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nfs41: implement DESTROY_CLIENTID operation
[linux-btrfs-devel.git] / fs / hugetlbfs / inode.c
blob87b6e0421c12b8a44b75bf0cf79c198893303552
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 #include <linux/migrate.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 delete_from_page_cache(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 mutex_lock(&mapping->i_mmap_mutex);
416 if (!prio_tree_empty(&mapping->i_mmap))
417 hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
418 mutex_unlock(&mapping->i_mmap_mutex);
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_ino = get_next_ino();
459 inode->i_mode = mode;
460 inode->i_uid = uid;
461 inode->i_gid = gid;
462 inode->i_mapping->a_ops = &hugetlbfs_aops;
463 inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info;
464 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
465 INIT_LIST_HEAD(&inode->i_mapping->private_list);
466 info = HUGETLBFS_I(inode);
467 /*
468 * The policy is initialized here even if we are creating a
469 * private inode because initialization simply creates an
470 * an empty rb tree and calls spin_lock_init(), later when we
471 * call mpol_free_shared_policy() it will just return because
472 * the rb tree will still be empty.
473 */
474 mpol_shared_policy_init(&info->policy, NULL);
475 switch (mode & S_IFMT) {
476 default:
477 init_special_inode(inode, mode, dev);
478 break;
479 case S_IFREG:
480 inode->i_op = &hugetlbfs_inode_operations;
481 inode->i_fop = &hugetlbfs_file_operations;
482 break;
483 case S_IFDIR:
484 inode->i_op = &hugetlbfs_dir_inode_operations;
485 inode->i_fop = &simple_dir_operations;
486
487 /* directory inodes start off with i_nlink == 2 (for "." entry) */
488 inc_nlink(inode);
489 break;
490 case S_IFLNK:
491 inode->i_op = &page_symlink_inode_operations;
492 break;
493 }
494 }
495 return inode;
496 }
497
498 /*
499 * File creation. Allocate an inode, and we're done..
500 */
501 static int hugetlbfs_mknod(struct inode *dir,
502 struct dentry *dentry, int mode, dev_t dev)
503 {
504 struct inode *inode;
505 int error = -ENOSPC;
506 gid_t gid;
507
508 if (dir->i_mode & S_ISGID) {
509 gid = dir->i_gid;
510 if (S_ISDIR(mode))
511 mode |= S_ISGID;
512 } else {
513 gid = current_fsgid();
514 }
515 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), gid, mode, dev);
516 if (inode) {
517 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
518 d_instantiate(dentry, inode);
519 dget(dentry); /* Extra count - pin the dentry in core */
520 error = 0;
521 }
522 return error;
523 }
524
525 static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
526 {
527 int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0);
528 if (!retval)
529 inc_nlink(dir);
530 return retval;
531 }
532
533 static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd)
534 {
535 return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0);
536 }
537
538 static int hugetlbfs_symlink(struct inode *dir,
539 struct dentry *dentry, const char *symname)
540 {
541 struct inode *inode;
542 int error = -ENOSPC;
543 gid_t gid;
544
545 if (dir->i_mode & S_ISGID)
546 gid = dir->i_gid;
547 else
548 gid = current_fsgid();
549
550 inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(),
551 gid, S_IFLNK|S_IRWXUGO, 0);
552 if (inode) {
553 int l = strlen(symname)+1;
554 error = page_symlink(inode, symname, l);
555 if (!error) {
556 d_instantiate(dentry, inode);
557 dget(dentry);
558 } else
559 iput(inode);
560 }
561 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
562
563 return error;
564 }
565
566 /*
567 * mark the head page dirty
568 */
569 static int hugetlbfs_set_page_dirty(struct page *page)
570 {
571 struct page *head = compound_head(page);
572
573 SetPageDirty(head);
574 return 0;
575 }
576
577 static int hugetlbfs_migrate_page(struct address_space *mapping,
578 struct page *newpage, struct page *page)
579 {
580 int rc;
581
582 rc = migrate_huge_page_move_mapping(mapping, newpage, page);
