1
2
3
4
5
6
7
8
9#include "fuse_i.h"
10
11#include <linux/pagemap.h>
12#include <linux/slab.h>
13#include <linux/file.h>
14#include <linux/seq_file.h>
15#include <linux/init.h>
16#include <linux/module.h>
17#include <linux/moduleparam.h>
18#include <linux/parser.h>
19#include <linux/statfs.h>
20#include <linux/random.h>
21#include <linux/sched.h>
22#include <linux/exportfs.h>
23
24MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
25MODULE_DESCRIPTION("Filesystem in Userspace");
26MODULE_LICENSE("GPL");
27
28static struct kmem_cache *fuse_inode_cachep;
29struct list_head fuse_conn_list;
30DEFINE_MUTEX(fuse_mutex);
31
32static int set_global_limit(const char *val, struct kernel_param *kp);
33
34unsigned max_user_bgreq;
35module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
36 &max_user_bgreq, 0644);
37__MODULE_PARM_TYPE(max_user_bgreq, "uint");
38MODULE_PARM_DESC(max_user_bgreq,
39 "Global limit for the maximum number of backgrounded requests an "
40 "unprivileged user can set");
41
42unsigned max_user_congthresh;
43module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
44 &max_user_congthresh, 0644);
45__MODULE_PARM_TYPE(max_user_congthresh, "uint");
46MODULE_PARM_DESC(max_user_congthresh,
47 "Global limit for the maximum congestion threshold an "
48 "unprivileged user can set");
49
50#define FUSE_SUPER_MAGIC 0x65735546
51
52#define FUSE_DEFAULT_BLKSIZE 512
53
54
55#define FUSE_DEFAULT_MAX_BACKGROUND 12
56
57
58#define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
59
60struct fuse_mount_data {
61 int fd;
62 unsigned rootmode;
63 kuid_t user_id;
64 kgid_t group_id;
65 unsigned fd_present:1;
66 unsigned rootmode_present:1;
67 unsigned user_id_present:1;
68 unsigned group_id_present:1;
69 unsigned flags;
70 unsigned max_read;
71 unsigned blksize;
72};
73
74struct fuse_forget_link *fuse_alloc_forget(void)
75{
76 return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL);
77}
78
79static struct inode *fuse_alloc_inode(struct super_block *sb)
80{
81 struct inode *inode;
82 struct fuse_inode *fi;
83
84 inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
85 if (!inode)
86 return NULL;
87
88 fi = get_fuse_inode(inode);
89 fi->i_time = 0;
90 fi->nodeid = 0;
91 fi->nlookup = 0;
92 fi->attr_version = 0;
93 fi->writectr = 0;
94 fi->orig_ino = 0;
95 fi->state = 0;
96 INIT_LIST_HEAD(&fi->write_files);
97 INIT_LIST_HEAD(&fi->queued_writes);
98 INIT_LIST_HEAD(&fi->writepages);
99 init_waitqueue_head(&fi->page_waitq);
100 mutex_init(&fi->mutex);
101 fi->forget = fuse_alloc_forget();
102 if (!fi->forget) {
103 kmem_cache_free(fuse_inode_cachep, inode);
104 return NULL;
105 }
106
107 return inode;
108}
109
110static void fuse_i_callback(struct rcu_head *head)
111{
112 struct inode *inode = container_of(head, struct inode, i_rcu);
113 kmem_cache_free(fuse_inode_cachep, inode);
114}
115
116static void fuse_destroy_inode(struct inode *inode)
117{
118 struct fuse_inode *fi = get_fuse_inode(inode);
119 BUG_ON(!list_empty(&fi->write_files));
120 BUG_ON(!list_empty(&fi->queued_writes));
121 mutex_destroy(&fi->mutex);
122 kfree(fi->forget);
123 call_rcu(&inode->i_rcu, fuse_i_callback);
124}
125
126static void fuse_evict_inode(struct inode *inode)
127{
128 truncate_inode_pages_final(&inode->i_data);
129 clear_inode(inode);
130 if (inode->i_sb->s_flags & MS_ACTIVE) {
131 struct fuse_conn *fc = get_fuse_conn(inode);
132 struct fuse_inode *fi = get_fuse_inode(inode);
133 fuse_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup);
134 fi->forget = NULL;
135 }
136}
137
138static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
139{
140 sync_filesystem(sb);
141 if (*flags & MS_MANDLOCK)
142 return -EINVAL;
143
144 return 0;
145}
146
147
148
149
150
151static ino_t fuse_squash_ino(u64 ino64)
152{
153 ino_t ino = (ino_t) ino64;
154 if (sizeof(ino_t) < sizeof(u64))
155 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
156 return ino;
157}
158
159void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
160 u64 attr_valid)
161{
162 struct fuse_conn *fc = get_fuse_conn(inode);
163 struct fuse_inode *fi = get_fuse_inode(inode);
164
165 fi->attr_version = ++fc->attr_version;
166 fi->i_time = attr_valid;
167
168 inode->i_ino = fuse_squash_ino(attr->ino);
169 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
170 set_nlink(inode, attr->nlink);
171 inode->i_uid = make_kuid(&init_user_ns, attr->uid);
172 inode->i_gid = make_kgid(&init_user_ns, attr->gid);
173 inode->i_blocks = attr->blocks;
174 inode->i_atime.tv_sec = attr->atime;
175 inode->i_atime.tv_nsec = attr->atimensec;
176
177 if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) {
178 inode->i_mtime.tv_sec = attr->mtime;
179 inode->i_mtime.tv_nsec = attr->mtimensec;
180 inode->i_ctime.tv_sec = attr->ctime;
181 inode->i_ctime.tv_nsec = attr->ctimensec;
182 }
183
184 if (attr->blksize != 0)
185 inode->i_blkbits = ilog2(attr->blksize);
186 else
187 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
188
189
190
191
192
193
194 fi->orig_i_mode = inode->i_mode;
195 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
196 inode->i_mode &= ~S_ISVTX;
197
198 fi->orig_ino = attr->ino;
199}
200
201void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
202 u64 attr_valid, u64 attr_version)
203{
204 struct fuse_conn *fc = get_fuse_conn(inode);
205 struct fuse_inode *fi = get_fuse_inode(inode);
206 bool is_wb = fc->writeback_cache;
207 loff_t oldsize;
208 struct timespec old_mtime;
209
210 spin_lock(&fc->lock);
211 if ((attr_version != 0 && fi->attr_version > attr_version) ||
212 test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
213 spin_unlock(&fc->lock);
214 return;
215 }
216
217 old_mtime = inode->i_mtime;
218 fuse_change_attributes_common(inode, attr, attr_valid);
219
220 oldsize = inode->i_size;
221
222
223
224
225
226 if (!is_wb || !S_ISREG(inode->i_mode))
227 i_size_write(inode, attr->size);
228 spin_unlock(&fc->lock);
229
230 if (!is_wb && S_ISREG(inode->i_mode)) {
231 bool inval = false;
232
233 if (oldsize != attr->size) {
234 truncate_pagecache(inode, attr->size);
235 inval = true;
236 } else if (fc->auto_inval_data) {
237 struct timespec new_mtime = {
238 .tv_sec = attr->mtime,
239 .tv_nsec = attr->mtimensec,
240 };
241
242
243
244
245
246 if (!timespec_equal(&old_mtime, &new_mtime))
247 inval = true;
248 }
249
250 if (inval)
251 invalidate_inode_pages2(inode->i_mapping);
252 }
253}
254
255static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
256{
257 inode->i_mode = attr->mode & S_IFMT;
258 inode->i_size = attr->size;
259 inode->i_mtime.tv_sec = attr->mtime;
260 inode->i_mtime.tv_nsec = attr->mtimensec;
261 inode->i_ctime.tv_sec = attr->ctime;
262 inode->i_ctime.tv_nsec = attr->ctimensec;
263 if (S_ISREG(inode->i_mode)) {
264 fuse_init_common(inode);
265 fuse_init_file_inode(inode);
266 } else if (S_ISDIR(inode->i_mode))
267 fuse_init_dir(inode);
268 else if (S_ISLNK(inode->i_mode))
269 fuse_init_symlink(inode);
270 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
271 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
272 fuse_init_common(inode);
273 init_special_inode(inode, inode->i_mode,
274 new_decode_dev(attr->rdev));
275 } else
276 BUG();
277}
278
279int fuse_inode_eq(struct inode *inode, void *_nodeidp)
280{
281 u64 nodeid = *(u64 *) _nodeidp;
282 if (get_node_id(inode) == nodeid)
283 return 1;
284 else
285 return 0;
286}
287
288static int fuse_inode_set(struct inode *inode, void *_nodeidp)
289{
290 u64 nodeid = *(u64 *) _nodeidp;
291 get_fuse_inode(inode)->nodeid = nodeid;
292 return 0;
293}
294
295struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
296 int generation, struct fuse_attr *attr,
297 u64 attr_valid, u64 attr_version)
298{
299 struct inode *inode;
300 struct fuse_inode *fi;
301 struct fuse_conn *fc = get_fuse_conn_super(sb);
302
303 retry:
304 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
305 if (!inode)
306 return NULL;
307
308 if ((inode->i_state & I_NEW)) {
309 inode->i_flags |= S_NOATIME;
310 if (!fc->writeback_cache || !S_ISREG(attr->mode))
311 inode->i_flags |= S_NOCMTIME;
312 inode->i_generation = generation;
313 fuse_init_inode(inode, attr);
314 unlock_new_inode(inode);
315 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
316
317 make_bad_inode(inode);
318 iput(inode);
319 goto retry;
320 }
321
322 fi = get_fuse_inode(inode);
323 spin_lock(&fc->lock);
324 fi->nlookup++;
325 spin_unlock(&fc->lock);
326 fuse_change_attributes(inode, attr, attr_valid, attr_version);
327
328 return inode;
329}
330
