Merge branch 'next' of git://git.monstr.eu/linux-2.6-microblaze
[linux-3.10.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 #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 struct hugetlbfs_config {
45         uid_t   uid;
46         gid_t   gid;
47         umode_t mode;
48         long    nr_blocks;
49         long    nr_inodes;
50         struct hstate *hstate;
51 };
52
53 struct hugetlbfs_inode_info {
54         struct shared_policy policy;
55         struct inode vfs_inode;
56 };
57
58 static inline struct hugetlbfs_inode_info *HUGETLBFS_I(struct inode *inode)
59 {
60         return container_of(inode, struct hugetlbfs_inode_info, vfs_inode);
61 }
62
63 static struct backing_dev_info hugetlbfs_backing_dev_info = {
64         .name           = "hugetlbfs",
65         .ra_pages       = 0,    /* No readahead */
66         .capabilities   = BDI_CAP_NO_ACCT_AND_WRITEBACK,
67 };
68
69 int sysctl_hugetlb_shm_group;
70
71 enum {
72         Opt_size, Opt_nr_inodes,
73         Opt_mode, Opt_uid, Opt_gid,
74         Opt_pagesize,
75         Opt_err,
76 };
77
78 static const match_table_t tokens = {
79         {Opt_size,      "size=%s"},
80         {Opt_nr_inodes, "nr_inodes=%s"},
81         {Opt_mode,      "mode=%o"},
82         {Opt_uid,       "uid=%u"},
83         {Opt_gid,       "gid=%u"},
84         {Opt_pagesize,  "pagesize=%s"},
85         {Opt_err,       NULL},
86 };
87
88 static void huge_pagevec_release(struct pagevec *pvec)
89 {
90         int i;
91
92         for (i = 0; i < pagevec_count(pvec); ++i)
93                 put_page(pvec->pages[i]);
94
95         pagevec_reinit(pvec);
96 }
97
98 static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
99 {
100         struct inode *inode = file->f_path.dentry->d_inode;
101         loff_t len, vma_len;
102         int ret;
103         struct hstate *h = hstate_file(file);
104
105         /*
106          * vma address alignment (but not the pgoff alignment) has
107          * already been checked by prepare_hugepage_range.  If you add
108          * any error returns here, do so after setting VM_HUGETLB, so
109          * is_vm_hugetlb_page tests below unmap_region go the right
110          * way when do_mmap_pgoff unwinds (may be important on powerpc
111          * and ia64).
112          */
113         vma->vm_flags |= VM_HUGETLB | VM_RESERVED;
114         vma->vm_ops = &hugetlb_vm_ops;
115
116         if (vma->vm_pgoff & (~huge_page_mask(h) >> PAGE_SHIFT))
117                 return -EINVAL;
118
119         vma_len = (loff_t)(vma->vm_end - vma->vm_start);
120
121         mutex_lock(&inode->i_mutex);
122         file_accessed(file);
123
124         ret = -ENOMEM;
125         len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
126
127         if (hugetlb_reserve_pages(inode,
128                                 vma->vm_pgoff >> huge_page_order(h),
129                                 len >> huge_page_shift(h), vma,
130                                 vma->vm_flags))
131                 goto out;
132
133         ret = 0;
134         hugetlb_prefault_arch_hook(vma->vm_mm);
135         if (vma->vm_flags & VM_WRITE && inode->i_size < len)
136                 inode->i_size = len;
137 out:
138         mutex_unlock(&inode->i_mutex);
139
140         return ret;
141 }
142
143 /*
144  * Called under down_write(mmap_sem).
