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 delete_from_page_cache(page); 336 } 337 338 static void truncate_hugepages(struct inode *inode, loff_t lstart) 339 { 340 struct hstate *h = hstate_inode(inode); 341 struct address_space *mapping = &inode->i_data; 342 const pgoff_t start = lstart >> huge_page_shift(h); 343 struct pagevec pvec; 344 pgoff_t next; 345 int i, freed = 0; 346 347 pagevec_init(&pvec, 0); 348 next = start; 349 while (1) { 350 if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) { 351 if (next == start) 352 break; 353 next = start; 354 continue; 355 } 356 357 for (i = 0; i < pagevec_count(&pvec); ++i) { 358 struct page *page = pvec.pages[i]; 359 360 lock_page(page); 361 if (page->index > next) 362 next = page->index; 363 ++next; 364 truncate_huge_page(page); 365 unlock_page(page); 366 freed++; 367 } 368 huge_pagevec_release(&pvec); 369 } 370 BUG_ON(!lstart && mapping->nrpages); 371 hugetlb_unreserve_pages(inode, start, freed); 372 } 373 374 static void hugetlbfs_evict_inode(struct inode *inode) 375 { 376 truncate_hugepages(inode, 0); 377 end_writeback(inode); 378 } 379 380 static inline void 381 hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff) 382 { 383 struct vm_area_struct *vma; 384 struct prio_tree_iter iter; 385 386 vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) { 387 unsigned long v_offset; 388 389 /* 390 * Can the expression below overflow on 32-bit arches? 391 * No, because the prio_tree returns us only those vmas 392 * which overlap the truncated area starting at pgoff, 393 * and no vma on a 32-bit arch can span beyond the 4GB. 394 */ 395 if (vma->vm_pgoff < pgoff) 396 v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT; 397 else 398 v_offset = 0; 399 400 __unmap_hugepage_range(vma, 401 vma->vm_start + v_offset, vma->vm_end, NULL); 402 } 403 } 404 405 static int hugetlb_vmtruncate(struct inode *inode, loff_t offset) 406 { 407 pgoff_t pgoff; 408 struct address_space *mapping = inode->i_mapping; 409 struct hstate *h = hstate_inode(inode); 410 411 BUG_ON(offset & ~huge_page_mask(h)); 412 pgoff = offset >> PAGE_SHIFT; 413 414 i_size_write(inode, offset); 415 spin_lock(&mapping->i_mmap_lock); 416 if (!prio_tree_empty(&mapping->i_mmap)) 417 hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff); 418 spin_unlock(&mapping->i_mmap_lock); 419 truncate_hugepages(inode, offset); 420 return 0; 421 } 422 423 static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr) 424 { 425 struct inode *inode = dentry->d_inode; 426 struct hstate *h = hstate_inode(inode); 427 int error; 428 unsigned int ia_valid = attr->ia_valid; 429 430 BUG_ON(!inode); 431 432 error = inode_change_ok(inode, attr); 433 if (error) 434 return error; 435 436 if (ia_valid & ATTR_SIZE) { 437 error = -EINVAL; 438 if (attr->ia_size & ~huge_page_mask(h)) 439 return -EINVAL; 440 error = hugetlb_vmtruncate(inode, attr->ia_size); 441 if (error) 442 return error; 443 } 444 445 setattr_copy(inode, attr); 446 mark_inode_dirty(inode); 447 return 0; 448 } 449 450 static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid, 451 gid_t gid, int mode, dev_t dev) 452 { 453 struct inode *inode; 454 455 inode = new_inode(sb); 456 if (inode) { 457 struct hugetlbfs_inode_info *info; 458 inode->i_ino = get_next_ino(); 459 inode->i_mode = mode; 460 inode->i_uid = uid; 461 inode->i_gid = gid; 462 inode->i_mapping->a_ops = &hugetlbfs_aops; 463 inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info; 464 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; 465 INIT_LIST_HEAD(&inode->i_mapping->private_list); 466 info = HUGETLBFS_I(inode); 467 /* 468 * The policy is initialized here even if we are creating a 469 * private inode because initialization simply creates an 470 * an empty rb tree and calls spin_lock_init(), later when we 471 * call mpol_free_shared_policy() it will just return because 472 * the rb tree will still be empty. 