On Fri, Dec 07, 2012 at 01:08:46PM +0400, Pavel Shilovsky wrote: > 2012/12/6 Pavel Shilovsky <pias...@etersoft.ru>: > > Network filesystems CIFS, SMB2.0, SMB3.0 and NFSv4 have such flags - this > > change can benefit cifs and nfs modules. While this change is ok for > > network filesystems, itsn't not targeted for local filesystems due security > > problems (e.g. when a user process can deny root to delete a file). > > > > Share flags are used by Windows applications and WINE have to deal with > > them too. While WINE can process open share flags itself on local > > filesystems, it can't do it if a file stored on a network share and is used > > by several clients. This patchset makes it possible for CIFS/SMB2.0/SMB3.0. > > > > Pavel Shilovsky (3): > > fcntl: Introduce new O_DENY* open flags for network filesystems > > CIFS: Add O_DENY* open flags support > > CIFS: Use NT_CREATE_ANDX command for forcemand mounts > > > > fs/cifs/cifsacl.c | 10 ++++---- > > fs/cifs/cifsglob.h | 11 ++++++++- > > fs/cifs/cifsproto.h | 9 ++++---- > > fs/cifs/cifssmb.c | 47 > > ++++++++++++++++++++------------------ > > fs/cifs/dir.c | 14 ++++++++---- > > fs/cifs/file.c | 18 ++++++++++----- > > fs/cifs/inode.c | 11 +++++---- > > fs/cifs/link.c | 10 ++++---- > > fs/cifs/readdir.c | 2 +- > > fs/cifs/smb1ops.c | 15 ++++++------ > > fs/cifs/smb2file.c | 10 ++++---- > > fs/cifs/smb2inode.c | 4 ++-- > > fs/cifs/smb2ops.c | 10 ++++---- > > fs/cifs/smb2pdu.c | 6 ++--- > > fs/cifs/smb2proto.h | 14 +++++++----- > > fs/fcntl.c | 5 ++-- > > include/uapi/asm-generic/fcntl.h | 11 +++++++++ > > 17 files changed, 125 insertions(+), 82 deletions(-) > > > > -- > > 1.7.10.4 > > > > First of all, sorry for being unclear at this proposal. > > > I am not from Wine team but I am working on things related to > Wine+CIFS-client+Samba. > > We (at Etersoft) need to organize the work of Wine applications > through cifs-client share mounted to Samba (or Windows server). They > are related to accounting (mostly Russian ones - e.g. > http://www.1c.ru/eng/title.htm). So, the problem is that such > applications use share flags to control the parallel access to the > same files of several clients on a remote share. Also, there can be a > situation where Windows (native) clients and Wine clients are working > together in the same time. > > That's why we need such flags in the kernel (patch #1). With these > flags Wine can pass them to every open and they will be used by CIFS > (and probably NFS) file systems to pass to the Samba server. In the > same time if the file is on local filesystem - these flags will be > simply ignored (not implemented).
NFS supports the deny-read and deny-write bits but not deny-delete. If we could do such opens in-kernel on local and clustered filesystems, that could also be useful for multi-protocol (Samba and NFS) and clustered exports. Currently knfsd tries to enforce deny bits in the nfsd code, which is a bit ugly. And knfsd currently requires write permissions for deny-read. My understanding is that Windows considers that wrong, but I'd be curious to know whether that breaks Windows applications in practice. --b. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
