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Commit | Line | Data |
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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/kernel.h> | |
17 | #include <linux/writeback.h> | |
18 | #include <linux/pagemap.h> | |
19 | #include <linux/highmem.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/string.h> | |
22 | #include <linux/capability.h> | |
23 | #include <linux/ctype.h> | |
24 | #include <linux/backing-dev.h> | |
25 | #include <linux/hugetlb.h> | |
26 | #include <linux/pagevec.h> | |
27 | #include <linux/parser.h> | |
28 | #include <linux/mman.h> | |
29 | #include <linux/slab.h> | |
30 | #include <linux/dnotify.h> | |
31 | #include <linux/statfs.h> | |
32 | #include <linux/security.h> | |
33 | #include <linux/ima.h> | |
34 | #include <linux/magic.h> | |
35 | ||
36 | #include <asm/uaccess.h> | |
37 | ||
38 | static const struct super_operations hugetlbfs_ops; | |
39 | static const struct address_space_operations hugetlbfs_aops; | |
40 | const struct file_operations hugetlbfs_file_operations; | |
41 | static const struct inode_operations hugetlbfs_dir_inode_operations; | |
42 | static const struct inode_operations hugetlbfs_inode_operations; | |
43 | ||
44 | static struct backing_dev_info hugetlbfs_backing_dev_info = { | |
45 | .name = "hugetlbfs", | |
46 | .ra_pages = 0, /* No readahead */ | |
47 | .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK, | |
48 | }; | |
49 | ||
50 | int sysctl_hugetlb_shm_group; | |
51 | ||
52 | enum { | |
53 | Opt_size, Opt_nr_inodes, | |
54 | Opt_mode, Opt_uid, Opt_gid, | |
55 | Opt_pagesize, | |
56 | Opt_err, | |
57 | }; | |
58 | ||
59 | static const match_table_t tokens = { | |
60 | {Opt_size, "size=%s"}, | |
61 | {Opt_nr_inodes, "nr_inodes=%s"}, | |
62 | {Opt_mode, "mode=%o"}, | |
63 | {Opt_uid, "uid=%u"}, | |
64 | {Opt_gid, "gid=%u"}, | |
65 | {Opt_pagesize, "pagesize=%s"}, | |
66 | {Opt_err, NULL}, | |
67 | }; | |
68 | ||
69 | static void huge_pagevec_release(struct pagevec *pvec) | |
70 | { | |
71 | int i; | |
72 | ||
73 | for (i = 0; i < pagevec_count(pvec); ++i) | |
74 | put_page(pvec->pages[i]); | |
75 | ||
76 | pagevec_reinit(pvec); | |
77 | } | |
78 | ||
79 | static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma) | |
80 | { | |
81 | struct inode *inode = file->f_path.dentry->d_inode; | |
82 | loff_t len, vma_len; | |
83 | int ret; | |
84 | struct hstate *h = hstate_file(file); | |
85 | ||
86 | /* | |
87 | * vma address alignment (but not the pgoff alignment) has | |
88 | * already been checked by prepare_hugepage_range. If you add | |
89 | * any error returns here, do so after setting VM_HUGETLB, so | |
90 | * is_vm_hugetlb_page tests below unmap_region go the right | |
91 | * way when do_mmap_pgoff unwinds (may be important on powerpc | |
92 | * and ia64). | |
93 | */ | |
94 | vma->vm_flags |= VM_HUGETLB | VM_RESERVED; | |
95 | vma->vm_ops = &hugetlb_vm_ops; | |
96 | ||
97 | if (vma->vm_pgoff & ~(huge_page_mask(h) >> PAGE_SHIFT)) | |
98 | return -EINVAL; | |
99 | ||
100 | vma_len = (loff_t)(vma->vm_end - vma->vm_start); | |
101 | ||
102 | mutex_lock(&inode->i_mutex); | |
103 | file_accessed(file); | |
104 | ||
105 | ret = -ENOMEM; | |
106 | len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
107 | ||
108 | if (hugetlb_reserve_pages(inode, | |
109 | vma->vm_pgoff >> huge_page_order(h), | |
110 | len >> huge_page_shift(h), vma, | |
111 | vma->vm_flags)) | |
112 | goto out; | |
113 | ||
114 | ret = 0; | |
115 | hugetlb_prefault_arch_hook(vma->vm_mm); | |
116 | if (vma->vm_flags & VM_WRITE && inode->i_size < len) | |
117 | inode->i_size = len; | |
118 | out: | |
119 | mutex_unlock(&inode->i_mutex); | |
120 | ||
121 | return ret; | |
122 | } | |
123 | ||
124 | /* | |
125 | * Called under down_write(mmap_sem). | |
126 | */ | |
127 | ||
128 | #ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA | |
129 | static unsigned long | |
130 | hugetlb_get_unmapped_area(struct file *file, unsigned long addr, | |
131 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
132 | { | |
133 | struct mm_struct *mm = current->mm; | |
134 | struct vm_area_struct *vma; | |
135 | unsigned long start_addr; | |
