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hugetlbfs: do not call user_shm_lock() for MAP_HUGETLB fix
[linux/fpc-iii.git] / fs / hugetlbfs / inode.c
blob133335479c241768e4b7490d155c48881d9de373
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 struct super_block *sb = inode->i_sb;
384
385 if (!hlist_unhashed(&inode->i_hash)) {
386 if (!(inode->i_state & (I_DIRTY|I_SYNC)))
387 list_move(&inode->i_list, &inode_unused);
388 inodes_stat.nr_unused++;
389 if (!sb || (sb->s_flags & MS_ACTIVE)) {
390 spin_unlock(&inode_lock);
391 return;
392 }
393 inode->i_state |= I_WILL_FREE;
394 spin_unlock(&inode_lock);
395 /*
396 * write_inode_now is a noop as we set BDI_CAP_NO_WRITEBACK
397 * in our backing_dev_info.
398 */
399 write_inode_now(inode, 1);
400 spin_lock(&inode_lock);
401 inode->i_state &= ~I_WILL_FREE;
402 inodes_stat.nr_unused--;
403 hlist_del_init(&inode->i_hash);
404 }
405 list_del_init(&inode->i_list);
406 list_del_init(&inode->i_sb_list);
407 inode->i_state |= I_FREEING;
408 inodes_stat.nr_inodes--;
409 spin_unlock(&inode_lock);
410 truncate_hugepages(inode, 0);
411 clear_inode(inode);
412 destroy_inode(inode);
413 }
414
415 static void hugetlbfs_drop_inode(struct inode *inode)
416 {
417 if (!inode->i_nlink)
418 generic_delete_inode(inode);
419 else
420 hugetlbfs_forget_inode(inode);
421 }
422
423 static inline void
424 hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff)
425 {
426 struct vm_area_struct *vma;
427 struct prio_tree_iter iter;
428
429 vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) {
430 unsigned long v_offset;
431
432 /*
433 * Can the expression below overflow on 32-bit arches?
434 * No, because the prio_tree returns us only those vmas
435 * which overlap the truncated area starting at pgoff,
436 * and no vma on a 32-bit arch can span beyond the 4GB.
437 */
438 if (vma->vm_pgoff < pgoff)
439 v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT;
440 else
441 v_offset = 0;
442
443 __unmap_hugepage_range(vma,
444 vma->vm_start + v_offset, vma->vm_end, NULL);
445 }
446 }
447
448 static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
449 {
450 pgoff_t pgoff;
451 struct address_space *mapping = inode->i_mapping;
452 struct hstate *h = hstate_inode(inode);
453
454 BUG_ON(offset & ~huge_page_mask(h));
455 pgoff = offset >> PAGE_SHIFT;
456
457 i_size_write(inode, offset);
458 spin_lock(&mapping->i_mmap_lock);
459 if (!prio_tree_empty(&mapping->i_mmap))
460 hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
461 spin_unlock(&mapping->i_mmap_lock);
462 truncate_hugepages(inode, offset);
463 return 0;
464 }
465
466 static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
467 {
468 struct inode *inode = dentry->d_inode;
469 struct hstate *h = hstate_inode(inode);
470 int error;
471 unsigned int ia_valid = attr->ia_valid;
472
473 BUG_ON(!inode);
474
475 error = inode_change_ok(inode, attr);
476 if (error)
477 goto out;
478
479 if (ia_valid & ATTR_SIZE) {
480 error = -EINVAL;
481 if (!(attr->ia_size & ~huge_page_mask(h)))
482 error = hugetlb_vmtruncate(inode, attr->ia_size);
483 if (error)
484 goto out;
485 attr->ia_valid &= ~ATTR_SIZE;
486 }
487 error = inode_setattr(inode, attr);
488 out:
489 return error;
490 }
491
492 static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid,
493 gid_t gid, int mode, dev_t dev)
494 {
495 struct inode *inode;
496
497 inode = new_inode(sb);
498 if (inode) {
499 struct hugetlbfs_inode_info *info;
500 inode->i_mode = mode;
501 inode->i_uid = uid;
502 inode->i_gid = gid;
503 inode->i_mapping->a_ops = &hugetlbfs_aops;
504 inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info;
505 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
506 INIT_LIST_HEAD(&inode->i_mapping->private_list);
507 info = HUGETLBFS_I(inode);
508 /*
509 * The policy is initialized here even if we are creating a
510 * private inode because initialization simply creates an
511 * an empty rb tree and calls spin_lock_init(), later when we
512 * call mpol_free_shared_policy() it will just return because
513 * the rb tree will still be empty.
