| /* |
| FUSE: Filesystem in Userspace |
| Copyright (C) 2001 Miklos Szeredi (mszeredi@inf.bme.hu) |
| |
| This program can be distributed under the terms of the GNU GPL. |
| See the file COPYING. |
| */ |
| |
| #include "fuse_i.h" |
| |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/poll.h> |
| #include <linux/proc_fs.h> |
| #include <linux/file.h> |
| |
| #define IHSIZE sizeof(struct fuse_in_header) |
| #define OHSIZE sizeof(struct fuse_out_header) |
| |
| static struct proc_dir_entry *proc_fs_fuse; |
| struct proc_dir_entry *proc_fuse_dev; |
| |
| static int request_wait_answer(struct fuse_req *req) |
| { |
| int ret = 0; |
| DECLARE_WAITQUEUE(wait, current); |
| |
| add_wait_queue(&req->waitq, &wait); |
| while(!list_empty(&req->list)) { |
| set_current_state(TASK_INTERRUPTIBLE); |
| if(signal_pending(current)) { |
| ret = -EINTR; |
| break; |
| } |
| spin_unlock(&fuse_lock); |
| schedule(); |
| spin_lock(&fuse_lock); |
| } |
| set_current_state(TASK_RUNNING); |
| remove_wait_queue(&req->waitq, &wait); |
| |
| return ret; |
| } |
| |
| static int request_check(struct fuse_req *req, struct fuse_out *outp) |
| { |
| struct fuse_out_header *oh; |
| unsigned int size; |
| |
| if(!req->out) |
| return -ECONNABORTED; |
| |
| oh = (struct fuse_out_header *) req->out; |
| size = req->outsize - OHSIZE; |
| |
| if (oh->error <= -512 || oh->error > 0) { |
| printk("fuse: bad error value: %i\n", oh->error); |
| return -EPROTO; |
| } |
| |
| if(size > outp->argsize || |
| (oh->error == 0 && !outp->argvar && size != outp->argsize) || |
| (oh->error != 0 && size != 0)) { |
| printk("fuse: invalid argument length: %i (%i)\n", size, |
| req->opcode); |
| return -EPROTO; |
| } |
| |
| memcpy(&outp->h, oh, OHSIZE); |
| outp->argsize = size; |
| if(size) |
| memcpy(outp->arg, req->out + OHSIZE, size); |
| |
| return oh->error; |
| } |
| |
| static void request_free(struct fuse_req *req) |
| { |
| kfree(req->in); |
| kfree(req->out); |
| kfree(req); |
| } |
| |
| |
| static struct fuse_req *request_new(struct fuse_conn *fc, struct fuse_in *inp, |
| struct fuse_out *outp) |
| { |
| struct fuse_req *req; |
| |
| req = kmalloc(sizeof(*req), GFP_NOFS); |
| if(!req) |
| return NULL; |
| |
| if(outp) |
| req->outsize = OHSIZE + outp->argsize; |
| else |
| req->outsize = 0; |
| req->out = NULL; |
| |
| req->insize = IHSIZE + inp->argsize; |
| req->in = kmalloc(req->insize, GFP_NOFS); |
| if(!req->in) { |
| request_free(req); |
| return NULL; |
| } |
| memcpy(req->in, &inp->h, IHSIZE); |
| if(inp->argsize) |
| memcpy(req->in + IHSIZE, inp->arg, inp->argsize); |
| |
| req->opcode = inp->h.opcode; |
| init_waitqueue_head(&req->waitq); |
| |
| return req; |
| } |
| |
| /* If 'outp' is NULL then the request this is asynchronous */ |
| void request_send(struct fuse_conn *fc, struct fuse_in *inp, |
| struct fuse_out *outp) |
| { |
| int ret; |
| struct fuse_in_header *ih; |
| struct fuse_req *req; |
| |
| ret = -ENOMEM; |
| req = request_new(fc, inp, outp); |
| if(!req) |
| goto out; |
| |
| spin_lock(&fuse_lock); |
| ret = -ENOTCONN; |
| if(fc->file == NULL) |
| goto out_unlock_free; |
| |
| ih = (struct fuse_in_header *) req->in; |
| if(outp) { |
| do fc->reqctr++; |
| while(!fc->reqctr); |
| ih->unique = req->unique = fc->reqctr; |
| } |
| else |
| ih->unique = req->unique = 0; |
| |
| list_add_tail(&req->list, &fc->pending); |
| wake_up(&fc->waitq); |
| |
| /* Async reqests are freed in fuse_dev_read() */ |
| if(!outp) |
| goto out_unlock; |
| |
| ret = request_wait_answer(req); |
| list_del(&req->list); |
| if(!ret) |
| ret = request_check(req, outp); |
| |
| out_unlock_free: |
| request_free(req); |
| out_unlock: |
| spin_unlock(&fuse_lock); |
| out: |
| if(outp) |
| outp->h.error = ret; |
| } |
| |
| static int request_wait(struct fuse_conn *fc) |
| { |
| int ret = 0; |
| DECLARE_WAITQUEUE(wait, current); |
| |
| add_wait_queue(&fc->waitq, &wait); |
| while(list_empty(&fc->pending)) { |
| set_current_state(TASK_INTERRUPTIBLE); |
| if(signal_pending(current)) { |
| ret = -ERESTARTSYS; |
| break; |
| } |
| spin_unlock(&fuse_lock); |
| schedule(); |
| spin_lock(&fuse_lock); |
| } |
| set_current_state(TASK_RUNNING); |
| remove_wait_queue(&fc->waitq, &wait); |
| |
| return ret; |
| } |
| |
| |
| static ssize_t fuse_dev_read(struct file *file, char *buf, size_t nbytes, |
| loff_t *off) |
| { |
| int ret; |
| struct fuse_conn *fc = DEV_FC(file); |
| struct fuse_req *req; |
| char *tmpbuf; |
| unsigned int size; |
| |
| if(fc->sb == NULL) |
| return -EPERM; |
| |
| spin_lock(&fuse_lock); |
| ret = request_wait(fc); |
| if(ret) |
| goto err; |
| |
| req = list_entry(fc->pending.next, struct fuse_req, list); |
| size = req->insize; |
| if(nbytes < size) { |
| printk("fuse_dev_read[%i]: buffer too small\n", fc->id); |
| ret = -EIO; |
| goto err; |
| } |
| tmpbuf = req->in; |
| req->in = NULL; |
| |
| list_del(&req->list); |
| if(req->outsize) |
| list_add_tail(&req->list, &fc->processing); |
| else |
| request_free(req); |
| spin_unlock(&fuse_lock); |
| |
| if(copy_to_user(buf, tmpbuf, size)) |
| return -EFAULT; |
| |
| return size; |
| |
| err: |
| spin_unlock(&fuse_lock); |
| return ret; |
| } |
| |
| static struct fuse_req *request_find(struct fuse_conn *fc, unsigned int unique) |
| { |
| struct list_head *entry; |
| struct fuse_req *req = NULL; |
| |
| list_for_each(entry, &fc->processing) { |
| struct fuse_req *tmp; |
| tmp = list_entry(entry, struct fuse_req, list); |
| if(tmp->unique == unique) { |
| req = tmp; |
| break; |
| } |
| } |
| |
| return req; |
| } |
| |
| static ssize_t fuse_dev_write(struct file *file, const char *buf, |
| size_t nbytes, loff_t *off) |
| { |
| ssize_t ret; |
| struct fuse_conn *fc = DEV_FC(file); |
| struct fuse_req *req; |
| char *tmpbuf; |
| struct fuse_out_header *oh; |
| |
| if(!fc->sb) |
| return -EPERM; |
| |
| ret = -EIO; |
| if(nbytes < OHSIZE || nbytes > OHSIZE + PAGE_SIZE) { |
| printk("fuse_dev_write[%i]: write is short or long\n", fc->id); |
| goto out; |
| } |
| |
| ret = -ENOMEM; |
| tmpbuf = kmalloc(nbytes, GFP_KERNEL); |
| if(!tmpbuf) |
| goto out; |
| |
| ret = -EFAULT; |
| if(copy_from_user(tmpbuf, buf, nbytes)) |
| goto out_free; |
| |
| spin_lock(&fuse_lock); |
| oh = (struct fuse_out_header *) tmpbuf; |
| req = request_find(fc, oh->unique); |
| if(req == NULL) { |
| ret = -ENOENT; |
| goto out_free_unlock; |
| } |
| list_del_init(&req->list); |
| if(req->opcode == FUSE_GETDIR) { |
| /* fget() needs to be done in this context */ |
| struct fuse_getdir_out *arg; |
| arg = (struct fuse_getdir_out *) (tmpbuf + OHSIZE); |
| arg->file = fget(arg->fd); |
| } |
| req->out = tmpbuf; |
| req->outsize = nbytes; |
| tmpbuf = NULL; |
| ret = nbytes; |
| wake_up(&req->waitq); |
| out_free_unlock: |
| spin_unlock(&fuse_lock); |
| out_free: |
| kfree(tmpbuf); |
| out: |
| return ret; |
| } |
| |
| |
| static unsigned int fuse_dev_poll(struct file *file, poll_table *wait) |
| { |
| struct fuse_conn *fc = DEV_FC(file); |
| unsigned int mask = POLLOUT | POLLWRNORM; |
| |
| if(!fc->sb) |
| return -EPERM; |
| |
| poll_wait(file, &fc->waitq, wait); |
| |
| spin_lock(&fuse_lock); |
| if (!list_empty(&fc->pending)) |
| mask |= POLLIN | POLLRDNORM; |
| spin_unlock(&fuse_lock); |
| |
| return mask; |
| } |
| |
| static struct fuse_conn *new_conn(void) |
| { |
| static int connctr = 1; |
| struct fuse_conn *fc; |
| |
| fc = kmalloc(sizeof(*fc), GFP_KERNEL); |
| if(fc != NULL) { |
| fc->sb = NULL; |
| fc->file = NULL; |
| init_waitqueue_head(&fc->waitq); |
| INIT_LIST_HEAD(&fc->pending); |
| INIT_LIST_HEAD(&fc->processing); |
| fc->reqctr = 1; |
| fc->cleared = NULL; |
| fc->numcleared = 0; |
| |
| spin_lock(&fuse_lock); |
| fc->id = connctr ++; |
| spin_unlock(&fuse_lock); |
| } |
| return fc; |
| } |
| |
| static int fuse_dev_open(struct inode *inode, struct file *file) |
| { |
| struct fuse_conn *fc; |
| |
| fc = new_conn(); |
| if(!fc) |
| return -ENOMEM; |
| |
| fc->file = file; |
| file->private_data = fc; |
| |
| return 0; |
| } |
| |
| static void end_requests(struct list_head *head) |
| { |
| while(!list_empty(head)) { |
| struct fuse_req *req; |
| req = list_entry(head->next, struct fuse_req, list); |
| list_del_init(&req->list); |
| if(req->outsize) |
| wake_up(&req->waitq); |
| else |
| request_free(req); |
| } |
| } |
| |
| static int fuse_dev_release(struct inode *inode, struct file *file) |
| { |
| struct fuse_conn *fc = DEV_FC(file); |
| |
| spin_lock(&fuse_lock); |
| fc->file = NULL; |
| end_requests(&fc->pending); |
| end_requests(&fc->processing); |
| kfree(fc->cleared); |
| fc->cleared = NULL; |
| fc->numcleared = 0; |
| fuse_release_conn(fc); |
| spin_unlock(&fuse_lock); |
| return 0; |
| } |
| |
| static struct file_operations fuse_dev_operations = { |
| owner: THIS_MODULE, |
| read: fuse_dev_read, |
| write: fuse_dev_write, |
| poll: fuse_dev_poll, |
| open: fuse_dev_open, |
| release: fuse_dev_release, |
| }; |
| |
| int fuse_dev_init() |
| { |
| int ret; |
| |
| proc_fs_fuse = NULL; |
| proc_fuse_dev = NULL; |
| |
| ret = -EIO; |
| proc_fs_fuse = proc_mkdir("fuse", proc_root_fs); |
| if(!proc_fs_fuse) { |
| printk("fuse: failed to create directory in /proc/fs\n"); |
| goto err; |
| } |
| |
| proc_fs_fuse->owner = THIS_MODULE; |
| proc_fuse_dev = create_proc_entry("dev", S_IFSOCK | S_IRUGO | S_IWUGO, |
| proc_fs_fuse); |
| if(!proc_fuse_dev) { |
| printk("fuse: failed to create entry in /proc/fs/fuse\n"); |
| goto err; |
| } |
| |
| proc_fuse_dev->proc_fops = &fuse_dev_operations; |
| |
| return 0; |
| |
| err: |
| fuse_dev_cleanup(); |
| return ret; |
| } |
| |
| void fuse_dev_cleanup() |
| { |
| if(proc_fs_fuse) { |
| remove_proc_entry("dev", proc_fs_fuse); |
| remove_proc_entry("fuse", proc_root_fs); |
| } |
| } |
| |
| /* |
| * Local Variables: |
| * indent-tabs-mode: t |
| * c-basic-offset: 8 |
| * End: |
| */ |