| Message ID | 20241031010032.117296-1-jmeneghi@redhat.com |
|---|---|
| Headers | show |
| Series | scsi: st: improve pos_unknown handling after reset | expand |
On 31. Oct 2024, at 3.00, John Meneghini <jmeneghi@redhat.com> wrote: > > From: Kai Makisara <kai.makisara@kolumbus.fi> > The patch in this message is a WIP patch discussed in Bugzilla. It is not meant to be submitted as such. (In addition to changes, it contains a bug fix not related to the changes.) Those interested in the progress can look at the Bugzilla entry shown below. > Fixes: 3d882cca73be ("scsi: st: Fix input/output error on empty drive reset") > Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219419 > Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ I have NOT signed of this patch. > Tested-by: John Meneghini <jmeneghi@redhat.com> John has done extensive tests to see if the patch works. > --- > drivers/scsi/st.c | 31 ++++++++++++++++++++++--------- > 1 file changed, 22 insertions(+), 9 deletions(-) > > diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c > index e9d1cb6c8a86..0260361d19fa 100644 > --- a/drivers/scsi/st.c > +++ b/drivers/scsi/st.c ...
These patches address some issues with positoin lost handling which where introduced by commit 9604eea5bd3a ("scsi: st: Add third party poweron reset handling"). That commit added code which detected any unexpected power on/reset unit attention to st_chk_results() and correclty set pos_unknown in the driver. However, the aforementioned changes is catching POR UAs that are expected as well as those that are unexpected as st_chk_results() sets pos_unknown every time a POR UA is seen. This results in a change of behavior that is confusing as some tape drives can set a POR UA when the system reboots, the driver reloads, or a tape is reloaded. This results in regressions as MTIOGET now fails following and kind of reset. These issues are documented in the kernel bugzilla: Link: https://bugzilla.kernel.org/show_bug.cgi?id=219419 A reproducer test script can be found at: Link: https://github.com/johnmeneghini/tape_tests John Meneghini (3): scsi: st: instrument the pos_unknown code scsi: st: clear was_reset when CHKRES_NEW_SESSION scsi: st: clear pos_unknown when the por ua is expected drivers/scsi/st.c | 63 ++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 54 insertions(+), 9 deletions(-)