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OMAP3: PM: move context-loss counting into OMAP PM
[linux-ginger.git] / fs / hugetlbfs / inode.c
blob87a1258953b8e387fe49367acfd6d2ff5c164ca1
1 /*
2 * hugetlbpage-backed filesystem. Based on ramfs.
3 *
4 * William Irwin, 2002
5 *
6 * Copyright (C) 2002 Linus Torvalds.
7 */
8
9 #include <linux/module.h>
10 #include <linux/thread_info.h>
11 #include <asm/current.h>
12 #include <linux/sched.h> /* remove ASAP */
13 #include <linux/fs.h>
14 #include <linux/mount.h>
15 #include <linux/file.h>
16 #include <linux/kernel.h>
17 #include <linux/writeback.h>
18 #include <linux/pagemap.h>
19 #include <linux/highmem.h>
20 #include <linux/init.h>
21 #include <linux/string.h>
22 #include <linux/capability.h>
23 #include <linux/ctype.h>
24 #include <linux/backing-dev.h>
25 #include <linux/hugetlb.h>
26 #include <linux/pagevec.h>
27 #include <linux/parser.h>
28 #include <linux/mman.h>
29 #include <linux/slab.h>
30 #include <linux/dnotify.h>
31 #include <linux/statfs.h>
32 #include <linux/security.h>
33 #include <linux/ima.h>
34 #include <linux/magic.h>
35
36 #include <asm/uaccess.h>
37
38 static const struct super_operations hugetlbfs_ops;
39 static const struct address_space_operations hugetlbfs_aops;
40 const struct file_operations hugetlbfs_file_operations;
41 static const struct inode_operations hugetlbfs_dir_inode_operations;
42 static const struct inode_operations hugetlbfs_inode_operations;
43
44 static struct backing_dev_info hugetlbfs_backing_dev_info = {
45 .name = "hugetlbfs",
46 .ra_pages = 0, /* No readahead */
47 .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
48 };
49
50 int sysctl_hugetlb_shm_group;
51
52 enum {
53 Opt_size, Opt_nr_inodes,
54 Opt_mode, Opt_uid, Opt_gid,
55 Opt_pagesize,
56 Opt_err,
57 };
58
59 static const match_table_t tokens = {
60 {Opt_size, "size=%s"},
61 {Opt_nr_inodes, "nr_inodes=%s"},
62 {Opt_mode, "mode=%o"},
63 {Opt_uid, "uid=%u"},
64 {Opt_gid, "gid=%u"},
65 {Opt_pagesize, "pagesize=%s"},
66 {Opt_err, NULL},
67 };
68
69 static void huge_pagevec_release(struct pagevec *pvec)
70 {
71 int i;
72
73 for (i = 0; i < pagevec_count(pvec); ++i)
74 put_page(pvec->pages[i]);
75
76 pagevec_reinit(pvec);
77 }
78
79 static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
80 {
81 struct inode *inode = file->f_path.dentry->d_inode;
82 loff_t len, vma_len;
83 int ret;
84 struct hstate *h = hstate_file(file);
85
86 /*
87 * vma address alignment (but not the pgoff alignment) has
88 * already been checked by prepare_hugepage_range. If you add
89 * any error returns here, do so after setting VM_HUGETLB, so
90 * is_vm_hugetlb_page tests below unmap_region go the right
91 * way when do_mmap_pgoff unwinds (may be important on powerpc
92 * and ia64).