145  */
146
147 #ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
148 static unsigned long
149 hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
150                 unsigned long len, unsigned long pgoff, unsigned long flags)
151 {
152         struct mm_struct *mm = current->mm;
153         struct vm_area_struct *vma;
154         unsigned long start_addr;
155         struct hstate *h = hstate_file(file);
156
157         if (len & ~huge_page_mask(h))
158                 return -EINVAL;
159         if (len > TASK_SIZE)
160                 return -ENOMEM;
161
162         if (flags & MAP_FIXED) {
163                 if (prepare_hugepage_range(file, addr, len))
164                         return -EINVAL;
165                 return addr;
166         }
167
168         if (addr) {
169                 addr = ALIGN(addr, huge_page_size(h));
170                 vma = find_vma(mm, addr);
171                 if (TASK_SIZE - len >= addr &&
172                     (!vma || addr + len <= vma->vm_start))
173                         return addr;
174         }
175
176         if (len > mm->cached_hole_size)
177                 start_addr = mm->free_area_cache;
178         else {
179                 start_addr = TASK_UNMAPPED_BASE;
180                 mm->cached_hole_size = 0;
181         }
182
183 full_search:
184         addr = ALIGN(start_addr, huge_page_size(h));
185
186         for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
187                 /* At this point:  (!vma || addr < vma->vm_end). */
188                 if (TASK_SIZE - len < addr) {
189                         /*
190                          * Start a new search - just in case we missed
191                          * some holes.
192                          */
193                         if (start_addr != TASK_UNMAPPED_BASE) {
194                                 start_addr = TASK_UNMAPPED_BASE;
195                                 mm->cached_hole_size = 0;
196                                 goto full_search;
197                         }
198                         return -ENOMEM;
199                 }
200
201                 if (!vma || addr + len <= vma->vm_start) {
202                         mm->free_area_cache = addr + len;
203                         return addr;
204                 }
205                 if (addr + mm->cached_hole_size < vma->vm_start)
206                         mm->cached_hole_size = vma->vm_start - addr;
207                 addr = ALIGN(vma->vm_end, huge_page_size(h));
208         }
209 }
210 #endif
211
212 static int
213 hugetlbfs_read_actor(struct page *page, unsigned long offset,
214                         char __user *buf, unsigned long count,
215                         unsigned long size)
216 {
217         char *kaddr;
218         unsigned long left, copied = 0;
219         int i, chunksize;
220
221         if (size > count)
222                 size = count;
223
224         /* Find which 4k chunk and offset with in that chunk */
225         i = offset >> PAGE_CACHE_SHIFT;
226         offset = offset & ~PAGE_CACHE_MASK;
227
228         while (size) {
229                 chunksize = PAGE_CACHE_SIZE;
230                 if (offset)
231                         chunksize -= offset;
232                 if (chunksize > size)
233                         chunksize = size;
234                 kaddr = kmap(&page[i]);
235                 left = __copy_to_user(buf, kaddr + offset, chunksize);
236                 kunmap(&page[i]);
237                 if (left) {
238                         copied += (chunksize - left);
239                         break;
240                 }
241                 offset = 0;
242                 size -= chunksize;
243                 buf += chunksize;
244                 copied += chunksize;
245                 i++;
246         }
247         return copied ? copied : -EFAULT;
248 }
249
250 /*
251  * Support for read() - Find the page attached to f_mapping and copy out the
252  * data. Its *very* similar to do_generic_mapping_read(), we can't use that
253  * since it has PAGE_CACHE_SIZE assumptions.
254  */
255 static ssize_t hugetlbfs_read(struct file *filp, char __user *buf,
256                               size_t len, loff_t *ppos)
257 {
258         struct hstate *h = hstate_file(filp);
259         struct address_space *mapping = filp->f_mapping;
260         struct inode *inode = mapping->host;
261         unsigned long index = *ppos >> huge_page_shift(h);
262         unsigned long offset = *ppos & ~huge_page_mask(h);
263         unsigned long end_index;
264         loff_t isize;
265         ssize_t retval = 0;
266
267         /* validate length */
268         if (len == 0)
269                 goto out;
270
271         for (;;) {
272                 struct page *page;
273                 unsigned long nr, ret;
274                 int ra;
275
276                 /* nr is the maximum number of bytes to copy from this page */
277                 nr = huge_page_size(h);
278                 isize = i_size_read(inode);
279                 if (!isize)
280                         goto out;
281                 end_index = (isize - 1) >> huge_page_shift(h);
282                 if (index >= end_index) {
283                         if (index > end_index)
284                                 goto out;
285                         nr = ((isize - 1) & ~huge_page_mask(h)) + 1;
286                         if (nr <= offset)
287                                 goto out;
288                 }
289                 nr = nr - offset;
290
291                 /* Find the page */
292                 page = find_lock_page(mapping, index);
293                 if (unlikely(page == NULL)) {
294                         /*
295                          * We have a HOLE, zero out the user-buffer for the
296                          * length of the hole or request.
