File: [local] / prex / usr / server / fs / arfs / arfs_vnops.c (download)
Revision 1.1.1.1 (vendor branch), Tue Aug 19 12:47:01 2008 UTC (16 years ago) by nbrk
Branch: MAIN, KOHSUKE
CVS Tags: PREX_0_8_BASE, HEAD Changes since 1.1: +0 -0 lines
Initial import of Prex, Portable Real-time Embedded POSIX microkernel system.
I have totally new directions in my development (more focused on real hardware, not virtual one).
Old hacks are available in prex-old module. They will be carefully re-designed and merged soon.
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/*
* Copyright (c) 2006-2007, Kohsuke Ohtani
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* arfs_vnops.c - vnode operations for archive file system.
*/
/**
* General design:
*
* ARFS (ARchive File System) is the read-only file system which
* handles the generic archive (*.a) file as a file system image.
* The file system is typically used for the boot time file system,
* and it's mounted to the ram disk device mapped to the pre-loaded
* archive file image. All files are placed in one single directory.
*/
#include <prex/prex.h>
#include <sys/stat.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/mount.h>
#include <sys/param.h>
#include <sys/dirent.h>
#include <sys/buf.h>
#include <ctype.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <limits.h>
#include <fcntl.h>
#include <ar.h>
#include "arfs.h"
#define arfs_open ((vnop_open_t)vop_nullop)
#define arfs_close ((vnop_close_t)vop_nullop)
static int arfs_read (vnode_t, file_t, void *, size_t, size_t *);
#define arfs_write ((vnop_write_t)vop_nullop)
static int arfs_seek (vnode_t, file_t, off_t, off_t);
#define arfs_ioctl ((vnop_ioctl_t)vop_einval)
#define arfs_fsync ((vnop_fsync_t)vop_nullop)
static int arfs_readdir (vnode_t, file_t, struct dirent *);
static int arfs_lookup (vnode_t, char *, vnode_t);
#define arfs_create ((vnop_create_t)vop_einval)
#define arfs_remove ((vnop_remove_t)vop_einval)
#define arfs_rename ((vnop_rename_t)vop_einval)
#define arfs_mkdir ((vnop_mkdir_t)vop_einval)
#define arfs_rmdir ((vnop_rmdir_t)vop_einval)
#define arfs_getattr ((vnop_getattr_t)vop_nullop)
#define arfs_setattr ((vnop_setattr_t)vop_nullop)
#define arfs_inactive ((vnop_inactive_t)vop_nullop)
#define arfs_truncate ((vnop_truncate_t)vop_nullop)
static char iobuf[BSIZE*2];
#if CONFIG_FS_THREADS > 1
static mutex_t arfs_lock = MUTEX_INITIALIZER;
#endif
/*
* vnode operations
*/
const struct vnops arfs_vnops = {
arfs_open, /* open */
arfs_close, /* close */
arfs_read, /* read */
arfs_write, /* write */
arfs_seek, /* seek */
arfs_ioctl, /* ioctl */
arfs_fsync, /* fsync */
arfs_readdir, /* readdir */
arfs_lookup, /* lookup */
arfs_create, /* create */
arfs_remove, /* remove */
arfs_rename, /* remame */
arfs_mkdir, /* mkdir */
arfs_rmdir, /* rmdir */
arfs_getattr, /* getattr */
arfs_setattr, /* setattr */
arfs_inactive, /* inactive */
arfs_truncate, /* truncate */
};
/*
* Read blocks.
* iobuf is filled by read data.
*/
static int
arfs_readblk(mount_t mp, int blkno)
{
struct buf *bp;
int err;
/*
* Read two blocks for archive header
*/
if ((err = bread(mp->m_dev, blkno, &bp)) != 0)
return err;
memcpy(iobuf, bp->b_data, BSIZE);
brelse(bp);
if ((err = bread(mp->m_dev, blkno + 1, &bp)) != 0)
return err;
memcpy(iobuf + BSIZE, bp->b_data, BSIZE);
brelse(bp);
return 0;
}
/*
* Lookup vnode for the specified file/directory.
* The vnode is filled properly.
