1 /* 2 * alloc.c --- allocate new inodes, blocks for ext2fs 3 * 4 * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o. 5 * 6 * %Begin-Header% 7 * This file may be redistributed under the terms of the GNU Library 8 * General Public License, version 2. 9 * %End-Header% 10 */ 11 12 #include <stdio.h> 13 #if HAVE_UNISTD_H 14 #include <unistd.h> 15 #endif 16 #include <time.h> 17 #include <string.h> 18 #if HAVE_SYS_STAT_H 19 #include <sys/stat.h> 20 #endif 21 #if HAVE_SYS_TYPES_H 22 #include <sys/types.h> 23 #endif 24 25 #include "ext2_fs.h" 26 #include "ext2fs.h" 27 28 /* 29 * Check for uninit block bitmaps and deal with them appropriately 30 */ 31 static void check_block_uninit(ext2_filsys fs, ext2fs_block_bitmap map, 32 dgrp_t group) 33 { 34 blk_t i; 35 blk64_t blk, super_blk, old_desc_blk, new_desc_blk; 36 int old_desc_blocks; 37 38 if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super, 39 EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) || 40 !(ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT))) 41 return; 42 43 blk = ext2fs_group_first_block2(fs, group); 44 45 ext2fs_super_and_bgd_loc2(fs, group, &super_blk, 46 &old_desc_blk, &new_desc_blk, 0); 47 48 if (fs->super->s_feature_incompat & 49 EXT2_FEATURE_INCOMPAT_META_BG) 50 old_desc_blocks = fs->super->s_first_meta_bg; 51 else 52 old_desc_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks; 53 54 for (i=0; i < fs->super->s_blocks_per_group; i++, blk++) 55 ext2fs_fast_unmark_block_bitmap2(map, blk); 56 57 blk = ext2fs_group_first_block2(fs, group); 58 for (i=0; i < fs->super->s_blocks_per_group; i++, blk++) { 59 if ((blk == super_blk) || 60 (old_desc_blk && old_desc_blocks && 61 (blk >= old_desc_blk) && 62 (blk < old_desc_blk + old_desc_blocks)) || 63 (new_desc_blk && (blk == new_desc_blk)) || 64 (blk == ext2fs_block_bitmap_loc(fs, group)) || 65 (blk == ext2fs_inode_bitmap_loc(fs, group)) || 66 (blk >= ext2fs_inode_table_loc(fs, group) && 67 (blk < ext2fs_inode_table_loc(fs, group) 68 + fs->inode_blocks_per_group))) 69 ext2fs_fast_mark_block_bitmap2(map, blk); 70 } 71 ext2fs_bg_flags_clear(fs, group, EXT2_BG_BLOCK_UNINIT); 72 ext2fs_group_desc_csum_set(fs, group); 73 ext2fs_mark_super_dirty(fs); 74 ext2fs_mark_bb_dirty(fs); 75 } 76 77 /* 78 * Check for uninit inode bitmaps and deal with them appropriately 79 */ 80 static void check_inode_uninit(ext2_filsys fs, ext2fs_inode_bitmap map, 81 dgrp_t group) 82 { 83 ext2_ino_t i, ino; 84 85 if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super, 86 EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) || 87 !(ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT))) 88 return; 89 90 ino = (group * fs->super->s_inodes_per_group) + 1; 91 for (i=0; i < fs->super->s_inodes_per_group; i++, ino++) 92 ext2fs_fast_unmark_inode_bitmap2(map, ino); 93 94 ext2fs_bg_flags_clear(fs, group, EXT2_BG_INODE_UNINIT); 95 ext2fs_group_desc_csum_set(fs, group); 96 ext2fs_mark_ib_dirty(fs); 97 ext2fs_mark_super_dirty(fs); 98 check_block_uninit(fs, fs->block_map, group); 99 } 100 101 /* 102 * Right now, just search forward from the parent directory's block 103 * group to find the next free inode. 