+ switch ((int)fs->fs_optim) {
+ case FS_OPTSPACE:
+ /*
+ * Allocate an exact sized fragment. Although this makes
+ * best use of space, we will waste time relocating it if
+ * the file continues to grow. If the fragmentation is
+ * less than half of the minimum free reserve, we choose
+ * to begin optimizing for time.
+ */
+ request = nsize;
+ if (fs->fs_minfree < 5 ||
+ fs->fs_cstotal.cs_nffree >
+ fs->fs_dsize * fs->fs_minfree / (2 * 100))
+ break;
+ log(LOG_NOTICE, "%s: optimization changed from SPACE to TIME\n",
+ fs->fs_fsmnt);
+ fs->fs_optim = FS_OPTTIME;
+ break;
+ case FS_OPTTIME:
+ /*
+ * At this point we have discovered a file that is trying to
+ * grow a small fragment to a larger fragment. To save time,
+ * we allocate a full sized block, then free the unused portion.
+ * If the file continues to grow, the `ffs_fragextend' call
+ * above will be able to grow it in place without further
+ * copying. If aberrant programs cause disk fragmentation to
+ * grow within 2% of the free reserve, we choose to begin
+ * optimizing for space.
+ */
+ request = fs->fs_bsize;
+ if (fs->fs_cstotal.cs_nffree <
+ fs->fs_dsize * (fs->fs_minfree - 2) / 100)
+ break;
+ log(LOG_NOTICE, "%s: optimization changed from TIME to SPACE\n",
+ fs->fs_fsmnt);
+ fs->fs_optim = FS_OPTSPACE;
+ break;
+ default:
+ printf("dev = 0x%x, optim = %d, fs = %s\n",
+ ip->i_dev, fs->fs_optim, fs->fs_fsmnt);
+ panic("ffs_realloccg: bad optim");
+ /* NOTREACHED */
+ }
+ bno = (daddr_t)ffs_hashalloc(ip, cg, (long)bpref, request,
+ (u_long (*)())ffs_alloccg);