- obp = bread(dev, bprev, osize);
- bp = getblk(dev, bno, nsize);
- cp = bp->b_un.b_addr;
- bp->b_un.b_addr = obp->b_un.b_addr;
- obp->b_un.b_addr = cp;
- obp->b_flags |= B_INVAL;
- brelse(obp);
- fre(dev, bprev, osize);
- blkclr(bp->b_un.b_addr + osize, nsize - osize);
- return(bp);
+ 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);
+ if (bno > 0) {
+#ifdef SECSIZE
+ obp = bread(ip->i_dev, fsbtodb(fs, bprev), osize,
+ fs->fs_dbsize);
+#else SECSIZE
+ count = howmany(osize, CLBYTES);
+ for (i = 0; i < count; i++)
+#ifdef SECSIZE
+ munhash(ip->i_dev, bn + i * CLBYTES / fs->fs_dbsize);
+#else SECSIZE
+ munhash(ip->i_dev, bn + i * CLBYTES / DEV_BSIZE);
+#endif SECSIZE
+ ffs_blkfree(ip, bprev, (long)osize);
+ if (nsize < request)
+ ffs_blkfree(ip, bno + numfrags(fs, nsize),
+ (long)(request - nsize));
+ ip->i_blocks += btodb(nsize - osize);
+ ip->i_flag |= IUPD|ICHG;
+ allocbuf(bp, nsize);
+ bp->b_flags |= B_DONE;
+ bzero(bp->b_un.b_addr + osize, (unsigned)nsize - osize);
+ *bpp = bp;
+ return (0);