331int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
332 loff_t offset, loff_t len)
333{
334 struct inode *inode;
335 pgoff_t pg_start;
336 pgoff_t pg_end;
337
338 inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
339 if (!inode)
340 return -ENOENT;
341
342 fuse_invalidate_attr(inode);
343 if (offset >= 0) {
344 pg_start = offset >> PAGE_SHIFT;
345 if (len <= 0)
346 pg_end = -1;
347 else
348 pg_end = (offset + len - 1) >> PAGE_SHIFT;
349 invalidate_inode_pages2_range(inode->i_mapping,
350 pg_start, pg_end);
351 }
352 iput(inode);
353 return 0;
354}
355
356void fuse_lock_inode(struct inode *inode)
357{
358 if (!get_fuse_conn(inode)->parallel_dirops)
359 mutex_lock(&get_fuse_inode(inode)->mutex);
360}
361
362void fuse_unlock_inode(struct inode *inode)
363{
364 if (!get_fuse_conn(inode)->parallel_dirops)
365 mutex_unlock(&get_fuse_inode(inode)->mutex);
366}
367
368static void fuse_umount_begin(struct super_block *sb)
369{
370 fuse_abort_conn(get_fuse_conn_super(sb));
371}
372
373static void fuse_send_destroy(struct fuse_conn *fc)
374{
375 struct fuse_req *req = fc->destroy_req;
376 if (req && fc->conn_init) {
377 fc->destroy_req = NULL;
378 req->in.h.opcode = FUSE_DESTROY;
379 __set_bit(FR_FORCE, &req->flags);
380 __clear_bit(FR_BACKGROUND, &req->flags);
381 fuse_request_send(fc, req);
382 fuse_put_request(fc, req);
383 }
384}
385
386static void fuse_bdi_destroy(struct fuse_conn *fc)
387{
388 if (fc->bdi_initialized)
389 bdi_destroy(&fc->bdi);
390}
391
392static void fuse_put_super(struct super_block *sb)
393{
394 struct fuse_conn *fc = get_fuse_conn_super(sb);
395
396 fuse_send_destroy(fc);
397
398 fuse_abort_conn(fc);
399 mutex_lock(&fuse_mutex);
400 list_del(&fc->entry);
401 fuse_ctl_remove_conn(fc);
402 mutex_unlock(&fuse_mutex);
403 fuse_bdi_destroy(fc);
404
405 fuse_conn_put(fc);
406}
407
408static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
409{
410 stbuf->f_type = FUSE_SUPER_MAGIC;
411 stbuf->f_bsize = attr->bsize;
412 stbuf->f_frsize = attr->frsize;
413 stbuf->f_blocks = attr->blocks;
414 stbuf->f_bfree = attr->bfree;
415 stbuf->f_bavail = attr->bavail;
416 stbuf->f_files = attr->files;
417 stbuf->f_ffree = attr->ffree;
418 stbuf->f_namelen = attr->namelen;
419
420}
421
422static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
423{
424 struct super_block *sb = dentry->d_sb;
425 struct fuse_conn *fc = get_fuse_conn_super(sb);
426 FUSE_ARGS(args);
427 struct fuse_statfs_out outarg;
428 int err;
429
430 if (!fuse_allow_current_process(fc)) {
431 buf->f_type = FUSE_SUPER_MAGIC;
432 return 0;
433 }
434
435 memset(&outarg, 0, sizeof(outarg));
436 args.in.numargs = 0;
437 args.in.h.opcode = FUSE_STATFS;
438 args.in.h.nodeid = get_node_id(d_inode(dentry));
439 args.out.numargs = 1;
440 args.out.args[0].size = sizeof(outarg);
441 args.out.args[0].value = &outarg;
442 err = fuse_simple_request(fc, &args);
443 if (!err)
444 convert_fuse_statfs(buf, &outarg.st);
445 return err;
446}
447
448enum {
449 OPT_FD,
450 OPT_ROOTMODE,
451 OPT_USER_ID,
452 OPT_GROUP_ID,
453 OPT_DEFAULT_PERMISSIONS,
454 OPT_ALLOW_OTHER,
455 OPT_MAX_READ,
456 OPT_BLKSIZE,
457 OPT_ERR
458};
459
460static const match_table_t tokens = {
461 {OPT_FD, "fd=%u"},
462 {OPT_ROOTMODE, "rootmode=%o"},
463 {OPT_USER_ID, "user_id=%u"},
464 {OPT_GROUP_ID, "group_id=%u"},
465 {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
466 {OPT_ALLOW_OTHER, "allow_other"},
467 {OPT_MAX_READ, "max_read=%u"},
468 {OPT_BLKSIZE, "blksize=%u"},
469 {OPT_ERR, NULL}
470};
471
472static int fuse_match_uint(substring_t *s, unsigned int *res)
473{
474 int err = -ENOMEM;
475 char *buf = match_strdup(s);
476 if (buf) {
477 err = kstrtouint(buf, 10, res);
478 kfree(buf);
479 }
480 return err;
481}
482
483static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
484{
485 char *p;
486 memset(d, 0, sizeof(struct fuse_mount_data));
487 d->max_read = ~0;
488 d->blksize = FUSE_DEFAULT_BLKSIZE;
489
490 while ((p = strsep(&opt, ",")) != NULL) {
491 int token;
492 int value;
493 unsigned uv;
494 substring_t args[MAX_OPT_ARGS];
495 if (!*p)
496 continue;
497
498 token = match_token(p, tokens, args);
499 switch (token) {
500 case OPT_FD:
501 if (match_int(&args[0], &value))
502 return 0;
503 d->fd = value;
504 d->fd_present = 1;
505 break;
506
507 case OPT_ROOTMODE:
508 if (match_octal(&args[0], &value))
509 return 0;
510 if (!fuse_valid_type(value))
511 return 0;
512 d->rootmode = value;
513 d->rootmode_present = 1;
514 break;
515
516 case OPT_USER_ID:
517 if (fuse_match_uint(&args[0], &uv))
518 return 0;
519 d->user_id = make_kuid(current_user_ns(), uv);
520 if (!uid_valid(d->user_id))
521 return 0;
522 d->user_id_present = 1;
523 break;
524
525 case OPT_GROUP_ID:
526 if (fuse_match_uint(&args[0], &uv))
527 return 0;
528 d->group_id = make_kgid(current_user_ns(), uv);
529 if (!gid_valid(d->group_id))
530 return 0;
531 d->group_id_present = 1;
532 break;
533
534 case OPT_DEFAULT_PERMISSIONS:
535 d->flags |= FUSE_DEFAULT_PERMISSIONS;
536 break;
537
538 case OPT_ALLOW_OTHER:
539 d->flags |= FUSE_ALLOW_OTHER;
540 break;
541
542 case OPT_MAX_READ:
543 if (match_int(&args[0], &value))
544 return 0;
545 d->max_read = value;
546 break;
547
548 case OPT_BLKSIZE:
549 if (!is_bdev || match_int(&args[0], &value))
550 return 0;
551 d->blksize = value;
552 break;
553
554 default:
555 return 0;
556 }
557 }
558
559 if (!d->fd_present || !d->rootmode_present ||
560 !d->user_id_present || !d->group_id_present)
561 return 0;
562
563 return 1;
564}
565
566static int fuse_show_options(struct seq_file *m, struct dentry *root)
567{
568 struct super_block *sb = root->d_sb;
569 struct fuse_conn *fc = get_fuse_conn_super(sb);
570
571 seq_printf(m, ",user_id=%u", from_kuid_munged(&init_user_ns, fc->user_id));
572 seq_printf(m, ",group_id=%u", from_kgid_munged(&init_user_ns, fc->group_id));
573 if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
574 seq_puts(m, ",default_permissions");
575 if (fc->flags & FUSE_ALLOW_OTHER)
576 seq_puts(m, ",allow_other");
577 if (fc->max_read != ~0)
578 seq_printf(m, ",max_read=%u", fc->max_read);
579 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
580 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
581 return 0;
582}
583
584static void fuse_iqueue_init(struct fuse_iqueue *fiq)
585{
586 memset(fiq, 0, sizeof(struct fuse_iqueue));
587 init_waitqueue_head(&fiq->waitq);
588 INIT_LIST_HEAD(&fiq->pending);
589 INIT_LIST_HEAD(&fiq->interrupts);
590 fiq->forget_list_tail = &fiq->forget_list_head;
591 fiq->connected = 1;
592}
593
594static void fuse_pqueue_init(struct fuse_pqueue *fpq)
595{
596 memset(fpq, 0, sizeof(struct fuse_pqueue));
597 spin_lock_init(&fpq->lock);
598 INIT_LIST_HEAD(&fpq->processing);
599 INIT_LIST_HEAD(&fpq->io);
600 fpq->connected = 1;
601}
602
603void fuse_conn_init(struct fuse_conn *fc)
604{
605 memset(fc, 0, sizeof(*fc));
606 spin_lock_init(&fc->lock);
607 init_rwsem(&fc->killsb);
608 atomic_set(&fc->count, 1);
609 atomic_set(&fc->dev_count, 1);
610 init_waitqueue_head(&fc->blocked_waitq);
611 init_waitqueue_head(&fc->reserved_req_waitq);
612 fuse_iqueue_init(&fc->iq);
613 INIT_LIST_HEAD(&fc->bg_queue);
614 INIT_LIST_HEAD(&fc->entry);
615 INIT_LIST_HEAD(&fc->devices);
616 atomic_set(&fc->num_waiting, 0);
617 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
618 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
619 fc->khctr = 0;
620 fc->polled_files = RB_ROOT;
621 fc->blocked = 0;
622 fc->initialized = 0;
623 fc->connected = 1;
624 fc->attr_version = 1;
625 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
626}
627EXPORT_SYMBOL_GPL(fuse_conn_init);
628
629void fuse_conn_put(struct fuse_conn *fc)
630{
631 if (atomic_dec_and_test(&fc->count)) {
632 if (fc->destroy_req)
633 fuse_request_free(fc->destroy_req);
634 fc->release(fc);
635 }
636}
637EXPORT_SYMBOL_GPL(fuse_conn_put);
638
639struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
640{
641 atomic_inc(&fc->count);
642 return fc;
643}
644EXPORT_SYMBOL_GPL(fuse_conn_get);
645
646static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
647{
648 struct fuse_attr attr;
649 memset(&attr, 0, sizeof(attr));
650
651 attr.mode = mode;
652 attr.ino = FUSE_ROOT_ID;
653 attr.nlink = 1;
654 return fuse_iget(sb, 1, 0, &attr, 0, 0);
655}
656
657struct fuse_inode_handle {
658 u64 nodeid;
659 u32 generation;
660};
661
662static struct dentry *fuse_get_dentry(struct super_block *sb,
663 struct fuse_inode_handle *handle)
664{
665 struct fuse_conn *fc = get_fuse_conn_super(sb);
666 struct inode *inode;
667 struct dentry *entry;
668 int err = -ESTALE;
669
670 if (handle->nodeid == 0)
671 goto out_err;
672
673 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
674 if (!inode) {
675 struct fuse_entry_out outarg;
676 const struct qstr name = QSTR_INIT(".", 1);
677
678 if (!fc->export_support)
679 goto out_err;
680
681 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
682 &inode);
683 if (err && err != -ENOENT)
684 goto out_err;
685 if (err || !inode) {
686 err = -ESTALE;
687 goto out_err;
688 }
689 err = -EIO;
690 if (get_node_id(inode) != handle->nodeid)
691 goto out_iput;
692 }
693 err = -ESTALE;
694 if (inode->i_generation != handle->generation)
695 goto out_iput;
696
697 entry = d_obtain_alias(inode);
698 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
699 fuse_invalidate_entry_cache(entry);
700
701 return entry;
702
703 out_iput:
704 iput(inode);
705 out_err:
706 return ERR_PTR(err);
707}
708
709static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
710 struct inode *parent)
711{
712 int len = parent ? 6 : 3;
713 u64 nodeid;
714 u32 generation;
715
716 if (*max_len < len) {
717 *max_len = len;
718 return FILEID_INVALID;
719 }
720
721 nodeid = get_fuse_inode(inode)->nodeid;
722 generation = inode->i_generation;
723
724 fh[0] = (u32)(nodeid >> 32);
725 fh[1] = (u32)(nodeid & 0xffffffff);
726 fh[2] = generation;
727
728 if (parent) {
729 nodeid = get_fuse_inode(parent)->nodeid;
730 generation = parent->i_generation;
731
732 fh[3] = (u32)(nodeid >> 32);
733 fh[4] = (u32)(nodeid & 0xffffffff);
734 fh[5] = generation;
735 }
736
737 *max_len = len;
738 return parent ? 0x82 : 0x81;
739}
740
741static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
742 struct fid *fid, int fh_len, int fh_type)
743{
744 struct fuse_inode_handle handle;
745
746 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
747 return NULL;
748
749 handle.nodeid = (u64) fid->raw[0] << 32;
750 handle.nodeid |= (u64) fid->raw[1];
751 handle.generation = fid->raw[2];
752 return fuse_get_dentry(sb, &handle);
753}
754
755static struct dentry *fuse_fh_to_parent(struct super_block *sb,
756 struct fid *fid, int fh_len, int fh_type)
757{
758 struct fuse_inode_handle parent;
759
760 if (fh_type != 0x82 || fh_len < 6)
761 return NULL;
762
763 parent.nodeid = (u64) fid->raw[3] << 32;
764 parent.nodeid |= (u64) fid->raw[4];
765 parent.generation = fid->raw[5];
766 return fuse_get_dentry(sb, &parent);
767}
768
769static struct dentry *fuse_get_parent(struct dentry *child)
770{
771 struct inode *child_inode = d_inode(child);
772 struct fuse_conn *fc = get_fuse_conn(child_inode);
773 struct inode *inode;
774 struct dentry *parent;
775 struct fuse_entry_out outarg;
776 const struct qstr name = QSTR_INIT("..", 2);
777 int err;
778
779 if (!fc->export_support)
780 return ERR_PTR(-ESTALE);
781
782 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
783 &name, &outarg, &inode);
784 if (err) {
785 if (err == -ENOENT)
786 return ERR_PTR(-ESTALE);
787 return ERR_PTR(err);
788 }
789
790 parent = d_obtain_alias(inode);
791 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
792 fuse_invalidate_entry_cache(parent);
793
794 return parent;
795}
796
797static const struct export_operations fuse_export_operations = {
798 .fh_to_dentry = fuse_fh_to_dentry,
799 .fh_to_parent = fuse_fh_to_parent,
800 .encode_fh = fuse_encode_fh,
801 .get_parent = fuse_get_parent,
802};
803
804static const struct super_operations fuse_super_operations = {
805 .alloc_inode = fuse_alloc_inode,
806 .destroy_inode = fuse_destroy_inode,
807 .evict_inode = fuse_evict_inode,
808 .write_inode = fuse_write_inode,
809 .drop_inode = generic_delete_inode,
810 .remount_fs = fuse_remount_fs,
811 .put_super = fuse_put_super,
812 .umount_begin = fuse_umount_begin,
813 .statfs = fuse_statfs,
814 .show_options = fuse_show_options,
815};
816
817static void sanitize_global_limit(unsigned *limit)
818{
819 if (*limit == 0)
820 *limit = ((totalram_pages << PAGE_SHIFT) >> 13) /
821 sizeof(struct fuse_req);
822
823 if (*limit >= 1 << 16)
824 *limit = (1 << 16) - 1;
825}
826
827static int set_global_limit(const char *val, struct kernel_param *kp)
828{
829 int rv;
830
831 rv = param_set_uint(val, kp);
832 if (rv)
833 return rv;
834
835 sanitize_global_limit((unsigned *)kp->arg);
836
837 return 0;
838}
839
840static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
841{
842 int cap_sys_admin = capable(CAP_SYS_ADMIN);
843
844 if (arg->minor < 13)
845 return;
846
847 sanitize_global_limit(&max_user_bgreq);
848 sanitize_global_limit(&max_user_congthresh);
849
850 if (arg->max_background) {
851 fc->max_background = arg->max_background;
852
853 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
854 fc->max_background = max_user_bgreq;
855 }
856 if (arg->congestion_threshold) {
857 fc->congestion_threshold = arg->congestion_threshold;
858
859 if (!cap_sys_admin &&
860 fc->congestion_threshold > max_user_congthresh)
861 fc->congestion_threshold = max_user_congthresh;
862 }
863}
864
865static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
866{
867 struct fuse_init_out *arg = &req->misc.init_out;
868
869 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
870 fc->conn_error = 1;
871 else {
872 unsigned long ra_pages;
873
874 process_init_limits(fc, arg);
875
876 if (arg->minor >= 6) {
877 ra_pages = arg->max_readahead / PAGE_SIZE;
878 if (arg->flags & FUSE_ASYNC_READ)
879 fc->async_read = 1;
880 if (!(arg->flags & FUSE_POSIX_LOCKS))
881 fc->no_lock = 1;
882 if (arg->minor >= 17) {
883 if (!(arg->flags & FUSE_FLOCK_LOCKS))
884 fc->no_flock = 1;
885 } else {
886 if (!(arg->flags & FUSE_POSIX_LOCKS))
887 fc->no_flock = 1;
888 }
889 if (arg->flags & FUSE_ATOMIC_O_TRUNC)
890 fc->atomic_o_trunc = 1;
891 if (arg->minor >= 9) {
892
893 if (arg->flags & FUSE_EXPORT_SUPPORT)
894 fc->export_support = 1;
895 }
896 if (arg->flags & FUSE_BIG_WRITES)
897 fc->big_writes = 1;
898 if (arg->flags & FUSE_DONT_MASK)
899 fc->dont_mask = 1;
900 if (arg->flags & FUSE_AUTO_INVAL_DATA)
901 fc->auto_inval_data = 1;
902 if (arg->flags & FUSE_DO_READDIRPLUS) {
903 fc->do_readdirplus = 1;
904 if (arg->flags & FUSE_READDIRPLUS_AUTO)
905 fc->readdirplus_auto = 1;
906 }
907 if (arg->flags & FUSE_ASYNC_DIO)
908 fc->async_dio = 1;
909 if (arg->flags & FUSE_WRITEBACK_CACHE)
910 fc->writeback_cache = 1;
911 if (arg->flags & FUSE_PARALLEL_DIROPS)
912 fc->parallel_dirops = 1;
913 if (arg->time_gran && arg->time_gran <= 1000000000)
914 fc->sb->s_time_gran = arg->time_gran;
915 } else {
916 ra_pages = fc->max_read / PAGE_SIZE;
917 fc->no_lock = 1;
918 fc->no_flock = 1;
919 }
920
921 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
922 fc->minor = arg->minor;
923 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
924 fc->max_write = max_t(unsigned, 4096, fc->max_write);
925 fc->conn_init = 1;
926 }
927 fuse_set_initialized(fc);
928 wake_up_all(&fc->blocked_waitq);
929}
930
931static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
932{
933 struct fuse_init_in *arg = &req->misc.init_in;
934
935 arg->major = FUSE_KERNEL_VERSION;
936 arg->minor = FUSE_KERNEL_MINOR_VERSION;
937 arg->max_readahead = fc->bdi.ra_pages * PAGE_SIZE;
938 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
939 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
940 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
941 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
942 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
943 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT |
944 FUSE_PARALLEL_DIROPS;
945 req->in.h.opcode = FUSE_INIT;
946 req->in.numargs = 1;
947 req->in.args[0].size = sizeof(*arg);
948 req->in.args[0].value = arg;
949 req->out.numargs = 1;
950
951
952
953 req->out.argvar = 1;
954 req->out.args[0].size = sizeof(struct fuse_init_out);
955 req->out.args[0].value = &req->misc.init_out;
956 req->end = process_init_reply;
957 fuse_request_send_background(fc, req);
958}
959
960static void fuse_free_conn(struct fuse_conn *fc)
961{
962 WARN_ON(!list_empty(&fc->devices));
963 kfree_rcu(fc, rcu);
964}
965
966static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
967{
968 int err;
969
970 fc->bdi.name = "fuse";
971 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_SIZE;
972
973 fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
974
975 err = bdi_init(&fc->bdi);
976 if (err)
977 return err;
978
979 fc->bdi_initialized = 1;
980
981 if (sb->s_bdev) {
982 err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
983 MAJOR(fc->dev), MINOR(fc->dev));
984 } else {
