Merge tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping

Pull vfs idmapping updates from Christian Brauner:

 - Last cycle we introduced the dedicated struct mnt_idmap type for
   mount idmapping and the required infrastucture in 256c8aed2b42 ("fs:
   introduce dedicated idmap type for mounts"). As promised in last
   cycle's pull request message this converts everything to rely on
   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 relevant on the mount level. Especially for
   non-vfs developers without detailed knowledge in this area this was a
   potential source for bugs.

   This finishes the conversion. Instead of passing the plain namespace
   around this updates all places that currently take a pointer to a
   mnt_userns with a pointer to struct mnt_idmap.

   Now that the conversion is done all helpers down to the really
   low-level helpers only accept a struct mnt_idmap argument instead of
   two namespace arguments.

   Conflating mount and other idmappings will now cause the compiler to
   complain loudly thus eliminating the possibility of any bugs. This
   makes it impossible for filesystem developers to mix up mount and
   filesystem idmappings as they are two distinct types and require
   distinct helpers that cannot be used interchangeably.

   Everything associated with struct mnt_idmap is moved into a single
   separate file. With that change no code can poke around in struct
   mnt_idmap. It can only be interacted with through dedicated helpers.
   That means all filesystems are and all of the vfs is completely
   oblivious to the actual implementation of idmappings.

   We are now also able to extend struct mnt_idmap as we see fit. For
   example, we can decouple it completely from namespaces for users that
   don't require or don't want to use them at all. We can also extend
   the concept of idmappings so we can cover filesystem specific
   requirements.

   In combination with the vfs{g,u}id_t work we finished in v6.2 this
   makes this feature substantially more robust and thus difficult to
   implement wrong by a given filesystem and also protects the vfs.

 - Enable idmapped mounts for tmpfs and fulfill a longstanding request.

   A long-standing request from users had been to make it possible to
   create idmapped mounts for tmpfs. For example, to share the host's
   tmpfs mount between multiple sandboxes. This is a prerequisite for
   some advanced Kubernetes cases. Systemd also has a range of use-cases
   to increase service isolation. And there are more users of this.

   However, with all of the other work going on this was way down on the
   priority list but luckily someone other than ourselves picked this
   up.

   As usual the patch is tiny as all the infrastructure work had been
   done multiple kernel releases ago. In addition to all the tests that
   we already have I requested that Rodrigo add a dedicated tmpfs
   testsuite for idmapped mounts to xfstests. It is to be included into
   xfstests during the v6.3 development cycle. This should add a slew of
   additional tests.

* tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping: (26 commits)
  shmem: support idmapped mounts for tmpfs
  fs: move mnt_idmap
  fs: port vfs{g,u}id helpers to mnt_idmap
  fs: port fs{g,u}id helpers to mnt_idmap
  fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap
  fs: port i_{g,u}id_{needs_}update() to mnt_idmap
  quota: port to mnt_idmap
  fs: port privilege checking helpers to mnt_idmap
  fs: port inode_owner_or_capable() to mnt_idmap
  fs: port inode_init_owner() to mnt_idmap
  fs: port acl to mnt_idmap
  fs: port xattr to mnt_idmap
  fs: port ->permission() to pass mnt_idmap
  fs: port ->fileattr_set() to pass mnt_idmap
  fs: port ->set_acl() to pass mnt_idmap
  fs: port ->get_acl() to pass mnt_idmap
  fs: port ->tmpfile() to pass mnt_idmap
  fs: port ->rename() to pass mnt_idmap
  fs: port ->mknod() to pass mnt_idmap
  fs: port ->mkdir() to pass mnt_idmap
  ...

