1 /* 2 * hugetlbpage-backed filesystem. Based on ramfs. 3 * 4 * William Irwin, 2002 5 * 6 * Copyright (C) 2002 Linus Torvalds. 7 */ 8 9 #include <linux/module.h> 10 #include <linux/thread_info.h> 11 #include <asm/current.h> 12 #include <linux/sched.h> /* remove ASAP */ 13 #include <linux/fs.h> 14 #include <linux/mount.h> 15 #include <linux/file.h> 16 #include <linux/kernel.h> 17 #include <linux/writeback.h> 18 #include <linux/pagemap.h> 19 #include <linux/highmem.h> 20 #include <linux/init.h> 21 #include <linux/string.h> 22 #include <linux/capability.h> 23 #include <linux/ctype.h> 24 #include <linux/backing-dev.h> 25 #include <linux/hugetlb.h> 26 #include <linux/pagevec.h> 27 #include <linux/parser.h> 28 #include <linux/mman.h> 29 #include <linux/slab.h> 30 #include <linux/dnotify.h> 31 #include <linux/statfs.h> 32 #include <linux/security.h> 33 #include <linux/magic.h> 34 #include <linux/migrate.h> 35 36 #include <asm/uaccess.h> 37 38 static const struct super_operations hugetlbfs_ops; 39 static const struct address_space_operations hugetlbfs_aops; 40 const struct file_operations hugetlbfs_file_operations; 41 static const struct inode_operations hugetlbfs_dir_inode_operations; 42 static const struct inode_operations hugetlbfs_inode_operations; 43 44 static struct backing_dev_info hugetlbfs_backing_dev_info = { 45 .name = "hugetlbfs", 46 .ra_pages = 0, /* No readahead */ 47 .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK, 48 }; 49 50 int sysctl_hugetlb_shm_group; 51 52 enum { 53 Opt_size, Opt_nr_inodes, 54 Opt_mode, Opt_uid, Opt_gid, 55 Opt_pagesize, 56 Opt_err, 57 }; 58 59 static const match_table_t tokens = { 60 {Opt_size, "size=%s"}, 61 {Opt_nr_inodes, "nr_inodes=%s"}, 62 {Opt_mode, "mode=%o"}, 63 {Opt_uid, "uid=%u"}, 64 {Opt_gid, "gid=%u"}, 65 {Opt_pagesize, "pagesize=%s"}, 66 {Opt_err, NULL}, 67 }; 68 69 static void huge_pagevec_release(struct pagevec *pvec) 70 { 71 int i; 72 73 for (i = 0; i < pagevec_count(pvec); ++i) 74 put_page(pvec->pages[i]); 75 76 pagevec_reinit(pvec); 77 } 78 79 static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma) 80 { 81 struct inode *inode = file->f_path.dentry->d_inode; 82 loff_t len, vma_len; 83 int ret; 84 struct hstate *h = hstate_file(file); 85 86 /* 87 * vma address alignment (but not the pgoff alignment) has 88 * already been checked by prepare_hugepage_range. If you add 89 * any error returns here, do so after setting VM_HUGETLB, so 90 * is_vm_hugetlb_page tests below unmap_region go the right 91 * way when do_mmap_pgoff unwinds (may be important on powerpc 92 * and ia64). 93 */ 94 vma->vm_flags |= VM_HUGETLB | VM_RESERVED; 95 vma->vm_ops = &hugetlb_vm_ops; 96 97 if (vma->vm_pgoff & ~(huge_page_mask(h) >> PAGE_SHIFT)) 98 return -EINVAL; 99 100 vma_len = (loff_t)(vma->vm_end - vma->vm_start); 101 102 mutex_lock(&inode->i_mutex); 103 file_accessed(file); 104 105 ret = -ENOMEM; 106 len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); 107 108 if (hugetlb_reserve_pages(inode, 109 vma->vm_pgoff >> huge_page_order(h), 110 len >> huge_page_shift(h), vma, 111 vma->vm_flags)) 112 goto out; 113 114 ret = 0; 115 hugetlb_prefault_arch_hook(vma->vm_mm); 116 if (vma->vm_flags & VM_WRITE && inode->i_size < len) 117 inode->i_size = len; 118 out: 119 mutex_unlock(&inode->i_mutex); 120 121 return ret; 122 } 123 124 /* 125 * Called under down_write(mmap_sem). 