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/fs_context.h>
19 #include <linux/fs_parser.h>
20 #include <linux/statfs.h>
21 #include <linux/random.h>
22 #include <linux/sched.h>
23 #include <linux/exportfs.h>
24 #include <linux/posix_acl.h>
25 #include <linux/pid_namespace.h>
27 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
28 MODULE_DESCRIPTION("Filesystem in Userspace");
29 MODULE_LICENSE("GPL");
31 static struct kmem_cache *fuse_inode_cachep;
32 struct list_head fuse_conn_list;
33 DEFINE_MUTEX(fuse_mutex);
35 static int set_global_limit(const char *val, const struct kernel_param *kp);
37 unsigned max_user_bgreq;
38 module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
39 &max_user_bgreq, 0644);
40 __MODULE_PARM_TYPE(max_user_bgreq, "uint");
41 MODULE_PARM_DESC(max_user_bgreq,
42 "Global limit for the maximum number of backgrounded requests an "
43 "unprivileged user can set");
45 unsigned max_user_congthresh;
46 module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
47 &max_user_congthresh, 0644);
48 __MODULE_PARM_TYPE(max_user_congthresh, "uint");
49 MODULE_PARM_DESC(max_user_congthresh,
50 "Global limit for the maximum congestion threshold an "
51 "unprivileged user can set");
53 #define FUSE_SUPER_MAGIC 0x65735546
55 #define FUSE_DEFAULT_BLKSIZE 512
57 /** Maximum number of outstanding background requests */
58 #define FUSE_DEFAULT_MAX_BACKGROUND 12
60 /** Congestion starts at 75% of maximum */
61 #define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
64 static struct file_system_type fuseblk_fs_type;
67 struct fuse_forget_link *fuse_alloc_forget(void)
69 return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL_ACCOUNT);
72 static struct inode *fuse_alloc_inode(struct super_block *sb)
74 struct fuse_inode *fi;
76 fi = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
87 mutex_init(&fi->mutex);
88 spin_lock_init(&fi->lock);
89 fi->forget = fuse_alloc_forget();
93 if (IS_ENABLED(CONFIG_FUSE_DAX) && !fuse_dax_inode_alloc(sb, fi))
101 kmem_cache_free(fuse_inode_cachep, fi);
105 static void fuse_free_inode(struct inode *inode)
107 struct fuse_inode *fi = get_fuse_inode(inode);
109 mutex_destroy(&fi->mutex);
111 #ifdef CONFIG_FUSE_DAX
114 kmem_cache_free(fuse_inode_cachep, fi);
117 static void fuse_evict_inode(struct inode *inode)
119 struct fuse_inode *fi = get_fuse_inode(inode);
121 truncate_inode_pages_final(&inode->i_data);
123 if (inode->i_sb->s_flags & SB_ACTIVE) {
124 struct fuse_conn *fc = get_fuse_conn(inode);
126 if (FUSE_IS_DAX(inode))
127 fuse_dax_inode_cleanup(inode);
129 fuse_queue_forget(fc, fi->forget, fi->nodeid,
134 if (S_ISREG(inode->i_mode) && !fuse_is_bad(inode)) {
135 WARN_ON(!list_empty(&fi->write_files));
136 WARN_ON(!list_empty(&fi->queued_writes));
140 static int fuse_reconfigure(struct fs_context *fsc)
142 struct super_block *sb = fsc->root->d_sb;
145 if (fsc->sb_flags & SB_MANDLOCK)
152 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
153 * so that it will fit.
155 static ino_t fuse_squash_ino(u64 ino64)
157 ino_t ino = (ino_t) ino64;
158 if (sizeof(ino_t) < sizeof(u64))
159 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
163 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
166 struct fuse_conn *fc = get_fuse_conn(inode);
167 struct fuse_inode *fi = get_fuse_inode(inode);
169 lockdep_assert_held(&fi->lock);
171 fi->attr_version = atomic64_inc_return(&fc->attr_version);
172 fi->i_time = attr_valid;
173 WRITE_ONCE(fi->inval_mask, 0);
175 inode->i_ino = fuse_squash_ino(attr->ino);
176 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
177 set_nlink(inode, attr->nlink);
178 inode->i_uid = make_kuid(fc->user_ns, attr->uid);
179 inode->i_gid = make_kgid(fc->user_ns, attr->gid);
180 inode->i_blocks = attr->blocks;
181 inode->i_atime.tv_sec = attr->atime;
182 inode->i_atime.tv_nsec = attr->atimensec;
183 /* mtime from server may be stale due to local buffered write */
184 if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) {
185 inode->i_mtime.tv_sec = attr->mtime;
186 inode->i_mtime.tv_nsec = attr->mtimensec;
187 inode->i_ctime.tv_sec = attr->ctime;
188 inode->i_ctime.tv_nsec = attr->ctimensec;
191 if (attr->blksize != 0)
192 inode->i_blkbits = ilog2(attr->blksize);
194 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
197 * Don't set the sticky bit in i_mode, unless we want the VFS
198 * to check permissions. This prevents failures due to the
199 * check in may_delete().
201 fi->orig_i_mode = inode->i_mode;
202 if (!fc->default_permissions)
203 inode->i_mode &= ~S_ISVTX;
205 fi->orig_ino = attr->ino;
208 * We are refreshing inode data and it is possible that another
209 * client set suid/sgid or security.capability xattr. So clear
210 * S_NOSEC. Ideally, we could have cleared it only if suid/sgid
211 * was set or if security.capability xattr was set. But we don't
212 * know if security.capability has been set or not. So clear it
213 * anyway. Its less efficient but should be safe.
215 inode->i_flags &= ~S_NOSEC;
218 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
219 u64 attr_valid, u64 attr_version)
221 struct fuse_conn *fc = get_fuse_conn(inode);
222 struct fuse_inode *fi = get_fuse_inode(inode);
223 bool is_wb = fc->writeback_cache;
225 struct timespec64 old_mtime;
227 spin_lock(&fi->lock);
228 if ((attr_version != 0 && fi->attr_version > attr_version) ||
229 test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
230 spin_unlock(&fi->lock);
234 old_mtime = inode->i_mtime;
235 fuse_change_attributes_common(inode, attr, attr_valid);
237 oldsize = inode->i_size;
239 * In case of writeback_cache enabled, the cached writes beyond EOF
240 * extend local i_size without keeping userspace server in sync. So,
241 * attr->size coming from server can be stale. We cannot trust it.
