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davinci: DM644x: rename board file
[linux-ginger.git] / fs / hugetlbfs / inode.c
blob153d9681192b6dcc5f2d29094d4582ac75e94ff6
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
34 #include <asm/uaccess.h>
35
36 /* some random number */
37 #define HUGETLBFS_MAGIC 0x958458f6
38
39 static const struct super_operations hugetlbfs_ops;
40 static const struct address_space_operations hugetlbfs_aops;
41 const struct file_operations hugetlbfs_file_operations;
42 static const struct inode_operations hugetlbfs_dir_inode_operations;
43 static const struct inode_operations hugetlbfs_inode_operations;
44
45 static struct backing_dev_info hugetlbfs_backing_dev_info = {
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 /*
316 * Read a page. Again trivial. If it didn't already exist
317 * in the page cache, it is zero-filled.
318 */
319 static int hugetlbfs_readpage(struct file *file, struct page * page)
320 {
321 unlock_page(page);
322 return -EINVAL;
323 }
324
325 static int hugetlbfs_write_begin(struct file *file,
326 struct address_space *mapping,
327 loff_t pos, unsigned len, unsigned flags,
328 struct page **pagep, void **fsdata)
329 {
330 return -EINVAL;
331 }
332
333 static int hugetlbfs_write_end(struct file *file, struct address_space *mapping,
334 loff_t pos, unsigned len, unsigned copied,
335 struct page *page, void *fsdata)
336 {
337 BUG();
338 return -EINVAL;
339 }
340
341 static void truncate_huge_page(struct page *page)
342 {
343 cancel_dirty_page(page, /* No IO accounting for huge pages? */0);
344 ClearPageUptodate(page);
345 remove_from_page_cache(page);
346 put_page(page);
347 }
348
349 static void truncate_hugepages(struct inode *inode, loff_t lstart)
350 {
351 struct hstate *h = hstate_inode(inode);
352 struct address_space *mapping = &inode->i_data;
353 const pgoff_t start = lstart >> huge_page_shift(h);
354 struct pagevec pvec;
355 pgoff_t next;
356 int i, freed = 0;
357
358 pagevec_init(&pvec, 0);
359 next = start;
360 while (1) {
361 if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
362 if (next == start)
363 break;
364 next = start;
365 continue;
366 }
367
368 for (i = 0; i < pagevec_count(&pvec); ++i) {
369 struct page *page = pvec.pages[i];
370
371 lock_page(page);
372 if (page->index > next)
373 next = page->index;
374 ++next;
375 truncate_huge_page(page);
376 unlock_page(page);
377 freed++;
378 }
379 huge_pagevec_release(&pvec);
380 }
381 BUG_ON(!lstart && mapping->nrpages);
382 hugetlb_unreserve_pages(inode, start, freed);
383 }
384
385 static void hugetlbfs_delete_inode(struct inode *inode)
386 {
387 truncate_hugepages(inode, 0);
388 clear_inode(inode);
389 }
390
391 static void hugetlbfs_forget_inode(struct inode *inode) __releases(inode_lock)
392 {
393 struct super_block *sb = inode->i_sb;
394
395 if (!hlist_unhashed(&inode->i_hash)) {
396 if (!(inode->i_state & (I_DIRTY|I_SYNC)))
397 list_move(&inode->i_list, &inode_unused);
398 inodes_stat.nr_unused++;
399 if (!sb || (sb->s_flags & MS_ACTIVE)) {
400 spin_unlock(&inode_lock);
401 return;
402 }
403 inode->i_state |= I_WILL_FREE;
404 spin_unlock(&inode_lock);
405 /*
406 * write_inode_now is a noop as we set BDI_CAP_NO_WRITEBACK
407 * in our backing_dev_info.
