mm/hugetlb_cgroup.c

   1 /*
   2  *
   3  * Copyright IBM Corporation, 2012
   4  * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
   5  *
   6  * Cgroup v2
   7  * Copyright (C) 2019 Red Hat, Inc.
   8  * Author: Giuseppe Scrivano <gscrivan@redhat.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of version 2.1 of the GNU Lesser General Public License
  12  * as published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it would be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  17  *
  18  */
  19
  20 #include <linux/cgroup.h>
  21 #include <linux/page_counter.h>
  22 #include <linux/slab.h>
  23 #include <linux/hugetlb.h>
  24 #include <linux/hugetlb_cgroup.h>
  25
  26 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
  27 #define MEMFILE_IDX(val)        (((val) >> 16) & 0xffff)
  28 #define MEMFILE_ATTR(val)       ((val) & 0xffff)
  29
  30 static struct hugetlb_cgroup *root_h_cgroup __read_mostly;
  31
  32 static inline struct page_counter *
  33 __hugetlb_cgroup_counter_from_cgroup(struct hugetlb_cgroup *h_cg, int idx,
  34                                      bool rsvd)
  35 {
  36         if (rsvd)
  37                 return &h_cg->rsvd_hugepage[idx];
  38         return &h_cg->hugepage[idx];
  39 }
  40
  41 static inline struct page_counter *
  42 hugetlb_cgroup_counter_from_cgroup(struct hugetlb_cgroup *h_cg, int idx)
  43 {
  44         return __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, false);
  45 }
  46
  47 static inline struct page_counter *
  48 hugetlb_cgroup_counter_from_cgroup_rsvd(struct hugetlb_cgroup *h_cg, int idx)
  49 {
  50         return __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, true);
  51 }
  52
  53 static inline
  54 struct hugetlb_cgroup *hugetlb_cgroup_from_css(struct cgroup_subsys_state *s)
  55 {
  56         return s ? container_of(s, struct hugetlb_cgroup, css) : NULL;
  57 }
  58
  59 static inline
  60 struct hugetlb_cgroup *hugetlb_cgroup_from_task(struct task_struct *task)
  61 {
  62         return hugetlb_cgroup_from_css(task_css(task, hugetlb_cgrp_id));
  63 }
  64
  65 static inline bool hugetlb_cgroup_is_root(struct hugetlb_cgroup *h_cg)
  66 {
  67         return (h_cg == root_h_cgroup);
  68 }
  69
  70 static inline struct hugetlb_cgroup *
  71 parent_hugetlb_cgroup(struct hugetlb_cgroup *h_cg)
  72 {
  73         return hugetlb_cgroup_from_css(h_cg->css.parent);
  74 }
  75
  76 static inline bool hugetlb_cgroup_have_usage(struct hugetlb_cgroup *h_cg)
  77 {
  78         struct hstate *h;
  79
  80         for_each_hstate(h) {
  81                 if (page_counter_read(
  82                     hugetlb_cgroup_counter_from_cgroup(h_cg, hstate_index(h))))
  83                         return true;
  84         }
  85         return false;
  86 }
  87
  88 static void hugetlb_cgroup_init(struct hugetlb_cgroup *h_cgroup,
  89                                 struct hugetlb_cgroup *parent_h_cgroup)
  90 {
  91         int idx;
  92
  93         for (idx = 0; idx < HUGE_MAX_HSTATE; idx++) {
  94                 struct page_counter *fault_parent = NULL;
  95                 struct page_counter *rsvd_parent = NULL;
  96                 unsigned long limit;
  97                 int ret;
  98
  99                 if (parent_h_cgroup) {
 100                         fault_parent = hugetlb_cgroup_counter_from_cgroup(
 101                                 parent_h_cgroup, idx);
 102                         rsvd_parent = hugetlb_cgroup_counter_from_cgroup_rsvd(
 103                                 parent_h_cgroup, idx);
 104                 }
 105                 page_counter_init(hugetlb_cgroup_counter_from_cgroup(h_cgroup,
 106                                                                      idx),
 107                                   fault_parent);
 108                 page_counter_init(
 109                         hugetlb_cgroup_counter_from_cgroup_rsvd(h_cgroup, idx),
 110                         rsvd_parent);
 111
 112                 limit = round_down(PAGE_COUNTER_MAX,
 113                                    pages_per_huge_page(&hstates[idx]));
 114
 115                 ret = page_counter_set_max(
 116                         hugetlb_cgroup_counter_from_cgroup(h_cgroup, idx),
 117                         limit);
 118                 VM_BUG_ON(ret);
 119                 ret = page_counter_set_max(
 120                         hugetlb_cgroup_counter_from_cgroup_rsvd(h_cgroup, idx),
 121                         limit);
 122                 VM_BUG_ON(ret);
 123         }
 124 }
 125
 126 static void hugetlb_cgroup_free(struct hugetlb_cgroup *h_cgroup)
 127 {
 128         int node;
 129
 130         for_each_node(node)
 131                 kfree(h_cgroup->nodeinfo[node]);
 132         kfree(h_cgroup);
 133 }
 134
 135 static struct cgroup_subsys_state *
 136 hugetlb_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
 137 {
 138         struct hugetlb_cgroup *parent_h_cgroup = hugetlb_cgroup_from_css(parent_css);
 139         struct hugetlb_cgroup *h_cgroup;
 140         int node;
 141
 142         h_cgroup = kzalloc(struct_size(h_cgroup, nodeinfo, nr_node_ids),
 143                            GFP_KERNEL);
 144
 145         if (!h_cgroup)
 146                 return ERR_PTR(-ENOMEM);
 147
 148         if (!parent_h_cgroup)
 149                 root_h_cgroup = h_cgroup;
 150
 151         /*
 152          * TODO: this routine can waste much memory for nodes which will
 153          * never be onlined. It's better to use memory hotplug callback
 154          * function.
