ext4fs write support

Signed-off-by: Uma Shankar <uma.shankar@samsung.com>
Signed-off-by: Manjunatha C Achar <a.manjunatha@samsung.com>
Signed-off-by: Iqbal Shareef <iqbal.ams@samsung.com>
Signed-off-by: Hakgoo Lee <goodguy.lee@samsung.com>

1 files changed, 667 insertions, 0 deletions

diff --git a/fs/ext4/ext4_journal.c b/fs/ext4/ext4_journal.c
new file mode 100644
index 0000000..8a252d6
--- /dev/null
+++ b/fs/ext4/ext4_journal.c
@@ -0,0 +1,667 @@
+/*
+ * (C) Copyright 2011 - 2012 Samsung Electronics
+ * EXT4 filesystem implementation in Uboot by
+ * Uma Shankar <uma.shankar@samsung.com>
+ * Manjunatha C Achar <a.manjunatha@samsung.com>
+ *
+ * Journal data structures and headers for Journaling feature of ext4
+ * have been referred from JBD2 (Journaling Block device 2)
+ * implementation in Linux Kernel.
+ * Written by Stephen C. Tweedie <sct@redhat.com>
+ *
+ * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved
+ * This file is part of the Linux kernel and is made available under
+ * the terms of the GNU General Public License, version 2, or at your
+ * option, any later version, incorporated herein by reference.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <common.h>
+#include <ext4fs.h>
+#include <malloc.h>
+#include <ext_common.h>
+#include "ext4_common.h"
+
+static struct revoke_blk_list *revk_blk_list;
+static struct revoke_blk_list *prev_node;
+static int first_node = TRUE;
+
+int gindex;
+int gd_index;
+int jrnl_blk_idx;
+struct journal_log *journal_ptr[MAX_JOURNAL_ENTRIES];
+struct dirty_blocks *dirty_block_ptr[MAX_JOURNAL_ENTRIES];
+
+int ext4fs_init_journal(void)
+{
+	int i;
+	char *temp = NULL;
+	struct ext_filesystem *fs = get_fs();
+
+	/* init globals */
+	revk_blk_list = NULL;
+	prev_node = NULL;
+	gindex = 0;
+	gd_index = 0;
+	jrnl_blk_idx = 1;
+
+	for (i = 0; i < MAX_JOURNAL_ENTRIES; i++) {
+		journal_ptr[i] = zalloc(sizeof(struct journal_log));
+		if (!journal_ptr[i])
+			goto fail;
+		dirty_block_ptr[i] = zalloc(sizeof(struct dirty_blocks));
+		if (!dirty_block_ptr[i])
+			goto fail;
+		journal_ptr[i]->buf = NULL;
+		journal_ptr[i]->blknr = -1;
+
+		dirty_block_ptr[i]->buf = NULL;
+		dirty_block_ptr[i]->blknr = -1;
+	}
+
+	if (fs->blksz == 4096) {
+		temp = zalloc(fs->blksz);
+		if (!temp)
+			goto fail;
+		journal_ptr[gindex]->buf = zalloc(fs->blksz);
+		if (!journal_ptr[gindex]->buf)
+			goto fail;
+		ext4fs_devread(0, 0, fs->blksz, temp);
+		memcpy(temp + SUPERBLOCK_SIZE, fs->sb, SUPERBLOCK_SIZE);
+		memcpy(journal_ptr[gindex]->buf, temp, fs->blksz);
+		journal_ptr[gindex++]->blknr = 0;
+		free(temp);
+	} else {
+		journal_ptr[gindex]->buf = zalloc(fs->blksz);
+		if (!journal_ptr[gindex]->buf)
+			goto fail;
+		memcpy(journal_ptr[gindex]->buf, fs->sb, SUPERBLOCK_SIZE);
+		journal_ptr[gindex++]->blknr = 1;
+	}
+
+	/* Check the file system state using journal super block */
+	if (ext4fs_check_journal_state(SCAN))
+		goto fail;
+	/* Check the file system state using journal super block */
+	if (ext4fs_check_journal_state(RECOVER))
+		goto fail;
+
+	return 0;
+fail:
+	return -1;
+}
+
+void ext4fs_dump_metadata(void)
+{
+	struct ext_filesystem *fs = get_fs();
+	int i;
+	for (i = 0; i < MAX_JOURNAL_ENTRIES; i++) {
+		if (dirty_block_ptr[i]->blknr == -1)
+			break;
+		put_ext4((uint64_t) ((uint64_t)dirty_block_ptr[i]->blknr *
+				(uint64_t)fs->blksz), dirty_block_ptr[i]->buf,
+								fs->blksz);
+	}
+}
+
+void ext4fs_free_journal(void)
+{
+	int i;
+	for (i = 0; i < MAX_JOURNAL_ENTRIES; i++) {
+		if (dirty_block_ptr[i]->blknr == -1)
+			break;
+		if (dirty_block_ptr[i]->buf)
+			free(dirty_block_ptr[i]->buf);
+	}
+
+	for (i = 0; i < MAX_JOURNAL_ENTRIES; i++) {
+		if (journal_ptr[i]->blknr == -1)
+			break;
+		if (journal_ptr[i]->buf)
+			free(journal_ptr[i]->buf);
+	}
+
+	for (i = 0; i < MAX_JOURNAL_ENTRIES; i++) {
+		if (journal_ptr[i])
+			free(journal_ptr[i]);
+		if (dirty_block_ptr[i])
+			free(dirty_block_ptr[i]);
+	}
+	gindex = 0;
+	gd_index = 0;
+	jrnl_blk_idx = 1;
+}
+
+int ext4fs_log_gdt(char *gd_table)
+{
+	struct ext_filesystem *fs = get_fs();
+	short i;
+	long int var = fs->gdtable_blkno;
+	for (i = 0; i < fs->no_blk_pergdt; i++) {
+		journal_ptr[gindex]->buf = zalloc(fs->blksz);
+		if (!journal_ptr[gindex]->buf)
+			return -ENOMEM;
+		memcpy(journal_ptr[gindex]->buf, gd_table, fs->blksz);
+		gd_table += fs->blksz;
+		journal_ptr[gindex++]->blknr = var++;
+	}
+
+	return 0;
+}
+
+/*
+ * This function stores the backup copy of meta data in RAM
+ * journal_buffer -- Buffer containing meta data
+ * blknr -- Block number on disk of the meta data buffer
+ */
+int ext4fs_log_journal(char *journal_buffer, long int blknr)
+{
+	struct ext_filesystem *fs = get_fs();
+	short i;
+
+	if (!journal_buffer) {
+		printf("Invalid input arguments %s\n", __func__);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < MAX_JOURNAL_ENTRIES; i++) {
+		if (journal_ptr[i]->blknr == -1)
+			break;
+		if (journal_ptr[i]->blknr == blknr)
+			return 0;
+	}
+
+	journal_ptr[gindex]->buf = zalloc(fs->blksz);
+	if (!journal_ptr[gindex]->buf)
+		return -ENOMEM;
+
+	memcpy(journal_ptr[gindex]->buf, journal_buffer, fs->blksz);
+	journal_ptr[gindex++]->blknr = blknr;
+
+	return 0;
+}
+
+/*
+ * This function stores the modified meta data in RAM
+ * metadata_buffer -- Buffer containing meta data
+ * blknr -- Block number on disk of the meta data buffer
+ */
+int ext4fs_put_metadata(char *metadata_buffer, long int blknr)
+{
+	struct ext_filesystem *fs = get_fs();
+	if (!metadata_buffer) {
+		printf("Invalid input arguments %s\n", __func__);
+		return -EINVAL;
+	}
+	dirty_block_ptr[gd_index]->buf = zalloc(fs->blksz);
+	if (!dirty_block_ptr[gd_index]->buf)
+		return -ENOMEM;
+	memcpy(dirty_block_ptr[gd_index]->buf, metadata_buffer, fs->blksz);
+	dirty_block_ptr[gd_index++]->blknr = blknr;
+
+	return 0;
+}
+
+void print_revoke_blks(char *revk_blk)
+{
+	int offset;
+	int max;
+	long int blocknr;
+	struct journal_revoke_header_t *header;
+
+	if (revk_blk == NULL)
+		return;
+
+	header = (struct journal_revoke_header_t *) revk_blk;
+	offset = sizeof(struct journal_revoke_header_t);
