/* Calculation of various derived store fields Copyright (C) 1995, 1996 Free Software Foundation, Inc. Written by Miles Bader <miles@gnu.ai.mit.edu> This file is part of the GNU Hurd. The GNU Hurd is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. The GNU Hurd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include "store.h" /* Fills in the values of the various fields in STORE that are derivable from the set of runs & the block size. */ void _store_derive (struct store *store) { unsigned i; struct store_run *runs = store->runs; unsigned num_runs = store->num_runs; size_t bsize = store->block_size; /* BLOCK & SIZE */ store->blocks = 0; for (i = 0; i < num_runs; i++) { store->wrap_src += runs[i].length; if (runs[i].start >= 0) /* Not a hole */ store->blocks += runs[i].length; } if (store->end == 0) /* END not set; set it using the info from RUNS. */ store->end = store->wrap_src; else if (store->wrap_src < store->end) /* A wrapped disk! RUNS is repeated N times to reach END. Adjust BLOCKS to include all iterations. */ { size_t num_iters = store->end / store->wrap_src; off_t last_part_base = num_iters * store->wrap_src; store->blocks *= num_iters; for (i = 0; i < num_runs; i++) if (last_part_base + runs[i].length < store->end) { store->blocks += store->end - (last_part_base + runs[i].length); break; } else if (runs[i].start >= 0) store->blocks += runs[i].length; /* WRAP_DST must be set by the caller. */ } store->size = store->end * bsize; /* LOG2_BLOCK_SIZE */ store->log2_block_size = 0; while ((1 << store->log2_block_size) < bsize) store->log2_block_size++; if ((1 << store->log2_block_size) != bsize) store->log2_block_size = 0; /* LOG2_BLOCKS_PER_PAGE */ store->log2_blocks_per_page = 0; while ((bsize << store->log2_blocks_per_page) < vm_page_size) store->log2_blocks_per_page++; if ((bsize << store->log2_blocks_per_page) != vm_page_size) store->log2_blocks_per_page = 0; }