/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * This file contains routines to analyze the surface of a disk.
 */
#include "global.h"
#include "analyze.h"
#include <stdlib.h>
#include <errno.h>
#include "misc.h"
#include "defect.h"
#include "label.h"
#include "param.h"
#include "checkdev.h"


/*
 * These global variables control the surface analysis process.  They
 * are set from a command in the defect menu.
 */
int     scan_entire = 1;                /* scan whole disk flag */
diskaddr_t      scan_lower = 0;                 /* lower bound */
diskaddr_t      scan_upper = 0;                 /* upper bound */
int     scan_correct = 1;               /* correct errors flag */
int     scan_stop = 0;                  /* stop after error flag */
int     scan_loop = 0;                  /* loop forever flag */
int     scan_passes = 2;                /* number of passes */
int     scan_random = 0;                /* random patterns flag */
uint_t  scan_size = 0;                  /* sectors/scan operation */
int     scan_auto = 1;                  /* scan after format flag */
int     scan_restore_defects = 1;       /* restore defect list after writing */
int     scan_restore_label = 1;         /* restore label after writing */

/*
 * These are summary variables to print out info after analysis.
 * Values less than 0 imply they are invalid.
 */
offset_t        scan_cur_block = -1;            /* current block */
int64_t         scan_blocks_fixed = -1;         /* # blocks repaired */

/*
 * This variable is used to tell whether the most recent surface
 * analysis error was caused by a media defect or some other problem.
 */
int     media_error;                    /* error was caused by defect */

int     disk_error;                     /* disk errors during analysis */

/*
 * These are the data patterns used if random patterns are not chosen.
 * They are designed to show pattern dependent errors.
 */
static unsigned int     scan_patterns[] = {
        0xc6dec6de,
        0x6db6db6d,
        0x00000000,
        0xffffffff,
        0xaaaaaaaa,
};
#define NPATTERNS       5               /* number of predefined patterns */

/*
 * These are the data patterns from the SunFed requirements document.
 */
static unsigned int purge_patterns[] = {        /* patterns to be written */
        0xaaaaaaaa,             /* 10101010... */
        0x55555555,             /* 01010101...  == UUUU... */
        0xaaaaaaaa,             /* 10101010... */
        0xaaaaaaaa,             /* 10101010... */
};

static unsigned int alpha_pattern =  0x40404040;   /* 10000000...  == @@@@... */

static int      scan_repair(diskaddr_t bn, int mode);
static int      analyze_blocks(int flags, diskaddr_t blkno, uint_t blkcnt,
                unsigned data, int init, int driver_flags, int *xfercntp);
static int      handle_error_conditions(void);
static int      verify_blocks(int flags, diskaddr_t blkno, uint_t blkcnt,
                unsigned data, int driver_flags, int *xfercntp);

/*
 * This routine performs a surface analysis based upon the global
 * parameters.  It is called from several commands in the defect menu,
 * and from the format command in the command menu (if post-format
 * analysis is enable).
 */
int
do_scan(int flags, int mode)
{
        diskaddr_t      start, end, curnt;
        int     pass, needinit, data;
        uint_t  size;
        int     status, founderr, i, j;
        int     error = 0;
        int     pattern = 0;
        int     xfercnt;

        /*
         * Check to be sure we aren't correcting without a defect list
         * if the controller can correct the defect.
         */
        if (scan_correct && !EMBEDDED_SCSI && (cur_ops->op_repair != NULL) &&
            (cur_list.list == NULL)) {
                err_print("Current Defect List must be initialized ");
                err_print("to do automatic repair.\n");
                return (-1);
        }
        /*
         * Define the bounds of the scan.
         */
        if (scan_entire) {
                start = 0;
                if (cur_label == L_TYPE_SOLARIS) {
                        if (cur_ctype->ctype_flags & CF_SCSI)
                                end = datasects() - 1;
                        else
                                end = physsects() - 1;
                } else if (cur_label == L_TYPE_EFI) {
                        end = cur_parts->etoc->efi_last_lba;
                }
        } else {
                start = scan_lower;
                end = scan_upper;
        }
        /*
         * Make sure the user knows if we are scanning over a mounted
         * partition.
         */
        if ((flags & (SCAN_PATTERN | SCAN_WRITE)) &&
            (checkmount(start, end))) {
                err_print("Cannot do analysis on a mounted partition.\n");
                return (-1);
        }

