Commit | Line | Data |
---|---|---|
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 | ||
2e9b367c AL |
48 | static void huge_pagevec_release(struct pagevec *pvec) |
49 | { | |
50 | int i; | |
51 | ||
52 | for (i = 0; i < pagevec_count(pvec); ++i) | |
53 | put_page(pvec->pages[i]); | |
54 | ||
55 | pagevec_reinit(pvec); | |
56 | } | |
57 | ||
58 | /* | |
59 | * huge_pages_needed tries to determine the number of new huge pages that | |
60 | * will be required to fully populate this VMA. This will be equal to | |
61 | * the size of the VMA in huge pages minus the number of huge pages | |
62 | * (covered by this VMA) that are found in the page cache. | |
63 | * | |
64 | * Result is in bytes to be compatible with is_hugepage_mem_enough() | |
65 | */ | |
8d3d81cf | 66 | static unsigned long |
2e9b367c AL |
67 | huge_pages_needed(struct address_space *mapping, struct vm_area_struct *vma) |
68 | { | |
69 | int i; | |
70 | struct pagevec pvec; | |
71 | unsigned long start = vma->vm_start; | |
72 | unsigned long end = vma->vm_end; | |
73 | unsigned long hugepages = (end - start) >> HPAGE_SHIFT; | |
74 | pgoff_t next = vma->vm_pgoff; | |
75 | pgoff_t endpg = next + ((end - start) >> PAGE_SHIFT); | |
76 | ||
77 | pagevec_init(&pvec, 0); | |
78 | while (next < endpg) { | |
79 | if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) | |
80 | break; | |
81 | for (i = 0; i < pagevec_count(&pvec); i++) { | |
82 | struct page *page = pvec.pages[i]; | |
83 | if (page->index > next) | |
84 | next = page->index; | |
85 | if (page->index >= endpg) | |
86 | break; | |
87 | next++; | |
88 | hugepages--; | |
89 | } | |
90 | huge_pagevec_release(&pvec); | |
91 | } | |
92 | return hugepages << HPAGE_SHIFT; | |
93 | } | |
94 | ||
1da177e4 LT |
95 | static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma) |
96 | { | |
97 | struct inode *inode = file->f_dentry->d_inode; | |
2e9b367c AL |
98 | struct address_space *mapping = inode->i_mapping; |
99 | unsigned long bytes; | |
1da177e4 LT |
100 | loff_t len, vma_len; |
101 | int ret; | |
102 | ||
1da177e4 LT |
103 | if (vma->vm_pgoff & (HPAGE_SIZE / PAGE_SIZE - 1)) |
104 | return -EINVAL; | |
105 | ||
106 | if (vma->vm_start & ~HPAGE_MASK) | |
107 | return -EINVAL; | |
108 | ||
109 | if (vma->vm_end & ~HPAGE_MASK) | |
110 | return -EINVAL; | |
111 | ||
112 | if (vma->vm_end - vma->vm_start < HPAGE_SIZE) | |
113 | return -EINVAL; | |
114 | ||
2e9b367c AL |
115 | bytes = huge_pages_needed(mapping, vma); |
116 | if (!is_hugepage_mem_enough(bytes)) | |
117 | return -ENOMEM; | |
118 | ||
1da177e4 LT |
119 | vma_len = (loff_t)(vma->vm_end - vma->vm_start); |
120 | ||
121 | down(&inode->i_sem); | |
122 | file_accessed(file); | |
123 | vma->vm_flags |= VM_HUGETLB | VM_RESERVED; | |
124 | vma->vm_ops = &hugetlb_vm_ops; | |
125 | ||
126 | ret = -ENOMEM; | |
127 | len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
128 | if (!(vma->vm_flags & VM_WRITE) && len > inode->i_size) | |
129 | goto out; | |
130 | ||
4c887265 AL |
131 | ret = 0; |
132 | hugetlb_prefault_arch_hook(vma->vm_mm); | |
1da177e4 LT |
133 | if (inode->i_size < len) |
134 | inode->i_size = len; | |
135 | out: | |
136 | up(&inode->i_sem); | |
137 | ||
138 | return ret; | |
139 | } | |
140 | ||
141 | /* | |
508034a3 | 142 | * Called under down_write(mmap_sem). |
1da177e4 LT |
143 | */ |
144 | ||
145 | #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA | |
146 | unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, | |
147 | unsigned long len, unsigned long pgoff, unsigned long flags); | |
148 | #else | |
149 | static unsigned long | |
150 | hugetlb_get_unmapped_area(struct file *file, unsigned long addr, | |
151 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
152 | { | |
153 | struct mm_struct *mm = current->mm; | |
154 | struct vm_area_struct *vma; | |
155 | unsigned long start_addr; | |
156 | ||
157 | if (len & ~HPAGE_MASK) | |
158 | return -EINVAL; | |
159 | if (len > TASK_SIZE) | |
160 | return -ENOMEM; | |
161 | ||
162 | if (addr) { | |
163 | addr = ALIGN(addr, HPAGE_SIZE); | |
164 | vma = find_vma(mm, addr); | |
165 | if (TASK_SIZE - len >= addr && | |
166 | (!vma || addr + len <= vma->vm_start)) | |
167 | return addr; | |
168 | } | |
169 | ||
170 | start_addr = mm->free_area_cache; | |
171 | ||
1363c3cd WW |
172 | if (len <= mm->cached_hole_size) |
173 | start_addr = TASK_UNMAPPED_BASE; | |
174 | ||
1da177e4 LT |
175 | full_search: |
176 | addr = ALIGN(start_addr, HPAGE_SIZE); | |
177 | ||
178 | for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { | |
179 | /* At this point: (!vma || addr < vma->vm_end). */ | |
180 | if (TASK_SIZE - len < addr) { | |
181 | /* | |
182 | * Start a new search - just in case we missed | |
183 | * some holes. | |
184 | */ | |
185 | if (start_addr != TASK_UNMAPPED_BASE) { | |
186 | start_addr = TASK_UNMAPPED_BASE; | |
187 | goto full_search; | |
188 | } | |
189 | return -ENOMEM; | |
190 | } | |
191 | ||
192 | if (!vma || addr + len <= vma->vm_start) | |
193 | return addr; | |
194 | addr = ALIGN(vma->vm_end, HPAGE_SIZE); | |
195 | } | |
196 | } | |
197 | #endif | |
198 | ||
199 | /* | |
200 | * Read a page. Again trivial. If it didn't already exist | |
201 | * in the page cache, it is zero-filled. | |
202 | */ | |
203 | static int hugetlbfs_readpage(struct file *file, struct page * page) | |
204 | { | |
205 | unlock_page(page); | |
206 | return -EINVAL; | |
207 | } | |
208 | ||
209 | static int hugetlbfs_prepare_write(struct file *file, | |
210 | struct page *page, unsigned offset, unsigned to) | |
211 | { | |
212 | return -EINVAL; | |
213 | } | |
214 | ||
215 | static int hugetlbfs_commit_write(struct file *file, | |
216 | struct page *page, unsigned offset, unsigned to) | |
217 | { | |
218 | return -EINVAL; | |
219 | } | |
220 | ||
1da177e4 LT |
221 | static void truncate_huge_page(struct page *page) |
222 | { | |
223 | clear_page_dirty(page); | |
224 | ClearPageUptodate(page); | |
225 | remove_from_page_cache(page); | |
226 | put_page(page); | |
227 | } | |
228 | ||
229 | static void truncate_hugepages(struct address_space *mapping, loff_t lstart) | |
230 | { | |
231 | const pgoff_t start = lstart >> HPAGE_SHIFT; | |
232 | struct pagevec pvec; | |
233 | pgoff_t next; | |
234 | int i; | |
235 | ||
236 | pagevec_init(&pvec, 0); | |
237 | next = start; | |
238 | while (1) { | |
239 | if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) { | |
240 | if (next == start) | |
241 | break; | |
242 | next = start; | |
243 | continue; | |
244 | } | |
245 | ||
246 | for (i = 0; i < pagevec_count(&pvec); ++i) { | |
247 | struct page *page = pvec.pages[i]; | |
248 | ||
249 | lock_page(page); | |
250 | if (page->index > next) | |
251 | next = page->index; | |
252 | ++next; | |
253 | truncate_huge_page(page); | |
254 | unlock_page(page); | |
255 | hugetlb_put_quota(mapping); | |
256 | } | |
