/*! Remove a file */
bool remove(const char *f_name) {
struct dir* cur_dir;
char name[15];
/* Checks the validity of the given pointer */
//printf("going to remove file %s\n\n", f_name);
if (!checkva(f_name))
exit(-1);
if (!decompose_dir(f_name, name, &cur_dir))
return false;
if (strcmp(".", name) == 0 || strcmp("..", name) == 0)
return false;
lock_acquire(&filesys_lock);
/* Remove the file, while locking the file system. */
bool flag = filesys_dir_remove(name, cur_dir);
//printf("name decomposed! %x\n\n", cur_dir);
dir_close(cur_dir);
lock_release(&filesys_lock);
return flag;
}
/*! Read from file */
int read(uint32_t fd, void *buffer, unsigned size) {
uint8_t* addr_e;
struct supp_table* st;
/* Check the validity of given pointer */
if ((!checkva(buffer)) || (!checkva(buffer + size))){
exit(-1);
}
for (addr_e = (uint8_t*) pg_round_down(buffer);
addr_e < (uint8_t*) buffer + size; addr_e += PGSIZE){
st = find_supp_table(addr_e);
if (st && !st->writable)
exit(-1);
}
int read_size = 0;
if (fd == STDIN_FILENO) {
/* If std-in, then read using input_getc() */
unsigned i;
for (i = 0; i < size; i++){
*((uint8_t*) buffer) = input_getc();
++ read_size;
++ buffer;
}
} else {
/* Otherwise, first find the file of this fd. */
struct f_info* f = findfile(fd);
/* We should read a dir like a file. */
if (f->isdir)
exit(-1);
struct file* fin = f->f;
off_t pos = f->pos;
/* Read from the file at f->pos */
//lock_acquire(&filesys_lock);
read_size = (int) file_read_at(fin, buffer, (off_t) size, pos);
f->pos += (off_t) read_size;
//lock_release(&filesys_lock);
}
return read_size;
}
// Copy data to/from user space,
// using checkva() above to validate the address range
// and using sysrecover() to recover from any traps during the copy.
void usercopy(trapframe *utf, bool copyout,
void *kva, uint32_t uva, size_t size) {
checkva(utf, uva, size);
cpu *c = cpu_cur();
c->recover = sysrecover;
if(copyout)
memmove((void*)uva, kva, size);
else
memmove(kva, (void*)uva, size);
c->recover = NULL;
}
/*! Write to file. */
int write(uint32_t fd, const void *buffer, unsigned size) {
uint8_t* addr_e;
struct supp_table *st;
/* Check the validity of given pointer */
if ((!checkva(buffer)) || (!checkva(buffer + size)))
exit(-1);
/* Checking we are not writing to unwritable pages. */
int write_size = 0;
if (fd == STDOUT_FILENO) {
/* If std-out, then write using putbuf() */
putbuf(buffer, size);
write_size = size;
} else {
/* Otherwise, first find the file of this fd. */
struct f_info* f = findfile(fd);
/* We should write to a directory just like a file. */
if (f->isdir)
exit(-1);
struct file* fout = f->f;
off_t pos = f->pos;
/* Write to the file at f->pos */
//lock_acquire(&filesys_lock);
write_size = (int) file_write_at(fout, buffer, (off_t) size, pos);
f->pos += (off_t) write_size;
//lock_release(&filesys_lock);
}
return write_size;
}
/*! Reads a directory entry from file descriptor fd. If successful, stores,
* the null-terminated file name in name. If no entries are left in
* directory, returns false. */
bool _readdir(uint32_t fd, char* name){
/* Check for the validity of the pointer. */
if (!checkva(name))
return false;
/* Get the f_info struct of this fd*/
struct f_info* f = findfile(fd);
/*Check that we are opening a directory. */
if (!f->isdir)
return false;
/* Use the defined dir_readir to finish the function. */
return dir_readdir(f->d, name);
}
/*! Create a file */
bool create(const char *f_name, unsigned initial_size) {
struct dir* cur_dir;
char name[15];
/* Checks the validity of the given pointer */
if (!checkva(f_name) || !(*f_name))
exit(-1);
if (!decompose_dir(f_name, name, &cur_dir)){
return false;
}
lock_acquire(&filesys_lock);
/* Create the file, while locking the file system. */
bool flag = filesys_dir_create(name, (off_t) initial_size, cur_dir);
dir_close(cur_dir);
lock_release(&filesys_lock);
return flag;
}
/*! Creates the directory named dir. Return true if successful, but false
* if dir already exists or if any directory name in dir, besides the last
* one does not exist. */
bool _mkdir(const char* dir) {
/* Inode for the new directory created. */
struct inode* next_inode;
/* Parent directory. */
struct dir* cur_dir;
/* Name of the directory. */
char name[15];
/* Sector number allocated to the new directory. */
block_sector_t sector;
/* Check the validity of the pointer*/
if (!checkva(dir))
exit(-1);
/* The compose the path to a final dir name and its parent directory. */
if (!decompose_dir(dir, name, &cur_dir)){
return false;
}
ASSERT(cur_dir != NULL);
/* Allocate a new sector for this new directory;
* Create a new directory */
if (!free_map_allocate(1, §or) ||
!dir_create(sector, 0, dir_get_inode(cur_dir)->sector)){
dir_close(cur_dir);
return false;
}
/* Add the new directory to its parent directory. */
if (!dir_add(cur_dir, name, sector)){
free_map_release(sector, 1);
dir_close(cur_dir);
return false;
}
dir_close(cur_dir);
return true;
}
/*! Changes the working directory of the current process (i.e.
