* fhandler.cc (fhandler_base::open): Always open NFS files with

	FILE_READ_EA, even when opening with O_WRONLY to allow fstat.
	* fhandler_disk_file.cc (fhandler_base::fstat_by_nfs_ea): Call
	FlushFileBuffers if file has been opened for writing.  Explain why.
	(fhandler_base::fstat_by_handle): Renew content of pc.fnoi if called
	via fstat.  Explain why.  Fix formatting.
	* path.cc (symlink_info::check): Try to open file the second time with
	FILE_READ_EA permissions since it's needed in later calls to
	fhandler_base::fstat_by_nfs_ea.

4 files changed, 52 insertions, 11 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index b854c378b..9788adef9 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,15 @@
+2010-09-21  Corinna Vinschen  <corinna@vinschen.de>
+
+	* fhandler.cc (fhandler_base::open): Always open NFS files with
+	FILE_READ_EA, even when opening with O_WRONLY to allow fstat.
+	* fhandler_disk_file.cc (fhandler_base::fstat_by_nfs_ea): Call
+	FlushFileBuffers if file has been opened for writing.  Explain why.
+	(fhandler_base::fstat_by_handle): Renew content of pc.fnoi if called
+	via fstat.  Explain why.  Fix formatting.
+	* path.cc (symlink_info::check): Try to open file the second time with
+	FILE_READ_EA permissions since it's needed in later calls to
+	fhandler_base::fstat_by_nfs_ea.
+
 2010-09-20  Christopher Faylor  <me+cygwin@cgf.cx>
 
 	* include/sys/cygwin.h (PID_NOTCYGWIN): New enum.
diff --git a/winsup/cygwin/fhandler.cc b/winsup/cygwin/fhandler.cc
index 1998979f7..64451f672 100644
--- a/winsup/cygwin/fhandler.cc
+++ b/winsup/cygwin/fhandler.cc
@@ -501,16 +501,19 @@ fhandler_base::open (int flags, mode_t mode)
 	break;
     }
 
-  if (query_open () && pc.fs_is_nfs ())
+  if (pc.fs_is_nfs ())
     {
       /* Make sure we can read EAs of files on an NFS share.  Also make
-	 sure that we're going to act on the file itself, even if it'a
+	 sure that we're going to act on the file itself, even if it's a
 	 a symlink. */
       access |= FILE_READ_EA;
-      if (query_open () >= query_write_control)
-	access |=  FILE_WRITE_EA;
-      plen = sizeof nfs_aol_ffei;
-      p = (PFILE_FULL_EA_INFORMATION) &nfs_aol_ffei;
+      if (query_open ())
+	{
+	  if (query_open () >= query_write_control)
+	    access |=  FILE_WRITE_EA;
+	  plen = sizeof nfs_aol_ffei;
+	  p = (PFILE_FULL_EA_INFORMATION) &nfs_aol_ffei;
+	}
     }
 
   if ((flags & O_TRUNC) && ((flags & O_ACCMODE) != O_RDONLY))
diff --git a/winsup/cygwin/fhandler_disk_file.cc b/winsup/cygwin/fhandler_disk_file.cc
index 02376f6a5..cff345d31 100644
--- a/winsup/cygwin/fhandler_disk_file.cc
+++ b/winsup/cygwin/fhandler_disk_file.cc
@@ -305,6 +305,14 @@ fhandler_base::fstat_by_nfs_ea (struct __stat64 *buf)
      char buf[sizeof (NFS_V3_ATTR)];
    } fgei_buf;
 
+  /* NFS stumbles over its own caching.  If you write to the file,
+     a subsequent fstat does not return the actual size of the file,
+     but the size at the time the handle has been opened.  Unless
+     access through another handle invalidates the caching within the
+     NFS client. */
+  if (get_io_handle () && (get_access () & GENERIC_WRITE))
+    FlushFileBuffers (get_io_handle ());
+
   fgei_buf.fgei.NextEntryOffset = 0;
   fgei_buf.fgei.EaNameLength = sizeof (NFS_V3_ATTR) - 1;
   stpcpy (fgei_buf.fgei.EaName, NFS_V3_ATTR);
@@ -356,6 +364,21 @@ fhandler_base::fstat_by_handle (struct __stat64 *buf)
   NTSTATUS status = 0;
   IO_STATUS_BLOCK io;
 
+  /* If the file has been opened for other purposes than stat, we can't rely
+     on the information stored in pc.fnoi.  So we overwrite them here. */
+  if (get_io_handle ())
+    {
+      PFILE_NETWORK_OPEN_INFORMATION pfnoi = pc.fnoi ();
+      status = NtQueryInformationFile (h, &io, pfnoi, sizeof *pfnoi,
+                                      FileNetworkOpenInformation);
+      if (!NT_SUCCESS (status))
+       {
+	 debug_printf ("%p = NtQueryInformationFile(%S, "
+		       "FileNetworkOpenInformation)",
+		       status, pc.get_nt_native_path ());
+	 return -1;
+       }
+    }
   if (!pc.hasgood_inode ())
     fsi.NumberOfLinks = 1;
   else
@@ -364,7 +387,8 @@ fhandler_base::fstat_by_handle (struct __stat64 *buf)
 				       FileStandardInformation);
       if (!NT_SUCCESS (status))
 	{
-	  debug_printf ("%p = NtQueryInformationFile(%S, FileStandardInformation)",
+	  debug_printf ("%p = NtQueryInformationFile(%S, "
+			"FileStandardInformation)",
 			status, pc.get_nt_native_path ());
 	  return -1;
 	}
@@ -374,7 +398,8 @@ fhandler_base::fstat_by_handle (struct __stat64 *buf)
 					   FileInternalInformation);
 	  if (!NT_SUCCESS (status))
 	    {
-	      debug_printf ("%p = NtQueryInformationFile(%S, FileInternalInformation)",
+	      debug_printf ("%p = NtQueryInformationFile(%S, "
+			    "FileInternalInformation)",
 			    status, pc.get_nt_native_path ());
 	      return -1;
 	    }
diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
index d29aff028..32bb4c0a9 100644
--- a/winsup/cygwin/path.cc
+++ b/winsup/cygwin/path.cc
@@ -2296,10 +2296,11 @@ restart:
 			     FILE_OPEN_REPARSE_POINT
 			     | FILE_OPEN_FOR_BACKUP_INTENT,
 			     eabuf, easize);
-      if (status == STATUS_ACCESS_DENIED)
+      if (status == STATUS_ACCESS_DENIED && eabuf)
 	{
-	  status = NtCreateFile (&h, access = MIN_STAT_ACCESS, &attr, &io,
-				 NULL, 0, FILE_SHARE_VALID_FLAGS, FILE_OPEN,
+	  status = NtCreateFile (&h, access = MIN_STAT_ACCESS | FILE_READ_EA,
+				 &attr, &io, NULL, 0, FILE_SHARE_VALID_FLAGS,
+				 FILE_OPEN,
 				 FILE_OPEN_REPARSE_POINT
 				 | FILE_OPEN_FOR_BACKUP_INTENT,
 				 eabuf, easize);