/*
* openfs.c --- open an ext2 filesystem
- *
- * Copyright (C) 1993, 1994 Theodore Ts'o. This file may be redistributed
- * under the terms of the GNU Public License.
+ *
+ * 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>
#include <string.h>
+#if HAVE_UNISTD_H
#include <unistd.h>
-#include <stdlib.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
+#ifdef HAVE_ERRNO_H
+#include <errno.h>
+#endif
+
+#include "ext2_fs.h"
-#include <linux/ext2_fs.h>
#include "ext2fs.h"
+#include "e2image.h"
+
+blk64_t ext2fs_descriptor_block_loc2(ext2_filsys fs, blk64_t group_block,
+ dgrp_t i)
+{
+ int bg;
+ int has_super = 0;
+ blk64_t ret_blk;
+
+ if (!(fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) ||
+ (i < fs->super->s_first_meta_bg))
+ return (group_block + i + 1);
+
+ bg = EXT2_DESC_PER_BLOCK(fs->super) * i;
+ if (ext2fs_bg_has_super(fs, bg))
+ has_super = 1;
+ ret_blk = ext2fs_group_first_block2(fs, bg) + has_super;
+ /*
+ * If group_block is not the normal value, we're trying to use
+ * the backup group descriptors and superblock --- so use the
+ * alternate location of the second block group in the
+ * metablock group. Ideally we should be testing each bg
+ * descriptor block individually for correctness, but we don't
+ * have the infrastructure in place to do that.
+ */
+ if (group_block != fs->super->s_first_data_block &&
+ ((ret_blk + fs->super->s_blocks_per_group) <
+ ext2fs_blocks_count(fs->super)))
+ ret_blk += fs->super->s_blocks_per_group;
+ return ret_blk;
+}
+
+blk_t ext2fs_descriptor_block_loc(ext2_filsys fs, blk_t group_block, dgrp_t i)
+{
+ return ext2fs_descriptor_block_loc2(fs, group_block, i);
+}
+
+errcode_t ext2fs_open(const char *name, int flags, int superblock,
+ unsigned int block_size, io_manager manager,
+ ext2_filsys *ret_fs)
+{
+ return ext2fs_open2(name, 0, flags, superblock, block_size,
+ manager, ret_fs);
+}
/*
* Note: if superblock is non-zero, block-size must also be non-zero.
* Superblock and block_size can be zero to use the default size.
+ *
+ * Valid flags for ext2fs_open()
+ *
+ * EXT2_FLAG_RW - Open the filesystem for read/write.
+ * EXT2_FLAG_FORCE - Open the filesystem even if some of the
+ * features aren't supported.
+ * EXT2_FLAG_JOURNAL_DEV_OK - Open an ext3 journal device
+ * EXT2_FLAG_SKIP_MMP - Open without multi-mount protection check.
+ * EXT2_FLAG_64BITS - Allow 64-bit bitfields (needed for large
+ * filesystems)
*/
-errcode_t ext2fs_open(const char *name, int flags, int superblock,
- int block_size, io_manager manager, ext2_filsys *ret_fs)
+errcode_t ext2fs_open2(const char *name, const char *io_options,
+ int flags, int superblock,
+ unsigned int block_size, io_manager manager,
+ ext2_filsys *ret_fs)
{
ext2_filsys fs;
errcode_t retval;
- int i, group_block;
- char *dest;
-
+ unsigned long i, first_meta_bg;
+ __u32 features;
+ unsigned int blocks_per_group, io_flags;
+ blk64_t group_block, blk;
+ char *dest, *cp;
+#ifdef WORDS_BIGENDIAN
+ unsigned int groups_per_block;
+ struct ext2_group_desc *gdp;
+ int j;
+#endif
+
EXT2_CHECK_MAGIC(manager, EXT2_ET_MAGIC_IO_MANAGER);
-
- fs = (ext2_filsys) malloc(sizeof(struct struct_ext2_filsys));
- if (!fs)
- return ENOMEM;
-
+
+ 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;
- retval = manager->open(name, (flags & EXT2_FLAG_RW) ? IO_FLAG_RW : 0,
- &fs->io);
+ /* don't overwrite sb backups unless flag is explicitly cleared */
+ fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
+ fs->umask = 022;
+ retval = ext2fs_get_mem(strlen(name)+1, &fs->device_name);
if (retval)
goto cleanup;
- fs->device_name = malloc(strlen(name)+1);
- if (!fs->device_name) {
- retval = ENOMEM;
- goto cleanup;
- }
strcpy(fs->device_name, name);
- fs->super = malloc(SUPERBLOCK_SIZE);
- if (!fs->super) {
- retval = ENOMEM;
+ cp = strchr(fs->device_name, '?');
+ if (!io_options && cp) {
+ *cp++ = 0;
+ io_options = cp;
+ }
+
+ io_flags = 0;
+ if (flags & EXT2_FLAG_RW)
+ 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;
+ retval = manager->open(fs->device_name, io_flags, &fs->io);
+ if (retval)
+ goto cleanup;
+ if (io_options &&
+ (retval = io_channel_set_options(fs->io, io_options)))
+ goto cleanup;
+ fs->image_io = fs->io;
+ fs->io->app_data = fs;
+ retval = io_channel_alloc_buf(fs->io, -SUPERBLOCK_SIZE, &fs->super);
+ if (retval)
goto cleanup;
+ if (flags & EXT2_FLAG_IMAGE_FILE) {
+ retval = ext2fs_get_mem(sizeof(struct ext2_image_hdr),
+ &fs->image_header);
+ if (retval)
+ goto cleanup;
+ retval = io_channel_read_blk(fs->io, 0,
+ -(int)sizeof(struct ext2_image_hdr),
+ fs->image_header);
+ if (retval)
+ goto cleanup;
+ if (fs->image_header->magic_number != EXT2_ET_MAGIC_E2IMAGE)
+ return EXT2_ET_MAGIC_E2IMAGE;
+ superblock = 1;
+ block_size = fs->image_header->fs_blocksize;
}
/*
* superblock, then he/she must also specify the block size!
