quota: port to mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to 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 relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

9 files changed, 17 insertions, 18 deletions

diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index fb7fdadefd3d..26f135e7ffce 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -1621,7 +1621,6 @@ int ext2_getattr(struct mnt_idmap *idmap, const struct path *path,
 int ext2_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		 struct iattr *iattr)
 {
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	struct inode *inode = d_inode(dentry);
 	int error;
 
@@ -1629,14 +1628,14 @@ int ext2_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 	if (error)
 		return error;
 
-	if (is_quota_modification(mnt_userns, inode, iattr)) {
+	if (is_quota_modification(&nop_mnt_idmap, inode, iattr)) {
 		error = dquot_initialize(inode);
 		if (error)
 			return error;
 	}
-	if (i_uid_needs_update(mnt_userns, iattr, inode) ||
-	    i_gid_needs_update(mnt_userns, iattr, inode)) {
-		error = dquot_transfer(mnt_userns, inode, iattr);
+	if (i_uid_needs_update(&nop_mnt_idmap, iattr, inode) ||
+	    i_gid_needs_update(&nop_mnt_idmap, iattr, inode)) {
+		error = dquot_transfer(&nop_mnt_idmap, inode, iattr);
 		if (error)
 			return error;
 	}
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 3aae0be8c91e..8b9b1cb6e3ab 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5467,7 +5467,7 @@ int ext4_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 	if (error)
 		return error;
 
-	if (is_quota_modification(mnt_userns, inode, attr)) {
+	if (is_quota_modification(idmap, inode, attr)) {
 		error = dquot_initialize(inode);
 		if (error)
 			return error;
@@ -5491,7 +5491,7 @@ int ext4_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		 * counts xattr inode references.
 		 */
 		down_read(&EXT4_I(inode)->xattr_sem);
-		error = dquot_transfer(mnt_userns, inode, attr);
+		error = dquot_transfer(idmap, inode, attr);
 		up_read(&EXT4_I(inode)->xattr_sem);
 
 		if (error) {
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index b1486bdc83fb..262c831e3450 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -965,7 +965,7 @@ int f2fs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 	if (err)
 		return err;
 
-	if (is_quota_modification(mnt_userns, inode, attr)) {
+	if (is_quota_modification(idmap, inode, attr)) {
 		err = f2fs_dquot_initialize(inode);
 		if (err)
 			return err;
@@ -973,7 +973,7 @@ int f2fs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 	if (i_uid_needs_update(mnt_userns, attr, inode) ||
 	    i_gid_needs_update(mnt_userns, attr, inode)) {
 		f2fs_lock_op(F2FS_I_SB(inode));
-		err = dquot_transfer(mnt_userns, inode, attr);
+		err = dquot_transfer(idmap, inode, attr);
 		if (err) {
 			set_sbi_flag(F2FS_I_SB(inode),
 					SBI_QUOTA_NEED_REPAIR);
diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index 77fd453949b1..ac0149e0e98c 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -266,7 +266,7 @@ static int recover_quota_data(struct inode *inode, struct page *page)
 	if (!attr.ia_valid)
 		return 0;
 
-	err = dquot_transfer(&init_user_ns, inode, &attr);
+	err = dquot_transfer(&nop_mnt_idmap, inode, &attr);
 	if (err)
 		set_sbi_flag(F2FS_I_SB(inode), SBI_QUOTA_NEED_REPAIR);
 	return err;
diff --git a/fs/jfs/file.c b/fs/jfs/file.c
index c2cfb8033b1f..2ee35be49de1 100644
--- a/fs/jfs/file.c
+++ b/fs/jfs/file.c
@@ -95,14 +95,14 @@ int jfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 	if (rc)
 		return rc;
 
-	if (is_quota_modification(&init_user_ns, inode, iattr)) {
+	if (is_quota_modification(&nop_mnt_idmap, inode, iattr)) {
 		rc = dquot_initialize(inode);
 		if (rc)
 			return rc;
 	}
 	if ((iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)) ||
 	    (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))) {
-		rc = dquot_transfer(&init_user_ns, inode, iattr);
+		rc = dquot_transfer(&nop_mnt_idmap, inode, iattr);
 		if (rc)
 			return rc;
 	}
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 805a95e35f4c..efb09de4343d 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1114,7 +1114,6 @@ out:
 int ocfs2_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct iattr *attr)
 {
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	int status = 0, size_change;
 	int inode_locked = 0;
 	struct inode *inode = d_inode(dentry);
@@ -1147,7 +1146,7 @@ int ocfs2_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 	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;
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index f27faf5db554..6ae106c0f146 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -2085,9 +2085,10 @@ EXPORT_SYMBOL(__dquot_transfer);
 /* Wrapper for transferring ownership of an inode for uid/gid only
  * Called from FSXXX_setattr()
  */
-int dquot_transfer(struct user_namespace *mnt_userns, struct inode *inode,
+int dquot_transfer(struct mnt_idmap *idmap, struct inode *inode,
 		   struct iattr *iattr)
 {
+	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	struct dquot *transfer_to[MAXQUOTAS] = {};
 	struct dquot *dquot;
 	struct super_block *sb = inode->i_sb;
diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index 35b9b8ec1cbe..d54cab854f60 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -3276,7 +3276,7 @@ int reiserfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 	/* must be turned off for recursive notify_change calls */
 	ia_valid = attr->ia_valid &= ~(ATTR_KILL_SUID|ATTR_KILL_SGID);
 
-	if (is_quota_modification(&init_user_ns, inode, attr)) {
+	if (is_quota_modification(&nop_mnt_idmap, inode, attr)) {
 		error = dquot_initialize(inode);
 		if (error)
 			return error;
@@ -3359,7 +3359,7 @@ int reiserfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		reiserfs_write_unlock(inode->i_sb);
 		if (error)
 			goto out;
-		error = dquot_transfer(&init_user_ns, inode, attr);
+		error = dquot_transfer(&nop_mnt_idmap, inode, attr);
 		reiserfs_write_lock(inode->i_sb);
 		if (error) {
 			journal_end(&th);
diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
index 371964ed09dc..cb29234fab7e 100644
--- a/fs/zonefs/super.c
+++ b/fs/zonefs/super.c
@@ -626,7 +626,7 @@ static int zonefs_inode_setattr(struct mnt_idmap *idmap,
 	     !uid_eq(iattr->ia_uid, inode->i_uid)) ||
 	    ((iattr->ia_valid & ATTR_GID) &&
 	     !gid_eq(iattr->ia_gid, inode->i_gid))) {
-		ret = dquot_transfer(&init_user_ns, inode, iattr);
+		ret = dquot_transfer(&nop_mnt_idmap, inode, iattr);
 		if (ret)
 			return ret;
 	}