136 | struct hstate *h = hstate_file(file); | |
137 | ||
138 | if (len & ~huge_page_mask(h)) | |
139 | return -EINVAL; | |
140 | if (len > TASK_SIZE) | |
141 | return -ENOMEM; | |
142 | ||
143 | if (flags & MAP_FIXED) { | |
144 | if (prepare_hugepage_range(file, addr, len)) | |
145 | return -EINVAL; | |
146 | return addr; | |
147 | } | |
148 | ||
149 | if (addr) { | |
150 | addr = ALIGN(addr, huge_page_size(h)); | |
151 | vma = find_vma(mm, addr); | |
152 | if (TASK_SIZE - len >= addr && | |
153 | (!vma || addr + len <= vma->vm_start)) | |
154 | return addr; | |
155 | } | |
156 | ||
157 | start_addr = mm->free_area_cache; | |
158 | ||
159 | if (len <= mm->cached_hole_size) | |
160 | start_addr = TASK_UNMAPPED_BASE; | |
161 | ||
162 | full_search: | |
163 | addr = ALIGN(start_addr, huge_page_size(h)); | |
164 | ||
165 | for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { | |
166 | /* At this point: (!vma || addr < vma->vm_end). */ | |
167 | if (TASK_SIZE - len < addr) { | |
168 | /* | |
169 | * Start a new search - just in case we missed | |
170 | * some holes. | |
171 | */ | |
172 | if (start_addr != TASK_UNMAPPED_BASE) { | |
173 | start_addr = TASK_UNMAPPED_BASE; | |
174 | goto full_search; | |
175 | } | |
176 | return -ENOMEM; | |
177 | } | |
178 | ||
179 | if (!vma || addr + len <= vma->vm_start) | |
180 | return addr; | |
181 | addr = ALIGN(vma->vm_end, huge_page_size(h)); | |
182 | } | |
183 | } | |
184 | #endif | |
185 | ||
186 | static int | |
187 | hugetlbfs_read_actor(struct page *page, unsigned long offset, | |
188 | char __user *buf, unsigned long count, | |
189 | unsigned long size) | |
190 | { | |
191 | char *kaddr; | |
192 | unsigned long left, copied = 0; | |
193 | int i, chunksize; | |
194 | ||
195 | if (size > count) | |
196 | size = count; | |
197 | ||
198 | /* Find which 4k chunk and offset with in that chunk */ | |
199 | i = offset >> PAGE_CACHE_SHIFT; | |
200 | offset = offset & ~PAGE_CACHE_MASK; | |
201 | ||
202 | while (size) { | |
203 | chunksize = PAGE_CACHE_SIZE; | |
204 | if (offset) | |
205 | chunksize -= offset; | |
206 | if (chunksize > size) | |
207 | chunksize = size; | |
208 | kaddr = kmap(&page[i]); | |
209 | left = __copy_to_user(buf, kaddr + offset, chunksize); | |
210 | kunmap(&page[i]); | |
211 | if (left) { | |
212 | copied += (chunksize - left); | |
213 | break; | |
214 | } | |
215 | offset = 0; | |
216 | size -= chunksize; | |
217 | buf += chunksize; | |
218 | copied += chunksize; | |
219 | i++; | |
220 | } | |
221 | return copied ? copied : -EFAULT; | |
222 | } | |
223 | ||
224 | /* | |
225 | * Support for read() - Find the page attached to f_mapping and copy out the | |
226 | * data. Its *very* similar to do_generic_mapping_read(), we can't use that | |
227 | * since it has PAGE_CACHE_SIZE assumptions. | |
228 | */ | |
229 | static ssize_t hugetlbfs_read(struct file *filp, char __user *buf, | |
230 | size_t len, loff_t *ppos) | |
231 | { | |
232 | struct hstate *h = hstate_file(filp); | |
233 | struct address_space *mapping = filp->f_mapping; | |
234 | struct inode *inode = mapping->host; | |
235 | unsigned long index = *ppos >> huge_page_shift(h); | |
236 | unsigned long offset = *ppos & ~huge_page_mask(h); | |
237 | unsigned long end_index; | |
238 | loff_t isize; | |
239 | ssize_t retval = 0; | |
240 | ||
241 | mutex_lock(&inode->i_mutex); | |
242 | ||
243 | /* validate length */ | |
244 | if (len == 0) | |
245 | goto out; | |
246 | ||
247 | isize = i_size_read(inode); | |
248 | if (!isize) | |
249 | goto out; | |
250 | ||
251 | end_index = (isize - 1) >> huge_page_shift(h); | |
252 | for (;;) { | |
253 | struct page *page; | |
254 | unsigned long nr, ret; | |
255 | int ra; | |
256 | ||
257 | /* nr is the maximum number of bytes to copy from this page */ | |
258 | nr = huge_page_size(h); | |
259 | if (index >= end_index) { | |
260 | if (index > end_index) | |
261 | goto out; | |
262 | nr = ((isize - 1) & ~huge_page_mask(h)) + 1; | |
263 | if (nr <= offset) { | |
264 | goto out; | |
265 | } | |
266 | } | |
267 | nr = nr - offset; | |
268 | ||
269 | /* Find the page */ | |
270 | page = find_get_page(mapping, index); | |
271 | if (unlikely(page == NULL)) { | |
272 | /* | |
273 | * We have a HOLE, zero out the user-buffer for the | |
