Home | History | Annotate | Line # | Download | only in ffs
ffs_balloc.c revision 1.1.1.1
      1 /*
      2  * Copyright (c) 1982, 1986, 1989, 1993
      3  *	The Regents of the University of California.  All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. All advertising materials mentioning features or use of this software
     14  *    must display the following acknowledgement:
     15  *	This product includes software developed by the University of
     16  *	California, Berkeley and its contributors.
     17  * 4. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  *
     33  *	@(#)ffs_balloc.c	8.4 (Berkeley) 9/23/93
     34  */
     35 
     36 #include <sys/param.h>
     37 #include <sys/systm.h>
     38 #include <sys/buf.h>
     39 #include <sys/proc.h>
     40 #include <sys/file.h>
     41 #include <sys/vnode.h>
     42 
     43 #include <vm/vm.h>
     44 
     45 #include <ufs/ufs/quota.h>
     46 #include <ufs/ufs/inode.h>
     47 #include <ufs/ufs/ufs_extern.h>
     48 
     49 #include <ufs/ffs/fs.h>
     50 #include <ufs/ffs/ffs_extern.h>
     51 
     52 /*
     53  * Balloc defines the structure of file system storage
     54  * by allocating the physical blocks on a device given
     55  * the inode and the logical block number in a file.
     56  */
     57 ffs_balloc(ip, bn, size, cred, bpp, flags)
     58 	register struct inode *ip;
     59 	register daddr_t bn;
     60 	int size;
     61 	struct ucred *cred;
     62 	struct buf **bpp;
     63 	int flags;
     64 {
     65 	register struct fs *fs;
     66 	register daddr_t nb;
     67 	struct buf *bp, *nbp;
     68 	struct vnode *vp = ITOV(ip);
     69 	struct indir indirs[NIADDR + 2];
     70 	daddr_t newb, lbn, *bap, pref;
     71 	int osize, nsize, num, i, error;
     72 
     73 	*bpp = NULL;
     74 	if (bn < 0)
     75 		return (EFBIG);
     76 	fs = ip->i_fs;
     77 	lbn = bn;
     78 
     79 	/*
     80 	 * If the next write will extend the file into a new block,
     81 	 * and the file is currently composed of a fragment
     82 	 * this fragment has to be extended to be a full block.
     83 	 */
     84 	nb = lblkno(fs, ip->i_size);
     85 	if (nb < NDADDR && nb < bn) {
     86 		osize = blksize(fs, ip, nb);
     87 		if (osize < fs->fs_bsize && osize > 0) {
     88 			error = ffs_realloccg(ip, nb,
     89 				ffs_blkpref(ip, nb, (int)nb, &ip->i_db[0]),
     90 				osize, (int)fs->fs_bsize, cred, &bp);
     91 			if (error)
     92 				return (error);
     93 			ip->i_size = (nb + 1) * fs->fs_bsize;
     94 			vnode_pager_setsize(vp, (u_long)ip->i_size);
     95 			ip->i_db[nb] = dbtofsb(fs, bp->b_blkno);
     96 			ip->i_flag |= IN_CHANGE | IN_UPDATE;
     97 			if (flags & B_SYNC)
     98 				bwrite(bp);
     99 			else
    100 				bawrite(bp);
    101 		}
    102 	}
    103 	/*
    104 	 * The first NDADDR blocks are direct blocks
    105 	 */
    106 	if (bn < NDADDR) {
    107 		nb = ip->i_db[bn];
    108 		if (nb != 0 && ip->i_size >= (bn + 1) * fs->fs_bsize) {
    109 			error = bread(vp, bn, fs->fs_bsize, NOCRED, &bp);
    110 			if (error) {
    111 				brelse(bp);
    112 				return (error);
    113 			}
    114 			*bpp = bp;
    115 			return (0);
    116 		}
    117 		if (nb != 0) {
    118 			/*
    119 			 * Consider need to reallocate a fragment.
    120 			 */
    121 			osize = fragroundup(fs, blkoff(fs, ip->i_size));
    122 			nsize = fragroundup(fs, size);
    123 			if (nsize <= osize) {
    124 				error = bread(vp, bn, osize, NOCRED, &bp);
    125 				if (error) {
    126 					brelse(bp);
    127 					return (error);
    128 				}
    129 			} else {
    130 				error = ffs_realloccg(ip, bn,
    131 				    ffs_blkpref(ip, bn, (int)bn, &ip->i_db[0]),
    132 				    osize, nsize, cred, &bp);
    133 				if (error)
    134 					return (error);
    135 			}
    136 		} else {
    137 			if (ip->i_size < (bn + 1) * fs->fs_bsize)
    138 				nsize = fragroundup(fs, size);
    139 			else
    140 				nsize = fs->fs_bsize;
    141 			error = ffs_alloc(ip, bn,
    142 			    ffs_blkpref(ip, bn, (int)bn, &ip->i_db[0]),
    143 			    nsize, cred, &newb);
    144 			if (error)
    145 				return (error);
    146 			bp = getblk(vp, bn, nsize, 0, 0);
    147 			bp->b_blkno = fsbtodb(fs, newb);
    148 			if (flags & B_CLRBUF)
    149 				clrbuf(bp);
    150 		}
    151 		ip->i_db[bn] = dbtofsb(fs, bp->b_blkno);
    152 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
    153 		*bpp = bp;
    154 		return (0);
    155 	}
    156 	/*
    157 	 * Determine the number of levels of indirection.
