Date: Mon, 26 Feb 2007 15:28:54 -0500 From: Adam Jacob Muller <freebsd-hackers@adam.gs> To: freebsd-hackers@freebsd.org Subject: FreeBSD available disk space Message-ID: <4D3F70BA-53C3-4A22-99F4-728592F2DB84@adam.gs> References: <45E33802.2020606@zend.com>
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Hello,
I've been going back and forth for a bit trying to figure out this
situation, and I am hoping that someone on this list will have some
insight :)
When using php's disk_free_space() function to determine the amount
of free space on a partition that has a negative amount of free
space, PHP returns an unreasonably large number, for example:
>> [root@cube]# php -r 'var_dump(disk_free_space("/some/partition/
>> with/negative/free/space"));'
>> float(3.7778931863E+22)
this is the comment from one of the PHP developers who has been
helping me to debug this issue:
> Well, this is actually quite interesting.
> The problem is that according to POSIX statvfs struct's field
> f_bavail must be <unsigned long>.
> But FreeBSD stores negative values in this field and I don't see
> any hint on how to detect if this is a negative value or just a
> huge positive one.
> I can of course cast it to signed long, but that would effectively
> break it on other platforms, which do conform POSIX standard and do
> not store negative values in unsigned variables.
>
> I guess FreeBSD developers might help here, since that should be a
> known problem for them.
as well as:
> I can see that libstatgrab uses #ifdef's for all *BSD flavours and
> casts f_bavail to (long long).
> Not sure if this is the correct solution, my previous suspicions
> that it may not work with really big filesystems still aply.
Thanks in advance for any insight you may have!
-Adam
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