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coda_vfsops.c revision 1.18
      1 /*	$NetBSD: coda_vfsops.c,v 1.18 2002/09/06 13:18:43 gehenna Exp $	*/
      2 
      3 /*
      4  *
      5  *             Coda: an Experimental Distributed File System
      6  *                              Release 3.1
      7  *
      8  *           Copyright (c) 1987-1998 Carnegie Mellon University
      9  *                          All Rights Reserved
     10  *
     11  * Permission  to  use, copy, modify and distribute this software and its
     12  * documentation is hereby granted,  provided  that  both  the  copyright
     13  * notice  and  this  permission  notice  appear  in  all  copies  of the
     14  * software, derivative works or  modified  versions,  and  any  portions
     15  * thereof, and that both notices appear in supporting documentation, and
     16  * that credit is given to Carnegie Mellon University  in  all  documents
     17  * and publicity pertaining to direct or indirect use of this code or its
     18  * derivatives.
     19  *
     20  * CODA IS AN EXPERIMENTAL SOFTWARE SYSTEM AND IS  KNOWN  TO  HAVE  BUGS,
     21  * SOME  OF  WHICH MAY HAVE SERIOUS CONSEQUENCES.  CARNEGIE MELLON ALLOWS
     22  * FREE USE OF THIS SOFTWARE IN ITS "AS IS" CONDITION.   CARNEGIE  MELLON
     23  * DISCLAIMS  ANY  LIABILITY  OF  ANY  KIND  FOR  ANY  DAMAGES WHATSOEVER
     24  * RESULTING DIRECTLY OR INDIRECTLY FROM THE USE OF THIS SOFTWARE  OR  OF
     25  * ANY DERIVATIVE WORK.
     26  *
     27  * Carnegie  Mellon  encourages  users  of  this  software  to return any
     28  * improvements or extensions that  they  make,  and  to  grant  Carnegie
     29  * Mellon the rights to redistribute these changes without encumbrance.
     30  *
     31  * 	@(#) cfs/coda_vfsops.c,v 1.1.1.1 1998/08/29 21:26:45 rvb Exp $
     32  */
     33 
     34 /*
     35  * Mach Operating System
     36  * Copyright (c) 1989 Carnegie-Mellon University
     37  * All rights reserved.  The CMU software License Agreement specifies
     38  * the terms and conditions for use and redistribution.
     39  */
     40 
     41 /*
     42  * This code was written for the Coda file system at Carnegie Mellon
     43  * University.  Contributers include David Steere, James Kistler, and
     44  * M. Satyanarayanan.
     45  */
     46 
     47 #include <sys/cdefs.h>
     48 __KERNEL_RCSID(0, "$NetBSD: coda_vfsops.c,v 1.18 2002/09/06 13:18:43 gehenna Exp $");
     49 
     50 #ifdef	_LKM
     51 #define	NVCODA 4
     52 #else
     53 #include <vcoda.h>
     54 #endif
     55 
     56 #include <sys/param.h>
     57 #include <sys/systm.h>
     58 #include <sys/malloc.h>
     59 #include <sys/conf.h>
     60 #include <sys/namei.h>
     61 #include <sys/mount.h>
     62 #include <sys/proc.h>
     63 #include <sys/select.h>
     64 
     65 #include <coda/coda.h>
     66 #include <coda/cnode.h>
     67 #include <coda/coda_vfsops.h>
     68 #include <coda/coda_venus.h>
     69 #include <coda/coda_subr.h>
     70 #include <coda/coda_opstats.h>
     71 /* for VN_RDEV */
     72 #include <miscfs/specfs/specdev.h>
     73 
     74 int codadebug = 0;
     75 
     76 int coda_vfsop_print_entry = 0;
     77 #define ENTRY if(coda_vfsop_print_entry) myprintf(("Entered %s\n",__func__))
     78 
     79 struct vnode *coda_ctlvp;
     80 struct coda_mntinfo coda_mnttbl[NVCODA]; /* indexed by minor device number */
     81 
     82 /* structure to keep statistics of internally generated/satisfied calls */
     83 
     84 struct coda_op_stats coda_vfsopstats[CODA_VFSOPS_SIZE];
     85 
