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GUI: Fix Tomato RAF theme for all builds. Compilation typo.
[tomato.git] / release / src-rt-6.x.4708 / linux / linux-2.6.36 / fs / hugetlbfs / inode.c
blob6e5bd42f38604dd1573992bb16aad0076a03be03
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_evict_inode(struct inode *inode)
375 {
376 truncate_hugepages(inode, 0);
377 end_writeback(inode);
378 }
379
380 static inline void
381 hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff)
382 {
383 struct vm_area_struct *vma;
384 struct prio_tree_iter iter;
385
386 vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) {
387 unsigned long v_offset;
388
389 /*
390 * Can the expression below overflow on 32-bit arches?
391 * No, because the prio_tree returns us only those vmas
392 * which overlap the truncated area starting at pgoff,
393 * and no vma on a 32-bit arch can span beyond the 4GB.
394 */
395 if (vma->vm_pgoff < pgoff)
396 v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT;
397 else
398 v_offset = 0;
399
400 __unmap_hugepage_range(vma,
401 vma->vm_start + v_offset, vma->vm_end, NULL);
402 }
403 }
404
405 static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
406 {
407 pgoff_t pgoff;
408 struct address_space *mapping = inode->i_mapping;
409 struct hstate *h = hstate_inode(inode);
410
411 BUG_ON(offset & ~huge_page_mask(h));
412 pgoff = offset >> PAGE_SHIFT;
413
414 i_size_write(inode, offset);
415 spin_lock(&mapping->i_mmap_lock);
416 if (!prio_tree_empty(&mapping->i_mmap))
417 hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
418 spin_unlock(&mapping->i_mmap_lock);
419 truncate_hugepages(inode, offset);
420 return 0;
421 }
422
423 static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
424 {
425 struct inode *inode = dentry->d_inode;
426 struct hstate *h = hstate_inode(inode);
427 int error;
428 unsigned int ia_valid = attr->ia_valid;
429
430 BUG_ON(!inode);
431
432 error = inode_change_ok(inode, attr);
433 if (error)
434 return error;
435
436 if (ia_valid & ATTR_SIZE) {
437 error = -EINVAL;
438 if (attr->ia_size & ~huge_page_mask(h))
439 return -EINVAL;
440 error = hugetlb_vmtruncate(inode, attr->ia_size);
441 if (error)
442 return error;
443 }
444
445 setattr_copy(inode, attr);
446 mark_inode_dirty(inode);
447 return 0;
448 }
449
450 static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid,
451 gid_t gid, int mode, dev_t dev)
452 {
453 struct inode *inode;
454
455 inode = new_inode(sb);
456 if (inode) {
457 struct hugetlbfs_inode_info *info;
458 inode->i_mode = mode;
459 inode->i_uid = uid;
460 inode->i_gid = gid;
461 inode->i_mapping->a_ops = &hugetlbfs_aops;
462 inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info;
463 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
464 INIT_LIST_HEAD(&inode->i_mapping->private_list);
465 info = HUGETLBFS_I(inode);
466 /*
467 * The policy is initialized here even if we are creating a
468 * private inode because initialization simply creates an
469 * an empty rb tree and calls spin_lock_init(), later when we
470 * call mpol_free_shared_policy() it will just return because
471 * the rb tree will still be empty.
472 */
473 mpol_shared_policy_init(&info->policy, NULL);
474 switch (mode & S_IFMT) {
475 default:
476 init_special_inode(inode, mode, dev);
477 break;
478 case S_IFREG:
479 inode->i_op = &hugetlbfs_inode_operations;
480 inode->i_fop = &hugetlbfs_file_operations;
481 break;
482 case S_IFDIR:
483 inode->i_op = &hugetlbfs_dir_inode_operations;
484 inode->i_fop = &simple_dir_operations;
485
486 /* directory inodes start off with i_nlink == 2 (for "." entry) */
487 inc_nlink(inode);
488 break;
489 case S_IFLNK:
490 inode->i_op = &page_symlink_inode_operations;
491 break;
492 }
493 }
494 return inode;
495 }
496
497 /*
498 * File creation. Allocate an inode, and we're done..
499 */
500 static int hugetlbfs_mknod(struct inode *dir,
501 struct dentry *dentry, int mode, dev_t dev)
502 {
503 struct inode *inode;
504 int error = -ENOSPC;
505 gid_t gid;
506
507 if (dir->i_mode & S_ISGID) {
508 gid = dir->i_gid;
509 if (S_ISDIR(mode))
510 mode |= S_ISGID;
511 } else {
512 gid = current_fsgid();
513 }
514 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), gid, mode, dev);
515 if (inode) {
516 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
517 d_instantiate(dentry, inode);
518 dget(dentry); /* Extra count - pin the dentry in core */
519 error = 0;
520 }
521 return error;
522 }
523
524 static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
525 {
526 int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0);
527 if (!retval)
528 inc_nlink(dir);
529 return retval;
530 }
531
532 static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd)
533 {
534 return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0);
535 }
536
537 static int hugetlbfs_symlink(struct inode *dir,
538 struct dentry *dentry, const char *symname)
539 {
540 struct inode *inode;
541 int error = -ENOSPC;
542 gid_t gid;
543
544 if (dir->i_mode & S_ISGID)
545 gid = dir->i_gid;
546 else
547 gid = current_fsgid();
548
549 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(),
550 gid, S_IFLNK|S_IRWXUGO, 0);
551 if (inode) {
552 int l = strlen(symname)+1;
553 error = page_symlink(inode, symname, l);
554 if (!error) {
555 d_instantiate(dentry, inode);
556 dget(dentry);
557 } else
558 iput(inode);
559 }
560 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
561
562 return error;
563 }
564
565 /*
566 * mark the head page dirty
567 */
568 static int hugetlbfs_set_page_dirty(struct page *page)
569 {
570 struct page *head = compound_head(page);
571
572 SetPageDirty(head);
573 return 0;
574 }
575
576 static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
577 {
578 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
579 struct hstate *h = hstate_inode(dentry->d_inode);
580
581 buf->f_type = HUGETLBFS_MAGIC;
582 buf->f_bsize = huge_page_size(h);
583 if (sbinfo) {
584 spin_lock(&sbinfo->stat_lock);
585 /* If no limits set, just report 0 for max/free/used
586 * blocks, like simple_statfs() */
587 if (sbinfo->max_blocks >= 0) {
588 buf->f_blocks = sbinfo->max_blocks;
589 buf->f_bavail = buf->f_bfree = sbinfo->free_blocks;
590 buf->f_files = sbinfo->max_inodes;
591 buf->f_ffree = sbinfo->free_inodes;
592 }
593 spin_unlock(&sbinfo->stat_lock);
594 }
595 buf->f_namelen = NAME_MAX;
596 return 0;
597 }
598
599 static void hugetlbfs_put_super(struct super_block *sb)
600 {
601 struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb);
602
603 if (sbi) {
604 sb->s_fs_info = NULL;
605 kfree(sbi);
606 }
607 }
608
609 static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo)
610 {
611 if (sbinfo->free_inodes >= 0) {
612 spin_lock(&sbinfo->stat_lock);
613 if (unlikely(!sbinfo->free_inodes)) {
614 spin_unlock(&sbinfo->stat_lock);
615 return 0;
616 }
617 sbinfo->free_inodes--;
618 spin_unlock(&sbinfo->stat_lock);
619 }
620
621 return 1;
622 }
623
624 static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
625 {
626 if (sbinfo->free_inodes >= 0) {
627 spin_lock(&sbinfo->stat_lock);
628 sbinfo->free_inodes++;
629 spin_unlock(&sbinfo->stat_lock);
630 }
631 }
632
633
634 static struct kmem_cache *hugetlbfs_inode_cachep;
635
636 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
637 {
638 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
639 struct hugetlbfs_inode_info *p;
640
641 if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
642 return NULL;
643 p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL);
644 if (unlikely(!p)) {
645 hugetlbfs_inc_free_inodes(sbinfo);
646 return NULL;
647 }
648 return &p->vfs_inode;
649 }
650
651 static void hugetlbfs_destroy_inode(struct inode *inode)
652 {
653 hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
654 mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
655 kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
656 }
657
658 static const struct address_space_operations hugetlbfs_aops = {
659 .write_begin = hugetlbfs_write_begin,
660 .write_end = hugetlbfs_write_end,
661 .set_page_dirty = hugetlbfs_set_page_dirty,
662 };
663
664
665 static void init_once(void *foo)
666 {
667 struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
668
669 inode_init_once(&ei->vfs_inode);
670 }
671
672 const struct file_operations hugetlbfs_file_operations = {
673 .read = hugetlbfs_read,
674 .mmap = hugetlbfs_file_mmap,
675 .fsync = noop_fsync,
676 .get_unmapped_area = hugetlb_get_unmapped_area,
677 };
678
679 static const struct inode_operations hugetlbfs_dir_inode_operations = {
680 .create = hugetlbfs_create,
681 .lookup = simple_lookup,
682 .link = simple_link,
683 .unlink = simple_unlink,
684 .symlink = hugetlbfs_symlink,
685 .mkdir = hugetlbfs_mkdir,
686 .rmdir = simple_rmdir,
687 .mknod = hugetlbfs_mknod,
688 .rename = simple_rename,
689 .setattr = hugetlbfs_setattr,
690 };
691
692 static const struct inode_operations hugetlbfs_inode_operations = {
693 .setattr = hugetlbfs_setattr,
694 };
695
696 static const struct super_operations hugetlbfs_ops = {
697 .alloc_inode = hugetlbfs_alloc_inode,
698 .destroy_inode = hugetlbfs_destroy_inode,
699 .evict_inode = hugetlbfs_evict_inode,
700 .statfs = hugetlbfs_statfs,
701 .put_super = hugetlbfs_put_super,
702 .show_options = generic_show_options,
703 };
704
705 static int
706 hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
707 {
708 char *p, *rest;
709 substring_t args[MAX_OPT_ARGS];
710 int option;
711 unsigned long long size = 0;
712 enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = NO_SIZE;
713
714 if (!options)
715 return 0;
716
717 while ((p = strsep(&options, ",")) != NULL) {
718 int token;
719 if (!*p)
720 continue;
721
722 token = match_token(p, tokens, args);
723 switch (token) {
724 case Opt_uid:
725 if (match_int(&args[0], &option))
726 goto bad_val;
727 pconfig->uid = option;
728 break;
729
730 case Opt_gid:
731 if (match_int(&args[0], &option))
732 goto bad_val;
733 pconfig->gid = option;
734 break;
735
736 case Opt_mode:
737 if (match_octal(&args[0], &option))
738 goto bad_val;
739 pconfig->mode = option & 01777U;
740 break;
741
742 case Opt_size: {
743 /* memparse() will accept a K/M/G without a digit */
744 if (!isdigit(*args[0].from))
745 goto bad_val;
746 size = memparse(args[0].from, &rest);
747 setsize = SIZE_STD;
748 if (*rest == '%')
749 setsize = SIZE_PERCENT;
750 break;
751 }
752
753 case Opt_nr_inodes:
754 /* memparse() will accept a K/M/G without a digit */
755 if (!isdigit(*args[0].from))
756 goto bad_val;
757 pconfig->nr_inodes = memparse(args[0].from, &rest);
758 break;
759
760 case Opt_pagesize: {
761 unsigned long ps;
762 ps = memparse(args[0].from, &rest);
763 pconfig->hstate = size_to_hstate(ps);
764 if (!pconfig->hstate) {
765 printk(KERN_ERR
766 "hugetlbfs: Unsupported page size %lu MB\n",
767 ps >> 20);
768 return -EINVAL;
769 }
770 break;
771 }
772
773 default:
774 printk(KERN_ERR "hugetlbfs: Bad mount option: \"%s\"\n",
775 p);
776 return -EINVAL;
777 break;
778 }
779 }
780
781 /* Do size after hstate is set up */
782 if (setsize > NO_SIZE) {
783 struct hstate *h = pconfig->hstate;
784 if (setsize == SIZE_PERCENT) {
785 size <<= huge_page_shift(h);
786 size *= h->max_huge_pages;
787 do_div(size, 100);
788 }
789 pconfig->nr_blocks = (size >> huge_page_shift(h));
790 }
791
792 return 0;
793
794 bad_val:
795 printk(KERN_ERR "hugetlbfs: Bad value '%s' for mount option '%s'\n",
796 args[0].from, p);
797 return -EINVAL;
798 }
799
800 static int
801 hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
802 {
803 struct inode * inode;
804 struct dentry * root;
805 int ret;
806 struct hugetlbfs_config config;
807 struct hugetlbfs_sb_info *sbinfo;
808
809 save_mount_options(sb, data);
810
811 config.nr_blocks = -1; /* No limit on size by default */
812 config.nr_inodes = -1; /* No limit on number of inodes by default */
813 config.uid = current_fsuid();
814 config.gid = current_fsgid();
815 config.mode = 0755;
816 config.hstate = &default_hstate;
817 ret = hugetlbfs_parse_options(data, &config);
818 if (ret)
819 return ret;
820
821 sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL);
822 if (!sbinfo)
823 return -ENOMEM;
824 sb->s_fs_info = sbinfo;
825 sbinfo->hstate = config.hstate;
826 spin_lock_init(&sbinfo->stat_lock);
827 sbinfo->max_blocks = config.nr_blocks;
828 sbinfo->free_blocks = config.nr_blocks;
829 sbinfo->max_inodes = config.nr_inodes;
830 sbinfo->free_inodes = config.nr_inodes;
831 sb->s_maxbytes = MAX_LFS_FILESIZE;
832 sb->s_blocksize = huge_page_size(config.hstate);
833 sb->s_blocksize_bits = huge_page_shift(config.hstate);
834 sb->s_magic = HUGETLBFS_MAGIC;
835 sb->s_op = &hugetlbfs_ops;
836 sb->s_time_gran = 1;
837 inode = hugetlbfs_get_inode(sb, config.uid, config.gid,
838 S_IFDIR | config.mode, 0);
839 if (!inode)
840 goto out_free;
841
842 root = d_alloc_root(inode);
843 if (!root) {
844 iput(inode);
845 goto out_free;
846 }
847 sb->s_root = root;
848 return 0;
849 out_free:
850 kfree(sbinfo);
851 return -ENOMEM;
852 }
853
854 int hugetlb_get_quota(struct address_space *mapping, long delta)
855 {
856 int ret = 0;
857 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb);
858
859 if (sbinfo->free_blocks > -1) {
860 spin_lock(&sbinfo->stat_lock);
861 if (sbinfo->free_blocks - delta >= 0)
862 sbinfo->free_blocks -= delta;
863 else
864 ret = -ENOMEM;
865 spin_unlock(&sbinfo->stat_lock);
866 }
867
868 return ret;
869 }
870
871 void hugetlb_put_quota(struct address_space *mapping, long delta)
872 {
873 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb);
874
875 if (sbinfo->free_blocks > -1) {
876 spin_lock(&sbinfo->stat_lock);
877 sbinfo->free_blocks += delta;
878 spin_unlock(&sbinfo->stat_lock);
879 }
880 }
881
882 static int hugetlbfs_get_sb(struct file_system_type *fs_type,
883 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
884 {
