[src/trunk]: src/sys/dev/scsipi Check in the implementation of the ST_MOUNT_D...

[mjacob <mjacob%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/59750efa54ac
branches:  trunk
changeset: 480430:59750efa54ac
user:      mjacob <mjacob%NetBSD.org@localhost>
date:      Wed Jan 12 14:46:43 2000 +0000

description:
Check in the implementation of the ST_MOUNT_DELAY option.

This is an attempt to allow people to change the default configuration
to try harder at 'mounting' a tape. This allows you to specify, in
seconds, the amount of time a non-control unit open will retry
(once per second) the scsipi_test_unit_ready when it tries to mount
the tape. It also turns off the over-verbose error reporting at
this time unless SCSIDEBUG is set.

The reason this is not enabled as a default is that it's a large change
of behaviour. I find it useful to 'try harder' at mounting a tape in
the tape driver, particularly when loaded via a media changer device
rather than specifying the delays in the backup program.

diffstat:

 sys/dev/scsipi/st.c |  119 +++++++++++++++++++++++++++++++++++++++++++++++----
 1 files changed, 108 insertions(+), 11 deletions(-)

diffs (198 lines):

diff -r 8a03ff212b58 -r 59750efa54ac sys/dev/scsipi/st.c
--- a/sys/dev/scsipi/st.c       Wed Jan 12 14:42:21 2000 +0000
+++ b/sys/dev/scsipi/st.c       Wed Jan 12 14:46:43 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: st.c,v 1.114 1999/09/30 22:57:55 thorpej Exp $ */
+/*     $NetBSD: st.c,v 1.115 2000/01/12 14:46:43 mjacob Exp $ */
 
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -72,6 +72,7 @@
 #include <sys/mtio.h>
 #include <sys/device.h>
 #include <sys/conf.h>
+#include <sys/kernel.h>
 #if NRND > 0
 #include <sys/rnd.h>
 #endif
@@ -101,6 +102,10 @@
 #define        ST_CTL_TIME     (30 * 1000)             /* 30 seconds */
 #define        ST_SPC_TIME     (4 * 60 * 60 * 1000)    /* 4 hours */
 
+#ifndef        ST_MOUNT_DELAY
+#define        ST_MOUNT_DELAY          0
+#endif
+
 /*
  * Define various devices that we know mis-behave in some way,
  * and note how they are bad, so we can correct for them
@@ -296,6 +301,9 @@
        u_int last_dsty;        /* last density opened               */
        short mt_resid;         /* last (short) resid                */
        short mt_erreg;         /* last error (sense key) seen       */
+#define        mt_key  mt_erreg
+       u_int8_t asc;           /* last asc code seen                */
+       u_int8_t ascq;          /* last asc code seen                */
 /*--------------------device/scsi parameters---------------------------------*/
        struct scsipi_link *sc_link;    /* our link to the adpter etc.       */
 /*--------------------parameters reported by the device ---------------------*/
@@ -556,9 +564,8 @@
        int mode;
        struct proc *p;
 {
-       int unit;
        u_int stmode, dsty;
-       int error;
+       int error, sflags, unit, tries, ntries;
        struct st_softc *st;
        struct scsipi_link *sc_link;
 
@@ -593,16 +600,86 @@
         */
        st->mt_resid = 0;
        st->mt_erreg = 0;
+       st->asc = 0;
+       st->ascq = 0;
+
+       /*
+        * Catch any unit attention errors. Be silent about this
+        * unless we're already mounted. We ignore media change
+        * if we're in control mode or not mounted yet.
+        */
+       if ((st->flags & ST_MOUNTED) == 0 || stmode == CTRL_MODE) {
+#ifdef SCSIDEBUG
+               sflags = XS_CTL_IGNORE_MEDIA_CHANGE;
+#else
+               sflags = XS_CTL_SILENT|XS_CTL_IGNORE_MEDIA_CHANGE;
+#endif
+       } else
+               sflags = 0;
 
