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| author | Mike Marciniszyn <mike.marciniszyn@intel.com> | 2014-09-19 08:32:19 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-10-05 14:52:22 -0700 |
| commit | dcbcb3f64878ce4e43ba3500ba13e87e2c35397a (patch) | |
| tree | 25c9742c9dc2e56b4660ed767cc87455d79046bb | |
| parent | 192ffa5bb712446637fbf738b726a4fb873a7aac (diff) | |
| download | linux-stable-dcbcb3f64878ce4e43ba3500ba13e87e2c35397a.tar.gz linux-stable-dcbcb3f64878ce4e43ba3500ba13e87e2c35397a.tar.bz2 linux-stable-dcbcb3f64878ce4e43ba3500ba13e87e2c35397a.zip | |
IB/qib: Correct reference counting in debugfs qp_stats
commit 85cbb7c728bf39c45a9789b88c9471c0d7a58b0e upstream.
This particular reference count is not needed with the rcu protection,
and the current code leaks a reference count, causing a hang in
qib_qp_destroy().
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/infiniband/hw/qib/qib_debugfs.c | 3 | ||||
| -rw-r--r-- | drivers/infiniband/hw/qib/qib_qp.c | 8 |
2 files changed, 2 insertions, 9 deletions
diff --git a/drivers/infiniband/hw/qib/qib_debugfs.c b/drivers/infiniband/hw/qib/qib_debugfs.c index 799a0c3bffc4..6abd3ed3cd51 100644 --- a/drivers/infiniband/hw/qib/qib_debugfs.c +++ b/drivers/infiniband/hw/qib/qib_debugfs.c @@ -193,6 +193,7 @@ static void *_qp_stats_seq_start(struct seq_file *s, loff_t *pos) struct qib_qp_iter *iter; loff_t n = *pos; + rcu_read_lock(); iter = qib_qp_iter_init(s->private); if (!iter) return NULL; @@ -224,7 +225,7 @@ static void *_qp_stats_seq_next(struct seq_file *s, void *iter_ptr, static void _qp_stats_seq_stop(struct seq_file *s, void *iter_ptr) { - /* nothing for now */ + rcu_read_unlock(); } static int _qp_stats_seq_show(struct seq_file *s, void *iter_ptr) diff --git a/drivers/infiniband/hw/qib/qib_qp.c b/drivers/infiniband/hw/qib/qib_qp.c index 0cad0c40d742..6a71b2b41b27 100644 --- a/drivers/infiniband/hw/qib/qib_qp.c +++ b/drivers/infiniband/hw/qib/qib_qp.c @@ -1324,7 +1324,6 @@ int qib_qp_iter_next(struct qib_qp_iter *iter) struct qib_qp *pqp = iter->qp; struct qib_qp *qp; - rcu_read_lock(); for (; n < dev->qp_table_size; n++) { if (pqp) qp = rcu_dereference(pqp->next); @@ -1332,18 +1331,11 @@ int qib_qp_iter_next(struct qib_qp_iter *iter) qp = rcu_dereference(dev->qp_table[n]); pqp = qp; if (qp) { - if (iter->qp) - atomic_dec(&iter->qp->refcount); - atomic_inc(&qp->refcount); - rcu_read_unlock(); iter->qp = qp; iter->n = n; return 0; } } - rcu_read_unlock(); - if (iter->qp) - atomic_dec(&iter->qp->refcount); return ret; } |