126 */ 127 128 #ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA 129 static unsigned long 130 hugetlb_get_unmapped_area(struct file *file, unsigned long addr, 131 unsigned long len, unsigned long pgoff, unsigned long flags) 132 { 133 struct mm_struct *mm = current->mm; 134 struct vm_area_struct *vma; 135 unsigned long start_addr; 136 struct hstate *h = hstate_file(file); 137 138 if (len & ~huge_page_mask(h)) 139 return -EINVAL; 140 if (len > TASK_SIZE) 141 return -ENOMEM; 142 143 if (flags & MAP_FIXED) { 144 if (prepare_hugepage_range(file, addr, len)) 145 return -EINVAL; 146 return addr; 147 } 148 149 if (addr) { 150 addr = ALIGN(addr, huge_page_size(h)); 151 vma = find_vma(mm, addr); 152 if (TASK_SIZE - len >= addr && 153 (!vma || addr + len <= vma->vm_start)) 154 return addr; 155 } 156 157 start_addr = mm->free_area_cache; 158 159 if (len <= mm->cached_hole_size) 160 start_addr = TASK_UNMAPPED_BASE; 161 162 full_search: 163 addr = ALIGN(start_addr, huge_page_size(h)); 164 165 for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { 166 /* At this point: (!vma || addr < vma->vm_end). */ 167 if (TASK_SIZE - len < addr) { 168 /* 169 * Start a new search - just in case we missed 170 * some holes. 171 */ 172 if (start_addr != TASK_UNMAPPED_BASE) { 173 start_addr = TASK_UNMAPPED_BASE; 174 goto full_search; 175 } 176 return -ENOMEM; 177 } 178 179 if (!vma || addr + len <= vma->vm_start) 180 return addr; 181 addr = ALIGN(vma->vm_end, huge_page_size(h)); 182 } 183 } 184 #endif 185 186 static int 187 hugetlbfs_read_actor(struct page *page, unsigned long offset, 188 char __user *buf, unsigned long count, 189 unsigned long size) 190 { 191 char *kaddr; 192 unsigned long left, copied = 0; 193 int i, chunksize; 194 195 if (size > count) 196 size = count; 197 198 /* Find which 4k chunk and offset with in that chunk */ 199 i = offset >> PAGE_CACHE_SHIFT; 200 offset = offset & ~PAGE_CACHE_MASK; 201 202 while (size) { 203 chunksize = PAGE_CACHE_SIZE; 204 if (offset) 205 chunksize -= offset; 206 if (chunksize > size) 207 chunksize = size; 208 kaddr = kmap(&page[i]); 209 left = __copy_to_user(buf, kaddr + offset, chunksize); 210 kunmap(&page[i]); 211 if (left) { 212 copied += (chunksize - left); 213 break; 214 } 215 offset = 0; 216 size -= chunksize; 217 buf += chunksize; 218 copied += chunksize; 219 i++; 220 } 221 return copied ? copied : -EFAULT; 222 } 223 224 /* 225 * Support for read() - Find the page attached to f_mapping and copy out the 226 * data. Its *very* similar to do_generic_mapping_read(), we can't use that 227 * since it has PAGE_CACHE_SIZE assumptions. 228 */ 229 static ssize_t hugetlbfs_read(struct file *filp, char __user *buf, 230 size_t len, loff_t *ppos) 231 { 232 struct hstate *h = hstate_file(filp); 233 struct address_space *mapping = filp->f_mapping; 234 struct inode *inode = mapping->host; 235 unsigned long index = *ppos >> huge_page_shift(h); 236 unsigned long offset = *ppos & ~huge_page_mask(h); 237 unsigned long end_index; 238 loff_t isize; 239 ssize_t retval = 0; 240 241 mutex_lock(&inode->i_mutex); 242 243 /* validate length */ 244 if (len == 0) 245 goto out; 246 247 isize = i_size_read(inode); 248 if (!isize) 249 goto out; 250 251 end_index = (isize - 1) >> huge_page_shift(h); 252 for (;;) { 253 struct page *page; 254 unsigned long nr, ret; 255 int ra; 256 257 /* nr is the maximum number of bytes to copy from this page */ 258 nr = huge_page_size(h); 259 if (index >= end_index) { 260 if (index > end_index) 261 goto out; 262 nr = ((isize - 1) & ~huge_page_mask(h)) + 1; 263 if (nr <= offset) { 264 goto out; 265 } 266 } 267 nr = nr - offset; 268 269 /* Find the page */ 270 page = find_get_page(mapping, index); 271 if (unlikely(page == NULL)) { 272 /* 273 * We have a HOLE, zero out the user-buffer for the 274 * length of the hole or request. 275 */ 276 ret = len < nr ? len : nr; 277 if (clear_user(buf, ret)) 278 ra = -EFAULT; 279 else 280 ra = 0; 281 } else { 282 /* 283 * We have the page, copy it to user space buffer. 284 */ 285 ra = hugetlbfs_read_actor(page, offset, buf, len, nr); 286 ret = ra; 287 } 288 if (ra < 0) { 289 if (retval == 0) 290 retval = ra; 291 if (page) 292 page_cache_release(page); 293 goto out; 294 } 295 296 offset += ret; 297 retval += ret; 298 len -= ret; 299 index += offset >> huge_page_shift(h); 300 offset &= ~huge_page_mask(h); 301 302 if (page) 303 page_cache_release(page); 304 305 /* short read or no more work */ 306 if ((ret != nr) || (len == 0)) 307 break; 308 } 309 out: 310 *ppos = ((loff_t)index << huge_page_shift(h)) + offset; 311 mutex_unlock(&inode->i_mutex); 312 return retval; 313 } 314 315 static int hugetlbfs_write_begin(struct file *file, 316 struct address_space *mapping, 317 loff_t pos, unsigned len, unsigned flags, 318 struct page **pagep, void **fsdata) 319 { 320 return -EINVAL; 321 } 322 323 static int hugetlbfs_write_end(struct file *file, struct address_space *mapping, 324 loff_t pos, unsigned len, unsigned copied, 325 struct page *page, void *fsdata) 326 { 327 BUG(); 328 return -EINVAL; 329 } 330 331 static void truncate_huge_page(struct page *page) 332 { 333 cancel_dirty_page(page, /* No IO accounting for huge pages? */0); 334 ClearPageUptodate(page); 335 remove_from_page_cache(page); 336 put_page(page); 337 } 338 339 static void truncate_hugepages(struct inode *inode, loff_t lstart) 340 { 341 struct hstate *h = hstate_inode(inode); 342 struct address_space *mapping = &inode->i_data; 343 const pgoff_t start = lstart >> huge_page_shift(h); 344 struct pagevec pvec; 345 pgoff_t next; 346 int i, freed = 0; 347 348 pagevec_init(&pvec, 0); 349 next = start; 350 while (1) { 351 if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) { 352 if (next == start) 353 break; 354 next = start; 355 continue; 356 } 357 358 for (i = 0; i < pagevec_count(&pvec); ++i) { 359 struct page *page = pvec.pages[i]; 360 361 lock_page(page); 362 if (page->index > next) 363 next = page->index; 364 ++next; 365 truncate_huge_page(page); 366 unlock_page(page); 367 freed++; 368 } 369 huge_pagevec_release(&pvec); 370 } 371 BUG_ON(!lstart && mapping->nrpages); 372 hugetlb_unreserve_pages(inode, start, freed); 373 } 374 375 static void hugetlbfs_evict_inode(struct inode *inode) 376 { 377 truncate_hugepages(inode, 0); 378 end_writeback(inode); 379 } 380 381 static inline void 382 hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff) 383 { 384 struct vm_area_struct *vma; 385 struct prio_tree_iter iter; 386 387 vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) { 388 unsigned long v_offset; 389 390 /* 391 * Can the expression below overflow on 32-bit arches? 