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lfs_vfsops.c revision 1.44
      1 /*	$NetBSD: lfs_vfsops.c,v 1.44 1999/11/15 18:49:14 fvdl Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1999 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Konrad E. Schroder <perseant (at) hhhh.org>.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *      This product includes software developed by the NetBSD
     21  *      Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 /*-
     39  * Copyright (c) 1989, 1991, 1993, 1994
     40  *	The Regents of the University of California.  All rights reserved.
     41  *
     42  * Redistribution and use in source and binary forms, with or without
     43  * modification, are permitted provided that the following conditions
     44  * are met:
     45  * 1. Redistributions of source code must retain the above copyright
     46  *    notice, this list of conditions and the following disclaimer.
     47  * 2. Redistributions in binary form must reproduce the above copyright
     48  *    notice, this list of conditions and the following disclaimer in the
     49  *    documentation and/or other materials provided with the distribution.
     50  * 3. All advertising materials mentioning features or use of this software
     51  *    must display the following acknowledgement:
     52  *	This product includes software developed by the University of
     53  *	California, Berkeley and its contributors.
     54  * 4. Neither the name of the University nor the names of its contributors
     55  *    may be used to endorse or promote products derived from this software
     56  *    without specific prior written permission.
     57  *
     58  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     68  * SUCH DAMAGE.
     69  *
     70  *	@(#)lfs_vfsops.c	8.20 (Berkeley) 6/10/95
     71  */
     72 
     73 #if defined(_KERNEL) && !defined(_LKM)
     74 #include "opt_quota.h"
     75 #endif
     76 
     77 #include <sys/param.h>
     78 #include <sys/systm.h>
     79 #include <sys/namei.h>
     80 #include <sys/proc.h>
     81 #include <sys/kernel.h>
     82 #include <sys/vnode.h>
     83 #include <sys/mount.h>
     84 #include <sys/buf.h>
     85 #include <sys/device.h>
     86 #include <sys/mbuf.h>
     87 #include <sys/file.h>
     88 #include <sys/disklabel.h>
     89 #include <sys/ioctl.h>
     90 #include <sys/errno.h>
     91 #include <sys/malloc.h>
     92 #include <sys/pool.h>
     93 #include <sys/socket.h>
     94 #include <vm/vm.h>
     95 #include <sys/sysctl.h>
     96 
     97 #include <miscfs/specfs/specdev.h>
     98 
     99 #include <ufs/ufs/quota.h>
    100 #include <ufs/ufs/inode.h>
    101 #include <ufs/ufs/ufsmount.h>
    102 #include <ufs/ufs/ufs_extern.h>
    103 
    104 #include <ufs/lfs/lfs.h>
    105 #include <ufs/lfs/lfs_extern.h>
    106 
    107 int lfs_mountfs __P((struct vnode *, struct mount *, struct proc *));
    108 
    109 extern struct vnodeopv_desc lfs_vnodeop_opv_desc;
    110 extern struct vnodeopv_desc lfs_specop_opv_desc;
    111 extern struct vnodeopv_desc lfs_fifoop_opv_desc;
    112 
    113 struct vnodeopv_desc *lfs_vnodeopv_descs[] = {
    114 	&lfs_vnodeop_opv_desc,
    115 	&lfs_specop_opv_desc,
    116 	&lfs_fifoop_opv_desc,
    117 	NULL,
    118 };
    119 
    120 struct vfsops lfs_vfsops = {
    121 	MOUNT_LFS,
    122 	lfs_mount,
    123 	ufs_start,
    124 	lfs_unmount,
    125 	ufs_root,
    126 	ufs_quotactl,
    127 	lfs_statfs,
    128 	lfs_sync,
    129 	lfs_vget,
    130 	lfs_fhtovp,
    131 	lfs_vptofh,
    132 	lfs_init,
    133 	lfs_sysctl,
    134 	lfs_mountroot,
    135 	ufs_check_export,
    136 	lfs_vnodeopv_descs,
    137 };
    138 
    139 struct pool lfs_inode_pool;
    140 
    141 /*
    142  * Initialize the filesystem, most work done by ufs_init.
    143  */
    144 void
    145 lfs_init()
    146 {
    147 	ufs_init();
    148 
    149 	/*
    150 	 * XXX Same structure as FFS inodes?  Should we share a common pool?
    151 	 */
    152 	pool_init(&lfs_inode_pool, sizeof(struct inode), 0, 0, 0,
    153 		  "lfsinopl", 0, pool_page_alloc_nointr, pool_page_free_nointr,
    154 		  M_LFSNODE);
    155 }
    156 
    157 /*
    158  * Called by main() when ufs is going to be mounted as root.
    159  */
    160 int
    161 lfs_mountroot()
    162 {
    163 	extern struct vnode *rootvp;
    164 	struct mount *mp;
    165 	struct proc *p = curproc;	/* XXX */
    166 	int error;
    167 
    168 	if (root_device->dv_class != DV_DISK)
    169 		return (ENODEV);
    170 
    171 	if (rootdev == NODEV)
    172 	  	return (ENODEV);
    173 	/*
    174 	 * Get vnodes for swapdev and rootdev.
    175 	 */
    176 	if ((error = bdevvp(rootdev, &rootvp))) {
    177 		printf("lfs_mountroot: can't setup bdevvp's");
    178 		return (error);
    179 	}
    180 	if ((error = vfs_rootmountalloc(MOUNT_LFS, "root_device", &mp))) {
    181 		vrele(rootvp);
    182 		return (error);
    183 	}
    184 	if ((error = lfs_mountfs(rootvp, mp, p))) {
    185 		mp->mnt_op->vfs_refcount--;
    186 		vfs_unbusy(mp);
    187 		free(mp, M_MOUNT);
    188 		vrele(rootvp);
    189 		return (error);
    190 	}
    191 	simple_lock(&mountlist_slock);
    192 	CIRCLEQ_INSERT_TAIL(&mountlist, mp, mnt_list);
    193 	simple_unlock(&mountlist_slock);
    194 	(void)lfs_statfs(mp, &mp->mnt_stat, p);
    195 	vfs_unbusy(mp);
    196 	return (0);
    197 }
    198 
    199 /*
    200  * VFS Operations.
    201  *
    202  * mount system call
    203  */
    204 int
    205 lfs_mount(mp, path, data, ndp, p)
    206 	register struct mount *mp;
    207 	const char *path;
    208 	void *data;
    209 	struct nameidata *ndp;
    210 	struct proc *p;
    211 {
    212 	struct vnode *devvp;
    213 	struct ufs_args args;
    214 	struct ufsmount *ump = NULL;
    215 	register struct lfs *fs = NULL;				/* LFS */
    216 	size_t size;
    217 	int error;
    218 	mode_t accessmode;
    219 
    220 	error = copyin(data, (caddr_t)&args, sizeof (struct ufs_args));
    221 	if (error)
    222 		return (error);
    223 
    224 #if 0
    225 	/* Until LFS can do NFS right.		XXX */
    226 	if (args.export.ex_flags & MNT_EXPORTED)
    227 		return (EINVAL);
    228 #endif
    229 
    230 	/*
    231 	 * If updating, check whether changing from read-only to
    232 	 * read/write; if there is no device name, that's all we do.
    233 	 */
    234 	if (mp->mnt_flag & MNT_UPDATE) {
    235 		ump = VFSTOUFS(mp);
    236 		fs = ump->um_lfs;
    237 		if (fs->lfs_ronly && (mp->mnt_flag & MNT_WANTRDWR)) {
    238 			/*
    239 			 * If upgrade to read-write by non-root, then verify
    240 			 * that user has necessary permissions on the device.
    241 			 */
    242 			if (p->p_ucred->cr_uid != 0) {
    243 				vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
    244 				error = VOP_ACCESS(ump->um_devvp, VREAD|VWRITE,
    245 						   p->p_ucred, p);
    246 				VOP_UNLOCK(ump->um_devvp, 0);
    247 				if (error)
    248 					return (error);
    249 			}
    250 			fs->lfs_ronly = 0;
    251 		}
    252 		if (args.fspec == 0) {
    253 			/*
    254 			 * Process export requests.