243 if (!is_wb || !S_ISREG(inode->i_mode))
244 i_size_write(inode, attr->size);
245 spin_unlock(&fi->lock);
247 if (!is_wb && S_ISREG(inode->i_mode)) {
250 if (oldsize != attr->size) {
251 truncate_pagecache(inode, attr->size);
252 if (!fc->explicit_inval_data)
254 } else if (fc->auto_inval_data) {
255 struct timespec64 new_mtime = {
256 .tv_sec = attr->mtime,
257 .tv_nsec = attr->mtimensec,
261 * Auto inval mode also checks and invalidates if mtime
264 if (!timespec64_equal(&old_mtime, &new_mtime))
269 invalidate_inode_pages2(inode->i_mapping);
273 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
275 inode->i_mode = attr->mode & S_IFMT;
276 inode->i_size = attr->size;
277 inode->i_mtime.tv_sec = attr->mtime;
278 inode->i_mtime.tv_nsec = attr->mtimensec;
279 inode->i_ctime.tv_sec = attr->ctime;
280 inode->i_ctime.tv_nsec = attr->ctimensec;
281 if (S_ISREG(inode->i_mode)) {
282 fuse_init_common(inode);
283 fuse_init_file_inode(inode);
284 } else if (S_ISDIR(inode->i_mode))
285 fuse_init_dir(inode);
286 else if (S_ISLNK(inode->i_mode))
287 fuse_init_symlink(inode);
288 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
289 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
290 fuse_init_common(inode);
291 init_special_inode(inode, inode->i_mode,
292 new_decode_dev(attr->rdev));
297 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
299 u64 nodeid = *(u64 *) _nodeidp;
300 if (get_node_id(inode) == nodeid)
306 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
308 u64 nodeid = *(u64 *) _nodeidp;
309 get_fuse_inode(inode)->nodeid = nodeid;
313 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
314 int generation, struct fuse_attr *attr,
315 u64 attr_valid, u64 attr_version)
318 struct fuse_inode *fi;
319 struct fuse_conn *fc = get_fuse_conn_super(sb);
322 * Auto mount points get their node id from the submount root, which is
323 * not a unique identifier within this filesystem.
325 * To avoid conflicts, do not place submount points into the inode hash
328 if (fc->auto_submounts && (attr->flags & FUSE_ATTR_SUBMOUNT) &&
329 S_ISDIR(attr->mode)) {
330 inode = new_inode(sb);
334 fuse_init_inode(inode, attr);
335 get_fuse_inode(inode)->nodeid = nodeid;
336 inode->i_flags |= S_AUTOMOUNT;
341 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
345 if ((inode->i_state & I_NEW)) {
346 inode->i_flags |= S_NOATIME;
347 if (!fc->writeback_cache || !S_ISREG(attr->mode))
348 inode->i_flags |= S_NOCMTIME;
349 inode->i_generation = generation;
350 fuse_init_inode(inode, attr);
351 unlock_new_inode(inode);
352 } else if (fuse_stale_inode(inode, generation, attr)) {
353 /* nodeid was reused, any I/O on the old inode should fail */
354 fuse_make_bad(inode);
359 fi = get_fuse_inode(inode);
360 spin_lock(&fi->lock);
362 spin_unlock(&fi->lock);
363 fuse_change_attributes(inode, attr, attr_valid, attr_version);
368 struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid,
369 struct fuse_mount **fm)
371 struct fuse_mount *fm_iter;
374 WARN_ON(!rwsem_is_locked(&fc->killsb));
375 list_for_each_entry(fm_iter, &fc->mounts, fc_entry) {
379 inode = ilookup5(fm_iter->sb, nodeid, fuse_inode_eq, &nodeid);
390 int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
391 loff_t offset, loff_t len)
393 struct fuse_inode *fi;
398 inode = fuse_ilookup(fc, nodeid, NULL);
402 fi = get_fuse_inode(inode);
403 spin_lock(&fi->lock);
404 fi->attr_version = atomic64_inc_return(&fc->attr_version);
405 spin_unlock(&fi->lock);
407 fuse_invalidate_attr(inode);
408 forget_all_cached_acls(inode);
410 pg_start = offset >> PAGE_SHIFT;
414 pg_end = (offset + len - 1) >> PAGE_SHIFT;
415 invalidate_inode_pages2_range(inode->i_mapping,
422 bool fuse_lock_inode(struct inode *inode)
426 if (!get_fuse_conn(inode)->parallel_dirops) {
427 mutex_lock(&get_fuse_inode(inode)->mutex);
434 void fuse_unlock_inode(struct inode *inode, bool locked)
437 mutex_unlock(&get_fuse_inode(inode)->mutex);
440 static void fuse_umount_begin(struct super_block *sb)
442 struct fuse_conn *fc = get_fuse_conn_super(sb);
444 if (!fc->no_force_umount)
448 static void fuse_send_destroy(struct fuse_mount *fm)
450 if (fm->fc->conn_init) {
453 args.opcode = FUSE_DESTROY;
456 fuse_simple_request(fm, &args);
460 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
462 stbuf->f_type = FUSE_SUPER_MAGIC;
463 stbuf->f_bsize = attr->bsize;
464 stbuf->f_frsize = attr->frsize;
465 stbuf->f_blocks = attr->blocks;
466 stbuf->f_bfree = attr->bfree;
467 stbuf->f_bavail = attr->bavail;
468 stbuf->f_files = attr->files;
469 stbuf->f_ffree = attr->ffree;
470 stbuf->f_namelen = attr->namelen;
471 /* fsid is left zero */
474 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
476 struct super_block *sb = dentry->d_sb;
477 struct fuse_mount *fm = get_fuse_mount_super(sb);
479 struct fuse_statfs_out outarg;
482 if (!fuse_allow_current_process(fm->fc)) {
483 buf->f_type = FUSE_SUPER_MAGIC;
487 memset(&outarg, 0, sizeof(outarg));
489 args.opcode = FUSE_STATFS;
490 args.nodeid = get_node_id(d_inode(dentry));
491 args.out_numargs = 1;
492 args.out_args[0].size = sizeof(outarg);
493 args.out_args[0].value = &outarg;
494 err = fuse_simple_request(fm, &args);
496 convert_fuse_statfs(buf, &outarg.st);
500 static struct fuse_sync_bucket *fuse_sync_bucket_alloc(void)
502 struct fuse_sync_bucket *bucket;
504 bucket = kzalloc(sizeof(*bucket), GFP_KERNEL | __GFP_NOFAIL);
506 init_waitqueue_head(&bucket->waitq);
507 /* Initial active count */
508 atomic_set(&bucket->count, 1);
513 static void fuse_sync_fs_writes(struct fuse_conn *fc)
515 struct fuse_sync_bucket *bucket, *new_bucket;
518 new_bucket = fuse_sync_bucket_alloc();
519 spin_lock(&fc->lock);
520 bucket = rcu_dereference_protected(fc->curr_bucket, 1);
521 count = atomic_read(&bucket->count);
523 /* No outstanding writes? */
525 spin_unlock(&fc->lock);
531 * Completion of new bucket depends on completion of this bucket, so add
534 atomic_inc(&new_bucket->count);
535 rcu_assign_pointer(fc->curr_bucket, new_bucket);
536 spin_unlock(&fc->lock);
538 * Drop initial active count. At this point if all writes in this and
539 * ancestor buckets complete, the count will go to zero and this task
542 atomic_dec(&bucket->count);
544 wait_event(bucket->waitq, atomic_read(&bucket->count) == 0);
546 /* Drop temp count on descendant bucket */
547 fuse_sync_bucket_dec(new_bucket);
548 kfree_rcu(bucket, rcu);
551 static int fuse_sync_fs(struct super_block *sb, int wait)
553 struct fuse_mount *fm = get_fuse_mount_super(sb);
554 struct fuse_conn *fc = fm->fc;
555 struct fuse_syncfs_in inarg;
560 * Userspace cannot handle the wait == 0 case. Avoid a
561 * gratuitous roundtrip.
