fs: port acl to mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

18 files changed, 65 insertions, 72 deletions

diff --git a/fs/9p/acl.c b/fs/9p/acl.c
index ae278016ae95..33036305b4fd 100644
--- a/fs/9p/acl.c
+++ b/fs/9p/acl.c
@@ -206,7 +206,7 @@ int v9fs_iop_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 			struct iattr iattr = {};
 			struct posix_acl *acl_mode = acl;
 
-			retval = posix_acl_update_mode(&init_user_ns, inode,
+			retval = posix_acl_update_mode(&nop_mnt_idmap, inode,
 						       &iattr.ia_mode,
 						       &acl_mode);
 			if (retval)
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
index 7a3ab7e4b163..7427449a04a3 100644
--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -114,12 +114,11 @@ int btrfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct posix_acl *acl, int type)
 {
 	int ret;
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	struct inode *inode = d_inode(dentry);
 	umode_t old_mode = inode->i_mode;
 
 	if (type == ACL_TYPE_ACCESS && acl) {
-		ret = posix_acl_update_mode(mnt_userns, inode,
+		ret = posix_acl_update_mode(idmap, inode,
 					    &inode->i_mode, &acl);
 		if (ret)
 			return ret;
diff --git a/fs/ceph/acl.c b/fs/ceph/acl.c
index 59a05fd259f0..6945a938d396 100644
--- a/fs/ceph/acl.c
+++ b/fs/ceph/acl.c
@@ -105,7 +105,7 @@ int ceph_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 	case ACL_TYPE_ACCESS:
 		name = XATTR_NAME_POSIX_ACL_ACCESS;
 		if (acl) {
-			ret = posix_acl_update_mode(&init_user_ns, inode,
+			ret = posix_acl_update_mode(&nop_mnt_idmap, inode,
 						    &new_mode, &acl);
 			if (ret)
 				goto out;
diff --git a/fs/ext2/acl.c b/fs/ext2/acl.c
index f20953c7ec65..82b17d7fc93f 100644
--- a/fs/ext2/acl.c
+++ b/fs/ext2/acl.c
@@ -228,7 +228,7 @@ ext2_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 	umode_t mode = inode->i_mode;
 
 	if (type == ACL_TYPE_ACCESS && acl) {
-		error = posix_acl_update_mode(&init_user_ns, inode, &mode,
+		error = posix_acl_update_mode(&nop_mnt_idmap, inode, &mode,
 					      &acl);
 		if (error)
 			return error;
diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c
index 05139feb7282..27fcbddfb148 100644
--- a/fs/ext4/acl.c
+++ b/fs/ext4/acl.c
@@ -228,7 +228,6 @@ int
 ext4_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 	     struct posix_acl *acl, int type)
 {
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	handle_t *handle;
 	int error, credits, retries = 0;
 	size_t acl_size = acl ? ext4_acl_size(acl->a_count) : 0;
@@ -250,7 +249,7 @@ retry:
 		return PTR_ERR(handle);
 
 	if ((type == ACL_TYPE_ACCESS) && acl) {
-		error = posix_acl_update_mode(mnt_userns, inode, &mode, &acl);
+		error = posix_acl_update_mode(idmap, inode, &mode, &acl);
 		if (error)
 			goto out_stop;
 		if (mode != inode->i_mode)
diff --git a/fs/gfs2/acl.c b/fs/gfs2/acl.c
index e2a79d7e5605..a392aa0f041d 100644
--- a/fs/gfs2/acl.c
+++ b/fs/gfs2/acl.c
@@ -135,7 +135,7 @@ int gfs2_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 
 	mode = inode->i_mode;
 	if (type == ACL_TYPE_ACCESS && acl) {
-		ret = posix_acl_update_mode(&init_user_ns, inode, &mode, &acl);
+		ret = posix_acl_update_mode(&nop_mnt_idmap, inode, &mode, &acl);
 		if (ret)
 			goto unlock;
 	}
diff --git a/fs/jffs2/acl.c b/fs/jffs2/acl.c
index 672eaf51a66d..888a7ceb6479 100644
--- a/fs/jffs2/acl.c
+++ b/fs/jffs2/acl.c
@@ -241,7 +241,7 @@ int jffs2_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		if (acl) {
 			umode_t mode;
 