        /*
         * Make sure the user knows if we are scanning over a
         * partition being used for swapping.
         */
        if ((flags & (SCAN_PATTERN | SCAN_WRITE)) &&
            (checkswap(start, end))) {
                err_print("Cannot do analysis on a partition \
                    which is currently being used for swapping.\n");
                return (-1);
        }

        /*
         * Check to see if any partitions used for svm, vxvm, ZFS zpool
         * or live upgrade are on the disk.
         */
        if ((flags & (SCAN_PATTERN | SCAN_WRITE)) &&
            (checkdevinuse(cur_disk->disk_name, (diskaddr_t)-1,
            (diskaddr_t)-1, 0, 0))) {
                err_print("Cannot do analysis on a partition "
                    "while it in use as described above.\n");
                return (-1);
        }

        /*
         * If we are scanning destructively over certain sectors,
         * we mark the defect list and/or label dirty so it will get rewritten.
         */
        if (flags & (SCAN_PATTERN | SCAN_WRITE)) {
                if (cur_label == L_TYPE_SOLARIS) {
                        if (start < (diskaddr_t)totalsects() &&
                            end >= (diskaddr_t)datasects()) {
                                if (!EMBEDDED_SCSI) {
                                        cur_list.flags |= LIST_DIRTY;
                                }
                                if (cur_disk->disk_flags & DSK_LABEL)
                                        cur_flags |= LABEL_DIRTY;
                        }
                }
                if (start == 0) {
                        if (cur_disk->disk_flags & DSK_LABEL)
                                cur_flags |= LABEL_DIRTY;
                }
        }
        /*
         * Initialize the summary info on sectors repaired.
         */
        scan_blocks_fixed = 0;
        /*
         * Loop through the passes of the scan. If required, loop forever.
         */
        for (pass = 0; pass < scan_passes || scan_loop; pass++) {
                /*
                 * Determine the data pattern to use if pattern testing
                 * is to be done.
                 */
                if (flags & SCAN_PATTERN) {
                        if (scan_random)
                                data = (int)mrand48();
                        else
                                data = scan_patterns[pass % NPPATTERNS];

                        if (flags & SCAN_PURGE) {
                                flags &= ~(SCAN_PURGE_READ_PASS
                                    | SCAN_PURGE_ALPHA_PASS);
                                switch (pattern % (NPPATTERNS + 1)) {
                                case NPPATTERNS:
                                        pattern = 0;
                                        if (!error) {
                                                fmt_print(
"\nThe last %d passes were successful, running alpha pattern pass", NPPATTERNS);
                                                flags |= SCAN_PURGE_ALPHA_PASS;
                                                data = alpha_pattern;
                                        } else {
                                                data = purge_patterns[pattern];
                                                pattern++;
                                        };
                                        break;
                                case READPATTERN:
                                        flags |=  SCAN_PURGE_READ_PASS;
                                        /* FALLTHROUGH */
                                default:
                                        data = purge_patterns[pattern];
                                        pattern++;
                                        break;
                                }
                        }
                        fmt_print("\n        pass %d", pass);
                        fmt_print(" - pattern = 0x%x", data);
                } else
                        fmt_print("\n        pass %d", pass);

