[unix-history] / usr / src / sys / ufs / ffs / ffs_inode.c

/*	ffs_inode.c	4.6	81/10/11	*/

#include "../h/param.h"
#include "../h/systm.h"
#include "../h/mount.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/inode.h"
#include "../h/ino.h"
#include "../h/filsys.h"
#include "../h/conf.h"
#include "../h/buf.h"
#include "../h/inline.h"

#define	INOHSZ	63
#define	INOHASH(dev,ino)	(((dev)+(ino))%INOHSZ)
short	inohash[INOHSZ];
short	ifreel;

/*
 * Initialize hash links for inodes
 * and build inode free list.
 */
ihinit()
{
	register int i;
	register struct inode *ip = inode;

	ifreel = 0;
	for (i = 0; i < ninode-1; i++, ip++)
		ip->i_hlink = i+1;
	ip->i_hlink = -1;
	for (i = 0; i < INOHSZ; i++)
		inohash[i] = -1;
}

/*
 * Find an inode if it is incore.
 * This is the equivalent, for inodes,
 * of ``incore'' in bio.c or ``pfind'' in subr.c.
 */
struct inode *
ifind(dev, ino)
dev_t dev;
ino_t ino;
{
	register struct inode *ip;

	for (ip = &inode[inohash[INOHASH(dev,ino)]]; ip != &inode[-1];
	    ip = &inode[ip->i_hlink])
		if (ino==ip->i_number && dev==ip->i_dev)
			return (ip);
	return ((struct inode *)0);
}

/*
 * Look up an inode by device,inumber.
 * If it is in core (in the inode structure),
 * honor the locking protocol.
 * If it is not in core, read it in from the
 * specified device.
 * If the inode is mounted on, perform
 * the indicated indirection.
 * In all cases, a pointer to a locked
 * inode structure is returned.
 *
 * panic: no imt -- if the mounted file
 *	system is not in the mount table.
 *	"cannot happen"
 */
struct inode *
iget(dev, ino)
dev_t dev;
ino_t ino;
{
	register struct inode *ip;
	register struct mount *mp;
	register struct buf *bp;
	register struct dinode *dp;
	register int slot;

loop:
	slot = INOHASH(dev, ino);
	ip = &inode[inohash[slot]];
	while (ip != &inode[-1]) {
		if(ino == ip->i_number && dev == ip->i_dev) {
			if((ip->i_flag&ILOCK) != 0) {
				ip->i_flag |= IWANT;
				sleep((caddr_t)ip, PINOD);
				goto loop;
			}
			if((ip->i_flag&IMOUNT) != 0) {
				for(mp = &mount[0]; mp < &mount[NMOUNT]; mp++)
				if(mp->m_inodp == ip) {
					dev = mp->m_dev;
					ino = ROOTINO;
					goto loop;
				}
				panic("no imt");
			}
			ip->i_count++;
			ip->i_flag |= ILOCK;
			return(ip);
		}
		ip = &inode[ip->i_hlink];
	}
	if(ifreel < 0) {
		tablefull("inode");
		u.u_error = ENFILE;
		return(NULL);
	}
	ip = &inode[ifreel];
	ifreel = ip->i_hlink;
	ip->i_hlink = inohash[slot];
	inohash[slot] = ip - inode;
	ip->i_dev = dev;
	ip->i_number = ino;
	ip->i_flag = ILOCK;
	ip->i_count++;
	ip->i_un.i_lastr = 0;
	bp = bread(dev, itod(ino));
	/*
	 * Check I/O errors
	 */
	if((bp->b_flags&B_ERROR) != 0) {
		brelse(bp);
		iput(ip);
		return(NULL);
	}
	dp = bp->b_un.b_dino;
	dp += itoo(ino);
	iexpand(ip, dp);
	brelse(bp);
	return(ip);
}

iexpand(ip, dp)
register struct inode *ip;
register struct dinode *dp;
{
	register char *p1, *p2;
	register int i;

	ip->i_mode = dp->di_mode;
	ip->i_nlink = dp->di_nlink;
	ip->i_uid = dp->di_uid;
	ip->i_gid = dp->di_gid;
	ip->i_size = dp->di_size;
	p1 = (char *)ip->i_un.i_addr;
	p2 = (char *)dp->di_addr;
	for(i=0; i<NADDR; i++) {
		*p1++ = *p2++;
		*p1++ = *p2++;
		*p1++ = *p2++;
		*p1++ = 0;
	}
}

