| Message ID | CA+-=Uwah2MS_aD+PeSBkQa_=1wCD+3=g6W4PvLnbJ_-px8G97g@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
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Patrick, > Values greater than 0x7FFFFF do not fit in the 24 bit big endian two's > complement integer for the underlying scsi SPACE(6) command. I was hoping Kai would chime in. However, since SPACE(6) has been deprecated for a while, I am not so keen on blindly enforcing this in the ioctl interface. I would rather see SPACE(16) support added and then have the supplied count value be validated based on whether the 6 or 16 byte command is being issued to the device. -- Martin K. Petersen Oracle Linux Engineering
I'm happy to implement SPACE(16) instead. I believe the opcode for SPACE(16) is 0x91, but in include/scsi/scsi_proto.h that value is listed as SYNCHRONIZE_CACHE_16. I couldn't figure out which was wrong, so I proposed this to at least prevent the interface from doing the wrong thing. On Tue, Jan 26, 2021 at 11:26 PM Martin K. Petersen <martin.petersen@oracle.com> wrote: > > > Patrick, > > > Values greater than 0x7FFFFF do not fit in the 24 bit big endian two's > > complement integer for the underlying scsi SPACE(6) command. > > I was hoping Kai would chime in. > > However, since SPACE(6) has been deprecated for a while, I am not so > keen on blindly enforcing this in the ioctl interface. I would rather > see SPACE(16) support added and then have the supplied count value be > validated based on whether the 6 or 16 byte command is being issued to > the device. > > -- > Martin K. Petersen Oracle Linux Engineering
Patrick, > I believe the opcode for SPACE(16) is 0x91, That is correct. > but in include/scsi/scsi_proto.h that value is listed as > SYNCHRONIZE_CACHE_16. Yeah, I'm afraid things have a tendency to be SPC/SBC centric. Feel free to add SPACE(16) and make a comment about the SSC vs. SBC distinction. -- Martin K. Petersen Oracle Linux Engineering
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c index 43f7624508a9..190fa678d149 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c @@ -2719,6 +2719,22 @@ static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned lon blkno = STps->drv_block; at_sm = STps->at_sm; + switch (cmd_in) { + case MTFSFM: + case MTFSF: + case MTBSFM: + case MTBSF: + case MTFSR: + case MTBSR: + case MTFSS: + case MTBSS: + // count field for SPACE(6) is a 24 bit big endian two's complement integer + if (arg > 0x7FFFFF) { + st_printk(ST_DEB_MSG, STp, "Cannot space more than 0x7FFFFF units.\n"); + return (-EINVAL); + } + } +
Values greater than 0x7FFFFF do not fit in the 24 bit big endian two's complement integer for the underlying scsi SPACE(6) command. Signed-off-by: Patrick Strateman <patrick.strateman@gmail.com> --- drivers/scsi/st.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) memset(cmd, 0, MAX_COMMAND_SIZE); switch (cmd_in) { case MTFSFM: