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 37static const struct super_operations hugetlbfs_ops; 38static const struct address_space_operations hugetlbfs_aops; 39const struct file_operations hugetlbfs_file_operations; 40static const struct inode_operations hugetlbfs_dir_inode_operations; 41static const struct inode_operations hugetlbfs_inode_operations; 42 43static 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 49int sysctl_hugetlb_shm_group; 50 51enum { 52 Opt_size, Opt_nr_inodes, 53 Opt_mode, Opt_uid, Opt_gid, 54 Opt_pagesize, 55 Opt_err, 56}; 57 58static 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 68static 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 78static 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; 117out: 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 128static unsigned long 129hugetlb_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 161full_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 185static int 186hugetlbfs_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 */ 228static 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 } 308out: 309 *ppos = ((loff_t)index << huge_page_shift(h)) + offset; 310 mutex_unlock(&inode->i_mutex); 311 return retval; 312} 313 314static 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 322static 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 330static 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 338static 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 374static void hugetlbfs_evict_inode(struct inode *inode) 375{ 376 truncate_hugepages(inode, 0); 377 end_writeback(inode); 378} 379 380static inline void 381hugetlb_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 405static 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 423static 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 450static 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_mode = mode; 459 inode->i_uid = uid; 460 inode->i_gid = gid; 461 inode->i_mapping->a_ops = &hugetlbfs_aops; 462 inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info; 463 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; 464 INIT_LIST_HEAD(&inode->i_mapping->private_list); 465 info = HUGETLBFS_I(inode); 466 /* 467 * The policy is initialized here even if we are creating a 468 * private inode because initialization simply creates an 469 * an empty rb tree and calls spin_lock_init(), later when we 470 * call mpol_free_shared_policy() it will just return because 471 * the rb tree will still be empty. 472 */ 473 mpol_shared_policy_init(&info->policy, NULL); 474 switch (mode & S_IFMT) { 475 default: 476 init_special_inode(inode, mode, dev); 477 break; 478 case S_IFREG: 479 inode->i_op = &hugetlbfs_inode_operations; 480 inode->i_fop = &hugetlbfs_file_operations; 481 break; 482 case S_IFDIR: 483 inode->i_op = &hugetlbfs_dir_inode_operations; 484 inode->i_fop = &simple_dir_operations; 485 486 /* directory inodes start off with i_nlink == 2 (for "." entry) */ 487 inc_nlink(inode); 488 break; 489 case S_IFLNK: 490 inode->i_op = &page_symlink_inode_operations; 491 break; 492 } 493 } 494 return inode; 495} 496 497/* 498 * File creation. Allocate an inode, and we're done.. 499 */ 500static int hugetlbfs_mknod(struct inode *dir, 501 struct dentry *dentry, int mode, dev_t dev) 502{ 503 struct inode *inode; 504 int error = -ENOSPC; 505 gid_t gid; 506 507 if (dir->i_mode & S_ISGID) { 508 gid = dir->i_gid; 509 if (S_ISDIR(mode)) 510 mode |= S_ISGID; 511 } else { 512 gid = current_fsgid(); 513 } 514 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), gid, mode, dev); 515 if (inode) { 516 dir->i_ctime = dir->i_mtime = CURRENT_TIME; 517 d_instantiate(dentry, inode); 518 dget(dentry); /* Extra count - pin the dentry in core */ 519 error = 0; 520 } 521 return error; 522} 523 524static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) 525{ 526 int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0); 527 if (!retval) 528 inc_nlink(dir); 529 return retval; 530} 531 532static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) 533{ 534 