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/mount.h>
45 #include <sys/vnode.h>
47 #include <fs/ext2fs/fs.h>
48 #include <fs/ext2fs/inode.h>
49 #include <fs/ext2fs/ext2fs.h>
50 #include <fs/ext2fs/ext2_dinode.h>
51 #include <fs/ext2fs/ext2_extern.h>
52 #include <fs/ext2fs/ext2_mount.h>
55 * Balloc defines the structure of filesystem storage
56 * by allocating the physical blocks on a device given
57 * the inode and the logical block number in a file.
60 ext2_balloc(struct inode *ip, e2fs_lbn_t lbn, int size, struct ucred *cred,
61 struct buf **bpp, int flags)
64 struct ext2mount *ump;
66 struct vnode *vp = ITOV(ip);
67 struct indir indirs[EXT2_NIADDR + 2];
68 e4fs_daddr_t nb, newb;
69 e2fs_daddr_t *bap, pref;
70 int osize, nsize, num, i, error;
79 * check if this is a sequential block allocation.
80 * If so, increment next_alloc fields to allow ext2_blkpref
81 * to make a good guess
83 if (lbn == ip->i_next_alloc_block + 1) {
84 ip->i_next_alloc_block++;
85 ip->i_next_alloc_goal++;
88 * The first EXT2_NDADDR blocks are direct blocks
90 if (lbn < EXT2_NDADDR) {
93 * no new block is to be allocated, and no need to expand
96 if (nb != 0 && ip->i_size >= (lbn + 1) * fs->e2fs_bsize) {
97 error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &bp);
102 bp->b_blkno = fsbtodb(fs, nb);
108 * Consider need to reallocate a fragment.
110 osize = fragroundup(fs, blkoff(fs, ip->i_size));
111 nsize = fragroundup(fs, size);
112 if (nsize <= osize) {
113 error = bread(vp, lbn, osize, NOCRED, &bp);
118 bp->b_blkno = fsbtodb(fs, nb);
121 * Godmar thinks: this shouldn't happen w/o
124 printf("nsize %d(%d) > osize %d(%d) nb %d\n",
125 (int)nsize, (int)size, (int)osize,
126 (int)ip->i_size, (int)nb);
128 "ext2_balloc: Something is terribly wrong");
130 * please note there haven't been any changes from here on -
135 if (ip->i_size < (lbn + 1) * fs->e2fs_bsize)
136 nsize = fragroundup(fs, size);
138 nsize = fs->e2fs_bsize;
140 error = ext2_alloc(ip, lbn,
141 ext2_blkpref(ip, lbn, (int)lbn, &ip->i_db[0], 0),
145 bp = getblk(vp, lbn, nsize, 0, 0, 0);
146 bp->b_blkno = fsbtodb(fs, newb);
147 if (flags & BA_CLRBUF)
150 ip->i_db[lbn] = dbtofsb(fs, bp->b_blkno);
151 ip->i_flag |= IN_CHANGE | IN_UPDATE;
156 * Determine the number of levels of indirection.
159 if ((error = ext2_getlbns(vp, lbn, indirs, &num)) != 0)
163 panic("ext2_balloc: ext2_getlbns returned indirect block");
166 * Fetch the first indirect block allocating if necessary.
169 nb = ip->i_ib[indirs[0].in_off];
172 pref = ext2_blkpref(ip, lbn, indirs[0].in_off +
173 EXT2_NDIR_BLOCKS, &ip->i_db[0], 0);
174 if ((error = ext2_alloc(ip, lbn, pref, fs->e2fs_bsize, cred,
178 bp = getblk(vp, indirs[1].in_lbn, fs->e2fs_bsize, 0, 0, 0);
179 bp->b_blkno = fsbtodb(fs, newb);
182 * Write synchronously so that indirect blocks
183 * never point at garbage.
185 if ((error = bwrite(bp)) != 0) {
186 ext2_blkfree(ip, nb, fs->e2fs_bsize);
189 ip->i_ib[indirs[0].in_off] = newb;
190 ip->i_flag |= IN_CHANGE | IN_UPDATE;
193 * Fetch through the indirect blocks, allocating as necessary.
197 indirs[i].in_lbn, (int)fs->e2fs_bsize, NOCRED, &bp);
202 bap = (e2fs_daddr_t *)bp->b_data;
203 nb = bap[indirs[i].in_off];
213 pref = ext2_blkpref(ip, lbn, indirs[i].in_off, bap,
215 error = ext2_alloc(ip, lbn, pref, (int)fs->e2fs_bsize, cred, &newb);
221 nbp = getblk(vp, indirs[i].in_lbn, fs->e2fs_bsize, 0, 0, 0);
222 nbp->b_blkno = fsbtodb(fs, nb);
225 * Write synchronously so that indirect blocks
226 * never point at garbage.
228 if ((error = bwrite(nbp)) != 0) {
229 ext2_blkfree(ip, nb, fs->e2fs_bsize);
234 bap[indirs[i - 1].in_off] = nb;
236 * If required, write synchronously, otherwise use
239 if (flags & IO_SYNC) {
242 if (bp->b_bufsize == fs->e2fs_bsize)
243 bp->b_flags |= B_CLUSTEROK;
248 * Get the data block, allocating if necessary.
252 pref = ext2_blkpref(ip, lbn, indirs[i].in_off, &bap[0],
254 if ((error = ext2_alloc(ip,
255 lbn, pref, (int)fs->e2fs_bsize, cred, &newb)) != 0) {
260 nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
261 nbp->b_blkno = fsbtodb(fs, nb);
262 if (flags & BA_CLRBUF)
264 bap[indirs[i].in_off] = nb;
266 * If required, write synchronously, otherwise use
269 if (flags & IO_SYNC) {
272 if (bp->b_bufsize == fs->e2fs_bsize)
273 bp->b_flags |= B_CLUSTEROK;
280 if (flags & BA_CLRBUF) {
281 int seqcount = (flags & BA_SEQMASK) >> BA_SEQSHIFT;
283 if (seqcount && (vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
284 error = cluster_read(vp, ip->i_size, lbn,
285 (int)fs->e2fs_bsize, NOCRED,
286 MAXBSIZE, seqcount, 0, &nbp);
288 error = bread(vp, lbn, (int)fs->e2fs_bsize, NOCRED, &nbp);
295 nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
296 nbp->b_blkno = fsbtodb(fs, nb);