* thread->cur_dir). Returns true if the operation is successfull
* and false otherwise. */
bool _chdir(const char* dir){
/* The current process*/
struct thread* t = thread_current();
/* inode for the new directory*/
struct inode* next_inode;
/* new directory struct*/
struct dir* cur_dir;
/* name of the directory*/
char name[15];
/* Check validity of the pointer*/
if (!checkva(dir)){
exit(-1);
}
/* Decompose the path to a final name and parent directory. */
if (!decompose_dir(dir, name, &cur_dir))
return false;
if (strcmp(name, "\0") != 0){
/* If name is not empty, then we simply look for the name
* under the parent directory cur_dir, and get the inode
* of this destination directory. */
if (!dir_lookup(cur_dir, name, &next_inode)) {
dir_close(cur_dir);
return false;
}
/* Close the parent directory, as we do not need it any more. */
dir_close(cur_dir);
/* Check that the inode we are opening is a directory. */
if (next_inode->data.type != DIR_INODE_DISK) {
inode_close(next_inode);
return false;
}
/* Open up the inode to directory struct*/
cur_dir = dir_open(next_inode);
if (cur_dir == NULL) {
inode_close(next_inode);
return false;
}
} else if (dir[strlen(dir)] != '/'){
/* If the name is not empty, and the give path does not end with "/"
* then this path is an invalid directory path.
* Note if the path is in fact valid and the name we get is empty,
* then the distiniation directory has been already opened in
* cur_dir. */
dir_close(cur_dir);
return false;
}
/* Update the current process's working directory */
dir_close(t->cur_dir);
t->cur_dir = dir_reopen(cur_dir);
dir_close(cur_dir);
return true;
}
/*! Memory map from file to user address. */
mapid_t mmap(uint32_t fd, void* addr){
int f_size;
void* addr_e;
mapid_t mapid;
uint32_t read_bytes, zero_bytes;
uint8_t *upage;
off_t ofs;
struct file* file;
struct f_info* f;
struct mmap_elem* me;
struct supp_table* st;
struct thread* t = thread_current();
if (!checkva(addr))
return MAP_FAIL;
/* Check for the invalid conditions:
* fd is standard io; file size of the given fd is 0; give user address
* is not valie; given address is not page aligned; given address is 0.
* If invalid, then return MAP_FAIL. */
if (fd == STDIN_FILENO ||
fd == STDOUT_FILENO ||
filesize(fd) == 0 ||
pg_ofs(addr) != 0 ||
addr == 0) {
return MAP_FAIL;
}
/* Get the file size of the file. And check the entire range of the
* to-be-mapped user address does not overlap with any already allocated
* pages. */
f_size = filesize(fd);
for (addr_e = addr; addr_e < addr + f_size; addr_e += PGSIZE){
if (find_supp_table(addr_e) != NULL){
/* If found a supplemental page entry of this page address,
* Then this is already alocated. Return MAP_FAIL. */
return MAP_FAIL;
}
}
/* Increment the thread's max mmapid to give this mmapping a unque ID. */
++ t->mmapid_max;
mapid = t->mmapid_max;
/* Allocated the new mmap struct */
me = (struct mmap_elem*) malloc(sizeof(struct mmap_elem));
if (me == NULL)
return MAP_FAIL;
/* Reopen the file according to the file descriptor. */
f = findfile(fd);
if (f->isdir)
return MAP_FAIL;
lock_acquire(&filesys_lock);
file = file_reopen(f->f);
lock_release(&filesys_lock);
/* If the file is NULL, then free the struct and return MAP_FAIL. */
if (file == NULL){
free(me);
return MAP_FAIL;
}
/* Setup the fields of the mmap struct.*/
me->file = file;
me->mapid = mapid;
/* Push the mmap struct to the list of mmap of this process. */
list_push_back(&(t->mmap_lst), &(me->elem));
list_init(&(me->s_table));
/* Allocate pages for the read-in file data.*/
upage = addr;
ofs = 0;
read_bytes = f_size;
if (read_bytes >= PGSIZE)
zero_bytes = 0;
else
zero_bytes = PGSIZE - read_bytes;
while (read_bytes > 0) {
/* Calculate how to fill this page.
