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| author | NeilBrown <[email protected]> | 2019-03-19 00:33:24 +0000 |
|---|---|---|
| committer | Trond Myklebust <[email protected]> | 2019-03-19 02:39:34 +0000 |
| commit | 4a9be28c45bf02fa0436808bb6c0baeba30e120e (patch) | |
| tree | 281d3195bf4c2743e76911099151d874930b8621 /tools/perf/scripts/python | |
| parent | NFS: Fix nfs4_lock_state refcounting in nfs4_alloc_{lock,unlock}data() (diff) | |
| download | kernel-4a9be28c45bf02fa0436808bb6c0baeba30e120e.tar.gz kernel-4a9be28c45bf02fa0436808bb6c0baeba30e120e.zip | |
NFS: fix mount/umount race in nlmclnt.
If the last NFSv3 unmount from a given host races with a mount from the
same host, we can destroy an nlm_host that is still in use.
Specifically nlmclnt_lookup_host() can increment h_count on
an nlm_host that nlmclnt_release_host() has just successfully called
refcount_dec_and_test() on.
Once nlmclnt_lookup_host() drops the mutex, nlm_destroy_host_lock()
will be called to destroy the nlmclnt which is now in use again.
The cause of the problem is that the dec_and_test happens outside the
locked region. This is easily fixed by using
refcount_dec_and_mutex_lock().
Fixes: 8ea6ecc8b075 ("lockd: Create client-side nlm_host cache")
Cc: [email protected] (v2.6.38+)
Signed-off-by: NeilBrown <[email protected]>
Signed-off-by: Trond Myklebust <[email protected]>
Diffstat (limited to 'tools/perf/scripts/python')
0 files changed, 0 insertions, 0 deletions