/* * alloc.c --- allocate new inodes, blocks for ext2fs * * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o. * * %Begin-Header% * This file may be redistributed under the terms of the GNU Library * General Public License, version 2. * %End-Header% */ #include #if HAVE_UNISTD_H #include #endif #include #include #if HAVE_SYS_STAT_H #include #endif #if HAVE_SYS_TYPES_H #include #endif #include "ext2_fs.h" #include "ext2fs.h" /* * Check for uninit block bitmaps and deal with them appropriately */ static void check_block_uninit(ext2_filsys fs, ext2fs_block_bitmap map, dgrp_t group) { blk_t i; blk64_t blk, super_blk, old_desc_blk, new_desc_blk; int old_desc_blocks; if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) || !(ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT))) return; blk = ext2fs_group_first_block2(fs, group); ext2fs_super_and_bgd_loc2(fs, group, &super_blk, &old_desc_blk, &new_desc_blk, 0); if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) old_desc_blocks = fs->super->s_first_meta_bg; else old_desc_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks; for (i=0; i < fs->super->s_blocks_per_group; i++, blk++) ext2fs_fast_unmark_block_bitmap2(map, blk); blk = ext2fs_group_first_block2(fs, group); for (i=0; i < fs->super->s_blocks_per_group; i++, blk++) { if ((blk == super_blk) || (old_desc_blk && old_desc_blocks && (blk >= old_desc_blk) && (blk < old_desc_blk + old_desc_blocks)) || (new_desc_blk && (blk == new_desc_blk)) || (blk == ext2fs_block_bitmap_loc(fs, group)) || (blk == ext2fs_inode_bitmap_loc(fs, group)) || (blk >= ext2fs_inode_table_loc(fs, group) && (blk < ext2fs_inode_table_loc(fs, group) + fs->inode_blocks_per_group))) ext2fs_fast_mark_block_bitmap2(map, blk); } ext2fs_bg_flags_clear(fs, group, EXT2_BG_BLOCK_UNINIT); ext2fs_group_desc_csum_set(fs, group); ext2fs_mark_super_dirty(fs); ext2fs_mark_bb_dirty(fs); } /* * Check for uninit inode bitmaps and deal with them appropriately */ static void check_inode_uninit(ext2_filsys fs, ext2fs_inode_bitmap map, dgrp_t group) { ext2_ino_t i, ino; if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) || !(ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT))) return; ino = (group * fs->super->s_inodes_per_group) + 1; for (i=0; i < fs->super->s_inodes_per_group; i++, ino++) ext2fs_fast_unmark_inode_bitmap2(map, ino); ext2fs_bg_flags_clear(fs, group, EXT2_BG_INODE_UNINIT); ext2fs_group_desc_csum_set(fs, group); ext2fs_mark_ib_dirty(fs); ext2fs_mark_super_dirty(fs); check_block_uninit(fs, fs->block_map, group); } /* * Right now, just search forward from the parent directory's block * group to find the next free inode. * * Should have a special policy for directories. */ errcode_t ext2fs_new_inode(ext2_filsys fs, ext2_ino_t dir, int mode EXT2FS_ATTR((unused)), ext2fs_inode_bitmap map, ext2_ino_t *ret) { ext2_ino_t start_inode = 0; ext2_ino_t i, ino_in_group, upto, first_zero; errcode_t retval; dgrp_t group; EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); if (!map) map = fs->inode_map; if (!map) return EXT2_ET_NO_INODE_BITMAP; if (dir > 0) { group = (dir - 1) / EXT2_INODES_PER_GROUP(fs->super); start_inode = (group * EXT2_INODES_PER_GROUP(fs->super)) + 1; } if (start_inode < EXT2_FIRST_INODE(fs->super)) start_inode = EXT2_FIRST_INODE(fs->super); if (start_inode > fs->super->s_inodes_count) return EXT2_ET_INODE_ALLOC_FAIL; i = start_inode; do { ino_in_group = (i - 1) % EXT2_INODES_PER_GROUP(fs->super); group = (i - 1) / EXT2_INODES_PER_GROUP(fs->super); check_inode_uninit(fs, map, group); upto = i + (EXT2_INODES_PER_GROUP(fs->super) - ino_in_group); if (i < start_inode && upto >= start_inode) upto = start_inode - 1; if (upto > fs->super->s_inodes_count) upto = fs->super->s_inodes_count; retval = ext2fs_find_first_zero_inode_bitmap2(map, i, upto, &first_zero); if (retval == 0) { i = first_zero; break; } if (retval != ENOENT) return EXT2_ET_INODE_ALLOC_FAIL; i = upto + 1; if (i > fs->super->s_inodes_count) i = EXT2_FIRST_INODE(fs->super); } while (i != start_inode); if (ext2fs_test_inode_bitmap2(map, i)) return EXT2_ET_INODE_ALLOC_FAIL; *ret = i; return 0; } /* * Stupid algorithm --- we now just search forward starting from the * goal. Should put in a smarter one someday.... */ errcode_t ext2fs_new_block2(ext2_filsys fs, blk64_t goal, ext2fs_block_bitmap map, blk64_t *ret) { blk64_t i; int c_ratio; EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); if (!map) map = fs->block_map; if (!map) return EXT2_ET_NO_BLOCK_BITMAP; if (!goal || (goal >= ext2fs_blocks_count(fs->super))) goal = fs->super->s_first_data_block; i = goal; c_ratio = 1 << ext2fs_get_bitmap_granularity(map); if (c_ratio > 1) goal &= ~EXT2FS_CLUSTER_MASK(fs); check_block_uninit(fs, map, (i - fs->super->s_first_data_block) / EXT2_BLOCKS_PER_GROUP(fs->super)); do { if (((i - fs->super->s_first_data_block) % EXT2_BLOCKS_PER_GROUP(fs->super)) == 0) check_block_uninit(fs, map, (i - fs->super->s_first_data_block) / EXT2_BLOCKS_PER_GROUP(fs->super)); if (!ext2fs_fast_test_block_bitmap2(map, i)) { *ret = i; return 0; } i = (i + c_ratio) & ~(c_ratio - 1); if (i >= ext2fs_blocks_count(fs->super)) i = fs->super->s_first_data_block; } while (i != goal); return EXT2_ET_BLOCK_ALLOC_FAIL; } errcode_t ext2fs_new_block(ext2_filsys fs, blk_t goal, ext2fs_block_bitmap map, blk_t *ret) { errcode_t retval; blk64_t val; retval = ext2fs_new_block2(fs, goal, map, &val); if (!retval) *ret = (blk_t) val; return retval; } /* * This function zeros out the allocated block, and updates all of the * appropriate filesystem records. */ errcode_t ext2fs_alloc_block2(ext2_filsys fs, blk64_t goal, char *block_buf, blk64_t *ret) { errcode_t retval; blk64_t block; char *buf = 0; if (!block_buf) { retval = ext2fs_get_mem(fs->blocksize, &buf); if (retval) return retval; block_buf = buf; } memset(block_buf, 0, fs->blocksize); if (fs->get_alloc_block) { retval = (fs->get_alloc_block)(fs, goal, &block); if (retval) goto fail; } else { if (!fs->block_map) { retval = ext2fs_read_block_bitmap(fs); if (retval) goto fail; } retval = ext2fs_new_block2(fs, goal, 0, &block); if (retval) goto fail; } retval = io_channel_write_blk64(fs->io, block, 1, block_buf); if (retval) goto fail; ext2fs_block_alloc_stats2(fs, block, +1); *ret = block; fail: if (buf) ext2fs_free_mem(&buf); return retval; } errcode_t ext2fs_alloc_block(ext2_filsys fs, blk_t goal, char *block_buf, blk_t *ret) { errcode_t retval; blk64_t val; retval = ext2fs_alloc_block2(fs, goal, block_buf, &val); if (!retval) *ret = (blk_t) val; return retval; } errcode_t ext2fs_get_free_blocks2(ext2_filsys fs, blk64_t start, blk64_t finish, int num, ext2fs_block_bitmap map, blk64_t *ret) { blk64_t b = start; int c_ratio; EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); if (!map) map = fs->block_map; if (!map) return EXT2_ET_NO_BLOCK_BITMAP; if (!b) b = fs->super->s_first_data_block; if (!finish) finish = start; if (!num) num = 1; c_ratio = 1 << ext2fs_get_bitmap_granularity(map); b &= ~(c_ratio - 1); finish &= ~(c_ratio -1); do { if (b+num-1 > ext2fs_blocks_count(fs->super)) b = fs->super->s_first_data_block; if (ext2fs_fast_test_block_bitmap_range2(map, b, num)) { *ret = b; return 0; } b += c_ratio; } while (b != finish); return EXT2_ET_BLOCK_ALLOC_FAIL; } errcode_t ext2fs_get_free_blocks(ext2_filsys fs, blk_t start, blk_t finish, int num, ext2fs_block_bitmap map, blk_t *ret) { errcode_t retval; blk64_t val; retval = ext2fs_get_free_blocks2(fs, start, finish, num, map, &val); if(!retval) *ret = (blk_t) val; return retval; } void ext2fs_set_alloc_block_callback(ext2_filsys fs, errcode_t (*func)(ext2_filsys fs, blk64_t goal, blk64_t *ret), errcode_t (**old)(ext2_filsys fs, blk64_t goal, blk64_t *ret)) { if (!fs || fs->magic != EXT2_ET_MAGIC_EXT2FS_FILSYS) return; if (old) *old = fs->get_alloc_block; fs->get_alloc_block = func; }