usr/src/sys/ufs/lfs/lfs_balloc.c

/*
 * Copyright (c) 1982, 1986, 1989 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *	@(#)lfs_balloc.c	7.7 (Berkeley) %G%
 */

#include "param.h"
#include "systm.h"
#include "user.h"
#include "buf.h"
#include "proc.h"
#include "file.h"
#include "vnode.h"
#include "../ufs/inode.h"
#include "../ufs/fs.h"

/*
 * Bmap defines the structure of file system storage
 * by returning the physical block number on a device
 * given the inode and the logical block number in a file.
 */
bmap(ip, bn, bnp)
	register struct inode *ip;
	register daddr_t bn;
	daddr_t	*bnp;
{
	register struct fs *fs;
	register daddr_t nb;
	struct buf *bp;
	daddr_t *bap;
	int i, j, sh;
	int error;

	if (bn < 0)
		return (EFBIG);
	fs = ip->i_fs;

	/*
	 * The first NDADDR blocks are direct blocks
	 */
	if (bn < NDADDR) {
		nb = ip->i_db[bn];
		if (nb == 0) {
			*bnp = (daddr_t)-1;
			return (0);
		}
		*bnp = fsbtodb(fs, nb);
		return (0);
	}
	/*
	 * Determine the number of levels of indirection.
	 */
	sh = 1;
	bn -= NDADDR;
	for (j = NIADDR; j > 0; j--) {
		sh *= NINDIR(fs);
		if (bn < sh)
			break;
		bn -= sh;
	}
	if (j == 0)
		return (EFBIG);
	/*
	 * Fetch through the indirect blocks.
	 */
	nb = ip->i_ib[NIADDR - j];
	if (nb == 0) {
		*bnp = (daddr_t)-1;
		return (0);
	}
	for (; j <= NIADDR; j++) {
		if (error = bread(ip->i_devvp, fsbtodb(fs, nb),
		    (int)fs->fs_bsize, NOCRED, &bp)) {
			brelse(bp);
			return (error);
		}
		bap = bp->b_un.b_daddr;
		sh /= NINDIR(fs);
		i = (bn / sh) % NINDIR(fs);
		nb = bap[i];
		if (nb == 0) {
			*bnp = (daddr_t)-1;
			brelse(bp);
			return (0);
		}
		brelse(bp);
	}
	*bnp = fsbtodb(fs, nb);
	return (0);
}

/*
 * Balloc defines the structure of file system storage
 * by allocating the physical blocks on a device given
 * the inode and the logical block number in a file.
 */
balloc(ip, bn, size, bpp, flags)
	register struct inode *ip;
	register daddr_t bn;
	int size;
	struct buf **bpp;
	int flags;
{
	register struct fs *fs;
	register daddr_t nb;
	struct buf *bp, *nbp;
	struct vnode *vp = ITOV(ip);
	int osize, nsize, i, j, sh, error;
	daddr_t newb, lbn, *bap, pref, blkpref();

	*bpp = (struct buf *)0;
	if (bn < 0)
		return (EFBIG);
	fs = ip->i_fs;

	/*
	 * If the next write will extend the file into a new block,
	 * and the file is currently composed of a fragment
	 * this fragment has to be extended to be a full block.
	 */
	nb = lblkno(fs, ip->i_size);
	if (nb < NDADDR && nb < bn) {
		osize = blksize(fs, ip, nb);
		if (osize < fs->fs_bsize && osize > 0) {
			error = realloccg(ip, nb,
				blkpref(ip, nb, (int)nb, &ip->i_db[0]),
				osize, (int)fs->fs_bsize, &bp);
			if (error)
				return (error);
			ip->i_size = (nb + 1) * fs->fs_bsize;
			ip->i_db[nb] = dbtofsb(fs, bp->b_blkno);
			ip->i_flag |= IUPD|ICHG;
			if (flags & B_SYNC)
				bwrite(bp);
			else
				bawrite(bp);
		}
	}
	/*
	 * The first NDADDR blocks are direct blocks
	 */
	if (bn < NDADDR) {
		nb = ip->i_db[bn];
		if (nb != 0 && ip->i_size >= (bn + 1) * fs->fs_bsize) {
			error = bread(vp, bn, fs->fs_bsize, NOCRED, &bp);
			if (error) {
				brelse(bp);
				return (error);
			}
			*bpp = bp;
			return (0);
		}
		if (nb != 0) {
			/*
			 * Consider need to reallocate a fragment.