5 files changed, 42 insertions, 40 deletions

diff --git a/fs/ntfs3/file.c b/fs/ntfs3/file.c
index d294cd975688..e9bdc1ff08c9 100644
--- a/fs/ntfs3/file.c
+++ b/fs/ntfs3/file.c
@@ -70,7 +70,7 @@ static long ntfs_compat_ioctl(struct file *filp, u32 cmd, unsigned long arg)
 /*
  * ntfs_getattr - inode_operations::getattr
  */
-int ntfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int ntfs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		 struct kstat *stat, u32 request_mask, u32 flags)
 {
 	struct inode *inode = d_inode(path->dentry);
@@ -84,7 +84,7 @@ int ntfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 
 	stat->attributes_mask |= STATX_ATTR_COMPRESSED | STATX_ATTR_ENCRYPTED;
 
-	generic_fillattr(mnt_userns, inode, stat);
+	generic_fillattr(idmap, inode, stat);
 
 	stat->result_mask |= STATX_BTIME;
 	stat->btime = ni->i_crtime;
@@ -657,7 +657,7 @@ out:
 /*
  * ntfs3_setattr - inode_operations::setattr
  */
-int ntfs3_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ntfs3_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct iattr *attr)
 {
 	struct super_block *sb = dentry->d_sb;
@@ -676,7 +676,7 @@ int ntfs3_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		ia_valid = attr->ia_valid;
 	}
 
-	err = setattr_prepare(mnt_userns, dentry, attr);
+	err = setattr_prepare(idmap, dentry, attr);
 	if (err)
 		goto out;
 
@@ -704,10 +704,10 @@ int ntfs3_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		inode->i_size = newsize;
 	}
 
-	setattr_copy(mnt_userns, inode, attr);
+	setattr_copy(idmap, inode, attr);
 
 	if (mode != inode->i_mode) {
-		err = ntfs_acl_chmod(mnt_userns, dentry);
+		err = ntfs_acl_chmod(idmap, dentry);
 		if (err)
 			goto out;
 
diff --git a/fs/ntfs3/inode.c b/fs/ntfs3/inode.c
index 20b953871574..8ce2616b087f 100644
--- a/fs/ntfs3/inode.c
+++ b/fs/ntfs3/inode.c
@@ -1185,7 +1185,7 @@ 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,
@@ -1307,7 +1307,7 @@ struct inode *ntfs_create_inode(struct user_namespace *mnt_userns,
 		goto out3;
 	}
 	inode = &ni->vfs_inode;
-	inode_init_owner(mnt_userns, inode, dir, mode);
+	inode_init_owner(idmap, inode, dir, mode);
 	mode = inode->i_mode;
 
 	inode->i_atime = inode->i_mtime = inode->i_ctime = ni->i_crtime =
@@ -1614,7 +1614,7 @@ 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 c8db35e2ae17..407fe92394e2 100644
--- a/fs/ntfs3/namei.c
+++ b/fs/ntfs3/namei.c
@@ -94,12 +94,12 @@ static struct dentry *ntfs_lookup(struct inode *dir, struct dentry *dentry,
 /*
  * ntfs_create - inode_operations::create
  */
-static int ntfs_create(struct user_namespace *mnt_userns, struct inode *dir,
+static int ntfs_create(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode, bool excl)
 {
 	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;
@@ -110,12 +110,12 @@ static int ntfs_create(struct user_namespace *mnt_userns, struct inode *dir,
  *
  * inode_operations::mknod
  */
-static int ntfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+static int ntfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	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;
@@ -183,13 +183,13 @@ static int ntfs_unlink(struct inode *dir, struct dentry *dentry)
 /*
  * ntfs_symlink - inode_operations::symlink
  */
-static int ntfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+static int ntfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, const char *symname)
 {
 	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;
@@ -198,12 +198,12 @@ static int ntfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
 /*
  * ntfs_mkdir- inode_operations::mkdir
  */
-static int ntfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+static int ntfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode)
 {
 	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;
@@ -229,7 +229,7 @@ static int ntfs_rmdir(struct inode *dir, struct dentry *dentry)
 /*
  * ntfs_rename - inode_operations::rename
  */
-static int ntfs_rename(struct user_namespace *mnt_userns, struct inode *dir,
+static int ntfs_rename(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, struct inode *new_dir,
 		       struct dentry *new_dentry, u32 flags)
 {
@@ -415,13 +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 0e051c5595a2..80072e5f96f7 100644
--- a/fs/ntfs3/ntfs_fs.h
+++ b/fs/ntfs3/ntfs_fs.h
@@ -492,10 +492,12 @@ bool dir_is_empty(struct inode *dir);
 extern const struct file_operations ntfs_dir_operations;
 
