cifs: Fix and improve cifs_query_path_info() and cifs_query_file_info()

When CAP_NT_SMBS was not negotiated then do not issue CIFSSMBQPathInfo()
and CIFSSMBQFileInfo() commands. CIFSSMBQPathInfo() is not supported by
non-NT Win9x SMB server and CIFSSMBQFileInfo() returns from Win9x SMB
server bogus data in Attributes field (for example lot of files are marked
as reparse points, even Win9x does not support them and read-only bit is
not marked for read-only files). Correct information is returned by
CIFSFindFirst() or SMBQueryInformation() command.

So as a fallback in cifs_query_path_info() function use CIFSFindFirst()
with SMB_FIND_FILE_FULL_DIRECTORY_INFO level which is supported by both NT
and non-NT servers and as a last option use SMBQueryInformation() as it was
before.

And in function cifs_query_file_info() immediately returns -EOPNOTSUPP when
not communicating with NT server. Client then revalidate inode entry by the
cifs_query_path_info() call, which is working fine. So fstat() syscall on
already opened file will receive correct information.

Note that both fallback functions in non-UNICODE mode expands wildcards.
Therefore those fallback functions cannot be used on paths which contain
SMB wildcard characters (* ? " > <).

CIFSFindFirst() returns all 4 time attributes as opposite of
SMBQueryInformation() which returns only one.

With this change it is possible to query all 4 times attributes from Win9x
server and at the same time, client minimize sending of unsupported
commands to server.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

0 files changed, 0 insertions, 0 deletions