			 */
			osize = fragroundup(fs, blkoff(fs, ip->i_size));
			nsize = fragroundup(fs, size);
			if (nsize <= osize) {
				error = bread(vp, bn, osize, NOCRED, &bp);
				if (error) {
					brelse(bp);
					return (error);
				}
			} else {
				error = realloccg(ip, bn,
					blkpref(ip, bn, (int)bn, &ip->i_db[0]),
					osize, nsize, &bp);
				if (error)
					return (error);
			}
		} else {
			if (ip->i_size < (bn + 1) * fs->fs_bsize)
				nsize = fragroundup(fs, size);
			else
				nsize = fs->fs_bsize;
			error = alloc(ip, bn,
				blkpref(ip, bn, (int)bn, &ip->i_db[0]),
				nsize, &newb);
			if (error)
				return (error);
			bp = getblk(vp, bn, nsize);
			bp->b_blkno = fsbtodb(fs, newb);
			if (flags & B_CLRBUF)
				clrbuf(bp);
		}
		ip->i_db[bn] = dbtofsb(fs, bp->b_blkno);
		ip->i_flag |= IUPD|ICHG;
		*bpp = bp;
		return (0);
	}
	/*
	 * Determine the number of levels of indirection.
	 */
	pref = 0;
	sh = 1;
	lbn = bn;
	bn -= NDADDR;
	for (j = NIADDR; j > 0; j--) {
		sh *= NINDIR(fs);
		if (bn < sh)
			break;
		bn -= sh;
	}
	if (j == 0)
		return (EFBIG);
	/*
	 * Fetch the first indirect block allocating if necessary.
	 */
	nb = ip->i_ib[NIADDR - j];
	if (nb == 0) {
		pref = blkpref(ip, lbn, 0, (daddr_t *)0);
	        if (error = alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb))
			return (error);
		nb = newb;
		bp = getblk(ip->i_devvp, fsbtodb(fs, nb), fs->fs_bsize);
		clrbuf(bp);
		/*
		 * Write synchronously so that indirect blocks
		 * never point at garbage.
		 */
		if (error = bwrite(bp)) {
			blkfree(ip, nb, fs->fs_bsize);
			return (error);
		}
		ip->i_ib[NIADDR - j] = nb;
		ip->i_flag |= IUPD|ICHG;
	}
	/*
	 * Fetch through the indirect blocks, allocating as necessary.
	 */
	for (; ; j++) {
		error = bread(ip->i_devvp, fsbtodb(fs, nb),
		    (int)fs->fs_bsize, NOCRED, &bp);
		if (error) {
			brelse(bp);
			return (error);
		}
		bap = bp->b_un.b_daddr;
		sh /= NINDIR(fs);
		i = (bn / sh) % NINDIR(fs);
		nb = bap[i];
		if (j == NIADDR)
			break;
		if (nb != 0) {
			brelse(bp);
			continue;
		}
		if (pref == 0)
			pref = blkpref(ip, lbn, 0, (daddr_t *)0);
		if (error = alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb)) {
			brelse(bp);
			return (error);
		}
		nb = newb;
		nbp = getblk(ip->i_devvp, fsbtodb(fs, nb), fs->fs_bsize);
		clrbuf(nbp);
		/*
		 * Write synchronously so that indirect blocks
		 * never point at garbage.
		 */
		if (error = bwrite(nbp)) {
			blkfree(ip, nb, fs->fs_bsize);
			brelse(bp);
			return (error);
		}
		bap[i] = nb;
		/*
		 * If required, write synchronously, otherwise use
		 * delayed write. If this is the first instance of
		 * the delayed write, reassociate the buffer with the
		 * file so it will be written if the file is sync'ed.
		 */
		if (flags & B_SYNC) {
			bwrite(bp);
		} else if (bp->b_flags & B_DELWRI) {
			bdwrite(bp);
		} else {
			bdwrite(bp);
			reassignbuf(bp, vp);
		}
	}
	/*
	 * Get the data block, allocating if necessary.