93 */
94 vma->vm_flags |= VM_HUGETLB | VM_RESERVED;
95 vma->vm_ops = &hugetlb_vm_ops;
96
97 if (vma->vm_pgoff & ~(huge_page_mask(h) >> PAGE_SHIFT))
98 return -EINVAL;
99
100 vma_len = (loff_t)(vma->vm_end - vma->vm_start);
101
102 mutex_lock(&inode->i_mutex);
103 file_accessed(file);
104
105 ret = -ENOMEM;
106 len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
107
108 if (hugetlb_reserve_pages(inode,
109 vma->vm_pgoff >> huge_page_order(h),
110 len >> huge_page_shift(h), vma,
111 vma->vm_flags))
112 goto out;
113
114 ret = 0;
115 hugetlb_prefault_arch_hook(vma->vm_mm);
116 if (vma->vm_flags & VM_WRITE && inode->i_size < len)
117 inode->i_size = len;
118 out:
119 mutex_unlock(&inode->i_mutex);
120
121 return ret;
122 }
123
124 /*
125 * Called under down_write(mmap_sem).
126 */
127
128 #ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
129 static unsigned long
130 hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
131 unsigned long len, unsigned long pgoff, unsigned long flags)
132 {
133 struct mm_struct *mm = current->mm;
134 struct vm_area_struct *vma;
135 unsigned long start_addr;
136 struct hstate *h = hstate_file(file);
137
138 if (len & ~huge_page_mask(h))
139 return -EINVAL;
140 if (len > TASK_SIZE)
141 return -ENOMEM;
142
143 if (flags & MAP_FIXED) {
144 if (prepare_hugepage_range(file, addr, len))
145 return -EINVAL;
146 return addr;
147 }
148
149 if (addr) {
150 addr = ALIGN(addr, huge_page_size(h));
151 vma = find_vma(mm, addr);
152 if (TASK_SIZE - len >= addr &&
153 (!vma || addr + len <= vma->vm_start))
154 return addr;
155 }
156
157 start_addr = mm->free_area_cache;
158
159 if (len <= mm->cached_hole_size)
160 start_addr = TASK_UNMAPPED_BASE;
161
162 full_search:
163 addr = ALIGN(start_addr, huge_page_size(h));
164
165 for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
166 /* At this point: (!vma || addr < vma->vm_end). */
167 if (TASK_SIZE - len < addr) {
168 /*
169 * Start a new search - just in case we missed
170 * some holes.
171 */
172 if (start_addr != TASK_UNMAPPED_BASE) {
173 start_addr = TASK_UNMAPPED_BASE;
174 goto full_search;
175 }
176 return -ENOMEM;
177 }
178
179 if (!vma || addr + len <= vma->vm_start)
180 return addr;
181 addr = ALIGN(vma->vm_end, huge_page_size(h));
182 }
183 }
184 #endif
185
186 static int
187 hugetlbfs_read_actor(struct page *page, unsigned long offset,
188 char __user *buf, unsigned long count,
189 unsigned long size)
190 {
191 char *kaddr;
192 unsigned long left, copied = 0;
193 int i, chunksize;
194
195 if (size > count)
196 size = count;
197
198 /* Find which 4k chunk and offset with in that chunk */
199 i = offset >> PAGE_CACHE_SHIFT;
200 offset = offset & ~PAGE_CACHE_MASK;
201
202 while (size) {
203 chunksize = PAGE_CACHE_SIZE;
204 if (offset)
205 chunksize -= offset;
206 if (chunksize > size)
207 chunksize = size;
208 kaddr = kmap(&page[i]);
209 left = __copy_to_user(buf, kaddr + offset, chunksize);
210 kunmap(&page[i]);
211 if (left) {
212 copied += (chunksize - left);
213 break;
214 }
215 offset = 0;
216 size -= chunksize;
217 buf += chunksize;
218 copied += chunksize;
219 i++;
220 }
221 return copied ? copied : -EFAULT;
222 }
223
224 /*
225 * Support for read() - Find the page attached to f_mapping and copy out the
226 * data. Its *very* similar to do_generic_mapping_read(), we can't use that
227 * since it has PAGE_CACHE_SIZE assumptions.
