wasi: fs time precision option (#7569)

* wasi: test for mtime accuracy to 1ms only

* add accurate time configuration

* fix conditional

* extend mtime accuracy cases

* remove unnecessary diff

* more cases

* reworking

* u64 tweak

* use direct precision checks in assertions

crates/test-programs/src/bin/preview1_fd_filestat_set.rs

@@ -1,7 +1,8 @@
-use std::{env, process};
-use test_programs::preview1::open_scratch_directory;
+use std::{env, process, time::Duration};
+use test_programs::preview1::{assert_fs_time_eq, open_scratch_directory, TestConfig};
 
 unsafe fn test_fd_filestat_set(dir_fd: wasi::Fd) {
+    let cfg = TestConfig::from_env();
     // Create a file in the scratch directory.
     let file_fd = wasi::path_open(
         dir_fd,
@@ -29,15 +30,30 @@ unsafe fn test_fd_filestat_set(dir_fd: wasi::Fd) {
     assert_eq!(stat.size, 100, "file size should be 100");
 
     // Check fd_filestat_set_times
-    let old_atim = stat.atim;
-    let new_mtim = stat.mtim - 100;
-    wasi::fd_filestat_set_times(file_fd, new_mtim, new_mtim, wasi::FSTFLAGS_MTIM)
-        .expect("fd_filestat_set_times");
+    let old_atim = Duration::from_nanos(stat.atim);
+    let new_mtim = Duration::from_nanos(stat.mtim) - cfg.fs_time_precision() * 2;
+    wasi::fd_filestat_set_times(
+        file_fd,
+        new_mtim.as_nanos() as u64,
+        new_mtim.as_nanos() as u64,
+        wasi::FSTFLAGS_MTIM,
+    )
+    .expect("fd_filestat_set_times");
 
     let stat = wasi::fd_filestat_get(file_fd).expect("failed filestat 3");
     assert_eq!(stat.size, 100, "file size should remain unchanged at 100");
-    assert_eq!(stat.mtim, new_mtim, "mtim should change");
-    assert_eq!(stat.atim, old_atim, "atim should not change");
+
+    // Support accuracy up to at least 1ms
+    assert_fs_time_eq!(
+        Duration::from_nanos(stat.mtim),
+        new_mtim,
+        "mtim should change"
+    );
+    assert_fs_time_eq!(
+        Duration::from_nanos(stat.atim),
+        old_atim,
+        "atim should not change"
+    );
 
     // let status = wasi_fd_filestat_set_times(file_fd, new_mtim, new_mtim, wasi::FILESTAT_SET_MTIM | wasi::FILESTAT_SET_MTIM_NOW);
     // assert_eq!(status, wasi::EINVAL, "ATIM & ATIM_NOW can't both be set");

crates/test-programs/src/bin/preview1_path_filestat.rs

@@ -1,7 +1,10 @@
-use std::{env, process};
-use test_programs::preview1::{assert_errno, config, open_scratch_directory};
+use std::{env, process, time::Duration};
+use test_programs::preview1::{
+    assert_errno, assert_fs_time_eq, config, open_scratch_directory, TestConfig,
+};
 
 unsafe fn test_path_filestat(dir_fd: wasi::Fd) {
+    let cfg = TestConfig::from_env();
     let fdflags = if config().support_fdflags_sync() {
         wasi::FDFLAGS_APPEND | wasi::FDFLAGS_SYNC
     } else {
@@ -60,13 +63,25 @@ unsafe fn test_path_filestat(dir_fd: wasi::Fd) {
     assert_eq!(file_stat.size, 0, "file size should be 0");
 
     // Check path_filestat_set_times
-    let new_mtim = file_stat.mtim - 100;
-    wasi::path_filestat_set_times(dir_fd, 0, "file", 0, new_mtim, wasi::FSTFLAGS_MTIM)
-        .expect("path_filestat_set_times should succeed");
+    let new_mtim = Duration::from_nanos(file_stat.mtim) - 2 * cfg.fs_time_precision();
+    wasi::path_filestat_set_times(
+        dir_fd,
+        0,
+        "file",
+        0,
+        new_mtim.as_nanos() as u64,
+        wasi::FSTFLAGS_MTIM,
+    )
+    .expect("path_filestat_set_times should succeed");
 
     let modified_file_stat = wasi::path_filestat_get(dir_fd, 0, "file")
         .expect("reading file stats after path_filestat_set_times");
-    assert_eq!(modified_file_stat.mtim, new_mtim, "mtim should change");
+
+    assert_fs_time_eq!(
+        Duration::from_nanos(modified_file_stat.mtim),
+        new_mtim,
+        "mtim should change"
+    );
 
     assert_errno!(
         wasi::path_filestat_set_times(
@@ -74,7 +89,7 @@ unsafe fn test_path_filestat(dir_fd: wasi::Fd) {
             0,
             "file",
             0,
-            new_mtim,
+            new_mtim.as_nanos() as u64,
             wasi::FSTFLAGS_MTIM | wasi::FSTFLAGS_MTIM_NOW,
         )
         .expect_err("MTIM and MTIM_NOW can't both be set"),
@@ -84,8 +99,10 @@ unsafe fn test_path_filestat(dir_fd: wasi::Fd) {
     // check if the times were untouched
     let unmodified_file_stat = wasi::path_filestat_get(dir_fd, 0, "file")
         .expect("reading file stats after ERRNO_INVAL fd_filestat_set_times");
-    assert_eq!(
-        unmodified_file_stat.mtim, new_mtim,
+
+    assert_fs_time_eq!(
+        Duration::from_nanos(unmodified_file_stat.mtim),
+        new_mtim,
         "mtim should not change"
     );
 

crates/test-programs/src/bin/preview1_symlink_filestat.rs

@@ -1,7 +1,8 @@
-use std::{env, process};
-use test_programs::preview1::open_scratch_directory;
+use std::{env, process, time::Duration};
+use test_programs::preview1::{assert_fs_time_eq, open_scratch_directory, TestConfig};
 
 unsafe fn test_path_filestat(dir_fd: wasi::Fd) {
+    let cfg = TestConfig::from_env();
     // Create a file in the scratch directory.
     let file_fd = wasi::path_open(
         dir_fd,
@@ -29,21 +30,31 @@ unsafe fn test_path_filestat(dir_fd: wasi::Fd) {
     let sym_stat = wasi::path_filestat_get(dir_fd, 0, "symlink").expect("reading symlink stats");
 
