| /* |
| FUSE: Filesystem in Userspace |
| Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu> |
| |
| This program can be distributed under the terms of the GNU GPL. |
| See the file COPYING. |
| */ |
| |
| #include "fuse_i.h" |
| |
| #include <linux/pagemap.h> |
| #include <linux/slab.h> |
| #include <linux/file.h> |
| #include <linux/seq_file.h> |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/moduleparam.h> |
| #include <linux/fs_context.h> |
| #include <linux/fs_parser.h> |
| #include <linux/statfs.h> |
| #include <linux/random.h> |
| #include <linux/sched.h> |
| #include <linux/exportfs.h> |
| #include <linux/posix_acl.h> |
| #include <linux/pid_namespace.h> |
| |
| MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); |
| MODULE_DESCRIPTION("Filesystem in Userspace"); |
| MODULE_LICENSE("GPL"); |
| |
| static struct kmem_cache *fuse_inode_cachep; |
| struct list_head fuse_conn_list; |
| DEFINE_MUTEX(fuse_mutex); |
| |
| static int set_global_limit(const char *val, const struct kernel_param *kp); |
| |
| unsigned max_user_bgreq; |
| module_param_call(max_user_bgreq, set_global_limit, param_get_uint, |
| &max_user_bgreq, 0644); |
| __MODULE_PARM_TYPE(max_user_bgreq, "uint"); |
| MODULE_PARM_DESC(max_user_bgreq, |
| "Global limit for the maximum number of backgrounded requests an " |
| "unprivileged user can set"); |
| |
| unsigned max_user_congthresh; |
| module_param_call(max_user_congthresh, set_global_limit, param_get_uint, |
| &max_user_congthresh, 0644); |
| __MODULE_PARM_TYPE(max_user_congthresh, "uint"); |
| MODULE_PARM_DESC(max_user_congthresh, |
| "Global limit for the maximum congestion threshold an " |
| "unprivileged user can set"); |
| |
| #define FUSE_SUPER_MAGIC 0x65735546 |
| |
| #define FUSE_DEFAULT_BLKSIZE 512 |
| |
| /** Maximum number of outstanding background requests */ |
| #define FUSE_DEFAULT_MAX_BACKGROUND 12 |
| |
| /** Congestion starts at 75% of maximum */ |
| #define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4) |
| |
| #ifdef CONFIG_BLOCK |
| static struct file_system_type fuseblk_fs_type; |
| #endif |
| |
| struct fuse_forget_link *fuse_alloc_forget(void) |
| { |
| return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL_ACCOUNT); |
| } |
| |
| static struct inode *fuse_alloc_inode(struct super_block *sb) |
| { |
| struct fuse_inode *fi; |
| |
| fi = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL); |
| if (!fi) |
| return NULL; |
| |
| fi->i_time = 0; |
| fi->inval_mask = 0; |
| fi->nodeid = 0; |
| fi->nlookup = 0; |
| fi->attr_version = 0; |
| fi->orig_ino = 0; |
| fi->state = 0; |
| mutex_init(&fi->mutex); |
| spin_lock_init(&fi->lock); |
| fi->forget = fuse_alloc_forget(); |
| if (!fi->forget) |
| goto out_free; |
| |
| if (IS_ENABLED(CONFIG_FUSE_DAX) && !fuse_dax_inode_alloc(sb, fi)) |
| goto out_free_forget; |
| |
| return &fi->inode; |
| |
| out_free_forget: |
| kfree(fi->forget); |
| out_free: |
| kmem_cache_free(fuse_inode_cachep, fi); |
| return NULL; |
| } |
| |
| static void fuse_free_inode(struct inode *inode) |
| { |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| |
| mutex_destroy(&fi->mutex); |
| kfree(fi->forget); |
| #ifdef CONFIG_FUSE_DAX |
| kfree(fi->dax); |
| #endif |
| kmem_cache_free(fuse_inode_cachep, fi); |
| } |
| |
| static void fuse_evict_inode(struct inode *inode) |
| { |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| |
| truncate_inode_pages_final(&inode->i_data); |
| clear_inode(inode); |
| if (inode->i_sb->s_flags & SB_ACTIVE) { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| |
| if (FUSE_IS_DAX(inode)) |
| fuse_dax_inode_cleanup(inode); |
| if (fi->nlookup) { |
| fuse_queue_forget(fc, fi->forget, fi->nodeid, |
| fi->nlookup); |
| fi->forget = NULL; |
| } |
| } |
| if (S_ISREG(inode->i_mode) && !fuse_is_bad(inode)) { |
| WARN_ON(!list_empty(&fi->write_files)); |
| WARN_ON(!list_empty(&fi->queued_writes)); |
| } |
| } |
| |
| static int fuse_reconfigure(struct fs_context *fsc) |
| { |
| struct super_block *sb = fsc->root->d_sb; |
| |
| sync_filesystem(sb); |
| if (fsc->sb_flags & SB_MANDLOCK) |
| return -EINVAL; |
| |
| return 0; |
| } |
| |
| /* |
| * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down |
| * so that it will fit. |
| */ |
| static ino_t fuse_squash_ino(u64 ino64) |
| { |
| ino_t ino = (ino_t) ino64; |
| if (sizeof(ino_t) < sizeof(u64)) |
| ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8; |
| return ino; |
| } |
| |
| void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr, |
| u64 attr_valid) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| |
| lockdep_assert_held(&fi->lock); |
| |
| fi->attr_version = atomic64_inc_return(&fc->attr_version); |
| fi->i_time = attr_valid; |
| WRITE_ONCE(fi->inval_mask, 0); |
| |
| inode->i_ino = fuse_squash_ino(attr->ino); |
| inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777); |
| set_nlink(inode, attr->nlink); |
| inode->i_uid = make_kuid(fc->user_ns, attr->uid); |
| inode->i_gid = make_kgid(fc->user_ns, attr->gid); |
| inode->i_blocks = attr->blocks; |
| inode->i_atime.tv_sec = attr->atime; |
| inode->i_atime.tv_nsec = attr->atimensec; |
| /* mtime from server may be stale due to local buffered write */ |
| if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) { |
| inode->i_mtime.tv_sec = attr->mtime; |
| inode->i_mtime.tv_nsec = attr->mtimensec; |
| inode->i_ctime.tv_sec = attr->ctime; |
| inode->i_ctime.tv_nsec = attr->ctimensec; |
| } |
| |
| if (attr->blksize != 0) |
| inode->i_blkbits = ilog2(attr->blksize); |
| else |
| inode->i_blkbits = inode->i_sb->s_blocksize_bits; |
| |
| /* |
| * Don't set the sticky bit in i_mode, unless we want the VFS |
| * to check permissions. This prevents failures due to the |
| * check in may_delete(). |
| */ |
| fi->orig_i_mode = inode->i_mode; |
| if (!fc->default_permissions) |
| inode->i_mode &= ~S_ISVTX; |
| |
| fi->orig_ino = attr->ino; |
| |
| /* |
| * We are refreshing inode data and it is possible that another |
| * client set suid/sgid or security.capability xattr. So clear |
| * S_NOSEC. Ideally, we could have cleared it only if suid/sgid |
| * was set or if security.capability xattr was set. But we don't |
| * know if security.capability has been set or not. So clear it |
| * anyway. Its less efficient but should be safe. |
| */ |
| inode->i_flags &= ~S_NOSEC; |
| } |
| |
| void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, |