     86 #define MARK_ENTRY(op) (coda_vfsopstats[op].entries++)
     87 #define MARK_INT_SAT(op) (coda_vfsopstats[op].sat_intrn++)
     88 #define MARK_INT_FAIL(op) (coda_vfsopstats[op].unsat_intrn++)
     89 #define MRAK_INT_GEN(op) (coda_vfsopstats[op].gen_intrn++)
     90 
     91 extern int coda_nc_initialized;     /* Set if cache has been initialized */
     92 extern const struct cdevsw vcoda_cdevsw;
     93 extern const struct vnodeopv_desc coda_vnodeop_opv_desc;
     94 
     95 const struct vnodeopv_desc * const coda_vnodeopv_descs[] = {
     96 	&coda_vnodeop_opv_desc,
     97 	NULL,
     98 };
     99 
    100 struct vfsops coda_vfsops = {
    101     MOUNT_CODA,
    102     coda_mount,
    103     coda_start,
    104     coda_unmount,
    105     coda_root,
    106     coda_quotactl,
    107     coda_nb_statfs,
    108     coda_sync,
    109     coda_vget,
    110     (int (*) (struct mount *, struct fid *, struct vnode ** ))
    111 	eopnotsupp,
    112     (int (*) (struct vnode *, struct fid *)) eopnotsupp,
    113     coda_init,
    114     NULL,
    115     coda_done,
    116     coda_sysctl,
    117     (int (*)(void)) eopnotsupp,
    118     (int (*)(struct mount *, struct mbuf *, int *, struct ucred **))
    119 	eopnotsupp,
    120     coda_vnodeopv_descs,
    121     0
    122 };
    123 
    124 int
    125 coda_vfsopstats_init(void)
    126 {
    127 	int i;
    128 
    129 	for (i=0;i<CODA_VFSOPS_SIZE;i++) {
    130 		coda_vfsopstats[i].opcode = i;
    131 		coda_vfsopstats[i].entries = 0;
    132 		coda_vfsopstats[i].sat_intrn = 0;
    133 		coda_vfsopstats[i].unsat_intrn = 0;
    134 		coda_vfsopstats[i].gen_intrn = 0;
    135 	}
    136 
    137 	return 0;
    138 }
    139 
    140 /*
    141  * cfs mount vfsop
    142  * Set up mount info record and attach it to vfs struct.
    143  */
    144 /*ARGSUSED*/
    145 int
    146 coda_mount(vfsp, path, data, ndp, p)
    147     struct mount *vfsp;		/* Allocated and initialized by mount(2) */
    148     const char *path;		/* path covered: ignored by the fs-layer */
    149     void *data;			/* Need to define a data type for this in netbsd? */
    150     struct nameidata *ndp;	/* Clobber this to lookup the device name */
    151     struct proc *p;		/* The ever-famous proc pointer */
    152 {
    153     struct vnode *dvp;
    154     struct cnode *cp;
    155     dev_t dev;
    156     struct coda_mntinfo *mi;
    157     struct vnode *rootvp;
    158     const struct cdevsw *cdev;
    159     ViceFid rootfid;
    160     ViceFid ctlfid;
    161     int error;
    162 
    163     ENTRY;
    164 
    165     coda_vfsopstats_init();
    166     coda_vnodeopstats_init();
    167 
    168     MARK_ENTRY(CODA_MOUNT_STATS);
    169     if (CODA_MOUNTED(vfsp)) {
    170 	MARK_INT_FAIL(CODA_MOUNT_STATS);
    171 	return(EBUSY);
    172     }
    173 
    174     /* Validate mount device.  Similar to getmdev(). */
    175 
    176     NDINIT(ndp, LOOKUP, FOLLOW, UIO_USERSPACE, data, p);
    177     error = namei(ndp);
    178     dvp = ndp->ni_vp;
    179 
    180     if (error) {
    181 	MARK_INT_FAIL(CODA_MOUNT_STATS);
    182 	return (error);
    183     }
    184     if (dvp->v_type != VCHR) {
    185 	MARK_INT_FAIL(CODA_MOUNT_STATS);
    186 	vrele(dvp);
    187 	return(ENXIO);
    188     }
    189     dev = dvp->v_specinfo->si_rdev;
    190     vrele(dvp);
    191     cdev = cdevsw_lookup(dev);
    192     if (cdev == NULL) {
    193 	MARK_INT_FAIL(CODA_MOUNT_STATS);
    194 	return(ENXIO);
    195     }
    196 
    197     /*
    198      * See if the device table matches our expectations.