    255 			 */
    256 			return (vfs_export(mp, &ump->um_export, &args.export));
    257 		}
    258 	}
    259 	/*
    260 	 * Not an update, or updating the name: look up the name
    261 	 * and verify that it refers to a sensible block device.
    262 	 */
    263 	NDINIT(ndp, LOOKUP, FOLLOW, UIO_USERSPACE, args.fspec, p);
    264 	if ((error = namei(ndp)) != 0)
    265 		return (error);
    266 	devvp = ndp->ni_vp;
    267 	if (devvp->v_type != VBLK) {
    268 		vrele(devvp);
    269 		return (ENOTBLK);
    270 	}
    271 	if (major(devvp->v_rdev) >= nblkdev) {
    272 		vrele(devvp);
    273 		return (ENXIO);
    274 	}
    275 	/*
    276 	 * If mount by non-root, then verify that user has necessary
    277 	 * permissions on the device.
    278 	 */
    279 	if (p->p_ucred->cr_uid != 0) {
    280 		accessmode = VREAD;
    281 		if ((mp->mnt_flag & MNT_RDONLY) == 0)
    282 			accessmode |= VWRITE;
    283 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
    284 		error = VOP_ACCESS(devvp, accessmode, p->p_ucred, p);
    285 		if (error) {
    286 			vput(devvp);
    287 			return (error);
    288 		}
    289 		VOP_UNLOCK(devvp, 0);
    290 	}
    291 	if ((mp->mnt_flag & MNT_UPDATE) == 0)
    292 		error = lfs_mountfs(devvp, mp, p);		/* LFS */
    293 	else {
    294 		if (devvp != ump->um_devvp)
    295 			error = EINVAL;	/* needs translation */
    296 		else
    297 			vrele(devvp);
    298 	}
    299 	if (error) {
    300 		vrele(devvp);
    301 		return (error);
    302 	}
    303 	ump = VFSTOUFS(mp);
    304 	fs = ump->um_lfs;					/* LFS */
    305 	(void)copyinstr(path, fs->lfs_fsmnt, sizeof(fs->lfs_fsmnt) - 1, &size);
    306 	bzero(fs->lfs_fsmnt + size, sizeof(fs->lfs_fsmnt) - size);
    307 	bcopy(fs->lfs_fsmnt, mp->mnt_stat.f_mntonname, MNAMELEN);
    308 	(void) copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
    309 			 &size);
    310 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
    311 	return (0);
    312 }
    313 
    314 /*
    315  * Common code for mount and mountroot
    316  * LFS specific
    317  */
    318 int
    319 lfs_mountfs(devvp, mp, p)
    320 	register struct vnode *devvp;
    321 	struct mount *mp;
    322 	struct proc *p;
    323 {
    324 	extern struct vnode *rootvp;
    325 	struct dlfs *dfs, *adfs;
    326 	register struct lfs *fs;
    327 	register struct ufsmount *ump;
    328 	struct vnode *vp;
    329 	struct buf *bp, *abp;
    330 	struct partinfo dpart;
    331 	dev_t dev;
    332 	int error, i, ronly, size;
    333 	struct ucred *cred;
    334         SEGUSE *sup;
    335 
    336 	cred = p ? p->p_ucred : NOCRED;
    337 	/*
    338 	 * Disallow multiple mounts of the same device.
    339 	 * Disallow mounting of a device that is currently in use
    340 	 * (except for root, which might share swap device for miniroot).
    341 	 * Flush out any old buffers remaining from a previous use.