return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0); 535} 536 537static int hugetlbfs_symlink(struct inode *dir, 538 struct dentry *dentry, const char *symname) 539{ 540 struct inode *inode; 541 int error = -ENOSPC; 542 gid_t gid; 543 544 if (dir->i_mode & S_ISGID) 545 gid = dir->i_gid; 546 else 547 gid = current_fsgid(); 548 549 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), 550 gid, S_IFLNK|S_IRWXUGO, 0); 551 if (inode) { 552 int l = strlen(symname)+1; 553 error = page_symlink(inode, symname, l); 554 if (!error) { 555 d_instantiate(dentry, inode); 556 dget(dentry); 557 } else 558 iput(inode); 559 } 560 dir->i_ctime = dir->i_mtime = CURRENT_TIME; 561 562 return error; 563} 564 565/* 566 * mark the head page dirty 567 */ 568static int hugetlbfs_set_page_dirty(struct page *page) 569{ 570 struct page *head = compound_head(page); 571 572 SetPageDirty(head); 573 return 0; 574} 575 576static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf) 577{ 578 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb); 579 struct hstate *h = hstate_inode(dentry->d_inode); 580 581 buf->f_type = HUGETLBFS_MAGIC; 582 buf->f_bsize = huge_page_size(h); 583 if (sbinfo) { 584 spin_lock(&sbinfo->stat_lock); 585 /* If no limits set, just report 0 for max/free/used 586 * blocks, like simple_statfs() */ 587 if (sbinfo->max_blocks >= 0) { 588 buf->f_blocks = sbinfo->max_blocks; 589 buf->f_bavail = buf->f_bfree = sbinfo->free_blocks; 590 buf->f_files = sbinfo->max_inodes; 591 buf->f_ffree = sbinfo->free_inodes; 592 } 593 spin_unlock(&sbinfo->stat_lock); 594 } 595 buf->f_namelen = NAME_MAX; 596 return 0; 597} 598 599static void hugetlbfs_put_super(struct super_block *sb) 600{ 601 struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb); 602 603 if (sbi) { 604 sb->s_fs_info = NULL; 605 kfree(sbi); 606 } 607} 608 609static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo) 610{ 611 if (sbinfo->free_inodes >= 0) { 612 spin_lock(&sbinfo->stat_lock); 613 if (unlikely(!sbinfo->free_inodes)) { 614 spin_unlock(&sbinfo->stat_lock); 615 return 0; 616 } 617 sbinfo->free_inodes--; 618 spin_unlock(&sbinfo->stat_lock); 619 } 620 621 return 1; 622} 623 624static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo) 625{ 626 if (sbinfo->free_inodes >= 0) { 627 spin_lock(&sbinfo->stat_lock); 628 sbinfo->free_inodes++; 629 spin_unlock(&sbinfo->stat_lock); 630 } 631} 632 633 634static struct kmem_cache *hugetlbfs_inode_cachep; 635 636static struct inode *hugetlbfs_alloc_inode(struct super_block *sb) 637{ 638 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); 639 struct hugetlbfs_inode_info *p; 640 641 if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo))) 642 return NULL; 643 p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL); 644 if (unlikely(!p)) { 645 hugetlbfs_inc_free_inodes(sbinfo); 646 return NULL; 647 } 648 return &p->vfs_inode; 649} 650 651static void hugetlbfs_destroy_inode(struct inode *inode) 652{ 653 hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb)); 654 mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy); 655 kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode)); 656} 657 658static const struct address_space_operations hugetlbfs_aops = { 659 .write_begin = hugetlbfs_write_begin, 660 .write_end = hugetlbfs_write_end, 661 .set_page_dirty = hugetlbfs_set_page_dirty, 662}; 663 664 665static void init_once(void *foo) 666{ 667 struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo; 668 669 inode_init_once(&ei->vfs_inode); 670} 671 672const struct file_operations hugetlbfs_file_operations = { 673 .read = hugetlbfs_read, 674 .mmap = hugetlbfs_file_mmap, 675 .fsync = noop_fsync, 676 .get_unmapped_area = hugetlb_get_unmapped_area, 677}; 678 679static const struct inode_operations hugetlbfs_dir_inode_operations = { 680 .create = hugetlbfs_create, 681 .lookup = simple_lookup, 682 .link = simple_link, 683 .unlink = simple_unlink, 684 .symlink = hugetlbfs_symlink, 685 .mkdir = hugetlbfs_mkdir, 686 .rmdir = simple_rmdir, 687 .mknod = hugetlbfs_mknod, 688 .rename = simple_rename, 689 .setattr = hugetlbfs_setattr, 690}; 691 692static const