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[/] [or1k/] [tags/] [LINUX_2_4_26_OR32/] [linux/] [linux-2.4/] [fs/] [coda/] [psdev.c] - Rev 1279
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/* * An implementation of a loadable kernel mode driver providing * multiple kernel/user space bidirectional communications links. * * Author: Alan Cox <alan@redhat.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * * Adapted to become the Linux 2.0 Coda pseudo device * Peter Braam <braam@maths.ox.ac.uk> * Michael Callahan <mjc@emmy.smith.edu> * * Changes for Linux 2.1 * Copyright (c) 1997 Carnegie-Mellon University */ #include <linux/module.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/major.h> #include <linux/sched.h> #include <linux/lp.h> #include <linux/slab.h> #include <linux/ioport.h> #include <linux/fcntl.h> #include <linux/delay.h> #include <linux/skbuff.h> #include <linux/proc_fs.h> #include <linux/devfs_fs_kernel.h> #include <linux/vmalloc.h> #include <linux/fs.h> #include <linux/file.h> #include <linux/poll.h> #include <linux/init.h> #include <linux/list.h> #include <linux/smp_lock.h> #include <asm/io.h> #include <asm/system.h> #include <asm/poll.h> #include <asm/uaccess.h> #include <linux/coda.h> #include <linux/coda_linux.h> #include <linux/coda_fs_i.h> #include <linux/coda_psdev.h> #include <linux/coda_proc.h> #define upc_free(r) kfree(r) /* * Coda stuff */ extern struct file_system_type coda_fs_type; /* statistics */ int coda_hard; /* allows signals during upcalls */ unsigned long coda_timeout = 30; /* .. secs, then signals will dequeue */ struct venus_comm coda_comms[MAX_CODADEVS]; kmem_cache_t *cii_cache, *cred_cache, *upc_cache; /* * Device operations */ static unsigned int coda_psdev_poll(struct file *file, poll_table * wait) { struct venus_comm *vcp = (struct venus_comm *) file->private_data; unsigned int mask = POLLOUT | POLLWRNORM; poll_wait(file, &vcp->vc_waitq, wait); if (!list_empty(&vcp->vc_pending)) mask |= POLLIN | POLLRDNORM; return mask; } static int coda_psdev_ioctl(struct inode * inode, struct file * filp, unsigned int cmd, unsigned long arg) { unsigned int data; switch(cmd) { case CIOC_KERNEL_VERSION: data = CODA_KERNEL_VERSION; return put_user(data, (int *) arg); default: return -ENOTTY; } return 0; } /* * Receive a message written by Venus to the psdev */ static ssize_t coda_psdev_write(struct file *file, const char *buf, size_t nbytes, loff_t *off) { struct venus_comm *vcp = (struct venus_comm *) file->private_data; struct upc_req *req = NULL; struct upc_req *tmp; struct list_head *lh; struct coda_in_hdr hdr; ssize_t retval = 0, count = 0; int error; /* Peek at the opcode, uniquefier */ if (copy_from_user(&hdr, buf, 2 * sizeof(u_long))) return -EFAULT; CDEBUG(D_PSDEV, "(process,opc,uniq)=(%d,%ld,%ld), nbytes %ld\n", current->pid, hdr.opcode, hdr.unique, (long)nbytes); if (DOWNCALL(hdr.opcode)) { struct super_block *sb = NULL; union outputArgs *dcbuf; int size = sizeof(*dcbuf); sb = vcp->vc_sb; if ( !sb ) { CDEBUG(D_PSDEV, "coda_psdev_write: downcall, no SB!\n"); count = nbytes; goto out; } CDEBUG(D_PSDEV, "handling downcall\n"); if ( nbytes < sizeof(struct coda_out_hdr) ) { printk("coda_downcall opc %ld uniq %ld, not enough!