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> | |
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 | { | |
b39424e2 | 61 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
62 | loff_t len, vma_len; |
63 | int ret; | |
64 | ||
68589bc3 HD |
65 | /* |
66 | * vma alignment has already been checked by prepare_hugepage_range. | |
67 | * If you add any error returns here, do so after setting VM_HUGETLB, | |
68 | * so is_vm_hugetlb_page tests below unmap_region go the right way | |
69 | * when do_mmap_pgoff unwinds (may be important on powerpc and ia64). | |
70 | */ | |
71 | vma->vm_flags |= VM_HUGETLB | VM_RESERVED; | |
72 | vma->vm_ops = &hugetlb_vm_ops; | |
1da177e4 LT |
73 | |
74 | vma_len = (loff_t)(vma->vm_end - vma->vm_start); | |
75 | ||
1b1dcc1b | 76 | mutex_lock(&inode->i_mutex); |
1da177e4 | 77 | file_accessed(file); |
1da177e4 LT |
78 | |
79 | ret = -ENOMEM; | |
80 | len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
1da177e4 | 81 | |
a43a8c39 CK |
82 | if (vma->vm_flags & VM_MAYSHARE && |
83 | hugetlb_reserve_pages(inode, vma->vm_pgoff >> (HPAGE_SHIFT-PAGE_SHIFT), | |
84 | len >> HPAGE_SHIFT)) | |
85 | goto out; | |
b45b5bd6 | 86 | |
4c887265 AL |
87 | ret = 0; |
88 | hugetlb_prefault_arch_hook(vma->vm_mm); | |
b6174df5 | 89 | if (vma->vm_flags & VM_WRITE && inode->i_size < len) |
1da177e4 LT |
90 | inode->i_size = len; |
91 | out: | |
1b1dcc1b | 92 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
93 | |
94 | return ret; | |
95 | } | |
96 | ||
97 | /* | |
508034a3 | 98 | * Called under down_write(mmap_sem). |
1da177e4 LT |
99 | */ |
100 | ||
101 | #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA | |
102 | unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, | |
103 | unsigned long len, unsigned long pgoff, unsigned long flags); | |
104 | #else | |
105 | static unsigned long | |
106 | hugetlb_get_unmapped_area(struct file *file, unsigned long addr, | |
107 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
108 | { | |
109 | struct mm_struct *mm = current->mm; | |
110 | struct vm_area_struct *vma; | |
111 | unsigned long start_addr; | |
112 | ||
113 | if (len & ~HPAGE_MASK) | |
114 | return -EINVAL; | |
115 | if (len > TASK_SIZE) | |
116 | return -ENOMEM; | |
117 | ||
118 | if (addr) { | |
119 | addr = ALIGN(addr, HPAGE_SIZE); | |
120 | vma = find_vma(mm, addr); | |
121 | if (TASK_SIZE - len >= addr && | |
122 | (!vma || addr + len <= vma->vm_start)) | |
123 | return addr; | |
124 | } | |
125 | ||
126 | start_addr = mm->free_area_cache; | |
127 | ||
1363c3cd WW |
128 | if (len <= mm->cached_hole_size) |
129 | start_addr = TASK_UNMAPPED_BASE; | |
130 | ||
1da177e4 LT |
131 | full_search: |
132 | addr = ALIGN(start_addr, HPAGE_SIZE); | |
133 | ||
134 | for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { | |
135 | /* At this point: (!vma || addr < vma->vm_end). */ | |
136 | if (TASK_SIZE - len < addr) { | |
137 | /* | |
138 | * Start a new search - just in case we missed | |
139 | * some holes. | |
140 | */ | |
141 | if (start_addr != TASK_UNMAPPED_BASE) { | |
142 | start_addr = TASK_UNMAPPED_BASE; | |
143 | goto full_search; | |
144 | } | |
145 | return -ENOMEM; | |
146 | } | |
147 | ||
148 | if (!vma || addr + len <= vma->vm_start) | |
149 | return addr; | |
150 | addr = ALIGN(vma->vm_end, HPAGE_SIZE); | |
151 | } | |
152 | } | |
153 | #endif | |
154 | ||
155 | /* | |
156 | * Read a page. Again trivial. If it didn't already exist | |
157 | * in the page cache, it is zero-filled. | |
158 | */ | |
159 | static int hugetlbfs_readpage(struct file *file, struct page * page) | |
160 | { | |
161 | unlock_page(page); | |
162 | return -EINVAL; | |
163 | } | |
164 | ||
165 | static int hugetlbfs_prepare_write(struct file *file, | |
166 | struct page *page, unsigned offset, unsigned to) | |
167 | { | |
168 | return -EINVAL; | |
169 | } | |
170 | ||
171 | static int hugetlbfs_commit_write(struct file *file, | |
172 | struct page *page, unsigned offset, unsigned to) | |
173 | { | |
174 | return -EINVAL; | |
175 | } | |
176 | ||
1da177e4 LT |
177 | static void truncate_huge_page(struct page *page) |
178 | { | |
179 | clear_page_dirty(page); | |
180 | ClearPageUptodate(page); | |
181 | remove_from_page_cache(page); | |
182 | put_page(page); | |
183 | } | |
184 | ||
b45b5bd6 | 185 | static void truncate_hugepages(struct inode *inode, loff_t lstart) |
1da177e4 | 186 | { |
b45b5bd6 | 187 | struct address_space *mapping = &inode->i_data; |
1da177e4 LT |
188 | const pgoff_t start = lstart >> HPAGE_SHIFT; |
189 | struct pagevec pvec; | |
190 | pgoff_t next; | |
a43a8c39 | 191 | int i, freed = 0; |
1da177e4 LT |
192 | |
193 | pagevec_init(&pvec, 0); | |
194 | next = start; | |
195 | while (1) { | |
196 | if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) { | |
197 | if (next == start) | |
198 | break; | |
199 | next = start; | |
200 | continue; | |
201 | } | |
202 | ||
203 | for (i = 0; i < pagevec_count(&pvec); ++i) { | |
204 | struct page *page = pvec.pages[i]; | |
205 | ||
206 | lock_page(page); | |
207 | if (page->index > next) | |
208 | next = page->index; | |
209 | ++next; | |
210 | truncate_huge_page(page); | |
211 | unlock_page(page); | |
212 | hugetlb_put_quota(mapping); | |
a43a8c39 | 213 | freed++; |
1da177e4 LT |
214 | } |
215 | huge_pagevec_release(&pvec); | |
216 | } | |
217 | BUG_ON(!lstart && mapping->nrpages); | |
a43a8c39 | 218 | hugetlb_unreserve_pages(inode, start, freed); |
1da177e4 LT |
219 | } |
220 | ||
221 | static void hugetlbfs_delete_inode(struct inode *inode) | |
222 | { | |
b45b5bd6 | 223 | truncate_hugepages(inode, 0); |
149f4211 CH |
224 | clear_inode(inode); |
225 | } | |
226 | ||
ddc0a51d | 227 | static void hugetlbfs_forget_inode(struct inode *inode) __releases(inode_lock) |
1da177e4 | 228 | { |
0b1533f6 CH |
229 | struct super_block *sb = inode->i_sb; |
230 | ||
231 | if (!hlist_unhashed(&inode->i_hash)) { | |
232 | if (!(inode->i_state & (I_DIRTY|I_LOCK))) | |
233 | list_move(&inode->i_list, &inode_unused); | |
234 | inodes_stat.nr_unused++; | |
235 | if (!sb || (sb->s_flags & MS_ACTIVE)) { | |
236 | spin_unlock(&inode_lock); | |
237 | return; | |
238 | } | |
239 | inode->i_state |= I_WILL_FREE; | |
1da177e4 | 240 | spin_unlock(&inode_lock); |
0b1533f6 CH |
241 | /* |
242 | * write_inode_now is a noop as we set BDI_CAP_NO_WRITEBACK | |
243 | * in our backing_dev_info. | |
244 | */ | |
245 | write_inode_now(inode, 1); | |
246 | spin_lock(&inode_lock); | |
247 | inode->i_state &= ~I_WILL_FREE; | |
248 | inodes_stat.nr_unused--; | |
