ocfs2/dlm: let sender retry if dlm_dispatch_assert_master failed with -ENOMEM

Do not BUG() if GFP_ATOMIC allocation fails in dlm_dispatch_assert_master.
Instead, return -ENOMEM to the sender and then retry.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Alex Chen <alex.chen@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 13 insertions, 5 deletions

diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
index 3365839d2971..79b5af5e6a7b 100644
--- a/fs/ocfs2/dlm/dlmrecovery.c
+++ b/fs/ocfs2/dlm/dlmrecovery.c
@@ -1656,14 +1656,18 @@ int dlm_do_master_requery(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
         req.namelen = res->lockname.len;
         memcpy(req.name, res->lockname.name, res->lockname.len);
 
+resend:
         ret = o2net_send_message(DLM_MASTER_REQUERY_MSG, dlm->key,
                                  &req, sizeof(req), nodenum, &status);
-        /* XXX: negative status not handled properly here. */
         if (ret < 0)
                 mlog(ML_ERROR, "Error %d when sending message %u (key "
                      "0x%x) to node %u\n", ret, DLM_MASTER_REQUERY_MSG,
                      dlm->key, nodenum);
-        else {
+        else if (status == -ENOMEM) {
+                mlog_errno(status);
+                msleep(50);
+                goto resend;
+        } else {
                 BUG_ON(status < 0);
                 BUG_ON(status > DLM_LOCK_RES_OWNER_UNKNOWN);
                 *real_master = (u8) (status & 0xff);
@@ -1705,9 +1709,13 @@ int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data,
                         int ret = dlm_dispatch_assert_master(dlm, res,
                                                              0, 0, flags);
                         if (ret < 0) {
-                                mlog_errno(-ENOMEM);
-                                /* retry!? */
-                                BUG();
+                                mlog_errno(ret);
+                                spin_unlock(&res->spinlock);
+                                dlm_lockres_put(res);
+                                spin_unlock(&dlm->spinlock);
+                                dlm_put(dlm);
+                                /* sender will take care of this and retry */
+                                return ret;
                         } else
                                 __dlm_lockres_grab_inflight_worker(dlm, res);
                         spin_unlock(&res->spinlock);