* Otherwise, read the master superblock located at offset
* SUPERBLOCK_OFFSET from the start of the partition.
+ *
+ * Note: we only save a backup copy of the superblock if we
+ * are reading the superblock from the primary superblock location.
*/
if (superblock) {
if (!block_size) {
- retval = EINVAL;
+ retval = EXT2_ET_INVALID_ARGUMENT;
goto cleanup;
}
io_channel_set_blksize(fs->io, block_size);
- group_block = superblock + 1;
+ group_block = superblock;
+ fs->orig_super = 0;
} else {
io_channel_set_blksize(fs->io, SUPERBLOCK_OFFSET);
superblock = 1;
group_block = 0;
+ retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &fs->orig_super);
+ if (retval)
+ goto cleanup;
}
retval = io_channel_read_blk(fs->io, superblock, -SUPERBLOCK_SIZE,
fs->super);
if (retval)
goto cleanup;
-
+ if (fs->orig_super)
+ memcpy(fs->orig_super, fs->super, SUPERBLOCK_SIZE);
+
+#ifdef WORDS_BIGENDIAN
+ fs->flags |= EXT2_FLAG_SWAP_BYTES;
+ ext2fs_swap_super(fs->super);
+#else
+ if (fs->flags & EXT2_FLAG_SWAP_BYTES) {
+ retval = EXT2_ET_UNIMPLEMENTED;
+ goto cleanup;
+ }
+#endif
+
if (fs->super->s_magic != EXT2_SUPER_MAGIC) {
retval = EXT2_ET_BAD_MAGIC;
goto cleanup;
}
-#ifdef EXT2_CURRENT_REV
if (fs->super->s_rev_level > EXT2_LIB_CURRENT_REV) {
retval = EXT2_ET_REV_TOO_HIGH;
goto cleanup;
}
+
+ /*
+ * Check for feature set incompatibility
+ */
+ if (!(flags & EXT2_FLAG_FORCE)) {
+ features = fs->super->s_feature_incompat;
+#ifdef EXT2_LIB_SOFTSUPP_INCOMPAT
+ if (flags & EXT2_FLAG_SOFTSUPP_FEATURES)
+ features &= ~EXT2_LIB_SOFTSUPP_INCOMPAT;
+#endif
+ if (features & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) {
+ retval = EXT2_ET_UNSUPP_FEATURE;
+ goto cleanup;
+ }
+
+ features = fs->super->s_feature_ro_compat;
+#ifdef EXT2_LIB_SOFTSUPP_RO_COMPAT
+ if (flags & EXT2_FLAG_SOFTSUPP_FEATURES)
+ features &= ~EXT2_LIB_SOFTSUPP_RO_COMPAT;
#endif
- fs->blocksize = EXT2_BLOCK_SIZE(fs->super);
- fs->fragsize = EXT2_FRAG_SIZE(fs->super);
- fs->inode_blocks_per_group = (fs->super->s_inodes_per_group /
- EXT2_INODES_PER_BLOCK(fs->super));
+ if ((flags & EXT2_FLAG_RW) &&
+ (features & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP)) {
+ retval = EXT2_ET_RO_UNSUPP_FEATURE;
+ goto cleanup;
+ }
+
+ if (!(flags & EXT2_FLAG_JOURNAL_DEV_OK) &&
+ (fs->super->s_feature_incompat &
+ EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)) {
+ retval = EXT2_ET_UNSUPP_FEATURE;
+ goto cleanup;
+ }
+ }
+
+ if ((fs->super->s_log_block_size + EXT2_MIN_BLOCK_LOG_SIZE) >
+ EXT2_MAX_BLOCK_LOG_SIZE) {
+ retval = EXT2_ET_CORRUPT_SUPERBLOCK;
+ goto cleanup;
+ }
+ if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+ EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
+ (fs->super->s_log_block_size != fs->super->s_log_cluster_size)) {
+ retval = EXT2_ET_CORRUPT_SUPERBLOCK;
+ goto cleanup;
+ }
+ fs->fragsize = fs->blocksize = EXT2_BLOCK_SIZE(fs->super);
+ if (EXT2_INODE_SIZE(fs->super) < EXT2_GOOD_OLD_INODE_SIZE) {
+ retval = EXT2_ET_CORRUPT_SUPERBLOCK;