struct inode_operations hugetlbfs_inode_operations = { 693 .setattr = hugetlbfs_setattr, 694}; 695 696static const struct super_operations hugetlbfs_ops = { 697 .alloc_inode = hugetlbfs_alloc_inode, 698 .destroy_inode = hugetlbfs_destroy_inode, 699 .evict_inode = hugetlbfs_evict_inode, 700 .statfs = hugetlbfs_statfs, 701 .put_super = hugetlbfs_put_super, 702 .show_options = generic_show_options, 703}; 704 705static int 706hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig) 707{ 708 char *p, *rest; 709 substring_t args[MAX_OPT_ARGS]; 710 int option; 711 unsigned long long size = 0; 712 enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = NO_SIZE; 713 714 if (!options) 715 return 0; 716 717 while ((p = strsep(&options, ",")) != NULL) { 718 int token; 719 if (!*p) 720 continue; 721 722 token = match_token(p, tokens, args); 723 switch (token) { 724 case Opt_uid: 725 if (match_int(&args[0], &option)) 726 goto bad_val; 727 pconfig->uid = option; 728 break; 729 730 case Opt_gid: 731 if (match_int(&args[0], &option)) 732 goto bad_val; 733 pconfig->gid = option; 734 break; 735 736 case Opt_mode: 737 if (match_octal(&args[0], &option)) 738 goto bad_val; 739 pconfig->mode = option & 01777U; 740 break; 741 742 case Opt_size: { 743 /* memparse() will accept a K/M/G without a digit */ 744 if (!isdigit(*args[0].from)) 745 goto bad_val; 746 size = memparse(args[0].from, &rest); 747 setsize = SIZE_STD; 748 if (*rest == '%') 749 setsize = SIZE_PERCENT; 750 break; 751 } 752 753 case Opt_nr_inodes: 754 /* memparse() will accept a K/M/G without a digit */ 755 if (!isdigit(*args[0].from)) 756 goto bad_val; 757 pconfig->nr_inodes = memparse(args[0].from, &rest); 758 break; 759 760 case Opt_pagesize: { 761 unsigned long ps; 762 ps = memparse(args[0].from, &rest); 763 pconfig->hstate = size_to_hstate(ps); 764 if (!pconfig->hstate) { 765 printk(KERN_ERR 766 "hugetlbfs: Unsupported page size %lu MB\n", 767 ps >> 20); 768 return -EINVAL; 769 } 770 break; 771 } 772 773 default: 774 printk(KERN_ERR "hugetlbfs: Bad mount option: \"%s\"\n", 775 p); 776 return -EINVAL; 777 break; 778 } 779 } 780 781 /* Do size after hstate is set up */ 782 if (setsize > NO_SIZE) { 783 struct hstate *h = pconfig->hstate; 784 if (setsize == SIZE_PERCENT) { 785 size <<= huge_page_shift(h); 786 size *= h->max_huge_pages; 787 do_div(size, 100); 788 } 789 pconfig->nr_blocks = (size >> huge_page_shift(h)); 790 } 791 792 return 0; 793 794bad_val: 795 printk(KERN_ERR "hugetlbfs: Bad value '%s' for mount option '%s'\n", 796 args[0].from, p); 797 return -EINVAL; 798} 799 800static int 801hugetlbfs_fill_super(struct super_block *sb, void *data, int silent) 802{ 803 struct inode * inode; 804 struct dentry * root; 805 int ret; 806 struct hugetlbfs_config config; 807 struct hugetlbfs_sb_info *sbinfo; 808 809 save_mount_options(sb, data); 810 811 config.nr_blocks = -1; /* No limit on size by default */ 812 config.nr_inodes = -1; /* No limit on number of inodes by default */ 813 config.uid = current_fsuid(); 814 config.gid = current_fsgid(); 815 config.mode = 0755; 816 config.hstate = &default_hstate; 817 ret = hugetlbfs_parse_options(data, &config); 818 if (ret) 819 return ret; 820 821 sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL); 822 if (!sbinfo) 823 return -ENOMEM; 824 sb->s_fs_info = sbinfo; 825 sbinfo->hstate = config.hstate; 826 spin_lock_init(&sbinfo->stat_lock); 827 sbinfo->max_blocks = config.nr_blocks; 828 sbinfo->free_blocks = config.nr_blocks; 829 sbinfo->max_inodes = config.nr_inodes; 830 sbinfo->free_inodes = config.nr_inodes; 831 sb->s_maxbytes = MAX_LFS_FILESIZE; 832 sb->s_blocksize = huge_page_size(config.hstate); 833 sb->s_blocksize_bits = huge_page_shift(config.hstate); 834 sb->s_magic = HUGETLBFS_MAGIC; 835 sb->s_op = &hugetlbfs_ops; 836 sb->s_time_gran = 1; 837 inode = hugetlbfs_get_inode(sb, config.uid, config.gid, 838 S_IFDIR | config.mode, 0); 839 if (!inode) 840 goto out_free; 841 842 root = d_alloc_root(inode); 843 if (!root) { 844 iput(inode); 845 goto out_free; 846 } 847 sb->s_root = root; 848 return 0; 849out_free: 850 kfree(sbinfo); 851 return -ENOMEM; 