LU-13798 llite: parallelize direct i/o issuance

[fs/lustre-release.git] / lustre / osc / osc_cache.c

diff --git a/lustre/osc/osc_cache.c b/lustre/osc/osc_cache.c
index 9d3d22b..a3953db 100644 (file)
--- a/lustre/osc/osc_cache.c
+++ b/lustre/osc/osc_cache.c
@@ -2559,7 +2559,7 @@ out:
        return rc;
 }
 
-int osc_queue_sync_pages(const struct lu_env *env, const struct cl_io *io,
+int osc_queue_sync_pages(const struct lu_env *env, struct cl_io *io,
                         struct osc_object *obj, struct list_head *list,
                         int brw_flags)
 {
@@ -2619,6 +2619,7 @@ int osc_queue_sync_pages(const struct lu_env *env, const struct cl_io *io,
                grants += (1 << cli->cl_chunkbits) *
                        ((page_count + ppc - 1) / ppc);
 
+               CDEBUG(D_CACHE, "requesting %d bytes grant\n", grants);
                spin_lock(&cli->cl_loi_list_lock);
                if (osc_reserve_grant(cli, grants) == 0) {
                        list_for_each_entry(oap, list, oap_pending_item) {
@@ -2628,6 +2629,15 @@ int osc_queue_sync_pages(const struct lu_env *env, const struct cl_io *io,
                        }
                        osc_unreserve_grant_nolock(cli, grants, 0);
                        ext->oe_grants = grants;
+               } else {
+                       /* We cannot report ENOSPC correctly if we do parallel
+                        * DIO (async RPC submission), so turn off parallel dio
+                        * if there is not sufficient grant available.  This
+                        * makes individual RPCs synchronous.
+                        */
+                       io->ci_parallel_dio = false;
+                       CDEBUG(D_CACHE,
+                       "not enough grant available, switching to sync for this i/o\n");
                }
                spin_unlock(&cli->cl_loi_list_lock);
        }