 155          */
 156         for_each_node(node) {
 157                 /* Set node_to_alloc to NUMA_NO_NODE for offline nodes. */
 158                 int node_to_alloc =
 159                         node_state(node, N_NORMAL_MEMORY) ? node : NUMA_NO_NODE;
 160                 h_cgroup->nodeinfo[node] =
 161                         kzalloc_node(sizeof(struct hugetlb_cgroup_per_node),
 162                                      GFP_KERNEL, node_to_alloc);
 163                 if (!h_cgroup->nodeinfo[node])
 164                         goto fail_alloc_nodeinfo;
 165         }
 166
 167         hugetlb_cgroup_init(h_cgroup, parent_h_cgroup);
 168         return &h_cgroup->css;
 169
 170 fail_alloc_nodeinfo:
 171         hugetlb_cgroup_free(h_cgroup);
 172         return ERR_PTR(-ENOMEM);
 173 }
 174
 175 static void hugetlb_cgroup_css_free(struct cgroup_subsys_state *css)
 176 {
 177         hugetlb_cgroup_free(hugetlb_cgroup_from_css(css));
 178 }
 179
 180 /*
 181  * Should be called with hugetlb_lock held.
 182  * Since we are holding hugetlb_lock, pages cannot get moved from
 183  * active list or uncharged from the cgroup, So no need to get
 184  * page reference and test for page active here. This function
 185  * cannot fail.
 186  */
 187 static void hugetlb_cgroup_move_parent(int idx, struct hugetlb_cgroup *h_cg,
 188                                        struct page *page)
 189 {
 190         unsigned int nr_pages;
 191         struct page_counter *counter;
 192         struct hugetlb_cgroup *page_hcg;
 193         struct hugetlb_cgroup *parent = parent_hugetlb_cgroup(h_cg);
 194         struct folio *folio = page_folio(page);
 195
 196         page_hcg = hugetlb_cgroup_from_folio(folio);
 197         /*
 198          * We can have pages in active list without any cgroup
 199          * ie, hugepage with less than 3 pages. We can safely
 200          * ignore those pages.
 201          */
 202         if (!page_hcg || page_hcg != h_cg)
 203                 goto out;
 204
 205         nr_pages = compound_nr(page);
 206         if (!parent) {
 207                 parent = root_h_cgroup;
 208                 /* root has no limit */
 209                 page_counter_charge(&parent->hugepage[idx], nr_pages);
 210         }
 211         counter = &h_cg->hugepage[idx];
 212         /* Take the pages off the local counter */
 213         page_counter_cancel(counter, nr_pages);
 214
 215         set_hugetlb_cgroup(folio, parent);
 216 out:
 217         return;
 218 }
 219
 220 /*
 221  * Force the hugetlb cgroup to empty the hugetlb resources by moving them to
 222  * the parent cgroup.
