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Commit | Line | Data |
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1da177e4 LT |
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/writeback.h> | |
17 | #include <linux/pagemap.h> | |
18 | #include <linux/highmem.h> | |
19 | #include <linux/init.h> | |
20 | #include <linux/string.h> | |
21 | #include <linux/backing-dev.h> | |
22 | #include <linux/hugetlb.h> | |
23 | #include <linux/pagevec.h> | |
24 | #include <linux/quotaops.h> | |
25 | #include <linux/slab.h> | |
26 | #include <linux/dnotify.h> | |
27 | #include <linux/statfs.h> | |
28 | #include <linux/security.h> | |
29 | ||
30 | #include <asm/uaccess.h> | |
31 | ||
32 | /* some random number */ | |
33 | #define HUGETLBFS_MAGIC 0x958458f6 | |
34 | ||
35 | static struct super_operations hugetlbfs_ops; | |
36 | static struct address_space_operations hugetlbfs_aops; | |
37 | struct file_operations hugetlbfs_file_operations; | |
38 | static struct inode_operations hugetlbfs_dir_inode_operations; | |
39 | static struct inode_operations hugetlbfs_inode_operations; | |
40 | ||
41 | static struct backing_dev_info hugetlbfs_backing_dev_info = { | |
42 | .ra_pages = 0, /* No readahead */ | |
43 | .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK, | |
44 | }; | |
45 | ||
46 | int sysctl_hugetlb_shm_group; | |
47 | ||
48 | static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma) | |
49 | { | |
50 | struct inode *inode = file->f_dentry->d_inode; | |
1da177e4 LT |
51 | loff_t len, vma_len; |
52 | int ret; | |
53 | ||
54 | if ((vma->vm_flags & (VM_MAYSHARE | VM_WRITE)) == VM_WRITE) | |
55 | return -EINVAL; | |
56 | ||
57 | if (vma->vm_pgoff & (HPAGE_SIZE / PAGE_SIZE - 1)) | |
58 | return -EINVAL; | |
59 | ||
60 | if (vma->vm_start & ~HPAGE_MASK) | |
61 | return -EINVAL; | |
62 | ||
63 | if (vma->vm_end & ~HPAGE_MASK) | |
64 | return -EINVAL; | |
65 | ||
66 | if (vma->vm_end - vma->vm_start < HPAGE_SIZE) | |
67 | return -EINVAL; | |
68 | ||
69 | vma_len = (loff_t)(vma->vm_end - vma->vm_start); | |
70 | ||
71 | down(&inode->i_sem); | |
72 | file_accessed(file); | |
73 | vma->vm_flags |= VM_HUGETLB | VM_RESERVED; | |
74 | vma->vm_ops = &hugetlb_vm_ops; | |
75 | ||
76 | ret = -ENOMEM; | |
77 | len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
78 | if (!(vma->vm_flags & VM_WRITE) && len > inode->i_size) | |
79 | goto out; | |
80 | ||
4c887265 AL |
81 | ret = 0; |
82 | hugetlb_prefault_arch_hook(vma->vm_mm); | |
1da177e4 LT |
83 | if (inode->i_size < len) |
84 | inode->i_size = len; | |
85 | out: | |
86 | up(&inode->i_sem); | |
87 | ||
88 | return ret; | |
89 | } | |
90 | ||
91 | /* | |
508034a3 | 92 | * Called under down_write(mmap_sem). |
1da177e4 LT |
93 | */ |
94 | ||
95 | #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA | |
96 | unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, | |
97 | unsigned long len, unsigned long pgoff, unsigned long flags); | |
98 | #else | |
99 | static unsigned long | |
100 | hugetlb_get_unmapped_area(struct file *file, unsigned long addr, | |
101 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
102 | { | |
103 | struct mm_struct *mm = current->mm; | |
104 | struct vm_area_struct *vma; | |
105 | unsigned long start_addr; | |
106 | ||
107 | if (len & ~HPAGE_MASK) | |
108 | return -EINVAL; | |
109 | if (len > TASK_SIZE) | |