514 */
515 mpol_shared_policy_init(&info->policy, NULL);
516 switch (mode & S_IFMT) {
517 default:
518 init_special_inode(inode, mode, dev);
519 break;
520 case S_IFREG:
521 inode->i_op = &hugetlbfs_inode_operations;
522 inode->i_fop = &hugetlbfs_file_operations;
523 break;
524 case S_IFDIR:
525 inode->i_op = &hugetlbfs_dir_inode_operations;
526 inode->i_fop = &simple_dir_operations;
527
528 /* directory inodes start off with i_nlink == 2 (for "." entry) */
529 inc_nlink(inode);
530 break;
531 case S_IFLNK:
532 inode->i_op = &page_symlink_inode_operations;
533 break;
534 }
535 }
536 return inode;
537 }
538
539 /*
540 * File creation. Allocate an inode, and we're done..
541 */
542 static int hugetlbfs_mknod(struct inode *dir,
543 struct dentry *dentry, int mode, dev_t dev)
544 {
545 struct inode *inode;
546 int error = -ENOSPC;
547 gid_t gid;
548
549 if (dir->i_mode & S_ISGID) {
550 gid = dir->i_gid;
551 if (S_ISDIR(mode))
552 mode |= S_ISGID;
553 } else {
554 gid = current_fsgid();
555 }
556 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), gid, mode, dev);
557 if (inode) {
558 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
559 d_instantiate(dentry, inode);
560 dget(dentry); /* Extra count - pin the dentry in core */
561 error = 0;
562 }
563 return error;
564 }
565
566 static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
567 {
568 int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0);
569 if (!retval)
570 inc_nlink(dir);
571 return retval;
572 }
573
574 static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd)
575 {
576 return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0);
577 }
578
579 static int hugetlbfs_symlink(struct inode *dir,
580 struct dentry *dentry, const char *symname)
581 {
582 struct inode *inode;
583 int error = -ENOSPC;
584 gid_t gid;
585
586 if (dir->i_mode & S_ISGID)
587 gid = dir->i_gid;
588 else
589 gid = current_fsgid();
590
591 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(),
592 gid, S_IFLNK|S_IRWXUGO, 0);
593 if (inode) {
594 int l = strlen(symname)+1;
595 error = page_symlink(inode, symname, l);
596 if (!error) {
597 d_instantiate(dentry, inode);
598 dget(dentry);
599 } else
600 iput(inode);
601 }
602 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
603
604 return error;
605 }
606
607 /*
608 * mark the head page dirty
609 */
610 static int hugetlbfs_set_page_dirty(struct page *page)
611 {
612 struct page *head = compound_head(page);
613
614 SetPageDirty(head);
615 return 0;
616 }
617
618 static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
619 {
620 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
621 struct hstate *h = hstate_inode(dentry->d_inode);
622
623 buf->f_type = HUGETLBFS_MAGIC;
624 buf->f_bsize = huge_page_size(h);
625 if (sbinfo) {
626 spin_lock(&sbinfo->stat_lock);
627 /* If no limits set, just report 0 for max/free/used
628 * blocks, like simple_statfs() */
629 if (sbinfo->max_blocks >= 0) {
630 buf->f_blocks = sbinfo->max_blocks;
631 buf->f_bavail = buf->f_bfree = sbinfo->free_blocks;
632 buf->f_files = sbinfo->max_inodes;
633 buf->f_ffree = sbinfo->free_inodes;
634 }
635 spin_unlock(&sbinfo->stat_lock);
636 }
637 buf->f_namelen = NAME_MAX;
638 return 0;
639 }
640
641 static void hugetlbfs_put_super(struct super_block *sb)
642 {
643 struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb);
644
645 if (sbi) {
646 sb->s_fs_info = NULL;
647 kfree(sbi);
648 }
649 }
650
651 static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo)
652 {
