1Version 2.03 August 1, 2014
  2
  3A Partial List of Missing Features
  4==================================
  5
  6Contributions are welcome.  There are plenty of opportunities
  7for visible, important contributions to this module.  Here
  8is a partial list of the known problems and missing features:
  9
 10a) SMB3 (and SMB3.02) missing optional features:
 11   - RDMA
 12   - multichannel (started)
 13   - directory leases (improved metadata caching)
 14   - T10 copy offload (copy chunk is only mechanism supported)
 15   - encrypted shares
 16
 17b) improved sparse file support
 18
 19c) Directory entry caching relies on a 1 second timer, rather than
 20using FindNotify or equivalent.  - (started)
 21
 22d) quota support (needs minor kernel change since quota calls
 23to make it to network filesystems or deviceless filesystems)
 24
 25e) improve support for very old servers (OS/2 and Win9x for example)
 26Including support for changing the time remotely (utimes command).
 27
 28f) hook lower into the sockets api (as NFS/SunRPC does) to avoid the
 29extra copy in/out of the socket buffers in some cases.
 30
 31g) Better optimize open (and pathbased setfilesize) to reduce the
 32oplock breaks coming from windows srv.  Piggyback identical file
 33opens on top of each other by incrementing reference count rather
 34than resending (helps reduce server resource utilization and avoid
 35spurious oplock breaks).
 36
 37h) Add support for storing symlink info to Windows servers
 38in the Extended Attribute format their SFU clients would recognize.
 39
 40i) Finish inotify support so kde and gnome file list windows
 41will autorefresh (partially complete by Asser). Needs minor kernel
 42vfs change to support removing D_NOTIFY on a file.   
 43
 44j) Add GUI tool to configure /proc/fs/cifs settings and for display of
 45the CIFS statistics (started)
 46
 47k) implement support for security and trusted categories of xattrs
 48(requires minor protocol extension) to enable better support for SELINUX
 49
 50l) Implement O_DIRECT flag on open (already supported on mount)
 51
 52m) Create UID mapping facility so server UIDs can be mapped on a per
 53mount or a per server basis to client UIDs or nobody if no mapping
 54exists.  This is helpful when Unix extensions are negotiated to
 55allow better permission checking when UIDs differ on the server
 56and client.  Add new protocol request to the CIFS protocol 
 57standard for asking the server for the corresponding name of a
 58particular uid.
 59
 60n) DOS attrs - returned as pseudo-xattr in Samba format (check VFAT and NTFS for this too)
 61
 62o) mount check for unmatched uids
 63
 64p) Add support for new vfs entry point for fallocate
 65
 66q) Add tools to take advantage of cifs/smb3 specific ioctls and features
 67such as "CopyChunk" (fast server side file copy)
 68
 69r) encrypted file support
 70
 71s) improved stats gathering, tools (perhaps integration with nfsometer?)
 72
 73t) allow setting more NTFS/SMB3 file attributes remotely (currently limited to compressed
 74file attribute via chflags)
 75
 76u) mount helper GUI (to simplify the various configuration options on mount)
 77
 78
 79KNOWN BUGS
 80====================================
 81See http://bugzilla.samba.org - search on product "CifsVFS" for
 82current bug list.  Also check http://bugzilla.kernel.org (Product = File System, Component = CIFS)
 83
 841) existing symbolic links (Windows reparse points) are recognized but
 85can not be created remotely. They are implemented for Samba and those that
 86support the CIFS Unix extensions, although earlier versions of Samba
 87overly restrict the pathnames.
 882) follow_link and readdir code does not follow dfs junctions
 89but recognizes them
 90
 91Misc testing to do
 92==================
 931) check out max path names and max path name components against various server
 94types. Try nested symlinks (8 deep). Return max path name in stat -f information
 95
 962) Improve xfstest's cifs enablement and adapt xfstests where needed to test
 97cifs better
 98
 993) Additional performance testing and optimization using iozone and similar - 
100there are some easy changes that can be done to parallelize sequential writes,
101and when signing is disabled to request larger read sizes (larger than 
102negotiated size) and send larger write sizes to modern servers.
103
1044) More exhaustively test against less common servers