LU-5092 nodemap: handle config changes while mid-flight

[fs/lustre-release.git] / lustre / mgc / mgc_request.c

diff --git a/lustre/mgc/mgc_request.c b/lustre/mgc/mgc_request.c
index 6415307..7b4db0c 100644 (file)
--- a/lustre/mgc/mgc_request.c
+++ b/lustre/mgc/mgc_request.c
@@ -1577,19 +1577,8 @@ static int mgc_process_recover_nodemap_log(struct obd_device *obd,
        struct config_llog_instance *cfg = &cld->cld_cfg;
        struct mgs_config_body *body;
        struct mgs_config_res *res;
-
-       /* When a nodemap config is received, we build a new nodemap config,
-        * with new nodemap structs. We keep track of the most recently added
-        * nodemap since the config is read ordered by nodemap_id, and so it
-        * is likely that the next record will be related. Because access to
-        * the nodemaps is single threaded until the nodemap_config is active,
-        * we don't need to reference count with recent_nodemap, though
-        * recent_nodemap should be set to NULL when the nodemap_config
-        * is either destroyed or set active.
-        */
        struct nodemap_config *new_config = NULL;
        struct lu_nodemap *recent_nodemap = NULL;
-
        struct ptlrpc_bulk_desc *desc;
        struct page **pages;
        __u64 config_read_offset = 0;
@@ -1622,8 +1611,9 @@ static int mgc_process_recover_nodemap_log(struct obd_device *obd,
                         GOTO(out, rc = -ENOMEM);
         }
 
+again:
 #ifdef HAVE_SERVER_SUPPORT
-       if (cld_is_nodemap(cld)) {
+       if (cld_is_nodemap(cld) && config_read_offset == 0) {
                new_config = nodemap_config_alloc();
                if (IS_ERR(new_config)) {
                        rc = PTR_ERR(new_config);
@@ -1632,7 +1622,6 @@ static int mgc_process_recover_nodemap_log(struct obd_device *obd,
                }
        }
 #endif
-again:
        LASSERT(cld_is_recover(cld) || cld_is_nodemap(cld));
        LASSERT(mutex_is_locked(&cld->cld_lock));
        req = ptlrpc_request_alloc(class_exp2cliimp(cld->cld_mgcexp),
@@ -1705,6 +1694,20 @@ again:
                GOTO(out, rc = -EINVAL);
 
        if (ealen == 0) { /* no logs transferred */
+#ifdef HAVE_SERVER_SUPPORT
+               /* config changed since first read RPC */
+               if (cld_is_nodemap(cld) && config_read_offset == 0) {
+                       recent_nodemap = NULL;
+                       nodemap_config_dealloc(new_config);
+                       new_config = NULL;
+
+                       CDEBUG(D_INFO, "nodemap config changed in transit, retrying\n");
+
+                       /* setting eof to false, we request config again */
+                       eof = false;
+                       GOTO(out, rc = 0);
+               }
+#endif
                if (!eof)
                        rc = -EINVAL;
                GOTO(out, rc);
@@ -1718,6 +1721,15 @@ again:
                mne_swab = !mne_swab;
 #endif
 
+       /* When a nodemap config is received, we build a new nodemap config,
+        * with new nodemap structs. We keep track of the most recently added
+        * nodemap since the config is read ordered by nodemap_id, and so it
+        * is likely that the next record will be related. Because access to
+        * the nodemaps is single threaded until the nodemap_config is active,
+        * we don't need to reference count with recent_nodemap, though
+        * recent_nodemap should be set to NULL when the nodemap_config
+        * is either destroyed or set active.
+        */
        for (i = 0; i < nrpages && ealen > 0; i++) {
                int rc2;
                union lu_page   *ptr;
@@ -1746,15 +1758,17 @@ again:
        }
 
 out:
-       if (req)
+       if (req) {
                ptlrpc_req_finished(req);
+               req = NULL;
+       }
 
        if (rc == 0 && !eof)
                goto again;
 
 #ifdef HAVE_SERVER_SUPPORT
        if (new_config != NULL) {
-               recent_nodemap = NULL;
+               /* recent_nodemap cannot be used after set_active/dealloc */
                if (rc == 0)
                        nodemap_config_set_active(new_config);
                else