Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

Linux/fs/hugetlbfs/inode.c

  1 /*
  2  * hugetlbpage-backed filesystem.  Based on ramfs.
  3  *
  4  * Nadia Yvette Chambers, 2002
  5  *
  6  * Copyright (C) 2002 Linus Torvalds.
  7  * License: GPL
  8  */
  9 
 10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 11 
 12 #include <linux/thread_info.h>
 13 #include <asm/current.h>
 14 #include <linux/sched.h>                /* remove ASAP */
 15 #include <linux/falloc.h>
 16 #include <linux/fs.h>
 17 #include <linux/mount.h>
 18 #include <linux/file.h>
 19 #include <linux/kernel.h>
 20 #include <linux/writeback.h>
 21 #include <linux/pagemap.h>
 22 #include <linux/highmem.h>
 23 #include <linux/init.h>
 24 #include <linux/string.h>
 25 #include <linux/capability.h>
 26 #include <linux/ctype.h>
 27 #include <linux/backing-dev.h>
 28 #include <linux/hugetlb.h>
 29 #include <linux/pagevec.h>
 30 #include <linux/parser.h>
 31 #include <linux/mman.h>
 32 #include <linux/slab.h>
 33 #include <linux/dnotify.h>
 34 #include <linux/statfs.h>
 35 #include <linux/security.h>
 36 #include <linux/magic.h>
 37 #include <linux/migrate.h>
 38 #include <linux/uio.h>
 39 
 40 #include <linux/uaccess.h>
 41 
 42 static const struct super_operations hugetlbfs_ops;
 43 static const struct address_space_operations hugetlbfs_aops;
 44 const struct file_operations hugetlbfs_file_operations;
 45 static const struct inode_operations hugetlbfs_dir_inode_operations;
 46 static const struct inode_operations hugetlbfs_inode_operations;
 47 
 48 struct hugetlbfs_config {
 49         kuid_t   uid;
 50         kgid_t   gid;
 51         umode_t mode;
 52         long    max_hpages;
 53         long    nr_inodes;
 54         struct hstate *hstate;
 55         long    min_hpages;
 56 };
 57 
 58 struct hugetlbfs_inode_info {
 59         struct shared_policy policy;
 60         struct inode vfs_inode;
 61 };
 62 
 63 static inline struct hugetlbfs_inode_info *HUGETLBFS_I(struct inode *inode)
 64 {
 65         return container_of(inode, struct hugetlbfs_inode_info, vfs_inode);
 66 }
 67 
 68 int sysctl_hugetlb_shm_group;
 69 
 70 enum {
 71         Opt_size, Opt_nr_inodes,
 72         Opt_mode, Opt_uid, Opt_gid,
 73         Opt_pagesize, Opt_min_size,
 74         Opt_err,
 75 };
 76 
 77 static const match_table_t tokens = {
 78         {Opt_size,      "size=%s"},
 79         {Opt_nr_inodes, "nr_inodes=%s"},
 80         {Opt_mode,      "mode=%o"},
 81         {Opt_uid,       "uid=%u"},
 82         {Opt_gid,       "gid=%u"},
 83         {Opt_pagesize,  "pagesize=%s"},
 84         {Opt_min_size,  "min_size=%s"},
 85         {Opt_err,       NULL},
 86 };
 87 
 88 #ifdef CONFIG_NUMA
 89 static inline void hugetlb_set_vma_policy(struct vm_area_struct *vma,
 90                                         struct inode *inode, pgoff_t index)
 91 {
 92         vma->vm_policy = mpol_shared_policy_lookup(&HUGETLBFS_I(inode)->policy,
 93                                                         index);
 94 }
 95 
 96 static inline void hugetlb_drop_vma_policy(struct vm_area_struct *vma)
 97 {
 98         mpol_cond_put(vma->vm_policy);
 99 }
100 #else
101 static inline void hugetlb_set_vma_policy(struct vm_area_struct *vma,
102                                         struct inode *inode, pgoff_t index)
103 {
104 }
105 
106 static inline void hugetlb_drop_vma_policy(struct vm_area_struct *vma)
107 {
108 }
109 #endif
110 
111 static void huge_pagevec_release(struct pagevec *pvec)
112 {
113         int i;
114 
115         for (i = 0; i < pagevec_count(pvec); ++i)
116                 put_page(pvec->pages[i]);
117 
118         pagevec_reinit(pvec);
119 }
120 
121 static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
122 {
123         struct inode *inode = file_inode(file);
124         loff_t len, vma_len;
125         int ret;
126         struct hstate *h = hstate_file(file);
127 
128         /*
129          * vma address alignment (but not the pgoff alignment) has
130          * already been checked by prepare_hugepage_range.  If you add
131          * any error returns here, do so after setting VM_HUGETLB, so
132          * is_vm_hugetlb_page tests below unmap_region go the right
133          * way when do_mmap_pgoff unwinds (may be important on powerpc
134          * and ia64).
135          */
136         vma->vm_flags |= VM_HUGETLB | VM_DONTEXPAND;
137         vma->vm_ops = &hugetlb_vm_ops;
138 
139         if (vma->vm_pgoff & (~huge_page_mask(h) >> PAGE_SHIFT))
140                 return -EINVAL;
141 
142         vma_len = (loff_t)(vma->vm_end - vma->vm_start);
143 
144         inode_lock(inode);
145         file_accessed(file);
146 
147         ret = -ENOMEM;
148         len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
149 
150         if (hugetlb_reserve_pages(inode,
151                                 vma->vm_pgoff >> huge_page_order(h),
152                                 len >> huge_page_shift(h), vma,
153                                 vma->vm_flags))
154                 goto out;
155 
156         ret = 0;
157         if (vma->vm_flags & VM_WRITE && inode->i_size < len)
158                 inode->i_size = len;
159 out:
160         inode_unlock(inode);
161 
162         return ret;
163 }
164 
165 /*
166  * Called under down_write(mmap_sem).
