hugetlbfs: return negative error code for bad mount option
[linux-2.6.git] / fs / hugetlbfs / inode.c
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
34 #include <asm/uaccess.h>
35
36 /* some random number */
37 #define HUGETLBFS_MAGIC 0x958458f6
38
39 static const struct super_operations hugetlbfs_ops;
40 static const struct address_space_operations hugetlbfs_aops;
41 const struct file_operations hugetlbfs_file_operations;
42 static const struct inode_operations hugetlbfs_dir_inode_operations;
43 static const struct inode_operations hugetlbfs_inode_operations;
44
45 static struct backing_dev_info hugetlbfs_backing_dev_info = {
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 /*
316  * Read a page. Again trivial. If it didn't already exist
317  * in the page cache, it is zero-filled.
318  */
319 static int hugetlbfs_readpage(struct file *file, struct page * page)
320 {
321         unlock_page(page);
322         return -EINVAL;
323 }
324
325 static int hugetlbfs_write_begin(struct file *file,
326                         struct address_space *mapping,
327                         loff_t pos, unsigned len, unsigned flags,
328                         struct page **pagep, void **fsdata)
329 {
330         return -EINVAL;
331 }
332
333 static int hugetlbfs_write_end(struct file *file, struct address_space *mapping,
334                         loff_t pos, unsigned len, unsigned copied,
335                         struct page *page, void *fsdata)
336 {
337         BUG();
338         return -EINVAL;
339 }
340
341 static void truncate_huge_page(struct page *page)
342 {
343         cancel_dirty_page(page, /* No IO accounting for huge pages? */0);
344         ClearPageUptodate(page);
345         remove_from_page_cache(page);
346         put_page(page);
347 }
348
349 static void truncate_hugepages(struct inode *inode, loff_t lstart)
350 {
351         struct hstate *h = hstate_inode(inode);
352         struct address_space *mapping = &inode->i_data;
353         const pgoff_t start = lstart >> huge_page_shift(h);
354         struct pagevec pvec;
355         pgoff_t next;
356         int i, freed = 0;
357
358         pagevec_init(&pvec, 0);
359         next = start;
360         while (1) {
361                 if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
362                         if (next == start)
363                                 break;
364                         next = start;
365                         continue;
366                 }
367
368                 for (i = 0; i < pagevec_count(&pvec); ++i) {
369                         struct page *page = pvec.pages[i];
370
371                         lock_page(page);
372                         if (page->index > next)
373                                 next = page->index;
374                         ++next;
375                         truncate_huge_page(page);
376                         unlock_page(page);
377                         freed++;
378                 }
379                 huge_pagevec_release(&pvec);
380         }
381         BUG_ON(!lstart && mapping->nrpages);
382         hugetlb_unreserve_pages(inode, start, freed);
383 }
384
385 static void hugetlbfs_delete_inode(struct inode *inode)
386 {
387         truncate_hugepages(inode, 0);
388         clear_inode(inode);
389 }
390
391 static void hugetlbfs_forget_inode(struct inode *inode) __releases(inode_lock)
392 {
393         struct super_block *sb = inode->i_sb;
394
395         if (!hlist_unhashed(&inode->i_hash)) {
396                 if (!(inode->i_state & (I_DIRTY|I_SYNC)))
397                         list_move(&inode->i_list, &inode_unused);
398                 inodes_stat.nr_unused++;
399                 if (!sb || (sb->s_flags & MS_ACTIVE)) {
400                         spin_unlock(&inode_lock);
401                         return;
402                 }
403                 inode->i_state |= I_WILL_FREE;
404                 spin_unlock(&inode_lock);
405                 /*
406                  * write_inode_now is a noop as we set BDI_CAP_NO_WRITEBACK
407                  * in our backing_dev_info.
408                  */
409                 write_inode_now(inode, 1);
410                 spin_lock(&inode_lock);
411                 inode->i_state &= ~I_WILL_FREE;
412                 inodes_stat.nr_unused--;
413                 hlist_del_init(&inode->i_hash);
414         }
415         list_del_init(&inode->i_list);
416         list_del_init(&inode->i_sb_list);
417         inode->i_state |= I_FREEING;
418         inodes_stat.nr_inodes--;
419         spin_unlock(&inode_lock);
420         truncate_hugepages(inode, 0);
421         clear_inode(inode);
422         destroy_inode(inode);
423 }
424
425 static void hugetlbfs_drop_inode(struct inode *inode)
426 {
427         if (!inode->i_nlink)
428                 generic_delete_inode(inode);
429         else
430                 hugetlbfs_forget_inode(inode);
431 }
432
433 static inline void
434 hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff)
435 {
436         struct vm_area_struct *vma;
437         struct prio_tree_iter iter;
438
439         vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) {
440                 unsigned long v_offset;
441
442                 /*
443                  * Can the expression below overflow on 32-bit arches?
444                  * No, because the prio_tree returns us only those vmas
445                  * which overlap the truncated area starting at pgoff,
446                  * and no vma on a 32-bit arch can span beyond the 4GB.
447                  */
448                 if (vma->vm_pgoff < pgoff)
449                         v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT;
450                 else
451                         v_offset = 0;
452
453                 __unmap_hugepage_range(vma,
454                                 vma->vm_start + v_offset, vma->vm_end, NULL);
455         }
456 }
457
458 static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
459 {
460         pgoff_t pgoff;
461         struct address_space *mapping = inode->i_mapping;
462         struct hstate *h = hstate_inode(inode);
463
464         BUG_ON(offset & ~huge_page_mask(h));
465         pgoff = offset >> PAGE_SHIFT;
466
467         i_size_write(inode, offset);
468         spin_lock(&mapping->i_mmap_lock);
469         if (!prio_tree_empty(&mapping->i_mmap))
470                 hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
471         spin_unlock(&mapping->i_mmap_lock);
472         truncate_hugepages(inode, offset);
473         return 0;
474 }
475
476 static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
477 {
478         struct inode *inode = dentry->d_inode;
479         struct hstate *h = hstate_inode(inode);
480         int error;
481         unsigned int ia_valid = attr->ia_valid;
482
483         BUG_ON(!inode);
484
485         error = inode_change_ok(inode, attr);
486         if (error)
487                 goto out;
488
489         if (ia_valid & ATTR_SIZE) {
490                 error = -EINVAL;
491                 if (!(attr->ia_size & ~huge_page_mask(h)))
492                         error = hugetlb_vmtruncate(inode, attr->ia_size);
493                 if (error)
494                         goto out;
495                 attr->ia_valid &= ~ATTR_SIZE;
496         }
497         error = inode_setattr(inode, attr);
498 out:
499         return error;
500 }
501
502 static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid, 
503                                         gid_t gid, int mode, dev_t dev)
504 {
505         struct inode *inode;
506
507         inode = new_inode(sb);
508         if (inode) {
509                 struct hugetlbfs_inode_info *info;
510                 inode->i_mode = mode;
511                 inode->i_uid = uid;
512                 inode->i_gid = gid;
513                 inode->i_mapping->a_ops = &hugetlbfs_aops;
514                 inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info;
515                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
516                 INIT_LIST_HEAD(&inode->i_mapping->private_list);
517                 info = HUGETLBFS_I(inode);
518                 mpol_shared_policy_init(&info->policy, NULL);
519                 switch (mode & S_IFMT) {
520                 default:
521                         init_special_inode(inode, mode, dev);
522                         break;
523                 case S_IFREG:
524                         inode->i_op = &hugetlbfs_inode_operations;
525                         inode->i_fop = &hugetlbfs_file_operations;
526                         break;
527                 case S_IFDIR:
528                         inode->i_op = &hugetlbfs_dir_inode_operations;
529                         inode->i_fop = &simple_dir_operations;
530
531                         /* directory inodes start off with i_nlink == 2 (for "." entry) */
532                         inc_nlink(inode);
533                         break;
534                 case S_IFLNK:
535                         inode->i_op = &page_symlink_inode_operations;
536                         break;
537                 }
538         }
539         return inode;
540 }
541
542 /*
543  * File creation. Allocate an inode, and we're done..
544  */
545 static int hugetlbfs_mknod(struct inode *dir,
546                         struct dentry *dentry, int mode, dev_t dev)
547 {
548         struct inode *inode;
549         int error = -ENOSPC;
550         gid_t gid;
551
552         if (dir->i_mode & S_ISGID) {
553                 gid = dir->i_gid;
554                 if (S_ISDIR(mode))
555                         mode |= S_ISGID;
556         } else {
557                 gid = current_fsgid();
558         }
559         inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), gid, mode, dev);
560         if (inode) {
561                 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
562                 d_instantiate(dentry, inode);
563                 dget(dentry);   /* Extra count - pin the dentry in core */
564                 error = 0;
565         }
566         return error;
567 }
568
569 static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
570 {
571         int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0);
572         if (!retval)
573                 inc_nlink(dir);
574         return retval;
575 }
576
577 static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd)
578 {
579         return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0);
580 }
581
582 static int hugetlbfs_symlink(struct inode *dir,
583                         struct dentry *dentry, const char *symname)
584 {
585         struct inode *inode;
586         int error = -ENOSPC;
587         gid_t gid;
588
589         if (dir->i_mode & S_ISGID)
590                 gid = dir->i_gid;
591         else
592                 gid = current_fsgid();
593
594         inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(),
595                                         gid, S_IFLNK|S_IRWXUGO, 0);
596         if (inode) {
597                 int l = strlen(symname)+1;
598                 error = page_symlink(inode, symname, l);
599                 if (!error) {
600                         d_instantiate(dentry, inode);
601                         dget(dentry);
602                 } else
603                         iput(inode);
604         }
605         dir->i_ctime = dir->i_mtime = CURRENT_TIME;
606
607         return error;
608 }
609
610 /*
611  * mark the head page dirty
612  */
613 static int hugetlbfs_set_page_dirty(struct page *page)
614 {
615         struct page *head = compound_head(page);
616
617         SetPageDirty(head);
618         return 0;
619 }
620
621 static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
622 {
623         struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
624         struct hstate *h = hstate_inode(dentry->d_inode);
625
626         buf->f_type = HUGETLBFS_MAGIC;
627         buf->f_bsize = huge_page_size(h);
628         if (sbinfo) {
629                 spin_lock(&sbinfo->stat_lock);
630                 /* If no limits set, just report 0 for max/free/used
631                  * blocks, like simple_statfs() */
632                 if (sbinfo->max_blocks >= 0) {
633                         buf->f_blocks = sbinfo->max_blocks;
634                         buf->f_bavail = buf->f_bfree = sbinfo->free_blocks;
635                         buf->f_files = sbinfo->max_inodes;
636                         buf->f_ffree = sbinfo->free_inodes;
637                 }
638                 spin_unlock(&sbinfo->stat_lock);
639         }
640         buf->f_namelen = NAME_MAX;
641         return 0;
642 }
643
644 static void hugetlbfs_put_super(struct super_block *sb)
645 {
646         struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb);
647
648         if (sbi) {
649                 sb->s_fs_info = NULL;
650                 kfree(sbi);
651         }
652 }
653
654 static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo)
655 {
656         if (sbinfo->free_inodes >= 0) {
657                 spin_lock(&sbinfo->stat_lock);
658                 if (unlikely(!sbinfo->free_inodes)) {
659                         spin_unlock(&sbinfo->stat_lock);
660                         return 0;
661                 }
662                 sbinfo->free_inodes--;
663                 spin_unlock(&sbinfo->stat_lock);
664         }
665
666         return 1;
667 }
668
669 static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
670 {
671         if (sbinfo->free_inodes >= 0) {
672                 spin_lock(&sbinfo->stat_lock);
673                 sbinfo->free_inodes++;
674                 spin_unlock(&sbinfo->stat_lock);
675         }
676 }
677
678
679 static struct kmem_cache *hugetlbfs_inode_cachep;
680
