2 * modified for Lites 1.1
4 * Aug 1995, Godmar Back (gback@cs.utah.edu)
5 * University of Utah, Department of Computer Science
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39 * @(#)ffs_balloc.c 8.4 (Berkeley) 9/23/93
40 * $FreeBSD: src/sys/gnu/ext2fs/ext2_balloc.c,v 1.9.2.1 2000/08/03 00:52:57 peter Exp $
41 * $DragonFly: src/sys/vfs/gnu/ext2fs/ext2_balloc.c,v 1.3 2003/07/21 07:57:42 dillon Exp $
44 #include <sys/param.h>
45 #include <sys/systm.h>
48 #include <sys/ucred.h>
49 #include <sys/vnode.h>
51 #include <ufs/ufs/quota.h>
52 #include <ufs/ufs/inode.h>
53 #include <ufs/ufs/ufs_extern.h>
55 #include <gnu/ext2fs/ext2_fs.h>
56 #include <gnu/ext2fs/ext2_fs_sb.h>
57 #include <gnu/ext2fs/fs.h>
58 #include <gnu/ext2fs/ext2_extern.h>
61 * Balloc defines the structure of file system storage
62 * by allocating the physical blocks on a device given
63 * the inode and the logical block number in a file.
66 ext2_balloc(ip, bn, size, cred, bpp, flags)
67 register struct inode *ip;
74 register struct ext2_sb_info *fs;
77 struct vnode *vp = ITOV(ip);
78 struct indir indirs[NIADDR + 2];
79 daddr_t newb, lbn, *bap, pref;
80 int osize, nsize, num, i, error;
82 ext2_debug("ext2_balloc called (%d, %d, %d)\n",
83 ip->i_number, (int)bn, (int)size);
92 * check if this is a sequential block allocation.
93 * If so, increment next_alloc fields to allow ext2_blkpref
94 * to make a good guess
96 if (lbn == ip->i_next_alloc_block + 1) {
97 ip->i_next_alloc_block++;
98 ip->i_next_alloc_goal++;
102 * The first NDADDR blocks are direct blocks
106 /* no new block is to be allocated, and no need to expand
108 if (nb != 0 && ip->i_size >= (bn + 1) * fs->s_blocksize) {
109 error = bread(vp, bn, fs->s_blocksize, &bp);
119 * Consider need to reallocate a fragment.
121 osize = fragroundup(fs, blkoff(fs, ip->i_size));
122 nsize = fragroundup(fs, size);
123 if (nsize <= osize) {
124 error = bread(vp, bn, osize, &bp);
130 /* Godmar thinks: this shouldn't happen w/o fragments */
131 printf("nsize %d(%d) > osize %d(%d) nb %d\n",
132 (int)nsize, (int)size, (int)osize,
133 (int)ip->i_size, (int)nb);
135 "ext2_balloc: Something is terribly wrong");
137 * please note there haven't been any changes from here on -
142 if (ip->i_size < (bn + 1) * fs->s_blocksize)
143 nsize = fragroundup(fs, size);
145 nsize = fs->s_blocksize;
146 error = ext2_alloc(ip, bn,
147 ext2_blkpref(ip, bn, (int)bn, &ip->i_db[0], 0),
151 bp = getblk(vp, bn, nsize, 0, 0);
152 bp->b_blkno = fsbtodb(fs, newb);
153 if (flags & B_CLRBUF)
156 ip->i_db[bn] = dbtofsb(fs, bp->b_blkno);
157 ip->i_flag |= IN_CHANGE | IN_UPDATE;
162 * Determine the number of levels of indirection.
165 if ((error = ufs_getlbns(vp, bn, indirs, &num)) != 0)
169 panic ("ext2_balloc: ufs_bmaparray returned indirect block");
172 * Fetch the first indirect block allocating if necessary.
175 nb = ip->i_ib[indirs[0].in_off];
178 pref = ext2_blkpref(ip, lbn, 0, (daddr_t *)0, 0);
180 /* see the comment by ext2_blkpref. What we do here is
181 to pretend that it'd be good for a block holding indirect
182 pointers to be allocated near its predecessor in terms
183 of indirection, or the last direct block.
184 We shamelessly exploit the fact that i_ib immediately
186 Godmar thinks it make sense to allocate i_ib[0] immediately
187 after i_db[11], but it's not utterly clear whether this also
188 applies to i_ib[1] and i_ib[0]
191 pref = ext2_blkpref(ip, lbn, indirs[0].in_off +
192 EXT2_NDIR_BLOCKS, &ip->i_db[0], 0);
194 if ((error = ext2_alloc(ip, lbn, pref, (int)fs->s_blocksize,
198 bp = getblk(vp, indirs[1].in_lbn, fs->s_blocksize, 0, 0);
199 bp->b_blkno = fsbtodb(fs, newb);
202 * Write synchronously so that indirect blocks
203 * never point at garbage.
205 if ((error = bwrite(bp)) != 0) {
206 ext2_blkfree(ip, nb, fs->s_blocksize);
209 ip->i_ib[indirs[0].in_off] = newb;
210 ip->i_flag |= IN_CHANGE | IN_UPDATE;
213 * Fetch through the indirect blocks, allocating as necessary.
217 indirs[i].in_lbn, (int)fs->s_blocksize, &bp);
222 bap = (daddr_t *)bp->b_data;
223 nb = bap[indirs[i].in_off];
233 /* see the comment above and by ext2_blkpref
234 * I think this implements Linux policy, but
235 * does it really make sense to allocate to
236 * block containing pointers together ?
237 * Also, will it ever succeed ?
239 pref = ext2_blkpref(ip, lbn, indirs[i].in_off, bap,
242 pref = ext2_blkpref(ip, lbn, 0, (daddr_t *)0, 0);
245 ext2_alloc(ip, lbn, pref, (int)fs->s_blocksize, cred, &newb)) != 0) {
250 nbp = getblk(vp, indirs[i].in_lbn, fs->s_blocksize, 0, 0);
251 nbp->b_blkno = fsbtodb(fs, nb);
254 * Write synchronously so that indirect blocks
255 * never point at garbage.
257 if ((error = bwrite(nbp)) != 0) {
258 ext2_blkfree(ip, nb, fs->s_blocksize);
262 bap[indirs[i - 1].in_off] = nb;
264 * If required, write synchronously, otherwise use
267 if (flags & B_SYNC) {
274 * Get the data block, allocating if necessary.
277 pref = ext2_blkpref(ip, lbn, indirs[i].in_off, &bap[0],
279 if ((error = ext2_alloc(ip,
280 lbn, pref, (int)fs->s_blocksize, cred, &newb)) != 0) {
285 nbp = getblk(vp, lbn, fs->s_blocksize, 0, 0);
286 nbp->b_blkno = fsbtodb(fs, nb);
287 if (flags & B_CLRBUF)
289 bap[indirs[i].in_off] = nb;
291 * If required, write synchronously, otherwise use
294 if (flags & B_SYNC) {
303 if (flags & B_CLRBUF) {
304 error = bread(vp, lbn, (int)fs->s_blocksize, &nbp);
310 nbp = getblk(vp, lbn, fs->s_blocksize, 0, 0);
311 nbp->b_blkno = fsbtodb(fs, nb);