297                          */
298                         ret = len < nr ? len : nr;
299                         if (clear_user(buf, ret))
300                                 ra = -EFAULT;
301                         else
302                                 ra = 0;
303                 } else {
304                         unlock_page(page);
305
306                         /*
307                          * We have the page, copy it to user space buffer.
308                          */
309                         ra = hugetlbfs_read_actor(page, offset, buf, len, nr);
310                         ret = ra;
311                         page_cache_release(page);
312                 }
313                 if (ra < 0) {
314                         if (retval == 0)
315                                 retval = ra;
316                         goto out;
317                 }
318
319                 offset += ret;
320                 retval += ret;
321                 len -= ret;
322                 index += offset >> huge_page_shift(h);
323                 offset &= ~huge_page_mask(h);
324
325                 /* short read or no more work */
326                 if ((ret != nr) || (len == 0))
327                         break;
328         }
329 out:
330         *ppos = ((loff_t)index << huge_page_shift(h)) + offset;
331         return retval;
332 }
333
334 static int hugetlbfs_write_begin(struct file *file,
335                         struct address_space *mapping,
336                         loff_t pos, unsigned len, unsigned flags,
337                         struct page **pagep, void **fsdata)
338 {
339         return -EINVAL;
340 }
341
342 static int hugetlbfs_write_end(struct file *file, struct address_space *mapping,
343                         loff_t pos, unsigned len, unsigned copied,
344                         struct page *page, void *fsdata)
345 {
346         BUG();
347         return -EINVAL;
348 }
349
350 static void truncate_huge_page(struct page *page)
351 {
352         cancel_dirty_page(page, /* No IO accounting for huge pages? */0);
353         ClearPageUptodate(page);
354         delete_from_page_cache(page);
355 }
356
357 static void truncate_hugepages(struct inode *inode, loff_t lstart)
358 {
359         struct hstate *h = hstate_inode(inode);
360         struct address_space *mapping = &inode->i_data;
361         const pgoff_t start = lstart >> huge_page_shift(h);
362         struct pagevec pvec;
363         pgoff_t next;
364         int i, freed = 0;
365
366         pagevec_init(&pvec, 0);
367         next = start;
368         while (1) {
369                 if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
370                         if (next == start)
371                                 break;
372                         next = start;
373                         continue;
374                 }
375
376                 for (i = 0; i < pagevec_count(&pvec); ++i) {
377                         struct page *page = pvec.pages[i];
378
379                         lock_page(page);
380                         if (page->index > next)
381                                 next = page->index;
382                         ++next;
383                         truncate_huge_page(page);
384                         unlock_page(page);
385                         freed++;
386                 }
387                 huge_pagevec_release(&pvec);
388         }
389         BUG_ON(!lstart && mapping->nrpages);
390         hugetlb_unreserve_pages(inode, start, freed);
391 }
392
393 static void hugetlbfs_evict_inode(struct inode *inode)
394 {
395         truncate_hugepages(inode, 0);
396         end_writeback(inode);
397 }
398
399 static inline void
400 hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff)
401 {
402         struct vm_area_struct *vma;
403         struct prio_tree_iter iter;
404
405         vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) {
406                 unsigned long v_offset;
407
408                 /*
409                  * Can the expression below overflow on 32-bit arches?
410                  * No, because the prio_tree returns us only those vmas
411                  * which overlap the truncated area starting at pgoff,
412                  * and no vma on a 32-bit arch can span beyond the 4GB.