681 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
682 {
683         struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
684         struct hugetlbfs_inode_info *p;
685
686         if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
687                 return NULL;
688         p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL);
689         if (unlikely(!p)) {
690                 hugetlbfs_inc_free_inodes(sbinfo);
691                 return NULL;
692         }
693         return &p->vfs_inode;
694 }
695
696 static void hugetlbfs_destroy_inode(struct inode *inode)
697 {
698         hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
699         mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
700         kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
701 }
702
703 static const struct address_space_operations hugetlbfs_aops = {
704         .readpage       = hugetlbfs_readpage,
705         .write_begin    = hugetlbfs_write_begin,
706         .write_end      = hugetlbfs_write_end,
707         .set_page_dirty = hugetlbfs_set_page_dirty,
708 };
709
710
711 static void init_once(void *foo)
712 {
713         struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
714
715         inode_init_once(&ei->vfs_inode);
716 }
717
718 const struct file_operations hugetlbfs_file_operations = {
719         .read                   = hugetlbfs_read,
720         .mmap                   = hugetlbfs_file_mmap,
721         .fsync                  = simple_sync_file,
722         .get_unmapped_area      = hugetlb_get_unmapped_area,
723 };
724
725 static const struct inode_operations hugetlbfs_dir_inode_operations = {
726         .create         = hugetlbfs_create,
727         .lookup         = simple_lookup,
728         .link           = simple_link,
729         .unlink         = simple_unlink,
730         .symlink        = hugetlbfs_symlink,
731         .mkdir          = hugetlbfs_mkdir,
732         .rmdir          = simple_rmdir,
733         .mknod          = hugetlbfs_mknod,
734         .rename         = simple_rename,
735         .setattr        = hugetlbfs_setattr,
736 };
737
738 static const struct inode_operations hugetlbfs_inode_operations = {
739         .setattr        = hugetlbfs_setattr,
740 };
741
742 static const struct super_operations hugetlbfs_ops = {
743         .alloc_inode    = hugetlbfs_alloc_inode,
744         .destroy_inode  = hugetlbfs_destroy_inode,
745         .statfs         = hugetlbfs_statfs,
746         .delete_inode   = hugetlbfs_delete_inode,
747         .drop_inode     = hugetlbfs_drop_inode,
748         .put_super      = hugetlbfs_put_super,
749         .show_options   = generic_show_options,
750 };
751
752 static int
753 hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
754 {
755         char *p, *rest;
756         substring_t args[MAX_OPT_ARGS];
757         int option;
758         unsigned long long size = 0;
759         enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = NO_SIZE;
760
761         if (!options)
762                 return 0;
763
764         while ((p = strsep(&options, ",")) != NULL) {
765                 int token;
766                 if (!*p)
767                         continue;
768
769                 token = match_token(p, tokens, args);
770                 switch (token) {
771                 case Opt_uid:
772                         if (match_int(&args[0], &option))
773                                 goto bad_val;
774                         pconfig->uid = option;
775                         break;
776
777                 case Opt_gid:
778                         if (match_int(&args[0], &option))
779                                 goto bad_val;
780                         pconfig->gid = option;
781                         break;
782
783                 case Opt_mode:
784                         if (match_octal(&args[0], &option))
785                                 goto bad_val;
786                         pconfig->mode = option & 01777U;
787                         break;
788
789                 case Opt_size: {
790                         /* memparse() will accept a K/M/G without a digit */
791                         if (!isdigit(*args[0].from))
792                                 goto bad_val;
793                         size = memparse(args[0].from, &rest);
794                         setsize = SIZE_STD;
795                         if (*rest == '%')
796                                 setsize = SIZE_PERCENT;
797                         break;
798                 }
799
800                 case Opt_nr_inodes:
801                         /* memparse() will accept a K/M/G without a digit */
802                         if (!isdigit(*args[0].from))
803                                 goto bad_val;
804                         pconfig->nr_inodes = memparse(args[0].from, &rest);
805                         break;
806
807                 case Opt_pagesize: {
808                         unsigned long ps;
809                         ps = memparse(args[0].from, &rest);
810                         pconfig->hstate = size_to_hstate(ps);
811                         if (!pconfig->hstate) {
812                                 printk(KERN_ERR
813                                 "hugetlbfs: Unsupported page size %lu MB\n",
814                                         ps >> 20);
815                                 return -EINVAL;
816                         }
817                         break;
818                 }
819
820                 default:
821                         printk(KERN_ERR "hugetlbfs: Bad mount option: \"%s\"\n",
822                                  p);
823                         return -EINVAL;
824                         break;
825                 }
826         }
827
828         /* Do size after hstate is set up */
829         if (setsize > NO_SIZE) {
830                 struct hstate *h = pconfig->hstate;
831                 if (setsize == SIZE_PERCENT) {
832                         size <<= huge_page_shift(h);
833                         size *= h->max_huge_pages;
834                         do_div(size, 100);
835                 }
836                 pconfig->nr_blocks = (size >> huge_page_shift(h));
837         }
838
839         return 0;
840
841 bad_val:
842         printk(KERN_ERR "hugetlbfs: Bad value '%s' for mount option '%s'\n",
843                args[0].from, p);
844         return -EINVAL;
845 }
846
847 static int
848 hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
849 {
850         struct inode * inode;
851         struct dentry * root;
852         int ret;
853         struct hugetlbfs_config config;
854         struct hugetlbfs_sb_info *sbinfo;
855
856         save_mount_options(sb, data);
857
858         config.nr_blocks = -1; /* No limit on size by default */
859         config.nr_inodes = -1; /* No limit on number of inodes by default */
860         config.uid = current_fsuid();
861         config.gid = current_fsgid();
862         config.mode = 0755;
863         config.hstate = &default_hstate;
864         ret = hugetlbfs_parse_options(data, &config);
865         if (ret)
866                 return ret;
867
868         sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL);
869         if (!sbinfo)
870                 return -ENOMEM;
871         sb->s_fs_info = sbinfo;
872         sbinfo->hstate = config.hstate;
873         spin_lock_init(&sbinfo->stat_lock);
874         sbinfo->max_blocks = config.nr_blocks;
875         sbinfo->free_blocks = config.nr_blocks;
876         sbinfo->max_inodes = config.nr_inodes;
877         sbinfo->free_inodes = config.nr_inodes;
878         sb->s_maxbytes = MAX_LFS_FILESIZE;
879         sb->s_blocksize = huge_page_size(config.hstate);
880         sb->s_blocksize_bits = huge_page_shift(config.hstate);
881         sb->s_magic = HUGETLBFS_MAGIC;
882         sb->s_op = &hugetlbfs_ops;
883         sb->s_time_gran = 1;
884         inode = hugetlbfs_get_inode(sb, config.uid, config.gid,
885                                         S_IFDIR | config.mode, 0);
886         if (!inode)
887                 goto out_free;
888
889         root = d_alloc_root(inode);
890         if (!root) {
891                 iput(inode);
892                 goto out_free;
893         }
894         sb->s_root = root;
895         return 0;
896 out_free:
897         kfree(sbinfo);
898         return -ENOMEM;
899 }
900
901 int hugetlb_get_quota(struct address_space *mapping, long delta)
902 {
903         int ret = 0;
904         struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb);
905
906         if (sbinfo->free_blocks > -1) {
907                 spin_lock(&sbinfo->stat_lock);
908                 if (sbinfo->free_blocks - delta >= 0)
909                         sbinfo->free_blocks -= delta;
910                 else
911                         ret = -ENOMEM;
912                 spin_unlock(&sbinfo->stat_lock);
913         }
914
915         return ret;
916 }
917
918 void hugetlb_put_quota(struct address_space *mapping, long delta)
919 {
920         struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb);
921
922         if (sbinfo->free_blocks > -1) {
923                 spin_lock(&sbinfo->stat_lock);
924                 sbinfo->free_blocks += delta;
925                 spin_unlock(&sbinfo->stat_lock);
926         }
927 }
928
929 static int hugetlbfs_get_sb(struct file_system_type *fs_type,
930         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
931 {
932         return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super, mnt);
933 }
934
935 static struct file_system_type hugetlbfs_fs_type = {
936         .name           = "hugetlbfs",
937         .get_sb         = hugetlbfs_get_sb,
938         .kill_sb        = kill_litter_super,
939 };
940
941 static struct vfsmount *hugetlbfs_vfsmount;
942
943 static int can_do_hugetlb_shm(void)
944 {
945         return capable(CAP_IPC_LOCK) || in_group_p(sysctl_hugetlb_shm_group);
946 }
947
948 struct file *hugetlb_file_setup(const char *name, size_t size, int acctflag)
949 {
950         int error = -ENOMEM;
951         int unlock_shm = 0;
952         struct file *file;
953         struct inode *inode;
954         struct dentry *dentry, *root;
955         struct qstr quick_string;
956         struct user_struct *user = current_user();
957
958         if (!hugetlbfs_vfsmount)
959                 return ERR_PTR(-ENOENT);
960
961         if (!can_do_hugetlb_shm()) {
962                 if (user_shm_lock(size, user)) {
963                         unlock_shm = 1;
964                         WARN_ONCE(1,
965                           "Using mlock ulimits for SHM_HUGETLB deprecated\n");
966                 } else
967                         return ERR_PTR(-EPERM);
968         }
969
970         root = hugetlbfs_vfsmount->mnt_root;
971         quick_string.name = name;
972         quick_string.len = strlen(quick_string.name);
973         quick_string.hash = 0;
974         dentry = d_alloc(root, &quick_string);
975         if (!dentry)
976                 goto out_shm_unlock;
977
978         error = -ENOSPC;
979         inode = hugetlbfs_get_inode(root->d_sb, current_fsuid(),
980                                 current_fsgid(), S_IFREG | S_IRWXUGO, 0);
981         if (!inode)
982                 goto out_dentry;
983
984         error = -ENOMEM;
985         if (hugetlb_reserve_pages(inode, 0,
986                         size >> huge_page_shift(hstate_inode(inode)), NULL,
987                         acctflag))
988                 goto out_inode;
989
990         d_instantiate(dentry, inode);
991         inode->i_size = size;
992         inode->i_nlink = 0;
993
994         error = -ENFILE;
995         file = alloc_file(hugetlbfs_vfsmount, dentry,
996                         FMODE_WRITE | FMODE_READ,
997                         &hugetlbfs_file_operations);
998         if (!file)
999                 goto out_dentry; /* inode is already attached */
1000
1001         return file;
1002
1003 out_inode:
1004         iput(inode);
1005 out_dentry:
1006         dput(dentry);
1007 out_shm_unlock:
1008         if (unlock_shm)
1009                 user_shm_unlock(size, user);
1010         return ERR_PTR(error);
1011 }
1012
1013 static int __init init_hugetlbfs_fs(void)
1014 {
1015         int error;
1016         struct vfsmount *vfsmount;
1017
1018         error = bdi_init(&hugetlbfs_backing_dev_info);
1019         if (error)
1020                 return error;
1021
1022         hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
1023                                         sizeof(struct hugetlbfs_inode_info),
1024                                         0, 0, init_once);
1025         if (hugetlbfs_inode_cachep == NULL)
1026                 goto out2;
1027
1028         error = register_filesystem(&hugetlbfs_fs_type);
1029         if (error)
1030                 goto out;
1031
1032         vfsmount = kern_mount(&hugetlbfs_fs_type);
1033
1034         if (!IS_ERR(vfsmount)) {
1035                 hugetlbfs_vfsmount = vfsmount;
1036                 return 0;
1037         }
1038
1039         error = PTR_ERR(vfsmount);
1040
1041  out:
1042         if (error)
1043                 kmem_cache_destroy(hugetlbfs_inode_cachep);
1044  out2:
1045         bdi_destroy(&hugetlbfs_backing_dev_info);
1046         return error;
1047 }
1048
1049 static void __exit exit_hugetlbfs_fs(void)
1050 {
1051         kmem_cache_destroy(hugetlbfs_inode_cachep);
1052         unregister_filesystem(&hugetlbfs_fs_type);
1053         bdi_destroy(&hugetlbfs_backing_dev_info);
1054 }
1055
1056 module_init(init_hugetlbfs_fs)
1057 module_exit(exit_hugetlbfs_fs)
1058
1059 MODULE_LICENSE("GPL");