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10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/thread_info.h>
13#include <asm/current.h>
14#include <linux/sched/signal.h>
15#include <linux/falloc.h>
16#include <linux/fs.h>
17#include <linux/mount.h>
18#include <linux/file.h>
19#include <linux/kernel.h>
20#include <linux/writeback.h>
21#include <linux/pagemap.h>
22#include <linux/highmem.h>
23#include <linux/init.h>
24#include <linux/string.h>
25#include <linux/capability.h>
26#include <linux/ctype.h>
27#include <linux/backing-dev.h>
28#include <linux/hugetlb.h>
29#include <linux/pagevec.h>
30#include <linux/parser.h>
31#include <linux/mman.h>
32#include <linux/slab.h>
33#include <linux/dnotify.h>
34#include <linux/statfs.h>
35#include <linux/security.h>
36#include <linux/magic.h>
37#include <linux/migrate.h>
38#include <linux/uio.h>
39
40#include <linux/uaccess.h>
41
42static const struct super_operations hugetlbfs_ops;
43static const struct address_space_operations hugetlbfs_aops;
44const struct file_operations hugetlbfs_file_operations;
45static const struct inode_operations hugetlbfs_dir_inode_operations;
46static const struct inode_operations hugetlbfs_inode_operations;
47
48struct hugetlbfs_config {
49 struct hstate *hstate;
50 long max_hpages;
51 long nr_inodes;
52 long min_hpages;
53 kuid_t uid;
54 kgid_t gid;
55 umode_t mode;
56};
57
58int sysctl_hugetlb_shm_group;
59
60enum {
61 Opt_size, Opt_nr_inodes,
62 Opt_mode, Opt_uid, Opt_gid,
63 Opt_pagesize, Opt_min_size,
64 Opt_err,
65};
66
67static const match_table_t tokens = {
68 {Opt_size, "size=%s"},
69 {Opt_nr_inodes, "nr_inodes=%s"},
70 {Opt_mode, "mode=%o"},
71 {Opt_uid, "uid=%u"},
72 {Opt_gid, "gid=%u"},
73 {Opt_pagesize, "pagesize=%s"},
74 {Opt_min_size, "min_size=%s"},
75 {Opt_err, NULL},
76};
77
78#ifdef CONFIG_NUMA
79static inline void hugetlb_set_vma_policy(struct vm_area_struct *vma,
80 struct inode *inode, pgoff_t index)
81{
82 vma->vm_policy = mpol_shared_policy_lookup(&HUGETLBFS_I(inode)->policy,
83 index);
84}
85
86static inline void hugetlb_drop_vma_policy(struct vm_area_struct *vma)
87{
88 mpol_cond_put(vma->vm_policy);
89}
90#else
91static inline void hugetlb_set_vma_policy(struct vm_area_struct *vma,
92 struct inode *inode, pgoff_t index)
93{
94}
95
96static inline void hugetlb_drop_vma_policy(struct vm_area_struct *vma)
97{
98}
99#endif
100
101static void huge_pagevec_release(struct pagevec *pvec)
102{
103 int i;
104
105 for (i = 0; i < pagevec_count(pvec); ++i)
106 put_page(pvec->pages[i]);
107
108 pagevec_reinit(pvec);
109}
110
111
112
113
114
115
116
117
118#define PGOFF_LOFFT_MAX \
119 (((1UL << (PAGE_SHIFT + 1)) - 1) << (BITS_PER_LONG - (PAGE_SHIFT + 1)))
120
121static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
122{
123 struct inode *inode = file_inode(file);
124 loff_t len, vma_len;
125 int ret;
126 struct hstate *h = hstate_file(file);
127
128
129
130
131
132
133
134
135
136 vma->vm_flags |= VM_HUGETLB | VM_DONTEXPAND;
137 vma->vm_ops = &hugetlb_vm_ops;
138
139
140
141
142
143 if (vma->vm_pgoff & PGOFF_LOFFT_MAX)
144 return -EINVAL;
145
146
147 if (vma->vm_pgoff & (~huge_page_mask(h) >> PAGE_SHIFT))
148 return -EINVAL;
149
150 vma_len = (loff_t)(vma->vm_end - vma->vm_start);
151 len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
152
153 if (len < vma_len)
154 return -EINVAL;
155
156 inode_lock(inode);
157 file_accessed(file);
158
159 ret = -ENOMEM;
160 if (hugetlb_reserve_pages(inode,
161 vma->vm_pgoff >> huge_page_order(h),
162 len >> huge_page_shift(h), vma,
163 vma->vm_flags))
164 goto out;
165
166 ret = 0;
167 if (vma->vm_flags & VM_WRITE && inode->i_size < len)
168 i_size_write(inode, len);
169out:
170 inode_unlock(inode);
171
172 return ret;
173}
174
175
176
177
178
179#ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
180static unsigned long
181hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
182 unsigned long len, unsigned long pgoff, unsigned long flags)
183{
184 struct mm_struct *mm = current->mm;
185 struct vm_area_struct *vma;
186 struct hstate *h = hstate_file(file);
187 struct vm_unmapped_area_info info;
188
189 if (len & ~huge_page_mask(h))
190 return -EINVAL;
191 if (len > TASK_SIZE)
192 return -ENOMEM;
193
194 if (flags & MAP_FIXED) {
