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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; | |
f5e54d6e | 37 | static const struct address_space_operations hugetlbfs_aops; |
4b6f5d20 | 38 | const struct file_operations hugetlbfs_file_operations; |
1da177e4 LT |
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 | ||
1da177e4 LT |
59 | static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma) |
60 | { | |
61 | struct inode *inode = file->f_dentry->d_inode; | |
1da177e4 LT |
62 | loff_t len, vma_len; |
63 | int ret; | |
64 | ||
1da177e4 LT |
65 | if (vma->vm_pgoff & (HPAGE_SIZE / PAGE_SIZE - 1)) |
66 | return -EINVAL; | |
67 | ||
68 | if (vma->vm_start & ~HPAGE_MASK) | |
69 | return -EINVAL; | |
70 | ||
71 | if (vma->vm_end & ~HPAGE_MASK) | |
72 | return -EINVAL; | |
73 | ||
74 | if (vma->vm_end - vma->vm_start < HPAGE_SIZE) | |
75 | return -EINVAL; | |
76 | ||
77 | vma_len = (loff_t)(vma->vm_end - vma->vm_start); | |
78 | ||
1b1dcc1b | 79 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
80 | file_accessed(file); |
81 | vma->vm_flags |= VM_HUGETLB | VM_RESERVED; | |
82 | vma->vm_ops = &hugetlb_vm_ops; | |
83 | ||
84 | ret = -ENOMEM; | |
85 | len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
86 | if (!(vma->vm_flags & VM_WRITE) && len > inode->i_size) | |
87 | goto out; | |
88 | ||
a43a8c39 KC |
89 | if (vma->vm_flags & VM_MAYSHARE && |
90 | hugetlb_reserve_pages(inode, vma->vm_pgoff >> (HPAGE_SHIFT-PAGE_SHIFT), | |
91 | len >> HPAGE_SHIFT)) | |
92 | goto out; | |
b45b5bd6 | 93 | |
4c887265 AL |
94 | ret = 0; |
95 | hugetlb_prefault_arch_hook(vma->vm_mm); | |
1da177e4 LT |
96 | if (inode->i_size < len) |
97 | inode->i_size = len; | |
98 | out: | |
1b1dcc1b | 99 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
100 | |
101 | return ret; | |
102 | } | |
103 | ||
104 | /* | |
508034a3 | 105 | * Called under down_write(mmap_sem). |
1da177e4 LT |
106 | */ |
107 | ||
108 | #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA | |
109 | unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, | |
110 | unsigned long len, unsigned long pgoff, unsigned long flags); | |
111 | #else | |
112 | static unsigned long | |
113 | hugetlb_get_unmapped_area(struct file *file, unsigned long addr, | |
114 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
115 | { | |
116 | struct mm_struct *mm = current->mm; | |
117 | struct vm_area_struct *vma; | |
118 | unsigned long start_addr; | |
119 | ||
120 | if (len & ~HPAGE_MASK) | |
121 | return -EINVAL; | |
122 | if (len > TASK_SIZE) | |
123 | return -ENOMEM; | |
124 | ||
125 | if (addr) { | |
126 | addr = ALIGN(addr, HPAGE_SIZE); | |
127 | vma = find_vma(mm, addr); | |
128 | if (TASK_SIZE - len >= addr && | |
129 | (!vma || addr + len <= vma->vm_start)) | |
130 | return addr; | |
131 | } | |
132 | ||
133 | start_addr = mm->free_area_cache; | |
134 | ||
1363c3cd WW |
135 | if (len <= mm->cached_hole_size) |
136 | start_addr = TASK_UNMAPPED_BASE; | |
137 | ||
1da177e4 LT |
138 | full_search: |
139 | addr = ALIGN(start_addr, HPAGE_SIZE); | |
140 | ||
141 | for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { | |
142 | /* At this point: (!vma || addr < vma->vm_end). */ | |
143 | if (TASK_SIZE - len < addr) { | |
144 | /* | |
145 | * Start a new search - just in case we missed | |
