Add support for the sync and fsync syscall

services/libs/aster-std/src/fs/utils/dentry.rs

@@ -383,6 +383,11 @@ impl Dentry {
         self.inode.fs()
     }
 
+    /// Flushes all changes made to data and metadata to the device.
+    pub fn sync(&self) -> Result<()> {
+        self.inode.sync()
+    }
+
     /// Get the inode metadata
     pub fn inode_metadata(&self) -> Metadata {
         self.inode.metadata()

services/libs/aster-std/src/fs/utils/mount.rs

@@ -101,6 +101,18 @@ impl MountNode {
         self.mountpoint_dentry.as_ref()
     }
 
+    /// Flushes all pending filesystem metadata and cached file data to the device.
+    pub fn sync(&self) -> Result<()> {
+        let children = self.children.lock();
+        for child in children.values() {
+            child.sync()?;
+        }
+        drop(children);
+
+        self.fs.sync()?;
+        Ok(())
+    }
+
     /// Try to get the parent mount node.
     pub fn parent(&self) -> Option<Arc<Self>> {
         self.mountpoint_dentry

services/libs/aster-std/src/syscall/fsync.rs

@@ -0,0 +1,25 @@
+use crate::log_syscall_entry;
+use crate::{
+    fs::{file_table::FileDescripter, inode_handle::InodeHandle},
+    prelude::*,
+};
+
+use super::SyscallReturn;
+use super::SYS_FSYNC;
+
+pub fn sys_fsync(fd: FileDescripter) -> Result<SyscallReturn> {
+    log_syscall_entry!(SYS_FSYNC);
+    debug!("fd = {}", fd);
+
+    let dentry = {
+        let current = current!();
+        let file_table = current.file_table().lock();
+        let file = file_table.get_file(fd)?;
+        let inode_handle = file
+            .downcast_ref::<InodeHandle>()
+            .ok_or(Error::with_message(Errno::EINVAL, "not inode"))?;
+        inode_handle.dentry().clone()
+    };
+    dentry.sync()?;
+    Ok(SyscallReturn::Return(0))
+}

services/libs/aster-std/src/syscall/mod.rs

@@ -17,6 +17,7 @@ use crate::syscall::exit::sys_exit;
 use crate::syscall::exit_group::sys_exit_group;
 use crate::syscall::fcntl::sys_fcntl;
 use crate::syscall::fork::sys_fork;
+use crate::syscall::fsync::sys_fsync;
 use crate::syscall::futex::sys_futex;
 use crate::syscall::getcwd::sys_getcwd;
 use crate::syscall::getdents64::sys_getdents64;
@@ -59,6 +60,7 @@ use crate::syscall::setpgid::sys_setpgid;
 use crate::syscall::stat::{sys_fstat, sys_fstatat, sys_lstat, sys_stat};
 use crate::syscall::statfs::{sys_fstatfs, sys_statfs};
 use crate::syscall::symlink::{sys_symlink, sys_symlinkat};
+use crate::syscall::sync::sys_sync;
 use crate::syscall::tgkill::sys_tgkill;
 use crate::syscall::time::sys_time;
 use crate::syscall::umask::sys_umask;
@@ -123,6 +125,7 @@ mod exit;
 mod exit_group;
 mod fcntl;
 mod fork;
+mod fsync;
 mod futex;
 mod getcwd;
 mod getdents64;
@@ -192,6 +195,7 @@ mod socketpair;
 mod stat;
 mod statfs;
 mod symlink;
+mod sync;
 mod tgkill;
 mod time;
 mod umask;
@@ -283,6 +287,7 @@ define_syscall_nums!(
     SYS_KILL = 62,
     SYS_UNAME = 63,
     SYS_FCNTL = 72,
+    SYS_FSYNC = 74,
     SYS_GETCWD = 79,
     SYS_CHDIR = 80,
     SYS_FCHDIR = 81,
@@ -323,6 +328,7 @@ define_syscall_nums!(
     SYS_FSTATFS = 138,
     SYS_PRCTL = 157,
     SYS_ARCH_PRCTL = 158,
+    SYS_SYNC = 162,
     SYS_GETTID = 186,
     SYS_TIME = 201,
     SYS_FUTEX = 202,
@@ -459,6 +465,7 @@ pub fn syscall_dispatch(
         SYS_KILL => syscall_handler!(2, sys_kill, args),
         SYS_UNAME => syscall_handler!(1, sys_uname, args),
         SYS_FCNTL => syscall_handler!(3, sys_fcntl, args),
+        SYS_FSYNC => syscall_handler!(1, sys_fsync, args),
         SYS_GETCWD => syscall_handler!(2, sys_getcwd, args),
         SYS_CHDIR => syscall_handler!(1, sys_chdir, args),
         SYS_FCHDIR => syscall_handler!(1, sys_fchdir, args),
@@ -499,6 +506,7 @@ pub fn syscall_dispatch(
         SYS_FSTATFS => syscall_handler!(2, sys_fstatfs, args),
         SYS_PRCTL => syscall_handler!(5, sys_prctl, args),
         SYS_ARCH_PRCTL => syscall_handler!(2, sys_arch_prctl, args, context),
+        SYS_SYNC => syscall_handler!(0, sys_sync),
         SYS_GETTID => syscall_handler!(0, sys_gettid),
         SYS_TIME => syscall_handler!(1, sys_time, args),
         SYS_FUTEX => syscall_handler!(6, sys_futex, args),

services/libs/aster-std/src/syscall/sync.rs

@@ -0,0 +1,12 @@
+use crate::log_syscall_entry;
+use crate::prelude::*;
+
+use super::SyscallReturn;
+use super::SYS_SYNC;
+
+pub fn sys_sync() -> Result<SyscallReturn> {
+    log_syscall_entry!(SYS_SYNC);
+
+    crate::fs::rootfs::root_mount().sync()?;
+    Ok(SyscallReturn::Return(0))
+}