patch-2.4.15 linux/fs/intermezzo/psdev.c

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diff -u --recursive --new-file v2.4.14/linux/fs/intermezzo/psdev.c linux/fs/intermezzo/psdev.c
@@ -0,0 +1,1665 @@
+/*
+ *              An implementation of a loadable kernel mode driver providing
+ *              multiple kernel/user space bidirectional communications links.
+ *
+ *              Author:         Alan Cox <alan@cymru.net>
+ *
+ *              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
+ *
+ *              Redone again for InterMezzo
+ *              Copyright (c) 1998 Peter J. Braam
+ *              Copyright (c) 2000 Mountain View Data, Inc.
+ *              Copyright (c) 2000 Tacitus Systems, Inc.
+ *              Copyright (c) 2001 Cluster File Systems, Inc.
+ *
+ *		Extended attribute support
+ *		Copyright (c) 2001 Shirish. H. Phatak
+ *		Copyright (c) 2001 Tacit Networks, Inc.
+ */
+
+
+#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/vmalloc.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <asm/io.h>
+#include <asm/segment.h>
+#include <asm/system.h>
+#include <asm/poll.h>
+#include <asm/uaccess.h>
+
+#include <linux/intermezzo_fs.h>
+#include <linux/intermezzo_upcall.h>
+#include <linux/intermezzo_psdev.h>
+#include <linux/intermezzo_kml.h>
+
+
+#ifdef PRESTO_DEVEL
+int  presto_print_entry = 1;
+int  presto_debug = 4095;
+#else
+int  presto_print_entry = 0;
+int  presto_debug = 0;
+#endif
+
+/* Like inode.c (presto_sym_iops), the initializer is just to prevent
+   upc_comms from appearing as a COMMON symbol (and therefore
+   interfering with other modules that use the same variable name. */
+struct upc_comm upc_comms[MAX_PRESTODEV] = {{0}};
+
+/*
+ * Device operations: map file to upcall structure
+ */
+static inline struct upc_comm *presto_psdev_f2u(struct file *file)
+{
+        int minor;
+
+        if ( MAJOR(file->f_dentry->d_inode->i_rdev) != PRESTO_PSDEV_MAJOR ) {
+                EXIT;
+                return NULL;
+        }
+
+        minor = MINOR(file->f_dentry->d_inode->i_rdev);
+        if ( minor < 0 || minor >= MAX_PRESTODEV ) {
+                EXIT;
+                return NULL;
+        }
+
+        return &(upc_comms[minor]);
+}
+
+inline int presto_lento_up(int minor) 
+{
+        return upc_comms[minor].uc_pid;
+}
+
+
+static unsigned int presto_psdev_poll(struct file *file, poll_table * wait)
+{
+        struct upc_comm *upccom;
+        unsigned int mask = POLLOUT | POLLWRNORM;
+        /* ENTRY; this will flood you */
+
+        if ( ! (upccom = presto_psdev_f2u(file)) ) {
+                kdev_t dev = file->f_dentry->d_inode->i_rdev;
+                printk("InterMezzo: %s, bad device %s\n",
+                       __FUNCTION__, kdevname(dev));
+        }
+
+        poll_wait(file, &(upccom->uc_waitq), wait);
+
+        if (!list_empty(&upccom->uc_pending)) {
+                CDEBUG(D_PSDEV, "Non-empty pending list.\n");
+                mask |= POLLIN | POLLRDNORM;
+        }
+
+        /* EXIT; will flood you */
+        return mask;
+}
+
+
+
+/*
+ *      Receive a message written by Lento to the psdev
+ */
+static ssize_t presto_psdev_write(struct file *file, const char *buf,
+                                  size_t count, loff_t *off)
+{
+        struct upc_comm *upccom;
+        struct upc_req *req = NULL;
+        struct upc_req *tmp;
+        struct list_head *lh;
+        struct lento_down_hdr hdr;
+        int error;
+
+        if ( ! (upccom = presto_psdev_f2u(file)) ) {
+                kdev_t dev = file->f_dentry->d_inode->i_rdev;
+                printk("InterMezzo: %s, bad device %s\n",
+                       __FUNCTION__, kdevname(dev));
+        }
+
+        /* Peek at the opcode, uniquefier */
+        if ( count < sizeof(hdr) ) {
+              printk("presto_psdev_write: Lento didn't write full hdr.\n");
+                return -EINVAL;
+        }
+
+        error = copy_from_user(&hdr, buf, sizeof(hdr));
+        if ( error )
+                return error;
+
+        CDEBUG(D_PSDEV, "(process,opc,uniq)=(%d,%d,%d)\n",
+               current->pid, hdr.opcode, hdr.unique);
+
+        /* Look for the message on the processing queue. */
+        lh  = &upccom->uc_processing;
+        while ( (lh = lh->next) != &upccom->uc_processing ) {
+                tmp = list_entry(lh, struct upc_req , rq_chain);
+                if (tmp->rq_unique == hdr.unique) {
+                        req = tmp;
+                      /* unlink here: keeps search length minimal */
+                        list_del(&req->rq_chain);
+                      INIT_LIST_HEAD(&req->rq_chain);
+                        CDEBUG(D_PSDEV,"Eureka opc %d uniq %d!\n",
+                               hdr.opcode, hdr.unique);
+                        break;
+                }
+        }
+        if (!req) {
+                printk("psdev_write: msg (%d, %d) not found\n",
+                       hdr.opcode, hdr.unique);
+                return(-ESRCH);
+        }
+
+        /* move data into response buffer. */
+        if (req->rq_bufsize < count) {
+                printk("psdev_write: too much cnt: %d, cnt: %d, "
+                       "opc: %d, uniq: %d.\n",
+                       req->rq_bufsize, count, hdr.opcode, hdr.unique);
+                count = req->rq_bufsize; /* don't have more space! */
+        }
+        error = copy_from_user(req->rq_data, buf, count);
+        if ( error )
+                return error;
+
+        /* adjust outsize: good upcalls can be aware of this */
+        req->rq_rep_size = count;
+        req->rq_flags |= REQ_WRITE;
+
+        wake_up(&req->rq_sleep);
+        return(count);
+}
+
+/*
+ *      Read a message from the kernel to Lento
+ */
+static ssize_t presto_psdev_read(struct file * file, char * buf,
+                                 size_t count, loff_t *off)
+{
+        struct upc_comm *upccom;
+        struct upc_req *req;
+        int result = count;
+
+        if ( ! (upccom = presto_psdev_f2u(file)) ) {
+                kdev_t dev = file->f_dentry->d_inode->i_rdev;
+                printk("InterMezzo: %s, bad device %s\n",
+                       __FUNCTION__, kdevname(dev));
+        }
+
+        CDEBUG(D_PSDEV, "count %d\n", count);
+        if (list_empty(&(upccom->uc_pending))) {
+                CDEBUG(D_UPCALL, "Empty pending list in read, not good\n");
+                return -EINVAL;
+        }
+