985 err = bdi_register_dev(&fc->bdi, fc->dev);
986 }
987
988 if (err)
989 return err;
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003 bdi_set_max_ratio(&fc->bdi, 1);
1004
1005 return 0;
1006}
1007
1008struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc)
1009{
1010 struct fuse_dev *fud;
1011
1012 fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL);
1013 if (fud) {
1014 fud->fc = fuse_conn_get(fc);
1015 fuse_pqueue_init(&fud->pq);
1016
1017 spin_lock(&fc->lock);
1018 list_add_tail(&fud->entry, &fc->devices);
1019 spin_unlock(&fc->lock);
1020 }
1021
1022 return fud;
1023}
1024EXPORT_SYMBOL_GPL(fuse_dev_alloc);
1025
1026void fuse_dev_free(struct fuse_dev *fud)
1027{
1028 struct fuse_conn *fc = fud->fc;
1029
1030 if (fc) {
1031 spin_lock(&fc->lock);
1032 list_del(&fud->entry);
1033 spin_unlock(&fc->lock);
1034
1035 fuse_conn_put(fc);
1036 }
1037 kfree(fud);
1038}
1039EXPORT_SYMBOL_GPL(fuse_dev_free);
1040
1041static int fuse_fill_super(struct super_block *sb, void *data, int silent)
1042{
1043 struct fuse_dev *fud;
1044 struct fuse_conn *fc;
1045 struct inode *root;
1046 struct fuse_mount_data d;
1047 struct file *file;
1048 struct dentry *root_dentry;
1049 struct fuse_req *init_req;
1050 int err;
1051 int is_bdev = sb->s_bdev != NULL;
1052
1053 err = -EINVAL;
1054 if (sb->s_flags & MS_MANDLOCK)
1055 goto err;
1056
1057 sb->s_flags &= ~(MS_NOSEC | MS_I_VERSION);
1058
1059 if (!parse_fuse_opt(data, &d, is_bdev))
1060 goto err;
1061
1062 if (is_bdev) {
1063#ifdef CONFIG_BLOCK
1064 err = -EINVAL;
1065 if (!sb_set_blocksize(sb, d.blksize))
1066 goto err;
1067#endif
1068 } else {
1069 sb->s_blocksize = PAGE_SIZE;
1070 sb->s_blocksize_bits = PAGE_SHIFT;
1071 }
1072 sb->s_magic = FUSE_SUPER_MAGIC;
1073 sb->s_op = &fuse_super_operations;
1074 sb->s_maxbytes = MAX_LFS_FILESIZE;
1075 sb->s_time_gran = 1;
1076 sb->s_export_op = &fuse_export_operations;
1077
1078 file = fget(d.fd);
1079 err = -EINVAL;
1080 if (!file)
1081 goto err;
1082
1083 if ((file->f_op != &fuse_dev_operations) ||
1084 (file->f_cred->user_ns != &init_user_ns))
1085 goto err_fput;
1086
1087 fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1088 err = -ENOMEM;
1089 if (!fc)
1090 goto err_fput;
1091
1092 fuse_conn_init(fc);
1093 fc->release = fuse_free_conn;
1094
1095 fud = fuse_dev_alloc(fc);
1096 if (!fud)
1097 goto err_put_conn;
1098
1099 fc->dev = sb->s_dev;
1100 fc->sb = sb;
1101 err = fuse_bdi_init(fc, sb);
1102 if (err)
1103 goto err_dev_free;
1104
1105 sb->s_bdi = &fc->bdi;
1106
1107
1108 if (sb->s_flags & MS_POSIXACL)
1109 fc->dont_mask = 1;
1110 sb->s_flags |= MS_POSIXACL;
1111
1112 fc->flags = d.flags;
1113 fc->user_id = d.user_id;
1114 fc->group_id = d.group_id;
1115 fc->max_read = max_t(unsigned, 4096, d.max_read);
1116
1117
1118 sb->s_fs_info = fc;
1119
1120 err = -ENOMEM;
1121 root = fuse_get_root_inode(sb, d.rootmode);
1122 root_dentry = d_make_root(root);
1123 if (!root_dentry)
1124 goto err_dev_free;
1125
1126 sb->s_d_op = &fuse_dentry_operations;
1127
1128 init_req = fuse_request_alloc(0);
1129 if (!init_req)
1130 goto err_put_root;
1131 __set_bit(FR_BACKGROUND, &init_req->flags);
1132
1133 if (is_bdev) {
1134 fc->destroy_req = fuse_request_alloc(0);
1135 if (!fc->destroy_req)
1136 goto err_free_init_req;
1137 }
1138
1139 mutex_lock(&fuse_mutex);
1140 err = -EINVAL;
1141 if (file->private_data)
1142 goto err_unlock;
1143
1144 err = fuse_ctl_add_conn(fc);
1145 if (err)
1146 goto err_unlock;
1147
1148 list_add_tail(&fc->entry, &fuse_conn_list);
1149 sb->s_root = root_dentry;
1150 file->private_data = fud;
1151 mutex_unlock(&fuse_mutex);
1152
1153
1154
1155
1156
1157 fput(file);
1158
1159 fuse_send_init(fc, init_req);
1160
1161 return 0;
1162
1163 err_unlock:
1164 mutex_unlock(&fuse_mutex);
1165 err_free_init_req:
1166 fuse_request_free(init_req);
1167 err_put_root:
1168 dput(root_dentry);
1169 err_dev_free:
1170 fuse_dev_free(fud);
1171 err_put_conn:
1172 fuse_bdi_destroy(fc);
1173 fuse_conn_put(fc);
1174 err_fput:
1175 fput(file);
1176 err:
1177 return err;
1178}
1179
1180static struct dentry *fuse_mount(struct file_system_type *fs_type,
1181 int flags, const char *dev_name,
1182 void *raw_data)
1183{
1184 return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1185}
1186
1187static void fuse_kill_sb_anon(struct super_block *sb)
