fix(lab6): imporve lab6

src/lab6/fs/Makefile

@@ -1,11 +1,9 @@
-# ASM_SRC		= $(filter-out ramdisk.S, $(sort $(wildcard *.S)))
 C_SRC       = $(sort $(wildcard *.c))
-OBJ		    = $(patsubst %.S,%.o,$(ASM_SRC)) $(patsubst %.c,%.o,$(C_SRC))
+OBJ		    = $(patsubst %.c,%.o,$(C_SRC))
 
 all:$(OBJ)
 
 %.o:%.c
 	${GCC} ${CFLAG} -c $<
-
 clean:
-	$(shell rm *.o 2>/dev/null)
+	$(shell rm *.o 2>/dev/null)

src/lab6/fs/fat32.c

@@ -1,12 +1,11 @@
-#include <fat32.h>
-#include <printk.h>
-#include <virtio.h>
-#include <string.h>
-#include <mbr.h>
-#include <mm.h>
+#include "fat32.h"
+#include "printk.h"
+#include "virtio.h"
+#include "string.h"
+#include "mbr.h"
+#include "mm.h"
 
 struct fat32_bpb fat32_header;
-
 struct fat32_volume fat32_volume;
 
 uint8_t fat32_buf[VIRTIO_BLK_SECTOR_SIZE];
@@ -30,9 +29,6 @@ void fat32_init(uint64_t lba, uint64_t size) {
     fat32_volume.sec_per_cluster = 0/* to calculate */;
     fat32_volume.first_data_sec = 0/* to calculate */;
     fat32_volume.fat_sz = 0/* to calculate */;
-
-    virtio_blk_read_sector(fat32_volume.first_data_sec, fat32_buf); // Get the root directory
-    struct fat32_dir_entry *dir_entry = (struct fat32_dir_entry *)fat32_buf;
 }
 
 int is_fat32(uint64_t lba) {
@@ -43,7 +39,7 @@ int is_fat32(uint64_t lba) {
     return 1;
 }
 
-int next_slash(const char* path) {
+int next_slash(const char* path) {  // util function to be used in fat32_open_file
     int i = 0;
     while (path[i] != '\0' && path[i] != '/') {
         i++;
@@ -54,7 +50,7 @@ int next_slash(const char* path) {
     return i;
 }
 
-void to_upper_case(char *str) {
+void to_upper_case(char *str) {     // util function to be used in fat32_open_file
     for (int i = 0; str[i] != '\0'; i++) {
         if (str[i] >= 'a' && str[i] <= 'z') {
             str[i] -= 32;
@@ -87,60 +83,12 @@ uint64_t fat32_table_sector_of_cluster(uint32_t cluster) {
     return fat32_volume.first_fat_sec + cluster / (VIRTIO_BLK_SECTOR_SIZE / sizeof(uint32_t));
 }
 
-int64_t fat32_extend_filesz(struct file* file, uint64_t new_size) {
-    uint64_t sector = cluster_to_sector(file->fat32_file.dir.cluster) + file->fat32_file.dir.index / FAT32_ENTRY_PER_SECTOR;
-
-    virtio_blk_read_sector(sector, fat32_table_buf);
-    uint32_t index = file->fat32_file.dir.index % FAT32_ENTRY_PER_SECTOR;
-    uint32_t original_file_len = ((struct fat32_dir_entry *)fat32_table_buf)[index].size;
-    ((struct fat32_dir_entry *)fat32_table_buf)[index].size = new_size;
-
-    virtio_blk_write_sector(sector, fat32_table_buf);
-
-    uint32_t clusters_required = new_size / (fat32_volume.sec_per_cluster * VIRTIO_BLK_SECTOR_SIZE);
-    uint32_t clusters_original = original_file_len / (fat32_volume.sec_per_cluster * VIRTIO_BLK_SECTOR_SIZE);
-    uint32_t new_clusters = clusters_required - clusters_original;
-
-    uint32_t cluster = file->fat32_file.cluster;
-    while (1) {
-        uint32_t next_cluster_number = next_cluster(cluster);
-        if (next_cluster_number >= 0x0ffffff8) {
-            break;
-        }
-        cluster = next_cluster_number;
-    }
-
-    for (int i = 0; i < new_clusters; i++) {
-        uint32_t cluster_to_append;
-        for (int j = 2; j < fat32_volume.fat_sz * VIRTIO_BLK_SECTOR_SIZE / sizeof(uint32_t); j++) {
-            if (next_cluster(j) == 0) {
-                cluster_to_append = j;
-                break;
-            }
-        }
-        uint64_t fat_sector = fat32_table_sector_of_cluster(cluster);
-        virtio_blk_read_sector(fat_sector, fat32_table_buf);
-        uint32_t index_in_sector = cluster * 4 % VIRTIO_BLK_SECTOR_SIZE;
-        *(uint32_t*)(fat32_table_buf + index_in_sector) = cluster_to_append;
-        virtio_blk_write_sector(fat_sector, fat32_table_buf);
-        cluster = cluster_to_append;
-    }
-
-    uint64_t fat_sector = fat32_table_sector_of_cluster(cluster);
-    virtio_blk_read_sector(fat_sector, fat32_table_buf);
-    uint32_t index_in_sector = cluster * 4 % VIRTIO_BLK_SECTOR_SIZE;
-    *(uint32_t*)(fat32_table_buf + index_in_sector) = 0x0fffffff;
-    virtio_blk_write_sector(fat_sector, fat32_table_buf);
-
-    return 0;
-}
-
 int64_t fat32_read(struct file* file, void* buf, uint64_t len) {
-    return 0;
     /* todo: read content to buf, and return read length */
+    return 0;
 }
 