110 | return -ENOMEM; | |
111 | ||
112 | if (addr) { | |
113 | addr = ALIGN(addr, HPAGE_SIZE); | |
114 | vma = find_vma(mm, addr); | |
115 | if (TASK_SIZE - len >= addr && | |
116 | (!vma || addr + len <= vma->vm_start)) | |
117 | return addr; | |
118 | } | |
119 | ||
120 | start_addr = mm->free_area_cache; | |
121 | ||
1363c3cd WW |
122 | if (len <= mm->cached_hole_size) |
123 | start_addr = TASK_UNMAPPED_BASE; | |
124 | ||
1da177e4 LT |
125 | full_search: |
126 | addr = ALIGN(start_addr, HPAGE_SIZE); | |
127 | ||
128 | for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { | |
129 | /* At this point: (!vma || addr < vma->vm_end). */ | |
130 | if (TASK_SIZE - len < addr) { | |
131 | /* | |
132 | * Start a new search - just in case we missed | |
133 | * some holes. | |
134 | */ | |
135 | if (start_addr != TASK_UNMAPPED_BASE) { | |
136 | start_addr = TASK_UNMAPPED_BASE; | |
137 | goto full_search; | |
138 | } | |
139 | return -ENOMEM; | |
140 | } | |
141 | ||
142 | if (!vma || addr + len <= vma->vm_start) | |
143 | return addr; | |
144 | addr = ALIGN(vma->vm_end, HPAGE_SIZE); | |
145 | } | |
146 | } | |
147 | #endif | |
148 | ||
149 | /* | |
150 | * Read a page. Again trivial. If it didn't already exist | |
151 | * in the page cache, it is zero-filled. | |
152 | */ | |
153 | static int hugetlbfs_readpage(struct file *file, struct page * page) | |
154 | { | |
155 | unlock_page(page); | |
156 | return -EINVAL; | |
157 | } | |
158 | ||
159 | static int hugetlbfs_prepare_write(struct file *file, | |
160 | struct page *page, unsigned offset, unsigned to) | |
161 | { | |
162 | return -EINVAL; | |
163 | } | |
164 | ||
165 | static int hugetlbfs_commit_write(struct file *file, | |
166 | struct page *page, unsigned offset, unsigned to) | |
167 | { | |
168 | return -EINVAL; | |
169 | } | |
170 | ||
171 | static void huge_pagevec_release(struct pagevec *pvec) | |
172 | { | |
173 | int i; | |
174 | ||
175 | for (i = 0; i < pagevec_count(pvec); ++i) | |
176 | put_page(pvec->pages[i]); | |
177 | ||
178 | pagevec_reinit(pvec); | |
179 | } | |
180 | ||
181 | static void truncate_huge_page(struct page *page) | |
182 | { | |
183 | clear_page_dirty(page); | |
184 | ClearPageUptodate(page); | |
185 | remove_from_page_cache(page); | |
186 | put_page(page); | |
187 | } | |
188 | ||
189 | static void truncate_hugepages(struct address_space *mapping, loff_t lstart) | |
190 | { | |
191 | const pgoff_t start = lstart >> HPAGE_SHIFT; | |
192 | struct pagevec pvec; | |
193 | pgoff_t next; | |
194 | int i; | |
195 | ||
196 | pagevec_init(&pvec, 0); | |
197 | next = start; | |
198 | while (1) { | |
199 | if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) { | |
200 | if (next == start) | |
201 | break; | |
202 | next = start; | |
203 | continue; | |
204 | } | |
205 | ||
206 | for (i = 0; i < pagevec_count(&pvec); ++i) { | |
207 | struct page *page = pvec.pages[i]; | |
208 | ||
209 | lock_page(page); | |
210 | if (page->index > next) | |
211 | next = page->index; | |
212 | ++next; | |
213 | truncate_huge_page(page); | |
214 | unlock_page(page); | |
215 | hugetlb_put_quota(mapping); | |
216 | } | |
217 | huge_pagevec_release(&pvec); | |
218 | } | |
219 | BUG_ON(!lstart && mapping->nrpages); | |
220 | } | |
221 | ||
222 | static void hugetlbfs_delete_inode(struct inode *inode) | |
223 | { | |
149f4211 CH |
224 | if (inode->i_data.nrpages) |
