Re: [PATCH.HURD] fix fdatasync/fsync if file_sync is not supported

[Pino Toscano <toscano dot pino at tiscali dot it>]

Alle giovedì 25 ottobre 2012, Roland McGrath ha scritto:
> We don't generally handle MIG_BAD_ID.  That error indicates a server
> not implementing the protocol for which it's being used, which is a
> server bug. If anything, we'd translate that to EGRATUITOUS in the
> general case, and perhaps to EOPNOTSUPP in particular cases where
> it's not an ironclad part of the interface contract that it
> implement the particular protocol.  So I think we should separate
> the MIG_BAD_ID case and treat it more generally, if at all.

OK, it seems it could actually be a bug in pflocal, sorry for the bad 
investigation of thi.s

> Since it's the norm for servers to return EOPNOTSUPP for
> miscellaneous RPCs they aren't implementing, translating that to
> EINVAL for fsync/fdatasync is reasonable.  It should have a comment
> saying that POSIX.1 specifies EINVAL for a file descriptor on which
> sync is not supported.

Attached an updated patch to handle only EOPNOTSUPP, with comment added.

Thanks,
-- 
Pino Toscano

Hurd: fix fdatasync/fsync if the fd does not support file_sync

Handle the case of the fd port implementing a stub (EOPNOTSUPP),
properly returning EINVAL.

2012-10-29  Pino Toscano  <toscano.pino@tiscali.it>

	* sysdeps/mach/hurd/fdatasync.c: Turn ERR into EINVAL if it is
	EOPNOTSUPP.
	* sysdeps/mach/hurd/fsync.c: Likewise.
--- a/sysdeps/mach/hurd/fdatasync.c
+++ b/sysdeps/mach/hurd/fdatasync.c
@@ -26,6 +26,12 @@ fdatasync (int fd)
 {
   error_t err = HURD_DPORT_USE (fd, __file_sync (port, 1, 1));
   if (err)
-    return __hurd_dfail (fd, err);
+    {
+      if (err == EOPNOTSUPP)
+	/* If the file descriptor does not support sync, return EINVAL
+	   as POSIX specifies.  */
+	err = EINVAL;
+      return __hurd_dfail (fd, err);
+    }
   return 0;
 }
--- a/sysdeps/mach/hurd/fsync.c
+++ b/sysdeps/mach/hurd/fsync.c
@@ -27,6 +27,12 @@ fsync (fd)
 {
   error_t err = HURD_DPORT_USE (fd, __file_sync (port, 1, 0));
   if (err)
-    return __hurd_dfail (fd, err);
+    {
+      if (err == EOPNOTSUPP)
+	/* If the file descriptor does not support sync, return EINVAL
+	   as POSIX specifies.  */
+	err = EINVAL;
+      return __hurd_dfail (fd, err);
+    }
   return 0;
 }

Attachment: signature.asc
Description: This is a digitally signed message part.