1 /* 2 * hugetlbpage-backed filesystem. Based on ramfs. 3 * 4 * Nadia Yvette Chambers, 2002 5 * 6 * Copyright (C) 2002 Linus Torvalds. 7 * License: GPL 8 */ 9 10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 11 12 #include <linux/thread_info.h> 13 #include <asm/current.h> 14 #include <linux/sched/signal.h> /* remove ASAP */ 15 #include <linux/falloc.h> 16 #include <linux/fs.h> 17 #include <linux/mount.h> 18 #include <linux/file.h> 19 #include <linux/kernel.h> 20 #include <linux/writeback.h> 21 #include <linux/pagemap.h> 22 #include <linux/highmem.h> 23 #include <linux/init.h> 24 #include <linux/string.h> 25 #include <linux/capability.h> 26 #include <linux/ctype.h> 27 #include <linux/backing-dev.h> 28 #include <linux/hugetlb.h> 29 #include <linux/pagevec.h> 30 #include <linux/parser.h> 31 #include <linux/mman.h> 32 #include <linux/slab.h> 33 #include <linux/dnotify.h> 34 #include <linux/statfs.h> 35 #include <linux/security.h> 36 #include <linux/magic.h> 37 #include <linux/migrate.h> 38 #include <linux/uio.h> 39 40 #include <linux/uaccess.h> 41 42 static const struct super_operations hugetlbfs_ops; 43 static const struct address_space_operations hugetlbfs_aops; 44 const struct file_operations hugetlbfs_file_operations; 45 static const struct inode_operations hugetlbfs_dir_inode_operations; 46 static const struct inode_operations hugetlbfs_inode_operations; 47 48 struct hugetlbfs_config { 49 struct hstate *hstate; 50 long max_hpages; 51 long nr_inodes; 52 long min_hpages; 53 kuid_t uid; 54 kgid_t gid; 55 umode_t mode; 56 }; 57 58 struct hugetlbfs_inode_info { 59 struct shared_policy policy; 60 struct inode vfs_inode; 61 }; 62 63 static inline struct hugetlbfs_inode_info *HUGETLBFS_I(struct inode *inode) 64 { 65 return container_of(inode, struct hugetlbfs_inode_info, vfs_inode); 66 } 67 68 int sysctl_hugetlb_shm_group; 69 70 enum { 71 Opt_size, Opt_nr_inodes, 72 Opt_mode, Opt_uid, Opt_gid, 73 Opt_pagesize, Opt_min_size, 74 Opt_err, 75 }; 76 77 static const match_table_t tokens = { 78 {Opt_size, "size=%s"}, 79 {Opt_nr_inodes, "nr_inodes=%s"}, 80 {Opt_mode, "mode=%o"}, 81 {Opt_uid, "uid=%u"}, 82 {Opt_gid, "gid=%u"}, 83 {Opt_pagesize, "pagesize=%s"}, 84 {Opt_min_size, "min_size=%s"}, 85 {Opt_err, NULL}, 86 }; 87 88 #ifdef CONFIG_NUMA 89 static inline void hugetlb_set_vma_policy(struct vm_area_struct *vma, 90 struct inode *inode, pgoff_t index) 91 { 92 vma->vm_policy = mpol_shared_policy_lookup(&HUGETLBFS_I(inode)->policy, 93 index); 94 } 95 96 static inline void hugetlb_drop_vma_policy(struct vm_area_struct *vma) 97 { 98 mpol_cond_put(vma->vm_policy); 99 } 100 #else 101 static inline void hugetlb_set_vma_policy(struct vm_area_struct *vma, 102 struct inode *inode, pgoff_t index) 103 { 104 } 105 106 static inline void hugetlb_drop_vma_policy(struct vm_area_struct *vma) 107 { 108 } 109 #endif 110 111 static void huge_pagevec_release(struct pagevec *pvec) 112 { 113 int i; 114 115 for (i = 0; i < pagevec_count(pvec); ++i) 116 put_page(pvec->pages[i]); 117 118 pagevec_reinit(pvec); 119 } 120 121 static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma) 122 { 123 struct inode *inode = file_inode(file); 124 loff_t len, vma_len; 125 int ret; 126 struct hstate *h = hstate_file(file); 127 128 /* 129 * vma address alignment (but not the pgoff alignment) has 130 * already been checked by prepare_hugepage_range. If you add 131 * any error returns here, do so after setting VM_HUGETLB, so 132 * is_vm_hugetlb_page tests below unmap_region go the right 133 * way when do_mmap_pgoff unwinds (may be important on powerpc 134 * and ia64). 135 */ 136 vma->vm_flags |= VM_HUGETLB | VM_DONTEXPAND; 137 vma->vm_ops = &hugetlb_vm_ops; 138 139 /* 140 * Offset passed to mmap (before page shift) could have been 141 * negative when represented as a (l)off_t. 142 */ 143 if (((loff_t)vma->vm_pgoff << PAGE_SHIFT) < 0) 144 return -EINVAL; 145 146 if (vma->vm_pgoff & (~huge_page_mask(h) >> PAGE_SHIFT)) 147 return -EINVAL; 148 149 vma_len = (loff_t)(vma->vm_end - vma->vm_start); 150 len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); 151 /* check for overflow */ 152 if (len < vma_len) 153 return -EINVAL; 154 155 inode_lock(inode); 156 file_accessed(file); 157 158 ret = -ENOMEM; 159 if (hugetlb_reserve_pages(inode, 160 vma->vm_pgoff >> huge_page_order(h), 161 len >> huge_page_shift(h), vma, 162 vma->vm_flags)) 163 goto out; 164 165 ret = 0; 166 if (vma->vm_flags & VM_WRITE && inode->i_size < len) 167 i_size_write(inode, len); 168 out: 169 inode_unlock(inode); 170 171 return ret; 172 } 173 174 /* 175 * Called under down_write(mmap_sem). 