Support UTIME_OMIT/UTIME_NOW in futimens (#22459)

sbc100 · web-flow · commit e66809720748 · 2024-08-28T09:06:49.000-07:00
Fixes: #22348
diff --git a/src/library_syscall.js b/src/library_syscall.js
@@ -56,11 +56,11 @@ var SyscallsLibrary = {
       var mtime = stat.mtime.getTime();
       var ctime = stat.ctime.getTime();
       {{{ makeSetValue('buf', C_STRUCTS.stat.st_atim.tv_sec, 'Math.floor(atime / 1000)', 'i64') }}};
-      {{{ makeSetValue('buf', C_STRUCTS.stat.st_atim.tv_nsec, '(atime % 1000) * 1000', SIZE_TYPE) }}};
+      {{{ makeSetValue('buf', C_STRUCTS.stat.st_atim.tv_nsec, '(atime % 1000) * 1000 * 1000', SIZE_TYPE) }}};
       {{{ makeSetValue('buf', C_STRUCTS.stat.st_mtim.tv_sec, 'Math.floor(mtime / 1000)', 'i64') }}};
-      {{{ makeSetValue('buf', C_STRUCTS.stat.st_mtim.tv_nsec, '(mtime % 1000) * 1000', SIZE_TYPE) }}};
+      {{{ makeSetValue('buf', C_STRUCTS.stat.st_mtim.tv_nsec, '(mtime % 1000) * 1000 * 1000', SIZE_TYPE) }}};
       {{{ makeSetValue('buf', C_STRUCTS.stat.st_ctim.tv_sec, 'Math.floor(ctime / 1000)', 'i64') }}};
-      {{{ makeSetValue('buf', C_STRUCTS.stat.st_ctim.tv_nsec, '(ctime % 1000) * 1000', SIZE_TYPE) }}};
+      {{{ makeSetValue('buf', C_STRUCTS.stat.st_ctim.tv_nsec, '(ctime % 1000) * 1000 * 1000', SIZE_TYPE) }}};
       {{{ makeSetValue('buf', C_STRUCTS.stat.st_ino, 'stat.ino', 'i64') }}};
       return 0;
     },
@@ -978,19 +978,37 @@ var SyscallsLibrary = {
     assert(flags === 0);
 #endif
     path = SYSCALLS.calculateAt(dirfd, path, true);
+    var now = Date.now(), atime, mtime;
     if (!times) {
-      var atime = Date.now();
-      var mtime = atime;
+      atime = now;
+      mtime = now;
     } else {
       var seconds = {{{ makeGetValue('times', C_STRUCTS.timespec.tv_sec, 'i53') }}};
       var nanoseconds = {{{ makeGetValue('times', C_STRUCTS.timespec.tv_nsec, 'i32') }}};
-      atime = (seconds*1000) + (nanoseconds/(1000*1000));
+      if (nanoseconds == {{{ cDefs.UTIME_NOW }}}) {
+        atime = now;
+      } else if (nanoseconds == {{{ cDefs.UTIME_OMIT }}}) {
+        atime = -1;
+      } else {
+        atime = (seconds*1000) + (nanoseconds/(1000*1000));
+      }
       times += {{{ C_STRUCTS.timespec.__size__ }}};
       seconds = {{{ makeGetValue('times', C_STRUCTS.timespec.tv_sec, 'i53') }}};
       nanoseconds = {{{ makeGetValue('times', C_STRUCTS.timespec.tv_nsec, 'i32') }}};
-      mtime = (seconds*1000) + (nanoseconds/(1000*1000));
+      if (nanoseconds == {{{ cDefs.UTIME_NOW }}}) {
+        mtime = now;
+      } else if (nanoseconds == {{{ cDefs.UTIME_OMIT }}}) {
+        mtime = -1;
+      } else {
+        mtime = (seconds*1000) + (nanoseconds/(1000*1000));
+      }
+    }
+    // -1 here means UTIME_OMIT was passed.  FS.utime tables the max of these
+    // two values and sets the timestamp to that single value.  If both were
+    // set to UTIME_OMIT then we can skip the call completely.
+    if (mtime != -1 || atime != -1) {
+      FS.utime(path, atime, mtime);
     }
-    FS.utime(path, atime, mtime);
     return 0;
   },
   __syscall_fallocate__i53abi: true,
diff --git a/src/struct_info.json b/src/struct_info.json
@@ -33,7 +33,9 @@
             "S_IFCHR",
             "S_IRUSR",
             "S_IRGRP",
-            "S_IROTH"
+            "S_IROTH",
+            "UTIME_OMIT",
+            "UTIME_NOW"
         ],
         "structs": {
             "stat": [
diff --git a/src/struct_info_generated.json b/src/struct_info_generated.json
@@ -415,6 +415,8 @@
         "TIOCSPGRP": 21520,
         "TIOCSWINSZ": 21524,
         "TZNAME_MAX": 16,
+        "UTIME_NOW": 1073741823,
+        "UTIME_OMIT": 1073741822,
         "UUID_TYPE_DCE_RANDOM": 4,
         "UUID_VARIANT_DCE": 1,
         "W_OK": 2,
diff --git a/src/struct_info_generated_wasm64.json b/src/struct_info_generated_wasm64.json
@@ -415,6 +415,8 @@
         "TIOCSPGRP": 21520,
         "TIOCSWINSZ": 21524,
         "TZNAME_MAX": 16,
+        "UTIME_NOW": 1073741823,
+        "UTIME_OMIT": 1073741822,
         "UUID_TYPE_DCE_RANDOM": 4,
         "UUID_VARIANT_DCE": 1,
         "W_OK": 2,
diff --git a/system/lib/wasmfs/syscalls.cpp b/system/lib/wasmfs/syscalls.cpp
@@ -353,10 +353,6 @@ static timespec ms_to_timespec(double ms) {
   return ts;
 }
 
