Subversion Repositories freemyipod

/***************************************************************************

 *             __________               __   ___.

 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___

 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /

 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <

 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \

 *                     \/            \/     \/    \/            \/

 * $Id: dir.c 13741 2007-06-30 02:08:27Z jethead71 $

 *

 * Copyright (C) 2002 by Björn Stenberg

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 *

 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY

 * KIND, either express or implied.

 *

 ****************************************************************************/

#include "global.h"

#include <stdio.h>

#include <errno.h>

#include <string.h>

#include <stdlib.h>

#include "fat.h"

#include "dir.h"

#include "debug.h"

#ifndef MAX_OPEN_DIRS

#define MAX_OPEN_DIRS 16

#endif

extern struct scheduler_thread* current_thread;

static DIR opendirs[MAX_OPEN_DIRS];

#ifdef HAVE_HOTSWAP

// release all dir handles on a given volume "by force", to avoid leaks

int release_dirs(int volume)

{

    DIR* pdir = opendirs;

    int dd;

    int closed = 0;

    for ( dd=0; dd<MAX_OPEN_DIRS; dd++, pdir++)

    {

#ifdef HAVE_MULTIVOLUME

        if (pdir->fatdir.file.volume == volume)

#else

        (void)volume;

#endif

        {

            pdir->busy = false; /* mark as available, no further action */

            closed++;

        }

    }

    return closed; /* return how many we did */

}

#endif /* #ifdef HAVE_HOTSWAP */

DIR* opendir(const char* name)

{

    char namecopy[MAX_PATH];

    char* part;

    char* end;

    struct fat_direntry entry;

    int dd;

    DIR* pdir = opendirs;

#ifdef HAVE_MULTIVOLUME

    int volume;

#endif

    if ( name[0] != '/' ) {

        DEBUGF("Only absolute paths supported right now");

        return NULL;

    }

    /* find a free dir descriptor */

    for ( dd=0; dd<MAX_OPEN_DIRS; dd++, pdir++)

        if ( !pdir->busy )

            break;

    if ( dd == MAX_OPEN_DIRS ) {

        DEBUGF("Too many dirs open");

        errno = EMFILE;

        return NULL;

    }

    pdir->busy = true;

    pdir->process = current_thread;

#ifdef HAVE_MULTIVOLUME

    /* try to extract a heading volume name, if present */

    volume = strip_volume(name, namecopy);

    pdir->volumecounter = 0;

#else

    strlcpy(namecopy, name, sizeof(namecopy)); /* just copy */

#endif

    if ( fat_opendir(IF_MV2(volume,) &pdir->fatdir, 0, NULL) < 0 ) {

        DEBUGF("Failed opening root dir");

        pdir->busy = false;

        return NULL;

    }

    for ( part = strtok_r(namecopy, "/", &end); part;

          part = strtok_r(NULL, "/", &end)) {

        /* scan dir for name */

        while (1) {

            if ((fat_getnext(&pdir->fatdir,&entry) < 0) ||

                (!entry.name[0])) {

                pdir->busy = false;

                return NULL;

            }

            if ( (entry.attr & FAT_ATTR_DIRECTORY) &&

                 (!strcasecmp(part, entry.name)) ) {

                /* In reality, the parent_dir parameter of fat_opendir seems

                 * useless because it's sole purpose it to have a way to

                 * update the file metadata, but here we are only reading

                 * a directory so there's no need for that kind of stuff.

                 * However, the rmdir function uses a ugly hack to

                 * avoid opening a directory twice when deleting it and thus

                 * needs those information. That's why we pass pdir->fatdir both

                 * as the parent directory and the resulting one (this is safe,

                 * in doubt, check fat_open(dir) code) which will allow this kind of

                 * (ugly) things */

                if ( fat_opendir(IF_MV2(volume,)

                                 &pdir->fatdir,

                                 entry.firstcluster,

                                 &pdir->fatdir) < 0 ) {

                    DEBUGF("Failed opening dir '%s' (%ld)",

                           part, entry.firstcluster);

                    pdir->busy = false;

                    return NULL;

                }

#ifdef HAVE_MULTIVOLUME

                pdir->volumecounter = -1; /* n.a. to subdirs */

#endif

                break;

            }

        }

    }

    return pdir;

}

int closedir(DIR* dir)

{

    dir->busy=false;

    return 0;

}

int closedir_all_of_process(struct scheduler_thread* process)

{

    DIR* pdir = opendirs;

    int dd;

    int closed = 0;

    for ( dd=0; dd<MAX_OPEN_DIRS; dd++, pdir++)

    {

        if (pdir->process == process)

        {

            pdir->busy = false; /* mark as available, no further action */

            closed++;

