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Mini Shell
Mini Shell
// Copyright (c) Veeam Software Group GmbH
#include "stdafx.h"
#ifdef PERSISTENT_CBT
#include "ext4_check.h"
#include "blk_util.h"
#include <linux/crc32.h>
#include <linux/buffer_head.h>
#define SECTION "ext4_chkfs"
#include "log_format.h"
// from vanilla kernel 2.6.32.9
/*
* Structure of the super block
*/
struct ext4_super_block {
/*00*/ __le32 s_inodes_count; /* Inodes count */
__le32 s_blocks_count_lo; /* Blocks count */
__le32 s_r_blocks_count_lo; /* Reserved blocks count */
__le32 s_free_blocks_count_lo; /* Free blocks count */
/*10*/ __le32 s_free_inodes_count; /* Free inodes count */
__le32 s_first_data_block; /* First Data Block */
__le32 s_log_block_size; /* Block size */
__le32 s_obso_log_frag_size; /* Obsoleted fragment size */
/*20*/ __le32 s_blocks_per_group; /* # Blocks per group */
__le32 s_obso_frags_per_group; /* Obsoleted fragments per group */
__le32 s_inodes_per_group; /* # Inodes per group */
__le32 s_mtime; /* Mount time */
/*30*/ __le32 s_wtime; /* Write time */
__le16 s_mnt_count; /* Mount count */
__le16 s_max_mnt_count; /* Maximal mount count */
__le16 s_magic; /* Magic signature */
__le16 s_state; /* File system state */
__le16 s_errors; /* Behaviour when detecting errors */
__le16 s_minor_rev_level; /* minor revision level */
/*40*/ __le32 s_lastcheck; /* time of last check */
__le32 s_checkinterval; /* max. time between checks */
__le32 s_creator_os; /* OS */
__le32 s_rev_level; /* Revision level */
/*50*/ __le16 s_def_resuid; /* Default uid for reserved blocks */
__le16 s_def_resgid; /* Default gid for reserved blocks */
/*
* These fields are for EXT4_DYNAMIC_REV superblocks only.
*
* Note: the difference between the compatible feature set and
* the incompatible feature set is that if there is a bit set
* in the incompatible feature set that the kernel doesn't
* know about, it should refuse to mount the filesystem.
*
* e2fsck's requirements are more strict; if it doesn't know
* about a feature in either the compatible or incompatible
* feature set, it must abort and not try to meddle with
* things it doesn't understand...
*/
__le32 s_first_ino; /* First non-reserved inode */
__le16 s_inode_size; /* size of inode structure */
__le16 s_block_group_nr; /* block group # of this superblock */
__le32 s_feature_compat; /* compatible feature set */
/*60*/ __le32 s_feature_incompat; /* incompatible feature set */
__le32 s_feature_ro_compat; /* readonly-compatible feature set */
/*68*/ __u8 s_uuid[16]; /* 128-bit uuid for volume */
/*78*/ char s_volume_name[16]; /* volume name */
/*88*/ char s_last_mounted[64]; /* directory where last mounted */
/*C8*/ __le32 s_algorithm_usage_bitmap; /* For compression */
/*
* Performance hints. Directory preallocation should only
* happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
*/
__u8 s_prealloc_blocks; /* Nr of blocks to try to preallocate*/
__u8 s_prealloc_dir_blocks; /* Nr to preallocate for dirs */
__le16 s_reserved_gdt_blocks; /* Per group desc for online growth */
/*
* Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
*/
/*D0*/ __u8 s_journal_uuid[16]; /* uuid of journal superblock */
/*E0*/ __le32 s_journal_inum; /* inode number of journal file */
__le32 s_journal_dev; /* device number of journal file */
__le32 s_last_orphan; /* start of list of inodes to delete */
__le32 s_hash_seed[4]; /* HTREE hash seed */
__u8 s_def_hash_version; /* Default hash version to use */
__u8 s_reserved_char_pad;
__le16 s_desc_size; /* size of group descriptor */
/*100*/ __le32 s_default_mount_opts;
__le32 s_first_meta_bg; /* First metablock block group */
__le32 s_mkfs_time; /* When the filesystem was created */
__le32 s_jnl_blocks[17]; /* Backup of the journal inode */
/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
/*150*/ __le32 s_blocks_count_hi; /* Blocks count */
__le32 s_r_blocks_count_hi; /* Reserved blocks count */
__le32 s_free_blocks_count_hi; /* Free blocks count */
__le16 s_min_extra_isize; /* All inodes have at least # bytes */
__le16 s_want_extra_isize; /* New inodes should reserve # bytes */
__le32 s_flags; /* Miscellaneous flags */
__le16 s_raid_stride; /* RAID stride */
__le16 s_mmp_interval; /* # seconds to wait in MMP checking */
__le64 s_mmp_block; /* Block for multi-mount protection */
__le32 s_raid_stripe_width; /* blocks on all data disks (N*stride)*/
__u8 s_log_groups_per_flex; /* FLEX_BG group size */
__u8 s_reserved_char_pad2;
__le16 s_reserved_pad;
__le64 s_kbytes_written; /* nr of lifetime kilobytes written */
__u32 s_reserved[160]; /* Padding to the end of the block */
};
#define EXT4_SUPER_MAGIC 0xEF53
#define EXT4_MIN_BLOCK_SIZE 1024
/*
static int _ext4_get_sb(struct block_device* bdev, struct ext4_super_block **p_sb )
{
int res;
struct page* pg = alloc_page(GFP_KERNEL);
void* addr;
if (pg == NULL){
log_err("Failed to allocate page");
return -ENOMEM;
}
addr = page_address(pg);
do{
struct ext4_super_block* sb = NULL;
res = blk_direct_submit_page(bdev, READ_SYNC, 0, pg);//read first page
if (res != SUCCESS){
log_err("Failed to read the first page from the device.");
break;
}
struct ext4_super_block* sb = dbg_kmalloc(sizeof(struct ext4_super_block), GFP_KERNEL);
if (sb == NULL){
res = -ENOMEM;
break;
}
memcpy(sb, addr+2*SECTOR512, sizeof(struct ext4_super_block));
if (le16_to_cpu(sb->s_magic) != EXT4_SUPER_MAGIC){
log_tr("Ext fs not found.");
dbg_kfree(sb);
res = ENOENT;
break;
}
*p_sb = sb;
res = SUCCESS;
} while (false);
free_page(addr);
return res;
}
*/
static int _ext4_get_sb(struct block_device* bdev, struct ext4_super_block **p_sb)
{
int res;
struct buffer_head *bh = NULL;
struct ext4_super_block *es = NULL;
unsigned long long sb_block;
unsigned long offset;
unsigned blocksize = blk_dev_get_block_size(bdev);
sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
offset = EXT4_MIN_BLOCK_SIZE % blocksize;
bh = __bread(bdev, sb_block, blocksize);
if (bh == NULL) {
log_err("Failed to read superblock");
return -ENOMEM;
}
es = (struct ext4_super_block *)(bh->b_data + offset);
do{
struct ext4_super_block* sb = dbg_kmalloc(sizeof(struct ext4_super_block), GFP_KERNEL);
if (sb == NULL){
res = -ENOMEM;
break;
}
if (le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC){
log_tr("Ext fs not found");
dbg_kfree(sb);
res = ENOENT;
break;
}
memcpy(sb, es, sizeof(struct ext4_super_block));
*p_sb = sb;
res = SUCCESS;
} while (false);
brelse(bh);
return res;
}
int ext4_check_offline_changes(struct block_device* bdev, uint32_t previous_crc)
{
struct ext4_super_block* sb = NULL;
int res = _ext4_get_sb(bdev, &sb);
if (res == ENOENT)
return res;
if (res != SUCCESS){
log_err("Failed to read superblock");
return res;
}
//EXT file system found!
log_tr_uuid("128-bit uuid for volume: ", (veeam_uuid_t*)&sb->s_uuid);
log_tr_s("volume name: ", sb->s_volume_name);
log_tr_d("File system state: ", le16_to_cpu(sb->s_state));
log_tr_s_sec("Mount time: ", le32_to_cpu(sb->s_mtime));
log_tr_s_sec("Write time: ", le32_to_cpu(sb->s_wtime));
log_tr_s_sec("Time of last check: ", le32_to_cpu(sb->s_lastcheck));
{
uint32_t crc = crc32(~0, (void*)(sb), sizeof(struct ext4_super_block));
if (crc == previous_crc){
log_tr("Superblock crc match.");
res = SUCCESS;
}else{
log_tr("Superblock crc mismatch.");
log_tr_lx("Previous crc: ", previous_crc);
log_tr_lx("Current crc: ", crc);
res = ENOENT;
}
}
dbg_kfree(sb);
return res;
}
int ext4_check_unmount_status(struct block_device* bdev, uint32_t* p_sb_crc)
{
struct ext4_super_block* sb = NULL;
int res = _ext4_get_sb(bdev, &sb);
if (res == ENOENT)
return res;
if (res != SUCCESS){
log_err("Failed to read superblock");
return res;
}
//EXT file system found!
log_tr_uuid("128-bit uuid for volume: ", (veeam_uuid_t*)&sb->s_uuid );
log_tr_s("volume name: ", sb->s_volume_name);
log_tr_d("File system state: ", le16_to_cpu(sb->s_state));
log_tr_s_sec("Mount time: ", le32_to_cpu(sb->s_mtime));
log_tr_s_sec("Write time: ", le32_to_cpu(sb->s_wtime));
log_tr_s_sec("Time of last check: ", le32_to_cpu(sb->s_lastcheck));
{
uint32_t crc = crc32(~0, (void*)(sb), sizeof(struct ext4_super_block));
*p_sb_crc = crc;
res = SUCCESS;
}
dbg_kfree(sb);
return res;
}
#endif //PERSISTENT_CBT
Zerion Mini Shell 1.0