167  */
168 
169 #ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
170 static unsigned long
171 hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
172                 unsigned long len, unsigned long pgoff, unsigned long flags)
173 {
174         struct mm_struct *mm = current->mm;
175         struct vm_area_struct *vma;
176         struct hstate *h = hstate_file(file);
177         struct vm_unmapped_area_info info;
178 
179         if (len & ~huge_page_mask(h))
180                 return -EINVAL;
181         if (len > TASK_SIZE)
182                 return -ENOMEM;
183 
184         if (flags & MAP_FIXED) {
185                 if (prepare_hugepage_range(file, addr, len))
186                         return -EINVAL;
187                 return addr;
188         }
189 
190         if (addr) {
191                 addr = ALIGN(addr, huge_page_size(h));
192                 vma = find_vma(mm, addr);
193                 if (TASK_SIZE - len >= addr &&
194                     (!vma || addr + len <= vma->vm_start))
195                         return addr;
196         }
197 
198         info.flags = 0;
199         info.length = len;
200         info.low_limit = TASK_UNMAPPED_BASE;
201         info.high_limit = TASK_SIZE;
202         info.align_mask = PAGE_MASK & ~huge_page_mask(h);
203         info.align_offset = 0;
204         return vm_unmapped_area(&info);
205 }
206 #endif
207 
208 static size_t
209 hugetlbfs_read_actor(struct page *page, unsigned long offset,
210                         struct iov_iter *to, unsigned long size)
211 {
212         size_t copied = 0;
213         int i, chunksize;
214 
215         /* Find which 4k chunk and offset with in that chunk */
216         i = offset >> PAGE_SHIFT;
217         offset = offset & ~PAGE_MASK;
218 
219         while (size) {
220                 size_t n;
221                 chunksize = PAGE_SIZE;
222                 if (offset)
223                         chunksize -= offset;
224                 if (chunksize > size)
225                         chunksize = size;
226                 n = copy_page_to_iter(&page[i], offset, chunksize, to);
227                 copied += n;
228                 if (n != chunksize)
229                         return copied;
230                 offset = 0;
231                 size -= chunksize;
232                 i++;
233         }
234         return copied;
235 }
236 
237 /*
238  * Support for read() - Find the page attached to f_mapping and copy out the
239  * data. Its *very* similar to do_generic_mapping_read(), we can't use that
240  * since it has PAGE_SIZE assumptions.
241  */
242 static ssize_t hugetlbfs_read_iter(struct kiocb *iocb, struct iov_iter *to)
243 {
244         struct file *file = iocb->ki_filp;
245         struct hstate *h = hstate_file(file);
246         struct address_space *mapping = file->f_mapping;
247         struct inode *inode = mapping->host;
248         unsigned long index = iocb->ki_pos >> huge_page_shift(h);
249         unsigned long offset = iocb->ki_pos & ~huge_page_mask(h);
250         unsigned long end_index;
251         loff_t isize;
252         ssize_t retval = 0;
253 
254         while (iov_iter_count(to)) {
255                 struct page *page;
256                 size_t nr, copied;
257 
258                 /* nr is the maximum number of bytes to copy from this page */
259                 nr = huge_page_size(h);
260                 isize = i_size_read(inode);
261                 if (!isize)
262                         break;
263                 end_index = (isize - 1) >> huge_page_shift(h);
264                 if (index > end_index)
265                         break;
266                 if (index == end_index) {
267                         nr = ((isize - 1) & ~huge_page_mask(h)) + 1;
268                         if (nr <= offset)
269                                 break;
270                 }
271                 nr = nr - offset;
272 
273                 /* Find the page */
274                 page = find_lock_page(mapping, index);
275                 if (unlikely(page == NULL)) {
276                         /*
277                          * We have a HOLE, zero out the user-buffer for the
278                          * length of the hole or request.
279                          */
280                         copied = iov_iter_zero(nr, to);
281                 } else {
282                         unlock_page(page);
283 
284                         /*
285                          * We have the page, copy it to user space buffer.
286                          */
287                         copied = hugetlbfs_read_actor(page, offset, to, nr);
288                         put_page(page);
289                 }
290                 offset += copied;
291                 retval += copied;
292                 if (copied != nr && iov_iter_count(to)) {
293                         if (!retval)
294                                 retval = -EFAULT;
295                         break;
296                 }
297                 index += offset >> huge_page_shift(h);
298                 offset &= ~huge_page_mask(h);
299         }
300         iocb->ki_pos = ((loff_t)index << huge_page_shift(h)) + offset;
301         return retval;
302 }
303 
304 static int hugetlbfs_write_begin(struct file *file,
305                         struct address_space *mapping,
306                         loff_t pos, unsigned len, unsigned flags,
307                         struct page **pagep, void **fsdata)
308 {
309         return -EINVAL;
310 }
311 
312 static int hugetlbfs_write_end(struct file *file, struct address_space *mapping,
313                         loff_t pos, unsigned len, unsigned copied,
314                         struct page *page, void *fsdata)
315 {
316         BUG();
317         return -EINVAL;
318 }
319 
320 static void remove_huge_page(struct page *page)
321 {
322         ClearPageDirty(page);
323         ClearPageUptodate(page);
324         delete_from_page_cache(page);
325 }
326 
327 static void
328 hugetlb_vmdelete_list(struct rb_root *root, pgoff_t start, pgoff_t end)
329 {
330         struct vm_area_struct *vma;
331 
332         /*
333          * end == 0 indicates that the entire range after
334          * start should be unmapped.
335          */
336         vma_interval_tree_foreach(vma, root, start, end ? end : ULONG_MAX) {
337                 unsigned long v_offset;
338                 unsigned long v_end;
339 
340                 /*
341                  * Can the expression below overflow on 32-bit arches?
342                  * No, because the interval tree returns us only those vmas
343                  * which overlap the truncated area starting at pgoff,
344                  * and no vma on a 32-bit arch can span beyond the 4GB.
345                  */
346                 if (vma->vm_pgoff < start)
347                         v_offset = (start - vma->vm_pgoff) << PAGE_SHIFT;
348                 else
349                         v_offset = 0;
350 
351                 if (!end)
352                         v_end = vma->vm_end;
353                 else {
354                         v_end = ((end - vma->vm_pgoff) << PAGE_SHIFT)
355                                                         + vma->vm_start;
356                         if (v_end > vma->vm_end)
357                                 v_end = vma->vm_end;
358                 }
359 
360                 unmap_hugepage_range(vma, vma->vm_start + v_offset, v_end,
361                                                                         NULL);
362         }
363 }
364 
365 /*
366  * remove_inode_hugepages handles two distinct cases: truncation and hole
367  * punch.  There are subtle differences in operation for each case.
