Initial import

1 files changed, 1353 insertions, 0 deletions

diff --git a/fs/read_write.c b/fs/read_write.c
new file mode 100644
index 000000000..8ace6ec15
--- /dev/null
+++ b/fs/read_write.c
@@ -0,0 +1,1353 @@
+/*
+ *  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/export.h>
+#include <linux/syscalls.h>
+#include <linux/pagemap.h>
+#include <linux/splice.h>
+#include <linux/compat.h>
+#include "internal.h"
+
+#include <asm/uaccess.h>
+#include <asm/unistd.h>
+
+typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *);
+typedef ssize_t (*iter_fn_t)(struct kiocb *, struct iov_iter *);
+
+const struct file_operations generic_ro_fops = {
+	.llseek		= generic_file_llseek,
+	.read_iter	= generic_file_read_iter,
+	.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;
+}
+
+/**
+ * vfs_setpos - update the file offset for lseek
+ * @file:	file structure in question
+ * @offset:	file offset to seek to
+ * @maxsize:	maximum file size
+ *
+ * This is a low-level filesystem helper for updating the file offset to
+ * the value specified by @offset if the given offset is valid and it is
+ * not equal to the current file offset.
+ *
+ * Return the specified offset on success and -EINVAL on invalid offset.
+ */
+loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize)
+{
+	if (offset < 0 && !unsigned_offsets(file))
+		return -EINVAL;
+	if (offset > maxsize)
+		return -EINVAL;
+
+	if (offset != file->f_pos) {
+		file->f_pos = offset;
+		file->f_version = 0;
+	}
+	return offset;
+}
+EXPORT_SYMBOL(vfs_setpos);
+
+/**
+ * generic_file_llseek_size - generic llseek implementation for regular files
+ * @file:	file structure to seek on
+ * @offset:	file offset to seek to
+ * @whence:	type of seek
+ * @size:	max size of this file in file system
+ * @eof:	offset used for SEEK_END position
+ *
+ * This is a variant of generic_file_llseek that allows passing in a custom
+ * maximum file size and a custom EOF position, for e.g. hashed directories
+ *
+ * Synchronization:
+ * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms)
+ * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes.
+ * read/writes behave like SEEK_SET against seeks.
+ */
+loff_t
+generic_file_llseek_size(struct file *file, loff_t offset, int whence,
+		loff_t maxsize, loff_t eof)
+{
+	switch (whence) {
+	case SEEK_END:
+		offset += eof;
+		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;
+		/*
+		 * f_lock protects against read/modify/write race with other
+		 * SEEK_CURs. Note that parallel writes and reads behave
+		 * like SEEK_SET.
+		 */
+		spin_lock(&file->f_lock);
+		offset = vfs_setpos(file, file->f_pos + offset, maxsize);
+		spin_unlock(&file->f_lock);
+		return offset;
+	case SEEK_DATA:
+		/*
+		 * In the generic case the entire file is data, so as long as
+		 * offset isn't at the end of the file then the offset is data.
+		 */
+		if (offset >= eof)
+			return -ENXIO;
+		break;
+	case SEEK_HOLE:
+		/*
+		 * There is a virtual hole at the end of the file, so as long as
+		 * offset isn't i_size or larger, return i_size.
+		 */
+		if (offset >= eof)
+			return -ENXIO;
+		offset = eof;
+		break;
+	}
+
+	return vfs_setpos(file, offset, maxsize);
+}
+EXPORT_SYMBOL(generic_file_llseek_size);
+
+/**
+ * generic_file_llseek - generic llseek implementation for regular files
+ * @file:	file structure to seek on
+ * @offset:	file offset to seek to
+ * @whence:	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 @whence.
