Open IridiumXOR opened 1 year ago
I have investigated a little bit and seems that starting from kernel 4.14 (when vfs_write
was replaced by kernel_write
) DIO is not usable anymore, because kernel_write
always returns -EFAULT if used with O_DIRECT (it is hardcoded in the code)
EDIT: I have discovered that this behavior is specific of EXT4 if you use a VFAT partition DIO works
How is it possible to enable direct I/O? Obviously, I enable the flag
dio=1
when I load the module however, if I check using a debug build the module always returnsDirect IO Disabled
. I have used a USB3 drive on a real machine but I have also tested the option on a QEMU virtual machine with SCSI, SATA and USB virtual disks with ext4 and xfs but no results (also mounting partitions withsync
option). Can you explain how to use this feature?