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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> | |
16f7e0fe | 21 | #include <linux/capability.h> |
1da177e4 LT |
22 | #include <linux/backing-dev.h> |
23 | #include <linux/hugetlb.h> | |
24 | #include <linux/pagevec.h> | |
25 | #include <linux/quotaops.h> | |
26 | #include <linux/slab.h> | |
27 | #include <linux/dnotify.h> | |
28 | #include <linux/statfs.h> | |
29 | #include <linux/security.h> | |
30 | ||
31 | #include <asm/uaccess.h> | |
32 | ||
33 | /* some random number */ | |
34 | #define HUGETLBFS_MAGIC 0x958458f6 | |
35 | ||
36 | static struct super_operations hugetlbfs_ops; | |
37 | static struct address_space_operations hugetlbfs_aops; | |
38 | struct file_operations hugetlbfs_file_operations; | |
39 | static struct inode_operations hugetlbfs_dir_inode_operations; | |
40 | static struct inode_operations hugetlbfs_inode_operations; | |
41 | ||
42 | static struct backing_dev_info hugetlbfs_backing_dev_info = { | |
43 | .ra_pages = 0, /* No readahead */ | |
44 | .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK, | |
45 | }; | |
46 | ||
47 | int sysctl_hugetlb_shm_group; | |
48 | ||
2e9b367c AL |
49 | static void huge_pagevec_release(struct pagevec *pvec) |
50 | { | |
51 | int i; | |
52 | ||
53 | for (i = 0; i < pagevec_count(pvec); ++i) | |
54 | put_page(pvec->pages[i]); | |
55 | ||
56 | pagevec_reinit(pvec); | |
57 | } | |
58 | ||
59 | /* | |
60 | * huge_pages_needed tries to determine the number of new huge pages that | |
61 | * will be required to fully populate this VMA. This will be equal to | |
62 | * the size of the VMA in huge pages minus the number of huge pages | |
63 | * (covered by this VMA) that are found in the page cache. | |
64 | * | |
65 | * Result is in bytes to be compatible with is_hugepage_mem_enough() | |
66 | */ | |
8d3d81cf | 67 | static unsigned long |
2e9b367c AL |
68 | huge_pages_needed(struct address_space *mapping, struct vm_area_struct *vma) |
69 | { | |
70 | int i; | |
71 | struct pagevec pvec; | |
72 | unsigned long start = vma->vm_start; | |
73 | unsigned long end = vma->vm_end; | |
74 | unsigned long hugepages = (end - start) >> HPAGE_SHIFT; | |
75 | pgoff_t next = vma->vm_pgoff; | |
76 | pgoff_t endpg = next + ((end - start) >> PAGE_SHIFT); | |
77 | ||
78 | pagevec_init(&pvec, 0); | |
79 | while (next < endpg) { | |
80 | if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) | |
81 | break; | |
82 | for (i = 0; i < pagevec_count(&pvec); i++) { | |
83 | struct page *page = pvec.pages[i]; | |
84 | if (page->index > next) | |
85 | next = page->index; | |
86 | if (page->index >= endpg) | |
87 | break; | |
88 | next++; | |
89 | hugepages--; | |
90 | } | |
91 | huge_pagevec_release(&pvec); | |
92 | } | |
93 | return hugepages << HPAGE_SHIFT; | |
94 | } | |
95 | ||
1da177e4 LT |
96 | static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma) |
97 | { | |
98 | struct inode *inode = file->f_dentry->d_inode; | |
2e9b367c AL |
99 | struct address_space *mapping = inode->i_mapping; |
100 | unsigned long bytes; | |
1da177e4 LT |
101 | loff_t len, vma_len; |
102 | int ret; | |
103 | ||
1da177e4 LT |
104 | if (vma->vm_pgoff & (HPAGE_SIZE / PAGE_SIZE - 1)) |
105 | return -EINVAL; | |
106 | ||
107 | if (vma->vm_start & ~HPAGE_MASK) | |
108 | return -EINVAL; | |
109 | ||
110 | if (vma->vm_end & ~HPAGE_MASK) | |
111 | return -EINVAL; | |
112 | ||
113 | if (vma->vm_end - vma->vm_start < HPAGE_SIZE) | |
114 | return -EINVAL; | |
115 | ||
2e9b367c AL |
116 | bytes = huge_pages_needed(mapping, vma); |
117 | if (!is_hugepage_mem_enough(bytes)) | |