+        req = list_entry((upccom->uc_pending.next), struct upc_req, rq_chain);
+        list_del(&(req->rq_chain));
+      if (! (req->rq_flags & REQ_ASYNC) ) {
+              list_add(&(req->rq_chain), upccom->uc_processing.prev);
+      }
+      req->rq_flags |= REQ_READ;
+
+        /* Move the input args into userspace */
+        if (req->rq_bufsize <= count) {
+                result = req->rq_bufsize;
+        }
+
+        if (count < req->rq_bufsize) {
+                printk ("psdev_read: buffer too small, read %d of %d bytes\n",
+                        count, req->rq_bufsize);
+        }
+
+        if ( copy_to_user(buf, req->rq_data, result) ) {
+                return -EFAULT;
+        }
+
+        /* If request was asynchronous don't enqueue, but free */
+        if (req->rq_flags & REQ_ASYNC) {
+                CDEBUG(D_PSDEV, "psdev_read: async msg (%d, %d), result %d\n",
+                       req->rq_opcode, req->rq_unique, result);
+                PRESTO_FREE(req->rq_data, req->rq_bufsize);
+                PRESTO_FREE(req, sizeof(*req));
+                return result;
+        }
+
+        return result;
+}
+
+static int presto_psdev_ioctl(struct inode *inode, struct file *file,
+                              unsigned int cmd, unsigned long arg)
+{
+        struct upc_comm *upccom;
+        /* XXX is this rdev or dev? */
+        kdev_t dev = inode->i_rdev;
+
+        ENTRY;
+        upccom = presto_psdev_f2u(file);
+        if ( !upccom) {
+                printk("InterMezzo: %s, bad device %s\n",
+                       __FUNCTION__, kdevname(dev));
+                EXIT;
+                return -ENODEV;
+        }
+
+        switch(cmd) {
+
+        case TCGETS:
+                return -EINVAL;
+
+        case PRESTO_GETMOUNT: {
+                /* return all the mounts for this device.  */
+                int minor = 0;
+                int len, outlen;
+                struct readmount readmount;
+                struct readmount *user_readmount = (struct readmount *) arg;
+                char * tmp;
+                int error;
+
+                error = copy_from_user(&readmount, (void *)arg,
+                                       sizeof(readmount));
+                if ( error )  {
+                        printk("psdev: can't copy %d bytes from %p to %p\n",
+                                sizeof(readmount), (struct readmount *) arg,
+                                &readmount);
+                        EXIT;
+                        return error;
+                }
+
+                len = readmount.io_len;
+                minor = MINOR(dev);
+                PRESTO_ALLOC(tmp, char *, len);
+                if (!tmp) {
+                        EXIT;
+                        return -ENOMEM;
+                }
+
+                outlen = presto_sprint_mounts(tmp, len, minor);
+                CDEBUG(D_PSDEV, "presto_sprint_mounts returns %d bytes\n",
+                                outlen);
+
+                /* as this came out on 1/3/2000, it could NEVER work.
+                 * So fix it ... RGM
+                 * I mean, let's let the compiler do a little work ...
+                 * gcc suggested the extra ()
+                 */
+                error = copy_to_user(readmount.io_string, tmp, outlen);
+                if ( error ) {
+                        CDEBUG(D_PSDEV, "Copy_to_user string 0x%p failed\n",
+                               readmount.io_string);
+                }
+                if ((!error) && (error = copy_to_user(&(user_readmount->io_len),
+                                                      &outlen, sizeof(int))) ) {
+                        CDEBUG(D_PSDEV, "Copy_to_user len @0x%p failed\n",
+                               &(user_readmount->io_len));
+                }
+
+                PRESTO_FREE(tmp, len);
+                EXIT;
+                return error;
+        }
+
+        case PRESTO_SETPID: {
+                /*
+                 * This ioctl is performed by each Lento that starts up
+                 * and wants to do further communication with presto.
+                 */
+                CDEBUG(D_PSDEV, "Setting current pid to %d\n", current->pid);
+                upccom->uc_pid = current->pid;
+                if ( !list_empty(&upccom->uc_processing) ) {
+                        struct list_head *lh;
+                        struct upc_req *req;
+                        printk("WARNING: setpid & processing not empty!\n");
+                        lh = &upccom->uc_processing;
+                        while ( (lh = lh->next) != &upccom->uc_processing) {
+                                req = list_entry(lh, struct upc_req, rq_chain);
+                                /* freeing of req and data is done by the sleeper */
+                                wake_up(&req->rq_sleep);
+                        }
+                }
+                if ( !list_empty(&upccom->uc_processing) ) {
+                        printk("BAD: FAILDED TO CLEAN PROCESSING LIST!\n");
+                }
+                EXIT;
+                return 0;
+        }
+
+        case PRESTO_CLEAR_FSETROOT: {
+                /*
+                 * Close KML files.
+                 */
+                int error;
+                int saved_pid = upccom->uc_pid;
+                char *path;
+                struct {
+                        char *path;
+                        int   path_len;
+                } input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+
+                PRESTO_ALLOC(path, char *, input.path_len + 1);
+                if ( !path ) {
+                        EXIT;
+                        return -ENOMEM;
+                }
+                error = copy_from_user(path, input.path, input.path_len);
+                if ( error ) {
+                        PRESTO_FREE(path, input.path_len + 1);
+                        EXIT;
+                        return error;
+                }
+                path[input.path_len] = '\0';
+                CDEBUG(D_PSDEV, "clear_fsetroot: path %s\n", path);
+
+                upccom->uc_pid = current->pid;
+                error = presto_clear_fsetroot(path);
+                upccom->uc_pid = saved_pid;
+                PRESTO_FREE(path, input.path_len + 1);
+                EXIT;
+                return error;
+        }
+
+
+        case PRESTO_CLEAR_ALL_FSETROOTS: {
+                /*
+                 * Close KML files.
