psdev.c

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
    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@redhat.com>
    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/sched.h>
   25 #include <linux/lp.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/devfs_fs_kernel.h>
   33 #include <linux/vmalloc.h>
   34 #include <linux/fs.h>
   35 #include <linux/file.h>
   36 #include <linux/poll.h>
   37 #include <linux/init.h>
   38 #include <linux/list.h>
   39 #include <linux/smp_lock.h>
   40 #include <asm/io.h>
   41 #include <asm/system.h>
   42 #include <asm/poll.h>
   43 #include <asm/uaccess.h>
   44 
   45 #include <linux/coda.h>
   46 #include <linux/coda_linux.h>
   47 #include <linux/coda_fs_i.h>
   48 #include <linux/coda_psdev.h>
   49 #include <linux/coda_proc.h>
   50 
   51 #define upc_free(r) kfree(r)
   52 
   53 /* 
   54  * Coda stuff
   55  */
   56 extern struct file_system_type coda_fs_type;
   57 
   58 /* statistics */
   59 int           coda_hard;         /* allows signals during upcalls */
   60 unsigned long coda_timeout = 30; /* .. secs, then signals will dequeue */
   61 
   62 
   63 struct venus_comm coda_comms[MAX_CODADEVS];
   64 kmem_cache_t *cii_cache, *cred_cache, *upc_cache;
   65 
   66 /*
   67  * Device operations
   68  */
   69 
   70 static unsigned int coda_psdev_poll(struct file *file, poll_table * wait)
   71 {
   72         struct venus_comm *vcp = (struct venus_comm *) file->private_data;
   73         unsigned int mask = POLLOUT | POLLWRNORM;
   74 
   75         poll_wait(file, &vcp->vc_waitq, wait);
   76         if (!list_empty(&vcp->vc_pending))
   77                 mask |= POLLIN | POLLRDNORM;
   78 
   79         return mask;
   80 }
   81 
   82 static int coda_psdev_ioctl(struct inode * inode, struct file * filp, 
   83                             unsigned int cmd, unsigned long arg)
   84 {
   85         unsigned int data;
   86 
   87         switch(cmd) {
   88         case CIOC_KERNEL_VERSION:
   89                 data = CODA_KERNEL_VERSION;
   90                 return put_user(data, (int *) arg);
   91         default:
   92                 return -ENOTTY;
   93         }
   94 
   95         return 0;
   96 }
   97 
   98 /*
   99  *      Receive a message written by Venus to the psdev
  100  */
  101  
  102 static ssize_t coda_psdev_write(struct file *file, const char *buf, 
  103                                 size_t nbytes, loff_t *off)
  104 {
  105         struct venus_comm *vcp = (struct venus_comm *) file->private_data;
  106         struct upc_req *req = NULL;
  107         struct upc_req *tmp;
  108         struct list_head *lh;
  109         struct coda_in_hdr hdr;
  110         ssize_t retval = 0, count = 0;
  111         int error;
  112 
  113         /* Peek at the opcode, uniquefier */
  114         if (copy_from_user(&hdr, buf, 2 * sizeof(u_long)))
  115                 return -EFAULT;
  116 
  117         CDEBUG(D_PSDEV, "(process,opc,uniq)=(%d,%ld,%ld), nbytes %ld\n", 
  118                current->pid, hdr.opcode, hdr.unique, (long)nbytes);
  119 
  120         if (DOWNCALL(hdr.opcode)) {
  121                 struct super_block *sb = NULL;
  122                 union outputArgs *dcbuf;
  123                 int size = sizeof(*dcbuf);
  124 
  125                 sb = vcp->vc_sb;
  126                 if ( !sb ) {
  127                         CDEBUG(D_PSDEV, "coda_psdev_write: downcall, no SB!\n");
  128                         count = nbytes;
  129                         goto out;
  130                 }
  131                 CDEBUG(D_PSDEV, "handling downcall\n");
  132 
  133                 if  ( nbytes < sizeof(struct coda_out_hdr) ) {
  134                         printk("coda_downcall opc %ld uniq %ld, not enough!\n",
  135                                hdr.opcode, hdr.unique);
  136                         count = nbytes;
  137                         goto out;
  138                 }
  139                 if ( nbytes > size ) {
  140                         printk("Coda: downcall opc %ld, uniq %ld, too much!",
  141                                hdr.opcode, hdr.unique);
  142                         nbytes = size;
  143                 }
  144                 CODA_ALLOC(dcbuf, union outputArgs *, nbytes);
  145                 if (copy_from_user(dcbuf, buf, nbytes)) {
  146                         CODA_FREE(dcbuf, nbytes);
  147                         retval = -EFAULT;
  148                         goto out;
  149                 }
  150 
  151                 /* what downcall errors does Venus handle ? */
  152                 lock_kernel();
  153                 error = coda_downcall(hdr.opcode, dcbuf, sb);
  154                 unlock_kernel();
  155 
  156                 CODA_FREE(dcbuf, nbytes);
  157                 if (error) {
  158                         printk("psdev_write: coda_downcall error: %d\n", error);
  159                         retval = error;
  160                         goto out;
  161                 }
  162                 count = nbytes;
  163                 goto out;
  164         }
  165         
  166         /* Look for the message on the processing queue. */
  167         lock_kernel();
  168         list_for_each(lh, &vcp->vc_processing) {
  169                 tmp = list_entry(lh, struct upc_req , uc_chain);
  170                 if (tmp->uc_unique == hdr.unique) {
  171                         req = tmp;
  172                         list_del(&req->uc_chain);
  173                         break;
  174                 }
  175         }
  176         unlock_kernel();
  177 
  178         if (!req) {
  179                 printk("psdev_write: msg (%ld, %ld) not found\n", 
  180                         hdr.opcode, hdr.unique);
  181                 retval = -ESRCH;
  182                 goto out;
  183         }
  184 
  185         CDEBUG(D_PSDEV,"Eureka: uniq %ld on queue!\n", hdr.unique);
  186 
  187         /* move data into response buffer. */
  188         if (req->uc_outSize < nbytes) {
  189                 printk("psdev_write: too much cnt: %d, cnt: %ld, opc: %ld, uniq: %ld.\n",
  190                        req->uc_outSize, (long)nbytes, hdr.opcode, hdr.unique);
  191                 nbytes = req->uc_outSize; /* don't have more space! */
  192         }
  193         if (copy_from_user(req->uc_data, buf, nbytes)) {
  194                 req->uc_flags |= REQ_ABORT;
  195                 wake_up(&req->uc_sleep);
  196                 retval = -EFAULT;
  197                 goto out;
  198         }
  199 
  200         /* adjust outsize. is this useful ?? */
  201         req->uc_outSize = nbytes;       
  202         req->uc_flags |= REQ_WRITE;
  203         count = nbytes;
  204 
  205         /* Convert filedescriptor into a file handle */
  206         if (req->uc_opcode == CODA_OPEN_BY_FD) {
  207                 struct coda_open_by_fd_out *outp =
  208                         (struct coda_open_by_fd_out *)req->uc_data;
  209                 outp->fh = fget(outp->fd);
  210         }
  211 
  212         CDEBUG(D_PSDEV, 
  213                "Found! Count %ld for (opc,uniq)=(%ld,%ld), upc_req at %p\n", 
  214                 (long)count, hdr.opcode, hdr.unique, &req);
  215 
  216         wake_up(&req->uc_sleep);
  217 out:
  218         return(count ? count : retval);  
  219 }
  220 
  221 /*
  222  *      Read a message from the kernel to Venus
  223  */
  224 
  225 static ssize_t coda_psdev_read(struct file * file, char * buf, 
  226                                size_t nbytes, loff_t *off)
  227 {
  228         DECLARE_WAITQUEUE(wait, current);
  229         struct venus_comm *vcp = (struct venus_comm *) file->private_data;
  230         struct upc_req *req;
  231         ssize_t retval = 0, count = 0;
  232 
  233         if (nbytes == 0)
  234                 return 0;
  235 
  236         lock_kernel();
  237 
  238         add_wait_queue(&vcp->vc_waitq, &wait);
  239         set_current_state(TASK_INTERRUPTIBLE);
  240 
  241         while (list_empty(&vcp->vc_pending)) {
  242                 if (file->f_flags & O_NONBLOCK) {
  243                         retval = -EAGAIN;
  244                         break;
  245                 }
  246                 if (signal_pending(current)) {
  247                         retval = -ERESTARTSYS;
  248                         break;
  249                 }
  250                 schedule();
  251         }
  252 
  253         set_current_state(TASK_RUNNING);
  254         remove_wait_queue(&vcp->vc_waitq, &wait);
  255 
  256         if (retval)
  257                 goto out;
  258 
  259         req = list_entry(vcp->vc_pending.next, struct upc_req,uc_chain);
  260         list_del(&req->uc_chain);
  261 
  262         /* Move the input args into userspace */
  263         count = req->uc_inSize;
  264         if (nbytes < req->uc_inSize) {
  265                 printk ("psdev_read: Venus read %ld bytes of %d in message\n",
  266                         (long)nbytes, req->uc_inSize);
  267                 count = nbytes;
  268         }
  269 
  270         if (copy_to_user(buf, req->uc_data, count))
  271                 retval = -EFAULT;
  272         
  273         /* If request was not a signal, enqueue and don't free */
  274         if (!(req->uc_flags & REQ_ASYNC)) {
  275                 req->uc_flags |= REQ_READ;
  276                 list_add(&(req->uc_chain), vcp->vc_processing.prev);
  277                 goto out;
  278         }
  279 
  280         CDEBUG(D_PSDEV, "vcread: signal msg (%d, %d)\n", 
  281                         req->uc_opcode, req->uc_unique);
  282 
  283         CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
  284         upc_free(req);
  285 out:
  286         unlock_kernel();
  287         return (count ? count : retval);
  288 }
  289 
  290 static int coda_psdev_open(struct inode * inode, struct file * file)
  291 {
  292         struct venus_comm *vcp;
  293         int idx;
  294 
  295         lock_kernel();
  296         idx = MINOR(inode->i_rdev);
  297         if(idx >= MAX_CODADEVS) {
  298                 unlock_kernel();
  299                 return -ENODEV;
  300         }
  301 
  302         vcp = &coda_comms[idx];
  303         if(vcp->vc_inuse) {
  304                 unlock_kernel();
  305                 return -EBUSY;
  306         }
  307         
  308         if (!vcp->vc_inuse++) {
  309                 INIT_LIST_HEAD(&vcp->vc_pending);
  310                 INIT_LIST_HEAD(&vcp->vc_processing);
  311                 init_waitqueue_head(&vcp->vc_waitq);
  312                 vcp->vc_sb = 0;
  313                 vcp->vc_seq = 0;
  314         }
  315         
  316         file->private_data = vcp;
  317 
  318         CDEBUG(D_PSDEV, "device %i - inuse: %d\n", idx, vcp->vc_inuse);
  319 
  320         unlock_kernel();
  321         return 0;
  322 }
  323 
  324 
  325 static int coda_psdev_release(struct inode * inode, struct file * file)
  326 {
  327         struct venus_comm *vcp = (struct venus_comm *) file->private_data;
  328         struct upc_req *req;
  329         struct list_head *lh, *next;
  330 
  331         lock_kernel();
  332         if ( !vcp->vc_inuse ) {
  333                 unlock_kernel();
  334                 printk("psdev_release: Not open.\n");
  335                 return -1;
  336         }
  337 
  338         CDEBUG(D_PSDEV, "psdev_release: inuse %d\n", vcp->vc_inuse);
  339         if (--vcp->vc_inuse) {
  340                 unlock_kernel();
  341                 return 0;
  342         }
  343         
  344         /* Wakeup clients so they can return. */
  345         CDEBUG(D_PSDEV, "wake up pending clients\n");
  346         lh = vcp->vc_pending.next;
  347         next = lh;
  348         while ( (lh = next) != &vcp->vc_pending) {
  349                 next = lh->next;
  350                 req = list_entry(lh, struct upc_req, uc_chain);
  351                 /* Async requests need to be freed here */
  352                 if (req->uc_flags & REQ_ASYNC) {
  353                         CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
  354                         upc_free(req);
  355                         continue;
  356                 }
  357                 req->uc_flags |= REQ_ABORT;
  358                 wake_up(&req->uc_sleep);
  359         }
  360         
  361         lh = &vcp->vc_processing;
  362         CDEBUG(D_PSDEV, "wake up processing clients\n");
  363         while ( (lh = lh->next) != &vcp->vc_processing) {
  364                 req = list_entry(lh, struct upc_req, uc_chain);
  365                 req->uc_flags |= REQ_ABORT;
  366                 wake_up(&req->uc_sleep);
  367         }
  368         CDEBUG(D_PSDEV, "Done.\n");
  369 
  370         unlock_kernel();
  371         return 0;
  372 }
  373 
  374 
  375 static struct file_operations coda_psdev_fops = {
  376         owner:          THIS_MODULE,
  377         read:           coda_psdev_read,
  378         write:          coda_psdev_write,
  379         poll:           coda_psdev_poll,
  380         ioctl:          coda_psdev_ioctl,
  381         open:           coda_psdev_open,
  382         release:        coda_psdev_release,
  383 };
  384 
  385 static devfs_handle_t devfs_handle;
  386 
  387 static int init_coda_psdev(void)
  388 {
  389         if(devfs_register_chrdev(CODA_PSDEV_MAJOR,"coda_psdev",
  390                                  &coda_psdev_fops)) {
  391               printk(KERN_ERR "coda_psdev: unable to get major %d\n", 
  392                      CODA_PSDEV_MAJOR);
  393               return -EIO;
  394         }
  395         devfs_handle = devfs_mk_dir (NULL, "coda", NULL);
  396         devfs_register_series (devfs_handle, "%u", MAX_CODADEVS, DEVFS_FL_NONE,
  397                                CODA_PSDEV_MAJOR, 0,
  398                                S_IFCHR | S_IRUSR | S_IWUSR,
  399                                &coda_psdev_fops, NULL);
  400 
  401         coda_sysctl_init();
  402 
  403         return 0;
  404 }
  405 
  406 
  407 MODULE_AUTHOR("Peter J. Braam <braam@cs.cmu.edu>");
  408 MODULE_LICENSE("GPL");
  409 
  410 static int __init init_coda(void)
  411 {
  412         int status;
  413         printk(KERN_INFO "Coda Kernel/Venus communications, v5.3.18, coda@cs.cmu.edu\n");
  414 
  415         status = init_coda_psdev();
  416         if ( status ) {
  417                 printk("Problem (%d) in init_coda_psdev\n", status);
  418                 return status;
  419         }
  420         
  421         status = register_filesystem(&coda_fs_type);
  422         if (status) {
  423                 printk("coda: failed to register filesystem!\n");
  424                 devfs_unregister(devfs_handle);
  425                 devfs_unregister_chrdev(CODA_PSDEV_MAJOR,"coda_psdev");
  426                 coda_sysctl_clean();
  427         }
  428         return status;
  429 }
  430 
  431 static void __exit exit_coda(void)
  432 {
  433         int err;
  434 
  435         err = unregister_filesystem(&coda_fs_type);
  436         if ( err != 0 ) {
  437                 printk("coda: failed to unregister filesystem\n");
  438         }
  439         devfs_unregister(devfs_handle);
  440         devfs_unregister_chrdev(CODA_PSDEV_MAJOR, "coda_psdev");
  441         coda_sysctl_clean();
  442 }
  443 
  444 module_init(init_coda);
  445 module_exit(exit_coda);
  446
Cache object: 784d41afb3a8f9c6a5ba6ceec4f9fff9
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.
FreeBSD/Linux Kernel Cross Reference sys/fs/coda/psdev.c

FreeBSD/Linux Kernel Cross Reference
sys/fs/coda/psdev.c
