From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 7 Nov 2000 17:45:04 +0100 From: Andrea Arcangeli Subject: [linux-lvm] Re: LVM 2.2 snapshot bug Message-ID: <20001107174504.A5834@inspiron.suse.de> References: <20001107142152.G1276@inspiron.random> Mime-Version: 1.0 Content-Disposition: inline In-Reply-To: ; from riel@conectiva.com.br on Tue, Nov 07, 2000 at 03:56:59PM +0100 Sender: owner-linux-lvm Errors-To: owner-linux-lvm List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Rik van Riel Cc: linux-lvm@msede.com, marcelo@conectiva.com.br, "Stephen C. Tweedie" On Tue, Nov 07, 2000 at 03:56:59PM +0100, Rik van Riel wrote: > That's a bit much to type in by hand ... and it's basically > kjournald being confused by all its writes failing on a RW > block device. So ext3 will crash also if I/O errors happen during the log reply. The Oopses seems due an _ext3_ bug (not due the missing ro_bits in the LVM snapshot) as far I can tell. > Indeed this is the case. When the block device is read-write > (the is_read_only(blk_dev) is non-true) it tries to replay > the log, even for a read-only mounted FS. Ok, I agree it's a minor LVM bug, but again I can't see how that minor bug can cause oopses and I think setting ro_bits won't fix the real bug but it will only hide it. BTW, LVM also internally checks for the LV_WRITE bitflag during open(2) so any attempt to open the snapshot RW will fail return -EACCESS as expected. > It's with the LVM from the Conectiva kernel RPM, which > uses the source code from your 2.2 LVM driver. OK. I will fix the is_read_only thing for the snapshot but you should make sure the bug that is oopsing your machine gets fixed too :). Andrea