| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1 | Version 2.11 September 13, 2017 |
| 2 | |
| 3 | A Partial List of Missing Features |
| 4 | ================================== |
| 5 | |
| 6 | Contributions are welcome. There are plenty of opportunities |
| 7 | for visible, important contributions to this module. Here |
| 8 | is a partial list of the known problems and missing features: |
| 9 | |
| 10 | a) SMB3 (and SMB3.02) missing optional features: |
| 11 | - multichannel (started), integration with RDMA |
| 12 | - directory leases (improved metadata caching), started (root dir only) |
| 13 | - T10 copy offload ie "ODX" (copy chunk, and "Duplicate Extents" ioctl |
| 14 | currently the only two server side copy mechanisms supported) |
| 15 | |
| 16 | b) improved sparse file support |
| 17 | |
| 18 | c) Directory entry caching relies on a 1 second timer, rather than |
| 19 | using Directory Leases, currently only the root file handle is cached longer |
| 20 | |
| 21 | d) quota support (needs minor kernel change since quota calls |
| 22 | to make it to network filesystems or deviceless filesystems) |
| 23 | |
| 24 | e) Compounding (in progress) to reduce number of roundtrips, and also |
| 25 | better optimize open to reduce redundant opens (using reference counts more). |
| 26 | |
| 27 | f) Finish inotify support so kde and gnome file list windows |
| 28 | will autorefresh (partially complete by Asser). Needs minor kernel |
| 29 | vfs change to support removing D_NOTIFY on a file. |
| 30 | |
| 31 | g) Add GUI tool to configure /proc/fs/cifs settings and for display of |
| 32 | the CIFS statistics (started) |
| 33 | |
| 34 | h) implement support for security and trusted categories of xattrs |
| 35 | (requires minor protocol extension) to enable better support for SELINUX |
| 36 | |
| 37 | i) Add support for tree connect contexts (see MS-SMB2) a new SMB3.1.1 protocol |
| 38 | feature (may be especially useful for virtualization). |
| 39 | |
| 40 | j) Create UID mapping facility so server UIDs can be mapped on a per |
| 41 | mount or a per server basis to client UIDs or nobody if no mapping |
| 42 | exists. Also better integration with winbind for resolving SID owners |
| 43 | |
| 44 | k) Add tools to take advantage of more smb3 specific ioctls and features |
| 45 | (passthrough ioctl/fsctl for sending various SMB3 fsctls to the server |
| 46 | is in progress) |
| 47 | |
| 48 | l) encrypted file support |
| 49 | |
| 50 | m) improved stats gathering, tools (perhaps integration with nfsometer?) |
| 51 | |
| 52 | n) allow setting more NTFS/SMB3 file attributes remotely (currently limited to compressed |
| 53 | file attribute via chflags) and improve user space tools for managing and |
| 54 | viewing them. |
| 55 | |
| 56 | o) mount helper GUI (to simplify the various configuration options on mount) |
| 57 | |
| 58 | p) Add support for witness protocol (perhaps ioctl to cifs.ko from user space |
| 59 | tool listening on witness protocol RPC) to allow for notification of share |
| 60 | move, server failover, and server adapter changes. And also improve other |
| 61 | failover scenarios, e.g. when client knows multiple DFS entries point to |
| 62 | different servers, and the server we are connected to has gone down. |
| 63 | |
| 64 | q) Allow mount.cifs to be more verbose in reporting errors with dialect |
| 65 | or unsupported feature errors. |
| 66 | |
| 67 | r) updating cifs documentation, and user guide. |
| 68 | |
| 69 | s) Addressing bugs found by running a broader set of xfstests in standard |
| 70 | file system xfstest suite. |
| 71 | |
| 72 | t) split cifs and smb3 support into separate modules so legacy (and less |
| 73 | secure) CIFS dialect can be disabled in environments that don't need it |
| 74 | and simplify the code. |
| 75 | |
| 76 | v) POSIX Extensions for SMB3.1.1 (started, create and mkdir support added |
| 77 | so far). |
| 78 | |
| 79 | KNOWN BUGS |
| 80 | ==================================== |
| 81 | See http://bugzilla.samba.org - search on product "CifsVFS" for |
| 82 | current bug list. Also check http://bugzilla.kernel.org (Product = File System, Component = CIFS) |
| 83 | |
| 84 | 1) existing symbolic links (Windows reparse points) are recognized but |
| 85 | can not be created remotely. They are implemented for Samba and those that |
| 86 | support the CIFS Unix extensions, although earlier versions of Samba |
| 87 | overly restrict the pathnames. |
| 88 | 2) follow_link and readdir code does not follow dfs junctions |
| 89 | but recognizes them |
| 90 | |
| 91 | Misc testing to do |
| 92 | ================== |
| 93 | 1) check out max path names and max path name components against various server |
| 94 | types. Try nested symlinks (8 deep). Return max path name in stat -f information |
| 95 | |
| 96 | 2) Improve xfstest's cifs/smb3 enablement and adapt xfstests where needed to test |
| 97 | cifs/smb3 better |
| 98 | |
| 99 | 3) Additional performance testing and optimization using iozone and similar - |
| 100 | there are some easy changes that can be done to parallelize sequential writes, |
| 101 | and when signing is disabled to request larger read sizes (larger than |
| 102 | negotiated size) and send larger write sizes to modern servers. |
| 103 | |
| 104 | 4) More exhaustively test against less common servers |