274 | * length of the hole or request. | |
275 | */ | |
276 | ret = len < nr ? len : nr; | |
277 | if (clear_user(buf, ret)) | |
278 | ra = -EFAULT; | |
279 | else | |
280 | ra = 0; | |
281 | } else { | |
282 | /* | |
283 | * We have the page, copy it to user space buffer. | |
284 | */ | |
285 | ra = hugetlbfs_read_actor(page, offset, buf, len, nr); | |
286 | ret = ra; | |
287 | } | |
288 | if (ra < 0) { | |
289 | if (retval == 0) | |
290 | retval = ra; | |
291 | if (page) | |
292 | page_cache_release(page); | |
293 | goto out; | |
294 | } | |
295 | ||
296 | offset += ret; | |
297 | retval += ret; | |
298 | len -= ret; | |
299 | index += offset >> huge_page_shift(h); | |
300 | offset &= ~huge_page_mask(h); | |
301 | ||
302 | if (page) | |
303 | page_cache_release(page); | |
304 | ||
305 | /* short read or no more work */ | |
306 | if ((ret != nr) || (len == 0)) | |
307 | break; | |
308 | } | |
309 | out: | |
310 | *ppos = ((loff_t)index << huge_page_shift(h)) + offset; | |
311 | mutex_unlock(&inode->i_mutex); | |
312 | return retval; | |
313 | } | |
314 | ||
315 | static int hugetlbfs_write_begin(struct file *file, | |
316 | struct address_space *mapping, | |
317 | loff_t pos, unsigned len, unsigned flags, | |
318 | struct page **pagep, void **fsdata) | |
319 | { | |
320 | return -EINVAL; | |
321 | } | |
322 | ||
323 | static int hugetlbfs_write_end(struct file *file, struct address_space *mapping, | |
324 | loff_t pos, unsigned len, unsigned copied, | |
325 | struct page *page, void *fsdata) | |
326 | { | |
327 | BUG(); | |
328 | return -EINVAL; | |
329 | } | |
330 | ||
331 | static void truncate_huge_page(struct page *page) | |
332 | { | |
333 | cancel_dirty_page(page, /* No IO accounting for huge pages? */0); | |
334 | ClearPageUptodate(page); | |
335 | remove_from_page_cache(page); | |
336 | put_page(page); | |
337 | } | |
338 | ||
339 | static void truncate_hugepages(struct inode *inode, loff_t lstart) | |
340 | { | |
341 | struct hstate *h = hstate_inode(inode); | |
342 | struct address_space *mapping = &inode->i_data; | |
343 | const pgoff_t start = lstart >> huge_page_shift(h); | |
344 | struct pagevec pvec; | |
345 | pgoff_t next; | |
346 | int i, freed = 0; | |
347 | ||
348 | pagevec_init(&pvec, 0); | |
349 | next = start; | |
350 | while (1) { | |
351 | if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) { | |
352 | if (next == start) | |
353 | break; | |
354 | next = start; | |
355 | continue; | |
356 | } | |
357 | ||
358 | for (i = 0; i < pagevec_count(&pvec); ++i) { | |
359 | struct page *page = pvec.pages[i]; | |
360 | ||
361 | lock_page(page); | |
362 | if (page->index > next) | |
363 | next = page->index; | |
364 | ++next; | |
365 | truncate_huge_page(page); | |
366 | unlock_page(page); | |
367 | freed++; | |
368 | } | |
369 | huge_pagevec_release(&pvec); | |
370 | } | |
371 | BUG_ON(!lstart && mapping->nrpages); | |
372 | hugetlb_unreserve_pages(inode, start, freed); | |
373 | } | |
374 | ||
375 | static void hugetlbfs_delete_inode(struct inode *inode) | |
376 | { | |
377 | truncate_hugepages(inode, 0); | |
378 | clear_inode(inode); | |
379 | } | |
380 | ||
381 | static void hugetlbfs_forget_inode(struct inode *inode) __releases(inode_lock) | |
382 | { | |
383 | struct super_block *sb = inode->i_sb; | |
384 | ||
385 | if (!hlist_unhashed(&inode->i_hash)) { | |
386 | if (!(inode->i_state & (I_DIRTY|I_SYNC))) | |
387 | list_move(&inode->i_list, &inode_unused); | |
388 | inodes_stat.nr_unused++; | |
389 | if (!sb || (sb->s_flags & MS_ACTIVE)) { | |
390 | spin_unlock(&inode_lock); | |
391 | return; | |
392 | } | |
393 | inode->i_state |= I_WILL_FREE; | |
394 | spin_unlock(&inode_lock); | |
395 | /* | |
396 | * write_inode_now is a noop as we set BDI_CAP_NO_WRITEBACK | |
397 | * in our backing_dev_info. | |
398 | */ | |
399 | write_inode_now(inode, 1); | |
400 | spin_lock(&inode_lock); | |
401 | inode->i_state &= ~I_WILL_FREE; | |
402 | inodes_stat.nr_unused--; | |
403 | hlist_del_init(&inode->i_hash); | |
404 | } | |
405 | list_del_init(&inode->i_list); | |
406 | list_del_init(&inode->i_sb_list); | |
407 | inode->i_state |= I_FREEING; | |
408 | inodes_stat.nr_inodes--; | |
