1/* vi: set sw=4 ts=4: */ 2/* 3 * alloc.c --- allocate new inodes, blocks for ext2fs 4 * 5 * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o. 6 * 7 * %Begin-Header% 8 * This file may be redistributed under the terms of the GNU Public 9 * License. 10 * %End-Header% 11 * 12 */ 13 14#include <stdio.h> 15#if HAVE_UNISTD_H 16#include <unistd.h> 17#endif 18#include <time.h> 19#include <string.h> 20#if HAVE_SYS_STAT_H 21#include <sys/stat.h> 22#endif 23#if HAVE_SYS_TYPES_H 24#include <sys/types.h> 25#endif 26 27#include "ext2_fs.h" 28#include "ext2fs.h" 29 30/* 31 * Right now, just search forward from the parent directory's block 32 * group to find the next free inode. 33 * 34 * Should have a special policy for directories. 35 */ 36errcode_t ext2fs_new_inode(ext2_filsys fs, ext2_ino_t dir, 37 int mode EXT2FS_ATTR((unused)), 38 ext2fs_inode_bitmap map, ext2_ino_t *ret) 39{ 40 ext2_ino_t dir_group = 0; 41 ext2_ino_t i; 42 ext2_ino_t start_inode; 43 44 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 45 46 if (!map) 47 map = fs->inode_map; 48 if (!map) 49 return EXT2_ET_NO_INODE_BITMAP; 50 51 if (dir > 0) 52 dir_group = (dir - 1) / EXT2_INODES_PER_GROUP(fs->super); 53 54 start_inode = (dir_group * EXT2_INODES_PER_GROUP(fs->super)) + 1; 55 if (start_inode < EXT2_FIRST_INODE(fs->super)) 56 start_inode = EXT2_FIRST_INODE(fs->super); 57 i = start_inode; 58 59 do { 60 if (!ext2fs_fast_test_inode_bitmap(map, i)) 61 break; 62 i++; 63 if (i > fs->super->s_inodes_count) 64 i = EXT2_FIRST_INODE(fs->super); 65 } while (i != start_inode); 66 67 if (ext2fs_test_inode_bitmap(map, i)) 68 return EXT2_ET_INODE_ALLOC_FAIL; 69 *ret = i; 70 return 0; 71} 72 73/* 74 * Stupid algorithm --- we now just search forward starting from the 75 * goal. Should put in a smarter one someday.... 76 */ 77errcode_t ext2fs_new_block(ext2_filsys fs, blk_t goal, 78 ext2fs_block_bitmap map, blk_t *ret) 79{ 80 blk_t i; 81 82 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 83 84 if (!map) 85 map = fs->block_map; 86 if (!map) 87 return EXT2_ET_NO_BLOCK_BITMAP; 88 if (!goal || (goal >= fs->super->s_blocks_count)) 89 goal = fs->super->s_first_data_block; 90 i = goal; 91 do { 92 if (!ext2fs_fast_test_block_bitmap(map, i)) { 93 *ret = i; 94 return 0; 95 } 96 i++; 97 if (i >= fs->super->s_blocks_count) 98 i = fs->super->s_first_data_block; 99 } while (i != goal); 100 return EXT2_ET_BLOCK_ALLOC_FAIL; 101} 102 103/* 104 * This function zeros out the allocated block, and updates all of the 105 * appropriate filesystem records. 106 */ 107errcode_t ext2fs_alloc_block(ext2_filsys fs, blk_t goal, 108 char *block_buf, blk_t *ret) 109{ 110 errcode_t retval; 111 blk_t block; 112 char *buf = NULL; 113 114 if (!block_buf) { 115 retval = ext2fs_get_mem(fs->blocksize, &buf); 116 if (retval) 117 return retval; 118 block_buf = buf; 119 } 120 memset(block_buf, 0, fs->blocksize); 121 122 if (!fs->block_map) { 123 retval = ext2fs_read_block_bitmap(fs); 124 if (retval) 125 goto fail; 126 } 127 128 retval = ext2fs_new_block(fs, goal, 0, &block); 129 if (retval) 130 goto fail; 131 132 retval = io_channel_write_blk(fs->io, block, 1, block_buf); 133 if (retval) 134 goto fail; 135 136 ext2fs_block_alloc_stats(fs, block, +1); 137 *ret = block; 138 return 0; 139 140fail: 141 if (buf) 142 ext2fs_free_mem(&buf); 143 return retval; 144} 145 146errcode_t ext2fs_get_free_blocks(ext2_filsys fs, blk_t start, blk_t finish, 147 int num, ext2fs_block_bitmap map, blk_t *ret) 148{ 149 blk_t b = start; 150 151 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 152 153 if (!map) 154 map = fs->block_map; 155 if (!map) 156 return EXT2_ET_NO_BLOCK_BITMAP; 157 if (!b) 158 b = fs->super->s_first_data_block; 159 if (!finish) 160 finish = start; 161 if (!num) 162 num = 1; 163 do { 164 if (b+num-1 > fs->super->s_blocks_count) 165 b = fs->super->s_first_data_block; 166 if (ext2fs_fast_test_block_bitmap_range(map, b, num)) { 167 *ret = b; 168 return 0; 169 } 170 b++; 171 } while (b != finish); 172 return EXT2_ET_BLOCK_ALLOC_FAIL; 173} 174 175