    342 	 */
    343 	if ((error = vfs_mountedon(devvp)) != 0)
    344 		return (error);
    345 	if (vcount(devvp) > 1 && devvp != rootvp)
    346 		return (EBUSY);
    347 	if ((error = vinvalbuf(devvp, V_SAVE, cred, p, 0, 0)) != 0)
    348 		return (error);
    349 
    350 	ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
    351 	error = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, FSCRED, p);
    352 	if (error)
    353 		return (error);
    354 	if (VOP_IOCTL(devvp, DIOCGPART, (caddr_t)&dpart, FREAD, cred, p) != 0)
    355 		size = DEV_BSIZE;
    356 	else
    357 		size = dpart.disklab->d_secsize;
    358 
    359 	/* Don't free random space on error. */
    360 	bp = NULL;
    361 	ump = NULL;
    362 
    363 	/* Read in the superblock. */
    364 	error = bread(devvp, LFS_LABELPAD / size, LFS_SBPAD, cred, &bp);
    365 	if (error)
    366 		goto out;
    367 	dfs = (struct dlfs *)bp->b_data;
    368 
    369 	/*
    370 	 * Check the second superblock to see which is newer; then mount
    371 	 * using the older of the two.  This is necessary to ensure that
    372 	 * the filesystem is valid if it was not unmounted cleanly.
    373 	 */
    374 	error = bread(devvp, dfs->dlfs_sboffs[1], LFS_SBPAD, cred, &abp);
    375 	if (error)
    376 		goto out;
    377 	adfs = (struct dlfs *)abp->b_data;
    378 
    379 	if (adfs->dlfs_tstamp < dfs->dlfs_tstamp) /* XXX KS - 1s resolution? */
    380 		dfs = adfs;
    381 
    382 	/* Check the basics. */
    383 	if (dfs->dlfs_magic != LFS_MAGIC || dfs->dlfs_bsize > MAXBSIZE ||
    384 	    dfs->dlfs_version > LFS_VERSION ||
    385 	    dfs->dlfs_bsize < sizeof(struct dlfs)) {
    386 		error = EINVAL;		/* XXX needs translation */
    387 		goto out;
    388 	}
    389 
    390 	/* Allocate the mount structure, copy the superblock into it. */
    391 	fs = malloc(sizeof(struct lfs), M_UFSMNT, M_WAITOK);
    392 	memcpy(&fs->lfs_dlfs, dfs, sizeof(struct dlfs));
    393 	ump = malloc(sizeof *ump, M_UFSMNT, M_WAITOK);
    394 	memset((caddr_t)ump, 0, sizeof *ump);
    395 	ump->um_lfs = fs;
    396 	if (sizeof(struct lfs) < LFS_SBPAD)			/* XXX why? */
    397 		bp->b_flags |= B_INVAL;
    398 	brelse(bp);
    399 	bp = NULL;
    400 	brelse(abp);
    401 	abp = NULL;
    402 
    403 	/* Set up the I/O information */
    404 	fs->lfs_iocount = 0;
    405 	fs->lfs_diropwait = 0;
    406 	fs->lfs_activesb = 0;
    407 #ifdef LFS_CANNOT_ROLLFW
    408 	fs->lfs_sbactive = NULL;
    409 #endif
    410 #ifdef LFS_TRACK_IOS
    411 	for (i=0;i<LFS_THROTTLE;i++)
    412 		fs->lfs_pending[i] = LFS_UNUSED_DADDR;
    413 #endif
    414 
    415 	/* Set up the ifile and lock aflags */
    416 	fs->lfs_doifile = 0;
    417 	fs->lfs_writer = 0;
    418 	fs->lfs_dirops = 0;
    419 	fs->lfs_seglock = 0;
    420 
    421 	/* Set the file system readonly/modify bits. */
    422 	fs->lfs_ronly = ronly;
    423 	if (ronly == 0)
    424 		fs->lfs_fmod = 1;
    425 
    426 	/* Initialize the mount structure. */
    427 	dev = devvp->v_rdev;
    428 	mp->mnt_data = (qaddr_t)ump;
    429 	mp->mnt_stat.f_fsid.val[0] = (long)dev;
    430 	mp->mnt_stat.f_fsid.val[1] = makefstype(MOUNT_LFS);
    431 	mp->mnt_maxsymlinklen = fs->lfs_maxsymlinklen;
    432 	mp->mnt_flag |= MNT_LOCAL;
    433 	ump->um_flags = 0;
    434 	ump->um_mountp = mp;
    435 	ump->um_dev = dev;
    436 	ump->um_devvp = devvp;
    437 	ump->um_bptrtodb = 0;
    438 	ump->um_seqinc = 1 << fs->lfs_fsbtodb;
    439 	ump->um_nindir = fs->lfs_nindir;
    440 	for (i = 0; i < MAXQUOTAS; i++)
    441 		ump->um_quotas[i] = NULLVP;
    442 	devvp->v_specmountpoint = mp;
    443 
    444 	/*
    445 	 * We use the ifile vnode for almost every operation.  Instead of
    446 	 * retrieving it from the hash table each time we retrieve it here,
    447 	 * artificially increment the reference count and keep a pointer
    448 	 * to it in the incore copy of the superblock.