-			rc = posix_acl_update_mode(&init_user_ns, inode, &mode,
+			rc = posix_acl_update_mode(&nop_mnt_idmap, inode, &mode,
 						   &acl);
 			if (rc)
 				return rc;
diff --git a/fs/jfs/acl.c b/fs/jfs/acl.c
index 25b78dd82099..fb96f872d207 100644
--- a/fs/jfs/acl.c
+++ b/fs/jfs/acl.c
@@ -106,7 +106,7 @@ int jfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 	tid = txBegin(inode->i_sb, 0);
 	mutex_lock(&JFS_IP(inode)->commit_mutex);
 	if (type == ACL_TYPE_ACCESS && acl) {
-		rc = posix_acl_update_mode(&init_user_ns, inode, &mode, &acl);
+		rc = posix_acl_update_mode(&nop_mnt_idmap, inode, &mode, &acl);
 		if (rc)
 			goto end_tx;
 		if (mode != inode->i_mode)
diff --git a/fs/namei.c b/fs/namei.c
index a88017266ee5..637f8bee7132 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -273,7 +273,7 @@ void putname(struct filename *name)
 
 /**
  * check_acl - perform ACL permission checking
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @inode:	inode to check permissions on
  * @mask:	right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC ...)
  *
@@ -281,13 +281,13 @@ void putname(struct filename *name)
  * retrieve POSIX acls it needs to know whether it is called from a blocking or
  * non-blocking context and thus cares about the MAY_NOT_BLOCK bit.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then take
- * care to map the inode according to @mnt_userns before checking permissions.
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then take
+ * care to map the inode according to @idmap before checking permissions.
  * On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs init_user_ns.
+ * raw inode simply passs @nop_mnt_idmap.
  */
-static int check_acl(struct user_namespace *mnt_userns,
+static int check_acl(struct mnt_idmap *idmap,
 		     struct inode *inode, int mask)
 {
 #ifdef CONFIG_FS_POSIX_ACL
@@ -300,14 +300,14 @@ static int check_acl(struct user_namespace *mnt_userns,
 		/* no ->get_inode_acl() calls in RCU mode... */
 		if (is_uncached_acl(acl))
 			return -ECHILD;
-	        return posix_acl_permission(mnt_userns, inode, acl, mask);
+	        return posix_acl_permission(idmap, inode, acl, mask);
 	}
 
 	acl = get_inode_acl(inode, ACL_TYPE_ACCESS);
 	if (IS_ERR(acl))
 		return PTR_ERR(acl);
 	if (acl) {
-	        int error = posix_acl_permission(mnt_userns, inode, acl, mask);
+	        int error = posix_acl_permission(idmap, inode, acl, mask);
 	        posix_acl_release(acl);
 	        return error;
 	}
@@ -318,7 +318,7 @@ static int check_acl(struct user_namespace *mnt_userns,
 
 /**
  * acl_permission_check - perform basic UNIX permission checking
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:	idmap of the mount the inode was found from
  * @inode:	inode to check permissions on
  * @mask:	right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC ...)
  *
@@ -326,15 +326,16 @@ static int check_acl(struct user_namespace *mnt_userns,
  * function may retrieve POSIX acls it needs to know whether it is called from a
  * blocking or non-blocking context and thus cares about the MAY_NOT_BLOCK bit.
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then take
- * care to map the inode according to @mnt_userns before checking permissions.
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then take
+ * care to map the inode according to @idmap before checking permissions.
  * On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs init_user_ns.
+ * raw inode simply passs @nop_mnt_idmap.
  */
-static int acl_permission_check(struct user_namespace *mnt_userns,
+static int acl_permission_check(struct mnt_idmap *idmap,
 				struct inode *inode, int mask)
 {
+	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	unsigned int mode = inode->i_mode;
 	vfsuid_t vfsuid;
 
@@ -348,7 +349,7 @@ static int acl_permission_check(struct user_namespace *mnt_userns,
 