257 | huge_pagevec_release(&pvec); | |
258 | } | |
259 | BUG_ON(!lstart && mapping->nrpages); | |
260 | } | |
261 | ||
262 | static void hugetlbfs_delete_inode(struct inode *inode) | |
263 | { | |
149f4211 CH |
264 | if (inode->i_data.nrpages) |
265 | truncate_hugepages(&inode->i_data, 0); | |
266 | clear_inode(inode); | |
267 | } | |
268 | ||
1da177e4 LT |
269 | static void hugetlbfs_forget_inode(struct inode *inode) |
270 | { | |
0b1533f6 CH |
271 | struct super_block *sb = inode->i_sb; |
272 | ||
273 | if (!hlist_unhashed(&inode->i_hash)) { | |
274 | if (!(inode->i_state & (I_DIRTY|I_LOCK))) | |
275 | list_move(&inode->i_list, &inode_unused); | |
276 | inodes_stat.nr_unused++; | |
277 | if (!sb || (sb->s_flags & MS_ACTIVE)) { | |
278 | spin_unlock(&inode_lock); | |
279 | return; | |
280 | } | |
281 | inode->i_state |= I_WILL_FREE; | |
1da177e4 | 282 | spin_unlock(&inode_lock); |
0b1533f6 CH |
283 | /* |
284 | * write_inode_now is a noop as we set BDI_CAP_NO_WRITEBACK | |
285 | * in our backing_dev_info. | |
286 | */ | |
287 | write_inode_now(inode, 1); | |
288 | spin_lock(&inode_lock); | |
289 | inode->i_state &= ~I_WILL_FREE; | |
290 | inodes_stat.nr_unused--; | |
291 | hlist_del_init(&inode->i_hash); | |
1da177e4 | 292 | } |
1da177e4 LT |
293 | list_del_init(&inode->i_list); |
294 | list_del_init(&inode->i_sb_list); | |
295 | inode->i_state |= I_FREEING; | |
296 | inodes_stat.nr_inodes--; | |
297 | spin_unlock(&inode_lock); | |
298 | if (inode->i_data.nrpages) | |
299 | truncate_hugepages(&inode->i_data, 0); | |
1da177e4 LT |
300 | clear_inode(inode); |
301 | destroy_inode(inode); | |
302 | } | |
303 | ||
304 | static void hugetlbfs_drop_inode(struct inode *inode) | |
305 | { | |
306 | if (!inode->i_nlink) | |
6b09b9df | 307 | generic_delete_inode(inode); |
1da177e4 LT |
308 | else |
309 | hugetlbfs_forget_inode(inode); | |
310 | } | |
311 | ||
312 | /* | |
313 | * h_pgoff is in HPAGE_SIZE units. | |
314 | * vma->vm_pgoff is in PAGE_SIZE units. | |
315 | */ | |
316 | static inline void | |
317 | hugetlb_vmtruncate_list(struct prio_tree_root *root, unsigned long h_pgoff) | |
318 | { | |
319 | struct vm_area_struct *vma; | |
320 | struct prio_tree_iter iter; | |
321 | ||
322 | vma_prio_tree_foreach(vma, &iter, root, h_pgoff, ULONG_MAX) { | |
323 | unsigned long h_vm_pgoff; | |
1da177e4 LT |
324 | unsigned long v_offset; |
325 | ||
326 | h_vm_pgoff = vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT); | |
327 | v_offset = (h_pgoff - h_vm_pgoff) << HPAGE_SHIFT; | |
328 | /* | |
329 | * Is this VMA fully outside the truncation point? | |
330 | */ | |
331 | if (h_vm_pgoff >= h_pgoff) | |
332 | v_offset = 0; | |
333 | ||
508034a3 HD |
334 | unmap_hugepage_range(vma, |
335 | vma->vm_start + v_offset, vma->vm_end); | |
1da177e4 LT |
336 | } |
337 | } | |
338 | ||
339 | /* | |
340 | * Expanding truncates are not allowed. | |
341 | */ | |
342 | static int hugetlb_vmtruncate(struct inode *inode, loff_t offset) | |
343 | { | |
344 | unsigned long pgoff; | |
345 | struct address_space *mapping = inode->i_mapping; | |
346 | ||
347 | if (offset > inode->i_size) | |
348 | return -EINVAL; | |
349 | ||
350 | BUG_ON(offset & ~HPAGE_MASK); | |
351 | pgoff = offset >> HPAGE_SHIFT; | |
352 | ||
353 | inode->i_size = offset; | |
354 | spin_lock(&mapping->i_mmap_lock); | |
355 | if (!prio_tree_empty(&mapping->i_mmap)) | |
356 | hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff); | |