146 | * some holes. | |
147 | */ | |
148 | if (start_addr != TASK_UNMAPPED_BASE) { | |
149 | start_addr = TASK_UNMAPPED_BASE; | |
150 | goto full_search; | |
151 | } | |
152 | return -ENOMEM; | |
153 | } | |
154 | ||
155 | if (!vma || addr + len <= vma->vm_start) | |
156 | return addr; | |
157 | addr = ALIGN(vma->vm_end, HPAGE_SIZE); | |
158 | } | |
159 | } | |
160 | #endif | |
161 | ||
162 | /* | |
163 | * Read a page. Again trivial. If it didn't already exist | |
164 | * in the page cache, it is zero-filled. | |
165 | */ | |
166 | static int hugetlbfs_readpage(struct file *file, struct page * page) | |
167 | { | |
168 | unlock_page(page); | |
169 | return -EINVAL; | |
170 | } | |
171 | ||
172 | static int hugetlbfs_prepare_write(struct file *file, | |
173 | struct page *page, unsigned offset, unsigned to) | |
174 | { | |
175 | return -EINVAL; | |
176 | } | |
177 | ||
178 | static int hugetlbfs_commit_write(struct file *file, | |
179 | struct page *page, unsigned offset, unsigned to) | |
180 | { | |
181 | return -EINVAL; | |
182 | } | |
183 | ||
1da177e4 LT |
184 | static void truncate_huge_page(struct page *page) |
185 | { | |
186 | clear_page_dirty(page); | |
187 | ClearPageUptodate(page); | |
188 | remove_from_page_cache(page); | |
189 | put_page(page); | |
190 | } | |
191 | ||
b45b5bd6 | 192 | static void truncate_hugepages(struct inode *inode, loff_t lstart) |
1da177e4 | 193 | { |
b45b5bd6 | 194 | struct address_space *mapping = &inode->i_data; |
1da177e4 LT |
195 | const pgoff_t start = lstart >> HPAGE_SHIFT; |
196 | struct pagevec pvec; | |
197 | pgoff_t next; | |
a43a8c39 | 198 | int i, freed = 0; |
1da177e4 LT |
199 | |
200 | pagevec_init(&pvec, 0); | |
201 | next = start; | |
202 | while (1) { | |
203 | if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) { | |
204 | if (next == start) | |
205 | break; | |
206 | next = start; | |
207 | continue; | |
208 | } | |
209 | ||
210 | for (i = 0; i < pagevec_count(&pvec); ++i) { | |
211 | struct page *page = pvec.pages[i]; | |
212 | ||
213 | lock_page(page); | |
214 | if (page->index > next) | |
215 | next = page->index; | |
216 | ++next; | |
217 | truncate_huge_page(page); | |
218 | unlock_page(page); | |
219 | hugetlb_put_quota(mapping); | |
a43a8c39 | 220 | freed++; |
1da177e4 LT |
221 | } |
222 | huge_pagevec_release(&pvec); | |
223 | } | |
224 | BUG_ON(!lstart && mapping->nrpages); | |
a43a8c39 | 225 | hugetlb_unreserve_pages(inode, start, freed); |
1da177e4 LT |
226 | } |
227 | ||
228 | static void hugetlbfs_delete_inode(struct inode *inode) | |
229 | { | |
b45b5bd6 | 230 | truncate_hugepages(inode, 0); |
149f4211 CH |
231 | clear_inode(inode); |
232 | } | |
233 | ||
1da177e4 LT |
234 | static void hugetlbfs_forget_inode(struct inode *inode) |
235 | { | |
0b1533f6 CH |
236 | struct super_block *sb = inode->i_sb; |
237 | ||
238 | if (!hlist_unhashed(&inode->i_hash)) { | |
239 | if (!(inode->i_state & (I_DIRTY|I_LOCK))) | |
240 | list_move(&inode->i_list, &inode_unused); | |
241 | inodes_stat.nr_unused++; | |
242 | if (!sb || (sb->s_flags & MS_ACTIVE)) { | |
243 | spin_unlock(&inode_lock); | |
244 | return; | |
245 | } | |
246 | inode->i_state |= I_WILL_FREE; | |
1da177e4 | 247 | spin_unlock(&inode_lock); |
0b1533f6 CH |
248 | /* |
