/* FUSE: Filesystem in Userspace Copyright (C) 2001-2008 Miklos Szeredi This program can be distributed under the terms of the GNU GPL. See the file COPYING. */ #include "fuse_i.h" #include #include #include #include #include #include #include #include #include #include #include #include MODULE_AUTHOR("Miklos Szeredi "); 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, 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) struct fuse_mount_data { int fd; unsigned rootmode; unsigned user_id; unsigned group_id; unsigned fd_present:1; unsigned rootmode_present:1; unsigned user_id_present:1; unsigned group_id_present:1; unsigned flags; unsigned max_read; unsigned blksize; }; struct fuse_forget_link *fuse_alloc_forget(void) { return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL); } static struct inode *fuse_alloc_inode(struct super_block *sb) { struct inode *inode; struct fuse_inode *fi; inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL); if (!inode) return NULL; fi = get_fuse_inode(inode); fi->i_time = 0; fi->nodeid = 0; fi->nlookup = 0; fi->attr_version = 0; fi->writectr = 0; INIT_LIST_HEAD(&fi->write_files); INIT_LIST_HEAD(&fi->queued_writes); INIT_LIST_HEAD(&fi->writepages); init_waitqueue_head(&fi->page_waitq); fi->forget = fuse_alloc_forget(); if (!fi->forget) { kmem_cache_free(fuse_inode_cachep, inode); return NULL; } return inode; } static void fuse_i_callback(struct rcu_head *head) { struct inode *inode = container_of(head, struct inode, i_rcu); INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(fuse_inode_cachep, inode); } static void fuse_destroy_inode(struct inode *inode) { struct fuse_inode *fi = get_fuse_inode(inode); BUG_ON(!list_empty(&fi->write_files)); BUG_ON(!list_empty(&fi->queued_writes)); kfree(fi->forget); call_rcu(&inode->i_rcu, fuse_i_callback); } static void fuse_evict_inode(struct inode *inode) { truncate_inode_pages(&inode->i_data, 0); end_writeback(inode); if (inode->i_sb->s_flags & MS_ACTIVE) { struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_inode *fi = get_fuse_inode(inode); fuse_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup); fi->forget = NULL; } } static int fuse_remount_fs(struct super_block *sb, int *flags, char *data) { if (*flags & MS_MANDLOCK) return -EINVAL; return 0; } 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); fi->attr_version = ++fc->attr_version; fi->i_time = attr_valid; inode->i_ino = attr->ino; inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777); inode->i_nlink = attr->nlink; inode->i_uid = attr->uid; inode->i_gid = attr->gid; inode->i_blocks = attr->blocks; inode->i_atime.tv_sec = attr->atime; inode->i_atime.tv_nsec = attr->atimensec; 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->flags & FUSE_DEFAULT_PERMISSIONS)) inode->i_mode &= ~S_ISVTX; } 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); loff_t oldsize; spin_lock(&fc->lock); if (attr_version != 0 && fi->attr_version > attr_version) { spin_unlock(&fc->lock); return; } fuse_change_attributes_common(inode, attr, attr_valid); oldsize = inode->i_size; i_size_write(inode, attr->size); spin_unlock(&fc->lock); if (S_ISREG(inode->i_mode) && oldsize != attr->size) { truncate_pagecache(inode, oldsize, attr->size); 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; 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(); } 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); 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|S_NOCMTIME; inode->i_generation = generation; inode->i_data.backing_dev_info = &fc->bdi; fuse_init_inode(inode, attr); unlock_new_inode(inode); } else if ((inode->i_mode ^ attr->mode) & S_IFMT) { /* Inode has changed type, any I/O on the old should fail */ make_bad_inode(inode); iput(inode); goto retry; } fi = get_fuse_inode(inode); spin_lock(&fc->lock); fi->nlookup++; spin_unlock(&fc->lock); fuse_change_attributes(inode, attr, attr_valid, attr_version); return inode; } int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid, loff_t offset, loff_t len) { struct inode *inode; pgoff_t pg_start; pgoff_t pg_end; inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid); if (!inode) return -ENOENT; fuse_invalidate_attr(inode); if (offset >= 0) { pg_start = offset >> PAGE_CACHE_SHIFT; if (len <= 0) pg_end = -1; else pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT; invalidate_inode_pages2_range(inode->i_mapping, pg_start, pg_end); } iput(inode); return 0; } static void fuse_umount_begin(struct super_block *sb) { fuse_abort_conn(get_fuse_conn_super(sb)); } static void fuse_send_destroy(struct fuse_conn *fc) { struct fuse_req *req = fc->destroy_req; if (req && fc->conn_init) { fc->destroy_req = NULL; req->in.h.opcode = FUSE_DESTROY; req->force = 1; fuse_request_send(fc, req); fuse_put_request(fc, req); } } static void fuse_bdi_destroy(struct fuse_conn *fc) { if (fc->bdi_initialized) bdi_destroy(&fc->bdi); } void fuse_conn_kill(struct fuse_conn *fc) { spin_lock(&fc->lock); fc->connected = 0; fc->blocked = 0; spin_unlock(&fc->lock); /* Flush all readers on this fs */ kill_fasync(&fc->fasync, SIGIO, POLL_IN); wake_up_all(&fc->waitq); wake_up_all(&fc->blocked_waitq); wake_up_all(&fc->reserved_req_waitq); mutex_lock(&fuse_mutex); list_del(&fc->entry); fuse_ctl_remove_conn(fc); mutex_unlock(&fuse_mutex); fuse_bdi_destroy(fc); } EXPORT_SYMBOL_GPL(fuse_conn_kill); static void fuse_put_super(struct super_block *sb) { struct fuse_conn *fc = get_fuse_conn_super(sb); fuse_send_destroy(fc); fuse_conn_kill(fc); fuse_conn_put(fc); } 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_conn *fc = get_fuse_conn_super(sb); struct fuse_req *req; struct fuse_statfs_out outarg; int err; if (!fuse_allow_task(fc, current)) { buf->f_type = FUSE_SUPER_MAGIC; return 0; } req = fuse_get_req(fc); if (IS_ERR(req)) return PTR_ERR(req); memset(&outarg, 0, sizeof(outarg)); req->in.numargs = 0; req->in.h.opcode = FUSE_STATFS; req->in.h.nodeid = get_node_id(dentry->d_inode); req->out.numargs = 1; req->out.args[0].size = fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg); req->out.args[0].value = &outarg; fuse_request_send(fc, req); err = req->out.h.error; if (!err) convert_fuse_statfs(buf, &outarg.st); fuse_put_request(fc, req); return err; } enum { 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 match_table_t tokens = { {OPT_FD, "fd=%u"}, {OPT_ROOTMODE, "rootmode=%o"}, {OPT_USER_ID, "user_id=%u"}, {OPT_GROUP_ID, "group_id=%u"}, {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, {OPT_ALLOW_OTHER, "allow_other"}, {OPT_MAX_READ, "max_read=%u"}, {OPT_BLKSIZE, "blksize=%u"}, {OPT_ERR, NULL} }; static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev) { char *p; memset(d, 0, sizeof(struct fuse_mount_data)); d->max_read = ~0; d->blksize = FUSE_DEFAULT_BLKSIZE; while ((p = strsep(&opt, ",")) != NULL) { int token; int value; substring_t args[MAX_OPT_ARGS]; if (!*p) continue; token = match_token(p, tokens, args); switch (token) { case OPT_FD: if (match_int(&args[0], &value)) return 0; d->fd = value; d->fd_present = 1; break; case OPT_ROOTMODE: if (match_octal(&args[0], &value)) return 0; if (!fuse_valid_type(value)) return 0; d->rootmode = value; d->rootmode_present = 1; break; case OPT_USER_ID: if (match_int(&args[0], &value)) return 0; d->user_id = value; d->user_id_present = 1; break; case OPT_GROUP_ID: if (match_int(&args[0], &value)) return 0; d->group_id = value; d->group_id_present = 1; break; case OPT_DEFAULT_PERMISSIONS: d->flags |= FUSE_DEFAULT_PERMISSIONS; break; case OPT_ALLOW_OTHER: d->flags |= FUSE_ALLOW_OTHER; break; case OPT_MAX_READ: if (match_int(&args[0], &value)) return 0; d->max_read = value; break; case OPT_BLKSIZE: if (!is_bdev || match_int(&args[0], &value)) return 0; d->blksize = value; break; default: return 0; } } if (!d->fd_present || !d->rootmode_present || !d->user_id_present || !d->group_id_present) return 0; return 1; } static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt) { struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb); seq_printf(m, ",user_id=%u", fc->user_id); seq_printf(m, ",group_id=%u", fc->group_id); if (fc->flags & FUSE_DEFAULT_PERMISSIONS) seq_puts(m, ",default_permissions"); if (fc->flags & FUSE_ALLOW_OTHER) seq_puts(m, ",allow_other"); if (fc->max_read != ~0) seq_printf(m, ",max_read=%u", fc->max_read); if (mnt->mnt_sb->s_bdev && mnt->mnt_sb->s_blocksize != FUSE_DEFAULT_BLKSIZE) seq_printf(m, ",blksize=%lu", mnt->mnt_sb->s_blocksize); return 0; } void fuse_conn_init(struct fuse_conn *fc) { memset(fc, 0, sizeof(*fc)); spin_lock_init(&fc->lock); mutex_init(&fc->inst_mutex); init_rwsem(&fc->killsb); atomic_set(&fc->count, 1); init_waitqueue_head(&fc->waitq); init_waitqueue_head(&fc->blocked_waitq); init_waitqueue_head(&fc->reserved_req_waitq); INIT_LIST_HEAD(&fc->pending); INIT_LIST_HEAD(&fc->processing); INIT_LIST_HEAD(&fc->io); INIT_LIST_HEAD(&fc->interrupts); INIT_LIST_HEAD(&fc->bg_queue); INIT_LIST_HEAD(&fc->entry); fc->forget_list_tail = &fc->forget_list_head; atomic_set(&fc->num_waiting, 0); fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND; fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD; fc->khctr = 0; fc->polled_files = RB_ROOT; fc->reqctr = 0; fc->blocked = 1; fc->attr_version = 1; get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key)); } EXPORT_SYMBOL_GPL(fuse_conn_init); void fuse_conn_put(struct fuse_conn *fc) { if (atomic_dec_and_test(&fc->count)) { if (fc->destroy_req) fuse_request_free(fc->destroy_req); mutex_destroy(&fc->inst_mutex); fc->release(fc); } } EXPORT_SYMBOL_GPL(fuse_conn_put); struct fuse_conn *fuse_conn_get(struct fuse_conn *fc) { atomic_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; struct qstr name; if (!fc->export_support) goto out_err; name.len = 1; name.name = "."; 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 dentry *dentry, u32 *fh, int *max_len, int connectable) { struct inode *inode = dentry->d_inode; bool encode_parent = connectable && !S_ISDIR(inode->i_mode); int len = encode_parent ? 6 : 3; u64 nodeid; u32 generation; if (*max_len < len) { *max_len = len; return 255; } nodeid = get_fuse_inode(inode)->nodeid; generation = inode->i_generation; fh[0] = (u32)(nodeid >> 32); fh[1] = (u32)(nodeid & 0xffffffff); fh[2] = generation; if (encode_parent) { struct inode *parent; spin_lock(&dentry->d_lock); parent = dentry->d_parent->d_inode; nodeid = get_fuse_inode(parent)->nodeid; generation = parent->i_generation; spin_unlock(&dentry->d_lock); fh[3] = (u32)(nodeid >> 32); fh[4] = (u32)(nodeid & 0xffffffff); fh[5] = generation; } *max_len = len; return encode_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 = child->d_inode; struct fuse_conn *fc = get_fuse_conn(child_inode); struct inode *inode; struct dentry *parent; struct fuse_entry_out outarg; struct qstr name; int err; if (!fc->export_support) return ERR_PTR(-ESTALE); name.len = 2; name.name = ".."; err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode), &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, .destroy_inode = fuse_destroy_inode, .evict_inode = fuse_evict_inode, .drop_inode = generic_delete_inode, .remount_fs = fuse_remount_fs, .put_super = fuse_put_super, .umount_begin = fuse_umount_begin, .statfs = fuse_statfs, .show_options = fuse_show_options, }; static void sanitize_global_limit(unsigned *limit) { if (*limit == 0) *limit = ((num_physpages << PAGE_SHIFT) >> 13) / sizeof(struct fuse_req); if (*limit >= 1 << 16) *limit = (1 << 16) - 1; } static int set_global_limit(const char *val, 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); 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; } } static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req) { struct fuse_init_out *arg = &req->misc.init_out; if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION) fc->conn_error = 1; else { unsigned long ra_pages; process_init_limits(fc, arg); if (arg->minor >= 6) { ra_pages = arg->max_readahead / PAGE_CACHE_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; } 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; } else { ra_pages = fc->max_read / PAGE_CACHE_SIZE; fc->no_lock = 1; fc->no_flock = 1; } fc->bdi.ra_pages = min(fc->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; } fc->blocked = 0; wake_up_all(&fc->blocked_waitq); } static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req) { struct fuse_init_in *arg = &req->misc.init_in; arg->major = FUSE_KERNEL_VERSION; arg->minor = FUSE_KERNEL_MINOR_VERSION; arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE; arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC | FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK | FUSE_FLOCK_LOCKS; req->in.h.opcode = FUSE_INIT; req->in.numargs = 1; req->in.args[0].size = sizeof(*arg); req->in.args[0].value = arg; req->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 */ req->out.argvar = 1; req->out.args[0].size = sizeof(struct fuse_init_out); req->out.args[0].value = &req->misc.init_out; req->end = process_init_reply; fuse_request_send_background(fc, req); } static void fuse_free_conn(struct fuse_conn *fc) { kfree(fc); } static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb) { int err; fc->bdi.name = "fuse"; fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE; /* fuse does it's own writeback accounting */ fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB; err = bdi_init(&fc->bdi); if (err) return err; fc->bdi_initialized = 1; if (sb->s_bdev) { err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk", MAJOR(fc->dev), MINOR(fc->dev)); } else { err = bdi_register_dev(&fc->bdi, fc->dev); } if (err) return err; /* * 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//max_ratio */ bdi_set_max_ratio(&fc->bdi, 1); return 0; } static int fuse_fill_super(struct super_block *sb, void *data, int silent) { struct fuse_conn *fc; struct inode *root; struct fuse_mount_data d; struct file *file; struct dentry *root_dentry; struct fuse_req *init_req; int err; int is_bdev = sb->s_bdev != NULL; err = -EINVAL; if (sb->s_flags & MS_MANDLOCK) goto err; if (!parse_fuse_opt((char *) data, &d, is_bdev)) goto err; if (is_bdev) { #ifdef CONFIG_BLOCK err = -EINVAL; if (!sb_set_blocksize(sb, d.blksize)) goto err; #endif } else { sb->s_blocksize = PAGE_CACHE_SIZE; sb->s_blocksize_bits = PAGE_CACHE_SHIFT; } sb->s_magic = FUSE_SUPER_MAGIC; sb->s_op = &fuse_super_operations; sb->s_maxbytes = MAX_LFS_FILESIZE; sb->s_export_op = &fuse_export_operations; file = fget(d.fd); err = -EINVAL; if (!file) goto err; if (file->f_op != &fuse_dev_operations) goto err_fput; fc = kmalloc(sizeof(*fc), GFP_KERNEL); err = -ENOMEM; if (!fc) goto err_fput; fuse_conn_init(fc); fc->dev = sb->s_dev; fc->sb = sb; err = fuse_bdi_init(fc, sb); if (err) goto err_put_conn; sb->s_bdi = &fc->bdi; /* Handle umasking inside the fuse code */ if (sb->s_flags & MS_POSIXACL) fc->dont_mask = 1; sb->s_flags |= MS_POSIXACL; fc->release = fuse_free_conn; fc->flags = d.flags; fc->user_id = d.user_id; fc->group_id = d.group_id; fc->max_read = max_t(unsigned, 4096, d.max_read); /* Used by get_root_inode() */ sb->s_fs_info = fc; err = -ENOMEM; root = fuse_get_root_inode(sb, d.rootmode); if (!root) goto err_put_conn; root_dentry = d_alloc_root(root); if (!root_dentry) { iput(root); goto err_put_conn; } /* only now - we want root dentry with NULL ->d_op */ sb->s_d_op = &fuse_dentry_operations; init_req = fuse_request_alloc(); if (!init_req) goto err_put_root; if (is_bdev) { fc->destroy_req = fuse_request_alloc(); if (!fc->destroy_req) goto err_free_init_req; } mutex_lock(&fuse_mutex); err = -EINVAL; if (file->private_data) 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; fc->connected = 1; file->private_data = fuse_conn_get(fc); mutex_unlock(&fuse_mutex); /* * atomic_dec_and_test() in fput() provides the necessary * memory barrier for file->private_data to be visible on all * CPUs after this */ fput(file); fuse_send_init(fc, init_req); return 0; err_unlock: mutex_unlock(&fuse_mutex); err_free_init_req: fuse_request_free(init_req); err_put_root: dput(root_dentry); err_put_conn: fuse_bdi_destroy(fc); fuse_conn_put(fc); err_fput: fput(file); err: return err; } static struct dentry *fuse_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *raw_data) { return mount_nodev(fs_type, flags, raw_data, fuse_fill_super); } static void fuse_kill_sb_anon(struct super_block *sb) { struct fuse_conn *fc = get_fuse_conn_super(sb); if (fc) { down_write(&fc->killsb); fc->sb = NULL; up_write(&fc->killsb); } kill_anon_super(sb); } static struct file_system_type fuse_fs_type = { .owner = THIS_MODULE, .name = "fuse", .fs_flags = FS_HAS_SUBTYPE, .mount = fuse_mount, .kill_sb = fuse_kill_sb_anon, }; #ifdef CONFIG_BLOCK static struct dentry *fuse_mount_blk(struct file_system_type *fs_type, int flags, const char *dev_name, void *raw_data) { return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super); } static void fuse_kill_sb_blk(struct super_block *sb) { struct fuse_conn *fc = get_fuse_conn_super(sb); if (fc) { down_write(&fc->killsb); fc->sb = NULL; up_write(&fc->killsb); } kill_block_super(sb); } static struct file_system_type fuseblk_fs_type = { .owner = THIS_MODULE, .name = "fuseblk", .mount = fuse_mount_blk, .kill_sb = fuse_kill_sb_blk, .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE, }; 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; err = register_filesystem(&fuse_fs_type); if (err) goto out; err = register_fuseblk(); if (err) goto out_unreg; fuse_inode_cachep = kmem_cache_create("fuse_inode", sizeof(struct fuse_inode), 0, SLAB_HWCACHE_ALIGN, fuse_inode_init_once); err = -ENOMEM; if (!fuse_inode_cachep) goto out_unreg2; return 0; out_unreg2: unregister_fuseblk(); out_unreg: unregister_filesystem(&fuse_fs_type); out: return err; } static void fuse_fs_cleanup(void) { unregister_filesystem(&fuse_fs_type); unregister_fuseblk(); kmem_cache_destroy(fuse_inode_cachep); } static struct kobject *fuse_kobj; static struct kobject *connections_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; } connections_kobj = kobject_create_and_add("connections", fuse_kobj); if (!connections_kobj) { err = -ENOMEM; goto out_fuse_unregister; } return 0; out_fuse_unregister: kobject_put(fuse_kobj); out_err: return err; } static void fuse_sysfs_cleanup(void) { kobject_put(connections_kobj); kobject_put(fuse_kobj); } static int __init fuse_init(void) { int res; printk(KERN_INFO "fuse 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) { printk(KERN_DEBUG "fuse exit\n"); fuse_ctl_cleanup(); fuse_sysfs_cleanup(); fuse_fs_cleanup(); fuse_dev_cleanup(); } module_init(fuse_init); module_exit(fuse_exit);