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
  ...

10 files changed, 39 insertions, 39 deletions

diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c
index 9f19cf9a5a9f..9fd03eaf15f8 100644
--- a/fs/ocfs2/acl.c
+++ b/fs/ocfs2/acl.c
@@ -260,7 +260,7 @@ static int ocfs2_set_acl(handle_t *handle,
 	return ret;
 }
 
-int ocfs2_iop_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ocfs2_iop_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		      struct posix_acl *acl, int type)
 {
 	struct buffer_head *bh = NULL;
@@ -274,7 +274,7 @@ int ocfs2_iop_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 	if (type == ACL_TYPE_ACCESS && acl) {
 		umode_t mode;
 
-		status = posix_acl_update_mode(&init_user_ns, inode, &mode,
+		status = posix_acl_update_mode(&nop_mnt_idmap, inode, &mode,
 					       &acl);
 		if (status)
 			goto unlock;
diff --git a/fs/ocfs2/acl.h b/fs/ocfs2/acl.h
index a897c4e41b26..667c6f03fa60 100644
--- a/fs/ocfs2/acl.h
+++ b/fs/ocfs2/acl.h
@@ -17,7 +17,7 @@ struct ocfs2_acl_entry {
 };
 
 struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type, bool rcu);
-int ocfs2_iop_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ocfs2_iop_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		      struct posix_acl *acl, int type);
 extern int ocfs2_acl_chmod(struct inode *, struct buffer_head *);
 extern int ocfs2_init_acl(handle_t *, struct inode *, struct inode *,
diff --git a/fs/ocfs2/dlmfs/dlmfs.c b/fs/ocfs2/dlmfs/dlmfs.c
index 8b2020f92b5f..ba26c5567cff 100644
--- a/fs/ocfs2/dlmfs/dlmfs.c
+++ b/fs/ocfs2/dlmfs/dlmfs.c
@@ -188,18 +188,18 @@ static int dlmfs_file_release(struct inode *inode,
  * We do ->setattr() just to override size changes.  Our size is the size
  * of the LVB and nothing else.
  */
-static int dlmfs_file_setattr(struct user_namespace *mnt_userns,
+static int dlmfs_file_setattr(struct mnt_idmap *idmap,
 			      struct dentry *dentry, struct iattr *attr)
 {
 	int error;
 	struct inode *inode = d_inode(dentry);
 
 	attr->ia_valid &= ~ATTR_SIZE;
-	error = setattr_prepare(&init_user_ns, dentry, attr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (error)
 		return error;
 
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 	mark_inode_dirty(inode);
 	return 0;
 }
@@ -336,7 +336,7 @@ static struct inode *dlmfs_get_root_inode(struct super_block *sb)
 
 	if (inode) {
 		inode->i_ino = get_next_ino();
-		inode_init_owner(&init_user_ns, inode, NULL, mode);
+		inode_init_owner(&nop_mnt_idmap, inode, NULL, mode);
 		inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
 		inc_nlink(inode);
 
@@ -359,7 +359,7 @@ static struct inode *dlmfs_get_inode(struct inode *parent,
 		return NULL;
 
 	inode->i_ino = get_next_ino();
-	inode_init_owner(&init_user_ns, inode, parent, mode);
+	inode_init_owner(&nop_mnt_idmap, inode, parent, mode);
 	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
 
 	ip = DLMFS_I(inode);
@@ -402,7 +402,7 @@ static struct inode *dlmfs_get_inode(struct inode *parent,
  * File creation. Allocate an inode, and we're done..
  */
 /* SMP-safe */
-static int dlmfs_mkdir(struct user_namespace * mnt_userns,
+static int dlmfs_mkdir(struct mnt_idmap * idmap,
 		       struct inode * dir,
 		       struct dentry * dentry,
 		       umode_t mode)
@@ -451,7 +451,7 @@ bail:
 	return status;
 }
 
-static int dlmfs_create(struct user_namespace *mnt_userns,
+static int dlmfs_create(struct mnt_idmap *idmap,
 			struct inode *dir,
 			struct dentry *dentry,
 			umode_t mode,
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 5c60b6bc85bf..efb09de4343d 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1111,7 +1111,7 @@ out:
 	return ret;
 }
 
-int ocfs2_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ocfs2_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct iattr *attr)
 {
 	int status = 0, size_change;
@@ -1142,11 +1142,11 @@ int ocfs2_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	if (!(attr->ia_valid & OCFS2_VALID_ATTRS))
 		return 0;
 
-	status = setattr_prepare(&init_user_ns, dentry, attr);
+	status = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (status)
 		return status;
 
-	if (is_quota_modification(mnt_userns, inode, attr)) {
+	if (is_quota_modification(&nop_mnt_idmap, inode, attr)) {
 		status = dquot_initialize(inode);
 		if (status)
 			return status;
@@ -1265,7 +1265,7 @@ int ocfs2_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		}
 	}
 
-	setattr_copy(&init_user_ns, inode, attr);
+	setattr_copy(&nop_mnt_idmap, inode, attr);
 	mark_inode_dirty(inode);
 
 	status = ocfs2_mark_inode_dirty(handle, inode, bh);
@@ -1302,7 +1302,7 @@ bail:
 	return status;
 }
 
-int ocfs2_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int ocfs2_getattr(struct mnt_idmap *idmap, const struct path *path,
 		  struct kstat *stat, u32 request_mask, unsigned int flags)
 {
 	struct inode *inode = d_inode(path->dentry);
@@ -1317,7 +1317,7 @@ int ocfs2_getattr(struct user_namespace *mnt_userns, const struct path *path,
 		goto bail;
 	}
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(&nop_mnt_idmap, inode, stat);
 	/*
 	 * If there is inline data in the inode, the inode will normally not
 	 * have data blocks allocated (it may have an external xattr block).
@@ -1334,7 +1334,7 @@ bail:
 	return err;
 }
 
-int ocfs2_permission(struct user_namespace *mnt_userns, struct inode *inode,
+int ocfs2_permission(struct mnt_idmap *idmap, struct inode *inode,
 		     int mask)
 {
 	int ret, had_lock;
@@ -1360,7 +1360,7 @@ int ocfs2_permission(struct user_namespace *mnt_userns, struct inode *inode,
 		dump_stack();
 	}
 
-	ret = generic_permission(&init_user_ns, inode, mask);
+	ret = generic_permission(&nop_mnt_idmap, inode, mask);
 
 	ocfs2_inode_unlock_tracker(inode, 0, &oh, had_lock);
 out:
@@ -1991,7 +1991,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
 		}
 	}
 
-	if (file && setattr_should_drop_suidgid(&init_user_ns, file_inode(file))) {
+	if (file && setattr_should_drop_suidgid(&nop_mnt_idmap, file_inode(file))) {
 		ret = __ocfs2_write_remove_suid(inode, di_bh);
 		if (ret) {
 			mlog_errno(ret);
@@ -2279,7 +2279,7 @@ static int ocfs2_prepare_inode_for_write(struct file *file,
 		 * inode. There's also the dinode i_size state which
 		 * can be lost via setattr during extending writes (we
 		 * set inode->i_size at the end of a write. */
-		if (setattr_should_drop_suidgid(&init_user_ns, inode)) {
+		if (setattr_should_drop_suidgid(&nop_mnt_idmap, inode)) {
 			if (meta_level == 0) {
 				ocfs2_inode_unlock_for_extent_tree(inode,
 								   &di_bh,
diff --git a/fs/ocfs2/file.h b/fs/ocfs2/file.h
index 71db8f3aa027..8e53e4ac1120 100644
--- a/fs/ocfs2/file.h
+++ b/fs/ocfs2/file.h
@@ -49,11 +49,11 @@ int ocfs2_extend_no_holes(struct inode *inode, struct buffer_head *di_bh,
 			  u64 new_i_size, u64 zero_to);
 int ocfs2_zero_extend(struct inode *inode, struct buffer_head *di_bh,
 		      loff_t zero_to);
-int ocfs2_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int ocfs2_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct iattr *attr);
-int ocfs2_getattr(struct user_namespace *mnt_userns, const struct path *path,
+int ocfs2_getattr(struct mnt_idmap *idmap, const struct path *path,
 		  struct kstat *stat, u32 request_mask, unsigned int flags);
-int ocfs2_permission(struct user_namespace *mnt_userns,
+int ocfs2_permission(struct mnt_idmap *idmap,
 		     struct inode *inode,
 		     int mask);
 