653 if (sbinfo->free_inodes >= 0) {
654 spin_lock(&sbinfo->stat_lock);
655 if (unlikely(!sbinfo->free_inodes)) {
656 spin_unlock(&sbinfo->stat_lock);
657 return 0;
658 }
659 sbinfo->free_inodes--;
660 spin_unlock(&sbinfo->stat_lock);
661 }
662
663 return 1;
664 }
665
666 static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
667 {
668 if (sbinfo->free_inodes >= 0) {
669 spin_lock(&sbinfo->stat_lock);
670 sbinfo->free_inodes++;
671 spin_unlock(&sbinfo->stat_lock);
672 }
673 }
674
675
676 static struct kmem_cache *hugetlbfs_inode_cachep;
677
678 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
679 {
680 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
681 struct hugetlbfs_inode_info *p;
682
683 if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
684 return NULL;
685 p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL);
686 if (unlikely(!p)) {
687 hugetlbfs_inc_free_inodes(sbinfo);
688 return NULL;
689 }
690 return &p->vfs_inode;
691 }
692
693 static void hugetlbfs_destroy_inode(struct inode *inode)
694 {
695 hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
696 mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
697 kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
698 }
699
700 static const struct address_space_operations hugetlbfs_aops = {
701 .write_begin = hugetlbfs_write_begin,
702 .write_end = hugetlbfs_write_end,
703 .set_page_dirty = hugetlbfs_set_page_dirty,
704 };
705
706
707 static void init_once(void *foo)
708 {
709 struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
710
711 inode_init_once(&ei->vfs_inode);
712 }
713
714 const struct file_operations hugetlbfs_file_operations = {
715 .read = hugetlbfs_read,
716 .mmap = hugetlbfs_file_mmap,
717 .fsync = simple_sync_file,
718 .get_unmapped_area = hugetlb_get_unmapped_area,
719 };
720
721 static const struct inode_operations hugetlbfs_dir_inode_operations = {
722 .create = hugetlbfs_create,
723 .lookup = simple_lookup,
724 .link = simple_link,
725 .unlink = simple_unlink,
726 .symlink = hugetlbfs_symlink,
727 .mkdir = hugetlbfs_mkdir,
728 .rmdir = simple_rmdir,
729 .mknod = hugetlbfs_mknod,
730 .rename = simple_rename,
731 .setattr = hugetlbfs_setattr,
732 };
733
734 static const struct inode_operations hugetlbfs_inode_operations = {
735 .setattr = hugetlbfs_setattr,
736 };
737
738 static const struct super_operations hugetlbfs_ops = {
739 .alloc_inode = hugetlbfs_alloc_inode,
740 .destroy_inode = hugetlbfs_destroy_inode,
741 .statfs = hugetlbfs_statfs,
742 .delete_inode = hugetlbfs_delete_inode,
743 .drop_inode = hugetlbfs_drop_inode,
744 .put_super = hugetlbfs_put_super,
745 .show_options = generic_show_options,
746 };
747
748 static int
749 hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
750 {
751 char *p, *rest;
752 substring_t args[MAX_OPT_ARGS];
753 int option;
754 unsigned long long size = 0;
755 enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = NO_SIZE;
756
757 if (!options)
758 return 0;
759
760 while ((p = strsep(&options, ",")) != NULL) {
761 int token;
762 if (!*p)
763 continue;
764
765 token = match_token(p, tokens, args);
766 switch (token) {
767 case Opt_uid:
768 if (match_int(&args[0], &option))
769 goto bad_val;
770 pconfig->uid = option;
771 break;
772
773 case Opt_gid:
774 if (match_int(&args[0], &option))
775 goto bad_val;
776 pconfig->gid = option;
777 break;
778
779 case Opt_mode:
780 if (match_octal(&args[0], &option))
781 goto bad_val;
782 pconfig->mode = option & 01777U;
783 break;
784
785 case Opt_size: {
786 /* memparse() will accept a K/M/G without a digit */
787 if (!isdigit(*args[0].from))
788 goto bad_val;
789 size = memparse(args[0].from, &rest);
790 setsize = SIZE_STD;
791 if (*rest == '%')
792 setsize = SIZE_PERCENT;
793 break;
794 }
795
796 case Opt_nr_inodes:
797 /* memparse() will accept a K/M/G without a digit */
798 if (!isdigit(*args[0].from))
799 goto bad_val;
800 pconfig->nr_inodes = memparse(args[0].from, &rest);
801 break;
802
803 case Opt_pagesize: {
804 unsigned long ps;
805 ps = memparse(args[0].from, &rest);
806 pconfig->hstate = size_to_hstate(ps);
807 if (!pconfig->hstate) {
808 printk(KERN_ERR
809 "hugetlbfs: Unsupported page size %lu MB\n",
810 ps >> 20);
811 return -EINVAL;
812 }
813 break;
814 }
815
816 default:
817 printk(KERN_ERR "hugetlbfs: Bad mount option: \"%s\"\n",
818 p);
819 return -EINVAL;
820 break;
821 }
822 }
823
824 /* Do size after hstate is set up */
825 if (setsize > NO_SIZE) {
826 struct hstate *h = pconfig->hstate;
827 if (setsize == SIZE_PERCENT) {
828 size <<= huge_page_shift(h);
829 size *= h->max_huge_pages;
830 do_div(size, 100);
831 }
832 pconfig->nr_blocks = (size >> huge_page_shift(h));
833 }
834
835 return 0;
836
837 bad_val:
838 printk(KERN_ERR "hugetlbfs: Bad value '%s' for mount option '%s'\n",
839 args[0].from, p);
840 return -EINVAL;
841 }
842
843 static int
844 hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
845 {
846 struct inode * inode;
847 struct dentry * root;
848 int ret;
849 struct hugetlbfs_config config;
850 struct hugetlbfs_sb_info *sbinfo;
851
852 save_mount_options(sb, data);
853
854 config.nr_blocks = -1; /* No limit on size by default */
855 config.nr_inodes = -1; /* No limit on number of inodes by default */
856 config.uid = current_fsuid();
857 config.gid = current_fsgid();
858 config.mode = 0755;
859 config.hstate = &default_hstate;
860 ret = hugetlbfs_parse_options(data, &config);
861 if (ret)
862 return ret;
863
864 sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL);
865 if (!sbinfo)
866 return -ENOMEM;
867 sb->s_fs_info = sbinfo;
868 sbinfo->hstate = config.hstate;
869 spin_lock_init(&sbinfo->stat_lock);
870 sbinfo->max_blocks = config.nr_blocks;
871 sbinfo->free_blocks = config.nr_blocks;
872 sbinfo->max_inodes = config.nr_inodes;
873 sbinfo->free_inodes = config.nr_inodes;
874 sb->s_maxbytes = MAX_LFS_FILESIZE;
875 sb->s_blocksize = huge_page_size(config.hstate);
876 sb->s_blocksize_bits = huge_page_shift(config.hstate);
877 sb->s_magic = HUGETLBFS_MAGIC;
878 sb->s_op = &hugetlbfs_ops;
879 sb->s_time_gran = 1;
880 inode = hugetlbfs_get_inode(sb, config.uid, config.gid,
881 S_IFDIR | config.mode, 0);
882 if (!inode)
883 goto out_free;
884
885 root = d_alloc_root(inode);
886 if (!root) {
887 iput(inode);
888 goto out_free;
889 }
890 sb->s_root = root;
891 return 0;
892 out_free:
893 kfree(sbinfo);
894 return -ENOMEM;
895 }
896
897 int hugetlb_get_quota(struct address_space *mapping, long delta)
898 {
899 int ret = 0;
900 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb);
901
902 if (sbinfo->free_blocks > -1) {
903 spin_lock(&sbinfo->stat_lock);
904 if (sbinfo->free_blocks - delta >= 0)
905 sbinfo->free_blocks -= delta;
906 else
907 ret = -ENOMEM;
908 spin_unlock(&sbinfo->stat_lock);
909 }
910
911 return ret;
912 }
913
914 void hugetlb_put_quota(struct address_space *mapping, long delta)
915 {
916 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb);
917
918 if (sbinfo->free_blocks > -1) {
919 spin_lock(&sbinfo->stat_lock);
920 sbinfo->free_blocks += delta;
