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 *fc)
142 struct super_block *sb = fc->root->d_sb;
145 if (fc->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 fuse_put_super(struct super_block *sb)
462 struct fuse_mount *fm = get_fuse_mount_super(sb);
464 fuse_conn_put(fm->fc);
468 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
470 stbuf->f_type = FUSE_SUPER_MAGIC;
471 stbuf->f_bsize = attr->bsize;
472 stbuf->f_frsize = attr->frsize;
473 stbuf->f_blocks = attr->blocks;
474 stbuf->f_bfree = attr->bfree;
475 stbuf->f_bavail = attr->bavail;
476 stbuf->f_files = attr->files;
477 stbuf->f_ffree = attr->ffree;
478 stbuf->f_namelen = attr->namelen;
479 /* fsid is left zero */
482 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
484 struct super_block *sb = dentry->d_sb;
485 struct fuse_mount *fm = get_fuse_mount_super(sb);
487 struct fuse_statfs_out outarg;
490 if (!fuse_allow_current_process(fm->fc)) {
491 buf->f_type = FUSE_SUPER_MAGIC;
495 memset(&outarg, 0, sizeof(outarg));
497 args.opcode = FUSE_STATFS;
498 args.nodeid = get_node_id(d_inode(dentry));
499 args.out_numargs = 1;
500 args.out_args[0].size = sizeof(outarg);
501 args.out_args[0].value = &outarg;
502 err = fuse_simple_request(fm, &args);
504 convert_fuse_statfs(buf, &outarg.st);
508 static int fuse_sync_fs(struct super_block *sb, int wait)
510 struct fuse_mount *fm = get_fuse_mount_super(sb);
511 struct fuse_conn *fc = fm->fc;
512 struct fuse_syncfs_in inarg;
517 * Userspace cannot handle the wait == 0 case. Avoid a
518 * gratuitous roundtrip.
523 /* The filesystem is being unmounted. Nothing to do. */
530 memset(&inarg, 0, sizeof(inarg));
532 args.in_args[0].size = sizeof(inarg);
533 args.in_args[0].value = &inarg;
534 args.opcode = FUSE_SYNCFS;
535 args.nodeid = get_node_id(sb->s_root->d_inode);
536 args.out_numargs = 0;
538 err = fuse_simple_request(fm, &args);
539 if (err == -ENOSYS) {
554 OPT_DEFAULT_PERMISSIONS,
561 static const struct fs_parameter_spec fuse_fs_parameters[] = {
562 fsparam_string ("source", OPT_SOURCE),
563 fsparam_u32 ("fd", OPT_FD),
564 fsparam_u32oct ("rootmode", OPT_ROOTMODE),
565 fsparam_u32 ("user_id", OPT_USER_ID),
566 fsparam_u32 ("group_id", OPT_GROUP_ID),
567 fsparam_flag ("default_permissions", OPT_DEFAULT_PERMISSIONS),
568 fsparam_flag ("allow_other", OPT_ALLOW_OTHER),
569 fsparam_u32 ("max_read", OPT_MAX_READ),
570 fsparam_u32 ("blksize", OPT_BLKSIZE),
571 fsparam_string ("subtype", OPT_SUBTYPE),
575 static int fuse_parse_param(struct fs_context *fc, struct fs_parameter *param)
577 struct fs_parse_result result;
578 struct fuse_fs_context *ctx = fc->fs_private;
581 if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
583 * Ignore options coming from mount(MS_REMOUNT) for backward
589 return invalfc(fc, "No changes allowed in reconfigure");
592 opt = fs_parse(fc, fuse_fs_parameters, param, &result);
599 return invalfc(fc, "Multiple sources specified");
600 fc->source = param->string;
601 param->string = NULL;
606 return invalfc(fc, "Multiple subtypes specified");
607 ctx->subtype = param->string;
608 param->string = NULL;
612 ctx->fd = result.uint_32;
613 ctx->fd_present = true;
617 if (!fuse_valid_type(result.uint_32))
618 return invalfc(fc, "Invalid rootmode");
619 ctx->rootmode = result.uint_32;
620 ctx->rootmode_present = true;
624 ctx->user_id = make_kuid(fc->user_ns, result.uint_32);
625 if (!uid_valid(ctx->user_id))
626 return invalfc(fc, "Invalid user_id");
627 ctx->user_id_present = true;