225 | truncate_hugepages(&inode->i_data, 0); | |
226 | clear_inode(inode); | |
227 | } | |
228 | ||
1da177e4 LT |
229 | static void hugetlbfs_forget_inode(struct inode *inode) |
230 | { | |
0b1533f6 CH |
231 | struct super_block *sb = inode->i_sb; |
232 | ||
233 | if (!hlist_unhashed(&inode->i_hash)) { | |
234 | if (!(inode->i_state & (I_DIRTY|I_LOCK))) | |
235 | list_move(&inode->i_list, &inode_unused); | |
236 | inodes_stat.nr_unused++; | |
237 | if (!sb || (sb->s_flags & MS_ACTIVE)) { | |
238 | spin_unlock(&inode_lock); | |
239 | return; | |
240 | } | |
241 | inode->i_state |= I_WILL_FREE; | |
1da177e4 | 242 | spin_unlock(&inode_lock); |
0b1533f6 CH |
243 | /* |
244 | * write_inode_now is a noop as we set BDI_CAP_NO_WRITEBACK | |
245 | * in our backing_dev_info. | |
246 | */ | |
247 | write_inode_now(inode, 1); | |
248 | spin_lock(&inode_lock); | |
249 | inode->i_state &= ~I_WILL_FREE; | |
250 | inodes_stat.nr_unused--; | |
251 | hlist_del_init(&inode->i_hash); | |
1da177e4 | 252 | } |
1da177e4 LT |
253 | list_del_init(&inode->i_list); |
254 | list_del_init(&inode->i_sb_list); | |
255 | inode->i_state |= I_FREEING; | |
256 | inodes_stat.nr_inodes--; | |
257 | spin_unlock(&inode_lock); | |
258 | if (inode->i_data.nrpages) | |
259 | truncate_hugepages(&inode->i_data, 0); | |
1da177e4 LT |
260 | clear_inode(inode); |
261 | destroy_inode(inode); | |
262 | } | |
263 | ||
264 | static void hugetlbfs_drop_inode(struct inode *inode) | |
265 | { | |
266 | if (!inode->i_nlink) | |
6b09b9df | 267 | generic_delete_inode(inode); |
1da177e4 LT |
268 | else |
269 | hugetlbfs_forget_inode(inode); | |
270 | } | |
271 | ||
272 | /* | |
273 | * h_pgoff is in HPAGE_SIZE units. | |
274 | * vma->vm_pgoff is in PAGE_SIZE units. | |
275 | */ | |
276 | static inline void | |
277 | hugetlb_vmtruncate_list(struct prio_tree_root *root, unsigned long h_pgoff) | |
278 | { | |
279 | struct vm_area_struct *vma; | |
280 | struct prio_tree_iter iter; | |
281 | ||
282 | vma_prio_tree_foreach(vma, &iter, root, h_pgoff, ULONG_MAX) { | |
283 | unsigned long h_vm_pgoff; | |
1da177e4 LT |
284 | unsigned long v_offset; |
285 | ||
286 | h_vm_pgoff = vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT); | |
287 | v_offset = (h_pgoff - h_vm_pgoff) << HPAGE_SHIFT; | |
288 | /* | |
289 | * Is this VMA fully outside the truncation point? | |
290 | */ | |
291 | if (h_vm_pgoff >= h_pgoff) | |
292 | v_offset = 0; | |
293 | ||
508034a3 HD |
294 | unmap_hugepage_range(vma, |
295 | vma->vm_start + v_offset, vma->vm_end); | |
1da177e4 LT |
296 | } |
297 | } | |
298 | ||
299 | /* | |
300 | * Expanding truncates are not allowed. | |
301 | */ | |
302 | static int hugetlb_vmtruncate(struct inode *inode, loff_t offset) | |
303 | { | |
304 | unsigned long pgoff; | |
305 | struct address_space *mapping = inode->i_mapping; | |
306 | ||
307 | if (offset > inode->i_size) | |
308 | return -EINVAL; | |
309 | ||
310 | BUG_ON(offset & ~HPAGE_MASK); | |
311 | pgoff = offset >> HPAGE_SHIFT; | |
312 | ||
313 | inode->i_size = offset; | |
314 | spin_lock(&mapping->i_mmap_lock); | |
315 | if (!prio_tree_empty(&mapping->i_mmap)) | |
316 | hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff); | |
317 | spin_unlock(&mapping->i_mmap_lock); | |
318 | truncate_hugepages(mapping, offset); | |
319 | return 0; | |
320 | } | |
321 | ||
