diff options
Diffstat (limited to '')
-rw-r--r-- | lib/ext2fs/initialize.c | 671 |
1 files changed, 671 insertions, 0 deletions
diff --git a/lib/ext2fs/initialize.c b/lib/ext2fs/initialize.c new file mode 100644 index 0000000..edd692b --- /dev/null +++ b/lib/ext2fs/initialize.c @@ -0,0 +1,671 @@ +/* + * initialize.c --- initialize a filesystem handle given superblock + * parameters. Used by mke2fs when initializing a filesystem. + * + * Copyright (C) 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> +#include <string.h> +#if HAVE_UNISTD_H +#include <unistd.h> +#endif +#include <fcntl.h> +#include <time.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" + +#ifndef O_BINARY +#define O_BINARY 0 +#endif + +#if defined(__linux__) && defined(EXT2_OS_LINUX) +#define CREATOR_OS EXT2_OS_LINUX +#else +#if defined(__GNU__) && defined(EXT2_OS_HURD) +#define CREATOR_OS EXT2_OS_HURD +#else +#if defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD) +#define CREATOR_OS EXT2_OS_FREEBSD +#else +#if defined(LITES) && defined(EXT2_OS_LITES) +#define CREATOR_OS EXT2_OS_LITES +#else +#define CREATOR_OS EXT2_OS_LINUX /* by default */ +#endif /* defined(LITES) && defined(EXT2_OS_LITES) */ +#endif /* defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD) */ +#endif /* defined(__GNU__) && defined(EXT2_OS_HURD) */ +#endif /* defined(__linux__) && defined(EXT2_OS_LINUX) */ + +/* + * Calculate the number of GDT blocks to reserve for online filesystem growth. + * The absolute maximum number of GDT blocks we can reserve is determined by + * the number of block pointers that can fit into a single block. + */ +static unsigned int calc_reserved_gdt_blocks(ext2_filsys fs) +{ + struct ext2_super_block *sb = fs->super; + unsigned long bpg = sb->s_blocks_per_group; + unsigned int gdpb = EXT2_DESC_PER_BLOCK(sb); + unsigned long max_blocks = 0xffffffff; + unsigned long rsv_groups; + unsigned int rsv_gdb; + + /* We set it at 1024x the current filesystem size, or + * the upper block count limit (2^32), whichever is lower. + */ + if (ext2fs_blocks_count(sb) < max_blocks / 1024) + max_blocks = ext2fs_blocks_count(sb) * 1024; + /* + * ext2fs_div64_ceil() is unnecessary because max_blocks is + * max _GDT_ blocks, which is limited to 32 bits. + */ + rsv_groups = ext2fs_div_ceil(max_blocks - sb->s_first_data_block, bpg); + rsv_gdb = ext2fs_div_ceil(rsv_groups, gdpb) - fs->desc_blocks; + if (rsv_gdb > EXT2_ADDR_PER_BLOCK(sb)) + rsv_gdb = EXT2_ADDR_PER_BLOCK(sb); +#ifdef RES_GDT_DEBUG + printf("max_blocks %lu, rsv_groups = %lu, rsv_gdb = %u\n", + max_blocks, rsv_groups, rsv_gdb); +#endif + + return rsv_gdb; +} + +errcode_t ext2fs_initialize(const char *name, int flags, + struct ext2_super_block *param, + io_manager manager, ext2_filsys *ret_fs) +{ + ext2_filsys fs; + errcode_t retval; + struct ext2_super_block *super; + unsigned int rem; + unsigned int overhead = 0; + unsigned int ipg; + dgrp_t i; + blk64_t free_blocks; + blk_t numblocks; + int rsv_gdt; + int csum_flag; + int bigalloc_flag; + int io_flags; + int has_bg; + unsigned reserved_inos; + char *buf = 0; + char c; + double reserved_ratio; + char *time_env; + + if (!param || !ext2fs_blocks_count(param)) + return EXT2_ET_INVALID_ARGUMENT; + + retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys), &fs); + if (retval) + return retval; + + memset(fs, 0, sizeof(struct struct_ext2_filsys)); + fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS; + fs->flags = flags | EXT2_FLAG_RW; + fs->umask = 022; + fs->default_bitmap_type = EXT2FS_BMAP64_RBTREE; +#ifdef WORDS_BIGENDIAN + fs->flags |= EXT2_FLAG_SWAP_BYTES; +#endif + + time_env = getenv("E2FSPROGS_FAKE_TIME"); + if (time_env) + fs->now = strtoul(time_env, NULL, 0); + + io_flags = IO_FLAG_RW; + if (flags & EXT2_FLAG_EXCLUSIVE) + io_flags |= IO_FLAG_EXCLUSIVE; + if (flags & EXT2_FLAG_DIRECT_IO) + io_flags |= IO_FLAG_DIRECT_IO; + io_flags |= O_BINARY; + retval = manager->open(name, io_flags, &fs->io); + if (retval) + goto cleanup; + fs->image_io = fs->io; + fs->io->app_data = fs; + retval = ext2fs_get_mem(strlen(name)+1, &fs->device_name); + if (retval) + goto cleanup; + + strcpy(fs->device_name, name); + retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &super); + if (retval) + goto cleanup; + fs->super = super; + + memset(super, 0, SUPERBLOCK_SIZE); + +#define set_field(field, default) (super->field = param->field ? \ + param->field : (default)) +#define assign_field(field) (super->field = param->field) + + super->s_magic = EXT2_SUPER_MAGIC; + super->s_state = EXT2_VALID_FS; + + bigalloc_flag = ext2fs_has_feature_bigalloc(param); + + assign_field(s_log_block_size); + + if (bigalloc_flag) { + set_field(s_log_cluster_size, super->s_log_block_size+4); + if (super->s_log_block_size > super->s_log_cluster_size) { + retval = EXT2_ET_INVALID_ARGUMENT; + goto cleanup; + } + } else + super->s_log_cluster_size = super->s_log_block_size; + + set_field(s_first_data_block, super->s_log_cluster_size ? 0 : 1); + set_field(s_max_mnt_count, 0); + set_field(s_errors, EXT2_ERRORS_DEFAULT); + set_field(s_feature_compat, 0); + set_field(s_feature_incompat, 0); + set_field(s_feature_ro_compat, 0); + set_field(s_default_mount_opts, 0); + set_field(s_first_meta_bg, 0); + set_field(s_raid_stride, 0); /* default stride size: 0 */ + set_field(s_raid_stripe_width, 0); /* default stripe width: 0 */ + set_field(s_log_groups_per_flex, 0); + set_field(s_flags, 0); + assign_field(s_backup_bgs[0]); + assign_field(s_backup_bgs[1]); + + assign_field(s_encoding); + assign_field(s_encoding_flags); + + if (ext2fs_has_feature_casefold(param)) + fs->encoding = ext2fs_load_nls_table(param->s_encoding); + + if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) { + retval = EXT2_ET_UNSUPP_FEATURE; + goto cleanup; + } + if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP) { + retval = EXT2_ET_RO_UNSUPP_FEATURE; + goto cleanup; + } + + set_field(s_rev_level, EXT2_GOOD_OLD_REV); + if (super->s_rev_level >= EXT2_DYNAMIC_REV) { + set_field(s_first_ino, EXT2_GOOD_OLD_FIRST_INO); + set_field(s_inode_size, EXT2_GOOD_OLD_INODE_SIZE); + if (super->s_inode_size >= sizeof(struct ext2_inode_large)) { + int extra_isize = sizeof(struct ext2_inode_large) - + EXT2_GOOD_OLD_INODE_SIZE; + set_field(s_min_extra_isize, extra_isize); + set_field(s_want_extra_isize, extra_isize); + } + } else { + super->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; + super->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE; + } + + set_field(s_checkinterval, 0); + super->s_mkfs_time = super->s_lastcheck = fs->now ? fs->now : time(NULL); + + super->s_creator_os = CREATOR_OS; + + fs->fragsize = fs->blocksize = EXT2_BLOCK_SIZE(super); + fs->cluster_ratio_bits = super->s_log_cluster_size - + super->s_log_block_size; + + if (bigalloc_flag) { + unsigned long long bpg; + + if (param->s_blocks_per_group && + param->s_clusters_per_group && + ((param->s_clusters_per_group * EXT2FS_CLUSTER_RATIO(fs)) != + param->s_blocks_per_group)) { + retval = EXT2_ET_INVALID_ARGUMENT; + goto cleanup; + } + if (param->s_clusters_per_group) + assign_field(s_clusters_per_group); + else if (param->s_blocks_per_group) + super->s_clusters_per_group = + param->s_blocks_per_group / + EXT2FS_CLUSTER_RATIO(fs); + else if (super->s_log_cluster_size + 15 < 32) + super->s_clusters_per_group = fs->blocksize * 8; + else + super->s_clusters_per_group = (fs->blocksize - 1) * 8; + if (super->s_clusters_per_group > EXT2_MAX_CLUSTERS_PER_GROUP(super)) + super->s_clusters_per_group = EXT2_MAX_CLUSTERS_PER_GROUP(super); + bpg = EXT2FS_C2B(fs, + (unsigned long long) super->s_clusters_per_group); + if (bpg >= (((unsigned long long) 1) << 32)) { + retval = EXT2_ET_INVALID_ARGUMENT; + goto cleanup; + } + super->s_blocks_per_group = bpg; + } else { + set_field(s_blocks_per_group, fs->blocksize * 8); + if (super->s_blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(super)) + super->s_blocks_per_group = EXT2_MAX_BLOCKS_PER_GROUP(super); + super->s_clusters_per_group = super->s_blocks_per_group; + } + + ext2fs_blocks_count_set(super, ext2fs_blocks_count(param) & + ~((blk64_t) EXT2FS_CLUSTER_MASK(fs))); + ext2fs_r_blocks_count_set(super, ext2fs_r_blocks_count(param)); + if (ext2fs_r_blocks_count(super) >= ext2fs_blocks_count(param)) { + retval = EXT2_ET_INVALID_ARGUMENT; + goto cleanup; + } + + set_field(s_mmp_update_interval, 0); + + /* + * If we're creating an external journal device, we don't need + * to bother with the rest. + */ + if (ext2fs_has_feature_journal_dev(super)) { + fs->group_desc_count = 0; + ext2fs_mark_super_dirty(fs); + *ret_fs = fs; + return 0; + } + +retry: + fs->group_desc_count = (dgrp_t) ext2fs_div64_ceil( + ext2fs_blocks_count(super) - super->s_first_data_block, + EXT2_BLOCKS_PER_GROUP(super)); + if (fs->group_desc_count == 0) { + retval = EXT2_ET_TOOSMALL; + goto cleanup; + } + + set_field(s_desc_size, + ext2fs_has_feature_64bit(super) ? + EXT2_MIN_DESC_SIZE_64BIT : 0); + + fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count, + EXT2_DESC_PER_BLOCK(super)); + + i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize; + + if (ext2fs_has_feature_64bit(super) && + (ext2fs_blocks_count(super) / i) >= (1ULL << 32)) + set_field(s_inodes_count, ~0U); + else + set_field(s_inodes_count, ext2fs_blocks_count(super) / i); + + /* + * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so + * that we have enough inodes for the filesystem(!) + */ + if (super->s_inodes_count < EXT2_FIRST_INODE(super)+1) + super->s_inodes_count = EXT2_FIRST_INODE(super)+1; + + /* + * There should be at least as many inodes as the user + * requested. Figure out how many inodes per group that + * should be. But make sure that we don't allocate more than + * one bitmap's worth of inodes each group. + */ + ipg = ext2fs_div_ceil(super->s_inodes_count, fs->group_desc_count); + if (ipg > fs->blocksize * 8) { + if (!bigalloc_flag && super->s_blocks_per_group >= 256) { + /* Try again with slightly different parameters */ + super->s_blocks_per_group -= 8; + ext2fs_blocks_count_set(super, + ext2fs_blocks_count(param)); + super->s_clusters_per_group = super->s_blocks_per_group; + goto retry; + } else { + retval = EXT2_ET_TOO_MANY_INODES; + goto cleanup; + } + } + + if (ipg > (unsigned) EXT2_MAX_INODES_PER_GROUP(super)) + ipg = EXT2_MAX_INODES_PER_GROUP(super); + +ipg_retry: + super->s_inodes_per_group = ipg; + + /* + * Make sure the number of inodes per group completely fills + * the inode table blocks in the descriptor. If not, add some + * additional inodes/group. Waste not, want not... + */ + fs->inode_blocks_per_group = (((super->s_inodes_per_group * + EXT2_INODE_SIZE(super)) + + EXT2_BLOCK_SIZE(super) - 1) / + EXT2_BLOCK_SIZE(super)); + super->s_inodes_per_group = ((fs->inode_blocks_per_group * + EXT2_BLOCK_SIZE(super)) / + EXT2_INODE_SIZE(super)); + /* + * Finally, make sure the number of inodes per group is a + * multiple of 8. This is needed to simplify the bitmap + * splicing code. + */ + if (super->s_inodes_per_group < 8) + super->s_inodes_per_group = 8; + super->s_inodes_per_group &= ~7; + fs->inode_blocks_per_group = (((super->s_inodes_per_group * + EXT2_INODE_SIZE(super)) + + EXT2_BLOCK_SIZE(super) - 1) / + EXT2_BLOCK_SIZE(super)); + + /* + * adjust inode count to reflect the adjusted inodes_per_group + */ + if ((__u64)super->s_inodes_per_group * fs->group_desc_count > ~0U) { + ipg--; + goto ipg_retry; + } + super->s_inodes_count = super->s_inodes_per_group * + fs->group_desc_count; + super->s_free_inodes_count = super->s_inodes_count; + + /* + * check the number of reserved group descriptor table blocks + */ + if (ext2fs_has_feature_resize_inode(super)) + rsv_gdt = calc_reserved_gdt_blocks(fs); + else + rsv_gdt = 0; + set_field(s_reserved_gdt_blocks, rsv_gdt); + if (super->s_reserved_gdt_blocks > EXT2_ADDR_PER_BLOCK(super)) { + retval = EXT2_ET_RES_GDT_BLOCKS; + goto cleanup; + } + /* Enable meta_bg if we'd lose more than 3/4 of a BG to GDT blocks. */ + if (super->s_reserved_gdt_blocks + fs->desc_blocks > + super->s_blocks_per_group * 3 / 4) { + ext2fs_set_feature_meta_bg(fs->super); + ext2fs_clear_feature_resize_inode(fs->super); + set_field(s_reserved_gdt_blocks, 0); + } + + /* + * Calculate the maximum number of bookkeeping blocks per + * group. It includes the superblock, the block group + * descriptors, the block bitmap, the inode bitmap, the inode + * table, and the reserved gdt blocks. + */ + overhead = (int) (3 + fs->inode_blocks_per_group + + super->s_reserved_gdt_blocks); + + if (ext2fs_has_feature_meta_bg(fs->super)) + overhead++; + else + overhead += fs->desc_blocks; + + /* This can only happen if the user requested too many inodes */ + if (overhead > super->s_blocks_per_group) { + retval = EXT2_ET_TOO_MANY_INODES; + goto cleanup; + } + + /* + * See if the last group is big enough to support the + * necessary data structures. If not, we need to get rid of + * it. We need to recalculate the overhead for the last block + * group, since it might or might not have a superblock + * backup. + */ + overhead = (int) (2 + fs->inode_blocks_per_group); + has_bg = 0; + if (ext2fs_has_feature_sparse_super2(super)) { + /* + * We