2 * hugetlbpage-backed filesystem. Based on ramfs.
4 * Nadia Yvette Chambers, 2002
6 * Copyright (C) 2002 Linus Torvalds.
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11 #include <linux/module.h>
12 #include <linux/thread_info.h>
13 #include <asm/current.h>
14 #include <linux/sched.h> /* remove ASAP */
16 #include <linux/mount.h>
17 #include <linux/file.h>
18 #include <linux/kernel.h>
19 #include <linux/writeback.h>
20 #include <linux/pagemap.h>
21 #include <linux/highmem.h>
22 #include <linux/init.h>
23 #include <linux/string.h>
24 #include <linux/capability.h>
25 #include <linux/ctype.h>
26 #include <linux/backing-dev.h>
27 #include <linux/hugetlb.h>
28 #include <linux/pagevec.h>
29 #include <linux/parser.h>
30 #include <linux/mman.h>
31 #include <linux/slab.h>
32 #include <linux/dnotify.h>
33 #include <linux/statfs.h>
34 #include <linux/security.h>
35 #include <linux/magic.h>
36 #include <linux/migrate.h>
37 #include <linux/uio.h>
39 #include <asm/uaccess.h>
41 static const struct super_operations hugetlbfs_ops;
42 static const struct address_space_operations hugetlbfs_aops;
43 const struct file_operations hugetlbfs_file_operations;
44 static const struct inode_operations hugetlbfs_dir_inode_operations;
45 static const struct inode_operations hugetlbfs_inode_operations;
47 struct hugetlbfs_config {
53 struct hstate *hstate;
56 struct hugetlbfs_inode_info {
57 struct shared_policy policy;
58 struct inode vfs_inode;
61 static inline struct hugetlbfs_inode_info *HUGETLBFS_I(struct inode *inode)
63 return container_of(inode, struct hugetlbfs_inode_info, vfs_inode);
66 int sysctl_hugetlb_shm_group;
69 Opt_size, Opt_nr_inodes,
70 Opt_mode, Opt_uid, Opt_gid,
75 static const match_table_t tokens = {
76 {Opt_size, "size=%s"},
77 {Opt_nr_inodes, "nr_inodes=%s"},
78 {Opt_mode, "mode=%o"},
81 {Opt_pagesize, "pagesize=%s"},
85 static void huge_pagevec_release(struct pagevec *pvec)
89 for (i = 0; i < pagevec_count(pvec); ++i)
90 put_page(pvec->pages[i]);
95 static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
97 struct inode *inode = file_inode(file);
100 struct hstate *h = hstate_file(file);
103 * vma address alignment (but not the pgoff alignment) has
104 * already been checked by prepare_hugepage_range. If you add
105 * any error returns here, do so after setting VM_HUGETLB, so
106 * is_vm_hugetlb_page tests below unmap_region go the right
107 * way when do_mmap_pgoff unwinds (may be important on powerpc
110 vma->vm_flags |= VM_HUGETLB | VM_DONTEXPAND;
111 vma->vm_ops = &hugetlb_vm_ops;
113 if (vma->vm_pgoff & (~huge_page_mask(h) >> PAGE_SHIFT))
116 vma_len = (loff_t)(vma->vm_end - vma->vm_start);
118 mutex_lock(&inode->i_mutex);
122 len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
124 if (hugetlb_reserve_pages(inode,
125 vma->vm_pgoff >> huge_page_order(h),
126 len >> huge_page_shift(h), vma,
131 hugetlb_prefault_arch_hook(vma->vm_mm);
132 if (vma->vm_flags & VM_WRITE && inode->i_size < len)
135 mutex_unlock(&inode->i_mutex);
141 * Called under down_write(mmap_sem).