228 */
229 static ssize_t hugetlbfs_read(struct file *filp, char __user *buf,
230 size_t len, loff_t *ppos)
231 {
232 struct hstate *h = hstate_file(filp);
233 struct address_space *mapping = filp->f_mapping;
234 struct inode *inode = mapping->host;
235 unsigned long index = *ppos >> huge_page_shift(h);
236 unsigned long offset = *ppos & ~huge_page_mask(h);
237 unsigned long end_index;
238 loff_t isize;
239 ssize_t retval = 0;
240
241 mutex_lock(&inode->i_mutex);
242
243 /* validate length */
244 if (len == 0)
245 goto out;
246
247 isize = i_size_read(inode);
248 if (!isize)
249 goto out;
250
251 end_index = (isize - 1) >> huge_page_shift(h);
252 for (;;) {
253 struct page *page;
254 unsigned long nr, ret;
255 int ra;
256
257 /* nr is the maximum number of bytes to copy from this page */
258 nr = huge_page_size(h);
259 if (index >= end_index) {
260 if (index > end_index)
261 goto out;
262 nr = ((isize - 1) & ~huge_page_mask(h)) + 1;
263 if (nr <= offset) {
264 goto out;
265 }
266 }
267 nr = nr - offset;
268
269 /* Find the page */
270 page = find_get_page(mapping, index);
271 if (unlikely(page == NULL)) {
272 /*
273 * We have a HOLE, zero out the user-buffer for the
274 * length of the hole or request.
275 */
276 ret = len < nr ? len : nr;
277 if (clear_user(buf, ret))
278 ra = -EFAULT;
279 else
280 ra = 0;
281 } else {
282 /*
283 * We have the page, copy it to user space buffer.
284 */
285 ra = hugetlbfs_read_actor(page, offset, buf, len, nr);
286 ret = ra;
287 }
288 if (ra < 0) {
289 if (retval == 0)
290 retval = ra;
291 if (page)
292 page_cache_release(page);
293 goto out;
294 }
295
296 offset += ret;
297 retval += ret;
298 len -= ret;
299 index += offset >> huge_page_shift(h);
300 offset &= ~huge_page_mask(h);
301
302 if (page)
303 page_cache_release(page);
304
305 /* short read or no more work */
306 if ((ret != nr) || (len == 0))
307 break;
308 }
309 out:
310 *ppos = ((loff_t)index << huge_page_shift(h)) + offset;
311 mutex_unlock(&inode->i_mutex);
312 return retval;
313 }
314
315 static int hugetlbfs_write_begin(struct file *file,
316 struct address_space *mapping,
317 loff_t pos, unsigned len, unsigned flags,
318 struct page **pagep, void **fsdata)
319 {
320 return -EINVAL;
321 }
322
323 static int hugetlbfs_write_end(struct file *file, struct address_space *mapping,
324 loff_t pos, unsigned len, unsigned copied,
325 struct page *page, void *fsdata)
326 {
327 BUG();
328 return -EINVAL;
329 }
330
331 static void truncate_huge_page(struct page *page)
332 {
333 cancel_dirty_page(page, /* No IO accounting for huge pages? */0);
334 ClearPageUptodate(page);
335 remove_from_page_cache(page);
336 put_page(page);
337 }
338
339 static void truncate_hugepages(struct inode *inode, loff_t lstart)
340 {
341 struct hstate *h = hstate_inode(inode);
342 struct address_space *mapping = &inode->i_data;
343 const pgoff_t start = lstart >> huge_page_shift(h);
344 struct pagevec pvec;
345 pgoff_t next;
346 int i, freed = 0;
347
348 pagevec_init(&pvec, 0);
349 next = start;
350 while (1) {
351 if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
352 if (next == start)
353 break;
354 next = start;
355 continue;
356 }
357
358 for (i = 0; i < pagevec_count(&pvec); ++i) {
359 struct page *page = pvec.pages[i];
360
361 lock_page(page);
362 if (page->index > next)
363 next = page->index;
364 ++next;
365 truncate_huge_page(page);
366 unlock_page(page);
367 freed++;
368 }
369 huge_pagevec_release(&pvec);
370 }
371 BUG_ON(!lstart && mapping->nrpages);
372 hugetlb_unreserve_pages(inode, start, freed);
373 }
374
375 static void hugetlbfs_delete_inode(struct inode *inode)
376 {
377 truncate_hugepages(inode, 0);
378 clear_inode(inode);
379 }
380
381 static void hugetlbfs_forget_inode(struct inode *inode) __releases(inode_lock)
382 {
383 if (generic_detach_inode(inode)) {
384 truncate_hugepages(inode, 0);
385 clear_inode(inode);
386 destroy_inode(inode);
387 }
388 }
389
390 static void hugetlbfs_drop_inode(struct inode *inode)
391 {
392 if (!inode->i_nlink)
393 generic_delete_inode(inode);
394 else
395 hugetlbfs_forget_inode(inode);
396 }
397
398 static inline void
399 hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff)
400 {
401 struct vm_area_struct *vma;
402 struct prio_tree_iter iter;
403
404 vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) {
405 unsigned long v_offset;
406
407 /*
408 * Can the expression below overflow on 32-bit arches?
