| /* |
| * 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 "config.h" |
| #include <stdio.h> |
| #if HAVE_UNISTD_H |
| #include <unistd.h> |
| #endif |
| #include <time.h> |
| #include <string.h> |
| #if HAVE_SYS_STAT_H |
| #include <sys/stat.h> |
| #endif |
| #if HAVE_SYS_TYPES_H |
| #include <sys/types.h> |
| #endif |
| |
| #include "ext2_fs.h" |
| #include "ext2fs.h" |
| |
| /* |
| * Clear the uninit block bitmap flag if necessary |
| */ |
| static void clear_block_uninit(ext2_filsys fs, dgrp_t group) |
| { |
| 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; |
| |
| /* uninit block bitmaps are now initialized in read_bitmaps() */ |
| |
| 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); |
| /* Mimics what the kernel does */ |
| ext2fs_bg_flags_clear(fs, group, EXT2_BG_BLOCK_UNINIT); |
| ext2fs_group_desc_csum_set(fs, group); |
| ext2fs_mark_ib_dirty(fs); |
| ext2fs_mark_super_dirty(fs); |
| } |
| |
| /* |
| * 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) |
| { |
| errcode_t retval; |
| blk64_t b = 0; |
| |
| 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; |
| goal &= ~EXT2FS_CLUSTER_MASK(fs); |
| |
| retval = ext2fs_find_first_zero_block_bitmap2(map, |
| goal, ext2fs_blocks_count(fs->super) - 1, &b); |
| if ((retval == ENOENT) && (goal != fs->super->s_first_data_block)) |
| retval = ext2fs_find_first_zero_block_bitmap2(map, |
| fs->super->s_first_data_block, goal - 1, &b); |
| if (retval == ENOENT) |
| return EXT2_ET_BLOCK_ALLOC_FAIL; |
| if (retval) |
| return retval; |
| |
| clear_block_uninit(fs, ext2fs_group_of_blk2(fs, b)); |
| *ret = b; |
| return 0; |
| } |
| |
| 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)) { |
| if (finish > start) |
| return EXT2_ET_BLOCK_ALLOC_FAIL; |
| 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; |
| } |