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[PATCH] NLM: Fix the NLM_GRANTED callback checks

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If 2 threads attached to the same process are blocking on different locks on
different files (maybe even on different servers) but have the same lock
arguments (i.e.  same offset+length - actually quite common, since most
processes try to lock the entire file) then the first GRANTED call that wakes
one up will also wake the other.

Currently when the NLM_GRANTED callback comes in, lockd walks the list of
blocked locks in search of a match to the lock that the NLM server has
granted.  Although it checks the lock pid, start and end, it fails to check
the filehandle and the server address.

By checking the filehandle and server IP address, we ensure that this only
happens if the locks truly are referencing the same file.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Trond Myklebust
2006-02-14 13:53:04 -08:00
committed by Linus Torvalds
parent 7c8903f637
commit 5ac5f9d1ce
4 changed files with 22 additions and 15 deletions
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2
fs/lockd/svc4proc.c
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@@ -228,7 +228,7 @@ nlm4svc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
resp->cookie = argp->cookie;
dprintk("lockd: GRANTED called\n");
resp->status = nlmclnt_grant(&argp->lock);
resp->status = nlmclnt_grant(&rqstp->rq_addr, &argp->lock);
dprintk("lockd: GRANTED status %d\n", ntohl(resp->status));
return rpc_success;
}