    199      */
    200     if (cdev != &vcoda_cdevsw)
    201     {
    202 	MARK_INT_FAIL(CODA_MOUNT_STATS);
    203 	return(ENXIO);
    204     }
    205 
    206     if (minor(dev) >= NVCODA || minor(dev) < 0) {
    207 	MARK_INT_FAIL(CODA_MOUNT_STATS);
    208 	return(ENXIO);
    209     }
    210 
    211     /*
    212      * Initialize the mount record and link it to the vfs struct
    213      */
    214     mi = &coda_mnttbl[minor(dev)];
    215 
    216     if (!VC_OPEN(&mi->mi_vcomm)) {
    217 	MARK_INT_FAIL(CODA_MOUNT_STATS);
    218 	return(ENODEV);
    219     }
    220 
    221     /* No initialization (here) of mi_vcomm! */
    222     vfsp->mnt_data = mi;
    223     vfsp->mnt_stat.f_fsid.val[0] = 0;
    224     vfsp->mnt_stat.f_fsid.val[1] = makefstype(MOUNT_CODA);
    225     mi->mi_vfsp = vfsp;
    226 
    227     /*
    228      * Make a root vnode to placate the Vnode interface, but don't
    229      * actually make the CODA_ROOT call to venus until the first call
    230      * to coda_root in case a server is down while venus is starting.
    231      */
    232     rootfid.Volume = 0;
    233     rootfid.Vnode = 0;
    234     rootfid.Unique = 0;
    235     cp = make_coda_node(&rootfid, vfsp, VDIR);
    236     rootvp = CTOV(cp);
    237     rootvp->v_flag |= VROOT;
    238 
    239     ctlfid.Volume = CTL_VOL;
    240     ctlfid.Vnode = CTL_VNO;
    241     ctlfid.Unique = CTL_UNI;
    242 /*  cp = make_coda_node(&ctlfid, vfsp, VCHR);
    243     The above code seems to cause a loop in the cnode links.
    244     I don't totally understand when it happens, it is caught
    245     when closing down the system.
    246  */
    247     cp = make_coda_node(&ctlfid, 0, VCHR);
    248 
    249     coda_ctlvp = CTOV(cp);
    250 
    251     /* Add vfs and rootvp to chain of vfs hanging off mntinfo */
    252     mi->mi_vfsp = vfsp;
    253     mi->mi_rootvp = rootvp;
    254 
    255     /* set filesystem block size */
    256     vfsp->mnt_stat.f_bsize = 8192;	    /* XXX -JJK */
    257 
    258     /* error is currently guaranteed to be zero, but in case some
    259        code changes... */
    260     CODADEBUG(1,
    261 	     myprintf(("coda_mount returned %d\n",error)););
    262     if (error)
    263 	MARK_INT_FAIL(CODA_MOUNT_STATS);
    264     else
    265 	MARK_INT_SAT(CODA_MOUNT_STATS);
    266 
    267     return(error);
    268 }
    269 
    270 int
    271 coda_start(vfsp, flags, p)
    272     struct mount *vfsp;
    273     int flags;
    274     struct proc *p;
    275 {
    276     ENTRY;
    277     return (0);
    278 }
    279 
    280 int
    281 coda_unmount(vfsp, mntflags, p)
    282     struct mount *vfsp;
    283     int mntflags;
    284     struct proc *p;
    285 {
    286     struct coda_mntinfo *mi = vftomi(vfsp);
    287     int active, error = 0;
    288 
    289     ENTRY;
    290     MARK_ENTRY(CODA_UMOUNT_STATS);
    291     if (!CODA_MOUNTED(vfsp)) {
    292 	MARK_INT_FAIL(CODA_UMOUNT_STATS);
    293 	return(EINVAL);
    294     }
    295 
    296     if (mi->mi_vfsp == vfsp) {	/* We found the victim */
    297 	if (!IS_UNMOUNTING(VTOC(mi->mi_rootvp)))
    298 	    return (EBUSY); 	/* Venus is still running */
    299 
    300 #ifdef	DEBUG
    301 	printf("coda_unmount: ROOT: vp %p, cp %p\n", mi->mi_rootvp, VTOC(mi->mi_rootvp));
    302 #endif
    303 	vrele(mi->mi_rootvp);
    304 
    305 	active = coda_kill(vfsp, NOT_DOWNCALL);
