ext4: let ext4_truncate handle inline data correctly

Signed-off-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/ext4/inline.c

@@ -1753,3 +1753,93 @@ out:
 	brelse(iloc.bh);
 	return error;
 }
+
+void ext4_inline_data_truncate(struct inode *inode, int *has_inline)
+{
+	handle_t *handle;
+	int inline_size, value_len, needed_blocks;
+	size_t i_size;
+	void *value = NULL;
+	struct ext4_xattr_ibody_find is = {
+		.s = { .not_found = -ENODATA, },
+	};
+	struct ext4_xattr_info i = {
+		.name_index = EXT4_XATTR_INDEX_SYSTEM,
+		.name = EXT4_XATTR_SYSTEM_DATA,
+	};
+
+
+	needed_blocks = ext4_writepage_trans_blocks(inode);
+	handle = ext4_journal_start(inode, needed_blocks);
+	if (IS_ERR(handle))
+		return;
+
+	down_write(&EXT4_I(inode)->xattr_sem);
+	if (!ext4_has_inline_data(inode)) {
+		*has_inline = 0;
+		ext4_journal_stop(handle);
+		return;
+	}
+
+	if (ext4_orphan_add(handle, inode))
+		goto out;
+
+	if (ext4_get_inode_loc(inode, &is.iloc))
+		goto out;
+
+	down_write(&EXT4_I(inode)->i_data_sem);
+	i_size = inode->i_size;
+	inline_size = ext4_get_inline_size(inode);
+	EXT4_I(inode)->i_disksize = i_size;
+
+	if (i_size < inline_size) {
+		/* Clear the content in the xattr space. */
+		if (inline_size > EXT4_MIN_INLINE_DATA_SIZE) {
+			if (ext4_xattr_ibody_find(inode, &i, &is))
+				goto out_error;
+
+			BUG_ON(is.s.not_found);
+
+			value_len = le32_to_cpu(is.s.here->e_value_size);
+			value = kmalloc(value_len, GFP_NOFS);
+			if (!value)
+				goto out_error;
+
+			if (ext4_xattr_ibody_get(inode, i.name_index, i.name,
+						value, value_len))
+				goto out_error;
+
+			i.value = value;
+			i.value_len = i_size > EXT4_MIN_INLINE_DATA_SIZE ?
+					i_size - EXT4_MIN_INLINE_DATA_SIZE : 0;
+			if (ext4_xattr_ibody_inline_set(handle, inode, &i, &is))
+				goto out_error;
+		}
+
+		/* Clear the content within i_blocks. */
+		if (i_size < EXT4_MIN_INLINE_DATA_SIZE)
+			memset(ext4_raw_inode(&is.iloc)->i_block + i_size, 0,
+					EXT4_MIN_INLINE_DATA_SIZE - i_size);
+
+		EXT4_I(inode)->i_inline_size = i_size <
+					EXT4_MIN_INLINE_DATA_SIZE ?
+					EXT4_MIN_INLINE_DATA_SIZE : i_size;
+	}
+
+out_error:
+	up_write(&EXT4_I(inode)->i_data_sem);
+out:
+	brelse(is.iloc.bh);
+	up_write(&EXT4_I(inode)->xattr_sem);
+	kfree(value);
+	if (inode->i_nlink)
+		ext4_orphan_del(handle, inode);
+
+	inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
+	ext4_mark_inode_dirty(handle, inode);
+	if (IS_SYNC(inode))
+		ext4_handle_sync(handle);
+
+	ext4_journal_stop(handle);
+	return;
+}

fs/ext4/inode.c

@@ -3594,6 +3594,14 @@ void ext4_truncate(struct inode *inode)
 	if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
 		ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
 
+	if (ext4_has_inline_data(inode)) {
+		int has_inline = 1;
+
+		ext4_inline_data_truncate(inode, &has_inline);
+		if (has_inline)
+			return;
+	}
+
 	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
 		ext4_ext_truncate(inode);
 	else

fs/ext4/xattr.h

@@ -190,6 +190,8 @@ extern int ext4_inline_data_fiemap(struct inode *inode,
 extern int ext4_try_to_evict_inline_data(handle_t *handle,
 					 struct inode *inode,
 					 int needed);
+extern void ext4_inline_data_truncate(struct inode *inode, int *has_inline);
+
 # else  /* CONFIG_EXT4_FS_XATTR */
 
 static inline int
@@ -411,6 +413,13 @@ static inline int ext4_inline_data_fiemap(struct inode *inode,
 {
 	return 0;
 }
+
+static inline void ext4_inline_data_truncate(struct inode *inode,
+					     int *has_inline)
+{
+	return;
+}
+
 # endif  /* CONFIG_EXT4_FS_XATTR */
 
 #ifdef CONFIG_EXT4_FS_SECURITY