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Linux 2.6.35-rc2
[linux/fpc-iii.git] / fs / hugetlbfs / inode.c
bloba4e9a7ec3691a4066deb8948da3aacd12606b896
1 /*
2 * hugetlbpage-backed filesystem. Based on ramfs.
3 *
4 * William Irwin, 2002
5 *
6 * Copyright (C) 2002 Linus Torvalds.
7 */
8
9 #include <linux/module.h>
10 #include <linux/thread_info.h>
11 #include <asm/current.h>
12 #include <linux/sched.h> /* remove ASAP */
13 #include <linux/fs.h>
14 #include <linux/mount.h>
15 #include <linux/file.h>
16 #include <linux/kernel.h>
17 #include <linux/writeback.h>
18 #include <linux/pagemap.h>
19 #include <linux/highmem.h>
20 #include <linux/init.h>
21 #include <linux/string.h>
22 #include <linux/capability.h>
23 #include <linux/ctype.h>
24 #include <linux/backing-dev.h>
25 #include <linux/hugetlb.h>
26 #include <linux/pagevec.h>
27 #include <linux/parser.h>
28 #include <linux/mman.h>
29 #include <linux/slab.h>
30 #include <linux/dnotify.h>
31 #include <linux/statfs.h>
32 #include <linux/security.h>
33 #include <linux/magic.h>
34
35 #include <asm/uaccess.h>
36
37 static const struct super_operations hugetlbfs_ops;
38 static const struct address_space_operations hugetlbfs_aops;
39 const struct file_operations hugetlbfs_file_operations;
40 static const struct inode_operations hugetlbfs_dir_inode_operations;
41 static const struct inode_operations hugetlbfs_inode_operations;
42
43 static struct backing_dev_info hugetlbfs_backing_dev_info = {
44 .name = "hugetlbfs",
45 .ra_pages = 0, /* No readahead */
46 .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
47 };
48
49 int sysctl_hugetlb_shm_group;
50
51 enum {
52 Opt_size, Opt_nr_inodes,
53 Opt_mode, Opt_uid, Opt_gid,
54 Opt_pagesize,
55 Opt_err,
56 };
57
58 static const match_table_t tokens = {
59 {Opt_size, "size=%s"},
60 {Opt_nr_inodes, "nr_inodes=%s"},
61 {Opt_mode, "mode=%o"},
62 {Opt_uid, "uid=%u"},
63 {Opt_gid, "gid=%u"},
64 {Opt_pagesize, "pagesize=%s"},
65 {Opt_err, NULL},
66 };
67
68 static void huge_pagevec_release(struct pagevec *pvec)
69 {
70 int i;
71
72 for (i = 0; i < pagevec_count(pvec); ++i)
73 put_page(pvec->pages[i]);
74
75 pagevec_reinit(pvec);
76 }
77
78 static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
79 {
80 struct inode *inode = file->f_path.dentry->d_inode;
81 loff_t len, vma_len;
82 int ret;
83 struct hstate *h = hstate_file(file);
84
85 /*
86 * vma address alignment (but not the pgoff alignment) has
87 * already been checked by prepare_hugepage_range. If you add
88 * any error returns here, do so after setting VM_HUGETLB, so
89 * is_vm_hugetlb_page tests below unmap_region go the right
90 * way when do_mmap_pgoff unwinds (may be important on powerpc
91 * and ia64).
92 */
93 vma->vm_flags |= VM_HUGETLB | VM_RESERVED;
94 vma->vm_ops = &hugetlb_vm_ops;
95
96 if (vma->vm_pgoff & ~(huge_page_mask(h) >> PAGE_SHIFT))
97 return -EINVAL;
98
99 vma_len = (loff_t)(vma->vm_end - vma->vm_start);
100
101 mutex_lock(&inode->i_mutex);
102 file_accessed(file);
103
104 ret = -ENOMEM;
105 len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
106
107 if (hugetlb_reserve_pages(inode,
108 vma->vm_pgoff >> huge_page_order(h),
109 len >> huge_page_shift(h), vma,
110 vma->vm_flags))
111 goto out;
112
113 ret = 0;
114 hugetlb_prefault_arch_hook(vma->vm_mm);
115 if (vma->vm_flags & VM_WRITE && inode->i_size < len)
116 inode->i_size = len;
117 out:
118 mutex_unlock(&inode->i_mutex);
119
120 return ret;
121 }
122
123 /*
124 * Called under down_write(mmap_sem).
125 */
126
127 #ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
128 static unsigned long
129 hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
130 unsigned long len, unsigned long pgoff, unsigned long flags)
131 {
132 struct mm_struct *mm = current->mm;
133 struct vm_area_struct *vma;
134 unsigned long start_addr;
135 struct hstate *h = hstate_file(file);
136
137 if (len & ~huge_page_mask(h))
138 return -EINVAL;
139 if (len > TASK_SIZE)
140 return -ENOMEM;
141
142 if (flags & MAP_FIXED) {
143 if (prepare_hugepage_range(file, addr, len))
144 return -EINVAL;
145 return addr;
146 }
147
148 if (addr) {
149 addr = ALIGN(addr, huge_page_size(h));
150 vma = find_vma(mm, addr);
151 if (TASK_SIZE - len >= addr &&
152 (!vma || addr + len <= vma->vm_start))
153 return addr;
154 }
155
156 start_addr = mm->free_area_cache;
157
158 if (len <= mm->cached_hole_size)
159 start_addr = TASK_UNMAPPED_BASE;
160
161 full_search:
162 addr = ALIGN(start_addr, huge_page_size(h));
163
164 for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
165 /* At this point: (!vma || addr < vma->vm_end). */
166 if (TASK_SIZE - len < addr) {
167 /*
168 * Start a new search - just in case we missed
169 * some holes.
170 */
171 if (start_addr != TASK_UNMAPPED_BASE) {
172 start_addr = TASK_UNMAPPED_BASE;
173 goto full_search;
174 }
175 return -ENOMEM;
176 }
177
178 if (!vma || addr + len <= vma->vm_start)
179 return addr;
180 addr = ALIGN(vma->vm_end, huge_page_size(h));
181 }
182 }
183 #endif
184
185 static int
186 hugetlbfs_read_actor(struct page *page, unsigned long offset,
187 char __user *buf, unsigned long count,
188 unsigned long size)
189 {
190 char *kaddr;
191 unsigned long left, copied = 0;
192 int i, chunksize;
193
194 if (size > count)
195 size = count;
196
197 /* Find which 4k chunk and offset with in that chunk */
198 i = offset >> PAGE_CACHE_SHIFT;
199 offset = offset & ~PAGE_CACHE_MASK;
200
201 while (size) {
202 chunksize = PAGE_CACHE_SIZE;
203 if (offset)
204 chunksize -= offset;
205 if (chunksize > size)
206 chunksize = size;
207 kaddr = kmap(&page[i]);
208 left = __copy_to_user(buf, kaddr + offset, chunksize);
209 kunmap(&page[i]);
210 if (left) {
211 copied += (chunksize - left);
212 break;
213 }
214 offset = 0;
215 size -= chunksize;
216 buf += chunksize;
217 copied += chunksize;
218 i++;
219 }
220 return copied ? copied : -EFAULT;
221 }
222
223 /*
224 * Support for read() - Find the page attached to f_mapping and copy out the
225 * data. Its *very* similar to do_generic_mapping_read(), we can't use that
226 * since it has PAGE_CACHE_SIZE assumptions.
227 */
228 static ssize_t hugetlbfs_read(struct file *filp, char __user *buf,
229 size_t len, loff_t *ppos)
230 {
231 struct hstate *h = hstate_file(filp);
232 struct address_space *mapping = filp->f_mapping;
233 struct inode *inode = mapping->host;
234 unsigned long index = *ppos >> huge_page_shift(h);
235 unsigned long offset = *ppos & ~huge_page_mask(h);
236 unsigned long end_index;
237 loff_t isize;
238 ssize_t retval = 0;
239
240 mutex_lock(&inode->i_mutex);
241
242 /* validate length */
243 if (len == 0)
244 goto out;
245
246 isize = i_size_read(inode);
247 if (!isize)
248 goto out;
249
250 end_index = (isize - 1) >> huge_page_shift(h);
251 for (;;) {
252 struct page *page;
253 unsigned long nr, ret;
254 int ra;
255
256 /* nr is the maximum number of bytes to copy from this page */
257 nr = huge_page_size(h);
258 if (index >= end_index) {
259 if (index > end_index)
260 goto out;
261 nr = ((isize - 1) & ~huge_page_mask(h)) + 1;
262 if (nr <= offset) {
263 goto out;
264 }
265 }
266 nr = nr - offset;
267
268 /* Find the page */
269 page = find_get_page(mapping, index);
270 if (unlikely(page == NULL)) {
271 /*
272 * We have a HOLE, zero out the user-buffer for the
273 * length of the hole or request.
274 */
275 ret = len < nr ? len : nr;
276 if (clear_user(buf, ret))
277 ra = -EFAULT;
278 else
279 ra = 0;
280 } else {
281 /*
282 * We have the page, copy it to user space buffer.
283 */
284 ra = hugetlbfs_read_actor(page, offset, buf, len, nr);
285 ret = ra;
286 }
287 if (ra < 0) {
288 if (retval == 0)
289 retval = ra;
290 if (page)
291 page_cache_release(page);
292 goto out;
293 }
294
295 offset += ret;
296 retval += ret;
297 len -= ret;
298 index += offset >> huge_page_shift(h);
299 offset &= ~huge_page_mask(h);
300
301 if (page)
302 page_cache_release(page);
303
304 /* short read or no more work */
305 if ((ret != nr) || (len == 0))
306 break;
307 }
308 out:
309 *ppos = ((loff_t)index << huge_page_shift(h)) + offset;
310 mutex_unlock(&inode->i_mutex);
311 return retval;
312 }
313
314 static int hugetlbfs_write_begin(struct file *file,
315 struct address_space *mapping,
316 loff_t pos, unsigned len, unsigned flags,
317 struct page **pagep, void **fsdata)
318 {
319 return -EINVAL;
320 }
321
322 static int hugetlbfs_write_end(struct file *file, struct address_space *mapping,
323 loff_t pos, unsigned len, unsigned copied,
324 struct page *page, void *fsdata)
325 {
326 BUG();
327 return -EINVAL;
328 }
329
330 static void truncate_huge_page(struct page *page)
331 {
332 cancel_dirty_page(page, /* No IO accounting for huge pages? */0);
333 ClearPageUptodate(page);
334 remove_from_page_cache(page);
335 put_page(page);
336 }
337
338 static void truncate_hugepages(struct inode *inode, loff_t lstart)
339 {
340 struct hstate *h = hstate_inode(inode);
341 struct address_space *mapping = &inode->i_data;
342 const pgoff_t start = lstart >> huge_page_shift(h);
343 struct pagevec pvec;
344 pgoff_t next;
345 int i, freed = 0;
346
347 pagevec_init(&pvec, 0);
348 next = start;
349 while (1) {
350 if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
351 if (next == start)
352 break;
353 next = start;
354 continue;
355 }
356
357 for (i = 0; i < pagevec_count(&pvec); ++i) {
358 struct page *page = pvec.pages[i];
359
360 lock_page(page);
361 if (page->index > next)
362 next = page->index;
363 ++next;
364 truncate_huge_page(page);
365 unlock_page(page);
366 freed++;
367 }
368 huge_pagevec_release(&pvec);
369 }
370 BUG_ON(!lstart && mapping->nrpages);
371 hugetlb_unreserve_pages(inode, start, freed);
372 }
373
374 static void hugetlbfs_delete_inode(struct inode *inode)
375 {
376 truncate_hugepages(inode, 0);
377 clear_inode(inode);
378 }
379
380 static void hugetlbfs_forget_inode(struct inode *inode) __releases(inode_lock)
381 {
382 if (generic_detach_inode(inode)) {
383 truncate_hugepages(inode, 0);
384 clear_inode(inode);
385 destroy_inode(inode);
386 }
387 }
388
389 static void hugetlbfs_drop_inode(struct inode *inode)
390 {
391 if (!inode->i_nlink)
392 generic_delete_inode(inode);
393 else
394 hugetlbfs_forget_inode(inode);
395 }
396
397 static inline void
398 hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff)
399 {
400 struct vm_area_struct *vma;
401 struct prio_tree_iter iter;
402
403 vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) {
404 unsigned long v_offset;
405
406 /*
407 * Can the expression below overflow on 32-bit arches?