 223  */
 224 static void hugetlb_cgroup_css_offline(struct cgroup_subsys_state *css)
 225 {
 226         struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css);
 227         struct hstate *h;
 228         struct page *page;
 229
 230         do {
 231                 for_each_hstate(h) {
 232                         spin_lock_irq(&hugetlb_lock);
 233                         list_for_each_entry(page, &h->hugepage_activelist, lru)
 234                                 hugetlb_cgroup_move_parent(hstate_index(h), h_cg, page);
 235
 236                         spin_unlock_irq(&hugetlb_lock);
 237                 }
 238                 cond_resched();
 239         } while (hugetlb_cgroup_have_usage(h_cg));
 240 }
 241
 242 static inline void hugetlb_event(struct hugetlb_cgroup *hugetlb, int idx,
 243                                  enum hugetlb_memory_event event)
 244 {
 245         atomic_long_inc(&hugetlb->events_local[idx][event]);
 246         cgroup_file_notify(&hugetlb->events_local_file[idx]);
 247
 248         do {
 249                 atomic_long_inc(&hugetlb->events[idx][event]);
 250                 cgroup_file_notify(&hugetlb->events_file[idx]);
 251         } while ((hugetlb = parent_hugetlb_cgroup(hugetlb)) &&
 252                  !hugetlb_cgroup_is_root(hugetlb));
 253 }
 254
 255 static int __hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
 256                                           struct hugetlb_cgroup **ptr,
 257                                           bool rsvd)
 258 {
 259         int ret = 0;
 260         struct page_counter *counter;
 261         struct hugetlb_cgroup *h_cg = NULL;
 262
 263         if (hugetlb_cgroup_disabled())
 264                 goto done;
 265         /*
 266          * We don't charge any cgroup if the compound page have less
 267          * than 3 pages.
 268          */
 269         if (huge_page_order(&hstates[idx]) < HUGETLB_CGROUP_MIN_ORDER)
 270                 goto done;
 271 again:
 272         rcu_read_lock();
 273         h_cg = hugetlb_cgroup_from_task(current);
 274         if (!css_tryget(&h_cg->css)) {
 275                 rcu_read_unlock();
 276                 goto again;
 277         }
 278         rcu_read_unlock();
 279
 280         if (!page_counter_try_charge(
 281                     __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, rsvd),
 282                     nr_pages, &counter)) {
 283                 ret = -ENOMEM;
 284                 hugetlb_event(h_cg, idx, HUGETLB_MAX);
 285                 css_put(&h_cg->css);
 286                 goto done;
 287         }
 288         /* Reservations take a reference to the css because they do not get
 289          * reparented.
 290          */
 291         if (!rsvd)
 292                 css_put(&h_cg->css);
 293 done:
 294         *ptr = h_cg;
 295         return ret;
 296 }
 297
 298 int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
 299                                  struct hugetlb_cgroup **ptr)
 300 {
 301         return __hugetlb_cgroup_charge_cgroup(idx, nr_pages, ptr, false);
 302 }
 303
 304 int hugetlb_cgroup_charge_cgroup_rsvd(int idx, unsigned long nr_pages,
 305                                       struct hugetlb_cgroup **ptr)
 306 {
 307         return __hugetlb_cgroup_charge_cgroup(idx, nr_pages, ptr, true);
 308 }
 309
 310 /* Should be called with hugetlb_lock held */
 311 static void __hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
 312                                            struct hugetlb_cgroup *h_cg,
 313                                            struct folio *folio, bool rsvd)
 314 {
 315         if (hugetlb_cgroup_disabled() || !h_cg)
 316                 return;
 317
 318         __set_hugetlb_cgroup(folio, h_cg, rsvd);
 319         if (!rsvd) {
 320                 unsigned long usage =
 321                         h_cg->nodeinfo[folio_nid(folio)]->usage[idx];
 322                 /*
 323                  * This write is not atomic due to fetching usage and writing
 324                  * to it, but that's fine because we call this with
 325                  * hugetlb_lock held anyway.
 326                  */
 327                 WRITE_ONCE(h_cg->nodeinfo[folio_nid(folio)]->usage[idx],
 328                            usage + nr_pages);
 329         }
 330 }
 331
 332 void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
 333                                   struct hugetlb_cgroup *h_cg,
 334                                   struct folio *folio)
 335 {
 336         __hugetlb_cgroup_commit_charge(idx, nr_pages, h_cg, folio, false);
 337 }
 338
 339 void hugetlb_cgroup_commit_charge_rsvd(int idx, unsigned long nr_pages,
 340                                        struct hugetlb_cgroup *h_cg,
 341                                        struct folio *folio)
 342 {
 343         __hugetlb_cgroup_commit_charge(idx, nr_pages, h_cg, folio, true);
 344 }
 345
 346 /*
 347  * Should be called with hugetlb_lock held
 348  */
 349 static void __hugetlb_cgroup_uncharge_folio(int idx, unsigned long nr_pages,
 350                                            struct folio *folio, bool rsvd)
 351 {
 352         struct hugetlb_cgroup *h_cg;
 353
 354         if (hugetlb_cgroup_disabled())
 355                 return;
 356         lockdep_assert_held(&hugetlb_lock);
 357         h_cg = __hugetlb_cgroup_from_folio(folio, rsvd);
 358         if (unlikely(!h_cg))
 359                 return;
 360         __set_hugetlb_cgroup(folio, NULL, rsvd);
 361
 362         page_counter_uncharge(__hugetlb_cgroup_counter_from_cgroup(h_cg, idx,
 363                                                                    rsvd),
 364                               nr_pages);
 365
 366         if (rsvd)
 367                 css_put(&h_cg->css);
 368         else {
 369                 unsigned long usage =
 370                         h_cg->nodeinfo[folio_nid(folio)]->usage[idx];
 371                 /*
 372                  * This write is not atomic due to fetching usage and writing
 373                  * to it, but that's fine because we call this with
 374                  * hugetlb_lock held anyway.
