Re: [syzbot] [ext4?] WARNING in ext4_xattr_block_set (2)

[Theodore Ts'o]

#syz test git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 39f00f05f981..dab33412b858 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -6638,6 +6638,14 @@ static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
 	return 0;
 
 restore_opts:
+	if ((sb->s_flags & SB_RDONLY) &&
+	    !(old_sb_flags & SB_RDONLY)) {
+		ext4_warning(sb, "failing rw->ro transition");
+		if (sb_any_quota_suspended(sb)) {
+			ext4_warning(sb, "would resume quotas");
+//			dquot_resume(sb, -1);
+		}
+	}
 	sb->s_flags = old_sb_flags;
 	sbi->s_mount_opt = old_opts.s_mount_opt;
 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;