249 | * write_inode_now is a noop as we set BDI_CAP_NO_WRITEBACK | |
250 | * in our backing_dev_info. | |
251 | */ | |
252 | write_inode_now(inode, 1); | |
253 | spin_lock(&inode_lock); | |
254 | inode->i_state &= ~I_WILL_FREE; | |
255 | inodes_stat.nr_unused--; | |
256 | hlist_del_init(&inode->i_hash); | |
1da177e4 | 257 | } |
1da177e4 LT |
258 | list_del_init(&inode->i_list); |
259 | list_del_init(&inode->i_sb_list); | |
260 | inode->i_state |= I_FREEING; | |
261 | inodes_stat.nr_inodes--; | |
262 | spin_unlock(&inode_lock); | |
b45b5bd6 | 263 | truncate_hugepages(inode, 0); |
1da177e4 LT |
264 | clear_inode(inode); |
265 | destroy_inode(inode); | |
266 | } | |
267 | ||
268 | static void hugetlbfs_drop_inode(struct inode *inode) | |
269 | { | |
270 | if (!inode->i_nlink) | |
6b09b9df | 271 | generic_delete_inode(inode); |
1da177e4 LT |
272 | else |
273 | hugetlbfs_forget_inode(inode); | |
274 | } | |
275 | ||
276 | /* | |
277 | * h_pgoff is in HPAGE_SIZE units. | |
278 | * vma->vm_pgoff is in PAGE_SIZE units. | |
279 | */ | |
280 | static inline void | |
281 | hugetlb_vmtruncate_list(struct prio_tree_root *root, unsigned long h_pgoff) | |
282 | { | |
283 | struct vm_area_struct *vma; | |
284 | struct prio_tree_iter iter; | |
285 | ||
286 | vma_prio_tree_foreach(vma, &iter, root, h_pgoff, ULONG_MAX) { | |
287 | unsigned long h_vm_pgoff; | |
1da177e4 LT |
288 | unsigned long v_offset; |
289 | ||
290 | h_vm_pgoff = vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT); | |
291 | v_offset = (h_pgoff - h_vm_pgoff) << HPAGE_SHIFT; | |
292 | /* | |
293 | * Is this VMA fully outside the truncation point? | |
294 | */ | |
295 | if (h_vm_pgoff >= h_pgoff) | |
296 | v_offset = 0; | |
297 | ||
508034a3 HD |
298 | unmap_hugepage_range(vma, |
299 | vma->vm_start + v_offset, vma->vm_end); | |
1da177e4 LT |
300 | } |
301 | } | |
302 | ||
303 | /* | |
304 | * Expanding truncates are not allowed. | |
305 | */ | |
306 | static int hugetlb_vmtruncate(struct inode *inode, loff_t offset) | |
307 | { | |
308 | unsigned long pgoff; | |
309 | struct address_space *mapping = inode->i_mapping; | |
310 | ||
311 | if (offset > inode->i_size) | |
312 | return -EINVAL; | |
313 | ||
314 | BUG_ON(offset & ~HPAGE_MASK); | |
315 | pgoff = offset >> HPAGE_SHIFT; | |
316 | ||
317 | inode->i_size = offset; | |
318 | spin_lock(&mapping->i_mmap_lock); | |
319 | if (!prio_tree_empty(&mapping->i_mmap)) | |
320 | hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff); | |
321 | spin_unlock(&mapping->i_mmap_lock); | |
b45b5bd6 | 322 | truncate_hugepages(inode, offset); |
1da177e4 LT |
323 | return 0; |
324 | } | |
325 | ||
326 | static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr) | |
327 | { | |
328 | struct inode *inode = dentry->d_inode; | |
329 | int error; | |
330 | unsigned int ia_valid = attr->ia_valid; | |
331 | ||
332 | BUG_ON(!inode); | |
333 | ||
334 | error = inode_change_ok(inode, attr); | |
335 | if (error) | |
336 | goto out; | |
337 | ||
338 | if (ia_valid & ATTR_SIZE) { | |
339 | error = -EINVAL; | |
340 | if (!(attr->ia_size & ~HPAGE_MASK)) | |
341 | error = hugetlb_vmtruncate(inode, attr->ia_size); | |
342 | if (error) | |
343 | goto out; | |
344 | attr->ia_valid &= ~ATTR_SIZE; | |
345 | } | |
346 | error = inode_setattr(inode, attr); | |
347 | out: | |
