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