631 ctx->group_id = make_kgid(fc->user_ns, result.uint_32);
632 if (!gid_valid(ctx->group_id))
633 return invalfc(fc, "Invalid group_id");
634 ctx->group_id_present = true;
637 case OPT_DEFAULT_PERMISSIONS:
638 ctx->default_permissions = true;
641 case OPT_ALLOW_OTHER:
642 ctx->allow_other = true;
646 ctx->max_read = result.uint_32;
651 return invalfc(fc, "blksize only supported for fuseblk");
652 ctx->blksize = result.uint_32;
662 static void fuse_free_fc(struct fs_context *fc)
664 struct fuse_fs_context *ctx = fc->fs_private;
672 static int fuse_show_options(struct seq_file *m, struct dentry *root)
674 struct super_block *sb = root->d_sb;
675 struct fuse_conn *fc = get_fuse_conn_super(sb);
677 if (fc->legacy_opts_show) {
678 seq_printf(m, ",user_id=%u",
679 from_kuid_munged(fc->user_ns, fc->user_id));
680 seq_printf(m, ",group_id=%u",
681 from_kgid_munged(fc->user_ns, fc->group_id));
682 if (fc->default_permissions)
683 seq_puts(m, ",default_permissions");
685 seq_puts(m, ",allow_other");
686 if (fc->max_read != ~0)
687 seq_printf(m, ",max_read=%u", fc->max_read);
688 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
689 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
691 #ifdef CONFIG_FUSE_DAX
699 static void fuse_iqueue_init(struct fuse_iqueue *fiq,
700 const struct fuse_iqueue_ops *ops,
703 memset(fiq, 0, sizeof(struct fuse_iqueue));
704 spin_lock_init(&fiq->lock);
705 init_waitqueue_head(&fiq->waitq);
706 INIT_LIST_HEAD(&fiq->pending);
707 INIT_LIST_HEAD(&fiq->interrupts);
708 fiq->forget_list_tail = &fiq->forget_list_head;
714 static void fuse_pqueue_init(struct fuse_pqueue *fpq)
718 spin_lock_init(&fpq->lock);
719 for (i = 0; i < FUSE_PQ_HASH_SIZE; i++)
720 INIT_LIST_HEAD(&fpq->processing[i]);
721 INIT_LIST_HEAD(&fpq->io);
725 void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
726 struct user_namespace *user_ns,
727 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv)
729 memset(fc, 0, sizeof(*fc));
730 spin_lock_init(&fc->lock);
731 spin_lock_init(&fc->bg_lock);
732 init_rwsem(&fc->killsb);
733 refcount_set(&fc->count, 1);
734 atomic_set(&fc->dev_count, 1);
735 init_waitqueue_head(&fc->blocked_waitq);
736 fuse_iqueue_init(&fc->iq, fiq_ops, fiq_priv);
737 INIT_LIST_HEAD(&fc->bg_queue);
738 INIT_LIST_HEAD(&fc->entry);
739 INIT_LIST_HEAD(&fc->devices);
740 atomic_set(&fc->num_waiting, 0);
741 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
742 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
743 atomic64_set(&fc->khctr, 0);
744 fc->polled_files = RB_ROOT;
748 atomic64_set(&fc->attr_version, 1);
749 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
750 fc->pid_ns = get_pid_ns(task_active_pid_ns(current));
751 fc->user_ns = get_user_ns(user_ns);
752 fc->max_pages = FUSE_DEFAULT_MAX_PAGES_PER_REQ;
753 fc->max_pages_limit = FUSE_MAX_MAX_PAGES;
755 INIT_LIST_HEAD(&fc->mounts);
756 list_add(&fm->fc_entry, &fc->mounts);
759 EXPORT_SYMBOL_GPL(fuse_conn_init);
761 void fuse_conn_put(struct fuse_conn *fc)
763 if (refcount_dec_and_test(&fc->count)) {
764 struct fuse_iqueue *fiq = &fc->iq;
766 if (IS_ENABLED(CONFIG_FUSE_DAX))
767 fuse_dax_conn_free(fc);
768 if (fiq->ops->release)
769 fiq->ops->release(fiq);
770 put_pid_ns(fc->pid_ns);
771 put_user_ns(fc->user_ns);
775 EXPORT_SYMBOL_GPL(fuse_conn_put);
777 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
779 refcount_inc(&fc->count);
782 EXPORT_SYMBOL_GPL(fuse_conn_get);
784 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
