Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 814 insertions, 0 deletions

diff --git a/fs/orangefs/devorangefs-req.c b/fs/orangefs/devorangefs-req.c
new file mode 100644
index 000000000..33ee8cb32
--- /dev/null
+++ b/fs/orangefs/devorangefs-req.c
@@ -0,0 +1,814 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * Changes by Acxiom Corporation to add protocol version to kernel
+ * communication, Copyright Acxiom Corporation, 2005.
+ *
+ * See COPYING in top-level directory.
+ */
+
+#include "protocol.h"
+#include "orangefs-kernel.h"
+#include "orangefs-dev-proto.h"
+#include "orangefs-bufmap.h"
+#include "orangefs-debugfs.h"
+
+#include <linux/debugfs.h>
+#include <linux/slab.h>
+
+/* this file implements the /dev/pvfs2-req device node */
+
+uint32_t orangefs_userspace_version;
+
+static int open_access_count;
+
+static DEFINE_MUTEX(devreq_mutex);
+
+#define DUMP_DEVICE_ERROR()                                                   \
+do {                                                                          \
+	gossip_err("*****************************************************\n");\
+	gossip_err("ORANGEFS Device Error:  You cannot open the device file ");  \
+	gossip_err("\n/dev/%s more than once.  Please make sure that\nthere " \
+		   "are no ", ORANGEFS_REQDEVICE_NAME);                          \
+	gossip_err("instances of a program using this device\ncurrently "     \
+		   "running. (You must verify this!)\n");                     \
+	gossip_err("For example, you can use the lsof program as follows:\n");\
+	gossip_err("'lsof | grep %s' (run this as root)\n",                   \
+		   ORANGEFS_REQDEVICE_NAME);                                     \
+	gossip_err("  open_access_count = %d\n", open_access_count);          \
+	gossip_err("*****************************************************\n");\
+} while (0)
+
+static int hash_func(__u64 tag, int table_size)
+{
+	return do_div(tag, (unsigned int)table_size);
+}
+
+static void orangefs_devreq_add_op(struct orangefs_kernel_op_s *op)
+{
+	int index = hash_func(op->tag, hash_table_size);
+
+	list_add_tail(&op->list, &orangefs_htable_ops_in_progress[index]);
+}
+
+/*
+ * find the op with this tag and remove it from the in progress
+ * hash table.
+ */
+static struct orangefs_kernel_op_s *orangefs_devreq_remove_op(__u64 tag)
+{
+	struct orangefs_kernel_op_s *op, *next;
+	int index;
+
+	index = hash_func(tag, hash_table_size);
+
+	spin_lock(&orangefs_htable_ops_in_progress_lock);
+	list_for_each_entry_safe(op,
+				 next,
+				 &orangefs_htable_ops_in_progress[index],
+				 list) {
+		if (op->tag == tag && !op_state_purged(op) &&
+		    !op_state_given_up(op)) {
+			list_del_init(&op->list);
+			spin_unlock(&orangefs_htable_ops_in_progress_lock);
+			return op;
+		}
+	}
+
+	spin_unlock(&orangefs_htable_ops_in_progress_lock);
+	return NULL;
+}
+
+/* Returns whether any FS are still pending remounted */
+static int mark_all_pending_mounts(void)
+{
+	int unmounted = 1;
+	struct orangefs_sb_info_s *orangefs_sb = NULL;
+
+	spin_lock(&orangefs_superblocks_lock);
+	list_for_each_entry(orangefs_sb, &orangefs_superblocks, list) {
+		/* All of these file system require a remount */
+		orangefs_sb->mount_pending = 1;
+		unmounted = 0;
+	}
+	spin_unlock(&orangefs_superblocks_lock);
+	return unmounted;
+}
+
+/*
+ * Determine if a given file system needs to be remounted or not
+ *  Returns -1 on error
+ *           0 if already mounted
+ *           1 if needs remount
+ */
+static int fs_mount_pending(__s32 fsid)
+{
+	int mount_pending = -1;
+	struct orangefs_sb_info_s *orangefs_sb = NULL;
+
+	spin_lock(&orangefs_superblocks_lock);
+	list_for_each_entry(orangefs_sb, &orangefs_superblocks, list) {