409 * No, because the prio_tree returns us only those vmas
410 * which overlap the truncated area starting at pgoff,
411 * and no vma on a 32-bit arch can span beyond the 4GB.
412 */
413 if (vma->vm_pgoff < pgoff)
414 v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT;
415 else
416 v_offset = 0;
417
418 __unmap_hugepage_range(vma,
419 vma->vm_start + v_offset, vma->vm_end, NULL);
420 }
421 }
422
423 static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
424 {
425 pgoff_t pgoff;
426 struct address_space *mapping = inode->i_mapping;
427 struct hstate *h = hstate_inode(inode);
428
429 BUG_ON(offset & ~huge_page_mask(h));
430 pgoff = offset >> PAGE_SHIFT;
431
432 i_size_write(inode, offset);
433 spin_lock(&mapping->i_mmap_lock);
434 if (!prio_tree_empty(&mapping->i_mmap))
435 hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
436 spin_unlock(&mapping->i_mmap_lock);
437 truncate_hugepages(inode, offset);
438 return 0;
439 }
440
441 static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
442 {
443 struct inode *inode = dentry->d_inode;
444 struct hstate *h = hstate_inode(inode);
445 int error;
446 unsigned int ia_valid = attr->ia_valid;
447
448 BUG_ON(!inode);
449
450 error = inode_change_ok(inode, attr);
451 if (error)
452 goto out;
453
454 if (ia_valid & ATTR_SIZE) {
455 error = -EINVAL;
456 if (!(attr->ia_size & ~huge_page_mask(h)))
457 error = hugetlb_vmtruncate(inode, attr->ia_size);
458 if (error)
459 goto out;
460 attr->ia_valid &= ~ATTR_SIZE;
461 }
462 error = inode_setattr(inode, attr);
463 out:
464 return error;
465 }
466
467 static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid,
468 gid_t gid, int mode, dev_t dev)
469 {
470 struct inode *inode;
471
472 inode = new_inode(sb);
473 if (inode) {
474 struct hugetlbfs_inode_info *info;
475 inode->i_mode = mode;
476 inode->i_uid = uid;
477 inode->i_gid = gid;
478 inode->i_mapping->a_ops = &hugetlbfs_aops;
479 inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info;
480 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
481 INIT_LIST_HEAD(&inode->i_mapping->private_list);
482 info = HUGETLBFS_I(inode);
483 /*
484 * The policy is initialized here even if we are creating a
485 * private inode because initialization simply creates an
486 * an empty rb tree and calls spin_lock_init(), later when we
487 * call mpol_free_shared_policy() it will just return because
488 * the rb tree will still be empty.
