linux/fs/cifs/TODO
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   1Version 1.53 May 20, 2008
   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) Support for SecurityDescriptors(Windows/CIFS ACLs) for chmod/chgrp/chown
  11so that these operations can be supported to Windows servers
  12
  13b) Mapping POSIX ACLs (and eventually NFSv4 ACLs) to CIFS
  14SecurityDescriptors
  15
  16c) Better pam/winbind integration (e.g. to handle uid mapping
  17better)
  18
  19d) Cleanup now unneeded SessSetup code in
  20fs/cifs/connect.c and add back in NTLMSSP code if any servers
  21need it
  22
  23e) fix NTLMv2 signing when two mounts with different users to same
  24server.
  25
  26f) Directory entry caching relies on a 1 second timer, rather than 
  27using FindNotify or equivalent.  - (started)
  28
  29g) quota support (needs minor kernel change since quota calls
  30to make it to network filesystems or deviceless filesystems)
  31
  32h) investigate sync behavior (including syncpage) and check  
  33for proper behavior of intr/nointr
  34
  35i) improve support for very old servers (OS/2 and Win9x for example)
  36Including support for changing the time remotely (utimes command).
  37
  38j) hook lower into the sockets api (as NFS/SunRPC does) to avoid the
  39extra copy in/out of the socket buffers in some cases.
  40
  41k) Better optimize open (and pathbased setfilesize) to reduce the
  42oplock breaks coming from windows srv.  Piggyback identical file
  43opens on top of each other by incrementing reference count rather
  44than resending (helps reduce server resource utilization and avoid
  45spurious oplock breaks).
  46
  47l) Improve performance of readpages by sending more than one read
  48at a time when 8 pages or more are requested. In conjuntion
  49add support for async_cifs_readpages.
  50
  51m) Add support for storing symlink info to Windows servers 
  52in the Extended Attribute format their SFU clients would recognize.
  53
  54n) Finish fcntl D_NOTIFY support so kde and gnome file list windows
  55will autorefresh (partially complete by Asser). Needs minor kernel
  56vfs change to support removing D_NOTIFY on a file.   
  57
  58o) Add GUI tool to configure /proc/fs/cifs settings and for display of
  59the CIFS statistics (started)
  60
  61p) implement support for security and trusted categories of xattrs
  62(requires minor protocol extension) to enable better support for SELINUX
  63
  64q) Implement O_DIRECT flag on open (already supported on mount)
  65
  66r) Create UID mapping facility so server UIDs can be mapped on a per
  67mount or a per server basis to client UIDs or nobody if no mapping
  68exists.  This is helpful when Unix extensions are negotiated to
  69allow better permission checking when UIDs differ on the server
  70and client.  Add new protocol request to the CIFS protocol 
  71standard for asking the server for the corresponding name of a
  72particular uid.
  73
  74s) Add support for CIFS Unix and also the newer POSIX extensions to the
  75server side for Samba 4.
  76
  77t) In support for OS/2 (LANMAN 1.2 and LANMAN2.1 based SMB servers) 
  78need to add ability to set time to server (utimes command)
  79
  80u) DOS attrs - returned as pseudo-xattr in Samba format (check VFAT and NTFS for this too)
  81
  82v) mount check for unmatched uids
  83
  84w) Add support for new vfs entry point for fallocate
  85
  86x) Fix Samba 3 server to handle Linux kernel aio so dbench with lots of 
  87processes can proceed better in parallel (on the server)
  88
  89y) Fix Samba 3 to handle reads/writes over 127K (and remove the cifs mount
  90restriction of wsize max being 127K) 
  91
  92KNOWN BUGS (updated April 24, 2007)
  93====================================
  94See http://bugzilla.samba.org - search on product "CifsVFS" for
  95current bug list.
  96
  971) existing symbolic links (Windows reparse points) are recognized but
  98can not be created remotely. They are implemented for Samba and those that
  99support the CIFS Unix extensions, although earlier versions of Samba
 100overly restrict the pathnames.
 1012) follow_link and readdir code does not follow dfs junctions
 102but recognizes them
 1033) create of new files to FAT partitions on Windows servers can
 104succeed but still return access denied (appears to be Windows 
 105server not cifs client problem) and has not been reproduced recently.
 106NTFS partitions do not have this problem.
 1074) Unix/POSIX capabilities are reset after reconnection, and affect
 108a few fields in the tree connection but we do do not know which
 109superblocks to apply these changes to.  We should probably walk
 110the list of superblocks to set these.  Also need to check the
 111flags on the second mount to the same share, and see if we
 112can do the same trick that NFS does to remount duplicate shares.
 113
 114Misc testing to do
 115==================
 1161) check out max path names and max path name components against various server
 117types. Try nested symlinks (8 deep). Return max path name in stat -f information
 118
 1192) Modify file portion of ltp so it can run against a mounted network
 120share and run it against cifs vfs in automated fashion.
 121
 1223) Additional performance testing and optimization using iozone and similar - 
 123there are some easy changes that can be done to parallelize sequential writes,
 124and when signing is disabled to request larger read sizes (larger than 
 125negotiated size) and send larger write sizes to modern servers.
 126
 1274) More exhaustively test against less common servers.  More testing
 128against Windows 9x, Windows ME servers.
 129
 130
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