 375                  */
 376                 WRITE_ONCE(h_cg->nodeinfo[folio_nid(folio)]->usage[idx],
 377                            usage - nr_pages);
 378         }
 379 }
 380
 381 void hugetlb_cgroup_uncharge_folio(int idx, unsigned long nr_pages,
 382                                   struct folio *folio)
 383 {
 384         __hugetlb_cgroup_uncharge_folio(idx, nr_pages, folio, false);
 385 }
 386
 387 void hugetlb_cgroup_uncharge_folio_rsvd(int idx, unsigned long nr_pages,
 388                                        struct folio *folio)
 389 {
 390         __hugetlb_cgroup_uncharge_folio(idx, nr_pages, folio, true);
 391 }
 392
 393 static void __hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
 394                                              struct hugetlb_cgroup *h_cg,
 395                                              bool rsvd)
 396 {
 397         if (hugetlb_cgroup_disabled() || !h_cg)
 398                 return;
 399
 400         if (huge_page_order(&hstates[idx]) < HUGETLB_CGROUP_MIN_ORDER)
 401                 return;
 402
 403         page_counter_uncharge(__hugetlb_cgroup_counter_from_cgroup(h_cg, idx,
 404                                                                    rsvd),
 405                               nr_pages);
 406
 407         if (rsvd)
 408                 css_put(&h_cg->css);
 409 }
 410
 411 void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
 412                                     struct hugetlb_cgroup *h_cg)
 413 {
 414         __hugetlb_cgroup_uncharge_cgroup(idx, nr_pages, h_cg, false);
 415 }
 416
 417 void hugetlb_cgroup_uncharge_cgroup_rsvd(int idx, unsigned long nr_pages,
 418                                          struct hugetlb_cgroup *h_cg)
 419 {
 420         __hugetlb_cgroup_uncharge_cgroup(idx, nr_pages, h_cg, true);
 421 }
 422
 423 void hugetlb_cgroup_uncharge_counter(struct resv_map *resv, unsigned long start,
 424                                      unsigned long end)
 425 {
 426         if (hugetlb_cgroup_disabled() || !resv || !resv->reservation_counter ||
 427             !resv->css)
 428                 return;
 429
 430         page_counter_uncharge(resv->reservation_counter,
 431                               (end - start) * resv->pages_per_hpage);
 432         css_put(resv->css);
 433 }
 434
 435 void hugetlb_cgroup_uncharge_file_region(struct resv_map *resv,
 436                                          struct file_region *rg,
 437                                          unsigned long nr_pages,
 438                                          bool region_del)
 439 {
 440         if (hugetlb_cgroup_disabled() || !resv || !rg || !nr_pages)
 441                 return;
 442
 443         if (rg->reservation_counter && resv->pages_per_hpage &&
 444             !resv->reservation_counter) {
 445                 page_counter_uncharge(rg->reservation_counter,
 446                                       nr_pages * resv->pages_per_hpage);
 447                 /*
 448                  * Only do css_put(rg->css) when we delete the entire region
 449                  * because one file_region must hold exactly one css reference.
 450                  */
 451                 if (region_del)
 452                         css_put(rg->css);
 453         }
 454 }
 455
 456 enum {
 457         RES_USAGE,
 458         RES_RSVD_USAGE,
 459         RES_LIMIT,
 460         RES_RSVD_LIMIT,
 461         RES_MAX_USAGE,
 462         RES_RSVD_MAX_USAGE,
 463         RES_FAILCNT,
 464         RES_RSVD_FAILCNT,
 465 };
 466
 467 static int hugetlb_cgroup_read_numa_stat(struct seq_file *seq, void *dummy)
 468 {
 469         int nid;
 470         struct cftype *cft = seq_cft(seq);
 471         int idx = MEMFILE_IDX(cft->private);
 472         bool legacy = MEMFILE_ATTR(cft->private);
 473         struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(seq_css(seq));
 474         struct cgroup_subsys_state *css;
 475         unsigned long usage;
 476
 477         if (legacy) {
 478                 /* Add up usage across all nodes for the non-hierarchical total. */
 479                 usage = 0;
 480                 for_each_node_state(nid, N_MEMORY)
 481                         usage += READ_ONCE(h_cg->nodeinfo[nid]->usage[idx]);
 482                 seq_printf(seq, "total=%lu", usage * PAGE_SIZE);
 483
 484                 /* Simply print the per-node usage for the non-hierarchical total. */
 485                 for_each_node_state(nid, N_MEMORY)
 486                         seq_printf(seq, " N%d=%lu", nid,
 487                                    READ_ONCE(h_cg->nodeinfo[nid]->usage[idx]) *
 488                                            PAGE_SIZE);
 489                 seq_putc(seq, '\n');
 490         }
 491
 492         /*
 493          * The hierarchical total is pretty much the value recorded by the
 494          * counter, so use that.
