2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
5 This program can be distributed under the terms of the GNU GPL.
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 #include <linux/posix_acl.h>
25 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
26 MODULE_DESCRIPTION("Filesystem in Userspace");
27 MODULE_LICENSE("GPL");
29 static struct kmem_cache *fuse_inode_cachep;
30 struct list_head fuse_conn_list;
31 DEFINE_MUTEX(fuse_mutex);
33 static int set_global_limit(const char *val, struct kernel_param *kp);
35 unsigned max_user_bgreq;
36 module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
37 &max_user_bgreq, 0644);
38 __MODULE_PARM_TYPE(max_user_bgreq, "uint");
39 MODULE_PARM_DESC(max_user_bgreq,
40 "Global limit for the maximum number of backgrounded requests an "
41 "unprivileged user can set");
43 unsigned max_user_congthresh;
44 module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
45 &max_user_congthresh, 0644);
46 __MODULE_PARM_TYPE(max_user_congthresh, "uint");
47 MODULE_PARM_DESC(max_user_congthresh,
48 "Global limit for the maximum congestion threshold an "
49 "unprivileged user can set");
51 #define FUSE_SUPER_MAGIC 0x65735546
53 #define FUSE_DEFAULT_BLKSIZE 512
55 /** Maximum number of outstanding background requests */
56 #define FUSE_DEFAULT_MAX_BACKGROUND 12
58 /** Congestion starts at 75% of maximum */
59 #define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
61 struct fuse_mount_data {
66 unsigned fd_present:1;
67 unsigned rootmode_present:1;
68 unsigned user_id_present:1;
69 unsigned group_id_present:1;
70 unsigned default_permissions:1;
71 unsigned allow_other:1;
76 struct fuse_forget_link *fuse_alloc_forget(void)
78 return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL);
81 static struct inode *fuse_alloc_inode(struct super_block *sb)
84 struct fuse_inode *fi;
86 inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
90 fi = get_fuse_inode(inode);
98 INIT_LIST_HEAD(&fi->write_files);
99 INIT_LIST_HEAD(&fi->queued_writes);
100 INIT_LIST_HEAD(&fi->writepages);
101 init_waitqueue_head(&fi->page_waitq);
102 mutex_init(&fi->mutex);
103 fi->forget = fuse_alloc_forget();
105 kmem_cache_free(fuse_inode_cachep, inode);
112 static void fuse_i_callback(struct rcu_head *head)
114 struct inode *inode = container_of(head, struct inode, i_rcu);
115 kmem_cache_free(fuse_inode_cachep, inode);
118 static void fuse_destroy_inode(struct inode *inode)
120 struct fuse_inode *fi = get_fuse_inode(inode);
121 BUG_ON(!list_empty(&fi->write_files));
122 BUG_ON(!list_empty(&fi->queued_writes));
123 mutex_destroy(&fi->mutex);
125 call_rcu(&inode->i_rcu, fuse_i_callback);
128 static void fuse_evict_inode(struct inode *inode)
130 truncate_inode_pages_final(&inode->i_data);
132 if (inode->i_sb->s_flags & MS_ACTIVE) {
133 struct fuse_conn *fc = get_fuse_conn(inode);
134 struct fuse_inode *fi = get_fuse_inode(inode);
135 fuse_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup);
140 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
143 if (*flags & MS_MANDLOCK)
150 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
151 * so that it will fit.