+                 */
+                int error;
+                int saved_pid = upccom->uc_pid;
+                char *path;
+                struct {
+                        char *path;
+                        int   path_len;
+                } input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+
+                PRESTO_ALLOC(path, char *, input.path_len + 1);
+                if ( !path ) {
+                        EXIT;
+                        return -ENOMEM;
+                }
+                error = copy_from_user(path, input.path, input.path_len);
+                if ( error ) {
+                        PRESTO_FREE(path, input.path_len + 1);
+                        EXIT;
+                        return error;
+                }
+                path[input.path_len] = '\0';
+                CDEBUG(D_PSDEV, "clear_all_fsetroot: path %s\n", path);
+
+                upccom->uc_pid = current->pid;
+                error = presto_clear_all_fsetroots(path);
+                upccom->uc_pid = saved_pid;
+                PRESTO_FREE(path, input.path_len + 1);
+                EXIT;
+                return error;
+        }
+
+        case PRESTO_GET_KMLSIZE: {
+                int error;
+                int saved_pid = upccom->uc_pid;
+                char *path;
+                size_t size = 0;
+                struct {
+                        __u64 size;
+                        char *path;
+                        int   path_len;
+                } input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+
+                PRESTO_ALLOC(path, char *, input.path_len + 1);
+                if ( !path ) {
+                        EXIT;
+                        return -ENOMEM;
+                }
+                error = copy_from_user(path, input.path, input.path_len);
+                if ( error ) {
+                        PRESTO_FREE(path, input.path_len + 1);
+                        EXIT;
+                        return error;
+                }
+                path[input.path_len] = '\0';
+                CDEBUG(D_PSDEV, "get_kmlsize: len %d path %s\n", 
+                       input.path_len, path);
+
+                upccom->uc_pid = current->pid;
+                error = presto_get_kmlsize(path, &size);
+                PRESTO_FREE(path, input.path_len + 1);
+                if (error) {
+                        EXIT;
+                        return error;
+                }
+                input.size = size;
+                upccom->uc_pid = saved_pid;
+
+                CDEBUG(D_PSDEV, "get_kmlsize: size = %d\n", size);
+
+                EXIT;
+                return copy_to_user((char *)arg, &input, sizeof(input));
+        }
+
+        case PRESTO_GET_RECNO: {
+                int error;
+                int saved_pid = upccom->uc_pid;
+                char *path;
+                off_t recno = 0;
+                struct {
+                        __u64 recno;
+                        char *path;
+                        int   path_len;
+                } input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+
+                PRESTO_ALLOC(path, char *, input.path_len + 1);
+                if ( !path ) {
+                        EXIT;
+                        return -ENOMEM;
+                }
+                error = copy_from_user(path, input.path, input.path_len);
+                if ( error ) {
+                        PRESTO_FREE(path, input.path_len + 1);
+                        EXIT;
+                        return error;
+                }
+                path[input.path_len] = '\0';
+                CDEBUG(D_PSDEV, "get_recno: len %d path %s\n", 
+                       input.path_len, path);
+
+                upccom->uc_pid = current->pid;
+                error = presto_get_lastrecno(path, &recno);
+                PRESTO_FREE(path, input.path_len + 1);
+                if (error) {
+                        EXIT;
+                        return error;
+                }
+                input.recno = recno;
+                upccom->uc_pid = saved_pid;
+
+                CDEBUG(D_PSDEV, "get_recno: recno = %d\n", (int) recno);
+
+                EXIT;
+                return copy_to_user((char *)arg, &input, sizeof(input));
+        }
+
+        case PRESTO_SET_FSETROOT: {
+                /*
+                 * Save information about the cache, and initialize "special"
+                 * cache files (KML, etc).
+                 */
+                int error;
+                int saved_pid = upccom->uc_pid;
+                char *fsetname;
+                char *path;
+                struct {
+                        char *path;
+                        int   path_len;
+                        char *name;
+                        int   name_len;
+                        int   id;
+                        int   flags;
+                } input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+
+                PRESTO_ALLOC(path, char *, input.path_len + 1);
+                if ( !path ) {
+                        EXIT;
+                        return -ENOMEM;
+                }
+                error = copy_from_user(path, input.path, input.path_len);
+                if ( error ) {
+                        EXIT;
+                        goto exit_free_path;
+                }
+                path[input.path_len] = '\0';
+
+                PRESTO_ALLOC(fsetname, char *, input.name_len + 1);
+                if ( !fsetname ) {
+                        error = -ENOMEM;
+                        EXIT;
+                        goto exit_free_path;
+                }
+                error = copy_from_user(fsetname, input.name, input.name_len);
+                if ( error ) {
+                        EXIT;
+                        goto exit_free_fsetname;
+                }
+                fsetname[input.name_len] = '\0';
+
+                CDEBUG(D_PSDEV,
+                       "set_fsetroot: path %s name %s, id %d, flags %x\n",
+                       path, fsetname, input.id, input.flags);
+                upccom->uc_pid = current->pid;
+                error = presto_set_fsetroot(path, fsetname, input.id,input.flags);
+                upccom->uc_pid = saved_pid;
+                if ( error ) {
+                        EXIT;
+                        goto exit_free_fsetname;
+                }
+                /* fsetname is kept in the fset, so don't free it now */
+                PRESTO_FREE(path, input.path_len + 1);
+                EXIT;
+                return 0;
+
+        exit_free_fsetname:
+                PRESTO_FREE(fsetname, input.name_len + 1);
+        exit_free_path:
+                PRESTO_FREE(path, input.path_len + 1);
+                return error;
+        }
+
+        case PRESTO_CLOSE_JOURNALF: {
+                int saved_pid = upccom->uc_pid;
+                int error;
+
+                CDEBUG(D_SUPER, "HELLO\n");
+
+                /* pretend we are lento: we should lock something */
+                upccom->uc_pid = current->pid;
+                error = presto_close_journal_file(NULL);
+                CDEBUG(D_PSDEV, "error is %d\n", error);
+                upccom->uc_pid = saved_pid;
+                EXIT;
+                return error;
+        }
+
+        case PRESTO_GETOPT:
+        case PRESTO_SETOPT: {
+                /* return all the mounts for this device.  */
+                int dosetopt(int, struct psdev_opt *);
+                int dogetopt(int, struct psdev_opt *);
+                int minor = 0;
+                struct psdev_opt kopt;
+                struct psdev_opt *user_opt = (struct psdev_opt *) arg;
+                int error;
+
+                error = copy_from_user(&kopt, (void *)arg, sizeof(kopt));
+                if ( error )  {
+                        printk("psdev: can't copyin %d bytes from %p to %p\n",
+                               sizeof(kopt), (struct kopt *) arg, &kopt);
+                        EXIT;
+                        return error;
+                }
+                minor = MINOR(dev);
+                if (cmd == PRESTO_SETOPT)
+                        error = dosetopt(minor, &kopt);
+
+                if ( error ) {
+                        CDEBUG(D_PSDEV,
+                               "dosetopt failed minor %d, opt %d, val %d\n",
+                               minor, kopt.optname, kopt.optval);
+                        EXIT;
+                        return error;
+                }
+
+                error = dogetopt(minor, &kopt);
+
+                if ( error ) {
+                        CDEBUG(D_PSDEV,
+                               "dogetopt failed minor %d, opt %d, val %d\n",
+                               minor, kopt.optname, kopt.optval);
+                        EXIT;
+                        return error;
+                }
+
+                error = copy_to_user(user_opt, &kopt, sizeof(kopt));
+                if ( error ) {
+                        CDEBUG(D_PSDEV, "Copy_to_user opt 0x%p failed\n",
+                               user_opt);
+                        EXIT;
+                        return error;
+                }
+                CDEBUG(D_PSDEV, "dosetopt minor %d, opt %d, val %d return %d\n",
+                         minor, kopt.optname, kopt.optval, error);
+                EXIT;
+                return 0;
+        }
+
+        case PRESTO_VFS_SETATTR: {
+                int error;
+                struct lento_input_attr input;
+                struct iattr iattr;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+                iattr.ia_valid = input.valid;
+                iattr.ia_mode  = (umode_t)input.mode;
+                iattr.ia_uid   = (uid_t)input.uid;
+                iattr.ia_gid   = (gid_t)input.gid;
+                iattr.ia_size  = (off_t)input.size;
+                iattr.ia_atime = (time_t)input.atime;
+                iattr.ia_mtime = (time_t)input.mtime;
+                iattr.ia_ctime = (time_t)input.ctime;
+                iattr.ia_attr_flags = input.attr_flags;
+
+                error = lento_setattr(input.name, &iattr, &input.info);
+                EXIT;
+                return error;
+        }
+
+        case PRESTO_VFS_CREATE: {
+                int error;
+                struct lento_input_mode input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+
+                error = lento_create(input.name, input.mode, &input.info);
+                EXIT;
+                return error;
+        }
+
+        case PRESTO_VFS_LINK: {
+                int error;
+                struct lento_input_old_new input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+
+                error = lento_link(input.oldname, input.newname, &input.info);
+                EXIT;
+                return error;
+        }
+
+        case PRESTO_VFS_UNLINK: {
+                int error;
+                struct lento_input input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+
+                error = lento_unlink(input.name, &input.info);
+                EXIT;
+                return error;
+        }
+
+        case PRESTO_VFS_SYMLINK: {
+                int error;
+                struct lento_input_old_new input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+
+                error = lento_symlink(input.oldname, input.newname,&input.info);
+                EXIT;
+                return error;
+        }
+
+        case PRESTO_VFS_MKDIR: {
+                int error;
+                struct lento_input_mode input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+
+                error = lento_mkdir(input.name, input.mode, &input.info);
+                EXIT;
+                return error;
+        }
+
+        case PRESTO_VFS_RMDIR: {
+                int error;
+                struct lento_input input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+
+                error = lento_rmdir(input.name, &input.info);
+                EXIT;
+                return error;
+        }
+
+        case PRESTO_VFS_MKNOD: {
+                int error;
+                struct lento_input_dev input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+
+                error = lento_mknod(input.name, input.mode,
+                                    MKDEV(input.major,input.minor),&input.info);
+                EXIT;
+                return error;
+        }
+
+        case PRESTO_VFS_RENAME: {
+                int error;
+                struct lento_input_old_new input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+
+                error = lento_rename(input.oldname, input.newname, &input.info);
+                EXIT;
+                return error;
+        }
+
+#ifdef CONFIG_FS_EXT_ATTR
+        /* IOCTL to create/modify an extended attribute */
+        case PRESTO_VFS_SETEXTATTR: {
+                int error;
+                struct lento_input_ext_attr input;
+                char *name;
+                char *buffer;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) { 
+                    EXIT;
+                    return error;
+                }
+
+                /* Now setup the input parameters */
+                PRESTO_ALLOC(name, char *, input.name_len+1);
+                /* We need null terminated strings for attr names */
+                name[input.name_len] = '\0';
+                error=copy_from_user(name, input.name, input.name_len);
+                if ( error ) { 
+                    EXIT;
+                    PRESTO_FREE(name,input.name_len+1);
+                    return error;
+                }
+
+                PRESTO_ALLOC(buffer, char *, input.buffer_len+1);
+                error=copy_from_user(buffer, input.buffer, input.buffer_len);
+                if ( error ) { 
+                    EXIT;
+                    PRESTO_FREE(name,input.name_len+1);
+                    PRESTO_FREE(buffer,input.buffer_len+1);
+                    return error;
+                }
+                /* Make null terminated for easy printing */
+                buffer[input.buffer_len]='\0';
+ 
+                CDEBUG(D_PSDEV," setextattr params: name %s, valuelen %d,"
+                       " value %s, attr flags %x, mode %o, slot offset %d,"
+                       " recno %d, kml offset %lu, flags %x, time %d\n", 
+                       name, input.buffer_len, buffer, input.flags, input.mode,
+                       input.info.slot_offset, input.info.recno,
+                       (unsigned long) input.info.kml_offset, input.info.flags,
+                       input.info.updated_time);
+
+                error=lento_set_ext_attr
+                      (input.path,name,buffer,input.buffer_len,
+                       input.flags, input.mode, &input.info);
+
+                PRESTO_FREE(name,input.name_len+1);
+                PRESTO_FREE(buffer,input.buffer_len+1);
+                EXIT;
+                return error;
+        }
+
+        /* IOCTL to delete an extended attribute */
+        case PRESTO_VFS_DELEXTATTR: {
+                int error;
+                struct lento_input_ext_attr input;
+                char *name;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) { 
+                    EXIT;
+                    return error;
