Tao Ma
2010-Jan-27 02:21 UTC
[Ocfs2-devel] [PATCH] 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 at oracle.com>
---
fs/ocfs2/ioctl.c | 14 +++++++++++++-
1 files changed, 13 insertions(+), 1 deletions(-)
diff --git a/fs/ocfs2/ioctl.c b/fs/ocfs2/ioctl.c
index 31fbb06..7d9d9c1 100644
--- a/fs/ocfs2/ioctl.c
+++ b/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 @@ long ocfs2_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg)
#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 @@ long ocfs2_compat_ioctl(struct file *file, unsigned cmd,
unsigned long arg)
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;
}
--
1.5.5