libceph: wait for latest osdmap in ceph_monc_blacklist_add()

commit bb229bbb3bf63d23128e851a1f3b85c083178fa1 upstream.

Because map updates are distributed lazily, an OSD may not know about
the new blacklist for quite some time after "osd blacklist add" command
is completed.  This makes it possible for a blacklisted but still alive
client to overwrite a post-blacklist update, resulting in data
corruption.

Waiting for latest osdmap in ceph_monc_blacklist_add() and thus using
the post-blacklist epoch for all post-blacklist requests ensures that
all such requests "wait" for the blacklist to come into force on their
respective OSDs.

Cc: stable@vger.kernel.org
Fixes: 6305a3b41515 ("libceph: support for blacklisting clients")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jason Dillaman <dillaman@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/linux/ceph/libceph.h b/include/linux/ceph/libceph.h
index d3b04f9589a9a6fe9142575d123b60f5ae754010..c311cd13ea7de5ecb4b11eee232d9628b0af75b9 100644 (file)
--- a/include/linux/ceph/libceph.h
+++ b/include/linux/ceph/libceph.h
@@ -291,6 +291,8 @@ extern void ceph_destroy_client(struct ceph_client *client);
 extern int __ceph_open_session(struct ceph_client *client,
                               unsigned long started);
 extern int ceph_open_session(struct ceph_client *client);
+int ceph_wait_for_latest_osdmap(struct ceph_client *client,
+                               unsigned long timeout);
 
 /* pagevec.c */
 extern void ceph_release_page_vector(struct page **pages, int num_pages);

diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c
index cdb5b693a135e77c60007ddd1d5eaaa6ab8ec7a7..1001377ae4289b0363f7d261af57d2c355d63117 100644 (file)
--- a/net/ceph/ceph_common.c
+++ b/net/ceph/ceph_common.c
@@ -720,7 +720,6 @@ int __ceph_open_session(struct ceph_client *client, unsigned long started)
 }
 EXPORT_SYMBOL(__ceph_open_session);
 
-
 int ceph_open_session(struct ceph_client *client)
 {
        int ret;
@@ -736,6 +735,23 @@ int ceph_open_session(struct ceph_client *client)
 }
 EXPORT_SYMBOL(ceph_open_session);
 
+int ceph_wait_for_latest_osdmap(struct ceph_client *client,
+                               unsigned long timeout)
+{
+       u64 newest_epoch;
+       int ret;
+
+       ret = ceph_monc_get_version(&client->monc, "osdmap", &newest_epoch);
+       if (ret)
+               return ret;
+
+       if (client->osdc.osdmap->epoch >= newest_epoch)
+               return 0;
+
+       ceph_osdc_maybe_request_map(&client->osdc);
+       return ceph_monc_wait_osdmap(&client->monc, newest_epoch, timeout);
+}
+EXPORT_SYMBOL(ceph_wait_for_latest_osdmap);
 
 static int __init init_ceph_lib(void)
 {

diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c
index f14498a7eaec5de2764e0901aa26d232be143bb0..daca0af59942ed149f841d537c2ac62029559e81 100644 (file)
--- a/net/ceph/mon_client.c
+++ b/net/ceph/mon_client.c
@@ -922,6 +922,15 @@ int ceph_monc_blacklist_add(struct ceph_mon_client *monc,
        mutex_unlock(&monc->mutex);
 
        ret = wait_generic_request(req);
+       if (!ret)
+               /*
+                * Make sure we have the osdmap that includes the blacklist
+                * entry.  This is needed to ensure that the OSDs pick up the
+                * new blacklist before processing any future requests from
+                * this client.
+                */
+               ret = ceph_wait_for_latest_osdmap(monc->client, 0);
+
 out:
        put_generic_request(req);
        return ret;