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1/*
2 * hugetlbpage-backed filesystem. Based on ramfs.
3 *
4 * William Irwin, 2002
5 *
6 * Copyright (C) 2002 Linus Torvalds.
7 */
8
9#include <linux/module.h>
10#include <linux/thread_info.h>
11#include <asm/current.h>
12#include <linux/sched.h> /* remove ASAP */
13#include <linux/fs.h>
14#include <linux/mount.h>
15#include <linux/file.h>
16#include <linux/kernel.h>
17#include <linux/writeback.h>
18#include <linux/pagemap.h>
19#include <linux/highmem.h>
20#include <linux/init.h>
21#include <linux/string.h>
22#include <linux/capability.h>
23#include <linux/ctype.h>
24#include <linux/backing-dev.h>
25#include <linux/hugetlb.h>
26#include <linux/pagevec.h>
27#include <linux/parser.h>
28#include <linux/mman.h>
29#include <linux/slab.h>
30#include <linux/dnotify.h>
31#include <linux/statfs.h>
32#include <linux/security.h>
33#include <linux/magic.h>
34#include <linux/migrate.h>
35
36#include <asm/uaccess.h>
37
38static const struct super_operations hugetlbfs_ops;
39static const struct address_space_operations hugetlbfs_aops;
40const struct file_operations hugetlbfs_file_operations;
41static const struct inode_operations hugetlbfs_dir_inode_operations;
42static const struct inode_operations hugetlbfs_inode_operations;
43
44struct hugetlbfs_config {
45 uid_t uid;
46 gid_t gid;
47 umode_t mode;
48 long nr_blocks;
49 long nr_inodes;
50 struct hstate *hstate;
51};
52
53struct hugetlbfs_inode_info {
54 struct shared_policy policy;
55 struct inode vfs_inode;
56};
57
58static inline struct hugetlbfs_inode_info *HUGETLBFS_I(struct inode *inode)
59{
60 return container_of(inode, struct hugetlbfs_inode_info, vfs_inode);
61}
62
63static struct backing_dev_info hugetlbfs_backing_dev_info = {
64 .name = "hugetlbfs",
65 .ra_pages = 0, /* No readahead */
66 .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
67};
68
69int sysctl_hugetlb_shm_group;
70
71enum {
72 Opt_size, Opt_nr_inodes,
73 Opt_mode, Opt_uid, Opt_gid,
74 Opt_pagesize,
75 Opt_err,
76};
77
78static const match_table_t tokens = {
79 {Opt_size, "size=%s"},
80 {Opt_nr_inodes, "nr_inodes=%s"},
81 {Opt_mode, "mode=%o"},
82 {Opt_uid, "uid=%u"},
83 {Opt_gid, "gid=%u"},
84 {Opt_pagesize, "pagesize=%s"},
85 {Opt_err, NULL},
86};
87
88static void huge_pagevec_release(struct pagevec *pvec)
89{
90 int i;
91
92 for (i = 0; i < pagevec_count(pvec); ++i)
93 put_page(pvec->pages[i]);
94
95 pagevec_reinit(pvec);
96}
97
98static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
99{
100 struct inode *inode = file->f_path.dentry->d_inode;
101 loff_t len, vma_len;
102 int ret;
103 struct hstate *h = hstate_file(file);
104
105 /*
106 * vma address alignment (but not the pgoff alignment) has
107 * already been checked by prepare_hugepage_range. If you add
108 * any error returns here, do so after setting VM_HUGETLB, so
109 * is_vm_hugetlb_page tests below unmap_region go the right
110 * way when do_mmap_pgoff unwinds (may be important on powerpc
111 * and ia64).