    158 	 */
    159 	pref = 0;
    160 	if (error = ufs_getlbns(vp, bn, indirs, &num))
    161 		return(error);
    162 #ifdef DIAGNOSTIC
    163 	if (num < 1)
    164 		panic ("ffs_balloc: ufs_bmaparray returned indirect block\n");
    165 #endif
    166 	/*
    167 	 * Fetch the first indirect block allocating if necessary.
    168 	 */
    169 	--num;
    170 	nb = ip->i_ib[indirs[0].in_off];
    171 	if (nb == 0) {
    172 		pref = ffs_blkpref(ip, lbn, 0, (daddr_t *)0);
    173 	        if (error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
    174 		    cred, &newb))
    175 			return (error);
    176 		nb = newb;
    177 		bp = getblk(vp, indirs[1].in_lbn, fs->fs_bsize, 0, 0);
    178 		bp->b_blkno = fsbtodb(fs, newb);
    179 		clrbuf(bp);
    180 		/*
    181 		 * Write synchronously so that indirect blocks
    182 		 * never point at garbage.
    183 		 */
    184 		if (error = bwrite(bp)) {
    185 			ffs_blkfree(ip, nb, fs->fs_bsize);
    186 			return (error);
    187 		}
    188 		ip->i_ib[indirs[0].in_off] = newb;
    189 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
    190 	}
    191 	/*
    192 	 * Fetch through the indirect blocks, allocating as necessary.
    193 	 */
    194 	for (i = 1;;) {
    195 		error = bread(vp,
    196 		    indirs[i].in_lbn, (int)fs->fs_bsize, NOCRED, &bp);
    197 		if (error) {
    198 			brelse(bp);
    199 			return (error);
    200 		}
    201 		bap = (daddr_t *)bp->b_data;
    202 		nb = bap[indirs[i].in_off];
    203 		if (i == num)
    204 			break;
    205 		i += 1;
    206 		if (nb != 0) {
    207 			brelse(bp);
    208 			continue;
    209 		}
    210 		if (pref == 0)
    211 			pref = ffs_blkpref(ip, lbn, 0, (daddr_t *)0);
    212 		if (error =
    213 		    ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, cred, &newb)) {
    214 			brelse(bp);
    215 			return (error);
    216 		}
    217 		nb = newb;
    218 		nbp = getblk(vp, indirs[i].in_lbn, fs->fs_bsize, 0, 0);
    219 		nbp->b_blkno = fsbtodb(fs, nb);
    220 		clrbuf(nbp);
    221 		/*
    222 		 * Write synchronously so that indirect blocks
    223 		 * never point at garbage.
    224 		 */
    225 		if (error = bwrite(nbp)) {
    226 			ffs_blkfree(ip, nb, fs->fs_bsize);
    227 			brelse(bp);
    228 			return (error);
    229 		}
    230 		bap[indirs[i - 1].in_off] = nb;
    231 		/*
    232 		 * If required, write synchronously, otherwise use
    233 		 * delayed write.
    234 		 */
    235 		if (flags & B_SYNC) {
    236 			bwrite(bp);
    237 		} else {
    238 			bdwrite(bp);
    239 		}
    240 	}
    241 	/*
    242 	 * Get the data block, allocating if necessary.
    243 	 */
    244 	if (nb == 0) {
    245 		pref = ffs_blkpref(ip, lbn, indirs[i].in_off, &bap[0]);
    246 		if (error = ffs_alloc(ip,
    247 		    lbn, pref, (int)fs->fs_bsize, cred, &newb)) {
    248 			brelse(bp);
    249 			return (error);
    250 		}
    251 		nb = newb;
    252 		nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0);
    253 		nbp->b_blkno = fsbtodb(fs, nb);
    254 		if (flags & B_CLRBUF)
    255 			clrbuf(nbp);
    256 		bap[indirs[i].in_off] = nb;
    257 		/*
    258 		 * If required, write synchronously, otherwise use
    259 		 * delayed write.
    260 		 */
    261 		if (flags & B_SYNC) {
    262 			bwrite(bp);
    263 		} else {
    264 			bdwrite(bp);
    265 		}
    266 		*bpp = nbp;
    267 		return (0);
    268 	}
    269 	brelse(bp);
    270 	if (flags & B_CLRBUF) {
    271 		error = bread(vp, lbn, (int)fs->fs_bsize, NOCRED, &nbp);
    272 		if (error) {
    273 			brelse(nbp);
    274 			return (error);
    275 		}
    276 	} else {
    277 		nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0);
    278 		nbp->b_blkno = fsbtodb(fs, nb);
    279 	}
    280 	*bpp = nbp;
    281 	return (0);
    282 }
    283