> On 22. Aug 2023, at 21.14, John Meneghini <jmeneghi@xxxxxxxxxx> wrote: > > Handle the unexpected condition where the tape drive reports > that tape is rewinding. > > ... > I'm providing this patch because I think it's valuable for testing > purposes and it should be safe. Any time the device unexpectedly > reports "Rewind is in progress", it should be safe to set > pos_unknown in the driver. > I am a bit hesitant about this, because it does not recognize if the rewind in progress was initiated by the user or not. In immediate mode (ST_NOWAIT option), a user rewind may be still in progress when a (impatient) user tries to do something else. One possibility would be to make this conditional on !STp->immediate. Another, perhaps better, method would be to use the STps->rw state variable. A new state ST_REWINDING could be introduced (or state should be set to ST_IDLE when rewinding). (Looking at the state, I think it should be set to something else than ST_WRITING more frequently. This could, in some cases prevent improper automatic writing of filemarks. See, for instance, the problem with failing rewinds in the report with PATCH 1/2.) Thanks, Kai > Tested-by: Laurence Oberman <loberman@xxxxxxxxxx> > Signed-off-by: John Meneghini <jmeneghi@xxxxxxxxxx> > --- > drivers/scsi/st.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c > index 338aa8c42968..b641490ed9d1 100644 > --- a/drivers/scsi/st.c > +++ b/drivers/scsi/st.c > @@ -416,6 +416,9 @@ static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt) > STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */ > if (cmdstatp->have_sense && scode == UNIT_ATTENTION && cmdstatp->sense_hdr.asc == 0x29) > STp->pos_unknown = 1; /* ASC => power on / reset */ > + if (cmdstatp->have_sense && cmdstatp->sense_hdr.asc == 0 > + && cmdstatp->sense_hdr.ascq == 0x1a) > + STp->pos_unknown = 1; /* ASCQ => rewind in progress */ > > STp->pos_unknown |= STp->device->was_reset; > > -- > 2.39.3 >
