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//==========================================================================

//

//      testfs.c

//

//      Test file system

//

//==========================================================================

//####ECOSGPLCOPYRIGHTBEGIN####

// -------------------------------------------

// This file is part of eCos, the Embedded Configurable Operating System.

// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.

//

// eCos 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 or (at your option) any later version.

//

// eCos is distributed in the hope that it will be useful, but WITHOUT ANY

// WARRANTY; without even the implied warranty of MERCHANTABILITY or

// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

// for more details.

//

// You should have received a copy of the GNU General Public License along

// with eCos; if not, write to the Free Software Foundation, Inc.,

// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

//

// As a special exception, if other files instantiate templates or use macros

// or inline functions from this file, or you compile this file and link it

// with other works to produce a work based on this file, this file does not

// by itself cause the resulting work to be covered by the GNU General Public

// License. However the source code for this file must still be made available

// in accordance with section (3) of the GNU General Public License.

//

// This exception does not invalidate any other reasons why a work based on

// this file might be covered by the GNU General Public License.

//

// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.

// at http://sources.redhat.com/ecos/ecos-license/

// -------------------------------------------

//####ECOSGPLCOPYRIGHTEND####

//==========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):           nickg

// Contributors:        nickg

// Date:                2000-05-25

// Purpose:             Test file system

// Description:         This is a very simple implementation of a RAM file system.

//                      This implementation is not "industrial strength" or suitable

//                      for production use, it is too wasteful of both memory and time.

//                      Its primary purpose is to support testing of the fileio

//                      infrastructure and API. It can, however, serve as a model

//                      and source of code fragments for the implementation

//                      of further filesystems.

//              

//

//####DESCRIPTIONEND####

//

//==========================================================================

#include <pkgconf/hal.h>

#include <pkgconf/kernel.h>

#include <pkgconf/io_fileio.h>

#include <cyg/kernel/ktypes.h>         // base kernel types

#include <cyg/infra/cyg_trac.h>        // tracing macros

#include <cyg/infra/cyg_ass.h>         // assertion macros

#include <unistd.h>

#include <fcntl.h>

#include <sys/stat.h>

#include <errno.h>

#include <dirent.h>

#include <cyg/fileio/fileio.h>

#include <cyg/kernel/kapi.h>

#include <cyg/infra/diag.h>

//==========================================================================

// Configuration  parameters

#define TESTFS_NFILE            10      // Max number of files/directories

#define TESTFS_NBLOCK           20      // Number of data blocks available

#define TESTFS_BLOCKSIZE        128     // Bytes stored per block

#define TESTFS_FILEBLOCKS       8       // Max blocks per file

#define TESTFS_NAMESIZE         32      // Length of file names in bytes

// Maximum file size is blocksize*blocks

#define TESTFS_FILESIZE_MAX     (TESTFS_BLOCKSIZE*TESTFS_FILEBLOCKS)

//==========================================================================

// Data structures

struct testfs_node;

typedef struct testfs_node testfs_node;

struct testfs_block;

typedef struct testfs_block testfs_block;

struct testfs_node

{

    testfs_node         *next;          // next node in list

    testfs_node         *parent;        // Back pointer to parent

    int                 refcnt;         // reference count

    char                name[TESTFS_NAMESIZE]; // file name

    struct stat         status;         // status data

    union

    {

        struct

        {

            testfs_block        *data[TESTFS_FILEBLOCKS];  // array of blocks

        } file;

        struct

        {

            testfs_node         *nodes[TESTFS_FILEBLOCKS]; // array of nodes

        } dir;

    } u;

};

struct testfs_block

{

    union

    {

        testfs_block    *next;          // next block in free list

        testfs_node     *file;          // back pointer to file

    } u;

    off_t               pos;            // position in file of first byte

    size_t              size;           // number of bytes in buffer

    char                data[TESTFS_BLOCKSIZE]; // the data

};

//==========================================================================

// Local data

// Array of nodes

static testfs_node node[TESTFS_NFILE];

// node free list.

static testfs_node *free_node = NULL;

// Array of data blocks

static testfs_block block[TESTFS_NBLOCK];

