int vfs_read(openfile_t file, void *buffer, int bufsize)
{
openfile_entry_t *openfile;
fs_t *fs;
int ret;
if (vfs_start_op() != VFS_OK)
return VFS_UNUSABLE;
openfile = vfs_verify_open(file);
fs = openfile->filesystem;
KERNEL_ASSERT(bufsize >= 0 && buffer != NULL);
ret = fs->read(fs, openfile->fileid, buffer, bufsize,
openfile->seek_position);
if(ret > 0) {
semaphore_P(openfile_table.sem);
openfile->seek_position += ret;
semaphore_V(openfile_table.sem);
}
vfs_end_op();
return ret;
}
/**
* Removes given file from filesystem.
*
* @param pathname Full name of the file, including mountpoint.
*
* @return VFS_OK on success, negative (VFS_*) on failure.
*
*/
int vfs_remove(const char *pathname)
{
char volumename[VFS_NAME_LENGTH];
char filename[VFS_NAME_LENGTH];
fs_t *fs = NULL;
int ret;
if (vfs_start_op() != VFS_OK)
return VFS_UNUSABLE;
if (vfs_parse_pathname(pathname, volumename, filename) != VFS_OK) {
vfs_end_op();
return VFS_INVALID_PARAMS;
}
semaphore_P(vfs_table.sem);
fs = vfs_get_filesystem(volumename);
if(fs == NULL) {
semaphore_V(vfs_table.sem);
vfs_end_op();
return VFS_NO_SUCH_FS;
}
ret = fs->remove(fs, filename);
semaphore_V(vfs_table.sem);
vfs_end_op();
return ret;
}
/**
* Gets number of free bytes on given filesystem identified by
* mountpoint-name.
*
* @param filesystem Name of mountpoint
*
* @return Number of free bytes, negative values (VFS_*) are errors.
*
*/
int vfs_getfree(const char *filesystem)
{
fs_t *fs = NULL;
int ret;
if (vfs_start_op() != VFS_OK)
return VFS_UNUSABLE;
semaphore_P(vfs_table.sem);
fs = vfs_get_filesystem(filesystem);
if(fs == NULL) {
semaphore_V(vfs_table.sem);
vfs_end_op();
return VFS_NO_SUCH_FS;
}
ret = fs->getfree(fs);
semaphore_V(vfs_table.sem);
vfs_end_op();
return ret;
}
/**
* Seek given file to given position. The position is not verified
* to be within the file's size.
*
* @param file Open file
*
* @param seek_position New positive seek position.
*
* @return VFS_OK, panics on invalid arguments.
*
*/
int vfs_seek(openfile_t file, int seek_position)
{
openfile_entry_t *openfile;
if (vfs_start_op() != VFS_OK)
return VFS_UNUSABLE;
if(seek_position < 0) {
return VFS_INVALID_PARAMS;
}
semaphore_P(openfile_table.sem);
openfile = vfs_verify_open(file);
if (openfile == NULL) {
semaphore_V(openfile_table.sem);
return VFS_NOT_OPEN;
}
openfile->seek_position = seek_position;
semaphore_V(openfile_table.sem);
vfs_end_op();
return VFS_OK;
}
/**
* Close open file.
*
* @param file Openfile id
*
* @return VFS_OK on success, negative (VFS_*) on error.
