Import of Linux/MIPS 2.1.14

1 files changed, 236 insertions, 88 deletions

diff --git a/fs/read_write.c b/fs/read_write.c
index 1cd19d57a..6c28b8f59 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -9,133 +9,281 @@
 #include <linux/stat.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
+#include <linux/fcntl.h>
+#include <linux/file.h>
 #include <linux/mm.h>
+#include <linux/uio.h>
 
-#include <asm/segment.h>
+#include <asm/uaccess.h>
 
-asmlinkage int sys_lseek(unsigned int fd, off_t offset, unsigned int origin)
+static long long default_llseek(struct inode *inode,
+	struct file *file,
+	long long offset,
+	int origin)
 {
-	struct file * file;
-	int tmp = -1;
-
-	if (fd >= NR_OPEN || !(file=current->files->fd[fd]) || !(file->f_inode))
-		return -EBADF;
-	if (origin > 2)
-		return -EINVAL;
-	if (file->f_op && file->f_op->lseek)
-		return file->f_op->lseek(file->f_inode,file,offset,origin);
+	long long retval;
 
-/* this is the default handler if no lseek handler is present */
 	switch (origin) {
-		case 0:
-			tmp = offset;
-			break;
-		case 1:
-			tmp = file->f_pos + offset;
-			break;
 		case 2:
-			if (!file->f_inode)
-				return -EINVAL;
-			tmp = file->f_inode->i_size + offset;
+			offset += inode->i_size;
 			break;
+		case 1:
+			offset += file->f_pos;
 	}
-	if (tmp < 0)
-		return -EINVAL;
-	if (tmp != file->f_pos) {
-		file->f_pos = tmp;
-		file->f_reada = 0;
-		file->f_version = ++event;
+	retval = -EINVAL;
+	if (offset >= 0) {
+		if (offset != file->f_pos) {
+			file->f_pos = offset;
+			file->f_reada = 0;
+			file->f_version = ++event;
+		}
+		retval = offset;
 	}
-	return file->f_pos;
+	return retval;
+}
+
+static inline long long llseek(struct inode * inode, struct file *file,
+	long long offset, unsigned int origin)
+{
+	long long (*fn)(struct inode *, struct file *, long long, int);
+
+	fn = default_llseek;
+	if (file->f_op && file->f_op->llseek)
+		fn = file->f_op->llseek;
+	return fn(inode, file, offset, origin);
+}
+
+asmlinkage long sys_lseek(unsigned int fd, off_t offset, unsigned int origin)
+{
+	long retval;
+	struct file * file;
+	struct inode * inode;
+
+	retval = -EBADF;
+	if (fd >= NR_OPEN ||
+	    !(file = current->files->fd[fd]) ||
+	    !(inode = file->f_inode))
+		goto bad;
+	retval = -EINVAL;
+	if (origin > 2)
+		goto bad;
+	retval = llseek(inode, file, offset, origin);
+bad:
+	return retval;
 }
 
 asmlinkage int sys_llseek(unsigned int fd, unsigned long offset_high,
 			  unsigned long offset_low, loff_t * result,
 			  unsigned int origin)
 {
+	long retval;
 	struct file * file;
-	loff_t tmp = -1;
-	loff_t offset;
-	int err;
+	struct inode * inode;
+	long long offset;
 