 495          */
 496         seq_printf(seq, "%stotal=%lu", legacy ? "hierarchical_" : "",
 497                    page_counter_read(&h_cg->hugepage[idx]) * PAGE_SIZE);
 498
 499         /*
 500          * For each node, transverse the css tree to obtain the hierarchical
 501          * node usage.
 502          */
 503         for_each_node_state(nid, N_MEMORY) {
 504                 usage = 0;
 505                 rcu_read_lock();
 506                 css_for_each_descendant_pre(css, &h_cg->css) {
 507                         usage += READ_ONCE(hugetlb_cgroup_from_css(css)
 508                                                    ->nodeinfo[nid]
 509                                                    ->usage[idx]);
 510                 }
 511                 rcu_read_unlock();
 512                 seq_printf(seq, " N%d=%lu", nid, usage * PAGE_SIZE);
 513         }
 514
 515         seq_putc(seq, '\n');
 516
 517         return 0;
 518 }
 519
 520 static u64 hugetlb_cgroup_read_u64(struct cgroup_subsys_state *css,
 521                                    struct cftype *cft)
 522 {
 523         struct page_counter *counter;
 524         struct page_counter *rsvd_counter;
 525         struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css);
 526
 527         counter = &h_cg->hugepage[MEMFILE_IDX(cft->private)];
 528         rsvd_counter = &h_cg->rsvd_hugepage[MEMFILE_IDX(cft->private)];
 529
 530         switch (MEMFILE_ATTR(cft->private)) {
 531         case RES_USAGE:
 532                 return (u64)page_counter_read(counter) * PAGE_SIZE;
 533         case RES_RSVD_USAGE:
 534                 return (u64)page_counter_read(rsvd_counter) * PAGE_SIZE;
 535         case RES_LIMIT:
 536                 return (u64)counter->max * PAGE_SIZE;
 537         case RES_RSVD_LIMIT:
 538                 return (u64)rsvd_counter->max * PAGE_SIZE;
 539         case RES_MAX_USAGE:
 540                 return (u64)counter->watermark * PAGE_SIZE;
 541         case RES_RSVD_MAX_USAGE:
 542                 return (u64)rsvd_counter->watermark * PAGE_SIZE;
 543         case RES_FAILCNT:
 544                 return counter->failcnt;
 545         case RES_RSVD_FAILCNT:
 546                 return rsvd_counter->failcnt;
 547         default:
 548                 BUG();
 549         }
 550 }
 551
 552 static int hugetlb_cgroup_read_u64_max(struct seq_file *seq, void *v)
 553 {
 554         int idx;
 555         u64 val;
 556         struct cftype *cft = seq_cft(seq);
 557         unsigned long limit;
 558         struct page_counter *counter;
 559         struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(seq_css(seq));
 560
 561         idx = MEMFILE_IDX(cft->private);
 562         counter = &h_cg->hugepage[idx];
 563
 564         limit = round_down(PAGE_COUNTER_MAX,
 565                            pages_per_huge_page(&hstates[idx]));
 566
 567         switch (MEMFILE_ATTR(cft->private)) {
 568         case RES_RSVD_USAGE:
 569                 counter = &h_cg->rsvd_hugepage[idx];
 570                 fallthrough;
 571         case RES_USAGE:
 572                 val = (u64)page_counter_read(counter);
 573                 seq_printf(seq, "%llu\n", val * PAGE_SIZE);
 574                 break;
 575         case RES_RSVD_LIMIT:
 576                 counter = &h_cg->rsvd_hugepage[idx];
 577                 fallthrough;
 578         case RES_LIMIT:
 579                 val = (u64)counter->max;
 580                 if (val == limit)
 581                         seq_puts(seq, "max\n");
 582                 else
 583                         seq_printf(seq, "%llu\n", val * PAGE_SIZE);
 584                 break;
 585         default:
 586                 BUG();
 587         }
 588
 589         return 0;
 590 }
 591
 592 static DEFINE_MUTEX(hugetlb_limit_mutex);
 593
 594 static ssize_t hugetlb_cgroup_write(struct kernfs_open_file *of,
 595                                     char *buf, size_t nbytes, loff_t off,
 596                                     const char *max)
 597 {
 598         int ret, idx;
 599         unsigned long nr_pages;
 600         struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of));
 601         bool rsvd = false;
 602
 603         if (hugetlb_cgroup_is_root(h_cg)) /* Can't set limit on root */
 604                 return -EINVAL;
 605
 606         buf = strstrip(buf);
 607         ret = page_counter_memparse(buf, max, &nr_pages);
 608         if (ret)
 609                 return ret;
 610
 611         idx = MEMFILE_IDX(of_cft(of)->private);
 612         nr_pages = round_down(nr_pages, pages_per_huge_page(&hstates[idx]));
 613
 614         switch (MEMFILE_ATTR(of_cft(of)->private)) {
 615         case RES_RSVD_LIMIT:
 616                 rsvd = true;
 617                 fallthrough;
 618         case RES_LIMIT:
 619                 mutex_lock(&hugetlb_limit_mutex);
 620                 ret = page_counter_set_max(
 621                         __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, rsvd),
 622                         nr_pages);
 623                 mutex_unlock(&hugetlb_limit_mutex);
 624                 break;
 625         default:
 626                 ret = -EINVAL;
 627                 break;
 628         }
 629         return ret ?: nbytes;
 630 }
 631
 632 static ssize_t hugetlb_cgroup_write_legacy(struct kernfs_open_file *of,
 633                                            char *buf, size_t nbytes, loff_t off)
 634 {
 635         return hugetlb_cgroup_write(of, buf, nbytes, off, "-1");
 636 }
 637
 638 static ssize_t hugetlb_cgroup_write_dfl(struct kernfs_open_file *of,
 639                                         char *buf, size_t nbytes, loff_t off)
 640 {
 641         return hugetlb_cgroup_write(of, buf, nbytes, off, "max");
 642 }
 643
 644 static ssize_t hugetlb_cgroup_reset(struct kernfs_open_file *of,
 645                                     char *buf, size_t nbytes, loff_t off)
 646 {
 647         int ret = 0;
 648         struct page_counter *counter, *rsvd_counter;
 649         struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of));
 650
 651         counter = &h_cg->hugepage[MEMFILE_IDX(of_cft(of)->private)];
 652         rsvd_counter = &h_cg->rsvd_hugepage[MEMFILE_IDX(of_cft(of)->private)];
 653
 654         switch (MEMFILE_ATTR(of_cft(of)->private)) {
 655         case RES_MAX_USAGE:
 656                 page_counter_reset_watermark(counter);
 657                 break;
 658         case RES_RSVD_MAX_USAGE:
 659                 page_counter_reset_watermark(rsvd_counter);
 660                 break;
 661         case RES_FAILCNT:
 662                 counter->failcnt = 0;
 663                 break;
 664         case RES_RSVD_FAILCNT:
 665                 rsvd_counter->failcnt = 0;
 666                 break;
 667         default:
 668                 ret = -EINVAL;
 669                 break;
 670         }
 671         return ret ?: nbytes;
 672 }
 673
 674 static char *mem_fmt(char *buf, int size, unsigned long hsize)
 675 {
 676         if (hsize >= SZ_1G)
 677                 snprintf(buf, size, "%luGB", hsize / SZ_1G);
 678         else if (hsize >= SZ_1M)
 679                 snprintf(buf, size, "%luMB", hsize / SZ_1M);
 680         else
 681                 snprintf(buf, size, "%luKB", hsize / SZ_1K);
 682         return buf;
 683 }
 684
 685 static int __hugetlb_events_show(struct seq_file *seq, bool local)
 686 {
 687         int idx;
 688         long max;
 689         struct cftype *cft = seq_cft(seq);
 690         struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(seq_css(seq));
 691
 692         idx = MEMFILE_IDX(cft->private);
 693
 694         if (local)
 695                 max = atomic_long_read(&h_cg->events_local[idx][HUGETLB_MAX]);
 696         else
 697                 max = atomic_long_read(&h_cg->events[idx][HUGETLB_MAX]);
 698
 699         seq_printf(seq, "max %lu\n", max);
 700
 701         return 0;
 702 }
 703
 704 static int hugetlb_events_show(struct seq_file *seq, void *v)
 705 {
 706         return __hugetlb_events_show(seq, false);
 707 }
 708
 709 static int hugetlb_events_local_show(struct seq_file *seq, void *v)
 710 {
 711         return __hugetlb_events_show(seq, true);
 712 }
 713
 714 static void __init __hugetlb_cgroup_file_dfl_init(int idx)
 715 {
 716         char buf[32];
 717         struct cftype *cft;
 718         struct hstate *h = &hstates[idx];
 719
 720         /* format the size */
 721         mem_fmt(buf, sizeof(buf), huge_page_size(h));
 722
 723         /* Add the limit file */
 724         cft = &h->cgroup_files_dfl[0];
 725         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.max", buf);