+	max = be32_to_cpu(header->r_count);
+	printf("total bytes %d\n", max);
+
+	while (offset < max) {
+		blocknr = be32_to_cpu(*((long int *)(revk_blk + offset)));
+		printf("revoke blknr is %ld\n", blocknr);
+		offset += 4;
+	}
+}
+
+static struct revoke_blk_list *_get_node(void)
+{
+	struct revoke_blk_list *tmp_node;
+	tmp_node = zalloc(sizeof(struct revoke_blk_list));
+	if (tmp_node == NULL)
+		return NULL;
+	tmp_node->content = NULL;
+	tmp_node->next = NULL;
+
+	return tmp_node;
+}
+
+void ext4fs_push_revoke_blk(char *buffer)
+{
+	struct revoke_blk_list *node = NULL;
+	struct ext_filesystem *fs = get_fs();
+	if (buffer == NULL) {
+		printf("buffer ptr is NULL\n");
+		return;
+	}
+	node = _get_node();
+	if (!node) {
+		printf("_get_node: malloc failed\n");
+		return;
+	}
+
+	node->content = zalloc(fs->blksz);
+	if (node->content == NULL)
+		return;
+	memcpy(node->content, buffer, fs->blksz);
+
+	if (first_node == TRUE) {
+		revk_blk_list = node;
+		prev_node = node;
+		 first_node = FALSE;
+	} else {
+		prev_node->next = node;
+		prev_node = node;
+	}
+}
+
+void ext4fs_free_revoke_blks(void)
+{
+	struct revoke_blk_list *tmp_node = revk_blk_list;
+	struct revoke_blk_list *next_node = NULL;
+
+	while (tmp_node != NULL) {
+		if (tmp_node->content)
+			free(tmp_node->content);
+		tmp_node = tmp_node->next;
+	}
+
+	tmp_node = revk_blk_list;
+	while (tmp_node != NULL) {
+		next_node = tmp_node->next;
+		free(tmp_node);
+		tmp_node = next_node;
+	}
+
+	revk_blk_list = NULL;
+	prev_node = NULL;
+	first_node = TRUE;
+}
+
+int check_blknr_for_revoke(long int blknr, int sequence_no)
+{
+	struct journal_revoke_header_t *header;
+	int offset;
+	int max;
+	long int blocknr;
+	char *revk_blk;
+	struct revoke_blk_list *tmp_revk_node = revk_blk_list;
+	while (tmp_revk_node != NULL) {
+		revk_blk = tmp_revk_node->content;
+
+		header = (struct journal_revoke_header_t *) revk_blk;
+		if (sequence_no < be32_to_cpu(header->r_header.h_sequence)) {
+			offset = sizeof(struct journal_revoke_header_t);
+			max = be32_to_cpu(header->r_count);
+
+			while (offset < max) {
+				blocknr = be32_to_cpu(*((long int *)
+						  (revk_blk + offset)));
+				if (blocknr == blknr)
+					goto found;
+				offset += 4;
+			}
+		}
+		tmp_revk_node = tmp_revk_node->next;
+	}
+
+	return -1;
+
+found:
+	return 0;
+}
+
+/*
+ * This function parses the journal blocks and replays the
+ * suceessful transactions. A transaction is successfull
+ * if commit block is found for a descriptor block
+ * The tags in descriptor block contain the disk block
+ * numbers of the metadata  to be replayed
+ */
+void recover_transaction(int prev_desc_logical_no)
+{
+	struct ext2_inode inode_journal;
+	struct ext_filesystem *fs = get_fs();
+	struct journal_header_t *jdb;
+	long int blknr;
+	char *p_jdb;
+	int ofs, flags;
+	int i;
+	struct ext3_journal_block_tag *tag;
+	char *temp_buff = zalloc(fs->blksz);
+	char *metadata_buff = zalloc(fs->blksz);
+	if (!temp_buff || !metadata_buff)
+		goto fail;
+	i = prev_desc_logical_no;
+	ext4fs_read_inode(ext4fs_root, EXT2_JOURNAL_INO,
