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LU-17504 build: fix gcc-13 [-Werror=stringop-overread] error
[fs/lustre-release.git] / lustre / lov / lov_page.c
index 869c0b8..db0c852 100644 (file)
  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2011, 2016, Intel Corporation.
+ * Copyright (c) 2011, 2017, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
- * Lustre is a trademark of Sun Microsystems, Inc.
  *
  * Implementation of cl_page for LOV layer.
  *
 #define DEBUG_SUBSYSTEM S_LOV
 
 #include "lov_cl_internal.h"
+#include <linux/bug.h>
+#include <linux/compiler.h>
 
 /** \addtogroup lov
  *  @{
  */
 
-/*****************************************************************************
- *
+/**
  * Lov page operations.
- *
  */
-
-static int lov_comp_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, comp index: %x\n",
-                         lp, lp->lps_index);
-}
-
-static const struct cl_page_operations lov_comp_page_ops = {
-       .cpo_print = lov_comp_page_print
-};
-
 int lov_page_init_composite(const struct lu_env *env, struct cl_object *obj,
                            struct cl_page *page, pgoff_t index)
 {
        struct lov_object *loo = cl2lov(obj);
-       struct lov_io     *lio = lov_env_io(env);
-       struct cl_object  *subobj;
-       struct cl_object  *o;
+       struct lov_io *lio = lov_env_io(env);
+       struct cl_object *subobj;
+       struct cl_object *o;
        struct lov_io_sub *sub;
-       struct lov_page   *lpg = cl_object_page_slice(obj, page);
        struct lov_layout_raid0 *r0;
-       loff_t             offset;
-       loff_t             suboff;
-       int                entry;
-       int                stripe;
-       int                rc;
+       loff_t offset;
+       loff_t suboff;
+       bool stripe_cached = false;
+       int entry;
+       int stripe;
+       int rc;
+
        ENTRY;
 
-       offset = cl_offset(obj, index);
-       entry = lov_lsm_entry(loo->lo_lsm, offset);
+       /* Direct i/o (CPT_TRANSIENT) is split strictly to stripes, so we can
+        * cache the stripe information.  Buffered i/o is differently
+        * organized, and stripe calculation isn't a significant cost for
+        * buffered i/o, so we only cache this for direct i/o.
+        */
+       stripe_cached = lio->lis_cached_entry != LIS_CACHE_ENTRY_NONE &&
+                       page->cp_type == CPT_TRANSIENT;
+
+       offset = index << PAGE_SHIFT;
+
+       if (stripe_cached) {
+               entry = lio->lis_cached_entry;
+               /* if there's no layout at this offset, we'll end up here with
+                * a cached layout entry, so we must verify the layout includes
+                * this offset
+                */
+               if (!lov_io_layout_at_confirm(lio, entry, offset))
+                       return -ENODATA;
+               stripe = lio->lis_cached_stripe;
+               /* Offset can never go backwards in an i/o, so this is valid */
+               suboff = lio->lis_cached_suboff + offset - lio->lis_cached_off;
+       } else {
+               entry = lov_io_layout_at(lio, offset);
+               if (entry < 0)
+                       return -ENODATA;
+
+               stripe = lov_stripe_number(loo->lo_lsm, entry, offset);
+               rc = lov_stripe_offset(loo->lo_lsm, entry, offset, stripe,
+                                      &suboff);
+               LASSERT(rc == 0);
+               lio->lis_cached_entry = entry;
+               lio->lis_cached_stripe = stripe;
+               lio->lis_cached_off = offset;
+               lio->lis_cached_suboff = suboff;
+       }
+
        if (entry < 0 || !lsm_entry_inited(loo->lo_lsm, entry)) {
                /* non-existing layout component */
                lov_page_init_empty(env, obj, page, index);
                RETURN(0);
        }
 
-       r0 = lov_r0(loo, entry);
-       stripe = lov_stripe_number(loo->lo_lsm, entry, offset);
-       LASSERT(stripe < r0->lo_nr);
-       rc = lov_stripe_offset(loo->lo_lsm, entry, offset, stripe, &suboff);
-       LASSERT(rc == 0);
+       CDEBUG(D_PAGE, "offset %llu, entry %d, stripe %d, suboff %llu\n",
+              offset, entry, stripe, suboff);
+
+       page->cp_lov_index = lov_comp_index(entry, stripe);
+       LASSERT(page->cp_lov_index != CP_LOV_INDEX_EMPTY);
 
-       lpg->lps_index = lov_comp_index(entry, stripe);
-       cl_page_slice_add(page, &lpg->lps_cl, obj, index, &lov_comp_page_ops);
+       if (!stripe_cached) {
+               sub = lov_sub_get(env, lio, page->cp_lov_index);
+               if (IS_ERR(sub))
+                       RETURN(PTR_ERR(sub));
+       } else {
+               sub = lio->lis_cached_sub;
+       }
 
-       sub = lov_sub_get(env, lio, lpg->lps_index);
-       if (IS_ERR(sub))
-               RETURN(PTR_ERR(sub));
+       lio->lis_cached_sub = sub;
+
+       r0 = lov_r0(loo, entry);
+       LASSERT(stripe < r0->lo_nr);
 
        subobj = lovsub2cl(r0->lo_sub[stripe]);
-       list_for_each_entry(o, &subobj->co_lu.lo_header->loh_layers,
-                           co_lu.lo_linkage) {
-               if (o->co_ops->coo_page_init != NULL) {
+       cl_object_for_each(o, subobj) {
+               if (o->co_ops->coo_page_init) {
                        rc = o->co_ops->coo_page_init(sub->sub_env, o, page,
-                                                     cl_index(subobj, suboff));
+                                                     suboff >> PAGE_SHIFT);
                        if (rc != 0)
                                break;
                }
@@ -116,34 +139,27 @@ int lov_page_init_composite(const struct lu_env *env, struct cl_object *obj,
        RETURN(rc);
 }
 
-static int lov_empty_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, empty.\n", lp);
-}
-
-static const struct cl_page_operations lov_empty_page_ops = {
-       .cpo_print = lov_empty_page_print
-};
-
 int lov_page_init_empty(const struct lu_env *env, struct cl_object *obj,
-                       struct cl_page *page, pgoff_t index)
+                       struct cl_page *cl_page, pgoff_t index)
 {
-       struct lov_page *lpg = cl_object_page_slice(obj, page);
        void *addr;
+
        ENTRY;
+       BUILD_BUG_ON(!__same_type(cl_page->cp_lov_index, CP_LOV_INDEX_EMPTY));
+       cl_page->cp_lov_index = CP_LOV_INDEX_EMPTY;
 
-       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);
-       cl_page_export(env, page, 1);
+       addr = kmap(cl_page->cp_vmpage);
+       memset(addr, 0, PAGE_SIZE);
+       kunmap(cl_page->cp_vmpage);
+       SetPageUptodate(cl_page->cp_vmpage);
        RETURN(0);
 }
 
+int lov_page_init_foreign(const struct lu_env *env, struct cl_object *obj,
+                       struct cl_page *page, pgoff_t index)
+{
+       CDEBUG(D_PAGE, DFID" has no data\n", PFID(lu_object_fid(&obj->co_lu)));
+       RETURN(-ENODATA);
+}
 
 /** @} lov */
-