357 | spin_unlock(&mapping->i_mmap_lock); | |
358 | truncate_hugepages(mapping, offset); | |
359 | return 0; | |
360 | } | |
361 | ||
362 | static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr) | |
363 | { | |
364 | struct inode *inode = dentry->d_inode; | |
365 | int error; | |
366 | unsigned int ia_valid = attr->ia_valid; | |
367 | ||
368 | BUG_ON(!inode); | |
369 | ||
370 | error = inode_change_ok(inode, attr); | |
371 | if (error) | |
372 | goto out; | |
373 | ||
374 | if (ia_valid & ATTR_SIZE) { | |
375 | error = -EINVAL; | |
376 | if (!(attr->ia_size & ~HPAGE_MASK)) | |
377 | error = hugetlb_vmtruncate(inode, attr->ia_size); | |
378 | if (error) | |
379 | goto out; | |
380 | attr->ia_valid &= ~ATTR_SIZE; | |
381 | } | |
382 | error = inode_setattr(inode, attr); | |
383 | out: | |
384 | return error; | |
385 | } | |
386 | ||
387 | static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid, | |
388 | gid_t gid, int mode, dev_t dev) | |
389 | { | |
390 | struct inode *inode; | |
1da177e4 LT |
391 | |
392 | inode = new_inode(sb); | |
393 | if (inode) { | |
394 | struct hugetlbfs_inode_info *info; | |
395 | inode->i_mode = mode; | |
396 | inode->i_uid = uid; | |
397 | inode->i_gid = gid; | |
398 | inode->i_blksize = HPAGE_SIZE; | |
399 | inode->i_blocks = 0; | |
400 | inode->i_mapping->a_ops = &hugetlbfs_aops; | |
401 | inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info; | |
402 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
403 | info = HUGETLBFS_I(inode); | |
404 | mpol_shared_policy_init(&info->policy); | |
405 | switch (mode & S_IFMT) { | |
406 | default: | |
407 | init_special_inode(inode, mode, dev); | |
408 | break; | |
409 | case S_IFREG: | |
410 | inode->i_op = &hugetlbfs_inode_operations; | |
411 | inode->i_fop = &hugetlbfs_file_operations; | |
412 | break; | |
413 | case S_IFDIR: | |
414 | inode->i_op = &hugetlbfs_dir_inode_operations; | |
415 | inode->i_fop = &simple_dir_operations; | |
416 | ||
417 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ | |
418 | inode->i_nlink++; | |
419 | break; | |
420 | case S_IFLNK: | |
421 | inode->i_op = &page_symlink_inode_operations; | |
422 | break; | |
423 | } | |
424 | } | |
425 | return inode; | |
426 | } | |
427 | ||
428 | /* | |
429 | * File creation. Allocate an inode, and we're done.. | |
430 | */ | |
431 | static int hugetlbfs_mknod(struct inode *dir, | |
432 | struct dentry *dentry, int mode, dev_t dev) | |
433 | { | |
434 | struct inode *inode; | |
435 | int error = -ENOSPC; | |
436 | gid_t gid; | |
437 | ||
438 | if (dir->i_mode & S_ISGID) { | |
439 | gid = dir->i_gid; | |
440 | if (S_ISDIR(mode)) | |
441 | mode |= S_ISGID; | |
442 | } else { | |
443 | gid = current->fsgid; | |
444 | } | |
445 | inode = hugetlbfs_get_inode(dir->i_sb, current->fsuid, gid, mode, dev); | |
446 | if (inode) { | |
447 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
448 | d_instantiate(dentry, inode); | |
449 | dget(dentry); /* Extra count - pin the dentry in core */ | |
450 | error = 0; | |
451 | } | |
452 | return error; | |
453 | } | |
454 | ||
455 | static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
456 | { | |
457 | int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0); | |
458 | if (!retval) | |
459 | dir->i_nlink++; | |
460 | return retval; | |
461 | } | |
462 | ||
463 | static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) | |
464 | { | |