+			  (struct ext2_inode *)&inode_journal);
+	blknr = read_allocated_block((struct ext2_inode *)
+				     &inode_journal, i);
+	ext4fs_devread(blknr * fs->sect_perblk, 0, fs->blksz, temp_buff);
+	p_jdb = (char *)temp_buff;
+	jdb = (struct journal_header_t *) temp_buff;
+	ofs = sizeof(struct journal_header_t);
+
+	do {
+		tag = (struct ext3_journal_block_tag *)&p_jdb[ofs];
+		ofs += sizeof(struct ext3_journal_block_tag);
+
+		if (ofs > fs->blksz)
+			break;
+
+		flags = be32_to_cpu(tag->flags);
+		if (!(flags & EXT3_JOURNAL_FLAG_SAME_UUID))
+			ofs += 16;
+
+		i++;
+		debug("\t\ttag %u\n", be32_to_cpu(tag->block));
+		if (revk_blk_list != NULL) {
+			if (check_blknr_for_revoke(be32_to_cpu(tag->block),
+				be32_to_cpu(jdb->h_sequence)) == 0)
+				continue;
+		}
+		blknr = read_allocated_block(&inode_journal, i);
+		ext4fs_devread(blknr * fs->sect_perblk, 0,
+			       fs->blksz, metadata_buff);
+		put_ext4((uint64_t)(be32_to_cpu(tag->block) * fs->blksz),
+			 metadata_buff, (uint32_t) fs->blksz);
+	} while (!(flags & EXT3_JOURNAL_FLAG_LAST_TAG));
+fail:
+	free(temp_buff);
+	free(metadata_buff);
+}
+
+void print_jrnl_status(int recovery_flag)
+{
+	if (recovery_flag == RECOVER)
+		printf("Journal Recovery Completed\n");
+	else
+		printf("Journal Scan Completed\n");
+}
+
+int ext4fs_check_journal_state(int recovery_flag)
+{
+	int i;
+	int DB_FOUND = NO;
+	long int blknr;
+	int transaction_state = TRANSACTION_COMPLETE;
+	int prev_desc_logical_no = 0;
+	int curr_desc_logical_no = 0;
+	int ofs, flags, block;
+	struct ext2_inode inode_journal;
+	struct journal_superblock_t *jsb = NULL;
+	struct journal_header_t *jdb = NULL;
+	char *p_jdb = NULL;
+	struct ext3_journal_block_tag *tag = NULL;
+	char *temp_buff = NULL;
+	char *temp_buff1 = NULL;
+	struct ext_filesystem *fs = get_fs();
+
+	temp_buff = zalloc(fs->blksz);
+	if (!temp_buff)
+		return -ENOMEM;
+	temp_buff1 = zalloc(fs->blksz);
+	if (!temp_buff1) {
+		free(temp_buff);
+		return -ENOMEM;
+	}
+
+	ext4fs_read_inode(ext4fs_root, EXT2_JOURNAL_INO, &inode_journal);
+	blknr = read_allocated_block(&inode_journal, EXT2_JOURNAL_SUPERBLOCK);
+	ext4fs_devread(blknr * fs->sect_perblk, 0, fs->blksz, temp_buff);
+	jsb = (struct journal_superblock_t *) temp_buff;
+
+	if (fs->sb->feature_incompat & EXT3_FEATURE_INCOMPAT_RECOVER) {
+		if (recovery_flag == RECOVER)
+			printf("Recovery required\n");
+	} else {
+		if (recovery_flag == RECOVER)
+			printf("File System is consistent\n");
+		goto end;
+	}
+
+	if (be32_to_cpu(jsb->s_start) == 0)
+		goto end;
+
+	if (!(jsb->s_feature_compat &
+				cpu_to_be32(JBD2_FEATURE_COMPAT_CHECKSUM)))
+		jsb->s_feature_compat |=
+				cpu_to_be32(JBD2_FEATURE_COMPAT_CHECKSUM);
+
+	i = be32_to_cpu(jsb->s_first);
+	while (1) {
+		block = be32_to_cpu(jsb->s_first);
+		blknr = read_allocated_block(&inode_journal, i);
+		memset(temp_buff1, '\0', fs->blksz);
+		ext4fs_devread(blknr * fs->sect_perblk,
+			       0, fs->blksz, temp_buff1);
+		jdb = (struct journal_header_t *) temp_buff1;
+
+		if (be32_to_cpu(jdb->h_blocktype) ==