 	/* Do we have ACL's? */
 	if (IS_POSIXACL(inode) && (mode & S_IRWXG)) {
-		int error = check_acl(mnt_userns, inode, mask);
+		int error = check_acl(idmap, inode, mask);
 		if (error != -EAGAIN)
 			return error;
 	}
@@ -402,7 +403,7 @@ int generic_permission(struct mnt_idmap *idmap, struct inode *inode,
 	/*
 	 * Do the basic permission checks.
 	 */
-	ret = acl_permission_check(mnt_userns, inode, mask);
+	ret = acl_permission_check(idmap, inode, mask);
 	if (ret != -EACCES)
 		return ret;
 
diff --git a/fs/ntfs3/inode.c b/fs/ntfs3/inode.c
index 20b953871574..2a9347e747e5 100644
--- a/fs/ntfs3/inode.c
+++ b/fs/ntfs3/inode.c
@@ -1185,13 +1185,14 @@ out:
  * 
  * NOTE: if fnd != NULL (ntfs_atomic_open) then @dir is locked
  */
-struct inode *ntfs_create_inode(struct user_namespace *mnt_userns,
+struct inode *ntfs_create_inode(struct mnt_idmap *idmap,
 				struct inode *dir, struct dentry *dentry,
 				const struct cpu_str *uni, umode_t mode,
 				dev_t dev, const char *symname, u32 size,
 				struct ntfs_fnd *fnd)
 {
 	int err;
+	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	struct super_block *sb = dir->i_sb;
 	struct ntfs_sb_info *sbi = sb->s_fs_info;
 	const struct qstr *name = &dentry->d_name;
@@ -1614,7 +1615,7 @@ struct inode *ntfs_create_inode(struct user_namespace *mnt_userns,
 
 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
 	if (!S_ISLNK(mode) && (sb->s_flags & SB_POSIXACL)) {
-		err = ntfs_init_acl(mnt_userns, inode, dir);
+		err = ntfs_init_acl(idmap, inode, dir);
 		if (err)
 			goto out7;
 	} else
diff --git a/fs/ntfs3/namei.c b/fs/ntfs3/namei.c
index 13731de39010..407fe92394e2 100644
--- a/fs/ntfs3/namei.c
+++ b/fs/ntfs3/namei.c
@@ -97,10 +97,9 @@ static struct dentry *ntfs_lookup(struct inode *dir, struct dentry *dentry,
 static int ntfs_create(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode, bool excl)
 {
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	struct inode *inode;
 
-	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFREG | mode,
+	inode = ntfs_create_inode(idmap, dir, dentry, NULL, S_IFREG | mode,
 				  0, NULL, 0, NULL);
 
 	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
@@ -114,10 +113,9 @@ static int ntfs_create(struct mnt_idmap *idmap, struct inode *dir,
 static int ntfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode, dev_t rdev)
 {
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	struct inode *inode;
 
-	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, mode, rdev,
+	inode = ntfs_create_inode(idmap, dir, dentry, NULL, mode, rdev,
 				  NULL, 0, NULL);
 
 	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
@@ -188,11 +186,10 @@ static int ntfs_unlink(struct inode *dir, struct dentry *dentry)
 static int ntfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, const char *symname)
 {
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	u32 size = strlen(symname);
 	struct inode *inode;
 
-	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFLNK | 0777,
+	inode = ntfs_create_inode(idmap, dir, dentry, NULL, S_IFLNK | 0777,
 				  0, symname, size, NULL);
 
 	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
@@ -204,10 +201,9 @@ static int ntfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 static int ntfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode)
 {
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	struct inode *inode;
 
-	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFDIR | mode,
+	inode = ntfs_create_inode(idmap, dir, dentry, NULL, S_IFDIR | mode,
 				  0, NULL, 0, NULL);
 
 	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
@@ -419,13 +415,13 @@ static int ntfs_atomic_open(struct inode *dir, struct dentry *dentry,
 
 	/*
 	 * Unfortunately I don't know how to get here correct 'struct nameidata *nd'
-	 * or 'struct user_namespace *mnt_userns'.
+	 * or 'struct mnt_idmap *idmap'.
 	 * See atomic_open in fs/namei.c.
 	 * This is why xfstest/633 failed.
-	 * Looks like ntfs_atomic_open must accept 'struct user_namespace *mnt_userns' as argument.
+	 * Looks like ntfs_atomic_open must accept 'struct mnt_idmap *idmap' as argument.
 	 */
 
