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/ima.h> 34 35 #include <asm/uaccess.h> 36 37 /* some random number */ 38 #define HUGETLBFS_MAGIC 0x958458f6 39 40 static const struct super_operations hugetlbfs_ops; 41 static const struct address_space_operations hugetlbfs_aops; 42 const struct file_operations hugetlbfs_file_operations; 43 static const struct inode_operations hugetlbfs_dir_inode_operations; 44 static const struct inode_operations hugetlbfs_inode_operations; 45 46 static struct backing_dev_info hugetlbfs_backing_dev_info = { 47 .ra_pages = 0, /* No readahead */ 48 .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK, 49 }; 50 51 int sysctl_hugetlb_shm_group; 52 53 enum { 54 Opt_size, Opt_nr_inodes, 55 Opt_mode, Opt_uid, Opt_gid, 56 Opt_pagesize, 57 Opt_err, 58 }; 59 60 static const match_table_t tokens = { 61 {Opt_size, "size=%s"}, 62 {Opt_nr_inodes, "nr_inodes=%s"}, 63 {Opt_mode, "mode=%o"}, 64 {Opt_uid, "uid=%u"}, 65 {Opt_gid, "gid=%u"}, 66 {Opt_pagesize, "pagesize=%s"}, 67 {Opt_err, NULL}, 68 }; 69 70 static void huge_pagevec_release(struct pagevec *pvec) 71 { 72 int i; 73 74 for (i = 0; i < pagevec_count(pvec); ++i) 75 put_page(pvec->pages[i]); 76 77 pagevec_reinit(pvec); 78 } 79 80 static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma) 81 { 82 struct inode *inode = file->f_path.dentry->d_inode; 83 loff_t len, vma_len; 84 int ret; 85 struct hstate *h = hstate_file(file); 86 87 /* 88 * vma address alignment (but not the pgoff alignment) has 89 * already been checked by prepare_hugepage_range. If you add 90 * any error returns here, do so after setting VM_HUGETLB, so 91 * is_vm_hugetlb_page tests below unmap_region go the right 92 * way when do_mmap_pgoff unwinds (may be important on powerpc 93 * and ia64). 94 */ 95 vma->vm_flags |= VM_HUGETLB | VM_RESERVED; 96 vma->vm_ops = &hugetlb_vm_ops; 97 98 if (vma->vm_pgoff & ~(huge_page_mask(h) >> PAGE_SHIFT)) 99 return -EINVAL; 100 101 vma_len = (loff_t)(vma->vm_end - vma->vm_start); 102 103 mutex_lock(&inode->i_mutex); 104 file_accessed(file); 105 106 ret = -ENOMEM; 107 len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); 108 109 if (hugetlb_reserve_pages(inode, 110 vma->vm_pgoff >> huge_page_order(h), 111 len >> huge_page_shift(h), vma, 112 vma->vm_flags)) 113 goto out; 114 115 ret = 0; 116 hugetlb_prefault_arch_hook(vma->vm_mm); 117 if (vma->vm_flags & VM_WRITE && inode->i_size < len) 118 inode->i_size = len; 119 out: 120 mutex_unlock(&inode->i_mutex); 121 122 return ret; 123 } 124 125 /* 126 * Called under down_write(mmap_sem). 127 */ 128 129 #ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA 130 static unsigned long 131 hugetlb_get_unmapped_area(struct file *file, unsigned long addr, 132 unsigned long len, unsigned long pgoff, unsigned long flags) 133 { 134 struct mm_struct *mm = current->mm; 135 struct vm_area_struct *vma; 136 unsigned long start_addr; 137 struct hstate *h = hstate_file(file); 138 139 if (len & ~huge_page_mask(h)) 140 return -EINVAL; 141 if (len > TASK_SIZE) 142 return -ENOMEM; 143 144 if (flags & MAP_FIXED) { 145 if (prepare_hugepage_range(file, addr, len)) 146 return -EINVAL; 147 return addr; 148 } 149 150 if (addr) { 151 addr = ALIGN(addr, huge_page_size(h)); 152 vma = find_vma(mm, addr); 153 if (TASK_SIZE - len >= addr && 154 (!vma || addr + len <= vma->vm_start)) 155 return addr; 156 } 157 158 start_addr = mm->free_area_cache; 159 160 if (len <= mm->cached_hole_size) 161 start_addr = TASK_UNMAPPED_BASE; 162 163 full_search: 164 addr = ALIGN(start_addr, huge_page_size(h)); 165 166 for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { 167 /* At this point: (!vma || addr < vma->vm_end). */ 168 if (TASK_SIZE - len < addr) { 169 /* 170 * Start a new search - just in case we missed 171 * some holes. 172 */ 173 if (start_addr != TASK_UNMAPPED_BASE) { 174 start_addr = TASK_UNMAPPED_BASE; 175 goto full_search; 176 } 177 return -ENOMEM; 178 } 179 180 if (!vma || addr + len <= vma->vm_start) 181 return addr; 182 addr = ALIGN(vma->vm_end, huge_page_size(h)); 183 } 184 } 185 #endif 186 187 static int 188 hugetlbfs_read_actor(struct page *page, unsigned long offset, 189 char __user *buf, unsigned long count, 190 unsigned long size) 191 { 192 char *kaddr; 193 unsigned long left, copied = 0; 194 int i, chunksize; 195 196 if (size > count) 197 size = count; 198 199 /* Find which 4k chunk and offset with in that chunk */ 200 i = offset >> PAGE_CACHE_SHIFT; 201 offset = offset & ~PAGE_CACHE_MASK; 202 203 while (size) { 204 chunksize = PAGE_CACHE_SIZE; 205 if (offset) 206 chunksize -= offset; 207 if (chunksize > size) 208 chunksize = size; 209 kaddr = kmap(&page[i]); 210 left = __copy_to_user(buf, kaddr + offset, chunksize); 211 kunmap(&page[i]); 212 if (left) { 213 copied += (chunksize - left); 214 break; 215 } 216 offset = 0; 217 size -= chunksize; 218 buf += chunksize; 219 copied += chunksize; 220 i++; 221 } 222 return copied ? copied : -EFAULT; 223 } 224 225 /* 226 * Support for read() - Find the page attached to f_mapping and copy out the 227 * data. Its *very* similar to do_generic_mapping_read(), we can't use that 228 * since it has PAGE_CACHE_SIZE assumptions. 229 */ 230 static ssize_t hugetlbfs_read(struct file *filp, char __user *buf, 231 size_t len, loff_t *ppos) 232 { 233 struct hstate *h = hstate_file(filp); 234 struct address_space *mapping = filp->f_mapping; 235 struct inode *inode = mapping->host; 236 unsigned long index = *ppos >> huge_page_shift(h); 237 unsigned long offset = *ppos & ~huge_page_mask(h); 238 unsigned long end_index; 239 loff_t isize; 240 ssize_t retval = 0; 241 242 mutex_lock(&inode->i_mutex); 243 244 /* validate length */ 245 if (len == 0) 246 goto out; 247 248 isize = i_size_read(inode); 249 if (!isize) 250 goto out; 251 252 end_index = (isize - 1) >> huge_page_shift(h); 253 for (;;) { 254 struct page *page; 255 unsigned long nr, ret; 256 int ra; 257 258 /* nr is the maximum number of bytes to copy from this page */ 259 nr = huge_page_size(h); 260 if (index >= end_index) { 261 if (index > end_index) 262 goto out; 263 nr = ((isize - 1) & ~huge_page_mask(h)) + 1; 264 if (nr <= offset) { 265 goto out; 266 } 267 } 268 nr = nr - offset; 269 270 /* Find the page */ 271 page = find_get_page(mapping, index); 272 if (unlikely(page == NULL)) { 273 /* 274 * We have a HOLE, zero out the user-buffer for the 275 * length of the hole or request. 276 */ 277 ret = len < nr ? len : nr; 278 if (clear_user(buf, ret)) 279 ra = -EFAULT; 280 else 281 ra = 0; 282 } else { 283 /* 284 * We have the page, copy it to user space buffer. 