| 1 | Version 1.52 January 3, 2008 |
| 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) Support for SecurityDescriptors(Windows/CIFS ACLs) for chmod/chgrp/chown |
| 11 | so that these operations can be supported to Windows servers |
| 12 | |
| 13 | b) Mapping POSIX ACLs (and eventually NFSv4 ACLs) to CIFS |
| 14 | SecurityDescriptors |
| 15 | |
| 16 | c) Better pam/winbind integration (e.g. to handle uid mapping |
| 17 | better) |
| 18 | |
| 19 | d) Cleanup now unneeded SessSetup code in |
| 20 | fs/cifs/connect.c and add back in NTLMSSP code if any servers |
| 21 | need it |
| 22 | |
| 23 | e) ms-dfs and ms-dfs host name resolution cleanup |
| 24 | |
| 25 | f) fix NTLMv2 signing when two mounts with different users to same |
| 26 | server. |
| 27 | |
| 28 | g) Directory entry caching relies on a 1 second timer, rather than |
| 29 | using FindNotify or equivalent. - (started) |
| 30 | |
| 31 | h) quota support (needs minor kernel change since quota calls |
| 32 | to make it to network filesystems or deviceless filesystems) |
| 33 | |
| 34 | i) investigate sync behavior (including syncpage) and check |
| 35 | for proper behavior of intr/nointr |
| 36 | |
| 37 | j) hook lower into the sockets api (as NFS/SunRPC does) to avoid the |
| 38 | extra copy in/out of the socket buffers in some cases. |
| 39 | |
| 40 | k) Better optimize open (and pathbased setfilesize) to reduce the |
| 41 | oplock breaks coming from windows srv. Piggyback identical file |
| 42 | opens on top of each other by incrementing reference count rather |
| 43 | than resending (helps reduce server resource utilization and avoid |
| 44 | spurious oplock breaks). |
| 45 | |
| 46 | l) Improve performance of readpages by sending more than one read |
| 47 | at a time when 8 pages or more are requested. In conjuntion |
| 48 | add support for async_cifs_readpages. |
| 49 | |
| 50 | m) Add support for storing symlink info to Windows servers |
| 51 | in the Extended Attribute format their SFU clients would recognize. |
| 52 | |
| 53 | n) Finish fcntl D_NOTIFY support so kde and gnome file list windows |
| 54 | will autorefresh (partially complete by Asser). Needs minor kernel |
| 55 | vfs change to support removing D_NOTIFY on a file. |
| 56 | |
| 57 | o) Add GUI tool to configure /proc/fs/cifs settings and for display of |
| 58 | the CIFS statistics (started) |
| 59 | |
| 60 | p) implement support for security and trusted categories of xattrs |
| 61 | (requires minor protocol extension) to enable better support for SELINUX |
| 62 | |
| 63 | q) Implement O_DIRECT flag on open (already supported on mount) |
| 64 | |
| 65 | r) Create UID mapping facility so server UIDs can be mapped on a per |
| 66 | mount or a per server basis to client UIDs or nobody if no mapping |
| 67 | exists. This is helpful when Unix extensions are negotiated to |
| 68 | allow better permission checking when UIDs differ on the server |
| 69 | and client. Add new protocol request to the CIFS protocol |
| 70 | standard for asking the server for the corresponding name of a |
| 71 | particular uid. |
| 72 | |
| 73 | s) Add support for CIFS Unix and also the newer POSIX extensions to the |
| 74 | server side for Samba 4. |
| 75 | |
| 76 | t) In support for OS/2 (LANMAN 1.2 and LANMAN2.1 based SMB servers) |
| 77 | need to add ability to set time to server (utimes command) |
| 78 | |
| 79 | u) DOS attrs - returned as pseudo-xattr in Samba format (check VFAT and NTFS for this too) |
| 80 | |
| 81 | v) mount check for unmatched uids |
| 82 | |
| 83 | w) Add support for new vfs entry points for setlease and fallocate |
| 84 | |
| 85 | x) Fix Samba 3 server to handle Linux kernel aio so dbench with lots of |
| 86 | processes can proceed better in parallel (on the server) |
| 87 | |
| 88 | y) Fix Samba 3 to handle reads/writes over 127K (and remove the cifs mount |
| 89 | restriction of wsize max being 127K) |
| 90 | |
| 91 | KNOWN BUGS (updated April 24, 2007) |
| 92 | ==================================== |
| 93 | See http://bugzilla.samba.org - search on product "CifsVFS" for |
| 94 | current bug list. |
| 95 | |
| 96 | 1) existing symbolic links (Windows reparse points) are recognized but |
| 97 | can not be created remotely. They are implemented for Samba and those that |
| 98 | support the CIFS Unix extensions, although earlier versions of Samba |
| 99 | overly restrict the pathnames. |
| 100 | 2) follow_link and readdir code does not follow dfs junctions |
| 101 | but recognizes them |
| 102 | 3) create of new files to FAT partitions on Windows servers can |
| 103 | succeed but still return access denied (appears to be Windows |
| 104 | server not cifs client problem) and has not been reproduced recently. |
| 105 | NTFS partitions do not have this problem. |
| 106 | 4) Unix/POSIX capabilities are reset after reconnection, and affect |
| 107 | a few fields in the tree connection but we do do not know which |
| 108 | superblocks to apply these changes to. We should probably walk |
| 109 | the list of superblocks to set these. Also need to check the |
| 110 | flags on the second mount to the same share, and see if we |
| 111 | can do the same trick that NFS does to remount duplicate shares. |
| 112 | |
| 113 | Misc testing to do |
| 114 | ================== |
| 115 | 1) check out max path names and max path name components against various server |
| 116 | types. Try nested symlinks (8 deep). Return max path name in stat -f information |
| 117 | |
| 118 | 2) Modify file portion of ltp so it can run against a mounted network |
| 119 | share and run it against cifs vfs in automated fashion. |
| 120 | |
| 121 | 3) Additional performance testing and optimization using iozone and similar - |
| 122 | there are some easy changes that can be done to parallelize sequential writes, |
| 123 | and when signing is disabled to request larger read sizes (larger than |
| 124 | negotiated size) and send larger write sizes to modern servers. |
| 125 | |
| 126 | 4) More exhaustively test against less common servers. More testing |
| 127 | against Windows 9x, Windows ME servers. |
| 128 | |