104 * 105 * Should have a special policy for directories. 106 */ 107 errcode_t ext2fs_new_inode(ext2_filsys fs, ext2_ino_t dir, 108 int mode EXT2FS_ATTR((unused)), 109 ext2fs_inode_bitmap map, ext2_ino_t *ret) 110 { 111 ext2_ino_t start_inode = 0; 112 ext2_ino_t i, ino_in_group, upto, first_zero; 113 errcode_t retval; 114 dgrp_t group; 115 116 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 117 118 if (!map) 119 map = fs->inode_map; 120 if (!map) 121 return EXT2_ET_NO_INODE_BITMAP; 122 123 if (dir > 0) { 124 group = (dir - 1) / EXT2_INODES_PER_GROUP(fs->super); 125 start_inode = (group * EXT2_INODES_PER_GROUP(fs->super)) + 1; 126 } 127 if (start_inode < EXT2_FIRST_INODE(fs->super)) 128 start_inode = EXT2_FIRST_INODE(fs->super); 129 if (start_inode > fs->super->s_inodes_count) 130 return EXT2_ET_INODE_ALLOC_FAIL; 131 i = start_inode; 132 do { 133 ino_in_group = (i - 1) % EXT2_INODES_PER_GROUP(fs->super); 134 group = (i - 1) / EXT2_INODES_PER_GROUP(fs->super); 135 136 check_inode_uninit(fs, map, group); 137 upto = i + (EXT2_INODES_PER_GROUP(fs->super) - ino_in_group); 138 if (i < start_inode && upto >= start_inode) 139 upto = start_inode - 1; 140 if (upto > fs->super->s_inodes_count) 141 upto = fs->super->s_inodes_count; 142 143 retval = ext2fs_find_first_zero_inode_bitmap2(map, i, upto, 144 &first_zero); 145 if (retval == 0) { 146 i = first_zero; 147 break; 148 } 149 if (retval != ENOENT) 150 return EXT2_ET_INODE_ALLOC_FAIL; 151 i = upto + 1; 152 if (i > fs->super->s_inodes_count) 153 i = EXT2_FIRST_INODE(fs->super); 154 } while (i != start_inode); 155 156 if (ext2fs_test_inode_bitmap2(map, i)) 157 return EXT2_ET_INODE_ALLOC_FAIL; 158 *ret = i; 159 return 0; 160 } 161 162 /* 163 * Stupid algorithm --- we now just search forward starting from the 164 * goal. Should put in a smarter one someday.... 165 */ 166 errcode_t ext2fs_new_block2(ext2_filsys fs, blk64_t goal, 167 ext2fs_block_bitmap map, blk64_t *ret) 168 { 169 blk64_t i; 170 int c_ratio; 171 172 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 173 174 if (!map) 175 map = fs->block_map; 176 if (!map) 177 return EXT2_ET_NO_BLOCK_BITMAP; 178 if (!goal || (goal >= ext2fs_blocks_count(fs->super))) 179 goal = fs->super->s_first_data_block; 180 i = goal; 181 c_ratio = 1 << ext2fs_get_bitmap_granularity(map); 182 if (c_ratio > 1) 183 goal &= ~EXT2FS_CLUSTER_MASK(fs); 184 check_block_uninit(fs, map, 185 (i - fs->super->s_first_data_block) / 186 EXT2_BLOCKS_PER_GROUP(fs->super)); 187 do { 188 if (((i - fs->super->s_first_data_block) % 189 EXT2_BLOCKS_PER_GROUP(fs->super)) == 0) 190 check_block_uninit(fs, map, 191 (i - fs->super->s_first_data_block) / 192 EXT2_BLOCKS_PER_GROUP(fs->super)); 193 194 if (!ext2fs_fast_test_block_bitmap2(map, i)) { 195 *ret = i; 196 return 0; 197 } 198 i = (i + c_ratio) & ~(c_ratio - 1); 199 if (i >= ext2fs_blocks_count(fs->super)) 200 i = fs->super->s_first_data_block; 201 } while (i != goal); 202 return EXT2_ET_BLOCK_ALLOC_FAIL; 203 } 204 205 errcode_t ext2fs_new_block(ext2_filsys fs, blk_t goal, 206 ext2fs_block_bitmap map, blk_t *ret) 207 { 208 errcode_t retval; 209 blk64_t val; 210 retval = ext2fs_new_block2(fs, goal, map, &val); 211 if (!retval) 212 *ret = (blk_t) val; 213 return retval; 214 } 215 216 /* 217 * This function zeros out the allocated block, and updates all of the 218 * appropriate filesystem records. 