473 */ 474 mpol_shared_policy_init(&info->policy, NULL); 475 switch (mode & S_IFMT) { 476 default: 477 init_special_inode(inode, mode, dev); 478 break; 479 case S_IFREG: 480 inode->i_op = &hugetlbfs_inode_operations; 481 inode->i_fop = &hugetlbfs_file_operations; 482 break; 483 case S_IFDIR: 484 inode->i_op = &hugetlbfs_dir_inode_operations; 485 inode->i_fop = &simple_dir_operations; 486 487 /* directory inodes start off with i_nlink == 2 (for "." entry) */ 488 inc_nlink(inode); 489 break; 490 case S_IFLNK: 491 inode->i_op = &page_symlink_inode_operations; 492 break; 493 } 494 } 495 return inode; 496 } 497 498 /* 499 * File creation. Allocate an inode, and we're done.. 500 */ 501 static int hugetlbfs_mknod(struct inode *dir, 502 struct dentry *dentry, int mode, dev_t dev) 503 { 504 struct inode *inode; 505 int error = -ENOSPC; 506 gid_t gid; 507 508 if (dir->i_mode & S_ISGID) { 509 gid = dir->i_gid; 510 if (S_ISDIR(mode)) 511 mode |= S_ISGID; 512 } else { 513 gid = current_fsgid(); 514 } 515 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), gid, mode, dev); 516 if (inode) { 517 dir->i_ctime = dir->i_mtime = CURRENT_TIME; 518 d_instantiate(dentry, inode); 519 dget(dentry); /* Extra count - pin the dentry in core */ 520 error = 0; 521 } 522 return error; 523 } 524 525 static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) 526 { 527 int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0); 528 if (!retval) 529 inc_nlink(dir); 530 return retval; 531 } 532 533 static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) 534 { 535 return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0); 536 } 537 538 static int hugetlbfs_symlink(struct inode *dir, 539 struct dentry *dentry, const char *symname) 540 { 541 struct inode *inode; 542 int error = -ENOSPC; 543 gid_t gid; 544 545 if (dir->i_mode & S_ISGID) 546 gid = dir->i_gid; 547 else 548 gid = current_fsgid(); 549 550 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), 551 gid, S_IFLNK|S_IRWXUGO, 0); 552 if (inode) { 553 int l = strlen(symname)+1; 554 error = page_symlink(inode, symname, l); 555 if (!error) { 556 d_instantiate(dentry, inode); 557 dget(dentry); 558 } else 559 iput(inode); 560 } 561 dir->i_ctime = dir->i_mtime = CURRENT_TIME; 562 563 return error; 564 } 565 566 /* 567 * mark the head page dirty 568 */ 569 static int hugetlbfs_set_page_dirty(struct page *page) 570 { 571 struct page *head = compound_head(page); 572 573 SetPageDirty(head); 574 return 0; 575 } 576 577 static int hugetlbfs_migrate_page(struct address_space *mapping, 578 struct page *newpage, struct page *page) 579 { 580 int rc; 581 582 rc = migrate_huge_page_move_mapping(mapping, newpage, page); 583 if (rc) 584 return rc; 585 migrate_page_copy(newpage, page); 586 587 return 0; 588 } 589 590 static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf) 591 { 592 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb); 593 struct hstate *h = hstate_inode(dentry->d_inode); 594 595 buf->f_type = HUGETLBFS_MAGIC; 596 buf->f_bsize = huge_page_size(h); 597 if (sbinfo) { 598 spin_lock(&sbinfo->stat_lock); 599 /* If no limits set, just report 0 for max/free/used 600 * blocks, like simple_statfs() */ 601 if (sbinfo->max_blocks >= 0) { 602 buf->f_blocks = sbinfo->max_blocks; 603 buf->f_bavail = buf->f_bfree = sbinfo->free_blocks; 604 buf->f_files = sbinfo->max_inodes; 605 buf->f_ffree = sbinfo->free_inodes; 606 } 607 spin_unlock(&sbinfo->stat_lock); 608 } 609 buf->f_namelen = NAME_MAX; 610 return 0; 611 } 612 613 