583 if (rc)
584 return rc;
585 migrate_page_copy(newpage, page);
586
587 return 0;
588 }
589
590 static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
591 {
592 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
593 struct hstate *h = hstate_inode(dentry->d_inode);
594
595 buf->f_type = HUGETLBFS_MAGIC;
596 buf->f_bsize = huge_page_size(h);
597 if (sbinfo) {
598 spin_lock(&sbinfo->stat_lock);
599 /* If no limits set, just report 0 for max/free/used
600 * blocks, like simple_statfs() */
601 if (sbinfo->max_blocks >= 0) {
602 buf->f_blocks = sbinfo->max_blocks;
603 buf->f_bavail = buf->f_bfree = sbinfo->free_blocks;
604 buf->f_files = sbinfo->max_inodes;
605 buf->f_ffree = sbinfo->free_inodes;
606 }
607 spin_unlock(&sbinfo->stat_lock);
608 }
609 buf->f_namelen = NAME_MAX;
610 return 0;
611 }
612
613 static void hugetlbfs_put_super(struct super_block *sb)
614 {
615 struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb);
616
617 if (sbi) {
618 sb->s_fs_info = NULL;
619 kfree(sbi);
620 }
621 }
622
623 static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo)
624 {
625 if (sbinfo->free_inodes >= 0) {
626 spin_lock(&sbinfo->stat_lock);
627 if (unlikely(!sbinfo->free_inodes)) {
628 spin_unlock(&sbinfo->stat_lock);
629 return 0;
630 }
631 sbinfo->free_inodes--;
632 spin_unlock(&sbinfo->stat_lock);
633 }
634
635 return 1;
636 }
637
638 static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
639 {
640 if (sbinfo->free_inodes >= 0) {
641 spin_lock(&sbinfo->stat_lock);
642 sbinfo->free_inodes++;
643 spin_unlock(&sbinfo->stat_lock);
644 }
645 }
646
647
648 static struct kmem_cache *hugetlbfs_inode_cachep;
649
650 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
651 {
652 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
653 struct hugetlbfs_inode_info *p;
654
655 if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
656 return NULL;
657 p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL);
658 if (unlikely(!p)) {
659 hugetlbfs_inc_free_inodes(sbinfo);
660 return NULL;
661 }
662 return &p->vfs_inode;
663 }
664
665 static void hugetlbfs_i_callback(struct rcu_head *head)
666 {
667 struct inode *inode = container_of(head, struct inode, i_rcu);
668 INIT_LIST_HEAD(&inode->i_dentry);
669 kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
670 }
671
672 static void hugetlbfs_destroy_inode(struct inode *inode)
673 {
674 hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
675 mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
676 call_rcu(&inode->i_rcu, hugetlbfs_i_callback);
677 }
678
679 static const struct address_space_operations hugetlbfs_aops = {
680 .write_begin = hugetlbfs_write_begin,
681 .write_end = hugetlbfs_write_end,
682 .set_page_dirty = hugetlbfs_set_page_dirty,
683 .migratepage = hugetlbfs_migrate_page,
684 };
685
686
687 static void init_once(void *foo)
688 {
689 struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
690
691 inode_init_once(&ei->vfs_inode);
692 }
693
694 const struct file_operations hugetlbfs_file_operations = {
695 .read = hugetlbfs_read,
696 .mmap = hugetlbfs_file_mmap,
697 .fsync = noop_fsync,
698 .get_unmapped_area = hugetlb_get_unmapped_area,
699 .llseek = default_llseek,
700 };
701
702 static const struct inode_operations hugetlbfs_dir_inode_operations = {
703 .create = hugetlbfs_create,
704 .lookup = simple_lookup,
705 .link = simple_link,
706 .unlink = simple_unlink,
707 .symlink = hugetlbfs_symlink,
708 .mkdir = hugetlbfs_mkdir,
709 .rmdir = simple_rmdir,
710 .mknod = hugetlbfs_mknod,
711 .rename = simple_rename,
712 .setattr = hugetlbfs_setattr,
713 };
714
715 static const struct inode_operations hugetlbfs_inode_operations = {
716 .setattr = hugetlbfs_setattr,
717 };
718
719 static const struct super_operations hugetlbfs_ops = {
720 .alloc_inode = hugetlbfs_alloc_inode,
721 .destroy_inode = hugetlbfs_destroy_inode,
722 .evict_inode = hugetlbfs_evict_inode,
723 .statfs = hugetlbfs_statfs,
724 .put_super = hugetlbfs_put_super,