+                }
+
+                /* Now setup the input parameters */
+                PRESTO_ALLOC(name, char *, input.name_len+1);
+                /* We need null terminated strings for attr names */
+                name[input.name_len] = '\0';
+                error=copy_from_user(name, input.name, input.name_len);
+                if ( error ) { 
+                    EXIT;
+                    PRESTO_FREE(name,input.name_len+1);
+                    return error;
+                }
+
+                CDEBUG(D_PSDEV," delextattr params: name %s,"
+                       " attr flags %x, mode %o, slot offset %d, recno %d,"
+                       " kml offset %lu, flags %x, time %d\n", 
+                       name, input.flags, input.mode,
+                       input.info.slot_offset, input.info.recno,
+                       (unsigned long) input.info.kml_offset, input.info.flags,
+                       input.info.updated_time);
+
+                error=lento_set_ext_attr
+                      (input.path,name,NULL,0,input.flags,
+                       input.mode,&input.info);
+                PRESTO_FREE(name,input.name_len+1);
+                EXIT;
+                return error;
+        }
+#endif
+
+        case PRESTO_VFS_IOPEN: {
+                struct lento_input_iopen input;
+                int error;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+
+                input.fd = lento_iopen(input.name, (ino_t)input.ino,
+                                       input.generation, input.flags);
+                CDEBUG(D_PIOCTL, "lento_iopen file descriptor: %d\n", input.fd);
+                if (input.fd < 0) {
+                        EXIT;
+                        return input.fd;
+                }
+                EXIT;
+                return copy_to_user((char *)arg, &input, sizeof(input));
+        }
+
+        case PRESTO_VFS_CLOSE: {
+                int error;
+                struct lento_input_close input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+
+                CDEBUG(D_PIOCTL, "lento_close file descriptor: %d\n", input.fd);
+                error = lento_close(input.fd, &input.info);
+                EXIT;
+                return error;
+        }
+
+        case PRESTO_BACKFETCH_LML: {
+                char *user_path;
+                int error;
+                struct lml_arg {
+                        char *path;
+                        __u32 path_len;
+                        __u64 remote_ino;
+                        __u32 remote_generation;
+                        __u32 remote_version;
+                        struct presto_version remote_file_version;
+                } input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+                user_path = input.path;
+
+                PRESTO_ALLOC(input.path, char *, input.path_len + 1);
+                if ( !input.path ) {
+                        EXIT;
+                        return -ENOMEM;
+                }
+                error = copy_from_user(input.path, user_path, input.path_len);
+                if ( error ) {
+                        EXIT;
+                        PRESTO_FREE(input.path, input.path_len + 1);
+                        return error;
+                }
+                input.path[input.path_len] = '\0';
+
+                CDEBUG(D_DOWNCALL, "lml name: %s\n", input.path);
+                
+                return lento_write_lml(input.path, 
+                                       input.remote_ino, 
+                                       input.remote_generation,
+                                       input.remote_version,
+                                       &input.remote_file_version); 
+
+        }
+                
+
+        case PRESTO_CANCEL_LML: {
+                char *user_path;
+                int error;
+                struct lml_arg {
+                        char *path;
+                        __u64 lml_offset; 
+                        __u32 path_len;
+                        __u64 remote_ino;
+                        __u32 remote_generation;
+                        __u32 remote_version;
+                        struct lento_vfs_context info;
+                } input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+                user_path = input.path;
+
+                PRESTO_ALLOC(input.path, char *, input.path_len + 1);
+                if ( !input.path ) {
+                        EXIT;
+                        return -ENOMEM;
+                }
+                error = copy_from_user(input.path, user_path, input.path_len);
+                if ( error ) {
+                        EXIT;
+                        PRESTO_FREE(input.path, input.path_len + 1);
+                        return error;
+                }
+                input.path[input.path_len] = '\0';
+
+                CDEBUG(D_DOWNCALL, "lml name: %s\n", input.path);
+                
+                return lento_cancel_lml(input.path, 
+                                        input.lml_offset, 
+                                        input.remote_ino, 
+                                        input.remote_generation,
+                                        input.remote_version,
+                                        &input.info); 
+
+        }
+
+        case PRESTO_COMPLETE_CLOSES: {
+                char *user_path;
+                int error;
+                struct lml_arg {
+                        char *path;
+                        __u32 path_len;
+                } input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+                user_path = input.path;
+
+                PRESTO_ALLOC(input.path, char *, input.path_len + 1);
+                if ( !input.path ) {
+                        EXIT;
+                        return -ENOMEM;
+                }
+                error = copy_from_user(input.path, user_path, input.path_len);
+                if ( error ) {
+                        EXIT;
+                        PRESTO_FREE(input.path, input.path_len + 1);
+                        return error;
+                }
+                input.path[input.path_len] = '\0';
+
+                CDEBUG(D_DOWNCALL, "lml name: %s\n", input.path);
+                
+                error = lento_complete_closes(input.path);
+                PRESTO_FREE(input.path, input.path_len + 1);
+                return error;
+        }
+
+        case PRESTO_RESET_FSET: {
+                char *user_path;
+                int error;
+                struct lml_arg {
+                        char *path;
+                        __u32 path_len;
+                        __u64 offset;
+                        __u32 recno;
+                } input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+                user_path = input.path;
+
+                PRESTO_ALLOC(input.path, char *, input.path_len + 1);
+                if ( !input.path ) {
+                        EXIT;
+                        return -ENOMEM;
+                }
+                error = copy_from_user(input.path, user_path, input.path_len);
+                if ( error ) {
+                        EXIT;
+                        PRESTO_FREE(input.path, input.path_len + 1);
+                        return error;
+                }
+                input.path[input.path_len] = '\0';
+
+                CDEBUG(D_DOWNCALL, "lml name: %s\n", input.path);
+                
+                return lento_reset_fset(input.path, input.offset, input.recno); 
+
+        }
+                
+
+        case PRESTO_MARK: {
+                char *user_path;
