[PATCH 03/18] ovl: stack miscattr

From: Miklos Szeredi
Date: Wed Feb 03 2021 - 07:44:14 EST


Add stacking for the miscattr operations.

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
---
fs/overlayfs/dir.c | 2 ++
fs/overlayfs/inode.c | 43 ++++++++++++++++++++++++++++++++++++++++
fs/overlayfs/overlayfs.h | 2 ++
3 files changed, 47 insertions(+)

diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 28a075b5f5b2..77c6b44f8d83 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -1300,4 +1300,6 @@ const struct inode_operations ovl_dir_inode_operations = {
.listxattr = ovl_listxattr,
.get_acl = ovl_get_acl,
.update_time = ovl_update_time,
+ .miscattr_get = ovl_miscattr_get,
+ .miscattr_set = ovl_miscattr_set,
};
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index d739e14c6814..97d36d1f28c3 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -11,6 +11,7 @@
#include <linux/posix_acl.h>
#include <linux/ratelimit.h>
#include <linux/fiemap.h>
+#include <linux/miscattr.h>
#include "overlayfs.h"


@@ -495,6 +496,46 @@ static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
return err;
}

+int ovl_miscattr_set(struct dentry *dentry, struct miscattr *ma)
+{
+ struct inode *inode = d_inode(dentry);
+ struct dentry *upperdentry;
+ const struct cred *old_cred;
+ int err;
+
+ err = ovl_want_write(dentry);
+ if (err)
+ goto out;
+
+ err = ovl_copy_up(dentry);
+ if (!err) {
+ upperdentry = ovl_dentry_upper(dentry);
+
+ old_cred = ovl_override_creds(inode->i_sb);
+ /* err = security_file_ioctl(real.file, cmd, arg); */
+ err = vfs_miscattr_set(upperdentry, ma);
+ revert_creds(old_cred);
+ ovl_copyflags(ovl_inode_real(inode), inode);
+ }
+ ovl_drop_write(dentry);
+out:
+ return err;
+}
+
+int ovl_miscattr_get(struct dentry *dentry, struct miscattr *ma)
+{
+ struct inode *inode = d_inode(dentry);
+ struct dentry *realdentry = ovl_dentry_real(dentry);
+ const struct cred *old_cred;
+ int err;
+
+ old_cred = ovl_override_creds(inode->i_sb);
+ err = vfs_miscattr_get(realdentry, ma);
+ revert_creds(old_cred);
+
+ return err;
+}
+
static const struct inode_operations ovl_file_inode_operations = {
.setattr = ovl_setattr,
.permission = ovl_permission,
@@ -503,6 +544,8 @@ static const struct inode_operations ovl_file_inode_operations = {
.get_acl = ovl_get_acl,
.update_time = ovl_update_time,
.fiemap = ovl_fiemap,
+ .miscattr_get = ovl_miscattr_get,
+ .miscattr_set = ovl_miscattr_set,
};

static const struct inode_operations ovl_symlink_inode_operations = {
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index b487e48c7fd4..d3ad02c34cca 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -509,6 +509,8 @@ int __init ovl_aio_request_cache_init(void);
void ovl_aio_request_cache_destroy(void);
long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
long ovl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+int ovl_miscattr_get(struct dentry *dentry, struct miscattr *ma);
+int ovl_miscattr_set(struct dentry *dentry, struct miscattr *ma);

/* copy_up.c */
int ovl_copy_up(struct dentry *dentry);
--
2.26.2