Based on kernel version 4.16.1. Page generated on 2018-04-09 11:53 EST.
1 Version 2.04 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 - RDMA (started) 12 - multichannel (started) 13 - directory leases (improved metadata caching) 14 - T10 copy offload (copy chunk is only mechanism 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 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) Better optimize open to reduce redundant opens (using reference 25 counts more) and to improve use of compounding in SMB3 to reduce 26 number of roundtrips. 27 28 f) Finish inotify support so kde and gnome file list windows 29 will autorefresh (partially complete by Asser). Needs minor kernel 30 vfs change to support removing D_NOTIFY on a file. 31 32 g) Add GUI tool to configure /proc/fs/cifs settings and for display of 33 the CIFS statistics (started) 34 35 h) implement support for security and trusted categories of xattrs 36 (requires minor protocol extension) to enable better support for SELINUX 37 38 i) Implement O_DIRECT flag on open (already supported on mount) 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 46 l) encrypted file support 47 48 m) improved stats gathering, tools (perhaps integration with nfsometer?) 49 50 n) allow setting more NTFS/SMB3 file attributes remotely (currently limited to compressed 51 file attribute via chflags) and improve user space tools for managing and 52 viewing them. 53 54 o) mount helper GUI (to simplify the various configuration options on mount) 55 56 p) autonegotiation of dialects (offering more than one dialect ie SMB3.02, 57 SMB3, SMB2.1 not just SMB3). 58 59 q) Allow mount.cifs to be more verbose in reporting errors with dialect 60 or unsupported feature errors. 61 62 r) updating cifs documentation, and user guid. 63 64 s) Addressing bugs found by running a broader set of xfstests in standard 65 file system xfstest suite. 66 67 t) split cifs and smb3 support into separate modules so legacy (and less 68 secure) CIFS dialect can be disabled in environments that don't need it 69 and simplify the code. 70 71 u) Finish up SMB3.1.1 dialect support 72 73 v) POSIX Extensions for SMB3.1.1 74 75 KNOWN BUGS 76 ==================================== 77 See http://bugzilla.samba.org - search on product "CifsVFS" for 78 current bug list. Also check http://bugzilla.kernel.org (Product = File System, Component = CIFS) 79 80 1) existing symbolic links (Windows reparse points) are recognized but 81 can not be created remotely. They are implemented for Samba and those that 82 support the CIFS Unix extensions, although earlier versions of Samba 83 overly restrict the pathnames. 84 2) follow_link and readdir code does not follow dfs junctions 85 but recognizes them 86 87 Misc testing to do 88 ================== 89 1) check out max path names and max path name components against various server 90 types. Try nested symlinks (8 deep). Return max path name in stat -f information 91 92 2) Improve xfstest's cifs enablement and adapt xfstests where needed to test 93 cifs better 94 95 3) Additional performance testing and optimization using iozone and similar - 96 there are some easy changes that can be done to parallelize sequential writes, 97 and when signing is disabled to request larger read sizes (larger than 98 negotiated size) and send larger write sizes to modern servers. 99 100 4) More exhaustively test against less common servers