+                int res = 0;  /* resulting flags - returned to user */
+                int error;
+                struct {
+                        int  mark_what;
+                        int  and_flag;
+                        int  or_flag;
+                        int path_len;
+                        char *path;
+                } input;
+
+                error = copy_from_user(&input, (char *)arg, sizeof(input));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                }
+                user_path = input.path;
+
+                PRESTO_ALLOC(input.path, char *, input.path_len + 1);
+                if ( !input.path ) {
+                        EXIT;
+                        return -ENOMEM;
+                }
+                error = copy_from_user(input.path, user_path, input.path_len);
+                if ( error ) {
+                        EXIT;
+                        PRESTO_FREE(input.path, input.path_len + 1);
+                        return error;
+                }
+                input.path[input.path_len] = '\0';
+
+                CDEBUG(D_DOWNCALL, "mark name: %s, and: %x, or: %x, what %d\n",
+                       input.path, input.and_flag, input.or_flag, 
+                       input.mark_what);
+
+                switch (input.mark_what) {
+                case MARK_DENTRY:               
+                        error = presto_mark_dentry(input.path,
+                                                   input.and_flag,
+                                                   input.or_flag, &res);
+                        break;
+                case MARK_FSET:
+                        error = presto_mark_fset(input.path,
+                                                   input.and_flag,
+                                                   input.or_flag, &res);
+                        break;
+                case MARK_CACHE:
+                        error = presto_mark_cache(input.path,
+                                                   input.and_flag,
+                                                   input.or_flag, &res);
+                        break;
+                case MARK_GETFL: {
+                        int fflags, cflags;
+                        input.and_flag = 0xffffffff;
+                        input.or_flag = 0; 
+                        error = presto_mark_dentry(input.path,
+                                                   input.and_flag,
+                                                   input.or_flag, &res);
+                        if (error) 
+                                break;
+                        error = presto_mark_fset(input.path,
+                                                   input.and_flag,
+                                                   input.or_flag, &fflags);
+                        if (error) 
+                                break;
+                        error = presto_mark_cache(input.path,
+                                                   input.and_flag,
+                                                   input.or_flag, &cflags);
+
+                        if (error) 
+                                break;
+                        input.and_flag = fflags;
+                        input.or_flag = cflags;
+                	break;
+                }
+                default:
+                        error = -EINVAL;
+                }
+
+                PRESTO_FREE(input.path, input.path_len + 1);
+                if (error == -EBUSY) {
+                        input.and_flag = error;
+                        error = 0;
+                }
+                if (error) { 
+                        EXIT;
+                        return error;
+                }
+                /* return the correct cookie to wait for */
+                input.mark_what = res;
+                return copy_to_user((char *)arg, &input, sizeof(input));
+        }
+
+#ifdef  CONFIG_KREINT
+        case PRESTO_REINT_BEGIN:
+                return begin_kml_reint (file, arg);
+        case PRESTO_DO_REINT:
+                return do_kml_reint (file, arg);
+        case PRESTO_REINT_END:
+                return end_kml_reint (file, arg);
+#endif
+
+        case PRESTO_RELEASE_PERMIT: {
+                int error;
+                char *user_path;
+                struct {
+                        int  cookie;
+                        int path_len;
+                        char *path;
+                } permit;
+                
+                error = copy_from_user(&permit, (char *)arg, sizeof(permit));
+                if ( error ) {
+                        EXIT;
+                        return error;
+                        }
+                user_path = permit.path;
+                
+                PRESTO_ALLOC(permit.path, char *, permit.path_len + 1);
+                if ( !permit.path ) {
+                        EXIT;
+                        return -ENOMEM;
+                }
+                error = copy_from_user(permit.path, user_path, permit.path_len);
+                if ( error ) {
+                        EXIT;
+                        PRESTO_FREE(permit.path, permit.path_len + 1);
+                        return error;
+                }
+                permit.path[permit.path_len] = '\0';
+                
+                CDEBUG(D_DOWNCALL, "release permit: %s, in cookie=%d\n",
+                       permit.path, permit.cookie);
+                error = presto_permit_downcall(permit.path, &permit.cookie);
+                
+                PRESTO_FREE(permit.path, permit.path_len + 1);
+                if (error) {
+                        EXIT;
+                        return error;
+                }
+                /* return the correct cookie to wait for */
+                return copy_to_user((char *)arg, &permit, sizeof(permit));
+        }
+        
+        default:
+                CDEBUG(D_PSDEV, "bad ioctl 0x%x, \n", cmd);
+                CDEBUG(D_PSDEV, "valid are 0x%x - 0x%x, 0x%x - 0x%x \n",
+                        PRESTO_GETMOUNT, PRESTO_GET_KMLSIZE,
+                        PRESTO_VFS_SETATTR, PRESTO_VFS_IOPEN);
+                EXIT;
+        }
+
+        return -EINVAL;
+}
+
+
+static int presto_psdev_open(struct inode * inode, struct file * file)
+{
+         struct upc_comm *upccom;
+         ENTRY;
+
+         if ( ! (upccom = presto_psdev_f2u(file)) ) {
+                 kdev_t dev = file->f_dentry->d_inode->i_rdev;
+                 printk("InterMezzo: %s, bad device %s\n",
+                        __FUNCTION__, kdevname(dev));
+                 EXIT;
+                 return -EINVAL;
+         }
+
+        MOD_INC_USE_COUNT;
+
+        CDEBUG(D_PSDEV, "Psdev_open: uc_pid: %d, caller: %d, flags: %d\n",
+               upccom->uc_pid, current->pid, file->f_flags);
+
+        EXIT;
+        return 0;
+}
+
+
+
+static int presto_psdev_release(struct inode * inode, struct file * file)
+{
+        struct upc_comm *upccom;
+        struct upc_req *req;
+        struct list_head *lh;
+        ENTRY;
+
+
+        if ( ! (upccom = presto_psdev_f2u(file)) ) {
+                kdev_t dev = file->f_dentry->d_inode->i_rdev;
+                printk("InterMezzo: %s, bad device %s\n",
+                       __FUNCTION__, kdevname(dev));
+        }
+
+        if ( upccom->uc_pid != current->pid ) {
+                printk("psdev_release: Not lento.\n");
+                MOD_DEC_USE_COUNT;
+                return 0;
+        }
+
+        MOD_DEC_USE_COUNT;
+        CDEBUG(D_PSDEV, "Lento: pid %d\n", current->pid);
+        upccom->uc_pid = 0;
+
+        /* Wake up clients so they can return. */