348 | return error; | |
349 | } | |
350 | ||
351 | static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid, | |
352 | gid_t gid, int mode, dev_t dev) | |
353 | { | |
354 | struct inode *inode; | |
1da177e4 LT |
355 | |
356 | inode = new_inode(sb); | |
357 | if (inode) { | |
358 | struct hugetlbfs_inode_info *info; | |
359 | inode->i_mode = mode; | |
360 | inode->i_uid = uid; | |
361 | inode->i_gid = gid; | |
362 | inode->i_blksize = HPAGE_SIZE; | |
363 | inode->i_blocks = 0; | |
364 | inode->i_mapping->a_ops = &hugetlbfs_aops; | |
365 | inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info; | |
366 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
a43a8c39 | 367 | INIT_LIST_HEAD(&inode->i_mapping->private_list); |
1da177e4 | 368 | info = HUGETLBFS_I(inode); |
7339ff83 | 369 | mpol_shared_policy_init(&info->policy, MPOL_DEFAULT, NULL); |
1da177e4 LT |
370 | switch (mode & S_IFMT) { |
371 | default: | |
372 | init_special_inode(inode, mode, dev); | |
373 | break; | |
374 | case S_IFREG: | |
375 | inode->i_op = &hugetlbfs_inode_operations; | |
376 | inode->i_fop = &hugetlbfs_file_operations; | |
377 | break; | |
378 | case S_IFDIR: | |
379 | inode->i_op = &hugetlbfs_dir_inode_operations; | |
380 | inode->i_fop = &simple_dir_operations; | |
381 | ||
382 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ | |
383 | inode->i_nlink++; | |
384 | break; | |
385 | case S_IFLNK: | |
386 | inode->i_op = &page_symlink_inode_operations; | |
387 | break; | |
388 | } | |
389 | } | |
390 | return inode; | |
391 | } | |
392 | ||
393 | /* | |
394 | * File creation. Allocate an inode, and we're done.. | |
395 | */ | |
396 | static int hugetlbfs_mknod(struct inode *dir, | |
397 | struct dentry *dentry, int mode, dev_t dev) | |
398 | { | |
399 | struct inode *inode; | |
400 | int error = -ENOSPC; | |
401 | gid_t gid; | |
402 | ||
403 | if (dir->i_mode & S_ISGID) { | |
404 | gid = dir->i_gid; | |
405 | if (S_ISDIR(mode)) | |
406 | mode |= S_ISGID; | |
407 | } else { | |
408 | gid = current->fsgid; | |
409 | } | |
410 | inode = hugetlbfs_get_inode(dir->i_sb, current->fsuid, gid, mode, dev); | |
411 | if (inode) { | |
412 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
413 | d_instantiate(dentry, inode); | |
414 | dget(dentry); /* Extra count - pin the dentry in core */ | |
415 | error = 0; | |
416 | } | |
417 | return error; | |
418 | } | |
419 | ||
420 | static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
421 | { | |
422 | int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0); | |
423 | if (!retval) | |
424 | dir->i_nlink++; | |
425 | return retval; | |
426 | } | |
427 | ||
428 | static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) | |
429 | { | |
430 | return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0); | |
431 | } | |
432 | ||
433 | static int hugetlbfs_symlink(struct inode *dir, | |
434 | struct dentry *dentry, const char *symname) | |
435 | { | |
436 | struct inode *inode; | |
437 | int error = -ENOSPC; | |
438 | gid_t gid; | |
439 | ||
440 | if (dir->i_mode & S_ISGID) | |
441 | gid = dir->i_gid; | |
442 | else | |
443 | gid = current->fsgid; | |
444 | ||
445 | inode = hugetlbfs_get_inode(dir->i_sb, current->fsuid, | |
446 | gid, S_IFLNK|S_IRWXUGO, 0); | |
447 | if (inode) { | |