566 /* The filesystem is being unmounted. Nothing to do. */
573 fuse_sync_fs_writes(fc);
575 memset(&inarg, 0, sizeof(inarg));
577 args.in_args[0].size = sizeof(inarg);
578 args.in_args[0].value = &inarg;
579 args.opcode = FUSE_SYNCFS;
580 args.nodeid = get_node_id(sb->s_root->d_inode);
581 args.out_numargs = 0;
583 err = fuse_simple_request(fm, &args);
584 if (err == -ENOSYS) {
599 OPT_DEFAULT_PERMISSIONS,
606 static const struct fs_parameter_spec fuse_fs_parameters[] = {
607 fsparam_string ("source", OPT_SOURCE),
608 fsparam_u32 ("fd", OPT_FD),
609 fsparam_u32oct ("rootmode", OPT_ROOTMODE),
610 fsparam_u32 ("user_id", OPT_USER_ID),
611 fsparam_u32 ("group_id", OPT_GROUP_ID),
612 fsparam_flag ("default_permissions", OPT_DEFAULT_PERMISSIONS),
613 fsparam_flag ("allow_other", OPT_ALLOW_OTHER),
614 fsparam_u32 ("max_read", OPT_MAX_READ),
615 fsparam_u32 ("blksize", OPT_BLKSIZE),
616 fsparam_string ("subtype", OPT_SUBTYPE),
620 static int fuse_parse_param(struct fs_context *fsc, struct fs_parameter *param)
622 struct fs_parse_result result;
623 struct fuse_fs_context *ctx = fsc->fs_private;
626 if (fsc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
628 * Ignore options coming from mount(MS_REMOUNT) for backward
634 return invalfc(fsc, "No changes allowed in reconfigure");
637 opt = fs_parse(fsc, fuse_fs_parameters, param, &result);
644 return invalfc(fsc, "Multiple sources specified");
645 fsc->source = param->string;
646 param->string = NULL;
651 return invalfc(fsc, "Multiple subtypes specified");
652 ctx->subtype = param->string;
653 param->string = NULL;
657 ctx->fd = result.uint_32;
658 ctx->fd_present = true;
662 if (!fuse_valid_type(result.uint_32))
663 return invalfc(fsc, "Invalid rootmode");
664 ctx->rootmode = result.uint_32;
665 ctx->rootmode_present = true;
669 ctx->user_id = make_kuid(fsc->user_ns, result.uint_32);
670 if (!uid_valid(ctx->user_id))
671 return invalfc(fsc, "Invalid user_id");
672 ctx->user_id_present = true;
676 ctx->group_id = make_kgid(fsc->user_ns, result.uint_32);
677 if (!gid_valid(ctx->group_id))
678 return invalfc(fsc, "Invalid group_id");
679 ctx->group_id_present = true;
682 case OPT_DEFAULT_PERMISSIONS:
683 ctx->default_permissions = true;
686 case OPT_ALLOW_OTHER:
687 ctx->allow_other = true;
691 ctx->max_read = result.uint_32;
696 return invalfc(fsc, "blksize only supported for fuseblk");
697 ctx->blksize = result.uint_32;
707 static void fuse_free_fsc(struct fs_context *fsc)
709 struct fuse_fs_context *ctx = fsc->fs_private;
717 static int fuse_show_options(struct seq_file *m, struct dentry *root)
719 struct super_block *sb = root->d_sb;
720 struct fuse_conn *fc = get_fuse_conn_super(sb);
722 if (fc->legacy_opts_show) {
723 seq_printf(m, ",user_id=%u",
724 from_kuid_munged(fc->user_ns, fc->user_id));
725 seq_printf(m, ",group_id=%u",
726 from_kgid_munged(fc->user_ns, fc->group_id));
727 if (fc->default_permissions)
728 seq_puts(m, ",default_permissions");
730 seq_puts(m, ",allow_other");
731 if (fc->max_read != ~0)
732 seq_printf(m, ",max_read=%u", fc->max_read);
733 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
734 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
736 #ifdef CONFIG_FUSE_DAX
744 static void fuse_iqueue_init(struct fuse_iqueue *fiq,
745 const struct fuse_iqueue_ops *ops,
748 memset(fiq, 0, sizeof(struct fuse_iqueue));
749 spin_lock_init(&fiq->lock);
750 init_waitqueue_head(&fiq->waitq);
751 INIT_LIST_HEAD(&fiq->pending);
752 INIT_LIST_HEAD(&fiq->interrupts);
753 fiq->forget_list_tail = &fiq->forget_list_head;
759 static void fuse_pqueue_init(struct fuse_pqueue *fpq)
763 spin_lock_init(&fpq->lock);
764 for (i = 0; i < FUSE_PQ_HASH_SIZE; i++)
765 INIT_LIST_HEAD(&fpq->processing[i]);
766 INIT_LIST_HEAD(&fpq->io);
770 void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
771 struct user_namespace *user_ns,
772 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv)
774 memset(fc, 0, sizeof(*fc));
775 spin_lock_init(&fc->lock);
776 spin_lock_init(&fc->bg_lock);
777 init_rwsem(&fc->killsb);
778 refcount_set(&fc->count, 1);
779 atomic_set(&fc->dev_count, 1);
780 init_waitqueue_head(&fc->blocked_waitq);
781 fuse_iqueue_init(&fc->iq, fiq_ops, fiq_priv);
782 INIT_LIST_HEAD(&fc->bg_queue);
783 INIT_LIST_HEAD(&fc->entry);
784 INIT_LIST_HEAD(&fc->devices);
785 atomic_set(&fc->num_waiting, 0);
786 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
787 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
788 atomic64_set(&fc->khctr, 0);
789 fc->polled_files = RB_ROOT;
