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>

5 files changed, 18 insertions, 14 deletions

diff --git a/fs/jfs/acl.c b/fs/jfs/acl.c
index cf79a34bfada..43c285c3d2a7 100644
--- a/fs/jfs/acl.c
+++ b/fs/jfs/acl.c
@@ -91,7 +91,8 @@ out:
 	return rc;
 }
 
-int jfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+int jfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
+		struct posix_acl *acl, int type)
 {
 	int rc;
 	tid_t tid;
diff --git a/fs/jfs/file.c b/fs/jfs/file.c
index 61c3b0c1fbf6..28b70e7c7dd4 100644
--- a/fs/jfs/file.c
+++ b/fs/jfs/file.c
@@ -85,7 +85,8 @@ static int jfs_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
-int jfs_setattr(struct dentry *dentry, struct iattr *iattr)
+int jfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+		struct iattr *iattr)
 {
 	struct inode *inode = d_inode(dentry);
 	int rc;
diff --git a/fs/jfs/jfs_acl.h b/fs/jfs/jfs_acl.h
index 9f8f92dd6f84..7ae389a7a366 100644
--- a/fs/jfs/jfs_acl.h
+++ b/fs/jfs/jfs_acl.h
@@ -8,7 +8,8 @@
 #ifdef CONFIG_JFS_POSIX_ACL
 
 struct posix_acl *jfs_get_acl(struct inode *inode, int type);
-int jfs_set_acl(struct inode *inode, struct posix_acl *acl, int type);
+int jfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
+		struct posix_acl *acl, int type);
 int jfs_init_acl(tid_t, struct inode *, struct inode *);
 
 #else
diff --git a/fs/jfs/jfs_inode.h b/fs/jfs/jfs_inode.h
index 70a0d12e427e..01daa0cb0ae5 100644
--- a/fs/jfs/jfs_inode.h
+++ b/fs/jfs/jfs_inode.h
@@ -26,7 +26,7 @@ extern struct dentry *jfs_fh_to_parent(struct super_block *sb, struct fid *fid,
 	int fh_len, int fh_type);
 extern void jfs_set_inode_flags(struct inode *);
 extern int jfs_get_block(struct inode *, sector_t, struct buffer_head *, int);
-extern int jfs_setattr(struct dentry *, struct iattr *);
+extern int jfs_setattr(struct user_namespace *, struct dentry *, struct iattr *);
 
 extern const struct address_space_operations jfs_aops;
 extern const struct inode_operations jfs_dir_inode_operations;
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index 7a55d14cc1af..9abed0d750e5 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -59,8 +59,8 @@ static inline void free_ea_wmap(struct inode *inode)
  * RETURN:	Errors from subroutines
  *
  */
-static int jfs_create(struct inode *dip, struct dentry *dentry, umode_t mode,
-		bool excl)
+static int jfs_create(struct user_namespace *mnt_userns, struct inode *dip,
+		      struct dentry *dentry, umode_t mode, bool excl)
 {
 	int rc = 0;
 	tid_t tid;		/* transaction id */
@@ -192,7 +192,8 @@ static int jfs_create(struct inode *dip, struct dentry *dentry, umode_t mode,
  * note:
  * EACCES: user needs search+write permission on the parent directory
  */
-static int jfs_mkdir(struct inode *dip, struct dentry *dentry, umode_t mode)
+static int jfs_mkdir(struct user_namespace *mnt_userns, struct inode *dip,
+		     struct dentry *dentry, umode_t mode)
 {
 	int rc = 0;
 	tid_t tid;		/* transaction id */
@@ -868,8 +869,8 @@ static int jfs_link(struct dentry *old_dentry,
  * an intermediate result whose length exceeds PATH_MAX [XPG4.2]
 */
 
-static int jfs_symlink(struct inode *dip, struct dentry *dentry,
-		const char *name)
+static int jfs_symlink(struct user_namespace *mnt_userns, struct inode *dip,
+		       struct dentry *dentry, const char *name)
 {
 	int rc;
 	tid_t tid;
@@ -1058,9 +1059,9 @@ static int jfs_symlink(struct inode *dip, struct dentry *dentry,
  *
  * FUNCTION:	rename a file or directory
  */
-static int jfs_rename(struct inode *old_dir, struct dentry *old_dentry,
-		      struct inode *new_dir, struct dentry *new_dentry,
-		      unsigned int flags)
+static int jfs_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 btstack btstack;
 	ino_t ino;
@@ -1344,8 +1345,8 @@ static int jfs_rename(struct inode *old_dir, struct dentry *old_dentry,
  *
  * FUNCTION:	Create a special file (device)
  */
-static int jfs_mknod(struct inode *dir, struct dentry *dentry,
-		umode_t mode, dev_t rdev)
+static int jfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+		     struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct jfs_inode_info *jfs_ip;
 	struct btstack btstack;