initial_commit

1 files changed, 948 insertions, 0 deletions

diff --git a/fs/read_write.c b/fs/read_write.c
new file mode 100644
index 00000000..5520f8ad
--- /dev/null
+++ b/fs/read_write.c
@@ -0,0 +1,948 @@
+/*
+ *  linux/fs/read_write.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+#include <linux/slab.h> 
+#include <linux/stat.h>
+#include <linux/fcntl.h>
+#include <linux/file.h>
+#include <linux/uio.h>
+#include <linux/fsnotify.h>
+#include <linux/security.h>
+#include <linux/module.h>
+#include <linux/syscalls.h>
+#include <linux/pagemap.h>
+#include <linux/splice.h>
+#include "read_write.h"
+
+#include <asm/uaccess.h>
+#include <asm/unistd.h>
+
+const struct file_operations generic_ro_fops = {
+	.llseek		= generic_file_llseek,
+	.read		= do_sync_read,
+	.aio_read	= generic_file_aio_read,
+	.mmap		= generic_file_readonly_mmap,
+	.splice_read	= generic_file_splice_read,
+};
+
+EXPORT_SYMBOL(generic_ro_fops);
+
+static inline int unsigned_offsets(struct file *file)
+{
+	return file->f_mode & FMODE_UNSIGNED_OFFSET;
+}
+
+/**
+ * generic_file_llseek_unlocked - lockless generic llseek implementation
+ * @file:	file structure to seek on
+ * @offset:	file offset to seek to
+ * @origin:	type of seek
+ *
+ * Updates the file offset to the value specified by @offset and @origin.
+ * Locking must be provided by the caller.
+ */
+loff_t
+generic_file_llseek_unlocked(struct file *file, loff_t offset, int origin)
+{
+	struct inode *inode = file->f_mapping->host;
+
+	switch (origin) {
+	case SEEK_END:
+		offset += inode->i_size;
+		break;
+	case SEEK_CUR:
+		/*
+		 * Here we special-case the lseek(fd, 0, SEEK_CUR)
+		 * position-querying operation.  Avoid rewriting the "same"
+		 * f_pos value back to the file because a concurrent read(),
+		 * write() or lseek() might have altered it
+		 */
+		if (offset == 0)
+			return file->f_pos;
+		offset += file->f_pos;
+		break;
+	}
+
+	if (offset < 0 && !unsigned_offsets(file))
+		return -EINVAL;
+	if (offset > inode->i_sb->s_maxbytes)
+		return -EINVAL;
+
+	/* Special lock needed here? */
+	if (offset != file->f_pos) {
+		file->f_pos = offset;
+		file->f_version = 0;
+	}
+
+	return offset;
+}
+EXPORT_SYMBOL(generic_file_llseek_unlocked);
+
+/**
+ * generic_file_llseek - generic llseek implementation for regular files
+ * @file:	file structure to seek on
+ * @offset:	file offset to seek to
+ * @origin:	type of seek
+ *
+ * This is a generic implemenation of ->llseek useable for all normal local
+ * filesystems.  It just updates the file offset to the value specified by
+ * @offset and @origin under i_mutex.
+ */
+loff_t generic_file_llseek(struct file *file, loff_t offset, int origin)
+{
+	loff_t rval;
+
+	mutex_lock(&file->f_dentry->d_inode->i_mutex);
+	rval = generic_file_llseek_unlocked(file, offset, origin);
+	mutex_unlock(&file->f_dentry->d_inode->i_mutex);
+
+	return rval;
+}
+EXPORT_SYMBOL(generic_file_llseek);
+
+/**
+ * noop_llseek - No Operation Performed llseek implementation
+ * @file:	file structure to seek on
+ * @offset:	file offset to seek to
+ * @origin:	type of seek
+ *
+ * This is an implementation of ->llseek useable for the rare special case when
+ * userspace expects the seek to succeed but the (device) file is actually not
+ * able to perform the seek. In this case you use noop_llseek() instead of
+ * falling back to the default implementation of ->llseek.
+ */
+loff_t noop_llseek(struct file *file, loff_t offset, int origin)
+{
+	return file->f_pos;
+}
+EXPORT_SYMBOL(noop_llseek);
+
+loff_t no_llseek(struct file *file, loff_t offset, int origin)
+{
+	return -ESPIPE;
+}
+EXPORT_SYMBOL(no_llseek);
+
+loff_t default_llseek(struct file *file, loff_t offset, int origin)
+{
+	loff_t retval;
+
+	mutex_lock(&file->f_dentry->d_inode->i_mutex);
+	switch (origin) {
+		case SEEK_END:
+			offset += i_size_read(file->f_path.dentry->d_inode);
+			break;
+		case SEEK_CUR:
+			if (offset == 0) {
+				retval = file->f_pos;
+				goto out;
+			}
+			offset += file->f_pos;
+	}
+	retval = -EINVAL;
+	if (offset >= 0 || unsigned_offsets(file)) {
+		if (offset != file->f_pos) {
+			file->f_pos = offset;
+			file->f_version = 0;
+		}
+		retval = offset;
+	}
+out:
+	mutex_unlock(&file->f_dentry->d_inode->i_mutex);
+	return retval;
+}
+EXPORT_SYMBOL(default_llseek);
+
+loff_t vfs_llseek(struct file *file, loff_t offset, int origin)
+{
+	loff_t (*fn)(struct file *, loff_t, int);
+
+	fn = no_llseek;
+	if (file->f_mode & FMODE_LSEEK) {
+		if (file->f_op && file->f_op->llseek)
+			fn = file->f_op->llseek;
+	}
+	return fn(file, offset, origin);
+}
+EXPORT_SYMBOL(vfs_llseek);
+
+SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, origin)
+{
+	off_t retval;
+	struct file * file;
+	int fput_needed;
+
+	retval = -EBADF;
+	file = fget_light(fd, &fput_needed);
+	if (!file)
+		goto bad;
+
+	retval = -EINVAL;
+	if (origin <= SEEK_MAX) {
+		loff_t res = vfs_llseek(file, offset, origin);
+		retval = res;
+		if (res != (loff_t)retval)
+			retval = -EOVERFLOW;	/* LFS: should only happen on 32 bit platforms */
+	}
+	fput_light(file, fput_needed);
+bad:
+	return retval;
+}
+
+#ifdef __ARCH_WANT_SYS_LLSEEK
+SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high,
+		unsigned long, offset_low, loff_t __user *, result,
+		unsigned int, origin)
+{
+	int retval;
+	struct file * file;
+	loff_t offset;
+	int fput_needed;
+
+	retval = -EBADF;
+	file = fget_light(fd, &fput_needed);
+	if (!file)
+		goto bad;
+
+	retval = -EINVAL;
+	if (origin > SEEK_MAX)
+		goto out_putf;
+
+	offset = vfs_llseek(file, ((loff_t) offset_high << 32) | offset_low,
+			origin);
+
+	retval = (int)offset;
+	if (offset >= 0) {
+		retval = -EFAULT;
+		if (!copy_to_user(result, &offset, sizeof(offset)))
+			retval = 0;
+	}
+out_putf:
+	fput_light(file, fput_needed);
+bad:
+	return retval;
+}
+#endif
+
+
+/*
+ * rw_verify_area doesn't like huge counts. We limit
+ * them to something that fits in "int" so that others
+ * won't have to do range checks all the time.
+ */
+int rw_verify_area(int read_write, struct file *file, loff_t *ppos, size_t count)
+{
+	struct inode *inode;
+	loff_t pos;
+	int retval = -EINVAL;
+
+	inode = file->f_path.dentry->d_inode;
+	if (unlikely((ssize_t) count < 0))
+		return retval;
+	pos = *ppos;
+	if (unlikely(pos < 0)) {
+		if (!unsigned_offsets(file))
+			return retval;
+		if (count >= -pos) /* both values are in 0..LLONG_MAX */
+			return -EOVERFLOW;
+	} else if (unlikely((loff_t) (pos + count) < 0)) {
+		if (!unsigned_offsets(file))
+			return retval;
+	}
+
+	if (unlikely(inode->i_flock && mandatory_lock(inode))) {
+		retval = locks_mandatory_area(
+			read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE,
+			inode, file, pos, count);
+		if (retval < 0)
+			return retval;
+	}
+	retval = security_file_permission(file,
+				read_write == READ ? MAY_READ : MAY_WRITE);
+	if (retval)
+		return retval;
+	return count > MAX_RW_COUNT ? MAX_RW_COUNT : count;
+}
+
+static void wait_on_retry_sync_kiocb(struct kiocb *iocb)
+{
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	if (!kiocbIsKicked(iocb))
+		schedule();
+	else
+		kiocbClearKicked(iocb);
+	__set_current_state(TASK_RUNNING);
+}
+
+ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
+{
+	struct iovec iov = { .iov_base = buf, .iov_len = len };
+	struct kiocb kiocb;
+	ssize_t ret;
+
+	init_sync_kiocb(&kiocb, filp);
+	kiocb.ki_pos = *ppos;
+	kiocb.ki_left = len;
+	kiocb.ki_nbytes = len;
+
+	for (;;) {
+		ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos);
+		if (ret != -EIOCBRETRY)
+			break;
+		wait_on_retry_sync_kiocb(&kiocb);
+	}
+
+	if (-EIOCBQUEUED == ret)
+		ret = wait_on_sync_kiocb(&kiocb);
+	*ppos = kiocb.ki_pos;
+	return ret;
+}
+
+EXPORT_SYMBOL(do_sync_read);
+
+ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
+{
+	ssize_t ret;
+
+	if (!(file->f_mode & FMODE_READ))
+		return -EBADF;
+	if (!file->f_op || (!file->f_op->read && !file->f_op->aio_read))
+		return -EINVAL;
+	if (unlikely(!access_ok(VERIFY_WRITE, buf, count)))
+		return -EFAULT;
+
+	ret = rw_verify_area(READ, file, pos, count);
+	if (ret >= 0) {
+		count = ret;
+		if (file->f_op->read)
+			ret = file->f_op->read(file, buf, count, pos);
+		else
+			ret = do_sync_read(file, buf, count, pos);
+		if (ret > 0) {
+			fsnotify_access(file);
+			add_rchar(current, ret);
+		}
+		inc_syscr(current);
+	}
+
+	return ret;
+}
+
+EXPORT_SYMBOL(vfs_read);
+
+ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
+{
+	struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
+	struct kiocb kiocb;
+	ssize_t ret;
+
+	init_sync_kiocb(&kiocb, filp);
+	kiocb.ki_pos = *ppos;
+	kiocb.ki_left = len;
+	kiocb.ki_nbytes = len;
+
+	for (;;) {
+		ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos);
+		if (ret != -EIOCBRETRY)
+			break;
+		wait_on_retry_sync_kiocb(&kiocb);
+	}
+
+	if (-EIOCBQUEUED == ret)
+		ret = wait_on_sync_kiocb(&kiocb);
+	*ppos = kiocb.ki_pos;
+	return ret;
+}
+
+EXPORT_SYMBOL(do_sync_write);
+
+ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
+{
+	ssize_t ret;
+
+	if (!(file->f_mode & FMODE_WRITE))
+		return -EBADF;
+	if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write))
+		return -EINVAL;
+	if (unlikely(!access_ok(VERIFY_READ, buf, count)))
+		return -EFAULT;
+
+	ret = rw_verify_area(WRITE, file, pos, count);
+	if (ret >= 0) {
+		count = ret;
+		if (file->f_op->write)