+ */
+loff_t generic_file_llseek(struct file *file, loff_t offset, int whence)
+{
+	struct inode *inode = file->f_mapping->host;
+
+	return generic_file_llseek_size(file, offset, whence,
+					inode->i_sb->s_maxbytes,
+					i_size_read(inode));
+}
+EXPORT_SYMBOL(generic_file_llseek);
+
+/**
+ * fixed_size_llseek - llseek implementation for fixed-sized devices
+ * @file:	file structure to seek on
+ * @offset:	file offset to seek to
+ * @whence:	type of seek
+ * @size:	size of the file
+ *
+ */
+loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size)
+{
+	switch (whence) {
+	case SEEK_SET: case SEEK_CUR: case SEEK_END:
+		return generic_file_llseek_size(file, offset, whence,
+						size, size);
+	default:
+		return -EINVAL;
+	}
+}
+EXPORT_SYMBOL(fixed_size_llseek);
+
+/**
+ * noop_llseek - No Operation Performed llseek implementation
+ * @file:	file structure to seek on
+ * @offset:	file offset to seek to
+ * @whence:	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 whence)
+{
+	return file->f_pos;
+}
+EXPORT_SYMBOL(noop_llseek);
+
+loff_t no_llseek(struct file *file, loff_t offset, int whence)
+{
+	return -ESPIPE;
+}
+EXPORT_SYMBOL(no_llseek);
+
+loff_t default_llseek(struct file *file, loff_t offset, int whence)
+{
+	struct inode *inode = file_inode(file);
+	loff_t retval;
+
+	mutex_lock(&inode->i_mutex);
+	switch (whence) {
+		case SEEK_END:
+			offset += i_size_read(inode);
+			break;
+		case SEEK_CUR:
+			if (offset == 0) {
+				retval = file->f_pos;
+				goto out;
+			}
+			offset += file->f_pos;
+			break;
+		case SEEK_DATA:
+			/*
+			 * In the generic case the entire file is data, so as
+			 * long as offset isn't at the end of the file then the
+			 * offset is data.
+			 */
+			if (offset >= inode->i_size) {
+				retval = -ENXIO;
+				goto out;
+			}
+			break;
+		case SEEK_HOLE:
+			/*
+			 * There is a virtual hole at the end of the file, so
+			 * as long as offset isn't i_size or larger, return
+			 * i_size.
+			 */
+			if (offset >= inode->i_size) {
+				retval = -ENXIO;
+				goto out;
+			}
+			offset = inode->i_size;
+			break;
+	}
+	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(&inode->i_mutex);
+	return retval;
+}
+EXPORT_SYMBOL(default_llseek);
+
+loff_t vfs_llseek(struct file *file, loff_t offset, int whence)
+{
+	loff_t (*fn)(struct file *, loff_t, int);
+
+	fn = no_llseek;
+	if (file->f_mode & FMODE_LSEEK) {
+		if (file->f_op->llseek)
+			fn = file->f_op->llseek;
+	}
+	return fn(file, offset, whence);
+}
+EXPORT_SYMBOL(vfs_llseek);
+
+static inline struct fd fdget_pos(int fd)
+{
+	return __to_fd(__fdget_pos(fd));
+}
+
+static inline void fdput_pos(struct fd f)
+{
+	if (f.flags & FDPUT_POS_UNLOCK)
+		mutex_unlock(&f.file->f_pos_lock);
+	fdput(f);
+}
+
+SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence)
+{
+	off_t retval;
+	struct fd f = fdget_pos(fd);
+	if (!f.file)
+		return -EBADF;
+
+	retval = -EINVAL;
+	if (whence <= SEEK_MAX) {
+		loff_t res = vfs_llseek(f.file, offset, whence);
+		retval = res;
+		if (res != (loff_t)retval)
+			retval = -EOVERFLOW;	/* LFS: should only happen on 32 bit platforms */
+	}
+	fdput_pos(f);
+	return retval;
