Commit:     0272e1fd9f4fa8a43357c168e081744f99e67195
Parent:     354ecbb9dd89c21708b319da8c4ffd3dd6e6811d
Author:     J. Bruce Fields <[EMAIL PROTECTED]>
AuthorDate: Wed Sep 12 18:56:12 2007 -0400
Committer:  J. Bruce Fields <[EMAIL PROTECTED]>
CommitDate: Tue Oct 9 18:31:57 2007 -0400

    knfsd: let nfsd manage timing out its own leases
    Currently there's a race that can cause an oops in generic_setlease.
    (In detail: nfsd, when it removes a lease, does so by calling
    vfs_setlease() with F_UNLCK and a pointer to the fl_flock field, which
    in turn points to nfsd's existing lease; but the first thing the
    setlease code does is call time_out_leases().  If the lease happens to
    already be beyond the lease break time, that will free the lease and (in
    nfsd's release_private callback) set fl_flock to NULL, leading to a NULL
    deference soon after in vfs_setlease().)
    There are probably other things to fix here too, but it seems inherently
    racy to allow either locks.c or nfsd to time out this lease.  Instead
    just set the fl_break_time to 0 (preventing locks.c from ever timing out
    this lock) and leave it up to nfsd's laundromat thread to deal with it.
    Signed-off-by: J. Bruce Fields <[EMAIL PROTECTED]>
 fs/nfsd/nfs4state.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 6256492..48fbdac 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1354,8 +1354,12 @@ void nfsd_break_deleg_cb(struct file_lock *fl)
        /* only place dl_time is set. protected by lock_kernel*/
        dp->dl_time = get_seconds();
-       /* XXX need to merge NFSD_LEASE_TIME with fs/locks.c:lease_break_time */
-       fl->fl_break_time = jiffies + NFSD_LEASE_TIME * HZ;
+       /*
+        * We don't want the locks code to timeout the lease for us;
+        * we'll remove it ourself if the delegation isn't returned
+        * in time.
+        */
+       fl->fl_break_time = 0;
        t = kthread_run(do_recall, dp, "%s", "nfs4_cb_recall");
        if (IS_ERR(t)) {
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