	 */
	if (nb == 0) {
		pref = blkpref(ip, lbn, i, &bap[0]);
		if (error = alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb)) {
			brelse(bp);
			return (error);
		}
		nb = newb;
		nbp = getblk(vp, lbn, fs->fs_bsize);
		nbp->b_blkno = fsbtodb(fs, nb);
		if (flags & B_CLRBUF)
			clrbuf(nbp);
		bap[i] = nb;
		/*
		 * If required, write synchronously, otherwise use
		 * delayed write. If this is the first instance of
		 * the delayed write, reassociate the buffer with the
		 * file so it will be written if the file is sync'ed.
		 */
		if (flags & B_SYNC) {
			bwrite(bp);
		} else if (bp->b_flags & B_DELWRI) {
			bdwrite(bp);
		} else {
			bdwrite(bp);
			reassignbuf(bp, vp);
		}
		*bpp = nbp;
		return (0);
	}
	brelse(bp);
	nbp = getblk(vp, lbn, fs->fs_bsize);
	nbp->b_blkno = fsbtodb(fs, nb);
	if ((flags & B_CLRBUF) && (nbp->b_flags & (B_DONE|B_DELWRI)) == 0) {
		brelse(nbp);
		error = bread(vp, lbn, (int)fs->fs_bsize, NOCRED, &nbp);
		if (error) {
			brelse(nbp);
			return (error);
		}
	}
	*bpp = nbp;
	return (0);
}
Commit	Line	Data
	1	/*
	2	* Copyright (c) 1982, 1986, 1989 Regents of the University of California.
	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms are permitted
	6	* provided that the above copyright notice and this paragraph are
	7	* duplicated in all such forms and that any documentation,
	8	* advertising materials, and other materials related to such
	9	* distribution and use acknowledge that the software was developed
	10	* by the University of California, Berkeley. The name of the
	11	* University may not be used to endorse or promote products derived
	12	* from this software without specific prior written permission.
	13	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
	14	* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
	15	* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
	16	*
	17	* @(#)lfs_balloc.c 7.7 (Berkeley) %G%
	18	*/
	19
	20	#include "param.h"
	21	#include "systm.h"
	22	#include "user.h"
	23	#include "buf.h"
	24	#include "proc.h"
	25	#include "file.h"
	26	#include "vnode.h"
	27	#include "../ufs/inode.h"
	28	#include "../ufs/fs.h"
	29
	30	/*
	31	* Bmap defines the structure of file system storage
	32	* by returning the physical block number on a device
	33	* given the inode and the logical block number in a file.
	34	*/
	35	bmap(ip, bn, bnp)
	36	register struct inode *ip;
	37	register daddr_t bn;
	38	daddr_t *bnp;
	39	{
	40	register struct fs *fs;
	41	register daddr_t nb;
	42	struct buf *bp;
	43	daddr_t *bap;
	44	int i, j, sh;
	45	int error;
	46
	47	if (bn < 0)
	48	return (EFBIG);
	49	fs = ip->i_fs;
	50
	51	/*
	52	* The first NDADDR blocks are direct blocks
	53	*/
	54	if (bn < NDADDR) {
	55	nb = ip->i_db[bn];
	56	if (nb == 0) {
	57	*bnp = (daddr_t)-1;
	58	return (0);
	59	}
	60	*bnp = fsbtodb(fs, nb);
	61	return (0);
	62	}
	63	/*
	64	* Determine the number of levels of indirection.
	65	*/
	66	sh = 1;
	67	bn -= NDADDR;
	68	for (j = NIADDR; j > 0; j--) {
	69	sh *= NINDIR(fs);
	70	if (bn < sh)
	71	break;
	72	bn -= sh;
	73	}
	74	if (j == 0)
	75	return (EFBIG);
	76	/*
	77	* Fetch through the indirect blocks.
	78	*/
	79	nb = ip->i_ib[NIADDR - j];
	80	if (nb == 0) {
	81	*bnp = (daddr_t)-1;
	82	return (0);
	83	}
	84	for (; j <= NIADDR; j++) {
	85	if (error = bread(ip->i_devvp, fsbtodb(fs, nb),
	86	(int)fs->fs_bsize, NOCRED, &bp)) {
	87	brelse(bp);
	88	return (error);
	89	}
	90	bap = bp->b_un.b_daddr;
	91	sh /= NINDIR(fs);
	92	i = (bn / sh) % NINDIR(fs);
	93	nb = bap[i];
	94	if (nb == 0) {
	95	*bnp = (daddr_t)-1;
	96	brelse(bp);
	97	return (0);
	98	}
	99	brelse(bp);
	100	}
	101	*bnp = fsbtodb(fs, nb);
	102	return (0);
	103	}
	104
	105	/*
	106	* Balloc defines the structure of file system storage
	107	* by allocating the physical blocks on a device given
	108	* the inode and the logical block number in a file.
