~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/coda/psdev.c

Version: ~ [ linux-5.7-rc7 ] ~ [ linux-5.6.14 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.42 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.124 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.181 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.224 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.224 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.84 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  *              An implementation of a loadable kernel mode driver providing
  3  *              multiple kernel/user space bidirectional communications links.
  4  *
  5  *              Author:         Alan Cox <alan@lxorguk.ukuu.org.uk>
  6  *
  7  *              This program is free software; you can redistribute it and/or
  8  *              modify it under the terms of the GNU General Public License
  9  *              as published by the Free Software Foundation; either version
 10  *              2 of the License, or (at your option) any later version.
 11  * 
 12  *              Adapted to become the Linux 2.0 Coda pseudo device
 13  *              Peter  Braam  <braam@maths.ox.ac.uk> 
 14  *              Michael Callahan <mjc@emmy.smith.edu>           
 15  *
 16  *              Changes for Linux 2.1
 17  *              Copyright (c) 1997 Carnegie-Mellon University
 18  */
 19 
 20 #include <linux/module.h>
 21 #include <linux/errno.h>
 22 #include <linux/kernel.h>
 23 #include <linux/major.h>
 24 #include <linux/time.h>
 25 #include <linux/sched.h>
 26 #include <linux/slab.h>
 27 #include <linux/ioport.h>
 28 #include <linux/fcntl.h>
 29 #include <linux/delay.h>
 30 #include <linux/skbuff.h>
 31 #include <linux/proc_fs.h>
 32 #include <linux/vmalloc.h>
 33 #include <linux/fs.h>
 34 #include <linux/file.h>
 35 #include <linux/poll.h>
 36 #include <linux/init.h>
 37 #include <linux/list.h>
 38 #include <linux/mutex.h>
 39 #include <linux/device.h>
 40 #include <linux/pid_namespace.h>
 41 #include <asm/io.h>
 42 #include <asm/poll.h>
 43 #include <asm/uaccess.h>
 44 
 45 #include <linux/coda.h>
 46 #include <linux/coda_psdev.h>
 47 
 48 #include "coda_linux.h"
 49 
 50 #include "coda_int.h"
 51 
 52 /* statistics */
 53 int           coda_hard;         /* allows signals during upcalls */
 54 unsigned long coda_timeout = 30; /* .. secs, then signals will dequeue */
 55 
 56 
 57 struct venus_comm coda_comms[MAX_CODADEVS];
 58 static struct class *coda_psdev_class;
 59 
 60 /*
 61  * Device operations
 62  */
 63 
 64 static unsigned int coda_psdev_poll(struct file *file, poll_table * wait)
 65 {
 66         struct venus_comm *vcp = (struct venus_comm *) file->private_data;
 67         unsigned int mask = POLLOUT | POLLWRNORM;
 68 
 69         poll_wait(file, &vcp->vc_waitq, wait);
 70         mutex_lock(&vcp->vc_mutex);
 71         if (!list_empty(&vcp->vc_pending))
 72                 mask |= POLLIN | POLLRDNORM;
 73         mutex_unlock(&vcp->vc_mutex);
 74 
 75         return mask;
 76 }
 77 
 78 static long coda_psdev_ioctl(struct file * filp, unsigned int cmd, unsigned long arg)
 79 {
 80         unsigned int data;
 81 
 82         switch(cmd) {
 83         case CIOC_KERNEL_VERSION:
 84                 data = CODA_KERNEL_VERSION;
 85                 return put_user(data, (int __user *) arg);
 86         default:
 87                 return -ENOTTY;
 88         }
 89 
 90         return 0;
 91 }
 92 
 93 /*
 94  *      Receive a message written by Venus to the psdev
 95  */
 96  
 97 static ssize_t coda_psdev_write(struct file *file, const char __user *buf, 
 98                                 size_t nbytes, loff_t *off)
 99 {
100         struct venus_comm *vcp = (struct venus_comm *) file->private_data;
101         struct upc_req *req = NULL;
102         struct upc_req *tmp;
103         struct list_head *lh;
104         struct coda_in_hdr hdr;
