->fs_bsize;
1566 		if (i + fs->fs_frag > blks)
1567 			size = (blks - i) * fs->fs_fsize;
1568 		bp = getblk(mp->um_devvp, fsbtodb(fs, fs->fs_csaddr + i),
1569 		    size, 0, 0, 0);
1570 		bcopy(space, bp->b_data, (u_int)size);
1571 		space = (char *)space + size;
1572 		if (suspended)
1573 			bp->b_flags |= B_VALIDSUSPWRT;
1574 		if (waitfor != MNT_WAIT)
1575 			bawrite(bp);
1576 		else if ((error = bwrite(bp)) != 0)
1577 			allerror = error;
1578 	}
1579 	/*
1580 	 * Now write back the superblock itself. If any errors occurred
1581 	 * up to this point, then fail so that the superblock avoids
1582 	 * being written out as clean.
1583 	 */
1584 	if (allerror) {
1585 		brelse(sbbp);
1586 		return (allerror);
1587 	}
1588 	bp = sbbp;
1589 	if (fs->fs_magic == FS_UFS1_MAGIC && fs->fs_sblockloc != SBLOCK_UFS1 &&
1590 	    (fs->fs_flags & FS_FLAGS_UPDATED) == 0) {
1591 		printf("%s: correcting fs_sblockloc from %jd to %d\n",
1592 		    fs->fs_fsmnt, fs->fs_sblockloc, SBLOCK_UFS1);
1593 		fs->fs_sblockloc = SBLOCK_UFS1;
1594 	}
1595 	if (fs->fs_magic == FS_UFS2_MAGIC && fs->fs_sblockloc != SBLOCK_UFS2 &&
1596 	    (fs->fs_flags & FS_FLAGS_UPDATED) == 0) {
1597 		printf("%s: correcting fs_sblockloc from %jd to %d\n",
1598 		    fs->fs_fsmnt, fs->fs_sblockloc, SBLOCK_UFS2);
1599 		fs->fs_sblockloc = SBLOCK_UFS2;
1600 	}
1601 	fs->fs_fmod = 0;
1602 	fs->fs_time = time_second;
1603 	bcopy((caddr_t)fs, bp->b_data, (u_int)fs->fs_sbsize);
1604 	ffs_oldfscompat_write((struct fs *)bp->b_data, mp);
1605 	if (suspended)
1606 		bp->b_flags |= B_VALIDSUSPWRT;
1607 	if (waitfor != MNT_WAIT)
1608 		bawrite(bp);
1609 	else if ((error = bwrite(bp)) != 0)
1610 		allerror = error;
1611 	return (allerror);
1612 }
1613 
1614 static int
1615 ffs_extattrctl(struct mount *mp, int cmd, struct vnode *filename_vp,
1616 	int attrnamespace, const char *attrname, struct thread *td)
1617 {
1618 
1619 #ifdef UFS_EXTATTR
1620 	return (ufs_extattrctl(mp, cmd, filename_vp, attrnamespace,
1621 	    attrname, td));
1622 #else
1623 	return (vfs_stdextattrctl(mp, cmd, filename_vp, attrnamespace,
1624 	    attrname, td));
1625 #endif
1626 }
1627 
1628 static void
1629 ffs_ifree(struct ufsmount *ump, struct inode *ip)
1630 {
1631 
1632 	if (ump->um_fstype == UFS1 && ip->i_din1 != NULL)
1633 		uma_zfree(uma_ufs1, ip->i_din1);
1634 	else if (ip->i_din2 != NULL)
1635 		uma_zfree(uma_ufs2, ip->i_din2);
1636 	uma_zfree(uma_inode, ip);
1637 }
1638 
1639 static int dobkgrdwrite = 1;
1640 SYSCTL_INT(_debug, OID_AUTO, dobkgrdwrite, CTLFLAG_RW, &dobkgrdwrite, 0,
1641     "Do background writes (honoring the BV_BKGRDWRITE flag)?");
1642 
1643 /*
1644  * Complete a background write started from bwrite.
1645  */
1646 static void
1647 ffs_backgroundwritedone(struct buf *bp)
1648 {
1649 	struct bufobj *bufobj;
1650 	struct buf *origbp;
1651 
1652 	/*
1653 	 * Find the original buffer that we are writing.
1654 	 */
1655 	bufobj = bp->b_bufobj;
1656 	BO_LOCK(bufobj);
1657 	if ((origbp = gbincore(bp->b_bufobj, bp->b_lblkno)) == NULL)
1658 		panic("backgroundwritedone: lost buffer");
1659 	/* Grab an extra reference to be dropped by the bufdone() below. */
1660 	bufobj_wrefl(bufobj);
1661 	BO_UNLOCK(bufobj);
1662 	/*
1663 	 * Process dependencies then return any unfinished ones.
