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ffs_balloc.c revision 1.2
      1 /*	$NetBSD: ffs_balloc.c,v 1.2 1994/06/29 06:46:29 cgd Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1982, 1986, 1989, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  *
     35  *	@(#)ffs_balloc.c	8.4 (Berkeley) 9/23/93
     36  */
     37 
     38 #include <sys/param.h>
     39 #include <sys/systm.h>
     40 #include <sys/buf.h>
     41 #include <sys/proc.h>
     42 #include <sys/file.h>
     43 #include <sys/vnode.h>
     44 
     45 #include <vm/vm.h>
     46 
     47 #include <ufs/ufs/quota.h>
     48 #include <ufs/ufs/inode.h>
     49 #include <ufs/ufs/ufs_extern.h>
     50 
     51 #include <ufs/ffs/fs.h>
     52 #include <ufs/ffs/ffs_extern.h>
     53 
     54 /*
     55  * Balloc defines the structure of file system storage
     56  * by allocating the physical blocks on a device given
     57  * the inode and the logical block number in a file.
     58  */
     59 ffs_balloc(ip, bn, size, cred, bpp, flags)
     60 	register struct inode *ip;
     61 	register daddr_t bn;
     62 	int size;
     63 	struct ucred *cred;
     64 	struct buf **bpp;
     65 	int flags;
     66 {
     67 	register struct fs *fs;
     68 	register daddr_t nb;
     69 	struct buf *bp, *nbp;
     70 	struct vnode *vp = ITOV(ip);
     71 	struct indir indirs[NIADDR + 2];
     72 	daddr_t newb, lbn, *bap, pref;
     73 	int osize, nsize, num, i, error;
     74 
     75 	*bpp = NULL;
     76 	if (bn < 0)
     77 		return (EFBIG);
     78 	fs = ip->i_fs;
     79 	lbn = bn;
     80 
     81 	/*
     82 	 * If the next write will extend the file into a new block,
     83 	 * and the file is currently composed of a fragment
     84 	 * this fragment has to be extended to be a full block.
     85 	 */
     86 	nb = lblkno(fs, ip->i_size);
     87 	if (nb < NDADDR && nb < bn) {
     88 		osize = blksize(fs, ip, nb);
     89 		if (osize < fs->fs_bsize && osize > 0) {
     90 			error = ffs_realloccg(ip, nb,
     91 				ffs_blkpref(ip, nb, (int)nb, &ip->i_db[0]),
     92 				osize, (int)fs->fs_bsize, cred, &bp);
     93 			if (error)
     94 				return (error);
     95 			ip->i_size = (nb + 1) * fs->fs_bsize;
     96 			vnode_pager_setsize(vp, (u_long)ip->i_size);
     97 			ip->i_db[nb] = dbtofsb(fs, bp->b_blkno);
     98 			ip->i_flag |= IN_CHANGE | IN_UPDATE;
     99 			if (flags & B_SYNC)
    100 				bwrite(bp);
    101 			else
    102 				bawrite(bp);
    103 		}
    104 	}
    105 	/*
    106 	 * The first NDADDR blocks are direct blocks
    107 	 */
    108 	if (bn < NDADDR) {
    109 		nb = ip->i_db[bn];
    110 		if (nb != 0 && ip->i_size >= (bn + 1) * fs->fs_bsize) {
    111 			error = bread(vp, bn, fs->fs_bsize, NOCRED, &bp);
    112 			if (error) {
    113 				brelse(bp);
    114 				return (error);
    115 			}
    116 			*bpp = bp;
    117 			return (0);
    118 		}
    119 		if (nb != 0) {
    120 			/*
    121 			 * Consider need to reallocate a fragment.
    122 			 */
    123 			osize = fragroundup(fs, blkoff(fs, ip->i_size));
    124 			nsize = fragroundup(fs, size);
    125 			if (nsize <= osize) {
    126 				error = bread(vp, bn, osize, NOCRED, &bp);
    127 				if (error) {
    128 					brelse(bp);
    129 					return (error);
    130 				}
    131 			} else {
    132 				error = ffs_realloccg(ip, bn,
    133 				    ffs_blkpref(ip, bn, (int)bn, &ip->i_db[0]),
    134 				    osize, nsize, cred, &bp);
    135 				if (error)
    136 					return (error);
    137 			}
    138 		} else {
    139 			if (ip->i_size < (bn + 1) * fs->fs_bsize)
    140 				nsize = fragroundup(fs, size);
    141 			else
    142 				nsize = fs->fs_bsize;
    143 			error = ffs_alloc(ip, bn,
    144 			    ffs_blkpref(ip, bn, (int)bn, &ip->i_db[0]),
    145 			    nsize, cred, &newb);
    146 			if (error)
    147 				return (error);
    148 			bp = getblk(vp, bn, nsize, 0, 0);
    149 			bp->b_blkno = fsbtodb(fs, newb);
    150 			if (flags & B_CLRBUF)
    151 				clrbuf(bp);
    152 		}
    153 		ip->i_db[bn] = dbtofsb(fs, bp->b_blkno);
    154 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
    155 		*bpp = bp;
    156 		return (0);
    157 	}
    158 	/*
    159 	 * Determine the number of levels of indirection.
