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ext2fs_balloc.c revision 1.19.2.3
      1 /*	$NetBSD: ext2fs_balloc.c,v 1.19.2.3 2004/09/21 13:39:07 skrll 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. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  *
     31  *	@(#)ffs_balloc.c	8.4 (Berkeley) 9/23/93
     32  * Modified for ext2fs by Manuel Bouyer.
     33  */
     34 
     35 /*
     36  * Copyright (c) 1997 Manuel Bouyer.
     37  *
     38  * Redistribution and use in source and binary forms, with or without
     39  * modification, are permitted provided that the following conditions
     40  * are met:
     41  * 1. Redistributions of source code must retain the above copyright
     42  *    notice, this list of conditions and the following disclaimer.
     43  * 2. Redistributions in binary form must reproduce the above copyright
     44  *    notice, this list of conditions and the following disclaimer in the
     45  *    documentation and/or other materials provided with the distribution.
     46  * 3. All advertising materials mentioning features or use of this software
     47  *    must display the following acknowledgement:
     48  *	This product includes software developed by Manuel Bouyer.
     49  * 4. The name of the author may not be used to endorse or promote products
     50  *    derived from this software without specific prior written permission.
     51  *
     52  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     53  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     54  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     55  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     56  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     57  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     58  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     59  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     60  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     61  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     62  *
     63  *	@(#)ffs_balloc.c	8.4 (Berkeley) 9/23/93
     64  * Modified for ext2fs by Manuel Bouyer.
     65  */
     66 
     67 #include <sys/cdefs.h>
     68 __KERNEL_RCSID(0, "$NetBSD: ext2fs_balloc.c,v 1.19.2.3 2004/09/21 13:39:07 skrll Exp $");
     69 
     70 #if defined(_KERNEL_OPT)
     71 #include "opt_uvmhist.h"
     72 #endif
     73 
     74 #include <sys/param.h>
     75 #include <sys/systm.h>
     76 #include <sys/buf.h>
     77 #include <sys/proc.h>
     78 #include <sys/file.h>
     79 #include <sys/vnode.h>
     80 #include <sys/mount.h>
     81 
     82 #include <uvm/uvm.h>
     83 
     84 #include <ufs/ufs/inode.h>
     85 #include <ufs/ufs/ufs_extern.h>
     86 
     87 #include <ufs/ext2fs/ext2fs.h>
     88 #include <ufs/ext2fs/ext2fs_extern.h>
     89 
     90 /*
     91  * Balloc defines the structure of file system storage
     92  * by allocating the physical blocks on a device given
     93  * the inode and the logical block number in a file.
     94  */
     95 int
     96 ext2fs_balloc(ip, bn, size, cred, bpp, flags)
     97 	struct inode *ip;
     98 	daddr_t bn;
     99 	int size;
    100 	struct ucred *cred;
    101 	struct buf **bpp;
    102 	int flags;
    103 {
    104 	struct m_ext2fs *fs;
    105 	daddr_t nb;
    106 	struct buf *bp, *nbp;
    107 	struct vnode *vp = ITOV(ip);
    108 	struct indir indirs[NIADDR + 2];
    109 	daddr_t newb, lbn, pref;
    110 	int32_t *bap;	/* XXX ondisk32 */
    111 	int num, i, error;
    112 	u_int deallocated;
    113 	daddr_t *blkp, *allocblk, allociblk[NIADDR + 1];
    114 	int32_t *allocib;	/* XXX ondisk32 */
    115 	int unwindidx = -1;
    116 	UVMHIST_FUNC("ext2fs_balloc"); UVMHIST_CALLED(ubchist);
    117 
    118 	UVMHIST_LOG(ubchist, "bn 0x%x", bn,0,0,0);
    119 
    120 	if (bpp != NULL) {
    121 		*bpp = NULL;
    122 	}
    123 	if (bn < 0)
    124 		return (EFBIG);
    125 	fs = ip->i_e2fs;
    126 	lbn = bn;
    127 
    128 	/*
    129 	 * The first NDADDR blocks are direct blocks
    130 	 */
    131 	if (bn < NDADDR) {
    132 		/* XXX ondisk32 */
    133 		nb = fs2h32(ip->i_e2fs_blocks[bn]);
    134 		if (nb != 0) {
    135 
    136 			/*
    137 			 * the block is already allocated, just read it.
    138 			 */
    139 
    140 			if (bpp != NULL) {
    141 				error = bread(vp, bn, fs->e2fs_bsize, NOCRED,
    142 					      &bp);
    143 				if (error) {
    144 					brelse(bp);
    145 					return (error);
    146 				}
    147 				*bpp = bp;
    148 			}
    149 			return (0);
    150 		}
    151 
    152 		/*
    153 		 * allocate a new direct block.
