Re: [PATCH] move IMMUTABLE|APPEND checks to notify_change()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, Aug 09, 2006 at 11:15:12AM +0400, Dmitry Mishin wrote:
> Do you meant utimes(file, NULL)?
> But is it correct behaviour? Why then do you get -EPERM on utimes(file, smth) 
> if the file is append-only? And why do you get -EACCESS on utimes(file, 
> NULL), if this file is immutable?
> 
> Could you explain, why is it done so?

RTFPOSIX...

Short version:
	* immutable files are immutable, including metadata
	* append-only files may be touched (when you write to the end), which
means that you can touch them.  Which is what utimes(file, NULL) does.
	* you can not truncate append-only file, overwrite already written
data or set timestamps to arbitrary values.

That's where the difference between utimes(file, NULL) and utimes(file, p)
is - the former basically is a write-without-write ("touch foo") and the
latter directly assigns to timestamps.  Permissions needed for these are
obviously different.

Please, read POSIX/SuS when modifying behaviour of syscalls.  Really.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux