Re: [PATCH COW] sys_copyfile
From: Jörn Engel (joern_at_wohnheim.fh-wedel.de)
Date: 04/27/04
- Previous message: Clay Haapala: "[PATCH] lib/libcrc32c, revised 040427"
- In reply to: Steve French: "Re: [PATCH COW] sys_copyfile"
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Date: Tue, 27 Apr 2004 21:55:03 +0200 To: Steve French <smfltc@us.ibm.com>
On Tue, 27 April 2004 14:46:19 -0500, Steve French wrote:
> On Tue, 2004-04-27 at 11:42, Jörn Engel wrote:
>
> > Shouldn't it be rather
> >
> > if (old_nd->dentry->d_inode->i_op->copy)
> > return old_nd->dentry->d_inode->i_op->copy(old_nd->dentry,
> > mode, new_dentry);
> >
> > or something similar? The copy() effectively replaces the complete
> > create/sendfile/possibly-unlink series.
>
> In some network protocols the client does not know whether the server
> wants to support copy operation or not (perhaps if the files were on
> different server partitions the server might return an error e.g), in
> those cases the filesystem client could return error not supported or
> equivalent and the remainder of your function is executed doing the copy
> the harder way (open/read/close create/write/close) but still faster a
> few percent faster than before your patch.
Makes sense. Then something like
if (old_nd->dentry->d_inode->i_op->copy) {
ret = old_nd->dentry->d_inode->i_op->copy(old_nd->dentry,
mode, new_dentry);
if (ret != -ENOSYS)
return ret;
}
Also, would it be possible to do essentially the same with sendfile()?
That should bring roughly the same speedup for disk based filesystems,
and would be a bit more general.
Jörn
-- Don't patch bad code, rewrite it. -- Kernigham and Pike, according to Rusty - 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/
- Previous message: Clay Haapala: "[PATCH] lib/libcrc32c, revised 040427"
- In reply to: Steve French: "Re: [PATCH COW] sys_copyfile"
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
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