    306 	mi->mi_rootvp->v_flag &= ~VROOT;
    307 	error = vflush(mi->mi_vfsp, NULLVP, FORCECLOSE);
    308 	printf("coda_unmount: active = %d, vflush active %d\n", active, error);
    309 	error = 0;
    310 
    311 	/* I'm going to take this out to allow lookups to go through. I'm
    312 	 * not sure it's important anyway. -- DCS 2/2/94
    313 	 */
    314 	/* vfsp->VFS_DATA = NULL; */
    315 
    316 	/* No more vfsp's to hold onto */
    317 	mi->mi_vfsp = NULL;
    318 	mi->mi_rootvp = NULL;
    319 
    320 	if (error)
    321 	    MARK_INT_FAIL(CODA_UMOUNT_STATS);
    322 	else
    323 	    MARK_INT_SAT(CODA_UMOUNT_STATS);
    324 
    325 	return(error);
    326     }
    327     return (EINVAL);
    328 }
    329 
    330 /*
    331  * find root of cfs
    332  */
    333 int
    334 coda_root(vfsp, vpp)
    335 	struct mount *vfsp;
    336 	struct vnode **vpp;
    337 {
    338     struct coda_mntinfo *mi = vftomi(vfsp);
    339     struct vnode **result;
    340     int error;
    341     struct proc *p = curproc;    /* XXX - bnoble */
    342     ViceFid VFid;
    343 
    344     ENTRY;
    345     MARK_ENTRY(CODA_ROOT_STATS);
    346     result = NULL;
    347 
    348     if (vfsp == mi->mi_vfsp) {
    349 	if ((VTOC(mi->mi_rootvp)->c_fid.Volume != 0) ||
    350 	    (VTOC(mi->mi_rootvp)->c_fid.Vnode != 0) ||
    351 	    (VTOC(mi->mi_rootvp)->c_fid.Unique != 0))
    352 	    { /* Found valid root. */
    353 		*vpp = mi->mi_rootvp;
    354 		/* On Mach, this is vref.  On NetBSD, VOP_LOCK */
    355 		vref(*vpp);
    356 		vn_lock(*vpp, LK_EXCLUSIVE);
    357 		MARK_INT_SAT(CODA_ROOT_STATS);
    358 		return(0);
    359 	    }
    360     }
    361 
    362     error = venus_root(vftomi(vfsp), p->p_cred->pc_ucred, p, &VFid);
    363 
    364     if (!error) {
    365 	/*
    366 	 * Save the new rootfid in the cnode, and rehash the cnode into the
    367 	 * cnode hash with the new fid key.
    368 	 */
    369 	coda_unsave(VTOC(mi->mi_rootvp));
    370 	VTOC(mi->mi_rootvp)->c_fid = VFid;
    371 	coda_save(VTOC(mi->mi_rootvp));
    372 
    373 	*vpp = mi->mi_rootvp;
    374 	vref(*vpp);
    375 	vn_lock(*vpp, LK_EXCLUSIVE);
    376 	MARK_INT_SAT(CODA_ROOT_STATS);
    377 	goto exit;
    378     } else if (error == ENODEV || error == EINTR) {
    379 	/* Gross hack here! */
    380 	/*
    381 	 * If Venus fails to respond to the CODA_ROOT call, coda_call returns
    382 	 * ENODEV. Return the uninitialized root vnode to allow vfs
    383 	 * operations such as unmount to continue. Without this hack,
    384 	 * there is no way to do an unmount if Venus dies before a
    385 	 * successful CODA_ROOT call is done. All vnode operations
    386 	 * will fail.
    387 	 */
    388 	*vpp = mi->mi_rootvp;
    389 	vref(*vpp);
    390 	vn_lock(*vpp, LK_EXCLUSIVE);
    391 	MARK_INT_FAIL(CODA_ROOT_STATS);
    392 	error = 0;
    393 	goto exit;
    394     } else {
    395 	CODADEBUG( CODA_ROOT, myprintf(("error %d in CODA_ROOT\n", error)); );
    396 	MARK_INT_FAIL(CODA_ROOT_STATS);
    397 
    398 	goto exit;
    399     }
    400  exit:
    401     return(error);
    402 }
    403 
    404 int
    405 coda_quotactl(vfsp, cmd, uid, arg, p)
    406     struct mount *vfsp;
    407     int cmd;
    408     uid_t uid;
    409     caddr_t arg;
    410     struct proc *p;
    411 {
    412     ENTRY;
    413     return (EOPNOTSUPP);
    414 }
    415 
    416 /*
    417  * Get file system statistics.