112 */
113 vma->vm_flags |= VM_HUGETLB | VM_RESERVED;
114 vma->vm_ops = &hugetlb_vm_ops;
115
116 if (vma->vm_pgoff & (~huge_page_mask(h) >> PAGE_SHIFT))
117 return -EINVAL;
118
119 vma_len = (loff_t)(vma->vm_end - vma->vm_start);
120
121 mutex_lock(&inode->i_mutex);
122 file_accessed(file);
123
124 ret = -ENOMEM;
125 len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
126
127 if (hugetlb_reserve_pages(inode,
128 vma->vm_pgoff >> huge_page_order(h),
129 len >> huge_page_shift(h), vma,
130 vma->vm_flags))
131 goto out;
132
133 ret = 0;
134 hugetlb_prefault_arch_hook(vma->vm_mm);
135 if (vma->vm_flags & VM_WRITE && inode->i_size < len)
136 inode->i_size = len;
137out:
138 mutex_unlock(&inode->i_mutex);
139
140 return ret;
141}
142
143/*
144 * Called under down_write(mmap_sem).
145 */
146
147#ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
148static unsigned long
149hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
150 unsigned long len, unsigned long pgoff, unsigned long flags)
151{
152 struct mm_struct *mm = current->mm;
153 struct vm_area_struct *vma;
154 unsigned long start_addr;
155 struct hstate *h = hstate_file(file);
156
157 if (len & ~huge_page_mask(h))
158 return -EINVAL;
159 if (len > TASK_SIZE)
160 return -ENOMEM;
161
162 if (flags & MAP_FIXED) {
163 if (prepare_hugepage_range(file, addr, len))
164 return -EINVAL;
165 return addr;
166 }
167
168 if (addr) {
169 addr = ALIGN(addr, huge_page_size(h));
170 vma = find_vma(mm, addr);
171 if (TASK_SIZE - len >= addr &&
172 (!vma || addr + len <= vma->vm_start))
173 return addr;
174 }
175
176 if (len > mm->cached_hole_size)
177 start_addr = mm->free_area_cache;
178 else {
179 start_addr = TASK_UNMAPPED_BASE;
180 mm->cached_hole_size = 0;
181 }
182
183full_search:
184 addr = ALIGN(start_addr, huge_page_size(h));
185
186 for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
187 /* At this point: (!vma || addr < vma->vm_end). */
188 if (TASK_SIZE - len < addr) {
189 /*
190 * Start a new search - just in case we missed
191 * some holes.
192 */
193 if (start_addr != TASK_UNMAPPED_BASE) {
194 start_addr = TASK_UNMAPPED_BASE;
195 mm->cached_hole_size = 0;
196 goto full_search;
197 }
198 return -ENOMEM;
199 }
200
201 if (!vma || addr + len <= vma->vm_start) {
202 mm->free_area_cache = addr + len;
203 return addr;
204 }
205 if (addr + mm->cached_hole_size < vma->vm_start)
206 mm->cached_hole_size = vma->vm_start - addr;
207 addr = ALIGN(vma->vm_end, huge_page_size(h));
208 }
209}
210#endif
211
212static int
213hugetlbfs_read_actor(struct page *page, unsigned long offset,
214 char __user *buf, unsigned long count,
215 unsigned long size)
216{
217 char *kaddr;
218 unsigned long left, copied = 0;
219 int i, chunksize;
220
221 if (size > count)
222 size = count;
223
224 /* Find which 4k chunk and offset with in that chunk */
225 i = offset >> PAGE_CACHE_SHIFT;
226 offset = offset & ~PAGE_CACHE_MASK;
227
228 while (size) {
229 chunksize = PAGE_CACHE_SIZE;
230 if (offset)
231 chunksize -= offset;
232 if (chunksize > size)
233 chunksize = size;
234 kaddr = kmap(&page[i]);
235 left = __copy_to_user(buf, kaddr + offset, chunksize);
236 kunmap(&page[i]);
237 if (left) {
238 copied += (chunksize - left);
239 break;
240 }
241 offset = 0;
242 size -= chunksize;
243 buf += chunksize;
244 copied += chunksize;
245 i++;
246 }
247 return copied ? copied : -EFAULT;
248}
249
250/*
251 * Support for read() - Find the page attached to f_mapping and copy out the
252 * data. Its *very* similar to do_generic_mapping_read(), we can't use that
253 * since it has PAGE_CACHE_SIZE assumptions.
