File: [local] / prex / usr / server / fs / ramfs / ramfs_vnops.c (download)
Revision 1.1.1.1 (vendor branch), Tue Aug 19 12:47:01 2008 UTC (15 years, 10 months 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.
*/
/*
* rmafs_vnops.c - vnode operations for RAM file system.
*/
#include <prex/prex.h>
#include <sys/stat.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/mount.h>
#include <sys/dirent.h>
#include <sys/param.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include "ramfs.h"
#define ramfs_open ((vnop_open_t)vop_nullop)
#define ramfs_close ((vnop_close_t)vop_nullop)
static int ramfs_read (vnode_t, file_t, void *, size_t, size_t *);
static int ramfs_write (vnode_t, file_t, void *, size_t, size_t *);
#define ramfs_seek ((vnop_seek_t)vop_nullop)
#define ramfs_ioctl ((vnop_ioctl_t)vop_einval)
#define ramfs_fsync ((vnop_fsync_t)vop_nullop)
static int ramfs_readdir(vnode_t, file_t, struct dirent *);
static int ramfs_lookup (vnode_t, char *, vnode_t);
static int ramfs_create (vnode_t, char *, mode_t);
static int ramfs_remove (vnode_t, vnode_t, char *);
static int ramfs_rename (vnode_t, vnode_t, char *, vnode_t, vnode_t, char *);
static int ramfs_mkdir (vnode_t, char *, mode_t);
static int ramfs_rmdir (vnode_t, vnode_t, char *);
#define ramfs_getattr ((vnop_getattr_t)vop_nullop)
#define ramfs_setattr ((vnop_setattr_t)vop_nullop)
#define ramfs_inactive ((vnop_inactive_t)vop_nullop)
static int ramfs_truncate(vnode_t);
#if CONFIG_FS_THREADS > 1
static mutex_t ramfs_lock = MUTEX_INITIALIZER;
#endif
/*
* vnode operations
*/
struct vnops ramfs_vnops = {
ramfs_open, /* open */
ramfs_close, /* close */
ramfs_read, /* read */
ramfs_write, /* write */
ramfs_seek, /* seek */
ramfs_ioctl, /* ioctl */
ramfs_fsync, /* fsync */
ramfs_readdir, /* readdir */
ramfs_lookup, /* lookup */
ramfs_create, /* create */
ramfs_remove, /* remove */
ramfs_rename, /* remame */
ramfs_mkdir, /* mkdir */
ramfs_rmdir, /* rmdir */
ramfs_getattr, /* getattr */
ramfs_setattr, /* setattr */
ramfs_inactive, /* inactive */
ramfs_truncate, /* truncate */
};
struct ramfs_node *
ramfs_allocate_node(char *name, int type)
{
struct ramfs_node *np;
np = malloc(sizeof(struct ramfs_node));
if (np == NULL)
return NULL;
memset(np, 0, sizeof(struct ramfs_node));
np->rn_namelen = strlen(name);
np->rn_name = malloc(np->rn_namelen + 1);
if (np->rn_name == NULL) {
free(np);
return NULL;
}
strcpy(np->rn_name, name);
np->rn_type = type;
return np;
}
void
ramfs_free_node(struct ramfs_node *np)
{
free(np->rn_name);
free(np);
}
static struct ramfs_node *
ramfs_add_node(struct ramfs_node *dnp, char *name, int type)
{
struct ramfs_node *np, *prev;
np = ramfs_allocate_node(name, type);
if (np == NULL)
return NULL;
mutex_lock(&ramfs_lock);
/* Link to the directory list */
if (dnp->rn_child == NULL) {
dnp->rn_child = np;
} else {
prev = dnp->rn_child;
while (prev->rn_next != NULL)
prev = prev->rn_next;
prev->rn_next = np;
}
mutex_unlock(&ramfs_lock);
return np;
}
static int
ramfs_remove_node(struct ramfs_node *dnp, struct ramfs_node *np)
{
struct ramfs_node *prev;
if (dnp->rn_child == NULL)
return EBUSY;
mutex_lock(&ramfs_lock);
/* Unlink from the directory list */
if (dnp->rn_child == np) {
dnp->rn_child = np->rn_next;
} else {
for (prev = dnp->rn_child; prev->rn_next != np;
prev = prev->rn_next) {
if (prev->rn_next == NULL) {
mutex_unlock(&ramfs_lock);
return ENOENT;
}
}
prev->rn_next = np->rn_next;
}
ramfs_free_node(np);
mutex_unlock(&ramfs_lock);
return 0;
}
static int
ramfs_rename_node(struct ramfs_node *np, char *name)
{
size_t len;
char *tmp;
len = strlen(name);
if (len <= np->rn_namelen) {
/* Reuse current name buffer */
strcpy(np->rn_name, name);
} else {
/* Expand name buffer */
tmp = malloc(len + 1);
if (tmp == NULL)
return ENOMEM;
strcpy(tmp, name);
free(np->rn_name);
np->rn_name = tmp;
}
np->rn_namelen = len;
return 0;
}
static int
ramfs_lookup(vnode_t dvp, char *name, vnode_t vp)
{
struct ramfs_node *np, *dnp;
size_t len;
int found;
if (*name == '\0')
return ENOENT;
mutex_lock(&ramfs_lock);
len = strlen(name);
dnp = dvp->v_data;
found = 0;
for (np = dnp->rn_child; np != NULL; np = np->rn_next) {
if (np->rn_namelen == len &&
memcmp(name, np->rn_name, len) == 0) {
found = 1;
break;
}
}
if (found == 0) {
mutex_unlock(&ramfs_lock);
return ENOENT;
}
vp->v_data = np;
vp->v_mode = ALLPERMS;
vp->v_type = np->rn_type;
vp->v_size = np->rn_size;
mutex_unlock(&ramfs_lock);
return 0;
}
static int
ramfs_mkdir(vnode_t dvp, char *name, mode_t mode)
{
struct ramfs_node *np;
DPRINTF(("mkdir %s\n", name));
if (!S_ISDIR(mode))
return EINVAL;
np = ramfs_add_node(dvp->v_data, name, VDIR);
if (np == NULL)
return ENOMEM;
np->rn_size = 0;
return 0;
}
/* Remove a directory */
static int
ramfs_rmdir(vnode_t dvp, vnode_t vp, char *name)
{
return ramfs_remove_node(dvp->v_data, vp->v_data);
}
/* Remove a file */
static int
ramfs_remove(vnode_t dvp, vnode_t vp, char *name)
{
struct ramfs_node *np;
int err;
DPRINTF(("remove %s in %s\n", name, dvp->v_path));
err = ramfs_remove_node(dvp->v_data, vp->v_data);
if (err)
return err;
np = vp->v_data;
if (np->rn_buf != NULL)
vm_free(task_self(), np->rn_buf);
return 0;
}
/* Truncate file */
static int
ramfs_truncate(vnode_t vp)
{
struct ramfs_node *np;
DPRINTF(("truncate %s\n", vp->v_path));
np = vp->v_data;
if (np->rn_buf != NULL) {
vm_free(task_self(), np->rn_buf);
np->rn_buf = NULL;
np->rn_bufsize = 0;
}
vp->v_size = 0;
return 0;
}
/*
* Create empty file.