118 | return -ENOMEM; | |
119 | ||
1da177e4 LT |
120 | vma_len = (loff_t)(vma->vm_end - vma->vm_start); |
121 | ||
1b1dcc1b | 122 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
123 | file_accessed(file); |
124 | vma->vm_flags |= VM_HUGETLB | VM_RESERVED; | |
125 | vma->vm_ops = &hugetlb_vm_ops; | |
126 | ||
127 | ret = -ENOMEM; | |
128 | len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
129 | if (!(vma->vm_flags & VM_WRITE) && len > inode->i_size) | |
130 | goto out; | |
131 | ||
4c887265 AL |
132 | ret = 0; |
133 | hugetlb_prefault_arch_hook(vma->vm_mm); | |
1da177e4 LT |
134 | if (inode->i_size < len) |
135 | inode->i_size = len; | |
136 | out: | |
1b1dcc1b | 137 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
138 | |
139 | return ret; | |
140 | } | |
141 | ||
142 | /* | |
508034a3 | 143 | * Called under down_write(mmap_sem). |
1da177e4 LT |
144 | */ |
145 | ||
146 | #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA | |
147 | unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, | |
148 | unsigned long len, unsigned long pgoff, unsigned long flags); | |
149 | #else | |
150 | static unsigned long | |
151 | hugetlb_get_unmapped_area(struct file *file, unsigned long addr, | |
152 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
153 | { | |
154 | struct mm_struct *mm = current->mm; | |
155 | struct vm_area_struct *vma; | |
156 | unsigned long start_addr; | |
157 | ||
158 | if (len & ~HPAGE_MASK) | |
159 | return -EINVAL; | |
160 | if (len > TASK_SIZE) | |
161 | return -ENOMEM; | |
162 | ||
163 | if (addr) { | |
164 | addr = ALIGN(addr, HPAGE_SIZE); | |
165 | vma = find_vma(mm, addr); | |
166 | if (TASK_SIZE - len >= addr && | |
167 | (!vma || addr + len <= vma->vm_start)) | |
168 | return addr; | |
169 | } | |
170 | ||
171 | start_addr = mm->free_area_cache; | |
172 | ||
1363c3cd WW |
173 | if (len <= mm->cached_hole_size) |
174 | start_addr = TASK_UNMAPPED_BASE; | |
175 | ||
1da177e4 LT |
176 | full_search: |
177 | addr = ALIGN(start_addr, HPAGE_SIZE); | |
178 | ||
179 | for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { | |
180 | /* At this point: (!vma || addr < vma->vm_end). */ | |
181 | if (TASK_SIZE - len < addr) { | |
182 | /* | |
183 | * Start a new search - just in case we missed | |
184 | * some holes. | |
185 | */ | |
186 | if (start_addr != TASK_UNMAPPED_BASE) { | |
187 | start_addr = TASK_UNMAPPED_BASE; | |
188 | goto full_search; | |
189 | } | |
190 | return -ENOMEM; | |
191 | } | |
192 | ||
193 | if (!vma || addr + len <= vma->vm_start) | |
194 | return addr; | |
195 | addr = ALIGN(vma->vm_end, HPAGE_SIZE); | |
196 | } | |
197 | } | |
198 | #endif | |
199 | ||
200 | /* | |
201 | * Read a page. Again trivial. If it didn't already exist | |
202 | * in the page cache, it is zero-filled. | |
203 | */ | |
204 | static int hugetlbfs_readpage(struct file *file, struct page * page) | |
205 | { | |
206 | unlock_page(page); | |
207 | return -EINVAL; | |
208 | } | |
209 | ||
210 | static int hugetlbfs_prepare_write(struct file *file, | |
211 | struct page *page, unsigned offset, unsigned to) | |
212 | { | |
213 | return -EINVAL; | |
214 | } | |
215 | ||
216 | static int hugetlbfs_commit_write(struct file *file, | |
217 | struct page *page, unsigned offset, unsigned to) | |
218 | { | |
219 | return -EINVAL; | |
220 | } | |
221 | ||
1da177e4 LT |
222 | static void truncate_huge_page(struct page *page) |
223 | { | |
224 | clear_page_dirty(page); | |
225 | ClearPageUptodate(page); | |
226 | remove_from_page_cache(page); | |
227 | put_page(page); | |
228 | } | |
229 | ||
230 | static void truncate_hugepages(struct address_space *mapping, loff_t lstart) | |
231 | { | |
232 | const pgoff_t start = lstart >> HPAGE_SHIFT; | |
233 | struct pagevec pvec; | |
234 | pgoff_t next; | |
235 | int i; | |
236 | ||
237 | pagevec_init(&pvec, 0); | |
238 | next = start; | |
239 | while (1) { | |
240 | if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) { | |
241 | if (next == start) | |
242 | break; | |
243 | next = start; | |
244 | continue; | |
245 | } | |
246 | ||
247 | for (i = 0; i < pagevec_count(&pvec); ++i) { | |
248 | struct page *page = pvec.pages[i]; | |
249 | ||
250 | lock_page(page); | |
251 | if (page->index > next) | |
252 | next = page->index; | |
253 | ++next; | |
254 | truncate_huge_page(page); | |
255 | unlock_page(page); | |
256 | hugetlb_put_quota(mapping); | |
257 | } | |
258 | huge_pagevec_release(&pvec); | |
259 | } | |
260 | BUG_ON(!lstart && mapping->nrpages); | |
261 | } | |
262 | ||
263 | static void hugetlbfs_delete_inode(struct inode *inode) | |
264 | { | |
149f4211 CH |
265 | if (inode->i_data.nrpages) |
266 | truncate_hugepages(&inode->i_data, 0); | |
267 | clear_inode(inode); | |
268 | } | |
269 | ||
1da177e4 LT |
270 | static void hugetlbfs_forget_inode(struct inode *inode) |
271 | { | |
0b1533f6 CH |
272 | struct super_block *sb = inode->i_sb; |
273 | ||
274 | if (!hlist_unhashed(&inode->i_hash)) { | |
275 | if (!(inode->i_state & (I_DIRTY|I_LOCK))) | |
276 | list_move(&inode->i_list, &inode_unused); | |
277 | inodes_stat.nr_unused++; | |
278 | if (!sb || (sb->s_flags & MS_ACTIVE)) { | |
279 | spin_unlock(&inode_lock); | |
280 | return; | |
281 | } | |
282 | inode->i_state |= I_WILL_FREE; | |
1da177e4 | 283 | spin_unlock(&inode_lock); |
0b1533f6 CH |
284 | /* |
285 | * write_inode_now is a noop as we set BDI_CAP_NO_WRITEBACK | |
286 | * in our backing_dev_info. | |
287 | */ | |
288 | write_inode_now(inode, 1); | |
289 | spin_lock(&inode_lock); | |
290 | inode->i_state &= ~I_WILL_FREE; | |
291 | inodes_stat.nr_unused--; | |
292 | hlist_del_init(&inode->i_hash); | |
1da177e4 | 293 | } |
1da177e4 LT |
294 | list_del_init(&inode->i_list); |
295 | list_del_init(&inode->i_sb_list); | |
296 | inode->i_state |= I_FREEING; | |
297 | inodes_stat.nr_inodes--; | |
298 | spin_unlock(&inode_lock); | |
299 | if (inode->i_data.nrpages) | |
300 | truncate_hugepages(&inode->i_data, 0); | |
1da177e4 LT |
301 | clear_inode(inode); |
302 | destroy_inode(inode); | |
303 | } | |
304 | ||
305 | static void hugetlbfs_drop_inode(struct inode *inode) | |
306 | { | |
307 | if (!inode->i_nlink) | |
6b09b9df | 308 | generic_delete_inode(inode); |
1da177e4 LT |
309 | else |
310 | hugetlbfs_forget_inode(inode); | |
311 | } | |
312 | ||
313 | /* | |
314 | * h_pgoff is in HPAGE_SIZE units. | |
315 | * vma->vm_pgoff is in PAGE_SIZE units. | |
316 | */ | |
317 | static inline void | |
318 | hugetlb_vmtruncate_list(struct prio_tree_root *root, unsigned long h_pgoff) | |
319 | { | |
320 | struct vm_area_struct *vma; | |
321 | struct prio_tree_iter iter; | |
322 | ||
323 | vma_prio_tree_foreach(vma, &iter, root, h_pgoff, ULONG_MAX) { | |
324 | unsigned long h_vm_pgoff; | |
1da177e4 LT |
325 | unsigned long v_offset; |
326 | ||
327 | h_vm_pgoff = vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT); | |
328 | v_offset = (h_pgoff - h_vm_pgoff) << HPAGE_SHIFT; | |
329 | /* | |
330 | * Is this VMA fully outside the truncation point? | |
331 | */ | |
332 | if (h_vm_pgoff >= h_pgoff) | |
333 | v_offset = 0; | |
334 | ||
508034a3 HD |
335 | unmap_hugepage_range(vma, |
336 | vma->vm_start + v_offset, vma->vm_end); | |
1da177e4 LT |
337 | } |
338 | } | |
339 | ||
340 | /* | |
341 | * Expanding truncates are not allowed. | |
342 | */ | |
343 | static int hugetlb_vmtruncate(struct inode *inode, loff_t offset) | |
344 | { | |
345 | unsigned long pgoff; | |
346 | struct address_space *mapping = inode->i_mapping; | |
347 | ||
348 | if (offset > inode->i_size) | |
349 | return -EINVAL; | |
350 | ||
351 | BUG_ON(offset & ~HPAGE_MASK); | |
352 | pgoff = offset >> HPAGE_SHIFT; | |
353 | ||
354 | inode->i_size = offset; | |
355 | spin_lock(&mapping->i_mmap_lock); | |
356 | if (!prio_tree_empty(&mapping->i_mmap)) | |
357 | hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff); | |
358 | spin_unlock(&mapping->i_mmap_lock); | |
359 | truncate_hugepages(mapping, offset); | |
360 | return 0; | |
361 | } | |
362 | ||
363 | static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr) | |
364 | { | |
365 | struct inode *inode = dentry->d_inode; | |
366 | int error; | |
367 | unsigned int ia_valid = attr->ia_valid; | |
368 | ||
369 | BUG_ON(!inode); | |
370 | ||
371 | error = inode_change_ok(inode, attr); | |
372 | if (error) | |
373 | goto out; | |
374 | ||
375 | if (ia_valid & ATTR_SIZE) { | |
376 | error = -EINVAL; | |
377 | if (!(attr->ia_size & ~HPAGE_MASK)) | |
378 | error = hugetlb_vmtruncate(inode, attr->ia_size); | |
379 | if (error) | |
380 | goto out; | |
381 | attr->ia_valid &= ~ATTR_SIZE; | |
382 | } | |
383 | error = inode_setattr(inode, attr); | |
384 | out: | |
385 | return error; | |
386 | } | |
387 | ||
388 | static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid, | |
389 | gid_t gid, int mode, dev_t dev) | |
390 | { | |
391 | struct inode *inode; | |
1da177e4 LT |
392 | |
393 | inode = new_inode(sb); | |
394 | if (inode) { | |
395 | struct hugetlbfs_inode_info *info; | |
396 | inode->i_mode = mode; | |
397 | inode->i_uid = uid; | |
398 | inode->i_gid = gid; | |
399 | inode->i_blksize = HPAGE_SIZE; | |
400 | inode->i_blocks = 0; | |
401 | inode->i_mapping->a_ops = &hugetlbfs_aops; | |
402 | inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info; | |
403 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
404 | info = HUGETLBFS_I(inode); | |
7339ff83 | 405 | mpol_shared_policy_init(&info->policy, MPOL_DEFAULT, NULL); |
1da177e4 LT |
406 | switch (mode & S_IFMT) { |
407 | default: | |
408 | init_special_inode(inode, mode, dev); | |
409 | break; | |
410 | case S_IFREG: | |
411 | inode->i_op = &hugetlbfs_inode_operations; | |
412 | inode->i_fop = &hugetlbfs_file_operations; | |
413 | break; | |
414 | case S_IFDIR: | |
415 | inode->i_op = &hugetlbfs_dir_inode_operations; | |
416 | inode->i_fop = &simple_dir_operations; | |
417 | ||
418 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ | |
419 | inode->i_nlink++; | |
420 | break; | |
421 | case S_IFLNK: | |
422 | inode->i_op = &page_symlink_inode_operations; | |
423 | break; | |
424 | } | |
425 | } | |
426 | return inode; | |
427 | } | |
428 | ||
429 | /* | |
430 | * File creation. Allocate an inode, and we're done.. | |
431 | */ | |
432 | static int hugetlbfs_mknod(struct inode *dir, | |
433 | struct dentry *dentry, int mode, dev_t dev) | |
434 | { | |
435 | struct inode *inode; | |
436 | int error = -ENOSPC; | |
437 | gid_t gid; | |
438 | ||
439 | if (dir->i_mode & S_ISGID) { | |
440 | gid = dir->i_gid; | |
441 | if (S_ISDIR(mode)) | |
442 | mode |= S_ISGID; | |
443 | } else { | |
444 | gid = current->fsgid; | |
445 | } | |
446 | inode = hugetlbfs_get_inode(dir->i_sb, current->fsuid, gid, mode, dev); | |
447 | if (inode) { | |