+		if (orangefs_sb->fs_id == fsid) {
+			mount_pending = orangefs_sb->mount_pending;
+			break;
+		}
+	}
+	spin_unlock(&orangefs_superblocks_lock);
+	return mount_pending;
+}
+
+static int orangefs_devreq_open(struct inode *inode, struct file *file)
+{
+	int ret = -EINVAL;
+
+	/* in order to ensure that the filesystem driver sees correct UIDs */
+	if (file->f_cred->user_ns != &init_user_ns) {
+		gossip_err("%s: device cannot be opened outside init_user_ns\n",
+			   __func__);
+		goto out;
+	}
+
+	if (!(file->f_flags & O_NONBLOCK)) {
+		gossip_err("%s: device cannot be opened in blocking mode\n",
+			   __func__);
+		goto out;
+	}
+	ret = -EACCES;
+	gossip_debug(GOSSIP_DEV_DEBUG, "client-core: opening device\n");
+	mutex_lock(&devreq_mutex);
+
+	if (open_access_count == 0) {
+		open_access_count = 1;
+		ret = 0;
+	} else {
+		DUMP_DEVICE_ERROR();
+	}
+	mutex_unlock(&devreq_mutex);
+
+out:
+
+	gossip_debug(GOSSIP_DEV_DEBUG,
+		     "pvfs2-client-core: open device complete (ret = %d)\n",
+		     ret);
+	return ret;
+}
+
+/* Function for read() callers into the device */
+static ssize_t orangefs_devreq_read(struct file *file,
+				 char __user *buf,
+				 size_t count, loff_t *offset)
+{
+	struct orangefs_kernel_op_s *op, *temp;
+	__s32 proto_ver = ORANGEFS_KERNEL_PROTO_VERSION;
+	static __s32 magic = ORANGEFS_DEVREQ_MAGIC;
+	struct orangefs_kernel_op_s *cur_op;
+	unsigned long ret;
+
+	/* We do not support blocking IO. */
+	if (!(file->f_flags & O_NONBLOCK)) {
+		gossip_err("%s: blocking read from client-core.\n",
+			   __func__);
+		return -EINVAL;
+	}
+
+	/*
+	 * The client will do an ioctl to find MAX_DEV_REQ_UPSIZE, then
+	 * always read with that size buffer.
+	 */
+	if (count != MAX_DEV_REQ_UPSIZE) {
+		gossip_err("orangefs: client-core tried to read wrong size\n");
+		return -EINVAL;
+	}
+
+	/* Check for an empty list before locking. */
+	if (list_empty(&orangefs_request_list))
+		return -EAGAIN;
+
+restart:
+	cur_op = NULL;
+	/* Get next op (if any) from top of list. */
+	spin_lock(&orangefs_request_list_lock);
+	list_for_each_entry_safe(op, temp, &orangefs_request_list, list) {
+		__s32 fsid;
+		/* This lock is held past the end of the loop when we break. */
+		spin_lock(&op->lock);
+		if (unlikely(op_state_purged(op) || op_state_given_up(op))) {
+			spin_unlock(&op->lock);
+			continue;
+		}
+
+		fsid = fsid_of_op(op);
+		if (fsid != ORANGEFS_FS_ID_NULL) {
+			int ret;
+			/* Skip ops whose filesystem needs to be mounted. */
+			ret = fs_mount_pending(fsid);
+			if (ret == 1) {
+				gossip_debug(GOSSIP_DEV_DEBUG,
+				    "%s: mount pending, skipping op tag "
+				    "%llu %s\n",
+				    __func__,
+				    llu(op->tag),
+				    get_opname_string(op));
+				spin_unlock(&op->lock);
+				continue;
+			/*
+			 * Skip ops whose filesystem we don't know about unless
+			 * it is being mounted or unmounted.  It is possible for
+			 * a filesystem we don't know about to be unmounted if
+			 * it fails to mount in the kernel after userspace has
+			 * been sent the mount request.
+			 */
+			/* XXX: is there a better way to detect this? */
+			} else if (ret == -1 &&
+				   !(op->upcall.type ==
+					ORANGEFS_VFS_OP_FS_MOUNT ||
+				     op->upcall.type ==
+					ORANGEFS_VFS_OP_GETATTR ||
+				     op->upcall.type ==
+					ORANGEFS_VFS_OP_FS_UMOUNT)) {
+				gossip_debug(GOSSIP_DEV_DEBUG,
+				    "orangefs: skipping op tag %llu %s\n",
+				    llu(op->tag), get_opname_string(op));
+				gossip_err(
+				    "orangefs: ERROR: fs_mount_pending %d\n",
+				    fsid);
+				spin_unlock(&op->lock);
+				continue;
+			}
+		}
+		/*
+		 * Either this op does not pertain to a filesystem, is mounting
+		 * a filesystem, or pertains to a mounted filesystem. Let it
+		 * through.