195 if (prepare_hugepage_range(file, addr, len))
196 return -EINVAL;
197 return addr;
198 }
199
200 if (addr) {
201 addr = ALIGN(addr, huge_page_size(h));
202 vma = find_vma(mm, addr);
203 if (TASK_SIZE - len >= addr &&
204 (!vma || addr + len <= vm_start_gap(vma)))
205 return addr;
206 }
207
208 info.flags = 0;
209 info.length = len;
210 info.low_limit = TASK_UNMAPPED_BASE;
211 info.high_limit = TASK_SIZE;
212 info.align_mask = PAGE_MASK & ~huge_page_mask(h);
213 info.align_offset = 0;
214 return vm_unmapped_area(&info);
215}
216#endif
217
218static size_t
219hugetlbfs_read_actor(struct page *page, unsigned long offset,
220 struct iov_iter *to, unsigned long size)
221{
222 size_t copied = 0;
223 int i, chunksize;
224
225
226 i = offset >> PAGE_SHIFT;
227 offset = offset & ~PAGE_MASK;
228
229 while (size) {
230 size_t n;
231 chunksize = PAGE_SIZE;
232 if (offset)
233 chunksize -= offset;
234 if (chunksize > size)
235 chunksize = size;
236 n = copy_page_to_iter(&page[i], offset, chunksize, to);
237 copied += n;
238 if (n != chunksize)
239 return copied;
240 offset = 0;
241 size -= chunksize;
242 i++;
243 }
244 return copied;
245}
246
247
248
249
250
251
252static ssize_t hugetlbfs_read_iter(struct kiocb *iocb, struct iov_iter *to)
253{
254 struct file *file = iocb->ki_filp;
255 struct hstate *h = hstate_file(file);
256 struct address_space *mapping = file->f_mapping;
257 struct inode *inode = mapping->host;
258 unsigned long index = iocb->ki_pos >> huge_page_shift(h);
259 unsigned long offset = iocb->ki_pos & ~huge_page_mask(h);
260 unsigned long end_index;
261 loff_t isize;
262 ssize_t retval = 0;
263
264 while (iov_iter_count(to)) {
265 struct page *page;
266 size_t nr, copied;
267
268
269 nr = huge_page_size(h);
270 isize = i_size_read(inode);
271 if (!isize)
272 break;
273 end_index = (isize - 1) >> huge_page_shift(h);
274 if (index > end_index)
275 break;
276 if (index == end_index) {
277 nr = ((isize - 1) & ~huge_page_mask(h)) + 1;
278 if (nr <= offset)
279 break;
280 }
281 nr = nr - offset;
282
283
284 page = find_lock_page(mapping, index);
285 if (unlikely(page == NULL)) {
286
287
288
289
290 copied = iov_iter_zero(nr, to);
291 } else {
292 unlock_page(page);
293
294
295
296
297 copied = hugetlbfs_read_actor(page, offset, to, nr);
298 put_page(page);
299 }
300 offset += copied;
301 retval += copied;
302 if (copied != nr && iov_iter_count(to)) {
303 if (!retval)
304 retval = -EFAULT;
305 break;
306 }
307 index += offset >> huge_page_shift(h);
308 offset &= ~huge_page_mask(h);
309 }
310 iocb->ki_pos = ((loff_t)index << huge_page_shift(h)) + offset;
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 remove_huge_page(struct page *page)
331{
332 ClearPageDirty(page);
333 ClearPageUptodate(page);
334 delete_from_page_cache(page);
335}
336
337static void
338hugetlb_vmdelete_list(struct rb_root_cached *root, pgoff_t start, pgoff_t end)
339{
340 struct vm_area_struct *vma;
341
342
343
344
345
346 vma_interval_tree_foreach(vma, root, start, end ? end : ULONG_MAX) {
347 unsigned long v_offset;
348 unsigned long v_end;
349
350
351
352
353
354
355
356 if (vma->vm_pgoff < start)
357 v_offset = (start - vma->vm_pgoff) << PAGE_SHIFT;
358 else
359 v_offset = 0;
360
361 if (!end)
362 v_end = vma->vm_end;
363 else {
364 v_end = ((end - vma->vm_pgoff) << PAGE_SHIFT)
365 + vma->vm_start;
366 if (v_end > vma->vm_end)
367 v_end = vma->vm_end;
368 }
369
370 unmap_hugepage_range(vma, vma->vm_start + v_offset, v_end,
371 NULL);
372 }
373}
374
375
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379
380
381
382
383
384
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386
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388
389
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391
392
393
394
395
396static void remove_inode_hugepages(struct inode *inode, loff_t lstart,
397 loff_t lend)
398{
399 struct hstate *h = hstate_inode(inode);
400 struct address_space *mapping = &inode->i_data;
401 const pgoff_t start = lstart >> huge_page_shift(h);
402 const pgoff_t end = lend >> huge_page_shift(h);
403 struct vm_area_struct pseudo_vma;
404 struct pagevec pvec;
405 pgoff_t next, index;
406 int i, freed = 0;
407 bool truncate_op = (lend == LLONG_MAX);
408
409 memset(&pseudo_vma, 0, sizeof(struct vm_area_struct));
410 pseudo_vma.vm_flags = (VM_HUGETLB | VM_MAYSHARE | VM_SHARED);
411 pagevec_init(&pvec);
412 next = start;
413 while (next < end) {
414
415
416
417 if (!pagevec_lookup_range(&pvec, mapping, &next, end - 1))
418 break;
419
420 for (i = 0; i < pagevec_count(&pvec); ++i) {
421 struct page *page = pvec.pages[i];
422 u32 hash;
423
424 index = page->index;
425 hash = hugetlb_fault_mutex_hash(h, current->mm,
426 &pseudo_vma,
427 mapping, index, 0);
428 mutex_lock(&hugetlb_fault_mutex_table[hash]);
429
430
431
432
433
434
435
436
437
438
439 if (unlikely(page_mapped(page))) {
440 BUG_ON(truncate_op);
441
442 i_mmap_lock_write(mapping);
443 hugetlb_vmdelete_list(&mapping->i_mmap,
444 index * pages_per_huge_page(h),
445 (index + 1) * pages_per_huge_page(h));
446 i_mmap_unlock_write(mapping);
447 }
448
449 lock_page(page);
450
451
452
453
454
455
456
457
458
459 VM_BUG_ON(PagePrivate(page));
460 remove_huge_page(page);
461 freed++;
462 if (!truncate_op) {
463 if (unlikely(hugetlb_unreserve_pages(inode,
464 index, index + 1, 1)))
465 hugetlb_fix_reserve_counts(inode);
466 }
467
468 unlock_page(page);
469 mutex_unlock(&hugetlb_fault_mutex_table[hash]);
470 }
471 huge_pagevec_release(&pvec);
472 cond_resched();
473 }
474
475 if (truncate_op)
476 (void)hugetlb_unreserve_pages(inode, start, LONG_MAX, freed);
477}
478
479static void hugetlbfs_evict_inode(struct inode *inode)
480{
481 struct resv_map *resv_map;
482
483 remove_inode_hugepages(inode, 0, LLONG_MAX);
484 resv_map = (struct resv_map *)inode->i_mapping->private_data;
485
486 if (resv_map)
487 resv_map_release(&resv_map->refs);
488 clear_inode(inode);
489}
490
491static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
492{
493 pgoff_t pgoff;
494 struct address_space *mapping = inode->i_mapping;
495 struct hstate *h = hstate_inode(inode);
496
497 BUG_ON(offset & ~huge_page_mask(h));
498 pgoff = offset >> PAGE_SHIFT;
499
500 i_size_write(inode, offset);
501 i_mmap_lock_write(mapping);
502 if (!RB_EMPTY_ROOT(&mapping->i_mmap.rb_root))
503 hugetlb_vmdelete_list(&mapping->i_mmap, pgoff, 0);
504 i_mmap_unlock_write(mapping);
505 remove_inode_hugepages(inode, offset, LLONG_MAX);
506 return 0;
507}
508
509static long hugetlbfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
510{
511 struct hstate *h = hstate_inode(inode);
512 loff_t hpage_size = huge_page_size(h);
513 loff_t hole_start, hole_end;
514
515
516
517
518
519 hole_start = round_up(offset, hpage_size);
520 hole_end = round_down(offset + len, hpage_size);
521
522 if (hole_end > hole_start) {
523 struct address_space *mapping = inode->i_mapping;
524 struct hugetlbfs_inode_info *info = HUGETLBFS_I(inode);
525
526 inode_lock(inode);
527
528
529 if (info->seals & F_SEAL_WRITE) {
530 inode_unlock(inode);
531 return -EPERM;
532 }
533
534 i_mmap_lock_write(mapping);
535 if (!RB_EMPTY_ROOT(&mapping->i_mmap.rb_root))
536 hugetlb_vmdelete_list(&mapping->i_mmap,
537 hole_start >> PAGE_SHIFT,
538 hole_end >> PAGE_SHIFT);
539 i_mmap_unlock_write(mapping);
540 remove_inode_hugepages(inode, hole_start, hole_end);
541 inode_unlock(inode);
542 }
543
544 return 0;
545}
546
547static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
548 loff_t len)
549{
550 struct inode *inode = file_inode(file);
551 struct hugetlbfs_inode_info *info = HUGETLBFS_I(inode);
552 struct address_space *mapping = inode->i_mapping;
553 struct hstate *h = hstate_inode(inode);
554 struct vm_area_struct pseudo_vma;
555 struct mm_struct *mm = current->mm;
556 loff_t hpage_size = huge_page_size(h);
557 unsigned long hpage_shift = huge_page_shift(h);
558 pgoff_t start, index, end;
559 int error;
560 u32 hash;
561
562 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
563 return -EOPNOTSUPP;
564
565 if (mode & FALLOC_FL_PUNCH_HOLE)
566 return hugetlbfs_punch_hole(inode, offset, len);
567
568
569
570
571
572
573 start = offset >> hpage_shift;
574 end = (offset + len + hpage_size - 1) >> hpage_shift;
575
576 inode_lock(inode);
577
578
579 error = inode_newsize_ok(inode, offset + len);
580 if (error)
581 goto out;
582
583 if ((info->seals & F_SEAL_GROW) && offset + len > inode->i_size) {
584 error = -EPERM;
585 goto out;
586 }
587
588
589
590
591
592
593 memset(&pseudo_vma, 0, sizeof(struct vm_area_struct));
594 pseudo_vma.vm_flags = (VM_HUGETLB | VM_MAYSHARE | VM_SHARED);
