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 35 #include <asm/uaccess.h> 36 37 static const struct super_operations hugetlbfs_ops; 38 static const struct address_space_operations hugetlbfs_aops; 39 const struct file_operations hugetlbfs_file_operations; 40 static const struct inode_operations hugetlbfs_dir_inode_operations; 41 static const struct inode_operations hugetlbfs_inode_operations; 42 43 static struct backing_dev_info hugetlbfs_backing_dev_info = { 44 .name = "hugetlbfs", 45 .ra_pages = 0, /* No readahead */ 46 .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK, 47 }; 48 49 int sysctl_hugetlb_shm_group; 50 51 enum { 52 Opt_size, Opt_nr_inodes, 53 Opt_mode, Opt_uid, Opt_gid, 54 Opt_pagesize, 55 Opt_err, 56 }; 57 58 static const match_table_t tokens = { 59 {Opt_size, "size=%s"}, 60 {Opt_nr_inodes, "nr_inodes=%s"}, 61 {Opt_mode, "mode=%o"}, 62 {Opt_uid, "uid=%u"}, 63 {Opt_gid, "gid=%u"}, 64 {Opt_pagesize, "pagesize=%s"}, 65 {Opt_err, NULL}, 66 }; 67 68 static void huge_pagevec_release(struct pagevec *pvec) 69 { 70 int i; 71 72 for (i = 0; i < pagevec_count(pvec); ++i) 73 put_page(pvec->pages[i]); 74 75 pagevec_reinit(pvec); 76 } 77 78 static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma) 79 { 80 struct inode *inode = file->f_path.dentry->d_inode; 81 loff_t len, vma_len; 82 int ret; 83 struct hstate *h = hstate_file(file); 84 85 /* 86 * vma address alignment (but not the pgoff alignment) has 87 * already been checked by prepare_hugepage_range. If you add 88 * any error returns here, do so after setting VM_HUGETLB, so 89 * is_vm_hugetlb_page tests below unmap_region go the right 90 * way when do_mmap_pgoff unwinds (may be important on powerpc 91 * and ia64). 92 */ 93 vma->vm_flags |= VM_HUGETLB | VM_RESERVED; 94 vma->vm_ops = &hugetlb_vm_ops; 95 96 if (vma->vm_pgoff & ~(huge_page_mask(h) >> PAGE_SHIFT)) 97 return -EINVAL; 98 99 vma_len = (loff_t)(vma->vm_end - vma->vm_start); 100 101 mutex_lock(&inode->i_mutex); 102 file_accessed(file); 103 104 ret = -ENOMEM; 105 len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); 106 107 if (hugetlb_reserve_pages(inode, 108 vma->vm_pgoff >> huge_page_order(h), 109 len >> huge_page_shift(h), vma, 110 vma->vm_flags)) 111 goto out; 112 113 ret = 0; 114 hugetlb_prefault_arch_hook(vma->vm_mm); 115 if (vma->vm_flags & VM_WRITE && inode->i_size < len) 116 inode->i_size = len; 117 out: 118 mutex_unlock(&inode->i_mutex); 119 120 return ret; 121 } 122 123 /* 124 * Called under down_write(mmap_sem). 125 */ 126 127 #ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA 128 static unsigned long 129 hugetlb_get_unmapped_area(struct file *file, unsigned long addr, 130 unsigned long len, unsigned long pgoff, unsigned long flags) 131 { 132 struct mm_struct *mm = current->mm; 133 struct vm_area_struct *vma; 134 unsigned long start_addr; 135 struct hstate *h = hstate_file(file); 136 137 if (len & ~huge_page_mask(h)) 138 return -EINVAL; 139 if (len > TASK_SIZE) 140 return -ENOMEM; 141 142 if (flags & MAP_FIXED) { 143 if (prepare_hugepage_range(file, addr, len)) 144 return -EINVAL; 145 return addr; 146 } 147 148 if (addr) { 149 addr = ALIGN(addr, huge_page_size(h)); 150 vma = find_vma(mm, addr); 151 if (TASK_SIZE - len >= addr && 152 (!vma || addr + len <= vma->vm_start)) 153 return addr; 154 } 155 156 start_addr = mm->free_area_cache; 157 158 if (len <= mm->cached_hole_size) 159 start_addr = TASK_UNMAPPED_BASE; 160 161 full_search: 162 addr = ALIGN(start_addr, huge_page_size(h)); 163 164 for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { 165 /* At this point: (!vma || addr < vma->vm_end). */ 166 if (TASK_SIZE - len < addr) { 167 /* 168 * Start a new search - just in case we missed 169 * some holes. 