489 */
490 mpol_shared_policy_init(&info->policy, NULL);
491 switch (mode & S_IFMT) {
492 default:
493 init_special_inode(inode, mode, dev);
494 break;
495 case S_IFREG:
496 inode->i_op = &hugetlbfs_inode_operations;
497 inode->i_fop = &hugetlbfs_file_operations;
498 break;
499 case S_IFDIR:
500 inode->i_op = &hugetlbfs_dir_inode_operations;
501 inode->i_fop = &simple_dir_operations;
502
503 /* directory inodes start off with i_nlink == 2 (for "." entry) */
504 inc_nlink(inode);
505 break;
506 case S_IFLNK:
507 inode->i_op = &page_symlink_inode_operations;
508 break;
509 }
510 }
511 return inode;
512 }
513
514 /*
515 * File creation. Allocate an inode, and we're done..
516 */
517 static int hugetlbfs_mknod(struct inode *dir,
518 struct dentry *dentry, int mode, dev_t dev)
519 {
520 struct inode *inode;
521 int error = -ENOSPC;
522 gid_t gid;
523
524 if (dir->i_mode & S_ISGID) {
525 gid = dir->i_gid;
526 if (S_ISDIR(mode))
527 mode |= S_ISGID;
528 } else {
529 gid = current_fsgid();
530 }
531 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), gid, mode, dev);
532 if (inode) {
533 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
534 d_instantiate(dentry, inode);
535 dget(dentry); /* Extra count - pin the dentry in core */
536 error = 0;
537 }
538 return error;
539 }
540
541 static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
542 {
543 int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0);
544 if (!retval)
545 inc_nlink(dir);
546 return retval;
547 }
548
549 static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd)
550 {
551 return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0);
552 }
553
554 static int hugetlbfs_symlink(struct inode *dir,
555 struct dentry *dentry, const char *symname)
556 {
557 struct inode *inode;
558 int error = -ENOSPC;
559 gid_t gid;
560
561 if (dir->i_mode & S_ISGID)
562 gid = dir->i_gid;
563 else
564 gid = current_fsgid();
565
566 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(),
567 gid, S_IFLNK|S_IRWXUGO, 0);
568 if (inode) {
569 int l = strlen(symname)+1;
570 error = page_symlink(inode, symname, l);
571 if (!error) {
572 d_instantiate(dentry, inode);
573 dget(dentry);
574 } else
575 iput(inode);
576 }
577 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
578
579 return error;
580 }
581
582 /*
583 * mark the head page dirty
584 */
585 static int hugetlbfs_set_page_dirty(struct page *page)
586 {
587 struct page *head = compound_head(page);
588
589 SetPageDirty(head);
590 return 0;
591 }
592
593 static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
594 {
595 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
596 struct hstate *h = hstate_inode(dentry->d_inode);
597
598 buf->f_type = HUGETLBFS_MAGIC;
599 buf->f_bsize = huge_page_size(h);
600 if (sbinfo) {
601 spin_lock(&sbinfo->stat_lock);
602 /* If no limits set, just report 0 for max/free/used
603 * blocks, like simple_statfs() */
604 if (sbinfo->max_blocks >= 0) {
605 buf->f_blocks = sbinfo->max_blocks;
606 buf->f_bavail = buf->f_bfree = sbinfo->free_blocks;
607 buf->f_files = sbinfo->max_inodes;
608 buf->f_ffree = sbinfo->free_inodes;
609 }
610 spin_unlock(&sbinfo->stat_lock);
611 }
612 buf->f_namelen = NAME_MAX;
613 return 0;
614 }
615
616 static void hugetlbfs_put_super(struct super_block *sb)
617 {
618 struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb);
619
620 if (sbi) {