    449 	 */
    450 	if ((error = VFS_VGET(mp, LFS_IFILE_INUM, &vp)) != 0)
    451 		goto out;
    452 	fs->lfs_ivnode = vp;
    453 	VREF(vp);
    454 	vput(vp);
    455 
    456 	/*
    457 	 * Mark the current segment as ACTIVE, since we're going to
    458 	 * be writing to it.
    459 	 */
    460         LFS_SEGENTRY(sup, fs, datosn(fs, fs->lfs_offset), bp);
    461         sup->su_flags |= SEGUSE_DIRTY | SEGUSE_ACTIVE;
    462         (void) VOP_BWRITE(bp);
    463 
    464 	return (0);
    465 out:
    466 	if (bp)
    467 		brelse(bp);
    468 	if (abp)
    469 		brelse(abp);
    470 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
    471 	(void)VOP_CLOSE(devvp, ronly ? FREAD : FREAD|FWRITE, cred, p);
    472 	VOP_UNLOCK(devvp, 0);
    473 	if (ump) {
    474 		free(ump->um_lfs, M_UFSMNT);
    475 		free(ump, M_UFSMNT);
    476 		mp->mnt_data = (qaddr_t)0;
    477 	}
    478 	return (error);
    479 }
    480 
    481 /*
    482  * unmount system call
    483  */
    484 int
    485 lfs_unmount(mp, mntflags, p)
    486 	struct mount *mp;
    487 	int mntflags;
    488 	struct proc *p;
    489 {
    490 	register struct ufsmount *ump;
    491 	register struct lfs *fs;
    492 	int error, flags, ronly;
    493 	extern int lfs_allclean_wakeup;
    494 
    495 	flags = 0;
    496 	if (mntflags & MNT_FORCE)
    497 		flags |= FORCECLOSE;
    498 
    499 	ump = VFSTOUFS(mp);
    500 	fs = ump->um_lfs;
    501 #ifdef QUOTA
    502 	if (mp->mnt_flag & MNT_QUOTA) {
    503 		int i;
    504 		error = vflush(mp, fs->lfs_ivnode, SKIPSYSTEM|flags);
    505 		if (error)
    506 			return (error);
    507 		for (i = 0; i < MAXQUOTAS; i++) {
    508 			if (ump->um_quotas[i] == NULLVP)
    509 				continue;
    510 			quotaoff(p, mp, i);
    511 		}
    512 		/*
    513 		 * Here we fall through to vflush again to ensure
    514 		 * that we have gotten rid of all the system vnodes.
    515 		 */
    516 	}
    517 #endif
    518 	if ((error = vflush(mp, fs->lfs_ivnode, flags)) != 0)
    519 		return (error);
    520 	fs->lfs_clean = 1;
    521 	if ((error = VFS_SYNC(mp, 1, p->p_ucred, p)) != 0)
    522 		return (error);
    523 	if (fs->lfs_ivnode->v_dirtyblkhd.lh_first)
    524 		panic("lfs_unmount: still dirty blocks on ifile vnode\n");
    525 	vrele(fs->lfs_ivnode);
    526 	vgone(fs->lfs_ivnode);
    527 
    528 	ronly = !fs->lfs_ronly;
    529 	if (ump->um_devvp->v_type != VBAD)
    530 		ump->um_devvp->v_specmountpoint = NULL;
    531 	vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
    532 	error = VOP_CLOSE(ump->um_devvp,
    533 	    ronly ? FREAD : FREAD|FWRITE, NOCRED, p);
    534 	vput(ump->um_devvp);
    535 
    536 	/* XXX KS - wake up the cleaner so it can die */
    537 	wakeup(&fs->lfs_nextseg);
    538 	wakeup(&lfs_allclean_wakeup);
    539 
    540 	free(fs, M_UFSMNT);
    541 	free(ump, M_UFSMNT);
    542 	mp->mnt_data = (qaddr_t)0;
    543 	mp->mnt_flag &= ~MNT_LOCAL;
    544 	return (error);
    545 }
    546 
    547 /*
    548  * Get file system statistics.
