common/string/fmtfs.c

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1985-2010 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                  Common Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*            http://www.opensource.org/licenses/cpl1.0.txt             *
*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                  David Korn <dgk@research.att.com>                   *
*                   Phong Vo <kpv@research.att.com>                    *
*                                                                      *
***********************************************************************/
#pragma prototyped

/*
 * Glenn Fowler
 * AT&T Bell Laboratories
 *
 * return fs type string given stat
 */

#include <ast.h>
#include <ls.h>
#include <mnt.h>

#include "FEATURE/fs"

#if _str_st_fstype

char*
fmtfs(struct stat* st)
{
    return st->st_fstype;
}

#else

#include <cdt.h>

typedef struct Id_s
{
    Dtlink_t    link;
    dev_t       id;
    char        name[1];
} Id_t;

char*
fmtfs(struct stat* st)
{
    register Id_t*      ip;
    register void*      mp;
    register Mnt_t*     mnt;
    register char*      s;
    struct stat     rt;
    char*           buf;

    static Dt_t*        dict;
    static Dtdisc_t     disc;

    if (!dict)
    {
        disc.key = offsetof(Id_t, id);
        disc.size = sizeof(dev_t);
        dict = dtopen(&disc, Dthash);
    }
    else if (ip = (Id_t*)dtmatch(dict, &st->st_dev))
        return ip->name;
    s = FS_default;
    if (mp = mntopen(NiL, "r"))
    {
        while ((mnt = mntread(mp)) && (stat(mnt->dir, &rt) || rt.st_dev != st->st_dev));
        if (mnt && mnt->type)
            s = mnt->type;
    }
    if (!dict || !(ip = newof(0, Id_t, 1, strlen(s))))
    {
        if (!mp)
            return s;
        buf = fmtbuf(strlen(s) + 1);
        strcpy(buf, s);
        mntclose(mp);
        return buf;
    }
    strcpy(ip->name, s);
    if (mp)
        mntclose(mp);
    dtinsert(dict, ip);
    return ip->name;
}

#endif