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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35 * @(#)ffs_balloc.c 8.4 (Berkeley) 9/23/93
39 #include <sys/param.h>
40 #include <sys/systm.h>
44 #include <sys/ucred.h>
45 #include <sys/vnode.h>
47 #include <fs/ext2fs/inode.h>
48 #include <fs/ext2fs/ext2fs.h>
49 #include <fs/ext2fs/fs.h>
50 #include <fs/ext2fs/ext2_extern.h>
51 #include <fs/ext2fs/ext2_mount.h>
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.
58 ext2_balloc(ip, lbn, size, cred, bpp, flags)
67 struct ext2mount *ump;
70 struct vnode *vp = ITOV(ip);
71 struct indir indirs[NIADDR + 2];
72 int32_t newb, *bap, pref;
73 int osize, nsize, num, i, error;
82 * check if this is a sequential block allocation.
83 * If so, increment next_alloc fields to allow ext2_blkpref
84 * to make a good guess
86 if (lbn == ip->i_next_alloc_block + 1) {
87 ip->i_next_alloc_block++;
88 ip->i_next_alloc_goal++;
92 * The first NDADDR blocks are direct blocks
96 /* no new block is to be allocated, and no need to expand
98 if (nb != 0 && ip->i_size >= (lbn + 1) * fs->e2fs_bsize) {
99 error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &bp);
104 bp->b_blkno = fsbtodb(fs, nb);
110 * Consider need to reallocate a fragment.
112 osize = fragroundup(fs, blkoff(fs, ip->i_size));
113 nsize = fragroundup(fs, size);
114 if (nsize <= osize) {
115 error = bread(vp, lbn, osize, NOCRED, &bp);
120 bp->b_blkno = fsbtodb(fs, nb);
122 /* Godmar thinks: this shouldn't happen w/o fragments */
123 printf("nsize %d(%d) > osize %d(%d) nb %d\n",
124 (int)nsize, (int)size, (int)osize,
125 (int)ip->i_size, (int)nb);
127 "ext2_balloc: Something is terribly wrong");
129 * please note there haven't been any changes from here on -
134 if (ip->i_size < (lbn + 1) * fs->e2fs_bsize)
135 nsize = fragroundup(fs, size);
137 nsize = fs->e2fs_bsize;
139 error = ext2_alloc(ip, lbn,
140 ext2_blkpref(ip, lbn, (int)lbn, &ip->i_db[0], 0),
144 bp = getblk(vp, lbn, nsize, 0, 0, 0);
145 bp->b_blkno = fsbtodb(fs, newb);
146 if (flags & B_CLRBUF)
149 ip->i_db[lbn] = dbtofsb(fs, bp->b_blkno);
150 ip->i_flag |= IN_CHANGE | IN_UPDATE;
155 * Determine the number of levels of indirection.
158 if ((error = ext2_getlbns(vp, lbn, indirs, &num)) != 0)
162 panic ("ext2_balloc: ext2_getlbns returned indirect block");
165 * Fetch the first indirect block allocating if necessary.
168 nb = ip->i_ib[indirs[0].in_off];
171 pref = ext2_blkpref(ip, lbn, indirs[0].in_off +
172 EXT2_NDIR_BLOCKS, &ip->i_db[0], 0);
173 if ((error = ext2_alloc(ip, lbn, pref,
174 (int)fs->e2fs_bsize, cred, &newb)))
177 bp = getblk(vp, indirs[1].in_lbn, fs->e2fs_bsize, 0, 0, 0);
178 bp->b_blkno = fsbtodb(fs, newb);
181 * Write synchronously so that indirect blocks
182 * never point at garbage.
184 if ((error = bwrite(bp)) != 0) {
185 ext2_blkfree(ip, nb, fs->e2fs_bsize);
188 ip->i_ib[indirs[0].in_off] = newb;
189 ip->i_flag |= IN_CHANGE | IN_UPDATE;
192 * Fetch through the indirect blocks, allocating as necessary.
196 indirs[i].in_lbn, (int)fs->e2fs_bsize, NOCRED, &bp);
201 bap = (int32_t *)bp->b_data;
202 nb = bap[indirs[i].in_off];
212 pref = ext2_blkpref(ip, lbn, indirs[i].in_off, bap,
214 error = ext2_alloc(ip, lbn, pref, (int)fs->e2fs_bsize, cred, &newb);
220 nbp = getblk(vp, indirs[i].in_lbn, fs->e2fs_bsize, 0, 0, 0);
221 nbp->b_blkno = fsbtodb(fs, nb);
224 * Write synchronously so that indirect blocks
225 * never point at garbage.
227 if ((error = bwrite(nbp)) != 0) {
228 ext2_blkfree(ip, nb, fs->e2fs_bsize);
233 bap[indirs[i - 1].in_off] = nb;
235 * If required, write synchronously, otherwise use
238 if (flags & B_SYNC) {
241 if (bp->b_bufsize == fs->e2fs_bsize)
242 bp->b_flags |= B_CLUSTEROK;
247 * Get the data block, allocating if necessary.
251 pref = ext2_blkpref(ip, lbn, indirs[i].in_off, &bap[0],
253 if ((error = ext2_alloc(ip,
254 lbn, pref, (int)fs->e2fs_bsize, cred, &newb)) != 0) {
259 nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
260 nbp->b_blkno = fsbtodb(fs, nb);
261 if (flags & B_CLRBUF)
263 bap[indirs[i].in_off] = nb;
265 * If required, write synchronously, otherwise use
268 if (flags & B_SYNC) {
271 if (bp->b_bufsize == fs->e2fs_bsize)
272 bp->b_flags |= B_CLUSTEROK;
279 if (flags & B_CLRBUF) {
280 error = bread(vp, lbn, (int)fs->e2fs_bsize, NOCRED, &nbp);
286 nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
287 nbp->b_blkno = fsbtodb(fs, nb);