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md: use interruptible wait when duration is controlled by userspace.
[linux/fpc-iii.git] / fs / hugetlbfs / inode.c
blob941c8425c10b34493e9ad6fefef7fe54f451c84a
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
35 #include <asm/uaccess.h>
36
37 /* some random number */
38 #define HUGETLBFS_MAGIC 0x958458f6
39
40 static const struct super_operations hugetlbfs_ops;
41 static const struct address_space_operations hugetlbfs_aops;
42 const struct file_operations hugetlbfs_file_operations;
43 static const struct inode_operations hugetlbfs_dir_inode_operations;
44 static const struct inode_operations hugetlbfs_inode_operations;
45
46 static struct backing_dev_info hugetlbfs_backing_dev_info = {
47 .ra_pages = 0, /* No readahead */
48 .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
49 };
50
51 int sysctl_hugetlb_shm_group;
52
53 enum {
54 Opt_size, Opt_nr_inodes,
55 Opt_mode, Opt_uid, Opt_gid,
56 Opt_pagesize,
57 Opt_err,
58 };
59
60 static const match_table_t tokens = {
61 {Opt_size, "size=%s"},
62 {Opt_nr_inodes, "nr_inodes=%s"},
63 {Opt_mode, "mode=%o"},
64 {Opt_uid, "uid=%u"},
65 {Opt_gid, "gid=%u"},
66 {Opt_pagesize, "pagesize=%s"},
67 {Opt_err, NULL},
68 };
69
70 static void huge_pagevec_release(struct pagevec *pvec)
71 {
72 int i;
73
74 for (i = 0; i < pagevec_count(pvec); ++i)
75 put_page(pvec->pages[i]);
76
77 pagevec_reinit(pvec);
78 }
79
80 static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
81 {
82 struct inode *inode = file->f_path.dentry->d_inode;
83 loff_t len, vma_len;
84 int ret;
85 struct hstate *h = hstate_file(file);
86
87 /*
88 * vma address alignment (but not the pgoff alignment) has
89 * already been checked by prepare_hugepage_range. If you add
90 * any error returns here, do so after setting VM_HUGETLB, so
91 * is_vm_hugetlb_page tests below unmap_region go the right
92 * way when do_mmap_pgoff unwinds (may be important on powerpc
93 * and ia64).
94 */
95 vma->vm_flags |= VM_HUGETLB | VM_RESERVED;
96 vma->vm_ops = &hugetlb_vm_ops;
97
98 if (vma->vm_pgoff & ~(huge_page_mask(h) >> PAGE_SHIFT))
99 return -EINVAL;
100
101 vma_len = (loff_t)(vma->vm_end - vma->vm_start);
102
103 mutex_lock(&inode->i_mutex);
104 file_accessed(file);
105
106 ret = -ENOMEM;
107 len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
108
109 if (hugetlb_reserve_pages(inode,
110 vma->vm_pgoff >> huge_page_order(h),
111 len >> huge_page_shift(h), vma,
112 vma->vm_flags))
113 goto out;
114
115 ret = 0;
116 hugetlb_prefault_arch_hook(vma->vm_mm);
117 if (vma->vm_flags & VM_WRITE && inode->i_size < len)
118 inode->i_size = len;
119 out:
120 mutex_unlock(&inode->i_mutex);
121
122 return ret;
123 }
124
125 /*
126 * Called under down_write(mmap_sem).
