LU-3321 clio: optimize read ahead code

[fs/lustre-release.git] / lustre / lov / lov_page.c

diff --git a/lustre/lov/lov_page.c b/lustre/lov/lov_page.c
index e5b3221..75ded96 100644 (file)
--- a/lustre/lov/lov_page.c
+++ b/lustre/lov/lov_page.c
@@ -53,17 +53,57 @@
  *
  */
 
-static int lov_page_print(const struct lu_env *env,
-                          const struct cl_page_slice *slice,
-                          void *cookie, lu_printer_t printer)
+/**
+ * Adjust the stripe index by layout of raid0. @max_index is the maximum
+ * page index covered by an underlying DLM lock.
+ * This function converts max_index from stripe level to file level, and make
+ * sure it's not beyond one stripe.
+ */
+static int lov_raid0_page_is_under_lock(const struct lu_env *env,
+                                       const struct cl_page_slice *slice,
+                                       struct cl_io *unused,
+                                       pgoff_t *max_index)
 {
-        struct lov_page *lp = cl2lov_page(slice);
+       struct lov_object *loo = cl2lov(slice->cpl_obj);
+       struct lov_layout_raid0 *r0 = lov_r0(loo);
+       pgoff_t index = *max_index;
+       unsigned int pps; /* pages per stripe */
+       ENTRY;
+
+       CDEBUG(D_READA, "*max_index = %lu, nr = %d\n", index, r0->lo_nr);
+       if (index == 0) /* the page is not covered by any lock */
+               RETURN(0);
+
+       if (r0->lo_nr == 1) /* single stripe file */
+               RETURN(0);
+
+       /* max_index is stripe level, convert it into file level */
+       if (index != CL_PAGE_EOF) {
+               int stripeno = lov_page_stripe(slice->cpl_page);
+               *max_index = lov_stripe_pgoff(loo->lo_lsm, index, stripeno);
+       }
+
+       /* calculate the end of current stripe */
+       pps = loo->lo_lsm->lsm_stripe_size >> PAGE_CACHE_SHIFT;
+       index = ((slice->cpl_index + pps) & ~(pps - 1)) - 1;
+
+       /* never exceed the end of the stripe */
+       *max_index = min_t(pgoff_t, *max_index, index);
+       RETURN(0);
+}
+
+static int lov_raid0_page_print(const struct lu_env *env,
+                               const struct cl_page_slice *slice,
+                               void *cookie, lu_printer_t printer)
+{
+       struct lov_page *lp = cl2lov_page(slice);
 
-        return (*printer)(env, cookie, LUSTRE_LOV_NAME"-page@%p\n", lp);
+       return (*printer)(env, cookie, LUSTRE_LOV_NAME"-page@%p, raid0\n", lp);
 }
 
-static const struct cl_page_operations lov_page_ops = {
-       .cpo_print = lov_page_print
+static const struct cl_page_operations lov_raid0_page_ops = {
+       .cpo_is_under_lock = lov_raid0_page_is_under_lock,
+       .cpo_print = lov_raid0_page_print
 };
 
 int lov_page_init_raid0(const struct lu_env *env, struct cl_object *obj,
@@ -89,7 +129,7 @@ int lov_page_init_raid0(const struct lu_env *env, struct cl_object *obj,
                               &suboff);
        LASSERT(rc == 0);
 
-       cl_page_slice_add(page, &lpg->lps_cl, obj, &lov_page_ops);
+       cl_page_slice_add(page, &lpg->lps_cl, obj, index, &lov_raid0_page_ops);
 
        sub = lov_sub_get(env, lio, stripe);
        if (IS_ERR(sub))
@@ -109,7 +149,7 @@ int lov_page_init_raid0(const struct lu_env *env, struct cl_object *obj,
        RETURN(rc);
 }
 
-static int lov_page_empty_print(const struct lu_env *env,
+static int lov_empty_page_print(const struct lu_env *env,
                                const struct cl_page_slice *slice,
                                void *cookie, lu_printer_t printer)
 {
@@ -119,7 +159,7 @@ static int lov_page_empty_print(const struct lu_env *env,
 }
 
 static const struct cl_page_operations lov_empty_page_ops = {
-       .cpo_print = lov_page_empty_print
+       .cpo_print = lov_empty_page_print
 };
 
 int lov_page_init_empty(const struct lu_env *env, struct cl_object *obj,
@@ -129,7 +169,7 @@ int lov_page_init_empty(const struct lu_env *env, struct cl_object *obj,
        void *addr;
        ENTRY;
 
-       cl_page_slice_add(page, &lpg->lps_cl, obj, &lov_empty_page_ops);
+       cl_page_slice_add(page, &lpg->lps_cl, obj, index, &lov_empty_page_ops);
        addr = kmap(page->cp_vmpage);
        memset(addr, 0, cl_page_size(obj));
        kunmap(page->cp_vmpage);