786 struct fuse_attr attr;
787 memset(&attr, 0, sizeof(attr));
790 attr.ino = FUSE_ROOT_ID;
792 return fuse_iget(sb, 1, 0, &attr, 0, 0);
795 struct fuse_inode_handle {
800 static struct dentry *fuse_get_dentry(struct super_block *sb,
801 struct fuse_inode_handle *handle)
803 struct fuse_conn *fc = get_fuse_conn_super(sb);
805 struct dentry *entry;
808 if (handle->nodeid == 0)
811 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
813 struct fuse_entry_out outarg;
814 const struct qstr name = QSTR_INIT(".", 1);
816 if (!fc->export_support)
819 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
821 if (err && err != -ENOENT)
828 if (get_node_id(inode) != handle->nodeid)
832 if (inode->i_generation != handle->generation)
835 entry = d_obtain_alias(inode);
836 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
837 fuse_invalidate_entry_cache(entry);
847 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
848 struct inode *parent)
850 int len = parent ? 6 : 3;
854 if (*max_len < len) {
856 return FILEID_INVALID;
859 nodeid = get_fuse_inode(inode)->nodeid;
860 generation = inode->i_generation;
862 fh[0] = (u32)(nodeid >> 32);
863 fh[1] = (u32)(nodeid & 0xffffffff);
867 nodeid = get_fuse_inode(parent)->nodeid;
868 generation = parent->i_generation;
870 fh[3] = (u32)(nodeid >> 32);
871 fh[4] = (u32)(nodeid & 0xffffffff);
876 return parent ? 0x82 : 0x81;
879 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
880 struct fid *fid, int fh_len, int fh_type)
882 struct fuse_inode_handle handle;
884 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
887 handle.nodeid = (u64) fid->raw[0] << 32;
888 handle.nodeid |= (u64) fid->raw[1];
889 handle.generation = fid->raw[2];
890 return fuse_get_dentry(sb, &handle);
893 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
894 struct fid *fid, int fh_len, int fh_type)
896 struct fuse_inode_handle parent;
898 if (fh_type != 0x82 || fh_len < 6)
901 parent.nodeid = (u64) fid->raw[3] << 32;
902 parent.nodeid |= (u64) fid->raw[4];
903 parent.generation = fid->raw[5];
904 return fuse_get_dentry(sb, &parent);
907 static struct dentry *fuse_get_parent(struct dentry *child)
909 struct inode *child_inode = d_inode(child);
910 struct fuse_conn *fc = get_fuse_conn(child_inode);
912 struct dentry *parent;
913 struct fuse_entry_out outarg;
916 if (!fc->export_support)
917 return ERR_PTR(-ESTALE);
919 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
920 &dotdot_name, &outarg, &inode);
923 return ERR_PTR(-ESTALE);
927 parent = d_obtain_alias(inode);
928 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
929 fuse_invalidate_entry_cache(parent);
934 static const struct export_operations fuse_export_operations = {
935 .fh_to_dentry = fuse_fh_to_dentry,
936 .fh_to_parent = fuse_fh_to_parent,
937 .encode_fh = fuse_encode_fh,
938 .get_parent = fuse_get_parent,
941 static const struct super_operations fuse_super_operations = {
942 .alloc_inode = fuse_alloc_inode,
943 .free_inode = fuse_free_inode,
944 .evict_inode = fuse_evict_inode,
945 .write_inode = fuse_write_inode,
946 .drop_inode = generic_delete_inode,
947 .put_super = fuse_put_super,
948 .umount_begin = fuse_umount_begin,
949 .statfs = fuse_statfs,
950 .sync_fs = fuse_sync_fs,
951 .show_options = fuse_show_options,
954 static void sanitize_global_limit(unsigned *limit)
957 * The default maximum number of async requests is calculated to consume
958 * 1/2^13 of the total memory, assuming 392 bytes per request.