/*
 * Decrement reference count of
 * an inode structure.
 * On the last reference,
 * write the inode out and if necessary,
 * truncate and deallocate the file.
 */
iput(ip)
register struct inode *ip;
{
	register int i, x;
	register struct inode *jp;

	if(ip->i_count == 1) {
		ip->i_flag |= ILOCK;
		if(ip->i_nlink <= 0) {
			itrunc(ip);
			ip->i_mode = 0;
			ip->i_flag |= IUPD|ICHG;
			ifree(ip->i_dev, ip->i_number);
		}
		IUPDAT(ip, &time, &time, 0);
		prele(ip);
		i = INOHASH(ip->i_dev, ip->i_number);
		x = ip - inode;
		if (inohash[i] == x) {
			inohash[i] = ip->i_hlink;
		} else {
			for (jp = &inode[inohash[i]]; jp != &inode[-1];
			    jp = &inode[jp->i_hlink])
				if (jp->i_hlink == x) {
					jp->i_hlink = ip->i_hlink;
					goto done;
				}
			panic("iput");
		}
done:
		ip->i_hlink = ifreel;
		ifreel = x;
		ip->i_flag = 0;
		ip->i_number = 0;
	} else
		prele(ip);
	ip->i_count--;
}

/*
 * Check accessed and update flags on
 * an inode structure.
 * If any is on, update the inode
 * with the current time.
 * If waitfor is given, then must insure
 * i/o order so wait for write to complete.
 */
iupdat(ip, ta, tm, waitfor)
register struct inode *ip;
time_t *ta, *tm;
int waitfor;
{
	register struct buf *bp;
	struct dinode *dp;
	register char *p1, *p2;
	register int i;

	if((ip->i_flag&(IUPD|IACC|ICHG)) != 0) {
		if(getfs(ip->i_dev)->s_ronly)
			return;
		bp = bread(ip->i_dev, itod(ip->i_number));
		if (bp->b_flags & B_ERROR) {
			brelse(bp);
			return;
		}
		dp = bp->b_un.b_dino;
		dp += itoo(ip->i_number);
		dp->di_mode = ip->i_mode;
		dp->di_nlink = ip->i_nlink;
		dp->di_uid = ip->i_uid;
		dp->di_gid = ip->i_gid;
		dp->di_size = ip->i_size;
		p1 = (char *)dp->di_addr;
		p2 = (char *)ip->i_un.i_addr;
		for(i=0; i<NADDR; i++) {
			*p1++ = *p2++;
			*p1++ = *p2++;
			*p1++ = *p2++;
			if(*p2++ != 0)
				printf("iaddress > 2^24\n");
		}
		if(ip->i_flag&IACC)
			dp->di_atime = *ta;
		if(ip->i_flag&IUPD)
			dp->di_mtime = *tm;
		if(ip->i_flag&ICHG)
			dp->di_ctime = time;
		ip->i_flag &= ~(IUPD|IACC|ICHG);
		if (waitfor)
			bwrite(bp);
		else
			bdwrite(bp);
	}
}

/*
 * Free all the disk blocks associated
 * with the specified inode structure.
 * The blocks of the file are removed
 * in reverse order. This FILO
 * algorithm will tend to maintain
 * a contiguous free list much longer
 * than FIFO.
 */
itrunc(ip)
register struct inode *ip;
{
	register i;
	dev_t dev;
	daddr_t bn;
	struct inode itmp;

	if (ip->i_vfdcnt)
		panic("itrunc");
	i = ip->i_mode & IFMT;
	if (i!=IFREG && i!=IFDIR)
		return;