793 atomic64_set(&fc->attr_version, 1);
794 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
795 fc->pid_ns = get_pid_ns(task_active_pid_ns(current));
796 fc->user_ns = get_user_ns(user_ns);
797 fc->max_pages = FUSE_DEFAULT_MAX_PAGES_PER_REQ;
798 fc->max_pages_limit = FUSE_MAX_MAX_PAGES;
800 INIT_LIST_HEAD(&fc->mounts);
801 list_add(&fm->fc_entry, &fc->mounts);
804 EXPORT_SYMBOL_GPL(fuse_conn_init);
806 void fuse_conn_put(struct fuse_conn *fc)
808 if (refcount_dec_and_test(&fc->count)) {
809 struct fuse_iqueue *fiq = &fc->iq;
810 struct fuse_sync_bucket *bucket;
812 if (IS_ENABLED(CONFIG_FUSE_DAX))
813 fuse_dax_conn_free(fc);
814 if (fiq->ops->release)
815 fiq->ops->release(fiq);
816 put_pid_ns(fc->pid_ns);
817 put_user_ns(fc->user_ns);
818 bucket = rcu_dereference_protected(fc->curr_bucket, 1);
820 WARN_ON(atomic_read(&bucket->count) != 1);
826 EXPORT_SYMBOL_GPL(fuse_conn_put);
828 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
830 refcount_inc(&fc->count);
833 EXPORT_SYMBOL_GPL(fuse_conn_get);
835 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
837 struct fuse_attr attr;
838 memset(&attr, 0, sizeof(attr));
841 attr.ino = FUSE_ROOT_ID;
843 return fuse_iget(sb, 1, 0, &attr, 0, 0);
846 struct fuse_inode_handle {
851 static struct dentry *fuse_get_dentry(struct super_block *sb,
852 struct fuse_inode_handle *handle)
854 struct fuse_conn *fc = get_fuse_conn_super(sb);
856 struct dentry *entry;
859 if (handle->nodeid == 0)
862 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
864 struct fuse_entry_out outarg;
865 const struct qstr name = QSTR_INIT(".", 1);
867 if (!fc->export_support)
870 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
872 if (err && err != -ENOENT)
879 if (get_node_id(inode) != handle->nodeid)
883 if (inode->i_generation != handle->generation)
886 entry = d_obtain_alias(inode);
887 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
888 fuse_invalidate_entry_cache(entry);
898 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
899 struct inode *parent)
901 int len = parent ? 6 : 3;
905 if (*max_len < len) {
907 return FILEID_INVALID;
910 nodeid = get_fuse_inode(inode)->nodeid;
911 generation = inode->i_generation;
913 fh[0] = (u32)(nodeid >> 32);
914 fh[1] = (u32)(nodeid & 0xffffffff);
918 nodeid = get_fuse_inode(parent)->nodeid;
919 generation = parent->i_generation;
921 fh[3] = (u32)(nodeid >> 32);
922 fh[4] = (u32)(nodeid & 0xffffffff);
927 return parent ? 0x82 : 0x81;
930 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
931 struct fid *fid, int fh_len, int fh_type)
933 struct fuse_inode_handle handle;
935 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
938 handle.nodeid = (u64) fid->raw[0] << 32;
939 handle.nodeid |= (u64) fid->raw[1];
940 handle.generation = fid->raw[2];
941 return fuse_get_dentry(sb, &handle);
944 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
945 struct fid *fid, int fh_len, int fh_type)
947 struct fuse_inode_handle parent;
949 if (fh_type != 0x82 || fh_len < 6)
952 parent.nodeid = (u64) fid->raw[3] << 32;
953 parent.nodeid |= (u64) fid->raw[4];
954 parent.generation = fid->raw[5];
955 return fuse_get_dentry(sb, &parent);
958 static struct dentry *fuse_get_parent(struct dentry *child)
960 struct inode *child_inode = d_inode(child);
961 struct fuse_conn *fc = get_fuse_conn(child_inode);
963 struct dentry *parent;
964 struct fuse_entry_out outarg;
967 if (!fc->export_support)
968 return ERR_PTR(-ESTALE);
970 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
971 &dotdot_name, &outarg, &inode);
974 return ERR_PTR(-ESTALE);
978 parent = d_obtain_alias(inode);
979 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
980 fuse_invalidate_entry_cache(parent);
985 static const struct export_operations fuse_export_operations = {
986 .fh_to_dentry = fuse_fh_to_dentry,
987 .fh_to_parent = fuse_fh_to_parent,
988 .encode_fh = fuse_encode_fh,
989 .get_parent = fuse_get_parent,
992 static const struct super_operations fuse_super_operations = {
993 .alloc_inode = fuse_alloc_inode,
994 .free_inode = fuse_free_inode,
995 .evict_inode = fuse_evict_inode,
996 .write_inode = fuse_write_inode,
997 .drop_inode = generic_delete_inode,
998 .umount_begin = fuse_umount_begin,
999 .statfs = fuse_statfs,
1000 .sync_fs = fuse_sync_fs,
1001 .show_options = fuse_show_options,
1004 static void sanitize_global_limit(unsigned *limit)
1007 * The default maximum number of async requests is calculated to consume
1008 * 1/2^13 of the total memory, assuming 392 bytes per request.
1011 *limit = ((totalram_pages() << PAGE_SHIFT) >> 13) / 392;
1013 if (*limit >= 1 << 16)
1014 *limit = (1 << 16) - 1;
1017 static int set_global_limit(const char *val, const struct kernel_param *kp)
1021 rv = param_set_uint(val, kp);
1025 sanitize_global_limit((unsigned *)kp->arg);
1030 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
1032 int cap_sys_admin = capable(CAP_SYS_ADMIN);
1034 if (arg->minor < 13)
1037 sanitize_global_limit(&max_user_bgreq);
1038 sanitize_global_limit(&max_user_congthresh);
1040 spin_lock(&fc->bg_lock);
1041 if (arg->max_background) {
1042 fc->max_background = arg->max_background;
1044 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
1045 fc->max_background = max_user_bgreq;
1047 if (arg->congestion_threshold) {
1048 fc->congestion_threshold = arg->congestion_threshold;
1050 if (!cap_sys_admin &&
1051 fc->congestion_threshold > max_user_congthresh)
1052 fc->congestion_threshold = max_user_congthresh;
1054 spin_unlock(&fc->bg_lock);
1057 struct fuse_init_args {
1058 struct fuse_args args;
1059 struct fuse_init_in in;
1060 struct fuse_init_out out;
1063 static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args,
1066 struct fuse_conn *fc = fm->fc;
1067 struct fuse_init_args *ia = container_of(args, typeof(*ia), args);
1068 struct fuse_init_out *arg = &ia->out;
1071 if (error || arg->major != FUSE_KERNEL_VERSION)
1074 unsigned long ra_pages;
1076 process_init_limits(fc, arg);
1078 if (arg->minor >= 6) {
1079 ra_pages = arg->max_readahead / PAGE_SIZE;
1080 if (arg->flags & FUSE_ASYNC_READ)
1082 if (!(arg->flags & FUSE_POSIX_LOCKS))
1084 if (arg->minor >= 17) {
1085 if (!(arg->flags & FUSE_FLOCK_LOCKS))
1088 if (!(arg->flags & FUSE_POSIX_LOCKS))
1091 if (arg->flags & FUSE_ATOMIC_O_TRUNC)
1092 fc->atomic_o_trunc = 1;
1093 if (arg->minor >= 9) {
1094 /* LOOKUP has dependency on proto version */
1095 if (arg->flags & FUSE_EXPORT_SUPPORT)
1096 fc->export_support = 1;
1098 if (arg->flags & FUSE_BIG_WRITES)
1100 if (arg->flags & FUSE_DONT_MASK)
1102 if (arg->flags & FUSE_AUTO_INVAL_DATA)
1103 fc->auto_inval_data = 1;
1104 else if (arg->flags & FUSE_EXPLICIT_INVAL_DATA)
1105 fc->explicit_inval_data = 1;
1106 if (arg->flags & FUSE_DO_READDIRPLUS) {
1107 fc->do_readdirplus = 1;
1108 if (arg->flags & FUSE_READDIRPLUS_AUTO)
1109 fc->readdirplus_auto = 1;
1111 if (arg->flags & FUSE_ASYNC_DIO)
1113 if (arg->flags & FUSE_WRITEBACK_CACHE)
1114 fc->writeback_cache = 1;
1115 if (arg->flags & FUSE_PARALLEL_DIROPS)
1116 fc->parallel_dirops = 1;
1117 if (arg->flags & FUSE_HANDLE_KILLPRIV)
1118 fc->handle_killpriv = 1;
1119 if (arg->time_gran && arg->time_gran <= 1000000000)
1120 fm->sb->s_time_gran = arg->time_gran;
1121 if ((arg->flags & FUSE_POSIX_ACL)) {
1122 fc->default_permissions = 1;
1124 fm->sb->s_xattr = fuse_acl_xattr_handlers;
1126 if (arg->flags & FUSE_CACHE_SYMLINKS)
1127 fc->cache_symlinks = 1;
1128 if (arg->flags & FUSE_ABORT_ERROR)
1130 if (arg->flags & FUSE_MAX_PAGES) {
1132 min_t(unsigned int, fc->max_pages_limit,
1133 max_t(unsigned int, arg->max_pages, 1));
1135 if (IS_ENABLED(CONFIG_FUSE_DAX) &&
1136 arg->flags & FUSE_MAP_ALIGNMENT &&
1137 !fuse_dax_check_alignment(fc, arg->map_alignment)) {
1140 if (arg->flags & FUSE_HANDLE_KILLPRIV_V2) {
1141 fc->handle_killpriv_v2 = 1;
1142 fm->sb->s_flags |= SB_NOSEC;
1144 if (arg->flags & FUSE_SETXATTR_EXT)
1145 fc->setxattr_ext = 1;
1147 ra_pages = fc->max_read / PAGE_SIZE;
1152 fm->sb->s_bdi->ra_pages =
1153 min(fm->sb->s_bdi->ra_pages, ra_pages);
1154 fc->minor = arg->minor;
1155 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
1156 fc->max_write = max_t(unsigned, 4096, fc->max_write);
1166 fuse_set_initialized(fc);
1167 wake_up_all(&fc->blocked_waitq);
1170 void fuse_send_init(struct fuse_mount *fm)
1172 struct fuse_init_args *ia;
1174 ia = kzalloc(sizeof(*ia), GFP_KERNEL | __GFP_NOFAIL);
1176 ia->in.major = FUSE_KERNEL_VERSION;
1177 ia->in.minor = FUSE_KERNEL_MINOR_VERSION;
1178 ia->in.max_readahead = fm->sb->s_bdi->ra_pages * PAGE_SIZE;
1180 FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
1181 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
1182 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
1183 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
1184 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
1185 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT |
1186 FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL |
1187 FUSE_ABORT_ERROR | FUSE_MAX_PAGES | FUSE_CACHE_SYMLINKS |
1188 FUSE_NO_OPENDIR_SUPPORT | FUSE_EXPLICIT_INVAL_DATA |
1189 FUSE_HANDLE_KILLPRIV_V2 | FUSE_SETXATTR_EXT;
1190 #ifdef CONFIG_FUSE_DAX
1192 ia->in.flags |= FUSE_MAP_ALIGNMENT;
1194 if (fm->fc->auto_submounts)
1195 ia->in.flags |= FUSE_SUBMOUNTS;
1197 ia->args.opcode = FUSE_INIT;
1198 ia->args.in_numargs = 1;
1199 ia->args.in_args[0].size = sizeof(ia->in);
1200 ia->args.in_args[0].value = &ia->in;
1201 ia->args.out_numargs = 1;
1202 /* Variable length argument used for backward compatibility
1203 with interface version < 7.5. Rest of init_out is zeroed
1204 by do_get_request(), so a short reply is not a problem */
1205 ia->args.out_argvar = true;
1206 ia->args.out_args[0].size = sizeof(ia->out);
1207 ia->args.out_args[0].value = &ia->out;
1208 ia->args.force = true;
1209 ia->args.nocreds = true;
1210 ia->args.end = process_init_reply;
1212 if (fuse_simple_background(fm, &ia->args, GFP_KERNEL) != 0)
1213 process_init_reply(fm, &ia->args, -ENOTCONN);
1215 EXPORT_SYMBOL_GPL(fuse_send_init);
1217 void fuse_free_conn(struct fuse_conn *fc)
1219 WARN_ON(!list_empty(&fc->devices));
1222 EXPORT_SYMBOL_GPL(fuse_free_conn);
1224 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
1230 suffix = "-fuseblk";
1232 * sb->s_bdi points to blkdev's bdi however we want to redirect
1233 * it to our private bdi...