	109	*/
	110	balloc(ip, bn, size, bpp, flags)
	111	register struct inode *ip;
	112	register daddr_t bn;
	113	int size;
	114	struct buf **bpp;
	115	int flags;
	116	{
	117	register struct fs *fs;
	118	register daddr_t nb;
	119	struct buf bp, nbp;
	120	struct vnode *vp = ITOV(ip);
	121	int osize, nsize, i, j, sh, error;
	122	daddr_t newb, lbn, *bap, pref, blkpref();
	123
	124	bpp = (struct buf )0;
	125	if (bn < 0)
	126	return (EFBIG);
	127	fs = ip->i_fs;
	128
	129	/*
	130	* If the next write will extend the file into a new block,
	131	* and the file is currently composed of a fragment
	132	* this fragment has to be extended to be a full block.
	133	*/
	134	nb = lblkno(fs, ip->i_size);
	135	if (nb < NDADDR && nb < bn) {
	136	osize = blksize(fs, ip, nb);
	137	if (osize < fs->fs_bsize && osize > 0) {
	138	error = realloccg(ip, nb,
	139	blkpref(ip, nb, (int)nb, &ip->i_db[0]),
	140	osize, (int)fs->fs_bsize, &bp);
	141	if (error)
	142	return (error);
	143	ip->i_size = (nb + 1) * fs->fs_bsize;
	144	ip->i_db[nb] = dbtofsb(fs, bp->b_blkno);
	145	ip->i_flag \|= IUPD\|ICHG;
	146	if (flags & B_SYNC)
	147	bwrite(bp);
	148	else
	149	bawrite(bp);
	150	}
	151	}
	152	/*
	153	* The first NDADDR blocks are direct blocks
	154	*/
	155	if (bn < NDADDR) {
	156	nb = ip->i_db[bn];
	157	if (nb != 0 && ip->i_size >= (bn + 1) * fs->fs_bsize) {
	158	error = bread(vp, bn, fs->fs_bsize, NOCRED, &bp);
	159	if (error) {
	160	brelse(bp);
	161	return (error);
	162	}
	163	*bpp = bp;
	164	return (0);
	165	}
	166	if (nb != 0) {
	167	/*
	168	* Consider need to reallocate a fragment.
	169	*/
	170	osize = fragroundup(fs, blkoff(fs, ip->i_size));
	171	nsize = fragroundup(fs, size);
	172	if (nsize <= osize) {
	173	error = bread(vp, bn, osize, NOCRED, &bp);
	174	if (error) {
	175	brelse(bp);
	176	return (error);
	177	}
	178	} else {
	179	error = realloccg(ip, bn,
	180	blkpref(ip, bn, (int)bn, &ip->i_db[0]),
	181	osize, nsize, &bp);
	182	if (error)
	183	return (error);
	184	}
	185	} else {
	186	if (ip->i_size < (bn + 1) * fs->fs_bsize)
	187	nsize = fragroundup(fs, size);
	188	else
	189	nsize = fs->fs_bsize;
	190	error = alloc(ip, bn,
	191	blkpref(ip, bn, (int)bn, &ip->i_db[0]),
	192	nsize, &newb);
	193	if (error)
	194	return (error);
	195	bp = getblk(vp, bn, nsize);
	196	bp->b_blkno = fsbtodb(fs, newb);
	197	if (flags & B_CLRBUF)
	198	clrbuf(bp);
	199	}
	200	ip->i_db[bn] = dbtofsb(fs, bp->b_blkno);
	201	ip->i_flag \|= IUPD\|ICHG;
	202	*bpp = bp;
	203	return (0);
	204	}
	205	/*
	206	* Determine the number of levels of indirection.
	207	*/
	208	pref = 0;
	209	sh = 1;
	210	lbn = bn;
	211	bn -= NDADDR;
	212	for (j = NIADDR; j > 0; j--) {
	213	sh *= NINDIR(fs);
	214	if (bn < sh)
	215	break;
	216	bn -= sh;
	217	}
	218	if (j == 0)
	219	return (EFBIG);
	220	/*
	221	* Fetch the first indirect block allocating if necessary.