921 spin_unlock(&sbinfo->stat_lock);
922 }
923 }
924
925 static int hugetlbfs_get_sb(struct file_system_type *fs_type,
926 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
927 {
928 return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super, mnt);
929 }
930
931 static struct file_system_type hugetlbfs_fs_type = {
932 .name = "hugetlbfs",
933 .get_sb = hugetlbfs_get_sb,
934 .kill_sb = kill_litter_super,
935 };
936
937 static struct vfsmount *hugetlbfs_vfsmount;
938
939 static int can_do_hugetlb_shm(void)
940 {
941 return capable(CAP_IPC_LOCK) || in_group_p(sysctl_hugetlb_shm_group);
942 }
943
944 struct file *hugetlb_file_setup(const char *name, size_t size, int acctflag,
945 struct user_struct **user, int creat_flags)
946 {
947 int error = -ENOMEM;
948 struct file *file;
949 struct inode *inode;
950 struct dentry *dentry, *root;
951 struct qstr quick_string;
952
953 *user = NULL;
954 if (!hugetlbfs_vfsmount)
955 return ERR_PTR(-ENOENT);
956
957 if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) {
958 *user = current_user();
959 if (user_shm_lock(size, *user)) {
960 WARN_ONCE(1,
961 "Using mlock ulimits for SHM_HUGETLB deprecated\n");
962 } else {
963 *user = NULL;
964 return ERR_PTR(-EPERM);
965 }
966 }
967
968 root = hugetlbfs_vfsmount->mnt_root;
969 quick_string.name = name;
970 quick_string.len = strlen(quick_string.name);
971 quick_string.hash = 0;
972 dentry = d_alloc(root, &quick_string);
973 if (!dentry)
974 goto out_shm_unlock;
975
976 error = -ENOSPC;
977 inode = hugetlbfs_get_inode(root->d_sb, current_fsuid(),
978 current_fsgid(), S_IFREG | S_IRWXUGO, 0);
979 if (!inode)
980 goto out_dentry;
981
982 error = -ENOMEM;
983 if (hugetlb_reserve_pages(inode, 0,
984 size >> huge_page_shift(hstate_inode(inode)), NULL,
985 acctflag))
986 goto out_inode;
987
988 d_instantiate(dentry, inode);
989 inode->i_size = size;
990 inode->i_nlink = 0;
991
992 error = -ENFILE;
993 file = alloc_file(hugetlbfs_vfsmount, dentry,
994 FMODE_WRITE | FMODE_READ,
995 &hugetlbfs_file_operations);
996 if (!file)
997 goto out_dentry; /* inode is already attached */
998 ima_counts_get(file);
999
1000 return file;
1001
1002 out_inode:
1003 iput(inode);
1004 out_dentry:
1005 dput(dentry);
1006 out_shm_unlock:
1007 if (*user) {
1008 user_shm_unlock(size, *user);
1009 *user = NULL;
1010 }
1011 return ERR_PTR(error);
1012 }
1013
1014 static int __init init_hugetlbfs_fs(void)
1015 {
1016 int error;
1017 struct vfsmount *vfsmount;
1018
1019 error = bdi_init(&hugetlbfs_backing_dev_info);
1020 if (error)
1021 return error;
1022
1023 hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
1024 sizeof(struct hugetlbfs_inode_info),
1025 0, 0, init_once);
1026 if (hugetlbfs_inode_cachep == NULL)
1027 goto out2;
1028
1029 error = register_filesystem(&hugetlbfs_fs_type);
1030 if (error)
1031 goto out;
1032
1033 vfsmount = kern_mount(&hugetlbfs_fs_type);
1034
1035 if (!IS_ERR(vfsmount)) {
1036 hugetlbfs_vfsmount = vfsmount;
1037 return 0;
1038 }
1039
1040 error = PTR_ERR(vfsmount);
1041
1042 out:
1043 if (error)
1044 kmem_cache_destroy(hugetlbfs_inode_cachep);
1045 out2:
1046 bdi_destroy(&hugetlbfs_backing_dev_info);
1047 return error;
1048 }
1049
1050 static void __exit exit_hugetlbfs_fs(void)
1051 {
1052 kmem_cache_destroy(hugetlbfs_inode_cachep);
1053 unregister_filesystem(&hugetlbfs_fs_type);
1054 bdi_destroy(&hugetlbfs_backing_dev_info);
1055 }
1056
1057 module_init(init_hugetlbfs_fs)
1058 module_exit(exit_hugetlbfs_fs)
1059
1060 MODULE_LICENSE("GPL");
Linux with added FPC-III support