368  *
369  * truncation is indicated by end of range being LLONG_MAX
370  *      In this case, we first scan the range and release found pages.
371  *      After releasing pages, hugetlb_unreserve_pages cleans up region/reserv
372  *      maps and global counts.  Page faults can not race with truncation
373  *      in this routine.  hugetlb_no_page() prevents page faults in the
374  *      truncated range.  It checks i_size before allocation, and again after
375  *      with the page table lock for the page held.  The same lock must be
376  *      acquired to unmap a page.
377  * hole punch is indicated if end is not LLONG_MAX
378  *      In the hole punch case we scan the range and release found pages.
379  *      Only when releasing a page is the associated region/reserv map
380  *      deleted.  The region/reserv map for ranges without associated
381  *      pages are not modified.  Page faults can race with hole punch.
382  *      This is indicated if we find a mapped page.
383  * Note: If the passed end of range value is beyond the end of file, but
384  * not LLONG_MAX this routine still performs a hole punch operation.
385  */
386 static void remove_inode_hugepages(struct inode *inode, loff_t lstart,
387                                    loff_t lend)
388 {
389         struct hstate *h = hstate_inode(inode);
390         struct address_space *mapping = &inode->i_data;
391         const pgoff_t start = lstart >> huge_page_shift(h);
392         const pgoff_t end = lend >> huge_page_shift(h);
393         struct vm_area_struct pseudo_vma;
394         struct pagevec pvec;
395         pgoff_t next;
396         int i, freed = 0;
397         long lookup_nr = PAGEVEC_SIZE;
398         bool truncate_op = (lend == LLONG_MAX);
399 
400         memset(&pseudo_vma, 0, sizeof(struct vm_area_struct));
401         pseudo_vma.vm_flags = (VM_HUGETLB | VM_MAYSHARE | VM_SHARED);
402         pagevec_init(&pvec, 0);
403         next = start;
404         while (next < end) {
405                 /*
406                  * Don't grab more pages than the number left in the range.
407                  */
408                 if (end - next < lookup_nr)
409                         lookup_nr = end - next;
410 
411                 /*
412                  * When no more pages are found, we are done.
413                  */
414                 if (!pagevec_lookup(&pvec, mapping, next, lookup_nr))
415                         break;
416 
417                 for (i = 0; i < pagevec_count(&pvec); ++i) {
418                         struct page *page = pvec.pages[i];
419                         u32 hash;
420 
421                         /*
422                          * The page (index) could be beyond end.  This is
423                          * only possible in the punch hole case as end is
424                          * max page offset in the truncate case.
425                          */
426                         next = page->index;
427                         if (next >= end)
428                                 break;
429 
430                         hash = hugetlb_fault_mutex_hash(h, current->mm,
431                                                         &pseudo_vma,
432                                                         mapping, next, 0);
433                         mutex_lock(&hugetlb_fault_mutex_table[hash]);
434 
435                         /*
436                          * If page is mapped, it was faulted in after being
437                          * unmapped in caller.  Unmap (again) now after taking
438                          * the fault mutex.  The mutex will prevent faults
439                          * until we finish removing the page.
440                          *
441                          * This race can only happen in the hole punch case.
442                          * Getting here in a truncate operation is a bug.
443                          */
444                         if (unlikely(page_mapped(page))) {
445                                 BUG_ON(truncate_op);
446 
447                                 i_mmap_lock_write(mapping);
448                                 hugetlb_vmdelete_list(&mapping->i_mmap,
449                                         next * pages_per_huge_page(h),
450                                         (next + 1) * pages_per_huge_page(h));
451                                 i_mmap_unlock_write(mapping);
452                         }
453 
454                         lock_page(page);
455                         /*
456                          * We must free the huge page and remove from page
457                          * cache (remove_huge_page) BEFORE removing the
458                          * region/reserve map (hugetlb_unreserve_pages).  In
459                          * rare out of memory conditions, removal of the
460                          * region/reserve map could fail. Correspondingly,
461                          * the subpool and global reserve usage count can need
462                          * to be adjusted.
463                          */
464                         VM_BUG_ON(PagePrivate(page));
465                         remove_huge_page(page);
466                         freed++;
467                         if (!truncate_op) {
468                                 if (unlikely(hugetlb_unreserve_pages(inode,
469                                                         next, next + 1, 1)))
470                                         hugetlb_fix_reserve_counts(inode);
471                         }
472 
473                         unlock_page(page);
474                         mutex_unlock(&hugetlb_fault_mutex_table[hash]);
475                 }
476                 ++next;
477                 huge_pagevec_release(&pvec);
478                 cond_resched();
479         }
480 
481         if (truncate_op)
482                 (void)hugetlb_unreserve_pages(inode, start, LONG_MAX, freed);
483 }
484 
485 static void hugetlbfs_evict_inode(struct inode *inode)
486 {
487         struct resv_map *resv_map;
488 
489         remove_inode_hugepages(inode, 0, LLONG_MAX);
490         resv_map = (struct resv_map *)inode->i_mapping->private_data;
491         /* root inode doesn't have the resv_map, so we should check it */
492         if (resv_map)
493                 resv_map_release(&resv_map->refs);
494         clear_inode(inode);
495 }
496 
497 static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
498 {
499         pgoff_t pgoff;
500         struct address_space *mapping = inode->i_mapping;
501         struct hstate *h = hstate_inode(inode);
502 
503         BUG_ON(offset & ~huge_page_mask(h));
504         pgoff = offset >> PAGE_SHIFT;
505 
506         i_size_write(inode, offset);
507         i_mmap_lock_write(mapping);
508         if (!RB_EMPTY_ROOT(&mapping->i_mmap))
509                 hugetlb_vmdelete_list(&mapping->i_mmap, pgoff, 0);
510         i_mmap_unlock_write(mapping);
511         remove_inode_hugepages(inode, offset, LLONG_MAX);
512         return 0;
513 }
514 
515 static long hugetlbfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
516 {
517         struct hstate *h = hstate_inode(inode);
518         loff_t hpage_size = huge_page_size(h);
519         loff_t hole_start, hole_end;
520 
521         /*
522          * For hole punch round up the beginning offset of the hole and
523          * round down the end.
