Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1====
2TODO
3====
4
5As of 6.7 kernel. See https://wiki.samba.org/index.php/LinuxCIFSKernel
6for list of features added by release
7
8A Partial List of Missing Features
9==================================
10
11Contributions are welcome. There are plenty of opportunities
12for visible, important contributions to this module. Here
13is a partial list of the known problems and missing features:
14
15a) SMB3 (and SMB3.1.1) missing optional features:
16 multichannel performance optimizations, algorithmic channel selection,
17 directory leases optimizations,
18 support for faster packet signing (GMAC),
19 support for compression over the network,
20 T10 copy offload ie "ODX" (copy chunk, and "Duplicate Extents" ioctl
21 are currently the only two server side copy mechanisms supported)
22
23b) Better optimized compounding and error handling for sparse file support,
24 perhaps addition of new optional SMB3.1.1 fsctls to make collapse range
25 and insert range more atomic
26
27c) Support for SMB3.1.1 over QUIC (and perhaps other socket based protocols
28 like SCTP)
29
30d) quota support (needs minor kernel change since quota calls otherwise
31 won't make it to network filesystems or deviceless filesystems).
32
33e) Additional use cases can be optimized to use "compounding" (e.g.
34 open/query/close and open/setinfo/close) to reduce the number of
35 roundtrips to the server and improve performance. Various cases
36 (stat, statfs, create, unlink, mkdir, xattrs) already have been improved by
37 using compounding but more can be done. In addition we could
38 significantly reduce redundant opens by using deferred close (with
39 handle caching leases) and better using reference counters on file
40 handles.
41
42f) Finish inotify support so kde and gnome file list windows
43 will autorefresh (partially complete by Asser). Needs minor kernel
44 vfs change to support removing D_NOTIFY on a file.
45
46g) Add GUI tool to configure /proc/fs/cifs settings and for display of
47 the CIFS statistics (started)
48
49h) implement support for security and trusted categories of xattrs
50 (requires minor protocol extension) to enable better support for SELINUX
51
52i) Add support for tree connect contexts (see MS-SMB2) a new SMB3.1.1 protocol
53 feature (may be especially useful for virtualization).
54
55j) Create UID mapping facility so server UIDs can be mapped on a per
56 mount or a per server basis to client UIDs or nobody if no mapping
57 exists. Also better integration with winbind for resolving SID owners
58
59k) Add tools to take advantage of more smb3 specific ioctls and features
60 (passthrough ioctl/fsctl is now implemented in cifs.ko to allow
61 sending various SMB3 fsctls and query info and set info calls
62 directly from user space) Add tools to make setting various non-POSIX
63 metadata attributes easier from tools (e.g. extending what was done
64 in smb-info tool).
65
66l) encrypted file support (currently the attribute showing the file is
67 encrypted on the server is reported, but changing the attribute is not
68 supported).
69
70m) improved stats gathering tools (perhaps integration with nfsometer?)
71 to extend and make easier to use what is currently in /proc/fs/cifs/Stats
72
73n) Add support for claims based ACLs ("DAC")
74
75o) mount helper GUI (to simplify the various configuration options on mount)
76
77p) Expand support for witness protocol to allow for notification of share
78 move, and server network adapter changes. Currently only notifications by
79 the witness protocol for server move is supported by the Linux client.
80
81q) Allow mount.cifs to be more verbose in reporting errors with dialect
82 or unsupported feature errors. This would now be easier due to the
83 implementation of the new mount API.
84
85r) updating cifs documentation, and user guide.
86
87s) Addressing bugs found by running a broader set of xfstests in standard
88 file system xfstest suite.
89
90t) split cifs and smb3 support into separate modules so legacy (and less
91 secure) CIFS dialect can be disabled in environments that don't need it
92 and simplify the code.
93
94v) Additional testing of POSIX Extensions for SMB3.1.1
95
96w) Support for the Mac SMB3.1.1 extensions to improve interop with Apple servers
97
98x) Support for additional authentication options (e.g. IAKERB, peer-to-peer
99 Kerberos, SCRAM and others supported by existing servers)
100
101y) Improved tracing, more eBPF trace points, better scripts for performance
102 analysis
103
104Known Bugs
105==========
106
107See https://bugzilla.samba.org - search on product "CifsVFS" for
108current bug list. Also check http://bugzilla.kernel.org (Product = File System, Component = CIFS)
109and xfstest results e.g. https://wiki.samba.org/index.php/Xfstest-results-smb3
110
111Misc testing to do
112==================
1131) check out max path names and max path name components against various server
114 types. Try nested symlinks (8 deep). Return max path name in stat -f information
115
1162) Improve xfstest's cifs/smb3 enablement and adapt xfstests where needed to test
117 cifs/smb3 better
118
1193) Additional performance testing and optimization using iozone and similar -
120 there are some easy changes that can be done to parallelize sequential writes,
121 and when signing is disabled to request larger read sizes (larger than
122 negotiated size) and send larger write sizes to modern servers.
123
1244) More exhaustively test against less common servers
125
1265) Continue to extend the smb3 "buildbot" which does automated xfstesting
127 against Windows, Samba and Azure currently - to add additional tests and
128 to allow the buildbot to execute the tests faster. The URL for the
129 buildbot is: http://smb3-test-rhel-75.southcentralus.cloudapp.azure.com
130
1316) Address various coverity warnings (most are not bugs per-se, but
132 the more warnings are addressed, the easier it is to spot real
133 problems that static analyzers will point out in the future).