 726         cft->private = MEMFILE_PRIVATE(idx, RES_LIMIT);
 727         cft->seq_show = hugetlb_cgroup_read_u64_max;
 728         cft->write = hugetlb_cgroup_write_dfl;
 729         cft->flags = CFTYPE_NOT_ON_ROOT;
 730
 731         /* Add the reservation limit file */
 732         cft = &h->cgroup_files_dfl[1];
 733         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.max", buf);
 734         cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_LIMIT);
 735         cft->seq_show = hugetlb_cgroup_read_u64_max;
 736         cft->write = hugetlb_cgroup_write_dfl;
 737         cft->flags = CFTYPE_NOT_ON_ROOT;
 738
 739         /* Add the current usage file */
 740         cft = &h->cgroup_files_dfl[2];
 741         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.current", buf);
 742         cft->private = MEMFILE_PRIVATE(idx, RES_USAGE);
 743         cft->seq_show = hugetlb_cgroup_read_u64_max;
 744         cft->flags = CFTYPE_NOT_ON_ROOT;
 745
 746         /* Add the current reservation usage file */
 747         cft = &h->cgroup_files_dfl[3];
 748         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.current", buf);
 749         cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_USAGE);
 750         cft->seq_show = hugetlb_cgroup_read_u64_max;
 751         cft->flags = CFTYPE_NOT_ON_ROOT;
 752
 753         /* Add the events file */
 754         cft = &h->cgroup_files_dfl[4];
 755         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.events", buf);
 756         cft->private = MEMFILE_PRIVATE(idx, 0);
 757         cft->seq_show = hugetlb_events_show;
 758         cft->file_offset = offsetof(struct hugetlb_cgroup, events_file[idx]);
 759         cft->flags = CFTYPE_NOT_ON_ROOT;
 760
 761         /* Add the events.local file */
 762         cft = &h->cgroup_files_dfl[5];
 763         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.events.local", buf);
 764         cft->private = MEMFILE_PRIVATE(idx, 0);
 765         cft->seq_show = hugetlb_events_local_show;
 766         cft->file_offset = offsetof(struct hugetlb_cgroup,
 767                                     events_local_file[idx]);
 768         cft->flags = CFTYPE_NOT_ON_ROOT;
 769
 770         /* Add the numa stat file */
 771         cft = &h->cgroup_files_dfl[6];
 772         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.numa_stat", buf);
 773         cft->private = MEMFILE_PRIVATE(idx, 0);
 774         cft->seq_show = hugetlb_cgroup_read_numa_stat;
 775         cft->flags = CFTYPE_NOT_ON_ROOT;
 776
 777         /* NULL terminate the last cft */
 778         cft = &h->cgroup_files_dfl[7];
 779         memset(cft, 0, sizeof(*cft));
 780
 781         WARN_ON(cgroup_add_dfl_cftypes(&hugetlb_cgrp_subsys,
 782                                        h->cgroup_files_dfl));
 783 }
 784
 785 static void __init __hugetlb_cgroup_file_legacy_init(int idx)
 786 {
 787         char buf[32];
 788         struct cftype *cft;
 789         struct hstate *h = &hstates[idx];
 790
 791         /* format the size */
 792         mem_fmt(buf, sizeof(buf), huge_page_size(h));
 793
 794         /* Add the limit file */
 795         cft = &h->cgroup_files_legacy[0];
 796         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.limit_in_bytes", buf);
 797         cft->private = MEMFILE_PRIVATE(idx, RES_LIMIT);
 798         cft->read_u64 = hugetlb_cgroup_read_u64;
 799         cft->write = hugetlb_cgroup_write_legacy;
 800
 801         /* Add the reservation limit file */
 802         cft = &h->cgroup_files_legacy[1];
 803         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.limit_in_bytes", buf);
 804         cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_LIMIT);
 805         cft->read_u64 = hugetlb_cgroup_read_u64;
 806         cft->write = hugetlb_cgroup_write_legacy;
 807
 808         /* Add the usage file */
 809         cft = &h->cgroup_files_legacy[2];
 810         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.usage_in_bytes", buf);
 811         cft->private = MEMFILE_PRIVATE(idx, RES_USAGE);
 812         cft->read_u64 = hugetlb_cgroup_read_u64;
 813
 814         /* Add the reservation usage file */
 815         cft = &h->cgroup_files_legacy[3];
 816         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.usage_in_bytes", buf);