322 | static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr) | |
323 | { | |
324 | struct inode *inode = dentry->d_inode; | |
325 | int error; | |
326 | unsigned int ia_valid = attr->ia_valid; | |
327 | ||
328 | BUG_ON(!inode); | |
329 | ||
330 | error = inode_change_ok(inode, attr); | |
331 | if (error) | |
332 | goto out; | |
333 | ||
334 | if (ia_valid & ATTR_SIZE) { | |
335 | error = -EINVAL; | |
336 | if (!(attr->ia_size & ~HPAGE_MASK)) | |
337 | error = hugetlb_vmtruncate(inode, attr->ia_size); | |
338 | if (error) | |
339 | goto out; | |
340 | attr->ia_valid &= ~ATTR_SIZE; | |
341 | } | |
342 | error = inode_setattr(inode, attr); | |
343 | out: | |
344 | return error; | |
345 | } | |
346 | ||
347 | static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid, | |
348 | gid_t gid, int mode, dev_t dev) | |
349 | { | |
350 | struct inode *inode; | |
1da177e4 LT |
351 | |
352 | inode = new_inode(sb); | |
353 | if (inode) { | |
354 | struct hugetlbfs_inode_info *info; | |
355 | inode->i_mode = mode; | |
356 | inode->i_uid = uid; | |
357 | inode->i_gid = gid; | |
358 | inode->i_blksize = HPAGE_SIZE; | |
359 | inode->i_blocks = 0; | |
360 | inode->i_mapping->a_ops = &hugetlbfs_aops; | |
361 | inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info; | |
362 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
363 | info = HUGETLBFS_I(inode); | |
364 | mpol_shared_policy_init(&info->policy); | |
365 | switch (mode & S_IFMT) { | |
366 | default: | |
367 | init_special_inode(inode, mode, dev); | |
368 | break; | |
369 | case S_IFREG: | |
370 | inode->i_op = &hugetlbfs_inode_operations; | |
371 | inode->i_fop = &hugetlbfs_file_operations; | |
372 | break; | |
373 | case S_IFDIR: | |
374 | inode->i_op = &hugetlbfs_dir_inode_operations; | |
375 | inode->i_fop = &simple_dir_operations; | |
376 | ||
377 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ | |
378 | inode->i_nlink++; | |
379 | break; | |
380 | case S_IFLNK: | |
381 | inode->i_op = &page_symlink_inode_operations; | |
382 | break; | |
383 | } | |
384 | } | |
385 | return inode; | |
386 | } | |
387 | ||
388 | /* | |
389 | * File creation. Allocate an inode, and we're done.. | |
390 | */ | |
391 | static int hugetlbfs_mknod(struct inode *dir, | |
392 | struct dentry *dentry, int mode, dev_t dev) | |
393 | { | |
394 | struct inode *inode; | |
395 | int error = -ENOSPC; | |
396 | gid_t gid; | |
397 | ||
398 | if (dir->i_mode & S_ISGID) { | |
399 | gid = dir->i_gid; | |
400 | if (S_ISDIR(mode)) | |
401 | mode |= S_ISGID; | |
402 | } else { | |
403 | gid = current->fsgid; | |
404 | } | |
405 | inode = hugetlbfs_get_inode(dir->i_sb, current->fsuid, gid, mode, dev); | |
406 | if (inode) { | |
407 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
408 | d_instantiate(dentry, inode); | |
409 | dget(dentry); /* Extra count - pin the dentry in core */ | |
410 | error = 0; | |
411 | } | |
412 | return error; | |
413 | } | |
414 | ||
415 | static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
416 | { | |
417 | int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0); | |
418 | if (!retval) | |
419 | dir->i_nlink++; | |
420 | return retval; | |
421 | } | |
422 | ||
423 | static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) | |
424 | { | |
425 | return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0); | |
426 | } | |
427 | ||