249 | hlist_del_init(&inode->i_hash); | |
1da177e4 | 250 | } |
1da177e4 LT |
251 | list_del_init(&inode->i_list); |
252 | list_del_init(&inode->i_sb_list); | |
253 | inode->i_state |= I_FREEING; | |
254 | inodes_stat.nr_inodes--; | |
255 | spin_unlock(&inode_lock); | |
b45b5bd6 | 256 | truncate_hugepages(inode, 0); |
1da177e4 LT |
257 | clear_inode(inode); |
258 | destroy_inode(inode); | |
259 | } | |
260 | ||
261 | static void hugetlbfs_drop_inode(struct inode *inode) | |
262 | { | |
263 | if (!inode->i_nlink) | |
6b09b9df | 264 | generic_delete_inode(inode); |
1da177e4 LT |
265 | else |
266 | hugetlbfs_forget_inode(inode); | |
267 | } | |
268 | ||
1da177e4 | 269 | static inline void |
856fc295 | 270 | hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff) |
1da177e4 LT |
271 | { |
272 | struct vm_area_struct *vma; | |
273 | struct prio_tree_iter iter; | |
274 | ||
856fc295 | 275 | vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) { |
1da177e4 LT |
276 | unsigned long v_offset; |
277 | ||
1da177e4 | 278 | /* |
856fc295 HD |
279 | * Can the expression below overflow on 32-bit arches? |
280 | * No, because the prio_tree returns us only those vmas | |
281 | * which overlap the truncated area starting at pgoff, | |
282 | * and no vma on a 32-bit arch can span beyond the 4GB. | |
1da177e4 | 283 | */ |
856fc295 HD |
284 | if (vma->vm_pgoff < pgoff) |
285 | v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT; | |
286 | else | |
1da177e4 LT |
287 | v_offset = 0; |
288 | ||
502717f4 | 289 | __unmap_hugepage_range(vma, |
508034a3 | 290 | vma->vm_start + v_offset, vma->vm_end); |
1da177e4 LT |
291 | } |
292 | } | |
293 | ||
294 | /* | |
295 | * Expanding truncates are not allowed. | |
296 | */ | |
297 | static int hugetlb_vmtruncate(struct inode *inode, loff_t offset) | |
298 | { | |
856fc295 | 299 | pgoff_t pgoff; |
1da177e4 LT |
300 | struct address_space *mapping = inode->i_mapping; |
301 | ||
302 | if (offset > inode->i_size) | |
303 | return -EINVAL; | |
304 | ||
305 | BUG_ON(offset & ~HPAGE_MASK); | |
856fc295 | 306 | pgoff = offset >> PAGE_SHIFT; |
1da177e4 LT |
307 | |
308 | inode->i_size = offset; | |
309 | spin_lock(&mapping->i_mmap_lock); | |
310 | if (!prio_tree_empty(&mapping->i_mmap)) | |
311 | hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff); | |
312 | spin_unlock(&mapping->i_mmap_lock); | |
b45b5bd6 | 313 | truncate_hugepages(inode, offset); |
1da177e4 LT |
314 | return 0; |
315 | } | |
316 | ||
317 | static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr) | |
318 | { | |
319 | struct inode *inode = dentry->d_inode; | |
320 | int error; | |
321 | unsigned int ia_valid = attr->ia_valid; | |
322 | ||
323 | BUG_ON(!inode); | |
324 | ||
325 | error = inode_change_ok(inode, attr); | |
326 | if (error) | |
327 | goto out; | |
328 | ||
329 | if (ia_valid & ATTR_SIZE) { | |
330 | error = -EINVAL; | |
331 | if (!(attr->ia_size & ~HPAGE_MASK)) | |
332 | error = hugetlb_vmtruncate(inode, attr->ia_size); | |
333 | if (error) | |
334 | goto out; | |
335 | attr->ia_valid &= ~ATTR_SIZE; | |
336 | } | |
337 | error = inode_setattr(inode, attr); | |
338 | out: | |
339 | return error; | |
340 | } | |
341 | ||
342 | static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid, | |
343 | gid_t gid, int mode, dev_t dev) | |