524          */
525         hole_start = round_up(offset, hpage_size);
526         hole_end = round_down(offset + len, hpage_size);
527 
528         if (hole_end > hole_start) {
529                 struct address_space *mapping = inode->i_mapping;
530 
531                 inode_lock(inode);
532                 i_mmap_lock_write(mapping);
533                 if (!RB_EMPTY_ROOT(&mapping->i_mmap))
534                         hugetlb_vmdelete_list(&mapping->i_mmap,
535                                                 hole_start >> PAGE_SHIFT,
536                                                 hole_end  >> PAGE_SHIFT);
537                 i_mmap_unlock_write(mapping);
538                 remove_inode_hugepages(inode, hole_start, hole_end);
539                 inode_unlock(inode);
540         }
541 
542         return 0;
543 }
544 
545 static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
546                                 loff_t len)
547 {
548         struct inode *inode = file_inode(file);
549         struct address_space *mapping = inode->i_mapping;
550         struct hstate *h = hstate_inode(inode);
551         struct vm_area_struct pseudo_vma;
552         struct mm_struct *mm = current->mm;
553         loff_t hpage_size = huge_page_size(h);
554         unsigned long hpage_shift = huge_page_shift(h);
555         pgoff_t start, index, end;
556         int error;
557         u32 hash;
558 
559         if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
560                 return -EOPNOTSUPP;
561 
562         if (mode & FALLOC_FL_PUNCH_HOLE)
563                 return hugetlbfs_punch_hole(inode, offset, len);
564 
565         /*
566          * Default preallocate case.
567          * For this range, start is rounded down and end is rounded up
568          * as well as being converted to page offsets.
569          */
570         start = offset >> hpage_shift;
571         end = (offset + len + hpage_size - 1) >> hpage_shift;
572 
573         inode_lock(inode);
574 
575         /* We need to check rlimit even when FALLOC_FL_KEEP_SIZE */
576         error = inode_newsize_ok(inode, offset + len);
577         if (error)
578                 goto out;
579 
580         /*
581          * Initialize a pseudo vma as this is required by the huge page
582          * allocation routines.  If NUMA is configured, use page index
583          * as input to create an allocation policy.
584          */
585         memset(&pseudo_vma, 0, sizeof(struct vm_area_struct));
586         pseudo_vma.vm_flags = (VM_HUGETLB | VM_MAYSHARE | VM_SHARED);
587         pseudo_vma.vm_file = file;
588 
589         for (index = start; index < end; index++) {
590                 /*
591                  * This is supposed to be the vaddr where the page is being
592                  * faulted in, but we have no vaddr here.
593                  */
594                 struct page *page;
595                 unsigned long addr;
596                 int avoid_reserve = 0;
597 
598                 cond_resched();
599 
600                 /*
601                  * fallocate(2) manpage permits EINTR; we may have been
602                  * interrupted because we are using up too much memory.
603                  */
604                 if (signal_pending(current)) {
605                         error = -EINTR;
606                         break;
607                 }
608 
609                 /* Set numa allocation policy based on index */
610                 hugetlb_set_vma_policy(&pseudo_vma, inode, index);
611 
612                 /* addr is the offset within the file (zero based) */
613                 addr = index * hpage_size;
614 
615                 /* mutex taken here, fault path and hole punch */
616                 hash = hugetlb_fault_mutex_hash(h, mm, &pseudo_vma, mapping,
617                                                 index, addr);
618                 mutex_lock(&hugetlb_fault_mutex_table[hash]);
619 
620                 /* See if already present in mapping to avoid alloc/free */
621                 page = find_get_page(mapping, index);
622                 if (page) {
623                         put_page(page);
624                         mutex_unlock(&hugetlb_fault_mutex_table[hash]);
625                         hugetlb_drop_vma_policy(&pseudo_vma);
626                         continue;
627                 }
628 
629                 /* Allocate page and add to page cache */
630                 page = alloc_huge_page(&pseudo_vma, addr, avoid_reserve);
631                 hugetlb_drop_vma_policy(&pseudo_vma);
632                 if (IS_ERR(page)) {
633                         mutex_unlock(&hugetlb_fault_mutex_table[hash]);
634                         error = PTR_ERR(page);
635                         goto out;
636                 }
637                 clear_huge_page(page, addr, pages_per_huge_page(h));
638                 __SetPageUptodate(page);
639                 error = huge_add_to_page_cache(page, mapping, index);
640                 if (unlikely(error)) {
641                         put_page(page);
642                         mutex_unlock(&hugetlb_fault_mutex_table[hash]);
643                         goto out;
644                 }
645 
646                 mutex_unlock(&hugetlb_fault_mutex_table[hash]);
647 
648                 /*
649                  * page_put due to reference from alloc_huge_page()
650                  * unlock_page because locked by add_to_page_cache()
651                  */
652                 put_page(page);
653                 unlock_page(page);
654         }
655 
656         if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size)
657                 i_size_write(inode, offset + len);
658         inode->i_ctime = current_time(inode);
659 out:
660         inode_unlock(inode);
661         return error;
662 }
663 
664 static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
665 {
666         struct inode *inode = d_inode(dentry);
667         struct hstate *h = hstate_inode(inode);
668         int error;
669         unsigned int ia_valid = attr->ia_valid;
670 
671         BUG_ON(!inode);
672 
673         error = setattr_prepare(dentry, attr);
674         if (error)
675                 return error;
676 
677         if (ia_valid & ATTR_SIZE) {
678                 error = -EINVAL;
679                 if (attr->ia_size & ~huge_page_mask(h))
680                         return -EINVAL;
681                 error = hugetlb_vmtruncate(inode, attr->ia_size);
682                 if (error)
683                         return error;
684         }
685 
686         setattr_copy(inode, attr);
687         mark_inode_dirty(inode);
688         return 0;
689 }
690 
691 static struct inode *hugetlbfs_get_root(struct super_block *sb,
692                                         struct hugetlbfs_config *config)
693 {
694         struct inode *inode;
695 
696         inode = new_inode(sb);
697         if (inode) {
698                 struct hugetlbfs_inode_info *info;
699                 inode->i_ino = get_next_ino();
700                 inode->i_mode = S_IFDIR | config->mode;
701                 inode->i_uid = config->uid;
702                 inode->i_gid = config->gid;
703                 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
704                 info = HUGETLBFS_I(inode);
705                 mpol_shared_policy_init(&info->policy, NULL);
706                 inode->i_op = &hugetlbfs_dir_inode_operations;
707                 inode->i_fop = &simple_dir_operations;
708                 /* directory inodes start off with i_nlink == 2 (for "." entry) */
709                 inc_nlink(inode);
710                 lockdep_annotate_inode_mutex_key(inode);
711         }
712         return inode;
713 }
714 
715 /*
716  * Hugetlbfs is not reclaimable; therefore its i_mmap_rwsem will never
717  * be taken from reclaim -- unlike regular filesystems. This needs an
718  * annotation because huge_pmd_share() does an allocation under hugetlb's
719  * i_mmap_rwsem.
720  */
721 static struct lock_class_key hugetlbfs_i_mmap_rwsem_key;
722 
723 static struct inode *hugetlbfs_get_inode(struct super_block *sb,
724                                         struct inode *dir,
725                                         umode_t mode, dev_t dev)
726 {
727         struct inode *inode;
728         struct resv_map *resv_map;
729 
730         resv_map = resv_map_alloc();
731         if (!resv_map)
732                 return NULL;
733 
734         inode = new_inode(sb);
735         if (inode) {
736                 struct hugetlbfs_inode_info *info;
737                 inode->i_ino = get_next_ino();
738                 inode_init_owner(inode, dir, mode);
739                 lockdep_set_class(&inode->i_mapping->i_mmap_rwsem,
740                                 &hugetlbfs_i_mmap_rwsem_key);
741                 inode->i_mapping->a_ops = &hugetlbfs_aops;
742                 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
743                 inode->i_mapping->private_data = resv_map;
744                 info = HUGETLBFS_I(inode);
745                 /*
746                  * The policy is initialized here even if we are creating a
747                  * private inode because initialization simply creates an
748                  * an empty rb tree and calls rwlock_init(), later when we
749                  * call mpol_free_shared_policy() it will just return because
750                  * the rb tree will still be empty.
751                  */
752                 mpol_shared_policy_init(&info->policy, NULL);
753                 switch (mode & S_IFMT) {
754                 default:
755                         init_special_inode(inode, mode, dev);
756                         break;
757                 case S_IFREG:
758                         inode->i_op = &hugetlbfs_inode_operations;
759                         inode->i_fop = &hugetlbfs_file_operations;
760                         break;
761                 case S_IFDIR:
762                         inode->i_op = &hugetlbfs_dir_inode_operations;
763                         inode->i_fop = &simple_dir_operations;
764 
765                         /* directory inodes start off with i_nlink == 2 (for "." entry) */
766                         inc_nlink(inode);
767                         break;
768                 case S_IFLNK:
769                         inode->i_op = &page_symlink_inode_operations;
770                         inode_nohighmem(inode);
771                         break;
772                 }
773                 lockdep_annotate_inode_mutex_key(inode);
774         } else
775                 kref_put(&resv_map->refs, resv_map_release);
776 
777         return inode;
778 }
779 
780 /*
781  * File creation. Allocate an inode, and we're done..
782  */
783 static int hugetlbfs_mknod(struct inode *dir,
784                         struct dentry *dentry, umode_t mode, dev_t dev)
785 {
786         struct inode *inode;
787         int error = -ENOSPC;
788 
789         inode = hugetlbfs_get_inode(dir->i_sb, dir, mode, dev);
790         if (inode) {
791                 dir->i_ctime = dir->i_mtime = current_time(dir);
792                 d_instantiate(dentry, inode);
793                 dget(dentry);   /* Extra count - pin the dentry in core */
794                 error = 0;
795         }
796         return error;
797 }
798 
799 static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
800 {
801         int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0);
802         if (!retval)
803                 inc_nlink(dir);
804         return retval;
805 }
806 
807 static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl)
808 {
809         return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0);
810 }
811 
812 static int hugetlbfs_symlink(struct inode *dir,
813                         struct dentry *dentry, const char *symname)
814 {
815         struct inode *inode;
816         int error = -ENOSPC;
817 
818         inode = hugetlbfs_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0);
819         if (inode) {
820                 int l = strlen(symname)+1;
821                 error = page_symlink(inode, symname, l);
822                 if (!error) {
823                         d_instantiate(dentry, inode);
824                         dget(dentry);
825                 } else
826                         iput(inode);
827         }
828         dir->i_ctime = dir->i_mtime = current_time(dir);
829 
830         return error;
831 }
832 
833 /*
834  * mark the head page dirty
835  */
836 static int hugetlbfs_set_page_dirty(struct page *page)
837 {
838         struct page *head = compound_head(page);
839 
840         SetPageDirty(head);
841         return 0;
842 }
843 
844 static int hugetlbfs_migrate_page(struct address_space *mapping,
845                                 struct page *newpage, struct page *page,
846                                 enum migrate_mode mode)
847 {
848         int rc;
849 
850         rc = migrate_huge_page_move_mapping(mapping, newpage, page);
851         if (rc != MIGRATEPAGE_SUCCESS)
852                 return rc;
853         migrate_page_copy(newpage, page);
854 
855         return MIGRATEPAGE_SUCCESS;
856 }
857 
858 static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
859 {
860         struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
861         struct hstate *h = hstate_inode(d_inode(dentry));
862 
863         buf->f_type = HUGETLBFS_MAGIC;
864         buf->f_bsize = huge_page_size(h);