static void hugetlbfs_put_super(struct super_block *sb) 614 { 615 struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb); 616 617 if (sbi) { 618 sb->s_fs_info = NULL; 619 kfree(sbi); 620 } 621 } 622 623 static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo) 624 { 625 if (sbinfo->free_inodes >= 0) { 626 spin_lock(&sbinfo->stat_lock); 627 if (unlikely(!sbinfo->free_inodes)) { 628 spin_unlock(&sbinfo->stat_lock); 629 return 0; 630 } 631 sbinfo->free_inodes--; 632 spin_unlock(&sbinfo->stat_lock); 633 } 634 635 return 1; 636 } 637 638 static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo) 639 { 640 if (sbinfo->free_inodes >= 0) { 641 spin_lock(&sbinfo->stat_lock); 642 sbinfo->free_inodes++; 643 spin_unlock(&sbinfo->stat_lock); 644 } 645 } 646 647 648 static struct kmem_cache *hugetlbfs_inode_cachep; 649 650 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb) 651 { 652 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); 653 struct hugetlbfs_inode_info *p; 654 655 if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo))) 656 return NULL; 657 p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL); 658 if (unlikely(!p)) { 659 hugetlbfs_inc_free_inodes(sbinfo); 660 return NULL; 661 } 662 return &p->vfs_inode; 663 } 664 665 static void hugetlbfs_i_callback(struct rcu_head *head) 666 { 667 struct inode *inode = container_of(head, struct inode, i_rcu); 668 INIT_LIST_HEAD(&inode->i_dentry); 669 kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode)); 670 } 671 672 static void hugetlbfs_destroy_inode(struct inode *inode) 673 { 674 hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb)); 675 mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy); 676 call_rcu(&inode->i_rcu, hugetlbfs_i_callback); 677 } 678 679 static const struct address_space_operations hugetlbfs_aops = { 680 .write_begin = hugetlbfs_write_begin, 681 .write_end = hugetlbfs_write_end, 682 .set_page_dirty = hugetlbfs_set_page_dirty, 683 .migratepage = hugetlbfs_migrate_page, 684 }; 685 686 687 static void init_once(void *foo) 688 { 689 struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo; 690 691 inode_init_once(&ei->vfs_inode); 692 } 693 694 const struct file_operations hugetlbfs_file_operations = { 695 .read = hugetlbfs_read, 696 .mmap = hugetlbfs_file_mmap, 697 .fsync = noop_fsync, 698 .get_unmapped_area = hugetlb_get_unmapped_area, 699 .llseek = default_llseek, 700 }; 701 702 static const struct inode_operations hugetlbfs_dir_inode_operations = { 703 .create = hugetlbfs_create, 704 .lookup = simple_lookup, 705 .link = simple_link, 706 .unlink = simple_unlink, 707 .symlink = hugetlbfs_symlink, 708 .mkdir = hugetlbfs_mkdir, 709 .rmdir = simple_rmdir, 710 .mknod = hugetlbfs_mknod, 711 .rename = simple_rename, 712 .setattr = hugetlbfs_setattr, 713 }; 714 715 static const struct inode_operations hugetlbfs_inode_operations = { 716 .setattr = hugetlbfs_setattr, 717 }; 718 719 static const struct super_operations hugetlbfs_ops = { 720 .alloc_inode = hugetlbfs_alloc_inode, 721 .destroy_inode = hugetlbfs_destroy_inode, 722 .evict_inode = hugetlbfs_evict_inode, 723 .statfs = hugetlbfs_statfs, 724 .put_super = hugetlbfs_put_super, 725 .show_options = generic_show_options, 726 }; 727 728 static int 729 hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig) 730 { 731 char *p, *rest; 732 substring_t args[MAX_OPT_ARGS]; 733 int option; 734 unsigned long long size = 0; 735 enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = NO_SIZE; 736 737 if (!options) 738 return 0; 739 740 while ((p = strsep(&options, ",")) != NULL) { 741 int token; 742 if (!