725 .show_options = generic_show_options,
726 };
727
728 static int
729 hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
730 {
731 char *p, *rest;
732 substring_t args[MAX_OPT_ARGS];
733 int option;
734 unsigned long long size = 0;
735 enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = NO_SIZE;
736
737 if (!options)
738 return 0;
739
740 while ((p = strsep(&options, ",")) != NULL) {
741 int token;
742 if (!*p)
743 continue;
744
745 token = match_token(p, tokens, args);
746 switch (token) {
747 case Opt_uid:
748 if (match_int(&args[0], &option))
749 goto bad_val;
750 pconfig->uid = option;
751 break;
752
753 case Opt_gid:
754 if (match_int(&args[0], &option))
755 goto bad_val;
756 pconfig->gid = option;
757 break;
758
759 case Opt_mode:
760 if (match_octal(&args[0], &option))
761 goto bad_val;
762 pconfig->mode = option & 01777U;
763 break;
764
765 case Opt_size: {
766 /* memparse() will accept a K/M/G without a digit */
767 if (!isdigit(*args[0].from))
768 goto bad_val;
769 size = memparse(args[0].from, &rest);
770 setsize = SIZE_STD;
771 if (*rest == '%')
772 setsize = SIZE_PERCENT;
773 break;
774 }
775
776 case Opt_nr_inodes:
777 /* memparse() will accept a K/M/G without a digit */
778 if (!isdigit(*args[0].from))
779 goto bad_val;
780 pconfig->nr_inodes = memparse(args[0].from, &rest);
781 break;
782
783 case Opt_pagesize: {
784 unsigned long ps;
785 ps = memparse(args[0].from, &rest);
786 pconfig->hstate = size_to_hstate(ps);
787 if (!pconfig->hstate) {
788 printk(KERN_ERR
789 "hugetlbfs: Unsupported page size %lu MB\n",
790 ps >> 20);
791 return -EINVAL;
792 }
793 break;
794 }
795
796 default:
797 printk(KERN_ERR "hugetlbfs: Bad mount option: \"%s\"\n",
798 p);
799 return -EINVAL;
800 break;
801 }
802 }
803
804 /* Do size after hstate is set up */
805 if (setsize > NO_SIZE) {
806 struct hstate *h = pconfig->hstate;
807 if (setsize == SIZE_PERCENT) {
808 size <<= huge_page_shift(h);
809 size *= h->max_huge_pages;
810 do_div(size, 100);
811 }
812 pconfig->nr_blocks = (size >> huge_page_shift(h));
813 }
814
815 return 0;
816
817 bad_val:
818 printk(KERN_ERR "hugetlbfs: Bad value '%s' for mount option '%s'\n",
819 args[0].from, p);
820 return -EINVAL;
821 }
822
823 static int
824 hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
825 {
826 struct inode * inode;
827 struct dentry * root;
828 int ret;
829 struct hugetlbfs_config config;
830 struct hugetlbfs_sb_info *sbinfo;
831
832 save_mount_options(sb, data);
833
834 config.nr_blocks = -1; /* No limit on size by default */
835 config.nr_inodes = -1; /* No limit on number of inodes by default */
836 config.uid = current_fsuid();
837 config.gid = current_fsgid();
838 config.mode = 0755;
839 config.hstate = &default_hstate;
840 ret = hugetlbfs_parse_options(data, &config);
841 if (ret)
842 return ret;
843
844 sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL);
845 if (!sbinfo)
846 return -ENOMEM;
847 sb->s_fs_info = sbinfo;
848 sbinfo->hstate = config.hstate;
849 spin_lock_init(&sbinfo->stat_lock);
850 sbinfo->max_blocks = config.nr_blocks;
851 sbinfo->free_blocks = config.nr_blocks;
852 sbinfo->max_inodes = config.nr_inodes;
853 sbinfo->free_inodes = config.nr_inodes;
854 sb->s_maxbytes = MAX_LFS_FILESIZE;
855 sb->s_blocksize = huge_page_size(config.hstate);
856 sb->s_blocksize_bits = huge_page_shift(config.hstate);
857 sb->s_magic = HUGETLBFS_MAGIC;
858 sb->s_op = &hugetlbfs_ops;
859 sb->s_time_gran = 1;
860 inode = hugetlbfs_get_inode(sb, config.uid, config.gid,
861 S_IFDIR | config.mode, 0);
862 if (!inode)
863 goto out_free;
864
865 root = d_alloc_root(inode);
866 if (!root) {
867 iput(inode);
868 goto out_free;
869 }
870 sb->s_root = root;
871 return 0;
872 out_free:
873 kfree(sbinfo);
874 return -ENOMEM;
875 }
876
877 int hugetlb_get_quota(struct address_space *mapping, long delta)
878 {
879 int ret = 0;
880 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb);
881
882 if (sbinfo->free_blocks > -1) {
883 spin_lock(&sbinfo->stat_lock);
