[PATCH] Revert "debugfs: inode: debugfs_create_dir uses mode permission from parent"

[PATCH] Revert "debugfs: inode: debugfs_create_dir uses mode permission from parent"

[Thomas Richter]

This reverts commit 95cde3c59966f6371b6bcd9e4e2da2ba64ee9775.
It breaks the ioctl(KVM_CREATE_VM) interface.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
---
 fs/debugfs/inode.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index a913b12fc7f8..13b01351dd1c 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -512,9 +512,7 @@ struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
 	if (unlikely(!inode))
 		return failed_creating(dentry);
 
-	if (!parent)
-		parent = debugfs_mount->mnt_root;
-	inode->i_mode = S_IFDIR | ((d_inode(parent)->i_mode & 0770));
+	inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
 	inode->i_op = &simple_dir_inode_operations;
 	inode->i_fop = &simple_dir_operations;
 
-- 
2.14.3

Re: [PATCH] Revert "debugfs: inode: debugfs_create_dir uses mode permission from parent"

[Laura Abbott]

On 06/11/2018 02:28 AM, Thomas Richter wrote:
> This reverts commit 95cde3c59966f6371b6bcd9e4e2da2ba64ee9775.
> It breaks the ioctl(KVM_CREATE_VM) interface.
> 

Can you elaborate a little more on how this breaks? Fedora has
gotten at least one report of a failure in this ioctl and
I'd like know if it's the same issue.

Thanks,
Laura

> Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
> ---
>   fs/debugfs/inode.c | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
> index a913b12fc7f8..13b01351dd1c 100644
> --- a/fs/debugfs/inode.c
> +++ b/fs/debugfs/inode.c
> @@ -512,9 +512,7 @@ struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
>   	if (unlikely(!inode))
>   		return failed_creating(dentry);
>   
> -	if (!parent)
> -		parent = debugfs_mount->mnt_root;
> -	inode->i_mode = S_IFDIR | ((d_inode(parent)->i_mode & 0770));
> +	inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
>   	inode->i_op = &simple_dir_inode_operations;
>   	inode->i_fop = &simple_dir_operations;
>   
> 

Re: [PATCH] Revert "debugfs: inode: debugfs_create_dir uses mode permission from parent"

[Mike Galbraith]

On Mon, 2018-06-11 at 11:12 -0700, Laura Abbott wrote:
> On 06/11/2018 02:28 AM, Thomas Richter wrote:
> > This reverts commit 95cde3c59966f6371b6bcd9e4e2da2ba64ee9775.
> > It breaks the ioctl(KVM_CREATE_VM) interface.
> > 
> 
> Can you elaborate a little more on how this breaks? Fedora has
> gotten at least one report of a failure in this ioctl and
> I'd like know if it's the same issue.

What I reported is here https://lkml.org/lkml/2018/6/8/79

	-Mike