Cygwin: path_conv: simplify, rearrange, rename combined device checks

Some checks in path_conv are checking for various properties to generate a boolean value, mostly to indicate different combinations of on-disk files and devices. Simplify these checks and, especially, document them inline. Drop the isdevice() check in favor of a new isondisk() check. Fixes: 4fc922b ("Cygwin: POSIX msg queues: Convert mqd_t to a descriptor") Signed-off-by: Corinna Vinschen <[email protected]>
dscho · Jan 21, 2025 · 890086a · 890086a
1 parent d870655
commit 890086a
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Showing 3 changed files with 21 additions and 10 deletions.
diff --git a/winsup/cygwin/local_includes/path.h b/winsup/cygwin/local_includes/path.h
@@ -214,21 +214,33 @@ class path_conv
   {
     return (path_flags & (PATH_REP | PATH_REP_NOAPI)) == PATH_REP;
   }
-  int isdevice () const {return dev.not_device (FH_FS) && dev.not_device (FH_FIFO);}
+
   int isfifo () const {return dev.is_device (FH_FIFO);}
-  int isspecial () const {return dev.not_device (FH_FS);}
   int iscygdrive () const {return dev.is_device (FH_CYGDRIVE);}
-  int is_fs_special () const {return dev.is_fs_special ();}
-
-  int is_lnk_special () const {return (isdevice () && is_fs_special ()
-				       && !issocket ())
-      || isfifo () || is_lnk_symlink ();}
 #ifdef __WITH_AF_UNIX
   int issocket () const {return dev.is_device (FH_LOCAL)
 				|| dev.is_device (FH_UNIX);}
 #else
   int issocket () const {return dev.is_device (FH_LOCAL);}
 #endif /* __WITH_AF_UNIX */
+
+  /* FIXME: This needs a cleanup with better, descriptive names and checking
+     all usages for correctness. */
+
+  /* Any file or device with representation on disk.  This includes local
+     sockets, FIFOs, message queues and devices created with mknod.  It does
+     not include the /proc hierarchy. */
+  int isondisk () const {return dev.isfs ();}
+  /* Any device, virtual or with on-disk representation, and anything under
+     /proc. */
+  int isspecial () const {return dev.not_device (FH_FS);}
+  /* Devices with representation on disk. This includes local sockets, FIFOs,
+     message queues and devices created with mknod.  It does not include
+     the /proc hierarchy. */
+  int is_fs_special () const {return dev.is_fs_special ();}
+  /* Like is_fs_special but excluding local sockets. */
+  int is_lnk_special () const {return is_fs_special () && !issocket ();}
+
   int iscygexec () const {return mount_flags & MOUNT_CYGWIN_EXEC;}
   int isopen () const {return path_flags & PATH_OPEN;}
   int isctty_capable () const {return path_flags & PATH_CTTY;}

diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
@@ -2080,8 +2080,7 @@ symlink_worker (const char *oldpath, path_conv &win32_newpath, bool isdevice)
       syscall_printf ("symlink (%s, %S) wsym_type %d", oldpath,
 		      win32_newpath.get_nt_native_path (), wsym_type);
 
-      if ((!isdevice && win32_newpath.exists ())
-	  || (win32_newpath.isdevice () && !win32_newpath.is_fs_special ()))
+      if (win32_newpath.exists() && (!isdevice || !win32_newpath.isondisk ()))
 	{
 	  set_errno (EEXIST);
 	  __leave;

diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc
@@ -1136,7 +1136,7 @@ unlink (const char *ourname)
       set_errno (EROFS);
       goto done;
     }
-  if (isdevfd_dev (devn) || (win32_name.isdevice () && !win32_name.issocket ()))
+  if (!win32_name.isondisk ())
     {
       set_errno (EPERM);
       goto done;