ext4: let fallocate handle inline data correctly

If we are punching hole in a file, we will return ENOTSUPP.
As for the fallocation of some extents, we will convert the
inline data to a normal extent based file first.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/ext4/extents.c

@@ -4399,6 +4399,10 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 	if (mode & FALLOC_FL_PUNCH_HOLE)
 		return ext4_punch_hole(file, offset, len);
 
+	ret = ext4_convert_inline_data(inode);
+	if (ret)
+		return ret;
+
 	trace_ext4_fallocate_enter(inode, offset, len, mode);
 	map.m_lblk = offset >> blkbits;
 	/*

fs/ext4/inline.c

@@ -1843,3 +1843,42 @@ void ext4_inline_data_truncate(struct inode *inode, int *has_inline)
 	ext4_journal_stop(handle);
 	return;
 }
+
+int ext4_convert_inline_data(struct inode *inode)
+{
+	int error, needed_blocks;
+	handle_t *handle;
+	struct ext4_iloc iloc;
+
+	if (!ext4_has_inline_data(inode)) {
+		ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
+		return 0;
+	}
+
+	needed_blocks = ext4_writepage_trans_blocks(inode);
+
+	iloc.bh = NULL;
+	error = ext4_get_inode_loc(inode, &iloc);
+	if (error)
+		return error;
+
+	handle = ext4_journal_start(inode, needed_blocks);
+	if (IS_ERR(handle)) {
+		error = PTR_ERR(handle);
+		goto out_free;
+	}
+
+	down_write(&EXT4_I(inode)->xattr_sem);
+	if (!ext4_has_inline_data(inode)) {
+		up_write(&EXT4_I(inode)->xattr_sem);
+		goto out;
+	}
+
+	error = ext4_convert_inline_data_nolock(handle, inode, &iloc);
+	up_write(&EXT4_I(inode)->xattr_sem);
+out:
+	ext4_journal_stop(handle);
+out_free:
+	brelse(iloc.bh);
+	return error;
+}

fs/ext4/xattr.h

@@ -192,6 +192,7 @@ extern int ext4_try_to_evict_inline_data(handle_t *handle,
 					 int needed);
 extern void ext4_inline_data_truncate(struct inode *inode, int *has_inline);
 
+extern int ext4_convert_inline_data(struct inode *inode);
 # else  /* CONFIG_EXT4_FS_XATTR */
 
 static inline int
@@ -420,6 +421,10 @@ static inline void ext4_inline_data_truncate(struct inode *inode,
 	return;
 }
 
+static inline int ext4_convert_inline_data(struct inode *inode)
+{
+	return 0;
+}
 # endif  /* CONFIG_EXT4_FS_XATTR */
 
 #ifdef CONFIG_EXT4_FS_SECURITY