+}
+
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence)
+{
+	return sys_lseek(fd, offset, whence);
+}
+#endif
+
+#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, whence)
+{
+	int retval;
+	struct fd f = fdget_pos(fd);
+	loff_t offset;
+
+	if (!f.file)
+		return -EBADF;
+
+	retval = -EINVAL;
+	if (whence > SEEK_MAX)
+		goto out_putf;
+
+	offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low,
+			whence);
+
+	retval = (int)offset;
+	if (offset >= 0) {
+		retval = -EFAULT;
+		if (!copy_to_user(result, &offset, sizeof(offset)))
+			retval = 0;
+	}
+out_putf:
+	fdput_pos(f);
+	return retval;
+}
+#endif
+
+ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos)
+{
+	struct kiocb kiocb;
+	ssize_t ret;
+
+	if (!file->f_op->read_iter)
+		return -EINVAL;
+
+	init_sync_kiocb(&kiocb, file);
+	kiocb.ki_pos = *ppos;
+
+	iter->type |= READ;
+	ret = file->f_op->read_iter(&kiocb, iter);
+	BUG_ON(ret == -EIOCBQUEUED);
+	if (ret > 0)
+		*ppos = kiocb.ki_pos;
+	return ret;
+}
+EXPORT_SYMBOL(vfs_iter_read);
+
+ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos)
+{
+	struct kiocb kiocb;
+	ssize_t ret;
+
+	if (!file->f_op->write_iter)
+		return -EINVAL;
+
+	init_sync_kiocb(&kiocb, file);
+	kiocb.ki_pos = *ppos;
+
+	iter->type |= WRITE;
+	ret = file->f_op->write_iter(&kiocb, iter);
+	BUG_ON(ret == -EIOCBQUEUED);
+	if (ret > 0)
+		*ppos = kiocb.ki_pos;
+	return ret;
+}
+EXPORT_SYMBOL(vfs_iter_write);
+
+/*
+ * 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, const loff_t *ppos, size_t count)
+{
+	struct inode *inode;
+	loff_t pos;
+	int retval = -EINVAL;
+
+	inode = file_inode(file);
+	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_flctx && 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 ssize_t new_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;
+	struct iov_iter iter;
+	ssize_t ret;
+
+	init_sync_kiocb(&kiocb, filp);
+	kiocb.ki_pos = *ppos;
+	iov_iter_init(&iter, READ, &iov, 1, len);
+
+	ret = filp->f_op->read_iter(&kiocb, &iter);
+	BUG_ON(ret == -EIOCBQUEUED);
+	*ppos = kiocb.ki_pos;
+	return ret;
+}
+
+ssize_t __vfs_read(struct file *file, char __user *buf, size_t count,
+		   loff_t *pos)
+{
+	if (file->f_op->read)
+		return file->f_op->read(file, buf, count, pos);
+	else if (file->f_op->read_iter)
+		return new_sync_read(file, buf, count, pos);
+	else
+		return -EINVAL;
+}
+EXPORT_SYMBOL(__vfs_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_mode & FMODE_CAN_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;
+		ret = __vfs_read(file, buf, count, pos);
+		if (ret > 0) {
+			fsnotify_access(file);
+			add_rchar(current, ret);
+		}
+		inc_syscr(current);
+	}
+
+	return ret;
+}
+
+EXPORT_SYMBOL(vfs_read);
+
+static ssize_t new_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;
+	struct iov_iter iter;
+	ssize_t ret;
+
+	init_sync_kiocb(&kiocb, filp);
+	kiocb.ki_pos = *ppos;
+	iov_iter_init(&iter, WRITE, &iov, 1, len);
+
+	ret = filp->f_op->write_iter(&kiocb, &iter);
+	BUG_ON(ret == -EIOCBQUEUED);
+	if (ret > 0)
+		*ppos = kiocb.ki_pos;
+	return ret;
+}
+
+ssize_t __vfs_write(struct file *file, const char __user *p, size_t count,
+		    loff_t *pos)