408 */
409 write_inode_now(inode, 1);
410 spin_lock(&inode_lock);
411 inode->i_state &= ~I_WILL_FREE;
412 inodes_stat.nr_unused--;
413 hlist_del_init(&inode->i_hash);
414 }
415 list_del_init(&inode->i_list);
416 list_del_init(&inode->i_sb_list);
417 inode->i_state |= I_FREEING;
418 inodes_stat.nr_inodes--;
419 spin_unlock(&inode_lock);
420 truncate_hugepages(inode, 0);
421 clear_inode(inode);
422 destroy_inode(inode);
423 }
424
425 static void hugetlbfs_drop_inode(struct inode *inode)
426 {
427 if (!inode->i_nlink)
428 generic_delete_inode(inode);
429 else
430 hugetlbfs_forget_inode(inode);
431 }
432
433 static inline void
434 hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff)
435 {
436 struct vm_area_struct *vma;
437 struct prio_tree_iter iter;
438
439 vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) {
440 unsigned long v_offset;
441
442 /*
443 * Can the expression below overflow on 32-bit arches?
444 * No, because the prio_tree returns us only those vmas
445 * which overlap the truncated area starting at pgoff,
446 * and no vma on a 32-bit arch can span beyond the 4GB.
447 */
448 if (vma->vm_pgoff < pgoff)
449 v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT;
450 else
451 v_offset = 0;
452
453 __unmap_hugepage_range(vma,
454 vma->vm_start + v_offset, vma->vm_end, NULL);
455 }
456 }
457
458 static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
459 {
460 pgoff_t pgoff;
461 struct address_space *mapping = inode->i_mapping;
462 struct hstate *h = hstate_inode(inode);
463
464 BUG_ON(offset & ~huge_page_mask(h));
465 pgoff = offset >> PAGE_SHIFT;
466
467 i_size_write(inode, offset);
468 spin_lock(&mapping->i_mmap_lock);
469 if (!prio_tree_empty(&mapping->i_mmap))
470 hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
471 spin_unlock(&mapping->i_mmap_lock);
472 truncate_hugepages(inode, offset);
473 return 0;
474 }
475
476 static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
477 {
478 struct inode *inode = dentry->d_inode;
479 struct hstate *h = hstate_inode(inode);
480 int error;
481 unsigned int ia_valid = attr->ia_valid;
482
483 BUG_ON(!inode);
484
485 error = inode_change_ok(inode, attr);
486 if (error)
487 goto out;
488
489 if (ia_valid & ATTR_SIZE) {
490 error = -EINVAL;
491 if (!(attr->ia_size & ~huge_page_mask(h)))
492 error = hugetlb_vmtruncate(inode, attr->ia_size);
493 if (error)
494 goto out;
495 attr->ia_valid &= ~ATTR_SIZE;
496 }
497 error = inode_setattr(inode, attr);
498 out:
499 return error;
500 }
501
502 static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid,
503 gid_t gid, int mode, dev_t dev)
504 {
505 struct inode *inode;
506
507 inode = new_inode(sb);
508 if (inode) {
509 struct hugetlbfs_inode_info *info;
510 inode->i_mode = mode;
511 inode->i_uid = uid;
512 inode->i_gid = gid;
513 inode->i_mapping->a_ops = &hugetlbfs_aops;
514 inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info;
515 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
516 INIT_LIST_HEAD(&inode->i_mapping->private_list);
517 info = HUGETLBFS_I(inode);
518 mpol_shared_policy_init(&info->policy, NULL);
519 switch (mode & S_IFMT) {
520 default:
521 init_special_inode(inode, mode, dev);
522 break;
523 case S_IFREG:
524 inode->i_op = &hugetlbfs_inode_operations;
525 inode->i_fop = &hugetlbfs_file_operations;
526 break;
527 case S_IFDIR:
528 inode->i_op = &hugetlbfs_dir_inode_operations;
529 inode->i_fop = &simple_dir_operations;
530
531 /* directory inodes start off with i_nlink == 2 (for "." entry) */
532 inc_nlink(inode);
533 break;
534 case S_IFLNK:
535 inode->i_op = &page_symlink_inode_operations;
536 break;
537 }
538 }
539 return inode;
540 }
541
542 /*
543 * File creation. Allocate an inode, and we're done..
544 */
545 static int hugetlbfs_mknod(struct inode *dir,
546 struct dentry *dentry, int mode, dev_t dev)
547 {
548 struct inode *inode;
549 int error = -ENOSPC;
550 gid_t gid;
551
552 if (dir->i_mode & S_ISGID) {
553 gid = dir->i_gid;
554 if (S_ISDIR(mode))
555 mode |= S_ISGID;
556 } else {
557 gid = current_fsgid();
558 }
559 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), gid, mode, dev);
560 if (inode) {
561 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
562 d_instantiate(dentry, inode);
563 dget(dentry); /* Extra count - pin the dentry in core */
564 error = 0;
565 }
566 return error;
567 }
568
569 static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
570 {
571 int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0);
572 if (!retval)
573 inc_nlink(dir);
574 return retval;
575 }
576
577 static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd)
578 {
579 return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0);
580 }
581
582 static int hugetlbfs_symlink(struct inode *dir,
583 struct dentry *dentry, const char *symname)
584 {
585 struct inode *inode;
586 int error = -ENOSPC;
587 gid_t gid;
588
589 if (dir->i_mode & S_ISGID)
590 gid = dir->i_gid;
591 else
592 gid = current_fsgid();
593
594 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(),
595 gid, S_IFLNK|S_IRWXUGO, 0);
596 if (inode) {
597 int l = strlen(symname)+1;
598 error = page_symlink(inode, symname, l);
599 if (!error) {
600 d_instantiate(dentry, inode);
601 dget(dentry);
602 } else
603 iput(inode);
604 }
605 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
606
607 return error;
608 }
609
610 /*
611 * mark the head page dirty
612 */
613 static int hugetlbfs_set_page_dirty(struct page *page)
614 {
615 struct page *head = compound_head(page);
616
617 SetPageDirty(head);
618 return 0;
619 }
620
621 static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
622 {
623 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
624 struct hstate *h = hstate_inode(dentry->d_inode);
625
626 buf->f_type = HUGETLBFS_MAGIC;
627 buf->f_bsize = huge_page_size(h);
628 if (sbinfo) {
629 spin_lock(&sbinfo->stat_lock);
630 /* If no limits set, just report 0 for max/free/used
631 * blocks, like simple_statfs() */
632 if (sbinfo->max_blocks >= 0) {
633 buf->f_blocks = sbinfo->max_blocks;
634 buf->f_bavail = buf->f_bfree = sbinfo->free_blocks;
635 buf->f_files = sbinfo->max_inodes;
636 buf->f_ffree = sbinfo->free_inodes;
637 }
638 spin_unlock(&sbinfo->stat_lock);
639 }
640 buf->f_namelen = NAME_MAX;
641 return 0;
642 }
643
644 static void hugetlbfs_put_super(struct super_block *sb)
645 {
646 struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb);
647
648 if (sbi) {
649 sb->s_fs_info = NULL;
650 kfree(sbi);
651 }
652 }
653
654 static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo)
655 {
656 if (sbinfo->free_inodes >= 0) {
657 spin_lock(&sbinfo->stat_lock);
658 if (unlikely(!sbinfo->free_inodes)) {
659 spin_unlock(&sbinfo->stat_lock);
660 return 0;
661 }
662 sbinfo->free_inodes--;
663 spin_unlock(&sbinfo->stat_lock);
664 }
665
666 return 1;
667 }
668
669 static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
670 {
671 if (sbinfo->free_inodes >= 0) {
672 spin_lock(&sbinfo->stat_lock);
673 sbinfo->free_inodes++;
674 spin_unlock(&sbinfo->stat_lock);
675 }
676 }
677
678
679 static struct kmem_cache *hugetlbfs_inode_cachep;
680
681 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
682 {
683 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
684 struct hugetlbfs_inode_info *p;
685
686 if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
687 return NULL;
688 p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL);
689 if (unlikely(!p)) {
690 hugetlbfs_inc_free_inodes(sbinfo);
691 return NULL;
692 }
693 return &p->vfs_inode;
694 }
695
696 static void hugetlbfs_destroy_inode(struct inode *inode)
697 {
698 hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
699 mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
700 kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
701 }
702
703 static const struct address_space_operations hugetlbfs_aops = {
704 .readpage = hugetlbfs_readpage,
705 .write_begin = hugetlbfs_write_begin,
706 .write_end = hugetlbfs_write_end,
707 .set_page_dirty = hugetlbfs_set_page_dirty,
708 };
709
710
711 static void init_once(void *foo)
712 {
713 struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
714
715 inode_init_once(&ei->vfs_inode);
716 }
717
718 const struct file_operations hugetlbfs_file_operations = {
719 .read = hugetlbfs_read,
720 .mmap = hugetlbfs_file_mmap,
721 .fsync = simple_sync_file,
722 .get_unmapped_area = hugetlb_get_unmapped_area,
723 };
724
725 static const struct inode_operations hugetlbfs_dir_inode_operations = {
726 .create = hugetlbfs_create,
727 .lookup = simple_lookup,
728 .link = simple_link,
729 .unlink = simple_unlink,
730 .symlink = hugetlbfs_symlink,
731 .mkdir = hugetlbfs_mkdir,
732 .rmdir = simple_rmdir,
733 .mknod = hugetlbfs_mknod,
734 .rename = simple_rename,
735 .setattr = hugetlbfs_setattr,
736 };
737
738 static const struct inode_operations hugetlbfs_inode_operations = {
739 .setattr = hugetlbfs_setattr,
740 };
741
742 static const struct super_operations hugetlbfs_ops = {
743 .alloc_inode = hugetlbfs_alloc_inode,
744 .destroy_inode = hugetlbfs_destroy_inode,
745 .statfs = hugetlbfs_statfs,
746 .delete_inode = hugetlbfs_delete_inode,
747 .drop_inode = hugetlbfs_drop_inode,
748 .put_super = hugetlbfs_put_super,
749 .show_options = generic_show_options,
750 };
751
752 static int
753 hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
754 {
755 char *p, *rest;
756 substring_t args[MAX_OPT_ARGS];
757 int option;
758 unsigned long long size = 0;
759 enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = NO_SIZE;
760
761 if (!options)
762 return 0;
763
764 while ((p = strsep(&options, ",")) != NULL) {
765 int token;
766 if (!*p)
767 continue;
768
769 token = match_token(p, tokens, args);
770 switch (token) {
771 case Opt_uid:
772 if (match_int(&args[0], &option))
773 goto bad_val;
774 pconfig->uid = option;
775 break;
776
777 case Opt_gid:
778 if (match_int(&args[0], &option))
779 goto bad_val;
780 pconfig->gid = option;
781 break;
782
783 case Opt_mode:
784 if (match_octal(&args[0], &option))
785 goto bad_val;
786 pconfig->mode = option & 01777U;
787 break;
788
789 case Opt_size: {
790 /* memparse() will accept a K/M/G without a digit */
791 if (!isdigit(*args[0].from))
792 goto bad_val;
793 size = memparse(args[0].from, &rest);
794 setsize = SIZE_STD;
795 if (*rest == '%')
796 setsize = SIZE_PERCENT;
797 break;
798 }
799
800 case Opt_nr_inodes:
801 /* memparse() will accept a K/M/G without a digit */
802 if (!isdigit(*args[0].from))
803 goto bad_val;
804 pconfig->nr_inodes = memparse(args[0].from, &rest);
805 break;
806
807 case Opt_pagesize: {
808 unsigned long ps;
809 ps = memparse(args[0].from, &rest);
810 pconfig->hstate = size_to_hstate(ps);
811 if (!pconfig->hstate) {
812 printk(KERN_ERR
813 "hugetlbfs: Unsupported page size %lu MB\n",
814 ps >> 20);
815 return -EINVAL;
816 }
817 break;
818 }
819
820 default:
821 printk(KERN_ERR "hugetlbfs: Bad mount option: \"%s\"\n",
822 p);
823 return -EINVAL;
824 break;
825 }
826 }
827
828 /* Do size after hstate is set up */
829 if (setsize > NO_SIZE) {
830 struct hstate *h = pconfig->hstate;
831 if (setsize == SIZE_PERCENT) {
832 size <<= huge_page_shift(h);
833 size *= h->max_huge_pages;
834 do_div(size, 100);
835 }
836 pconfig->nr_blocks = (size >> huge_page_shift(h));
837 }
838
839 return 0;
840
841 bad_val:
842 printk(KERN_ERR "hugetlbfs: Bad value '%s' for mount option '%s'\n",
843 args[0].from, p);
844 return -EINVAL;
845 }
846
847 static int
848 hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
849 {
850 struct inode * inode;
851 struct dentry * root;
852 int ret;
853 struct hugetlbfs_config config;
854 struct hugetlbfs_sb_info *sbinfo;
855
856 save_mount_options(sb, data);
857
858 config.nr_blocks = -1; /* No limit on size by default */
859 config.nr_inodes = -1; /* No limit on number of inodes by default */
860 config.uid = current_fsuid();
861 config.gid = current_fsgid();
862 config.mode = 0755;
863 config.hstate = &default_hstate;
864 ret = hugetlbfs_parse_options(data, &config);
865 if (ret)
866 return ret;
867
868 sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL);
869 if (!sbinfo)
870 return -ENOMEM;
871 sb->s_fs_info = sbinfo;
872 sbinfo->hstate = config.hstate;
873 spin_lock_init(&sbinfo->stat_lock);
874 sbinfo->max_blocks = config.nr_blocks;
875 sbinfo->free_blocks = config.nr_blocks;
876 sbinfo->max_inodes = config.nr_inodes;
877 sbinfo->free_inodes = config.nr_inodes;
878 sb->s_maxbytes = MAX_LFS_FILESIZE;
879 sb->s_blocksize = huge_page_size(config.hstate);
880 sb->s_blocksize_bits = huge_page_shift(config.hstate);
881 sb->s_magic = HUGETLBFS_MAGIC;
882 sb->s_op = &hugetlbfs_ops;
883 sb->s_time_gran = 1;
884 inode = hugetlbfs_get_inode(sb, config.uid, config.gid,
885 S_IFDIR | config.mode, 0);
886 if (!inode)
887 goto out_free;
888
889 root = d_alloc_root(inode);
890 if (!root) {
891 iput(inode);
892 goto out_free;
893 }
894 sb->s_root = root;
895 return 0;
896 out_free:
897 kfree(sbinfo);
898 return -ENOMEM;
899 }
900
901 int hugetlb_get_quota(struct address_space *mapping, long delta)
902 {
903 int ret = 0;
904 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb);
905
906 if (sbinfo->free_blocks > -1) {
907 spin_lock(&sbinfo->stat_lock);
908 if (sbinfo->free_blocks - delta >= 0)
909 sbinfo->free_blocks -= delta;
910 else
911 ret = -ENOMEM;
912 spin_unlock(&sbinfo->stat_lock);
913 }
914
915 return ret;
916 }
917
918 void hugetlb_put_quota(struct address_space *mapping, long delta)
919 {
920 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb);
921
922 if (sbinfo->free_blocks > -1) {
923 spin_lock(&sbinfo->stat_lock);
924 sbinfo->free_blocks += delta;
925 spin_unlock(&sbinfo->stat_lock);
926 }
927 }
928
929 static int hugetlbfs_get_sb(struct file_system_type *fs_type,
930 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
931 {
932 return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super, mnt);
933 }
934
935 static struct file_system_type hugetlbfs_fs_type = {
936 .name = "hugetlbfs",
937 .get_sb = hugetlbfs_get_sb,
938 .kill_sb = kill_litter_super,
939 };
940
941 static struct vfsmount *hugetlbfs_vfsmount;
942
943 static int can_do_hugetlb_shm(void)
944 {
945 return capable(CAP_IPC_LOCK) || in_group_p(sysctl_hugetlb_shm_group);
946 }
947
948 struct file *hugetlb_file_setup(const char *name, size_t size, int acctflag)
949 {
950 int error = -ENOMEM;
951 int unlock_shm = 0;
952 struct file *file;
953 struct inode *inode;
954 struct dentry *dentry, *root;
955 struct qstr quick_string;
956 struct user_struct *user = current_user();
957
958 if (!hugetlbfs_vfsmount)
959 return ERR_PTR(-ENOENT);
960
961 if (!can_do_hugetlb_shm()) {
962 if (user_shm_lock(size, user)) {
963 unlock_shm = 1;
964 WARN_ONCE(1,
965 "Using mlock ulimits for SHM_HUGETLB deprecated\n");
966 } else
967 return ERR_PTR(-EPERM);
968 }
969
970 root = hugetlbfs_vfsmount->mnt_root;
971 quick_string.name = name;
972 quick_string.len = strlen(quick_string.name);
973 quick_string.hash = 0;
974 dentry = d_alloc(root, &quick_string);
975 if (!dentry)
976 goto out_shm_unlock;
977
978 error = -ENOSPC;
979 inode = hugetlbfs_get_inode(root->d_sb, current_fsuid(),
980 current_fsgid(), S_IFREG | S_IRWXUGO, 0);
981 if (!inode)
982 goto out_dentry;
983
984 error = -ENOMEM;
985 if (hugetlb_reserve_pages(inode, 0,
986 size >> huge_page_shift(hstate_inode(inode)), NULL,
987 acctflag))
988 goto out_inode;
989
990 d_instantiate(dentry, inode);
991 inode->i_size = size;
992 inode->i_nlink = 0;
993
994 error = -ENFILE;
995 file = alloc_file(hugetlbfs_vfsmount, dentry,
996 FMODE_WRITE | FMODE_READ,
997 &hugetlbfs_file_operations);
998 if (!file)
999 goto out_dentry; /* inode is already attached */
1000
1001 return file;
1002
1003 out_inode:
1004 iput(inode);
1005 out_dentry:
1006 dput(dentry);
1007 out_shm_unlock:
1008 if (unlock_shm)
1009 user_shm_unlock(size, user);
1010 return ERR_PTR(error);
1011 }
1012
1013 static int __init init_hugetlbfs_fs(void)
1014 {
1015 int error;
1016 struct vfsmount *vfsmount;
1017
1018 error = bdi_init(&hugetlbfs_backing_dev_info);
1019 if (error)
1020 return error;
1021
1022 hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
1023 sizeof(struct hugetlbfs_inode_info),
1024 0, 0, init_once);
1025 if (hugetlbfs_inode_cachep == NULL)
1026 goto out2;
1027
1028 error = register_filesystem(&hugetlbfs_fs_type);
1029 if (error)
1030 goto out;
1031
1032 vfsmount = kern_mount(&hugetlbfs_fs_type);
1033
1034 if (!IS_ERR(vfsmount)) {
1035 hugetlbfs_vfsmount = vfsmount;
1036 return 0;
1037 }
1038
1039 error = PTR_ERR(vfsmount);
1040
1041 out:
1042 if (error)
1043 kmem_cache_destroy(hugetlbfs_inode_cachep);
1044 out2:
1045 bdi_destroy(&hugetlbfs_backing_dev_info);
1046 return error;
1047 }
1048
1049 static void __exit exit_hugetlbfs_fs(void)
1050 {
1051 kmem_cache_destroy(hugetlbfs_inode_cachep);
1052 unregister_filesystem(&hugetlbfs_fs_type);
1053 bdi_destroy(&hugetlbfs_backing_dev_info);
1054 }
1055
1056 module_init(init_hugetlbfs_fs)
1057 module_exit(exit_hugetlbfs_fs)
1058
1059 MODULE_LICENSE("GPL");
Linux for Ginger Game Console