+        CDEBUG(D_PSDEV, "Wake up clients sleeping for pending.\n");
+        lh = &upccom->uc_pending;
+        while ( (lh = lh->next) != &upccom->uc_pending) {
+                req = list_entry(lh, struct upc_req, rq_chain);
+
+                /* Async requests stay around for a new lento */
+                if (req->rq_flags & REQ_ASYNC) {
+                        continue;
+                }
+                /* the sleeper will free the req and data */
+                req->rq_flags |= REQ_DEAD; 
+                wake_up(&req->rq_sleep);
+        }
+
+        CDEBUG(D_PSDEV, "Wake up clients sleeping for processing\n");
+        lh = &upccom->uc_processing;
+        while ( (lh = lh->next) != &upccom->uc_processing) {
+                req = list_entry(lh, struct upc_req, rq_chain);
+                /* freeing of req and data is done by the sleeper */
+                req->rq_flags |= REQ_DEAD; 
+                wake_up(&req->rq_sleep);
+        }
+        CDEBUG(D_PSDEV, "Done.\n");
+
+        EXIT;
+        return 0;
+}
+
+static struct file_operations presto_psdev_fops = {
+        read:    presto_psdev_read,
+        write:   presto_psdev_write,
+        poll:    presto_psdev_poll,
+        ioctl:   presto_psdev_ioctl,
+        open:    presto_psdev_open,
+        release: presto_psdev_release
+};
+
+
+int  presto_psdev_init(void)
+{
+        int i;
+
+#ifdef PRESTO_DEVEL
+        if (register_chrdev(PRESTO_PSDEV_MAJOR, "intermezzo_psdev_devel",
+                           &presto_psdev_fops)) {
+                printk(KERN_ERR "presto_psdev: unable to get major %d\n",
+                       PRESTO_PSDEV_MAJOR);
+                return -EIO;
+        }
+#else
+        if (register_chrdev(PRESTO_PSDEV_MAJOR, "intermezzo_psdev",
+                           &presto_psdev_fops)) {
+                printk("presto_psdev: unable to get major %d\n",
+                       PRESTO_PSDEV_MAJOR);
+                return -EIO;
+        }
+#endif
+
+        memset(&upc_comms, 0, sizeof(upc_comms));
+        for ( i = 0 ; i < MAX_PRESTODEV ; i++ ) {
+                char *name;
+                struct upc_comm *psdev = &upc_comms[i];
+                INIT_LIST_HEAD(&psdev->uc_pending);
+                INIT_LIST_HEAD(&psdev->uc_processing);
+                INIT_LIST_HEAD(&psdev->uc_cache_list);
+                init_waitqueue_head(&psdev->uc_waitq);
+                psdev->uc_hard = 0;
+                psdev->uc_no_filter = 0;
+                psdev->uc_no_journal = 0;
+                psdev->uc_no_upcall = 0;
+                psdev->uc_timeout = 30;
+                psdev->uc_errorval = 0;
+                psdev->uc_minor = i;
+                PRESTO_ALLOC(name, char *, strlen(PRESTO_PSDEV_NAME "256")+1);
+                if (!name) { 
+                        printk("Unable to allocate memory for device name\n");
+                        continue;
+                }
+                sprintf(name, PRESTO_PSDEV_NAME "%d", i); 
+                psdev->uc_devname = name;
+        }
+        return 0;
+}
+
+void presto_psdev_cleanup(void)
+{
+        int i;
+
+        for ( i = 0 ; i < MAX_PRESTODEV ; i++ ) {
+                struct upc_comm *psdev = &upc_comms[i];
+                struct list_head *lh;
+
+                if ( ! list_empty(&psdev->uc_pending)) { 
+                        printk("Weird, tell Peter: module cleanup and pending list not empty dev %d\n", i);
+                }
+                if ( ! list_empty(&psdev->uc_processing)) { 
+                        printk("Weird, tell Peter: module cleanup and processing list not empty dev %d\n", i);
+                }
+                if ( ! list_empty(&psdev->uc_cache_list)) { 
+                        printk("Weird, tell Peter: module cleanup and cache listnot empty dev %d\n", i);
+                }
+                if (psdev->uc_devname) {
+                        PRESTO_FREE(psdev->uc_devname,
+                                    strlen(PRESTO_PSDEV_NAME "256")+1);
+                }
+                lh = psdev->uc_pending.next;
+                while ( lh != &psdev->uc_pending) {
+                        struct upc_req *req;
+
+                        req = list_entry(lh, struct upc_req, rq_chain);
+                        lh = lh->next;
+                        if ( req->rq_flags & REQ_ASYNC ) {
+                                list_del(&(req->rq_chain));
+                                CDEBUG(D_UPCALL, "free pending upcall type %d\n",
+                                       req->rq_opcode);
+                                PRESTO_FREE(req->rq_data, req->rq_bufsize);
+                                PRESTO_FREE(req, sizeof(struct upc_req));
+                        } else {
+                                req->rq_flags |= REQ_DEAD; 
+                                wake_up(&req->rq_sleep);
+                        }
+                }
+                lh = &psdev->uc_processing;
+                while ( (lh = lh->next) != &psdev->uc_processing ) {
+                        struct upc_req *req;
+                        req = list_entry(lh, struct upc_req, rq_chain);
+                        list_del(&(req->rq_chain));
+                        req->rq_flags |= REQ_DEAD; 
+                        wake_up(&req->rq_sleep);
+                }
+        }
+}
+
+/*
+ * lento_upcall and lento_downcall routines
+ */
+static inline unsigned long lento_waitfor_upcall(struct upc_req *req,
+                                                 int minor)
+{
+        DECLARE_WAITQUEUE(wait, current);
+        unsigned long posttime;
+
+        req->rq_posttime = posttime = jiffies;
+
+        add_wait_queue(&req->rq_sleep, &wait);
+        for (;;) {
+                if ( upc_comms[minor].uc_hard == 0 )
+                        current->state = TASK_INTERRUPTIBLE;
+                else
+                        current->state = TASK_UNINTERRUPTIBLE;
+
+                /* got a reply */
+                if ( req->rq_flags & (REQ_WRITE | REQ_DEAD) )
+                        break;
+
+                if ( !upc_comms[minor].uc_hard && signal_pending(current) ) {
+                        /* if this process really wants to die, let it go */
+                        if (sigismember(&(current->pending.signal), SIGKILL)||
+                            sigismember(&(current->pending.signal), SIGINT) )
+                                break;
+                        /* signal is present: after timeout always return
+                           really smart idea, probably useless ... */
+                        if ( jiffies > req->rq_posttime +
+                             upc_comms[minor].uc_timeout * HZ )
+                                break;
+                }
+                schedule();
+
+        }
+      list_del(&req->rq_chain); 
+      INIT_LIST_HEAD(&req->rq_chain); 
+        remove_wait_queue(&req->rq_sleep, &wait);
+        current->state = TASK_RUNNING;
+
+        CDEBUG(D_SPECIAL, "posttime: %ld, returned: %ld\n",
+               posttime, jiffies-posttime);
+        return  (jiffies - posttime);
+
+}
+
+/*
+ * lento_upcall will return an error in the case of
+ * failed communication with Lento _or_ will peek at Lento
+ * reply and return Lento's error.
+ *
+ * As lento has 2 types of errors, normal errors (positive) and internal
+ * errors (negative), normal errors are negated, while internal errors
+ * are all mapped to -EINTR, while showing a nice warning message. (jh)
+ *
+ * lento_upcall will always free buffer, either directly, when an upcall
+ * is read (in presto_psdev_read), when the filesystem is unmounted, or
+ * when the module is unloaded.