884 if (sbinfo->free_blocks - delta >= 0)
885 sbinfo->free_blocks -= delta;
886 else
887 ret = -ENOMEM;
888 spin_unlock(&sbinfo->stat_lock);
889 }
890
891 return ret;
892 }
893
894 void hugetlb_put_quota(struct address_space *mapping, long delta)
895 {
896 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb);
897
898 if (sbinfo->free_blocks > -1) {
899 spin_lock(&sbinfo->stat_lock);
900 sbinfo->free_blocks += delta;
901 spin_unlock(&sbinfo->stat_lock);
902 }
903 }
904
905 static struct dentry *hugetlbfs_mount(struct file_system_type *fs_type,
906 int flags, const char *dev_name, void *data)
907 {
908 return mount_nodev(fs_type, flags, data, hugetlbfs_fill_super);
909 }
910
911 static struct file_system_type hugetlbfs_fs_type = {
912 .name = "hugetlbfs",
913 .mount = hugetlbfs_mount,
914 .kill_sb = kill_litter_super,
915 };
916
917 static struct vfsmount *hugetlbfs_vfsmount;
918
919 static int can_do_hugetlb_shm(void)
920 {
921 return capable(CAP_IPC_LOCK) || in_group_p(sysctl_hugetlb_shm_group);
922 }
923
924 struct file *hugetlb_file_setup(const char *name, size_t size,
925 vm_flags_t acctflag,
926 struct user_struct **user, int creat_flags)
927 {
928 int error = -ENOMEM;
929 struct file *file;
930 struct inode *inode;
931 struct path path;
932 struct dentry *root;
933 struct qstr quick_string;
934
935 *user = NULL;
936 if (!hugetlbfs_vfsmount)
937 return ERR_PTR(-ENOENT);
938
939 if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) {
940 *user = current_user();
941 if (user_shm_lock(size, *user)) {
942 printk_once(KERN_WARNING "Using mlock ulimits for SHM_HUGETLB is deprecated\n");
943 } else {
944 *user = NULL;
945 return ERR_PTR(-EPERM);
946 }
947 }
948
949 root = hugetlbfs_vfsmount->mnt_root;
950 quick_string.name = name;
951 quick_string.len = strlen(quick_string.name);
952 quick_string.hash = 0;
953 path.dentry = d_alloc(root, &quick_string);
954 if (!path.dentry)
955 goto out_shm_unlock;
956
957 path.mnt = mntget(hugetlbfs_vfsmount);
958 error = -ENOSPC;
959 inode = hugetlbfs_get_inode(root->d_sb, current_fsuid(),
960 current_fsgid(), S_IFREG | S_IRWXUGO, 0);
961 if (!inode)
962 goto out_dentry;
963
964 error = -ENOMEM;
965 if (hugetlb_reserve_pages(inode, 0,
966 size >> huge_page_shift(hstate_inode(inode)), NULL,
967 acctflag))
968 goto out_inode;
969
970 d_instantiate(path.dentry, inode);
971 inode->i_size = size;
972 inode->i_nlink = 0;
973
974 error = -ENFILE;
975 file = alloc_file(&path, FMODE_WRITE | FMODE_READ,
976 &hugetlbfs_file_operations);
977 if (!file)
978 goto out_dentry; /* inode is already attached */
979
980 return file;
981
982 out_inode:
983 iput(inode);
984 out_dentry:
985 path_put(&path);
986 out_shm_unlock:
987 if (*user) {
988 user_shm_unlock(size, *user);
989 *user = NULL;
990 }
991 return ERR_PTR(error);
992 }
993
994 static int __init init_hugetlbfs_fs(void)
995 {
996 int error;
997 struct vfsmount *vfsmount;
998
999 error = bdi_init(&hugetlbfs_backing_dev_info);
1000 if (error)
1001 return error;
1002
1003 hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
1004 sizeof(struct hugetlbfs_inode_info),
1005 0, 0, init_once);
1006 if (hugetlbfs_inode_cachep == NULL)
1007 goto out2;
1008
1009 error = register_filesystem(&hugetlbfs_fs_type);
1010 if (error)
1011 goto out;
1012
1013 vfsmount = kern_mount(&hugetlbfs_fs_type);
1014
1015 if (!IS_ERR(vfsmount)) {
1016 hugetlbfs_vfsmount = vfsmount;
1017 return 0;
1018 }
1019
1020 error = PTR_ERR(vfsmount);
1021
1022 out:
1023 if (error)
1024 kmem_cache_destroy(hugetlbfs_inode_cachep);
1025 out2:
1026 bdi_destroy(&hugetlbfs_backing_dev_info);
1027 return error;
1028 }
1029
1030 static void __exit exit_hugetlbfs_fs(void)
1031 {
1032 kmem_cache_destroy(hugetlbfs_inode_cachep);
1033 kern_unmount(hugetlbfs_vfsmount);
1034 unregister_filesystem(&hugetlbfs_fs_type);
1035 bdi_destroy(&hugetlbfs_backing_dev_info);
1036 }
1037
1038 module_init(init_hugetlbfs_fs)
1039 module_exit(exit_hugetlbfs_fs)
1040
1041 MODULE_LICENSE("GPL");
Linux Btrfs Development