392 * No, because the prio_tree returns us only those vmas 393 * which overlap the truncated area starting at pgoff, 394 * and no vma on a 32-bit arch can span beyond the 4GB. 395 */ 396 if (vma->vm_pgoff < pgoff) 397 v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT; 398 else 399 v_offset = 0; 400 401 __unmap_hugepage_range(vma, 402 vma->vm_start + v_offset, vma->vm_end, NULL); 403 } 404 } 405 406 static int hugetlb_vmtruncate(struct inode *inode, loff_t offset) 407 { 408 pgoff_t pgoff; 409 struct address_space *mapping = inode->i_mapping; 410 struct hstate *h = hstate_inode(inode); 411 412 BUG_ON(offset & ~huge_page_mask(h)); 413 pgoff = offset >> PAGE_SHIFT; 414 415 i_size_write(inode, offset); 416 spin_lock(&mapping->i_mmap_lock); 417 if (!prio_tree_empty(&mapping->i_mmap)) 418 hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff); 419 spin_unlock(&mapping->i_mmap_lock); 420 truncate_hugepages(inode, offset); 421 return 0; 422 } 423 424 static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr) 425 { 426 struct inode *inode = dentry->d_inode; 427 struct hstate *h = hstate_inode(inode); 428 int error; 429 unsigned int ia_valid = attr->ia_valid; 430 431 BUG_ON(!inode); 432 433 error = inode_change_ok(inode, attr); 434 if (error) 435 return error; 436 437 if (ia_valid & ATTR_SIZE) { 438 error = -EINVAL; 439 if (attr->ia_size & ~huge_page_mask(h)) 440 return -EINVAL; 441 error = hugetlb_vmtruncate(inode, attr->ia_size); 442 if (error) 443 return error; 444 } 445 446 setattr_copy(inode, attr); 447 mark_inode_dirty(inode); 448 return 0; 449 } 450 451 static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid, 452 gid_t gid, int mode, dev_t dev) 453 { 454 struct inode *inode; 455 456 inode = new_inode(sb); 457 if (inode) { 458 struct hugetlbfs_inode_info *info; 459 inode->i_ino = get_next_ino(); 460 inode->i_mode = mode; 461 inode->i_uid = uid; 462 inode->i_gid = gid; 463 inode->i_mapping->a_ops = &hugetlbfs_aops; 464 inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info; 465 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; 466 INIT_LIST_HEAD(&inode->i_mapping->private_list); 467 info = HUGETLBFS_I(inode); 468 /* 469 * The policy is initialized here even if we are creating a 470 * private inode because initialization simply creates an 471 * an empty rb tree and calls spin_lock_init(), later when we 472 * call mpol_free_shared_policy() it will just return because 473 * the rb tree will still be empty. 474 */ 475 mpol_shared_policy_init(&info->policy, NULL); 476 switch (mode & S_IFMT) { 477 default: 478 init_special_inode(inode, mode, dev); 479 break; 480 case S_IFREG: 481 inode->i_op = &hugetlbfs_inode_operations; 482 inode->i_fop = &hugetlbfs_file_operations; 483 break; 484 case S_IFDIR: 485 inode->i_op = &hugetlbfs_dir_inode_operations; 486 inode->i_fop = &simple_dir_operations; 487 488 /* directory inodes start off with i_nlink == 2 (for "." entry) */ 489 inc_nlink(inode); 490 break; 491 case S_IFLNK: 492 inode->i_op = &page_symlink_inode_operations; 493 break; 494 } 495 } 496 return inode; 497 } 498 499 /* 500 * File creation. Allocate an inode, and we're done.. 501 */ 502 static int hugetlbfs_mknod(struct inode *dir, 503 struct dentry *dentry, int mode, dev_t dev) 504 { 505 struct inode *inode; 506 int error = -ENOSPC; 507 gid_t gid; 508 509 if (dir->i_mode & S_ISGID) { 510 gid = dir->i_gid; 511 if (S_ISDIR(mode)) 512 mode |= S_ISGID; 513 } else { 514 gid = current_fsgid(); 515 } 516 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), gid, mode, dev); 517 if (inode) { 518 dir->i_ctime = dir->i_mtime = CURRENT_TIME; 519 d_instantiate(dentry, inode); 520 dget(dentry); /* Extra count - pin the dentry in core */ 521 error = 0; 522 } 523 return error; 524 } 525 526 static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) 527 { 528 int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0); 529 if (!retval) 530 inc_nlink(dir); 531 return retval; 532 } 533 534 static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) 535 { 536 return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0); 537 } 538 539 static int hugetlbfs_symlink(struct inode *dir, 540 struct dentry *dentry, const char *symname) 541 { 542 struct inode *inode; 543 int error = -ENOSPC; 544 gid_t gid; 545 546 if (dir->i_mode & S_ISGID) 547 gid = dir->i_gid; 548 else 549 gid = current_fsgid(); 550 551 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), 552 gid, S_IFLNK|S_IRWXUGO, 0); 553 if (inode) { 554 int l = strlen(symname)+1; 555 error = page_symlink(inode, symname, l); 556 if (!error) { 557 d_instantiate(dentry, inode); 558 dget(dentry); 559 } else 560 iput(inode); 561 } 562 dir->i_ctime = dir->i_mtime = CURRENT_TIME; 563 564 return error; 565 } 566 567 /* 568 * mark the head page dirty 569 */ 570 static int hugetlbfs_set_page_dirty(struct page *page) 571 { 572 struct page *head = compound_head(page); 573 574 SetPageDirty(head); 575 return 0; 576 } 577 578 static int hugetlbfs_migrate_page(struct address_space *mapping, 579 struct page *newpage, struct page *page) 580 { 581 int rc; 582 583 rc = migrate_huge_page_move_mapping(mapping, newpage, page); 584 if (rc) 585 return rc; 586 migrate_page_copy(newpage, page); 587 588 return 0; 589 } 590 591 static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf) 592 { 593 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb); 594 struct hstate *h = hstate_inode(dentry->d_inode); 595 596 buf->f_type = HUGETLBFS_MAGIC; 597 buf->f_bsize = huge_page_size(h); 598 if (sbinfo) { 599 spin_lock(&sbinfo->stat_lock); 600 /* If no limits set, just report 0 for max/free/used 601 * blocks, like simple_statfs() */ 602 if (sbinfo->max_blocks >= 0) { 603 buf->f_blocks = sbinfo->max_blocks; 604 buf->f_bavail = buf->f_bfree = sbinfo->free_blocks; 605 buf->f_files = sbinfo->max_inodes; 606 buf->f_ffree = sbinfo->free_inodes; 607 } 608 spin_unlock(&sbinfo->stat_lock); 609 } 610 buf->f_namelen = NAME_MAX; 611 return 0; 612 } 613 614 static void hugetlbfs_put_super(struct super_block *sb) 615 { 616 struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb); 617 618 if (sbi) { 619 sb->s_fs_info = NULL; 620 kfree(sbi); 621 } 622 } 623 624 static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo) 625 { 626 if (sbinfo->free_inodes >= 0) { 627 spin_lock(&sbinfo->stat_lock); 628 if (unlikely(!sbinfo->free_inodes)) { 629 spin_unlock(&sbinfo->stat_lock); 630 return 0; 631 } 632 sbinfo->free_inodes--; 633 spin_unlock(&sbinfo->stat_lock); 634 } 635 636 return 1; 637 } 638 639 static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo) 640 { 641 if (sbinfo->free_inodes >= 0) { 642 spin_lock(&sbinfo->stat_lock); 643 sbinfo->free_inodes++; 644 spin_unlock(&sbinfo->stat_lock); 645 } 646 } 647 648 649 static struct kmem_cache *hugetlbfs_inode_cachep; 