+ */
+int lento_upcall(int minor, int bufsize, int *rep_size, union up_args *buffer,
+                 int async, struct upc_req *rq)
+{
+        unsigned long runtime;
+        struct upc_comm *upc_commp;
+        union down_args *out;
+        struct upc_req *req;
+        int error = 0;
+
+        ENTRY;
+        upc_commp = &(upc_comms[minor]);
+
+        if (upc_commp->uc_no_upcall) {
+                EXIT;
+                goto exit_buf;
+        }
+        if (!upc_commp->uc_pid && !async) {
+                EXIT;
+                error = -ENXIO;
+                goto exit_buf;
+        }
+
+        /* Format the request message. */
+        CDEBUG(D_UPCALL, "buffer at %p, size %d\n", buffer, bufsize);
+        PRESTO_ALLOC(req, struct upc_req *, sizeof(struct upc_req));
+        if ( !req ) {
+                EXIT;
+                error = -ENOMEM;
+                goto exit_buf;
+        }
+        req->rq_data = (void *)buffer;
+        req->rq_flags = 0;
+        req->rq_bufsize = bufsize;
+        req->rq_rep_size = 0;
+        req->rq_opcode = ((union up_args *)buffer)->uh.opcode;
+        req->rq_unique = ++upc_commp->uc_seq;
+        init_waitqueue_head(&req->rq_sleep);
+
+        /* Fill in the common input args. */
+        ((union up_args *)buffer)->uh.unique = req->rq_unique;
+        /* Append msg to pending queue and poke Lento. */
+        list_add(&req->rq_chain, upc_commp->uc_pending.prev);
+        CDEBUG(D_UPCALL,
+               "Proc %d waking Lento %d for(opc,uniq) =(%d,%d) msg at %p.\n",
+               current->pid, upc_commp->uc_pid, req->rq_opcode,
+               req->rq_unique, req);
+
+        wake_up_interruptible(&upc_commp->uc_waitq);
+
+        if ( async ) {
+                req->rq_flags = REQ_ASYNC;
+                if( rq != NULL ) {
+                        *rq = *req; /* struct copying */
+                }
+                /* req, rq_data are freed in presto_psdev_read for async */
+                EXIT;
+                return 0;
+        }
+
+        /* We can be interrupted while we wait for Lento to process
+         * our request.  If the interrupt occurs before Lento has read
+         * the request, we dequeue and return. If it occurs after the
+         * read but before the reply, we dequeue, send a signal
+         * message, and return. If it occurs after the reply we ignore
+         * it. In no case do we want to restart the syscall.  If it
+         * was interrupted by a lento shutdown (psdev_close), return
+         * ENODEV.  */
+
+        /* Go to sleep.  Wake up on signals only after the timeout. */
+        runtime = lento_waitfor_upcall(req, minor);
+
+        CDEBUG(D_TIMING, "opc: %d time: %ld uniq: %d size: %d\n",
+               req->rq_opcode, jiffies - req->rq_posttime,
+               req->rq_unique, req->rq_rep_size);
+        CDEBUG(D_UPCALL,
+               "..process %d woken up by Lento for req at 0x%x, data at %x\n",
+               current->pid, (int)req, (int)req->rq_data);
+
+        if (upc_commp->uc_pid) {      /* i.e. Lento is still alive */
+          /* Op went through, interrupt or not we go on */
+            if (req->rq_flags & REQ_WRITE) {
+                    out = (union down_args *)req->rq_data;
+                    /* here we map positive Lento errors to kernel errors */
+                    if ( out->dh.result < 0 ) {
+                            printk("Tell Peter: Lento returns negative error %d, for oc %d!\n",
+                                   out->dh.result, out->dh.opcode);
+                          out->dh.result = EINVAL;
+                    }
+                    error = -out->dh.result;
+                    CDEBUG(D_UPCALL, "upcall: (u,o,r) (%d, %d, %d) out at %p\n",
+                           out->dh.unique, out->dh.opcode, out->dh.result, out);
+                    *rep_size = req->rq_rep_size;
+                    EXIT;
+                    goto exit_req;
+            }
+            /* Interrupted before lento read it. */
+            if ( !(req->rq_flags & REQ_READ) && signal_pending(current)) {
+                    CDEBUG(D_UPCALL,
+                           "Interrupt before read: (op,un)=(%d,%d), flags %x\n",
+                           req->rq_opcode, req->rq_unique, req->rq_flags);
+                    /* perhaps the best way to convince the app to give up? */
+                    error = -EINTR;
+                    EXIT;
+                    goto exit_req;
+            }
+
+            /* interrupted after Lento did its read, send signal */
+            if ( (req->rq_flags & REQ_READ) && signal_pending(current) ) {
+                    union up_args *sigargs;
+                    struct upc_req *sigreq;
+
+                    CDEBUG(D_UPCALL,"Sending for: op = %d.%d, flags = %x\n",
+                           req->rq_opcode, req->rq_unique, req->rq_flags);
+
+                    error = -EINTR;
+
+                    /* req, rq_data are freed in presto_psdev_read for async */
+                    PRESTO_ALLOC(sigreq, struct upc_req *,
+                                 sizeof (struct upc_req));
+                    if (!sigreq) {
+                            error = -ENOMEM;
+                            EXIT;
+                            goto exit_req;
+                    }
+                    PRESTO_ALLOC((sigreq->rq_data), char *,
+                                 sizeof(struct lento_up_hdr));
+                    if (!(sigreq->rq_data)) {
+                            PRESTO_FREE(sigreq, sizeof (struct upc_req));
+                            error = -ENOMEM;
+                            EXIT;
+                            goto exit_req;
+                    }
+
+                    sigargs = (union up_args *)sigreq->rq_data;
+                    sigargs->uh.opcode = LENTO_SIGNAL;
+                    sigargs->uh.unique = req->rq_unique;
+
+                    sigreq->rq_flags = REQ_ASYNC;
+                    sigreq->rq_opcode = sigargs->uh.opcode;
+                    sigreq->rq_unique = sigargs->uh.unique;
+                    sigreq->rq_bufsize = sizeof(struct lento_up_hdr);
+                    sigreq->rq_rep_size = 0;
+                    CDEBUG(D_UPCALL,
+                           "presto_upcall: enqueing signal msg (%d, %d)\n",
+                           sigreq->rq_opcode, sigreq->rq_unique);
+
+                    /* insert at head of queue! */
+                    list_add(&sigreq->rq_chain, &upc_commp->uc_pending);
+                    wake_up_interruptible(&upc_commp->uc_waitq);
+            } else {
+                  printk("Lento: Strange interruption - tell Peter.\n");
+                    error = -EINTR;
+            }
+        } else {        /* If lento died i.e. !UC_OPEN(upc_commp) */
+                printk("presto_upcall: Lento dead on (op,un) (%d.%d) flags %d\n",
+                       req->rq_opcode, req->rq_unique, req->rq_flags);
+                error = -ENODEV;
+        }
+
+exit_req:
+        PRESTO_FREE(req, sizeof(struct upc_req));
+exit_buf:
+        PRESTO_FREE(buffer, bufsize);
+        return error;
+}
+
+

FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)