        /*
-        * Catch any unit attention errors.
+        * If we're already mounted or we aren't configured for
+        * a mount delay, only try a test unit ready once. Otherwise,
+        * try up to ST_MOUNT_DELAY times with a rest interval of
+        * one second between each try.
         */
-       error = scsipi_test_unit_ready(sc_link, XS_CTL_IGNORE_MEDIA_CHANGE |
-           (stmode == CTRL_MODE ? XS_CTL_SILENT : 0));
-       if (error && stmode != CTRL_MODE) {
-               goto bad;
+
+       if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0) {
+               ntries = 1;
+       } else {
+               ntries = ST_MOUNT_DELAY;
        }
-       sc_link->flags |= SDEV_OPEN;    /* unit attn are now errors */
+
+       for (error = tries = 0; tries < ntries; tries++) {
+               int slpintr, oflags;
+
+               /*
+                * If we had no error, or we're opening the control mode
+                * device, we jump out right away.
+                */
+
+               error = scsipi_test_unit_ready(sc_link, sflags);
+               if (error == 0 || stmode == CTRL_MODE) {
+                       break;
+               }
+
+               /*
+                * We had an error.
+                *
+                * If we're already mounted or we aren't configured for
+                * a mount delay, or the error isn't a NOT READY error,
+                * skip to the error exit now.
+                */
+               if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0 ||
+                   (st->mt_key != SKEY_NOT_READY)) {
+                       goto bad;
+               }
+
+               /*
+                * clear any latched errors.
+                */
+               st->mt_resid = 0;
+               st->mt_erreg = 0;
+               st->asc = 0;
+               st->ascq = 0;
+
+               /*
+                * Fake that we have the device open so
+                * we block other apps from getting in.
+                */
+
+               oflags = sc_link->flags;
+               sc_link->flags |= SDEV_OPEN;
+
+               slpintr = tsleep(&lbolt, PUSER|PCATCH, "stload", 0);
+
+               sc_link->flags = oflags;        /* restore flags */
+
+               if (slpintr) {
+                       goto bad;
+               }
+       } 
+
 
        /*
         * If the mode is 3 (e.g. minor = 3,7,11,15) then the device has
@@ -612,11 +689,27 @@
         * as to whether or not we got a NOT READY for the above
         * unit attention). If a tape is there, go do a mount sequence.
         */
-       if (stmode == CTRL_MODE && st->mt_erreg == SKEY_NOT_READY) {
+       if (stmode == CTRL_MODE && st->mt_key == SKEY_NOT_READY) {
+               sc_link->flags |= SDEV_OPEN;
                return (0);
        }
 
        /*
+        * If we get this far and had an error set, that means we failed
+        * to pass the 'test unit ready' test for the non-controlmode device,
+        * so we bounce the open.
+        */
+
+       if (error)
+               return (error);
+
+       /*
+        * Else, we're now committed to saying we're open.
+        */
+
+       sc_link->flags |= SDEV_OPEN;    /* unit attn are now errors */
+
+       /*
         * If it's a different mode, or if the media has been
         * invalidated, unmount the tape from the previous
         * session but continue with open processing
@@ -764,7 +857,7 @@
         * If the media is new, then make sure we give it a chance to
         * to do a 'load' instruction.  (We assume it is new.)
         */
-       if ((error = st_load(st, LD_LOAD, 0)) != 0)
+       if ((error = st_load(st, LD_LOAD, XS_CTL_SILENT)) != 0)
                return (error);
        /*
         * Throw another dummy instruction to catch
@@ -1299,6 +1392,8 @@
                 */
                st->mt_resid = 0;
                st->mt_erreg = 0;
+               st->asc = 0;
+               st->ascq = 0;
                break;
        }
        case MTIOCTOP: {
@@ -2209,6 +2304,8 @@
                info = xs->datalen;     /* bad choice if fixed blocks */
        key = sense->flags & SSD_KEY;
        st->mt_erreg = key;
+       st->asc = sense->add_sense_code;
+       st->ascq = sense->add_sense_code_qual;
        st->mt_resid = (short) info;
 
        /*