170 */ 171 if (start_addr != TASK_UNMAPPED_BASE) { 172 start_addr = TASK_UNMAPPED_BASE; 173 goto full_search; 174 } 175 return -ENOMEM; 176 } 177 178 if (!vma || addr + len <= vma->vm_start) 179 return addr; 180 addr = ALIGN(vma->vm_end, huge_page_size(h)); 181 } 182 } 183 #endif 184 185 static int 186 hugetlbfs_read_actor(struct page *page, unsigned long offset, 187 char __user *buf, unsigned long count, 188 unsigned long size) 189 { 190 char *kaddr; 191 unsigned long left, copied = 0; 192 int i, chunksize; 193 194 if (size > count) 195 size = count; 196 197 /* Find which 4k chunk and offset with in that chunk */ 198 i = offset >> PAGE_CACHE_SHIFT; 199 offset = offset & ~PAGE_CACHE_MASK; 200 201 while (size) { 202 chunksize = PAGE_CACHE_SIZE; 203 if (offset) 204 chunksize -= offset; 205 if (chunksize > size) 206 chunksize = size; 207 kaddr = kmap(&page[i]); 208 left = __copy_to_user(buf, kaddr + offset, chunksize); 209 kunmap(&page[i]); 210 if (left) { 211 copied += (chunksize - left); 212 break; 213 } 214 offset = 0; 215 size -= chunksize; 216 buf += chunksize; 217 copied += chunksize; 218 i++; 219 } 220 return copied ? copied : -EFAULT; 221 } 222 223 /* 224 * Support for read() - Find the page attached to f_mapping and copy out the 225 * data. Its *very* similar to do_generic_mapping_read(), we can't use that 226 * since it has PAGE_CACHE_SIZE assumptions. 227 */ 228 static ssize_t hugetlbfs_read(struct file *filp, char __user *buf, 229 size_t len, loff_t *ppos) 230 { 231 struct hstate *h = hstate_file(filp); 232 struct address_space *mapping = filp->f_mapping; 233 struct inode *inode = mapping->host; 234 unsigned long index = *ppos >> huge_page_shift(h); 235 unsigned long offset = *ppos & ~huge_page_mask(h); 236 unsigned long end_index; 237 loff_t isize; 238 ssize_t retval = 0; 239 240 mutex_lock(&inode->i_mutex); 241 242 /* validate length */ 243 if (len == 0) 244 goto out; 245 246 isize = i_size_read(inode); 247 if (!isize) 248 goto out; 249 250 end_index = (isize - 1) >> huge_page_shift(h); 251 for (;;) { 252 struct page *page; 253 unsigned long nr, ret; 254 int ra; 255 256 /* nr is the maximum number of bytes to copy from this page */ 257 nr = huge_page_size(h); 258 if (index >= end_index) { 259 if (index > end_index) 260 goto out; 261 nr = ((isize - 1) & ~huge_page_mask(h)) + 1; 262 if (nr <= offset) { 263 goto out; 264 } 265 } 266 nr = nr - offset; 267 268 /* Find the page */ 269 page = find_get_page(mapping, index); 270 if (unlikely(page == NULL)) { 271 /* 272 * We have a HOLE, zero out the user-buffer for the 273 * length of the hole or request. 274 */ 275 ret = len < nr ? len : nr; 276 if (clear_user(buf, ret)) 277 ra = -EFAULT; 278 else 279 ra = 0; 280 } else { 281 /* 282 * We have the page, copy it to user space buffer. 