413                  */
414                 if (vma->vm_pgoff < pgoff)
415                         v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT;
416                 else
417                         v_offset = 0;
418
419                 __unmap_hugepage_range(vma,
420                                 vma->vm_start + v_offset, vma->vm_end, NULL);
421         }
422 }
423
424 static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
425 {
426         pgoff_t pgoff;
427         struct address_space *mapping = inode->i_mapping;
428         struct hstate *h = hstate_inode(inode);
429
430         BUG_ON(offset & ~huge_page_mask(h));
431         pgoff = offset >> PAGE_SHIFT;
432
433         i_size_write(inode, offset);
434         mutex_lock(&mapping->i_mmap_mutex);
435         if (!prio_tree_empty(&mapping->i_mmap))
436                 hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
437         mutex_unlock(&mapping->i_mmap_mutex);
438         truncate_hugepages(inode, offset);
439         return 0;
440 }
441
442 static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
443 {
444         struct inode *inode = dentry->d_inode;
445         struct hstate *h = hstate_inode(inode);
446         int error;
447         unsigned int ia_valid = attr->ia_valid;
448
449         BUG_ON(!inode);
450
451         error = inode_change_ok(inode, attr);
452         if (error)
453                 return error;
454
455         if (ia_valid & ATTR_SIZE) {
456                 error = -EINVAL;
457                 if (attr->ia_size & ~huge_page_mask(h))
458                         return -EINVAL;
459                 error = hugetlb_vmtruncate(inode, attr->ia_size);
460                 if (error)
461                         return error;
462         }
463
464         setattr_copy(inode, attr);
465         mark_inode_dirty(inode);
466         return 0;
467 }
468
469 static struct inode *hugetlbfs_get_root(struct super_block *sb,
470                                         struct hugetlbfs_config *config)
471 {
472         struct inode *inode;
473
474         inode = new_inode(sb);
475         if (inode) {
476                 struct hugetlbfs_inode_info *info;
477                 inode->i_ino = get_next_ino();
478                 inode->i_mode = S_IFDIR | config->mode;
479                 inode->i_uid = config->uid;
480                 inode->i_gid = config->gid;
481                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
482                 info = HUGETLBFS_I(inode);
483                 mpol_shared_policy_init(&info->policy, NULL);
484                 inode->i_op = &hugetlbfs_dir_inode_operations;
485                 inode->i_fop = &simple_dir_operations;
486                 /* directory inodes start off with i_nlink == 2 (for "." entry) */
487                 inc_nlink(inode);
488                 lockdep_annotate_inode_mutex_key(inode);
489         }
490         return inode;
491 }
492
493 static struct inode *hugetlbfs_get_inode(struct super_block *sb,
494                                         struct inode *dir,
495                                         umode_t mode, dev_t dev)
496 {
497         struct inode *inode;
498
499         inode = new_inode(sb);
500         if (inode) {
501                 struct hugetlbfs_inode_info *info;
502                 inode->i_ino = get_next_ino();
503                 inode_init_owner(inode, dir, mode);
504                 inode->i_mapping->a_ops = &hugetlbfs_aops;
505                 inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info;
506                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
507                 INIT_LIST_HEAD(&inode->i_mapping->private_list);
508                 info = HUGETLBFS_I(inode);
509                 /*
510                  * The policy is initialized here even if we are creating a
511                  * private inode because initialization simply creates an
512                  * an empty rb tree and calls spin_lock_init(), later when we
513                  * call mpol_free_shared_policy() it will just return because
514                  * the rb tree will still be empty.
515                  */
516                 mpol_shared_policy_init(&info->policy, NULL);
517                 switch (mode & S_IFMT) {
518                 default:
519                         init_special_inode(inode, mode, dev);
520                         break;
521                 case S_IFREG:
522                         inode->i_op = &hugetlbfs_inode_operations;
523                         inode->i_fop = &hugetlbfs_file_operations;
524                         break;
525                 case S_IFDIR:
526                         inode->i_op = &hugetlbfs_dir_inode_operations;
527                         inode->i_fop = &simple_dir_operations;
528
529                         /* directory inodes start off with i_nlink == 2 (for "." entry) */
530                         inc_nlink(inode);
531                         break;
532                 case S_IFLNK:
533                         inode->i_op = &page_symlink_inode_operations;
534                         break;
535                 }
536                 lockdep_annotate_inode_mutex_key(inode);
537         }
538         return inode;
539 }
540
541 /*
542  * File creation. Allocate an inode, and we're done..