595 pseudo_vma.vm_file = file;
596
597 for (index = start; index < end; index++) {
598
599
600
601
602 struct page *page;
603 unsigned long addr;
604 int avoid_reserve = 0;
605
606 cond_resched();
607
608
609
610
611
612 if (signal_pending(current)) {
613 error = -EINTR;
614 break;
615 }
616
617
618 hugetlb_set_vma_policy(&pseudo_vma, inode, index);
619
620
621 addr = index * hpage_size;
622
623
624 hash = hugetlb_fault_mutex_hash(h, mm, &pseudo_vma, mapping,
625 index, addr);
626 mutex_lock(&hugetlb_fault_mutex_table[hash]);
627
628
629 page = find_get_page(mapping, index);
630 if (page) {
631 put_page(page);
632 mutex_unlock(&hugetlb_fault_mutex_table[hash]);
633 hugetlb_drop_vma_policy(&pseudo_vma);
634 continue;
635 }
636
637
638 page = alloc_huge_page(&pseudo_vma, addr, avoid_reserve);
639 hugetlb_drop_vma_policy(&pseudo_vma);
640 if (IS_ERR(page)) {
641 mutex_unlock(&hugetlb_fault_mutex_table[hash]);
642 error = PTR_ERR(page);
643 goto out;
644 }
645 clear_huge_page(page, addr, pages_per_huge_page(h));
646 __SetPageUptodate(page);
647 error = huge_add_to_page_cache(page, mapping, index);
648 if (unlikely(error)) {
649 put_page(page);
650 mutex_unlock(&hugetlb_fault_mutex_table[hash]);
651 goto out;
652 }
653
654 mutex_unlock(&hugetlb_fault_mutex_table[hash]);
655
656
657
658
659
660 unlock_page(page);
661 put_page(page);
662 }
663
664 if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size)
665 i_size_write(inode, offset + len);
666 inode->i_ctime = current_time(inode);
667out:
668 inode_unlock(inode);
669 return error;
670}
671
672static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
673{
674 struct inode *inode = d_inode(dentry);
675 struct hstate *h = hstate_inode(inode);
676 int error;
677 unsigned int ia_valid = attr->ia_valid;
678 struct hugetlbfs_inode_info *info = HUGETLBFS_I(inode);
679
680 BUG_ON(!inode);
681
682 error = setattr_prepare(dentry, attr);
683 if (error)
684 return error;
685
686 if (ia_valid & ATTR_SIZE) {
687 loff_t oldsize = inode->i_size;
688 loff_t newsize = attr->ia_size;
689
690 if (newsize & ~huge_page_mask(h))
691 return -EINVAL;
692
693 if ((newsize < oldsize && (info->seals & F_SEAL_SHRINK)) ||
694 (newsize > oldsize && (info->seals & F_SEAL_GROW)))
695 return -EPERM;
696 error = hugetlb_vmtruncate(inode, newsize);
697 if (error)
698 return error;
699 }
700
701 setattr_copy(inode, attr);
702 mark_inode_dirty(inode);
703 return 0;
704}
705
706static struct inode *hugetlbfs_get_root(struct super_block *sb,
707 struct hugetlbfs_config *config)
708{
709 struct inode *inode;
710
711 inode = new_inode(sb);
712 if (inode) {
713 inode->i_ino = get_next_ino();
714 inode->i_mode = S_IFDIR | config->mode;
715 inode->i_uid = config->uid;
716 inode->i_gid = config->gid;
717 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
718 inode->i_op = &hugetlbfs_dir_inode_operations;
719 inode->i_fop = &simple_dir_operations;
720
721 inc_nlink(inode);
722 lockdep_annotate_inode_mutex_key(inode);
723 }
724 return inode;
725}
726
727
728
729
730
731
732
733static struct lock_class_key hugetlbfs_i_mmap_rwsem_key;
734
735static struct inode *hugetlbfs_get_inode(struct super_block *sb,
736 struct inode *dir,
737 umode_t mode, dev_t dev)
738{
739 struct inode *inode;
740 struct resv_map *resv_map;
741
742 resv_map = resv_map_alloc();
743 if (!resv_map)
744 return NULL;
745
746 inode = new_inode(sb);
747 if (inode) {
748 struct hugetlbfs_inode_info *info = HUGETLBFS_I(inode);
749
750 inode->i_ino = get_next_ino();
751 inode_init_owner(inode, dir, mode);
752 lockdep_set_class(&inode->i_mapping->i_mmap_rwsem,
753 &hugetlbfs_i_mmap_rwsem_key);
754 inode->i_mapping->a_ops = &hugetlbfs_aops;
755 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
756 inode->i_mapping->private_data = resv_map;
757 info->seals = F_SEAL_SEAL;
758 switch (mode & S_IFMT) {
759 default:
760 init_special_inode(inode, mode, dev);
761 break;
762 case S_IFREG:
763 inode->i_op = &hugetlbfs_inode_operations;
764 inode->i_fop = &hugetlbfs_file_operations;
765 break;
766 case S_IFDIR:
767 inode->i_op = &hugetlbfs_dir_inode_operations;
768 inode->i_fop = &simple_dir_operations;
769
770
771 inc_nlink(inode);
772 break;
773 case S_IFLNK:
774 inode->i_op = &page_symlink_inode_operations;