-	if (fd >= NR_OPEN || !(file=current->files->fd[fd]) || !(file->f_inode))
-		return -EBADF;
+	retval = -EBADF;
+	if (fd >= NR_OPEN ||
+	    !(file = current->files->fd[fd]) ||
+	    !(inode = file->f_inode))
+		goto bad;
+	retval = -EINVAL;
 	if (origin > 2)
-		return -EINVAL;
-	if ((err = verify_area(VERIFY_WRITE, result, sizeof(loff_t))))
-		return err;
-	offset = (loff_t) (((unsigned long long) offset_high << 32) | offset_low);
-/* there is no fs specific llseek handler */
-	switch (origin) {
-		case 0:
-			tmp = offset;
-			break;
-		case 1:
-			tmp = file->f_pos + offset;
-			break;
-		case 2:
-			if (!file->f_inode)
-				return -EINVAL;
-			tmp = file->f_inode->i_size + offset;
-			break;
+		goto bad;
+
+	offset = llseek(inode, file,
+		(((unsigned long long) offset_high << 32) | offset_low),
+		origin);
+
+	retval = offset;
+	if (offset >= 0) {
+		retval = copy_to_user(result, &offset, sizeof(offset));
+		if (retval)
+			retval = -EFAULT;
 	}
-	if (tmp < 0)
-		return -EINVAL;
-	file->f_pos = tmp;
-	file->f_reada = 0;
-	file->f_version = ++event;
-	memcpy_tofs(result, &file->f_pos, sizeof(loff_t));
-	return 0;
+
+bad:
+	return retval;
 }
 
-asmlinkage int sys_read(unsigned int fd,char * buf,unsigned int count)
+asmlinkage long sys_read(unsigned int fd, char * buf, unsigned long count)
 {
 	int error;
 	struct file * file;
 	struct inode * inode;
+	long (*read)(struct inode *, struct file *, char *, unsigned long);
 
-	if (fd>=NR_OPEN || !(file=current->files->fd[fd]) || !(inode=file->f_inode))
-		return -EBADF;
+	error = -EBADF;
+	file = fget(fd);
+	if (!file)
+		goto bad_file;
+	inode = file->f_inode;
+	if (!inode)
+		goto out;
+	error = -EBADF;
 	if (!(file->f_mode & 1))
-		return -EBADF;
-	if (!file->f_op || !file->f_op->read)
-		return -EINVAL;
-	if (!count)
-		return 0;
-	error = verify_area(VERIFY_WRITE,buf,count);
+		goto out;
+	error = locks_verify_area(FLOCK_VERIFY_READ,inode,file,file->f_pos,count);
 	if (error)
-		return error;
-	return file->f_op->read(inode,file,buf,count);
+		goto out;
+	error = -EINVAL;
+	if (!file->f_op || !(read = file->f_op->read))
+		goto out;
+	error = read(inode,file,buf,count);
+out:
+	fput(file, inode);
+bad_file:
+	return error;
 }
 