254 */
255static ssize_t hugetlbfs_read(struct file *filp, char __user *buf,
256 size_t len, loff_t *ppos)
257{
258 struct hstate *h = hstate_file(filp);
259 struct address_space *mapping = filp->f_mapping;
260 struct inode *inode = mapping->host;
261 unsigned long index = *ppos >> huge_page_shift(h);
262 unsigned long offset = *ppos & ~huge_page_mask(h);
263 unsigned long end_index;
264 loff_t isize;
265 ssize_t retval = 0;
266
267 /* validate length */
268 if (len == 0)
269 goto out;
270
271 for (;;) {
272 struct page *page;
273 unsigned long nr, ret;
274 int ra;
275
276 /* nr is the maximum number of bytes to copy from this page */
277 nr = huge_page_size(h);
278 isize = i_size_read(inode);
279 if (!isize)
280 goto out;
281 end_index = (isize - 1) >> huge_page_shift(h);
282 if (index >= end_index) {
283 if (index > end_index)
284 goto out;
285 nr = ((isize - 1) & ~huge_page_mask(h)) + 1;
286 if (nr <= offset)
287 goto out;
288 }
289 nr = nr - offset;
290
291 /* Find the page */
292 page = find_lock_page(mapping, index);
293 if (unlikely(page == NULL)) {
294 /*
295 * We have a HOLE, zero out the user-buffer for the
296 * length of the hole or request.
297 */
298 ret = len < nr ? len : nr;
299 if (clear_user(buf, ret))
300 ra = -EFAULT;
301 else
302 ra = 0;
303 } else {
304 unlock_page(page);
305
306 /*
307 * We have the page, copy it to user space buffer.
308 */
309 ra = hugetlbfs_read_actor(page, offset, buf, len, nr);
310 ret = ra;
311 page_cache_release(page);
312 }
313 if (ra < 0) {
314 if (retval == 0)
315 retval = ra;
316 goto out;
317 }
318
319 offset += ret;
320 retval += ret;
321 len -= ret;
322 index += offset >> huge_page_shift(h);
323 offset &= ~huge_page_mask(h);
324
325 /* short read or no more work */
326 if ((ret != nr) || (len == 0))
327 break;
328 }
329out:
330 *ppos = ((loff_t)index << huge_page_shift(h)) + offset;
331 return retval;
332}
333
334static int hugetlbfs_write_begin(struct file *file,
335 struct address_space *mapping,
336 loff_t pos, unsigned len, unsigned flags,
337 struct page **pagep, void **fsdata)
338{
339 return -EINVAL;
340}
341
342static int hugetlbfs_write_end(struct file *file, struct address_space *mapping,
343 loff_t pos, unsigned len, unsigned copied,
344 struct page *page, void *fsdata)
345{
346 BUG();
347 return -EINVAL;
348}
349
350static void truncate_huge_page(struct page *page)
351{
352 cancel_dirty_page(page, /* No IO accounting for huge pages? */0);
353 ClearPageUptodate(page);
354 delete_from_page_cache(page);
355}
356
357static void truncate_hugepages(struct inode *inode, loff_t lstart)
358{
359 struct hstate *h = hstate_inode(inode);
360 struct address_space *mapping = &inode->i_data;
361 const pgoff_t start = lstart >> huge_page_shift(h);
362 struct pagevec pvec;
363 pgoff_t next;
364 int i, freed = 0;
365
366 pagevec_init(&pvec, 0);
367 next = start;
368 while (1) {
369 if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
370 if (next == start)
371 break;
372 next = start;
373 continue;
374 }
375
376 for (i = 0; i < pagevec_count(&pvec); ++i) {
377 struct page *page = pvec.pages[i];
378
379 lock_page(page);
380 if (page->index > next)
381 next = page->index;
382 ++next;
383 truncate_huge_page(page);
384 unlock_page(page);
385 freed++;
386 }
387 huge_pagevec_release(&pvec);
388 }
389 BUG_ON(!lstart && mapping->nrpages);
390 hugetlb_unreserve_pages(inode, start, freed);
391}
392
393static void hugetlbfs_evict_inode(struct inode *inode)
394{
395 truncate_hugepages(inode, 0);
396 clear_inode(inode);
397}
398
399static inline void
400hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff)
401{
402 struct vm_area_struct *vma;
403 struct prio_tree_iter iter;
404
405 vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) {
406 unsigned long v_offset;
407
408 /*
409 * Can the expression below overflow on 32-bit arches?