diff --git a/fs/ocfs2/ioctl.c b/fs/ocfs2/ioctl.c
index afd54ec66103..811a6ea374bb 100644
--- a/fs/ocfs2/ioctl.c
+++ b/fs/ocfs2/ioctl.c
@@ -82,7 +82,7 @@ int ocfs2_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 	return status;
 }
 
-int ocfs2_fileattr_set(struct user_namespace *mnt_userns,
+int ocfs2_fileattr_set(struct mnt_idmap *idmap,
 		       struct dentry *dentry, struct fileattr *fa)
 {
 	struct inode *inode = d_inode(dentry);
diff --git a/fs/ocfs2/ioctl.h b/fs/ocfs2/ioctl.h
index 0297c8846945..48a5fdfe87a1 100644
--- a/fs/ocfs2/ioctl.h
+++ b/fs/ocfs2/ioctl.h
@@ -12,7 +12,7 @@
 #define OCFS2_IOCTL_PROTO_H
 
 int ocfs2_fileattr_get(struct dentry *dentry, struct fileattr *fa);
-int ocfs2_fileattr_set(struct user_namespace *mnt_userns,
+int ocfs2_fileattr_set(struct mnt_idmap *idmap,
 		       struct dentry *dentry, struct fileattr *fa);
 long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
 long ocfs2_compat_ioctl(struct file *file, unsigned cmd, unsigned long arg);
diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index a8fd51afb794..9175dbc47201 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -197,8 +197,8 @@ static struct inode *ocfs2_get_init_inode(struct inode *dir, umode_t mode)
 	 * callers. */
 	if (S_ISDIR(mode))
 		set_nlink(inode, 2);
-	mode = mode_strip_sgid(&init_user_ns, dir, mode);
-	inode_init_owner(&init_user_ns, inode, dir, mode);
+	mode = mode_strip_sgid(&nop_mnt_idmap, dir, mode);
+	inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
 	status = dquot_initialize(inode);
 	if (status)
 		return ERR_PTR(status);
@@ -221,7 +221,7 @@ static void ocfs2_cleanup_add_entry_failure(struct ocfs2_super *osb,
 	iput(inode);
 }
 
-static int ocfs2_mknod(struct user_namespace *mnt_userns,
+static int ocfs2_mknod(struct mnt_idmap *idmap,
 		       struct inode *dir,
 		       struct dentry *dentry,
 		       umode_t mode,
@@ -642,7 +642,7 @@ static int ocfs2_mknod_locked(struct ocfs2_super *osb,
 				    fe_blkno, suballoc_loc, suballoc_bit);
 }
 
-static int ocfs2_mkdir(struct user_namespace *mnt_userns,
+static int ocfs2_mkdir(struct mnt_idmap *idmap,
 		       struct inode *dir,
 		       struct dentry *dentry,
 		       umode_t mode)
@@ -651,14 +651,14 @@ static int ocfs2_mkdir(struct user_namespace *mnt_userns,
 
 	trace_ocfs2_mkdir(dir, dentry, dentry->d_name.len, dentry->d_name.name,
 			  OCFS2_I(dir)->ip_blkno, mode);
-	ret = ocfs2_mknod(&init_user_ns, dir, dentry, mode | S_IFDIR, 0);
+	ret = ocfs2_mknod(&nop_mnt_idmap, dir, dentry, mode | S_IFDIR, 0);
 	if (ret)
 		mlog_errno(ret);
 