127 */
128
129 #ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
130 static unsigned long
131 hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
132 unsigned long len, unsigned long pgoff, unsigned long flags)
133 {
134 struct mm_struct *mm = current->mm;
135 struct vm_area_struct *vma;
136 unsigned long start_addr;
137 struct hstate *h = hstate_file(file);
138
139 if (len & ~huge_page_mask(h))
140 return -EINVAL;
141 if (len > TASK_SIZE)
142 return -ENOMEM;
143
144 if (flags & MAP_FIXED) {
145 if (prepare_hugepage_range(file, addr, len))
146 return -EINVAL;
147 return addr;
148 }
149
150 if (addr) {
151 addr = ALIGN(addr, huge_page_size(h));
152 vma = find_vma(mm, addr);
153 if (TASK_SIZE - len >= addr &&
154 (!vma || addr + len <= vma->vm_start))
155 return addr;
156 }
157
158 start_addr = mm->free_area_cache;
159
160 if (len <= mm->cached_hole_size)
161 start_addr = TASK_UNMAPPED_BASE;
162
163 full_search:
164 addr = ALIGN(start_addr, huge_page_size(h));
165
166 for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
167 /* At this point: (!vma || addr < vma->vm_end). */
168 if (TASK_SIZE - len < addr) {
169 /*
170 * Start a new search - just in case we missed
171 * some holes.
172 */
173 if (start_addr != TASK_UNMAPPED_BASE) {
174 start_addr = TASK_UNMAPPED_BASE;
175 goto full_search;
176 }
177 return -ENOMEM;
178 }
179
180 if (!vma || addr + len <= vma->vm_start)
181 return addr;
182 addr = ALIGN(vma->vm_end, huge_page_size(h));
183 }
184 }
185 #endif
186
187 static int
188 hugetlbfs_read_actor(struct page *page, unsigned long offset,
189 char __user *buf, unsigned long count,
190 unsigned long size)
191 {
192 char *kaddr;
193 unsigned long left, copied = 0;
194 int i, chunksize;
195
196 if (size > count)
197 size = count;
198
199 /* Find which 4k chunk and offset with in that chunk */
200 i = offset >> PAGE_CACHE_SHIFT;
201 offset = offset & ~PAGE_CACHE_MASK;
202
203 while (size) {
204 chunksize = PAGE_CACHE_SIZE;
205 if (offset)
206 chunksize -= offset;
207 if (chunksize > size)
208 chunksize = size;
209 kaddr = kmap(&page[i]);
210 left = __copy_to_user(buf, kaddr + offset, chunksize);
211 kunmap(&page[i]);
212 if (left) {
213 copied += (chunksize - left);
214 break;
215 }
216 offset = 0;
217 size -= chunksize;
218 buf += chunksize;
219 copied += chunksize;
220 i++;
221 }
222 return copied ? copied : -EFAULT;
223 }
224
225 /*
226 * Support for read() - Find the page attached to f_mapping and copy out the
227 * data. Its *very* similar to do_generic_mapping_read(), we can't use that
228 * since it has PAGE_CACHE_SIZE assumptions.
229 */
230 static ssize_t hugetlbfs_read(struct file *filp, char __user *buf,
231 size_t len, loff_t *ppos)
232 {
233 struct hstate *h = hstate_file(filp);
234 struct address_space *mapping = filp->f_mapping;
235 struct inode *inode = mapping->host;
236 unsigned long index = *ppos >> huge_page_shift(h);
237 unsigned long offset = *ppos & ~huge_page_mask(h);
238 unsigned long end_index;
239 loff_t isize;
240 ssize_t retval = 0;
241
242 mutex_lock(&inode->i_mutex);
243
244 /* validate length */
245 if (len == 0)
246 goto out;
247
248 isize = i_size_read(inode);
249 if (!isize)
250 goto out;
251
252 end_index = (isize - 1) >> huge_page_shift(h);
253 for (;;) {
254 struct page *page;
255 unsigned long nr, ret;
256 int ra;
257
258 /* nr is the maximum number of bytes to copy from this page */
259 nr = huge_page_size(h);
260 if (index >= end_index) {
261 if (index > end_index)
262 goto out;
263 nr = ((isize - 1) & ~huge_page_mask(h)) + 1;
264 if (nr <= offset) {
265 goto out;
266 }
267 }
268 nr = nr - offset;
269
270 /* Find the page */
271 page = find_get_page(mapping, index);
272 if (unlikely(page == NULL)) {
273 /*
274 * We have a HOLE, zero out the user-buffer for the
275 * length of the hole or request.
276 */
277 ret = len < nr ? len : nr;
278 if (clear_user(buf, ret))
279 ra = -EFAULT;
280 else
281 ra = 0;
282 } else {
283 /*
284 * We have the page, copy it to user space buffer.
285 */
286 ra = hugetlbfs_read_actor(page, offset, buf, len, nr);
287 ret = ra;
288 }
289 if (ra < 0) {
290 if (retval == 0)
291 retval = ra;
292 if (page)
293 page_cache_release(page);
294 goto out;
295 }
296
297 offset += ret;
298 retval += ret;
299 len -= ret;
300 index += offset >> huge_page_shift(h);
301 offset &= ~huge_page_mask(h);
302
303 if (page)
304 page_cache_release(page);
305
306 /* short read or no more work */
307 if ((ret != nr) || (len == 0))
308 break;
309 }
310 out:
311 *ppos = ((loff_t)index << huge_page_shift(h)) + offset;
312 mutex_unlock(&inode->i_mutex);
313 return retval;
314 }
315
316 static int hugetlbfs_write_begin(struct file *file,
317 struct address_space *mapping,
318 loff_t pos, unsigned len, unsigned flags,
319 struct page **pagep, void **fsdata)
320 {
321 return -EINVAL;
322 }
323
324 static int hugetlbfs_write_end(struct file *file, struct address_space *mapping,
325 loff_t pos, unsigned len, unsigned copied,
326 struct page *page, void *fsdata)
327 {
328 BUG();
329 return -EINVAL;
330 }
331
332 static void truncate_huge_page(struct page *page)
333 {
334 cancel_dirty_page(page, /* No IO accounting for huge pages? */0);
335 ClearPageUptodate(page);
336 remove_from_page_cache(page);
337 put_page(page);
338 }
339
340 static void truncate_hugepages(struct inode *inode, loff_t lstart)
341 {
342 struct hstate *h = hstate_inode(inode);
343 struct address_space *mapping = &inode->i_data;
344 const pgoff_t start = lstart >> huge_page_shift(h);
345 struct pagevec pvec;
346 pgoff_t next;
347 int i, freed = 0;
348
349 pagevec_init(&pvec, 0);
350 next = start;
351 while (1) {
352 if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
353 if (next == start)
354 break;
355 next = start;
356 continue;
357 }
358
359 for (i = 0; i < pagevec_count(&pvec); ++i) {
360 struct page *page = pvec.pages[i];
361
362 lock_page(page);
363 if (page->index > next)
364 next = page->index;
365 ++next;
366 truncate_huge_page(page);
367 unlock_page(page);
368 freed++;
369 }
370 huge_pagevec_release(&pvec);
371 }
372 BUG_ON(!lstart && mapping->nrpages);
373 hugetlb_unreserve_pages(inode, start, freed);
374 }
375
376 static void hugetlbfs_delete_inode(struct inode *inode)
377 {
378 truncate_hugepages(inode, 0);
379 clear_inode(inode);
380 }
381
382 static void hugetlbfs_forget_inode(struct inode *inode) __releases(inode_lock)
383 {
384 struct super_block *sb = inode->i_sb;
385
386 if (!hlist_unhashed(&inode->i_hash)) {
387 if (!(inode->i_state & (I_DIRTY|I_SYNC)))
388 list_move(&inode->i_list, &inode_unused);
389 inodes_stat.nr_unused++;
390 if (!sb || (sb->s_flags & MS_ACTIVE)) {
391 spin_unlock(&inode_lock);
392 return;
393 }
394 inode->i_state |= I_WILL_FREE;
395 spin_unlock(&inode_lock);
396 /*
397 * write_inode_now is a noop as we set BDI_CAP_NO_WRITEBACK
398 * in our backing_dev_info.
399 */
400 write_inode_now(inode, 1);
401 spin_lock(&inode_lock);
402 inode->i_state &= ~I_WILL_FREE;
403 inodes_stat.nr_unused--;
404 hlist_del_init(&inode->i_hash);
405 }
406 list_del_init(&inode->i_list);
407 list_del_init(&inode->i_sb_list);
408 inode->i_state |= I_FREEING;
409 inodes_stat.nr_inodes--;
410 spin_unlock(&inode_lock);
411 truncate_hugepages(inode, 0);
412 clear_inode(inode);
413 destroy_inode(inode);
414 }
415
416 static void hugetlbfs_drop_inode(struct inode *inode)
417 {
418 if (!inode->i_nlink)
419 generic_delete_inode(inode);
420 else
421 hugetlbfs_forget_inode(inode);
422 }
423
424 static inline void
425 hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff)
426 {
427 struct vm_area_struct *vma;
428 struct prio_tree_iter iter;
429
430 vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) {
431 unsigned long v_offset;
432
433 /*
434 * Can the expression below overflow on 32-bit arches?
435 * No, because the prio_tree returns us only those vmas
436 * which overlap the truncated area starting at pgoff,
437 * and no vma on a 32-bit arch can span beyond the 4GB.
438 */
439 if (vma->vm_pgoff < pgoff)
440 v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT;
441 else
442 v_offset = 0;
443
444 __unmap_hugepage_range(vma,
445 vma->vm_start + v_offset, vma->vm_end, NULL);
446 }
447 }
448
449 static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
450 {
451 pgoff_t pgoff;
452 struct address_space *mapping = inode->i_mapping;
453 struct hstate *h = hstate_inode(inode);
454
455 BUG_ON(offset & ~huge_page_mask(h));
456 pgoff = offset >> PAGE_SHIFT;
457
458 i_size_write(inode, offset);
459 spin_lock(&mapping->i_mmap_lock);
460 if (!prio_tree_empty(&mapping->i_mmap))
461 hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
462 spin_unlock(&mapping->i_mmap_lock);
463 truncate_hugepages(inode, offset);
464 return 0;
465 }
466
467 static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
468 {
469 struct inode *inode = dentry->d_inode;
470 struct hstate *h = hstate_inode(inode);
471 int error;
472 unsigned int ia_valid = attr->ia_valid;
473
474 BUG_ON(!inode);
475
476 error = inode_change_ok(inode, attr);
477 if (error)
478 goto out;
479
480 if (ia_valid & ATTR_SIZE) {
481 error = -EINVAL;
482 if (!(attr->ia_size & ~huge_page_mask(h)))
483 error = hugetlb_vmtruncate(inode, attr->ia_size);
484 if (error)
485 goto out;
486 attr->ia_valid &= ~ATTR_SIZE;
487 }
488 error = inode_setattr(inode, attr);
489 out:
490 return error;
491 }
492
493 static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid,
494 gid_t gid, int mode, dev_t dev)
495 {
496 struct inode *inode;
497
498 inode = new_inode(sb);
499 if (inode) {
500 struct hugetlbfs_inode_info *info;
501 inode->i_mode = mode;
502 inode->i_uid = uid;
503 inode->i_gid = gid;
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 mpol_shared_policy_init(&info->policy, NULL);
510 switch (mode & S_IFMT) {
511 default:
512 init_special_inode(inode, mode, dev);
513 break;
514 case S_IFREG:
515 inode->i_op = &hugetlbfs_inode_operations;
516 inode->i_fop = &hugetlbfs_file_operations;
517 break;
518 case S_IFDIR:
519 inode->i_op = &hugetlbfs_dir_inode_operations;
520 inode->i_fop = &simple_dir_operations;
521
522 /* directory inodes start off with i_nlink == 2 (for "." entry) */
523 inc_nlink(inode);
524 break;
525 case S_IFLNK:
526 inode->i_op = &page_symlink_inode_operations;
527 break;
528 }
529 }
530 return inode;
531 }
532
533 /*
534 * File creation. Allocate an inode, and we're done..
535 */
536 static int hugetlbfs_mknod(struct inode *dir,
537 struct dentry *dentry, int mode, dev_t dev)
538 {
539 struct inode *inode;
540 int error = -ENOSPC;
541 gid_t gid;
542
543 if (dir->i_mode & S_ISGID) {
544 gid = dir->i_gid;
545 if (S_ISDIR(mode))
546 mode |= S_ISGID;
547 } else {
548 gid = current_fsgid();
549 }
550 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), gid, 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
560 static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int 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
568 static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd)
569 {
570 return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0);
571 }
572
573 static int hugetlbfs_symlink(struct inode *dir,
574 struct dentry *dentry, const char *symname)
575 {
576 struct inode *inode;
577 int error = -ENOSPC;
578 gid_t gid;
579
580 if (dir->i_mode & S_ISGID)
581 gid = dir->i_gid;
582 else
583 gid = current_fsgid();
584
585 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(),
586 gid, S_IFLNK|S_IRWXUGO, 0);
587 if (inode) {
588 int l = strlen(symname)+1;
589 error = page_symlink(inode, symname, l);
590 if (!error) {
591 d_instantiate(dentry, inode);
592 dget(dentry);
593 } else
594 iput(inode);
595 }
596 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
597
598 return error;
599 }
600
601 /*
602 * mark the head page dirty
603 */
604 static int hugetlbfs_set_page_dirty(struct page *page)
605 {
606 struct page *head = compound_head(page);
607
608 SetPageDirty(head);
609 return 0;
610 }
611
612 static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
613 {
614 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
615 struct hstate *h = hstate_inode(dentry->d_inode);
616
617 buf->f_type = HUGETLBFS_MAGIC;
618 buf->f_bsize = huge_page_size(h);
619 if (sbinfo) {
620 spin_lock(&sbinfo->stat_lock);
621 /* If no limits set, just report 0 for max/free/used
622 * blocks, like simple_statfs() */
623 if (sbinfo->max_blocks >= 0) {
624 buf->f_blocks = sbinfo->max_blocks;
625 buf->f_bavail = buf->f_bfree = sbinfo->free_blocks;
626 buf->f_files = sbinfo->max_inodes;
627 buf->f_ffree = sbinfo->free_inodes;
628 }
629 spin_unlock(&sbinfo->stat_lock);
630 }
631 buf->f_namelen = NAME_MAX;
632 return 0;
633 }
634
635 static void hugetlbfs_put_super(struct super_block *sb)
636 {
637 struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb);
638
639 if (sbi) {
640 sb->s_fs_info = NULL;
641 kfree(sbi);
642 }
643 }
644
645 static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo)
646 {
647 if (sbinfo->free_inodes >= 0) {
648 spin_lock(&sbinfo->stat_lock);
649 if (unlikely(!sbinfo->free_inodes)) {
650 spin_unlock(&sbinfo->stat_lock);
651 return 0;
652 }
653 sbinfo->free_inodes--;
654 spin_unlock(&sbinfo->stat_lock);
655 }
656
657 return 1;
658 }
659
660 static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
661 {
662 if (sbinfo->free_inodes >= 0) {
663 spin_lock(&sbinfo->stat_lock);
664 sbinfo->free_inodes++;
665 spin_unlock(&sbinfo->stat_lock);
666 }
667 }
668
669
670 static struct kmem_cache *hugetlbfs_inode_cachep;
671
672 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
673 {
674 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
675 struct hugetlbfs_inode_info *p;
676
677 if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
678 return NULL;
679 p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL);
680 if (unlikely(!p)) {
681 hugetlbfs_inc_free_inodes(sbinfo);
682 return NULL;
683 }
684 return &p->vfs_inode;
685 }
686
687 static void hugetlbfs_destroy_inode(struct inode *inode)
688 {
689 hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
690 mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
691 kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
692 }
693
694 static const struct address_space_operations hugetlbfs_aops = {
695 .write_begin = hugetlbfs_write_begin,
696 .write_end = hugetlbfs_write_end,
697 .set_page_dirty = hugetlbfs_set_page_dirty,
698 };
699
700
701 static void init_once(void *foo)
702 {
703 struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
704
705 inode_init_once(&ei->vfs_inode);
706 }
707
708 const struct file_operations hugetlbfs_file_operations = {
709 .read = hugetlbfs_read,
710 .mmap = hugetlbfs_file_mmap,
711 .fsync = simple_sync_file,
712 .get_unmapped_area = hugetlb_get_unmapped_area,
713 };
714
715 static const struct inode_operations hugetlbfs_dir_inode_operations = {
716 .create = hugetlbfs_create,
717 .lookup = simple_lookup,
718 .link = simple_link,
719 .unlink = simple_unlink,
720 .symlink = hugetlbfs_symlink,
721 .mkdir = hugetlbfs_mkdir,
722 .rmdir = simple_rmdir,
723 .mknod = hugetlbfs_mknod,
724 .rename = simple_rename,
725 .setattr = hugetlbfs_setattr,
726 };
727
728 static const struct inode_operations hugetlbfs_inode_operations = {
729 .setattr = hugetlbfs_setattr,
730 };
731
732 static const struct super_operations hugetlbfs_ops = {
733 .alloc_inode = hugetlbfs_alloc_inode,
734 .destroy_inode = hugetlbfs_destroy_inode,
735 .statfs = hugetlbfs_statfs,
736 .delete_inode = hugetlbfs_delete_inode,
737 .drop_inode = hugetlbfs_drop_inode,
738 .put_super = hugetlbfs_put_super,
739 .show_options = generic_show_options,
740 };
741
742 static int
743 hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
744 {
745 char *p, *rest;
746 substring_t args[MAX_OPT_ARGS];
747 int option;
748 unsigned long long size = 0;
749 enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = NO_SIZE;
750
751 if (!options)
752 return 0;
753
754 while ((p = strsep(&options, ",")) != NULL) {
755 int token;
756 if (!*p)
757 continue;
758
759 token = match_token(p, tokens, args);
760 switch (token) {
761 case Opt_uid:
762 if (match_int(&args[0], &option))
763 goto bad_val;
764 pconfig->uid = option;
765 break;
766
767 case Opt_gid:
768 if (match_int(&args[0], &option))
769 goto bad_val;
770 pconfig->gid = option;
771 break;
772
773 case Opt_mode:
774 if (match_octal(&args[0], &option))
775 goto bad_val;
776 pconfig->mode = option & 01777U;
777 break;
778
779 case Opt_size: {
780 /* memparse() will accept a K/M/G without a digit */
781 if (!isdigit(*args[0].from))
782 goto bad_val;
783 size = memparse(args[0].from, &rest);
784 setsize = SIZE_STD;
785 if (*rest == '%')
786 setsize = SIZE_PERCENT;
787 break;
788 }
789
790 case Opt_nr_inodes:
791 /* memparse() will accept a K/M/G without a digit */
792 if (!isdigit(*args[0].from))
793 goto bad_val;
794 pconfig->nr_inodes = memparse(args[0].from, &rest);
795 break;
796
797 case Opt_pagesize: {
798 unsigned long ps;
799 ps = memparse(args[0].from, &rest);
800 pconfig->hstate = size_to_hstate(ps);
801 if (!pconfig->hstate) {
802 printk(KERN_ERR
803 "hugetlbfs: Unsupported page size %lu MB\n",
804 ps >> 20);
805 return -EINVAL;
806 }
807 break;
808 }
809
810 default:
811 printk(KERN_ERR "hugetlbfs: Bad mount option: \"%s\"\n",
812 p);
813 return -EINVAL;
814 break;
815 }
816 }
817
818 /* Do size after hstate is set up */
819 if (setsize > NO_SIZE) {
820 struct hstate *h = pconfig->hstate;
821 if (setsize == SIZE_PERCENT) {
822 size <<= huge_page_shift(h);
823 size *= h->max_huge_pages;
824 do_div(size, 100);
825 }
826 pconfig->nr_blocks = (size >> huge_page_shift(h));
827 }
828
829 return 0;
830
831 bad_val:
832 printk(KERN_ERR "hugetlbfs: Bad value '%s' for mount option '%s'\n",
833 args[0].from, p);
834 return -EINVAL;
835 }
836
837 static int
838 hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
839 {
840 struct inode * inode;
841 struct dentry * root;
842 int ret;
843 struct hugetlbfs_config config;
844 struct hugetlbfs_sb_info *sbinfo;
845
846 save_mount_options(sb, data);
847
848 config.nr_blocks = -1; /* No limit on size by default */
849 config.nr_inodes = -1; /* No limit on number of inodes by default */
850 config.uid = current_fsuid();
851 config.gid = current_fsgid();
852 config.mode = 0755;
853 config.hstate = &default_hstate;
854 ret = hugetlbfs_parse_options(data, &config);
855 if (ret)
856 return ret;
857
858 sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL);
859 if (!sbinfo)
860 return -ENOMEM;
861 sb->s_fs_info = sbinfo;
862 sbinfo->hstate = config.hstate;
863 spin_lock_init(&sbinfo->stat_lock);
864 sbinfo->max_blocks = config.nr_blocks;
865 sbinfo->free_blocks = config.nr_blocks;
866 sbinfo->max_inodes = config.nr_inodes;
867 sbinfo->free_inodes = config.nr_inodes;
868 sb->s_maxbytes = MAX_LFS_FILESIZE;
869 sb->s_blocksize = huge_page_size(config.hstate);
870 sb->s_blocksize_bits = huge_page_shift(config.hstate);
871 sb->s_magic = HUGETLBFS_MAGIC;
872 sb->s_op = &hugetlbfs_ops;
873 sb->s_time_gran = 1;
874 inode = hugetlbfs_get_inode(sb, config.uid, config.gid,
875 S_IFDIR | config.mode, 0);
876 if (!inode)
877 goto out_free;
878
879 root = d_alloc_root(inode);
880 if (!root) {
881 iput(inode);
882 goto out_free;
883 }
884 sb->s_root = root;
885 return 0;
886 out_free:
887 kfree(sbinfo);
888 return -ENOMEM;
889 }
890
891 int hugetlb_get_quota(struct address_space *mapping, long delta)
892 {
893 int ret = 0;
894 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb);
895
896 if (sbinfo->free_blocks > -1) {
897 spin_lock(&sbinfo->stat_lock);
898 if (sbinfo->free_blocks - delta >= 0)
899 sbinfo->free_blocks -= delta;
900 else
901 ret = -ENOMEM;
902 spin_unlock(&sbinfo->stat_lock);
903 }
904
905 return ret;
906 }
907
908 void hugetlb_put_quota(struct address_space *mapping, long delta)
909 {
910 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb);
911
912 if (sbinfo->free_blocks > -1) {
913 spin_lock(&sbinfo->stat_lock);
914 sbinfo->free_blocks += delta;
915 spin_unlock(&sbinfo->stat_lock);
916 }
917 }
918
919 static int hugetlbfs_get_sb(struct file_system_type *fs_type,
920 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
921 {
922 return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super, mnt);
923 }
924
925 static struct file_system_type hugetlbfs_fs_type = {
926 .name = "hugetlbfs",
927 .get_sb = hugetlbfs_get_sb,
928 .kill_sb = kill_litter_super,
929 };
930
931 static struct vfsmount *hugetlbfs_vfsmount;
932
933 static int can_do_hugetlb_shm(void)
934 {
935 return capable(CAP_IPC_LOCK) || in_group_p(sysctl_hugetlb_shm_group);
936 }
937
938 struct file *hugetlb_file_setup(const char *name, size_t size, int acctflag)
939 {
940 int error = -ENOMEM;
941 int unlock_shm = 0;
942 struct file *file;
943 struct inode *inode;
944 struct dentry *dentry, *root;
945 struct qstr quick_string;
946 struct user_struct *user = current_user();
947
948 if (!hugetlbfs_vfsmount)
949 return ERR_PTR(-ENOENT);
950
951 if (!can_do_hugetlb_shm()) {
952 if (user_shm_lock(size, user)) {
953 unlock_shm = 1;
954 WARN_ONCE(1,
955 "Using mlock ulimits for SHM_HUGETLB deprecated\n");
956 } else
957 return ERR_PTR(-EPERM);
958 }
959
960 root = hugetlbfs_vfsmount->mnt_root;
961 quick_string.name = name;
962 quick_string.len = strlen(quick_string.name);
963 quick_string.hash = 0;
964 dentry = d_alloc(root, &quick_string);
965 if (!dentry)
966 goto out_shm_unlock;
967
968 error = -ENOSPC;
969 inode = hugetlbfs_get_inode(root->d_sb, current_fsuid(),
970 current_fsgid(), S_IFREG | S_IRWXUGO, 0);
971 if (!inode)
972 goto out_dentry;
973
974 error = -ENOMEM;
975 if (hugetlb_reserve_pages(inode, 0,
976 size >> huge_page_shift(hstate_inode(inode)), NULL,
977 acctflag))
978 goto out_inode;
979
980 d_instantiate(dentry, inode);
981 inode->i_size = size;
982 inode->i_nlink = 0;
983
984 error = -ENFILE;
985 file = alloc_file(hugetlbfs_vfsmount, dentry,
986 FMODE_WRITE | FMODE_READ,
987 &hugetlbfs_file_operations);
988 if (!file)
989 goto out_dentry; /* inode is already attached */
990 ima_counts_get(file);
991
992 return file;
993
994 out_inode:
995 iput(inode);
996 out_dentry:
997 dput(dentry);
998 out_shm_unlock:
999 if (unlock_shm)
1000 user_shm_unlock(size, user);
1001 return ERR_PTR(error);
1002 }
1003
1004 static int __init init_hugetlbfs_fs(void)
1005 {
1006 int error;
1007 struct vfsmount *vfsmount;
1008
1009 error = bdi_init(&hugetlbfs_backing_dev_info);
1010 if (error)
1011 return error;
1012
1013 hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
1014 sizeof(struct hugetlbfs_inode_info),
1015 0, 0, init_once);
1016 if (hugetlbfs_inode_cachep == NULL)
1017 goto out2;
1018
1019 error = register_filesystem(&hugetlbfs_fs_type);
1020 if (error)
1021 goto out;
1022
1023 vfsmount = kern_mount(&hugetlbfs_fs_type);
1024
1025 if (!IS_ERR(vfsmount)) {
1026 hugetlbfs_vfsmount = vfsmount;
1027 return 0;
1028 }
1029
1030 error = PTR_ERR(vfsmount);
1031
1032 out:
1033 if (error)
1034 kmem_cache_destroy(hugetlbfs_inode_cachep);
1035 out2:
1036 bdi_destroy(&hugetlbfs_backing_dev_info);
1037 return error;
1038 }
1039
1040 static void __exit exit_hugetlbfs_fs(void)
1041 {
1042 kmem_cache_destroy(hugetlbfs_inode_cachep);
1043 unregister_filesystem(&hugetlbfs_fs_type);
1044 bdi_destroy(&hugetlbfs_backing_dev_info);
1045 }
1046
1047 module_init(init_hugetlbfs_fs)
1048 module_exit(exit_hugetlbfs_fs)
1049
1050 MODULE_LICENSE("GPL");
Linux with added FPC-III support