[PATCH v2 6/8] syscalls.cc: Expose shallow-pathconv unlink_nt

[Ben Wijen]

Not having to query file information improves unlink speed.
---
 winsup/cygwin/syscalls.cc | 78 ++++++++++++++++++++++++++-------------
 1 file changed, 52 insertions(+), 26 deletions(-)

diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc
index ab0c4c2d6..b5ab6ac5e 100644
--- a/winsup/cygwin/syscalls.cc
+++ b/winsup/cygwin/syscalls.cc
@@ -1272,6 +1272,28 @@ _unlink_ntpc_ (path_conv& pc, bool shareable)
   return status;
 }
 
+NTSTATUS
+unlink_nt (const char *ourname, ULONG eflags)
+{
+  uint32_t opt = PC_SYM_NOFOLLOW | PC_SKIP_SYM_CHECK | PC_SKIP_FS_CHECK;
+  if (!(eflags & FILE_NON_DIRECTORY_FILE))
+    opt &= ~PC_SKIP_FS_CHECK;
+
+  path_conv pc (ourname, opt, NULL);
+  if (pc.error || pc.isspecial ())
+    return STATUS_CANNOT_DELETE;
+
+  OBJECT_ATTRIBUTES attr;
+  PUNICODE_STRING ntpath = pc.get_nt_native_path ();
+  InitializeObjectAttributes(&attr, ntpath, 0, NULL, NULL);
+  NTSTATUS status = _unlink_nt (&attr, eflags);
+
+  if (!(eflags & FILE_NON_DIRECTORY_FILE))
+    status = _unlink_nt_post_dir_check (status, &attr, pc);
+
+  return status;
+}
+
 NTSTATUS
 unlink_ntpc (path_conv &pc)
 {
@@ -1289,37 +1311,41 @@ unlink (const char *ourname)
 {
   int res = -1;
   dev_t devn;
-  NTSTATUS status;
+  NTSTATUS status = unlink_nt (ourname, FILE_NON_DIRECTORY_FILE);
 
-  path_conv win32_name (ourname, PC_SYM_NOFOLLOW, stat_suffixes);
+  if (!NT_SUCCESS (status))
+  {
+    path_conv win32_name (ourname, PC_SYM_NOFOLLOW, stat_suffixes);
 
-  if (win32_name.error)
-    {
-      set_errno (win32_name.error);
-      goto done;
-    }
+    if (win32_name.error)
+      {
+        set_errno (win32_name.error);
+        goto done;
+      }
 
-  devn = win32_name.get_device ();
-  if (isproc_dev (devn))
-    {
-      set_errno (EROFS);
-      goto done;
-    }
+    devn = win32_name.get_device ();
+    if (isproc_dev (devn))
+      {
+        set_errno (EROFS);
+        goto done;
+      }
 
-  if (!win32_name.exists ())
-    {
-      debug_printf ("unlinking a nonexistent file");
-      set_errno (ENOENT);
-      goto done;
-    }
-  else if (win32_name.isdir ())
-    {
-      debug_printf ("unlinking a directory");
-      set_errno (EISDIR);
-      goto done;
-    }
+    if (!win32_name.exists ())
+      {
+        debug_printf ("unlinking a nonexistent file");
+        set_errno (ENOENT);
+        goto done;
+      }
+    else if (win32_name.isdir ())
+      {
+        debug_printf ("unlinking a directory");
+        set_errno (EISDIR);
+        goto done;
+      }
+
+    status = unlink_ntpc (win32_name);
+  }
 
-  status = unlink_ntpc (win32_name);
   if (NT_SUCCESS (status))
     res = 0;
   else
-- 
2.30.0