aboutsummaryrefslogtreecommitdiff
path: root/CS3871/filesystem
diff options
context:
space:
mode:
Diffstat (limited to 'CS3871/filesystem')
-rw-r--r--CS3871/filesystem/README.rst0
-rw-r--r--CS3871/filesystem/disk.h17
-rw-r--r--CS3871/filesystem/disk.obin0 -> 3352 bytes
-rw-r--r--CS3871/filesystem/tfs.c352
4 files changed, 369 insertions, 0 deletions
diff --git a/CS3871/filesystem/README.rst b/CS3871/filesystem/README.rst
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/CS3871/filesystem/README.rst
diff --git a/CS3871/filesystem/disk.h b/CS3871/filesystem/disk.h
new file mode 100644
index 0000000..7bf6ad0
--- /dev/null
+++ b/CS3871/filesystem/disk.h
@@ -0,0 +1,17 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#define TRACKS 128
+#define SECTORS 4096
+
+/* 10ms per track change */
+/* 10ms/SECTORS per unit sector distance > 1 */
+
+void dinit();
+
+void rsector(int t,int s,unsigned char *b);
+
+void wsector(int t,int s,unsigned char *b);
+
+
diff --git a/CS3871/filesystem/disk.o b/CS3871/filesystem/disk.o
new file mode 100644
index 0000000..b1a36f8
--- /dev/null
+++ b/CS3871/filesystem/disk.o
Binary files differ
diff --git a/CS3871/filesystem/tfs.c b/CS3871/filesystem/tfs.c
new file mode 100644
index 0000000..fe2d94c
--- /dev/null
+++ b/CS3871/filesystem/tfs.c
@@ -0,0 +1,352 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/time.h>
+#include "disk.h"
+
+#define MAX_INODES 1000
+#define INODE_START (TRACKS * SECTORS) / (8 * 512)
+#define MAX_FILES 50
+
+struct block_ptr {
+ char track;
+ short sector;
+};
+struct blockll{
+ struct block_ptr data;
+ struct blockll *next;
+};
+
+struct meta_data{
+ char name[8];
+ int size;
+ int read;
+ int write;
+ int create;
+};
+
+struct inode {
+ struct meta_data info;
+ struct block_ptr data[20];
+};
+
+
+struct inode_list{
+ struct inode *node;
+ struct inode_list *next;
+};
+
+struct file {
+ struct inode *node;
+ int mode;
+ int next_sec;
+ int free;
+};
+
+
+int inode_list_size = 0;
+struct inode_list *root, *end;
+
+char bitmap[TRACKS][SECTORS/8];
+
+struct file files[MAX_FILES];
+int size;
+
+
+
+int check_bitmap(t,s)
+int t,s;
+{
+ char tmp;
+ tmp = bitmap[t][s/8];
+ tmp &= (1 << (s % 8));
+ return (int) tmp;
+}
+
+void set_bitmap(t,s)
+int t,s;
+{
+ bitmap[t][s/8] |= (1 << (s % 8));
+ return;
+}
+
+void print_bitmap()
+{
+ int i,j;
+ for(i = 0; i < 128; i++){
+
+ printf("\n%4d ", i);
+ for (j = 0; j < 4096/8; j++) {
+ printf("%02x", bitmap[i][j]);
+ if (j %31 == 0) {
+ printf("\n%4d ",i);
+ }
+ }
+ }
+}
+
+
+/* TODO
+ * Implement inode table as binary tree to speedup searches
+ */
+struct inode* inode_search(name)
+char *name;
+{
+ if (strcmp(name,"") == 0) {
+ return -1;
+ }
+ int i;
+ struct inode_list *tmp = root;
+
+ for(i = 0; i < MAX_INODES && i < inode_list_size; i++){
+ tmp = tmp->next;
+ if(strcmp(name, tmp->node->info.name) == 0)
+ return tmp->node;
+ }
+ return -2;
+}
+
+struct blockll* get_blocks(size)
+int size;
+{
+ int i, t, s;
+ struct blockll *root, *current = malloc(sizeof(struct blockll));
+ root = current;
+
+ for (i = 0; size > 0 && i < (4096 * 128); i++) {
+ t = i / 4096;
+ s = i % 4096;
+
+ if (!check_bitmap(t, s)) {
+ current->next = malloc(sizeof(struct blockll));
+ current = current->next;
+ current-> next = NULL;
+ current->data.track = (char) t;
+ current->data.sector = (short) s;
+
+ set_bitmap(t,s);
+ size-= 512;
+ }
+ }
+
+ return i <(4096 * 128) ? root : NULL;
+}
+
+struct inode_list* inode_create(name)
+char *name;
+{
+ struct timeval *tmp_time = malloc(sizeof(struct timeval));
+
+ struct inode_list *tmp = malloc(sizeof(struct inode_list));
+ struct inode *tmp_node = malloc(sizeof(struct inode));
+
+
+ tmp->node = tmp_node;
+
+ memcpy(&(tmp->node->info.name), name, strlen(name));
+
+ gettimeofday(tmp_time, NULL);
+
+ tmp->node->info.create = tmp_time->tv_sec;
+ tmp->node->info.read = tmp_time->tv_sec;
+ tmp->node->info.write = tmp_time->tv_sec;
+
+ end->next = tmp;
+ end = tmp;
+ inode_list_size++;
+
+ return tmp;
+}
+
+int inode_init()
+{
+ int n = MAX_INODES / 4;
+ int i;
+ char *ptr;
+ struct inode_list *tmp;
+
+ if (MAX_INODES % 4 > 0)
+ n++;
+
+ char *buf = malloc(512 * n);
+
+ for (i =0; i < n; i++) {
+ rsector(0, i, buf + (512 * i));
+ }
+ ptr = buf;
+
+ tmp = root;
+
+ for(i=0; i< MAX_INODES; i++) {
+ tmp->next = malloc(sizeof(struct inode_list));
+ memcpy(&tmp->node, ptr, 64);
+ ptr += 64;
+ tmp = tmp->next;
+ inode_list_size++;
+ }
+}
+
+/*save inodes to first n sectors on disk*/
+void inode_save()
+{
+ int i, j;
+ char *buf = malloc(512);
+ struct inode_list *tmp = root;
+
+ for (i = 0; i < MAX_INODES && tmp->next;i++) {
+ for (j = 0; j < 4; j++){
+ tmp = tmp->next;
+ memcpy(buf + j, tmp->node, sizeof(struct inode));
+ }
+ wsector(0, INODE_START + i, buf);
+ }
+}
+
+struct inode* inode_from_fd(fd)
+int fd;
+{
+ int i;
+ struct inode_list *tmp = root;
+
+ for (i = 0; i < fd; i++) {
+ tmp = tmp->next;
+ }
+
+ return tmp->node;
+}
+
+int find_fd()
+{
+ int i;
+ for (i = 0; i < size; i++) {
+ if (files[i].free)
+ return i;
+ }
+}
+
+int tfs_init()
+{
+ int i;
+ root = malloc(sizeof(struct inode_list));
+ end = root;
+
+ dinit();
+ /*
+ *
+ * has issue if inodes have not been written to disk i.e. first run
+ inode_init();
+ */
+ for (i = 0; i < MAX_FILES; i++) {
+ files[i].free = 1;
+ }
+}
+
+
+int open(fname, mode)
+char *fname, *mode;
+{
+ struct inode *fnode = inode_search(fname);
+ int fd;
+
+ if (fnode == -1)
+ return -1;
+
+ if (fnode == -2){
+ fnode = inode_create(fname)->node;
+ }
+ fd = find_fd();
+
+ files[fd].node = fnode;
+ files[fd].mode = *mode;
+ files[fd].next_sec = 0;
+ files[fd].free = 0;
+ size++;
+
+ return fd;
+}
+
+int close(fd)
+int fd;
+{
+ if (files[fd].free)
+ return -1;
+
+ files[fd].free = 1;
+ return 1;
+}
+
+int read(fd, buf)
+int fd;
+char *buf;
+{
+ if (files[fd].free || files[fd].mode || (files[fd].next_sec == 20))
+ return -1;
+
+
+ rsector(files[fd].node->data[files[fd].next_sec].track, files[fd].node->data[files[fd].next_sec].sector, buf);
+ files[fd].next_sec++;
+ return 512;
+}
+
+int write(fd, buf)
+int fd;
+char *buf;
+{
+ if ((files[fd].next_sec == 20) || !files[fd].mode)
+ return 0;
+
+ struct blockll *tmp = get_blocks(500);
+ files[fd].node->data[files[fd].next_sec].track = tmp->data.track;
+ files[fd].node->data[files[fd].next_sec].sector = tmp->data.sector;
+
+ wsector(files[fd].node->data[files[fd].next_sec].track, files[fd].node->data[files[fd].next_sec].sector, buf);
+ return 1;
+}
+
+int ulink(fname)
+char *fname;
+{
+ struct inode_list *tmp = root;
+ struct inode *d;
+ int i;
+
+ for(i = 0; i < MAX_INODES && i < inode_list_size; i++){
+ tmp = tmp->next;
+ if(strcmp(fname, tmp->next->node->info.name) == 0)
+ break;;
+ }
+
+ d = tmp->next->node;
+ tmp->next = tmp->next->next;
+ free(d);
+ return 1;
+ }
+
+int main()
+{
+ tfs_init();
+
+ /*
+ *Test Writing
+ */
+ int mode = 1;
+ int fd = open("test", &mode);
+
+ char buf[512];
+ memcpy(&buf, "Hello Filesystem", strlen("Hello Filesystem"));
+
+ int test = write(fd, &buf);
+ close(fd);
+
+ /*
+ *Test reading
+ */
+ mode = 0;
+ fd = open("test", &mode);
+ char buf2[512];
+ read(fd, &buf2);
+ printf("wrote: %s\n", buf);
+
+ printf("read: %s\n", buf2);
+
+}
generated by cgit v1.1 at 2024-12-22 22:37:50 +0000