| u64 attr_valid, u64 attr_version) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| bool is_wb = fc->writeback_cache; |
| loff_t oldsize; |
| struct timespec64 old_mtime; |
| |
| spin_lock(&fi->lock); |
| if ((attr_version != 0 && fi->attr_version > attr_version) || |
| test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) { |
| spin_unlock(&fi->lock); |
| return; |
| } |
| |
| old_mtime = inode->i_mtime; |
| fuse_change_attributes_common(inode, attr, attr_valid); |
| |
| oldsize = inode->i_size; |
| /* |
| * In case of writeback_cache enabled, the cached writes beyond EOF |
| * extend local i_size without keeping userspace server in sync. So, |
| * attr->size coming from server can be stale. We cannot trust it. |
| */ |
| if (!is_wb || !S_ISREG(inode->i_mode)) |
| i_size_write(inode, attr->size); |
| spin_unlock(&fi->lock); |
| |
| if (!is_wb && S_ISREG(inode->i_mode)) { |
| bool inval = false; |
| |
| if (oldsize != attr->size) { |
| truncate_pagecache(inode, attr->size); |
| if (!fc->explicit_inval_data) |
| inval = true; |
| } else if (fc->auto_inval_data) { |
| struct timespec64 new_mtime = { |
| .tv_sec = attr->mtime, |
| .tv_nsec = attr->mtimensec, |
| }; |
| |
| /* |
| * Auto inval mode also checks and invalidates if mtime |
| * has changed. |
| */ |
| if (!timespec64_equal(&old_mtime, &new_mtime)) |
| inval = true; |
| } |
| |
| if (inval) |
| invalidate_inode_pages2(inode->i_mapping); |
| } |
| } |
| |
| static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr) |
| { |
| inode->i_mode = attr->mode & S_IFMT; |
| inode->i_size = attr->size; |
| inode->i_mtime.tv_sec = attr->mtime; |
| inode->i_mtime.tv_nsec = attr->mtimensec; |
| inode->i_ctime.tv_sec = attr->ctime; |
| inode->i_ctime.tv_nsec = attr->ctimensec; |
| if (S_ISREG(inode->i_mode)) { |
| fuse_init_common(inode); |
| fuse_init_file_inode(inode); |
| } else if (S_ISDIR(inode->i_mode)) |
| fuse_init_dir(inode); |
| else if (S_ISLNK(inode->i_mode)) |
| fuse_init_symlink(inode); |
| else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || |
| S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { |
| fuse_init_common(inode); |
| init_special_inode(inode, inode->i_mode, |
| new_decode_dev(attr->rdev)); |
| } else |
| BUG(); |
| } |
| |
| static int fuse_inode_eq(struct inode *inode, void *_nodeidp) |
| { |
| u64 nodeid = *(u64 *) _nodeidp; |
| if (get_node_id(inode) == nodeid) |
| return 1; |
| else |
| return 0; |
| } |
| |
| static int fuse_inode_set(struct inode *inode, void *_nodeidp) |
| { |
| u64 nodeid = *(u64 *) _nodeidp; |
| get_fuse_inode(inode)->nodeid = nodeid; |
| return 0; |
| } |
| |
| struct inode *fuse_iget(struct super_block *sb, u64 nodeid, |
| int generation, struct fuse_attr *attr, |
| u64 attr_valid, u64 attr_version) |
| { |
| struct inode *inode; |
| struct fuse_inode *fi; |
| struct fuse_conn *fc = get_fuse_conn_super(sb); |
| |
| /* |
| * Auto mount points get their node id from the submount root, which is |
| * not a unique identifier within this filesystem. |
| * |
| * To avoid conflicts, do not place submount points into the inode hash |
| * table. |
| */ |
| if (fc->auto_submounts && (attr->flags & FUSE_ATTR_SUBMOUNT) && |
| S_ISDIR(attr->mode)) { |
| inode = new_inode(sb); |
| if (!inode) |
| return NULL; |
| |
| fuse_init_inode(inode, attr); |
| get_fuse_inode(inode)->nodeid = nodeid; |
| inode->i_flags |= S_AUTOMOUNT; |
| goto done; |
| } |
| |
| retry: |
| inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid); |
| if (!inode) |
| return NULL; |
| |
| if ((inode->i_state & I_NEW)) { |
| inode->i_flags |= S_NOATIME; |
| if (!fc->writeback_cache || !S_ISREG(attr->mode)) |
| inode->i_flags |= S_NOCMTIME; |
| inode->i_generation = generation; |
| fuse_init_inode(inode, attr); |
| unlock_new_inode(inode); |
| } else if (fuse_stale_inode(inode, generation, attr)) { |
| /* nodeid was reused, any I/O on the old inode should fail */ |
| fuse_make_bad(inode); |
| iput(inode); |
| goto retry; |
| } |
| done: |
| fi = get_fuse_inode(inode); |
| spin_lock(&fi->lock); |
| fi->nlookup++; |
| spin_unlock(&fi->lock); |
| fuse_change_attributes(inode, attr, attr_valid, attr_version); |
| |
| return inode; |
| } |
| |
| struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid, |
| struct fuse_mount **fm) |
| { |
| struct fuse_mount *fm_iter; |
| struct inode *inode; |
| |
| WARN_ON(!rwsem_is_locked(&fc->killsb)); |
| list_for_each_entry(fm_iter, &fc->mounts, fc_entry) { |
| if (!fm_iter->sb) |
| continue; |
| |
| inode = ilookup5(fm_iter->sb, nodeid, fuse_inode_eq, &nodeid); |
| if (inode) { |
| if (fm) |
| *fm = fm_iter; |
| return inode; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid, |
| loff_t offset, loff_t len) |
| { |
| struct fuse_inode *fi; |
| struct inode *inode; |
| pgoff_t pg_start; |
| pgoff_t pg_end; |
| |
| inode = fuse_ilookup(fc, nodeid, NULL); |
| if (!inode) |
| return -ENOENT; |
| |
| fi = get_fuse_inode(inode); |
| spin_lock(&fi->lock); |
| fi->attr_version = atomic64_inc_return(&fc->attr_version); |
| spin_unlock(&fi->lock); |
| |
| fuse_invalidate_attr(inode); |
| forget_all_cached_acls(inode); |
| if (offset >= 0) { |
| pg_start = offset >> PAGE_SHIFT; |
| if (len <= 0) |
| pg_end = -1; |
| else |
| pg_end = (offset + len - 1) >> PAGE_SHIFT; |
| invalidate_inode_pages2_range(inode->i_mapping, |
| pg_start, pg_end); |
| } |
| iput(inode); |
| return 0; |
| } |
| |
| bool fuse_lock_inode(struct inode *inode) |
| { |
| bool locked = false; |
| |
| if (!get_fuse_conn(inode)->parallel_dirops) { |
| mutex_lock(&get_fuse_inode(inode)->mutex); |
| locked = true; |
| } |
| |
| return locked; |
| } |
| |
| void fuse_unlock_inode(struct inode *inode, bool locked) |
| { |
| if (locked) |
| mutex_unlock(&get_fuse_inode(inode)->mutex); |
| } |
| |
| static void fuse_umount_begin(struct super_block *sb) |
| { |
| struct fuse_conn *fc = get_fuse_conn_super(sb); |
| |
| if (!fc->no_force_umount) |
| fuse_abort_conn(fc); |
| } |
| |
| static void fuse_send_destroy(struct fuse_mount *fm) |
| { |
| if (fm->fc->conn_init) { |
| FUSE_ARGS(args); |
| |
| args.opcode = FUSE_DESTROY; |
| args.force = true; |
| args.nocreds = true; |
| fuse_simple_request(fm, &args); |
| } |
| } |
| |
| static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr) |
| { |
| stbuf->f_type = FUSE_SUPER_MAGIC; |
| stbuf->f_bsize = attr->bsize; |
| stbuf->f_frsize = attr->frsize; |