448 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
449 | d_instantiate(dentry, inode); | |
450 | dget(dentry); /* Extra count - pin the dentry in core */ | |
451 | error = 0; | |
452 | } | |
453 | return error; | |
454 | } | |
455 | ||
456 | static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
457 | { | |
458 | int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0); | |
459 | if (!retval) | |
460 | dir->i_nlink++; | |
461 | return retval; | |
462 | } | |
463 | ||
464 | static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) | |
465 | { | |
466 | return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0); | |
467 | } | |
468 | ||
469 | static int hugetlbfs_symlink(struct inode *dir, | |
470 | struct dentry *dentry, const char *symname) | |
471 | { | |
472 | struct inode *inode; | |
473 | int error = -ENOSPC; | |
474 | gid_t gid; | |
475 | ||
476 | if (dir->i_mode & S_ISGID) | |
477 | gid = dir->i_gid; | |
478 | else | |
479 | gid = current->fsgid; | |
480 | ||
481 | inode = hugetlbfs_get_inode(dir->i_sb, current->fsuid, | |
482 | gid, S_IFLNK|S_IRWXUGO, 0); | |
483 | if (inode) { | |
484 | int l = strlen(symname)+1; | |
485 | error = page_symlink(inode, symname, l); | |
486 | if (!error) { | |
487 | d_instantiate(dentry, inode); | |
488 | dget(dentry); | |
489 | } else | |
490 | iput(inode); | |
491 | } | |
492 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
493 | ||
494 | return error; | |
495 | } | |
496 | ||
497 | /* | |
498 | * For direct-IO reads into hugetlb pages | |
499 | */ | |
500 | static int hugetlbfs_set_page_dirty(struct page *page) | |
501 | { | |
502 | return 0; | |
503 | } | |
504 | ||
505 | static int hugetlbfs_statfs(struct super_block *sb, struct kstatfs *buf) | |
506 | { | |
507 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); | |
508 | ||
509 | buf->f_type = HUGETLBFS_MAGIC; | |
510 | buf->f_bsize = HPAGE_SIZE; | |
511 | if (sbinfo) { | |
512 | spin_lock(&sbinfo->stat_lock); | |
74a8a65c DG |
513 | /* If no limits set, just report 0 for max/free/used |
514 | * blocks, like simple_statfs() */ | |
515 | if (sbinfo->max_blocks >= 0) { | |
516 | buf->f_blocks = sbinfo->max_blocks; | |
517 | buf->f_bavail = buf->f_bfree = sbinfo->free_blocks; | |
518 | buf->f_files = sbinfo->max_inodes; | |
519 | buf->f_ffree = sbinfo->free_inodes; | |
520 | } | |
1da177e4 LT |
521 | spin_unlock(&sbinfo->stat_lock); |
522 | } | |
523 | buf->f_namelen = NAME_MAX; | |
524 | return 0; | |
525 | } | |
526 | ||
527 | static void hugetlbfs_put_super(struct super_block *sb) | |
528 | { | |
529 | struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb); | |
530 | ||
531 | if (sbi) { | |
532 | sb->s_fs_info = NULL; | |
533 | kfree(sbi); | |
534 | } | |
535 | } | |
536 | ||
96527980 CH |
537 | static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo) |
538 | { | |
539 | if (sbinfo->free_inodes >= 0) { | |
540 | spin_lock(&sbinfo->stat_lock); | |
541 | if (unlikely(!sbinfo->free_inodes)) { | |
542 | spin_unlock(&sbinfo->stat_lock); | |
543 | return 0; | |
544 | } | |
545 | sbinfo->free_inodes--; | |
546 | spin_unlock(&sbinfo->stat_lock); | |
547 | } | |
548 | ||
549 | return 1; | |
550 | } | |
551 | ||
552 | static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo) | |
553 | { | |
554 | if (sbinfo->free_inodes >= 0) { | |
555 | spin_lock(&sbinfo->stat_lock); | |
556 | sbinfo->free_inodes++; | |
557 | spin_unlock(&sbinfo->stat_lock); | |
558 | } | |
559 | } | |
560 | ||
561 | ||
1da177e4 LT |
562 | static kmem_cache_t *hugetlbfs_inode_cachep; |
563 | ||