+		 */
+		cur_op = op;
+		break;
+	}
+
+	/*
+	 * At this point we either have a valid op and can continue or have not
+	 * found an op and must ask the client to try again later.
+	 */
+	if (!cur_op) {
+		spin_unlock(&orangefs_request_list_lock);
+		return -EAGAIN;
+	}
+
+	gossip_debug(GOSSIP_DEV_DEBUG, "%s: reading op tag %llu %s\n",
+		     __func__,
+		     llu(cur_op->tag),
+		     get_opname_string(cur_op));
+
+	/*
+	 * Such an op should never be on the list in the first place. If so, we
+	 * will abort.
+	 */
+	if (op_state_in_progress(cur_op) || op_state_serviced(cur_op)) {
+		gossip_err("orangefs: ERROR: Current op already queued.\n");
+		list_del_init(&cur_op->list);
+		spin_unlock(&cur_op->lock);
+		spin_unlock(&orangefs_request_list_lock);
+		return -EAGAIN;
+	}
+
+	list_del_init(&cur_op->list);
+	spin_unlock(&orangefs_request_list_lock);
+
+	spin_unlock(&cur_op->lock);
+
+	/* Push the upcall out. */
+	ret = copy_to_user(buf, &proto_ver, sizeof(__s32));
+	if (ret != 0)
+		goto error;
+	ret = copy_to_user(buf + sizeof(__s32), &magic, sizeof(__s32));
+	if (ret != 0)
+		goto error;
+	ret = copy_to_user(buf + 2 * sizeof(__s32),
+		&cur_op->tag,
+		sizeof(__u64));
+	if (ret != 0)
+		goto error;
+	ret = copy_to_user(buf + 2 * sizeof(__s32) + sizeof(__u64),
+		&cur_op->upcall,
+		sizeof(struct orangefs_upcall_s));
+	if (ret != 0)
+		goto error;
+
+	spin_lock(&orangefs_htable_ops_in_progress_lock);
+	spin_lock(&cur_op->lock);
+	if (unlikely(op_state_given_up(cur_op))) {
+		spin_unlock(&cur_op->lock);
+		spin_unlock(&orangefs_htable_ops_in_progress_lock);
+		complete(&cur_op->waitq);
+		goto restart;
+	}
+
+	/*
+	 * Set the operation to be in progress and move it between lists since
+	 * it has been sent to the client.
+	 */
+	set_op_state_inprogress(cur_op);
+	gossip_debug(GOSSIP_DEV_DEBUG,
+		     "%s: 1 op:%s: op_state:%d: process:%s:\n",
+		     __func__,
+		     get_opname_string(cur_op),
+		     cur_op->op_state,
+		     current->comm);
+	orangefs_devreq_add_op(cur_op);
+	spin_unlock(&cur_op->lock);
+	spin_unlock(&orangefs_htable_ops_in_progress_lock);
+
+	/* The client only asks to read one size buffer. */
+	return MAX_DEV_REQ_UPSIZE;
+error:
+	/*
+	 * We were unable to copy the op data to the client. Put the op back in
+	 * list. If client has crashed, the op will be purged later when the
+	 * device is released.
+	 */
+	gossip_err("orangefs: Failed to copy data to user space\n");
+	spin_lock(&orangefs_request_list_lock);
+	spin_lock(&cur_op->lock);
+	if (likely(!op_state_given_up(cur_op))) {
+		set_op_state_waiting(cur_op);
+		gossip_debug(GOSSIP_DEV_DEBUG,
+			     "%s: 2 op:%s: op_state:%d: process:%s:\n",
+			     __func__,
+			     get_opname_string(cur_op),
+			     cur_op->op_state,
+			     current->comm);
+		list_add(&cur_op->list, &orangefs_request_list);
+		spin_unlock(&cur_op->lock);
+	} else {
+		spin_unlock(&cur_op->lock);
+		complete(&cur_op->waitq);
+	}
+	spin_unlock(&orangefs_request_list_lock);
+	return -EFAULT;
+}
+
+/*
+ * Function for writev() callers into the device.