*
*/
int vfs_close(openfile_t file)
{
openfile_entry_t *openfile;
fs_t *fs;
int ret;
if (vfs_start_op() != VFS_OK)
return VFS_UNUSABLE;
semaphore_P(openfile_table.sem);
openfile = vfs_verify_open(file);
if (openfile == NULL) {
semaphore_V(openfile_table.sem);
return VFS_NOT_OPEN;
}
fs = openfile->filesystem;
ret = fs->close(fs, openfile->fileid);
openfile->filesystem = NULL;
semaphore_V(openfile_table.sem);
vfs_end_op();
return ret;
}
int vfs_create(char *pathname, int size)
{
char volumename[VFS_NAME_LENGTH];
char filename[VFS_NAME_LENGTH];
fs_t *fs = NULL;
int ret;
KERNEL_ASSERT(size >= 0);
if (vfs_start_op() != VFS_OK)
return VFS_UNUSABLE;
if(vfs_parse_pathname(pathname, volumename, filename) != VFS_OK) {
vfs_end_op();
return VFS_ERROR;
}
semaphore_P(vfs_table.sem);
fs = vfs_get_filesystem(volumename);
if(fs == NULL) {
semaphore_V(vfs_table.sem);
vfs_end_op();
return VFS_NO_SUCH_FS;
}
ret = fs->create(fs, filename, size);
semaphore_V(vfs_table.sem);
vfs_end_op();
return ret;
}
int vfs_file(char *pathname, int idx, char *buffer)
{
char volumename[VFS_NAME_LENGTH];
char dirname[VFS_NAME_LENGTH];
fs_t *fs = NULL;
int ret;
if (vfs_start_op() != VFS_OK)
return VFS_UNUSABLE;
if (pathname == NULL) {
semaphore_P(vfs_table.sem);
for (ret = 0; ret < CONFIG_MAX_FILESYSTEMS && idx != 0; ret++) {
if (vfs_table.filesystems[ret].filesystem != NULL)
idx--;
}
/* Error can be caused if idx was <= 0 or idx was higher than the
* number of mounted volumes
*/
if (idx != 0) {
semaphore_V(vfs_table.sem);
vfs_end_op();
return VFS_ERROR;
}
stringcopy(buffer, vfs_table.filesystems[ret].mountpoint, VFS_NAME_LENGTH);
semaphore_V(vfs_table.sem);
vfs_end_op();
return VFS_OK;
}
if (vfs_parse_pathname(pathname, volumename, dirname) != VFS_OK) {
vfs_end_op();
return VFS_ERROR;
}
semaphore_P(vfs_table.sem);
fs = vfs_get_filesystem(volumename);
if(fs == NULL) {
semaphore_V(vfs_table.sem);
vfs_end_op();
return VFS_NO_SUCH_FS;
}
ret = fs->file(fs, dirname, idx, buffer);
semaphore_V(vfs_table.sem);
vfs_end_op();
return ret;
}
int vfs_seek(openfile_t file, int seek_position)
{
openfile_entry_t *openfile;
if (vfs_start_op() != VFS_OK)
return VFS_UNUSABLE;
KERNEL_ASSERT(seek_position >= 0);
semaphore_P(openfile_table.sem);
openfile = vfs_verify_open(file);
openfile->seek_position = seek_position;
semaphore_V(openfile_table.sem);
vfs_end_op();
return VFS_OK;
}
int vfs_mount(fs_t *fs, char *name)
{
int i;
int row;
KERNEL_ASSERT(name != NULL && name[0] != '\0');
if (vfs_start_op() != VFS_OK)
return VFS_UNUSABLE;
semaphore_P(vfs_table.sem);
for (i = 0; i < CONFIG_MAX_FILESYSTEMS; i++) {
if (vfs_table.filesystems[i].filesystem == NULL)
break;
}
row = i;
if(row >= CONFIG_MAX_FILESYSTEMS) {
semaphore_V(vfs_table.sem);
kprintf("VFS: Warning, maximum mount count exceeded, mount failed.\n");
vfs_end_op();
return VFS_LIMIT;
}
for (i = 0; i < CONFIG_MAX_FILESYSTEMS; i++) {
if(stringcmp(vfs_table.filesystems[i].mountpoint, name) == 0) {
semaphore_V(vfs_table.sem);
kprintf("VFS: Warning, attempt to mount 2 filesystems "
"with same name\n");
vfs_end_op();
return VFS_ERROR;
}
}
stringcopy(vfs_table.filesystems[row].mountpoint, name, VFS_NAME_LENGTH);
vfs_table.filesystems[row].filesystem = fs;
semaphore_V(vfs_table.sem);
vfs_end_op();
return VFS_OK;
}
int vfs_filecount(char *pathname)
{
char volumename[VFS_NAME_LENGTH];
char dirname[VFS_NAME_LENGTH];
fs_t *fs = NULL;
int ret;
if (vfs_start_op() != VFS_OK)
return VFS_UNUSABLE;
if (pathname == NULL) {
semaphore_P(vfs_table.sem);
for (ret = 0; ret < CONFIG_MAX_FILESYSTEMS; ret++) {
if (vfs_table.filesystems[ret].filesystem == NULL)
break;
}
semaphore_V(vfs_table.sem);
vfs_end_op();
return ret;
}
if (vfs_parse_pathname(pathname, volumename, dirname) != VFS_OK) {
vfs_end_op();
return VFS_ERROR;
}
semaphore_P(vfs_table.sem);
fs = vfs_get_filesystem(volumename);
if(fs == NULL) {
semaphore_V(vfs_table.sem);
vfs_end_op();
return VFS_NO_SUCH_FS;
}
ret = fs->filecount(fs, dirname);
semaphore_V(vfs_table.sem);
vfs_end_op();
return ret;
}
int vfs_unmount(char *name)
{
int i, row;
fs_t *fs = NULL;
if (vfs_start_op() != VFS_OK)
return VFS_UNUSABLE;
semaphore_P(vfs_table.sem);
for (row = 0; row < CONFIG_MAX_FILESYSTEMS; row++) {
if(!stringcmp(vfs_table.filesystems[row].mountpoint, name)) {
fs = vfs_table.filesystems[row].filesystem;
break;
}
}
if(fs == NULL) {
semaphore_V(vfs_table.sem);
vfs_end_op();
return VFS_NOT_FOUND;
}
semaphore_P(openfile_table.sem);
for(i = 0; i < CONFIG_MAX_OPEN_FILES; i++) {
if(openfile_table.files[i].filesystem == fs) {
semaphore_V(openfile_table.sem);
semaphore_V(vfs_table.sem);
vfs_end_op();
return VFS_IN_USE;
}
}
fs->unmount(fs);
vfs_table.filesystems[row].filesystem = NULL;
semaphore_V(openfile_table.sem);
semaphore_V(vfs_table.sem);
vfs_end_op();
return VFS_OK;
}
/**
* Tells the given file's position.