344 | { | |
345 | struct inode *inode; | |
1da177e4 LT |
346 | |
347 | inode = new_inode(sb); | |
348 | if (inode) { | |
349 | struct hugetlbfs_inode_info *info; | |
350 | inode->i_mode = mode; | |
351 | inode->i_uid = uid; | |
352 | inode->i_gid = gid; | |
1da177e4 LT |
353 | inode->i_blocks = 0; |
354 | inode->i_mapping->a_ops = &hugetlbfs_aops; | |
355 | inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info; | |
356 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
a43a8c39 | 357 | INIT_LIST_HEAD(&inode->i_mapping->private_list); |
1da177e4 | 358 | info = HUGETLBFS_I(inode); |
7339ff83 | 359 | mpol_shared_policy_init(&info->policy, MPOL_DEFAULT, NULL); |
1da177e4 LT |
360 | switch (mode & S_IFMT) { |
361 | default: | |
362 | init_special_inode(inode, mode, dev); | |
363 | break; | |
364 | case S_IFREG: | |
365 | inode->i_op = &hugetlbfs_inode_operations; | |
366 | inode->i_fop = &hugetlbfs_file_operations; | |
367 | break; | |
368 | case S_IFDIR: | |
369 | inode->i_op = &hugetlbfs_dir_inode_operations; | |
370 | inode->i_fop = &simple_dir_operations; | |
371 | ||
372 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ | |
d8c76e6f | 373 | inc_nlink(inode); |
1da177e4 LT |
374 | break; |
375 | case S_IFLNK: | |
376 | inode->i_op = &page_symlink_inode_operations; | |
377 | break; | |
378 | } | |
379 | } | |
380 | return inode; | |
381 | } | |
382 | ||
383 | /* | |
384 | * File creation. Allocate an inode, and we're done.. | |
385 | */ | |
386 | static int hugetlbfs_mknod(struct inode *dir, | |
387 | struct dentry *dentry, int mode, dev_t dev) | |
388 | { | |
389 | struct inode *inode; | |
390 | int error = -ENOSPC; | |
391 | gid_t gid; | |
392 | ||
393 | if (dir->i_mode & S_ISGID) { | |
394 | gid = dir->i_gid; | |
395 | if (S_ISDIR(mode)) | |
396 | mode |= S_ISGID; | |
397 | } else { | |
398 | gid = current->fsgid; | |
399 | } | |
400 | inode = hugetlbfs_get_inode(dir->i_sb, current->fsuid, gid, mode, dev); | |
401 | if (inode) { | |
402 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
403 | d_instantiate(dentry, inode); | |
404 | dget(dentry); /* Extra count - pin the dentry in core */ | |
405 | error = 0; | |
406 | } | |
407 | return error; | |
408 | } | |
409 | ||
410 | static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
411 | { | |
412 | int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0); | |
413 | if (!retval) | |
d8c76e6f | 414 | inc_nlink(dir); |
1da177e4 LT |
415 | return retval; |
416 | } | |
417 | ||
418 | static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) | |
419 | { | |
420 | return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0); | |
421 | } | |
422 | ||
423 | static int hugetlbfs_symlink(struct inode *dir, | |
424 | struct dentry *dentry, const char *symname) | |
425 | { | |
426 | struct inode *inode; | |
427 | int error = -ENOSPC; | |
428 | gid_t gid; | |
429 | ||
430 | if (dir->i_mode & S_ISGID) | |
431 | gid = dir->i_gid; | |
432 | else | |
433 | gid = current->fsgid; | |
434 | ||
435 | inode = hugetlbfs_get_inode(dir->i_sb, current->fsuid, | |
436 | gid, S_IFLNK|S_IRWXUGO, 0); | |
437 | if (inode) { | |
438 | int l = strlen(symname)+1; | |
439 | error = page_symlink(inode, symname, l); | |
440 | if (!error) { | |
441 | d_instantiate(dentry, inode); | |
