On Wed, Jun 1, 2016 at 4:41 PM, Trond Myklebust <trondmy@xxxxxxxxxxxxxxx> wrote: > You are misreading what I wrote. Your test should indeed give rise to an > OPEN_DOWNGRADE (unless there is a delegation involved). The code that was > misbehaving and that was fixed by the patch was triggering an OPEN_DOWNGRADE > from a stateid that had only been opened for RW. I see. With this patch, the upstream code no longer sends an OPEN_DOWNGRADE. I will investigate why then as it seems like a bug. > > > On 6/1/16, 16:31, "linux-nfs-owner@xxxxxxxxxxxxxxx on behalf of Olga > Kornievskaia" <linux-nfs-owner@xxxxxxxxxxxxxxx on behalf of aglo@xxxxxxxxx> > wrote: > >>I'm failing to think of what can trigger an open_downgrade? >>I thought the following example should trigger an open downgrade: >> >>fd0 = open(foo, RDRW) -- should be open on the wire for "both" >>fd1 = open(foo, RDONLY) -- should be open on the wire for "read" >>close(fd0) -- should trigger an open_downgrade >>read(fd1) >>close(fd1) >> >>However this commit says that it's not allowed by the spec. >> >>commit cd9288ffaea4359d5cfe2b8d264911506aed26a4 >>Author: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> >>Date: Thu Sep 18 11:51:32 2014 -0400 >> >> NFSv4: Fix another bug in the close/open_downgrade code >> >> James Drew reports another bug whereby the NFS client is now sending >> an OPEN_DOWNGRADE in a situation where it should really have sent a >> CLOSE: the client is opening the file for O_RDWR, but then trying to >> do a downgrade to O_RDONLY, which is not allowed by the NFSv4 spec. >> >> Reported-by: James Drews <drews@xxxxxxxxxxxxx> >> Link: http://lkml.kernel.org/r/541AD7E5.8020409@xxxxxxxxxxxxx >> Fixes: aee7af356e15 (NFSv4: Fix problems with close in the presence...) >> Cc: stable@xxxxxxxxxxxxxxx # 2.6.33+ >> Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> >> >>If RDWR to RDONLY isn't allowed then why do we have OPEN_DOWNGRADE at all? >>-- >>To unsubscribe from this list: send the line "unsubscribe linux-nfs" in >>the body of a message to majordomo@xxxxxxxxxxxxxxx >>More majordomo info at http://vger.kernel.org/majordomo-info.html >> > > > Disclaimer > > The information contained in this communication from the sender is > confidential. It is intended solely for use by the recipient and others > authorized to receive it. If you are not the recipient, you are hereby > notified that any disclosure, copying, distribution or taking action in > relation of the contents of this information is strictly prohibited and may > be unlawful. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