-	inode = ntfs_create_inode(&init_user_ns, dir, dentry, uni, mode, 0,
+	inode = ntfs_create_inode(&nop_mnt_idmap, dir, dentry, uni, mode, 0,
 				  NULL, 0, fnd);
 	err = IS_ERR(inode) ? PTR_ERR(inode)
 			    : finish_open(file, dentry, ntfs_file_open);
diff --git a/fs/ntfs3/ntfs_fs.h b/fs/ntfs3/ntfs_fs.h
index 9b649a5b6beb..80072e5f96f7 100644
--- a/fs/ntfs3/ntfs_fs.h
+++ b/fs/ntfs3/ntfs_fs.h
@@ -708,7 +708,7 @@ int ntfs_sync_inode(struct inode *inode);
 int ntfs_flush_inodes(struct super_block *sb, struct inode *i1,
 		      struct inode *i2);
 int inode_write_data(struct inode *inode, const void *data, size_t bytes);
-struct inode *ntfs_create_inode(struct user_namespace *mnt_userns,
+struct inode *ntfs_create_inode(struct mnt_idmap *idmap,
 				struct inode *dir, struct dentry *dentry,
 				const struct cpu_str *uni, umode_t mode,
 				dev_t dev, const char *symname, u32 size,
@@ -861,7 +861,7 @@ unsigned long ntfs_names_hash(const u16 *name, size_t len, const u16 *upcase,
 struct posix_acl *ntfs_get_acl(struct inode *inode, int type, bool rcu);
 int ntfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct posix_acl *acl, int type);
-int ntfs_init_acl(struct user_namespace *mnt_userns, struct inode *inode,
+int ntfs_init_acl(struct mnt_idmap *idmap, struct inode *inode,
 		  struct inode *dir);
 #else
 #define ntfs_get_acl NULL
diff --git a/fs/ntfs3/xattr.c b/fs/ntfs3/xattr.c
index 55ee27c96a4d..ff64302e87e5 100644
--- a/fs/ntfs3/xattr.c
+++ b/fs/ntfs3/xattr.c
@@ -578,7 +578,7 @@ struct posix_acl *ntfs_get_acl(struct inode *inode, int type, bool rcu)
 	return ntfs_get_acl_ex(inode, type, 0);
 }
 
-static noinline int ntfs_set_acl_ex(struct user_namespace *mnt_userns,
+static noinline int ntfs_set_acl_ex(struct mnt_idmap *idmap,
 				    struct inode *inode, struct posix_acl *acl,
 				    int type, bool init_acl)
 {
@@ -597,7 +597,7 @@ static noinline int ntfs_set_acl_ex(struct user_namespace *mnt_userns,
 	case ACL_TYPE_ACCESS:
 		/* Do not change i_mode if we are in init_acl */
 		if (acl && !init_acl) {
-			err = posix_acl_update_mode(mnt_userns, inode, &mode,
+			err = posix_acl_update_mode(idmap, inode, &mode,
 						    &acl);
 			if (err)
 				return err;
@@ -655,9 +655,7 @@ out:
 int ntfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct posix_acl *acl, int type)
 {
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
-
-	return ntfs_set_acl_ex(mnt_userns, d_inode(dentry), acl, type, false);
+	return ntfs_set_acl_ex(idmap, d_inode(dentry), acl, type, false);
 }
 
 /*
@@ -665,7 +663,7 @@ int ntfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
  *
  * Called from ntfs_create_inode().
  */
-int ntfs_init_acl(struct user_namespace *mnt_userns, struct inode *inode,
+int ntfs_init_acl(struct mnt_idmap *idmap, struct inode *inode,
 		  struct inode *dir)
 {
 	struct posix_acl *default_acl, *acl;
@@ -676,7 +674,7 @@ int ntfs_init_acl(struct user_namespace *mnt_userns, struct inode *inode,
 		return err;
 
 	if (default_acl) {
-		err = ntfs_set_acl_ex(mnt_userns, inode, default_acl,
+		err = ntfs_set_acl_ex(idmap, inode, default_acl,
 				      ACL_TYPE_DEFAULT, true);
 		posix_acl_release(default_acl);
 	} else {
@@ -685,7 +683,7 @@ int ntfs_init_acl(struct user_namespace *mnt_userns, struct inode *inode,
 
 	if (acl) {
 		if (!err)
-			err = ntfs_set_acl_ex(mnt_userns, inode, acl,
+			err = ntfs_set_acl_ex(idmap, inode, acl,
 					      ACL_TYPE_ACCESS, true);
 		posix_acl_release(acl);
 	} else {
diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c
index 9809756a0d51..9fd03eaf15f8 100644
--- a/fs/ocfs2/acl.c
+++ b/fs/ocfs2/acl.c
@@ -274,7 +274,7 @@ int ocfs2_iop_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 	if (type == ACL_TYPE_ACCESS && acl) {
 		umode_t mode;
 