409 | spin_unlock(&inode_lock); | |
410 | truncate_hugepages(inode, 0); | |
411 | clear_inode(inode); | |
412 | destroy_inode(inode); | |
413 | } | |
414 | ||
415 | static void hugetlbfs_drop_inode(struct inode *inode) | |
416 | { | |
417 | if (!inode->i_nlink) | |
418 | generic_delete_inode(inode); | |
419 | else | |
420 | hugetlbfs_forget_inode(inode); | |
421 | } | |
422 | ||
423 | static inline void | |
424 | hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff) | |
425 | { | |
426 | struct vm_area_struct *vma; | |
427 | struct prio_tree_iter iter; | |
428 | ||
429 | vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) { | |
430 | unsigned long v_offset; | |
431 | ||
432 | /* | |
433 | * Can the expression below overflow on 32-bit arches? | |
434 | * No, because the prio_tree returns us only those vmas | |
435 | * which overlap the truncated area starting at pgoff, | |
436 | * and no vma on a 32-bit arch can span beyond the 4GB. | |
437 | */ | |
438 | if (vma->vm_pgoff < pgoff) | |
439 | v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT; | |
440 | else | |
441 | v_offset = 0; | |
442 | ||
443 | __unmap_hugepage_range(vma, | |
444 | vma->vm_start + v_offset, vma->vm_end, NULL); | |
445 | } | |
446 | } | |
447 | ||
448 | static int hugetlb_vmtruncate(struct inode *inode, loff_t offset) | |
449 | { | |
450 | pgoff_t pgoff; | |
451 | struct address_space *mapping = inode->i_mapping; | |
452 | struct hstate *h = hstate_inode(inode); | |
453 | ||
454 | BUG_ON(offset & ~huge_page_mask(h)); | |
455 | pgoff = offset >> PAGE_SHIFT; | |
456 | ||
457 | i_size_write(inode, offset); | |
458 | spin_lock(&mapping->i_mmap_lock); | |
459 | if (!prio_tree_empty(&mapping->i_mmap)) | |
460 | hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff); | |
461 | spin_unlock(&mapping->i_mmap_lock); | |
462 | truncate_hugepages(inode, offset); | |
463 | return 0; | |
464 | } | |
465 | ||
466 | static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr) | |
467 | { | |
468 | struct inode *inode = dentry->d_inode; | |
469 | struct hstate *h = hstate_inode(inode); | |
470 | int error; | |
471 | unsigned int ia_valid = attr->ia_valid; | |
472 | ||
473 | BUG_ON(!inode); | |
474 | ||
475 | error = inode_change_ok(inode, attr); | |
476 | if (error) | |
477 | goto out; | |
478 | ||
479 | if (ia_valid & ATTR_SIZE) { | |
480 | error = -EINVAL; | |
481 | if (!(attr->ia_size & ~huge_page_mask(h))) | |
482 | error = hugetlb_vmtruncate(inode, attr->ia_size); | |
483 | if (error) | |
484 | goto out; | |
485 | attr->ia_valid &= ~ATTR_SIZE; | |
486 | } | |
487 | error = inode_setattr(inode, attr); | |
488 | out: | |
489 | return error; | |
490 | } | |
491 | ||
492 | static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid, | |
493 | gid_t gid, int mode, dev_t dev) | |
494 | { | |
495 | struct inode *inode; | |
496 | ||
497 | inode = new_inode(sb); | |
498 | if (inode) { | |
499 | struct hugetlbfs_inode_info *info; | |
500 | inode->i_mode = mode; | |
501 | inode->i_uid = uid; | |
502 | inode->i_gid = gid; | |
503 | inode->i_mapping->a_ops = &hugetlbfs_aops; | |
504 | inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info; | |
505 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
506 | INIT_LIST_HEAD(&inode->i_mapping->private_list); | |
507 | info = HUGETLBFS_I(inode); | |
508 | /* | |
509 | * The policy is initialized here even if we are creating a | |
510 | * private inode because initialization simply creates an | |
511 | * an empty rb tree and calls spin_lock_init(), later when we | |
512 | * call mpol_free_shared_policy() it will just return because | |
513 | * the rb tree will still be empty. | |
514 | */ | |
515 | mpol_shared_policy_init(&info->policy, NULL); | |
516 | switch (mode & S_IFMT) { | |
517 | default: | |
518 | init_special_inode(inode, mode, dev); | |
519 | break; | |
520 | case S_IFREG: | |
521 | inode->i_op = &hugetlbfs_inode_operations; | |
522 | inode->i_fop = &hugetlbfs_file_operations; | |
523 | break; | |
524 | case S_IFDIR: | |
525 | inode->i_op = &hugetlbfs_dir_inode_operations; | |
526 | inode->i_fop = &simple_dir_operations; | |
527 | ||
528 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ | |
529 | inc_nlink(inode); | |