-asmlinkage int sys_write(unsigned int fd,char * buf,unsigned int count)
+asmlinkage long sys_write(unsigned int fd, const char * buf, unsigned long count)
 {
 	int error;
 	struct file * file;
 	struct inode * inode;
-	int written;
-	
-	if (fd>=NR_OPEN || !(file=current->files->fd[fd]) || !(inode=file->f_inode))
-		return -EBADF;
+	long (*write)(struct inode *, struct file *, const char *, unsigned long);
+
+	error = -EBADF;
+	file = fget(fd);
+	if (!file)
+		goto bad_file;
+	inode = file->f_inode;
+	if (!inode)
+		goto out;
 	if (!(file->f_mode & 2))
-		return -EBADF;
-	if (!file->f_op || !file->f_op->write)
-		return -EINVAL;
+		goto out;
+	error = locks_verify_area(FLOCK_VERIFY_WRITE,inode,file,file->f_pos,count);
+	if (error)
+		goto out;
+	error = -EINVAL;
+	if (!file->f_op || !(write = file->f_op->write))
+		goto out;
+	down(&inode->i_sem);
+	error = write(inode,file,buf,count);
+	up(&inode->i_sem);
+out:
+	fput(file, inode);
+bad_file:
+	return error;
+}
+
+static long sock_readv_writev(int type, struct inode * inode, struct file * file,
+	const struct iovec * iov, long count, long size)
+{
+	struct msghdr msg;
+	struct socket *sock;
+
+	sock = &inode->u.socket_i;
+	if (!sock->ops)
+		return -EOPNOTSUPP;
+	msg.msg_name = NULL;
+	msg.msg_namelen = 0;
+	msg.msg_control = NULL;
+	msg.msg_iov = (struct iovec *) iov;
+	msg.msg_iovlen = count;
+
+	/* read() does a VERIFY_WRITE */
+	if (type == VERIFY_WRITE) {
+		if (!sock->ops->recvmsg)
+			return -EOPNOTSUPP;
+		return sock->ops->recvmsg(sock, &msg, size,
+			(file->f_flags & O_NONBLOCK), 0, NULL);
+	}
+	if (!sock->ops->sendmsg)
+		return -EOPNOTSUPP;
+	return sock->ops->sendmsg(sock, &msg, size,
+		(file->f_flags & O_NONBLOCK), 0);
+}
+
+typedef long (*IO_fn_t)(struct inode *, struct file *, char *, unsigned long);
+
+static long do_readv_writev(int type, struct inode * inode, struct file * file,
+	const struct iovec * vector, unsigned long count)
+{
+	unsigned long tot_len;
+	struct iovec iov[UIO_MAXIOV];
+	long retval, i;
+	IO_fn_t fn;
+
+	/*
+	 * First get the "struct iovec" from user memory and
+	 * verify all the pointers
+	 */
 	if (!count)
 		return 0;
-	error = verify_area(VERIFY_READ,buf,count);
-	if (error)
-		return error;
-	written = file->f_op->write(inode,file,buf,count);
+	if (count > UIO_MAXIOV)
+		return -EINVAL;
+	if (copy_from_user(iov, vector, count*sizeof(*vector)))
+		return -EFAULT;
+	tot_len = 0;
+	for (i = 0 ; i < count ; i++)
+		tot_len += iov[i].iov_len;
+
+	retval = locks_verify_area(type == VERIFY_READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE,
+				   inode, file, file->f_pos, tot_len);
+	if (retval)
+		return retval;
+
 	/*
-	 * If data has been written to the file, remove the setuid and
-	 * the setgid bits
+	 * Then do the actual IO.  Note that sockets need to be handled
+	 * specially as they have atomicity guarantees and can handle
+	 * iovec's natively
 	 */
-	if (written > 0 && !suser() && (inode->i_mode & (S_ISUID | S_ISGID))) {
-		struct iattr newattrs;
-		newattrs.ia_mode = inode->i_mode & ~(S_ISUID | S_ISGID);
-		newattrs.ia_valid = ATTR_MODE;
-		notify_change(inode, &newattrs);
+	if (inode->i_sock)
+		return sock_readv_writev(type, inode, file, iov, count, tot_len);
+
+	if (!file->f_op)
+		return -EINVAL;
+	/* VERIFY_WRITE actually means a read, as we write to user space */
+	fn = file->f_op->read;
+	if (type == VERIFY_READ)
+		fn = (IO_fn_t) file->f_op->write;		
+	vector = iov;
+	while (count > 0) {
+		void * base;
+		int len, nr;
+
+		base = vector->iov_base;
+		len = vector->iov_len;
+		vector++;
+		count--;
+		nr = fn(inode, file, base, len);
+		if (nr < 0) {
+			if (retval)
+				break;
+			retval = nr;
+			break;
+		}
+		retval += nr;
+		if (nr != len)
+			break;
 	}
-	return written;
+	return retval;
+}
+
+asmlinkage long sys_readv(unsigned long fd, const struct iovec * vector, unsigned long count)
+{
+	struct file * file;
+	struct inode * inode;
+
+	if (fd >= NR_OPEN || !(file = current->files->fd[fd]) || !(inode = file->f_inode))
+		return -EBADF;
+	if (!(file->f_mode & 1))
+		return -EBADF;
+	return do_readv_writev(VERIFY_WRITE, inode, file, vector, count);
+}
+
+asmlinkage long sys_writev(unsigned long fd, const struct iovec * vector, unsigned long count)
+{
+	int error;
+	struct file * file;
+	struct inode * inode;
+
+	if (fd >= NR_OPEN || !(file = current->files->fd[fd]) || !(inode = file->f_inode))
+		return -EBADF;
+	if (!(file->f_mode & 2))
+		return -EBADF;
+	down(&inode->i_sem);
+	error = do_readv_writev(VERIFY_READ, inode, file, vector, count);
+	up(&inode->i_sem);
+	return error;
 }