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>

diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
index 3365839d29716f101759c6dc86355393ee7c3ab4..79b5af5e6a7b5d8a593a251cfa8c27aa11769447 100644 (file)
--- 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);