621 sb->s_fs_info = NULL;
622 kfree(sbi);
623 }
624 }
625
626 static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo)
627 {
628 if (sbinfo->free_inodes >= 0) {
629 spin_lock(&sbinfo->stat_lock);
630 if (unlikely(!sbinfo->free_inodes)) {
631 spin_unlock(&sbinfo->stat_lock);
632 return 0;
633 }
634 sbinfo->free_inodes--;
635 spin_unlock(&sbinfo->stat_lock);
636 }
637
638 return 1;
639 }
640
641 static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
642 {
643 if (sbinfo->free_inodes >= 0) {
644 spin_lock(&sbinfo->stat_lock);
645 sbinfo->free_inodes++;
646 spin_unlock(&sbinfo->stat_lock);
647 }
648 }
649
650
651 static struct kmem_cache *hugetlbfs_inode_cachep;
652
653 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
654 {
655 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
656 struct hugetlbfs_inode_info *p;
657
658 if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
659 return NULL;
660 p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL);
661 if (unlikely(!p)) {
662 hugetlbfs_inc_free_inodes(sbinfo);
663 return NULL;
664 }
665 return &p->vfs_inode;
666 }
667
668 static void hugetlbfs_destroy_inode(struct inode *inode)
669 {
670 hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
671 mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
672 kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
673 }
674
675 static const struct address_space_operations hugetlbfs_aops = {
676 .write_begin = hugetlbfs_write_begin,
677 .write_end = hugetlbfs_write_end,
678 .set_page_dirty = hugetlbfs_set_page_dirty,
679 };
680
681
682 static void init_once(void *foo)
683 {
684 struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
685
686 inode_init_once(&ei->vfs_inode);
687 }
688
689 const struct file_operations hugetlbfs_file_operations = {
690 .read = hugetlbfs_read,
691 .mmap = hugetlbfs_file_mmap,
692 .fsync = simple_sync_file,
693 .get_unmapped_area = hugetlb_get_unmapped_area,
694 };
695
696 static const struct inode_operations hugetlbfs_dir_inode_operations = {
697 .create = hugetlbfs_create,
698 .lookup = simple_lookup,
699 .link = simple_link,
700 .unlink = simple_unlink,
701 .symlink = hugetlbfs_symlink,
702 .mkdir = hugetlbfs_mkdir,
703 .rmdir = simple_rmdir,
704 .mknod = hugetlbfs_mknod,
705 .rename = simple_rename,
706 .setattr = hugetlbfs_setattr,
707 };
708
709 static const struct inode_operations hugetlbfs_inode_operations = {
710 .setattr = hugetlbfs_setattr,
711 };
712
713 static const struct super_operations hugetlbfs_ops = {
714 .alloc_inode = hugetlbfs_alloc_inode,
715 .destroy_inode = hugetlbfs_destroy_inode,
716 .statfs = hugetlbfs_statfs,
717 .delete_inode = hugetlbfs_delete_inode,
718 .drop_inode = hugetlbfs_drop_inode,
719 .put_super = hugetlbfs_put_super,
720 .show_options = generic_show_options,
721 };
722
723 static int
724 hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
725 {
726 char *p, *rest;
727 substring_t args[MAX_OPT_ARGS];
728 int option;
729 unsigned long long size = 0;
730 enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = NO_SIZE;
731
732 if (!options)
733 return 0;
734
735 while ((p = strsep(&options, ",")) != NULL) {
736 int token;
737 if (!*p)
738 continue;
739
740 token = match_token(p, tokens, args);
741 switch (token) {
742 case Opt_uid:
743 if (match_int(&args[0], &option))
744 goto bad_val;
745 pconfig->uid = option;
746 break;
747
748 case Opt_gid:
749 if (match_int(&args[0], &option))
750 goto bad_val;
751 pconfig->gid = option;
752 break;
753
754 case Opt_mode:
755 if (match_octal(&args[0], &option))
756 goto bad_val;
757 pconfig->mode = option & 01777U;
758 break;
759
760 case Opt_size: {
761 /* memparse() will accept a K/M/G without a digit */
762 if (!isdigit(*args[0].from))
763 goto bad_val;
764 size = memparse(args[0].from, &rest);
765 setsize = SIZE_STD;
766 if (*rest == '%')
767 setsize = SIZE_PERCENT;
768 break;
769 }
770
771 case Opt_nr_inodes:
772 /* memparse() will accept a K/M/G without a digit */
773 if (!isdigit(*args[0].from))
774 goto bad_val;
775 pconfig->nr_inodes = memparse(args[0].from, &rest);
776 break;
777
778 case Opt_pagesize: {
779 unsigned long ps;
780 ps = memparse(args[0].from, &rest);
781 pconfig->hstate = size_to_hstate(ps);
782 if (!pconfig->hstate) {
783 printk(KERN_ERR
784 "hugetlbfs: Unsupported page size %lu MB\n",
785 ps >> 20);
786 return -EINVAL;
787 }
788 break;
789 }
790
791 default:
792 printk(KERN_ERR "hugetlbfs: Bad mount option: \"%s\"\n",
793 p);
794 return -EINVAL;
795 break;
796 }
797 }
798
799 /* Do size after hstate is set up */
800 if (setsize > NO_SIZE) {
801 struct hstate *h = pconfig->hstate;
802 if (setsize == SIZE_PERCENT) {
803 size <<= huge_page_shift(h);
804 size *= h->max_huge_pages;
805 do_div(size, 100);
806 }
807 pconfig->nr_blocks = (size >> huge_page_shift(h));
808 }
809
810 return 0;
811
812 bad_val:
813 printk(KERN_ERR "hugetlbfs: Bad value '%s' for mount option '%s'\n",
814 args[0].from, p);
815 return -EINVAL;
816 }
817
818 static int
819 hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
820 {
821 struct inode * inode;
822 struct dentry * root;
823 int ret;
824 struct hugetlbfs_config config;
825 struct hugetlbfs_sb_info *sbinfo;
826
827 save_mount_options(sb, data);
828
829 config.nr_blocks = -1; /* No limit on size by default */
830 config.nr_inodes = -1; /* No limit on number of inodes by default */
831 config.uid = current_fsuid();
832 config.gid = current_fsgid();
833 config.mode = 0755;
834 config.hstate = &default_hstate;
835 ret = hugetlbfs_parse_options(data, &config);
836 if (ret)
837 return ret;
838
839 sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL);
840 if (!sbinfo)
841 return -ENOMEM;
842 sb->s_fs_info = sbinfo;
843 sbinfo->hstate = config.hstate;
844 spin_lock_init(&sbinfo->stat_lock);
845 sbinfo->max_blocks = config.nr_blocks;
846 sbinfo->free_blocks = config.nr_blocks;
847 sbinfo->max_inodes = config.nr_inodes;
848 sbinfo->free_inodes = config.nr_inodes;
849 sb->s_maxbytes = MAX_LFS_FILESIZE;
850 sb->s_blocksize = huge_page_size(config.hstate);
851 sb->s_blocksize_bits = huge_page_shift(config.hstate);
852 sb->s_magic = HUGETLBFS_MAGIC;
853 sb->s_op = &hugetlbfs_ops;
854 sb->s_time_gran = 1;
855 inode = hugetlbfs_get_inode(sb, config.uid, config.gid,
856 S_IFDIR | config.mode, 0);
857 if (!inode)
858 goto out_free;
859
860 root = d_alloc_root(inode);
861 if (!root) {
862 iput(inode);
863 goto out_free;
864 }
865 sb->s_root = root;
866 return 0;
867 out_free:
868 kfree(sbinfo);
869 return -ENOMEM;
870 }
871
872 int hugetlb_get_quota(struct address_space *mapping, long delta)
873 {
874 int ret = 0;
875 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb);
876
877 if (sbinfo->free_blocks > -1) {
878 spin_lock(&sbinfo->stat_lock);
879 if (sbinfo->free_blocks - delta >= 0)