410 * No, because the prio_tree returns us only those vmas
411 * which overlap the truncated area starting at pgoff,
412 * and no vma on a 32-bit arch can span beyond the 4GB.
413 */
414 if (vma->vm_pgoff < pgoff)
415 v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT;
416 else
417 v_offset = 0;
418
419 __unmap_hugepage_range(vma,
420 vma->vm_start + v_offset, vma->vm_end, NULL);
421 }
422}
423
424static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
425{
426 pgoff_t pgoff;
427 struct address_space *mapping = inode->i_mapping;
428 struct hstate *h = hstate_inode(inode);
429
430 BUG_ON(offset & ~huge_page_mask(h));
431 pgoff = offset >> PAGE_SHIFT;
432
433 i_size_write(inode, offset);
434 mutex_lock(&mapping->i_mmap_mutex);
435 if (!prio_tree_empty(&mapping->i_mmap))
436 hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
437 mutex_unlock(&mapping->i_mmap_mutex);
438 truncate_hugepages(inode, offset);
439 return 0;
440}
441
442static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
443{
444 struct inode *inode = dentry->d_inode;
445 struct hstate *h = hstate_inode(inode);
446 int error;
447 unsigned int ia_valid = attr->ia_valid;
448
449 BUG_ON(!inode);
450
451 error = inode_change_ok(inode, attr);
452 if (error)
453 return error;
454
455 if (ia_valid & ATTR_SIZE) {
456 error = -EINVAL;
457 if (attr->ia_size & ~huge_page_mask(h))
458 return -EINVAL;
459 error = hugetlb_vmtruncate(inode, attr->ia_size);
460 if (error)
461 return error;
462 }
463
464 setattr_copy(inode, attr);
465 mark_inode_dirty(inode);
466 return 0;
467}
468
469static struct inode *hugetlbfs_get_root(struct super_block *sb,
470 struct hugetlbfs_config *config)
471{
472 struct inode *inode;
473
474 inode = new_inode(sb);
475 if (inode) {
476 struct hugetlbfs_inode_info *info;
477 inode->i_ino = get_next_ino();
478 inode->i_mode = S_IFDIR | config->mode;
479 inode->i_uid = config->uid;
480 inode->i_gid = config->gid;
481 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
482 info = HUGETLBFS_I(inode);
483 mpol_shared_policy_init(&info->policy, NULL);
484 inode->i_op = &hugetlbfs_dir_inode_operations;
485 inode->i_fop = &simple_dir_operations;
486 /* directory inodes start off with i_nlink == 2 (for "." entry) */
487 inc_nlink(inode);
488 lockdep_annotate_inode_mutex_key(inode);
489 }
490 return inode;
491}
492
493static struct inode *hugetlbfs_get_inode(struct super_block *sb,
494 struct inode *dir,
495 umode_t mode, dev_t dev)
496{
497 struct inode *inode;
498
499 inode = new_inode(sb);
500 if (inode) {
501 struct hugetlbfs_inode_info *info;
502 inode->i_ino = get_next_ino();
503 inode_init_owner(inode, dir, mode);
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 /*
510 * The policy is initialized here even if we are creating a
511 * private inode because initialization simply creates an
512 * an empty rb tree and calls spin_lock_init(), later when we
513 * call mpol_free_shared_policy() it will just return because
514 * the rb tree will still be empty.
