https://bugzilla.kernel.org/show_bug.cgi?id=200015 --- Comment #3 from Wen Xu (wen.xu@xxxxxxxxxx) --- (In reply to Theodore Tso from comment #2) > Thanks for the simplified POC. But unfortunately that doesn't really tell > me anything new. What I need is a simplified POC *image*. > > I can add a simplistic check to see if we get a negative group number in > ext4_discard_preallocations(), but that's not the real root cause. And it > wouldn't be a complete solution, since we would have add gazillions of > checks anywhere we use s_first_data_block. It's much better if we can > check s_first_data_block at mount time (which we do), and then make sure > that it can't get corrupted afterwards. > > So the real root cause is somehow, the superblock buffer has gotten > corrupted. We have a lot of checks to prevent this from happening --- > that's what the ext4_data_block_valid() function in fs/ext4/block_validity.c > is all about --- but obviously, we're missing a check somewhere. The > question is where. If we had a simplified POC image, I could look to find > the file system corruption that was causing the superblock to get trashed. > The problem is that there are so many random corruptions, many of them > completely irrelevant to the bug at hand, that this is extremely difficult. Yeah, I know. I will spend some time to make a simplified POC image for you :) -- You are receiving this mail because: You are watching the assignee of the bug.