have to do this manually since + * super->s_backup_bgs hasn't been set up yet. + */ + if (fs->group_desc_count == 2) + has_bg = param->s_backup_bgs[0] != 0; + else + has_bg = param->s_backup_bgs[1] != 0; + } else + has_bg = ext2fs_bg_has_super(fs, fs->group_desc_count - 1); + if (has_bg) + overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks; + rem = ((ext2fs_blocks_count(super) - super->s_first_data_block) % + super->s_blocks_per_group); + if ((fs->group_desc_count == 1) && rem && (rem < overhead)) { + retval = EXT2_ET_TOOSMALL; + goto cleanup; + } + if (rem && (rem < overhead+50)) { + ext2fs_blocks_count_set(super, ext2fs_blocks_count(super) - + rem); + /* + * If blocks count is changed, we need to recalculate + * reserved blocks count not to exceed 50%. + */ + reserved_ratio = 100.0 * ext2fs_r_blocks_count(param) / + ext2fs_blocks_count(param); + ext2fs_r_blocks_count_set(super, reserved_ratio * + ext2fs_blocks_count(super) / 100.0); + + goto retry; + } + + /* + * At this point we know how big the filesystem will be. So + * we can do any and all allocations that depend on the block + * count. + */ + + /* Set up the locations of the backup superblocks */ + if (ext2fs_has_feature_sparse_super2(super)) { + if (super->s_backup_bgs[0] >= fs->group_desc_count) + super->s_backup_bgs[0] = fs->group_desc_count - 1; + if (super->s_backup_bgs[1] >= fs->group_desc_count) + super->s_backup_bgs[1] = fs->group_desc_count - 1; + if (super->s_backup_bgs[0] == super->s_backup_bgs[1]) + super->s_backup_bgs[1] = 0; + if (super->s_backup_bgs[0] > super->s_backup_bgs[1]) { + __u32 t = super->s_backup_bgs[0]; + super->s_backup_bgs[0] = super->s_backup_bgs[1]; + super->s_backup_bgs[1] = t; + } + } + + retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf); + if (retval) + goto cleanup; + + strcpy(buf, "block bitmap for "); + strcat(buf, fs->device_name); + retval = ext2fs_allocate_subcluster_bitmap(fs, buf, &fs->block_map); + if (retval) + goto cleanup; + + strcpy(buf, "inode bitmap for "); + strcat(buf, fs->device_name); + retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map); + if (retval) + goto cleanup; + + ext2fs_free_mem(&buf); + + retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize, + &fs->group_desc); + if (retval) + goto cleanup; + + memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize); + + /* + * Reserve the superblock and group descriptors for each + * group, and fill in the correct group statistics for group. + * Note that although the block bitmap, inode bitmap, and + * inode table have not been allocated (and in fact won't be + * by this routine), they are accounted for nevertheless. + * + * If FLEX_BG meta-data grouping is used, only account for the + * superblock and group descriptors (the inode tables and + * bitmaps will be accounted for when allocated). + */ + free_blocks = 0; + csum_flag = ext2fs_has_group_desc_csum(fs); + reserved_inos = super->s_first_ino; + for (i = 0; i < fs->group_desc_count; i++) { + /* + * Don't set the BLOCK_UNINIT group for the last group + * because the block bitmap needs to be padded. + */ + if (csum_flag) { + if (i != fs->group_desc_count - 1) + ext2fs_bg_flags_set(fs, i, + EXT2_BG_BLOCK_UNINIT); + ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT); + numblocks = super->s_inodes_per_group; + if (reserved_inos) { + if (numblocks > reserved_inos) { + numblocks -= reserved_inos; + reserved_inos = 0; + } else { + reserved_inos -= numblocks; + numblocks = 0; + } + } + ext2fs_bg_itable_unused_set(fs, i, numblocks); + } + numblocks = ext2fs_reserve_super_and_bgd(fs, i, fs->block_map); + if (fs->super->s_log_groups_per_flex) + numblocks += 2 + fs->inode_blocks_per_group; + + free_blocks += numblocks; + ext2fs_bg_free_blocks_count_set(fs, i, numblocks); + ext2fs_bg_free_inodes_count_set(fs, i, fs->super->s_inodes_per_group); + ext2fs_bg_used_dirs_count_set(fs, i, 0); + ext2fs_group_desc_csum_set(fs, i); + } + free_blocks &= ~EXT2FS_CLUSTER_MASK(fs); + ext2fs_free_blocks_count_set(super, free_blocks); + + c = (char) 255; + if (((int) c) == -1) { + super->s_flags |= EXT2_FLAGS_SIGNED_HASH; + } else { + super->s_flags |= EXT2_FLAGS_UNSIGNED_HASH; + } + + ext2fs_mark_super_dirty(fs); + ext2fs_mark_bb_dirty(fs); + ext2fs_mark_ib_dirty(fs); + + io_channel_set_blksize(fs->io, fs->blocksize); + + *ret_fs = fs; + return 0; +cleanup: + free(buf); + ext2fs_free(fs); + return retval; +} + +errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs, int super_only) +{ + blk64_t blk; + ext2_ino_t ino; + unsigned int group = 0; + unsigned int count = 0; + int total_free = 0; + int group_free = 0; + int last_allocated = 0; + int uninit; + + /* + * First calculate the block statistics + */ + uninit = 1; + for (blk = fs->super->s_first_data_block; + blk < ext2fs_blocks_count(fs->super); blk++) { + if (!ext2fs_fast_test_block_bitmap2(fs->block_map, blk)) { + group_free++; + total_free++; + } else { + uninit = 0; + } + count++; + if ((count == fs->super->s_blocks_per_group) || + (blk == ext2fs_blocks_count(fs->super)-1)) { + ext2fs_bg_free_blocks_count_set(fs, group, + group_free); + if (!super_only) { + if (uninit && blk != + ext2fs_blocks_count(fs->super) - 1) + ext2fs_bg_flags_set(fs, group, + EXT2_BG_BLOCK_UNINIT); + else + ext2fs_bg_flags_clear(fs, group, + EXT2_BG_BLOCK_UNINIT); + } + count = 0; + group_free = 0; + uninit = 1; + group++; + } + } + total_free = EXT2FS_C2B(fs, total_free); + ext2fs_free_blocks_count_set(fs->super, total_free); + + /* + * Next, calculate the inode statistics + */ + group_free = 0; + total_free = 0; + last_allocated = 0; + count = 0; + group = 0; + + /* Protect loop from wrap-around if s_inodes_count maxed */ + for (ino = 1; ino <= fs->super->s_inodes_count && ino > 0; ino++) { + if (!ext2fs_test_inode_bitmap2(fs->inode_map, ino)) { + group_free++; + total_free++; + } else { + last_allocated = ino; + } + count++; + if ((count == fs->super->s_inodes_per_group) || + (ino == fs->super->s_inodes_count)) { + if (!super_only) { + if (last_allocated) { + ext2fs_bg_flags_clear(fs, group, + EXT2_BG_INODE_UNINIT); + ext2fs_bg_itable_unused_set(fs, group, + fs->super->s_inodes_per_group - + (last_allocated % + fs->super->s_inodes_per_group)); + } else { + ext2fs_bg_flags_set(fs, group, + EXT2_BG_INODE_UNINIT); + ext2fs_bg_itable_unused_set(fs, group, + 0); + } + ext2fs_bg_free_inodes_count_set(fs, group, + group_free); + } + group++; + count = 0; + group_free = 0; + last_allocated = 0; + } + } + fs->super->s_free_inodes_count = total_free; + ext2fs_mark_super_dirty(fs); + return 0; +} |