105         ssize_t retval = 0, count = 0;
106         int error;
107 
108         /* Peek at the opcode, uniquefier */
109         if (copy_from_user(&hdr, buf, 2 * sizeof(u_long)))
110                 return -EFAULT;
111 
112         if (DOWNCALL(hdr.opcode)) {
113                 union outputArgs *dcbuf;
114                 int size = sizeof(*dcbuf);
115 
116                 if  ( nbytes < sizeof(struct coda_out_hdr) ) {
117                         printk("coda_downcall opc %d uniq %d, not enough!\n",
118                                hdr.opcode, hdr.unique);
119                         count = nbytes;
120                         goto out;
121                 }
122                 if ( nbytes > size ) {
123                         printk("Coda: downcall opc %d, uniq %d, too much!",
124                                hdr.opcode, hdr.unique);
125                         nbytes = size;
126                 }
127                 CODA_ALLOC(dcbuf, union outputArgs *, nbytes);
128                 if (copy_from_user(dcbuf, buf, nbytes)) {
129                         CODA_FREE(dcbuf, nbytes);
130                         retval = -EFAULT;
131                         goto out;
132                 }
133 
134                 /* what downcall errors does Venus handle ? */
135                 error = coda_downcall(vcp, hdr.opcode, dcbuf);
136 
137                 CODA_FREE(dcbuf, nbytes);
138                 if (error) {
139                         printk("psdev_write: coda_downcall error: %d\n", error);
140                         retval = error;
141                         goto out;
142                 }
143                 count = nbytes;
144                 goto out;
145         }
146         
147         /* Look for the message on the processing queue. */
148         mutex_lock(&vcp->vc_mutex);
149         list_for_each(lh, &vcp->vc_processing) {
150                 tmp = list_entry(lh, struct upc_req , uc_chain);
151                 if (tmp->uc_unique == hdr.unique) {
152                         req = tmp;
153                         list_del(&req->uc_chain);
154                         break;
155                 }
156         }
157         mutex_unlock(&vcp->vc_mutex);
158 
159         if (!req) {
160                 printk("psdev_write: msg (%d, %d) not found\n", 
161                         hdr.opcode, hdr.unique);
162                 retval = -ESRCH;
163                 goto out;
164         }
165 
166         /* move data into response buffer. */
167         if (req->uc_outSize < nbytes) {
168                 printk("psdev_write: too much cnt: %d, cnt: %ld, opc: %d, uniq: %d.\n",
169                        req->uc_outSize, (long)nbytes, hdr.opcode, hdr.unique);
170                 nbytes = req->uc_outSize; /* don't have more space! */
171         }
172         if (copy_from_user(req->uc_data, buf, nbytes)) {
173                 req->uc_flags |= CODA_REQ_ABORT;
174                 wake_up(&req->uc_sleep);
175                 retval = -EFAULT;
176                 goto out;
177         }
178 
179         /* adjust outsize. is this useful ?? */
180         req->uc_outSize = nbytes;
181         req->uc_flags |= CODA_REQ_WRITE;
182         count = nbytes;
183 
184         /* Convert filedescriptor into a file handle */
185         if (req->uc_opcode == CODA_OPEN_BY_FD) {
186                 struct coda_open_by_fd_out *outp =
187                         (struct coda_open_by_fd_out *)req->uc_data;
188                 if (!outp->oh.result)
189                         outp->fh = fget(outp->fd);
190         }
191 
192         wake_up(&req->uc_sleep);
193 out:
194         return(count ? count : retval);  
195 }
196 
197 /*
198  *      Read a message from the kernel to Venus
199  */
200 
201 static ssize_t coda_psdev_read(struct file * file, char __user * buf, 
202                                size_t nbytes, loff_t *off)
203 {
204         DECLARE_WAITQUEUE(wait, current);
