*/
/*
* 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, gen: %u\n",
- lp, lp->lps_layout_gen);
-}
-
-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 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;
+ bool stripe_cached = false;
int entry;
int stripe;
int rc;
ENTRY;
+ /* 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 = cl_offset(obj, index);
- entry = lov_io_layout_at(lio, offset);
+
+ if (stripe_cached) {
+ entry = lio->lis_cached_entry;
+ 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);
- lpg->lps_layout_gen = loo->lo_lsm->lsm_layout_gen;
- cl_page_slice_add(page, &lpg->lps_cl, obj, index, &lov_comp_page_ops);
+ LASSERT(page->cp_lov_index != CP_LOV_INDEX_EMPTY);
+
+ 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, page->cp_lov_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) {
+ 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));
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 lov_page *lpg = cl_object_page_slice(obj, page);
void *addr;
ENTRY;
+ BUILD_BUG_ON(!__same_type(page->cp_lov_index, CP_LOV_INDEX_EMPTY));
+ page->cp_lov_index = CP_LOV_INDEX_EMPTY;
- page->cp_lov_index = ~0;
- 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);
+ SetPageUptodate(page->cp_vmpage);
RETURN(0);
}
RETURN(-ENODATA);
}
-bool lov_page_is_empty(const struct cl_page *page)
-{
- const struct cl_page_slice *slice = cl_page_at(page, &lov_device_type);
-
- LASSERT(slice != NULL);
- return slice->cpl_ops == &lov_empty_page_ops;
-}
-
-
/** @} lov */
-
git://git.whamcloud.com / fs / lustre-release.git / blobdiff