530 | break; | |
531 | case S_IFLNK: | |
532 | inode->i_op = &page_symlink_inode_operations; | |
533 | break; | |
534 | } | |
535 | } | |
536 | return inode; | |
537 | } | |
538 | ||
539 | /* | |
540 | * File creation. Allocate an inode, and we're done.. | |
541 | */ | |
542 | static int hugetlbfs_mknod(struct inode *dir, | |
543 | struct dentry *dentry, int mode, dev_t dev) | |
544 | { | |
545 | struct inode *inode; | |
546 | int error = -ENOSPC; | |
547 | gid_t gid; | |
548 | ||
549 | if (dir->i_mode & S_ISGID) { | |
550 | gid = dir->i_gid; | |
551 | if (S_ISDIR(mode)) | |
552 | mode |= S_ISGID; | |
553 | } else { | |
554 | gid = current_fsgid(); | |
555 | } | |
556 | inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), gid, mode, dev); | |
557 | if (inode) { | |
558 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
559 | d_instantiate(dentry, inode); | |
560 | dget(dentry); /* Extra count - pin the dentry in core */ | |
561 | error = 0; | |
562 | } | |
563 | return error; | |
564 | } | |
565 | ||
566 | static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
567 | { | |
568 | int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0); | |
569 | if (!retval) | |
570 | inc_nlink(dir); | |
571 | return retval; | |
572 | } | |
573 | ||
574 | static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) | |
575 | { | |
576 | return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0); | |
577 | } | |
578 | ||
579 | static int hugetlbfs_symlink(struct inode *dir, | |
580 | struct dentry *dentry, const char *symname) | |
581 | { | |
582 | struct inode *inode; | |
583 | int error = -ENOSPC; | |
584 | gid_t gid; | |
585 | ||
586 | if (dir->i_mode & S_ISGID) | |
587 | gid = dir->i_gid; | |
588 | else | |
589 | gid = current_fsgid(); | |
590 | ||
591 | inode = hugetlbfs_get_inode(dir->i_sb, current_fsuid(), | |
592 | gid, S_IFLNK|S_IRWXUGO, 0); | |
593 | if (inode) { | |
594 | int l = strlen(symname)+1; | |
595 | error = page_symlink(inode, symname, l); | |
596 | if (!error) { | |
597 | d_instantiate(dentry, inode); | |
598 | dget(dentry); | |
599 | } else | |
600 | iput(inode); | |
601 | } | |
602 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
603 | ||
604 | return error; | |
605 | } | |
606 | ||
607 | /* | |
608 | * mark the head page dirty | |
609 | */ | |
610 | static int hugetlbfs_set_page_dirty(struct page *page) | |
611 | { | |
612 | struct page *head = compound_head(page); | |
613 | ||
614 | SetPageDirty(head); | |
615 | return 0; | |
616 | } | |
617 | ||
618 | static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf) | |
619 | { | |
620 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb); | |
621 | struct hstate *h = hstate_inode(dentry->d_inode); | |
622 | ||
623 | buf->f_type = HUGETLBFS_MAGIC; | |
624 | buf->f_bsize = huge_page_size(h); | |
625 | if (sbinfo) { | |
626 | spin_lock(&sbinfo->stat_lock); | |
627 | /* If no limits set, just report 0 for max/free/used | |
628 | * blocks, like simple_statfs() */ | |
629 | if (sbinfo->max_blocks >= 0) { | |
630 | buf->f_blocks = sbinfo->max_blocks; | |
631 | buf->f_bavail = buf->f_bfree = sbinfo->free_blocks; | |
632 | buf->f_files = sbinfo->max_inodes; | |
633 | buf->f_ffree = sbinfo->free_inodes; | |
634 | } | |
635 | spin_unlock(&sbinfo->stat_lock); | |
636 | } | |
637 | buf->f_namelen = NAME_MAX; | |
638 | return 0; | |
639 | } | |
640 | ||
641 | static void hugetlbfs_put_super(struct super_block *sb) | |
642 | { | |
643 | struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb); | |
644 | ||
645 | if (sbi) { | |
646 | sb->s_fs_info = NULL; | |
647 | kfree(sbi); | |
648 | } | |
649 | } | |
650 | ||
651 | static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo) | |
652 | { | |
653 | if (sbinfo->free_inodes >= 0) { | |
654 | spin_lock(&sbinfo->stat_lock); | |
655 | if (unlikely(!sbinfo->free_inodes)) { | |
656 | spin_unlock(&sbinfo->stat_lock); | |
657 | return 0; | |
658 | } | |
659 | sbinfo->free_inodes--; | |
660 | spin_unlock(&sbinfo->stat_lock); | |
661 | } | |
662 | ||
663 | return 1; | |
664 | } | |
665 | ||
666 | static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo) | |
667 | { | |
668 | if (sbinfo->free_inodes >= 0) { | |