515 */
516 mpol_shared_policy_init(&info->policy, NULL);
517 switch (mode & S_IFMT) {
518 default:
519 init_special_inode(inode, mode, dev);
520 break;
521 case S_IFREG:
522 inode->i_op = &hugetlbfs_inode_operations;
523 inode->i_fop = &hugetlbfs_file_operations;
524 break;
525 case S_IFDIR:
526 inode->i_op = &hugetlbfs_dir_inode_operations;
527 inode->i_fop = &simple_dir_operations;
528
529 /* directory inodes start off with i_nlink == 2 (for "." entry) */
530 inc_nlink(inode);
531 break;
532 case S_IFLNK:
533 inode->i_op = &page_symlink_inode_operations;
534 break;
535 }
536 lockdep_annotate_inode_mutex_key(inode);
537 }
538 return inode;
539}
540
541/*
542 * File creation. Allocate an inode, and we're done..
543 */
544static int hugetlbfs_mknod(struct inode *dir,
545 struct dentry *dentry, umode_t mode, dev_t dev)
546{
547 struct inode *inode;
548 int error = -ENOSPC;
549
550 inode = hugetlbfs_get_inode(dir->i_sb, dir, 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
560static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t 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
568static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, struct nameidata *nd)
569{
570 return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0);
571}
572
573static int hugetlbfs_symlink(struct inode *dir,
574 struct dentry *dentry, const char *symname)
575{
576 struct inode *inode;
577 int error = -ENOSPC;
578
579 inode = hugetlbfs_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0);
580 if (inode) {
581 int l = strlen(symname)+1;
582 error = page_symlink(inode, symname, l);
583 if (!error) {
584 d_instantiate(dentry, inode);
585 dget(dentry);
586 } else
587 iput(inode);
588 }
589 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
590
591 return error;
592}
593
594/*
595 * mark the head page dirty
596 */
597static int hugetlbfs_set_page_dirty(struct page *page)
598{
599 struct page *head = compound_head(page);
600
601 SetPageDirty(head);
602 return 0;
603}
604
605static int hugetlbfs_migrate_page(struct address_space *mapping,
606 struct page *newpage, struct page *page,
607 enum migrate_mode mode)
608{
609 int rc;
610
611 rc = migrate_huge_page_move_mapping(mapping, newpage, page);
612 if (rc)
613 return rc;
614 migrate_page_copy(newpage, page);
615
616 return 0;
617}
618
619static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
620{
621 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
622 struct hstate *h = hstate_inode(dentry->d_inode);
623
624 buf->f_type = HUGETLBFS_MAGIC;
625 buf->f_bsize = huge_page_size(h);
626 if (sbinfo) {
627 spin_lock(&sbinfo->stat_lock);
628 /* If no limits set, just report 0 for max/free/used
629 * blocks, like simple_statfs() */
630 if (sbinfo->spool) {
631 long free_pages;
632
633 spin_lock(&sbinfo->spool->lock);
634 buf->f_blocks = sbinfo->spool->max_hpages;
635 free_pages = sbinfo->spool->max_hpages
636 - sbinfo->spool->used_hpages;
637 buf->f_bavail = buf->f_bfree = free_pages;
638 spin_unlock(&sbinfo->spool->lock);
639 buf->f_files = sbinfo->max_inodes;
640 buf->f_ffree = sbinfo->free_inodes;
641 }
642 spin_unlock(&sbinfo->stat_lock);
643 }
644 buf->f_namelen = NAME_MAX;
645 return 0;
646}
647
648static void hugetlbfs_put_super(struct super_block *sb)
649{
650 struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb);
651
652 if (sbi) {
653 sb->s_fs_info = NULL;
654
655 if (sbi->spool)
656 hugepage_put_subpool(sbi->spool);
657