// block free list.

static testfs_block *free_block = NULL;

// Init flag

cyg_bool testfs_initialized = false;

//==========================================================================

// Forward definitions

// Filesystem operations

static int testfs_mount    ( cyg_fstab_entry *fste, cyg_mtab_entry *mte );

static int testfs_umount   ( cyg_mtab_entry *mte );

static int testfs_open     ( cyg_mtab_entry *mte, cyg_dir dir, const char *name,

                             int mode,  cyg_file *fte );

static int testfs_unlink   ( cyg_mtab_entry *mte, cyg_dir dir, const char *name );

static int testfs_mkdir    ( cyg_mtab_entry *mte, cyg_dir dir, const char *name );

static int testfs_rmdir    ( cyg_mtab_entry *mte, cyg_dir dir, const char *name );

static int testfs_rename   ( cyg_mtab_entry *mte, cyg_dir dir1, const char *name1,

                             cyg_dir dir2, const char *name2 );

static int testfs_link     ( cyg_mtab_entry *mte, cyg_dir dir1, const char *name1,

                             cyg_dir dir2, const char *name2, int type );

static int testfs_opendir  ( cyg_mtab_entry *mte, cyg_dir dir, const char *name,

                             cyg_file *fte );

static int testfs_chdir    ( cyg_mtab_entry *mte, cyg_dir dir, const char *name,

                             cyg_dir *dir_out );

static int testfs_stat     ( cyg_mtab_entry *mte, cyg_dir dir, const char *name,

                             struct stat *buf);

static int testfs_getinfo  ( cyg_mtab_entry *mte, cyg_dir dir, const char *name,

                             int key, void *buf, int len );

static int testfs_setinfo  ( cyg_mtab_entry *mte, cyg_dir dir, const char *name,

                             int key, void *buf, int len );

// File operations

static int testfs_fo_read      (struct CYG_FILE_TAG *fp, struct CYG_UIO_TAG *uio);

static int testfs_fo_write     (struct CYG_FILE_TAG *fp, struct CYG_UIO_TAG *uio);

static int testfs_fo_lseek     (struct CYG_FILE_TAG *fp, off_t *pos, int whence );

static int testfs_fo_ioctl     (struct CYG_FILE_TAG *fp, CYG_ADDRWORD com,

                                CYG_ADDRWORD data);

//static int testfs_fo_select    (struct CYG_FILE_TAG *fp, int which, CYG_ADDRWORD info);

static int testfs_fo_fsync     (struct CYG_FILE_TAG *fp, int mode );

static int testfs_fo_close     (struct CYG_FILE_TAG *fp);

static int testfs_fo_fstat     (struct CYG_FILE_TAG *fp, struct stat *buf );

static int testfs_fo_getinfo   (struct CYG_FILE_TAG *fp, int key, void *buf, int len );

static int testfs_fo_setinfo   (struct CYG_FILE_TAG *fp, int key, void *buf, int len );

// Directory operations

static int testfs_fo_dirread      (struct CYG_FILE_TAG *fp, struct CYG_UIO_TAG *uio);

static int testfs_fo_dirlseek     (struct CYG_FILE_TAG *fp, off_t *pos, int whence );

//==========================================================================

// Filesystem table entries

FSTAB_ENTRY( testfs_fste, "testfs", 0,

             CYG_SYNCMODE_FILE_FILESYSTEM|CYG_SYNCMODE_IO_FILESYSTEM,

             testfs_mount,

             testfs_umount,

             testfs_open,

             testfs_unlink,

             testfs_mkdir,

             testfs_rmdir,

             testfs_rename,

             testfs_link,

             testfs_opendir,

             testfs_chdir,

             testfs_stat,

             testfs_getinfo,

             testfs_setinfo);

MTAB_ENTRY( testfs_mte1,

                   "/",

                   "testfs",

                   "",

                   0);

#if 0

MTAB_ENTRY( testfs_mte2,

                   "/ram",

                   "testfs",

                   "",

                   0);

