iov_iter_truncate

函数名称：Cap the iov_iter by given limit; note that the second argument is* *not* the new size - it's upper limit for such. Passing it a value* greater than the amount of data in iov_iter is fine - it'll just do* nothing in that case.

函数原型：static inline void iov_iter_truncate(struct iov_iter *i, u64 count)

返回类型：void

参数：

类型	参数	名称
struct iov_iter *	i
u64	count

**调用者**
名称	描述
generic_file_buffered_read	generic_file_buffered_read - generic file read routine@iocb: the iocb to read@iter: data destination@written: already copied This is a generic file read routine, and uses the* mapping->a_ops->readpage() function for the actual low-level stuff.
generic_write_checks	Performs necessary checks before doing a write* Can adjust writing position or amount of bytes to write.* Returns appropriate error code that caller should return or* zero in case that write should be allowed.
sg_io
blkdev_write_iter	Write data to the block device. Only intended for the block device itself* and the raw driver which basically is a fake block device.* Does not take i_mutex for the write and thus is not for general purpose* use.
blkdev_read_iter
iomap_dio_bio_actor

函数逻辑报告