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, 24 insertions, 17 deletions

diff --git a/fs/f2fs/acl.c b/fs/f2fs/acl.c
index 6a95bf28f602..a19e86c9adac 100644
--- a/fs/f2fs/acl.c
+++ b/fs/f2fs/acl.c
@@ -249,7 +249,8 @@ static int __f2fs_set_acl(struct inode *inode, int type,
 	return error;
 }
 
-int f2fs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+int f2fs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
+		 struct posix_acl *acl, int type)
 {
 	if (unlikely(f2fs_cp_error(F2FS_I_SB(inode))))
 		return -EIO;
diff --git a/fs/f2fs/acl.h b/fs/f2fs/acl.h
index 124868c13f80..986fd1bc780b 100644
--- a/fs/f2fs/acl.h
+++ b/fs/f2fs/acl.h
@@ -34,7 +34,8 @@ struct f2fs_acl_header {
 #ifdef CONFIG_F2FS_FS_POSIX_ACL
 
 extern struct posix_acl *f2fs_get_acl(struct inode *, int);
-extern int f2fs_set_acl(struct inode *, struct posix_acl *, int);
+extern int f2fs_set_acl(struct user_namespace *, struct inode *,
+			struct posix_acl *, int);
 extern int f2fs_init_acl(struct inode *, struct inode *, struct page *,
 							struct page *);
 #else
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index bb11759191dc..c9002b1933f0 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -3135,9 +3135,10 @@ void f2fs_truncate_data_blocks(struct dnode_of_data *dn);
 int f2fs_do_truncate_blocks(struct inode *inode, u64 from, bool lock);
 int f2fs_truncate_blocks(struct inode *inode, u64 from, bool lock);
 int f2fs_truncate(struct inode *inode);
-int f2fs_getattr(const struct path *path, struct kstat *stat,
-			u32 request_mask, unsigned int flags);
-int f2fs_setattr(struct dentry *dentry, struct iattr *attr);
+int f2fs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+		 struct kstat *stat, u32 request_mask, unsigned int flags);
+int f2fs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+		 struct iattr *attr);
 int f2fs_truncate_hole(struct inode *inode, pgoff_t pg_start, pgoff_t pg_end);
 void f2fs_truncate_data_blocks_range(struct dnode_of_data *dn, int count);
 int f2fs_precache_extents(struct inode *inode);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 44cd0dbdbb5d..8f1e97e7d242 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -783,8 +783,8 @@ int f2fs_truncate(struct inode *inode)
 	return 0;
 }
 
-int f2fs_getattr(const struct path *path, struct kstat *stat,
-		 u32 request_mask, unsigned int query_flags)
+int f2fs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+		 struct kstat *stat, u32 request_mask, unsigned int query_flags)
 {
 	struct inode *inode = d_inode(path->dentry);
 	struct f2fs_inode_info *fi = F2FS_I(inode);
@@ -859,7 +859,8 @@ static void __setattr_copy(struct user_namespace *mnt_userns,
 #define __setattr_copy setattr_copy
 #endif
 
-int f2fs_setattr(struct dentry *dentry, struct iattr *attr)
+int f2fs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+		 struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
 	int err;
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index ad98926bacac..c061a67e43a3 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -314,8 +314,8 @@ static void set_compress_inode(struct f2fs_sb_info *sbi, struct inode *inode,
 	}
 }
 
-static int f2fs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
-						bool excl)
+static int f2fs_create(struct user_namespace *mnt_userns, struct inode *dir,
+		       struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	struct inode *inode;
@@ -637,8 +637,8 @@ static const char *f2fs_get_link(struct dentry *dentry,
 	return link;
 }
 
-static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
-					const char *symname)
+static int f2fs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+			struct dentry *dentry, const char *symname)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	struct inode *inode;
@@ -717,7 +717,8 @@ out_free_encrypted_link:
 	return err;
 }
 
-static int f2fs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+static int f2fs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+		      struct dentry *dentry, umode_t mode)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	struct inode *inode;
@@ -770,8 +771,8 @@ static int f2fs_rmdir(struct inode *dir, struct dentry *dentry)
 	return -ENOTEMPTY;
 }
 
-static int f2fs_mknod(struct inode *dir, struct dentry *dentry,
-				umode_t mode, dev_t rdev)
+static int f2fs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+		      struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	struct inode *inode;
@@ -874,7 +875,8 @@ out:
 	return err;
 }
 
-static int f2fs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
+static int f2fs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
+			struct dentry *dentry, umode_t mode)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 
@@ -1247,7 +1249,8 @@ out:
 	return err;
 }
 
-static int f2fs_rename2(struct inode *old_dir, struct dentry *old_dentry,
+static int f2fs_rename2(struct user_namespace *mnt_userns,
+			struct inode *old_dir, struct dentry *old_dentry,
 			struct inode *new_dir, struct dentry *new_dentry,
 			unsigned int flags)
 {