176 */ 177 178 #ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA 179 static unsigned long 180 hugetlb_get_unmapped_area(struct file *file, unsigned long addr, 181 unsigned long len, unsigned long pgoff, unsigned long flags) 182 { 183 struct mm_struct *mm = current->mm; 184 struct vm_area_struct *vma; 185 struct hstate *h = hstate_file(file); 186 struct vm_unmapped_area_info info; 187 188 if (len & ~huge_page_mask(h)) 189 return -EINVAL; 190 if (len > TASK_SIZE) 191 return -ENOMEM; 192 193 if (flags & MAP_FIXED) { 194 if (prepare_hugepage_range(file, addr, len)) 195 return -EINVAL; 196 return addr; 197 } 198 199 if (addr) { 200 addr = ALIGN(addr, huge_page_size(h)); 201 vma = find_vma(mm, addr); 202 if (TASK_SIZE - len >= addr && 203 (!vma || addr + len <= vm_start_gap(vma))) 204 return addr; 205 } 206 207 info.flags = 0; 208 info.length = len; 209 info.low_limit = TASK_UNMAPPED_BASE; 210 info.high_limit = TASK_SIZE; 211 info.align_mask = PAGE_MASK & ~huge_page_mask(h); 212 info.align_offset = 0; 213 return vm_unmapped_area(&info); 214 } 215 #endif 216 217 static size_t 218 hugetlbfs_read_actor(struct page *page, unsigned long offset, 219 struct iov_iter *to, unsigned long size) 220 { 221 size_t copied = 0; 222 int i, chunksize; 223 224 /* Find which 4k chunk and offset with in that chunk */ 225 i = offset >> PAGE_SHIFT; 226 offset = offset & ~PAGE_MASK; 227 228 while (size) { 229 size_t n; 230 chunksize = PAGE_SIZE; 231 if (offset) 232 chunksize -= offset; 233 if (chunksize > size) 234 chunksize = size; 235 n = copy_page_to_iter(&page[i], offset, chunksize, to); 236 copied += n; 237 if (n != chunksize) 238 return copied; 239 offset = 0; 240 size -= chunksize; 241 i++; 242 } 243 return copied; 244 } 245 246 /* 247 * Support for read() - Find the page attached to f_mapping and copy out the 248 * data. Its *very* similar to do_generic_mapping_read(), we can't use that 249 * since it has PAGE_SIZE assumptions. 250 */ 251 static ssize_t hugetlbfs_read_iter(struct kiocb *iocb, struct iov_iter *to) 252 { 253 struct file *file = iocb->ki_filp; 254 struct hstate *h = hstate_file(file); 255 struct address_space *mapping = file->f_mapping; 256 struct inode *inode = mapping->host; 257 unsigned long index = iocb->ki_pos >> huge_page_shift(h); 258 unsigned long offset = iocb->ki_pos & ~huge_page_mask(h); 259 unsigned long end_index; 260 loff_t isize; 261 ssize_t retval = 0; 262 263 while (iov_iter_count(to)) { 264 struct page *page; 265 size_t nr, copied; 266 267 /* nr is the maximum number of bytes to copy from this page */ 268 nr = huge_page_size(h); 269 isize = i_size_read(inode); 270 if (!isize) 271 break; 272 end_index = (isize - 1) >> huge_page_shift(h); 273 if (index > end_index) 274 break; 275 if (index == end_index) { 276 nr = ((isize - 1) & ~huge_page_mask(h)) + 1; 277 if (nr <= offset) 278 break; 279 } 280 nr = nr - offset; 281 282 /* Find the page */ 283 page = find_lock_page(mapping, index); 284 if (unlikely(page == NULL)) { 285 /* 286 * We have a HOLE, zero out the user-buffer for the 287 * length of the hole or request. 288 */ 289 copied = iov_iter_zero(nr, to); 290 } else { 291 unlock_page(page); 292 293 /* 294 * We have the page, copy it to user space buffer. 295 */ 296 copied = hugetlbfs_read_actor(page, offset, to, nr); 297 put_page(page); 298 } 299 offset += copied; 300 retval += copied; 301 if (copied != nr && iov_iter_count(to)) { 302 if (!retval) 303 retval = -EFAULT; 304 break; 305 } 306 index += offset >> huge_page_shift(h); 307 offset &= ~huge_page_mask(h); 308 } 309 iocb->ki_pos = ((loff_t)index << huge_page_shift(h)) + offset; 310 return retval; 311 } 312 313 static int hugetlbfs_write_begin(struct file *file, 314 struct address_space *mapping, 315 loff_t pos, unsigned len, unsigned flags, 316 struct page **pagep, void **fsdata) 317 { 318 return -EINVAL; 319 } 320 321 static int hugetlbfs_write_end(struct file *file, struct address_space *mapping, 322 loff_t pos, unsigned len, unsigned copied, 323 struct page *page, void *fsdata) 324 { 325 BUG(); 326 return -EINVAL; 327 } 328 329 static void remove_huge_page(struct page *page) 330 { 331 ClearPageDirty(page); 332 ClearPageUptodate(page); 333 delete_from_page_cache(page); 334 } 335 336 static void 337 hugetlb_vmdelete_list(struct rb_root *root, pgoff_t start, pgoff_t end) 338 { 339 struct vm_area_struct *vma; 340 341 /* 342 * end == 0 indicates that the entire range after 343 * start should be unmapped. 344 */ 345 vma_interval_tree_foreach(vma, root, start, end ? end : ULONG_MAX) { 346 unsigned long v_offset; 347 unsigned long v_end; 348 349 /* 350 * Can the expression below overflow on 32-bit arches? 351 * No, because the interval tree returns us only those vmas 352 * which overlap the truncated area starting at pgoff, 353 * and no vma on a 32-bit arch can span beyond the 4GB. 354 */ 355 if (vma->vm_pgoff < start) 356 v_offset = (start - vma->vm_pgoff) << PAGE_SHIFT; 357 else 358 v_offset = 0; 359 360 if (!end) 361 v_end = vma->vm_end; 362 else { 363 v_end = ((end - vma->vm_pgoff) << PAGE_SHIFT) 364 + vma->vm_start; 365 if (v_end > vma->vm_end) 366 v_end = vma->vm_end; 367 } 368 369 unmap_hugepage_range(vma, vma->vm_start + v_offset, v_end, 370 NULL); 371 } 372 } 373 374 /* 375 * remove_inode_hugepages handles two distinct cases: truncation and hole 376 * punch. There are subtle differences in operation for each case. 377 * 378 * truncation is indicated by end of range being LLONG_MAX 379 * In this case, we first scan the range and release found pages. 