samba - Dec 2009 - User executional bit set when creating/modifying file on linux server from linux client

Whenever I create or modify a file on my cifs-mount, be it by `echo
"test" >> file` or from bash, the file mode is changed with u+x.
However, that does not happen with touch, and usign chmod u-x works as
it should.  This is very annoying...

It is a linux samba server running samba 3.0.24.  I know it's not the
latest, and if you know there was a bug fixed that can solve my problem,
I can probably get the serveradmins to upgrade it... but if it's a
config problem, that's easier...

I use linux mount.cifs version: 1.12-3.4.3

On another computer here, runnig ubuntu instead of debian, and
mount.cifs 1.12-3.3.2, modifying files does NOT set u+x!



Example:

Initial directory:

fiddur at ydalar:~/mnt/liljegren/tmp$ ls -la
totalt 0
drwxrwxr-x  2 fiddur fiddur 0  2 dec 09.51 .
drwxrwsr-x 15 fiddur fiddur 0  2 dec 09.51 ..


Creating file with touch doesn't get any u+x:
fiddur at ydalar:~/mnt/liljegren/tmp$ touch test1
fiddur at ydalar:~/mnt/liljegren/tmp$ ls -la
totalt 0
drwxrwxr-x  2 fiddur fiddur 0  2 dec 09.52 .
drwxrwsr-x 15 fiddur fiddur 0  2 dec 09.51 ..
-rw-rw-r--  1 fiddur fiddur 0  2 dec 09.52 test1


Creating a file by output redirection gives u+x:
fiddur at ydalar:~/mnt/liljegren/tmp$ echo "hej" > test2
fiddur at ydalar:~/mnt/liljegren/tmp$ ls -la
totalt 4
drwxrwxr-x  2 fiddur fiddur 0  2 dec 09.53 .
drwxrwsr-x 15 fiddur fiddur 0  2 dec 09.51 ..
-rw-rw-r--  1 fiddur fiddur 0  2 dec 09.52 test1
-rwxrw-r--  1 fiddur fiddur 4  2 dec 09.53 test2

Removing with chmod works:
fiddur at ydalar:~/mnt/liljegren/tmp$ chmod u-x test2
fiddur at ydalar:~/mnt/liljegren/tmp$ ls -la
totalt 4
drwxrwxr-x  2 fiddur fiddur 0  2 dec 09.53 .
drwxrwsr-x 15 fiddur fiddur 0  2 dec 09.51 ..
-rw-rw-r--  1 fiddur fiddur 0  2 dec 09.52 test1
-rw-rw-r--  1 fiddur fiddur 4  2 dec 09.53 test2

Modifying with appending redirection adds u+x too:
fiddur at ydalar:~/mnt/liljegren/tmp$ echo "test" >> test1
fiddur at ydalar:~/mnt/liljegren/tmp$ ls -la
totalt 8
drwxrwxr-x  2 fiddur fiddur 0  2 dec 09.53 .
drwxrwsr-x 15 fiddur fiddur 0  2 dec 09.51 ..
-rwxrw-r--  1 fiddur fiddur 5  2 dec 09.54 test1
-rw-rw-r--  1 fiddur fiddur 4  2 dec 09.53 test2



Additional info:

fiddur at ydalar:~/mnt/liljegren/tmp$ cat /proc/fs/cifs/DebugData
Display Internal CIFS Data Structures for Debugging
---------------------------------------------------
CIFS Version 1.58
Active VFS Requests: 0
Servers:
1) Name: xxx.xxx.xxx.xxx  Domain: XXXXXXXX Uses: 1 OS: Unix
    NOS: Samba 3.0.24    Capability: 0x80f3fd
    SMB session status: 1    TCP status: 1
    Local Users To Server: 1 SecMode: 0x3 Req On Wire: 0
    Shares:
    1) \\EFFIE\liljegren.devshop Mounts: 1 Type: NTFS DevInfo: 0x0
Attributes: 0x2b
PathComponentMax: 255 Status: 0x1 type: 0

    MIDs:


Regards, Fredrik

On Wed, 02 Dec 2009 10:19:52 +0100
Fredrik Liljegren <fredrik at liljegren.org> wrote:
> Whenever I create or modify a file on my cifs-mount, be it by `echo
> "test" >> file` or from bash, the file mode is changed with
u+x.
> However, that does not happen with touch, and usign chmod u-x works as
> it should.  This is very annoying...
> 
> It is a linux samba server running samba 3.0.24.  I know it's not the
> latest, and if you know there was a bug fixed that can solve my problem,
> I can probably get the serveradmins to upgrade it... but if it's a
> config problem, that's easier...
> 
> I use linux mount.cifs version: 1.12-3.4.3
> 
> On another computer here, runnig ubuntu instead of debian, and
> mount.cifs 1.12-3.3.2, modifying files does NOT set u+x!
> 
> 
> 
> Example:
> 
> Initial directory:
> 
> fiddur at ydalar:~/mnt/liljegren/tmp$ ls -la
> totalt 0
> drwxrwxr-x  2 fiddur fiddur 0  2 dec 09.51 .
> drwxrwsr-x 15 fiddur fiddur 0  2 dec 09.51 ..
> 
> 
> Creating file with touch doesn't get any u+x:
> fiddur at ydalar:~/mnt/liljegren/tmp$ touch test1
> fiddur at ydalar:~/mnt/liljegren/tmp$ ls -la
> totalt 0
> drwxrwxr-x  2 fiddur fiddur 0  2 dec 09.52 .
> drwxrwsr-x 15 fiddur fiddur 0  2 dec 09.51 ..
> -rw-rw-r--  1 fiddur fiddur 0  2 dec 09.52 test1
> 
> 
> Creating a file by output redirection gives u+x:
> fiddur at ydalar:~/mnt/liljegren/tmp$ echo "hej" > test2
> fiddur at ydalar:~/mnt/liljegren/tmp$ ls -la
> totalt 4
> drwxrwxr-x  2 fiddur fiddur 0  2 dec 09.53 .
> drwxrwsr-x 15 fiddur fiddur 0  2 dec 09.51 ..
> -rw-rw-r--  1 fiddur fiddur 0  2 dec 09.52 test1
> -rwxrw-r--  1 fiddur fiddur 4  2 dec 09.53 test2
> 
> Removing with chmod works:
> fiddur at ydalar:~/mnt/liljegren/tmp$ chmod u-x test2
> fiddur at ydalar:~/mnt/liljegren/tmp$ ls -la
> totalt 4
> drwxrwxr-x  2 fiddur fiddur 0  2 dec 09.53 .
> drwxrwsr-x 15 fiddur fiddur 0  2 dec 09.51 ..
> -rw-rw-r--  1 fiddur fiddur 0  2 dec 09.52 test1
> -rw-rw-r--  1 fiddur fiddur 4  2 dec 09.53 test2
> 
> Modifying with appending redirection adds u+x too:
> fiddur at ydalar:~/mnt/liljegren/tmp$ echo "test" >> test1
> fiddur at ydalar:~/mnt/liljegren/tmp$ ls -la
> totalt 8
> drwxrwxr-x  2 fiddur fiddur 0  2 dec 09.53 .
> drwxrwsr-x 15 fiddur fiddur 0  2 dec 09.51 ..
> -rwxrw-r--  1 fiddur fiddur 5  2 dec 09.54 test1
> -rw-rw-r--  1 fiddur fiddur 4  2 dec 09.53 test2
> 
> 
> 
> Additional info:
> 
> fiddur at ydalar:~/mnt/liljegren/tmp$ cat /proc/fs/cifs/DebugData
> Display Internal CIFS Data Structures for Debugging
> ---------------------------------------------------
> CIFS Version 1.58
> Active VFS Requests: 0
> Servers:
> 1) Name: xxx.xxx.xxx.xxx  Domain: XXXXXXXX Uses: 1 OS: Unix
>     NOS: Samba 3.0.24    Capability: 0x80f3fd
>     SMB session status: 1    TCP status: 1
>     Local Users To Server: 1 SecMode: 0x3 Req On Wire: 0
>     Shares:
>     1) \\EFFIE\liljegren.devshop Mounts: 1 Type: NTFS DevInfo: 0x0
> Attributes: 0x2b
> PathComponentMax: 255 Status: 0x1 type: 0
> 
>     MIDs:
> 
 

That is strange, I'm not aware of anything in cifs that would change inode
permissions on a write call. Some questions:

What mount options are you using?

Does the server have any special "create mode" or "create
mask" type
settings that might affect the mode assigned to the inode?

What kernel is this client running?

What kernel is the ubuntu client running?

It might be interesting to see a wire capture while recreating this.
Instructions on doing that are here:

http://wiki.samba.org/index.php/LinuxCIFS_troubleshooting

If you like, you can send the capture to me directly and I'll have a
look.

-- 
Jeff Layton <jlayton at samba.org>

On Wed, 02 Dec 2009 16:53:53 +0100
Fredrik Liljegren <fredrik at liljegren.org> wrote:
> Jeff Layton wrote:
> > I was actually more interested in a wire capture, but this tells me
> > something too...
> >
> > The logs here indicate that unix extensions were in effect. With that,
> > the file_mode and dir_mode should really never have any effect. I have
> > a feeling that these are bugs that existed prior to the big overhaul
of
> > inode handling that went into 2.6.31.
> >
> > Is there a way for you to test a more recent kernel here (something
> > 2.6.31 or 2.6.32-ish)?
> >   
> I upgraded to 2.6.31-1-amd64 (debian sid), but that didn't change
> anything.  Without file_mode in the mount, a simple file change still
> adds u+x.
> 
> /F
> 
> PS: I tried without nodfs, but then I get permission denied trying to
> change mode with chmod u-x...
> 
(adding samba list back to cc list)

I see where we do send the mnt_file_mode in a posix open call if we're
opening an existing file. The server should ignore that however. Even
if it didn't, 3.0.24 probably has broken posix open calls for existing
files so I'm not sure it would use that codepath anyway.

This sounds really strange. Could you get a wire capture so we can see
what's happening there?

It might also be best to open a bug at bugzilla.samba.org as that would
give us a better forum for tracking this issue. If you do that, please
add me to the cc list (or email me with the bug number and I'll add
myself).

Thanks,
-- 
Jeff Layton <jlayton at samba.org>