-static double timespec_to_ms(timespec ts) {
-  return double(ts.tv_sec) * 1000 + double(ts.tv_nsec) / (1000 * 1000);
-}
-
 int __syscall_newfstatat(int dirfd, intptr_t path, intptr_t buf, int flags) {
   // Only accept valid flags.
   if (flags & ~(AT_EMPTY_PATH | AT_NO_AUTOMOUNT | AT_SYMLINK_NOFOLLOW)) {
@@ -1123,6 +1119,16 @@ int __syscall_readlinkat(int dirfd,
   return bytes;
 }
 
+static double timespec_to_ms(timespec ts) {
+  if (ts.tv_nsec == UTIME_OMIT) {
+    return INFINITY;
+  }
+  if (ts.tv_nsec == UTIME_NOW) {
+    return emscripten_date_now();
+  }
+  return double(ts.tv_sec) * 1000 + double(ts.tv_nsec) / (1000 * 1000);
+}
+
 // TODO: Test this with non-AT_FDCWD values.
 int __syscall_utimensat(int dirFD, intptr_t path_, intptr_t times_, int flags) {
   const char* path = (const char*)path_;
@@ -1148,16 +1154,20 @@ int __syscall_utimensat(int dirFD, intptr_t path_, intptr_t times_, int flags) {
   // TODO: Check for write access to the file (see man page for specifics).
   double aTime, mTime;
 
-  if (times == NULL) {
+  if (times == nullptr) {
     aTime = mTime = emscripten_date_now();
   } else {
     aTime = timespec_to_ms(times[0]);
     mTime = timespec_to_ms(times[1]);
   }
 
   auto locked = parsed.getFile()->locked();
-  locked.setATime(aTime);
-  locked.setMTime(mTime);
+  if (aTime != INFINITY) {
+    locked.setATime(aTime);
+  }
+  if (mTime != INFINITY) {
+    locked.setMTime(mTime);
+  }
 
   return 0;
 }
diff --git a/test/test_core.py b/test/test_core.py
@@ -5654,6 +5654,7 @@ def test_libgen(self):
   def test_utime(self):
     self.do_runf('utime/test_utime.c', 'success')
 
+  @also_with_noderawfs
   def test_futimens(self):
     self.do_runf('utime/test_futimens.c', 'success')
 
diff --git a/test/utime/test_futimens.c b/test/utime/test_futimens.c
@@ -12,6 +12,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <time.h>
 #include <sys/stat.h>
 
