104 lines
		
	
	
	
		
			4 KiB
			
		
	
	
	
		
			Text
		
	
	
	
	
	
			
		
		
	
	
			104 lines
		
	
	
	
		
			4 KiB
			
		
	
	
	
		
			Text
		
	
	
	
	
	
Version 2.03 August 1, 2014
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A Partial List of Missing Features
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==================================
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Contributions are welcome.  There are plenty of opportunities
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for visible, important contributions to this module.  Here
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is a partial list of the known problems and missing features:
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a) SMB3 (and SMB3.02) missing optional features:
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   - RDMA
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   - multichannel (started)
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   - directory leases (improved metadata caching)
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   - T10 copy offload (copy chunk is only mechanism supported)
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   - encrypted shares
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b) improved sparse file support
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c) Directory entry caching relies on a 1 second timer, rather than
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using FindNotify or equivalent.  - (started)
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d) quota support (needs minor kernel change since quota calls
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to make it to network filesystems or deviceless filesystems)
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e) improve support for very old servers (OS/2 and Win9x for example)
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Including support for changing the time remotely (utimes command).
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f) hook lower into the sockets api (as NFS/SunRPC does) to avoid the
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extra copy in/out of the socket buffers in some cases.
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g) Better optimize open (and pathbased setfilesize) to reduce the
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oplock breaks coming from windows srv.  Piggyback identical file
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opens on top of each other by incrementing reference count rather
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than resending (helps reduce server resource utilization and avoid
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spurious oplock breaks).
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h) Add support for storing symlink info to Windows servers
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in the Extended Attribute format their SFU clients would recognize.
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i) Finish inotify support so kde and gnome file list windows
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will autorefresh (partially complete by Asser). Needs minor kernel
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vfs change to support removing D_NOTIFY on a file.   
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j) Add GUI tool to configure /proc/fs/cifs settings and for display of
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the CIFS statistics (started)
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k) implement support for security and trusted categories of xattrs
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(requires minor protocol extension) to enable better support for SELINUX
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l) Implement O_DIRECT flag on open (already supported on mount)
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m) Create UID mapping facility so server UIDs can be mapped on a per
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mount or a per server basis to client UIDs or nobody if no mapping
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exists.  This is helpful when Unix extensions are negotiated to
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allow better permission checking when UIDs differ on the server
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and client.  Add new protocol request to the CIFS protocol 
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standard for asking the server for the corresponding name of a
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particular uid.
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n) DOS attrs - returned as pseudo-xattr in Samba format (check VFAT and NTFS for this too)
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o) mount check for unmatched uids
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p) Add support for new vfs entry point for fallocate
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q) Add tools to take advantage of cifs/smb3 specific ioctls and features
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such as "CopyChunk" (fast server side file copy)
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r) encrypted file support
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s) improved stats gathering, tools (perhaps integration with nfsometer?)
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t) allow setting more NTFS/SMB3 file attributes remotely (currently limited to compressed
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file attribute via chflags)
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u) mount helper GUI (to simplify the various configuration options on mount)
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KNOWN BUGS
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====================================
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See http://bugzilla.samba.org - search on product "CifsVFS" for
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current bug list.  Also check http://bugzilla.kernel.org (Product = File System, Component = CIFS)
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1) existing symbolic links (Windows reparse points) are recognized but
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can not be created remotely. They are implemented for Samba and those that
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support the CIFS Unix extensions, although earlier versions of Samba
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overly restrict the pathnames.
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2) follow_link and readdir code does not follow dfs junctions
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but recognizes them
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Misc testing to do
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==================
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1) check out max path names and max path name components against various server
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types. Try nested symlinks (8 deep). Return max path name in stat -f information
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2) Improve xfstest's cifs enablement and adapt xfstests where needed to test
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cifs better
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3) Additional performance testing and optimization using iozone and similar - 
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there are some easy changes that can be done to parallelize sequential writes,
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and when signing is disabled to request larger read sizes (larger than 
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negotiated size) and send larger write sizes to modern servers.
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4) More exhaustively test against less common servers
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