| stbuf->f_blocks = attr->blocks; |
| stbuf->f_bfree = attr->bfree; |
| stbuf->f_bavail = attr->bavail; |
| stbuf->f_files = attr->files; |
| stbuf->f_ffree = attr->ffree; |
| stbuf->f_namelen = attr->namelen; |
| /* fsid is left zero */ |
| } |
| |
| static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf) |
| { |
| struct super_block *sb = dentry->d_sb; |
| struct fuse_mount *fm = get_fuse_mount_super(sb); |
| FUSE_ARGS(args); |
| struct fuse_statfs_out outarg; |
| int err; |
| |
| if (!fuse_allow_current_process(fm->fc)) { |
| buf->f_type = FUSE_SUPER_MAGIC; |
| return 0; |
| } |
| |
| memset(&outarg, 0, sizeof(outarg)); |
| args.in_numargs = 0; |
| args.opcode = FUSE_STATFS; |
| args.nodeid = get_node_id(d_inode(dentry)); |
| args.out_numargs = 1; |
| args.out_args[0].size = sizeof(outarg); |
| args.out_args[0].value = &outarg; |
| err = fuse_simple_request(fm, &args); |
| if (!err) |
| convert_fuse_statfs(buf, &outarg.st); |
| return err; |
| } |
| |
| static struct fuse_sync_bucket *fuse_sync_bucket_alloc(void) |
| { |
| struct fuse_sync_bucket *bucket; |
| |
| bucket = kzalloc(sizeof(*bucket), GFP_KERNEL | __GFP_NOFAIL); |
| if (bucket) { |
| init_waitqueue_head(&bucket->waitq); |
| /* Initial active count */ |
| atomic_set(&bucket->count, 1); |
| } |
| return bucket; |
| } |
| |
| static void fuse_sync_fs_writes(struct fuse_conn *fc) |
| { |
| struct fuse_sync_bucket *bucket, *new_bucket; |
| int count; |
| |
| new_bucket = fuse_sync_bucket_alloc(); |
| spin_lock(&fc->lock); |
| bucket = rcu_dereference_protected(fc->curr_bucket, 1); |
| count = atomic_read(&bucket->count); |
| WARN_ON(count < 1); |
| /* No outstanding writes? */ |
| if (count == 1) { |
| spin_unlock(&fc->lock); |
| kfree(new_bucket); |
| return; |
| } |
| |
| /* |
| * Completion of new bucket depends on completion of this bucket, so add |
| * one more count. |
| */ |
| atomic_inc(&new_bucket->count); |
| rcu_assign_pointer(fc->curr_bucket, new_bucket); |
| spin_unlock(&fc->lock); |
| /* |
| * Drop initial active count. At this point if all writes in this and |
| * ancestor buckets complete, the count will go to zero and this task |
| * will be woken up. |
| */ |
| atomic_dec(&bucket->count); |
| |
| wait_event(bucket->waitq, atomic_read(&bucket->count) == 0); |
| |
| /* Drop temp count on descendant bucket */ |
| fuse_sync_bucket_dec(new_bucket); |
| kfree_rcu(bucket, rcu); |
| } |
| |
| static int fuse_sync_fs(struct super_block *sb, int wait) |
| { |
| struct fuse_mount *fm = get_fuse_mount_super(sb); |
| struct fuse_conn *fc = fm->fc; |
| struct fuse_syncfs_in inarg; |
| FUSE_ARGS(args); |
| int err; |
| |
| /* |
| * Userspace cannot handle the wait == 0 case. Avoid a |
| * gratuitous roundtrip. |
| */ |
| if (!wait) |
| return 0; |
| |
| /* The filesystem is being unmounted. Nothing to do. */ |
| if (!sb->s_root) |
| return 0; |
| |
| if (!fc->sync_fs) |
| return 0; |
| |
| fuse_sync_fs_writes(fc); |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| args.in_numargs = 1; |
| args.in_args[0].size = sizeof(inarg); |
| args.in_args[0].value = &inarg; |
| args.opcode = FUSE_SYNCFS; |
| args.nodeid = get_node_id(sb->s_root->d_inode); |
| args.out_numargs = 0; |
| |
| err = fuse_simple_request(fm, &args); |
| if (err == -ENOSYS) { |
| fc->sync_fs = 0; |
| err = 0; |
| } |
| |
| return err; |
| } |
| |
| enum { |
| OPT_SOURCE, |
| OPT_SUBTYPE, |
| OPT_FD, |
| OPT_ROOTMODE, |
| OPT_USER_ID, |
| OPT_GROUP_ID, |
| OPT_DEFAULT_PERMISSIONS, |
| OPT_ALLOW_OTHER, |
| OPT_MAX_READ, |
| OPT_BLKSIZE, |
| OPT_ERR |
| }; |
| |
| static const struct fs_parameter_spec fuse_fs_parameters[] = { |
| fsparam_string ("source", OPT_SOURCE), |
| fsparam_u32 ("fd", OPT_FD), |
| fsparam_u32oct ("rootmode", OPT_ROOTMODE), |
| fsparam_u32 ("user_id", OPT_USER_ID), |
| fsparam_u32 ("group_id", OPT_GROUP_ID), |
| fsparam_flag ("default_permissions", OPT_DEFAULT_PERMISSIONS), |
| fsparam_flag ("allow_other", OPT_ALLOW_OTHER), |
| fsparam_u32 ("max_read", OPT_MAX_READ), |
| fsparam_u32 ("blksize", OPT_BLKSIZE), |
| fsparam_string ("subtype", OPT_SUBTYPE), |
| {} |
| }; |
| |
| static int fuse_parse_param(struct fs_context *fsc, struct fs_parameter *param) |
| { |
| struct fs_parse_result result; |
| struct fuse_fs_context *ctx = fsc->fs_private; |
| int opt; |
| |
| if (fsc->purpose == FS_CONTEXT_FOR_RECONFIGURE) { |
| /* |
| * Ignore options coming from mount(MS_REMOUNT) for backward |
| * compatibility. |
| */ |
| if (fsc->oldapi) |
| return 0; |
| |
| return invalfc(fsc, "No changes allowed in reconfigure"); |
| } |
| |
| opt = fs_parse(fsc, fuse_fs_parameters, param, &result); |
| if (opt < 0) |
| return opt; |
| |
| switch (opt) { |
| case OPT_SOURCE: |
| if (fsc->source) |
| return invalfc(fsc, "Multiple sources specified"); |
| fsc->source = param->string; |
| param->string = NULL; |
| break; |
| |
| case OPT_SUBTYPE: |
| if (ctx->subtype) |
| return invalfc(fsc, "Multiple subtypes specified"); |
| ctx->subtype = param->string; |
| param->string = NULL; |
| return 0; |
| |
| case OPT_FD: |
| ctx->fd = result.uint_32; |
| ctx->fd_present = true; |
| break; |
| |
| case OPT_ROOTMODE: |
| if (!fuse_valid_type(result.uint_32)) |
| return invalfc(fsc, "Invalid rootmode"); |
| ctx->rootmode = result.uint_32; |
| ctx->rootmode_present = true; |
| break; |
| |
| case OPT_USER_ID: |
| ctx->user_id = make_kuid(fsc->user_ns, result.uint_32); |
| if (!uid_valid(ctx->user_id)) |
| return invalfc(fsc, "Invalid user_id"); |
| ctx->user_id_present = true; |
| break; |
| |
| case OPT_GROUP_ID: |
| ctx->group_id = make_kgid(fsc->user_ns, result.uint_32); |
| if (!gid_valid(ctx->group_id)) |
| return invalfc(fsc, "Invalid group_id"); |
| ctx->group_id_present = true; |
| break; |
| |
| case OPT_DEFAULT_PERMISSIONS: |
| ctx->default_permissions = true; |
| break; |
| |
| case OPT_ALLOW_OTHER: |
| ctx->allow_other = true; |
| break; |
| |
| case OPT_MAX_READ: |
| ctx->max_read = result.uint_32; |
| break; |
| |
| case OPT_BLKSIZE: |
| if (!ctx->is_bdev) |
| return invalfc(fsc, "blksize only supported for fuseblk"); |
| ctx->blksize = result.uint_32; |
| break; |
| |
| default: |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static void fuse_free_fsc(struct fs_context *fsc) |
| { |
| struct fuse_fs_context *ctx = fsc->fs_private; |
| |
| if (ctx) { |
| kfree(ctx->subtype); |
| kfree(ctx); |
| } |
| } |
| |