205         struct venus_comm *vcp = (struct venus_comm *) file->private_data;
206         struct upc_req *req;
207         ssize_t retval = 0, count = 0;
208 
209         if (nbytes == 0)
210                 return 0;
211 
212         mutex_lock(&vcp->vc_mutex);
213 
214         add_wait_queue(&vcp->vc_waitq, &wait);
215         set_current_state(TASK_INTERRUPTIBLE);
216 
217         while (list_empty(&vcp->vc_pending)) {
218                 if (file->f_flags & O_NONBLOCK) {
219                         retval = -EAGAIN;
220                         break;
221                 }
222                 if (signal_pending(current)) {
223                         retval = -ERESTARTSYS;
224                         break;
225                 }
226                 mutex_unlock(&vcp->vc_mutex);
227                 schedule();
228                 mutex_lock(&vcp->vc_mutex);
229         }
230 
231         set_current_state(TASK_RUNNING);
232         remove_wait_queue(&vcp->vc_waitq, &wait);
233 
234         if (retval)
235                 goto out;
236 
237         req = list_entry(vcp->vc_pending.next, struct upc_req,uc_chain);
238         list_del(&req->uc_chain);
239 
240         /* Move the input args into userspace */
241         count = req->uc_inSize;
242         if (nbytes < req->uc_inSize) {
243                 printk ("psdev_read: Venus read %ld bytes of %d in message\n",
244                         (long)nbytes, req->uc_inSize);
245                 count = nbytes;
246         }
247 
248         if (copy_to_user(buf, req->uc_data, count))
249                 retval = -EFAULT;
250         
251         /* If request was not a signal, enqueue and don't free */
252         if (!(req->uc_flags & CODA_REQ_ASYNC)) {
253                 req->uc_flags |= CODA_REQ_READ;
254                 list_add_tail(&(req->uc_chain), &vcp->vc_processing);
255                 goto out;
256         }
257 
258         CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
259         kfree(req);
260 out:
261         mutex_unlock(&vcp->vc_mutex);
262         return (count ? count : retval);
263 }
264 
265 static int coda_psdev_open(struct inode * inode, struct file * file)
266 {
267         struct venus_comm *vcp;
268         int idx, err;
269 
270         if (task_active_pid_ns(current) != &init_pid_ns)
271                 return -EINVAL;
272 
273         if (current_user_ns() != &init_user_ns)
274                 return -EINVAL;
275 
276         idx = iminor(inode);
277         if (idx < 0 || idx >= MAX_CODADEVS)
278                 return -ENODEV;
279 
280         err = -EBUSY;
281         vcp = &coda_comms[idx];
282         mutex_lock(&vcp->vc_mutex);
283 
284         if (!vcp->vc_inuse) {
285                 vcp->vc_inuse++;
286 
287                 INIT_LIST_HEAD(&vcp->vc_pending);
288                 INIT_LIST_HEAD(&vcp->vc_processing);
289                 init_waitqueue_head(&vcp->vc_waitq);
290                 vcp->vc_sb = NULL;
291                 vcp->vc_seq = 0;
292 
293                 file->private_data = vcp;
294                 err = 0;
295         }
296 
297         mutex_unlock(&vcp->vc_mutex);
298         return err;
299 }
300 
301 
302 static int coda_psdev_release(struct inode * inode, struct file * file)
303 {
304         struct venus_comm *vcp = (struct venus_comm *) file->private_data;
305         struct upc_req *req, *tmp;
306 
307         if (!vcp || !vcp->vc_inuse ) {
308                 printk("psdev_release: Not open.\n");
309                 return -1;
310         }
311 
312         mutex_lock(&vcp->vc_mutex);
313 
314         /* Wakeup clients so they can return. */
315         list_for_each_entry_safe(req, tmp, &vcp->vc_pending, uc_chain) {
316                 list_del(&req->uc_chain);
317 
318                 /* Async requests need to be freed here */
319                 if (req->uc_flags & CODA_REQ_ASYNC) {
320                         CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
321                         kfree(req);
322                         continue;
323                 }
324                 req->uc_flags |= CODA_REQ_ABORT;
325                 wake_up(&req->uc_sleep);
326         }
327 
328         list_for_each_entry_safe(req, tmp, &vcp->vc_processing, uc_chain) {
329                 list_del(&req->uc_chain);
330 
331                 req->uc_flags |= CODA_REQ_ABORT;
332                 wake_up(&req->uc_sleep);
333         }
334 
335         file->private_data = NULL;
336         vcp->vc_inuse--;
337         mutex_unlock(&vcp->vc_mutex);
338         return 0;
339 }
340 
341 
342 static const struct file_operations coda_psdev_fops = {
343         .owner          = THIS_MODULE,
344         .read           = coda_psdev_read,
345         .write          = coda_psdev_write,
346         .poll           = coda_psdev_poll,
347         .unlocked_ioctl = coda_psdev_ioctl,
348         .open           = coda_psdev_open,
349         .release        = coda_psdev_release,
350         .llseek         = noop_llseek,
351 };
352 
353 static int init_coda_psdev(void)
354 {
355         int i, err = 0;
356         if (register_chrdev(CODA_PSDEV_MAJOR, "coda", &coda_psdev_fops)) {
357               printk(KERN_ERR "coda_psdev: unable to get major %d\n", 
358                      CODA_PSDEV_MAJOR);
359               return -EIO;
360         }
361         coda_psdev_class = class_create(THIS_MODULE, "coda");
362         if (IS_ERR(coda_psdev_class)) {
363                 err = PTR_ERR(coda_psdev_class);
364                 goto out_chrdev;
365         }               
366         for (i = 0; i < MAX_CODADEVS; i++) {
367                 mutex_init(&(&coda_comms[i])->vc_mutex);
368                 device_create(coda_psdev_class, NULL,
369                               MKDEV(CODA_PSDEV_MAJOR, i), NULL, "cfs%d", i);
370         }
371         coda_sysctl_init();
372         goto out;
373 
374 out_chrdev:
375         unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
376 out:
377         return err;
378 }
379 
380 MODULE_AUTHOR("Jan Harkes, Peter J. Braam");
381 MODULE_DESCRIPTION("Coda Distributed File System VFS interface");
382 MODULE_ALIAS_CHARDEV_MAJOR(CODA_PSDEV_MAJOR);
383 MODULE_LICENSE("GPL");
384 MODULE_VERSION("6.6");
385 
386 static int __init init_coda(void)
387 {
388         int status;
389         int i;
390 
391         status = coda_init_inodecache();
392         if (status)
393                 goto out2;
394         status = init_coda_psdev();
395         if ( status ) {
396                 printk("Problem (%d) in init_coda_psdev\n", status);
397                 goto out1;
398         }
399         
400         status = register_filesystem(&coda_fs_type);
401         if (status) {
402                 printk("coda: failed to register filesystem!\n");
403                 goto out;
404         }
405         return 0;
406 out:
407         for (i = 0; i < MAX_CODADEVS; i++)
408                 device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
409         class_destroy(coda_psdev_class);
410         unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
411         coda_sysctl_clean();
412 out1:
413         coda_destroy_inodecache();
414 out2:
415         return status;
416 }
417 
418 static void __exit exit_coda(void)
419 {
420         int err, i;
421 
422         err = unregister_filesystem(&coda_fs_type);
423         if ( err != 0 ) {
424                 printk("coda: failed to unregister filesystem\n");
425         }
426         for (i = 0; i < MAX_CODADEVS; i++)
427                 device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
428         class_destroy(coda_psdev_class);
429         unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
430         coda_sysctl_clean();
431         coda_destroy_inodecache();
432 }
433 
434 module_init(init_coda);
435 module_exit(exit_coda);
436 
437 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp