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- /*
- 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, 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)
- 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 & SB_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 & 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);
- 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(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;
- }
- 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(&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 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();
- }
- 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;
- }
- 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)
- {
- fuse_abort_conn(get_fuse_conn_super(sb), false);
- }
- 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_put_super(struct super_block *sb)
- {
- struct fuse_conn *fc = get_fuse_conn_super(sb);
- mutex_lock(&fuse_mutex);
- list_del(&fc->entry);
- fuse_ctl_remove_conn(fc);
- mutex_unlock(&fuse_mutex);
- 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,
- struct user_namespace *user_ns)
- {
- 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(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(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(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);
- return 0;
- }
- static void fuse_iqueue_init(struct fuse_iqueue *fiq)
- {
- 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;
- }
- 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, struct user_namespace *user_ns)
- {
- 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));
- fc->user_ns = get_user_ns(user_ns);
- }
- 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);
- put_user_ns(fc->user_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, 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);
- 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;
- }
- if (arg->flags & FUSE_ABORT_ERROR)
- fc->abort_err = 1;
- } else {
- ra_pages = fc->max_read / PAGE_SIZE;
- fc->no_lock = 1;
- fc->no_flock = 1;
- }
- fc->sb->s_bdi->ra_pages =
- min(fc->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;
- }
- 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->sb->s_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 |
- FUSE_ABORT_ERROR;
- 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;
- 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;
- sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_SIZE;
- /* fuse does it's own writeback accounting */
- sb->s_bdi->capabilities = BDI_CAP_NO_ACCT_WB | 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(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 & SB_MANDLOCK)
- goto err;
- sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION);
- if (!parse_fuse_opt(data, &d, is_bdev, sb->s_user_ns))
- 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;
- sb->s_iflags |= SB_I_IMA_UNVERIFIABLE_SIGNATURE;
- if (sb->s_user_ns != &init_user_ns)
- sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER;
- file = fget(d.fd);
- err = -EINVAL;
- if (!file)
- goto err;
- /*
- * Require mount to happen from the same user namespace which
- * opened /dev/fuse to prevent potential attacks.
- */
- if (file->f_op != &fuse_dev_operations ||
- file->f_cred->user_ns != sb->s_user_ns)
- goto err_fput;
- /*
- * 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;
- fc = kmalloc(sizeof(*fc), GFP_KERNEL);
- err = -ENOMEM;
- if (!fc)
- goto err_fput;
- fuse_conn_init(fc, sb->s_user_ns);
- 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;
- /* Handle umasking inside the fuse code */
- if (sb->s_flags & SB_POSIXACL)
- fc->dont_mask = 1;
- sb->s_flags |= SB_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_conn_put(fc);
- sb->s_fs_info = NULL;
- 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_sb_destroy(struct super_block *sb)
- {
- struct fuse_conn *fc = get_fuse_conn_super(sb);
- if (fc) {
- fuse_send_destroy(fc);
- fuse_abort_conn(fc, false);
- fuse_wait_aborted(fc);
- down_write(&fc->killsb);
- fc->sb = NULL;
- up_write(&fc->killsb);
- }
- }
- static void fuse_kill_sb_anon(struct super_block *sb)
- {
- fuse_sb_destroy(sb);
- kill_anon_super(sb);
- }
- static struct file_system_type fuse_fs_type = {
- .owner = THIS_MODULE,
- .name = "fuse",
- .fs_flags = FS_HAS_SUBTYPE | FS_USERNS_MOUNT,
- .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)
- {
- fuse_sb_destroy(sb);
- 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|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;
- 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);
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