465 | return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0); | |
466 | } | |
467 | ||
468 | static int hugetlbfs_symlink(struct inode *dir, | |
469 | struct dentry *dentry, const char *symname) | |
470 | { | |
471 | struct inode *inode; | |
472 | int error = -ENOSPC; | |
473 | gid_t gid; | |
474 | ||
475 | if (dir->i_mode & S_ISGID) | |
476 | gid = dir->i_gid; | |
477 | else | |
478 | gid = current->fsgid; | |
479 | ||
480 | inode = hugetlbfs_get_inode(dir->i_sb, current->fsuid, | |
481 | gid, S_IFLNK|S_IRWXUGO, 0); | |
482 | if (inode) { | |
483 | int l = strlen(symname)+1; | |
484 | error = page_symlink(inode, symname, l); | |
485 | if (!error) { | |
486 | d_instantiate(dentry, inode); | |
487 | dget(dentry); | |
488 | } else | |
489 | iput(inode); | |
490 | } | |
491 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
492 | ||
493 | return error; | |
494 | } | |
495 | ||
496 | /* | |
497 | * For direct-IO reads into hugetlb pages | |
498 | */ | |
499 | static int hugetlbfs_set_page_dirty(struct page *page) | |
500 | { | |
501 | return 0; | |
502 | } | |
503 | ||
504 | static int hugetlbfs_statfs(struct super_block *sb, struct kstatfs *buf) | |
505 | { | |
506 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); | |
507 | ||
508 | buf->f_type = HUGETLBFS_MAGIC; | |
509 | buf->f_bsize = HPAGE_SIZE; | |
510 | if (sbinfo) { | |
511 | spin_lock(&sbinfo->stat_lock); | |
74a8a65c DG |
512 | /* If no limits set, just report 0 for max/free/used |
513 | * blocks, like simple_statfs() */ | |
514 | if (sbinfo->max_blocks >= 0) { | |
515 | buf->f_blocks = sbinfo->max_blocks; | |
516 | buf->f_bavail = buf->f_bfree = sbinfo->free_blocks; | |
517 | buf->f_files = sbinfo->max_inodes; | |
518 | buf->f_ffree = sbinfo->free_inodes; | |
519 | } | |
1da177e4 LT |
520 | spin_unlock(&sbinfo->stat_lock); |
521 | } | |
522 | buf->f_namelen = NAME_MAX; | |
523 | return 0; | |
524 | } | |
525 | ||
526 | static void hugetlbfs_put_super(struct super_block *sb) | |
527 | { | |
528 | struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb); | |
529 | ||
530 | if (sbi) { | |
531 | sb->s_fs_info = NULL; | |
532 | kfree(sbi); | |
533 | } | |
534 | } | |
535 | ||
96527980 CH |
536 | static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo) |
537 | { | |
538 | if (sbinfo->free_inodes >= 0) { | |
539 | spin_lock(&sbinfo->stat_lock); | |
540 | if (unlikely(!sbinfo->free_inodes)) { | |
541 | spin_unlock(&sbinfo->stat_lock); | |
542 | return 0; | |
543 | } | |
544 | sbinfo->free_inodes--; | |
545 | spin_unlock(&sbinfo->stat_lock); | |
546 | } | |
547 | ||
548 | return 1; | |
549 | } | |
550 | ||
551 | static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo) | |
552 | { | |
553 | if (sbinfo->free_inodes >= 0) { | |
554 | spin_lock(&sbinfo->stat_lock); | |
555 | sbinfo->free_inodes++; | |
556 | spin_unlock(&sbinfo->stat_lock); | |
557 | } | |
558 | } | |
559 | ||
560 | ||
1da177e4 LT |
561 | static kmem_cache_t *hugetlbfs_inode_cachep; |
562 | ||
563 | static struct inode *hugetlbfs_alloc_inode(struct super_block *sb) | |
564 | { | |
96527980 | 565 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); |
1da177e4 LT |
566 | struct hugetlbfs_inode_info *p; |
567 | ||
96527980 CH |
568 | if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo))) |
569 | return NULL; | |
1da177e4 | 570 | p = kmem_cache_alloc(hugetlbfs_inode_cachep, SLAB_KERNEL); |
96527980 CH |
571 | if (unlikely(!p)) { |
572 | hugetlbfs_inc_free_inodes(sbinfo); | |