442 | dget(dentry); | |
443 | } else | |
444 | iput(inode); | |
445 | } | |
446 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
447 | ||
448 | return error; | |
449 | } | |
450 | ||
451 | /* | |
452 | * For direct-IO reads into hugetlb pages | |
453 | */ | |
454 | static int hugetlbfs_set_page_dirty(struct page *page) | |
455 | { | |
456 | return 0; | |
457 | } | |
458 | ||
726c3342 | 459 | static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
1da177e4 | 460 | { |
726c3342 | 461 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb); |
1da177e4 LT |
462 | |
463 | buf->f_type = HUGETLBFS_MAGIC; | |
464 | buf->f_bsize = HPAGE_SIZE; | |
465 | if (sbinfo) { | |
466 | spin_lock(&sbinfo->stat_lock); | |
74a8a65c DG |
467 | /* If no limits set, just report 0 for max/free/used |
468 | * blocks, like simple_statfs() */ | |
469 | if (sbinfo->max_blocks >= 0) { | |
470 | buf->f_blocks = sbinfo->max_blocks; | |
471 | buf->f_bavail = buf->f_bfree = sbinfo->free_blocks; | |
472 | buf->f_files = sbinfo->max_inodes; | |
473 | buf->f_ffree = sbinfo->free_inodes; | |
474 | } | |
1da177e4 LT |
475 | spin_unlock(&sbinfo->stat_lock); |
476 | } | |
477 | buf->f_namelen = NAME_MAX; | |
478 | return 0; | |
479 | } | |
480 | ||
481 | static void hugetlbfs_put_super(struct super_block *sb) | |
482 | { | |
483 | struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb); | |
484 | ||
485 | if (sbi) { | |
486 | sb->s_fs_info = NULL; | |
487 | kfree(sbi); | |
488 | } | |
489 | } | |
490 | ||
96527980 CH |
491 | static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo) |
492 | { | |
493 | if (sbinfo->free_inodes >= 0) { | |
494 | spin_lock(&sbinfo->stat_lock); | |
495 | if (unlikely(!sbinfo->free_inodes)) { | |
496 | spin_unlock(&sbinfo->stat_lock); | |
497 | return 0; | |
498 | } | |
499 | sbinfo->free_inodes--; | |
500 | spin_unlock(&sbinfo->stat_lock); | |
501 | } | |
502 | ||
503 | return 1; | |
504 | } | |
505 | ||
506 | static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo) | |
507 | { | |
508 | if (sbinfo->free_inodes >= 0) { | |
509 | spin_lock(&sbinfo->stat_lock); | |
510 | sbinfo->free_inodes++; | |
511 | spin_unlock(&sbinfo->stat_lock); | |
512 | } | |
513 | } | |
514 | ||
515 | ||
e18b890b | 516 | static struct kmem_cache *hugetlbfs_inode_cachep; |
1da177e4 LT |
517 | |
518 | static struct inode *hugetlbfs_alloc_inode(struct super_block *sb) | |
519 | { | |
96527980 | 520 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); |
1da177e4 LT |
521 | struct hugetlbfs_inode_info *p; |
522 | ||
96527980 CH |
523 | if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo))) |
524 | return NULL; | |
e94b1766 | 525 | p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL); |
96527980 CH |
526 | if (unlikely(!p)) { |
527 | hugetlbfs_inc_free_inodes(sbinfo); | |
1da177e4 | 528 | return NULL; |
96527980 | 529 | } |
1da177e4 LT |
530 | return &p->vfs_inode; |
531 | } | |
532 | ||
1da177e4 LT |
533 | static void hugetlbfs_destroy_inode(struct inode *inode) |
534 | { | |
96527980 | 535 | hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb)); |
1da177e4 LT |
536 | mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy); |
537 | kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode)); | |