961 *limit = ((totalram_pages() << PAGE_SHIFT) >> 13) / 392;
963 if (*limit >= 1 << 16)
964 *limit = (1 << 16) - 1;
967 static int set_global_limit(const char *val, const struct kernel_param *kp)
971 rv = param_set_uint(val, kp);
975 sanitize_global_limit((unsigned *)kp->arg);
980 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
982 int cap_sys_admin = capable(CAP_SYS_ADMIN);
987 sanitize_global_limit(&max_user_bgreq);
988 sanitize_global_limit(&max_user_congthresh);
990 spin_lock(&fc->bg_lock);
991 if (arg->max_background) {
992 fc->max_background = arg->max_background;
994 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
995 fc->max_background = max_user_bgreq;
997 if (arg->congestion_threshold) {
998 fc->congestion_threshold = arg->congestion_threshold;
1000 if (!cap_sys_admin &&
1001 fc->congestion_threshold > max_user_congthresh)
1002 fc->congestion_threshold = max_user_congthresh;
1004 spin_unlock(&fc->bg_lock);
1007 struct fuse_init_args {
1008 struct fuse_args args;
1009 struct fuse_init_in in;
1010 struct fuse_init_out out;
1013 static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args,
1016 struct fuse_conn *fc = fm->fc;
1017 struct fuse_init_args *ia = container_of(args, typeof(*ia), args);
1018 struct fuse_init_out *arg = &ia->out;
1021 if (error || arg->major != FUSE_KERNEL_VERSION)
1024 unsigned long ra_pages;
1026 process_init_limits(fc, arg);
1028 if (arg->minor >= 6) {
1029 ra_pages = arg->max_readahead / PAGE_SIZE;
1030 if (arg->flags & FUSE_ASYNC_READ)
1032 if (!(arg->flags & FUSE_POSIX_LOCKS))
1034 if (arg->minor >= 17) {
1035 if (!(arg->flags & FUSE_FLOCK_LOCKS))
1038 if (!(arg->flags & FUSE_POSIX_LOCKS))
1041 if (arg->flags & FUSE_ATOMIC_O_TRUNC)
1042 fc->atomic_o_trunc = 1;
1043 if (arg->minor >= 9) {
1044 /* LOOKUP has dependency on proto version */
1045 if (arg->flags & FUSE_EXPORT_SUPPORT)
1046 fc->export_support = 1;
1048 if (arg->flags & FUSE_BIG_WRITES)
1050 if (arg->flags & FUSE_DONT_MASK)
1052 if (arg->flags & FUSE_AUTO_INVAL_DATA)
1053 fc->auto_inval_data = 1;
1054 else if (arg->flags & FUSE_EXPLICIT_INVAL_DATA)
1055 fc->explicit_inval_data = 1;
1056 if (arg->flags & FUSE_DO_READDIRPLUS) {
1057 fc->do_readdirplus = 1;
1058 if (arg->flags & FUSE_READDIRPLUS_AUTO)
1059 fc->readdirplus_auto = 1;
1061 if (arg->flags & FUSE_ASYNC_DIO)
1063 if (arg->flags & FUSE_WRITEBACK_CACHE)
1064 fc->writeback_cache = 1;
1065 if (arg->flags & FUSE_PARALLEL_DIROPS)
1066 fc->parallel_dirops = 1;
1067 if (arg->flags & FUSE_HANDLE_KILLPRIV)
1068 fc->handle_killpriv = 1;
1069 if (arg->time_gran && arg->time_gran <= 1000000000)
1070 fm->sb->s_time_gran = arg->time_gran;
1071 if ((arg->flags & FUSE_POSIX_ACL)) {
1072 fc->default_permissions = 1;
1074 fm->sb->s_xattr = fuse_acl_xattr_handlers;
1076 if (arg->flags & FUSE_CACHE_SYMLINKS)
1077 fc->cache_symlinks = 1;
1078 if (arg->flags & FUSE_ABORT_ERROR)
1080 if (arg->flags & FUSE_MAX_PAGES) {
1082 min_t(unsigned int, fc->max_pages_limit,
1083 max_t(unsigned int, arg->max_pages, 1));
1085 if (IS_ENABLED(CONFIG_FUSE_DAX) &&
1086 arg->flags & FUSE_MAP_ALIGNMENT &&
1087 !fuse_dax_check_alignment(fc, arg->map_alignment)) {
1090 if (arg->flags & FUSE_HANDLE_KILLPRIV_V2) {
1091 fc->handle_killpriv_v2 = 1;
1092 fm->sb->s_flags |= SB_NOSEC;
1094 if (arg->flags & FUSE_SETXATTR_EXT)
1095 fc->setxattr_ext = 1;
1097 ra_pages = fc->max_read / PAGE_SIZE;
1102 fm->sb->s_bdi->ra_pages =
1103 min(fm->sb->s_bdi->ra_pages, ra_pages);
1104 fc->minor = arg->minor;
1105 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
1106 fc->max_write = max_t(unsigned, 4096, fc->max_write);
1116 fuse_set_initialized(fc);
1117 wake_up_all(&fc->blocked_waitq);
1120 void fuse_send_init(struct fuse_mount *fm)
1122 struct fuse_init_args *ia;
1124 ia = kzalloc(sizeof(*ia), GFP_KERNEL | __GFP_NOFAIL);
1126 ia->in.major = FUSE_KERNEL_VERSION;
1127 ia->in.minor = FUSE_KERNEL_MINOR_VERSION;
1128 ia->in.max_readahead = fm->sb->s_bdi->ra_pages * PAGE_SIZE;
1130 FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
1131 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
1132 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
1133 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
1134 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
1135 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT |
1136 FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL |
1137 FUSE_ABORT_ERROR | FUSE_MAX_PAGES | FUSE_CACHE_SYMLINKS |
1138 FUSE_NO_OPENDIR_SUPPORT | FUSE_EXPLICIT_INVAL_DATA |
1139 FUSE_HANDLE_KILLPRIV_V2 | FUSE_SETXATTR_EXT;
1140 #ifdef CONFIG_FUSE_DAX
1142 ia->in.flags |= FUSE_MAP_ALIGNMENT;
1144 if (fm->fc->auto_submounts)
1145 ia->in.flags |= FUSE_SUBMOUNTS;
1147 ia->args.opcode = FUSE_INIT;
1148 ia->args.in_numargs = 1;
1149 ia->args.in_args[0].size = sizeof(ia->in);
1150 ia->args.in_args[0].value = &ia->in;
1151 ia->args.out_numargs = 1;
1152 /* Variable length argument used for backward compatibility
1153 with interface version < 7.5. Rest of init_out is zeroed
1154 by do_get_request(), so a short reply is not a problem */
1155 ia->args.out_argvar = true;
1156 ia->args.out_args[0].size = sizeof(ia->out);
1157 ia->args.out_args[0].value = &ia->out;
1158 ia->args.force = true;
1159 ia->args.nocreds = true;
1160 ia->args.end = process_init_reply;
1162 if (fuse_simple_background(fm, &ia->args, GFP_KERNEL) != 0)
1163 process_init_reply(fm, &ia->args, -ENOTCONN);
1165 EXPORT_SYMBOL_GPL(fuse_send_init);
1167 void fuse_free_conn(struct fuse_conn *fc)
1169 WARN_ON(!list_empty(&fc->devices));
1172 EXPORT_SYMBOL_GPL(fuse_free_conn);
1174 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
1180 suffix = "-fuseblk";
1182 * sb->s_bdi points to blkdev's bdi however we want to redirect
1183 * it to our private bdi...
1186 sb->s_bdi = &noop_backing_dev_info;
1188 err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev),
1189 MINOR(fc->dev), suffix);
1193 /* fuse does it's own writeback accounting */
1194 sb->s_bdi->capabilities &= ~BDI_CAP_WRITEBACK_ACCT;
1195 sb->s_bdi->capabilities |= BDI_CAP_STRICTLIMIT;
1198 * For a single fuse filesystem use max 1% of dirty +
1199 * writeback threshold.
1201 * This gives about 1M of write buffer for memory maps on a
1202 * machine with 1G and 10% dirty_ratio, which should be more
1205 * Privileged users can raise it by writing to
1207 * /sys/class/bdi/<bdi>/max_ratio
1209 bdi_set_max_ratio(sb->s_bdi, 1);
1214 struct fuse_dev *fuse_dev_alloc(void)
1216 struct fuse_dev *fud;
1217 struct list_head *pq;
1219 fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL);
1223 pq = kcalloc(FUSE_PQ_HASH_SIZE, sizeof(struct list_head), GFP_KERNEL);
1229 fud->pq.processing = pq;
1230 fuse_pqueue_init(&fud->pq);
1234 EXPORT_SYMBOL_GPL(fuse_dev_alloc);
1236 void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc)
1238 fud->fc = fuse_conn_get(fc);
1239 spin_lock(&fc->lock);
1240 list_add_tail(&fud->entry, &fc->devices);
1241 spin_unlock(&fc->lock);
1243 EXPORT_SYMBOL_GPL(fuse_dev_install);
1245 struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc)
1247 struct fuse_dev *fud;
1249 fud = fuse_dev_alloc();
1253 fuse_dev_install(fud, fc);
1256 EXPORT_SYMBOL_GPL(fuse_dev_alloc_install);
1258 void fuse_dev_free(struct fuse_dev *fud)
1260 struct fuse_conn *fc = fud->fc;
1263 spin_lock(&fc->lock);
1264 list_del(&fud->entry);
1265 spin_unlock(&fc->lock);
1269 kfree(fud->pq.processing);
1272 EXPORT_SYMBOL_GPL(fuse_dev_free);
1274 static void fuse_fill_attr_from_inode(struct fuse_attr *attr,
1275 const struct fuse_inode *fi)
1277 *attr = (struct fuse_attr){
1278 .ino = fi->inode.i_ino,
1279 .size = fi->inode.i_size,
1280 .blocks = fi->inode.i_blocks,
1281 .atime = fi->inode.i_atime.tv_sec,
1282 .mtime = fi->inode.i_mtime.tv_sec,
1283 .ctime = fi->inode.i_ctime.tv_sec,
1284 .atimensec = fi->inode.i_atime.tv_nsec,
1285 .mtimensec = fi->inode.i_mtime.tv_nsec,
1286 .ctimensec = fi->inode.i_ctime.tv_nsec,
1287 .mode = fi->inode.i_mode,
1288 .nlink = fi->inode.i_nlink,
1289 .uid = fi->inode.i_uid.val,
1290 .gid = fi->inode.i_gid.val,
1291 .rdev = fi->inode.i_rdev,
1292 .blksize = 1u << fi->inode.i_blkbits,
1296 static void fuse_sb_defaults(struct super_block *sb)
1298 sb->s_magic = FUSE_SUPER_MAGIC;
1299 sb->s_op = &fuse_super_operations;
1300 sb->s_xattr = fuse_xattr_handlers;
1301 sb->s_maxbytes = MAX_LFS_FILESIZE;
1302 sb->s_time_gran = 1;
1303 sb->s_export_op = &fuse_export_operations;
1304 sb->s_iflags |= SB_I_IMA_UNVERIFIABLE_SIGNATURE;
1305 if (sb->s_user_ns != &init_user_ns)
1306 sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER;
1307 sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION);
1310 * If we are not in the initial user namespace posix
1311 * acls must be translated.