+			ret = file->f_op->write(file, buf, count, pos);
+		else
+			ret = do_sync_write(file, buf, count, pos);
+		if (ret > 0) {
+			fsnotify_modify(file);
+			add_wchar(current, ret);
+		}
+		inc_syscw(current);
+	}
+
+	return ret;
+}
+
+EXPORT_SYMBOL(vfs_write);
+
+static inline loff_t file_pos_read(struct file *file)
+{
+	return file->f_pos;
+}
+
+static inline void file_pos_write(struct file *file, loff_t pos)
+{
+	file->f_pos = pos;
+}
+
+SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
+{
+	struct file *file;
+	ssize_t ret = -EBADF;
+	int fput_needed;
+
+	file = fget_light(fd, &fput_needed);
+	if (file) {
+		loff_t pos = file_pos_read(file);
+		ret = vfs_read(file, buf, count, &pos);
+		file_pos_write(file, pos);
+		fput_light(file, fput_needed);
+	}
+
+	return ret;
+}
+
+SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf,
+		size_t, count)
+{
+	struct file *file;
+	ssize_t ret = -EBADF;
+	int fput_needed;
+
+	file = fget_light(fd, &fput_needed);
+	if (file) {
+		loff_t pos = file_pos_read(file);
+		ret = vfs_write(file, buf, count, &pos);
+		file_pos_write(file, pos);
+		fput_light(file, fput_needed);
+	}
+
+	return ret;
+}
+
+SYSCALL_DEFINE(pread64)(unsigned int fd, char __user *buf,
+			size_t count, loff_t pos)
+{
+	struct file *file;
+	ssize_t ret = -EBADF;
+	int fput_needed;
+
+	if (pos < 0)
+		return -EINVAL;
+
+	file = fget_light(fd, &fput_needed);
+	if (file) {
+		ret = -ESPIPE;
+		if (file->f_mode & FMODE_PREAD)
+			ret = vfs_read(file, buf, count, &pos);
+		fput_light(file, fput_needed);
+	}
+
+	return ret;
+}
+#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
+asmlinkage long SyS_pread64(long fd, long buf, long count, loff_t pos)
+{
+	return SYSC_pread64((unsigned int) fd, (char __user *) buf,
+			    (size_t) count, pos);
+}
+SYSCALL_ALIAS(sys_pread64, SyS_pread64);
+#endif
+
+SYSCALL_DEFINE(pwrite64)(unsigned int fd, const char __user *buf,
+			 size_t count, loff_t pos)
+{
+	struct file *file;
+	ssize_t ret = -EBADF;
+	int fput_needed;
+
+	if (pos < 0)
+		return -EINVAL;
+
+	file = fget_light(fd, &fput_needed);
+	if (file) {
+		ret = -ESPIPE;
+		if (file->f_mode & FMODE_PWRITE)  
+			ret = vfs_write(file, buf, count, &pos);
+		fput_light(file, fput_needed);
+	}
+
+	return ret;
+}
+#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
+asmlinkage long SyS_pwrite64(long fd, long buf, long count, loff_t pos)
+{
+	return SYSC_pwrite64((unsigned int) fd, (const char __user *) buf,
+			     (size_t) count, pos);
+}
+SYSCALL_ALIAS(sys_pwrite64, SyS_pwrite64);
+#endif
+
+/*
+ * Reduce an iovec's length in-place.  Return the resulting number of segments
+ */
+unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to)
+{
+	unsigned long seg = 0;
+	size_t len = 0;
+
+	while (seg < nr_segs) {
+		seg++;
+		if (len + iov->iov_len >= to) {
+			iov->iov_len = to - len;
+			break;
+		}
+		len += iov->iov_len;
+		iov++;
+	}
+	return seg;
+}
+EXPORT_SYMBOL(iov_shorten);
+
+ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov,
+		unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn)
+{
+	struct kiocb kiocb;
+	ssize_t ret;
+
+	init_sync_kiocb(&kiocb, filp);
+	kiocb.ki_pos = *ppos;
+	kiocb.ki_left = len;
+	kiocb.ki_nbytes = len;
+
+	for (;;) {
+		ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos);
+		if (ret != -EIOCBRETRY)
+			break;
+		wait_on_retry_sync_kiocb(&kiocb);
+	}
+