285 */ 286 ra = hugetlbfs_read_actor(page, offset, buf, len, nr); 287 ret = ra; 288 } 289 if (ra < 0) { 290 if (retval == 0) 291 retval = ra; 292 if (page) 293 page_cache_release(page); 294 goto out; 295 } 296 297 offset += ret; 298 retval += ret; 299 len -= ret; 300 index += offset >> huge_page_shift(h); 301 offset &= ~huge_page_mask(h); 302 303 if (page) 304 page_cache_release(page); 305 306 /* short read or no more work */ 307 if ((ret != nr) || (len == 0)) 308 break; 309 } 310 out: 311 *ppos = ((loff_t)index << huge_page_shift(h)) + offset; 312 mutex_unlock(&inode->i_mutex); 313 return retval; 314 } 315 316 static int hugetlbfs_write_begin(struct file *file, 317 struct address_space *mapping, 318 loff_t pos, unsigned len, unsigned flags, 319 struct page **pagep, void **fsdata) 320 { 321 return -EINVAL; 322 } 323 324 static int hugetlbfs_write_end(struct file *file, struct address_space *mapping, 325 loff_t pos, unsigned len, unsigned copied, 326 struct page *page, void *fsdata) 327 { 328 BUG(); 329 return -EINVAL; 330 } 331 332 static void truncate_huge_page(struct page *page) 333 { 334 cancel_dirty_page(page, /* No IO accounting for huge pages? */0); 335 ClearPageUptodate(page); 336 remove_from_page_cache(page); 337 put_page(page); 338 } 339 340 static void truncate_hugepages(struct inode *inode, loff_t lstart) 341 { 342 struct hstate *h = hstate_inode(inode); 343 struct address_space *mapping = &inode->i_data; 344 const pgoff_t start = lstart >> huge_page_shift(h); 345 struct pagevec pvec; 346 pgoff_t next; 347 int i, freed = 0; 348 349 pagevec_init(&pvec, 0); 350 next = start; 351 while (1) { 352 if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) { 353 if (next == start) 354 break; 355 next = start; 356 continue; 357 } 358 359 for (i = 0; i < pagevec_count(&pvec); ++i) { 360 struct page *page = pvec.pages[i]; 361 362 lock_page(page); 363 if (page->index > next) 364 next = page->index; 365 ++next; 366 truncate_huge_page(page); 367 unlock_page(page); 368 freed++; 369 } 370 huge_pagevec_release(&pvec); 371 } 372 BUG_ON(!lstart && mapping->nrpages); 373 hugetlb_unreserve_pages(inode, start, freed); 374 } 375 376 static void hugetlbfs_delete_inode(struct inode *inode) 377 { 378 truncate_hugepages(inode, 0); 379 clear_inode(inode); 380 } 381 382 static void hugetlbfs_forget_inode(struct inode *inode) __releases(inode_lock) 383 { 384 struct super_block *sb = inode->i_sb; 385 386 if (!hlist_unhashed(&inode->i_hash)) { 387 if (!(inode->i_state & (I_DIRTY|I_SYNC))) 388 list_move(&inode->i_list, &inode_unused); 389 inodes_stat.nr_unused++; 390 if (!sb || (sb->s_flags & MS_ACTIVE)) { 391 spin_unlock(&inode_lock); 392 return; 393 } 394 inode->i_state |= I_WILL_FREE; 395 spin_unlock(&inode_lock); 396 /* 397 * write_inode_now is a noop as we set BDI_CAP_NO_WRITEBACK 398 * in our backing_dev_info. 399 */ 400 write_inode_now(inode, 1); 401 spin_lock(&inode_lock); 402 inode->i_state &= ~I_WILL_FREE; 403 inodes_stat.nr_unused--; 404 hlist_del_init(&inode->i_hash); 405 } 406 list_del_init(&inode->i_list); 407 list_del_init(&inode->i_sb_list); 408 inode->i_state |= I_FREEING; 409 inodes_stat.nr_inodes--; 410 spin_unlock(&inode_lock); 411 truncate_hugepages(inode, 0); 412 clear_inode(inode); 413 destroy_inode(inode); 414 } 415 416 static void hugetlbfs_drop_inode(struct inode *inode) 417 { 418 if (!inode->i_nlink) 419 generic_delete_inode(inode); 420 else 421 hugetlbfs_forget_inode(inode); 422 } 423 424 static inline void 425 hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff) 426 { 427 struct vm_area_struct *vma; 428 struct prio_tree_iter iter; 429 430 vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) { 431 unsigned long v_offset; 432 433 /* 434 * Can the expression below overflow on 32-bit arches? 