rt-thread-official/components/dfs/dfs_v2/filesystems/romfs/dfs_romfs.c

398 lines
9.5 KiB
C

/*
* Copyright (c) 2006-2023, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
*/
#include <rtthread.h>
#include <dfs.h>
#include <dfs_fs.h>
#include <dfs_dentry.h>
#include <dfs_file.h>
#include <dfs_mnt.h>
#include "dfs_romfs.h"
#include <errno.h>
#include <fcntl.h>
#include <rtdbg.h>
static const struct dfs_file_ops _rom_fops;
static const mode_t romfs_modemap[] =
{
S_IFREG | 0644, /* regular file */
S_IFDIR | 0644, /* directory */
0, /* hard link */
S_IFLNK | 0777, /* symlink */
S_IFBLK | 0600, /* blockdev */
S_IFCHR | 0600, /* chardev */
S_IFSOCK | 0644, /* socket */
S_IFIFO | 0644 /* FIFO */
};
static int dfs_romfs_mount(struct dfs_mnt *mnt, unsigned long rwflag, const void *data)
{
struct romfs_dirent *root_dirent;
if (data == NULL)
return -1;
root_dirent = (struct romfs_dirent *)data;
mnt->data = root_dirent;
return 0;
}
static int dfs_romfs_umount(struct dfs_mnt *fs)
{
return RT_EOK;
}
int dfs_romfs_ioctl(struct dfs_file *file, int cmd, void *args)
{
int ret = RT_EOK;
struct romfs_dirent *dirent;
dirent = (struct romfs_dirent *)file->data;
RT_ASSERT(dirent != NULL);
switch (cmd)
{
case RT_FIOGETADDR:
{
*(rt_ubase_t*)args = (rt_ubase_t)dirent->data;
break;
}
case RT_FIOFTRUNCATE:
{
break;
}
default:
ret = -RT_EINVAL;
break;
}
return ret;
}
rt_inline int check_dirent(struct romfs_dirent *dirent)
{
if (dirent == NULL
||(dirent->type != ROMFS_DIRENT_FILE && dirent->type != ROMFS_DIRENT_DIR)
|| dirent->size == ~0)
return -1;
return 0;
}
struct romfs_dirent *__dfs_romfs_lookup(struct romfs_dirent *root_dirent, const char *path, rt_size_t *size)
{
rt_size_t index, found;
const char *subpath, *subpath_end;
struct romfs_dirent *dirent;
rt_size_t dirent_size;
/* Check the root_dirent. */
if (check_dirent(root_dirent) != 0)
return NULL;
if (path[0] == '/' && path[1] == '\0')
{
*size = root_dirent->size;
return root_dirent;
}
/* goto root directy entries */
dirent = (struct romfs_dirent *)root_dirent->data;
dirent_size = root_dirent->size;
/* get the end position of this subpath */
subpath_end = path;
/* skip /// */
while (*subpath_end && *subpath_end == '/')
subpath_end ++;
subpath = subpath_end;
while ((*subpath_end != '/') && *subpath_end)
subpath_end ++;
while (dirent != NULL)
{
found = 0;
/* search in folder */
for (index = 0; index < dirent_size; index ++)
{
if (check_dirent(&dirent[index]) != 0)
return NULL;
if (rt_strlen(dirent[index].name) == (subpath_end - subpath) &&
rt_strncmp(dirent[index].name, subpath, (subpath_end - subpath)) == 0)
{
dirent_size = dirent[index].size;
/* skip /// */
while (*subpath_end && *subpath_end == '/')
subpath_end ++;
subpath = subpath_end;
while ((*subpath_end != '/') && *subpath_end)
subpath_end ++;
if (!(*subpath))
{
*size = dirent_size;
return &dirent[index];
}
if (dirent[index].type == ROMFS_DIRENT_DIR)
{
/* enter directory */
dirent = (struct romfs_dirent *)dirent[index].data;
found = 1;
break;
}
else
{
/* return file dirent */
return &dirent[index];
}
}
}
if (!found)
break; /* not found */
}
/* not found */
return NULL;
}
static struct dfs_vnode *dfs_romfs_lookup (struct dfs_dentry *dentry)
{
rt_size_t size;
struct dfs_vnode *vnode = RT_NULL;
struct romfs_dirent *root_dirent = RT_NULL, *dirent = RT_NULL;
RT_ASSERT(dentry != RT_NULL);
RT_ASSERT(dentry->mnt != RT_NULL);
root_dirent = (struct romfs_dirent *)dentry->mnt->data;
if (check_dirent(root_dirent) == 0)
{
/* create a vnode */
DLOG(msg, "rom", "vnode", DLOG_MSG, "dfs_vnode_create()");
vnode = dfs_vnode_create();
if (vnode)
{
dirent = __dfs_romfs_lookup(root_dirent, dentry->pathname, &size);
if (dirent)
{
vnode->nlink = 1;
vnode->size = dirent->size;
if (dirent->type == ROMFS_DIRENT_DIR)