1236 sb->s_bdi = &noop_backing_dev_info;
1238 err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev),
1239 MINOR(fc->dev), suffix);
1243 /* fuse does it's own writeback accounting */
1244 sb->s_bdi->capabilities &= ~BDI_CAP_WRITEBACK_ACCT;
1245 sb->s_bdi->capabilities |= BDI_CAP_STRICTLIMIT;
1248 * For a single fuse filesystem use max 1% of dirty +
1249 * writeback threshold.
1251 * This gives about 1M of write buffer for memory maps on a
1252 * machine with 1G and 10% dirty_ratio, which should be more
1255 * Privileged users can raise it by writing to
1257 * /sys/class/bdi/<bdi>/max_ratio
1259 bdi_set_max_ratio(sb->s_bdi, 1);
1264 struct fuse_dev *fuse_dev_alloc(void)
1266 struct fuse_dev *fud;
1267 struct list_head *pq;
1269 fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL);
1273 pq = kcalloc(FUSE_PQ_HASH_SIZE, sizeof(struct list_head), GFP_KERNEL);
1279 fud->pq.processing = pq;
1280 fuse_pqueue_init(&fud->pq);
1284 EXPORT_SYMBOL_GPL(fuse_dev_alloc);
1286 void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc)
1288 fud->fc = fuse_conn_get(fc);
1289 spin_lock(&fc->lock);
1290 list_add_tail(&fud->entry, &fc->devices);
1291 spin_unlock(&fc->lock);
1293 EXPORT_SYMBOL_GPL(fuse_dev_install);
1295 struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc)
1297 struct fuse_dev *fud;
1299 fud = fuse_dev_alloc();
1303 fuse_dev_install(fud, fc);
1306 EXPORT_SYMBOL_GPL(fuse_dev_alloc_install);
1308 void fuse_dev_free(struct fuse_dev *fud)
1310 struct fuse_conn *fc = fud->fc;
1313 spin_lock(&fc->lock);
1314 list_del(&fud->entry);
1315 spin_unlock(&fc->lock);
1319 kfree(fud->pq.processing);
1322 EXPORT_SYMBOL_GPL(fuse_dev_free);
1324 static void fuse_fill_attr_from_inode(struct fuse_attr *attr,
1325 const struct fuse_inode *fi)
1327 *attr = (struct fuse_attr){
1328 .ino = fi->inode.i_ino,
1329 .size = fi->inode.i_size,
1330 .blocks = fi->inode.i_blocks,
1331 .atime = fi->inode.i_atime.tv_sec,
1332 .mtime = fi->inode.i_mtime.tv_sec,
1333 .ctime = fi->inode.i_ctime.tv_sec,
1334 .atimensec = fi->inode.i_atime.tv_nsec,
1335 .mtimensec = fi->inode.i_mtime.tv_nsec,
1336 .ctimensec = fi->inode.i_ctime.tv_nsec,
1337 .mode = fi->inode.i_mode,
1338 .nlink = fi->inode.i_nlink,
1339 .uid = fi->inode.i_uid.val,
1340 .gid = fi->inode.i_gid.val,
1341 .rdev = fi->inode.i_rdev,
1342 .blksize = 1u << fi->inode.i_blkbits,
1346 static void fuse_sb_defaults(struct super_block *sb)
1348 sb->s_magic = FUSE_SUPER_MAGIC;
1349 sb->s_op = &fuse_super_operations;
1350 sb->s_xattr = fuse_xattr_handlers;
1351 sb->s_maxbytes = MAX_LFS_FILESIZE;
1352 sb->s_time_gran = 1;
1353 sb->s_export_op = &fuse_export_operations;
1354 sb->s_iflags |= SB_I_IMA_UNVERIFIABLE_SIGNATURE;
1355 if (sb->s_user_ns != &init_user_ns)
1356 sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER;
1357 sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION);
1360 * If we are not in the initial user namespace posix
1361 * acls must be translated.
1363 if (sb->s_user_ns != &init_user_ns)
1364 sb->s_xattr = fuse_no_acl_xattr_handlers;
1367 static int fuse_fill_super_submount(struct super_block *sb,
1368 struct fuse_inode *parent_fi)
1370 struct fuse_mount *fm = get_fuse_mount_super(sb);
1371 struct super_block *parent_sb = parent_fi->inode.i_sb;
1372 struct fuse_attr root_attr;
1375 fuse_sb_defaults(sb);
1378 WARN_ON(sb->s_bdi != &noop_backing_dev_info);
1379 sb->s_bdi = bdi_get(parent_sb->s_bdi);
1381 sb->s_xattr = parent_sb->s_xattr;
1382 sb->s_time_gran = parent_sb->s_time_gran;
1383 sb->s_blocksize = parent_sb->s_blocksize;
1384 sb->s_blocksize_bits = parent_sb->s_blocksize_bits;
1385 sb->s_subtype = kstrdup(parent_sb->s_subtype, GFP_KERNEL);
1386 if (parent_sb->s_subtype && !sb->s_subtype)
1389 fuse_fill_attr_from_inode(&root_attr, parent_fi);
1390 root = fuse_iget(sb, parent_fi->nodeid, 0, &root_attr, 0, 0);
1392 * This inode is just a duplicate, so it is not looked up and
1393 * its nlookup should not be incremented. fuse_iget() does
1394 * that, though, so undo it here.