543  */
544 static int hugetlbfs_mknod(struct inode *dir,
545                         struct dentry *dentry, umode_t mode, dev_t dev)
546 {
547         struct inode *inode;
548         int error = -ENOSPC;
549
550         inode = hugetlbfs_get_inode(dir->i_sb, dir, mode, dev);
551         if (inode) {
552                 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
553                 d_instantiate(dentry, inode);
554                 dget(dentry);   /* Extra count - pin the dentry in core */
555                 error = 0;
556         }
557         return error;
558 }
559
560 static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
561 {
562         int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0);
563         if (!retval)
564                 inc_nlink(dir);
565         return retval;
566 }
567
568 static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, struct nameidata *nd)
569 {
570         return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0);
571 }
572
573 static int hugetlbfs_symlink(struct inode *dir,
574                         struct dentry *dentry, const char *symname)
575 {
576         struct inode *inode;
577         int error = -ENOSPC;
578
579         inode = hugetlbfs_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0);
580         if (inode) {
581                 int l = strlen(symname)+1;
582                 error = page_symlink(inode, symname, l);
583                 if (!error) {
584                         d_instantiate(dentry, inode);
585                         dget(dentry);
586                 } else
587                         iput(inode);
588         }
589         dir->i_ctime = dir->i_mtime = CURRENT_TIME;
590
591         return error;
592 }
593
594 /*
595  * mark the head page dirty
596  */
597 static int hugetlbfs_set_page_dirty(struct page *page)
598 {
599         struct page *head = compound_head(page);
600
601         SetPageDirty(head);
602         return 0;
603 }
604
605 static int hugetlbfs_migrate_page(struct address_space *mapping,
606                                 struct page *newpage, struct page *page,
607                                 enum migrate_mode mode)
608 {
609         int rc;
610
611         rc = migrate_huge_page_move_mapping(mapping, newpage, page);
612         if (rc)
613                 return rc;
614         migrate_page_copy(newpage, page);
615
616         return 0;
617 }
618
619 static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
620 {
621         struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
622         struct hstate *h = hstate_inode(dentry->d_inode);
623
624         buf->f_type = HUGETLBFS_MAGIC;
625         buf->f_bsize = huge_page_size(h);
626         if (sbinfo) {
627                 spin_lock(&sbinfo->stat_lock);
628                 /* If no limits set, just report 0 for max/free/used
629                  * blocks, like simple_statfs() */
630                 if (sbinfo->spool) {
631                         long free_pages;
632
633                         spin_lock(&sbinfo->spool->lock);
634                         buf->f_blocks = sbinfo->spool->max_hpages;
635                         free_pages = sbinfo->spool->max_hpages
636                                 - sbinfo->spool->used_hpages;
637                         buf->f_bavail = buf->f_bfree = free_pages;
638                         spin_unlock(&sbinfo->spool->lock);
639                         buf->f_files = sbinfo->max_inodes;
640                         buf->f_ffree = sbinfo->free_inodes;
641                 }
642                 spin_unlock(&sbinfo->stat_lock);
643         }
644         buf->f_namelen = NAME_MAX;
645         return 0;
646 }
647
648 static void hugetlbfs_put_super(struct super_block *sb)
649 {
650         struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb);
651
652         if (sbi) {
653                 sb->s_fs_info = NULL;
654
655                 if (sbi->spool)
656                         hugepage_put_subpool(sbi->spool);
657
658                 kfree(sbi);
659         }
660 }
661
662 static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo)
663 {
664         if (sbinfo->free_inodes >= 0) {
665                 spin_lock(&sbinfo->stat_lock);
666                 if (unlikely(!sbinfo->free_inodes)) {
667                         spin_unlock(&sbinfo->stat_lock);
668                         return 0;
669                 }
670                 sbinfo->free_inodes--;
671                 spin_unlock(&sbinfo->stat_lock);
672         }
673
674         return 1;
675 }
676
677 static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
678 {
679         if (sbinfo->free_inodes >= 0) {
680                 spin_lock(&sbinfo->stat_lock);
681                 sbinfo->free_inodes++;
682                 spin_unlock(&sbinfo->stat_lock);
683         }
684 }
685
686
687 static struct kmem_cache *hugetlbfs_inode_cachep;
688
689 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
690 {
691         struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
692         struct hugetlbfs_inode_info *p;
693
694         if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
695                 return NULL;
696         p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL);
697         if (unlikely(!p)) {
698                 hugetlbfs_inc_free_inodes(sbinfo);
699                 return NULL;
700         }
701         return &p->vfs_inode;
702 }
703
704 static void hugetlbfs_i_callback(struct rcu_head *head)
705 {
706         struct inode *inode = container_of(head, struct inode, i_rcu);
707         kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
708 }
709
710 static void hugetlbfs_destroy_inode(struct inode *inode)
711 {
712         hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
713         mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
714         call_rcu(&inode->i_rcu, hugetlbfs_i_callback);
715 }
716
717 static const struct address_space_operations hugetlbfs_aops = {
718         .write_begin    = hugetlbfs_write_begin,
719         .write_end      = hugetlbfs_write_end,
720         .set_page_dirty = hugetlbfs_set_page_dirty,
721         .migratepage    = hugetlbfs_migrate_page,
722 };
723
724
725 static void init_once(void *foo)
726 {
727         struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
728
729         inode_init_once(&ei->vfs_inode);
730 }
731
732 const struct file_operations hugetlbfs_file_operations = {
733         .read                   = hugetlbfs_read,
734         .mmap                   = hugetlbfs_file_mmap,
735         .fsync                  = noop_fsync,
736         .get_unmapped_area      = hugetlb_get_unmapped_area,
737         .llseek         = default_llseek,
738 };
739
740 static const struct inode_operations hugetlbfs_dir_inode_operations = {
741         .create         = hugetlbfs_create,
742         .lookup         = simple_lookup,
743         .link           = simple_link,
744         .unlink         = simple_unlink,
745         .symlink        = hugetlbfs_symlink,
746         .mkdir          = hugetlbfs_mkdir,
747         .rmdir          = simple_rmdir,
748         .mknod          = hugetlbfs_mknod,
749         .rename         = simple_rename,
750         .setattr        = hugetlbfs_setattr,
751 };
752
753 static const struct inode_operations hugetlbfs_inode_operations = {
754         .setattr        = hugetlbfs_setattr,
755 };
756
757 static const struct super_operations hugetlbfs_ops = {
758         .alloc_inode    = hugetlbfs_alloc_inode,
759         .destroy_inode  = hugetlbfs_destroy_inode,
760         .evict_inode    = hugetlbfs_evict_inode,
761         .statfs         = hugetlbfs_statfs,
762         .put_super      = hugetlbfs_put_super,
763         .show_options   = generic_show_options,
764 };
765
766 static int
767 hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
768 {
769         char *p, *rest;
770         substring_t args[MAX_OPT_ARGS];
771         int option;
772         unsigned long long size = 0;
773         enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = NO_SIZE;
774
775         if (!options)
776                 return 0;
777
778         while ((p = strsep(&options, ",")) != NULL) {
779                 int token;
780                 if (!*p)
781                         continue;
782
783                 token = match_token(p, tokens, args);
784                 switch (token) {
785                 case Opt_uid:
786                         if (match_int(&args[0], &option))
787                                 goto bad_val;
788                         pconfig->uid = option;
789                         break;
790
791                 case Opt_gid:
792                         if (match_int(&args[0], &option))
793                                 goto bad_val;
794                         pconfig->gid = option;
795                         break;
796
797                 case Opt_mode:
798                         if (match_octal(&args[0], &option))
799                                 goto bad_val;
800                         pconfig->mode = option & 01777U;
801                         break;
802
803                 case Opt_size: {
804                         /* memparse() will accept a K/M/G without a digit */
805                         if (!isdigit(*args[0].from))
806                                 goto bad_val;
807                         size = memparse(args[0].from, &rest);
808                         setsize = SIZE_STD;
809                         if (*rest == '%')
810                                 setsize = SIZE_PERCENT;
811                         break;
812                 }
813
814                 case Opt_nr_inodes:
815                         /* memparse() will accept a K/M/G without a digit */
816                         if (!isdigit(*args[0].from))
817                                 goto bad_val;
818                         pconfig->nr_inodes = memparse(args[0].from, &rest);
819                         break;
820
821                 case Opt_pagesize: {
822                         unsigned long ps;
823                         ps = memparse(args[0].from, &rest);
824                         pconfig->hstate = size_to_hstate(ps);
825                         if (!pconfig->hstate) {
826                                 printk(KERN_ERR
827                                 "hugetlbfs: Unsupported page size %lu MB\n",
828                                         ps >> 20);
829                                 return -EINVAL;
830                         }
831                         break;
832                 }
833
834                 default:
835                         printk(KERN_ERR "hugetlbfs: Bad mount option: \"%s\"\n",
836                                  p);
837                         return -EINVAL;
838                         break;
839                 }
840         }
841
842         /* Do size after hstate is set up */
843         if (setsize > NO_SIZE) {
844                 struct hstate *h = pconfig->hstate;
845                 if (setsize == SIZE_PERCENT) {
846                         size <<= huge_page_shift(h);
847                         size *= h->max_huge_pages;
848                         do_div(size, 100);
849                 }
850                 pconfig->nr_blocks = (size >> huge_page_shift(h));
851         }
852
853         return 0;
854
855 bad_val:
856         printk(KERN_ERR "hugetlbfs: Bad value '%s' for mount option '%s'\n",
857                args[0].from, p);
858         return -EINVAL;
859 }
860
861 static int
862 hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
863 {
864         int ret;
865         struct hugetlbfs_config config;
866         struct hugetlbfs_sb_info *sbinfo;
867
868         save_mount_options(sb, data);
869
870         config.nr_blocks = -1; /* No limit on size by default */
871         config.nr_inodes = -1; /* No limit on number of inodes by default */
872         config.uid = current_fsuid();
873         config.gid = current_fsgid();
874         config.mode = 0755;
875         config.hstate = &default_hstate;
876         ret = hugetlbfs_parse_options(data, &config);
877         if (ret)
878                 return ret;
879
880         sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL);
881         if (!sbinfo)
882                 return -ENOMEM;
883         sb->s_fs_info = sbinfo;
884         sbinfo->hstate = config.hstate;
885         spin_lock_init(&sbinfo->stat_lock);
886         sbinfo->max_inodes = config.nr_inodes;
887         sbinfo->free_inodes = config.nr_inodes;
888         sbinfo->spool = NULL;
889         if (config.nr_blocks != -1) {
890                 sbinfo->spool = hugepage_new_subpool(config.nr_blocks);
891                 if (!sbinfo->spool)
892                         goto out_free;
893         }
894         sb->s_maxbytes = MAX_LFS_FILESIZE;
895         sb->s_blocksize = huge_page_size(config.hstate);
896         sb->s_blocksize_bits = huge_page_shift(config.hstate);
897         sb->s_magic = HUGETLBFS_MAGIC;
898         sb->s_op = &hugetlbfs_ops;
899         sb->s_time_gran = 1;
900         sb->s_root = d_make_root(hugetlbfs_get_root(sb, &config));
901         if (!sb->s_root)
902                 goto out_free;
903         return 0;
904 out_free:
905         if (sbinfo->spool)
906                 kfree(sbinfo->spool);
907         kfree(sbinfo);
908         return -ENOMEM;
909 }
910
911 static struct dentry *hugetlbfs_mount(struct file_system_type *fs_type,
912         int flags, const char *dev_name, void *data)
913 {
914         return mount_nodev(fs_type, flags, data, hugetlbfs_fill_super);
915 }
916
917 static struct file_system_type hugetlbfs_fs_type = {
918         .name           = "hugetlbfs",
919         .mount          = hugetlbfs_mount,