	/*
	 * Clean inode on disk before freeing blocks
	 * to insure no duplicates if system crashes.
	 */
	itmp = *ip;
	itmp.i_size = 0;
	for (i = 0; i < NADDR; i++)
		itmp.i_un.i_addr[i] = 0;
	itmp.i_flag |= ICHG|IUPD;
	iupdat(&itmp, &time, &time, 1);
	ip->i_flag &= ~(IUPD|IACC|ICHG);

	/*
	 * Now return blocks to free list... if machine
	 * crashes, they will be harmless MISSING blocks.
	 */
	dev = ip->i_dev;
	for(i=NADDR-1; i>=0; i--) {
		bn = ip->i_un.i_addr[i];
		if(bn == (daddr_t)0)
			continue;
		ip->i_un.i_addr[i] = (daddr_t)0;
		switch(i) {

		default:
			free(dev, bn);
			break;

		case NADDR-3:
			tloop(dev, bn, 0, 0);
			break;

		case NADDR-2:
			tloop(dev, bn, 1, 0);
			break;

		case NADDR-1:
			tloop(dev, bn, 1, 1);
		}
	}
	ip->i_size = 0;
	/*
	 * Inode was written and flags updated above.
	 * No need to modify flags here.
	 */
}

tloop(dev, bn, f1, f2)
dev_t dev;
daddr_t bn;
{
	register i;
	register struct buf *bp;
	register daddr_t *bap;
	daddr_t nb;

	bp = NULL;
	for(i=NINDIR-1; i>=0; i--) {
		if(bp == NULL) {
			bp = bread(dev, bn);
			if (bp->b_flags & B_ERROR) {
				brelse(bp);
				return;
			}
			bap = bp->b_un.b_daddr;
		}
		nb = bap[i];
		if(nb == (daddr_t)0)
			continue;
		if(f1) {
			brelse(bp);
			bp = NULL;
			tloop(dev, nb, f2, 0);
		} else
			free(dev, nb);
	}
	if(bp != NULL)
		brelse(bp);
	free(dev, bn);
}

/*
 * Make a new file.
 */
struct inode *
maknode(mode)
{
	register struct inode *ip;

	ip = ialloc(u.u_pdir->i_dev);
	if(ip == NULL) {
		iput(u.u_pdir);
		return(NULL);
	}
	ip->i_flag |= IACC|IUPD|ICHG;
	if((mode&IFMT) == 0)
		mode |= IFREG;
	ip->i_mode = mode & ~u.u_cmask;
	ip->i_nlink = 1;
	ip->i_uid = u.u_uid;
	ip->i_gid = u.u_gid;

	/*
	 * Make sure inode goes to disk before directory entry.
	 */
	iupdat(ip, &time, &time, 1);

	wdir(ip);
	return(ip);
}

/*
 * Write a directory entry with
 * parameters left as side effects
 * to a call to namei.
 */
wdir(ip)
struct inode *ip;
{

	u.u_dent.d_ino = ip->i_number;
	bcopy((caddr_t)u.u_dbuf, (caddr_t)u.u_dent.d_name, DIRSIZ);
	u.u_count = sizeof(struct direct);
	u.u_segflg = 1;
	u.u_base = (caddr_t)&u.u_dent;
	writei(u.u_pdir);
	iput(u.u_pdir);
}

#ifdef plock
#undef plock
#endif
#ifdef prele
#undef prele
#endif
/*
 * Lock an inode (should be called ilock).
 * If its already locked,
 * set the WANT bit and sleep.
 */
plock(ip)
register struct inode *ip;
{

	while(ip->i_flag&ILOCK) {
		ip->i_flag |= IWANT;
		sleep((caddr_t)ip, PINOD);
	}
	ip->i_flag |= ILOCK;
}

/*
 * Unlock an inode.
 * If WANT bit is on,
 * wakeup.
 */
prele(ip)
register struct inode *ip;
{

	ip->i_flag &= ~ILOCK;
	if(ip->i_flag&IWANT) {
		ip->i_flag &= ~IWANT;
		wakeup((caddr_t)ip);
	}
}
Commit	Line	Data
231ed58b	1	/* ffs_inode.c 4.6 81/10/11 */
5d5124a1 BJ	2
	3	#include "../h/param.h"
	4	#include "../h/systm.h"
	5	#include "../h/mount.h"
	6	#include "../h/dir.h"
	7	#include "../h/user.h"
	8	#include "../h/inode.h"
	9	#include "../h/ino.h"
	10	#include "../h/filsys.h"
	11	#include "../h/conf.h"
	12	#include "../h/buf.h"
	13	#include "../h/inline.h"
	14
	15	#define INOHSZ 63
	16	#define INOHASH(dev,ino) (((dev)+(ino))%INOHSZ)
	17	short inohash[INOHSZ];
	18	short ifreel;
	19
	20	/*
	21	* Initialize hash links for inodes
	22	* and build inode free list.
	23	*/
	24	ihinit()
	25	{
	26	register int i;
75105cf0	27	register struct inode *ip = inode;
5d5124a1 BJ	28
5d5124a1 BJ	29	ifreel = 0;
75105cf0 BJ	30	for (i = 0; i < ninode-1; i++, ip++)
	31	ip->i_hlink = i+1;
	32	ip->i_hlink = -1;
5d5124a1 BJ	33	for (i = 0; i < INOHSZ; i++)
	34	inohash[i] = -1;
	35	}
	36
	37	/*
	38	* Find an inode if it is incore.
	39	* This is the equivalent, for inodes,
	40	* of ``incore'' in bio.c or ``pfind'' in subr.c.
	41	*/
	42	struct inode *
	43	ifind(dev, ino)
	44	dev_t dev;
	45	ino_t ino;
	46	{
	47	register struct inode *ip;
	48
	49	for (ip = &inode[inohash[INOHASH(dev,ino)]]; ip != &inode[-1];
	50	ip = &inode[ip->i_hlink])
	51	if (ino==ip->i_number && dev==ip->i_dev)
	52	return (ip);
	53	return ((struct inode *)0);
	54	}
	55
	56	/*
	57	* Look up an inode by device,inumber.
	58	* If it is in core (in the inode structure),
	59	* honor the locking protocol.
	60	* If it is not in core, read it in from the
	61	* specified device.
	62	* If the inode is mounted on, perform
	63	* the indicated indirection.
	64	* In all cases, a pointer to a locked
	65	* inode structure is returned.
	66	*
5d5124a1 BJ	67	* panic: no imt -- if the mounted file
	68	* system is not in the mount table.
	69	* "cannot happen"
	70	*/
	71	struct inode *
	72	iget(dev, ino)
	73	dev_t dev;
	74	ino_t ino;
	75	{
	76	register struct inode *ip;
	77	register struct mount *mp;
	78	register struct buf *bp;
	79	register struct dinode *dp;
	80	register int slot;
	81
	82	loop:
	83	slot = INOHASH(dev, ino);
	84	ip = &inode[inohash[slot]];
	85	while (ip != &inode[-1]) {
	86	if(ino == ip->i_number && dev == ip->i_dev) {
	87	if((ip->i_flag&ILOCK) != 0) {
	88	ip->i_flag \|= IWANT;
	89	sleep((caddr_t)ip, PINOD);
	90	goto loop;
	91	}
	92	if((ip->i_flag&IMOUNT) != 0) {
	93	for(mp = &mount[0]; mp < &mount[NMOUNT]; mp++)