                fmt_print("\n");
                /*
                 * Mark the pattern buffer as corrupt, since it
                 * hasn't been initialized.
                 */
                needinit = 1;
                /*
                 * Print the first block number to the log file if
                 * logging is on so there is some record of what
                 * analysis was performed.
                 */
                if (log_file) {
                        pr_dblock(log_print, start);
                        log_print("\n");
                }
                /*
                 * Loop through this pass, each time analyzing an amount
                 * specified by the global parameters.
                 */
                xfercnt = 0;
                for (curnt = start; curnt <= end; curnt += size) {
                        if ((end - curnt) < scan_size)
                                size = end - curnt + 1;
                        else
                                size = scan_size;
                        /*
                         * Print out where we are, so we don't look dead.
                         * Also store it in summary info for logging.
                         */
                        scan_cur_block = curnt;
                        nolog_print("   ");
                        pr_dblock(nolog_print, curnt);
                        nolog_print("  \015");
                        (void) fflush(stdout);
                        disk_error = 0;
                        /*
                         * Do the actual analysis.
                         */
                        status = analyze_blocks(flags, curnt, size,
                            (unsigned)data, needinit, (F_ALLERRS | F_SILENT),
                            &xfercnt);
                        /*
                         * If there were no errors, the pattern buffer is
                         * still initialized, and we just loop to next chunk.
                         */
                        needinit = 0;
                        if (!status)
                                continue;
                        /*
                         * There was an error. Check if surface analysis
                         * can be continued.
                         */
                        if (handle_error_conditions()) {
                                scan_blocks_fixed = scan_cur_block = -1;
                                return (-1);
                        }
                        /*
                         * There was an error. Mark the pattern buffer
                         * corrupt so it will get reinitialized.
                         */
                        needinit = 1;
                        /*
                         * If it was not a media error, ignore it.
                         */
                        if (!media_error)
                                continue;
                        /*
                         * Loop 5 times through each sector of the chunk,
                         * analyzing them individually.
                         */
                        nolog_print("   ");
                        pr_dblock(nolog_print, curnt);
                        nolog_print("  \015");
                        (void) fflush(stdout);
                        founderr = 0;
                        for (j = 0; j < size * 5; j++) {
                                i = j % size;
                                disk_error = 0;
                                status = analyze_blocks(flags, (curnt + i), 1,
                                    (unsigned)data, needinit, F_ALLERRS, NULL);
                                needinit = 0;
                                if (!status)
                                        continue;
                                /*
                                 * There was an error. Check if surface analysis
                                 * can be continued.
                                 */
                                if (handle_error_conditions()) {
                                        scan_blocks_fixed = scan_cur_block = -1;
                                        return (-1);
                                }
                                /*
                                 * An error occurred.  Mark the buffer
                                 * corrupt and see if it was media
                                 * related.
                                 */
                                needinit = 1;
                                if (!media_error)
                                        continue;
                                /*
                                 * We found a bad sector. Print out a message
                                 * and fix it if required.
                                 */
                                founderr = 1;
                                if (scan_correct && (flags != SCAN_VALID)) {
                                        if (scan_repair(curnt+i, mode)) {
                                                error = -1;
                                        }
                                } else
                                        err_print("\n");
                                /*
                                 * Stop after the error if required.
                                 */
                                if (scan_stop)
                                        goto out;
                        }
                        /*
                         * Mark the pattern buffer corrupt to be safe.
                         */
                        needinit = 1;
                        /*
                         * We didn't find an individual sector that was bad.
                         * Print out a warning.
                         */
                        if (!founderr) {
                                err_print("Warning: unable to pinpoint ");
                                err_print("defective block.\n");
                        }
                }
                /*
                 * Print the end of each pass to the log file.
                 */
                enter_critical();
                if (log_file) {
                        pr_dblock(log_print, scan_cur_block);
                        log_print("\n");
                }
                scan_cur_block = -1;
                exit_critical();
                fmt_print("\n");

                /*
                 * alternate the read and write for SCAN_VERIFY test
                 */
                if (flags & SCAN_VERIFY) {
                        flags ^= SCAN_VERIFY_READ_PASS;
                }
        }
out:
        /*
         * We got here either by giving up after an error or falling
         * through after all passes were completed.
         */
        fmt_print("\n");
        enter_critical();
        /*
         * If the defect list is dirty, write it to disk,
         * if scan_restore_defects (the default) is true.
         */
        if (!EMBEDDED_SCSI && (cur_list.flags & LIST_DIRTY) &&
            (scan_restore_defects)) {
                cur_list.flags = 0;
                write_deflist(&cur_list);
                }
        /*
         * If the label is dirty, write it to disk.
         * if scan_restore_label (the default) is true.
         */
        if ((cur_flags & LABEL_DIRTY) && (scan_restore_label)) {
                cur_flags &= ~LABEL_DIRTY;
                (void) write_label();
        }
        /*
         * If we dropped down to here after an error, we need to write
         * the final block number to the log file for record keeping.
         */
        if (log_file && scan_cur_block >= 0) {
                pr_dblock(log_print, scan_cur_block);
                log_print("\n");
        }
        fmt_print("Total of %lld defective blocks repaired.\n",
            scan_blocks_fixed);
        /*
         * Reinitialize the logging variables so they don't get used
         * when they are not really valid.
         */
        scan_blocks_fixed = scan_cur_block = -1;
        exit_critical();
        return (error);
}