448 | int l = strlen(symname)+1; | |
449 | error = page_symlink(inode, symname, l); | |
450 | if (!error) { | |
451 | d_instantiate(dentry, inode); | |
452 | dget(dentry); | |
453 | } else | |
454 | iput(inode); | |
455 | } | |
456 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
457 | ||
458 | return error; | |
459 | } | |
460 | ||
461 | /* | |
462 | * For direct-IO reads into hugetlb pages | |
463 | */ | |
464 | static int hugetlbfs_set_page_dirty(struct page *page) | |
465 | { | |
466 | return 0; | |
467 | } | |
468 | ||
726c3342 | 469 | static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
1da177e4 | 470 | { |
726c3342 | 471 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb); |
1da177e4 LT |
472 | |
473 | buf->f_type = HUGETLBFS_MAGIC; | |
474 | buf->f_bsize = HPAGE_SIZE; | |
475 | if (sbinfo) { | |
476 | spin_lock(&sbinfo->stat_lock); | |
74a8a65c DG |
477 | /* If no limits set, just report 0 for max/free/used |
478 | * blocks, like simple_statfs() */ | |
479 | if (sbinfo->max_blocks >= 0) { | |
480 | buf->f_blocks = sbinfo->max_blocks; | |
481 | buf->f_bavail = buf->f_bfree = sbinfo->free_blocks; | |
482 | buf->f_files = sbinfo->max_inodes; | |
483 | buf->f_ffree = sbinfo->free_inodes; | |
484 | } | |
1da177e4 LT |
485 | spin_unlock(&sbinfo->stat_lock); |
486 | } | |
487 | buf->f_namelen = NAME_MAX; | |
488 | return 0; | |
489 | } | |
490 | ||
491 | static void hugetlbfs_put_super(struct super_block *sb) | |
492 | { | |
493 | struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb); | |
494 | ||
495 | if (sbi) { | |
496 | sb->s_fs_info = NULL; | |
497 | kfree(sbi); | |
498 | } | |
499 | } | |
500 | ||
96527980 CH |
501 | static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo) |
502 | { | |
503 | if (sbinfo->free_inodes >= 0) { | |
504 | spin_lock(&sbinfo->stat_lock); | |
505 | if (unlikely(!sbinfo->free_inodes)) { | |
506 | spin_unlock(&sbinfo->stat_lock); | |
507 | return 0; | |
508 | } | |
509 | sbinfo->free_inodes--; | |
510 | spin_unlock(&sbinfo->stat_lock); | |
511 | } | |
512 | ||
513 | return 1; | |
514 | } | |
515 | ||
516 | static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo) | |
517 | { | |
518 | if (sbinfo->free_inodes >= 0) { | |
519 | spin_lock(&sbinfo->stat_lock); | |
520 | sbinfo->free_inodes++; | |
521 | spin_unlock(&sbinfo->stat_lock); | |
522 | } | |
523 | } | |
524 | ||
525 | ||
1da177e4 LT |
526 | static kmem_cache_t *hugetlbfs_inode_cachep; |
527 | ||
528 | static struct inode *hugetlbfs_alloc_inode(struct super_block *sb) | |
529 | { | |
96527980 | 530 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); |
1da177e4 LT |
531 | struct hugetlbfs_inode_info *p; |
532 | ||
96527980 CH |
533 | if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo))) |
534 | return NULL; | |
1da177e4 | 535 | p = kmem_cache_alloc(hugetlbfs_inode_cachep, SLAB_KERNEL); |
96527980 CH |
536 | if (unlikely(!p)) { |
537 | hugetlbfs_inc_free_inodes(sbinfo); | |
1da177e4 | 538 | return NULL; |
96527980 | 539 | } |
1da177e4 LT |
540 | return &p->vfs_inode; |
541 | } | |
542 | ||
1da177e4 LT |
543 | static void hugetlbfs_destroy_inode(struct inode *inode) |
544 | { | |
96527980 | 545 | hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb)); |
1da177e4 LT |
546 | mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy); |