+{
+	if (file->f_op->write)
+		return file->f_op->write(file, p, count, pos);
+	else if (file->f_op->write_iter)
+		return new_sync_write(file, p, count, pos);
+	else
+		return -EINVAL;
+}
+EXPORT_SYMBOL(__vfs_write);
+
+vfs_readf_t vfs_readf(struct file *file)
+{
+	const struct file_operations *fop = file->f_op;
+
+	if (fop->read)
+		return fop->read;
+	if (fop->read_iter)
+		return new_sync_read;
+	return ERR_PTR(-ENOSYS);
+}
+EXPORT_SYMBOL(vfs_readf);
+
+vfs_writef_t vfs_writef(struct file *file)
+{
+	const struct file_operations *fop = file->f_op;
+
+	if (fop->write)
+		return fop->write;
+	if (fop->write_iter)
+		return new_sync_write;
+	return ERR_PTR(-ENOSYS);
+}
+EXPORT_SYMBOL(vfs_writef);
+
+ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos)
+{
+	mm_segment_t old_fs;
+	const char __user *p;
+	ssize_t ret;
+
+	if (!(file->f_mode & FMODE_CAN_WRITE))
+		return -EINVAL;
+
+	old_fs = get_fs();
+	set_fs(get_ds());
+	p = (__force const char __user *)buf;
+	if (count > MAX_RW_COUNT)
+		count =  MAX_RW_COUNT;
+	ret = __vfs_write(file, p, count, pos);
+	set_fs(old_fs);
+	if (ret > 0) {
+		fsnotify_modify(file);
+		add_wchar(current, ret);
+	}
+	inc_syscw(current);
+	return ret;
+}
+
+EXPORT_SYMBOL(__kernel_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_mode & FMODE_CAN_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;
+		file_start_write(file);
+		ret = __vfs_write(file, buf, count, pos);
+		if (ret > 0) {
+			fsnotify_modify(file);
+			add_wchar(current, ret);
+		}
+		inc_syscw(current);
+		file_end_write(file);
+	}
+
+	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 fd f = fdget_pos(fd);
+	ssize_t ret = -EBADF;
+
+	if (f.file) {
+		loff_t pos = file_pos_read(f.file);
+		ret = vfs_read(f.file, buf, count, &pos);
+		if (ret >= 0)
+			file_pos_write(f.file, pos);
+		fdput_pos(f);
+	}
+	return ret;
+}
+
+SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf,
+		size_t, count)
+{
+	struct fd f = fdget_pos(fd);
+	ssize_t ret = -EBADF;
+
+	if (f.file) {
+		loff_t pos = file_pos_read(f.file);
+		ret = vfs_write(f.file, buf, count, &pos);
+		if (ret >= 0)
+			file_pos_write(f.file, pos);
+		fdput_pos(f);
+	}
+
+	return ret;
+}
+
+SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf,
+			size_t, count, loff_t, pos)
+{
+	struct fd f;
+	ssize_t ret = -EBADF;
+
+	if (pos < 0)
+		return -EINVAL;
+
+	f = fdget(fd);
+	if (f.file) {
+		ret = -ESPIPE;
+		if (f.file->f_mode & FMODE_PREAD)
+			ret = vfs_read(f.file, buf, count, &pos);
+		fdput(f);
+	}
+
+	return ret;
+}
+
+SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf,
+			 size_t, count, loff_t, pos)
+{
+	struct fd f;
+	ssize_t ret = -EBADF;
+
+	if (pos < 0)
+		return -EINVAL;
+
+	f = fdget(fd);
+	if (f.file) {
+		ret = -ESPIPE;
+		if (f.file->f_mode & FMODE_PWRITE)  
+			ret = vfs_write(f.file, buf, count, &pos);
+		fdput(f);
+	}
+
+	return ret;
+}
+
+/*
+ * 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);
+
+static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
+		loff_t *ppos, iter_fn_t fn)
+{
+	struct kiocb kiocb;
+	ssize_t ret;
+
+	init_sync_kiocb(&kiocb, filp);
+	kiocb.ki_pos = *ppos;
+
