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