144 #ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
146 hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
147 unsigned long len, unsigned long pgoff, unsigned long flags)
149 struct mm_struct *mm = current->mm;
150 struct vm_area_struct *vma;
151 struct hstate *h = hstate_file(file);
152 struct vm_unmapped_area_info info;
154 if (len & ~huge_page_mask(h))
159 if (flags & MAP_FIXED) {
160 if (prepare_hugepage_range(file, addr, len))
166 addr = ALIGN(addr, huge_page_size(h));
167 vma = find_vma(mm, addr);
168 if (TASK_SIZE - len >= addr &&
169 (!vma || addr + len <= vma->vm_start))
175 info.low_limit = TASK_UNMAPPED_BASE;
176 info.high_limit = TASK_SIZE;
177 info.align_mask = PAGE_MASK & ~huge_page_mask(h);
178 info.align_offset = 0;
179 return vm_unmapped_area(&info);
184 hugetlbfs_read_actor(struct page *page, unsigned long offset,
185 struct iov_iter *to, unsigned long size)
190 /* Find which 4k chunk and offset with in that chunk */
191 i = offset >> PAGE_CACHE_SHIFT;
192 offset = offset & ~PAGE_CACHE_MASK;
196 chunksize = PAGE_CACHE_SIZE;
199 if (chunksize > size)
201 n = copy_page_to_iter(&page[i], offset, chunksize, to);
213 * Support for read() - Find the page attached to f_mapping and copy out the
214 * data. Its *very* similar to do_generic_mapping_read(), we can't use that
215 * since it has PAGE_CACHE_SIZE assumptions.
217 static ssize_t hugetlbfs_read_iter(struct kiocb *iocb, struct iov_iter *to)
219 struct file *file = iocb->ki_filp;
220 struct hstate *h = hstate_file(file);
221 struct address_space *mapping = file->f_mapping;
222 struct inode *inode = mapping->host;
223 unsigned long index = iocb->ki_pos >> huge_page_shift(h);
224 unsigned long offset = iocb->ki_pos & ~huge_page_mask(h);
225 unsigned long end_index;
229 while (iov_iter_count(to)) {
233 /* nr is the maximum number of bytes to copy from this page */
234 nr = huge_page_size(h);
235 isize = i_size_read(inode);
238 end_index = (isize - 1) >> huge_page_shift(h);
239 if (index > end_index)
241 if (index == end_index) {
242 nr = ((isize - 1) & ~huge_page_mask(h)) + 1;
249 page = find_lock_page(mapping, index);
250 if (unlikely(page == NULL)) {
252 * We have a HOLE, zero out the user-buffer for the
253 * length of the hole or request.
255 copied = iov_iter_zero(nr, to);
260 * We have the page, copy it to user space buffer.
262 copied = hugetlbfs_read_actor(page, offset, to, nr);
263 page_cache_release(page);
267 if (copied != nr && iov_iter_count(to)) {
272 index += offset >> huge_page_shift(h);
273 offset &= ~huge_page_mask(h);
275 iocb->ki_pos = ((loff_t)index << huge_page_shift(h)) + offset;
279 static int hugetlbfs_write_begin(struct file *file,
280 struct address_space *mapping,
281 loff_t pos, unsigned len, unsigned flags,
282 struct page **pagep, void **fsdata)
287 static int hugetlbfs_write_end(struct file *file, struct address_space *mapping,
288 loff_t pos, unsigned len, unsigned copied,
289 struct page *page, void *fsdata)
295 static void truncate_huge_page(struct page *page)
297 ClearPageDirty(page);
298 ClearPageUptodate(page);
299 delete_from_page_cache(page);
302 static void truncate_hugepages(struct inode *inode, loff_t lstart)
304 struct hstate *h = hstate_inode(inode);
305 struct address_space *mapping = &inode->i_data;
306 const pgoff_t start = lstart >> huge_page_shift(h);
311 pagevec_init(&pvec, 0);
314 if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
321 for (i = 0; i < pagevec_count(&pvec); ++i) {
322 struct page *page = pvec.pages[i];
325 if (page->index > next)
328 truncate_huge_page(page);
332 huge_pagevec_release(&pvec);
334 BUG_ON(!lstart && mapping->nrpages);
335 hugetlb_unreserve_pages(inode, start, freed);
338 static void hugetlbfs_evict_inode(struct inode *inode)
340 struct resv_map *resv_map;
342 truncate_hugepages(inode, 0);
343 resv_map = (struct resv_map *)inode->i_mapping->private_data;
344 /* root inode doesn't have the resv_map, so we should check it */
346 resv_map_release(&resv_map->refs);
351 hugetlb_vmtruncate_list(struct rb_root *root, pgoff_t pgoff)
353 struct vm_area_struct *vma;
355 vma_interval_tree_foreach(vma, root, pgoff, ULONG_MAX) {
356 unsigned long v_offset;
359 * Can the expression below overflow on 32-bit arches?