/*
 * This routine is called to repair a bad block discovered
 * during a scan operation.  Return 0 for success, 1 for failure.
 * (This has been extracted out of do_scan(), to simplify it.)
 */
static int
scan_repair(diskaddr_t bn, int mode)
{
        int     status;
        int     result = 1;
        char    *buf;
        int     buf_is_good;
        int     i;

        if (cur_ops->op_repair == NULL) {
                err_print("Warning: Controller does ");
                err_print("not support repairing.\n\n");
                return (result);
        }

        buf = malloc(cur_blksz);
        if (buf == NULL) {
                err_print("Warning: no memory.\n\n");
                return (result);
        }
        enter_critical();

        /*
         * Determine if the error appears to be hard or soft.  We
         * already assume there's an error.  If we can get any
         * good data out of the sector, write that data back
         * after the repair.
         */
        buf_is_good = 0;
        for (i = 0; i < 5; i++) {
                status = (*cur_ops->op_rdwr)(DIR_READ, cur_file, bn, 1,
                    buf, F_SILENT, NULL);
                if (status == 0) {
                        buf_is_good = 1;
                        break;
                }
        }

        fmt_print("Repairing %s error on %llu (",
            buf_is_good ? "soft" : "hard", bn);
        pr_dblock(fmt_print, bn);
        fmt_print(")...");

        status = (*cur_ops->op_repair)(bn, mode);
        if (status) {
                /*
                 * If the repair failed, we note it and will return the
                 * failure. However, the analysis goes on.
                 */
                fmt_print("failed.\n\n");
        } else {
                /*
                 * The repair worked.  Write the good data we could
                 * recover from the failed block, if possible.
                 * If not, zero the block.  In doing so, try to
                 * determine if the new block appears ok.
                 */
                if (!buf_is_good) {
                        bzero(buf, cur_blksz);
                        fmt_print("Warning: Block %llu zero-filled.\n", bn);
                } else {
                        fmt_print("ok.\n");
                }
                status = (*cur_ops->op_rdwr)(DIR_WRITE, cur_file, bn,
                    1, buf, (F_SILENT | F_ALLERRS), NULL);
                if (status == 0) {
                        status = (*cur_ops->op_rdwr)(DIR_READ, cur_file, bn,
                            1, buf, (F_SILENT | F_ALLERRS), NULL);
                }
                if (status) {
                        fmt_print("The new block also appears defective.\n");
                }
                fmt_print("\n");
                /*
                 * add the defect to the list and write the list out.
                 * Also, kill the working list so it will get resynced
                 * with the current list.
                 *
                 * For embedded scsi, we don't require a defect list.
                 * However, if we have one, add the defect if the
                 * list includes the grown list.  If not, kill it
                 * to force a resync if we need the list later.
                 */
                if (EMBEDDED_SCSI) {
                        if (cur_list.list != NULL) {
                                if (cur_list.flags & LIST_PGLIST) {
                                        add_ldef(bn, &cur_list);
                                } else {
                                        kill_deflist(&cur_list);
                                }
                        }
                /*
                 * The next "if" statement reflects the fix for
                 * bug id 1026096 where format keeps adding the
                 * same defect to the defect list.
                 */
                } else if (cur_ctype->ctype_flags & CF_WLIST) {
                        kill_deflist(&cur_list);
                        (*cur_ops->op_ex_cur)(&cur_list);
                        fmt_print("Current list updated\n");
                } else {
                        add_ldef(bn, &cur_list);
                        write_deflist(&cur_list);
                }
                kill_deflist(&work_list);

