Introduce a new API to fs/lockd/mon.c that allows nlm_host_rebooted()
to lookup up nsm_handles via the contents of an nlm_reboot struct.
The new function is equivalent to calling nsm_find() with @create set
to zero, but it takes a struct nlm_reboot instead of separate
arguments.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
fs/lockd/mon.c | 64 +++++++++++++++++++++++++++++++++++++++++++
include/linux/lockd/lockd.h | 1 +
2 files changed, 65 insertions(+), 0 deletions(-)
diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
index e0a799d..65fb904 100644
--- a/fs/lockd/mon.c
+++ b/fs/lockd/mon.c
@@ -202,6 +202,29 @@ void nsm_unmonitor(const struct nlm_host *host)
}
}
+static struct nsm_handle *nsm_lookup_hostname(const char *hostname,
+ const size_t len)
+{
+ struct nsm_handle *nsm;
+
+ list_for_each_entry(nsm, &nsm_handles, sm_link)
+ if (strlen(nsm->sm_name) == len &&
+ memcmp(nsm->sm_name, hostname, len) == 0)
+ return nsm;
+ return NULL;
+}
+
+static struct nsm_handle *nsm_lookup_priv(const struct nsm_private *priv)
+{
+ struct nsm_handle *nsm;
+
+ list_for_each_entry(nsm, &nsm_handles, sm_link)
+ if (memcmp(nsm->sm_priv.data, priv->data,
+ sizeof(priv->data)) == 0)
+ return nsm;
+ return NULL;
+}
+
/*
* Construct a unique cookie to match this nsm_handle to this monitored
* host. It is passed to the local rpc.statd via NSMPROC_MON, and
@@ -298,6 +321,47 @@ retry:
}
/**
+ * nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle
+ * @info: pointer to NLMPROC_SM_NOTIFY arguments
+ *
+ * Returns a matching nsm_handle if found in the nsm cache; the returned
+ * nsm_handle's reference count is bumped and sm_monitored is cleared.
+ * Otherwise returns NULL if some error occurred.
+ */
+struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info)
+{
+ struct nsm_handle *cached;
+
+ spin_lock(&nsm_lock);
+
+ if (nsm_use_hostnames && info->mon != NULL)
+ cached = nsm_lookup_hostname(info->mon, info->len);
+ else
+ cached = nsm_lookup_priv(&info->priv);
+
+ if (unlikely(cached == NULL)) {
+ spin_unlock(&nsm_lock);
+ dprintk("lockd: never saw rebooted peer '%.*s' before\n",
+ info->len, info->mon);
+ return cached;
+ }
+
+ atomic_inc(&cached->sm_count);
+ spin_unlock(&nsm_lock);
+
+ /*
+ * During subsequent lock activity, force a fresh
+ * notification to be set up for this host.
+ */
+ cached->sm_monitored = 0;
+
+ dprintk("lockd: host %s (%s) rebooted, cnt %d\n",
+ cached->sm_name, cached->sm_addrbuf,
+ atomic_read(&cached->sm_count));
+ return cached;
+}
+
+/**
* nsm_release - Release an NSM handle
* @nsm: pointer to handle to be released
*
diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h
index 2a3533e..5e3ad92 100644
--- a/include/linux/lockd/lockd.h
+++ b/include/linux/lockd/lockd.h
@@ -251,6 +251,7 @@ struct nsm_handle *nsm_find(const struct sockaddr *sap, const size_t salen,
const char *hostname,
const size_t hostname_len,
const int create);
+struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info);
void nsm_release(struct nsm_handle *nsm);
/*
--
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