ocfs2: Use compat_ptr in reflink_arguments.

Although we use u64 to pass userspace pointers to the kernel to avoid compat_ioctl, it doesn't work in some ppc platform. So wrap them with compat_ptr and add compat_ioctl. The detailed discussion about compat_ptr can be found in thread http://lkml.org/lkml/2009/10/27/423. We indeed met with a bug when testing on ppc(-EFAULT is returned when using old_path). This patch try to fix this. I have tested in ppc64(with 32 bit reflink) and x86_64(with i686 reflink), both works. Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>

ocfs2: Use compat_ptr in reflink_arguments.
Although we use u64 to pass userspace pointers to the kernel to avoid compat_ioctl, it doesn't work in some ppc platform. So wrap them with compat_ptr and add compat_ioctl. The detailed discussion about compat_ptr can be found in thread http://lkml.org/lkml/2009/10/27/423. We indeed met with a bug when testing on ppc(-EFAULT is returned when using old_path). This patch try to fix this. I have tested in ppc64(with 32 bit reflink) and x86_64(with i686 reflink), both works. Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
Tao Ma · Joel Becker
1 parent cd34edd8cf
Showing 1 changed file with 13 additions and 1 deletions Side-by-side Diff
fs/ocfs2/ioctl.c
@@ -7,6 +7,7 @@
  
 #include <linux/fs.h>
 #include <linux/mount.h>
+#include <linux/compat.h>
  
 #define MLOG_MASK_PREFIX ML_INODE
 #include <cluster/masklog.h>
@@ -181,6 +182,10 @@
 #ifdef CONFIG_COMPAT
 long ocfs2_compat_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 {
+	bool preserve;
+	struct reflink_arguments args;
+	struct inode *inode = file->f_path.dentry->d_inode;
+
 	switch (cmd) {
 	case OCFS2_IOC32_GETFLAGS:
 		cmd = OCFS2_IOC_GETFLAGS;
  
@@ -195,8 +200,15 @@
 	case OCFS2_IOC_GROUP_EXTEND:
 	case OCFS2_IOC_GROUP_ADD:
 	case OCFS2_IOC_GROUP_ADD64:
-	case OCFS2_IOC_REFLINK:
 		break;
+	case OCFS2_IOC_REFLINK:
+		if (copy_from_user(&args, (struct reflink_arguments *)arg,
+				   sizeof(args)))
+			return -EFAULT;
+		preserve = (args.preserve != 0);
+
+		return ocfs2_reflink_ioctl(inode, compat_ptr(args.old_path),
+					   compat_ptr(args.new_path), preserve);
 	default:
 		return -ENOIOCTLCMD;
 	}
...	...	@@ -7,6 +7,7 @@
7	7
8	8	#include <linux/fs.h>
9	9	#include <linux/mount.h>
	10	+#include <linux/compat.h>
10	11
11	12	#define MLOG_MASK_PREFIX ML_INODE
12	13	#include <cluster/masklog.h>
...	...	@@ -181,6 +182,10 @@
181	182	#ifdef CONFIG_COMPAT
182	183	long ocfs2_compat_ioctl(struct file *file, unsigned cmd, unsigned long arg)
183	184	{
	185	+ bool preserve;
	186	+ struct reflink_arguments args;
	187	+ struct inode *inode = file->f_path.dentry->d_inode;
	188	+
184	189	switch (cmd) {
185	190	case OCFS2_IOC32_GETFLAGS:
186	191	cmd = OCFS2_IOC_GETFLAGS;
187	192
...	...	@@ -195,8 +200,15 @@
195	200	case OCFS2_IOC_GROUP_EXTEND:
196	201	case OCFS2_IOC_GROUP_ADD:
197	202	case OCFS2_IOC_GROUP_ADD64:
198		- case OCFS2_IOC_REFLINK:
199	203	break;
	204	+ case OCFS2_IOC_REFLINK:
	205	+ if (copy_from_user(&args, (struct reflink_arguments *)arg,
	206	+ sizeof(args)))
	207	+ return -EFAULT;
	208	+ preserve = (args.preserve != 0);
	209	+
	210	+ return ocfs2_reflink_ioctl(inode, compat_ptr(args.old_path),
	211	+ compat_ptr(args.new_path), preserve);
200	212	default:
201	213	return -ENOIOCTLCMD;
202	214	}