                /* Log the repair.  */
                scan_blocks_fixed++;

                /* return ok */
                result = 0;
        }

        exit_critical();
        free(buf);
        return (result);
}


/*
 * This routine analyzes a set of sectors on the disk.  It simply returns
 * an error if a defect is found.  It is called by do_scan().
 */
static int
analyze_blocks(int flags, diskaddr_t blkno, uint_t blkcnt, unsigned data,
    int init, int driver_flags, int *xfercntp)
{
        int             corrupt = 0;
        int             status;
        diskaddr_t      i, nints;
        unsigned *ptr = (uint_t *)pattern_buf;

        media_error = 0;
        if (flags & SCAN_VERIFY) {
                return (verify_blocks(flags, blkno, blkcnt, data,
                    driver_flags, xfercntp));
        }

        /*
         * Initialize the pattern buffer if necessary.
         */
        nints = (diskaddr_t)blkcnt * cur_blksz / sizeof (int);
        if ((flags & SCAN_PATTERN) && init) {
                for (i = 0; i < nints; i++)
                        *((int *)((int *)pattern_buf + i)) = data;
        }
        /*
         * Lock out interrupts so we can insure valid data will get
         * restored. This is necessary because there are modes
         * of scanning that corrupt the disk data then restore it at
         * the end of the analysis.
         */
        enter_critical();
        /*
         * If the disk data is valid, read it into the data buffer.
         */
        if (flags & SCAN_VALID) {
                status = (*cur_ops->op_rdwr)(DIR_READ, cur_file, blkno,
                    blkcnt, (caddr_t)cur_buf, driver_flags, xfercntp);
                if (status)
                        goto bad;
        }
        /*
         * If we are doing pattern testing, write and read the pattern
         * from the pattern buffer.
         */
        if (flags & SCAN_PATTERN) {
                /*
                 * If the disk data was valid, mark it corrupt so we know
                 * to restore it later.
                 */
                if (flags & SCAN_VALID)
                        corrupt++;
                /*
                 * Only write if we're not on the read pass of SCAN_PURGE.
                 */
                if (!(flags & SCAN_PURGE_READ_PASS)) {
                        status = (*cur_ops->op_rdwr)(DIR_WRITE, cur_file, blkno,
                            blkcnt, (caddr_t)pattern_buf, driver_flags,
                            xfercntp);
                        if (status)
                                goto bad;
                }
                /*
                 * Only read if we are on the read pass of SCAN_PURGE, if we
                 * are purging.
                 */
                if ((!(flags & SCAN_PURGE)) || (flags & SCAN_PURGE_READ_PASS)) {
                        status = (*cur_ops->op_rdwr)(DIR_READ, cur_file, blkno,
                            blkcnt, (caddr_t)pattern_buf, driver_flags,
                            xfercntp);
                        if (status)
                                goto bad;
                }
        }
        /*
         * If we are doing a data compare, make sure the pattern
         * came back intact.
         * Only compare if we are on the read pass of SCAN_PURGE, or
         * we wrote random data instead of the expected data pattern.
         */
        if ((flags & SCAN_COMPARE) || (flags & SCAN_PURGE_READ_PASS)) {
                for (i = nints, ptr = (uint_t *)pattern_buf; i; i--)
                        if (*ptr++ != data) {
                                err_print("Data miscompare error (expecting ");
                                err_print("0x%x, got 0x%x) at ", data,
                                    *((int *)((int *)pattern_buf +
                                    (nints - i))));
                                pr_dblock(err_print, blkno);
                                err_print(", offset = 0x%llx.\n",
                                    (nints - i) * sizeof (int));
                                goto bad;
                        }
        }
        /*
         * If we are supposed to write data out, do so.
         */
        if (flags & SCAN_WRITE) {
                status = (*cur_ops->op_rdwr)(DIR_WRITE, cur_file, blkno,
                    blkcnt, (caddr_t)cur_buf, driver_flags, xfercntp);
                if (status)
                        goto bad;
        }
        exit_critical();
        /*
         * No errors occurred, return ok.
         */
        return (0);
bad:
        /*
         * There was an error.  If the data was corrupted, we write it
         * out from the data buffer to restore it.
         */
        if (corrupt) {
                if ((*cur_ops->op_rdwr)(DIR_WRITE, cur_file, blkno,
                    blkcnt, (caddr_t)cur_buf, F_NORMAL, xfercntp))
                err_print("Warning: unable to restore original data.\n");
        }
        exit_critical();
        /*
         * Return the error.
         */
        return (-1);
}