1da177e4 | 573 | return NULL; |
96527980 | 574 | } |
1da177e4 LT |
575 | return &p->vfs_inode; |
576 | } | |
577 | ||
1da177e4 LT |
578 | static void hugetlbfs_destroy_inode(struct inode *inode) |
579 | { | |
96527980 | 580 | hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb)); |
1da177e4 LT |
581 | mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy); |
582 | kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode)); | |
583 | } | |
584 | ||
585 | static struct address_space_operations hugetlbfs_aops = { | |
586 | .readpage = hugetlbfs_readpage, | |
587 | .prepare_write = hugetlbfs_prepare_write, | |
588 | .commit_write = hugetlbfs_commit_write, | |
589 | .set_page_dirty = hugetlbfs_set_page_dirty, | |
590 | }; | |
591 | ||
96527980 CH |
592 | |
593 | static void init_once(void *foo, kmem_cache_t *cachep, unsigned long flags) | |
594 | { | |
595 | struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo; | |
596 | ||
597 | if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == | |
598 | SLAB_CTOR_CONSTRUCTOR) | |
599 | inode_init_once(&ei->vfs_inode); | |
600 | } | |
601 | ||
1da177e4 LT |
602 | struct file_operations hugetlbfs_file_operations = { |
603 | .mmap = hugetlbfs_file_mmap, | |
604 | .fsync = simple_sync_file, | |
605 | .get_unmapped_area = hugetlb_get_unmapped_area, | |
606 | }; | |
607 | ||
608 | static struct inode_operations hugetlbfs_dir_inode_operations = { | |
609 | .create = hugetlbfs_create, | |
610 | .lookup = simple_lookup, | |
611 | .link = simple_link, | |
612 | .unlink = simple_unlink, | |
613 | .symlink = hugetlbfs_symlink, | |
614 | .mkdir = hugetlbfs_mkdir, | |
615 | .rmdir = simple_rmdir, | |
616 | .mknod = hugetlbfs_mknod, | |
617 | .rename = simple_rename, | |
618 | .setattr = hugetlbfs_setattr, | |
619 | }; | |
620 | ||
621 | static struct inode_operations hugetlbfs_inode_operations = { | |
622 | .setattr = hugetlbfs_setattr, | |
623 | }; | |
624 | ||
625 | static struct super_operations hugetlbfs_ops = { | |
626 | .alloc_inode = hugetlbfs_alloc_inode, | |
627 | .destroy_inode = hugetlbfs_destroy_inode, | |
628 | .statfs = hugetlbfs_statfs, | |
149f4211 | 629 | .delete_inode = hugetlbfs_delete_inode, |
1da177e4 LT |
630 | .drop_inode = hugetlbfs_drop_inode, |
631 | .put_super = hugetlbfs_put_super, | |
632 | }; | |
633 | ||
634 | static int | |
635 | hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig) | |
636 | { | |
637 | char *opt, *value, *rest; | |
638 | ||
639 | if (!options) | |
640 | return 0; | |
641 | while ((opt = strsep(&options, ",")) != NULL) { | |
642 | if (!*opt) | |
643 | continue; | |
644 | ||
645 | value = strchr(opt, '='); | |
646 | if (!value || !*value) | |
647 | return -EINVAL; | |
648 | else | |
649 | *value++ = '\0'; | |
650 | ||
651 | if (!strcmp(opt, "uid")) | |
652 | pconfig->uid = simple_strtoul(value, &value, 0); | |
653 | else if (!strcmp(opt, "gid")) | |
654 | pconfig->gid = simple_strtoul(value, &value, 0); | |
655 | else if (!strcmp(opt, "mode")) | |
656 | pconfig->mode = simple_strtoul(value,&value,0) & 0777U; | |
657 | else if (!strcmp(opt, "size")) { | |
658 | unsigned long long size = memparse(value, &rest); | |
659 | if (*rest == '%') { | |
660 | size <<= HPAGE_SHIFT; | |
661 | size *= max_huge_pages; | |
662 | do_div(size, 100); | |
663 | rest++; | |
664 | } | |
665 | size &= HPAGE_MASK; | |
666 | pconfig->nr_blocks = (size >> HPAGE_SHIFT); | |