283 */ 284 ra = hugetlbfs_read_actor(page, offset, buf, len, nr); 285 ret = ra; 286 } 287 if (ra < 0) { 288 if (retval == 0) 289 retval = ra; 290 if (page) 291 page_cache_release(page); 292 goto out; 293 } 294 295 offset += ret; 296 retval += ret; 297 len -= ret; 298 index += offset >> huge_page_shift(h); 299 offset &= ~huge_page_mask(h); 300 301 if (page) 302 page_cache_release(page); 303 304 /* short read or no more work */ 305 if ((ret != nr) || (len == 0)) 306 break; 307 } 308 out: 309 *ppos = ((loff_t)index << huge_page_shift(h)) + offset; 310 mutex_unlock(&inode->i_mutex); 311 return retval; 312 } 313 314 static int hugetlbfs_write_begin(struct file *file, 315 struct address_space *mapping, 316 loff_t pos, unsigned len, unsigned flags, 317 struct page **pagep, void **fsdata) 318 { 319 return -EINVAL; 320 } 321 322 static int hugetlbfs_write_end(struct file *file, struct address_space *mapping, 323 loff_t pos, unsigned len, unsigned copied, 324 struct page *page, void *fsdata) 325 { 326 BUG(); 327 return -EINVAL; 328 } 329 330 static void truncate_huge_page(struct page *page) 331 { 332 cancel_dirty_page(page, /* No IO accounting for huge pages? */0); 333 ClearPageUptodate(page); 334 remove_from_page_cache(page); 335 put_page(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_delete_inode(struct inode *inode) 375 { 376 truncate_hugepages(inode, 0); 377 clear_inode(inode); 378 } 379 380 static void hugetlbfs_forget_inode(struct inode *inode) __releases(inode_lock) 381 { 382 if (generic_detach_inode(inode)) { 383 truncate_hugepages(inode, 0); 384 clear_inode(inode); 385 destroy_inode(inode); 386 } 387 } 388 389 static void hugetlbfs_drop_inode(struct inode *inode) 390 { 391 if (!inode->i_nlink) 392 generic_delete_inode(inode); 393 else 394 hugetlbfs_forget_inode(inode); 395 } 396 397 static inline void 398 hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff) 399 { 400 struct vm_area_struct *vma; 401 struct prio_tree_iter iter; 402 403 vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) { 404 unsigned long v_offset; 405 406 /* 407 * Can the expression below overflow on 32-bit arches? 408 * No, because the prio_tree returns us only those vmas 409 * which overlap the truncated area starting at pgoff, 410 * and no vma on a 32-bit arch can span beyond the 4GB. 411 */ 412 if (vma->vm_pgoff < pgoff) 413 v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT; 414 else 415 v_offset = 0; 416 417 __unmap_hugepage_range(vma, 418 vma->vm_start + v_offset, vma->vm_end, NULL); 419 } 420 } 421 422 static int hugetlb_vmtruncate(struct inode *inode, loff_t offset) 423 { 424 pgoff_t pgoff; 425 struct address_space *mapping = inode->i_mapping; 426 struct hstate *h = hstate_inode(inode); 427 428 BUG_ON(offset & ~huge_page_mask(h)); 429 pgoff = offset >> PAGE_SHIFT; 430 431 i_size_write(inode, offset); 432 spin_lock(&mapping->i_mmap_lock); 433 if (!prio_tree_empty(&mapping->i_mmap)) 434 hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff); 435 spin_unlock(&mapping->i_mmap_lock); 436 truncate_hugepages(inode, offset); 437 return 0; 438 } 439 440 static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr) 441 { 442 struct inode *inode = dentry->d_inode; 443 struct hstate *h = hstate_inode(inode); 444 int error; 445 unsigned int ia_valid = attr->ia_valid; 446 447 BUG_ON(!inode); 448 449 error = inode_change_ok(inode, attr); 450 if (error) 451 goto out; 452 453 if (ia_valid & ATTR_SIZE) { 454 error = -EINVAL; 455 if (!(attr->ia_size & ~huge_page_mask(h))) 456 error = hugetlb_vmtruncate(inode, attr->ia_size); 457 if (error) 458 goto out; 459 attr->ia_valid &= ~ATTR_SIZE; 460 } 461 error = inode_setattr(inode, attr); 462 out: 463 return error; 464 } 465 466 static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid, 467 gid_t gid, int mode, dev_t dev) 468 { 469 struct inode *inode; 470 471 inode = new_inode(sb); 472 if (inode) { 473 struct hugetlbfs_inode_info *info; 474 inode->i_mode = mode; 475 inode->i_uid = uid; 476 inode->i_gid = gid; 477 inode->i_mapping->a_ops = &hugetlbfs_aops; 478 inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info; 479 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; 480 INIT_LIST_HEAD(&inode->i_mapping->private_list); 481 info = HUGETLBFS_I(inode); 482 /* 483 * The policy is initialized here even if we are creating a 484 * private inode because initialization simply creates an 485 * an empty rb tree and calls spin_lock_init(), later when we 486 * call mpol_free_shared_policy() it will just return because 487 * the rb tree will still be empty. 488 */ 489 mpol_shared_policy_init(&info->policy, NULL); 490 switch (mode & S_IFMT) { 491 default: 492 init_special_inode(inode, mode, dev); 493 break; 494 case S_IFREG: 495 inode->i_op = &hugetlbfs_inode_operations; 496 inode->i_fop = &hugetlbfs_file_operations; 497 break; 498 case S_IFDIR: 499 inode->i_op = &hugetlbfs_dir_inode_operations; 500 inode->i_fop = &simple_dir_operations; 501 502 /* directory inodes start off with i_nlink == 2 (for "." entry) */ 503 inc_nlink(inode); 504 break; 505 case S_IFLNK: 506 inode->i_op = &page_symlink_inode_operations; 507 break; 508 } 509 } 510 return inode; 511 } 512 513 /* 514 * File creation. Allocate an inode, and we're done.. 515 */ 516 static int hugetlbfs_mknod(struct inode *dir, 517 struct dentry *dentry, int mode, dev_t dev) 518 { 519 struct inode *inode; 520 int error = -ENOSPC; 521 gid_t gid; 522 523 if (dir->i_mode & S_ISGID) { 524 gid = dir->i_gid; 525 if (S_ISDIR(mode)) 526 mode |= S_ISGID; 527 } else { 528 gid = current_fsgid(); 529 } 530 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), gid, mode, dev); 531 if (inode) { 532 dir->i_ctime = dir->i_mtime = CURRENT_TIME; 533 d_instantiate(dentry, inode); 534 dget(dentry); /* Extra count - pin the dentry in core */ 535 error = 0; 536 } 537 return error; 538 } 539 540 static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) 541 { 542 int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0); 543 if (!retval) 544 inc_nlink(dir); 545 return retval; 546 } 547 548 static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) 549 { 550 return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0); 551 } 552 553 static int hugetlbfs_symlink(struct inode *dir, 554 struct dentry *dentry, const char *symname) 555 { 556 struct inode *inode; 557 int error = -ENOSPC; 558 gid_t gid; 559 560 if (dir->i_mode & S_ISGID) 561 gid = dir->i_gid; 562 else 563 gid = current_fsgid(); 564 565 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), 566 gid, S_IFLNK|S_IRWXUGO, 0); 567 if (inode) { 568 int l = strlen(symname)+1; 569 error = page_symlink(inode, symname, l); 