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

323 lines
7.2 KiB
C

/*
* Copyright (c) 2006-2018, 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_file.h>
#include "dfs_romfs.h"
int dfs_romfs_mount(struct dfs_filesystem *fs, unsigned long rwflag, const void *data)
{
struct romfs_dirent *root_dirent;
if (data == NULL)
return -EIO;
root_dirent = (struct romfs_dirent *)data;
fs->data = root_dirent;
return RT_EOK;
}
int dfs_romfs_unmount(struct dfs_filesystem *fs)
{
return RT_EOK;
}
int dfs_romfs_ioctl(struct dfs_fd *file, int cmd, void *args)
{
return -EIO;
}
rt_inline int check_dirent(struct romfs_dirent *dirent)
{
if ((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 */
if (subpath != NULL)
break; /* not the end of path */
return &dirent[index];
}
}
}
if (!found)
break; /* not found */
}
/* not found */
return NULL;
}
int dfs_romfs_read(struct dfs_fd *file, void *buf, size_t count)
{
rt_size_t length;
struct romfs_dirent *dirent;
dirent = (struct romfs_dirent *)file->data;
RT_ASSERT(dirent != NULL);
if (check_dirent(dirent) != 0)
{
return -EIO;
}
if (count < file->size - file->pos)
length = count;
else
length = file->size - file->pos;
if (length > 0)
memcpy(buf, &(dirent->data[file->pos]), length);
/* update file current position */
file->pos += length;
return length;
}
int dfs_romfs_lseek(struct dfs_fd *file, off_t offset)
{
if (offset <= file->size)
{
file->pos = offset;
return file->pos;
}
return -EIO;
}
int dfs_romfs_close(struct dfs_fd *file)
{
file->data = NULL;
return RT_EOK;
}
int dfs_romfs_open(struct dfs_fd *file)
{
rt_size_t size;
struct romfs_dirent *dirent;
struct romfs_dirent *root_dirent;
struct dfs_filesystem *fs;
fs = (struct dfs_filesystem *)file->data;
root_dirent = (struct romfs_dirent *)fs->data;
if (check_dirent(root_dirent) != 0)
return -EIO;
if (file->flags & (O_CREAT | O_WRONLY | O_APPEND | O_TRUNC | O_RDWR))
return -EINVAL;
dirent = dfs_romfs_lookup(root_dirent, file->path, &size);
if (dirent == NULL)
return -ENOENT;
/* entry is a directory file type */
if (dirent->type == ROMFS_DIRENT_DIR)
{
if (!(file->flags & O_DIRECTORY))
return -ENOENT;
}
else
{
/* entry is a file, but open it as a directory */
if (file->flags & O_DIRECTORY)
return -ENOENT;
}
file->data = dirent;
file->size = size;
file->pos = 0;
return RT_EOK;
}
int dfs_romfs_stat(struct dfs_filesystem *fs, const char *path, struct stat *st)
{
rt_size_t size;
struct romfs_dirent *dirent;
struct romfs_dirent *root_dirent;
root_dirent = (struct romfs_dirent *)fs->data;
dirent = dfs_romfs_lookup(root_dirent, path, &size);
if (dirent == NULL)
return -ENOENT;
st->st_dev = 0;
st->st_mode = S_IFREG | S_IRUSR | S_IRGRP | S_IROTH |
S_IWUSR | S_IWGRP | S_IWOTH;
if (dirent->type == ROMFS_DIRENT_DIR)
{
st->st_mode &= ~S_IFREG;
st->st_mode |= S_IFDIR | S_IXUSR | S_IXGRP | S_IXOTH;
}
st->st_size = dirent->size;
st->st_mtime = 0;
return RT_EOK;
}
int dfs_romfs_getdents(struct dfs_fd *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->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->pos < file->size; index ++)
{
d = dirp + index;
sub_dirent = &dirent[file->pos];
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->pos;
}
return index * sizeof(struct dirent);
}
static const struct dfs_file_ops _rom_fops =
{
dfs_romfs_open,
dfs_romfs_close,
dfs_romfs_ioctl,
dfs_romfs_read,
NULL,
NULL,
dfs_romfs_lseek,
dfs_romfs_getdents,
};
static const struct dfs_filesystem_ops _romfs =
{
"rom",
DFS_FS_FLAG_DEFAULT,
&_rom_fops,
dfs_romfs_mount,
dfs_romfs_unmount,
NULL,
NULL,
NULL,
dfs_romfs_stat,
NULL,
};
int dfs_romfs_init(void)
{
/* register rom file system */
dfs_register(&_romfs);
return 0;
}
INIT_COMPONENT_EXPORT(dfs_romfs_init);