+	if (ret == -EIOCBQUEUED)
+		ret = wait_on_sync_kiocb(&kiocb);
+	*ppos = kiocb.ki_pos;
+	return ret;
+}
+
+/* Do it by hand, with file-ops */
+ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov,
+		unsigned long nr_segs, loff_t *ppos, io_fn_t fn)
+{
+	struct iovec *vector = iov;
+	ssize_t ret = 0;
+
+	while (nr_segs > 0) {
+		void __user *base;
+		size_t len;
+		ssize_t nr;
+
+		base = vector->iov_base;
+		len = vector->iov_len;
+		vector++;
+		nr_segs--;
+
+		nr = fn(filp, base, len, ppos);
+
+		if (nr < 0) {
+			if (!ret)
+				ret = nr;
+			break;
+		}
+		ret += nr;
+		if (nr != len)
+			break;
+	}
+
+	return ret;
+}
+
+/* A write operation does a read from user space and vice versa */
+#define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ)
+
+ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
+			      unsigned long nr_segs, unsigned long fast_segs,
+			      struct iovec *fast_pointer,
+			      struct iovec **ret_pointer)
+{
+	unsigned long seg;
+	ssize_t ret;
+	struct iovec *iov = fast_pointer;
+
+	/*
+	 * SuS says "The readv() function *may* fail if the iovcnt argument
+	 * was less than or equal to 0, or greater than {IOV_MAX}.  Linux has
+	 * traditionally returned zero for zero segments, so...
+	 */
+	if (nr_segs == 0) {
+		ret = 0;
+		goto out;
+	}
+
+	/*
+	 * First get the "struct iovec" from user memory and
+	 * verify all the pointers
+	 */
+	if (nr_segs > UIO_MAXIOV) {
+		ret = -EINVAL;
+		goto out;
+	}
+	if (nr_segs > fast_segs) {
+		iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL);
+		if (iov == NULL) {
+			ret = -ENOMEM;
+			goto out;
+		}
+	}
+	if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	/*
+	 * According to the Single Unix Specification we should return EINVAL
+	 * if an element length is < 0 when cast to ssize_t or if the
+	 * total length would overflow the ssize_t return value of the
+	 * system call.
+	 *
+	 * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the
+	 * overflow case.
+	 */
+	ret = 0;
+	for (seg = 0; seg < nr_segs; seg++) {
+		void __user *buf = iov[seg].iov_base;
+		ssize_t len = (ssize_t)iov[seg].iov_len;
+
+		/* see if we we're about to use an invalid len or if
+		 * it's about to overflow ssize_t */
+		if (len < 0) {
+			ret = -EINVAL;
+			goto out;
+		}
+		if (unlikely(!access_ok(vrfy_dir(type), buf, len))) {
+			ret = -EFAULT;
+			goto out;
+		}
+		if (len > MAX_RW_COUNT - ret) {
+			len = MAX_RW_COUNT - ret;
+			iov[seg].iov_len = len;
+		}
+		ret += len;
+	}
+out:
+	*ret_pointer = iov;
+	return ret;
+}
+
+static ssize_t do_readv_writev(int type, struct file *file,
+			       const struct iovec __user * uvector,
+			       unsigned long nr_segs, loff_t *pos)
+{
+	size_t tot_len;
+	struct iovec iovstack[UIO_FASTIOV];
+	struct iovec *iov = iovstack;
+	ssize_t ret;
+	io_fn_t fn;
+	iov_fn_t fnv;
+
+	if (!file->f_op) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = rw_copy_check_uvector(type, uvector, nr_segs,
+			ARRAY_SIZE(iovstack), iovstack, &iov);
+	if (ret <= 0)
+		goto out;
+
+	tot_len = ret;
+	ret = rw_verify_area(type, file, pos, tot_len);
+	if (ret < 0)
+		goto out;
+
+	fnv = NULL;
+	if (type == READ) {
+		fn = file->f_op->read;
+		fnv = file->f_op->aio_read;
+	} else {
+		fn = (io_fn_t)file->f_op->write;
+		fnv = file->f_op->aio_write;
+	}
+
+	if (fnv)
+		ret = do_sync_readv_writev(file, iov, nr_segs, tot_len,
+						pos, fnv);