     // Modify mtim of symlink
-    let sym_new_mtim = sym_stat.mtim - 200;
-    wasi::path_filestat_set_times(dir_fd, 0, "symlink", 0, sym_new_mtim, wasi::FSTFLAGS_MTIM)
-        .expect("path_filestat_set_times should succeed on symlink");
+    let sym_new_mtim = Duration::from_nanos(sym_stat.mtim) - cfg.fs_time_precision() * 2;
+    wasi::path_filestat_set_times(
+        dir_fd,
+        0,
+        "symlink",
+        0,
+        sym_new_mtim.as_nanos() as u64,
+        wasi::FSTFLAGS_MTIM,
+    )
+    .expect("path_filestat_set_times should succeed on symlink");
 
     // Check that symlink mtim motification worked
     let modified_sym_stat = wasi::path_filestat_get(dir_fd, 0, "symlink")
         .expect("reading file stats after path_filestat_set_times");
-    assert_eq!(
-        modified_sym_stat.mtim, sym_new_mtim,
+
+    assert_fs_time_eq!(
+        Duration::from_nanos(modified_sym_stat.mtim),
+        sym_new_mtim,
         "symlink mtim should change"
     );
 
     // Check that pointee mtim is not modified
     let unmodified_file_stat = wasi::path_filestat_get(dir_fd, 0, "file")
         .expect("reading file stats after path_filestat_set_times");
+
     assert_eq!(
         unmodified_file_stat.mtim, file_stat.mtim,
         "file mtim should not change"
@@ -71,7 +82,12 @@ unsafe fn test_path_filestat(dir_fd: wasi::Fd) {
 
     let new_file_stat = wasi::path_filestat_get(dir_fd, 0, "file")
         .expect("reading file stats after path_filestat_set_times");
-    assert_eq!(new_file_stat.mtim, sym_stat.mtim, "mtim should change");
+
+    assert_fs_time_eq!(
+        Duration::from_nanos(new_file_stat.mtim),
+        Duration::from_nanos(sym_stat.mtim),
+        "mtim should change"
+    );
 
     wasi::fd_close(file_fd).expect("closing a file");
     wasi::path_unlink_file(dir_fd, "symlink").expect("removing a symlink");

crates/test-programs/src/preview1.rs

@@ -1,4 +1,4 @@
-use std::sync::OnceLock;
+use std::{sync::OnceLock, time::Duration};
 
 pub fn config() -> &'static TestConfig {
     static TESTCONFIG: OnceLock<TestConfig> = OnceLock::new();
@@ -45,9 +45,9 @@ pub unsafe fn create_file(dir_fd: wasi::Fd, filename: &str) {
     wasi::fd_close(file_fd).expect("closing a file");
 }
 
-// Small workaround to get the crate's `assert_errno`, through the
+// Small workaround to get the crate's macros, through the
 // `#[macro_export]` attribute below, also available from this module.
-pub use crate::assert_errno;
+pub use crate::{assert_errno, assert_fs_time_eq};
 
 #[macro_export]
 macro_rules! assert_errno {
@@ -114,8 +114,17 @@ macro_rules! assert_errno {
     };
 }
 
+#[macro_export]
+macro_rules! assert_fs_time_eq {
+    ($l:expr, $r:expr, $n:literal) => {
+        let diff = if $l > $r { $l - $r } else { $r - $l };
+        assert!(diff < $crate::preview1::config().fs_time_precision(), $n);
+    };
+}
+
 pub struct TestConfig {
     errno_mode: ErrnoMode,
+    fs_time_precision: u64,
     no_dangling_filesystem: bool,
     no_rename_dir_to_empty_dir: bool,
     no_fdflags_sync_support: bool,
@@ -139,11 +148,16 @@ impl TestConfig {
         } else {
             ErrnoMode::Permissive
         };
+        let fs_time_precision = match std::env::var("FS_TIME_PRECISION") {
+            Ok(p) => p.parse().unwrap(),
+            Err(_) => 100,
+        };
         let no_dangling_filesystem = std::env::var("NO_DANGLING_FILESYSTEM").is_ok();
         let no_rename_dir_to_empty_dir = std::env::var("NO_RENAME_DIR_TO_EMPTY_DIR").is_ok();
         let no_fdflags_sync_support = std::env::var("NO_FDFLAGS_SYNC_SUPPORT").is_ok();
         TestConfig {
             errno_mode,
+            fs_time_precision,
             no_dangling_filesystem,
             no_rename_dir_to_empty_dir,
             no_fdflags_sync_support,
@@ -167,6 +181,9 @@ impl TestConfig {
             _ => false,
         }
     }
+    pub fn fs_time_precision(&self) -> Duration {
+        Duration::from_nanos(self.fs_time_precision)
+    }
     pub fn support_dangling_filesystem(&self) -> bool {
         !self.no_dangling_filesystem
     }