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33 * This file is part of Lustre, http://www.lustre.org/
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36 * Implementation of cl_page for LOV layer.
38 * Author: Nikita Danilov <nikita.danilov@sun.com>
39 * Author: Jinshan Xiong <jinshan.xiong@intel.com>
42 #define DEBUG_SUBSYSTEM S_LOV
44 #include "lov_cl_internal.h"
50 /*****************************************************************************
52 * Lov page operations.
57 * Adjust the stripe index by layout of raid0. @max_index is the maximum
58 * page index covered by an underlying DLM lock.
59 * This function converts max_index from stripe level to file level, and make
60 * sure it's not beyond one stripe.
62 static int lov_raid0_page_is_under_lock(const struct lu_env *env,
63 const struct cl_page_slice *slice,
67 struct lov_object *loo = cl2lov(slice->cpl_obj);
68 struct lov_layout_raid0 *r0 = lov_r0(loo);
69 pgoff_t index = *max_index;
70 unsigned int pps; /* pages per stripe */
73 CDEBUG(D_READA, DFID "*max_index = %lu, nr = %d\n",
74 PFID(lu_object_fid(lov2lu(loo))), index, r0->lo_nr);
76 if (index == 0) /* the page is not covered by any lock */
79 if (r0->lo_nr == 1) /* single stripe file */
82 /* max_index is stripe level, convert it into file level */
83 if (index != CL_PAGE_EOF) {
84 int stripeno = lov_page_stripe(slice->cpl_page);
85 *max_index = lov_stripe_pgoff(loo->lo_lsm, index, stripeno);
88 /* calculate the end of current stripe */
89 pps = loo->lo_lsm->lsm_stripe_size >> PAGE_CACHE_SHIFT;
90 index = slice->cpl_index + pps - slice->cpl_index % pps - 1;
92 CDEBUG(D_READA, DFID "*max_index = %lu, index = %lu, pps = %u, "
93 "stripe_size = %u, stripe no = %u, page index = %lu\n",
94 PFID(lu_object_fid(lov2lu(loo))), *max_index, index, pps,
95 loo->lo_lsm->lsm_stripe_size, lov_page_stripe(slice->cpl_page),
98 /* never exceed the end of the stripe */
99 *max_index = min_t(pgoff_t, *max_index, index);
103 static int lov_raid0_page_print(const struct lu_env *env,
104 const struct cl_page_slice *slice,
105 void *cookie, lu_printer_t printer)
107 struct lov_page *lp = cl2lov_page(slice);
109 return (*printer)(env, cookie, LUSTRE_LOV_NAME"-page@%p, raid0\n", lp);
112 static const struct cl_page_operations lov_raid0_page_ops = {
113 .cpo_is_under_lock = lov_raid0_page_is_under_lock,
114 .cpo_print = lov_raid0_page_print
117 int lov_page_init_raid0(const struct lu_env *env, struct cl_object *obj,
118 struct cl_page *page, pgoff_t index)
120 struct lov_object *loo = cl2lov(obj);
121 struct lov_layout_raid0 *r0 = lov_r0(loo);
122 struct lov_io *lio = lov_env_io(env);
123 struct cl_object *subobj;
125 struct lov_io_sub *sub;
126 struct lov_page *lpg = cl_object_page_slice(obj, page);
133 offset = cl_offset(obj, index);
134 stripe = lov_stripe_number(loo->lo_lsm, offset);
135 LASSERT(stripe < r0->lo_nr);
136 rc = lov_stripe_offset(loo->lo_lsm, offset, stripe,
140 lpg->lps_stripe = stripe;
141 cl_page_slice_add(page, &lpg->lps_cl, obj, index, &lov_raid0_page_ops);
143 sub = lov_sub_get(env, lio, stripe);
145 RETURN(PTR_ERR(sub));
147 subobj = lovsub2cl(r0->lo_sub[stripe]);
148 list_for_each_entry(o, &subobj->co_lu.lo_header->loh_layers,
150 if (o->co_ops->coo_page_init != NULL) {
151 rc = o->co_ops->coo_page_init(sub->sub_env, o, page,
152 cl_index(subobj, suboff));
161 static int lov_empty_page_print(const struct lu_env *env,
162 const struct cl_page_slice *slice,
163 void *cookie, lu_printer_t printer)
165 struct lov_page *lp = cl2lov_page(slice);
167 return (*printer)(env, cookie, LUSTRE_LOV_NAME"-page@%p, empty.\n", lp);
170 static const struct cl_page_operations lov_empty_page_ops = {
171 .cpo_print = lov_empty_page_print
174 int lov_page_init_empty(const struct lu_env *env, struct cl_object *obj,
175 struct cl_page *page, pgoff_t index)
177 struct lov_page *lpg = cl_object_page_slice(obj, page);
181 cl_page_slice_add(page, &lpg->lps_cl, obj, index, &lov_empty_page_ops);
182 addr = kmap(page->cp_vmpage);
183 memset(addr, 0, cl_page_size(obj));
184 kunmap(page->cp_vmpage);
185 cl_page_export(env, page, 1);