1664 	 */
1665 	if (!LIST_EMPTY(&bp->b_dep))
1666 		buf_complete(bp);
1667 #ifdef SOFTUPDATES
1668 	if (!LIST_EMPTY(&bp->b_dep))
1669 		softdep_move_dependencies(bp, origbp);
1670 #endif
1671 	/*
1672 	 * This buffer is marked B_NOCACHE so when it is released
1673 	 * by biodone it will be tossed.
1674 	 */
1675 	bp->b_flags |= B_NOCACHE;
1676 	bp->b_flags &= ~B_CACHE;
1677 	bufdone(bp);
1678 	BO_LOCK(bufobj);
1679 	/*
1680 	 * Clear the BV_BKGRDINPROG flag in the original buffer
1681 	 * and awaken it if it is waiting for the write to complete.
1682 	 * If BV_BKGRDINPROG is not set in the original buffer it must
1683 	 * have been released and re-instantiated - which is not legal.
1684 	 */
1685 	KASSERT((origbp->b_vflags & BV_BKGRDINPROG),
1686 	    ("backgroundwritedone: lost buffer2"));
1687 	origbp->b_vflags &= ~BV_BKGRDINPROG;
1688 	if (origbp->b_vflags & BV_BKGRDWAIT) {
1689 		origbp->b_vflags &= ~BV_BKGRDWAIT;
1690 		wakeup(&origbp->b_xflags);
1691 	}
1692 	BO_UNLOCK(bufobj);
1693 }
1694 
1695 
1696 /*
1697  * Write, release buffer on completion.  (Done by iodone
1698  * if async).  Do not bother writing anything if the buffer
1699  * is invalid.
1700  *
1701  * Note that we set B_CACHE here, indicating that buffer is
1702  * fully valid and thus cacheable.  This is true even of NFS
1703  * now so we set it generally.  This could be set either here
1704  * or in biodone() since the I/O is synchronous.  We put it
1705  * here.
1706  */
1707 static int
1708 ffs_bufwrite(struct buf *bp)
1709 {
1710 	int oldflags, s;
1711 	struct buf *newbp;
1712 
1713 	CTR3(KTR_BUF, "bufwrite(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
1714 	if (bp->b_flags & B_INVAL) {
1715 		brelse(bp);
1716 		return (0);
1717 	}
1718 
1719 	oldflags = bp->b_flags;
1720 
1721 	if (BUF_REFCNT(bp) == 0)
1722 		panic("bufwrite: buffer is not busy???");
1723 	s = splbio();
1724 	/*
1725 	 * If a background write is already in progress, delay
1726 	 * writing this block if it is asynchronous. Otherwise
1727 	 * wait for the background write to complete.
1728 	 */
1729 	BO_LOCK(bp->b_bufobj);
1730 	if (bp->b_vflags & BV_BKGRDINPROG) {
1731 		if (bp->b_flags & B_ASYNC) {
1732 			BO_UNLOCK(bp->b_bufobj);
1733 			splx(s);
1734 			bdwrite(bp);
1735 			return (0);
1736 		}
1737 		bp->b_vflags |= BV_BKGRDWAIT;
1738 		msleep(&bp->b_xflags, BO_MTX(bp->b_bufobj), PRIBIO, "bwrbg", 0);
1739 		if (bp->b_vflags & BV_BKGRDINPROG)
1740 			panic("bufwrite: still writing");
1741 	}
1742 	BO_UNLOCK(bp->b_bufobj);
1743 
1744 	/* Mark the buffer clean */
1745 	bundirty(bp);
1746 
1747 	/*
1748 	 * If this buffer is marked for background writing and we
1749 	 * do not have to wait for it, make a copy and write the
1750 	 * copy so as to leave this buffer ready for further use.
1751 	 *
1752 	 * This optimization eats a lot of memory.  If we have a page
1753 	 * or buffer shortfall we can't do it.
1754 	 */
1755 	if (dobkgrdwrite && (bp->b_xflags & BX_BKGRDWRITE) &&
1756 	    (bp->b_flags & B_ASYNC) &&
1757 	    !vm_page_count_severe() &&
1758 	    !buf_dirty_count_severe()) {
1759 		KASSERT(bp->b_iodone == NULL,
1760 		    ("bufwrite: needs chained iodone (%p)", bp->b_iodone));
1761 
1762 		/* get a new block */
1763 		newbp = geteblk(bp->b_bufsize);
1764 
1765 		/*
1766 		 * set it to be identical to the old block.  We have to
1767 		 * set b_lblkno and BKGRDMARKER before calling bgetvp()
1768 		 * to avoid confusing the splay tree and gbincore().
