/*
 * 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
 */
/*
 * Miscellaneous support subroutines for High Sierra filesystem
 *
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/cmn_err.h>
#include <sys/systm.h>
#include <sys/sysmacros.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/user.h>
#include <sys/vfs.h>
#include <sys/vnode.h>
#include <sys/proc.h>
#include <sys/debug.h>
#include <sys/kmem.h>
#include <sys/uio.h>
#include <vm/hat.h>
#include <vm/as.h>
#include <vm/seg.h>
#include <vm/page.h>
#include <vm/pvn.h>
#include <vm/seg_map.h>
#include <sys/swap.h>
#include <vm/seg_kmem.h>

#include <sys/fs/hsfs_spec.h>
#include <sys/fs/hsfs_node.h>
#include <sys/fs/hsfs_impl.h>

#define THE_EPOCH       1970
#define END_OF_TIME     2099
extern int hsfs_lostpage;

#ifdef __STDC__
static time_t hs_date_to_gmtime(int year, int mon, int day, int gmtoff);
#else
static time_t hs_date_to_gmtime();
#endif

/*
 * Table used in logging non-fatal errors which should be recorded
 * once per mount.  Indexed by HSFS_ERR values (defined in hsfs_node.h).
 */
struct hsfs_error {
        char    *hdr_text;      /* msg prefix: general error type */
                                /* must contain %s for mnt pt */
        char    *err_text;      /* specific error message */
        uchar_t multiple;       /* > 1 such error per fs possible? */
        uchar_t n_printf_args;  /* if err_text printf-like, # addtl args */
} hsfs_error[] = {
        /* HSFS_ERR_TRAILING_JUNK */
        "hsfs: Warning: the file system mounted on %s "
                "does not conform to the ISO-9660 specification:",
        "trailing blanks or null characters in file or directory name.\n",
        1, 0,
        /* HSFS_ERR_LOWER_CASE_NM */
        "hsfs: Warning: the file system mounted on %s "
                "does not conform to the ISO-9660 specification:",
        "lower case characters in file or directory name.\n",
        1, 0,
        /* HSFS_ERR_BAD_ROOT_DIR */
        "hsfs: Warning: the file system mounted on %s "
                "does not conform to the ISO-9660 specification:",
        "invalid root directory.\n",
        0,  0,
        /* HSFS_ERR_UNSUP_TYPE */
        "hsfs: Warning: the file system mounted on %s "
                "contains a file or directory with an unsupported type:",
        " 0x%x.\n",
        1, 1,
        /* HSFS_ERR_BAD_FILE_LEN */
        "hsfs: Warning: file system mounted on %s "
                "does not conform to the ISO-9660 specification:",
        "file name length greater than max allowed\n",
        1, 0,
        /* HSFS_ERR_BAD_JOLIET_FILE_LEN */
        "hsfs: Warning: file system mounted on %s "
                "does not conform to the Joliet specification:",
        "file name length greater than max allowed\n",
        1, 0,
        /* HSFS_ERR_TRUNC_JOLIET_FILE_LEN */
        "hsfs: Warning: file system mounted on %s "
                "does not conform to the Joliet specification:",
        "file name length greater than MAXNAMELEN (truncated)\n",
        1, 0,
        /* HSFS_ERR_BAD_DIR_ENTRY */
        "hsfs: Warning: file system mounted on %s "
                "has inconsistent data:",
        "invalid directory or file name length (ignored)\n",
        1, 0,
        /* HSFS_ERR_NEG_SUA_LEN */
        "hsfs: Warning: file system mounted on %s "
                "has inconsistent Rock Ridge data:",
        "negative SUA len\n",
        1, 0,
        /* HSFS_ERR_BAD_SUA_LEN */
        "hsfs: Warning: file system mounted on %s "
                "has inconsistent Rock Ridge data:",
        "SUA len too big\n",
        1, 0,
};

/*
 * Local datatype for defining tables of (Offset, Name) pairs for
 * kstats.
 */
typedef struct {
        offset_t        index;
        char            *name;
} hsfs_ksindex_t;

static const hsfs_ksindex_t hsfs_kstats[] = {
        { 0,            "mountpoint"            },
        { 1,            "pages_lost"            },
        { 2,            "physical_read_pages"   },
        { 3,            "cache_read_pages"      },
        { 4,            "readahead_pages"       },
        { 5,            "coalesced_pages"       },
        { 6,            "total_pages_requested" },
        {-1,            NULL                    }
};

/*
 * hs_parse_dirdate
 *
 * Parse the short 'directory-format' date into a Unix timeval.
 * This is the date format used in Directory Entries.
 *
 * If the date is not representable, make something up.
 */
void
hs_parse_dirdate(dp, tvp)
        uchar_t *dp;
        struct timeval *tvp;
{
        int year, month, day, hour, minute, sec, gmtoff;

        year = HDE_DATE_YEAR(dp);
        month = HDE_DATE_MONTH(dp);
        day = HDE_DATE_DAY(dp);
        hour = HDE_DATE_HOUR(dp);
        minute = HDE_DATE_MIN(dp);
        sec = HDE_DATE_SEC(dp);
        gmtoff = HDE_DATE_GMTOFF(dp);

        tvp->tv_usec = 0;
        if (year < THE_EPOCH) {
                tvp->tv_sec = 0;
        } else {
                tvp->tv_sec = hs_date_to_gmtime(year, month, day, gmtoff);
                if (tvp->tv_sec != -1) {
                        tvp->tv_sec += ((hour * 60) + minute) * 60 + sec;
                }
        }

        return;

}

/*
 * hs_parse_longdate
 *
 * Parse the long 'user-oriented' date into a Unix timeval.
 * This is the date format used in the Volume Descriptor.
 *
 * If the date is not representable, make something up.
 */
void
hs_parse_longdate(dp, tvp)
        uchar_t *dp;
        struct timeval *tvp;
{
        int year, month, day, hour, minute, sec, gmtoff;

        year = HSV_DATE_YEAR(dp);
        month = HSV_DATE_MONTH(dp);
        day = HSV_DATE_DAY(dp);
        hour = HSV_DATE_HOUR(dp);
        minute = HSV_DATE_MIN(dp);
        sec = HSV_DATE_SEC(dp);
        gmtoff = HSV_DATE_GMTOFF(dp);

        tvp->tv_usec = 0;
        if (year < THE_EPOCH) {
                tvp->tv_sec = 0;
        } else {
                tvp->tv_sec = hs_date_to_gmtime(year, month, day, gmtoff);
                if (tvp->tv_sec != -1) {
                        tvp->tv_sec += ((hour * 60) + minute) * 60 + sec;
                        tvp->tv_usec = HSV_DATE_HSEC(dp) * 10000;
                }
        }

}

/* cumulative number of seconds per month,  non-leap and leap-year versions */
static time_t cum_sec[] = {
        0x0, 0x28de80, 0x4dc880, 0x76a700, 0x9e3400, 0xc71280,
        0xee9f80, 0x1177e00, 0x1405c80, 0x167e980, 0x190c800, 0x1b85500
};
static time_t cum_sec_leap[] = {
        0x0, 0x28de80, 0x4f1a00, 0x77f880, 0x9f8580, 0xc86400,
        0xeff100, 0x118cf80, 0x141ae00, 0x1693b00, 0x1921980, 0x1b9a680
};
#define SEC_PER_DAY     0x15180
#define SEC_PER_YEAR    0x1e13380

/*
 * hs_date_to_gmtime
 *
 * Convert year(1970-2099)/month(1-12)/day(1-31) to seconds-since-1970/1/1.
 *
 * Returns -1 if the date is out of range.
 */
static time_t
hs_date_to_gmtime(year, mon, day, gmtoff)
        int year;
        int mon;
        int day;
        int gmtoff;
{
        time_t sum;
        time_t *cp;
        int y;

        if ((year < THE_EPOCH) || (year > END_OF_TIME) ||
            (mon < 1) || (mon > 12) ||
            (day < 1) || (day > 31))
                return (-1);

        /*
         * Figure seconds until this year and correct for leap years.
         * Note: 2000 is a leap year but not 2100.
         */
        y = year - THE_EPOCH;
        sum = y * SEC_PER_YEAR;
        sum += ((y + 1) / 4) * SEC_PER_DAY;
        /*
         * Point to the correct table for this year and
         * add in seconds until this month.
         */
        cp = ((y + 2) % 4) ? cum_sec : cum_sec_leap;
        sum += cp[mon - 1];
        /*
         * Add in seconds until 0:00 of this day.
         * (days-per-month validation is not done here)
         */
        sum += (day - 1) * SEC_PER_DAY;
        sum -= (gmtoff * 15 * 60);
        return (sum);
}

/*
 * Indicate whether the directory is valid.
 */

int
hsfs_valid_dir(hd)
        struct hs_direntry *hd;
{
        /*
         * check to see if this directory is not marked as a directory.
         * check to see if data length is zero.
         */

        if (hd->ext_size == 0)
                return (0);

        if (hd->type != VDIR)
                return (0);

        return (1);
}



/*
 * If we haven't complained about this error type yet, do.
 */
void
hs_log_bogus_disk_warning(fsp, errtype, data)
        struct hsfs     *fsp;
        int             errtype;
        uint_t          data;
{

        if (fsp->hsfs_err_flags & (1 << errtype))
                return;         /* already complained */

        cmn_err(CE_NOTE, hsfs_error[errtype].hdr_text,
                fsp->hsfs_fsmnt);

        switch (hsfs_error[errtype].n_printf_args) {
        case 0:
                cmn_err(CE_CONT, hsfs_error[errtype].err_text);
                break;
        case 1:
                cmn_err(CE_CONT, hsfs_error[errtype].err_text, data);
                break;
        default:
                /* don't currently handle more than 1 arg */
                cmn_err(CE_CONT, "unknown problem; internal error.\n");
        }
        cmn_err(CE_CONT,
"Due to this error, the file system may not be correctly interpreted.\n");
        if (hsfs_error[errtype].multiple)
                cmn_err(CE_CONT,
"Other such errors in this file system will be silently ignored.\n\n");
        else
                cmn_err(CE_CONT, "\n");

        fsp->hsfs_err_flags |= (1 << errtype);
}

/*
 * Callback from kstat framework. Grab a snapshot of the current hsfs
 * counters and populate the kstats.
 */
static int
hsfs_kstats_update(kstat_t *ksp, int flag)
{
        struct hsfs *fsp;
        kstat_named_t *knp;
        uint64_t pages_lost;
        uint64_t physical_read_bytes;
        uint64_t cache_read_pages;
        uint64_t readahead_bytes;
        uint64_t coalesced_bytes;
        uint64_t total_pages_requested;

        if (flag != KSTAT_READ)
                return (EACCES);

        fsp = ksp->ks_private;
        knp = ksp->ks_data;

        mutex_enter(&(fsp->hqueue->strategy_lock));
        mutex_enter(&(fsp->hqueue->hsfs_queue_lock));

        cache_read_pages = fsp->cache_read_pages;
        pages_lost = hsfs_lostpage;
        physical_read_bytes = fsp->physical_read_bytes;
        readahead_bytes =  fsp->readahead_bytes;
        coalesced_bytes = fsp->coalesced_bytes;
        total_pages_requested = fsp->total_pages_requested;

        mutex_exit(&(fsp->hqueue->strategy_lock));
        mutex_exit(&(fsp->hqueue->hsfs_queue_lock));

        knp++;
        (knp++)->value.ui64 = pages_lost;
        (knp++)->value.ui64 = howmany(physical_read_bytes, PAGESIZE);
        (knp++)->value.ui64 = cache_read_pages;
        (knp++)->value.ui64 = howmany(readahead_bytes, PAGESIZE);
        (knp++)->value.ui64 = howmany(coalesced_bytes, PAGESIZE);
        (knp++)->value.ui64 = total_pages_requested;

        return (0);
}

/*
 * Initialize hsfs kstats, which are all name value pairs with
 * values being various counters.
 */
static kstat_t *
hsfs_setup_named_kstats(struct hsfs *fsp, int fsid, char *name,
    const hsfs_ksindex_t *ksip, int (*update)(kstat_t *, int))
{
        kstat_t *ksp;
        kstat_named_t *knp;
        char *np;
        char *mntpt = fsp->hsfs_fsmnt;
        size_t size;

        size = (sizeof (hsfs_kstats)) / (sizeof (hsfs_ksindex_t));
        ksp = kstat_create("hsfs_fs", fsid, name, "hsfs",
            KSTAT_TYPE_NAMED, size-1, KSTAT_FLAG_VIRTUAL);
        if (ksp == NULL)
                return (NULL);

        ksp->ks_data = kmem_alloc(sizeof (kstat_named_t) * size, KM_SLEEP);
        ksp->ks_private = fsp;
        ksp->ks_update = update;
        ksp->ks_data_size += strlen(mntpt) + 1;
        knp = ksp->ks_data;
        kstat_named_init(knp, ksip->name, KSTAT_DATA_STRING);
        kstat_named_setstr(knp, mntpt);
        knp++;
        ksip++;

        for (; (np = ksip->name) != NULL; ++knp, ++ksip) {
                kstat_named_init(knp, np, KSTAT_DATA_UINT64);
        }
        kstat_install(ksp);

        return (ksp);
}

void
hsfs_init_kstats(struct hsfs *fsp, int fsid)
{
        fsp->hsfs_kstats = hsfs_setup_named_kstats(fsp, fsid, "hsfs_read_stats",
            hsfs_kstats, hsfs_kstats_update);
}

void
hsfs_fini_kstats(struct hsfs *fsp)
{
        void *data;

        if (fsp->hsfs_kstats != NULL) {
                data = fsp->hsfs_kstats->ks_data;
                kstat_delete(fsp->hsfs_kstats);
                kmem_free(data, sizeof (kstat_named_t) *
                    (sizeof (hsfs_kstats)) / (sizeof (hsfs_ksindex_t)));
        }
        fsp->hsfs_kstats = NULL;
}