564 | static struct inode *hugetlbfs_alloc_inode(struct super_block *sb) | |
565 | { | |
96527980 | 566 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); |
1da177e4 LT |
567 | struct hugetlbfs_inode_info *p; |
568 | ||
96527980 CH |
569 | if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo))) |
570 | return NULL; | |
1da177e4 | 571 | p = kmem_cache_alloc(hugetlbfs_inode_cachep, SLAB_KERNEL); |
96527980 CH |
572 | if (unlikely(!p)) { |
573 | hugetlbfs_inc_free_inodes(sbinfo); | |
1da177e4 | 574 | return NULL; |
96527980 | 575 | } |
1da177e4 LT |
576 | return &p->vfs_inode; |
577 | } | |
578 | ||
1da177e4 LT |
579 | static void hugetlbfs_destroy_inode(struct inode *inode) |
580 | { | |
96527980 | 581 | hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb)); |
1da177e4 LT |
582 | mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy); |
583 | kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode)); | |
584 | } | |
585 | ||
586 | static struct address_space_operations hugetlbfs_aops = { | |
587 | .readpage = hugetlbfs_readpage, | |
588 | .prepare_write = hugetlbfs_prepare_write, | |
589 | .commit_write = hugetlbfs_commit_write, | |
590 | .set_page_dirty = hugetlbfs_set_page_dirty, | |
591 | }; | |
592 | ||
96527980 CH |
593 | |
594 | static void init_once(void *foo, kmem_cache_t *cachep, unsigned long flags) | |
595 | { | |
596 | struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo; | |
597 | ||
598 | if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == | |
599 | SLAB_CTOR_CONSTRUCTOR) | |
600 | inode_init_once(&ei->vfs_inode); | |
601 | } | |
602 | ||
1da177e4 LT |
603 | struct file_operations hugetlbfs_file_operations = { |
604 | .mmap = hugetlbfs_file_mmap, | |
605 | .fsync = simple_sync_file, | |
606 | .get_unmapped_area = hugetlb_get_unmapped_area, | |
607 | }; | |
608 | ||
609 | static struct inode_operations hugetlbfs_dir_inode_operations = { | |
610 | .create = hugetlbfs_create, | |
611 | .lookup = simple_lookup, | |
612 | .link = simple_link, | |
613 | .unlink = simple_unlink, | |
614 | .symlink = hugetlbfs_symlink, | |
615 | .mkdir = hugetlbfs_mkdir, | |
616 | .rmdir = simple_rmdir, | |
617 | .mknod = hugetlbfs_mknod, | |
618 | .rename = simple_rename, | |
619 | .setattr = hugetlbfs_setattr, | |
620 | }; | |
621 | ||
622 | static struct inode_operations hugetlbfs_inode_operations = { | |
623 | .setattr = hugetlbfs_setattr, | |
624 | }; | |
625 | ||
626 | static struct super_operations hugetlbfs_ops = { | |
627 | .alloc_inode = hugetlbfs_alloc_inode, | |
628 | .destroy_inode = hugetlbfs_destroy_inode, | |
629 | .statfs = hugetlbfs_statfs, | |
149f4211 | 630 | .delete_inode = hugetlbfs_delete_inode, |
1da177e4 LT |
631 | .drop_inode = hugetlbfs_drop_inode, |
632 | .put_super = hugetlbfs_put_super, | |
633 | }; | |
634 | ||
635 | static int | |
636 | hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig) | |
637 | { | |
638 | char *opt, *value, *rest; | |
639 | ||
640 | if (!options) | |
641 | return 0; | |
642 | while ((opt = strsep(&options, ",")) != NULL) { | |
643 | if (!*opt) | |
644 | continue; | |
645 | ||
646 | value = strchr(opt, '='); | |
647 | if (!value || !*value) | |
648 | return -EINVAL; | |
649 | else | |
650 | *value++ = '\0'; | |
651 | ||
652 | if (!strcmp(opt, "uid")) | |
653 | pconfig->uid = simple_strtoul(value, &value, 0); | |
654 | else if (!strcmp(opt, "gid")) | |
655 | pconfig->gid = simple_strtoul(value, &value, 0); | |
656 | else if (!strcmp(opt, "mode")) | |
657 | pconfig->mode = simple_strtoul(value,&value,0) & 0777U; | |
658 | else if (!strcmp(opt, "size")) { | |
659 | unsigned long long size = memparse(value, &rest); | |
660 | if (*rest == '%') { | |
661 | size <<= HPAGE_SHIFT; | |
662 | size *= max_huge_pages; | |
663 | do_div(size, 100); | |
664 | rest++; | |
665 | } | |
666 | size &= HPAGE_MASK; | |
667 | pconfig->nr_blocks = (size >> HPAGE_SHIFT); | |
668 | value = rest; | |
669 | } else if (!strcmp(opt,"nr_inodes")) { | |
670 | pconfig->nr_inodes = memparse(value, &rest); | |
671 | value = rest; | |
672 | } else | |
673 | return -EINVAL; | |
674 | ||
675 | if (*value) | |
676 | return -EINVAL; | |
677 | } | |
678 | return 0; | |
679 | } | |
680 | ||
681 | static int | |
682 | hugetlbfs_fill_super(struct super_block *sb, void *data, int silent) | |
683 | { | |
684 | struct inode * inode; | |
685 | struct dentry * root; | |
686 | int ret; | |
687 | struct hugetlbfs_config config; | |
688 | struct hugetlbfs_sb_info *sbinfo; | |
689 | ||
690 | config.nr_blocks = -1; /* No limit on size by default */ | |
691 | config.nr_inodes = -1; /* No limit on number of inodes by default */ | |
692 | config.uid = current->fsuid; | |
693 | config.gid = current->fsgid; | |
694 | config.mode = 0755; | |
695 | ret = hugetlbfs_parse_options(data, &config); | |
696 | ||
697 | if (ret) | |
698 | return ret; | |
699 | ||
700 | sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL); | |
701 | if (!sbinfo) | |
702 | return -ENOMEM; | |
703 | sb->s_fs_info = sbinfo; | |
704 | spin_lock_init(&sbinfo->stat_lock); | |
705 | sbinfo->max_blocks = config.nr_blocks; | |
706 | sbinfo->free_blocks = config.nr_blocks; | |
707 | sbinfo->max_inodes = config.nr_inodes; | |
708 | sbinfo->free_inodes = config.nr_inodes; | |
709 | sb->s_maxbytes = MAX_LFS_FILESIZE; | |
710 | sb->s_blocksize = HPAGE_SIZE; | |
711 | sb->s_blocksize_bits = HPAGE_SHIFT; | |
712 | sb->s_magic = HUGETLBFS_MAGIC; | |
713 | sb->s_op = &hugetlbfs_ops; | |
714 | sb->s_time_gran = 1; | |
715 | inode = hugetlbfs_get_inode(sb, config.uid, config.gid, | |
716 | S_IFDIR | config.mode, 0); | |
717 | if (!inode) | |
718 | goto out_free; | |
719 | ||
720 | root = d_alloc_root(inode); | |
721 | if (!root) { | |
722 | iput(inode); | |
723 | goto out_free; | |
724 | } | |
725 | sb->s_root = root; | |
726 | return 0; | |
727 | out_free: | |
728 | kfree(sbinfo); | |
729 | return -ENOMEM; | |
730 | } | |
731 | ||
732 | int hugetlb_get_quota(struct address_space *mapping) | |
733 | { | |
734 | int ret = 0; | |
735 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); | |
736 | ||
737 | if (sbinfo->free_blocks > -1) { | |
738 | spin_lock(&sbinfo->stat_lock); | |
739 | if (sbinfo->free_blocks > 0) | |
740 | sbinfo->free_blocks--; | |
741 | else | |
742 | ret = -ENOMEM; | |
743 | spin_unlock(&sbinfo->stat_lock); | |
744 | } | |
745 | ||
746 | return ret; | |
747 | } | |
748 | ||
749 | void hugetlb_put_quota(struct address_space *mapping) | |
750 | { | |
751 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); | |
752 | ||
753 | if (sbinfo->free_blocks > -1) { | |
754 | spin_lock(&sbinfo->stat_lock); | |
755 | sbinfo->free_blocks++; | |
756 | spin_unlock(&sbinfo->stat_lock); | |
757 | } | |
758 | } | |
759 | ||
760 | static struct super_block *hugetlbfs_get_sb(struct file_system_type *fs_type, | |
761 | int flags, const char *dev_name, void *data) | |
762 | { | |
763 | return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super); | |
764 | } | |
765 | ||
766 | static struct file_system_type hugetlbfs_fs_type = { | |
767 | .name = "hugetlbfs", | |
768 | .get_sb = hugetlbfs_get_sb, | |
769 | .kill_sb = kill_litter_super, | |
770 | }; | |
771 | ||
772 | static struct vfsmount *hugetlbfs_vfsmount; | |
773 | ||
774 | /* | |
775 | * Return the next identifier for a shm file | |
776 | */ | |
777 | static unsigned long hugetlbfs_counter(void) | |
778 | { | |
779 | static DEFINE_SPINLOCK(lock); | |
780 | static unsigned long counter; | |
781 | unsigned long ret; | |
782 | ||
783 | spin_lock(&lock); | |
784 | ret = ++counter; | |
785 | spin_unlock(&lock); | |
786 | return ret; | |
787 | } | |
788 | ||
789 | static int can_do_hugetlb_shm(void) | |
790 | { | |
791 | return likely(capable(CAP_IPC_LOCK) || | |
792 | in_group_p(sysctl_hugetlb_shm_group) || | |
793 | can_do_mlock()); | |
794 | } | |
795 | ||
796 | struct file *hugetlb_zero_setup(size_t size) | |
797 | { | |
798 | int error = -ENOMEM; | |
799 | struct file *file; | |
800 | struct inode *inode; | |
801 | struct dentry *dentry, *root; | |
802 | struct qstr quick_string; | |
803 | char buf[16]; | |
804 | ||
805 | if (!can_do_hugetlb_shm()) | |
806 | return ERR_PTR(-EPERM); | |
807 | ||
808 | if (!is_hugepage_mem_enough(size)) | |
809 | return ERR_PTR(-ENOMEM); | |
810 | ||
811 | if (!user_shm_lock(size, current->user)) | |
812 | return ERR_PTR(-ENOMEM); | |
813 | ||
814 | root = hugetlbfs_vfsmount->mnt_root; | |
815 | snprintf(buf, 16, "%lu", hugetlbfs_counter()); | |
816 | quick_string.name = buf; | |
817 | quick_string.len = strlen(quick_string.name); | |
818 | quick_string.hash = 0; | |
819 | dentry = d_alloc(root, &quick_string); | |
820 | if (!dentry) | |
821 | goto out_shm_unlock; | |
822 | ||
823 | error = -ENFILE; | |
824 | file = get_empty_filp(); | |
825 | if (!file) | |
826 | goto out_dentry; | |
827 | ||
828 | error = -ENOSPC; | |
829 | inode = hugetlbfs_get_inode(root->d_sb, current->fsuid, | |
830 | current->fsgid, S_IFREG | S_IRWXUGO, 0); | |
831 | if (!inode) | |
832 | goto out_file; | |
833 | ||
834 | d_instantiate(dentry, inode); | |
835 | inode->i_size = size; | |
836 | inode->i_nlink = 0; | |
837 | file->f_vfsmnt = mntget(hugetlbfs_vfsmount); | |
838 | file->f_dentry = dentry; | |
839 | file->f_mapping = inode->i_mapping; | |
840 | file->f_op = &hugetlbfs_file_operations; | |
841 | file->f_mode = FMODE_WRITE | FMODE_READ; | |
842 | return file; | |
843 | ||
844 | out_file: | |
845 | put_filp(file); | |
846 | out_dentry: | |
847 | dput(dentry); | |
848 | out_shm_unlock: | |
849 | user_shm_unlock(size, current->user); | |
850 | return ERR_PTR(error); | |
851 | } | |
852 | ||
853 | static int __init init_hugetlbfs_fs(void) | |
854 | { | |
855 | int error; | |
856 | struct vfsmount *vfsmount; | |
857 | ||
858 | hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache", | |
859 | sizeof(struct hugetlbfs_inode_info), | |
860 | 0, 0, init_once, NULL); | |
861 | if (hugetlbfs_inode_cachep == NULL) | |
862 | return -ENOMEM; | |
863 | ||
864 | error = register_filesystem(&hugetlbfs_fs_type); | |
865 | if (error) | |
866 | goto out; | |
867 | ||
868 | vfsmount = kern_mount(&hugetlbfs_fs_type); | |
869 | ||
870 | if (!IS_ERR(vfsmount)) { | |
871 | hugetlbfs_vfsmount = vfsmount; | |
872 | return 0; | |
873 | } | |
874 | ||
875 | error = PTR_ERR(vfsmount); | |
876 | ||
877 | out: | |
878 | if (error) | |
879 | kmem_cache_destroy(hugetlbfs_inode_cachep); | |
880 | return error; | |
881 | } | |
882 | ||
883 | static void __exit exit_hugetlbfs_fs(void) | |
884 | { | |
885 | kmem_cache_destroy(hugetlbfs_inode_cachep); | |
886 | unregister_filesystem(&hugetlbfs_fs_type); | |
887 | } | |
888 | ||
889 | module_init(init_hugetlbfs_fs) | |
890 | module_exit(exit_hugetlbfs_fs) | |
891 | ||
892 | MODULE_LICENSE("GPL"); |