408 * No, because the prio_tree returns us only those vmas
409 * which overlap the truncated area starting at pgoff,
410 * and no vma on a 32-bit arch can span beyond the 4GB.
411 */
412 if (vma->vm_pgoff < pgoff)
413 v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT;
414 else
415 v_offset = 0;
416
417 __unmap_hugepage_range(vma,
418 vma->vm_start + v_offset, vma->vm_end, NULL);
419 }
420 }
421
422 static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
423 {
424 pgoff_t pgoff;
425 struct address_space *mapping = inode->i_mapping;
426 struct hstate *h = hstate_inode(inode);
427
428 BUG_ON(offset & ~huge_page_mask(h));
429 pgoff = offset >> PAGE_SHIFT;
430
431 i_size_write(inode, offset);
432 spin_lock(&mapping->i_mmap_lock);
433 if (!prio_tree_empty(&mapping->i_mmap))
434 hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
435 spin_unlock(&mapping->i_mmap_lock);
436 truncate_hugepages(inode, offset);
437 return 0;
438 }
439
440 static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
441 {
442 struct inode *inode = dentry->d_inode;
443 struct hstate *h = hstate_inode(inode);
444 int error;
445 unsigned int ia_valid = attr->ia_valid;
446
447 BUG_ON(!inode);
448
449 error = inode_change_ok(inode, attr);
450 if (error)
451 goto out;
452
453 if (ia_valid & ATTR_SIZE) {
454 error = -EINVAL;
455 if (!(attr->ia_size & ~huge_page_mask(h)))
456 error = hugetlb_vmtruncate(inode, attr->ia_size);
457 if (error)
458 goto out;
459 attr->ia_valid &= ~ATTR_SIZE;
460 }
461 error = inode_setattr(inode, attr);
462 out:
463 return error;
464 }
465
466 static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid,
467 gid_t gid, int mode, dev_t dev)
468 {
469 struct inode *inode;
470
471 inode = new_inode(sb);
472 if (inode) {
473 struct hugetlbfs_inode_info *info;
474 inode->i_mode = mode;
475 inode->i_uid = uid;
476 inode->i_gid = gid;
477 inode->i_mapping->a_ops = &hugetlbfs_aops;
478 inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info;
479 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
480 INIT_LIST_HEAD(&inode->i_mapping->private_list);
481 info = HUGETLBFS_I(inode);
482 /*
483 * The policy is initialized here even if we are creating a
484 * private inode because initialization simply creates an
485 * an empty rb tree and calls spin_lock_init(), later when we
486 * call mpol_free_shared_policy() it will just return because
487 * the rb tree will still be empty.
488 */
489 mpol_shared_policy_init(&info->policy, NULL);
490 switch (mode & S_IFMT) {
491 default:
492 init_special_inode(inode, mode, dev);
493 break;
494 case S_IFREG:
495 inode->i_op = &hugetlbfs_inode_operations;
496 inode->i_fop = &hugetlbfs_file_operations;
497 break;
498 case S_IFDIR:
499 inode->i_op = &hugetlbfs_dir_inode_operations;
500 inode->i_fop = &simple_dir_operations;
501
502 /* directory inodes start off with i_nlink == 2 (for "." entry) */
503 inc_nlink(inode);
504 break;
505 case S_IFLNK:
506 inode->i_op = &page_symlink_inode_operations;
507 break;
508 }
509 }
510 return inode;
511 }
512
513 /*
514 * File creation. Allocate an inode, and we're done..
515 */
516 static int hugetlbfs_mknod(struct inode *dir,
517 struct dentry *dentry, int mode, dev_t dev)
518 {
519 struct inode *inode;
520 int error = -ENOSPC;
521 gid_t gid;
522
523 if (dir->i_mode & S_ISGID) {
524 gid = dir->i_gid;
525 if (S_ISDIR(mode))
526 mode |= S_ISGID;
527 } else {
528 gid = current_fsgid();
529 }
530 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), gid, mode, dev);
531 if (inode) {
532 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
533 d_instantiate(dentry, inode);
534 dget(dentry); /* Extra count - pin the dentry in core */
535 error = 0;
536 }
537 return error;
538 }
539
540 static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
541 {
542 int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0);
543 if (!retval)
544 inc_nlink(dir);
545 return retval;
546 }
547
548 static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd)
549 {
550 return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0);
551 }
552
553 static int hugetlbfs_symlink(struct inode *dir,
554 struct dentry *dentry, const char *symname)
555 {
556 struct inode *inode;
557 int error = -ENOSPC;
558 gid_t gid;
559
560 if (dir->i_mode & S_ISGID)
561 gid = dir->i_gid;
562 else
563 gid = current_fsgid();
564
565 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(),
566 gid, S_IFLNK|S_IRWXUGO, 0);
567 if (inode) {
568 int l = strlen(symname)+1;
569 error = page_symlink(inode, symname, l);
570 if (!error) {
571 d_instantiate(dentry, inode);
572 dget(dentry);
573 } else
574 iput(inode);
575 }
576 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
577
578 return error;
579 }
580
581 /*
582 * mark the head page dirty
583 */
584 static int hugetlbfs_set_page_dirty(struct page *page)
585 {
586 struct page *head = compound_head(page);
587
588 SetPageDirty(head);
589 return 0;
590 }
591
592 static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
593 {
594 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
595 struct hstate *h = hstate_inode(dentry->d_inode);
596
597 buf->f_type = HUGETLBFS_MAGIC;
598 buf->f_bsize = huge_page_size(h);
599 if (sbinfo) {
600 spin_lock(&sbinfo->stat_lock);
601 /* If no limits set, just report 0 for max/free/used
602 * blocks, like simple_statfs() */
603 if (sbinfo->max_blocks >= 0) {
604 buf->f_blocks = sbinfo->max_blocks;
605 buf->f_bavail = buf->f_bfree = sbinfo->free_blocks;
606 buf->f_files = sbinfo->max_inodes;
607 buf->f_ffree = sbinfo->free_inodes;
608 }
609 spin_unlock(&sbinfo->stat_lock);
610 }
611 buf->f_namelen = NAME_MAX;
612 return 0;
613 }
614
615 static void hugetlbfs_put_super(struct super_block *sb)
616 {
617 struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb);
618
619 if (sbi) {
620 sb->s_fs_info = NULL;