428 | static int hugetlbfs_symlink(struct inode *dir, | |
429 | struct dentry *dentry, const char *symname) | |
430 | { | |
431 | struct inode *inode; | |
432 | int error = -ENOSPC; | |
433 | gid_t gid; | |
434 | ||
435 | if (dir->i_mode & S_ISGID) | |
436 | gid = dir->i_gid; | |
437 | else | |
438 | gid = current->fsgid; | |
439 | ||
440 | inode = hugetlbfs_get_inode(dir->i_sb, current->fsuid, | |
441 | gid, S_IFLNK|S_IRWXUGO, 0); | |
442 | if (inode) { | |
443 | int l = strlen(symname)+1; | |
444 | error = page_symlink(inode, symname, l); | |
445 | if (!error) { | |
446 | d_instantiate(dentry, inode); | |
447 | dget(dentry); | |
448 | } else | |
449 | iput(inode); | |
450 | } | |
451 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
452 | ||
453 | return error; | |
454 | } | |
455 | ||
456 | /* | |
457 | * For direct-IO reads into hugetlb pages | |
458 | */ | |
459 | static int hugetlbfs_set_page_dirty(struct page *page) | |
460 | { | |
461 | return 0; | |
462 | } | |
463 | ||
464 | static int hugetlbfs_statfs(struct super_block *sb, struct kstatfs *buf) | |
465 | { | |
466 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); | |
467 | ||
468 | buf->f_type = HUGETLBFS_MAGIC; | |
469 | buf->f_bsize = HPAGE_SIZE; | |
470 | if (sbinfo) { | |
471 | spin_lock(&sbinfo->stat_lock); | |
472 | buf->f_blocks = sbinfo->max_blocks; | |
473 | buf->f_bavail = buf->f_bfree = sbinfo->free_blocks; | |
474 | buf->f_files = sbinfo->max_inodes; | |
475 | buf->f_ffree = sbinfo->free_inodes; | |
476 | spin_unlock(&sbinfo->stat_lock); | |
477 | } | |
478 | buf->f_namelen = NAME_MAX; | |
479 | return 0; | |
480 | } | |
481 | ||
482 | static void hugetlbfs_put_super(struct super_block *sb) | |
483 | { | |
484 | struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb); | |
485 | ||
486 | if (sbi) { | |
487 | sb->s_fs_info = NULL; | |
488 | kfree(sbi); | |
489 | } | |
490 | } | |
491 | ||
96527980 CH |
492 | static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo) |
493 | { | |
494 | if (sbinfo->free_inodes >= 0) { | |
495 | spin_lock(&sbinfo->stat_lock); | |
496 | if (unlikely(!sbinfo->free_inodes)) { | |
497 | spin_unlock(&sbinfo->stat_lock); | |
498 | return 0; | |
499 | } | |
500 | sbinfo->free_inodes--; | |
501 | spin_unlock(&sbinfo->stat_lock); | |
502 | } | |
503 | ||
504 | return 1; | |
505 | } | |
506 | ||
507 | static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo) | |
508 | { | |
509 | if (sbinfo->free_inodes >= 0) { | |
510 | spin_lock(&sbinfo->stat_lock); | |
511 | sbinfo->free_inodes++; | |
512 | spin_unlock(&sbinfo->stat_lock); | |
513 | } | |
514 | } | |
515 | ||
516 | ||
1da177e4 LT |
517 | static kmem_cache_t *hugetlbfs_inode_cachep; |
518 | ||
519 | static struct inode *hugetlbfs_alloc_inode(struct super_block *sb) | |
520 | { | |
96527980 | 521 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); |
1da177e4 LT |
522 | struct hugetlbfs_inode_info *p; |
523 | ||
96527980 CH |
524 | if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo))) |
525 | return NULL; | |
1da177e4 | 526 | p = kmem_cache_alloc(hugetlbfs_inode_cachep, SLAB_KERNEL); |
96527980 CH |
527 | if (unlikely(!p)) { |
528 | hugetlbfs_inc_free_inodes(sbinfo); | |
1da177e4 | 529 | return NULL; |
96527980 | 530 | } |
1da177e4 LT |
531 | return &p->vfs_inode; |
532 | } | |
533 | ||
1da177e4 LT |
534 | static void hugetlbfs_destroy_inode(struct inode *inode) |
