From: Wu Fengguang <fengguang.wu@intel.com>
To: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: Bug in BLKBSZSET/GET ioctl ?
Date: Thu, 29 Dec 2011 12:40:59 +0800 [thread overview]
Message-ID: <20111229044058.GA25524@localhost> (raw)
In-Reply-To: <4EFBEC7C.4060902@cn.fujitsu.com>
On Thu, Dec 29, 2011 at 12:28:44PM +0800, Wanlong Gao wrote:
> On 12/29/2011 12:20 PM, Wu Fengguang wrote:
>
> > On Thu, Dec 29, 2011 at 11:51:45AM +0800, Wanlong Gao wrote:
> >> Hi all:
> >>
> >> This is first reported to *libguestfs*: https://bugzilla.redhat.com/show_bug.cgi?id=624335
> >>
> >> Then, I looked into upstream util-linux and it seems nothing wrong. I'm not convinced that it's a kernel bug.
> >>
> >> produce:
> >>
> >> ---
> >> # ./util-linux/disk-utils/blockdev --getbsz /dev/sda6
> >> 4096
> >> # ./util-linux/disk-utils/blockdev --setbsz 2048 /dev/sda6
> >> # ./util-linux/disk-utils/blockdev --getbsz /dev/sda6
> >> 4096
> >> # ./util-linux/disk-utils/blockdev --setbsz 512 /dev/sda6
> >> # ./util-linux/disk-utils/blockdev --getbsz /dev/sda6
> >> 4096
> >
> > I think each blockdev invocation is working on a *new* bdev object.
>
>
> But the address of *new* bdev is the same?
> I did printk, and they all returned the same address.
Then the block size value should be reset in one of the bd_set_size()
calls in __blkdev_get().
> > You'll get consistent results if somehow keep it referenced, for
>
>
> But isn't it a bug? It seems that the setbsz has no effect?
Yeah, it does look like unexpected behavior to the end user..
Thanks,
Fengguang
next prev parent reply other threads:[~2011-12-29 4:40 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-29 3:51 Bug in BLKBSZSET/GET ioctl ? Wanlong Gao
2011-12-29 3:56 ` Wanlong Gao
2011-12-29 8:19 ` Richard W.M. Jones
2011-12-29 4:20 ` Wu Fengguang
2011-12-29 4:28 ` Wanlong Gao
2011-12-29 4:40 ` Wu Fengguang [this message]
2011-12-29 6:09 ` Wanlong Gao
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