865         if (sbinfo) {
866                 spin_lock(&sbinfo->stat_lock);
867                 /* If no limits set, just report 0 for max/free/used
868                  * blocks, like simple_statfs() */
869                 if (sbinfo->spool) {
870                         long free_pages;
871 
872                         spin_lock(&sbinfo->spool->lock);
873                         buf->f_blocks = sbinfo->spool->max_hpages;
874                         free_pages = sbinfo->spool->max_hpages
875                                 - sbinfo->spool->used_hpages;
876                         buf->f_bavail = buf->f_bfree = free_pages;
877                         spin_unlock(&sbinfo->spool->lock);
878                         buf->f_files = sbinfo->max_inodes;
879                         buf->f_ffree = sbinfo->free_inodes;
880                 }
881                 spin_unlock(&sbinfo->stat_lock);
882         }
883         buf->f_namelen = NAME_MAX;
884         return 0;
885 }
886 
887 static void hugetlbfs_put_super(struct super_block *sb)
888 {
889         struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb);
890 
891         if (sbi) {
892                 sb->s_fs_info = NULL;
893 
894                 if (sbi->spool)
895                         hugepage_put_subpool(sbi->spool);
896 
897                 kfree(sbi);
898         }
899 }
900 
901 static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo)
902 {
903         if (sbinfo->free_inodes >= 0) {
904                 spin_lock(&sbinfo->stat_lock);
905                 if (unlikely(!sbinfo->free_inodes)) {
906                         spin_unlock(&sbinfo->stat_lock);
907                         return 0;
908                 }
909                 sbinfo->free_inodes--;
910                 spin_unlock(&sbinfo->stat_lock);
911         }
912 
913         return 1;
914 }
915 
916 static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
917 {
918         if (sbinfo->free_inodes >= 0) {
919                 spin_lock(&sbinfo->stat_lock);
920                 sbinfo->free_inodes++;
921                 spin_unlock(&sbinfo->stat_lock);
922         }
923 }
924 
925 
926 static struct kmem_cache *hugetlbfs_inode_cachep;
927 
928 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
929 {
930         struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
931         struct hugetlbfs_inode_info *p;
932 
933         if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
934                 return NULL;
935         p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL);
936         if (unlikely(!p)) {
937                 hugetlbfs_inc_free_inodes(sbinfo);
938                 return NULL;
939         }
940         return &p->vfs_inode;
941 }
942 
943 static void hugetlbfs_i_callback(struct rcu_head *head)
944 {
945         struct inode *inode = container_of(head, struct inode, i_rcu);
946         kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
947 }
948 
949 static void hugetlbfs_destroy_inode(struct inode *inode)
950 {
951         hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
952         mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
953         call_rcu(&inode->i_rcu, hugetlbfs_i_callback);
954 }
955 
956 static const struct address_space_operations hugetlbfs_aops = {
957         .write_begin    = hugetlbfs_write_begin,
958         .write_end      = hugetlbfs_write_end,
959         .set_page_dirty = hugetlbfs_set_page_dirty,
960         .migratepage    = hugetlbfs_migrate_page,
961 };
962 
963 
964 static void init_once(void *foo)
965 {
966         struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
967 
968         inode_init_once(&ei->vfs_inode);
969 }
970 
971 const struct file_operations hugetlbfs_file_operations = {
972         .read_iter              = hugetlbfs_read_iter,
973         .mmap                   = hugetlbfs_file_mmap,
974         .fsync                  = noop_fsync,
975         .get_unmapped_area      = hugetlb_get_unmapped_area,
976         .llseek                 = default_llseek,
977         .fallocate              = hugetlbfs_fallocate,
978 };
979 
980 static const struct inode_operations hugetlbfs_dir_inode_operations = {
981         .create         = hugetlbfs_create,
982         .lookup         = simple_lookup,
983         .link           = simple_link,
984         .unlink         = simple_unlink,
985         .symlink        = hugetlbfs_symlink,
986         .mkdir          = hugetlbfs_mkdir,
987         .rmdir          = simple_rmdir,
988         .mknod          = hugetlbfs_mknod,
989         .rename         = simple_rename,
990         .setattr        = hugetlbfs_setattr,
991 };
992 
993 static const struct inode_operations hugetlbfs_inode_operations = {
994         .setattr        = hugetlbfs_setattr,
995 };
996 
997 static const struct super_operations hugetlbfs_ops = {
998         .alloc_inode    = hugetlbfs_alloc_inode,
999         .destroy_inode  = hugetlbfs_destroy_inode,
1000         .evict_inode    = hugetlbfs_evict_inode,
1001         .statfs         = hugetlbfs_statfs,
1002         .put_super      = hugetlbfs_put_super,
1003         .show_options   = generic_show_options,
1004 };
1005 
1006 enum { NO_SIZE, SIZE_STD, SIZE_PERCENT };
1007 
1008 /*
1009  * Convert size option passed from command line to number of huge pages
1010  * in the pool specified by hstate.  Size option could be in bytes
1011  * (val_type == SIZE_STD) or percentage of the pool (val_type == SIZE_PERCENT).
