diff options
| -rw-r--r-- | winsup/cygwin/ChangeLog | 7 | ||||
| -rw-r--r-- | winsup/cygwin/path.h | 1 | ||||
| -rw-r--r-- | winsup/cygwin/syscalls.cc | 74 |
3 files changed, 74 insertions, 8 deletions
diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog index 44d6b8e50..863fb560f 100644 --- a/winsup/cygwin/ChangeLog +++ b/winsup/cygwin/ChangeLog @@ -1,3 +1,10 @@ +2013-01-10 Corinna Vinschen <corinna@vinschen.de> + + * path.h (path_conv::fs_type): New method. + * syscalls.cc (rename): Check for cross-device situation before + touching anything. Explain why. Workaround NFS bug in call to + NtSetInformationFile(FileRenameInformation). + 2013-01-09 Corinna Vinschen <corinna@vinschen.de> * cygerrno.h: Fix copyright. diff --git a/winsup/cygwin/path.h b/winsup/cygwin/path.h index 4535c7e49..139cd86ee 100644 --- a/winsup/cygwin/path.h +++ b/winsup/cygwin/path.h @@ -362,6 +362,7 @@ class path_conv bool fs_is_cifs () const {return fs.is_cifs ();} bool fs_is_nwfs () const {return fs.is_nwfs ();} bool fs_is_ncfsd () const {return fs.is_ncfsd ();} + fs_info_type fs_type () const {return fs.what_fs ();} ULONG fs_serial_number () const {return fs.serial_number ();} inline const char *set_path (const char *p) { diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc index fe89f8493..1aedc1f61 100644 --- a/winsup/cygwin/syscalls.cc +++ b/winsup/cygwin/syscalls.cc @@ -2297,6 +2297,15 @@ rename (const char *oldpath, const char *newpath) } dstpc = (removepc == &newpc) ? &new2pc : &newpc; + /* Check cross-device before touching anything. Otherwise we might end + up with an unlinked target dir even if the actual rename didn't work. */ + if (oldpc.fs_type () != dstpc->fs_type () + || oldpc.fs_serial_number () != dstpc->fs_serial_number ()) + { + set_errno (EXDEV); + goto out; + } + /* 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. */ @@ -2431,17 +2440,66 @@ retry: } NtClose (nfh); } - size = sizeof (FILE_RENAME_INFORMATION) - + dstpc->get_nt_native_path ()->Length; - if (size > NT_MAX_PATH * sizeof (WCHAR)) /* Hopefully very seldom. */ - pfri = (PFILE_RENAME_INFORMATION) alloca (size); + if (oldpc.fs_is_nfs ()) + { + /* Workaround depressing NFS bug. FILE_RENAME_INFORMATION.FileName + *must* be relative to the parent directory of the original file, + otherwise NtSetInformationFile returns with STATUS_NOT_SAME_DEVICE. + Neither absolute paths, nor directory handle relative paths work + as expected! */ + PWCHAR oldp, dstp; + + /* Skip equivalent path prefix. We already know that both paths are + on the same drive anyway. */ + for (oldp = oldpc.get_nt_native_path ()->Buffer, + dstp = dstpc->get_nt_native_path ()->Buffer; + *oldp == *dstp; ++oldp, ++dstp) + ; + while (oldp[-1] != L'\\') + --oldp, --dstp; + /* Now oldp points to the first path component in oldpc different from + dstpc, vice versa for dstp and oldpc. To create a dstpc path relative + to oldpc, we now have to prepend as many ".." components to dstp, as + are still available in oldp. Example: + + oldpc = \??\UNC\server\a\b\c\d\e + dstpc = \??\UNC\server\a\b\f\g + + prefix: \??\UNC\server\a\b\ + oldp: c\d\e + dstp: f\g + dstp expressed relative to e's parent dir: ..\..\f\g + + So what we do here is to count the number of backslashes in oldp and + prepend one "..\" to dstp for each of them. */ + PWCHAR newdst = tp.w_get (); + PWCHAR newp = newdst; + while ((oldp = wcschr (++oldp, L'\\')) != NULL) + newp = wcpcpy (newp, L"..\\"); + newp = wcpcpy (newp, dstp); + size = sizeof (FILE_RENAME_INFORMATION) + + (newp - newdst) * sizeof (WCHAR); + if (size > NT_MAX_PATH * sizeof (WCHAR)) /* Hopefully very seldom. */ + pfri = (PFILE_RENAME_INFORMATION) alloca (size); + else + pfri = (PFILE_RENAME_INFORMATION) tp.w_get (); + pfri->FileNameLength = (newp - newdst) * sizeof (WCHAR); + memcpy (&pfri->FileName, newdst, pfri->FileNameLength); + } else - pfri = (PFILE_RENAME_INFORMATION) tp.w_get (); + { + size = sizeof (FILE_RENAME_INFORMATION) + + dstpc->get_nt_native_path ()->Length; + if (size > NT_MAX_PATH * sizeof (WCHAR)) /* Hopefully very seldom. */ + pfri = (PFILE_RENAME_INFORMATION) alloca (size); + else + pfri = (PFILE_RENAME_INFORMATION) tp.w_get (); + pfri->FileNameLength = dstpc->get_nt_native_path ()->Length; + memcpy (&pfri->FileName, dstpc->get_nt_native_path ()->Buffer, + pfri->FileNameLength); + } pfri->ReplaceIfExists = TRUE; pfri->RootDirectory = NULL; - pfri->FileNameLength = dstpc->get_nt_native_path ()->Length; - memcpy (&pfri->FileName, dstpc->get_nt_native_path ()->Buffer, - pfri->FileNameLength); status = NtSetInformationFile (fh, &io, pfri, size, FileRenameInformation); /* This happens if the access rights don't allow deleting the destination. Even if the handle to the original file is opened with BACKUP |