+ goto cleanup;
+ }
+ fs->cluster_ratio_bits = fs->super->s_log_cluster_size -
+ fs->super->s_log_block_size;
+ if (EXT2_BLOCKS_PER_GROUP(fs->super) !=
+ EXT2_CLUSTERS_PER_GROUP(fs->super) << fs->cluster_ratio_bits) {
+ retval = EXT2_ET_CORRUPT_SUPERBLOCK;
+ goto cleanup;
+ }
+ fs->inode_blocks_per_group = ((EXT2_INODES_PER_GROUP(fs->super) *
+ EXT2_INODE_SIZE(fs->super) +
+ EXT2_BLOCK_SIZE(fs->super) - 1) /
+ EXT2_BLOCK_SIZE(fs->super));
if (block_size) {
if (block_size != fs->blocksize) {
retval = EXT2_ET_UNEXPECTED_BLOCK_SIZE;
* Set the blocksize to the filesystem's blocksize.
*/
io_channel_set_blksize(fs->io, fs->blocksize);
-
+
+ /*
+ * If this is an external journal device, don't try to read
+ * the group descriptors, because they're not there.
+ */
+ if (fs->super->s_feature_incompat &
+ EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
+ fs->group_desc_count = 0;
+ *ret_fs = fs;
+ return 0;
+ }
+
+ if (EXT2_INODES_PER_GROUP(fs->super) == 0) {
+ retval = EXT2_ET_CORRUPT_SUPERBLOCK;
+ goto cleanup;
+ }
+
/*
* Read group descriptors
*/
- fs->group_desc_count = (fs->super->s_blocks_count -
- fs->super->s_first_data_block +
- EXT2_BLOCKS_PER_GROUP(fs->super) - 1)
- / EXT2_BLOCKS_PER_GROUP(fs->super);
- fs->desc_blocks = (fs->group_desc_count +
- EXT2_DESC_PER_BLOCK(fs->super) - 1)
- / EXT2_DESC_PER_BLOCK(fs->super);
- fs->group_desc = malloc(fs->desc_blocks * fs->blocksize);
- if (!fs->group_desc) {
- retval = ENOMEM;
+ blocks_per_group = EXT2_BLOCKS_PER_GROUP(fs->super);
+ if (blocks_per_group == 0 ||
+ blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(fs->super) ||
+ fs->inode_blocks_per_group > EXT2_MAX_INODES_PER_GROUP(fs->super) ||
+ EXT2_DESC_PER_BLOCK(fs->super) == 0 ||
+ fs->super->s_first_data_block >= ext2fs_blocks_count(fs->super)) {
+ retval = EXT2_ET_CORRUPT_SUPERBLOCK;
goto cleanup;
}
+ fs->group_desc_count = ext2fs_div64_ceil(ext2fs_blocks_count(fs->super) -
+ fs->super->s_first_data_block,
+ blocks_per_group);
+ if (fs->group_desc_count * EXT2_INODES_PER_GROUP(fs->super) !=
+ fs->super->s_inodes_count) {
+ retval = EXT2_ET_CORRUPT_SUPERBLOCK;
+ goto cleanup;
+ }
+ fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
+ EXT2_DESC_PER_BLOCK(fs->super));
+ retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize,
+ &fs->group_desc);
+ if (retval)
+ goto cleanup;
if (!group_block)
- group_block = fs->super->s_first_data_block + 1;
+ group_block = fs->super->s_first_data_block;
+ if (group_block == 0 && fs->blocksize == 1024)
+ group_block = 1; /* Deal with 1024 blocksize && bigalloc */
dest = (char *) fs->group_desc;
- for (i=0 ; i < fs->desc_blocks; i++) {
- retval = io_channel_read_blk(fs->io, group_block, 1, dest);
+#ifdef WORDS_BIGENDIAN
+ groups_per_block = EXT2_DESC_PER_BLOCK(fs->super);
+#endif
+ if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
+ first_meta_bg = fs->super->s_first_meta_bg;
+ else
+ first_meta_bg = fs->desc_blocks;
+ if (first_meta_bg) {