    549  */
    550 int
    551 lfs_statfs(mp, sbp, p)
    552 	struct mount *mp;
    553 	register struct statfs *sbp;
    554 	struct proc *p;
    555 {
    556 	register struct lfs *fs;
    557 	register struct ufsmount *ump;
    558 
    559 	ump = VFSTOUFS(mp);
    560 	fs = ump->um_lfs;
    561 	if (fs->lfs_magic != LFS_MAGIC)
    562 		panic("lfs_statfs: magic");
    563 	sbp->f_type = 0;
    564 	sbp->f_bsize = fs->lfs_fsize;
    565 	sbp->f_iosize = fs->lfs_bsize;
    566 	sbp->f_blocks = dbtofrags(fs, fs->lfs_dsize);
    567 	sbp->f_bfree = dbtofrags(fs, fs->lfs_bfree);
    568 	/*
    569 	 * To compute the available space.  Subtract the minimum free
    570 	 * from the total number of blocks in the file system.	Set avail
    571 	 * to the smaller of this number and fs->lfs_bfree.
    572 	 *
    573 	 * XXX KS - is my modification below what is desired?  (This
    574 	 * will, e.g., change the report when the cleaner runs.)
    575 	 */
    576 #if 0
    577         sbp->f_bavail = (long) ((u_int64_t) fs->lfs_dsize * (u_int64_t)
    578 		(100 - fs->lfs_minfree) / (u_int64_t) 100);
    579 	sbp->f_bavail =
    580 	    sbp->f_bavail > fs->lfs_bfree ? fs->lfs_bfree : sbp->f_bavail;
    581 #else
    582 	sbp->f_bavail = (long) ((u_int64_t) fs->lfs_dsize * (u_int64_t)
    583 				(100 - fs->lfs_minfree) / (u_int64_t) 100)
    584 		- (u_int64_t)(fs->lfs_dsize - fs->lfs_bfree);
    585 #endif
    586 	sbp->f_bavail = dbtofrags(fs, sbp->f_bavail);
    587 	sbp->f_files = dbtofsb(fs,fs->lfs_bfree) * INOPB(fs);
    588 	sbp->f_ffree = sbp->f_files - fs->lfs_nfiles;
    589 	if (sbp != &mp->mnt_stat) {
    590 		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
    591 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
    592 	}
    593 	strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, MFSNAMELEN);
    594 	return (0);
    595 }
    596 
    597 /*
    598  * Go through the disk queues to initiate sandbagged IO;
    599  * go through the inodes to write those that have been modified;
    600  * initiate the writing of the super block if it has been modified.
    601  *
    602  * Note: we are always called with the filesystem marked `MPBUSY'.
    603  */
    604 int
    605 lfs_sync(mp, waitfor, cred, p)
    606 	struct mount *mp;
    607 	int waitfor;
    608 	struct ucred *cred;
    609 	struct proc *p;
    610 {
    611 	int error;
    612 	struct lfs *fs;
    613 
    614 	fs = ((struct ufsmount *)mp->mnt_data)->ufsmount_u.lfs;
    615 	while(fs->lfs_dirops)
    616 		error = tsleep(&fs->lfs_dirops, PRIBIO + 1, "lfs_dirops", 0);
    617 	fs->lfs_writer++;
    618 
    619 	/* All syncs must be checkpoints until roll-forward is implemented. */
    620 	error = lfs_segwrite(mp, SEGM_CKP | (waitfor ? SEGM_SYNC : 0));
    621 	if(--fs->lfs_writer==0)
    622 		wakeup(&fs->lfs_dirops);
    623 #ifdef QUOTA
    624 	qsync(mp);
    625 #endif
    626 	return (error);
    627 }
    628 
    629 extern struct lock ufs_hashlock;
    630 
    631 /*
    632  * Look up an LFS dinode number to find its incore vnode.  If not already
    633  * in core, read it in from the specified device.  Return the inode locked.