535 | { | |
96527980 | 536 | hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb)); |
1da177e4 LT |
537 | mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy); |
538 | kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode)); | |
539 | } | |
540 | ||
541 | static struct address_space_operations hugetlbfs_aops = { | |
542 | .readpage = hugetlbfs_readpage, | |
543 | .prepare_write = hugetlbfs_prepare_write, | |
544 | .commit_write = hugetlbfs_commit_write, | |
545 | .set_page_dirty = hugetlbfs_set_page_dirty, | |
546 | }; | |
547 | ||
96527980 CH |
548 | |
549 | static void init_once(void *foo, kmem_cache_t *cachep, unsigned long flags) | |
550 | { | |
551 | struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo; | |
552 | ||
553 | if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == | |
554 | SLAB_CTOR_CONSTRUCTOR) | |
555 | inode_init_once(&ei->vfs_inode); | |
556 | } | |
557 | ||
1da177e4 LT |
558 | struct file_operations hugetlbfs_file_operations = { |
559 | .mmap = hugetlbfs_file_mmap, | |
560 | .fsync = simple_sync_file, | |
561 | .get_unmapped_area = hugetlb_get_unmapped_area, | |
562 | }; | |
563 | ||
564 | static struct inode_operations hugetlbfs_dir_inode_operations = { | |
565 | .create = hugetlbfs_create, | |
566 | .lookup = simple_lookup, | |
567 | .link = simple_link, | |
568 | .unlink = simple_unlink, | |
569 | .symlink = hugetlbfs_symlink, | |
570 | .mkdir = hugetlbfs_mkdir, | |
571 | .rmdir = simple_rmdir, | |
572 | .mknod = hugetlbfs_mknod, | |
573 | .rename = simple_rename, | |
574 | .setattr = hugetlbfs_setattr, | |
575 | }; | |
576 | ||
577 | static struct inode_operations hugetlbfs_inode_operations = { | |
578 | .setattr = hugetlbfs_setattr, | |
579 | }; | |
580 | ||
581 | static struct super_operations hugetlbfs_ops = { | |
582 | .alloc_inode = hugetlbfs_alloc_inode, | |
583 | .destroy_inode = hugetlbfs_destroy_inode, | |
584 | .statfs = hugetlbfs_statfs, | |
149f4211 | 585 | .delete_inode = hugetlbfs_delete_inode, |
1da177e4 LT |
586 | .drop_inode = hugetlbfs_drop_inode, |
587 | .put_super = hugetlbfs_put_super, | |
588 | }; | |
589 | ||
590 | static int | |
591 | hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig) | |
592 | { | |
593 | char *opt, *value, *rest; | |
594 | ||
595 | if (!options) | |
596 | return 0; | |
597 | while ((opt = strsep(&options, ",")) != NULL) { | |
598 | if (!*opt) | |
599 | continue; | |
600 | ||
601 | value = strchr(opt, '='); | |
602 | if (!value || !*value) | |
603 | return -EINVAL; | |
604 | else | |
605 | *value++ = '\0'; | |
606 | ||
607 | if (!strcmp(opt, "uid")) | |
608 | pconfig->uid = simple_strtoul(value, &value, 0); | |
609 | else if (!strcmp(opt, "gid")) | |
610 | pconfig->gid = simple_strtoul(value, &value, 0); | |
611 | else if (!strcmp(opt, "mode")) | |
612 | pconfig->mode = simple_strtoul(value,&value,0) & 0777U; | |
613 | else if (!strcmp(opt, "size")) { | |
614 | unsigned long long size = memparse(value, &rest); | |
615 | if (*rest == '%') { | |
616 | size <<= HPAGE_SHIFT; | |
617 | size *= max_huge_pages; | |
618 | do_div(size, 100); | |
619 | rest++; | |
620 | } | |
621 | size &= HPAGE_MASK; | |
622 | pconfig->nr_blocks = (size >> HPAGE_SHIFT); | |
623 | value = rest; | |
624 | } else if (!strcmp(opt,"nr_inodes")) { | |
625 | pconfig->nr_inodes = memparse(value, &rest); | |
626 | value = rest; | |