 817         cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_USAGE);
 818         cft->read_u64 = hugetlb_cgroup_read_u64;
 819
 820         /* Add the MAX usage file */
 821         cft = &h->cgroup_files_legacy[4];
 822         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.max_usage_in_bytes", buf);
 823         cft->private = MEMFILE_PRIVATE(idx, RES_MAX_USAGE);
 824         cft->write = hugetlb_cgroup_reset;
 825         cft->read_u64 = hugetlb_cgroup_read_u64;
 826
 827         /* Add the MAX reservation usage file */
 828         cft = &h->cgroup_files_legacy[5];
 829         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.max_usage_in_bytes", buf);
 830         cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_MAX_USAGE);
 831         cft->write = hugetlb_cgroup_reset;
 832         cft->read_u64 = hugetlb_cgroup_read_u64;
 833
 834         /* Add the failcntfile */
 835         cft = &h->cgroup_files_legacy[6];
 836         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.failcnt", buf);
 837         cft->private = MEMFILE_PRIVATE(idx, RES_FAILCNT);
 838         cft->write = hugetlb_cgroup_reset;
 839         cft->read_u64 = hugetlb_cgroup_read_u64;
 840
 841         /* Add the reservation failcntfile */
 842         cft = &h->cgroup_files_legacy[7];
 843         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.failcnt", buf);
 844         cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_FAILCNT);
 845         cft->write = hugetlb_cgroup_reset;
 846         cft->read_u64 = hugetlb_cgroup_read_u64;
 847
 848         /* Add the numa stat file */
 849         cft = &h->cgroup_files_legacy[8];
 850         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.numa_stat", buf);
 851         cft->private = MEMFILE_PRIVATE(idx, 1);
 852         cft->seq_show = hugetlb_cgroup_read_numa_stat;
 853
 854         /* NULL terminate the last cft */
 855         cft = &h->cgroup_files_legacy[9];
 856         memset(cft, 0, sizeof(*cft));
 857
 858         WARN_ON(cgroup_add_legacy_cftypes(&hugetlb_cgrp_subsys,
 859                                           h->cgroup_files_legacy));
 860 }
 861
 862 static void __init __hugetlb_cgroup_file_init(int idx)
 863 {
 864         __hugetlb_cgroup_file_dfl_init(idx);
 865         __hugetlb_cgroup_file_legacy_init(idx);
 866 }
 867
 868 void __init hugetlb_cgroup_file_init(void)
 869 {
 870         struct hstate *h;
 871
 872         for_each_hstate(h) {
 873                 /*
 874                  * Add cgroup control files only if the huge page consists
 875                  * of more than two normal pages. This is because we use
 876                  * page[2].private for storing cgroup details.
 877                  */
 878                 if (huge_page_order(h) >= HUGETLB_CGROUP_MIN_ORDER)
 879                         __hugetlb_cgroup_file_init(hstate_index(h));
 880         }
 881 }
 882
 883 /*
 884  * hugetlb_lock will make sure a parallel cgroup rmdir won't happen
 885  * when we migrate hugepages
 886  */
 887 void hugetlb_cgroup_migrate(struct folio *old_folio, struct folio *new_folio)
 888 {
 889         struct hugetlb_cgroup *h_cg;
 890         struct hugetlb_cgroup *h_cg_rsvd;
 891         struct hstate *h = folio_hstate(old_folio);
 892
 893         if (hugetlb_cgroup_disabled())
 894                 return;
 895
 896         spin_lock_irq(&hugetlb_lock);
 897         h_cg = hugetlb_cgroup_from_folio(old_folio);
 898         h_cg_rsvd = hugetlb_cgroup_from_folio_rsvd(old_folio);
 899         set_hugetlb_cgroup(old_folio, NULL);
 900         set_hugetlb_cgroup_rsvd(old_folio, NULL);
 901
 902         /* move the h_cg details to new cgroup */
 903         set_hugetlb_cgroup(new_folio, h_cg);
 904         set_hugetlb_cgroup_rsvd(new_folio, h_cg_rsvd);
 905         list_move(&new_folio->lru, &h->hugepage_activelist);
 906         spin_unlock_irq(&hugetlb_lock);
 907         return;
 908 }
 909
 910 static struct cftype hugetlb_files[] = {
 911         {} /* terminate */
 912 };
 913
 914 struct cgroup_subsys hugetlb_cgrp_subsys = {
 915         .css_alloc      = hugetlb_cgroup_css_alloc,
 916         .css_offline    = hugetlb_cgroup_css_offline,
 917         .css_free       = hugetlb_cgroup_css_free,
 918         .dfl_cftypes    = hugetlb_files,
 919         .legacy_cftypes = hugetlb_files,
 920 };