667 | value = rest; | |
668 | } else if (!strcmp(opt,"nr_inodes")) { | |
669 | pconfig->nr_inodes = memparse(value, &rest); | |
670 | value = rest; | |
671 | } else | |
672 | return -EINVAL; | |
673 | ||
674 | if (*value) | |
675 | return -EINVAL; | |
676 | } | |
677 | return 0; | |
678 | } | |
679 | ||
680 | static int | |
681 | hugetlbfs_fill_super(struct super_block *sb, void *data, int silent) | |
682 | { | |
683 | struct inode * inode; | |
684 | struct dentry * root; | |
685 | int ret; | |
686 | struct hugetlbfs_config config; | |
687 | struct hugetlbfs_sb_info *sbinfo; | |
688 | ||
689 | config.nr_blocks = -1; /* No limit on size by default */ | |
690 | config.nr_inodes = -1; /* No limit on number of inodes by default */ | |
691 | config.uid = current->fsuid; | |
692 | config.gid = current->fsgid; | |
693 | config.mode = 0755; | |
694 | ret = hugetlbfs_parse_options(data, &config); | |
695 | ||
696 | if (ret) | |
697 | return ret; | |
698 | ||
699 | sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL); | |
700 | if (!sbinfo) | |
701 | return -ENOMEM; | |
702 | sb->s_fs_info = sbinfo; | |
703 | spin_lock_init(&sbinfo->stat_lock); | |
704 | sbinfo->max_blocks = config.nr_blocks; | |
705 | sbinfo->free_blocks = config.nr_blocks; | |
706 | sbinfo->max_inodes = config.nr_inodes; | |
707 | sbinfo->free_inodes = config.nr_inodes; | |
708 | sb->s_maxbytes = MAX_LFS_FILESIZE; | |
709 | sb->s_blocksize = HPAGE_SIZE; | |
710 | sb->s_blocksize_bits = HPAGE_SHIFT; | |
711 | sb->s_magic = HUGETLBFS_MAGIC; | |
712 | sb->s_op = &hugetlbfs_ops; | |
713 | sb->s_time_gran = 1; | |
714 | inode = hugetlbfs_get_inode(sb, config.uid, config.gid, | |
715 | S_IFDIR | config.mode, 0); | |
716 | if (!inode) | |
717 | goto out_free; | |
718 | ||
719 | root = d_alloc_root(inode); | |
720 | if (!root) { | |
721 | iput(inode); | |
722 | goto out_free; | |
723 | } | |
724 | sb->s_root = root; | |
725 | return 0; | |
726 | out_free: | |
727 | kfree(sbinfo); | |
728 | return -ENOMEM; | |
729 | } | |
730 | ||
731 | int hugetlb_get_quota(struct address_space *mapping) | |
732 | { | |
733 | int ret = 0; | |
734 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); | |
735 | ||
736 | if (sbinfo->free_blocks > -1) { | |
737 | spin_lock(&sbinfo->stat_lock); | |
738 | if (sbinfo->free_blocks > 0) | |
739 | sbinfo->free_blocks--; | |
740 | else | |
741 | ret = -ENOMEM; | |
742 | spin_unlock(&sbinfo->stat_lock); | |
743 | } | |
744 | ||
745 | return ret; | |
746 | } | |
747 | ||
748 | void hugetlb_put_quota(struct address_space *mapping) | |
749 | { | |
750 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); | |
751 | ||
752 | if (sbinfo->free_blocks > -1) { | |
753 | spin_lock(&sbinfo->stat_lock); | |
754 | sbinfo->free_blocks++; | |
755 | spin_unlock(&sbinfo->stat_lock); | |
756 | } | |
757 | } | |
758 | ||
759 | static struct super_block *hugetlbfs_get_sb(struct file_system_type *fs_type, | |
760 | int flags, const char *dev_name, void *data) | |
761 | { | |
762 | return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super); | |
763 | } | |
764 | ||
765 | static struct file_system_type hugetlbfs_fs_type = { | |
766 | .name = "hugetlbfs", | |
767 | .get_sb = hugetlbfs_get_sb, | |
768 | .kill_sb = kill_litter_super, | |
769 | }; | |
770 | ||
771 | static struct vfsmount *hugetlbfs_vfsmount; | |
772 | ||
773 | /* | |
774 | * Return the next identifier for a shm file | |
775 | */ | |