621 kfree(sbi);
622 }
623 }
624
625 static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo)
626 {
627 if (sbinfo->free_inodes >= 0) {
628 spin_lock(&sbinfo->stat_lock);
629 if (unlikely(!sbinfo->free_inodes)) {
630 spin_unlock(&sbinfo->stat_lock);
631 return 0;
632 }
633 sbinfo->free_inodes--;
634 spin_unlock(&sbinfo->stat_lock);
635 }
636
637 return 1;
638 }
639
640 static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
641 {
642 if (sbinfo->free_inodes >= 0) {
643 spin_lock(&sbinfo->stat_lock);
644 sbinfo->free_inodes++;
645 spin_unlock(&sbinfo->stat_lock);
646 }
647 }
648
649
650 static struct kmem_cache *hugetlbfs_inode_cachep;
651
652 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
653 {
654 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
655 struct hugetlbfs_inode_info *p;
656
657 if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
658 return NULL;
659 p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL);
660 if (unlikely(!p)) {
661 hugetlbfs_inc_free_inodes(sbinfo);
662 return NULL;
663 }
664 return &p->vfs_inode;
665 }
666
667 static void hugetlbfs_destroy_inode(struct inode *inode)
668 {
669 hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
670 mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
671 kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
672 }
673
674 static const struct address_space_operations hugetlbfs_aops = {
675 .write_begin = hugetlbfs_write_begin,
676 .write_end = hugetlbfs_write_end,
677 .set_page_dirty = hugetlbfs_set_page_dirty,
678 };
679
680
681 static void init_once(void *foo)
682 {
683 struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
684
685 inode_init_once(&ei->vfs_inode);
686 }
687
688 const struct file_operations hugetlbfs_file_operations = {
689 .read = hugetlbfs_read,
690 .mmap = hugetlbfs_file_mmap,
691 .fsync = noop_fsync,
692 .get_unmapped_area = hugetlb_get_unmapped_area,
693 };
694
695 static const struct inode_operations hugetlbfs_dir_inode_operations = {
696 .create = hugetlbfs_create,
697 .lookup = simple_lookup,
698 .link = simple_link,
699 .unlink = simple_unlink,
700 .symlink = hugetlbfs_symlink,
701 .mkdir = hugetlbfs_mkdir,
702 .rmdir = simple_rmdir,
703 .mknod = hugetlbfs_mknod,
704 .rename = simple_rename,
705 .setattr = hugetlbfs_setattr,
706 };
707
708 static const struct inode_operations hugetlbfs_inode_operations = {
709 .setattr = hugetlbfs_setattr,
710 };
711
712 static const struct super_operations hugetlbfs_ops = {
713 .alloc_inode = hugetlbfs_alloc_inode,
714 .destroy_inode = hugetlbfs_destroy_inode,
715 .statfs = hugetlbfs_statfs,
716 .delete_inode = hugetlbfs_delete_inode,
717 .drop_inode = hugetlbfs_drop_inode,
718 .put_super = hugetlbfs_put_super,
719 .show_options = generic_show_options,
720 };
721
722 static int
723 hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
724 {
725 char *p, *rest;
726 substring_t args[MAX_OPT_ARGS];
727 int option;
728 unsigned long long size = 0;
729 enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = NO_SIZE;
730
731 if (!options)
732 return 0;
733
734 while ((p = strsep(&options, ",")) != NULL) {
735 int token;
736 if (!*p)
737 continue;
738
739 token = match_token(p, tokens, args);
740 switch (token) {
741 case Opt_uid:
742 if (match_int(&args[0], &option))
743 goto bad_val;
744 pconfig->uid = option;
745 break;
746
747 case Opt_gid:
748 if (match_int(&args[0], &option))
749 goto bad_val;
750 pconfig->gid = option;
751 break;
752
753 case Opt_mode:
754 if (match_octal(&args[0], &option))
755 goto bad_val;
756 pconfig->mode = option & 01777U;
757 break;
758
759 case Opt_size: {
760 /* memparse() will accept a K/M/G without a digit */
761 if (!isdigit(*args[0].from))
762 goto bad_val;
763 size = memparse(args[0].from, &rest);
764 setsize = SIZE_STD;
765 if (*rest == '%')
766 setsize = SIZE_PERCENT;
767 break;
768 }
769
770 case Opt_nr_inodes:
771 /* memparse() will accept a K/M/G without a digit */
772 if (!isdigit(*args[0].from))
773 goto bad_val;
774 pconfig->nr_inodes = memparse(args[0].from, &rest);
775 break;
776
777 case Opt_pagesize: {
778 unsigned long ps;
779 ps = memparse(args[0].from, &rest);
780 pconfig->hstate = size_to_hstate(ps);
781 if (!pconfig->hstate) {
782 printk(KERN_ERR
783 "hugetlbfs: Unsupported page size %lu MB\n",
784 ps >> 20);
785 return -EINVAL;
786 }
787 break;
788 }
789
790 default:
791 printk(KERN_ERR "hugetlbfs: Bad mount option: \"%s\"\n",
792 p);
793 return -EINVAL;
794 break;
795 }
796 }
797
798 /* Do size after hstate is set up */
799 if (setsize > NO_SIZE) {
800 struct hstate *h = pconfig->hstate;
801 if (setsize == SIZE_PERCENT) {
802 size <<= huge_page_shift(h);
803 size *= h->max_huge_pages;
804 do_div(size, 100);
805 }
806 pconfig->nr_blocks = (size >> huge_page_shift(h));
807 }
808
809 return 0;
810
811 bad_val:
812 printk(KERN_ERR "hugetlbfs: Bad value '%s' for mount option '%s'\n",
813 args[0].from, p);
814 return -EINVAL;
815 }
816
817 static int
818 hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
819 {
820 struct inode * inode;
821 struct dentry * root;
822 int ret;
823 struct hugetlbfs_config config;
824 struct hugetlbfs_sb_info *sbinfo;
825
826 save_mount_options(sb, data);
827
828 config.nr_blocks = -1; /* No limit on size by default */
829 config.nr_inodes = -1; /* No limit on number of inodes by default */
830 config.uid = current_fsuid();
831 config.gid = current_fsgid();
832 config.mode = 0755;
833 config.hstate = &default_hstate;
834 ret = hugetlbfs_parse_options(data, &config);
835 if (ret)
836 return ret;
837
838 sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL);
839 if (!sbinfo)
840 return -ENOMEM;
841 sb->s_fs_info = sbinfo;
842 sbinfo->hstate = config.hstate;
843 spin_lock_init(&sbinfo->stat_lock);
844 sbinfo->max_blocks = config.nr_blocks;
845 sbinfo->free_blocks = config.nr_blocks;
846 sbinfo->max_inodes = config.nr_inodes;
847 sbinfo->free_inodes = config.nr_inodes;
848 sb->s_maxbytes = MAX_LFS_FILESIZE;
849 sb->s_blocksize = huge_page_size(config.hstate);
850 sb->s_blocksize_bits = huge_page_shift(config.hstate);
851 sb->s_magic = HUGETLBFS_MAGIC;
852 sb->s_op = &hugetlbfs_ops;
853 sb->s_time_gran = 1;
854 inode = hugetlbfs_get_inode(sb, config.uid, config.gid,
855 S_IFDIR | config.mode, 0);
856 if (!inode)
857 goto out_free;
858
859 root = d_alloc_root(inode);
860 if (!root) {
861 iput(inode);
862 goto out_free;
863 }
864 sb->s_root = root;
865 return 0;
866 out_free:
867 kfree(sbinfo);
868 return -ENOMEM;
869 }
870
871 int hugetlb_get_quota(struct address_space *mapping, long delta)
872 {
873 int ret = 0;
874 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb);
875
876 if (sbinfo->free_blocks > -1) {
877 spin_lock(&sbinfo->stat_lock);
878 if (sbinfo->free_blocks - delta >= 0)
879 sbinfo->free_blocks -= delta;
880 else
881 ret = -ENOMEM;
882 spin_unlock(&sbinfo->stat_lock);
883 }
884
885 return ret;
886 }
887
888 void hugetlb_put_quota(struct address_space *mapping, long delta)
889 {
890 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb);
891
892 if (sbinfo->free_blocks > -1) {
893 spin_lock(&sbinfo->stat_lock);
894 sbinfo->free_blocks += delta;
895 spin_unlock(&sbinfo->stat_lock);
896 }
897 }
898
899 static int hugetlbfs_get_sb(struct file_system_type *fs_type,
900 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
901 {
902 return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super, mnt);
903 }
904
905 static struct file_system_type hugetlbfs_fs_type = {
906 .name = "hugetlbfs",
907 .get_sb = hugetlbfs_get_sb,
908 .kill_sb = kill_litter_super,
909 };
910
911 static struct vfsmount *hugetlbfs_vfsmount;
912
913 static int can_do_hugetlb_shm(void)
914 {
915 return capable(CAP_IPC_LOCK) || in_group_p(sysctl_hugetlb_shm_group);
916 }
917
918 struct file *hugetlb_file_setup(const char *name, size_t size, int acctflag,
919 struct user_struct **user, int creat_flags)
920 {
921 int error = -ENOMEM;
922 struct file *file;
923 struct inode *inode;
924 struct path path;
925 struct 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 path.dentry = d_alloc(root, &quick_string);
948 if (!path.dentry)
949 goto out_shm_unlock;
950
951 path.mnt = mntget(hugetlbfs_vfsmount);
952 error = -ENOSPC;
953 inode = hugetlbfs_get_inode(root->d_sb, current_fsuid(),
954 current_fsgid(), S_IFREG | S_IRWXUGO, 0);
955 if (!inode)
956 goto out_dentry;
957
958 error = -ENOMEM;
959 if (hugetlb_reserve_pages(inode, 0,
960 size >> huge_page_shift(hstate_inode(inode)), NULL,
961 acctflag))
962 goto out_inode;
963
964 d_instantiate(path.dentry, inode);
965 inode->i_size = size;
966 inode->i_nlink = 0;
967
968 error = -ENFILE;
969 file = alloc_file(&path, FMODE_WRITE | FMODE_READ,
970 &hugetlbfs_file_operations);
971 if (!file)
972 goto out_dentry; /* inode is already attached */
973
974 return file;
975
976 out_inode:
977 iput(inode);
978 out_dentry:
979 path_put(&path);
980 out_shm_unlock:
981 if (*user) {
982 user_shm_unlock(size, *user);
983 *user = NULL;
984 }
985 return ERR_PTR(error);
986 }
987
988 static int __init init_hugetlbfs_fs(void)
989 {
990 int error;
991 struct vfsmount *vfsmount;
992
993 error = bdi_init(&hugetlbfs_backing_dev_info);
994 if (error)
995 return error;
996
997 hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
998 sizeof(struct hugetlbfs_inode_info),
999 0, 0, init_once);
1000 if (hugetlbfs_inode_cachep == NULL)
1001 goto out2;
1002
1003 error = register_filesystem(&hugetlbfs_fs_type);
1004 if (error)
1005 goto out;
1006
1007 vfsmount = kern_mount(&hugetlbfs_fs_type);
1008
1009 if (!IS_ERR(vfsmount)) {
1010 hugetlbfs_vfsmount = vfsmount;
1011 return 0;
1012 }
1013
1014 error = PTR_ERR(vfsmount);
1015
1016 out:
1017 if (error)
1018 kmem_cache_destroy(hugetlbfs_inode_cachep);
1019 out2:
1020 bdi_destroy(&hugetlbfs_backing_dev_info);
1021 return error;
1022 }
1023
1024 static void __exit exit_hugetlbfs_fs(void)
1025 {
1026 kmem_cache_destroy(hugetlbfs_inode_cachep);
1027 unregister_filesystem(&hugetlbfs_fs_type);
1028 bdi_destroy(&hugetlbfs_backing_dev_info);
1029 }
1030
1031 module_init(init_hugetlbfs_fs)
1032 module_exit(exit_hugetlbfs_fs)
1033
1034 MODULE_LICENSE("GPL");
Linux with added FPC-III support