    634  * Detection and handling of mount points must be done by the calling routine.
    635  */
    636 int
    637 lfs_vget(mp, ino, vpp)
    638 	struct mount *mp;
    639 	ino_t ino;
    640 	struct vnode **vpp;
    641 {
    642 	register struct lfs *fs;
    643 	register struct inode *ip;
    644 	struct buf *bp;
    645 	struct ifile *ifp;
    646 	struct vnode *vp;
    647 	struct ufsmount *ump;
    648 	ufs_daddr_t daddr;
    649 	dev_t dev;
    650 	int error;
    651 #ifdef LFS_ATIME_IFILE
    652 	struct timespec ts;
    653 #endif
    654 
    655 	ump = VFSTOUFS(mp);
    656 	dev = ump->um_dev;
    657 
    658 	do {
    659 		if ((*vpp = ufs_ihashget(dev, ino, LK_EXCLUSIVE)) != NULL)
    660 			return (0);
    661 	} while (lockmgr(&ufs_hashlock, LK_EXCLUSIVE|LK_SLEEPFAIL, 0));
    662 
    663 	/* Translate the inode number to a disk address. */
    664 	fs = ump->um_lfs;
    665 	if (ino == LFS_IFILE_INUM)
    666 		daddr = fs->lfs_idaddr;
    667 	else {
    668 		LFS_IENTRY(ifp, fs, ino, bp);
    669 		daddr = ifp->if_daddr;
    670 #ifdef LFS_ATIME_IFILE
    671 		ts = ifp->if_atime; /* structure copy */
    672 #endif
    673 		brelse(bp);
    674 		if (daddr == LFS_UNUSED_DADDR) {
    675 			lockmgr(&ufs_hashlock, LK_RELEASE, 0);
    676 			return (ENOENT);
    677 		}
    678 	}
    679 
    680 	/* Allocate new vnode/inode. */
    681 	if ((error = lfs_vcreate(mp, ino, &vp)) != 0) {
    682 		*vpp = NULL;
    683 		lockmgr(&ufs_hashlock, LK_RELEASE, 0);
    684 		return (error);
    685 	}
    686 
    687 	/*
    688 	 * Put it onto its hash chain and lock it so that other requests for
    689 	 * this inode will block if they arrive while we are sleeping waiting
    690 	 * for old data structures to be purged or for the contents of the
    691 	 * disk portion of this inode to be read.
    692 	 */
    693 	ip = VTOI(vp);
    694 	ufs_ihashins(ip);
    695 	lockmgr(&ufs_hashlock, LK_RELEASE, 0);
    696 
    697 	/*
    698 	 * XXX
    699 	 * This may not need to be here, logically it should go down with
    700 	 * the i_devvp initialization.
    701 	 * Ask Kirk.
    702 	 */
    703 	ip->i_lfs = ump->um_lfs;
    704 
    705 	/* Read in the disk contents for the inode, copy into the inode. */
    706 	error = bread(ump->um_devvp, daddr, (int)fs->lfs_bsize, NOCRED, &bp);
    707 	if (error) {
    708 		/*
    709 		 * The inode does not contain anything useful, so it would
    710 		 * be misleading to leave it on its hash chain. With mode
    711 		 * still zero, it will be unlinked and returned to the free
    712 		 * list by vput().
    713 		 */
    714 		vput(vp);
    715 		brelse(bp);
    716 		*vpp = NULL;
    717 		return (error);
    718 	}
    719 	ip->i_din.ffs_din = *lfs_ifind(fs, ino, (struct dinode *)bp->b_data);
    720 #ifdef LFS_ATIME_IFILE
    721 	ip->i_ffs_atime = ts.tv_sec;
    722 	ip->i_ffs_atimensec = ts.tv_nsec;
    723 #endif
    724 	brelse(bp);
    725 
    726 	/*
    727 	 * Initialize the vnode from the inode, check for aliases.  In all
    728 	 * cases re-init ip, the underlying vnode/inode may have changed.
