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-rw-r--r--e2fslib/initialize.c326
1 files changed, 326 insertions, 0 deletions
diff --git a/e2fslib/initialize.c b/e2fslib/initialize.c
new file mode 100644
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--- /dev/null
+++ b/e2fslib/initialize.c
@@ -0,0 +1,326 @@
+/*
+ * 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 Public
+ * License.
+ * %End-Header%
+ */
+
+#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"
+
+#if defined(__linux__) && defined(EXT2_OS_LINUX)
+#define CREATOR_OS EXT2_OS_LINUX
+#elif defined(__GNU__) && defined(EXT2_OS_HURD)
+#define CREATOR_OS EXT2_OS_HURD
+#elif defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD)
+#define CREATOR_OS EXT2_OS_FREEBSD
+#elif defined(LITES) && defined(EXT2_OS_LITES)
+#define CREATOR_OS EXT2_OS_LITES
+#else
+#define CREATOR_OS EXT2_OS_LINUX /* by default */
+#endif
+
+/*
+ * Note we override the kernel include file's idea of what the default
+ * check interval (never) should be. It's a good idea to check at
+ * least *occasionally*, specially since servers will never rarely get
+ * to reboot, since Linux is so robust these days. :-)
+ *
+ * 180 days (six months) seems like a good value.
+ */
+#ifdef EXT2_DFL_CHECKINTERVAL
+#undef EXT2_DFL_CHECKINTERVAL
+#endif
+#define EXT2_DFL_CHECKINTERVAL (86400L * 180L)
+
+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;
+ int frags_per_block;
+ int rem;
+ int overhead = 0;
+ blk_t group_block;
+ int i, j;
+ blk_t numblocks;
+ char *buf;
+
+ if (!param || !param->s_blocks_count)
+ return EXT2_ET_INVALID_ARGUMENT;
+
+ retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys),
+ (void **) &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;
+#ifdef WORDS_BIGENDIAN
+ fs->flags |= EXT2_FLAG_SWAP_BYTES;
+#endif
+ retval = manager->open(name, IO_FLAG_RW, &fs->io);
+ if (retval)
+ goto cleanup;
+ fs->io->app_data = fs;
+ retval = ext2fs_get_mem(strlen(name)+1, (void **) &fs->device_name);
+ if (retval)
+ goto cleanup;
+
+ strcpy(fs->device_name, name);
+ retval = ext2fs_get_mem(SUPERBLOCK_SIZE, (void **) &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))
+
+ super->s_magic = EXT2_SUPER_MAGIC;
+ super->s_state = EXT2_VALID_FS;
+
+ set_field(s_log_block_size, 0); /* default blocksize: 1024 bytes */
+ set_field(s_log_frag_size, 0); /* default fragsize: 1024 bytes */
+ set_field(s_first_data_block, super->s_log_block_size ? 0 : 1);
+ set_field(s_max_mnt_count, EXT2_DFL_MAX_MNT_COUNT);
+ 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);
+ if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP)
+ return EXT2_ET_UNSUPP_FEATURE;
+ if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP)
+ return EXT2_ET_RO_UNSUPP_FEATURE;
+
+ 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);
+ }
+
+ set_field(s_checkinterval, EXT2_DFL_CHECKINTERVAL);
+ super->s_lastcheck = time(NULL);
+
+ super->s_creator_os = CREATOR_OS;
+
+ fs->blocksize = EXT2_BLOCK_SIZE(super);
+ fs->fragsize = EXT2_FRAG_SIZE(super);
+ frags_per_block = fs->blocksize / fs->fragsize;
+
+ /* default: (fs->blocksize*8) blocks/group */
+ set_field(s_blocks_per_group, fs->blocksize*8);
+ super->s_frags_per_group = super->s_blocks_per_group * frags_per_block;
+
+ super->s_blocks_count = param->s_blocks_count;
+ super->s_r_blocks_count = param->s_r_blocks_count;
+ if (super->s_r_blocks_count >= param->s_blocks_count) {
+ retval = EXT2_ET_INVALID_ARGUMENT;
+ goto cleanup;
+ }
+
+ /*
+ * If we're creating an external journal device, we don't need
+ * to bother with the rest.