 /* Globals from file.c */
-int ntfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int ntfs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		 struct kstat *stat, u32 request_mask, u32 flags);
-int ntfs3_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ntfs3_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct iattr *attr);
+void ntfs_sparse_cluster(struct inode *inode, struct page *page0, CLST vcn,
+			 CLST len);
 int ntfs_file_open(struct inode *inode, struct file *file);
 int ntfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 		__u64 start, __u64 len);
@@ -706,7 +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,
@@ -857,17 +859,17 @@ unsigned long ntfs_names_hash(const u16 *name, size_t len, const u16 *upcase,
 /* globals from xattr.c */
 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
 struct posix_acl *ntfs_get_acl(struct inode *inode, int type, bool rcu);
-int ntfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+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
 #define ntfs_set_acl NULL
 #endif
 
-int ntfs_acl_chmod(struct user_namespace *mnt_userns, struct dentry *dentry);
-int ntfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
+int ntfs_acl_chmod(struct mnt_idmap *idmap, struct dentry *dentry);
+int ntfs_permission(struct mnt_idmap *idmap, struct inode *inode,
 		    int mask);
 ssize_t ntfs_listxattr(struct dentry *dentry, char *buffer, size_t size);
 extern const struct xattr_handler *ntfs_xattr_handlers[];
diff --git a/fs/ntfs3/xattr.c b/fs/ntfs3/xattr.c
index 616df209feea..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;
@@ -652,10 +652,10 @@ out:
 /*
  * ntfs_set_acl - inode_operations::set_acl
  */
-int ntfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ntfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct posix_acl *acl, int type)
 {
-	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);
 }
 
 /*
@@ -663,7 +663,7 @@ int ntfs_set_acl(struct user_namespace *mnt_userns, 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;
@@ -674,7 +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 {
@@ -683,7 +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 {
@@ -697,7 +697,7 @@ int ntfs_init_acl(struct user_namespace *mnt_userns, struct inode *inode,
 /*
  * ntfs_acl_chmod - Helper for ntfs3_setattr().
  */
-int ntfs_acl_chmod(struct user_namespace *mnt_userns, struct dentry *dentry)
+int ntfs_acl_chmod(struct mnt_idmap *idmap, struct dentry *dentry)
 {
 	struct inode *inode = d_inode(dentry);
 	struct super_block *sb = inode->i_sb;
@@ -708,13 +708,13 @@ int ntfs_acl_chmod(struct user_namespace *mnt_userns, struct dentry *dentry)
 	if (S_ISLNK(inode->i_mode))
 		return -EOPNOTSUPP;
 
-	return posix_acl_chmod(mnt_userns, dentry, inode->i_mode);
+	return posix_acl_chmod(idmap, dentry, inode->i_mode);
 }
 
 /*
  * ntfs_permission - inode_operations::permission
  */
-int ntfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
+int ntfs_permission(struct mnt_idmap *idmap, struct inode *inode,
 		    int mask)
 {
 	if (ntfs_sb(inode->i_sb)->options->noacsrules) {
@@ -722,7 +722,7 @@ int ntfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
 		return 0;
 	}
 
-	return generic_permission(mnt_userns, inode, mask);
+	return generic_permission(idmap, inode, mask);
 }
 
 /*
@@ -835,7 +835,7 @@ out:
  * ntfs_setxattr - inode_operations::setxattr
  */
 static noinline int ntfs_setxattr(const struct xattr_handler *handler,
-				  struct user_namespace *mnt_userns,
+				  struct mnt_idmap *idmap,
 				  struct dentry *de, struct inode *inode,
 				  const char *name, const void *value,
 				  size_t size, int flags)