df shows wrong size for smbfs/cifs/nfs/davfs mounted directories

[Toralf Förster]

I filed in the past several bugs regarding df and different file systems into 
several bugzilla's - every time with respect to the file system but it seems 
that df itself is the root cause.

Here are the issues:

DAVFS:
============================================================
I have created a DAV Filesystem on my machine n22 into the ramdisk, I can 
access succesfully the DAV repository via cadaver or via mount.davfs2. My 
ramdisk has 660 MB, the DAV is defined in the apache config file as:
...
    Alias /davfs /mnt/ramdisk/dav/fs
        <Location /davfs>
...

I am wondering about the displayed free disk space:
n22 ~ # df -m /mnt/ramdisk/dav/ /mnt/dav/
Filesystem           1M-blocks      Used Available Use% Mounted on
tmpfs                      660         1       660   1% /mnt/ramdisk
http://n22/davfs/         8790         0      8790   0% /mnt/dav

Why there seems to be ~8,8 GB space free whereas the whole ramdisk has only 
660 MB ?

NFS:
============================================================
Mounting a nfs dir under UML with option soft and stopping nfs - service at 
the host system, shows wrong block size, eg:

normal behaviour (n22_uml is the UML sytem, n22_tun the host) :
n22_uml ~ # df /mnt/nfs/n22_tmp
Filesystem           1K-blocks      Used Available Use% Mounted on
n22_tun:/tmp          14011712  10646784   2653184  81% /mnt/nfs/n22_tmp

Now I stop nfs at n22_tun:
n22 ~ # /etc/init.d/nfs stop
 * Stopping NFS mountd ...                                                     
                                          [ ok ]
 * Stopping NFS daemon ...                                                     
                                          [ ok ]
 * Unexporting NFS directories ...                                             
                                          [ ok ]
 * Stopping NFS statd ...           

Ang got finally under UML:
n22_uml ~ # df /mnt/nfs/n22_tmp
Filesystem           1K-blocks      Used Available Use% Mounted on
n22_tun:/tmp         77371252437321868667518976         0
77371252437321868667518976   0% /mnt/nfs/n22_tmp


Here the exports - file from the host:
n22 ~ # cat /etc/exports
# /etc/exports: NFS file systems being exported.  See exports(5).
/tmp            n22_uml(rw,sync,all_squash)

and the appropriate fstab - entry under UML:
n22_uml ~ # grep n22_tmp /etc/fstab 
n22_tun:/tmp            /mnt/nfs/n22_tmp        nfs     soft                    
0 0

SMBFS/CIFS:
============================================================
Here the results for a file system mounted as smbfs:

address@hidden ~/workspace/misc $ df /mnt/GSA/
Filesystem           1K-blocks      Used Available Use% Mounted on
//foo.bar/    660653296 -73786976293836709276 1662150484 101% /mnt/GSA
address@hidden ~/workspace/misc $ df -m /mnt/GSA/
Filesystem           1M-blocks      Used Available Use% Mounted on
//foo.bar/       645170 -72057594036949912   1623194 101% /mnt/GSA

And now the same directory re-mounted as cifs:

address@hidden ~/workspace/misc $ df /mnt/GSA/
Filesystem           1K-blocks      Used Available Use% Mounted on
//foo.bar/    660733952 -18446744072707932160 1662353408 101% /mnt/GSA
address@hidden ~/workspace/misc $ df -m /mnt/GSA/
Filesystem           1M-blocks      Used Available Use% Mounted on
//foo.bar/       645248 -18014398508503872   1623360 101% /mnt/GSA

Both have wrong negative results, but they differs in addition,too !


-- 

MfG/Regards
Toralf

pgpvZV4uf1OU1.pgp
Description: PGP signature