I was told that the Linux SCSI sub-system does not convey SCSI commands
between the mid-level and low-level via ioctl calls. ioctl()s defined in
low-level are for very special reasons.
Can some one confirm or corrent the following question?
In lk 2.4, is queuecommand() defined in low-level the only function
processing the incoming common SCSI tasks? Is it also true no matter we
send SCSI passthrough ioctl calls (with all common SCSI commands such as
INQUIRY, READ, WRITE, MODE SELECT/SENSE, PERSISTENT RESERVATION IN/OUT,
RESERVE, RELEASE, etc.) to sd devices (by using SCSI_IOCTL_SEND_COMMAND) or
to sg devices (by using either SCSI_IOCTL_SEND_COMMAND or SG_IO), or send
non-passthrough commands (such as system calls read, write, etc.) to sd