153 static ino_t fuse_squash_ino(u64 ino64)
155 ino_t ino = (ino_t) ino64;
156 if (sizeof(ino_t) < sizeof(u64))
157 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
161 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
164 struct fuse_conn *fc = get_fuse_conn(inode);
165 struct fuse_inode *fi = get_fuse_inode(inode);
167 fi->attr_version = ++fc->attr_version;
168 fi->i_time = attr_valid;
170 inode->i_ino = fuse_squash_ino(attr->ino);
171 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
172 set_nlink(inode, attr->nlink);
173 inode->i_uid = make_kuid(&init_user_ns, attr->uid);
174 inode->i_gid = make_kgid(&init_user_ns, attr->gid);
175 inode->i_blocks = attr->blocks;
176 inode->i_atime.tv_sec = attr->atime;
177 inode->i_atime.tv_nsec = attr->atimensec;
178 /* mtime from server may be stale due to local buffered write */
179 if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) {
180 inode->i_mtime.tv_sec = attr->mtime;
181 inode->i_mtime.tv_nsec = attr->mtimensec;
182 inode->i_ctime.tv_sec = attr->ctime;
183 inode->i_ctime.tv_nsec = attr->ctimensec;
186 if (attr->blksize != 0)
187 inode->i_blkbits = ilog2(attr->blksize);
189 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
192 * Don't set the sticky bit in i_mode, unless we want the VFS
193 * to check permissions. This prevents failures due to the
194 * check in may_delete().
196 fi->orig_i_mode = inode->i_mode;
197 if (!fc->default_permissions)
198 inode->i_mode &= ~S_ISVTX;
200 fi->orig_ino = attr->ino;
203 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
204 u64 attr_valid, u64 attr_version)
206 struct fuse_conn *fc = get_fuse_conn(inode);
207 struct fuse_inode *fi = get_fuse_inode(inode);
208 bool is_wb = fc->writeback_cache;
210 struct timespec old_mtime;
212 spin_lock(&fc->lock);
213 if ((attr_version != 0 && fi->attr_version > attr_version) ||
214 test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
215 spin_unlock(&fc->lock);
219 old_mtime = inode->i_mtime;
220 fuse_change_attributes_common(inode, attr, attr_valid);
222 oldsize = inode->i_size;
224 * In case of writeback_cache enabled, the cached writes beyond EOF
225 * extend local i_size without keeping userspace server in sync. So,
226 * attr->size coming from server can be stale. We cannot trust it.
228 if (!is_wb || !S_ISREG(inode->i_mode))
229 i_size_write(inode, attr->size);
230 spin_unlock(&fc->lock);
232 if (!is_wb && S_ISREG(inode->i_mode)) {
235 if (oldsize != attr->size) {
236 truncate_pagecache(inode, attr->size);
238 } else if (fc->auto_inval_data) {
239 struct timespec new_mtime = {
240 .tv_sec = attr->mtime,
241 .tv_nsec = attr->mtimensec,
245 * Auto inval mode also checks and invalidates if mtime
248 if (!timespec_equal(&old_mtime, &new_mtime))
253 invalidate_inode_pages2(inode->i_mapping);
257 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
259 inode->i_mode = attr->mode & S_IFMT;
260 inode->i_size = attr->size;
261 inode->i_mtime.tv_sec = attr->mtime;
262 inode->i_mtime.tv_nsec = attr->mtimensec;
263 inode->i_ctime.tv_sec = attr->ctime;
264 inode->i_ctime.tv_nsec = attr->ctimensec;
265 if (S_ISREG(inode->i_mode)) {
266 fuse_init_common(inode);
267 fuse_init_file_inode(inode);
268 } else if (S_ISDIR(inode->i_mode))
269 fuse_init_dir(inode);
270 else if (S_ISLNK(inode->i_mode))
271 fuse_init_symlink(inode);
272 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
273 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
274 fuse_init_common(inode);
275 init_special_inode(inode, inode->i_mode,
276 new_decode_dev(attr->rdev));
281 int fuse_inode_eq(struct inode *inode, void *_nodeidp)
283 u64 nodeid = *(u64 *) _nodeidp;
284 if (get_node_id(inode) == nodeid)