1012  */
1013 static long long
1014 hugetlbfs_size_to_hpages(struct hstate *h, unsigned long long size_opt,
1015                                                                 int val_type)
1016 {
1017         if (val_type == NO_SIZE)
1018                 return -1;
1019 
1020         if (val_type == SIZE_PERCENT) {
1021                 size_opt <<= huge_page_shift(h);
1022                 size_opt *= h->max_huge_pages;
1023                 do_div(size_opt, 100);
1024         }
1025 
1026         size_opt >>= huge_page_shift(h);
1027         return size_opt;
1028 }
1029 
1030 static int
1031 hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
1032 {
1033         char *p, *rest;
1034         substring_t args[MAX_OPT_ARGS];
1035         int option;
1036         unsigned long long max_size_opt = 0, min_size_opt = 0;
1037         int max_val_type = NO_SIZE, min_val_type = NO_SIZE;
1038 
1039         if (!options)
1040                 return 0;
1041 
1042         while ((p = strsep(&options, ",")) != NULL) {
1043                 int token;
1044                 if (!*p)
1045                         continue;
1046 
1047                 token = match_token(p, tokens, args);
1048                 switch (token) {
1049                 case Opt_uid:
1050                         if (match_int(&args[0], &option))
1051                                 goto bad_val;
1052                         pconfig->uid = make_kuid(current_user_ns(), option);
1053                         if (!uid_valid(pconfig->uid))
1054                                 goto bad_val;
1055                         break;
1056 
1057                 case Opt_gid:
1058                         if (match_int(&args[0], &option))
1059                                 goto bad_val;
1060                         pconfig->gid = make_kgid(current_user_ns(), option);
1061                         if (!gid_valid(pconfig->gid))
1062                                 goto bad_val;
1063                         break;
1064 
1065                 case Opt_mode:
1066                         if (match_octal(&args[0], &option))
1067                                 goto bad_val;
1068                         pconfig->mode = option & 01777U;
1069                         break;
1070 
1071                 case Opt_size: {
1072                         /* memparse() will accept a K/M/G without a digit */
1073                         if (!isdigit(*args[0].from))
1074                                 goto bad_val;
1075                         max_size_opt = memparse(args[0].from, &rest);
1076                         max_val_type = SIZE_STD;
1077                         if (*rest == '%')
1078                                 max_val_type = SIZE_PERCENT;
1079                         break;
1080                 }
1081 
1082                 case Opt_nr_inodes:
1083                         /* memparse() will accept a K/M/G without a digit */
1084                         if (!isdigit(*args[0].from))
1085                                 goto bad_val;
1086                         pconfig->nr_inodes = memparse(args[0].from, &rest);
1087                         break;
1088 
1089                 case Opt_pagesize: {
1090                         unsigned long ps;
1091                         ps = memparse(args[0].from, &rest);
1092                         pconfig->hstate = size_to_hstate(ps);
1093                         if (!pconfig->hstate) {
1094                                 pr_err("Unsupported page size %lu MB\n",
1095                                         ps >> 20);
1096                                 return -EINVAL;
1097                         }
1098                         break;
1099                 }
1100 
1101                 case Opt_min_size: {
1102                         /* memparse() will accept a K/M/G without a digit */
1103                         if (!isdigit(*args[0].from))
1104                                 goto bad_val;
1105                         min_size_opt = memparse(args[0].from, &rest);
1106                         min_val_type = SIZE_STD;
1107                         if (*rest == '%')
1108                                 min_val_type = SIZE_PERCENT;
1109                         break;
1110                 }
1111 
1112                 default:
1113                         pr_err("Bad mount option: \"%s\"\n", p);
1114                         return -EINVAL;
1115                         break;
1116                 }
1117         }
1118 
1119         /*
1120          * Use huge page pool size (in hstate) to convert the size
1121          * options to number of huge pages.  If NO_SIZE, -1 is returned.
1122          */
1123         pconfig->max_hpages = hugetlbfs_size_to_hpages(pconfig->hstate,
1124                                                 max_size_opt, max_val_type);
1125         pconfig->min_hpages = hugetlbfs_size_to_hpages(pconfig->hstate,
1126                                                 min_size_opt, min_val_type);
1127 
1128         /*
1129          * If max_size was specified, then min_size must be smaller
1130          */
1131         if (max_val_type > NO_SIZE &&
1132             pconfig->min_hpages > pconfig->max_hpages) {
1133                 pr_err("minimum size can not be greater than maximum size\n");
1134                 return -EINVAL;
1135         }
1136 
1137         return 0;
1138 
1139 bad_val:
1140         pr_err("Bad value '%s' for mount option '%s'\n", args[0].from, p);
1141         return -EINVAL;
1142 }
1143 
1144 static int
1145 hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
1146 {
1147         int ret;
1148         struct hugetlbfs_config config;
1149         struct hugetlbfs_sb_info *sbinfo;
1150 
1151         save_mount_options(sb, data);
1152 
1153         config.max_hpages = -1; /* No limit on size by default */
1154         config.nr_inodes = -1; /* No limit on number of inodes by default */
1155         config.uid = current_fsuid();
1156         config.gid = current_fsgid();
1157         config.mode = 0755;
1158         config.hstate = &default_hstate;
1159         config.min_hpages = -1; /* No default minimum size */
1160         ret = hugetlbfs_parse_options(data, &config);
1161         if (ret)
1162                 return ret;
1163 
1164         sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL);
1165         if (!sbinfo)
1166                 return -ENOMEM;
1167         sb->s_fs_info = sbinfo;
1168         sbinfo->hstate = config.hstate;
1169         spin_lock_init(&sbinfo->stat_lock);
1170         sbinfo->max_inodes = config.nr_inodes;
1171         sbinfo->free_inodes = config.nr_inodes;
1172         sbinfo->spool = NULL;
1173         /*
1174          * Allocate and initialize subpool if maximum or minimum size is
1175          * specified.  Any needed reservations (for minimim size) are taken
1176          * taken when the subpool is created.
1177          */
1178         if (config.max_hpages != -1 || config.min_hpages != -1) {
1179                 sbinfo->spool = hugepage_new_subpool(config.hstate,
1180                                                         config.max_hpages,
1181                                                         config.min_hpages);
1182                 if (!sbinfo->spool)
1183                         goto out_free;
1184         }
1185         sb->s_maxbytes = MAX_LFS_FILESIZE;
1186         sb->s_blocksize = huge_page_size(config.hstate);
1187         sb->s_blocksize_bits = huge_page_shift(config.hstate);
1188         sb->s_magic = HUGETLBFS_MAGIC;
1189         sb->s_op = &hugetlbfs_ops;
1190         sb->s_time_gran = 1;
1191         sb->s_root = d_make_root(hugetlbfs_get_root(sb, &config));
1192         if (!sb->s_root)
1193                 goto out_free;
1194         return 0;
1195 out_free:
1196         kfree(sbinfo->spool);
1197         kfree(sbinfo);
1198         return -ENOMEM;
1199 }
1200 
1201 static struct dentry *hugetlbfs_mount(struct file_system_type *fs_type,
1202         int flags, const char *dev_name, void *data)
1203 {
1204         return mount_nodev(fs_type, flags, data, hugetlbfs_fill_super);
1205 }
1206 
1207 static struct file_system_type hugetlbfs_fs_type = {
1208         .name           = "hugetlbfs",
1209         .mount          = hugetlbfs_mount,
1210         .kill_sb        = kill_litter_super,
1211 };
1212 
1213 static struct vfsmount *hugetlbfs_vfsmount[HUGE_MAX_HSTATE];
1214 
1215 static int can_do_hugetlb_shm(void)
1216 {
1217         kgid_t shm_group;
1218         shm_group = make_kgid(&init_user_ns, sysctl_hugetlb_shm_group);
1219         return capable(CAP_IPC_LOCK) || in_group_p(shm_group);
1220 }
1221 
1222 static int get_hstate_idx(int page_size_log)
1223 {
1224         struct hstate *h = hstate_sizelog(page_size_log);
1225 
1226         if (!h)
1227                 return -1;
1228         return h - hstates;
1229 }
1230 
1231 static const struct dentry_operations anon_ops = {
1232         .d_dname = simple_dname
1233 };
1234 
1235 /*
1236  * Note that size should be aligned to proper hugepage size in caller side,
1237  * otherwise hugetlb_reserve_pages reserves one less hugepages than intended.