    154 		 */
    155 
    156 		error = ext2fs_alloc(ip, bn,
    157 		    ext2fs_blkpref(ip, bn, bn, &ip->i_e2fs_blocks[0]),
    158 		    cred, &newb);
    159 		if (error)
    160 			return (error);
    161 		ip->i_e2fs_last_lblk = lbn;
    162 		ip->i_e2fs_last_blk = newb;
    163 		/* XXX ondisk32 */
    164 		ip->i_e2fs_blocks[bn] = h2fs32((int32_t)newb);
    165 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
    166 		if (bpp != NULL) {
    167 			bp = getblk(vp, bn, fs->e2fs_bsize, 0, 0);
    168 			bp->b_blkno = fsbtodb(fs, newb);
    169 			if (flags & B_CLRBUF)
    170 				clrbuf(bp);
    171 			*bpp = bp;
    172 		}
    173 		return (0);
    174 	}
    175 	/*
    176 	 * Determine the number of levels of indirection.
    177 	 */
    178 	pref = 0;
    179 	if ((error = ufs_getlbns(vp, bn, indirs, &num)) != 0)
    180 		return(error);
    181 #ifdef DIAGNOSTIC
    182 	if (num < 1)
    183 		panic ("ext2fs_balloc: ufs_getlbns returned indirect block\n");
    184 #endif
    185 	/*
    186 	 * Fetch the first indirect block allocating if necessary.
    187 	 */
    188 	--num;
    189 	/* XXX ondisk32 */
    190 	nb = fs2h32(ip->i_e2fs_blocks[NDADDR + indirs[0].in_off]);
    191 	allocib = NULL;
    192 	allocblk = allociblk;
    193 	if (nb == 0) {
    194 		pref = ext2fs_blkpref(ip, lbn, 0, (int32_t *)0);
    195 		error = ext2fs_alloc(ip, lbn, pref, cred, &newb);
    196 		if (error)
    197 			return (error);
    198 		nb = newb;
    199 		*allocblk++ = nb;
    200 		ip->i_e2fs_last_blk = newb;
    201 		bp = getblk(vp, indirs[1].in_lbn, fs->e2fs_bsize, 0, 0);
    202 		bp->b_blkno = fsbtodb(fs, newb);
    203 		clrbuf(bp);
    204 		/*
    205 		 * Write synchronously so that indirect blocks
    206 		 * never point at garbage.
    207 		 */
    208 		if ((error = bwrite(bp)) != 0)
    209 			goto fail;
    210 		unwindidx = 0;
    211 		allocib = &ip->i_e2fs_blocks[NDADDR + indirs[0].in_off];
    212 		/* XXX ondisk32 */
    213 		*allocib = h2fs32((int32_t)newb);
    214 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
    215 	}
    216 	/*
    217 	 * Fetch through the indirect blocks, allocating as necessary.
    218 	 */
    219 	for (i = 1;;) {
    220 		error = bread(vp,
    221 		    indirs[i].in_lbn, (int)fs->e2fs_bsize, NOCRED, &bp);
    222 		if (error) {
    223 			brelse(bp);
    224 			goto fail;
    225 		}
    226 		bap = (int32_t *)bp->b_data;	/* XXX ondisk32 */
    227 		nb = fs2h32(bap[indirs[i].in_off]);
    228 		if (i == num)
    229 			break;
    230 		i++;
    231 		if (nb != 0) {
    232 			brelse(bp);
    233 			continue;
    234 		}
    235 		pref = ext2fs_blkpref(ip, lbn, 0, (int32_t *)0);
    236 		error = ext2fs_alloc(ip, lbn, pref, cred, &newb);
    237 		if (error) {
    238 			brelse(bp);
    239 			goto fail;
    240 		}
    241 		nb = newb;
    242 		*allocblk++ = nb;
    243 		ip->i_e2fs_last_blk = newb;
    244 		nbp = getblk(vp, indirs[i].in_lbn, fs->e2fs_bsize, 0, 0);
    245 		nbp->b_blkno = fsbtodb(fs, nb);
    246 		clrbuf(nbp);
    247 		/*
    248 		 * Write synchronously so that indirect blocks
    249 		 * never point at garbage.
    250 		 */
    251 		if ((error = bwrite(nbp)) != 0) {
    252 			brelse(bp);
    253 			goto fail;
    254 		}
    255 		if (unwindidx < 0)
    256 			unwindidx = i - 1;
    257 		/* XXX ondisk32 */
    258 		bap[indirs[i - 1].in_off] = h2fs32((int32_t)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 	}
    269 	/*
    270 	 * Get the data block, allocating if necessary.
    271 	 */
    272 	if (nb == 0) {
    273 		pref = ext2fs_blkpref(ip, lbn, indirs[num].in_off, &bap[0]);
    274 		error = ext2fs_alloc(ip, lbn, pref, cred, &newb);
    275 		if (error) {
    276 			brelse(bp);
    277 			goto fail;
    278 		}
    279 		nb = newb;
    280 		*allocblk++ = nb;
    281 		ip->i_e2fs_last_lblk = lbn;
    282 		ip->i_e2fs_last_blk = newb;
    283 		/* XXX ondisk32 */
    284 		bap[indirs[num].in_off] = h2fs32((int32_t)nb);
    285 		/*
    286 		 * If required, write synchronously, otherwise use
    287 		 * delayed write.