290 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
292 u64 nodeid = *(u64 *) _nodeidp;
293 get_fuse_inode(inode)->nodeid = nodeid;
297 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
298 int generation, struct fuse_attr *attr,
299 u64 attr_valid, u64 attr_version)
302 struct fuse_inode *fi;
303 struct fuse_conn *fc = get_fuse_conn_super(sb);
306 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
310 if ((inode->i_state & I_NEW)) {
311 inode->i_flags |= S_NOATIME;
312 if (!fc->writeback_cache || !S_ISREG(attr->mode))
313 inode->i_flags |= S_NOCMTIME;
314 inode->i_generation = generation;
315 fuse_init_inode(inode, attr);
316 unlock_new_inode(inode);
317 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
318 /* Inode has changed type, any I/O on the old should fail */
319 make_bad_inode(inode);
324 fi = get_fuse_inode(inode);
325 spin_lock(&fc->lock);
327 spin_unlock(&fc->lock);
328 fuse_change_attributes(inode, attr, attr_valid, attr_version);
333 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
334 loff_t offset, loff_t len)
340 inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
344 fuse_invalidate_attr(inode);
345 forget_all_cached_acls(inode);
347 pg_start = offset >> PAGE_SHIFT;
351 pg_end = (offset + len - 1) >> PAGE_SHIFT;
352 invalidate_inode_pages2_range(inode->i_mapping,
359 void fuse_lock_inode(struct inode *inode)
361 if (!get_fuse_conn(inode)->parallel_dirops)
362 mutex_lock(&get_fuse_inode(inode)->mutex);
365 void fuse_unlock_inode(struct inode *inode)
367 if (!get_fuse_conn(inode)->parallel_dirops)
368 mutex_unlock(&get_fuse_inode(inode)->mutex);
371 static void fuse_umount_begin(struct super_block *sb)
373 fuse_abort_conn(get_fuse_conn_super(sb));
376 static void fuse_send_destroy(struct fuse_conn *fc)
378 struct fuse_req *req = fc->destroy_req;
379 if (req && fc->conn_init) {
380 fc->destroy_req = NULL;
381 req->in.h.opcode = FUSE_DESTROY;
382 __set_bit(FR_FORCE, &req->flags);
383 __clear_bit(FR_BACKGROUND, &req->flags);
384 fuse_request_send(fc, req);
385 fuse_put_request(fc, req);
389 static void fuse_put_super(struct super_block *sb)
391 struct fuse_conn *fc = get_fuse_conn_super(sb);
393 fuse_send_destroy(fc);
396 mutex_lock(&fuse_mutex);
397 list_del(&fc->entry);
398 fuse_ctl_remove_conn(fc);
399 mutex_unlock(&fuse_mutex);
404 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
406 stbuf->f_type = FUSE_SUPER_MAGIC;
407 stbuf->f_bsize = attr->bsize;
408 stbuf->f_frsize = attr->frsize;
409 stbuf->f_blocks = attr->blocks;
410 stbuf->f_bfree = attr->bfree;
411 stbuf->f_bavail = attr->bavail;
412 stbuf->f_files = attr->files;
413 stbuf->f_ffree = attr->ffree;
414 stbuf->f_namelen = attr->namelen;
415 /* fsid is left zero */
418 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
420 struct super_block *sb = dentry->d_sb;
421 struct fuse_conn *fc = get_fuse_conn_super(sb);
423 struct fuse_statfs_out outarg;
426 if (!fuse_allow_current_process(fc)) {
427 buf->f_type = FUSE_SUPER_MAGIC;
431 memset(&outarg, 0, sizeof(outarg));
433 args.in.h.opcode = FUSE_STATFS;
434 args.in.h.nodeid = get_node_id(d_inode(dentry));
435 args.out.numargs = 1;
436 args.out.args[0].size = sizeof(outarg);
437 args.out.args[0].value = &outarg;
438 err = fuse_simple_request(fc, &args);
440 convert_fuse_statfs(buf, &outarg.st);
449 OPT_DEFAULT_PERMISSIONS,
456 static const match_table_t tokens = {
458 {OPT_ROOTMODE, "rootmode=%o"},
459 {OPT_USER_ID, "user_id=%u"},
460 {OPT_GROUP_ID, "group_id=%u"},
461 {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
462 {OPT_ALLOW_OTHER, "allow_other"},
463 {OPT_MAX_READ, "max_read=%u"},
464 {OPT_BLKSIZE, "blksize=%u"},