920         .kill_sb        = kill_litter_super,
921 };
922
923 static struct vfsmount *hugetlbfs_vfsmount;
924
925 static int can_do_hugetlb_shm(void)
926 {
927         return capable(CAP_IPC_LOCK) || in_group_p(sysctl_hugetlb_shm_group);
928 }
929
930 struct file *hugetlb_file_setup(const char *name, unsigned long addr,
931                                 size_t size, vm_flags_t acctflag,
932                                 struct user_struct **user, int creat_flags)
933 {
934         int error = -ENOMEM;
935         struct file *file;
936         struct inode *inode;
937         struct path path;
938         struct dentry *root;
939         struct qstr quick_string;
940         struct hstate *hstate;
941         unsigned long num_pages;
942
943         *user = NULL;
944         if (!hugetlbfs_vfsmount)
945                 return ERR_PTR(-ENOENT);
946
947         if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) {
948                 *user = current_user();
949                 if (user_shm_lock(size, *user)) {
950                         task_lock(current);
951                         printk_once(KERN_WARNING
952                                 "%s (%d): Using mlock ulimits for SHM_HUGETLB is deprecated\n",
953                                 current->comm, current->pid);
954                         task_unlock(current);
955                 } else {
956                         *user = NULL;
957                         return ERR_PTR(-EPERM);
958                 }
959         }
960
961         root = hugetlbfs_vfsmount->mnt_root;
962         quick_string.name = name;
963         quick_string.len = strlen(quick_string.name);
964         quick_string.hash = 0;
965         path.dentry = d_alloc(root, &quick_string);
966         if (!path.dentry)
967                 goto out_shm_unlock;
968
969         path.mnt = mntget(hugetlbfs_vfsmount);
970         error = -ENOSPC;
971         inode = hugetlbfs_get_inode(root->d_sb, NULL, S_IFREG | S_IRWXUGO, 0);
972         if (!inode)
973                 goto out_dentry;
974
975         hstate = hstate_inode(inode);
976         size += addr & ~huge_page_mask(hstate);
977         num_pages = ALIGN(size, huge_page_size(hstate)) >>
978                         huge_page_shift(hstate);
979         error = -ENOMEM;
980         if (hugetlb_reserve_pages(inode, 0, num_pages, NULL, acctflag))
981                 goto out_inode;
982
983         d_instantiate(path.dentry, inode);
984         inode->i_size = size;
985         clear_nlink(inode);
986
987         error = -ENFILE;
988         file = alloc_file(&path, FMODE_WRITE | FMODE_READ,
989                         &hugetlbfs_file_operations);
990         if (!file)
991                 goto out_dentry; /* inode is already attached */
992
993         return file;
994
995 out_inode:
996         iput(inode);
997 out_dentry:
998         path_put(&path);
999 out_shm_unlock:
1000         if (*user) {
1001                 user_shm_unlock(size, *user);
1002                 *user = NULL;
1003         }
1004         return ERR_PTR(error);
1005 }
1006
1007 static int __init init_hugetlbfs_fs(void)
1008 {
1009         int error;
1010         struct vfsmount *vfsmount;
1011
1012         error = bdi_init(&hugetlbfs_backing_dev_info);
1013         if (error)
1014                 return error;
1015
1016         error = -ENOMEM;
1017         hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
1018                                         sizeof(struct hugetlbfs_inode_info),
1019                                         0, 0, init_once);
1020         if (hugetlbfs_inode_cachep == NULL)
1021                 goto out2;
1022
1023         error = register_filesystem(&hugetlbfs_fs_type);
1024         if (error)
1025                 goto out;
1026
1027         vfsmount = kern_mount(&hugetlbfs_fs_type);
1028
1029         if (!IS_ERR(vfsmount)) {
1030                 hugetlbfs_vfsmount = vfsmount;
1031                 return 0;
1032         }
1033
1034         error = PTR_ERR(vfsmount);
1035
1036  out:
1037         kmem_cache_destroy(hugetlbfs_inode_cachep);
1038  out2:
1039         bdi_destroy(&hugetlbfs_backing_dev_info);
1040         return error;
1041 }
1042
1043 static void __exit exit_hugetlbfs_fs(void)
1044 {
1045         kmem_cache_destroy(hugetlbfs_inode_cachep);
1046         kern_unmount(hugetlbfs_vfsmount);
1047         unregister_filesystem(&hugetlbfs_fs_type);
1048         bdi_destroy(&hugetlbfs_backing_dev_info);
1049 }
1050
1051 module_init(init_hugetlbfs_fs)
1052 module_exit(exit_hugetlbfs_fs)
1053
1054 MODULE_LICENSE("GPL");