	94	if(mp->m_inodp == ip) {
	95	dev = mp->m_dev;
	96	ino = ROOTINO;
	97	goto loop;
	98	}
	99	panic("no imt");
	100	}
	101	ip->i_count++;
	102	ip->i_flag \|= ILOCK;
	103	return(ip);
	104	}
	105	ip = &inode[ip->i_hlink];
	106	}
	107	if(ifreel < 0) {
945fbb1b	108	tablefull("inode");
5d5124a1 BJ	109	u.u_error = ENFILE;
	110	return(NULL);
	111	}
	112	ip = &inode[ifreel];
	113	ifreel = ip->i_hlink;
	114	ip->i_hlink = inohash[slot];
	115	inohash[slot] = ip - inode;
	116	ip->i_dev = dev;
	117	ip->i_number = ino;
	118	ip->i_flag = ILOCK;
	119	ip->i_count++;
	120	ip->i_un.i_lastr = 0;
	121	bp = bread(dev, itod(ino));
	122	/*
	123	* Check I/O errors
	124	*/
	125	if((bp->b_flags&B_ERROR) != 0) {
	126	brelse(bp);
	127	iput(ip);
	128	return(NULL);
	129	}
	130	dp = bp->b_un.b_dino;
	131	dp += itoo(ino);
	132	iexpand(ip, dp);
	133	brelse(bp);
	134	return(ip);
	135	}
	136
	137	iexpand(ip, dp)
	138	register struct inode *ip;
	139	register struct dinode *dp;
	140	{
	141	register char p1, p2;
	142	register int i;
	143
	144	ip->i_mode = dp->di_mode;
	145	ip->i_nlink = dp->di_nlink;
	146	ip->i_uid = dp->di_uid;
	147	ip->i_gid = dp->di_gid;
	148	ip->i_size = dp->di_size;
	149	p1 = (char *)ip->i_un.i_addr;
	150	p2 = (char *)dp->di_addr;
	151	for(i=0; i<NADDR; i++) {
	152	p1++ = p2++;
	153	p1++ = p2++;
	154	p1++ = p2++;
	155	*p1++ = 0;
	156	}
	157	}
	158
	159	/*
	160	* Decrement reference count of
	161	* an inode structure.
	162	* On the last reference,
	163	* write the inode out and if necessary,
	164	* truncate and deallocate the file.
	165	*/
	166	iput(ip)
	167	register struct inode *ip;
	168	{
	169	register int i, x;
	170	register struct inode *jp;
	171
	172	if(ip->i_count == 1) {
173	ip->i_flag \|= ILOCK;
174	if(ip->i_nlink <= 0) {
175	itrunc(ip);
176	ip->i_mode = 0;
177	ip->i_flag \|= IUPD\|ICHG;
178	ifree(ip->i_dev, ip->i_number);
179	}
c0bb1685	180	IUPDAT(ip, &time, &time, 0);
5d5124a1 BJ	181	prele(ip);
	182	i = INOHASH(ip->i_dev, ip->i_number);
	183	x = ip - inode;
	184	if (inohash[i] == x) {
	185	inohash[i] = ip->i_hlink;
	186	} else {
	187	for (jp = &inode[inohash[i]]; jp != &inode[-1];
	188	jp = &inode[jp->i_hlink])
	189	if (jp->i_hlink == x) {
	190	jp->i_hlink = ip->i_hlink;
	191	goto done;
	192	}
	193	panic("iput");
	194	}
	195	done:
	196	ip->i_hlink = ifreel;
	197	ifreel = x;
	198	ip->i_flag = 0;
	199	ip->i_number = 0;
	200	} else
	201	prele(ip);
	202	ip->i_count--;
	203	}
	204
	205	/*
	206	* Check accessed and update flags on
	207	* an inode structure.
	208	* If any is on, update the inode
	209	* with the current time.
c0bb1685 BJ	210	* If waitfor is given, then must insure