    418  */
    419 int
    420 coda_nb_statfs(vfsp, sbp, p)
    421     struct mount *vfsp;
    422     struct statfs *sbp;
    423     struct proc *p;
    424 {
    425     struct coda_statfs fsstat;
    426     int error;
    427 
    428     ENTRY;
    429     MARK_ENTRY(CODA_STATFS_STATS);
    430     if (!CODA_MOUNTED(vfsp)) {
    431 /*	MARK_INT_FAIL(CODA_STATFS_STATS); */
    432 	return(EINVAL);
    433     }
    434 
    435     memset(sbp, 0, sizeof(struct statfs));
    436     /* XXX - what to do about f_flags, others? --bnoble */
    437     /* Below This is what AFS does
    438     	#define NB_SFS_SIZ 0x895440
    439      */
    440     /* Note: Normal fs's have a bsize of 0x400 == 1024 */
    441 
    442     error = venus_statfs(vftomi(vfsp), p->p_cred->pc_ucred, p, &fsstat);
    443 
    444     if (!error) {
    445 	sbp->f_type = 0;
    446 	sbp->f_bsize = 8192; /* XXX */
    447 	sbp->f_iosize = 8192; /* XXX */
    448 	sbp->f_blocks = fsstat.f_blocks;
    449 	sbp->f_bfree  = fsstat.f_bfree;
    450 	sbp->f_bavail = fsstat.f_bavail;
    451 	sbp->f_files  = fsstat.f_files;
    452 	sbp->f_ffree  = fsstat.f_ffree;
    453         bcopy((caddr_t)&(vfsp->mnt_stat.f_fsid),
    454 	      (caddr_t)&(sbp->f_fsid), sizeof (fsid_t));
    455         strncpy(sbp->f_fstypename, MOUNT_CODA, MFSNAMELEN-1);
    456         strcpy(sbp->f_mntonname, "/coda");
    457         strcpy(sbp->f_mntfromname, "CODA");
    458     }
    459 
    460     MARK_INT_SAT(CODA_STATFS_STATS);
    461     return(error);
    462 }
    463 
    464 /*
    465  * Flush any pending I/O.
    466  */
    467 int
    468 coda_sync(vfsp, waitfor, cred, p)
    469     struct mount *vfsp;
    470     int    waitfor;
    471     struct ucred *cred;
    472     struct proc *p;
    473 {
    474     ENTRY;
    475     MARK_ENTRY(CODA_SYNC_STATS);
    476     MARK_INT_SAT(CODA_SYNC_STATS);
    477     return(0);
    478 }
    479 
    480 int
    481 coda_vget(vfsp, ino, vpp)
    482     struct mount *vfsp;
    483     ino_t ino;
    484     struct vnode **vpp;
    485 {
    486     ENTRY;
    487     return (EOPNOTSUPP);
    488 }
    489 
    490 /*
    491  * fhtovp is now what vget used to be in 4.3-derived systems.  For
    492  * some silly reason, vget is now keyed by a 32 bit ino_t, rather than
    493  * a type-specific fid.