+ */
+ if (super->s_feature_incompat &
+ EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
+ fs->group_desc_count = 0;
+ ext2fs_mark_super_dirty(fs);
+ *ret_fs = fs;
+ return 0;
+ }
+
+retry:
+ fs->group_desc_count = (super->s_blocks_count -
+ super->s_first_data_block +
+ EXT2_BLOCKS_PER_GROUP(super) - 1)
+ / EXT2_BLOCKS_PER_GROUP(super);
+ if (fs->group_desc_count == 0)
+ return EXT2_ET_TOOSMALL;
+ fs->desc_blocks = (fs->group_desc_count +
+ EXT2_DESC_PER_BLOCK(super) - 1)
+ / EXT2_DESC_PER_BLOCK(super);
+
+ /* n.b., fs->blocksize is <= 4096 */
+ set_field(s_inodes_count, super->s_blocks_count/(4096/fs->blocksize));
+
+ /*
+ * 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
+ */
+ super->s_inodes_per_group = (super->s_inodes_count +
+ fs->group_desc_count - 1) /
+ fs->group_desc_count;
+ if (super->s_inodes_per_group > fs->blocksize*8)
+ super->s_inodes_per_group = fs->blocksize*8;
+
+ /*
+ * 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.
+ */
+ 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
+ */
+ super->s_inodes_count = super->s_inodes_per_group *
+ fs->group_desc_count;
+ super->s_free_inodes_count = super->s_inodes_count;
+
+ /*
+ * Overhead is the number of bookkeeping blocks per group. It
+ * includes the superblock backup, the group descriptor
+ * backups, the inode bitmap, the block bitmap, and the inode
+ * table.
+ *
+ * XXX Not all block groups need the descriptor blocks, but
+ * being clever is tricky...
+ */
+ overhead = (int) (3 + fs->desc_blocks + fs->inode_blocks_per_group);
+
+ /*
+ * See if the last group is big enough to support the
+ * necessary data structures. If not, we need to get rid of
+ * it.
+ */
+ rem = (int) ((super->s_blocks_count - super->s_first_data_block) %
+ super->s_blocks_per_group);
+ if ((fs->group_desc_count == 1) && rem && (rem < overhead))
+ return EXT2_ET_TOOSMALL;
+ if (rem && (rem < overhead+50)) {
+ super->s_blocks_count -= rem;
+ 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.
+ */
+
+ retval = ext2fs_get_mem(strlen(fs->device_name) + 80,
+ (void **) &buf);
+ if (retval)
+ goto cleanup;
+
+ sprintf(buf, "block bitmap for %s", fs->device_name);
+ retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map);
+ if (retval)
+ goto cleanup;
+
+ sprintf(buf, "inode bitmap for %s", fs->device_name);
+ retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
+ if (retval)
+ goto cleanup;
+
+ ext2fs_free_mem((void **) &buf);
+
+ retval = ext2fs_get_mem((size_t) fs->desc_blocks * fs->blocksize,
+ (void **) &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.
+ */
+ group_block = super->s_first_data_block;
+ super->s_free_blocks_count = 0;
+ for (i = 0; i < fs->group_desc_count; i++) {
+ if (i == fs->group_desc_count-1) {
+ numblocks = (fs->super->s_blocks_count -
+ fs->super->s_first_data_block) %
+ fs->super->s_blocks_per_group;
+ if (!numblocks)
+ numblocks = fs->super->s_blocks_per_group;
+ } else
+ numblocks = fs->super->s_blocks_per_group;
+
+ if (ext2fs_bg_has_super(fs, i)) {
+ for (j=0; j < fs->desc_blocks+1; j++)
+ ext2fs_mark_block_bitmap(fs->block_map,
+ group_block + j);
+ numblocks -= 1 + fs->desc_blocks;
+ }
+
+ numblocks -= 2 + fs->inode_blocks_per_group;
+
+ super->s_free_blocks_count += numblocks;
+ fs->group_desc[i].bg_free_blocks_count = numblocks;
+ fs->group_desc[i].bg_free_inodes_count =
+ fs->super->s_inodes_per_group;
+ fs->group_desc[i].bg_used_dirs_count = 0;
+
+ group_block += super->s_blocks_per_group;
+ }
+
+ 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:
+ ext2fs_free(fs);
+ return retval;
+}
+
+
+