1188{
1189 struct fuse_conn *fc = get_fuse_conn_super(sb);
1190
1191 if (fc) {
1192 down_write(&fc->killsb);
1193 fc->sb = NULL;
1194 up_write(&fc->killsb);
1195 }
1196
1197 kill_anon_super(sb);
1198}
1199
1200static struct file_system_type fuse_fs_type = {
1201 .owner = THIS_MODULE,
1202 .name = "fuse",
1203 .fs_flags = FS_HAS_SUBTYPE,
1204 .mount = fuse_mount,
1205 .kill_sb = fuse_kill_sb_anon,
1206};
1207MODULE_ALIAS_FS("fuse");
1208
1209#ifdef CONFIG_BLOCK
1210static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1211 int flags, const char *dev_name,
1212 void *raw_data)
1213{
1214 return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1215}
1216
1217static void fuse_kill_sb_blk(struct super_block *sb)
1218{
1219 struct fuse_conn *fc = get_fuse_conn_super(sb);
1220
1221 if (fc) {
1222 down_write(&fc->killsb);
1223 fc->sb = NULL;
1224 up_write(&fc->killsb);
1225 }
1226
1227 kill_block_super(sb);
1228}
1229
1230static struct file_system_type fuseblk_fs_type = {
1231 .owner = THIS_MODULE,
1232 .name = "fuseblk",
1233 .mount = fuse_mount_blk,
1234 .kill_sb = fuse_kill_sb_blk,
1235 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1236};
1237MODULE_ALIAS_FS("fuseblk");
1238
1239static inline int register_fuseblk(void)
1240{
1241 return register_filesystem(&fuseblk_fs_type);
1242}
1243
1244static inline void unregister_fuseblk(void)
1245{
1246 unregister_filesystem(&fuseblk_fs_type);
1247}
1248#else
1249static inline int register_fuseblk(void)
1250{
1251 return 0;
1252}
1253
1254static inline void unregister_fuseblk(void)
1255{
1256}
1257#endif
1258
1259static void fuse_inode_init_once(void *foo)
1260{
1261 struct inode *inode = foo;
1262
1263 inode_init_once(inode);
1264}
1265
1266static int __init fuse_fs_init(void)
1267{
1268 int err;
1269
1270 fuse_inode_cachep = kmem_cache_create("fuse_inode",
1271 sizeof(struct fuse_inode), 0,
1272 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT,
1273 fuse_inode_init_once);
1274 err = -ENOMEM;
1275 if (!fuse_inode_cachep)
1276 goto out;
1277
1278 err = register_fuseblk();
1279 if (err)
1280 goto out2;
1281
1282 err = register_filesystem(&fuse_fs_type);
1283 if (err)
1284 goto out3;
1285
1286 return 0;
1287
1288 out3:
1289 unregister_fuseblk();
1290 out2:
1291 kmem_cache_destroy(fuse_inode_cachep);
1292 out:
1293 return err;
1294}
1295
1296static void fuse_fs_cleanup(void)
1297{
1298 unregister_filesystem(&fuse_fs_type);
1299 unregister_fuseblk();
1300
1301
1302
1303
1304
1305 rcu_barrier();
1306 kmem_cache_destroy(fuse_inode_cachep);
1307}
1308
1309static struct kobject *fuse_kobj;
1310
1311static int fuse_sysfs_init(void)
1312{
1313 int err;
1314
1315 fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1316 if (!fuse_kobj) {
1317 err = -ENOMEM;
1318 goto out_err;
1319 }
1320
1321 err = sysfs_create_mount_point(fuse_kobj, "connections");
1322 if (err)
1323 goto out_fuse_unregister;
1324
1325 return 0;
1326
1327 out_fuse_unregister:
1328 kobject_put(fuse_kobj);
1329 out_err:
1330 return err;
1331}
1332
1333static void fuse_sysfs_cleanup(void)
1334{
1335 sysfs_remove_mount_point(fuse_kobj, "connections");
1336 kobject_put(fuse_kobj);
1337}
1338
1339static int __init fuse_init(void)
1340{
1341 int res;
1342
1343 printk(KERN_INFO "fuse init (API version %i.%i)\n",
1344 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1345
1346 INIT_LIST_HEAD(&fuse_conn_list);
1347 res = fuse_fs_init();
1348 if (res)
1349 goto err;
1350
1351 res = fuse_dev_init();
1352 if (res)
1353 goto err_fs_cleanup;
1354
1355 res = fuse_sysfs_init();
1356 if (res)
1357 goto err_dev_cleanup;
1358
1359 res = fuse_ctl_init();
1360 if (res)
1361 goto err_sysfs_cleanup;
1362
1363 sanitize_global_limit(&max_user_bgreq);
1364 sanitize_global_limit(&max_user_congthresh);
1365
1366 return 0;
1367
1368 err_sysfs_cleanup:
1369 fuse_sysfs_cleanup();
1370 err_dev_cleanup:
1371 fuse_dev_cleanup();
1372 err_fs_cleanup:
1373 fuse_fs_cleanup();
1374 err:
1375 return res;
1376}
1377
1378static void __exit fuse_exit(void)
1379{
1380 printk(KERN_DEBUG "fuse exit\n");
1381
1382 fuse_ctl_cleanup();
1383 fuse_sysfs_cleanup();
1384 fuse_fs_cleanup();
1385 fuse_dev_cleanup();
1386}
1387
1388module_init(fuse_init);
1389module_exit(fuse_exit);
1390
