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Fix getdents cannot output all entries in a directory

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LI Qing 2021-02-19 11:42:56 +08:00 committed by Zongmin.Gu
parent c4c3315c06
commit d7b994bc7d
2 changed files with 93 additions and 15 deletions
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67
src/libos/src/fs/file_ops/dirent.rs
View File

@ -8,7 +8,7 @@ pub fn do_getdents(fd: FileDesc, buf: &mut [u8]) -> Result<usize> {
getdents_common::<()>(fd, buf)
}
fn getdents_common<T: DirentType + Copy + Default>(fd: FileDesc, buf: &mut [u8]) -> Result<usize> {
fn getdents_common<T: DirentType + Copy>(fd: FileDesc, buf: &mut [u8]) -> Result<usize> {
debug!(
"getdents: fd: {}, buf: {:?}, buf_size: {}",
fd,
@ -33,8 +33,8 @@ fn getdents_common<T: DirentType + Copy + Default>(fd: FileDesc, buf: &mut [u8])
}
Ok(name) => name,
};
// TODO: get ino from dirent
let dirent = LinuxDirent::<T>::new(1, &name);
// TODO: get ino and type from dirent
let dirent = LinuxDirent::<T>::new(1, &name, DT_UNKNOWN);
if let Err(e) = writer.try_write(&dirent, &name) {
file_ref.seek(SeekFrom::Current(-1))?;
if writer.written_size == 0 {
@ -47,8 +47,10 @@ fn getdents_common<T: DirentType + Copy + Default>(fd: FileDesc, buf: &mut [u8])
Ok(writer.written_size)
}
const DT_UNKNOWN: u8 = 0;
#[repr(packed)] // Don't use 'C'. Or its size will align up to 8 bytes.
struct LinuxDirent<T: DirentType + Copy + Default> {
struct LinuxDirent<T: DirentType + Copy> {
/// Inode number
ino: u64,
/// Offset to next structure
@ -61,15 +63,20 @@ struct LinuxDirent<T: DirentType + Copy + Default> {
name: [u8; 0],
}
impl<T: DirentType + Copy + Default> LinuxDirent<T> {
fn new(ino: u64, name: &str) -> Self {
let ori_len = ::core::mem::size_of::<LinuxDirent<T>>() + name.len() + 1;
impl<T: DirentType + Copy> LinuxDirent<T> {
fn new(ino: u64, name: &str, d_type: u8) -> Self {
let ori_len = if !T::at_the_end_of_linux_dirent() {
core::mem::size_of::<LinuxDirent<T>>() + name.len() + 1
} else {
// pad the file type at the end
core::mem::size_of::<LinuxDirent<T>>() + name.len() + 1 + core::mem::size_of::<u8>()
};
let len = align_up(ori_len, 8); // align up to 8 bytes
Self {
ino,
offset: 0,
reclen: len as u16,
type_: Default::default(),
type_: T::set_type(d_type),
name: [],
}
}
@ -79,9 +86,9 @@ impl<T: DirentType + Copy + Default> LinuxDirent<T> {
}
}
impl<T: DirentType + Copy + Default> Copy for LinuxDirent<T> {}
impl<T: DirentType + Copy> Copy for LinuxDirent<T> {}
impl<T: DirentType + Copy + Default> Clone for LinuxDirent<T> {
impl<T: DirentType + Copy> Clone for LinuxDirent<T> {
fn clone(&self) -> Self {
Self {
ino: self.ino,
@ -93,10 +100,27 @@ impl<T: DirentType + Copy + Default> Clone for LinuxDirent<T> {
}
}
trait DirentType {}
trait DirentType {
fn set_type(d_type: u8) -> Self;
fn at_the_end_of_linux_dirent() -> bool;
}
impl DirentType for u8 {}
impl DirentType for () {}
impl DirentType for u8 {
fn set_type(d_type: u8) -> Self {
d_type
}
fn at_the_end_of_linux_dirent() -> bool {
false
}
}
impl DirentType for () {
fn set_type(d_type: u8) -> Self {
Default::default()
}
fn at_the_end_of_linux_dirent() -> bool {
true
}
}
struct DirentBufWriter<'a> {
buf: &'a mut [u8],
@ -114,7 +138,7 @@ impl<'a> DirentBufWriter<'a> {
}
}
fn try_write<T: DirentType + Copy + Default>(
fn try_write<T: DirentType + Copy>(
&mut self,
dirent: &LinuxDirent<T>,
name: &str,
@ -127,6 +151,21 @@ impl<'a> DirentBufWriter<'a> {
ptr.write(*dirent);
let name_ptr = ptr.add(1) as _;
write_cstr(name_ptr, name);
if T::at_the_end_of_linux_dirent() {
// pad zero bytes and file type at the end
let mut ptr = name_ptr.add(name.len() + 1);
let mut rest_len = {
let written_len = core::mem::size_of::<LinuxDirent<T>>() + name.len() + 1;
dirent.len() - written_len
};
while rest_len > 1 {
ptr.write(0);
ptr = ptr.add(1);
rest_len -= 1;
}
// the last one is file type
ptr.write(DT_UNKNOWN);
}
}
self.rest_size -= dirent.len();
self.written_size += dirent.len();

41
test/readdir/main.c
View File

@ -7,6 +7,38 @@
#include <fcntl.h>
#include "test_fs.h"
// ============================================================================
// Helper function
// ============================================================================
#define NUM 9
static bool check_dir_entries(char entries[][256], int entry_cnt) {
char *expected_entries[NUM] = {
"bin",
"dev",
"host",
"lib",
"lib64",
"proc",
"opt",
"root",
"tmp",
};
for (int i = 0; i < NUM; i++) {
bool find_entry = false;
for (int j = 0; j < entry_cnt; j++) {
if (strncmp(expected_entries[i], entries[j], strlen(expected_entries[i])) == 0) {
find_entry = true;
break;
}
}
if (!find_entry) {
return false;
}
}
return true;
}
// ============================================================================
// The test case of readdir
// ============================================================================
@ -14,21 +46,28 @@
static int test_readdir() {
struct dirent *dp;
DIR *dirp;
char entries[32][256] = { 0 };
dirp = opendir("/");
if (dirp == NULL) {
THROW_ERROR("failed to open directory");
}
int entry_cnt = 0;
while (1) {
errno = 0;
dp = readdir(dirp);
if (dp == NULL) {
if (errno != 0) {
closedir(dirp);
THROW_ERROR("faild to call readdir");
THROW_ERROR("failed to call readdir");
}
break;
}
strncpy(entries[entry_cnt], dp->d_name, 256);
++entry_cnt;
}
if (!check_dir_entries(entries, entry_cnt)) {
THROW_ERROR("failed to check the result of readdir");
}
closedir(dirp);
return 0;