468 static int fuse_match_uint(substring_t *s, unsigned int *res)
471 char *buf = match_strdup(s);
473 err = kstrtouint(buf, 10, res);
479 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
482 memset(d, 0, sizeof(struct fuse_mount_data));
484 d->blksize = FUSE_DEFAULT_BLKSIZE;
486 while ((p = strsep(&opt, ",")) != NULL) {
490 substring_t args[MAX_OPT_ARGS];
494 token = match_token(p, tokens, args);
497 if (match_int(&args[0], &value))
504 if (match_octal(&args[0], &value))
506 if (!fuse_valid_type(value))
509 d->rootmode_present = 1;
513 if (fuse_match_uint(&args[0], &uv))
515 d->user_id = make_kuid(current_user_ns(), uv);
516 if (!uid_valid(d->user_id))
518 d->user_id_present = 1;
522 if (fuse_match_uint(&args[0], &uv))
524 d->group_id = make_kgid(current_user_ns(), uv);
525 if (!gid_valid(d->group_id))
527 d->group_id_present = 1;
530 case OPT_DEFAULT_PERMISSIONS:
531 d->default_permissions = 1;
534 case OPT_ALLOW_OTHER:
539 if (match_int(&args[0], &value))
545 if (!is_bdev || match_int(&args[0], &value))
555 if (!d->fd_present || !d->rootmode_present ||
556 !d->user_id_present || !d->group_id_present)
562 static int fuse_show_options(struct seq_file *m, struct dentry *root)
564 struct super_block *sb = root->d_sb;
565 struct fuse_conn *fc = get_fuse_conn_super(sb);
567 seq_printf(m, ",user_id=%u", from_kuid_munged(&init_user_ns, fc->user_id));
568 seq_printf(m, ",group_id=%u", from_kgid_munged(&init_user_ns, fc->group_id));
569 if (fc->default_permissions)
570 seq_puts(m, ",default_permissions");
572 seq_puts(m, ",allow_other");
573 if (fc->max_read != ~0)
574 seq_printf(m, ",max_read=%u", fc->max_read);
575 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
576 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
580 static void fuse_iqueue_init(struct fuse_iqueue *fiq)
582 memset(fiq, 0, sizeof(struct fuse_iqueue));
583 init_waitqueue_head(&fiq->waitq);
584 INIT_LIST_HEAD(&fiq->pending);
585 INIT_LIST_HEAD(&fiq->interrupts);
586 fiq->forget_list_tail = &fiq->forget_list_head;
590 static void fuse_pqueue_init(struct fuse_pqueue *fpq)
592 memset(fpq, 0, sizeof(struct fuse_pqueue));
593 spin_lock_init(&fpq->lock);
594 INIT_LIST_HEAD(&fpq->processing);
595 INIT_LIST_HEAD(&fpq->io);
599 void fuse_conn_init(struct fuse_conn *fc)
601 memset(fc, 0, sizeof(*fc));
602 spin_lock_init(&fc->lock);
603 init_rwsem(&fc->killsb);
604 atomic_set(&fc->count, 1);
605 atomic_set(&fc->dev_count, 1);
606 init_waitqueue_head(&fc->blocked_waitq);
607 init_waitqueue_head(&fc->reserved_req_waitq);
608 fuse_iqueue_init(&fc->iq);
609 INIT_LIST_HEAD(&fc->bg_queue);
610 INIT_LIST_HEAD(&fc->entry);
611 INIT_LIST_HEAD(&fc->devices);
612 atomic_set(&fc->num_waiting, 0);
613 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
614 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
616 fc->polled_files = RB_ROOT;
620 fc->attr_version = 1;
621 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
623 EXPORT_SYMBOL_GPL(fuse_conn_init);
625 void fuse_conn_put(struct fuse_conn *fc)
627 if (atomic_dec_and_test(&fc->count)) {
629 fuse_request_free(fc->destroy_req);
633 EXPORT_SYMBOL_GPL(fuse_conn_put);
635 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
637 atomic_inc(&fc->count);
640 EXPORT_SYMBOL_GPL(fuse_conn_get);
642 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
644 struct fuse_attr attr;
645 memset(&attr, 0, sizeof(attr));
648 attr.ino = FUSE_ROOT_ID;
650 return fuse_iget(sb, 1, 0, &attr, 0, 0);
653 struct fuse_inode_handle {
658 static struct dentry *fuse_get_dentry(struct super_block *sb,
659 struct fuse_inode_handle *handle)
661 struct fuse_conn *fc = get_fuse_conn_super(sb);
663 struct dentry *entry;
666 if (handle->nodeid == 0)
