Messages in this thread | | | From | "Albert D. Cahalan" <> | Subject | Re: File copy system call proposal | Date | Mon, 10 Dec 2001 00:44:54 -0500 (EST) |
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Daniel Phillips writes:
> There's some merit to this idea. As Peter pointed out, > an in-kernel cp isn' needed: mmap+write does the job. > The question is, how to avoid the copy_from_user and > double caching of data?
No, mmap+write does not do the job. SMB file servers have a remote copy operation. There shouldn't be any need to pull data over the network only to push it back again!
The user-space copy operation is also highly likely to lose stuff that the kernel would know about:
extended attributes (IRIX, OS/2, NT) forks / extra streams (MacOS, NT) creation time stamp (Microsoft: not ctime or mtime) author (GNU HURD: person who created the file) file type (MacOS) creator app (MacOS) unique ID (Win2K) mandatory access control data (Trusted Foo) non-UNIX permission bits (every other OS) ACLs (NFSv4, NT, Solaris...) translator (HURD) trustees (NetWare) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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