1396 get_fuse_inode(root)->nlookup--;
1397 sb->s_d_op = &fuse_dentry_operations;
1398 sb->s_root = d_make_root(root);
1405 /* Filesystem context private data holds the FUSE inode of the mount point */
1406 static int fuse_get_tree_submount(struct fs_context *fsc)
1408 struct fuse_mount *fm;
1409 struct fuse_inode *mp_fi = fsc->fs_private;
1410 struct fuse_conn *fc = get_fuse_conn(&mp_fi->inode);
1411 struct super_block *sb;
1414 fm = kzalloc(sizeof(struct fuse_mount), GFP_KERNEL);
1418 fm->fc = fuse_conn_get(fc);
1419 fsc->s_fs_info = fm;
1420 sb = sget_fc(fsc, NULL, set_anon_super_fc);
1422 fuse_mount_destroy(fm);
1426 /* Initialize superblock, making @mp_fi its root */
1427 err = fuse_fill_super_submount(sb, mp_fi);
1429 deactivate_locked_super(sb);
1433 down_write(&fc->killsb);
1434 list_add_tail(&fm->fc_entry, &fc->mounts);
1435 up_write(&fc->killsb);
1437 sb->s_flags |= SB_ACTIVE;
1438 fsc->root = dget(sb->s_root);
1443 static const struct fs_context_operations fuse_context_submount_ops = {
1444 .get_tree = fuse_get_tree_submount,
1447 int fuse_init_fs_context_submount(struct fs_context *fsc)
1449 fsc->ops = &fuse_context_submount_ops;
1452 EXPORT_SYMBOL_GPL(fuse_init_fs_context_submount);
1454 int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx)
1456 struct fuse_dev *fud = NULL;
1457 struct fuse_mount *fm = get_fuse_mount_super(sb);
1458 struct fuse_conn *fc = fm->fc;
1460 struct dentry *root_dentry;
1464 if (sb->s_flags & SB_MANDLOCK)
1467 rcu_assign_pointer(fc->curr_bucket, fuse_sync_bucket_alloc());
1468 fuse_sb_defaults(sb);
1473 if (!sb_set_blocksize(sb, ctx->blksize))
1477 sb->s_blocksize = PAGE_SIZE;
1478 sb->s_blocksize_bits = PAGE_SHIFT;
1481 sb->s_subtype = ctx->subtype;
1482 ctx->subtype = NULL;
1483 if (IS_ENABLED(CONFIG_FUSE_DAX)) {
1484 err = fuse_dax_conn_alloc(fc, ctx->dax_dev);
1491 fud = fuse_dev_alloc_install(fc);
1496 fc->dev = sb->s_dev;
1498 err = fuse_bdi_init(fc, sb);
1502 /* Handle umasking inside the fuse code */
1503 if (sb->s_flags & SB_POSIXACL)
1505 sb->s_flags |= SB_POSIXACL;
1507 fc->default_permissions = ctx->default_permissions;
1508 fc->allow_other = ctx->allow_other;
1509 fc->user_id = ctx->user_id;
1510 fc->group_id = ctx->group_id;
1511 fc->legacy_opts_show = ctx->legacy_opts_show;
1512 fc->max_read = max_t(unsigned int, 4096, ctx->max_read);
1513 fc->destroy = ctx->destroy;
1514 fc->no_control = ctx->no_control;
1515 fc->no_force_umount = ctx->no_force_umount;
1518 root = fuse_get_root_inode(sb, ctx->rootmode);
1519 sb->s_d_op = &fuse_root_dentry_operations;
1520 root_dentry = d_make_root(root);
1523 /* Root dentry doesn't have .d_revalidate */
1524 sb->s_d_op = &fuse_dentry_operations;
1526 mutex_lock(&fuse_mutex);
1528 if (ctx->fudptr && *ctx->fudptr)
1531 err = fuse_ctl_add_conn(fc);
1535 list_add_tail(&fc->entry, &fuse_conn_list);
1536 sb->s_root = root_dentry;
1539 mutex_unlock(&fuse_mutex);
1543 mutex_unlock(&fuse_mutex);
1549 if (IS_ENABLED(CONFIG_FUSE_DAX))
1550 fuse_dax_conn_free(fc);
1554 EXPORT_SYMBOL_GPL(fuse_fill_super_common);
1556 static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc)
1558 struct fuse_fs_context *ctx = fsc->fs_private;
1561 if (!ctx->file || !ctx->rootmode_present ||
1562 !ctx->user_id_present || !ctx->group_id_present)
1566 * Require mount to happen from the same user namespace which
1567 * opened /dev/fuse to prevent potential attacks.
1569 if ((ctx->file->f_op != &fuse_dev_operations) ||
1570 (ctx->file->f_cred->user_ns != sb->s_user_ns))
1572 ctx->fudptr = &ctx->file->private_data;
1574 err = fuse_fill_super_common(sb, ctx);
1577 /* file->private_data shall be visible on all CPUs after this */
1579 fuse_send_init(get_fuse_mount_super(sb));
1584 * This is the path where user supplied an already initialized fuse dev. In
1585 * this case never create a new super if the old one is gone.
1587 static int fuse_set_no_super(struct super_block *sb, struct fs_context *fsc)
1592 static int fuse_test_super(struct super_block *sb, struct fs_context *fsc)
1595 return fsc->sget_key == get_fuse_conn_super(sb);
1598 static int fuse_get_tree(struct fs_context *fsc)
1600 struct fuse_fs_context *ctx = fsc->fs_private;
1601 struct fuse_dev *fud;
1602 struct fuse_conn *fc;
1603 struct fuse_mount *fm;
1604 struct super_block *sb;
1607 fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1611 fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1617 fuse_conn_init(fc, fm, fsc->user_ns, &fuse_dev_fiq_ops, NULL);
1618 fc->release = fuse_free_conn;
1620 fsc->s_fs_info = fm;
1622 if (ctx->fd_present)
1623 ctx->file = fget(ctx->fd);
1625 if (IS_ENABLED(CONFIG_BLOCK) && ctx->is_bdev) {
1626 err = get_tree_bdev(fsc, fuse_fill_super);
1630 * While block dev mount can be initialized with a dummy device fd
1631 * (found by device name), normal fuse mounts can't
1638 * Allow creating a fuse mount with an already initialized fuse
1641 fud = READ_ONCE(ctx->file->private_data);
1642 if (ctx->file->f_op == &fuse_dev_operations && fud) {
1643 fsc->sget_key = fud->fc;
1644 sb = sget_fc(fsc, fuse_test_super, fuse_set_no_super);
1645 err = PTR_ERR_OR_ZERO(sb);
1647 fsc->root = dget(sb->s_root);
1649 err = get_tree_nodev(fsc, fuse_fill_super);
1653 fuse_mount_destroy(fm);
1659 static const struct fs_context_operations fuse_context_ops = {
1660 .free = fuse_free_fsc,
1661 .parse_param = fuse_parse_param,
1662 .reconfigure = fuse_reconfigure,
1663 .get_tree = fuse_get_tree,
1667 * Set up the filesystem mount context.
1669 static int fuse_init_fs_context(struct fs_context *fsc)
1671 struct fuse_fs_context *ctx;
1673 ctx = kzalloc(sizeof(struct fuse_fs_context), GFP_KERNEL);
1678 ctx->blksize = FUSE_DEFAULT_BLKSIZE;
1679 ctx->legacy_opts_show = true;
1682 if (fsc->fs_type == &fuseblk_fs_type) {
1683 ctx->is_bdev = true;
1684 ctx->destroy = true;
1688 fsc->fs_private = ctx;
1689 fsc->ops = &fuse_context_ops;
1693 bool fuse_mount_remove(struct fuse_mount *fm)
1695 struct fuse_conn *fc = fm->fc;
1698 down_write(&fc->killsb);
1699 list_del_init(&fm->fc_entry);
1700 if (list_empty(&fc->mounts))
1702 up_write(&fc->killsb);
1706 EXPORT_SYMBOL_GPL(fuse_mount_remove);
1708 void fuse_conn_destroy(struct fuse_mount *fm)
1710 struct fuse_conn *fc = fm->fc;
1713 fuse_send_destroy(fm);
1715 fuse_abort_conn(fc);
1716 fuse_wait_aborted(fc);
1718 if (!list_empty(&fc->entry)) {
1719 mutex_lock(&fuse_mutex);
1720 list_del(&fc->entry);
1721 fuse_ctl_remove_conn(fc);
1722 mutex_unlock(&fuse_mutex);
1725 EXPORT_SYMBOL_GPL(fuse_conn_destroy);
1727 static void fuse_sb_destroy(struct super_block *sb)
1729 struct fuse_mount *fm = get_fuse_mount_super(sb);
1733 last = fuse_mount_remove(fm);
1735 fuse_conn_destroy(fm);
1739 void fuse_mount_destroy(struct fuse_mount *fm)
1741 fuse_conn_put(fm->fc);
1744 EXPORT_SYMBOL(fuse_mount_destroy);
1746 static void fuse_kill_sb_anon(struct super_block *sb)
1748 fuse_sb_destroy(sb);
1749 kill_anon_super(sb);
1750 fuse_mount_destroy(get_fuse_mount_super(sb));
1753 static struct file_system_type fuse_fs_type = {
1754 .owner = THIS_MODULE,
1756 .fs_flags = FS_HAS_SUBTYPE | FS_USERNS_MOUNT,
1757 .init_fs_context = fuse_init_fs_context,
1758 .parameters = fuse_fs_parameters,
1759 .kill_sb = fuse_kill_sb_anon,
1761 MODULE_ALIAS_FS("fuse");
1764 static void fuse_kill_sb_blk(struct super_block *sb)
1766 fuse_sb_destroy(sb);
1767 kill_block_super(sb);
1768 fuse_mount_destroy(get_fuse_mount_super(sb));
1771 static struct file_system_type fuseblk_fs_type = {
1772 .owner = THIS_MODULE,
1774 .init_fs_context = fuse_init_fs_context,
1775 .parameters = fuse_fs_parameters,
1776 .kill_sb = fuse_kill_sb_blk,
1777 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1779 MODULE_ALIAS_FS("fuseblk");
1781 static inline int register_fuseblk(void)
1783 return register_filesystem(&fuseblk_fs_type);
1786 static inline void unregister_fuseblk(void)
1788 unregister_filesystem(&fuseblk_fs_type);
1791 static inline int register_fuseblk(void)
1796 static inline void unregister_fuseblk(void)
1801 static void fuse_inode_init_once(void *foo)
1803 struct inode *inode = foo;
1805 inode_init_once(inode);
1808 static int __init fuse_fs_init(void)
1812 fuse_inode_cachep = kmem_cache_create("fuse_inode",
1813 sizeof(struct fuse_inode), 0,
1814 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT|SLAB_RECLAIM_ACCOUNT,
1815 fuse_inode_init_once);
1817 if (!fuse_inode_cachep)
1820 err = register_fuseblk();
1824 err = register_filesystem(&fuse_fs_type);
1831 unregister_fuseblk();
1833 kmem_cache_destroy(fuse_inode_cachep);
1838 static void fuse_fs_cleanup(void)
1840 unregister_filesystem(&fuse_fs_type);
1841 unregister_fuseblk();
1844 * Make sure all delayed rcu free inodes are flushed before we
1848 kmem_cache_destroy(fuse_inode_cachep);
1851 static struct kobject *fuse_kobj;
1853 static int fuse_sysfs_init(void)
1857 fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1863 err = sysfs_create_mount_point(fuse_kobj, "connections");
1865 goto out_fuse_unregister;
1869 out_fuse_unregister:
1870 kobject_put(fuse_kobj);
1875 static void fuse_sysfs_cleanup(void)
1877 sysfs_remove_mount_point(fuse_kobj, "connections");
1878 kobject_put(fuse_kobj);
1881 static int __init fuse_init(void)
1885 pr_info("init (API version %i.%i)\n",
1886 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1888 INIT_LIST_HEAD(&fuse_conn_list);
1889 res = fuse_fs_init();
1893 res = fuse_dev_init();
1895 goto err_fs_cleanup;
1897 res = fuse_sysfs_init();
1899 goto err_dev_cleanup;
1901 res = fuse_ctl_init();
1903 goto err_sysfs_cleanup;
1905 sanitize_global_limit(&max_user_bgreq);
1906 sanitize_global_limit(&max_user_congthresh);
1911 fuse_sysfs_cleanup();
1920 static void __exit fuse_exit(void)
1925 fuse_sysfs_cleanup();
1930 module_init(fuse_init);
1931 module_exit(fuse_exit);