775 inode_nohighmem(inode);
776 break;
777 }
778 lockdep_annotate_inode_mutex_key(inode);
779 } else
780 kref_put(&resv_map->refs, resv_map_release);
781
782 return inode;
783}
784
785
786
787
788static int hugetlbfs_mknod(struct inode *dir,
789 struct dentry *dentry, umode_t mode, dev_t dev)
790{
791 struct inode *inode;
792 int error = -ENOSPC;
793
794 inode = hugetlbfs_get_inode(dir->i_sb, dir, mode, dev);
795 if (inode) {
796 dir->i_ctime = dir->i_mtime = current_time(dir);
797 d_instantiate(dentry, inode);
798 dget(dentry);
799 error = 0;
800 }
801 return error;
802}
803
804static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
805{
806 int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0);
807 if (!retval)
808 inc_nlink(dir);
809 return retval;
810}
811
812static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl)
813{
814 return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0);
815}
816
817static int hugetlbfs_symlink(struct inode *dir,
818 struct dentry *dentry, const char *symname)
819{
820 struct inode *inode;
821 int error = -ENOSPC;
822
823 inode = hugetlbfs_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0);
824 if (inode) {
825 int l = strlen(symname)+1;
826 error = page_symlink(inode, symname, l);
827 if (!error) {
828 d_instantiate(dentry, inode);
829 dget(dentry);
830 } else
831 iput(inode);
832 }
833 dir->i_ctime = dir->i_mtime = current_time(dir);
834
835 return error;
836}
837
838
839
840
841static int hugetlbfs_set_page_dirty(struct page *page)
842{
843 struct page *head = compound_head(page);
844
845 SetPageDirty(head);
846 return 0;
847}
848
849static int hugetlbfs_migrate_page(struct address_space *mapping,
850 struct page *newpage, struct page *page,
851 enum migrate_mode mode)
852{
853 int rc;
854
855 rc = migrate_huge_page_move_mapping(mapping, newpage, page);
856 if (rc != MIGRATEPAGE_SUCCESS)
857 return rc;
858 if (mode != MIGRATE_SYNC_NO_COPY)
859 migrate_page_copy(newpage, page);
860 else
861 migrate_page_states(newpage, page);
862
863 return MIGRATEPAGE_SUCCESS;
864}
865
866static int hugetlbfs_error_remove_page(struct address_space *mapping,
867 struct page *page)
868{
869 struct inode *inode = mapping->host;
870 pgoff_t index = page->index;
871
872 remove_huge_page(page);
873 if (unlikely(hugetlb_unreserve_pages(inode, index, index + 1, 1)))
874 hugetlb_fix_reserve_counts(inode);
875
876 return 0;
877}
878
879
880
881
882static int hugetlbfs_show_options(struct seq_file *m, struct dentry *root)
883{
884 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(root->d_sb);
885 struct hugepage_subpool *spool = sbinfo->spool;
886 unsigned long hpage_size = huge_page_size(sbinfo->hstate);
887 unsigned hpage_shift = huge_page_shift(sbinfo->hstate);
888 char mod;
889
890 if (!uid_eq(sbinfo->uid, GLOBAL_ROOT_UID))
891 seq_printf(m, ",uid=%u",
892 from_kuid_munged(&init_user_ns, sbinfo->uid));
893 if (!gid_eq(sbinfo->gid, GLOBAL_ROOT_GID))
894 seq_printf(m, ",gid=%u",
895 from_kgid_munged(&init_user_ns, sbinfo->gid));
896 if (sbinfo->mode != 0755)
897 seq_printf(m, ",mode=%o", sbinfo->mode);
898 if (sbinfo->max_inodes != -1)
899 seq_printf(m, ",nr_inodes=%lu", sbinfo->max_inodes);
900
901 hpage_size /= 1024;
902 mod = 'K';
903 if (hpage_size >= 1024) {
904 hpage_size /= 1024;
905 mod = 'M';
906 }
907 seq_printf(m, ",pagesize=%lu%c", hpage_size, mod);
908 if (spool) {
909 if (spool->max_hpages != -1)
910 seq_printf(m, ",size=%llu",
911 (unsigned long long)spool->max_hpages << hpage_shift);
912 if (spool->min_hpages != -1)
913 seq_printf(m, ",min_size=%llu",
914 (unsigned long long)spool->min_hpages << hpage_shift);
915 }
916 return 0;
917}
918
919static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
920{
921 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
922 struct hstate *h = hstate_inode(d_inode(dentry));
923
924 buf->f_type = HUGETLBFS_MAGIC;
925 buf->f_bsize = huge_page_size(h);
926 if (sbinfo) {
927 spin_lock(&sbinfo->stat_lock);
928
929
930 if (sbinfo->spool) {
931 long free_pages;
932
933 spin_lock(&sbinfo->spool->lock);
934 buf->f_blocks = sbinfo->spool->max_hpages;
935 free_pages = sbinfo->spool->max_hpages
936 - sbinfo->spool->used_hpages;
937 buf->f_bavail = buf->f_bfree = free_pages;
938 spin_unlock(&sbinfo->spool->lock);
939 buf->f_files = sbinfo->max_inodes;
940 buf->f_ffree = sbinfo->free_inodes;
941 }
942 spin_unlock(&sbinfo->stat_lock);
943 }
944 buf->f_namelen = NAME_MAX;
945 return 0;
946}
947
948static void hugetlbfs_put_super(struct super_block *sb)
949{
950 struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb);
951
952 if (sbi) {
953 sb->s_fs_info = NULL;
954
955 if (sbi->spool)
956 hugepage_put_subpool(sbi->spool);
957
958 kfree(sbi);
959 }
960}
961
962static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo)
963{
964 if (sbinfo->free_inodes >= 0) {
965 spin_lock(&sbinfo->stat_lock);
966 if (unlikely(!sbinfo->free_inodes)) {
967 spin_unlock(&sbinfo->stat_lock);
968 return 0;
969 }
970 sbinfo->free_inodes--;
971 spin_unlock(&sbinfo->stat_lock);
972 }
973
974 return 1;
975}
976
977static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
978{
979 if (sbinfo->free_inodes >= 0) {
980 spin_lock(&sbinfo->stat_lock);
981 sbinfo->free_inodes++;
982 spin_unlock(&sbinfo->stat_lock);
983 }
984}
985
986
987static struct kmem_cache *hugetlbfs_inode_cachep;
988
989static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
990{
991 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
992 struct hugetlbfs_inode_info *p;
993
994 if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
995 return NULL;
996 p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL);
997 if (unlikely(!p)) {
998 hugetlbfs_inc_free_inodes(sbinfo);
999 return NULL;
1000 }
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011 mpol_shared_policy_init(&p->policy, NULL);
1012
1013 return &p->vfs_inode;
1014}
1015
1016static void hugetlbfs_i_callback(struct rcu_head *head)
1017{
1018 struct inode *inode = container_of(head, struct inode, i_rcu);
1019 kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
1020}
1021
1022static void hugetlbfs_destroy_inode(struct inode *inode)
1023{
1024 hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
1025 mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
1026 call_rcu(&inode->i_rcu, hugetlbfs_i_callback);
1027}
1028
1029static const struct address_space_operations hugetlbfs_aops = {
1030 .write_begin = hugetlbfs_write_begin,
1031 .write_end = hugetlbfs_write_end,
1032 .set_page_dirty = hugetlbfs_set_page_dirty,
1033 .migratepage = hugetlbfs_migrate_page,
1034 .error_remove_page = hugetlbfs_error_remove_page,
1035};
1036
1037
1038static void init_once(void *foo)
1039{
1040 struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
1041
1042 inode_init_once(&ei->vfs_inode);
1043}
1044
1045const struct file_operations hugetlbfs_file_operations = {
1046 .read_iter = hugetlbfs_read_iter,
1047 .mmap = hugetlbfs_file_mmap,
1048 .fsync = noop_fsync,
1049 .get_unmapped_area = hugetlb_get_unmapped_area,
1050 .llseek = default_llseek,
1051 .fallocate = hugetlbfs_fallocate,
1052};
1053
1054static const struct inode_operations hugetlbfs_dir_inode_operations = {
1055 .create = hugetlbfs_create,
1056 .lookup = simple_lookup,
1057 .link = simple_link,
1058 .unlink = simple_unlink,
1059 .symlink = hugetlbfs_symlink,
1060 .mkdir = hugetlbfs_mkdir,
1061 .rmdir = simple_rmdir,
1062 .mknod = hugetlbfs_mknod,
1063 .rename = simple_rename,
1064 .setattr = hugetlbfs_setattr,
1065};
1066
1067static const struct inode_operations hugetlbfs_inode_operations = {
1068 .setattr = hugetlbfs_setattr,
1069};
1070
1071static const struct super_operations hugetlbfs_ops = {
1072 .alloc_inode = hugetlbfs_alloc_inode,
1073 .destroy_inode = hugetlbfs_destroy_inode,
1074 .evict_inode = hugetlbfs_evict_inode,
1075 .statfs = hugetlbfs_statfs,
1076 .put_super = hugetlbfs_put_super,
1077 .show_options = hugetlbfs_show_options,
1078};
1079
1080enum hugetlbfs_size_type { NO_SIZE, SIZE_STD, SIZE_PERCENT };
1081
1082
1083
1084
1085
1086
1087static long
1088hugetlbfs_size_to_hpages(struct hstate *h, unsigned long long size_opt,
1089 enum hugetlbfs_size_type val_type)
1090{
1091 if (val_type == NO_SIZE)
1092 return -1;
1093
1094 if (val_type == SIZE_PERCENT) {
1095 size_opt <<= huge_page_shift(h);
1096 size_opt *= h->max_huge_pages;
1097 do_div(size_opt, 100);
1098 }
1099
1100 size_opt >>= huge_page_shift(h);
1101 return size_opt;
1102}
1103
1104static int
1105hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
1106{
1107 char *p, *rest;
1108 substring_t args[MAX_OPT_ARGS];
1109 int option;
1110 unsigned long long max_size_opt = 0, min_size_opt = 0;
1111 enum hugetlbfs_size_type max_val_type = NO_SIZE, min_val_type = NO_SIZE;
1112
1113 if (!options)
1114 return 0;
1115
1116 while ((p = strsep(&options, ",")) != NULL) {
1117 int token;
1118 if (!*p)
1119 continue;
1120
1121 token = match_token(p, tokens, args);
1122 switch (token) {
1123 case Opt_uid:
1124 if (match_int(&args[0], &option))
1125 goto bad_val;
1126 pconfig->uid = make_kuid(current_user_ns(), option);
1127 if (!uid_valid(pconfig->uid))
1128 goto bad_val;
1129 break;
1130
1131 case Opt_gid:
1132 if (match_int(&args[0], &option))
1133 goto bad_val;
1134 pconfig->gid = make_kgid(current_user_ns(), option);
1135 if (!gid_valid(pconfig->gid))
1136 goto bad_val;
1137 break;
1138
1139 case Opt_mode:
1140 if (match_octal(&args[0], &option))
1141 goto bad_val;
1142 pconfig->mode = option & 01777U;
1143 break;
1144
1145 case Opt_size: {
1146
1147 if (!isdigit(*args[0].from))
1148 goto bad_val;
1149 max_size_opt = memparse(args[0].from, &rest);
1150 max_val_type = SIZE_STD;
1151 if (*rest == '%')
1152 max_val_type = SIZE_PERCENT;
1153 break;
1154 }
1155
1156 case Opt_nr_inodes:
1157
1158 if (!isdigit(*args[0].from))
1159 goto bad_val;
1160 pconfig->nr_inodes = memparse(args[0].from, &rest);
1161 break;
1162
1163 case Opt_pagesize: {
1164 unsigned long ps;
1165 ps = memparse(args[0].from, &rest);
1166 pconfig->hstate = size_to_hstate(ps);
1167 if (!pconfig->hstate) {
1168 pr_err("Unsupported page size %lu MB\n",
1169 ps >> 20);
1170 return -EINVAL;
1171 }
1172 break;
1173 }
1174
1175 case Opt_min_size: {
1176
1177 if (!isdigit(*args[0].from))
1178 goto bad_val;
1179 min_size_opt = memparse(args[0].from, &rest);
1180 min_val_type = SIZE_STD;
1181 if (*rest == '%')
1182 min_val_type = SIZE_PERCENT;
1183 break;
1184 }
1185
1186 default:
1187 pr_err("Bad mount option: \"%s\"\n", p);
1188 return -EINVAL;
1189 break;
1190 }
1191 }
1192
1193
1194
1195
1196
1197 pconfig->max_hpages = hugetlbfs_size_to_hpages(pconfig->hstate,
1198 max_size_opt, max_val_type);
1199 pconfig->min_hpages = hugetlbfs_size_to_hpages(pconfig->hstate,
1200 min_size_opt, min_val_type);
1201
1202
1203
1204
1205 if (max_val_type > NO_SIZE &&
1206 pconfig->min_hpages > pconfig->max_hpages) {
1207 pr_err("minimum size can not be greater than maximum size\n");
1208 return -EINVAL;
1209 }
1210
1211 return 0;
1212
1213bad_val:
1214 pr_err("Bad value '%s' for mount option '%s'\n", args[0].from, p);
1215 return -EINVAL;
1216}
1217
1218static int
1219hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
1220{
1221 int ret;
1222 struct hugetlbfs_config config;
1223 struct hugetlbfs_sb_info *sbinfo;
1224
1225 config.max_hpages = -1;
1226 config.nr_inodes = -1;
1227 config.uid = current_fsuid();
1228 config.gid = current_fsgid();
1229 config.mode = 0755;
1230 config.hstate = &default_hstate;
1231 config.min_hpages = -1;
1232 ret = hugetlbfs_parse_options(data, &config);
1233 if (ret)
1234 return ret;
1235
1236 sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL);
1237 if (!sbinfo)
1238 return -ENOMEM;
1239 sb->s_fs_info = sbinfo;
1240 sbinfo->hstate = config.hstate;
1241 spin_lock_init(&sbinfo->stat_lock);
1242 sbinfo->max_inodes = config.nr_inodes;
1243 sbinfo->free_inodes = config.nr_inodes;
1244 sbinfo->spool = NULL;
1245 sbinfo->uid = config.uid;
1246 sbinfo->gid = config.gid;
1247 sbinfo->mode = config.mode;
1248
1249
1250
1251
1252
1253
1254 if (config.max_hpages != -1 || config.min_hpages != -1) {
1255 sbinfo->spool = hugepage_new_subpool(config.hstate,
1256 config.max_hpages,
1257 config.min_hpages);
1258 if (!sbinfo->spool)
1259 goto out_free;
1260 }
1261 sb->s_maxbytes = MAX_LFS_FILESIZE;
1262 sb->s_blocksize = huge_page_size(config.hstate);
1263 sb->s_blocksize_bits = huge_page_shift(config.hstate);
1264 sb->s_magic = HUGETLBFS_MAGIC;
1265 sb->s_op = &hugetlbfs_ops;
1266 sb->s_time_gran = 1;
1267 sb->s_root = d_make_root(hugetlbfs_get_root(sb, &config));
1268 if (!sb->s_root)
1269 goto out_free;
1270 return 0;
1271out_free:
1272 kfree(sbinfo->spool);
1273 kfree(sbinfo);
1274 return -ENOMEM;
1275}
1276
1277static struct dentry *hugetlbfs_mount(struct file_system_type *fs_type,