+		    EXT3_JOURNAL_DESCRIPTOR_BLOCK) {
+			if (be32_to_cpu(jdb->h_sequence) !=
+			    be32_to_cpu(jsb->s_sequence)) {
+				print_jrnl_status(recovery_flag);
+				break;
+			}
+
+			curr_desc_logical_no = i;
+			if (transaction_state == TRANSACTION_COMPLETE)
+				transaction_state = TRANSACTION_RUNNING;
+			else
+				return -1;
+			p_jdb = (char *)temp_buff1;
+			ofs = sizeof(struct journal_header_t);
+			do {
+				tag = (struct ext3_journal_block_tag *)
+				    &p_jdb[ofs];
+				ofs += sizeof(struct ext3_journal_block_tag);
+				if (ofs > fs->blksz)
+					break;
+				flags = be32_to_cpu(tag->flags);
+				if (!(flags & EXT3_JOURNAL_FLAG_SAME_UUID))
+					ofs += 16;
+				i++;
+				debug("\t\ttag %u\n", be32_to_cpu(tag->block));
+			} while (!(flags & EXT3_JOURNAL_FLAG_LAST_TAG));
+			i++;
+			DB_FOUND = YES;
+		} else if (be32_to_cpu(jdb->h_blocktype) ==
+				EXT3_JOURNAL_COMMIT_BLOCK) {
+			if (be32_to_cpu(jdb->h_sequence) !=
+			     be32_to_cpu(jsb->s_sequence)) {
+				print_jrnl_status(recovery_flag);
+				break;
+			}
+
+			if (transaction_state == TRANSACTION_RUNNING ||
+					(DB_FOUND == NO)) {
+				transaction_state = TRANSACTION_COMPLETE;
+				i++;
+				jsb->s_sequence =
+					cpu_to_be32(be32_to_cpu(
+						jsb->s_sequence) + 1);
+			}
+			prev_desc_logical_no = curr_desc_logical_no;
+			if ((recovery_flag == RECOVER) && (DB_FOUND == YES))
+				recover_transaction(prev_desc_logical_no);
+
+			DB_FOUND = NO;
+		} else if (be32_to_cpu(jdb->h_blocktype) ==
+				EXT3_JOURNAL_REVOKE_BLOCK) {
+			if (be32_to_cpu(jdb->h_sequence) !=
+			    be32_to_cpu(jsb->s_sequence)) {
+				print_jrnl_status(recovery_flag);
+				break;
+			}
+			if (recovery_flag == SCAN)
+				ext4fs_push_revoke_blk((char *)jdb);
+			i++;
+		} else {
+			debug("Else Case\n");
+			if (be32_to_cpu(jdb->h_sequence) !=
+			    be32_to_cpu(jsb->s_sequence)) {
+				print_jrnl_status(recovery_flag);
+				break;
+			}
+		}
+	}
+
+end:
+	if (recovery_flag == RECOVER) {
+		jsb->s_start = cpu_to_be32(1);
+		jsb->s_sequence = cpu_to_be32(be32_to_cpu(jsb->s_sequence) + 1);
+		/* get the superblock */
+		ext4fs_devread(SUPERBLOCK_SECTOR, 0, SUPERBLOCK_SIZE,
+			       (char *)fs->sb);
+		fs->sb->feature_incompat |= EXT3_FEATURE_INCOMPAT_RECOVER;
+
+		/* Update the super block */
+		put_ext4((uint64_t) (SUPERBLOCK_SIZE),
+			 (struct ext2_sblock *)fs->sb,
+			 (uint32_t) SUPERBLOCK_SIZE);
+		ext4fs_devread(SUPERBLOCK_SECTOR, 0, SUPERBLOCK_SIZE,
+			       (char *)fs->sb);
+
+		blknr = read_allocated_block(&inode_journal,
+					 EXT2_JOURNAL_SUPERBLOCK);
+		put_ext4((uint64_t) (blknr * fs->blksz),
+			 (struct journal_superblock_t *)temp_buff,
+			 (uint32_t) fs->blksz);
+		ext4fs_free_revoke_blks();
+	}
+	free(temp_buff);
+	free(temp_buff1);
+
+	return 0;
+}
+
+static void update_descriptor_block(long int blknr)
+{
+	int i;
+	long int jsb_blknr;
+	struct journal_header_t jdb;
+	struct ext3_journal_block_tag tag;
+	struct ext2_inode inode_journal;
+	struct journal_superblock_t *jsb = NULL;
+	char *buf = NULL;
+	char *temp = NULL;