538 | } | |
539 | ||
f5e54d6e | 540 | static const struct address_space_operations hugetlbfs_aops = { |
1da177e4 LT |
541 | .readpage = hugetlbfs_readpage, |
542 | .prepare_write = hugetlbfs_prepare_write, | |
543 | .commit_write = hugetlbfs_commit_write, | |
544 | .set_page_dirty = hugetlbfs_set_page_dirty, | |
545 | }; | |
546 | ||
96527980 | 547 | |
e18b890b | 548 | static void init_once(void *foo, struct kmem_cache *cachep, unsigned long flags) |
96527980 CH |
549 | { |
550 | struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo; | |
551 | ||
552 | if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == | |
553 | SLAB_CTOR_CONSTRUCTOR) | |
554 | inode_init_once(&ei->vfs_inode); | |
555 | } | |
556 | ||
4b6f5d20 | 557 | const struct file_operations hugetlbfs_file_operations = { |
1da177e4 LT |
558 | .mmap = hugetlbfs_file_mmap, |
559 | .fsync = simple_sync_file, | |
560 | .get_unmapped_area = hugetlb_get_unmapped_area, | |
561 | }; | |
562 | ||
563 | static struct inode_operations hugetlbfs_dir_inode_operations = { | |
564 | .create = hugetlbfs_create, | |
565 | .lookup = simple_lookup, | |
566 | .link = simple_link, | |
567 | .unlink = simple_unlink, | |
568 | .symlink = hugetlbfs_symlink, | |
569 | .mkdir = hugetlbfs_mkdir, | |
570 | .rmdir = simple_rmdir, | |
571 | .mknod = hugetlbfs_mknod, | |
572 | .rename = simple_rename, | |
573 | .setattr = hugetlbfs_setattr, | |
574 | }; | |
575 | ||
576 | static struct inode_operations hugetlbfs_inode_operations = { | |
577 | .setattr = hugetlbfs_setattr, | |
578 | }; | |
579 | ||
580 | static struct super_operations hugetlbfs_ops = { | |
581 | .alloc_inode = hugetlbfs_alloc_inode, | |
582 | .destroy_inode = hugetlbfs_destroy_inode, | |
583 | .statfs = hugetlbfs_statfs, | |
149f4211 | 584 | .delete_inode = hugetlbfs_delete_inode, |
1da177e4 LT |
585 | .drop_inode = hugetlbfs_drop_inode, |
586 | .put_super = hugetlbfs_put_super, | |
587 | }; | |
588 | ||
589 | static int | |
590 | hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig) | |
591 | { | |
592 | char *opt, *value, *rest; | |
593 | ||
594 | if (!options) | |
595 | return 0; | |
596 | while ((opt = strsep(&options, ",")) != NULL) { | |
597 | if (!*opt) | |
598 | continue; | |
599 | ||
600 | value = strchr(opt, '='); | |
601 | if (!value || !*value) | |
602 | return -EINVAL; | |
603 | else | |
604 | *value++ = '\0'; | |
605 | ||
606 | if (!strcmp(opt, "uid")) | |
607 | pconfig->uid = simple_strtoul(value, &value, 0); | |
608 | else if (!strcmp(opt, "gid")) | |
609 | pconfig->gid = simple_strtoul(value, &value, 0); | |
610 | else if (!strcmp(opt, "mode")) | |
611 | pconfig->mode = simple_strtoul(value,&value,0) & 0777U; | |
612 | else if (!strcmp(opt, "size")) { | |
613 | unsigned long long size = memparse(value, &rest); | |
614 | if (*rest == '%') { | |
615 | size <<= HPAGE_SHIFT; | |
616 | size *= max_huge_pages; | |
617 | do_div(size, 100); | |
618 | rest++; | |
619 | } | |
1da177e4 LT |
620 | pconfig->nr_blocks = (size >> HPAGE_SHIFT); |
621 | value = rest; | |
622 | } else if (!strcmp(opt,"nr_inodes")) { | |
623 | pconfig->nr_inodes = memparse(value, &rest); | |
624 | value = rest; | |
625 | } else | |
626 | return -EINVAL; | |
627 | ||
628 | if (*value) | |
629 | return -EINVAL; | |
630 | } | |