380 * After releasing pages, hugetlb_unreserve_pages cleans up region/reserv 381 * maps and global counts. Page faults can not race with truncation 382 * in this routine. hugetlb_no_page() prevents page faults in the 383 * truncated range. It checks i_size before allocation, and again after 384 * with the page table lock for the page held. The same lock must be 385 * acquired to unmap a page. 386 * hole punch is indicated if end is not LLONG_MAX 387 * In the hole punch case we scan the range and release found pages. 388 * Only when releasing a page is the associated region/reserv map 389 * deleted. The region/reserv map for ranges without associated 390 * pages are not modified. Page faults can race with hole punch. 391 * This is indicated if we find a mapped page. 392 * Note: If the passed end of range value is beyond the end of file, but 393 * not LLONG_MAX this routine still performs a hole punch operation. 394 */ 395 static void remove_inode_hugepages(struct inode *inode, loff_t lstart, 396 loff_t lend) 397 { 398 struct hstate *h = hstate_inode(inode); 399 struct address_space *mapping = &inode->i_data; 400 const pgoff_t start = lstart >> huge_page_shift(h); 401 const pgoff_t end = lend >> huge_page_shift(h); 402 struct vm_area_struct pseudo_vma; 403 struct pagevec pvec; 404 pgoff_t next; 405 int i, freed = 0; 406 long lookup_nr = PAGEVEC_SIZE; 407 bool truncate_op = (lend == LLONG_MAX); 408 409 memset(&pseudo_vma, 0, sizeof(struct vm_area_struct)); 410 pseudo_vma.vm_flags = (VM_HUGETLB | VM_MAYSHARE | VM_SHARED); 411 pagevec_init(&pvec, 0); 412 next = start; 413 while (next < end) { 414 /* 415 * Don't grab more pages than the number left in the range. 416 */ 417 if (end - next < lookup_nr) 418 lookup_nr = end - next; 419 420 /* 421 * When no more pages are found, we are done. 422 */ 423 if (!pagevec_lookup(&pvec, mapping, next, lookup_nr)) 424 break; 425 426 for (i = 0; i < pagevec_count(&pvec); ++i) { 427 struct page *page = pvec.pages[i]; 428 u32 hash; 429 430 /* 431 * The page (index) could be beyond end. This is 432 * only possible in the punch hole case as end is 433 * max page offset in the truncate case. 434 */ 435 next = page->index; 436 if (next >= end) 437 break; 438 439 hash = hugetlb_fault_mutex_hash(h, current->mm, 440 &pseudo_vma, 441 mapping, next, 0); 442 mutex_lock(&hugetlb_fault_mutex_table[hash]); 443 444 /* 445 * If page is mapped, it was faulted in after being 446 * unmapped in caller. Unmap (again) now after taking 447 * the fault mutex. The mutex will prevent faults 448 * until we finish removing the page. 449 * 450 * This race can only happen in the hole punch case. 451 * Getting here in a truncate operation is a bug. 452 */ 453 if (unlikely(page_mapped(page))) { 454 BUG_ON(truncate_op); 455 456 i_mmap_lock_write(mapping); 457 hugetlb_vmdelete_list(&mapping->i_mmap, 458 next * pages_per_huge_page(h), 459 (next + 1) * pages_per_huge_page(h)); 460 i_mmap_unlock_write(mapping); 461 } 462 463 lock_page(page); 464 /* 465 * We must free the huge page and remove from page 466 * cache (remove_huge_page) BEFORE removing the 467 * region/reserve map (hugetlb_unreserve_pages). In 468 * rare out of memory conditions, removal of the 469 * region/reserve map could fail. Correspondingly, 470 * the subpool and global reserve usage count can need 471 * to be adjusted. 472 */ 473 VM_BUG_ON(PagePrivate(page)); 474 remove_huge_page(page); 475 freed++; 476 if (!truncate_op) { 477 if (unlikely(hugetlb_unreserve_pages(inode, 478 next, next + 1, 1))) 479 hugetlb_fix_reserve_counts(inode); 480 } 481 482 unlock_page(page); 483 mutex_unlock(&hugetlb_fault_mutex_table[hash]); 484 } 485 ++next; 486 huge_pagevec_release(&pvec); 487 cond_resched(); 488 } 489 490 if (truncate_op) 491 (void)hugetlb_unreserve_pages(inode, start, LONG_MAX, freed); 492 } 493 494 static void hugetlbfs_evict_inode(struct inode *inode) 495 { 496 struct resv_map *resv_map; 497 498 remove_inode_hugepages(inode, 0, LLONG_MAX); 499 resv_map = (struct resv_map *)inode->i_mapping->private_data; 500 /* root inode doesn't have the resv_map, so we should check it */ 501 if (resv_map) 502 resv_map_release(&resv_map->refs); 503 clear_inode(inode); 504 } 505 506 static int hugetlb_vmtruncate(struct inode *inode, loff_t offset) 507 { 508 pgoff_t pgoff; 509 struct address_space *mapping = inode->i_mapping; 510 struct hstate *h = hstate_inode(inode); 511 512 BUG_ON(offset & ~huge_page_mask(h)); 513 pgoff = offset >> PAGE_SHIFT; 514 515 i_size_write(inode, offset); 516 i_mmap_lock_write(mapping); 517 if (!RB_EMPTY_ROOT(&mapping->i_mmap)) 518 hugetlb_vmdelete_list(&mapping->i_mmap, pgoff, 0); 519 i_mmap_unlock_write(mapping); 520 remove_inode_hugepages(inode, offset, LLONG_MAX); 521 return 0; 522 } 523 524 static long hugetlbfs_punch_hole(struct inode *inode, loff_t offset, loff_t len) 525 { 526 struct hstate *h = hstate_inode(inode); 527 loff_t hpage_size = huge_page_size(h); 528 loff_t hole_start, hole_end; 529 530 /* 531 * For hole punch round up the beginning offset of the hole and 532 * round down the end. 533 */ 534 hole_start = round_up(offset, hpage_size); 535 hole_end = round_down(offset + len, hpage_size); 