-		status = posix_acl_update_mode(&init_user_ns, inode, &mode,
+		status = posix_acl_update_mode(&nop_mnt_idmap, inode, &mode,
 					       &acl);
 		if (status)
 			goto unlock;
diff --git a/fs/orangefs/acl.c b/fs/orangefs/acl.c
index 6a81336142c0..5aefb705bcc8 100644
--- a/fs/orangefs/acl.c
+++ b/fs/orangefs/acl.c
@@ -136,7 +136,7 @@ int orangefs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		 * and "mode" to the new desired value. It is up to
 		 * us to propagate the new mode back to the server...
 		 */
-		error = posix_acl_update_mode(&init_user_ns, inode,
+		error = posix_acl_update_mode(&nop_mnt_idmap, inode,
 					      &iattr.ia_mode, &acl);
 		if (error) {
 			gossip_err("%s: posix_acl_update_mode err: %d\n",
diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 1cd8c01508b8..b6c3b5b19435 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -372,11 +372,12 @@ EXPORT_SYMBOL(posix_acl_from_mode);
  * by the acl. Returns -E... otherwise.
  */
 int
-posix_acl_permission(struct user_namespace *mnt_userns, struct inode *inode,
+posix_acl_permission(struct mnt_idmap *idmap, struct inode *inode,
 		     const struct posix_acl *acl, int want)
 {
 	const struct posix_acl_entry *pa, *pe, *mask_obj;
 	struct user_namespace *fs_userns = i_user_ns(inode);
+	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	int found = 0;
 	vfsuid_t vfsuid;
 	vfsgid_t vfsgid;
@@ -683,7 +684,7 @@ EXPORT_SYMBOL_GPL(posix_acl_create);
 
 /**
  * posix_acl_update_mode  -  update mode in set_acl
- * @mnt_userns:	user namespace of the mount @inode was found from
+ * @idmap:	idmap of the mount @inode was found from
  * @inode:	target inode
  * @mode_p:	mode (pointer) for update
  * @acl:	acl pointer
@@ -695,18 +696,19 @@ EXPORT_SYMBOL_GPL(posix_acl_create);
  * As with chmod, clear the setgid bit if the caller is not in the owning group
  * or capable of CAP_FSETID (see inode_change_ok).
  *
- * If the inode has been found through an idmapped mount the user namespace of
- * the vfsmount must be passed through @mnt_userns. This function will then
- * take care to map the inode according to @mnt_userns before checking
+ * If the inode has been found through an idmapped mount the idmap of
+ * the vfsmount must be passed through @idmap. This function will then
+ * take care to map the inode according to @idmap before checking
  * permissions. On non-idmapped mounts or if permission checking is to be
- * performed on the raw inode simply passs init_user_ns.
+ * performed on the raw inode simply passs @nop_mnt_idmap.
  *
  * Called from set_acl inode operations.
  */
-int posix_acl_update_mode(struct user_namespace *mnt_userns,
+int posix_acl_update_mode(struct mnt_idmap *idmap,
 			  struct inode *inode, umode_t *mode_p,
 			  struct posix_acl **acl)
 {
+	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	umode_t mode = inode->i_mode;
 	int error;
 
@@ -982,11 +984,10 @@ int simple_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		   struct posix_acl *acl, int type)
 {
 	int error;
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	struct inode *inode = d_inode(dentry);
 
 	if (type == ACL_TYPE_ACCESS) {
-		error = posix_acl_update_mode(mnt_userns, inode,
+		error = posix_acl_update_mode(idmap, inode,
 				&inode->i_mode, &acl);
 		if (error)
 			return error;
@@ -1018,10 +1019,12 @@ int simple_acl_create(struct inode *dir, struct inode *inode)
 	return 0;
 }
 
-static int vfs_set_acl_idmapped_mnt(struct user_namespace *mnt_userns,
+static int vfs_set_acl_idmapped_mnt(struct mnt_idmap *idmap,
 				    struct user_namespace *fs_userns,
 				    struct posix_acl *acl)
 {
+	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
+
 	for (int n = 0; n < acl->a_count; n++) {
 		struct posix_acl_entry *acl_e = &acl->a_entries[n];
 
