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/*
* Mach Operating System
* Copyright (c) 1991,1990 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
/*
* File: rz_disk_bbr.c
* Author: Alessandro Forin, Carnegie Mellon University
* Date: 4/91
*
* Top layer of the SCSI driver: interface with the MI.
* This file contains bad-block management functions
* (retry, replace) for disk-like devices.
*/
#include <mach/std_types.h>
#include <scsi/compat_30.h>
#include <scsi/scsi.h>
#include <scsi/scsi_defs.h>
#include <scsi/rz.h>
#if (NSCSI > 0)
int scsi_bbr_retries = 10;
#define BBR_ACTION_COMPLETE 1
#define BBR_ACTION_RETRY_READ 2
#define BBR_ACTION_REASSIGN 3
#define BBR_ACTION_COPY 4
#define BBR_ACTION_VERIFY 5
static void make_msf(); /* forward */
/*
* Bad block replacement routine, invoked on
* unrecovereable disk read/write errors.
*/
boolean_t
scdisk_bad_block_repl(tgt, blockno)
target_info_t *tgt;
unsigned int blockno;
{
register io_req_t ior = tgt->ior;
if (scsi_no_automatic_bbr || (ior->io_op & IO_INTERNAL))
return FALSE;
/* signal we took over */
tgt->flags |= TGT_BBR_ACTIVE;
printf("%s", "Attempting bad block replacement..");
tgt->dev_info.disk.b.badblockno = blockno;
tgt->dev_info.disk.b.retry_count = 0;
tgt->dev_info.disk.b.save_rec = ior->io_recnum;
tgt->dev_info.disk.b.save_addr = ior->io_data;
tgt->dev_info.disk.b.save_count = ior->io_count;
tgt->dev_info.disk.b.save_resid = ior->io_residual;
/*
* On a write all we need is to rewire the offending block.
* Note that the sense data identified precisely which 512 sector
* is bad. At the end we'll retry the entire write, so if there
* is more than one bad sector involved they will be handled one
* at a time.
*/
if ((ior->io_op & IO_READ) == 0) {
char msf[sizeof(int)];
ior->io_temporary = BBR_ACTION_COMPLETE;
printf("%s", "just reassign..");
make_msf(msf,blockno);
scsi_reassign_blocks( tgt, msf, 1, ior);
} else
/*
* This is more complicated. We asked for N bytes, and somewhere
* in there there is a chunk of bad data. First off, we should retry
* at least a couple of times to retrieve that data [yes the drive
* should have done its best already so what]. If that fails we
* should recover as much good data as possible (before the bad one).
*/
{
ior->io_temporary = BBR_ACTION_RETRY_READ;
printf("%s", "retry read..");
ior->io_residual = 0;
scdisk_start_rw(tgt, ior);
}
return TRUE;
}
static
void make_msf(buf,val)
unsigned char *buf;
unsigned int val;
{
*buf++ = val >> 24;
*buf++ = val >> 16;
*buf++ = val >> 8;
*buf++ = val >> 0;
}
/*
* This effectively replaces the strategy routine during bbr.
*/
void scdisk_bbr_start( tgt, done)
target_info_t *tgt;
boolean_t done;
{
register io_req_t ior = tgt->ior;
char *msg;
switch (ior->io_temporary) {
case BBR_ACTION_COMPLETE:
/* all done, either way */
fin:
tgt->flags &= ~TGT_BBR_ACTIVE;
ior->io_recnum = tgt->dev_info.disk.b.save_rec;
ior->io_data = tgt->dev_info.disk.b.save_addr;
ior->io_count = tgt->dev_info.disk.b.save_count;
ior->io_residual = tgt->dev_info.disk.b.save_resid;
if (tgt->done == SCSI_RET_SUCCESS) {
/* restart normal life */
register unsigned int xferred;
if (xferred = ior->io_residual) {
ior->io_data -= xferred;
ior->io_count += xferred;
ior->io_recnum -= xferred / tgt->block_size;
ior->io_residual = 0;
}
/* from the beginning */
ior->io_error = 0;
msg = "done, restarting.";
} else {
/* we could not fix it. Tell user and give up */
tgt->ior = ior->io_next;
iodone(ior);
msg = "done, but could not recover.";
}
printf("%s\n", msg);
scdisk_start( tgt, FALSE);
return;
case BBR_ACTION_RETRY_READ:
/* see if retry worked, if not do it again */
if (tgt->done == SCSI_RET_SUCCESS) {
char msf[sizeof(int)];
/* whew, retry worked. Now rewire that bad block
* and don't forget to copy the good data over */
tgt->dev_info.disk.b.retry_count = 0;
printf("%s", "ok now, reassign..");
ior->io_temporary = BBR_ACTION_COPY;
make_msf(msf, tgt->dev_info.disk.b.badblockno);
scsi_reassign_blocks( tgt, msf, 1, ior);
return;
}
if (tgt->dev_info.disk.b.retry_count++ < scsi_bbr_retries) {
scdisk_start_rw( tgt, ior);
return;
}
/* retrying was hopeless. Leave the bad block there for maintainance */
/* because we do not know what to write on it */
printf("%s%d%s", "failed after ", scsi_bbr_retries, " retries..");
goto fin;
case BBR_ACTION_COPY:
/* retrying succeded and we rewired the bad block. */
if (tgt->done == SCSI_RET_SUCCESS) {
unsigned int tmp;
struct diskpart *label;
printf("%s", "ok, rewrite..");
/* writeback only the bad sector */
/* map blockno back to partition offset */
/* !!! partition code changes: */
tmp = rzpartition(ior->io_unit);
/* label=lookup_part(array, tmp +1); */
tmp = tgt->dev_info.disk.b.badblockno -
/* label->start; */
/* #if 0 */
tgt->dev_info.disk.l.d_partitions[tmp].p_offset;
/* #endif 0 */
ior->io_data += (tmp - ior->io_recnum) * tgt->block_size;
ior->io_recnum = tmp;
ior->io_count = tgt->block_size;
ior->io_op &= ~IO_READ;
ior->io_temporary = BBR_ACTION_VERIFY;
scdisk_start_rw( tgt, ior);
} else {
/* either unsupported command, or repl table full */
printf("%s", "reassign failed (really needs reformatting), ");
ior->io_error = 0;
goto fin;
}
break;
case BBR_ACTION_VERIFY:
if (tgt->done == SCSI_RET_SUCCESS) {
ior->io_op |= IO_READ;
goto fin;
}
if (tgt->dev_info.disk.b.retry_count++ > scsi_bbr_retries) {
printf("%s%d%s", "failed after ",
scsi_bbr_retries, " retries..");
ior->io_op |= IO_READ;
goto fin;
}
/* retry, we are *this* close to success.. */
scdisk_start_rw( tgt, ior);
break;
case BBR_ACTION_REASSIGN:
/* if we wanted to issue the reassign multiple times */
/* XXX unimplemented XXX */
default: /* snafu */
panic("scdisk_bbr_start");
}
}
#endif /* NSCSI > 0 */
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