\n", hdr.opcode, hdr.unique); count = nbytes; goto out; } if ( nbytes > size ) { printk("Coda: downcall opc %ld, uniq %ld, too much!", hdr.opcode, hdr.unique); nbytes = size; } CODA_ALLOC(dcbuf, union outputArgs *, nbytes); if (copy_from_user(dcbuf, buf, nbytes)) { CODA_FREE(dcbuf, nbytes); retval = -EFAULT; goto out; } /* what downcall errors does Venus handle ? */ lock_kernel(); error = coda_downcall(hdr.opcode, dcbuf, sb); unlock_kernel(); CODA_FREE(dcbuf, nbytes); if (error) { printk("psdev_write: coda_downcall error: %d\n", error); retval = error; goto out; } count = nbytes; goto out; } /* Look for the message on the processing queue. */ lock_kernel(); list_for_each(lh, &vcp->vc_processing) { tmp = list_entry(lh, struct upc_req , uc_chain); if (tmp->uc_unique == hdr.unique) { req = tmp; list_del(&req->uc_chain); break; } } unlock_kernel(); if (!req) { printk("psdev_write: msg (%ld, %ld) not found\n", hdr.opcode, hdr.unique); retval = -ESRCH; goto out; } CDEBUG(D_PSDEV,"Eureka: uniq %ld on queue!\n", hdr.unique); /* move data into response buffer. */ if (req->uc_outSize < nbytes) { printk("psdev_write: too much cnt: %d, cnt: %ld, opc: %ld, uniq: %ld.\n", req->uc_outSize, (long)nbytes, hdr.opcode, hdr.unique); nbytes = req->uc_outSize; /* don't have more space! */ } if (copy_from_user(req->uc_data, buf, nbytes)) { req->uc_flags |= REQ_ABORT; wake_up(&req->uc_sleep); retval = -EFAULT; goto out; } /* adjust outsize. is this useful ?? */ req->uc_outSize = nbytes; req->uc_flags |= REQ_WRITE; count = nbytes; /* Convert filedescriptor into a file handle */ if (req->uc_opcode == CODA_OPEN_BY_FD) { struct coda_open_by_fd_out *outp = (struct coda_open_by_fd_out *)req->uc_data; outp->fh = fget(outp->fd); } CDEBUG(D_PSDEV, "Found! Count %ld for (opc,uniq)=(%ld,%ld), upc_req at %p\n", (long)count, hdr.opcode, hdr.unique, &req); wake_up(&req->uc_sleep); out: return(count ? count : retval); } /* * Read a message from the kernel to Venus */ static ssize_t coda_psdev_read(struct file * file, char * buf, size_t nbytes, loff_t *off) { DECLARE_WAITQUEUE(wait, current); struct venus_comm *vcp = (struct venus_comm *) file->private_data; struct upc_req *req; ssize_t retval = 0, count = 0; if (nbytes == 0) return 0; lock_kernel(); add_wait_queue(&vcp->vc_waitq, &wait); set_current_state(TASK_INTERRUPTIBLE); while (list_empty(&vcp->vc_pending)) { if (file->f_flags & O_NONBLOCK) { retval = -EAGAIN; break; } if (signal_pending(current)) { retval = -ERESTARTSYS; break; } schedule(); } set_current_state(TASK_RUNNING); remove_wait_queue(&vcp->vc_waitq, &wait); if (retval) goto out; req = list_entry(vcp->vc_pending.next, struct upc_req,uc_chain); list_del(&req->uc_chain); /* Move the input args into userspace */ count = req->uc_inSize; if (nbytes < req->uc_inSize) { printk ("psdev_read: Venus read %ld bytes of %d in message\n", (long)nbytes, req->uc_inSize); count = nbytes; } if (copy_to_user(buf, req->uc_data, count)) retval = -EFAULT; /* If request was not a signal, enqueue and don't free */ if (!