880 sbinfo->free_blocks -= delta;
881 else
882 ret = -ENOMEM;
883 spin_unlock(&sbinfo->stat_lock);
884 }
885
886 return ret;
887 }
888
889 void hugetlb_put_quota(struct address_space *mapping, long delta)
890 {
891 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb);
892
893 if (sbinfo->free_blocks > -1) {
894 spin_lock(&sbinfo->stat_lock);
895 sbinfo->free_blocks += delta;
896 spin_unlock(&sbinfo->stat_lock);
897 }
898 }
899
900 static int hugetlbfs_get_sb(struct file_system_type *fs_type,
901 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
902 {
903 return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super, mnt);
904 }
905
906 static struct file_system_type hugetlbfs_fs_type = {
907 .name = "hugetlbfs",
908 .get_sb = hugetlbfs_get_sb,
909 .kill_sb = kill_litter_super,
910 };
911
912 static struct vfsmount *hugetlbfs_vfsmount;
913
914 static int can_do_hugetlb_shm(void)
915 {
916 return capable(CAP_IPC_LOCK) || in_group_p(sysctl_hugetlb_shm_group);
917 }
918
919 struct file *hugetlb_file_setup(const char *name, size_t size, int acctflag,
920 struct user_struct **user, int creat_flags)
921 {
922 int error = -ENOMEM;
923 struct file *file;
924 struct inode *inode;
925 struct dentry *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 dentry = d_alloc(root, &quick_string);
948 if (!dentry)
949 goto out_shm_unlock;
950
951 error = -ENOSPC;
952 inode = hugetlbfs_get_inode(root->d_sb, current_fsuid(),
953 current_fsgid(), S_IFREG | S_IRWXUGO, 0);
954 if (!inode)
955 goto out_dentry;
956
957 error = -ENOMEM;
958 if (hugetlb_reserve_pages(inode, 0,
959 size >> huge_page_shift(hstate_inode(inode)), NULL,
960 acctflag))
961 goto out_inode;
962
963 d_instantiate(dentry, inode);
964 inode->i_size = size;
965 inode->i_nlink = 0;
966
967 error = -ENFILE;
968 file = alloc_file(hugetlbfs_vfsmount, dentry,
969 FMODE_WRITE | FMODE_READ,
970 &hugetlbfs_file_operations);
971 if (!file)
972 goto out_dentry; /* inode is already attached */
973 ima_counts_get(file);
974
975 return file;
976
977 out_inode:
978 iput(inode);
979 out_dentry:
980 dput(dentry);
981 out_shm_unlock:
982 if (*user) {
983 user_shm_unlock(size, *user);
984 *user = NULL;
985 }
986 return ERR_PTR(error);
987 }
988
989 static int __init init_hugetlbfs_fs(void)
990 {
991 int error;
992 struct vfsmount *vfsmount;
993
994 error = bdi_init(&hugetlbfs_backing_dev_info);
995 if (error)
996 return error;
997
998 hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
999 sizeof(struct hugetlbfs_inode_info),
1000 0, 0, init_once);
1001 if (hugetlbfs_inode_cachep == NULL)
1002 goto out2;
1003
1004 error = register_filesystem(&hugetlbfs_fs_type);
1005 if (error)
1006 goto out;
1007
1008 vfsmount = kern_mount(&hugetlbfs_fs_type);
1009
1010 if (!IS_ERR(vfsmount)) {
1011 hugetlbfs_vfsmount = vfsmount;
1012 return 0;
1013 }
1014
1015 error = PTR_ERR(vfsmount);
1016
1017 out:
1018 if (error)
1019 kmem_cache_destroy(hugetlbfs_inode_cachep);
1020 out2:
1021 bdi_destroy(&hugetlbfs_backing_dev_info);
1022 return error;
1023 }
1024
1025 static void __exit exit_hugetlbfs_fs(void)
1026 {
1027 kmem_cache_destroy(hugetlbfs_inode_cachep);
1028 unregister_filesystem(&hugetlbfs_fs_type);
1029 bdi_destroy(&hugetlbfs_backing_dev_info);
1030 }
1031
1032 module_init(init_hugetlbfs_fs)
1033 module_exit(exit_hugetlbfs_fs)
1034
1035 MODULE_LICENSE("GPL");
Linux for Ginger Game Console