fuse文件系统示例

eBPF_Supermarket/Filesystem_Subsystem/fast_fuse/difuse/README.md

@@ -0,0 +1,32 @@
+# DIFUSE
+
+## 代码结构
+
+```
+.
+├── README.md
+├── src
+│   ├── difuse.c		源码
+│   ├── Makefile		
+│   └── mountpoints		挂载目录
+└── test
+    └── test.sh			测试脚本
+```
+
+
+
+## Build
+
+在`src`目录下执行`make`
+
+```bash
+cd src
+make
+```
+
+在`test`目录下执行`test`脚本
+
+```bash
+cd test
+./test.sh
+```

eBPF_Supermarket/Filesystem_Subsystem/fast_fuse/difuse/src/Makefile

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+# Makefile for FUSE difuse example
+
+# Compiler
+CC = gcc
+
+# Compiler flags
+CFLAGS = -Wall `pkg-config fuse3 --cflags`
+
+# Linker flags
+LDFLAGS = `pkg-config fuse3 --libs`
+
+# Source files
+SRCS = difuse.c
+
+# Output executable
+TARGET = difuse
+
+# Build target
+all: $(TARGET)
+
+# Rule to build the target
+$(TARGET): $(SRCS)
+	$(CC) $(CFLAGS) -o $(TARGET) $(SRCS) $(LDFLAGS)
+
+# Clean rule
+clean:
+	rm -f $(TARGET)
+
+.PHONY: all clean

eBPF_Supermarket/Filesystem_Subsystem/fast_fuse/difuse/src/difuse.c

@@ -0,0 +1,231 @@
+#define FUSE_USE_VERSION 31
+
+#include <fuse.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stddef.h>
+#include <assert.h>
+#include <errno.h> 
+
+/*相关数据结构*/
+
+#define FILE_TYPE 1
+#define DIRECTORY_TYPE 2
+
+
+struct dfs_data
+{
+    int chunk_size;
+    size_t size;
+    struct dfs_data *next;
+};
+
+struct dfs_inode
+{
+    uint32_t ino;                       //inode编号
+    int size;                           //文件大小
+    int dir_cnt;                        // 如果是目录类型文件，下面有几个目录项
+    struct dfs_data *data_pointer;      //指向数据块的指针
+};
+
+struct dfs_dentry
+{
+    char fname[255];
+    int ftype;
+    struct dfs_dentry *parent;
+    struct dfs_dentry *brother;
+    struct dfs_dentry *child;
+    struct dfs_inode *inode;            //指向对应的inode
+};
+
+struct dfs_dentry *root;                    //根节点
+
+/*过程函数*/
+static struct dfs_inode *new_inode(uint32_t ino, int size, int dir_cnt)
+{
+    struct dfs_inode *inode = (struct dfs_inode *)malloc(sizeof(struct dfs_inode));
+    inode->ino = ino;
+    inode->size = size;
+    inode->dir_cnt = dir_cnt;
+    inode->data_pointer = NULL;
+    return inode;
+}
+
+static struct dfs_dentry *new_dentry(char *fname, int ftype, struct dfs_dentry *parent, struct dfs_inode *inode)
+{
+    struct dfs_dentry *dentry = (struct dfs_dentry *)malloc(sizeof(struct dfs_dentry));
+    strcpy(dentry->fname, fname);
+    dentry->inode = inode;
+    dentry->brother = NULL;
+    dentry->parent = parent;
+    dentry->child = NULL;
+    dentry->ftype = ftype;
+    return dentry;
+}
+
+void add_child_dentry(struct dfs_dentry *parent, struct dfs_dentry *child)
+{
+    child->brother = parent->child;
+    parent->child = child;
+}
+
+struct dfs_dentry *look_up(struct dfs_dentry *dentrys, const char *path)
+{
+    struct dfs_dentry *dentry = dentrys;
+    char *path_copy = strdup(path);
+    char *token = strtok(path_copy, "/");
+    while (token != NULL && dentry != NULL)
+    {
+        struct dfs_dentry *child = dentry->child;
+        while (child != NULL && strcmp(child->fname, token) != 0)
+        {
+            child = child->brother;
+        }
+        dentry = child;
+        token = strtok(NULL, "/");
+    }
+
+    free(path_copy);
+    return dentry;
+}
+
+
+/*功能函数*/
+
+static int di_getattr(const char *path, struct stat *di_stat,
+    struct fuse_file_info *fi)
+{
+    (void)fi;
+    int ret = 0;
+    memset(di_stat, 0, sizeof(struct stat));
+
+    struct dfs_dentry *dentry = look_up(root, path);
+    if (dentry == NULL)
+        return -ENOENT;
+
+    if (dentry->ftype == DIRECTORY_TYPE)
+    {
+        di_stat->st_mode = S_IFDIR | 0755;
+        di_stat->st_nlink = 2;
+    }
+    else if (dentry->ftype == FILE_TYPE)
+    {
+        di_stat->st_mode = S_IFREG | 0644;
+        di_stat->st_nlink = 1;
+        di_stat->st_size = dentry->inode->size;
+    }
+
+    return ret;
+}
+
+/*遍历目录项*/
+static int di_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
+    off_t offset, struct fuse_file_info *fi)
+{
+    (void)fi;
+    (void)offset;
+    struct dfs_dentry *dentry = look_up(root, path);
+
+    if (dentry == NULL)
+        return -ENOENT;
+
+    if (dentry->ftype != DIRECTORY_TYPE)
+        return -ENOTDIR;
+
+    filler(buf, ".", NULL, 0, 0);
+    filler(buf, "..", NULL, 0, 0);
+
+    struct dfs_dentry *child = dentry->child;
+    while (child != NULL)
+    {
+        filler(buf, child->fname, NULL, 0, 0);
+        child = child->brother;
+    }
+
+    return 0;
+}
+
+static int di_open(const char *path, struct fuse_file_info *fi)
+{
+    struct dfs_dentry *dentry = look_up(root, path);
+
+    if (dentry == NULL)
+        return -ENOENT;
+
+    if (dentry->ftype != FILE_TYPE)
+        return -EISDIR;
+
+    return 0;
+}
+
+/*
+确保我们尝试从文件中读取的起始位置（偏移量）在文件范围内。
+如果偏移量超出了文件内容的长度，说明请求读取的位置在文件的末尾或之后，这种情况下不能读取任何数据。
+*/
+static int di_read(const char *path, char *buf, size_t size, off_t offset,
+    struct fuse_file_info *fi)
+{
+    struct dfs_dentry *dentry = look_up(root, path);
+
+    if (dentry == NULL)
+        return -ENOENT;
+
+    if (dentry->ftype != FILE_TYPE)
+        return -EISDIR;
+
+    if (offset < dentry->inode->size)
+    {
+        if (offset + size > dentry->inode->size)
+            size = dentry->inode->size - offset;
+        memcpy(buf, "dummy_content", size);  // Replace with actual file data handling
+    }
+    else
+        size = 0;
+
+    return size;
+}
+
+
+static struct fuse_operations difs_ops = {
+    .readdir = di_readdir,
+    .getattr = di_getattr,
+    .open = di_open,
+    .read = di_read,
+    //.mkdir = di_mkdir,
+};
+
+int main(int argc, char *argv[])
+{
+    struct dfs_inode *root_inode = new_inode(1, 0, 2);
+    root = new_dentry("/", DIRECTORY_TYPE, NULL, root_inode);
+
+    // 创建dir1目录
+    struct dfs_inode *dir1_inode = new_inode(2, 0, 2);
+    struct dfs_dentry *dir1 = new_dentry("dir1", DIRECTORY_TYPE, root, dir1_inode);
+    add_child_dentry(root, dir1);
+
+    // 创建dir2目录
+    struct dfs_inode *dir2_inode = new_inode(3, 0, 1);
+    struct dfs_dentry *dir2 = new_dentry("dir2", DIRECTORY_TYPE, root, dir2_inode);
+    add_child_dentry(root, dir2);
+
+    // 创建file1文件
+    struct dfs_inode *file1_inode = new_inode(4, 100, 0);
+    struct dfs_dentry *file1 = new_dentry("file1", FILE_TYPE, dir1, file1_inode);
+    add_child_dentry(dir1, file1);
+
+    // 创建file2文件
+    struct dfs_inode *file2_inode = new_inode(5, 200, 0);
+    struct dfs_dentry *file2 = new_dentry("file2", FILE_TYPE, dir1, file2_inode);
+    add_child_dentry(dir1, file2);
+
+    // 创建file3文件
+    struct dfs_inode *file3_inode = new_inode(6, 150, 0);
+    struct dfs_dentry *file3 = new_dentry("file3", FILE_TYPE, dir2, file3_inode);
+    add_child_dentry(dir2, file3);
+
+    return fuse_main(argc, argv, &difs_ops, NULL);
+}

eBPF_Supermarket/Filesystem_Subsystem/fast_fuse/difuse/test/test.sh

@@ -0,0 +1,87 @@
+#!/bin/bash
+
+# 挂载点目录
+MOUNT_POINT="../src/mountpoints"
+SRC_DIR="../src"
+
+# FUSE 可执行文件
+FUSE_EXEC="../src/difuse"
+
+echo "Compiling FUSE filesystem..."
+make -C "$SRC_DIR" clean
+make -C "$SRC_DIR" all
+
+# 检查编译是否成功
+if [ ! -f "$FUSE_EXEC" ]; then
+    echo "Compilation failed. Exiting."
+    exit 1
+fi
+
+# 创建挂载点目录（如果不存在）
+if [ ! -d "$MOUNT_POINT" ]; then
+    mkdir -p "$MOUNT_POINT"
+fi
+
+# 挂载 FUSE 文件系统（前台运行并显示调试信息）
+echo "Mounting FUSE filesystem..."
+$FUSE_EXEC -f -d "$MOUNT_POINT" &
+FUSE_PID=$!
+sleep 1  # 等待文件系统完全挂载
+
+# 测试读取根目录
+echo "Testing readdir on root..."
+ls "$MOUNT_POINT"
+
+# 测试读取子目录 dir1
+echo "Testing readdir on dir1..."
+ls "$MOUNT_POINT/dir1"
+
+# 测试读取子目录 dir2
+echo "Testing readdir on dir2..."
+ls "$MOUNT_POINT/dir2"
+
+# 测试读取文件 file1
+echo "Testing read file1..."
+cat "$MOUNT_POINT/dir1/file1"
+
+# 测试读取文件 file2
+echo "Testing read file2..."
+cat "$MOUNT_POINT/dir1/file2"
+
+# 测试读取文件 file3
+echo "Testing read file3..."
+cat "$MOUNT_POINT/dir2/file3"
+
+# 测试打开文件
+echo "Testing open file..."
+if [ -e "$MOUNT_POINT/dir1/file1" ]; then
+    echo "File 'file1' exists in dir1"
+else
+    echo "File 'file1' does not exist in dir1"
+fi
+
+if [ -e "$MOUNT_POINT/dir1/file2" ]; then
+    echo "File 'file2' exists in dir1"
+else
+    echo "File 'file2' does not exist in dir1"
+fi
+
+if [ -e "$MOUNT_POINT/dir2/file3" ]; then
+    echo "File 'file3' exists in dir2"
+else
+    echo "File 'file3' does not exist in dir2"
+fi
+
+# 显示调试日志
+echo "FUSE debug log:"
+kill -USR1 $FUSE_PID
+sleep 1  # 等待日志输出
+
+# 卸载 FUSE 文件系统
+echo "Unmounting FUSE filesystem..."
+sudo fusermount -u "$MOUNT_POINT"
+
+# 等待 FUSE 进程终止
+wait $FUSE_PID
+
+echo "All tests completed."