libs/newlib-cygwin
libs
/
newlib-cygwin
mirror of git://sourceware.org/git/newlib-cygwin.git
4
0
Fork 0
Code Issues Projects Releases Wiki Activity

* syscalls.cc (start_transaction): Make inline function. Move up to be 

more generally available.
	(stop_transaction): Ditto.
	(unlink_nt): Potentially start transaction when trying to delete file
	with DOS R/O attribute set.  If file is .lnk symlink, check for number
	of hardlinks.  Add "out" label and only return via "out".  Rearrange
	reversion of DOS R/O attribute and, on success, only revert R/O
	attribute if file is .lnk symlink with more than one hardlink.  Add
	length comment to explain why.
This commit is contained in:
Corinna Vinschen 2010-09-12 11:41:56 +00:00
parent 2981e56e29
commit 18df393573
2 changed files with 97 additions and 42 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
winsup/cygwin/ChangeLog
View File

@ -1,3 +1,15 @@
2010-09-12 Corinna Vinschen <corinna@vinschen.de>
* syscalls.cc (start_transaction): Make inline function. Move up to be
more generally available.
(stop_transaction): Ditto.
(unlink_nt): Potentially start transaction when trying to delete file
with DOS R/O attribute set. If file is .lnk symlink, check for number
of hardlinks. Add "out" label and only return via "out". Rearrange
reversion of DOS R/O attribute and, on success, only revert R/O
attribute if file is .lnk symlink with more than one hardlink. Add
length comment to explain why.
2010-09-11 Corinna Vinschen <corinna@vinschen.de>
* fhandler_disk_file.cc (fhandler_disk_file::rmdir): More thoroughly

127
winsup/cygwin/syscalls.cc
View File

@ -164,6 +164,36 @@ dup3 (int oldfd, int newfd, int flags)
return cygheap->fdtab.dup3 (oldfd, newfd, flags);
}
static inline 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 inline 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;
}
static char desktop_ini[] =
"[.ShellClassInfo]\r\nCLSID={645FF040-5081-101B-9F08-00AA002F954E}\r\n";
static BYTE info2[] =
@ -503,6 +533,9 @@ unlink_nt (path_conv &pc)
HANDLE fh, fh_ro = NULL;
OBJECT_ATTRIBUTES attr;
IO_STATUS_BLOCK io;
HANDLE old_trans = NULL, trans = NULL;
ULONG num_links = 1;
FILE_DISPOSITION_INFORMATION disp = { TRUE };
bin_status bin_stat = dont_move;
@ -522,7 +555,14 @@ unlink_nt (path_conv &pc)
attribute, just re-open the file for DELETE and go ahead. */
if (pc.file_attributes () & FILE_ATTRIBUTE_READONLY)
{
access |= FILE_WRITE_ATTRIBUTES;
FILE_STANDARD_INFORMATION fsi;
/* If possible, hide the non-atomicity of the "remove R/O flag, remove
link to file" operation behind a transaction. */
if (wincap.has_transactions ()
&& (pc.fs_flags () & FILE_SUPPORTS_TRANSACTIONS))
start_transaction (old_trans, trans);
status = NtOpenFile (&fh_ro, FILE_WRITE_ATTRIBUTES, &attr, &io,
FILE_SHARE_VALID_FLAGS, flags);
if (NT_SUCCESS (status))
@ -532,6 +572,14 @@ unlink_nt (path_conv &pc)
InitializeObjectAttributes (&attr, &ro_u_empty,
pc.objcaseinsensitive (), fh_ro, NULL);
}
if (pc.is_lnk_symlink ())
{
status = NtQueryInformationFile (fh_ro, &io, &fsi, sizeof fsi,
FileStandardInformation);
if (NT_SUCCESS (status))
num_links = fsi.NumberOfLinks;
}
access |= FILE_WRITE_ATTRIBUTES;
}
/* First try to open the file with only allowing sharing for delete. If
the file has an open handle on it, other than just for deletion, this
@ -589,7 +637,7 @@ unlink_nt (path_conv &pc)
NtClose (fh);
if (fh_ro)
NtClose (fh_ro);
return status;
goto out;
}
}
}
@ -601,18 +649,21 @@ unlink_nt (path_conv &pc)
if (status == STATUS_DELETE_PENDING)
{
syscall_printf ("Delete already pending");
return 0;
status = 0;
goto out;
}
syscall_printf ("Opening file for delete failed, status = %p", status);
return status;
goto out;
}
/* Try to move to bin if a sharing violation occured. If that worked,
we're done. */
if (bin_stat == move_to_bin
&& (bin_stat = try_to_bin (pc, fh, access)) == has_been_moved)
return 0;
{
status = 0;
goto out;
}
/* Try to set delete disposition. */
FILE_DISPOSITION_INFORMATION disp = { TRUE };
status = NtSetInformationFile (fh, &io, &disp, sizeof disp,
FileDispositionInformation);
if (!NT_SUCCESS (status))
@ -661,14 +712,36 @@ unlink_nt (path_conv &pc)
}
if (fh)
{
/* Restore R/O attribute to accommodate hardlinks. Don't try this
with directories! For some reason the below NtSetInformationFile
changes the delete disposition back to FALSE, at least on XP. */
if ((access & FILE_WRITE_ATTRIBUTES)
&& (!NT_SUCCESS (status) || !pc.isdir ()))
NtSetAttributesFile (fh, pc.file_attributes ());
if (access & FILE_WRITE_ATTRIBUTES)
{
/* Restore R/O attribute if setting the delete dispostion failed. */
if (!NT_SUCCESS (status))
NtSetAttributesFile (fh, pc.file_attributes ());
/* If we succeeded, restore R/O attribute to accommodate hardlinks.
Only ever try to do this for our own winsymlinks, because there's
a problem with setting the delete disposition:
http://msdn.microsoft.com/en-us/library/ff545765%28VS.85%29.aspx
"Subsequently, the only legal operation by such a caller is
to close the open file handle."
FIXME? On Vista and later, we could use FILE_HARD_LINK_INFORMATION
to find all hardlinks and use one of them to restore the R/O bit,
after the NtClose, but before we stop the transaction. This
avoids the aforementioned problem entirely . */
else if (pc.is_lnk_symlink () && num_links > 1)
NtSetAttributesFile (fh, pc.file_attributes ());
}
NtClose (fh);
}
out:
/* Stop transaction if we started one. */
if ((access & FILE_WRITE_ATTRIBUTES)
&& wincap.has_transactions ()
&& (pc.fs_flags () & FILE_SUPPORTS_TRANSACTIONS))
stop_transaction (status, old_trans, trans);
return status;
}
@ -1658,36 +1731,6 @@ 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;
}
/* This function tests if a filename has one of the "approved" executable
suffix. This list is probably not complete... */
static inline bool