[PATCH] v9fs: remove additional buffer allocation from v9fs_file_read and v9fs_file_write (19cba8ab) · Commits · 戴 / test

fs/9p/vfs_file.c

+33 −81

Original line number	Original line	Diff line number	Diff line
	@@ -175,16 +175,16 @@ static int v9fs_file_lock(struct file filp, int cmd, struct file_lock fl)
	}		}

	/**		/**
	* v9fs_read - read from a file (internal)		* v9fs_file_read - read from a file
	* @filep: file pointer to read		* @filep: file pointer to read
	* @data: data buffer to read data into		* @data: data buffer to read data into
	* @count: size of buffer		* @count: size of buffer
	* @offset: offset at which to read data		* @offset: offset at which to read data
	*		*
	*/		*/

	static ssize_t		static ssize_t
	v9fs_read(struct file filp, char buffer, size_t count, loff_t * offset)		v9fs_file_read(struct file filp, char __user data, size_t count,
			loff_t * offset)
	{		{
	struct inode *inode = filp->f_dentry->d_inode;		struct inode *inode = filp->f_dentry->d_inode;
	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);		struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
	@@ -194,6 +194,7 @@ v9fs_read(struct file filp, char buffer, size_t count, loff_t * offset)
	int rsize = 0;		int rsize = 0;
	int result = 0;		int result = 0;
	int total = 0;		int total = 0;
			int n;

	dprintk(DEBUG_VFS, "\n");		dprintk(DEBUG_VFS, "\n");

	@@ -216,10 +217,15 @@ v9fs_read(struct file filp, char buffer, size_t count, loff_t * offset)
	} else		} else
	*offset += result;		*offset += result;

	/* XXX - extra copy */		n = copy_to_user(data, fcall->params.rread.data, result);
	memcpy(buffer, fcall->params.rread.data, result);		if (n) {
			dprintk(DEBUG_ERROR, "Problem copying to user %d\n", n);
			kfree(fcall);
			return -EFAULT;
			}

	count -= result;		count -= result;
	buffer += result;		data += result;
	total += result;		total += result;

	kfree(fcall);		kfree(fcall);
	@@ -232,42 +238,7 @@ v9fs_read(struct file filp, char buffer, size_t count, loff_t * offset)
	}		}

	/**		/**
	* v9fs_file_read - read from a file		* v9fs_file_write - write to a file
	* @filep: file pointer to read
	* @data: data buffer to read data into
	* @count: size of buffer
	* @offset: offset at which to read data
	*
	*/

	static ssize_t
	v9fs_file_read(struct file filp, char __user data, size_t count,
	loff_t * offset)
	{
	int retval = -1;
	int ret = 0;
	char *buffer;

	buffer = kmalloc(count, GFP_KERNEL);
	if (!buffer)
	return -ENOMEM;

	retval = v9fs_read(filp, buffer, count, offset);
	if (retval > 0) {
	if ((ret = copy_to_user(data, buffer, retval)) != 0) {
	dprintk(DEBUG_ERROR, "Problem copying to user %d\n",
	ret);
	retval = ret;
	}
	}

	kfree(buffer);

	return retval;
	}

	/**
	* v9fs_write - write to a file
	* @filep: file pointer to write		* @filep: file pointer to write
	* @data: data buffer to write data from		* @data: data buffer to write data from
	* @count: size of buffer		* @count: size of buffer
	@@ -276,7 +247,8 @@ v9fs_file_read(struct file filp, char __user data, size_t count,
	*/		*/

	static ssize_t		static ssize_t
	v9fs_write(struct file filp, char buffer, size_t count, loff_t * offset)		v9fs_file_write(struct file filp, const char __user data,
			size_t count, loff_t * offset)
	{		{
	struct inode *inode = filp->f_dentry->d_inode;		struct inode *inode = filp->f_dentry->d_inode;
	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);		struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
	@@ -286,30 +258,42 @@ v9fs_write(struct file filp, char buffer, size_t count, loff_t * offset)
	int result = -EIO;		int result = -EIO;
	int rsize = 0;		int rsize = 0;
	int total = 0;		int total = 0;
			char *buf;

	dprintk(DEBUG_VFS, "data %p count %d offset %x\n", buffer, (int)count,		dprintk(DEBUG_VFS, "data %p count %d offset %x\n", data, (int)count,
	(int)*offset);		(int)*offset);
	rsize = v9ses->maxdata - V9FS_IOHDRSZ;		rsize = v9ses->maxdata - V9FS_IOHDRSZ;
	if (v9fid->iounit != 0 && rsize > v9fid->iounit)		if (v9fid->iounit != 0 && rsize > v9fid->iounit)
	rsize = v9fid->iounit;		rsize = v9fid->iounit;

	dump_data(buffer, count);		buf = kmalloc(v9ses->maxdata - V9FS_IOHDRSZ, GFP_KERNEL);
			if (!buf)
			return -ENOMEM;

	do {		do {
	if (count < rsize)		if (count < rsize)
	rsize = count;		rsize = count;

	result =		result = copy_from_user(buf, data, rsize);
	v9fs_t_write(v9ses, fid, *offset, rsize, buffer, &fcall);		if (result) {
			dprintk(DEBUG_ERROR, "Problem copying from user\n");
			kfree(buf);
			return -EFAULT;
			}

			dump_data(buf, rsize);
			result = v9fs_t_write(v9ses, fid, *offset, rsize, buf, &fcall);
	if (result < 0) {		if (result < 0) {
	eprintk(KERN_ERR, "error while writing: %s(%d)\n",		eprintk(KERN_ERR, "error while writing: %s(%d)\n",
	FCALL_ERROR(fcall), result);		FCALL_ERROR(fcall), result);
	kfree(fcall);		kfree(fcall);
			kfree(buf);
	return result;		return result;
	} else		} else
	*offset += result;		*offset += result;

	kfree(fcall);		kfree(fcall);
			fcall = NULL;

	if (result != rsize) {		if (result != rsize) {
	eprintk(KERN_ERR,		eprintk(KERN_ERR,
	@@ -319,46 +303,14 @@ v9fs_write(struct file filp, char buffer, size_t count, loff_t * offset)
	}		}

	count -= result;		count -= result;
	buffer += result;		data += result;
	total += result;		total += result;
	} while (count);		} while (count);

			kfree(buf);
	return total;		return total;
	}		}

	/**
	* v9fs_file_write - write to a file
	* @filep: file pointer to write
	* @data: data buffer to write data from
	* @count: size of buffer
	* @offset: offset at which to write data
	*
	*/

	static ssize_t
	v9fs_file_write(struct file filp, const char __user data,
	size_t count, loff_t * offset)
	{
	int ret = -1;
	char *buffer;

	buffer = kmalloc(count, GFP_KERNEL);
	if (buffer == NULL)
	return -ENOMEM;

	ret = copy_from_user(buffer, data, count);
	if (ret) {
	dprintk(DEBUG_ERROR, "Problem copying from user\n");
	ret = -EFAULT;
	} else {
	ret = v9fs_write(filp, buffer, count, offset);
	}

	kfree(buffer);

	return ret;
	}

	struct file_operations v9fs_file_operations = {		struct file_operations v9fs_file_operations = {
	.llseek = generic_file_llseek,		.llseek = generic_file_llseek,
	.read = v9fs_file_read,		.read = v9fs_file_read,

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