Re: Misterious warning about file system boundaries [It's a bug, not a mystery.]

[Erik Faye-Lund <kusmabite@googlemail.com>]

On Thu, Jun 10, 2010 at 11:05 AM, Michael J Gruber
<git@drmicha.warpmail.net> wrote:
> Andreas Ericsson venit, vidit, dixit 10.06.2010 10:03:
>> On 06/09/2010 10:21 PM, Michael J Gruber wrote:
>>> Heya,
>>>
>>> now what is going on here? After upgrading to current next I get
>>>
>>> warning: working tree spans across filesystems but
>>> GIT_DISCOVERY_ACROSS_FILESYSTEM is not set.
>>>
>>> in several repos, such as my local git.git repo. That is certainly on a
>>> single file system only (ext4 over lvm over luks, all on one partition,
>>> Fedora 13). I also get this for another repo, but not for every repo. It
>>> goes away when I set the var and comes back when I don't set it, of course.
>>>
>>> Although I haven't bisected this should be due to
>>> 52b98a7 (write-index: check and warn when worktree crosses a filesystem
>>> boundary, 2010-04-04).
>>>
>>> How does the code detect a file system boundary, and where could it go
>>> wrong?
>>>
>>
>> According to the patch, it checks if the device id recorded from stat(2)
>> is the same for all files and, if not, warns about it.
>>
>> It seems that your interpretation of "one partition" differs from that
>> reported by the kernel. Why that is so, I have no idea.
>>
>
> I'm sorry, but "my interpretation"? WTF? This is all on
> /home/mjg/src/git which has no bind mounts whatsoever.
>
> I actually mixed up my / and /home situation above, /home is even
> simpler: single ext3 over luks dm device over single "real" partition.
> All of this (except for single ext3 part.) should not matter, of course.
>
> I bisected it just be sure, and it boils down to 9780e62 which is the
> commit merging 52b98a7 to next.
>
> git ls-files|xargs stat -c "%d %D" |sort|uniq
>
> gives
>
> 64772 fd04
>
> which is, in particular, 1 device only. Now, here comes funny. After
> changing write_index() to print the two ce_dev's which differ, i.e.
> printf("%d %d\n", ce->ce_dev, cache[first_valid_ent]->ce_dev);
>  I have:
>
> ./git-status -s|sort|uniq -c
> warning: working tree spans across filesystems but
> GIT_DISCOVERY_ACROSS_FILESYSTEM is not set.
>    150 64770 64772
>    662 64771 64772
>      1  M read-cache.c
>
> WTF???
>
> git reset --hard doesn't help this.
>
> rm .git/index && git reset does help.
>
<snip>
>
> Also, having git reset --index do the equivalent of "rm .git/index &&
> git reset" might be good to have.
>

Doesn't "git update-index --refresh" do the trick?

-- 
Erik "kusma" Faye-Lund