#endif

static cyg_fileops testfs_fileops =

{

    testfs_fo_read,

    testfs_fo_write,

    testfs_fo_lseek,

    testfs_fo_ioctl,

    cyg_fileio_seltrue,

    testfs_fo_fsync,

    testfs_fo_close,

    testfs_fo_fstat,

    testfs_fo_getinfo,

    testfs_fo_setinfo

};

static cyg_fileops testfs_dirops =

{

    testfs_fo_dirread,

    (cyg_fileop_write *)cyg_fileio_enosys,

    testfs_fo_dirlseek,

    (cyg_fileop_ioctl *)cyg_fileio_enosys,

    cyg_fileio_seltrue,

    (cyg_fileop_fsync *)cyg_fileio_enosys,

    testfs_fo_close,

    (cyg_fileop_fstat *)cyg_fileio_enosys,

    (cyg_fileop_getinfo *)cyg_fileio_enosys,

    (cyg_fileop_setinfo *)cyg_fileio_enosys

};

//==========================================================================

// Support routines

// -------------------------------------------------------------------------

// Local strcmp() and strcpy()

static int strcmp( const char *s1, const char *s2 )

{

    while( *s1 == *s2 && *s1 != '\0' && *s2 != '\0' )

        s1++, s2++;

    return (*s2)-(*s1);

}

static char *strcpy( char *s1, const char *s2 )

{

    char *s = s1;

    while( (*s1++ = *s2++) != 0);

    return s;

}

// -------------------------------------------------------------------------

// Follow a path through the directory structure

static int testfs_find( testfs_node *dir,       // dir to start search in

                        const char *path,       // path to follow

                        testfs_node **found,    // return node found

                        testfs_node **parent,   // return last dir searched

                        char *name,             // name fragment buffer

                        cyg_bool *lastp)        // last name in path ?

{

    testfs_node *nd = dir;

    *lastp = false;

    *found = NULL;

    while( *path != '\0' )

    {

        const char *p = path;

        char *n = name;

        testfs_node *nd1;

        int i;

        // check nd is a directory

        if( !S_ISDIR(nd->status.st_mode) ) return ENOTDIR;

        // Isolate the next element of the path name. 

        while( *p != '\0' && *p != '/' && (n-&name[0]) < TESTFS_NAMESIZE)

            *n++ = *p++;

        if( (n-&name[0]) >= TESTFS_NAMESIZE )

            return ENAMETOOLONG;

        // Step path on past the separator

        // If this is the last name element in the path,

        // set *lastp to indicate this.

        if( *(path=p) == '/' ) path++;

        else *lastp = true;

        // teminate name

        *n = '\0';

        // name now contains the next path element, search the node

        // in nd for it.

        *parent = nd;

        nd1 = NULL;

        for( i = 0; i < TESTFS_FILEBLOCKS; i++ )

        {

            testfs_node *n = nd->u.dir.nodes[i];

            if( n == NULL )

                continue;

            if( strcmp( name, n->name ) == 0 )

            {

                nd1 = n;

                break;

            }

        }

        if( nd1 == NULL ) return ENOENT;

        nd = nd1;

    }

    // Return what we have found

    *found = nd;

    return ENOERR;

}

// -------------------------------------------------------------------------

// Get current time since epoch

static time_t testfs_time(void)

{

    // FIXME: !!!!Temporary!!!!

    return cyg_current_time();

}

// -------------------------------------------------------------------------

static int testfs_delnode( testfs_node *nd )

{

    testfs_node *parent;

    int i;

    // Non-unitary ref count means this node is either open    

    // or is a dir with entries in it.

    if( nd->refcnt > 1 )

        return EBUSY;

    // Remove from parent's node list.

    parent = nd->parent;

    for( i = 0; i < TESTFS_FILEBLOCKS; i++ )

        if( parent->u.dir.nodes[i] == nd )

        {

            parent->u.dir.nodes[i] = NULL;

            break;

        }

    parent->refcnt--;

    if( S_ISREG(nd->status.st_mode) )

    {

        // for a file, return blocks to free list

        for( i = 0; i < TESTFS_FILEBLOCKS; i++ )

        {

            testfs_block *b = nd->u.file.data[i];

            if( b != NULL )

            {

                b->u.next = free_block;

                b->pos = -1;

                free_block = b;

            }

        }

    }

    // and finally return nd to free node list

    nd->next = free_node;

    nd->refcnt = -1;

    free_node = nd;

    return ENOERR;

}

//==========================================================================

// Filesystem operations

// -------------------------------------------------------------------------

static int testfs_mount    ( cyg_fstab_entry *fste, cyg_mtab_entry *mte )

{

    testfs_node *root;

    int i;

    if( !testfs_initialized )

    {

        int i;

        for( i = 0; i < TESTFS_NFILE; i++ )

        {

            node[i].next = free_node;

            node[i].refcnt = -1;

            free_node = &node[i];

        }

        for( i = 0; i < TESTFS_NBLOCK; i++ )

        {

            block[i].u.next = free_block;

            block[i].pos = -1;

            free_block = &block[i];

        }

        testfs_initialized = true;

    }

    // Allocate a node to be the root of this filesystem and

    // initialize it.

    root = free_node;

    if( root == NULL ) return ENOSPC;

    free_node = root->next;

    root->next                  = root;  // form circular list

    root->parent                = root;  // I'm my own parent!

    root->refcnt                = 1;     // don't want to ever lose root

    strcpy( root->name, "root");

    root->status.st_mode        = __stat_mode_DIR;

    root->status.st_ino         = root-&node[0];

    root->status.st_dev         = 0;

    root->status.st_nlink       = 1;

    root->status.st_uid         = 0;

    root->status.st_gid         = 0;

    root->status.st_size        = 0;

    root->status.st_atime       = testfs_time();

    root->status.st_mtime       = testfs_time();

    root->status.st_ctime       = testfs_time();

    for( i = 0; i < TESTFS_FILEBLOCKS; i++ )

        root->u.dir.nodes[i]    = NULL;

    mte->root = (cyg_dir)root;

    return 0;

}

// -------------------------------------------------------------------------

static int testfs_umount    ( cyg_mtab_entry *mte )

{

    testfs_node *root = (testfs_node *)mte->root;

    // Non-empty filesystem, do not unmount

    if( root->refcnt != 1 )

        return EBUSY;

    // Otherwise just return it to the free pool

    root->next = free_node;

    root->refcnt = -1;

    free_node = root;

    // Clear root pointer

    mte->root = CYG_DIR_NULL;

    // That's all folks.

    return ENOERR;

}

// -------------------------------------------------------------------------

static int testfs_open     ( cyg_mtab_entry *mte, cyg_dir dir, const char *path,

                          int mode,  cyg_file *file )

{

    testfs_node *nd, *parent;

    int err;

    char name[TESTFS_NAMESIZE];

    cyg_bool lastp;

    err = testfs_find( (testfs_node *)dir, path, &nd, &parent, name, &lastp );

    if( lastp && err == ENOENT && (mode & O_CREAT) )

    {

        int i;

        // No node there, if the O_CREAT bit is set then we must

        // create a new one. The parent and name results will have been filled

        // in, so we know where to put it.

        // first check that there is space for it

        for( i = 0; i < TESTFS_FILEBLOCKS; i++ )

            if( parent->u.dir.nodes[i] == NULL )

                break;

        if( i == TESTFS_FILEBLOCKS ) return ENOSPC;

        // Allocate a new node

        nd = free_node;

        if( nd == NULL ) return ENOSPC;

        free_node = nd->next;

        // Add to directory list

        parent->u.dir.nodes[i] = nd;

        parent->refcnt++;

        // Fill in details

        nd->parent              = parent;

        nd->refcnt              = 1;    // 1 for directory reference

        strcpy( nd->name, name);

        nd->status.st_mode      = __stat_mode_REG;

        nd->status.st_ino       = nd-&node[0];

        nd->status.st_dev       = 0;

        nd->status.st_nlink     = 1;

        nd->status.st_uid       = 0;

        nd->status.st_gid       = 0;

        nd->status.st_size      = 0;

        nd->status.st_atime     = testfs_time();

        nd->status.st_mtime     = testfs_time();

        nd->status.st_ctime     = testfs_time();

        for( i = 0; i < TESTFS_FILEBLOCKS; i++ )

            nd->u.file.data[i]  = NULL;

        err = ENOERR;