@@ -1057,7 +1060,6 @@ int vfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 {
 	int acl_type;
 	int error;
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	struct inode *inode = d_inode(dentry);
 	struct inode *delegated_inode = NULL;
 
@@ -1073,7 +1075,7 @@ int vfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		 * if this is a filesystem with a backing store - ultimately
 		 * translate them to backing store values.
 		 */
-		error = vfs_set_acl_idmapped_mnt(mnt_userns, i_user_ns(inode), kacl);
+		error = vfs_set_acl_idmapped_mnt(idmap, i_user_ns(inode), kacl);
 		if (error)
 			return error;
 	}
@@ -1089,7 +1091,7 @@ retry_deleg:
 	if (error)
 		goto out_inode_unlock;
 
-	error = security_inode_set_acl(mnt_userns, dentry, acl_name, kacl);
+	error = security_inode_set_acl(idmap, dentry, acl_name, kacl);
 	if (error)
 		goto out_inode_unlock;
 
@@ -1135,7 +1137,6 @@ EXPORT_SYMBOL_GPL(vfs_set_acl);
 struct posix_acl *vfs_get_acl(struct mnt_idmap *idmap,
 			      struct dentry *dentry, const char *acl_name)
 {
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	struct inode *inode = d_inode(dentry);
 	struct posix_acl *acl;
 	int acl_type, error;
@@ -1148,7 +1149,7 @@ struct posix_acl *vfs_get_acl(struct mnt_idmap *idmap,
 	 * The VFS has no restrictions on reading POSIX ACLs so calling
 	 * something like xattr_permission() isn't needed. Only LSMs get a say.
 	 */
-	error = security_inode_get_acl(mnt_userns, dentry, acl_name);
+	error = security_inode_get_acl(idmap, dentry, acl_name);
 	if (error)
 		return ERR_PTR(error);
 
@@ -1182,7 +1183,6 @@ int vfs_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 {
 	int acl_type;
 	int error;
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	struct inode *inode = d_inode(dentry);
 	struct inode *delegated_inode = NULL;
 
@@ -1201,7 +1201,7 @@ retry_deleg:
 	if (error)
 		goto out_inode_unlock;
 
-	error = security_inode_remove_acl(mnt_userns, dentry, acl_name);
+	error = security_inode_remove_acl(idmap, dentry, acl_name);
 	if (error)
 		goto out_inode_unlock;
 
@@ -1217,7 +1217,7 @@ retry_deleg:
 		error = -EOPNOTSUPP;
 	if (!error) {
 		fsnotify_xattr(dentry);
-		evm_inode_post_remove_acl(mnt_userns, dentry, acl_name);
+		evm_inode_post_remove_acl(idmap, dentry, acl_name);
 	}
 
 out_inode_unlock:
diff --git a/fs/reiserfs/xattr_acl.c b/fs/reiserfs/xattr_acl.c
index 186aeba6823c..138060452678 100644
--- a/fs/reiserfs/xattr_acl.c
+++ b/fs/reiserfs/xattr_acl.c
@@ -42,7 +42,7 @@ reiserfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 	reiserfs_write_unlock(inode->i_sb);
 	if (error == 0) {
 		if (type == ACL_TYPE_ACCESS && acl) {
-			error = posix_acl_update_mode(&init_user_ns, inode,
+			error = posix_acl_update_mode(&nop_mnt_idmap, inode,
 						      &mode, &acl);
 			if (error)
 				goto unlock;
diff --git a/fs/xfs/xfs_acl.c b/fs/xfs/xfs_acl.c
index a2d2c117a076..791db7d9c849 100644
--- a/fs/xfs/xfs_acl.c
+++ b/fs/xfs/xfs_acl.c
@@ -245,7 +245,6 @@ int
 xfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 	    struct posix_acl *acl, int type)
 {
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	umode_t mode;
 	bool set_mode = false;
 	int error = 0;
@@ -259,7 +258,7 @@ xfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		return error;
 
 	if (type == ACL_TYPE_ACCESS) {
-		error = posix_acl_update_mode(mnt_userns, inode, &mode, &acl);
+		error = posix_acl_update_mode(idmap, inode, &mode, &acl);
 		if (error)
 			return error;
 		set_mode = true;