    288 		 */
    289 		if (flags & B_SYNC) {
    290 			bwrite(bp);
    291 		} else {
    292 			bdwrite(bp);
    293 		}
    294 		if (bpp != NULL) {
    295 			nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0);
    296 			nbp->b_blkno = fsbtodb(fs, nb);
    297 			if (flags & B_CLRBUF)
    298 				clrbuf(nbp);
    299 			*bpp = nbp;
    300 		}
    301 		return (0);
    302 	}
    303 	brelse(bp);
    304 	if (bpp != NULL) {
    305 		if (flags & B_CLRBUF) {
    306 			error = bread(vp, lbn, (int)fs->e2fs_bsize, NOCRED,
    307 				      &nbp);
    308 			if (error) {
    309 				brelse(nbp);
    310 				goto fail;
    311 			}
    312 		} else {
    313 			nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0);
    314 			nbp->b_blkno = fsbtodb(fs, nb);
    315 		}
    316 		*bpp = nbp;
    317 	}
    318 	return (0);
    319 fail:
    320 	/*
    321 	 * If we have failed part way through block allocation, we
    322 	 * have to deallocate any indirect blocks that we have allocated.
    323 	 */
    324 	for (deallocated = 0, blkp = allociblk; blkp < allocblk; blkp++) {
    325 		ext2fs_blkfree(ip, *blkp);
    326 		deallocated += fs->e2fs_bsize;
    327 	}
    328 	if (unwindidx >= 0) {
    329 		if (unwindidx == 0) {
    330 			*allocib = 0;
    331 		} else {
    332 			int r;
    333 
    334 			r = bread(vp, indirs[unwindidx].in_lbn,
    335 			    (int)fs->e2fs_bsize, NOCRED, &bp);
    336 			if (r) {
    337 				panic("Could not unwind indirect block, error %d", r);
    338 				brelse(bp);
    339 			} else {
    340 				bap = (int32_t *)bp->b_data; /* XXX ondisk32 */
    341 				bap[indirs[unwindidx].in_off] = 0;
    342 				if (flags & B_SYNC)
    343 					bwrite(bp);
    344 				else
    345 					bdwrite(bp);
    346 			}
    347 		}
    348 		for (i = unwindidx + 1; i <= num; i++) {
    349 			bp = getblk(vp, indirs[i].in_lbn, (int)fs->e2fs_bsize,
    350 			    0, 0);
    351 			bp->b_flags |= B_INVAL;
    352 			brelse(bp);
    353 		}
    354 	}
    355 	if (deallocated) {
    356 		ip->i_e2fs_nblock -= btodb(deallocated);
    357 		ip->i_e2fs_flags |= IN_CHANGE | IN_UPDATE;
    358 	}
    359 	return error;
    360 }
    361 
    362 int
    363 ext2fs_gop_alloc(struct vnode *vp, off_t off, off_t len, int flags,
    364     struct ucred *cred)
    365 {
    366 	struct inode *ip = VTOI(vp);
    367 	struct m_ext2fs *fs = ip->i_e2fs;
    368 	int error, delta, bshift, bsize;
    369 	UVMHIST_FUNC("ext2fs_gop_alloc"); UVMHIST_CALLED(ubchist);
    370 
    371 	bshift = fs->e2fs_bshift;
    372 	bsize = 1 << bshift;
    373 
    374 	delta = off & (bsize - 1);
    375 	off -= delta;
    376 	len += delta;
    377 
    378 	while (len > 0) {
    379 		bsize = min(bsize, len);
    380 		UVMHIST_LOG(ubchist, "off 0x%x len 0x%x bsize 0x%x",
    381 			    off, len, bsize, 0);
    382 
    383 		error = ext2fs_balloc(ip, lblkno(fs, off), bsize, cred,
    384 		    NULL, flags);
    385 		if (error) {
    386 			UVMHIST_LOG(ubchist, "error %d", error, 0,0,0);
    387 			return error;
    388 		}
    389 
    390 		/*
    391 		 * increase file size now, VOP_BALLOC() requires that
    392 		 * EOF be up-to-date before each call.
    393 		 */
    394 
    395 		if (ip->i_e2fs_size < off + bsize) {
    396 			UVMHIST_LOG(ubchist, "old 0x%x new 0x%x",
    397 				    ip->i_e2fs_size, off + bsize,0,0);
    398 			ip->i_e2fs_size = off + bsize;
    399 		}
    400 
    401 		off += bsize;
    402 		len -= bsize;
    403 	}
    404 	return 0;
    405 }
    406