xfs
[Top] [All Lists]

Re: Anyone using XFS ACLs? (fwd)

To: dcox@xxxxxxxxxx
Subject: Re: Anyone using XFS ACLs? (fwd)
From: "Nathan Scott" <nathans@xxxxxxxxxxxxxxxxxxxxxxxx>
Date: Tue, 24 Jul 2001 08:29:35 +1000
Cc: linux-xfs@xxxxxxxxxxx
In-reply-to: Danny Cox <danscox@xxxxxxxxxxxxxx> "Re: Anyone using XFS ACLs? (fwd)" (Jul 23, 7:54am)
References: <200107201833.f6KIX7H08390@xxxxxxxxxxxxxxxxxxxx> <10107231743.ZM221213@xxxxxxxxxxxxxxxxxxxxxxxx> <3B5C1086.230C3AAA@xxxxxxxxxxxxxx>
Sender: owner-linux-xfs@xxxxxxxxxxx
hi Danny,

On Jul 23,  7:54am, Danny Cox wrote:
> Subject: Re: Anyone using XFS ACLs? (fwd)
> > ...
> > - trying to understand your '-D_FILE_OFFSET_BITS=64' problem -
> > I think we do need this, I just can't understand how this was
> > failing for you (can you give more details?) - I have a rh6.2
> > system here and it seems to work for the (limited) test cases
> > we tried.
> 
>       Okay, my /usr/include/dirent.h includes <bits/dirent.h>, in which I
> see:
> 
> struct dirent
>   {
> #ifndef __USE_FILE_OFFSET64
>     __ino_t d_ino;
>     __off_t d_off;
> #else
>     __ino64_t d_ino;
>     __off64_t d_off;
> #endif
>     unsigned short int d_reclen;
>     unsigned char d_type;
>     char d_name[256];           /* We must not include limits.h! */
>   };
> 
>       Compiling chacl.c WITH -D_FILE_OFFSET_BITS=64 gets me file names of
> "".  Using gdb, I can see "..", and later on, the other file names. 
> Compiling WITHOUT -D_FILE_OFFSET_BITS=64 gets me proper file names. 
> Searching /usr/include for "__USE_FILE_OFFSET64" yields (among others),
> "features.h".  It is features.h that contains the snippet:
> 
> #if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
> # define __USE_FILE_OFFSET64    1
> #endif
> 
>       Thus, I conclude that chacl.c is using a struct dirent whose size
> doesn't match (is larger than) what readdir(3) is returning, no?
> 

There's another piece to the puzzle you may have missed - the
readdir syscall gets automagically remapped to readdir64 with
this flag ... from a very quick scan through libc, we should
be coming into the kernel via the getdents64 syscall, and we
should be using the right-sized data structure.

Do you have a reproducible test case under rh 6.2 which shows
the problem, so I could try it out?  I can't get this to fail
on any machine, with a variety of distributions.

thanks.

-- 
Nathan


<Prev in Thread] Current Thread [Next in Thread>