+	struct ext_filesystem *fs = get_fs();
+	char *temp_buff = zalloc(fs->blksz);
+	if (!temp_buff)
+		return;
+
+	ext4fs_read_inode(ext4fs_root, EXT2_JOURNAL_INO, &inode_journal);
+	jsb_blknr = read_allocated_block(&inode_journal,
+					 EXT2_JOURNAL_SUPERBLOCK);
+	ext4fs_devread(jsb_blknr * fs->sect_perblk, 0, fs->blksz, temp_buff);
+	jsb = (struct journal_superblock_t *) temp_buff;
+
+	jdb.h_blocktype = cpu_to_be32(EXT3_JOURNAL_DESCRIPTOR_BLOCK);
+	jdb.h_magic = cpu_to_be32(EXT3_JOURNAL_MAGIC_NUMBER);
+	jdb.h_sequence = jsb->s_sequence;
+	buf = zalloc(fs->blksz);
+	if (!buf) {
+		free(temp_buff);
+		return;
+	}
+	temp = buf;
+	memcpy(buf, &jdb, sizeof(struct journal_header_t));
+	temp += sizeof(struct journal_header_t);
+
+	for (i = 0; i < MAX_JOURNAL_ENTRIES; i++) {
+		if (journal_ptr[i]->blknr == -1)
+			break;
+
+		tag.block = cpu_to_be32(journal_ptr[i]->blknr);
+		tag.flags = cpu_to_be32(EXT3_JOURNAL_FLAG_SAME_UUID);
+		memcpy(temp, &tag, sizeof(struct ext3_journal_block_tag));
+		temp = temp + sizeof(struct ext3_journal_block_tag);
+	}
+
+	tag.block = cpu_to_be32(journal_ptr[--i]->blknr);
+	tag.flags = cpu_to_be32(EXT3_JOURNAL_FLAG_LAST_TAG);
+	memcpy(temp - sizeof(struct ext3_journal_block_tag), &tag,
+	       sizeof(struct ext3_journal_block_tag));
+	put_ext4((uint64_t) (blknr * fs->blksz), buf, (uint32_t) fs->blksz);
+
+	free(temp_buff);
+	free(buf);
+}
+
+static void update_commit_block(long int blknr)
+{
+	struct journal_header_t jdb;
+	struct ext_filesystem *fs = get_fs();
+	char *buf = NULL;
+	struct ext2_inode inode_journal;
+	struct journal_superblock_t *jsb;
+	long int jsb_blknr;
+	char *temp_buff = zalloc(fs->blksz);
+	if (!temp_buff)
+		return;
+
+	ext4fs_read_inode(ext4fs_root, EXT2_JOURNAL_INO, &inode_journal);
+	jsb_blknr = read_allocated_block(&inode_journal,
+					 EXT2_JOURNAL_SUPERBLOCK);
+	ext4fs_devread(jsb_blknr * fs->sect_perblk, 0, fs->blksz, temp_buff);
+	jsb = (struct journal_superblock_t *) temp_buff;
+
+	jdb.h_blocktype = cpu_to_be32(EXT3_JOURNAL_COMMIT_BLOCK);
+	jdb.h_magic = cpu_to_be32(EXT3_JOURNAL_MAGIC_NUMBER);
+	jdb.h_sequence = jsb->s_sequence;
+	buf = zalloc(fs->blksz);
+	if (!buf) {
+		free(temp_buff);
+		return;
+	}
+	memcpy(buf, &jdb, sizeof(struct journal_header_t));
+	put_ext4((uint64_t) (blknr * fs->blksz), buf, (uint32_t) fs->blksz);
+
+	free(temp_buff);
+	free(buf);
+}
+
+void ext4fs_update_journal(void)
+{
+	struct ext2_inode inode_journal;
+	struct ext_filesystem *fs = get_fs();
+	long int blknr;
+	int i;
+	ext4fs_read_inode(ext4fs_root, EXT2_JOURNAL_INO, &inode_journal);
+	blknr = read_allocated_block(&inode_journal, jrnl_blk_idx++);
+	update_descriptor_block(blknr);
+	for (i = 0; i < MAX_JOURNAL_ENTRIES; i++) {
+		if (journal_ptr[i]->blknr == -1)
+			break;
+		blknr = read_allocated_block(&inode_journal, jrnl_blk_idx++);
+		put_ext4((uint64_t) ((uint64_t)blknr * (uint64_t)fs->blksz),
+			 journal_ptr[i]->buf, fs->blksz);
+	}
+	blknr = read_allocated_block(&inode_journal, jrnl_blk_idx++);
+	update_commit_block(blknr);
+	printf("update journal finished\n");
+}