536 537 if (hole_end > hole_start) { 538 struct address_space *mapping = inode->i_mapping; 539 540 inode_lock(inode); 541 i_mmap_lock_write(mapping); 542 if (!RB_EMPTY_ROOT(&mapping->i_mmap)) 543 hugetlb_vmdelete_list(&mapping->i_mmap, 544 hole_start >> PAGE_SHIFT, 545 hole_end >> PAGE_SHIFT); 546 i_mmap_unlock_write(mapping); 547 remove_inode_hugepages(inode, hole_start, hole_end); 548 inode_unlock(inode); 549 } 550 551 return 0; 552 } 553 554 static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset, 555 loff_t len) 556 { 557 struct inode *inode = file_inode(file); 558 struct address_space *mapping = inode->i_mapping; 559 struct hstate *h = hstate_inode(inode); 560 struct vm_area_struct pseudo_vma; 561 struct mm_struct *mm = current->mm; 562 loff_t hpage_size = huge_page_size(h); 563 unsigned long hpage_shift = huge_page_shift(h); 564 pgoff_t start, index, end; 565 int error; 566 u32 hash; 567 568 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) 569 return -EOPNOTSUPP; 570 571 if (mode & FALLOC_FL_PUNCH_HOLE) 572 return hugetlbfs_punch_hole(inode, offset, len); 573 574 /* 575 * Default preallocate case. 576 * For this range, start is rounded down and end is rounded up 577 * as well as being converted to page offsets. 578 */ 579 start = offset >> hpage_shift; 580 end = (offset + len + hpage_size - 1) >> hpage_shift; 581 582 inode_lock(inode); 583 584 /* We need to check rlimit even when FALLOC_FL_KEEP_SIZE */ 585 error = inode_newsize_ok(inode, offset + len); 586 if (error) 587 goto out; 588 589 /* 590 * Initialize a pseudo vma as this is required by the huge page 591 * allocation routines. If NUMA is configured, use page index 592 * as input to create an allocation policy. 593 */ 594 memset(&pseudo_vma, 0, sizeof(struct vm_area_struct)); 595 pseudo_vma.vm_flags = (VM_HUGETLB | VM_MAYSHARE | VM_SHARED); 596 pseudo_vma.vm_file = file; 597 598 for (index = start; index < end; index++) { 599 /* 600 * This is supposed to be the vaddr where the page is being 601 * faulted in, but we have no vaddr here. 602 */ 603 struct page *page; 604 unsigned long addr; 605 int avoid_reserve = 0; 606 607 cond_resched(); 608 609 /* 610 * fallocate(2) manpage permits EINTR; we may have been 611 * interrupted because we are using up too much memory. 612 */ 613 if (signal_pending(current)) { 614 error = -EINTR; 615 break; 616 } 617 618 /* Set numa allocation policy based on index */ 619 hugetlb_set_vma_policy(&pseudo_vma, inode, index); 620 621 /* addr is the offset within the file (zero based) */ 622 addr = index * hpage_size; 623 624 /* mutex taken here, fault path and hole punch */ 625 hash = hugetlb_fault_mutex_hash(h, mm, &pseudo_vma, mapping, 626 index, addr); 627 mutex_lock(&hugetlb_fault_mutex_table[hash]); 628 629 /* See if already present in mapping to avoid alloc/free */ 630 page = find_get_page(mapping, index); 631 if (page) { 632 put_page(page); 633 mutex_unlock(&hugetlb_fault_mutex_table[hash]); 634 hugetlb_drop_vma_policy(&pseudo_vma); 635 continue; 636 } 637 638 /* Allocate page and add to page cache */ 639 page = alloc_huge_page(&pseudo_vma, addr, avoid_reserve); 640 hugetlb_drop_vma_policy(&pseudo_vma); 641 if (IS_ERR(page)) { 642 mutex_unlock(&hugetlb_fault_mutex_table[hash]); 643 error = PTR_ERR(page); 644 goto out; 645 } 646 clear_huge_page(page, addr, pages_per_huge_page(h)); 647 __SetPageUptodate(page); 648 error = huge_add_to_page_cache(page, mapping, index); 649 if (unlikely(error)) { 650 put_page(page); 651 mutex_unlock(&hugetlb_fault_mutex_table[hash]); 652 goto out; 653 } 654 655 mutex_unlock(&hugetlb_fault_mutex_table[hash]); 656 657 /* 658 * page_put due to reference from alloc_huge_page() 659 * unlock_page because locked by add_to_page_cache() 660 */ 661 put_page(page); 662 unlock_page(page); 663 } 664 665 if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) 666 i_size_write(inode, offset + len); 667 inode->i_ctime = current_time(inode); 668 out: 669 inode_unlock(inode); 670 return error; 671 } 672 673 static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr) 674 { 675 struct inode *inode = d_inode(dentry); 676 struct hstate *h = hstate_inode(inode); 677 int error; 678 unsigned int ia_valid = attr->ia_valid; 679 680 BUG_ON(!inode); 681 682 error = setattr_prepare(dentry, attr); 683 if (error) 684 return error; 685 686 if (ia_valid & ATTR_SIZE) { 687 error = -EINVAL; 688 if (attr->ia_size & ~huge_page_mask(h)) 689 return -EINVAL; 690 error = hugetlb_vmtruncate(inode, attr->ia_size); 691 if (error) 692 return error; 693 } 694 695 setattr_copy(inode, attr); 696 mark_inode_dirty(inode); 697 return 0; 698 } 699 700 static struct inode *hugetlbfs_get_root(struct super_block *sb, 701 struct hugetlbfs_config *config) 702 { 703 struct inode *inode; 704 705 inode = new_inode(sb); 706 if (inode) { 707 inode->i_ino = get_next_ino(); 708 inode->i_mode = S_IFDIR | config->mode; 709 inode->i_uid = config->uid; 710 inode->i_gid = config->gid; 711 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); 712 inode->i_op = &hugetlbfs_dir_inode_operations; 713 inode->i_fop = &simple_dir_operations; 714 /* directory inodes start off with i_nlink == 2 (for "." entry) */ 715 inc_nlink(inode); 716 lockdep_annotate_inode_mutex_key(inode); 717 } 718 return inode; 719 } 720 721 /* 722 * Hugetlbfs is not reclaimable; therefore its i_mmap_rwsem will never 723 * be taken from reclaim -- unlike regular filesystems. This needs an 724 * annotation because huge_pmd_share() does an allocation under hugetlb's 725 * i_mmap_rwsem. 726 */ 727 static struct lock_class_key hugetlbfs_i_mmap_rwsem_key; 728 729 static struct inode *hugetlbfs_get_inode(struct super_block *sb, 730 struct inode *dir, 731 umode_t mode, dev_t dev) 732 { 733 struct inode *inode; 734 struct resv_map *resv_map; 735 736 resv_map = resv_map_alloc(); 737 if (!resv_map) 738 return NULL; 739 740 inode = new_inode(sb); 741 if (inode) { 742 inode->i_ino = get_next_ino(); 743 inode_init_owner(inode, dir, mode); 744 lockdep_set_class(&inode->i_mapping->i_mmap_rwsem, 745 &hugetlbfs_i_mmap_rwsem_key); 746 inode->i_mapping->a_ops = &hugetlbfs_aops; 747 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); 748 inode->i_mapping->private_data = resv_map; 749 switch (mode & S_IFMT) { 750 default: 751 init_special_inode(inode, mode, dev); 752 break; 753 case S_IFREG: 754 inode->i_op = &hugetlbfs_inode_operations; 755 inode->i_fop = &hugetlbfs_file_operations; 756 break; 757 case S_IFDIR: 758 inode->i_op = &hugetlbfs_dir_inode_operations; 759 inode->i_fop = &simple_dir_operations; 760 761 /* directory inodes start off with i_nlink == 2 (for "." entry) */ 762 inc_nlink(inode); 763 break; 764 case S_IFLNK: 765 inode->i_op = &page_symlink_inode_operations; 766 inode_nohighmem(inode); 767 break; 768 } 769 lockdep_annotate_inode_mutex_key(inode); 770 } else 771 kref_put(&resv_map->refs, resv_map_release); 772 773 return inode; 774 } 775 776 /* 777 * File creation. Allocate an inode, and we're done.. 778 */ 779 static int hugetlbfs_mknod(struct inode *dir, 780 struct dentry *dentry, umode_t mode, dev_t dev) 781 { 782 struct inode *inode; 783 int error = -ENOSPC; 784 785 inode = hugetlbfs_get_inode(dir->i_sb, dir, mode, dev); 786 if (inode) { 787 dir->i_ctime = dir->i_mtime = current_time(dir); 788 d_instantiate(dentry, inode); 789 dget(dentry); /* Extra count - pin the dentry in core */ 790 error = 0; 791 } 792 return error; 793 } 794 795 static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 796 { 797 int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0); 798 if (!retval) 799 inc_nlink(dir); 800 return retval; 801 } 802 803 static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl) 804 { 805 return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0); 806 } 807 808 static int hugetlbfs_symlink(struct inode *dir, 809 struct dentry *dentry, const char *symname) 810 { 811 struct inode *inode; 812 int error = -ENOSPC; 813 814 inode = hugetlbfs_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0); 815 if (inode) { 816 int l = strlen(symname)+1; 817 error = page_symlink(inode, symname, l); 818 if (!error) { 819 d_instantiate(dentry, inode); 820 dget(dentry); 821 } else 822 iput(inode); 823 } 824 dir->i_ctime = dir->i_mtime = current_time(dir); 825 826 return error; 827 } 828 829 /* 830 * mark the head page dirty 831 */ 832 static int hugetlbfs_set_page_dirty(struct page *page) 833 { 834 struct page *head = compound_head(page); 835 836 SetPageDirty(head); 837 return 0; 838 } 839 840 static int hugetlbfs_migrate_page(struct address_space *mapping, 841 struct page *newpage, struct page *page, 842 enum migrate_mode mode) 843 { 844 int rc; 845 846 rc = migrate_huge_page_move_mapping(mapping, newpage, page); 847 if (rc != MIGRATEPAGE_SUCCESS) 848 return rc; 849 migrate_page_copy(newpage, page); 850 851 return MIGRATEPAGE_SUCCESS; 852 } 853 854 static int hugetlbfs_error_remove_page(struct address_space *mapping, 855 struct page *page) 856 { 857 struct inode *inode = mapping->host; 858 859 remove_huge_page(page); 860 hugetlb_fix_reserve_counts(inode); 861 return 0; 862 } 863 864 /* 865 * Display the mount options in /proc/mounts. 866 */ 867 static int hugetlbfs_show_options(struct seq_file *m, struct dentry *root) 868 { 869 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(root->d_sb); 870 struct hugepage_subpool *spool = sbinfo->spool; 871 unsigned long hpage_size = huge_page_size(sbinfo->hstate); 872 unsigned hpage_shift = huge_page_shift(sbinfo->hstate); 873 char mod; 874 875 if (!uid_eq(sbinfo->uid, GLOBAL_ROOT_UID)) 876 seq_printf(m, ",uid=%u", 877 from_kuid_munged(&init_user_ns, sbinfo->uid)); 878 if (!gid_eq(sbinfo->gid, GLOBAL_ROOT_GID)) 879 seq_printf(m, ",gid=%u", 880 from_kgid_munged(&init_user_ns, sbinfo->gid)); 881 if (sbinfo->mode != 0755) 882 seq_printf(m, ",mode=%o", sbinfo->mode); 883 if (sbinfo->max_inodes != -1) 884 seq_printf(m, ",nr_inodes=%lu", sbinfo->max_inodes); 885 886 hpage_size /= 1024; 887 mod = 'K'; 888 if (hpage_size >= 1024) { 889 hpage_size /= 1024; 890 mod = 'M'; 891 } 892 seq_printf(m, ",pagesize=%lu%c", hpage_size, mod); 893 if (spool) { 894 if (spool->max_hpages != -1) 895 seq_printf(m, ",size=%llu", 