658 kfree(sbi);
659 }
660}
661
662static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo)
663{
664 if (sbinfo->free_inodes >= 0) {
665 spin_lock(&sbinfo->stat_lock);
666 if (unlikely(!sbinfo->free_inodes)) {
667 spin_unlock(&sbinfo->stat_lock);
668 return 0;
669 }
670 sbinfo->free_inodes--;
671 spin_unlock(&sbinfo->stat_lock);
672 }
673
674 return 1;
675}
676
677static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
678{
679 if (sbinfo->free_inodes >= 0) {
680 spin_lock(&sbinfo->stat_lock);
681 sbinfo->free_inodes++;
682 spin_unlock(&sbinfo->stat_lock);
683 }
684}
685
686
687static struct kmem_cache *hugetlbfs_inode_cachep;
688
689static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
690{
691 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
692 struct hugetlbfs_inode_info *p;
693
694 if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
695 return NULL;
696 p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL);
697 if (unlikely(!p)) {
698 hugetlbfs_inc_free_inodes(sbinfo);
699 return NULL;
700 }
701 return &p->vfs_inode;
702}
703
704static void hugetlbfs_i_callback(struct rcu_head *head)
705{
706 struct inode *inode = container_of(head, struct inode, i_rcu);
707 kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
708}
709
710static void hugetlbfs_destroy_inode(struct inode *inode)
711{
712 hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
713 mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
714 call_rcu(&inode->i_rcu, hugetlbfs_i_callback);
715}
716
717static const struct address_space_operations hugetlbfs_aops = {
718 .write_begin = hugetlbfs_write_begin,
719 .write_end = hugetlbfs_write_end,
720 .set_page_dirty = hugetlbfs_set_page_dirty,
721 .migratepage = hugetlbfs_migrate_page,
722};
723
724
725static void init_once(void *foo)
726{
727 struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
728
729 inode_init_once(&ei->vfs_inode);
730}
731
732const struct file_operations hugetlbfs_file_operations = {
733 .read = hugetlbfs_read,
734 .mmap = hugetlbfs_file_mmap,
735 .fsync = noop_fsync,
736 .get_unmapped_area = hugetlb_get_unmapped_area,
737 .llseek = default_llseek,
738};
739
740static const struct inode_operations hugetlbfs_dir_inode_operations = {
741 .create = hugetlbfs_create,
742 .lookup = simple_lookup,
743 .link = simple_link,
744 .unlink = simple_unlink,
745 .symlink = hugetlbfs_symlink,
746 .mkdir = hugetlbfs_mkdir,
747 .rmdir = simple_rmdir,
748 .mknod = hugetlbfs_mknod,
749 .rename = simple_rename,
750 .setattr = hugetlbfs_setattr,
751};
752
753static const struct inode_operations hugetlbfs_inode_operations = {
754 .setattr = hugetlbfs_setattr,
755};
756
757static const struct super_operations hugetlbfs_ops = {
758 .alloc_inode = hugetlbfs_alloc_inode,
759 .destroy_inode = hugetlbfs_destroy_inode,
760 .evict_inode = hugetlbfs_evict_inode,
761 .statfs = hugetlbfs_statfs,
762 .put_super = hugetlbfs_put_super,
763 .show_options = generic_show_options,
764};
765
766static int
767hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
768{
769 char *p, *rest;
770 substring_t args[MAX_OPT_ARGS];
771 int option;
772 unsigned long long size = 0;
773 enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = NO_SIZE;
774
775 if (!options)
776 return 0;
777
778 while ((p = strsep(&options, ",")) != NULL) {
779 int token;
780 if (!*p)
781 continue;
782
783 token = match_token(p, tokens, args);
784 switch (token) {
785 case Opt_uid:
786 if (match_int(&args[0], &option))
787 goto bad_val;
788 pconfig->uid = option;
789 break;
790
791 case Opt_gid:
792 if (match_int(&args[0], &option))
793 goto bad_val;
794 pconfig->gid = option;
795 break;
796
797 case Opt_mode:
798 if (match_octal(&args[0], &option))
799 goto bad_val;
800 pconfig->mode = option & 01777U;
801 break;
802
803 case Opt_size: {
804 /* memparse() will accept a K/M/G without a digit */
805 if (!isdigit(*args[0].from))
806 goto bad_val;
807 size = memparse(args[0].from, &rest);
808 setsize = SIZE_STD;
809 if (*rest == '%')
810 setsize = SIZE_PERCENT;
811 break;
812 }
813
814 case Opt_nr_inodes:
815 /* memparse() will accept a K/M/G without a digit */
816 if (!isdigit(*args[0].from))
817 goto bad_val;
818 pconfig->nr_inodes = memparse(args[0].from, &rest);
819 break;
820
821 case Opt_pagesize: {
822 unsigned long ps;
823 ps = memparse(args[0].from, &rest);
824 pconfig->hstate = size_to_hstate(ps);
825 if (!pconfig->hstate) {
826 printk(KERN_ERR
827 "hugetlbfs: Unsupported page size %lu MB\n",
828 ps >> 20);
829 return -EINVAL;
830 }
831 break;
832 }
833
834 default:
835 printk(KERN_ERR "hugetlbfs: Bad mount option: \"%s\"\n",
836 p);
837 return -EINVAL;
838 break;
839 }
840 }
841
842 /* Do size after hstate is set up */
843 if (setsize > NO_SIZE) {
844 struct hstate *h = pconfig->hstate;
845 if (setsize == SIZE_PERCENT) {
846 size <<= huge_page_shift(h);
847 size *= h->max_huge_pages;
848 do_div(size, 100);
849 }
850 pconfig->nr_blocks = (size >> huge_page_shift(h));
851 }
852
853 return 0;
854
855bad_val:
856 printk(KERN_ERR "hugetlbfs: Bad value '%s' for mount option '%s'\n",
857 args[0].from, p);
858 return -EINVAL;
859}
860
861static int
862hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
863{
864 int ret;
865 struct hugetlbfs_config config;
866 struct hugetlbfs_sb_info *sbinfo;
867
868 save_mount_options(sb, data);
869
870 config.nr_blocks = -1; /* No limit on size by default */
871 config.nr_inodes = -1; /* No limit on number of inodes by default */
872 config.uid = current_fsuid();
873 config.gid = current_fsgid();
874 config.mode = 0755;
875 config.hstate = &default_hstate;
876 ret = hugetlbfs_parse_options(data, &config);
877 if (ret)
878 return ret;
879
880 sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL);
881 if (!sbinfo)
882 return -ENOMEM;
883 sb->s_fs_info = sbinfo;
884 sbinfo->hstate = config.hstate;
885 spin_lock_init(&sbinfo->stat_lock);
886 sbinfo->max_inodes = config.nr_inodes;
887 sbinfo->free_inodes = config.nr_inodes;
888 sbinfo->spool = NULL;
889 if (config.nr_blocks != -1) {
890 sbinfo->spool = hugepage_new_subpool(config.nr_blocks);
891 if (!sbinfo->spool)
892 goto out_free;
893 }
894 sb->s_maxbytes = MAX_LFS_FILESIZE;
895 sb->s_blocksize = huge_page_size(config.hstate);
896 sb->s_blocksize_bits = huge_page_shift(config.hstate);
897 sb->s_magic = HUGETLBFS_MAGIC;
898 sb->s_op = &hugetlbfs_ops;
899 sb->s_time_gran = 1;
900 sb->s_root = d_make_root(hugetlbfs_get_root(sb, &config));
901 if (!sb->s_root)
902 goto out_free;
903 return 0;
904out_free:
905 if (sbinfo->spool)
906 kfree(sbinfo->spool);
907 kfree(sbinfo);
908 return -ENOMEM;
909}
910
911static struct dentry *hugetlbfs_mount(struct file_system_type *fs_type,
912 int flags, const char *dev_name, void *data)
913{
914 return mount_nodev(fs_type, flags, data, hugetlbfs_fill_super);
915}
916
917static struct file_system_type hugetlbfs_fs_type = {
918 .name = "hugetlbfs",
919 .mount = hugetlbfs_mount,