1769 		 */
1770 		memcpy(newbp->b_data, bp->b_data, bp->b_bufsize);
1771 		newbp->b_lblkno = bp->b_lblkno;
1772 		newbp->b_xflags |= BX_BKGRDMARKER;
1773 		BO_LOCK(bp->b_bufobj);
1774 		bp->b_vflags |= BV_BKGRDINPROG;
1775 		bgetvp(bp->b_vp, newbp);
1776 		BO_UNLOCK(bp->b_bufobj);
1777 		newbp->b_bufobj = &bp->b_vp->v_bufobj;
1778 		newbp->b_blkno = bp->b_blkno;
1779 		newbp->b_offset = bp->b_offset;
1780 		newbp->b_iodone = ffs_backgroundwritedone;
1781 		newbp->b_flags |= B_ASYNC;
1782 		newbp->b_flags &= ~B_INVAL;
1783 
1784 #ifdef SOFTUPDATES
1785 		/* move over the dependencies */
1786 		if (!LIST_EMPTY(&bp->b_dep))
1787 			softdep_move_dependencies(bp, newbp);
1788 #endif
1789 
1790 		/*
1791 		 * Initiate write on the copy, release the original to
1792 		 * the B_LOCKED queue so that it cannot go away until
1793 		 * the background write completes. If not locked it could go
1794 		 * away and then be reconstituted while it was being written.
1795 		 * If the reconstituted buffer were written, we could end up
1796 		 * with two background copies being written at the same time.
1797 		 */
1798 		bqrelse(bp);
1799 		bp = newbp;
1800 	}
1801 
1802 	/* Let the normal bufwrite do the rest for us */
1803 	return (bufwrite(bp));
1804 }
1805 
1806 
1807 static void
1808 ffs_geom_strategy(struct bufobj *bo, struct buf *bp)
1809 {
1810 	struct vnode *vp;
1811 	int error;
1812 	struct buf *tbp;
1813 
1814 	vp = bo->__bo_vnode;
1815 	if (bp->b_iocmd == BIO_WRITE) {
1816 		if ((bp->b_flags & B_VALIDSUSPWRT) == 0 &&
1817 		    bp->b_vp != NULL && bp->b_vp->v_mount != NULL &&
1818 		    (bp->b_vp->v_mount->mnt_kern_flag & MNTK_SUSPENDED) != 0)
1819 			panic("ffs_geom_strategy: bad I/O");
1820 		bp->b_flags &= ~B_VALIDSUSPWRT;
1821 		if ((vp->v_vflag & VV_COPYONWRITE) &&
1822 		    vp->v_rdev->si_snapdata != NULL) {
1823 			if ((bp->b_flags & B_CLUSTER) != 0) {
1824 				runningbufwakeup(bp);
1825 				TAILQ_FOREACH(tbp, &bp->b_cluster.cluster_head,
1826 					      b_cluster.cluster_entry) {
1827 					error = ffs_copyonwrite(vp, tbp);
1828 					if (error != 0 &&
1829 					    error != EOPNOTSUPP) {
1830 						bp->b_error = error;
1831 						bp->b_ioflags |= BIO_ERROR;
1832 						bufdone(bp);
1833 						return;
1834 					}
1835 				}
1836 				bp->b_runningbufspace = bp->b_bufsize;
1837 				atomic_add_int(&runningbufspace,
1838 					       bp->b_runningbufspace);
1839 			} else {
1840 				error = ffs_copyonwrite(vp, bp);
1841 				if (error != 0 && error != EOPNOTSUPP) {
1842 					bp->b_error = error;
1843 					bp->b_ioflags |= BIO_ERROR;
1844 					bufdone(bp);
1845 					return;
1846 				}
1847 			}
1848 		}
1849 #ifdef SOFTUPDATES
1850 		if ((bp->b_flags & B_CLUSTER) != 0) {
1851 			TAILQ_FOREACH(tbp, &bp->b_cluster.cluster_head,
1852 				      b_cluster.cluster_entry) {
1853 				if (!LIST_EMPTY(&tbp->b_dep))
1854 					buf_start(tbp);
1855 			}
1856 		} else {
1857 			if (!LIST_EMPTY(&bp->b_dep))
1858 				buf_start(bp);
1859 		}
1860 
1861 #endif
1862 	}
1863 	g_vfs_strategy(bo, bp);
1864 }
1865