For exFAT filesystems with 4MB read_ahead_size, removing the storage device
when the read operation is in progress, which cause the last read syscall
spent 150s [1]. The main reason is that exFAT generates excessive log
messages [2].
After applying this patch, approximately 300,000 lines of log messages
were suppressed, and the delay of the last read() syscall was reduced
to about 4 seconds.