435 * No, because the prio_tree returns us only those vmas 436 * which overlap the truncated area starting at pgoff, 437 * and no vma on a 32-bit arch can span beyond the 4GB. 438 */ 439 if (vma->vm_pgoff < pgoff) 440 v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT; 441 else 442 v_offset = 0; 443 444 __unmap_hugepage_range(vma, 445 vma->vm_start + v_offset, vma->vm_end, NULL); 446 } 447 } 448 449 static int hugetlb_vmtruncate(struct inode *inode, loff_t offset) 450 { 451 pgoff_t pgoff; 452 struct address_space *mapping = inode->i_mapping; 453 struct hstate *h = hstate_inode(inode); 454 455 BUG_ON(offset & ~huge_page_mask(h)); 456 pgoff = offset >> PAGE_SHIFT; 457 458 i_size_write(inode, offset); 459 spin_lock(&mapping->i_mmap_lock); 460 if (!prio_tree_empty(&mapping->i_mmap)) 461 hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff); 462 spin_unlock(&mapping->i_mmap_lock); 463 truncate_hugepages(inode, offset); 464 return 0; 465 } 466 467 static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr) 468 { 469 struct inode *inode = dentry->d_inode; 470 struct hstate *h = hstate_inode(inode); 471 int error; 472 unsigned int ia_valid = attr->ia_valid; 473 474 BUG_ON(!inode); 475 476 error = inode_change_ok(inode, attr); 477 if (error) 478 goto out; 479 480 if (ia_valid & ATTR_SIZE) { 481 error = -EINVAL; 482 if (!(attr->ia_size & ~huge_page_mask(h))) 483 error = hugetlb_vmtruncate(inode, attr->ia_size); 484 if (error) 485 goto out; 486 attr->ia_valid &= ~ATTR_SIZE; 487 } 488 error = inode_setattr(inode, attr); 489 out: 490 return error; 491 } 492 493 static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid, 494 gid_t gid, int mode, dev_t dev) 495 { 496 struct inode *inode; 497 498 inode = new_inode(sb); 499 if (inode) { 500 struct hugetlbfs_inode_info *info; 501 inode->i_mode = mode; 502 inode->i_uid = uid; 503 inode->i_gid = gid; 504 inode->i_mapping->a_ops = &hugetlbfs_aops; 505 inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info; 506 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; 507 INIT_LIST_HEAD(&inode->i_mapping->private_list); 508 info = HUGETLBFS_I(inode); 509 mpol_shared_policy_init(&info->policy, NULL); 510 switch (mode & S_IFMT) { 511 default: 512 init_special_inode(inode, mode, dev); 513 break; 514 case S_IFREG: 515 inode->i_op = &hugetlbfs_inode_operations; 516 inode->i_fop = &hugetlbfs_file_operations; 517 break; 518 case S_IFDIR: 519 inode->i_op = &hugetlbfs_dir_inode_operations; 520 inode->i_fop = &simple_dir_operations; 521 522 /* directory inodes start off with i_nlink == 2 (for "." entry) */ 523 inc_nlink(inode); 524 break; 525 case S_IFLNK: 526 inode->i_op = &page_symlink_inode_operations; 527 break; 528 } 529 } 530 return inode; 531 } 532 533 /* 534 * File creation. Allocate an inode, and we're done.. 535 */ 536 static int hugetlbfs_mknod(struct inode *dir, 537 struct dentry *dentry, int mode, dev_t dev) 538 { 539 struct inode *inode; 540 int error = -ENOSPC; 541 gid_t gid; 542 543 if (dir->i_mode & S_ISGID) { 544 gid = dir->i_gid; 545 if (S_ISDIR(mode)) 546 mode |= S_ISGID; 547 } else { 548 gid = current_fsgid(); 549 } 550 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), gid, mode, dev); 551 if (inode) { 552 dir->i_ctime = dir->i_mtime = CURRENT_TIME; 553 d_instantiate(dentry, inode); 554 dget(dentry); /* Extra count - pin the dentry in core */ 555 error = 0; 556 } 557 return error; 558 } 559 560 static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) 561 { 562 int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0); 563 if (!retval) 564 inc_nlink(dir); 565 return retval; 566 } 567 568 static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) 569 { 570 return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0); 571 } 572 573 static int hugetlbfs_symlink(struct inode *dir, 574 struct dentry *dentry, const char *symname) 575 { 576 struct inode *inode; 577 int error = -ENOSPC; 578 gid_t gid; 579 580 if (dir->i_mode & S_ISGID) 581 gid = dir->i_gid; 582 else 583 gid = current_fsgid(); 584 585 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), 586 gid, S_IFLNK|S_IRWXUGO, 0); 587 if (inode) { 588 int l = strlen(symname)+1; 589 error = page_symlink(inode, symname, l); 590 if (!error) { 591 d_instantiate(dentry, inode); 592 dget(dentry); 593 } else 594 iput(inode); 595 } 596 dir->i_ctime = dir->i_mtime = CURRENT_TIME; 597 598 return error; 599 } 600 601 /* 602 * mark the head page dirty 603 */ 604 static int hugetlbfs_set_page_dirty(struct page *page) 605 { 606 struct page *head = compound_head(page); 607 608 SetPageDirty(head); 609 return 0; 610 } 611 612 static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf) 613 { 614 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb); 615 struct hstate *h = hstate_inode(dentry->d_inode); 616 617 buf->f_type = HUGETLBFS_MAGIC; 618 buf->f_bsize = huge_page_size(h); 619 if (sbinfo) { 620 spin_lock(&sbinfo->stat_lock); 621 /* If no limits set, just report 0 for max/free/used 622 * blocks, like simple_statfs() */ 623 if (sbinfo->max_blocks >= 0) { 624 buf->f_blocks = sbinfo->max_blocks; 625 buf->f_bavail = buf->f_bfree = sbinfo->free_blocks; 626 buf->f_files = sbinfo->max_inodes; 627 buf->f_ffree = sbinfo->free_inodes; 628 } 629 spin_unlock(&sbinfo->stat_lock); 630 } 631 buf->f_namelen = NAME_MAX; 632 return 0; 633 } 634 635 static void hugetlbfs_put_super(struct super_block *sb) 636 { 637 struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb); 638 639 if (sbi) { 640 sb->s_fs_info = NULL; 641 kfree(sbi); 642 } 643 } 644 645 static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo) 646 { 647 if (sbinfo->free_inodes >= 0) { 648 spin_lock(&sbinfo->stat_lock); 649 if (unlikely(!sbinfo->free_inodes)) { 650 spin_unlock(&sbinfo->stat_lock); 651 return 0; 652 } 653 sbinfo->free_inodes--; 654 spin_unlock(&sbinfo->stat_lock); 655 } 656 657 return 1; 658 } 659 660 static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo) 661 { 662 if (sbinfo->free_inodes >= 0) { 663 spin_lock(&sbinfo->stat_lock); 664 sbinfo->free_inodes++; 665 spin_unlock(&sbinfo->stat_lock); 666 } 667 } 668 669 670 static struct kmem_cache *hugetlbfs_inode_cachep; 671 672 