1Version 2.11 September 13, 2017
  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   - multichannel (started), integration with RDMA
 
 12   - directory leases (improved metadata caching)
 13   - T10 copy offload (copy chunk, and "Duplicate Extents" ioctl
 14     currently the only two server side copy mechanisms supported)
 15
 16b) improved sparse file support
 17
 18c) Directory entry caching relies on a 1 second timer, rather than
 19using Directory Leases
 20
 21d) quota support (needs minor kernel change since quota calls
 22to make it to network filesystems or deviceless filesystems)
 23
 24e) Compounding (in progress) to reduce number of roundtrips, and also
 25better optimize open to reduce redundant opens (using reference counts more).
 26
 27f) Finish inotify support so kde and gnome file list windows
 
 
 
 
 
 
 
 
 
 
 
 
 28will autorefresh (partially complete by Asser). Needs minor kernel
 29vfs change to support removing D_NOTIFY on a file.   
 30
 31g) Add GUI tool to configure /proc/fs/cifs settings and for display of
 32the CIFS statistics (started)
 33
 34h) implement support for security and trusted categories of xattrs
 35(requires minor protocol extension) to enable better support for SELINUX
 36
 37i) Add support for tree connect contexts (see MS-SMB2) a new SMB3.1.1 protocol
 38   feature (may be especially useful for virtualization).
 39
 40j) Create UID mapping facility so server UIDs can be mapped on a per
 41mount or a per server basis to client UIDs or nobody if no mapping
 42exists. Also better integration with winbind for resolving SID owners
 43
 44k) Add tools to take advantage of more smb3 specific ioctls and features
 45
 46l) encrypted file support
 47
 48m) improved stats gathering, tools (perhaps integration with nfsometer?)
 49
 50n) allow setting more NTFS/SMB3 file attributes remotely (currently limited to compressed
 51file attribute via chflags) and improve user space tools for managing and
 52viewing them.
 53
 54o) mount helper GUI (to simplify the various configuration options on mount)
 55
 56p) Add support for witness protocol (perhaps ioctl to cifs.ko from user space
 57   tool listening on witness protocol RPC) to allow for notification of share
 58   move, server failover, and server adapter changes.  And also improve other
 59   failover scenarios, e.g. when client knows multiple DFS entries point to
 60   different servers, and the server we are connected to has gone down.
 61
 62q) Allow mount.cifs to be more verbose in reporting errors with dialect
 63or unsupported feature errors.
 64
 65r) updating cifs documentation, and user guide.
 66
 67s) Addressing bugs found by running a broader set of xfstests in standard
 68file system xfstest suite.
 69
 70t) split cifs and smb3 support into separate modules so legacy (and less
 71secure) CIFS dialect can be disabled in environments that don't need it
 72and simplify the code.
 73
 74u) Finish up SMB3.1.1 dialect support
 75
 76v) POSIX Extensions for SMB3.1.1
 77
 78KNOWN BUGS
 79====================================
 80See http://bugzilla.samba.org - search on product "CifsVFS" for
 81current bug list.  Also check http://bugzilla.kernel.org (Product = File System, Component = CIFS)
 82
 831) existing symbolic links (Windows reparse points) are recognized but
 84can not be created remotely. They are implemented for Samba and those that
 85support the CIFS Unix extensions, although earlier versions of Samba
 86overly restrict the pathnames.
 872) follow_link and readdir code does not follow dfs junctions
 88but recognizes them
 89
 90Misc testing to do
 91==================
 921) check out max path names and max path name components against various server
 93types. Try nested symlinks (8 deep). Return max path name in stat -f information
 94
 952) Improve xfstest's cifs enablement and adapt xfstests where needed to test
 96cifs better
 97
 983) Additional performance testing and optimization using iozone and similar - 
 99there are some easy changes that can be done to parallelize sequential writes,
100and when signing is disabled to request larger read sizes (larger than 
101negotiated size) and send larger write sizes to modern servers.
102
1034) More exhaustively test against less common servers

  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