0001 ====
0002 TODO
0003 ====
0004
0005 Version 2.14 December 21, 2018
0006
0007 A Partial List of Missing Features
0008 ==================================
0009
0010 Contributions are welcome. There are plenty of opportunities
0011 for visible, important contributions to this module. Here
0012 is a partial list of the known problems and missing features:
0013
0014 a) SMB3 (and SMB3.1.1) missing optional features:
0015
0016 - multichannel (partially integrated), integration of multichannel with RDMA
0017 - directory leases (improved metadata caching). Currently only implemented for root dir
0018 - T10 copy offload ie "ODX" (copy chunk, and "Duplicate Extents" ioctl
0019 currently the only two server side copy mechanisms supported)
0020
0021 b) improved sparse file support (fiemap and SEEK_HOLE are implemented
0022 but additional features would be supportable by the protocol such
0023 as FALLOC_FL_COLLAPSE_RANGE and FALLOC_FL_INSERT_RANGE)
0024
0025 c) Directory entry caching relies on a 1 second timer, rather than
0026 using Directory Leases, currently only the root file handle is cached longer
0027 by leveraging Directory Leases
0028
0029 d) quota support (needs minor kernel change since quota calls otherwise
0030 won't make it to network filesystems or deviceless filesystems).
0031
0032 e) Additional use cases can be optimized to use "compounding" (e.g.
0033 open/query/close and open/setinfo/close) to reduce the number of
0034 roundtrips to the server and improve performance. Various cases
0035 (stat, statfs, create, unlink, mkdir, xattrs) already have been improved by
0036 using compounding but more can be done. In addition we could
0037 significantly reduce redundant opens by using deferred close (with
0038 handle caching leases) and better using reference counters on file
0039 handles.
0040
0041 f) Finish inotify support so kde and gnome file list windows
0042 will autorefresh (partially complete by Asser). Needs minor kernel
0043 vfs change to support removing D_NOTIFY on a file.
0044
0045 g) Add GUI tool to configure /proc/fs/cifs settings and for display of
0046 the CIFS statistics (started)
0047
0048 h) implement support for security and trusted categories of xattrs
0049 (requires minor protocol extension) to enable better support for SELINUX
0050
0051 i) Add support for tree connect contexts (see MS-SMB2) a new SMB3.1.1 protocol
0052 feature (may be especially useful for virtualization).
0053
0054 j) Create UID mapping facility so server UIDs can be mapped on a per
0055 mount or a per server basis to client UIDs or nobody if no mapping
0056 exists. Also better integration with winbind for resolving SID owners
0057
0058 k) Add tools to take advantage of more smb3 specific ioctls and features
0059 (passthrough ioctl/fsctl is now implemented in cifs.ko to allow
0060 sending various SMB3 fsctls and query info and set info calls
0061 directly from user space) Add tools to make setting various non-POSIX
0062 metadata attributes easier from tools (e.g. extending what was done
0063 in smb-info tool).
0064
0065 l) encrypted file support (currently the attribute showing the file is
0066 encrypted on the server is reported, but changing the attribute is not
0067 supported).
0068
0069 m) improved stats gathering tools (perhaps integration with nfsometer?)
0070 to extend and make easier to use what is currently in /proc/fs/cifs/Stats
0071
0072 n) Add support for claims based ACLs ("DAC")
0073
0074 o) mount helper GUI (to simplify the various configuration options on mount)
0075
0076 p) Expand support for witness protocol to allow for notification of share
0077 move, and server network adapter changes. Currently only notifications by
0078 the witness protocol for server move is supported by the Linux client.
0079
0080 q) Allow mount.cifs to be more verbose in reporting errors with dialect
0081 or unsupported feature errors. This would now be easier due to the
0082 implementation of the new mount API.
0083
0084 r) updating cifs documentation, and user guide.
0085
0086 s) Addressing bugs found by running a broader set of xfstests in standard
0087 file system xfstest suite.
0088
0089 t) split cifs and smb3 support into separate modules so legacy (and less
0090 secure) CIFS dialect can be disabled in environments that don't need it
0091 and simplify the code.
0092
0093 v) Additional testing of POSIX Extensions for SMB3.1.1
0094
0095 w) Add support for additional strong encryption types, and additional spnego
0096 authentication mechanisms (see MS-SMB2). GCM-256 is now partially implemented.
0097
0098 x) Finish support for SMB3.1.1 compression
0099
0100 Known Bugs
0101 ==========
0102
0103 See https://bugzilla.samba.org - search on product "CifsVFS" for
0104 current bug list. Also check http://bugzilla.kernel.org (Product = File System, Component = CIFS)
0105
0106 1) existing symbolic links (Windows reparse points) are recognized but
0107 can not be created remotely. They are implemented for Samba and those that
0108 support the CIFS Unix extensions, although earlier versions of Samba
0109 overly restrict the pathnames.
0110 2) follow_link and readdir code does not follow dfs junctions
0111 but recognizes them
0112
0113 Misc testing to do
0114 ==================
0115 1) check out max path names and max path name components against various server
0116 types. Try nested symlinks (8 deep). Return max path name in stat -f information
0117
0118 2) Improve xfstest's cifs/smb3 enablement and adapt xfstests where needed to test
0119 cifs/smb3 better
0120
0121 3) Additional performance testing and optimization using iozone and similar -
0122 there are some easy changes that can be done to parallelize sequential writes,
0123 and when signing is disabled to request larger read sizes (larger than
0124 negotiated size) and send larger write sizes to modern servers.
0125
0126 4) More exhaustively test against less common servers
0127
0128 5) Continue to extend the smb3 "buildbot" which does automated xfstesting
0129 against Windows, Samba and Azure currently - to add additional tests and
0130 to allow the buildbot to execute the tests faster. The URL for the
0131 buildbot is: http://smb3-test-rhel-75.southcentralus.cloudapp.azure.com
0132
0133 6) Address various coverity warnings (most are not bugs per-se, but
0134 the more warnings are addressed, the easier it is to spot real
0135 problems that static analyzers will point out in the future).
