fs: make helpers idmap mount aware

Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.

As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.

Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

1 files changed, 17 insertions, 14 deletions

diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index 984f28315d2a..1dc7af046615 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -33,8 +33,8 @@
 #include "acl.h"
 
 static int
-v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
-		    dev_t rdev);
+v9fs_vfs_mknod_dotl(struct user_namespace *mnt_userns, struct inode *dir,
+		    struct dentry *dentry, umode_t omode, dev_t rdev);
 
 /**
  * v9fs_get_fsgid_for_create - Helper function to get the gid for creating a
@@ -218,10 +218,10 @@ int v9fs_open_to_dotl_flags(int flags)
  */
 
 static int
-v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
-		bool excl)
+v9fs_vfs_create_dotl(struct user_namespace *mnt_userns, struct inode *dir,
+		     struct dentry *dentry, umode_t omode, bool excl)
 {
-	return v9fs_vfs_mknod_dotl(dir, dentry, omode, 0);
+	return v9fs_vfs_mknod_dotl(mnt_userns, dir, dentry, omode, 0);
 }
 
 static int
@@ -367,8 +367,9 @@ err_clunk_old_fid:
  *
  */
 
-static int v9fs_vfs_mkdir_dotl(struct inode *dir,
-			       struct dentry *dentry, umode_t omode)
+static int v9fs_vfs_mkdir_dotl(struct user_namespace *mnt_userns,
+			       struct inode *dir, struct dentry *dentry,
+			       umode_t omode)
 {
 	int err;
 	struct v9fs_session_info *v9ses;
@@ -457,8 +458,9 @@ error:
 }
 
 static int
-v9fs_vfs_getattr_dotl(const struct path *path, struct kstat *stat,
-		 u32 request_mask, unsigned int flags)
+v9fs_vfs_getattr_dotl(struct user_namespace *mnt_userns,
+		      const struct path *path, struct kstat *stat,
+		      u32 request_mask, unsigned int flags)
 {
 	struct dentry *dentry = path->dentry;
 	struct v9fs_session_info *v9ses;
@@ -540,7 +542,8 @@ static int v9fs_mapped_iattr_valid(int iattr_valid)
  *
  */
 
-int v9fs_vfs_setattr_dotl(struct dentry *dentry, struct iattr *iattr)
+int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns,
+			  struct dentry *dentry, struct iattr *iattr)
 {
 	int retval, use_dentry = 0;
 	struct p9_fid *fid = NULL;
@@ -684,8 +687,8 @@ v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode,
 }
 
 static int
-v9fs_vfs_symlink_dotl(struct inode *dir, struct dentry *dentry,
-		const char *symname)
+v9fs_vfs_symlink_dotl(struct user_namespace *mnt_userns, struct inode *dir,
+		      struct dentry *dentry, const char *symname)
 {
 	int err;
 	kgid_t gid;
@@ -824,8 +827,8 @@ v9fs_vfs_link_dotl(struct dentry *old_dentry, struct inode *dir,
  *
  */
 static int
-v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
-		dev_t rdev)
+v9fs_vfs_mknod_dotl(struct user_namespace *mnt_userns, struct inode *dir,
+		    struct dentry *dentry, umode_t omode, dev_t rdev)
 {
 	int err;
 	kgid_t gid;