219 */ 220 errcode_t ext2fs_alloc_block2(ext2_filsys fs, blk64_t goal, 221 char *block_buf, blk64_t *ret) 222 { 223 errcode_t retval; 224 blk64_t block; 225 char *buf = 0; 226 227 if (!block_buf) { 228 retval = ext2fs_get_mem(fs->blocksize, &buf); 229 if (retval) 230 return retval; 231 block_buf = buf; 232 } 233 memset(block_buf, 0, fs->blocksize); 234 235 if (fs->get_alloc_block) { 236 retval = (fs->get_alloc_block)(fs, goal, &block); 237 if (retval) 238 goto fail; 239 } else { 240 if (!fs->block_map) { 241 retval = ext2fs_read_block_bitmap(fs); 242 if (retval) 243 goto fail; 244 } 245 246 retval = ext2fs_new_block2(fs, goal, 0, &block); 247 if (retval) 248 goto fail; 249 } 250 251 retval = io_channel_write_blk64(fs->io, block, 1, block_buf); 252 if (retval) 253 goto fail; 254 255 ext2fs_block_alloc_stats2(fs, block, +1); 256 *ret = block; 257 258 fail: 259 if (buf) 260 ext2fs_free_mem(&buf); 261 return retval; 262 } 263 264 errcode_t ext2fs_alloc_block(ext2_filsys fs, blk_t goal, 265 char *block_buf, blk_t *ret) 266 { 267 errcode_t retval; 268 blk64_t val; 269 retval = ext2fs_alloc_block2(fs, goal, block_buf, &val); 270 if (!retval) 271 *ret = (blk_t) val; 272 return retval; 273 } 274 275 errcode_t ext2fs_get_free_blocks2(ext2_filsys fs, blk64_t start, blk64_t finish, 276 int num, ext2fs_block_bitmap map, blk64_t *ret) 277 { 278 blk64_t b = start; 279 int c_ratio; 280 281 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 282 283 if (!map) 284 map = fs->block_map; 285 if (!map) 286 return EXT2_ET_NO_BLOCK_BITMAP; 287 if (!b) 288 b = fs->super->s_first_data_block; 289 if (!finish) 290 finish = start; 291 if (!num) 292 num = 1; 293 c_ratio = 1 << ext2fs_get_bitmap_granularity(map); 294 b &= ~(c_ratio - 1); 295 finish &= ~(c_ratio -1); 296 do { 297 if (b+num-1 > ext2fs_blocks_count(fs->super)) 298 b = fs->super->s_first_data_block; 299 if (ext2fs_fast_test_block_bitmap_range2(map, b, num)) { 300 *ret = b; 301 return 0; 302 } 303 b += c_ratio; 304 } while (b != finish); 305 return EXT2_ET_BLOCK_ALLOC_FAIL; 306 } 307 308 errcode_t ext2fs_get_free_blocks(ext2_filsys fs, blk_t start, blk_t finish, 309 int num, ext2fs_block_bitmap map, blk_t *ret) 310 { 311 errcode_t retval; 312 blk64_t val; 313 retval = ext2fs_get_free_blocks2(fs, start, finish, num, map, &val); 314 if(!retval) 315 *ret = (blk_t) val; 316 return retval; 317 } 318 319 void ext2fs_set_alloc_block_callback(ext2_filsys fs, 320 errcode_t (*func)(ext2_filsys fs, 321 blk64_t goal, 322 blk64_t *ret), 323 errcode_t (**old)(ext2_filsys fs, 324 blk64_t goal, 325 blk64_t *ret)) 326 { 327 if (!fs || fs->magic != EXT2_ET_MAGIC_EXT2FS_FILSYS) 328 return; 329 330 if (old) 331 *old = fs->get_alloc_block; 332 333 fs->get_alloc_block = func; 334 } 335
