Based on kernel version 3.16. Page generated on 2014-08-06 21:39 EST.
1 Version 1.53 May 20, 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) fix NTLMv2 signing when two mounts with different users to same 24 server. 25 26 f) Directory entry caching relies on a 1 second timer, rather than 27 using FindNotify or equivalent. - (started) 28 29 g) quota support (needs minor kernel change since quota calls 30 to make it to network filesystems or deviceless filesystems) 31 32 h) investigate sync behavior (including syncpage) and check 33 for proper behavior of intr/nointr 34 35 i) improve support for very old servers (OS/2 and Win9x for example) 36 Including support for changing the time remotely (utimes command). 37 38 j) hook lower into the sockets api (as NFS/SunRPC does) to avoid the 39 extra copy in/out of the socket buffers in some cases. 40 41 k) Better optimize open (and pathbased setfilesize) to reduce the 42 oplock breaks coming from windows srv. Piggyback identical file 43 opens on top of each other by incrementing reference count rather 44 than resending (helps reduce server resource utilization and avoid 45 spurious oplock breaks). 46 47 l) Improve performance of readpages by sending more than one read 48 at a time when 8 pages or more are requested. In conjuntion 49 add support for async_cifs_readpages. 50 51 m) Add support for storing symlink info to Windows servers 52 in the Extended Attribute format their SFU clients would recognize. 53 54 n) Finish fcntl D_NOTIFY support so kde and gnome file list windows 55 will autorefresh (partially complete by Asser). Needs minor kernel 56 vfs change to support removing D_NOTIFY on a file. 57 58 o) Add GUI tool to configure /proc/fs/cifs settings and for display of 59 the CIFS statistics (started) 60 61 p) implement support for security and trusted categories of xattrs 62 (requires minor protocol extension) to enable better support for SELINUX 63 64 q) Implement O_DIRECT flag on open (already supported on mount) 65 66 r) Create UID mapping facility so server UIDs can be mapped on a per 67 mount or a per server basis to client UIDs or nobody if no mapping 68 exists. This is helpful when Unix extensions are negotiated to 69 allow better permission checking when UIDs differ on the server 70 and client. Add new protocol request to the CIFS protocol 71 standard for asking the server for the corresponding name of a 72 particular uid. 73 74 s) Add support for CIFS Unix and also the newer POSIX extensions to the 75 server side for Samba 4. 76 77 t) In support for OS/2 (LANMAN 1.2 and LANMAN2.1 based SMB servers) 78 need to add ability to set time to server (utimes command) 79 80 u) DOS attrs - returned as pseudo-xattr in Samba format (check VFAT and NTFS for this too) 81 82 v) mount check for unmatched uids 83 84 w) Add support for new vfs entry point for fallocate 85 86 x) Fix Samba 3 server to handle Linux kernel aio so dbench with lots of 87 processes can proceed better in parallel (on the server) 88 89 y) Fix Samba 3 to handle reads/writes over 127K (and remove the cifs mount 90 restriction of wsize max being 127K) 91 92 KNOWN BUGS (updated April 24, 2007) 93 ==================================== 94 See http://bugzilla.samba.org - search on product "CifsVFS" for 95 current bug list. 96 97 1) existing symbolic links (Windows reparse points) are recognized but 98 can not be created remotely. They are implemented for Samba and those that 99 support the CIFS Unix extensions, although earlier versions of Samba 100 overly restrict the pathnames. 101 2) follow_link and readdir code does not follow dfs junctions 102 but recognizes them 103 3) create of new files to FAT partitions on Windows servers can 104 succeed but still return access denied (appears to be Windows 105 server not cifs client problem) and has not been reproduced recently. 106 NTFS partitions do not have this problem. 107 4) Unix/POSIX capabilities are reset after reconnection, and affect 108 a few fields in the tree connection but we do do not know which 109 superblocks to apply these changes to. We should probably walk 110 the list of superblocks to set these. Also need to check the 111 flags on the second mount to the same share, and see if we 112 can do the same trick that NFS does to remount duplicate shares. 113 114 Misc testing to do 115 ================== 116 1) check out max path names and max path name components against various server 117 types. Try nested symlinks (8 deep). Return max path name in stat -f information 118 119 2) Modify file portion of ltp so it can run against a mounted network 120 share and run it against cifs vfs in automated fashion. 121 122 3) Additional performance testing and optimization using iozone and similar - 123 there are some easy changes that can be done to parallelize sequential writes, 124 and when signing is disabled to request larger read sizes (larger than 125 negotiated size) and send larger write sizes to modern servers. 126 127 4) More exhaustively test against less common servers. More testing 128 against Windows 9x, Windows ME servers.