Index: linux-stage/fs/ext4/super.c
===================================================================
--- linux-stage.orig/fs/ext4/super.c
+++ linux-stage/fs/ext4/super.c
@@ -662,7 +662,12 @@ static void ext4_put_super(struct super_
 
 	for (i = 0; i < sbi->s_gdb_count; i++)
 		brelse(sbi->s_group_desc[i]);
-	kfree(sbi->s_group_desc);
+
+	if (is_vmalloc_addr(sbi->s_group_desc))
+		vfree(sbi->s_group_desc);
+	else
+		kfree(sbi->s_group_desc);
+
 	if (is_vmalloc_addr(sbi->s_flex_groups))
 		vfree(sbi->s_flex_groups);
 	else
@@ -2402,12 +2407,13 @@ static int ext4_fill_super(struct super_
 	unsigned long offset = 0;
 	unsigned long journal_devnum = 0;
 	unsigned long def_mount_opts;
-	struct inode *root;
+	struct inode *root = NULL;
 	char *cp;
 	const char *descr;
 	int ret = -EINVAL;
 	int blocksize;
 	unsigned int db_count;
+	size_t size;
 	unsigned int i;
 	int needs_recovery, has_huge_files;
 	__u64 blocks_count;
@@ -2718,10 +2724,16 @@ static int ext4_fill_super(struct super_
 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
 		   EXT4_DESC_PER_BLOCK(sb);
-	sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
-				    GFP_KERNEL);
+	size = (size_t) db_count * sizeof(struct buffer_head *);
+	sbi->s_group_desc = kzalloc(size, GFP_KERNEL);
+	if (sbi->s_group_desc == NULL) {
+		sbi->s_group_desc = vmalloc(size);
+		if (sbi->s_group_desc != NULL)
+			memset(sbi->s_group_desc, 0, size);
+	}
 	if (sbi->s_group_desc == NULL) {
-		ext4_msg(sb, KERN_ERR, "not enough memory");
+		ext4_msg(sb, KERN_ERR, "not enough memory for %u groups (%u)\n",
+			sbi->s_groups_count, (unsigned int) size);
 		goto failed_mount;
 	}
 
@@ -2907,17 +2919,16 @@ no_journal:
 	if (IS_ERR(root)) {
 		ext4_msg(sb, KERN_ERR, "get root inode failed");
 		ret = PTR_ERR(root);
+		root = NULL;
 		goto failed_mount4;
 	}
 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
-		iput(root);
 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
 		goto failed_mount4;
 	}
 	sb->s_root = d_alloc_root(root);
 	if (!sb->s_root) {
 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
-		iput(root);
 		ret = -ENOMEM;
 		goto failed_mount4;
 	}
@@ -2968,6 +2979,7 @@ no_journal:
 	if (err) {
 		ext4_msg(sb, KERN_ERR, "failed to initalize mballoc (%d)",
 			 err);
+		ret = err;
 		goto failed_mount4;
 	}
 
@@ -3011,6 +3023,8 @@ cantfind_ext4:
 	goto failed_mount;
 