669 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
671 struct fuse_entry_out outarg;
672 const struct qstr name = QSTR_INIT(".", 1);
674 if (!fc->export_support)
677 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
679 if (err && err != -ENOENT)
686 if (get_node_id(inode) != handle->nodeid)
690 if (inode->i_generation != handle->generation)
693 entry = d_obtain_alias(inode);
694 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
695 fuse_invalidate_entry_cache(entry);
705 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
706 struct inode *parent)
708 int len = parent ? 6 : 3;
712 if (*max_len < len) {
714 return FILEID_INVALID;
717 nodeid = get_fuse_inode(inode)->nodeid;
718 generation = inode->i_generation;
720 fh[0] = (u32)(nodeid >> 32);
721 fh[1] = (u32)(nodeid & 0xffffffff);
725 nodeid = get_fuse_inode(parent)->nodeid;
726 generation = parent->i_generation;
728 fh[3] = (u32)(nodeid >> 32);
729 fh[4] = (u32)(nodeid & 0xffffffff);
734 return parent ? 0x82 : 0x81;
737 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
738 struct fid *fid, int fh_len, int fh_type)
740 struct fuse_inode_handle handle;
742 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
745 handle.nodeid = (u64) fid->raw[0] << 32;
746 handle.nodeid |= (u64) fid->raw[1];
747 handle.generation = fid->raw[2];
748 return fuse_get_dentry(sb, &handle);
751 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
752 struct fid *fid, int fh_len, int fh_type)
754 struct fuse_inode_handle parent;
756 if (fh_type != 0x82 || fh_len < 6)
759 parent.nodeid = (u64) fid->raw[3] << 32;
760 parent.nodeid |= (u64) fid->raw[4];
761 parent.generation = fid->raw[5];
762 return fuse_get_dentry(sb, &parent);
765 static struct dentry *fuse_get_parent(struct dentry *child)
767 struct inode *child_inode = d_inode(child);
768 struct fuse_conn *fc = get_fuse_conn(child_inode);
770 struct dentry *parent;
771 struct fuse_entry_out outarg;
772 const struct qstr name = QSTR_INIT("..", 2);
775 if (!fc->export_support)
776 return ERR_PTR(-ESTALE);
778 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
779 &name, &outarg, &inode);
782 return ERR_PTR(-ESTALE);
786 parent = d_obtain_alias(inode);
787 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
788 fuse_invalidate_entry_cache(parent);
793 static const struct export_operations fuse_export_operations = {
794 .fh_to_dentry = fuse_fh_to_dentry,
795 .fh_to_parent = fuse_fh_to_parent,
796 .encode_fh = fuse_encode_fh,
797 .get_parent = fuse_get_parent,
800 static const struct super_operations fuse_super_operations = {
801 .alloc_inode = fuse_alloc_inode,
802 .destroy_inode = fuse_destroy_inode,
803 .evict_inode = fuse_evict_inode,
804 .write_inode = fuse_write_inode,
805 .drop_inode = generic_delete_inode,
806 .remount_fs = fuse_remount_fs,
807 .put_super = fuse_put_super,
808 .umount_begin = fuse_umount_begin,
809 .statfs = fuse_statfs,
810 .show_options = fuse_show_options,
813 static void sanitize_global_limit(unsigned *limit)
816 *limit = ((totalram_pages << PAGE_SHIFT) >> 13) /
817 sizeof(struct fuse_req);
819 if (*limit >= 1 << 16)
820 *limit = (1 << 16) - 1;
823 static int set_global_limit(const char *val, struct kernel_param *kp)
827 rv = param_set_uint(val, kp);
831 sanitize_global_limit((unsigned *)kp->arg);
836 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
838 int cap_sys_admin = capable(CAP_SYS_ADMIN);
843 sanitize_global_limit(&max_user_bgreq);
844 sanitize_global_limit(&max_user_congthresh);
846 if (arg->max_background) {
847 fc->max_background = arg->max_background;
849 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
850 fc->max_background = max_user_bgreq;
852 if (arg->congestion_threshold) {