+ *
+ * Userspace should have written:
+ *  - __u32 version
+ *  - __u32 magic
+ *  - __u64 tag
+ *  - struct orangefs_downcall_s
+ *  - trailer buffer (in the case of READDIR operations)
+ */
+static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb,
+				      struct iov_iter *iter)
+{
+	ssize_t ret;
+	struct orangefs_kernel_op_s *op = NULL;
+	struct {
+		__u32 version;
+		__u32 magic;
+		__u64 tag;
+	} head;
+	int total = ret = iov_iter_count(iter);
+	int downcall_size = sizeof(struct orangefs_downcall_s);
+	int head_size = sizeof(head);
+
+	gossip_debug(GOSSIP_DEV_DEBUG, "%s: total:%d: ret:%zd:\n",
+		     __func__,
+		     total,
+		     ret);
+
+        if (total < MAX_DEV_REQ_DOWNSIZE) {
+		gossip_err("%s: total:%d: must be at least:%u:\n",
+			   __func__,
+			   total,
+			   (unsigned int) MAX_DEV_REQ_DOWNSIZE);
+		return -EFAULT;
+	}
+
+	if (!copy_from_iter_full(&head, head_size, iter)) {
+		gossip_err("%s: failed to copy head.\n", __func__);
+		return -EFAULT;
+	}
+
+	if (head.version < ORANGEFS_MINIMUM_USERSPACE_VERSION) {
+		gossip_err("%s: userspace claims version"
+			   "%d, minimum version required: %d.\n",
+			   __func__,
+			   head.version,
+			   ORANGEFS_MINIMUM_USERSPACE_VERSION);
+		return -EPROTO;
+	}
+
+	if (head.magic != ORANGEFS_DEVREQ_MAGIC) {
+		gossip_err("Error: Device magic number does not match.\n");
+		return -EPROTO;
+	}
+
+	if (!orangefs_userspace_version) {
+		orangefs_userspace_version = head.version;
+	} else if (orangefs_userspace_version != head.version) {
+		gossip_err("Error: userspace version changes\n");
+		return -EPROTO;
+	}
+
+	/* remove the op from the in progress hash table */
+	op = orangefs_devreq_remove_op(head.tag);
+	if (!op) {
+		gossip_debug(GOSSIP_DEV_DEBUG,
+			     "%s: No one's waiting for tag %llu\n",
+			     __func__, llu(head.tag));
+		return ret;
+	}
+
+	if (!copy_from_iter_full(&op->downcall, downcall_size, iter)) {
+		gossip_err("%s: failed to copy downcall.\n", __func__);
+		goto Efault;
+	}
+
+	if (op->downcall.status)
+		goto wakeup;
+
+	/*
+	 * We've successfully peeled off the head and the downcall.
+	 * Something has gone awry if total doesn't equal the
+	 * sum of head_size, downcall_size and trailer_size.
+	 */
+	if ((head_size + downcall_size + op->downcall.trailer_size) != total) {
+		gossip_err("%s: funky write, head_size:%d"
+			   ": downcall_size:%d: trailer_size:%lld"
+			   ": total size:%d:\n",
+			   __func__,
+			   head_size,
+			   downcall_size,
+			   op->downcall.trailer_size,
+			   total);
+		goto Efault;
+	}
+
+	/* Only READDIR operations should have trailers. */
+	if ((op->downcall.type != ORANGEFS_VFS_OP_READDIR) &&
+	    (op->downcall.trailer_size != 0)) {
+		gossip_err("%s: %x operation with trailer.",
+			   __func__,
+			   op->downcall.type);
+		goto Efault;
+	}
+
+	/* READDIR operations should always have trailers. */
+	if ((op->downcall.type == ORANGEFS_VFS_OP_READDIR) &&
+	    (op->downcall.trailer_size == 0)) {
+		gossip_err("%s: %x operation with no trailer.",
+			   __func__,
+			   op->downcall.type);
+		goto Efault;
+	}
+
+	if (op->downcall.type != ORANGEFS_VFS_OP_READDIR)
+		goto wakeup;
+
+	op->downcall.trailer_buf = vzalloc(op->downcall.trailer_size);
+	if (!op->downcall.trailer_buf)
+		goto Enomem;
+
+	if (!copy_from_iter_full(op->downcall.trailer_buf,
+			         op->downcall.trailer_size, iter)) {
+		gossip_err("%s: failed to copy trailer.\n", __func__);
+		vfree(op->downcall.trailer_buf);
+		goto Efault;
+	}
+
+wakeup:
+	/*
+	 * Return to vfs waitqueue, and back to service_operation
+	 * through wait_for_matching_downcall.