We will read PAGE_READ_BYTES bytes from FILE
and zero the final PAGE_ZERO_BYTES bytes. */
size_t page_read_bytes = read_bytes < PGSIZE ? read_bytes : PGSIZE;
size_t page_zero_bytes = PGSIZE - page_read_bytes;
/* Create a new supplemental page entry for this page*/
st = create_mmap_supp_table(file, ofs, upage, page_read_bytes,
page_zero_bytes, true);
/* Push the page entry to the mmap struct's list */
list_push_back(&(me->s_table), &(st->map_elem));
/* Update the remaining read_bytes, zero_bytes;
* Update upage, and ofs. This is for the next page to load the file.*/
read_bytes -= page_read_bytes;
zero_bytes -= page_zero_bytes;
upage += PGSIZE;
ofs += page_read_bytes;
}
return mapid;
}
/*! Open a file or an directory */
int open(const char *f_name) {
/* The parent directory of the opening file or directory. */
struct dir* cur_dir;
/* Name of the file or the directory. */
char name[15];
/* CUrrent thread. */
struct thread *t;
/* file info struct for creating fd to this thread. */
struct f_info *f;
/* dir struct or file struct depending what we are opening */
struct dir* d_open;
struct file* f_open;
/* The flag for whether we are opening a directory. */
bool isdir;
/* fd number assigned to this file / directory */
uint32_t fd;
/* Inode of the file / dir we are opening. */
struct inode* inode;
/* Checks the validity of the given pointer */
if (!checkva(f_name) || f_name[0] == '\0'){
return -1;
}
/* Decomposes a path to the final file / dir name
* and its corresponding parent dir. */
if (!decompose_dir(f_name, name, &cur_dir)){
return -1;
}
/* Open the file when locking the file system. */
lock_acquire(&filesys_lock);
if (strcmp(name, "\0") != 0){
/* If file / dir name is not empty, then look for it in its parent
* directory. */
if (!dir_lookup(cur_dir, name, &inode)){
lock_release(&filesys_lock);
return -1;
}
/* Decide whether the inode is a directory or a file. */
isdir = (inode->data.type == DIR_INODE_DISK);
/* Open the file / dir */
if (isdir)
d_open = dir_open(inode);
else
f_open = file_open(inode);
lock_release(&filesys_lock);
} else {
/* Since we decomposed the entire path to a diretory
* then we must be opening a directory. */
isdir = true;
/* Reopen the directory, to store in f_info */
d_open = dir_reopen(cur_dir);
}
if (f_open == NULL && dir_open == NULL) {
inode_close(inode);
/* If file open failed, then exit with error. */
return -1;
} else {
/* Assign fd to the file / dir */
t = thread_current();
if (t->f_count > 127){
if (isdir){
dir_close(d_open);
} else {
file_close(f_open);
}
return -1;
}
/* Set up new f_info */
f = (struct f_info*) malloc(sizeof(struct f_info));
f->isdir = isdir;
if (isdir)
f->d = d_open;
else
f->f = f_open;
f->pos = 0;
/* Update the process's fd info */
lock_acquire(&filesys_lock);
fd = (++(t->fd_max));
f->fd = fd;
/* Push f_info to the thread's list,
* and update thread's list count. */
list_push_back(&(t->f_lst), &(f->elem));
++(t->f_count);
lock_release(&filesys_lock);
}
return fd;
}
/*! execute a command-line */
pid_t exec(const char *cmd_line) {
if (checkva(cmd_line))
return process_execute(cmd_line);
exit(-1);
}
/*! Reads for bytes from the stack according to the offset. */
static uint32_t read4(struct intr_frame * f, int offset) {
if (!checkva(f->esp + offset))
exit(-1);
return *((uint32_t *) (f->esp + offset));
}