852} 853 854int hugetlb_get_quota(struct address_space *mapping, long delta) 855{ 856 int ret = 0; 857 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); 858 859 if (sbinfo->free_blocks > -1) { 860 spin_lock(&sbinfo->stat_lock); 861 if (sbinfo->free_blocks - delta >= 0) 862 sbinfo->free_blocks -= delta; 863 else 864 ret = -ENOMEM; 865 spin_unlock(&sbinfo->stat_lock); 866 } 867 868 return ret; 869} 870 871void hugetlb_put_quota(struct address_space *mapping, long delta) 872{ 873 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); 874 875 if (sbinfo->free_blocks > -1) { 876 spin_lock(&sbinfo->stat_lock); 877 sbinfo->free_blocks += delta; 878 spin_unlock(&sbinfo->stat_lock); 879 } 880} 881 882static int hugetlbfs_get_sb(struct file_system_type *fs_type, 883 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 884{ 885 return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super, mnt); 886} 887 888static struct file_system_type hugetlbfs_fs_type = { 889 .name = "hugetlbfs", 890 .get_sb = hugetlbfs_get_sb, 891 .kill_sb = kill_litter_super, 892}; 893 894static struct vfsmount *hugetlbfs_vfsmount; 895 896static int can_do_hugetlb_shm(void) 897{ 898 return capable(CAP_IPC_LOCK) || in_group_p(sysctl_hugetlb_shm_group); 899} 900 901struct file *hugetlb_file_setup(const char *name, size_t size, int acctflag, 902 struct user_struct **user, int creat_flags) 903{ 904 int error = -ENOMEM; 905 struct file *file; 906 struct inode *inode; 907 struct path path; 908 struct dentry *root; 909 struct qstr quick_string; 910 911 *user = NULL; 912 if (!hugetlbfs_vfsmount) 913 return ERR_PTR(-ENOENT); 914 915 if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) { 916 *user = current_user(); 917 if (user_shm_lock(size, *user)) { 918 WARN_ONCE(1, 919 "Using mlock ulimits for SHM_HUGETLB deprecated\n"); 920 } else { 921 *user = NULL; 922 return ERR_PTR(-EPERM); 923 } 924 } 925 926 root = hugetlbfs_vfsmount->mnt_root; 927 quick_string.name = name; 928 quick_string.len = strlen(quick_string.name); 929 quick_string.hash = 0; 930 path.dentry = d_alloc(root, &quick_string); 931 if (!path.dentry) 932 goto out_shm_unlock; 933 934 path.mnt = mntget(hugetlbfs_vfsmount); 935 error = -ENOSPC; 936 inode = hugetlbfs_get_inode(root->d_sb, current_fsuid(), 937 current_fsgid(), S_IFREG | S_IRWXUGO, 0); 938 if (!inode) 939 goto out_dentry; 940 941 error = -ENOMEM; 942 if (hugetlb_reserve_pages(inode, 0, 943 size >> huge_page_shift(hstate_inode(inode)), NULL, 944 acctflag)) 945 goto out_inode; 946 947 d_instantiate(path.dentry, inode); 948 inode->i_size = size; 949 inode->i_nlink = 0; 950 951 error = -ENFILE; 952 file = alloc_file(&path, FMODE_WRITE | FMODE_READ, 953 &hugetlbfs_file_operations); 954 if (!file) 955 goto out_dentry; /* inode is already attached */ 956 957 return file; 958 959out_inode: 960 iput(inode); 961out_dentry: 962 path_put(&path); 963out_shm_unlock: 964 if (*user) { 965 user_shm_unlock(size, *user); 966 *user = NULL; 967 } 968 return ERR_PTR(error); 969} 970 971static int __init init_hugetlbfs_fs(void) 972{ 973 int error; 974 struct vfsmount *vfsmount; 975 976 error = bdi_init(&hugetlbfs_backing_dev_info); 977 if (error) 978 return error; 979 980 hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache", 981 sizeof(struct hugetlbfs_inode_info), 982 0, 0, init_once); 983 if (hugetlbfs_inode_cachep == NULL) 984 goto out2; 985 986 error = register_filesystem(&hugetlbfs_fs_type); 987 if (error) 988 goto out; 989 990 vfsmount = kern_mount(&hugetlbfs_fs_type); 991 992 if (!IS_ERR(vfsmount)) { 993 hugetlbfs_vfsmount = vfsmount; 994 return 0; 995 } 996 997 error = PTR_ERR(vfsmount); 998 999 out: 1000 if (error) 1001 kmem_cache_destroy(hugetlbfs_inode_cachep); 1002 out2: 1003 bdi_destroy(&hugetlbfs_backing_dev_info); 1004 return error; 1005} 1006 1007static void __exit exit_hugetlbfs_fs(void) 1008{ 1009 kmem_cache_destroy(hugetlbfs_inode_cachep); 1010 unregister_filesystem(&hugetlbfs_fs_type); 1011 bdi_destroy(&hugetlbfs_backing_dev_info); 1012} 1013 1014module_init(init_hugetlbfs_fs) 1015module_exit(exit_hugetlbfs_fs) 1016 1017MODULE_LICENSE("GPL"); 1018