+	 */
+	spin_lock(&op->lock);
+	if (unlikely(op_is_cancel(op))) {
+		spin_unlock(&op->lock);
+		put_cancel(op);
+	} else if (unlikely(op_state_given_up(op))) {
+		spin_unlock(&op->lock);
+		complete(&op->waitq);
+	} else {
+		set_op_state_serviced(op);
+		gossip_debug(GOSSIP_DEV_DEBUG,
+			     "%s: op:%s: op_state:%d: process:%s:\n",
+			     __func__,
+			     get_opname_string(op),
+			     op->op_state,
+			     current->comm);
+		spin_unlock(&op->lock);
+	}
+	return ret;
+
+Efault:
+	op->downcall.status = -(ORANGEFS_ERROR_BIT | 9);
+	ret = -EFAULT;
+	goto wakeup;
+
+Enomem:
+	op->downcall.status = -(ORANGEFS_ERROR_BIT | 8);
+	ret = -ENOMEM;
+	goto wakeup;
+}
+
+/*
+ * NOTE: gets called when the last reference to this device is dropped.
+ * Using the open_access_count variable, we enforce a reference count
+ * on this file so that it can be opened by only one process at a time.
+ * the devreq_mutex is used to make sure all i/o has completed
+ * before we call orangefs_bufmap_finalize, and similar such tricky
+ * situations
+ */
+static int orangefs_devreq_release(struct inode *inode, struct file *file)
+{
+	int unmounted = 0;
+
+	gossip_debug(GOSSIP_DEV_DEBUG,
+		     "%s:pvfs2-client-core: exiting, closing device\n",
+		     __func__);
+
+	mutex_lock(&devreq_mutex);
+	orangefs_bufmap_finalize();
+
+	open_access_count = -1;
+
+	unmounted = mark_all_pending_mounts();
+	gossip_debug(GOSSIP_DEV_DEBUG, "ORANGEFS Device Close: Filesystem(s) %s\n",
+		     (unmounted ? "UNMOUNTED" : "MOUNTED"));
+
+	purge_waiting_ops();
+	purge_inprogress_ops();
+
+	orangefs_bufmap_run_down();
+
+	gossip_debug(GOSSIP_DEV_DEBUG,
+		     "pvfs2-client-core: device close complete\n");
+	open_access_count = 0;
+	orangefs_userspace_version = 0;
+	mutex_unlock(&devreq_mutex);
+	return 0;
+}
+
+int is_daemon_in_service(void)
+{
+	int in_service;
+
+	/*
+	 * What this function does is checks if client-core is alive
+	 * based on the access count we maintain on the device.
+	 */
+	mutex_lock(&devreq_mutex);
+	in_service = open_access_count == 1 ? 0 : -EIO;
+	mutex_unlock(&devreq_mutex);
+	return in_service;
+}
+
+bool __is_daemon_in_service(void)
+{
+	return open_access_count == 1;
+}
+
+static inline long check_ioctl_command(unsigned int command)
+{
+	/* Check for valid ioctl codes */
+	if (_IOC_TYPE(command) != ORANGEFS_DEV_MAGIC) {
+		gossip_err("device ioctl magic numbers don't match! Did you rebuild pvfs2-client-core/libpvfs2? [cmd %x, magic %x != %x]\n",
+			command,
+			_IOC_TYPE(command),
+			ORANGEFS_DEV_MAGIC);
+		return -EINVAL;
+	}
+	/* and valid ioctl commands */
+	if (_IOC_NR(command) >= ORANGEFS_DEV_MAXNR || _IOC_NR(command) <= 0) {
+		gossip_err("Invalid ioctl command number [%d >= %d]\n",
+			   _IOC_NR(command), ORANGEFS_DEV_MAXNR);
+		return -ENOIOCTLCMD;
+	}
+	return 0;
+}
+
+static long dispatch_ioctl_command(unsigned int command, unsigned long arg)
+{
+	static __s32 magic = ORANGEFS_DEVREQ_MAGIC;
+	static __s32 max_up_size = MAX_DEV_REQ_UPSIZE;
+	static __s32 max_down_size = MAX_DEV_REQ_DOWNSIZE;
+	struct ORANGEFS_dev_map_desc user_desc;
+	int ret = 0;
+	int upstream_kmod = 1;
+	struct orangefs_sb_info_s *orangefs_sb;
+
+	/* mtmoore: add locking here */
+
+	switch (command) {
+	case ORANGEFS_DEV_GET_MAGIC:
+		return ((put_user(magic, (__s32 __user *) arg) == -EFAULT) ?
