| /* |
| 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/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, 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; |
| kuid_t user_id; |
| kgid_t group_id; |
| unsigned fd_present:1; |
| unsigned rootmode_present:1; |
| unsigned user_id_present:1; |
| unsigned group_id_present:1; |
| unsigned default_permissions:1; |
| unsigned allow_other:1; |
| 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; |
| fi->orig_ino = 0; |
| fi->state = 0; |
| INIT_LIST_HEAD(&fi->write_files); |
| INIT_LIST_HEAD(&fi->queued_writes); |
| INIT_LIST_HEAD(&fi->writepages); |
| init_waitqueue_head(&fi->page_waitq); |
| mutex_init(&fi->mutex); |
| 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); |
| 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)); |
| mutex_destroy(&fi->mutex); |
| kfree(fi->forget); |
| call_rcu(&inode->i_rcu, fuse_i_callback); |
| } |
| |
| static void fuse_evict_inode(struct inode *inode) |
| { |
| truncate_inode_pages_final(&inode->i_data); |
| clear_inode(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) |
| { |
| sync_filesystem(sb); |
| if (*flags & MS_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); |
| |
| fi->attr_version = ++fc->attr_version; |
| fi->i_time = attr_valid; |
| |
| 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(&init_user_ns, attr->uid); |
| inode->i_gid = make_kgid(&init_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; |
| } |
| |
| 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 timespec old_mtime; |
| |
| spin_lock(&fc->lock); |
| if ((attr_version != 0 && fi->attr_version > attr_version) || |
| test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) { |
| spin_unlock(&fc->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(&fc->lock); |
| |
| if (!is_wb && S_ISREG(inode->i_mode)) { |
| bool inval = false; |
| |
| if (oldsize != attr->size) { |
| truncate_pagecache(inode, attr->size); |
| inval = true; |
| } else if (fc->auto_inval_data) { |
| struct timespec new_mtime = { |
| .tv_sec = attr->mtime, |
| .tv_nsec = attr->mtimensec, |
| }; |
| |
| /* |
| * Auto inval mode also checks and invalidates if mtime |
| * has changed. |
| */ |
| if (!timespec_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(); |
| } |
| |
| 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; |
| 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 ((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); |
| 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; |
| } |
| |
| void fuse_lock_inode(struct inode *inode) |
| { |
| if (!get_fuse_conn(inode)->parallel_dirops) |
| mutex_lock(&get_fuse_inode(inode)->mutex); |
| } |
| |
| void fuse_unlock_inode(struct inode *inode) |
| { |
| if (!get_fuse_conn(inode)->parallel_dirops) |
| mutex_unlock(&get_fuse_inode(inode)->mutex); |
| } |
| |
| 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; |
| __set_bit(FR_FORCE, &req->flags); |
| __clear_bit(FR_BACKGROUND, &req->flags); |
| 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); |
| } |
| |
| static void fuse_put_super(struct super_block *sb) |
| { |
| struct fuse_conn *fc = get_fuse_conn_super(sb); |
| |
| fuse_send_destroy(fc); |
| |
| fuse_abort_conn(fc); |
| mutex_lock(&fuse_mutex); |
| list_del(&fc->entry); |
| fuse_ctl_remove_conn(fc); |
| mutex_unlock(&fuse_mutex); |
| fuse_bdi_destroy(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); |
| FUSE_ARGS(args); |
| struct fuse_statfs_out outarg; |
| int err; |
| |
| if (!fuse_allow_current_process(fc)) { |
| buf->f_type = FUSE_SUPER_MAGIC; |
| return 0; |
| } |
| |
| memset(&outarg, 0, sizeof(outarg)); |
| args.in.numargs = 0; |
| args.in.h.opcode = FUSE_STATFS; |
| args.in.h.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(fc, &args); |
| if (!err) |
| convert_fuse_statfs(buf, &outarg.st); |
| 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 fuse_match_uint(substring_t *s, unsigned int *res) |
| { |
| int err = -ENOMEM; |
| char *buf = match_strdup(s); |
| if (buf) { |
| err = kstrtouint(buf, 10, res); |
| kfree(buf); |
| } |
| return err; |
| } |
| |
| 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; |
| unsigned uv; |
| 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 (fuse_match_uint(&args[0], &uv)) |
| return 0; |
| d->user_id = make_kuid(current_user_ns(), uv); |
| if (!uid_valid(d->user_id)) |
| return 0; |
| d->user_id_present = 1; |
| break; |
| |
| case OPT_GROUP_ID: |
| if (fuse_match_uint(&args[0], &uv)) |
| return 0; |
| d->group_id = make_kgid(current_user_ns(), uv); |
| if (!gid_valid(d->group_id)) |
| return 0; |
| d->group_id_present = 1; |
| break; |
| |
| case OPT_DEFAULT_PERMISSIONS: |
| d->default_permissions = 1; |
| break; |
| |
| case OPT_ALLOW_OTHER: |
| d->allow_other = 1; |
| 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 dentry *root) |
| { |
| struct super_block *sb = root->d_sb; |
| struct fuse_conn *fc = get_fuse_conn_super(sb); |
| |
| seq_printf(m, ",user_id=%u", from_kuid_munged(&init_user_ns, fc->user_id)); |
| seq_printf(m, ",group_id=%u", from_kgid_munged(&init_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); |
| return 0; |