| static int fuse_show_options(struct seq_file *m, struct dentry *root) |
| { |
| struct super_block *sb = root->d_sb; |
| struct fuse_conn *fc = get_fuse_conn_super(sb); |
| |
| if (fc->legacy_opts_show) { |
| seq_printf(m, ",user_id=%u", |
| from_kuid_munged(fc->user_ns, fc->user_id)); |
| seq_printf(m, ",group_id=%u", |
| from_kgid_munged(fc->user_ns, fc->group_id)); |
| if (fc->default_permissions) |
| seq_puts(m, ",default_permissions"); |
| if (fc->allow_other) |
| seq_puts(m, ",allow_other"); |
| if (fc->max_read != ~0) |
| seq_printf(m, ",max_read=%u", fc->max_read); |
| if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE) |
| seq_printf(m, ",blksize=%lu", sb->s_blocksize); |
| } |
| #ifdef CONFIG_FUSE_DAX |
| if (fc->dax) |
| seq_puts(m, ",dax"); |
| #endif |
| |
| return 0; |
| } |
| |
| static void fuse_iqueue_init(struct fuse_iqueue *fiq, |
| const struct fuse_iqueue_ops *ops, |
| void *priv) |
| { |
| memset(fiq, 0, sizeof(struct fuse_iqueue)); |
| spin_lock_init(&fiq->lock); |
| init_waitqueue_head(&fiq->waitq); |
| INIT_LIST_HEAD(&fiq->pending); |
| INIT_LIST_HEAD(&fiq->interrupts); |
| fiq->forget_list_tail = &fiq->forget_list_head; |
| fiq->connected = 1; |
| fiq->ops = ops; |
| fiq->priv = priv; |
| } |
| |
| static void fuse_pqueue_init(struct fuse_pqueue *fpq) |
| { |
| unsigned int i; |
| |
| spin_lock_init(&fpq->lock); |
| for (i = 0; i < FUSE_PQ_HASH_SIZE; i++) |
| INIT_LIST_HEAD(&fpq->processing[i]); |
| INIT_LIST_HEAD(&fpq->io); |
| fpq->connected = 1; |
| } |
| |
| void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm, |
| struct user_namespace *user_ns, |
| const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv) |
| { |
| memset(fc, 0, sizeof(*fc)); |
| spin_lock_init(&fc->lock); |
| spin_lock_init(&fc->bg_lock); |
| init_rwsem(&fc->killsb); |
| refcount_set(&fc->count, 1); |
| atomic_set(&fc->dev_count, 1); |
| init_waitqueue_head(&fc->blocked_waitq); |
| fuse_iqueue_init(&fc->iq, fiq_ops, fiq_priv); |
| INIT_LIST_HEAD(&fc->bg_queue); |
| INIT_LIST_HEAD(&fc->entry); |
| INIT_LIST_HEAD(&fc->devices); |
| atomic_set(&fc->num_waiting, 0); |
| fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND; |
| fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD; |
| atomic64_set(&fc->khctr, 0); |
| fc->polled_files = RB_ROOT; |
| fc->blocked = 0; |
| fc->initialized = 0; |
| fc->connected = 1; |
| atomic64_set(&fc->attr_version, 1); |
| get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key)); |
| fc->pid_ns = get_pid_ns(task_active_pid_ns(current)); |
| fc->user_ns = get_user_ns(user_ns); |
| fc->max_pages = FUSE_DEFAULT_MAX_PAGES_PER_REQ; |
| fc->max_pages_limit = FUSE_MAX_MAX_PAGES; |
| |
| INIT_LIST_HEAD(&fc->mounts); |
| list_add(&fm->fc_entry, &fc->mounts); |
| fm->fc = fc; |
| } |
| EXPORT_SYMBOL_GPL(fuse_conn_init); |
| |
| void fuse_conn_put(struct fuse_conn *fc) |
| { |
| if (refcount_dec_and_test(&fc->count)) { |
| struct fuse_iqueue *fiq = &fc->iq; |
| struct fuse_sync_bucket *bucket; |
| |
| if (IS_ENABLED(CONFIG_FUSE_DAX)) |
| fuse_dax_conn_free(fc); |
| if (fiq->ops->release) |
| fiq->ops->release(fiq); |
| put_pid_ns(fc->pid_ns); |
| put_user_ns(fc->user_ns); |
| bucket = rcu_dereference_protected(fc->curr_bucket, 1); |
| if (bucket) { |
| WARN_ON(atomic_read(&bucket->count) != 1); |
| kfree(bucket); |
| } |
| fc->release(fc); |
| } |
| } |
| EXPORT_SYMBOL_GPL(fuse_conn_put); |
| |
| struct fuse_conn *fuse_conn_get(struct fuse_conn *fc) |
| { |
| refcount_inc(&fc->count); |
| return fc; |
| } |
| EXPORT_SYMBOL_GPL(fuse_conn_get); |
| |
| static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode) |
| { |
| struct fuse_attr attr; |
| memset(&attr, 0, sizeof(attr)); |
| |
| attr.mode = mode; |
| attr.ino = FUSE_ROOT_ID; |
| attr.nlink = 1; |
| return fuse_iget(sb, 1, 0, &attr, 0, 0); |
| } |
| |
| struct fuse_inode_handle { |
| u64 nodeid; |
| u32 generation; |
| }; |
| |
| static struct dentry *fuse_get_dentry(struct super_block *sb, |
| struct fuse_inode_handle *handle) |
| { |
| struct fuse_conn *fc = get_fuse_conn_super(sb); |
| struct inode *inode; |
| struct dentry *entry; |
| int err = -ESTALE; |
| |
| if (handle->nodeid == 0) |
| goto out_err; |
| |
| inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid); |
| if (!inode) { |
| struct fuse_entry_out outarg; |
| const struct qstr name = QSTR_INIT(".", 1); |
| |
| if (!fc->export_support) |
| goto out_err; |
| |
| err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg, |
| &inode); |
| if (err && err != -ENOENT) |
| goto out_err; |
| if (err || !inode) { |
| err = -ESTALE; |
| goto out_err; |
| } |
| err = -EIO; |
| if (get_node_id(inode) != handle->nodeid) |
| goto out_iput; |
| } |
| err = -ESTALE; |
| if (inode->i_generation != handle->generation) |
| goto out_iput; |
| |
| entry = d_obtain_alias(inode); |
| if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) |
| fuse_invalidate_entry_cache(entry); |
| |
| return entry; |
| |
| out_iput: |
| iput(inode); |
| out_err: |
| return ERR_PTR(err); |
| } |
| |
| static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len, |
| struct inode *parent) |
| { |
| int len = parent ? 6 : 3; |
| u64 nodeid; |
| u32 generation; |
| |
| if (*max_len < len) { |
| *max_len = len; |
| return FILEID_INVALID; |
| } |
| |
| nodeid = get_fuse_inode(inode)->nodeid; |
| generation = inode->i_generation; |
| |
| fh[0] = (u32)(nodeid >> 32); |
| fh[1] = (u32)(nodeid & 0xffffffff); |
| fh[2] = generation; |
| |
| if (parent) { |
| nodeid = get_fuse_inode(parent)->nodeid; |
| generation = parent->i_generation; |
| |
| fh[3] = (u32)(nodeid >> 32); |
| fh[4] = (u32)(nodeid & 0xffffffff); |
| fh[5] = generation; |
| } |
| |
| *max_len = len; |
| return parent ? 0x82 : 0x81; |
| } |
| |
| static struct dentry *fuse_fh_to_dentry(struct super_block *sb, |
| struct fid *fid, int fh_len, int fh_type) |
| { |
| struct fuse_inode_handle handle; |
| |
| if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3) |
| return NULL; |
| |
| handle.nodeid = (u64) fid->raw[0] << 32; |
| handle.nodeid |= (u64) fid->raw[1]; |
| handle.generation = fid->raw[2]; |
| return fuse_get_dentry(sb, &handle); |
| } |
| |
| static struct dentry *fuse_fh_to_parent(struct super_block *sb, |
| struct fid *fid, int fh_len, int fh_type) |
| { |
| struct fuse_inode_handle parent; |
| |
| if (fh_type != 0x82 || fh_len < 6) |
| return NULL; |
| |
| parent.nodeid = (u64) fid->raw[3] << 32; |
| parent.nodeid |= (u64) fid->raw[4]; |
| parent.generation = fid->raw[5]; |
| return fuse_get_dentry(sb, &parent); |
| } |
| |
| static struct dentry *fuse_get_parent(struct dentry *child) |
| { |
| struct inode *child_inode = d_inode(child); |
| struct fuse_conn *fc = get_fuse_conn(child_inode); |
| struct inode *inode; |
| struct dentry *parent; |
| struct fuse_entry_out outarg; |
| int err; |
| |
| if (!fc->export_support) |
| return ERR_PTR(-ESTALE); |
| |
| err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode), |
| &dotdot_name, &outarg, &inode); |
| if (err) { |
| if (err == -ENOENT) |
| return ERR_PTR(-ESTALE); |
| return ERR_PTR(err); |
| } |
| |
| parent = d_obtain_alias(inode); |
| if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) |
| fuse_invalidate_entry_cache(parent); |
| |
| return parent; |
| } |
| |
| static const struct export_operations fuse_export_operations = { |
| .fh_to_dentry = fuse_fh_to_dentry, |
| .fh_to_parent = fuse_fh_to_parent, |
| .encode_fh = fuse_encode_fh, |
| .get_parent = fuse_get_parent, |
| }; |
| |
| static const struct super_operations fuse_super_operations = { |
| .alloc_inode = fuse_alloc_inode, |
| .free_inode = fuse_free_inode, |
| .evict_inode = fuse_evict_inode, |
| .write_inode = fuse_write_inode, |
| .drop_inode = generic_delete_inode, |
| .umount_begin = fuse_umount_begin, |
| .statfs = fuse_statfs, |
| .sync_fs = fuse_sync_fs, |
| .show_options = fuse_show_options, |
| }; |
| |
| static void sanitize_global_limit(unsigned *limit) |
| { |
| /* |
| * The default maximum number of async requests is calculated to consume |
| * 1/2^13 of the total memory, assuming 392 bytes per request. |
| */ |
| if (*limit == 0) |
| *limit = ((totalram_pages() << PAGE_SHIFT) >> 13) / 392; |
| |
| if (*limit >= 1 << 16) |
| *limit = (1 << 16) - 1; |
| } |
| |
| static int set_global_limit(const char *val, const struct kernel_param *kp) |
| { |
| int rv; |
| |
| rv = param_set_uint(val, kp); |
| if (rv) |
| return rv; |
| |
| sanitize_global_limit((unsigned *)kp->arg); |
| |
| return 0; |
| } |
| |
| static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg) |
| { |
| int cap_sys_admin = capable(CAP_SYS_ADMIN); |
| |
| if (arg->minor < 13) |
| return; |
| |
| sanitize_global_limit(&max_user_bgreq); |
| sanitize_global_limit(&max_user_congthresh); |
| |
| spin_lock(&fc->bg_lock); |
| if (arg->max_background) { |
| fc->max_background = arg->max_background; |
| |
| if (!cap_sys_admin && fc->max_background > max_user_bgreq) |
| fc->max_background = max_user_bgreq; |
| } |
| if (arg->congestion_threshold) { |
| fc->congestion_threshold = arg->congestion_threshold; |
| |
| if (!cap_sys_admin && |
| fc->congestion_threshold > max_user_congthresh) |
| fc->congestion_threshold = max_user_congthresh; |
| } |
| spin_unlock(&fc->bg_lock); |
| } |
| |
| struct fuse_init_args { |
| struct fuse_args args; |
| struct fuse_init_in in; |
| struct fuse_init_out out; |
| }; |
| |
| static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args, |
| int error) |
| { |
| struct fuse_conn *fc = fm->fc; |
| struct fuse_init_args *ia = container_of(args, typeof(*ia), args); |
| struct fuse_init_out *arg = &ia->out; |
| bool ok = true; |
| |
| if (error || arg->major != FUSE_KERNEL_VERSION) |
| ok = false; |
| else { |
| unsigned long ra_pages; |
| |
| process_init_limits(fc, arg); |
| |
| if (arg->minor >= 6) { |
| ra_pages = arg->max_readahead / PAGE_SIZE; |
| if (arg->flags & FUSE_ASYNC_READ) |
| fc->async_read = 1; |
| if (!(arg->flags & FUSE_POSIX_LOCKS)) |
| fc->no_lock = 1; |
| if (arg->minor >= 17) { |
| if (!(arg->flags & FUSE_FLOCK_LOCKS)) |
| fc->no_flock = 1; |
| } else { |
| if (!(arg->flags & FUSE_POSIX_LOCKS)) |
| fc->no_flock = 1; |
| } |
| if (arg->flags & FUSE_ATOMIC_O_TRUNC) |
| fc->atomic_o_trunc = 1; |
| if (arg->minor >= 9) { |
| /* LOOKUP has dependency on proto version */ |
| if (arg->flags & FUSE_EXPORT_SUPPORT) |
| fc->export_support = 1; |
| } |
| if (arg->flags & FUSE_BIG_WRITES) |
| fc->big_writes = 1; |
| if (arg->flags & FUSE_DONT_MASK) |
| fc->dont_mask = 1; |
| if (arg->flags & FUSE_AUTO_INVAL_DATA) |
| fc->auto_inval_data = 1; |
| else if (arg->flags & FUSE_EXPLICIT_INVAL_DATA) |
| fc->explicit_inval_data = 1; |
| if (arg->flags & FUSE_DO_READDIRPLUS) { |
| fc->do_readdirplus = 1; |
| if (arg->flags & FUSE_READDIRPLUS_AUTO) |
| fc->readdirplus_auto = 1; |
| } |
| if (arg->flags & FUSE_ASYNC_DIO) |
| fc->async_dio = 1; |
| if (arg->flags & FUSE_WRITEBACK_CACHE) |
| fc->writeback_cache = 1; |
| if (arg->flags & FUSE_PARALLEL_DIROPS) |
| fc->parallel_dirops = 1; |
| if (arg->flags & FUSE_HANDLE_KILLPRIV) |
| fc->handle_killpriv = 1; |
| if (arg->time_gran && arg->time_gran <= 1000000000) |
| fm->sb->s_time_gran = arg->time_gran; |
| if ((arg->flags & FUSE_POSIX_ACL)) { |
| fc->default_permissions = 1; |
| fc->posix_acl = 1; |
| fm->sb->s_xattr = fuse_acl_xattr_handlers; |
| } |
| if (arg->flags & FUSE_CACHE_SYMLINKS) |
| fc->cache_symlinks = 1; |
| if (arg->flags & FUSE_ABORT_ERROR) |
| fc->abort_err = 1; |
| if (arg->flags & FUSE_MAX_PAGES) { |
| fc->max_pages = |
| min_t(unsigned int, fc->max_pages_limit, |
| max_t(unsigned int, arg->max_pages, 1)); |
| } |
| if (IS_ENABLED(CONFIG_FUSE_DAX) && |
| arg->flags & FUSE_MAP_ALIGNMENT && |
| !fuse_dax_check_alignment(fc, arg->map_alignment)) { |
| ok = false; |
| } |
| if (arg->flags & FUSE_HANDLE_KILLPRIV_V2) { |
| fc->handle_killpriv_v2 = 1; |
| fm->sb->s_flags |= SB_NOSEC; |
| } |
| if (arg->flags & FUSE_SETXATTR_EXT) |
| fc->setxattr_ext = 1; |
| } else { |
| ra_pages = fc->max_read / PAGE_SIZE; |
| fc->no_lock = 1; |
| fc->no_flock = 1; |
| } |
| |
| fm->sb->s_bdi->ra_pages = |
| min(fm->sb->s_bdi->ra_pages, ra_pages); |
| fc->minor = arg->minor; |
| fc->max_write = arg->minor < 5 ? 4096 : arg->max_write; |
| fc->max_write = max_t(unsigned, 4096, fc->max_write); |
| fc->conn_init = 1; |
| } |
| kfree(ia); |
| |
| if (!ok) { |
| fc->conn_init = 0; |
| fc->conn_error = 1; |
| } |
| |
| fuse_set_initialized(fc); |
| wake_up_all(&fc->blocked_waitq); |
| } |
| |
| void fuse_send_init(struct fuse_mount *fm) |
| { |
| struct fuse_init_args *ia; |
| |
| ia = kzalloc(sizeof(*ia), GFP_KERNEL | __GFP_NOFAIL); |
| |
| ia->in.major = FUSE_KERNEL_VERSION; |
| ia->in.minor = FUSE_KERNEL_MINOR_VERSION; |
| ia->in.max_readahead = fm->sb->s_bdi->ra_pages * PAGE_SIZE; |
| ia->in.flags |= |
| FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC | |
| FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK | |
| FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ | |
| FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA | |
| FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO | |
| FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT | |
| FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL | |
| FUSE_ABORT_ERROR | FUSE_MAX_PAGES | FUSE_CACHE_SYMLINKS | |
| FUSE_NO_OPENDIR_SUPPORT | FUSE_EXPLICIT_INVAL_DATA | |
| FUSE_HANDLE_KILLPRIV_V2 | FUSE_SETXATTR_EXT; |
| #ifdef CONFIG_FUSE_DAX |
| if (fm->fc->dax) |
| ia->in.flags |= FUSE_MAP_ALIGNMENT; |
| #endif |
| if (fm->fc->auto_submounts) |
| ia->in.flags |= FUSE_SUBMOUNTS; |
| |
| ia->args.opcode = FUSE_INIT; |
| ia->args.in_numargs = 1; |
| ia->args.in_args[0].size = sizeof(ia->in); |
| ia->args.in_args[0].value = &ia->in; |
| ia->args.out_numargs = 1; |
| /* Variable length argument used for backward compatibility |
| with interface version < 7.5. Rest of init_out is zeroed |
| by do_get_request(), so a short reply is not a problem */ |
| ia->args.out_argvar = true; |
| ia->args.out_args[0].size = sizeof(ia->out); |
| ia->args.out_args[0].value = &ia->out; |
| ia->args.force = true; |
| ia->args.nocreds = true; |
| ia->args.end = process_init_reply; |
| |
| if (fuse_simple_background(fm, &ia->args, GFP_KERNEL) != 0) |
| process_init_reply(fm, &ia->args, -ENOTCONN); |
| } |
| EXPORT_SYMBOL_GPL(fuse_send_init); |
| |
| void fuse_free_conn(struct fuse_conn *fc) |
| { |
| WARN_ON(!list_empty(&fc->devices)); |
| kfree_rcu(fc, rcu); |
| } |
| EXPORT_SYMBOL_GPL(fuse_free_conn); |
| |
| static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb) |
| { |
| int err; |
| char *suffix = ""; |
| |
| if (sb->s_bdev) { |
| suffix = "-fuseblk"; |
| /* |
| * sb->s_bdi points to blkdev's bdi however we want to redirect |
| * it to our private bdi... |
| */ |
| bdi_put(sb->s_bdi); |
| sb->s_bdi = &noop_backing_dev_info; |
| } |
| err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev), |
| MINOR(fc->dev), suffix); |
| if (err) |
| return err; |
| |
| /* fuse does it's own writeback accounting */ |
| sb->s_bdi->capabilities &= ~BDI_CAP_WRITEBACK_ACCT; |
| sb->s_bdi->capabilities |= BDI_CAP_STRICTLIMIT; |
| |
| /* |
| * For a single fuse filesystem use max 1% of dirty + |
| * writeback threshold. |
| * |
| * This gives about 1M of write buffer for memory maps on a |
| * machine with 1G and 10% dirty_ratio, which should be more |
| * than enough. |
| * |
| * Privileged users can raise it by writing to |
| * |
| * /sys/class/bdi/<bdi>/max_ratio |
| */ |
| bdi_set_max_ratio(sb->s_bdi, 1); |
| |
| return 0; |
| } |
| |
| struct fuse_dev *fuse_dev_alloc(void) |
| { |
| struct fuse_dev *fud; |
| struct list_head *pq; |
| |
| fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL); |
| if (!fud) |
| return NULL; |
| |
| pq = kcalloc(FUSE_PQ_HASH_SIZE, sizeof(struct list_head), GFP_KERNEL); |
| if (!pq) { |
| kfree(fud); |
| return NULL; |
| } |
| |
| fud->pq.processing = pq; |
| fuse_pqueue_init(&fud->pq); |
| |
| return fud; |
| } |
| EXPORT_SYMBOL_GPL(fuse_dev_alloc); |
| |
| void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc) |
| { |
| fud->fc = fuse_conn_get(fc); |
| spin_lock(&fc->lock); |
| list_add_tail(&fud->entry, &fc->devices); |
| spin_unlock(&fc->lock); |
| } |
| EXPORT_SYMBOL_GPL(fuse_dev_install); |
| |
| struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc) |
| { |
| struct fuse_dev *fud; |
| |
| fud = fuse_dev_alloc(); |
| if (!fud) |
| return NULL; |
| |
| fuse_dev_install(fud, fc); |
| return fud; |
| } |
| EXPORT_SYMBOL_GPL(fuse_dev_alloc_install); |
| |
| void fuse_dev_free(struct fuse_dev *fud) |
| { |
| struct fuse_conn *fc = fud->fc; |
| |
| if (fc) { |
| spin_lock(&fc->lock); |
| list_del(&fud->entry); |
| spin_unlock(&fc->lock); |
| |
| fuse_conn_put(fc); |
| } |
| kfree(fud->pq.processing); |
| kfree(fud); |
| } |
| EXPORT_SYMBOL_GPL(fuse_dev_free); |
| |
| static void fuse_fill_attr_from_inode(struct fuse_attr *attr, |
| const struct fuse_inode *fi) |
| { |
| *attr = (struct fuse_attr){ |
| .ino = fi->inode.i_ino, |
| .size = fi->inode.i_size, |
| .blocks = fi->inode.i_blocks, |
| .atime = fi->inode.i_atime.tv_sec, |
| .mtime = fi->inode.i_mtime.tv_sec, |
| .ctime = fi->inode.i_ctime.tv_sec, |
| .atimensec = fi->inode.i_atime.tv_nsec, |
| .mtimensec = fi->inode.i_mtime.tv_nsec, |
| .ctimensec = fi->inode.i_ctime.tv_nsec, |
| .mode = fi->inode.i_mode, |
| .nlink = fi->inode.i_nlink, |
| .uid = fi->inode.i_uid.val, |
| .gid = fi->inode.i_gid.val, |
| .rdev = fi->inode.i_rdev, |
| .blksize = 1u << fi->inode.i_blkbits, |
| }; |
| } |
| |
| static void fuse_sb_defaults(struct super_block *sb) |
| { |
| sb->s_magic = FUSE_SUPER_MAGIC; |
| sb->s_op = &fuse_super_operations; |
| sb->s_xattr = fuse_xattr_handlers; |
| sb->s_maxbytes = MAX_LFS_FILESIZE; |
| sb->s_time_gran = 1; |
| sb->s_export_op = &fuse_export_operations; |
| sb->s_iflags |= SB_I_IMA_UNVERIFIABLE_SIGNATURE; |
| if (sb->s_user_ns != &init_user_ns) |
| sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER; |
| sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION); |
| |
| /* |
| * If we are not in the initial user namespace posix |
| * acls must be translated. |
| */ |
| if (sb->s_user_ns != &init_user_ns) |
| sb->s_xattr = fuse_no_acl_xattr_handlers; |
| } |
| |
| static int fuse_fill_super_submount(struct super_block *sb, |
| struct fuse_inode *parent_fi) |
| { |
| struct fuse_mount *fm = get_fuse_mount_super(sb); |
| struct super_block *parent_sb = parent_fi->inode.i_sb; |
| struct fuse_attr root_attr; |
| struct inode *root; |
| |
| fuse_sb_defaults(sb); |
| fm->sb = sb; |
| |
| WARN_ON(sb->s_bdi != &noop_backing_dev_info); |
| sb->s_bdi = bdi_get(parent_sb->s_bdi); |
| |
| sb->s_xattr = parent_sb->s_xattr; |
| sb->s_time_gran = parent_sb->s_time_gran; |
| sb->s_blocksize = parent_sb->s_blocksize; |
| sb->s_blocksize_bits = parent_sb->s_blocksize_bits; |
| sb->s_subtype = kstrdup(parent_sb->s_subtype, GFP_KERNEL); |
| if (parent_sb->s_subtype && !sb->s_subtype) |
| return -ENOMEM; |
| |
| fuse_fill_attr_from_inode(&root_attr, parent_fi); |
| root = fuse_iget(sb, parent_fi->nodeid, 0, &root_attr, 0, 0); |
| /* |
| * This inode is just a duplicate, so it is not looked up and |
| * its nlookup should not be incremented. fuse_iget() does |
