Merge tag 'ceph-for-5.18-rc5' of https://github.com/ceph/ceph-client

Pull ceph client fixes from Ilya Dryomov:
 "A fix for a NULL dereference that turns out to be easily triggerable
  by fsync (marked for stable) and a false positive WARN and snap_rwsem
  locking fixups"

* tag 'ceph-for-5.18-rc5' of https://github.com/ceph/ceph-client:
  ceph: fix possible NULL pointer dereference for req->r_session
  ceph: remove incorrect session state check
  ceph: get snap_rwsem read lock in handle_cap_export for ceph_add_cap
  libceph: disambiguate cluster/pool full log message

fs/ceph/caps.c

@@ -2274,6 +2274,8 @@ static int unsafe_request_wait(struct inode *inode)
 			list_for_each_entry(req, &ci->i_unsafe_dirops,
 					    r_unsafe_dir_item) {
 				s = req->r_session;
+				if (!s)
+					continue;
 				if (unlikely(s->s_mds >= max_sessions)) {
 					spin_unlock(&ci->i_unsafe_lock);
 					for (i = 0; i < max_sessions; i++) {
@@ -2294,6 +2296,8 @@ static int unsafe_request_wait(struct inode *inode)
 			list_for_each_entry(req, &ci->i_unsafe_iops,
 					    r_unsafe_target_item) {
 				s = req->r_session;
+				if (!s)
+					continue;
 				if (unlikely(s->s_mds >= max_sessions)) {
 					spin_unlock(&ci->i_unsafe_lock);
 					for (i = 0; i < max_sessions; i++) {
@@ -3870,6 +3874,7 @@ static void handle_cap_export(struct inode *inode, struct ceph_mds_caps *ex,
 	dout("handle_cap_export inode %p ci %p mds%d mseq %d target %d\n",
 	     inode, ci, mds, mseq, target);
 retry:
+	down_read(&mdsc->snap_rwsem);
 	spin_lock(&ci->i_ceph_lock);
 	cap = __get_cap_for_mds(ci, mds);
 	if (!cap || cap->cap_id != le64_to_cpu(ex->cap_id))
@@ -3933,6 +3938,7 @@ static void handle_cap_export(struct inode *inode, struct ceph_mds_caps *ex,
 	}
 
 	spin_unlock(&ci->i_ceph_lock);
+	up_read(&mdsc->snap_rwsem);
 	mutex_unlock(&session->s_mutex);
 
 	/* open target session */
@@ -3958,6 +3964,7 @@ static void handle_cap_export(struct inode *inode, struct ceph_mds_caps *ex,
 
 out_unlock:
 	spin_unlock(&ci->i_ceph_lock);
+	up_read(&mdsc->snap_rwsem);
 	mutex_unlock(&session->s_mutex);
 	if (tsession) {
 		mutex_unlock(&tsession->s_mutex);

fs/ceph/mds_client.c

@@ -4434,8 +4434,6 @@ static void maybe_recover_session(struct ceph_mds_client *mdsc)
 
 bool check_session_state(struct ceph_mds_session *s)
 {
-	struct ceph_fs_client *fsc = s->s_mdsc->fsc;
-
 	switch (s->s_state) {
 	case CEPH_MDS_SESSION_OPEN:
 		if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
@@ -4444,10 +4442,6 @@ bool check_session_state(struct ceph_mds_session *s)
 		}
 		break;
 	case CEPH_MDS_SESSION_CLOSING:
-		/* Should never reach this when not force unmounting */
-		WARN_ON_ONCE(s->s_ttl &&
-			     READ_ONCE(fsc->mount_state) != CEPH_MOUNT_SHUTDOWN);
-		fallthrough;
 	case CEPH_MDS_SESSION_NEW:
 	case CEPH_MDS_SESSION_RESTARTING:
 	case CEPH_MDS_SESSION_CLOSED:

net/ceph/osd_client.c

@@ -2385,7 +2385,11 @@ static void __submit_request(struct ceph_osd_request *req, bool wrlocked)
 		if (ceph_test_opt(osdc->client, ABORT_ON_FULL)) {
 			err = -ENOSPC;
 		} else {
-			pr_warn_ratelimited("FULL or reached pool quota\n");
+			if (ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL))
+				pr_warn_ratelimited("cluster is full (osdmap FULL)\n");
+			else
+				pr_warn_ratelimited("pool %lld is full or reached quota\n",
+						    req->r_t.base_oloc.pool);
 			req->r_t.paused = true;
 			maybe_request_map(osdc);
 		}