/*
 * This routine analyzes a set of sectors on the disk. It simply returns
 * an error if a defect is found.  It is called by analyze_blocks().
 * For simplicity, this is done as a separate function instead of
 * making the analyze_block routine complex.
 *
 * This routine implements the 'verify' command.  It writes the disk
 * by writing unique data for each block; after the write pass, it
 * reads the data and verifies for correctness. Note that the entire
 * disk (or the range of disk) is fully written first and then read.
 * This should eliminate any caching effect on the drives.
 */
static int
verify_blocks(int flags, diskaddr_t blkno, uint_t blkcnt, unsigned data,
    int driver_flags, int *xfercntp)
{
        int             status, i, nints;
        unsigned        *ptr = (uint_t *)pattern_buf;

        nints = cur_blksz / sizeof (int);

        /*
         * Initialize the pattern buffer if we are in write pass.
         * Use the block number itself as data, each block has unique
         * buffer data that way.
         */
        if (!(flags & SCAN_VERIFY_READ_PASS)) {
                for (data = blkno; data < blkno + blkcnt; data++) {
                        for (i = 0; i < nints; i++) {
                                *ptr++ = data;
                        }
                }
                ptr = (uint_t *)pattern_buf;
        }

        /*
         * Only write if we're not on the read pass of SCAN_VERIFY.
         */
        if (!(flags & SCAN_VERIFY_READ_PASS)) {
                status = (*cur_ops->op_rdwr)(DIR_WRITE, cur_file, blkno,
                    blkcnt, (caddr_t)pattern_buf, driver_flags, xfercntp);
                if (status)
                        goto bad;
        } else {
                /*
                 * Only read if we are on the read pass of SCAN_VERIFY
                 */
                status = (*cur_ops->op_rdwr)(DIR_READ, cur_file, blkno,
                    blkcnt, (caddr_t)pattern_buf, driver_flags, xfercntp);
                if (status)
                        goto bad;
                /*
                 * compare and make sure the pattern came back intact.
                 */
                for (data = blkno; data < blkno + blkcnt; data++) {
                        for (i = 0; i < nints; i++) {
                                if (*ptr++ != data) {
                                        ptr--;
                                        err_print("Data miscompare error "
                                            "(expecting 0x%x, got 0x%x) at ",
                                            data, *ptr);
                                        pr_dblock(err_print, blkno);
                                        err_print(", offset = 0x%x.\n",
                                            (ptr - (uint_t *)pattern_buf) *
                                            sizeof (int));
                                        goto bad;
                                }
                        }
                }
        }
        /*
         * No errors occurred, return ok.
         */
        return (0);
bad:
        return (-1);
}


static int
handle_error_conditions(void)
{

        /*
         * Check if the errno is ENXIO.
         */
        if (errno == ENXIO) {
                fmt_print("\n\nWarning:Cannot access drive, ");
                fmt_print("aborting surface analysis.\n");
                return (-1);
        }
        /*
         * check for disk errors
         */
        switch (disk_error) {
        case DISK_STAT_RESERVED:
        case DISK_STAT_UNAVAILABLE:
                fmt_print("\n\nWarning:Drive may be reserved ");
                fmt_print("or has been removed, ");
                fmt_print("aborting surface analysis.\n");
                return (-1);
        case DISK_STAT_NOTREADY:
                fmt_print("\n\nWarning: Drive not ready, ");
                fmt_print("aborting surface analysis.\n");
                return (-1);
        case DISK_STAT_DATA_PROTECT:
                fmt_print("\n\nWarning: Drive is write protected, ");
                fmt_print("aborting surface analysis.\n");
                return (-1);
        default:
                break;
        }
        return (0);
}