*
* @param file Open file
*
* @return the file's seek position. Negative values on error
*
*/
int vfs_tell(openfile_t file)
{
openfile_entry_t *openfile;
if (vfs_start_op() != VFS_OK)
return VFS_UNUSABLE;
semaphore_P(openfile_table.sem);
openfile = vfs_verify_open(file);
if (openfile == NULL) {
semaphore_V(openfile_table.sem);
return VFS_NOT_OPEN;
}
int seek_position = openfile->seek_position;
semaphore_V(openfile_table.sem);
vfs_end_op();
return seek_position;
}
/**
* Writes datasize bytes from given buffer to given open file.
* The write is started from current seek position and after writing, the
* position is updated.
*
* @param file Open file
*
* @param buffer Buffer to be written to file.
*
* @param datasize Number of bytes to write.
*
* @return Number of bytes written. All bytes are written unless error
* prevented to do that. Negative values are specific error conditions.
*
*/
int vfs_write(openfile_t file, void *buffer, int datasize)
{
openfile_entry_t *openfile;
fs_t *fs;
int fileid, seek_position, ret;
if (datasize < 0 || buffer == NULL) {
return VFS_INVALID_PARAMS;
}
if (vfs_start_op() != VFS_OK)
return VFS_UNUSABLE;
semaphore_P(openfile_table.sem);
openfile = vfs_verify_open(file);
if (openfile == NULL) {
semaphore_V(openfile_table.sem);
return VFS_NOT_OPEN;
}
fs = openfile->filesystem;
fileid = openfile->fileid;
seek_position = openfile->seek_position;
semaphore_V(openfile_table.sem);
ret = fs->write(fs, fileid, buffer, datasize, seek_position);
if(ret > 0) {
semaphore_P(openfile_table.sem);
openfile->seek_position += ret;
semaphore_V(openfile_table.sem);
}
vfs_end_op();
return ret;
}
openfile_t vfs_open(char *pathname)
{
openfile_t file;
int fileid;
char volumename[VFS_NAME_LENGTH];
char filename[VFS_NAME_LENGTH];
fs_t *fs = NULL;
if (vfs_start_op() != VFS_OK)
return VFS_UNUSABLE;
if (vfs_parse_pathname(pathname, volumename, filename) != VFS_OK) {
vfs_end_op();
return VFS_ERROR;
}
semaphore_P(vfs_table.sem);
semaphore_P(openfile_table.sem);
for(file=0; file<CONFIG_MAX_OPEN_FILES; file++) {
if(openfile_table.files[file].filesystem == NULL) {
break;
}
}
if(file >= CONFIG_MAX_OPEN_FILES) {
semaphore_V(openfile_table.sem);
semaphore_V(vfs_table.sem);
kprintf("VFS: Warning, maximum number of open files exceeded.");
vfs_end_op();
return VFS_LIMIT;
}
fs = vfs_get_filesystem(volumename);
if(fs == NULL) {
semaphore_V(openfile_table.sem);
semaphore_V(vfs_table.sem);
vfs_end_op();
return VFS_NO_SUCH_FS;
}
openfile_table.files[file].filesystem = fs;
semaphore_V(openfile_table.sem);
semaphore_V(vfs_table.sem);
fileid = fs->open(fs, filename);
if(fileid < 0) {
semaphore_P(openfile_table.sem);
openfile_table.files[file].filesystem = NULL;
semaphore_V(openfile_table.sem);
vfs_end_op();
return fileid; /* negative -> error*/
}
openfile_table.files[file].fileid = fileid;
openfile_table.files[file].seek_position = 0;
vfs_end_op();
return file;
}