853 fc->congestion_threshold = arg->congestion_threshold;
855 if (!cap_sys_admin &&
856 fc->congestion_threshold > max_user_congthresh)
857 fc->congestion_threshold = max_user_congthresh;
861 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
863 struct fuse_init_out *arg = &req->misc.init_out;
865 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
868 unsigned long ra_pages;
870 process_init_limits(fc, arg);
872 if (arg->minor >= 6) {
873 ra_pages = arg->max_readahead / PAGE_SIZE;
874 if (arg->flags & FUSE_ASYNC_READ)
876 if (!(arg->flags & FUSE_POSIX_LOCKS))
878 if (arg->minor >= 17) {
879 if (!(arg->flags & FUSE_FLOCK_LOCKS))
882 if (!(arg->flags & FUSE_POSIX_LOCKS))
885 if (arg->flags & FUSE_ATOMIC_O_TRUNC)
886 fc->atomic_o_trunc = 1;
887 if (arg->minor >= 9) {
888 /* LOOKUP has dependency on proto version */
889 if (arg->flags & FUSE_EXPORT_SUPPORT)
890 fc->export_support = 1;
892 if (arg->flags & FUSE_BIG_WRITES)
894 if (arg->flags & FUSE_DONT_MASK)
896 if (arg->flags & FUSE_AUTO_INVAL_DATA)
897 fc->auto_inval_data = 1;
898 if (arg->flags & FUSE_DO_READDIRPLUS) {
899 fc->do_readdirplus = 1;
900 if (arg->flags & FUSE_READDIRPLUS_AUTO)
901 fc->readdirplus_auto = 1;
903 if (arg->flags & FUSE_ASYNC_DIO)
905 if (arg->flags & FUSE_WRITEBACK_CACHE)
906 fc->writeback_cache = 1;
907 if (arg->flags & FUSE_PARALLEL_DIROPS)
908 fc->parallel_dirops = 1;
909 if (arg->flags & FUSE_HANDLE_KILLPRIV)
910 fc->handle_killpriv = 1;
911 if (arg->time_gran && arg->time_gran <= 1000000000)
912 fc->sb->s_time_gran = arg->time_gran;
913 if ((arg->flags & FUSE_POSIX_ACL)) {
914 fc->default_permissions = 1;
916 fc->sb->s_xattr = fuse_acl_xattr_handlers;
919 ra_pages = fc->max_read / PAGE_SIZE;
924 fc->sb->s_bdi->ra_pages =
925 min(fc->sb->s_bdi->ra_pages, ra_pages);
926 fc->minor = arg->minor;
927 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
928 fc->max_write = max_t(unsigned, 4096, fc->max_write);
931 fuse_set_initialized(fc);
932 wake_up_all(&fc->blocked_waitq);
935 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
937 struct fuse_init_in *arg = &req->misc.init_in;
939 arg->major = FUSE_KERNEL_VERSION;
940 arg->minor = FUSE_KERNEL_MINOR_VERSION;
941 arg->max_readahead = fc->sb->s_bdi->ra_pages * PAGE_SIZE;
942 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
943 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
944 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
945 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
946 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
947 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT |
948 FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL;
949 req->in.h.opcode = FUSE_INIT;
951 req->in.args[0].size = sizeof(*arg);
952 req->in.args[0].value = arg;
953 req->out.numargs = 1;
954 /* Variable length argument used for backward compatibility
955 with interface version < 7.5. Rest of init_out is zeroed
956 by do_get_request(), so a short reply is not a problem */
958 req->out.args[0].size = sizeof(struct fuse_init_out);
959 req->out.args[0].value = &req->misc.init_out;
960 req->end = process_init_reply;
961 fuse_request_send_background(fc, req);
964 static void fuse_free_conn(struct fuse_conn *fc)
966 WARN_ON(!list_empty(&fc->devices));
970 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
977 err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev),
978 MINOR(fc->dev), suffix);
982 sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_SIZE;
983 /* fuse does it's own writeback accounting */
984 sb->s_bdi->capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
987 * For a single fuse filesystem use max 1% of dirty +
988 * writeback threshold.
990 * This gives about 1M of write buffer for memory maps on a
991 * machine with 1G and 10% dirty_ratio, which should be more
994 * Privileged users can raise it by writing to
996 * /sys/class/bdi/<bdi>/max_ratio
998 bdi_set_max_ratio(sb->s_bdi, 1);
1003 struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc)
1005 struct fuse_dev *fud;
1007 fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL);
1009 fud->fc = fuse_conn_get(fc);
1010 fuse_pqueue_init(&fud->pq);
1012 spin_lock(&fc->lock);
1013 list_add_tail(&fud->entry, &fc->devices);
1014 spin_unlock(&fc->lock);
1019 EXPORT_SYMBOL_GPL(fuse_dev_alloc);
1021 void fuse_dev_free(struct fuse_dev *fud)
1023 struct fuse_conn *fc = fud->fc;
1026 spin_lock(&fc->lock);
1027 list_del(&fud->entry);
1028 spin_unlock(&fc->lock);
1034 EXPORT_SYMBOL_GPL(fuse_dev_free);
1036 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
1038 struct fuse_dev *fud;
1039 struct fuse_conn *fc;
1041 struct fuse_mount_data d;
1043 struct dentry *root_dentry;
1044 struct fuse_req *init_req;
1046 int is_bdev = sb->s_bdev != NULL;
1049 if (sb->s_flags & MS_MANDLOCK)
1052 sb->s_flags &= ~(MS_NOSEC | MS_I_VERSION);
1054 if (!parse_fuse_opt(data, &d, is_bdev))
1060 if (!sb_set_blocksize(sb, d.blksize))
1064 sb->s_blocksize = PAGE_SIZE;
1065 sb->s_blocksize_bits = PAGE_SHIFT;
1067 sb->s_magic = FUSE_SUPER_MAGIC;
1068 sb->s_op = &fuse_super_operations;
1069 sb->s_xattr = fuse_xattr_handlers;
1070 sb->s_maxbytes = MAX_LFS_FILESIZE;
1071 sb->s_time_gran = 1;
1072 sb->s_export_op = &fuse_export_operations;
1079 if ((file->f_op != &fuse_dev_operations) ||
1080 (file->f_cred->user_ns != &init_user_ns))
1083 fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1089 fc->release = fuse_free_conn;
1091 fud = fuse_dev_alloc(fc);
1095 fc->dev = sb->s_dev;
1097 err = fuse_bdi_init(fc, sb);
1101 /* Handle umasking inside the fuse code */
1102 if (sb->s_flags & MS_POSIXACL)
1104 sb->s_flags |= MS_POSIXACL;
1106 fc->default_permissions = d.default_permissions;
1107 fc->allow_other = d.allow_other;
1108 fc->user_id = d.user_id;
1109 fc->group_id = d.group_id;
1110 fc->max_read = max_t(unsigned, 4096, d.max_read);
1112 /* Used by get_root_inode() */
1116 root = fuse_get_root_inode(sb, d.rootmode);
1117 sb->s_d_op = &fuse_root_dentry_operations;
1118 root_dentry = d_make_root(root);
1121 /* Root dentry doesn't have .d_revalidate */
1122 sb->s_d_op = &fuse_dentry_operations;
1124 init_req = fuse_request_alloc(0);
1127 __set_bit(FR_BACKGROUND, &init_req->flags);
1130 fc->destroy_req = fuse_request_alloc(0);
1131 if (!fc->destroy_req)
1132 goto err_free_init_req;
1135 mutex_lock(&fuse_mutex);
1137 if (file->private_data)
1140 err = fuse_ctl_add_conn(fc);
1144 list_add_tail(&fc->entry, &fuse_conn_list);
1145 sb->s_root = root_dentry;
1146 file->private_data = fud;
1147 mutex_unlock(&fuse_mutex);
1149 * atomic_dec_and_test() in fput() provides the necessary
1150 * memory barrier for file->private_data to be visible on all
1155 fuse_send_init(fc, init_req);
1160 mutex_unlock(&fuse_mutex);
1162 fuse_request_free(init_req);
1175 static struct dentry *fuse_mount(struct file_system_type *fs_type,
1176 int flags, const char *dev_name,