+	ret = fn(&kiocb, iter);
+	BUG_ON(ret == -EIOCBQUEUED);
+	*ppos = kiocb.ki_pos;
+	return ret;
+}
+
+/* Do it by hand, with file-ops */
+static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter,
+		loff_t *ppos, io_fn_t fn)
+{
+	ssize_t ret = 0;
+
+	while (iov_iter_count(iter)) {
+		struct iovec iovec = iov_iter_iovec(iter);
+		ssize_t nr;
+
+		nr = fn(filp, iovec.iov_base, iovec.iov_len, ppos);
+
+		if (nr < 0) {
+			if (!ret)
+				ret = nr;
+			break;
+		}
+		ret += nr;
+		if (nr != iovec.iov_len)
+			break;
+		iov_iter_advance(iter, nr);
+	}
+
+	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 (type >= 0
+		    && 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;
+	struct iov_iter iter;
+	ssize_t ret;
+	io_fn_t fn;
+	iter_fn_t iter_fn;
+
+	ret = import_iovec(type, uvector, nr_segs,
+			   ARRAY_SIZE(iovstack), &iov, &iter);
+	if (ret < 0)
+		return ret;
+
+	tot_len = iov_iter_count(&iter);
+	if (!tot_len)
+		goto out;
+	ret = rw_verify_area(type, file, pos, tot_len);
+	if (ret < 0)
+		goto out;
+
+	if (type == READ) {
+		fn = file->f_op->read;
+		iter_fn = file->f_op->read_iter;
+	} else {
+		fn = (io_fn_t)file->f_op->write;
+		iter_fn = file->f_op->write_iter;
+		file_start_write(file);
+	}
+
+	if (iter_fn)
+		ret = do_iter_readv_writev(file, &iter, pos, iter_fn);
+	else
+		ret = do_loop_readv_writev(file, &iter, pos, fn);
+
+	if (type != READ)
+		file_end_write(file);
+
+out:
+	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_mode & FMODE_CAN_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_mode & FMODE_CAN_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 fd f = fdget_pos(fd);
+	ssize_t ret = -EBADF;
+
+	if (f.file) {
+		loff_t pos = file_pos_read(f.file);
+		ret = vfs_readv(f.file, vec, vlen, &pos);
+		if (ret >= 0)
+			file_pos_write(f.file, pos);
+		fdput_pos(f);
+	}
+
+	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 fd f = fdget_pos(fd);
+	ssize_t ret = -EBADF;
+
+	if (f.file) {
+		loff_t pos = file_pos_read(f.file);
+		ret = vfs_writev(f.file, vec, vlen, &pos);
+		if (ret >= 0)
+			file_pos_write(f.file, pos);
+		fdput_pos(f);
+	}
+
+	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 fd f;
+	ssize_t ret = -EBADF;
+
+	if (pos < 0)
+		return -EINVAL;
+
+	f = fdget(fd);
+	if (f.file) {
+		ret = -ESPIPE;
+		if (f.file->f_mode & FMODE_PREAD)
+			ret = vfs_readv(f.file, vec, vlen, &pos);
+		fdput(f);
+	}
+
+	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 fd f;
+	ssize_t ret = -EBADF;
+
+	if (pos < 0)
+		return -EINVAL;
+
+	f = fdget(fd);
+	if (f.file) {
+		ret = -ESPIPE;
+		if (f.file->f_mode & FMODE_PWRITE)
+			ret = vfs_writev(f.file, vec, vlen, &pos);
+		fdput(f);
+	}
+
+	if (ret > 0)
+		add_wchar(current, ret);
+	inc_syscw(current);
+	return ret;
+}
+
+#ifdef CONFIG_COMPAT
+
+static ssize_t compat_do_readv_writev(int type, struct file *file,
+			       const struct compat_iovec __user *uvector,
+			       unsigned long nr_segs, loff_t *pos)
+{
+	compat_ssize_t tot_len;
+	struct iovec iovstack[UIO_FASTIOV];
+	struct iovec *iov = iovstack;
+	struct iov_iter iter;
+	ssize_t ret;
+	io_fn_t fn;
+	iter_fn_t iter_fn;
+
