ovl: let helper ovl_i_path_real() return the realinode

[ Upstream commit b2dd05f107b11966e26fe52a313b418364cf497b ]

Let helper ovl_i_path_real() return the realinode to prepare for
checking non-null realinode in RCU walking path.

[msz] Use d_inode_rcu() since we are depending on the consitency
between dentry and inode being non-NULL in an RCU setting.

There are some changes from upstream commit:
1. Context conflicts caused by 73db6a063c785bc ("ovl: port to
   vfs{g,u}id_t and associated helpers") is handled.

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Fixes: ffa5723c6d25 ("ovl: store lower path in ovl_inode")
Cc: <stable@vger.kernel.org> # v5.19
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Zhihao Cheng 2023-07-17 11:09:03 +08:00 committed by Greg Kroah-Hartman
parent 000a9a72ef
commit 06b3f0bf41
2 changed files with 5 additions and 4 deletions

View File

@ -369,7 +369,7 @@ enum ovl_path_type ovl_path_type(struct dentry *dentry);
void ovl_path_upper(struct dentry *dentry, struct path *path);
void ovl_path_lower(struct dentry *dentry, struct path *path);
void ovl_path_lowerdata(struct dentry *dentry, struct path *path);
void ovl_i_path_real(struct inode *inode, struct path *path);
struct inode *ovl_i_path_real(struct inode *inode, struct path *path);
enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path);
struct dentry *ovl_dentry_upper(struct dentry *dentry);

View File

@ -266,7 +266,7 @@ struct dentry *ovl_i_dentry_upper(struct inode *inode)
return ovl_upperdentry_dereference(OVL_I(inode));
}
void ovl_i_path_real(struct inode *inode, struct path *path)
struct inode *ovl_i_path_real(struct inode *inode, struct path *path)
{
path->dentry = ovl_i_dentry_upper(inode);
if (!path->dentry) {
@ -275,6 +275,8 @@ void ovl_i_path_real(struct inode *inode, struct path *path)
} else {
path->mnt = ovl_upper_mnt(OVL_FS(inode->i_sb));
}
return path->dentry ? d_inode_rcu(path->dentry) : NULL;
}
struct inode *ovl_inode_upper(struct inode *inode)
@ -1121,8 +1123,7 @@ void ovl_copyattr(struct inode *inode)
struct inode *realinode;
struct user_namespace *real_mnt_userns;
ovl_i_path_real(inode, &realpath);
realinode = d_inode(realpath.dentry);
realinode = ovl_i_path_real(inode, &realpath);
real_mnt_userns = mnt_user_ns(realpath.mnt);
inode->i_uid = i_uid_into_mnt(real_mnt_userns, realinode);