Version 2.14 December 21, 2018 A Partial List of Missing Features ================================== Contributions are welcome. There are plenty of opportunities for visible, important contributions to this module. Here is a partial list of the known problems and missing features: a) SMB3 (and SMB3.1.1) missing optional features: - multichannel (started), integration with RDMA - directory leases (improved metadata caching), started (root dir only) - T10 copy offload ie "ODX" (copy chunk, and "Duplicate Extents" ioctl currently the only two server side copy mechanisms supported) b) improved sparse file support c) Directory entry caching relies on a 1 second timer, rather than using Directory Leases, currently only the root file handle is cached longer d) quota support (needs minor kernel change since quota calls to make it to network filesystems or deviceless filesystems) e) Additional use cases where we use "compoounding" (e.g. open/query/close and open/setinfo/close) to reduce the number of roundtrips, and also open to reduce redundant opens (using deferred close and reference counts more). f) Finish inotify support so kde and gnome file list windows will autorefresh (partially complete by Asser). Needs minor kernel vfs change to support removing D_NOTIFY on a file. g) Add GUI tool to configure /proc/fs/cifs settings and for display of the CIFS statistics (started) h) implement support for security and trusted categories of xattrs (requires minor protocol extension) to enable better support for SELINUX i) Add support for tree connect contexts (see MS-SMB2) a new SMB3.1.1 protocol feature (may be especially useful for virtualization). j) Create UID mapping facility so server UIDs can be mapped on a per mount or a per server basis to client UIDs or nobody if no mapping exists. Also better integration with winbind for resolving SID owners k) Add tools to take advantage of more smb3 specific ioctls and features (passthrough ioctl/fsctl for sending various SMB3 fsctls to the server is in progress, and a passthrough query_info call is already implemented in cifs.ko to allow smb3 info levels queries to be sent from userspace) l) encrypted file support m) improved stats gathering tools (perhaps integration with nfsometer?) to extend and make easier to use what is currently in /proc/fs/cifs/Stats n) allow setting more NTFS/SMB3 file attributes remotely (currently limited to compressed file attribute via chflags) and improve user space tools for managing and viewing them. o) mount helper GUI (to simplify the various configuration options on mount) p) Add support for witness protocol (perhaps ioctl to cifs.ko from user space tool listening on witness protocol RPC) to allow for notification of share move, server failover, and server adapter changes. And also improve other failover scenarios, e.g. when client knows multiple DFS entries point to different servers, and the server we are connected to has gone down. q) Allow mount.cifs to be more verbose in reporting errors with dialect or unsupported feature errors. r) updating cifs documentation, and user guide. s) Addressing bugs found by running a broader set of xfstests in standard file system xfstest suite. t) split cifs and smb3 support into separate modules so legacy (and less secure) CIFS dialect can be disabled in environments that don't need it and simplify the code. v) POSIX Extensions for SMB3.1.1 (started, create and mkdir support added so far). w) Add support for additional strong encryption types, and additional spnego authentication mechanisms (see MS-SMB2) KNOWN BUGS ==================================== See http://bugzilla.samba.org - search on product "CifsVFS" for current bug list. Also check http://bugzilla.kernel.org (Product = File System, Component = CIFS) 1) existing symbolic links (Windows reparse points) are recognized but can not be created remotely. They are implemented for Samba and those that support the CIFS Unix extensions, although earlier versions of Samba overly restrict the pathnames. 2) follow_link and readdir code does not follow dfs junctions but recognizes them Misc testing to do ================== 1) check out max path names and max path name components against various server types. Try nested symlinks (8 deep). Return max path name in stat -f information 2) Improve xfstest's cifs/smb3 enablement and adapt xfstests where needed to test cifs/smb3 better 3) Additional performance testing and optimization using iozone and similar - there are some easy changes that can be done to parallelize sequential writes, and when signing is disabled to request larger read sizes (larger than negotiated size) and send larger write sizes to modern servers. 4) More exhaustively test against less common servers 5) Continue to extend the smb3 "buildbot" which does automated xfstesting against Windows, Samba and Azure currently - to add additional tests and to allow the buildbot to execute the tests faster. 6) Address various coverity warnings (most are not bugs per-se, but the more warnings are addressed, the easier it is to spot real problems that static analyzers will point out in the future).