896 (unsigned long long)spool->max_hpages << hpage_shift); 897 if (spool->min_hpages != -1) 898 seq_printf(m, ",min_size=%llu", 899 (unsigned long long)spool->min_hpages << hpage_shift); 900 } 901 return 0; 902 } 903 904 static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf) 905 { 906 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb); 907 struct hstate *h = hstate_inode(d_inode(dentry)); 908 909 buf->f_type = HUGETLBFS_MAGIC; 910 buf->f_bsize = huge_page_size(h); 911 if (sbinfo) { 912 spin_lock(&sbinfo->stat_lock); 913 /* If no limits set, just report 0 for max/free/used 914 * blocks, like simple_statfs() */ 915 if (sbinfo->spool) { 916 long free_pages; 917 918 spin_lock(&sbinfo->spool->lock); 919 buf->f_blocks = sbinfo->spool->max_hpages; 920 free_pages = sbinfo->spool->max_hpages 921 - sbinfo->spool->used_hpages; 922 buf->f_bavail = buf->f_bfree = free_pages; 923 spin_unlock(&sbinfo->spool->lock); 924 buf->f_files = sbinfo->max_inodes; 925 buf->f_ffree = sbinfo->free_inodes; 926 } 927 spin_unlock(&sbinfo->stat_lock); 928 } 929 buf->f_namelen = NAME_MAX; 930 return 0; 931 } 932 933 static void hugetlbfs_put_super(struct super_block *sb) 934 { 935 struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb); 936 937 if (sbi) { 938 sb->s_fs_info = NULL; 939 940 if (sbi->spool) 941 hugepage_put_subpool(sbi->spool); 942 943 kfree(sbi); 944 } 945 } 946 947 static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo) 948 { 949 if (sbinfo->free_inodes >= 0) { 950 spin_lock(&sbinfo->stat_lock); 951 if (unlikely(!sbinfo->free_inodes)) { 952 spin_unlock(&sbinfo->stat_lock); 953 return 0; 954 } 955 sbinfo->free_inodes--; 956 spin_unlock(&sbinfo->stat_lock); 957 } 958 959 return 1; 960 } 961 962 static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo) 963 { 964 if (sbinfo->free_inodes >= 0) { 965 spin_lock(&sbinfo->stat_lock); 966 sbinfo->free_inodes++; 967 spin_unlock(&sbinfo->stat_lock); 968 } 969 } 970 971 972 static struct kmem_cache *hugetlbfs_inode_cachep; 973 974 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb) 975 { 976 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); 977 struct hugetlbfs_inode_info *p; 978 979 if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo))) 980 return NULL; 981 p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL); 982 if (unlikely(!p)) { 983 hugetlbfs_inc_free_inodes(sbinfo); 984 return NULL; 985 } 986 987 /* 988 * Any time after allocation, hugetlbfs_destroy_inode can be called 989 * for the inode. mpol_free_shared_policy is unconditionally called 990 * as part of hugetlbfs_destroy_inode. So, initialize policy here 991 * in case of a quick call to destroy. 992 * 993 * Note that the policy is initialized even if we are creating a 994 * private inode. This simplifies hugetlbfs_destroy_inode. 995 */ 996 mpol_shared_policy_init(&p->policy, NULL); 997 998 return &p->vfs_inode; 999 } 1000 1001 static void hugetlbfs_i_callback(struct rcu_head *head) 1002 { 1003 struct inode *inode = container_of(head, struct inode, i_rcu); 1004 kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode)); 1005 } 1006 1007 static void hugetlbfs_destroy_inode(struct inode *inode) 1008 { 1009 hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb)); 1010 mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy); 1011 call_rcu(&inode->i_rcu, hugetlbfs_i_callback); 1012 } 1013 1014 static const struct address_space_operations hugetlbfs_aops = { 1015 .write_begin = hugetlbfs_write_begin, 1016 .write_end = hugetlbfs_write_end, 1017 .set_page_dirty = hugetlbfs_set_page_dirty, 1018 .migratepage = hugetlbfs_migrate_page, 1019 .error_remove_page = hugetlbfs_error_remove_page, 1020 }; 1021 1022 1023 static void init_once(void *foo) 1024 { 1025 struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo; 1026 1027 inode_init_once(&ei->vfs_inode); 1028 } 1029 1030 const struct file_operations hugetlbfs_file_operations = { 1031 .read_iter = hugetlbfs_read_iter, 1032 .mmap = hugetlbfs_file_mmap, 1033 .fsync = noop_fsync, 1034 .get_unmapped_area = hugetlb_get_unmapped_area, 1035 .llseek = default_llseek, 1036 .fallocate = hugetlbfs_fallocate, 1037 }; 1038 1039 static const struct inode_operations hugetlbfs_dir_inode_operations = { 1040 .create = hugetlbfs_create, 1041 .lookup = simple_lookup, 1042 .link = simple_link, 1043 .unlink = simple_unlink, 1044 .symlink = hugetlbfs_symlink, 1045 .mkdir = hugetlbfs_mkdir, 1046 .rmdir = simple_rmdir, 1047 .mknod = hugetlbfs_mknod, 1048 .rename = simple_rename, 1049 .setattr = hugetlbfs_setattr, 1050 }; 1051 1052 static const struct inode_operations hugetlbfs_inode_operations = { 1053 .setattr = hugetlbfs_setattr, 1054 }; 1055 1056 static const struct super_operations hugetlbfs_ops = { 1057 .alloc_inode = hugetlbfs_alloc_inode, 1058 .destroy_inode = hugetlbfs_destroy_inode, 1059 .evict_inode = hugetlbfs_evict_inode, 1060 .statfs = hugetlbfs_statfs, 1061 .put_super = hugetlbfs_put_super, 1062 .show_options = hugetlbfs_show_options, 1063 }; 1064 1065 enum hugetlbfs_size_type { NO_SIZE, SIZE_STD, SIZE_PERCENT }; 1066 1067 /* 1068 * Convert size option passed from command line to number of huge pages 1069 * in the pool specified by hstate. Size option could be in bytes 1070 * (val_type == SIZE_STD) or percentage of the pool (val_type == SIZE_PERCENT). 1071 */ 1072 static long 1073 hugetlbfs_size_to_hpages(struct hstate *h, unsigned long long size_opt, 1074 enum hugetlbfs_size_type val_type) 1075 { 1076 if (val_type == NO_SIZE) 1077 return -1; 1078 1079 if (val_type == SIZE_PERCENT) { 1080 size_opt <<= huge_page_shift(h); 1081 size_opt *= h->max_huge_pages; 1082 do_div(size_opt, 100); 1083 } 1084 1085 size_opt >>= huge_page_shift(h); 1086 return size_opt; 1087 } 1088 1089 static int 1090 hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig) 1091 { 1092 char *p, *rest; 1093 substring_t args[MAX_OPT_ARGS]; 1094 int option; 1095 unsigned long long max_size_opt = 0, min_size_opt = 0; 1096 enum hugetlbfs_size_type max_val_type = NO_SIZE, min_val_type = NO_SIZE; 1097 1098 if (!options) 1099 return 0; 1100 1101 while ((p = strsep(&options, ",")) != NULL) { 1102 int token; 1103 if (!*p) 1104 continue; 1105 1106 token = match_token(p, tokens, args); 1107 switch (token) { 1108 case Opt_uid: 1109 if (match_int(&args[0], &option)) 1110 goto bad_val; 1111 pconfig->uid = make_kuid(current_user_ns(), option); 1112 if (!uid_valid(pconfig->uid)) 1113 goto bad_val; 1114 break; 1115 1116 case Opt_gid: 1117 if (match_int(&args[0], &option)) 1118 goto bad_val; 1119 pconfig->gid = make_kgid(current_user_ns(), option); 1120 if (!gid_valid(pconfig->gid)) 1121 goto bad_val; 1122 break; 1123 1124 case Opt_mode: 1125 if (match_octal(&args[0], &option)) 1126 goto bad_val; 1127 pconfig->mode = option & 01777U; 1128 break; 1129 1130 case Opt_size: { 1131 /* memparse() will accept a K/M/G without a digit */ 1132 if (!isdigit(*args[0].from)) 1133 goto bad_val; 1134 max_size_opt = memparse(args[0].from, &rest); 1135 max_val_type = SIZE_STD; 1136 if (*rest == '%') 1137 max_val_type = SIZE_PERCENT; 1138 break; 1139 } 1140 1141 case Opt_nr_inodes: 1142 /* memparse() will accept a K/M/G without a digit */ 1143 if (!isdigit(*args[0].from)) 1144 goto bad_val; 1145 pconfig->nr_inodes = memparse(args[0].from, &rest); 1146 break; 1147 1148 case Opt_pagesize: { 1149 unsigned long ps; 1150 ps = memparse(args[0].from, &rest); 1151 pconfig->hstate = size_to_hstate(ps); 1152 if (!pconfig->hstate) { 1153 pr_err("Unsupported page size %lu MB\n", 1154 ps >> 20); 1155 return -EINVAL; 1156 } 1157 break; 1158 } 1159 1160 case Opt_min_size: { 1161 /* memparse() will accept a K/M/G without a digit */ 1162 if (!isdigit(*args[0].from)) 1163 goto bad_val; 1164 min_size_opt = memparse(args[0].from, &rest); 1165 min_val_type = SIZE_STD; 1166 if (*rest == '%') 1167 min_val_type = SIZE_PERCENT; 1168 break; 1169 } 1170 1171 default: 1172 pr_err("Bad mount option: \"%s\"\n", p); 1173 return -EINVAL; 1174 break; 1175 } 1176 } 1177 1178 /* 1179 * Use huge page pool size (in hstate) to convert the size 1180 * options to number of huge pages. If NO_SIZE, -1 is returned. 1181 */ 1182 pconfig->max_hpages = hugetlbfs_size_to_hpages(pconfig->hstate, 1183 max_size_opt, max_val_type); 1184 pconfig->min_hpages = hugetlbfs_size_to_hpages(pconfig->hstate, 1185 min_size_opt, min_val_type); 1186 1187 /* 1188 * If max_size was specified, then min_size must be smaller 1189 */ 1190 if (max_val_type > NO_SIZE && 1191 pconfig->min_hpages > pconfig->max_hpages) { 1192 pr_err("minimum size can not be greater than maximum size\n"); 1193 return -EINVAL; 1194 } 1195 1196 return 0; 1197 1198 bad_val: 1199 pr_err("Bad value '%s' for mount option '%s'\n", args[0].from, p); 1200 return -EINVAL; 1201 } 1202 1203 static int 1204 hugetlbfs_fill_super(struct super_block *sb, void *data, int silent) 1205 { 1206 int ret; 1207 struct hugetlbfs_config config; 1208 struct hugetlbfs_sb_info *sbinfo; 1209 1210 config.max_hpages = -1; /* No limit on size by default */ 1211 config.nr_inodes = -1; /* No limit on number of inodes by default */ 1212 config.uid = current_fsuid(); 1213 config.gid = current_fsgid(); 1214 config.mode = 0755; 1215 config.hstate = &default_hstate; 1216 config.min_hpages = -1; /* No default minimum size */ 1217 ret = hugetlbfs_parse_options(data, &config); 1218 if (ret) 1219 return ret; 1220 1221 sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL); 1222 if (!sbinfo) 1223 return -ENOMEM; 1224 sb->s_fs_info = sbinfo; 1225 sbinfo->hstate = config.hstate; 1226 spin_lock_init(&sbinfo->stat_lock); 1227 sbinfo->max_inodes = config.nr_inodes; 1228 sbinfo->free_inodes = config.nr_inodes; 1229 sbinfo->spool = NULL; 1230 sbinfo->uid = config.uid; 1231 sbinfo->gid = config.gid; 1232 sbinfo->mode = config.mode; 1233 1234 /* 1235 * Allocate and initialize subpool if maximum or minimum size is 1236 * specified. Any needed reservations (for minimim size) are taken 1237 * taken when the subpool is created. 1238 */ 1239 if (config.max_hpages != -1 || config.min_hpages != -1) { 1240 sbinfo->spool = hugepage_new_subpool(config.hstate, 1241 config.max_hpages, 1242 config.min_hpages); 1243 if (!sbinfo->spool) 1244 goto out_free; 1245 } 1246 sb->s_maxbytes = MAX_LFS_FILESIZE; 1247 sb->s_blocksize = huge_page_size(config.hstate); 1248 sb->s_blocksize_bits = huge_page_shift(config.hstate); 1249 sb->s_magic = HUGETLBFS_MAGIC; 1250 sb->s_op = &hugetlbfs_ops; 1251 sb->s_time_gran = 1; 1252 sb->s_root = d_make_root(hugetlbfs_get_root(sb, &config)); 1253 if (!sb->s_root) 1254 goto out_free; 1255 return 0; 1256 out_free: 1257 kfree(sbinfo->spool); 1258 kfree(sbinfo); 1259 return -ENOMEM; 1260 } 1261 1262 static struct dentry *hugetlbfs_mount(struct file_system_type *fs_type, 1263 int flags, const char *dev_name, void *data) 1264 { 1265 return mount_nodev(fs_type, flags, data, hugetlbfs_fill_super); 1266 } 1267 1268 static struct file_system_type hugetlbfs_fs_type = { 1269 .name = "hugetlbfs", 1270 .mount = hugetlbfs_mount, 1271 .kill_sb = kill_litter_super, 1272 }; 1273 1274 static struct vfsmount *hugetlbfs_vfsmount[HUGE_MAX_HSTATE]; 1275 1276 static int can_do_hugetlb_shm(void) 1277 { 1278 kgid_t shm_group; 1279 shm_group = make_kgid(&init_user_ns, sysctl_hugetlb_shm_group); 1280 return capable(CAP_IPC_LOCK) || in_group_p(shm_group); 1281 } 1282 1283 static int get_hstate_idx(int page_size_log) 1284 { 1285 struct hstate *h = hstate_sizelog(page_size_log); 1286 1287 if (!h) 1288 return -1; 1289 return h - hstates; 1290 } 1291 1292 static const struct dentry_operations anon_ops = { 1293 .d_dname = simple_dname 1294 }; 1295 1296 /* 1297 * Note that size should be aligned to proper hugepage size in caller side, 1298 * otherwise hugetlb_reserve_pages reserves one less hugepages than intended. 1299 */ 1300 struct file *hugetlb_file_setup(const char *name, size_t size, 1301 vm_flags_t acctflag, struct user_struct **user, 1302 int creat_flags, int page_size_log) 1303 { 1304 struct file *file = ERR_PTR(-ENOMEM); 1305 struct inode *inode; 1306 struct path path; 1307 struct super_block *sb; 1308 struct qstr quick_string; 1309 int hstate_idx; 1310 1311 hstate_idx = get_hstate_idx(page_size_log); 1312 if (hstate_idx < 0) 1313 return ERR_PTR(-ENODEV); 1314 1315 *user = NULL; 1316 if (!hugetlbfs_vfsmount[hstate_idx]) 1317 return ERR_PTR(-ENOENT); 1318 1319 if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) { 1320 *user = current_user(); 1321 if (user_shm_lock(size, *user)) { 1322 task_lock(current); 1323 pr_warn_once("%s (%d): Using mlock ulimits for SHM_HUGETLB is deprecated\n", 1324 current->comm, current->pid); 1325 task_unlock(current); 1326 } else { 1327 *user = NULL; 1328 return ERR_PTR(-EPERM); 1329 } 1330 } 1331 1332 sb = hugetlbfs_vfsmount[hstate_idx]->mnt_sb; 1333 quick_string.name = name; 1334 quick_string.len = strlen(quick_string.name); 1335 quick_string.hash = 0; 1336 path.dentry = d_alloc_pseudo(sb, &quick_string); 1337 if (!path.dentry) 1338 goto out_shm_unlock; 1339 1340 d_set_d_op(path.dentry, &anon_ops); 1341 path.mnt = mntget(hugetlbfs_vfsmount[hstate_idx]); 1342 file = ERR_PTR(-ENOSPC); 1343 inode = hugetlbfs_get_inode(sb, NULL, S_IFREG | S_IRWXUGO, 0); 1344 if (!inode) 1345 goto out_dentry; 1346 if (creat_flags == HUGETLB_SHMFS_INODE) 1347 inode->i_flags |= S_PRIVATE; 1348 1349 file = ERR_PTR(-ENOMEM); 1350 if (hugetlb_reserve_pages(inode, 0, 1351 size >> huge_page_shift(hstate_inode(inode)), NULL, 1352 acctflag)) 1353 goto out_inode; 1354 1355 d_instantiate(path.dentry, inode); 1356 inode->i_size = size; 1357 clear_nlink(inode); 1358 1359 file = alloc_file(&path, FMODE_WRITE | FMODE_READ, 1360 &hugetlbfs_file_operations); 1361 if (IS_ERR(file)) 1362 goto out_dentry; /* inode is already attached */ 1363 1364 return file; 1365 1366 out_inode: 1367 iput(inode); 1368 out_dentry: 1369 path_put(&path); 1370 out_shm_unlock: 1371 if (*user) { 1372 user_shm_unlock(size, *user); 1373 *user = NULL; 1374 } 1375 return file; 1376 } 1377 1378 static int __init init_hugetlbfs_fs(void) 1379 { 1380 struct hstate *h; 1381 int error; 1382 int i; 1383 1384 if (!hugepages_supported()) { 1385 pr_info("disabling because there are no supported hugepage sizes\n"); 1386 return -ENOTSUPP; 1387 } 1388 1389 error = -ENOMEM; 1390 hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache", 1391 sizeof(struct hugetlbfs_inode_info), 1392 0, SLAB_ACCOUNT, init_once); 1393 if (hugetlbfs_inode_cachep == NULL) 1394 goto out2; 1395 1396 error = register_filesystem(&hugetlbfs_fs_type); 1397 if (error) 1398 goto out; 1399 1400 i = 0; 1401 for_each_hstate(h) { 1402 char buf[50]; 1403 unsigned ps_kb = 1U << (h->order + PAGE_SHIFT - 10); 1404 1405 snprintf(buf, sizeof(buf), "pagesize=%uK", ps_kb); 1406 hugetlbfs_vfsmount[i] = kern_mount_data(&hugetlbfs_fs_type, 1407 buf); 1408 1409 if (IS_ERR(hugetlbfs_vfsmount[i])) { 1410 pr_err("Cannot mount internal hugetlbfs for " 1411 "page size %uK", ps_kb); 1412 error = PTR_ERR(hugetlbfs_vfsmount[i]); 1413 hugetlbfs_vfsmount[i] = NULL; 1414 } 1415 i++; 1416 } 1417 /* Non default hstates are optional */ 1418 if (!IS_ERR_OR_NULL(hugetlbfs_vfsmount[default_hstate_idx])) 1419 return 0; 1420 1421 out: 1422 kmem_cache_destroy(hugetlbfs_inode_cachep); 1423 out2: 1424 return error; 1425 } 1426 fs_initcall(init_hugetlbfs_fs) 1427