 	return ret;
 }
 
-static int ocfs2_create(struct user_namespace *mnt_userns,
+static int ocfs2_create(struct mnt_idmap *idmap,
 			struct inode *dir,
 			struct dentry *dentry,
 			umode_t mode,
@@ -668,7 +668,7 @@ static int ocfs2_create(struct user_namespace *mnt_userns,
 
 	trace_ocfs2_create(dir, dentry, dentry->d_name.len, dentry->d_name.name,
 			   (unsigned long long)OCFS2_I(dir)->ip_blkno, mode);
-	ret = ocfs2_mknod(&init_user_ns, dir, dentry, mode | S_IFREG, 0);
+	ret = ocfs2_mknod(&nop_mnt_idmap, dir, dentry, mode | S_IFREG, 0);
 	if (ret)
 		mlog_errno(ret);
 
@@ -1194,7 +1194,7 @@ static void ocfs2_double_unlock(struct inode *inode1, struct inode *inode2)
 		ocfs2_inode_unlock(inode2, 1);
 }
 
-static int ocfs2_rename(struct user_namespace *mnt_userns,
+static int ocfs2_rename(struct mnt_idmap *idmap,
 			struct inode *old_dir,
 			struct dentry *old_dentry,
 			struct inode *new_dir,
@@ -1784,7 +1784,7 @@ bail:
 	return status;
 }
 
-static int ocfs2_symlink(struct user_namespace *mnt_userns,
+static int ocfs2_symlink(struct mnt_idmap *idmap,
 			 struct inode *dir,
 			 struct dentry *dentry,
 			 const char *symname)
diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
index 623db358b1ef..5a656dc683f1 100644
--- a/fs/ocfs2/refcounttree.c
+++ b/fs/ocfs2/refcounttree.c
@@ -4316,7 +4316,7 @@ static inline int ocfs2_may_create(struct inode *dir, struct dentry *child)
 		return -EEXIST;
 	if (IS_DEADDIR(dir))
 		return -ENOENT;
-	return inode_permission(&init_user_ns, dir, MAY_WRITE | MAY_EXEC);
+	return inode_permission(&nop_mnt_idmap, dir, MAY_WRITE | MAY_EXEC);
 }
 
 /**
@@ -4370,7 +4370,7 @@ static int ocfs2_vfs_reflink(struct dentry *old_dentry, struct inode *dir,
 	 * file.
 	 */
 	if (!preserve) {
-		error = inode_permission(&init_user_ns, inode, MAY_READ);
+		error = inode_permission(&nop_mnt_idmap, inode, MAY_READ);
 		if (error)
 			return error;
 	}
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 95d0611c5fc7..389308efe854 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -7247,7 +7247,7 @@ static int ocfs2_xattr_security_get(const struct xattr_handler *handler,
 }
 
 static int ocfs2_xattr_security_set(const struct xattr_handler *handler,
-				    struct user_namespace *mnt_userns,
+				    struct mnt_idmap *idmap,
 				    struct dentry *unused, struct inode *inode,
 				    const char *name, const void *value,
 				    size_t size, int flags)
@@ -7320,7 +7320,7 @@ static int ocfs2_xattr_trusted_get(const struct xattr_handler *handler,
 }
 
 static int ocfs2_xattr_trusted_set(const struct xattr_handler *handler,
-				   struct user_namespace *mnt_userns,
+				   struct mnt_idmap *idmap,
 				   struct dentry *unused, struct inode *inode,
 				   const char *name, const void *value,
 				   size_t size, int flags)
@@ -7351,7 +7351,7 @@ static int ocfs2_xattr_user_get(const struct xattr_handler *handler,
 }
 
 static int ocfs2_xattr_user_set(const struct xattr_handler *handler,
-				struct user_namespace *mnt_userns,
+				struct mnt_idmap *idmap,
 				struct dentry *unused, struct inode *inode,
 				const char *name, const void *value,
 				size_t size, int flags)