+	ret = compat_import_iovec(type, uvector, nr_segs,
+				  UIO_FASTIOV, &iov, &iter);
+	if (ret < 0)
+		return ret;
+
+	tot_len = iov_iter_count(&iter);
+	if (!tot_len)
+		goto out;
+	ret = rw_verify_area(type, file, pos, tot_len);
+	if (ret < 0)
+		goto out;
+
+	if (type == READ) {
+		fn = file->f_op->read;
+		iter_fn = file->f_op->read_iter;
+	} else {
+		fn = (io_fn_t)file->f_op->write;
+		iter_fn = file->f_op->write_iter;
+		file_start_write(file);
+	}
+
+	if (iter_fn)
+		ret = do_iter_readv_writev(file, &iter, pos, iter_fn);
+	else
+		ret = do_loop_readv_writev(file, &iter, pos, fn);
+
+	if (type != READ)
+		file_end_write(file);
+
+out:
+	kfree(iov);
+	if ((ret + (type == READ)) > 0) {
+		if (type == READ)
+			fsnotify_access(file);
+		else
+			fsnotify_modify(file);
+	}
+	return ret;
+}
+
+static size_t compat_readv(struct file *file,
+			   const struct compat_iovec __user *vec,
+			   unsigned long vlen, loff_t *pos)
+{
+	ssize_t ret = -EBADF;
+
+	if (!(file->f_mode & FMODE_READ))
+		goto out;
+
+	ret = -EINVAL;
+	if (!(file->f_mode & FMODE_CAN_READ))
+		goto out;
+
+	ret = compat_do_readv_writev(READ, file, vec, vlen, pos);
+
+out:
+	if (ret > 0)
+		add_rchar(current, ret);
+	inc_syscr(current);
+	return ret;
+}
+
+COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
+		const struct compat_iovec __user *,vec,
+		compat_ulong_t, vlen)
+{
+	struct fd f = fdget_pos(fd);
+	ssize_t ret;
+	loff_t pos;
+
+	if (!f.file)
+		return -EBADF;
+	pos = f.file->f_pos;
+	ret = compat_readv(f.file, vec, vlen, &pos);
+	if (ret >= 0)
+		f.file->f_pos = pos;
+	fdput_pos(f);
+	return ret;
+}
+
+static long __compat_sys_preadv64(unsigned long fd,
+				  const struct compat_iovec __user *vec,
+				  unsigned long vlen, loff_t pos)
+{
+	struct fd f;
+	ssize_t ret;
+
+	if (pos < 0)
+		return -EINVAL;
+	f = fdget(fd);
+	if (!f.file)
+		return -EBADF;
+	ret = -ESPIPE;
+	if (f.file->f_mode & FMODE_PREAD)
+		ret = compat_readv(f.file, vec, vlen, &pos);
+	fdput(f);
+	return ret;
+}
+
+#ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
+COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
+		const struct compat_iovec __user *,vec,
+		unsigned long, vlen, loff_t, pos)
+{
+	return __compat_sys_preadv64(fd, vec, vlen, pos);
+}
+#endif
+
+COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
+		const struct compat_iovec __user *,vec,
+		compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
+{
+	loff_t pos = ((loff_t)pos_high << 32) | pos_low;
+
+	return __compat_sys_preadv64(fd, vec, vlen, pos);
+}
+
+static size_t compat_writev(struct file *file,
+			    const struct compat_iovec __user *vec,
+			    unsigned long vlen, loff_t *pos)
+{
+	ssize_t ret = -EBADF;
+
+	if (!(file->f_mode & FMODE_WRITE))
+		goto out;
+
+	ret = -EINVAL;
+	if (!(file->f_mode & FMODE_CAN_WRITE))
+		goto out;
+
+	ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos);
+
+out:
+	if (ret > 0)
+		add_wchar(current, ret);
+	inc_syscw(current);
+	return ret;
+}
+
+COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
+		const struct compat_iovec __user *, vec,
+		compat_ulong_t, vlen)
+{
+	struct fd f = fdget_pos(fd);
+	ssize_t ret;