 int64_t fat32_write(struct file* file, const void* buf, uint64_t len) {
-    return 0;
     /* todo: fat32_write */
+    return 0;
 }

src/lab6/fs/fs.c

@@ -0,0 +1,46 @@
+#include "fs.h"
+#include "vfs.h"
+#include "mm.h"
+#include "string.h"
+#include "printk.h"
+#include "fat32.h"
+
+struct files_struct *file_init() {
+    // todo: alloc pages for files_struct, and initialize stdin, stdout, stderr
+    struct files_struct *ret = NULL;
+    return ret;
+}
+
+uint32_t get_fs_type(const char *filename) {
+    uint32_t ret;
+    if (memcmp(filename, "/fat32/", 7) == 0) {
+        ret = FS_TYPE_FAT32;
+    } else if (memcmp(filename, "/ext2/", 6) == 0) {
+        ret = FS_TYPE_EXT2;
+    } else {
+        ret = -1;
+    }
+    return ret;
+}
+
+int32_t file_open(struct file* file, const char* path, int flags) {
+    file->opened = 1;
+    file->perms = flags;
+    file->cfo = 0;
+    file->fs_type = get_fs_type(path);
+    memcpy(file->path, path, strlen(path) + 1);
+
+    if (file->fs_type == FS_TYPE_FAT32) {
+        file->lseek = fat32_lseek;
+        file->write = fat32_write;
+        file->read = fat32_read;
+        file->fat32_file = fat32_open_file(path);
+        // todo: check if fat32_file is valid (i.e. successfully opened) and return
+    } else if (file->fs_type == FS_TYPE_EXT2) {
+        printk(RED "Unsupport ext2\n" CLEAR);
+        return -1;
+    } else {
+        printk(RED "Unknown fs type: %s\n" CLEAR, path);
+        return -1;
+    }
+}

src/lab6/fs/mbr.c

@@ -1,9 +1,8 @@
-#include <mbr.h>
-#include <virtio.h>
-#include <fat32.h>
+#include "mbr.h"
+#include "virtio.h"
+#include "fat32.h"
 
 uint8_t mbr_buf[VIRTIO_BLK_SECTOR_SIZE];
-
 struct partition_info partitions[MBR_MAX_PARTITIONS];
 
 void mbr_init() {
@@ -12,8 +11,6 @@ void mbr_init() {
     for (int i = 0; i < 4; i++) {
         if (mbr->partition_table[i].type == 0x83) {
             uint32_t lba = mbr->partition_table[i].lba_first_sector;
-            // virtio_blk_read_sector(lba, mbr_buf);
-            // printk("[S] Detect partition%d offset: %d, len:%d, type:%x\n", i+1, lba, mbr->partition_table[i].sector_count, mbr->partition_table[i].type);
             partition_init(i + 1, lba, mbr->partition_table[i].sector_count);
         }
     }
@@ -22,6 +19,6 @@ void mbr_init() {
 void partition_init(int partion_number, uint64_t start_lba, uint64_t sector_count) {
     if (is_fat32(start_lba)) {
         fat32_init(start_lba, sector_count);
-        printk("[S] fat32 partition init done!\n", partion_number);
+        printk("...fat32 partition #%d init done!\n", partion_number);
     }
-}
+}