920 .kill_sb = kill_litter_super,
921};
922
923static struct vfsmount *hugetlbfs_vfsmount;
924
925static int can_do_hugetlb_shm(void)
926{
927 return capable(CAP_IPC_LOCK) || in_group_p(sysctl_hugetlb_shm_group);
928}
929
930struct file *hugetlb_file_setup(const char *name, unsigned long addr,
931 size_t size, vm_flags_t acctflag,
932 struct user_struct **user, int creat_flags)
933{
934 int error = -ENOMEM;
935 struct file *file;
936 struct inode *inode;
937 struct path path;
938 struct dentry *root;
939 struct qstr quick_string;
940 struct hstate *hstate;
941 unsigned long num_pages;
942
943 *user = NULL;
944 if (!hugetlbfs_vfsmount)
945 return ERR_PTR(-ENOENT);
946
947 if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) {
948 *user = current_user();
949 if (user_shm_lock(size, *user)) {
950 task_lock(current);
951 printk_once(KERN_WARNING
952 "%s (%d): Using mlock ulimits for SHM_HUGETLB is deprecated\n",
953 current->comm, current->pid);
954 task_unlock(current);
955 } else {
956 *user = NULL;
957 return ERR_PTR(-EPERM);
958 }
959 }
960
961 root = hugetlbfs_vfsmount->mnt_root;
962 quick_string.name = name;
963 quick_string.len = strlen(quick_string.name);
964 quick_string.hash = 0;
965 path.dentry = d_alloc(root, &quick_string);
966 if (!path.dentry)
967 goto out_shm_unlock;
968
969 path.mnt = mntget(hugetlbfs_vfsmount);
970 error = -ENOSPC;
971 inode = hugetlbfs_get_inode(root->d_sb, NULL, S_IFREG | S_IRWXUGO, 0);
972 if (!inode)
973 goto out_dentry;
974
975 hstate = hstate_inode(inode);
976 size += addr & ~huge_page_mask(hstate);
977 num_pages = ALIGN(size, huge_page_size(hstate)) >>
978 huge_page_shift(hstate);
979 error = -ENOMEM;
980 if (hugetlb_reserve_pages(inode, 0, num_pages, NULL, acctflag))
981 goto out_inode;
982
983 d_instantiate(path.dentry, inode);
984 inode->i_size = size;
985 clear_nlink(inode);
986
987 error = -ENFILE;
988 file = alloc_file(&path, FMODE_WRITE | FMODE_READ,
989 &hugetlbfs_file_operations);
990 if (!file)
991 goto out_dentry; /* inode is already attached */
992
993 return file;
994
995out_inode:
996 iput(inode);
997out_dentry:
998 path_put(&path);
999out_shm_unlock:
1000 if (*user) {
1001 user_shm_unlock(size, *user);
1002 *user = NULL;
1003 }
1004 return ERR_PTR(error);
1005}
1006
1007static int __init init_hugetlbfs_fs(void)
1008{
1009 int error;
1010 struct vfsmount *vfsmount;
1011
1012 error = bdi_init(&hugetlbfs_backing_dev_info);
1013 if (error)
1014 return error;
1015
1016 error = -ENOMEM;
1017 hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
1018 sizeof(struct hugetlbfs_inode_info),
1019 0, 0, init_once);
1020 if (hugetlbfs_inode_cachep == NULL)
1021 goto out2;
1022
1023 error = register_filesystem(&hugetlbfs_fs_type);
1024 if (error)
1025 goto out;
1026
1027 vfsmount = kern_mount(&hugetlbfs_fs_type);
1028
1029 if (!IS_ERR(vfsmount)) {
1030 hugetlbfs_vfsmount = vfsmount;
1031 return 0;
1032 }
1033
1034 error = PTR_ERR(vfsmount);
1035
1036 out:
1037 kmem_cache_destroy(hugetlbfs_inode_cachep);
1038 out2:
1039 bdi_destroy(&hugetlbfs_backing_dev_info);
1040 return error;
1041}
1042
1043static void __exit exit_hugetlbfs_fs(void)
1044{
1045 kmem_cache_destroy(hugetlbfs_inode_cachep);
1046 kern_unmount(hugetlbfs_vfsmount);
1047 unregister_filesystem(&hugetlbfs_fs_type);
1048 bdi_destroy(&hugetlbfs_backing_dev_info);
1049}
1050
1051module_init(init_hugetlbfs_fs)
1052module_exit(exit_hugetlbfs_fs)
1053
1054MODULE_LICENSE("GPL");