1313 if (sb->s_user_ns != &init_user_ns)
1314 sb->s_xattr = fuse_no_acl_xattr_handlers;
1317 static int fuse_fill_super_submount(struct super_block *sb,
1318 struct fuse_inode *parent_fi)
1320 struct fuse_mount *fm = get_fuse_mount_super(sb);
1321 struct super_block *parent_sb = parent_fi->inode.i_sb;
1322 struct fuse_attr root_attr;
1325 fuse_sb_defaults(sb);
1328 WARN_ON(sb->s_bdi != &noop_backing_dev_info);
1329 sb->s_bdi = bdi_get(parent_sb->s_bdi);
1331 sb->s_xattr = parent_sb->s_xattr;
1332 sb->s_time_gran = parent_sb->s_time_gran;
1333 sb->s_blocksize = parent_sb->s_blocksize;
1334 sb->s_blocksize_bits = parent_sb->s_blocksize_bits;
1335 sb->s_subtype = kstrdup(parent_sb->s_subtype, GFP_KERNEL);
1336 if (parent_sb->s_subtype && !sb->s_subtype)
1339 fuse_fill_attr_from_inode(&root_attr, parent_fi);
1340 root = fuse_iget(sb, parent_fi->nodeid, 0, &root_attr, 0, 0);
1342 * This inode is just a duplicate, so it is not looked up and
1343 * its nlookup should not be incremented. fuse_iget() does
1344 * that, though, so undo it here.
1346 get_fuse_inode(root)->nlookup--;
1347 sb->s_d_op = &fuse_dentry_operations;
1348 sb->s_root = d_make_root(root);
1355 /* Filesystem context private data holds the FUSE inode of the mount point */
1356 static int fuse_get_tree_submount(struct fs_context *fsc)
1358 struct fuse_mount *fm;
1359 struct fuse_inode *mp_fi = fsc->fs_private;
1360 struct fuse_conn *fc = get_fuse_conn(&mp_fi->inode);
1361 struct super_block *sb;
1364 fm = kzalloc(sizeof(struct fuse_mount), GFP_KERNEL);
1368 fsc->s_fs_info = fm;
1369 sb = sget_fc(fsc, NULL, set_anon_super_fc);
1374 fm->fc = fuse_conn_get(fc);
1376 /* Initialize superblock, making @mp_fi its root */
1377 err = fuse_fill_super_submount(sb, mp_fi);
1381 sb->s_fs_info = NULL;
1382 deactivate_locked_super(sb);
1386 down_write(&fc->killsb);
1387 list_add_tail(&fm->fc_entry, &fc->mounts);
1388 up_write(&fc->killsb);
1390 sb->s_flags |= SB_ACTIVE;
1391 fsc->root = dget(sb->s_root);
1396 static const struct fs_context_operations fuse_context_submount_ops = {
1397 .get_tree = fuse_get_tree_submount,
1400 int fuse_init_fs_context_submount(struct fs_context *fsc)
1402 fsc->ops = &fuse_context_submount_ops;
1405 EXPORT_SYMBOL_GPL(fuse_init_fs_context_submount);
1407 int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx)
1409 struct fuse_dev *fud = NULL;
1410 struct fuse_mount *fm = get_fuse_mount_super(sb);
1411 struct fuse_conn *fc = fm->fc;
1413 struct dentry *root_dentry;
1417 if (sb->s_flags & SB_MANDLOCK)
1420 fuse_sb_defaults(sb);
1425 if (!sb_set_blocksize(sb, ctx->blksize))
1429 sb->s_blocksize = PAGE_SIZE;
1430 sb->s_blocksize_bits = PAGE_SHIFT;
1433 sb->s_subtype = ctx->subtype;
1434 ctx->subtype = NULL;
1435 if (IS_ENABLED(CONFIG_FUSE_DAX)) {