1179 return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1182 static void fuse_kill_sb_anon(struct super_block *sb)
1184 struct fuse_conn *fc = get_fuse_conn_super(sb);
1187 down_write(&fc->killsb);
1189 up_write(&fc->killsb);
1192 kill_anon_super(sb);
1195 static struct file_system_type fuse_fs_type = {
1196 .owner = THIS_MODULE,
1198 .fs_flags = FS_HAS_SUBTYPE,
1199 .mount = fuse_mount,
1200 .kill_sb = fuse_kill_sb_anon,
1202 MODULE_ALIAS_FS("fuse");
1205 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1206 int flags, const char *dev_name,
1209 return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1212 static void fuse_kill_sb_blk(struct super_block *sb)
1214 struct fuse_conn *fc = get_fuse_conn_super(sb);
1217 down_write(&fc->killsb);
1219 up_write(&fc->killsb);
1222 kill_block_super(sb);
1225 static struct file_system_type fuseblk_fs_type = {
1226 .owner = THIS_MODULE,
1228 .mount = fuse_mount_blk,
1229 .kill_sb = fuse_kill_sb_blk,
1230 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1232 MODULE_ALIAS_FS("fuseblk");
1234 static inline int register_fuseblk(void)
1236 return register_filesystem(&fuseblk_fs_type);
1239 static inline void unregister_fuseblk(void)
1241 unregister_filesystem(&fuseblk_fs_type);
1244 static inline int register_fuseblk(void)
1249 static inline void unregister_fuseblk(void)
1254 static void fuse_inode_init_once(void *foo)
1256 struct inode *inode = foo;
1258 inode_init_once(inode);
1261 static int __init fuse_fs_init(void)
1265 fuse_inode_cachep = kmem_cache_create("fuse_inode",
1266 sizeof(struct fuse_inode), 0,
1267 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT,
1268 fuse_inode_init_once);
1270 if (!fuse_inode_cachep)
1273 err = register_fuseblk();
1277 err = register_filesystem(&fuse_fs_type);
1284 unregister_fuseblk();
1286 kmem_cache_destroy(fuse_inode_cachep);
1291 static void fuse_fs_cleanup(void)
1293 unregister_filesystem(&fuse_fs_type);
1294 unregister_fuseblk();
1297 * Make sure all delayed rcu free inodes are flushed before we
1301 kmem_cache_destroy(fuse_inode_cachep);
1304 static struct kobject *fuse_kobj;
1306 static int fuse_sysfs_init(void)
1310 fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1316 err = sysfs_create_mount_point(fuse_kobj, "connections");
1318 goto out_fuse_unregister;
1322 out_fuse_unregister:
1323 kobject_put(fuse_kobj);
1328 static void fuse_sysfs_cleanup(void)
1330 sysfs_remove_mount_point(fuse_kobj, "connections");
1331 kobject_put(fuse_kobj);
1334 static int __init fuse_init(void)
1338 printk(KERN_INFO "fuse init (API version %i.%i)\n",
1339 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1341 INIT_LIST_HEAD(&fuse_conn_list);
1342 res = fuse_fs_init();
1346 res = fuse_dev_init();
1348 goto err_fs_cleanup;
1350 res = fuse_sysfs_init();
1352 goto err_dev_cleanup;
1354 res = fuse_ctl_init();
1356 goto err_sysfs_cleanup;
1358 sanitize_global_limit(&max_user_bgreq);
1359 sanitize_global_limit(&max_user_congthresh);
1364 fuse_sysfs_cleanup();
1373 static void __exit fuse_exit(void)
1375 printk(KERN_DEBUG "fuse exit\n");
1378 fuse_sysfs_cleanup();
1383 module_init(fuse_init);
1384 module_exit(fuse_exit);