    160 	 */
    161 	pref = 0;
    162 	if (error = ufs_getlbns(vp, bn, indirs, &num))
    163 		return(error);
    164 #ifdef DIAGNOSTIC
    165 	if (num < 1)
    166 		panic ("ffs_balloc: ufs_bmaparray returned indirect block\n");
    167 #endif
    168 	/*
    169 	 * Fetch the first indirect block allocating if necessary.
    170 	 */
    171 	--num;
    172 	nb = ip->i_ib[indirs[0].in_off];
    173 	if (nb == 0) {
    174 		pref = ffs_blkpref(ip, lbn, 0, (daddr_t *)0);
    175 	        if (error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
    176 		    cred, &newb))
    177 			return (error);
    178 		nb = newb;
    179 		bp = getblk(vp, indirs[1].in_lbn, fs->fs_bsize, 0, 0);
    180 		bp->b_blkno = fsbtodb(fs, newb);
    181 		clrbuf(bp);
    182 		/*
    183 		 * Write synchronously so that indirect blocks
    184 		 * never point at garbage.
    185 		 */
    186 		if (error = bwrite(bp)) {
    187 			ffs_blkfree(ip, nb, fs->fs_bsize);
    188 			return (error);
    189 		}
    190 		ip->i_ib[indirs[0].in_off] = newb;
    191 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
    192 	}
    193 	/*
    194 	 * Fetch through the indirect blocks, allocating as necessary.
    195 	 */
    196 	for (i = 1;;) {
    197 		error = bread(vp,
    198 		    indirs[i].in_lbn, (int)fs->fs_bsize, NOCRED, &bp);
    199 		if (error) {
    200 			brelse(bp);
    201 			return (error);
    202 		}
    203 		bap = (daddr_t *)bp->b_data;
    204 		nb = bap[indirs[i].in_off];
    205 		if (i == num)
    206 			break;
    207 		i += 1;
    208 		if (nb != 0) {
    209 			brelse(bp);
    210 			continue;
    211 		}
    212 		if (pref == 0)
    213 			pref = ffs_blkpref(ip, lbn, 0, (daddr_t *)0);
    214 		if (error =
    215 		    ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, cred, &newb)) {
    216 			brelse(bp);
    217 			return (error);
    218 		}
    219 		nb = newb;
    220 		nbp = getblk(vp, indirs[i].in_lbn, fs->fs_bsize, 0, 0);
    221 		nbp->b_blkno = fsbtodb(fs, nb);
    222 		clrbuf(nbp);
    223 		/*
    224 		 * Write synchronously so that indirect blocks
    225 		 * never point at garbage.
    226 		 */
    227 		if (error = bwrite(nbp)) {
    228 			ffs_blkfree(ip, nb, fs->fs_bsize);
    229 			brelse(bp);
    230 			return (error);
    231 		}
    232 		bap[indirs[i - 1].in_off] = nb;
    233 		/*
    234 		 * If required, write synchronously, otherwise use
    235 		 * delayed write.
    236 		 */
    237 		if (flags & B_SYNC) {
    238 			bwrite(bp);
    239 		} else {
    240 			bdwrite(bp);
    241 		}
    242 	}
    243 	/*
    244 	 * Get the data block, allocating if necessary.
    245 	 */
    246 	if (nb == 0) {
    247 		pref = ffs_blkpref(ip, lbn, indirs[i].in_off, &bap[0]);
    248 		if (error = ffs_alloc(ip,
    249 		    lbn, pref, (int)fs->fs_bsize, cred, &newb)) {
    250 			brelse(bp);
    251 			return (error);
    252 		}
    253 		nb = newb;
    254 		nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0);
    255 		nbp->b_blkno = fsbtodb(fs, nb);
    256 		if (flags & B_CLRBUF)
    257 			clrbuf(nbp);
    258 		bap[indirs[i].in_off] = nb;
    259 		/*
    260 		 * If required, write synchronously, otherwise use
    261 		 * delayed write.
    262 		 */
    263 		if (flags & B_SYNC) {
    264 			bwrite(bp);
    265 		} else {
    266 			bdwrite(bp);
    267 		}
    268 		*bpp = nbp;
    269 		return (0);
    270 	}
    271 	brelse(bp);
    272 	if (flags & B_CLRBUF) {
    273 		error = bread(vp, lbn, (int)fs->fs_bsize, NOCRED, &nbp);
    274 		if (error) {
    275 			brelse(nbp);
    276 			return (error);
    277 		}
    278 	} else {
    279 		nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0);
    280 		nbp->b_blkno = fsbtodb(fs, nb);
    281 	}
    282 	*bpp = nbp;
    283 	return (0);
    284 }
    285