+			-EIO :
+			0);
+	case ORANGEFS_DEV_GET_MAX_UPSIZE:
+		return ((put_user(max_up_size,
+				  (__s32 __user *) arg) == -EFAULT) ?
+					-EIO :
+					0);
+	case ORANGEFS_DEV_GET_MAX_DOWNSIZE:
+		return ((put_user(max_down_size,
+				  (__s32 __user *) arg) == -EFAULT) ?
+					-EIO :
+					0);
+	case ORANGEFS_DEV_MAP:
+		ret = copy_from_user(&user_desc,
+				     (struct ORANGEFS_dev_map_desc __user *)
+				     arg,
+				     sizeof(struct ORANGEFS_dev_map_desc));
+		/* WTF -EIO and not -EFAULT? */
+		return ret ? -EIO : orangefs_bufmap_initialize(&user_desc);
+	case ORANGEFS_DEV_REMOUNT_ALL:
+		gossip_debug(GOSSIP_DEV_DEBUG,
+			     "%s: got ORANGEFS_DEV_REMOUNT_ALL\n",
+			     __func__);
+
+		/*
+		 * remount all mounted orangefs volumes to regain the lost
+		 * dynamic mount tables (if any) -- NOTE: this is done
+		 * without keeping the superblock list locked due to the
+		 * upcall/downcall waiting.  also, the request mutex is
+		 * used to ensure that no operations will be serviced until
+		 * all of the remounts are serviced (to avoid ops between
+		 * mounts to fail)
+		 */
+		ret = mutex_lock_interruptible(&orangefs_request_mutex);
+		if (ret < 0)
+			return ret;
+		gossip_debug(GOSSIP_DEV_DEBUG,
+			     "%s: priority remount in progress\n",
+			     __func__);
+		spin_lock(&orangefs_superblocks_lock);
+		list_for_each_entry(orangefs_sb, &orangefs_superblocks, list) {
+			/*
+			 * We have to drop the spinlock, so entries can be
+			 * removed.  They can't be freed, though, so we just
+			 * keep the forward pointers and zero the back ones -
+			 * that way we can get to the rest of the list.
+			 */
+			if (!orangefs_sb->list.prev)
+				continue;
+			gossip_debug(GOSSIP_DEV_DEBUG,
+				     "%s: Remounting SB %p\n",
+				     __func__,
+				     orangefs_sb);
+
+			spin_unlock(&orangefs_superblocks_lock);
+			ret = orangefs_remount(orangefs_sb);
+			spin_lock(&orangefs_superblocks_lock);
+			if (ret) {
+				gossip_debug(GOSSIP_DEV_DEBUG,
+					     "SB %p remount failed\n",
+					     orangefs_sb);
+				break;
+			}
+		}
+		spin_unlock(&orangefs_superblocks_lock);
+		gossip_debug(GOSSIP_DEV_DEBUG,
+			     "%s: priority remount complete\n",
+			     __func__);
+		mutex_unlock(&orangefs_request_mutex);
+		return ret;
+
+	case ORANGEFS_DEV_UPSTREAM:
+		ret = copy_to_user((void __user *)arg,
+				    &upstream_kmod,
+				    sizeof(upstream_kmod));
+
+		if (ret != 0)
+			return -EIO;
+		else
+			return ret;
+
+	case ORANGEFS_DEV_CLIENT_MASK:
+		return orangefs_debugfs_new_client_mask((void __user *)arg);
+	case ORANGEFS_DEV_CLIENT_STRING:
+		return orangefs_debugfs_new_client_string((void __user *)arg);
+	case ORANGEFS_DEV_DEBUG:
+		return orangefs_debugfs_new_debug((void __user *)arg);
+	default:
+		return -ENOIOCTLCMD;
+	}
+	return -ENOIOCTLCMD;
+}
+
+static long orangefs_devreq_ioctl(struct file *file,
+			       unsigned int command, unsigned long arg)
+{
+	long ret;
+
+	/* Check for properly constructed commands */
+	ret = check_ioctl_command(command);