650 651 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb) 652 { 653 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); 654 struct hugetlbfs_inode_info *p; 655 656 if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo))) 657 return NULL; 658 p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL); 659 if (unlikely(!p)) { 660 hugetlbfs_inc_free_inodes(sbinfo); 661 return NULL; 662 } 663 return &p->vfs_inode; 664 } 665 666 static void hugetlbfs_destroy_inode(struct inode *inode) 667 { 668 hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb)); 669 mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy); 670 kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode)); 671 } 672 673 static const struct address_space_operations hugetlbfs_aops = { 674 .write_begin = hugetlbfs_write_begin, 675 .write_end = hugetlbfs_write_end, 676 .set_page_dirty = hugetlbfs_set_page_dirty, 677 .migratepage = hugetlbfs_migrate_page, 678 }; 679 680 681 static void init_once(void *foo) 682 { 683 struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo; 684 685 inode_init_once(&ei->vfs_inode); 686 } 687 688 const struct file_operations hugetlbfs_file_operations = { 689 .read = hugetlbfs_read, 690 .mmap = hugetlbfs_file_mmap, 691 .fsync = noop_fsync, 692 .get_unmapped_area = hugetlb_get_unmapped_area, 693 .llseek = default_llseek, 694 }; 695 696 static const struct inode_operations hugetlbfs_dir_inode_operations = { 697 .create = hugetlbfs_create, 698 .lookup = simple_lookup, 699 .link = simple_link, 700 .unlink = simple_unlink, 701 .symlink = hugetlbfs_symlink, 702 .mkdir = hugetlbfs_mkdir, 703 .rmdir = simple_rmdir, 704 .mknod = hugetlbfs_mknod, 705 .rename = simple_rename, 706 .setattr = hugetlbfs_setattr, 707 }; 708 709 static const struct inode_operations hugetlbfs_inode_operations = { 710 .setattr = hugetlbfs_setattr, 711 }; 712 713 static const struct super_operations hugetlbfs_ops = { 714 .alloc_inode = hugetlbfs_alloc_inode, 715 .destroy_inode = hugetlbfs_destroy_inode, 716 .evict_inode = hugetlbfs_evict_inode, 717 .statfs = hugetlbfs_statfs, 718 .put_super = hugetlbfs_put_super, 719 .show_options = generic_show_options, 720 }; 721 722 static int 723 hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig) 724 { 725 char *p, *rest; 726 substring_t args[MAX_OPT_ARGS]; 727 int option; 728 unsigned long long size = 0; 729 enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = NO_SIZE; 730 731 if (!options) 732 return 0; 733 734 while ((p = strsep(&options, ",")) != NULL) { 735 int token; 736 if (!*p) 737 continue; 738 739 token = match_token(p, tokens, args); 740 switch (token) { 741 case Opt_uid: 742 if (match_int(&args[0], &option)) 743 goto bad_val; 744 pconfig->uid = option; 745 break; 746 747 case Opt_gid: 748 if (match_int(&args[0], &option)) 749 goto bad_val; 750 pconfig->gid = option; 751 break; 752 753 case Opt_mode: 754 if (match_octal(&args[0], &option)) 755 goto bad_val; 756 pconfig->mode = option & 01777U; 757 break; 758 759 case Opt_size: { 760 /* memparse() will accept a K/M/G without a digit */ 761 if (!isdigit(*args[0].from)) 762 goto bad_val; 763 size = memparse(args[0].from, &rest); 764 setsize = SIZE_STD; 765 if (*rest == '%') 766 setsize = SIZE_PERCENT; 767 break; 768 } 769 770 case Opt_nr_inodes: 771 /* memparse() will accept a K/M/G without a digit */ 772 if (!isdigit(*args[0].from)) 773 goto bad_val; 774 pconfig->nr_inodes = memparse(args[0].from, &rest); 775 break; 776 777 case Opt_pagesize: { 778 unsigned long ps; 779 ps = memparse(args[0].from, &rest); 780 pconfig->hstate = size_to_hstate(ps); 781 if (!pconfig->hstate) { 782 printk(KERN_ERR 783 "hugetlbfs: Unsupported page size %lu MB\n", 784 ps >> 20); 785 return -EINVAL; 786 } 787 break; 788 } 789 790 default: 791 printk(KERN_ERR "hugetlbfs: Bad mount option: \"%s\"\n", 792 p); 793 return -EINVAL; 794 break; 795 } 796 } 797 798 /* Do size after hstate is set up */ 799 if (setsize > NO_SIZE) { 800 struct hstate *h = pconfig->hstate; 801 if (setsize == SIZE_PERCENT) { 802 size <<= huge_page_shift(h); 803 size *= h->max_huge_pages; 804 do_div(size, 100); 805 } 806 pconfig->nr_blocks = (size >> huge_page_shift(h)); 807 } 808 809 return 0; 810 811 bad_val: 812 printk(KERN_ERR "hugetlbfs: Bad value '%s' for mount option '%s'\n", 813 args[0].from, p); 814 return -EINVAL; 815 } 816 817 static int 818 hugetlbfs_fill_super(struct super_block *sb, void *data, int silent) 819 { 820 struct inode * inode; 821 struct dentry * root; 822 int ret; 823 struct hugetlbfs_config config; 824 struct hugetlbfs_sb_info *sbinfo; 825 826 save_mount_options(sb, data); 827 828 config.nr_blocks = -1; /* No limit on size by default */ 829 config.nr_inodes = -1; /* No limit on number of inodes by default */ 830 config.uid = current_fsuid(); 831 config.gid = current_fsgid(); 832 config.mode = 0755; 833 config.hstate = &default_hstate; 834 ret = hugetlbfs_parse_options(data, &config); 835 if (ret) 836 return ret; 837 838 sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL); 839 if (!sbinfo) 840 return -ENOMEM; 841 sb->s_fs_info = sbinfo; 842 sbinfo->hstate = config.hstate; 843 spin_lock_init(&sbinfo->stat_lock); 844 sbinfo->max_blocks = config.nr_blocks; 845 sbinfo->free_blocks = config.nr_blocks; 846 sbinfo->max_inodes = config.nr_inodes; 847 sbinfo->free_inodes = config.nr_inodes; 848 sb->s_maxbytes = MAX_LFS_FILESIZE; 849 sb->s_blocksize = huge_page_size(config.hstate); 850 sb->s_blocksize_bits = huge_page_shift(config.hstate); 851 sb->s_magic = HUGETLBFS_MAGIC; 852 sb->s_op = &hugetlbfs_ops; 853 sb->s_time_gran = 1; 854 inode = hugetlbfs_get_inode(sb, config.uid, config.gid, 855 S_IFDIR | config.mode, 0); 856 if (!inode) 857 goto out_free; 858 859 root = d_alloc_root(inode); 860 if (!root) { 861 iput(inode); 862 goto out_free; 863 } 864 sb->s_root = root; 865 return 0; 866 out_free: 867 kfree(sbinfo); 868 return -ENOMEM; 869 } 870 871 int hugetlb_get_quota(struct address_space *mapping, long delta) 872 { 873 int ret = 0; 874 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); 875 876 if (sbinfo->free_blocks > -1) { 877 spin_lock(&sbinfo->stat_lock); 878 if (sbinfo->free_blocks - delta >= 0) 879 sbinfo->free_blocks -= delta; 880 else 881 ret = -ENOMEM; 882 spin_unlock(&sbinfo->stat_lock); 883 } 884 885 return ret; 886 } 887 888 void hugetlb_put_quota(struct address_space *mapping, long delta) 889 { 890 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); 891 892 if (sbinfo->free_blocks > -1) { 893 spin_lock(&sbinfo->stat_lock); 894 sbinfo->free_blocks += delta; 895 spin_unlock(&sbinfo->stat_lock); 896 } 897 } 898 899 static struct dentry *hugetlbfs_mount(struct file_system_type *fs_type, 900 int flags, const char *dev_name, void *data) 901 { 902 return mount_nodev(fs_type, flags, data, hugetlbfs_fill_super); 903 } 904 905 static struct file_system_type hugetlbfs_fs_type = { 906 .name = "hugetlbfs", 907 .mount = hugetlbfs_mount, 908 .kill_sb = kill_litter_super, 909 }; 910 911 static struct vfsmount *hugetlbfs_vfsmount; 912 913 static int can_do_hugetlb_shm(void) 914 { 915 return capable(CAP_IPC_LOCK) || in_group_p(sysctl_hugetlb_shm_group); 916 } 917 918 struct file *hugetlb_file_setup(const char *name, size_t size, int acctflag, 919 struct user_struct **user, int creat_flags) 920 { 921 int error = -ENOMEM; 922 struct file *file; 923 struct inode *inode; 924 struct path path; 925 struct dentry *root; 926 struct qstr quick_string; 927 928 *user = NULL; 929 if (!hugetlbfs_vfsmount) 930 return ERR_PTR(-ENOENT); 931 932 if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) { 933 *user = current_user(); 934 if (user_shm_lock(size, *user)) { 935 printk_once(KERN_WARNING "Using mlock ulimits for SHM_HUGETLB is deprecated\n"); 936 } else { 937 *user = NULL; 938 return ERR_PTR(-EPERM); 939 } 940 } 941 942 root = hugetlbfs_vfsmount->mnt_root; 943 quick_string.name = name; 944 quick_string.len = strlen(quick_string.name); 945 quick_string.hash = 0; 946 path.dentry = d_alloc(root, &quick_string); 947 if (!path.dentry) 948 goto out_shm_unlock; 949 950 path.mnt = mntget(hugetlbfs_vfsmount); 951 error = -ENOSPC; 952 inode = hugetlbfs_get_inode(root->d_sb, current_fsuid(), 953 current_fsgid(), S_IFREG | S_IRWXUGO, 0); 954 if (!inode) 955 goto out_dentry; 956 957 error = -ENOMEM; 958 if (hugetlb_reserve_pages(inode, 0, 959 size >> huge_page_shift(hstate_inode(inode)), NULL, 960 acctflag)) 961 goto out_inode; 962 963 d_instantiate(path.dentry, inode); 964 inode->i_size = size; 965 inode->i_nlink = 0; 966 967 error = -ENFILE; 968 file = alloc_file(&path, FMODE_WRITE | FMODE_READ, 969 &hugetlbfs_file_operations); 970 if (!file) 971 goto out_dentry; /* inode is already attached */ 972 973 return file; 974 975 out_inode: 976 iput(inode); 977 out_dentry: 978 path_put(&path); 979 out_shm_unlock: 980 if (*user) { 981 user_shm_unlock(size, *user); 982 *user = NULL; 983 } 984 return ERR_PTR(error); 985 } 986 987 static int __init init_hugetlbfs_fs(void) 988 { 989 int error; 990 struct vfsmount *vfsmount; 991 992 error = bdi_init(&hugetlbfs_backing_dev_info); 993 if (error) 994 return error; 995 996 hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache", 997 sizeof(struct hugetlbfs_inode_info), 998 0, 0, init_once); 999 if (hugetlbfs_inode_cachep == NULL) 1000 goto out2; 1001 1002 error = register_filesystem(&hugetlbfs_fs_type); 1003 if (error) 1004 goto out; 1005 1006 vfsmount = kern_mount(&hugetlbfs_fs_type); 1007 1008 if (!IS_ERR(vfsmount)) { 1009 hugetlbfs_vfsmount = vfsmount; 1010 return 0; 1011 } 1012 1013 error = PTR_ERR(vfsmount); 1014 1015 out: 1016 if (error) 1017 kmem_cache_destroy(hugetlbfs_inode_cachep); 1018 out2: 1019 bdi_destroy(&hugetlbfs_backing_dev_info); 1020 return error; 1021 } 1022 1023 static void __exit exit_hugetlbfs_fs(void) 1024 { 1025 kmem_cache_destroy(hugetlbfs_inode_cachep); 1026 unregister_filesystem(&hugetlbfs_fs_type); 1027 bdi_destroy(&hugetlbfs_backing_dev_info); 1028 } 1029 1030 module_init(init_hugetlbfs_fs) 1031 module_exit(exit_hugetlbfs_fs) 1032 1033 MODULE_LICENSE("GPL"); 1034