c0bb1685 BJ	211	* i/o order so wait for write to complete.
5d5124a1	212	*/
c0bb1685	213	iupdat(ip, ta, tm, waitfor)
5d5124a1 BJ	214	register struct inode *ip;
5d5124a1 BJ	215	time_t ta, tm;
c0bb1685	216	int waitfor;
5d5124a1 BJ	217	{
	218	register struct buf *bp;
	219	struct dinode *dp;
	220	register char p1, p2;
	221	register int i;
	222
	223	if((ip->i_flag&(IUPD\|IACC\|ICHG)) != 0) {
	224	if(getfs(ip->i_dev)->s_ronly)
	225	return;
	226	bp = bread(ip->i_dev, itod(ip->i_number));
	227	if (bp->b_flags & B_ERROR) {
	228	brelse(bp);
	229	return;
	230	}
	231	dp = bp->b_un.b_dino;
	232	dp += itoo(ip->i_number);
	233	dp->di_mode = ip->i_mode;
	234	dp->di_nlink = ip->i_nlink;
	235	dp->di_uid = ip->i_uid;
	236	dp->di_gid = ip->i_gid;
	237	dp->di_size = ip->i_size;
	238	p1 = (char *)dp->di_addr;
	239	p2 = (char *)ip->i_un.i_addr;
	240	for(i=0; i<NADDR; i++) {
	241	p1++ = p2++;
	242	p1++ = p2++;
	243	p1++ = p2++;
231ed58b	244	if(*p2++ != 0)
5d5124a1 BJ	245	printf("iaddress > 2^24\n");
	246	}
	247	if(ip->i_flag&IACC)
	248	dp->di_atime = *ta;
	249	if(ip->i_flag&IUPD)
	250	dp->di_mtime = *tm;
	251	if(ip->i_flag&ICHG)
	252	dp->di_ctime = time;
	253	ip->i_flag &= ~(IUPD\|IACC\|ICHG);
c0bb1685 BJ	254	if (waitfor)
	255	bwrite(bp);
	256	else
	257	bdwrite(bp);
5d5124a1 BJ	258	}
	259	}
	260
	261	/*
	262	* Free all the disk blocks associated
	263	* with the specified inode structure.
	264	* The blocks of the file are removed
	265	* in reverse order. This FILO
	266	* algorithm will tend to maintain
	267	* a contiguous free list much longer
	268	* than FIFO.
	269	*/
	270	itrunc(ip)
	271	register struct inode *ip;
	272	{
	273	register i;
	274	dev_t dev;
	275	daddr_t bn;
c0bb1685	276	struct inode itmp;
5d5124a1 BJ	277
	278	if (ip->i_vfdcnt)
	279	panic("itrunc");
	280	i = ip->i_mode & IFMT;
	281	if (i!=IFREG && i!=IFDIR)
	282	return;
c0bb1685 BJ	283
	284	/*
	285	* Clean inode on disk before freeing blocks
	286	* to insure no duplicates if system crashes.
	287	*/
	288	itmp = *ip;
	289	itmp.i_size = 0;
	290	for (i = 0; i < NADDR; i++)
	291	itmp.i_un.i_addr[i] = 0;
	292	itmp.i_flag \|= ICHG\|IUPD;
	293	iupdat(&itmp, &time, &time, 1);
	294	ip->i_flag &= ~(IUPD\|IACC\|ICHG);
	295
	296	/*
	297	* Now return blocks to free list... if machine
	298	* crashes, they will be harmless MISSING blocks.
	299	*/
5d5124a1 BJ	300	dev = ip->i_dev;
	301	for(i=NADDR-1; i>=0; i--) {
	302	bn = ip->i_un.i_addr[i];
	303	if(bn == (daddr_t)0)
	304	continue;
	305	ip->i_un.i_addr[i] = (daddr_t)0;
	306	switch(i) {
	307
	308	default:
	309	free(dev, bn);
	310	break;
	311
	312	case NADDR-3:
	313	tloop(dev, bn, 0, 0);
	314	break;
	315