    }

    if( err == ENOERR && (mode & O_TRUNC ) )

    {

        // Clean out any blocks in the file...

        int i;

        for( i = 0; i < TESTFS_FILEBLOCKS; i++ )

        {

            testfs_block *b = nd->u.file.data[i];

            if( b != NULL )

            {

                b->u.next = free_block;

                b->pos = -1;

                free_block = b;

                nd->u.file.data[i] = NULL;

            }

        }

        nd->status.st_size = 0;

    }

    if( err != ENOERR ) return err;

    if( S_ISDIR(nd->status.st_mode) ) return EISDIR;

    nd->refcnt++;       // Count successful open as a ref

    // Initialize the file object

    file->f_flag        |= mode & CYG_FILE_MODE_MASK;

    file->f_type        = CYG_FILE_TYPE_FILE;

    file->f_ops         = &testfs_fileops;

    file->f_offset      = 0;

    file->f_data        = (CYG_ADDRWORD)nd;

    file->f_xops        = 0;

    return ENOERR;

}

// -------------------------------------------------------------------------

static int testfs_unlink   ( cyg_mtab_entry *mte, cyg_dir dir, const char *path )

{

    testfs_node *nd, *parent;

    int err;

    char name[TESTFS_NAMESIZE];

    cyg_bool lastp;

    err = testfs_find( (testfs_node *)dir, path, &nd, &parent, name, &lastp );

    if( err != ENOERR ) return err;

    // Cannot unlink directories, use rmdir() instead

    if( S_ISDIR(nd->status.st_mode) )

        return EPERM;

    err = testfs_delnode( nd );

    return err;

}

// -------------------------------------------------------------------------

static int testfs_mkdir    ( cyg_mtab_entry *mte, cyg_dir dir, const char *path )

{

    testfs_node *nd, *parent;

    int err;

    char name[TESTFS_NAMESIZE];

    cyg_bool lastp;

    err = testfs_find( (testfs_node *)dir, path, &nd, &parent, name, &lastp );

    if( lastp && err == ENOENT )

    {

        int i;

        // No node there, create a new one. The parent and name

        // results will have been filled in, so we know where to put

        // it.

        // first check that there is space for it

        for( i = 0; i < TESTFS_FILEBLOCKS; i++ )

            if( parent->u.dir.nodes[i] == NULL )

                break;

        if( i == TESTFS_FILEBLOCKS ) return ENOSPC;

        // Allocate a new node

        nd = free_node;

        if( nd == NULL ) return ENOSPC;

        free_node = nd->next;

        // Add to directory list

        parent->u.dir.nodes[i] = nd;

        parent->refcnt++;

        // Fill in details

        nd->parent              = parent;

        nd->refcnt              = 1;    // 1 for directory reference

        strcpy( nd->name, name);

        nd->status.st_mode      = __stat_mode_DIR;

        nd->status.st_ino       = nd-&node[0];

        nd->status.st_dev       = 0;

        nd->status.st_nlink     = 1;

        nd->status.st_uid       = 0;

        nd->status.st_gid       = 0;

        nd->status.st_size      = 0;

        nd->status.st_atime     = testfs_time();

        nd->status.st_mtime     = testfs_time();

        nd->status.st_ctime     = testfs_time();

        for( i = 0; i < TESTFS_FILEBLOCKS; i++ )

            nd->u.dir.nodes[i]  = NULL;

        err = ENOERR;

    }

    return err;

}

// -------------------------------------------------------------------------

static int testfs_rmdir    ( cyg_mtab_entry *mte, cyg_dir dir, const char *path )

{

    testfs_node *nd, *parent;

    int err;

    char name[TESTFS_NAMESIZE];

    cyg_bool lastp;

    err = testfs_find( (testfs_node *)dir, path, &nd, &parent, name, &lastp );