Re: test osd on zfs

From: Stefan Priebe <s.priebe@profihost.ag>
To: Yehuda Sadeh <yehuda@inktank.com>
Cc: Brian Behlendorf <behlendorf1@llnl.gov>,
	Sage Weil <sage@inktank.com>,
	Jeff Mitchell <jeffrey.mitchell@gmail.com>,
	Henry C Chang <henry.cy.chang@gmail.com>,
	Aleksey Leonov <aleonov@nazarianin.com>,
	ceph-devel <ceph-devel@vger.kernel.org>
Subject: Re: test osd on zfs
Date: Wed, 17 Apr 2013 21:09:02 +0200	[thread overview]
Message-ID: <516EF34E.5000000@profihost.ag> (raw)
In-Reply-To: <CABBk=J90_TB2hNH=rh6b=iO+=DRQoHPCiTqDP=X+ygyM0xoeVw@mail.gmail.com>

Sorry to disturb, but what is the raeson / advantage of using zfs for ceph?

Greets,
Stefan
Am 17.04.2013 21:07, schrieb Yehuda Sadeh:
> On Wed, Apr 17, 2013 at 11:57 AM, Brian Behlendorf <behlendorf1@llnl.gov> wrote:
>>
>> Here's a patch for the ERANGE error (lightly tested).  Sage's patch looks
>> good but only covers one of two code paths for xattrs.  With zfs they may
>> either be stored as a system attribute which is usually close to the dnode
>> on disk (zfs set xattr=sa pool/dataset).  Or they may be stored in their own
>> object which is how it's implemented on Solaris (zfs set xattr=on
>> pool/dataset).  The second method is still the default for compatibility
>> reasons even though it's slower.  Sage's patch only covered the SA case.
>>
>>
>>> Well, looking at the code again it's not going to work, as setxattr is
>>> going to fail with ERANGE.
>>
>> Why?  We support an arbitrary number of maximum sized xattrs (65536). What
>> am I missing here?
>>
>> Incidentally, does anybody know of an good xattr test suite we could add to
>> our regression tests?
>>
>> Thanks,
>> Brian
>>
>> diff --git a/module/zfs/zpl_xattr.c b/module/zfs/zpl_xattr.c
>> index c03764f..9f4d63c 100644
>> --- a/module/zfs/zpl_xattr.c
>> +++ b/module/zfs/zpl_xattr.c
>> @@ -225,6 +225,11 @@ zpl_xattr_get_dir(struct inode *ip, const char *name,
>> void *value,
>>                  goto out;
>>          }
>>
>> +       if (size < i_size_read(xip)) {
>> +               error = -ERANGE;
>> +               goto out;
>> +       }
>> +
>>          error = zpl_read_common(xip, value, size, 0, UIO_SYSSPACE, 0, cr);
>>   out:
>>          if (xip)
>> @@ -263,7 +268,10 @@ zpl_xattr_get_sa(struct inode *ip, const char *name,
>> void *value, size_t size)
>>          if (!size)
>>                  return (nv_size);
>>
>> -       memcpy(value, nv_value, MIN(size, nv_size));
>>
>> +       if (size < nv_size)
>> +               return (-ERANGE);
>
> Note, that zpl_xattr_get_sa() is called by __zpl_xattr_get() which can
> also be called by zpl_xattr_get() to test for xattr existence. So it
> needs to make sure that zpl_xattr_set() doesn't fail if getting
> -ERANGE.
>
>> +
>> +       memcpy(value, nv_value, size);
>>
>>          return (MIN(size, nv_size));
>
> No need for MIN() here.
>
>
> Yehuda
> --
> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>