(req->uc_flags & REQ_ASYNC)) { req->uc_flags |= REQ_READ; list_add(&(req->uc_chain), vcp->vc_processing.prev); goto out; } CDEBUG(D_PSDEV, "vcread: signal msg (%d, %d)\n", req->uc_opcode, req->uc_unique); CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr)); upc_free(req); out: unlock_kernel(); return (count ? count : retval); } static int coda_psdev_open(struct inode * inode, struct file * file) { struct venus_comm *vcp; int idx; lock_kernel(); idx = MINOR(inode->i_rdev); if(idx >= MAX_CODADEVS) { unlock_kernel(); return -ENODEV; } vcp = &coda_comms[idx]; if(vcp->vc_inuse) { unlock_kernel(); return -EBUSY; } if (!vcp->vc_inuse++) { INIT_LIST_HEAD(&vcp->vc_pending); INIT_LIST_HEAD(&vcp->vc_processing); init_waitqueue_head(&vcp->vc_waitq); vcp->vc_sb = 0; vcp->vc_seq = 0; } file->private_data = vcp; CDEBUG(D_PSDEV, "device %i - inuse: %d\n", idx, vcp->vc_inuse); unlock_kernel(); return 0; } static int coda_psdev_release(struct inode * inode, struct file * file) { struct venus_comm *vcp = (struct venus_comm *) file->private_data; struct upc_req *req; struct list_head *lh, *next; lock_kernel(); if ( !vcp->vc_inuse ) { unlock_kernel(); printk("psdev_release: Not open.\n"); return -1; } CDEBUG(D_PSDEV, "psdev_release: inuse %d\n", vcp->vc_inuse); if (--vcp->vc_inuse) { unlock_kernel(); return 0; } /* Wakeup clients so they can return. */ CDEBUG(D_PSDEV, "wake up pending clients\n"); lh = vcp->vc_pending.next; next = lh; while ( (lh = next) != &vcp->vc_pending) { next = lh->next; req = list_entry(lh, struct upc_req, uc_chain); /* Async requests need to be freed here */ if (req->uc_flags & REQ_ASYNC) { CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr)); upc_free(req); continue; } req->uc_flags |= REQ_ABORT; wake_up(&req->uc_sleep); } lh = &vcp->vc_processing; CDEBUG(D_PSDEV, "wake up processing clients\n"); while ( (lh = lh->next) != &vcp->vc_processing) { req = list_entry(lh, struct upc_req, uc_chain); req->uc_flags |= REQ_ABORT; wake_up(&req->uc_sleep); } CDEBUG(D_PSDEV, "Done.\n"); unlock_kernel(); return 0; } static struct file_operations coda_psdev_fops = { owner: THIS_MODULE, read: coda_psdev_read, write: coda_psdev_write, poll: coda_psdev_poll, ioctl: coda_psdev_ioctl, open: coda_psdev_open, release: coda_psdev_release, }; static devfs_handle_t devfs_handle; static int init_coda_psdev(void) { if(devfs_register_chrdev(CODA_PSDEV_MAJOR,"coda_psdev", &coda_psdev_fops)) { printk(KERN_ERR "coda_psdev: unable to get major %d\n", CODA_PSDEV_MAJOR); return -EIO; } devfs_handle = devfs_mk_dir (NULL, "coda", NULL); devfs_register_series (devfs_handle, "%u", MAX_CODADEVS, DEVFS_FL_NONE, CODA_PSDEV_MAJOR, 0, S_IFCHR | S_IRUSR | S_IWUSR, &coda_psdev_fops, NULL); coda_sysctl_init(); return 0; } MODULE_AUTHOR("Peter J. Braam <braam@cs.cmu.edu>"); MODULE_LICENSE("GPL"); static int __init init_coda(void) { int status; printk(KERN_INFO "Coda Kernel/Venus communications, v5.3.18, coda@cs.cmu.edu\n"); status = init_coda_psdev(); if ( status ) { printk("Problem (%d) in init_coda_psdev\n", status); return status; } status = register_filesystem(&coda_fs_type); if (status) { printk("coda: failed to register filesystem!\n"); devfs_unregister(devfs_handle); devfs_unregister_chrdev(CODA_PSDEV_MAJOR,"coda_psdev"); coda_sysctl_clean(); } return status; } static void __exit exit_coda(void) { int err; err = unregister_filesystem(&coda_fs_type); if ( err != 0 ) { printk("coda: failed to unregister filesystem\n"); } devfs_unregister(devfs_handle); devfs_unregister_chrdev(CODA_PSDEV_MAJOR, "coda_psdev"); coda_sysctl_clean(); } module_init(init_coda); module_exit(exit_coda);
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