Error file size ?

[orangeC23]

Steps to reproduce

(1)The c file is :

#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/uio.h>
#include <string.h>
#include <sys/stat.h>

int main() {
    const char* file_name = "Data/hello.txt";
    int open_style= O_WRONLY | O_CREAT;
    int fd = get_fd(file_name, open_style);
    fd_pwrite7FAS6BAKLT(fd);
    snapshot(fd);
    return 0;
}

int fd_pwrite7FAS6BAKLT(int fd) {
    char buffer1[] = "xJ4lgHSgN50d";
    off_t offset_value = 0;
    int start_value = 129;
    return fd_pwrite(fd, buffer1, offset_value, start_value);
}

int get_fd(const char* file_name, int open_style){
    int fd = open(file_name, open_style);
    if (fd == -1) {
        perror("Failed to open the file");
        return 1;
    }

    return fd;
}

int fd_pwrite(int fd, char buffer1[], off_t offset_value, int start_value) {
    printf("Enter fd_pwrite\n");

    struct iovec iov[1];
    iov[0].iov_base = buffer1;
    iov[0].iov_len = strlen(buffer1);

    off_t new_offset = offset_value;

    if (lseek(fd, new_offset, SEEK_SET) == -1) {
        perror("Error setting new offset");
        close(fd);
        return 1;
    }

    off_t current_offset = lseek(fd, 0, SEEK_CUR);
    if (current_offset == -1) {
        perror("Error getting current offset");
    }
    printf("Current offset: %lld\n", (long long)current_offset);

    off_t offset = start_value;
    ssize_t bytes_written = pwritev(fd, iov, 1, offset);
    if (bytes_written == -1) {
        perror("Error writing to the file");
        close(fd);
        return 1;
    }

    printf("Wrote %zd bytes to the file.\n", bytes_written);

    printf("Leave fd_pwrite\n");
    return fd;
}

int snapshot(int myfd){   
    printf("Enter snapshot\n");

    struct stat file_info;
    if (fstat(myfd, &file_info) == -1) {
        perror("Error getting file attributes");
        close(myfd);
        return 1;
    }

    printf("File Size: %lld bytes \n", (long long)file_info.st_size);

    off_t cur_offset = lseek(myfd, 0, SEEK_CUR);
    if (cur_offset == -1) {
        perror("Error getting current offset");
    }
    printf("Current offset: %lld \n", (long long)cur_offset);

    if (close(myfd) == -1) {
        perror("Error closing file");
        return 1;
    }

    printf("Leave snapshot\n");
}

(2) compile the c file into wasm: ./wasi-sdk-16.0/bin/clang --target=wasm32-unkown-wasi --sysroot=./wasi-sdk-16.0/share/wasi-sysroot test.c -o test.wasm (3)exeute open.wasm wasmer run --dir=./Data test.wasm The permission of Data/hello.txt is 0700, user1 create the Data/hello.txt file and user1 execute the Wasm file.

Expected behavior

wasmtime, wazero, wamr, wasmedge print:

Enter fd_pwrite
Current offset: 0
Wrote 12 bytes to the file.
Leave fd_pwrite
Enter snapshot
File Size: 141 bytes 
Current offset: 0 
Leave snapshot

And using ls -al ./Data/hello.txt to check the file size is 141.

Actual behavior

wasmer prints:

Enter fd_pwrite
Current offset: 0
Wrote 12 bytes to the file.
Leave fd_pwrite
Enter snapshot
File Size: 42 bytes 
Current offset: 0 
Leave snapshot

And using ls -al ./Data/hello.txt to check the file size is 141. This is different from the printing value 42. Maybe this is a bug?

version

wasmer 4.2.2

ubuntu 20.04

[Arshia001]

probably related to #4259, #4265 and #4270.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.