669 | spin_lock(&sbinfo->stat_lock); | |
670 | sbinfo->free_inodes++; | |
671 | spin_unlock(&sbinfo->stat_lock); | |
672 | } | |
673 | } | |
674 | ||
675 | ||
676 | static struct kmem_cache *hugetlbfs_inode_cachep; | |
677 | ||
678 | static struct inode *hugetlbfs_alloc_inode(struct super_block *sb) | |
679 | { | |
680 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); | |
681 | struct hugetlbfs_inode_info *p; | |
682 | ||
683 | if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo))) | |
684 | return NULL; | |
685 | p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL); | |
686 | if (unlikely(!p)) { | |
687 | hugetlbfs_inc_free_inodes(sbinfo); | |
688 | return NULL; | |
689 | } | |
690 | return &p->vfs_inode; | |
691 | } | |
692 | ||
693 | static void hugetlbfs_destroy_inode(struct inode *inode) | |
694 | { | |
695 | hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb)); | |
696 | mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy); | |
697 | kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode)); | |
698 | } | |
699 | ||
700 | static const struct address_space_operations hugetlbfs_aops = { | |
701 | .write_begin = hugetlbfs_write_begin, | |
702 | .write_end = hugetlbfs_write_end, | |
703 | .set_page_dirty = hugetlbfs_set_page_dirty, | |
704 | }; | |
705 | ||
706 | ||
707 | static void init_once(void *foo) | |
708 | { | |
709 | struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo; | |
710 | ||
711 | inode_init_once(&ei->vfs_inode); | |
712 | } | |
713 | ||
714 | const struct file_operations hugetlbfs_file_operations = { | |
715 | .read = hugetlbfs_read, | |
716 | .mmap = hugetlbfs_file_mmap, | |
717 | .fsync = simple_sync_file, | |
718 | .get_unmapped_area = hugetlb_get_unmapped_area, | |
719 | }; | |
720 | ||
721 | static const struct inode_operations hugetlbfs_dir_inode_operations = { | |
722 | .create = hugetlbfs_create, | |
723 | .lookup = simple_lookup, | |
724 | .link = simple_link, | |
725 | .unlink = simple_unlink, | |
726 | .symlink = hugetlbfs_symlink, | |
727 | .mkdir = hugetlbfs_mkdir, | |
728 | .rmdir = simple_rmdir, | |
729 | .mknod = hugetlbfs_mknod, | |
730 | .rename = simple_rename, | |
731 | .setattr = hugetlbfs_setattr, | |
732 | }; | |
733 | ||
734 | static const struct inode_operations hugetlbfs_inode_operations = { | |
735 | .setattr = hugetlbfs_setattr, | |
736 | }; | |
737 | ||
738 | static const struct super_operations hugetlbfs_ops = { | |
739 | .alloc_inode = hugetlbfs_alloc_inode, | |
740 | .destroy_inode = hugetlbfs_destroy_inode, | |
741 | .statfs = hugetlbfs_statfs, | |
742 | .delete_inode = hugetlbfs_delete_inode, | |
743 | .drop_inode = hugetlbfs_drop_inode, | |
744 | .put_super = hugetlbfs_put_super, | |
745 | .show_options = generic_show_options, | |
746 | }; | |
747 | ||
748 | static int | |
749 | hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig) | |
750 | { | |
751 | char *p, *rest; | |
752 | substring_t args[MAX_OPT_ARGS]; | |
753 | int option; | |
754 | unsigned long long size = 0; | |
755 | enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = NO_SIZE; | |
756 | ||
757 | if (!options) | |
758 | return 0; | |
759 | ||
760 | while ((p = strsep(&options, ",")) != NULL) { | |
761 | int token; | |
762 | if (!*p) | |
763 | continue; | |
764 | ||
765 | token = match_token(p, tokens, args); | |
766 | switch (token) { | |
767 | case Opt_uid: | |
768 | if (match_int(&args[0], &option)) | |
769 | goto bad_val; | |
770 | pconfig->uid = option; | |
771 | break; | |
772 | ||
773 | case Opt_gid: | |
774 | if (match_int(&args[0], &option)) | |
775 | goto bad_val; | |
776 | pconfig->gid = option; | |
777 | break; | |
778 | ||
779 | case Opt_mode: | |
780 | if (match_octal(&args[0], &option)) | |
781 | goto bad_val; | |
782 | pconfig->mode = option & 01777U; | |
783 | break; | |
784 | ||
785 | case Opt_size: { | |
786 | /* memparse() will accept a K/M/G without a digit */ | |
787 | if (!isdigit(*args[0].from)) | |
788 | goto bad_val; | |
789 | size = memparse(args[0].from, &rest); | |
790 | setsize = SIZE_STD; | |
791 | if (*rest == '%') | |
792 | setsize = SIZE_PERCENT; | |
793 | break; | |
794 | } | |
795 | ||
796 | case Opt_nr_inodes: | |
