From 549c7297717c32ee53f156cd949e055e601f67bb Mon Sep 17 00:00:00 2001
From: Christian Brauner <christian.brauner@ubuntu.com>
Date: Thu, 21 Jan 2021 14:19:43 +0100
Subject: [Backport 549c7297717c] 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>
---
 src/exfat_fs.h |  8 +++++---
 src/file.c     |  8 +++++---
 src/namei.c    | 14 ++++++++------
 3 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/src/exfat_fs.h b/src/exfat_fs.h
index b8f0e829ecbd26c14788899de066e533b6dbaf1e..d905bb9cd2ca61f9f25c0a338e441342af9778d8 100644
--- a/src/exfat_fs.h
+++ b/src/exfat_fs.h
@@ -416,9 +416,11 @@ int exfat_count_used_clusters(struct super_block *sb, unsigned int *ret_count);
 extern const struct file_operations exfat_file_operations;
 int __exfat_truncate(struct inode *inode, loff_t new_size);
 void exfat_truncate(struct inode *inode, loff_t size);
-int exfat_setattr(struct dentry *dentry, struct iattr *attr);
-int exfat_getattr(const struct path *path, struct kstat *stat,
-		unsigned int request_mask, unsigned int query_flags);
+int exfat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+		  struct iattr *attr);
+int exfat_getattr(struct user_namespace *mnt_userns, const struct path *path,
+		  struct kstat *stat, unsigned int request_mask,
+		  unsigned int query_flags);
 int exfat_file_fsync(struct file *file, loff_t start, loff_t end, int datasync);
 
 /* namei.c */
diff --git a/src/file.c b/src/file.c
index e9705b3295d31def9c56d86955da9ef359fd9567..3aa6eb4de5e3d40b7dd3693435ac5c4dbdda5aa3 100644
--- a/src/file.c
+++ b/src/file.c
@@ -267,8 +267,9 @@ void exfat_truncate(struct inode *inode, loff_t size)
 	mutex_unlock(&sbi->s_lock);
 }
 
-int exfat_getattr(const struct path *path, struct kstat *stat,
-		unsigned int request_mask, unsigned int query_flags)
+int exfat_getattr(struct user_namespace *mnt_uerns, const struct path *path,
+		  struct kstat *stat, unsigned int request_mask,
+		  unsigned int query_flags)
 {
 	struct inode *inode = d_backing_inode(path->dentry);
 	struct exfat_inode_info *ei = EXFAT_I(inode);
@@ -282,7 +283,8 @@ int exfat_getattr(const struct path *path, struct kstat *stat,
 	return 0;
 }
 
-int exfat_setattr(struct dentry *dentry, struct iattr *attr)
+int exfat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+		  struct iattr *attr)
 {
 	struct exfat_sb_info *sbi = EXFAT_SB(dentry->d_sb);
 	struct inode *inode = dentry->d_inode;
diff --git a/src/namei.c b/src/namei.c
index 2932b23a3b6c36ebfb82e5a5e7621c07fbb2822d..d9e8ec689c55ca3e8511177de0c01dfe1d3c090a 100644
--- a/src/namei.c
+++ b/src/namei.c
@@ -541,8 +541,8 @@ static int exfat_add_entry(struct inode *inode, const char *path,
 	return ret;
 }
 
-static int exfat_create(struct inode *dir, struct dentry *dentry, umode_t mode,
-		bool excl)
+static int exfat_create(struct user_namespace *mnt_userns, struct inode *dir,
+			struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct super_block *sb = dir->i_sb;
 	struct inode *inode;
@@ -827,7 +827,8 @@ static int exfat_unlink(struct inode *dir, struct dentry *dentry)
 	return err;
 }
 
-static int exfat_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+static int exfat_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+		       struct dentry *dentry, umode_t mode)
 {
 	struct super_block *sb = dir->i_sb;
 	struct inode *inode;
@@ -1318,9 +1319,10 @@ static int __exfat_rename(struct inode *old_parent_inode,
 	return ret;
 }
 
-static int exfat_rename(struct inode *old_dir, struct dentry *old_dentry,
-		struct inode *new_dir, struct dentry *new_dentry,
-		unsigned int flags)
+static int exfat_rename(struct user_namespace *mnt_userns,
+			struct inode *old_dir, struct dentry *old_dentry,
+			struct inode *new_dir, struct dentry *new_dentry,
+			unsigned int flags)
 {
 	struct inode *old_inode, *new_inode;
 	struct super_block *sb = old_dir->i_sb;
-- 
2.31.1