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb) 673 { 674 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); 675 struct hugetlbfs_inode_info *p; 676 677 if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo))) 678 return NULL; 679 p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL); 680 if (unlikely(!p)) { 681 hugetlbfs_inc_free_inodes(sbinfo); 682 return NULL; 683 } 684 return &p->vfs_inode; 685 } 686 687 static void hugetlbfs_destroy_inode(struct inode *inode) 688 { 689 hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb)); 690 mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy); 691 kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode)); 692 } 693 694 static const struct address_space_operations hugetlbfs_aops = { 695 .write_begin = hugetlbfs_write_begin, 696 .write_end = hugetlbfs_write_end, 697 .set_page_dirty = hugetlbfs_set_page_dirty, 698 }; 699 700 701 static void init_once(void *foo) 702 { 703 struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo; 704 705 inode_init_once(&ei->vfs_inode); 706 } 707 708 const struct file_operations hugetlbfs_file_operations = { 709 .read = hugetlbfs_read, 710 .mmap = hugetlbfs_file_mmap, 711 .fsync = simple_sync_file, 712 .get_unmapped_area = hugetlb_get_unmapped_area, 713 }; 714 715 static const struct inode_operations hugetlbfs_dir_inode_operations = { 716 .create = hugetlbfs_create, 717 .lookup = simple_lookup, 718 .link = simple_link, 719 .unlink = simple_unlink, 720 .symlink = hugetlbfs_symlink, 721 .mkdir = hugetlbfs_mkdir, 722 .rmdir = simple_rmdir, 723 .mknod = hugetlbfs_mknod, 724 .rename = simple_rename, 725 .setattr = hugetlbfs_setattr, 726 }; 727 728 static const struct inode_operations hugetlbfs_inode_operations = { 729 .setattr = hugetlbfs_setattr, 730 }; 731 732 static const struct super_operations hugetlbfs_ops = { 733 .alloc_inode = hugetlbfs_alloc_inode, 734 .destroy_inode = hugetlbfs_destroy_inode, 735 .statfs = hugetlbfs_statfs, 736 .delete_inode = hugetlbfs_delete_inode, 737 .drop_inode = hugetlbfs_drop_inode, 738 .put_super = hugetlbfs_put_super, 739 .show_options = generic_show_options, 740 }; 741 742 static int 743 hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig) 744 { 745 char *p, *rest; 746 substring_t args[MAX_OPT_ARGS]; 747 int option; 748 unsigned long long size = 0; 749 enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = NO_SIZE; 750 751 if (!options) 752 return 0; 753 754 while ((p = strsep(&options, ",")) != NULL) { 755 int token; 756 if (!*p) 757 continue; 758 759 token = match_token(p, tokens, args); 760 switch (token) { 761 case Opt_uid: 762 if (match_int(&args[0], &option)) 763 goto bad_val; 764 pconfig->uid = option; 765 break; 766 767 case Opt_gid: 768 if (match_int(&args[0], &option)) 769 goto bad_val; 770 pconfig->gid = option; 771 break; 772 773 case Opt_mode: 774 if (match_octal(&args[0], &option)) 775 goto bad_val; 776 pconfig->mode = option & 01777U; 777 break; 778 779 case Opt_size: { 780 /* memparse() will accept a K/M/G without a digit */ 781 if (!isdigit(*args[0].from)) 782 goto bad_val; 783 size = memparse(args[0].from, &rest); 784 setsize = SIZE_STD; 785 if (*rest == '%') 786 setsize = SIZE_PERCENT; 787 break; 788 } 789 790 case Opt_nr_inodes: 791 /* memparse() will accept a K/M/G without a digit */ 792 if (!isdigit(*args[0].from)) 793 goto bad_val; 794 pconfig->nr_inodes = memparse(args[0].from, &rest); 795 break; 796 797 case Opt_pagesize: { 798 unsigned long ps; 799 ps = memparse(args[0].from, &rest); 800 pconfig->hstate = size_to_hstate(ps); 801 if (!pconfig->hstate) { 802 printk(KERN_ERR 803 "hugetlbfs: Unsupported page size %lu MB\n", 804 ps >> 20); 805 return -EINVAL; 806 } 807 break; 808 } 809 810 default: 811 printk(KERN_ERR "hugetlbfs: Bad mount option: \"%s\"\n", 812 p); 813 return -EINVAL; 814 break; 815 } 816 } 817 818 /* Do size after hstate is set up */ 819 if (setsize > NO_SIZE) { 820 struct hstate *h = pconfig->hstate; 821 if (setsize == SIZE_PERCENT) { 822 size <<= huge_page_shift(h); 823 size *= h->max_huge_pages; 824 do_div(size, 100); 825 } 826 pconfig->nr_blocks = (size >> huge_page_shift(h)); 827 } 828 829 return 0; 830 831 bad_val: 832 printk(KERN_ERR "hugetlbfs: Bad value '%s' for mount option '%s'\n", 833 args[0].from, p); 834 return -EINVAL; 835 } 836 837 static int 838 hugetlbfs_fill_super(struct super_block *sb, void *data, int silent) 839 { 840 struct inode * inode; 841 struct dentry * root; 842 int ret; 843 struct hugetlbfs_config config; 844 struct hugetlbfs_sb_info *sbinfo; 845 846 save_mount_options(sb, data); 847 848 config.nr_blocks = -1; /* No limit on size by default */ 849 config.nr_inodes = -1; /* No limit on number of inodes by default */ 850 config.uid = current_fsuid(); 851 config.gid = current_fsgid(); 852 config.mode = 0755; 853 config.hstate = &default_hstate; 854 ret = hugetlbfs_parse_options(data, &config); 855 if (ret) 856 return ret; 857 858 sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL); 859 if (!sbinfo) 860 return -ENOMEM; 861 sb->s_fs_info = sbinfo; 862 sbinfo->hstate = config.hstate; 863 spin_lock_init(&sbinfo->stat_lock); 864 sbinfo->max_blocks = config.nr_blocks; 865 sbinfo->free_blocks = config.nr_blocks; 866 sbinfo->max_inodes = config.nr_inodes; 867 sbinfo->free_inodes = config.nr_inodes; 868 sb->s_maxbytes = MAX_LFS_FILESIZE; 869 sb->s_blocksize = huge_page_size(config.hstate); 870 sb->s_blocksize_bits = huge_page_shift(config.hstate); 871 sb->s_magic = HUGETLBFS_MAGIC; 872 sb->s_op = &hugetlbfs_ops; 873 sb->s_time_gran = 1; 874 inode = hugetlbfs_get_inode(sb, config.uid, config.gid, 875 S_IFDIR | config.mode, 0); 876 if (!inode) 877 goto out_free; 878 879 root = d_alloc_root(inode); 880 if (!root) { 881 iput(inode); 882 goto out_free; 883 } 884 sb->s_root = root; 885 return 0; 886 out_free: 887 kfree(sbinfo); 888 return -ENOMEM; 889 } 890 891 int hugetlb_get_quota(struct address_space *mapping, long delta) 892 { 893 int ret = 0; 894 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); 895 896 if (sbinfo->free_blocks > -1) { 897 spin_lock(&sbinfo->stat_lock); 898 if (sbinfo->free_blocks - delta >= 0) 899 sbinfo->free_blocks -= delta; 900 else 901 ret = -ENOMEM; 902 spin_unlock(&sbinfo->stat_lock); 903 } 904 905 return ret; 906 } 907 908 void hugetlb_put_quota(struct address_space *mapping, long delta) 909 { 910 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); 911 912 if (sbinfo->free_blocks > -1) { 913 spin_lock(&sbinfo->stat_lock); 914 sbinfo->free_blocks += delta; 915 spin_unlock(&sbinfo->stat_lock); 916 } 917 } 918 919 static int hugetlbfs_get_sb(struct file_system_type *fs_type, 920 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 921 { 922 return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super, mnt); 923 } 924 925 static struct file_system_type hugetlbfs_fs_type = { 926 .name = "hugetlbfs", 927 .get_sb = hugetlbfs_get_sb, 928 .kill_sb = kill_litter_super, 929 }; 930 931 static struct vfsmount *hugetlbfs_vfsmount; 932 933 static int can_do_hugetlb_shm(void) 934 { 935 return capable(CAP_IPC_LOCK) || in_group_p(sysctl_hugetlb_shm_group); 936 } 937 938 struct file *hugetlb_file_setup(const char *name, size_t size, int acctflag) 939 { 940 int error = -ENOMEM; 941 int unlock_shm = 0; 942 struct file *file; 943 struct inode *inode; 944 struct dentry *dentry, *root; 945 struct qstr quick_string; 946 struct user_struct *user = current_user(); 947 948 if (!hugetlbfs_vfsmount) 949 return ERR_PTR(-ENOENT); 950 951 if (!can_do_hugetlb_shm()) { 952 if (user_shm_lock(size, user)) { 953 unlock_shm = 1; 954 WARN_ONCE(1, 955 "Using mlock ulimits for SHM_HUGETLB deprecated\n"); 956 } else 957 return ERR_PTR(-EPERM); 958 } 959 960 root = hugetlbfs_vfsmount->mnt_root; 961 quick_string.name = name; 962 quick_string.len = strlen(quick_string.name); 963 quick_string.hash = 0; 964 dentry = d_alloc(root, &quick_string); 965 if (!dentry) 966 goto out_shm_unlock; 967 968 error = -ENOSPC; 969 inode = hugetlbfs_get_inode(root->d_sb, current_fsuid(), 970 current_fsgid(), S_IFREG | S_IRWXUGO, 0); 971 if (!inode) 972 goto out_dentry; 973 974 error = -ENOMEM; 975 if (hugetlb_reserve_pages(inode, 0, 976 size >> huge_page_shift(hstate_inode(inode)), NULL, 977 acctflag)) 978 goto out_inode; 979 980 d_instantiate(dentry, inode); 981 inode->i_size = size; 982 inode->i_nlink = 0; 983 984 error = -ENFILE; 985 file = alloc_file(hugetlbfs_vfsmount, dentry, 986 FMODE_WRITE | FMODE_READ, 987 &hugetlbfs_file_operations); 988 if (!file) 989 goto out_dentry; /* inode is already attached */ 990 ima_counts_get(file); 991 992 return file; 993 994 out_inode: 995 iput(inode); 996 out_dentry: 997 dput(dentry); 998 out_shm_unlock: 999 if (unlock_shm) 1000 user_shm_unlock(size, user); 1001 return ERR_PTR(error); 1002 } 1003 1004 static int __init init_hugetlbfs_fs(void) 1005 { 1006 int error; 1007 struct vfsmount *vfsmount; 1008 1009 error = bdi_init(&hugetlbfs_backing_dev_info); 1010 if (error) 1011 return error; 1012 1013 hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache", 1014 sizeof(struct hugetlbfs_inode_info), 1015 0, 0, init_once); 1016 if (hugetlbfs_inode_cachep == NULL) 1017 goto out2; 1018 1019 error = register_filesystem(&hugetlbfs_fs_type); 1020 if (error) 1021 goto out; 1022 1023 vfsmount = kern_mount(&hugetlbfs_fs_type); 1024 1025 if (!IS_ERR(vfsmount)) { 1026 hugetlbfs_vfsmount = vfsmount; 1027 return 0; 1028 } 1029 1030 error = PTR_ERR(vfsmount); 1031 1032 out: 1033 if (error) 1034 kmem_cache_destroy(hugetlbfs_inode_cachep); 1035 out2: 1036 bdi_destroy(&hugetlbfs_backing_dev_info); 1037 return error; 1038 } 1039 1040 static void __exit exit_hugetlbfs_fs(void) 1041 { 1042 kmem_cache_destroy(hugetlbfs_inode_cachep); 1043 unregister_filesystem(&hugetlbfs_fs_type); 1044 bdi_destroy(&hugetlbfs_backing_dev_info); 1045 } 1046 1047 module_init(init_hugetlbfs_fs) 1048 module_exit(exit_hugetlbfs_fs) 1049 1050 MODULE_LICENSE("GPL"); 1051