797 | /* memparse() will accept a K/M/G without a digit */ | |
798 | if (!isdigit(*args[0].from)) | |
799 | goto bad_val; | |
800 | pconfig->nr_inodes = memparse(args[0].from, &rest); | |
801 | break; | |
802 | ||
803 | case Opt_pagesize: { | |
804 | unsigned long ps; | |
805 | ps = memparse(args[0].from, &rest); | |
806 | pconfig->hstate = size_to_hstate(ps); | |
807 | if (!pconfig->hstate) { | |
808 | printk(KERN_ERR | |
809 | "hugetlbfs: Unsupported page size %lu MB\n", | |
810 | ps >> 20); | |
811 | return -EINVAL; | |
812 | } | |
813 | break; | |
814 | } | |
815 | ||
816 | default: | |
817 | printk(KERN_ERR "hugetlbfs: Bad mount option: \"%s\"\n", | |
818 | p); | |
819 | return -EINVAL; | |
820 | break; | |
821 | } | |
822 | } | |
823 | ||
824 | /* Do size after hstate is set up */ | |
825 | if (setsize > NO_SIZE) { | |
826 | struct hstate *h = pconfig->hstate; | |
827 | if (setsize == SIZE_PERCENT) { | |
828 | size <<= huge_page_shift(h); | |
829 | size *= h->max_huge_pages; | |
830 | do_div(size, 100); | |
831 | } | |
832 | pconfig->nr_blocks = (size >> huge_page_shift(h)); | |
833 | } | |
834 | ||
835 | return 0; | |
836 | ||
837 | bad_val: | |
838 | printk(KERN_ERR "hugetlbfs: Bad value '%s' for mount option '%s'\n", | |
839 | args[0].from, p); | |
840 | return -EINVAL; | |
841 | } | |
842 | ||
843 | static int | |
844 | hugetlbfs_fill_super(struct super_block *sb, void *data, int silent) | |
845 | { | |
846 | struct inode * inode; | |
847 | struct dentry * root; | |
848 | int ret; | |
849 | struct hugetlbfs_config config; | |
850 | struct hugetlbfs_sb_info *sbinfo; | |
851 | ||
852 | save_mount_options(sb, data); | |
853 | ||
854 | config.nr_blocks = -1; /* No limit on size by default */ | |
855 | config.nr_inodes = -1; /* No limit on number of inodes by default */ | |
856 | config.uid = current_fsuid(); | |
857 | config.gid = current_fsgid(); | |
858 | config.mode = 0755; | |
859 | config.hstate = &default_hstate; | |
860 | ret = hugetlbfs_parse_options(data, &config); | |
861 | if (ret) | |
862 | return ret; | |
863 | ||
864 | sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL); | |
865 | if (!sbinfo) | |
866 | return -ENOMEM; | |
867 | sb->s_fs_info = sbinfo; | |
868 | sbinfo->hstate = config.hstate; | |
869 | spin_lock_init(&sbinfo->stat_lock); | |
870 | sbinfo->max_blocks = config.nr_blocks; | |
871 | sbinfo->free_blocks = config.nr_blocks; | |
872 | sbinfo->max_inodes = config.nr_inodes; | |
873 | sbinfo->free_inodes = config.nr_inodes; | |
874 | sb->s_maxbytes = MAX_LFS_FILESIZE; | |
875 | sb->s_blocksize = huge_page_size(config.hstate); | |
876 | sb->s_blocksize_bits = huge_page_shift(config.hstate); | |
877 | sb->s_magic = HUGETLBFS_MAGIC; | |
878 | sb->s_op = &hugetlbfs_ops; | |
879 | sb->s_time_gran = 1; | |
880 | inode = hugetlbfs_get_inode(sb, config.uid, config.gid, | |
881 | S_IFDIR | config.mode, 0); | |
882 | if (!inode) | |
883 | goto out_free; | |
884 | ||
885 | root = d_alloc_root(inode); | |
886 | if (!root) { | |
887 | iput(inode); | |
888 | goto out_free; | |
889 | } | |
890 | sb->s_root = root; | |
891 | return 0; | |
892 | out_free: | |
893 | kfree(sbinfo); | |
894 | return -ENOMEM; | |
895 | } | |
896 | ||
897 | int hugetlb_get_quota(struct address_space *mapping, long delta) | |
898 | { | |
899 | int ret = 0; | |
900 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); | |
901 | ||
902 | if (sbinfo->free_blocks > -1) { | |
903 | spin_lock(&sbinfo->stat_lock); | |
904 | if (sbinfo->free_blocks - delta >= 0) | |
905 | sbinfo->free_blocks -= delta; | |
906 | else | |
907 | ret = -ENOMEM; | |
908 | spin_unlock(&sbinfo->stat_lock); | |
909 | } | |
910 | ||
911 | return ret; | |
912 | } | |
913 | ||
914 | void hugetlb_put_quota(struct address_space *mapping, long delta) | |
915 | { | |
916 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); | |
917 | ||
918 | if (sbinfo->free_blocks > -1) { | |
919 | spin_lock(&sbinfo->stat_lock); | |
920 | sbinfo->free_blocks += delta; | |
921 | spin_unlock(&sbinfo->stat_lock); | |
922 | } | |
923 | } | |
924 | ||
925 | static int hugetlbfs_get_sb(struct file_system_type *fs_type, | |
926 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) | |
927 | { | |