360 * No, because the interval tree returns us only those vmas
361 * which overlap the truncated area starting at pgoff,
362 * and no vma on a 32-bit arch can span beyond the 4GB.
364 if (vma->vm_pgoff < pgoff)
365 v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT;
369 unmap_hugepage_range(vma, vma->vm_start + v_offset,
374 static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
377 struct address_space *mapping = inode->i_mapping;
378 struct hstate *h = hstate_inode(inode);
380 BUG_ON(offset & ~huge_page_mask(h));
381 pgoff = offset >> PAGE_SHIFT;
383 i_size_write(inode, offset);
384 i_mmap_lock_write(mapping);
385 if (!RB_EMPTY_ROOT(&mapping->i_mmap))
386 hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
387 i_mmap_unlock_write(mapping);
388 truncate_hugepages(inode, offset);
392 static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
394 struct inode *inode = dentry->d_inode;
395 struct hstate *h = hstate_inode(inode);
397 unsigned int ia_valid = attr->ia_valid;
401 error = inode_change_ok(inode, attr);
405 if (ia_valid & ATTR_SIZE) {
407 if (attr->ia_size & ~huge_page_mask(h))
409 error = hugetlb_vmtruncate(inode, attr->ia_size);
414 setattr_copy(inode, attr);
415 mark_inode_dirty(inode);
419 static struct inode *hugetlbfs_get_root(struct super_block *sb,
420 struct hugetlbfs_config *config)
424 inode = new_inode(sb);
426 struct hugetlbfs_inode_info *info;
427 inode->i_ino = get_next_ino();
428 inode->i_mode = S_IFDIR | config->mode;
429 inode->i_uid = config->uid;
430 inode->i_gid = config->gid;
431 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
432 info = HUGETLBFS_I(inode);
433 mpol_shared_policy_init(&info->policy, NULL);
434 inode->i_op = &hugetlbfs_dir_inode_operations;
435 inode->i_fop = &simple_dir_operations;
436 /* directory inodes start off with i_nlink == 2 (for "." entry) */
438 lockdep_annotate_inode_mutex_key(inode);
444 * Hugetlbfs is not reclaimable; therefore its i_mmap_rwsem will never
445 * be taken from reclaim -- unlike regular filesystems. This needs an
446 * annotation because huge_pmd_share() does an allocation under
449 static struct lock_class_key hugetlbfs_i_mmap_rwsem_key;
451 static struct inode *hugetlbfs_get_inode(struct super_block *sb,
453 umode_t mode, dev_t dev)
456 struct resv_map *resv_map;
458 resv_map = resv_map_alloc();
462 inode = new_inode(sb);
464 struct hugetlbfs_inode_info *info;
465 inode->i_ino = get_next_ino();
466 inode_init_owner(inode, dir, mode);
467 lockdep_set_class(&inode->i_mapping->i_mmap_rwsem,
468 &hugetlbfs_i_mmap_rwsem_key);
469 inode->i_mapping->a_ops = &hugetlbfs_aops;
470 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
471 inode->i_mapping->private_data = resv_map;
472 info = HUGETLBFS_I(inode);
474 * The policy is initialized here even if we are creating a
475 * private inode because initialization simply creates an
476 * an empty rb tree and calls spin_lock_init(), later when we
477 * call mpol_free_shared_policy() it will just return because
478 * the rb tree will still be empty.
480 mpol_shared_policy_init(&info->policy, NULL);
481 switch (mode & S_IFMT) {
483 init_special_inode(inode, mode, dev);
486 inode->i_op = &hugetlbfs_inode_operations;
487 inode->i_fop = &hugetlbfs_file_operations;
490 inode->i_op = &hugetlbfs_dir_inode_operations;
491 inode->i_fop = &simple_dir_operations;
493 /* directory inodes start off with i_nlink == 2 (for "." entry) */
497 inode->i_op = &page_symlink_inode_operations;
500 lockdep_annotate_inode_mutex_key(inode);
502 kref_put(&resv_map->refs, resv_map_release);
508 * File creation. Allocate an inode, and we're done..