627 | } else | |
628 | return -EINVAL; | |
629 | ||
630 | if (*value) | |
631 | return -EINVAL; | |
632 | } | |
633 | return 0; | |
634 | } | |
635 | ||
636 | static int | |
637 | hugetlbfs_fill_super(struct super_block *sb, void *data, int silent) | |
638 | { | |
639 | struct inode * inode; | |
640 | struct dentry * root; | |
641 | int ret; | |
642 | struct hugetlbfs_config config; | |
643 | struct hugetlbfs_sb_info *sbinfo; | |
644 | ||
645 | config.nr_blocks = -1; /* No limit on size by default */ | |
646 | config.nr_inodes = -1; /* No limit on number of inodes by default */ | |
647 | config.uid = current->fsuid; | |
648 | config.gid = current->fsgid; | |
649 | config.mode = 0755; | |
650 | ret = hugetlbfs_parse_options(data, &config); | |
651 | ||
652 | if (ret) | |
653 | return ret; | |
654 | ||
655 | sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL); | |
656 | if (!sbinfo) | |
657 | return -ENOMEM; | |
658 | sb->s_fs_info = sbinfo; | |
659 | spin_lock_init(&sbinfo->stat_lock); | |
660 | sbinfo->max_blocks = config.nr_blocks; | |
661 | sbinfo->free_blocks = config.nr_blocks; | |
662 | sbinfo->max_inodes = config.nr_inodes; | |
663 | sbinfo->free_inodes = config.nr_inodes; | |
664 | sb->s_maxbytes = MAX_LFS_FILESIZE; | |
665 | sb->s_blocksize = HPAGE_SIZE; | |
666 | sb->s_blocksize_bits = HPAGE_SHIFT; | |
667 | sb->s_magic = HUGETLBFS_MAGIC; | |
668 | sb->s_op = &hugetlbfs_ops; | |
669 | sb->s_time_gran = 1; | |
670 | inode = hugetlbfs_get_inode(sb, config.uid, config.gid, | |
671 | S_IFDIR | config.mode, 0); | |
672 | if (!inode) | |
673 | goto out_free; | |
674 | ||
675 | root = d_alloc_root(inode); | |
676 | if (!root) { | |
677 | iput(inode); | |
678 | goto out_free; | |
679 | } | |
680 | sb->s_root = root; | |
681 | return 0; | |
682 | out_free: | |
683 | kfree(sbinfo); | |
684 | return -ENOMEM; | |
685 | } | |
686 | ||
687 | int hugetlb_get_quota(struct address_space *mapping) | |
688 | { | |
689 | int ret = 0; | |
690 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); | |
691 | ||
692 | if (sbinfo->free_blocks > -1) { | |
693 | spin_lock(&sbinfo->stat_lock); | |
694 | if (sbinfo->free_blocks > 0) | |
695 | sbinfo->free_blocks--; | |
696 | else | |
697 | ret = -ENOMEM; | |
698 | spin_unlock(&sbinfo->stat_lock); | |
699 | } | |
700 | ||
701 | return ret; | |
702 | } | |
703 | ||
704 | void hugetlb_put_quota(struct address_space *mapping) | |
705 | { | |
706 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); | |
707 | ||
708 | if (sbinfo->free_blocks > -1) { | |
709 | spin_lock(&sbinfo->stat_lock); | |
710 | sbinfo->free_blocks++; | |
711 | spin_unlock(&sbinfo->stat_lock); | |
712 | } | |
713 | } | |
714 | ||
715 | static struct super_block *hugetlbfs_get_sb(struct file_system_type *fs_type, | |
716 | int flags, const char *dev_name, void *data) | |
717 | { | |
718 | return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super); | |
719 | } | |
720 | ||
721 | static struct file_system_type hugetlbfs_fs_type = { | |
722 | .name = "hugetlbfs", | |
723 | .get_sb = hugetlbfs_get_sb, | |
724 | .kill_sb = kill_litter_super, | |
725 | }; | |
726 | ||
727 | static struct vfsmount *hugetlbfs_vfsmount; | |
728 | ||
729 | /* | |
730 | * Return the next identifier for a shm file | |
731 | */ | |
732 | static unsigned long hugetlbfs_counter(void) | |
733 | { | |