1436 err = fuse_dax_conn_alloc(fc, ctx->dax_dev);
1443 fud = fuse_dev_alloc_install(fc);
1448 fc->dev = sb->s_dev;
1450 err = fuse_bdi_init(fc, sb);
1454 /* Handle umasking inside the fuse code */
1455 if (sb->s_flags & SB_POSIXACL)
1457 sb->s_flags |= SB_POSIXACL;
1459 fc->default_permissions = ctx->default_permissions;
1460 fc->allow_other = ctx->allow_other;
1461 fc->user_id = ctx->user_id;
1462 fc->group_id = ctx->group_id;
1463 fc->legacy_opts_show = ctx->legacy_opts_show;
1464 fc->max_read = max_t(unsigned int, 4096, ctx->max_read);
1465 fc->destroy = ctx->destroy;
1466 fc->no_control = ctx->no_control;
1467 fc->no_force_umount = ctx->no_force_umount;
1470 root = fuse_get_root_inode(sb, ctx->rootmode);
1471 sb->s_d_op = &fuse_root_dentry_operations;
1472 root_dentry = d_make_root(root);
1475 /* Root dentry doesn't have .d_revalidate */
1476 sb->s_d_op = &fuse_dentry_operations;
1478 mutex_lock(&fuse_mutex);
1480 if (ctx->fudptr && *ctx->fudptr)
1483 err = fuse_ctl_add_conn(fc);
1487 list_add_tail(&fc->entry, &fuse_conn_list);
1488 sb->s_root = root_dentry;
1491 mutex_unlock(&fuse_mutex);
1495 mutex_unlock(&fuse_mutex);
1501 if (IS_ENABLED(CONFIG_FUSE_DAX))
1502 fuse_dax_conn_free(fc);
1506 EXPORT_SYMBOL_GPL(fuse_fill_super_common);
1508 static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc)
1510 struct fuse_fs_context *ctx = fsc->fs_private;
1513 struct fuse_conn *fc;
1514 struct fuse_mount *fm;
1517 file = fget(ctx->fd);
1522 * Require mount to happen from the same user namespace which
1523 * opened /dev/fuse to prevent potential attacks.
1525 if ((file->f_op != &fuse_dev_operations) ||
1526 (file->f_cred->user_ns != sb->s_user_ns))
1528 ctx->fudptr = &file->private_data;
1530 fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1535 fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1541 fuse_conn_init(fc, fm, sb->s_user_ns, &fuse_dev_fiq_ops, NULL);
1542 fc->release = fuse_free_conn;
1546 err = fuse_fill_super_common(sb, ctx);
1550 * atomic_dec_and_test() in fput() provides the necessary
1551 * memory barrier for file->private_data to be visible on all
1555 fuse_send_init(get_fuse_mount_super(sb));
1561 sb->s_fs_info = NULL;
1568 static int fuse_get_tree(struct fs_context *fc)
1570 struct fuse_fs_context *ctx = fc->fs_private;
1572 if (!ctx->fd_present || !ctx->rootmode_present ||
1573 !ctx->user_id_present || !ctx->group_id_present)
1578 return get_tree_bdev(fc, fuse_fill_super);
1581 return get_tree_nodev(fc, fuse_fill_super);
1584 static const struct fs_context_operations fuse_context_ops = {
1585 .free = fuse_free_fc,
1586 .parse_param = fuse_parse_param,
1587 .reconfigure = fuse_reconfigure,
1588 .get_tree = fuse_get_tree,
1592 * Set up the filesystem mount context.
1594 static int fuse_init_fs_context(struct fs_context *fc)
1596 struct fuse_fs_context *ctx;
1598 ctx = kzalloc(sizeof(struct fuse_fs_context), GFP_KERNEL);
1603 ctx->blksize = FUSE_DEFAULT_BLKSIZE;
1604 ctx->legacy_opts_show = true;
1607 if (fc->fs_type == &fuseblk_fs_type) {
1608 ctx->is_bdev = true;
1609 ctx->destroy = true;
1613 fc->fs_private = ctx;
1614 fc->ops = &fuse_context_ops;
1618 bool fuse_mount_remove(struct fuse_mount *fm)
1620 struct fuse_conn *fc = fm->fc;
1623 down_write(&fc->killsb);
1624 list_del_init(&fm->fc_entry);
1625 if (list_empty(&fc->mounts))
1627 up_write(&fc->killsb);
1631 EXPORT_SYMBOL_GPL(fuse_mount_remove);
1633 void fuse_conn_destroy(struct fuse_mount *fm)
1635 struct fuse_conn *fc = fm->fc;
1638 fuse_send_destroy(fm);
1640 fuse_abort_conn(fc);
1641 fuse_wait_aborted(fc);
1643 if (!list_empty(&fc->entry)) {
1644 mutex_lock(&fuse_mutex);
1645 list_del(&fc->entry);
1646 fuse_ctl_remove_conn(fc);
1647 mutex_unlock(&fuse_mutex);
1650 EXPORT_SYMBOL_GPL(fuse_conn_destroy);
1652 static void fuse_sb_destroy(struct super_block *sb)
1654 struct fuse_mount *fm = get_fuse_mount_super(sb);
1658 last = fuse_mount_remove(fm);
1660 fuse_conn_destroy(fm);
1664 static void fuse_kill_sb_anon(struct super_block *sb)
1666 fuse_sb_destroy(sb);
1667 kill_anon_super(sb);
1670 static struct file_system_type fuse_fs_type = {
1671 .owner = THIS_MODULE,
1673 .fs_flags = FS_HAS_SUBTYPE | FS_USERNS_MOUNT,
1674 .init_fs_context = fuse_init_fs_context,
1675 .parameters = fuse_fs_parameters,
1676 .kill_sb = fuse_kill_sb_anon,
1678 MODULE_ALIAS_FS("fuse");
1681 static void fuse_kill_sb_blk(struct super_block *sb)
1683 fuse_sb_destroy(sb);
1684 kill_block_super(sb);
1687 static struct file_system_type fuseblk_fs_type = {
1688 .owner = THIS_MODULE,
1690 .init_fs_context = fuse_init_fs_context,
1691 .parameters = fuse_fs_parameters,
1692 .kill_sb = fuse_kill_sb_blk,
1693 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1695 MODULE_ALIAS_FS("fuseblk");
1697 static inline int register_fuseblk(void)
1699 return register_filesystem(&fuseblk_fs_type);
1702 static inline void unregister_fuseblk(void)
1704 unregister_filesystem(&fuseblk_fs_type);
1707 static inline int register_fuseblk(void)
1712 static inline void unregister_fuseblk(void)
1717 static void fuse_inode_init_once(void *foo)
1719 struct inode *inode = foo;
1721 inode_init_once(inode);
1724 static int __init fuse_fs_init(void)
1728 fuse_inode_cachep = kmem_cache_create("fuse_inode",
1729 sizeof(struct fuse_inode), 0,
1730 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT|SLAB_RECLAIM_ACCOUNT,
1731 fuse_inode_init_once);
1733 if (!fuse_inode_cachep)
1736 err = register_fuseblk();
1740 err = register_filesystem(&fuse_fs_type);
1747 unregister_fuseblk();
1749 kmem_cache_destroy(fuse_inode_cachep);
1754 static void fuse_fs_cleanup(void)
1756 unregister_filesystem(&fuse_fs_type);
1757 unregister_fuseblk();
1760 * Make sure all delayed rcu free inodes are flushed before we
1764 kmem_cache_destroy(fuse_inode_cachep);
1767 static struct kobject *fuse_kobj;
1769 static int fuse_sysfs_init(void)
1773 fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1779 err = sysfs_create_mount_point(fuse_kobj, "connections");
1781 goto out_fuse_unregister;
1785 out_fuse_unregister:
1786 kobject_put(fuse_kobj);
1791 static void fuse_sysfs_cleanup(void)
1793 sysfs_remove_mount_point(fuse_kobj, "connections");
1794 kobject_put(fuse_kobj);
1797 static int __init fuse_init(void)
1801 pr_info("init (API version %i.%i)\n",
1802 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1804 INIT_LIST_HEAD(&fuse_conn_list);
1805 res = fuse_fs_init();
1809 res = fuse_dev_init();
1811 goto err_fs_cleanup;
1813 res = fuse_sysfs_init();
1815 goto err_dev_cleanup;
1817 res = fuse_ctl_init();
1819 goto err_sysfs_cleanup;
1821 sanitize_global_limit(&max_user_bgreq);
1822 sanitize_global_limit(&max_user_congthresh);
1827 fuse_sysfs_cleanup();
1836 static void __exit fuse_exit(void)
1841 fuse_sysfs_cleanup();
1846 module_init(fuse_init);
1847 module_exit(fuse_exit);