631 | return 0; | |
632 | } | |
633 | ||
634 | static int | |
635 | hugetlbfs_fill_super(struct super_block *sb, void *data, int silent) | |
636 | { | |
637 | struct inode * inode; | |
638 | struct dentry * root; | |
639 | int ret; | |
640 | struct hugetlbfs_config config; | |
641 | struct hugetlbfs_sb_info *sbinfo; | |
642 | ||
643 | config.nr_blocks = -1; /* No limit on size by default */ | |
644 | config.nr_inodes = -1; /* No limit on number of inodes by default */ | |
645 | config.uid = current->fsuid; | |
646 | config.gid = current->fsgid; | |
647 | config.mode = 0755; | |
648 | ret = hugetlbfs_parse_options(data, &config); | |
649 | ||
650 | if (ret) | |
651 | return ret; | |
652 | ||
653 | sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL); | |
654 | if (!sbinfo) | |
655 | return -ENOMEM; | |
656 | sb->s_fs_info = sbinfo; | |
657 | spin_lock_init(&sbinfo->stat_lock); | |
658 | sbinfo->max_blocks = config.nr_blocks; | |
659 | sbinfo->free_blocks = config.nr_blocks; | |
660 | sbinfo->max_inodes = config.nr_inodes; | |
661 | sbinfo->free_inodes = config.nr_inodes; | |
662 | sb->s_maxbytes = MAX_LFS_FILESIZE; | |
663 | sb->s_blocksize = HPAGE_SIZE; | |
664 | sb->s_blocksize_bits = HPAGE_SHIFT; | |
665 | sb->s_magic = HUGETLBFS_MAGIC; | |
666 | sb->s_op = &hugetlbfs_ops; | |
667 | sb->s_time_gran = 1; | |
668 | inode = hugetlbfs_get_inode(sb, config.uid, config.gid, | |
669 | S_IFDIR | config.mode, 0); | |
670 | if (!inode) | |
671 | goto out_free; | |
672 | ||
673 | root = d_alloc_root(inode); | |
674 | if (!root) { | |
675 | iput(inode); | |
676 | goto out_free; | |
677 | } | |
678 | sb->s_root = root; | |
679 | return 0; | |
680 | out_free: | |
681 | kfree(sbinfo); | |
682 | return -ENOMEM; | |
683 | } | |
684 | ||
685 | int hugetlb_get_quota(struct address_space *mapping) | |
686 | { | |
687 | int ret = 0; | |
688 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); | |
689 | ||
690 | if (sbinfo->free_blocks > -1) { | |
691 | spin_lock(&sbinfo->stat_lock); | |
692 | if (sbinfo->free_blocks > 0) | |
693 | sbinfo->free_blocks--; | |
694 | else | |
695 | ret = -ENOMEM; | |
696 | spin_unlock(&sbinfo->stat_lock); | |
697 | } | |
698 | ||
699 | return ret; | |
700 | } | |
701 | ||
702 | void hugetlb_put_quota(struct address_space *mapping) | |
703 | { | |
704 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); | |
705 | ||
706 | if (sbinfo->free_blocks > -1) { | |
707 | spin_lock(&sbinfo->stat_lock); | |
708 | sbinfo->free_blocks++; | |
709 | spin_unlock(&sbinfo->stat_lock); | |
710 | } | |
711 | } | |
712 | ||
454e2398 DH |
713 | static int hugetlbfs_get_sb(struct file_system_type *fs_type, |
714 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) | |
1da177e4 | 715 | { |
454e2398 | 716 | return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super, mnt); |
1da177e4 LT |
717 | } |
718 | ||
719 | static struct file_system_type hugetlbfs_fs_type = { | |
720 | .name = "hugetlbfs", | |
721 | .get_sb = hugetlbfs_get_sb, | |
722 | .kill_sb = kill_litter_super, | |
723 | }; | |
724 | ||
725 | static struct vfsmount *hugetlbfs_vfsmount; | |
726 | ||
1da177e4 LT |
727 | static int can_do_hugetlb_shm(void) |
728 | { | |
729 | return likely(capable(CAP_IPC_LOCK) || | |
730 | in_group_p(sysctl_hugetlb_shm_group) || | |