776 | static unsigned long hugetlbfs_counter(void) | |
777 | { | |
778 | static DEFINE_SPINLOCK(lock); | |
779 | static unsigned long counter; | |
780 | unsigned long ret; | |
781 | ||
782 | spin_lock(&lock); | |
783 | ret = ++counter; | |
784 | spin_unlock(&lock); | |
785 | return ret; | |
786 | } | |
787 | ||
788 | static int can_do_hugetlb_shm(void) | |
789 | { | |
790 | return likely(capable(CAP_IPC_LOCK) || | |
791 | in_group_p(sysctl_hugetlb_shm_group) || | |
792 | can_do_mlock()); | |
793 | } | |
794 | ||
795 | struct file *hugetlb_zero_setup(size_t size) | |
796 | { | |
797 | int error = -ENOMEM; | |
798 | struct file *file; | |
799 | struct inode *inode; | |
800 | struct dentry *dentry, *root; | |
801 | struct qstr quick_string; | |
802 | char buf[16]; | |
803 | ||
804 | if (!can_do_hugetlb_shm()) | |
805 | return ERR_PTR(-EPERM); | |
806 | ||
807 | if (!is_hugepage_mem_enough(size)) | |
808 | return ERR_PTR(-ENOMEM); | |
809 | ||
810 | if (!user_shm_lock(size, current->user)) | |
811 | return ERR_PTR(-ENOMEM); | |
812 | ||
813 | root = hugetlbfs_vfsmount->mnt_root; | |
814 | snprintf(buf, 16, "%lu", hugetlbfs_counter()); | |
815 | quick_string.name = buf; | |
816 | quick_string.len = strlen(quick_string.name); | |
817 | quick_string.hash = 0; | |
818 | dentry = d_alloc(root, &quick_string); | |
819 | if (!dentry) | |
820 | goto out_shm_unlock; | |
821 | ||
822 | error = -ENFILE; | |
823 | file = get_empty_filp(); | |
824 | if (!file) | |
825 | goto out_dentry; | |
826 | ||
827 | error = -ENOSPC; | |
828 | inode = hugetlbfs_get_inode(root->d_sb, current->fsuid, | |
829 | current->fsgid, S_IFREG | S_IRWXUGO, 0); | |
830 | if (!inode) | |
831 | goto out_file; | |
832 | ||
833 | d_instantiate(dentry, inode); | |
834 | inode->i_size = size; | |
835 | inode->i_nlink = 0; | |
836 | file->f_vfsmnt = mntget(hugetlbfs_vfsmount); | |
837 | file->f_dentry = dentry; | |
838 | file->f_mapping = inode->i_mapping; | |
839 | file->f_op = &hugetlbfs_file_operations; | |
840 | file->f_mode = FMODE_WRITE | FMODE_READ; | |
841 | return file; | |
842 | ||
843 | out_file: | |
844 | put_filp(file); | |
845 | out_dentry: | |
846 | dput(dentry); | |
847 | out_shm_unlock: | |
848 | user_shm_unlock(size, current->user); | |
849 | return ERR_PTR(error); | |
850 | } | |
851 | ||
852 | static int __init init_hugetlbfs_fs(void) | |
853 | { | |
854 | int error; | |
855 | struct vfsmount *vfsmount; | |
856 | ||
857 | hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache", | |
858 | sizeof(struct hugetlbfs_inode_info), | |
859 | 0, 0, init_once, NULL); | |
860 | if (hugetlbfs_inode_cachep == NULL) | |
861 | return -ENOMEM; | |
862 | ||
863 | error = register_filesystem(&hugetlbfs_fs_type); | |
864 | if (error) | |
865 | goto out; | |
866 | ||
867 | vfsmount = kern_mount(&hugetlbfs_fs_type); | |
868 | ||
869 | if (!IS_ERR(vfsmount)) { | |
870 | hugetlbfs_vfsmount = vfsmount; | |
871 | return 0; | |
872 | } | |
873 | ||
874 | error = PTR_ERR(vfsmount); | |
875 | ||
876 | out: | |
877 | if (error) | |
878 | kmem_cache_destroy(hugetlbfs_inode_cachep); | |
879 | return error; | |
880 | } | |
881 | ||
882 | static void __exit exit_hugetlbfs_fs(void) | |
883 | { | |
884 | kmem_cache_destroy(hugetlbfs_inode_cachep); | |
885 | unregister_filesystem(&hugetlbfs_fs_type); | |
886 | } | |
887 | ||
888 | module_init(init_hugetlbfs_fs) | |
889 | module_exit(exit_hugetlbfs_fs) | |
890 | ||
891 | MODULE_LICENSE("GPL"); |