+	if (ret < 0)
+		return (int)ret;
+
+	return (int)dispatch_ioctl_command(command, arg);
+}
+
+#ifdef CONFIG_COMPAT		/* CONFIG_COMPAT is in .config */
+
+/*  Compat structure for the ORANGEFS_DEV_MAP ioctl */
+struct ORANGEFS_dev_map_desc32 {
+	compat_uptr_t ptr;
+	__s32 total_size;
+	__s32 size;
+	__s32 count;
+};
+
+/*
+ * 32 bit user-space apps' ioctl handlers when kernel modules
+ * is compiled as a 64 bit one
+ */
+static long orangefs_devreq_compat_ioctl(struct file *filp, unsigned int cmd,
+				      unsigned long args)
+{
+	long ret;
+
+	/* Check for properly constructed commands */
+	ret = check_ioctl_command(cmd);
+	if (ret < 0)
+		return ret;
+	if (cmd == ORANGEFS_DEV_MAP) {
+		struct ORANGEFS_dev_map_desc desc;
+		struct ORANGEFS_dev_map_desc32 d32;
+
+		if (copy_from_user(&d32, (void __user *)args, sizeof(d32)))
+			return -EFAULT;
+
+		desc.ptr = compat_ptr(d32.ptr);
+		desc.total_size = d32.total_size;
+		desc.size = d32.size;
+		desc.count = d32.count;
+		return orangefs_bufmap_initialize(&desc);
+	}
+	/* no other ioctl requires translation */
+	return dispatch_ioctl_command(cmd, args);
+}
+
+#endif /* CONFIG_COMPAT is in .config */
+
+static __poll_t orangefs_devreq_poll(struct file *file,
+				      struct poll_table_struct *poll_table)
+{
+	__poll_t poll_revent_mask = 0;
+
+	poll_wait(file, &orangefs_request_list_waitq, poll_table);
+
+	if (!list_empty(&orangefs_request_list))
+		poll_revent_mask |= EPOLLIN;
+	return poll_revent_mask;
+}
+
+/* the assigned character device major number */
+static int orangefs_dev_major;
+
+static const struct file_operations orangefs_devreq_file_operations = {
+	.owner = THIS_MODULE,
+	.read = orangefs_devreq_read,
+	.write_iter = orangefs_devreq_write_iter,
+	.open = orangefs_devreq_open,
+	.release = orangefs_devreq_release,
+	.unlocked_ioctl = orangefs_devreq_ioctl,
+
+#ifdef CONFIG_COMPAT		/* CONFIG_COMPAT is in .config */
+	.compat_ioctl = orangefs_devreq_compat_ioctl,
+#endif
+	.poll = orangefs_devreq_poll
+};
+
+/*
+ * Initialize orangefs device specific state:
+ * Must be called at module load time only
+ */
+int orangefs_dev_init(void)
+{
+	/* register orangefs-req device  */
+	orangefs_dev_major = register_chrdev(0,
+					  ORANGEFS_REQDEVICE_NAME,
+					  &orangefs_devreq_file_operations);
+	if (orangefs_dev_major < 0) {
+		gossip_debug(GOSSIP_DEV_DEBUG,
+			     "Failed to register /dev/%s (error %d)\n",
+			     ORANGEFS_REQDEVICE_NAME, orangefs_dev_major);
+		return orangefs_dev_major;
+	}
+
+	gossip_debug(GOSSIP_DEV_DEBUG,
+		     "*** /dev/%s character device registered ***\n",
+		     ORANGEFS_REQDEVICE_NAME);
+	gossip_debug(GOSSIP_DEV_DEBUG, "'mknod /dev/%s c %d 0'.\n",
+		     ORANGEFS_REQDEVICE_NAME, orangefs_dev_major);
+	return 0;
+}
+
+void orangefs_dev_cleanup(void)
+{
+	unregister_chrdev(orangefs_dev_major, ORANGEFS_REQDEVICE_NAME);
+	gossip_debug(GOSSIP_DEV_DEBUG,
+		     "*** /dev/%s character device unregistered ***\n",
+		     ORANGEFS_REQDEVICE_NAME);
+}