| } |
| |
| static void fuse_iqueue_init(struct fuse_iqueue *fiq) |
| { |
| memset(fiq, 0, sizeof(struct fuse_iqueue)); |
| 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; |
| } |
| |
| static void fuse_pqueue_init(struct fuse_pqueue *fpq) |
| { |
| memset(fpq, 0, sizeof(struct fuse_pqueue)); |
| spin_lock_init(&fpq->lock); |
| INIT_LIST_HEAD(&fpq->processing); |
| INIT_LIST_HEAD(&fpq->io); |
| fpq->connected = 1; |
| } |
| |
| void fuse_conn_init(struct fuse_conn *fc) |
| { |
| memset(fc, 0, sizeof(*fc)); |
| spin_lock_init(&fc->lock); |
| init_rwsem(&fc->killsb); |
| refcount_set(&fc->count, 1); |
| atomic_set(&fc->dev_count, 1); |
| init_waitqueue_head(&fc->blocked_waitq); |
| init_waitqueue_head(&fc->reserved_req_waitq); |
| fuse_iqueue_init(&fc->iq); |
| 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; |
| fc->khctr = 0; |
| fc->polled_files = RB_ROOT; |
| fc->blocked = 0; |
| fc->initialized = 0; |
| fc->connected = 1; |
| 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)); |
| } |
| EXPORT_SYMBOL_GPL(fuse_conn_init); |
| |
| void fuse_conn_put(struct fuse_conn *fc) |
| { |
| if (refcount_dec_and_test(&fc->count)) { |
| if (fc->destroy_req) |
| fuse_request_free(fc->destroy_req); |
| put_pid_ns(fc->pid_ns); |
| 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; |
| const struct qstr name = QSTR_INIT("..", 2); |
| int err; |
| |
| if (!fc->export_support) |
| return ERR_PTR(-ESTALE); |
| |
| 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, |
| .write_inode = fuse_write_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 = ((totalram_pages << 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_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; |
| 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) |
| fc->sb->s_time_gran = arg->time_gran; |
| if ((arg->flags & FUSE_POSIX_ACL)) { |
| fc->default_permissions = 1; |
| fc->posix_acl = 1; |
| fc->sb->s_xattr = fuse_acl_xattr_handlers; |
| } |
| } else { |
| ra_pages = fc->max_read / PAGE_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; |
| } |
| fuse_set_initialized(fc); |
| 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_SIZE; |
| arg->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; |
| 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) |
| { |
| WARN_ON(!list_empty(&fc->devices)); |
| kfree_rcu(fc, rcu); |
| } |
| |
| 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_SIZE; |
| /* fuse does it's own writeback accounting */ |
| fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT; |
| |
| 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/<bdi>/max_ratio |
| */ |
| bdi_set_max_ratio(&fc->bdi, 1); |
| |
| return 0; |
| } |
| |
| struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc) |
| { |
| struct fuse_dev *fud; |
| |
| fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL); |
| if (fud) { |
| fud->fc = fuse_conn_get(fc); |
| fuse_pqueue_init(&fud->pq); |
| |
| spin_lock(&fc->lock); |
| list_add_tail(&fud->entry, &fc->devices); |
| spin_unlock(&fc->lock); |
| } |
| |
| return fud; |
| } |
| EXPORT_SYMBOL_GPL(fuse_dev_alloc); |
| |
| 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); |
| } |
| EXPORT_SYMBOL_GPL(fuse_dev_free); |
| |
| static int fuse_fill_super(struct super_block *sb, void *data, int silent) |
| { |
| struct fuse_dev *fud; |
| 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; |
| |
| sb->s_flags &= ~(MS_NOSEC | MS_I_VERSION); |
| |
| if (!parse_fuse_opt(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_SIZE; |
| sb->s_blocksize_bits = PAGE_SHIFT; |
| } |
| 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; |
| |
| file = fget(d.fd); |
| err = -EINVAL; |
| if (!file) |
| goto err; |
| |
| if ((file->f_op != &fuse_dev_operations) || |
| (file->f_cred->user_ns != &init_user_ns)) |
| goto err_fput; |
| |
| fc = kmalloc(sizeof(*fc), GFP_KERNEL); |
| err = -ENOMEM; |
| if (!fc) |
| goto err_fput; |
| |
| fuse_conn_init(fc); |
| fc->release = fuse_free_conn; |
| |
| fud = fuse_dev_alloc(fc); |
| if (!fud) |
| goto err_put_conn; |
| |
| fc->dev = sb->s_dev; |
| fc->sb = sb; |
| err = fuse_bdi_init(fc, sb); |
| if (err) |
| goto err_dev_free; |
| |
| 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->default_permissions = d.default_permissions; |
| fc->allow_other = d.allow_other; |
| 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); |
| 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; |
| |
| init_req = fuse_request_alloc(0); |
| if (!init_req) |
| goto err_put_root; |
| __set_bit(FR_BACKGROUND, &init_req->flags); |
| |
| if (is_bdev) { |
| fc->destroy_req = fuse_request_alloc(0); |
| 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; |
| file->private_data = fud; |
| 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_dev_free: |
| fuse_dev_free(fud); |
| 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, |
| }; |
| MODULE_ALIAS_FS("fuse"); |
| |
| #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, |
| }; |
| 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, |
| 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; |
| |
| 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); |