On Wed, Feb 04, 2009 at 06:33:48PM -0500, J. Bruce Fields wrote: > On Tue, Dec 16, 2008 at 03:16:10PM -0500, bfields wrote: > > On Tue, Dec 16, 2008 at 08:43:52PM +0100, Miklos Szeredi wrote: > > > On Tue, 2008-12-16 at 12:39 -0500, J. Bruce Fields wrote: > > > > More precisely, it looks like this started with > > > > > > > > bde74e4bc64415b142e "locks: add special return value for > > > > asynchronous locks" > > > > > > > > But I haven't had the chance to look any harder yet. Miklos? Is this > > > > easy for you to reproduce? > > > > > > Not immediately, at the moment I don't have NFS set up. But if you > > > don't beat me to it, I'll look into this. > > > > OK, thanks. I'll take another look too when I get the chance, so let me > > know of any partial result. > > > > It may just for example be returning the wrong error to the client on an > > nlm blocking lock request, so that the client assumes the lock is gone > > and goes away rather than waiting for a grant request. > > Sorry, I've gotten a bit backlogged, but I finally got back to this. If > there's no objections, the following is what I intend to submit. > > --b. > > commit cb8b864ea6addd3a3e72fe835aafecec63f06cbd > Author: J. Bruce Fields <bfields@xxxxxxxxxxxxxxxx> > Date: Wed Feb 4 17:35:38 2009 -0500 > > lockd: fix regression in lockd's handling of blocked locks > > If a client requests a blocking lock, is denied, then requests it again, > then here in nlmsvc_lock() we will call vfs_lock_file() without FL_SLEEP > set, because we've already queued a block and don't need the locks code > to do it again. > > But that means vfs_lock_file() will return -EAGAIN instead of > FILE_LOCK_DENIED. So we still need to translate that -EAGAIN return > into a nlm_lck_blocked error in this case, and put ourselves back on > lockd's block list. > > The bug was introduced by bde74e4bc64415b1 "locks: add special return > value for asynchronous locks". > > Thanks to From: Frank van Maarseveen for the report; his original test > case was essentially > > for i in `seq 30`; do flock /nfsmount/foo sleep 10 & done > > Cc: Frank van Maarseveen <frankvm@xxxxxxxxxxx> > Cc: Miklos Szeredi <mszeredi@xxxxxxx> > Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxxxxxx> > > diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c > index 6063a8e..763b78a 100644 > --- a/fs/lockd/svclock.c > +++ b/fs/lockd/svclock.c > @@ -427,7 +427,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, > goto out; > case -EAGAIN: > ret = nlm_lck_denied; > - goto out; > + break; > case FILE_LOCK_DEFERRED: > if (wait) > break; > @@ -443,6 +443,10 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, > goto out; > } > > + ret = nlm_lck_denied; > + if (!wait) > + goto out; > + > ret = nlm_lck_blocked; > > /* Append to list of blocked */ fix confirmed, thanks! -- Frank -- 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