| * that, though, so undo it here. |
| */ |
| get_fuse_inode(root)->nlookup--; |
| sb->s_d_op = &fuse_dentry_operations; |
| sb->s_root = d_make_root(root); |
| if (!sb->s_root) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| |
| /* Filesystem context private data holds the FUSE inode of the mount point */ |
| static int fuse_get_tree_submount(struct fs_context *fsc) |
| { |
| struct fuse_mount *fm; |
| struct fuse_inode *mp_fi = fsc->fs_private; |
| struct fuse_conn *fc = get_fuse_conn(&mp_fi->inode); |
| struct super_block *sb; |
| int err; |
| |
| fm = kzalloc(sizeof(struct fuse_mount), GFP_KERNEL); |
| if (!fm) |
| return -ENOMEM; |
| |
| fm->fc = fuse_conn_get(fc); |
| fsc->s_fs_info = fm; |
| sb = sget_fc(fsc, NULL, set_anon_super_fc); |
| if (fsc->s_fs_info) |
| fuse_mount_destroy(fm); |
| if (IS_ERR(sb)) |
| return PTR_ERR(sb); |
| |
| /* Initialize superblock, making @mp_fi its root */ |
| err = fuse_fill_super_submount(sb, mp_fi); |
| if (err) { |
| deactivate_locked_super(sb); |
| return err; |
| } |
| |
| down_write(&fc->killsb); |
| list_add_tail(&fm->fc_entry, &fc->mounts); |
| up_write(&fc->killsb); |
| |
| sb->s_flags |= SB_ACTIVE; |
| fsc->root = dget(sb->s_root); |
| |
| return 0; |
| } |
| |
| static const struct fs_context_operations fuse_context_submount_ops = { |
| .get_tree = fuse_get_tree_submount, |
| }; |
| |
| int fuse_init_fs_context_submount(struct fs_context *fsc) |
| { |
| fsc->ops = &fuse_context_submount_ops; |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(fuse_init_fs_context_submount); |
| |
| int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx) |
| { |
| struct fuse_dev *fud = NULL; |
| struct fuse_mount *fm = get_fuse_mount_super(sb); |
| struct fuse_conn *fc = fm->fc; |
| struct inode *root; |
| struct dentry *root_dentry; |
| int err; |
| |
| err = -EINVAL; |
| if (sb->s_flags & SB_MANDLOCK) |
| goto err; |
| |
| rcu_assign_pointer(fc->curr_bucket, fuse_sync_bucket_alloc()); |
| fuse_sb_defaults(sb); |
| |
| if (ctx->is_bdev) { |
| #ifdef CONFIG_BLOCK |
| err = -EINVAL; |
| if (!sb_set_blocksize(sb, ctx->blksize)) |
| goto err; |
| #endif |
| } else { |
| sb->s_blocksize = PAGE_SIZE; |
| sb->s_blocksize_bits = PAGE_SHIFT; |
| } |
| |
| sb->s_subtype = ctx->subtype; |
| ctx->subtype = NULL; |
| if (IS_ENABLED(CONFIG_FUSE_DAX)) { |
| err = fuse_dax_conn_alloc(fc, ctx->dax_dev); |
| if (err) |
| goto err; |
| } |
| |
| if (ctx->fudptr) { |
| err = -ENOMEM; |
| fud = fuse_dev_alloc_install(fc); |
| if (!fud) |
| goto err_free_dax; |
| } |
| |
| fc->dev = sb->s_dev; |
| fm->sb = sb; |
| err = fuse_bdi_init(fc, sb); |
| if (err) |
| goto err_dev_free; |
| |
| /* Handle umasking inside the fuse code */ |
| if (sb->s_flags & SB_POSIXACL) |
| fc->dont_mask = 1; |
| sb->s_flags |= SB_POSIXACL; |
| |
| fc->default_permissions = ctx->default_permissions; |
| fc->allow_other = ctx->allow_other; |
| fc->user_id = ctx->user_id; |
| fc->group_id = ctx->group_id; |
| fc->legacy_opts_show = ctx->legacy_opts_show; |
| fc->max_read = max_t(unsigned int, 4096, ctx->max_read); |
| fc->destroy = ctx->destroy; |
| fc->no_control = ctx->no_control; |
| fc->no_force_umount = ctx->no_force_umount; |
| |
| err = -ENOMEM; |
| root = fuse_get_root_inode(sb, ctx->rootmode); |
| sb->s_d_op = &fuse_root_dentry_operations; |
| root_dentry = d_make_root(root); |
| if (!root_dentry) |
| goto err_dev_free; |
| /* Root dentry doesn't have .d_revalidate */ |
| sb->s_d_op = &fuse_dentry_operations; |
| |
| mutex_lock(&fuse_mutex); |
| err = -EINVAL; |
| if (ctx->fudptr && *ctx->fudptr) |
| goto err_unlock; |
| |
| err = fuse_ctl_add_conn(fc); |
| if (err) |
| goto err_unlock; |
| |
| list_add_tail(&fc->entry, &fuse_conn_list); |
| sb->s_root = root_dentry; |
| if (ctx->fudptr) |
| *ctx->fudptr = fud; |
| mutex_unlock(&fuse_mutex); |
| return 0; |
| |
| err_unlock: |
| mutex_unlock(&fuse_mutex); |
| dput(root_dentry); |
| err_dev_free: |
| if (fud) |
| fuse_dev_free(fud); |
| err_free_dax: |
| if (IS_ENABLED(CONFIG_FUSE_DAX)) |
| fuse_dax_conn_free(fc); |
| err: |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(fuse_fill_super_common); |
| |
| static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc) |
| { |
| struct fuse_fs_context *ctx = fsc->fs_private; |
| int err; |
| |
| if (!ctx->file || !ctx->rootmode_present || |
| !ctx->user_id_present || !ctx->group_id_present) |
| return -EINVAL; |
| |
| /* |
| * Require mount to happen from the same user namespace which |
| * opened /dev/fuse to prevent potential attacks. |
| */ |
| if ((ctx->file->f_op != &fuse_dev_operations) || |
| (ctx->file->f_cred->user_ns != sb->s_user_ns)) |
| return -EINVAL; |
| ctx->fudptr = &ctx->file->private_data; |
| |
| err = fuse_fill_super_common(sb, ctx); |
| if (err) |
| return err; |
| /* file->private_data shall be visible on all CPUs after this */ |
| smp_mb(); |
| fuse_send_init(get_fuse_mount_super(sb)); |
| return 0; |
| } |
| |
| /* |
| * This is the path where user supplied an already initialized fuse dev. In |
| * this case never create a new super if the old one is gone. |
| */ |
| static int fuse_set_no_super(struct super_block *sb, struct fs_context *fsc) |
| { |
| return -ENOTCONN; |
| } |
| |
| static int fuse_test_super(struct super_block *sb, struct fs_context *fsc) |
| { |
| |
| return fsc->sget_key == get_fuse_conn_super(sb); |
| } |
| |
| static int fuse_get_tree(struct fs_context *fsc) |
| { |
| struct fuse_fs_context *ctx = fsc->fs_private; |
| struct fuse_dev *fud; |
| struct fuse_conn *fc; |
| struct fuse_mount *fm; |
| struct super_block *sb; |
| int err; |
| |
| fc = kmalloc(sizeof(*fc), GFP_KERNEL); |
| if (!fc) |
| return -ENOMEM; |
| |
| fm = kzalloc(sizeof(*fm), GFP_KERNEL); |
| if (!fm) { |
| kfree(fc); |
| return -ENOMEM; |
| } |
| |
| fuse_conn_init(fc, fm, fsc->user_ns, &fuse_dev_fiq_ops, NULL); |
| fc->release = fuse_free_conn; |
| |
| fsc->s_fs_info = fm; |
| |
| if (ctx->fd_present) |
| ctx->file = fget(ctx->fd); |
| |
| if (IS_ENABLED(CONFIG_BLOCK) && ctx->is_bdev) { |
| err = get_tree_bdev(fsc, fuse_fill_super); |
| goto out; |
| } |
| /* |
| * While block dev mount can be initialized with a dummy device fd |
| * (found by device name), normal fuse mounts can't |
| */ |
| err = -EINVAL; |
| if (!ctx->file) |
| goto out; |
| |
| /* |
| * Allow creating a fuse mount with an already initialized fuse |
| * connection |
| */ |
