* autoload.cc (LoadDLLfuncNt): Re-invent.

	(NtCreateTransaction): Define.
	(NtCommitTransaction): Define.
	(NtRollbackTransaction): Define.
	(RtlGetCurrentTransaction): Define.
	(RtlSetCurrentTransaction): Define.
	* ntdll.h (TRANSACTION_ALL_ACCESS): Define.
	(NtCreateTransaction): Declare.
	(NtCommitTransaction): Declare.
	(NtRollbackTransaction): Declare.
	(RtlGetCurrentTransaction): Declare.
	(RtlSetCurrentTransaction): Declare.
	* syscalls.cc (start_transaction): New static function to start TxF
	transaction.
	(stop_transaction): New static function to end TxF transaction.
	(rename): Call start_transaction and stop_transaction where appropriate
	on systems supporting transactions.
	* wincap.h (wincaps::has_transactions): New element.
	* wincap.cc: Implement above element throughout.

6 files changed, 123 insertions, 3 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 44b94cbc1..4bc83a643 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,25 @@
+2008-05-15  Corinna Vinschen  <corinna@vinschen.de>
+
+	* autoload.cc (LoadDLLfuncNt): Re-invent.
+	(NtCreateTransaction): Define.
+	(NtCommitTransaction): Define.
+	(NtRollbackTransaction): Define.
+	(RtlGetCurrentTransaction): Define.
+	(RtlSetCurrentTransaction): Define.
+	* ntdll.h (TRANSACTION_ALL_ACCESS): Define.
+	(NtCreateTransaction): Declare.
+	(NtCommitTransaction): Declare.
+	(NtRollbackTransaction): Declare.
+	(RtlGetCurrentTransaction): Declare.
+	(RtlSetCurrentTransaction): Declare.
+	* syscalls.cc (start_transaction): New static function to start TxF
+	transaction.
+	(stop_transaction): New static function to end TxF transaction.
+	(rename): Call start_transaction and stop_transaction where appropriate
+	on systems supporting transactions.
+	* wincap.h (wincaps::has_transactions): New element.
+	* wincap.cc: Implement above element throughout.
+
 2008-05-14  Corinna Vinschen  <corinna@vinschen.de>
 
 	* fhandler_disk_file.cc (fhandler_disk_file::readdir_helper): Drop
diff --git a/winsup/cygwin/autoload.cc b/winsup/cygwin/autoload.cc
index 7f9dbe992..f9f02f289 100644
--- a/winsup/cygwin/autoload.cc
+++ b/winsup/cygwin/autoload.cc
@@ -311,6 +311,15 @@ LoadDLLfunc (NetLocalGroupGetMembers, 32, netapi32)
 LoadDLLfunc (NetUserGetGroups, 28, netapi32)
 LoadDLLfunc (NetUserGetInfo, 16, netapi32)
 
+/* 0xc000007a == STATUS_PROCEDURE_NOT_FOUND */
+#define LoadDLLfuncNt(name, n, dllname) \
+  LoadDLLfuncEx2(name, n, dllname, 1, 0xc000007a)
+LoadDLLfuncNt (NtCommitTransaction, 8, ntdll)
+LoadDLLfuncNt (NtCreateTransaction, 40, ntdll)
+LoadDLLfuncNt (NtRollbackTransaction, 8, ntdll)
+LoadDLLfuncNt (RtlGetCurrentTransaction, 0, ntdll)
+LoadDLLfuncNt (RtlSetCurrentTransaction, 4, ntdll)
+
 LoadDLLfuncEx (EnumProcessModules, 16, psapi, 1)
 LoadDLLfuncEx (GetModuleFileNameExW, 16, psapi, 1)
 LoadDLLfuncEx (GetModuleInformation, 16, psapi, 1)
diff --git a/winsup/cygwin/ntdll.h b/winsup/cygwin/ntdll.h
index bf901eaaa..cc2f95f77 100644
--- a/winsup/cygwin/ntdll.h
+++ b/winsup/cygwin/ntdll.h
@@ -77,6 +77,9 @@
 #define FILE_AUTOGENERATED_DEVICE_NAME 0x00000080
 #define FILE_DEVICE_SECURE_OPEN        0x00000100
 
+/* Transaction access rights. */
+#define TRANSACTION_ALL_ACCESS (STANDARD_RIGHTS_REQUIRED | 0x3F)
+
 typedef enum _FILE_INFORMATION_CLASS
 {
   FileDirectoryInformation = 1,
@@ -855,6 +858,7 @@ extern "C"
   NTSTATUS NTAPI NtAdjustPrivilegesToken (HANDLE, BOOLEAN, PTOKEN_PRIVILEGES,
 					  ULONG, PTOKEN_PRIVILEGES, PULONG);
   NTSTATUS NTAPI NtClose (HANDLE);
+  NTSTATUS NTAPI NtCommitTransaction (HANDLE, BOOLEAN);
   NTSTATUS NTAPI NtCreateDirectoryObject (PHANDLE, ACCESS_MASK,
 					  POBJECT_ATTRIBUTES);
   NTSTATUS NTAPI NtCreateEvent (PHANDLE, ACCESS_MASK, POBJECT_ATTRIBUTES,
@@ -876,6 +880,9 @@ extern "C"
 				PTOKEN_GROUPS, PTOKEN_PRIVILEGES, PTOKEN_OWNER,
 				PTOKEN_PRIMARY_GROUP, PTOKEN_DEFAULT_DACL,
 				PTOKEN_SOURCE);
+  NTSTATUS NTAPI NtCreateTransaction (PHANDLE, ACCESS_MASK, POBJECT_ATTRIBUTES,
+				      LPGUID, HANDLE, ULONG, ULONG, ULONG,
+				      PLARGE_INTEGER, PUNICODE_STRING);
   NTSTATUS NTAPI NtFsControlFile (HANDLE, HANDLE, PIO_APC_ROUTINE, PVOID,
 				  PIO_STATUS_BLOCK, ULONG, PVOID, ULONG,
 				  PVOID, ULONG);
@@ -929,6 +936,7 @@ extern "C"
   NTSTATUS NTAPI NtReadFile (HANDLE, HANDLE, PIO_APC_ROUTINE, PVOID,
 			     PIO_STATUS_BLOCK, PVOID, ULONG, PLARGE_INTEGER,
 			     PULONG);
+  NTSTATUS NTAPI NtRollbackTransaction (HANDLE, BOOLEAN);
   NTSTATUS NTAPI NtSetEaFile (HANDLE, PIO_STATUS_BLOCK, PVOID, ULONG);
   NTSTATUS NTAPI NtSetInformationFile (HANDLE, PIO_STATUS_BLOCK, PVOID, ULONG,
 				       FILE_INFORMATION_CLASS);
@@ -957,6 +965,7 @@ extern "C"
   VOID NTAPI RtlFreeAnsiString (PANSI_STRING);
   VOID NTAPI RtlFreeOemString (POEM_STRING);
   VOID NTAPI RtlFreeUnicodeString (PUNICODE_STRING);
+  HANDLE NTAPI RtlGetCurrentTransaction ();
   VOID NTAPI RtlInitEmptyUnicodeString (PUNICODE_STRING, PCWSTR, USHORT);
   VOID NTAPI RtlInitUnicodeString (PUNICODE_STRING, PCWSTR);
   NTSTATUS NTAPI RtlIntegerToUnicodeString (ULONG, ULONG, PUNICODE_STRING);
@@ -968,6 +977,7 @@ extern "C"
 					BOOLEAN);
   VOID NTAPI RtlReleasePebLock ();
   VOID NTAPI RtlSecondsSince1970ToTime (ULONG, PLARGE_INTEGER);
+  BOOLEAN NTAPI RtlSetCurrentTransaction (HANDLE);
   NTSTATUS NTAPI RtlUnicodeStringToAnsiString (PANSI_STRING, PUNICODE_STRING,
 					       BOOLEAN);
   NTSTATUS NTAPI RtlUnicodeStringToOemString (PANSI_STRING, PUNICODE_STRING,
diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc
index b323da203..af3d0ad17 100644
--- a/winsup/cygwin/syscalls.cc
+++ b/winsup/cygwin/syscalls.cc
@@ -1461,6 +1461,36 @@ rename_append_suffix (path_conv &pc, const char *path, size_t len,
   pc.check (buf, PC_SYM_NOFOLLOW);
 }
 
+static void
+start_transaction (HANDLE &old_trans, HANDLE &trans)
+{
+  NTSTATUS status = NtCreateTransaction (&trans,
+  				SYNCHRONIZE | TRANSACTION_ALL_ACCESS,
+				NULL, NULL, NULL, 0, 0, 0, NULL, NULL);
+  if (NT_SUCCESS (status))
+    {
+      old_trans = RtlGetCurrentTransaction ();
+      RtlSetCurrentTransaction (trans);
+    }
+  else
+    {
+      debug_printf ("NtCreateTransaction failed, %p", status);
+      old_trans = trans = NULL;
+    }
+}
+
+static NTSTATUS
+stop_transaction (NTSTATUS status, HANDLE old_trans, HANDLE trans)
+{
+  RtlSetCurrentTransaction (old_trans);
+  if (NT_SUCCESS (status))
+    status = NtCommitTransaction (trans, TRUE);
+  else
+    status = NtRollbackTransaction (trans, TRUE);
+  NtClose (trans);
+  return status;
+}
+
 extern "C" int
 rename (const char *oldpath, const char *newpath)
 {
@@ -1473,6 +1503,7 @@ rename (const char *oldpath, const char *newpath)
   bool equal_path;
   NTSTATUS status;
   HANDLE fh = NULL, nfh;
+  HANDLE old_trans = NULL, trans = NULL;
   OBJECT_ATTRIBUTES attr;
   IO_STATUS_BLOCK io;
   ULONG size;
@@ -1681,6 +1712,13 @@ rename (const char *oldpath, const char *newpath)
     }
   dstpc = (removepc == &newpc) ? &new2pc : &newpc;
 
+  /* Opening the file must be part of the transaction.  It's not sufficient
+     to call only NtSetInformationFile under the transaction.  Therefore we
+     have to start the transaction here, if necessary. */
+  if (wincap.has_transactions ()
+      && (dstpc->isdir () || dstpc->has_attribute (FILE_ATTRIBUTE_READONLY)))
+    start_transaction (old_trans, trans);
+
   /* DELETE is required to rename a file. */
   status = NtOpenFile (&fh, DELETE, oldpc.get_object_attr (attr, sec_none_nih),
 		     &io, FILE_SHARE_VALID_FLAGS,
@@ -1789,9 +1827,36 @@ rename (const char *oldpath, const char *newpath)
      existing file, if the permissions of the existing file aren't right.
      Like directories, we have to handle this separately by removing the
      destination before renaming. */
-  if (status == STATUS_ACCESS_DENIED && dstpc->exists () && !dstpc->isdir ()
-      && NT_SUCCESS (status = unlink_nt (*dstpc)))
-    status = NtSetInformationFile (fh, &io, pfri, size, FileRenameInformation);
+  if (status == STATUS_ACCESS_DENIED && dstpc->exists () && !dstpc->isdir ())
+    {
+      if (wincap.has_transactions () && !trans)
+	{
+	  start_transaction (old_trans, trans);
+	  /* As mentioned earlier, opening the file must be part of the
+	     transaction.  Therefore we have to reopen the file here if the
+	     transaction hasn't been started already.  Unfortunately we can't
+	     use the NT "reopen file from existing handle" feature.  In that
+	     case NtOpenFile returns STATUS_TRANSACTIONAL_CONFLICT.  We *have*
+	     to close the handle to the file first, *then* we can re-open it.
+	     Fortunately nothing has happened yet, so the atomicity of the
+	     rename functionality is not spoiled. */
+	  NtClose (fh);
+	  status = NtOpenFile (&fh, DELETE,
+			       oldpc.get_object_attr (attr, sec_none_nih),
+			       &io, FILE_SHARE_VALID_FLAGS,
+			       FILE_OPEN_FOR_BACKUP_INTENT
+			       | (oldpc.is_rep_symlink ()
+				  ? FILE_OPEN_REPARSE_POINT : 0));
+	  if (!NT_SUCCESS (status))
+	    {
+	      __seterrno_from_nt_status (status);
+	      goto out;
+	    }
+	}
+      if (NT_SUCCESS (status = unlink_nt (*dstpc)))
+	status = NtSetInformationFile (fh, &io, pfri, size,
+				       FileRenameInformation);
+    }
   if (NT_SUCCESS (status))
     {
       if (removepc)
@@ -1804,6 +1869,8 @@ rename (const char *oldpath, const char *newpath)
 out:
   if (fh)
     NtClose (fh);
+  if (wincap.has_transactions () && trans)
+    stop_transaction (status, old_trans, trans);
   syscall_printf ("%d = rename (%s, %s)", res, oldpath, newpath);
   return res;
 }
diff --git a/winsup/cygwin/wincap.cc b/winsup/cygwin/wincap.cc
index 4ce3ca1ce..cf44dcc79 100644
--- a/winsup/cygwin/wincap.cc
+++ b/winsup/cygwin/wincap.cc
@@ -42,6 +42,7 @@ static NO_COPY wincaps wincap_unknown = {
   has_gaa_on_link_prefix:false,
   supports_all_posix_ai_flags:false,
   has_restricted_stack_args:false,
+  has_transactions:false,
 };
 