 
@@ -31,6 +32,23 @@ void setup() {
   symlink("file", "folder/file-link");
 }
 
+void check_times(int fd, struct timespec* expected, int tolerance) {
+  struct stat s;
+  int rtn = fstatat(fd, "", &s, AT_EMPTY_PATH);
+  assert(rtn == 0);
+  printf("atime: tv_sec=%lld tv_nsec=%ld\n", s.st_atim.tv_sec, s.st_atim.tv_nsec);
+  printf("mtime: tv_sec=%lld tv_nsec=%ld\n", s.st_mtim.tv_sec, s.st_mtim.tv_nsec);
+  printf("expected atime: tv_sec=%lld tv_nsec=%ld\n", expected[0].tv_sec, expected[0].tv_nsec);
+  printf("expected mtime: tv_sec=%lld tv_nsec=%ld\n", expected[1].tv_sec, expected[1].tv_nsec);
+  if (tolerance) {
+    assert(llabs(expected[0].tv_sec - s.st_atim.tv_sec) <= tolerance);
+    assert(llabs(expected[1].tv_sec - s.st_mtim.tv_sec) <= tolerance);
+  } else {
+    assert(expected[0].tv_sec == s.st_atim.tv_sec);
+    assert(expected[1].tv_sec == s.st_mtim.tv_sec);
+  }
+}
+
 void test() {
   int err;
   struct stat s;
@@ -49,18 +67,72 @@ void test() {
   assert(s.st_rdev == 0);
   assert(s.st_size == 8);
   assert(s.st_ctime);
-#ifdef __EMSCRIPTEN__
+#if defined(__EMSCRIPTEN__) && !defined(NODERAWFS)
   assert(s.st_blksize == 4096);
   assert(s.st_blocks == 1);
 #endif
 
-  struct timespec origTimes[2];
-  origTimes[0].tv_sec = (time_t)s.st_atime;
-  origTimes[0].tv_nsec = origTimes[0].tv_sec * 1000;
-  origTimes[1].tv_sec = (time_t)s.st_mtime;
-  origTimes[1].tv_nsec = origTimes[1].tv_sec * 1000;
-  err = futimens(fd, origTimes);
+  struct timespec times[2];
+  times[0].tv_sec = s.st_atim.tv_sec;
+  times[0].tv_nsec = s.st_atim.tv_nsec;
+  times[1].tv_sec = s.st_mtim.tv_sec;
+  times[1].tv_nsec = s.st_mtim.tv_nsec;
+
+  // set the timestampe to the current value
+  err = futimens(fd, times);
+  assert(!err);
+  check_times(fd, times, 0);
+
+  // UTIME_OMIT means that the timeval is ignored, so
+  // this call should do nothing.
+  printf("check double UTIME_OMIT...\n");
+  struct timespec newtimes[2];
+  newtimes[0].tv_sec = 42;
+  newtimes[0].tv_nsec = UTIME_OMIT;
+  newtimes[1].tv_sec = 42;
+  newtimes[1].tv_nsec = UTIME_OMIT;
+  err = futimens(fd, newtimes);
+  assert(!err);
+  check_times(fd, times, 0);
+
+  // Setting just one of the two times to UTIME_OMIT means
+  // the other should be honored.
+  printf("check single UTIME_OMIT...\n");
+  newtimes[0].tv_sec = 41;
+  newtimes[0].tv_nsec = UTIME_OMIT;
+  newtimes[1].tv_sec = 42;
+  newtimes[1].tv_nsec = 88;
+  err = futimens(fd, newtimes);
+  assert(!err);
+
+#if defined(__EMSCRIPTEN__) && !defined(WASMFS) && !defined(NODERAWFS)
+  // The original emscripten FS (in JS) only supports a single timestamp so both
+  // mtime and atime will always be the same.
+  times[0].tv_sec = 42;
+  times[0].tv_nsec = 88;
+#endif
+  times[1].tv_sec = 42;
+  times[1].tv_nsec = 88;
+  check_times(fd, times, 0);
+
+  // UTIME_NOW means use the current date and ignore the seconds value
+  printf("check single UTIME_NOW...\n");
+  newtimes[0].tv_sec = 99;
+  newtimes[0].tv_nsec = UTIME_NOW;
+  newtimes[1].tv_sec = 99;
+  newtimes[1].tv_nsec = UTIME_NOW;
+  err = futimens(fd, newtimes);
+  assert(!err);
+
+  struct timespec now;
+  err = clock_gettime(CLOCK_REALTIME, &now);
+  printf("now: %lld %ld\n", now.tv_sec, now.tv_nsec);
   assert(!err);
+  times[0].tv_sec = now.tv_sec;
+  times[0].tv_nsec = now.tv_nsec;
+  times[1].tv_sec = now.tv_sec;
+  times[1].tv_nsec = now.tv_nsec;
+  check_times(fd, times, 1);
 
   close(fd);
 
