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, 27 insertions, 17 deletions

diff --git a/fs/jffs2/acl.c b/fs/jffs2/acl.c
index 5f27ac593479..55a79df70d24 100644
--- a/fs/jffs2/acl.c
+++ b/fs/jffs2/acl.c
@@ -226,7 +226,8 @@ static int __jffs2_set_acl(struct inode *inode, int xprefix, struct posix_acl *a
 	return rc;
 }
 
-int jffs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+int jffs2_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
+		  struct posix_acl *acl, int type)
 {
 	int rc, xprefix;
 
diff --git a/fs/jffs2/acl.h b/fs/jffs2/acl.h
index 12d0271bdde3..62c50da9d493 100644
--- a/fs/jffs2/acl.h
+++ b/fs/jffs2/acl.h
@@ -28,7 +28,8 @@ struct jffs2_acl_header {
 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 
 struct posix_acl *jffs2_get_acl(struct inode *inode, int type);
-int jffs2_set_acl(struct inode *inode, struct posix_acl *acl, int type);
+int jffs2_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
+		  struct posix_acl *acl, int type);
 extern int jffs2_init_acl_pre(struct inode *, struct inode *, umode_t *);
 extern int jffs2_init_acl_post(struct inode *);
 
diff --git a/fs/jffs2/dir.c b/fs/jffs2/dir.c
index 776493713153..c0aabbcbfd58 100644
--- a/fs/jffs2/dir.c
+++ b/fs/jffs2/dir.c
@@ -24,18 +24,21 @@
 
 static int jffs2_readdir (struct file *, struct dir_context *);
 
-static int jffs2_create (struct inode *,struct dentry *,umode_t,
-			 bool);
+static int jffs2_create (struct user_namespace *, struct inode *,
+		         struct dentry *, umode_t, bool);
 static struct dentry *jffs2_lookup (struct inode *,struct dentry *,
 				    unsigned int);
 static int jffs2_link (struct dentry *,struct inode *,struct dentry *);
 static int jffs2_unlink (struct inode *,struct dentry *);
-static int jffs2_symlink (struct inode *,struct dentry *,const char *);
-static int jffs2_mkdir (struct inode *,struct dentry *,umode_t);
+static int jffs2_symlink (struct user_namespace *, struct inode *,
+			  struct dentry *, const char *);
+static int jffs2_mkdir (struct user_namespace *, struct inode *,struct dentry *,
+			umode_t);
 static int jffs2_rmdir (struct inode *,struct dentry *);
-static int jffs2_mknod (struct inode *,struct dentry *,umode_t,dev_t);
-static int jffs2_rename (struct inode *, struct dentry *,
-			 struct inode *, struct dentry *,
+static int jffs2_mknod (struct user_namespace *, struct inode *,struct dentry *,
+			umode_t,dev_t);
+static int jffs2_rename (struct user_namespace *, struct inode *,
+			 struct dentry *, struct inode *, struct dentry *,
 			 unsigned int);
 
 const struct file_operations jffs2_dir_operations =
@@ -157,8 +160,8 @@ static int jffs2_readdir(struct file *file, struct dir_context *ctx)
 /***********************************************************************/
 
 
-static int jffs2_create(struct inode *dir_i, struct dentry *dentry,
-			umode_t mode, bool excl)
+static int jffs2_create(struct user_namespace *mnt_userns, struct inode *dir_i,
+			struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct jffs2_raw_inode *ri;
 	struct jffs2_inode_info *f, *dir_f;
@@ -276,7 +279,8 @@ static int jffs2_link (struct dentry *old_dentry, struct inode *dir_i, struct de
 
 /***********************************************************************/
 
-static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char *target)
+static int jffs2_symlink (struct user_namespace *mnt_userns, struct inode *dir_i,
+			  struct dentry *dentry, const char *target)
 {
 	struct jffs2_inode_info *f, *dir_f;
 	struct jffs2_sb_info *c;
@@ -438,7 +442,8 @@ static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char
 }
 
 
-static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, umode_t mode)
+static int jffs2_mkdir (struct user_namespace *mnt_userns, struct inode *dir_i,
+		        struct dentry *dentry, umode_t mode)
 {
 	struct jffs2_inode_info *f, *dir_f;
 	struct jffs2_sb_info *c;
@@ -609,7 +614,8 @@ static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
 	return ret;
 }
 
-static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, umode_t mode, dev_t rdev)
+static int jffs2_mknod (struct user_namespace *mnt_userns, struct inode *dir_i,
+		        struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct jffs2_inode_info *f, *dir_f;
 	struct jffs2_sb_info *c;
@@ -756,7 +762,8 @@ static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, umode_t mode
 	return ret;
 }
 
-static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,
+static int jffs2_rename (struct user_namespace *mnt_userns,
+			 struct inode *old_dir_i, struct dentry *old_dentry,
 			 struct inode *new_dir_i, struct dentry *new_dentry,
 			 unsigned int flags)
 {
diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c
index ee9f51bab4c6..2ac410477c4f 100644
--- a/fs/jffs2/fs.c
+++ b/fs/jffs2/fs.c
@@ -190,7 +190,8 @@ int jffs2_do_setattr (struct inode *inode, struct iattr *iattr)
 	return 0;
 }
 
-int jffs2_setattr(struct dentry *dentry, struct iattr *iattr)
+int jffs2_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+		  struct iattr *iattr)
 {
 	struct inode *inode = d_inode(dentry);
 	int rc;
diff --git a/fs/jffs2/os-linux.h b/fs/jffs2/os-linux.h
index ef1cfa61549e..173eccac691d 100644
--- a/fs/jffs2/os-linux.h
+++ b/fs/jffs2/os-linux.h
@@ -164,7 +164,7 @@ long jffs2_ioctl(struct file *, unsigned int, unsigned long);
 extern const struct inode_operations jffs2_symlink_inode_operations;
 
 /* fs.c */
-int jffs2_setattr (struct dentry *, struct iattr *);
+int jffs2_setattr (struct user_namespace *, struct dentry *, struct iattr *);
 int jffs2_do_setattr (struct inode *, struct iattr *);
 struct inode *jffs2_iget(struct super_block *, unsigned long);
 void jffs2_evict_inode (struct inode *);