*/
static int
arfs_lookup(vnode_t dvp, char *name, vnode_t vp)
{
struct ar_hdr *hdr;
int blkno, err;
off_t off;
size_t size;
mount_t mp;
char *p;
DPRINTF(("arfs_lookup: name=%s\n", name));
if (*name == '\0')
return ENOENT;
mutex_lock(&arfs_lock);
err = ENOENT;
mp = vp->v_mount;
blkno = 0;
off = SARMAG; /* offset in archive image */
for (;;) {
/* Read two blocks for archive header */
if (arfs_readblk(mp, blkno) != 0)
goto out;
/* Check file header */
hdr = (struct ar_hdr *)(iobuf + (off % BSIZE));
if (strncmp(hdr->ar_fmag, ARFMAG, sizeof(ARFMAG) - 1))
goto out;
/* Get file size */
size = (size_t)atol((char *)&hdr->ar_size);
if (size == 0)
goto out;
/* Convert archive name */
if ((p = memchr(&hdr->ar_name, '/', 16)) != NULL)
*p = '\0';
if (strncmp(name, (char *)&hdr->ar_name, 16) == 0)
break;
/* Proceed to next archive header */
off += (sizeof(struct ar_hdr) + size);
off += (off % 2); /* Pad to even boundary */
blkno = (int)(off / BSIZE);
}
vp->v_type = VREG;
/* No write access */
vp->v_mode = S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
vp->v_size = size;
vp->v_blkno = blkno;
vp->v_data = (void *)(off + sizeof(struct ar_hdr));
err = 0;
out:
mutex_unlock(&arfs_lock);
DPRINTF(("arfs_lookup: err=%d\n\n", err));
return err;
}
static int
arfs_read(vnode_t vp, file_t fp, void *buf, size_t size, size_t *result)
{
off_t off, file_pos, buf_pos;
int blkno, err;
size_t nr_read, nr_copy;
mount_t mp;
struct buf *bp;
DPRINTF(("arfs_read: start size=%d\n", size));
mutex_lock(&arfs_lock);
*result = 0;
mp = vp->v_mount;
/* Check if current file position is already end of file. */
file_pos = fp->f_offset;
if (file_pos >= (off_t)vp->v_size) {
err = 0;
goto out;
}
/* Get the actual read size. */
if (vp->v_size - file_pos < size)
size = vp->v_size - file_pos;
/* Read and copy data */
off = (off_t)vp->v_data;
nr_read = 0;
for (;;) {
DPRINTF(("arfs_read: file_pos=%d buf=%x size=%d\n",
file_pos, buf, size));
blkno = (off + file_pos) / BSIZE;
buf_pos = (off + file_pos) % BSIZE;
if ((err = bread(mp->m_dev, blkno, &bp)) != 0)
goto out;
nr_copy = BSIZE;
if (buf_pos > 0)
nr_copy -= buf_pos;
if (buf_pos + size < BSIZE)
nr_copy = size;
ASSERT(nr_copy > 0);
memcpy(buf, bp->b_data + buf_pos, nr_copy);
brelse(bp);
file_pos += nr_copy;
DPRINTF(("arfs_read: file_pos=%d nr_copy=%d\n",
file_pos, nr_copy));
nr_read += nr_copy;
size -= nr_copy;
if (size <= 0)
break;
buf = (void *)((u_long)buf + nr_copy);
buf_pos = 0;
}
fp->f_offset = file_pos;
*result = nr_read;
err = 0;
out:
mutex_unlock(&arfs_lock);
DPRINTF(("arfs_read: err=%d\n\n", err));
return err;
}
/*
* Check if the seek offset is valid.
*/
static int
arfs_seek(vnode_t vp, file_t fp, off_t oldoff, off_t newoff)
{
if (newoff > (off_t)vp->v_size)
return -1;
return 0;
}
static int
arfs_readdir(vnode_t vp, file_t fp, struct dirent *dir)
{
struct ar_hdr *hdr;
int blkno, i, err;
off_t off;
size_t size;
mount_t mp;
char *p;
DPRINTF(("arfs_readdir: start\n"));
mutex_lock(&arfs_lock);
i = 0;
mp = vp->v_mount;
blkno = 0;
off = SARMAG; /* offset in archive image */
for (;;) {
/* Read two blocks for archive header */
if ((err = arfs_readblk(mp, blkno)) != 0)
goto out;
hdr = (struct ar_hdr *)(iobuf + (off % BSIZE));
/* Get file size */
size = (size_t)atol((char *)&hdr->ar_size);
if (size == 0) {
err = ENOENT;
goto out;
}
if (i == fp->f_offset)
break;
/* Proceed to next archive header */
off += (sizeof(struct ar_hdr) + size);
off += (off % 2); /* Pad to even boundary */
blkno = off / BSIZE;
i++;
}
/* Convert archive name */
if ((p = memchr(&hdr->ar_name, '/', 16)) != NULL)
*p = '\0';
strcpy((char *)&dir->d_name, (char *)&hdr->ar_name);
dir->d_namlen = strlen(dir->d_name);
dir->d_fileno = fp->f_offset;
dir->d_type = DT_REG;
fp->f_offset++;
err = 0;
out:
mutex_unlock(&arfs_lock);
return err;
}
int
arfs_init(void)
{
return 0;
}