	316	case NADDR-2:
	317	tloop(dev, bn, 1, 0);
	318	break;
	319
	320	case NADDR-1:
	321	tloop(dev, bn, 1, 1);
	322	}
	323	}
	324	ip->i_size = 0;
c0bb1685 BJ	325	/*
	326	* Inode was written and flags updated above.
	327	* No need to modify flags here.
	328	*/
5d5124a1 BJ	329	}
	330
	331	tloop(dev, bn, f1, f2)
	332	dev_t dev;
	333	daddr_t bn;
	334	{
	335	register i;
	336	register struct buf *bp;
	337	register daddr_t *bap;
	338	daddr_t nb;
	339
	340	bp = NULL;
	341	for(i=NINDIR-1; i>=0; i--) {
	342	if(bp == NULL) {
	343	bp = bread(dev, bn);
	344	if (bp->b_flags & B_ERROR) {
	345	brelse(bp);
	346	return;
	347	}
	348	bap = bp->b_un.b_daddr;
	349	}
	350	nb = bap[i];
	351	if(nb == (daddr_t)0)
	352	continue;
	353	if(f1) {
	354	brelse(bp);
	355	bp = NULL;
	356	tloop(dev, nb, f2, 0);
	357	} else
	358	free(dev, nb);
	359	}
	360	if(bp != NULL)
	361	brelse(bp);
	362	free(dev, bn);
	363	}
	364
	365	/*
	366	* Make a new file.
	367	*/
	368	struct inode *
	369	maknode(mode)
	370	{
	371	register struct inode *ip;
	372
	373	ip = ialloc(u.u_pdir->i_dev);
	374	if(ip == NULL) {
	375	iput(u.u_pdir);
	376	return(NULL);
	377	}
	378	ip->i_flag \|= IACC\|IUPD\|ICHG;
	379	if((mode&IFMT) == 0)
	380	mode \|= IFREG;
	381	ip->i_mode = mode & ~u.u_cmask;
	382	ip->i_nlink = 1;
	383	ip->i_uid = u.u_uid;
	384	ip->i_gid = u.u_gid;
c0bb1685 BJ	385
	386	/*
	387	* Make sure inode goes to disk before directory entry.
	388	*/
	389	iupdat(ip, &time, &time, 1);
	390
5d5124a1 BJ	391	wdir(ip);
	392	return(ip);
	393	}
	394
	395	/*
	396	* Write a directory entry with
	397	* parameters left as side effects
	398	* to a call to namei.
	399	*/
	400	wdir(ip)
	401	struct inode *ip;
	402	{
	403
	404	u.u_dent.d_ino = ip->i_number;
	405	bcopy((caddr_t)u.u_dbuf, (caddr_t)u.u_dent.d_name, DIRSIZ);
	406	u.u_count = sizeof(struct direct);
	407	u.u_segflg = 1;
	408	u.u_base = (caddr_t)&u.u_dent;
	409	writei(u.u_pdir);
	410	iput(u.u_pdir);
	411	}
d6a210b8 BJ	412
	413	#ifdef plock
	414	#undef plock
	415	#endif
	416	#ifdef prele
	417	#undef prele
	418	#endif
	419	/*
	420	* Lock an inode (should be called ilock).
	421	* If its already locked,
	422	* set the WANT bit and sleep.
	423	*/
	424	plock(ip)
	425	register struct inode *ip;
	426	{
	427
	428	while(ip->i_flag&ILOCK) {
	429	ip->i_flag \|= IWANT;
	430	sleep((caddr_t)ip, PINOD);
	431	}
	432	ip->i_flag \|= ILOCK;
	433	}
	434
	435	/*
	436	* Unlock an inode.
	437	* If WANT bit is on,
	438	* wakeup.
	439	*/
	440	prele(ip)
	441	register struct inode *ip;
	442	{
	443
	444	ip->i_flag &= ~ILOCK;
	445	if(ip->i_flag&IWANT) {
	446	ip->i_flag &= ~IWANT;
	447	wakeup((caddr_t)ip);
	448	}
	449	}