*/
static int
ramfs_create(vnode_t dvp, char *name, mode_t mode)
{
struct ramfs_node *np;
DPRINTF(("create %s in %s\n", name, dvp->v_path));
if (!S_ISREG(mode))
return EINVAL;
np = ramfs_add_node(dvp->v_data, name, VREG);
if (np == NULL)
return ENOMEM;
return 0;
}
static int
ramfs_read(vnode_t vp, file_t fp, void *buf, size_t size, size_t *result)
{
struct ramfs_node *np;
off_t off;
*result = 0;
if (vp->v_type == VDIR)
return EISDIR;
if (vp->v_type != VREG)
return EINVAL;
off = fp->f_offset;
if (off >= (off_t)vp->v_size)
return 0;
if (vp->v_size - off < size)
size = vp->v_size - off;
np = vp->v_data;
memcpy(buf, np->rn_buf + off, size);
fp->f_offset += size;
*result = size;
return 0;
}
static int
ramfs_write(vnode_t vp, file_t fp, void *buf, size_t size, size_t *result)
{
struct ramfs_node *np;
off_t file_pos, end_pos;
void *new_buf;
size_t new_size;
task_t task;
*result = 0;
if (vp->v_type == VDIR)
return EISDIR;
if (vp->v_type != VREG)
return EINVAL;
np = vp->v_data;
/* Check if the file position exceeds the end of file. */
end_pos = vp->v_size;
file_pos = (fp->f_flags & O_APPEND) ? end_pos : fp->f_offset;
if (file_pos + size > (size_t)end_pos) {
/* Expand the file size before writing to it */
end_pos = file_pos + size;
if (end_pos > (off_t)np->rn_bufsize) {
task = task_self();
/*
* We allocate the data buffer in page boundary.
* So that we can reduce the memory allocation unless
* the file size exceeds next page boundary.
* This will prevent the memory fragmentation by
* many malloc/free calls.
*/
new_size = PAGE_ALIGN(end_pos);
if (vm_allocate(task, &new_buf, new_size, 1))
return EIO;
if (np->rn_size != 0) {
memcpy(new_buf, np->rn_buf, vp->v_size);
vm_free(task, np->rn_buf);
}
np->rn_buf = new_buf;
np->rn_bufsize = new_size;
}
np->rn_size = end_pos;
vp->v_size = end_pos;
}
memcpy(np->rn_buf + file_pos, buf, size);
fp->f_offset += size;
*result = size;
return 0;
}
static int
ramfs_rename(vnode_t dvp1, vnode_t vp1, char *name1,
vnode_t dvp2, vnode_t vp2, char *name2)
{
struct ramfs_node *np, *old_np;
int err;
if (vp2) {
/* Remove destination file, first */
err = ramfs_remove_node(dvp2->v_data, vp2->v_data);
if (err)
return err;
}
/* Same directory ? */
if (dvp1 == dvp2) {
/* Change the name of existing file */
err = ramfs_rename_node(vp1->v_data, name2);
if (err)
return err;
} else {
/* Create new file or directory */
old_np = vp1->v_data;
np = ramfs_add_node(dvp2->v_data, name2, VREG);
if (np == NULL)
return ENOMEM;
if (vp1->v_type == VREG) {
/* Copy file data */
np->rn_buf = old_np->rn_buf;
np->rn_size = old_np->rn_size;
np->rn_bufsize = old_np->rn_bufsize;
}
/* Remove source file */
ramfs_remove_node(dvp1->v_data, vp1->v_data);
}
return 0;
}
/*
* @vp: vnode of the directory.
*/
static int
ramfs_readdir(vnode_t vp, file_t fp, struct dirent *dir)
{
struct ramfs_node *np, *dnp;
int i;
mutex_lock(&ramfs_lock);
if (fp->f_offset == 0) {
dir->d_type = DT_DIR;
strcpy((char *)&dir->d_name, ".");
} else if (fp->f_offset == 1) {
dir->d_type = DT_DIR;
strcpy((char *)&dir->d_name, "..");
} else {
dnp = vp->v_data;
np = dnp->rn_child;
if (np == NULL) {
mutex_unlock(&ramfs_lock);
return ENOENT;
}
for (i = 0; i != (fp->f_offset - 2); i++) {
np = np->rn_next;
if (np == NULL) {
mutex_unlock(&ramfs_lock);
return ENOENT;
}
}
if (np->rn_type == VDIR)
dir->d_type = DT_DIR;
else
dir->d_type = DT_REG;
strcpy((char *)&dir->d_name, np->rn_name);
}
dir->d_fileno = fp->f_offset;
dir->d_namlen = strlen(dir->d_name);
fp->f_offset++;
mutex_unlock(&ramfs_lock);
return 0;
}
int
ramfs_init(void)
{
return 0;
}