{
vnode->mode = romfs_modemap[ROMFS_DIRENT_DIR] | S_IRUSR;
vnode->type = FT_DIRECTORY;
}
else if (dirent->type == ROMFS_DIRENT_FILE)
{
vnode->mode = romfs_modemap[ROMFS_DIRENT_FILE] | S_IRUSR | S_IXUSR;
vnode->type = FT_REGULAR;
}
DLOG(msg, "rom", "rom", DLOG_MSG, "vnode->data = dirent");
vnode->data = dirent;
vnode->mnt = dentry->mnt;
}
else
{
/* no-entry */
DLOG(msg, "rom", "vnode", DLOG_MSG, "dfs_vnode_destroy, no-dentry");
dfs_vnode_destroy(vnode);
vnode = RT_NULL;
}
}
}
return vnode;
}
static int dfs_romfs_free_vnode(struct dfs_vnode *vnode)
{
/* nothing to be freed */
if (vnode->ref_count <= 1)
{
vnode->data = NULL;
}
return 0;
}
static ssize_t dfs_romfs_read(struct dfs_file *file, void *buf, size_t count, off_t *pos)
{
rt_size_t length;
struct romfs_dirent *dirent;
dirent = (struct romfs_dirent *)file->vnode->data;
RT_ASSERT(dirent != NULL);
if (check_dirent(dirent) != 0)
{
return -EIO;
}
if (count < file->vnode->size - *pos)
length = count;
else
length = file->vnode->size - *pos;
if (length > 0)
memcpy(buf, &(dirent->data[*pos]), length);
/* update file current position */
*pos += length;
return length;
}
static int dfs_romfs_close(struct dfs_file *file)
{
return RT_EOK;
}
int dfs_romfs_open(struct dfs_file *file)
{
rt_size_t size;
struct romfs_dirent *dirent;
struct romfs_dirent *root_dirent;
struct dfs_mnt *mnt;
if (file->flags & (O_CREAT | O_WRONLY | O_APPEND | O_TRUNC | O_RDWR))
{
return -EINVAL;
}
mnt = file->dentry->mnt;
RT_ASSERT(mnt != RT_NULL);
root_dirent = (struct romfs_dirent *)mnt->data;
if (check_dirent(root_dirent) != 0)
{
return -EIO;
}
/* get rom dirent */
dirent = __dfs_romfs_lookup(root_dirent, file->dentry->pathname, &size);
if (dirent == NULL)
{
return -ENOENT;
}
file->data = dirent;
file->fops = &_rom_fops;
file->fpos = 0;
return RT_EOK;
}
static int dfs_romfs_stat(struct dfs_dentry *dentry, struct stat *st)
{
rt_err_t ret = dfs_file_lock();
if (ret == RT_EOK)
{
st->st_dev = 0;
st->st_mode = dentry->vnode->mode;
st->st_size = dentry->vnode->size;
st->st_nlink = dentry->vnode->nlink;
st->st_mtime = 0;
dfs_file_unlock();
}
return RT_EOK;
}
static int dfs_romfs_getdents(struct dfs_file *file, struct dirent *dirp, uint32_t count)
{
rt_size_t index;
const char *name;
struct dirent *d;
struct romfs_dirent *dirent, *sub_dirent;
dirent = (struct romfs_dirent *)file->vnode->data;
if (check_dirent(dirent) != 0)
{
return -EIO;
}
RT_ASSERT(dirent->type == ROMFS_DIRENT_DIR);
/* enter directory */
dirent = (struct romfs_dirent *)dirent->data;
/* make integer count */
count = (count / sizeof(struct dirent));
if (count == 0)
{
return -EINVAL;
}
index = 0;
for (index = 0; index < count && file->fpos < file->vnode->size; index++)
{
d = dirp + index;
sub_dirent = &dirent[file->fpos];
name = sub_dirent->name;
/* fill dirent */
if (sub_dirent->type == ROMFS_DIRENT_DIR)
d->d_type = DT_DIR;
else
d->d_type = DT_REG;
d->d_namlen = rt_strlen(name);
d->d_reclen = (rt_uint16_t)sizeof(struct dirent);
rt_strncpy(d->d_name, name, rt_strlen(name) + 1);
/* move to next position */
++ file->fpos;
}
return index * sizeof(struct dirent);
}
static const struct dfs_file_ops _rom_fops =
{
.open = dfs_romfs_open,
.close = dfs_romfs_close,
.lseek = generic_dfs_lseek,
.read = dfs_romfs_read,
.getdents = dfs_romfs_getdents,
};
static const struct dfs_filesystem_ops _romfs_ops =
{
.name ="rom",
.flags = 0,
.default_fops = &_rom_fops,
.mount = dfs_romfs_mount,
.umount = dfs_romfs_umount,
.stat = dfs_romfs_stat,
.lookup = dfs_romfs_lookup,
.free_vnode = dfs_romfs_free_vnode
};
static struct dfs_filesystem_type _romfs =
{
.fs_ops = &_romfs_ops,
};
int dfs_romfs_init(void)
{
/* register rom file system */
dfs_register(&_romfs);
return 0;
}
INIT_COMPONENT_EXPORT(dfs_romfs_init);