    494  */
    495 int
    496 coda_fhtovp(vfsp, fhp, nam, vpp, exflagsp, creadanonp)
    497     struct mount *vfsp;
    498     struct fid *fhp;
    499     struct mbuf *nam;
    500     struct vnode **vpp;
    501     int *exflagsp;
    502     struct ucred **creadanonp;
    503 {
    504     struct cfid *cfid = (struct cfid *)fhp;
    505     struct cnode *cp = 0;
    506     int error;
    507     struct proc *p = curproc; /* XXX -mach */
    508     ViceFid VFid;
    509     int vtype;
    510 
    511     ENTRY;
    512 
    513     MARK_ENTRY(CODA_VGET_STATS);
    514     /* Check for vget of control object. */
    515     if (IS_CTL_FID(&cfid->cfid_fid)) {
    516 	*vpp = coda_ctlvp;
    517 	vref(coda_ctlvp);
    518 	MARK_INT_SAT(CODA_VGET_STATS);
    519 	return(0);
    520     }
    521 
    522     error = venus_fhtovp(vftomi(vfsp), &cfid->cfid_fid, p->p_cred->pc_ucred, p, &VFid, &vtype);
    523 
    524     if (error) {
    525 	CODADEBUG(CODA_VGET, myprintf(("vget error %d\n",error));)
    526 	    *vpp = (struct vnode *)0;
    527     } else {
    528 	CODADEBUG(CODA_VGET,
    529 		 myprintf(("vget: vol %lx vno %lx uni %lx type %d result %d\n",
    530 			VFid.Volume, VFid.Vnode, VFid.Unique, vtype, error)); )
    531 
    532 	cp = make_coda_node(&VFid, vfsp, vtype);
    533 	*vpp = CTOV(cp);
    534     }
    535     return(error);
    536 }
    537 
    538 int
    539 coda_vptofh(vnp, fidp)
    540     struct vnode *vnp;
    541     struct fid   *fidp;
    542 {
    543     ENTRY;
    544     return (EOPNOTSUPP);
    545 }
    546 
    547 void
    548 coda_init(void)
    549 {
    550     ENTRY;
    551 }
    552 
    553 void
    554 coda_done(void)
    555 {
    556     ENTRY;
    557 }
    558 
    559 int
    560 coda_sysctl(name, namelen, oldp, oldlp, newp, newl, p)
    561 	int *name;
    562 	u_int namelen;
    563 	void *oldp;
    564 	size_t *oldlp;
    565 	void *newp;
    566 	size_t newl;
    567 	struct proc *p;
    568 {
    569 
    570 	/* all sysctl names at this level are terminal */
    571 	if (namelen != 1)
    572 		return (ENOTDIR);		/* overloaded */
    573 
    574 	switch (name[0]) {
    575 /*
    576 	case FFS_CLUSTERREAD:
    577 		return (sysctl_int(oldp, oldlp, newp, newl, &doclusterread));
    578  */
    579 	default:
    580 		return (EOPNOTSUPP);
    581 	}
    582 	/* NOTREACHED */
    583 }
    584 
    585 /*
    586  * To allow for greater ease of use, some vnodes may be orphaned when
    587  * Venus dies.  Certain operations should still be allowed to go
    588  * through, but without propagating ophan-ness.  So this function will
    589  * get a new vnode for the file from the current run of Venus.  */
    590 
    591 int
    592 getNewVnode(vpp)
    593      struct vnode **vpp;
    594 {
    595     struct cfid cfid;
    596     struct coda_mntinfo *mi = vftomi((*vpp)->v_mount);
    597 
    598     ENTRY;
    599 
    600     cfid.cfid_len = (short)sizeof(ViceFid);
    601     cfid.cfid_fid = VTOC(*vpp)->c_fid;	/* Structure assignment. */
    602     /* XXX ? */
    603 
    604     /* We're guessing that if set, the 1st element on the list is a
    605      * valid vnode to use. If not, return ENODEV as venus is dead.
    606      */
    607     if (mi->mi_vfsp == NULL)
    608 	return ENODEV;
    609 
    610     return coda_fhtovp(mi->mi_vfsp, (struct fid*)&cfid, NULL, vpp,
    611 		      NULL, NULL);
    612 }
    613 
    614 #include <ufs/ufs/quota.h>
    615 #include <ufs/ufs/ufsmount.h>
    616 /* get the mount structure corresponding to a given device.  Assume
    617  * device corresponds to a UFS. Return NULL if no device is found.
    618  */
    619 struct mount *devtomp(dev)
    620     dev_t dev;
    621 {
    622     struct mount *mp, *nmp;
    623 
    624     for (mp = mountlist.cqh_first; mp != (void*)&mountlist; mp = nmp) {
    625 	nmp = mp->mnt_list.cqe_next;
    626 	if ((!strcmp(mp->mnt_op->vfs_name, MOUNT_UFS)) &&
    627 	    ((VFSTOUFS(mp))->um_dev == (dev_t) dev)) {
    628 	    /* mount corresponds to UFS and the device matches one we want */
    629 	    return(mp);
    630 	}
    631     }
    632     /* mount structure wasn't found */
    633     return(NULL);
    634 }
    635