1278 int flags, const char *dev_name, void *data)
1279{
1280 return mount_nodev(fs_type, flags, data, hugetlbfs_fill_super);
1281}
1282
1283static struct file_system_type hugetlbfs_fs_type = {
1284 .name = "hugetlbfs",
1285 .mount = hugetlbfs_mount,
1286 .kill_sb = kill_litter_super,
1287};
1288
1289static struct vfsmount *hugetlbfs_vfsmount[HUGE_MAX_HSTATE];
1290
1291static int can_do_hugetlb_shm(void)
1292{
1293 kgid_t shm_group;
1294 shm_group = make_kgid(&init_user_ns, sysctl_hugetlb_shm_group);
1295 return capable(CAP_IPC_LOCK) || in_group_p(shm_group);
1296}
1297
1298static int get_hstate_idx(int page_size_log)
1299{
1300 struct hstate *h = hstate_sizelog(page_size_log);
1301
1302 if (!h)
1303 return -1;
1304 return h - hstates;
1305}
1306
1307static const struct dentry_operations anon_ops = {
1308 .d_dname = simple_dname
1309};
1310
1311
1312
1313
1314
1315struct file *hugetlb_file_setup(const char *name, size_t size,
1316 vm_flags_t acctflag, struct user_struct **user,
1317 int creat_flags, int page_size_log)
1318{
1319 struct file *file = ERR_PTR(-ENOMEM);
1320 struct inode *inode;
1321 struct path path;
1322 struct super_block *sb;
1323 struct qstr quick_string;
1324 int hstate_idx;
1325
1326 hstate_idx = get_hstate_idx(page_size_log);
1327 if (hstate_idx < 0)
1328 return ERR_PTR(-ENODEV);
1329
1330 *user = NULL;
1331 if (!hugetlbfs_vfsmount[hstate_idx])
1332 return ERR_PTR(-ENOENT);
1333
1334 if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) {
1335 *user = current_user();
1336 if (user_shm_lock(size, *user)) {
1337 task_lock(current);
1338 pr_warn_once("%s (%d): Using mlock ulimits for SHM_HUGETLB is deprecated\n",
1339 current->comm, current->pid);
1340 task_unlock(current);
1341 } else {
1342 *user = NULL;
1343 return ERR_PTR(-EPERM);
1344 }
1345 }
1346
1347 sb = hugetlbfs_vfsmount[hstate_idx]->mnt_sb;
1348 quick_string.name = name;
1349 quick_string.len = strlen(quick_string.name);
1350 quick_string.hash = 0;
1351 path.dentry = d_alloc_pseudo(sb, &quick_string);
1352 if (!path.dentry)
1353 goto out_shm_unlock;
1354
1355 d_set_d_op(path.dentry, &anon_ops);
1356 path.mnt = mntget(hugetlbfs_vfsmount[hstate_idx]);
1357 file = ERR_PTR(-ENOSPC);
1358 inode = hugetlbfs_get_inode(sb, NULL, S_IFREG | S_IRWXUGO, 0);
1359 if (!inode)
1360 goto out_dentry;
1361 if (creat_flags == HUGETLB_SHMFS_INODE)
1362 inode->i_flags |= S_PRIVATE;
1363
1364 file = ERR_PTR(-ENOMEM);
1365 if (hugetlb_reserve_pages(inode, 0,
1366 size >> huge_page_shift(hstate_inode(inode)), NULL,
1367 acctflag))
1368 goto out_inode;
1369
1370 d_instantiate(path.dentry, inode);
1371 inode->i_size = size;
1372 clear_nlink(inode);
1373
1374 file = alloc_file(&path, FMODE_WRITE | FMODE_READ,
1375 &hugetlbfs_file_operations);
1376 if (IS_ERR(file))
1377 goto out_dentry;
1378
1379 return file;
1380
1381out_inode:
1382 iput(inode);
1383out_dentry:
1384 path_put(&path);
1385out_shm_unlock:
1386 if (*user) {
1387 user_shm_unlock(size, *user);
1388 *user = NULL;
1389 }
1390 return file;
1391}
1392
1393static int __init init_hugetlbfs_fs(void)
1394{
1395 struct hstate *h;
1396 int error;
1397 int i;
1398
1399 if (!hugepages_supported()) {
1400 pr_info("disabling because there are no supported hugepage sizes\n");
1401 return -ENOTSUPP;
1402 }
1403
1404 error = -ENOMEM;
1405 hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
1406 sizeof(struct hugetlbfs_inode_info),
1407 0, SLAB_ACCOUNT, init_once);
1408 if (hugetlbfs_inode_cachep == NULL)
1409 goto out2;
1410
1411 error = register_filesystem(&hugetlbfs_fs_type);
1412 if (error)
1413 goto out;
1414
1415 i = 0;
1416 for_each_hstate(h) {
1417 char buf[50];
1418 unsigned ps_kb = 1U << (h->order + PAGE_SHIFT - 10);
1419
1420 snprintf(buf, sizeof(buf), "pagesize=%uK", ps_kb);
1421 hugetlbfs_vfsmount[i] = kern_mount_data(&hugetlbfs_fs_type,
1422 buf);
1423
1424 if (IS_ERR(hugetlbfs_vfsmount[i])) {
1425 pr_err("Cannot mount internal hugetlbfs for "
1426 "page size %uK", ps_kb);
1427 error = PTR_ERR(hugetlbfs_vfsmount[i]);
1428 hugetlbfs_vfsmount[i] = NULL;
1429 }
1430 i++;
1431 }
1432
1433 if (!IS_ERR_OR_NULL(hugetlbfs_vfsmount[default_hstate_idx]))
1434 return 0;
1435
1436 out:
1437 kmem_cache_destroy(hugetlbfs_inode_cachep);
1438 out2:
1439 return error;
1440}
1441fs_initcall(init_hugetlbfs_fs)
1442