547 | kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode)); | |
548 | } | |
549 | ||
f5e54d6e | 550 | static const struct address_space_operations hugetlbfs_aops = { |
1da177e4 LT |
551 | .readpage = hugetlbfs_readpage, |
552 | .prepare_write = hugetlbfs_prepare_write, | |
553 | .commit_write = hugetlbfs_commit_write, | |
554 | .set_page_dirty = hugetlbfs_set_page_dirty, | |
555 | }; | |
556 | ||
96527980 CH |
557 | |
558 | static void init_once(void *foo, kmem_cache_t *cachep, unsigned long flags) | |
559 | { | |
560 | struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo; | |
561 | ||
562 | if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == | |
563 | SLAB_CTOR_CONSTRUCTOR) | |
564 | inode_init_once(&ei->vfs_inode); | |
565 | } | |
566 | ||
4b6f5d20 | 567 | const struct file_operations hugetlbfs_file_operations = { |
1da177e4 LT |
568 | .mmap = hugetlbfs_file_mmap, |
569 | .fsync = simple_sync_file, | |
570 | .get_unmapped_area = hugetlb_get_unmapped_area, | |
571 | }; | |
572 | ||
573 | static struct inode_operations hugetlbfs_dir_inode_operations = { | |
574 | .create = hugetlbfs_create, | |
575 | .lookup = simple_lookup, | |
576 | .link = simple_link, | |
577 | .unlink = simple_unlink, | |
578 | .symlink = hugetlbfs_symlink, | |
579 | .mkdir = hugetlbfs_mkdir, | |
580 | .rmdir = simple_rmdir, | |
581 | .mknod = hugetlbfs_mknod, | |
582 | .rename = simple_rename, | |
583 | .setattr = hugetlbfs_setattr, | |
584 | }; | |
585 | ||
586 | static struct inode_operations hugetlbfs_inode_operations = { | |
587 | .setattr = hugetlbfs_setattr, | |
588 | }; | |
589 | ||
590 | static struct super_operations hugetlbfs_ops = { | |
591 | .alloc_inode = hugetlbfs_alloc_inode, | |
592 | .destroy_inode = hugetlbfs_destroy_inode, | |
593 | .statfs = hugetlbfs_statfs, | |
149f4211 | 594 | .delete_inode = hugetlbfs_delete_inode, |
1da177e4 LT |
595 | .drop_inode = hugetlbfs_drop_inode, |
596 | .put_super = hugetlbfs_put_super, | |
597 | }; | |
598 | ||
599 | static int | |
600 | hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig) | |
601 | { | |
602 | char *opt, *value, *rest; | |
603 | ||
604 | if (!options) | |
605 | return 0; | |
606 | while ((opt = strsep(&options, ",")) != NULL) { | |
607 | if (!*opt) | |
608 | continue; | |
609 | ||
610 | value = strchr(opt, '='); | |
611 | if (!value || !*value) | |
612 | return -EINVAL; | |
613 | else | |
614 | *value++ = '\0'; | |
615 | ||
616 | if (!strcmp(opt, "uid")) | |
617 | pconfig->uid = simple_strtoul(value, &value, 0); | |
618 | else if (!strcmp(opt, "gid")) | |
619 | pconfig->gid = simple_strtoul(value, &value, 0); | |
620 | else if (!strcmp(opt, "mode")) | |
621 | pconfig->mode = simple_strtoul(value,&value,0) & 0777U; | |
622 | else if (!strcmp(opt, "size")) { | |
623 | unsigned long long size = memparse(value, &rest); | |
624 | if (*rest == '%') { | |
625 | size <<= HPAGE_SHIFT; | |
626 | size *= max_huge_pages; | |
627 | do_div(size, 100); | |
628 | rest++; | |
629 | } | |
630 | size &= HPAGE_MASK; | |
631 | pconfig->nr_blocks = (size >> HPAGE_SHIFT); | |
632 | value = rest; | |
633 | } else if (!strcmp(opt,"nr_inodes")) { | |
634 | pconfig->nr_inodes = memparse(value, &rest); | |
635 | value = rest; | |
636 | } else | |
637 | return -EINVAL; | |
638 | ||