+	else
+		ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn);
+
+out:
+	if (iov != iovstack)
+		kfree(iov);
+	if ((ret + (type == READ)) > 0) {
+		if (type == READ)
+			fsnotify_access(file);
+		else
+			fsnotify_modify(file);
+	}
+	return ret;
+}
+
+ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
+		  unsigned long vlen, loff_t *pos)
+{
+	if (!(file->f_mode & FMODE_READ))
+		return -EBADF;
+	if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read))
+		return -EINVAL;
+
+	return do_readv_writev(READ, file, vec, vlen, pos);
+}
+
+EXPORT_SYMBOL(vfs_readv);
+
+ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
+		   unsigned long vlen, loff_t *pos)
+{
+	if (!(file->f_mode & FMODE_WRITE))
+		return -EBADF;
+	if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write))
+		return -EINVAL;
+
+	return do_readv_writev(WRITE, file, vec, vlen, pos);
+}
+
+EXPORT_SYMBOL(vfs_writev);
+
+SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
+		unsigned long, vlen)
+{
+	struct file *file;
+	ssize_t ret = -EBADF;
+	int fput_needed;
+
+	file = fget_light(fd, &fput_needed);
+	if (file) {
+		loff_t pos = file_pos_read(file);
+		ret = vfs_readv(file, vec, vlen, &pos);
+		file_pos_write(file, pos);
+		fput_light(file, fput_needed);
+	}
+
+	if (ret > 0)
+		add_rchar(current, ret);
+	inc_syscr(current);
+	return ret;
+}
+
+SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
+		unsigned long, vlen)
+{
+	struct file *file;
+	ssize_t ret = -EBADF;
+	int fput_needed;
+
+	file = fget_light(fd, &fput_needed);
+	if (file) {
+		loff_t pos = file_pos_read(file);
+		ret = vfs_writev(file, vec, vlen, &pos);
+		file_pos_write(file, pos);
+		fput_light(file, fput_needed);
+	}
+
+	if (ret > 0)
+		add_wchar(current, ret);
+	inc_syscw(current);
+	return ret;
+}
+
+static inline loff_t pos_from_hilo(unsigned long high, unsigned long low)
+{
+#define HALF_LONG_BITS (BITS_PER_LONG / 2)
+	return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low;
+}
+
+SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
+		unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
+{
+	loff_t pos = pos_from_hilo(pos_h, pos_l);
+	struct file *file;
+	ssize_t ret = -EBADF;
+	int fput_needed;
+
+	if (pos < 0)
+		return -EINVAL;
+
+	file = fget_light(fd, &fput_needed);
+	if (file) {
+		ret = -ESPIPE;
+		if (file->f_mode & FMODE_PREAD)
+			ret = vfs_readv(file, vec, vlen, &pos);
+		fput_light(file, fput_needed);
+	}
+
+	if (ret > 0)
+		add_rchar(current, ret);
+	inc_syscr(current);
+	return ret;
+}
+
+SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
+		unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
+{
+	loff_t pos = pos_from_hilo(pos_h, pos_l);
+	struct file *file;
+	ssize_t ret = -EBADF;
+	int fput_needed;
+
+	if (pos < 0)
+		return -EINVAL;
+
+	file = fget_light(fd, &fput_needed);
+	if (file) {
+		ret = -ESPIPE;
+		if (file->f_mode & FMODE_PWRITE)
+			ret = vfs_writev(file, vec, vlen, &pos);
+		fput_light(file, fput_needed);
+	}
+
+	if (ret > 0)
+		add_wchar(current, ret);
+	inc_syscw(current);
+	return ret;
+}
+
+static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
+			   size_t count, loff_t max)
+{
+	struct file * in_file, * out_file;
+	struct inode * in_inode, * out_inode;
+	loff_t pos;
+	ssize_t retval;
+	int fput_needed_in, fput_needed_out, fl;
+
+	/*
+	 * Get input file, and verify that it is ok..
+	 */
+	retval = -EBADF;
+	in_file = fget_light(in_fd, &fput_needed_in);
+	if (!in_file)
+		goto out;
+	if (!(in_file->f_mode & FMODE_READ))
+		goto fput_in;
+	retval = -ESPIPE;
+	if (!ppos)
+		ppos = &in_file->f_pos;
+	else
+		if (!(in_file->f_mode & FMODE_PREAD))
+			goto fput_in;
+	retval = rw_verify_area(READ, in_file, ppos, count);
+	if (retval < 0)
+		goto fput_in;
+	count = retval;
+
+	/*
+	 * Get output file, and verify that it is ok..
+	 */
+	retval = -EBADF;
+	out_file = fget_light(out_fd, &fput_needed_out);
+	if (!out_file)
+		goto fput_in;
+	if (!(out_file->f_mode & FMODE_WRITE))
+		goto fput_out;
+	retval = -EINVAL;
+	in_inode = in_file->f_path.dentry->d_inode;
+	out_inode = out_file->f_path.dentry->d_inode;
+	retval = rw_verify_area(WRITE, out_file, &out_file->f_pos, count);
+	if (retval < 0)
+		goto fput_out;
+	count = retval;
+
+	if (!max)
+		max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
+
+	pos = *ppos;
+	if (unlikely(pos + count > max)) {
+		retval = -EOVERFLOW;
+		if (pos >= max)
+			goto fput_out;
+		count = max - pos;
+	}
+
+	fl = 0;
+#if 0
+	/*
+	 * We need to debate whether we can enable this or not. The
+	 * man page documents EAGAIN return for the output at least,
+	 * and the application is arguably buggy if it doesn't expect
+	 * EAGAIN on a non-blocking file descriptor.
+	 */
+	if (in_file->f_flags & O_NONBLOCK)
+		fl = SPLICE_F_NONBLOCK;
+#endif
+	retval = do_splice_direct(in_file, ppos, out_file, count, fl);
+
+	if (retval > 0) {
+		add_rchar(current, retval);
+		add_wchar(current, retval);
+	}
+
+	inc_syscr(current);
+	inc_syscw(current);
+	if (*ppos > max)
+		retval = -EOVERFLOW;
+
+fput_out:
+	fput_light(out_file, fput_needed_out);
+fput_in:
+	fput_light(in_file, fput_needed_in);
+out:
+	return retval;
+}
+
+SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count)
+{
+	loff_t pos;
+	off_t off;
+	ssize_t ret;
+
+	if (offset) {
+		if (unlikely(get_user(off, offset)))
+			return -EFAULT;
+		pos = off;
+		ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
+		if (unlikely(put_user(pos, offset)))
+			return -EFAULT;
+		return ret;
+	}
+
+	return do_sendfile(out_fd, in_fd, NULL, count, 0);
+}
+
+SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count)
+{
+	loff_t pos;
+	ssize_t ret;
+
+	if (offset) {
+		if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
+			return -EFAULT;
+		ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
+		if (unlikely(put_user(pos, offset)))
+			return -EFAULT;
+		return ret;
+	}
+
+	return do_sendfile(out_fd, in_fd, NULL, count, 0);
+}