        }

    }

    return closed; /* return how many we did */

}

struct dirent* readdir(DIR* dir)

{

    struct fat_direntry entry;

    struct dirent* theent = &(dir->theent);

    if (!dir->busy)

        return NULL;

#ifdef HAVE_MULTIVOLUME

    /* Volumes (secondary file systems) get inserted into the root directory

        of the first volume, since we have no separate top level. */

    if (dir->volumecounter >= 0 /* on a root dir */

     && dir->volumecounter < NUM_VOLUMES /* in range */

     && dir->fatdir.file.volume == 0) /* at volume 0 */

    {   /* fake special directories, which don't really exist, but

           will get redirected upon opendir() */

        while (++dir->volumecounter < NUM_VOLUMES)

        {

            if (fat_ismounted(dir->volumecounter))

            {

                memset(theent, 0, sizeof(*theent));

                theent->attribute = FAT_ATTR_DIRECTORY | FAT_ATTR_VOLUME;

                snprintf(theent->d_name, sizeof(theent->d_name), 

                         VOL_NAMES, dir->volumecounter);

                return theent;

            }

        }

    }

#endif

    /* normal directory entry fetching follows here */

    if (fat_getnext(&(dir->fatdir),&entry) < 0)

        return NULL;

    if ( !entry.name[0] )

        return NULL;

    strlcpy(theent->d_name, entry.name, sizeof(theent->d_name));

    theent->attribute = entry.attr;

    theent->size = entry.filesize;

    theent->startcluster = entry.firstcluster;

    theent->wrtdate = entry.wrtdate;

    theent->wrttime = entry.wrttime;

    return theent;

}

int mkdir(const char *name)

{

    DIR *dir;

    char namecopy[MAX_PATH];

    char* end;

    char *basename;

    char *parent;

    struct dirent *entry;

    struct fat_dir newdir;

    int rc;

    if ( name[0] != '/' ) {

        DEBUGF("mkdir: Only absolute paths supported right now");

        return -1;

    }

    strlcpy(namecopy, name, sizeof(namecopy));

    /* Split the base name and the path */

    end = strrchr(namecopy, '/');

    *end = 0;

    basename = end+1;

    if(namecopy == end) /* Root dir? */

        parent = "/";

    else

        parent = namecopy;

    DEBUGF("mkdir: parent: %s, name: %s", parent, basename);

    dir = opendir(parent);

    if(!dir) {

        DEBUGF("mkdir: can't open parent dir");

        return -2;

    }    

    if(basename[0] == 0) {

        DEBUGF("mkdir: Empty dir name");

        errno = EINVAL;

        return -3;

    }

    /* Now check if the name already exists */

    while ((entry = readdir(dir))) {

        if ( !strcasecmp(basename, entry->d_name) ) {

            DEBUGF("mkdir error: file exists");

            errno = EEXIST;

            closedir(dir);

            return - 4;

        }

    }

    memset(&newdir, 0, sizeof(struct fat_dir));

    rc = fat_create_dir(basename, &newdir, &(dir->fatdir));

    closedir(dir);

    return rc;

}

int rmdir(const char* name)

{

    int rc;

    DIR* dir;

    struct dirent* entry;

    dir = opendir(name);

    if (!dir)

    {

        errno = ENOENT; /* open error */

        return -1;

    }

    /* check if the directory is empty */

    while ((entry = readdir(dir)))

    {

        if (strcmp(entry->d_name, ".") &&

            strcmp(entry->d_name, ".."))

        {

            DEBUGF("rmdir error: not empty");

            errno = ENOTEMPTY;

            closedir(dir);

            return -2;

        }

    }

    rc = fat_remove(&(dir->fatdir.file));

    if ( rc < 0 ) {

        DEBUGF("Failed removing dir: %d", rc);

        errno = EIO;

        rc = rc * 10 - 3;

    }

    closedir(dir);

    return rc;

}

#ifdef HAVE_MULTIVOLUME

/* returns on which volume this is, and copies the reduced name

   (sortof a preprocessor for volume-decorated pathnames) */

int strip_volume(const char* name, char* namecopy)

{

    int volume = 0;

    const char *temp = name;

    while (*temp == '/')          /* skip all leading slashes */

        ++temp;

    if (*temp && !strncmp(temp, VOL_NAMES, VOL_ENUM_POS))

    {

        temp += VOL_ENUM_POS;     /* behind special name */

        volume = atoi(temp);      /* number is following */

        temp = strchr(temp, '/'); /* search for slash behind */

        if (temp != NULL)

            name = temp;          /* use the part behind the volume */

        else

            name = "/";           /* else this must be the root dir */

    }

    strlcpy(namecopy, name, MAX_PATH);

    return volume;

}

#endif /* #ifdef HAVE_MULTIVOLUME */