	222	*/
	223	nb = ip->i_ib[NIADDR - j];
	224	if (nb == 0) {
	225	pref = blkpref(ip, lbn, 0, (daddr_t *)0);
	226	if (error = alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb))
	227	return (error);
	228	nb = newb;
	229	bp = getblk(ip->i_devvp, fsbtodb(fs, nb), fs->fs_bsize);
	230	clrbuf(bp);
	231	/*
	232	* Write synchronously so that indirect blocks
	233	* never point at garbage.
	234	*/
	235	if (error = bwrite(bp)) {
	236	blkfree(ip, nb, fs->fs_bsize);
	237	return (error);
	238	}
	239	ip->i_ib[NIADDR - j] = nb;
	240	ip->i_flag \|= IUPD\|ICHG;
	241	}
	242	/*
	243	* Fetch through the indirect blocks, allocating as necessary.
	244	*/
	245	for (; ; j++) {
	246	error = bread(ip->i_devvp, fsbtodb(fs, nb),
	247	(int)fs->fs_bsize, NOCRED, &bp);
	248	if (error) {
	249	brelse(bp);
	250	return (error);
	251	}
	252	bap = bp->b_un.b_daddr;
	253	sh /= NINDIR(fs);
	254	i = (bn / sh) % NINDIR(fs);
	255	nb = bap[i];
	256	if (j == NIADDR)
	257	break;
	258	if (nb != 0) {
	259	brelse(bp);
	260	continue;
	261	}
	262	if (pref == 0)
	263	pref = blkpref(ip, lbn, 0, (daddr_t *)0);
	264	if (error = alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb)) {
	265	brelse(bp);
	266	return (error);
	267	}
	268	nb = newb;
	269	nbp = getblk(ip->i_devvp, fsbtodb(fs, nb), fs->fs_bsize);
	270	clrbuf(nbp);
	271	/*
	272	* Write synchronously so that indirect blocks
	273	* never point at garbage.
	274	*/
	275	if (error = bwrite(nbp)) {
	276	blkfree(ip, nb, fs->fs_bsize);
	277	brelse(bp);
	278	return (error);
	279	}
	280	bap[i] = nb;
	281	/*
	282	* If required, write synchronously, otherwise use
	283	* delayed write. If this is the first instance of
	284	* the delayed write, reassociate the buffer with the
	285	* file so it will be written if the file is sync'ed.
	286	*/
	287	if (flags & B_SYNC) {
	288	bwrite(bp);
	289	} else if (bp->b_flags & B_DELWRI) {
	290	bdwrite(bp);
	291	} else {
	292	bdwrite(bp);
	293	reassignbuf(bp, vp);
	294	}
	295	}
	296	/*
	297	* Get the data block, allocating if necessary.
	298	*/
	299	if (nb == 0) {
	300	pref = blkpref(ip, lbn, i, &bap[0]);
	301	if (error = alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb)) {
	302	brelse(bp);
	303	return (error);
	304	}
	305	nb = newb;
	306	nbp = getblk(vp, lbn, fs->fs_bsize);
	307	nbp->b_blkno = fsbtodb(fs, nb);
	308	if (flags & B_CLRBUF)
	309	clrbuf(nbp);
	310	bap[i] = nb;
	311	/*
	312	* If required, write synchronously, otherwise use
	313	* delayed write. If this is the first instance of
	314	* the delayed write, reassociate the buffer with the
	315	* file so it will be written if the file is sync'ed.
	316	*/
	317	if (flags & B_SYNC) {
	318	bwrite(bp);
	319	} else if (bp->b_flags & B_DELWRI) {
	320	bdwrite(bp);
	321	} else {
	322	bdwrite(bp);
	323	reassignbuf(bp, vp);
	324	}
	325	*bpp = nbp;
	326	return (0);
	327	}
	328	brelse(bp);
	329	nbp = getblk(vp, lbn, fs->fs_bsize);
	330	nbp->b_blkno = fsbtodb(fs, nb);
	331	if ((flags & B_CLRBUF) && (nbp->b_flags & (B_DONE\|B_DELWRI)) == 0) {
	332	brelse(nbp);
	333	error = bread(vp, lbn, (int)fs->fs_bsize, NOCRED, &nbp);
	334	if (error) {
	335	brelse(nbp);
	336	return (error);
	337	}
	338	}
	339	*bpp = nbp;
	340	return (0);
	341	}