731 | can_do_mlock()); | |
732 | } | |
733 | ||
734 | struct file *hugetlb_zero_setup(size_t size) | |
735 | { | |
736 | int error = -ENOMEM; | |
737 | struct file *file; | |
738 | struct inode *inode; | |
739 | struct dentry *dentry, *root; | |
740 | struct qstr quick_string; | |
741 | char buf[16]; | |
bba1e9b2 | 742 | static atomic_t counter; |
1da177e4 LT |
743 | |
744 | if (!can_do_hugetlb_shm()) | |
745 | return ERR_PTR(-EPERM); | |
746 | ||
1da177e4 LT |
747 | if (!user_shm_lock(size, current->user)) |
748 | return ERR_PTR(-ENOMEM); | |
749 | ||
750 | root = hugetlbfs_vfsmount->mnt_root; | |
bba1e9b2 | 751 | snprintf(buf, 16, "%u", atomic_inc_return(&counter)); |
1da177e4 LT |
752 | quick_string.name = buf; |
753 | quick_string.len = strlen(quick_string.name); | |
754 | quick_string.hash = 0; | |
755 | dentry = d_alloc(root, &quick_string); | |
756 | if (!dentry) | |
757 | goto out_shm_unlock; | |
758 | ||
759 | error = -ENFILE; | |
760 | file = get_empty_filp(); | |
761 | if (!file) | |
762 | goto out_dentry; | |
763 | ||
764 | error = -ENOSPC; | |
765 | inode = hugetlbfs_get_inode(root->d_sb, current->fsuid, | |
766 | current->fsgid, S_IFREG | S_IRWXUGO, 0); | |
767 | if (!inode) | |
768 | goto out_file; | |
769 | ||
b45b5bd6 | 770 | error = -ENOMEM; |
a43a8c39 | 771 | if (hugetlb_reserve_pages(inode, 0, size >> HPAGE_SHIFT)) |
b45b5bd6 DG |
772 | goto out_inode; |
773 | ||
1da177e4 LT |
774 | d_instantiate(dentry, inode); |
775 | inode->i_size = size; | |
776 | inode->i_nlink = 0; | |
b39424e2 JS |
777 | file->f_path.mnt = mntget(hugetlbfs_vfsmount); |
778 | file->f_path.dentry = dentry; | |
1da177e4 LT |
779 | file->f_mapping = inode->i_mapping; |
780 | file->f_op = &hugetlbfs_file_operations; | |
781 | file->f_mode = FMODE_WRITE | FMODE_READ; | |
782 | return file; | |
783 | ||
b45b5bd6 DG |
784 | out_inode: |
785 | iput(inode); | |
1da177e4 LT |
786 | out_file: |
787 | put_filp(file); | |
788 | out_dentry: | |
789 | dput(dentry); | |
790 | out_shm_unlock: | |
791 | user_shm_unlock(size, current->user); | |
792 | return ERR_PTR(error); | |
793 | } | |
794 | ||
795 | static int __init init_hugetlbfs_fs(void) | |
796 | { | |
797 | int error; | |
798 | struct vfsmount *vfsmount; | |
799 | ||
800 | hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache", | |
801 | sizeof(struct hugetlbfs_inode_info), | |
802 | 0, 0, init_once, NULL); | |
803 | if (hugetlbfs_inode_cachep == NULL) | |
804 | return -ENOMEM; | |
805 | ||
806 | error = register_filesystem(&hugetlbfs_fs_type); | |
807 | if (error) | |
808 | goto out; | |
809 | ||
810 | vfsmount = kern_mount(&hugetlbfs_fs_type); | |
811 | ||
812 | if (!IS_ERR(vfsmount)) { | |
813 | hugetlbfs_vfsmount = vfsmount; | |
814 | return 0; | |
815 | } | |
816 | ||
817 | error = PTR_ERR(vfsmount); | |
818 | ||
819 | out: | |
820 | if (error) | |
821 | kmem_cache_destroy(hugetlbfs_inode_cachep); | |
822 | return error; | |
823 | } | |
824 | ||
825 | static void __exit exit_hugetlbfs_fs(void) | |
826 | { | |
827 | kmem_cache_destroy(hugetlbfs_inode_cachep); | |
828 | unregister_filesystem(&hugetlbfs_fs_type); | |
829 | } | |
830 | ||
831 | module_init(init_hugetlbfs_fs) | |
832 | module_exit(exit_hugetlbfs_fs) | |
833 | ||
834 | MODULE_LICENSE("GPL"); |