bug#17833: coreutils 8.22 df

[Pádraig Brady]

On 07/08/2014 06:28 PM, Pádraig Brady wrote:
> On 06/25/2014 01:24 PM, Gabor Z. Papp wrote:
>> * Pádraig Brady <address@hidden>:
>>
>> | > $ cat /etc/mtab 
>> | > /dev/md0 / ext3 rw,errors=remount-ro 0 0
>> | > proc /proc proc rw,relatime 0 0
>> | > sysfs /sys sysfs rw,relatime 0 0
>> | > tmpfs /dev tmpfs rw,relatime,size=4k,mode=755 0 0
>> | > devpts /dev/pts devpts rw,relatime,mode=620 0 0
>> | > /dev/md1 /var/archive ext3 rw,errors=remount-ro 0 1
>> | > /var/archive/home /home none rw,bind 0 0
>> | > /var/archive/spool /var/spool none rw,bind 0 0
>> | > /var/archive/www /var/lib/www none rw,bind 0 0
>>
>> | Is this mtab really a link to /proc/mounts?
>>
>> No, its a standalone file.
>>
>> | That's the normal case on modern Linux distros.
>>
>> Its not a modern linux. :-)
>>
>> | > $ df-8.22 -h
>> | > Filesystem      Size  Used Avail Use% Mounted on
>> | > /dev/md0         21G  8.8G   11G  46% /
>> | > tmpfs           4.0K     0  4.0K   0% /dev
>> | > 
>> | > And where is /dev/md1 ?
>>
>> | Not sure what's going on here.
>> | Since you've compiled various versions,
>> | could you replace src/df.c in your 8.22 build dir with:
>> | 
>> http://git.sv.gnu.org/gitweb/?p=coreutils.git;a=blob_plain;f=src/df.c;hb=HEAD
>> | There have been many df changes since 8.22, so it would
>> | be good to check with the latest.
>>
>> $ /tmp/df-git -h
>> Filesystem      Size  Used Avail Use% Mounted on
>> /dev/md0         21G  9.0G   11G  47% /
>> tmpfs           4.0K     0  4.0K   0% /dev
>>
>> Same problem, /dev/md1 missing.
> 
> The missing entry is due to the bind mounts being classified as "dummy" 
> devices.
> There is code in gnulib to explicitly avoid that for bind mounts,
> however that was negated with this change:
> http://git.sv.gnu.org/gitweb/?p=gnulib.git;a=commitdiff;h=62bb7a8b
> Now that change is correct in isolation, but when combined
> with the incomplete original change, it triggered the issue.
> The attached patch should fix this up.
> 
>>
>> | > running df from coreutils 8.21 shows different result:
>> | > 
>> | > $ df-8.21 -h
>> | > Filesystem         Size  Used Avail Use% Mounted on
>> | > /dev/md0            21G  8.8G   11G  46% /
>> | > tmpfs              4.0K     0  4.0K   0% /dev
>> | > /var/archive/home  273G  244G   29G  90% /home
>> | > 
>> | > Still weird.
>>
>> | As part of the device de-duplication logic we used in 8.21
>> | we're favoring '/home' since it's shorter than '/var/archive'
>> | and thus we're using the '/var/archive/home' "device".
>>
>> | > Trying with 8.20:
>> | > 
>> | > $ df-8.20 -h
>> | > Filesystem      Size  Used Avail Use% Mounted on
>> | > /dev/md0         21G  8.8G   11G  46% /
>> | > tmpfs           4.0K     0  4.0K   0% /dev
>> | > /dev/md1        273G  244G   29G  90% /var/archive
>>
>> | I agree that this is the best output for your case.
>>
>> Right.
>>
>> | I suppose we could stat the sources in the de-duplication logic
>> | to favor real devices. I.E. stat '/var/archive/home' and '/dev/md1'
>> | in your case to favor the latter.
> 
> That's something we could still do in addition in coreutils.

The attached should handle this by giving precedence
to displaying real device nodes.

thanks,
Pádraig.

df-real-devices.patch
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