*p) 743 continue; 744 745 token = match_token(p, tokens, args); 746 switch (token) { 747 case Opt_uid: 748 if (match_int(&args[0], &option)) 749 goto bad_val; 750 pconfig->uid = option; 751 break; 752 753 case Opt_gid: 754 if (match_int(&args[0], &option)) 755 goto bad_val; 756 pconfig->gid = option; 757 break; 758 759 case Opt_mode: 760 if (match_octal(&args[0], &option)) 761 goto bad_val; 762 pconfig->mode = option & 01777U; 763 break; 764 765 case Opt_size: { 766 /* memparse() will accept a K/M/G without a digit */ 767 if (!isdigit(*args[0].from)) 768 goto bad_val; 769 size = memparse(args[0].from, &rest); 770 setsize = SIZE_STD; 771 if (*rest == '%') 772 setsize = SIZE_PERCENT; 773 break; 774 } 775 776 case Opt_nr_inodes: 777 /* memparse() will accept a K/M/G without a digit */ 778 if (!isdigit(*args[0].from)) 779 goto bad_val; 780 pconfig->nr_inodes = memparse(args[0].from, &rest); 781 break; 782 783 case Opt_pagesize: { 784 unsigned long ps; 785 ps = memparse(args[0].from, &rest); 786 pconfig->hstate = size_to_hstate(ps); 787 if (!pconfig->hstate) { 788 printk(KERN_ERR 789 "hugetlbfs: Unsupported page size %lu MB\n", 790 ps >> 20); 791 return -EINVAL; 792 } 793 break; 794 } 795 796 default: 797 printk(KERN_ERR "hugetlbfs: Bad mount option: \"%s\"\n", 798 p); 799 return -EINVAL; 800 break; 801 } 802 } 803 804 /* Do size after hstate is set up */ 805 if (setsize > NO_SIZE) { 806 struct hstate *h = pconfig->hstate; 807 if (setsize == SIZE_PERCENT) { 808 size <<= huge_page_shift(h); 809 size *= h->max_huge_pages; 810 do_div(size, 100); 811 } 812 pconfig->nr_blocks = (size >> huge_page_shift(h)); 813 } 814 815 return 0; 816 817 bad_val: 818 printk(KERN_ERR "hugetlbfs: Bad value '%s' for mount option '%s'\n", 819 args[0].from, p); 820 return -EINVAL; 821 } 822 823 static int 824 hugetlbfs_fill_super(struct super_block *sb, void *data, int silent) 825 { 826 struct inode * inode; 827 struct dentry * root; 828 int ret; 829 struct hugetlbfs_config config; 830 struct hugetlbfs_sb_info *sbinfo; 831 832 save_mount_options(sb, data); 833 834 config.nr_blocks = -1; /* No limit on size by default */ 835 config.nr_inodes = -1; /* No limit on number of inodes by default */ 836 config.uid = current_fsuid(); 837 config.gid = current_fsgid(); 838 config.mode = 0755; 839 config.hstate = &default_hstate; 840 ret = hugetlbfs_parse_options(data, &config); 841 if (ret) 842 return ret; 843 844 sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL); 845 if (!sbinfo) 846 return -ENOMEM; 847 sb->s_fs_info = sbinfo; 848 sbinfo->hstate = config.hstate; 849 spin_lock_init(&sbinfo->stat_lock); 850 sbinfo->max_blocks = config.nr_blocks; 851 sbinfo->free_blocks = config.nr_blocks; 852 sbinfo->max_inodes = config.nr_inodes; 853 sbinfo->free_inodes = config.nr_inodes; 854 sb->s_maxbytes = MAX_LFS_FILESIZE; 855 sb->s_blocksize = huge_page_size(config.hstate); 856 sb->s_blocksize_bits = huge_page_shift(config.hstate); 857 sb->s_magic = HUGETLBFS_MAGIC; 858 sb->s_op = &hugetlbfs_ops; 859 sb->s_time_gran = 1; 860 inode = hugetlbfs_get_inode(sb, config.uid, config.gid, 861 S_IFDIR | config.mode, 0); 862 if (!inode) 863 goto out_free; 864 865 root = d_alloc_root(inode); 866 if (!root) { 867 iput(inode); 868 goto out_free; 869 } 870 sb->s_root = root; 871 return 0; 872 out_free: 873 kfree(sbinfo); 874 return -ENOMEM; 875 } 876 877 int hugetlb_get_quota(struct address_space *mapping, long delta) 878 { 879 int ret = 0; 880 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); 881 882 if (sbinfo->free_blocks > -1) { 883 spin_lock(&sbinfo->stat_lock); 884 if (sbinfo->free_blocks - delta >= 0) 885 sbinfo->free_blocks -= delta; 886 else 887 ret = -ENOMEM; 888 spin_unlock(&sbinfo->stat_lock); 889 } 890 891 return ret; 892 } 893 894 void hugetlb_put_quota(struct address_space *mapping, long delta) 895 { 896 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); 897 898 if (sbinfo->free_blocks > -1) { 899 spin_lock(&sbinfo->stat_lock); 900 sbinfo->free_blocks += delta; 901 spin_unlock(&sbinfo->stat_lock); 902 } 903 } 904 905 static struct dentry *hugetlbfs_mount(struct file_system_type *fs_type, 906 int flags, const char *dev_name, void *data) 907 { 908 return mount_nodev(fs_type, flags, data, hugetlbfs_fill_super); 909 } 910 911 static struct file_system_type hugetlbfs_fs_type = { 912 .name = "hugetlbfs", 913 .mount = hugetlbfs_mount, 914 .kill_sb = kill_litter_super, 915 }; 916 917 static struct vfsmount *hugetlbfs_vfsmount; 918 919 static int can_do_hugetlb_shm(void) 920 { 921 return capable(CAP_IPC_LOCK) || in_group_p(sysctl_hugetlb_shm_group); 922 } 923 924 struct file *hugetlb_file_setup(const char *name, size_t size, int acctflag, 925 struct user_struct **user, int creat_flags) 926 { 927 int error = -ENOMEM; 928 struct file *file; 929 struct inode *inode; 930 struct path path; 931 struct dentry *root; 932 struct qstr quick_string; 933 934 *user = NULL; 935 if (!hugetlbfs_vfsmount) 936 return ERR_PTR(-ENOENT); 937 938 if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) { 939 *user = current_user(); 940 if (user_shm_lock(size, *user)) { 941 printk_once(KERN_WARNING "Using mlock ulimits for SHM_HUGETLB is deprecated\n"); 942 } else { 943 *user = NULL; 944 return ERR_PTR(-EPERM); 945 } 946 } 947 948 root = hugetlbfs_vfsmount->mnt_root; 949 quick_string.name = name; 950 quick_string.len = strlen(quick_string.name); 951 quick_string.hash = 0; 952 path.dentry = d_alloc(root, &quick_string); 953 if (!path.dentry) 954 goto out_shm_unlock; 955 956 path.mnt = mntget(hugetlbfs_vfsmount); 957 error = -ENOSPC; 958 inode = hugetlbfs_get_inode(root->d_sb, current_fsuid(), 959 current_fsgid(), S_IFREG | S_IRWXUGO, 0); 960 if (!inode) 961 goto out_dentry; 962 963 error = -ENOMEM; 964 if (hugetlb_reserve_pages(inode, 0, 965 size >> huge_page_shift(hstate_inode(inode)), NULL, 966 acctflag)) 967 goto out_inode; 968 969 d_instantiate(path.dentry, inode); 970 inode->i_size = size; 971 inode->i_nlink = 0; 972 973 error = -ENFILE; 974 file = alloc_file(&path, FMODE_WRITE | FMODE_READ, 975 &hugetlbfs_file_operations); 976 if (!file) 977 goto out_dentry; /* inode is already attached */ 978 979 return file; 980 981 out_inode: 982 iput(inode); 983 out_dentry: 984 path_put(&path); 985 out_shm_unlock: 986 if (*user) { 987 user_shm_unlock(size, *user); 988 *user = NULL; 989 } 990 return ERR_PTR(error); 991 } 992 993 static int __init init_hugetlbfs_fs(void) 994 { 995 int error; 996 struct vfsmount *vfsmount; 997 998 error = bdi_init(&hugetlbfs_backing_dev_info); 999 if (error) 1000 return error; 1001 1002 hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache", 1003 sizeof(struct hugetlbfs_inode_info), 1004 0, 0, init_once); 1005 if (hugetlbfs_inode_cachep == NULL) 1006 goto out2; 1007 1008 error = register_filesystem(&hugetlbfs_fs_type); 1009 if (error) 1010 goto out; 1011 1012 vfsmount = kern_mount(&hugetlbfs_fs_type); 1013 1014 if (!IS_ERR(vfsmount)) { 1015 hugetlbfs_vfsmount = vfsmount; 1016 return 0; 1017 } 1018 1019 error = PTR_ERR(vfsmount); 1020 1021 out: 1022 if (error) 1023 kmem_cache_destroy(hugetlbfs_inode_cachep); 1024 out2: 1025 bdi_destroy(&hugetlbfs_backing_dev_info); 1026 return error; 1027 } 1028 1029 static void __exit exit_hugetlbfs_fs(void) 1030 { 1031 kmem_cache_destroy(hugetlbfs_inode_cachep); 1032 unregister_filesystem(&hugetlbfs_fs_type); 1033 bdi_destroy(&hugetlbfs_backing_dev_info); 1034 } 1035 1036 module_init(init_hugetlbfs_fs) 1037 module_exit(exit_hugetlbfs_fs) 1038 1039 MODULE_LICENSE("GPL"); 1040