510 static int hugetlbfs_mknod(struct inode *dir,
511 struct dentry *dentry, umode_t mode, dev_t dev)
516 inode = hugetlbfs_get_inode(dir->i_sb, dir, mode, dev);
518 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
519 d_instantiate(dentry, inode);
520 dget(dentry); /* Extra count - pin the dentry in core */
526 static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
528 int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0);
534 static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl)
536 return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0);
539 static int hugetlbfs_symlink(struct inode *dir,
540 struct dentry *dentry, const char *symname)
545 inode = hugetlbfs_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0);
547 int l = strlen(symname)+1;
548 error = page_symlink(inode, symname, l);
550 d_instantiate(dentry, inode);
555 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
561 * mark the head page dirty
563 static int hugetlbfs_set_page_dirty(struct page *page)
565 struct page *head = compound_head(page);
571 static int hugetlbfs_migrate_page(struct address_space *mapping,
572 struct page *newpage, struct page *page,
573 enum migrate_mode mode)
577 rc = migrate_huge_page_move_mapping(mapping, newpage, page);
578 if (rc != MIGRATEPAGE_SUCCESS)
580 migrate_page_copy(newpage, page);
582 return MIGRATEPAGE_SUCCESS;
585 static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
587 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
588 struct hstate *h = hstate_inode(dentry->d_inode);
590 buf->f_type = HUGETLBFS_MAGIC;
591 buf->f_bsize = huge_page_size(h);
593 spin_lock(&sbinfo->stat_lock);
594 /* If no limits set, just report 0 for max/free/used
595 * blocks, like simple_statfs() */
599 spin_lock(&sbinfo->spool->lock);
600 buf->f_blocks = sbinfo->spool->max_hpages;
601 free_pages = sbinfo->spool->max_hpages
602 - sbinfo->spool->used_hpages;
603 buf->f_bavail = buf->f_bfree = free_pages;
604 spin_unlock(&sbinfo->spool->lock);
605 buf->f_files = sbinfo->max_inodes;
606 buf->f_ffree = sbinfo->free_inodes;
608 spin_unlock(&sbinfo->stat_lock);
610 buf->f_namelen = NAME_MAX;
614 static void hugetlbfs_put_super(struct super_block *sb)
616 struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb);
619 sb->s_fs_info = NULL;
622 hugepage_put_subpool(sbi->spool);
628 static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo)
630 if (sbinfo->free_inodes >= 0) {
631 spin_lock(&sbinfo->stat_lock);
632 if (unlikely(!sbinfo->free_inodes)) {
633 spin_unlock(&sbinfo->stat_lock);
636 sbinfo->free_inodes--;
637 spin_unlock(&sbinfo->stat_lock);
643 static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
645 if (sbinfo->free_inodes >= 0) {
646 spin_lock(&sbinfo->stat_lock);
647 sbinfo->free_inodes++;
648 spin_unlock(&sbinfo->stat_lock);
653 static struct kmem_cache *hugetlbfs_inode_cachep;
655 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
657 struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
658 struct hugetlbfs_inode_info *p;
660 if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
662 p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL);
664 hugetlbfs_inc_free_inodes(sbinfo);
667 return &p->vfs_inode;
670 static void hugetlbfs_i_callback(struct rcu_head *head)
672 struct inode *inode = container_of(head, struct inode, i_rcu);
673 kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
676 static void hugetlbfs_destroy_inode(struct inode *inode)
678 hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
679 mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
680 call_rcu(&inode->i_rcu, hugetlbfs_i_callback);
683 static const struct address_space_operations hugetlbfs_aops = {
684 .write_begin = hugetlbfs_write_begin,
685 .write_end = hugetlbfs_write_end,
686 .set_page_dirty = hugetlbfs_set_page_dirty,
687 .migratepage = hugetlbfs_migrate_page,
691 static void init_once(void *foo)
693 struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
695 inode_init_once(&ei->vfs_inode);
698 const struct file_operations hugetlbfs_file_operations = {
699 .read_iter = hugetlbfs_read_iter,
700 .mmap = hugetlbfs_file_mmap,
702 .get_unmapped_area = hugetlb_get_unmapped_area,
703 .llseek = default_llseek,
