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 a8a574897d3c3ec0b8f685a430f0cbacf8c5872b..fe757514feb17ea090f61c14a1b801752bcfdcbe 100644 (file)
--- a/include/linux/ceph/libceph.h
+++ b/include/linux/ceph/libceph.h
@@ -276,6 +276,8 @@ 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 464e88599b9d2918f191eae62e1fab7b80a4806e..bf0294cf4d22f9ee38f2810d0a0bdb7196a34a41 100644 (file)
--- a/net/ceph/ceph_common.c
+++ b/net/ceph/ceph_common.c
@@ -699,7 +699,6 @@ 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;
@@ -715,6 +714,23 @@ 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 500481003de455aa36be564f975f35aba2dfee2c..288c1fcbcdf6ccb421972f3a24985d53d7e4a961 100644 (file)
--- a/net/ceph/mon_client.c
+++ b/net/ceph/mon_client.c
@@ -914,6 +914,15 @@ 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;