1238  */
1239 struct file *hugetlb_file_setup(const char *name, size_t size,
1240                                 vm_flags_t acctflag, struct user_struct **user,
1241                                 int creat_flags, int page_size_log)
1242 {
1243         struct file *file = ERR_PTR(-ENOMEM);
1244         struct inode *inode;
1245         struct path path;
1246         struct super_block *sb;
1247         struct qstr quick_string;
1248         int hstate_idx;
1249 
1250         hstate_idx = get_hstate_idx(page_size_log);
1251         if (hstate_idx < 0)
1252                 return ERR_PTR(-ENODEV);
1253 
1254         *user = NULL;
1255         if (!hugetlbfs_vfsmount[hstate_idx])
1256                 return ERR_PTR(-ENOENT);
1257 
1258         if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) {
1259                 *user = current_user();
1260                 if (user_shm_lock(size, *user)) {
1261                         task_lock(current);
1262                         pr_warn_once("%s (%d): Using mlock ulimits for SHM_HUGETLB is deprecated\n",
1263                                 current->comm, current->pid);
1264                         task_unlock(current);
1265                 } else {
1266                         *user = NULL;
1267                         return ERR_PTR(-EPERM);
1268                 }
1269         }
1270 
1271         sb = hugetlbfs_vfsmount[hstate_idx]->mnt_sb;
1272         quick_string.name = name;
1273         quick_string.len = strlen(quick_string.name);
1274         quick_string.hash = 0;
1275         path.dentry = d_alloc_pseudo(sb, &quick_string);
1276         if (!path.dentry)
1277                 goto out_shm_unlock;
1278 
1279         d_set_d_op(path.dentry, &anon_ops);
1280         path.mnt = mntget(hugetlbfs_vfsmount[hstate_idx]);
1281         file = ERR_PTR(-ENOSPC);
1282         inode = hugetlbfs_get_inode(sb, NULL, S_IFREG | S_IRWXUGO, 0);
1283         if (!inode)
1284                 goto out_dentry;
1285         if (creat_flags == HUGETLB_SHMFS_INODE)
1286                 inode->i_flags |= S_PRIVATE;
1287 
1288         file = ERR_PTR(-ENOMEM);
1289         if (hugetlb_reserve_pages(inode, 0,
1290                         size >> huge_page_shift(hstate_inode(inode)), NULL,
1291                         acctflag))
1292                 goto out_inode;
1293 
1294         d_instantiate(path.dentry, inode);
1295         inode->i_size = size;
1296         clear_nlink(inode);
1297 
1298         file = alloc_file(&path, FMODE_WRITE | FMODE_READ,
1299                         &hugetlbfs_file_operations);
1300         if (IS_ERR(file))
1301                 goto out_dentry; /* inode is already attached */
1302 
1303         return file;
1304 
1305 out_inode:
1306         iput(inode);
1307 out_dentry:
1308         path_put(&path);
1309 out_shm_unlock:
1310         if (*user) {
1311                 user_shm_unlock(size, *user);
1312                 *user = NULL;
1313         }
1314         return file;
1315 }
1316 
1317 static int __init init_hugetlbfs_fs(void)
1318 {
1319         struct hstate *h;
1320         int error;
1321         int i;
1322 
1323         if (!hugepages_supported()) {
1324                 pr_info("disabling because there are no supported hugepage sizes\n");
1325                 return -ENOTSUPP;
1326         }
1327 
1328         error = -ENOMEM;
1329         hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
1330                                         sizeof(struct hugetlbfs_inode_info),
1331                                         0, SLAB_ACCOUNT, init_once);
1332         if (hugetlbfs_inode_cachep == NULL)
1333                 goto out2;
1334 
1335         error = register_filesystem(&hugetlbfs_fs_type);
1336         if (error)
1337                 goto out;
1338 
1339         i = 0;
1340         for_each_hstate(h) {
1341                 char buf[50];
1342                 unsigned ps_kb = 1U << (h->order + PAGE_SHIFT - 10);
1343 
1344                 snprintf(buf, sizeof(buf), "pagesize=%uK", ps_kb);
1345                 hugetlbfs_vfsmount[i] = kern_mount_data(&hugetlbfs_fs_type,
1346                                                         buf);
1347 
1348                 if (IS_ERR(hugetlbfs_vfsmount[i])) {
1349                         pr_err("Cannot mount internal hugetlbfs for "
1350                                 "page size %uK", ps_kb);
1351                         error = PTR_ERR(hugetlbfs_vfsmount[i]);
1352                         hugetlbfs_vfsmount[i] = NULL;
1353                 }
1354                 i++;
1355         }
1356         /* Non default hstates are optional */
1357         if (!IS_ERR_OR_NULL(hugetlbfs_vfsmount[default_hstate_idx]))
1358                 return 0;
1359 
1360  out:
1361         kmem_cache_destroy(hugetlbfs_inode_cachep);
1362  out2:
1363         return error;
1364 }
1365 fs_initcall(init_hugetlbfs_fs)
1366 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us