706 static const struct inode_operations hugetlbfs_dir_inode_operations = {
707 .create = hugetlbfs_create,
708 .lookup = simple_lookup,
710 .unlink = simple_unlink,
711 .symlink = hugetlbfs_symlink,
712 .mkdir = hugetlbfs_mkdir,
713 .rmdir = simple_rmdir,
714 .mknod = hugetlbfs_mknod,
715 .rename = simple_rename,
716 .setattr = hugetlbfs_setattr,
719 static const struct inode_operations hugetlbfs_inode_operations = {
720 .setattr = hugetlbfs_setattr,
723 static const struct super_operations hugetlbfs_ops = {
724 .alloc_inode = hugetlbfs_alloc_inode,
725 .destroy_inode = hugetlbfs_destroy_inode,
726 .evict_inode = hugetlbfs_evict_inode,
727 .statfs = hugetlbfs_statfs,
728 .put_super = hugetlbfs_put_super,
729 .show_options = generic_show_options,
733 hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
736 substring_t args[MAX_OPT_ARGS];
738 unsigned long long size = 0;
739 enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = NO_SIZE;
744 while ((p = strsep(&options, ",")) != NULL) {
749 token = match_token(p, tokens, args);
752 if (match_int(&args[0], &option))
754 pconfig->uid = make_kuid(current_user_ns(), option);
755 if (!uid_valid(pconfig->uid))
760 if (match_int(&args[0], &option))
762 pconfig->gid = make_kgid(current_user_ns(), option);
763 if (!gid_valid(pconfig->gid))
768 if (match_octal(&args[0], &option))
770 pconfig->mode = option & 01777U;
774 /* memparse() will accept a K/M/G without a digit */
775 if (!isdigit(*args[0].from))
777 size = memparse(args[0].from, &rest);
780 setsize = SIZE_PERCENT;
785 /* memparse() will accept a K/M/G without a digit */
786 if (!isdigit(*args[0].from))
788 pconfig->nr_inodes = memparse(args[0].from, &rest);
793 ps = memparse(args[0].from, &rest);
794 pconfig->hstate = size_to_hstate(ps);
795 if (!pconfig->hstate) {
796 pr_err("Unsupported page size %lu MB\n",
804 pr_err("Bad mount option: \"%s\"\n", p);
810 /* Do size after hstate is set up */
811 if (setsize > NO_SIZE) {
812 struct hstate *h = pconfig->hstate;
813 if (setsize == SIZE_PERCENT) {
814 size <<= huge_page_shift(h);
815 size *= h->max_huge_pages;
818 pconfig->nr_blocks = (size >> huge_page_shift(h));
824 pr_err("Bad value '%s' for mount option '%s'\n", args[0].from, p);
829 hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
832 struct hugetlbfs_config config;
833 struct hugetlbfs_sb_info *sbinfo;
835 save_mount_options(sb, data);
837 config.nr_blocks = -1; /* No limit on size by default */
838 config.nr_inodes = -1; /* No limit on number of inodes by default */
839 config.uid = current_fsuid();
840 config.gid = current_fsgid();
842 config.hstate = &default_hstate;
843 ret = hugetlbfs_parse_options(data, &config);
847 sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL);
850 sb->s_fs_info = sbinfo;
851 sbinfo->hstate = config.hstate;
852 spin_lock_init(&sbinfo->stat_lock);
853 sbinfo->max_inodes = config.nr_inodes;
854 sbinfo->free_inodes = config.nr_inodes;
855 sbinfo->spool = NULL;
856 if (config.nr_blocks != -1) {
857 sbinfo->spool = hugepage_new_subpool(config.nr_blocks);
861 sb->s_maxbytes = MAX_LFS_FILESIZE;
862 sb->s_blocksize = huge_page_size(config.hstate);
863 sb->s_blocksize_bits = huge_page_shift(config.hstate);
864 sb->s_magic = HUGETLBFS_MAGIC;
865 sb->s_op = &hugetlbfs_ops;
867 sb->s_root = d_make_root(hugetlbfs_get_root(sb, &config));
872 kfree(sbinfo->spool);
877 static struct dentry *hugetlbfs_mount(struct file_system_type *fs_type,
878 int flags, const char *dev_name, void *data)
880 return mount_nodev(fs_type, flags, data, hugetlbfs_fill_super);
883 static struct file_system_type hugetlbfs_fs_type = {
885 .mount = hugetlbfs_mount,
886 .kill_sb = kill_litter_super,
888 MODULE_ALIAS_FS("hugetlbfs");
890 static struct vfsmount *hugetlbfs_vfsmount[HUGE_MAX_HSTATE];
892 static int can_do_hugetlb_shm(void)
895 shm_group = make_kgid(&init_user_ns, sysctl_hugetlb_shm_group);
896 return capable(CAP_IPC_LOCK) || in_group_p(shm_group);
899 static int get_hstate_idx(int page_size_log)
901 struct hstate *h = hstate_sizelog(page_size_log);
908 static const struct dentry_operations anon_ops = {
909 .d_dname = simple_dname
913 * Note that size should be aligned to proper hugepage size in caller side,
914 * otherwise hugetlb_reserve_pages reserves one less hugepages than intended.