570 if (!error) { 571 d_instantiate(dentry, inode); 572 dget(dentry); 573 } else 574 iput(inode); 575 } 576 dir->i_ctime = dir->i_mtime = CURRENT_TIME; 577 578 return error; 579 } 580 581 /* 582 * mark the head page dirty 583 */ 584 static int hugetlbfs_set_page_dirty(struct page *page) 585 { 586 struct page *head = compound_head(page); 587 588 SetPageDirty(head); 589 return 0; 590 } 591 592 static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf) 593 { 594 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb); 595 struct hstate *h = hstate_inode(dentry->d_inode); 596 597 buf->f_type = HUGETLBFS_MAGIC; 598 buf->f_bsize = huge_page_size(h); 599 if (sbinfo) { 600 spin_lock(&sbinfo->stat_lock); 601 /* If no limits set, just report 0 for max/free/used 602 * blocks, like simple_statfs() */ 603 if (sbinfo->max_blocks >= 0) { 604 buf->f_blocks = sbinfo->max_blocks; 605 buf->f_bavail = buf->f_bfree = sbinfo->free_blocks; 606 buf->f_files = sbinfo->max_inodes; 607 buf->f_ffree = sbinfo->free_inodes; 608 } 609 spin_unlock(&sbinfo->stat_lock); 610 } 611 buf->f_namelen = NAME_MAX; 612 return 0; 613 } 614 615 static void hugetlbfs_put_super(struct super_block *sb) 616 { 617 struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb); 618 619 if (sbi) { 620 sb->s_fs_info = NULL; 621 kfree(sbi); 622 } 623 } 624 625 static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo) 626 { 627 if (sbinfo->free_inodes >= 0) { 628 spin_lock(&sbinfo->stat_lock); 629 if (unlikely(!sbinfo->free_inodes)) { 630 spin_unlock(&sbinfo->stat_lock); 631 return 0; 632 } 633 sbinfo->free_inodes--; 634 spin_unlock(&sbinfo->stat_lock); 635 } 636 637 return 1; 638 } 639 640 static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo) 641 { 642 if (sbinfo->free_inodes >= 0) { 643 spin_lock(&sbinfo->stat_lock); 644 sbinfo->free_inodes++; 645 spin_unlock(&sbinfo->stat_lock); 646 } 647 } 648 649 650 static struct kmem_cache *hugetlbfs_inode_cachep; 651 652 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb) 653 { 654 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); 655 struct hugetlbfs_inode_info *p; 656 657 if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo))) 658 return NULL; 659 p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL); 660 if (unlikely(!p)) { 661 hugetlbfs_inc_free_inodes(sbinfo); 662 return NULL; 663 } 664 return &p->vfs_inode; 665 } 666 667 static void hugetlbfs_destroy_inode(struct inode *inode) 668 { 669 hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb)); 670 mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy); 671 kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode)); 672 } 673 674 static const struct address_space_operations hugetlbfs_aops = { 675 .write_begin = hugetlbfs_write_begin, 676 .write_end = hugetlbfs_write_end, 677 .set_page_dirty = hugetlbfs_set_page_dirty, 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 = simple_sync_file, 692 .get_unmapped_area = hugetlb_get_unmapped_area, 693 }; 694 695 static const struct inode_operations hugetlbfs_dir_inode_operations = { 696 .create = hugetlbfs_create, 697 .lookup = simple_lookup, 698 .link = simple_link, 699 .unlink = simple_unlink, 700 .symlink = hugetlbfs_symlink, 701 .mkdir = hugetlbfs_mkdir, 702 .rmdir = simple_rmdir, 703 .mknod = hugetlbfs_mknod, 704 .rename = simple_rename, 705 .setattr = hugetlbfs_setattr, 706 }; 707 708 static const struct inode_operations hugetlbfs_inode_operations = { 709 .setattr = hugetlbfs_setattr, 710 }; 711 712 static const struct super_operations hugetlbfs_ops = { 713 .alloc_inode = hugetlbfs_alloc_inode, 714 .destroy_inode = hugetlbfs_destroy_inode, 715 .statfs = hugetlbfs_statfs, 716 .delete_inode = hugetlbfs_delete_inode, 717 .drop_inode = hugetlbfs_drop_inode, 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 int hugetlbfs_get_sb(struct file_system_type *fs_type, 900 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 901 { 902 return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super, mnt); 903 } 904 905 static struct file_system_type hugetlbfs_fs_type = { 906 .name = "hugetlbfs", 907 .get_sb = hugetlbfs_get_sb, 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 WARN_ONCE(1, 936 "Using mlock ulimits for SHM_HUGETLB deprecated\n"); 937 } else { 938 *user = NULL; 939 return ERR_PTR(-EPERM); 940 } 941 } 942 943 root = hugetlbfs_vfsmount->mnt_root; 944 quick_string.name = name; 945 quick_string.len = strlen(quick_string.name); 946 quick_string.hash = 0; 947 path.dentry = d_alloc(root, &quick_string); 948 if (!path.dentry) 949 goto out_shm_unlock; 950 951 path.mnt = mntget(hugetlbfs_vfsmount); 952 error = -ENOSPC; 953 inode = hugetlbfs_get_inode(root->d_sb, current_fsuid(), 954 current_fsgid(), S_IFREG | S_IRWXUGO, 0); 955 if (!inode) 956 goto out_dentry; 957 958 error = -ENOMEM; 959 if (hugetlb_reserve_pages(inode, 0, 960 size >> huge_page_shift(hstate_inode(inode)), NULL, 961 acctflag)) 962 goto out_inode; 963 964 d_instantiate(path.dentry, inode); 965 inode->i_size = size; 966 inode->i_nlink = 0; 967 968 error = -ENFILE; 969 file = alloc_file(&path, FMODE_WRITE | FMODE_READ, 970 &hugetlbfs_file_operations); 971 if (!file) 972 goto out_dentry; /* inode is already attached */ 973 974 return file; 975 976 out_inode: 977 iput(inode); 978 out_dentry: 979 path_put(&path); 980 out_shm_unlock: 981 if (*user) { 982 user_shm_unlock(size, *user); 983 *user = NULL; 984 } 985 return ERR_PTR(error); 986 } 987 988 static int __init init_hugetlbfs_fs(void) 989 { 990 int error; 991 struct vfsmount *vfsmount; 992 993 error = bdi_init(&hugetlbfs_backing_dev_info); 994 if (error) 995 return error; 996 997 hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache", 998 sizeof(struct hugetlbfs_inode_info), 999 0, 0, init_once); 1000 if (hugetlbfs_inode_cachep == NULL) 1001 goto out2; 1002 1003 error = register_filesystem(&hugetlbfs_fs_type); 1004 if (error) 1005 goto out; 1006 1007 vfsmount = kern_mount(&hugetlbfs_fs_type); 1008 1009 if (!IS_ERR(vfsmount)) { 1010 hugetlbfs_vfsmount = vfsmount; 1011 return 0; 1012 } 1013 1014 error = PTR_ERR(vfsmount); 1015 1016 out: 1017 if (error) 1018 kmem_cache_destroy(hugetlbfs_inode_cachep); 1019 out2: 1020 bdi_destroy(&hugetlbfs_backing_dev_info); 1021 return error; 1022 } 1023 1024 static void __exit exit_hugetlbfs_fs(void) 1025 { 1026 kmem_cache_destroy(hugetlbfs_inode_cachep); 1027 unregister_filesystem(&hugetlbfs_fs_type); 1028 bdi_destroy(&hugetlbfs_backing_dev_info); 1029 } 1030 1031 module_init(init_hugetlbfs_fs) 1032 module_exit(exit_hugetlbfs_fs) 1033 1034 MODULE_LICENSE("GPL"); 1035