 static NO_COPY wincaps wincap_nt4 = {
@@ -72,6 +73,7 @@ static NO_COPY wincaps wincap_nt4 = {
   has_gaa_on_link_prefix:false,
   supports_all_posix_ai_flags:false,
   has_restricted_stack_args:false,
+  has_transactions:false,
 };
 
 static NO_COPY wincaps wincap_nt4sp4 = {
@@ -102,6 +104,7 @@ static NO_COPY wincaps wincap_nt4sp4 = {
   has_gaa_on_link_prefix:false,
   supports_all_posix_ai_flags:false,
   has_restricted_stack_args:false,
+  has_transactions:false,
 };
 
 static NO_COPY wincaps wincap_2000 = {
@@ -132,6 +135,7 @@ static NO_COPY wincaps wincap_2000 = {
   has_gaa_on_link_prefix:false,
   supports_all_posix_ai_flags:false,
   has_restricted_stack_args:false,
+  has_transactions:false,
 };
 
 static NO_COPY wincaps wincap_2000sp4 = {
@@ -162,6 +166,7 @@ static NO_COPY wincaps wincap_2000sp4 = {
   has_gaa_on_link_prefix:false,
   supports_all_posix_ai_flags:false,
   has_restricted_stack_args:false,
+  has_transactions:false,
 };
 
 static NO_COPY wincaps wincap_xp = {
@@ -192,6 +197,7 @@ static NO_COPY wincaps wincap_xp = {
   has_gaa_on_link_prefix:false,
   supports_all_posix_ai_flags:false,
   has_restricted_stack_args:false,
+  has_transactions:false,
 };
 
 static NO_COPY wincaps wincap_xpsp1 = {
@@ -222,6 +228,7 @@ static NO_COPY wincaps wincap_xpsp1 = {
   has_gaa_on_link_prefix:false,
   supports_all_posix_ai_flags:false,
   has_restricted_stack_args:false,
+  has_transactions:false,
 };
 
 static NO_COPY wincaps wincap_xpsp2 = {
@@ -252,6 +259,7 @@ static NO_COPY wincaps wincap_xpsp2 = {
   has_gaa_on_link_prefix:false,
   supports_all_posix_ai_flags:false,
   has_restricted_stack_args:false,
+  has_transactions:false,
 };
 
 static NO_COPY wincaps wincap_2003 = {
@@ -282,6 +290,7 @@ static NO_COPY wincaps wincap_2003 = {
   has_gaa_on_link_prefix:false,
   supports_all_posix_ai_flags:false,
   has_restricted_stack_args:true,
+  has_transactions:false,
 };
 
 static NO_COPY wincaps wincap_vista = {
@@ -312,6 +321,7 @@ static NO_COPY wincaps wincap_vista = {
   has_gaa_on_link_prefix:true,
   supports_all_posix_ai_flags:true,
   has_restricted_stack_args:false,
+  has_transactions:true,
 };
 
 wincapc wincap __attribute__((section (".cygwin_dll_common"), shared));
diff --git a/winsup/cygwin/wincap.h b/winsup/cygwin/wincap.h
index b1b8a3c72..2035ecc5a 100644
--- a/winsup/cygwin/wincap.h
+++ b/winsup/cygwin/wincap.h
@@ -40,6 +40,7 @@ struct wincaps
   unsigned has_gaa_on_link_prefix			: 1;
   unsigned supports_all_posix_ai_flags			: 1;
   unsigned has_restricted_stack_args			: 1;
+  unsigned has_transactions				: 1;
 };
 
 class wincapc
@@ -86,6 +87,7 @@ public:
   bool	IMPLEMENT (has_gaa_on_link_prefix)
   bool	IMPLEMENT (supports_all_posix_ai_flags)
   bool	IMPLEMENT (has_restricted_stack_args)
+  bool	IMPLEMENT (has_transactions)
 
 #undef IMPLEMENT
 };