+	loff_t pos;
+
+	if (!f.file)
+		return -EBADF;
+	pos = f.file->f_pos;
+	ret = compat_writev(f.file, vec, vlen, &pos);
+	if (ret >= 0)
+		f.file->f_pos = pos;
+	fdput_pos(f);
+	return ret;
+}
+
+static long __compat_sys_pwritev64(unsigned long fd,
+				   const struct compat_iovec __user *vec,
+				   unsigned long vlen, loff_t pos)
+{
+	struct fd f;
+	ssize_t ret;
+
+	if (pos < 0)
+		return -EINVAL;
+	f = fdget(fd);
+	if (!f.file)
+		return -EBADF;
+	ret = -ESPIPE;
+	if (f.file->f_mode & FMODE_PWRITE)
+		ret = compat_writev(f.file, vec, vlen, &pos);
+	fdput(f);
+	return ret;
+}
+
+#ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
+COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
+		const struct compat_iovec __user *,vec,
+		unsigned long, vlen, loff_t, pos)
+{
+	return __compat_sys_pwritev64(fd, vec, vlen, pos);
+}
+#endif
+
+COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
+		const struct compat_iovec __user *,vec,
+		compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
+{
+	loff_t pos = ((loff_t)pos_high << 32) | pos_low;
+
+	return __compat_sys_pwritev64(fd, vec, vlen, pos);
+}
+#endif
+
+static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
+		  	   size_t count, loff_t max)
+{
+	struct fd in, out;
+	struct inode *in_inode, *out_inode;
+	loff_t pos;
+	loff_t out_pos;
+	ssize_t retval;
+	int fl;
+
+	/*
+	 * Get input file, and verify that it is ok..
+	 */
+	retval = -EBADF;
+	in = fdget(in_fd);
+	if (!in.file)
+		goto out;
+	if (!(in.file->f_mode & FMODE_READ))
+		goto fput_in;
+	retval = -ESPIPE;
+	if (!ppos) {
+		pos = in.file->f_pos;
+	} else {
+		pos = *ppos;
+		if (!(in.file->f_mode & FMODE_PREAD))
+			goto fput_in;
+	}
+	retval = rw_verify_area(READ, in.file, &pos, count);
+	if (retval < 0)
+		goto fput_in;
+	count = retval;
+
+	/*
+	 * Get output file, and verify that it is ok..
+	 */
+	retval = -EBADF;
+	out = fdget(out_fd);
+	if (!out.file)
+		goto fput_in;
+	if (!(out.file->f_mode & FMODE_WRITE))
+		goto fput_out;
+	retval = -EINVAL;
+	in_inode = file_inode(in.file);
+	out_inode = file_inode(out.file);
+	out_pos = out.file->f_pos;
+	retval = rw_verify_area(WRITE, out.file, &out_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);
+
+	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
+	file_start_write(out.file);
+	retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
+	file_end_write(out.file);
+
+	if (retval > 0) {
+		add_rchar(current, retval);
+		add_wchar(current, retval);
+		fsnotify_access(in.file);
+		fsnotify_modify(out.file);
+		out.file->f_pos = out_pos;
+		if (ppos)
+			*ppos = pos;
+		else
+			in.file->f_pos = pos;
+	}
+
+	inc_syscr(current);
+	inc_syscw(current);
+	if (pos > max)
+		retval = -EOVERFLOW;
+
+fput_out:
+	fdput(out);
+fput_in:
+	fdput(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);
+}
+
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd,
+		compat_off_t __user *, offset, compat_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);
+}
+
+COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
+		compat_loff_t __user *, offset, compat_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);
+}
+#endif