734 | static DEFINE_SPINLOCK(lock); | |
735 | static unsigned long counter; | |
736 | unsigned long ret; | |
737 | ||
738 | spin_lock(&lock); | |
739 | ret = ++counter; | |
740 | spin_unlock(&lock); | |
741 | return ret; | |
742 | } | |
743 | ||
744 | static int can_do_hugetlb_shm(void) | |
745 | { | |
746 | return likely(capable(CAP_IPC_LOCK) || | |
747 | in_group_p(sysctl_hugetlb_shm_group) || | |
748 | can_do_mlock()); | |
749 | } | |
750 | ||
751 | struct file *hugetlb_zero_setup(size_t size) | |
752 | { | |
753 | int error = -ENOMEM; | |
754 | struct file *file; | |
755 | struct inode *inode; | |
756 | struct dentry *dentry, *root; | |
757 | struct qstr quick_string; | |
758 | char buf[16]; | |
759 | ||
760 | if (!can_do_hugetlb_shm()) | |
761 | return ERR_PTR(-EPERM); | |
762 | ||
763 | if (!is_hugepage_mem_enough(size)) | |
764 | return ERR_PTR(-ENOMEM); | |
765 | ||
766 | if (!user_shm_lock(size, current->user)) | |
767 | return ERR_PTR(-ENOMEM); | |
768 | ||
769 | root = hugetlbfs_vfsmount->mnt_root; | |
770 | snprintf(buf, 16, "%lu", hugetlbfs_counter()); | |
771 | quick_string.name = buf; | |
772 | quick_string.len = strlen(quick_string.name); | |
773 | quick_string.hash = 0; | |
774 | dentry = d_alloc(root, &quick_string); | |
775 | if (!dentry) | |
776 | goto out_shm_unlock; | |
777 | ||
778 | error = -ENFILE; | |
779 | file = get_empty_filp(); | |
780 | if (!file) | |
781 | goto out_dentry; | |
782 | ||
783 | error = -ENOSPC; | |
784 | inode = hugetlbfs_get_inode(root->d_sb, current->fsuid, | |
785 | current->fsgid, S_IFREG | S_IRWXUGO, 0); | |
786 | if (!inode) | |
787 | goto out_file; | |
788 | ||
789 | d_instantiate(dentry, inode); | |
790 | inode->i_size = size; | |
791 | inode->i_nlink = 0; | |
792 | file->f_vfsmnt = mntget(hugetlbfs_vfsmount); | |
793 | file->f_dentry = dentry; | |
794 | file->f_mapping = inode->i_mapping; | |
795 | file->f_op = &hugetlbfs_file_operations; | |
796 | file->f_mode = FMODE_WRITE | FMODE_READ; | |
797 | return file; | |
798 | ||
799 | out_file: | |
800 | put_filp(file); | |
801 | out_dentry: | |
802 | dput(dentry); | |
803 | out_shm_unlock: | |
804 | user_shm_unlock(size, current->user); | |
805 | return ERR_PTR(error); | |
806 | } | |
807 | ||
808 | static int __init init_hugetlbfs_fs(void) | |
809 | { | |
810 | int error; | |
811 | struct vfsmount *vfsmount; | |
812 | ||
813 | hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache", | |
814 | sizeof(struct hugetlbfs_inode_info), | |
815 | 0, 0, init_once, NULL); | |
816 | if (hugetlbfs_inode_cachep == NULL) | |
817 | return -ENOMEM; | |
818 | ||
819 | error = register_filesystem(&hugetlbfs_fs_type); | |
820 | if (error) | |
821 | goto out; | |
822 | ||
823 | vfsmount = kern_mount(&hugetlbfs_fs_type); | |
824 | ||
825 | if (!IS_ERR(vfsmount)) { | |
826 | hugetlbfs_vfsmount = vfsmount; | |
827 | return 0; | |
828 | } | |
829 | ||
830 | error = PTR_ERR(vfsmount); | |
831 | ||
832 | out: | |
833 | if (error) | |
834 | kmem_cache_destroy(hugetlbfs_inode_cachep); | |
835 | return error; | |
836 | } | |
837 | ||
838 | static void __exit exit_hugetlbfs_fs(void) | |
839 | { | |
840 | kmem_cache_destroy(hugetlbfs_inode_cachep); | |
841 | unregister_filesystem(&hugetlbfs_fs_type); | |
842 | } | |
843 | ||
844 | module_init(init_hugetlbfs_fs) | |
845 | module_exit(exit_hugetlbfs_fs) | |
846 | ||
847 | MODULE_LICENSE("GPL"); |