ceph: handle SESSION_FORCE_RO message

mark session as readonly and wake up all cap waiters.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

4 files changed, 27 insertions, 0 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index b93c631c6c87..d0618e8412fd 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2143,6 +2143,21 @@ again:
                         ret = 1;
                 }
         } else {
+                int session_readonly = false;
+                if ((need & CEPH_CAP_FILE_WR) && ci->i_auth_cap) {
+                        struct ceph_mds_session *s = ci->i_auth_cap->session;
+                        spin_lock(&s->s_cap_lock);
+                        session_readonly = s->s_readonly;
+                        spin_unlock(&s->s_cap_lock);
+                }
+                if (session_readonly) {
+                        dout("get_cap_refs %p needed %s but mds%d readonly\n",
+                             inode, ceph_cap_string(need), ci->i_auth_cap->mds);
+                        *err = -EROFS;
+                        ret = 1;
+                        goto out_unlock;
+                }
+
                 dout("get_cap_refs %p have %s needed %s\n", inode,
                      ceph_cap_string(have), ceph_cap_string(need));
         }
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index d2171f4a6980..c6c33b411a2f 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2580,6 +2580,14 @@ static void handle_session(struct ceph_mds_session *session,
                 send_flushmsg_ack(mdsc, session, seq);
                 break;
 
+        case CEPH_SESSION_FORCE_RO:
+                dout("force_session_readonly %p\n", session);
+                spin_lock(&session->s_cap_lock);
+                session->s_readonly = true;
+                spin_unlock(&session->s_cap_lock);
+                wake_up_session_caps(session, 0);
+                break;
+
         default:
                 pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
                 WARN_ON(1);
@@ -2791,6 +2799,8 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc,
         spin_unlock(&session->s_gen_ttl_lock);
 
         spin_lock(&session->s_cap_lock);
+        /* don't know if session is readonly */
+        session->s_readonly = 0;
         /*
          * notify __ceph_remove_cap() that we are composing cap reconnect.
          * If a cap get released before being added to the cap reconnect,
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index e2817d00f7d9..a87b92f500bb 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -137,6 +137,7 @@ struct ceph_mds_session {
         int               s_nr_caps, s_trim_caps;
         int               s_num_cap_releases;
         int               s_cap_reconnect;
+        int               s_readonly;
         struct list_head  s_cap_releases; /* waiting cap_release messages */
         struct list_head  s_cap_releases_done; /* ready to send */
         struct ceph_cap  *s_cap_iterator;
diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h
index 69e2c9e2305b..31eb03d0c766 100644
--- a/include/linux/ceph/ceph_fs.h
+++ b/include/linux/ceph/ceph_fs.h
@@ -271,6 +271,7 @@ enum {
         CEPH_SESSION_RECALL_STATE,
         CEPH_SESSION_FLUSHMSG,
         CEPH_SESSION_FLUSHMSG_ACK,
+        CEPH_SESSION_FORCE_RO,
 };
 
 extern const char *ceph_session_op_name(int op);