xfs: fix quota accounting when a mount is idmapped

Nowadays, we indirectly use the idmap-aware helper functions in the VFS
to set the initial uid and gid of a file being created.  Unfortunately,
we didn't convert the quota code, which means we attach the wrong dquots
to files created on an idmapped mount.

Fixes: f736d93d ("xfs: support idmapped mounts")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

fs/xfs/xfs_inode.c

@@ -1007,7 +1007,8 @@ xfs_create(
 	/*
 	 * Make sure that we have allocated dquot(s) on disk.
 	 */
-	error = xfs_qm_vop_dqalloc(dp, current_fsuid(), current_fsgid(), prid,
+	error = xfs_qm_vop_dqalloc(dp, fsuid_into_mnt(mnt_userns),
+			fsgid_into_mnt(mnt_userns), prid,
 			XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
 			&udqp, &gdqp, &pdqp);
 	if (error)
@@ -1157,7 +1158,8 @@ xfs_create_tmpfile(
 	/*
 	 * Make sure that we have allocated dquot(s) on disk.
 	 */
-	error = xfs_qm_vop_dqalloc(dp, current_fsuid(), current_fsgid(), prid,
+	error = xfs_qm_vop_dqalloc(dp, fsuid_into_mnt(mnt_userns),
+			fsgid_into_mnt(mnt_userns), prid,
 			XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
 			&udqp, &gdqp, &pdqp);
 	if (error)

fs/xfs/xfs_symlink.c

@@ -182,7 +182,8 @@ xfs_symlink(
 	/*
 	 * Make sure that we have allocated dquot(s) on disk.
 	 */
-	error = xfs_qm_vop_dqalloc(dp, current_fsuid(), current_fsgid(), prid,
+	error = xfs_qm_vop_dqalloc(dp, fsuid_into_mnt(mnt_userns),
+			fsgid_into_mnt(mnt_userns), prid,
 			XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
 			&udqp, &gdqp, &pdqp);
 	if (error)