Re: Problems with vfs / ftpfs

["Andrew V. Samoilov" <sav it efp com ua>]

Walery Studennikov wrote:
> 1.
>
> Strange things happens when you try to upload file to
> ftp when the file with the same name already exists there.
> At first existing file (which must be overwritten)
> is DOWNLOADED to the local machine and only after that
> the local file is uploaded to ftp.
> So, WHY to download the remote file (increasing incomming traffic
> and wasting time) before owerwrite it?
> 2.
>
> Why when copying local files to ftp, those files are copied
> to /tmp at first and only after that they are copied to ftp.
> WHY do we do this unnecessary operation?

When file is opened there is no way to know, will the read() system call
used, because O_RDONLY is 0.  So, for performance reasons VFS layer makes
local temporary copy of this file, and then all of data is read and
written from/to this copy.  And this file is uploaded only in mc_close().

Possible solutions are:

1) get local copy on first read call only (Brr)
2) provide something like O_LINEAR flag (As far as I remember there were 
some problems
   with this options and Pavel Machek disabled this one.)  Another 
solution is an own
   flag for mc_open, but we need to be sure it and its value are used 
nowhere in known
   Universe for open system call.
3) use directly vfs_s_data.file_store in copy_file_file/move_file_file 
if destination is
   not on local filesystem.

> 3.
>
> An ancient problem:
>
> Cannot chmod target file "/mnt/d/file.txt"
> Operation not permitted (1)
>
> Occures when copying to vfat filesystems, but not only.
> If we need to copy MANY files, we have to WASTE TIME
> and press OK many times.
> You can say "use cp -rf". Yes, but with "cp -rf"
> I can't use mc vfs.
>
> May be we will introduce a run-time option
> to disable whose annoying warnings?
> I mean to not disable them entirely,
> but just print those warnings on the hintbar.
>
> Also when we MOVE files and this warning occurs,
> the source file is not removed.
> Yes, it is wise in most cases, but maybe
> also provide an option to fix this?

You can unset "preserve Attributes" when copy.
In January, 2002, I sent a patch to enable this feature for Move operation.

Regards,
Andrew V. Samoilov.