    729 	 */
    730 	error = ufs_vinit(mp, lfs_specop_p, lfs_fifoop_p, &vp);
    731 	if (error) {
    732 		vput(vp);
    733 		*vpp = NULL;
    734 		return (error);
    735 	}
    736 	if(vp->v_type == VNON) {
    737 		printf("lfs_vget: ino %d is type VNON! (ifmt %o)\n", ip->i_number, (ip->i_ffs_mode&IFMT)>>12);
    738 #ifdef DDB
    739 		Debugger();
    740 #endif
    741 	}
    742 	/*
    743 	 * Finish inode initialization now that aliasing has been resolved.
    744 	 */
    745 	ip->i_devvp = ump->um_devvp;
    746 	VREF(ip->i_devvp);
    747 	*vpp = vp;
    748 
    749 	return (0);
    750 }
    751 
    752 /*
    753  * File handle to vnode
    754  *
    755  * Have to be really careful about stale file handles:
    756  * - check that the inode number is valid
    757  * - call lfs_vget() to get the locked inode
    758  * - check for an unallocated inode (i_mode == 0)
    759  *
    760  * XXX
    761  * use ifile to see if inode is allocated instead of reading off disk
    762  * what is the relationship between my generational number and the NFS
    763  * generational number.
    764  */
    765 int
    766 lfs_fhtovp(mp, fhp, vpp)
    767 	register struct mount *mp;
    768 	struct fid *fhp;
    769 	struct vnode **vpp;
    770 {
    771 	register struct ufid *ufhp;
    772 
    773 	ufhp = (struct ufid *)fhp;
    774 	if (ufhp->ufid_ino < ROOTINO)
    775 		return (ESTALE);
    776 	return (ufs_fhtovp(mp, ufhp, vpp));
    777 }
    778 
    779 /*
    780  * Vnode pointer to File handle
    781  */
    782 /* ARGSUSED */
    783 int
    784 lfs_vptofh(vp, fhp)
    785 	struct vnode *vp;
    786 	struct fid *fhp;
    787 {
    788 	register struct inode *ip;
    789 	register struct ufid *ufhp;
    790 
    791 	ip = VTOI(vp);
    792 	ufhp = (struct ufid *)fhp;
    793 	ufhp->ufid_len = sizeof(struct ufid);
    794 	ufhp->ufid_ino = ip->i_number;
    795 	ufhp->ufid_gen = ip->i_ffs_gen;
    796 	return (0);
    797 }
    798 
    799 int
    800 lfs_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
    801 	int *name;
    802 	u_int namelen;
    803 	void *oldp;
    804 	size_t *oldlenp;
    805 	void *newp;
    806 	size_t newlen;
    807 	struct proc *p;
    808 {
    809 	extern int lfs_writeindir, lfs_dostats, lfs_clean_vnhead;
    810 	extern struct lfs_stats lfs_stats;
    811 	int error;
    812 
    813 	/* all sysctl names at this level are terminal */
    814 	if (namelen != 1)
    815 		return (ENOTDIR);
    816 
    817 	switch (name[0]) {
    818 	case LFS_WRITEINDIR:
    819 		return (sysctl_int(oldp, oldlenp, newp, newlen,
    820 				   &lfs_writeindir));
    821 	case LFS_CLEAN_VNHEAD:
    822 		return (sysctl_int(oldp, oldlenp, newp, newlen,
    823 				   &lfs_clean_vnhead));
    824 	case LFS_DOSTATS:
    825 		if((error = sysctl_int(oldp, oldlenp, newp, newlen,
    826 				       &lfs_dostats)))
    827 			return error;
    828 		if(lfs_dostats == 0)
    829 			memset(&lfs_stats,0,sizeof(lfs_stats));
    830 		return 0;
    831 	case LFS_STATS:
    832 		return (sysctl_rdstruct(oldp, oldlenp, newp,
    833 					&lfs_stats, sizeof(lfs_stats)));
    834 	default:
    835 		return (EOPNOTSUPP);
    836 	}
    837 	/* NOTREACHED */
    838 }
    839