+ retval = io_channel_read_blk(fs->io, group_block+1,
+ first_meta_bg, dest);
+ if (retval)
+ goto cleanup;
+#ifdef WORDS_BIGENDIAN
+ gdp = (struct ext2_group_desc *) dest;
+ for (j=0; j < groups_per_block*first_meta_bg; j++) {
+ gdp = ext2fs_group_desc(fs, fs->group_desc, j);
+ ext2fs_swap_group_desc2(fs, gdp);
+ }
+#endif
+ dest += fs->blocksize*first_meta_bg;
+ }
+ for (i=first_meta_bg ; i < fs->desc_blocks; i++) {
+ blk = ext2fs_descriptor_block_loc2(fs, group_block, i);
+ retval = io_channel_read_blk64(fs->io, blk, 1, dest);
if (retval)
goto cleanup;
- group_block++;
+#ifdef WORDS_BIGENDIAN
+ for (j=0; j < groups_per_block; j++) {
+ gdp = ext2fs_group_desc(fs, fs->group_desc,
+ i * groups_per_block + j);
+ ext2fs_swap_group_desc2(fs, gdp);
+ }
+#endif
dest += fs->blocksize;
}
+ fs->stride = fs->super->s_raid_stride;
+
+ /*
+ * If recovery is from backup superblock, Clear _UNININT flags &
+ * reset bg_itable_unused to zero
+ */
+ if (superblock > 1 && EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+ EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
+ dgrp_t group;
+
+ for (group = 0; group < fs->group_desc_count; group++) {
+ ext2fs_bg_flags_clear(fs, group, EXT2_BG_BLOCK_UNINIT);
+ ext2fs_bg_flags_clear(fs, group, EXT2_BG_INODE_UNINIT);
+ ext2fs_bg_itable_unused_set(fs, group, 0);
+ /* The checksum will be reset later, but fix it here
+ * anyway to avoid printing a lot of spurious errors. */
+ ext2fs_group_desc_csum_set(fs, group);
+ }
+ if (fs->flags & EXT2_FLAG_RW)
+ ext2fs_mark_super_dirty(fs);
+ }
+
+ if ((fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_MMP) &&
+ !(flags & EXT2_FLAG_SKIP_MMP) &&
+ (flags & (EXT2_FLAG_RW | EXT2_FLAG_EXCLUSIVE))) {
+ retval = ext2fs_mmp_start(fs);
+ if (retval) {
+ fs->flags |= EXT2_FLAG_SKIP_MMP; /* just do cleanup */
+ ext2fs_mmp_stop(fs);
+ goto cleanup;
+ }
+ }
+
+ fs->flags &= ~EXT2_FLAG_NOFREE_ON_ERROR;
*ret_fs = fs;
+
return 0;
cleanup:
- ext2fs_free(fs);
+ if (flags & EXT2_FLAG_NOFREE_ON_ERROR)
+ *ret_fs = fs;
+ else
+ ext2fs_free(fs);
return retval;
}
+/*
+ * Set/get the filesystem data I/O channel.
+ *
+ * These functions are only valid if EXT2_FLAG_IMAGE_FILE is true.
+ */
+errcode_t ext2fs_get_data_io(ext2_filsys fs, io_channel *old_io)
+{
+ if ((fs->flags & EXT2_FLAG_IMAGE_FILE) == 0)
+ return EXT2_ET_NOT_IMAGE_FILE;
+ if (old_io) {
+ *old_io = (fs->image_io == fs->io) ? 0 : fs->io;
+ }
+ return 0;
+}
+
+errcode_t ext2fs_set_data_io(ext2_filsys fs, io_channel new_io)
+{
+ if ((fs->flags & EXT2_FLAG_IMAGE_FILE) == 0)
+ return EXT2_ET_NOT_IMAGE_FILE;
+ fs->io = new_io ? new_io : fs->image_io;
+ return 0;
+}
+
+errcode_t ext2fs_rewrite_to_io(ext2_filsys fs, io_channel new_io)
+{
+ if ((fs->flags & EXT2_FLAG_IMAGE_FILE) == 0)
+ return EXT2_ET_NOT_IMAGE_FILE;
+ fs->io = fs->image_io = new_io;
+ fs->flags |= EXT2_FLAG_DIRTY | EXT2_FLAG_RW |
+ EXT2_FLAG_BB_DIRTY | EXT2_FLAG_IB_DIRTY;
+ fs->flags &= ~EXT2_FLAG_IMAGE_FILE;
+ return 0;
+}