928 | return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super, mnt); | |
929 | } | |
930 | ||
931 | static struct file_system_type hugetlbfs_fs_type = { | |
932 | .name = "hugetlbfs", | |
933 | .get_sb = hugetlbfs_get_sb, | |
934 | .kill_sb = kill_litter_super, | |
935 | }; | |
936 | ||
937 | static struct vfsmount *hugetlbfs_vfsmount; | |
938 | ||
939 | static int can_do_hugetlb_shm(int creat_flags) | |
940 | { | |
941 | if (creat_flags != HUGETLB_SHMFS_INODE) | |
942 | return 0; | |
943 | if (capable(CAP_IPC_LOCK)) | |
944 | return 1; | |
945 | if (in_group_p(sysctl_hugetlb_shm_group)) | |
946 | return 1; | |
947 | return 0; | |
948 | } | |
949 | ||
950 | struct file *hugetlb_file_setup(const char *name, size_t size, int acctflag, | |
951 | struct user_struct **user, int creat_flags) | |
952 | { | |
953 | int error = -ENOMEM; | |
954 | struct file *file; | |
955 | struct inode *inode; | |
956 | struct dentry *dentry, *root; | |
957 | struct qstr quick_string; | |
958 | ||
959 | *user = NULL; | |
960 | if (!hugetlbfs_vfsmount) | |
961 | return ERR_PTR(-ENOENT); | |
962 | ||
963 | if (!can_do_hugetlb_shm(creat_flags)) { | |
964 | *user = current_user(); | |
965 | if (user_shm_lock(size, *user)) { | |
966 | WARN_ONCE(1, | |
967 | "Using mlock ulimits for SHM_HUGETLB deprecated\n"); | |
968 | } else { | |
969 | *user = NULL; | |
970 | return ERR_PTR(-EPERM); | |
971 | } | |
972 | } | |
973 | ||
974 | root = hugetlbfs_vfsmount->mnt_root; | |
975 | quick_string.name = name; | |
976 | quick_string.len = strlen(quick_string.name); | |
977 | quick_string.hash = 0; | |
978 | dentry = d_alloc(root, &quick_string); | |
979 | if (!dentry) | |
980 | goto out_shm_unlock; | |
981 | ||
982 | error = -ENOSPC; | |
983 | inode = hugetlbfs_get_inode(root->d_sb, current_fsuid(), | |
984 | current_fsgid(), S_IFREG | S_IRWXUGO, 0); | |
985 | if (!inode) | |
986 | goto out_dentry; | |
987 | ||
988 | error = -ENOMEM; | |
989 | if (hugetlb_reserve_pages(inode, 0, | |
990 | size >> huge_page_shift(hstate_inode(inode)), NULL, | |
991 | acctflag)) | |
992 | goto out_inode; | |
993 | ||
994 | d_instantiate(dentry, inode); | |
995 | inode->i_size = size; | |
996 | inode->i_nlink = 0; | |
997 | ||
998 | error = -ENFILE; | |
999 | file = alloc_file(hugetlbfs_vfsmount, dentry, | |
1000 | FMODE_WRITE | FMODE_READ, | |
1001 | &hugetlbfs_file_operations); | |
1002 | if (!file) | |
1003 | goto out_dentry; /* inode is already attached */ | |
1004 | ima_counts_get(file); | |
1005 | ||
1006 | return file; | |
1007 | ||
1008 | out_inode: | |
1009 | iput(inode); | |
1010 | out_dentry: | |
1011 | dput(dentry); | |
1012 | out_shm_unlock: | |
1013 | if (*user) { | |
1014 | user_shm_unlock(size, *user); | |
1015 | *user = NULL; | |
1016 | } | |
1017 | return ERR_PTR(error); | |
1018 | } | |
1019 | ||
1020 | static int __init init_hugetlbfs_fs(void) | |
1021 | { | |
1022 | int error; | |
1023 | struct vfsmount *vfsmount; | |
1024 | ||
1025 | error = bdi_init(&hugetlbfs_backing_dev_info); | |
1026 | if (error) | |
1027 | return error; | |
1028 | ||
1029 | hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache", | |
1030 | sizeof(struct hugetlbfs_inode_info), | |
1031 | 0, 0, init_once); | |
1032 | if (hugetlbfs_inode_cachep == NULL) | |
1033 | goto out2; | |
1034 | ||
1035 | error = register_filesystem(&hugetlbfs_fs_type); | |
1036 | if (error) | |
1037 | goto out; | |
1038 | ||
1039 | vfsmount = kern_mount(&hugetlbfs_fs_type); | |
1040 | ||
1041 | if (!IS_ERR(vfsmount)) { | |
1042 | hugetlbfs_vfsmount = vfsmount; | |
1043 | return 0; | |
1044 | } | |
1045 | ||
1046 | error = PTR_ERR(vfsmount); | |
1047 | ||
1048 | out: | |
1049 | if (error) | |
1050 | kmem_cache_destroy(hugetlbfs_inode_cachep); | |
1051 | out2: | |
1052 | bdi_destroy(&hugetlbfs_backing_dev_info); | |
1053 | return error; | |
1054 | } | |
1055 | ||
1056 | static void __exit exit_hugetlbfs_fs(void) | |
1057 | { | |
1058 | kmem_cache_destroy(hugetlbfs_inode_cachep); | |
1059 | unregister_filesystem(&hugetlbfs_fs_type); | |
1060 | bdi_destroy(&hugetlbfs_backing_dev_info); | |
1061 | } | |
1062 | ||
1063 | module_init(init_hugetlbfs_fs) | |
1064 | module_exit(exit_hugetlbfs_fs) | |
1065 | ||
1066 | MODULE_LICENSE("GPL"); |