885 return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super, mnt);
886 }
887
888 static struct file_system_type hugetlbfs_fs_type = {
889 .name = "hugetlbfs",
890 .get_sb = hugetlbfs_get_sb,
891 .kill_sb = kill_litter_super,
892 };
893
894 static struct vfsmount *hugetlbfs_vfsmount;
895
896 static int can_do_hugetlb_shm(void)
897 {
898 return capable(CAP_IPC_LOCK) || in_group_p(sysctl_hugetlb_shm_group);
899 }
900
901 struct file *hugetlb_file_setup(const char *name, size_t size, int acctflag,
902 struct user_struct **user, int creat_flags)
903 {
904 int error = -ENOMEM;
905 struct file *file;
906 struct inode *inode;
907 struct path path;
908 struct dentry *root;
909 struct qstr quick_string;
910
911 *user = NULL;
912 if (!hugetlbfs_vfsmount)
913 return ERR_PTR(-ENOENT);
914
915 if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) {
916 *user = current_user();
917 if (user_shm_lock(size, *user)) {
918 WARN_ONCE(1,
919 "Using mlock ulimits for SHM_HUGETLB deprecated\n");
920 } else {
921 *user = NULL;
922 return ERR_PTR(-EPERM);
923 }
924 }
925
926 root = hugetlbfs_vfsmount->mnt_root;
927 quick_string.name = name;
928 quick_string.len = strlen(quick_string.name);
929 quick_string.hash = 0;
930 path.dentry = d_alloc(root, &quick_string);
931 if (!path.dentry)
932 goto out_shm_unlock;
933
934 path.mnt = mntget(hugetlbfs_vfsmount);
935 error = -ENOSPC;
936 inode = hugetlbfs_get_inode(root->d_sb, current_fsuid(),
937 current_fsgid(), S_IFREG | S_IRWXUGO, 0);
938 if (!inode)
939 goto out_dentry;
940
941 error = -ENOMEM;
942 if (hugetlb_reserve_pages(inode, 0,
943 size >> huge_page_shift(hstate_inode(inode)), NULL,
944 acctflag))
945 goto out_inode;
946
947 d_instantiate(path.dentry, inode);
948 inode->i_size = size;
949 inode->i_nlink = 0;
950
951 error = -ENFILE;
952 file = alloc_file(&path, FMODE_WRITE | FMODE_READ,
953 &hugetlbfs_file_operations);
954 if (!file)
955 goto out_dentry; /* inode is already attached */
956
957 return file;
958
959 out_inode:
960 iput(inode);
961 out_dentry:
962 path_put(&path);
963 out_shm_unlock:
964 if (*user) {
965 user_shm_unlock(size, *user);
966 *user = NULL;
967 }
968 return ERR_PTR(error);
969 }
970
971 static int __init init_hugetlbfs_fs(void)
972 {
973 int error;
974 struct vfsmount *vfsmount;
975
976 error = bdi_init(&hugetlbfs_backing_dev_info);
977 if (error)
978 return error;
979
980 hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
981 sizeof(struct hugetlbfs_inode_info),
982 0, 0, init_once);
983 if (hugetlbfs_inode_cachep == NULL)
984 goto out2;
985
986 error = register_filesystem(&hugetlbfs_fs_type);
987 if (error)
988 goto out;
989
990 vfsmount = kern_mount(&hugetlbfs_fs_type);
991
992 if (!IS_ERR(vfsmount)) {
993 hugetlbfs_vfsmount = vfsmount;
994 return 0;
995 }
996
997 error = PTR_ERR(vfsmount);
998
999 out:
1000 if (error)
1001 kmem_cache_destroy(hugetlbfs_inode_cachep);
1002 out2:
1003 bdi_destroy(&hugetlbfs_backing_dev_info);
1004 return error;
1005 }
1006
1007 static void __exit exit_hugetlbfs_fs(void)
1008 {
1009 kmem_cache_destroy(hugetlbfs_inode_cachep);
1010 unregister_filesystem(&hugetlbfs_fs_type);
1011 bdi_destroy(&hugetlbfs_backing_dev_info);
1012 }
1013
1014 module_init(init_hugetlbfs_fs)
1015 module_exit(exit_hugetlbfs_fs)
1016
1017 MODULE_LICENSE("GPL");
Tomato firmware and modifications.