916 struct file *hugetlb_file_setup(const char *name, size_t size,
917 vm_flags_t acctflag, struct user_struct **user,
918 int creat_flags, int page_size_log)
920 struct file *file = ERR_PTR(-ENOMEM);
923 struct super_block *sb;
924 struct qstr quick_string;
927 hstate_idx = get_hstate_idx(page_size_log);
929 return ERR_PTR(-ENODEV);
932 if (!hugetlbfs_vfsmount[hstate_idx])
933 return ERR_PTR(-ENOENT);
935 if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) {
936 *user = current_user();
937 if (user_shm_lock(size, *user)) {
939 pr_warn_once("%s (%d): Using mlock ulimits for SHM_HUGETLB is deprecated\n",
940 current->comm, current->pid);
941 task_unlock(current);
944 return ERR_PTR(-EPERM);
948 sb = hugetlbfs_vfsmount[hstate_idx]->mnt_sb;
949 quick_string.name = name;
950 quick_string.len = strlen(quick_string.name);
951 quick_string.hash = 0;
952 path.dentry = d_alloc_pseudo(sb, &quick_string);
956 d_set_d_op(path.dentry, &anon_ops);
957 path.mnt = mntget(hugetlbfs_vfsmount[hstate_idx]);
958 file = ERR_PTR(-ENOSPC);
959 inode = hugetlbfs_get_inode(sb, NULL, S_IFREG | S_IRWXUGO, 0);
963 file = ERR_PTR(-ENOMEM);
964 if (hugetlb_reserve_pages(inode, 0,
965 size >> huge_page_shift(hstate_inode(inode)), NULL,
969 d_instantiate(path.dentry, inode);
970 inode->i_size = size;
973 file = alloc_file(&path, FMODE_WRITE | FMODE_READ,
974 &hugetlbfs_file_operations);
976 goto out_dentry; /* inode is already attached */
986 user_shm_unlock(size, *user);
992 static int __init init_hugetlbfs_fs(void)
998 if (!hugepages_supported()) {
999 pr_info("disabling because there are no supported hugepage sizes\n");
1004 hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
1005 sizeof(struct hugetlbfs_inode_info),
1007 if (hugetlbfs_inode_cachep == NULL)
1010 error = register_filesystem(&hugetlbfs_fs_type);
1015 for_each_hstate(h) {
1017 unsigned ps_kb = 1U << (h->order + PAGE_SHIFT - 10);
1019 snprintf(buf, sizeof(buf), "pagesize=%uK", ps_kb);
1020 hugetlbfs_vfsmount[i] = kern_mount_data(&hugetlbfs_fs_type,
1023 if (IS_ERR(hugetlbfs_vfsmount[i])) {
1024 pr_err("Cannot mount internal hugetlbfs for "
1025 "page size %uK", ps_kb);
1026 error = PTR_ERR(hugetlbfs_vfsmount[i]);
1027 hugetlbfs_vfsmount[i] = NULL;
1031 /* Non default hstates are optional */
1032 if (!IS_ERR_OR_NULL(hugetlbfs_vfsmount[default_hstate_idx]))
1036 kmem_cache_destroy(hugetlbfs_inode_cachep);
1041 static void __exit exit_hugetlbfs_fs(void)
1048 * Make sure all delayed rcu free inodes are flushed before we
1052 kmem_cache_destroy(hugetlbfs_inode_cachep);
1055 kern_unmount(hugetlbfs_vfsmount[i++]);
1056 unregister_filesystem(&hugetlbfs_fs_type);
1059 module_init(init_hugetlbfs_fs)
1060 module_exit(exit_hugetlbfs_fs)
1062 MODULE_LICENSE("GPL");