| fud = READ_ONCE(ctx->file->private_data); |
| if (ctx->file->f_op == &fuse_dev_operations && fud) { |
| fsc->sget_key = fud->fc; |
| sb = sget_fc(fsc, fuse_test_super, fuse_set_no_super); |
| err = PTR_ERR_OR_ZERO(sb); |
| if (!IS_ERR(sb)) |
| fsc->root = dget(sb->s_root); |
| } else { |
| err = get_tree_nodev(fsc, fuse_fill_super); |
| } |
| out: |
| if (fsc->s_fs_info) |
| fuse_mount_destroy(fm); |
| if (ctx->file) |
| fput(ctx->file); |
| return err; |
| } |
| |
| static const struct fs_context_operations fuse_context_ops = { |
| .free = fuse_free_fsc, |
| .parse_param = fuse_parse_param, |
| .reconfigure = fuse_reconfigure, |
| .get_tree = fuse_get_tree, |
| }; |
| |
| /* |
| * Set up the filesystem mount context. |
| */ |
| static int fuse_init_fs_context(struct fs_context *fsc) |
| { |
| struct fuse_fs_context *ctx; |
| |
| ctx = kzalloc(sizeof(struct fuse_fs_context), GFP_KERNEL); |
| if (!ctx) |
| return -ENOMEM; |
| |
| ctx->max_read = ~0; |
| ctx->blksize = FUSE_DEFAULT_BLKSIZE; |
| ctx->legacy_opts_show = true; |
| |
| #ifdef CONFIG_BLOCK |
| if (fsc->fs_type == &fuseblk_fs_type) { |
| ctx->is_bdev = true; |
| ctx->destroy = true; |
| } |
| #endif |
| |
| fsc->fs_private = ctx; |
| fsc->ops = &fuse_context_ops; |
| return 0; |
| } |
| |
| bool fuse_mount_remove(struct fuse_mount *fm) |
| { |
| struct fuse_conn *fc = fm->fc; |
| bool last = false; |
| |
| down_write(&fc->killsb); |
| list_del_init(&fm->fc_entry); |
| if (list_empty(&fc->mounts)) |
| last = true; |
| up_write(&fc->killsb); |
| |
| return last; |
| } |
| EXPORT_SYMBOL_GPL(fuse_mount_remove); |
| |
| void fuse_conn_destroy(struct fuse_mount *fm) |
| { |
| struct fuse_conn *fc = fm->fc; |
| |
| if (fc->destroy) |
| fuse_send_destroy(fm); |
| |
| fuse_abort_conn(fc); |
| fuse_wait_aborted(fc); |
| |
| if (!list_empty(&fc->entry)) { |
| mutex_lock(&fuse_mutex); |
| list_del(&fc->entry); |
| fuse_ctl_remove_conn(fc); |
| mutex_unlock(&fuse_mutex); |
| } |
| } |
| EXPORT_SYMBOL_GPL(fuse_conn_destroy); |
| |
| static void fuse_sb_destroy(struct super_block *sb) |
| { |
| struct fuse_mount *fm = get_fuse_mount_super(sb); |
| bool last; |
| |
| if (sb->s_root) { |
| last = fuse_mount_remove(fm); |
| if (last) |
| fuse_conn_destroy(fm); |
| } |
| } |
| |
| void fuse_mount_destroy(struct fuse_mount *fm) |
| { |
| fuse_conn_put(fm->fc); |
| kfree(fm); |
| } |
| EXPORT_SYMBOL(fuse_mount_destroy); |
| |
| static void fuse_kill_sb_anon(struct super_block *sb) |
| { |
| fuse_sb_destroy(sb); |
| kill_anon_super(sb); |
| fuse_mount_destroy(get_fuse_mount_super(sb)); |
| } |
| |
| static struct file_system_type fuse_fs_type = { |
| .owner = THIS_MODULE, |
| .name = "fuse", |
| .fs_flags = FS_HAS_SUBTYPE | FS_USERNS_MOUNT, |
| .init_fs_context = fuse_init_fs_context, |
| .parameters = fuse_fs_parameters, |
| .kill_sb = fuse_kill_sb_anon, |
| }; |
| MODULE_ALIAS_FS("fuse"); |
| |
| #ifdef CONFIG_BLOCK |
| static void fuse_kill_sb_blk(struct super_block *sb) |
| { |
| fuse_sb_destroy(sb); |
| kill_block_super(sb); |
| fuse_mount_destroy(get_fuse_mount_super(sb)); |
| } |
| |
| static struct file_system_type fuseblk_fs_type = { |
| .owner = THIS_MODULE, |
| .name = "fuseblk", |
| .init_fs_context = fuse_init_fs_context, |
| .parameters = fuse_fs_parameters, |
| .kill_sb = fuse_kill_sb_blk, |
| .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE, |
| }; |
| MODULE_ALIAS_FS("fuseblk"); |
| |
| static inline int register_fuseblk(void) |
| { |
| return register_filesystem(&fuseblk_fs_type); |
| } |
| |
| static inline void unregister_fuseblk(void) |
| { |
| unregister_filesystem(&fuseblk_fs_type); |
| } |
| #else |
| static inline int register_fuseblk(void) |
| { |
| return 0; |
| } |
| |
| static inline void unregister_fuseblk(void) |
| { |
| } |
| #endif |
| |
| static void fuse_inode_init_once(void *foo) |
| { |
| struct inode *inode = foo; |
| |
| inode_init_once(inode); |
| } |
| |
| static int __init fuse_fs_init(void) |
| { |
| int err; |
| |
| fuse_inode_cachep = kmem_cache_create("fuse_inode", |
| sizeof(struct fuse_inode), 0, |
| SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT|SLAB_RECLAIM_ACCOUNT, |
| fuse_inode_init_once); |
| err = -ENOMEM; |
| if (!fuse_inode_cachep) |
| goto out; |
| |
| err = register_fuseblk(); |
| if (err) |
| goto out2; |
| |
| err = register_filesystem(&fuse_fs_type); |
| if (err) |
| goto out3; |
| |
| return 0; |
| |
| out3: |
| unregister_fuseblk(); |
| out2: |
| kmem_cache_destroy(fuse_inode_cachep); |
| out: |
| return err; |
| } |
| |
| static void fuse_fs_cleanup(void) |
| { |
| unregister_filesystem(&fuse_fs_type); |
| unregister_fuseblk(); |
| |
| /* |
| * Make sure all delayed rcu free inodes are flushed before we |
| * destroy cache. |
| */ |
| rcu_barrier(); |
| kmem_cache_destroy(fuse_inode_cachep); |
| } |
| |
| static struct kobject *fuse_kobj; |
| |
| static int fuse_sysfs_init(void) |
| { |
| int err; |
| |
| fuse_kobj = kobject_create_and_add("fuse", fs_kobj); |
| if (!fuse_kobj) { |
| err = -ENOMEM; |
| goto out_err; |
| } |
| |
| err = sysfs_create_mount_point(fuse_kobj, "connections"); |
| if (err) |
| goto out_fuse_unregister; |
| |
| return 0; |
| |
| out_fuse_unregister: |
| kobject_put(fuse_kobj); |
| out_err: |
| return err; |
| } |
| |
| static void fuse_sysfs_cleanup(void) |
| { |
| sysfs_remove_mount_point(fuse_kobj, "connections"); |
| kobject_put(fuse_kobj); |
| } |
| |
| static int __init fuse_init(void) |
| { |
| int res; |
| |
| pr_info("init (API version %i.%i)\n", |
| FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION); |
| |
| INIT_LIST_HEAD(&fuse_conn_list); |
| res = fuse_fs_init(); |
| if (res) |
| goto err; |
| |
| res = fuse_dev_init(); |
| if (res) |
| goto err_fs_cleanup; |
| |
| res = fuse_sysfs_init(); |
| if (res) |
| goto err_dev_cleanup; |
| |
| res = fuse_ctl_init(); |
| if (res) |
| goto err_sysfs_cleanup; |
| |
| sanitize_global_limit(&max_user_bgreq); |
| sanitize_global_limit(&max_user_congthresh); |
| |
| return 0; |
| |
| err_sysfs_cleanup: |
| fuse_sysfs_cleanup(); |
| err_dev_cleanup: |
| fuse_dev_cleanup(); |
| err_fs_cleanup: |
| fuse_fs_cleanup(); |
| err: |
| return res; |
| } |
| |
| static void __exit fuse_exit(void) |
| { |
| pr_debug("exit\n"); |
| |
| fuse_ctl_cleanup(); |
| fuse_sysfs_cleanup(); |
| fuse_fs_cleanup(); |
| fuse_dev_cleanup(); |
| } |
| |
| module_init(fuse_init); |
| module_exit(fuse_exit); |