639 | if (*value) | |
640 | return -EINVAL; | |
641 | } | |
642 | return 0; | |
643 | } | |
644 | ||
645 | static int | |
646 | hugetlbfs_fill_super(struct super_block *sb, void *data, int silent) | |
647 | { | |
648 | struct inode * inode; | |
649 | struct dentry * root; | |
650 | int ret; | |
651 | struct hugetlbfs_config config; | |
652 | struct hugetlbfs_sb_info *sbinfo; | |
653 | ||
654 | config.nr_blocks = -1; /* No limit on size by default */ | |
655 | config.nr_inodes = -1; /* No limit on number of inodes by default */ | |
656 | config.uid = current->fsuid; | |
657 | config.gid = current->fsgid; | |
658 | config.mode = 0755; | |
659 | ret = hugetlbfs_parse_options(data, &config); | |
660 | ||
661 | if (ret) | |
662 | return ret; | |
663 | ||
664 | sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL); | |
665 | if (!sbinfo) | |
666 | return -ENOMEM; | |
667 | sb->s_fs_info = sbinfo; | |
668 | spin_lock_init(&sbinfo->stat_lock); | |
669 | sbinfo->max_blocks = config.nr_blocks; | |
670 | sbinfo->free_blocks = config.nr_blocks; | |
671 | sbinfo->max_inodes = config.nr_inodes; | |
672 | sbinfo->free_inodes = config.nr_inodes; | |
673 | sb->s_maxbytes = MAX_LFS_FILESIZE; | |
674 | sb->s_blocksize = HPAGE_SIZE; | |
675 | sb->s_blocksize_bits = HPAGE_SHIFT; | |
676 | sb->s_magic = HUGETLBFS_MAGIC; | |
677 | sb->s_op = &hugetlbfs_ops; | |
678 | sb->s_time_gran = 1; | |
679 | inode = hugetlbfs_get_inode(sb, config.uid, config.gid, | |
680 | S_IFDIR | config.mode, 0); | |
681 | if (!inode) | |
682 | goto out_free; | |
683 | ||
684 | root = d_alloc_root(inode); | |
685 | if (!root) { | |
686 | iput(inode); | |
687 | goto out_free; | |
688 | } | |
689 | sb->s_root = root; | |
690 | return 0; | |
691 | out_free: | |
692 | kfree(sbinfo); | |
693 | return -ENOMEM; | |
694 | } | |
695 | ||
696 | int hugetlb_get_quota(struct address_space *mapping) | |
697 | { | |
698 | int ret = 0; | |
699 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); | |
700 | ||
701 | if (sbinfo->free_blocks > -1) { | |
702 | spin_lock(&sbinfo->stat_lock); | |
703 | if (sbinfo->free_blocks > 0) | |
704 | sbinfo->free_blocks--; | |
705 | else | |
706 | ret = -ENOMEM; | |
707 | spin_unlock(&sbinfo->stat_lock); | |
708 | } | |
709 | ||
710 | return ret; | |
711 | } | |
712 | ||
713 | void hugetlb_put_quota(struct address_space *mapping) | |
714 | { | |
715 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); | |
716 | ||
717 | if (sbinfo->free_blocks > -1) { | |
718 | spin_lock(&sbinfo->stat_lock); | |
719 | sbinfo->free_blocks++; | |
720 | spin_unlock(&sbinfo->stat_lock); | |
721 | } | |
722 | } | |
723 | ||
454e2398 DH |
724 | static int hugetlbfs_get_sb(struct file_system_type *fs_type, |
725 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) | |
1da177e4 | 726 | { |
454e2398 | 727 | return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super, mnt); |
1da177e4 LT |
728 | } |
729 | ||
730 | static struct file_system_type hugetlbfs_fs_type = { | |
731 | .name = "hugetlbfs", | |
732 | .get_sb = hugetlbfs_get_sb, | |
733 | .kill_sb = kill_litter_super, | |
734 | }; | |
735 | ||
736 | static struct vfsmount *hugetlbfs_vfsmount; | |
737 | ||
1da177e4 LT |
738 | static int can_do_hugetlb_shm(void) |
739 | { | |
740 | return likely(capable(CAP_IPC_LOCK) || | |