 failed_mount4:
+	iput(root);
+	sb->s_root = NULL;
 	ext4_msg(sb, KERN_ERR, "mount failed");
 	destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
 failed_mount_wq:
@@ -3033,7 +3047,11 @@ failed_mount3:
 failed_mount2:
 	for (i = 0; i < db_count; i++)
 		brelse(sbi->s_group_desc[i]);
-	kfree(sbi->s_group_desc);
+
+	if (is_vmalloc_addr(sbi->s_group_desc))
+		vfree(sbi->s_group_desc);
+	else
+		kfree(sbi->s_group_desc);
 failed_mount:
 	if (sbi->s_proc) {
 		remove_proc_entry(sb->s_id, ext4_proc_root);
Index: linux-stage/fs/ext4/mballoc.c
===================================================================
--- linux-stage.orig/fs/ext4/mballoc.c
+++ linux-stage/fs/ext4/mballoc.c
@@ -2607,10 +2607,21 @@ static int ext4_mb_init_backend(struct s
 	while (array_size < sizeof(*sbi->s_group_info) *
 	       num_meta_group_infos_max)
 		array_size = array_size << 1;
-	/* An 8TB filesystem with 64-bit pointers requires a 4096 byte
-	 * kmalloc. A 128kb malloc should suffice for a 256TB filesystem.
-	 * So a two level scheme suffices for now. */
-	sbi->s_group_info = kmalloc(array_size, GFP_KERNEL);
+
+	/*
+	 * A 16TB filesystem with 64-bit pointers requires an 8192 byte
+	 * kmalloc(). Filesystems larger than 2^32 blocks (16TB normally)
+	 * have group descriptors at least twice as large (64 bytes or
+	 * more vs. 32 bytes for traditional ext3 filesystems, so a 128TB
+	 * filesystem needs a 128kB allocation, which may need vmalloc().
+	 */
+	sbi->s_group_info = kzalloc(array_size, GFP_KERNEL);
+	if (sbi->s_group_info == NULL) {
+		sbi->s_group_info = vmalloc(array_size);
+		if (sbi->s_group_info != NULL)
+			memset(sbi->s_group_info, 0, array_size);
+	}
+
 	if (sbi->s_group_info == NULL) {
 		printk(KERN_ERR "EXT4-fs: can't allocate buddy meta group\n");
 		return -ENOMEM;
@@ -2620,6 +2631,11 @@ static int ext4_mb_init_backend(struct s
 		printk(KERN_ERR "EXT4-fs: can't get new inode\n");
 		goto err_freesgi;
 	}
+	/*
+	 * To avoid colliding with an valid on-disk inode number,
+	 * EXT4_BAD_INO is used here as the number of the buddy cache inode.
+	 */
+	sbi->s_buddy_cache->i_ino = EXT4_BAD_INO;
 	EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
 	for (i = 0; i < ngroups; i++) {
 		desc = ext4_get_group_desc(sb, i, NULL);
@@ -2642,7 +2658,10 @@ err_freebuddy:
 		kfree(sbi->s_group_info[i]);
 	iput(sbi->s_buddy_cache);
 err_freesgi:
-	kfree(sbi->s_group_info);
+	if (is_vmalloc_addr(sbi->s_group_info))
+		vfree(sbi->s_group_info);
+	else
+		kfree(sbi->s_group_info);
 	return -ENOMEM;
 }
 
@@ -2683,14 +2702,6 @@ int ext4_mb_init(struct super_block *sb,
 		i++;
 	} while (i <= sb->s_blocksize_bits + 1);
 
-	/* init file for buddy data */
-	ret = ext4_mb_init_backend(sb);
-	if (ret != 0) {
-		kfree(sbi->s_mb_offsets);
-		kfree(sbi->s_mb_maxs);
-		return ret;
-	}
-
 	spin_lock_init(&sbi->s_md_lock);
 	spin_lock_init(&sbi->s_bal_lock);
 
@@ -2717,6 +2728,14 @@ int ext4_mb_init(struct super_block *sb,
 		spin_lock_init(&lg->lg_prealloc_lock);
 	}
 
+	/* init file for buddy data */
+	ret = ext4_mb_init_backend(sb);
+	if (ret != 0) {
+		kfree(sbi->s_mb_offsets);
+		kfree(sbi->s_mb_maxs);
+		return ret;
+	}
+
 	ext4_mb_history_init(sb);
 
 	if (sbi->s_journal)
@@ -2766,7 +2785,10 @@ int ext4_mb_release(struct super_block *
 			EXT4_DESC_PER_BLOCK_BITS(sb);
 		for (i = 0; i < num_meta_group_infos; i++)
 			kfree(sbi->s_group_info[i]);
-		kfree(sbi->s_group_info);
+		if (is_vmalloc_addr(sbi->s_group_info))
+			vfree(sbi->s_group_info);
+		else
+			kfree(sbi->s_group_info);
 	}
 	kfree(sbi->s_mb_offsets);
 	kfree(sbi->s_mb_maxs);