741 | in_group_p(sysctl_hugetlb_shm_group) || | |
742 | can_do_mlock()); | |
743 | } | |
744 | ||
745 | struct file *hugetlb_zero_setup(size_t size) | |
746 | { | |
747 | int error = -ENOMEM; | |
748 | struct file *file; | |
749 | struct inode *inode; | |
750 | struct dentry *dentry, *root; | |
751 | struct qstr quick_string; | |
752 | char buf[16]; | |
bba1e9b2 | 753 | static atomic_t counter; |
1da177e4 LT |
754 | |
755 | if (!can_do_hugetlb_shm()) | |
756 | return ERR_PTR(-EPERM); | |
757 | ||
1da177e4 LT |
758 | if (!user_shm_lock(size, current->user)) |
759 | return ERR_PTR(-ENOMEM); | |
760 | ||
761 | root = hugetlbfs_vfsmount->mnt_root; | |
bba1e9b2 | 762 | snprintf(buf, 16, "%u", atomic_inc_return(&counter)); |
1da177e4 LT |
763 | quick_string.name = buf; |
764 | quick_string.len = strlen(quick_string.name); | |
765 | quick_string.hash = 0; | |
766 | dentry = d_alloc(root, &quick_string); | |
767 | if (!dentry) | |
768 | goto out_shm_unlock; | |
769 | ||
770 | error = -ENFILE; | |
771 | file = get_empty_filp(); | |
772 | if (!file) | |
773 | goto out_dentry; | |
774 | ||
775 | error = -ENOSPC; | |
776 | inode = hugetlbfs_get_inode(root->d_sb, current->fsuid, | |
777 | current->fsgid, S_IFREG | S_IRWXUGO, 0); | |
778 | if (!inode) | |
779 | goto out_file; | |
780 | ||
b45b5bd6 | 781 | error = -ENOMEM; |
a43a8c39 | 782 | if (hugetlb_reserve_pages(inode, 0, size >> HPAGE_SHIFT)) |
b45b5bd6 DG |
783 | goto out_inode; |
784 | ||
1da177e4 LT |
785 | d_instantiate(dentry, inode); |
786 | inode->i_size = size; | |
787 | inode->i_nlink = 0; | |
788 | file->f_vfsmnt = mntget(hugetlbfs_vfsmount); | |
789 | file->f_dentry = dentry; | |
790 | file->f_mapping = inode->i_mapping; | |
791 | file->f_op = &hugetlbfs_file_operations; | |
792 | file->f_mode = FMODE_WRITE | FMODE_READ; | |
793 | return file; | |
794 | ||
b45b5bd6 DG |
795 | out_inode: |
796 | iput(inode); | |
1da177e4 LT |
797 | out_file: |
798 | put_filp(file); | |
799 | out_dentry: | |
800 | dput(dentry); | |
801 | out_shm_unlock: | |
802 | user_shm_unlock(size, current->user); | |
803 | return ERR_PTR(error); | |
804 | } | |
805 | ||
806 | static int __init init_hugetlbfs_fs(void) | |
807 | { | |
808 | int error; | |
809 | struct vfsmount *vfsmount; | |
810 | ||
811 | hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache", | |
812 | sizeof(struct hugetlbfs_inode_info), | |
813 | 0, 0, init_once, NULL); | |
814 | if (hugetlbfs_inode_cachep == NULL) | |
815 | return -ENOMEM; | |
816 | ||
817 | error = register_filesystem(&hugetlbfs_fs_type); | |
818 | if (error) | |
819 | goto out; | |
820 | ||
821 | vfsmount = kern_mount(&hugetlbfs_fs_type); | |
822 | ||
823 | if (!IS_ERR(vfsmount)) { | |
824 | hugetlbfs_vfsmount = vfsmount; | |
825 | return 0; | |
826 | } | |
827 | ||
828 | error = PTR_ERR(vfsmount); | |
829 | ||
830 | out: | |
831 | if (error) | |
832 | kmem_cache_destroy(hugetlbfs_inode_cachep); | |
833 | return error; | |
834 | } | |
835 | ||
836 | static void __exit exit_hugetlbfs_fs(void) | |
837 | { | |
838 | kmem_cache_destroy(hugetlbfs_inode_cachep); | |
839 | unregister_filesystem(&hugetlbfs_fs_type); | |
840 | } | |
841 | ||
842 | module_init(init_hugetlbfs_fs) | |
843 | module_exit(exit_hugetlbfs_fs) | |
844 | ||
845 | MODULE_LICENSE("GPL"); |